A combination of microbial electrolysis cells and bioaugmentation can effectively treat synthetic wastewater containing polycyclic aromatic hydrocarbon.

The anaerobic biodegradation of polycyclic aromatic hydrocarbons (PAHs) is challenging due to its toxic effect on the microbes. Microbial electrolysis cells (MECs), with their excellent characteristics of anodic and cathodic biofilms, can be a viable way to enhance the biodegradation of PAHs. This work assessed different cathode materials (carbon brush and nickel foam) combined with bioaugmentation on typical PAHs-naphthalene biodegradation and analyzed the inhibition amendment mechanism of microbial biofilms in MECs. Compared with the control, the degradation efficiency of naphthalene with the nickel foam cathode supplied with bioaugmentation dosage realized a maximum removal rate of 94.5 ± 3.2%. The highest daily recovered methane yield (227 ± 2 mL/gCOD) was also found in the nickel foam cathode supplied with bioaugmentation. Moreover, the microbial analysis demonstrated the significant switch of predominant PAH-degrading microorganisms from Pseudomonas in control to norank_f_Prolixibacteraceae in MECs. Furthermore, hydrogentrophic methanogenesis prevailed in MEC reactors, which is responsible for methane production. This study proved that MEC combined with bioaugmentation could effectively alleviate the inhibition of PAH, with the nickel foam cathode obtaining the fastest recovery rate in terms of methane yield.

Association between social withdrawal and suicidal ideation in patients with major depressive disorder: The mediational role of emotional symptoms.

BACKGROUND: The study was designed to investigate the associations between social withdrawal, emotional symptoms, and suicide ideation in patients with major depressive disorder (MDD). METHODS: This cross-sectional study included 2678 MDD patients from the National Survey on Symptomatology of Depression (NSSD). Differences in the sociodemographic factors, clinical characteristics, suicide ideation, and emotional symptoms were compared in patients with different frequencies of social withdrawal. Pearson correlation, multiple linear regression analysis, and mediation analysis were employed to assess the contribution of social withdrawal to suicide ideation. RESULTS: MDD patients with a higher frequency of social withdrawal were prone to have a higher frequency of suicide ideation (p for trend <0.001) and history of suicide behavior (p for trend <0.001). Multiple linear regression analysis showed that there was a dose-response relationship between social withdrawal and suicide ideation in MDD patients, but this association became insignificant after adjusting for emotional symptoms. Mediation analysis suggested that all of the emotional symptoms had significant mediating effects on the association between social withdrawal and suicide ideation in MDD patients (p < 0.05). The magnitude of mediation varied between 4.3 % and 64.3 %, with the largest mediating effect in the feeling of despair (64.3 %), helplessness (41.2 %), and loneliness (40.0 %). CONCLUSION: Our study provides evidence that social withdrawal was a common clinical presentation and it may increase the risk for suicide through emotional symptoms in MDD patients. LIMITATIONS: Causal conclusions could not be drawn between social withdrawal, emotional symptoms, and suicide ideation because of the cross-sectional design of the study.

Separation of spring viraemia of carp virus from large-volume samples using immunomagnetic beads.

A method for separation of spring viraemia of carp virus (SVCV) from large-volume samples using immunomagnetic beads (IMBs) coated with a polyclonal antibody against SVCV was developed. The optimum amount of IMBs was 2 mg in 100 mL. After IMB treatment, the detection limit of SVCV in reverse transcription quantitative PCR (RT-qPCR) was 103 times the 50% tissue culture infectious dose per mL in 100-mL samples. The concentration of viral RNA extracted from SVCV that had been separated using IMBs was 5.18 × 103-fold higher than that of the unseparated SVCV. When fish samples were tested, the concordance rates of the IMBs/RT-qPCR and RT-qPCR were 100% and 67.5%, respectively.

The influence of home isolation during COVID-19 on the physical fitness development of college students: a study utilizing repeated measures analysis of variance.

