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   11351篇
  免费   774篇
  国内免费   42篇
耳鼻咽喉   77篇
儿科学   298篇
妇产科学   246篇
基础医学   1926篇
口腔科学   96篇
临床医学   1039篇
内科学   2525篇
皮肤病学   186篇
神经病学   1270篇
特种医学   294篇
外科学   1129篇
综合类   50篇
一般理论   1篇
预防医学   885篇
眼科学   214篇
药学   751篇
中国医学   20篇
肿瘤学   1160篇
  2024年   10篇
  2023年   100篇
  2022年   158篇
  2021年   330篇
  2020年   213篇
  2019年   308篇
  2018年   400篇
  2017年   246篇
  2016年   245篇
  2015年   312篇
  2014年   448篇
  2013年   572篇
  2012年   977篇
  2011年   967篇
  2010年   514篇
  2009年   542篇
  2008年   831篇
  2007年   853篇
  2006年   748篇
  2005年   753篇
  2004年   665篇
  2003年   650篇
  2002年   624篇
  2001年   60篇
  2000年   53篇
  1999年   62篇
  1998年   94篇
  1997年   94篇
  1996年   69篇
  1995年   51篇
  1994年   46篇
  1993年   39篇
  1992年   20篇
  1991年   14篇
  1990年   11篇
  1989年   8篇
  1988年   9篇
  1987年   7篇
  1986年   9篇
  1985年   3篇
  1984年   4篇
  1983年   4篇
  1982年   5篇
  1981年   3篇
  1979年   3篇
  1978年   3篇
  1968年   3篇
  1964年   3篇
  1947年   2篇
  1942年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Raul Zamora-Ros  Valerie Cayssials  Mazda Jenab  Joseph A. Rothwell  Veronika Fedirko  Krasimira Aleksandrova  Anne Tjønneland  Cecilie Kyrø  Kim Overvad  Marie-Christine Boutron-Ruault  Franck Carbonnel  Yahya Mahamat-Saleh  Rudolf Kaaks  Tilman Kühn  Heiner Boeing  Antonia Trichopoulou  Elissavet Valanou  Effie Vasilopoulou  Giovanna Masala  Valeria Pala  Salvatore Panico  Rosario Tumino  Fulvio Ricceri  Elisabete Weiderpass  Torkjel M. Sandanger  Cristina Lasheras  Antonio Agudo  Maria-Jose Sánchez  Pilar Amiano  Carmen Navarro  Eva Ardanaz  Emily Sonestedt  Bodil Ohlsson  Lena Maria Nilsson  Martin Rutegård  Bas Bueno-de-Mesquita  Kay-Thee Khaw  Nicholas J. Wareham  Kathryn Bradbury  Heinz Freisling  Isabelle Romieu  Amanda J. Cross  Paolo Vineis  Augustin Scalbert 《European journal of epidemiology》2018,33(11):1063-1075
Polyphenols may play a chemopreventive role in colorectal cancer (CRC); however, epidemiological evidence supporting a role for intake of individual polyphenol classes, other than flavonoids is insufficient. We evaluated the association between dietary intakes of total and individual classes and subclasses of polyphenols and CRC risk and its main subsites, colon and rectum, within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The cohort included 476,160 men and women from 10 European countries. During a mean follow-up of 14 years, there were 5991 incident CRC cases, of which 3897 were in the colon and 2094 were in the rectum. Polyphenol intake was estimated using validated centre/country specific dietary questionnaires and the Phenol-Explorer database. In multivariable-adjusted Cox regression models, a doubling in total dietary polyphenol intake was not associated with CRC risk in women (HRlog2?=?1.06, 95% CI 0.99–1.14) or in men (HRlog2?=?0.97, 95% CI 0.90–1.05), respectively. Phenolic acid intake, highly correlated with coffee consumption, was inversely associated with colon cancer in men (HRlog2?=?0.91, 95% CI 0.85–0.97) and positively associated with rectal cancer in women (HRlog2?=?1.10, 95% CI 1.02–1.19); although associations did not exceed the Bonferroni threshold for significance. Intake of other polyphenol classes was not related to colorectal, colon or rectal cancer risks. Our study suggests a possible inverse association between phenolic acid intake and colon cancer risk in men and positive with rectal cancer risk in women.  相似文献   
92.
