全文获取类型
收费全文 | 405篇 |
免费 | 37篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 22篇 |
妇产科学 | 6篇 |
基础医学 | 62篇 |
口腔科学 | 9篇 |
临床医学 | 42篇 |
内科学 | 79篇 |
皮肤病学 | 6篇 |
神经病学 | 24篇 |
特种医学 | 20篇 |
外科学 | 48篇 |
综合类 | 3篇 |
一般理论 | 1篇 |
预防医学 | 32篇 |
眼科学 | 3篇 |
药学 | 32篇 |
肿瘤学 | 60篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 15篇 |
2013年 | 20篇 |
2012年 | 11篇 |
2011年 | 8篇 |
2010年 | 13篇 |
2009年 | 12篇 |
2008年 | 12篇 |
2007年 | 33篇 |
2006年 | 15篇 |
2005年 | 21篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 13篇 |
2001年 | 13篇 |
2000年 | 23篇 |
1999年 | 13篇 |
1998年 | 16篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 13篇 |
1991年 | 7篇 |
1990年 | 15篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
排序方式: 共有453条查询结果,搜索用时 15 毫秒
91.
Nancy L. Keating MD MPH Elena M. Kouri PhD Yulei He PhD Dee W. West PhD Eric P. Winer MD 《Cancer》2013,119(2):250-258
BACKGROUND:
Massachusetts law requires all residents to maintain a minimum level of health insurance, and rates of uninsurance in that state decreased from 6.4% in 2006 to 1.9% in 2010. The authors of this report assessed whether health insurance expansion was associated with use of mammography and earlier stage at breast cancer diagnosis.METHODS:
By using a prereform/postreform design with a concurrent control (California), mammography rates in the last year were assessed using the Behavioral Risk Factor Surveillance System survey and the diagnosis of stage I (vs II/III/IV) breast cancers based on cancer registry data among women ages 41 to 64. Propensity score analyses were used to compare California women who were most similar to women in Massachusetts with Massachusetts women.RESULTS:
Among propensity‐weighted cohorts, adjusted mammography rates in Massachusetts were 69.2% in 2006, 69.5% in 2008, and 69.0% in 2010. In California, the rates were 59% in 2006, 60.3% in 2008, and 56.2% in 2010 (P = .89 for interaction by state for 2010 vs 2006). Among propensity‐weighted cohorts, adjusted rates of diagnosis with stage I cancers were 52.2% in 2006, 53.5% in 2007, and 52.4% in 2008 in Massachusetts versus 46.4% in 2006, 46.3% in 2007, and 45.7% in 2008 in California (P = .58 for interaction by state for 2010 vs 2006).CONCLUSIONS:
Health insurance reform in Massachusetts was not associated with increased rates of mammography or earlier stage at diagnosis compared with California, possibly because of insurance and mammography rates that already were high. Additional research is needed to assess the impact of insurance expansions in other populations, especially those with higher uninsurance rates. Cancer 2013. © 2012 American Cancer Society. 相似文献92.
Background
Selection of patients with local failure of nasopharyngeal carcinoma (NPC) for appropriate type of salvage treatment can be difficult due to the lack of data on comparative efficacy of different salvage treatments. The purpose of the present study was to validate a previously published prognostic scoring system for local failures of NPC treated by radiosurgery based on reported results in the literature. 相似文献93.
Background
Oral submucous fibrosis is a common oral health problem in India. This study was conducted to correlate the histopathological diagnosis with habits and clinical findings in patients suffering from oral submucous fibrosis (OSF).Methods
Patients suffering from oral submucous fibrosis from the Departments of Otorhinolayngology and Pathology, Moti Lal Nehru Medical College, Allahabad, India were studied from 2004–2008. Detailed information was gathered in a pretested proforma. Emphasis was given to the various addictions, clinical findings and histological examination was done.Results
Two hundred and thirty nine patients were studied, yielding a male to female ratio of 6.8:1. Maximum patients were in the 21–30 years age group with a marked male predominance. Of these, 197 (82.4%) patients chewed areca nut/dohra, 14 (5.8%) were smokers and 2 (0.8%) patients were habituated to alcohol. 89(37.2%) patients reported difficulty in opening of the mouth (trismus). 51 (57.4%) patients were found to have stage II (2–3 cm) trismus while rest had stage I and III. The buccal mucosa was found to be the most commonly involved site. On the basis of histopathological examination, 52(21.7%) were classified as OSF grade I, 75(31.3%) patients as grade II and 112(46.8%) had grade III disease.Conclusion
The widespread habit of chewing dohra/paan masala is a major risk factor of OSF, especially in the younger age group. In this study, an increase in histopathological grading was found with severity and duration of addiction habit. However no significant correlation was found between clinical staging and histopathological grading. 相似文献94.
