ABSTRACT
High time resolution and accuracy are of critical importance in the studies of timing analysis and time delay localization of gamma-ray bursts (GRBs), soft gamma-ray repeaters (SGRs) and ...pulsars. The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) consisting of two micro-satellites, GECAM-A and GECAM-B, launched on 2020 December 10, is aimed at monitoring and locating X-ray and GRBs all over the sky. To achieve its scientific goals, GECAM is designed to have the highest time resolution (0.1 $\mu {\rm s}$) among all GRB detectors ever flown. Here, we make a comprehensive time calibration campaign including both on-ground and on-orbit tests to derive not only the relative time accuracy of GECAM satellites and detectors, but also the absolute time accuracy of GECAM-B. Using the on-ground calibration with a $\rm ^{22}Na$ radioactive source, we find that the relative time accuracy between GECAM-A and GECAM-B is about 0.15 $\mu {\rm s}$ (1σ). To measure the relative time accuracy between all detectors of a single GECAM satellite, cosmic-ray events detected on orbit are utilized since they could produce many secondary particles simultaneously record by multiple detectors. We find that the relative time accuracy among all detectors onboard GECAM-B is about 0.12 $\mu {\rm s}$ (1σ). Finally, we use the novel Li-CCF method to perform the absolute time calibration with Crab pulsar and SGR J1935+2154, both of which were jointly observed by GECAM-B and Fermi/GBM, and obtain that the time difference between GECAM-B and Fermi/GBM is 3.06 ± 6.04 $\mu {\rm s}$ (1σ).
Carboxylesterases (CarEs) play an important role in detoxifying insecticides in insects. Over‐expression and structural modification of CarEs have been implicated in the development of ...organophosphate (OP) insecticide resistance in insects. A previous study identified four nonsynonymous mutations (resulting in four amino acid residue substitutions) in the open reading frame of the carboxylesterase gene of resistant cotton aphids compared to the omethoate susceptible strain, which has possibly influenced the development of resistance to omethoate (a systemic OP insecticide). The current study further characterized the function of these mutations, both alone and in combination, in the hydrolysis of OP insecticides. The metabolism results suggest that the combination of four mutations, mainly existing in the laboratory‐selected OP‐resistant cotton aphid population, increased the OP hydrolase activity (approximately twofold) at the cost of detectable carboxylesterase activity. The functional studies of single or multiple mutations suggest the positive effect of H104R, A128V and T333P on the acquisition of OP hydrolase activity, especially the combination of H104R with A128V or T333P. K484R substitution decreased both the OP hydrolase activity and the CarE activity, indicating that this mutation primarily drives the negative effect on the acquisition of OP hydrolase activity amongst these four mutations in the resistant strain. The modelling and docking results are basically consistent with the metabolic results, which strongly suggest that the structural gene modification is the molecular basis for the OP resistance in this laboratory‐selected cotton aphid strain.
Aim To explore the role of diffusion-weighted imaging (DWI) in the discrimination of brain abscess from other ring-enhancing brain lesions through meta-analysis. Materials and methods The PUMBED, ...OVID, and China National Knowledge Infrastructure (CNKI) databases, from January 1995 to March 2013, were searched for studies evaluating the diagnostic performance of DWI in the discrimination of brain abscess lesions. Using the data collected, pooled sensitivities and specificities across studies were determined, positive and negative likelihood ratios (LR) were calculated, and summary receiver operating characteristic (SROC) curves were constructed. Results A total of 11 studies fulfilled all of the inclusion criteria and were considered for the analysis. The pooled sensitivity values and pooled specificity values including 95% confidence intervals (CI) were 0.95 (0.87–0.98) and 0.94 (0.88–0.97). The pooled positive LR (95% CI) was 4.13(2.55–6.7); the pooled negative LR (95% CI) was 0.01 (0–1.7); and the area under the curve of the symmetric SROC was 0.98. Conclusions DWI has high sensitivity and specificity for the differentiation of brain abscess from other intracranial cystic mass lesions.
Highlights ► Valproate is a histone deacetylase inhibitor. ► Valproate attenuated ONC-induced RGCs loss. ► Valproate reduced ONC-induced apopotisis in RGCs. ► Valproate promoted the transcriptional ...activity of BDNF promoter in the retina. ► Valproate induced the BDNF-TrkB signaling in the retina following ONC.
