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   3602篇
  免费   275篇
  国内免费   30篇
耳鼻咽喉   25篇
儿科学   158篇
妇产科学   79篇
基础医学   564篇
口腔科学   31篇
临床医学   264篇
内科学   857篇
皮肤病学   132篇
神经病学   536篇
特种医学   92篇
外科学   225篇
综合类   1篇
一般理论   1篇
预防医学   224篇
眼科学   33篇
药学   256篇
中国医学   9篇
肿瘤学   420篇
  2024年   8篇
  2023年   41篇
  2022年   93篇
  2021年   131篇
  2020年   98篇
  2019年   117篇
  2018年   123篇
  2017年   102篇
  2016年   124篇
  2015年   153篇
  2014年   168篇
  2013年   211篇
  2012年   285篇
  2011年   294篇
  2010年   180篇
  2009年   141篇
  2008年   253篇
  2007年   247篇
  2006年   249篇
  2005年   222篇
  2004年   180篇
  2003年   171篇
  2002年   136篇
  2001年   17篇
  2000年   13篇
  1999年   20篇
  1998年   23篇
  1997年   18篇
  1996年   13篇
  1995年   7篇
  1994年   7篇
  1993年   11篇
  1992年   3篇
  1991年   4篇
  1990年   5篇
  1989年   3篇
  1988年   5篇
  1987年   2篇
  1986年   4篇
  1985年   2篇
  1984年   5篇
  1983年   4篇
  1982年   3篇
  1976年   1篇
  1972年   1篇
  1971年   2篇
  1970年   1篇
  1969年   2篇
  1968年   1篇
  1966年   1篇
排序方式: 共有3907条查询结果,搜索用时 15 毫秒
1.
2.

Background  

We present our experience of therapeutic vaccination using dendritic cells (DC) pulsed with autologous tumor antigens in patients with advanced melanoma.  相似文献   
3.
A sound that we hear in a natural setting allows us to identify the sound source and localize it in space. The two aspects can be disrupted independently as shown in a study of 15 patients with focal right-hemispheric lesions. Four patients were normal in sound recognition but severely impaired in sound localization, whereas three other patients had difficulties in recognizing sounds but localized them well. The lesions involved the inferior parietal and frontal cortices, and the superior temporal gyrus in patients with selective sound localization deficit; and the temporal pole and anterior part of the fusiform, inferior and middle temporal gyri in patients with selective recognition deficit. These results suggest separate cortical processing pathways for auditory recognition and localization. Electronic Publication  相似文献   
4.
To study the presence of metals in body fluids and tissues after implantation of metallic biomaterials and possible related diseases, a new approach in Atomic Absorption Spectrophotometry (AAS) was developed. This technique was compared to three traditional methods: mineralisation with acid digestion (method A) also known as "wet method", dry ashing (with or without oxygen) (method B); classic Kjeldaal (method C). The new approach (method D) modifies the mineralisation phase and the instrument operating instructions. Al, Na, Cr, K, Ni, Co, Ti, Fe, Hg, Pb, V, Sb and Cu levels were tested with the four methods on bone, muscle, cartilage, skin, brain, lymph nodes, blood, urine, and hair. Test results were checked by the addition method. Results demonstrated a significantly higher percentage of Al, Cr, Ni, Ti and Hg recovery with the new approach. The advantages of method D are no residue, no redox reaction, insignificant loss of analytes and enhanced sensitivity (at ppb level vs ppm of the other methods). This approach should be considered especially when testing heavy metals and complex matrices. Its disadvantages are that it is more time consuming and requires the presence of an operator.  相似文献   
5.
6.
7.
Previous studies have revealed that decoding of facial-expressions starts very early in the brain ( approximately 180 ms post-stimulus) and might be processed separately from the basic stage of face perception. In order to explore brain potentials (ERPs) related to decoding of facial-expressions and the effect of emotional valence of the stimulus, we analyzed 18 normal subjects. Faces with five basic emotional expressions (fear, anger, surprise, happiness, sadness) and neutral stimulus were presented in random order. The results demonstrated that an emotional face elicited a negative peak at approximately 230 ms (N230), distributed mainly over the posterior site for each emotion. The electrophysiological activity observed may represent specific cognitive processing underlying the decoding of emotional facial-expressions. Nevertheless, differences in peak amplitude were observed for high-arousal negative expressions compared with positive (happiness) and low-arousal expressions (sadness). N230 amplitude increased in response to anger, fear and surprise, suggesting that subjects' ERP variations are affected by experienced emotional intensity, related to arousal and unpleasant value of the stimulus.  相似文献   
8.