BACKGROUND: Research on the impact of COVID-19-induced home isolation on the physical fitness of college students is limited. This study aims to compare and analyze the physical fitness test scores of college students in two groups: those who experienced home isolation and those who did not, over three consecutive years after enrolment, to investigate the effects of home isolation on the physical fitness development of Chinese college students. METHODS: This comparative study included two longitudinal surveys conducted among medical college students. The participants were divided into an experimental group and a control group. The physical fitness indicators measured included body mass index (BMI), vital capacity (VC), 50-metre run, sit-and-reach, standing long jump, 1000/800-metre runs (males/females), pull-ups (males) and sit-ups (females). Repeated measures analysis of variance (ANOVA) was employed, and the Greenhouse-Geisser correction was applied when Mauchly's assumption of sphericity was violated. Pairwise comparisons were conducted using the Bonferroni method. RESULTS: A total of 6580 students participated in the study, with 3360 students (1490 males, 1870 females) enrolled in 2019 as the experimental group and 3220 students (1326 males, 1894 females) enrolled in 2017 as the control group. All participants completed the physical fitness tests for three consecutive years. The results showed that the experimental group exhibited decreased performance in the 1000-metre and 800-metre runs, and improved performance in the sit-and-reach test. After the end of home isolation, there was an improvement in the performance of the 1000-metre run and 800-metre run, while no significant differences were observed in the trends of the other tested indicators. CONCLUSION: The findings of this study indicate that the home isolation environment during COVID-19 had a significant impact on the physical fitness of college students, specifically in terms of endurance and flexibility qualities, as well as male BMI. To better prepare for future public health emergencies and mitigate the effects of isolation, teaching students endurance exercises that can be performed at home should be prioritized. Furthermore, physical education programs should be improved to enhance student flexibility.

Purification of Galacto-oligosaccharide (GOS) by fermentation with Kluyveromyces lactis and Interaction between GOS and casein under simulated acidic fermentation conditions.

In the enzymatic synthesis of galacto-oligosaccharide (GOS), the primary by-products include glucose, galactose and unreacted lactose. This This study was aimed to provide a method to to purify GOS by yeat fermentation and explore the interaction between GOS and CAS with a view for expanding the prospects of GOS application in the food industry. The crude GOS(25.70 g/L) was purified in this study using the fermentation method with Kluyveromyces lactis CICC 1773. Optimal conditions for purification with the yeast were 75 g/L of the yeast inoculation rate and 50 g/L of the initial crude GOS concentration for 12 h of incubation. After removing ethanol produced by yeast by low-temperature distillation, GOS content could reach 90.17%. A study of the interaction between GOS and casein (CAS) in a simulated acidic fermentation system by D-(+)-gluconic acid δ-lactone (GDL) showed that the GOS/CAS complexes with higher GOS concentrations, e.g., 4% and 6% (w/v), was more viscoelastic with higher water-holding capacity, but decreased hardness, elasticity, and cohesiveness at 6% (w/v) of GOS. The addition of GOS to CAS suspension significantly caused (p<0.05) decreased particle sizes of the formed GOS/CAS complexes, and the suspension system became more stable. FT-IR spectra confirmed the existence of different forms of molecular interactions between CAS and GOS, e.g., hydrogen bonding and hydrophobic interaction, and the change of secondary structure after CAS binding to GOS.

Assessment of potential ecological risk based on the vertical characteristics of potential toxic elements in sediments from a high-density cage culture reservoir in China.

The pollution of sediments around Lu Ban Island is a serious environmental issue that is threatening human health. The concentration of As, Cd, Cu, Cr, Hg, Ni, Pb, and Zn at 73 layer points were investigated, vertical distribution characteristics, correlation among potential toxic elements and potential ecological risks of sediments at different depth were analyzed. The following results were obtained, (1) the hypothesis that there was a linear relationship between concentration of potential toxic elements and the reciprocal of deep was reasonable. Based on hypothesis, the ultimate value of concentration by making depth go to infinity was regarded as the background concentration. The background concentration of As, Cd, Cu, Cr, Hg, Ni, Pb, and Zn are respectively 4.94 mg/kg, 0.20 mg/kg, 15.48 mg/kg, 58.41 mg/kg, 0.062 mg/kg, 26.96 mg/kg, 20.29 mg/kg, and 53.31 mg/kg. (2) But correlation between Ni and As was relatively weak, high degree of correlation among other potential toxic elements were found. Based on their correlation, eight potential toxic elements were classified into three groups. First group included Ni and Cr, mainly releasing by coal burning; Cu, Pb, Zn, Hg, and Cd were grouped together, possibly due to their shared source of fish cage culture; Arsenic with relatively weak correlation with other potential toxic elements was classified as a separate class, which was usually one important mineral resource associated with phosphate. (3) Potential ecological risk index (PERI) of sediment above - 0.40 m belonged to moderate risk, the PERI of sediment in - 0.10 m, - 0.20 m, and - 0.40 m were 289.06, 254.33, and 201.44, respectively. Sediment below - 0.40 m belonged to low risk with average PERI value 112.82, with no significant changes in PERI values. The order of contribution to PERI was Hg > Cd > As > Cu > Pb > Ni > Cr > Zn. (4) According to result of cluster analysis and potential ecological risk, the potential ecological risk of sediment above - 0.40 m mainly contributed by potential toxic elements of Cu, Cd, Hg, Pb, and Zn sharing source of fish cage culture.

