Glycosyltransferases (GTs) are enzymes that catalyze reactions attaching an activated sugar to an acceptor substrate, which may be a polysaccharide, peptide, lipid, or small molecule. In the past decade, notable progress has been made in revealing and cloning genes encoding polysaccharide-synthesizing GTs. However, the vast majority of GTs remain structurally and functionally uncharacterized. The mechanism by which they are organized in the Golgi membrane, where they synthesize complex, highly branched polysaccharide structures with high efficiency and fidelity, is also mostly unknown. This review will focus on current knowledge about plant polysaccharide-synthesizing GTs, specifically focusing on protein-protein interactions and the formation of multiprotein complexes. Plant polysaccharides that constitute plant cell wall extracellular structures in the form of lignocellulosic biomass are considered to be a source of renewable energy. Polysaccharides organized in highly cross-linked networks of cell walls contribute significantly to numerous physiologically important processes such as growth , stress The plant cell wall is a heterogeneous, highly diverse, and dynamic network predominantly made of different polysaccharides, a unique feature of plant cells. These polysaccharides are usually divided into three major groups: cellulose, hemicellulose, and pectin. While cellulose is a linear homopolymer composed of glucoses, hemicelluloses and pectic polysaccharides are highly branched heteropolysaccharides constructed from 15 different glycosides. The evolution of plants depended on the diversity that evolved in cell walls . Consequvia genetic and reverse-genetic studies , the enzymes involved in the synthesis of glycans or glycosylation, are distributed among 105 gene families annotated in the CAZy database . With re studies . HoweverAnother fundamental problem which limits our understanding of polysaccharide biosynthesis is the lack of knowledge about how GTs are organized and distributed in cell compartments. The synthesis of branched heterogeneous polysaccharides often requires the action of multiple, highly specific GTs which transfer various donor sugar substrates to oligosaccharide acceptors. It is well established that the Golgi is the organelle where most glycosylation processes take place and where the majority of GTs involved in protein and lipid post-synthetic glycosylation and complex polysaccharide synthesis are localized . Anothervia an alpha bond. When a GT catalyzes the formation of the glycosidic linkage, attaching the sugar to the acceptor molecule via alpha bond, the stereochemistry is retained. When the sugar is attached via a beta bond, the stereochemistry is inverted. It has been demonstrated and is well accepted that the catalytic mechanism of inverting GTs is a direct displacement SN2-like reaction. In this reaction, an active site residue acts as a general base to deprotonate the acceptor, which performs a nucleophilic attack on the donor anomeric carbon  and Förster resonance energy transfer to confirm protein-protein interactions between these proteins  9, IRX10, and IRX14A proteins form multiprotein complexes responsible for xylan backbone synthesis in the Golgi , which synthesizes the glucan backbone in xyloglucan, and six other proteins  involved in the synthesis of side chains in xyloglucan form homodimers and heterocomplexes . Furthermore, for XXT1–XXT1 and XXT2–XXT2 homodimers, all residues involved in ionic or hydrogen bonding between the two proteins were identical, and in XXT5–XXT5 only one pair of amino acids was different from the pair at the same position in the homodimers of XXT1 and XXT2. These observations suggest that the XXT proteins are interchangeable and can readily form homodimers or heterodimers via the same interaction surfaces. At this point, it is difficult to propose what implications such high fidelity of interacting residues in XXT proteins has on the stoichiometry of the whole xyloglucan-synthesizing complex in the Golgi and the biological relevance of the XXT1 homodimer, but there is likely certain flexibility in their compositional dynamics.Later, the crystal structure of XXT1 was solved by our group . The XXTt dimers . Studiesbidopsis  and a rethamiana . From thmodimers , 2015. Asis XXTs . There iGT sorting, concentration, and assembly into complexes in specific spatial locations necessarily depend on the nature of protein transport through the Golgi . Two maivia information encoded in the cytoplasmic tails of GTs  olis of GTs . On the s of GTs  and thats of GTs .The mechanisms of protein endomembrane trafficking in plants have been the subject of intensive studies in the last decade . CurrentIn this review, we have presented the current state of knowledge about plant polysaccharide-synthesizing GTs and the most recent findings on their organization in multiprotein complexes that are required to form the highly branched structures of heteropolysaccharides. There are still significant gaps in our understanding of the stoichiometry, structural organization, functioning, and substrate specificities of GT complexes involved in any type of glycosylation. Nevertheless, it is already evident that the formation and compositional dynamics of these large complexes is key to producing polysaccharide complexity and structural diversity. In addition to GTs, these complexes can also contain specific glycosidases, membrane-bound enzymes responsible for the interconversion of nucleotide sugars, and also multimembrane-spanning transporter proteins required to deliver nucleotide sugars from the cytoplasm (not described in this review). In addition, different acetyl- and methyltransferases can also be a part of the synthesizing complexes .in vivo, which will certainly advance investigations of GT complex compositional dynamics within different Golgi cisternae and their stability. Novel advances in protein crosslinking, in combination with highly sensitive mass spectrometry techniques (via weak interactions and investigate their composition and stoichiometry. Significant effort is still needed in the field of structural biology of polysaccharide-synthesizing GTs. Without knowledge of diverse GT 3D structures, it is difficult to envision significant progress in understanding the actual structural organization of these complexes, particularly when the complex carries multiple components. Structural studies of GTs using X-ray crystallography and NMR have become more feasible since an expression system using HEK293 cells was introduced for producing recombinant plant GTs (New developments in technology and methodologies enable advances in this exciting area of fundamental research. The demonstration of specific protein-protein interactions is an important first step in determining the potential complex formation, but it should always be followed by detailed studies of structural organization of the putative multiprotein complexes and their biological significance. Such detailed studies should include the determination of substrate specificities, the channeling of substrate to specific members of the complex, and the targeting of GTs to particular sub-Golgi compartments and consequently to specific polysaccharide-synthesizing complexes. In addition to the broadly used BiFC and FRET/fluorescence-lifetime imaging microscopy techniques, a recently developed approach in detecting protein-protein interactions using split-biotin assays  enables chniques , could alant GTs . The strlant GTs  and, undUltimately, the understanding of how GTs are organized to synthesize large complex polysaccharide structures will have a significant impact on many aspects of these enzymes’ utilization in plant biotechnology and material science. Thus, the understanding of what brings specific GTs together to synthesize particular structures and how GT activity, substrate specificity, and the structure of their products depend on GT organization in complexes will assist in engineering plant cell wall modifications to increase plant resilience to environmental cues and improving biomass properties for industrial applications. Furthermore, the understanding of GTs’ interdependence will contribute to their application in synthesizing new biomaterials, substituting or complementing chemical synthesis, which currently has significant limitations in synthesizing large, highly branched polysaccharide structures with high regiospecificity.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.OAZ wrote the review. NZ and RW contributed to writing and searching literature. WR prepared the figures. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The ecological functioning of dryland ecosystems is closely related to the spatial pattern of the vegetation, which is typically structured in patches. Ground arthropods mediate key soil functions and ecological processes, yet little is known about the influence of dryland vegetation pattern on their abundance and diversity. Here, we investigate how patch size and cover, and distance between patches relate to the abundance and diversity of meso-and microarthropods in semi-arid steppes. We found that species richness and abundance of ground arthropods exponentially increase with vegetation cover, patch size, and patch closeness. The communities under vegetation patches mainly respond to patch size, while the communities in the bare-soil interpatches are mostly controlled by the average distance between patches, independently of the concurrent changes in vegetation cover. Large patches seem to play a critical role as reserve and source of ground arthropod diversity. Our results suggest that decreasing vegetation cover and/or changes in vegetation pattern towards small and over-dispersed vegetation patches can fast lead to a significant loss of ground arthropods diversity in drylands. Drylands are arid, semiarid, and dry-subhumid ecosystems  that typWe define “ground arthropods” in a broad sense as all arthropods that spend their entire or partial lifetime in the litter or soil . This deExperimental studies demonstrated that changes in plant communities along successional dynamics relate to the diversity of ground-arthropod communities ,29, a reIn this paper, we investigate how variations in the spatial pattern of dryland vegetation affect the abundance, diversity, composition, and spatial distribution of ground meso-and microarthropods. Taking the semi-arid Mediterranean steppes of southern Spain as a dryland model, we aimed to determine how vegetation