Clinical characteristics and outcome of double-seropositive patients with anti-glomerular basement membrane antibodies and anti-neutrophil cytoplasmic antibodies.

OBJECTIVE: To explore the clinical characteristics of double-seropositive patients (DPPs) with anti-glomerular basement membrane (Anti-GBM) antibodies and anti-neutrophil cytoplasmic antibodies (ANCA). METHODS: We collected patients with both ANCA and anti-GBM positive glomerulonephritis who were hospitalized in the Department of Nephrology at the First Affiliated Hospital of Nanjing Medical University from January 2010 to August 2022. Retrospective analysis of the baseline clinical characteristics of patients and follow-up to explore relevant factors affecting renal and patient survival. RESULTS: A total of 386 patients, including 69 ANCA negative anti-GBM glomerulonephritis patients, 296 anti-GBM negative ANCA associated vasculitis (AAV) patients, and 21 DPPs were enrolled in this study. Among the 21 DPPs aged 68.0 years (59.5, 74.0), there were 11 males and 10 females. The median serum creatinine at diagnosis was 629.0 (343.85, 788.75) µmol/L, and the median eGFR (CKD-EPI) was 7.58 (4.74, 13.77) mL/min. Fifteen cases (71.4 %) underwent initial RRT. After a follow-up of 40.0 (11.0, 73.0) months, 13 out of 21 DPPs (61.9 %) received maintenance RRT, while 49 out of 69 (71.0 %) ANCA negative anti-GBM-GN patients and 124 out of 296 (41.9 %) anti-GBM negative AAV patients received maintenance RRT (P < 0.001). Kaplan-Meier survival analysis showed that DPPs and ANCA negative anti-GBM-GN patients were more likely to progress to ESRD than anti-GBM negative AAV patients (P = 0.001). Among the 21 patients with DPPs, renal survival was significantly better in patients with better initial renal function, including those who did not receive initial RRT (P = 0.003), with lower serum creatinine levels (Cr < 629.0 µmol/L, P = 0.004) and higher eGFR levels (eGFR ≥ 7.60 ml/min, P = 0.005) than those with poor initial renal function. At the end of follow-up, 14 out of 21 DPPs (66.7 %) survived. Survival analysis showed no significant difference among patients in DPPs group, ANCA negative anti-GBM-GN group, and anti-GBM negative AAV group. CONCLUSIONS: DPPs and ANCA negative anti-GBM-GN patients were more likely to progress to ESRD than anti-GBM negative AAV patients. In DPPs, the poor renal function at diagnosis might be a risk factor associated with poor renal survival.

Preservice teachers' teaching internship affects professional identity: Self-efficacy and learning engagement as mediators.

Preservice teachers' professional identity is a critical factor in their motivation, effectiveness, and retention. Teaching internship can promote the transformation of professional identity and self-efficacy of preservice teachers. The internship environment also enhances students' increasing level of learning engagement. Although much research has shown strong relationship between preservice teachers' teaching internship and professional identity, less is known about how self-efficacy and learning engagement mediated those variables. The purpose of this study is to investigate the roles that self-efficacy and learning engagement play in the relationship between preservice teachers' professional identities and their teaching internship experiences. The study involved 309 preservice teachers in total, and the variables were measured using questionnaires. For the data analysis, we used structural equation modeling. The study's findings are as follows. (a) Teaching internship, professional identity, self-efficacy, and learning engagement were all significantly correlated with one another. (b) Both self-efficacy and learning engagement partially mediated the relationship between teaching internship and professional identity in a parallel manner. (c) Self-efficacy and learning engagement also sequentially mediated the relationship between teaching internship and professional identity.

Use of temporal contact graphs to understand the evolution of COVID-19 through contact tracing data.

