全文获取类型
收费全文 | 1256篇 |
免费 | 80篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 42篇 |
妇产科学 | 29篇 |
基础医学 | 137篇 |
口腔科学 | 6篇 |
临床医学 | 111篇 |
内科学 | 296篇 |
皮肤病学 | 13篇 |
神经病学 | 149篇 |
特种医学 | 50篇 |
外科学 | 166篇 |
综合类 | 5篇 |
一般理论 | 1篇 |
预防医学 | 112篇 |
眼科学 | 4篇 |
药学 | 40篇 |
中国医学 | 2篇 |
肿瘤学 | 174篇 |
出版年
2023年 | 16篇 |
2022年 | 22篇 |
2021年 | 60篇 |
2020年 | 37篇 |
2019年 | 54篇 |
2018年 | 55篇 |
2017年 | 38篇 |
2016年 | 47篇 |
2015年 | 49篇 |
2014年 | 57篇 |
2013年 | 67篇 |
2012年 | 113篇 |
2011年 | 96篇 |
2010年 | 51篇 |
2009年 | 41篇 |
2008年 | 57篇 |
2007年 | 52篇 |
2006年 | 31篇 |
2005年 | 37篇 |
2004年 | 29篇 |
2003年 | 24篇 |
2002年 | 31篇 |
2001年 | 9篇 |
2000年 | 20篇 |
1999年 | 21篇 |
1998年 | 7篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 13篇 |
1989年 | 20篇 |
1988年 | 14篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 25篇 |
1984年 | 17篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1972年 | 6篇 |
1971年 | 2篇 |
1966年 | 5篇 |
排序方式: 共有1343条查询结果,搜索用时 62 毫秒
51.
Introduction
The influence of vascular risk factors (VRFs) on the rate of cognitive decline in patients with established dementia is unclear. This study aims to examine the association between VRFs and the rate of cognitive decline in patients with Alzheimer's disease (AD).Methods
Data were obtained from patients visiting a memory clinic between 2004 and 2012. VRFs were determined at baseline and included hypertension, hypercholesterolemia, diabetes mellitus, overweight and smoking. Continuous values of blood pressure, total cholesterol, glucose level and body mass index were also obtained. Mini-Mental State Exam (MMSE) scores were obtained at baseline and during follow-up visits. The association between VRFs and the annual change in MMSE scores was analysed with a multivariable linear mixed model adjusted for age, sex and the aforementioned VRFs.Results
From 174 patients (mean age 78.3 years), with a follow-up time up to 5.8 years (mean 1.1 year), in total 447 MMSE scores were obtained. The multivariable analyses showed an association between age as well as systolic blood pressure and a decline in annual rates of change in MMSE scores of −0.05 (95% confidence interval (CI): −0.09 to 0.00) and −0.01 (CI: −0.03 to 0.00), respectively. For all other VRFs, including sex, patients did not show a significant difference.Conclusion
This study did not find an association between preventable vascular risk factors and cognitive decline in patients with AD, except for systolic blood pressure. As the association between systolic blood pressure and decline in MMSE was small, clinical relevance may be limited. 相似文献52.
Sanne de Josselin de Jong Math Candel Dewi Segaar Henricus-Paul Cremers Hein de Vries 《Journal of medical Internet research》2014,16(3)
Background
Preventing smoking initiation among adolescents is crucial to reducing tobacco-caused death and disease. This study focuses on the effectiveness of a Web-based computer-tailored smoking prevention intervention aimed at adolescents.Objective
The intent of the study was to describe the intervention characteristics and to show the effectiveness and results of a randomized controlled trial. We hypothesized that the intervention would prevent smoking initiation among Dutch secondary school students aged 10-20 years and would have the largest smoking prevention effect among the age cohort of 14-16 years, as smoking uptake in that period is highest.Methods
The intervention consisted of a questionnaire and fully automated computer-tailored feedback on intention to start smoking and motivational determinants. A total of 89 secondary schools were recruited via postal mail and randomized into either the computer-tailored intervention condition or the control condition. Participants had to complete a Web-based questionnaire at baseline and at 6-month follow-up. Data on smoking initiation were collected from 897 students from these schools. To identify intervention effects, multilevel logistic regression analyses were conducted using multiple imputation.Results
Smoking initiation among students aged 10-20 years was borderline significantly lower in the experimental condition as compared to the control condition 6 months after baseline (OR 0.25, 95% CI 0.05-1.21, P=.09). Additional analyses of the data for the 14-16 year age group showed a significant effect, with 11.5% (24/209) of the students in the control condition reporting initiation compared to 5.7% (10/176) in the experimental condition (OR 0.22, 95% CI 0.05-1.02, P=.05). No moderation effects were found regarding gender and educational level.Conclusions
The findings of this study suggest that computer-tailored smoking prevention programs are a promising way of preventing smoking initiation among adolescents for at least 6 months, in particular among the age cohort of 14-16 years. Further research is needed to focus on long-term effects.Trial Registration
International Standard Randomized Controlled Trial Number (ISRCTN): 77864351; http://www.controlled-trials.com/ISRCTN77864351 (Archived by WebCite at http://www.webcitation.org/6BSLKSTm5). 相似文献53.
