Herein, ionomer-free amorphous iridium oxide (IrOx) thin electrodes are first developed as highly active anodes for proton exchange membrane electrolyzer cells (PEMECs) via low-cost, environmentally friendly, and easily scalable electrodeposition at room temperature. Combined with a Nafion 117 membrane, the IrOx-integrated electrode with an ultralow loading of 0.075 mg cm-2 delivers a high cell efficiency of about 90%, achieving more than 96% catalyst savings and 42-fold higher catalyst utilization compared to commercial catalyst-coated membrane (2 mg cm-2). Additionally, the IrOx electrode demonstrates superior performance, higher catalyst utilization and significantly simplified fabrication with easy scalability compared with the most previously reported anodes. Notably, the remarkable performance could be mainly due to the amorphous phase property, sufficient Ir3+ content, and rich surface hydroxide groups in catalysts. Overall, due to the high activity, high cell efficiency, an economical, greatly simplified and easily scalable fabrication process, and ultrahigh material utilization, the IrOx electrode shows great potential to be applied in industry and accelerates the commercialization of PEMECs and renewable energy evolution.
Introduction: The impact of intergenerational caregiving on the mental health of providers remains a controversial topic, especially in countries like China where it is prevalent. Given the country's aging population and recent liberalization of the two-child policy, understanding the effects of intergenerational caregiving on the mental health of middle-aged and older adult(s) individuals is crucial. This study aimed to explore the impact of intergenerational caregiving on mental health among middle-aged and older adult(s) individuals. Methods: We analyzed data from the China Health and Aging Tracking Survey (CHARLS) 2013, consisting of 6602 participants finally. Personal information, family structure, financial support, health status, and physical measurements were selected for analysis. Correlation and regression analyses were used for relationships among variables controlling for potential confounding variables. Mental health status was evaluated using the depression self-rating scale. Results: There is a significant positive effect of intergenerational care on the mental health of middle-aged and older adult(s) people. Additionally, we re-profiled intergenerational care variables by considering the number and length of intergenerational caregivers, and found that the effects remained significant. Furthermore, the effects of intergenerational care vary across subgroups based on gender, age, nature of usual residence, marital status, and physical health status. Finally, we identified two mechanisms through which intergenerational caregiving positively affects mental health: intergenerational financial support and intergenerational spiritual support. Discussion: These findings have important implications for policymakers, healthcare professionals, and family members in promoting the mental health of middle-aged and older adult(s) individuals in China.
Intergenerational Relations , Mental Health , Middle Aged , Humans , Aged , Aging/psychology , Health Status , China
Nanostructured catalyst-integrated electrodes with remarkably reduced catalyst loadings, high catalyst utilization and facile fabrication are urgently needed to enable cost-effective, green hydrogen production via proton exchange membrane electrolyzer cells (PEMECs). Herein, benefitting from a thin seeding layer, bottom-up grown ultrathin Pt nanosheets (Pt-NSs) were first deposited on thin Ti substrates for PEMECs via a fast, template- and surfactant-free electrochemical growth process at room temperature, showing highly uniform Pt surface coverage with ultralow loadings and vertically well-aligned nanosheet morphologies. Combined with an anode-only Nafion 117 catalyst-coated membrane (CCM), the Pt-NS electrode with an ultralow loading of 0.015 mgPt cm-2 demonstrates superior cell performance to the commercial CCM (3.0 mgPt cm-2), achieving 99.5% catalyst savings and more than 237-fold higher catalyst utilization. The remarkable performance with high catalyst utilization is mainly due to the vertically well-aligned ultrathin nanosheets with good surface coverage exposing abundant active sites for the electrochemical reaction. Overall, this study not only paves a new way for optimizing the catalyst uniformity and surface coverage with ultralow loadings but also provides new insights into nanostructured electrode design and facile fabrication for highly efficient and low-cost PEMECs and other energy storage/conversion devices.
