Aeromicrobium, Bradyrhizobium, and Candidatus Nitrososphaera were enriched and several methanogenic Euryarchaeota were depleted in the moderately degraded meadow soil and highly degraded sandy soil. Soil total potassium contents in soils with different degradation levels were significantly different, being the highest in meadow soil and lowest in swamp soil. The association network analysis showed that total potassium positively correlated with specific bacterial and archaeal taxa. Jiangella, Anaerolinea, Desulfobulbus, Geobacter, Flavobacterium, Methanobacterium and Methanosaeta were identified as the keystone genera in the networks. Soil degradation affected soil properties, and caused changes in the bacterial and archaeal community composition and the association patterns of community members. The changes could serve as early warning signals of soil degradation in alpine wetlands.Soil microbes provide important ecosystem services. Zoige Plateau wetland, the largest alpine peat wetland in the world, has suffered from serious degradation in the past 30 years. We studied the composition of the Zoige Plateau alpine wetland soil microbiota and relations among specific taxa using 16S rRNA amplicon sequencing combined with association network analysis. Compared to the pristine swamp soil, taxons DA101,  The alpine wetlands are more vulnerable to climate change than those in other regions2. The Zoige alpine wetland on the Qinghai-Tibetan Plateau is the highest and largest alpine wetland in the world. Zoige wetland plays important roles in maintaining water balance, carbon sequestration, and biodiversity preservation3. It covers an area of 1.2 × 104 km2, occupying about 0.1% of the total global peatland area4. In the past 40 years, numerous studies have focused on the degradation of Zoige wetland that has resulted from increasing temperature, anthropogenic perturbations, and overgrazing by cattle. The studies have shown significant impacts of these activities on the landscape, hydrology, biodiversity, and ecosystem degradation, including severe peat deterioration. The mean annual temperature has increased at a rate of 0.16 °C per decade in this area, resulting in the drying of the wetlands5. The wetland area in Zoige has decreased by approximately 30% from the 1970s to the 2000s due to the decline of water table6, resulting in a transition from pristine swamp soil to degraded meadow soil, and even aeolian sandy soil at severely deteriorated sites8. Deterioration has also changed the composition of plant communities from humidogenes and aquatics to mesophytes and xerophytes9, and resulted in the decomposition of soil organic matter, loss of humus and peat horizon, and decrease in nutrient content11.Despite the increased understanding of the important roles of wetlands in terrestrial ecosystems, severe land loss and degradation occur in the wetlands of China due to population growth, land reclamation projects and over-grazing13. At high taxonomic ranks, for example at phylum or class level, bacteria and archaea exhibit ecological coherence, and community composition may be valuable in predicting ecosystem functioning14. Based on nutritional requirements and growth rates, microbes can be classified as either copiotrophs or oligotrophs at the phylum level, and applying this classification may contribute to further understanding of microbial community dynamics in response to environmental interferences15. Alpine wetland degradation could directly alter the composition of specific bacterial and archaeal phyla. For example, Bacteroidetes and Flavobacterium were widely distributed in the pristine swamp soil in Zoige wetland, while Alphaproteobacteria were more dominant in the degraded sandy soil16. However, knowledge on the response of bacterial and archaeal taxa at low taxonomical level (such as genus or species) to the alpine wetland degradation remains limited. It is likely that the loss of humus due to wetland degradation would select for specific taxa that depend primarily on organic substrates, resulting in changes in microbial community composition and soil nutrient status18. Taxa that are affected by alpine wetland degradation should be associated with edaphic properties like soil organic carbon, which could then be used as valuable indicators of alpine wetland soil nutrient status and development16. Microbial communities in soil are complex, including many potentially interacting taxa, and a full exploration of these interactions is important to allow an integrated understanding of soil microbial community structure and the ecological rules that govern them19. Co-abundance network analyses can be carried out using data generated from high-throughput sequencing to provide information on the community composition and interactions within communities19. Furthermore, co-presence links reflect shared niches while exclusion links suggest niche segregation.Soil microbes are critical in biogeochemical processes and organic material decomposition, and quickly respond to environmental disturbancesKnowledge on the effects of wetland degradation on bacterial and archaeal communities is still scarce. To address this, we applied 16S rRNA gene amplicon sequencing to detect microbial community variation in microhabitats associated with the succession of degradation, and determined factors associated with variation. The effects of wetland degradation on specific bacterial and archaeal taxa and their associations with soil nutrients were analyzed by analyzing differences in abundant taxa and by co-abundance network analysis. Our purpose was to determine (1) the variation in bacterial and archaeal communities, (2) the specific taxa affected by wetland degradation in the three soils, and (3) the possible relationships between specific taxa and soil properties. We hypothesized that (i) the bacterial and archaeal communities in the pristine soil would significantly differ with those found in the degraded soil due to the inherent differences in nutritional conditions, (ii) that taxa related to carbon and nitrogen cycling would either be enriched/or depleted, and (iii) the specific taxa that were substantially changed would form distinct association patterns.−1) was highest in the meadow soil and lowest in swamp soil (Table P < 0.001) , Acidobacteria (12.3–19.7%), and Chloroflexi (10.8–19.7%) were the dominant phyla in all soil types. In the swamp soil, the relative abundance of Proteobacteria was highest, while that of Acidobacteria was lower than in the other soils. Chloroflexi was more abundant in the swamp and sandy soils than in the meadow , followed by Betaproteobacteria (26.9 to 29.4%), Alphaproteobacteria (16.5–22.6%), and Gammaproteobacteria (14.0–15.4%) . Moreover, the relative abundances of Myxococcaceae (P < 0.05) and Rhodocyclaceae were lowest in the meadow soil, while those of Syntrophobacteraceae and Rhodospirillaceae were lowest in the swamp soil  Fig. . Proteobdow Fig. . Within 4%) Fig. . The relnce Fig. . Compareoil Fig. .Table 1PEnriched taxa (e-taxa) and depleted taxa (d-taxa), representing taxa with relative abundances twice higher or lower (P = 0.05) in the swamp soil than in the meadow and sandy soils, were identified by differential abundance analysis. Using taxa counts from swamp soil as a control and an FDR-adjusted P < 0.1, eleven and 89 differentially abundant taxa were detected at the phylum and genus levels, respectively Fig. .Figure 2Euryarchaeota, WWE1, OP8 and GOUTA4 were enriched in the swamp soil when compared with the meadow soil , and the top five d-taxa were Syntrophus, Methanobacterium, Methanosarcina, Chloronema, and Methanosaeta  Fig. .Principal coordinate analysis (PCoA) with weighted and unweighted UniFrac distances clearly separated the swamp communities from the communities in degraded soils Fig. . WeighteActinobacteria, Bacteroidetes, Chloroflexi, Euryarchaeota and Proteobacteria showed higher degree centrality in the network, suggesting that these taxa are strongly associated with the other members of the community , Anaerolinea (phylum Chloroflexi), Desulfobulbus (Proteobacteria), Flavobacterium (Bacteroidetes), and Methanobacterium and Methanosaeta (phylum Euryarchaeota). The abundances of these taxa were significantly higher in the swamp soil than in the degraded soils  were detected according to association strength among the differentially abundant taxa Fig. . Module ils Fig. , Table 2, and M3 ils Fig. . The varils Fig. .Table 2APCoA result showed significant (p = 0.001) correlations between network modules and soil properties, with soil TK ranking highest Fig. . This wa20, the bacterial and archaeal community compositions in the three soils differed significantly, but all were dominated by the phyla Proteobacteria, Acidobacteria and Chloroflexi. Proteobacteria are prevalent in various ecosystems and involved in many biogeochemical processes21. As in Röskeet al.22, Proteobacterial communities were mainly composed of Deltaproteobacteria and Betaproteobacteria, both classified as copiotrophs stimulated by increased nutrients in the environment15, which could partially explain why these two groups were more abundant in the swamp soil with higher organic matter content. Acidobacteria include many oligotrophs24, and their relative abundance was higher in the degraded soils that contained less organic matter, thus possibly favoring these oligotrophs. Interestingly, Chloroflexi that are known to survive on plant residues and grow even under nutrient limitation26 were more abundant in the sandy soil which had less nutrients than the pristine swamp soil.We studied shifts in bacterial and archaeal community composition in three soil types associated with wetland degradation: pristine swamp soil, moderately degraded meadow soil and highly degraded sandy soil. As in previous studies based on denaturing gradient gel electrophoresis27. With the lowering of water table, some of the wetland plant species that are essential in swamp soil formation are being replaced by meadow vegetation28. Different vegetation types may release different types of root exudates: the exudates are significant sources of carbon, nitrogen and energy of the soil microbiota29. Different plant species also have diverse nutritional needs, promoting the development of particular soil microbiome depending on the growth substrate30. In our study, water content, organic carbon content, and the total and available nitrogen and phosphorus contents all decreased