个人、经历和环境因素如何影响英语教师的评估观——一项叙事研究

已有研究表明教师的评估观受其个人特征、经历和特定的社会文化背景影响,但这些因素如何影响教师的评估观尚未得到充分研究。本研究基于48名中国高中英语教师的叙述框架数据,探究教师评估观及其影响因素。结果显示,教师普遍认同以促学为导向的评估目的;一系列因素对教师的评估观产生了不同程度的影响,包括个人因素(教师的主观能动性)、经历因素(教师对评估的[反]学徒式观察)以及环境因素(应试文化)。本文进而讨论了教师如何在促学导向的评估目的和问责导向的评估目的之间进行磋商与妥协,以及教师主观能动性、作为被评估者的情感体验和应试文化如何塑造教师评估观。研究对教师评估观研究以及教师评估素养政策、实践和专业发展具有重要启示。

中国细胞重编程和多能干细胞研究进展

近几十年是干细胞领域飞速发展的重要时期。随着中国经济实力的发展壮大,科研实力也在稳步增强,干细胞研究领域达到了国际并跑甚至领跑的水平。本文从体细胞核移植、诱导多能干细胞、单倍体多能干细胞和胚胎早期发育研究4个方面,对中国细胞重编程和干细胞领域的研究进展进行了历史性回顾,总结了中国科学家在相关领域所取得的重要科研成果。随着单细胞测序技术的发展,各种发育过程将实现更为深入的解读,干细胞的临床应用在中国也会大放异彩。

Novel confinement combustion method of nanosized WC/C for efficient electrocatalytic oxygen reduction

Nanosized tungsten carbide(WC)/carbon(C)catalyst was synthesized via a novel ultra-rapid confinement combustion synthesis method.The amount of activated carbon(AC)plays an important role in the morphology and structure,controlling both the precursor and final powder.The WC particles synthesized inside the pores of the AC had been 10-20 nm because of the confinement of the pore structure and the large specific surface area of AC.When used for oxygen reduction performance,the half-wave potential was−0.24 V,and the electron transfer number was 3.45,indicating the main reaction process was the transfer of four electrons.The detailed electrocatalytic performance and underlying mechanism were investigated in this work.Our study provides a novel approach for the design of catalysts with new compositions and new structures,which are significant for promoting the commercialization of fuel cells.

基于分层安全控制结构的导弹装备任务安全性动态评价方法

长期贮存的多任务环境与复杂工况,对导弹装备的风险有效抑制与安全性准确评价提出了严格的要求。然而,导弹装备是典型的人-机-环耦合复杂系统,传统的安全性分析与评价方法无法满足其动态变化与准确量化的需求。为此,提出基于分层安全控制结构的导弹装备安全性动态评价方法,实现长期贮存任务情境下安全性的准确评价。首先,针对导弹装备的任务剖面特点,构建过程、任务、功能、信息和组织的多视图体系模型,实现任务过程与资源的准确描述。其次,构建分层安全控制结构模型,明确任务的事故致因因素与事故链。同时,针对导弹装备任务特点,构建面向长期贮存复杂多变环境下的人因绩效评价体系,实现人-机-环耦合条件下人因失误率的准确评价。然后,提出了一种融合STAMP和CREAM的安全动态反馈评价方法,以仿真的形式获得导弹任务的事故率。最后,对导弹测试任务进行案例分析,所提方法在人-机-环耦合情境下明确协调、控制和反馈共3类6个典型事故链,同时事故率精度提升70.08%,验证了所提方法的有效性与优越性。

Effect of SARS-CoV-2 infection in early pregnancy on placental development

Dear Editor,Since the COVID-19 pandemic, the potential risks associated with maternal SARS-CoV-2 infection and its effect on fetal development have been a subject of considerable public concern. Previous studies have shown that SARS-CoV-2 infection during pregnancy may increase the incidence of adverse outcomes.

