Gut microbiota is involved in male reproductive function: a review.

Globally, ~8%-12% of couples confront infertility issues, male-related issues being accountable for 50%. This review focuses on the influence of gut microbiota and their metabolites on the male reproductive system from five perspectives: sperm quality, testicular structure, sex hormones, sexual behavior, and probiotic supplementation. To improve sperm quality, gut microbiota can secrete metabolites by themselves or regulate host metabolites. Endotoxemia is a key factor in testicular structure damage that causes orchitis and disrupts the blood-testis barrier (BTB). In addition, the gut microbiota can regulate sex hormone levels by participating in the synthesis of sex hormone-related enzymes directly and participating in the enterohepatic circulation of sex hormones, and affect the hypothalamic-pituitary-testis (HPT) axis. They can also activate areas of the brain that control sexual arousal and behavior through metabolites. Probiotic supplementation can improve male reproductive function. Therefore, the gut microbiota may affect male reproductive function and behavior; however, further research is needed to better understand the mechanisms underlying microbiota-mediated male infertility.

Gut microbiota affects obesity susceptibility in mice through gut metabolites.

Introduction: It is well-known that different populations and animals, even experimental animals with the same rearing conditions, differ in their susceptibility to obesity. The disparity in gut microbiota could potentially account for the variation in susceptibility to obesity. However, the precise impact of gut microbiota on gut metabolites and its subsequent influence on susceptibility to obesity remains uncertain. Methods: In this study, we established obesity-prone (OP) and obesity-resistant (OR) mouse models by High Fat Diet (HFD). Fecal contents of cecum were examined using 16S rDNA sequencing and untargeted metabolomics. Correlation analysis and MIMOSA2 analysis were used to explore the association between gut microbiota and intestinal metabolites. Results: After a HFD, gut microbiota and gut metabolic profiles were significantly different between OP and OR mice. Gut microbiota after a HFD may lead to changes in eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), a variety of branched fatty acid esters of hydroxy fatty acids (FAHFAs) and a variety of phospholipids to promote obesity. The bacteria g_Akkermansia (Greengene ID: 175696) may contribute to the difference in obesity susceptibility through the synthesis of glycerophosphoryl diester phosphodiesterase (glpQ) to promote choline production and the synthesis of valyl-tRNA synthetase (VARS) which promotes L-Valine degradation. In addition, gut microbiota may affect obesity and obesity susceptibility through histidine metabolism, linoleic acid metabolism and protein digestion and absorption pathways.

Supplementing Glucose Intake Reverses the Inflammation Induced by a High-Fat Diet by Increasing the Expression of Siglec-E Ligands on Erythrocytes.

Siglec-9/E is a cell surface receptor expressed on immune cells and can be activated by sialoglycan ligands to play an immunosuppressive role. Our previous study showed that increasing the expression of Siglec-9 (the human paralog of mouse Siglec-E) ligands maintains functionally quiescent immune cells in the bloodstream, but the biological effects of Siglec-9 ligand alteration on atherogenesis were not further explored. In the present study, we demonstrated that the atherosclerosis risk factor ox-LDL or a high-fat diet could decrease the expression of Siglec-9/E ligands on erythrocytes. Increased expression of Siglec-E ligands on erythrocytes caused by dietary supplementation with glucose (20% glucose) had anti-inflammatory effects, and the mechanism was associated with glucose intake. In high-fat diet-fed apoE-/- mice, glucose supplementation decreased the area of atherosclerotic lesions and peripheral inflammation. These data suggested that increased systemic inflammation is attenuated by increasing the expression of Siglec-9/E ligands on erythrocytes. Therefore, Siglec-9/E ligands might be valuable targets for atherosclerosis therapy.

Assessment of Fetal Exposure and Elimination of Perfluoroalkyl and Polyfluoroalkyl Substances: New Evidence from Paired Serum, Placenta, and Meconium Samples.

