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The data on direct-acting antivirals (DAAs) in chronic hepatitis C (CHC) patients in southern China with multiple genotypes circulating are limited. This study aims to evaluate the efficacy and safety of DAA regimens among CHC patients in Guangdong, China. A total of 220 patients receiving a variety of DAA were enrolled. The primary outcome was sustained virologic response (SVR) at 12 weeks. Resistance associated substitutions (RASs) were evaluated by deep sequencing. The overall SVR rate was 96.4%, and was 97.7% for genotype 1, 100% for genotype 2, 91.9% for genotype 3, 95.7% for genotype 6, and 100% for untyped. The overall incidence of adverse events (AEs) was 8.2% (18/220) and all the AEs were mild. Nonstructural proteins 5A RAS, 30K/31M, and Y93H were most prevalent at baseline and the end of treatment in non-SVR patients, respectively. Logistics regression showed that elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) at baseline were specifically associated with non-SVR in patients with genotype 3 and 6 infections (p = 0.029 and p = 0.017) but not genotype 1 infection (p = 0.746 and p = 0.971), and baseline AST was the best predictor for SVR in genotypes 3 and 6 patients (area under curve = 0.890). Our studies demonstrated all DAA regimens achieved ideal SVR and were well tolerated. NS5A RAS were prevalent in non-SVR patients. Elevated ALT and AST as baseline predictors for non-SVR in genotypes 3 and 6 infections warrant further research in a larger cohort.

In the troposphere, the knowledge about nitrous acid (HONO) sources is incomplete. The missing source of sulfate and fine particles cannot be explained during haze events. Air quality models cannot predict high levels of secondary fine-particle pollution. Despite extensive studies, one challenging issue in atmospheric chemistry is identifying the source of HONO. Here, we present direct ab initio molecular dynamics simulation evidence and typical air pollution events of the formation of gaseous HONO, nitrogen dioxide/hydrogen sulfite (HOS(O)2-NO2 or NO2-HSO3) from nitrogen dioxide (NO2), sulfur dioxide (SO2), water (H2O), and ammonia (NH3) molecules in a proportion of 2:1:3:3. The reactions show a new mechanism for the formation of HONO and NO2-HSO3 in the troposphere, especially when the concentration of NO2, SO2, H2O, and NH3 is high (e.g., 2:1:3:3 or higher) in the air. Contrary to the proportion NO2, SO2, H2O, and NH3 equaling to 1:1:3:1 and 1:1:3:2, the proportion (2:1:3:3) enables barrierless reactions and weak interactions between molecules via the formation of HONO, NO2-HSO3, and NH3/H2O. In addition, field observations are carried out, and the measured data are summarized. Correlation analysis supported the conversion of NO2 to HONO during observational studies. The weak interactions promote proton transfer, resulting in the generation of HONO, NO2-HSO3, and NH3/H2O pairs.

Background Evaluate the safety and efficacy of 104-week regimen of Telbivudine(LdT)-based optimization strategy for Chinese patients who have chronic hepatits B(CHB) with HBeAg-negative. Methods This multi-center, open-label, prospective study enrolled 108 HBeAg-negative CHB patients who received LdT (600 mg/day) for 24 weeks, Adefovir (ADV) was added if HBV DNA remained detectable at week 24, otherwise LdT was maintained to use until 104 weeks. HBV DNA, alanine amino transferase (ALT), hepatitis B surface antigen(HBsAg), creatinine kinase(CK), and estimated glomerular filtration rate (eGFR) were measured, safety was assessed. Results Eighty-eight patients (81%) had HBV-DNA undetectable at 24 weeks and maintained to receive LdT monotherapy until 104 weeks, whereas the other 20 patients had HBV-DNA detectable and ADV was used in combination. For all patients, 72% of patients reached ALT normalization at 24 weeks, which increased to 80% at 52 weeks and 104 weeks, respectively.. 81% of total patients had undetectable HBV-DNA at 24 weeks, 92% at 52 weeks, and 94% at 104 weeks. The HBsAg titre declined steadily from baseline to 104 weeks (3.62 vs. 2.98 log10 IU/mL, p 2, p Conclusions LdT was well tolerated and effective, and 94% of patients achieved virological suppression after 104 weeks. Trial registration This study was registered in clinicaltrials.gov on January 31, 2012 and the ID No. was NCT01521975.

