Modern instrumentation for Raman microspectroscopy and current techniques in analysis of spectral data provide new opportunities to study molecular interactions and dynamics at subcellular levels in biological systems. Implementation of biomolecular component analysis (BCA) to microRaman spectrometry provides basis for the emergence of Ramanomics, a new biosensing discipline with unprecedented capabilities to measure concentrations of distinct biomolecular groups in live cells and organelles. Here we review the combined use of microRaman-BCA techniques to probe absolute concentrations of proteins, DNA, RNA and lipids in single organelles of live cells. Assessing biomolecular concentration profiles of organelles at the single cell level provides a physiologically relevant set of biomarkers for cellular heterogeneity. In addition, changes to an organelle’s biomolecular concentration profile during a cellular transformation, whether natural, drug induced or disease manifested, can provide molecular insight into the nature of the cellular process. Molecular organization and regulation of eukaryotic cells is based on highly organized subcellular structures of specialized functions i.e., organelles. To advance the understanding of cellular regulation and disease development, there is a high demand for bioanalytical techniques capable of studying the link between the subcellular biomolecular composition of organelles and physiologic or pathologic cell functions. Currently, this demand is met by proteomics, metabolomics, lipidomics and other “omics” disciplines ,2, whereRaman light scattering from different types of biomolecules generates corresponding bands in the Raman spectra, which enables to resolve all the diversity of biomolecular components—nucleic acids, amino acids, proteins, and various classes of lipids and saccharides. Being applied to live cells, it provides multiple benefits for molecular analysis, including the linearity of this optical phenomenon, which allows for quantitative probing of biomolecular distribution ,4. This Technological advances in Raman spectroscopy hardware  have significantly boosted the sensitivity of this analytical method. Since the time when the first studies on living cells were performed using Raman microspectroscopy , Raman sFor bioapplications this method is known as Biomolecular Component Analysis (BCA), a powerful algorithm that identifies the concentration of different molecular groups collectively contributing to the Raman spectrum of the biological sample. BCA is successfully used in a wide range of studies, including biomolecular probing of single cells and tissue samples. Being applied to different cellular organelles, BCA creates a solid foundation for subcellular Ramanomics. Although it is well known, the novelty of BCA, highlighted in this review, is the scoring the spectral features of the organelles in order to understand and identify the cellular states and different cell types. Biomolecules  and their ratios present in different organelles give rise to a library of spectral patterns, which may be used to define unique cell types or cellular states. Recent progress in BCA development and further perspectives of this technique are discussed below.The Raman spectrum of a live cell carries unique information about the molecular composition of volume, where light interacts with cellular constituents. This information can be extracted by using a set of mathematical techniques, which may be incorporated in modern spectrometers as statistical toolboxes, or as stand-alone analytical software. These techniques, or multivariate analysis tools are discussed in details in several original papers and reviews on Raman spectroscopy and could be found elsewhere . Brieflyith component. The weights, or the specific contributions of the each component into model One of the most popular implicit methods, Principal Component Analysis (PCA), creates a small set of specially chosen base spectra, i.e., the principal components, which explain/reveal all of the spectral changes in a sample’s Raman spectrum. The first principal component carries the maximum variance in the data, while the last principal component represents mostly noise. A linear combination of the weighted principal components serves as a model of the measured spectra. If spectral bands of the principal component overlap with that of specific biomolecular spectrum, then the principal component weights (scores) can be used for evaluation of relative concentration of such chemical. The results from PCA are commonly used in various cluster analyses of spectral variations. For some medical conditions, when the changes in the Raman spectra correlate with the disease progression, this cluster analysis accurately provides a valuable database to classify samples, clinical diagnostics and staging ,22. HoweThe advantages of using BCA over any implicit analysis method can be demonstrated with the following example. The same Raman data measured in two different organelles, nucleoli and mitochondria, of HeLa cells were analyzed using the PCA and BCA techniques .As demonstrated in In comparison, analysis of the same set of data with BCA delivers more abundant information of the biomolecular composition of the organelles. BCA was able to identify the local concentration of proteins, RNA, and lipids for each organelle, as well as of glycogen in mitochondria. The data also indicate a weak concentration of DNA in each organelle, although it is below the limit of detection threshold. BCA detected significant differences in the biomolecular makeup of nucleoli and mitochondria d,e. BCA Based on this simple example, we can summarize that BCA definitely outranks PCA in its analysis capabilities. Although BCA has not been widely used by the biomedical scientific community, and, as follows from publications, is little known in comparison to PCA. The reason for this will be discussed in the next section.Generally, the requirement to know all the chemical components of the cellular compartment for modeling a priori is challenging. The composition of intracellular environment is complex and variable, and it requires a significant effort to choose the proper set of component spectra to have a satisfactory model fit to the real spectrum. Depending on the accuracy of this component set, the proximity of fitting between the measured spectrum and the model spectrum will be close, but the model may not represent reality. In practice, model validation is necessary to establish how accurately the spectral fitting has been performed. Usually the residual profile between the model and the real spectrum can be used as a merit of the model quality. In this regard, to overcome the challenge of biochemical diversity in a live cell to properly model the complex Raman spectrum, the number of components can be limited to those which significantly contribute to the resulting Raman intensities. Evaluation of other minor contributors can be studied by analysis of the residual profile.Besides assuming the number of Raman components used in modeling and the real number of biomolecules of a particular type at that particular location, another major source of the residual spectrum arises from the distinction between Raman biomolecular spectra in the sample and that in the corresponding model. Variations in the amino acids composition of proteins, nucleotide sequences in DNA and RNA, different lipids, small molecules and ions will all introduce variations to the measured Raman spectrum. The use of real Raman spectra of biomolecules as model components is an optimal choice for the modeling. However, in this case, the procedure of the extraction of full set of organellar molecular constituents is required, which is in practice extremely difficult. Isolation and purification of organellar proteins is a sophisticated procedure , accompaConsidering the challenges discussed above, there is a common strategy to appropriately deconvolute a cellular Raman spectrum when using BCA—the establishment of biomolecular components and their Raman profiles, whose contribution in resulting Raman intensities is significant. To our knowledge, an implementation of this strategy has not been completed, which impedes the wide application of BCA for biomedical applications. Besides, there are two other important issues for satisfactory BCA employment. First, the removal of the uncontrollable background accompanying the weak Raman signal of bio-constituents, which can distort spectral shape and compromise further analysis. Second, the calibration procedure, which is required for absolute concentration probing.Further, we will review and discuss the methods to overcome these issues, which are important steps for standardization of the BCA protocols, and are necessary to implement a BCA toolbox for Raman spectrometers.In practice, most publications on biomolecular modeling of intracellular Raman spectra are based on a set of the major classes of macromolecules—proteins, nucleic acids, lipids and saccharides, which collectively make major contribution to the non-elastic scattering intensities ; therebyS. cerevisiae RNA, Calf liver RNA, and/or t-RNA) solutions can be used for the measurement of their respective Raman component profiles [Nucleic acids. Nucleic acids, in spite of difference in sequences and secondary structures, have similar Raman spectra . In thisprofiles ,34,39,40profiles .Lipids. Combination of two compounds  are within 5%, except at the edges (<680 and >1700 cm−1), which is close to standard error for Raman measurements in a uniform protein sample  protein component for biomolecular analysis of nucleolus, often results in larger intensity in the residual profile . This ouThis step is important to analyze bio-constituents in absolute concentrations. All Raman micro-spectrometer systems differ from each other by photodetector sensitivity, dispersion of spectrometers, and optical losses in excitation and detection channels. This requires calibration of absolute biomolecular component concentrations for each device. Usually this procedure includes