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   1894篇
  免费   105篇
  国内免费   11篇
耳鼻咽喉   18篇
儿科学   50篇
妇产科学   11篇
基础医学   111篇
口腔科学   48篇
临床医学   116篇
内科学   852篇
皮肤病学   14篇
神经病学   57篇
特种医学   62篇
外科学   308篇
综合类   14篇
一般理论   1篇
预防医学   60篇
眼科学   59篇
药学   149篇
中国医学   8篇
肿瘤学   72篇
  2024年   1篇
  2023年   14篇
  2022年   24篇
  2021年   80篇
  2020年   53篇
  2019年   78篇
  2018年   67篇
  2017年   52篇
  2016年   61篇
  2015年   58篇
  2014年   78篇
  2013年   102篇
  2012年   135篇
  2011年   151篇
  2010年   84篇
  2009年   93篇
  2008年   98篇
  2007年   127篇
  2006年   108篇
  2005年   104篇
  2004年   98篇
  2003年   71篇
  2002年   53篇
  2001年   33篇
  2000年   49篇
  1999年   26篇
  1998年   14篇
  1997年   8篇
  1996年   7篇
  1995年   6篇
  1994年   2篇
  1993年   4篇
  1992年   12篇
  1991年   13篇
  1990年   5篇
  1989年   6篇
  1988年   12篇
  1987年   6篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1981年   2篇
  1978年   1篇
  1977年   1篇
  1973年   1篇
  1970年   1篇
  1969年   2篇
  1966年   1篇
  1962年   1篇
排序方式: 共有2010条查询结果,搜索用时 15 毫秒
31.
OBJECTIVES: We evaluated the effect of plaque burden modification (debulking) on the short- and long-term clinical outcomes of patients with a totally occluded native coronary artery undergoing successful stent deployment. BACKGROUND: Although the primary success rate of crossing a chronic totally occluded coronary artery has improved with the development of new interventional devices and guidewires, the rate of acute reocclusion and restenosis remains high. METHODS: The in-hospital and late clinical outcomes of 150 patients who had undergone successful stenting of 176 chronic total occlusions were analyzed. After successful crossing of the lesion, 44 patients with 50 lesions underwent debulking by laser angioplasty, rotational or directional atherectomy followed by stenting, whereas 106 patients with 126 lesions underwent stent implantation without prior debulking. RESULTS: Baseline clinical and angiographic characteristics were similar for the two groups, except for a higher incidence of left anterior descending coronary artery location and longer lesions in the group of patients who underwent debulking prior to stenting. In-hospital mortality, myocardial infarction and repeat angioplasty rates were similar for the two groups. At a mean 14 +/- 8 months follow-up time, there were no deaths in either group, and target lesion revascularization rates were the same (16.3% in the debulking plus stent group vs. 14.4% in the stent alone group, p = NS). CONCLUSIONS: Treatment of chronic total native coronary artery occlusions with stent deployment with and without lesion modification (debulking) results in a favorable in-hospital outcome, with relatively low long-term target lesion revascularization rates.  相似文献   
32.

Background

Age is a strong independent predictor of outcomes after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). Whether lower rates of reperfusion success contribute to the poor prognosis in elderly patients is unknown.

Methods

A formal ST-segment analysis substudy was performed in 695 patients undergoing primary PCI for AMI in the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial. Reperfusion success (determined by the magnitude of ST-segment elevation resolution [STR] after PCI) was evaluated in 4 age groups: <50 years (n = 163), ≥50 to <60 years (n = 187), ≥60 to <70 years (n = 194), and ≥70 years (n = 151).

Results

There were no differences in the age groups for angiographic procedural success >91% in all, P = .6), postprocedural Thrombolysis in Myocardial Infarction grade 3 flow >94%, P = .8), and the proportions of patients with complete, partial, or absent STR (P >.8). However, rates of 30-day mortality (0.6%, 1.1%, 3.6%, 6.0%, respectively) and major adverse cardiac events (MACE; 2.5%, 4.8%, 6.2% 9.3%, respectively) increased with age. Rates of mortality and MACE were also inversely related to the magnitude of STR. Absent STR (hazard ratio, 3.00; 95% CI, 1.37-6.58; P = .006) and age (hazard ratio, 1.34; 95% CI, 1.01-1.77; P = .04) were independent predictors of 30-day MACE by using multivariable modeling.

