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排序方式: 共有97条查询结果,搜索用时 15 毫秒
41.
Cruchaga C Haller G Chakraverty S Mayo K Vallania FL Mitra RD Faber K Williamson J Bird T Diaz-Arrastia R Foroud TM Boeve BF Graff-Radford NR St Jean P Lawson M Ehm MG Mayeux R Goate AM;NIA-LOAD/NCRAD Family Study Consortium 《PloS one》2012,7(2):e31039
Pathogenic mutations in APP, PSEN1, PSEN2, MAPT and GRN have previously been linked to familial early onset forms of dementia. Mutation screening in these genes has been performed in either very small series or in single families with late onset AD (LOAD). Similarly, studies in single families have reported mutations in MAPT and GRN associated with clinical AD but no systematic screen of a large dataset has been performed to determine how frequently this occurs. We report sequence data for 439 probands from late-onset AD families with a history of four or more affected individuals. Sixty sequenced individuals (13.7%) carried a novel or pathogenic mutation. Eight pathogenic variants, (one each in APP and MAPT, two in PSEN1 and four in GRN) three of which are novel, were found in 14 samples. Thirteen additional variants, present in 23 families, did not segregate with disease, but the frequency of these variants is higher in AD cases than controls, indicating that these variants may also modify risk for disease. The frequency of rare variants in these genes in this series is significantly higher than in the 1,000 genome project (p = 5.09×10−5; OR = 2.21; 95%CI = 1.49–3.28) or an unselected population of 12,481 samples (p = 6.82×10−5; OR = 2.19; 95%CI = 1.347–3.26). Rare coding variants in APP, PSEN1 and PSEN2, increase risk for or cause late onset AD. The presence of variants in these genes in LOAD and early-onset AD demonstrates that factors other than the mutation can impact the age at onset and penetrance of at least some variants associated with AD. MAPT and GRN mutations can be found in clinical series of AD most likely due to misdiagnosis. This study clearly demonstrates that rare variants in these genes could explain an important proportion of genetic heritability of AD, which is not detected by GWAS. 相似文献
42.
Ekwere T Ifon Alan LY Pang Warren Johnson Kathleen Cashman Sharon Zimmerman Sumitra Muralidhar Wai-Yee Chan John Casey Leonard Jason Rosenthal 《Cancer cell international》2005,5(1):19
Background
Insensitivity of advanced-stage prostate cancer to androgen ablation therapy is a serious problem in clinical practice because it is associated with aggressive progression and poor prognosis. Targeted therapeutic drug discovery efforts are thwarted by lack of adequate knowledge of gene(s) associated with prostate tumorigenesis. Therefore there is the need for studies to provide leads to targeted intervention measures. Here we propose that stable expression of U94, a tumor suppressor gene encoded by human herpesvirus 6A (HHV-6A), could alter gene expression and thereby inhibit the tumorigenicity of PC3 cell line. Microarray gene expression profiling on U94 recombinant PC3 cell line could reveal genes that would elucidate prostate cancer biology, and hopefully identify potential therapeutic targets. 相似文献43.
Callus cultures were raised from bulb scale segments ofOrinthogalum umbellatum L. (Liliaceae), on a Murashige and Skoog (1962) medium (MS) with 8 mg/l naphthaleneacetic acid (NAA). Bulbous shoots developed from calli after 2 months using MS medium with 2 mg/l NAA and 0.5 mg/l N6 - benzyladenine (BA). Shoots were also induced directly from scales of regenerated bulb used as secondary explants on MS medium supplemented with 0.5 mg/l BA. Shoots developed roots in 1/2 - strength MS medium. Regenerants multiplied rapidly in 1/2-MS liquid medium. Chromosome instability was reduced in callus grown on 2 mg/l NAA compared to callus grown on 8 mg/l NAA. Callus retained regeneration potential for 5 years in this modified MS medium. The chromosome analysis of regenerants dervied from callus, even from long term culture of 5 years, revealed only diploid cells with normal karyotype comprising 2n=46 chromosomes. Stable nature of callus and regenerants were further confirmed by cytophotometry. This procedure can be applied for securing stable regenerants on a mass scale inO. umbellatum. 相似文献
44.
Background
Breast cancer cells frequently metastasize to the skeleton and induce extensive bone destruction. Cancer cells produce proteinases, including matrix metalloproteinases (MMPs) and the plasminogen activator system (PAS) which promote invasion of extracellular matrices, but whether these proteinases degrade bone matrix is unclear. To characterize the role that breast cancer cell proteinases play in bone degradation we compared the effects of three human breast cancer cell lines, MDA-MB-231, ZR-75-1 and MCF-7 with those of a normal breast epithelial cell line, HME. The cell lines were cultured atop radiolabelled matrices of either mineralized or non-mineralized bone or type I collagen, the principal organic constituent of bone. 相似文献45.
