全文获取类型
收费全文 | 367篇 |
免费 | 28篇 |
国内免费 | 24篇 |
专业分类
儿科学 | 19篇 |
妇产科学 | 8篇 |
基础医学 | 35篇 |
口腔科学 | 9篇 |
临床医学 | 44篇 |
内科学 | 114篇 |
皮肤病学 | 30篇 |
神经病学 | 9篇 |
特种医学 | 70篇 |
外科学 | 12篇 |
综合类 | 17篇 |
预防医学 | 5篇 |
药学 | 31篇 |
肿瘤学 | 16篇 |
出版年
2023年 | 2篇 |
2021年 | 2篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 11篇 |
2014年 | 7篇 |
2013年 | 11篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 12篇 |
2009年 | 17篇 |
2008年 | 14篇 |
2007年 | 22篇 |
2006年 | 13篇 |
2005年 | 17篇 |
2004年 | 10篇 |
2003年 | 11篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 21篇 |
1997年 | 15篇 |
1996年 | 28篇 |
1995年 | 8篇 |
1994年 | 18篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 14篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 3篇 |
排序方式: 共有419条查询结果,搜索用时 15 毫秒
411.
JA Povlsen B Løfgren LE Rasmussen JM Nielsen R Nørregaard SB Kristiansen HE Bøtker TT Nielsen 《Clinical and experimental pharmacology & physiology》2009,36(9):892-898
- 1 Because diabetic hearts have an increased threshold for cardioprotection by ischaemic preconditioning (IPC), we hypothesized that protection by l ‐glutamate during reperfusion is restricted in Type 2 diabetic hearts. Previously, we found that l ‐glutamate‐mediated postischaemic cardioprotection mimics IPC.
- 2 Rat hearts were studied in a Langendorff preparation perfused with Krebs’–Henseleit solution and subjected to 40 min global no‐flow ischaemia, followed by 120 min reperfusion. l ‐Glutamate (0, 15 and 30 mmol/L) was added to the perfusate during reperfusion of hearts from non‐diabetic (Wistar‐Kyoto) and diabetic (Zucker diabetic fatty (ZDF)) rats, studied at 16 weeks of age. The infarct size (IS)/area‐at‐risk (AAR) ratio was the primary end‐point. Expression of l ‐glutamate excitatory amino acid transporter (EAAT) 1 (mitochondrial) and EAAT3 (sarcolemmal) was determined by quantitative polymerase chain reaction and immunoblotting.
- 3 The ISS/AAR ratio did not differ between control hearts from Wistar‐Kyoto and ZDF rats (0.52 ± 0.03 and 0.51 ± 0.04, respectively; P = 0.90). l ‐Glutamate (15 mmol/L) significantly reduced the IS/AAR ratio in non‐diabetic hearts, but not in diabetic hearts, compared with their respective controls. The higher concentration of l ‐glutamate (30 mmol/L) reduced infarct size in diabetic hearts to the same degree as in non‐diabetic hearts (IS/AAR 0.35 ± 0.03 (P = 0.002) and 0.34 ± 0.03 (P = 0.004), respectively). The mitochondrial l ‐glutamate transporter EAAT1 was downregulated in hearts from ZDF rats at both the mRNA and protein levels (P < 0.0005 and P < 0.0001, respectively). However, there was no change in EAAT3 expression at the protein level. Myocardial l ‐glutamate content was increased by 43% in diabetic hearts (P < 0.0001).
- 4 Hearts from obese diabetic rats have an elevated threshold for metabolic postischaemic cardioprotection by l ‐glutamate. These findings may reflect underlying mechanisms of inherent resistance against additional cardioprotection in the diabetic heart.
412.
413.
Regulation of hematopoiesis II: the role of polyamine inhibition on helper or suppressor influences of the thymus 总被引:1,自引:0,他引:1
We have previously suggested in murine model systems, that two cell subpopulations with differing proliferative capacity, from the thymus, modify the growth of erythroid progenitor cells in vitro. In order to further characterize these populations, we have specifically inhibited polyamine biosynthesis; this pathway is essential for the process of cell replication. Thus, alpha-difluoromethyl ornithine (DFMO) was used to block the conversion of ornithine to putrescine, the first and rate- limiting step in polyamine biosynthesis. We observed a threefold increase in hematopoietic progenitors (CFU-S and CFU-E) from bone marrow in animals treated with DFMO. We further examined the effect of DFMO on accessory "helper" and "suppressor" cells from the thymus and observed an increase in helper activity with an elimination of suppressor activity. All of these effects of DFMO were specific for inhibition of polyamine biosynthesis, since simultaneous addition of the depleted biosynthetic product, putrescine, restored suppressor activity. We conclude that polyamine biosynthesis is required acutely for accessory cell regulation of hematopoiesis. 相似文献
414.
