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   6606篇
  免费   421篇
  国内免费   87篇
耳鼻咽喉   110篇
儿科学   188篇
妇产科学   88篇
基础医学   849篇
口腔科学   256篇
临床医学   527篇
内科学   1489篇
皮肤病学   215篇
神经病学   352篇
特种医学   448篇
外科学   942篇
综合类   42篇
预防医学   365篇
眼科学   163篇
药学   444篇
中国医学   64篇
肿瘤学   572篇
  2024年   8篇
  2023年   64篇
  2022年   137篇
  2021年   269篇
  2020年   157篇
  2019年   196篇
  2018年   239篇
  2017年   203篇
  2016年   281篇
  2015年   323篇
  2014年   349篇
  2013年   381篇
  2012年   572篇
  2011年   514篇
  2010年   330篇
  2009年   211篇
  2008年   371篇
  2007年   350篇
  2006年   323篇
  2005年   314篇
  2004年   276篇
  2003年   225篇
  2002年   187篇
  2001年   115篇
  2000年   112篇
  1999年   98篇
  1998年   46篇
  1997年   30篇
  1996年   37篇
  1995年   20篇
  1994年   27篇
  1993年   26篇
  1992年   30篇
  1991年   44篇
  1990年   25篇
  1989年   36篇
  1988年   34篇
  1987年   23篇
  1986年   13篇
  1985年   17篇
  1984年   6篇
  1983年   6篇
  1982年   12篇
  1981年   8篇
  1980年   7篇
  1979年   13篇
  1977年   5篇
  1973年   5篇
  1970年   4篇
  1966年   6篇
排序方式: 共有7114条查询结果,搜索用时 15 毫秒
91.

Purpose

Clevudine 30 mg showed potent antiviral activity with a marked post-treatment antiviral effect. However, long-term treatment with clevudine monotherapy induced resistance and myopathy in some cases. The objective of this study is to evaluate the preliminary efficacy and safety of the combination of clevudine 20 mg and adefovir compared to clevudine monotherapy.

Methods

Seventy-four patients were randomized to either a combination of clevudine 20 mg and adefovir or clevudine 20 or 30 mg and were treated for 2 years. The viral kinetics for 24 weeks, virological response [VR; hepatitis B virus (HBV) DNA less than 300 copies/ml], and the biochemical response [BR; normal alanine aminotransferase (ALT)] were assessed.

Results

There was no difference in baseline characteristics among the three groups. Viral kinetics study showed no statistically significant difference among them during 24 weeks. The combination group showed 95 % virological response with a statistically significant difference compared to the clevudine 30 mg (67 %) and 20 mg (71 %) groups (p = 0.0376). Biochemical response rates were similar in all groups (78–94 %). No resistance was reported in the combination group, while 20 % of patients treated with clevudine 30 mg or 20 mg reported resistance during 2 years. Muscle-related symptoms such as myalgia (1 in clevudine 30 mg, 1 in the combination group) and muscle weakness (1 in clevudine 30 mg, 2 in clevudine 20 mg) were reported in five patients (7 %); of these, three patients discontinued the study.

Conclusion

We concluded that the combination of clevudine 20 mg and adefovir produced a potent antiviral response together with a good resistance profile compared to clevudine monotherapy at 96 weeks in this pilot study.  相似文献   
92.
93.
Carbamazepine (CBZ)—an antiepileptic drug—belongs to Biopharmaceutics Classification System II Class. It has low solubility and consequently limited bioavailability. One of the ways to improve drugs solubility is amorphization of their structure. Herein, cooling CBZ—at different cooling rates—was investigated as a way to obtain glassy, better soluble form. During preliminary differential scanning calorimetry experiments, some peculiar behavior of the examined material, different from those stated in the literature, was observed. Further investigations using differential scanning calorimetry, thermogravimetric analysis, and polarizing optical microscope revealed that decomposition temperature of CBZ is about 30°C lower than previously assumed. Moreover, high-resolution thermogravimetric measurements indicate that some decomposition processes could start even below the temperature reported as the melting point of the form I of CBZ.  相似文献   
94.
95.
96.
97.
ABSTRACT: Canalicular adenomas are uncommon, benign epithelial neoplasm of the salivary glands that usually involve the upper lip and the buccal mucosa of elderly people. Differential diagnosis of the canalicular adenoma versus adenocarcinoma is important because it may result in unjustified radiotherapy or extensive and aggressive surgery. Despite the benign nature of canalicular adenomas, complete surgical removal and a regular clinical follow-up are recommended. The current study describes the diagnostic procedures, surgical management, and follow-up of a canalicular adenoma involving the palate of a 79-year-old man.  相似文献   
98.
99.
Do P  Randhawa I  Chin T  Parsapour K  Nussbaum E 《Lung》2012,190(4):463-468

Purpose

Plastic bronchitis is the occlusion of the major bronchial airways by a firm, gelatinous mucoid cast. It is a rare condition, which while classically described in asthma and sickle cell disease has greater mortality in patients with congenital heart disease. The management of this disease is obscure given the lack of clinical data regarding treatment therapies.

Methods

We describe a case of an 11-year-old female status after Fontan surgery who presented with respiratory distress secondary to atelectasis of the right lung.

Results

A bronchoscopy was performed demonstrating an obstructing bronchial cast with successful extraction. The plastic bronchitis continued to recur and she was placed on multiple inhaled mucolytics as well as inhaled tissue plasminogen activator with temporary resolution. Further evaluation of the etiology of her casts revealed that she had elevated pulmonary arterial pressures. Repeated bronchoscopic removal of the casts was utilized as well as continuation of the aggressive airway clearance. Ultimately fenestration of her Fontan was performed along with treatment of pulmonary vasodilators sildenafil and bosentan. Although there was improvement of the cast formation, her airway clearance could only be weaned to four times a day therapy with which she was discharged home after a 3-month hospitalization. She continues to remain on this therapy and has not required hospitalization since the initial incident over 1?year ago.

Conclusions

Plastic bronchitis in a patient with Fontan physiology presents a treatment dilemma that may require comprehensive therapy in severe cases such as described.  相似文献   
100.

Objective

MR perfusion and single photon emission computerized tomography (SPECT) are well known imaging studies to evaluate hemodynamic change between prior to and following superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis in moyamoya disease. But their side effects and invasiveness make discomfort to patients. We evaluated the ivy sign on MR fluid attenuated inversion recovery (FLAIR) images in adult patients with moyamoya disease and compared it with result of SPECT and MR perfusion images.

Methods

We enrolled twelve patients (thirteen cases) who were diagnosed with moyamoya disease and underwent STA-MCA anastomosis at our medical institution during a period ranging from September of 2010 to December of 2012. The presence of the ivy sign on MR FLAIR images was classified as Negative (0), Minimal (1), and Positive (2). Regions were classified into four territories: the anterior cerebral artery (ACA), the anterior MCA, the posterior MCA and the posterior cerebral artery.

Results

Ivy signs on preoperative and postoperative MR FLAIR were improved (8 and 4 in the ACA regions, 13 and 4 in the anterior MCA regions and 19 and 9 in the posterior MCA regions). Like this result, the cerebrovascular reserve (CVR) on SPECT was significantly increased in the sum of CVR in same regions after STA-MCA anastomosis.

Conclusion

After STA-MCA anastomosis, ivy signs were decreased in the cerebral hemisphere. As compared with conventional diagnostic modalities such as SPECT and MR perfusion images, the ivy sign on MR FLAIR is considered as a useful indicator in detecting brain hemodynamic changes between preoperatively and postoperatively in adult moyamoya 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