Inland water is very susceptible to the input of pollutants. However, little is known about the occurrence of antibiotics in inland lakes. In this study, a total of 83 target antibiotics were quantified in water and sediment samples collected from the Qinghai Lake, the largest inland lake of China located on the northeast of Qinghai-Tibet plateau, and its inflowing rivers. The results showed that 27 and 25 antibiotics were detected in water and sediments, respectively, with the summed concentrations (SUM) of 1.14-17.3 ng/L and 0.72-8.31 ng/g. Compared with the input rivers, significantly higher levels of sulfonamides (SAs), quinolones (QNs), polyethers (PEs), and SUM in water samples were observed in Qinghai Lake water. The average proportions of SAs (50.9-52.7%) and QNs (22.0-28.3%) in Qinghai Lake water nearly doubled compared to those in input rivers. An enrichment factor (EF) was proposed to reveal the enrichment degree of antibiotics in Qinghai Lake compared to its input river water. Sulfaguanidine (SGD), flumequine (FLU), and nalidixic acid (NDA) were enriched in Qinghai Lake up to several ten times based on the calculated EF values, due to their persistence in such a cold saline lake. Risk assessment showed that most antibiotics except anhydrochlortetracycline (ACTC) had insignificant risks to aquatic organisms and antibiotic resistance selection in Qinghai Lake water. This study was the first to reveal the enrichment of antibiotics in Qinghai Lake water, and suggests the urgent need to investigate the possible long-term enrichment and environmental risks of antibiotics in inland lakes.
OBJECTIVE: To investigate the role of epigenetics in statins' diabetogenic effect comparing DNA methylation (DNAm) between statin users and nonusers in an epigenome-wide association study in blood. RESEARCH DESIGN AND METHODS: Five cohort studies' participants (n = 8,270) were classified as statin users when they were on statin therapy at the time of DNAm assessment with Illumina 450K or EPIC array or noncurrent users otherwise. Associations of DNAm with various outcomes like incident type 2 diabetes, plasma glucose, insulin, and insulin resistance (HOMA of insulin resistance [HOMA-IR]) as well as with gene expression were investigated. RESULTS: Discovery (n = 6,820) and replication (n = 1,450) phases associated five DNAm sites with statin use: cg17901584 (1.12 x 10(-25) [DHCR24]), cg10177197 (3.94 x 10(-08) [DHCR24]), cg06500161 (2.67 x 10(-23) [ABCG1]), cg27243685 (6.01 x 10(-09) [ABCG1]), and cg05119988 (7.26 x 10(-12) [SC4MOL]). Two sites were associated with at least one glycemic trait or type 2 diabetes. Higher cg06500161 methylation was associated with higher fasting glucose, insulin, HOMA-IR, and type 2 diabetes (odds ratio 1.34 [95% CI 1.22, 1.47]). Mediation analyses suggested that ABCG1 methylation partially mediates the effect of statins on high insulin and HOMA-IR. Gene expression analyses showed that statin exposure and ABCG1 methylation were associated with ABCG1 downregulation, suggesting epigenetic regulation of ABCG1 expression. Further, outcomes insulin and HOMA-IR were significantly associated with ABCG1 expression. CONCLUSIONS: This study sheds light on potential mechanisms linking statins with type 2 diabetes risk, providing evidence on DNAm partially mediating statins' effects on insulin traits. Further efforts shall disentangle the molecular mechanisms through which statins may induce DNAm changes, potentially leading to ABCG1 epigenetic regulation.
In this study, an apatite reference material (RM), Eppawala-AP, was obtained and calibrated from a mega-crystal of Eppawala carbonatite (collected in northwestern region of Sri Lanka) to standardize chlorine isotope analysis. A homogeneity test and chlorine isotope composition measurement of the RM were performed using secondary ion mass spectrometry (SIMS) and continuous gas flow isotope ratio mass spectrometry (CF-IRMS), respectively. The RM, with a recommended delta Cl-37 value of -0.74 +/- 0.15 parts per thousand, can be utilized as a matrix-matched N standard (similar to 1.55 wt. % Cl) to correct the instrumental mass fractionation (IMF) during in situ analysis, or as a quality control material for both in situ and bulk analysis, to facilitate high quality measurement and inter-laboratory data comparison. This RM is available to the scientific community by contacting the corresponding author. Our homogeneity test indicates an absence of orientation effect during SIMS analysis for the specific apatite grain investigated here, and suggests a repeatability of 0.13 parts per thousand for SIMS apatite chlorine isotope analysis. The matrix effect of minerals with complex chemistry predicts that the chlorine content is a controlling factor of IMF during in situ apatite chlorine isotope analysis; hence, additional RMs with variable concentrations of chlorine are required for routine delta Cl-37 measurement.
