全文获取类型
收费全文 | 2255篇 |
免费 | 151篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 67篇 |
儿科学 | 54篇 |
妇产科学 | 15篇 |
基础医学 | 302篇 |
口腔科学 | 71篇 |
临床医学 | 118篇 |
内科学 | 538篇 |
皮肤病学 | 80篇 |
神经病学 | 187篇 |
特种医学 | 84篇 |
外科学 | 383篇 |
综合类 | 8篇 |
预防医学 | 29篇 |
眼科学 | 32篇 |
药学 | 135篇 |
中国医学 | 2篇 |
肿瘤学 | 314篇 |
出版年
2023年 | 21篇 |
2022年 | 54篇 |
2021年 | 69篇 |
2020年 | 33篇 |
2019年 | 47篇 |
2018年 | 73篇 |
2017年 | 50篇 |
2016年 | 54篇 |
2015年 | 79篇 |
2014年 | 88篇 |
2013年 | 88篇 |
2012年 | 133篇 |
2011年 | 106篇 |
2010年 | 80篇 |
2009年 | 49篇 |
2008年 | 102篇 |
2007年 | 110篇 |
2006年 | 108篇 |
2005年 | 114篇 |
2004年 | 130篇 |
2003年 | 133篇 |
2002年 | 132篇 |
2001年 | 62篇 |
2000年 | 43篇 |
1999年 | 36篇 |
1998年 | 31篇 |
1997年 | 26篇 |
1996年 | 22篇 |
1995年 | 20篇 |
1994年 | 12篇 |
1993年 | 15篇 |
1992年 | 30篇 |
1991年 | 30篇 |
1990年 | 19篇 |
1989年 | 18篇 |
1988年 | 18篇 |
1987年 | 26篇 |
1986年 | 19篇 |
1985年 | 23篇 |
1984年 | 10篇 |
1983年 | 14篇 |
1982年 | 15篇 |
1980年 | 8篇 |
1978年 | 6篇 |
1976年 | 10篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1971年 | 4篇 |
1969年 | 9篇 |
1968年 | 6篇 |
排序方式: 共有2419条查询结果,搜索用时 15 毫秒
1.
2.
3.
Pharynx and oesophagus evaluation during the swallow using helical computerized tomography. 总被引:2,自引:0,他引:2
PURPOSE: Videofluorography (VF) and endoscopy are commonly used for dynamic imaging (DI) of pharyngeal swallowing but do not offer transverse plane (TP) information. The aim of the present study was to evaluate helical computerized tomography (HCT) to measure the DI capability pharyngeal swallowing in the TP. METHODS: The HCT scan technique used was a single-slice cine mode with scan times of 100 ms. All 15 subjects were studied supine during dry swallow, swallowing of barium sulphate jelly and 3, 10, 15 or 20 ml of a 40% barium sulphate solution. Nine subjects repeated the test twice at more than 1 week's interval to determine the test-retest reliability. RESULTS: Swallowing leads to closure of the vocal folds, pharyngeal constriction and narrowing of the piriform sinuses allowing jelly passage between the sinuses. Laryngeal elevation then occurs with the opening of the pharyngoesophageal segment (PES). Swallowing a bolus of 20 ml produced the maximum anteroposterior and transverse diameters as well as the maximum opening area of the PES. The test-retest intraclass correlation coefficients with liquid deglutition ranged from 0.86 to 0.98. CONCLUSIONS: This study shows that HCT enables visualization of TP of PES complementing VF or endoscopic swallowing studies. 相似文献
4.
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
5.
