全文获取类型
收费全文 | 1776篇 |
免费 | 233篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 88篇 |
妇产科学 | 27篇 |
基础医学 | 140篇 |
口腔科学 | 12篇 |
临床医学 | 253篇 |
内科学 | 336篇 |
皮肤病学 | 31篇 |
神经病学 | 137篇 |
特种医学 | 165篇 |
外科学 | 369篇 |
综合类 | 67篇 |
现状与发展 | 20篇 |
一般理论 | 5篇 |
预防医学 | 123篇 |
眼科学 | 29篇 |
药学 | 66篇 |
中国医学 | 4篇 |
肿瘤学 | 136篇 |
出版年
2023年 | 42篇 |
2021年 | 21篇 |
2020年 | 27篇 |
2019年 | 16篇 |
2018年 | 61篇 |
2017年 | 50篇 |
2016年 | 39篇 |
2015年 | 48篇 |
2014年 | 54篇 |
2013年 | 101篇 |
2012年 | 40篇 |
2011年 | 51篇 |
2010年 | 54篇 |
2009年 | 77篇 |
2008年 | 54篇 |
2007年 | 46篇 |
2006年 | 49篇 |
2005年 | 43篇 |
2004年 | 52篇 |
2003年 | 36篇 |
2002年 | 43篇 |
2001年 | 48篇 |
2000年 | 44篇 |
1999年 | 54篇 |
1998年 | 35篇 |
1997年 | 40篇 |
1996年 | 55篇 |
1995年 | 37篇 |
1994年 | 27篇 |
1993年 | 27篇 |
1992年 | 35篇 |
1991年 | 48篇 |
1990年 | 36篇 |
1989年 | 38篇 |
1988年 | 48篇 |
1987年 | 46篇 |
1986年 | 47篇 |
1985年 | 45篇 |
1984年 | 21篇 |
1983年 | 29篇 |
1982年 | 20篇 |
1981年 | 11篇 |
1980年 | 17篇 |
1979年 | 26篇 |
1978年 | 20篇 |
1977年 | 24篇 |
1976年 | 17篇 |
1975年 | 16篇 |
1974年 | 11篇 |
1971年 | 11篇 |
排序方式: 共有2026条查询结果,搜索用时 31 毫秒
11.
Seminal analysis was performed within 2 months of orchiectomy on 97 patients with clinical Stage I malignant testicular teratoma managed by surveillance following orchiectomy. Relapse of malignant disease occurred in 28% of 47 patients with a sperm count less than 10 X 10(6)/ml and in 32% of 50 patients with a sperm count greater than or equal to 10 X 10(6)/ml. Of 11 patients with azoospermia, 4 relapsed and 1 developed contralateral testicular germ cell tumour. Of 35 patients with malignant teratoma undifferentiated the relapse rate was 68% in 16 patients with a sperm count less than 10 X 10(6)/ml and 42% in 19 patients with a sperm count greater than or equal to 10 X 10(6)/ml. It was concluded that sperm count analysis is non-contributory in estimating the risk of relapse in clinical Stage I teratoma. 相似文献
12.
Binding and retrograde transport of leukemia inhibitory factor by the sensory nervous system. 总被引:5,自引:0,他引:5
I A Hendry M Murphy D J Hilton N A Nicola P F Bartlett 《The Journal of neuroscience》1992,12(9):3427-3434
Leukemia inhibitory factor (LIF), a peptide growth factor with multiple activities, has recently been shown to support the generation and survival of sensory neurons in cultures of mouse neural crest and dorsal root ganglia (DRG). We have conducted binding experiments with 125I-LIF on cultures of DRG to determine the receptor distribution for LIF on these cells and found that at least 60% of the sensory neurons in the cultures bound 125I-LIF, all of which could be eliminated by the addition of unlabeled LIF. The other cells in the culture, which morphologically appeared to be Schwann cells, did not bind appreciable quantities of 125I-LIF. In order to investigate whether LIF is retrogradely transported to sensory neurons in vivo, 125I-LIF was injected into the footpads and gastrocnemius muscles of newborn and adult mice, following sciatic nerve ligation. Radioactivity accumulated in the distal portion of the sciatic nerve, indicating retrograde transport of LIF. Subsequent experiments on mice with unligated sciatic nerves showed that 125I-LIF is specifically transported into the sensory neurons of the DRG. There was no apparent transport of 125I-LIF into motor neurons in the spinal cord. These experiments demonstrate that LIF can specifically bind to and be transported by sensory neurons and further support the idea that LIF acts as a target-derived neurotrophic factor, analogous to NGF. 相似文献
13.
14.
A monoclonal antibody capable of blocking the biological activity of the ciliary neurotrophic factor purified from bovine cardiac muscle has been produced. This antibody, when administered perinatally to mice, causes a failure of the normal development of the parasympathetic innervation of the iris as determined by assay for the activity of the cholinergic marker enzyme choline acetyltransferase. The same treatment has no effect on the adrenergic neuronal marker, tyrosine hydroxylase. This immunoparasympathectomy suggests that the ciliary neurotrophic factor has an essential role in regulating the development of the mammalian parasympathetic nervous system. 相似文献
15.
