14.46% Efficiency small molecule organic photovoltaics enabled by the well trade-off between phase separation and photon harvesting

Small molecule organic photovoltaics(SMPVs) were prepared by utilizing liquid crystalline donor material BTR-Cl and two similar optical bandgap non-fullerene acceptor materials BTP-BO-4 F and Y6.The BTPBO-4 F and Y6 have the similar optical bandgap and different absorption coefficients.The corresponding binary SMPVs exhibit different short circuit current density(/sc)(20.38 vs.23.24 mA cm^(-2)),and fill factor(FF)(70.77% vs.67.21%).A 14.46% power conversion efficiency(PCE) is acquired in ternary SMPVs with 30 wt% Y6,companied with a JSC of 24.17 mA cm^(-2) a FF of 68.78% and an open circuit voltage(Voc) of 0.87 V.The improvement on PCE of ternary SMPVs should originate from the well trade-off between phase separation and photon harvesting of ternary active layers by incorporating 30 wt% Y6 in acceptors.This work may deliver insight onto the improved performance of SMPVs by superposing the superiorities of binary SMPVs with similar optical bandgap acceptors into one ternary cell.

The 218th amino acid change of Ser to Ala in TaAGPS-7A increases enzyme activity and grain weight in bread wheat

ADP-glucose pyrophosphorylase(AGPase)influences cereal productivity.There are few reports on the function of cytosolic AGPase small subunit in bread wheat(TaAGPS).In the present study,TaAGPS was preferentially expressed in developing endosperm during grain-filling stages in bread wheat.TaAGPS allelic variations were characterized in 143 wheat accessions by PacBio RS II sequencing.Two haplotypes(TaAGPS-7A-TG and TaAGPS-7A-CT)of TaAGPS-7A were identified and corresponding functional markers were developed,whereas no variants of TaAGPS-7B and TaAGPS-7D were detected.TaAGPS-7A was associated with thousand-kernel weight(TKW)by haplotype–trait association analysis in two populations.Near-isogenic lines(NILs)with TaAGPS-7A-TG showed higher TKW and total kernel starch content than those with TaAGPS-7A-CT,owing to the higher AGPase activity of TaAGPS-7A-TG than TaAGPS-7A-CT both in vitro and in vivo.Overexpression of TaAGPS-7A-TG in bread wheat doubled the transcription levels of TaAGPS and increased AGPase activity by 55.7%,resulting in a 3.0-g higher TKW than in the wild type(WT).Knockdown of TaAGPS led to reduced expression of TaAGPS,AGPase activity,and TKW than in the WT.Thus,owing to the 218th amino acid change of Ser to Ala in TaAGPS-7A,the favorable haplotype TaAGPS-7A-TG showed higher AGPase activity,resulting in higher kernel starch content and grain weight.This finding could be applied to increasing starch content and grain weight in bread wheat.

Review on the Effects of Combined Pollution of Lead and Chromium on Soil Microorganisms and Treatment Methods

Heavy metals—Pb and Cr are important causes of environmental pollution, and they often coexist in nature. At present, the effects of Pb and Cr toxicity on soil microorganisms have been less studied, in soil environment which is extremely complex. Simulating soil environment and studying microbial reaction under various heavy metal conditions are of great significance for revealing microbial tolerance to heavy metals. In this paper, firstly, the related concepts of soil rechecking pollution are discussed, and the physical and chemical properties and forms of lead and chromium are introduced accordingly. Secondly, the effects of combined pollution of lead and chromium on soil microbial biomass, soil microbial community structure and soil microbial activity were discussed. Finally, the relevant treatment methods of heavy metal contaminated soil were put forward.

