Highly efficient CRISPR-SaKKH tools for plant multiplex cytosine base editing

Base editing, as an expanded clustered regularly interspaced short palindromic repeats(CRISPR)-Cas genome editing strategy, permits precise and irreversible nucleotide conversion. SaKKH, an efficient variant of a Cas9 ortholog from Staphylococcus aureus(SaCas9), is important in genome editing because it can edit sites with HHHAAT protospacer adjacent motif(PAM) that the canonical Streptococcus pyogenes Cas9(SpCas9) or its variants(e.g. xCas9, Cas9-NG) cannot. However, several technical parameters of SaKKH involved base editors have not been well defined and this uncertainty limits their application. We developed an effective multiplex cytosine base editor(SaKKHn-pBE) and showed that it recognized NNARRT, NNCRRT, NNGRGT, and NNTRGT PAMs. Based on 27 targets tested, we defined technical parameters of SaKKHn-pBE including the editing window, the preferred sequence context, and the mutation type. The editing efficiency was further improved by modification of the SaKKH sgRNA. These advances can be applied in future research and molecular breeding in rice and other plants.

Natural Languages Processing for Building Computer- based Learning Tools

This paper outlines a framework to use computer and natural language techniques for various levels of learners to learn foreign languages in Computer-based Learning environment.We propose some ideas for using the computer as a practical tool for learning foreign language where the most of courseware is generated automatically.We then describe how to build Computer-based Learning tools,discuss its effectiveness,and conclude with some possibilities using on-line resources.

Synergistically Toughening Effect of SiC Whiskers and Nanoparticles in Al_2O_3-based Composite Ceramic Cutting Tool Material

In recent decades, many additives with different characteristics have been applied to strengthen and toughen Al2O3-based ceramic cutting tool materials. Among them, SiC whiskers and SiC nanoparticles showed excellent performance in improving the material properties. While no attempts have been made to add SiC whiskers and SiC nanoparticles together into the ceramic matrix and the synergistically toughening effects of them have not been studied. An Al2O3-SiCw-SiC np advanced ceramic cutting tool material is fabricated by adding both one-dimensional SiC whiskers and zero-dimensional SiC nanoparticles into the Al2O3 matrix with an effective dispersing and mixing process. The composites with 25 vol% SiC whiskers and 25 vol% SiC nanoparticles alone are also investegated for comparison purposes. Results show that the Al2O3-SiCw-SiCnp composite with both 20 vo1% SiC whiskers and 5 vol% SiC nanoparticles additives have much improved mechanical properties. The flexural strength of Al2O3-SiCw-SiCnp is 730＋ 95 MPa and fracture toughness is 5.6 ± 0.6 MPa.m1/2. The toughening and strengthening mechanisms of SiC whiskers and nanoparticles are studied when they are added either individually or in combination. It is indicated that when SiC whiskers and nanoparticles are added together, the grains are further refined and homogenized, so that the microstructure and fracture mode ratio is modified. The SiC nanoparticles are found helpful to enhance the toughening effects of the SiC whiskers. The proposed research helps to enrich the types of ceramic cutting tool and is benefit to expand the application range of ceramic cutting tool.

Modeling Notch Wear of Ceramic Tool in High Speed Machining of Nickel-based Superalloy

On the basis of theoretical analyses and calculations of high speed continuous impact force and tool notch surface temperature acted upon by burr and serrated chip edge, a notch wear model of low stress value and temperature impact fatigue was established. Saw-tooth-shaped burr and fin-shaped chip edge continuously impacts the rake face and flank face at high speed and high fre-quency, which results in a V-shaped notch wear. An experiment was done to validate that the saw-tooth-shaped burr does affect the notch wear. This model can be utilized to solve reasonably many problems that cannot be explained by any other theoretical assumptions.

ECO-Case Based Reasoning Tool for Environmental Product Design

Case Based Reasoning(CBR)is one of the artificial intelligent methodologies that is widely used in problem solving by reusing the most similar previous experiences stored in the library.A framework of ECO-CBR for Life Cycle Assessment data collection has been used and the process was carried out using SolidWorks program.The practicality of the tool has been validated using case study,which then provides solution.The output enable researchers to determine forecast error and forecast accuracy,by valuing the calculation from Total Carbon Footprint,Energy Consumption,Air Acidification,and Water Eutrophication.ECO-CBR is able to assist designers in product design.Due to the limitation of environmental impact consideration in product sustainability,there is a demand to propose a tool that can assist designers to reduce environmental impact of product design at early stage.The model works as an essential guideline to lessen repeated mistakes in the product development process and help designers measure the risks before concluding ideal decisions.Minor errors that occur through the study showed that ECO-CBR is reliable to be implemented in order to find a better solution.

