The physical nature (e.g. crystal size or surface atomic arrangement) of an electrocatalyst is central to the performance of electrochemical devices such as fuel cells and lithium-air batteries. This ...is particularly true in electrodes for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), which involve multiple elementary steps and a substantial energy barrier. As a result, OER and ORR generally are rate-limiting step in electrode reactions. Here, we show Au nanocrystals enclosed by high-index facets (e.g. {310}) are more energetically and kinetically favorable than {111} facets for oxygen reduction in both lithium-air battery and fuel cell conditions. In both systems, the electric potential for oxygen reduction was reduced by 60–160mV and the current increases by more than five times if high-index Au nanocrystals were utilized. These Au nanocrystals were synthesized at a temperature greater than the boiling point of ethylene glycol, the solvent used in this work. This synthetic approach opens a new reproducible route to synthesize nanocrystals with high-index facets because it is facile, rapid, and results in a large-quantity of nanocrystals with control over the size and morphology.
The shape and surface structures of gold nanocrystals enclosed by high-index facets, and the electrochemical properties of these crystals.
Au nanocrystals enclosed by high-index facets (e.g. {310}) are more energetically and kinetically favorable than {111} facets for oxygen reduction in both lithium-air battery and fuel cell conditions. In both systems, the electric potential for oxygen reduction was reduced by 60–160mV and the current increases by more than five times if high-index Au nanocrystals were utilized. Display omitted
•Gold nanocrystals with high-index facets are synthesized at a temperature greater than the boiling point of ethylene glycol.•Au nanocrystals with {310} facets are more energetically and kinetically favorable than {111} facets for ORR in lithium-air battery and fuel cell.•The electric potential for ORR is reduced by 60–160mV if high-index Au nanocrystals are utilized.
Tree-rings are often assumed to approximate a circular shape when estimating forest productivity and carbon dynamics. However, tree rings are rarely, if ever, circular, thereby possibly resulting in ...under- or over-estimation in forest productivity and carbon sequestration. Given the crucial role played by tree ring data in assessing forest productivity and carbon storage within a context of global change, it is particularly important that mathematical models adequately render cross-sectional area increment derived from tree rings. We modeled the geometric shape of tree rings using the superellipse equation and checked its validation based on the theoretical simulation and six actual cross sections collected from three conifers. We found that the superellipse better describes the geometric shape of tree rings than the circle commonly used. We showed that a spiral growth trend exists on the radial section over time, which might be closely related to spiral grain along the longitudinal axis. The superellipse generally had higher accuracy than the circle in predicting the basal area increment, resulting in an improved estimate for the basal area. The superellipse may allow better assessing forest productivity and carbon storage in terrestrial forest ecosystems.
Background and Aim
Although treatment with direct‐acting antivirals has dramatically improved morbidity and mortality attributable to chronic hepatitis C virus infection, universal access to these ...medicines has been slow in the Asia–Pacific region and Russia. This study evaluated efficacy and safety of elbasvir/grazoprevir in participants with hepatitis C virus infection from Asia–Pacific countries and Russia (C‐CORAL).
Methods
C‐CORAL was a phase 3, randomized, placebo‐controlled study (NCT02251990). Treatment‐naive, HIV‐negative, cirrhotic and non‐cirrhotic participants with chronic hepatitis C genotype 1, 4, or 6 infection were randomized to elbasvir 50 mg/grazoprevir 100 mg once daily for 12 weeks (immediate‐treatment group) or placebo followed by deferred treatment with elbasvir/grazoprevir (deferred‐treatment group). The primary efficacy outcome was sustained virologic response at 12 weeks, and the primary safety outcome was a comparison between the immediate‐treatment group and placebo phase of the deferred‐treatment group.
Results
A total of 489 participants were randomized (immediate‐treatment group, n = 366; deferred‐treatment group, n = 123). Sustained virologic response at 12 weeks in the combined immediate/deferred‐treatment groups was 94.4% (459/486; 95% confidence interval = 92.4–96.5%). Sustained virologic response at 12 weeks was 98.2% in participants with genotype 1b, 91.9% with genotype 1a, and 66.7% with genotype 6 infection. Similar rates of adverse events and drug‐related adverse events were seen in the immediate‐treatment group versus placebo phase of the deferred‐treatment group (51.0% vs 50.4% and 21.4% vs 21.1%).
