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   968篇
  免费   54篇
  国内免费   5篇
耳鼻咽喉   5篇
儿科学   25篇
妇产科学   17篇
基础医学   87篇
口腔科学   23篇
临床医学   78篇
内科学   148篇
皮肤病学   40篇
神经病学   59篇
特种医学   115篇
外科学   154篇
综合类   79篇
一般理论   1篇
预防医学   79篇
眼科学   12篇
药学   56篇
肿瘤学   49篇
  2022年   4篇
  2021年   20篇
  2020年   5篇
  2019年   12篇
  2018年   22篇
  2017年   17篇
  2016年   15篇
  2015年   18篇
  2014年   31篇
  2013年   39篇
  2012年   40篇
  2011年   51篇
  2010年   45篇
  2009年   41篇
  2008年   39篇
  2007年   45篇
  2006年   61篇
  2005年   35篇
  2004年   54篇
  2003年   35篇
  2002年   31篇
  2001年   15篇
  2000年   18篇
  1999年   9篇
  1998年   28篇
  1997年   24篇
  1996年   29篇
  1995年   30篇
  1994年   23篇
  1993年   8篇
  1992年   11篇
  1991年   9篇
  1990年   8篇
  1989年   20篇
  1988年   13篇
  1987年   9篇
  1986年   10篇
  1984年   10篇
  1983年   9篇
  1982年   4篇
  1981年   5篇
  1980年   10篇
  1979年   4篇
  1978年   6篇
  1977年   5篇
  1972年   4篇
  1970年   3篇
  1967年   6篇
  1966年   5篇
  1960年   3篇
排序方式: 共有1027条查询结果,搜索用时 156 毫秒
11.
The teacher-led implementation of healthy eating programs in schools is cost-effective and potentially impactful. Teacher acceptability is important for uptake; however, process evaluations are scarce. This study evaluated the effect of two intensities of teacher training on the evaluation of a vegetable education program for Australian primary schools by teachers. The teachers (n = 65) who implemented the program as part of a cluster RCT (25 schools in two states, New South Wales and South Australia) received either low- (provision with materials and online training) or high (additional face-to-face (F2F) training)-intensity training prior to implementing a 5-week vegetable education program. They evaluated the acceptability of a digital training module and program by indicating the level of agreement with 15 and 18 statements, respectively, using 5-point Likert scales. The average item scores ranged from 3.0 to 4.2. All but one item, including student engagement, alignment to the curriculum and intent for reuse of the program, had a rounded average or median score of 4. The level of training intensity did not impact the teacher acceptability ratings. In conclusion, the teacher acceptability was good, and additional F2F training does not add value above the solely digital training of the teachers.  相似文献   
12.
Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented.  相似文献   
13.
Pheochromocytomas of the bladder are rare neoplasms, constituting <0.06% of all vesical tumours. Common presenting features of this tumour include episodes of sweating, hypertension, haematuria and postmicturition syncope. We describe a case of bladder pheochromocytoma in a 66‐year‐old man whose only symptom of macroscopic haematuria was initially assessed with ultrasonography. Clinical presentation highlights the need for a high index of suspicion during sonographic evaluation of bladder neoplasms because such tumours might present without symptoms of adrenergic excess.  相似文献   
14.
Upham  BL; Kang  KS; Cho  HY; Trosko  JE 《Carcinogenesis》1997,18(1):37-42
Cell to cell communication via gap junctions is essential in the maintenance of the homeostatic balance of multicellular organisms. Aberrant intercellular gap junctional communication (GJIC) has been implicated in tumor promotion, neuropathy and teratogenesis. Oxidative stress has also been implicated in similar pathologies such as cancer. We report a potential link between oxidative stress and GJIC. Hydrogen peroxide, a known tumor promoter, inhibited GJIC in WB-F344 rat liver epithelial cells with an I50 value of 200 microM. Inhibition of GJIC by H2O2 was reversible as indicated by the complete recovery of GJIC with the removal of H2O2 via a change of fresh media. Free radical scavengers, such as t-butyl alcohol, propylgallate, and Trolox, did not prevent the inhibition of GJIC by H2O2, which indicated that the effects of H2O2 on GJIC was probably not a consequence of aqueous free radical damage. The depletion of intracellular GSH reversed the inhibitory effect of H2O2 on GJIC. The treatment of glutathione- sufficient cells with H2O2 resulted in the hyperphosphorylation of connexin43, which is the basic subunit of the hexameric gap junction protein, as determined by Western blot analysis. TPA, a well-known tumor promoter, also inhibits GJIC via hyperphosphorylation of GJIC, which is a result of protein kinase-C activation. However, H2O2 also induced hyperphosphorylation in GSH-deficient cells that had normal rates of GJIC. Therefore, the mechanism of GJIC inhibition must be different from the TPA-pathway and involves GSH.   相似文献   
15.