Pre and Post Effects Assessment of Marine Ranch Construction in Chlorophyll-a Concentration Using MODIS Data and a Web-Based Tool. A Case Study in Zhelin Bay, China

Chlorophyll-a (Chl-a) concentration in lakes can tell a lot about a lake’s water quality and ecosystem. It is a measure of the amount of algae growing in a waterbody and can be used to monitor the trophic condition of a waterbody. We studied the pre and post effects of marine ranch construction in Chl-a concentration in Zhelin Bay, Southern China using Normalized Difference Chlorophyll Index (NDCI) and a web-based tool (https://mapcoordinates.info/). We used 8 day composite MODIS image collections of 500 m resolution and randomly selected two stations to extract the chlorophyll-a concentration values through the web-based tool. We recorded the slight increase in NDCI values in all stations after the construction of marine ranch which is a good indicator of the marine organisms’ reproduction and survival.

NOTCH WEAR OF MACHINING NICKEL BASED ALLOYS WITH CERAMIC TOOLS

The performances of mixed ceramic and sialon ceramic tools in machining nickel based alloy are tested.The negative cutting edge inclination and small tool lead angle are recommended for reducing ceramic tool failure. So called“notching at depth of cut”is not actually at the depth of cutting line, but out of cutting area。 The real reason of notching is caused by shocking of “sawtooth”on sawtooth- shaped burr and fin- shaped edges of chip

城市绿色基础设施政策工具的系统综述和研究前沿分析

【目的】城市绿色基础设施政策工具是由政府主导实施的促进城市绿色基础设施建设的重要手段。【方法】以绿色基础设施政策工具为研究对象,借助Bibliometrix R Package软件和CiteSpace软件,以文本检索、计量分析、编码分类为研究线索,深入剖析了12项代表性城市绿色基础设施政策工具的发展历程,对比其发展历程、指标体系、绩效评估方式和政策管控路径的优势和劣势,探究绿色基础设施建设管理与生态系统服务目标有机结合的途径和方式。【结果】1)城市绿色基础设施政策工具的目标定位从解决单一雨水问题转向评估生态系统服务多重效益。2)政策指标初期包括植物、水系和土壤元素,后期逐步形成包括地表复层植被、地表蓝绿设施、建筑垂直绿化、建筑绿色屋顶项目元素,以及直接干预、动物介入管理元素的层级体系。3)城市绿色基础设施政策工具有强制约束土地利用的“一致性”和间接鼓励的“描述性”2种模式,结合了标准权重和绩效阈值2种互补的城市开发项目筛选机制,工具应用于规划、建设、管控、监测全周期过程。4)结合生态系统服务需求,校准城市绿色基础设施政策工具的绩效评估权重已成为迫切需求。【结论】城市绿色基础设施政策工具将成为应对全球问题和城市挑战的有力手段,揭示其管控落实过程的多元思路,可为城市绿色基础设施优化与完善提供政策指引和技术支持。

AlCrN系列刀具涂层的研究现状与展望

刀具涂层能够有效阻挡刀具材料与工件间的元素扩散,减少因摩擦产生的大量切削热,解决硬质合金刀具加工时面临的易磨损、寿命短等问题,近年来成为高速切削领域的研究热点,并得到快速发展.AlCrN涂层凭借优异的力学性能已被广泛应用,但在高速高载热负荷的切削环境下,涂层的抗氧化性能和耐磨性能还有待提高.因此,国内外研究者通过在AlCrN涂层中掺杂各种元素改善其服役性能.本研究分别介绍了Si和Ti掺杂对涂层微观结构、力学性能和抗氧化性能的影响,归纳了V和Mo掺杂自润滑涂层研究中的关键问题,分析了O掺杂对涂层性能的影响及其影响机理.最后,总结了兼具耐磨和抗氧化性能的高熵合金刀具涂层领域中亟待解决的关键难题以及未来的研究方向.

信息型政策工具如何促进中小企业持续创新——资源拼凑的中介效应与创新动力的调节效应

在创新驱动发展战略和数字化转型深入推进的背景下,政府部门出台了一系列信息型政策工具来促进中小企业创新发展,但是,信息型政策工具是否以及如何促进企业持续创新,学界对此研究较少。以国内446家科技中小企业为研究对象,实证检验信息型政策工具对中小企业持续创新的影响机理。结果表明:信息型政策工具会对中小企业资源拼凑(探索式资源拼凑、利用式资源拼凑)及企业持续创新产生显著正向影响;资源拼凑在信息型政策工具与中小企业持续创新之间发挥部分中介作用,且相较于利用式资源拼凑,探索式资源拼凑的中介效应更强;创新动力显著正向调节资源拼凑与中小企业持续创新之间的关系,且创新动力在利用式资源拼凑与中小企业持续创新之间的调节作用更强。

