全文获取类型
收费全文 | 25706篇 |
免费 | 1787篇 |
国内免费 | 693篇 |
专业分类
耳鼻咽喉 | 180篇 |
儿科学 | 435篇 |
妇产科学 | 46篇 |
基础医学 | 5059篇 |
口腔科学 | 153篇 |
临床医学 | 1854篇 |
内科学 | 1151篇 |
皮肤病学 | 18篇 |
神经病学 | 13756篇 |
特种医学 | 460篇 |
外科学 | 981篇 |
综合类 | 1241篇 |
预防医学 | 594篇 |
眼科学 | 341篇 |
药学 | 1486篇 |
13篇 | |
中国医学 | 353篇 |
肿瘤学 | 65篇 |
出版年
2024年 | 41篇 |
2023年 | 188篇 |
2022年 | 316篇 |
2021年 | 732篇 |
2020年 | 698篇 |
2019年 | 690篇 |
2018年 | 634篇 |
2017年 | 702篇 |
2016年 | 673篇 |
2015年 | 748篇 |
2014年 | 1011篇 |
2013年 | 1424篇 |
2012年 | 1095篇 |
2011年 | 1284篇 |
2010年 | 1163篇 |
2009年 | 1218篇 |
2008年 | 1257篇 |
2007年 | 1212篇 |
2006年 | 1167篇 |
2005年 | 953篇 |
2004年 | 862篇 |
2003年 | 776篇 |
2002年 | 644篇 |
2001年 | 576篇 |
2000年 | 456篇 |
1999年 | 496篇 |
1998年 | 561篇 |
1997年 | 535篇 |
1996年 | 457篇 |
1995年 | 378篇 |
1994年 | 368篇 |
1993年 | 340篇 |
1992年 | 343篇 |
1991年 | 342篇 |
1990年 | 304篇 |
1989年 | 294篇 |
1988年 | 294篇 |
1987年 | 263篇 |
1986年 | 322篇 |
1985年 | 477篇 |
1984年 | 364篇 |
1983年 | 304篇 |
1982年 | 269篇 |
1981年 | 237篇 |
1980年 | 196篇 |
1979年 | 127篇 |
1978年 | 92篇 |
1977年 | 75篇 |
1976年 | 63篇 |
1973年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 419 毫秒
41.
目的探讨烧伤后早期在深Ⅱ度创面削痂手术中使用电动取皮刀准确削痂,对创面进程和愈合质量的影响。方法选择62例深Ⅱ度烧伤患,随机分为二组,均在伤后72h内进行创面削痂手术。术中分别使用电动取皮刀和滚轴取皮刀削痂,观察术中削痂创面出血量、手术所需时间、创面愈合时间及残留肉芽创面的发生事。结果早期对深Ⅱ度创面削痂能降低局部炎症反应。与滚轴取皮刀削痂相比较,用电动取皮刀削痂可降低残留创面的发生率22.6%,缩短病程3.5d。结论电动取皮刀削痂可尽量保存残存的皮肤附件,避免使用滚轴取皮刀削痴过程中经常出现的削痂创面边缘锯齿样切口,也可以避免因术经验、技术的不足所导致的削痴过浅或过深的问题,促进创面愈合和缩短病程,是一种简单易行的削痂方法。 相似文献
42.
Understanding the mechanisms of food intake and obesity 总被引:2,自引:1,他引:1
E. T. Rolls 《Obesity reviews》2007,8(S1):67-72
43.
44.
益气复智颗粒对多发脑梗死性痴呆模型大鼠脑组织细胞凋亡的影响 总被引:1,自引:0,他引:1
目的 观察益气复智颗粒对多发脑梗死性痴呆模型大鼠脑皮质形态学、细胞凋亡的影响。方法 采用颈内动脉注射血栓的方法,复制多发梗死性痴呆大鼠模型,观察益气复智颗粒12.42g/kg分别于手术前、手术前后、手术后灌胃对实验动物脑皮质形态学、细胞凋亡的影响。结果 益气复智颗粒能使脑缺血后脑内神经细胞凋亡数目下降。结论 益气复智颗粒具有较好的保护脑神经元,阻断脑缺血致神经细胞死亡病理过程的作用。 相似文献
45.
Rainer Cammann Ariane Miehlke 《Journal of child psychology and psychiatry, and allied disciplines》1989,30(6):899-906
All non-task-related body movements during school hours were listed in 11 normally active and 12 hyperactive boys. The mean number of movements was 48 +/- 7 per 45 minutes in the normal actives and 79 +/- 16 per 45 minutes in the hyperactives. The rather monotonous increment and decrement of motor activity during the 4-hr registration period was noticed only in hyperactive boys. These results could be a consequence of a circadian rhythm, as there was independence of type of school hours and of teacher personality. The cyclical level of activity in hyperactive boys was sometimes in the range of the normal actives. 相似文献
46.
