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   1817篇
  免费   139篇
  国内免费   11篇
耳鼻咽喉   18篇
儿科学   61篇
妇产科学   42篇
基础医学   267篇
口腔科学   24篇
临床医学   143篇
内科学   464篇
皮肤病学   53篇
神经病学   172篇
特种医学   79篇
外科学   283篇
综合类   2篇
一般理论   1篇
预防医学   99篇
眼科学   11篇
药学   106篇
中国医学   2篇
肿瘤学   140篇
  2024年   3篇
  2023年   20篇
  2022年   55篇
  2021年   58篇
  2020年   34篇
  2019年   50篇
  2018年   81篇
  2017年   38篇
  2016年   63篇
  2015年   61篇
  2014年   75篇
  2013年   96篇
  2012年   139篇
  2011年   112篇
  2010年   69篇
  2009年   83篇
  2008年   103篇
  2007年   108篇
  2006年   87篇
  2005年   94篇
  2004年   90篇
  2003年   76篇
  2002年   73篇
  2001年   25篇
  2000年   22篇
  1999年   19篇
  1998年   23篇
  1997年   9篇
  1996年   16篇
  1995年   5篇
  1994年   12篇
  1993年   13篇
  1992年   24篇
  1991年   17篇
  1990年   14篇
  1989年   9篇
  1988年   14篇
  1987年   10篇
  1986年   14篇
  1985年   12篇
  1984年   5篇
  1983年   6篇
  1982年   5篇
  1981年   4篇
  1980年   2篇
  1976年   2篇
  1973年   3篇
  1970年   2篇
  1969年   3篇
  1963年   1篇
排序方式: 共有1967条查询结果,搜索用时 46 毫秒
1.

Background

Available models for predicting lymph node invasion (LNI) in prostate cancer (PCa) patients undergoing radical prostatectomy (RP) might not be applicable to men diagnosed via magnetic resonance imaging (MRI)-targeted biopsies.

Objective

To assess the accuracy of available tools to predict LNI and to develop a novel model for men diagnosed via MRI-targeted biopsies.

Design, setting, and participants

A total of 497 patients diagnosed via MRI-targeted biopsies and treated with RP and extended pelvic lymph node dissection (ePLND) at five institutions were retrospectively identified.

Outcome measurements and statistical analyses

Three available models predicting LNI were evaluated using the area under the receiver operating characteristic curve (AUC), calibration plots, and decision curve analyses. A nomogram predicting LNI was developed and internally validated.

Results and limitations

Overall, 62 patients (12.5%) had LNI. The median number of nodes removed was 15. The AUC for the Briganti 2012, Briganti 2017, and MSKCC nomograms was 82%, 82%, and 81%, respectively, and their calibration characteristics were suboptimal. A model including PSA, clinical stage and maximum diameter of the index lesion on multiparametric MRI (mpMRI), grade group on targeted biopsy, and the presence of clinically significant PCa on concomitant systematic biopsy had an AUC of 86% and represented the basis for a coefficient-based nomogram. This tool exhibited a higher AUC and higher net benefit compared to available models developed using standard biopsies. Using a cutoff of 7%, 244 ePLNDs (57%) would be spared and a lower number of LNIs would be missed compared to available nomograms (1.6% vs 4.6% vs 4.5% vs 4.2% for the new nomogram vs Briganti 2012 vs Briganti 2017 vs MSKCC).

Conclusions

Available models predicting LNI are characterized by suboptimal accuracy and clinical net benefit for patients diagnosed via MRI-targeted biopsies. A novel nomogram including mpMRI and MRI-targeted biopsy data should be used to identify candidates for ePLND in this setting.

