全文获取类型
收费全文 | 15997篇 |
免费 | 1386篇 |
国内免费 | 1229篇 |
专业分类
耳鼻咽喉 | 159篇 |
儿科学 | 186篇 |
妇产科学 | 138篇 |
基础医学 | 2137篇 |
口腔科学 | 253篇 |
临床医学 | 2082篇 |
内科学 | 2475篇 |
皮肤病学 | 114篇 |
神经病学 | 975篇 |
特种医学 | 559篇 |
外国民族医学 | 15篇 |
外科学 | 1624篇 |
综合类 | 2569篇 |
现状与发展 | 1篇 |
一般理论 | 2篇 |
预防医学 | 1128篇 |
眼科学 | 528篇 |
药学 | 1504篇 |
22篇 | |
中国医学 | 714篇 |
肿瘤学 | 1427篇 |
出版年
2024年 | 44篇 |
2023年 | 255篇 |
2022年 | 592篇 |
2021年 | 844篇 |
2020年 | 604篇 |
2019年 | 512篇 |
2018年 | 551篇 |
2017年 | 515篇 |
2016年 | 472篇 |
2015年 | 763篇 |
2014年 | 831篇 |
2013年 | 753篇 |
2012年 | 1119篇 |
2011年 | 1285篇 |
2010年 | 729篇 |
2009年 | 637篇 |
2008年 | 892篇 |
2007年 | 900篇 |
2006年 | 829篇 |
2005年 | 943篇 |
2004年 | 554篇 |
2003年 | 502篇 |
2002年 | 446篇 |
2001年 | 357篇 |
2000年 | 419篇 |
1999年 | 402篇 |
1998年 | 277篇 |
1997年 | 234篇 |
1996年 | 177篇 |
1995年 | 177篇 |
1994年 | 155篇 |
1993年 | 134篇 |
1992年 | 124篇 |
1991年 | 122篇 |
1990年 | 89篇 |
1989年 | 82篇 |
1988年 | 65篇 |
1987年 | 64篇 |
1986年 | 51篇 |
1985年 | 40篇 |
1984年 | 15篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 3篇 |
1979年 | 9篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
慢性粒细胞白血病100例骨髓组织病理学Hannover分类法意义探讨 总被引:2,自引:0,他引:2
本文对100例慢性粒细胞白血病(CML)患者进行组织病理学研究,应用Hannover国际分类法进行分类,观察到骨髓组织病理学中巨核细胞增多者临床症状较重,中位生存时间较短,认为该分类法对临床及预后判断有指导意义,比既往应用的Bartl及Frisch分类法优越。 相似文献
42.
原发性单纯性脑干出血52例临床研究 总被引:1,自引:0,他引:1
目的研究原发性单纯性脑干出血的病因、诊断、治疗、预后及预防。方法对52例原发性单纯性脑干出血的临床资料进行回顾性分析。结果预后良好25例,优良率为48.1%;死亡21例,死亡率40.4%;出血量≤5.0ml死亡率21.9%(7/32),出血量≥5.1ml死亡率70.0%(14/20),出血量〉10.0ml 10例全部死亡。结论原发性单纯性脑干出血发病急,病情重,死亡率高,预后差;高血压为本病的主要发病原因;CT是原发性单纯性脑干出血的安全、可靠诊断方法;适时进行气管切开及亚低温治疗能有效提高疗效及降低死残率;严格控制血压是预防原发性单纯性脑干出血的重要措施。 相似文献
43.
Mano J. Thubrikar Michel R. Labrosse Kenton J. Zehr Francis Robicsek Geoffrey G. Gong Brett L. Fowler 《European journal of cardio-thoracic surgery》2005,28(6):850-855
Objective: Valve-sparing surgery can be used in patients with dilated aortic roots and aortic insufficiency (AI) but has not become a common practice, in part because the spared valve may be incompetent. Our goal was to study how the dimensions of the aortic root and leaflets have changed in such patients. Methods: Fourteen patients with dilated aortic root and AI were examined by transesophageal echocardiography. The annulus diameter, sinotubular junction (STJ) diameter, sinus height, leaflet free-edge length, and leaflet height were measured. Correlations among these dimensions and with the AI grades were explored. Measurements were also made in 19 normal human aortic valves from silicone molds. Results: There was no evident change in the average diameter of the annulus between the normal valves and those in the dilated aortic roots. The STJ diameter was obviously increased in the dilated aortic roots; the aortic sinuses also appeared to be taller and the leaflets larger than normal. The leaflet free-edge length, the leaflet height, and the sinus height were found to increase with the dilated STJ diameter. The degree of AI was not found to correlate well with any of the dimensions measured. Conclusions: The dimensions of the leaflets may change parallel to aortic root dilatation with AI. Therefore, during valve sparing, it may be necessary to correct both the dilatation of the root and the leaflet free-edge length to achieve a competent valve. 相似文献
44.
报告37例主动脉窦瘤破裂手术治疗结果。着重介绍手术方法,主张采用主动脉根部和窦瘤破入心腔的双切口,切除、修补窦瘤的同时矫正合并畸形。伴主动脉瓣膜垂致中度关闭不全者,主张行主动脉瓣替换术。术后早期死亡1例,余35例随访6个月-14年,心功能恢复良好。 相似文献
45.