慢性阻塞性肺疾病相关性疲劳评估工具的系统评价

目的对慢性阻塞性肺疾病(COPD)相关性疲劳特异性评估工具进行系统评价,为今后临床选择和开发高质量工具提供依据。方法检索PubMed、Web of Science、CINAHL、Embase、Cochrane Library、中国生物医学文献数据库(CBM)、中国知网(CNKI)、万方数据库和维普数据库中,所有关于COPD相关性疲劳特异性评估工具相关研究。检索时限为建库至2023年5月22日。使用“基于共识选择健康测量工具的标准(COSMIN)指南”对纳入工具的方法学及测量属性特征进行系统评价,综合评定证据等级并形成推荐意见。结果共纳入8个COPD相关性疲劳特异性评估量表,曼彻斯特COPD疲劳量表(MCFS)为A级推荐,修订版慢性病治疗功能评估—疲劳量表(MFACIT-F)、疲劳影响量表(FIS-25)、COPD和哮喘疲劳量表(CAFS)、疲劳评估工具(TFT)、中文修订版曼彻斯特COPD疲劳量表(MCFS-C)、中文修订版疲劳影响量表(FIS-C)、疲劳严重程度量表(FSS)为B级推荐。结论MCFS量表有高等证据支持内容效度、内部一致性和稳定性、中等证据支持结构效度,故暂被推荐使用,但适合我国的COPD相关性疲劳特异性评估工具仍有待进一步开发。

基于知识图谱的整硬合金铣刀产品知识库构建与应用

由于整体硬质合金铣刀产品数据的内容繁杂、多源异构、表现形式多样,因此需要对其进行知识的组织管理,实现知识集成、共享与重用。首先,对该类刀具产品所含的知识即结构分类信息、切削参数信息、产品全生命周期信息及信息间内在关联进行分析。其次,引入知识图谱构建技术与本体建模理论,通过建立知识本体模型,构建知识图谱。最后,设计并实现整体硬质合金铣刀产品知识库,进行实例验证。便于企业需求用户快速了解及获取刀具产品的切削用量、工艺环境等信息;工艺设计人员选用合理刀具以制定最优加工方案,提升加工效率和保障加工质量。

技能强国背景下省域技能型社会建设的政策分析——以浙江省15份政策文本为例

建设技能型社会是推进中国式现代化、提升国家竞争力的必然要求。选取浙江省技能型社会建设政策作为研究对象,依照麦克唐纳尔和艾莫尔的政策工具分析框架,对15份政策文本进行计量与内容分析。研究发现,浙江省技能型社会建设政策存在命令型政策工具使用过溢、政策弹性不足,激励型政策工具规划不足、执行主体动力受限,能力建设型政策工具适配性不够、未能弥合供需裂缝,制度变迁型政策工具选择偏少、协同效益产出不高等问题。为更好地建设技能型社会,省域层面的整体政策设计应兼顾系统性与区域创新,政策工具选择应增强匹配性与功能协同,激励政策运用应关注多主体与长期效应,保障体系建设应着眼融通性与软硬并重。

老龄化进程中地方政府居家养老服务政策工具演进逻辑——基于南京市政策文本的分析

在人口老龄化加剧的过程中,地方政府出台了一系列居家养老服务政策,政策工具不断演进。本研究运用政策文本分析方法,分析南京市居家养老服务政策的发文量以及政策工具的种类、数量和使用情况,探讨居家养老服务政策工具的演进逻辑。研究发现,居家养老服务政策工具可分为供给型、环境型和需求型三种,它们在时间维度上呈现出互适性的动态特征。基于财政压力与资源调配能力、政府部门内部压力与竞争以及社会公众需求的推动,居家养老服务政策工具的演进逻辑表现为:从家庭和政府主导到包容多元主体、从硬性法规到柔性措施选择、从传统科层制流程到数字服务的智能化运行。

情境模拟教学设计及课程开发评价工具的效度验证

目的 验证《情境模拟教学设计及课程开发评价工具》用于评价住院医师规范化培训指导医师情境模拟教学设计和课程开发能力的效度证据。方法 由2022年上海市住院医师规范化培训指导医师情境模拟教学能力比赛专家小组共同开发了《情境模拟教学设计及课程开发评价工具》,采用Messick效度验证框架对54份参赛教案的评分进行效度验证。结果 本研究收集了基于反应过程、内部结构、与其他变量的关系和后果的效度证据。结论 《情境模拟教学设计及课程开发评价工具》是一种可靠的评价住院医师规范化培训指导医师情境模拟教学设计和课程开发能力的工具。本研究对教案得分细项进行分析,提示未来情境模拟师资培训的重点方向。

