Emergence and Autochthonous Transmission of Dengue Virus Type I in a Low-Epidemic Region in Southeast China.

Background: Dengue fever is a mosquito-borne febrile illness. Southeast Asia experienced severe dengue outbreaks in 2019, and over 1000 cases had been reported in Jiangxi, a previously known low-epidemic region in China. However, the emergence of a dengue virus epidemic in a non-epidemic region remains unclear. Methods: We enrolled 154 dengue fever patients from four hospitals in Jiangxi, from April 2019 to September 2019. Real-time PCR, NS1 antigen rapid test, and IgM, IgG tests were performed, and 14 samples were outsourced to be sequenced metagenomically. Results: Among the 154 cases, 42 were identified as imported and most of them returned from Cambodia. A total of 113 blood samples were obtained and 106 were identified as DENV-1, two as DENV-2, and five were negative through RT-PCR. All DENV-1 strains sequenced in this study were all classified to one cluster and owned a high similarity with a Cambodia strain isolated in 2019. The evolutionary relationships of amino acid were consistent with that of nucleotide genome result. The sequence-based findings of Jiangxi strains were consistent with epidemiological investigation. Conclusion: Epidemiological analysis demonstrated that the emergence of dengue cases led to autochthonous transmission in several cities in Jiangxi, a low-epidemic region before. This study emphasized future prevention and control of dengue fever in both epidemic and non-epidemic regions.

Geochemistry of heavy metal-contaminated sediments from the Four River inlets of Dongting lake, China.

The concentrations of major and trace elements in the sediments from the Four River inlets of Dongting Lake were analysed. The results show that the element compositions of the Four River inlet sediments are different, among which higher amounts of Al2O3, Fe2O3, MnO, Cs, Rb, Th, U, Y, and REE are found, while MgO, CaO, Na2O, and Sr are more depleted in the sediments from the Xiangjiang and Zijiang inlets than in the sediments from the Yuanjiang and Lishui inlets. The Xiangjiang inlet sediments are distinctly higher enriched (EF > 5.0) in heavy metals Bi, Cd, Mn, Cu, Pb, and Zn, while the other river sediments are moderately enriched (EF > 2.0) in these heavy metals. These geochemical differences are resulted from the source lithology, chemical weathering, hydrological sorting, and anthropogenic processes taking place in the watersheds. The principal component analysis and the geochemical vertical profiles suggest that the trace metals Ba, Mo, V, Cr, Co, Ni, Cs, Rb, Sc, Th, U, Ga, Ge, Zr, Hf, Ta, Nb, and REE are of terrigenous sources. The heavy metals including Bi, Cd, Mn, Cu, Pb, and Zn in the sediments can include those contributed by anthropogenic processes, such as mining and smelting of Pb-Zn ores. Therefore, presenting a scheme for the geochemical backgrounds of the watershed is recommended here for future assessment of the heavy metal contamination in sediments of the watershed.

A comparative study on the time to achieve negative nucleic acid testing and hospital stays between danoprevir and lopinavir/ritonavir in the treatment of patients with COVID-19.

In late December 2019, coronavirus disease 2019 (COVID-19) first broke out in Wuhan, China, and has now become a global pandemic. However, there is no specific antiviral treatment for COVID-19. This study enrolled 33 COVID-19 patients in the nineth hospital of Nanchang from 27th January to 24th February 2020. Clinical indexes of patients upon admission/discharge were examined. Patients were divided into two groups according to different treatment plans (danoprevir and lopinavir/ritonavir). The days to achieve negative nucleic acid testing and the days of hospital stays were counted and statistically analyzed. COVID-19 patients treated with danoprevir or lopinavir/ritonavir were all improved and discharged. Indexes like blood routine, inflammation and immune-related indexes were significantly recovered after treatment. Additionally, under the circumstance that there was no significant difference in patients' general information between the two groups, we found that the mean time to achieve both negative nucleic acid testing and hospital stays of patients treated with danoprevir were significantly shorter than those of patients with lopinavir/ritonavir. Collectively, applying danoprevir is a good treatment plan for COVID-19 patients.

[Clinical observation of telbivudine's antiviral efficacy and protection against mother-to-infant transmission of chronic hepatitis B during the first trimester of pregnancy].

