全文获取类型
收费全文 | 4493篇 |
免费 | 308篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 168篇 |
妇产科学 | 72篇 |
基础医学 | 693篇 |
口腔科学 | 68篇 |
临床医学 | 446篇 |
内科学 | 835篇 |
皮肤病学 | 66篇 |
神经病学 | 489篇 |
特种医学 | 129篇 |
外国民族医学 | 1篇 |
外科学 | 642篇 |
综合类 | 52篇 |
一般理论 | 7篇 |
预防医学 | 529篇 |
眼科学 | 59篇 |
药学 | 263篇 |
中国医学 | 6篇 |
肿瘤学 | 300篇 |
出版年
2023年 | 55篇 |
2022年 | 93篇 |
2021年 | 146篇 |
2020年 | 91篇 |
2019年 | 109篇 |
2018年 | 117篇 |
2017年 | 81篇 |
2016年 | 93篇 |
2015年 | 132篇 |
2014年 | 173篇 |
2013年 | 229篇 |
2012年 | 287篇 |
2011年 | 333篇 |
2010年 | 171篇 |
2009年 | 170篇 |
2008年 | 238篇 |
2007年 | 246篇 |
2006年 | 266篇 |
2005年 | 257篇 |
2004年 | 237篇 |
2003年 | 196篇 |
2002年 | 164篇 |
2001年 | 44篇 |
2000年 | 34篇 |
1999年 | 42篇 |
1998年 | 59篇 |
1997年 | 36篇 |
1996年 | 43篇 |
1995年 | 36篇 |
1994年 | 38篇 |
1993年 | 34篇 |
1992年 | 43篇 |
1991年 | 26篇 |
1990年 | 34篇 |
1989年 | 37篇 |
1988年 | 39篇 |
1987年 | 29篇 |
1986年 | 36篇 |
1985年 | 37篇 |
1984年 | 28篇 |
1983年 | 21篇 |
1982年 | 28篇 |
1981年 | 14篇 |
1979年 | 28篇 |
1978年 | 20篇 |
1977年 | 13篇 |
1976年 | 18篇 |
1975年 | 15篇 |
1972年 | 11篇 |
1969年 | 10篇 |
排序方式: 共有4854条查询结果,搜索用时 15 毫秒
101.
102.
B. Joseph Elmunzer Rebecca L. Spitzer Lydia D. Foster Ambreen A. Merchant Eric F. Howard Vaishali A. Patel Mary K. West Emad Qayed Rosemary Nustas Ali Zakaria Marc S. Piper Jason R. Taylor Lujain Jaza Nauzer Forbes Millie Chau Luis F. Lara Georgios I. Papachristou Michael L. Volk Valerie Durkalski 《Clinical gastroenterology and hepatology》2021,19(7):1355-1365.e4
103.
Leticia Leon Lydia Abasolo Benjamin Fernandez-Gutierrez Juan Angel Jover Cesar Hernandez-Garcia 《Reumatología clinica》2018,14(1):4-8
Objective
To analyze the resource utilization in rheumatoid arthritis (RA) patients and predictive factors in and patients treated with biological drugs and biologic-naïve.Methods
A cross-sectional study was performed in a sample including all regions and hospitals throughout the country. Sociodemographic data, disease activity parameters and treatment data were obtained. Resource utilization for two years of study was recorded and we made costs imputation. Correlation analyzes were performed on all RA patients and those treated with biological and biological naïve, to estimate the differences in resource utilization. Factors associated with increased resources utilization (costs) attending to treatment was analyzed by linear regression models.Results
We included 1,095 RA patients, 26% male, mean age of 62 ± 14 years. Mean of direct medical costs per patient was €24,291 ± €45,382. Excluding biological drugs, the average cost per patient was €3,742 ± €3,711. After adjustment, factors associated with direct medical costs for all RA patients were biologic drugs (P = .02) and disease activity (P = .004). In the biologic-naïve group, the predictor of direct medical costs was comorbidity (P < .001). In the biologic treatment group predictors were follow-up length of the disease (P = .04), age (P = .02) and disease activity (P = .007).Conclusion
Our data show a remarkable economic impact of RA. It is important to identify and estimate the economic impact of the disease, compare data from other geographic samples and to develop improvement strategies to reduce these costs and increase the quality of care. 相似文献104.
