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991.
Accumulation of ochratoxin A in rat kidney in vivo and in cultivated renal epithelial cells in vitro
Biological applications of triplex forming oligonucleotides will require the development of oligomers with high avidity and specificity. We examined the binding enhancement resulting from intercalator conjugation to both parallel design (polythymidine T15) and antiparallel design (polypurine AG15, for binding a 15 base pair polypurine-polypyrimidine sequence in the IL-2R alpha gene enhancer) oligomers under various ionic strength and temperature conditions. Oligonucleotides were conjugated through a urea link to 6,9 diamino-3-methoxy acridine (to give T15C and AG15C). Intercalator conjugation dramatically enhanced the specific triplex binding avidity (Kd = 5 nM for AG15C and 275 nM for T15C at 25 degrees C, compared to 2 microM for AG15 and > 50 microM for T15 at 25 degrees C), without detectable binding to an inappropriate target sequence. Surprisingly, triplex formation with AG15C occurred at lower Mg2+ concentrations than with T15C. AG15 and AG15C showed rapid Mg2+ dependent self association, but not T15C or T15. T15C triplex formation occurred rapidly (completion in less than 4 min), while AG15C bound to its target sequence more slowly over 20-24 h. Thus, binding constants in the low nanomolar range are now achievable with intercalator conjugated polypurine antiparallel binding oligonucleotides, a prerequisite for biological applications of such agents. 相似文献
992.
993.
MC Bueno Jayme Gallani RC Rodrigues Colombo E de Araújo Cintra S Brunelli Rigacci 《Canadian Metallurgical Quarterly》1996,4(2):179-199
The overall purpose of this study was to explore nurses' feelings about the applicability and adequacy of a pilot model of nursing assessment (PMNA) developed for coronary care units (CCU) in order to obtain data that could help in establishing a definitive model. The evaluation, performed by 11 CCU nurses, showed that they considered the development and implementation of PMNA as valuable, and that its design was adequate for interviewing cardiac patients. These results will be employed in the elaboration of a definitive model of nursing assessment. 相似文献
994.
995.
Sudhoff S.D. Corzine K.A. Hegner H.J. Delisle D.E. 《Energy Conversion, IEEE Transaction on》1996,11(3):508-514
A new average-value model of a synchronous machine fed load-commutated converter is set forth in which the stator dynamics are combined with the DC link dynamics. This model is shown to he extremely accurate in predicting system transients and in predicting frequency-domain characteristics such as the impedance looking into the synchronous machine fed load-commutated converter. The model is verified against a detailed computer simulation and against a hardware test system, thus providing a three-way comparison. The proposed model is shown to be much more accurate than models in which the stator dynamics are neglected 相似文献
996.
The catalytic activity of KGa-priderite, K1.6Ga1.6Ti6.4O16, and its related compound KGa8Ga9Ti15O56 was investigated for the selective reduction of nitrogen monoxide (NO) with propylene (C3H6) in the presence of high oxygen concentrations. The KGa-priderite showed significant activity during this reaction, but the related compound showed only a little activity. These compounds are quite different from the conventional catalysts for NOx selective reduction and are characterized by the fact that their properties are free from the effects of solid acidity and support metals. This difference was attributable to the NO desorption rate at the surface of these compounds. It has become clear that the KGa-priderite catalyst remarkably adsorbed NO, and it is suggested that the amount of NO adsorbed and the amount of catalytic activity are able to be increased by the design of priderite structure. 相似文献
997.
A general numerical model is described for the dissolution kinetics of spherical particles in binary systems for any combination of first order reactions at the particle-matrix interface and long distance diffusion within the matrix. The model is applicable to both finite and infinite media and handles both complete and partial particle dissolution. It is shown that interfacial reactions can have a strong effect on the dissolution kinetics, the solute concentration at the particle-matrix interface and the solute concentration profile in the matrix. 相似文献
998.
999.
The interaction of different metal oxides such as Co3O4, NiO, Al2O3, Cr2O3, Fe2O3 and SiO2 with Na2SO4 at a temperature of 1100 and 1200 K in flowing oxygen has been studied. The thermogravimetric studies for each system were
carried out as a function of Na2SO4 in the mixture. The presence of different constituents in the reaction products were identified by X-ray diffraction analysis
and the morphologies of the reaction products were characterized using metallography and scanning electron microscopy (SEM).
The formation of products was also investigated by thermodynamic computation of free energies of the reactions and the study
of relevant equilibrium phase diagrams. The soluble species in the aqueous solutions of the reaction products were determined
quantitatively using atomic absorption spectrophotometry.
The high temperature interaction products usually contain a 3-phase structure namely, Na2O·M2O
x
, M2O
x
and metal sulphide and/or metal sulphate. The formation of Na2O·M2O
x
depends upon the solid state solubility of metal oxide in the molten salt at high temperatures. Under limited solubility
conditions Na2O·M2O
x
is invariably formed, but as soon as this condition is relaxed the oxide. M2O
x
, precipitates and forms a separate phase. 相似文献
1000.
Saito M. Yoshitomi T. Hara H. Ono M. Akasaka Y. Nii H. Matsuda S. Momose H.S. Katsumata Y. Ushiku Y. Iwai H. 《Electron Devices, IEEE Transactions on》1993,40(12):2264-2272
A p-MOSFET structure with solid-phase diffused drain (SPDD) is proposed for future 0.1-μm and sub-0.1-μm devices. Highly doped ultrashallow p+ source and drain junctions have been obtained by solid-phase diffusion from a highly doped borosilicate glass (BSG) sidewall. The resulting shallow, high-concentration drain profile significantly improves short channel effects without increasing parasitic resistance. At the same time, an in situ highly-boron-doped LPCVD polysilicon gate is introduced to prevent the transconductance degradation which arises in ultrasmall p-MOSFETs with lower process temperature as a result of depletion formation in the p+-polysilicon gate. Excellent electrical characteristics and good hot-carrier reliability are achieved 相似文献