OBJECTIVE: To explore the antiviral efficacy, safety and protective ability against mother-to-infant transmission of telbivudine in pregnant patients with chronic hepatitis B (CHB) during the first trimester. METHODS: Eighty four gravid women who were diagnosed with CHB, in their first trimester of pregnancy, and had refused to terminate their pregnancies were enrolled; all study participants were clinically classified as active hepatitis cases with positivity for both hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg), HBV DNA more than or equal to 107 copies/mL and serum level of alanine aminotarnsferase (ALT) of more than or equal to 4 ULN.Patients with YMDD mutations were excluded from the study. The study participants were divided into a telbivudine treatment group (n=43; administered in the first trimester of pregnancy) and a control group (n=41, consisting of patients who refused to take antivirals). All babies bom to the women in both groups of the study received standard immune prevention (anti-hepatitis B immunoglobulin plus hepatitis B vaccine) and artificial feeding.Data recorded for the women during pregnancy included clinical findings for tests of hepatic and renal function, myocardial enzymes, blood and urine clinical parameters, hepatitis B virus makers and HBV DNA, as well as notation of any adverse reactions. The neonates were evaluated for presence of HBV infection, parameters of growth and development, presence of complications, and Apgar score. At 6 and 12 months old, all infants were evaluated for HBV DNA level and HBsAg presence. RESULTS: The genetic variant rtM204I was detected in one of the women in the treatment group at 36 weeks of pregnancy. One woman in the control group developed severe hepatitis at 28 weeks of pregnancy and was put on the telbivudine treatment The treatment group showed greater recovery rates of ALT than the control group at 12 weeks of pregnancy (62.8% vs.29.3%, P=0.002), 24 weeks of pregnancy (76.7% vs.46.3%, P=0.000), and at ante partum (88.1% vs.60.0%, P=0.004). The treatment group also showed greater HBV DNA-negative conversion rates at 12 weeks of pregnancy (20.9% vs.0, P=0.006), at 24 weeks of pregnancy (37.2% vs.0, P=0.001) and at ante partum (78.6% vs.0, P=0.000), and greater HBeAg seroconversion rates at 12 weeks of pregnancy (2.3% vs.0, P=1.000), at 24 weeks of pregnancy (9.3% vs.0, P=0.116) and at ante partum (2 1.4% vs.0, P=0.002). The HBsAg-positive rates and HBV DNA-positive rates among the infants born to the mothers in the treatment and control groups, respectively, were 2.4% vs.17.5% (P=0.027) at birth, 0 vs.17.5% (P=0.005)at 6 months old and 0 vs.17.5% (P=0.005) at 12 months old. The Apgar scores were not significantly different for the children born to the mothers from the two groups, and all the children showed parameters of growth development within normal limits. CONCLUSION: Telbivudine administration in the first trimester had a good antiviral curative effect and effectively blocked mother-to-infant transmission in women with CHB. The treatment was safe, causing no obvious adverse reaction in the gravid women or developmental effects on the infants.

Cd isotopes as a potential source tracer of metal pollution in river sediments.

Tracing the sources of heavy metals in water environment is key important for our understanding of their pollution behavior. In this present study, Cd concentrations and Cd isotopic compositions in sediments were determined to effectively identify possible Cd sources. Results showed that elevated concentrations and high enrichment factor for Cd were found in all sediments, suggesting anthropogenic Cd origin. Cd isotopic compositions in sediments yielded relative variations ranged from -0.35‰ to 0.07‰ in term of δ(114/110)Cd (the mean: -0.08‰). Large fractionated Cd was found in sediments collected from a smelter and an E-waste town. Cd isotopic compositions and Cd concentrations measured in sediments allowed the identification of three main origins (dust from metal refining (δ(114/110)Cd < 0), slag of metal refining (δ(114/110)Cd > 0), and those δ(114/110)Cd = 0, such as background and mining activity). According to the actual precision obtained, Cd isotopes could be a potential tool for tracing metal pollution sources in water environment.

Lead isotopes as a tracer of Pb origin in the sediments from Beijiang River, South China.