Digital contact tracing has been recently advocated by China and many countries as part of digital prevention measures on COVID-19. Controversies have been raised about their effectiveness in practice as it remains open how they can be fully utilized to control COVID-19. In this article, we show that an abundance of information can be extracted from digital contact tracing for COVID-19 prevention and control. Specifically, we construct a temporal contact graph that quantifies the daily contacts between infectious and susceptible individuals by exploiting a large volume of location-related data contributed by 10,527,737 smartphone users in Wuhan, China. The temporal contact graph reveals five time-varying indicators can accurately capture actual contact trends at population level, demonstrating that travel restrictions (e.g., city lockdown) in Wuhan played an important role in containing COVID-19. We reveal a strong correlation between the contacts level and the epidemic size, and estimate several significant epidemiological parameters (e.g., serial interval). We also show that user participation rate exerts higher influence on situation evaluation than user upload rate does, indicating a sub-sampled dataset would be as good at prediction. At individual level, however, the temporal contact graph plays a limited role, since the behavior distinction between the infected and uninfected individuals are not substantial. The revealed results can tell the effectiveness of digital contact tracing against COVID-19, providing guidelines for governments to implement interventions using information technology.

The complete chloroplast genomes of Tetrastigma hemsleyanum (Vitaceae) from different regions of China: molecular structure, comparative analysis and development of DNA barcodes for its geographical origin discrimination.

BACKGROUND: Tetrastigma hemsleyanum is a valuable traditional Chinese medicinal plant widely distributed in the subtropical areas of China. It belongs to the Cayratieae tribe, family Vitaceae, and exhibited significant anti-tumor and anti-inflammatory activities. However, obvious differences were observed on the quality of T. hemsleyanum root from different regions, requiring the discrimination strategy for the geographical origins. RESULT: This study characterized five complete chloroplast (cp) genomes of T. hemsleynum samples from different regions, and conducted a comparative analysis with other representing species from family Vitaceae to reveal the structural variations, informative markers and phylogenetic relationships. The sequenced cp genomes of T. hemsleyanum exhibited a conserved quadripartite structure with full length ranging from 160,124 bp of Jiangxi Province to 160,618 bp of Zhejiang Province. We identified 112 unique genes (80 protein-coding, 28 tRNA and 4 rRNA genes) in the cp genomes of T. hemsleyanum with highly similar gene order, content and structure. The IR contraction/expansion events occurred on the junctions of ycf1, rps19 and rpl2 genes with different degrees, causing the differences of genome sizes in T. hemsleyanum and Vitaceae plants. The number of SSR markers discovered in T. hemsleyanum was 56-57, exhibiting multiple differences among the five geographic groups. Phylogenetic analysis based on conserved cp genome proteins strongly grouped the five T. hemsleyanum species into one clade, showing a sister relationship with T. planicaule. Comparative analysis of the cp genomes from T. hemsleyanum and Vitaceae revealed five highly variable spacers, including 4 intergenic regions and one protein-coding gene (ycf1). Furthermore, five mutational hotspots were observed among T. hemsleyanum cp genomes from different regions, providing data for designing DNA barcodes trnL and trnN. The combination of molecular markers of trnL and trnN clustered the T. hemsleyanum samples from different regions into four groups, thus successfully separating specimens of Sichuan and Zhejiang from other areas. CONCLUSION: Our study obtained the chloroplast genomes of T. hemsleyanum from different regions, and provided a potential molecular tracing tool for determining the geographical origins of T. hemsleyanum, as well as important insights into the molecular identification approach and and phylogeny in Tetrastigma genus and Vitaceae family.

Amino acids profiling and transcriptomic data integration demonstrates the dynamic regulation of amino acids synthesis in the leaves of Cyclocarya paliurus.