杨红 《中华中西医学杂志》2007,5(6):1-1
目的评价米非司酮用于保守治疗异位妊娠的疗效。方法所选病例均住院治疗,予口服米非司酮50mg,每天两次,连服6天,定期复查B超和测定血p—HCG水平以观察疗效。结果68例异位妊娠患者的治疗,治愈46例,治愈率67.7%。结论米非司酮保守治疗异位妊娠疗效确切,副作用小。 相似文献
46.
J P Kinsella D R Gerstmann A K Gong A F Taylor R A deLemos 《Biology of the neonate》1991,60(5):283-291
We studied the hemodynamic effects of using natural surfactant in premature baboons with hyaline membrane disease (HMD). Study animals (n = 5) received a single dose of surfactant immediately after delivery and control animals (n = 8) did not. Using microspheres at 3, 8, and 23 h we found no significant differences in left ventricular output, effective systemic flow, systemic-to-pulmonary patent ductus arteriosus (PDA) shunting, or in cerebral or renal organ blood flow. However, both groups had large PDA shunts (fraction of LVO to lungs greater than 0.40-0.55 at 3 and 8 h) resulting in low systemic perfusion (less than 80 ml/min/kg). Single dose surfactant did not improve the myocardial dysfunction and low cerebral and renal blood flow which occur during treatment for HMD. 相似文献
47.
二步冷冻保存同种异体骨-ACL-骨移植后排斥反应的影响 总被引:3,自引:0,他引:3
目的 :探讨新鲜异体和二步冷冻保存同种异体骨 前交叉韧带 (ACL) 骨移植后排斥反应的差异。方法 :将 6 0只新西兰兔和 6 0只日本大耳兔分别随机分成自体骨 ACL 骨移植组、新鲜异体骨 ACL 骨移植组和二步冷冻保存同种异体骨 ACL 骨移植组 ,分别于术前及术后 1周、2周、3周、4周各采血 2ml测定血清中白细胞介素 2 (IL 2 )水平 ,术后 4周、12周切取移植关节 ,作苏木精 -伊红染色。结果 :光镜下检查显示 ,自体移植组和二步冷冻保存移植组均未见明显炎性细胞浸润 ,胶原排列规则 ,分化成熟。新鲜异体移植组有大量淋巴细胞浸润 ,其IL 2水平明显高于自体移植组和二步冷冻保存同种异体移植组且高于术前水平 (P <0 .0 1)。结论 :二步冷冻减轻了同种异体骨 ACL 骨移植后排斥反应 ,移植后其组织学改变同自体移植相似 相似文献
48.
昆明种小鼠56只,在两个海拔高度上(300m和5000m)各分为两个组(对照组和复合组),分别给予相应的处理因素后,检测其血浆ANP水平和游泳时间。结果表明,小鼠在海拔5000m生活48h后,其血浆ANP较海拔300m小鼠降低52.87%,而其游泳时间则增长91.59%;在两个海拔高度上,复合组血浆ANP都较对照组降低,而游泳时间都长于对照组.提示复合方案提高高原劳动能力的机理,可能与降低体内血浆ANP水平有关。 相似文献
49.
Is neurogenesis reparative after status epilepticus? 总被引:1,自引:0,他引:1
50.
Proteolytic Processing Mechanisms in the Biosynthesis of Neuroendocrine Peptides: The Subtilisin-like Proprotein Convertases 总被引:1,自引:0,他引:1
Yves Rouill Stephen J. Duguay Kaare Lund Machi Furuta Qiuming Gong Gregory Lipkind Anthony A. Oliva Jr. Shu Jin Chan Donald F. Steiner 《Frontiers in neuroendocrinology》1995,16(4)
The recent discovery of a novel family of precursor processing endoproteases has greatly accelerated progress in understanding the complex mechanisms underlying the maturation of prohormones, neuropeptides, and many other precursor-derived proteins. At least six members of this family have been found thus far in mammalian species, several having alternatively spliced isoforms, and related enzymes have been identified in many invertebrates, including molluscs, insects, nematodes, and coelenterates. The proprotein convertases are all dependent on calcium for activity and all possess highly conserved subtilisin-like domains with the characteristic catalytic triad of this serine protease (ordered Asp, His, and Ser along the polypeptide chain). Two members of this family, PC2(SPC2) and PC1/PC3(SPC3), appear to play a preeminent role in neuroendocrine precursor processing. Both convertases are expressed only in the brain and in the extended neuroendocrine system, while another important family member—furin/PACE (SPC1)—is expressed more ubiquitously, in almost all tissues, and at high levels in liver. SPC2 and SPC3 exhibit acidic pH optima and other properties which enhance their activity in the acidic, calcium-enriched environment of the dense-core secretory granules of the regulated pathway in neuroendocrine cells, while furin has a neutral pH optimum and is localized predominantly to the trans Golgi network where it is retained by a C-terminal transmembrane domain. Furin processes a wide variety of precursors in the constitutive pathway, such as those of growth factors, receptors, coagulation factors, and viral glycoproteins. Recent findings on the processing of proopiomelanocortin, proinsulin, proglucagon, and several other neuroendocrine precursors by SPC2 and SPC3 are discussed, along with information on the structure, properties, evolution, developmental expression, and regulation or the convertases. An inherited defect in the fat/fat mouse which affects the processing of proinsulin, and probably also many other prohormones, due to a point mutation in carboxypeptidase E has recently been identified and has begun to provide new insights into the functional integration of the individual processing steps. 相似文献