Ramified microglial cells were investigated in primary cultures of dissociated cerebral cortical tissue from rats. The identification of these cells was confirmed through immunohistochemical staining with 7 monoclonal antibodies selective for microglia. While there was significant variation in staining intensity with different antibodies, all stained the identified ramified cells; the antibodies OX-42 and ED1 yielded the most intense immunoreactivity. Based on distinctive morphological features, the microglia could be identified in living cultures where they were monitored using time-lapse video recording. This technique revealed extremely dynamic features of cellular plasticity and motility. Ramified microglia exhibited constant and rapid alterations in the size and shape of their cell body with an associated extension and retraction of processes; concomitantly, the cells moved about in a circumscribed area. These features of plasticity and motility were unique to this cell type, and correlated with OX-42 immunostaining. The microglia also possessed a differentially high level of pinocytotic activity; this too was correlated with OX-42 staining. From the nature of their morphological plasticity and motility, high pinocytosis, and cellular distribution, it is hypothesized that the ramified microglia specifically function as a system of fluid cleansing in normal brain tissue. 相似文献
47.
The mechanism of action of systemitically administered(±)-MDMA (3, 4-methylenedioxymethamphetamine) on spontaneously active neurons in the medial prefrontal cortex (mPFc) of chloral hydrate anesthetized rats was examined using standard single unit extracellular recording techniques. Intravenously administered MDMA dose-dependently decreased the firing rates of the majority of mPFc neurons in control rats. In contrast, in rats that were pretreated withp-chlorophenylalanine (PCPA), which depletes the brain serotonin (5-hydroxytryptamine, 5-HT) content by inhibiting tryptophan hydroxylase, the rate-limiting enzyme in the synthesis of 5-HT, MDMA was largely ineffective in inhibiting the firing of mPFc cells. In PCPA-treated animals, the administration of 5-hydroxytryptophan (5-HTP), which presumably restored the brain 5-HT content, but notl-DOPA, reinstated MDMA's inhibitory action in PCPA-treated rats. In rats that were pretreated withα-methyl-p-tyrosine (AMPT), which depletes the brain dopamine (DA) content by inhibiting tyrosine hydroxylase, the rate-limiting enzyme in the synthesis of DA, MDMA inhibited the firing of all of the mPFc cells. MDMA's effect on mPFc neurons was reversed by 5-HT receptor antagonists such as granisetron and metergoline. These results strongly suggest that MDMA exerts its action on mPFc cells indirectly by releasing endogenous 5-HT. 相似文献
48.
49.
M. W. Oram D. I. Perrett J. K. Hietanen 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1993,97(2):274-294
An investigation was made into the directional sensitivity of cells in the macaque anterior superior temporal polysensory region (STPa) to the motion of objects. The cells studied were sensitive to the presence of motion but showed little or no selectivity for the form of the stimulus. Directional tuning was not continuously distributed about all possible directions. The majority of cells were most responsive to motion in a direction within 15° of one of the three cartesian axes (up/down, left/right, towards/away). Tuning to direction varied in sharpness. For most (34/37) cells the angular change in direction required to reduce response to half maximal was between 45 and 70° (for 3/37 cells it was > 90°). The estimates of the directionality (median I
d = 0.97) of STPa cells was similar to that reported for posterior motion processing areas (the middle temporal area, MT, and the medial superior temporal area, MST). The tuning for direction (sharpness, distribution and discrimination) of the motion-sensitive STPa cells were found to be similar to the tuning for perspective view of STPa cells selective for static form of the head and body. On average the STPa responses showed a 100- to 300-ms transient burst of activity followed by a tonic discharge maintained at approximately 20% of the peak firing rate for the duration of stimulation. The responses of motion-sensitive STPa cells occurred at an earlier latency (mean 91 ms) than responses of cells selective for static form (mean 119 ms), but the time course of responses of the two classes of cell were similar in many other respects. The early response latency and directional selectivity indicate that motion sensitivity in STPa cells derives from the dorsal visual pathway via MT/MST. The similarity of tuning for direction and perspective view within STPa may facilitate the integration of motion and form processing within this high-level brain area. 相似文献
50.
Circumscribed low grade astrocytomas in the dominant opercular and insular region: A pilot study 总被引:4,自引:0,他引:4
Summary Intraoperative mapping techniques allow a reliable identification or exclusion of eloquent brain areas and are well tolerated by the patients. In dominant opercular tumours radical surgery can only be achieved without lasting deficits with intraoperative histological examination of the resection line and mapping. If an early post-operative MRI shows residual opercular tumour in non-eloquent areas re-operation is recommended.In large dominant insular or opercular-insular tumours only biopsy is recommended, because only an incomplete removal can be accomplished, because the trial of radical removal carries a high risk of postoperative deficits due to possible vascular damage of the lenticulo-striate arteries or internal capsule. Because subtotal removal of low grade gliomas does not increase the progression free interval, we would not recommend surgery in these cases, as they carry a significant risk of a further deficit. 相似文献