Cysteine-179 of IkappaB kinase beta plays a critical role in enzyme activation by promoting phosphorylation of activation loop serines

IkappaB kinase beta (IKKbeta) subunit of IKK complex is essential for the activation of NF-kappaB in response to various proinflammatory signals. Cys-179 in the activation loop of IKKbeta is known to be the target site for IKK inhibitors such as cyclopentenone prostaglandins, arsenite, and antirheumatic gold compounds. Here we show that a mutant IKKbeta in which Cys-179 is substituted with alanine had decreased activity when it was expressed in HEK-293 cells, and TNF stimulation did not restore the activity. Phosphorylation of activation loop serines (Ser-177 and Ser-181) which is required for IKKbeta activation was reduced in the IKKbeta (C179A) mutant. The activity of IKKbeta (C179A) was partially recovered when its phosphorylation was enforced by coexpression with mitogen-activated protein kinase kinase kinases (MAPKKK) such as NF-kappaB inducing kinase (NIK) and MAPK/extracellular signal-regulated kinase kinase kinase 1(MEKK1) or when the serine residues were replaced with phospho-mimetic glutamate. The IKKbeta (C179A) mutant was normal in dimer formation, while its activity abnormally responded to the change in the concentration of substrate ATP in reaction mixture. Our results suggest that Cys-179 of IKKbeta plays a critical role in enzyme activation by promoting phosphorylation of activation-loop serines and interaction with ATP.     

A simple taste analyzing system design for visual and quantitative analysis of different tastes using multi-array chemical sensors and pattern recognition techniques

In this paper, we describe design of a simple taste analyzing system using sensory system based on a multi-array chemical sensor (MACS) and personal digital assistant (PDA) for visual and quantitative analysis of different tastes using pattern recognition techniques. The sensory system is communicated with PDA, which has several interesting benefits for data analysis and display, via wireless using the Bluetooth. A various pattern recognition techniques are adapted including spider map, principal component analysis (PCA) and fuzzy C-means (FCM) algorithm to classify visually data patterns detected by the sensory system. The proposed techniques can be determined the cluster centers and membership grade of patterns through the unsupervised way. The membership grade of an unknown pattern, which does not shown previously, can be visually and analytically determined. Throughout the experimental trails, the taste analyzing system is demonstrated robust performance through data acquisition via wireless communication and visual and quantitative analysis of different tastes for the liquids. The system, which is implemented as a simple hand-held taste analyzing instrument, can be applicable to on-site taste monitoring.     

Elliptic equations with measurable coefficients in Reifenberg domains

We prove W1,p estimates for elliptic equations in divergence form under the assumption that for each point and for each sufficiently small scale there is a coordinate system so that the coefficients have small oscillation in (n−1) directions. We assume the boundary to be δ-Reifenberg flat and the coefficients having small oscillation in the flat direction of the boundary.     

Wavelength-dependent photofragmentation and photoionization of gaseous (eta4-cycloocta-1,5-diene)(eta5-cyclopentadienyl)cobalt

Gas-phase photoreactions and photoproducts of the mixed-ligand compound (eta(4)-cycloocta-1,5-diene)(eta(5)-cyclopentadienyl)cobalt are reported. Significant amounts of the monoligated complexes CoCOD and CoCp are produced, and the relative amounts are wavelength dependent. The COD ligand (with the weakest metal-ligand bonds) is always preferentially labilized as expected, but the relative amounts of the CoCOD and CoCp fragments change by 1 order of magnitude as the excitation wavelength is changed. The gas-phase photoreactions exhibit other surprising features that are uncommon in the photoreactions of organometallic compounds in the gas phase. Significant amounts of the intact cation are formed, in contrast to most reported reactions where fragmentation of the weak metal-ligand bonds precedes ionization. Most surprisingly, fragmentation of the ligands occurs while the ligands are still coordinated. The resulting metal complexes contain ligand fragments that remain coordinated to the metal. Breaking several carbon-carbon bonds with retention of weaker metal-ligand bonds is unexpected. For example, C(5)H(5) undergoes fragmentation while still coordinated to the cobalt, yielding smaller compounds such as Co(CH)(+), Co(C(2)H(2))(+), Co(C(3)H(3))(+), and Co(C(4)H(6))(+). Correspondingly, coordinated COD yields Co(C(6)H(6))(+), Co(C(5)H(5))(+), Co(C(4)H(6))(+), Co(C(3)H(3))(+), Co(C(2)H(2))(+), and Co(CH)(+). The wavelength dependence of the ligand labilization is examined by utilizing mass-selected resonance enhanced multiphoton ionization spectroscopy. Both broad bands and sharp lines are observed in the mass-selected excitation spectra. The action spectra obtained in the gas phase while monitoring the cobalt ion follow the absorption onset found in solution. The changes in fragmentation pathways are interpreted in terms of the initially accessed excited state.     