Conclusions

Lack of effective myocardial reperfusion is not a contributory mechanism responsible for the high morbidity and mortality rates observed in elderly patients. Nevertheless, advanced age and absent STR are both independent predictors of adverse outcomes after primary PCI, emphasizing the importance of successful reperfusion in the elderly population.  相似文献   
33.
OBJECTIVES: We analyzed the effects of vascular brachytherapy (VBT) on ostial in-stent restenosis (ISR). BACKGROUND: In-stent restenosis has a high recurrence rate after percutaneous reintervention. The recurrence rate of ostial ISR lesions and the impact of VBT remain unknown. METHODS: We evaluated 133 patients with native coronary ostial ISR from a pooled database of 990 patients enrolled in randomized VBT trials. Independent quantitative angiography was performed at baseline and follow-up in 45 gamma, 27 beta, and 61 placebo patients. RESULTS: Binary restenosis was significantly higher in placebo than radiated patients (75.4% vs. 17.8% in gamma vs. 22.2% in beta, p < 0.0001). The treatment effect of both gamma (odds ratio [OR] 0.06; 95% confidence interval [CI] 0.02 to 0.17) and beta VBT (OR 0.10; 95% CI 0.03 to 0.31) was maintained after controlling for differences in baseline lesion length. Proximal and distal radiation edge restenosis rates were similar among the groups. Vascular brachytherapy of true aorto-ostial lesions (n = 34) was similarly beneficial: restenosis rates of placebo versus gamma or beta patients of 83.3% versus 6.7% versus 28.6%, p = 0.0002. CONCLUSIONS: Conventional treatment of ostial ISR is associated with a recurrence rate of over 75%. Vascular brachytherapy with either gamma or beta sources results in significant and similar reductions in restenosis compared with placebo. Similar benefits after VBT prevail in true aorto-ostial lesions.  相似文献   
34.

Background

Periacetabular osteotomy (PAO) is the treatment of choice for younger patients with developmental hip dysplasia. The procedure aims to normalize the joint configuration, reduce the peak-pressure, and delay the development of osteoarthritis. The procedure is technically demanding and no previous study has validated the use of computer navigation with a minimally invasive transsartorial approach.

Methods

Computer-assisted PAO was performed on ten patients. Patients underwent pre- and postoperative computed tomography (CT) scanning with a standardized protocol. Preoperative preparation consisted of outlining the lunate surface and segmenting the pelvis and femur from CT data. The Biomechanical Guidance System was used intra-operatively to automatically calculate diagnostic angles and peak-pressure measurements. Manual diagnostic angle measurements were performed based on pre- and postoperative CT. Differences in angle measurements were investigated with summary statistics, intraclass correlation coefficient, and Bland–Altman plots. The percentage postoperative change in peak-pressure was calculated.

Results

Intra-operative reported angle measurements show a good agreement with manual angle measurements with intraclass correlation coefficient between 0.94 and 0.98. Computer navigation reported angle measurements were significantly higher for the posterior sector angle (\(1.65^{\circ }\), \(p=0.001\)) and the acetabular anteversion angle (\(1.24^{\circ }\), \(p=0.004\)). No significant difference was found for the center-edge (\(p=0.056\)), acetabular index (\(p=0.212\)), and anterior sector angle (\(p=0.452\)). Peak-pressure after PAO decreased by a mean of 13% and was significantly different (\(p=0.008\)).

Conclusions

We found that computer navigation can reliably be used with a minimally invasive transsartorial approach PAO. Angle measurements generally agree with manual measurements and peak-pressure was shown to decrease postoperatively. With further development, the system will become a valuable tool in the operating room for both experienced and less experienced surgeons performing PAO. Further studies with a larger cohort and follow-up will allow us to investigate the association with peak-pressure and postoperative outcome and pave the way to clinical introduction.
  相似文献   
35.

