全文获取类型
收费全文 | 455篇 |
免费 | 42篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 11篇 |
妇产科学 | 14篇 |
基础医学 | 42篇 |
口腔科学 | 33篇 |
临床医学 | 79篇 |
内科学 | 79篇 |
皮肤病学 | 3篇 |
神经病学 | 19篇 |
特种医学 | 13篇 |
外国民族医学 | 1篇 |
外科学 | 52篇 |
预防医学 | 46篇 |
药学 | 49篇 |
肿瘤学 | 54篇 |
出版年
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 12篇 |
2019年 | 10篇 |
2018年 | 20篇 |
2017年 | 11篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 20篇 |
2012年 | 28篇 |
2011年 | 25篇 |
2010年 | 11篇 |
2009年 | 11篇 |
2008年 | 30篇 |
2007年 | 22篇 |
2006年 | 21篇 |
2005年 | 25篇 |
2004年 | 24篇 |
2003年 | 12篇 |
2002年 | 14篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 8篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 3篇 |
1992年 | 5篇 |
1990年 | 4篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 11篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1978年 | 10篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 5篇 |
1971年 | 4篇 |
1970年 | 7篇 |
1969年 | 3篇 |
1963年 | 2篇 |
1961年 | 2篇 |
1959年 | 2篇 |
排序方式: 共有497条查询结果,搜索用时 0 毫秒
81.
Aune D Chan DS Vieira AR Rosenblatt DA Vieira R Greenwood DC Norat T 《Breast cancer research and treatment》2012,134(2):479-493
Evidence for an association between fruit and vegetable intake and breast cancer risk is inconclusive. To clarify the association, we conducted a systematic review and meta-analysis of the evidence from prospective studies. We searched PubMed for prospective studies of fruit and vegetable intake and breast cancer risk until April 30, 2011. We included fifteen prospective studies that reported relative risk estimates and 95 % confidence intervals (CIs) of breast cancer associated with fruit and vegetable intake. Random effects models were used to estimate summary relative risks. The summary relative risk (RR) for the highest versus the lowest intake was 0.89 (95 % CI: 0.80-0.99, I (2) = 0 %) for fruits and vegetables combined, 0.92 (95 % CI: 0.86-0.98, I (2) = 9 %) for fruits, and 0.99 (95 % CI: 0.92-1.06, I (2) = 20 %) for vegetables. In dose-response analyses, the summary RR per 200 g/day was 0.96 (95 % CI: 0.93-1.00, I (2) = 2 %) for fruits and vegetables combined, 0.94 (95 % CI: 0.89-1.00, I (2) = 39 %) for fruits, and 1.00 (95 % CI: 0.95-1.06, I (2) = 17 %) for vegetables. In this meta-analysis of prospective studies, high intake of fruits, and fruits and vegetables combined, but not vegetables, is associated with a weak reduction in risk of breast cancer. 相似文献
82.
Saelen MG Prøsch LK Gudmundsdottir H Dyrbekk D Helge Hunderi O Arnesen E Paulsen D Skjønsberg H Os I 《Blood pressure》2005,14(3):170-176
This study compared the use of antihypertensive treatment and blood pressure (BP) controls between patients with diabetic kidney disease (DK+) and patients with non-diabetic kidney disease (DK-) exhibiting moderate-to-severe chronic renal failure who did not need renal replacement therapy. A cross-sectional survey included all renal patients with s-creatinine at ?200 micromol/l attending regular control sessions at six renal units in Norway. Of the 351 patients included, 73 (20.8%) were DK+. The proportion reaching a BP goal of <130/80 mmHg was similar in DK+ and DK- (14.1% vs 13.6%, p = 0.92), while 38% and 39% achieved a BP of <140/90 mmHg, respectively. The systolic BP goal was more difficult to achieve than the diastolic BP goal in DK+ patients (35% vs 15%) despite a mean of three different types of drugs being used. Loop diuretics and beta-adrenergic-receptor antagonists were the most frequently prescribed drugs, and the use of angiotensin-converting enzyme inhibitors or angiotensin-II-receptor antagonists declined when renal function deteriorated, from 80% to 0% and from 66% to 20% in the DK+ and DK- groups, respectively (p = 0.001). Thus, despite the use of multiple antihypertensive drugs, controlling BP - especially the systolic BP - is difficult in high-risk patients with chronic renal failure caused by diabetic kidney disease. 相似文献
83.
