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   23篇
  免费   0篇
  2017年   3篇
  2015年   2篇
  2014年   1篇
  2013年   1篇
  2011年   2篇
  2009年   1篇
  2008年   1篇
  2007年   1篇
  2005年   1篇
  2004年   3篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1992年   1篇
  1988年   1篇
  1964年   1篇
排序方式: 共有23条查询结果,搜索用时 46 毫秒
11.
The endothelin axis and in particular the two receptor subtypes, ETA and ETB, are under investigation for the treatment of various diseases such as pulmonary arterial hypertension, fibrosis, renal failure and cancer. Previous work in our lab has shown that 1,3,6-trisubstituted-4-oxo-1,4-dihydroquinoline-2-carboxylic acid derivatives exhibit noteworthy endothelin receptor antagonist activity. A series of analogues with modifications centered around position 6 of the heterocyclic quinolone core and replacement of the aryl carboxylic acid group with an isosteric tetrazole ring was designed and synthesized to further optimize the structure activity relationship. The endothelin receptor antagonist activity was determined by in vitro Förster resonance energy transfer (FRET) using GeneBLAzer® assay technology. The most potent member of this series exhibited ETA receptor antagonist activity in the subnanomolar range with an IC50 value of 0.8 nM, and was 1000-fold selective for the ETA receptor compared to the ETB receptor. Its activity and selectivity profile resembles that of the most recently approved drug, macitentan.  相似文献   
12.
A series of thirty two anilinopyrimidines derived from WZ4002 has been synthesized and evaluated for percentage inhibition of six different EGFR kinases using LanthaScreen binding assay method (EGFR d746 – 750) or Z’LYTE assay method (EGFR-WT, EGFR d746 – 750, EGFR T790M, EGFR T790M L858R, EGFR C797S and EGFR T790M L858R C797S). Ortho-hydroxyacetamide 10 exhibited complete inhibition of all the six kinases at 10 µM. Against the triple mutant, EGFR T790M C797S L858R, compounds 912 exhibited complete inhibition at 10 µM and nearly complete inhibition at 1 µM. The target compounds were also evaluated using the MTT assay to determine their cytotoxic activity against human non-small cell lung cancer cells (PC9, PC9GR and H460) and mouse leukemic cells (Ba/F3 WT and Ba/F3T 3151). Overall, 7, 912, 30 and 31 were found to be the most potent compounds across all five cell lines.  相似文献   
13.
To determine whether male- or female-biased mutation rates have affected the molecular evolution of Drosophila melanogaster and D. simulans, we calculated the male-to-female ratio of germline cell divisions ([symbol: see text]) from germline generation data and the male-to-female ratio of mutation rate ([symbol: see text]) by comparing chromosomal levels of nucleotide divergence. We found that the ratio of germline cell divisions changes from indicating a weak female bias to indicating a weak male bias as the age of reproduction increases. The range of [symbol: see text] values that we observed, however, does not lead us to expect much, if any, difference in mutation rate between the sexes. Silent and intron nucleotide divergence were compared between nine loci on the X chromosome and nine loci on the second and third chromosomes. The average levels of nucleotide divergence were not significantly different across the chromosomes, although both silent and intron sites show a trend toward slightly more divergence on the X. These results indicate a lack of sex- or chromosome-biased molecular evolution in D. melanogaster and D. simulans.   相似文献   
14.
15.
Breast cancer resistant protein (BCRP/ABCG2), a 72 kDa plasma membrane transporter protein is a member of ABC transporter superfamily. Increased expression of BCRP causes increased efflux and therefore, reduced intracellular accumulation of many unrelated chemotherapeutic agents leading to multidrug resistance (MDR). A series of 31 benzamide and phenyltetrazole derivatives with amide and urea linkers has been synthesized to serve as potential BCRP inhibitors in order to overcome BCRP-mediated MDR. The target derivatives were tested for their cytotoxicity and reversal effects in human non-small cell lung cancer cell line H460 and mitoxantrone resistant cell line H460/MX20 using the MTT assay. In the benzamide series, compounds 6 and 7 exhibited a fold resistance of 1.51 and 1.62, respectively at 10 µM concentration which is similar to that of FTC, a known BCRP inhibitor. Compounds 27 and 31 were the most potent analogues in the phenyltetrazole series with amide linker with a fold resistance of 1.39 and 1.32, respectively at 10 µM concentration. For the phenyltetrazole series with urea linker, 38 exhibited a fold resistance of 1.51 which is similar than that of FTC and is the most potent compound in this series. The target compounds did not exhibit reversal effect in P-gp overexpressing resistant cell line SW620/Ad300 suggesting that they are selective BCRP inhibitors.  相似文献   
16.

Background

Glioblastoma is a complex multifactorial disorder that has swift and devastating consequences. Few genes have been consistently identified as prognostic biomarkers of glioblastoma survival. The goal of this study was to identify general and clinical-dependent biomarker genes and biological processes of three complementary events: lifetime, overall and progression-free glioblastoma survival.

Methods

A novel analytical strategy was developed to identify general associations between the biomarkers and glioblastoma, and associations that depend on cohort groups, such as race, gender, and therapy. Gene network inference, cross-validation and functional analyses further supported the identified biomarkers.

