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   1313篇
  免费   62篇
  国内免费   11篇
耳鼻咽喉   11篇
儿科学   13篇
妇产科学   17篇
基础医学   184篇
口腔科学   13篇
临床医学   93篇
内科学   321篇
皮肤病学   15篇
神经病学   87篇
特种医学   37篇
外科学   284篇
综合类   10篇
预防医学   69篇
眼科学   28篇
药学   85篇
中国医学   2篇
肿瘤学   117篇
  2023年   8篇
  2022年   37篇
  2021年   63篇
  2020年   30篇
  2019年   29篇
  2018年   38篇
  2017年   16篇
  2016年   20篇
  2015年   36篇
  2014年   36篇
  2013年   59篇
  2012年   104篇
  2011年   140篇
  2010年   53篇
  2009年   34篇
  2008年   75篇
  2007年   70篇
  2006年   64篇
  2005年   66篇
  2004年   47篇
  2003年   43篇
  2002年   33篇
  2001年   19篇
  2000年   27篇
  1999年   19篇
  1998年   16篇
  1997年   10篇
  1995年   9篇
  1994年   5篇
  1992年   7篇
  1990年   12篇
  1989年   11篇
  1988年   10篇
  1987年   5篇
  1986年   9篇
  1985年   10篇
  1984年   5篇
  1979年   4篇
  1978年   4篇
  1977年   7篇
  1976年   8篇
  1975年   12篇
  1974年   7篇
  1973年   10篇
  1972年   6篇
  1971年   13篇
  1970年   4篇
  1969年   5篇
  1968年   8篇
  1966年   4篇
排序方式: 共有1386条查询结果,搜索用时 15 毫秒
91.
OBJECTIVE: While it is technically feasible to conduct migraine research on the Internet, can one be sure that the subjects who participate actually have the disorder? We examined this issue in 109 sequential subjects in an Internet study of migraineurs' symptoms. BACKGROUND: The increasing use of the Internet by the US population provides an opportunity for using this medium in clinical research, but, to be useful, the results of such research must be valid and generalizable. METHODS: Using postings to Internet newsgroups of migraineurs, we recruited subjects to a migraine research site. We examined reported symptoms by comparing them with the International Headache Society's criteria for diagnosis of migraine and by subjective review by a neurologist. We also attempted to contact the subject's primary care physicians to confirm their diagnosis. RESULTS: We found considerable evidence for the validity of the participants' self-reported diagnoses. Most subjects with professed migraine reported quality of pain (97%) and associated symptoms (92%) consistent with that diagnosis, and review of their symptoms and questionnaire responses by the neurologist suggested that almost all subjects (97%) had migraine. Personal physicians confirmed a diagnosis of migraine in 90% of consenting subjects (n=49). CONCLUSIONS: The validity of self-reported diagnosis of migraine does not appear to be an obstacle to conducting research in subject populations on the Internet.  相似文献   
92.
93.
94.
Urine and serum neopterin concentrations are now widely used to monitor patients with HIV-1 infection. However, there are no published studies comparing the levels in urine and serum, and relating both to the patients' immune status. Urine and serum neopterin concentrations correlated closely in our study population of 37 HIV-1 seropositive patients (34 homosexuals, 3 drug addicts) and 10 HIV-1 seronegative homosexuals. Our data further show that urine and serum neopterin concentrations correlate almost identically with the clinical and immunological presentation of HIV-1 infected individuals, as expressed by the Walter Reed Staging classification. In addition, there was no difference between the correlation of neopterin concentrations in either serum or urine with the Quetelet indices. It will depend on the clinical situation whether blood or urine sampling is preferred. Collection and handling of urine samples from HIV infected patients is less risky to health care personnel in HIV settings.  相似文献   
95.
96.

Background

Intrahepatic cholangiocarcinoma with hepatic hilus involvement has been either classified as intrahepatic cholangiocarcinoma or hilar cholangiocarcinoma. The present study aimed to investigate the clinicopathologic characteristics and short- and long-term outcomes after curative resection for hilar type intrahepatic cholangiocarcinoma in comparison with peripheral intrahepatic cholangiocarcinoma and hilar cholangiocarcinoma.

