全文获取类型
收费全文 | 41452篇 |
免费 | 4192篇 |
国内免费 | 2977篇 |
专业分类
耳鼻咽喉 | 251篇 |
儿科学 | 534篇 |
妇产科学 | 496篇 |
基础医学 | 4880篇 |
口腔科学 | 765篇 |
临床医学 | 5282篇 |
内科学 | 6464篇 |
皮肤病学 | 373篇 |
神经病学 | 1806篇 |
特种医学 | 1357篇 |
外国民族医学 | 30篇 |
外科学 | 4604篇 |
综合类 | 7346篇 |
现状与发展 | 10篇 |
一般理论 | 4篇 |
预防医学 | 3000篇 |
眼科学 | 1062篇 |
药学 | 4511篇 |
47篇 | |
中国医学 | 2432篇 |
肿瘤学 | 3367篇 |
出版年
2024年 | 211篇 |
2023年 | 833篇 |
2022年 | 2049篇 |
2021年 | 2567篇 |
2020年 | 1761篇 |
2019年 | 1499篇 |
2018年 | 1457篇 |
2017年 | 1417篇 |
2016年 | 1280篇 |
2015年 | 1875篇 |
2014年 | 2352篇 |
2013年 | 2148篇 |
2012年 | 3006篇 |
2011年 | 3362篇 |
2010年 | 2082篇 |
2009年 | 1769篇 |
2008年 | 2135篇 |
2007年 | 2223篇 |
2006年 | 2020篇 |
2005年 | 1927篇 |
2004年 | 1363篇 |
2003年 | 1344篇 |
2002年 | 1131篇 |
2001年 | 909篇 |
2000年 | 852篇 |
1999年 | 858篇 |
1998年 | 505篇 |
1997年 | 512篇 |
1996年 | 383篇 |
1995年 | 376篇 |
1994年 | 356篇 |
1993年 | 189篇 |
1992年 | 250篇 |
1991年 | 247篇 |
1990年 | 263篇 |
1989年 | 207篇 |
1988年 | 161篇 |
1987年 | 138篇 |
1986年 | 134篇 |
1985年 | 102篇 |
1984年 | 74篇 |
1983年 | 45篇 |
1982年 | 28篇 |
1981年 | 24篇 |
1979年 | 22篇 |
1977年 | 18篇 |
1975年 | 15篇 |
1974年 | 21篇 |
1972年 | 13篇 |
1969年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
A total 37 patients with Crohn's disease who underwent intraoperative endoscopy during resection of the affected intestine were evaluated in this study. The average age of the patients at surgery was 23.2 years. The residual lesions in the remaining intestine identified by intraoperative endoscopy were classified according to their pathologic profiles into three groups: A, B and C. In group A, comprising patients with longitudinal ulcers and/or a cobblestone appearance, 10 of 12 patients had recurrence. In 5 of these 10, the residual lesions were exacerbated and 2 required a further operation. The remaining 5 patients showed recurrence at the site of previous anastomosis and 2 of these 5 required additional surgery.In group B, comprising patients with small ulcers, aphthoid ulcers, or scars, and group C, comprising patients with no residual lesions, recurrence was observed in 13 of 16, and 3 of 9 patients, respectively. The recurrent lesions were all found proximal to, or at the site of previous anastomosis. Additional operations were performed on 3 of the group B patients. The findings of this study revealed that recurrence requiring additional surgery is more frequent at the site of anastomosis, regardless of the endoscopic appearance of the residual lesions. 相似文献
42.
Adultacuteleukemia (AL)isoneofthemostcommonmalignanttumorsofhematology .Withtherecentprogressinchemotherapyandsupportivether apy ,theremissionandsurvivalrateinALhavebeenmarkedlyimproved .However ,drugresistanceandrelapsearestillimportantfactorsaffectinglongsur vivalofthese patients .Theabnormalregulationofcellcycleisanotherfactorthatcannotbeignoredex ceptformultipledrugresistance (MDR) .WedetectcyclinA ,multidrugresistantgene (mdrl) ,topoiso meraseⅡα(TopⅡα)andbcl 2inadultpatientswithA… 相似文献
43.
44.
Meng-Liang Zhou Ji-Xin Shi Chun-Hua Hang Hui-Lin Cheng Xiao-Ping Qi Lei Mao Ke-Fei Chen Hong-Xia Yin 《Journal of cerebral blood flow and metabolism》2007,27(9):1583-1592
Nuclear factor-kappaB (NF-kappaB) plays a key role in inflammation, which is involved in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). In the present study, we assessed the potential role of NF-kappaB in regulation of cerebral vasospasm. Nuclear factor-kappaB DNA-binding activity was measured in cultured vascular smooth muscle cells (VSMCs) treated with hemolysate and pyrrolidine dithiocarbamate (PDTC, 80 micromol/L), an inhibitor of NF-kappaB. Forty-two rabbits were divided into three groups: control, SAH, and PDTC groups (n=14 for each group). The caliber of the basilar artery was evaluated. Nuclear factor-kappaB DNA-binding activity and the gene expression levels of cytokines and adhesion molecules in the basilar artery were measured. Immunohistochemical study was performed to assess the expression and localization of tumor necrosis factor (TNF)-alpha, intercellular adhesion molecule (ICAM)-1, and myeloperoxidase (MPO). It was observed that NF-kappaB DNA-binding activity was significantly increased by treatment with hemolysate in cultured VSCMs, but this increase was suppressed by pretreatment with PDTC. Severe vasospasm was observed in the SAH group, which was attenuated in the PDTC group. Subarachnoid hemorrhage could induce increases of NF-kappaB DNA-binding activity and the gene expression levels of TNF-alpha, interleukin (IL)-1 beta, ICAM-1, and vascular cell adhesion molecule (VCAM)-1, which were reduced in the PDTC group. Immunohistochemical study demonstrated that the expression levels of TNF-alpha, ICAM-1, and MPO were all increased in the SAH group, but these increases were attenuated in the PDTC group. Our results suggest that NF-kappaB is activated in the arterial wall after SAH, which potentially leads to vasospasm development through induction of inflammatory response. 相似文献
45.