Patient summary

We developed the first nomogram to predict lymph node invasion (LNI) in prostate cancer patients diagnosed via magnetic resonance imaging-targeted biopsy undergoing radical prostatectomy. Adoption of this model to identify candidates for extended pelvic lymph node dissection could avoid up to 60% of these procedures at the cost of missing only 1.6% patients with LNI.  相似文献   
2.
Underlining the importance of Profundus Femoral Artery and its capacity to make up for lower limb's haemodynamics during obliterative arteriopathy, the Authors conceive a funnel-shaped intravascular prosthesis, Goretex constructed (PTFE), to introduce, in case of obstruction, in the artery lumen with a suitable instrument. The research is performed through ten oldster dogs whose average weight is twenty-four kilograms. Isolated the deep Femoral Artery and carried out an arteriotomy of about two centimetres on the Common Femoral Artery, we bring the prothesis in Profundis Femoral Artery and we fix it to the wall of the Common Femoral Artery with 8/O microsurgical dots. After thirty days, the arteriographic test shows the patency of the endoprosthesis with normal peripheral flow in nine animals out of ten. By virtue of this preliminary experiment, the Authors point out the semplicity of this intervention, also feasible in local anaesthesia, the good tolerability of the prosthesis and its perfect integration with the surrounding arterious wall, without shifts or dissecting laminar flows between the external prosthesis wall and the vessel lumen of the animal.  相似文献   
3.
4.
beta,beta'-Iminodipropionitrile (IDPN) impairs axonal transport of neurofilaments; their accumulation leads to the formation of proximal swellings in motor axons. Similar proximal swellings are a feature of some cases of motor neuron disease such as amyotrophic lateral sclerosis (ALS). Motor units in IDPN-treated animals were assessed to determine their relative susceptibilities to impaired function and whether the functional changes resulting from proximal axonal swellings share certain electromyographic features with ALS. Intrinsic properties of medial gastrocnemius motoneurones (MN) and contractile responses of their motor units were examined during the evolution of proximal axonal swellings in cats administered IDPN (50 mg/kg once weekly) for 7, 14 or 35 days. While conduction velocities were significantly decreased in all motor unit types by 35 days, the conduction slowing was greater in fast fatigable (types FF and FI) motor units than in fatigue resistant (types FR and S) motor units. Normal correlations between axonal conduction velocity and MN input resistance (Rin) and the inverse relationship between Rin and rheobase were lost with progression of the neuropathy. Twitch and maximum tetanic tension developed by fast-fatigable motor units declined early in the neuropathy, whereas fatigue-resistant units did not show similar changes until later stages of the intoxication. In some motor units, irregular and abnormal tetanic tensions were elicited by repetitive MN discharge. At 14 and 35 days, a novel, intermediate motor unit response classified as slow and fatigable (SF) was observed. Conduction block, characterized by repetitive MN firing without a corresponding contractile response, was observed in some type FF and S units by 35 days. Morphometric analysis of muscle fiber types showed significant atrophy, particularly in the type I fibers at 14-35 days; the atrophy reversed following cessation of IDPN administration. The influence of proximal axonal swellings on motor unit function in IDPN neuropathy is discussed in terms of reported electrophysiological alterations in motoneurone disease.  相似文献   
5.
Murine thymus has been demonstrated to contain both cholinergic receptors and acetylcholinesterase activity. In the present study we have investigated the presence of the enzyme choline acetyltransferase in this organ, which is responsible for the synthesis of acetylcholine. Results reported here demonstrate that (1) an appreciable amount of the enzyme is already present in the thymus on the day of birth; (2) its expression is developmentally regulated; and (3) thymic atrophy, induced in young (2-week-old) and adult (6-week-old) mice by i.p. injection of hydrocortisone for 2 days, is accompanied by significant reduction of choline acetyltransferase activity only in young mice. Altogether these results demonstrate the presence in the murine thymus of functionally relevant markers of the cholinergic system that might interface the interactions between the nervous and immune systems.  相似文献   
6.
Meningeal involvement in leptospiral infection is quite common, usually mild and often overlooked. In contrast, cases of isolated involvement of the central nervous system, including aseptic meningitis, have been reported only rarely. A case of a patient with acute aseptic meningitis caused byLeptospira australis serovarbratislava is reported. This is believed to be the first report of aseptic meningitis due toLeptospira australis. This case indicates the need to consider human leptospirosis in the differential diagnosis of aseptic meningitis.  相似文献   
7.
A wide variety of clinical expressions of the acquired immunodeficiency syndrome (AIDS) has been apparent from the earliest case reports in adult patients and pediatric patients. Both human immunodeficiency virus (HIV) infection and AIDS in children are associated with an increased prevalence of several dermatologic manifestations. In this article we present a review of the recent literature describing the cutaneous manifestations of pediatric AIDS. The cutaneous manifestations of AIDS in children can be divided into three categories: (1) neoplastic manifestations; (2) viral, bacterial and fungal manifestations, and (3) vascular lesions and other manifestations. Pediatricians as well as dermatologists may be the first physicians to recognize and to treat the clinical manifestations of AIDS.  相似文献   
8.
Inflammatory muscle diseases (IMD), including dermatomyositis (DM) and polymyositis (PM), affect skeletal muscle, leading to profound tissue modification. The etiology of IMD is unknown, but multiple steps of the disease pathogenesis have been identified. The main alterations involve the immune response. Cellular infiltrates found in the muscle provide strong evidence for the involvement of a preferential immune mechanism of muscle damage. The pathologic differences found between PM and DM indicate a different role played by cell-mediated and humoral immune alterations. It is well accepted that in the pathogenetic pathway both host genes and environmental factors are involved. Apoptosis, or programmed cell death, is a complex process that plays a key role in many physiological events. It regulates the turnover of immune cells and is one of the mechanisms involved in ensuring a competent, non-autoreactive repertoire of lymphocytes. Apoptosis as a mechanism of muscle fibre death has been described in several neuromuscular disorders and muscular dystrophies, and evidence of a lack of apoptosis in IMD suggests a failure of apoptotic clearance of inflammatory cells playing a role in the maintenance of chronic cytotoxic muscle fibre damage. Most likely, the failure of apoptosis seems to be the main hallmark of the pathogenesis of IMD.  相似文献   
9.
10.
Brucella abortus infection acquired in microbiology laboratories   总被引:2,自引:0,他引:2       下载免费PDF全文
We report an outbreak of laboratory-acquired Brucella abortus infection originating in the accidental breakage of a centrifuge tube. A total of 12 laboratory workers were infected (attack rate of 31%), with an incubation time ranging from 6 weeks to 5 months. Antibody titers were evaluated weekly in all personnel exposed, allowing the diagnosis of the infection in most cases before the onset of clinical symptoms, so that specific therapy could be administrated.  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