全文获取类型
收费全文 | 71473篇 |
免费 | 8185篇 |
国内免费 | 2601篇 |
专业分类
耳鼻咽喉 | 445篇 |
儿科学 | 1238篇 |
妇产科学 | 568篇 |
基础医学 | 6327篇 |
口腔科学 | 473篇 |
临床医学 | 6159篇 |
内科学 | 9280篇 |
皮肤病学 | 362篇 |
神经病学 | 407篇 |
特种医学 | 3122篇 |
外国民族医学 | 124篇 |
外科学 | 7739篇 |
综合类 | 13079篇 |
现状与发展 | 18篇 |
预防医学 | 2347篇 |
眼科学 | 194篇 |
药学 | 5322篇 |
42篇 | |
中国医学 | 2785篇 |
肿瘤学 | 22228篇 |
出版年
2024年 | 251篇 |
2023年 | 1319篇 |
2022年 | 2636篇 |
2021年 | 3598篇 |
2020年 | 3147篇 |
2019年 | 2616篇 |
2018年 | 2440篇 |
2017年 | 2955篇 |
2016年 | 3274篇 |
2015年 | 3658篇 |
2014年 | 4928篇 |
2013年 | 4687篇 |
2012年 | 4428篇 |
2011年 | 4697篇 |
2010年 | 3821篇 |
2009年 | 3533篇 |
2008年 | 3568篇 |
2007年 | 3789篇 |
2006年 | 3393篇 |
2005年 | 3070篇 |
2004年 | 2465篇 |
2003年 | 2077篇 |
2002年 | 1722篇 |
2001年 | 1508篇 |
2000年 | 1285篇 |
1999年 | 1016篇 |
1998年 | 933篇 |
1997年 | 834篇 |
1996年 | 677篇 |
1995年 | 523篇 |
1994年 | 498篇 |
1993年 | 374篇 |
1992年 | 388篇 |
1991年 | 310篇 |
1990年 | 275篇 |
1989年 | 228篇 |
1988年 | 223篇 |
1987年 | 191篇 |
1986年 | 157篇 |
1985年 | 136篇 |
1984年 | 119篇 |
1983年 | 90篇 |
1982年 | 86篇 |
1981年 | 79篇 |
1980年 | 80篇 |
1979年 | 57篇 |
1978年 | 34篇 |
1977年 | 28篇 |
1976年 | 14篇 |
1975年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Measurements of respiratory mechanics are frequently made in ventilated infants and children. Esophageal pressure measurements (Pes using a balloon on a catheter have been used to partition the respiratory mechanics into lung and chest wall components. Appropriate positioning of this balloon is crucial to obtain accurate estimates of pleural pressure. Traditionally, in spontaneously breathing subjects the balloon position is assessed with an occlusion test. In ventilated subjects, it is not always possible to perform an occlusion test prior to paralysis, and even if such a test is performed it may not be relevant under conditions of positive pressure ventilation. We have assessed a positive pressure occlusion test that is suitable for paralyzed subjects. By occluding the airway opening and applying gentle pressure to the abdomen or rib cage, positive swings in pressure can be measured by both Pes and airway opening pressure (Pao). We compared traditional occlusion tests measured in 16 spontaneously breathing puppies to the positive pressure occlusion test performed after paralysis. In 2 pups we were unable to obtain a reasonable traditional occlusion test (>15% difference between Pes and Pao) but we obtained 10 traditional occlusion tests in each of the remaining 14 pups (2.1–14 kg). In 11 of these animals Ape, was within 10% of Pao. This compared well to positive pressure occlusion test using abdominal pressure performed after paralysis, where Apes was within 10% of ΔPao in 10 animals. In 9 of these pups occlusion tests were also performed by applying pressure on the rib cage, where ΔPes was within 10% of ΔPao in 6 animals. These results suggest that it is possible to perform accurate occlusion tests in paralyzed subjects by abdominal or rib cage compression with the airway occluded. Pediatr Pulmonol. 1994; 17:56–62. © 1994 Wiley-Liss, Inc. 相似文献
52.
A 26 year old female presented with partial expression of Carney's triad. This is the first Australian report of the condition. The role of surgery and the need for vigilance to detect the occurrence of the complete triad are stressed. 相似文献
53.