cover, patch size, and between-patch distance influence the abundance, richness, and high-level taxa composition of species of ground arthropods. The three landscape metrics selected for this study have proven to be critical control factors of dryland biotic structure and functioning. Thus, both vegetation cover and patch size largely explain soil and ecosystem multifunctionaliy ,41, and Stipa tenacissima L. A general overview of the vegetation and landscape is depicted in This study was carried out in Cabezo de la Plata, Murcia, Spain . The climate is semiarid , with a long dry period in summer. Soils are haplic calcisols and lithic leptosols . The are2. Within this area, we selected 14 (~400 m2) sampling plots distributed on steppe hillslopes. The plots largely varied in vegetation cover, from barely vegetated to almost fully covered plots, as result from previous grazing and human activities. On each sampling plot, we arbitrarily selected five vegetation patches (sampling patch). The patches were mainly consisted of S. tenacissima tussocks, often associated to few individuals of other grass and sub-shrub species. We also defined five bare-soil sampling points (sampling interpatch), each of them in the centroid of the positions of the nearest neighboring patches. Details of the sampling design on each plot are depicted in We reduced the geographic and seasonal influences on the species composition and abundance of ground fauna by minimizing the length of the sampling period to few months (July–August) and by limiting the study to an area of approximately 1 kmS(i)P, the size (diameter) of the individual sampling patch; (2) P-ND, the average distance between the sampling patch and the four nearest patch neighbors; and (3) I-ND, the average distance between the sampling interpatch and its four nearest patches. For the landscape-based approach, we estimated the average size (Ps) of the sampled patches in the plot, and the average patch closeness (Cl), calculated as the inverse of the plot average of all the P-ND values (cm−1).We characterized the spatial structure of the vegetation by measuring vegetation patch cover, patch size, and the distance between neighbor patches. Data of patch size and distance between patches were obtained from field measurements. On each sampling plot and for five sampling patches, we measured the patch diameter (cm) and the distance (cm) to each of the four nearest neighboring patches. From these measurements, we estimated three metrics at the sample-based scale: (1) CV) values for each plot from digital aerial images (Google EarthTM 2015). We identified and delimited the sampling plots on the aerial images and calculated their vegetation coverage using the ImageJ software [We calculated the vegetation cover  at each sampling point to collect all litter inside the quadrat and to take 1 L of soil (0–10 cm depth), from which the fauna was extracted. In the patch samples, a litter layer was always present, generating two distinct samples: the litter and the soil samples, which were separately collected and analyzed. For the interpatch samples, the litter layer was never present, and only the sample of the 0–10 cm soil layer was used. Each faunal sample (litter or soil) was individually bagged in the field and transported to the laboratory, being maintained in modified Berlese-Tülgren funnels for six days for faunal extraction. All collected arthropods were preserved in an ethanol solution (80%). As expected, this methodology predominantly sampled the meso-and microarthropods in comparison to macroarthropods, which were rarely collected. Next, we separated, counted and photographed the organisms using a stereo-microscope (Optech LFZ) coupled to a high-resolution digital camera (Nikon D3200) and a Leica microscope (ICC50).Arthropod identification was achieved at different taxonomic levels. However, given the difficulties to identify a number of species, we also used morphospecies sorting as a surrogate for the taxonomic sorting at the species level, which is considered to be a sufficiently reliable approach to assessing the ecology of soil communities ,51,52,53A) and number of species,  were calculated for single patch and interpatch samples and for pooled samples for each plot and microhabitat: interpatch, patch, patch litter and patch soil. For the sample-based analysis, we used the abundance and richness values for each individual patch and interpatch sample; for the landscape-based analyses, we used the pooled-sample data. The two analytical scales provide complementary information to elucidating how the resources provided by the vegetation patches and the relative isolation imposed by the bared soil areas jointly drive the abundance and diversity of dryland soil arthropods.Arthropod abundance  of the linear regressions between each covariable and the abundance and richness of soil arthropods. Given the expected correlation between the various vegetation pattern descriptors, we additionally used partial correlation analysis to test the independent effect of each vegetation descriptor on soil fauna once the influence of other vegetation pattern descriptors is excluded.Landscape-scale effect of vegetation pattern on soil arthropod abundance and richness was assessed using ANCOVAs, with either microsite type (patches vs. interpatches) or soil layer (litter vs. soil) as fixed factor and the vegetation pattern descriptor  as covariable. We also estimated the coefficient of determination  . To contI-ND) and the individual patch size S(i)P. We plotted individual interpatch and patch ground arthropod data against this new single variable, with the zero value on the x-axis figuratively representing the interface between interpatches and patches.For the sample-based analyses, we also used partial correlations to test the individual importance of each sample-level vegetation descriptor as explanatory variable for ground arthropod abundance and richness. Additionally, we graphically explored the spatial relationship between ground arthropod abundance and richness and the patch-interpatch landscape structure. To do so, we constructed a new variable composed by the average distance of the sampling interpatch to the nearest patches , mostly concentrated in patch samples, and consisting of 255 different morpho-species. The most important groups were Acari , Collembola , Psocodea , Coleoptera  and Araneae  scale, the abundance and species richness of ground arthropods, both in patches as in interpatches, were positively and exponentially related to vegetation cover, patch size and closeness . Both abil layer , as captPs or Cl .SP and CV were removed , Ps , and Cl , centipedes (Chilopoda), springtails (Collembola) and fly larvae (Diptera), showed higher abundance where patch size and vegetation cover were also higher. Other important groups for soil niches, such as Acari Oribatida and Prostigmata, related to plots with higher patch closeness. On the contrary, Diplopoda related to plots with low closeness. Some epigeic taxa, such as true bugs (Hemiptera), spiders (Araneae), barkflies (Psocoptera), and thrips (Thysanoptera) weakly related to plots with low vegetation cover, patch size, and closeness P), which was significantly correlated to both abundance and richness once the explanatory effect of distance (P-ND) and/or size (SN) of the neighboring patches were removed. Conversely, P-ND and SN did not show any significant correlation after controlling for the effect of S(i)P, yet P-ND showed significant correlations with arthropod abundance and richness when only the effect of SN was controlled  and species richness (S) found in interpatch points increased with decreasing distance to vegetation patches. For small distances, interpatch A and R were similar to the A and R values found for small vegetation patches , the sensitivity of ground arthropods to the environmental filter resulting from such conditions, and the protection and resources provided by plants  could joSeveral recent studies emphasized that local factors  could be more important than landscape-scale factors such as patch isolation ,63. Our The transitional zone between patch and interpatch (bare-soil) areas exhibited an important change in ground arthropod abundance and species richness, suggesting that edge effect ,65 couldWe found that the strong response of the patch ground arthropods to the variation in vegetation cover and pattern mostly relied on the arthropod communities living in the litter layer. In addition to the recognized decreasing pattern in the vertical distribution of resources  and niches throughout the litter-soil column ,70,71, mIt is well-known that changes in dryland vegetation cover and pattern are tightly linked to changes in ecosystem functions ,7,73. GiWe found a relatively high abundance and diversity of ground meso- and microarthropods in the studied Mediterranean dryland steppe, with high dominance of Acari groups. These findings agree with previous results from other dryland ecosystems, such as those reported for Australian semi-arid ecosystems , for a CVegetation cover, patch size, and between-patch distance exert a strong effect on the abundance and species richness of ground meso-and microarthropods in dryland steppes. On average, patch microhabitats sustain six times larger and four times richer communities of ground arthropods than interpatch microhabitats. Patch and interpatch communities also differ in their response to plant pattern, with patch communities being mostly controlled by patch size and interpatch communities mostly controlled by the average distance between patches. The combined influence of both microhabitats results in maximum abundance and diversity at the core of the vegetation patches that rapidly decrease around the patch-interpatch transition, and further decrease towards a minimum with increasing distance to the patches. The dependence of the ground communities on the vegetation pattern can be explained as a consequence of habitat and resource availability, reflected in the role played by vegetation cover and patch size, and the potential isolation of favorable microhabitats resulting from the spatial arrangement of vegetation patches and bare-soil areas. Our results suggest that scenarios in which vegetation patches are drastically reduced in size and proximity can lead to the loss of the habitat conditions necessary for sustaining diverse ground communities in drylands, with unknown consequences for soil functions; a topic that demands further research.