Minna K. Peltola Maarit A.M. Salonen Aune M. Raustia 《Cranio : the journal of craniomandibular practice》2013,31(3):210-215
Temporomandibular disorders (TMD) are common but complex problems in dentistry. Most patients can be treated using relatively simple methods, such as counselling, splint therapy, and occlusal adjustment. Patients who do not respond to conservative treatment may benefit from surgical treatment. Ninety-two patients (68 women, 24 men, mean age 36 years, range 14–74 years) were treated between 1988 and 1990 in the Department of Prosthetic Dentistry and Stomatognathic Physiology. Sixty-two patients, of which 15 were surgically treated, attended for clinical follow-up in 1994. Success of treatment was evaluated using the anamnestic and clinical dysfunction indices of Helkimo. All patients reported that they had benefitted from their treatment. Symptoms of TMD were also noted to be clinically less than before. The results of the study reported show that the effects of stomatognathic treatment are beneficial in long-term, i.e. the patients were subjectively satisfied, and symptoms recorded clinically on follow-up were statistically significantly less than before. 相似文献
84.
Thomas Eriksson Berit Lindahl Dagfinn Nden Ingegerd Bergbom 《Scandinavian journal of caring sciences》2021,35(1):319-327
There is a need to develop and use research observations in the clinical field, primarily to gain insight into and assess evidence of what comprises caring in a real‐life situation and confirm what is actually taking place. In addition, assessments lead to a new and different understanding of what caring constitutes, thereby enabling the identification of what kind of care is being provided and is required. Such observations also enable the observer to perceive and verbalise caring. There are ongoing discussions, specifically in Nordic countries, on how to use caring science‐based observations as a means of collecting and interpreting qualitative data through the application of a hermeneutic approach, which constitutes describing what has been seen and reporting on it by way of ethical obligation. This article contributes to the debate through the provision of additional content and by reflecting on the development and usability of hermeneutical research observations from a method and methodological perspective, thereby refining previous ideas and extending previous assumptions. The primary study objective was to report on the experience of utilising observations as a single data collection method for hermeneutic research with the aim of evaluating the interplay between intensive care unit (ICU) patients and their next of kin. A secondary objective was to highlight the impact of preknowledge and preunderstanding on the interpretation process. An intensive care context was assessed as the most appropriate, as the majority of patients are unable to engage in verbal narratives during ongoing treatment and care. The benefits of employing hermeneutic observation as well as interpretation and preunderstanding from a caring science perspective are considered. 相似文献
85.
86.
Aim of Study
Isolated hearts used in the study of ischemia-reperfusion induced myocardial reactive oxygen species (ROS) have typically been perfused with crystalloid buffer. Limitations of crystalloid buffer which may exaggerate the production of ROS, include a requirement for higher oxygen tension and the absence of the intrinsic erythrocyte antioxidant defenses. Using a novel recirculating blood-perfused rat heart model, we measured H2O2 concentration in the blood (as an indicator of ROS formation) and tissue glutathione concentration (an overall measure of oxidant stress) following ischemia and reperfusion.Methods
Autologous blood was obtained and the heart isolated from pentobarbital-anesthetized male Sprague-Dawley rats and placed on a recirculating perfusion circuit with an in-line peristaltic pump and oxygenator. Blood temperature was maintained at 37 °C. Hearts underwent normal perfusion for 120 min (Sham Group, n = 7) or 35 min of normal perfusion, 25 min of global ischemia, followed by 60 min of reperfusion with baseline coronary blood flow levels (IR group, n = 6). Oxygen delivery was compared with a group of buffer-perfused hearts perfused at 85 mm Hg.Results
LV function in the sham group remained stable for 2 h under normal physiologic oxygen conditions. The oxygen tension and coronary flow were significantly decreased but the myocardial oxygen delivery was significantly increased with blood perfusion compared with buffer perfusion. In the blood IR group, a significant increase in H2O2 was seen early in reperfusion and a reduction in tissue GSH was noted at the end of reperfusion.Conclusion
This model offers significant physiologic advantages in the study of ischemia and reperfusion, particularly in terms of oxygen delivery, compared with the more commonly used acellular buffer-perfused isolated heart systems. 相似文献87.
