Unveiling the chemistry behind the electrolytic production of hydrogen peroxide by oxygenated carbon

Oxygenated carbon materials exhibit outstanding electrocatalytic performance in the production of hydrogen peroxide(H2O2)through a two-electron oxygen reduction reaction.The nature of the active functional group and underlying reaction mechanism,however,remain unclear.Here,a comprehensive workflow was established to identify the active sites from the numerous possible structures.The common hydroxyl group at the notched edge demonstrates a key role in the two-electron process.The local chemical environment weakens the binding of OOH intermediate to substrate while enhancing interaction with solution,thereby promoting the H_(2)O_(2)production.With increasing pH,the intramolecular hydrogen bond between OOH intermediate and hydroxyl decreases,facilitating OOH desorption.Furthermore,the rise in selectivity with increasing potential stems from the suppression of the four-electron process.The active site was further validated through experiments.Guided by theoretical understanding,optimal performance was achieved with high selectivity(>95%)and current density(2.06 mA/cm^(2))in experiment.

Morphological Evolution of Self-Assembled Sodium Dodecyl Sulfate/Dodecyltrimethylammonium Bromide@Epoxy-β-Cyclodextrin Supramolecular Aggregates Induced by Temperature

Bio-based cyclodextrins(CDs)are a common research object in supramolecular chemistry.The special cavity structure of CDs can form supramolecular self-assemblies such as vesicles and microcrystals through weak interaction with guest molecules.The different forms of supramolecular self-assemblies can be transformed into each other under certain conditions.The regulation of supramolecular self-assembly is not only helpful to understand the self-assembly principle,but also beneficial to its application.In the present study,the self-assembly behavior of epoxy-β-cyclodextrin(EP-β-CD)and mixed anionic and cationic surfactant system(sodium dodecyl sulfate/dodecyltrimethylammonium bromide,SDS/DTAB)in aqueous solution was studied.Morphological and particle size characterization found that the SDS/DTAB@EP-β-CD complex,as the basic building unit,self-assembled into worm-like micelles at lower temperatures and vesicles at higher temperatures.Nuclear magnetic resonance(NMR)and Fourier transform infrared spectroscopy(FT-IR)analysis revealed that the driving force for the formation of vesicles and worm-like micelles was the hydrogen bonds between EP-β-CD molecules,while water molecules played an important role in promoting vesicle formation between SDS/DTAB@EP-β-CD units.Herein,the mechanism of the morphologic transformation of SDS/DTAB@EP-β-CD supramolecular aggregates induced by temperature was elucidated by exploring the self-assembly process,which may provide an excellent basis for the development of delivery carriers.

Recent Progress on Carbonaceous Material Engineering for Electrochemical Hydrogen Peroxide Generation

Electrochemical synthesis of hydrogen peroxide(H2 O2)provides a clean and safe technology for large-scale H2 O2 production.The core of this project is the development of highly active and highly selective catalysts.Recent studies demonstrate that carbonaceous materials are favorable catalysts because of their low-cost and tunable surface structures.This brief review first summarizes the strategies of carbonaceous material engineering for selective two-electron O2 reduction reaction and discusses potential mechanisms.In addition,several device designs using carbonaceous materials as catalysts for H2 O2 production are introduced.Finally,research directions are proposed for practical application and performance improvement.

1979~2020年北极和青藏高原臭氧低值区的动力输送特征比较

基于ERA5月平均再分析资料,利用Lorenz环流分解方法从定常和瞬变以及基流和涡旋的角度对比了北极与青藏高原臭氧低值区的动力输送特征。结果表明:动力总输送在两地上平流层作用最强,均使其臭氧浓度降低,且定常输送均强于瞬变输送,纬向与经向输送的作用均大致相反。然而,动力输送在北极地区的作用强度远大于青藏高原地区。北极地区纬向输送使得平流层中上层臭氧浓度降低,平流层下层臭氧浓度升高,经向输送的作用与之相反且强度明显偏弱,二者均主要作用于上平流层。青藏高原地区纬向和经向输送除在上平流层均使得臭氧浓度降低外,二者作用大致相反且强度相当,输送大值区在垂直方向上存在双中心结构,分别位于上平流层与上对流层—下平流层(Upper Troposphere–Lower Stratosphere,简称UTLS)区。两地区纬向和经向输送的差异均主要由定常涡旋输送所造成。青藏高原地区定常与瞬变输送的强度差异没有北极地区大。此外,两地定常和瞬变输送中涡旋对臭氧纬向平均的输送均起到主要作用,体现出涡旋输送在两地臭氧浓度变化的动力输送过程中发挥着至关重要的作用。

Double cores of the Ozone Low in the vertical direction over the Asian continent in satellite data sets

