ABSTRACT
Global warming is profoundly impacting snowmelt runoff processes in seasonal freeze-thaw zones, thereby altering the risk of rain-on-snow (ROS) floods. These changes not only affect the frequency of floods but also alter the allocation of water resources, which has implications for agriculture and other key economic sectors. While these risks present a significant threat to our lives and economies, the risk of ROS floods triggered by climate change has not received the attention it deserves. Therefore, we chose Changbai Mountain, a water tower in a high-latitude cold zone, as a typical study area. The semi-distributed hydrological model SWAT is coupled with CMIP6 meteorological data, and four shared socioeconomic pathways (SSP126, SSP245, SSP370, and SSP585) are selected after bias correction, thus quantifying the impacts of climate change on hydrological processes in the Changbai Mountain region as well as future evolution of the ROS flood risk. The results indicate that: (1) Under future climate change scenarios, snowmelt in most areas of the Changbai Mountains decreases. The annual average snowmelt under SSP126, SSP245, SSP370, and SSP585 is projected to be 148.65 mm, 135.63 mm, 123.44 mm, and 116.5 mm, respectively. The onset of snowmelt is projected to advance in the future. Specifically, in the Songhua River (SR) and Yalu River (YR) regions, the start of snowmelt is expected to advance by 1-11 days. Spatially, significant reductions in snowmelt were observed in both the central part of the watershed and the lower reaches of the river under SSP585 scenario. (2) In 2021-2060, the frequency of ROS floods decreases sequentially for different scenarios, with SSP 126 > SSP 245 > SSP 370 > SSP 585. The frequency increments of ROS floods in the source area for the four scenarios were 0.12 days/year, 0.1 d/yr, 0.13 days/year, and 0.15 days/year, respectively. The frequency of high-elevation ROS events increases in the YR in the low emission scenario. Conversely, in high emission scenarios, YR high-elevation ROS events will only increase in 2061-2100. This phenomenon is more pronounced in the Tumen River (TR), where floods become more frequent with increasing elevation.
Subject(s)
Altitude , Climate Change , Floods , Rain , Snow , HydrologyABSTRACT
What is already known about this topic?: The hospital-acquired infections caused by New Delhi metallo-beta-lactamase (NDM)-producing strains are typically attributed to a single clonal lineage. What is added by this report?: In this study, we encountered a unique case of community-acquired NDM-5 Escherichia coli urinary tract infection (UTI) following coronavirus disease 2019 (COVID-19). The UTI persisted for a duration of at least 45 days. Genomic analyses revealed the presence of two NDM-5 strains, both sharing an identical chromosomal background but distinct, homologous, and recombined plasmids. This case suggests that a diverse range of resistance genes may be present within the human body, with drug-resistant strains undergoing continuous evolution during infection. The intestinal tract may have been its drug-resistant gene pool. What are the implications for public health practice?: The observations presented in this case indicate that the endogenous acquisition of drug-resistant genes may also be an issue in managing multidrug-resistant organisms (MDRO). It is possible for continuous recombination to occur within carbapenem-resistant Enterobacteriaceae (CRE) during infection. In contrast to exogenously-acquired resistance, greater attention should be placed on the endogenous factors that contribute to the development of CRE within healthcare settings.
ABSTRACT
To screen the anti-inflammatory active fraction of unripe Forsythiae Fructus, and elucidate the action mechanism, water decoction, ethyl acetate portion, n-butanol portion and residue water extracts of unripe Forsythiae Fructus were administered into rats for continuously 15 days. The acute lung injury inflammatory model was established to observe the section structure of lung tissues. Levels of IL-6, TNF-α, IL-1ß and IL-10 in bronchoalveolar lavage fluid were determined by ELISA kits, and changes in endogenous metabolites in serum were analyzed based on 1H-NMR metabolomics. The results showed that ethyl acetate portion of unripe Forsythiae Fructus had a better anti-inflammatory activity against acute lung injury, and could suppress the release of inflammatory factors of IL-6, TNF-α, IL-1ß, significantly reduce contents of creatine, ß-OH-butyrate, succinate, lysine, valine, isoleucine and glutamine, and elevate the content of GPC in serum. Ethyl acetate portion was proved to be the main fraction of anti-inflammatory activity from the perspective of endogenous metabolites in serum, and played an anti-inflammatory role by regulating creatine metabolism, choline metabolism, branched-chain amino acid metabolism and TCA cycles. This study could lay a foundation for studying pharmacodynamic material basis of unripe Forsythiae Fructus.