全文获取类型
收费全文 | 595篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
教育 | 295篇 |
科学研究 | 264篇 |
各国文化 | 3篇 |
体育 | 2篇 |
文化理论 | 3篇 |
信息传播 | 35篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 19篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 36篇 |
2017年 | 27篇 |
2016年 | 29篇 |
2015年 | 34篇 |
2014年 | 32篇 |
2013年 | 59篇 |
2012年 | 18篇 |
2011年 | 22篇 |
2010年 | 26篇 |
2009年 | 29篇 |
2008年 | 24篇 |
2007年 | 19篇 |
2006年 | 33篇 |
2005年 | 22篇 |
2004年 | 14篇 |
2003年 | 25篇 |
2002年 | 11篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 12篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有602条查询结果,搜索用时 609 毫秒
591.
M. Prasad D. Rajarajeswari P. Aruna K. Ramalingam R. Viswakumar Nusrath Fathima Sandeep Kumar Vishwakarma Aleem Ahmed Khan 《Indian journal of clinical biochemistry : IJCB》2022,37(3):335
Essential hypertension (EH) is a multifactorial and complex disease with high rate of incidence and associated co-morbidities. Previous studies do not provide unanimous results for the risk of hypertension and association with Fok I genotype frequency and serum vitamin D levels. Hence, this study was undertaken to determine the status of Fok I vitamin D receptor (VDR) gene polymorphism along with vitamin D levels and blood pressure in patients with EH. Four hundred (200 controls and 200 cases of essential hypertension) participants from general Indian population were enrolled in this study. Peripheral blood samples were collected for genotyping Fok I-VDR gene polymorphism using PCR–RFLP method whereas 25-OH vitamin D levels in serum were quantified using high performance liquid chromatography (HPLC). Significantly reduced 25-OH vitamin D levels were observed in patients with EH (24.04 ± 8.62 vs 50.46 ± 15.46) compared to control subjects (p = 0.0001). Homozygous recessive genotype ‘ff’ frequency was increased by 8.06 fold (CI: 3.71–17.47, p = 0.0001) in patients with EH compared to dominant ‘FF’ genotype frequency. In conclusion, recessive ‘ff’ genotype frequency correlates with reduced serum vitamin D levels and results in significantly increased systolic and diastolic blood pressures leading to predisposition of EH. 相似文献
592.
593.
Chandana Das V. Senthil Kumar Sayantani Basak Surabhi Gupta Sunesh Kumar 《Indian journal of clinical biochemistry : IJCB》2000,15(1):60-62
A female patient who had two primary cancers was investigated. Biochemical analysis of patient's serum for different parameters
indicated an alteration in the metabolic process. Prognostically, the patient has shown favourable clinical features. 相似文献
594.
In this study, we demonstrate a new perspective on in vitro assessment method for evaluating quantum dot (QD) toxicity by using microfluidics technology. A new biomimetic approach, based on the flow exposure condition, was applied in order to characterize the cytotoxic potential of QD. In addition, the outcomes obtained from the flow exposure condition were compared to those of the static exposure condition. An in vitro cell array system was established that used an integrated multicompartmented microfluidic device to develop a sensitive flow exposure condition. QDs modified with cetyltrimethyl ammonium bromide∕trioctylphosphine oxide were used for the cytotoxicity assessment. The results suggested noticeable differences in the number of detached and deformed cells and the viability percentages between two different exposure conditions. The intracellular production of reactive oxygen species and release of cadmium were found to be the possible causes of QD-induced cytotoxicity, irrespective of the types of exposure condition. In contrast to the static exposure, the flow exposure apparently avoided the gravitational settling of particles and probably assisted in the homogeneous distribution of nanoparticles in the culture medium during exposure time. Moreover, the flow exposure condition resembled in vivo physiological conditions very closely, and thus, the flow exposure condition can offer potential advantages for nanotoxicity research. 相似文献
595.
Pradyumna Kumar Mishra A. Bhargava R. P. Punde N. Pathak P. Desikan A. Jain S. Varshney K. K. Maudar 《Indian journal of clinical biochemistry : IJCB》2010,25(2):158-163
The present study included three groups: (A) age and gender matched control (n=24) with no previous signs of M. tuberculosis
complex (MTBC) infection, (B) patients (n=28) diagnosed with gastro-intestinal TB (GITB), (C) patients (n=50) with clinical
and histo-pathological signs of GITB, but were culture and AFB negative. Real time assay performed using fluorescence resonance
energy transfer hybridization probes showed a positivity index of 36 % in group C, i.e. 18 were found reactive from the total
50 cases studied. In addition, immune characterization of these 18 cases showed depleted CD4+ count and increased levels of IFN-γ and TNF-α cytokines. No positive case was found in group A, while in group B, out of
total 28 cases studied 27 were found positive. A combinatorial diagnostic approach for rapid detection and characterization
of GITB might provide specific therapeutic strategies for prevention and treatment of the infection in future. 相似文献
596.
Sunil Kumar Nanda D. R. Suresh A. Vamseedhar K. Pratibha B. Arjun 《Indian journal of clinical biochemistry : IJCB》2010,25(2):213-216
Alkaptonuria, a rare inborn error of tyrosine metabolism, characterized by the absence of homogentisic acid oxidase results
in the accumulation of homogentisic acid in the body. Associated renal failure and cerebral infarction is rare and usually
occurs in the later stages of the disease. We report a 55-year-old male who presented, initially with features of stroke and
degenerative arthritis. He had pigmentation of sclerae, darkening of urine on long standing, abnormal renal profile, degenerative
arthritis and cerebral infarction. Alkaptonuria was suspected and biochemical tests confirmed mild renal impairment, homogentisic
acid in urine and homogentisic acid crystal was detected cytologically in urine sediment. Such a case of Alkaptonuric ochronosis
with cerebrovascular and renal complications have been rarely reported in the previous literature. 相似文献
597.
598.
599.
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
600.
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.