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   732篇
  免费   47篇
  国内免费   15篇
耳鼻咽喉   4篇
儿科学   43篇
妇产科学   4篇
基础医学   114篇
口腔科学   12篇
临床医学   78篇
内科学   161篇
皮肤病学   16篇
神经病学   14篇
特种医学   117篇
外科学   46篇
综合类   106篇
预防医学   29篇
眼科学   2篇
药学   25篇
中国医学   1篇
肿瘤学   22篇
  2023年   2篇
  2022年   6篇
  2021年   10篇
  2020年   3篇
  2019年   5篇
  2018年   4篇
  2017年   9篇
  2016年   13篇
  2015年   20篇
  2014年   29篇
  2013年   21篇
  2012年   29篇
  2011年   23篇
  2010年   41篇
  2009年   40篇
  2008年   48篇
  2007年   26篇
  2006年   20篇
  2005年   13篇
  2004年   7篇
  2003年   13篇
  2002年   11篇
  2001年   16篇
  2000年   12篇
  1999年   19篇
  1998年   48篇
  1997年   42篇
  1996年   31篇
  1995年   20篇
  1994年   28篇
  1993年   25篇
  1992年   6篇
  1991年   8篇
  1990年   7篇
  1989年   14篇
  1988年   13篇
  1987年   25篇
  1986年   9篇
  1985年   14篇
  1984年   5篇
  1983年   7篇
  1982年   14篇
  1981年   6篇
  1980年   5篇
  1979年   1篇
  1978年   8篇
  1977年   4篇
  1976年   8篇
  1975年   5篇
  1967年   1篇
排序方式: 共有794条查询结果,搜索用时 31 毫秒
41.
42.
43.
44.
45.
Background Post‐inflammatory hyperpigmentation (PIH) is a common occurrence in patients with acne vulgaris, particularly in those with skin of colour. Aims A previous study has demonstrated the benefit of tretinoin (retinoic acid) in the treatment of PIH; however, there is currently no standard protocol to evaluate change in PIH following treatment. Based on these findings, we performed a pilot, exploratory, blinded, intraindividual‐controlled methodology study that consisted of a photographic assessment protocol with facial mapping. Materials and methods The study was based on a secondary analysis of a phase 4, community‐based trial of 544 acne patients who were treated with tretinoin gel microsphere 0.04% or 0.1%. Only patients with Fitzpatrick types III–V (skin of colour) were included in the study; subjects with Fitzpatrick skin type VI were excluded because the photographic assessment did not allow for proper evaluation. Results Despite the small number of subjects evaluated (n = 25), the results revealed consistent assessment of improvement in PIH between two independent graders (weighted κ = 0.84). Conclusion Further study with a larger population is recommended to validate the accuracy of this method.  相似文献   
46.
Remission following an elemental diet or prednisolone in Crohn's disease   总被引:1,自引:0,他引:1  
The short- and long-term effects of an elemental diet in children with acute Crohn's disease were compared with those of prednisolone in historical controls. Clinical remission was induced in 25 of 30 and in 18 of 28 episodes treated for six weeks with an elemental diet and prednisolone. Patients with proximal disease had longer remission after treatment with an elemental diet (p < 0.05) than did patients with colonic disease after treatment with prednisolone (p < 0.01). Disease activity index score improved in both groups compared with the pretreatment scores (p < 0.05). However, the improvement in the elemental diet group was significantly better than in the prednisolone group (p < 0.001). Changes in linear growth were better after treatment with an elemental diet compared with steroids (p < 0.001). Serum albumin and haematocrit concentrations all improved significantly in the children treated with an elemental diet (p < 0.001) but not in those treated with steroids. Thus an elemental diet was better than prednisolone in proximal disease and confirmed improved growth and nutritional status.  相似文献   
47.
