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Aberrant activation of cardiac fibroblasts is the main cause and character of cardiac fibrosis, and inhibition of cardiac fibrosis becomes a promising treatment for cardiac diseases. Platelet-activating factor (PAF) and Hippo pathway is recently recognized as key signaling mechanisms in cardiovascular diseases. In this study we explored the potential roles of PAF and Hippo signaling pathway in cardiac fibrosis. Myocardial infarction (MI) was induced in mice by left anterior descending artery ligation. After 28 days, the mice were sacrificed, and the hearts were collected for analyses. We showed that PAF receptor (PAFR) and yes-associated protein 1 (YAP1, a key effector in the Hippo pathway) were significantly increased in the heart of MI mice. Increased expression of PAFR and YAP1 was also observed in angiotensin II (Ang II)-treated mouse cardiac fibroblasts. In mouse cardiac fibroblasts, forced expression of YAP1 increased cell viability, resulted in collagen deposition and promoted fibroblast-myofibroblast transition. We showed that PAF induced fibrogenesis through activation of YAP1 and promoted its nuclear translocation via interacting with PAFR, while YAP1 promoted the expression of PAFR by binding to and activating transcription factor TEAD1. More importantly, silencing PAFR or YAP1 by shRNA, or using transgenic mice to induce the conditional deletion of YAP1 in cardiac fibroblasts, impeded cardiac fibrosis and improved cardiac function in MI mice. Taken together, this study elucidates the role and mechanisms of PAFR/YAP1 positive feedback loop in cardiac fibrosis, suggesting a potential role of this pathway as novel therapeutic targets in cardiac fibrosis.

The cellular structured titanium alloys have attracted significant attention for implants because of their lower Youngʼs modulus, which is comparable to human bone and has the capability of providing space for bone tissue in-growth. However, there is a gap in the knowledge in regard to the relationship between the pore characteristics and the electrochemical performance of open-cellular structured titanium alloys. In this study, we elucidate the influence of pore characteristics on the electrochemical performance of open-cellular structured Ti-6Al-4V alloys produced by electron beam melting (EBM). Intriguingly, the passive film formed on cellular structured Ti-6Al-4V alloy with a larger pore size was more stable and protective, and the corrosion performance was superior compared to the samples with a smaller pore size in phosphate buffered saline (PBS), mainly because of relatively smaller exposed surface area and unlimited flow of electrolyte. However, in acidic PBS containing fluoride ions, the pore characteristics did not play an important role in the corrosion resistance. It was considered that the protective film breaks down such that the corrosion performance of cellular structured alloys was comparable to each other in this harsh environment.

Porous titanium and its alloys have been considered as promising implants owing to their low elastic modulus and capability to provide channels for bone growth. Currently, additive manufacturing (3D printing) techniques have been successfully applied to produce porous titanium alloys owing to the advantages of controllable and precise fabrication. Considering the safety aspect, an understanding of corrosion in porous titanium alloys and the corresponding mechanisms is important for their long-term application in the human body. In this paper, the recent progress in improving the corrosion properties of porous titanium alloys fabricated via 3D printing techniques is reviewed. The effects of pore type, porosity, electrolyte, and modification of the material on the corrosion properties of porous titanium alloys are introduced and discussed. In addition, the limitations of traditional methods for measuring the corrosion performance of porous titanium alloys were analysed. Perspectives for evaluating and improving the corrosion performance of porous titanium alloys using new methods are provided.

Given the harsh reality faced by the global effort to contain coronavirus disease 2019 (COVID-19) and the virtual impossibility of its worldwide eradication in the foreseeable future, global human coexistence with fast mutating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may have to occur, for the time being, irrespective of the wishes and aspirations of our people. Therefore, for China, the risk associated with small to medium scale outbreaks induced by imported cases and the corresponding need to continuously and promptly suppress domestic infections would persist for a certain period of time. However, such reality would not imply that we can deviate from our existing effective COVID-Zero strategy on entry-exit quarantine measures and community non-pharmaceutical interventions (NPIs) containment measures and embrace certain “open-up” strategies without reservation, resting solely on the hypothesis of the success of herd immunity induced by vaccination advocated by certain western countries. In this article, we found that even in a highly underestimated outbreak scenario under the most optimistic assumptions, once China adopts the control and prevention strategies of some typical western countries, the number of the daily new confirmed cases in China would likely rise up to hundreds of thousands of cases, and among which >10,000 cases would present with severe symptoms. Particularly, the number of standing severe cases would exceed the peak number nationwide in early 2020 within 1–2 days, which would have a devastating impact on the medical system of China and cause a great disaster within the nation.

