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•The application of graphene-based interlayer materials in Lithium–sulfur batteries is summarized.•The various modification strategies of graphene-based interlayer materials are ...reviewed.•Challenges and future prospects of application of graphene-based interlayers in lithium-sulfur batteries are proposed.
Lithium–sulfur (LiS) batteries have been widely studied, and considered as one of the most promising energy storage systems, because of their superior theoretical energy density, non-toxicity, high abundance, and environmental friendliness. However, LiS batteries suffer from problems such as the electrical insulating characteristic of sulfur and unsatisfactorily long cycling life. As a superior type of carbon material, graphene have been intensively investigated as intermediate layers to overcome these problems because of its large surface area, good chemical stability, and excellent electrical conductivity. In this review, we summarize the recent application of graphene-based materials, including simple graphene and graphene-based nanocomposites, as modifying interlayers in LiS batteries. Furthermore, the strategies to enhance their electrochemical performance are summarized and discussed, for example, physical and chemical confinement. Finally, the limitation and challenges of graphene-based materials as interlayers for LiS batteries, as well as their prospects for future research, are proposed. We hope that this review will be helpful for scientists to design and fabricate high-performance LiS batteries based on graphene-based interlayers and boost their practical applications.
Airway remodelling is the major pathological feature of chronic obstructive pulmonary disease (COPD), and leads to poorly reversible airway obstruction. Current pharmacological interventions are ...ineffective in controlling airway remodelling. In the present study, we investigated the potential role of artesunate in preventing and treating airway remodelling and the underlying molecular mechanisms in vitro and in vivo.
A COPD rat model was established by cigarette smoke (CS) exposure. After 12 weeks of artesunate treatment, pathological changes in the lung tissues of COPD rats were examined by ELISA and histochemical and immunohistochemical staining. A lung functional experiment was also carried out to elucidate the effects of artesunate. Human bronchial smooth muscle (HBSM) cells were used to clarify the underlying molecular mechanisms.
Artesunate treatment inhibited CS-induced airway inflammation and oxidative stress in a dose-dependent manner and significantly reduced airway remodelling by inhibiting α-smooth muscle actin (α-SMA) and cyclin D1 expression. PPAR-γ was upregulated and TGF-β1/Smad2/3 signalling was inactivated by artesunate treatment in vivo and in vitro. Furthermore, PPAR-γ knockdown by siRNA transfection abolished artesunate-mediated inhibition of HBSM cell proliferation by activiting the TGF-β1/Smad2/3 signalling pathway and downregulating the expression of α-SMA and cyclin D1 in HBSM cells.
These findings suggest that artesunate could be used to treat airway remodelling by regulating PPAR-γ/TGF-β1/Smad signalling in the context of COPD.
Zn-ion batteries (ZIBs) have gained great attention as promising next-generation power sources, because of their low cost, enviable safety and high theoretical capacity. Recently, massive researches ...have been devoted to vanadium-based materials as cathodes in ZIBs, owing to their multiple valence states, competitive gravimetric energy density, but the capacity degradation, sluggish kinetics, low operating voltage hinder further optimization of their performance in ZIBs. This review summarizes recent progress to increase the interlayer spacing, structural stability, and the diffusion ability of the guest Zn ions, including the insertion of different ions, introduction of defects, design of diverse morphologies, the combination of other materials. We also focus on approaches to promoting the valuable performance of vanadium-based cathodes, along with the related ongoing scientific challenges and limitations. Finally, the future perspectives and research directions of vanadium-based aqueous ZIBs are provided.
In this mini-review, the approaches to promote the valuable performance of vanadium-based cathodes were summarized. The reaction mechanism of vanadium-based aqueous Zn-ion batteries were elucidated in detail, as well as the future perspectives and research directions. Display omitted
Introduction
Many concerns still exist regarding the safety of hydroxychloroquine (HCQ) in the treatment of Coronavirus Disease 2019 (COVID-19).
Objectives
The purpose of this study was to evaluate ...the safety of HCQ in the treatment of COVID-19 and other diseases by performing a systematic review and meta-analysis.
Methods
Randomized controlled trials (RCTs) reporting the safety of HCQ in PubMed, Embase, and Cochrane Library were retrieved starting from the establishment of the database till June 5, 2020. Literature screening, data extraction, and assessment of risk bias were performed independently by two reviewers.