Multiple pieces of evidence have shown that prenatal exposure to perfluoroalkyl and polyfluoroalkyl substances (PFASs) is closely related to adverse birth outcomes for infants. However, difficult access to human samples limits our understanding of PFASs transport and metabolism across the human placental barrier, as well as the accurate assessment of fetal PFASs exposure. Herein, we assess fetal exposure to 28 PFASs based on paired serum, placenta, and meconium samples. Overall, 21 PFASs were identified first to be exposed to the fetus prenatally and to be metabolized and excreted by the fetus. In meconium samples, 25 PFASs were detected, with perfluorooctane sulfonate and perfluorohexane sulfonic acid being the dominant congeners, suggesting the metabolism and excretion of PFASs through meconium. Perfluoroalkyl sulfonic acids might be more easily eliminated through the meconium than perfluorinated carboxylic acids. Importantly, based on molecular docking, MRP1, OATP2B1, ASCT1, and P-gp were identified as crucial transporters in the dynamic placental transfer of PFASs between the mother and the fetus. ATSC5p and PubchemFP679 were recognized as critical structural features that affect the metabolism and secretion of PFASs through meconium. With increasing carbon chain length, both the transplacental transfer efficiency and meconium excretion efficiency of PFASs showed a structure-dependent manner. This study reports, for the first time, that meconium, which is a noninvasive and stable biological matrix, can be strong evidence of prenatal PFASs exposure.

Butyrate alleviates renal fibrosis in CKD by regulating NLRP3-mediated pyroptosis via the STING/NF-κB/p65 pathway.

Chronic kidney disease (CKD) is a serious and irreversible disease primarily characterized by chronic inflammation and renal fibrosis. Recent studies have suggested that gut microbiota-related metabolites, particularly short-chain fatty acids (SCFAs) are significantly associated with kidney diseases. Notably, butyrate, a type of SCFAs, plays a crucial role in this correlation. However, the effect of butyrate on renal fibrosis in patients with CKD and its potential mechanisms remain unclear. In this study, we demonstrated that butyrate levels are reduced as CKD progresses using a CKD C57BL/6 mouse model established by a 0.2% adenine diet. Exogenous supplementation of butyrate effectively alleviated renal fibrosis and repressed the levels of proteins associated with NLRP3-mediated pyroptosis (NLRP3, IL-1ß, caspase-1, and GSDMD). Additionally, we conducted an in vitro experiment using HK-2 cells, which also confirmed that the elevated levels of NLRP3-mediated pyroptosis proteins in TGF-ß1-stimulated HK-2 cells are reversed by butyrate intervention. Further, butyrate mitigated the activity of the STING/NF-κB/p65 pathway, and STING overexpression impaired the protective function of butyrate in CKD. Hence, we suggest that butyrate may have a renoprotective role in CKD, alleviating renal fibrosis possibly by regulating NLRP3-mediated pyroptosis via the STING/NF-κB/p65 pathway.

Fabrication and optimization of paper chips from calcinated Fe-MOFs for rapid and in situ visual detection of tetracyclines in water environments.

Antibiotics such as tetracyclines (TCs) have become a major threat to ecosystem safety and human health, as their abuse has caused the occurrence and proliferation of antibiotic-resistant bacteria and genes. Currently, there is still a lack of convenient in situ methods for the detection and monitoring of TC pollution in actual water systems. This research reports a paper chip based on the complexation of iron-based metal organic frameworks (Fe-MOFs) and TCs for rapid and in situ visual detection of representative oxytetracycline (OTC) pollution in water environments. The optimized complexation sample NH2-MIL-101(Fe)- 350 obtained by calcination at 350 °C exhibited the highest catalytic activity and was then used for paper chip fabrication by printing and surface modification. Notably, the paper chip demonstrated a detection limit as low as 17.11 nmol L-1 and good practicability in reclaimed water, aquaculture wastewater, and surface water systems, with OTC recovery rates of 90.6-111.4%. More importantly, the presence of dissolved oxygen (9.13-12.7 mg L-1), chemical oxygen demand (0.52-12.1 mg L-1), humic acid (< 10 mg L-1), Ca2+, Cl-, and HPO42- (< 0.5 mol L-1) had negligible interference on the detection of TCs by the paper chip. Therefore, this work has developed a promising method for rapid and in situ visual monitoring of TC pollution in actual water environments.

Source-Free Progressive Graph Learning for Open-Set Domain Adaptation.

