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   226497篇
  免费   10239篇
  国内免费   563篇
耳鼻咽喉   2979篇
儿科学   6847篇
妇产科学   5704篇
基础医学   32510篇
口腔科学   7302篇
临床医学   14351篇
内科学   50838篇
皮肤病学   6945篇
神经病学   18477篇
特种医学   5773篇
外国民族医学   30篇
外科学   27150篇
综合类   1142篇
一般理论   38篇
预防医学   24597篇
眼科学   5305篇
药学   16904篇
  1篇
中国医学   856篇
肿瘤学   9550篇
  2023年   1158篇
  2022年   1697篇
  2021年   4295篇
  2020年   2375篇
  2019年   4380篇
  2018年   6367篇
  2017年   4053篇
  2016年   4188篇
  2015年   4573篇
  2014年   5771篇
  2013年   8492篇
  2012年   13452篇
  2011年   14024篇
  2010年   7443篇
  2009年   6147篇
  2008年   11587篇
  2007年   12261篇
  2006年   11858篇
  2005年   11564篇
  2004年   10673篇
  2003年   9950篇
  2002年   9588篇
  2001年   6851篇
  2000年   7389篇
  1999年   5942篇
  1998年   1528篇
  1997年   1108篇
  1996年   1028篇
  1992年   3117篇
  1991年   2904篇
  1990年   2848篇
  1989年   2485篇
  1988年   2309篇
  1987年   2152篇
  1986年   2160篇
  1985年   2011篇
  1984年   1490篇
  1983年   1299篇
  1979年   1587篇
  1978年   1071篇
  1975年   1152篇
  1974年   1427篇
  1973年   1459篇
  1972年   1374篇
  1971年   1326篇
  1970年   1264篇
  1969年   1325篇
  1968年   1306篇
  1967年   1173篇
  1966年   1068篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
131.
132.
Allergoid immunotherapy is a new form of allergen immunotherapy allowing safe administration of high allergen doses. There is limited information on the effects of allergoid immunotherapy in children with allergic rhinitis. To investigate the immunological and clinical effects of allergoid immunotherapy in children with allergic rhinitis due to grass pollen allergy. Children with allergic rhinitis were assigned to allergoid immunotherapy (n = 27) or control (n = 26, no immunotherapy) groups. Children in the immunotherapy group received seven injections of grass pollen allergoid immunotherapy before grass pollen season and continued to receive maintenance immunotherapy for 27 months. All patients were offered a pharmacotherapy regimen to be used on demand during the pollen seasons. Clinical and laboratory parameters were compared between the immunotherapy and control groups. The rhinoconjunctivitis symptom-medication score and asthma symptom score were lower in the immunotherapy group after 1 yr of maintenance immunotherapy (p < 0.01 for both). Skin test reactivity and nasal reactivity as determined by nasal provocation testing for grass pollen were significantly decreased after 1 yr of immunotherapy (p < 0.001 for both). The seasonal increase in bronchial reactivity and nasal lavage eosinophil cationic protein levels were prevented after the first year of immunotherapy (p < 0.05 for both). The seasonal increase in immunoglobulin (Ig)E decreased (p < 0.05) and grass-specific IgG, IgG(1) and IgG(4) increased significantly already at the end of the seven-injection build-up therapy (p < 0.001, for all). Interleukin (IL)-4 levels in the culture supernatants showed a steady decline from baseline at first and second year of immunotherapy (p < 0.001) but remained unchanged in the control group. Allergoid immunotherapy is an effective method in the treatment of grass pollen-induced allergic rhinitis in children and prevents the seasonal increase in bronchial hyper-reactivity. Changes in specific IgE and IgG levels and decreased IL-4 production in peripheral blood mononuclear cell culture supernatants may account for the observed clinical effects.  相似文献   
133.
134.
Purpose:  To evaluate all consecutive patients treated with infliximab for hidradenitis suppurativa (HS).
Patients and methods:  Within 1 year, all consecutive patients seen in our department for HS (1) resistant to usual medical therapies (2) which could not be easily cured by surgery (3) not treated with new medication within 2 months before inclusion were treated intravenously with infliximab (5 mg/kg) without corticosteroids premedication. Four infusions were planned (week 0, week 2, week 6 and week 10) before the interruption of therapy and follow-up. Clinical activity of HS and quality of life of the patients were assessed immediately before the first, the third and the fourth infusions of infliximab.
Results:  Seven patients were included. Five completed the four infusions. Two patients received only three infusions because of severe side effects. The Sartorius score moderately improved with infliximab (mean score at week 0: 94 ± 39, at week 6: 71 ± 38 and at week 10: 83 ± 48). At week 6, patients judged the efficacy of therapy as marked ( n  = 1), moderate ( n  = 4) or null ( n  = 2). At week 10, five patients were evaluated and judged this efficacy as marked ( n  = 2), moderate ( n  = 2) or null ( n  = 1). The mean Skindex-29 score varied from 22 ± 11 (E: 25 ± 9, S: 13 ± 5, F: 28 ± 12) at week 0 to 18 ± 10 (E: 22 ± 8, S: 12 ± 8, F: 22 ± 12) at week 10.
Conclusion:  The efficacy of infliximab in severe HS is partial. More experience is needed before finding a place for infliximab in the therapeutic armamentarium for HS.  相似文献   
135.