Single-cell protein activity analysis reveals a novel subpopulation of chondrocytes and the corresponding key master regulator proteins associated with anti-senescence and OA progression.

Background: Osteoarthritis (OA) is a prevalent senescence-related disease with substantial joint pain, loss of joint function, and cartilage degeneration. Because of the paucity of single-cell studies of OA and the gene dropout problem of single-cell RNA sequencing, it is difficult to acquire an in-depth understanding of the molecular characteristics of various chondrocyte clusters. Methods: Here, we aimed to provide new insights into chondrocyte senescence and a rationale for the development of effective intervention strategies for OA by using published single-cell RNA-sequencing data sets and the metaVIPER algorithm (Virtual Inference of Protein activity by Enriched Regulon). This algorithm was employed to present a proteome catalog of 62,449 chondrocytes from the cartilage of healthy individuals and OA patients at single-cell resolution. Furthermore, histopathologic analysis was carried out in cartilage samples from clinical patients and experimental mouse models of OA to validate above results. Results: We identified 16 protein-activity-based chondrocyte clusters as well as the underlying master regulators in each cluster. By assessing the enrichment score of each cluster in bulk RNA-sequencing data, followed by gene-set variation analysis, we preliminarily identified a novel subpopulation of chondrocytes (cluster 3). This clinically relevant cluster was predicted to be the main chondrocyte cluster responsible for maintaining cellular homeostasis and anti-senescence. Specifically, we uncovered a set of the key leading-edge proteins of cluster 3 by validating the robustness of the above results using another human chondrocyte single-cell RNA-sequencing data set, consisting of 24,675 chondrocytes. Furthermore, cartilage samples from clinical patients and experimental mouse models of OA were used to evaluate the expression patterns of these leading-edge proteins, and the results indicated that NDRG2, TSPYL2, JMJD6 and HMGB2 are closely associated with OA pathogenesis and might play critical roles in modulating cellular homeostasis and anti-senescence in chondrocytes. Conclusion: Our study revealed a novel subpopulation of chondrocytes that are critical for anti-progression of OA and the corresponding master regulator proteins, which might serve as therapeutic targets in OA.

How does multiple substrate binding lead to substrate inhibition of CYP2D6 metabolizing dextromethorphan? A theoretical study.

CYP2D6 is one of the most important metalloenzymes involved in the biodegradation of many drug molecules in the human body. It has been found that multiple substrate binding can lead to substrate inhibition of CYP2D6 metabolizing dextromethorphan (DM), but the corresponding theoretical mechanism is rarely reported. Therefore, we chose DM as the probe and performed molecular dynamics simulations and quantum mechanical calculations on CYP2D6-DM systems to investigate the mechanism of how the multiple substrate binding leads to the substrate inhibition of CYP2D6 metabolizing substrates. According to our results, three gate residues (Arg221, Val374, and Phe483) for the catalytic pocket are determined. We also found that the multiple substrate binding can lead to substrate inhibition by reducing the stability of CYP2D6 binding DM and increasing the reactive activation energy of the rate-determining step. Our findings would help to understand the substrate inhibition of CYP2D6 metabolizing the DM and enrich the knowledge of the drug-drug interactions for the cytochrome P450 superfamily.

