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1.
The clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)is widely used for targeted genomic and epigenomic modifications and imaging in cells and organisms,and holds tremendous promise in clinical applications.The efficiency and accuracy of the technology are partly determined by the target binding affinity and residence time of Cas9-single-guide RNA(sgRNA)at a given site.However,little attention has been paid to the effect of target binding affinity and residence duration on the repair of Cas9-induced DNA double-strand breaks(DSBs).We propose that the choice of DSB repair pathway may be altered by variation in the binding affinity and residence duration of Cas9-sgRNA at the cleaved target,contributing to significantly heterogeneous mutations in CRISPR/Cas9 genome editing.Here,we discuss the effect of Cas9-sgRNA target binding and residence on the choice of DSB repair pathway in CRISPR/Cas9 genome editing,and the opportunity this presents to optimize Cas9-based technology.  相似文献   

2.
Since it was first recognized in bacteria and archaea as a mechanism for innate viral immunity in the early 2010 s,clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas) has rapidly been developed into a robust, multifunctional genome editing tool with many uses. Following the discovery of the initial CRISPR/Cas-based system, the technology has been advanced to facilitate a multitude of different functions. These include development as a base editor, prime editor, epigenetic editor, and CRISPR interference(CRISPRi) and CRISPR activator(CRISPRa) gene regulators. It can also be used for chromatin and RNA targeting and imaging. Its applications have proved revolutionary across numerous biological fields, especially in biomedical and agricultural improvement. As a diagnostic tool, CRISPR has been developed to aid the detection and screening of both human and plant diseases, and has even been applied during the current coronavirus disease 2019(COVID-19) pandemic. CRISPR/Cas is also being trialed as a new form of gene therapy for treating various human diseases, including cancers, and has aided drug development. In terms of agricultural breeding, precise targeting of biological pathways via CRISPR/Cas has been key to regulating molecular biosynthesis and allowing modification of proteins, starch, oil, and other functional components for crop improvement. Adding to this, CRISPR/Cas has been shown capable of significantly enhancing both plant tolerance to environmental stresses and overall crop yield via the targeting of various agronomically important gene regulators. Looking to the future, increasing the efficiency and precision of CRISPR/Cas delivery systems and limiting off-target activity are two major challenges for wider application of the technology. This review provides an in-depth overview of current CRISPR development, including the advantages and disadvantages of the technology,recent applications, and future considerations.  相似文献   

3.
Generation of mutants with clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)is commonly carried out in fish species by co-injecting a mixture of Cas9 messenger RNA(mRNA)or protein and transcribed guide RNA(gRNA).However,the appropriate expression system to produce functional gRNAs in fish embryos and cells is rarely present.In this study,we employed a poly-transfer RNA(tRNA)-gRNA(PTG)system driven by cytomegalovirus(CMV)promoter to target the medaka(Oryzias latipes)endogenous gene tyrosinase(tyr)or paired box 6.1(pax6.1)and illustrated its function in a medaka cell line and embryos.The PTG system was combined with the CRISPR/Cas9 system under high levels of promoter to successfully induce gene editing in medaka.This is a valuable step forward in potential application of the CRISPR/Cas9 system in medaka and other teleosts.  相似文献   

4.
以猪瘦肉与大豆粉、花生粉为原料,在添加剂上主要以葡萄糖和维生素C作为发色剂制成了营养保健型香肠,与传统的香肠相比,富有营养性和保健性,其适口性与出品率都有很大提高.  相似文献   

5.
1980年代的文学,在四个方面对整个新时期文学作了奠基:价值观上,经历了从人道主义大写的人到存在主义小写的人的探索,颠覆了"当代文学"的"政治文学"体系;方法论上,经历了从本质的人到现象的人、从古典思维到现代思维的革命,建立了新的艺术叙事体系;体制论上,经历了从体制的人到市民的人的嬗变,实现了作家队伍的非体制化与文学形象市民人格重建;传播论上,实现了从文学的人与传媒的人的变异,实现了从文学选择到传媒选择,勃起新的文学-传媒体系。在此意义上理解,80年代文学是异于前此"政治文学"的新时期、新世纪文学的逻辑起点。  相似文献   

6.
关于台湾地区和韩国民主化研究述评   总被引:2,自引:0,他引:2  
简要介绍和评论海内外学界关于台湾地区和韩国民主化的已有研究文献。总结了四种研究范式,评述了9位学者的研究成果,同时指出了已有研究文献存在的不足,旨在提供给国内学者进一步研究台湾地区和韩国民主化的基础。  相似文献   

7.
学习型课堂教学是以“学习型组织”理论为基础,以系统思考、团队学习、互动对话为基本特征的开放式、探究式的教学活动,它不仅符合我国教学改革的实际,使高校学课程教学与新的九年制义务教育《语课程标准》有效地衔接,焕发出学课程“人本主义”教学观的勃勃生机,而且能够促使师生破除封闭式的心智模式、构建未来学习型社会所需要的“自我发展”意识。  相似文献   

8.
季羡林以中国考据学、德国民俗学、民间文学和其他学术研究为基础,从比较文学思想的形成到影响研究的实践,从比较文学中国学派的倡导到立足于东方文学的具有中国特色的比较文化研究,从比较文学研究到比较文化研究,在近60年的理论探索与学术实践中,形成了完整的、系统的学术思想体系。季羡林堪称中国比较文学研究的泰斗。  相似文献   