Pelvic ultrasound findings in different forms of sexual precocity   总被引:2,自引:0,他引:2  
Recently produced reference curves for various ultrasound dimensions were used to retrospectively assess 67 pelvic ultrasound scans carried out at the initial presentation in girls with sexual precocity. At presentation the group with precocious puberty had significantly increased uterine lengths and ovarian volumes compared with the normal population, and a significantly increased fundal–cervical ratio. Ovarian volume was also significantly increased in thelarche and thelarche variant. The fundal–cervical ratio was significantly increased in thelarche variant. There was considerable overlap between individuals with sexual precocity and normal subjects. The ultrasound findings that best discriminated early or precocious puberty from other forms of sexual precocity were the presence of a midline endometrial echo, and a uterine length above the 97th centile for age. An entirely normal pelvic ultrasound at presentation did not rule out the possibility of precocious puberty.  相似文献   
48.
We report 8 infants with immediate hypersensitivity reactions to foods (milk, egg, or peanut), occurring at the first-known exposure. Each developed symptoms within the first hour, but these generally settled within 2 hours. Sensitisation to the food concerned was demonstrated by positive immediate allergen skin prick tests in every case. Symptoms experienced included irritability, erythematous rash, urticaria, angio-oedema, vomiting, rhinorrhoea, and cough. Five infants were being followed prospectively and 4 were clinically tolerant of the food by age 16 months. The most likely route of sensitisation was via breast milk. None of the infants experienced similar reactions while being breast fed, suggesting that the reaction was dose dependent. As 5 out of a group of 80 infants being followed prospectively developed an immediate reaction at their first known exposure to a food, this appeared to be a not uncommon presentation of food hypersensitivity in infancy.  相似文献   
49.
Subramaniam P  Behari S  Singh S  Jain VK  Chhabra DK 《Surgical neurology》2002,58(5):338-43; discussion 343
BACKGROUND: Intradural subpial lipomas not associated with spinal dysraphism, account for less than 1% of spinal cord tumors. The simultaneous existence of multiple intradural subpial lipomas with dumb-bell extradural extension through the intervertebral foramen in the same patient without any evidence of spinal dysraphism has not been previously reported. CASE DESCRIPTION: A 38-year-old man presented with progressive spastic paraparesis, and weakness of right elbow extension and opposition of the medial three fingers. He also had ascending paraesthesia from the C6 dermatome to the saddle region and loss of joint and position sense of both lower limbs with hesitancy and precipitancy of micturition. There was no spinal tenderness, deformity, neurocutaneous markers, or spinal dysraphism. The total duration of illness was 11 years.The oblique views of the plain radiographs of the cervical spine revealed an enlarged right C7-D1 intervertebral foramen. The T1- and T2-weighted magnetic resonance (MR) images showed two intradural, hyperintense lesions (with extensive loss of signal on fat suppression sequences), one extending from C5 to D2 and the other opposite the C3-4 disc space. The parasagittal and axial images showed the extradural component of the lesion emerging from the right C7-D1 intervertebral foramen.At surgery, a C2 to D2 laminectomy was performed. The lipoma, enclosed in a fine pial membrane, was situated on the right posterolateral aspect of the cord. The right-sided nerve roots from the C6 to D1 levels were completely enmeshed by the lipoma. There was a separate superficial subpial lipoma adherent to the posterior aspect of the cord at the C3-4 level. A distinct area of normal cord was present between the two lesions. A subtotal decompression of the lesions including the component emerging through the right C7-D1 intervertebral foramen and a duraplasty were performed.At follow-up after 18 months, the posterior column impairment, lower limb hypoaesthesia, and right upper limb paraesthesia had improved. However, residual elbow extension and lower limb weakness, mild lower limb spasticity and sphincteric dysfunction persisted. CONCLUSIONS: The multiplicity of intradural subpial lipomas without spinal dysraphism points to a dysembryogenetic basis similar to that seen in patients with spinal dysraphism that results in lipomas, but in which the defect is not severe enough to give rise to coexisting vertebral and soft tissue anomalies. The dumb-bell extradural extension through the intervertebral foramen is extremely rare. The magnetic resonance imaging and surgical principles are discussed.  相似文献   
50.

Background  

Uganda began to implement the prevention of mother-to-child transmission (PMTCT) of HIV programme in 2000, and by the end of 2003 it had expanded to cover 38 of the 56 districts including Mbale District. However, reports from Mbale Hospital showed that less than 10% of pregnant women accepted antenatal HIV testing. We therefore conducted a study to determine the proportion of pregnant women who tested for HIV and the gaps and barriers in PMTCT implementation.  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