全文获取类型
收费全文 | 87889篇 |
免费 | 7630篇 |
国内免费 | 5140篇 |
专业分类
耳鼻咽喉 | 1005篇 |
儿科学 | 1170篇 |
妇产科学 | 911篇 |
基础医学 | 10679篇 |
口腔科学 | 1573篇 |
临床医学 | 9636篇 |
内科学 | 12768篇 |
皮肤病学 | 1525篇 |
神经病学 | 4335篇 |
特种医学 | 4170篇 |
外国民族医学 | 22篇 |
外科学 | 8861篇 |
综合类 | 13858篇 |
现状与发展 | 29篇 |
一般理论 | 9篇 |
预防医学 | 6099篇 |
眼科学 | 2535篇 |
药学 | 9530篇 |
77篇 | |
中国医学 | 4509篇 |
肿瘤学 | 7358篇 |
出版年
2024年 | 225篇 |
2023年 | 1082篇 |
2022年 | 2751篇 |
2021年 | 3761篇 |
2020年 | 2791篇 |
2019年 | 2535篇 |
2018年 | 2707篇 |
2017年 | 2570篇 |
2016年 | 2701篇 |
2015年 | 4021篇 |
2014年 | 5017篇 |
2013年 | 4960篇 |
2012年 | 7223篇 |
2011年 | 7683篇 |
2010年 | 5150篇 |
2009年 | 4411篇 |
2008年 | 5528篇 |
2007年 | 5222篇 |
2006年 | 4908篇 |
2005年 | 4392篇 |
2004年 | 3334篇 |
2003年 | 3377篇 |
2002年 | 2829篇 |
2001年 | 1994篇 |
2000年 | 1629篇 |
1999年 | 1423篇 |
1998年 | 890篇 |
1997年 | 804篇 |
1996年 | 677篇 |
1995年 | 615篇 |
1994年 | 577篇 |
1993年 | 395篇 |
1992年 | 423篇 |
1991年 | 402篇 |
1990年 | 331篇 |
1989年 | 302篇 |
1988年 | 200篇 |
1987年 | 222篇 |
1986年 | 173篇 |
1985年 | 109篇 |
1984年 | 64篇 |
1983年 | 49篇 |
1982年 | 45篇 |
1981年 | 32篇 |
1980年 | 32篇 |
1979年 | 20篇 |
1978年 | 11篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1973年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
人精子穿卵改良试验对不同生育状态男子生育力测定的价值 总被引:2,自引:0,他引:2
目的 本研究用一种经改良的人精子穿卵试验 (SPA)处理人精子 ,以探讨一种更简便、快速、经济 ,适合一般实验室要求的方法。方法 将精子体外获能液用磷酸氢二钠把pH值调理至 8.2± 0 .2 ;用普通隔水式恒温培养箱进行培养 ;对 75例不同生育状态男子生育力进行测定 (其中 2 5例有生育力男子 ;2 5例“原因不明”不育男子 ;及 2 5例输精管吻合术后 )。结果 3种不同生育状态男子的SPA值分别是 (4 7.12± 9.92 ) % ;(2 1.73± 9.91) % ,及 (2 8.0 4± 9.91) %。前两者在统计学上有显著差异 ,(P<0 .0 1) ;后两者在统计学上无明显差异 (P >0 .0 5 )。结果表明经用改良的精子获能液并在普通恒温培养箱培养后精子的活率和活力都有较大的提高 ,这有利于精子的长期获能及提高精子的穿透能力。结论 本研究提示改良后的人精子穿卵试验处理精子确实更简便、快速、经济 ,适合一般实验室要求 ,便于推广。 相似文献
23.
The purpose of the present study was to determine the reliability of several selected signs of trauma from occlusion and their relations with severity of periodontitis. 32 moderate to advanced chronic periodontitis patients participated in the study. All teeth present were evaluated for various abnormal occlusal contacts, signs of trauma from occlusion, and the severity of periodontitis. Standardized periapical radiographs were also taken for each tooth. The results demonstrated that: (1) no significant difference occurred in probing pocket depth (PD), clinical attachment loss (AL), or percentage of alveolar bone height (BH) between teeth with and without various abnormal occlusal contacts, i.e., premature contacts in centric relation occlusion, non-working contacts in lateral excursions, premature contacts of anterior teeth or posterior protrusive tooth contacts; (2) teeth with either significant mobility, functional mobility, or radiographically widened periodontal ligament space (PDLS) had deeper PD, more AL and lower BH than teeth without these signs, while teeth with pronounced wear or radiographically thickened lamina dura had less AL than teeth without these findings; (3) 2 combined indices, i.e., the trauma from occlusion index (TOI) and the adaptability index (AI), were proposed for the identification of occlusal trauma and the response of periodontium to excessive biting forces in heavy function, respectively; TOI-positive teeth exhibit deeper PD, more AL and less osseous support than TOI-negative teeth; however, AI-positive teeth had less AL and more osseous support than AI-negative teeth; (4) with identical attachment level, TOI-positive teeth had less osseous support than TOI-negative teeth while the magnitude of difference became greater with an increase of attachment loss. 相似文献
24.
25.
26.