Tremendous energy consumption is required for traditional artificial N2 fixation, leading to additional environmental pollution. Recently, new Li-N2 batteries have inextricably integrated energy storage with N2 fixation. In this work, graphene is introduced into Li-N2 batteries and enhances the cycling stability. However, the instability and hygroscopicity of the discharge product Li3 N lead to a rechargeable but irreversible system. Moreover, strong nonpolar N≡N covalent triple bonds with high ionization energies also cause low efficiency and irreversibility of Li-N2 batteries. In contrast, the modification with in situ generated Li3 N and LiOH restrained the loss and volume change of Li metal anodes during stripping and plating, thereby promoting the rechargeability of the Li-N2 batteries. The mechanistic study here will assist in the design of more stable Li-N2 batteries and create more versatile methods for N2 fixation.

Objective Extent of resection of glioblastoma is an important predictor for overall survival, and 5-aminolevulinic acid fluorescence-guided surgery can improve outcomes. However, the technique requires the installation of a blue light module on operative microscopes and may be cost prohibitive. A novel and economical blue light-emitting headlamp was designed, and its clinical utility was explored. Methods A remote-controlled dual light emitting diode headlamp system was constructed with 1 diode emitting white light and the other blue. Spectrographic analysis of the blue light emitted from a commercial operative microscope and the headlamp was performed. A comparative evaluation of the 2 illumination systems was conducted for 3 patients who underwent craniotomy for glioblastoma resection. Histologic examination of the fluorescing tissue detected by the headlamp was performed, and the extent of resection was assessed by postoperative day 1 magnetic resonance imaging. Results Spectrography of blue light emitted from the headlamp system was wavelength specific with a single emission peak at 416 nm and a linewidth of 35 nm. In contrast, blue light from the microscope (peak: 426 nm) had a wider linewidth of 54 nm and was not wavelength specific with additional infrared radiation detected. Gross or near-total resection of contrast-enhancing glioblastoma was performed for all 3 patients. Intraoperatively, comparable tumor fluorescence was observed under microscope and headlamp blue light illumination. Histologic examination of tissue fluorescing under headlamp blue light confirmed the presence of glioblastoma. Conclusions This novel proof-of-concept blue light−emitting headlamp device may offer an opportunity for institutions with limited resources to implement 5-aminolevulinic acid fluorescence-guided glioblastoma resections.

A compact G e 11.5 A s 24 S e 64.5 chalcogenide microring resonator is fabricated with an intrinsic quality factor of 3.0 × 10 5 in the telecom band. By taking advantage of the strong nonlinearity and cavity enhancement, highly efficient wavelength conversion via four-wave mixing is demonstrated using a microring resonator. Conversion efficiency of − 33.7 d B is obtained by using an ultra-low pump power of 63.8 µW. This work shows that G e 11.5 A s 24 S e 64.5 chalcogenide microring devices are promising for quantum photonics.

