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   669篇
  免费   21篇
  国内免费   3篇
耳鼻咽喉   12篇
儿科学   13篇
妇产科学   38篇
基础医学   131篇
口腔科学   8篇
临床医学   65篇
内科学   82篇
皮肤病学   6篇
神经病学   49篇
特种医学   22篇
外科学   48篇
综合类   5篇
预防医学   90篇
眼科学   63篇
药学   33篇
中国医学   6篇
肿瘤学   22篇
  2023年   4篇
  2022年   17篇
  2021年   28篇
  2020年   18篇
  2019年   25篇
  2018年   21篇
  2017年   21篇
  2016年   10篇
  2015年   15篇
  2014年   26篇
  2013年   38篇
  2012年   44篇
  2011年   52篇
  2010年   36篇
  2009年   28篇
  2008年   37篇
  2007年   51篇
  2006年   46篇
  2005年   25篇
  2004年   46篇
  2003年   32篇
  2002年   20篇
  2001年   4篇
  2000年   3篇
  1999年   2篇
  1998年   5篇
  1996年   3篇
  1995年   4篇
  1994年   9篇
  1993年   1篇
  1992年   2篇
  1991年   4篇
  1990年   3篇
  1989年   4篇
  1988年   1篇
  1985年   2篇
  1984年   5篇
  1982年   1篇
排序方式: 共有693条查询结果,搜索用时 0 毫秒
51.

Purpose

To compare diameters of in vivo microwave ablation (MWA) performed in swine kidneys with ex vivo diameters, and to correlate with ablation work (AW), a new metric reflecting total energy delivered.

Material and methods

Eighteen in vivo MWA were performed in 6 swine kidneys successively using one or two antennas (MicroThermX®). Ablation consisted in delivering power (45–120 W) for 5–15 minutes. Ex vivo diameters were provided by the vendors and obtained on bovine liver tissue. AW was defined as the sum of (power)*(time)*(number of antennas) for all phases of an ablation (in kJoules). Kidneys were removed laparoscopically immediately after ablation. After sacrifice, ablations zones were evaluated macroscopically, and maximum diameters of the zones were recorded. Wilcoxon sum rank test and Pearson's correlation were used for comparisons.

Results

For a single antenna (n = 12), the in vivo diameters ranged from 12 to 35 mm, and 15–49 mm for 2 antennas (n = 6). The in vivo diameters remained shorter than ex vivo diameters by 8.6% ± 30.1 on 1 antenna and 11.7% ± 26.5 on 2 antennas (P = 0.31 and 0.44, respectively). AW ranged from 13.5 to 108 kJ. Diameters increased linearly with AW both with 1 and 2 antennas, but only moderate correlations were observed (r = 0.43 [95% confidence interval: ?0.19; 0.81], P = 0.16; and 0.57 [?0.44; 0.95], P = 0.24, respectively).