温针灸治疗颞下颌关节功能紊乱病36例 总被引:1,自引:0,他引:1
目的:比较温针灸与口服西药治疗颞下颌关节功能紊乱病的疗效。方法:治疗组36例取下关、牵正、颊车、阿是穴、合谷(双)行温针灸,对照组口服地西泮、吲哚美辛。结果:治疗组治愈率80·6%、总有效率100%,对照组治愈率40·6%、总有效率78·1%,两组有非常显著性差异(P<0.01)。结论:温针灸治疗颞下颌关节功能紊乱病方法简单,疗效显著。 相似文献
27.
目的:通过对患者在住院过程中的系统教育,使患者了解自己疾病的知识,提高患者对糖尿病的认知水平和自我管理能力,养成良好的健康行为和生活方式,从而提高生活质量。方法:采用集体、个体、自学等形式进行教育。结果:通过培养,患者掌握了一些基本的操作技能,明显缩短了住院日,同时激发了护士与患者学习专业知识的热情,减少或延缓了并发症的发生。结论:①健康教育是一个护患双边活动过程。②通过教育,可不断提高护士的自身修养和专业知识水平。③健康教育是糖尿病患者学习糖尿病知识,提高自我护理能力的有效途径。 相似文献
28.
A multivariate study of protective effects of Zn and Cu against nephrotoxicity induced by cadmium metallothionein in rats. 总被引:3,自引:0,他引:3
X Y Liu T Y Jin G F Nordberg S R?nnar M Sj?str?m Y Zhou 《Toxicology and applied pharmacology》1992,114(2):239-245
Factorial experimental design was used to study the protective effects of Zn and Cu on cadmium-metallothionein(CdMT)-induced nephrotoxicity in male Wistar rats. In the factorial design two levels of Zn (0 and 25 mg/kg body weight), two levels of Cu (0 and 12.5 mg/kg), and two levels of CdMT (0.1 and 0.4 mg of Cd/kg) were used as varied factors. The factorial design was complemented with a center point with all three variables at an intermediate setting, i.e., Zn at 12.5 mg/kg, Cu at 6.25 mg/kg, and CdMT at 0.25 mg Cd/kg. Each of the nine combinations of settings was administered to one of nine groups with six rats in each. Zn and Cu were injected sc 24 hr prior to the injection of CdMT. The concentrations of protein and Ca in urine and Ca in renal cortex were used as effects. The relationship between the experimental design settings and the effects were modeled with multiple regression. The multiple regression analysis revealed that for the high dose of CdMT (i) the enhanced values of protein in urine caused by CdMT injection could be more efficiently reduced by Zn than by Cu, and (ii) excessive Ca in urine and renal cortex could be more efficiently reduced by Cu than by Zn. No significant synergism or antagonism between Cu and Zn was found. These models can be used to estimate the dose levels of Zn and Cu which will reduce the toxic effects of CdMT. The treatment of 20.4 mg/kg Zn, for example, will reduce the effects of 0.4 mg Cd/kg as CdMT on protein in urine, and 2.8 mg/kg Cu will reduce the Ca in urine to the levels of those caused by 0.25 mg Cd/kg (no Zn and Cu). Similarly, the effect of 0.4 mg Cd/kg on Ca level in renal cortex can be reduced to that of 0.28 mg Cd/kg as CdMT by 7.98 mg Cu/kg, which is three times as efficient as Zn. The obtained results might be of importance in understanding the mechanism of cadmium toxicity and the potential risk to the health of the population exposed to cadmium occupationally or environmentally. 相似文献
29.
用二甲苯所致的急性炎症模型观察了神效止痛膏的抗急性炎症作用.用扭体法、热板法观察了神效止痛膏对小鼠的镇痛作用.结果表明,神效止痛膏有很好的镇痛作用. 相似文献
30.
We investigate the role that the superior colliculus (SC) and the cerebellum might play in generating gaze shifts. The discharge of cells in the intermediate layers of the SC is tightly linked to the occurrence of saccades. Many studies have demonstrated that the cerebellum is involved in both eye and head movements. When the head is unrestrained, large amplitude gaze shifts are composed of coordinated eye and head movements. In this study, we propose that the gaze saccades system is controlled by a feedback loop between the SC and the cerebellum. The SC only encodes retinal coordinates and controls the eye displacement (to move the fovea to the target), while the cerebellum deals with the gaze programming and controls the head displacement. When a target appears in space, the buildup cells within the SC decode the target signal in the retina before the saccade onset, and input the signal of the gaze displacement to the cerebellum. The cells in the cerebellum vermis encode the initial position of the eye in the orbit. The gaze displacement is decomposed into the head amplitude and the eye amplitude within the cerebellum. There are two output signals from the cerebellum. One signal controls the head movement. The other is projected back to the SC, and forms a component of the saccade vector to control the eye movement. The sum of the vectors provided by the cerebellum and the vector provided by the burst cells in the SC indicates the direction and the amplitude of the desired movement of the eye during the saccade. We propose a cerebellum model to predict the displacements of the eye and head under the condition that the position of the target signal in the retina and the initial position of the eye in the orbit are known. The results from the model are close to that observed physiologically. We conclude that before gaze shift onset, the cerebellum may play an important role in decomposing the gaze displacement into an eye amplitude and head amplitude signal. 相似文献