Conclusions
Elbasvir/grazoprevir for 12 weeks represents an effective and well‐tolerated treatment option for treatment‐naive people with genotype 1 infection from Asia–Pacific countries and Russia.
Amperometric biosensors were prepared by immobilizing heme proteins in single-wall carbon nanotubes (SWCNTs)-cetyltrimethyl ammonium bromide (CTAB) surfactant films based on ...1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF
6) as nonaqueous electrolyte. The electrochemistry and electrocatalysis of protein-SWCNTs-CTAB films were investigated. A pair of well-defined and nearly reversible redox peaks was observed when the heme protein films were immersed into bmimPF
6. Moreover, the electrocatalytic activity of heme proteins for two model peroxides compounds (hydrogen peroxide (H
2O
2) and
tert-butyl hydroperoxide (
t-BuOOH)) was observed. Some electrocatalytic parameters for heme proteins were calculated. Compared with the detection results of
t-BuOOH in other organic solvents, kinetic analysis in this experiment indicates that heme protein-SWCNTs-CTAB films operated in ionic liquid provide a higher affinity and sensitivity.
Granites of the Mesozoic Era are widespread in South China, and many of them have been shaped into spectacular landscapes with high tourism development values. However, the controlling factors and ...evolution stages of these granite landscapes were poorly understood. In this study, the Hypsometric Integral curves (HIc), and Hypsometric Integral (HI) values of the Mount Wugong were extracted from digital elevation model data in a geographic information system environment. The relationships between the HCs, HI values, and factors including the tectonism, lithology and climate of the study area were analyzed to determine the evolution of granite landscapes evolution in the main scenic areas of the Mount Wugongshan. The HI values on the northwestern and southeastern slopes of the Mount Wugongshan range from 0.223 to 0.415 and 0.385 to 0.465, respectively; the HCs are mainly concave on the northwestern slopes and irregularly ‘S-shaped’ on the southeastern slopes. The main ridge of the granite geomorphic scenic area of the Mount Wugongshan, where the alpine meadow geomorphic landscape is located, is in the youthful stage of geomorphic evolution, the Mt. Jinding-Mt. Wanlong and Mt. Mingyue-Wentang scenic areas are in the old stage, and the Yangshimu scenic area is in the mature stage. Differences in watershed scale may be the main reason for the variabilities in geomorphic evolution in the area, while the regular development of tectonic phenomena is a key factor shaping the spatial variability in the watersheds on both sides of the main ridge.
A fluorescence assay is described for the fluorometric determination of dopamine (DA). It based on the use of silica-coated CdTe quantum dots (QD@SiO
2
). These were fabricated through a hydrothermal ...process. When DA is added to a solution of the QD@SiO
2
and then oxidized by oxygen under catalytic action of tyrosinase to form dopamine quinone, the fluorescence of QD@SiO
2
(acquired at excitation/emission wavelengths of 310/525 nm) decreases due to an electron transfer quenching processes. The assay has a linear calibration plot in the 0.05 to 30 μM DA concentration range and a 12.5 nM detection limit (at an S/N ratio of 3). The method was applied to the determination of DA in spiked human serum samples.
Graphical abstract
Schematic presentation of a fluorometric dopamine (DA) assay by using silica-coated CdTe QDs (QD@SiO
2
). DA is oxidized by oxygen under catalytic action of tyrosinase to form dopamine quinone, and this causes the quenching of fluorescence of QD@SiO
2
at excitation/emission wavelengths of 310/525 nm.
Objective
No brand direct-acting antiviral agents (DAAs) are available for treatment of HIV-1/HCV co-infected patients in China. This study aimed to observe the therapeutic efficacy and safety of ...generic DAAs for affected Chinese patients.
Design
Real-world setting to elucidate whether DAAs were tolerated and effective in HIV-1/HCV co-infected patients.
Methods
176 HIV-1/HCV co-infected patients received anti-HCV DAA treatment together with ART regimens for HIV infection. Among the 176 patients, 99 patients were treated with SOF + DCV ± RBV, 60 patients were treated with SOF + LDV ± RBV, and 17 patients received SOF + RBV ± Peg-IFN regimens, for 12 or 24 weeks, respectively. The primary endpoint was undetectable HCV RNA 12 weeks after therapy was completed (SVR12). Data pertaining to safety and adverse events were analyzed.