9.
中国古代官员休假制度从西汉开始定型,当时人称之为"休沐".休沐制度保证了官员有一定的空暇时间去做各种事情,也为汉唐官员们进行文学活动提供了时间上的保证,从而给文学提供了一种有助发展的可能性.然具体到各个朝代,此制度对文学发展所起的作用又有所区别.  相似文献   

10.
乌克兰民族文化的起源可以追溯到东斯拉夫部落时期。基辅罗斯以来的一千年的乌克兰文学可分三个时期 ,即古代文学 (9— 18世纪 ) ,近代文学 (18— 2 0世纪 )和现当代文学 (2 0世纪至苏联解体 )。  相似文献   

11.
In this study we examined how good and weak students of literature interact with short literary stories. We focused on differences in the use of cognitive and affective reading activities, and in the extent to which good and weak students adapt their activities to (parts of) the story they are reading. 19 Dutch tenth-grade students from 8 classes participated in the study, of whom 10 were known to be good students of literature and 9 were known as weak literature students. Each student read five literary stories under think aloud conditions. The stories were presented segment by segment on a computer screen. Students responses were transcribed, segmented and coded. Analysis of variance was applied to the data to test the diffrences between good and weak students.  相似文献   

12.
近年来少数民族地区政府极少运用文学作为促进旅游业的手段,文学市场的吊诡性,才智和资金门槛较高等固然是重要因素,但最根本的是制度建设上没有适应计划体制向计划与市场混合体制的变化,基于此,提出文学与促进民族地区旅游业制度桥梁的若干做法,以期进一步推动民族地区旅游业的发展。  相似文献   

13.
当代贵州文学作为一种区域性文学,在对外传播活动中存在“贵州符号”识别体系缺失、“纯文学”传播理念被大众消费意识疏离和“沉默的螺旋”效应引发自我否定三方面的问题。因此,采取积极的应对策略势在必行:建立贵州文学符号识别体系,倡导多元文学共同传播的理念,培养贵州本土优秀的评论队伍形成反“沉默的螺旋”效应。这对促进当代贵州文学发展并扩大其影响力具有实际的可行性。  相似文献   

14.
当今众多小说家以“9·11”事件为背景或题材进行创作,形成21世纪文学中一个独特的文学群类,即后“9·11”小说。此类小说从书写“9·11”事件及其带给人类的集体或个体悲剧性体验、创伤后心理、精神危机等问题,刻画“9·11”事件之后蔓延整个西方世界的焦虑与恐惧,谱写21世纪以来人类面对生存危机之全景图。  相似文献   

15.
大陆、台湾、香港(澳门)构成中国文学的三维空间,从文学自身的特性来说,是应该跨越意识形态和政治制度的。中国当代文学史,没有在正史篇章中提到台港文学,这一现象很值得深思。台港文学作为“五四”新文学的同源支系,有较高的社会价值和审美价值,应该在中国当代文学史中得到体现,此事关中华民族文化的完整性。  相似文献   

16.
文学生产本质上就是意识形态生产,当政治意识形态统治走向商业意识形态统治时,文学生产机制也相应变革,主要体现在以下三个方面:一、在文学背景上由一体化转向全球化;二、在生产方式上由体制化转向资本化;三、在传播机制上由纸质化转向网络化。  相似文献   

17.
本文从十个方面论述了中国古代文学教材中现有的问题,并对某些问题提出了自己的一些设想。这十个问题是:1、中国古代文学的名实不符;2、对古代文化的评价落后;3、把文学作品当作信史看待;4、情理分析的尺度欠妥;5、教材的结构杂乱;6、成就与特点混淆;7、对文学自身规律认识不够;8、对社会人生重视不够;9、教材的观点太死;10、文学史与作品选不配套。  相似文献   

18.
从文献学科结构、读者需求信息和文献利用情况、出版物市场情况和文献出版信息三方面分析了高等院校图书馆文献需求,以提高文献采访工作的针对性,最终形成文献价值和文献需要有机统一的文献体系。  相似文献   

19.
中国古代文学现行的教学体系由于受制于教材王朝分期法的影响,故不能很好地揭示古代文学自身的发展规律。作为教学主导者的教师,必须加强文体意识,建立以文体为中心的教学体系。这样,在现行教材为学生建立起王朝更选中的古代文学发展史的基础上,教师再为他们建立起以文体为钢绳、以风格特征和表现手法为主要内容的古代文学发展史,让学生多角度、多线索、多层次地认识古代文学变化发展的历史,领悟到古代文学纵深之处的精神内核和文化意蕴。  相似文献   

20.
从儒门六经之修订,到现当代社会史史料搜集,乡村社会文献整理,在中国已有两千余年之历史。自主体、类别、性质、特征等方面观,与传世典籍文献、官方档案文献并列而存在的民间文献包括乡村社会文献,是一个特定的文献系统。从历史文献学学科视域中审视正在迅速消失中的乡村社会历史文献,进而实现系统科学整理,是民族文献遗产保护的现实举措,是社会史研究的基础工程,也是历史文献学学科重建的重要课题。  相似文献   

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