[Chemical Characteristics and Genetic Analysis of Karst Groundwater in the Beijing Xishan Area].

As an important water supply source in Beijing， karst groundwater has played an irreplaceable role in the security of urban water supply and ecological environment protection in the past 70 years. The Xishan karst groundwater system， located in the upper reaches of western Beijing， belongs to ecological conservation areas. There are several centralized water supply fields in this area. In this study， the Xishan karst groundwater system was taken as the research object. A total of 120 karst groundwater samples in this area were investigated by using statistical analysis， ion ratio， and principal component analysis （PCA） methods to explore the spatial distribution characteristics and formation mechanism of groundwater hydrochemistry. The research results showed that： ① the groundwater quality of the Xishan system was generally good， with the characteristics of neutral pH and low salinity. A total of 84.17% of the water samples were classified as hard water. The chemical type of groundwater was mainly HCO3-Ca·Mg. ② The chemical composition of groundwater was mainly affected by the water-rock interaction， and the weathering source of rock was mainly the dissolution of carbonate. ③ The results of principal component analysis showed that 34.41% of the chemistry formation of groundwater could be explained by carbonate dissolution， 27.33% by rock salt and evaporate dissolution， 11.76% by aquifer sediment dissolution， and 10.30% by domestic sewage discharge. From the recharge area to the runoff area and then to the discharge area， the TH and TDS gradually increased. Coal mining drainage and human activities were the main factors that caused groundwater degradation and variable hydrochemical types in the piedmont. In the future， it is necessary to further strengthen environmental governance， control point and non-point source pollution， and continuously monitor key areas to provide scientific support for ecological and environmental protection.

The Prognostic Model Established by the Differential Expression Genes Based on CD8+ T Cells to Evaluate the Prognosis and the Response to Immunotherapy in Osteosarcoma.

Osteosarcoma (OS) is a malignant tumor with an extremely poor prognosis, especially in progressive patients. Immunotherapy based on immune checkpoint inhibitors (ICIs) is considered to be a promising treatment option for OS. Due to tumor heterogeneity, only a minority of patients benefit from immunotherapy. Therefore, it is urgent to explore a model that can accurately assess the response of OS to immunotherapy. In this study, we obtained the single-cell RNA sequencing datasets of OS patients from public databases and defined 34 cell clusters by dimensional reduction and clustering analysis. PTPRC was applied to identify immune cell clusters and nonimmune cell clusters. Next, we performed clustering analysis on the immune cell clusters and obtained 25 immune cell subclusters. Immune cells were labeled with CD8A and CD8B to obtain CD8+ T cell clusters. Meanwhile, we extracted the differentially expressed genes (DEGs) of CD8+ T cell clusters and other immune cell clusters. Furthermore, we constructed a prognostic model (CD8-DEG model) based on the obtained DEGs of CD8+ T cells, and verified the excellent predictive ability of this model for the prognosis of OS. Moreover, we further investigated the value of the CD8-DEG model. The results indicated that the risk score of the CD8-DEG model was an independent risk factor for OS patients. Finally, we revealed that the risk score of the CD8-DEG model correlates with the immune profile of OS and can be used to evaluate the response of OS to immunotherapy. In conclusion, our study revealed the critical role of CD8 cells in OS. The risk score model based on CD8-DEGs can provide guidance for prognosis and immunotherapy of OS.

Comparison of the effectiveness and safety of unilateral and bilateral percutaneous vertebroplasty for osteoporotic vertebral compression fractures: A protocol for systematic review and meta-analysis.

BACKGROUND: The objective of this study was to compare the efficacy of lateral and bilateral percutaneous vertebroplasty (PVP) in treating osteoporotic vertebral compression fractures (OVCFs). METHODS: A comprehensive literature search was performed using PubMed, Cochrane Library, EMBASE, CMB, CNKI, Wanfang, and VIP databases between January 2014 and December 2020. The clinical efficacy of the 2 approaches was evaluated by comparing perioperative outcomes (operation time, X-ray exposure time, volume of injected cement), clinical outcomes (degree of vertebral height restoration, improvement of Cobb angle, visual analogue scale score, and Oswestry Disability Index scores), and operation-related complications (rate of cement leakage, adjacent vertebral fracture rate, and nerve root stimulation). Data were analyzed using RevMan 5.3.3 and Stata 15.1. RESULTS: A total of 237 related articles were retrieved, and 17 randomized controlled trials were included. Meta-analysis results showed that compared to bilateral PVP, unilateral PVP led to decreased operation times (mean difference [MD] = -15.24, 95% confidence interval [CI]: [-17.77, -12.70], P < .05), decreased X-ray exposure time (MD-8.94, 95% CI[-12.08,-5.80]; P < .01), decreased volumes of injected cement (MD-1.57, 95% CI[-2.00,-1.14]; P < .05), and lower incidence of cement leakage (risk ratio [RR] = 0.6,95% CL[0.48,0.77], P < .01). Patients that underwent unilateral PVP experienced more effective pain relief at the last follow-up (MD-0.09, 95% CI [-0.15,-0.03];P=.006 < .05) and had a low degree of vertebral height restoration (MD-0.38, 95% CL [-0.71, -0.06]; P=.02 < .05). However, no differences in adjacent vertebral fractures (RR 1.19, 95% CI [0.78,1.82]; P = .41 > .01), nerve root stimulation (RR 1.98, 95% CI [0.22, 17.90]; P = .54 > .01), improvement of Cobb angle (MD = -0.18, 95% CI [-0.49, 0.13], P = .26 > .01), and improvement of ODI score (MD = 0.22, 95% CI[-0.37, 0.80], P > .05) were found between the 2 approaches. CONCLUSIONS: Although both unilateral and bilateral PVP can improve the quality of life of this patient population by managing pain effectively, unilateral PVP offers more benefits, including shorter operation time and less fluoroscopy, and should be recommended in clinical practice for OVCFs.