415.
Background: Dentinal hypersensitivity has been defined as a short, sharp pain arising from exposed dentine as a result of various stimuli such as heat, cold, chemical, or osmotic, that cannot be ascribed to any other pathology. This study was conducted to assess the efficacy of three commercially available toothpastes in the reduction of dentinal hypersensitivity. Methods: A total of 149 subjects (72 males and 77 females; aged 20 to 60 years) were entered into the study and randomly divided into four groups: Group 1 – toothpaste containing 5% potassium nitrate; Group 2 – toothpaste containing 5% calcium sodium phosphosilicate with fused silica; Group 3 – toothpaste containing 3.85% amine fluoride; and Group 4 – a placebo toothpaste. After sensitivity scores for controlled air stimulus and cold water at baseline were recorded, subjects were given toothpastes and sensitivity scores were measured again at 2 weeks and 6 weeks. Results: All groups showed a reduction in sensitivity scores at 2 weeks and 6 weeks. The calcium sodium phosphosilicate group was found to be significantly better compared to the other groups at the end of 6 weeks. Conclusions: The calcium sodium phosphosilicate group showed a better reduction in the symptoms of dentinal hypersensitivity. 相似文献
416.
Background
The neonatal line (NL) is an important issue in forensic odontology. It is the sign of a developmental birth defect, which is caused by the effect of metabolic stress on tooth structures when the fetus passes to extrauterine life.Aims
The aim of this research is to determine the existence and thickness of NL in teeth, as it is a legal necessity to indicate the signs of viability at birth in a forensic examination of a fetus or infant case.Study design and subjects
This research was conducted on 48 lower left and right lateral teeth, which were taken from 24 autopsy cases (46% female and 54% male). Left lateral teeth were sectioned in a vertical plane and right lateral teeth were sectioned in a horizontal plane. The NL thickness was measured with a scanning electron microscope (SEM). These cases comprised three conditions as: 70.3% normal birth, 16.7% caesarean sections, and 12.5% still birth cases under the legal and ethical permission.Outcome measures
The mean NL thickness of normal birth cases was higher than caesarean cases as 7.7 μm and 2.5 μm, respectively.Results and conclusions
The results showed a statistical significance between all birth conditions. NL does not exist in still birth cases (p < 0.001). Not only is the presence of NL a sign of live birth, but also its thickness is an indicator of the delivery mode where NL thickness of normal birth was found thicker than the caesarean cases. 相似文献417.
Erdil A Kilciler G Ates Y Tuzun A Gulsen M Karaeren N Dagalp K 《Internal medicine (Tokyo, Japan)》2008,47(7):613-615
A 55-year-old hemiplegic woman with percutaneous endoscopic gastrostomy (PEG) was referred to our clinic for upper gastrointestinal system bleeding and for a high level of cholestatic enzymes. She had a medical history of cerebra vascular accident three years previously and cholecystectomy one year previously. We performed gastroscopy and saw a retained surgical sponge in the bulbus. After removal of the gossypiboma, endoscopic sclerotherapy was performed for the bleeding area at the bulbus. After the procedure, the upper gastrointestinal bleeding stopped and the high level of cholestatic enzymes returned to normal. 相似文献
418.
Background
Erectile Dysfunction (ED) is one of the major social problems causing significant distress in men. Despite the increasing difficulty in management, knowledge, and understanding of factors responsible for its development are important for prevention and care.Objectives
To assess the prevalence and risk factors for ED among men in Niger Delta Region of Nigeria, in order to determine its contextual variables.Methods
Subjects included 400 male patients attending the general outpatients'' clinic (GOPC) of the University of Uyo Teaching Hospital. Respondents completed the abridged version of the International Index of Erectile Function (IIEF-5).Results
A total of 166 (41.5%) subjects had ED; 66 (16.5%) had mild; 32 (8.0%) mild to moderate; 24 (6.0%) moderate; while 45 (11.3%) had severe 37 (9.2%) resulted from hypertension and its medications; 29 (7.3%) from diabetes; 49 (12.2%) from a combination of both and their therapies (P=0.044); 24 (6.0%) had history of previous surgery; while for 27 (6.8%) it was from undiagnosed medical conditions (p=0.001). The ED increases with age and is more among married and educated men.Conclusion
ED is a common problem among men in Niger Delta region. Therefore, efforts must be made to reduce the incidence by dealing with the factors responsible for its development. 相似文献419.