careful measurement of Raman spectra of biomolecular solutions with known concentrations. Then calculated from the calibration curve, which is linearly dependent on Raman spectra intensity (in CCD counts) on concentration, a biomolecular concentration value is assigned to each specific component spectrum. Calibration of micro-spectrometers is usually performed by measuring Raman spectra of the solutions of the commercially available biomolecular products with known concentration.The sources of uncontrollable background generated during confocal Raman measurements of bio-constituents are: (i) Raman scattering from the substrate and the medium; (ii) light scattering, other than Raman; (iii) intrinsic fluorescence (autofluorescence) of biomolecules; and (iv) detector dark noise.2, BaF2 or MgF2) are able to reduce the background signal, generated by substrate itself [The most direct strategy to reduce the Raman spectra background is using a combination of: (i) appropriate laser excitation wavelength; and (ii) proper substrate material for cell growth . Lasers e itself ,37. UnfoThe post-processing algorithm to remove the background from the recorded spectra is generally accomplished by subtraction of preliminary measured spectrum of the medium (buffer) or empty sample cell, and spectrum of fluorescence, which can usually be modeled with a polynomial filter ,36,37,38All background components, accurately recorded, smoothed and normalized, can be added to the set of biomolecular spectral components see  for the A nonlinear least squares algorithm or its modification (Levenberg-Marquardt) is usually used to fit the model to the measured Raman spectra ,36,37,38Early BCA applications were mostly devoted to the classification of cancerous and noncancerous cells based on the differences of biomolecular content. Both PCA and BCA methods were utilized to analyze the Raman spectra measured from live, apoptotic, and necrotic leukemia cells . Ong, etIn addition, BCA has been used to estimate biochemical changes due to necrosis in MEL-28 human melanoma cells growing in vitro . A decreOne important application of BCA is the ability to verify the suitability of immortal cultured cell lines as models for primary cells. The use of primary cells can be hampered by an unreliable supply; the difficulty of performing isolation and culture procedures in vitro; limited division number and loss of phenotype with increasing time in culture. To overcome these limitations, BCA was used to characterize live A549 cells as a model for primary human pulmonary alveolar type II epithelial cells (ATII), and a transduced type I (TT1) cell line as a model for alveolar type I (ATI) cells . The resBiochemical assessment of cellular and extracellular morphologic structures in situ is one of the efficient methods to discriminate between normal and abnormal tissue sites. BCA was employed to obtain quantitative chemical information on coronary arteries and to develop diagnostic algorithms that accurately discriminate between nonatherosclerotic tissue, noncalcified plaques, and calcified plaques on the basis of relative weights of calcium salts and total cholesterol . This meRaman microspectroscopic modeling of human breast tissue was employed for breast cancer diagnosis in vivo . Lipid qHigh 3D resolution of confocal Raman microspectroscopy makes it an appropriate analytical tool for local molecular composition, suitable for quantitative biomolecular analysis and real-time biomolecular monitoring in distinct subcellular structures such as cytoplasmic organelles and structure–function compartments of the cell nucleus.Confocal Raman microscopy does not always ensure accurate probing of subcellular structures due to difference between the size and shape of organelles and the probing dimensions. Besides, several large organelles including nucleoli, mitochondria, Golgi complex, and endoplasmic reticulum, are non-uniform, and some variation in the Raman spectra can be detected in the different parts of the same organelle. Nevertheless, the spectra obtained in the same type of organelle demonstrate a significant similarity, which may be associated with specific molecular microenvironment in these subcellular structures.The first application of BCA in organellar analysis, to the best of our knowledge, was performed by our group at the Institute of Lasers, Photonics and Biophotonics (ILPB), the University at Buffalo. In the most of our studies we used our BCA toolbox coded in Matlab software. Raman spectral concentration calibration was performed using bovine serum albumin, calf thymus DNA, S. cerevisiae RNA , and bovine heart lipids , with unit weight of 100 mg/mL for proteins and 20 mg/mL for RNA, DNA and lipids concentrations. The BCA toolbox yields a set of biomolecular weights  and residual profile for each analyzed spectrum. Representative BCA processed spectra and output data are shown in We used this method to study the macromolecular organization of the cell nucleus throughout the cell cycle in HeLa cells. In this study, site-specific concentrations of proteins, DNA, RNA, and lipids were estimated in nucleoli, nucleoplasmic transcription sites, nuclear speckles, constitutive heterochromatin domains, mitotic chromosomes, and extrachromosomal regions of mitotic cells . We wereAs a continuation of our site-specific probing strategy, we focused on the characterization of complex molecular organization of the nucleolus, which is the largest structure–function compartment of the cell nucleus . BCA wasNext, we have demonstrated that microRaman-BCA enabled real-time monitoring of RNA synthesis in the nucleoli of live cultured cells . In thisThe nucleolar molecular signature was also compared between primary human skin fibroblasts, induced pluripotent stem cells (iPSCs) derived by reprograming of skin fibroblasts, and human embryonic stem cells . In thisSubsequently, we chose to study the transformations of the macromolecular landscape in the mitochondria during DNA-damage-induced apoptotic cell death . During As we discussed above, the ‘cellular proteins’ component corresponds to the remaining spectrum obtained after the subtraction of the model weighted spectra of DNA, RNA, lipids (and saccharides in cytoplasm) from the measured spectra of the organelle. Usually this Raman profile contains integral Raman contributions from (i) a variety of different type of proteins; (ii) minor bio- and other molecular components; and (iii) spectral deviations of model components  from real biomolecular components. In the last case, the accuracy of the analysis depends on the choice of component spectral profiles, and the presence of misfit can be manifested in systematically appearing bands in the residual spectra, co-located with major spectral bands of these biomolecular components. This shows how component spectrum correction can increase the accuracy of the model fit.Minor molecular components, presenting at negligible concentrations, make insignificant contribution to the integral Raman signal, just increasing background. However, abundant cellular proteins make overwhelming contribution to the “proteins” model component. A comparison of the normalized protein component, obtained in different organelles, or for the same organelle in different cells, allows for the analysis of specific differences other than the deviations of biomolecular concentrations. For example, a comparative analysis of Raman profiles of HeLa nucleolar protein component and BSA  showed sSystematic studies of protein components in three major cellular organelles—nucleoli, endoplasmic reticulum and mitochondria, reveal substantial spectral differences of organellar proteomes, while protein spectra of the same type organelle in different cell lines demonstrated less obvious differences .The BCA technique allows for uncovering of changes of protein component occurring in the course of severe cellular alterations induced by external impact or internal processes. For example, ethanol fixation triggers a decrease in the α-helical structure of nucleolar proteins and an increase in the β-sheet conformation fraction of the proteins . ChangesThe structural analysis of proteins of mitochondria during apoptosis  demonstrA shift to the individual organelles as a target for Raman microspectrometry, brings a new dimension of this technique for bio-applications. Being oriented as a specific-organelle tool, microRaman-BCA can be classified as an omic technology, aimed at collectively characterizing and quantifying pools of organellar biological molecules and, thus, provides information on cellular processes including metabolism, cell response to external factors and drug-cell interactions. At the same time, this method is relatively underrepresented in research labs due to the reasons discussed in In our opinion, it is quite feasible to establish the set of universal biomolecular component profiles, which can be used for general BCA of the organelles suitable for confocal Raman measurements, and to develop a user friendly interface of BCA software together with visual control of modeling quality.As the first step for implementation of the BCA unit in commercial micro-Raman systems, we developed a semi-automated BCA toolbox for a microRaman spectrometer to generate biomolecular datasets of subcellular sites of mammalian cells in real time, which can be used in further statistical and correlation computations. The software toolbox was coded in Matlab and has an input dataset, which includes Raman components for three cellular organelles . We verified the capabilities of microRaman-BCA toolbox for molecular profiling at a single organelle level in normal and cancer cell lines . PrelimiThe key goal of further research is to establish the BCA-based Ramanomics as an independent omics discipline, harnessing its unique capabilities for non-invasive analysis of subcellular structures, by integrating it together with conventional bioanalytical techniques. Collaboration between academic research groups and manufacturers of Raman hardware would make a significant contribution to achieve this goal.