BACKGROUND: Quality of life (QOL) assessment has emerged to measure and quantify the balance between treatment benefit and toxicity, and has a value in predicting response and overall survival in cancer patients. METHODS: From July 1995 to February 1997, 38 symptomatic patients with advanced non-small cell lung cancer (NSCLC) were treated with MIP chemotherapy (mitomycin 6 mg/m2, ifosfamide 3000 mg/m2 and cisplatin 50 mg/m2 on day 1 every 3 weeks). Patients were assessed for QOL including physical well-being, general symptoms and lung cancer-specific symptoms, as well as objective response. RESULTS: The overall response rate was 38.9% (14/36, all were partial response) and the median duration of response was 3.5 months [95% confidence interval (CI) 2.0-4.0]. The median duration of overall survival was 7 months (95% CI 5.9-8.5). The overall improvement of QOL was 58.3% with 21 patients feeling better on treatment. The toxicity of chemotherapy was mild, mainly nausea/vomiting and minimal alopecia. Using multiple clinical predictors of survival (age, histology, stage, performance status), only change of QOL emerged significantly (P = 0.0007). CONCLUSIONS: MIP had an endurable response and low toxicity profile, and provided good QOL. Integral QOL data in our study provided the strong prediction of survival in advanced NSCLC. Further experienced QOL study will provide greatly enhanced outcome data in clinical trials.   相似文献   
16.
17.
18.
19.
Archives of Women's Mental Health - The purpose of this scoping review was to summarize research that uses linked data to examine peripartum suicidal behaviours and critically appraise studies...  相似文献   
20.
Background The study was performed with an aim to map the pattern of metastasis of squamous cell carcinomas of buccal mucosa to various cervical lymph node levels and analyze its correlation with primary tumor size and histo-pathological grading. Material and Methods 254 patients with squamous cell carcinoma of the buccal mucosa treated with surgery first approach were analyzed retrospectively. The tumor size was noted from pre-operative CT Scans and were divided into early and advanced tumors. The resected specimen was studied to note the histo-pathological grading of the squamous cell carcinoma and the metastatic deposits at various lymph node levels. Results Out of 254 patients (149 females, 105 males), 145 patients showed histo-pathologically proven metastatic deposits in one or more lymph nodes out of which there were 56 patients showing occult metastasis. 78/145 patients showed metastatic involvement of level IB and/or IA lymph nodes, 31 showed involvement of level II and/or I lymph nodes, 27 showed involvement of level III with or without involvement of level I and II and 9 showed metastasis to level IV and V lymph nodes with or without level I, II or III lymph nodes. Cervical lymph node metastasis had statistically significant association with tumor size with advanced tumors showing worse pattern of metastatic spread beyond level I and II lymph nodes. As the degree of differentiation of squamous cell carcinoma reduced, they were more prone for cervical metastasis with moderately and poorly differentiated squamous cell carcinoma showing higher involvement of level III, IV and V lymph nodes. Conclusions The majority of buccal mucosa cases showed metastasis to level I, II and III lymph nodes out of which level IB and/or IA was most frequently involved. Metastasis to level IV and V lymph nodes was rare and was seen especially in patients with advanced primary tumor and poor histo-pathologic differentiation. Key words:Oral squamous cell carcinoma (OSCC), cervical lymph node metastasis, histologic differentiation, locally advanced disease.  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