Comprehensive analysis of peroxisome proliferator-activated receptors to predict the drug resistance, immune microenvironment, and prognosis in stomach adenocarcinomas.

Background: Peroxisome proliferator-activated receptors (PPARs) exert multiple functions in the initiation and progression of stomach adenocarcinomas (STAD). This study analyzed the relationship between PPARs and the immune status, molecular mutations, and drug therapy in STAD. Methods: The expression profiles of three PPAR genes (PPARA, PPARD and PPARG) were downloaded from The Cancer Genome Atlas (TCGA) dataset to analyze their expression patterns across pan-cancer. The associations between PPARs and clinicopathologic features, prognosis, tumor microenvironment, genome mutation and drug sensitivity were also explored. Co-expression between two PPAR genes was calculated using Pearson analysis. Regulatory pathways of PPARs were scored using gene set variation analysis (GSVA) package. Quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, Cell Counting Kit-8 (CCK-8) assay and transwell assay were conducted to analyze the expression and function of the PPAR genes in STAD cell lines (AGS and SGC7901 cells). Results: PPARA, PPARD and PPARG were more abnormally expressed in STAD samples and cell lines when compared to most of 32 type cancers in TCGA. In STAD, the expression of PPARD was higher in Grade 3+4 and male patients, while that of PPARG was higher in patient with Grade 3+4 and age > 60. Patients in high-PPARA expression group tended to have longer survival time. Co-expression analysis revealed 6 genes significantly correlated with the three PPAR genes in STAD. Single-sample GSEA (ssGSEA) showed that the three PPAR genes were enriched in 23 pathways, including MITOTIC_SPINDLE, MYC_TARGETS_V1, E2F_TARGETS and were closely correlated with immune cells, including NK_cells_resting, T_cells_CD4_memory_resting, and macrophages_M0. Immune checkpoint genes (CD274, SIGLEC15) were abnormally expressed between high-PPAR expression and low-PPAR expression groups. TTN, MUC16, FAT2 and ANK3 genes had a high mutation frequency in both high-PPARA/PPARG and low-PPARA/PPARG expression group. Fourteen and two PPARA/PPARD drugs were identified to be able to effectively treat patients in high-PPARA/PPARG and low-PPARA/PPARG expression groups, respectively. We also found that the chemotherapy drug Vinorelbine was positively correlated with the three PPAR genes, showing the potential of Vinorelbine to serve as a treatment drug for STAD. Furthermore, cell experiments demonstrated that PPARG had higher expression in AGS and SGC7901 cells, and that inhibiting PPARG suppressed the viability, migration and invasion of AGS and SGC7901 cells. Conclusions: The current results confirmed that the three PPAR genes (PPARA, PPARD and PPARG) affected STAD development through mediating immune microenvironment and genome mutation.

The effect and safety of obeticholic acid for patients with nonalcoholic steatohepatitis: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NASH) is one of the primary causes of chronic liver disease worldwide. Obeticholic acid (OCA), a potent farnesoid X nuclear receptor activator, has shown promise for treating NASH-related fibrosis due to its anti-fibrotic effects. This study aimed to examine the efficacy of OCA for patients with NASH as well as to investigate its impact on dyslipidemia. METHOD: A search of databases including PubMed, Embase, and Cochrane Library from January 1, 2010, to November 1, 2022, was conducted to identify systematic reviews of randomized controlled trials involving NASH patients. Inclusion criteria comprised randomized controlled trials that specifically addressed NASH as diagnosed through magnetic resonance imaging, computed tomography, or histology. The results were then categorized, with consideration given to both biochemical and histological outcomes. RESULT: Five NASH studies were ultimately selected for further analysis. In terms of biochemical indicators, patients receiving OCA treatment showed improvements in alanine transaminase (mean difference: -19.48, 95% confidence interval [CI]: -24.39 to 14.58; P < .05) and aspartate aminotransferase (mean difference: -9.22, 95% CI: -12.70 to 5.74; P < .05). As for histological improvement, OCA treatment reduced fibrosis (odds ratio [OR]: 1.95, 95% CI: 1.47-2.59; P = .001) and steatosis (OR: 1.95, 95% CI: 1.47-2.59; P = .001). No significant differences were observed regarding adverse events (1.44, 95% CI: 0.57-3.62; P > .001). Regarding dyslipidemia, mean differences between total cholesterol and low-density lipoprotein were found to be high (0.33, 95% CI: 0.01-0.64, P < .05; 0.39, 95% CI: 0.04-0.73, P < .05). In the case of pruritus, OCA achieved a high OR (3.22, 95% CI: 2.22-4.74) compared with placebo. CONCLUSION: OCA also reduced several liver test markers compared to placebo, including the biochemical indicators alanine transaminase, aspartate aminotransferase, alkaline phosphatase, and γ-glutamyl transpeptidase, and improved hepatocellular ballooning, fibrosis, steatosis, and lobular inflammation. Although the incidence of adverse events did not significantly differ between OCA and placebo groups among NASH patients, OCA treatment was found to elevate total cholesterol and low-density lipoprotein levels, and the reported severity of pruritus increased with higher doses of OCA.

