Human obese gene expression: alternative splicing of mRNA and relation to adipose tissue localization

The aim of this work was to obtain further information about the origin of fluoride profiles in cementum. Fluoride was administered to rats at varying doses (0.50, 100 ppm F in drinking water) and for different durations (4, 13 and 25 weeks). Fluoride distribution across the full thickness of molar cementum in rats was measured by means of an abrasive micro-sampling technique. The average fluoride concentrations in cementum increased significantly with increasing dose and duration of fluoride administration. The relative reduction of the average fluoride concentrations after cessation of fluoride administration was 94.2-36.5% at 50 ppm F and 62.2-49.2% at 100 ppm F in the outer layers (1-60 microns) and 91.5-24.1% at 50 ppm F and 74.1-7.6% at 100 ppm F in the middle (61-120 microns) layers of the cementum, respectively. The reduction rates were more closely related to the time intervals following cessation rather than fluoride concentrations in drinking water or specificity within the cementum. Two factors which may influence this are new cementum formation after withdrawal of fluoride and some fluoride release from cementum surfaces when the fluoride supply stopped. It was concluded that the cessation of fluoride administration reduced the fluoride concentration on the outer layers of cementum differing from bone where reduction occurs across the entire thickness.     

Optical, electrical and structural investigations on Cd1−xZnxSe sintered films for photovoltaic applications

II–VI polycrystalline semiconducting materials have come under increased scrutiny because of their wide use in the cost reduction of devices for photovoltaic applications. Cd_1−xZn_xSe is an important semiconducting alloy because of the tunability of its physical parameters such as band gap and lattice parameters by controlling its stoichiometry. Many more material characteristics of it would be altered and excellently controlled by controlling system composition x.Polycrystalline thin films of Cd_1−xZn_xSe with variable composition (0x1) have been deposited onto ultra-clean glass substrates by sintering process. The optical, structural and electrical transport properties of Cd_1−xZn_xSe thin films have been examined. The optical band gap and optical constants of these films were determined by using double beam spectrophotometer. The DC conductivity and activation energy of the films were measured in vacuum by two-probe technique. The Schottky junction of Cd_1−xZn_xSe with indium was made and the barrier height and ideality factor were determined using current–voltage characteristics. The nature of sample, crystal structure and lattice parameters were determined from X-ray diffraction patterns. The films were polycrystalline in nature having cubic zinc-blende structure over the whole range studied.Sintering is very simple and viable compared to other cost intensive methods. The results of the present investigation will be useful in characterizing the material, Cd_1−xZn_xSe, for its applications in photovoltaics.     

Homocoupling Defects in a Conjugated Polymer Limit Exciton Diffusion

Copolymers such as PCDTBT (poly(N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole))) are commonly employed as donor material in bulk heterojunction solar cells. Recently, chemical defects such as homocouplings have been shown to form at the material synthesis stage, strongly reducing the short circuit current in organic photovoltaics. Here it is shown that both low molecular weight and homocoupling defects reduce the short circuit current of solar cells because of limited exciton diffusion. A model that unites and explains the influence of both chemical parameters with the distribution of conjugation lengths is proposed. The connection between limited exciton diffusion and short circuit current is revealed via kinetic Monte Carlo simulation of bulk heterojunctions. The findings are likely applicable for copolymers in general.     

Alkaline PF resins linear extension by urea condensation with hydroxybenzylalcohol groups

The linear increase of phenol–formaldehyde (PF) resins by reaction under alkaline conditions of the ortho- and para-hydroxybenzylalcohol groups of the PF resin with small molar percentages of urea was followed by model compounds reactions. Apparent rate constants of the reactions of urea with o-and p-hydroxybenzylalcohols were obtained. Both the ortho- and para-isomerides appeared to react faster with urea than for their autocondensation. The ortho-isomeride appears to react faster with urea than the para-isomeride, under alkaline conditions. Autocondensation under alkaline conditions instead appears to be faster in the case of p-hydroxybenzylalcohol. The properties of PF resins prepared with the addition of small amounts of urea appear to be consistent with what is observed in the model compounds reactions: Their gel times become faster and viscosity increases with increasing amounts of urea addition. © 1993 John Wiley & Sons, Inc.     

Never Mind The Content,Let'S Understand The Process: An Alternative Perspective On Recent Federal Urban Initiatives

The Federal Government's urban and regional initiatives have attracted considerable attention. Authors from diverse perspectives have commented on the increased prominence of urban issues within the Federal sphere (Bunker and Minnery 1993), the number and size of these programs (Orchard 1993), the ability of these initiatives to achieve their goals (Paris 1992; Badcock 1993a) and the plethora of reports on urban and related issues (Alexander 1994). Much of this research implicitly compares the policy initiatives of the 1990s with those of the Department of Urban and Regional Development (DURD) and all of it judges the Federal Government's initiatives against the author's perception of an appropriate outcome or outcomes. This paper argues that the objective or ‘rationalist’ approach to the Federal Government's activities in this policy milieu is in some respects mis-placed. While we must consider the consequences, it is folly to concentrate solely on outcomes and ignore the processes of policy formation and program development.     

Influence of ligno-cellulosic particles on tribological properties of boards

There are two main possibilities to substitute conventional wood material in the panel production: the use of wood of fast-growing trees plantations and/or the use of alternative ligno-cellulosic raw materials. Especially particleboards produced from the ‘‘energetic’’ willow present the same or better mechanical parameters compared to particleboards conventionally produced mainly from soft woods. Increasing bio-fuel production, mostly from rape, will cause an escalation of the rape cultivation area and, as a result, will augment the amount of waste (rape straw) to be utilized. The aim of this study was to verify the friction coefficient of the new board types in tribological contact with tools surfaces. The investigations were performed in situ. The results of the friction coefficient related to the tools surfaces as well as lingo-cellulose materials are presented.     

Neue epidural arbeitende Gehirndrucksonde — Labortests und Tierversuche — Stand der Entwicklung

The controlling of the intracranial pressure (ICP) is of significant importance for the treatment of patients suffering from cerebral trauma. There are two ways used in the clinical practice to measure the ICP, the intraventricular (inside the dura) and the epidural measurement (between the dura and the cranial-bone). From the viewpoint of accuracy of measurement the intraventricular measurement is to be preferred. However, from the medical point of view this method also involves bacteriological danger. For that reason the improvement of the epidural devices, based on an analysis of the at the time being used measurement devices, is described in detail in this paper.