Improved in situ sequencing for high-resolution targeted spatial transcriptomic analysis in tissue sections

Spatial transcriptomics enables the study of localization-indexed gene expression activity in tissues,providing the transcriptional landscape that in turn indicates the potential regulatory networks of gene expression.In situ sequencing(ISS)is a targeted spatial transcriptomic technique,based on padlock probe and rolling circle amplification combined with next-generation sequencing chemistry,for highly multiplexed in situ gene expression profiling.Here,we present improved in situ sequencing(IISS)that exploits a new probing and barcoding approach,combined with advanced image analysis pipelines for high-resolution targeted spatial gene expression profiling.We develop an improved combinatorial probe anchor ligation chemistry using a 2-base encoding strategy for barcode interrogation.The new encoding strategy results in higher signal intensity as well as improved specificity for in situ sequencing,while maintaining a streamlined analysis pipeline for targeted spatial transcriptomics.We show that IISS can be applied to both fresh frozen tissue and formalin-fixed paraffin-embedded tissue sections for single-cell level spatial gene expression analysis,based on which the developmental trajectory and cell-cell communication networks can also be constructed.

Bilineage embryo-like structure from EPS cells can produce live mice with tetraploid trophectoderm

Self-organized blastoids from extended pluripotent stem(EPs)cells possess enormous potential for investigating postimplantation embryo development and related diseases.However,the limited ability of postimplantation development of Eps-blastoids hinders its further application.In this study,single-cell transcriptomic analysis indicated that the“trophectoderm(TE)-like structure”of EPSblastoids was primarily composed of primitive endoderm(PrE)-related cells instead of TE-related cells.We further identified PrE-like cells in EPS cell culture that contribute to the blastoid formation with TE-like structure.Inhibition of PrE cell differentiation by inhibiting MEK signaling or knockout of Gata6 in EPS cells markedly suppressed EPS-blastoid formation.Furthermore,we demonstrated that blastocyst-like structures reconstituted by combining the EPs-derived bilineage embryo-like structure(BLEs)with either tetraploid embryos or tetraploid TE cells could implant normally and develop into live fetuses.In summary,our study reveals that TE improvement is critical for constructing a functional embryo using stem cells in vitro.

Convolution neural network and 77 GHz millimeter wave radar based intelligent liquid classification system

An intelligent liquid classification system based on 77 GHz millimeter wave radar and convolution neural network are proposed in this paper.The data are collected by the AWR1843 radar platform and processed by the neural network on the host PC in real-time.The doppler heatmap generated by radar signal processing is tried for the first time as the input of the system.The information carried by the heatmap in 2 dimensions is analyzed and the reason why the doppler heatmap could be used for classification is explained.The feasible experiment proved that the proposed method can successfully classify 8 kinds of common liquid with high accuracy.The result of the experiment is explained and the limitations of the experiment are discussed.It can be drawn that the combination of FMCW millimeter wave radar and convolution neural network is a method with great potential for liquid classification.The advantages of real time,non-invasive and unilateral measurement can also be used for the detection of dangerous liquids.

Occurrence and distribution of antibiotic resistance genes in the sediments of the East China Sea bays

The coastal area of the East China Sea has experienced rapid urbanization and industrialization in China since 1980 s, resulting in severe pollution of its environments.Antibiotic resistance genes(ARGs) are regarded as a kind of emerging pollutant with potential high risk. The sediment samples were collected from Hangzhou Bay(HB),Xiangshan Bay(XB), and Taizhou Bay(TB) to investigate the spatial occurrence and distribution of 27 ARGs and class I integron–integrase gene(intI1) in the coastal area of the East China Sea. The PCR results showed the frequent presence of 11 ARGs and intI1 in the sediments of the three bays. The qPCR results further showed that sulfonamide resistance was the most prevalent ARG type and antibiotic target replacement and protection were the most important resistance mechanisms in the sediments. Regarding the subtype of ARGs, sulI, tetW, and dfrA13 were the most abundant ARGs, in which sulI was higher in TB(based on both the absolute and relative abundances) and dfrA13 was higher in HB(based on the relative abundances). The network analysis revealed that intI1 had significant correlations with tetC, sulI, sulII, and blaPSE-1. Oil was the key connected factor, which had positive connections with sulI, sulII, and blaPSE-1. In addition, the joint effect of heavy metals and nutrients & organic pollutants might be crucial for the fate of ARGs in the coastal sediments.