Effects of beauvericin on the blood cells of Bombyx mori.

In this study, silkworms were treated by injection of the bioactive depsipeptide beauvericin (BEA) to explore its effect on the cellular immunity of larvae of the silkworm Bombyx mori. The results showed that: The LC50 of BEA for silkworms on the 3rd day of the 4th instar was 362.36 µM. The total count of circulating hemocytes in the silkworms decreased at 12 h after injection with 350 µM BEA, and reached the minimum value at 72 h post-treatment; at 48 h post-treatment, a large number of nodules formed by the aggregation of blood cells of the silkworms were observed under the light microscope. The survival rate of hemocytes in the larvae treated with BEA was significantly reduced in a dose-dependent manner in vivo and in vitro. The encapsulation of Q-Sepharose Fast Flow (QFF) gel particles by hemocytes in the treatment group was significantly higher than that in the control group at 1.5 h and 3 h post-treatment (P < 0.05). Moreover, the melanization ratio of QFF gel particles kept increasing with treatment time. The melanization rate at 24 h after treatment was significantly higher than that at other times (P < 0.05), reaching 55.33 %. Under the scanning electron microscope, BEA-treated larvae showed protrusions on the surface of their blood cells in vivo. Under the transmission electron microscope, it was observed that silkworm hemocytes were vacuolated. This study demonstrated that BEA had an effect on the blood cells of silkworms, and has thrown some light on the inhibitory effect and mechanism of BEA on insect cellular immunity.

Integrating electronic structure regulation and dynamic active sites construction on NixCd1-xS-Ni0 photocatalyst for efficient hydrogen evolution.

Regulating electronic structure and enriching active sites of photocatalysts are effective strategies to promote hydrogen evolution. Herein, a unique NixCd1-xS-Ni0 photocatalyst, including the surface nickel (Ni) doping and atomic Ni0 anchoring sites, is successfully prepared by Ni2+ ions exchange reaction (Ni2++ CdS â†’ NixCd1-xS) and in-situ photo-induction of Ni0(Ni2++NixCd1-xS→hνNixCd1-xS-Ni0), respectively. As to Ni doping, the Ni replaced cadmium (Cd) atoms introduce hybridized states around the Fermi level, modulating the electronic structure of adjacent S atoms and optimizing the photocatalytic activity of sulfur (S) atoms. Besides, photogenerated Ni0 atoms, anchored on unsaturated S atoms, act as charge transfer bridges to reduce Ni2+ ions in the solution to Ni clusters (NixCd1-xS-Ni0→ne-NixCd1-xS-Ni). Subsequently, the displacement reaction of Ni clusters with protons (H+) spontaneously proceeds to produce hydrogen (H2) in an acidic solution (NixCd1-xS-Ni→2H+H2↑+Ni2++NixCd1-xS-Ni0). The equilibrium of photo-deposition/dissolution of Ni clusters realizes the construction of dynamic active sites, providing sustainable reaction centers and enhancing surface redox kinetics. The NixCd1-xS-Ni0 exhibits a high hydrogen evolution rate of 428 mmol·h-1·g-1 with a quantum efficiency of 75.6 % at 420 nm. This work provides the optimal S electronic structure for photocatalytic H2 evolution and constructs dynamic Ni clusters for chemical replacement reaction. This work provides the optimal S electronic structure for photocatalytic H2 evolution and constructs dynamic Ni clusters for displacement reaction, opening a dual pathway for efficient water reduction.

