首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   248篇
  免费   14篇
  国内免费   7篇
  2023年   2篇
  2022年   4篇
  2021年   5篇
  2020年   4篇
  2019年   6篇
  2018年   7篇
  2017年   7篇
  2016年   12篇
  2015年   7篇
  2014年   14篇
  2013年   17篇
  2012年   13篇
  2011年   4篇
  2010年   4篇
  2009年   8篇
  2008年   14篇
  2007年   14篇
  2006年   33篇
  2005年   17篇
  2004年   21篇
  2003年   13篇
  2002年   18篇
  2001年   10篇
  2000年   7篇
  1999年   4篇
  1997年   1篇
  1992年   1篇
  1987年   1篇
  1985年   1篇
排序方式: 共有269条查询结果,搜索用时 31 毫秒
71.
72.
Recently, efforts have been focused on mitochondrial DNA changes and their relation to human cancers. Among them, a 4977 bp deletion of mitochondrial DNA, named "common deletion", has been investigated in several types of tumors, with inconsistent results. In this study, we investigated the presence of the common deletion in tissues from 25 breast, 25 colorectal and 50 thyroid tumors and in the adjacent healthy tissues from Turkish patients. Samples from healthy volunteers were also evaluated for comparison. Two PCR-based methods were used for the detection of the common deletion. First, two pairs of primers were used to amplify wild-type and deleted mtDNA. Then, a highly sensitive nested-PCR was performed, to determine low amounts of deleted genomes. By the first method, wild-type mtDNAs were observed in all samples, but a deletion was observed in only six thyroid samples, by using the nested-PCR method. In conclusion, the mitochondrial common deletion was very rare in our study group and did not appear to be not related with cancer.  相似文献   
73.
Octreotide improves burn-induced intestinal injury in the rat   总被引:3,自引:0,他引:3  
The local thermal trauma activates a number of systemic mediator cascades, e.g. a complement activation, cytokine production, resulting in a generalized sequestration and a priming of local and systemic neutrophils and macrophages. We aimed to determine the possible protective effect of octreotide (OCT), a synthetic somatostatin analogue, against burn-induced intestinal tissue damage possibly by inhibiting neutrophil infiltration. Under brief ether anaesthesia, shaved dorsum of the rats was exposed to 90 degrees C bath for 10s to induce burn injury. Rats were decapitated either 3, 24 or 72 h after burn injury. Octreotide (10 microg/kg) or saline was administered subcutaneously (s.c.) immediately after the burn injury. In the 24- and 72-h burn groups, OCT injections were repeated three times daily. In the sham group the same protocol was applied except that the dorsum was dipped in a 25 degrees C water bath for 10 s Malondialdehyde (MDA) and glutathione (GSH) levels and myeloperoxidase (MPO) activity were determined in the intestinal tissue. The results demonstrate that burn injury results in significant neutrophil accumulation, as evidenced by increases in MPO activity. The increase in MDA and the concomitant decrease in GSH levels demonstrate the role of oxidative mechanisms in burn injury. OCT may have some beneficial therapeutic effects by reducing neutrophil-dependent injury and related lipid peroxidation following burn trauma.  相似文献   
74.
75.
The use of alloplastic materials in plastic surgery has become more extensive with advancement of autogenous-tissue reconstruction techniques for the repair of defects, tissue augmentation, and the stabilization of bones. An ideal alloplastic material should be nonallergenic, noncarcinogenic, sterilizable, and easy to shape and should not cause rejection. Alloplastic material used for tissue augmentation should have a low rate of resorption and distortion. High-density porous polyethylene implants (Medpor) have been used widely and successfully for tissue augmentation. The Turkish Delight is a material composed of diced cartilage grafts wrapped in oxidized regenerated cellulose (Surgicel). Its indications are similar to those of the Medpor implant, and an additional donor site is usually not needed. Both materials are used in the same anatomical locations, especially for augmentation. Therefore, the authors evaluated the long-term stability of and suitable anatomical sites for these materials. Medpor implants or Turkish Delights were placed subperiosteally or subfascially in 10 young rabbits, and the resultant changes were evaluated 16 weeks after the operation by macroscopy and histopathology. Changes in projections were measured with an ocular micrometer. Medpor implants were neither resorbed nor distorted when placed subperiosteally or subfascially, and were highly stabilized by the surrounding tissues. Turkish Delight also enabled tissue augmentation, but had a significantly higher rate of resorption compared with the Medpor implant and was loosely bound to the surrounding tissue. The Turkish Delight was less resorbed and better fixed to adjacent tissues when placed subperiosteally than when placed subfascially.  相似文献   
76.
77.
