How Well Does the ERA5 Reanalysis Capture the Extreme Climate Events Over China? Part I: Extreme Precipitation

ERA5 is the fifth-generation atmospheric reanalysis of the European Center for Medium-Range Weather Forecasts, with high spatiotemporal resolution and global coverage. However, the reliability of ERA5 for simulating extreme precipitation events is still unclear over China. In this study, 12 extreme precipitation indices and a comprehensive quantitative distance between indices of simulation and observation were used to evaluate ERA5 precipitation from three fundamental aspects: intensity, frequency, and duration. The geomorphological regionalization method was used to divide the subregions of China. The results showed that the ability of ERA5 to simulate annual total precipitation was better than that of daily precipitation. For the intensity indices, ERA5 performs well for simulating the PRCPTOT (annual total wet days precipitation) over China. ERA5 performs better on RX5day (max 5-days precipitation amount) and R95p (very wet days), especially in eastern China, than on RX1day (max 1-day precipitation amount) and R99p (extremely wet days). For the frequency indices, the ability of the ERA5 simulation increased as the amount of precipitation increased, except for northwestern China. However, the ability of ERA5 to simulate R50 mm (number of extreme heavy precipitation days) decreased. For the duration indices, ERA5 was better at simulating drought events than wet events in eastern China. Our results highlight the need for ERA5 to enhance the simulation of trend changes in extreme precipitation events

How Well Does the ERA5 Reanalysis Capture the Extreme Climate Events Over China? Part II: Extreme Temperature

The fifth-generation atmospheric reanalysis of the European Center for Medium-Range Weather Forecasts (ERA5) is the latest reanalysis product. However, the reliability of ERA5 to capture extreme temperatures is still unclear over China. Hence, based on conventional meteorological station data, a new criterion (DISO) was used to validate the ERA5 capturing extreme temperature indices derived from the Expert Team on Climate Change Detection and Indices (ETCCDI) across the six subregions of China on different timescales. The conclusions are as follows: the original daily temperatures (mean temperature, maximum temperature, and minimum temperature) can be well reproduced by ERA5 reanalysis over China. ERA5 tends to exhibit more misdetection for the duration of extreme temperature events than extreme temperature intensity and frequency. In addition, ERA5 performed best in the summer and worst in the winter, respectively. The trend of absolute indices (e.g., TXx and TNx), percentile-based indices (e.g., TX90p, TX10p, TN90p, and TN10p), and duration indices (e.g., WSDI, CSDI, and GSL) can be captured by ERA5, but ERA5 failed to capture the tendency of the diurnal temperature range (DTR) over China. Spatially, ERA5 performs well in southeastern China. However, it remains challenging to accurately recreate the extreme temperature events in the Tibetan Plateau. The elevation difference between the station and ERA5 grid point contributes to the main bias of reanalysis temperatures. The accuracy of ERA5 decreases with the increase in elevation discrepancy

Protective Effect and Mechanism of Chinese Yam Total Protein on High D-Glucose Induced Oxidative Stress in Human Umbilical Vein Endothelial Cells

To explored the protective effect and mechanism of Chinese yam total protein in human umbilical vein endothelial cells (HUVECs) with high-concentration D-glucose (HG)-induced oxidative stress injury. The HUVECs injury model was established by 50 mmol/L HG. HUVECs were randomly divided into control, model, low-dose Chinese yam total protein (0.5 mg/mL), and high-dose Chinese yam total protein (1 mg/mL) groups. The effects of Chinese yam total protein on the viability, morphology, and angiogenetic ability of HUVECs treated with HG were evaluated. The reactive oxygen species (ROS) level, superoxide dismutase (SOD) and catalase (CAT) activities in cells were determined. The nitric oxide (NO), 8-hydroxy deoxyguanosine (8-OHdG), malondialdehyde (MDA), interleukin-1β (IL-1β), and interleukin-6 (IL-6) levels in culture medium supernatant were measured. Protein expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), thioredoxin-interacting protein (Txnip), NOD-like receptor protein 3 (NLRP3), cleaved Caspase-1, and IL-1β were determined. The results showed that Chinese yam total protein could significantly increased the cell viability of HUVECs treated with HG (P<0.01), improved cell apoptotic morphology, and significantly increased the activities of SOD and CAT (P<0.05, P<0.01) and ratio of apoptosis-related proteins (Bcl-2/Bax), angiogenetic ability and nitric oxide (NO) secretion. Moreover, Chinese yam total protein significantly decreased the levels of ROS, MDA, 8-OHdG, IL-1β, and IL-6 (P<0.05, P<0.01) and the expression levels of inflammation-related proteins (Txnip, NLRP3, cleaved Caspase-1, and IL-1β) (P<0.05, P<0.01). Changes in these indicators showed a significant concentration-dependent manner. The results indicate that Chinese yam total protein may protect against HG-induced oxidative stress by inhibiting the Txnip/NLRP3 signaling pathway, restoring the oxidative balance, and reducing the inflammatory response of HUVECs

