创新对企业MD&A叙述性信息披露策略的影响

研发和创新具有投入高、周期长和不确定性高的特征,这使得高创新企业面临较低的透明度和较高的专有成本。一方面为了满足投资者决策需要,防止信息不对称所导致的价值低估,企业有动机提供更多信息;另一方面创新所伴有的专有成本,又使得企业存在专有信息被现有和潜在竞争对手获取的顾虑,从而选择提供模糊信息的披露策略。本文利用2001—2019年A股上市公司数据,检验了企业创新对MD&A叙述性信息披露策略的影响。研究结果表明,随着企业创新的增加,企业叙述性信息披露的信息含量上升(文本相似度显著下降),但是披露的信息质量下降(文本可读性显著降低)。该结果说明管理层既希望向投资者传递更多信息,又担心来自竞争对手的威胁,即管理层会选择释放更多的叙述性信息并模糊表达。上述结果存在于行业竞争更激烈、融资约束程度较高和高管持股比例较高的情况下。本文结论对知识产权信息披露与管理层披露策略选择具有一定的借鉴意义。

医学遗传学教学案例库的建设探究

医学遗传学是探讨遗传因素相关疾病的诊断、预防与治疗的基础医学类课程,本门课要求学生具备较强的逻辑思维,有独立思考和分析解决问题的能力。单一的“填鸭式”课堂教学很难调动学生的自主学习,无法达到医学遗传学的教学效果。案例研讨式教学打破了被动的传统教学模式,教师给出临床典型案例,学生围绕案例的相关问题准备材料,主动展开课堂讨论,以教与学互动的方式融汇贯通了本门课程的重点与难点,教学效果显著。自2013年起,本教研组针对临床医学本科生开展了案例研讨式教学。本文根据课程的教学计划和案例研讨式教学的实际情况,筛选并分类整理了所收集的临床案例资料,分章节归纳汇编了8个章节的教学案例库,基本涵盖了疾病遗传学与临床遗传学的教学重难点。医学遗传学教学案例库的建设实现了临床案例与教学的深度融合,学生以更为直观的方式理解掌握教学重难点,有助于激发学生的创新思维,提高学生的学习兴趣与课堂参与度。

Suppress oxygen evolution of lithium-rich manganese-based cathode materials via an integrated strategy

Improving the reversibility of anionic redox and inhibiting irreversible oxygen evolution are the main challenges in the application of high reversible capacity Li-rich Mn-based cathode materials.A facile synchronous lithiation strategy combining the advantages of yttrium doping and LiYO_(2) surface coating is proposed.Yttrium doping effectively suppresses the oxygen evolution during the delithiation process by increasing the energy barrier of oxygen evolution reaction through strong Y–O bond energy.LiYO_(2) nanocoating has the function of structural constraint and protection,that protecting the lattice oxygen exposed to the surface,thus avoiding irreversible oxidation.As an Li^(+) conductor,LiYO_(2) nano-coating can provide a fast Li^(+) transfer channel,which enables the sample to have excellent rate performance.The synergistic effect of Y doping and nano-LiYO_(2) coating integration suppresses the oxygen release from the surface,accelerates the diffusion of Li^(+)from electrolyte to electrode and decreases the interfacial side reactions,enabling the lithium ion batteries to obtain good electrochemical performance.The lithium-ion full cell employing the Y-1 sample(cathode)and commercial graphite(anode)exhibit an excellent specific energy density of 442.9 Wh kg^(-1) at a current density of 0.1C,with very stable safety performance,which can be used in a wide temperature range(60 to-15℃)stable operation.This result illustrates a new integration strategy for advanced cathode materials to achieve high specific energy density.

Laccase/caffeic acid-catalyzed crosslinking coupled with galactomannan alters the conformational structure of ovalbumin and alleviates Th2-mediated allergic asthma

