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Background: Coronavirus disease 2019 (COVID-19) is pandemic. It is critical to identify COVID-19 patients who are most likely to develop a severe disease. This study was designed to determine the clinical and epidemiological features of COVID-19 patients associated with the development of pneumonia and factors associated with disease progression., Methods: Seventy consecutive patients with etiologically confirmed COVID-19 admitted to PLA General Hospital in Beijing, China from December 27, 2019 to March 12, 2020 were enrolled in this study and followed-up to March 16, 2020. Differences in clinical and laboratory findings between COVID-19 patients with pneumonia and those without were determined by the χ 2 test or the Fisher exact test (categorical variables) and independent group t test or Mann-Whitney U test (continuous variables). The Cox proportional hazard model and Generalized Estimating Equations were applied to evaluate factors that predicted the progression of COVID-19., Results: The mean incubation was 8.67 (95% confidence interval, 6.78-10.56) days. Mean duration from the first test severe acute respiratory syndrome coronavirus 2-positive to conversion was 11.38 (9.86-12.90) days. Compared to pneumonia-free patients, pneumonia patients were 16.5 years older and had higher frequencies of having hypertension, fever, and cough and higher circulating levels of neutrophil proportion, interleukin-6, low count (< 190/µl) of CD8 + T cells, and neutrophil/lymphocyte ratio. Thirteen patients deteriorated during hospitalization. Cox regression analysis indicated that older age and higher serum levels of interleukin-6, C-reactive protein, procalcitonin, and lactate at admission significantly predicted the progression of COVID-19. During hospitalization, circulating counts of T lymphocytes, CD4 + T cells, and CD8 + T cells were lower, whereas neutrophil proportion, neutrophil/lymphocyte ratio, and the circulating levels of interleukin-6, C-reactive protein, and procalcitonin were higher, in pneumonia patients than in pneumonia-free patients. CD8 + lymphocyte count in pneumonia patients did not recover when discharged., Conclusions: Older age and higher levels of C-reactive protein, procalcitionin, interleukin-6, and lactate might predict COVID-19 progression. T lymphocyte, especially CD8 + cell-mediated immunity is critical in recovery of COVID-19. This study may help in predicting disease progression and designing immunotherapy for COVID-19.

To investigate the hydrochemical variation of karstic groundwaters in a vertically zoned climate region affected by human activity, Shuifang Spring and Bitan Spring in the Jinfo Mountain area of Chongqing were selected as a study site. Based on the differences between the natural state and intensity of human activity of these two springs, their hydrogeochemical characteristics and the controlling factors on karstic groundwaters were analyzed by means of independent sample t tests, the Gibbs graphic method, principle component analysis (PCA), and geochemical susceptivity analysis. The results show that differences in karst development in the vertical climatic zone leads to higher total ion concentrations in Bitan Spring than in Shuifang Spring. The hydrochemical types of Shuifang Spring and Bitan Spring are HCO 3 -Ca and HCO 3 -Ca·Mg, respectively, which reflect the lithology of their different elevations. Carbonate rock dissolution is the main source of Ca 2+ , Mg 2+ , and HCO 3 - in karstic groundwaters. Hotel sewage discharge supplies SO 4 2- , NO 3 - , PO 4 3- , K + , and Na + in Shuifang Spring, which peaked in winter and summer, while hydrochemical parameters of Bitan Spring changed smoothly throughout the year. The water quality of Bitan Spring is better than Shuifang Spring (Shuifang Spring water is classified as Class Ⅳ). PCA shows that the water-rock interaction was the first controlling factor. Hotel sewage discharge and ions from precipitation had important effects on Shuifang Spring and Bitan Spring, respectively. In addition, the effects of soil erosion and leaching caused by precipitation also impact on the water quality of two springs to some extent. The geochemical susceptibility of Shuifang Spring was greater than that of Bitan Spring; therefore, corresponding measures should be formulated according to the characteristics of these differently elevated karst systems when exploiting groundwater resources. This is especially the case for the treatment of hotel sewage.

With urbanization, groundwater in China has been widely polluted. Karst groundwater is important in southwest China, and would be difficult to recover once contaminated. NO3(-), PO4(3), NH4(+), total coliform, total E. coli and fecal coliform were chosen as indexes in the study of groundwater of Laolongdong Underground River System in Nanshan Mountain, Chongqing. After a few years of survey, the results showed that NO3(-), NH4(+) and PO4(3-) concentrations in the water were all above the nature value, especially NH4(+) and PO4(3-). The NO3(-) concentration of Guihuawan spring ranged from 19.78-68.55 mg x L(-1), in some months, above the recommended water quality guideline (50 mg x L(-1)) according to Standards for Drinking Water Quality set by World Health Organization. NH4(+) and PO4(3-) concentrations in Laolongdong underground river varied from 2.71-12.92 mg x L(-1) and 0.16-11.22 mg x L(-1). The NO3(-) concentration in Laolongdong underground river was lower than in karst spring; however, the concentrations of NH4(+) and PO4(3-) were higher than in the spring. It seemed that the NO3(-) concentration tended to decrease from 2008 to 2013 in the underground river caused by urbanization, reduction of farmland and reducing environment. However, waste water with a high PO4(3-) concentration led to an increasing trend in the PO4(3-) concentration in underground river. Microbial contamination was extremely serious, and even far exceeded class V of water quality standards of China. For example, the concentration of fecal coliform in the groundwater ranged from 3.4 x 10(4)-3.68 x 10(4) CFU x mL(-1). Because of the special hydrogeological structure, karst depressions, skylights and sinkholes can lead pollutants easily to the underground water. Agriculture activity, sewage from towns, enterprises and residential areas were the major sources of nitrogen, phosphorus and microbial contamination.

