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   11616篇
  免费   651篇
  国内免费   105篇
耳鼻咽喉   108篇
儿科学   226篇
妇产科学   327篇
基础医学   1491篇
口腔科学   464篇
临床医学   932篇
内科学   2877篇
皮肤病学   139篇
神经病学   970篇
特种医学   473篇
外国民族医学   1篇
外科学   1930篇
综合类   34篇
预防医学   506篇
眼科学   125篇
药学   713篇
中国医学   31篇
肿瘤学   1025篇
  2024年   8篇
  2023年   85篇
  2022年   231篇
  2021年   382篇
  2020年   224篇
  2019年   329篇
  2018年   400篇
  2017年   276篇
  2016年   337篇
  2015年   397篇
  2014年   601篇
  2013年   658篇
  2012年   968篇
  2011年   983篇
  2010年   532篇
  2009年   512篇
  2008年   785篇
  2007年   792篇
  2006年   665篇
  2005年   665篇
  2004年   657篇
  2003年   526篇
  2002年   433篇
  2001年   84篇
  2000年   59篇
  1999年   76篇
  1998年   77篇
  1997年   70篇
  1996年   58篇
  1995年   52篇
  1994年   61篇
  1993年   53篇
  1992年   39篇
  1991年   41篇
  1990年   31篇
  1989年   32篇
  1988年   25篇
  1987年   19篇
  1986年   22篇
  1985年   12篇
  1984年   13篇
  1983年   12篇
  1982年   8篇
  1981年   8篇
  1980年   7篇
  1979年   10篇
  1977年   6篇
  1975年   7篇
  1974年   7篇
  1973年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
BackgroundPancreatoduodenectomies at high risk for clinically relevant pancreatic fistula are uncommon, yet intimidating, situations. In such scenarios, the impact of individual surgeon experience on outcomes is poorly understood.MethodsThe fistula risk score was applied to identify high-risk patients (fistula risk score 7–10) from 7,706 pancreatoduodenectomies performed at 18 international institutions (2003–2020). For each case, surgeon pancreatoduodenectomy career volume and years of practice were linked to intraoperative fistula mitigation strategy adoption and outcomes. Consequently, best operative approaches for clinically relevant pancreatic fistula prevention and best performer profiles were identified through multivariable analysis models.ResultsEight hundred and thirty high-risk pancreatoduodenectomies, performed by 64 surgeons, displayed an overall clinically relevant pancreatic fistula rate of 33.7%. Clinically relevant pancreatic fistula rates decreased with escalating surgeon career pancreatoduodenectomy (–49.7%) and career length (–41.2%; both P < .001), as did transfusion and reoperation rates, postoperative morbidity index, and duration of stay. Great experience (≥400 pancreatoduodenectomies performed or ≥21-year-long career) was a significant predictor of clinically relevant pancreatic fistula prevention (odds ratio 0.52, 95% confidence interval 0.35–0.76) and was more often associated with pancreatojejunostomy reconstruction and prophylactic octreotide omission, which were both independently associated with clinically relevant pancreatic fistula reduction. A risk-adjusted performance analysis also correlated with experience. Moreover, minimizing blood loss (≤400 mL) significantly contributed to clinically relevant pancreatic fistula prevention (odds ratio 0.40, 95% confidence interval 0.22–0.74).ConclusionSurgeon experience is a key contributor to achieve better outcomes after high-risk pancreatoduodenectomy. Surgeons can improve their performance in these challenging situations by employing pancreatojejunostomy reconstruction, omitting prophylactic octreotide, and minimizing blood loss.  相似文献   
74.
75.