Concentrations and enrichment of heavy metals were determined in sediments collected from Beijiang River, South China. The Pb isotopic compositions in these sediment samples were also employed to effectively identify metal pollution sources. According to the measured Pb concentrations, the total Pb concentrations in sediments varied from 62.1 to 1,152.5 µg/g, with an average concentration of 249.6 µg/g. The assessment by Geoaccumulation Index indicates that Pb is at the 'strongly contaminated' level, indicating that the Pb pollution was mainly due to anthropogenic inputs. The observed isotopic ratios varied from 1.174 to 1.204 for ²°6Pb/²°7Pb, 2.452 to 2.478 for ²°8Pb/²°7Pb, 18.404 to 18.937 for ²°6Pb/²°4Pb, 15.631 to 15.790 for ²°7Pb/²°4Pb, 38.455 to 39.121 for ²°8Pb/²°4Pb. The majority of these ratios are lower than those reported for natural geological sources, especially for sediments collected from a smelter. Significant correlation between Pb concentration and isotopic ratios suggested possible binary mixing of Pb. Combined with Pb concentration and enrichment levels, our results show that Pb pollution in the sediments of Beijiang River was mainly derived from anthropogenic sources. The mining activities and metal smelting processing was the main source of Pb pollution in this region.

Pt and Pd in sediments from the Pearl River Estuary, South China: background levels, distribution, and source.

PURPOSE: This study assessed the concentrations of platinum (Pt) and palladium (Pd) in surface sediments and sedimentary cores collected from the Pearl River Estuary with a view of evaluating the distribution, background levels, possible sources, and contamination level of anthropogenic Pt and Pd. MATERIALS AND METHODS: Thirty-six samples of surface sediments and 12 samples from sedimentary cores were collected. Al(2)O(3) was analyzed on fused glass disks by X-ray fluorescence spectrometer. Heavy metal elements were measured by inductively coupled plasma-mass spectrometry. Pt and Pd were separated from the sample matrix by anion exchange chromatography and subsequent solvent extraction after samples had been digested in Carius tubes using aqua regia. The analysis of Pt and Pd was performed by isotopic dilution-inductively coupled plasma-mass spectrometry. RESULTS AND DISCUSSION: Pt and Pd concentrations in surface sediments were 0.28-2.11 and 0.39-38.30 ng/g, respectively, and Pt and Pd concentrations in sedimentary cores were 0.19-1.18 and 0.15-1.76 ng/g, respectively. Background values of Pt and Pd were 0.20-1.17 and 0.10-1.34 ng/g, respectively. The spatial distribution of the enrichment factor differed between Pt and Pd in surface sediments. Down-core variations in Pt, Pd, and other heavy metal elements were similar in all cases and were related to sediment type. CONCLUSIONS: Some of the Pt and Pt in surface samples were derived from anthropogenic emissions. Pt and Pd were delivered to the sediment by fluvial input. In addition to vehicle exhaust catalysts, Pt and Pd were derived from other sources (e.g., industrial process). An important post-burial remobilization process of Pt and Pd is likely to be particle mixing by billows caused by typhoon.

Determination of rhenium content in molybdenite by ICP-MS after separation of the major matrix by solvent extraction with N-benzoyl-N-phenylhydroxalamine.

A simple and rapid analytical method for determining the concentration of rhenium in molybdenite for Re-Os dating was developed. The method used isotope dilution-inductively coupled plasma-mass spectrometry (ID-ICP-MS) after the removal of major matrix elements (e.g., Mo, Fe, and W) from Re by solvent extraction with N-benzoyl-N-phenylhydroxylamine (BPHA) in chloroform solution. The effect on extraction efficiency of parameters such as pH (HCl concentration), BPHA concentration, and extraction time were also assessed. Under the optimal experimental conditions, the validity of the separation method was accessed by measuring (187)Re/(185)Re values for a molybdenite reference material (JDC). The obtained values were in good agreement with previously measured values of the Re standard. The proposed method was applied to replicate Re-Os dating of JDC and seven samples of molybdenite from the Yuanzhuding large Cu-Mo porphyry deposit. The results demonstrate good precision and accuracy for the proposed method. The advantages of the method (i.e., simplicity, efficiency, short analysis time, and low cost) make it suitable for routine analysis.