Screening new breeding japonica rice varieties by rice quality, three processing characteristics, and odor characteristics.

Rice's yield, cooking, and sensory quality are primary considerations in selecting new breeding rice varieties, which are determined by the rice eating quality such as processing and flavor characteristics. Thus, in this study, to advance the breed of new superior japonica rice varieties, the differences in the rice quality, processing characteristics, and flavor characteristics between 12 newly-bred varieties (H2-36, H2-42, H2-53, H2-59, H2-63, H2-73, H2-74, H2-79, H2-81, H2-82, H2-89, and H2-91) and 1 commercial variety (Kenyu38) were analyzed. The results indicated that H2-42 has a reasonable length-to-width ratio (1.51), high rice yield, good color, reasonable amylose, protein content, excellent water existence index, accessible storage, and the highest taste value. Electronic nose results showed significant differences in aldehydes, ketones, and alcohols among 13 rice varieties. Aroma analysis results showed that H2-42 had the highest n-hexanal (14.63 µg/kg), (E,E)-2,4-nonadienal (37.24 µg/kg), nonanal (19.93 µg/kg), and decanal (4.81 µg/kg); those were important aroma components in cooked rice. The Pearson correlation analysis showed that hardness, springiness, cohesiveness, trough viscosity, peak time, and pasting temperature were the crucial factors that affected rice quality. According to partial least squares regression analysis, total color change, final viscosity, setback, (E)-2-heptenal, and 2-methyl-undecanol were the most important factors that distinguished the rice quality. In conclusion, H2-42 rice was better apparent quality, processing characteristics, and aroma compounds. Therefore, H2-42 has the potential for identification and promotion. PRACTICAL APPLICATION: The results from this study will provide data support for the cultivation, application, and quality improvement of high-quality rice varieties. In addition, it gives new ideas and methods for studying rice eating quality.

The influence of NOS1AP gene polymorphisms and childhood abuse on antisocial personality disorder in Chinese male violent inmates.

Antisocial personality disorder (ASPD) is a common behavioral pattern that causes sufferers to ignore or violate the rights of others. Though its cause is still unclear, previous studies have shown that childhood maltreatment is closely related to ASPD. The NOS1AP gene is associated with various neuropsychiatric diseases, but a linkage between it and ASPD has not yet been discovered. This study recruited ASPD and non-ASPD male subjects who had committed violent crimes from a prison in Nanjing, China. By comparing the two groups' genotypes, allele frequencies, and histories of childhood abuse, we explored the interaction between the NOS1AP gene and childhood maltreatment on the pathogenesis of ASPD. The results showed that polymorphism rs945713 in the NOS1AP gene was associated with ASPD and furthermore that this SNP may be involved in regulating the effect of childhood abuse on ASPD. This study found that childhood trauma increases the risk of ASPD in violent adult male inmates; for prisoners with ASPD, it is critical to pay attention to their childhood trauma and take early psychological intervention.

Exploration of the Implementation of Carbon Neutralization in the Field of Natural Resources under the Background of Sustainable Development-An Overview.

On 15 March 2021, Chinese President Xi Jinping pointed out that "achieving carbon peak and carbon neutrality is a broad and profound economic and social systemic change" and called for "putting energy and resources conservation in the first place". Natural resources are the material basis, space carrier and energy source of high-quality development. The source of carbon emissions is resource utilization, and carbon reduction and removal also depend on resources. The improvement of carbon sink capacity is inseparable from natural resources. To achieve the goal of "double carbon", it is necessary to consolidate the carbon sink capacity of the ecosystem, as well as enhancing its carbon sink increment. Among natural resources, forest carbon sinks, soil carbon sinks and karst carbon sinks have significant emission reduction potential and cost advantages, representing important means to deal with climate change. This paper reviews the relevant research results at home and abroad, summarizes the carbon sink estimation, carbon sink potential, carbon sink influencing factors, ecological compensation mechanism and other aspects, analyzes the path selection of establishing carbon sink green development, and puts forward corresponding policies and suggestions, providing a theoretical reference for the achievement of the carbon neutrality goal in the field of natural resources in China.

Antagonistic Effect of Trichoderma longibrachiatum (TL6 and TL13) on Fusarium solani and Fusarium avenaceum Causing Root Rot on Snow Pea Plants.