Open-set domain adaptation (OSDA) aims to transfer knowledge from a label-rich source domain to a label-scarce target domain while addressing disturbances from irrelevant target classes not present in the source data. However, most OSDA approaches are limited due to the lack of essential theoretical analysis of generalization bound, reliance on the coexistence of source and target data during adaptation, and failure to accurately estimate model predictions' uncertainty. To address these limitations, the Progressive Graph Learning (PGL) framework is proposed. PGL decomposes the target hypothesis space into shared and unknown subspaces and progressively pseudo-labels the most confident known samples from the target domain for hypothesis adaptation. PGL guarantees a tight upper bound of the target error by integrating a graph neural network with episodic training and leveraging adversarial learning to close the gap between the source and target distributions. The proposed approach also tackles a more realistic source-free open-set domain adaptation (SF-OSDA) setting that makes no assumptions about the coexistence of source and target domains. In a two-stage framework, the SF-PGL model' uniformly selects the most confident target instances from each category at a fixed ratio, and the confidence thresholds in each class weigh the classification loss in the adaptation step. The proposed methods are evaluated on benchmark image classification and action recognition datasets, where they demonstrate superiority and flexibility in recognizing both shared and unknown categories. Additionally, balanced pseudo-labeling plays a significant role in improving calibration, making the trained model less prone to over- or under-confident predictions on the target data.

Pretreatment of poplar with eco-friendly levulinic acid to achieve efficient utilization of biomass.

Organic acid pretreatment is an effective method for green separation of lignocellulosic biomass. However, repolymerization of lignin seriously affects the dissolution of hemicellulose and the conversion of cellulose during organic acid pretreatment. Therefore, a new organic acid pretreatment, levulinic acid (Lev) pretreatment, was studied for the deconstruction of lignocellulosic biomass without adding additional additives. The preferred separation of hemicellulose was realized at Lev concentration 7.0%, temperature 170 °C, and time 100 min. The separation of hemicellulose increased from 58.38% to 82.05% compared with acetic acid pretreatment. It was found that the repolymerization of lignin was effectively inhibited in the efficient separation of hemicellulose. This was attributed to the fact that γ-valerolactone (GVL) is a good green scavenger of lignin fragments. The lignin fragments in the hydrolysate were effectively dissolved. The results provided theoretical support for creating green and efficient organic acid pretreatment and effectively inhibiting lignin repolymerization.

Polydopamine-Reinforced Hemicellulose-Based Multifunctional Flexible Hydrogels for Human Movement Sensing and Self-Powered Transdermal Drug Delivery.

The preparation of bio-based hydrogels with excellent mechanical properties, stable electrochemical properties, and self-adhesive properties remains a challenge. In this study, nano-polydopamine-reinforced hemicellulose-based hydrogels with typical multistage pore structures were prepared. The nanocomposite hydrogels exhibit stable mechanical properties and show no significant crushing phenomenon after 1000 cycles of cyclic compression. Its ultimate tensile strain was 101%, which is significantly higher than that of native skin. The shear adhesion strength of the hydrogel to skin tissue reaches 7.52 kPa, which is better than fibrin glue (Greenplast) (5 kPa), and the excellent adhesion property prolongs the service time of the hydrogel in biomedicine applications. The impedance of the hydrogel was reduced and the electrical conductivity was increased with the addition of nano-polydopamine. The prepared nanocomposite hydrogel can detect various body movements (even throat vibrations) in real time as a motion sensor while being able to rapidly load cationic drugs and facilitate transdermal introduction of electrically stimulated drug ions as a drug patch. It provides theoretical support for the fabrication of hemicellulose-based hydrogels with excellent properties through molecular design and nanoparticle reinforcement. This has important implications for the development of next-generation flexible materials suitable for health monitoring and self-administration.

Bromophenol Induced Multiple Stress Responses in Rice Plants: Impact of Doses and Congener Structures.

