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   5787篇
  免费   421篇
  国内免费   23篇
耳鼻咽喉   47篇
儿科学   240篇
妇产科学   136篇
基础医学   917篇
口腔科学   53篇
临床医学   622篇
内科学   1133篇
皮肤病学   62篇
神经病学   683篇
特种医学   140篇
外科学   589篇
综合类   39篇
预防医学   630篇
眼科学   52篇
药学   462篇
中国医学   26篇
肿瘤学   400篇
  2024年   6篇
  2023年   36篇
  2022年   69篇
  2021年   162篇
  2020年   96篇
  2019年   149篇
  2018年   164篇
  2017年   124篇
  2016年   140篇
  2015年   171篇
  2014年   194篇
  2013年   298篇
  2012年   408篇
  2011年   481篇
  2010年   253篇
  2009年   234篇
  2008年   398篇
  2007年   409篇
  2006年   383篇
  2005年   378篇
  2004年   373篇
  2003年   337篇
  2002年   318篇
  2001年   38篇
  2000年   23篇
  1999年   42篇
  1998年   64篇
  1997年   59篇
  1996年   57篇
  1995年   40篇
  1994年   37篇
  1993年   33篇
  1992年   20篇
  1991年   17篇
  1990年   17篇
  1989年   15篇
  1988年   15篇
  1987年   16篇
  1986年   9篇
  1985年   10篇
  1984年   21篇
  1983年   13篇
  1982年   17篇
  1981年   14篇
  1980年   20篇
  1979年   11篇
  1978年   12篇
  1977年   5篇
  1976年   4篇
  1973年   5篇
排序方式: 共有6231条查询结果,搜索用时 15 毫秒
91.
OBJECTIVE: To evaluate the efficacy of routine follow-up in patients with recurrent uterine cancer. METHODS: In a single institution study, a total of 2637 patients were treated curatively for uterine cancer from 1990 to 2006. A total of 438 patients experienced disease recurrence. Data for detailed analysis were available from 280 of the 438 patients. Prior to the diagnosis of recurrence, all patients had regular follow-up and were investigated through internal examination, vaginal vault cytology and imaging. Overall survival (OS) was the main study endpoint and was calculated from recurrence diagnosis to death or date censored. RESULTS: Clinical and histopathological features as well as patterns of recurrence were similar in symptomatic and asymptomatic patients. Eighty-one patients (28.9%) were diagnosed with asymptomatic recurrence while 199 patients (71.1%) presented with symptomatic recurrence. The overall survival probability at 5 years was 41.0% and 28.9% respectively for asymptomatic and symptomatic patients (log-rank p=0.013). Those patients with stage 1 or 2 tumors of endometrioid type were found to have an overall survival probability at 5 years of 38.0% and 25.7% respectively for asymptomatic and symptomatic recurrence (log-rank p=0.05). The absence of symptoms did not impact on the outcome of patients with stage 3 tumors or tumors of non-endometrioid type. CONCLUSIONS: While patients at low/intermediate risk of recurrence may benefit from intensive follow-up including internal examinations, routine vaginal vault cytology and imaging, high-risk patients might gain more from an alternate follow-up strategy with emphasis on imaging in conjunction with symptom education.  相似文献   
92.
Neonatal and 5-year outcomes after birth at 30-34 weeks of gestation   总被引:1,自引:0,他引:1  
OBJECTIVE: To evaluate the rates of in-hospital death, neonatal complications, and 5-year outcomes of infants born at 30-34 weeks of gestation. METHODS: In nine regions of France, all 2,020 stillbirths and live births at 30, 31, and 32 weeks in 1997 and all 457 births at 33 and 34 weeks in April and October 1997 were recorded. Survivors were evaluated at 5 years of age. RESULTS: Increasing gestational age from 30 to 34 weeks was associated with progressive decreases in in-hospital mortality (from 8.1% to 0.4%) and neonatal complications (respiratory distress syndrome, 43.8% to 2.6%; maternofetal infections, 7.2% to 2.6%; and severe white matter injury, 5.5% to 1.3%). Although infants at 33 and 34 weeks of gestation rarely experienced necrotizing enterocolitis, bronchopulmonary dysplasia, or nosocomial infections, they still required endotracheal ventilation, antibiotics, or parenteral nutrition. At 5 years of age, older gestational age was associated with significant decreases in rates of cerebral palsy (6.3% at 30 weeks and 0.7% at 34 weeks) and mild to severe cognitive impairments (35.3% at 30 weeks and 23.9% at 34 weeks). In singletons, preterm rupture of membranes or preterm labor carried an increased risk of cerebral palsy but not of cognitive impairment. CONCLUSION: Neonates born at 30-34 weeks experienced substantial morbidity and often required admission to neonatal intensive care units. These outcomes suggest that prolonging pregnancies beyond 34 weeks may be desirable whenever possible. Infants born at 30-34 weeks should be carefully monitored to ensure prompt detection and management of neurodevelopmental impairment.  相似文献   
93.