Interface engineering of Mo-doped Ni9S8/Ni3S2 multiphase heterostructure nanoflowers by one step synthesis for efficient overall water splitting.

Accelerating charge transfer efficiency by constructing heterogeneous interfaces on metal-based substrates is an effective way to improve the electrocatalytic performance of materials. However, minimizing the substrate-catalyst interfacial resistance to maximize catalytic activity remains a challenge. This study reports a simple interface engineering strategy for constructing Mo-Ni9S8/Ni3S2 heterostructured nanoflowers. Experimental and theoretical investigations reveal that the primary role assumed by Ni3S2 in Mo-Ni9S8/Ni3S2 heterostructure is to replace nickel foam (NF) substrate for electron conduction, and Ni3S2 has a lower potential energy barrier (0.76 to 1.11 eV) than NF (1.87 eV), resulting in a more effortless electron transfer. The interface between Ni3S2 and Mo-Ni9S8 effectively regulates electron redistribution, and when the electrons from Ni3S2 are transferred to Mo-Ni9S8, the potential energy barriers at the heterogeneous interface are 1.06 eV, lower than that between NF and Ni3S2 (1.53 eV). Mo-Ni9S8/Ni3S2-0.1 exhibited excellent oxygen evolution reaction (OER)/hydrogen evolution reaction (HER) bifunctional catalytic activity in 1 M KOH, with overpotentials of only 223 mV@100 mA cm-2 for OER and 116 mV@10 mA cm-2 for HER. Moreover, when combined with an alkaline electrolytic cell, it required only an ultra-low cell voltage of 1.51 V to drive a current density of 10 mA cm-2. This work provides new inspirations for rationally designing interface engineering for advanced catalytic materials.

Glutamine synthetase plays an important role in ammonium tolerance of Myriophyllum aquaticum.

High-strength ammonium (NH4+), the main characteristic of swine wastewater, poses a significant threat to the rural ecological environment. As a novel phytoremediation technology, Myriophyllum aquaticum wetlands have high tolerance and removal rate of NH4+. Glutamine synthetase (GS), a pivotal enzyme in nitrogen (N) metabolism, is hypothesized to play an important role in the tolerance of M. aquaticum to high NH4+. Herein, the responses of M. aquaticum to GS inhibition by 0.1 mM methionine sulfoximine (MSX) under 15 mM NH4+ were investigated. After 5 days, visible NH4+ toxicity symptoms were observed in MSX-treated plants. Compared with the control, the NH4+ accumulation in the leaves increased by 20.99 times, while that of stems and roots increased by 3.27 times and 47.76 %, suggesting that GS inhibition had a greater impact on the leaves. GS inhibition decreased pigments in the leaves by 8.64 %-41.06 %, triggered oxidative stress, and affected ions concentrations in M. aquaticum. The concentrations of glutamine (Gln) and asparagine decreased by 63.46 %-97.43 % and 12.37 %-76.41 %, respectively, while the concentrations of most other amino acids increased after 5 days of MSX treatment, showing that GS inhibition reprogrammed the amino acids synthesis. A decrease in Gln explains the regulations of N-related genes, including increased expression of AMT in roots and decreased expression of GS, GOGAT, GDH, and AS, which would cause further NH4+ accumulation via promoting NH4+ uptake and decreasing NH4+ assimilation in M. aquaticum. This study revealed for the first time that GS inhibition under high NH4+ condition can lead to phytotoxicity in M. aquaticum due to NH4+ accumulation. The physiological and molecular responses of the leaves, stems, and roots confirmed the importance of GS in the high NH4+ tolerance of M. aquaticum. These findings provide new insights into NH4+ tolerance mechanisms in M. aquaticum and a theoretical foundation for the phytoremediation of high NH4+-loaded swine wastewater.