Nuclear m^(6)A reader YTHDC1 regulates the scaffold function of LINE1 RNA in mouse ESCs and early embryos

N^(6)-methyladenosine(m^(6)A)on chromosome-associated regulatory RNAs(carRNAs),including repeat RNAs,plays important roles in tuning the chromatin state and transcription,but the intrinsic mechanism remains unclear.Here,we report that YTHDC1 plays indispensable roles in the self-renewal and differentiation potency of mouse embryonic stem cells(ESCs),which highly depends on the m^(6)A-binding ability.Ythdcl is required for sufficient rRNA synthesis and repression of the 2-cell(2C)transcriptional program in ESCs,which recapitulates the transcriptome regulation by the LINE1 scaffold.Detailed analyses revealed that YTHDC1 recognizes m^(6)A on LINE1 RNAs in the nucleus and regulates the formation of the LINE1-NCL partnership and the chromatin recruitment of KAP1.Moreover,the establishment of H3K9me3 on 2C-related retrotrans-posons is interrupted in Ythdcl-depleted ESCs and inner cell mass(ICM)cells,which consequently increases the transcriptional activities.Our study reveals a role of m^(6)A in regulating the RNA scaffold,providing a new model for the RNA-chromatin cross-talk.

One-step synthesis of thermally stable artificial multienzyme cascade system for efficient enzymatic electrochemical detection

Recently,metal-organic framework(MOF)-based multienzyme systems integrating different functional natural enzymes and/or nanomaterial-basedartificial enzymes are attracting increasing attention due to their high catalytic efficiency and promising application in sensing.Simpleand controllable integration of enzymes or nanozymes within MOFs is crucial for achieving efficient cascade catalysis and high stability.Here,we report a facile electrochemical assisted biomimetic mineralization strategy to prepare an artificial multienzyme system for efficient electrochemicaldetection of biomolecules.By using the G0x@Cu-MOF/copper foam(G0x@Cu-MOF/CF)architecture as a proof of concept,efficientenzyme immobilization and cascade catalysis were achieved by in situ encapsulation of glucose oxidase(GOx)within MOFs layer grown onthree-dimensional(3D)porous conducting CF via a facile one-step electrochemical assisted biomimetic mineralization strategy.Due to thebio-electrocatalytic cascade reaction mechanism,this well-designed GOx@Cu-MOF modified electrode exhibited superior catalytic activityand thermal stability for glucose sensing.Notably,the activity of GOx@Cu-MOF/CF still remained at ca.80%after being incubated at 80℃.In sharp contrast,the activity of the unprotected electrode was reduced to the original 10%after the same treatment.The design strategypresented here may be useful in fabricating highly stable enzyme@MOF composites applied for efficient photothermal therapy and otherplatform under high temperature.

Xrcc1增强碱基切除修复能力进而提高诱导多能干细胞基因组稳定性和多能性的研究

诱导多能干细胞(iPSC)因其强大的自我更新和分化能力而具有广阔的应用前景.然而,多个研究表明体细胞诱导重编程过程会引入数以千计的遗传畸变,进而带来临床应用的安全性问题,已有前期研究证明单核苷酸变异(SNVs)的逐渐积累会致使iPSC丧失发育潜能,但致使SNVs产生并积累的原因还尚未探明.本研究通过对不同DNA损伤修复通路的筛选验证后,发现重编程过程早中期碱基切除修复(BER)效率的不足是导致SNVs积累的重要原因,进一步的研究发现XRCC1可以显著增强重编程前中期的BER,从而降低引入的SNVs,提高iPSC基因组的稳定性.同时,XRCC1介导的BER增强也提高了体细胞诱导重编程的效率.更为重要的是,体内嵌合体实验证实高效的BER可以显著提高iPSC的质量.综上,该研究可以有效提高iPSC基因组的稳定性和多能性,为其临床应用的安全性提供了新思路.

Esrrb plays important roles in maintaining self-renewal of trophoblast stem cells (TSCs) and reprogramming somatic cells to induced TSCs

Trophoblast stem cells (TSCs), which can be derived from the trophoectoderm of a blastocyst, have the ability to sustain self-renewal and differentiate into various placental trophoblast cell types. Meanwhile, essential insights into the molecular mechanisms controlling the placental development can be gained by using TSCs as the cell model. Esrrb is a transcription factor that has been shown to play pivotal roles in both embryonic stem cell (ESC) and TSC, but the precise mechanism whereby Esrrb regulates TSC-specific transcriptome during differentiation and reprogramming is still largely unknown. In the present study, we elucidate the function of Esrrb in self-renewal and differentiation of TSCs, as well as during the induced TSC (iTSC) reprogramming. We demonstrate that the precise level of Esrrb is critical for stem state maintenance and further trophoblast differentiation of TSCs, as ectopically expressed Esrrb can partially block the rapid differentiation of TSCs in the absence of fibroblast growth factor 4. However, Esrrb depletion results in downregulation of certain key TSC-specific transcription factors, consequently causing a rapid differentiation of TSCs and these Esrrb-deficient TSCs lose the ability of hemorrhagic lesion formation in vivo. This function of Esrrb is exerted by directly binding and activating a core set of TSC-specific target genes including Cdx2, Eomes, Sox2, Fgfr4, and Bmp4. Furthermore, we show that Esrrb overexpression can facilitate the MEF-to-iTSC conversion. Moreover, Esrrb can substitute for Eomes to generate GEsTM-iTSCs. Thus, our findings provide a better understanding of the molecular mechanism of Esrrb in maintaining TSC self-renewal and during iTSC reprogramming.