This paper investigates the impact of using directional antennas and beamforming schemes on the connectivity of cognitive radio ad hoc networks (CRAHNs). Specifically, considering that secondary users use two kinds of directional antennas, i.e., uniform linear array (ULA) and uniform circular array (UCA) antennas, and two different beamforming schemes, i.e., randomized beamforming and center-directed to communicate with each other, we study the connectivity of all combination pairs of directional antennas and beamforming schemes and compare their performances to those of omnidirectional antennas. The results obtained in this paper show that, compared with omnidirectional transmission, beamforming transmission only benefits the connectivity when the density of secondary user is moderate. Moreover, the combination of UCA and randomized beamforming scheme gives the highest path connectivity in all evaluating scenarios. Finally, the number of antenna elements and degree of path loss greatly affect path connectivity in CRAHNs. These networks are composed of devices that are self-organizing and can be deployed without infrastructure support. Due to the proliferation of wireless devices, the industrial, scientific, and medical (ISM) bands are getting congested. Therefore, the efficiency of spectrum usage has become a major concern. To maximize the benefit of usable radio spectrum, spectrum management is needed. However, recent studies highlight that a large percentage of licensed band remains unused because those spectrum bands are allocated through static assignment policies but only used in bounded regions or over a limited period of time. To deal with such bandwidth scarcity and inefficient bandwidth usage, the concept of nized in  as an efm fading is analyzed in [Connectivity is a fundamental property of ad hoc networks (AHNs). The connectivity of CRAHNs is different and more challenging compared with conventional AHNs because secondary users have to opportunistically utilize the licensed spectrum band of primary users. There have been extensive studies on the connectivity of conventional AHNs ,3,4,5,6.thors in  present lyzed in ,9,10,11.algebraic connectivity. Firstly, a connection graph of CRAHNs is built. Then, the second smallest eigenvalue of the Laplacian of this graph is used to evaluate the influence degree of PUs on the communication probability among SUs. Local connectivity, i.e., node degree and isolation probability of SU with Gaussian noise and path loss model are investigated in [Recently, researchers have been attracted to investigating the connectivity of CRAHNs. In , the autgated in  by emplogated in  give thegated in ,16, respgated in ,9,10,11 gated in ,18,19, tThis observation motivates us to evaluate whether beamforming always benefits the connectivity of CRAHNs like the case of AHNs. If not, then when, how, and why the usage of directional antennas and beamforming schemes increases or decreases the connectivity of CRAHNs by comparing it to the CRAHNs with ominidirectional antennas.We examine the combined influence of different antenna types and beamforming schemes on the path connectivity of CRAHNs. Particularly, we consider how SUs equipped with two popular directional antennas, i.e., uniform linear array (UCA) and uniform circular array (UCA) antennas, communicate with each other by using two simple and efficient beamforming schemes, i.e., randomized beamforming and center directed beamforming. Especially, we show that, in contrast to AHNs, using beamforming in CRAHNs does not always improve network connectivity. To be more specific, in all evaluating scenarios, only the UCA antenna gives higher path connectivity than omnidirectional antennas.We show that the influence of beamforming on path connectivity greatly depends on the degree of channel path loss. Specifically, when path loss exponent We find that the number of antenna elements of directional antennas significantly affects path connectivity. For each type of directional antenna, the number of antenna elements, at which the highest path connectivity is obtained, is different.The main contributions of this paper are:The results in this paper provide insights into how beamforming changes the connectivity characteristics of CRAHNs under path loss and Rayleigh fading and helps network designers to select the appropriate directional antenna and beamforming scheme in order to maximize network performance of CRAHNs.The rest of this paper is organized as follows. r.In this paper, we consider two directional antennas, i.e. Uniform Linear Array (ULA) and Uniform Circular Array (UCA) antennas. The ULA comprises of antenna elements separated a distance of Since each single element is ominidirectional antenna, For an array antenna, its far-zone electric field is calculated by multiplying the electric field of single element by the array factor of that array, that is,Then, the gain of an array antenna can be expressed as a function of its array factor, namelyM represents the number of antenna elements, The array factor of ULA antenna is given by ,21(3)AFSince the physical center of the ULA antenna is often chosen as the reference point when calculating its array factor; thus, Equation  becomesM and azimuthal angle By plugging Equation  into Equr is the radius of the circle formed by the antenna elements, m-th element, respectively.The array factor of UCA is expressed as ,21(5)AFm-th element is selected such thatTo have the peak of main beam stare at  and uniform circular array antennas as in The communications between a specific SU and other SUs occur when all of its neighboring PUs are in the OFF state, i.e., the overlay transmission mode ,16.u is Rayleigh distributed random variable and The wireless link between two nodes are described as follows. One node transmits signal with power essed as (9)fU(u)Hence, the received power given by ,23(10)PIt should be noticed that when nodes are equipped with directional antennas, the antenna gains of transmitter From Equation , the sigd is less than a specific threshold Thus, when the signal power attenuation between two nodes separated at a distance We study the influence of directional antenna and beamforming schemes on the path connectivity between two random SUs in CRAHNs. Two aforementioned array antennas are used in two beamforming schemes to evaluate in what conditions beamforming schemes benefit the connectivity of CRAHNs.Randomized beamforming: This beamforming scheme is considered as the simplest one, i.e., each node chooses the direction of its main beam from Center-directed beamforming: According to this beamforming scheme, it is required that all nodes know the center of network area. Then, they point their main beams toward the network center.Because of no additional signaling for the information of neighboring location and beam direction, these beamforming schemes are efficient in CRAHNs where the routing and spectrum sensing process already employ a lot of control messages. Investigating the effects of the randomized beamforming scheme and the center-directed beamforming scheme on the connectivity of ad hoc networks is presented in ,8, respeWe are interested in the questions: does a directional antenna always benefit the connectivity of CRAHNs? What kinds of antennas and beamforming schemes benefit the connectivity of CRAHNs? Moreover, since the number of antenna elements remarkably changes the antenna gain pattern, we also investigate the optimal number of antenna elements that provides the highest connectivity.In this section, we conduct Monte Carlo simulation by running MATLAB  codes on a computer to investigate the effect of beamforming on the path connectivity in CRAHNs. Similar to previous works ,14,15,16 path as (13)PpatWe will compare the connectivity performance found in  for AHNsfound in  for CRAHa, and number of SUs, The effect of the average active rate of PU, M, of directional antennas greatly affects their gain patterns, which definitely influences the overall network connectivity. M increases from 1 to 10. It should be noted that M = 1 corresponds to the omnidirectional antenna. As can be seen in M ≤ 3, the levels of path connectivity of UCA-random and UCA-center are lower than ULA-random because, when M is small, the gain pattern of UCA has more high-gain side beams compared with ULA. ULA-center has the lowest path connectivity because, with two symmetric main beams of ULA, using the centralized beamforming scheme may remarkably create a high possibility of interfering with PUs. As M increases, the gain pattern of UCA now consists of only one high-gain main beam and considerably small-gain side beams, which is efficient in cognitive networks. Generally, UCA-random yields better path connectivity than the others, and reaches the highest value of 0.94 when M = 5.As observed in We now evaluate the combined effect of beamforming and the degree of path loss on path connectivity in CRAHNs. From We have studied the effects of different combinations of directional antennas and beamforming schemes on the path connectivity between two arbitrary SUs in CRAHNs. Particularly, two directional antennas, i.e., ULA and UCA, and two beamforming schemes, i.e., randomized beamforming and center-directed beamforming, are employed. The results on path connectivity of beamforming scenarios are compared with those of omnidirectional antenna to evaluate in what conditions beamforming increases or decreases path connectivity between two arbitrary SUs in CRAHNs. We discover some important and interesting features which can be summarized as follows. First, using beamforming transmission for SUs only shows noticeable benefits in terms of path connectivity of a secondary network when SU density is moderate. Second, the combination of UCA antenna and randomized beamforming provides the highest connectivity compared with others. Third, the number of antenna elements and degree of path loss greatly influence the path connectivity. The results in this paper give insights on how beamforming affects path connectivity in CRAHNs. An important feature is that using any kind of directional antennas does not always provide higher path connectivity compared with ominidirectional antennas. Thus, this paper can help network designers select proper directional antenna configuration and beamforming schemes to achieve the highest path connectivity in CRAHNs. Carrying out our real experiments to measure the path connectivity and comparing the measured results with the simulation results obtained in this paper are considered part of our future work.


Gastrointestinal disorders are among the most common illnesses that affect people nowadays. Their prevalence and incidence have been on the rise during the last decade. This high prevalence and incidence are due to the contemporary lifestyle we live. Such lifestyles include bad dietary habits, consumption of drugs, alcoholic drinks, and stress. It is very common that gastrointestinal disorders are characterized with inflammatory and ulcerative processes from the stomach or gut.The main inflammatory and ulcerative disorders associated with the gastrointestinal tract include gastritis, ulcers, colitis, Crohn's disease, and mucositis. These disorders are difficult to treat. The recurrence and side effects are very common after treatment with available drugs. Based on that, there is an urgent need for the search for more effective and safe pharmacological options for the treatment of inflammatory and ulcerative gastrointestinal disorders. In the recent years, plant extracts and natural products have been sought for the important role in the treatment of the previously mentioned disorders. Thus, a great deal of effort and research has been undertaken to find suitable natural plants and compounds with proven potential. For this reason, hundreds of plant extracts and isolated active compounds have shown a promising potential. However, for the majority of them, it is necessary to conduct preclinical studies followed by the clinical studies in humans in order to be approved for human use. This special issue is focused on this topic. The edition consists of seven articles including a clinical study, three preclinical studies, and three reviews, which are briefly described below.The clinical study was performed by B. Liu et al., who reported that the use of Chinese medicinal herbs mix composed of seven plants (CIF) and mesalazine in the treatment of ulcerative colitis (UC). In this study, 60 patients with chronic UC were treated only with either oral mesalazine or mesalazine in combination with CIF enema. The results showed that combination of mesalazine and CIF significantly improved the clinical symptoms, the colon mucosal conditions, the Mayo Clinic Disease Activity Index, and quality of life, when compared to mesalazine alone.Considering the preclinical studies, one of the contributions is the work of T. Mao et al., who explored the mechanism of Qingchang Wenzhong Decoction (QCWZD), preparation derived from eight plants, in UC in rats models. The authors showed that QCWZD administration significantly alleviated colitis-associated inflammation, upregulating serum macrophage-stimulating protein (MSP) and receptor d'origine nantais (RON) expression in the colon, reduced the pAkt  levels, promoted zona occluden 1 (ZO-1) expression, and depressed claudin-2 expression. Of this mode, it was possible to conclude that QCWZD appears to attenuate DSS-induced UC in rats by upregulating the MSP/RON signaling pathway, contributing to understanding of QCWZD benefits in UC.Still considering the preclinical studies, Y. Yang et al. described the anti-inflammatory effects and the underlying mechanisms of GCZX-pill, Chinese herbal formula composed of six herbs, on trinitrobenzene sulfonic acid- (TNBS-) induced UC in rats. The results demonstrated that the GCZX-pill can attenuate colitis in rats and the anti-inflammatory effect of the GCZX-pill may be related to the reduction of enterochromaffin colonic cells hyperplasia and serotonin availability.α and insulin pathway.The third preclinical study was done by H. Zhang et al., who tested the effects of two Chinese herbal formulations, Erchen decoction (ECD) and Linguizhugan decoction (LGZGD), on insulin resistance in rats. The results indicated that ECD and LGZGD have protective effects against high-fat diet-induced liver insulin resistance and their underlying mechanisms involve the TNF- Periplaneta americana) combined with mesalamine for the ulcerative colitis (UC) patients and in addition evaluated the grade of the quality of evidence by using the GRADE  approach. With this revision, the authors concluded that although Kangfuxinye enema seems to be effective and safe for treating UC patients in this systematic review, Kangfuxinye enema combined with mesalamine was weakly recommended due to very low to moderate quality of available evidence by the GRADE approach.In the review articles, P. Ren et al. reported a comprehensive review concerning the efficacy and safety of Kangfuxinye enema , composed of four ingredients: the roots ofFinally, L. M. da Silva et al. did a review concerning the potential role of propolis in the treatment and prevention of gastrointestinal disorders. They reported and critiqued the studies showing the beneficial effects of propolis and its active compounds in the treatment of gastrointestinal diseases; however, they concluded that only few clinical trials have been conducted to prove their effectiveness and safety against human ulcers and their associated pathologies.Thus, this special issue included different investigations related to the efficacy of herbal medicines in the treatment of inflammatory and ulcerative gastrointestinal disorders, based on clinical and preclinical studies as well as the revision of the literature related to the objective of this special issue.Sérgio Faloni de AndradeLuisa Mota da SilvaShahram GolbabapourSteve Harakeh