Soil classification systems are not consistent between countries or organizations thereby hindering the communication and organizational functions they are intended to promote. World Reference Base ...for soil resources (WRB) was endorsed and adopted by the International Union of Soil Sciences (IUSS) as the standard for soil correlation and international communication. As a widely used classification system in China, Genetic Soil Classification of China (GSCC) differs from WRB in its underlying understanding about the genetic process. The differences limit communication between Chinese and international soil scientists because there is no standard cross-reference between GSCC and WRB. This paper describes a cross-reference of GSCC to WRB at different scales. The basic soil data set used in the study includes 7292 soil profile data (representative of soil series) collected throughout China. First, a brief history of soil classification in China is provided to familiarize readers with GSCC and its origins. Second, cross-reference at the pedon scale is addressed based on data compiled from 51 monoliths acquired in China by the International Soil Reference and Information Centre (ISRIC) in the 1980s and 1990s. Each of GSCC's 7292 soil series is classified into their equivalent reference soil groups according to the WRB soil reference key. Pedon scale cross referencing is discussed using the database from the Second National Soil Survey of China. Third, the concept and calculation of referencibility is introduced and the process for cross-referencing soil classification systems at national scale is addressed. GIS based analysis generates 60 reference results between GSCC soil great groups and WRB reference group. Results demonstrate that there is great variability in the maximum referencibility between soil great groups of GSCC and WRB soil groups, which ranged from 29.4% to 100%. In terms of the maximum referencibility, it can be divided into three categories: high (80%–100%), intermediate (50%–80%), and low (<
50%). Among the 60 soil great groups of GSCC, 12 could be labeled as high maximum referencibility, 27 categorized as medium maximum referencibility and the remaining 21 are associated with low maximum referencibility. Finally, the main cause of low maximum referencibility is explored and the potential solution to improve cross reference accuracy was proposed.
Soil classification systems are not consistent among countries or organizations thereby hindering the communication and organizational functions they are intended to promote. The development of ...translations between systems will be critical for overcoming the gap in understanding that has resulted from the lack of a single internationally accepted classification system. This paper describes the application of a process that resulted in the translation of the Genetic Soil Classification of China (GSCC) to Soil Taxonomy (ST). A brief history of soil classification in China is also provided to familiarize readers with GSCC and its origins. Genetic Soil Classification of China is the attribute base for the recently assembled digital form of the 1:1 000 000 soil map of The People's Republic of China. The translation between GSCC and ST was based on profile, chemical, and physical descriptions of 2540 soil series. First, the 2540 soil series were classified to their equivalent soil order, suborder, great group, and subgroup according to ST and GSCC subgroup descriptors. Order names for both classification systems were then linked to corresponding map units in the 1:1 000 000 digital soil map of China using a geographic information system (GIS). Differences in classification criteria and in the number of orders of the two systems (there are more GSCC orders than ST orders) meant that each GSCC order could possibly be assigned to more than one ST order. To resolve the differences, the percent correspondence in area between orders was determined and used as the criterion for assigning GSCC orders to ST orders. Some percentages of correspondence were low so additional processing was used to improve the assignment process. The GSCC suborders were then matched with ST orders. When the area for each order was summarized, the percentage of correspondence increased except for two subgroups in the Ferrasols order.
Summary
The relation between hepatitis B virus (HBV) infection and fatty liver has been addressed by several observational studies, but their results remain controversial. To date, no study has ...precisely investigated the association of current and past HBV infection with the risk of nonalcoholic fatty liver disease (NAFLD) in the Chinese population. Therefore, we conducted a hospital‐based case‐control study in southwestern China to clarify this issue. A total of 631 newly ultrasound‐diagnosed NAFLD cases and 2357 controls were selected from 123 243 consecutive patients admitted to a tertiary‐care hospital between January 2015 and December 2016. Multivariate logistic regression was employed to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). A propensity score was developed for adjustment and matching. Subgroup analysis was conducted to identify potential effect modifiers. Current and past HBV infection had an overall prevalence of 9.7% and 55.2%, respectively. In the fully adjusted model, current HBV infection was associated with a decreased risk of NAFLD (OR 0.64; 95% CI 0.42‐0.95). A similar inverse association was observed in both propensity‐score‐adjusted (OR 0.58; 95% CI 0.40‐0.86) and propensity‐score‐matched analyses (OR 0.61; 95% CI 0.40‐0.92).The inverse association was stronger in patients with hypertension than in those without (Pinteraction = .018).No significant association between past HBV infection and NAFLD risk was found. In conclusion, current but not past HBV infection is associated with a decreased risk of NAFLD in the Chinese population. The corresponding biological mechanisms remain to be elucidated.