The link between asbestos exposure and the onset of thoracic malignancies is well established. However epidemiological studies have provided evidences that asbestos may be also involved in the development of gastrointestinal tumors, including intrahepatic cholangiocarcinoma (ICC). In line with this observation, asbestos fibers have been detected in the liver of patients with ICC. Although the exact mechanism still remains unknown, the presence of asbestos fibers in the liver could be explained in the light of their translocation pathway following ingestion/inhalation. In the liver, thin and long asbestos fibers could remain trapped in the smaller bile ducts, particularly in the stem cell niche of the canals of Hering, and exerting their carcinogenic effect for a long time, thus inducing hepatic stem/progenitor cells (HpSCs) malignant transformation. In this scenario, chronic liver damage induced by asbestos fibers over the years could be seen as a classic model of stem cell-derived carcinogenesis, where HpSC malignant transformation represents the first step of this process. This phenomenon could explain the recent epidemiological findings, where asbestos exposure seems mainly involved in ICC, rather than extrahepatic cholangiocarcinoma, development. Cholangiocarcinoma (CC) encompasses a heterogeneous group of malignancies developing from the biliary epithelial tree within (ICC) and outside (ECC) the liver . In the On this basis, the present review summarizes the current epidemiological knowledge about asbestos and ICC development. The carcinogenetic mechanisms of asbestos, along with the translocation pathway of fibers to the biliary tree and their potential target cells in the liver are also discussed.8O22 composition distinguished from one another by the number of the cations Ca, Fe, Mg and Na that they contain [The term asbestos is generically assigned to a group of naturally occurring fibrous silicates that have been largely employed in manufacturing and construction during the past century, due to their heat and chemical resistance, high mechanical and thermal stability and low cost. According to the chemical composition and crystalline structures, asbestos fibers can be divided into two groups: serpentines and amphiboles A. Chryso contain . Actinol contain ,7.The International Agency for Research on Cancer (IARC) classifies asbestos as a Group 1 human carcinogen . SeveralFiber dimension represents one of the main properties determining asbestos toxicity. Thin and long fibers may induce a state of chronic inflammation in target tissues, due to their ability to persist for a very long time in human body. Indeed as macrophages may reach 10–20 μm diameter, fibers longer 20 μm cannot be completely phagocytosed, thus leading to incomplete or ‘frustrated’ phagocytosis, characterized by the prolonged release of pro-inflammatory cytokines by activated macrophages . AsbestoAsbestos fibers may also absorb on their surface ionizing radiations and different types of carcinogens, leading to their accumulation in target cell ; in partAnother mechanisms linked to asbestos carcinogenesis is linked to the ability of fibers, especially chrysotile and crocidolite, to physically interact with chromosomes and mitotic spindle of dividing cells, resulting in multipolar mitosis and numerical  and structural  chromosomal alterations ,17,18. PAsbestos fibers may also target immunocompetent cells, leading to a decrease of tumor immunity by enhancement of regulatory T cell function, reduction of CXCR3 chemokine receptor expression in CD4+ T helper cells, and impairment of killing activities of CD8+ lymphocytes and NK cells .Host genetic background may play an important role in influencing cancer susceptibility in asbestos-exposed individuals. Germline mutations of the BRCA1 Associated Protein 1 (BAP1), the only gene that has been proposed to influence environmental carcinogenesis, have been indeed reported to increase cancer risk after minimal exposure to asbestos fibers in animal models . In partAlthough banned in 52 countries , environmental and occupational exposure to asbestos still represents a serious global health problem. Currently 125 million people worldwide are exposed to this compound , and eveAt present, the link between asbestos exposure and the development of MPM and lung cancer is well defined and widely accepted by the international community. Epidemiological evidences clearly suggest that asbestos fibers may be also implicated in the development of extra-pulmonary malignancies, especially of the gastrointestinal tract (GI), including ICC ,27,28,29Currently the amount of epidemiological studies on ICC incidence and asbestos exposure is limited. Despite this possible association has been suggested in some cohort studies , most ofRecently, two different case-control studies highlighted the role of asbestos in ICC development. The first study was based on historical data from 69 ICC and 86 ECC cases occurring at S. Orsola-Malpighi University Hospital of Bologna  between 2006 and 2010 . The casTo provide further evidence about an association between asbestos exposure and ICC development, we recently conducted a prospective case-control study  in collaboration with the Occupational medicine Unit of S. Orsola-Malpighi University Hospital of Bologna . The results obtained have been shown at the II biennal congress of the European Network for the Study of Cholangiocarcinoma (ENS-CCA) . A total of 168 CC cases (116 ICCs and 52 ECCs) and 185 controls  were recruited. Data on established or suspected CC risk factors were extracted from the clinical records of the cases and controls. Exposure to asbestos was based on categories derived from the ReNAM questionnaire categorization: unlikely (reference category), possible and likely. The results obtained in this study on incident cases not only confirm the results obtained in the two studies on prevalent cases ,29, but Basing on these findings, in order to identify putative molecular biomarkers of asbestos exposure in ICC patients, we performed next generation sequencing analysis in patients exposed and not-exposed to asbestos . Notably, patients exposed were found to display a distinctive molecular profile compared to the group of not exposed. These findings are in line with some studies in lung tumors showing a different molecular profile between asbestos-exposed and non-exposed patients, suggesting that asbestos could induce typical molecular alterations in target cells ,50,51.In continually renewing tissues, such as intestinal mucosa and epidermis, tissue homeostasis and regeneration after injury is sustained by the dynamic activity of resident stem cells, that are endowed with the ability of long-term self-renewal and multi-lineage differentiation . Stem ce0 quiescent state and enter the cell cycle and mitosis [In the liver, tissue homeostasis and regeneration after injury is more complex, due to the unique characteristics of this organ. Indeed, in normal conditions the liver is silent organ, with a very slow turnover of hepatocytes and cholangiocytes. However, after a mild/moderate injury, a regenerative response rapidly occurs, quickly restoring the pristine liver parenchyma . This ef mitosis .A different scenario occurs when the liver parenchyma is subjected to acute or chronic injury. In these circumstances, the regenerative capability of hepatocytes and cholangiocytes is lost or significantly impaired, due to necrosis/apoptosis or replicative senescence, this last resulting from the continuous turnover over 20–30 years of chronic liver disease, that gradually leads to telomere shortening in these cells ,56. NecrThe canals of Hering are adult remnants of the ductal plate of foetal and neonatal liver and are localized in the portal tract and periportal parenchyma. These canals, whose lumen is partially lined with hepatocytes and cholangiocytes, are the most peripheral branches of the biliary tree and represent the anatomical and physiologic link between hepatocyte canaliculi and biliary duct systems. The canals of Hering contain human hepatic stem/progenitor cells (HpSCs), bipotent progenitor cells capable to differentiate into mature hepatocytes and cholangiocytes . CommitmPBGs are tubulo-alveolar glands located in the deeper tissue of bile duct walls and communicating with the duct lumen. They are distributed along the biliary tree and supply the renewal of the epithelium of large intrahepatic bile ducts and extrahepatic biliary tree . PBGs coThe activation of resident stem/progenitor cell compartments within the liver and the biliary tree during chronic injury, along with the tight association between chronic liver damage and the development of primitive liver cancers, strongly supports the notion that primitive liver cancers arising from chronic injury may have a stem/progenitor cell origin. Due to the inherent capability of self-renewal and longevity, that allow sequential accumulation of genetic mutations over the years, stem cells represent indeed the ideal target for neoplastic transformation triggered by chronic injury. The putative stem/progenitor cell origin of some primitive liver cancers is also reinforced by the existence of poorly differentiated combined HCC-ICC, expressing a mixture of phenotypical traits belonging to hepatocytes, cholangiocytes and progenitor cells .The prerequisite for a role of asbestos in ICC carcinogenesis is the presence of fibers in the biliary tree within the liver. The first study reporting the detection of asbestos fibers in the biliary tract refers to a patient with asbestosis; post-mortem examination revealed a cancer arising from the cystic duct with short asbestos bodies and fragments with a similar shape of those observed in the lung . More reAlthough further studies on larger cohorts are needed to corroborate these preliminary results, overall these findings provide a proof of evidence that asbestos fibers can reach the biliary tract and the liver. Even if the exact mechanism still remains to be elucidated, the presence of these fibers in the biliary tree within the liver could be explained in the light of their translocation pathway . AsbestoThe concentration of asbestos fibers in target tissues depends on the number of fibers that are trapped and cannot be removed. As to the liver, the high microvascular permeability of the hepatic sinusoids may facilitate fiber deposition ; moreoveAlthough traditionally considered a rare tumor in Western countries, ICC incidence and mortality rate are rising worldwide and a further increment is expected in the near future, thus justifying the increasing scientific attention toward this malignancy. The most recent epidemiological studies have provided evidences about a link between asbestos exposure and ICC risk and may explain, at least in part, the global increase of this disease. Currently, the knowledge of the etiopathogenic and molecular mechanisms underlying ICC is rapidly evolving, also thanks to the availability of new and powerful analytical technologies with high throughput such as next-generation sequencing. The use of these methodologies has already made possible to identify a distinctive molecular signature in patients suffering from tumor diseases of environmental origin, and preliminary results confirm this finding also for ICC patients exposed to asbestos. As asbestos still represents a serious global health problem, the identification of molecular markers of exposure could not only improve the monitoring and the surveillance procedures for cohorts of subjects exposed and at high-risk of disease, but also allow the development of more personalized, stratified and efficacious strategies for the diagnosis, and perhaps treatment, of this dismal malignancy.