E Nakashima K Yokogawa F Ichimura T Hashimoto T Yamana A Tsuji 《Journal of pharmaceutical sciences》1987,76(1):10-13
The effects of fasting on the pharmacokinetics of biperiden in rats were examined. Total clearance of biperiden was greater than 90% ascribable to hepatic clearance and was essentially blood-flow dependent. The number of compartments in the preferred pharmacokinetic model of biperiden changed from three (for normal rats) to two (for fasted rats). The smaller mean residence time (MRT) values found for fasted rats were attributable to decreases in distribution volume. Biperiden showed much higher lipophilicity than haloperidol, thiopental, and hexobarbital, and its tissue-to-plasma partition coefficient in adipose tissue was 20-fold higher than that in muscle. The influence of changes in volumes of adipose tissue and muscle on distribution volume (Vdss/BW) was evaluated from tissue-to-plasma partition coefficients. The value of Vdss/BW was predicted to decrease with decrease of adipose tissue, and to increase with decrease of muscle tissue. These results suggest that the observed decrease of Vdss/BW in fasted rats reflects reduced capacity to trap biperiden in the body, especially in adipose tissue. Possible clinical implications of these results are discussed. 相似文献
6.
Takashi Matsuo Itaru Kyoraku Kazutaka Shiomi Seiichiro Sugimoto Huai-Ying Zheng Masamitsu Nakazato 《Clinical neurology》2007,47(1):27-31
A 53-year-old man with adult T-cell leukemia (ATL) developed progressive left hemiparesis and left homonymous hemianopsia. Magnetic resonance imaging (MRI) one month later showed multiple high-intensity lesions in the white matter of both occipital lobes, with predominance in the right side. Detection of JCV genome with polymerase chain reaction in his cerebrospinal fluid subsequently confirmed the diagnosis of progressive multifocal leukoencephalopathy (PML). He was admitted to our hospital. The serum level of soluble interleukin-2 receptor in the patient increased, and both edema and new Gd-enhanced lesions were observed in the cortex of the occipital lobe. He was treated with systemic administrations of Pirarubicin. Cyclophosphamide, and Prednisolone. as well as intrathecal injection of Methotrexate and Cytarabine. Although these treatments temporarily alleviated the symptoms of PML. the ATL spread to the liver and kidney. He died of multiple organ failure. Analysis of his JCV genes revealed that there were three types of rearrangements in the regulatory domains of the JCV genes. All three types lacked the domain B. and two had duplicate domain A. This is the first report of the simultaneous detection of three different types of rearrangements in JCV genes in a single patient. It has been reported that white-matter lesions caused by typical PML are not enhanced in Gd-MRI. However. the lesions seen in this patient were enhanced in Gd-MRI. Such enhancement might be attributable to the modification of the lesions through the direct invasion of ATL cells to the central nervous system. 相似文献
7.
Differential metabolism of (E)-5-(2-iodovinyl)-2'-deoxyuridine (IVDU) by equine herpesvirus type 1- and herpes simplex virus-infected cells 总被引:1,自引:0,他引:1
Thymidine kinase (TK) enzymes encoded by herpes simplex viruses types 1 and 2 (HSV-1, HSV-2), and equine herpesvirus type 1 (EHV-1) catalyze the phosphorylation of thymidine (dThd) and (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU). The replication of HSV-1 is sensitive to BVDU, but the replication of HSV-2 and EHV-1 is not. To investigate the differential sensitivity of the viruses to halogenated vinyldeoxyuridine drugs, the phosphorylation of 125I-labeled (E)-5-(2-iodovinyl)-2'-deoxyuridine (IVDU) was studied. Cytosol enzymes from cells infected by HSV-2 and EHV-1 phosphorylated [125I]IVDU to the monophosphate, IVDUMP, but did not convert IVDUMP to higher di- plus triphosphates (IVDUDP plus IVDUTP) forms. In contrast, enzymes from HSV-1-infected cells converted [125I]IVDU to radioactive IVDUMP and IVDUDP plus IVDUTP. Experiments with mixtures of EHV-1- and HSV-1-induced enzymes showed that the EHV-1 enzyme did not inhibit formation of the IVDUDP plus IVDUTP by the HSV-1 enzyme. With [125I]IVDU as substrate, the Km values for the EHV-1 and HSV-1 TKs were 1.82 and 0.34 microM, respectively, and the Ki (dThd) value for the EHV-1 TK was 0.35 microM. In vivo experiments showed that HSV-1-infected cells converted IVDU to the mono- and the di- plus triphosphate forms. In contrast, EHV-1-infected cells converted IVDU to the monophosphate to a lesser extent than did HSV-1-infected cells, and did not produce the di- plus triphosphates. Thus, inefficient phosphorylation of the monophosphates probably contributes to the insensitivity of EHV-1 replication to IVDU, as it does to the insensitivity of HSV-2 replication to this drug. 相似文献
8.