Results
We identified 53 eligible studies involving 5496 patients. The meta-analysis indicated that the risk of adverse effects (AEs) in the HCQ group was significantly increased compared with that in the control group (RD 0.05, 95%CI, 0.02 to 0.07,
P
= 0.0002), and the difference was also statistically significant in the COVID-19 subgroup (RD 0.15, 95%CI, 0.07 to 0.23,
P
= 0.0002) as well as in the subgroup for other diseases (RD 0.03, 95%CI, 0.01 to 0.04,
P
= 0.003).
Conclusions
HCQ is associated with a high total risk of AEs compared with the placebo or no intervention in the overall population. Given the small number of COVID-19 participants included, we should be cautious regarding the conclusion stating that HCQ is linked with an increase incidence of AEs in patients with COVID-19, which we hope to confirm in the future through well-designed and larger sample size studies.
Increasing active metal sites is a valid approach to improve the catalytic activity of the catalyst. Co3+ is the main active metal site of Co-based catalysts. In this research work, through the ...partial transformation of CoFePBA (CFP) via low-temperature heat treatment, the effective control of the Co3+/Co2+ ratio has been achieved. The partial transformation strategy of low-temperature heat treatment can not only maintain the original framework structure of CFP, but also increase more active sites. The characterization results show that the CFP-200 sample obtained via heat treatment at 200 °C for 2 h under N2 atmosphere has the highest Co3+/Co2+ ratio. As an oxygen evolution reaction electrocatalyst, CFP-200 shows the best electrocatalytic activity among all samples. In 1.0 mol/L KOH electrolyte, the overpotential is 312 mV at a current density of 10 mA/cm2. Therefore, low-temperature heat treatment provides an effective method for preparing low-cost and high-efficiency electrocatalysts.
Appropriate low-temperature heat treatment of CoFePBA induces Co3+ enrichment and provides a large number of active sites for the electrocatalytic OER process. Furthermore, the sample inherits the porous framework of CoFePBA, which ensures the mass transfer inside the structure during the electrocatalytic OER process. Display omitted
Iron oxides are potential electrode materials for lithium-ion batteries because of their high theoretical capacities, low cost, rich resources, and their non-polluting properties. However, iron ...oxides demonstrate large volume expansion during the lithium intercalation process, resulting in the electrode material being crushed, which always results in poor cycle performance. In this paper, to solve the above problem, iron oxide/carbon nanocomposites with a hollow core–shell structure were designed. Firstly, an Fe2O3@polydopamine nanocomposite was prepared using an Fe2O3 nanocube and dopamine hydrochloride as precursors. Secondly, an Fe3O4@N-doped C composite was obtained by means of further carbonization treatment. Finally, Fe3O4@void@N-Doped C-x composites with core–shell structures with different void sizes were obtained by means of Fe3O4 etching. The effect of the etching time on the void size was studied. The electrochemical properties of the composites when used as lithium-ion battery materials were studied in more detail. The results showed that the sample that was obtained via etching for 5 h using 2 mol L−1 HCl solution at 30 °C demonstrated better electrochemical performance. The discharge capacity of the Fe3O4@void@N-Doped C-5 was able to reach up to 1222 mA g h−1 under 200 mA g−1 after 100 cycles.
Background:
Vancomycin remains the cornerstone antibiotic for the treatment of infective endocarditis (IE). Vancomycin has been associated with significant nephrotoxicity. However, vancomycin ...associated acute kidney injury (AKI) has not been evaluated in patients with IE. We conducted this large retrospective cohort study to reveal the incidence, risk factors, and prognosis of vancomycin-associated acute kidney injury (VA-AKI) in patients with IE.
Methods:
Adult patients diagnosed with IE and receiving vancomycin were included. The primary outcome was VA-AKI.
Results:
In total, 435 of the 600 patients were enrolled. Of these, 73.6% were male, and the median age was 52 years. The incidence of VA-AKI was 17.01% (74). Only 37.2% (162) of the patients received therapeutic monitoring of vancomycin, and 30 (18.5%) patients had reached the target vancomycin trough concentration. Multiple logistic regression analysis revealed that body mass index odds ratio (OR) 1.088, 95% CI 1.004, 1.179, duration of vancomycin therapy (OR 1.030, 95% CI 1.003, 1.058), preexisting chronic kidney disease (OR 2.291, 95% CI 1.018, 5.516), admission to the intensive care unit (OR 2.291, 95% CI 1.289, 3.963) and concomitant radiocontrast agents (OR 2.085, 95% CI 1.093, 3.978) were independent risk factors for VA-AKI. Vancomycin variety (Lai Kexin vs. Wen Kexin, OR 0.498, 95% CI 0.281, 0.885) were determined to be an independent protective factor for VI-AKI. Receiver operator characteristic curve analysis revealed that duration of therapy longer than 10.75 days was associated with a significantly increased risk of VA-AKI (HR 1.927). Kidney function was fully or partially recovered in 73.0% (54) of patients with VA-AKI.
