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1.
We investigated cell proliferation and cell death in the olfactory epithelium (OE) of mice from birth to maturity using bromodeoxyuridine and terminal deoxynucleotidyl transferase nick end labeling. We show that cell death events and proliferative activity diminish concomitantly with age in the OE. Thus, the age-dependent and coordinate diminution in cell proliferative activity and cell death events may serve to maintain the thickness of the OE as mice mature and age.  相似文献   
2.
Five parameters of postcessation smoking withdrawal variability derived from clinical data (T. M. Piasecki, D. E. Jorenby, S. S. Smith, M. C. Fiore, & T. B. Baker, 2003a, 2003b) were predicted from baseline measures and pharmacotherapy assignment. Smokers who were more dependent, older, and high in negative affect reported more severe withdrawal. Women, heavier smokers, and those with a history of depression reported more variable symptoms. Smokers treated with nicotine patch, bupropion, or both reported less severe withdrawal than did those given placebo, but medication did not affect the slope of symptoms over time, day-to-day variability of symptoms, or the size of acute changes in symptoms associated with lapses to smoking. Prior research has shown that these symptom facets predict later relapse: thus, current pharmacotherapies may aid cessation by diminishing withdrawal severity, but they do not affect all clinically important aspects of withdrawal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
3.
One of the methods of achieving high packaging density of passive elements on the PCB is using the capacitors embedded in multilayer PCB. Test structures consisting of embedded capacitors were fabricated using the FaradFlex? capacitive internal layers. Impedance spectroscopy and equivalent circuit modelling was used to determine their electrical properties such as the capacitance, parasitic resistance and inductance. The use of several stages of accelerated ageing allowed us to test the durability of the structures. The results showed good quality stability of the embedded elements. The spatial distribution of the capacitance of the test structures on the surface of the PCB form was tested. The influence of the process parameters during lamination on the values of embedded capacitors was revealed.  相似文献   
4.
Zinc oxy fluoro borate glasses mixed with different concentrations of CoO (ranging from 0 to 2.0 mol%) are synthesized and subsequently crystallized. The scanning electron microscopy pictures have exhibited crystallinity. Differential scanning calorimetric studies have indicated that the prepared samples consist of multiple crystal phases. The X‐ray diffraction patterns have indicated that the glass‐ceramic samples are composed of αZn(BO2)2, (Zn)3(BO3)2, CoF2, CoF3, Co3FB7O13, ZnCo2O4, Co3O4 crystalline phases. The optical absorption and photoluminescence studies have indicated that there is a gradual increase of tetrahedral cobalt ion concentration with increase of CoO concentration in the glass network. IR spectroscopic studies have pointed out increased degree of polymerization of the zinc oxy fluoro borate glass network with increase of CoO content. The analysis of results of dielectric properties indicated increase of insulating strength of the glass‐ceramics with increase of CoO content. Finally, the dielectric breakdown strength of the samples is measured at room temperature in air medium and it is found to increase from 12.9 to 19.2 kV/cm with increase of CoO from 0.2 to 2.0 mol%. The reasons for such increase of breakdown strength are discussed quantitatively in terms of dielectric parameters with aid of data on spectroscopic properties.  相似文献   
5.
The activity of isotactic polypropylene (iPP) nucleating additives during shear flow of composite materials is still not entirely explained. In current work the sol-gel method was employed to synthesize MgO·SiO2 filler, surface-modified with trivalent lanthanum. The crystallization of commercial iPP in the presence of 0.5% by weight La3+ modified or unmodified silicates was analyzed. The wide angle X-ray scattering analysis proved that the presence of even small amount of filler influences significantly on supermolecular structure of iPP. The results of microscope observations confirmed that the lanthanum-modified filler shows the nucleating ability for iPP. In that case a significant reduction of crystallization induction time was noticed. The investigation of iPP crystallization in composites after shear treatment confirmed that the increase of shear rate reduces the nucleating ability of additives. Moreover, the flow of filler particles during shearing may impede the shear-induced crystallization phenomenon.  相似文献   
6.