Metabolomics is used in systems biology to enhance the understanding of complex disease processes, such as cancer. Head and neck cancer (HNC) is an epithelial malignancy that arises in the upper aerodigestive tract and affects more than half a million people worldwide each year. Recently, significant effort has focused on integrating multiple “omics” technologies for oncological research. In particular, research has been focused on identifying tumor-specific metabolite profiles using different sample types  and a variety of metabolomic platforms and technologies. With our current understanding of molecular abnormalities of HNC, the addition of metabolomic studies will enhance our knowledge of the pathogenesis of this disease and potentially aid in the development of novel strategies to prevent and treat HNC. In this review, we summarize the proposed hypotheses and conclusions from publications that reported findings on the metabolomics of HNC. In addition, we address the potential influence of host-microbe metabolomics in cancer. From a systems biology perspective, the integrative use of genomics, transcriptomics and proteomics will be extremely important for future translational metabolomic-based research discoveries. The incidence of head and neck cancer (HNC) exceeds half a million cases annually worldwide and accounts for approximately 3% of adult malignancies . In addition to the host-metabolomic profiles, we discuss the potential relationship and influence of the microbial metabolome in cancers. By coupling metabolomics data with other omics data, we can achieve a greater understanding of complex cancer processes and derive new information that may help to better target aggressive and malignant cancer types, such as HNC.A broad array of biological fluids, such as saliva, blood and urine have been used in metabolomic-based studies , but not uric acid (antioxidant), was significantly increased in patients with oral and pharyngeal SCC compared to healthy controls  displayed similar metabolomic profiles between one another, suggesting that HNSCC tissues share similar metabolic activity during malignant transformation , like HNC, is associated with risk factors that include diet and lifestyle  and co-existing microbiota Figure . In addiJS wrote the manuscript, put the figure and table together, and edited the manuscript. PK, JF, and AR edited the manuscript, edited the figure and table, and edited the manuscript. JF, AR, and YK conceived the topic for the mini review, assisted with the manuscript writing, assisted with the figure and table and edited the manuscript.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.


To review the influence of cleats-surface interaction on the performance and risk of injury in soccer athletes.  Systematic review.  Scopus, Web of science, PubMed, and B-on.  Full experimental and original papers, written in English that studied the influence of soccer cleats on sports performance and injury risk in artificial or natural grass.  Twenty-three articles were included in this review: nine related to performance and fourteen to injury risk. On artificial grass, the soft ground model on dry and wet conditions and the turf model in wet conditions are related to worse performance. Compared to rounded studs, bladed ones improve performance during changes of directions in both natural and synthetic grass. Cleat models presenting better traction on the stance leg improve ball velocity while those presenting a homogeneous pressure across the foot promote better kicking accuracy. Bladed studs can be considered less secure by increasing plantar pressure on lateral border. The turf model decrease peak plantar pressure compared to other studded models. soft ground model provides lower performance especially on artificial grass, while the turf model provides a high protective effect in both fields. The  Soccer is the most practiced and most popular sport worldwide . This spSeveral adaptations have been introduced in soccer along the years. The increasing use of artificial grass field , 5 and cturf (TF), artificial grass (AG), hard ground (HG), firm ground (FG), and soft ground (SG) [HG model for hard, natural, or dirt soccer fields. The FG model is indicated for natural grass in good conditions, while the SG to very muddy or wet natural fields. The classification of these models depends on the size, number, distribution, and type of studs. Thus, the first model (TF) presents the highest number of studs, but also the smaller ones. The other models present a progressive decrease in the number of studs and an increase in its size [The cleats have been considered the most important soccer tool, playing a crucial role in the athletes' performance , 10. Itsund (SG) , 16. Accits size , and forits size , 21. TheWith the increasing number of models available on the market, it becomes important to review the influence of cleat-surface interaction on athletes' performance and injury risk to identify the cleat that better responds to the need of increased performance and reduced injury risk.Which model of soccer cleats promotes a better performance in artificial and natural grass?Which model of soccer decreases the risk of injury in artificial and natural grass?The two main research questions in this study were as follows:The literature search included only the period from 2000 until 2016 on the following databases: Scopus, Web of science, PubMed, and B-on .The following search term combinations were used in all databases: soccer shoes; soccer boots; soccer cleats; soccer studs; soccer footwear; shoe-surface interface, and shoe-surface interaction. The search terms were limited to titles and abstracts published in academic journals. The reference lists of all studies were also scanned to identify other potential eligible articles. The study was conducted using the systematic review method proposed by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis—PRISMA . The artThe studies included in this systematic review were evaluated using a quality index proposed by Downs and Black  and the Data from the included studies was extracted by one reviewer and then checked by a second reviewer using a data extraction table which identified the following: author identification, year of publication, sample, ground and footwear conditions, methods and instruments, variables assessed, and main conclusions regarding the shoe-surface interaction on performance and injury risk.The search strategy revealed 213 articles. After an initial review, 84 were rejected as copies of the same paper and 95 were excluded as they were clearly unrelated with the main theme or because the sport studied was not soccer. All remaining articles were then reviewed by two independent reviewers. Consensus was reached, and a total of 23 were included as shown in Most of the studies assessed the traction imposed by different cleat models during sprint or change of direction maneuvers , 18, 25.The findings obtained in artificial grass showed that generally SG models decrease performance , 15; howThe studies that have addressed specific cleat characteristics demonstrated the following: (i) bladed studs improved performance compared with the elliptical ones , 28;  the use of cleats without studs (similar to TF model) when compared to cleats with studs could decrease the incidence of calcaneal apophysitis  and (ii)Once again, in natural grass fields, the TF model revealed as the best choice when compared to SG model to prevent injuries related to repetitive impacts . Lastly,Since 2008, Sterzing and coworkers evaluated various cleat models in two different fields  during different functional tasks like slalom and short straight line acceleration , 18, 25,In general, the model defined by the manufacturers as indicated for artificial grass has been demonstrated to favor performance in this kind of field compared to design model for natural grass (SG) and this is perceived by athletes , 15. TheStudies performed on natural grass revealed that despite not being perceived by the athletes, bladed studs are associated to increased performance compared to the elliptical ones in dry or ice and snow conditions . In thisOther performance tests regarding kicking tasks revealed that cleats that promote a good traction on the support leg appear to enhance the speed of the shot, while outsole stiffness does not contribute to increased kick velocity . The staArtificial grass features numerous characteristics, such as infill particle size, level of compaction, and fiber type; however, only few characteristics have been considered in most of the papers -13. SomeHG, and FG models in terms of performance [Despite the high ability of athletes to compensate the different mechanical traction imposed by different cleats during a dynamic task, the findings obtained by the previously mentioned studies  demonstrformance , 15, 18,formance . Howeverformance . None offormance . It shouformance , 27. GivVarious cleat models have been evaluated since 2002 in both natural and artificial fields during different functional tasks . Unlike in the previous research question, this interaction was investigated not only in male athletes , 30–37 bFor a better understanding, the results will be discussed considering the variables/instruments used to measure the injury risk of the different cleat models. First of all, it is important to highlight that most of authors used more than one instrument, combining, frequently, the use of motion cameras systems and force platforms –37. WhetPlantar pressure distribution and neuromuscular variables could give important insights regarding the risk of injury. However, few studies have addressed these variables. The TF model appears to be the only cleat that decreases the force and pressure beneath the metatarsal heads and, for that reason, could possibly minimize metatarsal injury risk . The blaSome authors encouraged the study of cleat-surface interaction using sporting gestures performed in place of practice/game ; howeverLike in performance, the kind of grass also influences the risk of injury. When peak torque and the rotational stiffness was assessed by a mechanical instrument in different fields, the lowest peak torque was related to natural fields compared to four different artificial fields . In addiIn the future, it will be important to assess functional tasks and variables related to specific injuries in populations with higher risk, such as athletes with chronic ankle instability. Future studies involving jump strategies associated with different clinical conditions, like chronical ankle instability, are required, since the landing mechanism is a moment where a lot of injuries happen . If possGlobally, the mentioned studies highlight the TF as a protective model and the SG as a potentially harmful model for repetitive impact lesions, mainly in artificial fields. This is valid both in young  and adulCleat-surface interaction is an important and current topic, not only because it interferes with one of the soccer players' concerns (performance) but also with the injury risk and absenteeism from sport practice. Literature reveals a decreased sports performance with the SG model, a protective feature of the TF model cleat, and an increased risk of injury in the artificial grass. However, the health promotion literature continues to be slightly specific. The study of this interaction in healthy subjects under fatigue is essential, but very little has been studied so far. Also, because soccer player present a high prevalence of ankle sprains, the cleat-surface interaction should be evaluated in athletes with increased risk of ankle sprain, such those with chronic ankle instability. Finally, another important factor is the introduction of dynamic and unpredictable test protocols for the detection of differences in the cleat-surface interaction. The study of this interaction in the injury risk is an exciting field, but there is still much to explore. The results obtained about this topic will help sports health professionals to work more efficiently on injury prevention with the sports community.


