全文获取类型
收费全文 | 14554篇 |
免费 | 1460篇 |
国内免费 | 365篇 |
专业分类
耳鼻咽喉 | 173篇 |
儿科学 | 393篇 |
妇产科学 | 254篇 |
基础医学 | 924篇 |
口腔科学 | 209篇 |
临床医学 | 1782篇 |
内科学 | 3022篇 |
皮肤病学 | 176篇 |
神经病学 | 714篇 |
特种医学 | 503篇 |
外国民族医学 | 3篇 |
外科学 | 2068篇 |
综合类 | 1738篇 |
现状与发展 | 2篇 |
预防医学 | 1355篇 |
眼科学 | 177篇 |
药学 | 1396篇 |
67篇 | |
中国医学 | 735篇 |
肿瘤学 | 688篇 |
出版年
2024年 | 129篇 |
2023年 | 613篇 |
2022年 | 1046篇 |
2021年 | 1450篇 |
2020年 | 1309篇 |
2019年 | 1089篇 |
2018年 | 1014篇 |
2017年 | 834篇 |
2016年 | 679篇 |
2015年 | 603篇 |
2014年 | 1196篇 |
2013年 | 1140篇 |
2012年 | 728篇 |
2011年 | 699篇 |
2010年 | 508篇 |
2009年 | 518篇 |
2008年 | 465篇 |
2007年 | 417篇 |
2006年 | 354篇 |
2005年 | 270篇 |
2004年 | 229篇 |
2003年 | 159篇 |
2002年 | 144篇 |
2001年 | 97篇 |
2000年 | 72篇 |
1999年 | 58篇 |
1998年 | 71篇 |
1997年 | 69篇 |
1996年 | 61篇 |
1995年 | 43篇 |
1994年 | 38篇 |
1993年 | 36篇 |
1992年 | 35篇 |
1991年 | 25篇 |
1990年 | 21篇 |
1989年 | 21篇 |
1988年 | 19篇 |
1987年 | 14篇 |
1986年 | 11篇 |
1985年 | 24篇 |
1984年 | 19篇 |
1983年 | 13篇 |
1982年 | 10篇 |
1981年 | 10篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
Comparative outcomes of vascular access in patients older than 70 years with end-stage renal disease
Deokbi Hwang Sujin Park Hyung-Kee Kim Seung Huh 《Journal of vascular surgery》2019,69(4):1196-1206.e5
Objective
The advantage of arteriovenous fistulas (AVFs) in older patients requiring dialysis is controversial. We reviewed our vascular access experience in patients ≥70 years of age (older group) compared with younger patients.Methods
We analyzed consecutive patients who underwent access surgery between 2013 and 2016. Primary success (PS) and primary patency (PP) data were analyzed between the older and younger groups before and after propensity score matching of the patients' characteristics and access composition. PS was defined as the achievement of access function that was amenable to two sessions of successful cannulation without early occlusion or maturation failure requiring revision. PP was defined as the time with uninterrupted patency without intervention.Results
A total of 594 consecutive accesses were created among 563 patients, of whom 119 were allocated into each group after propensity score matching. In the whole cohort, 193 accesses (32.5%) were performed in older patients. AVFs were performed in 130 (67.4%) older patients and 293 (73.1%) younger patients. Regarding AVFs, the PS rate (83.6% in the older group vs 94.3% in the younger group; P = .001) and the overall PP at 6 and 12 months (73.1% and 57.1%, respectively, in the older group vs 86.7% and 77.7%, respectively, in the younger group; P = .009) were lower in the older group than in the younger group. However, no differences were found in the PS and PP rates for arteriovenous grafts between groups. Regarding the AVF location, the PS rate for forearm AVFs was significantly lower in the older group than in the younger group (76% vs 93%; P < .001); however, the PS rate of the upper arm was not different between the groups (94% vs 97%; P = .425). In the patients with PS, the PP rate of AVFs was similar between the two groups. In the older group with forearm AVFs, the median diameter of the radial artery was larger in the patients with PS than in the patients without PS (2.20 mm with PS vs 2.00 mm without PS; P = .008). The propensity score matching results demonstrated similar trends for the whole cohort, with lower PS (P = .042) and PP rates (P = .023) for AVF in the older group.Conclusions
The outcomes after AVF were poorer in the older group than in the younger group, which was primarily due to unsatisfactory outcomes in patients with forearm AVFs. Thus, stricter criteria, especially regarding the radial artery diameter, should be applied for forearm AVFs in older patients, and additional research is necessary to delineate the risk factors for primary failure. 相似文献4.