Andrographolide alleviates paraquat-induced acute lung injury by activating the Nrf2/HO-1 pathway

Objective(s): Paraquat (PQ), a highly effective and rapidly non-selective herbicide, mainly targets the lungs and causes acute lung injury (ALI). So far, the scarcity of effective drug candidates against PQ-induced ALI remains a big challenge. Andrographolide (Andro), with its anti-inflammatory and antioxidant activities, has been demonstrated to alleviate ALI. Nevertheless, whether Andro could alleviate the PQ-mediated ALI remains unknown. Therefore, this study will explore the effects as well as the possible mechanism of Andro against ALI caused by PQ. Materials and Methods: C57BL/6J mice were injected with 20 mg/kg PQ intraperitoneally to establish an ALI model. PQ-treated MLE-12 cells were applied to a vitro model. Nuclear factor erythroid like-2 (Nrf2) was knocked out to explore the specific effects of the Nrf2/ Heme oxygenase-1 (OH-1) pathway in the protection of Andro against ALI caused by PQ.Results: Andro significantly reduced lung damage and the ratio of Wet/Dry (W/D) weight, decreased MDA, IL-6, IL-1β, and TNF-ɑ levels, reversed the decrease of CAT and SOD levels, and inhibited apoptosis caused by PQ. Andro obviously increased the ratio of Bcl-2/Bax while reducing caspase-3 and cleaved caspase-3 levels. Furthermore, Andro dramatically elevated the antioxidant proteins Nrf2, NQO-1, and HO-1 levels compared with the PQ group. This experiment demonstrated that Andro reduced ROS and inhibited apoptosis, induced by PQ in MLE-12 cells, by inducing Nrf2/HO-1 pathway activation.Conclusion: Andro effectively ameliorates oxidant stress and apoptosis in ALI caused by PQ, possibly through inducing Nrf2/HO-1 pathway activation

Rough surface Au@Ag core–shell nanoparticles to fabricating high sensitivity SERS immunochromatographic sensors

Immunochromatographic sensors (ICSs) are inexpensive, simple, portable, and robust, thus making ICSs commonplace in clinical diagnoses, food testing, and environmental monitoring. However, commonly used gold nanoparticles (AuNPs) ICSs have low sensitivity. Therefore, we developed highly sensitive surface enhanced Raman scattering (SERS) ICSs. To enhance the sensitivity of SERS ICSs, rough surface core–shell Au@Ag nanoparticles (RSAu@AgNPs) were prepared by coating silver on the surface of gold nanoflowers (AuNFs). Then these nanoparticles were used as SERS substrate in the SERS ICSs, after which the SERS ICSs were implemented to detect haemoglobin and heavy metal cadmium ion (Cd(2+)). The limit of detection (LOD) of the SERS ICSs for detecting haemoglobin was 8 ng/mL, and the linear range of the SERS ICSs was from 31.3 to 2000 ng/mL. The LOD of the SERS ICSs for detecting Cd(2+) was 0.05 ng/mL and the linear analysis range was from 0.05 to 25 ng/mL. The cross reactivity of the SERS ICSs was studied and results showed that the SERS ICSs exhibited highly specific for detection of haemoglobin and Cd(2+), respectively. The SERS ICSs were then used to detect haemoglobin (spiked in serum and in stool) and Cd(2+) (spiked in tap water, river water, and soil leaching water), and the results showed high recovery. These characteristics indicated that SERS ICSs were ideal tools for clinical diagnosis and environmental pollution monitoring. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12951-015-0142-0) contains supplementary material, which is available to authorized users

Ginsenosides on stem cells fate specification—a novel perspective

Recent studies have demonstrated that stem cells have attracted much attention due to their special abilities of proliferation, differentiation and self-renewal, and are of great significance in regenerative medicine and anti-aging research. Hence, finding natural medicines that intervene the fate specification of stem cells has become a priority. Ginsenosides, the key components of natural botanical ginseng, have been extensively studied for versatile effects, such as regulating stem cells function and resisting aging. This review aims to summarize recent progression regarding the impact of ginsenosides on the behavior of adult stem cells, particularly from the perspective of proliferation, differentiation and self-renewal

How should off-campus training react to the “Double Reduction” policy?

After the introduction of the “Double Reduction” policy, off-campus training institutions are under strict supervision. According to the policy details, discipline training institutions confront various problems, such as the closure of listing channels, the substantial reduction of financial income, and the unemployment of the training personnel. By analyzing the current situation of related institutions and their personnel, this study provides meaningful references for discipline training institutions in transformation direction and talent management. Also, it puts forward suggestions for training personnel to change their jobs