BackgroundsFew studies examine the transmission dynamics and heterogeneity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in rural areas and clarify rural–urban differences. Moreover, the effectiveness of non-pharmaceutical interventions (NPIs) relative to that of vaccination in rural areas is uncertain.MethodsWe addressed this knowledge gap using an improved statistical stochastic method based on the Galton–Watson branching process considering both symptomatic and asymptomatic cases. Data were collected from the epidemiological records of 1136 SARS-2-CoV infections after the rural outbreak in Hebei, China, between 2 January and 20 February 2021.ResultsThe estimated average reproductive number R and dispersion parameter k (k R = 0.81, k = 0.27) showed that in the vaccination scenario (80% efficacy and 55% coverage), the cumulative secondary infections will be reduced by more than half; however, NPIs are more effective than vaccinating 65% of the population. The presence of asymptomatic infections might affect the estimation of R but showed no significant effect on estimating transmission heterogeneity.ConclusionThe government should pay equal value to SARS-CoV-2 transmission in rural and urban areas and conduct specific prevention and control measures in rural areas. Older adults and children should receive particular attention in such policies, and community contact should be minimized. Moreover, the government must consider a country’s economy and governance when conducting vaccination and NPIs.

Introduction: The coronavirus disease 2019 (COVID-19) pandemic has been going on for over a year and has reemerged in several regions Therefore, understanding the covertness of COVID-19 is critical to more precisely estimating the pandemic size, especially the population of hidden carriers (those with very mild or no symptoms) Methods: A stochastic dynamic model was proposed to capture the transmission mechanism of COVID-19 and to depict the covertness of COVID-19 The proposed model captured unique features of COVID-19, changes in the diagnosis criteria, and escalating containment measures Results: The model estimated that, for the epidemic in Wuhan, 79 8% (76 7%–82 7%) of the spread was caused by hidden carriers The overall lab-confirmation rate in Wuhan up until March 8, 2020 was 0 17 (0 15–0 19) The diagnostic rate among patients with significant symptoms went up to 0 82 on March 8, 2020 from 0 43 on January 1, 2020 with escalating containment measures and nationwide medical supports The probability of resurgence could be as high as 0 72 if containment measures were lifted after zero new reported (lab-confirmed or clinically confirmed) cases in a consecutive period of 14 days This probability went down to 0 18 and 0 01 for measures lifted after 30 and 60 days, respectively Discussion: Consistent with the cases detected in Wuhan in mid-May, 2020, this study suggests that much of the COVID-19 pandemic is underreported and highly covert, which suggests that strict measures must be enforced continuously to contain the spread of the pandemic

To explore the clinical effect of whole course nursing intervention on critically ill patients and control of complications is the main objective. The clinical data of 86 patients in intensive care unit of our hospital from January 2019 to June 2020 were selected and divided into two groups according to different nursing schemes, 43 cases in the control group and 43 cases in the study group. The control group was given routine nursing, while the study group was given comprehensive nursing, mainly including risk assessment, psychological nursing and life nursing. The psychological status, sleep quality, inflammatory factors, complications and nursing satisfaction of patients after nursing intervention were evaluated. There was no significant difference in self-rating anxiety scale, self-rating depression scale score and sleep quality score between the two groups before treatment (p>0.05). After nursing intervention, self-rating anxiety scale, self-rating depression scale and sleep quality scores of the two groups were significantly lower than those of the control group, and the difference was statistically significant (p 0.05), after nursing, the serum procalcitonin and interleukin-6 levels of the study group were significantly lower than those of the control group (p

We demonstrate ultra-low power wavelength conversion via four-wave mixing in a Ge11 . 5As24Se64 . 5 microring resonator with 20-µm radius. The results show conversion efficiency of -33.7 dB with only 63.8 µW pump power.

In this work, TiNi samples were prepared by Selective Laser Melting (SLM) technology, and the influence of microstructure, fluoride ion, and pH value on corrosion behavior in a saline environment was investigated and compared with TiNi alloy fabricated by traditional forging technology. The results indicated that the corrosion resistance of the SLM sample was slightly superior to that of the wrought sample in a saline environment due to the uniform and dense oxide film formed on the SLM sample surface. However, in acidic Artificial Saliva Solution (ASS) containing fluoride ions, the corrosion current density of the SLM sample increased from 9.85 × 10−2 to 13.9 μA/cm2 because of the presence of F−. Fluorine ions disrupted the passive film on the surface, and the Ti-F compound formed in the film, which deteriorated the corrosion resistance of the SLM sample. The increase in fluoride concentration and the decrease in pH value could accelerate the corrosion of the SLM sample.

