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541.
Molecular combing and flow-induced stretching are the most commonly used methods to immobilize and stretch DNA molecules. While both approaches require functionalization steps for the substrate surface and the molecules, conventionally the former does not take advantage of, as the latter, the versatility of microfluidics regarding robustness, buffer exchange capability, and molecule manipulation using external forces for single molecule studies. Here, we demonstrate a simple one-step combing process involving only low-pressure oxygen (O2) plasma modified polysilsesquioxane (PSQ) polymer layer to facilitate both room temperature microfluidic device bonding and immobilization of stretched single DNA molecules without molecular functionalization step. Atomic force microscopy and Kelvin probe force microscopy experiments revealed a significant increase in surface roughness and surface potential on low-pressure O2 plasma treated PSQ, in contrast to that with high-pressure O2 plasma treatment, which are proposed to be responsible for enabling effective DNA immobilization. We further demonstrate the use of our platform to observe DNA-RNA polymerase complexes and cancer drug cisplatin induced DNA condensation using wide-field fluorescence imaging. 相似文献
542.
Mirna E. Turcios Naresh Kumar Agarwal Linda Watkins 《The Journal of Academic Librarianship》2014,40(5):473-479
There is an extensive amount of Library and Information Science (LIS) writing produced each year. While there is general awareness regarding the variety of journal literature, there is no certainty on the percentage of the collection that we can call research. This project is an important first step in answering the question. A content analysis of the LIS academic/scholarly journals at the Simmons College Library was conducted. The research level collection of LIS literature makes the library an ideal candidate for this study. The latest issue of each journal subscribed to for fiscal year 2012–2013 containing academic/scholarly content was analyzed. Each article was analyzed to determine: 1) if it was research or non-research, 2) the method used to collect data for the study in the article, and 3) the subject terms or keywords associated with the article. 105 journal titles were identified out of 177 periodicals. In the 1880 articles analyzed from these, 16% qualified as research. Surveys were found to be the most popular research method used. This study will benefit students, faculty, and staff with research requirements as well as librarians who guide patrons through a search for research literature. 相似文献
543.
B.T. Sampath Kumar K.S. Manoj Kumar 《International Information and Library Review》2012,44(4):202-211
This study investigates the decay and half-life of online citations cited in four open access journals published between 2000 and 2009. A total of 1158 online citations cited in 1086 research articles published in two science and social science journals spanning a period of 10 years (2000–2009) were extracted. Study found that 24.58% (267 out of 1086) of articles had online citations and these articles contained a substantially very less number of online citations (2.98%) compared to previous study results. 30.56% (26% in Science and 52.73% in Social Science) of online citations were not accessible and remaining 69.44% of online citations were still accessible. The ‘HTTP 404 error message-page not found’ was the overwhelming message encountered and represented 67.79% of all HTTP message. Domains associated with .ac and .net had higher successful access rates while .org and .com/.co had lowest successful access rates. The half-life of online citations was computed to be approximately 11.5 years and 9.07 years in Science and Social science journal articles respectively. 相似文献
544.
Bandana Kumari Krishnan Hajela Asgar Ali Abhay Kumar Sharma Rajesh Kumar Yadav Alok Ranjan Rathish Nair Shreekant Bharti Satish Dipankar Prabhat Kumar Singh Sadhana Sharma 《Indian journal of clinical biochemistry : IJCB》2023,38(1):102
IntroductionDetecting low viral load has been a challenge in this pandemic, which has led to its escalated transmission. Complement activation has been implicated in pathogenesis of Covid-19 infection. Thus, evaluation of complement activation in suspected Covid-19 infection may help to detect infection and limit false negative cases thus limiting transmission of infection. We speculate that measuring C4b, produced from an activated complement system due to the presence of Covid-19 may help in its detection, even when the viral titers are low.MethodsPlasma C4b levels of symptomatic RT-PCR positive patients (cases, n = 40); symptomatic RT-PCR negative patients (n = 35) and asymptomatic RT-PCR negative controls (n = 40) were evaluated. Plasma C5b-9, IL-6, D-dimer and C1-Inhibitor (C1-INH) were also measured in cases and controls. ELISA kits were used for all measurements. Statistical analyses were carried out using Stata, version 12 (Stata Corp., Texas, USA).ResultsC4b levels were found to be significantly increased in RT-PCR positive patients as compared to asymptomatic RT-PCR negative controls. RT-PCR negative but symptomatic patients still showed increased C4b levels. The significantly higher levels of C4b in cases with a cut-off value of ≥ 116 ng/ml with optimum sensitivity and specificity of 80% and 52% respectively is indicative of its possible use as an adjunct marker. Increased levels of D-dimer, IL6, along with decreased levels of C1-INH were found in cases compared to controls. Whereas, C5b-9 levels were not significantly raised in cases.ConclusionsThe results of our study suggests that plasma C4b may help to detect infection in false negative cases of RT-PCR that escape detection owing to low viral load. However, to confirm it a large-scale study is needed.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12291-022-01033-z. 相似文献
545.