Pressure-driven membrane-based technologies represent a valid approach to reduce the environmental pollution of several agro-food by-products. Recently, in relation to the major interest for natural compounds with biological activities, their use has been also addressed to the recovery, separation and fractionation of phenolic compounds from such by-products. In particular, tight ultrafiltration (UF) and nanolfiltration (NF) membranes have been recognized for their capability to recover phenolic compounds from several types of agro-food by-products. The separation capability of these membranes, as well as their productivity, depends on multiple factors such as membrane material, molecular weight cut-off (MWCO) and operating conditions . This paper aims at providing a critical overview of the influence of these parameters on the recovery of phenolic compounds from agro-food by-products by using tight UF and NF membranes. The literature data are analyzed and discussed in relation to separation processes, molecule properties, membrane characteristics and other phenomena occurring in the process. Current extraction methodologies of phenolic compounds from raw materials are also introduced in order to drive the implementation of integrated systems for the production of actractive phenolic formulations of potential interest as food antioxidants. Today, the recovery of biologically active compounds from natural sources has attracted great attention due to their potential uses such as ingredients in foodstuff, pharmaceutics, and cosmetic formulations. Among these compounds, polyphenols (PPs), secondary metabolites ubiquitously distributed in all higher plants, have been recently the most searched ones . PPs repl-phenylalanine or tyrosine. Typically, all these compounds present the basic chemical structure based on cinnamic acids (C6–C3) and benzoic acids (C6–C1) , which are derived from  (C6–C1) .Over the course of the last decades, phenolic compounds have been deeply studied for their great protective activities as antioxidants, free radical scavengers, and metal chelators, as well as to the ability to reduce and inhibit different types of enzymes  ,6. They Phenolic compounds have been identified in a wide class of plant-derived foods such as fruits (berries and berry products), seeds, cereals, leaves, and vegetables, and the list is constantly growing . The reqIn this framework, the aim of this paper is to provide an overview of the conventional extraction and separation methods for phenolic-based compounds from different agro-food by-products, highlighting the role of tight ultrafiltration (UF) and nanofiltration (NF). The effect of key parameters on the performance of these processes in terms of productivity and selectivity towards target compounds are analyzed and discussed. Current extraction methodologies and pre-treatment systems before separation, fraction and concentration of target compounds are also analyzed in order to provide a wide outlook on the potential of tight UF and NF membranes in integrated systems for the production of functional ingredients.Agro-residues produced during the handling and processing of fruits, vegetables and forest resources are characterized by a complex composition of phytochemicals such as vitamins, tocopherols, PPs, and carotenoids, along with complex carbohydrates and fiber which have been been associated with the alleged health-promoting effects of fruits and vegetables consumption. Therefore, their extraction from residues and agro-industrial by-products, as an alternative to the synthetic substances commonly used in the food, pharmaceutical, and cosmetic industries, has been strongly encouraged .The development of adequate methods for the recovery of phenolic compounds from their original sources is crucial and can be accomplished through several steps . The proExtraction is the first and crucial step and plays an essential role in the final characteristics of the product. The traditional process to extract PPs from by-products is the conventional extraction by solvent (Soxhlet extraction); however, drawback of leaving trace amounts of solvents or causing thermal degradation has driven to find new technologies to avoid that . In thisIndependent of the selected type of extraction, there are some common objectives, including selectivity and efficiency in the release of the target phytochemicals and a reproducible method regarding variations in the sample matrix . SeveralMAE is one of the most important and attractive non-conventional techniques to assist the extraction of phytochemicals from agro-industrial residues or by-products ,26,27. SUAE is considered a key technology in achieving the objective of a sustainable “green” extraction. It has been widely reported to have a significant effect on the rate of various processes in the chemical and food industry .The ultrasound extraction mechanism involves two main types of physical phenomena: (i) diffusion across the cell wall, and (ii) the rinsing of cell contents after breaking the walls increasing mass transfer ,31,32,33Several factors such as sonication time, temperature, and solvent selection as well as wave frequency and ultrasonic wave distribution should be controlled in order to maximize the extraction yield . Based oSince its beginning in 1964, SCFE has attracted wide scientific interest because of its suitability for extraction and purification of compounds having low volatility or those which are susceptible to thermal degradation . SupercrSome applications for recovery of phytochemicals from food wastes have been reported in the literature, e.g., grape peel , tomato Two to three decades ago, applications of pulsed electric fields (PEF) for treatment of liquid and solid foods became more and more popular . The bioEven though there are differences between the technologies mentioned above regarding extraction yield, simplicity of operation, investment cost, operation time, safety, and degree of automation, all of them have comparative advantages in comparison to the traditional solvent extraction. Independent of the technology selected for the extraction, subsequent steps of separation, purification, and final concentration are needed. The next section will introduce conventional and non-conventional separation methodologies.The obtained extract, whatever the extraction methods used, have not only bioactive phenolics and PPSs but also others components such as mono- and poly-saccharides, as well as the solvent used for the extraction. Therefore, a separation step is crucial not only for removing the solvent but also to purify bioactive compounds.Traditional methods of polyphenol purification comprises coagulation and precipitation of impurities , adsorption of PPs on resins, elution of purified PPs, and their concentration by solvent evaporation.Adsorption, ion exchange, column chromatography, and affinity chromatography can be grouped as recovery techniques in which the removed compound or solute establishes an equilibrium between sites on a solid phase material and the solution. In adsorption, the removed species is bonded to the solid phase material by polarity or weak chemical bonds. Ion exchange recovers material by the interchange of ions between the liquid and solid phases. Column chromatography may use adsorptive, ion exchange or molecular sieve materials to separate solutes which are first loaded onto a column of the separation material and then eluted in such a manner that the individual solutes are collected in separate fractions. In affinity chromatography, the removed species is bound with a high level of selectivity to ligands covalently attached to a solid matrix .These operations account for a significant part of the total costs of polyphenol production. Additionally, some of them are based on a phase change which implies the application of temperature that can produce a decrease in the healthy activities of phytochemicals.In this regard, pressure-driven membrane processes such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) are consolidated systems in various productive sectors, since the separation process is athermal and does not involve phase changes or chemical agents ; additioMembrane-based technologies, such as MF, UF and NF, are physical separation processes allowing the separation of different compounds from a feed solution under a hydrostatic pressure difference applied between the two sides of a permselective barrier. As a result, the feed solution is divided into a permeate fraction containing all components that have permeated the membrane and a retentate fraction containing all compounds rejected by the membrane, within some of the solvent ,46. The MF membranes have large pore sizes ranging from 100 to 10,000 nm (separating particles), while UF membranes have pore sizes between 2 and 100 nm which are able to retain molecules with molecular weights ranging from 350,000 to 1000 Da. NF membranes are characterized by narrow pore sizes from 0.5 to 2 nm, retaining micromolecules with molecular weights from 120 to 1000 Da .A schematic representation of MF, UF and NF processes is illustrated in Wide UF membranes, with MWCO ranging between 50 and 100 kDa, can fundamentally be used to recover different types of macromolecules . UF membranes from 4 to 30 kDa are effective to concentrate high molecular weight components , while tight UF membranes, from 1 to 3 kDa, are highly effective to concentrate low molecular weight compounds ; indeed, these membranes are in the molecular limit of the NF process . Low nomThe general flow-sheet for the recovery, purification and concentration of phenolic compounds from vegetable sources through a combination of membrane operations is illustrated in In principle, separation processes using tight UF and NF membranes are able to separate specific compounds through a sieving mechanism based on the MWCO; however, the membrane’s MWCO is not the only criterion that has to be taken into account. For instance, the asymmetric manufacture of membrane pores does not always reflect a narrow MWCO range; in addition, some other phenomena  also contribute to the phenolic retention ,47,48. IAgro-food wastewaters contain considerable amounts of high molecular weight solutes in the shape of suspended solids and colloidal particles identified as detrimental from a bioactivity perspective. Physical and physico-chemical processes  are used as primary separation (as pre-treatment) to remove suspended solids or other impurities. Because of this purpose, the use of UF and MF processes has been often introduced in integrated systems for recovery of phytochemicals from agro-industrial by-products as preliminary step, in alternative to the use of conventional systems based on the use of adsorbents and filter aids, before a fractionation step performed by using tight UF and/or NF membranes . The genThe olive oil extraction is a water-intensive process that generates a huge quantity of polluted effluents commonly referred to as olive mill wastewaters (OMWs). These effluents are characterized by high concentrations of organic compounds, including organic acids, sugars, tannins, pectins and phenolic substances that make them phytotoxic and inhibit bacterial activity. The typical