Bromophenols (BPs) have both natural and artificial sources in the environment and are frequently detected in plants. Herein, the ubiquitous 2,4,6-TriBP was hydroponically exposed to rice seedlings at two concentrations (0.2 and 2.0 mg/L) to characterize the dose-dependent abiotic stress responses of rice plants to BPs. The 2,4,6-TriBP induced oxidative damage to rice roots and subsequently inhibited plant transpiration and growth at the end of exposure in both concentrations. Moreover, the gene expression of OsUGT72B1 and the activity of glycosyltransferases of exposed rice roots were 2.36-to-4.41-fold and 1.23-to-1.72-fold higher than that of the blank controls after 24 h, following the formation of glycoconjugates in response to 2,4,6-TriBP exposure. It was notable that the glycosylation rates also showed a dose-effect relationship in rice roots. One and six glycoconjugates of 2,4,6-TriBP were detected in 0.2 and 2.0 mg/L exposure groups, respectively. Considering the detected species of glycoconjugates for four other types of BPs, the numbers of bromine atoms were found to dramatically affect their glycosylation process in rice plants. These results improve our fundamental understanding of the impact of congener structures and exposure concentrations of organic contaminants on the glycosylation process in response to phytotoxicity.

Enhancement of separation selectivity of hemicellulose from bamboo using freeze-thaw-assisted p-toluenesulfonic acid treatment at low acid concentration and high temperature.

The cellulose-rich residual solids are obtained with p-toluenesulfonic acid (p-TsOH) treatment. However, better fractionation of hemicellulose and separation is difficult to obtain during treatment. This study aims at investigating the separation selectivity of bamboo hemicellulose using freeze-thaw-assisted p-TsOH (F/p-TsOH) treatment. The desired separation effect was achieved at freezing temperature -40 °C, freezing time 20 h, p-TsOH concentration 3.0 %, treatment temperature 130 °C and time 80 min. 93.26 % hemicellulose separation was found, which was 32.88 % higher than that of conventional p-TsOH treatment. Furthermore, the separation yield of lignin decreased significantly from 69.29 % to 13.98 %. The distinct lignin characteristic absorption peaks were found, while that of hemicellulose was difficult to observe. The fiber crystallinity index increased from 50.42 to 56.55 %. Furthermore, greater selectivity for hemicellulose separation was achieved. The results provide a new research thinking for efficient fractionation of lignocellulosic biomass by organic acid treatment.

Percutaneous absorption and exposure risk assessment of organophosphate esters in children's toys.

The percutaneous penetration and exposure risk of organophosphate esters (OPEs) from children's toys remains largely unknown. Percutaneous penetration of OPEs was evaluated by EPISkin™ model. Chlorinated OPEs (Cl-OPEs) and alkyl OPEs, except tris(2-ethylhexyl) phosphate, exhibited a fast absorption rate and good dermal penetration ability with cumulative absorptions of 57.6-127 % of dosed OPEs. Cumulative absorptions of OPEs through skin cells were inversely associated with their molecular weight and log octanol-water partition coefficient. Additionally, a quantitative structure-activity relationship model indicated that topological charge and steric features of OPEs were closely related to the transdermal permeability of these chemicals. With the clarification of the factors affecting the transdermal penetration of OPEs, the level and exposure risk of OPEs in actual toys were studied. The summation of 18 OPE concentrations in 199 toy samples collected from China ranged from 6.82 to 228,254 ng/g, of which Cl-OPEs presented the highest concentration. Concentrations of OPEs in toys exhibited clear type differences. Daily exposure to OPEs via dermal, hand-to-mouth contact, and mouthing was evaluated, and dermal contact was a significant route for children's exposure to OPEs. Hazard quotients for noncarcinogenic risk assessment were below 1, indicating that the health risk of OPEs via toys was relatively low.

Kinetics of Lignin Separation during the Atmospheric Fractionation of Bagasse with p-Toluenesulfonic Acid.

As a green and efficient component separation technology, organic acid pretreatment has been widely studied in biomass refining. In particular, the efficient separation of lignin by p-toluenesulfonic acid (p-TsOH) pretreatment has been achieved. In this study, the mechanism of the atmospheric separation of bagasse lignin with p-TsOH was investigated. The separation kinetics of lignin was analyzed. A non-simple linear relationship was found between the separation yield of lignin and the concentration of p-TsOH, the temperature and the stirring speed. The shrinking nucleus model for the separation of lignin was established based on the introduction of mass transfer and diffusion factors. A general model of the total delignification rate was obtained. The results showed that the process of lignin separation occurred into two phases, i.e., a fast stage and a slow stage. The results provide a theoretical basis for the efficient separation of lignin by p-TsOH pretreatment.