Debadutta Kumar Panda 《Performance Improvement Quarterly》2014,27(1):5-32
This study measures the impact of managerial networks on firm growth. A simple random technique was used to select 680 firms and a top manager from each firm. A structured pretested questionnaire was designed to collect information. The sample firms were further stratified into subgroups based on size of firms (small firms and large) and business sectors (manufacturing and service firms). Statistical tests and multivariate models were formulated for data analysis. The managerial networking intensity was found to be a positive and significant determinant of firm growth regardless of type of business and size. Managerial networking with buying firms or buyers, competitors, and government officials were found positive and statistical significant determinants of firm growth. 相似文献
546.
Virginia L. Byrne Juana Hollingsworth Priya C. Kumar 《British journal of educational technology : journal of the Council for Educational Technology》2023,54(6):1636-1652
Postsecondary institutions have a legal responsibility to ensure that students have access to a safe learning environment. While institutions adopt policies and hire administrators to protect students from harm, many are underprepared to support students when these harmful incidents happen online. This is of increased concern now that online aggression is pervasive across universities worldwide. While faculty, administrators and students agree that online aggression is a significant issue and that institutions ought to provide prevention and response services, there is concern that these efforts might violate privacy norms. We used the theory of privacy as contextual integrity (CI) to explore the tensions that postsecondary students and staff perceive regarding student privacy when responding to incidents of online aggression. To do so, we conducted focus groups with undergraduate students and student affairs administrators from a Historically Black College and University (HBCU) in the Mid-Atlantic USA. Our analysis surfaced three considerations that inform students' and staff's decision to report an incident of online aggression: their closeness to the person making the post, their perception of the online post content as a real threat and their knowledge of an authority figure who could help resolve the situation. We used CI theory to explain how these considerations can inform institutional policy, practice and future research.
Practitioner notes
What is already known about this topic
- Online aggression is a pervasive issue at postsecondary institutions worldwide that can contribute to psychological, academic and developmental issues.
- Postsecondary students and staff are unsure of how to respond to incidents of online aggression.
- There is a gap in policies and procedures for responding to online aggression at postsecondary institutions.
What this paper adds
- A novel use of Nissenbaum's (2010) theory of contextual integrity to understand students' and staff's perceptions of privacy.
- Students' and staff's decisions to intervene or report an online aggression incident are determined by their relationship to the perpetrator, the severity of the social media post and their knowledge of who to tell on campus.
- Students and staff are reluctant to inform the police out of fear of violence against the perpetrator.
Implications for practice and/or policy
- Raise awareness about responding to online aggression incidents.
- Implement online bystander intervention training programs to increase awareness and self-efficacy to intervene in unclear situations.
- Develop clear policies regarding online aggression, as well as a trustworthy procedure for how to respond.
547.
Gumbheer Chandra Prakash Khedo Kavi Kumar Bungaleea Anjali 《Education and Information Technologies》2022,27(6):7491-7517
Education and Information Technologies - Due to the outbreak of COVID 19, digital learning has become the most efficient learning and teaching technique adopted across the world. The pervasiveness... 相似文献
548.
Sanjib Kumar Ghosh 《Anatomical sciences education》2022,15(6):1103-1119
The Covid-19 pandemic stipulated adoption of unfamiliar strategies for delivering anatomy education in online mode. The factors which determine education strategies are variable across geographical regions. It was perceived that an overview of education strategies around the globe would be useful for anatomists. Hence this narrative review was undertaken to collate observations from different geographical regions pertaining to education strategies adopted during the pandemic. Data relevant to the topic of study were extracted from 12 articles that were selected from an initial pool of 317 articles based on search criteria set for the review. Subtle differences in core education strategies implied that baseline response from anatomists was similar across regions. It was evident that online digital tools were key elements of education strategies adopted by educators for delivering online anatomy classes across the globe. Interestingly, a considerable gap in terms of number and variety of online tools used for anatomy education (those requiring commercial purchase) was noted between economically developed and developing regions. This may have an impact on learning outcome for students and may even lead to variations in anatomical knowledge by regions. It was observed that offline human dissection sessions were incorporated into online practical classes in one region as positive cases showed a declining trend. This positive development is worth emulating elsewhere based on cautious assessment of prevailing situation. From a broad perspective timely introduction of education strategies ensured delivery of anatomy education during the pandemic and gave an evolved outlook to the fabric of anatomy education. 相似文献