composition of OMWs is reported in Suspended solids of raw OMWs can be removed by centrifugation. The following treatment by UF allows a complete separation of fats, completely rejected by the membrane, from salts, sugars and polyphenols, contained in the permeate. A chemical oxygen demand (COD) reduction of about 90% is reached through the combination of both processes . SimilarCassano et al.  evaluateIn a previous study , the preAn innovative process design for PPs encapsulation from OMWs was proposed by Bazzarelli et al.  through According to Arvaniti et al. , UF provOlea europaea L. tissues (leaves and pitted olive pulp) and Cynara scolymus L. by-products (leaves and stems) through an environmentally friendly process based on a water extraction and membrane separation technology [Standardized fractions enriched in phenolic compounds were obtained from chnology . In the Cynara scolymus L.) processing industry generates large amounts of agricultural solid wastes  and wastewaters. These wastes are considered a rich source of bioactive phenolic compounds (with mono- and di-caffeoylquinic acids being the major components) and also inulin, fibres and minerals [The artichoke , insoluble carbohydrates, fibers, organic acids, essential oils, flavonoids and carotenoids . The typThe UF process separates the flow from the press liquor into a permeate with a total soluble solids content and an acidity level similar to that of the feed solution and a retentate containing suspended solids such as proteins and fibers and high molecular weight carbohydrates such as pectins associated with cloud . MF polyCitrus Bergamia Risso) is a natural citrus fruit widely exploited for the production of essential oil employed in pharmaceutical, cosmetic or food industry. The juice has not found a real use in the food industry due to its bitter taste and it is considered just a secondary or even waste of the essential oil extraction; however, it has been recognized as a source of bioactive compounds, including flavonoids with statin-like properties (named brutieridin and melitidin) able to reduce cholesterol levels in blood [Bergamot : in this case the retention of phenolic compounds decreased by increasing the TMP from 2 to 8 bar .In general, higher temperatures will lead to higher flux in both the pressure-controlled region  and in the mass transfer-controlled region . The effect produced by increasing temperature is related to a decrease in the viscosity of the feed, which imply lower pumping energy and horsepower required . In any The retention of a cross-linked aromatic polyamide (PA) membrane with a MWCO of 150–300 Da  towards phenolic compounds of artichoke brine at different temperatures showed no significant difference among the investigated compounds. Therefore, a higher flux can be obtained by increasing the operating temperature without affecting the final composition of the concentrated product .An increase in feed flow rate enhances mass transfer coefficient, reduces concentration polarization and accumulation of solutes on the membrane surface . In this−1) and well below the one corresponding to the highest velocity (0.87 ms−1).Giacobbo et al.  evaluateThe use of air sparging via the injection of gas bubbles into the feed stream, applied successfully to the enhancement of UF and MF processes, has also been investigated in the treatment of molasses wastewater by NF . Both coThe concentration of phenolic compounds in the retentate fraction increases by increasing the volume reduction factor (VRF) of the filtration process. Cassano et al.  observedThe separation mechanism involved in UF and NF processes seems to be simple in theory because it is based on a “sieving effect” which allows compounds to be retained on the basis of their molecular weight (MW). However, in practice, the MWCO of the membrane is not an absolute barrier and the solute rejection/transport through the membranes is also influenced by interactions between the membrane itself and the compound being filtered. Another aspect is that the manufacture of the membrane creates asymmetric pores that do not always reflect the respective range of the MWCO . A reducThe effect of MWCO of tight UF and NF membranes on the purification of PPs from other biologically active compounds has been studied by different authors. For instance, Conidi and Cassano  evaluateSimilarly, four spiral wound membranes of different materials  and MWCOs  were employed in the separation of phenolic compounds of orange press liquor from sugar compounds [2 membranes, 750 and 450 Da from Inopor) in order to evaluate the effect of the MWCO on the rejection by the membranes towards sugars, organic acids and PPs. The effect of MWCO on the rejection of sugars and flavonoids is illustrated in In a previous study, the same authors tested different UF and NF membranes and their performance in the separation and concentration of PPs from ultrafiltered bergamot juice . In partExperimental results indicated that the Etna 01 PP membrane preserved flavonoids and sugars in the permeate fraction in agreement with the MWCO of this membrane (1000 Da) and the MW of the investigated compounds which is in the range 180–610 Da. The NF 750 Da membrane showed a rejection towards flavonoids in the range of 43–62% and a rejection towards PPs of 44%. Therefore, phenolic fractions with molecular weight greater than 750 Da were retained on the retentate side of the membrane. Besides, flavonoids identified in the juice , with molecular weights from 550 to 610 Da, were also partially retained by the membrane due to fouling phenomena. The observed rejection towards sugars was about 30%. The rejection of the NF 450 Da membrane towards flavonoids was in the range of 91–99%. Therefore, flavonoids were retained on the retentate side of the membrane, in agreement with the MW of the analyzed flavonoids. The rejection of this membrane towards sugars was 48% indicating a better performance in terms of separation between sugars and flavonoids in the clarified juice.Giacobbo et al.  investigFor PES membranes (NP030 and NP010) the rejection towards phenolic compounds of artichoke brines  is a function of the MWCO; an increased rejection for all these compounds was observed for the NP030 membrane which is characterized by a lower MWCO .Sideritis ssp. L. At this purpose, three flat-sheet organic solvent resistant NF membranes , with MWCO in the range of 200–500 Da, were tested. Experimental results indicated that all membranes showed high rejection towards flavonoids (from 97% up to 99%) as confirmed by the low concentration observed in the permeate. The best purification of flavonoids from low molecular weight PPs was possible with the membrane having MWCO higher than 400 Da, while the 300 Da membrane allowed a complete concentration of these compounds (up 3–4 times with respect to the starting solution).Tylkowski et al.  studied Eucalyptus globulus bark. Among the investigated membranes JW , PLEAIDE  and 90801  were selected for the concentration process of bark extract. The rejection values for total phenolic compounds increased in the order JW, PLEAIDE, 90801, following the trend of the MWCO. Lower rejections were found for total carbohydrates indicating the suitability of the UF and NF processes for the removal of sugar moieties in the permeate stream.Pinto et al.  evaluateRecently, different tight UF and NF membranes in flat-sheet configurations, with MWCO ranging from 1000 to 4000 Da were tested to purify PPs from sugars in clarified pomegranate juice . AccordiThe selection of the membrane materials is extremely important for assuring good membrane stability in the presence of the main solvent and a low adsorption of solutes. In order to avoid solute adsorption and fouling, the membrane should exhibit low affinity towards the solutes. On the other hand, a high affinity towards the membrane, ensures high fluxes of solvent.An interaction between the membrane structure and the MWCO with the polarity of smaller solutes has been also reported. For instance, during UF of winery sludge extracts with membranes of MWCO of 100 kDa and 20 kDa , phenolic compounds and sugars were concentrated in the retentate side (rejection in the range 50–99%) despite their low corresponding molecular weight (<1000 Da) . The higBenitez et al.  reportedVitis labrusca L.) juice [In a different approach, PVDF UF flat sheet membranes with different MWCO (in the range of 10–1000 kDa) were investigated for the fractionation of PPs on the basis of their MW from Concord grape (.) juice . The selAccording to the results obtained by Russo  in the fRegenerated cellulose UF membranes with MWCO of 5 and 10 kDa exhibited lower retention of phenolic compounds in the treatment of OMWs when compared with PES membranes of 4 and 10 kDa . This beSteric exclusion and hydrophobic attraction have been proposed as the main interactions occurring between phenolic compounds and semiaromatic piperazine-based PA membranes . The hydCaryocar brasiliense Camb.) fruit. On the other hand, the retention for alcoholic extracts were much lower (of the order of 15%). This behavior was attributed to the predominant hydration by water molecules in water systems which reduces the effective membrane pore size due to hydration/solvation of pore walls [This membrane exhibited high retentions (about 97%) towards phenolic compounds of aqueous extracts of pequi (re walls .The high rejection of NF polymeric membranes towards anthocyanins of citrus press liquor see  was attrFruit and vegetable processing residues are considered highly polluting wastes because of their high organic load and phytotoxic and antibacterial phenolic substances resistant to biological degradation. On the other hand, intensive research in the field of agro-food waste management suggests that these effluents should be regarded as a useful resource for the recovery of fine chemicals and for different biotechnological applications such as the production of important metabolites. In particular, agro-industrial by-products can be considered a promising alternative to synthetic antioxidants used in food, cosmetics and pharmacy since they are an inexpensive source of valuable compounds, mainly polyphenols which are known for their antioxidant properties.Pressure-driven membrane operations are well-known established technologies for the treatment of high strength wastewaters aimed at the production of purified water for recycle or reuse and the recovery of valuable compounds.The use of tight ultrafiltration and nanofiltration membranes has been reviewed in the light of their growing use for the separation and purification of phenolic compounds from agro-food by-products and extracts. Tailor made processes for specific by-products can be identified through an appropriated selection of membrane typology as well as optimization of operating and fluid-dynamic conditions which are key parameters influencing both productivity and selectivity towards target compounds.The combination of tight UF and NF membranes with conventional extraction systems and/or membrane pre-treatment of raw agro-food wastewaters offer new opportunities for the formulation of nutraceutical products while reducing the environmental pollution of these effluents.