along with the wetland degradation, making them valuable indicators for evaluating wetland degradation. Soil total potassium content was found to be an important factor shaping the bacterial and archaeal communities. Similarly, Pereira et al.31 found that the bacterial diversity and community composition in the soil were highly affected by the total potassium content. Potassium is easily leached because of its mobility in soils, and thus directly affected by soil degradation.Understanding the environmental variables that shape soil microbial community structuring is one of the key goals of microbial ecology. Soil water content was previously found to be the major factor connected with Zoige wetland degradation, with significant impacts on the decrease of fungal community abundance and prokaryotic diversityEuryarchaeota is mainly distributed in anoxic environments, for example in wetlands, paddy soils and marine sediments, and is involved in greenhouse gas production32. In this study, as expected, the abundances of Euryarchaeota were significantly higher in the pristine soils than in the degraded soils. Previous studies indicated that Zoige wetland was one of the hotspots of methane emissions in the Qinghai-Tibetan plateau, harboring a unique methanogen community33. In contrast, there were hardly any methanogens in the meadow soil in Zoige wetland34, probably due to the decreased soil water table and content that had lead to less anaerobic conditions. Although we did not measure the oxygen content in the soils, soil water content in the degraded soils had decreased significantly and water table was lower. A change in water table and content could directly affect the oxic–anoxic interfaces, increase the thickness of the boreal peatland aerobic layer, and ultimately change the microbial community composition and abundances35. Moreover, low water tables affect soil organic carbon (SOC) by changing the vegetation cover and SOC decomposition rate which is positively correlated with the methanogenic archaea community36. At the genus level, the enrichment of Methanobacterium, Methanosarcina and Methanosaeta in the swamp soil indicate their potential roles as ‘keystone species’ in methanogenesis in this ecosystem.The microbial community structure in the pristine swamp soil differed from those in the meadow and sandy soils. Consistent with our hypothesis, more taxa were enriched in the swamp soil, indicating that wetland degradation decreased the abundance of these bacterial and archaeal taxa. Methanogenic 37. Species related to Syntrophobacteraceae generally constitute consortia with methanogenic Archaea to syntrophically convert propionate to methane, which is a typical metabolic process during anaerobic degradation. It is likely that the relative abundance of Syntrophobacteraceae affiliated species in this study would similarly vary with the Methanogenic Euryarchaeota in response to wetland degradation. However, phylogenetic analysis of the community showed that contrary to the decreased abundance of the methanogenic Euryarchaeota, the abundances of members of the Syntrophobacteraceae actually increased. Syntrophobacteraceae are extremely diverse in their nutritional transformation capabilities, with some members being able to use a wide variety of electron donors and carbon sources syntrophically or in pure cultures, and in the presence or absence of sulfate as electron acceptor38. This metabolic peculiarity confers these microorganisms with adaptability to changing environmental conditions, and may explain the increase of Syntrophobacter-related species in the degraded meadow and sandy microcosms.Syntrophy, defined as a long-term stable relation of organisms which can be either beneficial or unbeneficial, plays a key role in many anaerobic ecosystems, even in systems where metabolism is sustained by the reduction of electron acceptors such as sulphate or nitrogen oxides39. Aeromicrobium are lignocellulose decomposers and play important roles in organic matter turnover in soil40. Bradyrhizobium are beneficial for plant growth due to their nitrogen-fixing ability. Candidatus Nitrososphaera thrives in organic-rich habitats41. The enrichment of these taxa in the degraded meadow and sandy soils suggest their subtle differences in habitat adaption, which also contributes differently to the carbon and nitrogen cycling in this specific ecosystem.DA101 can occupy various ecological niches and perform oligotrophic life strategy in soil42. A node with high betweenness centrality value is in a core location in the network, and may affect other interactions in the community43. Keystone species with maximum betweenness centrality values are likely to serve as gatekeepers in ecosystem functions45. In our study, most archaeal keystone species in the networks were affiliated with Euryarchaeota that participate in wetland carbon cycling as discussed above, while most bacterial keystone species were from Actinobacteria, Proteobacteria and Bacteroidetes. Of all the keystone species detected in our study, Desulfobulbus are the only ones involved in the sulfur biogeochemical cycle, particularly in the reduction of sulfate to sulfide46. Geobacter are able to oxidize recalcitrant organic carbon47, and Flavobacterium are stimulated in organic matter rich environments48. The organic matter content in the swamp soil was higher than in the degraded soils, which may explain the significantly higher abundance of Flavobacterium in the swamp soil. Taken altogether, the keystone species may be pivotal determinants of the succession of bacterial and archaeal taxa during the wetland degradation.Network analysis provides understanding of potential interactions such as cooperation, competition and niche partitioning in bacterial and archaeal communities, and may identify keystone populationsProteobacteria, Acidobacteria, and Chloroflexi were the most abundant phyla. Soil total potassium strongly affected the shaping of bacterial and archaeal communities. Interpretation of the interaction networks in soil bacterial and archaeal community may open new avenues for understanding the ecological roles of bacterial and archaeal taxa in the degradation of the Zoige alpine wetland soil. The observed changes may serve as early warning signals of soil degradation in alpine wetlands.In summary, wetland degradation changed soil properties, which further affected specific bacterial and archaeal taxa involved in nutrient cycling resulting in distinct association patterns. 49. Eighty-five percent of precipitation is delivered from April to September. The mean annual air temperature is 1.1 °C33, with the average temperatures ranging from −10.1 °C in January to 10.7 °C in July.The Zoige Plateau is in the northeast of Qinghai-Tibetan Plateau  at an average altitude of 3500 m Table . The meaCarexmuliensis, Carexlasiocarpa and Carexmeyeriana). The meadow surface was in a humid state and the vegetation was dominated by mesophytes and hydro-mesophytes (Kobresiatibetica), and the water table was approximately 4.26 cm below ground. The sandy soil surface was continuously dry and had little or only few Psammophytes as vegetation cover50, and the water table was at least 21 cm below ground. The soil texture was peat soil in SW, sandy loam in soil MD, and sandy soil in SD. The parent materials of swamp and meadow soils were homogeneous silt clay and Triassic slate residues, and sandstones and siltstone, respectively51. In the sandy soil, the top layer (0–30 cm) was mostly sand and rest was composed of aeolian parent material52. Based on the FAO soil taxonomy system53, the SW soil is classified as Histosol, the MD soil as Haplic Calcisol, while the SD was Arenosol.Swamp soil (SW), meadow soil (MD) and sandy soil (SD) in Zoige were sampled in August 2014. The swamp was covered with water with an annual average water table of 5.87 cm above ground. The vegetation was dominated by hydrophytes and sedge hydro-mesophytes  was determined by oven-drying at 105 °C for 48 h54. Soil total nitrogen (TN) and available nitrogen (AN), total phosphorus (TP) and available phosphorus (AP), total potassium (TK) and available potassium (AK) were determined by Kjeldahl digestion, alkaline hydrolysis diffusion method, and molybdenum blue method and flame photometry, respectively54.Soil pH and soil organic carbon (SOC) were determined using a soil-to-water ratio of 1:5 and dichromate oxidization method, respectivelyDNA was extracted from 0.75–0.91 g fresh weight soils (corresponding to 0.50 g dry weight) using the FastDNA Spin Kit for Soil  following the manufacturer’s instructions. The quality of DNA was examined using the Nano-200 spectrophotometer . DNA samples were stored at −20 °C.55. The reverse primer was combined with the adapter and barcode sequences for multiplexing. Amplification was done in 50 μl-reaction volumes containing 3 U of TaKaRa Ex Taq HS , 5 mM dNTP Mixture (TaKARA), 2.0 mM MgCl2, 5 μl of 10× Ex Taq Buffer (TaKARA), 0.5 mM of each primer and 2.5 ng of soil DNA. The PCR procedure included an initial denaturation at 94 °C for 4 min, 30 cycles of 15S at 94 °C, 15S at 55 °C and 30S at 72 °C, and a final extension at 72 °C for 10 min.PCR amplification was carried out using the primers 515F (5′-GTGCCAGCMGCCGCGGTAA-3′) and 806R (5′-GGACTACVSGGGTATCTAAT-3′) targeting the V4 hyper variable region in the bacterial and archaeal 16S rRNA genehttps://www.ncbi.nlm.nih.gov/sra/) with accession number SRS2127453.PCR products were purified using PCR Clean-up Purification Kit  and quantified using Qubit 2.0 fluorimeter . Purified amplicons were pooled in equimolar concentrations and sequenced using MiSeq Reagent Kit V2 for Illumina MiSeq. The raw sequence data were submitted to NCBI Sequence Read Archive  at 97% using the UPARSE pipeline57. The RDP classifier was used to assign OTU representative sequences at 70% threshold56. For inter-group comparison, OTUs were randomly resampled at a depth of 12822 sequences. Singletons were eliminated during resampling, results in 35,014 OTUs. The phylogenetic tree was generated based on the representative sequences and used for UniFrac distance calculations.Sequence reads were quality-filtered in QIIME (v1.9.1)58. Two-way ANOVA was performed to test differences in the abundances of taxa at family level at P < 0.05. Principal coordinate analysis (PCoA) based on weighted and unweighted UniFrac distances were carried out in the R package vegan60. Distance based redundancy analysis (dbRDA) was