全文获取类型
收费全文 | 761篇 |
免费 | 185篇 |
国内免费 | 39篇 |
出版年
2024年 | 14篇 |
2023年 | 44篇 |
2022年 | 71篇 |
2021年 | 61篇 |
2020年 | 39篇 |
2019年 | 44篇 |
2018年 | 37篇 |
2017年 | 43篇 |
2016年 | 33篇 |
2015年 | 49篇 |
2014年 | 52篇 |
2013年 | 79篇 |
2012年 | 35篇 |
2011年 | 36篇 |
2010年 | 24篇 |
2009年 | 26篇 |
2008年 | 26篇 |
2007年 | 18篇 |
2006年 | 22篇 |
2005年 | 15篇 |
2004年 | 19篇 |
2003年 | 18篇 |
2002年 | 10篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 18篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 22篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 11篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1982年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有985条查询结果,搜索用时 46 毫秒
91.
本实验选用SD(Sprague Dawley)大鼠,建立大强度耐力训练模型,研究迷迭香对运动大鼠肝脏组织脂质过氧化损伤保护作用。结果显示,1)迷迭香可降低血清丙氨酸氨基转移酶活性,升高肝组织丙氨酸氨基转移酶的活性,都有显著性差异(P<0.05);2)迷迭香可以不同程度地增强肝脏组织中抗氧化酶SOD(superoxide dis-mutase)、CAT(catalase)和GSH-Px(glutathione peroxidase)的活性,其中SOD和CAT的活性增加在安静和运动状态下都有显著性差异(P<0.05),GSH-Px的活性增加在运动状态下具有显著性差异(P<0.05);3)迷迭香可以降低肝脏组织中MDA(malondialdehyde)的含量,无显著性差异(P>0.05)。结论:迷迭香可以增加肝脏组织中的抗氧化酶活性,减轻大强度耐力训练对大鼠肝脏组织造成的脂质过氧化损伤。并且在同一状态下对不同的抗氧化酶活性影响不同。 相似文献
92.
目的:探讨医学干预对南方某武警部队战士训练伤发生情况的影响。方法:随机将南方某武警部队的一大队,按照干预措施施训,作为干预组;另一大队按照以往常规方法进行训练,不加任何干预措施,作为对照组。观察6个月内的两大队(干预组和对照组)的训练伤发生情况。结果:骨关节和软组织损伤为常见。实施医疗干预可有效降低军事训练伤的发生率(17.95%〈29.18%),其主要效果在于大幅度降低了骨关节损伤的发生率(6.53%〈10.31%)和软组织损伤的发生率(5.59%〈9.92%)。结论:实施医学干预可有效降低我武警部队军事训练伤的发生率。 相似文献
93.
94.
Kathleen R. Pritchett-Corning Guy B. Mulder Yiying Luo William J. White 《Journal of visualized experiments : JoVE》2011,(47)
For both scientific and animal welfare reasons, training in basic surgical concepts and techniques should be undertaken before ever seeking to perform surgery on a rodent. Students, post-doctoral scholars, and others interested in performing surgery on rodents as part of a research protocol may not have had formal surgical training as part of their required coursework. Surgery itself is a technical skill, and one that will improve with practice. The principles of aseptic technique, however, often remain unexplained or untaught. For most new surgeons, this vital information is presented in piecemeal fashion or learned on the job, neither of which is ideal. It may also make learning how to perform a particular surgery difficult, as the new surgeon is learning both a surgical technique and the principles of asepsis at the same time. This article summarizes and makes recommendations for basic surgical skills and techniques necessary for successful rodent surgery. This article is designed to supplement hands-on training by the user''s institution. 相似文献
95.
目的:调查我院专科医师培训开展的整体情况,为继续做好专科医师培训工作提供依据。方法:随机调查我院参与普通专科医师培训轮转科室的指导教师,发放自制调查表。结果:90%以上导师认为科室带教质量高;48.78%导师认为临床科室应为学员每月发放1000元以上生活补助;60.98%导师认为硕士研究生普通专科医师培训时间应为二年;60%以上导师认为应着重硕士研究生临床操作技能、医患沟通能力、病历书写能力及阅片能力等方面能力的培训;50%以上导师认为目前培训中存在的主要问题是生活无保障;图书馆国内外最新文献不足;监管力度不强;临床技能培训针对性不强等。结论:我院开展普通专科医师培训整体情况较好。但仍存在很多问题,在今后的培训过程中应继续为学员的生活提供更多保障,继续加强管理监督,保证培训按计划、按质量完成。 相似文献
96.