We studied whether taurine has any regressive effect on existing atherosclerotic lesions and lipid peroxidation in rabbits fed on a high-cholesterol (HC) diet. The cholesterol, triglyceride, malondialdehyde (MDA) and diene conjugate (DC) levels, as well as the aortic histopathological findings were examined in rabbits that had been fed on a cholesterol-containing diet for 8 months [0.5% cholesterol (w/w) for 3 months and subsequently 0.25% cholesterol (w/w) for 5 months], and then for a further 4 months on a normal diet with or without taurine treatment [1% (w/v) in the drinking water]. High levels of lipid and lipid peroxide induced by the HC diet were observed to decline in the plasma, liver and aorta of atherosclerotic rabbits, as well as a slight retardation in aortic atherosclerotic lesions during the regression period. Although no significant differences in the lipid and lipid peroxide levels in the plasma and aorta were found between the regressed groups with or without the taurine treatment, the extent of atherosclerotic lesions in the aorta was less in the taurine-treated regressed group than in the non-treated regressed group. However, the liver MDA and DC levels were lower in the regressed rabbits with the taurine treatment in the non-treated group. These results indicate that the taurine treatment may accelerate the regression of cholesterol-induced atherosclerotic lesions in rabbits without having any effect on the plasma and aorta lipid and lipid peroxide levels.  相似文献   
78.
Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is the most common human enzymopathy in the world. Trace elements are important for normal hematopoiesis and can play a role in acute hemolytic anemia induced by G-6-PD deficiency. For this purpose, we studied two groups consisting of 10 male children who are G-6-PD-deficient and 12 age-matched normal male children to compare plasma and erythrocyte magnesium, manganese, zinc, and plasma calcium levels between G-6-PD-deficient and normal children. All assays were performed under normal conditions free of any oxidative attack that may result in hemolytic crisis in G-6-PD-deficient subjects. All parameters in each group did not differ significantly except for erythrocyte G-6-PD activities. These data show that plasma and erythrocyte trace element contents of G-6-PD-deficient subjects do not differ in normal conditions.  相似文献   
79.
Reactive oxygen metabolites and oxidized fatty acids are proinflammatory and are involved in the pathophysiology of atherosclerosis. Amlodipine, a unique third-generation dihydropyridine-type calcium channel blocker, seems to exert atheroprotective effects through its antioxidant properties related to its chemical structure and independent of its calcium channel-blocking effect. In this study, the interactions of amlodipine with major cellular antioxidants were investigated in order to elucidate the mechanisms underlying its atheroprotective effects. New Zealand white male rabbits were fed regular chow (group 1), chow with 1% cholesterol (group 2), regular chow plus 5 mg/kg/day amlodipine per os (group 3) and 1% cholesterol plus amlodipine (group 4) for 8 weeks. Total cholesterol, malondialdehyde (MDA) and vitamin E concentrations and catalase and superoxide dismutase (SOD) activities were determined in blood drawn before and after the experimental period. Aortic tissue was examined for atherosclerotic changes and aortic total cholesterol, MDA, catalase and SOD were determined. At the end of the 8-week treatment period, serum total cholesterol and plasma MDA were elevated in groups 2 and 4. In group 2, serum vitamin E and plasma SOD diminished (p < 0.05) and catalase increased (p < 0.05). In group 4, SOD activity increased at the end of treatment. MDA levels were lower and plasma SOD activities were higher in group 4 than in group 2. Aortic tissue investigations revealed higher total cholesterol and MDA concentrations and catalase activities in group 2 than in group 4, and the highest tissue SOD activity was recorded in group 4 (p < 0.05 for all comparisons). Morphological examination of aortic tissues exhibited endothelial disarrangement and lipid deposition in group 2. Histopathological alterations related to atherogenesis were less in group 4 than in group 2. Amlodipine seems to exert atheroprotective effects by reducing aortic cholesterol accumulation and blood and aortic lipid peroxidation, enhancing SOD activity both in blood and aortic tissue and suppressing the consumption of vitamin E. On the other hand, the suppression of catalase activity in blood and the aorta interferes with the drug's well-known antioxidant effects.  相似文献   
80.
Ozdemir R  Kilinç H  Unlü RE  Uysal AC  Sensöz O  Baran CN 《Plastic and reconstructive surgery》2002,110(4):1134-47; discussion 1148-9
Plastic surgeons have sought to improve nasolabial folds, jowls, jaw lines, and cervical contour with face-lifting procedures that are abundant in the literature. The retaining ligaments of the face support facial soft tissue in normal anatomic position, resisting gravitational change. As this ligamentous system attenuates, facial fat descends into the plane between the superficial and deep facial fascia, and the stigmata of facial age develop. In this study, surgical correction of the retaining ligaments and plication of the superficial musculoaponeurotic system (SMAS) to reposition the structures that have descended with gravitation are discussed. The anatomy of the facial retaining ligaments was studied in 22 half-faces of 11 fresh cadavers, and the localization, extension, and width of the ligaments were examined macroscopically and histologically. Surgical correction of the retaining ligaments and plication of the SMAS have been accomplished in 27 face-lift patients with this anatomicohistologic study taken into consideration. There was hematoma in one patient at the cheek region and a permanent dimple caused by postoperative edema in two patients, with a localization of one zygomatic and two parotidomasseteric ligaments. In one patient, hypesthesia in the mandibular nerve region was seen, which remitted at 14 weeks. There were no other complications, and with a follow-up of 24 months, excellent aesthetic results and a high level of patient satisfaction were encountered.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号