全文获取类型
收费全文 | 29708篇 |
免费 | 2579篇 |
国内免费 | 446篇 |
专业分类
耳鼻咽喉 | 193篇 |
儿科学 | 956篇 |
妇产科学 | 828篇 |
基础医学 | 4070篇 |
口腔科学 | 426篇 |
临床医学 | 3976篇 |
内科学 | 5233篇 |
皮肤病学 | 357篇 |
神经病学 | 3076篇 |
特种医学 | 584篇 |
外国民族医学 | 1篇 |
外科学 | 2500篇 |
综合类 | 1235篇 |
现状与发展 | 4篇 |
一般理论 | 47篇 |
预防医学 | 3437篇 |
眼科学 | 796篇 |
药学 | 2450篇 |
6篇 | |
中国医学 | 410篇 |
肿瘤学 | 2148篇 |
出版年
2023年 | 309篇 |
2022年 | 469篇 |
2021年 | 854篇 |
2020年 | 649篇 |
2019年 | 804篇 |
2018年 | 842篇 |
2017年 | 705篇 |
2016年 | 694篇 |
2015年 | 927篇 |
2014年 | 1186篇 |
2013年 | 1532篇 |
2012年 | 2179篇 |
2011年 | 2265篇 |
2010年 | 1282篇 |
2009年 | 1099篇 |
2008年 | 1775篇 |
2007年 | 1854篇 |
2006年 | 1873篇 |
2005年 | 1766篇 |
2004年 | 1657篇 |
2003年 | 1502篇 |
2002年 | 1403篇 |
2001年 | 406篇 |
2000年 | 340篇 |
1999年 | 384篇 |
1998年 | 320篇 |
1997年 | 297篇 |
1996年 | 243篇 |
1995年 | 243篇 |
1994年 | 166篇 |
1993年 | 188篇 |
1992年 | 199篇 |
1991年 | 180篇 |
1990年 | 153篇 |
1989年 | 168篇 |
1988年 | 124篇 |
1987年 | 116篇 |
1986年 | 93篇 |
1985年 | 94篇 |
1984年 | 92篇 |
1983年 | 97篇 |
1982年 | 92篇 |
1981年 | 94篇 |
1980年 | 95篇 |
1979年 | 74篇 |
1978年 | 63篇 |
1977年 | 54篇 |
1976年 | 50篇 |
1974年 | 54篇 |
1973年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Helen McDonald 《BJOG : an international journal of obstetrics and gynaecology》1998,105(11):1240-1240
82.
Constantine A Mangina J Helen Beuzeron-Mangina 《International journal of psychophysiology》2004,52(2):129-146
This research investigated the effects of a psychophysiological treatment methodology on brain plasticity as reflected in event-related brain potential topographic mapping and morphology along with School-marks and Mangina-Test performance in three different groups of pre-adolescents at baseline and 8 months later: (a) Learning Disabled/ADHD pre-adolescents who were treated; (b) Non-treated Learning Disabled/ADHD pre-adolescents; (c) Normal controls. Results indicate that: (1) the Event-Related Brain Potentials topographic mapping was significantly modified in post-treatment condition for the treated Learning/Disabled/ADHD group as opposed to pre-treatment baseline (P < 0.001). This was mainly due to the enhanced pre-frontal and frontal N450 amplitudes along with higher P450 components over posterior regions in post-treatment condition (P < 0.001); (2) for group comparisons at baseline, no significant topographic mapping differences were found between the treated Learning Disabled/ADHD group and the non-treated Learning Disabled/ADHD control group (P > 0.05) and significant differences were present between the treated Leaning Disabled/ADHD and the normal control group (P < 0.001); (3) 8 months later, in post-treatment condition, group comparisons revealed significant topographic mapping differences between the treated Learning Disabled/ADHD group and the non-treated Learning Disabled/ADHD control group (P < 0.001) and none between the treated Learning Disabled/ADHD group and the normal control group (P > 0.05); (4) the topographic mapping of both components was similar at baseline and 8 months later in both control groups (P > 0.05); (5) at baseline, school-marks and Mangina-Test performance of treated Learning Disabled/ADHD were not significantly different than those of the non-treated Learning Disabled/ADHD (P > 0.05) and significantly lower than those of the normal control group (P < 0.001); (6) the treated Learning Disabled/ADHD group in post-treatment condition had significantly higher school-marks and Mangina-Test performance than those of non-treated Learning Disabled/ADHD controls (P < 0.001) and were similar to those of normal controls 8 months later (P > 0.05); (7) school-marks and Mangina-Test performance at baseline for non-treated Learning Disabled/ADHD controls were not modified 8 months later (P > 0.05) and normal controls maintained their high performance within the same time interval (P > 0.05). These findings provide evidence of the impact of the psychophysiological treatment methodology on brain plasticity and regulation as reflected in significantly improved neurophysiology of pre-frontal, frontal and posterior brain regions concomitantly with higher school-marks and neuropsychometric performance in the Mangina-Test. 相似文献
83.
