Pressure representation and boundary regularity of the Navier-Stokes equations with slip boundary condition

We first represent the pressure in terms of the velocity in . Using this representation we prove that a solution to the Navier-Stokes equations is in under the critical assumption that , with r?3, while for r=3 the smallness is required. In [H.J. Choe, Boundary regularity of weak solutions of the Navier-Stokes equations, J. Differential Equations 149 (2) (1998) 211-247], a boundary L^∞ estimate for the solution is derived if the pressure on the boundary is bounded. In our work, we remove the boundedness assumption of the pressure. Here, our estimate is local. Indeed, employing Moser type iteration and the reverse Hölder inequality, we find an integral estimate for L^∞-norm of u.     

Reaction and stabilizing mechanism of the cross-type macromonomers in the dispersion polymerization of styrene

The cross-type (C-VUM) and linear-type (L-VUM) bifunctional vinyl urethane macromonomers and polystyrene (PS) using these macromonomers were synthesized in the dispersion polymerization in ethanol, and the reaction and stabilizing mechanism of the macromonomers was proposed. The structural verification of the macromonomers and PS was studied using (1)H NMR. The weight-average particle size of C-PS (PS prepared with C-VUM) and L-PS (PS prepared with L-VUM) decreased from 4.41 to 1.36 microm and from 3.56 to 1.52 microm, whereas the average-molecular weight of those increased from 34,100 to 100,500 g/mol and from 32,200 to 71,800 g/mol, respectively. The XPS result showed that the C-PS was anchored with a larger amount of PEG than that of the L-PS on the particle surface. Thus, the reaction and stabilizing mechanism of the macromonomers for the formation of PS particles is proposed as the following. The particle surface of the C-PS is surrounded by a large amount of tail shaped macromonomers leading to higher molecular weights and smaller particle sizes. On the other hand, the particle surface of the L-PS is comprised of relatively small amounts of loop shaped macromonomers inducing lower molecular weights and larger particles of L-PS than C-PS.     

Postsynthetically Modified Alkoxide-Exchanged Ni2(OR)2BTDD: Synergistic Interactions of CO2 with Open Metal Sites and Functional Groups

Postsynthetic modifications (PSMs) of metal–organic frameworks (MOFs) play a crucial role in enhancing material performance through open metal site (OMS) functionalization or ligand exchange. However, a significant challenge persists in preserving open metal sites during ligand exchange, as these sites are inherently bound by incoming ligands. In this study, for the first time, we introduced alkoxides by exchanging bridging chloride in Ni₂Cl₂BTDD (BTDD=bis (1H-1,2,3,–triazolo [4,5-b],–[4′,5′-i]) dibenzo[1,4]dioxin) through PSM. Rietveld refinement of synchrotron X-ray diffraction data indicated that the alkoxide oxygen atom bridges Ni(II) centers while the OMSs of the MOF are preserved. Due to the synergy of the existing OMS and introduced functional group, the alkoxide-exchanged MOFs showed CO₂ uptakes superior to the pristine MOF. Remarkably, the tert-butoxide-substituted Ni_T exhibited a nearly threefold and twofold increase in CO₂ uptake compared to Ni₂Cl₂BTDD at 0.15 and 1 bar, respectively, as well as high water stability relative to the other exchanged frameworks. Furthermore, the Grand Canonical Monte Carlo simulations for Ni_T suggested that CO₂ interacts with the OMS and the surrounding methyl groups of tert-butoxide groups, which is responsible for the enhanced CO₂ capacity. This work provides a facile and unique synthetic strategy for realizing a desirable OMS-incorporating MOF platform through bridging ligand exchange.     

Synthesis and Properties of Novel Nonlinear Optical Polyester Containing Cyanovinylnitroresorcinoxy Group

Novel X-type polyester 5 containing 4-(2’-carbomethoxy-2’-cyano)vinyl-6-nitroresorcinoxy group as nonlinear optical (NLO) chromophore, which constitutes parts of the polymer backbone, was prepared and characterized. Polyester 5 is soluble in common organic solvents such as N,N-dimethylformamide and acetone. Polyester 5 shows a thermal stability up to 280°C from thermogravimetric analysis with glass-transition temperature obtained from differential scanning calorimetry of near 116°C. The second harmonic generation (SHG) coefficient (d₃₃) of poled polymer film at the 1064 nm fundamental wavelength is 4.25 × 10^?9 esu. The dipole alignment exhibits a thermal stability even at 4°C higher than glass-transition temperature (T_g), and no significant SHG decay is observed below 120°C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.     

Dictyostelium cells bind a secreted autocrine factor that represses cell proliferation

Background  

Dictyostelium cells secrete the proteins AprA and CfaD. Cells lacking either AprA or CfaD proliferate faster than wild type, while AprA or CfaD overexpressor cells proliferate slowly, indicating that AprA and CfaD are autocrine factors that repress proliferation. CfaD interacts with AprA and requires the presence of AprA to slow proliferation. To determine if CfaD is necessary for the ability of AprA to slow proliferation, whether AprA binds to cells, and if so whether the binding requires the presence of CfaD, we examined the binding and effect on proliferation of recombinant AprA.     

