Hydrogeochemical differences drive distinct microbial community assembly and arsenic biotransformation in unconfined and confined groundwater of the geothermal system.

High­arsenic (As) groundwater in geothermal aquifers poses a serious threat to public health. Assembly processes governing groundwater microbial community related to As biotransformation are still unexplored in geothermal groundwater across different aquifers. To fill this gap, groundwater microorganisms, community assembly processes, and microbially metabolic coupling of carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and arsenic (As) were investigated in unconfined and confined groundwater in the thermal reservoirs of the Guide Basin. The difference in groundwater hydrogeochemicals led to the heterogeneity of the microbial community and microbially mediated C, N, P, S, and As cycling between unconfined and confined groundwater. Higher temperature and As concentrations, low nutrient supply, and reduced conditions in confined groundwater supported stronger interspecific coexistence and environmental selection, thus promoting the proliferation of As-resistant microorganisms (ARMs) and simplifying the community assemblage. Abundant available nutrient supply and oxidizing conditions supported an increased species diversity and metabolic functionality in unconfined groundwater. S oxidizers, C fixation, and C degradation bacteria potentially contributed to the decreased As concentrations in unconfined groundwater. However, ARMs, ammonification, and anaerobic ammonia-oxidizing bacteria potentially caused As mobilization in confined groundwater. Overall, our results give a comprehensive insight into the interaction between As and microorganisms in geothermal groundwater.

[Expression Levels and Regulation of Selenoprotein Genes in Patients With Coronavirus Disease 2019].

Objective To investigate the expression levels of selenoprotein genes in the patients with coronavirus disease 2019 (COVID-19) and the possible regulatory mechanisms.Methods The dataset GSE177477 was obtained from the Gene Expression Omnibus,consisting of a symptomatic group (n=11),an asymptomatic group (n=18),and a healthy control group (n=18).The dataset was preprocessed to screen the differentially expressed genes (DEG) related to COVID-19,and gene ontology functional annotation and Kyoto encyclopedia of genes and genomes enrichment analysis were performed for the DEGs.The protein-protein interaction network of DEGs was established,and multivariate Logistic regression was employed to analyze the effects of selenoprotein genes on the presence/absence of symptoms in the patients with COVID-19.Results Compared with the healthy control,the symptomatic COVID-19 patients presented up-regulated expression of GPX1,GPX4,GPX6,DIO2,TXNRD1,SELENOF,SELENOK,SELENOS,SELENOT,and SELENOW and down-regulated expression of TXNRD2 and SELENON (all P<0.05).The asymptomatic patients showcased up-regulated expression of GPX2,SELENOI,SELENOO,SELENOS,SELENOT,and SELENOW and down-regulated expression of SELP (all P<0.05).The results of multivariate Logistic regression analysis showed that the abnormally high expression of GPX1 (OR=0.067,95%CI=0.005-0.904,P=0.042) and SELENON (OR=56.663,95%CI=3.114-856.999,P=0.006) was the risk factor for symptomatic COVID-19,and the abnormally high expression of SELP was a risk factor for asymptomatic COVID-19 (OR=15.000,95%CI=2.537-88.701,P=0.003).Conclusions Selenoprotein genes with differential expression are involved in the regulation of COVID-19 development.The findings provide a new reference for the prevention and treatment of COVID-19.

Metabolic coupling of arsenic, carbon, nitrogen, and sulfur in high arsenic geothermal groundwater: Evidence from molecular mechanisms to community ecology.

Groundwater arsenic (As) poses a global environmental problem and is regulated by complex biogeochemical processes. However, the As biogeochemistry and its metabolic coupling with carbon (C), nitrogen (N), and sulfur (S) in high As geothermal groundwater remain unclear. Here, we reported significant shifts in the geothermal groundwater microbiome and its functional ecological clusters along the flow path with increased As levels and dynamic As-C-N-S biogeochemical cycle from the Guide Basin, China. Strong associations among As(III), NH4+, HCO3-, and corresponding functional microbial taxa suggest that microbe-mediated As transformation, ammonification, and organic carbon biodegradation potentially contributed to the As mobilization in the discharge area. And As oxidizers (coupling with denitrification or carbon fixation) and S oxidizers were closely linked to the transformation of As(III) to immobile As(V) in the recharge area. Our study provides a comprehensive insight into the complex microbial As-C-N-S coupling network and its potential role in groundwater As mobilization under hydrological disturbances.

