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Saurabh Unni Vipin Bokade Upendra Bhandarkar Shivasubramanian Gopalakrishnan 《Numerical Heat Transfer, Part A: Applications》2013,63(6):1342-1352
AbstractA study of liquid metal magnetohydrodynamic (MHD) flows is important for analyzing flows in the Test Blanket Module of the proposed International Thermonuclear Experimental Reactor. Possible accident scenarios involve the leakage of coolant into the liquid metal flow. To address this situation, the present article considers the simplified case of two-dimensional isothermal flow of two fluids of different viscosities and electrical conductivities. We present analytical solutions to the fully developed flows and a solver based on OpenFOAM. We validate the solver performance with the analytical solution, and also the limiting cases of single fluid MHD flow and two-fluid hydrodynamic flow. 相似文献
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YV Patskovsky MQ Huang T Takayama I Listowsky WR Pearson 《Canadian Metallurgical Quarterly》1999,361(1):85-93
The goals of this study were 1) to compare the effects of transforming growth factor-beta (TGF-beta) and parathyroid hormone-related protein (PTHrP) on mouse blastocyst attachment and outgrowth in vitro, 2) to determine whether TGF-beta acts through a mechanism involving PTHrP, 3) to examine effects of PTHrP on preimplantation mouse embryo development, and 4) to determine the pattern of expression of PTHrP protein in the uterus of the mouse during early gestation. In the first set of experiments, hatched blastocysts were placed in fibronectin-coated wells. Cultures were treated with PTHrP or TGF-beta1 and assessed at 24, 48, and 72 h for attachment and surface area of blastocyst outgrowth. Results showed that both PTHrP and TGF-beta1 increased blastocyst outgrowth significantly. A PTHrP-neutralizing antibody blocked the stimulatory effect of both PTHrP and TGF-beta1, suggesting that TGF-beta1 acts to increase endogenous production of PTHrP by the blastocyst. Immunoassay of conditioned medium from blastocysts treated with either TGF-beta1 or PTHrP 1-34 confirmed a 3- to 4-fold increase in levels of PTHrP 1-141. In the second series of experiments, pronuclear zygotes were cultured in various concentrations of PTHrP for 96 h. Blastocysts then were subjected to differential fluorescent staining of inner cell mass and trophectoderm cells. Treatment of mouse embryos with the various concentrations of PTHrP altered neither the number developing to the blastocyst stage nor the number of inner cell mass or trophectoderm cells in the resulting blastocysts. In the third experiment, pregnant mice were killed at Days 3, 4, 5, 6, and 7 of gestation, and uterine horns were processed for immunohistochemistry. Uterine sections were stained with antibodies to PTHrP, desmin, and laminin. On Days 3, 4, and 5, uterine luminal and glandular epithelial cells stained intensely for PTHrP, while stromal cells were negative. By Days 6 and 7, decidualized stromal cells stained positively for PTHrP, desmin, and laminin. These results support the hypothesis that TGF-beta and PTHrP play an important role in the process of implantation. 相似文献
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In this paper, two methods are presented. One involves the separation of calcipotriol, a new synthetic analogue, from two related compounds, specifically cholecalciferol (Vitamin D3) and calcitriol (1,25-dihydroxyvitamin D3). The other involves the isolation and assay of calcipotriol from a topical ointment. The study was performed with reversed-phase high-performance liquid chromatography using an RP18 column and ultraviolet detection. Applying the method of Snyder, a mobile phase mixture containing methanol-acetonitrile-water (67:23:10, v/v) was found which achieved a total separation within 18 min. A mobile phase of methanol-water (80:20, v/v) attained a slower elution of calcipotriol. For isolation and assay of calcipotriol from an ointment (Daivonex), dissolution in chloroform gave the highest recovery (> 98%). The isolation and assay process can be performed within 2 h. 相似文献
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Hejtmancik JF; Wingfield PT; Chambers C; Russell P; Chen HC; Sergeev YV; Hope JN 《Protein engineering, design & selection : PEDS》1997,10(11):1347-1352
The beta-crystallins are a major constituent of the mammalian lens, where
they associate into dimers, tetramers and higher order aggregates.
Appropriate association of lens crystallins is important for lens
transparency. To examine the associative properties of betaB2- crystallin,
we have expressed mouse betaB2-crystallin using a baculovirus system.
Recombinant mouse betaB2-crystallin has an estimated monomer molecular
weight of 24 kDa by SDS-PAGE, appropriate immunoreactivity and appropriate
secondary structure as assessed by circular dichroism analysis. The
recombinant betaB2-crystallin associates into a homodimer with a weight
average molecular mass of 39 kDa. The betaB2-crystallin homodimer has an
estimated Kd of 5 x 10(-6) M, slightly greater than that of
betaA3-crystallin, 0.8 x 10(-6) M. When recombinant betaB2-crystallin is
combined with recombinant betaA3- crystallin, a heterodimer is formed
within 10 min of incubation at room temperature. When equilibrium is
reached in 4-6 h, approximately half of each crystallin associates into
heterodimers. Subunit exchange between betaB2-crystallin and
betaA3-crystallin occurs readily in the absence of any denaturing agents.
Thus, rbetaA3-rbetaB2 heterodimer formation can occur under conditions
similar to those found in the eye lens.
相似文献
79.
A high potential analog of riboflavin with a cyano function at the 8-position was synthesized by employing novel reaction conditions, starting from 8-amino-riboflavin. This was converted to the FAD level with FAD synthetase. The reduced 8-CN-riboflavin, unlike normal reduced flavin, has a distinctive absorption spectrum with two distinctive peaks in the near ultraviolet region. The oxidation-reduction potential of the new flavin was determined to be -50 mV, approximately 160 mV more positive than that of normal riboflavin. The 8-CN-riboflavin and 8-CN-FMN were found to be photoreactive and need to be protected from exposure to light. However such complications were not encountered with protein-bound flavins. The apoproteins of flavodoxin and Old Yellow Enzyme (OYE) were reconstituted with the 8-CN-FMN and apoDAAO was reconstituted with 8-CN-FAD. Spectral properties of the enzyme-bound neutral and anionic semiquinones were determined from these reconstituted proteins. In the case of 8-CN-FMN-OYE I, it was shown that the comproportionation reaction of a mixture of reduced and oxidized enzyme bound flavin is very rapid, compared with the same reaction with native protein, resulting in approximately 100% thermodynamically stable anionic semiquinone. In the case of 8-CN-OYE I, it was shown that the rate of reduction of the enzyme bound flavin by NADPH is approximately 40 times faster, and the rate of reoxidation of reduced enzyme bound flavin by oxygen is an order of magnitude slower than with the normal FMN enzyme. This is in accord with the high oxidation-reduction potential of the flavin, which thermodynamically stabilizes the reduced enzyme. 相似文献
80.
针对垃圾渗滤液的高浓度、难降解、具有生物毒性的特点,采用混凝沉降法对其进行处理,以处理出水的CODcr为处理程度的表征指标。通过正交实验,确定最佳复合混凝剂的试剂用量,比较不同反应条件对CODcr去除率的影响,优化操作条件。实验结果表明,最佳复合混凝剂:1 250 mg/LPAC+1 500 mg/LPFS+50 mg/L PAM;最佳条件:pH=7.0,搅拌时间为15 min,沉降时间为20 min;CODcr去除率达到66.9%。 相似文献