排序方式: 共有13条查询结果,搜索用时 359 毫秒
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Estela M. Alvarez Patricia H. Risso Carlos A. Gatti Martín S. Armesto Mariano Burgos Verónica M. Relling 《Colloid and polymer science》2006,284(9):1016-1023
Colloidal casein aggregates (CCA) prepared from soluble whole bovine caseinates in the presence of Ca2+ and phosphate (Pi) ions by addition of different citrate (Cit) concentrations showed different mineral and proteic composition. Citrate concentration conditions the Ca and Pi concentrations incorporated into CCA, probably due to the complexing effect of this anion on calcium. A significant change in the incorporated Ca/Pi ratio at 8 mM citrate could very likely be associated to changes in CCA net charge. The incorporation of individual caseins to the colloidal particles obtained, as well as their average size and size distribution, depended also on the Cit concentration used [Cit]P. αS- and β-caseins assembled in the CCA structure sharply decreased at a [Cit]P higher than 15 mM, i.e., at a low Ca2+ concentration in the aggregates, showing that the presence of this cation is necessary for the incorporation of these caseins. An inverse relationship between the aggregation step rate in CCA enzymic coagulation and their average size was observed. The aggregation rate vs the average size curve obtained at [Cit]P 8 mM clearly differed from the curves obtained at 10 and 12 mM, respectively, a fact probably related to a change in the CCA net charge. This behavior showed the effect of citrate concentration on CCA functional properties. 相似文献
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Mullighan CG Goorha S Radtke I Miller CB Coustan-Smith E Dalton JD Girtman K Mathew S Ma J Pounds SB Su X Pui CH Relling MV Evans WE Shurtleff SA Downing JR 《Nature》2007,446(7137):758-764
Chromosomal aberrations are a hallmark of acute lymphoblastic leukaemia (ALL) but alone fail to induce leukaemia. To identify cooperating oncogenic lesions, we performed a genome-wide analysis of leukaemic cells from 242 paediatric ALL patients using high-resolution, single-nucleotide polymorphism arrays and genomic DNA sequencing. Our analyses revealed deletion, amplification, point mutation and structural rearrangement in genes encoding principal regulators of B lymphocyte development and differentiation in 40% of B-progenitor ALL cases. The PAX5 gene was the most frequent target of somatic mutation, being altered in 31.7% of cases. The identified PAX5 mutations resulted in reduced levels of PAX5 protein or the generation of hypomorphic alleles. Deletions were also detected in TCF3 (also known as E2A), EBF1, LEF1, IKZF1 (IKAROS) and IKZF3 (AIOLOS). These findings suggest that direct disruption of pathways controlling B-cell development and differentiation contributes to B-progenitor ALL pathogenesis. Moreover, these data demonstrate the power of high-resolution, genome-wide approaches to identify new molecular lesions in cancer. 相似文献
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EP Sheretov VS Gurov MV Dubkov OV Korneeva 《Rapid communications in mass spectrometry : RCM》1999,13(16):1699-1702
In this article we compare the classical monopole mass filter of von Zahn and the monopole mass filter with a hyperbolic V-shaped electrode. The experimental results and those of computer simulation for both mass spectrometers are presented. We show that the replacement of a conventional 90 degrees V-shaped electrode by an electrode with a hyperbolic profile substantially improves the peak shape of any given mass, and increases the mass resolution by a factor of 3-4 and the abundance sensitivity by a factor of 100. The potential of high analytical performance combined with electroforming techniques for electrode manufacture indicate future practical uses of such instruments. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Mullighan CG Miller CB Radtke I Phillips LA Dalton J Ma J White D Hughes TP Le Beau MM Pui CH Relling MV Shurtleff SA Downing JR 《Nature》2008,453(7191):110-114
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DC magnetization, neutron depolarization and neutron diffraction (with both polarized and unpolarized neutrons) measurements
have been reported for the Co1.1−x
Zn
x
Ge0.1Fe1.2O1 spinels with x=0.5, 0.6 and 0.7. Neutron depolarization and neutron diffraction measurements confirm the presence of a long range ferrimagnetic
ordering of the local canted spins in these ferrite samples. The observed features of low field magnetization have been explained
under the framework of thermally activated domain wall movement of ferrimagnetic arrangement of local canted spins. An important
role of magnetic anisotropy (due to the presence of Co2+ ions) in establishing the magnetic ordering and domain kinetics in these ferrites has been observed. 相似文献
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MV Muftakhov YV Vasil'ev VA Mazunov 《Rapid communications in mass spectrometry : RCM》1999,13(12):1104-1108
Appearance energies of [M-H](-) ions from carbonyl compounds R-CO-R' (R,R' = H, CH(3), NH(2), OH) have been measured by means of negative ion mass spectrometry in resonant electron capture mode. Values of electron affinity of the corresponding radicals, CH(2)&dbond;C(X)O, NH&dbond;C(X)O and O&dbond;C(X)O, have been determined. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Individuals respond differently to drugs and sometimes the effects are unpredictable. Differences in DNA that alter the expression or function of proteins that are targeted by drugs can contribute significantly to variation in the responses of individuals. Many of the genes examined in early studies were linked to highly penetrant, single-gene traits, but future advances hinge on the more difficult challenge of elucidating multi-gene determinants of drug response. This intersection of genomics and medicine has the potential to yield a new set of molecular diagnostic tools that can be used to individualize and optimize drug therapy. 相似文献