Background

Regardless of different sources, methods or devices which are applied for preparation of therapeutic platelets, these products are generally isolated from whole blood by the sedimentation techniques which are based on PRP or buffy coat (BC) separation. As a general fact, platelet preparation and storage are also associated with some deleterious changes that known as platelet storage lesion (PSL). Although these alternations in platelet functional activity are aggravated during storage, whether technical issues within preparation can affect integrin activation and platelet adhesion to fibrinogen were investigated in this study.

Methods

PRP- and BC-platelet concentrates (PCs) were subjected to flowcytometry analysis to examine the expression of platelet activation marker, P-selectin as well as active confirmation of the GPIIb/IIIa (αIIbβ3) on day 0, 1, 3 and 5 post-storage. Platelet adhesion to fibrinogen matrix was evaluated by fluorescence microscopy. Glucose concentration and LDH activity were also measured by colorimetric methods.

Results

The increasing P-selectin expression during storage was in a reverse correlation with PAC-1 binding (r?=??0.67; p?=?.001). PRP-PCs showed the higher level of P-selectin expression than BC-PCs, whereas the levels of PAC-1 binding and platelet adhesion to fibrinogen matrix were significantly lower in PRP-PCs. Higher levels of active confirmation of the GPIIb/IIIa in BC-PCs were also associated with greater concentration of glucose in these products.

Conclusion

We demonstrated the superior capacities of integrin activation and adhesion to fibrinogen for BC-PCs compared to those of PRP-PCs. These findings may provide more advantages for BC method of platelet preparation.  相似文献   
36.
37.
38.
Clinical Rheumatology - Adult-onset Still’s disease (AOSD) characterized by a high spiking fever, skin rash, arthritis, and leukocytosis. The aim of the present study was considering the...  相似文献   
39.
BACKGROUND: Mycobacterium tuberculosis infection has been shown to be associated with anthracotic bronchitis. However, the typical manifestation of infection is not usually present in infected patients, which raises the question of whether a particular strain of M. tuberculosis is associated with this group of patients. OBJECTIVE: To determine whether a particular strain of M. tuberculosis is associated with anthracotic bronchitis. DESIGN: We assessed the predominant space oligonucleotide (spoligotype) patterns of M. tuberculosis complex isolated from patients with anthracotic bronchitis and compared the results with tuberculosis (TB) subtype patterns in Iran and other countries. RESULTS: During a 7-month period (April--October 2006), we enrolled 87 patients (30 men and 57 women) with anthracotic bronchitis, 26% (n = 23) of whom had TB. Spoligotyping of M. tuberculosis among these 23 patients showed four distinct patterns: East-African-Indian (11, 47.8%) and Central-Asian (7, 30.4%), Haarlem I (4, 17.4%) and T-1 (1, 4.3%). When compared with spoligotype patterns of M. tuberculosis in Middle Eastern countries, including Iran, anthracotic bronchitis had similar patterns. CONCLUSION: Our results indicate that the atypical manifestations of TB in anthracotic patients are not caused by any particular subtypes of M. tuberculosis. We conclude that anthracotic bronchitis is actually an atypical presentation of tuberculous infection with common subtypes inside the bronchial mucosa.  相似文献   
40.

Purpose

Proteasome inhibition has been shown to be effective in multiple myeloma and solid tumor models. In this in vitro study, we investigated the antitumor effect of bortezomib (Velcade®) in squamous cell carcinoma of the head and neck (SCCHN) cell lines and examined the interaction of the drug with docetaxel (TAX) and cisplatin (CDDP).

Methods

Dose escalation studies were performed with eight squamous cell carcinoma cell lines using bortezomib alone or in combination with TAX or CDDP. Growth inhibitory and proapoptotic effects were measured quantitatively using cytohistology and western blot analysis.

Results

Bortezomib alone showed a significant antiproliferative activity in all SCCHN cell lines (P = 0.012), and the activity was further enhanced by the addition of TAX or CDDP (P ≤ 0.036). When the combination of bortezomib and CDDP was used, the dose of the latter could be reduced to yield the same antiproliferative effect as the cytotoxic drug alone (P < 0.012).

Conclusions

Our results indicate that bortezomib increases the cytotoxic activity of TAX and CDDP in SCCHN cell lines. In vivo and in the clinical setting, the addition of bortezomib may allow to reduce the doses of TAX or CDDP to decrease the systemic toxicity of these drugs.
  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