全文获取类型
收费全文 | 83749篇 |
免费 | 7652篇 |
国内免费 | 4293篇 |
专业分类
耳鼻咽喉 | 1047篇 |
儿科学 | 1379篇 |
妇产科学 | 954篇 |
基础医学 | 8873篇 |
口腔科学 | 1540篇 |
临床医学 | 10211篇 |
内科学 | 12151篇 |
皮肤病学 | 1903篇 |
神经病学 | 3751篇 |
特种医学 | 3795篇 |
外国民族医学 | 22篇 |
外科学 | 7764篇 |
综合类 | 13744篇 |
现状与发展 | 17篇 |
一般理论 | 4篇 |
预防医学 | 7006篇 |
眼科学 | 1832篇 |
药学 | 9162篇 |
80篇 | |
中国医学 | 4914篇 |
肿瘤学 | 5545篇 |
出版年
2024年 | 258篇 |
2023年 | 1085篇 |
2022年 | 2752篇 |
2021年 | 3817篇 |
2020年 | 2831篇 |
2019年 | 2462篇 |
2018年 | 2563篇 |
2017年 | 2589篇 |
2016年 | 2622篇 |
2015年 | 4087篇 |
2014年 | 5136篇 |
2013年 | 5461篇 |
2012年 | 7880篇 |
2011年 | 7990篇 |
2010年 | 5854篇 |
2009年 | 4903篇 |
2008年 | 5635篇 |
2007年 | 5207篇 |
2006年 | 4841篇 |
2005年 | 4144篇 |
2004年 | 2950篇 |
2003年 | 2557篇 |
2002年 | 2180篇 |
2001年 | 1303篇 |
2000年 | 1025篇 |
1999年 | 764篇 |
1998年 | 412篇 |
1997年 | 455篇 |
1996年 | 305篇 |
1995年 | 282篇 |
1994年 | 251篇 |
1993年 | 157篇 |
1992年 | 176篇 |
1991年 | 161篇 |
1990年 | 117篇 |
1989年 | 77篇 |
1988年 | 68篇 |
1987年 | 53篇 |
1986年 | 39篇 |
1985年 | 29篇 |
1984年 | 34篇 |
1983年 | 19篇 |
1982年 | 9篇 |
1981年 | 14篇 |
1980年 | 17篇 |
1979年 | 15篇 |
1978年 | 9篇 |
1974年 | 11篇 |
1972年 | 10篇 |
1971年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Hao Cheng Zhongyao Wu Jianliang Zheng Guilan Lu Jianhua Yan Min Liu Danping Huang Jianxian LinZhongshan Ophthalmic Center Sun Yat-sen University Guangzhou China 《眼科学报》2003,19(1):54-59
Purpose: To study the changes of telomerase activity and cytotoxic effects by Cisplatin; cis-dichlorodiamine platinum (CDDP) in cultured human choroidal melanoma. Material and Methods: The primary cultured human choroidal melanoma cells were cultured in the presence and absence of CDDP with different concentration and time respectively. The toxic effects were evaluated by MTT and the level of telormarse was detected by PCR-ELISA assay. And the relationship between telomerase activity and cytotoxic effects were analyzed by a correlation analysis.Results: Following the increase of the concentration and the time of CDDP, gradually repressed telomerase activity was detected in cultured cells. Meanwhile, the restrain rate of the cells increased. The telomerase activity at 24h and 1μg/ml was repressed significantly compared with the control cells. However, the appearance of cell death lagged behind the decreasing of telomerase.Conclusions: CDDP is an effective telomerase inhibitor in cultured choroidal melan 相似文献
43.
目的:分析肾移植后免疫抑制剂对长期存活的影响,寻找移植后不同时间合适的免疫抑制用药方案及其用药剂量。 方法:对肾移植一年以上、肾功能正常的497例患者进行5年连续随访。根据移植后2、3、5年的不同免疫抑制用药将患者分为三联、二联、传统二联治疗三组。统计各组的排异发生率,排异和无排异患者免疫抑制用药的种类、剂量及CsA浓度,对排异患者追踪排异发生前12个月内的药物更动情况。 结果:肾移植后2、3、5 相似文献
44.
45.
46.
H. Nishino Y. Oomura Z. Kardi S. Aou L. Lnrd Y. Kai A. Fukuda C. Ito B.I. Min C.P. Salamant 《Brain research bulletin》1988,20(6):839-845
Single neuron activities in the lateral hypothalamic area (LHA) were recorded during bar press feeding task in the monkey. First registered neurons were sorted into 2 groups, glucose-sensitive (GS) and glucose-insensitive (GIS) neurons, depending on their glucose sensitivity. Then firing variations to feeding, electrophoretically applied catecholamines and opiate, and to odor and taste stimuli were investigated. GS neurons responded to dopamine, noradrenaline and morphine more often than GIS neurons. In feeding task GS neurons responded during bar press (BP) and reward (RW) periods with long-lasting inhibition of firing and at cue tone (CT) with transient inhibition, while GIS neurons responded during BP and RW periods mainly with excitation and at cue light (CL) with excitation. A majority of GS neurons responded to both odor and taste stimuli more often than GIS neurons. Data suggest that these two kinds of neurons in the LHA may be involved in different functional aspects of feeding: GS neurons, mainly in internal information processing and reward mechanism, and GIS neurons, in external information processing and motor aspects. 相似文献
47.