Results
151/176 HIV-1/HCV co-infected patients finished the treatment and 12-week follow-up. SVR12 for the patients treated with regimens of SOF + DCV, SOF + DCV+RBV, SOF + Peg-IFN+RBV, SOF + RBV, SOF + LDV, and SOF + LDV+RBV for 12 or 24 weeks was 100% (75/75), 100% (11/11), 100% (14/14), 100% (2/2), 95.2% (40/42), and 100% (7/7), respectively. HIV-1/HCV co-infected patients with liver cirrhosis achieved well SRV12. Notably, there was no significant difference in adverse effects among patients with different baseline CD4
+
T-cell count in those who received DAA regimens with or without Peg-IFN and RBV.
Conclusion
We showed generic SOF + DCV and SOF + LDV regimens were well tolerated and with high efficiency. Patient’s baseline CD4
+
T-cell count did not exhibit significant difference in adverse effects.
Phosphorylcholine (PC) based polymer coatings with excellent biocompatibility have shown successful commercialization in drug-eluting stents. However, poor degradability represents a challenge in the ...application of biodegradable stents. Herein, a biodegradable phosphorylcholine copolymer is developed based on one-step radical ring-opening polymerization (RROP). This copolymer was synthesized by copolymerization of a PC unit, degradable ester (2-methylene-1,3-dioxepane, MDO) unit and non-degradable butyl methacrylate (BMA) unit, which showed ratio controllability by changing the monomer ratio during polymerization. We demonstrated that the copolymer with the ratio of 34% MDO, 19% MPC and 47% BMA could form a stable coating by ultrasonic spray, and showed good blood compatibility, anti-adhesion properties, biodegradability, and rapamycin eluting capacity. In vivo study revealed its promising application as a biodegradable stent coating. This work provides a facile path to add biodegradability into PC based polymers for further bio-applications.
Background
Populations of natural killer cells lacking CD56 expression CD56
neg
natural killer (NK) cells have been demonstrated to expand during human immunodeficiency virus (HIV)-1 infection. ...However, their phenotypic and functional characteristics have not been systematically analyzed, and their roles during disease progression remain poorly understood.
Methods
In this study, 84 donors, namely 34 treatment-naïve HIV-1-infected patients (TNs), 29 HIV-1-infected patients with successful antiretroviral therapy (ARTs), and 21 healthy controls (HCs), were enrolled. The phenotypic and functional characteristics of CD56
neg
NK cells were analyzed using single-cell RNA-sequencing (scRNA-seq) and flow cytometry. A potential link between the characteristics of CD56
neg
NK cells and the clinical parameters associated with HIV-1 disease progression was examined.
Results
The frequency of the CD56
neg
NK cell population was significantly increased in TNs, which could be partially rescued by ART. Flow cytometry analyses revealed that CD56
neg
NK cells were characterized by high expression of CD39, TIGIT, CD95, and Ki67 compared to CD56
dim
NK cells.
In vitro
assays revealed reduced IFN-γ and TNF-α secretion, as well as decreased expression of granzyme B and perforin in CD56
neg
NK cells. In line with the data obtained by flow cytometry, scRNA-seq analysis further demonstrated impaired cytotoxic activities of CD56
neg
NK cells. Notably, a negative correlation was observed between CD39, CD95, and Ki67 expression levels in CD56
neg
NK cells and CD4
+
T cell counts.
Conclusions
The results presented in this study indicate that the CD56
neg
NK cell population expanded in HIV-1-infected individuals is dysfunctional and closely correlates with HIV-1 disease progression.
In the past decade, there has been extensive global surveillance for highly pathogenic avian influenza (HPAI) infection in both animals and humans, however, few studies on epidemiology of avian ...influenza in Democratic People's Republic of Korea (DPRK) were published. During the period 2013–2014, HPAI H5N1 viruses were detected with outbreaks in domestic poultry in DPRK. Phylogenetic analysis revealed that the hemagglutinin gene of all samples belonged to clade 2.3.2.1c with high homology. The HPAI H5N1 virus found in ducks at the Tudan Duck Farm in 2013 was might introduced by migratory birds and then led to the outbreaks on neighboring chicken farms in 2014. These data provide direct evidence for the transmission of avian influenza viruses from wild birds to waterfowl to terrestrial birds. Therefore, the monitoring and control of influenza virus in ducks must be given top priority, which are essential components to prevent and control HPAI.
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