Background: Cyclocarya paliurus is a tree well known for its edible and medicinal leaves. Amino acids are essential nutritional components that are present in foods and closely related to the flavor and quality of tea. However, the abundance of amino acids and the regulation of amino acid biosynthesis in the leaves of C. paliurus have not been investigated across different developmental stages. Methods: A combined metabolomic and transcriptomic analysis was employed to investigate the changes in the amino acid profile over several developmental stages (S1, the smallest fully expanded leaf; S3, full leaf enlargement and full leaf thickness; and S2, an intermediate developmental stage between S1 and S3) and the molecular mechanism was elucidated. Results: The results showed that leaves at the S1 stage had the highest content, while those at the S3 stage had the lowest content of amino acids; fourteen differentially expressed genes were involved in the glycolysis pathway, the tricarboxylic acid cycle and the pentose phosphate pathway, which indicated that the reduced abundance of amino acids in the leaves of C. paliurus (mature leaves) may be attributable to reduced gene expression related to carbohydrate metabolism. Four basic leucine zipper transcription factors might play important roles in the regulation of the biosynthesis of amino acids in the leaves of C. paliurus. Conclusions: Leaves at the S1 stage are recommended for high quality tea production because of their high content of amino acids, while leaves at the S2 stage are recommended for generous tea production because of their high levels of sweet flavor amino acids (alanine) and essential amino acids (methionine, phenylalanine, threonine, and tryptophan).

Halomonas salipaludis sp. nov., isolated from a saline-alkali wetland soil.

Strain WRN001T, a Gram-staining-negative, strictly aerobic, non-motile bacterium was isolated from the natural saline-alkali wetland soil of Binhai new district, Tianjin, China (38°46' N, 117°13' E). Cells of strain WRN001T were 0.3-0.5 µm in width and 1.5-2.5 µm in length, and the growth occurred optimally at 33-37 °C, pH 7.5-8.0, and in the presence of 8-10% (w/v) NaCl. Based on 16S rRNA gene sequence analysis, the isolate could be affiliated to the genus Halomonas, and the highest 16S rRNA gene sequence similarity of strain WRN001T to its closest relative Halomonas qiaohouensis DSM 26770 T was 97.5%. The size of the genome as presented here was 5,475,884 bp with a G + C content of 63.8 mol %. The major respiratory quinone of strainWRN001T was Q-9, and the dominant fatty acids were summed feature 8, summed feature 3, C10:0, C12:0, C12:0 3-OH, C16:0, and C17:0 cyclo. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phophatidylcholine (PC), two phospholipids (PL), aminolipid (AL), and three unidentified lipids (L). These data combined with the low digital DDH values between strain WRN001T and the close relative, Halomonas alkalitolerans CGMCC 1.9129 T (42.2%) and based on comparisons with currently available genomes, the highest average nucleotide identity (ANIm) value was 91.4% to Halomonas alkalitolerans CGMCC 1.9129 T (GenBank accession No. GCA_001971685.1). Therefore, we propose a novel species in the genus Halomonas to accommodate this novel isolate: Halomonas salipaludis sp. nov. (type strain WRN001T = KCTC 52853 T = ACCC 19974 T).

Optimized pre-treatment of high strength food waste digestate by high content aluminum-nanocluster based magnetic coagulation.

Coagulation-based pre-treatment efficiency of high strength digestate of food waste (HSDFW) anaerobic digestion is negated by organic ligand-catalyzed decomposition of coagulants. In this study, an efficient HSDFW pre-treatment method, magnetic seeds (MS) coagulation, was employed by using highly stable Keggin Al30 nanocluster (PAC30), MS and polyacrylamide (PAM), and its operation was optimized by evaluating the performance of removing turbidity, total suspended solids (TSS), chemical oxygen demand (COD), and total phosphorous (TP) phosphate. Results showed that at the optimum dosage of 4.82 g/L, PAC30 demonstrated excellent removals as high as 98.93% ± 0.1% of turbidity, 98.04% ± 0.1% of TSS, 58.28% ± 0.3% of total COD, 99.98% ± 0.01% of TP and 99.50% ± 0.01% of dissolved phosphate, respectively. Apparent molecular weight (AMW) and three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy analyses demonstrated more efficient removal of dissolved organic matter (DOM), particularly non-biodegradable and hydrophobic components by PAC30 than commercial coagulant. The sedimentation was much improved from 40 min by coagulation/flocculation to about 5 min settling by MS coagulation. The PAC30 based magnetic coagulation (MC) presents theoretical guidance on a cost-effective and much less footprint pre-treatment alternative for high strength wastewater.