全球肿瘤相关性血栓栓塞症风险评估工具的循证研究

目的 基于循证方法对全球肿瘤相关性血栓栓塞症风险评估工具进行评价,以期为构建我国特异性评估工具提供方法学参考与循证依据。方法 全面检索中国知网、万方数据库、维普网、中国生物医学文献数据库、PubMed及Embase 6个数据库和NCCN、ASCO及ESMO等学会网站,检索截止时间为2022年6月30日,并于2023年1月补充检索。对纳入的风险评估工具,定性描述分析其基本特性与方法学质量,重点对比各评估工具评价维度、工具性能、风险分层能力等关键要素。结果 研究共纳入14个风险评估工具,其研究样本量为208~18 956例,受试者平均年龄分布在53.1~74.0岁;适用人群涵盖门诊肿瘤患者、淋巴瘤患者及多发性骨髓瘤患者等。工具中身体质量指数、静脉血栓栓塞症既往史和肿瘤部位是常见的预测因子。所有工具均进行了方法学验证,其中9个以权重评分的方式呈现。同时进行了特异性、敏感性、阴性预测值、阳性预测值和曲线下面积或C统计量分析的工具仅7个。结论 现有工具构建偏倚风险较高,工具验证结果异质性较大,整体方法学质量有待提高,风险分层能力也有待考究,在我国临床实践中仍存在一定局限性。

儿童青少年慢性疾病用药自我管理评估工具的循证评价

目的:系统评价儿童青少年慢性疾病(慢病)用药自我管理评价工具的现状,为保障儿童青少年慢病患者的治疗效果提供循证医学证据。方法:系统检索PubMed、EMBase、the Cochrane Library、CBM、CNKI、维普和万方等国内外数据库,检索时限为建库至2023年3月,纳入儿童慢性疾病用药自我管理评价工具的文献。采用描述性方法对结果进行分析。结果:针对疾病类型共纳入16篇文献,43.75%(7/16)为糖尿病自我管理量表、18.75%(3/16)为儿童哮喘自我管理量表、12.50%(2/16)为青少年通用自我管理量表、6.25%(1/16)为儿童胰岛素治疗自我管理量表、6.25%(1/16)为儿童癫痫用药自我管理量表。25.00%(4/16)量表设计有理论依据和中文版。纳入的量表领域为1~8(3.69±1.74)个,量表条目为14~52(27.81±10.24)个。纳入量表中,用药管理条目缺乏,主要包括遵医嘱用药、调整药物剂量、药物不良反应、服药的方便性和服药责任感等内容。结论:目前我国缺乏自主开发的儿童青少年慢性疾病用药管理评价工具,评价工具角度单一,缺乏个人、家庭、医疗系统和社会不同层面的整合,建议开发与验证适用于我国儿童青少年慢性疾病患者的自我管理评价工具,为临床实施自我管理计划提供参考。

OBE教育理念下的外语课堂形成性评价:理论与实践构念

OBE(Outcome-Based Education)教育理念强调以学生为中心、以产出为导向、注重教学和学习的持续改进。它不仅关注学习成果,还关注如何评价学习成果。课堂形成性评价是连接“教”与“学”的有效方式,在学业评价范式变革中发挥着越来越重要的作用。本文以分析课堂形成性评价的理论框架、实施工具与方法为基础,对外语课堂形成性评价的理论和实践构念进行系统阐述,对目前存在的问题提出对策和建议,从而为促进外语课堂形成性评价研究和实践提供启示。

自动化文献筛选工具在系统评价中的应用

系统评价是循证医学研究工作的基础,高质量的系统评价代表了评估治疗效果的最高证据水平。传统系统评价主要由人工完成,然而海量文献的阅读与筛选工作需花费临床研究者大量精力与时间,效率较低,无法适应快速决策的需求。本文对现有的用于系统评价文献筛选的自动化工具进行系统整理,分析其各自性能、特点和使用情况,以了解该领域发展现状,为相关研究和应用提供参考。

星基ADS-B系统空天链路的建模与仿真

星基广播式自动相关监视(ADS-B,automatic dependent surveillance-broadcast)系统是一种新型的航空器监视技术,在未来空中交通管理系统中具有广阔的应用前景。为了深入研究星基ADS-B系统中航空器到卫星的空天链路通信性能,将专业软件Matlab和STK(system tool kit)有效联合,构建符合国际标准的星基ADS-B空天链路完整模型;通过离散事件动态交互模拟ADS-B消息的发送与接收全过程,最后统计得出体现星基ADS-B空天链路通信性能的消息识别概率(POI,possibility of identify)、消息检测概率(POD,possibility of detective)、信号接收功率、信号冲突概率、卫星覆盖范围等指标。仿真结果表明,随着区域内航空器数量上升,POI、POD下降,消息冲突概率上升。