Using four satellite data sets(TOMS/SBUV, OMI, MLS, and HALOE), we analyze the seasonal variations of the total column ozone(TCO) and its zonal deviation(TCO*), and reveal the vertical structure of the Ozone Low(OV) over the Asian continent. Our principal findings are:(1) The TCO over the Asian continent reaches its maximum in the spring and its minimum in the autumn. The Ozone Low exists from May to September.(2) The Ozone Low has two negative cores, located in the lower and the upper stratosphere. The lower core is near 30 hPa in the winter and 70 hPa in the other seasons. The upper core varies from 10 hPa to 1 hPa among the four seasons.(3)The position of the Ozone Low in the lower and the upper stratosphere over the Asian continent shows seasonal variability.

Changes in target ability of nanoparticles due to protein corona composition and disease state

Many studies have shown the influence of protein corona(PC)on the active targeting capability of ligand-modified nanoparticles;however,the influence of clinical status on PC composition and targeting capacity is rarely discussed.In this study,when transferrinmodified PEGylated polystyrene nanoparticles(Tf-PNs)is intravenously injected into mice with non-small cell lung cancer(NSCLC)comorbid with type 2 diabetes mellitus(T2DM),more Tf-PNs accumulated in the tumor tissue than in those of NSCLC model mice.This indicated that PC derived fromdifferent states of disease changed the active targeting ability of Tf-PNs.To explain the occurrence of this phenomenon,our analysis of PC from different disease states revealed that Tf(transferrin)modification had no significant effect on the formation of PC,and that the PC from the NSCLC comorbid with T2DM model contained more proteins like fibrin and clusterin.This work demonstrates the impacts of comorbidity,such as with T2DM,on the active targeting capability of ligand-modified nanoparticles,and the results promote the application of nanoparticles for precision medicine.

生育酚纳米乳液的制备及性能研究

为提高α-生育酚(α-Toc)的稳定性和活性,利用超分子包合机理制备纳米乳液,得到了一种稳定性好、透皮效果佳、抗氧化性能优异的α-Toc纳米传递载体。考察了聚山梨醇酯(Tween)的种类、羟丙基-β-环糊精(HP-β-CD)的添加量和α-Toc溶液的添加量对纳米乳液粒径的影响,并借助傅里叶红外光谱、透射电子显微镜、纳米粒度分析仪、热重分析仪和Franz扩散池研究了α-Toc纳米乳液的包埋情况和性能评价。结果表明,所制备的α-Toc超分子纳米乳液的粒径小且分布均匀,在0℃和室温条件下具有良好的储藏稳定性。纳米乳液可以显著增强α-Toc的热稳定性,比未经过包裹的α-Toc具有更优异的抗氧化能力,纳米乳液在化妆品配方中可有效促进α-Toc的透皮吸收。

Biodegradable Materials as Nanocarriers for Drugs and Nutrients

Several important drugs and nutritional supplements are limited by their lack of bioavailability.Nanomaterials display unique beneficial properties that might help improve the bioavailability of drugs and nutritional supplements.Unfortunately,nanomaterials produced from synthetic polymers and metals may have similar difficulties with bioavailability and toxicity.Naturally occurring biopolymers are biodegradable and non-toxic and are adaptable to the synthesis of nanoparticles.Drugs and other substances can be encapsulated or embedded in such particles with an increase in bioavailability.The search for biodegradable nanomaterials is an active research field.This review summarizes the research on nanocrystalline cellulose,starch,lignin,and other biological and environment-friendly nanocomposites which are commonly used as nanocarriers for drugs and nutrients.Further,prospects for the use of biodegradable nanomaterials in targeted therapy,including environmentally responsive therapy,are discussed.

Selectivity regulation of CO2 electroreduction through contact interface engineering on superwetting Cu nanoarray electrodes

Electrocatalytic CO2 reduction is a promising way to mitigate the urgent energy and environmental issues, but how to increase the selectivity for desired product among multiple competi ng reaction pathways remains a bottle neck. Here, we demonstrate that engineering the gas-liquid-solid contact interface on the electrode surface could tailor the selectivity of CO2 reducti on and meanwhile suppress H2 production through regulated reacti on kin etics. Specifically, polytetrafl uoroethyle ne (PTFE) was utilized to modify a Cu nano array electrode as an example, which is able to cha nge the electrode surface from aerophobic to aerophilic state. The en riched nano-tunnels of the Cu nano array electrode can facilitate CO2 transportation and pin gaseous products on the electrode surface. The latter is believed to be the reason that boosts the Faradaic efficie ncy of liquid products by 67% and limits the H2 producti on to less than half of before. This in terface engin eeri ng strategy also lowered H2O (proton) affinity, therefore promoting CO and HCOOH production. Engineering the electrode contact interface controls the reaction kinetics and the selectivity of products, which should be inspiring for other electrochemical reactions.