Higenamine attenuates cardiac fibroblast abstract and fibrosis via inhibition of TGF-ß1/Smad signaling.

RATIONALE: Higenamine (HG), is one of the main active components in many widely used Chinese herbs, and a common ingredient of health products in Europe and North America. Several groups, including our own, have previously shown the beneficial effects of HG against cardiomyocyte death during acute ischemic damage. However, the effect of HG on chronic cardiac remodeling, such as cardiac fibrosis, remains unknown. OBJECTIVE: Herein, we aim to investigate the role of HG in cardiac fibrosis in vivo as well as its cellular and molecular mechanisms. METHODS AND RESULTS: Chronic pressure overload with transverse aortic constriction (TAC) significantly increased cardiac hypertrophy, fibrosis, and cardiac dysfunction in mice, which were significantly attenuated by HG. Consistently, cardiac fibrosis induced by the chronic infusion of isoproterenol (ISO), was also significantly reduced by HG. Interestingly, our results showed that HG had no effect on adult mouse CM hypertrophy in vitro. However, HG suppressed the activation of cardiac fibroblasts (CFs) in vitro. Furthermore, TGF-ß1-induced expression of ACTA2, a marker of fibroblast activation, was significantly suppressed by HG. Concomitantly, HG inhibited TGF-ß1-induced phosphorylation of Smad2/3 in CFs. HG also reduced the expression of extracellular matrix molecules such as collagen I and collagen III. To our surprise, the inhibitory effect of HG on CFs activation was independent of the activation of the beta2 adrenergic receptor (ß2-AR) that is known to mediate the effect of HG on antagonizing CMs apoptosis. CONCLUSION: Our findings suggest that HG ameliorates pathological cardiac fibrosis and dysfunction at least partially by suppressing TGF-ß1/Smad signaling and CFs activation.

Comparison of an integrated short-cut biological nitrogen removal process with magnetic coagulation treating swine wastewater and food waste digestate.

An integration of two processes, magnetic coagulation (MC) and short-cut biological nitrogen removal (SBNR), coupled with a sequencing batch membrane bioreactor (SMBR) controlled by an automatic real-time control strategy (RTC), was developed to treat different characteristics of high strength wastewater. The treatment efficiency and microbial community-diversity of the proposed method was evaluated and investigated using swine wastewater and food waste (FW) digestate. The MC showed high removal of TSS (89.1 ± 1.5%, 92.21 ± 1.8%), turbidity (90.58 ± 2.1%, 95.1 ± 2.1%), TP (88.5 ± 1.9%, 92.1 ± 1.5%), phosphate (87.76 ± 1.6%, 91.22 ± 1.5%), and SMBR achieved stable and excellent removal of COD (96.05 ± 0.2%, 97.39 ± 0.2%), TN (97.30 ± 0.3%, 97.44 ± 0.3%) andNH4+-N (99.07 ± 0.2%, 98.54 ± 0.2%) for swine wastewater and FW digestate, respectively. The effluent COD andNH4+-N concentrations were found to meet their discharge standards. The microbial community comparison showed similar diversity and richness, and genus Diaphorobacter and Thaurea were dominant in denitritation, and Nitrosomonas was dominant in nitritation treating both swine wastewater and FW digestate.

Integrated Metabolomic and Transcriptomic Analysis of the Flavonoid Accumulation in the Leaves of Cyclocarya paliurus at Different Altitudes.