Hydroxyl free radicals (OH radicals) play the main role in atmospheric chemistry and their involving reactions are the dominant rate determining step in the formation of secondary fine particulate matter and in the removal of air pollutants from the atmosphere. In this paper, we studied the seasonal variation characteristics of OH radicals during the daytime in Lanzhou and explored the potential formation mechanism of high concentration OH radicals. We found that the OH radicals in four seasons was 2.7 × 106, 2.6 × 106, 3.1 × 106, and 2.2 × 106 cm−3, respectively. Since the rainfall was concentrated in summer, the wet deposition had a significant effect on removing OH radicals. Among the four pollutants (including ozone (O3), volatile organic compounds (VOCs), nitrogen dioxide (NO2) and fine particulate matter (PM2.5)), the variation of OH radicals were closely related to ozone concentration especially in spring and summer. In autumn, the correlation between PM2.5 and OH radicals were the closest among the observing pollutants and its formation mechanism was different conventional regeneration pathway. In Event 1, high concentration of ozone was the main source of OH radicals; under the high humidity condition, except for ozone, the multiple factors including VOCs, NO2 and PM2.5 interplayed and leaded to the Event 2.

Atmospheric particulate pollution in China has attracted much public attention. Occasionally, the particle number concentration increases sharply in a short time period, which is defined as a “particulate matter explosive increase”. Heavy particulate matter pollution not only reduces visibility but also has an adverse effect on human health. Hence, there is an urgent need to discover the causes of particulate matter explosive increase. During this campaign, the particle number concentration and free radicals were measured at a tall building on the campus of Lanzhou University of Technology. Additionally, we examined a series of chemicals to reproduce the observed particulate matter explosive increase in a smog chamber to determine its potential factors. Then, we analyzed the mechanism of particulate matter explosive increase in the presence of free radicals. We found that, among the potential inorganic and organic sources analyzed, a mixture of organic and SO2 in the research region had a major effect on particulate matter explosive increase. Moreover, free radical oxidation has a large effect, especially in the formation of organic particulates.

In the troposphere, the knowledge about nitrous acid (HONO) sources is incomplete. The missing source of sulfate and fine particles cannot be explained during haze events. Air quality models cannot predict high levels of secondary fine-particle pollution. Despite extensive studies, one challenging issue in atmospheric chemistry is identifying the source of HONO. Here, we present direct ab initio molecular dynamics simulation evidence and typical air pollution events of the formation of gaseous HONO, nitrogen dioxide/hydrogen sulfite (HOS(O)2-NO

Background An ongoing outbreak of coronavirus disease 2019 (COVID-19) has spread around the world. It is debatable whether asymptomatic COVID-19 virus carriers are contagious. We report here a case of the asymptomatic patient and present clinical characteristics of 455 contacts, which aims to study the infectivity of asymptomatic carriers. Material and methods 455 contacts who were exposed to the asymptomatic COVID-19 virus carrier became the subjects of our research. They were divided into three groups: 35 patients, 196 family members and 224 hospital staffs. We extracted their epidemiological information, clinical records, auxiliary examination results and therapeutic schedules. Results The median contact time for patients was four days and that for family members was five days. Cardiovascular disease accounted for 25% among original diseases of patients. Apart from hospital staffs, both patients and family members were isolated medically. During the quarantine, seven patients plus one family member appeared new respiratory symptoms, where fever was the most common one. The blood counts in most contacts were within a normal range. All CT images showed no sign of COVID-19 infection. No severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections was detected in 455 contacts by nucleic acid test. Conclusion In summary, all the 455 contacts were excluded from SARS-CoV-2 infection and we conclude that the infectivity of some asymptomatic SARS-CoV-2 carriers might be weak., Highlights • An asymptomatic SARS-CoV-2 carrier of nosocomial infection was confirmed. • All the 455 contacts were excluded from SARS-CoV-2 infection. • Infectivity of some asymptomatic SARS-CoV-2 carriers was probably weak.