Highly efficient electrodes with simplified fabrication and low cost are highly desired for the commercialization of proton exchange membrane electrolyzer cells (PEMECs). Herein, highly porous Ir-coated thin/tunable liquid/gas diffusion layers with honeycomb-structured catalyst layers were fabricated as anode electrodes for PEMECs via integrating a facile and fast electroplating process with efficient template removal. Combined with a Nafion 117 membrane, a low cell voltage of 1.842 V at 2000 mA/cm2 and a high mass activity of 4.16 A/mgIr at 1.7 V were achieved with a low Ir loading of 0.27 mg/cm2, outperforming most of the recently reported anode catalysts. Moreover, the thin electrode shows outstanding stability at a high current density of 1800 mA/cm2 in the practical PEMEC. Moreover, with in-situ high-speed visualizations in PEMECs, the catalyst layer structure's impact on real-time electrochemical reactions and mass transport phenomena was investigated for the first time. Increased active sites and improved multiphase transport properties with favorable bubble detachment and water diffusion for the honeycomb-structured electrode are revealed. Overall, the significantly simplified ionomer-free honeycomb thin electrode with low catalyst loading and remarkable performance could efficiently accelerate the industrial application of PEMECs.
In situ and micro-scale visualization of electrochemical reactions and multiphase transports on the interface of porous transport electrode (PTE) materials and solid polymer electrolyte (SPE) has been one of the greatest challenges for electrochemical energy conversion devices, such as proton exchange membrane electrolyzer cells (PEMECs), CO2 reduction electrolyzers, PEM fuel cells, etc. Here, an interface-visible characterization cell (IV-CC) is developed to in situ visualize micro-scaled and rapid electrochemical reactions and transports in PTE/SPE interfaces. Taking the PEMEC of a green hydrogen generator as a study case, the unanticipated local gas blockage, micro water droplets, and their evolution processes are successfully visualized on PTE/PEM interfaces in a practical PEMEC device, indicating the existence of unconventional reactant supply pathways in PEMs. Further comprehensive results reveal that PEM water supplies to reaction interfaces are significantly impacted with current densities. These results provide critical insights about the reaction interface optimization and mass transport enhancement in various electrochemical energy conversion devices.
Electrochemical conversion of nitrogen to green ammonia is an attractive alternative to the Haber-Bosch process. However, it is currently bottlenecked by the lack of highly efficient electrocatalysts to drive the sluggish nitrogen reduction reaction (N2RR). Herein, we strategically design a cost-effective bimetallic Ru-Cu mixture catalyst in a nanosponge (NS) architecture via a rapid and facile method. The porous NS mixture catalysts exhibit a large electrochemical active surface area and enhanced specific activity arising from the charge redistribution for improved activation and adsorption of the activated nitrogen species. Benefiting from the synergistic effect of the Cu constituent on morphology decoration and thermodynamic suppression of the competing hydrogen evolution reaction, the optimized Ru0.15Cu0.85 NS catalyst presents an impressive N2RR performance with an ammonia yield rate of 26.25 µg h-1 mgcat.-1 (corresponding to 10.5 µg h-1 cm-2) and Faradic efficiency of 4.39% as well as superior stability in alkaline medium, which was superior to that of monometallic Ru and Cu nanostructures. Additionally, this work develops a new bimetallic combination of Ru and Cu, which promotes the strategy to design efficient electrocatalysts for electrochemical ammonia production under ambient conditions.
For a proton exchange membrane electrolyzer cell (PEMEC), conditioning is an essential process to enhance its performance, reproducibility, and economic efficiency. To get more insights into conditioning, a PEMEC with Ir-coated gas diffusion electrode (IrGDE) was investigated by electrochemistry and in situ visualization characterization techniques. The changes of polarization curves, electrochemical impedance spectra (EIS), and bubble dynamics before and after conditioning are analyzed. The polarization curves show that the cell efficiency increased by 9.15% at 0.4 A/cm2, and the EIS and Tafel slope results indicate that both the ohmic and activation overpotential losses decrease after conditioning. The visualization of bubble formation unveils that the number of bubble sites increased greatly from 14 to 29 per pore after conditioning, at the same voltage of 1.6 V. Under the same current density of 0.2 A/cm2; the average bubble detachment size decreased obviously from 35 to 25 µm. The electrochemistry and visualization characterization results jointly unveiled the increase of reaction sites and the surface oxidation on the IrGDE during conditioning, which provides more insights into the conditioning and benefits for the future GDE design and optimization.