Physiological response and tolerance of Myriophyllum aquaticum to a wide range of ammonium concentrations.

Myriophyllum aquaticum (M. aquaticum) can be used in constructed wetlands (CWs) to effectively purify swine wastewater with high-ammonia nitrogen (NH3-N and NH4+-N) concentrations. However, the understanding of its tolerance mechanism to ammonia nitrogen is limited. The physiological response and tolerance mechanism of M. aquaticum to a wide range of NH4+ concentrations (0-35 mM) were investigated in the present study. The results indicated that M. aquaticum can tolerate NH4+ concentrations of up to 30 mM for 21 days and grow well with high nutrient (N, P) uptake. A suitable concentration of NH4+ for a better growth of M. aquaticum was 0.5-20 mM. The free NH4+ content was no obviously increase at NH4+ concentration below 15 mM, indicated there was no obviously ammonium accumulation. Exogenous NH4+ inhibited K+ absorption and improved Ca2+ absorption, indicating mineral cation could mediate NH4+ homeostasis under NH4+ stress. Moreover, comparison with those in the control group, the activities of glutamine synthetase (GS), glutamate synthetase (GOGAT) in M. aquaticum increased by 52.7%-115% at 1-20 mM NH4+, and superoxide dismutase (SOD) increased by 29.2-143% at 1-35 mM NH4+. This indicated that the high NH4+ tolerance of M. aquaticum was mainly due to the balance of free NH4+ content in tissues, as well as improved nitrogen metabolism and antioxidant system. This could be attributed to the role of the GS-GOGAT cycle and SOD. In conclusion, M. aquaticum, which tolerates high NH4+ concentration and has a high N uptake ability, can be used as a good candidate specie to help develop more efficient management strategies for treating high-NH4+ wastewater in CW systems.

Role of salivary glycopatterns for oral microbiota associated with gastric cancer.

Microbiota in the oral cavity plays an important role in maintaining human health. Our previous studies have revealed significant alterations of salivary glycopatterns in gastric cancer (GC) patients, but it is unclear whether these altered salivary glycopatterns can cause the dysbiosis of oral microbiota. In this study, the oral microbiome of healthy volunteers (HVs) and GC patients were detected. The neoglycoproteins were then synthesized according to the altered glycopatterns in GC patients and used to explore the effects of specific salivary glycopattern against oral microbiota. The results showed that five species were significantly increased (p < 0.05) while two species were significantly decreased (p < 0.01) in the saliva of GC patients compared with that of HVs. And the fucose-neoglycoproteins (30-100 µg/mL) could reduce the adhesion and toxicity of Aggregatibacter segnis (A. segnis) to oral cells (HOEC and CAL-27), change the glycan structures of lipopolysaccharide on the surface of A. segnis, and enhance the capacity of A. segnis to trigger innate immune responses. This study revealed that the changes of salivary protein glycopatterns in GC patients might contribute to the dysbiosis of oral microbiota, and had important implications in developing new carbohydrate drugs to maintain a balanced microbiota in the oral.

The Dislocation- and Cracking-Mediated Deformation of Single Asperity GaAs during Plowing Using Molecular Dynamics Simulation.

This work simulates the plowing process of a single asperity GaAs by diamond indenter using molecular dynamics simulations. The deformation mechanism of asperity GaAs is revealed by examining the topography evolution and stress state during the plowing. This work also investigates the origin of the influence of asperity size, indenter radius and plow depth on the deformation of the asperity GaAs. We observed the initiation and propagation of cracks up to the onset of fracture and the plastic activity near the indenter, obtaining more information usually not available from planar GaAs in normal velocity plowing compared to just plastic activity. The simulations demonstrated the direct evidence of cracking in GaAs induced by plowing at an atomic level and probed the origin and extension of cracking in asperity GaAs. This finding suggests that cracking appears to be a new deformation pattern of GaAs in plowing, together with dislocation-dominated plasticity modes dominating the plowing deformation process. This work offers new insights into understanding the deformation mechanism of an asperity GaAs. It aims to find scientific clues for understanding plastic removal performed in the presence of cracking.