Results

A total of 61, 47 and 60 gene expression profiles were significantly associated with lifetime, overall, and progression-free survival, respectively. The vast majority of these genes have been previously reported to be associated with glioblastoma (35, 24, and 35 genes, respectively) or with other cancers (10, 19, and 15 genes, respectively) and the rest (16, 4, and 10 genes, respectively) are novel associations. Pik3r1, E2f3, Akr1c3, Csf1, Jag2, Plcg1, Rpl37a, Sod2, Topors, Hras, Mdm2, Camk2g, Fstl1, Il13ra1, Mtap and Tp53 were associated with multiple survival events. Most genes (from 90 to 96%) were associated with survival in a general or cohort-independent manner and thus the same trend is observed across all clinical levels studied. The most extreme associations between profiles and survival were observed for Syne1, Pdcd4, Ighg1, Tgfa, Pla2g7, and Paics. Several genes were found to have a cohort-dependent association with survival and these associations are the basis for individualized prognostic and gene-based therapies. C2, Egfr, Prkcb, Igf2bp3, and Gdf10 had gender-dependent associations; Sox10, Rps20, Rab31, and Vav3 had race-dependent associations; Chi3l1, Prkcb, Polr2d, and Apool had therapy-dependent associations. Biological processes associated glioblastoma survival included morphogenesis, cell cycle, aging, response to stimuli, and programmed cell death.

Conclusions

Known biomarkers of glioblastoma survival were confirmed, and new general and clinical-dependent gene profiles were uncovered. The comparison of biomarkers across glioblastoma phases and functional analyses offered insights into the role of genes. These findings support the development of more accurate and personalized prognostic tools and gene-based therapies that improve the survival and quality of life of individuals afflicted by glioblastoma multiforme.  相似文献   
17.
N-[(R,R)-(E)-(3,4-dichlorobenzyl)-3-(2-oxoazepan-3-yl)carbamoyl]allyl-N-methyl-3,5-bis(trifluoromethyl)benzamide (DNK333, 1b) has been reported to be a potent and balanced dual neurokinin (tachykinin) receptor antagonist. A recent clinical trial using DNK333 has shown that it blocks the NKA-induced bronchoconstriction in patients with asthma. A series of six analogues 3-8 derived from modification of 3,5-bis(trifluoromethyl)benzamide moiety of DNK333 has been synthesized to serve as the dual NK(1)/NK(2) receptor probes. The 3,5-dinitro substituted benzamide compound 3 was found to possess potent and balanced dual NK(1)/NK(2) receptor antagonist activities (pK(b)=8.4 for the NK(1) receptors, pK(b)=7.87 for the NK(2) receptors) in the functional assay using guinea pig trachea. Furthermore, SAR analysis suggests that steric, electronic, and lipophilic characteristics of substituents in the benzamide region of DNK333 have a crucial effect on both the NK(1) and NK(2) receptor antagonist activities.  相似文献   
18.
19.
Так как от остатков гомогенизированных клеток легко отделить растительные вирусы (Steere и Qckers, 1962; ?ech, 1962) и митохондрии (Hjertén, 1962), мы сделали попытку использовать этот простой метод и для отделения рибосом. Надосадок гомогената растущих клеток Bacillus megaterium 110 наносили на столбец 3% гранулированного агара (Polson, 1961) и промывали 66 мл буферного раствора Tris (pH 7,72, 0,005 M с 0,01 M?MgCl2) в течение часа при комнатной температуре. В элюате определяли абсорбцию при 260 мμ и белки (рис. 1). При ультрацентрифугировании образца были обнаружены рибосомы с S 20 0 107, 71, 5, 45 и 30S (рис. 2). Ультрацентрифугированием фракции № 10 были с помощью адсорбции в УФ лучах найдены рибосомы с s 20 0 107 и 44,6S (рис. 3). Группа 100S перекрывалась абсорбцией рибосом 70S, группа 30 не была обнаружена. Отделение рибосом как самостоятельной вершины не было получено. Однако, судя по соотношению нуклеиновых кислот и белков во главе вымываемой плазмы (где присутствует только РНК), здесь имела место концентрация практически чистых рибосом, как подтверждает и седиментация. ДНК удавалось определить только во фракциях второй половины элюата плазмы (рис. 4).  相似文献   
20.
Larvae of Axarus andLipiniella share several apparantly apomorphic features of the mouth-part structure, however adults ofLipiniella show possible relationships toDemeijerea andChironomus. In order to assist in refining the relationships ofAxarus toLipiniella the karyotype ofAxarus festivus was determined and compared to the karyotypes ofLipiniella arenicola andL. moderata. Larvae ofA. festivus from a population in Kansas were monomorphous, with 2n=8, the Ist, IInd and IIIrd chromosomes metacentric, and IVth acrocentric.Axarus festivus therefore differs fromL. arenicola in chromosome number (2n=6), however homologous sections of all chromosomes were identified. Inversions were detected in the Ist, IInd and IIIrd chromosomes ofA. festivus relative toL. arenicola. It was determined that both species have high functional activity, as indicated by the presence of three Balbiani rings, and more than one nucleolus per genome. Differing degrees of polyteny, a feature previously described forL. arenicola, were observed in the salivary glands, with highest degrees of polyteny in cells near the salivary duct. These similarities of chromosome structure indicate close genetic relationships betweenA. festivus andL. arenicola. However, we did not find evidence for similarity ofA. festivus toL. moderata, which supports the previous conclusions byKiknadze et al. (1989) regardingL. arenicola andL. moderata.  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