Background: Coronavirus disease 2019 (COVID-19) is currently a global public health issue Cases of severe pneumonia caused by other coronaviruses were often as

Biomass-based nanofibers were prepared by electrospinning a mixture of polyacrylonitrile and acid-treated biomass from industrial hemp straw. The as-prepared biomass-based nanofibers were then carbonized and activated by high-temperature carbonization and KOH to obtain the activated biomass-based carbon nanofibers. The scanning electron microscopy images show that the precursors and carbon nanofibers are composed of fibers 179 nm in diameter, and the nitrogen adsorption/desorption measurements indicate that the carbon nanofibers possess a high-specific surface area of 2348.73 m2·g−1. The carbon nanofibers exhibit excellent electrical performance. The specific capacitance is as high as 244.8 F·g−1 at a current density of 1 A·g−1. The specific capacitance remains at 96% after 3000 cycles of charge and discharge at a current density of 2 A·g−1, showing excellent cycle stability. This work provides new ideas for the future development of supercapacitors electrode materials and enhances the development of biomass energy.

The low Pr-doped Bi2O3 photocatalyst was prepared via the acrylamide polymerisation method. The photocatalytic activity of prepared samples was evaluated by degrading methyl orange under visible-light irradiation. In comparison to α-Bi2O3 nanoparticles, 4% Pr-α-Bi2O3 photocatalyst exhibit obviously enhanced photocatalytic performance. The theoretical calculation and experimental results show that Pr doping can extend the optical absorption range from 436 to 518 nm and improve the photocatalytic efficiency from 40.9 to 70.4%. This long-wavelength response can be happened because of Pr doping that gives rise to the modification of electron structure and the hybridisation of the energy levels.

Free radicals play an important role in the oxidizing power of polluted air, the development of aging-related diseases, the formation of ozone, and the production of secondary particulate matter. The high variability of peroxyl radical concentration has prevented the detection of possible trends or distributions in the concentration of free radicals. We present a new method, free radical reaction combined with liquid chromatography photodiode array detection, for identifying and quantifying peroxyl radicals in polluted air. Functionalized graphene was used for loading peroxyl radicals and reactive molecules in air sampling system, which can facilitate reaction kinetics (charge transfers) between peroxyl radicals and reaction molecules. Separation was performed with and without a preliminary exposure of the polluted air sample to reactive molecule(s) system. The integral chromatographic peak areas before and after air sampling are used to quantify the atmospheric peroxyl radicals in polluted air. The utility of the new technique was tested with measurements carried out in the field.

Free radicals are the most important chemical intermediate or agent of the atmosphere and influenced by thousands of reactants. The free radicals determine the oxidizing power of the polluted air. Various gases present in smog or haze are oxidants and induce organ and cellular damage via generation of free radical species. At present, however, the high variability of total free radicals in polluted air has prevented the detection of possible trends or distributions in the concentration of those species. The total free radicals are a kind of contaminants with colorless, tasteless characteristics, and almost imperceptible by human body. Here we present total free radical detection and distribution characteristics, and analyze the effects of total free radicals in polluted air on human health. We find that the total free radical values can be described by not only a linear dependence on ozone at higher temperature period, but also a linear delay dependence on particulate matter at lower temperature period throughout the measurement period. The total free radical species distribution is decrease from west to east in Lanzhou, which closely related to the distribution of the air pollutants. The total free radical oxidation capacity in polluted air roughly matches the effects of tobacco smoke produced by the incomplete combustion of a controlled amount of tobacco in a smoke chamber. A relatively unsophisticated chromatographic fingerprint similarity is used for indicating preliminarily the effect of total free radicals in polluted air on human health.

A new polyaniline-modified β-Bi2O3 photocatalyst (PANI/β-Bi2O3 composite) was prepared via the chemical oxidative polymerization. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-Vis absorption spectra were used to characterize the phase structure, morphology, and optical properties of the samples, respectively. The photocatalytic activity of the prepared samples was evaluated by degrading Acid orange 7(AO 7), and the highest photocatalytic activity was shown by PB-3 (5%). Compared with pure β-Bi2O3, 30% photocatalytic activity can be improved by the PB-3. PANI modification can effectively enhance the photocatalytic activity of the β-Bi2O3. The possible photocatalytic mechanism of the PANI/β-Bi2O3 composite was proposed.