Ovalbumin(OVA)is the major allergenic protein that can induce T helper 2(Th2)-allergic reactions,for which current treatment options are inadequate.In this study,we developed a polymerized hypoallergenic OVA product via laccase/caffeic acid(Lac/CA)-catalyzed crosslinking in conjunction with galactomannan(Man).The formation of high molecular weight crosslinked polymers and the Ig G-binding were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)and Western blotting.The study indicated that Lac/CA-catalyzed crosslinking plus Man conjugation substantially altered secondary and tertiary structures of OVA along with the variation in surface hydrophobicity.Gastrointestinal digestion stability assay indicated that crosslinked OVA exhibited less resistance in simulated gastric fluid(SGF)and simulated intestinal fluid(SIF).Mouse model study indicated that Lac-Man/OVA ameliorated eosinophilic airway inflammatory response and efficiently downregulated the expression of Th2-related cytokines(interleukin(IL)-4,IL-5,and IL-13),and upregulated IFN-γand IL-10 expression.Stimulation of bone marrow-derived dendritic cells with Lac-Man/OVA suppressed the expression of phenotypic maturation markers(CD80 and CD86)and MHC class II molecules,and suppressed the expression levels of proinflammatory cytokines.The knowledge obtained in the present study offers an effective way to acquire a hypoallergenic OVA product that can have a therapeutic effect in alleviating OVA-induced allergic asthma.

Status and Opportunities of Zinc Ion Hybrid Capacitors: Focus on Carbon Materials, Current Collectors, and Separators

Zinc ion hybrid capacitors(ZIHCs), which integrate the features of the high power of supercapacitors and the high energy of zinc ion batteries, are promising competitors in future electrochemical energy storage applications. Carbon-based materials are deemed the competitive candidates for cathodes of ZIHC due to their cost-effectiveness, high electronic conductivity, chemical inertness, controllable surface states, and tunable pore architectures. In recent years, great research efforts have been devoted to further improving the energy density and cycling stability of ZIHCs. Reasonable modification and optimization of carbon-based materials offer a remedy for these challenges. In this review, the structural design, and electrochemical properties of carbon-based cathode materials with different dimensions, as well as the selection of compatible, robust current collectors and separators for ZIHCs are discussed. The challenges and prospects of ZIHCs are showcased to guide the innovative development of carbon-based cathode materials and the development of novel ZIHCs.

Peripheral CD4^(+)CD8^(+) double positive T cells:A potential marker to evaluate renal impairment susceptibility during systemic lupus erythematosus

Lupus nephritis(LN) has a high incidence in systemic lupus erythematosus(SLE) patients, but there is a lack of sensitive predictive markers. The purpose of the study was to investigate the association between the CD4^(+)CD8^(+)double positive T(DPT) lymphocytes and LN. The study included patients with SLE without renal impairment(SLE-NRI), LN, nephritic syndrome(NS), or nephritis. Peripheral blood lymphocyte subsets were analyzed by flow cytometry. Biochemical measurements were performed with peripheral blood in accordance with the recommendations proposed by the National Center for Clinical Laboratories. The proportions of DPT cells in the LN group were significantly higher than that in the SLE-NRI group(t=4.012, P<0.001), NS group(t=3.240,P=0.001), and nephritis group(t=2.57, P=0.011). In the LN group, the risk of renal impairment increased significantly in a DPT cells proportion-dependent manner. The risk of LN was 5.136 times(95% confidence interval, 2.115–12.473) higher in cases with a high proportion of DPT cells than those whose proportion of DPT cells within the normal range. These findings indicated that the proportion of DPT cells could be a potential marker to evaluate LN susceptibility, and the interference of NS and nephritis could be effectively excluded when assessing the risk of renal impairment during SLE with DPT cell proportion.

Dual functions of PsmiR172b-PsTOE3 module in dormancy release and flowering in tree peony (Paeonia suffruticosa)

MicroRNAs(miRNAs)are non-coding RNAs that interact with target genes and are involved in many physiological processes in plants.miR172-AP2 mainly plays a role in the regulation of f lowering time and floral organ differentiation.Bud dormancy release is necessary for forcing culture of tree peony in winter,but the mechanism of dormancy regulation is unclear.In this study,we found that a miR172 family member,PsmiR172b,was downregulated during chilling-induced bud dormancy release in tree peony,exhibiting a trend opposite to that of PsTOE3.RNA ligase-mediated(RLM)5-RACE(rapid amplification of cDNA ends)confirmed that miR172b targeted PsTOE3,and the cleavage site was between bases 12(T)and 13(C)within the complementary site to miR172b.The functions of miR172b and PsTOE3 were detected by virus-induced gene silencing(VIGS)and their overexpression in tree peony buds.PsmiR172b negatively regulated bud dormancy release,but PsTOE3 promoted bud dormancy release,and the genes associated with bud dormancy release,including PsEBB1,PsEBB3,PsCYCD,and PsBG6,were upregulated.Further analysis indicated that PsTOE3 directly regulated PsEBB1 by binding to its promoter,and the specific binding site was a C-repeat(ACCGAC).Ectopic expression in Arabidopsis revealed that the PsmiR172b-PsTOE3 module displayed conservative function in regulating f lowering.In conclusion,our results provided a novel insight into the functions of PsmiR172-PsTOE3 and possible molecular mechanism underlying bud dormancy release in tree peony.

