首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   391篇
  免费   26篇
耳鼻咽喉   6篇
儿科学   38篇
妇产科学   12篇
基础医学   42篇
口腔科学   23篇
临床医学   36篇
内科学   50篇
皮肤病学   9篇
神经病学   28篇
特种医学   18篇
外科学   49篇
综合类   8篇
预防医学   29篇
眼科学   7篇
药学   39篇
中国医学   4篇
肿瘤学   19篇
  2023年   1篇
  2022年   21篇
  2021年   19篇
  2020年   20篇
  2019年   3篇
  2018年   17篇
  2017年   12篇
  2016年   7篇
  2015年   11篇
  2014年   19篇
  2013年   21篇
  2012年   21篇
  2011年   34篇
  2010年   9篇
  2009年   7篇
  2008年   16篇
  2007年   28篇
  2006年   16篇
  2005年   15篇
  2004年   20篇
  2003年   11篇
  2002年   14篇
  2001年   14篇
  2000年   9篇
  1999年   6篇
  1998年   4篇
  1997年   2篇
  1994年   2篇
  1993年   4篇
  1992年   1篇
  1991年   2篇
  1990年   3篇
  1989年   5篇
  1987年   2篇
  1986年   2篇
  1984年   2篇
  1978年   1篇
  1975年   1篇
  1973年   1篇
  1972年   1篇
  1968年   2篇
  1967年   5篇
  1966年   5篇
  1965年   1篇
排序方式: 共有417条查询结果,搜索用时 0 毫秒
1.
PURPOSE: To examine the application of statistical parametric mapping (SPM) to analyze ictal single-photon emission computed tomography (SPECT) scans in surgical candidates with extratemporal lobe epilepsy. METHODS: The authors selected patients who underwent successful ictal SPECT acquisition in the process of surgical treatment of intractable partial epilepsy. Thirteen patients were identified who met inclusion criteria for confident seizure localization from either intracranial electroencephalogram recordings or epilepsy surgery outcome. In these cases, ictal scans were registered to an in-house-developed normal SPECT atlas composed of 14 spatially normalized brains of normal subjects. SPM96 was used to test on a voxel-by-voxel basis for statistically significant increases in blood flow associated with each patient's ictal scan. The results were then mapped back onto the patient's magnetic resonance image (MRI) for final interpretation. Statistical parametric mapping (SPM) analysis of ictal SPECT scans was compared to both conventional visual interpretation and the analysis of subtraction ictal SPECT co-registered to MRI (SISCOM). RESULTS: Ten of 13 patient scans showed localizing focal ictal increases in regional cerebral blood flow, all of which were concordant with ultimate epilepsy localization. Of the 3 cases not localized with SPM, 1 was localized by conventional visual interpretation and another, not localized by visual interpretation, was correctly localized with SISCOM. Two cases not localized by SISCOM were localized by both visual and SPM analysis. CONCLUSIONS: This work provides supportive evidence for proof of principle that SPM can be used to provide objective, accurate analysis of ictal SPECT scans in patients with extratemporal lobe epilepsy.  相似文献   
2.
Estimation of plasma cortisol by fluorometric technique desorbed by Mallingly's was carried out in 56 cases, including 38 cases of myopia (19 cases of simple myopia and 19 cases of degenerative myopia) and 18 normal individuals. Urinary 17-keto steroids/24 hours was also estimated by Zimmermann technique in 12 out of the 56 cases, which include 8 cases of myopia (4 cases of simple myopia and 4 cases of degenerative myopia) and 4 normal individuals as control. Plasma cortisol level is lower in simple and degenerative myopia than in normal subjects, but on statistical analysis the difference was not of much significance. Patients with simple myopia with positive family history showed lower value of plasma cortisol than patients with simple myopia with negative family history, the difference was also statistically insignificant (P-0.1). In degenerative myopia patients, with and without family history, there was very little difference in plasma cortisol level and statistically highly insignificant (P-0.8). Urinary 17 keto steroid/24 hour values are lower in simple and degenerative myopia than in normal subjects.  相似文献   
3.
4.
Zou  Zhaohui  Bhandari  Junu  Xiao  Baiyan  Liang  Xiaoyue  Zhang  Yu  Yan  Guohui 《Lasers in medical science》2021,36(5):1059-1066
Lasers in Medical Science - The purpose of this study was to evaluate the effect of diode laser irradiation on Enterococcus faecalis (E. faecalis) and its lipoteichoic acid (LTA). Ninety-six...  相似文献   
5.
The present investigation was undertaken to evaluate the potential diuretic activity of Boerhaavia verticillata . The ethanolic and aqueous extracts of B. verticillata were administered in doses of 50 and 100 mg/kg, i.p., to normal and adult albino rats, which were monitored over a period of 24 h. Experimental results confirmed that both the ethanol and aqueous extracts have diuretic properties, but the ethanol extract seems to have less diuretic and natriuretic activity than the aqueous extract.  相似文献   
6.
A middle aged immune-competent woman presented with a facial swelling, which was excised. The histopathology showed it to be a non-caseating granuloma. PCR confirmed that the swelling was caused by mycobacterium other than tuberculosis (MOTT) infection. No relapse was seen on follow up even without chemotherapy.  相似文献   
7.
Atherosclerosis occurs at reproducible sites in the arterial tree and intimal proliferation that leads to bypass graft occlusion also show a well-defined focal distribution. These observations have led to the hypothesis that local blood flow conditions, especially low or fluctuating shear stresses, are important in the development of both disorders. Basic research using both cell culture and animal models has revealed that endothelial cell biology is very sensitive to local shear stresses and rapid progress is being made in characterizing how endothelial cells transduce shear stress. Endothelial sensitivity to shear stress affects control of hemostasis, leukocyte adherence and transmigration, growth factor production, vasomotor responses, endothelial repair and arterial wall remodeling, all of which can be expected to influence development of vascular pathologies. Also, substantial progress has been made in characterizing complex local hemodynamics at relevant arterial sites; however, further progress is needed in this area, as well as in the extrapolation of advances in basic vascular biology to human vascular disease. (Trends Cardiovasc Med 1997;7:111-118). ? 1997, Elsevier Science Inc.  相似文献   
8.
The direct oxidative cleavage of activated alkynes via hydroamination has been described using organic photocatalyst under visible-light irradiation at room temperature. In this reaction, the single electron oxidation of an in situ formed enamine followed by radical coupling with an oxidant finally delivers the oxamate. The key features of this photocatalytic reaction are the mild reaction conditions, metal-free organic dye as a photocatalyst, and TBHP playing a dual role as “O” source and for the regeneration of the photocatalyst.

The direct oxidative cleavage of activated alkynes via hydroamination has been described using organic photocatalyst under visible-light irradiation at room temperature.  相似文献   
9.
10.
Mumps is an acute infectious disease caused by mumps virus, a member of the family Paramyxoviridae. With the implementation of vaccination programs, mumps infection is under control. However, due to resurgence of mumps epidemics, there is a renewed interest in understanding the antigenic diversity of mumps virus. Hemagglutinin-neuraminidase (HN) is the major surface antigen and is known to elicit neutralizing antibodies. Mutational analysis of HN of wild-type and vaccine strains revealed that the hypervariable positions are distributed over the entire length with no detectable pattern. In the absence of experimentally derived 3D structure data, the structure of HN protein of mumps virus was predicted using homology modeling. Mutations mapped on the predicted structures were found to cluster on one of the surfaces. A predicted conformational epitope encompasses experimentally characterized epitopes suggesting that it is a major site for neutralization. These analyses provide rationale for strain specificity, antigenic diversity and varying efficacy of mumps vaccines.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号