Kishalay Bhar Sumitra Das Georgina Rosair Barindra Kumar Ghosh 《Inorganica chimica acta》2010,363(13):3308-8587
Two hexacoordinated dinuclear compounds [Mn(L1)(dca)]2(ClO4/PF6)2·CH3OH (1/2) and two heptacoordinated coordination polymers [Mn(L2)(dca)]n(ClO4/PF6)n (3/4) [L1 = N,N′-(bis-(pyridin-2-yl)benzylidene)-1,3-propanediamine; L2 = N,N′-(bis-(pyridin-2-yl)benzylidene)diethylenetriamine; dca = dicyanamide] are synthesized and characterized. Structures of 1-3 have been solved by X-ray diffraction measurements. Each manganese(II) center in 1/2 is located in a distorted octahedral environment with an MnN6 chromophore coordinated by the four N atoms of L1 and two nitrile N atoms of bibridged μ1,5 dca. Interestingly, the coordination polymer 3 forms a 1D chain through single Mn-(NCNCN)-Mn units in which each manganese(II) center adopts a pentagonal bipyramidal geometry with an MnN7 chromophore occupied with five N atoms of L2 and two nitrile N atoms of monobridged μ1,5 dca. Magnetic susceptibility measurements of 1-3 in the 2-300 K temperature range reveal weak antiferromagnetic interactions. 相似文献
46.
47.
Murashige and Skoog's medium with 2, 4-D and kinetin induced callus in the shoot segments of Asparagus racemosus. Regeneration of shoot buds and clonal multiplication of excised shoots through proliferation of nodal buds could be achieved by the use of IAA and BAP in the medium. Rooting was achieved with half strength MS basal medium plus IBA. Complete plants with cladode, crown and root systems were developed in hormone free medium. The plants were successfully transferred to soil. 相似文献
48.
Experimental myocardial necrosis in rats: Role of arjunolic acid on platelet aggregation,coagulation and antioxidant status 总被引:6,自引:0,他引:6
Sumitra Miriyala Manikandan Panchatcharam Kumar Dilly Ashok Arutselvan Natarajan Balakrishna Kedike Manohar Bhakthavatsalam Murali Puvanakrishnan Rengarajulu 《Molecular and cellular biochemistry》2001,224(1-2):135-142
Arjunolic acid, a new triterpene and a potent principle from the bark of Terminalia arjuna, has been shown to provide significant cardiac protection in isoproterenol induced myocardial necrosis in rats. To further explore the mechanism of action of arjunolic acid, antiplatelet activity, anticoagulant assays, electrocardiographic changes, serum marker enzymes, antioxidant status, lipid peroxide and myeloperoxidase (MPO) have been measured and the results are compared with a potent cardioprotective drug, acetyl salicylic acid (ASA). Administration of isoproterenol produces electrocardiographic changes such as decreased R amplitude and increased ST segment elevation and has resulted in an increase in serum marker enzyme levels as well as a decrease in enzymatic and nonenzymatic antioxidant levels. Arjunolic acid at an effective dosage of 15 mg/kg body weight (pre and post treatment),when administered intraperitoneally (i.p.), effects a decrease in serum enzyme levels and the electrocardiographic changes get restored towards normalcy. Arjunolic acid treatment is also shown to prevent the decrease in the levels of superoxide dismutase, catalase, glutathione peroxidase, ceruloplasmin, -tocopherol, reduced glutathione (GSH), ascorbic acid, lipid peroxide, MPO and the cardioprotection is confirmed by the histopathological studies.This study shows that the cardioprotection of arjunolic acid pre and post treatment could possibly be due to the protective effect against the damage caused by myocardial necrosis. 相似文献
49.
We investigated the effect of salinity on the development of seedlings of Vigna unguiculata. At various time intervals, the
hypocotyls were measured to estimate the effect of salt concentration on growth parameters. Control plants were tallest and
had the greatest fresh weights, whereas these values were lowest in seedlings treated with high levels of salt. Three hydrogen
donors -- caffeic acid, ferulic acid, and pyrogalol - were studied to determine the changes in peroxidase activity for both
cytoplasmic and wall-bound fractions. Activity was inversely correlated with hypocotyl elongation. A clear concentration effect
was also observed for contents of pectic polysaccharides, low-molecular-weight xyloglucan, and high-molecular-weight xyloglucan,
with control seedlings showing lower levels of those wall components than that recorded in the salt-treated seedlings. Here,
we also discuss the role of peroxidase and wall components in hypocotyl elongation and growth ofVigna when seedlings undergo saline stress. 相似文献
50.
John Hayslip Emily V. Dressler Heidi Weiss Tammy J. Taylor Mara Chambers Teresa Noel Sumitra Miriyala Jeriel T. R. Keeney Xiaojia Ren Rukhsana Sultana Mary Vore D. Allan Butterfield Daret St Clair Jeffrey A. Moscow 《PloS one》2015,10(4)