BMP4 preserves the developmental potential of mESCs through Ube2s-and Chmp4b-mediated chromosomal stability safeguarding

Chemically defined medium is widely used for culturing mouse embryonic stem cells(mESCs),in which N2B27 works as a substitution for serum,and GSK3βand MEK inhibitors(2i)help to promote ground-state pluripo-tency.However,recent studies suggested that MEKi might cause irreversible defects that compromise the developmental potential of mESCs.Here,we demon-strated the deficient bone morphogenetic protein(BMP)signal in the chemically defined condition is one of the main causes for the impaired pluripotency.Mechanisti-cally,activating the BMP signal pathway by BMP4 could safeguard the chromosomal integrity and proliferation capacity of mESCs through regulating downstream tar-gets Ube2s and Chmp4b.More importantly,BMP4 pro-motes a distinct in vivo developmental potential and a long-term pluripotency preservation.Besides,the pluripotent improvements driven by BMP4 are superior to those by attenuating MEK suppression.Taken together,our study shows appropriate activation of BMP signal is essential for regulating functional pluripotency and reveals that BMP4 should be applied in the serum-free culture system.

Influence of earthquake input angle on seismic response of curved girder bridge

The maximum seismic response of curved bridge is significantly related to the input angle of designated earthquake. Owing to structure irregularities, bridge reactions result from the interaction between the moment and torsion forces. Based on the solving of the seismic response of structure excited by a one-way earthquake input, a uniform expression of the unfavorable angle of the earthquake input was derived, and the corresponding maximum response of structure was determined. Considering the orthotropic and skewed dual- directional earthquake input manners, the most unfavorable angles for the two cases were also derived, respectively. Furthermore, a series finite element models were built to analyze the multi-component seismic responses by examining an example of curved girder bridge considering the variation of curvature radius and the bearings arrangement. The seismic responses of the case bridges, were excited by earthquakes at different input angles, and were calculated and analyzed using a response spectrum method. The input angles of earthquake excitation were progressively increased. From the analysis and comparison based on the calculation results mentioned above, the most unfavorable angle of earthquake excitation corresponding to the maximum seismic response of the curved bridge could be determined. It was shown that the most unfavorable angles of earthquake input resulted from the different response combination methods were essentially coherent.

Excitatory Crossmodal Input to a Widespread Population of Primary Sensory Cortical Neurons

Crossmodal information processing in sensory cortices has been reported in sparsely distributed neurons under normal conditions and can undergo experience-or activity-induced plasticity.Given the potential role in brain function as indicated by previous reports,crossmodal connectivity in the sensory cortex needs to be further explored.Using perforated whole-cell recording in anesthetized adult rats,we found that almost all neurons recorded in the primary somatosensory,auditory,and visual cortices exhibited significant membrane-potential responses to crossmodal stimulation,as recorded when brain activity states were pharmacologically down-regulated in light anesthesia.These crossmodal cortical responses were excitatory and subthreshold,and further seemed to be relayed primarily by the sensory thalamus,but not the sensory cortex,of the stimulated modality.Our experiments indicate a sensory cortical presence of widespread excitatory crossmodal inputs,which might play roles in brain functions involving crossmodal information processing or plasticity.

Correction to:Nuclear m6A reader YTHDC1 regulates the scaffold function of LINE1 RNA in mouse ESCs and early embryos

CORRECTION TO:PROTEIN CELL(2021)HTTPS://DOI.ORG/10.1007/S13238-021-00837-8 In the original publication of the article figure 1 is incorrectly published.The correct Figure 1 is provided in this correction.OPEN ACCESS This article is licensed under a Creative Commons Attribution 4.0 International License,which permits use,sharing,adaptation,distribution and reproduction in any medium or format,as long as you give appropriate credit to the original author(s)and the source,provide a link to the Creative Commons licence,and indicate if changes were made.The images or other third party material in this article are included in the article's Creative Commons licence,unless indicated otherwise in a credit line to the material.If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use,you will need to obtain permission directly from the copyright holder.To view a copy of this licence,visit https://creativecommons.org/licenses/by/4.0/.