An anode electrode concept of thin catalyst-coated liquid/gas diffusion layers (CCLGDLs), by integrating Ir catalysts with Ti thin tunable LGDLs with facile electroplating in proton exchange membrane electrolyzer cells (PEMECs), is proposed. The CCLGDL design with only 0.08 mgIr cm-2 can achieve comparative cell performances to the conventional commercial electrode design, saving ≈97% Ir catalyst and augmenting a catalyst utilization to ≈24 times. CCLGDLs with regulated patterns enable insight into how pattern morphology impacts reaction kinetics and catalyst utilization in PEMECs. A specially designed two-sided transparent reaction-visible cell assists the in situ visualization of the PEM/electrode reaction interface for the first time. Oxygen gas is observed accumulating at the reaction interface, limiting the active area and increasing the cell impedances. It is demonstrated that mass transport in PEMECs can be modified by tuning CCLGDL patterns, thus improving the catalyst activation and utilization. The CCLGDL concept promises a future electrode design strategy with a simplified fabrication process and enhanced catalyst utilization. Furthermore, the CCLGDL concept also shows great potential in being a powerful tool for in situ reaction interface research in PEMECs and other energy conversion devices with solid polymer electrolytes.
Anion-exchange membrane electrolyzer cells (AEMECs) are one of the most promising technologies for carbon-neutral hydrogen production. Over the past few years, the performance and durability of AEMECs have substantially improved. Herein, we report an engineered liquid/gas diffusion layer (LGDL) with tunable pore morphologies that enables the high performance of AEMECs. The comparison with a commercial titanium foam in the electrolyzer indicated that the engineered LGDL with thin-flat and straight-pore structures significantly improved the interfacial contacts, mass transport, and activation of more reaction sites, leading to outstanding performance. We obtained a current density of 2.0 A/cm2 at 1.80 V with an efficiency of up to 81.9% at 60 °C under 0.1 M NaOH-fed conditions. The as-achieved high performance in this study provides insight to design advanced LGDLs for the production of low-cost and high-efficiency AEMECs.
Exploring cost-effective and efficient bifunctional electrocatalysts via simple fabrication strategies is strongly desired for practical water splitting. Herein, an easy and fast one-step electrodeposition process is developed to fabricate W-doped NiFe (NiFeW)-layered double hydroxides with ultrathin nanosheet features at room temperature and ambient pressure as bifunctional catalysts for water splitting. Notably, the NiFeW nanosheets require overpotentials of only 239 and 115 mV for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively, to reach a current density of 10 mA/cm2 in alkaline media. Their exceptional performance is further demonstrated in a full electrolyzer configuration with the NiFeW as both anode and cathode catalysts, which achieves a low cell voltage of 1.59 V at 10 mA/cm2, 110 mV lower than that of the commercial IrO2 (anode) and Pt (cathode) catalysts. Moreover, the NiFeW nanosheets are superior to various recently reported bifunctional electrocatalysts. Such remarkable performances mainly ascribe to W doping, which not only effectively modulates the electrocatalyst morphology but also engineers the electronic structure of NiFe hydroxides to boost charge-transfer kinetics for both the OER and HER. Hence, the ultrathin NiFeW nanosheets with an efficient fabrication strategy are promising as bifunctional electrodes for alkaline water electrolyzers.
