全文获取类型
收费全文 | 11052篇 |
免费 | 737篇 |
国内免费 | 265篇 |
专业分类
耳鼻咽喉 | 477篇 |
儿科学 | 114篇 |
妇产科学 | 85篇 |
基础医学 | 934篇 |
口腔科学 | 344篇 |
临床医学 | 969篇 |
内科学 | 833篇 |
皮肤病学 | 40篇 |
神经病学 | 1471篇 |
特种医学 | 287篇 |
外科学 | 3159篇 |
综合类 | 1384篇 |
预防医学 | 614篇 |
眼科学 | 107篇 |
药学 | 682篇 |
7篇 | |
中国医学 | 160篇 |
肿瘤学 | 387篇 |
出版年
2024年 | 32篇 |
2023年 | 212篇 |
2022年 | 418篇 |
2021年 | 527篇 |
2020年 | 543篇 |
2019年 | 430篇 |
2018年 | 407篇 |
2017年 | 459篇 |
2016年 | 462篇 |
2015年 | 431篇 |
2014年 | 852篇 |
2013年 | 879篇 |
2012年 | 633篇 |
2011年 | 655篇 |
2010年 | 602篇 |
2009年 | 637篇 |
2008年 | 508篇 |
2007年 | 550篇 |
2006年 | 451篇 |
2005年 | 398篇 |
2004年 | 334篇 |
2003年 | 256篇 |
2002年 | 195篇 |
2001年 | 158篇 |
2000年 | 125篇 |
1999年 | 94篇 |
1998年 | 106篇 |
1997年 | 100篇 |
1996年 | 78篇 |
1995年 | 67篇 |
1994年 | 48篇 |
1993年 | 39篇 |
1992年 | 54篇 |
1991年 | 37篇 |
1990年 | 42篇 |
1989年 | 40篇 |
1988年 | 38篇 |
1987年 | 26篇 |
1986年 | 24篇 |
1985年 | 27篇 |
1984年 | 19篇 |
1983年 | 10篇 |
1982年 | 14篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
Stefano Milani Hermann Herbst Detlef Schuppan Gerald Niedobitek Ki Young Kim Harald Stein 《Virchows Archiv : an international journal of pathology》1989,415(3):237-242
Summary The intermediate filament profile and the growth fraction of hepatocytes and bile duct epithelial cells were studied in a rat model of biliary fibrosis secondary to common bile duct ligation and scission. Strong vimentin expression was observed in epithelial cells of newly formed bile ductules, while normal liver contained only few weakly positive bile duct epithelial cells. All epithelial cells reacted with a pan-cytokeratin antibody. A monoclonal antibody specific for human cytokeratin 7 selectively reacted with both normal and newly formed bile duct epithelial cells. The intermediate filament profile of hepatocytes was constant, showing no changes during proliferation or in periportal areas adjacent to excessive bile duct formations. The proliferation-associated antigen detected by the antibody Ki-67 was present in many hepatocytes, homogeneously distributed in the lobules, but was seen only in a small proportion of the epithelial cells of the newly formed bile ducts. We conclude that vimentin may serve as an indicator for cellular reorganization in the bile duct system, and that the epithelial cells of newly formed bile ductules in this particular model of secondary biliary fibrosis were most likely to be derived from an outgrowth of the biliary duct system and recruitment of preductular epithelial cells. No morphological or immunohistological evidence suggesting a derivation from hepatocytes by ductular metaplasia or from oval cells was obtained. 相似文献
122.