The structure, expression, and multifaceted role of immune-checkpoint protein VISTA as a critical regulator of anti-tumor immunity, autoimmunity, and inflammation

Among various immunoregulatory molecules,the B7 family of immune-checkpoint receptors consists of highly valuable targets for cancer immunotherapy.Antibodies targeting two B7 family co-inhibitory receptors,CTLA-4 and PD-1,have elicited long-term clinical outcomes in previously refractory cancer types and are considered a breakthrough in cancer therapy.Despite the success,the relatively low response rate(20–30%)warrants efforts to identify and overcome additional immune-suppressive pathways.Among the expanding list of T cell inhibitory regulators,V domain immunoglobulin suppressor of T cell activation(VISTA)is a unique B7 family checkpoint that regulates a broad spectrum of immune responses.Here,we summarize recent advances that highlight the structure,expression,and multi-faceted immunomodulatory mechanisms of VISTA in the context of autoimmunity,inflammation,and anti-tumor immunity.

Common-Ion Effect Triggered Highly Sustained Seawater Electrolysis with Additional NaCl Production

Developing efficient seawater-electrolysis system for mass production of hydrogen is highly desirable due to the abundance of seawater.However,continuous electrolysis with seawater feeding boosts the concentration of sodium chloride in the electrolyzer,leading to severe electrode corrosion and chlorine evolution.Herein,the common-ion effect was utilized into the electrolyzer to depress the solubility of NaCl.Specifically,utilization of 6M NaOH halved the solubility of NaCl in the electrolyte,affording efficient,durable,and sustained seawater electrolysis in NaCl-saturated electrolytes with triple production of H_(2),O_(2),and crystalline NaCl.Ternary NiCoFe phosphide was employed as a bifunctional anode and cathode in simulative and Ca/Mg-free seawater-electrolysis systems,which could stably work under 500 mA/cm^(2) for over 100 h.We attribute the high stability to the increased Na^(+)concentration,which reduces the concentration of dissolved Cl-in the electrolyte according to the common-ion effect,resulting in crystallization of NaCl,eliminated anode corrosion,and chlorine oxidation during continuous supplementation of Ca/Mg-free seawater to the electrolysis system.

Targeting m6A modification inhibits herpes virus 1 infection

The latent infection by herpes virus type 1(HSV-1)may be lifelong in trigeminal ganglia and a suspected cause of Alzheimer's Disease(AD)and Amyotrophic lateral sclerosis(ALS).Whether and how N6-methyladenosine(m6A)modification of viral RNAs affects virus infection are poorly understood.Here,we report that HSV-1 infection enhanced the expression of m6A writers(METTL3,METTL14)and readers(YTHDF1/2/3)at the early infection stage and decreased their expression later on,while suppressed the erasers'(FTO,ALBKH5)expression immediately upon infection to facilitate viral replication.Inhibiting m6A modification by 3-deazaadenosine(DAA)significantly decreased viral replication and reduced viral reproduction over 1000 folds.More interestingly,depleting the writers and readers by siRNAs inhibited virus replication and reproduction;whereas depleting the erasers promoted viral replication and reproduction.Silencing YTHDF3 strikingly decreased viral replication by up to 90%,leading to reduction of up to 10-fold viral replication and over 100-fold virus reproduction,respectively.Depletion of m6A initiator METTL3(by 60%–70%)by siRNA correlatedly decreased viral replication 60%–70%,and reduced virus yield over 30-fold.Consistently,ectopic expression of METTL3 largely increased virus yield.METTL3 knockdown suppressed the HSV-1 intermediate early and early genes(ICP0,ICP8 and UL23)and late genes(VP16,UL44,UL49 and ICP47);while ectopic expression of METTL3 upregulated these gene expression.Results from our study shed the lights on the importance for m6A modification to initiate HSV-1 early replication.The components of m6A modification machinery,particularly m6A initiator METTL3 and reader YTHDF3,would be potential important targets for combating HSV-1 infections.

Dehydrated layered double hydroxides： Alcohothermal synthesis and oxygen evolution activity

Layered double hydroxides （LDHs） are a materials with extensive applications and class of two-dimensional （2D） layered well-developed synthesizing methods in aqueous media. In this work, we introduce an alcohothermal synthesis method for fabricating NiFe-LDHs with dehydrated galleries. The proposed process involves incomplete hydrolysis of urea for the simultaneous precipitation of metal ions, with the resulting water-deficient ethanol environment leading to the formation of a dehydrated structure. The formation of a gallery-dehydrated layer structure was confirmed by X-ray diffraction （XRD）, as well as by a subsequent rehydration process. The methodology introduced here is also applicable for fabricating Fe-based LDHs （NiFe-LDH and NiCoFe-LDH） nanoarrays, which cannot be produced under the same conditions in aqueous media because of the different precipitation processes involved. The LDH nanoarrays exhibit excellent electrocatalytic performance in the oxygen evolution reaction, as a result of their high intrinsic activity and unique structural features. In summary, this study not only introduces a new method for synthesizing LDH materials, but also provides a new route towards highly active and robust electrodes for electrocatalvsis.