Exposure to short-, medium-, and long-chain chlorinated paraffins for infant via cow infant formula, goat infant formula and baby food.

Dietary exposure is an important pathway for many pollutants from external exposure to human beings. In this study, we investigated the exposure to short-chain chlorinated paraffins (SCCPs), medium-chain chlorinated paraffins (MCCPs) and long-chain chlorinated paraffins (LCCPs), which are a class of industrial compounds that are of significant concern, in different infant foods (cow infant formula, goat infant formula and baby food are collectively called infant food in this study) in Chinese market. The concentrations of ∑SCCPs, ∑MCCPs and ∑LCCPs in infant foods were in the ranges of 6.22-273 ng/g, 13.1-2020 ng/g and 0.80-1280 ng/g, respectively. Especially, for the first time, we found that the proportion of ∑LCCPs (22.0%) in goat infant formula is almost equivalent to that of ∑SCCPs (25.0%), implying that LCCPs should also be further concerned since the related information is very scarce. There were differences between CP profiles among imported cow infant formula and Chinese cow infant formula due to the different sources of CPs to the infant formula. Imported infant foods were characterized by higher proportion of SCCPs, while Chinese infant foods were characterized by higher proportion on LCCPs. Margin of exposure results demonstrated that there was no significant health concern for the infant, but that large variation of CP concentrations and excessive feeding in practice may cause potential health threats to the infant. LCCPs were detected in all infant food samples, and to our knowledge, this is the first report of LCCPs in cow infant formula, goat infant formula and baby food. This study could provide important data of infant exposure to CPs, especially, LCCPs.

Characteristics of intestinal microbiota in C57BL/6 mice with non-alcoholic fatty liver induced by high-fat diet.

Introduction: As a representation of the gut microbiota, fecal and cecal samples are most often used in human and animal studies, including in non-alcoholic fatty liver disease (NAFLD) research. However, due to the regional structure and function of intestinal microbiota, whether it is representative to use cecal or fecal contents to study intestinal microbiota in the study of NAFLD remains to be shown. Methods: The NAFLD mouse model was established by high-fat diet induction, and the contents of the jejunum, ileum, cecum, and colon (formed fecal balls) were collected for 16S rRNA gene analysis. Results: Compared with normal mice, the diversity and the relative abundance of major bacteria and functional genes of the ileum, cecum and colon were significantly changed, but not in the jejunum. In NAFLD mice, the variation characteristics of microbiota in the cecum and colon (feces) were similar. However, the variation characteristics of intestinal microbiota in the ileum and large intestine segments (cecum and colon) were quite different. Discussion: Therefore, the study results of cecal and colonic (fecal) microbiota cannot completely represent the results of jejunal and ileal microbiota.

Trustworthy faces make people more risk-tolerant: The effect of facial trustworthiness on risk decision-making under gain and loss conditions.

People can judge a stranger's trustworthiness at first glance solely based on facial appearance. Moreover, the trust behaviors people exhibit toward strangers differ depending on perceived trustworthiness from faces. Research has found that people have different risk preferences according to the gain or loss frame. Therefore, we hypothesized that the risk decisions are differently affected by facial trustworthiness in different frames. We conducted three experiments in which we asked participants to make risk decisions in the gain frame or loss frame. The results revealed that facial trustworthiness had a significant effect on risk decisions in the gain frame. However, the effect was attenuated in the loss frame. These results suggest that people are more willing to take risks in the gain frame if individuals look more trustworthy than those who look untrustworthy.

High efficiency and clean separation of eucalyptus components by glycolic acid pretreatment.

Glycolic acid has chemical properties similar to those of formic acid. Therefore, similar to formic acid pretreatment, glycolic acid pretreatment has the separation effect of hemicellulose. In this study, eucalyptus hemicellulose was effectively separated by glycolic acid pretreatment. The effects of glycolic acid concentration, temperature and time on the separation of cellulose, hemicellulose and lignin were investigated. The optimum conditions were acid concentration 5.40%, temperature 140 °C, time 3.0 h. The highest yield of xylose was 56.72%. The recovery rate of glycolic acid was 91%. Compared to formic acid, the yield of xylose increased to 10.33% while that of lignin decreased to 11.08%. It showed high selectivity for hemicellulose separation, yielding 65.48% hemicellulose with 72.08% purity. The depolymerization and repolymerization of lignin were inhibited. The integrity of the cellulose structure was preserved. It provides theoretical support for the fractional separation and high-value transformation of lignocellulosic biomass.

