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81.
Qi WANG Xiaoxia SHEN Tian QIU Wei WU Lin LI Zhi'an WANG Huixia SHOU 《Journal of Zhejiang University. Science. B》2021,22(2):99
Nucleic acids in plant tissue lysates can be captured quickly by a cellulose filter paper and prepared for amplification after a quick purification.In this study,a published filter paper strip method was modified by sticking the filter paper on a polyvinyl chloride resin(PVC)sheet.This modified method is named EZ-D,for EASY DNA extraction.Compared with the original cetyl trimethylammonium bromide(CTAB)method,DNA extracted by EZ-D is more efficient in polymerase chain reaction(PCR)amplification due to the more stable performance of the EZ-D stick.The EZ-D method is also faster,easier,and cheaper.PCR analyses showed that DNA extracted from several types of plant tissues by EZ-D was appropriate for specific identification of biological samples.A regular PCR reaction can detect the EZ-D-extracted DNA template at concentration as low as 0.1 ng/μL.Evaluation of the EZ-D showed that DNA extracts could be successfully amplified by PCR reaction for DNA fragments up to 3000 bp in length and up to 80%in GC content.EZ-D was successfully used for DNA extraction from a variety of plant species and plant tissues.Moreover,when EZ-D was combined with the loop-mediated isothermal amplification(LAMP)method,DNA identification of biological samples could be achieved without the need for specialized equipment.As an optimized DNA purification method,EZ-D shows great advantages in application and can be used widely in laboratories where equipment is limited and rapid results are required. 相似文献
82.
基于地震反射波法超前预测系统的原理及主要技术手段,以栋梁坡隧道工程为实例,针对隧道复杂的地质条件,施工过程中将超前地质预报和地质素描调查相结合,先对隧道全段范围内地形、地层岩性等进行全面核查,然后结合核查结果运用地震反射波法预报掌子面前方的节理裂隙发育情况,围岩完整性等地质信息.开挖后验证情况与预测结果基本一致,为后续... 相似文献
83.
ABSTRACT The Colorado Reading to Ensure Academic Development Act requires grade-level attainment in literacy in English for students in grades K-3. Its practical outcome, however, has been to pressure schools with bilingual programs to shift their instructional language allocations towards more English in the early grades. Proposed rule revisions debated by the state Board of Education sought to facilitate testing in students’ language of instruction for those in bilingual programs. Analysis of written and verbal opposition to the proposed rule revisions demonstrates the persistence of insidious ethnoculturalist discourses opposing bilingual education as well as the cooptation of liberal multiculturalist discourses that, while framing bilingualism as an asset, argue that it is underdeveloped in bilingual programs that do not include English instruction from the outset. Given that bilingual instruction has demonstrated time and again that it benefits students acquiring English in schools, such new discursive turns pose a threat that must be recognized to fend off further legislative and regulatory attempts against bilingual education. 相似文献
84.
Feedback can play a vital role in fostering teacher self-efficacy. Social comparisons and feedback valence (positive vs. negative feedback) are assumed to have a large impact on self-efficacy. Therefore, how pre-service teachers perceive social comparisons and feedback valence in peer feedback and the extent to which pre-service teachers (bachelor/master students) and teacher trainers incorporate comments that can have an impact on self-efficacy into their peer feedback merit investigation. Two studies were conducted. The first showed that peer feedback consisting of a social comparison and with positive feedback valence resulted in greater willingness to improve and positive affect. The second study revealed that teacher trainers’ feedback was more specific, whereas bachelor students’ feedback contained more social comparisons than did master students’ and teacher trainers’. Future research and practical implications are discussed. 相似文献
85.
86.
目的:探讨ER、erbB-2和P53在胃癌表达及相关性。方法:取胃癌手术标本119例,SP免疫组织化学染色。结果:ER、erbB-2和P53在胃癌表达率分别为63.87%,75.51%和73.11%;三者同时阳性者31.93%;ER与P53同时阳性者37.82%;ER与erbB-2同时阳性者33.61%;ER在高分化组阳性率高于低分化组(P<0.05);而erbB-2和P53在低分化组阳性率高于高分化组。70岁以上组P53、ER和erbB-2表达率均较高。结论:ER、P53和erbB-2在胃癌中表达率与癌瘤分化程度相关。P53和erbB-2有相关性,而且它们是胃癌预后不良的指标。 相似文献
87.
以易制备的2-(1,2-亚乙/1,3-亚丙二硫)亚甲基-3-羰基丁酸1为原料,经与氯化亚砜的氯化反应后,与胺反应成功地以较好产率(40.5%-72.0%)合成重要的有机合成中间体2-(1,2-亚乙/1,3一亚丙二硫)亚甲基-3-羰基-N-芳(烷)基丁酰胺3. 相似文献
88.
Tong Chen Yue-ling Gu Jian-hua Yan Xiao-dong Li Sheng-yong Lu Hui-fen Dai Ke-fa Cen 《浙江大学学报(A卷英文版)》2008,9(9):1296-1303
Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) emissions in flue gas from two types of municipal solid waste incinerators (MSWIs) most commonly used in China were investigated in this study. The selected incinerators include two grate-type MSWIs: MSWI-A (350 t/d) and MSWI-B 050 t/d), and two fluidized bed MSWIs: MSWI-C (400 t/d) and MSWI-D (400 t/d), which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber (WS) as air pollutant control device (APCD). Results indicated that the emission concentration and the international toxic equivalents (I-TEQs) of the PCDD/Fs from the stacks were in the range of 1.210-10.273 ng/Nm^3 and 0.019-0.201 ng I-TEQ/Nm^3, respectively. They were greatly lower than the emission regulation standard of PCDD/Fs in China (1.0 ng I-TEQ/Nm^3). However, only the PCDD/Fs emission level from MSWI-C was below 0.1 ng I-TEQ/Nm^3. Although the homologue profiles were distinct, the contributions of the 2,3,7,8-subsituted congeners to the total I-TEQ were similar among all the investigated MSWIs. Two major 2,3,7,8-substituted congeners, 2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD, account for 47% and 9% (average values) of the total I-TEQ values, respectively. The correlation between PCDD/Fs levels and composition of flue gas was also discussed. 相似文献
89.
90.
地方高校实验教学示范中心建设的研究与实践 总被引:10,自引:10,他引:10
高等学校实验教学示范中心将引领我国高校实验室建设和实验教学改革的发展趋势,国家级实验教学示范中心建设被列为教育部本科教学质量工程之一,作为地方高校如何创建省级和国家级实验教学示范中心,文中提出了多出精品,创出特色的建设思路。 相似文献