全文获取类型
收费全文 | 6597篇 |
免费 | 353篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 176篇 |
妇产科学 | 86篇 |
基础医学 | 1232篇 |
口腔科学 | 104篇 |
临床医学 | 351篇 |
内科学 | 1393篇 |
皮肤病学 | 169篇 |
神经病学 | 546篇 |
特种医学 | 200篇 |
外科学 | 1093篇 |
综合类 | 28篇 |
预防医学 | 207篇 |
眼科学 | 223篇 |
药学 | 417篇 |
中国医学 | 15篇 |
肿瘤学 | 716篇 |
出版年
2023年 | 34篇 |
2022年 | 72篇 |
2021年 | 116篇 |
2020年 | 67篇 |
2019年 | 115篇 |
2018年 | 117篇 |
2017年 | 107篇 |
2016年 | 103篇 |
2015年 | 128篇 |
2014年 | 155篇 |
2013年 | 213篇 |
2012年 | 268篇 |
2011年 | 330篇 |
2010年 | 162篇 |
2009年 | 150篇 |
2008年 | 315篇 |
2007年 | 311篇 |
2006年 | 349篇 |
2005年 | 431篇 |
2004年 | 408篇 |
2003年 | 403篇 |
2002年 | 384篇 |
2001年 | 165篇 |
2000年 | 129篇 |
1999年 | 155篇 |
1998年 | 108篇 |
1997年 | 114篇 |
1996年 | 91篇 |
1995年 | 82篇 |
1994年 | 73篇 |
1993年 | 68篇 |
1992年 | 123篇 |
1991年 | 112篇 |
1990年 | 94篇 |
1989年 | 120篇 |
1988年 | 83篇 |
1987年 | 84篇 |
1986年 | 80篇 |
1985年 | 76篇 |
1984年 | 51篇 |
1983年 | 49篇 |
1982年 | 20篇 |
1981年 | 28篇 |
1980年 | 37篇 |
1979年 | 27篇 |
1978年 | 38篇 |
1977年 | 30篇 |
1976年 | 19篇 |
1973年 | 21篇 |
1970年 | 20篇 |
排序方式: 共有6996条查询结果,搜索用时 0 毫秒
1.
2.
Mana Ichimura Koichi Hiratsuka Naomi Ogura Tadahiko Utsunomiya Hiroyuki Sakamaki Toshirou Kondoh Yoshimitsu Abiko Shigeo Otake Masafumi Yamamoto 《Journal of oral pathology & medicine》2006,35(3):167-174
BACKGROUND: To understand the immunopathological features of oral lichen planus (OLP), we analyzed the expression of chemokines in the epithelial cell layers. Methods: Epithelia from OLP or healthy gingiva were collected by laser microdissection. The chemokine and chemokine receptor expressions in the epithelia were analyzed by DNA microarray. RESULTS: High levels of MIP-3alpha/LARC/CCL20 and its receptor CCR6 were expressed in the lesional epithelia. Furthermore, DC-CK1/CCL18, ELC/CCL19, SDF-1/CXCL12 and CXCR4 expressions were also increased. Immunohistologial analysis showed that high numbers of Langerhans cells (LCs) were present in the epithelia of OLP. Lesional epithelia also expressed high levels of the ligands specific for CXCR3 (e.g. MIG/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11) and CCR5 (e.g. RANTES/CCL5). CONCLUSIONS: Infiltration of LCs is orchestrated by CCR6. Further, LCs residing in the lesional epithelia may be a mature phenotype. Moreover, infiltration of T cells in OLP could be mediated by signaling pathways through CXCR3 and CCR5. 相似文献
3.
K. Arima Minako Nakamura Nobuhiko Sunohara Masafumi Ogawa Midori Anno Yoko Izumiyama Shigeo Hirai Kazuhiko Ikeda 《Acta neuropathologica》1997,93(6):558-566
Coiled bodies and interfascicular threads are conspicuous white matter abnormalities of brains of patients with progressive
supranuclear palsy (PSP). Both structures are argyrophilic and immunoreactive for the microtubule-binding protein tau. This
report concerns the ultrastructural localization of interfascicular threads and their relationship to coiled bodies in five
PSP patients. We showed for the first time that abnormal tubules with a 13- to 15-nm diameter and fuzzy outer contours were
the common structures of coiled bodies in the oligodendroglial perikarya and of interfascicular threads. Moreover, the tubules
were immunolabeled by anti-tau antibodies. The abnormal tau-positive tubules of interfascicular threads were located in the
inner loop of the myelin sheath. Our study further indicated that the thread-like structures in the white matter comprised,
at least in part, oligodendroglial processes, and that they were also present in gray matter. We consider that the formation
of coiled bodies in the perikarya and of interfascicular threads represents a common cytoskeletal abnormality of the oligodendroglia
of PSP patients. Moreover, even though the white matter alterations of PSP resemble those of corticobasal degeneration, there
are certain ultrastructural differences in the abnormal oligodendroglial tubules of the two diseases.
Received: 4 October 1996 / Accepted: 6 December 1996 相似文献
4.
