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   55篇
  免费   3篇
  2024年   1篇
  2023年   2篇
  2021年   1篇
  2020年   1篇
  2019年   3篇
  2016年   1篇
  2015年   1篇
  2014年   1篇
  2013年   5篇
  2012年   5篇
  2011年   9篇
  2010年   4篇
  2009年   3篇
  2008年   2篇
  2007年   3篇
  2006年   1篇
  2005年   2篇
  2004年   1篇
  2003年   2篇
  2002年   1篇
  2000年   2篇
  1999年   1篇
  1995年   1篇
  1992年   3篇
  1973年   1篇
  1971年   1篇
排序方式: 共有58条查询结果,搜索用时 31 毫秒
41.
42.
A series of novel pyrazole integrated benzophenones (9aj) have been designed, synthesized from 1-methyl-5-(2,4,6-trimethoxy-phenyl)-1H-pyrazole 6. The structures of the regioisomers 6 and 7 were determined by 2D 1H–1H COSY, 1H–13C HSQC and 1H–13C HMBC experiments. The newly synthesized compounds (9aj) were evaluated for in vivo anti-inflammatory activity by carrageenan paw edema in rats and in vitro COX-1/COX-2 inhibition and antioxidant potential. Among the synthesized compounds, compounds 9b, 9d and 9f, were found to be active anti-inflammatory agents in addition to having potent antioxidant activity.  相似文献   
43.
Graft copolymer of xanthan gum (XG) and ethylacrylate (EA) has been synthesized by free radical polymerization using potassium peroxydisulfate (KPS) as an initiator in an air atmosphere. The grafting parameters, i.e. grafting ratio and efficiency decrease with increase in concentration of xanthan gum from 0.050 mg/25 mL to 0.350 mg/25 mL, but these grafting parameters increase with increase in concentration of ethylacrylate from 9 × 10−2 to 17 × 10−2 ML−1, and KPS from 15 × 10−3 to 35 × 10−3 ML−1. The graft copolymer has been characterized by FTIR, XRD, TGA and SEM analysis. The grafted copolymer was also evaluated as efficient Zn2+ metal binder. The grafted copolymer shows improvement in the stability, solubility as well as their sorbing capacity. Thus graft copolymer formed could find applications in metal ion removal and in drug delivery.  相似文献   
44.
Probiotics and prebiotics, which can change the colonic microenvironment, are the areas of current interest. Unutilizable fractions of the foods and fortificants, which reach the colon can affect the profile of probiotics. Effects of eight such factors viz. zinc sulphate, zinc carbonate, ferrous sulphate, ferric citrate, quercetin, gallic acid, phytic acid, and oxalic acid were, therefore, investigated on 24 H growth of Lactobacillus acidophilus (L1) and Lactobacillus plantarum (L2), two isolates of bifidobacteria (longum (L3) and bifidum (L4)) and a marketed consortium (L5) of eight probiotic cultures. MRS medium with marketed fructooligosaccharide as the only source of carbon was used for study of dose response curves. Quercetin and zinc sulphate showed significant positive effect for L1 and L5 (P < 0.01), whereas there was slight positive effect or no effect on growth of other probiotics. Phytic acid showed a significant inhibitory effect for L2 and a slight inhibitory effect on L3 and L4 whereas L5 were able to tolerate phytic acid. Oxalic acid had slight positive effect for L1 (P < 0.05) and L5 and no effect on growth of other probiotics (P > 0.05). Further, zinc sulphate, ferrous sulphate, quercetin, and oxalic acid significantly inhibited growth of E. coli (P < 0.05)  相似文献   
45.
46.
Cisgenic engineering involves isolation and modification of genetic elements from the host genome, which are reinserted to develop plant varieties with improved characteristics. As a first step toward production of fungal-disease resistant cisgenic grapevines, the Vitis vinifera thaumatin-like protein (vvtl-1) gene was isolated from “Chardonnay” and reengineered for constitutive expression. Embryogenic cultures of “Thompson Seedless” were initiated from leaves and transformed with Agrobacterium to regenerate cisgenic VVTL-1 plants. Cisgene presence and copy number were confirmed by PCR and quantitative real-time PCR. Protein expression was measured using ELISA. Among the plant lines tested, two exhibited a 7–10 day delay in powdery mildew disease development during greenhouse screening and decreased severity of black rot disease in field tests. Berries exhibited a 42.5% reduction in sour-bunch rot disease incidence compared to non-transformed controls after 3 wk of storage at room temperature. Although plants recovered in this study contain viral promoters and reporter/marker genes, this is the first report of a cisgenic approach to obtain broad-spectrum fungal-disease resistance in genetically engineered grapevine.  相似文献   
47.
The formation of human islet amyloid polypeptide (hIAPP) is implicated in the loss of pancreatic β-cells in type II diabetes. Rat amylin, which differs from human amylin at six residues, does not lead to formation of amyloid fibrils. Pramlintide is a synthetic analog of human amylin that shares three proline substitutions with rat amylin. Pramlintide has a much smaller propensity to form amyloid aggregates and has been widely prescribed in amylin replacement treatment. It is known that the three prolines attenuate β-sheet formation. However, the detailed effects of these proline substitutions on full-length hIAPP remain poorly understood. In this work, we use molecular simulations and bias-exchange metadynamics to investigate the effect of proline substitutions on the conformation of the hIAPP monomer. Our results demonstrate that hIAPP can adopt various β-sheet conformations, some of which have been reported in experiments. The proline substitutions perturb the formation of long β-sheets and reduce their stability. More importantly, we find that all three proline substitutions of pramlintide are required to inhibit β conformations and stabilize the α-helical conformation. Fewer substitutions do not have a significant inhibiting effect.  相似文献   
48.
49.
A novel series of 3-(substituted)-aryl-5-(9-methyl-3-carbazole)-1H-2-pyrazolines (5a-o) has been synthesized and the structures of newly synthesized compounds were characterized by IR, (1)H NMR and mass spectral analysis. All the synthesized compounds were evaluated for their in vitro and in vivo anti-inflammatory activity, and also for their antioxidant activity. Compounds 5b, 5c, 5d and 5n were found to be selective COX-2 inhibitors. Compound 5c was found to potent inhibitor of the carrageenin induced paw edema in rats. Most of the compounds exhibited good DPPH and superoxide radical scavenging activity, while compounds 5c, 5d, 5i and 5k exhibited good hydroxyl radical scavenging activity. Molecular docking result, along with the biological assay data, suggested that compound 5c was a potential anti-inflammatory agent.  相似文献   
50.
In this paper the behavior of the Asiatic lion was studied during natural and gonadotropin-induced estrus in relation to fecal estradiol and progesterone concentration. The average length of estrus was 5.4 days and no significant difference was observed between natural and gonadotropin-induced estrus. Vocalization and rolling were the major estrus behavioral activities of Asiatic lions and the frequency of these activities were similar in both natural and gonadotropin-induced estrus and treatment with exogenous gonadotropin did not alter estrus behavioral activities. A significant positive correlation was observed between fecal estradiol and frequency of estrus behavior during natural and gonadotropin-induced estrus. Following gonadotropin treatment estrus could be induced in 69% of animals and these induced animals ovulated following hCG treatment. This study reports for the first time the successful use of the non-invasive fecal steroid assay for monitoring the induction of estrus and ovulation in the Asiatic lion.  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