全文获取类型
收费全文 | 31755篇 |
免费 | 2757篇 |
国内免费 | 1452篇 |
专业分类
耳鼻咽喉 | 102篇 |
儿科学 | 334篇 |
妇产科学 | 146篇 |
基础医学 | 2524篇 |
口腔科学 | 600篇 |
临床医学 | 2780篇 |
内科学 | 5908篇 |
皮肤病学 | 212篇 |
神经病学 | 1787篇 |
特种医学 | 1171篇 |
外国民族医学 | 45篇 |
外科学 | 4016篇 |
综合类 | 6029篇 |
现状与发展 | 2篇 |
预防医学 | 972篇 |
眼科学 | 147篇 |
药学 | 2228篇 |
30篇 | |
中国医学 | 1427篇 |
肿瘤学 | 5504篇 |
出版年
2024年 | 72篇 |
2023年 | 510篇 |
2022年 | 896篇 |
2021年 | 1324篇 |
2020年 | 1168篇 |
2019年 | 986篇 |
2018年 | 891篇 |
2017年 | 1080篇 |
2016年 | 1216篇 |
2015年 | 1215篇 |
2014年 | 1916篇 |
2013年 | 2060篇 |
2012年 | 1741篇 |
2011年 | 1835篇 |
2010年 | 1456篇 |
2009年 | 1434篇 |
2008年 | 1534篇 |
2007年 | 1768篇 |
2006年 | 1432篇 |
2005年 | 1341篇 |
2004年 | 1083篇 |
2003年 | 910篇 |
2002年 | 876篇 |
2001年 | 865篇 |
2000年 | 763篇 |
1999年 | 612篇 |
1998年 | 552篇 |
1997年 | 502篇 |
1996年 | 475篇 |
1995年 | 468篇 |
1994年 | 436篇 |
1993年 | 330篇 |
1992年 | 292篇 |
1991年 | 269篇 |
1990年 | 237篇 |
1989年 | 201篇 |
1988年 | 196篇 |
1987年 | 147篇 |
1986年 | 117篇 |
1985年 | 149篇 |
1984年 | 119篇 |
1983年 | 73篇 |
1982年 | 79篇 |
1981年 | 73篇 |
1980年 | 66篇 |
1979年 | 41篇 |
1978年 | 30篇 |
1977年 | 29篇 |
1976年 | 28篇 |
1975年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The aim of this pilot study was to examine the role of the striatum and cerebellum in the adaptation to a novel movement within a sequence of practiced movements using a motor learning paradigm. The performance of patients in the early or advanced stages of Parkinson's disease (PD) and of patients with damage to the cerebellum (CE) was compared, respectively to a group of aged and young matched controls on an adapted version of the Mirror-Tracing Test. In this task, subjects were required to trace a series of complex figures in two conditions: (1) a Practiced condition, in which the figures were composed of the juxtaposition of three simple designs that were extensively practiced before; and (2) a Mixed condition in which triads were created by replacing the last simple figure of the triads in the Practiced condition by a new simple figure that had never been traced individually before. Results showed that all clinical groups were slower than controls at tracing the Practiced triads. Most interestingly, however, only patients in the advanced stages of PD showed increased completion time to trace the triads in the Mixed condition. This suggests that a bilateral striatal dysfunction affects the ability to adapt to a novel motion within a sequence of practiced movements. Although exploratory, these results support a functional dissociation between the striatum and cerebellum in acquiring visuomotor skilled behaviors. 相似文献
42.
目的 :探讨大鼠胃粘膜与急性胃粘膜损伤之间的关系。方法 :采用原子吸收光谱分析法 ,测定胃粘膜Ca2 +含量。结果 :胃粘膜损伤程度随应激时间延长而加重 ,胃粘膜Ca2 + 含量却下降 ,二者呈明显负相关 ,但是 ,CaCl2 预应激或应用钙通道阻断剂 ,可减轻胃粘膜损伤程度。结论 :Ca2 + 在急性胃粘膜损伤中有一定的作用。 相似文献
43.
人端粒酶RNA的cDNA探针制备及其对胃粘膜细胞端粒酶RNA表达的检测 总被引:3,自引:0,他引:3
目的 建立人端粒酶RNA表达的检测方法。方法 制备人端粒酶RNA,(human telomeraseRNA,hTR)的cDNA探针,分别应用RNA斑点杂交与端粒重复序列扩增法(TRAP)分析检测不同胃粘膜的端粒酶RNA的表达与端粒酶活性。结果 人端粒酶RNA的cDNA探针制备成功。18例活检胃癌组织及45例手术胃癌组织RNA斑点杂交检测的阳性率均为l00%,相应TRAP分析的阳性率分别为88.89%、86.67%,低于RNA斑点杂交(P<0.05)。同时RNA斑点杂交结果提示在非癌胃组织中随着肠化程度增高人端粒酶RNA表达也增强。结论 RNA斑点杂交检测人端粒酶RNA,具有高度的敏感性和特异性,弥补了TRAP分析敏感性不足的缺点。 相似文献
44.
Background: The bariatric patient exists in dynamic relationship with family members and friends who have considerable influence
upon the patient and his or her surgical outcome. When family members and friends behave as intimate saboteurs, they attempt
to hamper, hurt, or subvert the bariatric patient's goal of achieving and maintaining a healthy body weight. Successful or
not, intimate saboteurs provide significant treatment challenges for the patient and the treatment team. Methods and Patients:
Patient profiles provide examples of intimate sabotage. The psychological construct of Family Systems Theory is used as a
plausible explanation for the sabotage of friends and family. Conclusions: Multidisciplinary professionals treating the bariatric
patient must be aware of the critical influence of intimate saboteurs and the tactics they use to sabotage. Treatment guidelines
recommended by Family Systems Theory are presented as strategies to mitigate the influence of intimate saboteurs. 相似文献
45.
