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31.
Ahmed ZM Masmoudi S Kalay E Belyantseva IA Mosrati MA Collin RW Riazuddin S Hmani-Aifa M Venselaar H Kawar MN Tlili A van der Zwaag B Khan SY Ayadi L Riazuddin SA Morell RJ Griffith AJ Charfedine I Caylan R Oostrik J Karaguzel A Ghorbel A Riazuddin S Friedman TB Ayadi H Kremer H 《Nature genetics》2008,40(11):1335-1340
32.
Curran JE Jowett JB Elliott KS Gao Y Gluschenko K Wang J Abel Azim DM Cai G Mahaney MC Comuzzie AG Dyer TD Walder KR Zimmet P MacCluer JW Collier GR Kissebah AH Blangero J 《Nature genetics》2005,37(11):1234-1241
Chronic inflammation has a pathological role in many common diseases and is influenced by both genetic and environmental factors. Here we assess the role of genetic variation in selenoprotein S (SEPS1, also called SELS or SELENOS), a gene involved in stress response in the endoplasmic reticulum and inflammation control. After resequencing SEPS1, we genotyped 13 SNPs in 522 individuals from 92 families. As inflammation biomarkers, we measured plasma levels of IL-6, IL-1beta and TNF-alpha. Bayesian quantitative trait nucleotide analysis identified associations between SEPS1 polymorphisms and all three proinflammatory cytokines. One promoter variant, -105G --> A, showed strong evidence for an association with each cytokine (multivariate P = 0.0000002). Functional analysis of this polymorphism showed that the A variant significantly impaired SEPS1 expression after exposure to endoplasmic reticulum stress agents (P = 0.00006). Furthermore, suppression of SEPS1 by short interfering RNA in macrophage cells increased the release of IL-6 and TNF-alpha. To investigate further the significance of the observed associations, we genotyped -105G --> A in 419 Mexican American individuals from 23 families for replication. This analysis confirmed a significant association with both TNF-alpha (P = 0.0049) and IL-1beta (P = 0.0101). These results provide a direct mechanistic link between SEPS1 and the production of inflammatory cytokines and suggest that SEPS1 has a role in mediating inflammation. 相似文献
33.
34.
Dominant modifier DFNM1 suppresses recessive deafness DFNB26 总被引:8,自引:0,他引:8
Riazuddin S Castelein CM Ahmed ZM Lalwani AK Mastroianni MA Naz S Smith TN Liburd NA Friedman TB Griffith AJ Riazuddin S Wilcox ER 《Nature genetics》2000,26(4):431-434
More than 50% of severe childhood deafness is genetically determined, approximately 70% of which occurs without other abnormalities and is thus termed nonsyndromic. So far, 30 nonsyndromic recessive deafness loci have been mapped and the defective genes at 6 loci, DFNB1, DFNB2, DFNB3, DFNB4, DFNB9 and DNFB21, have been identified, encoding connexin-26 (ref. 3), myosin VIIA (ref. 4), myosin XV (ref. 5), pendrin, otoferlin and alpha-tectorin, respectively. Here we map a new recessive nonsyndromic deafness locus, DFNB26, to a 1.5-cM interval of chromosome 4q31 in a consanguineous Pakistani family. A maximum lod score of 8.10 at theta=0 was obtained with D4S1610 when only the 8 affected individuals in this family were included in the calculation. There are seven unaffected family members who are also homozygous for the DFNB26-linked haplotype and thus are non-penetrant. A dominant modifier, DFNM1, that suppresses deafness in the 7 nonpenetrant individuals was mapped to a 5.6-cM region on chromosome 1q24 with a lod score of 4.31 at theta=0 for D1S2815. 相似文献
35.
36.
W. Wiktor-Jedrzejczak C. Szczylik P. Górnaś S. J. Sharkis A. Ahmed 《Cellular and molecular life sciences : CMLS》1979,35(4):546-547
Summary The lowest cell number in the normal marrow transplant, which allows the cure of W/Wv anemia was found to be between 104 and 105. This exceeds by several times the lowest cell number necessary for the haemopoietic colony formation. Therefore, either the colony forming cell is not the haemopoietic stem cell but rather its progeny, or this cell requires an aid from some other cells to exert its activity.Acknowledgments. We are indebted to Doc. Dr Maksymilian Siekierzynski for his help and advice and to Miss Elzbieta Szewczyk for expert technical assistance. 相似文献
37.