performed to investigate factors driving community variation. Significance of factors was calculated by the permu test function in vegan over the dbRDA model using a maximum of 999 permutations. The goodness of fit for each edaphic factor was estimated by applying the envfit function in vegan (999 permutations). Mantel test was used to determine correlations between soil properties and microbial community composition.We applied principal component analysis (PCA) to assess differences in properties between soils. Analysis of similarity (ANOSIM) was used to test significant differences among abundances of taxa. The relative abundances of taxa at phylum and family levels were analyzed using R2-fold transformed abundances at phylum and genus levels61. Differential abundance analysis was performed by fitting a generalized linear model with a negative binomial distribution to the normalized value for each type of taxa, and testing for differential abundance using a Wald test61. P-values were adjusted for multiple testing following the procedure of Benjamini and Hochberg62, and a false discovery rate (FDR) of 10% was selected to denote statistical significance63. Taxa with significant changes in abundance were defined as those that had differential abundance >1.0 and FDR-adjusted P < 0.1. Correlations between taxa with significant changes in abundance and edaphic features were determined using Spearman’s rank correlation.The R package DESeq2 was used to analyze differential log64. Firstly, a Spearman’s rank correlation coefficient matrix was calculated using “scipy” Python package for adjacency matrix construction60. To get robust links among nodes in the network, we further corrected all P-values using the Benjamini and Hochberg false discovery rate (FDR) as performed in “multtest” R package65. The cutoffs of correlation were determined as ±0.75 based on random theory-based methods66. The networks were generated using the “igraph” Python package based on cutoffs of correlation (FDR-P < 0.001)67. The network topological properties were calculated to evaluate the importance of each OTU (nodes). OTUs that were strongly correlated were screened using greedy modularity optimization algorithm68. To identify the primary driving force of modularity, we fit taxon abundance and edaphic factors to Bray-Curtis dissimilarities of modules to find the group of taxa and edaphic factors with highest correlation coefficient. The goodness of fit for each taxon and edaphic factor were estimated by the envfit function in vegan R package (999 permutations). Relations between the nodes of networks and soil properties were evaluated by Mantel test and partial Mantel test.To reduce the complexity of the network, only OTUs with significant abundance variation among groups were considered for co-abundance network construction, which was then visualized in Cytoscape v3.3.0https://www.ncbi.nlm.nih.gov/sra/) with accession number SRS2127453. The OTU table is accessible in Dryad database with doi:10.5061/dryad.ks767.Sequencing data were submitted to NCBI Sequence Read Archive database (Supplementary InformationDataset 1Dataset 2


As predicted, rats (n = 7) trained to perform the simultaneity judgment task could accurately (~80%) identify synchronous vs. asynchronous (200 ms SOA) trials. Moreover, the rats judged trials at 10 ms SOA to be synchronous, whereas the majority (~70%) of trials at 100 ms SOA were perceived to be asynchronous. During the temporal order judgment task, rats (n = 7) perceived the synchronous audiovisual stimuli to be “visual first” for ~52% of the trials, and calculation of the smallest timing interval between the auditory and visual stimuli that could be detected in each rat ) ranged from 77 ms to 122 ms. Neurons in the rat V2L cortex were sensitive to the timing of audiovisual stimuli, such that spiking activity was greatest during trials when the visual stimulus preceded the auditory by 20–40 ms. Ultimately, given that our behavioral and electrophysiological results were consistent with studies conducted on human participants and previous recordings made in multisensory brain regions of different species, we suggest that the rat represents an effective model for studying audiovisual temporal synchrony at both the neuronal and perceptual level.Extensive research on humans has improved our understanding of how the brain integrates information from our different senses, and has begun to uncover the brain regions and large-scale neural activity that contributes to an observer’s ability to perceive the relative timing of auditory and visual stimuli. In the present study, we developed the first behavioral tasks to assess the perception of audiovisual temporal synchrony in rats. Modeled after the parameters used in human studies, separate groups of rats were trained to perform: (1) a simultaneity judgment task in which they reported whether audiovisual stimuli at various stimulus onset asynchronies (SOAs) were presented simultaneously or not; and (2) a temporal order judgment task in which they reported whether they perceived the auditory or visual stimulus to have been presented first. Furthermore, using  Within the mammalian brain, there exist functionally-specialized regions, such as the superior colliculus and higher-order cortical areas, which are populated by neurons capable of merging information from more than one sensory modality , which describes the actual timing of the audiovisual stimuli when the observer is most unsure of the temporal order and; (2) the observer’s just noticeable difference (JND), which represents the smallest interval between the separately presented auditory and visual stimuli that can be detected reliably , and the observers must judge the relative timing of the stimuli by stating which one came first or which came second  differentiate whether audiovisual stimuli at various SOAs were presented synchronously or not ; or (2) determine the temporal order of audiovisual stimuli presented at various SOAs . Ultimately, psychophysical curves were generated for both of the behavioral paradigms, and the PSS and JND were calculated for the temporal order judgment task. Furthermore, prior to commencing the design of the novel behavioral tasks, we first performed ad libitum. All experimental procedures were approved by the University of Western Ontario Animal Care and Use Committee and were in accordance with the guidelines established by the Canadian Council of Animal Care.The present study included three experimental series that each used a separate group of adult male Sprague-Dawley rats . Rats were housed on a 12-h light-dark cycle with food and water n = 7; body mass: 420 ± 11.8 g) were anesthetized with ketamine  and xylazine  and fixed in a stereotaxic frame with blunt ear bars. The absence of a pedal withdrawal reflex was an indication of anesthetic depth, and supplemental doses of ketamine/xylazine were administered (IM) as needed. A midline incision was made in the skin of the scalp, and the tissue overlying the dorsal aspect of the skull was removed. A stainless steel screw was inserted in the left frontal bone to serve as an anchor for a headpost and as an electrical ground. A stereotaxic micromanipulator was used to measure 5.5 mm caudal to bregma, which represents an approximate rostral-caudal location of the V2L . Neural signals were acquired using a 32-channel microelectrode array which consisted of a single shank with 32 recordings sites equally-spaced, spanning 1.5 mm in length . The microelectrode array was connected to a high-impedance headstage , and the electrophysiological signal was preamplified and digitized , and sent to a RZ5 processing module via a fiber optic cable. The neuronal activity was detected online  using a voltage threshold for spike detection of three standard deviations above the noise floor. The timing of the detected spikes and their associated waveforms were stored for offline analyses.A single penetration was completed in each experiment, whereby the microelectrode array was inserted in the cortex through a small slit in the dura using a dorsomedial-to-ventrolateral approach (40° angle), with the array entering the cortex 5.5 mm caudal to bregma and approximately 1 mm medial to the temporal ridge of the skull. The array was inserted into the cortex using a stereotaxic micromanipulator  at a 40° angle until all recording sites were within the cortex (depth of 1.5 mm) based on visual confirmation using a surgical microscope equipped with a high-resolution camera. Once the electrode sites were no longer visible, a hydraulic microdrive  was used to slowly advance the array into the cortex until the 32 recording sites spanned a distance of 1.75–3.25 mm from the initial entry in the cortex. At this location, the recording sites were located within the V2L, a multisensory region responsive to auditory and visual stimuli  from a speaker  positioned approximately 10 cm from the right pinna on a 30° angle from midline . For each rat, the auditory stimulus  was presented at 30 dB above its threshold to a click (0.1 ms) stimulus (22.8 ± 1.5 dB SPL) as determined by an initial assessment of hearing sensitivity using our previously described auditory brainstem response paradigm  and custom Matlab software. Auditory and visual stimuli were presented alone in order to determine the sensory responsiveness of each of the multi-unit (MU) clusters sampled during the experiment. The combined audiovisual stimuli were presented at various SOAs in which the visual stimulus was presented either 80, 60, 40 or 20 ms before the auditory stimulus, at the same time as the auditory stimulus (0 ms onset), or 20, 40, 60 or 80 ms after the auditory stimulus. In addition to the auditory alone, visual alone and nine audiovisual conditions, the paradigm also included trials in which no stimulus was presented in order to collect spontaneous activity. Overall, the trial conditions were presented in a pseudorandomized order, separated by an inter-trial interval of 3–5 s, and each condition was presented 50 times.t-test  in preparation for a transcranial perfusion with 0.1 M phosphate buffer (PB), followed by 4% paraformaldehyde. The brain was then removed and post-fixed in paraformaldehyde for 12 h, followed by storage in 30% sucrose. Coronal sections (40 μm) were cut using a freezing microtome . After staining with thionin, the coronal sections were imaged with an Axio Vert A1 inverted microscope . ZEN imaging software was used