Cyclocarya paliurus is a medicinal plant containing flavonoids, triterpenoids, polyphenolics, polysaccharides, and other compounds with diverse biological functions. C. paliurus is distributed across altitudes ranging from 400 to 1,000 m. However, little is known about the effect of altitude on metabolite accumulation in C. paliurus. Also, the biosynthetic pathway involved in flavonoid accumulation in C. paliurus has not been fully elucidated. In this study, mature leaves of C. paliurus growing at low altitude (280 m) and high altitude (920 m) were sampled and subjected to metabolomic and transcriptomic analyses. The flavonoid content and composition were higher in the leaves of C. paliurus collected at high altitude than in those collected at low altitude. Most of the differentially accumulated metabolites (DAMs) were enriched in "flavone and flavonol biosynthesis." The significant differentially expressed genes (DEGs) between low and high altitudes were mainly enriched in "biological process." The most heavily enriched KEGG pathway was related to the subcategory "Oxidative phosphorylation," indicating that complicated biological processes are involved in the response of C. paliurus to harsh environmental factors. High UV-light might be the main influencing factor among the harsh environmental factors found in high altitudes. Integrated analysis of metabolomic and transcriptomic data showed that 31 flavonoids were significantly correlated with 227 DEGs, resulting in 412 related pairs (283 positive and 129 negative) between the DEGs and flavonoids. The possible mechanisms underlying the differentially accumulation of flavonoids at different altitude might be due to variations in transport and relocation of flavonoids in C. paliurus leaves, but not different flavonoid biosynthesis pathways. The up-regulation of genes related to energy and protein synthesis might contribute to flavonoid accumulation at high altitudes. This study broadens our understanding of the effect of altitude on metabolite accumulation and biosynthesis in C. paliurus.

Simultaneous characterization of methane and carbon dioxide produced by cultured methanogens using gas chromatography/isotope ratio mass spectrometry and gas chromatography/mass spectrometry.

RATIONALE: The stable carbon isotope ratios of methanogen-produced CH4 and CO2 are useful information for identifying and quantifying methanogenic pathways. Isotope ratio mass spectrometry combined with gas chromatography (GC/IRMS) is a very attractive tool for performing high-precision compound-specific isotope analysis. However, no GC/IRMS techniques have yet been available or been validated that give baseline separation of methanogen-produced CH4 and CO2 from N2/N-oxides and H2O vapor at ambient temperature and compatibility with analysis by mass spectrometry. METHODS: Microbe-produced CH4 and CO2 in headspace gases were separated from N2/N-oxides and H2O vapor in a single run on a GS-CarbonPLOT column at 35°C and with a maximum operating temperature of 120-140°C. The simultaneous characterization of CH4 and CO2 was then performed by GC/IRMS using an optimized backflush time to eliminate the interference from N2/N-oxides and H2O vapor, and by GC/MS due to there being no interference from O2 gas in the culture. RESULTS: GC/MS and GC/IRMS were used to calculate the ionization efficiency of CO2 as 8.22-8.84 times that of CH4 in GC/MS analysis, and it was deduced that the N-oxides, which can potentially interfere with δ(13)C analysis, were probably produced mainly in the source of the isotope ratio mass spectrometer. We also determined the aceticlastic methanogenic pathway. CONCLUSIONS: The established GC/MS and GC/IRMS techniques are suitable for characterizing the gaseous carbon-containing compounds produced by microbial cultures. Through high-precision carbon isotope analysis by GC/IRMS combined with low concentrations of (13)C-labelled substrates, the technique has great potential for identifying and quantifying methanogen-mediated carbon metabolic processes and pathways.

The genome characteristics and predicted function of methyl-group oxidation pathway in the obligate aceticlastic methanogens, Methanosaeta spp.