95.
KKL Chan BCP Chan KF Lam S Tam TT Lao 《BJOG : an international journal of obstetrics and gynaecology》2009,116(6):789-798
Objective To test the hypothesis that iron supplement from early pregnancy would increase the risk of gestational diabetes mellitus (GDM).
Design Randomised placebo-controlled trial.
Setting A university teaching hospital in Hong Kong.
Population One thousand one hundred sixty-four women with singleton pregnancy at less than 16 weeks of gestation with haemoglobin (Hb) level between 8 and 14 g/dl and no pre-existing diabetes or haemoglobinopathies.
Methods Women were randomly allocated to receive 60 mg of iron supplement daily ( n = 565) or placebo ( n = 599). Oral glucose tolerance tests (OGTTs) were performed at 28 and 36 weeks. Women were followed up until delivery.
Outcome measures The primary outcome was development of GDM at 28 weeks. The secondary outcomes were 2-hour post-OGTT glucose levels, development of GDM at 36 weeks and delivery and infant outcomes.
Results There was no significant difference in the incidence of GDM in the iron supplement and placebo groups at 28 weeks (OR: 1.04, 95% confidence interval [CI]: 0.7–1.53 at 90% power) or 36 weeks. Maternal Hb and ferritin levels were higher in the iron supplement group at delivery ( P < 0.001 and P = 0.003, respectively). Elective caesarean section rate was lower in the iron supplement group (OR: 0.58, 95% CI: 0.37–0.89). Infant birthweight was heavier ( P = 0.001), and there were fewer small-for-gestational-age babies in the iron supplement group (OR: 0.46, 95% CI: 0.24–0.85).
Conclusion Iron supplement from early pregnancy does not increase the risk of GDM. It may have benefits in terms of pregnancy outcomes. 相似文献
Design Randomised placebo-controlled trial.
Setting A university teaching hospital in Hong Kong.
Population One thousand one hundred sixty-four women with singleton pregnancy at less than 16 weeks of gestation with haemoglobin (Hb) level between 8 and 14 g/dl and no pre-existing diabetes or haemoglobinopathies.
Methods Women were randomly allocated to receive 60 mg of iron supplement daily ( n = 565) or placebo ( n = 599). Oral glucose tolerance tests (OGTTs) were performed at 28 and 36 weeks. Women were followed up until delivery.
Outcome measures The primary outcome was development of GDM at 28 weeks. The secondary outcomes were 2-hour post-OGTT glucose levels, development of GDM at 36 weeks and delivery and infant outcomes.
Results There was no significant difference in the incidence of GDM in the iron supplement and placebo groups at 28 weeks (OR: 1.04, 95% confidence interval [CI]: 0.7–1.53 at 90% power) or 36 weeks. Maternal Hb and ferritin levels were higher in the iron supplement group at delivery ( P < 0.001 and P = 0.003, respectively). Elective caesarean section rate was lower in the iron supplement group (OR: 0.58, 95% CI: 0.37–0.89). Infant birthweight was heavier ( P = 0.001), and there were fewer small-for-gestational-age babies in the iron supplement group (OR: 0.46, 95% CI: 0.24–0.85).
Conclusion Iron supplement from early pregnancy does not increase the risk of GDM. It may have benefits in terms of pregnancy outcomes. 相似文献
96.
97.
The aim of the present study was to examine whether ischaemic episodes of less than 5 min could induce preconditioning or stunning in the isolated rat heart. Hearts were subjected to total global ischaemia of 1, 2 and 4 min followed by 10 min of reperfusion before an 18-min main ischaemic period and 30 min of reperfusion. The effects on physiology, purine metabolism and anaerobic glycolysis were compared with a control group subjected to the main ischaemia only. The brief ischaemic episodes did not produce stunning based on the recovery of left ventricular developed pressure (LVDP) and heart rate (HR) product during the first reperfusion. Preconditioning of 11–14% increased recovery of LVDP x HR during the second reperfusion was observed in the 1- and 4-min group. In the 2-min group a low repayment of flow debt during the first reperfusion was associated with a slightly reduced recovery of LVDP x HR compared to the other preconditioned groups during the second reperfusion. Only in the 4-min group was preconditioning associated with fewer breakdown products of the purine nucleotide pool (adenosine) and anaerobic glycolysis (lactate) in both tissue and effluate after the main ischaemia. Preconditioning (reflected in recovery of function) could be produced with ischaemic episodes of less than 5 min that did not produce stunning. Thus, stunning is probably not the primary cause of preconditioning. 相似文献
98.