Mero A Nykänen T Keinänen O Knuutinen J Lahti K Alen M Rasi S Leppäluoto J 《Amino acids》2005,28(3):327-335
Summary. This study was designed to determine the responses of muscle protein, serum amino acids, and strength performance to bovine colostrum supplementation in physically active men. The rest (R) group (n=6) and the exercise (E) group (n=6) carried out twice a 2-week experiment randomly assigned in a double-blind fashion with either placebo (PLA; consuming daily 20g maltodextrin) or bovine colostrum (COL; consuming daily 20g colostrum supplement) treatment with one month between. On the test day after the treatment period the measurements were carried out in fasting conditions and E carried out a strength training session (STS). The methods involved the infusion of ring-2H5-phenylalanine, femoral arterial and venous blood sampling, and biopsies from the vastus lateralis muscle. Serum concentration of essential amino acids during recovery was greater (p<0.05) in the COL groups compared with the PLA groups. Both muscle protein synthesis and breakdown increased (p<0.05) with COL. There were no differences in phenylalanine net balance or strength performance between the PLA and COL groups. It was concluded that a 2-week supplementation with bovine colostrum in physically active men increases serum concentration of essential amino acids but has no effect either on strength performance or protein net balance in fasting conditions during recovery after STS. 相似文献
97.
Groups of common carp (Cyprinus carpio) were trained for 33 days to discriminate between two acoustic signals differing in frequency and temporal pattern. One signal (positive stimulus) was reinforced by food, while the other (negative stimulus) was not rewarded. When exposed to 3 positive and 3 negative stimuli per day (training Paradigm 1) the fish responded similarly to the two signals. When daily negative stimuli outnumbered positive stimuli (3 positive and 33 negative, training Paradigm 2) the fish responded similarly to the two signals for the first 2 weeks and then began to discriminate between them. Discriminatory response was statistically significant from Day 21 of training. After 33 days, training was switched from Paradigm 2 to Paradigm 1 and the fish maintained their discriminatory capability. The results are interpreted in terms of anticipatory frustration and risk management. 相似文献
98.
Lambeth SP Hau J Perlman JE Martino M Schapiro SJ 《American journal of primatology》2006,68(3):245-256
Positive reinforcement training (PRT) techniques have received considerable attention for their stress reduction potential in the behavioral management of captive nonhuman primates. However, few published empirical studies have provided physiological data to support this position. To address this issue, PRT techniques were used to train chimpanzees (Pan troglodytes) to voluntarily present a leg for an intramuscular (IM) injection of anesthetic. Hematology and serum chemistry profiles were collected from healthy chimpanzees (n=128) of both sexes and various ages during their routine annual physical examinations over a 7-year period. Specific variables potentially indicative of acute stress (i.e., total white blood cell (WBC) counts, absolute segmented neutrophils (SEG), glucose (GLU) levels, and hematocrit (HCT) levels) were analyzed to determine whether the method used to administer the anesthetic (voluntary present for injection vs. involuntary injection) affected the physiological parameters. Subjects that voluntarily presented for an anesthetic injection had significantly lower mean total WBC counts, SEG, and GLU levels than subjects that were involuntarily anesthetized by more traditional means. Within-subjects analyses revealed the same pattern of results. This is one of the first data sets to objectively demonstrate that PRT for voluntary presentation of IM injections of anesthetic can significantly affect some of the physiological measures correlated with stress responses to chemical restraint in captive chimpanzees. 相似文献
99.
Four conditioned approach experiments with rats assessed for effects of number of acquisition trials on extinction of conditioned responding, when number of acquisition sessions and total acquisition time were held constant. In Experiment 1, 32 trials per acquisition session led to more extinction responding than did 1 or 2 trials per session but less than did 4 trials per session. In Experiment 2, 2 trials per acquisition session led to more spontaneous recovery than did 32 trials per session. These latter findings are reminiscent of the overtraining extinction effect (OEE). Experiment 3 attempted to reduce the OEE with a preconditioning phase of partial reinforcement. Experiment 4 attempted to reduce the beneficial within-subject effects of increasing the number of acquisition trials on extinction observed by Gottlieb and Rescorla (2010) by extinguishing stimuli in different sessions. Overall, results suggest a procedural asymmetry: between-subject, increasing the number of trials between any pair of trials does not lead to greater persistence of responding during extinction; within-subject, it does. Results are discussed from an associative perspective, with a focus on explanations involving either frustration or comparator mechanisms, and from an information processing perspective, with a focus on Rate Estimation Theory. 相似文献
100.
S. Walsh C.J. Haddad M.A. Kostek T.J. Angelopoulos P.M. Clarkson P.M. Gordon N.M. Moyna P.S. Visich R.F. Zoeller R.L. Seip S. Bilbie P.D. Thompson J. Devaney H. Gordish-Dressman E.P. Hoffman Thomas B. Price L.S. Pescatello 《Gene》2012