β-Bi2O3 particles were synthesized by a polyacrylamide sol–gel method. The sonocatalytic activity of β-Bi2O3 particles was evaluated by degrading Rhodamine B (RhB) under the ultrasonic irradiation, revealing that β-Bi2O3 particles exhibit a good sonocatalytic activity. The effects of various experimental factors including ultrasonic frequency (f), solution temperature (T), catalyst dosage (Ccatalyst) and initial RhB concentration (CRhB) on the sonocatalysis efficiency were investigated. The optimum conditions for sonocatalytic degradation of RhB are obtained to be f = 60 kHz, T = 40 °C, Ccatalyst = 3 g L−1, and CRhB = 5 mg L−1. The percentage degradation of RhB after sonocatalysis for 90 min is 98.7%. Detected by the photoluminescence technique that of using terephthalic acid as a probe molecule, hydroxyl radicals ( OH) are found to be produced on the irradiated by β-Bi2O3 particles. Based on the experimental results, OH radicals are suggested to be the major active species which are responsible for the degradation reaction.

β-Bi 2 O 3 nanoparticles with an average grain size of 100 nm were synthesized by a polyacrylamide sol–gel method. Their bandgap energy is obtained by ultraviolet–visible diffuse reflectance spectroscopy is 2.37 eV. β-Bi 2 O 3 /GR composites were fabricated by mixing β-Bi 2 O 3 nanoparticles and graphene into absolute ethanol solution followed by thermal drying. A transmission electron microscopy observation shows that β-Bi 2 O 3 nanoparticles are well assembled onto GR sheets. The photocatalytic activity of prepared samples was evaluated by degrading methylene blue under the irradiation of visible light. Compared to bare β-Bi 2 O 3 nanoparticles, β-Bi 2 O 3 /GR composites exhibit significantly enhanced photocatalytic activity. Detected by the photoluminescence technique that of using terephthalic acid as a probe molecule, hydroxyl ( OH) radicals are found to be produced on the irradiated β-Bi 2 O 3 /GR composites. Based on the experimental results, OH radicals are suggested to be the major active species which is responsible for the degradation reaction.

A glassy carbon electrode (GCE) was modified with graphene quantum dots (GQDs) carrying silver nanoparticles. The modified GCE displays excellent performance in the electrochemical oxidation of guanine and adenine in showing lower anodic peak overpotentials (of 0.625 and 0.929 V, respectively) and increased anodic peak currents. The effective surface area of the modified GCE is about 21.5 times larger than that of the bare GCE. The electron transfer coefficient (α) and the electron transfer number (n) were calculated to be 2 and 0.60 for guanine, and 2 and 0.64 for adenine, respectively. Linear relationships between peak current and the concentrations were obtained in the range from 0.015 to 430 μM (for guanine) and 0.015 to 390 μM (for adenine). The detection limits are 10 nM and 12 nM (at a signal-to-noise ratio of 3), respectively. The modified GCE can well distinguish between guanine and adenine in mixed solutions, has fast response, a low detection limit, good reproducibility, and high stability.

We have investigated the effects of O2, ethanol, and KI on the photocatalytic efficiency of Bi2Fe4O9 nanoparticles towards the degradation of methylene blue (MB). It is observed that O2 has a negligible effect on the photocatalytic degradation rate of the dye, whereas ethanol and KI exhibit a strong suppression of the dye degradation, with a stronger effect observed for the latter. Hydroxyl radicals are shown, by the photoluminescence technique using coumarin as a probe molecule, to be produced on the irradiated Bi2Fe4O9, and are scavenged on addition of ethanol and KI. The mechanisms involved are discussed in detail. Based on the experimental results, hydroxyl radicals and photogenerated holes are suggested to be the two main active species in the photocatalytic degradation of MB by Bi2Fe4O9 nanoparticles.