Verongida and Dictyoceratida. This family of chemical compounds is composed of a high number of metabolites, including puupehenone, the most characteristic compound of the family. Chemical synthesis of puupehenone has been reached by different routes, and the special chemical reactivity of this molecule has allowed the synthesis of many puupehenone-derived compounds. The biological activities of puupehenones are very diverse, including antiangiogenic, antitumoral, antioxidant, antimicrobial, immunomodulatory and antiatherosclerotic effects. Despite the very important roles described for puupehenones concerning different pathologies, the exact mechanism of action of these compounds and the putative therapeutic effects in vivo remain to be elucidated. This review offers an updated and global view about the biology of puupehenones and their therapeutic possibilities in human diseases such as cancer.Marine sponges represent a vast source of metabolites with very interesting potential biomedical applications. Puupehenones are sesquiterpene quinones isolated from sponges of the orders  Porifera) are sessile and filter-feeder multicellular organisms that lack body symmetry. The soft body of the majority of sponges and the incapacity of movement make these organisms a perfect target for predators ; the adaptive strategy of sponges to such threats is the synthesis of chemical compounds that have a defensive role to deter predators Aspergillupehenol . A potena krusei . The gropehenone .Mycobacterium tuberculosis, respectively MART-126-35, a modified HLA-A2-associated decapeptide identified to function as an epitope for melanoma-reactive cytotoxic T lymphocytes [Using the mixed lymphocyte reaction (MLR) test , 15-oxopphocytes . In spitRecently, a potential role of puupehenones targeting atherosclerotic disease has been reported . AtherosAlthough the number of reports found in the literature about puupehenones is not very large, the high diversity of compounds belonging to this family and the versatile and interesting biological activities reported for them  make puuFrom a chemical point of view, the unique characteristics of puupehenones’ structure provide an excellent scaffold for the rationale design of therapeutic agents that could improve the treatment of current resistance-associated human diseases, such as cancer. This feature has been indeed put into use for the search of new antiangiogenic and kinase inhibitor compounds .Biological activities detected for puupehenones are very diverse, and their antitumoral role represents one of the most interesting effects in biomedical research. There are, however, no reports about the systemic effect of these compounds in in vivo cancer animal models, which could improve the knowledge of the antitumoral potential of puupehenones. Taking into account the antiangiogenic activity of some puupehenones , namely,−/−ApoE) would shed some light on this promising therapeutic application of puupehenones.Apart from their antitumoral role, the inhibitory activity of puupehenones on lipoxygeneses deserves the attention of future investigations ,37. In aAnother important finding about puupehenones is their potential in the modulation of immune responses in T cells in vitro. This activity has been reported ,46, but In summary, the sponge-isolated compounds puupehenones and their synthetic derivatives represent an open field of investigation for biomedical and pharmaceutical research, and deserve the close attention of the scientific community. The lack of in vivo data about the different effects of puupehenones in several diseases could be the principal goal of future research projects on this issue, since this information could shed some light on the putative use of puupehenones as therapeutic agents.


Optical coherence tomography angiography (OCTA) based on mathematical processing of sequentially acquired structural OCT images has been applied widely in both retinal and choroidal research and may have advantages over traditional angiography. Images obtained by OCTA are rendered under the assumption that the only moving entity in the retina is blood flow. Optical phenomena and image processing algorithms may create imaging artefacts. Therefore, OCTA images require careful interpretation. This review discusses the dark signals seen in the choroidal vasculature on OCTA using multiple factor analysis. For accurate and comprehensive interpretation of the choroidal vasculature, we recommend simultaneous consideration of the laser light penetration depth and masking effect of retinal pigment epithelium, the orientation of vessels in relation to the scanning lasers and blood flow, the range of regional detectable velocity of blood flow, atrophic tissues in the periphery, and absorption of superior vessels on the scanning laser. Optical coherence tomography (OCT), including spectral-domain OCT (SD-OCT) and swept-source OCT (SS-OCT), can yield depth-resolved evaluation of reflectance data, together with a volume of three-dimensional information. Using a Fourier transform, the reflections from various depths are frequency-encoded simultaneously . SS-OCT Nevertheless, OCTA has some advantages and drawbacks when compared with standard angiography. For example, OCTA is unable to visualise accumulation of dye, such as leakage, pooling, and staining, in tissue during standard angiography. Moreover, specific artefacts related to scan acquisition and the physics of optical reconstruction of vascular tissue occur in OCTA . HoweverOCTA has been reported to produce artefacts and requires careful interpretation, because of the inherent complexity of SD-OCT and SS-OCT . LimitinIt is important to note that there is currently no standard way of evaluating OCTA, and new clinical endpoints need to be established by large studies. In particular, the understanding and interpretation of various signals in the choroidal vasculature on OCTA remains controversial. The imaging mechanism and artefacts mentioned above contribute to the demonstration of blood vessels to some extent. This review investigates and summarises the factors contributing to the dark signals seen in the choroidal vasculature that should be considered when interpreting the results of OCTAImaging of the choroid using SD-OCT or SS-OCT is challenging, because the light is scattered and attenuated by the dense choriocapillaris microvasculature and retinal pigment epithelium (RPE) . OCTA, aOCTA, based on structural OCT data, involves OCT signal amplitude, phase, or a combination of both . One of OCTA only assesses vascular flow within a limited range of dynamic velocity. The ability of OCTA to visualise blood flow is limited to a certain range of flow velocities  . The sloThe relationship between blood velocity in small and large vessels in the retinal tissue and those in the choroid tissue is just the opposite. For example, Bhutto et al. found that choroidal blood flow was higher than retinal blood flow . SimilarOCTA also cannot assess vascular permeability without fluorescein or indocyanine green, because leakage during angiography is a diffusion process, rather than a bulk flow phenomenon . The difPolypoidal choroidal vasculopathy (PCV) lesions provide another illustration of the range of regional detectable velocity, producing dark abnormal choroidal vessels in OCTA. Segmentation of the choriocapillaris layer in OCTA has revealed the branching vascular network as a hyperflow lesion and a polypoidal lesion as a round hyperflow structure surrounded by a hypointense halo in a few cases, but as a round hypoflow structure in most cases. In contrast with the branching vascular network, the round hypoflow appearance of the polyp probably reflects unusual blood flow inside a polypoidal lesion . ClearlyThe vascular network of the choriocapillaris includes both anatomical and functional choroidal lobules , which aLight passing through a blood vessel can be reflected, refracted, or absorbed. In OCTA, a signal is obtained by reflected light originating from moving blood cells . When inRecently, Bukowska et al. classified OCTA-related artefacts into motion, fringe washout, decorrelation projection, masking and unmasking, and stromal decorrelation signals ; dark siTherefore, focal absence of the choriocapillaris on OCTA may have variable interpretations, including true choriocapillaris atrophy with complete loss of vessels, reduced blood flow, or simply image artefact , caused Multiple factors are involved in the illustration of choroidal vascular signals in OCTA. In order to obtain an accurate and comprehensive interpretation of the choroidal vasculature in OCTA, we recommend simultaneous consideration of the penetration depth of the scanning laser and masking effect of RPE, the orientation of vessels compared with the scanning laser and the intensity of blood flow, the regional detectable velocity range of blood flow, peripheral atrophic tissues, and absorption of superior vessels on the scanning laser.