Low-Temperature Selective Catalytic Reduction DeNOX and Regeneration of Mn-Cu Catalyst Supported by Activated Coke.

The activated coke is a promising support for catalysts, and it is important to study the performance of the activated coke catalyst on the removal of NOx. In the current research, a series of the activated coke-supported Mn-Cu catalysts are prepared by the incipient wetness impregnation method. The effects of the molar ration of Mn/Cu, the content of Mn-Cu, the calcination temperature, and reaction space velocity on NO conversion are investigated, and it was found that the 8 wt.% Mn0.7Cu0.3/AC had the best catalytic activity when the calcination temperature was 200 °C. The existence of SO2 caused the catalyst to deactivate, but the activity of the poisoning catalyst could be recovered by different regeneration methods. To uncover the underlying mechanism, BET, XPS, XRD, SEM and FTIR characterizations were performed. These results suggested that the specific surface area and total pore volume of the poisoning catalyst are recovered and the sulfite and sulfate on the surface of the poisoning catalysts are removed after water washing regeneration. More importantly, the water washing regeneration returns the value of Mn3+/Mn4+, Cu2+/Cu+, and Oα/Oß, related to the activity, basically back to the level of the fresh catalyst. Thus, the effect of water washing regeneration is better than thermal regeneration. These results could provide some helpful information for the design and development of the SCR catalysts.

Experimental and DFT studies on oxygen release and migration mechanisms of LaAl-type perovskites as catalyst supports in biomass-to-H2 conversion.

Perovskites are potential candidates for catalyst supports in biomass gasification to produce high-purity H2 due to their excellent redox properties. However, the significant mechanism of lattice oxygen release and migration in perovskites has not been clearly understood. In this work, the characteristics of surface oxygen release and subsurface oxygen migration in various LaAl-type perovskites were investigated by experiments and density functional theory calculations. Results show that the oxygen release capacity of La0.7Sr0.3AlO3-δ is considerable and that of Ni/La0.7Sr0.3AlO3-δ decreases slightly compared to the difficult occurrence of oxygen release in LaAlO3. Moreover, the rate-limiting step of oxygen release from pure LaAlO3 is determined to be the formation of O2 complex by two opposite O atoms. Sr doping reduces the charge of the outermost O atom, making oxygen release easy, and the desorption process of O2 becomes the rate-limiting step. After Ni loading, the strength of the surrounding Al-O bond increases, which raises the energy barrier and blocks the release of oxygen to some extent.

Insight into the effect of facet-dependent surface and oxygen vacancies of CeO2 for Hg removal: From theoretical and experimental studies.

The reaction mechanisms of Hg oxidation on CeO2(111) and (110) surface are clarified by a group of designed experiments and density functional theory (DFT) calculations. CeO2 nanorods and nanoparticles with exposure (110) and (111) faces were prepared by hydrothermal methods, and their morphological properties were investigated using XRD, XPS and HRTEM. Combined experimental and DFT results, the nanorods show better activity than nanoparticles. The total oxidation of Hg can be partially prohibited by the high barriers for the incorporated chlorine activation at reduced surfaces, due to the strong electronic repulsion of heavily accumulated charges. The energy barrier profiles suggest Hg oxidation is much more favorable on CeO2(110) surface than that on CeO2(111) surface. In the Hg oxidation via HCl and O2, the role of O2 is not only replenishment of lattice oxygen, but also could generate surface oxygen as active center for HCl active. The complete catalytic cycle can be identified as four parts: (i) HCl activated by lattice oxygen, (ii) Hg oxidation on defect surface, (iii) HCl activated by adsorbed oxygen and (iv) Hg oxidation on stoichiometric surface. The results of this study provide deep insights into the effects of CeO2 nanocatalyst morphology on the Hg oxidation.