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   3296篇
  免费   136篇
  国内免费   18篇
耳鼻咽喉   116篇
儿科学   142篇
妇产科学   112篇
基础医学   214篇
口腔科学   208篇
临床医学   286篇
内科学   588篇
皮肤病学   23篇
神经病学   190篇
特种医学   259篇
外科学   786篇
综合类   56篇
一般理论   1篇
预防医学   95篇
眼科学   67篇
药学   133篇
中国医学   6篇
肿瘤学   168篇
  2023年   29篇
  2022年   44篇
  2021年   88篇
  2020年   53篇
  2019年   63篇
  2018年   111篇
  2017年   84篇
  2016年   119篇
  2015年   110篇
  2014年   169篇
  2013年   180篇
  2012年   226篇
  2011年   210篇
  2010年   112篇
  2009年   106篇
  2008年   197篇
  2007年   250篇
  2006年   218篇
  2005年   207篇
  2004年   209篇
  2003年   159篇
  2002年   139篇
  2001年   77篇
  2000年   58篇
  1999年   56篇
  1998年   24篇
  1997年   11篇
  1996年   18篇
  1995年   9篇
  1994年   5篇
  1992年   18篇
  1991年   7篇
  1990年   5篇
  1989年   3篇
  1988年   8篇
  1987年   5篇
  1985年   4篇
  1981年   3篇
  1979年   5篇
  1978年   3篇
  1977年   2篇
  1976年   3篇
  1974年   3篇
  1972年   4篇
  1970年   2篇
  1969年   4篇
  1968年   2篇
  1967年   2篇
  1966年   4篇
  1955年   2篇
排序方式: 共有3450条查询结果,搜索用时 31 毫秒
1.
Different methods have been used throughout the years for syndesmotic injury but there is no consensus on the ideal treatment. Some methods are expensive and some have more complications. The aim of this study is to compare single suture endobutton with double suture endobutton and screw fixation for syndesmotic injury.Sixty nine patients with syndesmotic injury with fibular fractures whom were treated with a single interosseous suture endobutton system (ZipTightTM, Zimmer Biomet), a double interosseous suture endobutton system (ZipTightTM, Zimmer Biomet) and 1 syndesmotic screw (TST, Istanbul, Turkey) were included in this study. Functional and radiological results from patient records between 2015 and 2018 were retrospectively evaluated.Twenty patients were treated with the double interosseous suture endobutton, 23 were treated with the single interosseous suture endobutton, and 26 were treated with traditional AO screw fixation. Three patients from the screw fixation group (11.5%) required revision surgery (P < .05). All the radiologic and clinical outcomes were statistical similar in all 3 groups.Our findings showed that the interosseous suture endobutton system is at least as safe as the screw fixation technique for treatment of syndesmosis joint injuries and can be used as an alternative to the screw method. The interosseous suture endobutton system eliminates the need for a second surgery to remove the hardware, which minimizes the probability of re-diastasis. Since our results showed no statistical difference between single and double interosseous suture endobutton systems, the less costly single endobutton system may be the better alternative.  相似文献   
2.

Background

There is a need for a peripheral nerve model on which surgeons-in-training can simulate the repair of nerve injuries at their own pace. Although practicing on animal models/cadavers is considered the “gold standard” of microsurgical training, the proposed model aims to provide a platform for improving the technical skills of surgical trainees prior to their practice on cadaver/animal models. In addition, this model has the potential to serve as a standardized test medium for assessing the skill sets of surgeons.

Methods

Several formulations of silicone were utilized for the design and fabrication of a model which realizes the hierarchical structure of peripheral nerves. The mechanical properties were characterized via the Universal Testing Machine; the damage caused by the needle on the entry sites was assessed through scanning electron microscopy (SEM).

Results

Mechanical properties of the formulations of silicone were tested to mimic human peripheral nerves. A formulation with 83.3?wt% silicone oil and 0.1?wt% cotton fiber was chosen to be used as nerve fascicles. Both 83.3?wt% silicone oil with cotton fiber and 66.6?wt% silicone oil without fiber provided a microsuturing response similar to that of epineurium at a wall thickness of 1?mm. SEM also confirmed that the entry of the needle did not introduce significant holes at the microsuturing sites.