A Decade of Change in Obesity Surgery 总被引:4,自引:0,他引:4
Edward E Mason MD PhD Shenghui Tang MS Kathleen E Renquist BS Dwight T Barnes Joseph J Cullen MD Cornelius Doherty MD James W Maher MD 《Obesity surgery》1997,7(3):189-197
Background: The International (formerly National) Bariatric Surgery Registry began collecting data in January 1986. The aim
of this study was to examine changes in the practice of surgical treatment of severe obesity that occurred during the decade
of 1986 through 1995, as observed in the IBSR data. Methods: All data submitted to the IBSR during the decade were transferred
to the IBM mainframe computer for analysis. Characteristics of operative type populations were compared over time using analysis
of variance (ANOVA) for age, body mass index (BMI), operative weight and Chi-square (χ2) test for gender. Results: There has been a steady increase over the decade in mean patient weight. The operations used have
changed from predominantly ‘simple’ operations to more frequent use of ‘complex’ operations. Within the categories of ‘simple’
and ‘complex’, an increase in the variety of operations occurred. As a group, patients with ‘simple’ operations have been
heavier, more often male and public pay patients than those who have undergone ‘complex’ operations. One year weight loss
was greater for Roux-en-Y gastric bypass (RGB) than vertical banded gastroplasty (VBG), but follow-up rates were too low to
study the relative merits of the operations used. The reported incidence of operative mortality and serious complications
(leak with peritonitis, abscess and pulmonary embolism) remained low. Conclusions: These observations and their implications
can be summarized in three statements which relate to action for improved patient care in the beginning of the new century:
(1) increasing weight of candidates for surgical treatment during this decade indicates the need for earlier use of operative
treatment before irreversible complications of obesity can develop; (2) low risk of obesity surgery, decreasing postoperative
hospital stay, and early weight control support the continued and increased use of surgical treatment; (3) continued widespread
use of both ‘simple’ and ‘complex’ operations with increased modifications of standard RGB and VBG procedures emphasizes the
need for standardized long-term data and analyses regarding both weight control and postoperative side-effects. 相似文献
46.
47.
48.
河南食管癌高、低发区无症状人群食管固有膜血管乳头的变化 总被引:2,自引:1,他引:1
目的:探讨食管癌高、低发区无症状居民食管上皮固有膜血管乳头(简称乳头)增生特征(乳头密度和高度)及其与病变分布的关系,加深对食管癌变早期形态学变化特征的了解。方法:2480例无症状人群食管粘膜活检组织,采用食管癌高低发区食管纤维内镜检查,粘膜活检,组织病理学检查和形态学测量技术对食管乳头的分布特征及其与病变的关系进行分析。结果:食管癌高低发区居民食管中、下段乳头升高(≥上皮厚度的1/2)发生率之间差异并不明显(P>0.05),但是,高发区居民食管中段乳头密度(乳头数目/mm)明显高于下段,并高于低发区居民食管中段的乳头密度(P<0.05);高发区居民食管上皮乳头升高伴基底细胞过度增生患者明显高于正常人(P<0.05),而低发区未观察到类似情况。结论:乳头增生表现为乳头数目增多和乳头升高是食管癌高发区人群食管上皮特征性形态学变化,高分区居民上皮乳头升高伴明显基底细胞过度增生,提示乳头增生可能是食管癌变极早期阶段的重要形态学变化,反映了上皮细胞的增生状态。 相似文献
49.
姜泊 《南方医科大学学报》2002,22(5):385-387
应用常规内镜技术难以发现大肠平坦型病变和凹陷型病变。近年来染色内镜和放大内镜技术已经发展成熟,在国外已获广泛应用,可以发现大肠微小病变和早期大肠癌。应用腺管开口分型方法可以预测肿瘤病变的组织学类型及肿瘤的浸润深度,据此可确定行内镜下粘膜剥离术或分片粘膜剥离术将肿瘤切除,抑或行外科手术治疗。在当前我国的胃肠内镜医疗界,应广泛开展染色内镜和放大内镜的临床应用,以早期发现大肠病变,提高我国大肠癌的内镜诊治水平。 相似文献
50.
胃癌雌激素受体表达及新一代抗受体药物在胃癌治疗中的探讨 总被引:3,自引:0,他引:3
目的 探讨胃癌雌激素受体 (ER)实际表达率 ,为临床使用新一代抗ER药物 (toremifene ,TOR)治疗胃癌提供临床病理依据。方法 用免疫组化法对 349例胃癌标本进行ER的检测 ,其中 2 99例用ABC(avidinbiotinperoxidasecomplex)法 ,5 0例用葡聚糖聚合物技术二步法进行检测。在检测ER的同时也检测 p5 3及PCNA的表达。结果 两种检测方法的ER阳性率分别为 2 .3% (7/ 2 99)及 0 % (0 / 5 0 ) ,p5 3阳性率 37.1% (111/ 2 99)及 4 6 %(2 3/ 5 0 ) ,PCNA 94 .3% (2 82 / 2 99)及 96 % (48/ 5 0 )。结论 胃癌细胞可表达ER但实际表达率很低 ,而且存在质和量的变化。tamoxifen (TAM )及TOR的抗胃癌效应需要进一步研究 相似文献