全文获取类型
收费全文 | 12659篇 |
免费 | 132篇 |
国内免费 | 12篇 |
专业分类
教育 | 8049篇 |
科学研究 | 2342篇 |
各国文化 | 93篇 |
体育 | 962篇 |
综合类 | 13篇 |
文化理论 | 83篇 |
信息传播 | 1261篇 |
出版年
2021年 | 114篇 |
2020年 | 155篇 |
2019年 | 255篇 |
2018年 | 313篇 |
2017年 | 320篇 |
2016年 | 260篇 |
2015年 | 202篇 |
2014年 | 259篇 |
2013年 | 2305篇 |
2012年 | 274篇 |
2011年 | 261篇 |
2010年 | 227篇 |
2009年 | 197篇 |
2008年 | 208篇 |
2007年 | 221篇 |
2006年 | 174篇 |
2005年 | 170篇 |
2004年 | 172篇 |
2003年 | 161篇 |
2002年 | 152篇 |
2001年 | 190篇 |
2000年 | 215篇 |
1999年 | 202篇 |
1998年 | 101篇 |
1997年 | 93篇 |
1996年 | 119篇 |
1995年 | 85篇 |
1994年 | 96篇 |
1993年 | 98篇 |
1992年 | 141篇 |
1991年 | 155篇 |
1990年 | 172篇 |
1989年 | 177篇 |
1988年 | 137篇 |
1987年 | 118篇 |
1986年 | 173篇 |
1985年 | 176篇 |
1984年 | 147篇 |
1983年 | 139篇 |
1982年 | 122篇 |
1981年 | 103篇 |
1980年 | 99篇 |
1979年 | 145篇 |
1978年 | 124篇 |
1977年 | 109篇 |
1976年 | 105篇 |
1975年 | 83篇 |
1974年 | 104篇 |
1973年 | 88篇 |
1971年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 60 毫秒
1.
Fadhaa A. Ghafil Bassim I. Mohammad Hussain S. Al-Janabi Najah R. Hadi Hayder A. Al-Aubaidy 《Indian journal of clinical biochemistry : IJCB》2021,36(1):81
Genetic variation in the angiotensin II type 1 receptor (AT1R) has an important effect on the outcome of acute coronary syndrome (ACS) initiated treatment with captopril. This study aims to investigate the impact of genetic polymorphism of AT1R (rs5186 and rs275651) on the ACS outcome in Iraqi patients treated with captopril. A total of 250 Iraqi individuals with ACS were included in this case—control study and they were divided into two study groups; Study group 1 included 125 participants who were prescribed captopril, 25 mg twice daily and study group 2 included 125 participants who received no captopril as part of their ACS treatment (control study). The AT1R gene (rs5186) CC genotype was found to be associated with ST-elevation myocardial infarction (STEMI) (Odd’s ratio (O.R) = 1.2, P = 0.7), while AC was associated with Non-ST-elevation myocardial infarction (NSTEMI) and unstable angina (UA) (O.R = 1.2, P = 0.8). AC genotype is more prone to have Percutaneous coronary intervention (PCI) after ACS attack (O.R = 1.2, P = 0.6). CC genotype had a risk to get less improvement (O.R = 1.6, P = 0.5), so might require higher doses of captopril during acute coronary insult. The AT1R gene (rs275651) AA genotype was associated with UA (O.R = 1.3, P = 0.9). AA and AT genotypes were more prone to have PCI after ACS attack (O.R = 3.9 P = 0.2, O.R = 3.5, P = 0.3 respectively) and thus requiring higher doses of captopril. We conclude that the AT1R rs5186, rs275651 genetic polymorphisms might partially affect the clinical outcome of ACS patients treated with captopril and might have captopril resistance which requires higher doses. 相似文献
2.
Harry F. Dorrell Joseph M. Moore Mark F. Smith Thomas I. Gee 《Journal of sports sciences》2019,37(1):67-73
This study investigated the validity and reliability of the GymAware PowerTool (GPT). Thirteen resistance trained participants completed three visits, consisting of three repetitions of free-weight back squat, bench press, deadlift (80% one repetition maximum), and countermovement jump. Bar displacement, peak and mean velocity, peak and mean force, and jump height were calculated using the GPT, a three-dimensional motion capture system (Motion Analysis Corporation; 150 Hz), and a force plate (Kistler; 1500 Hz). Least products regression were used to compare agreeability between devices. A within-trial one-way ANOVA, typical error (TE; %), and smallest worthwhile change (SWC) were used to assess reliability. Regression analysis resulted in R2 values of >0.85 for all variables excluding deadlift mean velocity (R2 = 0.54–0.69). Significant differences were observed between visits 3-2 for bench press bar displacement (0.395 ± 0.055 m; 0.383 ± 0.053 m), and deadlift bar displacement (0.557 ± 0.034 m; 0.568 ± 0.034 m). No other significant differences were found. Low to moderate TE (0.6–8.8%) were found for all variables, with SWC ranging 1.7–7.4%. The data provides evidence that the GPT can be used to measure kinetic and kinematic outputs, however, care should be taken when monitoring deadlift performance. 相似文献
3.
Thomas H. Champney 《Anatomical sciences education》2019,12(4):432-434
The value that willed body donors provide to medical education is priceless. Their precious gift helps to teach anatomy, spatial relationships between morphological structures, anatomical variation, and professionalism to medical students in a way that plastic models, podcasts, and lectures cannot. They are also an important resource for medical research and a wide variety of postgraduate training opportunities. While many body donation programs throughout the world are nonprofit organizations, there are body donation companies in the United States that sell donors for-profit. These “body brokers” have accumulated large profits from this business. It is incongruous that others would profit from such a priceless, freely donated gift. To prevent this incongruity, it is proposed that the international anatomical community develop a normative culture (a bioethos) for body donation programs. This would involve the conscious and systematic development of ethical principles for the day-to-day policies and practices of institutions that collect and use human bodies. With the development of this bioethos, a cultural shift in how donors are treated would occur and, over time, this would become the normal practice. These principles would become fundamental and foundational for the procurement and use of priceless human tissues. 相似文献
4.
5.
6.
7.
8.
We analyse the evolution of the slope (critical speed) and the y-intercept (anaerobic distance capacity) of the linear distance-time relationship over a century of Olympic running performances. The distance-time relationship of each Olympic Games (1920-2004) was plotted using the performances in the 800-, 1500- and 5000-m track events. Values for critical speed and anaerobic distance capacity were determined by linear modelling. Mean performances for the 800, 1500 and 5000 m were 104.9 +/- 1.5 s (1.4%), 217.2 +/- 2.8 s (1.3%) and 808.9 +/- 18.4 s (2.3%), respectively. Critical speed improved during the first three-quarters of the twentieth century to reach a plateau in 1984. This is in accordance with the literature (Peronnet & Thibault, 1989) and suggests that "human aerobic endurance" has improved within the century (+13.4%) and tends to stabilize. Anaerobic distance capacity was highly variable over the century (coefficient of variation = 9.4%) and did not show a linear improvement over the years as has previously been suggested (Peronnet & Thibault, 1989). This could be due to an artefact in the application of the two-parameter model to only three Olympic performances. A limitation to the use of this linear mathematical model to fit physiological data may have been demonstrated. 相似文献
9.
10.