Conclusions

The proposed peripheral nerve model mimicked human tissues mechanically and cosmetically, and a simulation of the repair of a fifth-degree nerve injury was achieved.  相似文献   
3.
4.
5.
6.
7.
The case of a child injured by a knitting needle penetrating transorbitally and intracranially, resulting in carotid cavernous fistula and pontine injury, is reported. After receiving medical and endovascular treatment, the only remaining abnormal neurological manifestation was right peripheral facial nerve palsy. The clinical sequences of events and the demonstration of a pontine lesion leading to peripheral facial palsy are presented. Facial nuclear injury with a penetrating trauma is an extremely rare condition. It is important to identify the anatomical regions injured in penetrating traumas. The lesions must be identified by computerized tomography, magnetic resonance imaging, clinical and laboratory investigation.  相似文献   
8.
Epidemiologic evidence suggests that a full-term pregnancy may affect maternal risk of breast cancer later in life. The objective of this cross-sectional study was to compare circulating levels of maternal hormones affecting breast differentiation (human chorionic gonadotropin and prolactin) and proliferation [alpha-fetoprotein, insulin-like growth factor I (IGF-I), and estradiol] between women at a low to moderate risk (Asians and Hispanics), as compared with women at a high risk for breast cancer (Caucasians and African-Americans). Between May 2002 and December 2004, a total of 586 pregnant women were approached during a routine prenatal visit. Among them, 450 women (206 Caucasian, 126 Asian, 88 Hispanic, and 30 African-American) met the inclusion criteria and signed the informed consent. Only singleton pregnancies were considered. Blood samples were drawn during the second trimester of pregnancy. Laboratory analyses were done using the IMMULITE 2000 immunoassay system. Gestational age standardized mean levels of estradiol, IGF-I, and prolactin were significantly higher in Hispanic women compared with Caucasian women. Mean concentration of IGF-I was significantly higher in African-American women compared with Caucasian and Asian women. No significant differences in pregnancy hormone levels were observed between Caucasian and Asian (predominantly second-generation Chinese) women in this study. Irrespective of ethnicity, women who had their first pregnancy had substantially higher mean levels of alpha-fetoprotein, human chorionic gonadotropin, estradiol, and prolactin compared with women who previously had at least one full-term pregnancy. These data suggest that circulating pregnancy hormone levels may explain some of the ethnic differences in breast cancer risk.  相似文献   
9.
Regional cerebral blood flow was investigated in 14 patients with major depression diagnosed according to the DSM-III-R criteria (six patients with single and eight patients with recurrent episodes) and in ten healthy volunteers. The mean ages of the patients and the controls were 33.5 ± 2.7 and 31.6 ± 2.6 years, respectively. The severity of the depression was assessed using the 17-item Hamilton Depression Scale (mean: 23.2 ± 1.5). None of the patients was under medication. After administration of 500 MBq technetium-99m hexamethylpropylene amine oxime, a single photon emission tomography study was performed and then transaxial, sagittal and coronal slices were obtained. For the semiquantitative analysis of the data, the ratios of the mean counts/pixel to the whole slice were calculated for 24 regions on three consecutive transaxial slices in the orbitomeatal plane. Additionally, left/right and frontal/occipital ratios were calculated. Both sides of the temporal region had a significantly decreased cerebral blood flow (CBF) when compared to the controls. The left/right ratio of the prefrontal region was also significantly lower in the patients than in the controls. The Hamilton score had a negative correlation with blood flow in the anterofrontal and left prefrontal regions. According to our results, regional CBF seems to be decreased in the left prefrontal and in both temporal regions in major depression. The severity of depression is correlated with the reduction in CBF in the regions of the anterofrontal and left prefrontal cortex.  相似文献   
10.
Severe middle vault deformity with disturbed nasal form and function is one of the most challenging procedures to correct in a secondary rhinoplasty. Reconstructing the deformity with autologous septal cartilage would be the primary choice of most surgeons, if it were always available. However in certain cases the lack of a sufficient quantity of autologous cartilage has forced surgeons to explore other viable options. This paper discusses our experience with the combined use of spreader and dorsal onlay grafts from various materials in the reconstruction of severe middle vault deformity in 110 patients. In follow up, (between 6 and 42 months; mean 21 months) all patients were noted to have improved in both aesthetics and function with no major complications noted. In summary, this study proposes that any engrafting material can be used safely when the proper surgical principals and technique are employed.  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