Snow pea root rot in China is caused by Fusarium solani (FSH) and Fusarium avenaceum (FAH), which affect snow pea production. The chemical control methods used against FSH and FAH are toxic to the environment and resistance may be developed in persistence applications. Therefore, an alternative approach is needed to control these pathogens. This study focuses on Trichoderma longibrachiatum strains (TL6 and TL13), mycoparasitic mechanisms of FSH and FAH, as well as growth-promoting potentials on snow pea seedlings under FSH and FAH stress at the physiological, biochemical, and molecular levels. The average inhibitory rates of TL6 against FSH and FAH were 54.58% and 69.16%, respectively, on day 7. Similarly, TL13 average inhibitory rates against FSH and FAH were 59.06% and 71.27%, respectively, on day 7. The combined TL13 and TL6 with FSH and FAH reduced disease severity by 86.6, 81.6, 57.60, and 60.90%, respectively, in comparison to the controls. The snow pea plants inoculated with FSH and FAH without TL6 and TL13 increased malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents in the leaves by 64.8, 66.0, 64.4 and 65.9%, respectively, compared to the control. However, the combined FSH and FAH with TL6 and TL13 decreased the MDA and H2O2 content by 75.6, 76.8, 70.0, and 76.4%, respectively, in comparison to the controls. In addition, the combined TL6 + FSH and TL6 + FAH increased the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) by 60.5, 64.7, and 60.3%, respectively, and 60.0, 64.9, and 56.6%, respectively, compared to the controls. Again, compared to the controls, the combined TL13 + FSH and TL13 + FAH increased the activity of SOD, POD, and CAT by 69.7, 68.6, and 65.6%, respectively, and 70.10, 69.5, and 65.8%, respectively. Our results suggest that the pretreatment of snow pea seeds with TL6 and TL13 increases snow pea seedling growth, controls FSH and FAH root rot, increases antioxidant enzyme activity, and activates plant defense mechanisms. The TL13 strain had the greatest performance in terms of pathogen inhibition and snow pea growth promotion compared to the TL6 strain.

Breast metastasis of cervical cancer: A case report and systematic literature review.

It has been reported that extramammary malignant tumors metastasize to the breast, but cervical cancer metastasis to the breast is very rare. At present, there are only dozens of reports about cervical cancer metastasis to breast in the world. It is difficult to distinguish between primary breast cancer and metastatic breast cancer. We report a 44-year-old woman who underwent surgery, chemotherapy, and radiotherapy for cervical cancer 5 years ago. Then, she was hospitalized for finding a left breast mass measured 2.9 × 2.7 cm in chest CT. Pathological examination combined with immunohistochemical staining showed that the mass came from the cervix. Then, the patient received systematic chemotherapy and interstitial brachytherapy (IB) for the breast mass and got a great result. Cervical cancer rarely metastasizes to the breast. In this case, we confirmed the diagnosis of breast mass by histopathological examination and immunohistochemistry. IB achieved a good result in the treatment of the breast mass. We hope to provide reference of prognosis and treatment when facing this situation by presenting this case.

Associations between gastrointestinal symptoms, medication use, and spontaneous drug discontinuation in patients with major depressive disorder in China.

BACKGROUND: The study was designed to investigate the associations between gastrointestinal (GI) symptoms, medication use, and spontaneous drug discontinuation (SDD) in patients with major depressive disorder (MDD). METHODS: This cross-sectional study included 3256 MDD patients from the National Survey on Symptomatology of Depression (NSSD). Differences in the sociodemographic factors, clinical characteristics, medication use, and self-reported reasons for SDD were compared in patients with different frequencies of GI symptoms. A multiple logistic regression analysis was employed to assess the contribution of GI symptoms to the risk of spontaneous drug discontinuation. RESULTS: MDD patients with a higher frequency of GI symptoms were prone to have higher proportions of mood stabilizer and benzodiazepine uses (ps for trend < 0.001) but a lower proportion of SNRI use (pfor trend < 0.001). With the increase in GI symptoms, patients were prone to report worries about long-term side effects (pfor trend < 0.001), with the patients stating ineffective treatments (pfor trend = 0.002) and intolerance of adverse drug reactions (pfor trend = 0.022) as the reasons for SDD. Compared with those patients without GI symptoms, all of the MDD patients with GI symptom frequencies of several days (OR = 1.317; 95 % CI: 1.045-1.660), more than half of all days (OR = 1.305; 95 % CI: 1.005-1.695), and nearly every day (OR = 1.820; 95 %: 1.309-2.531) had an increased risk of SDD. CONCLUSION: GI symptoms are highly associated with drug discontinuation in MDD patients. These findings may have important implications for clinical treatment options, as well as for drug adherence management, in MDD patients.