The current outbreak of coronavirus disease 2019 (COVID-19) has quickly spread across countries and become a global crisis. Understanding the transmission mechanism and effects of interventions is critical to the prevention and control of the COVID-19 pandemic. A recent study by Hao et al (2020) provided an interesting perspective on the transmission dynamics of COVID-19 in Wuhan and inferred that 87% of the infections before 8 March 2020 were not laboratory-confirmed. However we believe that there are a few major issues due to the vagueness in the definitions of compartments and inconsistence in the settings of parameters. In this paper, we clarify the definitions of the model compartments and raise questions in regard to the underlying homogenous assumption within compartments and settings of the parameters in the dynamic model by Hao et al (2020), and furthermore offer a modified model to resolve these potential limitations. Compared with the model in Hao et al (2020), the active virus carriers were predicted to persist for a longer period in our model which is well consistent with the active virus carriers detected in Wuhan in mid-May. Our model suggests that control measures cannot be easily lifted while continuous efforts are needed to contain the spread of the pandemic; a universal PT-PCR screening is essential to detect hidden cases before lifting control measure. In addition, we also provide a possible solution to solve the problem of heterogeneity transmission rate in disease courses.

The current outbreak of coronavirus disease 2019 (COVID-19) has quickly spread across countries and become a global crisis. Understanding the transmission mechanism and effects of interventions is critical to the prevention and control of the COVID-19 pandemic. A recent study by Hao et al (2020) provided an interesting perspective on the transmission dynamics of COVID-19 in Wuhan and inferred that 87% of the infections before 8 March 2020 were not laboratory-confirmed. However we believe that there are a few major issues due to the vagueness in the definitions of compartments and inconsistence in the settings of parameters. In this paper, we clarify the definitions of the model compartments and raise questions in regard to the underlying homogenous assumption within compartments and settings of the parameters in the dynamic model by Hao et al (2020), and furthermore offer a modified model to resolve these potential limitations. Compared with the model in Hao et al (2020), the active virus carriers were predicted to persist for a longer period in our model which is well consistent with the active virus carriers detected in Wuhan in mid-May. Our model suggests that control measures cannot be easily lifted while continuous efforts are needed to contain the spread of the pandemic; a universal PT-PCR screening is essential to detect hidden cases before lifting control measure. In addition, we also provide a possible solution to solve the problem of heterogeneity transmission rate in disease courses.

Lithium-oxygen (Li-O 2 ) batteries are considered as one of the most promising energy storage systems due to their ultra-high theoretical capacity. However, most currently studied Li-O 2 batteries are based on the reduction/oxidation of Li 2 O 2 and involve highly reactive superoxide and peroxide species that would cause serious degradation of cathodes, especially carbon-based materials. It is of great importance to explore lithium-oxygen reactions and find new Li-O 2 chemistry which can restrict or even avoid the negative influence of superoxide/peroxide species. Here, inspired by enzyme-catalyzed oxygen reduction/oxidation reactions, we introduce a copper(I) complex 3N-Cu I (3N=1,4,7-trimethyl-1,4,7-triazacyclononane) to Li-O 2 batteries and successfully modulate the reaction pathway to a moderate one on reversible cleavage/formation of O-O bonds. This work demonstrates that the reaction pathways of Li-O 2 batteries could be modulated by introducing an appropriate soluble catalyst, which is another powerful choice to construct better Li-O 2 batteries.

We demonstrate compact Ge11 . 5As24Se64 . 5 chalcogenide microring resonators with a radius of 20 µm and achieve a high intrinsic optical quality factor of 3.8×105 in telecom band, which corresponds to a low propagation loss around 1.4 dB/cm.

The microstructure, composition, semiconductive properties and electrochemical performance of passive film formed on the surface of Ti-6Al-4 V alloy produced by electron beam melting (Abbreviated as ET) were compared with conventional wrought counterpart (WT) in phosphate buffered saline at 37 °C. The results demonstrated a thinner and more compact passive film formed on ET, which was attributed to the small grain size and high density of grain boundaries in ET, these active sites increased the growth rate at the initial stage in the manner of 3D progressive nucleation mechanism of passive film, leading to superior corrosion resistance than WT.