OBJECTIVES: To evaluate the level of information and informed consent for maternal serum screening (MSS) for Down syndrome (DS) in the second trimester of pregnancy and analyse the exercise of autonomy towards the test by the women concerned. METHODS: We studied the population of pregnant women attending obstetric consultations in two French hospitals over a 3-month period. The women were assigned to three groups according to MSS results for DS: women at high risk of having a child with DS (group 1), women at low risk (group 2) and women who did not undergo the test (group 3). A questionnaire was completed before the medical consultation, to assess the quality of consent before amniocentesis for the group at high risk and before the second-trimester ultrasound scan for the other two groups. RESULTS: We analysed 305 questionnaires for 89, 137 and 79 women belonging to groups 1, 2 and 3 respectively. In total, 123 women (40.3% [IC 95%, 35-46%]) were considered to be well informed; 33 (10%, [IC 95%, 8-12%]) had a high level of knowledge, but made choices not consistent with their stated attitude, and 149 (49.7% [IC 95%, 45-56%]) were considered uninformed. Logistic regression analysis showed that maternal consent depended on three independent components: The score attributed to the doctor for information about MSS (t = 4.216, p < 0.001).Whether the patient belonged to group 1 (t = -2.631, p < 0.009).Educational level (< high-school diploma, high-school diploma or at least two years of higher education after high school) (t = 2.324, p < 0.02). The rate of consent increased with educational level and was highest for the women in group 1 and for those whose doctor had a high information score. CONCLUSIONS: Our findings clearly show that women are provided with insufficient information concerning MSS screening for DS in the second trimester of pregnancy for real and valid consent to be obtained.  相似文献   
94.
IntroductionPrevious studies exploring associations of physical inactivity, obesity, and out-of-pocket expenditure (OOPE) mainly used traditional linear regression, and little is known about the effect of both physical inactivity and obesity on OOPE across the percentile distribution. This study aims to assess the effects of physical inactivity and obesity on OOPE in China using a quantile regression approach.MethodsStudy participants included 10,687 respondents aged 45 years and older from the recent wave of the China Health and Retirement Longitudinal Study in 2015. Linear regression and quantile regression models were used to examine the association of physical activity, body weight with annual OOPE.ResultsOverall, the proportion of overweight and obesity was 33.2% and 5.8%, respectively. The proportion of individuals performing high-level, moderate-level, and low-level physical activity was 55.2%, 12.7%, and 32.1%, respectively. The effects of low-level physical activity on annual OOPE were small at the bottom quantiles but more pronounced at higher quantiles. Respondents with low-level activity had an increased annual OOPE of 26.9 USD, 150.3 USD, and 1,534.4 USD, at the 10th, 50th, and 90th percentiles, respectively, compared with those with high-level activity. The effects of overweight and obesity on OOPE were also small at the bottom quantiles but more pronounced at higher quantiles.ConclusionInterventions that improve the lifestyles and unhealthy behaviors among people with obesity and physical inactivity are likely to yield substantial financial gains for the individual and health systems in China.  相似文献   
95.