Effect of melting combined with ice recrystallization on porous starch preparation: Pore-forming properties, granular morphology, functionality, and multi-scale structures.

In this work, critical melting (CM) combined with freeze-thawing treatment (FT, freezing at -20 â„ƒ and -80 â„ƒ, respectively) was used to prepare porous starch. The results showed that CM combined with the slow freezing rate (-20 â„ƒ) can prepare porous starch with characteristics of grooves and cavities, while combined with the rapid freezing rate (-80 â„ƒ) can prepare with holes and channels, especially after repeating FT cycles. Compared with the native counterpart, the specific surface area, pore volume, and average diameter of CMFT-prepared porous starch were significantly increased to 4.07 m2/g, 7.29 cm3/g × 10-3, and 3.57 nm, respectively. CMFT significantly increased the thermal stability of starch, in which the To, Tp, and Tc significantly increased from 63.32, 69.62, and 72.90 (native) to ∼69, 72, and 76 °C, respectively. CMFT significantly increased water and oil absorption of porous starch from 91.20 % and 72.00 % (native) up to ∼163 % and 94 %, respectively. Moreover, CMFT-prepared porous starch had a more ordered double-helical structure, which showed in the significantly increased relative crystallinity, semi-crystalline lamellae structure, and the proportion of the double helix structure of starch. The synergistic effect of melting combined with ice recrystallization can be used as an effective way to prepare structure-stabilized porous starch.

[A Prediction Model for Human Immunodeficiency Virus Infection and Mother-to-Child Transmission Based on the Expression Levels of Selenoprotein Genes].

Objective To study the expression of selenoprotein genes in human immunodeficiency virus(HIV)infection and its mother-to-child transmission,so as to provide a theoretical basis for the prevention,diagnosis,and treatment of acquired immunodeficiency syndrome.Methods The dataset GSE4124 was downloaded from the Gene Expression Omnibus(GEO).Two groups of HIV-positive mothers(n=25)and HIV-negative mothers(n=20)were designed.HIV-positive mothers included a subset of transmitter(TR)mothers(n=11)and non-transmitter(NTR)mothers(n=14).Then,t-test was carried out to compare the expression levels of selenoprotein genes between the four groups(HIV-positive vs. HIV-negative,NTR vs. HIV-negative,TR vs. HIV-negative,TR vs. NTR).Univariate and multivariate Logistic regression were adopted to analyze the effects of differentially expressed genes on HIV infection and mother-to-child transmission.R software was used to establish a nomogram prediction model and evaluate the model performance.Results Compared with the HIV-negative group,HIV-positive,NTR,and TR groups had 8,5 and 8 down-regulated selenoprotein genes,respectively.Compared with the NTR group,the TR group had 4 down-regulated selenoprotein genes.Univariate Logistic regression analysis showed that abnormally high expression of GPX1,GPX3,GPX4,TXNRD1,TXNRD3,and SEPHS2 affected HIV infection and had no effect on mother-to-child transmission.The multivariate Logistic regression analysis showed that the abnormally high expression of TXNRD3(OR=0.032,95%CI=0.002-0.607,P=0.022)was positively correlated with HIV infection.As for the nomogram prediction model,the area under the receiver-operating characteristic curve for 1-year survival of HIV-infected patients was 0.840(95%CI=0.690-1.000),and that for 3-year survival of HIV-infected patients was 0.870(95%CI=0.730-1.000).Conclusions Multiple selenoprotein genes with down-regulated expression levels were involved in the regulation of HIV infection and mother-to-child transmission.The abnormal high expression of TXNRD3 was positively correlated with HIV infection.The findings provide new ideas for the prevention,diagnosis,and treatment of acquired immunodeficiency syndrome.