Biocidal active chemicals have potential health risks associated with exposure to retail biocide products such as disinfectants for COVID-19. Reliable exposure assessment was investigated to understand the exposure pattern of biocidal products used by occupational workers in their place of occupation, multi-use facilities, and general facilities. The interview–survey approach was taken to obtain the database about several subcategories of twelve occupational groups, the use pattern, and the exposure information of non-human hygiene disinfectant and insecticide products in workplaces. Furthermore, we investigated valuable exposure factors, e.g., the patterns of use, exposure routes, and quantifying potential hazardous chemical intake, on biocidal active ingredients. We focused on biocidal active-ingredient exposure from products used by twelve occupational worker groups. The 685 non-human hygiene disinfectants and 763 insecticides identified contained 152 and 97 different active-ingredient chemicals, respectively. The toxicity values and clinical health effects of total twelve ingredient chemicals were determined through a brief overview of toxicity studies aimed at estimating human health risks. To estimate actual exposure amounts divided by twelve occupational groups, the time spent to apply the products was investigated from the beginning to end of the product use. This study investigated the exposure assessment of occupational exposure to biocidal products used in workplaces, multi-use facilities, and general facilities. Furthermore, this study provides valuable information on occupational exposure that may be useful to conduct accurate exposure assessment and to manage products used for quarantine in general facilities. Retail biocidal products are commonly used in and around residential places (public consumer), workplaces , and multi-use facilities . Because of the recent coronavirus 2 (SARS-CoV-2) pandemic, various types of biocidal products including various biocidal active-ingredient chemicals are being used worldwide for surface disinfection (non-human hygiene disinfection) . For cleThe Korean government enacted “The Korean Biocidal Products Regulation (KBPR)”, which concerns the placing on the market and use of biocidal products, which are used to protect humans, materials, or articles against harmful organisms, by the action of the active chemicals contained in the biocidal product. According to this regulation, all biocidal products should undergo exposure and risk assessments to evaluate health and environmental hazards caused by their use. The exposure assessment component of a risk assessment of hazardous chemicals requires evaluation of exposure of relevant chemicals through all the relevant pathways by all the relevant routes of exposure for all relevant periods. The products of exposure assessment are estimates of exposure of defined subjects to each chemical by periods and exposure pathways ,12,13,14The consumers were categorized as general public consumers (household users) and occupational consumers. Occupational consumers were defined as consumers from occupational groups who use biocidal products in workplaces and public, multi-use facilities with high frequency because of their occupational characteristics. In order to characterize occupational consumers using biocidal product, the Korean Standard Classification of Occupation was referenced. Due to the characteristics of the occupation, the twelve occupational groups using a lot of biocidal products were selected. An interview–survey study was conducted to elucidate which biocidal products were commonly used in occupational places (workplaces) across all cities and provinces in Korea by occupational consumers. The interview–survey was carried out by a Korean survey company  that we hired. The survey company has participants from all provinces, cities in Korea. Participants were selected as follows: (1) workers having occupation belonging to the twelve occupational groups and (2) workers using biocidal products in their workplace because of occupational characteristics. Among the participants who agreed to take the interview–survey, those who had experience using target biocidal products were subsequently individually interviewed. On the basis of the interview results, the survey company conducted a market search to identify and characterize the retail biocidal products and ingredient chemicals that participants used.The interview–survey questionnaires consisted of information on biocidal products used in occupational places and the frequency of use, estimation of quantitative duration of exposure to products, quantitative amount of products used, and information on occupation . The actUse information of biocidal products in occupational places was investigated to obtain the frequency of using products, the exposed duration of products, and the exposed amount per application by considering target organisms and the purposes of use. In order to investigate the exposed amount of biocidal products for occupational consumers, we purchased the various surveyed products from the market. The survey questionnaire included the used amount per products’ application. On the basis of the survey results, the exposure amount of products was investigated for occupational consumers. Experiments were conducted to evaluate an accurate amount of product used per application. The amounts of products used (g/use) were measured by weighing used amounts; the weight of the product was measured before and after use. We followed procedures recommended by the National Institute for Public Health and the Environment (RIVM) in the Netherlands .In order to elucidate the manufactured and imported tonnage of biocidal chemicals per year in Korea, the retail product types including these chemicals, and the amount of chemicals used as active ingredients in retail products, the survey company conducted an extensive phone and online survey. A total of 459 manufacturing and importing companies took part in this survey study. The survey questionnaire asked participant companies to list the active biocidal chemicals, manufactured and imported tonnage per year, and the biocidal products they produced and imported. Additionally, the mixing ratio of biocidal chemicals in products as an active ingredient was obtained from the participant companies.The toxicological health effects and reference toxicity values  and no observed adverse effect levels (NOAELs)) of active-ingredient chemicals were investigated. An occupational consumer exposure assessment was carried out according to the guidance from the information requirement and chemical safety assessment, which was described as an efficient, step-wise, and iterative procedure . The target routes of exposure were considered to be inhalation and dermal route according to usage purpose and application types of products. An evaluation of the toxicological data was carried out in relation to the respiratory and irritant effects of long-term exposure to the ingredients under investigation , 2016). Official toxicology reports and studies  documents, United State California Environmental Protection Agent  documents, United State Registration Eligibility Decision (U.S. RED) report, and the European Union European Chemical Agency (EU ECHA) Dossier) were used for each chemical in order to investigate its toxicity value in the various products used. According to the toxicity value and health effects, dose rate, and toxicokinetic information should be considered. In particular, we derived reference toxicity values based on chronic NOAELs (no observed adverse effect levels). If the value of chronic NOAELs could not be derived, differences in toxicological values  and NOAELs) were taken into consideration.p value of less than 0.05 were considered to be statistically significant unless noted otherwise. As a statistical analysis method to verify the difference between groups, T-test or one-way ANOVA was carried out.All statistical analyses were conducted using SPSS version 22.0  differences with a For the purpose of exposure assessment, the different types of actual users need to be considered. As a first step, depending on the potential use of biocidal products, non-professional users (consumers) were categorized into public consumers (user in house) and occupational consumers  who are likely to be exposed directly to the retail biocidal products. This study focused on active-ingredient exposure from biocidal products used by occupational workers in their place of occupation, multi-use facilities, and general facilities. As a result of market searching, nine predominant usage purposes of non-human hygiene disinfectant and three categories of insecticide for common target insects  included for elimination or control were found in Korean retail markets. On the basis of the Korean Standard Classification of Occupation, we estimated that workers in the twelve occupational groups  could come into contact with biocidal products as a consequence of their occupational life .As a second step, the interview–survey approach obtained the database about several subcategories of the twelve occupational groups, biocidal product use pattern in occupational places, and exposure information of two biocidal product groups. A total of 2432 respondents, who had occupations belonging to the twelve occupational groups, completed the formal questionnaire during the interview–survey. Participants were continuously contacted for the interview survey until the required number of respondents (over 2000) was reached. On the basis of the survey results, it was determined that the survey respondents were using various biocidal products in occupational places and were regularly using them. The suboccupational distribution results of 2432 respondents  are summarized in The occupational use frequencies of biocidal products for total respondents were investigated. Survey responses were disaggregated based on occupational categories. Considering to the worst-case scenario about exposure amounts, we summed up the use amount of biocidal product groups divided by insecticide and non-human hygiene disinfectant per day and calculated the exposure amount of product groups according to use frequency and use amounts . The expThe search for biocidal products available in retail markets identified 685 non-human hygiene disinfectants and 763 insecticides that offered substantial diversity in product purpose and active-ingredient chemicals. In addition, we categorized a subset of searched products, dividing them by the purpose for non-human hygiene disinfectants and by the target insect intended for elimination or control for a more in-depth analysis. Based on the results of the interview–survey to the manufacturers and importers, 152 active-ingredient chemicals used in non-human hygiene disinfectants, 97 active-ingredient insecticides, and the mixing ratio of these chemicals in products were identified. The purpose for insecticides was often defined based on the specific target insect intended for elimination or control. Common target insects included mosquitoes, cockroaches, and houseflies. Furthermore, in order to estimate potential exposure by grasping the amount of active-ingredient chemicals distributed in South Korea, a total tonnage of manufactured and imported biocidal products per year in Korea was surveyed .The 685 non-human hygiene disinfectants and 763 insecticides identified in the product survey contained 152 and 97 different active-ingredient chemicals, including sodium hypochlorite, ethanol, hypochlorous acid, hydrogen peroxide, and didecyldimethylammonium chloride in disinfectants and tetramethrin, d-phenothrin, deltamethrin, and hydramethylnon in insecticides. Among the 685 disinfectants included in the subset, 108 products contained sodium hypochlorite and 83 products contained ethanol as the predominant active ingredient. Based on the results of the distributed number of retail products and total tonnage per year of manufactured and imported ingredients, several ingredient chemicals such as sodium hypochlorite, chlorine dioxide, and temephos were used in retail products in South Korean market. Among the surveyed active-ingredient chemicals, the levels of mixing ratio in products, the distribution of retail products including these ingredients, vapor pressure, and the structure for ten major ingredient chemicals are summarized in inhalation  of chlorine gas. Depending on chlorine concentrations, signs of toxicity ranged from dyspnea and coughing, irritation of the throat and eyes, headache, to temporary changes in lung function, cytopathological features, and tracheobronchial congestion. Exposure to 0.5 ppm (1.5 mg/m3) chlorine gas resulted in only trivial changes of lung-function parameters, therefore the NOAEC (no observed adverse effect concentration) was derived at 1.5 mg/m3.Toxicity values and clinical health effects of active-ingredient chemicals were determined through a brief overview of previous toxicity studies aimed at estimating human health risks, i.e., risks to product users and secondarily exposed by-standers . The toxThis study aimed to create a national exposure factor database for use in exposure and risk assessments of biocidal products in terms of human health. The study mainly showed that biocidal product use in prevalent occupational workplace, multi-use facilities, and general facilities could cause potential exposure of occupational consumers and the general public to their active-ingredient chemicals. Primary exposure to active-ingredient chemicals occurs to the consumer who actively uses the biocidal products. Secondary exposure is exposure that may occur after the actual use or application of the product. Primary exposures are invariably higher than secondary exposures . Among wIn order to estimate the health risk of active-ingredient chemicals to occupational consumers, the health risk study was carried out in steps: ① information on occupation characteristics using retail biocidal products and occupational consumers, ② retail product purchase and use: list of biocidal products used, ingredient chemicals, the mixing ratios in products, ③ toxicity identification and characterization of ingredient chemicals, ④ exposure assessment ; the frequency of use; qualitative descriptions of product use habits ,17,18,19The next step is health risk assessment, this assessment is ongoing as a further study. Fundamental to the health risk assessment process is the estimation of human exposure to the active-ingredient chemicals in retail biocidal products. The aim of the toxicity (hazard) identification is to identify the health effects of concern. Hazard characterization (dose–response assessment) is the estimation of the relationship between dose or level of exposure to ingredient chemical and the incidence and severity of an effect ,18. ThisThe specific pattern of use data requirements for different biocidal products are purpose of product , use environment , loading phase , application phase, post-application phase, and others. The essential information of use pattern requires the derivation of exposure scenarios, which are then evaluated to derive quantitative exposure estimates ,17. For This study investigated a fundamental approach to assess the occupational exposure to biocidal active ingredients by using products in occupational places (workplaces), multi-use facilities, and general facilities. The process of assessing exposure to biocidal products used in workplaces requires determining the patterns of use (exposure factors), identifying the exposure population , establishing exposure routes , and quantifying potential ingredient chemicals intake. This study determined the recent exposure factors using an interview survey of over 2400 occupational consumers using biocidal products in the occupational place, multi-use facilities, and general facilities. Estimating occupational exposure to biocidal active-ingredient chemicals via using products is a fundamental element of the health risk assessment process. Furthermore, we calculated the exposure amount of biocidal product used by occupational consumers. The exposure amount of products could be used for estimating the exposure amount to their ingredient chemicals of occupational consumers. Additionally, toxicological characteristics of ingredient chemicals were evaluated considering the characteristics of occupational characteristics and biocidal products categories. As a further study, the health risk assessment study of active ingredients to occupational consumers and public users of multi-use facilities and general facilities as a second exposure estimation were processed.