Electromagnetic interference shielding by using conductive polypyrrole and metal compound coated on fabrics

Electromagnetic interference (EMI) shielding materials of complex type of conductive polypyrrole (PPy) as an intrinsically conducting polymer and silver‐palladium (AgPd) metal compound coated on woven or non‐woven fabrics are synthesized. From dc conductivity and SEM photographs of PPy/fabric complexes, we discuss charge transport mechanism and the homogeneity of coating on the fabrics. The EMI shielding efficiency of PPy/fabric and AgPd/fabric complexes is in the range of 8 ～ 80 dB depending on the conductivity and the additional Ag vacuum evaporation. The highest EMI shielding efficiency of PPy/fabric complexes vacuum‐evaporated by Ag is ～80 dB, indicating potential materials for military uses. We propose that PPy/fabrics are excellent RF and microwave absorber because of the relatively high absorbance and low reflectance of the materials. Copyright © 2002 John Wiley & Sons, Ltd.     

The definition of basic TEDS of IEEE 1451.4 for sensors for an electronic tongue and the proposal of new template TEDS for electrochemical devices

It is important to define a standard method to store basic sensor information, such as the type and the structure of sensors for an electronic tongue system and there is no such method defined in the IEEE 1451.4 transducer electronic data sheet (TEDS) so far. The major challenge is to choose a suitable standard template that can be used with sensors for electronic tongues. However, the standard templates provide an imprecise specification when used with sensing devices for electronic tongues. In this paper, we present definitions of the basic TEDS of IEEE 1451.4 for sensors for an electronic tongue system and propose a new template TEDS for IEEE 1451.4 for potentiometric devices.     

Biodegradable Polycarbonate Synthesis by Copolymerization of Carbon Dioxide with Epoxides Using a Heterogeneous Zinc Complex

As a means for the chemical fixation of carbon dioxide and the synthesis of biodegradable polycarbonates, copolymerizations of carbon dioxide with various epoxides such as cyclohexene oxide (CHO), cyclopetene oxide, 4-vinyl-1-cyclohexene-1,2epoxide, phenyl glycidyl ether, allyl glycidyl ether, propylene oxide, butene oxide, hexene oxide, octene oxide, and 1-chloro-2,3-epoxypropane were investigated in the presence of a double metal cyanide catalyst (DMC). The DMC catalyst was prepared by reacting K₃Co(CN)₆ with ZnCl₂, together with tertiary butyl alcohol and poly(tetramethylene ether glycol) as complexing reagents and was characterized by various spectroscopic methods. The DMC catalyst showed high activity (526.2 g-polymer/g-Zn atom) for CHO/CO₂ (P_CO2 = 140 psi) copolymerization at 80 °C, to yield biodegradable aliphatic polycarbonates of narrow polydispersity (M_w/M_n = 1.67) and moderate molecular weight (M_n = 8900). The DMC catalyst also showed high activities with different CO₂ reactivities for other epoxides to yield various aliphatic polycarbonates with narrow polydispersity.     

Polymerizations of ethylene and styrene initiated with trisiloxane-bridged dinuclear titanium metallocene/MMAO catalyst systems

Two kinds of the trisiloxane-bridged dinuclear titanium metallocene-type complexes were synthesized. They are monocyclopentadienyl and biscyclopentadienyl dinuclear titanocenes with trisiloxane bridges. The above complexes with modified methylaluminoxane (MMAO) cocatalyst initiate the polymerizations of ethylene and styrene to produce high-density polyethylene and syndiotactic polystyrene. In addition, a copolymer of ethylene and styrene was obtained.     

Fourth-order parabolic equations with weak BMO coefficients in Reifenberg domains

We study optimal W2,p-regularity for fourth-order parabolic equations with discontinuous coefficients in general domains. We obtain the global W2,p-regularity for each 1<p<∞ under the assumption that the coefficients have suitably small BMO semi-norm of weak type and the boundary of the domain is δ-Reifenberg flat. The situation of our main theorem arises when the conductivity on fractals is controlled by a random variable in the time direction.     

Parabolic equations in time dependent Reifenberg domains

In this paper we define time dependent parabolic Reifenberg domains and study Lp estimates for weak solutions of uniformly parabolic equations in divergence form on these domains. The basic assumption is that the principal coefficients are of parabolic BMO space with small parabolic BMO seminorms. It is shown that Lp estimates hold for time dependent parabolic δ-Reifenberg domains.