Conclusion

Although diameters after in vivo renal MWA increased linearly with AW, the moderate correlation and wide standard deviations observed may justify a careful imaging monitoring during treatment delivery and settings adaptation, if needed, for optimal ablation.  相似文献   
52.
Background and objective: Considering the high incidence of cardiovascular disorders in diabetes mellitus and some evidence on the antioxidant and antidiabetic potential of cyanidin-3-glucoside (C3G), this study was conducted to evaluate the possible beneficial effect of C3G administration on vascular reactivity of isolated thoracic aorta in diabetic rats and some of its underlying mechanisms. Materials and methods: Male diabetic rats received C3G (10 mg/kg; i.p.) on alternate days for 8 weeks one week after streptozotocin (STZ) diabetes induction. Results: It was found out that treatment of diabetic rats with C3G exerted a hypoglycaemic effect and attenuated the increased malondialdehyde (MDA) content and reduced the activity of superoxide dismutase (SOD) in aortic tissue. Maximum contractile response of endothelium-intact aortic rings to phenylephrine (PE) was significantly lower in C3G-treated diabetic rats relative to untreated diabetics and endothelium removal abolished this difference. Meanwhile, endothelium-dependent relaxation to acetylcholine (ACh) was significantly higher in C3G-treated diabetic rats as compared to diabetic group. Conclusion: Chronic treatment with C3G may prevent some diabetes-related changes in vascular reactivity observed in diabetic rats directly and/or indirectly due to its hypoglycaemic effect and attenuation of lipid peroxidation and through endothelial-derived factors.  相似文献   
53.
OBJECTIVES: Concerns about unsafe injection practices and possible infections with blood-borne pathogens in the Syrian Arab Republic motivated an assessment of the injection safety situation in the country in July 2001. In light of the recommendations from this assessment, the Ministry of Health of Syria, with the assistance of WHO, implemented a set of activities under the 'Focus Project', which aims to ensure immunization safety. The first phase of the project ran from May 2002 to February 2004, and consisted of the improved provision of injection safety equipment and supplies, the elaboration and wide distribution of national guidelines on injection safety and safe waste management, a behaviour change and communication campaign targeting the general public, and comprehensive training of healthcare workers. A follow-up survey was carried out in February 2004, 2 years after initiation of the project. METHODS: Two representative surveys were conducted using a standardized assessment tool. A cluster sampling strategy, with probability proportionate to the population size, led to the inclusion of 80 health facilities in eight districts in 2001 and of 120 health facilities in 12 districts in 2004. RESULTS: Injection practices had significantly improved 2 years after the start of the project. The 2001 study had pointed to a low, but non-negligible risk to patients (2% unsafe injections), coupled with a high risk to healthcare workers (61% reported needle-stick injuries in the last 12 months) and to the communities owing to unsafe waste disposal (sharps waste found outside 37% of health facilities, waste disposal considered unsafe in 48% of them). The 2004 survey showed that 90% of Syrian healthcare workers had received training in injection safety. All injections observed were given safely (difference to 2001 not significant), although some problems in preparation and reconstitution prevailed. The risk to healthcare workers was significantly reduced as only 14% of the staff reported needle-stick injuries (p < 0.001). The risk to the communities was notably decreased following improvements in sharps waste management (sharps were found in the surroundings of only 13% of health facilities, p < 0.001). CONCLUSIONS: The example of Syria shows that rapid improvement in injection safety is possible and that the necessary tools and methods to monitor and evaluate progress are at our disposal. Challenges remain in transferring this successful programme from the well-structured immunization programme to the more diverse curative health services.  相似文献   
54.
55.
56.
57.
58.
The efficacy of negative pressure wound therapy in the treatment of poststernotomy mediastinitis has been revealed in many reports. The present retrospective observational study examined the efficacy of incisional negative pressure wound therapy in the reconstructive surgery of poststernotomy mediastinitis. We retrospectively examined 1034 consecutive patients, who underwent median sternotomy in the period between October 2013 and September 2015. Mediastinitis developed in 21 patients (2%), who subsequently underwent surgical reconstruction. We applied incisional negative pressure wound therapy (iNPWT) after primary closure of the wound over redon drains in ten patients (iNPWT + redon group). In 11 patients, only redons were used (redons only group). We observed the time between the introduction and removal of redon drains, hospital stay until final wound closure and the rate of failure of treatment. Failure of treatment is defined as the need for further surgical reconstruction. In the iNPWT + redon group, the duration of redon drainage therapy was 6·9 ± 5·2 days versus 13·36 ± 11·58 in the redons only group. Hospital stay was 11·4 ± 8·6 versus 101·64 ± 89·2, and failure of treatment was 10% versus 45·5%, respectively. The primary results of this study appear to support the beneficial effect of iNPWT after radical wound reconstruction.  相似文献   
59.
Purpose: To review the systemic and ocular manifestations of specific emergent viral infectious diseases relevant to the ophthalmologist with particular emphasis on anterior uveitis

Methods: Review of literature.

Results: Arboviral diseases are among the most important emergent and resurgent human infections, occurring mostly in tropical and subtropical zones, but appearing in virtually all regions of the world as a result of climate change, travel, and globalization. Arboviral infections are transmitted to humans by the bite of hematophagous arthropods, mainly mosquitoes. Systemic disease may range from asymptomatic to life-threatening. A wide variety of ocular manifestations, including uveitis, has been reported in association with these emerging viral diseases. Numerous viruses other than arboviruses also have been recently recognized as a potential cause of uveitis.

Conclusions: Proper clinical diagnosis of any emerging infectious disease is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is usually confirmed by detection of virus-specific DNA or antivirus antibodies in serum.  相似文献   
60.
CASE REPORT: An 11-year-old girl diagnosed with Fanconi anemia was referred to us for redness and pain in her right eye. Findings in the right eye included visual acuity of counting fingers, neovascular glaucoma, vitreous hemorrhage, optic disc neovascularization, and features of peripheral ischemic retinopathy. Findings in the left eye included peripheral retinal neovascularization and areas of retinal capillary nonperfusion. COMMENTS: Patients with Fanconi anemia may develop ocular neovascularization with subsequent severe visual loss due to vitreous hemorrhage or neovascular glaucoma. Regular ophthalmic examination, including ophthalmoscopy and fluorescein angiography in selected cases, is recommended in such patients.  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