实验教学与绿色化学的融合——一个绿色Suzuki-Miyaura交叉偶联反应教学实验研究

Suzuki-Miyaura交叉偶联反应是现代合成化学中一个重要反应,广泛应用于药物、天然产物、染料等化合物的合成。受限于催化剂价格高昂、反应操作复杂等原因,涉及该反应的实验难以在本科生教学实验中推广。本文介绍了一种绿色钯催化Suzuki-Miyaura交叉偶联反应的有机合成实验。催化剂无需制备且钯用量少,并可被多次循环利用,解决了实验成本问题;该实验中的溶剂为水、反应条件温和、反应速率快、产物分离便捷,展示了绿色化学的安全优势,可引入高年级本科课程。本实验中,学生既可以学习诺贝尔奖级有机合成反应,又可以通过对催化剂的回收再利用和对反应的绿色评估,体会到绿色化学在过渡金属催化有机反应中的节能减排和可持续发展优势。

miRNA-15a通过靶向Wnt3a调控Wnt/β-catenin信号通路抑制卵巢癌的发展和转移

目的:研究在卵巢癌发展转移进程中miRNA-15a的作用,并探讨其作用机制。方法:收集锦州医科大学附属第一医院2012年5月至2015年6月32例卵巢癌患者的手术切除标本,采用RT-PCR检测miRNA-15a表达。将培养的卵巢癌SKOV-3细胞分为转染miRNA-15a模拟物的实验组和转染无义miRNA的对照组,采用CCK8、Transwell及流式细胞术检测细胞增殖、侵袭和凋亡的变化,采用Western blot法检测相关蛋白表达。通过生物信息学方法预测miRNA-15a靶基因,采用双荧光素酶报告基因实验结合Western blot法验证miRNA-15a对靶基因的调控。检测Wnt3a与miRNA-15a模拟物共转染SKOV-3细胞后对细胞增殖和侵袭的影响。结果:与癌旁组织中的miRNA-15a相对表达量0.692±0.228相比,显著低于卵巢癌组织中的0.911±0.209,差异具有统计学意义(P<0.05)。与对照组细胞增殖能力相比,miRNA-15a过表达显著抑制实验组细胞增殖能力,差异具有统计学意义(P<0.05)。与对照组189.667±14.742相比,miRNA-15a过表达显著抑制实验组的细胞侵袭能力96.667±13.614,差异具有统计学意义(P<0.05)。miRNA-15a过表达实验组的细胞凋亡率27.400%±0.854%显著高于对照组细胞凋亡率6.933%±0.379%,差异具有统计学意义(P<0.05)。miRNA-15a模拟物下调Wnt3a和β-catenin的表达,抑制细胞周期蛋白(Cyclin D1)和血管内皮生长因子(vascular endothelial growth factor,VEGF)的表达,促进E-钙离子依赖的细胞黏附素(E-calcium-dependent adhesion,E-cad)的表达。双荧光素酶报告基因实验和Western blot结果表明miRNA-15a靶向抑制Wnt3a表达。上调Wnt3a能显著降低miRNA-15a对卵巢癌细胞增殖、侵袭和对Wnt/β-catenin信号通路的抑制作用。结论:miRNA-15a通过靶向Wnt3a调控Wnt/β-catenin信号通路的激活以抑制卵巢癌的发展和转移。

在化学教学中推广科普知识——以趣谈指纹显现技术为例

指纹是公认的法庭科学“证据之首”,指纹显现技术是寻找指纹的第一步,也是关键步骤。笔者在本科生通选课程“化学与现代社会”的“化学与刑事技术”一章中,采用翻转课堂和基于小组学习(Team-Based Learning,TBL)的授课方式,鼓励学生将指纹拟人化为一名面孔多变的“怪盗”,将各种指纹显现技术人格化为指纹显现技术部的侦查员,以趣谈的形式介绍了几种指纹显现技术中所涉及的化学原理,丰富了学生对指纹显现技术科学认识的同时,提高了其科学素养和学习兴趣。