We report three cases of well-differentiated neuroendocrine carcinoma originating primarily in the anterior mediastinum which had been initially investigated by fine-needle aspiration cytology in conjunction with immunocytochemistry and subsequently recognized as thymic in origin. Aspirates consisted of loosely cohesive or aggregated medium sized elements with round to oval nuclei and scanty cytoplasm. in all cases the Romanowsky stain provided an excellent delineation of definite paranuclear inclusion-like structures having a semicircular or discoid appearance which appeared to contain cytokeratin by immunocytochemical studies and were very similar to the intermediate filament paranuclear “buttons” found in neuroendocrine Merkel cell carcinoma of the skin. This appears to be a novel cytologic observation for thymic neuroendocrine carcinoma. We discuss the significance of the above cytologic and immunocytochemical findings and their possible role in the diagnosis of thymic neuroendocrine carcinoma by fine-needle aspiration biopsy. © 1995 Wiley- Liss, Inc. 相似文献
123.
Chiao-Hsi Chiang Ronald D. Schoenwald 《Journal of pharmacokinetics and pharmacodynamics》1986,14(2):175-211
A single topical instillation of clonidine-3H HCl solution (0.2%) was administered to the rabbit eye (30 μl) in order to study the drug's ocular pharmacokinetics. Seven different tissues and plasma were excised and assayed for drug over 180min. By 45–60 min pseudoequilibrium is reached for the cornea, iris/ciliary body, and aqueous humor. Thereafter, drug levels in these tissues decline in parallel. The data are fit separately to a physiological model and a classical diffusion model for which seven ocular tissue compartments and a plasma reservoir are constructed for each model. Clearance terms and distribution equilibrium coefficients are determined from the tissue level data and used as parameters in fitting the mass balance differential equations representing the physiological model. The model parameters can also be fit to a 0.4% single dose. In a separate experiment, a topical infusion technique was designed to provide a constant rate input to the cornea until an apparent steady state was reached in aqueous humor at 55 min. Aqueous humor levels were assayed for clonidine over the infusion and postinfusion periods. The physiological model parameters are fit to the topical infusion data and show good agreement between the predicted and experimental data. The classical model is too complex to fit the data to integrated exponential equations primarily because the method of residuals is inadequate in determining a sufficient set of initial estimates. This is overcome by dividing the eight-compartment model into seven fragmental models, each representing one to five compartments. A stepwise procedure is developed in which initial estimates are obtained for each separate fragmental model and refined. The refined parameter values can then be used as initial estimates for the complex model. Differential equations for the complex model are fit simultaneously to tissue levels representing each compartment. By observation, the classical model fit the data more closely than the physiological model. Statistical moment theory is also applied to the topical infusion data to determine ocular pharmacokinetic parameters for clonidine. The calculated values are: corneal absorption rate constantk a , 0.00139 min?1; aqueous humor elimination rate constantk 10 , 0.0658min?1; mean residence timeMRT d , 35.6 min; apparent steadystate volume of distributionV ss, 0.530 ml; and ocular clearanceQ e , 14.9 =μl/min. The fraction absorbed from the single instillation is estimated as 0.0163. 相似文献
124.
125.
Francisco A. O. Júnior Clara R. Ruiz Yohanna de Oliveira Marco A. V. Barros Alexandre S. Silva Maria S. B. Santos Vinícius J. B. Martins Camille M. Balarini Valdir A. Braga 《Nutrients》2021,13(3)
Exploring an alternative to improve the clinical management of hypertension, we tested the hypothesis that food supplementation with coconut oil (EVCO), alone or combined with aerobic exercise training, could exert an antihypertensive effect (primary outcome) in patients with stage 1 hypertension. Forty-five hypertensive volunteers of both genders participated in a placebo-controlled clinical trial. The volunteers were submitted to 24-hour ambulatory blood pressure monitoring, analysis of blood pressure variability (BPV), measurement of serum malondialdehyde (MDA) and nutritional assessment. Results indicate that EVCO consumption had no adverse effects. The supplementation did not increase the caloric intake compared with placebo, and the dietary constituents were similar between groups, except for the saturated fats, especially lauric acid. The analysis of blood pressure indicated absence of antihypertensive effect of EVCO alone or combined with physical training. Furthermore, no effects on blood pressure variability and oxidative stress were observed in the supplemented hypertensive patients. Thus, despite the results observed in pre-clinical studies, the current clinical study did not provide evidence to support the use of coconut oil as an adjuvant in the management of hypertension in humans. 相似文献
126.
