Nitrite accumulation in activated sludge through cyclic anaerobic exposure with acetate.

Achieving nitrite accumulation still remains challenging for efficient short-cut biological nitrogen removal in municipal wastewater treatment. To tackle the problem of insufficient carbon in incoming wastewater for biological nutrient removal, a return activated sludge (RAS) fermentation method has been proposed and demonstrated to enable producing supplemental volatile fatty acids (VFAs) and enhance biological phosphorus removal via sludge cycling between mainstream and a sidestream anaerobic reactor. However, the impacts of long anaerobic exposure with acetate on nitrifying bacteria, known as the aerobic chemoautotrophic microorganisms, remains unexplored. In this study, the activated sludge underwent a cyclic anaerobic treatment with the addition of acetate (Ac), the effects on nitrification rate, abundance and microdiversity of nitrifying communities were comprehensively assessed. Firstly, batch activity tests proved the direct addition of high acetate (above 1000 mg/L) could cause inhibition on the nitrification rate, moreover, the inhibitory effect was stronger on nitrite-oxidizing bacteria (NOB) activity than that of ammonia-oxidizing bacteria (AOB). Then, a sequencing batch reactor (SBR) was applied to test the nitrogen conversion performance for low-strength ammonium wastewater. Nitrite accumulation could be achieved via the cyclic anaerobic exposure with 1000-5000 mg Ac/L. The maximum effluent concentration of nitrite was 40.8 ± 3.5 mg N/L with nitrite accumulation ratio (NAR) of 67.6 ± 3.5%. The decrease in NOB activity (72.7%) was greater than AOB of 42.4%, promoting nitrite accumulation via nitritation process. Furthermore, the cyclic anaerobic exposure with acetate can largely reshape the nitrifying communities. As the dominant AOB and NOB, the abundance of Nitrosomonas and Nitrospira were both decreased with species-level microdiversity in the nitrifying communities. However, the heterotrophic microorganism, Thauera, were found to be highly enriched (from 0 to 17.3%), which may act as the potential nitrite producer as proved by the increased nitrate reduction gene abundance. This study can provide new insights into achieving mainstream nitrite accumulation by involving sidestream RAS fermentation towards efficient wastewater treatment management.

Preparation of a Coal-Based MoS2/SiO2/GO Composite Catalyst and Its Performance in the Photocatalytic Degradation of Wastewater and Hydrogen Production.

Photocatalytic degradation of wastewater and the simultaneous production of hydrogen (H2) is a green and efficient method to solve energy and environmental problems. In this paper, coal-based SiO2/GO with a stable structure was prepared by a modified Hummers oxidation method, and then, a lotus-shaped composite photocatalyst, MoS2/SiO2/GO, was prepared by in situ loading of flower cluster MoS2 from sodium molybdate reduction onto SiO2/GO. Its photocatalytic degradation of wastewater and H2 production properties were investigated while characterizing the material structure. The results show that SiO2/GO as a carrier not only ensures adequate dispersion of MoS2 but also enhances the visible-light response of the composite catalyst. In addition, it can also hinder the recombination of photogenerated electrons and holes in MoS2 and act as an electron transport channel in composite catalysts. MoS2/SiO2/GO exhibits much higher photocatalytic degradation of wastewater and H2 production capacity than MoS2: after 180 min of reaction, the CODcr removal of wastewater increased from 45.6% for MoS2 to 84.2% for MoS2/SiO2/GO and the H2 yield reached 233.4 µmol. The goal of degrading wastewater while producing H2 more economically has been tentatively achieved, although not to the extent required for industrialization.

Effects of a continuous nursing care model on elderly patients with total hip arthroplasty: a randomized controlled trial.

BACKGROUND: Continuous nursing care (CNC) is an extended service based on meeting the needs of discharged patients for post-discharge treatment and rehabilitation. This research aimed to investigate the effects of CNC on older patients with total hip arthroplasty and to offer a scientific basis for improving the prognosis. METHODS: A total of 134 patients with total hip arthroplasty were randomly divided into the control group (n = 67) and the intervention group (n = 67). The control group was treated by conventional nursing care and the intervention group was treated by CNC. Harris hip score, Barthel index, the activities of daily living (ADL) scale, self-rating depression scale (SDS) and self-rating anxiety scale (SAS) in these two groups were evaluated. Demographic characteristics between groups were analyzed by unpaired t test. The observation indexes between groups were assessed by two-way ANOVA test followed by Tukey's multiple comparisons test. RESULTS: The scores of Harris hip score, Barthel index, ADL, SDS and SAS in the intervention group after intervention and after follow-up were better than the intervention group before intervention (all p < 0.01). Meanwhile, the scores of Harris hip score, Barthel index, ADL, SDS and SAS in the intervention group were better than the control group both after intervention and after follow-up (all p < 0.01). CONCLUSION: In conclusion, CNC showed better efficacy than conventional nursing care in promoting hip joint function recovery, improving quality of life and alleviating anxiety and depression for older patients with total hip arthroplasty.

