全文获取类型
| 收费全文 | 3000649篇 |
| 免费 | 232899篇 |
| 国内免费 | 5164篇 |
专业分类
| 耳鼻咽喉 | 43553篇 |
| 儿科学 | 89232篇 |
| 妇产科学 | 78681篇 |
| 基础医学 | 423180篇 |
| 口腔科学 | 88188篇 |
| 临床医学 | 270793篇 |
| 内科学 | 584859篇 |
| 皮肤病学 | 61459篇 |
| 神经病学 | 247607篇 |
| 特种医学 | 119304篇 |
| 外国民族医学 | 941篇 |
| 外科学 | 462017篇 |
| 综合类 | 68315篇 |
| 现状与发展 | 2篇 |
| 一般理论 | 1159篇 |
| 预防医学 | 233008篇 |
| 眼科学 | 70686篇 |
| 药学 | 227509篇 |
| 7篇 | |
| 中国医学 | 5872篇 |
| 肿瘤学 | 162340篇 |
出版年
| 2018年 | 29850篇 |
| 2016年 | 25550篇 |
| 2015年 | 28929篇 |
| 2014年 | 41252篇 |
| 2013年 | 62444篇 |
| 2012年 | 84370篇 |
| 2011年 | 88960篇 |
| 2010年 | 52452篇 |
| 2009年 | 50220篇 |
| 2008年 | 85070篇 |
| 2007年 | 90198篇 |
| 2006年 | 91555篇 |
| 2005年 | 89125篇 |
| 2004年 | 85928篇 |
| 2003年 | 82800篇 |
| 2002年 | 81737篇 |
| 2001年 | 145883篇 |
| 2000年 | 151129篇 |
| 1999年 | 127605篇 |
| 1998年 | 34976篇 |
| 1997年 | 31578篇 |
| 1996年 | 31399篇 |
| 1995年 | 30198篇 |
| 1994年 | 28352篇 |
| 1993年 | 26331篇 |
| 1992年 | 101978篇 |
| 1991年 | 98401篇 |
| 1990年 | 95043篇 |
| 1989年 | 91970篇 |
| 1988年 | 85034篇 |
| 1987年 | 83408篇 |
| 1986年 | 78860篇 |
| 1985年 | 75399篇 |
| 1984年 | 56267篇 |
| 1983年 | 47976篇 |
| 1982年 | 28026篇 |
| 1981年 | 24838篇 |
| 1980年 | 23229篇 |
| 1979年 | 52167篇 |
| 1978年 | 36260篇 |
| 1977年 | 30780篇 |
| 1976年 | 28316篇 |
| 1975年 | 30261篇 |
| 1974年 | 37210篇 |
| 1973年 | 35305篇 |
| 1972年 | 33204篇 |
| 1971年 | 30876篇 |
| 1970年 | 29089篇 |
| 1969年 | 27235篇 |
| 1968年 | 24724篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
21.
22.
23.
J. Rodríguez-Carrio A. Martínez-Zapico I. Cabezas-Rodríguez L. Benavente Á.I. Pérez-Álvarez P. López J.B. Cannata-Andía M. Naves-Díaz A. Suárez 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(2):135-143
Background and aims
Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.Methods and results
In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.Conclusion
SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE. 相似文献24.
Leonardo Jönck Staub Roberta Rodolfo Mazzali Biscaro Erikson Kaszubowski Rosemeri Maurici 《The Journal of emergency medicine》2019,56(1):53-69
Background
Lung ultrasound can accelerate the diagnosis of life-threatening diseases in adults with respiratory symptoms.Objective
Systematically review the accuracy of lung ultrasonography (LUS) for emergency diagnosis of pneumonia, acute heart failure, and exacerbation of chronic obstructive pulmonary disease (COPD)/asthma in adults.Methods
PubMed, Embase, Scopus, Web of Science, and LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde; until 2016) were searched for prospective diagnostic accuracy studies. Rutter-Gatsonis hierarchical summary receiver operating characteristic method was used to measure the overall accuracy of LUS and Reitsma bivariate model to measure the accuracy of the different sonographic signs. This review was previously registered in PROSPERO (Centre for Reviews and Dissemination, University of York, York, UK; CRD42016048085).Results
Twenty-five studies were included: 14 assessing pneumonia, 14 assessing acute heart failure, and four assessing exacerbations of COPD/asthma. The area under the summary receiver operating characteristic curve of LUS was 0.948 for pneumonia, 0.914 for acute heart failure, and 0.906 for exacerbations of COPD/asthma. In patients suspected to have pneumonia, consolidation had sensitivity of 0.82 (95% confidence interval [CI] 0.74–0.88) and specificity of 0.94 (95% CI 0.85–0.98) for this disease. In acutely dyspneic patients, modified diffuse interstitial syndrome had sensitivity of 0.90 (95% CI 0.87–0.93) and specificity of 0.93 (95% CI 0.91–0.95) for acute heart failure, whereas B-profile had sensitivity of 0.93 (95% CI 0.72–0.98) and specificity of 0.92 (95% CI 0.79–0.97) for this disease in patients with respiratory failure. In patients with acute dyspnea or respiratory failure, the A-profile without PLAPS (posterior-lateral alveolar pleural syndrome) had sensitivity of 0.78 (95% CI 0.67–0.86) and specificity of 0.94 (95% CI 0.89–0.97) for exacerbations of COPD/asthma.Conclusion
Lung ultrasound is an accurate tool for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of COPD/asthma. 相似文献25.