Expert Consensus on Polymyxin Antimicrobial Susceptibility Testing and Clinical Interpretation

The polymyxins are important antimicrobial agents against antibiotic-resistant gram-negative bacilli.In 2020,the Clinical and Laboratory Standards Institute modified the clinical breakpoints for polymyxin susceptibility test by eliminating the"susceptible"interpretive category,only reporting intermediate(≤2 mg/L)and resistant(≥4 mg/L).However,the European Committee on Antimicrobial Susceptibility Testing recommended the use of clinical breakpoints of W2 mg/L as susceptible and>2 mg/L as resistant.The first-line laboratorians and clinicians in China have been perplexed by the inconsistence of international polymyxin clinical breakpoints and discouraged by the difficulty of conducting polymyxin susceptibility testing.Therefore,it is urgently needed to make it clear for the laboratorians in China to know how to accurately carry out polymyxin susceptibility testing and standardize the interpretation of susceptibility testing results.To this end,the experts from relevant fields were convened to formulate this consensus statement on the testing and clinical interpretation of polymyxin susceptibility.Relevant recommendations are proposed accordingly for laboratorians and clinicians to streamline their daily work.

Simulation assessment and prediction of future temperatures in Northwest China from BCC-CSM Model

Three deterministic prediction evaluation methods,including the standard deviation,root-mean-square error,and time correlation coefficient,and three extreme temperature indices were used to assess the performance of the BCC_CSM2_MR model from CMIP6 in simulating the climate of Northwest China based on monthly grid air temperature data from ground stations.The model performance was evaluated using the daily mean temperature,daily minimum temperature,and daily maximum temperature from 1961 to 2014 and future temperature changes in Northwest China under different radiative forcing scenarios.The BCC_CSM2_MR model reproduces well the seasonal changes,spatial distribution,and other characteristics of the daily mean temperature in Northwest China,especially in the Tarim Basin,the Kunlun and Qilian mountains,and Shaanxi.There is still some deviation in the simulation of the daily mean temperature in the high terrains of the Tianshan,Kunlun,and Altai mountains.The model better simulates the daily minimum temperature than the daily maximum temperature.The simulation error is smallest in summer,followed by autumn and winter,and largest in spring.In terms of extreme temperature indices,the deviations are smaller for cold nights,warm nights,and the annual maximum daily minimum temperatures.Furthermore,the model can capture the increase in warm events and the decrease in cold events.Under different forcing scenarios,there is a general warming trend in Northwest China,with the greatest warming in Xinjiang.

Solvent additive-free ternary polymer solar cells with 16.27% efficiency

Ternary strategy has been commonly demonstrated as an efficient method to improve the performance of polymer solar cells(PSCs), which has great potential in application of PSCs due to the simple device fabrication.

效率超过17.2%类合金模型的三元聚合物太阳能电池

本文报道了一系列基于PM6:MF1:Y6体系的双受体三元聚合物太阳能电池,其光电转换效率达到17.22%,在中国计量科学研究院的认证效率为16.8%.该工作系统研究了MF1掺杂比例对器件光伏参数的影响,并澄清三元器件的工作机理.随着MF1掺杂比例的增大,器件的短路电流先升高后降低,开路电压逐渐升高,填充因子先升高后降低再升高.器件短路电流的提高主要归因于有源层光子俘获和形貌的优化.逐渐增大的开路电压表明:MF1和Y6形成了类合金态即分子间激发态能级简并, MF1和Y6良好的兼容性是形成类合金态的前提条件.作者利用Raman mapping,接触角和GIWAXS实验证明MF1和Y6具有较好的兼容性.填充因子的变化主要归因于双受体材料较好的兼容性和不同的LUMO能级.当MF1在受体中的比例为50 wt%时,器件中会形成大量的电子陷阱,导致器件的电子迁移率和填充因子的降低.该工作表明:三元策略是一种提高器件性能的有效方法,有望成为有机光伏器件产业化的首选方案.

Serum IgA,IgM,and IgG responses in COVID-19

Currently,detecting SARS-CoV-2 RNAs is a standard approach for COVID-19 diagnosis.However,there is an urgent need for reliable and rapid serological diagnostic methods to screen SARS-CoV-2-infected people including those who do not have overt symptoms.Most emerging studies described serological tests based on detection of SARS-CoV-2-specific IgM and IgG.1–4 Although detection of SARS-CoV-2-specific IgA in serum has been reported in few papers,5,6 analyses of IgA levels in a larger number of COVID-19 patients are still lacking.