A Facile Route for the Large Scale Fabrication of Graphene Oxide Papers and Their Mechanical Enhancement by Cross-linking with Glutaraldehyde

A facile route for the large scale production of graphene oxide(GO) papers and their mechanical enhancement has been presented in this work. The novel paper-like GO made from individual GO sheets in aqueous suspension can be achieved in large scale by a simple drop casting method on hydrophobic substrates.Significant enhancement in mechanical stiffness(341%) and fracture strength(234%) of GO paper have been achieved upon modification with a small amount(less than 10 wt%) of glutaraldehyde(GA). The cross-linking reaction takes place between hydroxyl groups on the surface of GO and aldehyde groups of GA, through forming hemiacetal structure, which can result in distinct mechanical enhancement of the GO papers.

Improved electrochemical hydrogen storage properties of Mg-Y thin films as a function of substrate temperature

Pd-capped Mg78Y22 thin films have been prepared by direct current magnetron co-sputtering system at different substrate temperatures and their electrochemical hydrogen storage properties have been investigated.It is found that rising substrate temperature to 60 ℃ can coarsen the surface of thin film,thus facilitating the diffusion of hydrogen atoms and then enhancing its discharge capacity to 1725 mAh·g-1.Simultaneously,the cyclic stability is effectively improved due to the increased adhesion force between film and substrate as a function of temperature.In addition,the specimen exhibits a very long and flat discharge plateau at about —0.67 V,at which nearly 60%of capacity is maintained.The property is favorable for the application in metal hydride/nickel secondary batteries.The results indicate that rising optimal substrate temperature has a beneficial effect on the electrochemical hydrogen storage of Mg-Y thin films.

硬脂酸改性NiO-TiO2薄膜的摩擦学性能

利用溶胶–凝胶技术结合自组装技术在45#钢表面制备了具有优异减摩耐磨性能的有机–无机复合薄膜。首先采用溶胶–凝胶技术在钢基底上制备NiO-TiO2薄膜,然后再用自组装技术在薄膜表面沉积硬脂酸分子获得有机–无机复合薄膜。利用接触角测量仪和X射线粉末衍射仪研究了薄膜的润湿性和晶体结构,用微纳摩擦磨损试验机研究了薄膜在干摩擦条件下与轴承钢球往复滑动的摩擦学性能。结果发现,经硬脂酸改性后得到的双层薄膜呈现高疏水状态,对水接触角达135°具有优异的摩擦学性能。

人参的抗疲劳作用:一种治疗“Long COVID”的可行方案

在COVID-19爆发两年后,越来越多的COVID-19患者被“Long COVID”(LC)症状困扰。LC指COVID-19患者在最初症状出现后的四周后持续出现的症状、和/或延迟出现的长期并发症。持续疲劳是LC最常见的症状之一,严重降低患者的生活质量。被称为“中药之王”的人参在临床上具有抗疲劳作用。在这篇综述中,我们总结了人参提取物及其活性化合物的潜在抗疲劳机制,特别关注其在抗病毒、免疫重塑、内分泌系统调节和代谢方面的作用,提出人参是治疗LC特别是缓解疲劳症状的可行方案。

Functional monodisperse microspheres fabricated by solvothermal precipitation co-polymerization

Simultaneous achievement in high solid content and high microsphere yield is deemed a challenge in the fabrication of monodisperse microspheres by precipitation polymerization.We herein demonstrate that micro-sized monodisperse poly(methacrylic monomer-divinylbenzene)microspheres containing epoxy,lauyl,carboxyl and hydroxyl functions can be fabricated by solvothermal precipitation copolymerization at 20%(mass)monomer loading with over 94%microsphere yield.The morphology and porosity of the obtained particles can be readily tuned by cosolvent-acetonitrile binary solvents.Addition of a small amount of cosolvent that has similar solubility parameter to that of the functional monomer can significantly improve the monodispersity of the obtained microspheres.When tetrahydrofuran was used as the co-solvent,the surface area of the highly porous microspheres achieved higher than 400 m^(2)·g^(-1).Solvothermal precipitation co-polymerization can be expected in scale-up fabrication of various monodisperse functional microspheres free of any surfactant and additive.