L K Kullama V Balaraman J R Claybaugh W M Ichimura B E Pichoff K T Nakamura 《Pediatric research》1991,29(3):278-281
We examined the ontogeny of relaxation responses to three categories of calcium channel antagonists, represented by verapamil, diltiazem, and nifedipine, for both potential-operated (KCl-mediated) and receptor-operated channels [norepinephrine (NE)-mediated] in rat thoracic aorta. Aortic rings from 2- to 3-d, 1-wk, and 12-wk-old Sprague Dawley rats were mounted in an organ bath, bathed in Krebs' solution, and connected to a force-displacement transducer to measure isometric tension. Endothelium intact vessels at optimal passive force were exposed to a single ED50 of isotonic KCl or NE, equilibrium contraction was measured, then vessels were washed and exposed for 30 min to 1 microM verapamil, 1 microM diltiazem, or 0.1 microM nifedipine, followed by another dose of KCl or NE. Verapamil and diltiazem demonstrated significant (p less than 0.05) age-related increases in effectiveness for blocking KCl-mediated contraction [(% reduction of control contraction +/- SEM) (Verapamil: 2-3 d, 67.7 +/- 4.2; 1 wk, 72.5 +/- 1.8; 12 wk, 89.5 +/- 1.0. Diltiazem: 2-3 d, 64.6 +/- 2.9; 1 wk, 73.5 +/- 3.0; 12 wk, 83.1 +/- 1.8]. Nifedipine was equally effective at all ages: 2-3 d, 85.6 +/- 1.3; 1 wk, 90.0 +/- 1.6; and 12 wk, 91.3 +/- 1.4. Verapamil and diltiazem also showed significant age-related increases in effectiveness for blocking NE-mediated contraction (Verapamil: 2-3 d, 6.2 +/- 3.9; 1 wk, 28.0 +/- 4.8; 12 wk, 44.1 +/- 6.0. Diltiazem: 2-3 d, 8.0 +/- 3.1; 1 wk, 20.5 +/- 3.9; 12 wk, 46.5 +/- 4.8).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
9.
Itsuo Yokoyama Tadamasa Yoneda Itaru Ichimura Shigehisa Kitagawa Yoshiki Okazaki Hiroshi Takagi 《Surgery today》1986,16(6):460-463
In seven patients undergoing right hemicolectomy for benign or malignant diseases, latero-lateral end anastomoses were made
using stapling devices, LS (linear stapler) and GIA (gastrointestinal anastomosis). As no complications directly related to
the anastomosis occurred, we conclude that anastomosis using stapling devices for right hemicolectomy is a safe and rapid
procedure. 相似文献
10.
We report a case of cortical reflex myoclonus in adult onset Huntington's disease (HD). The patient is a 51-year-old woman. Chorea and myoclonus were observed on her face and extremities. Neurophysiological tests showed C reflex and abnormal waves preceding myoclonus by jerk-locked back averaging method but no giant somatosensory evoked potential. Gene analysis revealed the prolongation of CAG repeats (13/44) in IT15 gene. Oral administration of clonazepam was transiently effective for myoclonus. We should inscribe that the cortical reflex myoclonus may exceptionally manifest in HD. 相似文献