全文获取类型
收费全文 | 128486篇 |
免费 | 8904篇 |
国内免费 | 429篇 |
专业分类
耳鼻咽喉 | 1524篇 |
儿科学 | 3624篇 |
妇产科学 | 2526篇 |
基础医学 | 18691篇 |
口腔科学 | 2769篇 |
临床医学 | 12601篇 |
内科学 | 26794篇 |
皮肤病学 | 2333篇 |
神经病学 | 13490篇 |
特种医学 | 5271篇 |
外国民族医学 | 20篇 |
外科学 | 18358篇 |
综合类 | 1383篇 |
一般理论 | 76篇 |
预防医学 | 9352篇 |
眼科学 | 2259篇 |
药学 | 8281篇 |
中国医学 | 130篇 |
肿瘤学 | 8337篇 |
出版年
2023年 | 689篇 |
2022年 | 1280篇 |
2021年 | 2471篇 |
2020年 | 1552篇 |
2019年 | 2270篇 |
2018年 | 2825篇 |
2017年 | 2118篇 |
2016年 | 2597篇 |
2015年 | 2933篇 |
2014年 | 3882篇 |
2013年 | 5103篇 |
2012年 | 7768篇 |
2011年 | 7927篇 |
2010年 | 4556篇 |
2009年 | 4268篇 |
2008年 | 7050篇 |
2007年 | 7625篇 |
2006年 | 7078篇 |
2005年 | 7073篇 |
2004年 | 6489篇 |
2003年 | 5877篇 |
2002年 | 5775篇 |
2001年 | 2776篇 |
2000年 | 2739篇 |
1999年 | 2464篇 |
1998年 | 1560篇 |
1997年 | 1262篇 |
1996年 | 1034篇 |
1995年 | 1023篇 |
1994年 | 880篇 |
1993年 | 812篇 |
1992年 | 1648篇 |
1991年 | 1590篇 |
1990年 | 1508篇 |
1989年 | 1382篇 |
1988年 | 1257篇 |
1987年 | 1213篇 |
1986年 | 1229篇 |
1985年 | 1224篇 |
1984年 | 945篇 |
1983年 | 793篇 |
1982年 | 695篇 |
1981年 | 599篇 |
1980年 | 521篇 |
1979年 | 780篇 |
1978年 | 594篇 |
1977年 | 526篇 |
1975年 | 497篇 |
1974年 | 557篇 |
1973年 | 516篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Background: In this study we tried to estimate the local surgical trauma in patients undergoing endoscopic or conventional hernia repair
via the changes in peripheral blood T cell subpopulations (i.e., T-helper 1 (TH1) and TH2 cells), recently shown to be recruited
differentially to inflammatory sites.
Methods: Cells were identified flow-cytometrically by intracellular cytokine staining on a single cell level in 30 patients undergoing
conventional (Shouldice) or total extraperitoneal patch (TEPP) hernia repair.
Results: The TH1 cells decreased postoperatively in Shouldice patients on an average of 20.8–31.4%, whereas in TEPP patients only
a minor decline (mean, 7.8–9.2%) was observed. The TH2 cells did not change significantly in TEPP patients, and a small increase
(mean, 7.7%) was detected in Shouldice patients.
Conclusions: Our results suggest that the postoperative reduction in TH1 cells reflects local surgical trauma and can be helpful in evaluating
different surgical procedures. When conventional and endoscopic hernia repair were compared, the latter proved less traumatizing.
Received: 18 March 1998/Accepted: 24 July 1998 相似文献
992.
Morger ID Truttmann AC von Vigier RO Bettinelli A Ramelli GP Bianchetti MG 《Pediatric nephrology (Berlin, Germany)》1999,13(1):50-53
Selective electrodes have been designed for determining plasma ionized magnesium. In kidney disease the relationship between
ionized and total circulating magnesium is often altered. Hence plasma ionized magnesium (ETH 7025 membrane) was determined
in 25 patients with primary renal tubular disorders; 6 patients had total hypomagnesemia. Total plasma magnesium was never
reduced in the remaining 19 patients. Plasma ionized magnesium values were low in the 6 patients with total hypomagnesemia.
In 18 of the 19 patients without total hypomagnesemia plasma ionized magnesium values were not reduced. Ionized hypomagnesemia
was noted in a patient with normal total plasma magnesium in the context of hypercalciuric nephrocalcinosis of unknown origin.
The study demonstrates an excellent concordance between plasma total and ionized magnesium in tubular disorders associated
with total hypomagnesemia and a good concordance in tubular disorders that are not linked with total hypomagnesemia. The determination
of circulating ionized magnesium is of little value in the diagnostic work-up of the vast majority of renal tubular disorders.