Virtanen I Korhonen M Petäjäniemi N Karhunen T Thornell LE Sorokin LM Konttinen YT 《The Journal of clinical endocrinology and metabolism》2003,88(10):4960-4966
Laminin has been proposed to influence the function of human adrenal cortex. We have studied the distribution of laminin (Ln) chains using immunofluorescence in human fetal and adult adrenal cortex. In the fetal gland Ln alpha2- and alpha5-chains were weakly expressed in the definitive zone, whereas Ln alpha4-, beta1-, and gamma1-chains occurred around vessels. In the adult gland, Ln alpha2-, alpha5-, and gamma1-chains were found in epithelial basement membranes (BM) in all cortical zones, Ln alpha4-chain in vessels, Ln beta1-chain in outer zone, and Ln beta2-chain in the two inner zones of the cortex, respectively. Among the integrins in adult gland, integrin alpha(3)-subunit was confined to basal surfaces of cortical cells, alpha(6) to vessels, alpha(1) to the stroma, and alpha(2) diffusely to epithelial cells. Lutheran glycoprotein and dystroglycan occurred in the fetal gland diffusely in the definitive zone and throughout the epithelium in the adult. The isoform composition of BM of the adult adrenal gland is distinct, with Ln-2 and -10 in BM of the outer zone and Ln-4 and -11 in BM of the two inner zones. The results suggest that integrin alpha(3)beta(1) and Lutheran are candidate receptors for Ln-10 and -11, whereas dystroglycan probably binds Ln-2 and -4. 相似文献
105.
Methotrexate: bioavailability and pharmacokinetics 总被引:1,自引:0,他引:1
M A Campbell D G Perrier R T Dorr D S Alberts P R Finley 《Cancer treatment reports》1985,69(7-8):833-838
Six adult patients with squamous cell carcinoma of the head and neck were treated with single low doses of methotrexate (MTX) (30 mg/m2) iv, im, and orally in the form of commercial tablets. A randomized crossover design was employed. Plasma concentrations were measured by a modified EMIT assay over a period of 24 hours following each dose. The mean (+/- SD) parameters following iv MTX were as follows: total-body clearance, 124 (36) ml/minute; Vss, 0.56 (0.18) L/kg; V lambda, 0.69 (0.24) L/kg; and beta-half-life, 3.20 hours. The absolute systemic bioavailability of the oral tablets was 36% (+/- 10%). After im administration, the systemic bioavailability was 93% (+/- 14%). Dose-dependent gastrointestinal absorption is suggested as the mechanism for the low availability of the oral tablets. Administration of MTX by the oral route will require further study to determine the optimal method of dosing. 相似文献
106.
Alain P. Gobert Olivier Boutaud Mohammad Asim Irene A. Zagol-Ikapitte Alberto G. Delgado Yvonne L. Latour Jordan L. Finley Kshipra Singh Thomas G. Verriere Margaret M. Allaman Daniel P. Barry Kara M. McNamara Johanna C. Sierra Venkataraman Amarnath Mohammed N. Tantawy Diane Bimczok M. Blanca Piazuelo M. Kay Washington Keith T. Wilson 《Gastroenterology》2021,160(4):1256-1268.e9
- Download : Download high-res image (348KB)
- Download : Download full-size image
107.
108.