Exposure of H69 small cell lung carcinoma cells to nicotinic agonists resulted in a significant increase (up to 100%) in cell number after 6 to 12 days. The effect of nicotine (10−8 M to 10−4 M) was both dose and time dependent as was that of another nicotinic agonist cytisine (10−6 M to 10−4 M). Interstingly, both the nicotine and cytisine induced increases in H69 cell number were blocked by α-bungarotoxin, as well as d-tubocurarine a nicotinic blocker which appears to interact with most nicotinic receptors. These results suggest that the nicotine induced increase in cell number is mediated through an interaction at the nicotinic α-bungarotoxin receptor. This idea is further supported by experiments which show (1) that H69 cells possess high affinity α-bungarotoxin sites (Kd = 25 nM, Bmax = 10.4 fmol/106 cells) with the characteristics of a nicotinic α-bungarotoxin receptor and (2) that the potencies of nicotinic receptor ligands in the α-bungarotoxin binding assay were similar to those observed in the functional studies. Northern analysis showed that mRNA for α7, a putative nicotinic α-bungarotoxin binding subunit, and for α5 were present in H69 cells. The present data provide further evidence that nicotine increases cell number in small cell lung carcinoma and are the first to show that this effect is mediated through an interaction at the nicotinic α-bungarotoxin receptor population. These results suggest that the α-bungarotoxin site may be involved in modulating proliferative responses in neuroendocrine derived SCLC cells. 相似文献
54.
Extrapulmonary small-cell cancer is a distinct clinicopathological entity from smallcell anaplastic carcinoma of the lung. Approximately 1,000 cases have been projected annually in the United States, which represents an overall incidence of between 0.1% and 0.4% of all cancer. Not surprisingly then, little information is available regarding the treatment of this disease, which presents a challenge to the clinician when it is regionally confined. The majority of patients with extrapulmonary small-cell neoplasms have only been treated with local modalities of therapy, surgery, radiation, or a combination of both. Prolonged survival is not infrequent, which is in contrast to the experience for small-cell lung cancer and surprising given our current systemic approach to patients with this disease. This report will summarize the similarities and differences in biology, natural history, and clinical characteristics of patients with extrapulmonary small-cell cancer and smallcell anaplastic carcinoma of the lung. The histogenesis of small-cell cancer is briefly reviewed. A general therapeutic approach to patients with small-cell lung cancer is reported. Lastly, recommendations for therapy of patients with regionally confined extrapulmonary small-cell cancer by primary site are outlined. 相似文献
55.
56.
支气管动脉灌注化疗联合直线加速器放射治疗Ⅲa期非小细胞肺癌 总被引:1,自引:1,他引:0
目的 研究支气管动脉灌注化疗联合直线加速器放射治疗Ⅲa期非小细胞肺癌 (NSCLC)的可行性及临床价值。方法 76例NSCLC患者随机分成A、B 2组 ,A组先行 2次支气管动脉灌注化疗 (BAI) ,第 2次BAI 1~ 2周后再行直线加速器放射治疗 (RT) ;B组单纯行 2次BAI (对照组 )。结果 临床疗效 ,A组 (BAI RT)和B组 (BAI)分别为 89.47%和 60 .5 3% (Ρ <0 .0 1) ;1、3年生存率 ,A、B组分别为 81.5 8%、5 0 .0 0 %和 60 .5 3%、2 1.0 5 % ( 0 .0 1<Ρ <0 .0 5 )。结论 支气管动脉灌注化疗联合直线加速器放射治疗Ⅲa期非小细胞肺癌的临床疗效和患者 1、3年生存率均显著提高 相似文献
57.
58.
严重肺挫伤早期肺泡灌洗液表面活性蛋白变化与肺功能及形态学改变的关系 总被引:1,自引:1,他引:0
目的探讨严重肺挫伤及缺血再灌注后早期肺泡灌洗液(BALF)中表面活性蛋白(SP)-A、B、C、D动态变化与肺功能及肺形态学改变的关系。方法75只兔随机分为对照组(A)、肺挫伤组(B)及缺血再灌注组(C)。每组均为25只。检测各组0,1,2,3,4h肺功能变化及BAIF中SP—A、B、C、D含量百分比,进行组织病理学及电镜检查。结果与A组比较,B、C组sSP—A、B、C、D含量百分比明显减少(P〈0.01);肺功能出现明显的损害且呈持续下降(P〈0.05);肺泡Ⅱ型细胞电镜及病理学检查呈不同程度的炎症及变性改变。结论严重肺挫伤BALF中SP—A、B、C、D动态变化与肺功能及肺组织病理学改变一致。 相似文献
59.
60.
S. van Ruth† EBL van Dorst‡ MR Canninga-van Dijk§ MS de Bruin-Weller† 《Journal of the European Academy of Dermatology and Venereology》2007,21(5):678-680
Cutaneous metastasis of vaginal carcinoma is extremely rare. So far, the total number of reported skin metastasis of vaginal carcinoma is only one. We present another case with an unusual manifestation of vagina carcinoma metastasis: skin metastasis presenting as a leg ulcer on the lower leg. 相似文献