Earticle

Polyurethane resin containing isocyanate is marked by excellent tensile and mechanical strengths and this test aims to gauge its applicability as a medical high polymer. Tris [2-(acryloyloxy)ethyl]isocyanurate and hexamethylenediisocyanate were added to a basic mixing ratio of HEMA (2-hydroxyethyl methacrylate), MMA (methyl methacrylate), NVP (n-vinyl- 2-pyrrolidone) and crosslink agent, EGDMA (ethylene glycol dimethacrylate) with increasing proportions and copolymerized respectively. Also, the basic physical properties of the polymerized high polymers including refraction rate, tensile strength, light transmission and water content were measured to confirm that they are appropriate as hydrogelcontact lenses. After measuring the physical properties of high performance polymers produced by adding tris [2-(acryloyloxy) ethyl]isocyanurate, it was found that the average tensile strengths of sample TRIS1 to TRIS10 were between 0.285 and 0.612 kgf, while the average values of refractive index were ranged from 1.441 to 1.449 with water content from 30.00 to 37.35%.The measurement of physical properties of the copolymers generated by adding hexamethylenediisocyanate showed that the average tensile strength of sample HEXA1 to HEXA10 ranged from 0.267 to 1.742 kgf, the refractive index ranged from 1.443 to 1.475 and water contents were in the range of 21.22 to 35.58%. In all combinations the transmission rates satisfied the transmittance of general hydrogel contact lenses. From theresults, it is possible to conclude that the produced copolymers can be used as contact lens materials with excellent tensile strength.

In this manuscript, we report a protocol to determine most of the lowest energy conformations from the ensemble of conformations. 12-crown-4 was taken as study compound to get the most of energy minima conformations. Molecular dynamic (MD) simulation for 1 nanosecond (ns) was performed at 300, 500, 700, 900 and 1100 K temperature. At particular interval conformations were sampled. Then Gaussian program was used to minimize compounds using PM6 energy levels. Duplicates were removed by checking energy as well as mirror image conformations, and only unique conformations were retained for the next 6-31+G* level minimization. It was observed that upto certain increment in temperature the number of unique conformations were increased, but afterword it decreased.

To combine the micro rain radar and microwave radiometer cloud liquid water, we estimate the cloud physical thickness from the difference between the MTSAT-1R cloud top height and cloud base height of visual observation of Daegwallyeong weather station, and the cloud liquid water path of micro rain radar is obtained by multiplying the liquid water content of micro rain radar and the estimated cloud physical thickness. The trend of microwave diometer liquid water path agrees with that of the micro rain radar during small precipitation. We study these characteristics of micro rain radar and microwave radiometer for small precipitation to obtain the combined cloud water content of micro rain radar and microwave radiometer, constantly operated regardless to the rainfall.

G-protein-coupled receptor (GPCR) superfamily is the largest known receptor family, characterized by seven transmembrane domains and considered to be an important drug target. In this study we focused on an orphan GPCR termed as GPR18. As there is no X-ray crystal structure has been reported for this receptor, we report on a homology model of GPR18. Template structure with high homology was used for modeling and ten models were developed. A model was selected and refined by energy minimization. The selected model was further validated using various parameters. Our results could be a starting point for further structure based drug design.

Formation of amyloid-β (Aβ) aggregates is a core process in the pathogenesis of Alzheimer’s disease. Importance of interaction of the length variants, Aβ42 and Aβ40 in the process and consequent cytotoxicity has been pointed out for wild-type Aβ previously. In addition to confirming the findings, the current study demonstrates that the potential interaction is also important for cytotoxicity of the Flemish and Dutch sequence variants. The interaction could strengthen or inhibit cytotoxicity of Aβ42/Aβ40 mixture, depending on interaction time of the length variants as well as the ratio and amyloidogenic property. The inhibitory effect was prominent at the early stage of aggregate formation in less amyloidogenic Flemish Aβ42/Aβ40 mixture, while strengthened cytotoxicity was exhibited at the stage in potently amyloidogenic Dutch variant and at the later stage in wild-type and the Flemish variant. The samples showing relatively robust cytotoxicity were those enriched in Aβ protofibril-like structures, implying strong correlation of the structure with cytotoxicity. The different consequence of the interaction on sequence variants is likely due to differential amyloidogenic property of each Aβ40 variant, rather than that of Aβ42, because aggregation rates and levels of Aβ40 variants are greatly variable depending on the sequence, compared to Aβ42 variants. These studies may highlight a potential role of Aβ40 in the cytotoxicity, providing a novel mechanistic insight into the pathogenesis of each FAD-associated variant.