Quoted geochemical susceptivity index and isosensitive line on geochemical susceptivity, analyzed the data of underground rivers of Xueyu Cave in Chongqing from September 2010 to August 2011, we found that the chemical composition of the underground river was controlled by the bedrock, due to the composition of high concentration of Ca2+ and low concentration of Mg2+. Owing to the effects of the monsoon, water chemistry was different between drought season and rainy season: the value of [Mg2+]/[Ca2+] was 0.018-0.051 in the rainy season, but in dry season the value was 0.038-0.064. The value of [HCO3(-)]/[SO4(2-)] was 4.86-36.62 in the rainy season, and 6.23-46.67 in the dry season. The seasonal change of Karstification made Ca2+ and HCO3(-) become the most sensitive ion. As a result of the special hydrogeological structure in Karat area, rain, surface water and groundwater transformed rapidly, which caused the underground river was sensitive to agricultural activities, especially for Cl- and NO3(-), and their sensitive indices were 0.286 and 0.022 respectively. The influence of tourism activities on the underground river was less than the management. The management work of ecological system should be strengthen in the recharge area, thus the largest economic and environmental benefits in the Karst area could be achieved.

Storm periods are the crucial stage to reveal input and outlet of material and energy in groundwater system. Jiangjia spring, the outlet of Qingmuguan groundwater system, was taken as an example. Distribution of suspended particle in the Jiangjia spring was continuously monitored. Supported by hydrochemical data, characteristics and sources of the suspended particle in the karst groundwater system were investigated. Results show that the number of suspended particle in size of 0-11 microm abruptly increased in the channel of Jiangjia spring at the beginning of rainfall occurred. It indicates the suspended particle was derived from allochthonous material. While the groundwater was recharged by karst fissure, the number of suspended particle in size of 0-11 microm sharply raised, which shows that the suspended particle was autochthonous. Finally, the number of suspended particle in size of 0-4 microm elevated due to the entire groundwater watershed recharged by rainfall and dilution effect occurring again, suggesting the suspended particle was derived from allochthonous material. Owing to the intrinsic hydrogeological settings and rainfall intensity, the threshold of size for the suspended particle was 4 pm in Qingmuguan groundwater system. It probably was a high practical significance to indicate the groundwater was whether polluted by microbe or not.

In order to investigate the nitrate storage and transport in the karst aquifer system, the hydrochemical dynamics of Qingmuguan underground river system was monitored online by achieving high-resolution data during storm events and monthly data in normal weather. The principal component analysis was employed to analyze the karst water geochemistry. Results showed that nitrate in Jiangjia spring did not share the same source with soluble iron, manganese and aluminum, and exhibited different geochemical behaviors. Nitrate was derived from land surface and infiltrated together with soil water, which was mainly stored in fissure, pore and solution crack of karst unsaturated zone, whereas soluble iron, manganese and aluminum were derived from soil erosion and directly recharged the underground river through sinkholes and shafts. Nitrate transport in the karst aquifer system could be ideally divided into three phases, including input storage, fast output and re-inputting storage. Under similar external conditions, the karstification intensity of vadose zone was the key factor to determine the dynamics of nitrate concentrations in the groundwater during storm events. Nitrate stored in the karst vadose zone was easily released, which would impair the aquatic ecosystem and pose seriously threats to the local health. Thus, to strengthen the management of ecological system, changing the land-use patterns and scientifically applying fertilizer could effectively make a contribution to controlling mass nutrient input from the surface.

Objective: To assess whether the TaqIB polymorphism of cholesteryl ester transfer protein (CETP) is associated with coronary artery disease (CAD) in Chinese population, we performed a meta-analysis in this paper., Methods: We searched PubMed, Embase, the Science Citation Index (SCI), the China Biological Medicine database (CBM), the China National Knowledge Infrastructure (CNKI), and the Wanfang database for relevant articles. Data were extracted, and pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated., Results: The literature search yielded 448 studies, in which 10 case-control studies including 1694 cases and 1456 controls matched the selection criteria. The combined B1 and B2 allele frequencies were 0.587 and 0.413, respectively. The pooled OR was 1.10 (95% CI, 0.89-1.34) for comparing the B1B1 or B1B2 carriers with B2B2 carriers, and was 1.27 (95% CI, 1.09-1.49) in the B1B1 carriers versus B2B2 or B1B2 carriers., Conclusions: In the present study, the TaqIB polymorphism of CETP was found to be associated with CAD in the Chinese population.