Conclusion:
The incidence of VA-AKI in patients with IE was slightly higher than in general adult patients. Concomitant contrast agents were the most alarmingly nephrotoxic in patients with IE, adding a 2-fold risk of VA-AKI. In patients with IE, a course of vancomycin therapy longer than 10.75 days was associated with a significantly increased risk of AKI. Thus, closer monitoring of kidney function and vancomycin trough concentrations was recommended in patients with concurrent contrast or courses of vancomycin longer than 10.75 days.
A binder plays an important role in lithium-ion batteries (LIBs), especially for the electrode materials which have large volume expansion during charge and discharge. In this work, we designed a ...cross-linked polymeric binder with an esterification reaction of Sodium Carboxymethyl Cellulose (CMC) and Fumaric Acid (FA), and successfully used it in an Sb2O3 anode for LIBs. Compared with conventional binder polyvinylidene fluoride (PVDF) and CMC, the new cross-linked binder improves the electrochemical stability of the Sb2O3 anode. Specifically, with CMC-FA binder, the battery could deliver ~611.4 mAh g−1 after 200 cycles under the current density of 0.2 A g−1, while with PVDF or CMC binder, the battery degraded to 265.1 and 322.3 mAh g−1, respectively. The improved cycling performance is mainly due to that the cross-linked CMC-FA network could not only efficiently improve the contact between Sb2O3 and conductive agent, but can also buffer the large volume charge of the electrode during repeated charge/discharge cycles.
As a high-efficiency energy storage and conversion device, lithium-ion batteries have high energy density, and have received widespread attention due to their good cycle performance and high ...reliability. However, currently commercial lithium batteries usually use organic solutions containing various lithium salts as liquid electrolytes. In practical applications, liquid electrolytes have many shortcomings and shortcomings, such as poor chemical stability, flammability, and explosion. Therefore, the liquid electrolyte has a great safety hazard. The use of solid electrolyte ensures the safety of lithium-ion batteries, and has the advantages of high energy density, good cycle performance, long life, and wide electrochemical window, making the battery safer and more durable, with higher energy density and simple battery Structural design. Solid electrolytes mainly include inorganic solid electrolytes and organic polymer solid electrolytes. Although both inorganic solid electrolytes and polymer solid electrolytes have their own advantages, as far as the existing research work is concerned, whether it is an inorganic system or a polymer system, a single-system solid electrolyte can never achieve the full performance of an ideal solid electrolyte. The composite solid electrolyte composed of active or passive inorganic filler and polymer matrix is considered as a promising candidate electrolyte for all-solid-state lithium batteries. Among many polymer systems, PEO-based is considered to be the most ideal polymer substrate. In this review article, we first introduced the structure, properties, and preparation methods of PEO-based polymer electrolytes. Furthermore, the researches related to the modification of PEO-based polymer solid electrolytes in recent years are summarized. The contribution of polymer structural modification and the introduction of additives to the ionic conductivity, electrochemical stability and mechanical properties of PEO-based solid electrolytes is described. Examples of different composite solid electrolyte design concepts were extensively discussed, such as inorganic inert nanoparticles/PEO, oxide/PEO, and sulfide/PEO. Finally, the future development direction of composite solid electrolytes was prospected.
Four Si3N4 crystal structures were predicted using an ab initio evolutionary methodology. The mechanical and dynamic stabilities were confirmed by the density functional theory assuming zero-pressure ...conditions. Energetic stability calculations indicated that the structures are metastable phases at ambient pressure, but their formation is more favorable at high pressures. At zero pressure, the densities of the hp-Si3N4, cp-Si3N4, oc-Si3N4, and ti-Si3N4 phases were 3.21, 3.28, 3.70, and 3.24 g/cm3, respectively. The calculated band structures and densities of states indicated that they have semiconductive properties, with gaps ranging from 0.754 to 3.968 eV. Mechanical property calculations revealed that the hardness of the Si3N4 compounds ranged between 11.2 and 23.3 GPa, which were higher than the corresponding values for the synthesized Si3N4 phases. These four Si3N4 structures are potentially valuable candidates for the synthesis of Si3N4 compounds.
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