Effects of enhanced starch-xanthan gum synergism on their physicochemical properties, functionalities, structural characteristics, and digestibility.

The limited and unstable interactions between potato starch (PS) and xanthan gum (XG) by simple mixing (SM) lead it difficult to induce substantial changes in starchy products. Structural unwinding and rearrangement of PS and XG by critical melting and freeze-thawing (CMFT) were used to promote PS/XG synergism, and the physicochemical, functionalities, and structural properties were investigated. Compared to "Native" and SM, CMFT promoted the formation of large clusters with a rough granular surface and wrapped by a matrix composed of released soluble starches and XG (SEM), thus making the composite more compact to thermal processes, such as the significantly decreased WSI and SP, and increased the melting temperatures. The enhanced synergism of PS/XG after CMFT effectively decreased the breakdown viscosity from ~3600 (Native) to ~300 mPa·s and increased the final viscosity from ~2800 (Native) to ~4800. CMFT significantly increased the functional properties of PS/XG composite, including water/oil absorptions and resistant starch content. CMFT caused the partial melting and loss of large packaged structures in starch (XRD, FTIR, and NMR), and the melting and the loss of crystalline structure controlled at approximately 20 % and 30 %, respectively, are the most effective for promoting PS/XG interaction.

Response of microbial taxonomic and nitrogen functional attributes to elevated nitrate in suburban groundwater.

Anthropogenic nitrogen (N) input has led to elevated levels of nitrate nitrogen (NO3--N) in the groundwater. However, insights into the responses of the microbial community and its N metabolic functionality to elevated NO3--N in suburban groundwater are still limited. Here, we explored the microbial taxonomy, N metabolic attributes, and their responses to NO3--N pollution in groundwaters from Chaobai River catchment (CR) and Huai River catchment (HR) in Beijing, China. Results showed that average NO3--N and NH4+-N concentrations in CR groundwater were 1.7 and 3.0 folds of those in HR. NO3--N was the dominant nitrogen specie both in HR and CR groundwater (over 80 %). Significantly different structures and compositions of the microbial communities and N cycling gene profiles were found between CR groundwater and HR groundwater (p < 0.05), with CR groundwater harboring significantly lower microbial richness and abundance of N metabolic genes. However, denitrification was the dominant microbial N cycling process in both CR and HR groundwater. Strong associations among NO3--N, NH4+-N, microbial taxonomic, and N functional attributes were found (p < 0.05), suggesting denitrifiers and Candidatus_Brocadia might serve as potential featured biomarkers for the elevated NO3--N and NH4+-N concentration in groundwater. Path analysis further revealed the significant effect of NO3--N on the overall microbial N functionality and microbial denitrification (p < 0.05). Collectively, our results provide field evidence that elevated levels of NO3--N and NH4+-N under different hydrogeologic conditions had a significant effect on the microbial taxonomic and N functional attributes in groundwater, with potential implications for improving sustainable N management and risk assessment of groundwater.

Minimally invasive thoracoscopic left atrial appendage occlusion compared with transcatheter left atrial appendage closure for stroke prevention in recurrent nonvalvular atrial fibrillation patients after radiofrequency ablation: a prospective cohort study.