to reconstruct the location of each recording penetration  were trained 6 days per week using a two-alternative forced-choice operant conditioning paradigm to differentiate between trials when a visual stimulus was presented simultaneously with an auditory stimulus , or when the visual stimulus preceded the auditory stimulus by 200 ms . As described in detail below, once the rats were proficient at the training task, occasional testing days occurred in which novel SOAs were also added to the paradigm whereby the visual stimulus preceded the auditory stimulus by 0, 10, 40, 100 or 200 ms. These testing days took place when the rats were between 6 and 11 months of age (body mass at the last day of testing: 449 ± 16.3 g), and allowed for the determination of each rat’s judgment of simultaneity.A separate group of adult male rats , which was housed in a sound-attenuating box . The behavioral chamber was illuminated by a house light located on the back wall, whereas the front wall was equipped with a center nose poke, a left feeder trough and a right feeder trough; each fitted with an infrared (IR) detector. Stimulus delivery, nose-poke responses and positive/negative reinforcement were controlled and monitored using custom Matlab behavioral protocols running in Matlab  resulted in: (1) the immediate presentation of an audiovisual stimulus combination that was either synchronous  or asynchronous ; and (2) the delivery of a 45 mg food pellet  to the associated feeder trough . Furthermore, if the rat went to the correct feeder trough following the stimuli presentation (as monitored with the IR detector), a second pellet was delivered so as to help the rat associate a given feeder trough with a particular audiovisual SOA.Once the rats were able to frequently nose poke in the center port , the initial pellet reinforcement was removed, and now the pellet delivery was contingent on the rat poking its nose in the correct feeder trough in response to the given audiovisual SOA. At this stage, the audiovisual asynchronous stimuli onset remained at 400 ms. During each 30-min daily training session, correct feeder trough responses were reinforced with a food pellet, whereas incorrect responses resulted in the house light turning off for 15 s, during which time the rat was unable to initiate a new trial Figure . ThroughRats remained on the 0 ms vs. 400 ms SOA protocol until they correctly identified the synchronous and asynchronous audiovisual combinations with >75% accuracy. Upon achieving this performance criterion for three consecutive days, the asynchronous SOA was reduced to 300 ms. Training continued in sessions of 30 min/day or to the completion of 200 trials until a criterion of 75% correct was reached for both synchronous and asynchronous stimuli on five consecutive days. During the final training stage of the simultaneity judgment task, the asynchronous stimuli onset was reduced to 200 ms. As described below, after the rat had achieved >80% accuracy for five consecutive days on the final training stage , “testing” days were performed approximately once a week.To determine each rat’s perception of simultaneity , novel SOAs were introduced. On average, rats underwent testing once a week, in which five SOAs were randomly presented  were trained 6 days per week using a two-alternative forced-choice operant conditioning paradigm to differentiate the temporal order of auditory and visual stimuli . As outlined in the following sections, once the rats were proficient at the training task, occasional testing days occurred in which novel SOAs  were also added to the paradigm. Ultimately, the testing days, which took place when the rats were between six and eight months of age (body mass at the last day of testing: 422 ± 11.6 g), allowed for the determination of each rat’s perception of audiovisual temporal order.Using the same behavioral apparatus and sensory stimuli described in Experiment 2, a separate group of adult male rats , frequency of training (6 days per week), positive/negative reinforcement, as well as an incremental progression through the various training stages. Importantly, in contrast to the simultaneity judgment task, rats in Experiment 3 received a food pellet for nose-poking the left feeder trough when the auditory stimulus preceded the visual stimulus by 400 ms, and for nose-poking the right feeder trough when the visual stimulus was presented 400 ms before the auditory stimulus Figure . Once thOn testing days, novel SOAs were introduced so as to determine each rat’s perception of the temporal order of the auditory and visual stimuli. On average, rats underwent testing days once a week, in which seven SOAs were randomly delivered . If Mauchly’s test of sphericity was violated within the repeated-measures ANOVA, the Greenhouse-Geisser correction was used. The level of statistical significance was set at α = 0.05. When appropriate, Bonferroni post hoc corrections were used to account for potential “family-wise” error , and paired samples n = 7) included in this experimental series underwent the same electrophysiology recording procedure, which consisted of a single penetration of the 32-channel microelectrode array into the V2L. In total, 224 waveform clusters were sampled, with 221 (98.7%) of these MU clusters being classified as responsive to at least one sensory modality. Of the MU clusters that were responsive to sensory stimuli, 97 (43.9%) were overtly responsive to only the visual stimulus, 90 (40.7%) were overtly responsive to only the auditory stimulus, and 34 (15.4%) were overtly responsive to both the auditory and visual stimuli . As described in the “Materials and Methods” Section, the mean firing rate and level of multisensory enhancement of each MU cluster were determined at the various audiovisual SOAs . These calculations were performed when the analysis window was either fixed at a given time interval  or when it was shifted according to the peak firing rate .All rats  = 0.693, p = 0.593) and level of multisensory enhancement  = 0.666, p = 0.585) of auditory-responsive MU clusters were not significantly affected by the various SOAs. This finding was not surprising given that the timing of the auditory stimulus did not vary during the SOA protocol; the onset of the visual stimulus shifted around the static auditory stimulus. Thus, because the spiking activity of the auditory-responsive MU clusters was consistently captured in the set window  = 64.186, p < 0.001), and Bonferroni corrected post hoc analyses revealed that the mean firing rate was significantly greater at +20, +40 and +60 ms SOA compared to the synchronous presentation of the audiovisual stimuli . Similarly, the level of multisensory enhancement was significantly greater at the +20, +40 and +60 ms SOA than when the audiovisual stimuli were presented synchronously, as determined by a one-way repeated measures ANOVA  = 57.049, p < 0.001) and Bonferroni corrected post hoc testing (p < 0.0125). Notice, however, that the level of multisensory enhancement in the visually-responsive MU clusters was well below 0% for the majority of the SOAs; again, an expected result due to the set window of analysis failing to capture the spiking evoked by the visual stimulus that moved in time.In contrast to the auditory-responsive MU clusters, the spiking profiles of neurons that responded exclusively to the visual stimulus were significantly affected by the set window analysis, as the fixed window often failed to capture the visually-evoked activity  = 6.201, p < 0.02) and level of multisensory enhancement  = 6.313, p < 0.02) observed in multisensory-responsive MU clusters. Furthermore, post hoc analyses found a increase in mean firing rate (p < 0.05) and multisensory enhancement (p < 0.01) at +40 ms SOA compared to when the audiovisual stimuli were presented synchronously  = 0.616, p = 0.635) and level of multisensory enhancement  = 0.707, p = 0.556) of auditory-responsive MU clusters did not significantly differ across the various SOAs when a peak-centered window of analysis was used  = 1.177, p = 0.342) or level of multisensory enhancement  = 1.853, p = 0.208) observed in visually-responsive MU clusters  = 5.466, p < 0.05) and level of multisensory enhancement  = 7.902, p < 0.01) of multisensory-responsive MU clusters. Furthermore, post hoc analyses found an increase in mean firing rate and multisensory enhancement at +20 ms and +40 ms SOAs compared to when the audiovisual stimuli were presented synchronously  = 366.024, p < 0.001), and Bonferroni corrected post hoc analyses found that the performance during the 40 ms SOA was significantly different from all of the other SOAs tested  from that of the synchronous trials. Collectively, these results provide a psychophysical profile of simultaneity judgment in rats.Over a series of stages, rats were trained using a two alternative forced choice paradigm to differentiate between audiovisual stimuli that were presented synchronously (0 ms SOA) and when the onset of the visual stimulus preceded the auditory stimulus by 200 ms. On average, training took place over 131 ± 7 days before they were able to undergo the testing procedures. Once the rats had become proficient at the training paradigm, five testing days were performed over the next two to three months in which novel audiovisual temporal onsets  were presented. At the 40 ms SOA, rats perceived the stimuli to be asynchronous on 40 ± 2.6% of the trials Figure . A one-wF = 138.460, p < 0.001), and Bonferroni corrected post hoc analyses found that the performance during the 0 ms SOA was significantly different from both the −200 ms (auditory first) and +200 ms  SOA  a simultaneity judgment task in which they reported whether audiovisual stimuli at various SOAs were presented at the same moment in time or at different times; and (2) a temporal order judgment task in which they reported whether they perceived the auditory or visual stimulus to be presented first. Rats were able to learn both tasks, and the resultant psychophysical curves were similar to those reported in humans  or at different moments in time , irrespective of whether the auditory or visual stimulus was presented first  have been shown to be engaged in the perception of audiovisual simultaneity , the rat V2L cortex—a well-established area responsive to audiovisual stimuli  Discovery grant and a Canadian Institutes of Health Research (CIHR) grant awarded to BLA.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.


