全文获取类型
收费全文 | 34449篇 |
免费 | 3204篇 |
国内免费 | 2542篇 |
专业分类
耳鼻咽喉 | 398篇 |
儿科学 | 392篇 |
妇产科学 | 369篇 |
基础医学 | 4076篇 |
口腔科学 | 583篇 |
临床医学 | 4661篇 |
内科学 | 4773篇 |
皮肤病学 | 411篇 |
神经病学 | 1984篇 |
特种医学 | 1274篇 |
外国民族医学 | 24篇 |
外科学 | 3252篇 |
综合类 | 6663篇 |
现状与发展 | 11篇 |
预防医学 | 2136篇 |
眼科学 | 1110篇 |
药学 | 3503篇 |
25篇 | |
中国医学 | 1922篇 |
肿瘤学 | 2628篇 |
出版年
2024年 | 78篇 |
2023年 | 605篇 |
2022年 | 908篇 |
2021年 | 1739篇 |
2020年 | 1413篇 |
2019年 | 1209篇 |
2018年 | 1250篇 |
2017年 | 1198篇 |
2016年 | 1031篇 |
2015年 | 1592篇 |
2014年 | 1963篇 |
2013年 | 1729篇 |
2012年 | 2713篇 |
2011年 | 2829篇 |
2010年 | 1738篇 |
2009年 | 1390篇 |
2008年 | 1668篇 |
2007年 | 1762篇 |
2006年 | 1757篇 |
2005年 | 1785篇 |
2004年 | 1114篇 |
2003年 | 1052篇 |
2002年 | 902篇 |
2001年 | 797篇 |
2000年 | 821篇 |
1999年 | 934篇 |
1998年 | 595篇 |
1997年 | 660篇 |
1996年 | 496篇 |
1995年 | 416篇 |
1994年 | 355篇 |
1993年 | 206篇 |
1992年 | 271篇 |
1991年 | 238篇 |
1990年 | 201篇 |
1989年 | 179篇 |
1988年 | 168篇 |
1987年 | 129篇 |
1986年 | 100篇 |
1985年 | 77篇 |
1984年 | 34篇 |
1983年 | 20篇 |
1982年 | 28篇 |
1981年 | 15篇 |
1980年 | 8篇 |
1979年 | 9篇 |
1965年 | 2篇 |
1940年 | 3篇 |
1935年 | 2篇 |
1934年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
991.
Expression and Prognostic Roles of Eag1 in Resected Esophageal Squamous Cell Carcinomas 总被引:1,自引:0,他引:1
Ding XW Wang XG Luo HS Tan SY Gao S Luo B Jiang H 《Digestive diseases and sciences》2008,53(8):2039-2044
Expression of Eag1 was detected in resected esophageal squamous cell carcinomas tissues and matched tissues by immunohistochemistry and RT-PCR. Positive expression of Eag1 protein was 75% (51/68), and mRNA was 73% (8/11) in primary cancer tissues. Eag1 protein positively stained in all 10 metastatic lymph nodes. Eag1 protein and mRNA were negatively expressed in all non-cancerous matched tissues. Eag1 protein was associated with depth of penetration (P = 0.023), but not associated with other clinicopathological factors. Eag1 protein positive group had a significantly shorter survival time than the negative group (P = 0.005). Survival rates at each time-point for the positive group were lower than that for the negative group (P = 0.006), and Eag1 was identified as an independent prognostic factor of long-term survival (P = 0.016). In conclusion, Eag1 was aberrantly expressed in ESCC and correlated with poor prognosis after surgery. 相似文献
992.
Tong-Hua Liu De-Tian Wang Jin-Ling Cao Yu-Feng Luo Zhi-Yong Liang Department of Pathology Peking Union Medical College Hospital Chinese Academy of Medical Sciences Beijing China Shuan-Zeng Wei Department of Pathology North China Coal Medical College Tangshan Hebei Province China 《World journal of gastroenterology : WJG》2005,(24)
AIM: To investigate the clinicopathologic characteristics, immunophenotype and TCR gene rearrangements of hepatosplenic T-cell lymphoma in eight Chinese patients. METHODS: Eight Chinese patients with hepatosplenic 76 T-cell lymphomas were studied. Hematoxylin-eosin-stained slides and clinical histories were reviewed. We also carried out immunohistochemical staining for CD3, CD4, CD8, CD20, CD43, CD56, CD79a, UCHL-1, and TCR γδ. Rearrangements of TCR gamma and delta chain genes were also studied. RESULTS: The spleens were enlarged and the cut surfaces were homogeneous and red-purple in color without identifiable gross lesions or enlarged hilar lymph nodes. Histologically, lymphoma cells infiltrated the cords of Billroth and often packed the sinuses. Liver biopsy showed lymphoma cell infiltrations in the sinusoids, and three cases showed involvements of the portal tracts. Immunohistochemically lymphoma cells were positive for CD3, CD43, and CD56 in all cases. Four of eight cases were positive for CD8, and all cases were negative for CD4 (6/6). Monoclonal rearrangements of TCR y gene were demonstrated by PCR analysis in five out of the eight cases. TCR δ gene rearrangements were detected in six out of the eight cases, which demonstrated single bands on PAGE gel, and the amplification products in two cases were confirmed by sequencing. CONCLUSION: The clinicopathology of hepatosplenic γδ T-cell lymphoma in Chinese patients is similar to what was previously reported except that the splenomegaly is not so massive, and CD8 is positive. 相似文献
993.
