全文获取类型
收费全文 | 1869篇 |
免费 | 108篇 |
国内免费 | 1篇 |
专业分类
1978篇 |
出版年
2024年 | 7篇 |
2023年 | 47篇 |
2022年 | 31篇 |
2021年 | 51篇 |
2020年 | 33篇 |
2019年 | 32篇 |
2018年 | 82篇 |
2017年 | 73篇 |
2016年 | 92篇 |
2015年 | 55篇 |
2014年 | 92篇 |
2013年 | 153篇 |
2012年 | 111篇 |
2011年 | 155篇 |
2010年 | 90篇 |
2009年 | 71篇 |
2008年 | 102篇 |
2007年 | 94篇 |
2006年 | 97篇 |
2005年 | 76篇 |
2004年 | 89篇 |
2003年 | 110篇 |
2002年 | 58篇 |
2001年 | 40篇 |
2000年 | 53篇 |
1999年 | 31篇 |
1998年 | 5篇 |
1997年 | 12篇 |
1996年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1971年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1978条查询结果,搜索用时 15 毫秒
991.
Zoroğlu SS Yürekli M Meram I Söğüt S Tutkun H Yetkin O Sivasli E Savaş HA Yanik M Herken H Akyol O 《Cell biochemistry and function》2003,21(1):55-60
Several studies indicate that nitric oxide (NO) is involved in the aetiopathogenesis of many neuropsychiatric disorders such as schizophrenia, bipolar disorder, depression, Alzheimer's disease, Hungtington disease and stroke. Although it has not been investigated yet, several recent studies proposed that NO may have a pathophysiological role in autism. Adrenomedullin (AM), a recently discovered 52-amino acid peptide hormone, induces vasorelaxation by activating adenylate cyclase and also by stimulating NO release. AM immune reactivity is present in the brain consistent with a role as a neurotransmitter. It has been stated that NO and AM do function in the regulation of many neurodevelopmental processes. We hypothesized that NO and AM activities have been affected in autistic patients and aimed to examine these molecules. Twenty-six autistic patients and 22 healthy control subjects were included in this study. AM and total nitrite (a metabolite of NO) levels have been measured in plasma. The mean values of plasma total nitrite and AM levels in the autistic group were significantly higher than control values, respectively (p < 0.001, p = 0.028). There is no correlation between total nitrite and AM levels (r = 0.11, p = 0.31). Certainly, this subject needs much further research investigating autistic patients in earlier periods of life and with subtypes of the disorder. 相似文献
992.
Bülbül M Hisar O Beydemir S Ciftçi M Küfrevioğlu OI 《Journal of enzyme inhibition and medicinal chemistry》2003,18(4):371-375
The in vitro and in vivo inhibitory effects of 5-(3alpha, 12alpha-dihydroxy-5-beta-cholanamido)-1,3,4-thiadiazole-2-sulfonamide (1), 5-(3alpha, 7alpha, 12alpha-trihydroxy-5-beta-cholanamido)-1,3,4-thiadiazole-2-sulfonamide (2), 5-(3alpha, 7alpha, 12alpha-triacetoxy-5-beta-cholanamido)-1,3,4-thiadiazole-2-sulfonamide (3) and acetazolamide on rainbow trout (Oncorhynchus mykiss) (RT) erythrocyte carbonic anhydrase (CA) were investigated. The RT erythrocyte CA was obtained by affinity chromatography with a yield of 20.9%, a specific activity of 422.5EU/mg protein and a purification of 222.4-fold. The purity of the enzyme was confirmed by SDS-PAGE. Inhibitory effects of the sulfonamides and acetazolamide on the RT erythrocyte CA were determined using the CO2-Hydratase method in vitro and in vivo studies. From in vitro studies, it was found that all the compounds inhibited CA. The obtained I50 value for the sulfonamides (1), (2) and (3) and acetazolamide were 0.83, 0.049, 0.82 and 0.052 microM, respectively. From in vivo studies, it was observed that CA was inhibited by the sulfonamides (1), (2) and (3) and acetazolamide. 相似文献
993.
Ustündağ B Canatan H Cinkilinç N Halifeoğlu I Bahçecioğlu IH 《Cell biochemistry and function》2000,18(1):23-28
Involvement of complications is considered to be one of the major factors in the prognosis of diabetes mellitus (DM). Recent studies indicate that most diabetic complications such as nephropathy and hypertension are vascular-originated. Renin-angiotensin involvement, especially changes in ACE activity level, is considered to be a key factor since ACE converts angiotensin I to angiotensin II which is a potent vasoconstrictor and plays a vital role in the regulation of blood pressure. Our present study focused on ACE activity levels along with blood glucose and HbA(1c) levels in diabetic patients with (n=18) or without (n=25) nephropathy as compared to control subjects (n=25). Blood glucose levels were significantly higher in both diabetic groups compared to controls (p<0.001). On the other hand, compared to controls, blood HbA(1c) levels were slightly higher in DM patients without complications whereas they were significantly increased in nephropatic DM patients (p<0.001). There was a very strong increase (p<0.001) at the level of ACE activity in both of the diabetic groups (with nephropathy: 47.11+/-3.70 U l(-1); without complications: 43.72+/-2.93 U l(-1); controls: 25.15+/-2.30 U l(-1)). ACE activity levels were also significantly higher in diabetic patients with nephropathy than in type II DM patients without complication (p<0.01). Our results demonstrate that ACE activity levels are increased in diabetic patients. Additional significant increase in ACE activity levels in diabetic patients with complications such as nephropathy supports the hypothesis that ACE activity has an essential role in the development of complications in diabetes. 相似文献
994.
A costal cartilage graft is one of the most useful materials in reconstructive plastic surgery. In this article, a technique of in situ split costal cartilage graft harvesting through a small incision (2 to 3 cm) using a gouge is described. The technique used has many advantages: it is a simple technique, is easy to learn, and can be performed quickly through a small incision. By avoiding complete costal cartilage graft harvesting, the associated potential complications such as pleural perforation, chest wall deformities, long-lasting postoperative pain, and incisional scar length are reduced. This technique will be useful in selected cases for which a complete block of costal cartilage graft is not needed. 相似文献
995.
996.
997.
998.
A simple and accurate method of measuring differences in breast volume based on Archimedes' principle is described. In this method, a plastic container is placed on the breast of the patient who is lying in supine position. While the breast occupies part of the container, the remaining part is filled with water and the volume is measured. This method allows the measurement of the volume differences of asymmetric breasts and also helps the surgeon to estimate the size of the prosthesis to be used in augmentation mammaplasty. 相似文献
999.
Sleep and Biological Rhythms - This study aimed to determine the frequency of restless leg syndrome (RLS) and other sleep-related movement disorders and their effects on sleep quality in epilepsy... 相似文献
1000.
In this study, we measured environmental outdoor gamma dose rates (terrestrial and cosmic) in 204 stations across the province of Artvin. The average outdoor gamma dose rate for the province of Artvin was found to be 174.81 nGy/h. The radiological map of Artvin was drawn with the help of measured outdoor gamma dose rates. Annual effective dose equivalent and lifetime cancer risk values were figured up for the adults in Artvin province by using measured outdoor gamma dose rates. The average annual dose equivalent and excess lifetime cancer risk were 214.5 μSv/y and 7.5 × 10?4, respectively. The values acquired were compared with the similar studies done around the world. The average annual effective dose equivalent and excess lifetime cancer risk were found to be approximately three times higher than the world average. 相似文献