Bi_(2)S_(3) Nanotubes:Facile Synthesis and Growth Mechanism

Synthesis of tubular nanomaterials has become a prolific area of investigation due to their wide range of applications.A facile solution-based method has been designed to fabricate uniform Bi_(2)S_(3)nanotubes with average size of 20 nm×160 nm using only bismuth nitrate(Bi(NO_(3))_(3)·5H_(2)O)and sulfur powder(S)as the reactants and octadecylamine(ODA)as the solvent.Powder X-ray diffraction(XRD),transmission electron microscopy(TEM),high-resolution TEM(HRTEM),and energy dispersive spectroscopy(EDX)experiments were employed to characterize the resulting Bi_(2)S_(3)nanotubes and the classic rolling mechanism was applied to explain their formation process.

Shape Control of CoO and LiCoO_(2) Nanocrystals

Shape control of nanocrystals has become a significant subject in materials science.In this work,we describe a convenient way to achieve morphology-controllable synthesis of CoO nanocrystals including octahedrons and spheres as well as LiCoO_(2) polyhedrons and spheres.In particular,we explain the formation of CoO octahedrons exposing only high-energy(111)facets using theoretical calculations;these should also be a useful tool for directing future face-controlled preparation of other nanocrystals.More importantly,the as-obtained LiCoO_(2) nanocrystals showed different electrochemical performance depending on their morphology,indicating that Li-insertion/deintercalation dynamics might be crystal face-sensitive.

Over 16.7% efficiency of ternary organic photovoltaics by employing extra PC71BM as morphology regulator

Ternary organic photovoltaics(OPVs)are fabricated with PBDB-T-2 Cl:Y6(1:1.2,wt/wt)as the host system and extra PC71BM as the third component.The PBDB-T-2 Cl:Y6 based binary OPVs exhibit a power conversion efficiency(PCE)of 15.49%with a short circuit current(JSC)of 24.98 mA cm^-2,an open circuit voltage(VOC)of 0.868 V and a fill factor(FF)of 71.42%.A 16.71%PCE is obtained in the optimized ternary OPVs with PBDB-T-2 Cl:Y6:PC71BM(1:1.2:0.2,wt/wt)active layer,resulting from the synchronously improved JSC of 25.44 mA cm^-2,FF of 75.66%and the constant VOCof 0.868 V.The incorporated PC71BM may prefer to mix with Y6 to finely adjust phase separation,domain size and molecular arrangement in ternary active layers,which can be confirmed from the characterization on morphology,2 D grazing incidence small and wide-angle X-ray scattering,as well as Raman mapping.In addition,PC71BM may prefer to mix with Y6 to form efficient electron transport channels,which should be conducive to charge transport and collection in the optimized ternary OPVs.This work provides more insight into the underlying reasons of the third component on performance improvement of ternary OPVs,indicating ternary strategy should be an efficient method to optimize active layers for synchronously improving photon harvesting,exciton dissociation and charge transport,while keeping the simple cell fabrication technology.

Re-detectable positive SARS-CoV-2 RNA tests in patients who recovered from COVID-19 with intestinal infection

Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARSCoV-2),a novel coronavirus that causes Coronavirus Disease 2019(COVID-19)(Yang and Wang,2020),has spread to more than 200 countries and infected more than 9,000,000 people as of Jun 2020.Tens of thousands of patients with COVID-19 have recovered and been discharged from hospital.However,there are reports of recovered patients who subsequently tested positive for SARSCoV-2 after discharge(re-detectable positive,RP)(An et al.,2020;Lan et al.,2020),and this has led to increasing focus on the mechanism(s)underlying RP.

儿童青少年高度近视眼眼底特征的研究现状

近视眼屈光度≥-6.00 D时,称为高度近视眼(HM)。HM发展出现病理改变时,称为病理性近视眼(PM)。儿童青少年HM的眼底可出现豹纹状眼底、周边视网膜变性、视盘倾斜、视盘旁区萎缩弧、脉络膜萎缩薄变、眼底微循环障碍及后巩膜葡萄肿等特征;当发展为PM时,可出现后极部脉络膜视网膜萎缩、圆顶状黄斑、近视性黄斑病变、单纯黄斑出血、脉络膜新生血管、Fuchs斑、视网膜劈裂、视网膜裂孔及视网膜脱离等改变。此前的研究主要集中在成人HM眼底改变,而对儿童青少年HM的关注较少。本文中笔者对近年来儿童青少年HM眼底改变的研究现状进行综述。