BackgroundWest Nile virus (WNV) and Usutu virus (USUV), two closely related flaviviruses, mainly follow an enzootic cycle involving mosquitoes and birds, but also infect humans and other mammals. Since 2010, their epidemiological situation may have shifted from irregular epidemics to endemicity in several European regions; this requires confirmation, as it could have implications for risk assessment and surveillance strategies.AimTo explore the seroprevalence in animals and humans and potential endemicity of WNV and USUV in Southern France, given a long history of WNV outbreaks and the only severe human USUV case in France in this region.MethodsWe evaluated the prevalence of WNV and USUV in a repeated cross-sectional study by serological and molecular analyses of human, dog, horse, bird and mosquito samples in the Camargue area, including the city of Montpellier, between 2016 and 2020.ResultsWe observed the active transmission of both viruses and higher USUV prevalence in humans, dogs, birds and mosquitoes, while WNV prevalence was higher in horses. In 500 human samples, 15 were positive for USUV and 6 for WNV. Genetic data showed that the same lineages, WNV lineage 1a and USUV lineage Africa 3, were found in mosquitoes in 2015, 2018 and 2020.ConclusionThese findings support existing literature suggesting endemisation in the study region and contribute to a better understanding of USUV and WNV circulation in Southern France. Our study underlines the importance of a One Health approach for the surveillance of these viruses.  相似文献   
93.
This study investigates the relation between early life conditions and adult obesity in France, using a rich data set collected through the 2003 nationally representative Life History Survey. No salient factor emerged in men, while in women, after controlling for current socio-demographic characteristics, a relation was found between obesity and the following factors: father's occupation (OR = 3.2 for women whose father was a clerical worker, versus those whose father was in a higher-level occupation); experience of economic hardship in childhood (OR = 2.0), and; high parity (OR = 2.1 for parities of more than 3 versus parity of 1). Neither early family history nor mother's working status surfaced as significant factors. Those findings highlight a definite gender pattern, with a strong association between early disadvantage and obesity in women, but not in men. Potential mechanisms are discussed, particularly the “habitus”, the “thrifty phenotype” and the “feast–famine” hypotheses, and possible interactions with childbearing and motherhood. An integration of social and biological perspectives is needed to reach a better understanding of the processes involved, and to achieve progress in primary and secondary prevention.  相似文献   
94.
IntroductionTo effectively foster patient‐centeredness (PC), it is crucial to measure its implementation. So far, there is no German measure to assess PC comprehensively. The aim of this study is to develop and select items for the Experienced Patient‐Centeredness (EPAT) Questionnaire, a patient‐reported experience measure (PREM). The EPAT intends to assess PC from the perspective of adult patients treated for different chronic diseases in inpatient and outpatient settings in Germany. Furthermore, we aim at providing a best‐practice example for developing PREMs from qualitative data.MethodsThe development process comprised a three‐phase mixed‐method design: (1) preparation, (2) item generation and (3) item selection and testing of content validity. We generated items using qualitative content analysis based on information from focus groups, key informant interviews and literature search. We selected items using relevance rating and cognitive interviews. Participants were patients from four chronic disease groups (cancer, cardiovascular disease, mental disorder, musculoskeletal disorder) and healthcare experts (e.g., clinicians, researchers, patient representatives).ResultsWe conducted six focus groups with a total of 40 patients, key informant interviews with 10 experts and identified 48 PREMs from international literature. After team discussion, we reached a preliminary pool of 152 items. We conducted a relevance rating with 32 experts and 34 cognitive interviews with 21 patients. We selected 125 items assessing 16 dimensions of PC and showed high relevance and comprehensibility.ConclusionsThe EPAT questionnaire is currently undergoing psychometric testing. The transparent step‐by‐step report provides a best practice example that other researchers may consider for developing PREMs. Integrating literature and experts with a strong focus on patient feedback ensured good content validity. The EPAT questionnaire will be helpful in assessing PC in routine clinical practice in inpatient and outpatient settings for research and quality improvement.Patient or Public ContributionPatients were not involved as active members of the research team. While developing the funding proposal, we informally reached out to several patient organizations who all gave us positive feedback on the study aims, thereby confirming their relevance. Those patient organizations endorsed the funding proposal with formal letters of support and supported recruitment by disseminating advertisements for study participation.  相似文献   
95.
