Bioaugmented constructed wetlands for efficient saline wastewater treatment with multiple denitrification pathways.

Six laboratory-scale constructed wetlands (CWs) were used to quantify the nitrogen removal (NR) capacity in the treatment of saline wastewater at high (6:1) and low (2:1) carbon-nitrogen ratios (C/N), with and without bioaugmentation of aerobic-denitrifying bacterium. Sustained high-efficiency nitrification was observed throughout the operation. However, under different C/N ratios, although the bioaugmentation of aerobic-denitrifying bacterium promoted the removal of NO3--N and TN, there were still great differences in denitrification. Molecular biology experiments revealed ammonia-oxidizing archaea, together with the Nitrosomonas and Nitrospira, led to highly efficient nitrification. Furthermore, aerobic-denitrifying bacterium and sulfur-driven denitrifiers were the core denitrification groups in CWs. By performing these combined experiments, it was possible to determine the optimal CW design and the most relevant NR processes for the treatment of salty wastewater. The results suggest that the bioaugmentation of salt-tolerant functional bacteria with multiple NR pathways are crucial for the removal of salty wastewater pollutants.

Predicting mortality of patients with acute kidney injury in the ICU using XGBoost model.

PURPOSE: The goal of this study is to construct a mortality prediction model using the XGBoot (eXtreme Gradient Boosting) decision tree model for AKI (acute kidney injury) patients in the ICU (intensive care unit), and to compare its performance with that of three other machine learning models. METHODS: We used the eICU Collaborative Research Database (eICU-CRD) for model development and performance comparison. The prediction performance of the XGBoot model was compared with the other three machine learning models. These models included LR (logistic regression), SVM (support vector machines), and RF (random forest). In the model comparison, the AUROC (area under receiver operating curve), accuracy, precision, recall, and F1 score were used to evaluate the predictive performance of each model. RESULTS: A total of 7548 AKI patients were analyzed in this study. The overall in-hospital mortality of AKI patients was 16.35%. The best performing algorithm in this study was XGBoost with the highest AUROC (0.796, p < 0.01), F1(0.922, p < 0.01) and accuracy (0.860). The precision (0.860) and recall (0.994) of the XGBoost model rank second among the four models. CONCLUSION: XGBoot model had obvious advantages of performance compared to the other machine learning models. This will be helpful for risk identification and early intervention for AKI patients at risk of death.

Analysis of adult disease characteristics and mortality on MIMIC-III.

PURPOSE: To deeply analyze the basic information and disease information of adult patients in the MIMIC-III (Medical Information Mart for Intensive Care III) database, and provide data reference for clinicians and researchers. MATERIALS AND METHODS: Tableau2019.1.0 and Navicat12.0.29 were used for data analysis and extraction of disease distribution of adult patients in the MIMIC-III database. RESULT: A total of 38,163 adult patients were included in the MIMIC-III database. Only 38,156 patients with the first diagnosis were selected. Among them, 21,598 were males accounting for 56.6% the median age was 66 years (Q1-Q3: 53-78), the median length of a hospital stay was 7 days (Q1-Q3: 4-12), and the median length of an ICU stay was 2.1 days (Q1-Q3: 1.2-4.1). Septicemia was the disease with the highest mortality rate among patients and the total mortality rate was 48.9%. The disease with the largest number of patients at the last time was other forms of chronic ischemic heart disease. CONCLUSION: By analyzing the patients' basic information, the admission spectrum and the disease morbidity and mortality can help more researchers understand the MIMIC-III database and facilitate further research.

Effects of substrate type on denitrification efficiency and microbial community structure in constructed wetlands.

Three constructed wetland systems were established to treat saline sewage via high-porosity ceramsite, activated carbon, and low-porosity sand: A (ceramsite + activated carbon + sand), B (sand + activated carbon + ceramsite), and C (sand). The distribution of dissolved oxygen in these systems varied with different filling methods with the best removal efficiency of ammonium nitrogen and total nitrogen observed in system B (97.4 and 96.2%, respectively). The 16S rDNA amplicon sequencing results showed that all the systems had a high abundance of salt-tolerant denitrifiers, and the filling method significantly impacted denitrifying bacteria (e.g., Vibrio and Planctomyces) in the substrate. System B had more diverse dissolved oxygen conditions than system A and showcased aerobic nitrification-denitrification and anaerobic ammonium oxidation pathways. Therefore, the use of substrates with different porosities can improve the dissolved oxygen supply and enhance nitrogen removal efficiency in constructed wetlands.

Isolation and identification of a salt-tolerant aerobic denitrifying bacterial strain and its application to saline wastewater treatment in constructed wetlands.

A salt-tolerant aerobic denitrifying bacterium, Zobellella denitrificans strain A63, was isolated, and its effects on the efficiency of denitrification of saline wastewater and the denitrifying microbial community structure in the matrix were studied in vertical-flow constructed wetlands (VFCWs). In a VFCW system with strain A63, the removal efficiencies of NH4+-N, NO3--N, and total nitrogen reached 79.2%, 95.7%, and 89.9%, respectively. Quantitative PCR analysis indicated that the amoA gene from ammonia-oxidizing archaea (AOA) was highly abundant, whereas amoA from ammonia-oxidizing bacteria and nxrA from nitrite-oxidizing bacteria were lowly abundant because of the influent salinity, irrespective of whether strain A63 was added. However, the addition of strain A63 significantly increased the abundance of nirK in the top layer of the VFCW. Therefore, AOA-driven partial nitrification and aerobic denitrification by strain A63 occurred in VFCWs. Our findings suggest that adding salt-tolerant denitrifying strains to constructed wetlands can enhance denitrification for saline wastewater treatment.

Effects of Kangquan Recipe on sex steroids and cell proliferation in rats with benign prostatic hyperplasia.

OBJECTIVE: To investigate the effects of Kangquan Recipe (KQR) on sex steroids and cell proliferation in an experimental benign prostatic hyperplasia (BPH) model in rats. METHODS: Seventy-two SD rats were randomly divided into six groups: the normal group, the model group, the finasteride group, and the low-, middle-, and high-dose KQR groups, 12 in each group. Except those in the normal group, the rats were injected with testosterone after castration for the establishment of BPH model and then given respectively with normal saline, finasteride, and low-, middle-, and high-dose of KQR for 30 days. The levels of plasma testosterone (T) and estradiol (E(2)) were determined by enzyme-linked immunosorbent assay (ELISA), and the mRNA expression ) of proliferating cell nuclear antigen (PCNA) in prostate tissue was detected by reverse transcription-polymerase chain reaction (RT-PCR) after administration. RESULTS: Compared with the model group, the prostate weight, the plasma T, and the mRNA expression of PCNA were significantly lower, and the plasma E(2) and the ratio of E(2)/T were higher in the three KQR groups (P<0.05 or P<0.01). There was no significant difference in the prostate weight, plasma T and E(2), and ratio of E(2)/T among the finasteride group and the three KQR groups (P>0.05). The mRNA expressions of PCNA were significantly higher in the middle- and low-dose of KQR groups than those in the finasteride group (P<0.05). CONCLUSION: KQR shows multitarget effects on experimental BPH rats, and the mechanism might be related with regulating the balance of plasma T and E(2) and decreasing the PCNAmRNA expression in prostate tissue to restrain cell proliferation in a dose-dependent manner.