BACKGROUND: High-quality evidence confirms that the clinical efficacy of peramivir in severe influenza patients with primary viral pneumonia is lacking. To optimize clinical medication, we evaluate the different efficacy between peramivir and oseltamivir in the treatment of severe influenza A with primary viral pneumonia. METHODS: A single-center, randomized, controlled trial was conducted during the Chinese influenza season from December 2018 to April 2019 in patients with severe influenza A with primary viral pneumonia. A total of 40 inpatients were enrolled and treated with either intravenous peramivir (300 mg, once daily for 5 days) or oral oseltamivir (75 mg, twice daily for 5 days). RESULTS: The duration of influenza virus nucleic acid positivity in the oseltamivir group and the peramivir group was 2.95 days and 2.80 days, respectively. The remission times of clinical symptoms in the oseltamivir group and the peramivir group were 3.90 days and 3.25 days, respectively. In addition, the remission time of cough symptoms in the peramivir group (63.89 hours) was shorter than that in the oseltamivir group (75.53 hours). There was no significant difference between these values (Pâ >â .05). The remission time of fever symptoms in the oseltamivir group was 23.67 hours, which was significantly longer than that in the peramivir group (12.32 hours) (Pâ =â .034). CONCLUSIONS: Peramivir is no less effective than oseltamivir in the treatment of severe influenza A with primary viral pneumonia, and patients treated with peramivir had significantly shorter remission times of fever symptoms than those treated with oseltamivir.
OBJECTIVE: To carry out the meta-analysis on the clinical safety of glycyrrhizic acid and the influencing factors between 18α-glycyrrhizinate (18α-GL) and 18ß-glycyrrhizinate (18ß-GL). METHODS: Magnesium isoglycyrrhizinate injection was used as the representative preparation of 18α-GL, and compound glycyrrhizin injection was used as the representative preparation of 18ß-GL. The clinical control trial of magnesium isoglycyrrhizinate injection and compound glycyrrhizin injection was searched in a computer, which was published from January 2006 to December 2019 on the databases such as PubMed, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (CSTJ), and Wanfang Medical Network (Wanfang Data). The data associated with adverse drug reactions (ADRs) were extracted. RevMan5.3 was used for statistical analysis. RESULTS: Finally, 24 studies were included, and 2757 patients were involved, of which the experimental group was mainly treated with magnesium isoglycyrrhizinate, while the control group was mainly treated with compound glycyrrhizin. The results showed that the occurrence of ADRs was significantly lower in the experimental group than that in the control group, and the difference between two groups was statistically significant (RR = 0.26, 95% CI = (0.18, 0.38), P < 0.00001). There was no heterogeneity among the studies (I 2 = 0%, P=1.00). CONCLUSION: Compared with 18ß-GL, 18α-GL had a lower incidence of adverse reactions and better clinical safety.
Objective: To evaluate the difference of clinical efficacy of peramivir alone and peramivir combined with immunomodulators (either ribonucleic acid or thymopetidum) in the treatment of severe influenza A with primary viral pneumonia. Methods: A retrospective analysis was applied to 45 patients who were diagnosed with severe influenza A with primary viral pneumonia in our hospital from December 2017 to March 2018. The cases were divided into three groups: the peramivir group, the peramivir combined with ribonucleic acid group, and the peramivir combined with thymopetidum group. Results: The duration of viral nucleic acid positivity in the peramivir group, the peramivir combined with ribonucleic acid group, and the peramivir combined with thymopetidum group was 6.13 ± 2.06, 6.53 ± 2.72, and 6.10 ± 1.37 days, respectively. The remission time of the clinical symptoms of the peramivir group, the peramivir combined with ribonucleic acid group, and the peramivir combined with thymopetidum group was 8.06 ± 2.73, 7.94 ± 2.89, and 7.67 ± 1.58 days, respectively. Comparisons between the peramivir group and the peramivir combined with ribonucleic acid group or the peramivir combined with thymopetidum group revealed no significant differences in the duration of virus nucleic acid positivity, remission time of clinical symptoms, time to fever alleviation, and time to cough alleviation. Conclusions: There is no observed benefit in the addition of ribonucleic acid or thymopetidum when peramivir sodium chloride injection is used in the treatment of severe influenza A with primary viral pneumonia. This trial is registered with ChiCTR1800019417.