In this work, graphene nanoplatelets (GNPs) were dispersed uniformly in aqueous solution using methylcellulose (MC) as a dispersing agent via ultrasonic processing. Homogenous GNP suspensions were incorporated into the cement matrix to investigate the effect of GNPs on the mechanical behavior of cement paste. The optimum concentration ratio of GNPs to MC was confirmed as 1:7 by ultraviolet visible spectroscopy (UV-Vis), and the optical microscope and transmission electron microscopy (TEM) images displayed remarkable dispersing performance. The GNP–cement composite exhibited better mechanical properties with the help of surface-modified GNPs. The flexural strength of cement paste increased up to 15%–24% with 0.05 wt % GNPs (by weight of cement). Meanwhile, the compressive strength of the GNP–cement composite increased up to 3%–8%. The X-ray diffraction (XRD) and thermal analysis (TG/DTG) demonstrated that the GNPs could accelerate the degree of hydration and increase the amount of hydration products, especially at an early age. Meanwhile, the lower porosity and finer pore size distribution of GNP–cement composite were detected by mercury intrusion porosimetry (MIP). In addition, scanning electron microscope (SEM) analysis showed the introduction of GNPs could impede the development of cracks and preserve the completeness of the matrix through the plicate morphology and tortuous behavior of GNPs. Ordinary Portland cement (OPC) is a crucial component of concrete, which is the most popular cementitious material for architectural structures. However, OPC paste is a typically brittle material due to low tensile strength, poor flexural strength and multiple initial cracks. Traditionally, various fibers or steel bars have been used to restrict the propagation of microcracks to improve the mechanical and electrical properties of plain cement materials ,2,3. For2/g [As an extensively attractive carbon nanomaterial, ideally, graphene is also able to remarkably reinforce cement-based materials due to its excellent mechanical properties. The average tensile strength and Young’s modulus of graphene are 125 GPa and 1.1 TPa ,11. In a2/g ,14,15 as2/g  found th2/g  observed2/g ,19,20.Graphene nanoplatelets (GNPs) consist of several graphene layers with a thickness in range of 3–100 nm . CompareAs a traditional surfactant, methylcellulose (MC) is always applied for the dispersion of CNTs and CNFs because of its wettability, dispersibility and adhesion properties ,32,33. IThe ability of MC to disperse GNPs in aqueous solution could be explored by UV-Vis absorbency spectra. According to the Lambert-Beer’s law, the higher absorbency implies that a better dispersion of GNPs in water. The optimum dispersing status of GNPs in aqueous MC solution was employed using TEM. By conducting slump flow test, the workability is evaluated and compared between the plain cement and the GNP–cement composite, as shown in The results of flexural strength and compressive strength of plain cement and GNP–cement composite at 3, 7, 14 and 28 days are shown in 2), ettringite (AFt). Compared with plain cement, there are no new phases of the GNP–cement composite, suggesting that the addition of GNPs cannot change the type and structure of final hydration products.The effect of GNPs on the products of cement hydration can be estimated using X-ray diffraction patterns. The XRD patterns of plain cement and GNP–cement composite are shown in 2 and AFt in GNP–cement composite are both higher than those in plain cement, which indicates the higher crystalline degree of Ca(OH)2 and AFt. Meanwhile, the intensity of unhydrated tricalcium silicate (C3S) in GNP–cement composite is much lower than that in plain cement, suggesting the higher hydration degree of the GNP–cement composite. The similar tendency also is observed at the age of 28 days, though the change is not very obvious in Furthermore, XRD analysis can also characterize the degree of cement hydration by monitoring the formation of hydration products and the consumption of cement raw constituent qualitatively. As can be seen in 2 in GNP–cement composite are higher than those in plain cement in Another common method to investigate the degree of hydration is thermal analysis. The TG/DTG curves of plain cement and GNP–cement composite at the age of 7 days and 28 days have been presented in 2/g) with pore size diameter (nm). The cumulative pore area of GNP–cement composite displays a decrease at various pore sizes compared with plain cement paste. The trend is similar to the change of total intrusion volume and porosity in The results of porosity test for cement paste with and without GNPs at 28 days are presented in As shown in The comparison of microstructures between the plain cement paste and GNP–cement composite is shown in In addition, GNPs performance in cement paste is found in In recent years, some studies have demonstrated that the introduction of graphene can remarkably enhance the mechanical properties of ceramic and cement composites ,37,38. IIn addition, the hydration process of cement paste can impact flexural and compressive strength significantly. Previous research showed the effect of carbon nanomaterials on the hydration degree and products of cement paste ,40,41. IThe interaction between the additives and the cement matrix also has a vital impact on the properties of cement composites. In the work, there is more obvious enhancement in the flexural strength than that of the compressive strength. Some studies found that the high improvement in the flexural strength of GNP composites was due to various toughening mechanisms, including stress dispersing, crack deflection, crack bridging, and cracking branching ,42. As sx-GnP-M25) were obtained from XG science, Inc. . The physical properties of GNPs are presented in The cement was provided by Dalian Onoda Cement Co., Ltd. , which belongs to P.O 42.5R cement (Ordinary Portland Cement) according to Chinese Standards. Its chemical composition and physical parameters are shown in Methylcellulose (MC) as dispersant was purchased from SINOPHARM Chemical Reagent Co., Ltd. . The superplasticizer (SP) was provided by Dalian Mingyuanquan Group Co., Ltd. . The tributyl phosphate (TBP) as defoamer was supplied by Tianjin Chemical Reagent Plant  in order to eliminate redundant bubbles introduced by dispersant.2). The treated GNP suspensions were tested to determine the best dispersion condition with regards to MC concentration.The 5 mg GNPs were added into 50 mL aqueous solution with different MC concentration (ranging from 0.2 g/L to 1.0 g/L), and the suspensions were mechanically stirred for 10 min and treated for 20 min using a sonicator . The blank was the aqueous MC solution under the same dispersing conditions as reference solution. TEM images of GNP suspensions were obtained by a Tecnai G2 Spirit  to represent the dispersing performance of GNP suspension. The GNP suspensions were pipetted onto a copper grid of carbon film, dried in air, and then observed in TEM.According to the Chinese standard “Methods for testing uniformity of concrete admixture”, the two composites were poured into a cone mould to perform the slump flow test. The dimensions of the cone mould are bottom diameter 60 mm, top diameter 36 mm, and height 60 mm, as shown in The flexural strength was carried out by three point bending fixture on a computer controlled electrohydraulic servo universal tester (WDW-50) at a speed of 0.5 mm/min. After the bending tests, the compressive strength of each fractured fragments was conducted on a computer controlled electro-hydraulic servo universal tester (WHY-300) at a rate of 0.01 mm/min. After mechanical property tests, these fragments, including plain cement paste and GNP–cement composite, were soak in anhydrous ethanol to terminate hydration reaction.The X-ray diffraction patterns of cement samples were recorded using an automatic diffractometer  with Cu radiation. The scan range was set for two-theta angles of 5° to 70° with a rate of 0.5 θ°/min. The hardened cement powder samples were carried out on the thermal analysis instrument . The temperature range was from 50 °C to 1000 °C at a heating rate of 10 °C/min.The porosity and pore size distribution of composites were detected using mercury intrusion porosimeter , with one high-pressure station, two low-pressure stations and a maximum pressure of 33,000 psia for measurements. In addition, an environmental scanning electron microscope  was performed to observe the microstructure of composites. The SEM was used in conjunction with energy dispersive spectroscopy (EDS).In this paper, GNPs were treated using MC as a dispersant to improve their dispersibility in aqueous solution. The optimum MC to GNPs ratio of 7:1 by concentration was confirmed using UV-Vis absorbency, and the dispersing performance of GNPs was characterized by optical microscope and TEM. Consequently, the uniform GNP suspensions were used to reinforce the cement matrix as mixing water. The effect of GNPs on the mechanical properties and microstructure of cement based materials were investigated with the help of XRD patterns, thermal analysis, MIP, and SEM analysis.The incorporation of 0.05% GNPs by weight of cement can enhance the flexural strength by 15%–24% and the compressive strength by 3%–8%. The XRD pattern and thermal analysis demonstrate that the degree of cement hydration has been promoted by GNPs, especially at an early age. Moreover, a more compact microstructure and finer pore size were detected in the GNP–cement composite using MIP and SEM analysis. However, more research is needed to improve the dispersibility of GNPs in cement matrix and the interfacial interaction between GNPs and the hydration products of cement. This study can provide a suitable method to investigate the two-dimensional nanomaterial for cement composites.


