全文获取类型
收费全文 | 54310篇 |
免费 | 3605篇 |
国内免费 | 1783篇 |
专业分类
耳鼻咽喉 | 864篇 |
儿科学 | 1205篇 |
妇产科学 | 883篇 |
基础医学 | 4777篇 |
口腔科学 | 1090篇 |
临床医学 | 5455篇 |
内科学 | 7745篇 |
皮肤病学 | 1971篇 |
神经病学 | 2918篇 |
特种医学 | 1325篇 |
外国民族医学 | 3篇 |
外科学 | 6523篇 |
综合类 | 7863篇 |
现状与发展 | 6篇 |
预防医学 | 5092篇 |
眼科学 | 623篇 |
药学 | 7002篇 |
59篇 | |
中国医学 | 2289篇 |
肿瘤学 | 2005篇 |
出版年
2024年 | 110篇 |
2023年 | 821篇 |
2022年 | 1628篇 |
2021年 | 2244篇 |
2020年 | 2079篇 |
2019年 | 1781篇 |
2018年 | 1813篇 |
2017年 | 1799篇 |
2016年 | 1890篇 |
2015年 | 1968篇 |
2014年 | 3736篇 |
2013年 | 3963篇 |
2012年 | 3461篇 |
2011年 | 3660篇 |
2010年 | 2922篇 |
2009年 | 2678篇 |
2008年 | 2634篇 |
2007年 | 2647篇 |
2006年 | 2185篇 |
2005年 | 1994篇 |
2004年 | 1622篇 |
2003年 | 1378篇 |
2002年 | 1098篇 |
2001年 | 1005篇 |
2000年 | 862篇 |
1999年 | 794篇 |
1998年 | 637篇 |
1997年 | 615篇 |
1996年 | 544篇 |
1995年 | 543篇 |
1994年 | 484篇 |
1993年 | 373篇 |
1992年 | 427篇 |
1991年 | 376篇 |
1990年 | 309篇 |
1989年 | 319篇 |
1988年 | 306篇 |
1987年 | 278篇 |
1986年 | 233篇 |
1985年 | 256篇 |
1984年 | 196篇 |
1983年 | 162篇 |
1982年 | 179篇 |
1981年 | 137篇 |
1980年 | 118篇 |
1979年 | 89篇 |
1978年 | 77篇 |
1977年 | 63篇 |
1976年 | 48篇 |
1975年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Yukihisa Fukuda Savio L-Y Woo John C Loh Eiichi Tsuda Peter Tang Patrick J McMahon Richard E Debski 《Journal of orthopaedic research》2003,21(6):1107-1112
The loads needed to elicit a positive pivot shift test in a knee with an anterior cruciate ligament (ACL) rupture have not been quantified. The coupled anterior tibial translation (ATT), coupled internal tibial rotation (ITR), and the in situ force in the ACL in response to a valgus torque, an inherent component of the pivot shift test, were measured in 10 human cadaveric knee specimens. Using a robotic/universal force-moment sensor testing system, valgus torques ranging from 0.0 to 10.0 Nm were applied in nine increments on the intact and ACL-deficient knee in flexion ranging from 0 degrees to 90 degrees. At 15 degrees of knee flexion, the coupled ATT and ITR were significantly increased in the ACL-deficient knee when compared to the intact knee. Coupled ATT increased a maximum of 291% (6.7 mm, p<0.05), while coupled ITR increased a maximum of 85% (5.1 degrees, p<0.05). At 30 degrees, the increases in coupled ATT and ITR were significant at valgus loads of 3.3 Nm and greater with a maximum increase in coupled ATT of 137% (6.3 mm, p<0.05) and a maximum increase in coupled ITR of 38% (3.6 degrees, p<0.05). At 45 degrees, coupled ATT increased significantly (maximum of 69%, 4.4 mm, p<0.05), but only at torques > or =6.7 Nm. The in situ force in the ACL was less than 20 N for all flexion angles when a torque between 3.3 and 5.0 Nm was applied. Low valgus torque elicited tibial subluxation in the ACL-deficient knee with low in situ ACL forces, similar to a positive pivot shift test. Thus, application of a valgus torque may be suitable to evaluate ACL-deficient and ACL-reconstructed knees, since subluxation can be achieved with minimal harm to the ACL graft. This work is important in understanding one load component needed for the pivot shift examination; further studies quantifying other load components are essential for better comprehension of the in vivo pivot shift examination. 相似文献
53.
测定了马杜霉素渣中铅、砷、镉、铬的含量及对小白鼠的毒性和对鸡的抗球虫性能。试验结果:马杜霉素渣中铅含量1.05mg/kg,砷含量小于1.0mg/kg,镉含量1.2mg/kg,铬含量26mg/kg;马杜霉素渣对小白鼠的LD50为354.65mg/kg,比马杜霉素毒性大。马杜霉素渣的抗球虫指数为173~175.1,属中等强度抗球虫药。以上结果表明,马杜霉素渣可以作为抗球虫药应用,但应用时要防止中毒的发生。 相似文献
54.