A novel hydrous-manganese-oxide-coated alumina (HMOCA) material was prepared through a redox process. The adsorbent was characterized by SEM, BET surface area measurement, XRD, pH
PZC measurement, ...FTIR spectroscopy, and XPS. The manganese oxides were amorphous and manganese existed mainly in the +IV oxidation state. Batch and column experiments were carried out to investigate the adsorption potential of the adsorbent. Fluoride adsorption onto HMOCA followed the pseudo-second-order equation well with a correlation coefficient greater than 0.99. Both external and intraparticle diffusion contributed to the rate of transfer and removal. The adsorption of fluoride was thought to take place mainly by ion-exchange. Optimum removal of fluoride occurred in a pH range of 4.0–6.0. The maximum adsorption capacity calculated from the Langmuir model was 7.09
mg/g. The presence of HCO
3
−, SO
4
2− and PO
4
3− had negative effects on the adsorption of fluoride. The adsorbed fluoride can be released by alkali solution. Column studies were performed and 669 bed volumes were treated with the effluent fluoride under 1.0
mg/L at an influent F
− concentration of 5.0
mg/L and flow rate of 2.39
m
3/(m
2
h) (empty bed contact time
=
7.5
min).
The present study was carried out to investigate the changes in amino acid (AA) contents of crop milk and plasma and mRNA abundance of AA transporters and AA synthesis-related enzymes in the crop ...tissue of male and female pigeons during incubation and chick-rearing periods. Forty-two pairs of adult White King pigeons with 2 fertile eggs per pair were randomly divided into 7 groups by different breeding stages. The AA content of crop milk decreased from day 1 (R1) to day 25 (R25) of chick rearing (P < 0.05). In both male and female adult pigeons, the contents of Thr, Leu, Val, His, Asp, and Pro in plasma increased to maximum levels on R25. Parental sex effect and interaction between stage and sex were observed in the AA contents of pigeon plasma (P < 0.05). For AA transporters, the mRNA abundances of SNAT2, ASCT1, LAT1, and y
LAT2 in the male crops reached the highest value on day 17 of incubation (I17), and the peak mRNA levels of PAT-1, xCT, b
AT, and CAT1 were found on R7 (P < 0.05). In females, the abundances of ASCT1, B
AT1, asc-1, and CAT1 mRNA peaked on R1, whereas the maximum levels of LAT1, PAT-1, b
AT, and y
LAT2 were observed on R7. For enzymes involved in AA synthesis, the highest gene expressions of glutamate dehydrogenase 1, acetolactate synthase in both parent pigeons, and L-threonine 3-dehydrogenase in female pigeon crops were attained on I17. The expressions of ornithine-δ-aminotransferase, glutamic-oxal(o)acetic transaminase 1, glutamic-oxal(o)acetic transaminase 2, asparagine synthetase, serine hydroxymethyltransferase 2, and glutamic-pyruvic transaminase 2 in both sexes and argininosuccinate lyase and L-threonine 3-dehydrogenase in males were the highest on R1. In conclusion, AA used for pigeon crop milk formation may originate from plasma and intracellular synthesis. The genes involved in AA transport and synthesis varied significantly with sexual effects, indicating that other factors should be considered in future explorations of the mechanism of protein formation in crop milk.
Summary
Background
Studies have showed that 10‐day sequential treatment regimen achieved higher Helicobacter pylori eradication rate than standard triple therapies.
Aim
To compare a 10‐day sequential ...therapy and standard triple therapy in Chinese children with H. pylori infection.
Methods
A prospective, multicentre, open‐label, randomised controlled trial was conducted in four tertiary medical centres in China. Children with H. pylori gastritis were randomly assigned to a 10‐day sequential therapy consisting of omeprazole and amoxicillin for 5 days followed by omeprazole, clarithromycin and metronidazole for the remaining 5 days, or 7‐day or 10‐day standard triple therapy comprising of omeprazole, amoxicillin and clarithromycin. H. pylori eradication was assessed by H. pylori stool antigen test.
Results
A total of 360 patients were included. The eradication rate achieved with the 10‐day sequential therapy was significantly higher than either the 7‐day or 10‐day standard triple treatment, either by the intention‐to‐treat analysis (81.4% vs. 61.9% or 67.7%, P < 0.05) or per‐protocol analysis (89.7% vs. 70.8% or 77.8%, P < 0.05).
Conclusions
The 10‐day sequential regimen was significantly more effective than standard 7‐day or 10‐day triple regimens in eradicating H. pylori infection in Chinese children.
PDF