Highly active and durable electrocatalysts are desired to promote oxygen reduction reactions (ORR) for Zn-air batteries. Here we report a promising catalyst of Pd nanoparticles supported on boron carbide (Pd/B4C) through a facile hydrothermal route. The Pd/B4C electrode not only shows the same onset potential of 0.96 V vs. RHE as the Pt/C electrode, but also an obviously larger limiting current density. More importantly, compared with noble metal electrodes, Pd/B4C shows higher power density (187 mW cm-2) and much more durable cycle life (up to 1333 h) in Zn-air batteries. To gain insight into the enhanced ORR activity by B4C support, first-principles computations reveal the synergistic effect between B4C and Pd; B4C could significantly promote O2 adsorption and splitting on Pd/B4C composites, while Pd particles on B4C have a major effect on the transformation of O* to OH-. The computations are consistent with the experimental characterizations. This work opens up a new avenue for seeking novel and durable electrocatalysts for Zn-air batteries with B4C substrates, which are chemically and electrochemically stable in hash alkaline electrolytes during operation.

Rechargeable Li-O2 batteries have aroused much attention for their high energy density as a promising battery technology; however, the performance of the batteries is still unsatisfactory. Lithium anodes, as one of the most important part of Li-O2 batteries, play a vital role in improving the cycle life of the batteries. Now, a very simple method is introduced to produce a protective film on lithium surface via chemical reactions between lithium metals and 1,4-dioxacyclohexane. The film is mainly composed of ethylene oxide monomers and endows Li-O2 batteries with enhanced cycling stability. The film could effectually reduce the morphology changes and suppress the parasitic reactions of lithium anodes. This simple approach provides a new strategy to protect lithium anodes in Li-O2 batteries.

Rechargeable Li-O2 batteries have aroused much attention for their high energy density. However, the poor rechargeability and low efficiency hinder their practical applications. To solve these issues, free-standing carbon films combined with high-activity NiFe2O4 catalysts are prepared by electrospinning method, and directly used as air cathodes for Li-O2 batteries. The obtained films have 3D networks formed by stacking and interlacing massive nanofibers with uniformly dispersed NiFe2O4 nanoparticles on them. The Li-O2 batteries with such binder-free air cathodes show low charging overpotential even comparable to precious metal cathodes, and can sustain excellent discharge/charge cyclic stability. The unique structure and binder-free superiority greatly facilitates the Li+ and O2 diffusion, accelerates the decomposition of Li2O2, and avoid the disturbance of polymer binders.

Rechargeable Li–CO2 batteries are promising energy storage systems for reducing fossil fuel consumption and mitigating the “greenhouse effect” due to the use of a reversible reaction between lithium and CO2. However, current Li–CO2 batteries still suffer from several unresolved problems such as high charge potential and low coulombic efficiency, and hence more efforts are required to optimize their electrochemical performance. In this work, a composite of sheet-like NiO dispersed on carbon nanotubes was prepared via a solvothermal method. The composite was employed as an efficient air cathode for Li–CO2 batteries, with very high coulombic efficiency (97.8%) and good cycling stability (40 cycles). This study provides new strategies to develop cheap and abundant catalysts to improve the performance of Li–CO2 batteries.