本文应用日本血吸虫虫卵单克隆抗体及虫卵可溶性抗原,分别致敏新型免疫微球载体重氮基聚苯乙烯乳胶,制备出血吸虫反向乳凝试剂与乳凝试剂,并用于检测血吸虫病患者血清标本中的相应抗原和相应抗体,以此试验检测197份急慢性血吸虫病患者血清标本。结果反向乳凝试剂检出率为90.4%,乳凝试剂检出率为95.2%,均高于反向间接血凝法的85.0%。反向乳凝试验与乳凝试验联合应用,既可早期诊断,又可判断疗效。试验采用玻片凝集法,3min内即出结果,方法敏感.特异、简便和快速。 相似文献
55.
56.
Julian J. Faraway 《Genetic epidemiology》1993,10(4):225-233
An improved sib-pair test for linkage is introduced which is superior to the previously proposed tests. The test is derived from the standard chi-squared goodness of fit statistic by restricting the alternative hypothesis to the genetically possible. Critical values are given and exact power comparisons are made with the previously proposed tests. The new test is shown to be more powerful for finite samples as well as being asymptotically uniformly most powerful. © 1993 Wiley-Liss, Inc. 相似文献
57.
Patients suffering from semantic dementia provide important constraints on theories of the structure and organisation of semantic memory. In this article we report one such patient, AM, whose progressive deterioration of semantics enables us to address the much-debated issue of whether conceptual structure is hierarchically organised. The hierarchical account predicts that brain damage should impair lower levels of the hierarchy (property information) before affecting higher level (category) information (Warrington and Shallice, Q. J. Exp. Psychol. 1975, 27, 635–657). We evaluate this prediction by repeated testing of AM in two studies—a semantic priming task and a verification task—over an 18 month period, contrasting the progressive deterioration of properties (functional and perceptual) and category relations (category co-ordinates and category labels). Properties were preserved longer than category information, arguing against a hierarchical account of semantic memory. In addition, functional properties were most robust to brain damage, supporting our claim that functional information plays a special role in semantic representations (Durrant-Peatfield et al., Proc. 19th Ann. Conf. of the Cognitive Science Society. Erlbaum, Mahwah, NJ, 1997, pp. 193–198. Tyler et al., Cognitive Neuropsychol. 1997, 14, 511–545). 相似文献
58.
T. O. Klemsdal H. H. Mundal K. Gjesdal 《European journal of clinical pharmacology》1996,51(3-4):227-230
Objective:
We examined the relationship between tolerance development, counterregulatory responses and arterial vasodilating effects
evaluated by digital pulse plethysmography.
Methods:
Twenty patients with stable angina pectoris were exercise tested before, after 2 and after 24 h of open nitrate patch treatment.
Results:
The effects observed after 2 h of treatment on exercise duration, ST-segment depression, blood pressure and heart rate were
lost in most individuals after 24 h. In contrast, the effects on the arterial pulse curves persisted after 24 h, with a mean
change from baseline of 29%, compared to 33% at 2 h. After 24 h, a significant decrease in haematocrit and an increase in
body weight were observed. The haematocrit changes correlated with the loss of clinical efficacy (r =0.57 for ST-segment depression, and r =0.54 for exercise duration).
Conclusion:
Clinical nitrate tolerance may be observed despite maintenance of the arterial vasodilating effects, and tolerance is more
related to plasma volume expansion as a counterregulatory mechanism.
Received: 28 February 1996/Accepted in revised form: 5 July 1996 相似文献
59.
A 62-year-old woman with diabetic triopathy developed widespread erythematous macules, numerous pustules, and a high fever after she underwent electric coagulation for vitreous hemorrhage. She was administered several drugs at that time. After discontinuation of the drugs, the eruption disappeared, and the fever returned to normal within two weeks. A positive patch test with isepamicin sulfate highly suggested that the symptoms described above were due to drug allergy. Cadralazine, which was positive in the drug lymphocyte stimulation test (DLST), could not be excluded from the causative drugs. A false-positive DLST with ofloxacin was confirmed by an accidental challenge test. To our knowledge, this is the first report of acute generalized exanthematous pustulosis due to isepamicin sulfate and/or cadralazine. 相似文献
60.
Auditory and vestibular system findings in patients with vertebrobasilar dolichoectasia 总被引:5,自引:0,他引:5
Impairment of the auditory-vestibular system has been reported in patients with vertebrobasilar dolichoectasia (VBD), but little is known about the underlying cause of the symptoms. Auditory testing (pure tone audiometry, auditory brain stem response and stapedius reflex) and vestibular tests (assessment of nystagmus, eye tracking tests, caloric test and rotational test) were performed in 23 patients with auditory-vestibular symptoms and/or cranial nerve impairment associated with VBD. Specific evidence of auditory and/or vestibular system impairment was observed in 19 cases (83%). Among patients with abnormal test findings, 47% had evidence suggesting peripheral impairment, 16% evidence suggesting central dysfunction, and 37% evidence suggesting both peripheral and central dysfunction. Although compression of the vestibulocochlear nerve plays an important role in the genesis of the auditory-vestibular dysfunction in patients with VBD, mechanism such as brain stem-cerebellar ischemia and impaired blood supply to the vestibular labyrinth may be just as important. 相似文献