In this work, we report the complete genome sequence of an obligate aceticlastic methanogen, Methanosaeta harundinacea 6Ac. Genome comparison indicated that the three cultured Methanosaeta spp., M. thermophila, M. concilii and M. harundinacea 6Ac, each carry an entire suite of genes encoding the proteins involved in the methyl-group oxidation pathway, a pathway whose function is not well documented in the obligately aceticlastic methanogens. Phylogenetic analysis showed that the methyl-group oxidation-involving proteins, Fwd, Mtd, Mch, and Mer from Methanosaeta strains cluster with the methylotrophic methanogens, and were not closely related to those from the hydrogenotrophic methanogens. Quantitative PCR detected the expression of all genes for this pathway, albeit ten times lower than the genes for aceticlastic methanogenesis in strain 6Ac. Western blots also revealed the expression of fwd and mch, genes involved in methyl-group oxidation. Moreover, (13)C-labeling experiments suggested that the Methanosaeta strains might use the pathway as a methyl oxidation shunt during the aceticlastic metabolism. Because the mch mutants of Methanosarcina barkeri or M. acetivorans failed to grow on acetate, we suggest that Methanosaeta may use methyl-group oxidation pathway to generate reducing equivalents, possibly for biomass synthesis. An fpo operon, which encodes an electron transport complex for the reduction of CoM-CoB heterodisulfide, was found in the three genomes of the Methanosaeta strains. However, an incomplete protein complex lacking the FpoF subunit was predicted, as the gene for this protein was absent. Thus, F(420)H(2) was predicted not to serve as the electron donor. In addition, two gene clusters encoding the two types of heterodisulfide reductase (Hdr), hdrABC, and hdrED, respectively, were found in the three Methanosaeta genomes. Quantitative PCR determined that the expression of hdrED was about ten times higher than hdrABC, suggesting that hdrED plays a major role in aceticlastic methanogenesis.

Acyl homoserine lactone-based quorum sensing in a methanogenic archaeon.

Acyl homoserine lactone (AHL)-based quorum sensing commonly refers to cell density-dependent regulatory mechanisms found in bacteria. However, beyond bacteria, this cell-to-cell communication mechanism is poorly understood. Here we show that a methanogenic archaeon, Methanosaeta harundinacea 6Ac, encodes an active quorum sensing system that is used to regulate cell assembly and carbon metabolic flux. The methanogen 6Ac showed a cell density-dependent physiology transition, which was related to the AHL present in the spent culture and the filI gene-encoded AHL synthase. Through extensive chemical analyses, a new class of carboxylated AHLs synthesized by FilI protein was identified. These carboxylated AHLs facilitated the transition from a short cell to filamentous growth, with an altered carbon metabolic flux that favoured the conversion of acetate to methane and a reduced yield in cellular biomass. The transcriptomes of the filaments and the short cell forms differed with gene expression profiles consistent with the physiology. In the filaments, genes encoding the initial enzymes in the methanogenesis pathway were upregulated, whereas those for cellular carbon assimilation were downregulated. A luxI-luxR ortholog filI-filR was present in the genome of strain 6Ac. The carboxylated AHLs were also detected in other methanogen cultures and putative filI orthologs were identified in other methanogenic genomes as well. This discovery of AHL-based quorum sensing systems in methanogenic archaea implies that quorum sensing mechanisms are universal among prokaryotes.

Methanobacterium movens sp. nov. and Methanobacterium flexile sp. nov., isolated from lake sediment.

Two mesophilic methanogenic strains, designated TS-2(T) and GH(T), were isolated from sediments of Tuosu lake and Gahai lake, respectively, in the Qaidam basin, Qinghai province, China. Cells of both isolates were rods (about 0.3-0.5×2-5 µm) with blunt rounded ends and Gram-staining-positive. Strain TS-2(T) was motile with one or two polar flagella and used only H(2)/CO(2) for growth and methanogenesis. Strain GH(T) was non-motile, used both H(2)/CO(2) and formate and displayed a variable cell arrangement depending on the substrate: long chains when growing in formate (50 mM) or under high pressure H(2) and single cells under low pressure H(2). Phylogenetic analysis based on 16S rRNA gene sequences placed the two isolates in the genus Methanobacterium. Strain TS-2(T) was most closely related to Methanobacterium alcaliphilum NBRC 105226(T) (96% 16S rRNA gene sequence similarity). Phylogenetic analysis based on the alpha subunit of methyl-coenzyme M reductase also supported the affiliation of the two isolates with the genus Methanobacterium. DNA-DNA relatedness between the isolates and M. alcaliphilum DSM 3387(T) was 39-53%. Hence we propose two novel species, Methanobacterium movens sp. nov. (type strain TS-2(T)=AS 1.5093(T)=JCM 15415(T)) and Methanobacterium flexile sp. nov. (type strain GH(T)=AS 1.5092(T)=JCM 15416(T)).