Unveiling the role of sediments in phosphorus removal in pilot-scale constructed wetlands for swine wastewater treatment.

The accumulation rate, fractions, and sorption capacity of phosphorus in sediments determine the removal efficiency and service life of constructed wetlands (CWs). Nine pilot-scale three-stage surface flow CWs were constructed to treat three loading rates of lagoon-pretreated swine wastewater, and surface sediment samples at initial and one-year treatment were collected to analyze the phosphorus fractions and sorption capacity. After one-year treatment, concentration of total phosphorus (TP) in sediments increased for high loading rates of wastewater, but remained stable for low loading rates. The annual accumulation rate of TP in sediments (Ma) was -43-445 mg kg-1 yr-1 at surface loading rate (SLR) of 36-355 g P m-2 yr-1. Their association could be described well using a sigmoid model, i.e., Ma = -23 + 538/(1 + exp.(-(SLR-262)/48)) (R2adj = 0.897, RMSE = 40.8, p < 0.01), indicating that the phosphorus accumulation rates in sediments were loading rate-dependent. The sum of inorganic phosphorus fractions contributed to 80-100% of the TP concentration, and accumulation of aluminum-bound phosphorus (AlP) and iron-bound phosphorus (FeP) was responsible for variability of TP concentration in sediments. Phosphorus sorption capacity of CW1 sediments increased by 1.3-1.8 times, attributed to increased pH, and concentrations of ammonium oxalate-extractable aluminum and iron in sediments due to the wastewater input. Selecting iron and aluminum-rich materials preferentially as substrates and regulating the ratio of metal ions to phosphorus in wastewater should be alternative enhancement strategies of CWs for phosphorus removal.

Design and Research of Mathematics Teaching Intelligent Classroom Based on PCA-NN Algorithm.

With the increasing importance of mathematics in basic education, how to evaluate and analyze the intelligent effect of mathematics teaching classroom through scientific methods has become one of the indicators to evaluate the intelligent classroom. This paper studies the design and application of mathematics teaching intelligent classroom based on the PCA-NN (principal component analysis-neural network) algorithm. Firstly, this paper briefly describes the current research status of mathematics teaching intelligent classroom design and PCA-NN algorithm. Secondly, combined with the key factors of mathematics teaching, it formulates specific standards and puts forward an adaptive strategy of intelligent and personalized intelligent mathematics teaching classroom. Finally, the algorithm is verified by experiments. The results show that, for students with different mathematics basic levels, the mathematics teaching intelligent classroom based on the PCA-NN algorithm can effectively improve the quality of mathematics classroom teaching. Through the research on the factors such as teaching quality, effect, and interaction mode involved in the process of mathematics teaching classroom design, the intelligent classroom design factors affecting teaching quality are determined. This paper analyzes and studies the system from different angles. The research results provide some help for the current quality evaluation of classroom teaching and use the PCA-NN algorithm to make quantitative analysis and multivariate verification of mathematics classroom teaching effect.

[Effect of influenza virus on chemokine pathways in mice lungs and intervention of Shufeng Xuanfei Jiedu formula].

