全文获取类型
收费全文 | 969篇 |
免费 | 52篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 40篇 |
妇产科学 | 16篇 |
基础医学 | 109篇 |
口腔科学 | 5篇 |
临床医学 | 90篇 |
内科学 | 173篇 |
皮肤病学 | 21篇 |
神经病学 | 109篇 |
特种医学 | 25篇 |
外科学 | 154篇 |
预防医学 | 70篇 |
眼科学 | 48篇 |
药学 | 78篇 |
中国医学 | 1篇 |
肿瘤学 | 71篇 |
出版年
2024年 | 1篇 |
2023年 | 15篇 |
2022年 | 22篇 |
2021年 | 38篇 |
2020年 | 23篇 |
2019年 | 35篇 |
2018年 | 34篇 |
2017年 | 16篇 |
2016年 | 23篇 |
2015年 | 43篇 |
2014年 | 44篇 |
2013年 | 56篇 |
2012年 | 87篇 |
2011年 | 92篇 |
2010年 | 48篇 |
2009年 | 49篇 |
2008年 | 61篇 |
2007年 | 55篇 |
2006年 | 51篇 |
2005年 | 59篇 |
2004年 | 48篇 |
2003年 | 48篇 |
2002年 | 37篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 3篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1974年 | 2篇 |
排序方式: 共有1032条查询结果,搜索用时 0 毫秒
1.
Felix Eckstein Axel Weusten Corina Schmidt Ulrich Wehr Rüdiger Wanke Walter Rambeck Eckhard Wolf Subburaman Mohan 《Journal of bone and mineral research》2004,19(5):802-810
In this study we examined the effect of systemic overexpression of GH on bone in transgenic mice longitudinally in vivo over a period of 9 months. We observed substantially increased BMC in GH transgenic mice and a significant reduction in serum osteocalcin. GH effects on bone were strongly dependent on gender and developmental stage. INTRODUCTION: State-of-the-art bone marker and microimaging technology was applied in this longitudinal study to examine bone metabolism, BMC, bone density, and cortical bone structure over the life span of growth hormone (GH) transgenic (tg) mice. MATERIALS AND METHODS: Thirty-eight mice from four genetic groups (male, female, tg, and controls) were examined with DXA, and their femur and tibia were examined with peripheral QCT (pQCT). Osteocalcin (formation) and collagen cross-links (resorption) from serum and urine were also measured at postnatal weeks 3, 6, 9, 12, 18, 26, and 38. RESULTS: GH tg mice displayed a significant increase in body weight (up to 50%) and BMC (up to 90%), but serum osteocalcin was significantly reduced compared with controls. GH tg females (but not males) displayed increased trabecular density over controls up to week 12. In contrast, male (but not female) GH tg mice displayed a higher cortical cross-sectional area than controls. Cortical density was significantly lower in both male and female GH tg mice compared with control mice. CONCLUSIONS: The increase in BMC in GH tg mice is associated with reduced serum osteocalcin levels, indicating that bone turnover may be lower than in the control mice. On a structural level, bone responds to GH excess in a gender-specific manner, with alterations varying substantially between different developmental stages. 相似文献
2.
Monica Ruotolo Mario Gagliardi Carolina Ciacci Fabiana Zingone Corina de Santis Ciacci Antonella Santonicola Giovanna DArcangelo Monica Siniscalchi 《Nutrients》2021,13(6)
Background: Coronavirus disease 2019 (COVID-19) causes not only severe illness but also detrimental effects associated with the lockdown measures. The present study aimed to evaluate reported lifestyle changes in a cohort of adults in Italy, including physical exercise, food choices, and psychological wellbeing, after two months of lockdown. Methods: A web survey on social media (Facebook and LinkedIn) of 32 multiple-choice questions aiming to evaluate the impact of the national COVID-19 lockdown in a sample of Italian adults. Results: We received 1378 complete responses (women 68.3%, mean age 39.5 ± 12.5 years). The percentage of participants reporting regular exercise decreased during lockdown (52 vs. 56.5%). The vast majority of people continued to consume the three traditional meals per day, but the consumption of meat, fish, and eggs significantly decreased. Women reported more frequent anxiety, sadness, fear, and feelings of insecurity than men. The factors predicting the worst outcome during the lockdown were being a woman, low education and income, gastrointestinal diseases. Conclusion: The lockdown has had a limited impact on food choices and physical exercise in Italian adults of our series, since most of them made an effort to improve their lifestyle. However, women with gastrointestinal diseases reported more frequent negative feelings and poor adaptation to the lockdown. 相似文献
3.