Implant-supported dentures are widely used in patients with defect or loss of dentition because these have higher chewing efficiency and do not damage the adjacent teeth compared with fixed or removable denture. An implant-supported denture carries the risk of failure in some systemic diseases, including osteoporosis, because of a non-ideal local microenvironment. Clinically common physical and chemical modifications are used to change the roughness of the implant surface to promote osseointegration, but they have limitations in promoting osteoinduction and inhibiting bone resorption. Recently, many researchers have focused on the study of bioactive modification of implants and have achieved promising results. Herein we have summarized the progress in bioactive modification strategy to promote osseointegration by regulating the local osteoporotic microenvironment. With innovations in implant design and surgery technology, the applicable conditions of implant surgery have become more extensive, and the 10-year survival rate of an implant-supported denture has exceeded 95% . There iCurrently, the common sand blasting and acid etching strategy is used to increase the surface roughness of implants, which enhances adhesion, proliferation, and differentiation of mesenchymal stem cells . In addiAnti-osteoporosis drugs are categorized according to their functions and effects and include anti-catabolic drugs, anabolic drugs, and dual-acting drugs . The comBeing an anabolic drug, the parathyroid hormone (PTH) activates the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) signaling pathway by acting on the PTH receptors in osteoblasts to promote osteointegration . PTH 1–3Strontium ranelate and simvastatin play dual effects of promoting bone formation and inhibiting bone absorption through various signaling pathways . Loadingin vitro, which effectively enhanced the osteogenic differentiation of stem cells. The release of BMP from the implant surface facilitated the proliferation, differentiation, and mineralization of bone cells in vitro and enhanced bone healing in vivo  coatings on the implant surface had both osteogenic and antibacterial effects , strontium (Sr), magnesium (Mg), zinc (Zn), and silicon (Si), can be also loaded on implants to stimulate osteogenesis , 2021. C effects . Zn-modi effects .There are many ways to build bioactive organic or inorganic coatings on the implant surface, including physical methods , chemical methods , and electrochemical strategies  . CovalenNano- and micro-topography construction on the implant surface not only can provide better biological responses but also may benefit drug adhesion and controlled release . The modBioactive agents can be attached to the implant surface by means of physical adsorption, such as dipping, spray coating, or drop casting, to promote local osseointegration . PhysicaBioactive agents can be encapsulated by biocompatible materials with appropriate biodegradability, including natural organic polymers [such as chitosan (CS) and gelatin], synthetic organic polymers [such as hyaluronic acid (HA) and polycaprolactone (PCL)], and inorganic materials . With continuous degradation of the encapsulation materials, the bioactive agents are gradually released into the target area to achieve sustained release . To locaHerein we have summarized the bioactive agents available to improve osseointegration in osteoporotic patients and the methods of controlled release of bioactive agents. High bioavailability and low toxicity in tissues outside the target make biomodification of implants suitable for achieving local osseointegration. Concerns about biosafety, however, limit the popularization of bioactive modification of implants, which is the direction of follow-up research. Implant osseointegration also must be accompanied by angiogenesis and ingrowth, and it is an inflammatory regulatory process, which is initially mediated by M1 phenotype macrophages and subsequently by M2. In addition, bacterial colonization and formation of plaque biofilms on the surface of implants may cause peri-implantitis, ultimately leading to failure of the implant. Therefore, angiogenesis and ingrowth, regulation of the inflammatory response, and inhibition of biofilm formation also should be considered in future studies.CZ and TZ wrote the original draft equally. TG helped to prepare the manuscript. XW gave conceptualization on this manuscript. KL and PW led the conceptualization and project administration, and supervised the writing and editing of the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Food ingestion induces homeostatic sensations  with a hedonic dimension  that characterize the postprandial experience. Both types of sensation are secondary to intraluminal stimuli produced by the food itself, as well as to the activity of the digestive tract. Postprandial sensations also depend on the nutrient composition of the meal and on colonic fermentation of non-absorbed residues. Gastrointestinal function and the sensitivity of the digestive tract, i.e., perception of gut stimuli, are determined by inherent individual factors, e.g., sex, and can be modulated by different conditioning mechanisms. This narrative review examines the factors that determine perception of digestive stimuli and the postprandial experience. Food ingestion activates the digestive system and induces conscious sensations. The digestive tract, in the first place, accommodates the ingested food, digests nutrients by mechanical and chemical actions, absorbs usable elements and disposes of non-absorbable residues. Conscious sensations related to ingestion involve the preingestive period, i.e., the eating experience, and postprandial sensations. This narrative review examines the factors that determine perception of digestive stimuli and the postprandial experience: (a) gut sensitivity; (b) digestive response; (c) composition of the meal, both absorbable nutrients and non-absorbable residues; (d) conditioning factors, e.g., hedonic , homeostatic (appetite) and cognitive/emotive ; and (e) constitutive individual factors, e.g., sex . Since fThe cephalic phase of digestion, involving both digestive function and sensation before and during the eating process , is reviHomeostatic sensations have a hedonic dimension revealed by their association with changes in digestive well-being and mood. Depending on the conditions, hedonic sensations may be positive or negative, so that the postprandial experience may have a pleasant/rewarding or an aversive dimension. The relation between homeostatic and hedonic sensations was investigated measuring sensory responses before, during, and after stepwise ingestion of a comfort meal up to full satiation. During stepwise ingestion, homeostatic sensations progressively increased up to full satiation and, hence, exhibit a direct relation to the meal load. Hedonic sensations initially increased up to a peak, and later decreased down to negative sensation of digestive well-being at the point of full satiation . These dHomeostatic and hedonic sensations decrease in intensity during the postprandial period: the consummatory reward fades and as satiety exhausts, while rising hunger sensation calls for the next meal. Experimental data suggest that different biological mechanism mediate homeostatic and hedonic components of the postprandial experience . For exaDigestive function determines how intraluminal stimuli are perceived, so that a satisfactory postprandial experience depends on adequate digestive responses to the meal ,9,10,11.During fasting, the stomach and small intestine exhibit cyclic activity: periods of quiescence alternate with short periods of intense activity featuring powerful gastrointestinal contractions and bouts of gastrointestinal and bilio-pancreatic secretion. This cyclic activity is independent of external stimuli and its proposed function is to clear secretions, cellular debris or remaining residues from the lumen.After ingestion, meal-related stimuli in the gastrointestinal tract activate specific receptors in the gut wall and release a complex series of reflexes that replace the stereotyped fasting activity pattern by a tightly regulated gastrointestinal motor and barrier function  to accomplish the digestive process, such that only non-absorbed residues reach the colon . During Intraluminal stimuli gradually fade as the digestive process  takes place, and this is associated with a decay of postprandial sensations. Hunger sensation after a meal has been related to the first period of activity of the fasting motor pattern after the end of the digestive process (hunger contractions) .Alteration of digestive function impairs the postprandial experience. For instance, experimental distortion of gastric accommodation produced by distension of the stomach with a balloon, was associated with fullness sensation and impaired hedonic responses to a probe meal . PatientMeal ingestion also induces somatic responses that may influence the postprandial experience. In normal conditions, the activity of the muscles of the abdomino-thoracic walls adapt to the volume of content. This phenomenon is known as abdominal accommodation ,24. MealIt has been shown that intraluminal stimuli in the gut activate sensory afferents and elicit conscious sensations. Conscious information from the gut is driven by sympathetic-spinal afferents ,31: PeriDifferent types of experimental stimuli, including mechanical, thermal, chemical and electrical, induce, in healthy subjects, sensations similar to the symptoms experienced by patients with functional gut disorders, such as abdominal fullness, bloating, cramps, stinging sensation and nausea . It has The intensity of conscious sensations is directly related to the magnitude of stimulation; low magnitude stimuli are barely perceived, and conscious perception progressively increases with stronger stimuli, until it becomes uncomfortable or painful. Perception of mechanical stimuli in the digestive tract depends on activation of tension receptors . DiffereAs described above, the meal contains components