Ahmed Khalafallah 《清华大学学报》2008,13(Z1):325-328
The United States real estate market is currently facing its worst hit in two decades due to the slowdown of housing sales. The most affected by this decline are real estate investors and home developers who are currently struggling to break-even financially on their investments. For these investors, it is of utmost importance to evaluate the current status of the market and predict its performance over the shortterm in order to make appropriate financial decisions. This paper presents the development of artificial neural network based models to support real estate investors and home developers in this critical task. The paper describes the decision variables, design methodology, and the implementation of these models. The models utilize historical market performance data sets to train the artificial neural networks in order to predict unforeseen future performances. An application example is analyzed to demonstrate the model capabili-ties in analyzing and predicting the market performance. The model testing and validation showed that the error in prediction is in the range between -2% and +2%. 相似文献
38.
基于NOAA/SWPC公布的太阳活动数据,我们选取第24太阳活动峰年附近的12个连续月份(2011年7月至2012年6月)和第23太阳活动周谷年附近的12个连续月份(2005年7月至2006年6月),统计了这两段时间中太阳黑子群和耀斑的活动规律,并根据时间、黑子群分布纬度、寿命和磁场类型等对峰年和谷年进行了详细分析和比较,主要结论如下所述.(1)黑子群数随时间的变化在峰年和谷年均比较随机,峰年期间黑子数比谷年增多1.5倍左右.耀斑爆发与黑子群活动具有良好的相关性,但峰年期间存在某个月份耀斑数很少的现象,而谷年期间存在某个月份耀斑数集中增多的现象.(2)无论峰年还是谷年,δ类型黑子群的耀斑产率(耀斑总数与黑子群总数之比)最大,但β型黑子群产生的耀斑爆发最多.耀斑产率与磁场类型有密切关系,但与其所处太阳活动周中的阶段无关.(3)黑子群和耀斑的纬度分布的南北不对称性,以X级耀斑最为显著.峰年较谷年的耀斑数增加主要集中在C级和M级.(4)耀斑产率同黑子群寿命具有良好的相关性,但黑子群的数目同它们的寿命之间没有明显的规律. 相似文献
39.
A metakaolin(Mk)-based geopolymer cement from Tunisian Mk mixed with different amounts of silica fume(SiO_2/Al_2O_3 molar ratio varying between 3.61 and 4.09) and sodium hydroxide(10M) and without any alkali silicate solution, is developed in this work. After the samples were cured at room temperature under air for 28 d, they were analyzed by X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, environmental scanning electron microscopy, mercury intrusion porosimetry, ~(27)Al and ~(29)Si nuclear magnetic resonance(NMR) spectroscopy, and compression testing to establish the relationship between microstructure and compressive strength. The XRD, FTIR, and ~(27)Al and ~(29)Si NMR analyses showed that the use of silica fume instead of alkali silicate solutions was feasible for manufacturing geopolymer cement. The Mk-based geopolymer with a silica fume content of 6 wt%(compared with those with 2% and 10%), corresponding to an SiO_2/Al_2O_3 molar ratio of 3.84, resulted in the highest compressive strength, which was explained on the basis of its high compactness with the smallest porosity. Silica fume improved the compressive strength by filling interstitial voids of the microstructure because of its fine particle size. In addition, an increase in the SiO_2/Al_2O_3 molar ratio, which is controlled by the addition of silica fume, to 4.09 led to a geopolymer with low compressive strength, accompanied by microstructures with high porosity. This high porosity, which is responsible for weaknesses in the specimen, is related to the amount of unreacted silica fume. 相似文献
40.
The structural and magnetic properties of essentially phase pure AlFe_2B_2 prepared by arc melting were compared with a sample containing impurities. Analysis was carried out by means of synchrotron X-ray diffraction, magnetic measurements and M?ssbauer spectroscopy. The analysis of synchrotron X-ray diffraction data confirmed the orthorhombic structure of space group Cmmm for AlFe_2B_2 with Al_(13)Fe_4 as main impurity phase. The magnetic measurements revealed an unsaturated ferromagnetic state in AlFe_2B_2 with a transition temperature(T_c) of 286 K. Isothermal magnetization measurment at 5 K gave a saturation magnetization of 0.7 μB per Fe atom while Arrott plots establish the second order nature of ferromagnetic transition. The thermal evolution of M?ssbauer spectra confirmed the ferromagnetic nature of this material revealing an hyperfine field of 73 kOe and an isomer shift of 0.46 mm/s at 100 K. The M?ssbauer spectra of a phase pure sample was compared with the one containing impurity phases. It is suggested that the low temperature paramagnetic contribution in M?ssbauer spectra of phase pure material may have its origin in some intrinsic phenomena arising from defects or inhomogeneities in crystal structure. 相似文献