Charles Varnell Jr Lyndsay A. Harshman Laurie Smith Chunyan Liu Shiran Chen Samhar Al-Akash Gina-Marie Barletta Craig Belsha Paul Brakeman Abanti Chaudhuri Paul Fadakar Rouba Garro Caroline Gluck Jens Goebel David Kershaw Debora Matossian Corina Nailescu Hiren P. Patel Cozumel Pruette Saritha Ranabothu Nancy Rodig Jodi Smith Judith Sebestyen VanSickle Patricia Weng Lara Danziger-Isakov David K. Hooper Michael Seifert 《American journal of transplantation》2021,21(8):2740-2748
There are limited data on the impact of COVID-19 in children with a kidney transplant (KT). We conducted a prospective cohort study through the Improving Renal Outcomes Collaborative (IROC) to collect clinical outcome data about COVID-19 in pediatric KT patients. Twenty-two IROC centers that care for 2732 patients submitted testing and outcomes data for 281 patients tested for SARS-CoV-2 by PCR. Testing indications included symptoms and/or potential exposures to COVID-19 (N = 134, 47.7%) and/or testing per hospital policy (N = 154, 54.8%). Overall, 24 (8.5%) patients tested positive, of which 15 (63%) were symptomatic. Of the COVID-19-positive patients, 16 were managed as outpatients, six received non-ICU inpatient care and two were admitted to the ICU. There were no episodes of respiratory failure, allograft loss, or death associated with COVID-19. To estimate incidence, subanalysis was performed for 13 centers that care for 1686 patients that submitted all negative and positive COVID-19 results. Of the 229 tested patients at these 13 centers, 10 (5 asymptomatic) patients tested positive, yielding an overall incidence of 0.6% and an incidence among tested patients of 4.4%. Pediatric KT patients in the United States had a low estimated incidence of COVID-19 disease and excellent short-term outcomes. 相似文献
4.
5.
Tyler Ray Daniel Fleming Daniel Le Mallory Faherty Carolyn Killelea Jeffrey Bytomski Tracy Ray Larry Lemak Corina Martinez Michael F. Bergeron Timothy Sell 《International Journal of Sports Physical Therapy》2022,17(5):816
BackgroundRecent evidence has demonstrated that athletes are at greater risk for a lower extremity injury following a return-to-sport (RTS) after sport-related concussion (SRC). The reason for this is not completely clear, but it has been hypothesized that persistent deficits in neurocognitive factors may be a contributing factor.Hypothesis/PurposeThis study assessed simple reaction time, processing speed, attention, and concentration in a group of athletes, post-concussion upon clearance for RTS for potential deficits that may result in slower reaction time, processing speed, attention, and concentration. The researchers hypothesized that the concussion group would demonstrate worse scores on both assessments compared to a sex-, age-, and sport-matched cohort.Study DesignCase-controlled studyMethodsTwelve participants who had suffered a SRC and eight healthy individuals who were matched to the concussed group by age, sex, and sport were evaluated. Those with a concussion had been cleared for RTS by a licensed healthcare provider. Each participant underwent neurocognitive tests that included a simple reaction time test (SRT) and the King-Devick Test (K-D). Independent t-tests were performed to compare the groups with significance set a priori at p<0.05.ResultsThere was a significant difference (p =0.024) between groups for SRT with the concussed group demonstrating a better SRT than the control group. There were no significant differences (p =0.939) between the groups for the K-D.ConclusionWith no significant differences between groups in the K-D assessment and, surprisingly, the concussed group having a better SRT compared to the healthy group, our hypothesis was not supported.Clinical RelevanceThese specific measures, compounded with extensive post-concussion time lapse until RTS clearance, may have limited capacity in revealing potential persistent deficits in relevant neurocognitive characteristics.Level of EvidenceLevel of Evidence 3 相似文献
6.
Joaquín Portilla óscar Moreno-Pérez Carmen Serna-Candel Corina Escoín Rocio Alfayate Sergio Reus Esperanza Merino Vicente Boix Livia Giner José Sánchez-Payá Antonio Picó 《Journal of the International AIDS Society》2014,17(1)
Introduction
Vitamin D insufficiency (VDI) has been associated with increased cardiovascular risk in the non-HIV population. This study evaluates the relationship among serum 25-hydroxyvitamin D [25(OH)D] levels, cardiovascular risk factors, adipokines, antiviral therapy (ART) and subclinical atherosclerosis in HIV-infected males.Methods
A cross-sectional study in ambulatory care was made in non-diabetic patients living with HIV. VDI was defined as 25(OH)D serum levels <75 nmol/L. Fasting lipids, glucose, inflammatory markers (tumour necrosis factor-α, interleukin-6, high-sensitivity C-reactive protein) and endothelial markers (plasminogen activator inhibitor-1, or PAI-I) were measured. The common carotid artery intima-media thickness (C-IMT) was determined. A multivariate logistic regression analysis was made to identify factors associated with the presence of VDI, while multivariate linear regression analysis was used to identify factors associated with common C-IMT.Results
Eighty-nine patients were included (age 42±8 years), 18.9% were in CDC (US Centers for Disease Control and Prevention) stage C and 75 were on ART. VDI was associated with ART exposure, sedentary lifestyle, higher triglycerides levels and PAI-I. In univariate analysis, VDI was associated with greater common C-IMT. The multivariate linear regression model, adjusted by confounding factors, revealed an independent association between common C-IMT and patient age, time of exposure to protease inhibitors (PIs) and impaired fasting glucose (IFG). In contrast, there were no independent associations between common C-IMT and VDI or inflammatory and endothelial markers.Conclusions
VDI was not independently associated with subclinical atherosclerosis in non-diabetic males living with HIV. Older age, a longer exposure to PIs, and IFG were independent factors associated with common C-IMT in this population. 相似文献7.