Romina Lomonaco Eddison Godinez Leiva Fernando Bril Sulav Shrestha Lydia Mansour Jeff Budd Jessica Portillo Romero Siegfried Schmidt Ku-Lang Chang George Samraj John Malaty Katherine Huber Pierre Bedossa Srilaxmi Kalavalapalli Jonathan Marte Diana Barb Danielle Poulton Nada Fanous Kenneth Cusi 《Diabetes care》2021,44(2):399
OBJECTIVEAssess the prevalence of nonalcoholic fatty liver disease (NAFLD) and of liver fibrosis associated with nonalcoholic steatohepatitis in unselected patients with type 2 diabetes mellitus (T2DM).RESEARCH DESIGN AND METHODSA total of 561 patients with T2DM (age: 60 ± 11 years; BMI: 33.4 ± 6.2 kg/m2; and HbA1c: 7.5 ± 1.8%) attending primary care or endocrinology outpatient clinics and unaware of having NAFLD were recruited. At the visit, volunteers were invited to be screened by elastography for steatosis and fibrosis by controlled attenuation parameter (≥274 dB/m) and liver stiffness measurement (LSM; ≥7.0 kPa), respectively. Secondary causes of liver disease were ruled out. Diagnostic panels for prediction of advanced fibrosis, such as AST-to-platelet ratio index (APRI) and Fibrosis-4 (FIB-4) index, were also measured. A liver biopsy was performed if results were suggestive of fibrosis.RESULTSThe prevalence of steatosis was 70% and of fibrosis 21% (LSM ≥7.0 kPa). Moderate fibrosis (F2: LSM ≥8.2 kPa) was present in 6% and severe fibrosis or cirrhosis (F3–4: LSM ≥9.7 kPa) in 9%, similar to that estimated by FIB-4 and APRI panels. Noninvasive testing was consistent with liver biopsy results. Elevated AST or ALT ≥40 units/L was present in a minority of patients with steatosis (8% and 13%, respectively) or with liver fibrosis (18% and 28%, respectively). This suggests that AST/ALT alone are insufficient as initial screening. However, performance may be enhanced by imaging (e.g., transient elastography) and plasma diagnostic panels (e.g., FIB-4 and APRI).CONCLUSIONSModerate-to-advanced fibrosis (F2 or higher), an established risk factor for cirrhosis and overall mortality, affects at least one out of six (15%) patients with T2DM. These results support the American Diabetes Association guidelines to screen for clinically significant fibrosis in patients with T2DM with steatosis or elevated ALT. 相似文献
109.
110.
Michael Marxen Mark J. Jacob Lydia Hellrung Philipp Riedel Michael N. Smolka 《Human brain mapping》2021,42(5):1257
Our senses are constantly monitoring the environment for emotionally salient stimuli that are potentially relevant for survival. Because of our limited cognitive resources, emotionally salient distractors prolong reaction times (RTs) as compared to neutral distractors. In addition, many studies have reported fMRI blood oxygen level‐dependent (BOLD) activation of both the amygdala and the anterior insula for similar valence contrasts. However, a direct correlation of trail‐by‐trial BOLD activity with RTs has not been shown, yet, which would be a crucial piece of evidence to relate the two observations. To investigate the role of the above two regions in the context of emotional distractor effects, we study here the correlation between BOLD activity and RTs for a simple attentional capture by emotional stimuli (ACES) choice reaction time task using a general linear subject‐level model with a parametric RT regressor. We found significant regression coefficients in the anterior insula, supplementary motor cortex, medial precentral regions, sensory‐motor areas and others, but not in the amygdala, despite activation of both insula and amygdala in the traditional valence contrast across trials (i.e., negative vs. neutral pictures). In addition, we found that subjects that exhibit a stronger RT distractor effect across trials also show a stronger BOLD valence contrast in the right anterior insula but not in the amygdala. Our results indicate that the current neuroimaging‐based evidence for the involvement of the amygdala in RT slowing is limited. We advocate that models of emotional capture should incorporate both the amygdala and the anterior insula as separate entities. 相似文献