Speciation and assessment of heavy metals in surface sediments of Jinjiang River tidal reach, southeast of China.

The concentration and speciation of heavy metals (Cr, Ni, Cu, Zn, Cd, Pb) in surface sediments (phi < or = 63 microm) of Jinjiang River tidal reach are determined to evaluate the metal behavior. A modified BCR three-step sequential extraction procedure is carried out, and the residual fraction is undertaken by microwave-assisted acid digestion. The index of geo-accumulation indicates that Cd appeared highest among all these heavy metals in surface sediments, Cr, Cu, Zn lower, and Ni, Pb the least. The percentage of Zn, Cd is comparatively higher in the acid soluble fraction, Pb and Cu higher in the reductive fraction, indicating larger potential danger to the environment. So it is essential for developing the future remediation plans and pollution control strategies.

[A noninvasive model to predict histological liver cirrhosis in patients with chronic hepatitis B].

OBJECTIVE: To construct a noninvasive model to predict histological liver cirrhosis in patients with chronic hepatitis B. METHODS: 275 patients with chronic hepatitis B were divided into a training group (206 cases) and a validation group (69 cases). The constituent ratios of patients in the fibrosis stages S0-S3, fibrosis stage S4 (early cirrhosis) and active cirrhosis stage were calculated according to the liver biopsy results. 30 noninvasive variables, including age-platelet index (API), aspartate aminotransferase to platelet ratio index (APRI), spleen-platelet ratio index (SRPI) and age-spleen-platelet ratio index (ASPRI), were analyzed by univariate analysis and multivariate logistic regression. Variables that were significantly different between patients with and without cirrhosis were used to construct a noninvasive prediction model, and the model was then tested in the validation group. RESULTS: (1) Of the 275 patients with chronic hepatitis B, 193 (70.2%) were in the fibrosis stages S0-S3, 42 (15.3%) in fibrosis stage S4, 40 (14.5%) in active cirrhosis stage. (2) There were 23 variables that are significantly different between patients with and without cirrhosis by univariate analysis. The 23 variables were further analyzed by multivariate logistic regression, and 4 independent factors, including international normalized ratio (INR), gamma glutamyltranspeptidase (GGT), ASPRI, hepatitis B e antigen (HBeAg) were used to construct a noninvasive prediction model. (3) By receiver operating characteristic curves (ROC) analysis, to discriminate patients in stages S0-S3 from patients in stage S4 and patients in active cirrhosis stage, the area under ROC (AUROC), cut-off value, sensitivity, specificity and accuracy of the model were 0.871, 0.458, 84.4%, 75.7%, and 79.7% respectively. To discriminate patients in active cirrhosis stage from patients in other stages, the AUROC, cut-off value, sensitivity, specificity and accuracy were 0.753, 0.526, 81.8%, 62.9%, and 67.4% respectively. There was no significant difference in AUROC between the training group and the validation group (P less than 0.05). CONCLUSION: INR, GGT, ASPRI and HBeAg are associated with early cirrhosis and active cirrhosis. Our model can be used to predict early cirrhosis and active cirrhosis.

Heavy metal pollution in intertidal sediments from Quanzhou Bay, China.

The concentrations of eight heavy metals (Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As) in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanization and economic development of Quanzhou region, southeast China. The ranges of the measured concentrations in the sediments are as follows: 24.8-119.7 mg/kg for Cu, 105.5-241.9 mg/kg for Zn, 34.3-100.9 mg/kg for Pb, 0.28-0.89 mg/kg for Cd, 51.1-121.7 mg/kg for Cr, 16.1-45.7 mg/kg for Ni, 0.17-0.74 mg/kg for Hg, and 17.7-30.2 mg/kg for As. The overall average concentrations of above metals exceed the primary standard criteria but meet the secondary standard criteria of the Chinese National Standard of Marine Sediment Quality. Several contents of Cu and Hg exceed the secondary standard criteria at some stations. The results of geoaccumulation index (Igeo) show that Cd causes strong pollution in most of the study area. There are no significant correlations among most of these heavy metals, indicating they have different anthropogenic and natural sources. Some locations present severe pollution by heavy metals depending on the sources, of which sewage outlets, aquatic breeding, and commercial ports are the main sources of contaminants to the area.