The aim of the study was to evaluate differences in the relationship between peripheral diabetic neuropathy and microvascular reactivity in type 1 and type 2 diabetic patients. Twenty-eight type 1 and 37 type 2 diabetic patients were included in the study. Control groups consisted of 18 and 25, age and body mass index matched healthy persons. The presence of peripheral neuropathy was estimated by vibration perception threshold higher than 20 V evaluated by biothesiometry. Microvascular reactivity was examined by laser doppler fluxmetry using postocclusive reactive hyperemia and thermal hyperemia. The following variables of vascular reactivity were examined: peak flow after occlusion as a difference between maximal and basal perfusion (PORH (max)), mean velocity increase during postocclusive hyperemia (PORH (max)/t (1)), peak flow during thermal hyperemia (TH (max)) and the mean velocity increase in the perfusion during thermal hyperemia (TH (max)/t (2)). These parameters are expressed in perfusion units (PU) or in perfusion units per second (PU . s (-1)). The microvascular reactivity in type 1 diabetic patients without evidence of peripheral neuropathy was comparable with that in healthy persons and it was significantly higher than in type 1 diabetic patients with peripheral neuropathy in all tested parameters (PORH (max): 64 [40; 81] PU vs. 24 [17; 40] PU, p < 0.001, PORH (max)/t (1): 5.41 [2.69; 8.18] PU/s vs. 1.21 [0.69; 2.5] PU/s, p < 0.001, TH (max): 105 [77; 156] PU vs. 56 [46; 85] PU, p < 0.001 and TH (max)/t (2): 2.48 [1.67; 3.33] PU/s vs. 0.87 [0.73; 1.06] PU/s, p < 0.001). On the contrary, no difference in the microvascular reactivity parameters was found between type 2 diabetic patients with and without neuropathy (PORH (max): 48 [30; 60] PU vs. 49 [36; 57] PU, NS, PORH (max)/t (1): 3.46 [2.15; 5.19] PU/s vs. 3.29 [2.45; 4.8] PU/s, NS, TH (max): 95 [78; 156] PU vs. 97 [73; 127] PU, NS and TH (max)/t (2): 1.45 [0.95; 2.84] PU/s vs. 1.37 [1.12; 1.95] PU/s, NS). In both these groups microvascular reactivity was comparable with that estimated in the age and BMI matched healthy persons. An inverse relationship was observed between microvascular reactivity and vibratory perception threshold in type 1 diabetic patients, but it was not true in type 2 diabetic patients. We suppose that the pathogenesis of neuropathy and impaired microvascular reactivity may be differently influenced by metabolic factors in type 1 and type 2 diabetic patients.  相似文献   
136.
OBJECTIVE: Alveolar distraction is a relatively novel procedure by which alveolar bone and underlying mucosa are regenerated. The low predictability of other vertical or horizontal bone regeneration methods has increased interest in this promising technique. This article was designed to review published clinical and experimental results on alveolar distraction, including basic research in other disciplines (maxillofacial and orthopedic distraction) related to or with influence on alveolar distraction. STUDY DESIGN: A review of the international literature was performed to summarize results of clinical and experimental studies on alveolar distraction and on distraction at other anatomical sites that contribute important findings on tissue biology, molecular mechanisms, and other factors that influence and participate in the alveolar distraction process. RESULTS: Research into alveolar distraction has addressed the latency phase, distraction phase, and consolidation phase, yielding highly variable results. Little experimental research has been carried out on this procedure, and most publications are clinical studies with a short follow-up period. Published studies have reported a high rate of complications, attributable to our current lack of understanding of the process. CONCLUSIONS: Definitive conclusions on alveolar distraction are hampered by the lack of clinical and experimental studies to date. Greater knowledge of the factors that influence the distraction process will lead to a more predictable and efficacious distraction technique and a better distractor design.  相似文献   
137.
138.
The increased number of lymphocytes in airways during an asthmatic response is believed to be the result of increased recruitment of these cells. However, it is possible that a decreased apoptotic rate could also contribute to the increased number. The aim of the present study was to investigate whether allergen airway provocation influences the apoptotic phenotype of lung and peripheral blood lymphocytes (PBL) in subjects with atopic asthma. Bronchoalveolar lavage (BAL) lymphocytes and PBL from 12 asthmatic subjects previously challenged with allergen (n = 7) or saline (n = 5) were exposed to the apoptotic stimulus tributyltin (TBT) in vitro and assayed for apoptosis. Airway allergen provocation resulted in decreased sensitivity of BAL lymphocytes to TBT-induced apoptosis, with 42.2% (range 33.9-62.5%) apoptotic cells before challenge versus 23.5% (range 15.3-42.4%) after challenge, while PBL were unaffected. The increased apoptosis resistance correlated with higher numbers of Bcl-2-expressing lymphocytes. Interestingly, baseline caspase-3-like activity was significantly elevated in viable BAL lymphocytes compared with viable PBL, and was unaltered by allergen exposure. In conclusion, allergen inhalation renders bronchoalveolar lavage lymphocytes more resistant to apoptosis while peripheral blood lymphocytes were not influenced at all, indicating that the apoptotic phenotype of airway lymphocytes may play a role in asthmatic inflammation.  相似文献   
139.
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating.  相似文献   
140.
Eye drops contain several ophthalmic medications which can produce allergic reactions. We report the case of a patient with contact dermatitis from neomycin and a probable fixed exanthema after parenteral administration of tobramycin who tolerated topical tobramycin and other aminoglycosides.  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