Licoflavone A Suppresses Gastric Cancer Growth and Metastasis by Blocking the VEGFR-2 Signaling Pathway.

Objectives: Licoflavone A (LA) is a natural flavonoid compound derived from the root of Glycyrrhiza. This study investigated the antitumor effect and underlying molecular mechanisms of LA against gastric cancer (GC) in vitro and in vivo. Materials and Methods: A CCK8 assay was used to measure the antiproliferative activity of LA in human GC SGC-7901, MKN-45, MGC-803 cells, and human GES-1 cells. Target prediction and protein-protein interaction (PPI) analysis were used to identify the potential molecular targets of LA. The binding pattern of LA to VEGFR-2 was analyzed by molecular docking and molecular dynamic (MD). The affinity of LA for VEGFR-2 was determined by microscale thermophoresis (MST). The protein tyrosine kinase activity of VEGFR-2 in the presence of LA was determined by an enzyme activity test. The effect of LA on the proliferation of VEGF-stimulated MKN-45 cells was measured with CCK8 assays, clone formation assays, and 3D microsphere models. Hoechst 33342 staining, FCM, MMP, and WB assays were used to investigate the ability of LA to block cell cycle and promote apoptosis of VEGF-stimulated MKN-45 cells. Transwell matrix assays were used to measure migration and invasion, and WB assays were used to measure EMT. Results: LA inhibited the proliferation of SGC-7901, MKN-45, and MGC-803 cells and VEGF-stimulated MKN-45 cells. VEGFR-2 was identified as the target of LA. LA could also block cell cycle, induce apoptosis, and inhibit migration, invasion, and EMT of VEGF-stimulated MKN-45 cells. Functional analyses further revealed that the cytotoxic effect of LA on VEGF-stimulated MKN-45 cells potentially involved the PI3K/AKT and MEK/ERK signaling pathways. Conclusions: This study demonstrates that LA has anti-GC potency in vitro and in vivo. LA affects the proliferation, cycle, apoptosis, migration, invasion, and EMT by targeting VEGFR-2 and blocks the PI3K/AKT and MEK/ERK signaling pathways in VEGF-stimulated MKN-45 cells.

Sterile alpha motif and histidine-aspartic acid domain-containing protein 1 expression and its relationship with T cell activation in human immunodeficiency virus/acquired immune deficiency syndrome patients with lung-spleen deficiency syndrome pattern.

OBJECTIVE: To investigate the relationship between antiviral restriction factor Sterile Alpha Motif and Histidine-Aspartic acid domain-containing protein 1 (SAMHD1) expression and T cell activation, furthermore, identifying objective indexes of lung-spleen deficiency symptom pattern. METHODS: We assessed the profile of T lymphocyte subsets, characteristics of SAMHD1 and human leukocyte antigen DR (HLA-DR) expression in lung-spleen deficiency patients. At the same time, people living with human immunodeficiency virus / acquired immune deficiency syndrome (HIV/AIDS) (PLWHA) without obvious clinical symptoms and healthy donors in this area were used as controls. RESULTS: Immunohematologic indexes lower CD4 count, lower CD4/CD8 ratio and higher SAMHD1 level were found in lung-spleen deficiency patients. Furthermore, we demonstrated a positive relationship between SAMHD1 and HLA-DR level as well as with interferon factor in lung-spleen deficiency syndrome and patients without obvious clinical signs and symptoms groups. CONCLUSIONS: These data indicated the positive relationship between SAMHD1 and T cell activation which further elucidated the role of SAMHD1 in cellular immune response. Furthermore, combination of T lymphocyte subsets counts and SAMHD1 level may be used as clinical and biological reference basis for the differentiation and diagnosis of HIV / AIDS traditional Chinese medicine syndromes.