BACKGROUND: Tanscatheter left atrial appendage (LAA) closure and minimally invasive thoracoscopic LAA occlusion are local interventions of LAA for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). However, the safety and efficacy of these methods have not been compared. This prospective cohort study aimed to assess the safety and efficacy of those two treatment approaches for stroke prevention in NVAF patients. METHODS: Two hundred and nine recurrent NVAF patients who received radiofrequency ablation were enrolled. These patients were treated with transcatheter LAA closure or thoracoscopic LAA occlusion. The patients were followed up from the first postoperative day and evaluated for efficacy endpoints (stroke/transient ischemic attack (TIA), systemic embolism (SE), and death) and a safety endpoint (bleeding events). Perioperative complications were recorded. RESULTS: After a median follow-up of 1.8 years (383 patient-years), the overall rate of the composite efficacy endpoints was similar between the two groups (3.8 vs. 2.7 events per 100 patient-years; HR = 0.71; 95% CI: 0.225-2.237; P = 0.559). However, regarding primary safety endpoint, there were 1.5 bleeding events per 100 patient-years in the thoracoscopic LAA occlusion group, compared with 6.4 in transcatheter LAA closure group (HR = 0.246; 95% CI: 0.074-0.819; P = 0.022). The incidence of operative complications was 3/138 (2.17%) in thoracoscopic LAA occlusion group and 1/71 (1.41%) in transcatheter LAA closure group. CONCLUSIONS: Thoracoscopic LAA occlusion and transcatheter LAA closure have similar efficacy in preventing stroke in NVAF patients. However, the thoracoscopic group had fewer bleeding events than the transcatheter group, but the former group required a longer hospital stay.

Model for end-stage liver disease and pneumonia: An improved scoring model for critically ill cirrhotic patients with pneumonia.

BACKGROUND/AIMS: Critically ill patients with cirrhosis with pneumonia are at an increased risk for mortality. Only a few accurate predictive models are existing specific to these patients. The aim of the present study was to compare the existing prognostic models and to develop an improved mortality risk model for patients with cirrhosis and pneumonia. MATERIALS AND METHODS: A total of 231 patients were enrolled in our study (70% training and 30% validation cohorts). All participants were followed up for at least 21 days. Model for End-stage Liver Disease and Pneumonia (MELD-P) was derived by the Cox proportional hazards model. The performances of prognostic scoring systems were compared by calculation of the area under the receiver operating characteristic (AUROC) curve. RESULTS: MELD-P showed better discriminative capabilities than existing scoring systems. Four clinical variables, including loge bilirubin (hazard ratio (HR) 1.29, 95% confidence interval (CI) 1.01-1.73), loge international normalized ratio (HR 3.57, 95% CI 1.30-9.78), loge pulse oxygen saturation/fraction of inspired oxygen (HR 0.38, 95% CI 0.14-0.99), and vasopressors used (HR 3.72, 95% CI 1.85-7.49), were considered as independent prognostic values associated with 21-day mortality. MELD-P had AUROC curve values of 0.78 (95% CI 0.71-0.84) in predicting in-hospital mortality, 0.78 (95% CI 0.70-0.84) at 21-day, 0.88 (95% CI 0.82-0.93) at 14-day, and 0.87 (95% CI 0.81-0.92) at 7-day. A similar result was obtained in validation cohort. CONCLUSION: MELD-P, as the first model specifically designed to evaluate the risk of mortality in critically ill patients with cirrhosis and pneumonia, performs well on the mortality assessment of short-term mortality.

Prognostic value of international normalized ratio to albumin ratio among critically ill patients with cirrhosis.

BACKGROUND AND AIM: Critically ill patients with cirrhosis are at an increased risk of mortality. Our study aimed to externally validate the ability of the prothrombin time-international normalized ratio to albumin ratio (PTAR), an objective and simple scoring system, to predict 90-day mortality in critically ill patients with cirrhosis. PATIENTS AND METHODS: A total of 865 patients were entered into the study, and all the participants were followed up for at least 90 days. Clinical parameters on the first day of intensive care unit admission were included to compare survivors with nonsurvivors. RESULTS: After multivariable adjustment, the association between the risk of 90-day mortality and PTAR remained statistically significant with a hazard ratio of 2.71 (95% confidence interval: 1.99-3.68). The PTAR score showed good discrimination ability for predicting 90-day mortality with an area under receiver operating characteristic curve of 0.72 (95% confidence interval: 0.68-0.75). To improve its feasibility, we regrouped the PTAR scores into three levels of risk (low risk: <0.55, intermediate risk: 0.55-1.00, and high risk: ≥1.00); the 90-day mortality rates were 20.1% (74/368), 41.7% (168/403), and 73.4% (69/94), respectively. CONCLUSION: The PTAR score system is a convenient and practical tool for predicting the prognosis of critically ill patients with cirrhosis.