Straetmans Jos M. J. A. A. Stuut Marijn Wagemakers Sanne Hoebers Frank Kaanders Johannes H. A. M. Speel Ernst Jan M. Melchers Willem J. G. Slootweg Piet Kremer Bernd Lacko Martin Takes Robert P. 《European archives of oto-rhino-laryngology》2020,277(6):1753-1761
European Archives of Oto-Rhino-Laryngology - Debate on the extent of treatment of neck metastasis of cancer of unknown primary tumors (CUPs) is still ongoing. In two Dutch tertiary referral... 相似文献
54.
Sanne Jensen Davíð R.M.A. Højgaard Katja A. Hybel Erik Lykke Mortensen Gudmundur Skarphedinsson Karin Melin Tord Ivarsson Judith Becker Nissen Bernhard Weidle Robert Valderhaug Nor Christian Torp Kitty Dahl Scott Compton Per Hove Thomsen 《Journal of child psychology and psychiatry, and allied disciplines》2020,61(9):969-978
55.
Sanne J. H. van Rooij Ryan D. Smith Anaïs F. Stenson Timothy D. Ely Xinyi Yang Nim Tottenham Jennifer S. Stevens Tanja Jovanovic 《Depression and anxiety》2020,37(4):303-312
Most studies investigating the effect of childhood trauma on the brain are retrospective and mainly focus on maltreatment, whereas different types of trauma exposure such as growing up in a violent neighborhood, as well as developmental stage, could have differential effects on brain structure and function. The current magnetic resonance imaging study assessed the effect of trauma exposure broadly and violence exposure more specifically, as well as developmental stage on the fear neurocircuitry in 8‐ to 14‐year‐old children and adolescents (N = 69). We observed reduced hippocampal and increased amygdala volume with increasing levels of trauma exposure. Second, higher levels of violence exposure were associated with increased activation in the amygdala, hippocampus, and ventromedial prefrontal cortex during emotional response inhibition. This association was specifically observed in children younger than 10 years. Finally, increased functional connectivity between the amygdala and brainstem was associated with higher levels of violence exposure. Based on the current findings, it could be hypothesized that trauma exposure during childhood results in structural changes that are associated with later risk for psychiatric disorders. At the same time, it could be postulated that growing up in an unsafe environment leads the brain to functionally adapt to this situation in a way that promotes survival, where the long‐term costs or consequences of these adaptations are largely unknown and an area for future investigations. 相似文献
56.
Sanne C. F. A. Huijberts Robin M. J. M. van Geel Emilie M. J. van Brummelen Frans L. Opdam Serena Marchetti Neeltje Steeghs Saskia Pulleman Bas Thijssen Hilde Rosing Kim Monkhorst Alwin D. R. Huitema Jos H. Beijnen Ren Bernards Jan H. M. Schellens 《Cancer chemotherapy and pharmacology》2020,85(5):917-930
KRAS oncogene mutations cause sustained signaling through the MAPK pathway. Concurrent inhibition of MEK, EGFR, and HER2 resulted in complete inhibition of tumor growth in KRAS-mutant (KRASm) and PIK3CA wild-type tumors, in vitro and in vivo. In this phase I study, patients with advanced KRASm and PIK3CA wild-type colorectal cancer (CRC), non-small cell lung cancer (NSCLC), and pancreatic cancer, were treated with combined lapatinib and trametinib to assess the recommended phase 2 regimen (RP2R). Patients received escalating doses of continuous or intermittent once daily (QD) orally administered lapatinib and trametinib, starting at 750 mg and 1 mg continuously, respectively. Thirty-four patients (16 CRC, 15 NSCLC, three pancreatic cancers) were enrolled across six dose levels and eight patients experienced dose-limiting toxicities, including grade 3 diarrhea (n = 2), rash (n = 2), nausea (n = 1), multiple grade 2 toxicities (n = 1), and aspartate aminotransferase elevation (n = 1), resulting in the inability to receive 75% of planned doses (n = 2) or treatment delay (n = 2). The RP2R with continuous dosing was 750 mg lapatinib QD plus 1 mg trametinib QD and with intermittent dosing 750 mg lapatinib QD and trametinib 1.5 mg QD 5 days on/2 days off. Regression of target lesions was seen in 6 of the 24 patients evaluable for response, with one confirmed partial response in NSCLC. Pharmacokinetic results were as expected. Lapatinib and trametinib could be combined in an intermittent dosing schedule in patients with manageable toxicity. Preliminary signs of anti-tumor activity in NSCLC have been observed and pharmacodynamic target engagement was demonstrated. 相似文献
57.