Effect of organosolv extraction on the structure and antioxidant activity of eucalyptus kraft lignin.

In this study, three lignin fractions F1, F2, and F3 were obtained from eucalyptus kraft lignin (EKL) by solvent extraction with ethyl acetate, acetone, and acetone/water. The antioxidant activity of these lignin fractions were measured and evaluated by using the DPPH radical scavenging activity, ABTS radical cation scavenging activity and ferric reducing antioxidant power analysis. These lignin fractions were also characterized by applying Gel permeation chromatography, Fourier transform infrared, 31P NMR and 2D HSQC NMR techniques. The three different lignin fractions had rather different average molecular sizes, as well as different phenolic and methoxy functional contents. The ethyl acetate fraction (F1) with the lowest average molecular weight (2342 g/mol) and the highest phenolic hydroxyl content (4.2457 mmol/g) and methoxy groups (6.2714 mmol/g) showed high homogeneity and the highest antioxidant activity. Its DPPH scavenging activity, ABTS+ scavenging activity, and ferric reducing the antioxidant power were 68.67%, 75.57%, and 91.89 µmol/g, respectively. Moreover, the antioxidant activity of F1 and F2 was found to be higher than that of butylated hydroxytoluene. Therefore, solvent extraction was shown to be an effective way to separate lignin fractions with high homogeneity, high antioxidant activity, which could lead to application of lignin with higher value.

Seasonal distribution and ecological risk of phthalate esters in surface water and marine organisms of the Bohai Sea.

The spatiotemporal variability and ecological risks related to 16 phthalate esters (PAEs) were investigated in surface water and marine organisms of the Bohai Sea. The average PAE concentrations in the surface water were 8.02, 4.53, and 3.16 µg L-1 in spring, summer, and winter, respectively. Additionally, suspended particle matter was positive related to PAE content in seawater in spring and winter. The predominant PAEs in both water and biota were dimethyl phthalate (DMP), di-butyl phthalate (DBP), di-isobutyl phthalate (DIBP), and diethylhexyl-phthalate (DEHP). Because they do not exhibit long-distance migratory behavior, Chaeturichthys hexanema, Cynoglossus lighti, and Loligo japonica were good candidate indicator organisms for PAE pollution in Bohai Sea. The risk quotient method revealed that DIBP, DBP, and DEHP posed relatively greater risks to the aquatic system. This research establishes baseline data from which future management strategies to control PAEs in the Bohai Sea can be developed.

Temporal trends of novel brominated flame retardants in mollusks from the Chinese Bohai Sea (2011-2018).

Novel brominated flame retardants (NBFRs) have emerged as an alternative to traditional brominated flame retardants (BFRs); however, they may pose risks to the environment and human health. To investigate the occurrence, temporal trends, and human exposure of seven typical NBFRs (∑7 NBFRs), seven species of mollusks (n = 329) were collected from coastal cities in the Chinese Bohai Sea area from 2011 to 2018. The ∑7 NBFRs ranged from 1.52 to 154 ng/g dry weight (dw) (mean: 14.9 ± 21.21 ng/g dw), higher than in other areas worldwide. Decabromodiphenylethane (DBDPE) was the main contaminant, contributing to 33% of the NBFRs. Temporal trends indicate that the DBDPE and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) concentrations in mollusks increased significantly (P < 0.05) at rates of about 26% and 5.4%, respectively. This suggests that these NBFRs are continuously released into the environment of the Bohai Sea area. The higher NBFR concentrations in the southern sampling sites relative to the northern sampling sites were consistent with the spatial distribution of the NBFR industry in the Bohai Rim Economic Circle. Chlamys farreri possessed the highest ∑7 NBFR concentrations compared with the other species, while the lowest concentrations were found in Neverita didyma and Rapana venosa, suggesting interspecific differences in bioaccumulation. The estimated daily intake of NBFRs was low, and as the main contaminant, DBDPE was unlikely to pose significant human health risks. Overall, this is the first study to comprehensively assess the occurrence, spatial distribution, and temporal trends of NBFRs in mollusks.