益肾化浊注射液对慢性肾功能衰竭大鼠残余肾中细胞因子含量的影响 总被引:2,自引:0,他引:2
通过观察益肾化浊注射液对5/6肾切除大鼠残余肾中细胞因子含量的影响,益肾化浊注射液延缓慢性肾功能衰竭(CRF)模型大鼠肾功能减退的作用机理。结果显示:益肾化浊注射液可以降低5/6肾切在鼠血清肌,尿素氮(P<0.01),下调肾组织中白细胞介素-1(IL-1)(P<0.05),白细胞介素-8(IL-8)(P<0.05)及肿瘤坏死因子(TNF)(P<0.05)的总体水平,说明益肾化浊注射液可以通过下调5/6肾切除大鼠残余肾中相关细胞因子含量,抑制促炎细胞因子对肾脏的损害,从而延缓CRF的进展。 相似文献
46.
47.
恶性肿瘤的皮肤转移确与患者的病种、病理类型、术前后淋巴结转移情况、临床分期、手术类型、放疗及化疗的剂量、遗传因素有关。其出现于任何部位均提示预后不佳。 相似文献
48.
49.
S T Bartlett W J McCarthy A S Palmer W R Flinn J J Bergan J S Yao 《Archives of surgery (Chicago, Ill. : 1960)》1988,123(8):1004-1008
Beh?et's disease is characterized by recurrent ulcers of the mouth and genitalia and relapsing iritis. It is now recognized as a chronic multisystem disease affecting the skin, mucous membranes, eye, joints, central nervous system, and blood vessels. One of the known vascular complications of Beh?et's disease is aneurysm formation or venous thrombosis. The two patients with Beh?et's disease in this report developed multiple aneurysms over a short time span. Vascular surgeons dealing with young adults with peripheral aneurysms must be aware of this uncommon yet challenging clinical entity. 相似文献
50.
BACKGROUND: At present, researches on differentiating from human adipose-derived adult stromal cells (hADASC) to neuron-like cells are focus on inducing by artificial-synthetic compound solution; however, hippocampal astrocyte conditioned medium (HCAM) can induce in vitro differentiation from hADASC to neuron-like cells is still unclear.
OBJECTIVE: To observe whether HCAM can induce in vitro differentiation from hADASC to neuron-like cells.
DESIGN: Randomized control study.
SETTING: Department of Neurology, Taixing People's Hospital; Central Laboratory, North China Coal Medical College.
MATERIALS: Donor of adipose tissue was donated by female volunteers suffering from caesarean section in the department of obstetrics & gynecology in our hospital and aged 20-35 years. Adipose tissue was collected from subcutaneous tissue of abdomen during the operation. In addition, 8 male newborn Wistar rats within 24 hours with average body mass of 20 g were provided by Animal Institute of Chinese Academy of Medical Sciences. Rabbit-anti-human Nestin polyclonal antibody, rabbit-anti-human glial fibriliary acidic protein (GFAP) polyclonal antibody, rabbit-anti-human neuro-specific enolase polyclonal antibody and mouse-anti-human microtubal associated protein 2 (MAP-2) polyclonal antibody were provided by Wuhan Boster Company.
METHODS: The experiment was carried out in the Central Laboratory of North China Coal Medical College from October 2004 to June 2005. hADASC was cultured with HCAM and its growth and morphological changes were observed under inverted phase contrast microscope. Immunocytochemistry, immunofluorescence and Western blotting were used to evaluate the expressions of Nestin, which was a specific sign of nerve precursor, neuro-specific enolase and MAP-2, which was a specific sign of nerve cell, and GFAP, which was a specific sign of neuroglial cells.
MAIN OUTCOME MEASURES: Nestin, which was a specific sign of nerve precursor, neuro-specific enolase and MAP-2, which was a specific sign of nerve cell, and GFAP, which was a specific sign of neuroglial cells.
RESULTS: On the 3rd day of culture, partial hADASC started deformation from slender shuttle-shape cells to neuron-like cells. It suggested that cells stretched out apophysis, which were mainly double-pole or multiple-pole cells. Five days later, immunohistochemical detection suggested that expression of Nestin (10.5±0.037) was found out in cells; meanwhile, expressions of GFAP (38.4±0.052) and neuro-specific enolase (NSE) (15.7±0.023) were also found out in cells; however, expression of MAP-2 was not observed. Western blot indicated that, 5 days after effect of HCAM, Nestin was found out in hADASC; meanwhile, expressions of GFAP and neuro-specific enolase were also found out; however, expression of MAP-2 was not observed.
CONCLUSION: HCAM can induce the differentiation from hADASC to neuron-like cells in vitro. 相似文献