医院是为人类提供公共卫生服务的一个单位,其存在具有至关重要的影响意义,是人们医疗卫生事业的主要承担场所,医院所提供的公共卫生服务水平主要受到两个方面因素的影响,其一是医疗卫生发展水平,其二是人们生活水平;而这两种因素均受到人类社会经济发展水平的影响,由此可见,医院可以直接反映人类社会的发展水平,医院管理治疗会对其实际运行水平产生直接性影响,同时也侧面体现了我国公共卫生服务质量。因此,基于此种社会现实下,结合新形势要求,分析医院档案管理工作存在的弊端,并探讨创新途径具有至关重要的影响意义,这不仅是国家发展、社会发展的要求,同时也是医院实现可持续运行的根本条件,是当前医院刻不容缓需要解决的主要问题。 相似文献
127.
产后疼痛是困扰产妇的常见问题,如治疗不当可能会导致阿片类药物滥用、产后抑郁和疼痛长期存在等不良后果。因此,美国妇产科医师学会(American College of Obstetricians and Gynecologists,ACOG)于2021年9月提出了针对产后疼痛的临床共识,专门对产后疼痛的一般管理、阴道分娩、剖宫产术后、母乳喂养时及出院后疼痛的处置给出了治疗建议与指导,强调了阶梯式多模式药物镇痛方法与个体化用药原则。推荐临床用药可遵循“非阿片类镇痛药(如对乙酰氨基酚和非甾体抗炎药)—弱阿片类药物—强阿片类药物(必要时)”阶梯式给药原则,并可合理联合用药。对此进行简要介绍与要点解读。 相似文献
128.
目的 :探讨急性有机磷中毒 (AOPP)死亡。方法 :回顾分析 1998年至 2 0 0 0年 8月死亡病例 4 6例 ,占同期中AOPP5 0 8例的 9.0 6 %。结果 :洗胃不彻底 15例 (32 .6 % ) ,阿托品用量不足 12例(2 6 .1% ) ;中间综合征 (IMS) 7例 (15 .2 % )阿托品中毒 5例 (10 .9% ) ;混合性中毒 3例 (6 .5 % ) ,其余存在严重并发症。结论 :表明洗胃不彻底 ,阿托品用量不足及中毒、IMS、混合性中毒是AOPP死亡的主要原因。对AOPP并发的紧急凶险症状未及时控制也是其死亡原因之一。 相似文献
129.
李学勤 《南通大学学报(哲学社会科学版)》2001,17(4):85-89
国家“九五”期间重点科技攻关计划项目“夏商周断代工程” ,经过200位专家学者前后5年的集体努力 ,已于2000年9月通过验收 ,同年11月公布了《夏商周断代工程1996-2000年阶段成果报告 (简本 )》。这一项目采取自然科学与人文社会科学多学科结合的研究途径 ,制定了《夏商周年表》 ,为我国古代夏商周这一重要历史时期的年代学提供了科学依据 ,使进一步探索中国古代文明起源及其早期发展有了可靠的基础。 相似文献
130.
目的研究以带蒂复合组织瓣修复胸骨旁小切口术后胸壁缺损的可行性。方法观察尸体前胸壁深层结构的血供 规律,测量胸骨外侧缘与胸廊内动脉之间的距离,并在此基础之上设计出以胸阔内动脉为蒂的肋软骨助间肌瓣。结果 前胸壁深层各结构均由胸廓内动脉及其分支供血,胸廊内动脉里胸骨外侧缘的距离为1cm左右。紧挨胸骨外侧缘切开 肋软骨,可以避免胸廓内动脉的损伤。以该动脉为帮,可以保证数种肋软骨肋间肌瓣有良好的血供。结论用以胸廊内动 脉为蒂的肋软骨助间肌瓣修复心脏外科术后的胸壁缺损具有良好的可行性。 相似文献