The polarisation characteristics of the electropolishing process in a magnetic field (MEP – magnetoelectropolishing), in comparison with those obtained under standard/conventional process (EP) conditions, have been obtained. The occurrence of an EP plateau has been observed in view of the optimization of MEP process. Up-to-date stainless steel surface studies always indicated some amount of free-metal atoms apart from the detected oxides and hydroxides. Such a morphology of the surface film usually affects the thermodynamic stability and corrosion resistance of surface oxide layer and is one of the most important features of stainless steels. With this new MEP process we can improve metal surface properties by making the stainless steel more resistant to halides encountered in a variety of environments. Furthermore, in this paper the stainless steel surface film study results have been presented. The results of the corrosion research carried out by the authors on the behaviour of the most commonly used material − medical grade AISI 316L stainless steel both in Ringer’s body fluid and in aqueous 3% NaCl solution have been investigated and presented earlier elsewhere, though some of these results, concerning the EIS Nyquist plots and polarization curves are also revealed herein. In this paper an attempt to explain this peculiar performance of 316L stainless steel has been undertaken. The SEM studies, Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were performed on 316L samples after three treatments: MP – abrasive polishing (800 grit size), EP – conventional electrolytic polishing, and MEP – magnetoelectropolishing. It has been found that the proposed magnetoelectropolishing (MEP) process considerably modifies the morphology and the composition of the surface film, thus leading to improved corrosion resistance of the studied 316L SS. The use of an externally applied magnetic field to the electropolishing process (EP) provides the treated metal surface with some new properties and better characteristics, including microroughness, hydrophilicity, contact angle, corrosion resistance, and oxide film morphology [For years, several positive features concerning electropolished metal surface have been ascribed to the so called rphology ,3,4,5,6.rphology ,14,15,16rphology ,8,9,10.Type UNS S31603 316L stainless steel is a low-carbon version of the AISI 316 stainless steel used extensively for many purposes due to its superior corrosion resistance, smoothness, biocompatibility and cleanability after electropolishing treatment ,18,19,20Medical grade 316L SS vm , is presently used extensively in medicine for implants. This grade of stainless steel has been used to avoid and/or minimize the danger of pitting corrosion by making these high potentials at which the pitting occurs highly improbable, although this generally depends on the individual human being involved.A variety of surface treatments are commonly performed on medical implant materials to promote corrosion resistance and biocompatibility ,13,14,15Electropolishing is usually an advised treatment to finish metallic implants in view of taking advantage of the selective dissolution of elements constituting a particular metallic material. Selective dissolution enriches the passive layer in an element in which oxide is the most corrosion resistant and haemocompatible. The best example is 316L austenitic stainless steel. Electrochemical corrosion tests performed on standard electropolished and magnetoelectropolished 316L-stainless-steel samples in a 3% aqueous NaCl solution showed remarkable improvement in overall corrosion resistance ,5,26,27.Electropolishing becomes even more complex if a magnetic field is introduced to the system ,27,28,29In this study the occurrence of the plateau and its level, and then the reference to the surface quality obtained has been presented. The results of the SEM, Auger spectroscopy, and XPS studies obtained herewith carried out on AISI 316L SS reveal very well the advantages of the magnetoelectropolishing process.2), potential to over 10 V, up to 20 V vs. MSE . For the studies a proprietary sulphuric/orthophosphoric acids mixture electrolyte was used. First the polarization characteristics have been studied. The EP studies were carried out over a broad range of current density changes  was used in the electrolyte temperature range up to 60 °C. The electrode has been marked as REF601. The MSE reference element is based on Hg/Hg2SO4 and it uses a filling solution of saturated K2SO4. At 25 °C the REF601 potential versus a saturated calomel electrode is approximately 407 mV. This type of MSE reference electrode was successfully applied earlier by the authors [For reference a mercury-sulphate Hg/Hg authors  during iThe electrolytic polishing was performed both in the absence and in the presence of a magnetic field. A hallothrone device of type SMS-102 was used to measure the magnetic field strength. For the MEP experiments, a constant external magnetic field of 350 mT was applied to the EP system by a neodymium magnet. For both processes, conventional EP and MEP, the same type of a proprietary acidic electrolyte was used. The bath was unstirred during the process of MEP, and under a variety of electrochemical conditions during EP. During the investigation, measurement of polarization curves were performed on all stainless steel samples’ surfaces during both EP and MEP. The electrochemical system used for the investigation consisted of an ATLAS 98 potentiostat equipped with POL 98 software.For these experiments, medical grade AISI 316L stainless steel was used . Three sThe samples after mechanically abrasive polishing (MP) were used as a reference. For both electrochemical polishing processes, conventional/standard electropolishing (EP) and magnetoelectropolishing (MEP), the same type of a proprietary electrolyte was applied, being a mixture of sulphuric and orthophosphoric acids. Both electrolytic polishing processes, EP and MEP, were performed in a round, transparent electrochemical cell. The magnetoelectropolishing (MEP) was performed under identical conditions to those used for standard electropolishing process, except for the externally applied magnetic field. The magnets were magnetized by their thickness. The imposed magnetic field of about 350 mT was directed parallel to the electropolished workpiece surface (sample). During both electropolishing (EP) and magnetoelectropolishing (MEP) the bath was unstirred and temperature was kept within 60±1 °C. Prior to the MEP surface studies, the samples were thoroughly degreased in acetone. 2, and a saturated calomel electrode (SCE) EK-101P used as a reference. The sample surface area exposed for the study each time was 2.01 cm2. Polarization curves were measured in the potential interval from −1,000 mV to 1,500 mV at a scan rate of 1 mV·s-1. The EIS results were obtained each time after holding the samples at open circuit potential (OCP) for 60 minutes. The corrosion resistance studies of the AISI 316L SS after three types of treatments – MP, EP, and MEP – were performed by investigating the Electrochemical Impedance Spectroscopy (EIS) and polarization curves in a typical Ringer’s solution at a room temperature (about 25 °C). The electrochemical system used for the corrosion measurements consisted of the ATLAS 98 potentiostat with the POL 98 software, current platinum electrode Ept-101 of surface area of 25 mmSEM studies, Auger electron spectroscopy (AES) and XPS measurements were carried out on the MP, EP, and MEP 316L SS samples. The AES was performed under an electron energy of 3 keV. The XPS experiments were performed using a SCIENCE SES 2002 instrument. The studies were carried out under standard conditions within the binding energy BE range of −1,100 eV to 0 eV.Initially the polarization characteristics under conventional (EP), and magnetoelectropolishing (MEP) conditions have been studied. The results are presented in -1. The lowest cd plateau was obtained under a conventional EP in still electrolyte and it equaled about 8 A/dm2, then with a moderate mixing it rose up to about 33 A/dm2. Under MEP conditions (350 mT) the obtained plateau level was in between the two higher given values, and equaled about 23 A/dm2. In The polarization curves were obtained at an electrolyte temperature of 60±1 °C and a scan rate of 1 mV·sIn In The scanning electron spectroscopy (SEM) investigation results are presented in The Auger electron spectroscopy results are presented in The XPS studies on 316L SS samples, after MP, EP, and MEP have been carried out within the binding energy of −1100 eV to 0 eV and the general results are presented in The presented XPS results in the whole range of binding energy  after eaxOy in each case, with varying amount of metallic iron after each consecutive kind of treatment: MP, EP, and MEP. The highest amount of free iron occurs after abrasive polishing  is presented indicating no free metal atoms contents after magnetoelectropolishing MEP. In The numerical amounts of oxides and pure metal atoms on 316L SS samples, after MP, EP, and MEP have been presented in Intially the polarization characteristics of the MEP process seem to be very similar to those in a standard/conventional electropolishing EP . The curThe AES results clearly show the difference between the composition of oxide film formed on MP, EP, and MEP samples see . One may2O3 oxides dominate for BE equaling −710.9 eV, and FeOOH compounds appear on EP and MEP 316L SS surfaces for BE equaling −711.8 eV. When analyzing the XPS iron region for binding energy BE equalling from −730 eV to −700 eV the progressive metallic iron washing out is observed starting from MP, through EP until MEP surfaces to a complete disappearance of that element after magnetoelectropolishing MEP see . On MP 32O3 oxides are apparent for binding energy equaling −576.8 eV. After MEP of 316L SS sample the hydroxides Cr(OH)3 occur for binding energy equaling −577.3 eV, and some non-stoichiometric CrOx oxides occur, with x below 3, for binding energy equaling −578.3 eV. The occurrence of oxides and hydroxides of chromium and iron on 316L SS surface layer after electrolytic polishing (EP) were reported also by Selvaduray and Trigwell [When analyzing the XPS chromium region for binding energies from −600 eV to −560 eV the metallic chromium peak is observed on MP and EP 316L SS surfaces for a binding energy of −574.4 eV see . On the Trigwell , and KerTrigwell ,27, and The magnetoelectropolishing process carried out with oxygen evolution contradicts, to some degree, all three of the established electropolishing theories. When the electropolishing process is carried out under the oxygen evolution regime, the properties of oxygen and its behaviour in a magnetic field are the critical factors. Oxygen is a paramagnetic element with two unpaired electrons that are attracted and aligned by a magnetic field. It is believed that some oxygen molecules, which are released during decomposition of the oxide layer, escape to the electrolyte. Others are attracted by the nonzero magnetic field. Those attracted oxygen molecules likely migrate toward the metal surface through the cyclically oxidized surface, or through vacancy sites, and dissociatively adsorb. This makes the oxide-hydroxide layer more compact and homogenous and thus more difficult to dissolve. The dissociatively adsorbed oxygen must be responsible for the decrease in current density and, consequently, for the rate of dissolution of electropolished material.The characteristic feature of MEP process of steel surface is eliminating free metals from the film see  which haThese Auger and XPS studies have evidenced that changes in composition of the surface film appear to have a decisive influence on the 316L SS corrosion behaviour. Thus, presented in other authors’ papers ,27,28, i(1)the plateau in the course of polarization curve during MEP with 350 mT was found to be between the plateaux of standard EP carried out in still and moderately mixed electrolyte.(2)the treated 316L SS samples indicate improving corrosion resistance in halide media from the least, after MP, through EP, to the best after MEP.(3)electrolytic polishing of 316L SS in a magnetic field (MEP) results in disappearance of both metallic Cr and Fe and formation of oxides and hydroxides of these metals.(4)2O3 to FeOOH and from Cr2O3 into Cr(OH)3 and CrOx  is apparent on the samples after MEP.a noticeable change in chemical composition on the studied 316L SS surfaces from Fe(5)the magnetic field applied for electropolishing of 316L SS results in selective leaching of magnetic elements like Fe and Ni from the non-magnetic austenitic steel.The investigation results presented show the differences both in polarization characteristics obtained during EP and MEP, corrosion resistance, and in the surface film morphology and composition of a medical grade 316L stainless steel between mechanically polished MP, standard electropolished EP, and magnetoelectropolished MEP surfaces. Thus modified 316L stainless steel surface film composition well coincides with the results showing improved corrosion behaviour of the samples obtained after three treatments: MP, EP, and MEP. The following additional conclusions may be drawn from the studies:The modified 316L SS sample surface after MEP process has indicated a decreased corrosion rate in Ringer’s body fluid. All used surface study techniques, SEM, the Auger spectroscopy, and XPS examinations revealed advantageous changes in the surface film formed on AISI 316L SS resulting from incorporation of the magnetic field into electropolishing process. Magnetoelectropolishing seems to be a reasonable process for using it to modify metal surface film composition and improve performance of 316L SS biomaterial.