A rare case of bladder cancer that metastasized to brain, heart, and lung lymph nodes benefited from immunotherapy.

Bladder cancer is a common malignant tumor of the genitourinary system, with the primary cause of death being metastasis. The most common metastatic sites are the lymph nodes, liver, lung, bone, peritoneum, pleura, kidney, adrenal gland, and the intestine. Brain and heart metastases are rare. In this report, we describe a patient who had pulmonary lymph node metastases more than a year after being diagnosed with bladder cancer, followed by brain and cardiac metastases more than two years later. Following the failure of standard first-line chemotherapy, the patient accepted 6 cycles of tislelizumab immunotherapy. The re-examination revealed that the bilateral frontal brain metastases had vanished, the right temporal lobe metastases had been greatly decreased, the neurological symptoms had been alleviated, and the cardiac metastases had disappeared. This is a rare clinical case with encouraging effects of tislelizumab and can serve as a model for the treatment of similar patients.

Redirecting carbon to recover VFA to facilitate biological short-cut nitrogen removal in wastewater treatment: A critical review.

Wastewater treatment plants (WWTPs) are facing a great challenge to transition from energy-intensive to carbon-neutral and energy-efficient systems. Biological nutrient removal (BNR) can be severely impacted by carbon limitation, particularly for wastewater with a low carbon-to-nitrogen (C/N) ratio, which can significantly increase the operational costs. Waste activated sludge (WAS) is a valuable byproduct of WWTPs, as it contains high levels of organic matter that can be utilized to improve BNR management by recovering and reusing the fermentative volatile fatty acids (VFAs). This review provides a comprehensive examination of the recovery and reuse of VFAs in wastewater management, with a particular focus on advancing the preferable biological short-cut nitrogen removal process for carbon-insufficient municipal wastewaters. First, the method of carbon redirection for recovering VFAs was reviewed. Carbon could be captured through the two-stage A/B process or via sludge fermentation with different sludge pretreatment and process control strategies to accelerate sludge hydrolysis and inhibit methanogens to enhance VFA production. Second, VFAs can support the metabolism of autotrophic N-cycling microorganisms involved in wastewater treatment, such as AOB, NOB, anammox, and comammox bacteria. However, VFAs can also cause inhibition at high concentrations, leading to the partition of AOB and NOB; and can promote partial denitrification as an efficient carbon source for heterotrophic denitrifiers. Third, the lab- and pilot-scale engineering practices with different configurations (i.e., A2O, SBR, UASB) were summarized that have shown the feasibility of utilizing the fermentate to achieve superior nitrogen removal performance without the need for external carbon addition. Lastly, the future perspectives on leveraging the relationships between mainstream and sidestream, nitrogen and phosphorus, autotrophs and heterotrophs were given for sustainable and efficient BNR management.

Effects of compound Kushen injection on pathology and angiogenesis of tumor tissues.

Effects of compound Kushen injection on pathology and angiogenesis of tumor tissues were investigated. Forty nude mice were used to establish the liver cancer model of nude mice, and were divided into model group (n=10), low-dose compound Kushen injection group (n=10), medium-dose compound Kushen injection group (n=10) and high-dose compound Kushen injection group (n=10). When the tumor volume reached 0.5 cm3, 200, 400 and 600 µl of compound Kushen were injected into the mice of the low-, medium- and high-dose compound Kushen injection groups, respectively, for 3 consecutive days; while 400 µl normal saline were injected into the mice of the model group. At 9 days after treatment, the mice were sacrificed, and the tumor was taken and weighed. The tumor inhibition rate was calculated, α-smooth muscle actin (α-SMA) and cluster of differentiation 31 (CD31) were detected via immunohistochemistry, and the vascular maturity index (VMI) and microvessel density (MVD) were also detected. With the increase of compound Kushen injection dose, the tumor mass was decreased significantly (P<0.05), and the tumor inhibition rate was obviously increased (P<0.05). In the model group, the nuclei were large and deeply stained, and there were many mitotic figures, and more small blood vessels could be seen. In the three Kushen injection groups, the number of mitotic figures was slightly decreased, and the vascular distribution was reduced. With the increase of compound Kushen injection dose, MVD of transplanted tumor was decreased significantly, but VMI was increased significantly (P<0.05). Compound Kushen injection can reduce the angiogenesis in tumor tissues and play a role in inhibiting tumor growth. Therefore, anti-angiogenesis may be one of the important mechanisms of compound Kushen injection in inhibiting tumor growth.