The objective of the study described here is to fundamentally elucidate the biological response of 3D printed Ti-6Al-4V alloy mesh structures that were surface modified to introduce titania nanotubes with an average pore size of ∼80 nm via an electrochemical anodization process from the perspective of enhancing bioactivity. The bioactivity of the mesh structures were analyzed through immersion test in simulated body fluid, which confirmed the nucleation and growth of fine globular nanoscale apatite on the nanoporous titania-modified (anodized) mesh structure surface, and agglomerated apatite with fine flakes of apatite crystals on as-fabricated mesh structure surface, that were rich in calcium and phosphorous. The cellular activity of bioactive anodized mesh structure was explored in terms of cell–material interactions involving adhesion, proliferation, synthesis of extracellular and intracellular proteins, differentiation, and mineralization. Cells adhered with a sheet-like morphology on as-fabricated mesh structure, whereas, on anodized mesh structure, numerous filopodia-like cellular extensions interacting with nanotube pores were observed. The formation of a bioactive nanoscale apatite, cell–nanotube interactions as imaged via electron microscopy, higher expression of proteins (actin, vinculin, fibronectin, and alkaline phosphatase (ALP)), and calcium content points toward the determining role of anodized mesh structure in modulating osteoblasts functions. The unique combination of nanoporous bioactive titania and interconnected porous architecture of anodized titanium alloy mesh structure provided a multimodal roughness surface ranging from nano to micro to macroscale, which helps in attaining strong primary and secondary fixation of the implant device along with the pathway for supply of nutrients and oxygen to cells and tissue.

The electrochemical corrosion behaviour of Ti-6Al–4V prepared by electron beam melting was investigated in phosphate buffered saline and compared with those of traditional wrought counterpart. Electrochemical results showed EBM-produced Ti-6Al–4V possesses slightly better corrosion resistance than the wrought Ti-6Al–4V, which is attributed to larger proportions of β phase and ultrafine-grained lamellar α/β phases in the microstructure of EBM-produced Ti-6Al–4V. The β phase enhances the resistance of charge transfer, thereby reducing the rate of metal dissolving reaction; while the α/β phases result in homogenous distribution of alloying elements in different phases thus restraining the galvanic effect between α and β phases.

Rechargeable Li-CO2 batteries represent a novel approach towards clean recycling and utilization of CO2. Nevertheless, there are still many obstacles to be overcome. Here we report the first introduction of an electrolyte redox mediator (LiBr) to rechargeable Li-CO2 batteries, and the electrochemical performances were significantly improved, especially cyclic stability and rate capability. The proposed mechanism is that LiBr is beneficial for the formation of desired morphology of discharge products; moreover, the electrochemically generated Br2 promotes the decomposition of Li2CO3 chemically during the charging process.

Ti-6Al-4V alloys with cellular structure fabricated by additive manufacturing are currently of significant interest because their modulus is comparable to bone and the cellular structure allows the cells to penetrate and exchange nutrients, promoting osseointegration. We describe here a unique simulation device that replaces the traditional steady electrochemistry approach, enabling in-situ study of variation of ion concentration and surface potential with pore depth for cellular structured Ti-6Al-4V alloys fabricated by electron beam melting (EBM) in phosphate buffered saline (PBS). This approach addresses the scientific gap on the electrochemical behavior of cellular structured titanium alloys. The study indicated that concentration of H+ and Cl− increased with the increase of pore depth, while the surface potential decreased. The exposed surface of inner cellular structure was not corroded but passivated after immersing in PBS at 37 °C for 14 days, which was independent of pore depth. Furthermore, X-ray photoelectron spectroscopy (XPS) and Mott-Schottky (M-S) studies suggested that a thinner passive film containing a greater donor density was formed on the surface of cellular structured Ti-6Al-4V alloy at the deepest pore depth. This is attributed to insufficient oxygen supply and Cl−adsorption on the surface inside the pores. Statement of Significance Porous titanium alloys are promising implants in biomedical applications. However, it is a challenge to accurately characterize the corrosion behavior of porous titanium alloys with complex pore structure using traditional electrochemical methods. In this study, we have adopted a special device to simulate the environment within the pore structure. The variation in ion concentration and surface potential of Ti-6Al-4V fabricated by EBM with pore depth was in-situ monitored. After immersing in PBS for 14 days, Ti-6Al-4V exhibited good corrosion properties and the samples with less than 60 mm pore depth were not corroded but passivated. Also, we analyzed the difference in corrosion property at different pore depth. This type of in-situ corrosion performance monitoring in EBM-produced Ti-6Al-4V has not been previously studied.

