3,949 research outputs found

    Change in gene expression of mouse embryonic stem cells derived from parthenogenetic activation

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    BACKGROUND We previously established parthenogenetic mouse embryonic stem cells (ESCs) and this study was subsequently conducted for elucidating the influence of oocyte parthenogenesis on gene expression profile of ESCs. METHODS Gene expression of parthenogenetic ESC (pESC)-1 or pESC-2 was separately compared with that of two normally fertilized ESC (nfESC) lines (B6D2F1 and R1 strains), and quantification of mRNA expression was conducted for validating microarray data. RESULTS In two sets of comparison, reaction of 11 347 and 15 454 gene probes were altered by parthenogenesis, while strain difference changed the expression of 15 750 and 14 944 probes. Level of correlation coefficient was higher in the comparisons between normal fertilization and parthenogenesis (0.974-0.985) than in the comparisons between strains of nfESCs (0.97-0.971). Overall, the expression of 3276-3329 genes was changed after parthenogenesis, and 88% (96/109) of major functional genes differentially (P < 0.01) expressed in one comparison set showed the same change in the other. When we monitored imprinted genes, expression of nine paternal and eight maternal genes were altered after parthenogenesis and 88% (14/16) of these was confirmed by mRNA quantification. CONCLUSIONS The change in gene expression after parthenogenesis was similar to, or less than, the change induced by a strain difference under a certain genetic background. These results may suggest the clinical feasibility of parthenogenesis-derived, pluripotent cell

    Genome-scale metabolic model of the fission yeast Schizosaccharomyces pombe and the reconciliation of in silico/in vivo mutant growth

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    <p>Abstract</p> <p>Background</p> <p>Over the last decade, the genome-scale metabolic models have been playing increasingly important roles in elucidating metabolic characteristics of biological systems for a wide range of applications including, but not limited to, system-wide identification of drug targets and production of high value biochemical compounds. However, these genome-scale metabolic models must be able to first predict known <it>in vivo</it> phenotypes before it is applied towards these applications with high confidence. One benchmark for measuring the <it>in silico</it> capability in predicting <it>in vivo</it> phenotypes is the use of single-gene mutant libraries to measure the accuracy of knockout simulations in predicting mutant growth phenotypes.</p> <p>Results</p> <p>Here we employed a systematic and iterative process, designated as Reconciling <it>In silico/in vivo</it> mutaNt Growth (RING), to settle discrepancies between <it>in silico</it> prediction and <it>in vivo</it> observations to a newly reconstructed genome-scale metabolic model of the fission yeast, <it>Schizosaccharomyces pombe</it>, SpoMBEL1693. The predictive capabilities of the genome-scale metabolic model in predicting single-gene mutant growth phenotypes were measured against the single-gene mutant library of <it>S. pombe</it>. The use of RING resulted in improving the overall predictive capability of SpoMBEL1693 by 21.5%, from 61.2% to 82.7% (92.5% of the negative predictions matched the observed growth phenotype and 79.7% the positive predictions matched the observed growth phenotype).</p> <p>Conclusion</p> <p>This study presents validation and refinement of a newly reconstructed metabolic model of the yeast <it>S. pombe</it>, through improving the metabolic model’s predictive capabilities by reconciling the <it>in silico</it> predicted growth phenotypes of single-gene knockout mutants, with experimental <it>in vivo</it> growth data.</p

    Shape optimization of an autonomous underwater vehicle with a ducted propeller using computational fluid dynamics analysis

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    ABSTRACTAutonomous Underwater Vehicles (AUVs) provide a useful means of collecting detailed oceano-graphic information. The hull resistance of an AUV is an important factor in determining the power requirements and range of the vehicle. This paper describes a procedure using Computational Fluid Dynamics (CFD) for determining the hull resistance of an AUV under development, for a given propeller rotation speed and within a given range of AUV velocities. The CFD analysis results reveal the distribution of the hydrodynamic values (velocity, pressure, etc.) around the AUV hull and its ducted propeller. The paper then proceeds to present a methodology for optimizing the AUV profile in order to reduce the total resistance. This paper demonstrates that shape optimization of conceptual designs is possible using the commercial CFD package contained in Ansys™. The optimum design to minimize the drag force of the AUV was identified for a given object function and a set of constrained design parameters

    The Effect of Cyclosporine and Dexamethasone on Suppression of Medial Thickening after Arterial Injury in Rats

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    Vascular proliferative lesion is one of the most important causes of stenosis and late thrombosis in arterial reconstructions. We studied the effect of cyclosporine and dexamethasone on decreasing the hyperplastic response after experimental arterial injury in rats. Ninety female rats were assigned to one of four groups, each receiving daily subcutaneous injections of either (1) saline (control), or (2) cyclosporine(CYA) 5mg/Kg/D, or (3) dexamethasone (DEXA) O. 1 mg/Kg/D, or (4) CYA 5mg/kg/D and DEXA O. Img/kg/D. Injections were started 1 day before the intimal injury and continued daily for 6 weeks. Arterial injury was created in 90 rats by rotating a Imm coronary dilator in the right common iliac artery. The vessels were harvested 1,4,6 weeks after injury and the thickness of the tunica media was measured. In the control group the injured iliac artery had significant medial thickening when compared to the noninjured (P(O. 0001) 1 week after injury. Injured arteries treated with CYA or DEXA or CYA and DEXA showed significantly less medial thickening when compared to that of control (P(O. 001) but no significant difference was noted among drug treated groups for 1 and 4 weeks of treatment. At 6 weeks, however, medial thickness in the CYA and DEXA group was significantly less than that of the CYA or DEXA group(P( O. 05). These data suggest that CYA and DEXA are effective in suppressing the hyperplatic myointimal reaction to an intimal injury. In addition, these data also provide the evidence that immunological mechanisms may modulate vascular proliferative lesions

    Experimental Verification of Modal Identification of a High-rise Building Using Independent Component Analysis

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    Abstract Independent component analysis is one of the linear transformation methods based the techniques for separating blind sources from the output signals of the system. Recently, the method has been analytically applied to the identification of mode shapes and modal responses from the output signal of structures. This study aims to experimentally validate the blind source separation using ICA method and propose a novel method for identification of the modal parameters from the decomposed modal responses. The result of the experimental testing on the three-story steel scale model shows that the mode shapes obtained by ICA method are in good agreement with those by the analytical and peak-picking method in the frequency domain. Based on the robust mathematical model, ICA can calculate the natural frequency and damping ratio effectively using the probability distribution function of the instantaneous natural frequency determined by Hilbert transform of the decomposed modal responses and the change in the output covariance. Finally, the validity of the proposed method paves the way for more effective output-only modal identification for assessment of existing steel-concrete buildings

    Effect of Bisphosphonates on Anodized and Heatâ Treated Titanium Surfaces: An Animal Experimental Study

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141247/1/jper1035.pd

    Concurrence of Stevens-Johnson Syndrome and Bilateral Parotitis after Minocycline Therapy

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    Minocycline is an antibiotic of tetracycline derivatives that is commonly used in the treatment of moderate to severe acne vulgaris. It has been reported to cause rare adverse events from mild cutaneous eruption to severe forms including drug-induced lupus, serum sickness-like reaction, and hypersensitivity reactions, etc. The risks of adverse events attributed to minocycline have not been ascertained reliably and there are concerns about the safety of minocycline which could possibly result in life-threatening events such as the Stevens-Johnson syndrome. Here we demonstrate an unusual case of Stevens-Johnson syndrome in conjunction with bilateral parotitis after the intake of minocycline in a Korean boy suggesting discreet use of the drug
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