that are digested and absorbed in the small bowel and non-absorbable residues that pass into the colon and are fermented by the microbiota. Meal composition, specifically the type of absorbable components and the content of non-absorbable residues, influence the postprandial experience.A recent proof-of-concept study explored the role of meal composition on the postprandial experience, by comparing the effect of two types of meals with agreeable flavors: a homogeneous nutrient drink versus a heterogeneous solid-liquid meal  . DespiteThe effect of nutrient composition of the meal on postprandial sensations was further explored by comparing the responses to a high-fat versus a low-fat hummus; all other characteristics, presentation, palatability and volume, were identical. The high-fat meal induced more satiety/fullness but less satisfaction (less digestive well-being) than the low-fat meal . Hence, During the post-absorption phase of digestion meal components in the internal milieu may also influence the postprandial experience. Little is known about the specific influence of each of the absorbed components on the postprandial experience, and further research is needed. However; the metabolomic response to a comfort meal and the correlation between sensations and circulating metabolites was explored in 32 healthy men. The postprandial experience in this experimental paradigm was characterized by increased homeostatic sensations (satiety and fullness) with a positive hedonic component (well-being and mood) and a robust change in the metabolomic profile. Meal ingestion was associated with an increase in the levels of acetate, alanine, creatinine, formate, glucose and very low-density lipoproteins (VLDL), and a decrease in the levels of acetone, isoleucine, low-density lipoproteins (LDL) and high-density lipoproteins (HDL). The sensation of fullness after the meal correlated with the postprandial increase in glucose and alanine. Furthermore; the increase in glucose correlated with mood improvement and the increase in alanine correlated with postprandial satisfaction. Mood improvement was also positively correlated with medium size HDL particles and inversely correlated with large size HDL particles; large LDL particles exhibited an inverse correlation with digestive well-being .In contrast to the virtually empty stomach and small bowel during fasting, in normal conditions a biomass between 500–800 mL permanently sits in the lumen of the colon. With a 100–200 mL faecal output per day, the daily turnover of colonic biomass is about 30% . ColonicColonic biomass influences digestive sensations by two mechanisms: the volume of colonic content  and the influence of microbiota on gut function. The effect of non-absorbable residues in the diet on gut sensations was investigated by a series of different studies using a method to measure gut content based on abdominal magnetic resonance imaging ,57. UsinThe responses to meal ingestion and the way meal-related stimuli in the gut are perceived may be influenced by different conditioning factors related to the meal load (as discussed above), valence , homeostatic status of the individual (appetite) and cognitive/emotive mechanisms .Palatability of the meal is determined by the organoleptic characteristics of the meal (food flavor) and by the way the individual perceives it . Food flThe homeostatic status of the eater influences the responses to meal ingestion and the postprandial experience: internal signals influence perception arising from sensory receptors . In healIt is not known whether and to what extent the effect of cognitive/emotive conditioning on postprandial sensations is exerted via modulation of gut function or sensitivity. There is a close interaction between the brain and the gut. Gut stimuli activate receptors in the gut wall and induce conscious sensations. As discussed above, the sensory input is modulated at different levels between the gut wall and the brain and, specifically, the activity of the central nervous system modulates gut perception. On the other hand, under certain conditions emotive/cognitive factors may influence the activity of the digestive system ,75. PercA recent study showed that an educational intervention modified the postprandial experience. The study measured the responses to a probe meal on 2 separate days before and after a single sensory-cognitive educational intervention . In contrast to sham education, real education enhanced both homeostatic and hedonic responses to the probe meal . These dBeliefs and expectations play an important role in this context. Some patients complain (and believe) that eating lettuce, gives them gas and abdominal distention. Using computed tomography (CT) scans to measure the amount of intestinal gas and the morphometric configuration of the abdominal cavity, it was shown that during an episode of lettuce-induced distension patients exhibited a real increase in girth, but without a significant increase in the content of colonic gas. Abdominal distension was related to a descent of the diaphragm with redistribution of normal abdominal contents. Using a biofeedback technique , patientIn healthy subjects, neutral stimuli, may become aversive when paired with painful digestive sensations. This has been shown using painful rectal distension as the unconditioned stimulus and neutral visual stimuli (plain geometric figures) as the conditioned stimulus ,86,87. SThese data indicate that associative learning might be a significant factor determining the postprandial experience. This is particularly interesting, since fear of conditioning to innocuous gastrointestinal sensations may be an important mechanism in the pathogenesis of functional gut disorders. For example, in functional dyspepsia the information provided to patients regarding the fat content of a meal is associated with symptom production without direct correlation with the actual fat content ,90 Figu, and fauThe data described above show that conditioning influences the sensory response to a meal via inducible factors. However, inherent characteristics of the eater (constitutive factors) also play a role.A proof-of-concept study investigated the role of sex, as a constitutive factor, on the meal-related experience, comparing the sensations before, during, and after stepwise ingestion of a comfort meal up to full satiation. Satisfaction increased gradually up to a peak, and then decreased to a nadir at the point of full satiation. Compared to men, the meal load consumed at the well-being peak was lower and induced significantly less fullness in women. Consequently, men required larger amounts of food as well as stronger homeostatic sensations to achieve satisfaction. The same pattern was observed at the level of full satiation: men ate more and experienced positive well-being, while in women, well-being scores dropped below pre-meal level . The effA subsequent study compared the postprandial responses to a palatable comfort meal in women and men, measuring homeostatic sensations  and hedonic sensations , vagal tone (by heart rate variability) and the metabolomic profile before and after meal ingestion. Women exhibited a more intense sensory experience, in particular more postprandial fullness, than men, and their vagal tone response was also more pronounced . The stuMore intense fullness in women with the same meal load could be explained by a smaller gastric capacity; however, this possibility was ruled out by a study showing no differences in fasting gastric compliance (the pressure volume curve during inflation) between women and men . By contAnother study compared the impact of a well-liked meal on brain activity in women and men . In bothAs discussed above, perception of meal-related stimuli in the gut is influenced by conditioning factors. A study investigated the effect of the eating schedule, comparing the responses to a consistent savory lunch-type meal (stewed beans) eaten at the customary afternoon schedule or in the morning. The sensory experience induced by the probe meal, predominantly postprandial satisfaction, was weaker when eaten at an unconventional time  in women. While men were resilient to the changes in the customary eating schedule and experienced the same sensations regardless of the timing of ingestion; the effect of the eating schedule was significantly more pronounced in women for fullness, digestive well-being and mood. This was not associated todifferences in the physiological responses induced by the afternoon and morning meals both in women or men  Figure . Hence, Neurophysiological and brain imaging studies have shown that modulation of visceral sensory input involves a balance between facilitation and inhibition, and this balance is altered in patients with functional gut disorders, leading to visceral hypersensitivity and perception of symptoms in response to physiological stimuli . SpecifiThe digestive tract has a sensory system that detects intraluminal stimuli; sensory receptors in the gut wall are linked to reflex pathways, that regulate gut function, and to sensory pathways, that elicit conscious sensations. Ingestion of a meal activates the digestive system to accomplish the digestive process. The way gastrointestinal stimuli derived from food ingestion are perceived depends on the meal  and the response of the digestive system . Both gastrointestinal sensitivity and function (sensory and reflex responses) depend on intrinsic characteristics of the individual (constitutive factors), but are modulated by a variety of conditioning mechanisms. In normal conditions, meal ingestion induces homeostatic sensations  with a rewarding hedonic dimension (satisfaction). In patients with alterations of gastrointestinal sensitivity and/or impaired control of the digestive function  the postprandial experience turns out to be symptomatic with aversive sensations. Understanding the gastrointestinal contributions to the postprandial experience may help in developing healthy habits, planning dietary interventions and in the management of patients with functional gut disorders.