The utilization of radical operation in gastric cancer cases has led to the development of various operation techniques. With the improvement in perioperative management it can be said that age no longer is a restriction. A study of gastric cancer prognosis indicates an upward trend in survival since 1960 along with the increased detection of early cancer. This suggests the most importance of early detection in increasing the therapeutic results obtained in cases of gastric cancer. In cases with advanced cancer, 5-year survival rate of 44.7 per cent was attained through such aggressive actions as extended dissection of lymph nodes and combined resection of surrounding organs with evaluation of the macroscopic classification of the cancer. 相似文献
5.
Shigeo Nakamura Takashi Koshikawa Tsuneko Sato Kayoko Hayashi Taizan Suchi 《Pathology international》1992,42(10):745-750
We describe a 54-year-old woman with primary pulmonary adenocarcinoma showing a characteristic papillary architecture and prominent cilia formation. Immunohistochemically, the tumor cells were positive for carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA) and Leu Ml, and negative for lactoferrin and surfactant apoprotein. An ultrastructural study also indicated differentiation toward bronchial surface epithelial cells. To our knowledge, this type of neoplasm has not been reported as peripheral-type adenocarcinoma of the lung. Acta Pathol Jpn 42: 745–750, 1992. 相似文献
6.
Endotoxin-induced uveitis (EIU) in the rat: A study of inflammatory and immunological mechanisms 总被引:2,自引:0,他引:2
Endotoxin-induced uveitis (EIU) can be produced by systemic injection of endotoxin (ET). It is not clear yet why exclusive ocular involvement occurs in this model. To clarify this question and to establish the sequence of inflammatory events, EIU was induced in Lewis rats by footpad injection of Salmonella ET. Ocular inflammatory response (anterior chamber cells and proteins), aqueous inflammation mediators (thromboxane B2, prostaglandin E2, leukotriene B4 and substance P) and MHC class 2 (Ia) antigen expression in the ciliary body were monitored for 72 hours. Thromboxane B2 was detected early in the aqueous humor, peaking already 1 hour after ET injection. Prostaglandin E2 & leukotriene B4 peaks and a second peak of thromboxane B2 were recorded 18 hours after ET-injection, at the time of maximal ocular inflammation. MHC-class 2 expression was first detected in the ciliary body stroma at the vascular level 6 hours after ET injection and was massively expressed in the ciliary body epithelium at 18 and 72 hours. It is hypothetized that ciliary body endothelium is particularly sensitive to the effect of ET and is the site of thrombocyte adherence. Vascular damage leads in succession to cellular infiltration, release of inflammation mediators and disruption of blood-ocular barrier. MHC-class 2 expression is a secondary phenomenon and is probably at the origin of additional tissue damage from immune effector mechanisms. 相似文献
7.
Abstract: The effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and stroma-free hemoglobin (SFH) on vascular responsiveness to various vasoactive substances were examined in isolated perfused rat kidneys. The kidneys isolated from rats were perfused with 6% PHP, 6% SFH, and 6% hydroxyethylstarch (HES) solution at a constant flow rate. Vascular responsiveness to acetylcholine (ACh), nitroglycerin (NG), norepinephrine (NE), and angiotensin-II (ANG-II) was examined by measuring the perfusion pressure (PP). Effects of inhibition of endothelium-derived relaxing factor (EDRF) by NG -monomethyl L-arginine (L-NMMA) on NE-induced and ANG-II-induced renal vascular responses were examined. ACh and NG induced a dose-dependent decrease in perfusion pressure (PP) in all groups. NE and ANG-II induced an increase in PP in all groups, but NE-induced and ANG-II-induced responses in the PHP-perfused and SFH-perfused groups were significantly larger than those in the HES-perfused group. L-NMMA did not alter vascular responsiveness to NE and ANG-II. These results indicate that PHP and SFH do not inhibit EDRF induced by ACh, but hemoglobin moiety per se does augment the vascular responsiveness to NE and ANG-II in the isolated perfused rat kidney. 相似文献
8.
9.
10.
Myocardial protective effect of lidocaine during experimental off-pump coronary artery bypass grafting. 总被引:1,自引:0,他引:1
Kazuhiro Hinokiyama Nobuo Hatori Masami Ochi Tadaaki Maehara Shigeo Tanaka 《Annals of thoracic and cardiovascular surgery》2003,9(1):36-42
Off-pump coronary artery bypass grafting (OPCABG) has recently gained popularity. During OPCABG, patients remain vulnerable to ischemic-reperfusion injury due to a temporary coronary occlusion without any active cardioprotection. Some strategies such as ischemic preconditioning (IP) and an intracoronary shunt have been applied with a view to minimizing the effects of ischemia, but the effects of these strategies remain controversial. This study was carried out to investigate the protective effect of lidocaine against myocardial ischemic-reperfusion injury. Twenty-one pigs were assigned to three groups, each consisting of seven pigs. In the control group, using a left internal thoracic artery (LITA) bypass circuit, the left anterior descending coronary artery (LAD) was occluded for 45 min followed by two hours of reperfusion. In the IP group, five min of occlusion followed by 15 min of reperfusion was performed. In the lidocaine group, 2 mg/kg of lidocaine was administered directly into the LAD just before the LAD occlusion. Infarct size expressed as a percentage of the area at risk was significantly smaller in the lidocaine group (2.7+/-4.2%) than in the control group (79.9+/-6.0%, p<0.001) or the IP group (57.0+/-25.9%, p<0.001). Lidocaine exhibited a potent myocardial protective effect in the present OPCABG model. 相似文献