Ian Brissette Ann Lowenfels Corina Noble Deborah Spicer 《Journal of nutrition education and behavior》2013,45(5):404-411
ObjectiveTo examine purchase patterns at fast-food restaurants and their relation to restaurant characteristics, customer characteristics, and use of calorie information.DesignCross-sectional survey.SettingFast-food restaurants in New York State.ParticipantsAdult fast-food restaurant customers (n = 1,094).Variables MeasuredRestaurant characteristics (fast-food chain type, presence of calorie labels, and poverty of location), participant characteristics (demographics, calorie knowledge, awareness, and use), and customer purchasing patterns (ordering low-calorie or no beverage, small or no fries, or < 3 items) were used as predictors of total calories purchased.AnalysisMultiple regression.ResultsIn a regression model including restaurant and customer characteristics, fast-food chain customer age, sex, calorie use, and calorie awareness were independently associated with total calories purchased (all P < .05; model R2 = .19). When 3 purchasing patterns were added to the model, calorie use (P = .005), but not calorie awareness, remained associated with total calories purchased. The 3 purchase patterns collectively accounted for the majority of variance in calorie totals (Δ model R2 = .40).Conclusions and ImplicationsPromoting use of calorie information, purchase strategies, and calorie awareness represents complementary ways to support lower-calorie choices at fast-food chains. 相似文献
8.
Neurocognitive predictors of substance use disorders and nicotine dependence in ADHD probands,their unaffected siblings,and controls: a 4‐year prospective follow‐up 下载免费PDF全文
9.
Philip Moons Koen Luyckx Corina Thomet Werner Budts Junko Enomoto Maayke A. Sluman Chun-Wei Lu Jamie L. Jackson Paul Khairy Stephen C. Cook Shanthi Chidambarathanu Luis Alday Katrine Eriksen Mikael Dellborg Malin Berghammer Bengt Johansson Andrew S. Mackie Samuel Menahem Adrienne H. Kovacs 《The Canadian journal of cardiology》2021,37(2):215-223
BackgroundWe compared physical functioning, mental health, and quality of life (QoL) of patients with different subtypes of congenital heart disease (CHD) in a large international sample and investigated the role of functional class in explaining the variance in outcomes across heart defects.MethodsIn the cross-sectional Assessment of Patterns of Patient-Reported Outcome in Adults with Congenital Heart Disease-International Study (APPROACH-IS), we enrolled 4028 adult patients with CHD from 15 countries. Diagnostic groups with at least 50 patients were included in these analyses, yielding a sample of 3538 patients (median age: 32 years; 52% women). Physical functioning, mental health, and QoL were measured with the SF-12 health status survey, Hospital Anxiety and Depression Scale (HADS), linear analog scale (LAS) and Satisfaction with Life Scale, respectively. Functional class was assessed using the patient-reported New York Heart Association (NYHA) class. Multivariable general linear mixed models were applied to assess the relationship between the type of CHD and patient-reported outcomes, adjusted for patient characteristics, and with country as random effect.ResultsPatients with coarctation of the aorta and those with isolated aortic valve disease reported the best physical functioning, mental health, and QoL. Patients with cyanotic heart disease or Eisenmenger syndrome had worst outcomes. The differences were statistically significant, above and beyond other patient characteristics. However, the explained variances were small (0.6% to 4.1%) and decreased further when functional status was added to the models (0.4% to 0.9%).ConclusionsSome types of CHD predict worse patient-reported outcomes. However, it appears that it is the functional status associated with the heart defect rather than the heart defect itself that shapes the outcomes. 相似文献
10.
Okusaka Takuji Ikeda Kenji Kudo Masatoshi Finn Richard Qin Shukui Han Kwang-Hyub Cheng Ann-Lii Piscaglia Fabio Kobayashi Masahiro Sung Max Chen Minshan Wyrwicz Lucjan Yoon Jung-Hwan Ren Zhenggang Mody Kalgi Dutcus Corina Tamai Toshiyuki Ren Min Hayato Seiichi Kumada Hiromitsu 《Journal of gastroenterology》2021,56(6):570-580
Journal of Gastroenterology - REFLECT was an open-label, phase 3 study comparing the efficacy and safety of lenvatinib versus sorafenib in patients with unresectable hepatocellular carcinoma... 相似文献