Controllable blood–brain barrier(BBB)regulation based on gigahertz acoustic streaming

The blood–brain barrier(BBB)is a structural and functional barrier necessary for brain homeostasis,and it plays an important role in the realization of neural function and in protecting the brain from damage by circulating toxins and pathogens.However,the extremely dense BBB also severely limits the transport of molecules across it,which is a great hindrance to the diagnosis and treatment of central nervous system(CNS)diseases.This paper reports a new method for controllable opening of the BBB,based on the gigahertz acoustic streaming(AS)generated by a bulk acoustic wave resonant device.By adjusting the input power and working distance of the device,AS with tunable flow rate can be generated to disrupt tight junction proteins(TJs)between endothelial cells.The results obtained with this method show that the gigahertz AS promotes the penetration of dextran molecules with different molecular weights across the BBB.This work provides a new platform for studying the mechanical regulation of BBB by fluid shear forces and a new method for improving the efficiency of drug delivery.

Enhancing Embedding-Based Chinese Word Similarity Evaluation with Concepts and Synonyms Knowledge

Word similarity(WS)is a fundamental and critical task in natural language processing.Existing approaches to WS are mainly to calculate the similarity or relatedness of word pairs based on word embedding obtained by massive and high-quality corpus.However,it may suffer from poor performance for insufficient corpus in some specific fields,and cannot capture rich semantic and sentimental information.To address these above problems,we propose an enhancing embedding-based word similarity evaluation with character-word concepts and synonyms knowledge,namely EWS-CS model,which can provide extra semantic information to enhance word similarity evaluation.The core of our approach contains knowledge encoder and word encoder.In knowledge encoder,we incorporate the semantic knowledge extracted from knowledge resources,including character-word concepts,synonyms and sentiment lexicons,to obtain knowledge representation.Word encoder is to learn enhancing embedding-based word representation from pre-trained model and knowledge representation based on similarity task.Finally,compared with baseline models,the experiments on four similarity evaluation datasets validate the effectiveness of our EWS-CS model in WS task.

Case report: Treating postpartum SUI with acupuncture and Chinese herbal medicine

Background:Stress urinary incontinence(SUI),is the most common type of urinary incontinence affecting women.SUI has a significant impact on psychosocial functioning and quality of life.Biomedical treatments,such as surgery,often result in post-operative complications.In China,traditional Chinese medicine tends to be the treatment of choice for SUI.Case presentation:We present a 35-year-old patient who developed SUI following forceps delivery and was treated successfully with acupuncture and Chinese herbs.Traditional Chinese diagnosis,including channel and acupoint palpation revealed the patient had a syndrome pattern of liver/kidney deficiency,disordered bladder qi transformation,all of which lead to enuresis.Acupuncture,both body and scalp needling,were performed.Herbs were prescribed adjunctively.Conclusion:Traditional Chinese medicine modalities may be considered for treatment of SUI based on appropriate syndrome pattern assessment.

Health Assessment and Protection Countermeasures of Ecosystem of the Dajiu Lake in Shennongjia

The Dajiu Lake is an important subtropical alpine wetland in central China.In May of 2019,an ecological investigation was conducted on water quality and aquatic organisms(phytoplankton,zooplankton and zoobenthos)of the Dajiu Lake in Shennongjia forest region.The results showed that parameters of water quality in No.5 and No.9 sub lakes of the Dajiu Lake corresponded with standard of class II water of the Environmental Quality Standards for Surface Water(GB 3838-2002),while other sub lakes corresponded with standard of class III water.Diversity indexes of phytoplankton and zooplankton ranged from 2.0 to 3.0,and there were two families(Chironomidae and Libellulidae Rambur)of one phylum(Arthropoda)in zoobenthos.Comprehensive health index of entropy weight was used to evaluate water ecological status of the Dajiu Lake,and water quality of No.5,No.8 and No.9 sub lakes was in a healthy status,while other sub lakes were in sub-health status.Finally,corresponding countermeasures were proposed according to protection needs of the Dajiu Lake.

十堰市水库型饮用水水源地水资源评价

十堰市水环境监测中心每年逐月负责对辖区内水源地作水质监测，我们采用内梅罗污染指数（IP），分析2015至2017年重要水库型水源地的水质状况。用《地表水资源质量评价技术规程》（SL395-2007）对水库营养化进行了评价。结果表明，水源地水质是好的和比较好的，但总磷、总氮偏大问题不容忽视。