The strain-generated potential (SGP) is a well-established mechanism in cartilaginous tissues whereby mechanical forces generate electrical potentials. In articular cartilage (AC) and the intervertebral disc (IVD), studies on the SGP have focused on fluid- and ionic-driven effects, namely Donnan, diffusion and streaming potentials. However, recent evidence has indicated a direct coupling between strain and electrical potential. Piezoelectricity is one such mechanism whereby deformation of most biological structures, like collagen, can directly generate an electrical potential. In this review, the SGP in AC and the IVD will be revisited in light of piezoelectricity and mechanotransduction. While the evidence base for physiologically significant piezoelectric responses in tissue is lacking, difficulties in quantifying the physiological response and imperfect measurement techniques may have underestimated the property. Hindering our understanding of the SGP further, numerical models to-date have negated ferroelectric effects in the SGP and have utilised classic Donnan theory that, as evidence argues, may be oversimplified. Moreover, changes in the SGP with degeneration due to an altered extracellular matrix (ECM) indicate that the significance of ionic-driven mechanisms may diminish relative to the piezoelectric response. The SGP, and these mechanisms behind it, are finally discussed in relation to the cell response. Cartilaginous tissues, such as articular cartilage (AC) and the intervertebral disc (IVD), are known to remodel in response to a variety of stresses  or pericellular matrix (PCM) . This electrophysiological mechanism was first observed in bone, whereby the mechanical strain of bone generated differential electrical potentials  and the mechanisms behind it: namely Donnan, diffusion, streaming potentials and piezoelectricity. Both experimental and numerical investigations are discussed in light of the relevant contribution of these mechanisms to the SGP. While many studies have argued that streaming and diffusion potential dominate, an argument is presented herein for the physiological relevance of piezoelectricity in generating and modifying the SGP.Cartilaginous tissues must follow the law of electroneutrality; that is, the tissue must carry a zero net charge. ECM macromolecules in the IVD and AC, however, possess negatively charged surfaces which accumulatively are known as the fixed-charge density (FCD). Proteoglycans are the primary component in cartilaginous tissue that contribute to the FCD. Glycosaminoglycan (GAG) chains, covalently bonded to the proteoglycan monomer, contain negatively charged sulphate and carboxyl groups, creating a net negative surface charge on the GAGs . Mixture theory originates from the work of Truesdell  and TrueThis theory was later expanded to a triphasic mixture theory  is much higher than in the outer AF (1.6:1) or in AC (2:1)  has made investigations of isolated piezoelectric effects in hydrated tissues more attainable. PFM is a variant of atomic force microscopy, whereby an AC voltage is applied by a conductive probe tip in contact with the sample of interest. The electrical field generated results in surface deformation, via the inverse piezoelectric effect, which is measured by deflection of the cantilevered probe. This approach has been used to study piezoelectricity across wide length scales, including bone  are one such mechanosensing pathway that are implicated in this. Chondrocytes in large mammals have a resting membrane potential, of about – 10 mV (Lewis et al. In osteoarthritis, chondrocytes respond differently to loading with different mechanotransduction pathways involved (Millward-Sadler and Salter Difficulties in quantifying the piezoelectric response of cartilage and the IVD has hampered the evidence for its physiological relevance. The reported small values of piezoelectricity may be an underestimation at the macro-scale, as higher shear-piezoelectric responses may be more relevant in modifying other mechanisms in the SGP, particularly the streaming potential. This may be particularly true for degenerated tissues, where a reduced water content, stiffer matrix and altered biomechanics all support a greater role for piezoelectricity. The relevance of the SGP to mechanotransduction is not as clear; a definitive link has been demonstrated but the precise relationship between the magnitude of Donnan, diffusion or streaming potential and the cell response, likely through VGICs, is yet to be elucidated. Further, the relevance of piezoelectricity to the cell response has only been inferred. Numerical models, that have so far neglected ferroelectric effects, could be of great use in this regard, particularly as new evidence supports a direct link between strain and the SGP. Only further investigations, particularly in isolated biological components and comprehensive numerical models, may elucidate the true physiological significance of piezoelectricity.


Wireless sensor networks (WSNs) have demonstrated research and developmental interests in numerous fields, like communication, agriculture, industry, smart health, monitoring, and surveillance. In the area of agriculture production, IoT-based WSN has been used to observe the yields condition and automate agriculture precision using various sensors. These sensors are deployed in the agricultural environment to improve production yields through intelligent farming decisions and obtain information regarding crops, plants, temperature measurement, humidity, and irrigation systems. However, sensors have limited resources concerning processing, energy, transmitting, and memory capabilities that can negatively impact agriculture production. Besides efficiency, the protection and security of these IoT-based agricultural sensors are also important from malicious adversaries. In this article, we proposed an IoT-based WSN framework as an application to smart agriculture comprising different design levels. Firstly, agricultural sensors capture relevant data and determine a set of cluster heads based on multi-criteria decision function. Additionally, the strength of the signals on the transmission links is measured while using signal to noise ratio (SNR) to achieve consistent and efficient data transmissions. Secondly, security is provided for data transmission from agricultural sensors towards base stations (BS) while using the recurrence of the linear congruential generator. The simulated results proved that the proposed framework significantly enhanced the communication performance as an average of 13.5% in the network throughput, 38.5% in the packets drop ratio, 13.5% in the network latency, 16% in the energy consumption, and 26% in the routing overheads for smart agriculture, as compared to other solutions. In various domains, the technology of wireless sensor network (WSN) ,2,3 has During data transmission, the deployed sensors can be static or mobile. The static sensors are also referred to as non-adaptive and their constructed routing tables are fixed. While on the other hand, the routing tables of mobile sensors are dynamic and frequently updated when any change incurs in the network topology. The static routing solutions are more secure when compared to dynamic routing; however, the solutions that are based on the static algorithms are not appropriate for large regions and network scalability ,13. In rThe drastic changes in climate negatively impact the agriculture eco-system causing heaving rains, droughts, floods, and abrupt weather conditions ,21. ThesThis article is aimed at using state of the art IoT based sensor infrastructure to collect data from the environment and securely transfer the data to the BS for efficient decisions. In the proposed framework, wireless agriculture sensors are scattered in the agriculture land for extracting different information related to soil composition, like humidity, temperature, moisture levels, and water level finders. This information is securely transmitted to the cluster heads, which works as memory buffers or storages to forward data towards BS. Upon the reception of data by the BS securely, the BS can provide up to date information to users for an efficient decision with minimum time. The proposed framework offers an energy-efficient and reliable routing to automate agriculture productions with minimum farmer’s burden. The observing data of agricultural sensors are routed towards BS intelligently and securely, which improves the monitoring and productivity of the agricultural land. The simulated experiments for the proposed framework demonstrated outperformed results when compared to existing solutions that are based on different network parameters.This article is outlined in multiple subsections: In the recent era, the technologies of WSN have been applied by different fields because of their low cost, easy deployment, and cost-effective environment ,26. In WIn WSN ,31,32, mAuthors  proposedThe authors  proposedIt is seen from the discussed studies that sensor nodes are very limited in terms of battery power, transmission, storage, and processing resources. Additionally, it is not possible to replace the components of the sensor nodes in dense and large regions. These low powered sensor nodes have significant impact on the performance of the network in terms of delivery ratio and energy consumption. Furthermore, most of the WSN based smart agriculture applications need the required information in an efficient and timely manner. Therefore, optimizing network lifetime with stable routing and data delivery performance are most of the important research challenges in WSN based applications. Additionally, the selection of cluster heads performs a very important role to balance the load distribution and energy consumption in the WSN based agricultural land. The cluster heads that are one hop away from BS exhaust their energy resource much quickly and lead to the energy hole issue, which degrades network throughput and increases the latency ratio. Moreover, it is observed from the existing work that most of the solution does not consider the strength of the signal in data routing, which significantly increases the packet drop ratio and instability in the network region. Accordingly, most of the energy power of sensor nodes is dissipated due to the selection of poor wireless carrier channels and it leads to frequent retransmissions of agricultural sensors’ data. Furthermore, end users obtained the information from the IoT based WSN while using the Internet, which is full of malicious actions and network information can be disclosure to anonymous nodes. Therefore, data security is another important research aim for a WSN based smart agriculture to achieve network reliability and trustworthiness. Consequently, an energy-efficient and secure IoT based WSN framework must be layout and developed for smart agriculture to optimize network lifetime with reliable delivery performance to end-users. Besides, a trustworthy mechanism can increase the security of individual sensors and formulate realistic end-to-end routing paths. Therefore, the combined concept of energy efficiency with lightweight data security among the low power sensor nodes can improve the efficacy of the IoT-based WSN framework for smart agriculture. Several researchers have used the technology of WSN in various domains to sense the environmental data. WSN has also played a vital role in the observation and management of agricultural land in terms of crops, climate, water usage, etc. However, the agricultural land still has some challenges, such as energy efficiency, data routing, and security, due to the limited battery power of sensors and open transmission medium. The basic aim of the proposed solution to develop an energy-efficient and secure IoT based WSN framework for the monitoring and production of agricultural land. In the proposed framework, an appropriate clusters heads are selected based on the optimal decision function. Furthermore, the SNR factor also incorporated in the decision to compute the strength of wireless signals and increase the successful ratio of sensors packets. Our proposed framework offers reliable and energy-efficient methods for the improvement of large-sized agricultural land. Moreover, the proposed framework also accumulated the data security among agricultural sensors to cluster heads and from cluster heads to BS based on secret keys while using the linear congruential generator ,47, whicThe research design of the proposed framework is explained in this section. The proposed framework comprises of two main components. In the first component, the agricultural sensors are dispersed to gather information. The sensor nodes are heterogeneous in terms of residual energy, such that the energy level of the heterogeneous nodes is higher than normal sensor nodes. The agricultural sensors are dispersed into various distant areas and each area consists of one cluster head. The role of the cluster head is to receive the information from agriculture land and forward towards BS in a fault-tolerant and energy-efficient manner. The proposed framework balances the load among agricultural sensors and it selects suitable cluster heads based on multi-criteria decision function. Moreover, our proposed framework makes use of a single-hop transmission instead of a multi-hop paradigm to reduce the network bottlenecks and network latency. In the second component, the proposed security mechanism exploits symmetric data encryption between agricultural sensors and presents a robust transmission in the field using pseudorandom number generation. All the agriculture sensors and BS remain fixed after the nodes deployment.Transmission links are symmetric.Agriculture sensors are heterogeneous in terms of energy resources.BS has the most powerful node with unlimited resources.The location of agriculture sensors is determined using Global Positioning System (GPS).Before discussing the proposed Energy Efficient and Secure IoT Based WSN Framework for Smart Agriculture, some network assumptions are highlighted, as follows:This section presents discussion on the design of the proposed energy and link efficient routing, which includes two main levels. The first level is based on a multi-criteria decision function for the selection of optimal cluster heads. Afterwards, the least energy consumption nodes are formulated into different clusters. The second level of the proposed energy and link efficient routing is to make the routing channel more stable for a longer time, which prevents the wireless link from misbehaving activities from cluster heads to the BS. Our proposed framework uses the node energysing SNR ,49 is thThe value of In the proposed framework, BS maintains a global table that comprises information regarding agricultural sensors. The store information consists of node position, distance from BS, residual energy and SNR factors. Based on the stored information, BS evaluates In the proposed framework, data from the agriculture sensors are routed while using a secure and trusted network towards the cluster heads and further towards the BS. In this framework, the BS generates secret keys using the recurrence of the linear congruential equation that is given by Equation (2).This section presents the default simulation parameters ,51,52 thThe section explains the experimental results between the proposed framework and the existing solution. The performance of the proposed framework with other solutions is measured based on network throughput, packets drop ratio, network latency, energy consumption, and routing overheads.In In In The technology of wireless sensor networks performs a vital role in the development of the agriculture domain. This paper presents an energy-efficient and secure IoT based WSN framework for smart agriculture application. The main aim of the proposed framework is to appoint the more suitable cluster heads based on multi-criteria decision function. The decision is based on residual energy, distance to BS, and SNR factors. Additionally, the proposed framework is to adopt a single-hop paradigm for data transmission and decreases the chances of bottlenecks among agriculture sensors and BS. Our proposed framework presents an intelligent decision for data routing and decreases the ratio of energy consumption with improved data delivery performance in the agriculture field. Unlike most of the existing solutions, the proposed framework exploits a mechanism that is based on the SNR factor to determine the strength of signals and it achieves more stable network performance between agriculture sensors and BS. Moreover, the proposed framework offers secure data transmission from agriculture sensors towards BS based on secret keys while using the recurrence of the linear congruential generator. In future work, we aim to analyze the performance of the proposed framework in a mobile-based IoT network and Intelligent Transportation System (ITS).