Understanding innovation diffusion and adoption strategies in megaproject networks through a fuzzy system dynamic model

Innovation and knowledge diffusion in megaprojects is one of the most complicated issues in project management.Compared with conventional projects,megaprojects typically entail large-scale investments,long construction periods,and conflicting stakeholder interests,which result in a distinctive pattern of innovation diffusion.However,traditional investigation of innovation diffusion relies on subjective feedback from experts and frequently neglects inter-organizational knowledge creation,which frequently emerges in megaprojects.Therefore,this study adopted project network theory and modeled innovation diffusion in megaprojects as intra-and interorganizational learning processes.In addition,system dynamics and flizzy systems were combined to interpret experts9 subject options as quantitative coefficients of the project network model.This integrated model will assist in developing an insightful understanding of the mechanisms of innovation diffusion in megaprojects.Three typical network structures,namely,a traditional megaproject procurement organization(TMO),the environ megaproject organization(EMO),and an integrated megaproject organization(IMO),were examined under six management scenarios to verify the proposed analytic paradigm.Assessment of project network productivity suggested that the projectivity of the TMO was insensitive to technical and administrative innovations,the EMO could achieve substantial improvement from technical innovations,and the 1MO trended incompatibly with administrative innovations.Thus,industry practitioners and project managers can design and reform agile project coordination by using the proposed quantitative model to encourage innovation adoption and reduce productivity loss at the start of newly established collaborations.

Pathogenesis of seizures and epilepsy after stroke

Stroke is the most frequent cause of secondary epilepsy in the elderly.The incidence of cerebral stroke is increasing with the extension of life expectancy,and the prevalence of post-stroke epilepsy(PSE)is rising.There are various seizure types after stroke,and the occurrence of epilepsy is closely related to the type and location of stroke.Moreover,the clinical treatment of post-stroke epilepsy is difficult,which increases the risk of disability and death,and affects the prognosis and quality of life of patients.Now seizure and epilepsy after stroke is more and more get the attention of the medical profession,has been more and more researchers have devoted to seizures after stroke and PSE clinical and basic research,and hope to get a scientific and unified guideline,to give timely and effective treatment,but the exact pathophysiologic mechanism has not yet formed a unified conclusion.It has been found that ion channels,neurotransmitters,proliferation of glial cells,genetics and other factors are involved in the occurrence and development of PSE.In this review,we discuss the pathogenesis of early-onset epileptic seizures and late-onset epilepsy after stroke,in order to provide a basis for clinicians to understand the disease,and expect to provide ideas for future exploration.

PDGFR in PDGF-BB/PDGFR Signaling Pathway Does Orchestrates Osteogenesis ina Temporal Manner

Platelet-derived growth factor-BB(PDGF-BB)/platelet-derived growth factor receptor-β(PDGFR-β)pathway is conventionally considered as an important pathway to promote osteogenesis;however,recent study suggested its role during osteogenesis to be controversial.Regarding the differential functions of this pathway during 3 stages of bone healing,we hypothesized that temporal inhibition of PDGF-BB/PDGFR-βpathway could shift the proliferation/differentiation balance of skeletal stem and progenitor cells,toward osteogenic lineage,which leads to improved bone regeneration.We first validated that inhibition of PDGFR-βat late stage of osteogenic induction effectively enhanced differentiation toward osteoblasts.This effect was also replicated invivo by showing accelerated bone formation when block PDGFR-βpathway at late stage of critical bone defect healing mediated using biomaterials.Further,we found that such PDGFR-βinhibitor-initiated bone healing was also effective in the absence of scaffold implantation when administrated intraperitoneally.Mechanistically,timely inhibition of PDGFR-βblocked extracellular regulated protein kinase 1/2 pathway,which shift proliferation/differentiation balance of skeletal stem and progenitor cell to osteogenic lineage by upregulating osteogenesis-related products of Smad to induce osteogenesis.This study offered updated understanding of the use of PDGFR-βpathway and provides new insight routes of action and novel therapeutic methods in the field of bone repair.