The determination might perhaps disclose latent hypomagnesemia in nephrocalcinosis of unknown cause.
Received: 20 March 1998 / Revised: 28 May 1998 / Accepted: 29 May 1998 相似文献
993.
994.
Giant abdominopelvic epithelioid angiomyolipoma associated with tuberous sclerosis: Report of a case
Giorgio Di Matteo Alessandro Maturo Antonella Marzullo Nadia Peparini Bianca Martin Wedard Kenneth Paul Zeri Filippo Maria Di Matteo Domenico Mascagni 《Surgery today》1999,29(11):1183-1188
(Received for publication on July 16, 1998; accepted on Mar. 11, 1999) 相似文献
995.
996.
Tarczy-Hornoch K Martin KA Stratford KJ Jack JJ 《Cerebral cortex (New York, N.Y. : 1991)》1999,9(8):833-843
Recordings were made from pairs of neurons in cat striate visual cortex in vitro to study the AMPA-channel-mediated components of intracortical excitatory synaptic connections between layer 4 spiny neurons and between layer 6 and layer 4 spiny neurons. Forty-six of the 72 cells recorded were identified morphologically. They consisted of spiny stellate and pyramidal cells in layer 4, and pyramidal cells in layer 6. Connections between layer 4 excitatory cells involve excitatory postsynaptic potentials (EPSPs) averaging 949 microV, with an average coefficient of variation of 0.21 (n = 30). The synapses operate at very high release probabilities (0.69-0.98). With repetitive stimulation these EPSPs show varying degrees of depression, largely mediated by presynaptic changes in release probability. Four pairs of layer 4 cells were reciprocally connected. The connections from layer 6 to layer 4 involve smaller, more variable EPSPs, with an average amplitude of 214 microV, and average coefficient of variation 0.72 (n = 7). These synapses operate at moderately high release probabilities (0.37-0.56). They show facilitation with repetitive stimulation, mediated largely by presynaptic changes in release probability. One excitatory connection from a layer 4 neuron to a layer 6 pyramidal cell was also detected. Thus, layer 4 spiny neurons receive effective excitation from two intracortical sources that have different synaptic dynamics and are likely to contribute significantly to the temporal properties of these cells in vivo. 相似文献
997.
998.
999.
It meanwhile is commonly accepted that early onset of specific rehabilitation intervention in traumatic brain injured patients will enhance the recovery of brain function. The integration of neuropsychology in the early treatment of traumatic brain injury can mainly be ascribed to the increasing recognition that cognitive, personality and emotional deficits have been the most devasting longterm problems faced by patients and their families. The aim of our paper is to illustrate the role of neuropsychology in the early stage of rehabilitation. Neuropsychological therapy and the application of appropriate tests depend on the level of consciousness and the extent of behavioural problems. Observation, cognitive screening tests and the use of valid neuropsychological tests make up the main approaches. Our rehabilitation program includes measures of sensory and cognitive stimulation. Improvement of attention and stimulation of cognitive functions are one of the most important aims of early neuropsychological therapy. We choose tasks which require automatic information processing, the retrieval of well established knowledge and implicit learning. Appropriate tests and the development of neuropsychological treatment programmes represent an important means of maximising the patient's capacity to benefit from early rehabilitation. 相似文献
1000.
Direct comparison of projections from the central amygdaloid region and nucleus accumbens shell 总被引:2,自引:0,他引:2
Certain neurochemical and connectional characteristics common to extended amygdala and the nucleus accumbens shell suggest that the two represent a single functional-anatomical continuum. If this is so, it follows that the outputs of the two structures should be substantially similar. To address this, projections from the caudomedial shell and central nucleus of the amygdala, a key extended amygdala structure, were demonstrated in Sprague-Dawley rats with different anterograde axonal tracers processed separately to exhibit distinguishable brown and blue-black precipitates. The caudomedial shell projection is strong in the ventral pallidum and along the medial forebrain bundle through the lateral preopticohypothalamic continuum into the ventral tegmental area, distal to which it thins abruptly. The central nucleus projects strongly to the bed nucleus of the stria terminalis and the sublenticular extended amygdala, but substantially to the lateral hypothalamus only at levels behind the rostral part of the entopeduncular nucleus. Innervation of the ventral tegmental area by the central amygdala is minimal, but the lateral one-third of the substantia nigra, pars compacta and an adjacent lateral part of the retrorubral field receive substantial central amygdala input. Central amygdaloid projections are robust in caudal brainstem sites, such as the reticular formation, parabrachial nucleus, nucleus of the solitary tract and dorsal vagal complex, all of which receive little input from the accumbens. The substantial differences in the output systems of the caudomedial shell of accumbens and central amygdala suggest that the two represent distinct functional-anatomical systems. 相似文献