Differing contexts have greatly influenced HTA development in various countries, with considerable effort recently made by international HTA networks (e.g., EUnetHTA) and the European Union (EU) to make HTA a more coherent, equal, and efficient process. Medical devices (MDs) present particular challenges for HTA because of frequent, rapid innovation, outcomes influenced by end-user competence, dynamic pricing and often low-quality scientific evidence. Our objective is to describe the development, structure and governance of a National HTA Program for MDs (PNHTADM) in Italy, a highly participatory, stakeholder-engaged, evidence-based process to reform a fragmented system of appraisal and approval. Based largely on EUnetHTA methods, the resulting process delineates a standardized system for proposing MDs by any stakeholders, accrediting HTA producers, setting criteria for prioritization and appraisals, and innovatively linking recommendations with coverage, reimbursement and procurement of MDs. Expected benefits include reduced disparities in pricing and reimbursement policies and improved access to new technologies across 21 regional healthcare systems in Italy's decentralized, universal system, complete with provisions to require additional evidence collection and centrally monitor diffusion. Though devised for Italy, the design, resources and underlying analysis provide a framework for other nations seeking to consolidate HTA initiatives, particularly in light of new EU regulation.  相似文献   
76.
Abstract

Information on children’s diet including bioactive compounds is quite scarce. This observational study investigated the composition of the diet of children living in Parma (Italy; n?=?172, 8–10?years) using 3-day food records completed in winter and spring. Mean daily intakes of food groups, energy and nutrients were obtained using the national food database, while (poly)phenol contents were estimated from Phenol-Explorer or by specific literature searches. Food consumption, energy and nutrient intakes decreased in spring and were partially in line with national data. Adherence to the nutritional recommendations was not satisfied for the majority of nutrients. Main contributors to the phenolic intake were flavonoids (flavan-3-ols) and phenolic acids (hydroxycinnamic acids), while main dietary sources were fruit, chocolate-based products, vegetables, and tea & coffee (decaffeinated). This study provided the first comprehensive analysis of the nutritional composition of children’s diet. Future research should look at the health implications of dietary choices in children.  相似文献   
77.
The epileptic or nonepileptic origin of nocturnal paroxysmal dystonia (NPD) has been debated. We studied three patients with frequent attacks during non-REM sleep. During prolonged video-EEG monitoring, two patients had a convulsive seizure after a typical NPD episode and on these occasions EEG showed epileptiform discharge. In the three patients, attacks occurred repeatedly with different intensity, representing "fragments" of the same seizure. These fragments of the attack could occur periodically every 20-40 s. We postulate that short NPD attacks are actually epileptic seizures originating from the frontal lobes. The rhythmicity of the episodes may be due to rhythmic oscillation of cortical function during non-REM sleep.  相似文献   
78.
79.
To evaluate the prevalence and risk factors for adenomyosis,the clinical records of consecutive women undergoing hysterectomyduring a 3 year period were retrieved. Data were collected onindication for the intervention, general sociodemographic characteristicsof the patients, age at menarche, parity, abortions, and menopausalstatus at surgery. Adenomyosis was diagnosed in 332 of the 1334cases (24.9%). The condition was present in 146 of the 627 patients(23.3%) with fibroids and menorrhagia, 68 of the 265 (25.7%)with prolapse, 21 of the 98 (21.4%) with ovarian cysts, 19 ofthe 100 (19%) with cervical cancer, 31 of the 110 (28.2%) withendometrial cancer, 16 of the 57 (28.1%) with ovarian cancer,and 19 of the 77 (24.7%) with miscellaneous indications. Thesedifferences were not statistically significant (x26 = 11.14).In comparison with nulliparous women, the odds ratio was 1.3and 1.5 respectively in women with one and two births (x21 trend= 5.76, P < 0.05). No relationship was found between ageat surgery, age at menarche, indications for surgery, menopausalstatus at intervention, and presence of endometriosis. Our findingsdo not support the notion that adenomyosis is more frequentlyrelated to particular clinical conditions, and suggest thatparity may be associated with an increased frequency of adenomyosis.  相似文献   
80.
Secretory breast carcinoma is a rare tumor originally described in children and adolescent women with a characteristic morphology and a controversial choice of treatment. We report an additional case of a 4-year-old girl with a breast tumor diagnosed as a secretory carcinoma without involvement of the axillary lymph nodes. The therapy consisted of simple mastectomy and low axillary dissection. She presented with a local recurrence near the surgical scar 8 months later, and a wide elliptical excision of the scar and underlying tissue was performed with subsequent radiotherapy of the surgical bed. This tumor has a relatively benign behavior and rarely metastasizes. A literature review revealed only 22 cases of breast carcinoma in childhood and adolescence. ▪  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