BackgroundLong‐term follow‐up is necessary to understand the impact of perinatal interventions. Exploring parents'' motives and experiences in consenting to their children taking part in longitudinal studies and understanding what outcomes are important to families may enhance participation and mitigate the loss to follow‐up. As existing evidence is largely based on investigators'' perspectives using Western samples, the present pilot study explored parents'' perspectives in a multicultural New Zealand context.MethodsData were generated using semi‐structured interviews with parents whose children had participated in a longitudinal study after neonatal recruitment. Parents'' experiences of being part of the study were analysed thematically using an inductive approach.ResultsParents (n = 16) were generally happy with the outcomes measured. Additionally, parents were interested in lifelong goals such as the impact of parental diabetes. We identified three themes: (1) Facilitators: Research participation was aided by motives and parent and research characteristics such as wishing to help others and straightforward recruitment; (2) Barriers: A hesitancy to participate was due to technical and clinical research aspects, participation burden and cultural barriers, such as complex wording, time commitment and nonindigenous research and (3) Benefits: Children and parents experienced advantages such as the opportunity for education.ConclusionsParents reported positive experiences and described the unexpected benefit of increasing families'' health knowledge through participation. Improvements for current follow‐up studies were identified. Different ethnicities reported different experiences and perspectives, which warrants ongoing research, particularly with indigenous research participants.Patient or Public ContributionNo active partnership with parents of patients took place.  相似文献   
96.
The SARS-CoV-2 pandemic is currently causing an unprecedented global health emergency since its emergence in December 2019. In December 2021, the FDA granted emergency use authorization to nirmatrelvir, a SARS-CoV-2 main protease inhibitor, for treating infected patients. This peptidomimetic is designed with a nitrile warhead, which forms a covalent bond to the viral protease. Herein, we investigate nirmatrelvir analogs with different warheads and their inhibitory activities. In addition, antiviral activities against human alphacoronavirus 229E was also investigated along with a cell-based assay. We discovered that the hydroxymethylketone and ketobenzothiazole warheads were equipotent to the nitrile warhead, suggesting that these analogs can also be used for treating coronavirus infections.  相似文献   
97.
Highly Pathogenic Avian Influenza Viruses (HPAIVs) arise from low pathogenic precursors following spillover from wild waterfowl into poultry populations. The main virulence determinant of HPAIVs is the presence of a multi-basic cleavage site (MBCS) in the hemagglutinin (HA) glycoprotein. The MBCS allows for HA cleavage and, consequently, activation by ubiquitous proteases, which results in systemic dissemination in terrestrial poultry. Since 1959, 51 independent MBCS acquisition events have been documented, virtually all in HA from the H5 and H7 subtypes. In the present article, data from natural LPAIV to HPAIV conversions and experimental in vitro and in vivo studies were reviewed in order to compile recent advances in understanding HA cleavage efficiency, protease usage, and MBCS acquisition mechanisms. Finally, recent hypotheses that might explain the unique predisposition of the H5 and H7 HA sequences to obtain an MBCS in nature are discussed.  相似文献   
98.
PURPOSE: This study evaluates the effect of heparin-coated balloon-expandable stents on intimal hyperplasia following carotid artery stenting in a baboon model. MATERIALS AND METHODS: Balloon-expandable (Palmaz-Schatz) stents were placed in bilateral common carotid arteries in 26 male baboons (mean weight: 11.3 kg). In each animal, a heparin-coated (HC) carotid stent was placed on one side, whereas the contralateral carotid artery received an uncoated stent that served as a control. The carotid stents were harvested at 30 days (n = 13) and 90 days (n = 13). Arteriography was performed to assess the carotid patency, and intravascular ultrasound was used to determine neointimal and luminal areas. Histological, morphometric analysis, and scanning electron microscopy were performed in the stented carotid arteries. RESULTS: One animal was excluded in each of the 1-month and 3-month groups because of premature death. Ten control (83%) and 11 HC stents (92%) remained patent in the 30-day group. In contrast, 10 control (83%) and 10 HC stents (83%) remained patent in the 90-day group. Morphometric analysis of the 30-day group showed the HC-stented carotid arteries had larger luminal areas (13%, P < 0.05), less neointimal areas (38%, P < 0.05), less neointimal/media ratios (53%, P < 0.05), and equivalent medial areas (NS) when compared with the control group. Morphometric analysis of the 90-day data showed the HC-stented carotid arteries had less neointimal areas (38%, P < 0.05) and less neointimal/media ratios (48%, P < 0.05), whereas the luminal areas and medial areas remained equivalent (NS) when compared with the control group. CONCLUSIONS: Carotid stenting using heparin-coated stents reduces early intimal hyperplasia in a baboon model. This approach may represent a useful strategy for improving luminal patency in endovascular carotid intervention.  相似文献   
99.
100.
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