In order to thoroughly reveal the karst groundwater system in response to the external environment, multi-index high-resolution auto-monitoring instruments were used to research the hydrogeochemistry variations of Qingmuguan subterranean stream. The monitoring indicators were pH value, electrical conductivity (EC), water level, rainfall and NO3-. In the observed 6 times rainfall events, the pH value was mainly controlled by acid rain and EC was impacted by the rain chemistry, physical dilution effect of rainfall and agricultural wastewater. NO3- derived from agricultural activities was less impacted by rain chemistry; and its variations were mainly affected by physical dilution effect of rainfall and agricultural wastewater. Under the influences of the R1 rainfall, the rapid changes of EC and NO3- were contrary in generally, but pH value decreased due to the acid rain. In the R2, R3, R4 and R6 rain events, the water level was positively response to the rainfall and the pH value decreased due to the acid rain; however both of the EC and NO3- decreased due to the dilution effect. With the afflux of agricultural wastewater, both of the EC and NO3- were rapidly changed in synchronization within the shortest of 5 h of and the longest of only 27 h and the pH value showed accelerated decline. During the R5 torrential rain events, water level abruptly increased and all of the pH value, EC and NO3- sharply decreased as a result of dilution effect. The groundwater quality was changed because the afflux of agricultural wastewaters in the entire rainfall periods. According to the National Groundwater Quality Standard, P. R. China (GB/T 14848-9), the groundwater quality of the QSS showed the following order in the entire rainfall events: Grade III --> Grade IV --> Grade V --> Grade 1V --> Grade V --> Grade LV --> Grade V --> Grade IV --> Grade III. As a important drinking water source around local inhabitants, the groundwater quality of Qingmuguan subterranean stream was deteriorated to Grade V in rain-fertilize periods. However, the sampling methods in field did show a simple variation curve. Consequently,the results from the research illustrate the need to redesign hydrochemical sampling methods for karat hydrology system, especially under the impact of human activities.

Groundwater in Qingmuguan underground river was monitored using hydro-chemical and 15N isotope techniques to investigate temporal and spatial variations of nitrate-nitrogen and its possible sources from October, 2007 to October, 2008. The results show that nitrate concentrations are 3.20 mg/L of the inlet (D1) and 20.35 mg/L of the outlet (S2) of the underground river. Affected by the fertilizers in agricultural field and the rainfall flush and dilution,nitrate concentrations of groundwater are higher but less stable from April to July, 2008 than that from October, 2007 to March, 2008. They are elevated during August and September, 2008 due to the residual fertilizers and decreased rainfall events. According to the NO3- -delta 15N values of -0.857% per hundred +/- 2.01% per hundred (n=9), the sources of nitrate-nitrogen of D1 are dominated by residual fertilizers from the paddy fields from October, 2007 to March, 2008 and from July to October, 2008, while the NO3- -delta 15N values of 2.50% per hundred +/- 0.29% per hundred (n=3) demonstrate that the mixture of soil organic nitrogen and fertilizers are the sources from April to middle and late June, 2008. And the NO3- -delta 15N values of -3.74% per hundred in late May and 0.52% per hundred in early June indicate that the nitrate-nitrogen comes from fertilizers applied in the paddy fields in 2008. The nitrate-nitrogen of S2 is partly from fertilizers in the upper basin, and also from fertilizers and soil organic nitrogen carried by lateral fissure and soil permeation water of forest and farm land in the middle and lower basin. The NO3- -delta 15N values of 4.77% per hundred (n=9) show nitrate-nitrogen of S2 mainly originates from fertilizers from October, 2007 to March, 2008 and from July to October, 2008, while NO3- -delta 15N values of 3.16% per hundred +/- 0.39% per hundred (n=5) explain that the nitrate-nitrogen derives from the mixture of soil organic nitrogen and fertilizers from April to June, 2008.

Hydrologic process, turbidity, suspended particles matters (SPM), major cations and TOC concentrations during two storm events in late April 2008 were monitored at Jiangjia Spring which is the outlet of Qingmu Guan underground river system. Scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS) analyses of SPM were also performed in order to investigate the transport characteristics of substances, such as SPM, turbidity and major cations in the underground river of typical karst watershed. The results show that at a single and well-developed karst conduit of Jiangjia Spring, discharge, turbidity, and concentrations of SPM, major cations and TOC respond promptly to the rainfall. The carbonate-derived cations including Ca2+, Mg2+ and Sr2+ are subject to dilution effect during the rising limb of discharge. The elevation in turbidity and SPM concentration is a result of the gradual increase of allochthonous substances (soil) flux input from the surface. Al3+, Fe, Mn, Ba2+ and TOC are concomitant substances of SPM. And their concentrations are ascending with turbid rise. The flux of SPM in diameter > 0.45 microm in the underground river is about 9.7 tons during the events. The bad water quality suggests us that the spring water is unfit to drink without purification during the period of rising and recession time of discharge at Jiangjia Spring. Thus, soil erosion and nutrient losing not only strongly destroy the fragile karst ecological environment, but also lead to non-point source pollution, and seriously threaten the drinking water safety of locals.