Objective. To evaluate safety and efficacy of intravenous ferric carboxymaltose (FCM) versus standard medical care (SMC) for iron-deficiency anemia (IDA) in postpartum women and women with heavy menstrual bleeding. Study Design. This open-label, multicenter study randomized women with IDA (hemoglobin ≤ 11.0 g/dL) to single doses of FCM (15 mg/kg [maximum 1000 mg]) or SMC (this treatment was determined by the investigator and there may have been no treatment). Safety data (primary outcome) were collected for 30 days. Results. Of 2045 subjects enrolled , 996 received FCM and 1022 received SMC. At least 1 serious adverse event (AE) was reported by 0.6% and 2.2% of subjects in the FCM and SMC groups, respectively; none were considered treatment related. The difference in serious AEs was primarily due to higher rates of uterine leiomyoma, uterine hemorrhage, and menorrhagia in SMC subjects with heavy menstrual bleeding. Common AEs were generally predictable, with higher rates of infusion site reactions in FCM subjects and gastrointestinal AEs in SMC subjects. Mean hemoglobin increases were greater in the FCM group than the SMC group. Conclusion. FCM was well tolerated and effectively increased mean hemoglobin levels in postpartum women or women with heavy menstrual bleeding and IDA. This trial is registered with ClinicalTrials.gov, NCT00548860. Iron deficiency is the most common cause of anemia , 2. WomeIron therapy can be administered orally or parenterally , 4, 8. OFerric carboxymaltose (FCM) is a Type I polynuclear iron (III)-hydroxide carbohydrate complex that produces a slow and controlled delivery of the complexed iron to endogenous iron binding sites , 14. In An open-label, randomized study was conducted at 130 sites and consisted of a screening visit and 2 study visits at day 0 and day 30. Each site received institutional review board approval before initiation of the study, and informed consent was obtained from each subject prior to participation. This study was conducted in compliance with Good Clinical Practice guidelines and the Declaration of Helsinki.Women with IDA in the postpartum period were eligible to participate if they had hemoglobin levels ≤  11.0 g/dL obtained at least 18 hours after delivery. Women with heavy menstrual bleeding were eligible if they had hemoglobin levels ≤ 11.0 g/dL or point-of-care hemoglobin levels ≤ 11.5 g/dL. Heavy menstrual bleeding was defined as ≥1 of the following within the preceding 6 months: (a) inability to control flow with tampons alone, (b) use of >12 pads per period or 4 tampons per day unless subject was unusually fastidious, (c) passage of clots, or (d) period duration >7 days.Exclusion criteria included recent (≤3 months) gastrointestinal bleeding or significant acute blood loss (other than at delivery); a history of anemia other than IDA due to pregnancy/delivery or heavy menstrual bleeding; current treatment with myelosuppressive therapy or asthma therapy; and recent administration (≤1 month) of blood transfusion, IV iron, erythropoietin, or investigational drug. Women who were pregnant or had a history of hypersensitivity to FCM or were planning surgery or had an active infection including hepatitis B or C, known human immunodeficiency virus seropositivity, a history of malignancy, hemochromatosis, significant cardiovascular disease, elevated liver enzymes, alcohol abuse, or drug abuse were also excluded from study participation. Subjects were also excluded from participation on day 0 if they had point-of-care hemoglobin levels > 12.0 g/dL or a systolic blood pressure > 160 or <80 mm Hg or a diastolic blood pressure > 100 or <40 mm Hg prior to randomization.Subjects were randomized in a 1 : 1 ratio using a central interactive voice response system to receive either IV FCM or SMC . Randomization was stratified by etiology of IDA ; baseline hemoglobin levels ≤ 8.0, 8.1 to 9.5, or >9.5 g/dL; cardiac risk category (low or high); and past response to oral iron (poor or not poor). Subjects with 1 or no cardiac risk factors were designated as having low cardiac risk. Subjects with 2 or more cardiac risk factors, including smoking, high blood pressure, high blood cholesterol, diabetes, overweight or obesity, physical inactivity, and family history of heart disease (father/brother before age 55 years or mother/sister before age 65 years), were designated as having high cardiac risk.Subjects in the FCM group received FCM 15 mg/kg (up to a maximum of 1000 mg) in a slow IV infusion over 15 minutes on day 0. Prepregnancy weight was used to determine the FCM dose for postpartum subjects. Sitting pulse and blood pressure were monitored before, immediately after, and at 30 and 60 minutes after administration of IV iron.Subjects in the SMC group were treated for IDA as determined by the investigator from day 0 through day 30. Ferrous sulfate 325 mg tablets  were provided to the subject as study medication if the investigator determined it to be the best method of treatment. All subjects randomized to receive SMC were considered to have started treatment, as no treatment was an option.Safety was assessed by measurement of vital signs and findings on physical examination in addition to hematology, chemistry, and iron indices determined from blood samples obtained at day 0 and day 30. Treatment-emergent AEs were recorded from administration of study drug for FCM-treated subjects and after randomization for SMC subjects through completion of the study (day 30) or 30 days after last dose of study drug, whichever was later. When subjects returned to the clinic on day 30, AEs were elicited by use of nonspecific questions. Subjects were encouraged to report AEs at their onset, and all AEs, whether elicited, reported spontaneously, or observed by the physician or study staff, were recorded with date of onset, relationship to study medication based on investigator opinion, action taken, and date of resolution if the AE resolved. Allergic reactions were classified according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0, including grading of all events to quantify severity. Follow-up telephone calls to collect AEs were made 30 days after the last dose of study drug to all FCM-treated subjects who terminated early and 30 days after last dose of study drug to all SMC subjects.The primary goal of this study was to assess safety. The safety population included all FCM-treated subjects who received a dose of FCM on day 0 and all randomized SMC subjects. A sample size of 750 subjects per group provided approximately 80% power to detect a statistically significant difference in the incidence of serious AEs, when the incidence was 5.25% for FCM and 2.5% for SMC. The primary endpoint was the incidence of serious AEs, including death, hospitalization, disability, congenital anomaly/birth defect, and life-threatening events. Other safety endpoints included incidence and severity of AEs and treatment-emergent abnormal clinical laboratory values. Quantitative endpoints were summarized descriptively using mean, standard deviation, median, and range, and investigators judged the clinical significance of laboratory abnormalities. Differences between treatment groups were assessed using Fisher's exact test. All tests were 2-tailed with 0.05 alpha level. Efficacy was assessed as the mean change from baseline to highest postrandomization value for hemoglobin and ferritin levels, which were compared by cause of anemia across treatment groups and use of 1-way analysis of variance.n = 1023) or SMC (n = 1022)  . In the  = 1022) . No nota = 1022) . The cauThe mean dose of FCM during the study was 944 mg for all subjects, 926 mg for postpartum subjects, and 970 mg for subjects with heavy menstrual bleeding. Two subjects received an incorrect dose of FCM owing to the use of an incorrect body weight for weight-based dosing; in both cases, the incorrect dose was ≤1000 mg of FCM. Oral iron therapy  was initially prescribed for 93% of subjects randomized to SMC; no treatment was received by 2.4% of SMC subjects. The SMC subjects who received oral ferrous sulfate as study medication had a mean compliance rate of 95.2%. Based on the number of pills taken versus the number of pills prescribed, similar prescribing and compliance rates in the SMC subjects were observed between the postpartum and heavy menstrual bleeding populations.P = 0.004). The investigators did not consider any serious AE in either treatment group to be related to study medication. In the FCM group, the incidence of serious AEs was similar for postpartum subjects and subjects with heavy menstrual bleeding . In the SMC group, subjects with heavy menstrual bleeding had a higher incidence of serious AEs than postpartum subjects . The increased incidence of serious AEs in the subjects with heavy menstrual bleeding receiving SMC was primarily due to higher rates of uterine leiomyoma, uterine hemorrhage, and menorrhagia.The incidence of serious AEs was statistically