Christopher N. Cooley Tyler J. Beranek Matthew A. Warpinski Robert Alexander Amanda O. Esquivel 《The American journal of emergency medicine》2019,37(2):199-203
Introduction
In the United States there has been a large increase in participation in lacrosse for both males and females. The purpose of this study was to analyze the number of head injuries, injury rates (calculated using the reported number of participants) and types of head injuries that are seen in emergency departments in the United States.Methods
We compared injuries between male and female lacrosse participants. This was a retrospective study using a publicly available database produced by the US Consumer Product Safety Commission and information about lacrosse participation from US Lacrosse.Results
A linear regression was performed and showed a positive correlation between number of head injuries to males and time from 2002 to 2010 (R2?=?0.823; p?=?0.001). While the number of injuries to the head in female lacrosse participants was not significant. There was a negative correlation between the number of head injuries to males from 2010 to 2016 (R2?=?0.800; p?=?0.007), but again, there was no significance for female injury count (R2?=?0.417; p?=?0.117). Other significant differences between head injuries in males and females included the mechanism of injury and the type of injury recorded.Conclusion
The most recent data from 2010 to 2016, suggest that both males and females have had a decrease in injury rate. However the total number of female head injuries is not significantly decreasing and as the sport continues to grow there will likely be more total head injuries and visits to the emergency department. 相似文献26.
27.
ZusammenfassungHintergrund Bedingt durch die intraoperative Katecholaminsekretion mit hämodynamischen Veränderungen, einem größeren Tumordurchmesser und einer deutlichen Neovaskularisation ist die Adrenalektomie beim Phäochromozytom im Vergleich zu anderen Nebennierenerkrankungen schwieriger und potenziell komplikationsträchtiger. Ziel unserer Studie war die Frage, ob das Risiko intraoperativer kardiovaskulärer Komplikationen durch das minimal-invasive Vorgehen potenziert wird.Patienten und Methodik Im Zeitraum zwischen Februar 1992 und Mai 2005 wurden in unserer Klinik 82 Eingriffe wegen eines Phäochromozytoms bei 71 Patienten durchgeführt. Davon wurden 8 (1) Patient(en) bi-(tri-)lateral adrenalektomiert und bei 2 Patienten erfolgte eine ipsilaterale Rezidivoperation. Eingeschlossen sind 5 weitere Patienten mit Rezidiv nach Erstoperation vor 1992. Sechsunddreißig Eingriffe erfolgten konventionell (transperitoneal n=35, retroperitoneal n=1) und 46 Operationen endoskopisch (transperitoneal n=28, retroperitoneal n=18), davon keine Konversion zum offenen Vorgehen.Ergebnisse Das mediane Alter zum Zeitpunkt der Operation betrug 45 (24–75) Jahre bei einer Anamnesedauer von 12 (0–180) Monaten. Die offen operierten Phäochromozytome waren mit 5,5 (1–19) cm vs. 3,5 (0,5–8) cm (endoskopisch) signifikant größer (p=0,0011). Patienten mit endoskopischer, insbesondere mit retroperitoneoskopischer Adrenalektomie hatten im Vergleich zum konventionellen Vorgehen intraoperativ höhere systolische und diastolische maximale Blutdruckwerte sowie Spitzen über 200 mmHg (statistisch nicht signifikant). Faktoren mit möglichem Einfluss auf intraoperative hämodynamische Veränderungen waren in der multivariaten Analyse das Geschlecht (p=0,0107), der operative Zugangsweg (p=0,0153), das Patientenalter (p=0,0364) und die Tumorgröße (p=0,0484). Die postoperative stationäre Verweildauer war nach endoskopischer Operation signifikant kürzer (p<0,0001).Schlussfolgerung Die endoskopische Adrenalektomie beim Phäochromozytom ist in der Routine ohne vermehrtes Risiko kardiovaskulärer Komplikationen die Methode der Wahl. Das offene Vorgehen sollte extraadrenalen Befunden oder sehr großen Tumoren mit Malignitätsverdacht vorbehalten bleiben. 相似文献
28.
29.
D B Irving J L Cook H B Menz 《Journal of Science and Medicine in Sport》2006,9(1-2):11-22; discussion 23-4
30.
This study was undertaken to test the effect of sequential administration of an opioid and intravenous cholecystokinin (CCK) on gallbladder ejection fraction. METHODS: Forty-nine patients who had received an opioid underwent quantitative cholescintigraphy with octapeptide of CCK (CCK-8). Gallbladder ejection fraction and CCK-8-induced paradoxical filling were calculated. RESULTS: In the basal state, more of the hepatic bile entered the gallbladder (67%) than the small intestine (33%). After CCK-8 infusion, gallbladder ejection fraction was low in 37 (76%) of 49 patients and normal in 12 (24%). All 5 types of opioids lowered ejection fraction. CCK-induced paradoxical filling of the gallbladder was noted in 7 patients, but only one showed paradoxical filling of greater than 20% and none had a normal gallbladder ejection fraction. The lowering effect of opioids on gallbladder ejection fraction may last as long as 18 h after intake. CONCLUSION: CCK-8 produced a normal gallbladder ejection fraction in 24% of patients who had received an opioid and thus could exclude both acute and chronic cholecystitis during a single hepatobiliary study. 相似文献