A novel free radical reaction combined with liquid chromatography electrospray ionization tandem mass spectrometry (FRR-LC-PDA-ESI/APCI-MS/MS) screening method was developed for the detection and identification of radical-scavenging natural antioxidants. Functionalized graphene was prepared by chemical method for loading free radicals (superoxide radical, peroxyl radical and PAHs free radical). Separation was performed with and without a preliminary exposure of the sample to specific free radicals on the functionalized graphene, which can facilitate reaction kinetics (charge transfers) between free radicals and potential antioxidants. The difference in chromatographic peak areas is used to identify potential antioxidants. The structure of the antioxidants in one sample (Swertia chirayita) is identified using MS/MS and comparison with standards. Thirteen compounds were found to possess potential antioxidant activity, and their free radical-scavenging capacities were investigated. The thirteen compounds were identified as 1,3,5-trihydroxyxanthone-8-O-β-D-glucopyranoside (PD1), norswertianin (PD2), 1,3,5,8-tetrahydroxyxanthone (PD3), 3, 3', 4', 5, 8-penta hydroxyflavone-6-β-D-glucopyranosiduronic acid-6'-pentopyranose-7-O-glucopyranoside (PD4), 1,5,8-trihydroxy-3-methoxyxanthone (PD5), swertiamarin (PS1), 2-C-β-D-glucopyranosyl-1,3,7-trihydroxylxanthone (PS2), 1,3,7-trihydroxylxanthone-8-O-β-D-glucopyranoside (PL1), 1,3,8-trihydroxyl xanthone-5-O-β-D-glucopyranoside (PL2), 1,3,7-trihydroxy-8-methoxyxanthone (PL3), 1,2,3-trihydroxy-7,8-dimethoxyxanthone (PL4), 1,8-dihydroxy-2,6-dimethoxy xanthone (PL5) and 1,3,5,8-tetramethoxydecussatin (PL6). The reactivity and SC50 values of those compounds were investigated, respectively. PD4 showed the strongest capability for scavenging PAHs free radical; PL4 showed prominent scavenging capacities in the lipid peroxidation processes; it was found that all components in S. chirayita exhibited weak reactivity in the superoxide radical scavenging capacity. The use of the free radical reaction screening method based on LC-PDA-ESI/APCI-MS/MS would provide a new approach for rapid detection and identification of radical-scavenging natural antioxidants from complex matrices.

In this study, a polyacrylamide gel route was introduced to synthesize TiO2 nanoparticles. The influence of synthesis conditions on the properties of products was investigated. It is found that the samples prepared at the calcination temperature of 400 °C crystallize majorly in the anatase phase with a minor rutile phase. The second rutile phase has a dependence on the chelating agent, which is formed more readily when using acetic acid as the chelating agent. The introduction of acrylamide and glucose to the precursor solution shows the capability of improving the particle morphology, and the resulted particles are uniformly shaped like spheres. The photocatalytic activity of the prepared TiO2 samples was evaluated by the degradation of acid orange 7 under 254 nm ultraviolet irradiation, revealing that they exhibit a good photocatalytic activity. Ethanol was used as a ·OH scavenger to investigate its effect on the photocatalytic efficiency as well as the ·OH radical yields. Based on the experimental results, ·OH radical is suggested to be the dominant active species responsible for the dye degradation.

A novel screening method was developed for the detection and identification of radical scavenging natural antioxidants based on a free radical reaction combined with liquid chromatography with tandem mass spectrometry. Functionalized graphene quantum dots were prepared for loading free radicals in the complex screening system. The detection was performed with and without a preliminary exposure of the samples to specific free radicals on the functionalized graphene quantum dots, which can facilitate charge transfer between free radicals and antioxidants. The difference in chromatographic peak areas was used to identify potential antioxidants. This is a novel approach to simultaneously evaluate the antioxidant power of a component versus a free radical, and to identify it in a vegetal matrix. The structures of the antioxidants in the samples were identified using tandem mass spectrometry and comparison with standards. Fourteen compounds were found to possess potential antioxidant activity, and their free radical scavenging capacities were investigated. The order of scavenging capacity of 14 compounds was compared according to their free radical scavenging rate. 4',5,6,7-Tetrahydroxyflavone (radical scavenging rate: 0.05253 mL mg(-1) s(-1) ) showed the strongest capability for scavenging free radicals.