Ray CE English B Funaki BS Burke CT Fidelman N Ginsburg ME Kinney TB Kostelic JK Kouri BE Lorenz JM Nair AV Nemcek AA Owens CA Saleh AG Vatakencherry G Mohammed TL 《Journal of the American College of Radiology》2012,9(1):13-19
Pulmonary and mediastinal masses represent a wide range of pathologic processes with very different treatment options. Although advances in imaging (such as PET and high-resolution CT) help in many cases with the differential diagnosis of thoracic pathology, tissue samples are frequently needed to determine the best management for patients presenting with thoracic masses. There are many options for obtaining tissue samples, each of which has its own set of benefits and drawbacks. The purposes of this report are to present the most current evidence regarding biopsies of thoracic nodules and masses and to present the most appropriate options for select common clinical scenarios. The ACR Appropriateness Criteria(?) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. 相似文献
99.
Ioannis A. Tsolakis Stavros K. Kakkos Chrysanthi P. Papageorgopoulou Peter Zampakis Christina Kalogeropoulou Spyros Papadoulas George Lampropoulos Konstantinos M. Nikolakopoulos Ioannis Ntouvas Anastasia Kouri 《Journal of vascular surgery》2019,69(2):394-404
Objective
To compare two endograft types, the original GORE EXCLUDER AAA endoprosthesis (W. L. Gore & Associates, Flagstaff, Ariz) with the repositionable GORE EXCLUDER featuring the C3 delivery system, which allows repositioning of the proximal part of the graft to achieve accurate placement in relation to the renal arteries, in unselected patients with aortoiliac aneurysms. In a second nested, substudy we investigated the relative effect of the standard Gore and Gore Dryseal introducer sheaths on intraoperative transfusion needs.Methods
We retrospectively analyzed prospectively collected information. The primary composite outcome measure was the intraoperative misdeployment or migration of the endograft's main body, proximally or distally to the renals (leading to technical failure or requiring either placement of aortic cuff extenders or conversion to open repair). Secondary outcome measures included the composite long-term event of rupture and/or type I/III endoleak.Results
A total of 313 consecutive patients (303 males; median age, 73 years) had either an original GORE EXCLUDER device (n = 174) or the new device (n = 139) placed between 2004 and 2011 and 2011 and 2017, respectively, to treat an infrarenal aortoiliac aneurysm or an isolated common iliac artery aneurysm. The primary composite outcome measure occurred more often in patients who had the original GORE EXCLUDER device placed (10.9% vs 3.6% for the new device; odds ratio, 0.30; 95% confidence interval, 0.11-0.84; P = .016), confirmed by multivariate logistic regression analysis. This difference between the two groups was exclusively driven by distal misdeployment or migration of the endograft (10.3% vs 2.9% for the new device; P = .01), mostly requiring aortic extender placement. Intraoperative blood transfusion rates were lower in patients who had the GORE Dryseal introducer sheath used (1.1% vs 18.9% for the original GORE introducer sheath; OR, 0.05; 95% confidence interval, 0.006-0.35; P < .001). At a mean follow-up of 1.7 years (maximum, 13 years), 11 patients developed the composite event. On univariate Cox analysis, significant predictors included female gender (P = .003), absence of dyslipidemia (P = .023), the primary outcome measure (P = .006), and failure to cannulate (P = .009), but not device type or other variables. On multivariate Cox regression, female gender (hazard ratio, 37; P < .001), chronic obstructive pulmonary disease (hazard ratio, 3.99; P = .045), the primary outcome measure of the study (hazard ratio, 8.9; P = .002), and failure to cannulate (hazard ratio, 43; P = .003) were all independent predictors.Conclusions
Our study has demonstrated that the repositionable GORE EXCLUDER has important safety characteristics compared with the original device and equivalent long-term effectiveness. Additional benefit was obtained with the use of the Gore Dryseal introducer sheath. 相似文献100.