During the metastatic progression, invading cells might achieve degradation and subsequent invasion into the extracellular matrix (ECM) and the underlying vasculature using invadopodia, F-actin-based and force-supporting protrusive membrane structures, operating focalized proteolysis. Their formation is a dynamic process requiring the combined and synergistic activity of ECM-modifying proteins with cellular receptors, and the interplay with factors from the tumor microenvironment (TME). Significant advances have been made in understanding how invadopodia are assembled and how they progress in degradative protrusions, as well as their disassembly, and the cooperation between cellular signals and ECM conditions governing invadopodia formation and activity, holding promise to translation into the identification of molecular targets for therapeutic interventions. These findings have revealed the existence of biochemical and mechanical interactions not only between the actin cores of invadopodia and specific intracellular structures, including the cell nucleus, the microtubular network, and vesicular trafficking players, but also with elements of the TME, such as stromal cells, ECM components, mechanical forces, and metabolic conditions. These interactions reflect the complexity and intricate regulation of invadopodia and suggest that many aspects of their formation and function remain to be determined. In this review, we will provide a brief description of invadopodia and tackle the most recent findings on their regulation by cellular signaling as well as by inputs from the TME. The identification and interplay between these inputs will offer a deeper mechanistic understanding of cell invasion during the metastatic process and will help the development of more effective therapeutic strategies. Therefore, the ability of tumor cells to sense and migrate in response to receptor signals is required to restrict actin remodeling events and to coordinate in time and space cytoskeletal signaling proteins, eliciting invasive protrusions. Here we describe the main receptor families involved in invadopodia .Members of the large family of receptors with tyrosine kinase activity (RTK) are key regulators of cancer cell growth, proliferation, and survival, as well as invasion and metastasis . There iin vivo metastasis, indicating that the reactivation of developmental machinery, such as the EMT, in tumor metastasis might act in cooperation via invadopodia (Platelet-derived growth factor receptor α (PDGFα) is an important effector of invadopodia in aggressive human breast tumors , and repadopodia . In pancadopodia . Finallyadopodia .G protein-coupled receptors (GPCRs) are heptahelical membrane proteins, which classically transmit the signal via the activation of heterotrimeric G proteins . They arIn the GPCR family, the lysophosphatidic acid (LPA) receptor has been demonstrated to operate invadopodia formation. For instance, the secretion of Autotaxin, a major enzyme involved in the production of LPA, drives the activation of LPA4 receptor and subsequent activation Rap1/Rac1 signaling, acting as a strong inducer of invadopodia, and correlating with the ability of fibrosarcoma cells to invade and metastasize . In ovarA) or type B (ETB) receptor, the small peptide endothelin-1 (ET-1), recognized as a critical regulator of different human cancers  are the main source for synthesis, secretion, and assembly of the ECM components, and hence critically involved in the modification of the ECM composition and organization. Besides their architectural role in providing an anchorage and support to the surrounding cells, ECM proteins transmit signaling which is interpreted and transduced by specific cell receptors . AlthougBesides its biochemical composition, biophysical characteristics of the ECM, including topography, stiffness/rigidity, molecular density, and tension, are strongly subject to remodeling under the influence of tumor stroma and cancer cells. Cancer cells adapt to mechanical alterations of the local stroma by transducing them into biochemical signaling events that guide and reinforce the invasion of cancer cells . Hence, These data suggest that invadopodia are plastic structures, highly adaptable to the matrix microenvironment and acting as matrix mechanosensory, thus reflecting the ability of the cells to exploit and invade different types of tissues and matrices and that mechanical stimulation may accelerate the rate of the maturation process enhancing cell invasion.In the tumor microenvironment, the reciprocal physical interaction between cancer and surrounding stromal cells represents a factor promoting invadopodia. CAFs play an important role in tumorigenesis, and their interaction with tumor cells occurs at several interfaces, including the production of ECM proteins, the release of nutrients, and cytokines that facilitate the metastatic progression. The complex and mutualistic interactions between tumor cells and neighboring fibroblasts are critically involved in matrix-degrading proteases secretion and ECM remodeling. Fibroblasts itself can degrade matrix independent of invadopodia, supporting invasion indirectly through mechanical regulation, or serving as “leader” cells . In the Metastasis-associated macrophages (TAMs) are other key elements of the TME that significantly affect cancer cell motility and metastatic behavior. Throughout the metastatic cascade, a subset of TAMs accumulates within metastatic sites and the interaction with cancer cells allows them to invade, intravasate into the blood vessels and extravasate into secondary sites, by producing factors fueling cancer invasion and metastasis . SeveralThese findings underscore the importance of fully understanding the contributions of the crosstalk between stromal cells and cancer cells in the tumor microenvironment, underlying the molecular and physical mechanisms regulating matrix remodeling, and invadopodia.2+) signaling, thus representing an interesting actor in invadopodia field and a potential therapeutic target (2+ microdomains the activation of Pyk2 initiates Src signaling cascade required for invasion (Cancer and stromal cells in TME are immersed in the metabolic conditions characterized by acidosis and low-tension oxygen, known as hypoxia, both considered central issues in tumor metastasis since in these conditions cancer cells have a higher tendency to metastasize . Indeed,c target . Basicalc target . By usinc target . Moreoveinvasion . In glioinvasion . Moreoveinvasion , and futTumor plasticity provides a new explanation for the mechanisms of invasion, metastasis, and recurrence, suggesting that interfering with the mediators of tumor plasticity is a becoming strategy to treat malignant tumors. During cancer progression, malignant cells must encompass different barriers requiring the dynamic interactions of cancer cells with the microenvironmental elements, including embedded stromal cells. Mechanical and biochemical interactions are associated with the generation of intracellular contraction forces that in turn restructure the surrounding TME. At the interface between cancer cells and metastatic processes, invadopodia are plastic structures with the ability to adapt their functions to respond to cellular and microenvironmental changes. Emerging evidence demonstrated that invadopodia are essential for cancer cell intravasation  and extrSignificant advances have been made in understanding how invadopodia formation and activity triggered, for instance, by growth factor receptors are subject to different mechanisms of regulation, depending on the type of cells in which receptors are expressed and activated, as well as on the TME. We have learned that some molecular mechanisms and signaling pathways involved in invadopodia regulation are shared among different receptors while others are purely receptor-specific, cooperating with each other’s and with microenvironmental conditions. We now appreciate how the crosstalk between cancer cells and the biochemical and mechanically altered TME impacts invadopodia and tumor progression, since invadopodia sense and respond to the physical environmental properties through mechanotransduction processes, which in turn may impact the TME. These findings point to an important need to integrate the knowledge of how highly invasive cells could discern the multitude of biochemical and biomechanical cues, and extend our knowledge beyond those cues currently recognized to promote cancer progression.in vivo and to establish how signals from growth factor receptors cooperate with signaling from intracellular structures and the rest of the microenvironmental machinery, to provide an integrated perspective which can be translated in therapeutic approaches in cancer. As our understanding of biochemical and biomechanical cues encountered the cancer cells to control invadopodia formation/activity evolves, we will take us closer to find novel means to predict outcomes and evaluate therapeutic targets and approaches to control metastatic cancer, by blocking also invadopodia.More in depth studies are needed to appreciate overall of invadopodia regulation, to evaluate the relevance of individual mechanisms IM, VC, and AB contributed to manuscript writing. IM designed figures. LR wrote and edited the review. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.