Antiviral Agents/therapeutic use , Cyclopentanes/therapeutic use , Guanidines/therapeutic use , Immunologic Factors/therapeutic use , Influenza, Human/drug therapy , Pneumonia, Viral/drug therapy , RNA/therapeutic use , Acids, Carbocyclic , Adult , Aged , Drug Therapy, Combination , Female , Humans , Influenza A virus , Influenza, Human/complications , Male , Middle Aged , Pneumonia, Viral/virology , Retrospective Studies , Young Adult
The Earth's lowermost mantle large low velocity provinces are accompanied by small-scale ultralow velocity zones in localized regions on the core-mantle boundary. Large low velocity provinces are hypothesized to be caused by large-scale compositional heterogeneity (i.e., thermochemical piles). The origin of ultralow velocity zones, however, remains elusive. Here we perform three-dimensional geodynamical calculations to show that the current locations and shapes of ultralow velocity zones are related to their cause. We find that the hottest lowermost mantle regions are commonly located well within the interiors of thermochemical piles. In contrast, accumulations of ultradense compositionally distinct material occur as discontinuous patches along the margins of thermochemical piles and have asymmetrical cross-sectional shape. Furthermore, the lateral morphology of these patches provides insight into mantle flow directions and long-term stability. The global distribution and large variations of morphology of ultralow velocity zones validate a compositionally distinct origin for most ultralow velocity zones.Ultralow velocity zones are detected on the core-mantle boundary, but their origin is enigmatic. Here, the authors find that the global distribution and large variations of morphology of ultralow velocity zones are consistent with most having a compositionally-distinct origin.
Two new (1-2) and two known C21 steroids (3-4) were isolated from the roots of Cynanchum atratum. Their structures were elucidated by detailed 1D and 2D spectroscopic. The MTT assay showed that compounds 1-4 displayed obvious cytotoxic activities against HepG2 cells with IC50 values ranging from 10.19µM to 76.12µM. Compounds 1-3 also exhibited cytotoxic effects in A549 cells with IC50 values of 30.87-95.39µM. Compound 3 showed the antiproliferative activity via G0/G1 cell cycle arrest and proapoptosis in HepG2 cells by Flowcytometry analysis. Western blotting analysis revealed that compound 3 could induce HepG2 cell apoptosis via the mitochondrial pathway by downregulating Bcl-2 expression, upregulating Bax protein expression, and activating caspase-9 and caspase-3.
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Plant Roots/chemistry , Steroids/pharmacology , Vincetoxicum/chemistry , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , G1 Phase Cell Cycle Checkpoints/drug effects , Hep G2 Cells , Humans , Resting Phase, Cell Cycle/drug effects , Steroids/chemistry , Steroids/isolation & purification
Two new (1-2) and three known (3-5) C21 steroidal glycosides were isolated from Cynanchum stauntonii. Their structures were elucidated on the basis of 1D and 2D-NMR spectroscopic data as well as HRTOFMS analysis. The cytotoxicity of the compounds against A549, HepG2, and 4T1 cell lines were evaluated by MTT assay. Compound 4 exhibited good inhibitory activities with the IC50 values 26.82, 12.24, and 44.12 µM, respectively. Furthermore, compound 4 could induce G1 phase arrest, upregulate the expression levels of caspases-3, -9, and Bax, and downregulate the expression level of Bcl-2. These results indicated that compound 4 might be valuable to anticancer drug candidates.
Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Cynanchum/chemistry , Glycosides/chemistry , Glycosides/pharmacology , Steroids/chemistry , Animals , Antineoplastic Agents, Phytogenic/isolation & purification , Cell Line, Tumor , G1 Phase Cell Cycle Checkpoints/drug effects , Glycosides/isolation & purification , Hep G2 Cells , Humans , Rats