The effect of vascular endothelial growth factor on the healing of ischaemic skin wounds. 总被引:7,自引:0,他引:7
F Zhang M P Lei T M Oswald Y Pang B Blain Z W Cai W C Lineaweaver 《British journal of plastic surgery》2003,56(4):334-341
The effect of exogenous vascular endothelium growth factor (VEGF) on wound healing in an ischaemic skin flap model was evaluated in this study. Seventy-two Sprague-Dawley rats were used. Normal incisional wound and H-shaped double flaps were used as the wound models. The study was divided into two parts. In Part I, VEGF protein levels were determined from the incisional and H-shaped ischaemic wounds at 12 and 24 h, postoperatively. In Part II, tensile strength and immunohistochemical stains were examined to determine the level of microvessel density (MVD) at 1 and 2 weeks, postoperatively in simple incisional wounds, ischaemic wounds, and ischaemic wounds following 1 ml (1 microg/ml) exogenous VEGF injections into the subcutaneous tissue. The results showed a significantly higher level of VEGF protein in the ischaemic wounds than the incisional wounds. Tensile strength was statistically higher in the incisional wound group and in the ischaemic flap wounds with VEGF treatment compared to the ischaemic flaps with no treatment at 1 week, postoperatively (p>0.05). MVD data indicated that ischaemic wound repair with VEGF treatment had significantly higher MVD than the normal incisional wounds and ischaemic wounds without treatment. We conclude that exogenous application of VEGF can increase early angiogenesis and tensile strength in the ischaemic wound. 相似文献
84.
85.
The present paper introduces the concept of the narcissistically vulnerable system by suggesting that organizations may manifest some of the same pathological characteristics as narcissistic individuals. The public mental hospital was chosen as an example of such a system. Reasons for its vulnerability were suggested and specific defenses, employed at the system level, were discussed. Finally, remedies for the repair of the narcissistically vulnerable system were considered. 相似文献
86.
抗人生长激素免疫血清的制备和鉴定 总被引:1,自引:1,他引:0
Using small dosage of human growth hormone to immunize rabbit or guinea pig, it is able to induce anti-hGH antibody formation with high titre and high affinity that could be applied to hGH RIA. In the present study five rabbits and three guinea pigs were immunized with 125-200 micrograms and 250-285 micrograms per animal of hGH respectively, followed by boosters of 10-20 or 160-250 micrograms of hGH at 2-4 week intervals for 6 or 3 months. Blood was drown 1-2 weeks before each booster for determination of antibody formation. Antibody titre and affinity were successively observed and specificity of antibody was determined for the final bleeding. It was shown that titres of immune sera from guinea pigs were much higher than those of rabbit immune sera, but vice versa for antibody affinity. This might be due to larger immunogen dose used for guinea pigs than for rabbits. Fourteen different peptide hormones were tested in reference to cross-immunoreactivity to anti-hGH antibody. It could be demonstrated that the major cross-reactive hormones are hFSH and hLH, and hTSH also reacts to rabbit anti-hGH immune sera at a lesser degree. These cross reactivities are obviously owing to the molecular homogeneities between hGH and these hormones especially of their alpha-subunits. 相似文献
87.
Helen McCabe RGN BHA MA PhD 《Nursing philosophy》2007,8(3):167-175
Abstract Preference utilitarians are concerned to maximize the autonomous choices of individuals; for this reason, they argue that nurses ought to advocate for those patients who desire assistance with ending their lives. This approach prompts us to consider, then, the moral validity of nursing involvement in measures intended to end the lives of patients. In this article, the terms of preference utilitarianism are set out and considered in order to determine whether this approach offers sufficient philosophical support for sanctioning a role for nursing in euthanasia. Ultimately, it is found that preference utilitarianism is lacking in this respect, as well as in its fitness for guiding nursing activity in general. In particular, it is found that nurses are required to exchange a handmaiden relationship with the medical profession for an equally undignified relationship with patients. If nursing involvement in measures intended to end the lives of patients is to find sufficient philosophical support, then we need to look elsewhere. 相似文献
88.
89.
90.
Helen E. Savaki Jean-Antoine Girault Umberto Spampinato Ngog-An Truong Jacques Glowinski Marie-Jo Besson 《Brain research bulletin》1986,16(2)
The release of newly synthesized 3H-dopamine (3H-DA) was measured in the rat striatum superfused, through a push-pull cannula, with a physiological medium enriched in 3H-tyrosine. The level of spontaneous 3H-DA release was dependent on the topographical localisation of the cannula in the striatum (anterior parts displayed higher levels than posterior ones) and on the anesthetic state (halothane anesthetized rats demonstrated higher levels than awake ones). Inhibition of DA inactivation processes by local application of benztropine (a DA reuptake inhibitor, 10−6 M) or by IV administration of pargyline (a MAO inhibitor, 100 mg/kg) enhanced the detectable outflow of 3H-DA from the striatum in both halothane anesthetized and awake rats. Local application of D-amphetamine (10−5 M) or acetylcholine (5 × 10−5 M) in the presence of eserine (5 × 10−5 M) evoked respectively a fivefold and a 30% increase in spontaneous 3H-DA release in halothane anesthetized rats. Inhibition of the firing of dopaminergic neurons by IV injection of gamma-hydroxybutyrate (400 mg/kg) produced a 30% decrease in striatal 3H-DA release. The present results demonstrate that the push-pull cannula method is suitable for the study of DA release in both the anesthetized and the awake rat. 相似文献