OBJECTIVE: To screen the differentially expressed genes on whole expression profiles of the inflammation-related cytokines in mice infected with influenza virus by the gene chip technology, and to explore the intervention effect of Shufeng Xuanfei Jiedu formula. METHODS: Male ICR mice were divided into normal group (N group), influenza virus infective model group (M group), Oseltamivir control group (C group) and Shufeng Xuanfei Jiedu formula high, medium and low dose groups (SH, SM, SL groups) according to the random number table method, with 10 rats in each group. A mouse model of influenza virus pneumonia was reproduced by nasal drip of influenza virus strain FM1 (0.05 mL). In N group, 0.05 mL normal saline was used. In SH, SM and SL groups, Shufeng Xuanfei Jiedu formula was used 2 hours after intranasal infection (2 times, equal and 1/2 of the clinical treatment dose, approximately 3.8, 1.9 and 1.0 g×mL-1×d-1) for 4 days. In C group, the dosage of Oseltamivir was 2.5 g×mL-1×d-1. In N group and M group, distilled water was given (0.2 mL once a day). On the 5th day, the whole lung of mice was taken. The lung index was calculated, and the pathological sections were observed. The total RNA of lung tissue was extracted and detected after hybridization with mice whole gene expression spectrum chip to select differentially expressed genes of chemokine pathways. The expression intensity ratio of the chip probe signal in each group vs. M group was calculated, and P < 0.05 and log2ratio > 1 were up-regulated genes, while P < 0.05 and log2ratio < -1 were down-regulated genes. RESULTS: Compared with the N group, the lung index in the M group was significantly higher, and pathological changes were found in lung tissue, which suggested that the model of influenza virus infection was successfully established. Compared with the M group, the lung index of mice in C, SH, SM, SL groups was significantly lower (0.96±0.14, 1.45±0.22, 1.14±0.18, 1.22±0.21 vs. 1.72±0.15, all P < 0.05), and the extent and degree of lesions were reduced, however, there was no significant difference among the groups. Gene chip analysis showed that there were more differentially expressed genes in N group vs. M group, SH group vs. M group, SM group vs. M group, SL group vs. M group. It could be used for further signal transduction pathway screening. Compared with N group, the differential gene expression of chemokine C-C ligands (CCL-3, CCL-5) and chemokine C-X-C ligands (CXCL-9, CXCL-10) in M group were significantly up-regulated [log2 (M group/N group) were 6.64, 3.51, 5.40, 6.64, respectively]. Compared with M group, the gene expressions of CCL-3, CCL-5, CXCL-9 and CXCL-10 were significantly down-regulated in C, SH, SM and SL groups [log2 (C group/M group) were -3.96, -2.26, -3.12, -2.40; log2 (SH group/M group) were -5.57, -2.37, -1.57, -1.01; log2 (SM group/M group) were -4.35, -1.47, -1.26, -1.74; log2 (SL group/M group) were -2.86, -1.86, -1.23, -1.39, respectively]. CONCLUSIONS: Shufeng Xuanfei Jiedu formula inhibits inflammatory damage in mice after influenza virus infection by down-regulating the expressions of CCL-3, CCL-5, CXCL-9 and CXCL-10 on chemokine pathways.

Concentration and Community of Airborne Bacteria in Response to Cyclical Haze Events During the Fall and Midwinter in Beijing, China.

Since 2013, severe haze events frequently have occurred in Beijing between October and March, which have created a significant public health threat. Although variations in the chemical composition of these haze events have been studied widely, information pertaining to airborne bacteria in such haze events remains limited. In this study, we characterized the concentration, community structure, and composition of the airborne bacteria in response to nine haze events that occurred between October 1, 2015, and January 5, 2016. We also analyzed the correlations of airborne bacteria (concentration, community structure, and composition) with pollution levels and meteorological factors. The results indicated that airborne bacterial concentration showed a positive cyclical correlation with the haze events, but the bacterial concentration plateaued at the yellow pollution level. In addition, we found particulate matter (PM10) and relative humidity to be key factors that significantly affected the airborne bacterial concentration and community structure. Moreover, Halomonas and Shewanella were enriched on haze days for all nine of the haze events. Finally, the correlations between haze pollution and airborne bacteria in midwinter were weaker than those in fall and early winter, indicating an obvious staged distinction among the effects of haze on airborne bacteria. Our study illuminated the dynamic variation of bioaerosols corresponding to the cyclical haze events and revealed the interactions among air pollution, climate factors (mainly relative humidity), and airborne bacteria. These results imply that different strategies should be applied to deal with the potential threat of airborne bacteria during haze events in different seasons.