K.-C. Sung D.-C. Seo S.-J. Lee M.-Y. Lee S.H. Wild C.D. Byrne 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(5):489-495
Background and aims
It is not known whether non alcoholic fatty liver disease (NAFLD) is a risk factor for diabetes in non obese, non centrally-obese subjects. Our aim was to investigate relationships between fatty liver, insulin resistance and a biomarker score for liver fibrosis with incident diabetes at follow up, in subjects who were neither obese nor centrally-obese.Methods and results
As many as 70,303 subjects with a body mass index (BMI) < 25 kg/m2 and without diabetes were followed up for a maximum of 7.9 years. At baseline, fatty liver was identified by liver ultrasound, insulin resistance (IR) by homeostatic model assessment of insulin resistance (HOMA-IR) ≥2.0, and central obesity by waist circumference (waist circumference ≥90 cm (men) and ≥85 cm (women). The Fibrosis-4 (FIB-4 score) was used to estimate extent of liver fibrosis. Cox proportional hazards models adjusted for confounders were used to estimate hazard ratios (aHRs) for incident diabetes. As many as 852 incident cases of diabetes occurred during follow up (median [IQR] 3.71 [2.03] years). Mean ± SD BMI was 22.8 ± 1.8 and 21.7 ± 2.0 kg/m2 in subjects with and without diabetes at follow up. In subjects without central obesity and with fatty liver, aHRs (95% CI) for incident diabetes at follow up were 2.17 (1.56, 3.03) for men, and 2.86 (1.50,5.46) for women. Similar aHRs for incident diabetes occurred with fatty liver, IR and the highest quartile of FIB-4 combined, in men; and there was a non significant trend toward increased risk in women.Conclusions
In normal weight, non-centrally obese subjects NAFLD is an independent risk factor for incident diabetes. 相似文献5.
AbstractPurpose: In the context of assistive technology, mobility takes the meaning of “moving safely, gracefully, and comfortably”.The aim of this article is to provide a system which will be a convenient means of navigation for the Visually Impaired people, in the public transport system.Method: A blind regular commuter who travels by public transport facility finds difficulty in identifying the vehicle that is nearing the stop. Hence, a real-time system that dynamically identifies the nearing vehicle and informs the commuters is necessary. This paper proposes such a system namely the “Vehicle Board Recognition System” (VBRS). Computer Vision techniques such as segmentation, object recognition, text detection and optical character recognition are utilized to build the system, which will detect, analyze, derive and communicate the information to the passengers.Results: Thanks to the rapid development in technology, there are several navigation systems both hand held and wearable, available to help visually impaired (VI) people move comfortably both indoor and outdoor. Many blind people are not comfortable in using these devices or they are not affordable for them. Thus the proposed system gives them the comfort of navigation.Conclusion: This system can be installed in the bus stop to assist the Visually Impaired, from externally rather than their hand held or wearable assistive devices.
- Implications for rehabilitation
This proposed system will help the visually impaired to
ensure secure navigation
be independent of the others
develop self confidence.
overcome the training, affordability of wearable/ handheld devices.
6.
7.
目的分析各种因素对手工凝聚胺试验的影响;方法应用手工凝聚胺(manual polgbrene test,MPT)做交叉配血及抗体筛选试验;结果血液标本、操作手法、凝聚胺试剂、药物(肝素、止血敏、高浓度KCl等)等对试验均有影响;其中以药物、操作手法影响较大,可致假阴性和假阳性结果;结论手工凝聚胺试验做交叉配血及抗体筛选时应注意排除药物和操作手法对试验结果的影响。 相似文献
8.
9.
Workplace status and risk of hypertension among hourly and salaried aluminum manufacturing employees
Jane Ellen Clougherty Ellen A. Eisen Martin D. Slade Ichiro Kawachi Mark R. Cullen 《Social science & medicine (1982)》2009
An inverse relationship between workplace status and morbidity is well established; higher job status has been associated with reduced risks of heart disease, hypertension, and injury. Most research on job status, however, has focused on salaried populations, and it remains unclear whether job status operates similarly among hourly workers. Our objectives were to examine whether hourly status itself influences risk of hypertension after adjustment for socioeconomic confounders, and to explore the role of fine-scale job grade on hypertension incidence within hourly and salaried groups. We examined data for 14,999 aluminum manufacturing employees in 11 plants across the U.S., using logistic regression with adjustment for age, sex, race/ethnicity and other individual characteristics. Propensity score restriction was used to identify comparable groups of hourly and salaried employees, reducing confounding by sociodemographic characteristics. Job grade (coded 1 through 30, within hourly and salaried groups) was examined as a more refined measure of job status. Hourly status was associated with an increased risk of hypertension, after propensity restriction and adjustment for confounders. The observed effect of hourly status was stronger among women, although the propensity-restricted cohort was disproportionately male (96%). Among salaried workers, higher job grade was not consistently associated with decreased risk; among hourly employees, however, there was a significant trend, with higher job grades more protective against hypertension. Increasing the stringency of hypertension case criteria also increased the risk of severe or persistent hypertension for hourly employees. 相似文献
10.
B. S. Sharma Sumit Sinha V. S. Mehta A. Suri Aditya Gupta A. K. Mahapatra 《Child's nervous system》2007,23(3):327-333
Object Intracranial aneurysms are rare in children and have different epidemiological, clinical, and morphological characteristics
and outcome from those in adults.
Materials and methods We analyzed demographic, clinical, radiologic features, treatment, and outcome in 55 patients <18 years of age, treated from
Jan 1995 through December 2005.
Results Intracranial aneurysms in children below 18 years constituted 4% of all intracranial aneurysms. Internal Carotid artery (ICA)
bifurcation was the commonest location. About half of the aneurysms were complex. Three-fourth of the patients required surgical
treatment. Two patients died, constituting 5% mortality. Two patients (5%) had poor outcome, whereas the majority (90%) had
a favorable outcome.
Conclusions Pediatric aneurysms have male predominance, higher incidence of clinical features of mass effect or seizures, high incidence
of large, traumatic/mycotic aneurysms, associated illnesses and ICH/IVH and hydrocephalus, better Hunt and Hess grades at
presentation, ICA bifurcation as the commonest site, and better outcome than their adult counterparts. 相似文献