Although myocardial toxicity of certain antibiotics has been suggested by animal studies, their effects on human cardiac muscle has not been established. Accordingly, human right atrial trabeculae contracting isometrically in vitro were exposed to increasing doses of the antibiotics gentamicin, tobramycin and cephalothin. Contractile responses were measured and dose-response curves calculated by a polynomial regression analysis. All three antibiotics demonstrated a dose-related decrease in relative developed force although resting force remained constant. Concentrations of gentamicin, tobramycin and cephalothin that caused 50% depression of developed force were 1.97, 1.92 and 52.75 mg/mL, respectively. These doses were 200, 200 and 2600 times the accepted serum toxic concentrations for gentamicin, tobramycin and cephalothin, respectively. The depression caused by cephalothin is probably related to ionic changes within the bath solution. In conclusion, gentamicin and tobramycin have myocardial toxicity at high concentrations which should not occur clinically when used judiciously. 相似文献
16.
17.
Residual damage in haemopoietic progenitor cell populations, spleen and granulocyte-macrophage colony-forming cells (CFU-S and GM-CFC) was detected in mice after 15 daily fractions where the dose per fraction was as low as 0.1 Gy. The injury was dose-dependent and after higher total fractionated doses of 7.5-10 Gy the CFU-S population recovered to about 50% of control between 2 and 12 months after irradiation. Residual damage was also detected in the stroma, in the form of reduced numbers of fibroblastoid colony-forming cells and of CFU-S in ossicles under the kidney capsule. The response to a second course of 15 fractions, given 3 weeks after the end of the first course, was similar and additive to the response to the first course in the short term. However, in the long term, recovery levels were similar after either one or two courses. 相似文献
18.
Somatostatin: evidence for a role in thermal nociception 总被引:5,自引:0,他引:5
In barbiturate-anaesthetized spinalized cats, antibody microprobes were used to investigate the release of immunoreactive somatostatin (irSS) in the lumbar dorsal horn in response to cutaneous stimuli. In the absence of applied stimulation, a significant basal release of irSS was present in the region of the substantia gelatinosa. Such release was not increased by innocuous or noxious cutaneous mechanical stimuli nor by innocuous thermal stimuli, but was increased by noxious thermal stimulation. The magnitude of this noxious heat-evoked release was estimated by comparing in vivo microprobes with those used to detect known concentrations of somatostatin in vitro. Pairs of microprobes were used to detect simultaneous release of both irSS and immunoreactive substance P in the substantia gelatinosa. The results support the putative role of somatostatin in the spinal transmission of thermal nociceptive information. 相似文献
19.
The computerized database system described was initially developed in 1986 to facilitate analysis of retrospective head and neck cancer data from the Royal Adelaide Hospital Department of Otolaryngology. This has now been expanded to become an on-going patient information management system. It is based on the dBase-III-Plus database package and is implemented on an IBM XT compatible computer. The system was designed to be used by staff without specialist computer skills and is therefore largely “menu-driven.” The main functions include patient record creation, update, and retrieval, and the production of reports including graphical presentations. There is also a powerful but easy to use query facility. The system has already provided much useful epidemiological material but is now beginning to fulfill an even more important role in patient follow-up and in assisting evaluation of alternative treatment protocols. 相似文献
20.
Differential Calcium Binding Protein Immunoreactivity Distinguishes Classes of Relay Neurons in Monkey Thalamic Nuclei 总被引:5,自引:0,他引:5
The distributions of neurons displaying immunoreactivity for two calcium binding proteins, parvalbumin and 28Kd calbindin, were studied in the thalamus of M. fascicularis. Colocalization experiments were carried out to determine the extent to which parvalbumin- and calbindin-like immunoreactivity was found in the same cells and the extent to which either was localized in GABAergic interneurons. Anterograde and retrograde tracing experiments involving the fluorescent tracer, fast blue, were also used to determine that cells expressing the calcium binding proteins projected upon the cerebral cortex. In the dorsal thalamus, nuclei are distinguished by different patterns of parvalbumin-like and calbindin-like immunoreactivity. In certain nuclei, for example the lateral dorsal and anterior pulvinar, neurons express immunoreactivity for only one of the calcium binding proteins. In others, neurons in different layers, for example the dorsal lateral geniculate nucleus, or in different compartments, for example the intralaminar nuclei, express immunoreactivity for either parvalbumin or calbindin; in other nuclei, for example the ventral group, neurons are mixed and immunoreactivity for parvalbumin and calbindin is commonly colocalized. In the ventral thalamus and epithalamus, similar patterns are observed. Colocalization of parvalbumin- and GABA-immunoreactivity is found in all cells of the reticular nucleus but only in certain cells in selected nuclei of the dorsal thalamus, namely the dorsal lateral geniculate and magnocellular medial geniculate. No calbindin-positive cells are also GABA-positive. Most parvalbumin and/or calbindin positive cells in the dorsal thalamus project to the cerebral cortex, as indicated by the retrograde tracing studies, and many parvalbumin positive fibres entering the cerebral cortex could also be shown to contain fast blue anterogradely transported from a thalamic injection. Most of the major sensory and motor pathways entering the dorsal thalamus express parvalbumin immunoreactivity. The optic tract also expresses calbindin immunoreactivity but most other calbindin positive fibres entering the thalamus ascend in the midbrain tegmentum. The differential distributions of parvalbumin and calbindin implied by these results suggest that thalamic cells belonging to different functional systems and projecting differentially upon the cerebral cortex can be distinguished by differential expression of these or closely related calcium binding proteins. This may yield clues to their differential responsivity to afferent driving. 相似文献