Novel Butane-Oxidizing Bacteria and Diversity of bmoX Genes in Puguang Gas Field.

To investigate the diversity of butane-oxidizing bacteria in soils contaminated by long-term light hydrocarbon microseepage and the influence of butane on the soil microbial community, a quantitative study and identification of butane-oxidizing bacteria (BOB) in soils at the Puguang gas field were performed by DNA-based stable isotope probing (DNA-SIP). For the first time, two phylotypes corresponding to the genera Giesbergeria and Ramlibacter were identified as being directly involved in butane oxidation, in addition to the well-known light hydrocarbon degrader Pseudomonas. Furthermore, bmoX genes were strongly labeled by 13C-butane, and their abundances in gas field soils increased by 43.14-, 17.39-, 21.74-, and 30.14-fold when incubated with butane for 6, 9, 12, and 14 days, respectively, indicating that these bmoX-harboring bacteria could use butane as the sole carbon and energy source and they play an important role in butane degradation. We also found that the addition of butane rapidly shaped the bacterial community and reduced the diversity of bmoX genes in the gas field soils. These findings improve our understanding of BOB in the gas field environment and reveal the potential for their applications in petroleum exploration and bioremediation.

[Effects of Long-term Fertilization Regimes on Microbial Biomass, Community Structure and Activity in a Paddy Soil].

Four paddy soils were collected in Ningxiang County, Hunan province. These used with different long-term fertilization regimes, including a control without fertilizer (CK), chemical fertilization with nitrogen, phosphate, and kalium (NPK), straw fertilization combined with NPK (ST), and manure fertilization combinedwith NPK (OM). Phospholipid fatty acid (PLFA) technology and MicrorespTM method were used to study the effect of long-term fertilization on soil microorganism abundance, community structure, and activity. Results showed that the abundance of bacteria, fungi, gram-negative (G-) bacteria, and gram-positive (G+) bacteria in the soil from the OM treatment was generally higher than for the other treatments; these levels were lower in the ST and NPK treatments and lowest in the CK treatment. The principal components analysis (PCA) of PLFA showed that the community structure of microorganisms in NPK, ST, and OM treatments was altered in comparison with that in CK, especially in the case of the ST and OM treatments. MicroRespTM results revealed that compared to the CK treatment (1.28 µg·h-1), soil microorganisms in the OM treatment had the highest average utilization rate of multiple carbon sources (1.81 µg·h-1), followed by ST (1.19 µg·h-1), CK (1.28 µg·h-1), and NPK (0.95 µg·h-1). Furthermore, different long-term fertilization regimes resulted in distinct carbon source preferences for the soil microorganisms and revealed a significant alteration in the microbial community. Conclusively, long-term fertilizer with straw or manure changes the microbial community and is a benefit for improving the biomass and activity of microorganism in rice paddy soils.

Upregulated expression of human cathelicidin LL-37 in hypercholesterolemia and its relationship with serum lipid levels.

Dyslipidemia in patients with hypercholesterolemia has been recently linked to increased human cathelicidin LL-37 (LL-37) serum concentration. We tested a hypothesis that upregulated expression of LL-37 gene in peripheral blood leucocytes is involved in dyslipidemia in patients with hypercholesteremia. Patients with hypercholesterolemia were used in the study. Expression of LL-37 and human glyceraldehyde-3-phosphate dehydrogenase in peripheral blood leucocytes were quantified by real-time RT-PCR. Serum LL-37 concentration was estimated by enzyme-linked immunosorbent assay. Serum lipid levels were assessed by absorptiometry in all cases. Patients with hypercholesterolemia as compared to control ones were characterized by (a) an up-regulation of LL-37 gene expression in peripheral blood leucocytes with parallel increase of serum LL-37 concentration and (b) an increase of serum total and low-density lipoprotein cholesterol concentrations. Patients with hypercholesterolemia after a treatment with atorvastatin calcium 20 mg daily as compared to that patients before the treatment: an down-regulation of LL-37 gene expression in peripheral blood leucocytes with parallel decrease of serum LL-37 concentration. We also found significant correlation between serum LL-37 and high-density lipoprotein cholesterol levels (r = 0.7290, P < 0.0001). The results suggest that hypercholesterolemia is associated with an increased LL-37 gene expression in peripheral blood leucocytes. The correlation between serum LL-37 and high-density lipoprotein cholesterol levels suggests that LL-37 may play a key role in regulation of cholesterol levels in hypercholesterolemia.