Background: The 2019 novel coronavirus (COVID-19) outbreak in Wuhan, China has attracted world-wide attention. As of March 31, 2020, a total of 82,631 cases of COVID-19 in China were confirmed by the National Health Commission (NHC) of China. Methods: Three approaches, namely Poisson likelihood-based method (ML), exponential growth rate-based method (EGR) and stochastic Susceptible-Infected-Removed dynamic model-based method (SIR), were implemented to estimate the basic and controlled reproduction numbers. Results: A total of 198 chains of transmission together with dates of symptoms onset and 139 dates of infections were identified among 14,829 confirmed cases outside Hubei Province as reported as of March 31, 2020. Based on this information, we found that the serial interval had an average of 4.60 days with a standard deviation of 5.55 days, the incubation period had an average of 8.00 days with a standard deviation of 4.75 days and the infectious period had an average of 13.96 days with a standard deviation of 5.20 days. The estimated controlled reproduction numbers produced by all three methods in all analyzed regions of China are significantly smaller compared with the basic reproduction numbers. Conclusions: The controlled reproduction number in China is much lower than one in all regions of China by now. It fell below one within 30 days from the implementations of unprecedent containment measures, which indicates that the strong measures taken by China government was effective to contain the epidemic. Nonetheless, efforts are still needed in order to end the current epidemic as imported cases from overseas pose a high risk of a second outbreak.
The overuse of antibiotics has promoted the propagation and dissemination of antibiotic resistance genes (ARGs) in environment. Due to the dense human population and intensive activities in coastal areas, the health risk of ARGs in coastal environment is becoming a severe problem. To date, there still lacks of a quantitative method to assess properly the gross antibiotic resistance at microbial community level. Here, we collected sediment samples from Hangzhou Bay (HB), Taizhou Bay (TB), and Xiangshan Bay (XB) of the East China Sea for community-level ARGs analysis. Based on the 16S rRNA genes and predictive metagenomics, we predicted the composition of intrinsic ARGs (piARGs) and some related functional groups. Firstly, a total of 40 piARG subtypes, belonging to nine drug classes and five resistance mechanisms, were obtained, among which the piARGs encoding multidrug efflux pumps were the most dominant in the three bays. Secondly, XB had higher relative abundances of piARGs and pathogens than the other two bays, which posed higher potential health risk and implied the heavier impact of long-term maricultural activities in this bay. Thirdly, the co-occurrence network analysis identified that there were more connections between piARGs and some potential pathogenic bacteria. Several piARG subtypes (e.g., tetA, aacA, aacC, and aadK) distributed widely in the microbial communities. And finally, the microbial diversity correlated negatively with the relative abundance of piARGs. Oil, salinity, and arsenic had significant effects on the variations of piARGs and potential pathogenic bacteria. The abundance-weighted average ribosomal RNA operon (rrn) copy number of microbial communities could be regarded as an indicator to evaluate the antibiotic resistance status. In conclusion, this study provides a new insight on how to evaluate antibiotic resistance status and their potential risk in environment based on a quantitative analysis of microbial communities.
A model-by-model analysis for historical simulations was necessary for identifying reasonably performing models in the updated Coupled Model Intercomparison Project (CMIP6) over the Tibetan Plateau. To determine whether the capacity of the CMIP6 models in simulating temperature and precipitation over the Plateau has been enhanced, we compared the outputs of 23 CMIP6 models with an observational dataset (CN05.1) for the period 1961–2014. The results suggest the systematic model biases (cold bias and wet bias) in the Tibetan Plateau still exist in CMIP6. Most models in CMIP6 realistically simulated the surface temperature and spatial distribution of precipitation, with a pattern correlation exceeding 0.75. The bias in the mean surface temperature of the multi-model ensemble (MME) simulation was 1.08 °C lower than the observational data, which had been decreased compared with the cold bias of CMIP5 (1.52 °C). At the seasonal scale, most models exhibited a warm temperature bias in summer and a cold bias in winter. The CMIP6 MME displayed a higher reproducibility of the precipitation amplitude over dry regions compared with CMIP5 and a lower ability over wet regions.
In this paper, a novel mathematical model for the heat extraction process from hot dry rocks (HDRs) by enclosed water recycling in a horizontal well is established, on a basis of which a series of exergy analyses are conducted. The pressure and temperature distributions in the wellbore and the exergy extracted under different working conditions are calculated. Eight factors are specifically studied to evaluate their effects on the accumulated exergy of the produced hot water. It is found that the accumulated exergy first gradually increases but decreases subsequently with the water rising flow rate. The accumulated exergy is noticed to increase obviously with the increase of the length for the horizontal section, temperature of the HDR, thermal conductivity of the HDR, and diameter of the casing. The temperature distributions in the HDR around the wellbore are analyzed at different time. More specifically, the temperature drop of the HDR gradually spreads to far area of the wellbore with the continuous extraction of geothermal energy. The temperature of the rock around the wellbore decreases by increasing the injection rate. A higher HDR thermal conductivity leads to a quick heat transfer from the remote to near wellbore area. The exergy analyses in this study provide strong theoretical supports to utilize the HDR heat extraction.