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71.
Applied Biochemistry and Biotechnology - One of the most common somatic mutations in breast cancer is found in PIK3CA with a prevalence rate of 18–45%. Different variants of this gene are...  相似文献   
72.
The formation of complex species of dioxouranium(VI) ion with EDTA was studied in the pH range of 1–3.5 and at 25 °C using a combination of potentiometric and spectrophotometric techniques. Results showed evidence for formation of the following species: [UO2H4EDTA]2+, [UO2H3EDTA]+, and [UO2H2EDTA]. Investigations were performed in sodium perchlorate as background electrolyte at 0.1, 0.3, 0.5, 0.7, and 1.0 mol dm? 3. The parameters based on the formation constants were calculated, and the dependences of protonation and the stability constants on ionic strength are described. The dependence on ionic strength of the formation constants was analyzed using the specific ion interaction theory (SIT) model. The stability constant values at infinite dilution, obtained using SIT model, are log β°141 = 6.77, log β°131 = 5.99 and log β°121 = 9.29, where indexes for the overall stability constant, βpqr, refer to the equilibrium pUO22+ + qH+ + rL4? ? MpHqLr(2p + q ? 4r). The specific interaction coefficients are also reported.  相似文献   
73.
Structural Chemistry - Dihydrofolate reductase (DHFR) is an essential enzyme that participates in folate metabolism and purine and thymidylate synthesis in cell proliferation. It converts...  相似文献   
74.
The energy deposition mesh tally option of MCNPX Monte Carlo code is very useful for 3-Dimentional (3D) dose calculations. In this study, the 3D dose calculation was done for CT-based Monte Carlo treatment planning in which the energy deposition mesh tally were superimposed on merged voxel model. The results were compared with those of obtained from the common energy deposition (*F8) tally method for all cells of non-merged voxel model. The results of these two tallies and their respective computational times are compared, and the advantages of the proposed method are discussed. For this purpose, a graphical user interface (GUI) application was developed for reading CT slice data of patient, creating voxelized model of patient, optionally merging adjacent cells with the same material to reduce the total number of cells, reading beam configuration from commercial treatment planning system transferred in DICOM-RT format, and showing the isodose distribution on the CT images. To compare the results of Monte Carlo calculated and TiGRT planning system (LinaTech LLC, USA), treatment head of the Siemens ONCOR Impression accelerator was also simulated and the phase-space data on the scoring plane just above the Y-jaws was created and used. The results for a real prostate intensity-modulated radiation therapy (IMRT) plan showed that the proposed method was fivefold faster while the precision was almost the same.  相似文献   
75.
Different strategies of reliability theory for the analysis of coherent systems have been studied by various researchers. Here, the Gini-type index is utilized as an applicable tool for the study and comparison of the ageing properties of complex systems. A new stochastic order in terms of Gini-type index is introduced to compare the speed of ageing of components and systems. The parallel-series and series-parallel systems with shared components are studied by their corresponding Gini-type indexes. Also, the generalization of Gini-type index for the multidimensional case is discussed, and is used to compare components lifetimes properties in the presence of other dependent components. It is shown that the ageing properties of a component lifetime can differ when the other components are working or have already failed. Numerous illustrative examples are given for better intuition of Gini-type and generalized Gini-type indexes throughout the paper.  相似文献   
76.
A. Jabbari 《Semigroup Forum》2012,85(1):160-168
In Jabbari and Namioka (Milan J. Math. 78:503?C522, 2010), the authors characterized the spectrum M(W) of the Weyl algebra W, i.e. the norm closure of the algebra generated by the family of functions $\{n\mapsto x^{n^{k}}; x\in\mathbb{T}, k\in\mathbb{N}\}$ , ( $\mathbb{T}$ the unit circle), with a closed subgroup of $E(\mathbb{T})^{\mathbb{N}}$ where $E(\mathbb{T})$ denotes the family of the endomorphisms of the multiplicative group $\mathbb{T}$ . But the size of M(W) in $E(\mathbb{T})^{\mathbb{N}}$ as well as the induced group operation were left as a problem. In this paper, we will give a solution to this problem.  相似文献   
77.
Jabbari A  Houk KN 《Organic letters》2006,8(26):5975-5978
[Structure: see text] Density functional theory studies of the hetero-Cope reactions of 4-nitroso-1-butenes and nitrosobicyclo[2.2.2]hexenes are reported. The reactions proceed via concerted mechanisms. The electron-withdrawing methoxycarbonyl group alpha- to the nitroso group decreases the activation barrier. Lewis acids such as SbF5 and TiCl4 accelerate the reactions, as has been found experimentally by Zakarian and Lu.  相似文献   
78.
We continue our work (Jabbari and Vishki in Bull. Aust. Math. Soc. 79: 129–145, 2009) to give a more explicit characterization of the topological centre of the Ellis groups corresponding to the so-called skew product dynamical systems on the finite dimensional tori.  相似文献   
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