Several models of visual aesthetic perception have been proposed in recent years. Such models have drawn on investigations into the neural underpinnings of visual aesthetics, utilizing neurophysiological techniques and brain imaging techniques including functional magnetic resonance imaging, magnetoencephalography, and electroencephalography. The neural mechanisms underlying the aesthetic perception of the visual arts have been explained from the perspectives of neuropsychology, brain and cognitive science, informatics, and statistics. Although corresponding models have been constructed, the majority of these models contain elements that are difficult to be simulated or quantified using simple mathematical functions. In this review, we discuss the hypotheses, conceptions, and structures of six typical models for human aesthetic appreciation in the visual domain: the neuropsychological, information processing, mirror, quartet, and two hierarchical feed-forward layered models. Additionally, the neural foundation of aesthetic perception, appreciation, or judgement for each model is summarized. The development of a unified framework for the neurobiological mechanisms underlying the aesthetic perception of visual art and the validation of this framework via mathematical simulation is an interesting challenge in neuroaesthetics research. This review aims to provide information regarding the most promising proposals for bridging the gap between visual information processing and brain activity involved in aesthetic appreciation. The ability to appreciate the aesthetic qualities of natural and manmade items is one of the universal characteristics of humanity. Neuroaesthetics is the discipline of investigating how beauty activates aesthetic perception and appreciation. It is situated at the intersection of psychological aesthetics, neuroscience, and human evolution . The maiThe neural correlates of visual aesthetic perception have been comprehensively investigated using functional magnetic resonance imaging (fMRI), electroencephalographic (EEG) recording, and transcranial magnetic stimulation (TMS). Subsequently, models have been constructed to promote interdisciplinary understanding and communication among different disciplines involved in the study of the mind .Researchers in the fields of neuroscience, cognitive science, and information science are faced with two major challenges concerning neuroaesthetics. (1) Are there putative neural networks in our brain that are responsible for visual aesthetic appreciation and aesthetic judgement? (2) Where in the brain does neural activation associated with aesthetic responses to visual stimuli occur? Such questions must be answered in order to develop more precise mathematical models of visual aesthetic appreciation. The general framework for the neural underpinnings of visual aesthetics guided by visual neuroscience reveals the prospects for cognitive neuroscience in this field. This can be considered the current working model of how the neuroscience of visual aesthetics might be mapped .Significant research effort has been devoted to investigating the neural underpinnings of the aesthetic experience of visual art using functional neuroimaging. The primary aim of such research is to reveal which brain areas, neural circuits, and mechanisms are involved in aesthetic responses to visual art. Areas most commonly activated in aesthetic appreciation tasks include the orbitofrontal cortex (OFC), anterior insula , and anterior cingulate cortex (ACC) . AccordiVessel and colleagues discovered that regions in the medial prefrontal cortex, which is part of the default mode network (DMN), were positively activated during the aesthetic appreciation of visual art . FurtherOne of the primary goals of neuroaesthetics is to uncover the neural foundations of aesthetic perception . Less thTwo research groups showed that the content of the visual artwork affects aesthetic judgement and appreciation via fMRI experiments , 26. SucAs listed in Over the past decade, several neutrally based and neutrally inspired models of aesthetic perception have been proposed. Although the internal structures of the models differ, the aims are very similar.Chatterjee proposed a general framework for the neural underpinnings of visual aesthetics guided by visual neuroscience , 30. In The working model of Chatterjee's proposal is shown in This model has been supported by the work of Basole et al. . Visual The neuropsychological model draws its main internal structures from vision cognition research. To some extent, Chatterjee's model can be explained by Nadal and Pearce's theory . By combThe model proposed by Chatterjee is a “feed-forward” system involved in the processing of different attributes, providing a neurophysiological framework for visual aesthetics. However, if we aim to build a mathematical representation of the model proposed by Chatterjee, the functions of early/intermediate visual systems, visual attention, and representation must be translated into relevant aspects of computer vision, such as feature extraction and selection, target recognition, and scene classification.Leder et al. proposed an influential framework of aesthetic experiences and aesthetic judgement in their cognitive model of information processing , 8. ThisThe model constructed by Leder and colleagues considers much the same elements as Chatterjee's model, though the crucial feature of context has been added . This moWith the development of empirical aesthetics over the last ten years, this model gained appeal with researchers in cognitive and information fields. Originally, the model aimed to provide an integrated description of the psychological processes involved in the aesthetic appreciation of art; therefore, it can be seen as an attempt to determine the psychological mechanisms and the contextual conditions that enable people's engagement with artworks to be valuable, affectively absorbing, and individually and socially meaningful experiences . The modThe model included a sequence of processing stages within the perceiver, flanked by constituting conditions. It was designed as an information-processing box model that summarized a variety of findings related to the way perception, knowledge, familiarity, expertise, style, and content, among others, influence the aesthetic experience of art. The model comprises five main processing stages: perception, implicit memory integration, explicit classification, cognitive mastering and evaluation, and continuous emotional evaluation.Tinio proposed the mirror model of art to describe the interface between making and viewing art . AccordiThis model is very successful when artists appreciate their own works, as artists have a much deeper understanding of their work than anyone else because of their prior knowledge regarding its creation and the emotion expressed at the time .  FigureKoelsch and colleagues proposed an integrative and neurofunctional framework for human emotions that includes four core emotional systems from the perspective of neural motion processing : the effThe quartet theory is an auspicious starting point for shedding light on the multifaceted occurrence of affective experiences in relation to art and aesthetics . The theThis model is also the first to consider the regulatory and communication functions of language as integral elements in emotion processing . AlthougRedies proposed a unifying model of visual aesthetic experience that combines the formalist and contextual aspects of aesthetics . This dyThe neural mechanism responsive to beauty is activated in the visual brain regions, which predominantly proceeds the visual information in a bottom-up direction . In the Stimulus and context are the two main components of external information in The first real mathematical model to bridge the gap between low-level statistical features and aesthetic emotions aroused by visual textures was proposed by Thumfart and colleagues . Using tTo fully describe visual textures, 118 features are extracted, including three color features, 31 Gabor energy map features, 44 Fourier energy features, 10 neighborhood grey-tone difference matrix features, six Tamura features, and 88 grey-level cooccurrence features. Feature evaluation and selection decrease the model's complexity. In the original study, 27 pairs of intermediate aesthetic properties were selected, and six pairs of core aesthetic properties were assigned to three layers after psychological experiments. Two different approaches were used to develop the model. Supervised machine-learning methods automatically generate linear and nonlinear models when texture features and aesthetic properties are used as inputs and outputs, respectively. This model critically emphasizes the pathways in human perception that bridge the gap between low-level texture features and high-level aesthetic emotions triggered by those textures. Regression functions were used instead of classifiers to model human aesthetic perception of visual textures, and a continuous rating scale was employed to obtain reasonable data as output variables.The major contribution of Thumfart and colleagues concerns the development of white-box models that allow for the identification of the interactions between aesthetic properties and features at different levels of complexity . A strucSimilarly, Liu et al. built a hierarchical feed-forward three-layered model of aesthetic texture perception , 14. TheExcept for the six models mentioned above, some types of machine-learning models, such as deep learning, artificial neural network, and support vector machine, have been used for photograph aesthetical evaluation and prediction –62 AlthoIn the present review, we discussed six individual models and the corresponding neural foundations for aesthetic perception. Although the internal structures of the models are very different, the aims of these models are similar. The relative advantages of these models of aesthetic perception are listed in As listed in The models support explanation and understanding of the theories of cognitive neuroscience, brain science, mathematics, and information science. The model is both descriptive and experimental, with qualitative observations and quantitative tests of hypotheses from the aspects of neuroscience and psychology.The models are compact enough with simple internal structures. To some extent, the simplicity of the model is preferable to the prediction performance when limited samples are used for model building and test. How do we make the simplest model the correct one? The biological architecture of visual cortex has provided a reference to simplify the aesthetics perception model into the hierarchical feed-forward structure like deep learning convolution networks. In other words, the combination of the strengths of recent neuroscience and brain science, especially the research results of neural underpinnings of visual aesthetic experience by using functional neuroimaging technology, is helpful to build a structured cognitive model of aesthetics perception.The models can be converted into mathematical ones with some conventional solving methods. The models should be white-box ones and can be formulized with some simple functions. The inputs and outputs are quantitative variables that can be gotten from psychology experiments and information-processing method. The general knowledge of artificial intelligence can be integrated into the aesthetics perception model to control the complexity and minimize structural risk and bad extrapolation behavior.What would qualify a model of aesthetic perception to be acceptable? This question can be difficultly answered before a mathematical model of aesthetic perception that truly human-like experiencing, perceiving, and appreciating has been built. Specifically, we argue that the acceptable models should do the following.As mentioned in Aesthetic responses to beauty are not independent of the neural systems involved in sensory, perceptual, and cognitive processes. As suggested by Chatterjee and Vartanian, aesthetic experiences emerge from the interaction between neural systems involved in sensory-motor processes, emotion-valuation processes, and meaning-knowledge processes .The models proposed by Chatterjee , Leder aAll these efforts to understand the basis of aesthetic experience are not so that we can build up a mathematical model, but simply and hopefully to understand how this emerging property comes about. At best, the mathematics model could be a tool for exploration, not a constraint and lens through which to judge functional theories.