Methods

A total of 912 patients with mass-forming peripheral intrahepatic cholangiocarcinoma, 101 patients with hilar type intrahepatic cholangiocarcinoma, and 159 patients with hilar cholangiocarcinoma undergoing curative resection from 2000 to 2015 were included from two multi-institutional databases. Clinicopathologic characteristics and short- and long-term outcomes were compared among the 3 groups.

Results

Patients with hilar type intrahepatic cholangiocarcinoma had more aggressive tumor characteristics (eg, higher frequency of vascular invasion and lymph nodes metastasis) and experienced more extensive resections in comparison with either peripheral intrahepatic cholangiocarcinoma or hilar cholangiocarcinoma patients. The odds of lymphadenectomy and R0 resection rate among patients with hilar type intrahepatic cholangiocarcinoma were comparable with hilar cholangiocarcinoma patients, but higher than peripheral intrahepatic cholangiocarcinoma patients (lymphadenectomy incidence, 85.1% vs 42.5%, P?<?.001; R0 rate, 75.2% vs 88.8%, P?<?.001). After curative surgery, patients with hilar type intrahepatic cholangiocarcinoma experienced a higher rate of technical-related complications compared with peripheral intrahepatic cholangiocarcinoma patients. Of note, hilar type intrahepatic cholangiocarcinoma was associated with worse disease-specific survival and recurrence-free survival after curative resection versus peripheral intrahepatic cholangiocarcinoma (median disease-specific survival, 26.0 vs 54.0 months, P?<?.001; median recurrence-free survival, 13.0 vs 18.0 months, P?=?.021) and hilar cholangiocarcinoma (median disease-specific survival, 26.0 vs 49.0 months, P?=?.003; median recurrence-free survival, 13.0 vs 33.4 months, P?<?.001).

Conclusion

Mass-forming intrahepatic cholangiocarcinoma with hepatic hilus involvement is a more aggressive type of cholangiocarcinoma, which showed distinct clinicopathologic characteristics, worse long-term outcomes after curative resection, in comparison with peripheral intrahepatic cholangiocarcinoma and hilar cholangiocarcinoma.  相似文献   
97.
98.
99.
Obstruction of the hepatic hilum in patients without prior surgery is generally due to hilar adenocarcinoma (Klatskin tumor). However, not all the hilar strictures are malignant. Although uncommon, benign strictures of the proximal bile duct should be taken into consideration in differential diagnosis of Klatskin tumors, since the incidence could reach up to 25% of patients with presumed Klatskin tumor diagnosis. This group of benign proximal bile duct strictures (Klatskin-mimicking lesions) is usually represented by segmental fibrosis and non-specific chronic inflammation. The clinical and imaging features can not differentiate between benign and malignant strictures. Herein, we present a case series of three patients with benign proximal bile duct strictures (representing 4.1% of 73 patients resected with presumptive preoperative diagnosis of Klatskin tumor) and literature review. There are presented the clinical and biochemical features, imaging preoperative workup, surgical treatment and histological analysis of the specimen, along with postoperative outcome. For benign strictures of the hilum limited resections are curative. However, despite new diagnosis tools developed in the last years, patients with hilar obstructions still require unnecessary extensive resections due to impossibility of excluding the malignancy. In all cases of proximal bile duct obstruction presumed malignant, they should be managed accordingly, even with the risk of over-treatment for some benign lesions.  相似文献   
100.
The digestive fistula is one of the most serious complications that might appear following different types of resectional digestive surgery. This condition still carries a considerable morbidity and mortality rate and therefore all surgical and ICU staff pay a great deal of attention and intensify their care to avoid the fatalities. The postoperative digestive fistulas, through their physiopathological and clinical complexity induce the disturbance of the biological equilibrium with vital consequences. The trend of the last decades is the increasing of digestive fistulas incidence with a variable mortality rate after different authors. A therapeutic algorithm is needed. The mortality rate due to digestive fistulas, two decades ago was, around 60%; at the present there is a decrease of the mortality rate, which is around 10%. The explanation is the introduction of the new methods of treatment such as lactic acid lavage aspiration for alkaline fistulas or total parenteral nutrition, continuous enteral nutrition and antiexocrine chemotherapy. A fistula is a communication between two epithelial or endothelial surfaces, lined by granulation tissue. It can be a life-threatening condition.  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