To investigate the efficacy of anti-hepatitis B virus (HBV) drugs for preventing vertical transmission of HBV and the safety of these drugs when given as treatment during pregnancy (to women) or insemination (to men).Cases of women and men who had taken anti-HBV drug therapy during pregnancy or insemination, respectively, were retrospectively selected for study from among 18 hospitals and 33 specialists in the Guangdong Province. Demographic, HBV infection and treatment data was collected for puerperal men or women and their newborns from the medical records.A total of 122 cases with detailed follow-up data were included in the study and including 74 women who were administered lamivudine (LAM) more than telbivudine (LdT) more than adefovir (ADV)more than entecavir (ETV) (hierarchy ranking by number of cases) and 48 men who were administered LAM more than ADV more than LdT more than ETV.None of the 122 newborns related to these cases showed HBV infection at 7 months of follow-up.None of the 74 puerperal women showed complications related to reproduction.There was one ease of a newborn being underweight at birth (2.1 kg), for which the mother had taken LdT during pregnancy. There was also one case of a newborn with a harelip and one case of a newborn with an inguinal hernia, for which both of the fathers had taken ADV during the time of insemination.This retrospective investigation carried out in Guangdong Province indicated that not only are anti-HBV drugs efficacious for blocking vertical transmission of HBV but also are safe for both mothers and infants when taken by fathers or mothers during the reproduction phases of insemination and pregnancy.

The present study compared the efficacy of standard and extended durations of PEG-IFNα-2a monotherapy for treatment of HBeAg-negative Chinese patients with chronic hepatitis B. Patients were randomized to receive standard therapy (n = 38; 48 weeks treatment) or extended therapy (n = 42; 72 weeks treatment). Extended therapy resulted in a significantly higher HBV DNA inhibition at 24 and 48 weeks after the end of treatment, a significantly higher sustained HBV DNA inhibition at the end of treatment, and a significantly lower HBsAg level at 24 and 48 weeks after the end of treatment (P 0.05 for all comparisons). The HBsAg clearance rate was significantly greater in the extended therapy group than in the standard therapy group at 24 and 48 weeks post-treatment (33.3% vs. 10.5% and 35.7% vs. 10.5%, respectively; P 0.05 for both). In addition, patients with an increase of more than 1 log10 IU/ml in HBsAg level from baseline to week 24 had a significantly lower level of HBsAg at end of treatment (0.54 ± 1.76 vs. 2.89 ± 1.27, P 0.001), but a higher level of HBsAg clearance (64.3% vs. 7.6%, P 0.001). Assessment of HBsAg level at week 24 appears to be a suitable checkpoint. These results indicate that 72 weeks of PEG-IFNα-2a monotherapy benefits HBeAg-negative Chinese patients with chronic hepatitis B who are infected with HBV genotype B or C.

To detect and identify natural antioxidants in Swertia chirayita with protective effect against cerebral infarction, a screening method, using column chromatography and cerebral ischemia-reperfusion injury in rat, was developed. Seventeen compounds were purposefully separated and identified by Nuclear Magnetic Resonance, Fourier Transform Infrared Spectroscopy, Ultraviolet Spectrum, and Mass Spectrometry. The purified compounds were further screened by radical scavenging activity and cerebral ischemia-reperfusion injury in rats. Two compounds showed apparent radical scavenging activity and neuroprotective activity. The two compounds were identified as 1-hydroxy-2,3,4,6-tetramethoxyxanthone and 1,5,8-trihydroxy-3-methoxy xanthone, and were preliminarily considered as primary natural neuroprotective antioxidants in Swertia chirayita. These two compounds (20 mg kg−1) markedly decreased infarct size to below 5%, and also caused a significant improvement of activities of superoxide dismutase (SOD) (92.90 ± 11.19 U ml−1), glutathione peroxidase (GSH-Px) (122.58 ± 12.31 μmol mg−1) and a decrease in the content of malondialdehyde (MDA) (3.98 ± 2.00 nmol ml−1) in serum. The two compounds showed strong capability for protective effects against cerebral damages induced by ischemia-reperfusion, and the protective effect may be related to the inhibition of lipid peroxidation. The use of the screening method based on tracing separation and ischemia reperfusion would provide a new way for detection of radical-scavenging and natural neuroprotective compounds from Swertia chirayita or complex matrices.