Effects of Nanocrystalline Porous TiO2 Films on Interface Adsorption of Phthalocyanines and Polymer Electrolytes in Dye-Sensitized Solar Cells

Summary: We have synthesized three kinds of titanylphthalocyanines with different crystal structures (TiOPcs; PcT2000R, PcT3000R, and PcT1100S) and analyzed their crystal structure by X-ray Diffraction (XRD), Fourier transfer IR (FT-IR) spectroscopy, and Transmission Electron Microscope (TEM). From experimental results, we have confirmed that PcT2000R was estimated to be alpha-form; PcT3000R was beta-form, and PcT1100S was gamma-form. Quasi-solid state dye-sensitized solar cell (DSSC) devices were prepared with a polymer electrolyte using TiOPcs as a co-adsorbent. The DSSC device using TiOPc has higher power conversion efficiency than without TiOPc, due to decrease of electron transfer distance by the interface adsorption between TiO₂ film and polymer electrolyte. Also, we have studied the effects of the crystal structures of TiOPcs on the property of polymer electrolyte and the performance of the DSSC device. The best result on power conversion efficiency was 7.13% in DSSC device using PcT3000R having its highest stability. The open-circuit voltage (V_oc) was 0.69 V, the short-circuit current density (J_sc) was 20.02 mA/cm², and the Fill Factor (FF) was 0.52. the addition of TiOPc as co-adsorbent is useful for improve to the performances of DSSC devices such as V_oc, J_sc, and power conversion efficiency.     

Convergence in L space for the homogenization problems of elliptic and parabolic equations in the plane

We study the convergence rate of an asymptotic expansion for the elliptic and parabolic operators with rapidly oscillating coefficients. First we propose homogenized expansions which are convolution forms of Green function and given force term of elliptic equation. Then, using local L^p-theory, the growth rate of the perturbation of Green function is found. From the representation of elliptic solution by Green function, we estimate the convergence rate in L^p space of the homogenized expansions to the exact solution. Finally, we consider L2(0,T:H1(Ω)) or L∞(Ω×(0,T)) convergence rate of the first order approximation for parabolic homogenization problems.     

A Comparative Study of Biologically and Chemically Fabricated Synthesized AgNPs’ Supplementation with Respect to Heat-Shock Proteins,Survival, and Hatching Rates of Chicken Embryos: An In Ovo Study

The present study examined the characterization and concentration of Brassica oleracea L. var. capitata f. rubra (BOL, commonly known as red cabbage) extracted AgNPs (BOL-AgNPs) and chemically (CHE) synthesized AgNPs (CHE-AgNPs) in chicken embryos through in ovo injections. We investigated the effects of both AgNPs on the survival, hatchability, body weight, and expressions of heat-shock proteins (HSPs). The BOL-AgNPs and CHE-AgNPs at (T1) amounted 100, at (T2) 1000, at (T3) 2500, and at (T4) 5000 µg/100 µl/egg, respectively through in ovo injections. At the end of the experimental period, the body and liver weights of the chicks were altered between the groups and among the concentrations. The serum levels of SGOT and SGPT were significantly increased at BOL-T3 and -T4. Survival and hatching rates were more reduced in the BOL-T3- and -T4-treated groups than at BOL-T1 and -T2. Nevertheless, they were more diminished in the CHE-AgNPs than in the BOL-AgNPs. The CHE-AgNPs revealed the presence of micronuclei and nuclear abnormalities, in contrast to BOL-T4. The mRNA and protein expressions of HSP-60 and 70 in the liver were higher in CHE-AgNPs than in BOL-AgNPs. Hence, plant-synthesized AgNPs are superior in ovo nano-nutrition carriers of nutrients without toxicity than CHE-AgNPs.     

Expression, High Cell Density Culture and Purification of Recombinant EC-SOD in Escherichia coli

Superoxide dismutase (SOD) catalyzes the dismutation of the biologically toxic superoxide anion into oxygen and hydrogen peroxide and is deployed by the immune system to kill invading microorganisms. Extracellular SOD (EC-SOD) is a copper- and zinc-containing glycoprotein found predominantly in the soluble extracellular compartment that consists of ～30-kDa subunits. Here, we purified recombinant EC-SOD3 (rEC-SOD) from Escherichia coli BL21(DE3) expressing a pET-SOD3-1 construct. Cells were cultured by high-density fed-batch fermentation to a final OD₆₀₀ of 51.8, yielding a final dry cell weight of 17.6 g/L. rEC-SOD, which was expressed as an inclusion body, comprised 48.7% of total protein. rEC-SOD was refolded by a simple dilution refolding method and purified by cation-exchange and reverse-phase chromatography. The highly purified rEC-SOD thus obtained was a mixture of monomers and dimers, both of which were active. The molecular weights of monomeric and dimeric rEC-SOD were 25,255 and 50,514 Da, respectively. The purified rEC-SOD had 4.3 EU/mg of endotoxin and the solubility of rEC-SOD was more than 80% between pH 7 and 10. In 2 L of fed-batch fermentation, 60 mg of EC-SOD (99.9% purity) could be produced and total activity was 330.24 U. The process established in this report, involving high-cell-density fermentation, simple dilution refolding, and purification with ion-exchange and reverse-phase chromatography, represents a commercially viable process for producing rEC-SOD.