Tributyltin hydride (n-Bu3SnH), an endocrine disruptor, was slowly polymerized by the group 4 Cp’2TiCl2/N-selectride (Cp’ = C5H5, Cp; Me-C5H4, Me-Cp; Me5C5, Cp*) catalyst combination to give two phases of products: one is an insoluble cross-linked solid, polystannane in 3-25% yield as minor product via disproportionation/dehydrocoupling combination process, and the other is an oil, hexabutyldistannane in 65-90% yield as major product via simple dehydrocoupling process. Disproportionation/dehydrocoupling process first produced a low-molecular-weight oligostannane possessing partial backbone Sn-H bonds which then underwent an extensive cross-linking reaction of backbone Sn-H bonds, resulting in the formation of an insoluble polystannane. The disproportionation/dehydrocoupling of a tertiary hydrostannane mediated by early transition metallocene/inorganic hydride is quite unusual and applicable.

Robust design is an approach to reducing performance variation of quality characteristic values in quality engineering. Taguchi has an idea that mean and variation are handled simultaneously to reduce the expected loss in products and processes. In the Taguchi parameter design, the product-array approach using orthogonal arrays is mainly used. However, it often requires an excessive number of experiments. An alternative approach, which is called the combined-array approach, was studied. In these studies, only single quality characteristic (or response) was considered. In this paper we propose how to simultaneously optimize for multiple quality characteristics (or multiresponse) using desirability function when we used the combined-array approach to assign control and noise factors.

In this thesis, we consider isoparametric curves of quadratic F-Bézier curves. F-Bézier curves unify C-Bézier curves whose basis is ｛sint, cost, t, 1 ｝and H-Bézier curves whose basis is ｛sinht, cosht, t, 1｝. Thus F-Bézier curves are more useful in Geometric Modeling or CAGD(Computer Aided Geometric Design). We derive the relation between the quadratic F-Bézier curves and the quadratic rational Bézier curves. We also obtain the geometric properties of isoparametric curve of the quadratic F-Bézier curves at both end points and prove the continuity of the isoparametric curve.

We are interested in the rate of convergence of solutions of 2D Navier-Stokes equations in a smooth bounded domain as the viscosity tends to zero under Navier friction condition. If the initial velocity is smooth enough( u|∈ W²,p, p>2), it is known that the rate of convergence is linearly propotional to the viscosity. Here, we consider the rate of convergence for nonsmooth velocity fields when the gradient of the corresponding solution of the Euler equations belongs to certain Orlicz spaces. As a corollary, if the initial vorticity is bounded and small enough, we obtain a sublinear rate of convergence.

Histone deacetylase (HDACs) is an enzyme family that deacetylates histones and non-histones protein. Availability of crystal structure of HDAC8 has been a boosting factor to generate target based inhibitors. Hydroxamic class is the most studied one to generate potent inhibitors. HDAC class I and class II enzymes are emerging as a therapeutic target for cancer, diabetes, inflammation and other diseases. DNA methylation and histone modification are epigenetic mechanism, is important for the regulation of cellular functions. HDACs enzymes play essential role in gene transcription to regulate cell proliferation, migration and death. The aim of this article is to provide a comprehensive overview about structure and function of HDACs enzymes, histone deacetylase inhibitors (HDACi) and HDACs enzymes as a therapeutic target for cancer, inflammation and diabetes.