Background Sentinel lymph node (SLN) mapping with radioisotope and blue dye is rapidly becoming the standard of care for breast cancer. The optimal location for injection of radioisotope and blue dye is still being investigated. The goal of this study was to determine whether blue dye injection into the subareolar (SA) location localized the same sentinel nodes as the peritumoral (PT) location for patients with breast cancer. Methods Three hundred thirty-two patients with biopsy-proven operable breast cancer or ductal carcinoma in situ at two institutions underwent SLN mapping. Eighty-three patients had PT injection of blue dye (group 1), and 249 patients had SA injection of blue dye (group 2). All patients underwent PT injection of99mTc-labeled sulfur colloid. Results The two groups were similar in age, previous biopsy type, and tumor size, location, and histology. The mean number of SLNs identified was 2.4 (range, 0–9) in group 1 and 2.5 (range, 0–11) in group 2. The SLN identification rate was 95% for group 1 and 97% for group 2. The isotope success rate was 94% for both groups. The blue dye success rate was 84% for group 1 and 90% for group 2. The isotope/blue dye concordance rate was 87% for group 1 and 90% for group 2. At a median follow-up of 28 months (range, 14 to 40), there were no axillary recurrences in any of the 332 patients. Conclusions These data suggest that delivery of mapping reagents in the SA and PT locations identifies similar lymph nodes. Because of simplicity and the similarity in node identification between SA and PT injection, further investigation of the SA site for delivery of SLN mapping reagents for breast cancer is warranted. Presented at the 54th Annual Cancer Symposium, Society of Surgical Oncology. Washington, DC, March 15–18, 2001.  相似文献   
96.
BACKGROUND: Breast-conservation therapy (BCT), including wide local excision and postoperative irradiation, is considered standard treatment for early-stage invasive ductal carcinoma (IDC). The use of BCT in patients with invasive lobular carcinoma (ILC) has been questioned because of concerns regarding ipsilateral breast recurrence and risk of bilateral breast cancer. We evaluated our institutional experience with BCT and compared treatment outcomes for ILC with those for IDC. METHODS: A review of our BCT database revealed 84 patients with ILC and 1,126 with IDC with stage I or II disease treated with BCT and radiation between 1976 and 1999. We evaluated local-regional recurrence, disease-specific survival, and contralateral breast cancer rates in both groups. RESULTS: The 5- and 10-year local-regional recurrence rates for the ILC group were 1% and 7%, respectively, and 4% and 9%, respectively, for the IDC group (P = .70). There were no significant differences in the 5- and 10-year disease-specific survival rates between the groups. Contralateral breast cancer occurred in 11.3% of patients with IDC and 11.9% of patients with ILC. CONCLUSIONS: BCT achieves similar local-regional control and survival outcomes in selected patients with ILC or IDC. Breast-conservation therapy is an appropriate treatment strategy for patients with early-stage invasive lobular carcinoma.  相似文献   
97.
98.
99.
100.
Dyskeratosis congenita and its variants have overlapping phenotypes with many disorders including Coats plus, and their underlying pathology is thought to be one of defective telomere maintenance. Recently, biallelic CTC1 mutations have been described in patients with syndromes overlapping Coats plus. CTC1, STN1 and TEN1 are part of the telomere-capping complex involved in maintaining telomeric structural integrity. Based on phenotypic overlap we screened 73 genetically uncharacterized patients with dyskeratosis congenita and related bone marrow failure syndromes for mutations in this complex. Biallelic CTC1 mutations were identified in 6 patients but none in either STN1 or TEN1. We have expanded the phenotypic spectrum associated with CTC1 mutations and report that intracranial and retinal abnormalities are not a defining feature, as well as showing that the effect of these mutations on telomere length is variable. The study also demonstrates the lack of disease-causing mutations in other components of the telomere-capping complex.  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