The direct condensation reaction of prop-2-enal or but-2-enal with mixture of n-aliphatic alcohol and ethylene glycol, in the presence of p-toluenesulphonic acid as catalyst, leads to a complex mixture of saturated, unsaturated, cyclic and linear acetals, moreover, 2-(2-alkoxy-alkyl)-1,3-dioxolanes are the main reaction products. The detailed investigations for n-butanol showed that unsaturated cyclic acetals: 2-vinyl-1,2-dioxolane 1a or 2-(1-propenyl)-1,3-dioxolane 1b , as well as unsaturated linear acetals: 1,1-dibutoxy-prop-2-en 2a or 1,1-dibutoxy-but-2-en 2b are intermediate reaction products. Additionally, it was found in final products presence of eight by-products: 5-butoxy- 4a or 5-butoxy-7-methyl-1,4-dioxepane 4b , 1,1,3-tributoxypropane 5a or 1,1,3-tributoxybutane 5b , 2-[2-(2-hydroxyethoxy)ethyl]- 6a or 2-[2-(2-hydroxyethoxy)propyl]-1,3-dioxolane 6b , 5-(2-hydroxyethoxy)-7-methyl-1,4-dioxepane 7b , 1,3-dibutoxy-1-(2-hydroxyethoxy)-propane 8a or 1,3-dibutoxy-1-(2-hydroxyethoxy)-butane 8b , 1,1-dibutoxy-3-(2-hydroxyethoxy)-propane 9a or 1,1-dibutoxy-3-(2-hydroxyethoxy)-butane 9b , 3-butoxy-1,1-bis-(2-hydroxyethoxy)-propane 10a or 3-butoxy-1,1-bis-(2-hydroxyethoxy)-butane 10b , and 1-butoxy-1,3-bis-(2-hydroxyethoxy)-propane 11a or 1-butoxy-1,3-bis-(2-hydroxyethoxy)-butane 11b , respectively.  相似文献   
7.
The 2-n-alkyl-5-carboxy-5-methyl-1,3-dioxanes were obtained in good yield from the reaction of aliphatic aldehydes with 2,2-bis(hydroxymethyl)propionic acid in dichloromethane solution, catalyzed by p-toluenesulfonic acid monohydrate. Nuclear magnetic resonance analysis indicated that they were pure cis-isomers with the axial configuration of the carboxylic group at the C-5 carbon atom of the 1,3-dioxane ring. The acids were converted, with retention of the configuration, to their sodium salts by reaction with sodium methoxide or sodium hydroxide in methanol. The physicochemical properties of the acids and sodium salts, as well as their surface properties at the aqueous solution-air interface, were determined. Critical micelle concentration, surface excess concentration, surface area demand per molecule of sodium salts at the monomolecular surface layer, and standard free energy of micellization were determined based on surface tension measurements. Part XXXIV in the series: Chemical Structure and Surface Activity. Part XXXIII: A. Piasecki, A. Sokolowski, B. Burczyk, R. Gancarz, and U. Kotlewska, Synthesis, Surface Properties and Hydrolysis of Chemodegradable Anionic Surfactants: Diastereomerically Pure cis- and trans-2,5-Disubstituted-1,3-dioxanes. J. Colloid Interface Sci. 192:74–82 (1997).  相似文献   
8.
9.
The dependence construct fills an important explanatory role in motivational accounts of smoking and relapse. Frequently used measures of dependence are either atheoretical or grounded in a unidimensional model of physical dependence. This research creates a multidimensional measure of dependence that is based on theoretically grounded motives for drug use and is intended to reflect mechanisms underlying dependence. Data collected from a large sample of smokers (N = 775) indicated that all 13 subscales of the Wisconsin Inventory of Smoking Dependence Motives (WISDM-68) have acceptable internal consistency, are differentially present across levels of smoking heaviness, and have a multidimensional structure. Validity analyses indicated the WISDM-68 subscales are significantly related to dependence criteria such as smoking heaviness and to 4th edition Diagnostic and Statistical Manual of Mental Disorders symptoms of dependence and relapse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
10.
Poland is the country, where almost 40% of population inhabit rural areas. So EAA may be an important health problem. The aim of the study was to assess incidence of EAA in different districts in Poland. We asked hospitals to send us lists of patients with diagnosis of EAA established in the period of 1990-1994. In some hospitals we collected information by ourselves. This way, we have got data concerning patients with EAA. The highest prevalence of EAA 1.5-7.0/100,000 population was observed in eastern and south-western regions of Poland. Eastern Poland is rural area with small not specialised farms and possible high exposure to EAA antigens. In south-western Poland (Silesia) keeping pigeons is a very popular hobby, which may explain high incidence of EAA.  相似文献   
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