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   1809篇
  免费   114篇
  国内免费   2篇
耳鼻咽喉   48篇
儿科学   55篇
妇产科学   40篇
基础医学   168篇
口腔科学   73篇
临床医学   187篇
内科学   298篇
皮肤病学   11篇
神经病学   156篇
特种医学   133篇
外科学   381篇
综合类   9篇
一般理论   1篇
预防医学   116篇
眼科学   28篇
药学   150篇
中国医学   3篇
肿瘤学   68篇
  2022年   16篇
  2017年   19篇
  2016年   44篇
  2015年   26篇
  2014年   45篇
  2013年   56篇
  2012年   74篇
  2011年   75篇
  2010年   53篇
  2009年   49篇
  2008年   88篇
  2007年   65篇
  2006年   92篇
  2005年   69篇
  2004年   39篇
  2003年   50篇
  2002年   43篇
  2001年   62篇
  2000年   64篇
  1999年   45篇
  1998年   22篇
  1997年   24篇
  1996年   15篇
  1995年   18篇
  1994年   20篇
  1993年   18篇
  1992年   26篇
  1991年   26篇
  1990年   21篇
  1989年   42篇
  1988年   36篇
  1987年   28篇
  1986年   34篇
  1985年   26篇
  1984年   17篇
  1983年   19篇
  1982年   15篇
  1980年   16篇
  1978年   15篇
  1977年   17篇
  1976年   16篇
  1975年   21篇
  1974年   21篇
  1973年   20篇
  1972年   25篇
  1971年   23篇
  1970年   27篇
  1969年   19篇
  1968年   17篇
  1966年   21篇
排序方式: 共有1925条查询结果,搜索用时 9 毫秒
1.
2.
Different doses of hepatitis B virus vaccine—prepared by Korea Green Cross Corporation, were given to healthy infants born to HBsAg-negative mothers at birth, 1 and 6 months of age. A dose of 2 μg was administered intradermally in Group A and, in the three other groups, the vaccine was given intramuscularly (i.m.). An adequate follow-up observation was possible for 9 months after birth in 22, 25, 23 and 21 infants in Groups A, B, C and D, respecvely.
Group C (5 μg, i.m.) produced seroconversion most rapidly, showing the highest rate (96%) at 9 months of age. The lowest seroconversion rate (5%) was found at the age of 1 month in Group A subjects, but the rate increased to 91% after a booster dose was given at 6 months of age.
While it can be concluded that a 5 μg i.m. dose of vaccine at 0, 1 and 6 months of age is optimum for the immunization of infants in efficacy and economy, a 2 μg intradermal dose can also be considered as an immunogenic and economical regimen, though the immune response is slower and a special technique is required for immunization.  相似文献   
3.
Hyalinosis cutis et mucosae (HCM) is a rare autosomal recessive disease of unknown aetiology and pathogenesis. In the skin and mucous membranes there is characteristically a deposition of hyaline-like material in the papillary dermis, around the small blood vessels and around skin appendages. Besides the manifold skin lesions, the mucous membranes affected are found in the nasal and oral cavities, pharynx and larynx. The latter causes the most characteristic symptom, namely, hoarseness, from birth. The lesions of the vessel walls are the most significant histopathological alterations. Ultrastructurally, massive deposits of amorphous, hyaline-like material in the dermis, reduction in number and size of the collagen fibrils and, finally, thickening of the basal laminae could be observed. The findings suggest an abnormal production of noncollagenous proteins as well as the alteration of the lysosomal systems of fibroblasts, endothelial cells and pericytes in the pathogenesis of hyalinosis.  相似文献   
4.
A documentation system that facilitates accurate and complete recording is needed by every obstetric/neonatal nursing service. Developing an individualized system is a major undertaking. However, specific steps can be taken to ease the process. These steps are described, beginning with the assessment phase and concluding with evaluation.  相似文献   
5.
The energy gaps of poly(p-arylenevinylene)s with phenylene, naphthylene and anthrylene subunits are determined by extrapolating the UV/VIS spectroscopic data of the oligomers. The band structure of the three polymers was theoretically investigated. The topology-, geometry- and correlation-factors were determined upon which the energy spectra of this class of one-dimensional π-electron systems depend.  相似文献   
6.