用克山病病区粮或加硒和加镉的病区粮喂养S.D大鼠,1~2个月后取其组织进行分析。结果显示:用病区粮饲养大鼠,可使大鼠免疫器官的发育发生障碍,低硒和高镉对大鼠组织的损伤呈现相加作用,加硒可拮抗镉的部分毒性,组织中脂质过氧化物水平与循环免疫复合物的含量呈显著正相关,与还原型谷胱甘肽含量呈显著负相关。说明克山病的致病因素是复杂的,低硒是主要的致病因素,高镉则加重其危害程度,并可能涉及自身免疫病理过程。 相似文献
994.
995.
Yao-Fan Fang Yeong-Jian Jan Wu Chang-Fu Kuo Shue-Fen Luo Kuang-Hui Yu 《Clinical rheumatology》2016,35(8):1977-1984
This study aims to investigate the prevalence and predictive risk factors of malignancy in patients with polymyositis (PM) and dermatomyositis (DM). The medical records of 192 PM/DM patients followed up in a medical center between January 2000 and December 2013 were reviewed. Among the 192 patients, 33 patients (17.2 %) had associated cancer. Both PM and DM are significantly associated with cancer, although the risk of cancer appears to be somewhat higher among patients with DM (23.0 %) than among those with PM (8.9 %). Nasopharyngeal cancer (30.3 %) and breast cancer (18.2 %) comprised the most common malignant diseases associated with PM/DM. Univariate analysis showed that an older age at PM/DM onset, heliotrope rash, Gottron’s sign, dysphagia, and low creatine phosphokinase (CPK) level were associated with increased malignancy. Multivariate analysis revealed that independent predictors of malignancy in PM/DM were age >40 years at PM/DM onset (adjusted OR 3.44; 95 % CI 1.08–10.98; p?=?0.037) and heliotrope rash (adjusted OR 2.96; 95 % CI 1.04–8.43; p?=?0.042). During the follow-up period, 66 (34.4 %) patients died and the overall patient survival rates were 83.1 % at 1 year, 78.9 % at 2 years, 74.2 % at 5 years, and 65.5 % at 10 years. This study demonstrates a high frequency of malignancy (17.2 %) in DM/PM patients. Nasopharyngeal cancer and breast cancer were the most common cancer types in DM/PM patients in our study. Cancer screening should be offered to patients with newly diagnosed DM/PM. Moreover, all patients should be evaluated for the possibility of an underlying malignancy during treatment. 相似文献
996.
Ding L Xu J Luo X Chegini N 《The Journal of clinical endocrinology and metabolism》2004,89(11):5549-5557
997.
998.
基质金属蛋白酶-9(MMP-9)是MMP家庭中的一员,可特异性降解细胞外基质。脑缺血早期(1~3d),MMP-9可通过降解基底膜及内皮细胞紧密连接破坏血脑屏障,导致继发性脑水肿和脑出血。脑缺血后期(7~14d),MMP-9则能促进神经血管再生,有利于损伤脑组织的恢复。 相似文献
999.
Noninvasive transcutaneous low frequency ultrasound enhances thrombolysis in peripheral and coronary arteries 总被引:7,自引:0,他引:7
Siegel RJ Atar S Fishbein MC Brasch AV Peterson TM Nagai T Pal D Nishioka T Chae JS Birnbaum Y Zanelli C Luo H 《Echocardiography (Mount Kisco, N.Y.)》2001,18(3):247-257
Previous studies have shown that external ultrasound with low frequencies and high intensities can enhance thrombolytic drug-induced clot dissolution during in vitro experiments. In this series of studies, we evaluated the efficacy of peripheral and coronary thrombolysis in vivo in animals by using noninvasive transcutaneous ultrasound combined with thrombolytic drugs (streptokinase and tPA) and/or microbubbles agents (dodecafluoropentane [DDFP] and perfluorocarbon-exposed sonicated dextrose albumin [PESDA]). Thrombotic occlusions were induced in 74 rabbit iliofemoral arteries and 24 canine left anterior descending (LAD) coronary arteries in this in vivo study. By using the combination of transcutaneous ultrasound and streptokinase, the angiographic patency rate in rabbit iliofemoral arteries was higher (56%-100%) than with ultrasound (6%; P < or = 0.0036) and streptokinase alone (6%; P < or = 0.0012). Also, with transcutaneous ultrasound and microbubbles, the angiographic patency rates were 76%-100% as compared with ultrasound alone (0%, P < or = 0.0003) or microbubbles alone (9%, P < or = 0.0001). In the canine study of acute myocardial infarction, thrombolysis in myocardial infarction (TIMI) grade flow at 90 minutes in the tPA alone group was 0.92 +/- 1.4 as compared with 2.42 +/- 1.9 in the tPA plus transthoracic ultrasound group (P = 0.006). There was much improved reperfusion with tPA plus ultrasound as compared with tPA alone. In vivo animal studies demonstrate that noninvasive transcutaneous ultrasound can greatly enhance the effect of clot dissolution with thrombolytic drugs and/or microbubbles, and has the potential for clinical application as an adjunctive method to improve arterial thrombolysis. 相似文献
1000.