Anatomic and spiral computed tomographic study of the genial tubercles for genioglossus advancement.
Shan Kai Yin Hong Liang Yi Wen Ying Lu Jian Guan Hong Min Wu Zhen Yu Cao Dong Zhen Yu Yan Yan Huang Chun Gen Wu 《Otolaryngology--head and neck surgery》2007,136(4):632-637
OBJECTIVE: To measure and compare Chinese mandibular genial tubercles measured anatomically and with computed tomography (CT). STUDY DESIGN AND SETTING: Spiral CT scans were taken of 40 adult human skulls; the superior genial spines were measured using anatomic and CT methods. RESULTS: The height and width of the superior genial spines, mandible thickness, and distance from the menton to the inferior and superior margins of the superior genial spines were 5.82 +/- 0.71, 6.98 +/- 1.35, 11.95 +/- 1.59, 11.08 +/- 2.05, and 16.91 +/- 2.30 mm from anatomic measurements and 6.17 +/- 0.71, 7.01 +/- 1.13, 12.19 +/- 1.64, 10.41 +/- 1.55, and 15.73 +/- 2.12 mm using spiral CT, respectively. The anatomic and CT measurements were correlated. CONCLUSION: Spiral CT of the genial tubercles can help locate the osteotomy in genioglossus advancement. SIGNIFICANCE: This study acquired reference data on Chinese genial tubercles demonstrating that CT measurements of the genial tubercles reflect their anatomy, which should allow accurately locate the osteotomy. 相似文献
48.
The role of cytokines in rhinosinusitis 总被引:1,自引:0,他引:1
Since the last decade, new insights into inflammatory processes have become possible by investigating the pattern of cytokines in acute and chronic sinus diseases. This review aims to update and discuss the findings of in vitro and in vivo studies concerning the role of cytokines in sinusitis and nasal polyposis. The proinflammatory cytokines interleukin-1beta, interleukin-6 and the neutrophil-chemoattractant interleukin-8 may play a major role in acute sinusitis, as shown in viral and allergic rhinitis. In chronic sinusitis interleukin-3 dominates the cytokine profiles, giving support to a variety of inflammatory cells. Interleukin-5 is a key protein in the pathogenesis of nasal polyposis. Activation and survival of eosinophils in nasal polyps are thought to be regulated by interleukin-5. Further investigation of cytokine expression patterns in inflammatory sinus diseases will lead to a better understanding of their pathogenesis and to a development of new therapeutic modality. 相似文献
49.
Genetic imbalances in pleomorphic xanthoastrocytoma detected by comparative genomic hybridization and literature review. 总被引:2,自引:0,他引:2
Xiao-Lu Yin Angela Bik-Yu Hui Eleanore C Liong Min Ding Alex R Chang Ho-Keung Ng 《Cancer Genetics and Cytogenetics》2002,132(1):14-19
Pleomorphic xanthoastrocytoma (PXA) is a rare, low-grade astrocytic tumor found in the central nervous system. Histologically, the tumor is characterized by markedly pleomorphic and lipidized cells. Although most of the patients have a favorable prognosis, a small number of cases undergoing recurrence or progression to anaplastic astrocytoma were reported. Very few genetic studies have been performed on PXA because of its rarity and the pathogenesis of this neoplasm is largely unknown. In order to provide an overview of genetic alterations in PXA, we performed comparative genomic hybridization to identify chromosomal imbalances (DNA gains and losses) in three cases of PXA. Genetic imbalance was detected on at least one chromosome for each case. One case, which revealed multiple genetic alterations, showed a poor prognosis. DNA gain on chromosome 7 and loss on 8p were demonstrated in two of three cases, suggesting that the candidate gene(s) located on these regions may play a role in the development of PXA. Further studies are needed to identify the residing candidate genes that are involved in the tumorigenesis of PXA. In addition, the histopathological features and previous genetic studies on PXA are reviewed. 相似文献
50.
Recent evidence points to the fact that osteoclasts are derived from mononuclear cells of hematopoietic bone marrow. In this study we have examined the formation of osteoclasts from mononuclear cells in vitro. The mononuclear cells were isolated after 7 days from cultures of mouse bone marrow cells. The isolated cells were co-cultured with osteoclast-free, fetal-mouse calvaria. After 10 to 14 days of co-culture, multinucleated cells which have all the characteristics of osteoclasts were found in juxtaposition to seams of woven bone. These data strongly suggest that bone marrow mononuclear cells, when suitably induced, can give rise to osteoclasts in vitro. 相似文献