significantly higher among subjects in the SMC group (22/1022 [2.2%]) than among those in the FCM group  subjects in the FCM group and 22 (2.2%) subjects in the SMC group discontinued study drug early owing to the occurrence of AEs . The proP = 0.841). The incidence of injection site reactions  was higher in the FCM group, and the incidence of gastrointestinal AEs  was higher in the SMC group  than subjects in the SMC group.At least 1 AE was experienced by 27.3% (272/996) of subjects in the FCM group and 26.9% (275/1022) of subjects in the SMC group (MC group . SubjectP = 0.0013) and in the SMC group . In both treatment groups, postpartum subjects and those with heavy menstrual bleeding had statistically significantly different rates of gastrointestinal events  and general disorders and administration site conditions .AEs are summarized separately in Four subjects (0.4%) in the FCM group  and no subjects in the SMC group experienced hypersensitivity reactions during the study. All hypersensitivity events were Grade 1 in severity. Two subjects in the FCM group  were reported to have hypotension during the study; both AEs were Grade 1 in severity, and neither subject had a history of hypotension.P < 0.001). The difference was more pronounced in subjects with heavy menstrual bleeding; 21.3% of subjects with heavy menstrual bleeding in the FCM group had a transient decrease in serum phosphorus compared with only 0.7% of subjects with postpartum anemia. These changes were not associated with clinical symptoms. No other treatment-emergent abnormal clinical chemistry values were observed.A significantly greater proportion of subjects in the FCM group than in the SMC group had a transient decrease in serum phosphorus . In the FCM group, the mean increase in hemoglobin from baseline to highest value was similar between subjects with postpartum anemia and those with heavy menstrual bleeding . In the SMC group, the mean increase in hemoglobin was greater in postpartum subjects than in subjects with heavy menstrual bleeding .Subjects treated with FCM and SMC experienced improvements in hemoglobin from baseline to the highest value during treatment, and subjects treated with FCM with either postpartum anemia or heavy menstrual bleeding experienced significantly greater mean increases in hemoglobin and ferritin levels from baseline to highest value compared with subjects treated with SMC . Mean heP < 0.001; SMC: 26.55 versus 7.95 ng/mL, P < 0.001). In the FCM group, the mean increase in ferritin from baseline to highest value was larger in subjects with postpartum anemia than in subjects with heavy menstrual bleeding . In the SMC group, a mean decrease was observed in the subjects with postpartum anemia compared with a mean increase observed in subjects with heavy menstrual bleeding .In both treatment groups, mean ferritin levels at baseline were higher in postpartum subjects than in subjects with heavy menstrual bleeding  and multidose (n = 703) safety trial of FCM versus SMC  for the treatment of IDA associated with a variety of medical conditions including gastrointestinal disorders, chronic kidney disease, heavy menstrual bleeding, and postpartum-related anemia [Barish and colleagues published findings of a single dose (d anemia . The maxWe observed a higher incidence of hypophosphatemia in the FCM group compared with the SMC group. The majority of hypophosphatemia events occurred in women with heavy menstrual bleeding who received FCM. Transient decreases in serum phosphorus have been reported in other studies of FCM –17, 20. Similar to the previously reported trials, efficacy outcomes in the current trial demonstrated that FCM was superior to SMC in improving hemoglobin and correcting IDA –17. TreaThe safety and efficacy of FCM compared with currently available IV iron could not be assessed in this trial because more than 90% of subjects in the SMC group received oral iron. In a noninferiority study in 2584 subjects, FCM was found to be noninferior to IV iron sucrose in subjects with non-dialysis-dependent chronic kidney disease . In anotIn conclusion, this study demonstrated that a single dose of FCM up to 1000 mg, given by IV infusion, is safe and effective in the treatment of IDA in postpartum women and women with heavy menstrual bleeding. FCM improves hemoglobin levels and replenishes iron stores more effectively than oral iron.


Good quality wound dressings should have exceptional properties for usage, such as being able to remove excess wound exudates, having rapid dehydration, and providing optimal water vapour permeability. This study evaluated and compared the morphological and physical properties of six different commercially absorbent wound dressings in Thailand: two hydrocolloids, two alginates, and two foams. These wound dressings are available in a variety of components and structures, some of which have a multilayer structure. The results showed that the calcium sodium alginate dressings had better absorption properties than the calcium alginate dressings, hydrocolloid dressings, hydrocolloid with foam layer dressings, foam with polyurethane film layer dressings, and foam with hydrogel and polyurethane film layer dressings. Furthermore, the calcium sodium alginate dressings had the highest rate of dehydration and provided an optimal water vapour transmission rate. However, the calcium sodium alginate dressings could not retain the original structure after being submerged with a wound exudate. In aA number of materials were used in this study. These included hydrocolloid dressing (Nexcare™) manufactured by the 3 M Company, Minnesota, United States of America; hydrocolloid with a foam layer dressing (DuoDERM®CGF™) produced by ConvaTec Inc., New Jersey, United States of America; calcium alginate dressing (Algisite®M) manufactured by Smith and Nephew Public Limited Company, London, United Kingdom; calcium sodium alginate dressing  made by ConvaTec Inc., Deeside, United Kingdom; foam with a polyurethane film layer dressing (Allevyn®) manufactured by Smith and Nephew Public Limited Company, London, United Kingdom; and foam with a hydrogel and polyurethane film layer dressing (Askina®) produced by B. Braun Hospicare Ltd., County Sligo, Ireland. Sodium chloride and calcium chloride dihydrate were analytically graded without further purification.The morphology of each dressing was assessed with a scanning electron microscope  with upper (50x), lower (50x), and cross-sectional (15x) images being recorded at different magnifications. The pore size of the dressing was measured using ImageJ® software and represented in a mean ± standard deviation.22H2O (0.0025 mol/L) were added to one litre of deionised water) represented a pseudo-wound exudate. The dressing was immersed in the test solution and then incubated at 37°C. At different periods, the dressing was removed and weighed. The experiments were performed in triplicate, and the weight increase was represented in a percentage and mean ± standard deviation.The absorption properties of the dressing were examined using BS EN 13726-1: 2002, Part 1: the aspects of absorbency, The dressing (2 cm × 2 cm) was immersed in the test solution for 30 minutes. After that, the dressing was removed, weighed, and incubated in an oven at 37°C. At different periods, the dressing was weighed. The experiments were performed in triplicate, and the dehydration rate was represented in a mean ± standard deviation .The water vapour transmission rate (WVTR) of the dressing was examined using BS EN 13726-2: 2002, Part 2: the moisture vapour transmission rate of permeable film dressings with slight modifications . The dreThe dispersion characteristics of the dressing were examined using BS EN 137262: 2002, Part 1: the aspects of absorbency, Section 3.6: dispersion characteristics with slight modifications . The dreμm, respectively. However, the number of pores of foam with a polyurethane film dressing was higher when compared with the other dressings. In addition, cell attachment, migration, and proliferation are an important process for the healing of a wound and an appropriate pore size range for these processes is 90–400 μm; cells cannot migrate, if pores are too small and cells cannot attach, if there is not enough surface area [Upper, lower, and cross-sectional images of the wound dressings are shown in ace area , 14. TheThis was the first study to demonstrate the absorption characteristics of a wound dressing during a 12-hour period. The absorption properties of the wound dressing are shown in The dehydration properties of the wound dressings are shown in The water vapour transmission rate (WVTR) of the wound dressings is shown in The dispersion characteristics of the wound dressings are shown in Calcium sodium alginate dressings demonstrate the highest quality among absorbent wound dressings. However, the integrity of alginate dressings should be taken into consideration and further research should be undertaken.