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121.
Theoretical Foundations of Chemical Engineering - An environmentally friendly solvent, namely, polypropylene glycol 425, has been proposed for the extraction of metal ions from chloride solutions...  相似文献   
122.
OBJECTIVES: This study investigated effects of acute plasma volume expansion on plasma levels and urinary output of two endogenous Na,K-ATPase inhibitors, marinobufagenin-like and ouabain-like immunoreactive substances. METHODS: Plasma volume was expanded for 3 h via intravenous saline infusion in three groups of anesthetized dogs--nontreated (n = 5); pretreated with rabbit antidigoxin (n = 5); and pretreated with rabbit antimouse (control) antibody (n = 4). RESULTS: Plasma marinobufagenin-like immunoreactivity increased to 11.87 +/- 3.16 nmol.l-1 (vs. 0.30 +/- 0.16 nmol.l-1) within 10 min of volume expansion, in parallel with a 15% increase in LVdP/dt, then decreased to 2.21 +/- 0.59 nmol.l-1, and in 90 min increased to 11.8 +/- 2.8 nmol.l-1, in parallel with the maximal natriuretic response. Plasma concentrations of ouabain-like immunoreactive material were increased after 90 min of saline infusion (0.019 +/- 0.004 nmol.l-1 vs. 0.139 +/- 0.056 nmol.l-1). Pretreatment of the animals with antidigoxin antibody blocked the positive inotropic and reduced natriuretic response to volume expansion, and decreased the urinary release of marinobufagenin-like, but not ouabain-like, material. CONCLUSIONS: These results show the presence of marinobufagenin-like immunoreactive substance in dog plasma and suggest that mammalian EDLF may have a bufodienolide nature. Endogenous marinobufagenin-like immunoreactive substance, which is likely to cross-react with antidigoxin antibody, is involved in the natriuretic and positive inotropic responses to plasma volume expansion.  相似文献   
123.
In this study we show that the previously described uvs112 (uvs12) mutation blocks one of the steps of the excision repair pathway. The properties of this mutation permit the assignment of the UVS112 gene to the RAD3 epistasis group. It was established that the uvs112 mutation caused a 2·5-fold reduction in the number of recombinants produced by conversion and also significantly increased the frequency of mitotic crossing-over in interplasmid recombination. Tetrad analysis placed the UVS112 gene on the left arm of chromosome IX, approximately 20 cM from HIS5. The analysis of mitotic recombination revealed that UVS112 lies between HIS6 and HIS5, and is an allele of the RAD25 gene.  相似文献   
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The Ni, Co, Ba, and Sr profiles in the diffusion zones produced between hexagonal Z-ferrites (Sr3Co2Fe24O41/Ba3Co2Fe24O41, Ba3Co2Fe24O41/Ba3Ni2Fe24O41, and Sr3Co2Fe24O41/Ba3Ni2Fe24O41) by annealing at 1420–1520 K were used to evaluate the cation interdiffusion coefficients by the Boltzmann–Matano method over the whole composition range.  相似文献   
127.
An examination of 30 patients against the background of using both the operative and conservative methods of treatment was performed in order to study the rheological properties of blood and selection of the most informative tests for diagnosis of microcirculatory disturbances in diseases of the gastrointestinal tract and gastroduodenal area. The authors propose methods of investigation of deformability and viscosity of erythrocytes in patients with the surgical diseases in question. The methods are simple, quite handy for any surgical hospital and polyclinic laboratories. In addition to being used in investigations of the aggregative ability of erythrocytes and viscosity of the whole blood, these methods can be of use in express diagnosis of rheological disorders. The endogenous intoxication in patients with the diseases in question was found to be accompanied by deep rheological disturbances. The deformability of erythrocytes and their viscosity index which can pass ahead of the shifts in other parameters characterizing the hemocoagulative and rheological properties of blood are changed. A conclusion is drawn that the parameters of the erythrocyte deformability and viscosity can be an additional criteria of the adequacy of therapy used for patients with the diseases in question.  相似文献   
128.
It is well known that as concrete hydrates its permeability decreases. Continued hydration, however, is not the only mechanism which causes such reduction. Self-sealing, which is largely attributed to the dissolution and redeposition of hydrates, and autogenous healing of cracks, can also significantly reduce the flow. This paper reviews the relative effects of self-sealing, autogenous healing and hydration.  相似文献   
129.
Mutants with enhanced spontaneous mutability (hsm) to canavanine resistance were induced by N-methyl-N-nitrosourea in Saccharomyces cerevisiae. One bearing the hsm3-1 mutation was used for this study. This mutation does not increase sensitivity to the lethal action of different mutagens. The hsm3-1 mutation produces a mutator phenotype, enhancing the rates of spontaneous mutation to canavanine resistance and reversions of lys1-1 and his1-7. This mutation increases the rate of intragenic mitotic recombination at the ADE2 gene. The ability of the hsm3 mutant to correct DNA heteroduplex is reduced in comparison with the wild-type strain. All these phenotypes are similar to ones caused by pms1, mlhl and msh2 mutations. In contrast to these mutations, hsm3-1 increases the frequency of ade mutations induced by 6-HAP and UV light. Epistasis analysis of double mutants shows that the PMS1 and HSM3 genes control different mismatch repair systems. The HSM3 gene maps to the right arm of chromosome II, 25 cM distal to the HIS7 gene. Strains that bear a deleted open reading frame YBR272c have the genetic properties of the hsm3 mutant. The HSM3 product shows weak similarity to predicted products of the yeast MSH genes (homologs of the Escherichia coli mutS gene). The HSM3 gene may be a member of the yeast MutS homolog family, but its function in DNA metabolism differs from the functions of other yeast MutS homologs.  相似文献   
130.
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