Water-Soluble Humic Materials Regulate Quorum Sensing in Sinorhizobium meliloti Through a Novel Repressor of expR.

Quorum sensing (QS) plays an important role in the growth, nodulation, and nitrogen fixation of rhizobia. In this study, we show that water-soluble humic materials (WSHM) repress the expression of the QS related genes sinI, sinR, and expR in Sinorhizobium meliloti. This decreased the production of N-acetyl homoserine lactones (AHL) and exopolysaccharides (EPS), and ultimately increased S. meliloti cell density. We also identified a novel regulator, SMc03890 (renamed QsrR), which binds directly to the expR promoter. Deletion of qsrR increased expR expression. WSHM repressed the expression of expR by augmenting the interaction between QsrR and the expR promoter; this was determined by a bacterial-one-hybrid assay. These effects of WSHM on the QS system in S. meliloti may be the underlying mechanism by which WSHM increase the symbiotic nitrogen fixation of Medicago sativa inoculated with S. meliloti. This study provides the first evidence that humic acids regulate the QS of rhizobia and suggests that WSHM could be used as fertilizers to improve the efficiency of symbiotic nitrogen fixation.

Biogenic selenium and its hepatoprotective activity.

Elemental selenium nanoparticles (SeNPs) have multiple biological activities. In this study, we investigated the protective effects of biogenic SeNPs (BioSeNPs) on CCl4-induced liver damage in mice. The results showed that: (i) when compared to sodium selenite (SS), BioSeNPs has a similar tissue distribution after intragastrical administration to mice; (ii) BioSeNPs and SS showed comparable efficacy in increasing the activities of glutathione peroxidase and thioredoxin reductase in liver cell lines, mice blood and liver; (iii) pretreatment with BioSeNPs inhibiting the elevation of activities of various enzymes significantly which included aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase and liver lipid peroxide (p < 0.05 or p < 0.01) in CCl4-treated mice; (iv) activities of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) were significantly increased (p < 0.05 or p < 0.01) after a pretreatment with BioSeNPs in CCl4-treated mice; (v) histopathological damages in the liver from CCl4-treated mice were ameliorated by a pretreatment with BioSeNPs. In conclusion, these results have shown that BioSeNPs is able to protect the liver from CCl4-induced hepatic damage via increasing the antioxidant capacity and inhibiting oxidative damage. BioSeNPs may have the potential to be used as a trace element food supplement inducing antioxidant bioactivities.

Cell concentration, viability and culture composition of airborne bacteria during a dust event in Beijing.

Airborne bacteria were measured when a dust storm passed Beijing in spring 2012 with a focus on cell concentration, viability and TSA- and R2A-cultured strain composition. The concentration varied at an order of 107cells/m3 with dust loading (demonstrated with PM10) and they had a very close correlation (RT2=0.91, p<0.01). At the time of highest PM10 of 652µg/m3, the bacterial concentration reached 1.4×108cells/m3, which was larger than that before and after the dust event by one order. Bacterial viability, the ratio of number concentration of viable cells to total cells, was 32%-64% and smaller in the dust plume than that before the dust arrival. Bacterial strains from the culture ranged between 2.5×104 and 4.6×105CFU/m3 and no correlation with PM10 was determined. Their composition was different before and after the dust arrival according to 16S rRNA gene sequences and strains belong to Actinomycetes and Firmicutes were the majority in the dust samples.