Transbronchial needle aspiration in the diagnosis of bronchogenic carcinoma   总被引:3,自引:0,他引:3  
Transbronchial needle aspiration (TBNA) was performed as a diagnostic procedure in 91 consecutive patients ultimately proven to have bronchogenic carcinoma. Results of TBNA were compared, in the same patients, to the diagnostic yield of cytologic examination of sputum, endobronchial brushings and washings, and endobronchial/transbronchial biopsy. The diagnostic yield for sputum was 13 percent (10 of 75); brushings, 40 percent (34 of 84); washings, 29 percent (26 of 89); biopsy, 56 percent (42 of 75); and TBNA, 45 percent (41 of 91). Aspirates were positive in 35 percent of patients with adenocarcinoma, 41 percent with squamous cell carcinoma, 52 percent with large cell undifferentiated carcinoma, and 55 percent of patients with small cell carcinoma. Carinal aspirates were positive in 54 percent (6 of 11); paratracheal aspirates, 57 percent (13 of 23); parabronchial aspirates, 39 percent (11 of 28); endobronchial, 78 percent (7 of 9), and peripheral mass or solitary pulmonary nodule, 40 percent (17 of 42). The overall diagnostic yield for brushings, washings, and biopsy was 64 percent. The addition of TBNA increased the yield to 71 percent. Bronchogenic carcinoma was diagnosed solely by TBNA in six patients, all with extrabronchial or extratracheal lesions. We conclude that TBNA increases the diagnostic yield of bronchoscopy, particularly in patients with extratracheal and extrabronchial lesions. An equally important observation is that TBNA fails to contribute significantly to the diagnosis of cancer in patients with lesions readily accessible by conventional bronchoscopic techniques. Exceptions to this observation include occasional patients with necrotic endobronchial tumors, submucosal lesions, and rarely patients with peripheral lung nodules or masses.  相似文献   
7.
The case is described of a 58 year old man with systemic Whipple's disease with pericardial and pleural effusions and severe pulmonary hypertension. After three months of antibiotic treatment there was a complete resolution, not only of the symptoms known to be associated with Whipple's disease (diarrhoea, arthralgia, pericardial and pleural effusions), but also of pulmonary hypertension.


  相似文献   
8.
Background: Recent development of extracorporeal magnetic stimulation (ECMS) which uses current‐changing magnetic fields allows the induction of electrical stimulation in the desired deep tissue. Recent study showed the sacral nerve stimulation reduces corticoanal excitability that may play a functional role in anal continence mechanisms. Preliminary study shows that ECMS of sacral nerve can modify pelvic floor function and expel rectal balloon in patients with pelvic floor dyssynergia (PFD). Aims: To evaluate the effect of ECMS compared with biofeedback therapy (BF) in patients with PFD. Methods and Materials: Thirty‐eight patients who fulfilled Rome II criteria for PFD by colon transit time and anorectal function tests, were randomly treated with 8 sessions of ECMS (2/weeks; n = 19) at prone position or BF (2/weeks; n = 19) at sitting position. Stimulation parameters were set at 50–80% of maximum intensity, 10 and 50 Hz frequency, 3 s burst length with 3 and 6 s off using arm‐typed stimulator (BioCom‐1000, Mcube Co., Korea). Symptom scores for constipation with/without anorectal function test were repeatedly measured after each treatment. Response was defined as 50% or more decreased symptom score after treatment (partial response: 30–50%, poor: <30%). Results: Fifteen patients (age 49.1 ± 13.4 years, mean ± SD; 4 men) completed 8 session of BF and 14 patients (54.5 ± 17.6 years, 3 men) completed 8 session of ECMS. Four patients of BF group discontinued treatment due to unsatisfactory therapeutic effect (n = 1) and withdrew consent (n = 3) and 5 patients of ECMS group discontinued treatment because of same reasons (n = 1, 4). Total symptom scores were significantly decreased after treatment of 8 session in both treatment groups (13.4 ± 6.6 vs. 4.3 ± 4.0 for BF, p = 0.009; 14.9 ± 5.6 vs. 3.4 ± 4.0 for ECMS, p < 0.001). Bowel movements per week were also significantly increased after treatment in both groups (median 2 vs. 7 for BF, p = 0.035; median 2 vs. 7 for ECMS, p = 0.008). Thirteen out of 15 patients showed response in BF group and 12 out of 14 showed good response in ECMS group. No adverse effects in both groups. Conclusions: ECMS is as effective as BF for the treatment of PFD. Long‐term effect of ECMS for the patients with pelvic floor dyssynergia need to be evaluated in the near future.  相似文献   
9.
Retrosternal dislocation of the clavicle is an uncommon injury which may affect the mediastinal structures in a life-threatening way. Therefore, computed tomography is mandatory. Manipulation in the acute situation is the treatment of choice. In case of failure or old dislocation, open reduction with stabilization of the joint is required. The literature on this subject has been reviewed and an additional two cases are reported.  相似文献   
10.
Deoxycorticosterone acetate (DOCA) is an agent commonly used to induce hypertension in experimental animals. This form of hypertension is dependent on altered regulation of central pressor mechanisms including the brain renin-angiotensin system. Additionally, there are characteristic changes involving the cardiovascular system and baroreflex responses. This review will discuss aspects of the pathogenesis of DOCA hypertension and the effect of various antihypertensive agents on the development of this form of hypertension.  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