Three important short-chain fatty acids (SCFAs) attenuate the inflammatory response induced by 5-FU and maintain the integrity of intestinal mucosal tight junction.

BACKGROUND: 5-Fluorouracil (5-FU) is a used chemotherapy drug for cancer, and its main side effect is intestinal mucositis which causes chemotherapy to fail. It was known that short-chain fatty acids (SCFAs) can inhibit immune cell release of various proinflammatory factors and inhibit excessive intestinal inflammation. However, the inhibitory effect of SCFAs on 5-FU-induced intestinal mucositis is still unclear. RESULTS: To simulate the effects of SCFAs on immune and intestinal epithelial cells, the cells (THP-1 cells and Caco-2 cells) were pretreated with sodium acetate (NaAc), sodium propionate (NaPc) and sodium butyrate (NaB), then inflammation was induced by 5-FU. The expressions of reactive oxygen species (ROS), Beclin-1, LC3-II, NF-κB p65, NLRP3 inflammasome, proinflammatory/anti-inflammatory cytokines and mucosal tight junction proteins were determined. In our results, the three SCFAs could inhibit ROS expressions, NLRP3, Caspase-1, IL-1ß, IL-6, IL-18, Beclin-1 and LC3-II, when induced by 5-FU. In a 5-FU-induced chemoentermuctis mouse model, Lactobacillus rhamnoides can increase the concentrations of three SCFAs in faeces and increase the concentrations of IL-1ß, IL-6 and IgA in serum, and decrease the expressions of NLRP3 and IL-17 in spleen cells. The expressions of ZO-1 and Occludin in intestinal mucosa were significantly increased. CONCLUSIONS: These results indicated that the three SCFAs can effectively suppress the inflammation of THP-1 cells and Caco-2 cells and maintain tight junction integrity in intestinal mucosal epithelial cells.

The effect of anaerobic co-fermentation on acidification performance of food waste and cardboard waste.

The fermentation system with high solid materials for food waste (FW) is uneven in nutrition and easy to produce volatile acid accumulation, which causes the reaction system to acidify and affects the normal operation of fermentation. This study evaluated the effect of the co-substrate percentages (FW:CB = 9:1, FW:CB = 8:2, FW:CB = 7:3) and the initial total solid contents (12%, 15%, 18%) on the co-fermentation acidification performance of FW and cardboard waste (CB). The maximum methane production was obtained when mono-fermenting FW had high solids contents (1.4 L/kg). The methane production increased and then decreased with the increasing percentages of CB. Under the conditions of FW:CB = 8:2, the maximum methane production could reach 3.4 L/kg. The lower methane production (1.8 - 2.5 L/kg) with high percentages of CB (FW:CB = 7:3) was translated into higher yields of caproic acid (up to 26%), which indicated that lower percentages of CB had a stabilization effect due to the higher buffering capacities in co-fermentation. As a result, this study demonstrated new possibilities for using CB percentages to control the production of high added-value biogas in dry co-fermentation of FW.

The regioselectivity of the interaction between dextromethorphan and CYP2D6.

CYP2D6 is an important enzyme of the cytochrome P450 superfamily, and catalyzes nearly 25% of the drugs sold in the market. For decades, the interactions and metabolism between CYP2D6 and substrates have been a hot topic. However, the key factors of the catalytic regioselectivity for CYP2D6 still remain controversial. Here, we construct four systems to explore the interaction between dextromethorphan (DM) and CYP2D6. A new binding mode of CYP2D6 is defined, and two key residues (residue Asp301 and residue Glu216) are discovered working simultaneously to stabilize the DM at the reactive site by forming water bridge hydrogen bonds when CYP2D6 binds DM. Our results also indicate that the substrate concentration could mediate the binding mode between the substrate and CYP2D6 by decreasing the volume of the catalytic pocket, which is not conducive to the O-demethylation of DM but benefits the N-demethylation of DM. These results could shed light on the process of CYP2D6 binding to the substrate, and help to better understand the regioselectivity of CYP2D6 catalyzing the substrates.