Salmonid T cells assemble in the thymus, spleen and in novel interbranchial lymphoid tissue 总被引:2,自引:0,他引:2
Koppang EO Fischer U Moore L Tranulis MA Dijkstra JM Köllner B Aune L Jirillo E Hordvik I 《Journal of anatomy》2010,217(6):728-739
In modern bony fishes, or teleost fish, the general lack of leucocyte markers has greatly hampered investigations of the anatomy of the immune system and its reactions involved in inflammatory responses. We have previously reported the cloning and sequencing of the salmon CD3 complex, molecules that are specifically expressed in T cells. Here, we generate and validate sera recognizing a peptide sequence of the CD3ε chain. Flow cytometry analysis revealed high numbers of CD3ε(+) or T cells in the thymus, gill and intestine, whereas lower numbers were detected in the head kidney, spleen and peripheral blood leucocytes. Subsequent morphological analysis showed accumulations of T cells in the thymus and spleen and in the newly discovered gill-located interbranchial lymphoid tissue. In the latter, the T cells are embedded in a meshwork of epithelial cells and in the spleen, they cluster in the white pulp surrounding ellipsoids. The anatomical organization of the salmonid thymic cortex and medulla seems to be composed of three layers consisting of a sub-epithelial medulla-like zone, an intermediate cortex-like zone and finally another cortex-like basal zone. Our study in the salmonid thymus reports a previously non-described tissue organization. In the intestinal tract, abundant T cells were found embedded in the epithelium. In non-lymphoid organs, the presence of T cells was limited. The results show that the interbranchial lymphoid tissue is quantitatively a very important site of T cell aggregation, strategically located to facilitate antigen encounter. The interbranchial lymphoid tissue has no resemblance to previously described lymphoid tissues. 相似文献
88.
Aune D Chan DS Greenwood DC Vieira AR Rosenblatt DA Vieira R Norat T 《Annals of oncology》2012,23(6):1394-1402
BackgroundEvidence from case–control studies suggest that dietary fiber may be inversely related to breast cancer risk, but it is unclear if this is supported by prospective data. We conducted a systematic review and meta-analysis of the evidence from prospective studies.MethodsPubMed was searched for prospective studies of fiber intake and breast cancer risk until 31st August 2011. Random effects models were used to estimate summary relative risks (RRs).ResultsSixteen prospective studies were included. The summary RR for the highest versus the lowest intake was 0.93 [95% confidence interval (CI) 0.89–0.98, I2 = 0%] for dietary fiber, 0.95 (95% CI 0.86–1.06, I2 = 4%) for fruit fiber, 0.99 (95% CI 0.92–1.07, I2 = 1%) for vegetable fiber, 0.96 (95% CI 0.90–1.02, I2 = 5%) for cereal fiber, 0.91 (95% CI 0.84–0.99, I2 = 7%) for soluble fiber and 0.95 (95% CI 0.89–1.02, I2 = 0%) for insoluble fiber. The summary RR per 10 g/day of dietary fiber was 0.95 (95% CI 0.91–0.98, I2 = 0%, Pheterogeneity = 0.82). In stratified analyses, the inverse association was only observed among studies with a large range (≥13 g/day) or high level of intake (≥25 g/day).ConclusionIn this meta-analysis of prospective studies, there was an inverse association between dietary fiber intake and breast cancer risk. 相似文献
89.
PURPOSE: The aim of this clinical retrospective study was to evaluate the survival and success of single metal-ceramic crowns after 20 years. The biologic and technical complications as well as patient satisfaction were recorded. MATERIALS AND METHODS: Fifty patients treated with 100 single metal-ceramic crowns attended the clinical 20-year follow-up examination. The mean follow-up time was 18.8 years (17.5 to 20.5 years). RESULTS: Twenty-one teeth with single crowns were extracted because of root fractures or esthetic or periodontal reasons. Ninety-seven percent of the subjects had no complaints about the esthetics of the crowns. The most common clinical findings were supragingival crown margins caused by gingival recessions, gingival bleeding on probing, and occlusal wear in opposing teeth. The success of the crowns after 20 years was 75%, and the survival was 78%. CONCLUSION: In the 20-year follow-up of single metal-ceramic crowns, there were few biologic and technical complications, and patients were satisfied with the crowns. Crown removal was in most cases the result of root fractures in single crowns with endodontic posts. 相似文献
90.
Eduardo De Stefani Hugo Deneo-Pellegrini Alvaro L. Ronco Paolo Boffetta Pelayo Correa Dagfinn Aune 《Nutrition and cancer》2013,65(2):294-299
The role of meat in squamous cell carcinoma of the esophagus (ESCC) has been considered conflictive. For this reason, we decided to conduct a case-control study on meat consumption and ESCC. Data included 234 newly diagnosed and microscopically examined ESCC and 2,020 controls with conditions not related to tobacco smoking nor alcohol drinking and without changes in their diets. We studied total meat, red meat, beef, lamb, processed meat, poultry, fish, total white meat, liver, fried meat, barbecued meat, boiled meat, heterocyclic amines, nitrosodimethylamine, and benzo[a]pyrene in relation with the risk of ESCC. Red meat, lamb, and boiled meat were directly associated with the risk of ESCC, whereas total white meat, poultry, fish, and liver were mainly protective against this malignancy. 相似文献