河北省邢台市农村地区50岁以上人群视网膜静脉阻塞患病及相关因素分析

目的:调查河北省邢台市农村地区50岁以上人群视网膜静脉阻塞(RVO)患病情况,并对影响因素进行分析。方法:横断面调查研究。于2021年6月至2022年1月选择河北省邢台市信都区农村地区3个乡镇的11个自然村50岁以上常住居民共5046例。采集视力、验光、眼压、裂隙灯显微镜检查及眼底照相等检查的结果。通过评阅眼底照片来诊断RVO,计算RVO的患病率,并通过Logistic回归分析探讨RVO发病的危险因素。结果:共4047例50岁以上常住居民参加本次调查,应答率为80.2%,其中3609例(71.5%)采集到质量合格的双眼眼底照片。通过评阅照片,共62例(62眼)被诊断为RVO,RVO的患病率为1.7%,95%置信区间(CI):1.3%~2.1%。其中,视网膜中央动脉阻塞4例(4眼),患病率0.1%,95%CI:0~0.2%;半侧性视网膜静脉阻塞(HRVO)2例(2眼),患病率0.1%,95%CI:0~0.1%;视网膜分支静脉阻塞56例(56眼),患病率1.5%,95%CI:1.1%~1.9%。Logistic回归分析显示年龄增长(OR=1.05,95%CI:1.01~1.07,P=0.005)、女性(OR=1.84,95%CI:1.06~3.20,P=0.031)、高血压(OR=2.84,95%CI:1.66~4.85,P<0.001)是RVO患病的危险因素。结论:河北省邢台市农村地区50岁以上人群中RVO患病率为1.7%,其中视网膜分支静脉阻塞占RVO患者的大多数,高龄、女性和高血压是RVO的危险因素。

The bacterial effector SidN/Lpg1083 promotes cell death by targeting Lamin-B2

To facilitate survival,replication,and dissemination,the intracellular pathogen Legionella pneumophila relies on its unique type IVB secretion system(T4SS)to deliver over 330 effectors to hijack host cell pathways in a spatiotemporal manner.The effectors and their host targets are largely unexplored due to their low sequence identity to the known proteins and functional redundancy.The T4SS effector SidN(Lpg1083)is secreted into host cells during the late infection period.However,to the best of our knowledge,the molecular characterization of SidN has not been studied.Herein,we identified SidN as a nuclear envelope-localized effector.Its structure adopts a novel fold,and the N-terminal domain is crucial for its specific subcellular localization.Furthermore,we found that SidN is transported by eukaryotic karyopherin Importin-13 into the nucleus,where it attaches to the N-terminal region of Lamin-B2 to interfere with the integrity of the nuclear envelope,causing nuclear membrane disruption and eventually cell death.Our work provides new insights into the structure and function of an L.pneumophila effector protein,and suggests a potential strategy utilized by the pathogen to promote host cell death and then escape from the host for secondary infection.

Significant influences of TiO_(2)crystal structures on NO_(2)and HONO emissions from the nitrates photolysis

The emissions of NO_(2)and HONO from the KNO_(3)photolysis in the presence of TiO_(2)were measured using a round-shape reactor coupled to a NO_(x)analyzer.TiO_(2)played important roles in the emission flux density of NO_(2)(R_(NO_(2)))and HONO(R HONO),depending on crystal structures and mass ratios of TiO_(2).R NO_(2)and R HONO significantly decreased with increasing the rutile and anatase mass ratios from 0 to 8 and 0.5 wt.%,respectively.Nevertheless,with further increasing the anatase mass ratio to 8 wt.%,there was an increase in R_(NO_(2))and R HONO.R NO_(2)on KNO_(3)/TiO_(2)/SiO_(2)had positive correlation with the KNO_(3)mass(1–20 wt.%),irradiation intensity(80–400 W/m^(2))and temperature(278–308 K),while it had the maximum value at the relative humidity(RH)of 55%.R HONO on KNO_(3)/TiO_(2)/SiO_(2)slightly varied with the KNO_(3)mass and temperature,whereas it increased with the irradiation intensity and RH.In addition,the mechanism for NO_(2)and HONO emissions from the nitrates photolysis and atmospheric implications were discussed.