Hazelnuts commonly elicit allergic reactions starting from childhood and adolescence, with a rare resolution over time. The definite diagnosis of a hazelnut allergy relies on an oral food challenge. The role of component resolved diagnostics in reducing the need for oral food challenges in the diagnosis of hazelnut allergies is still debated. Therefore, three electronic databases were systematically searched for studies on the diagnostic accuracy of specific-IgE (sIgE) on hazelnut proteins for identifying children with a hazelnut allergy. Studies regarding IgE testing on at least one hazelnut allergen component in children whose final diagnosis was determined by oral food challenges or a suggestive history of serious symptoms due to a hazelnut allergy were included. Study quality was assessed by the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Eight studies enrolling 757 children, were identified. Overall, sensitivity, specificity, area under the curve and diagnostic odd ratio of Cor a 1 sIgE were lower than those of Cor a 9 and Cor a 14 sIge. When the test results were positive, the post-test probability of a hazelnut allergy was 34% for Cor a 1 sIgE, 60% for Cor a9 sIgE and 73% for Cor a 14 sIgE. When the test results were negative, the post-test probability of a hazelnut allergy was 55% for Cor a 1 sIgE, 16% for Cor a9 sIgE and 14% for Cor a 14 sIgE. Measurement of IgE levels to Cor a 9 and Cor a 14 might have the potential to improve specificity in detecting clinically tolerant children among hazelnut-sensitized ones, reducing the need to perform oral food challenges.  相似文献   
9.
Geometric cis, trans isomers, derivatives of 2-substituted-1,3-dioxanes were designed and studied as antimuscarinic agents. The synthesized compounds were evaluated as perchlorides and methiodides by functional tests with rabbit vas deferens (putative M1), guinea-pig heart (M2) and guinea-pig ileum (M3). The effect of the replacement of a trimethylammonium group with a dimethysulfonium in the two rings was also evaluated. Pharmacological results indicate that the 1,3-dioxane nucleus shows the highest stereoselective values on the studied receptors.  相似文献   
10.
Simple SummaryGlioblastoma is an aggressive brain tumor with a dismal prognosis. In a minority of cases, it presents with multiple lesions already at the time of diagnosis, affecting patients’ survival and treatment. Our retrospective study aims to increase the current understanding and define a treatment for this sub-entity, to improve patient survival. Chemoradiotherapy is a also safe and efficacy treatment in patients with multiple lesions. Survival advantages from extensive resection remain unclear.AbstractGlioblastomas with multiple foci at presentation (mGBMs) account for 2–35% of all GBMs. mGBMs have limited existing data and no standardized treatment. This study aims to determine their incidence, demographic and clinical features, outcome, and prognostic factors in terms of overall survival. We performed a monocentric retrospective study, reviewing patients treated at the Istituto Oncologico Veneto. Inclusion criteria were: new diagnosis of GBM and presence of multiple lesions on pre-treatment MRI. ECOG PS was used to evaluate clinical condition, RANO criteria for radiological assessment, and CTCAE v5.0 for treatment-related adverse events. The incidence of newly diagnosed mGBM was 7.2% and the study population consisted of 98 patients. Median age was 63 years, M:F ratio of 1.8:1, and a surgical approach was undertaken in 73 patients (mostly partial resection). MGMT was methylated in 47.5%, and 82 patients received active oncological treatment (65.9% radiotherapy plus temozolomide (RT + TMZ)). The disease control rate with RT + TMZ was 63%. Median OS of the entire study population was 10.2 months (95% CI 6.6–13.8), and median PFS was 4.2 months (95% CI 3.2–5.2). The ECOG PS, the extent of resection, and the RT + TMZ were significant prognostic factors in the univariate analysis for OS, but only the RT + TMZ was a significant independent OS predictor in the multivariate analysis (HR = 3.1, 95% IC 1.3–7.7, p = 0.014). The incidence of mGBM is not rare. RT + TMZ is confirmed to be an independent prognostic factor for survival and a safe and effective treatment. When feasible, RT + TMZ should be considered as a possible first-line treatment. The role of the extent of resection is still unclear.  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