58.
Alexander P. J. Vlaar Endry H. T. Lim Sanne de Bruin Simon Rückinger Korinna Pilz Matthijs C. Brouwer RenFeng Guo Leo
M. A. Heunks Matthias H. Busch Pieter van Paassen Niels
C. Riedemann Diederik van de Beek 《CTS Clinical and Translational Science》2022,15(4):854
Recently, we reported the phase II portion of the adaptive phase II/III PANAMO trial exploring potential benefit and safety of selectively blocking C5a with the monoclonal antibody vilobelimab (IFX‐1) in patients with severe coronavirus disease 2019 (COVID‐19). The potent anaphylatoxin C5a attracts neutrophils and monocytes to the infection site, causes tissue damage by oxidative radical formation and enzyme releases, and leads to activation of the coagulation system. Results demonstrated that C5a inhibition with vilobelimab was safe and secondary outcomes appeared in favor of vilobelimab. We now report the pharmacokinetic/pharmacodynamic (PK/PD) analysis of the phase II study. Between March 31 and April 24, 2020, 30 patients with severe COVID‐19 pneumonia confirmed by real‐time polymerase chain reaction were randomly assigned 1:1 to receive vilobelimab plus best supportive care or best supportive care only. Samples for measurement of vilobelimab, C3a and C5a blood concentrations were taken. Vilobelimab predose (trough) drug concentrations in plasma ranged from 84,846 to 248,592 ng/ml (571 to 1674 nM) with a geometric mean of 151,702 ng/ml (1022 nM) on day 2 and from 80,060 to 200,746 ng/ml (539 to 1352 nM) with a geometric mean of 139,503 ng/ml (939 nM) on day 8. After the first vilobelimab infusion, C5a concentrations were suppressed in the vilobelimab group (median 39.70 ng/ml 4.8 nM, IQR 33.20–45.55) as compared to the control group (median 158.53 ng/ml 19.1 nM, IQR 60.03–200.89, p = 0.0006). The suppression was maintained on day 8 (p = 0.001). The current PK/PD analysis shows that vilobelimab efficiently inhibits C5a in patients with severe COVID‐19. Study Highlights
- WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?
- WHAT QUESTION DID THIS STUDY ADDRESS?
- WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?
- HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?
59.
Grith Møller Christian Ritz Louise Kjølbæk Stine Vuholm Sanne Kellebjerg Korndal Thomas Meinert Larsen Oluf Pedersen Wim Saris Arne Astrup Lotte Lauritzen Mette Kristensen Mads Vendelbo Lind 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2021,31(2):518-527
Background and aimsBody mass index (BMI) and waist circumference (WC) are commonly used markers of cardiometabolic risk. However, sagittal abdominal diameter (SAD) has been proposed as a possibly more sensitive marker of intra-abdominal obesity. We investigated differences in how SAD, WC, and BMI were correlated with cardiometabolic risk markers.Methods and resultsThis cross-sectional study investigated anthropometric and metabolic baseline measurements of individuals from six trials. Multiple linear regression and (partial) correlation coefficients were used to investigate associations between SAD, WC, and BMI and cardiometabolic risk markers, including components of the metabolic syndrome as well as insulin resistance, blood lipids, and lowgrade inflammation.In total 1516 mostly overweight or obese individuals were included in the study. SAD was significantly more correlated with TG than WC for all studies, and overall increase in correlation was 0.05 (95% CI (0.02; 0.08). SAD was significantly more correlated with the markers TG and DBP 0.11 (95% CI (0.08, 0.14)) and 0.04 (95% CI (0.006, 0.07), respectively compared to BMI across all or most studies.ConclusionThis study showed that no single anthropometric indicator was consistently more strongly correlated across all markers of cardiometabolic risk. However, SAD was significantly more strongly correlated with TG than WC and significantly more strongly correlated with DBP and TG than BMI. 相似文献