Tremendous energy consumption is required for traditional artificial N

Few studies have examined the transmission dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in rural areas and clarified rural–urban differences. Moreover, the effectiveness of non-pharmaceutical interventions (NPIs) relative to vaccination in rural areas is uncertain. We addressed this knowledge gap through using an improved statistical stochastic method based on the Galton–Watson branching process, considering both symptomatic and asymptomatic cases. Data included 1136 SARS-2-CoV infections of the rural outbreak in Hebei, China, and 135 infections of the urban outbreak in Tianjin, China. We reconstructed SARS-CoV-2 transmission chains and analyzed the effectiveness of vaccination and NPIs by simulation studies. The transmission of SARS-CoV-2 showed strong heterogeneity in urban and rural areas, with the dispersion parameters k = 0.14 and 0.35, respectively (k &lt, 1 indicating strong heterogeneity). Although age group and contact-type distributions significantly differed between urban and rural areas, the average reproductive number (R) and k did not. Further, simulation results based on pre-control parameters (R = 0.81, k = 0.27) showed that in the vaccination scenario (80% efficacy and 55% coverage), the cumulative secondary infections will be reduced by more than half, however, NPIs are more effective than vaccinating 65% of the population. These findings could inform government policies regarding vaccination and NPIs in rural and urban areas.

The variation of electrochemical corrosion behavior with pore depth in porous Ti6Al4V alloys produced by electron beam melting (EBM) was studied in situ by a unique simulation model in acidic solution containing fluoride (PBS-H-F). The results suggested that steady-state pitting occurred at shallow pore depth position, while the sample at deep pore depth position exhibited superior corrosion resistance. The degree of corrosion on the surface was decreased with the increase in pore depth, including susceptibility to pitting, a behavior attributed to the concentration gradient of fluoride ions inside the pores.

Large overpotential in oxygen reduction and evolution reactions is the intractable obstruction of Li-O2 batteries, causing inferior round-trip efficiency and diminished cycle life. Modulating the reaction mechanism of Li2O2 is of crucial importance for a high-performance Li-O2 battery. Herein, we report a composite of amorphous RuO2 nanoparticles decorated carbon nanotubes (A-RuO2@CNT) as an efficient catalyst for Li-O2 batteries. The amorphous catalyst contains abundant defects and vacancies as well as distorted atom arrangements, which provide sufficient active sites for reactions and enhance the affinity for LiO2 intermediates. As a result, the formation/decomposition mechanisms of Li2O2 are reasonably regulated. An amorphous film-like Li2O2 product forms and uniformly deposits on the surface of A-RuO2@CNT, thus achieving faster redox kinetics and smaller overpotential. When used in Li-O2 batteries, the amorphous catalyst affords remarkably decreased charge overpotential and enhanced cyclic stability, which is superior to its crystalline counterpart.

An environment friendly nonlinear chalcogenide glass fiber with a Ge-Sb-Se core and a Ge-Se cladding is fabricated for bright broadband mid-infrared (MIR) supercontinuum (SC) generation. The fabricated Ge-Sb-Se/Ge-Se fiber with a core diameter of 6 μm shows zero group velocity dispersion at ~4.2 μm and ~7.3 μm. By pumping the fiber with a length of 11 cm at 4.485 μm with 330 fs pulses, we achieve a SC covering the 2.2–12 μm spectral range and with an output average power of ~17 mW. This bright broadband SC source is promising for high-resolution MIR spectroscopy.

Rechargeable alkali metalâair batteries are considered as the most promising candidate for the power source of electric vehicles (EVs) due to their high energy density. However, the practical application of metalâair batteries is still challenging. In the past decade, many strategies have been purposed and explored, which promoted the development of metalâair batteries. The reaction mechanisms have been gradually clarified and catalysts have been rationally designed for air cathodes. In this review, we summarize the recent development of alkali metalâair batteries from four parts: metal anodes, electrolytes, air cathodes and reactant gases, wherein we highlight the important achievement in this filed. Finally problems and prospective are discussed towards the future development of alkali metalâair batteries. Keywords: Metalâair batteries, Alkali metal anodes, Electrolytes, Ionic liquids, Air cathodes