Spatially-Resolved Calorimetry: Using IR Thermography to Measure Temperature and Trapped NOX Distributions on a NOX Adsorber Catalyst

Palladium catalysts supported on CeO_2, Ce_0.75Zr_0.25O₂, ZrO_2, TiO₂, Nb₂O₅, Al₂O₃ were studied on the total oxidation of butyl carbitol. Several techniques were used to characterize the samples such as diffuse reflectance spectroscopy (DRS), temperature programmed reduction (TPR), cyclohexane dehydrogenation and CO temperature programmed desorption (TPD). DRS and TPR results revealed the presence of bulk PdO and PdO with strong interaction with the support. The catalytic tests showed the following order for decreasing activity: Pd/Ce_0.75Zr_0.25O₂ > Pd/CeO₂ > Pd/TiO₂ > Pd/Nb₂O₅ > Pd/Al₂O₃ > Pd/ZrO₂. However, when the turnover frequency (TOF) was calculated, all the samples had similar values.     

Characterization of Active Species in Cu-Beta Zeolite by Temperature-Programmed Reduction Mass Spectrometry (TPR-MS)

The number and type of copper species present in an under-exchanged Cu-Beta zeolite catalyst were characterized using temperature-programmed reduction mass spectrometry (TPR-MS). Both H₂ consumption and H₂O evolution were tracked, yielding additional insights into the nature of Cu species. Prior to the TPR-MS tests, catalyst samples were subjected to various high- temperature aging treatments in the presence of O₂ in He, in order to assist with interrogating and resolving different types of sites. Absence of reducible species in the precursor material was confirmed by subjecting the H-form of the same zeolite to the TPR. Upon aging at temperatures below 700 °C, the TPR pattern showed several distinct peaks of different intensities. Aging at 800 °C led to shifting and broadening of these H₂ consumption peaks, as well as to some reduction of the integral amount of the reducible sites. The 900 °C exposure resulted in a drastic change of the TPR pattern, with several new well-resolved H₂ consumption peaks, indicative of drastic changes in the catalyst structure. The integral amount of H₂ consumed quantitatively matched the amount of Cu species present in the catalyst, assuming the $ {\text{Cu}}^{ 2+ } \to {\text{Cu}}^{0} $ stoichiometry. The combination of experimental findings in this work lends support to a hypothesis that different TPR peaks are indicative of different types of sites rather than of step-wise reduction of copper species.     

Outcomes from the Resources for Enhancing Alzheimer's Caregiver Health (REACH) program for bereaved caregivers.

Although preventive efforts for bereaved individuals have not been shown to be particularly effective in past studies, it has been suggested that intervention effects might be underestimated due to methodological issues such as short follow-up assessments. Thus, the present study aimed to assess the efficacy (as whole intervention packages and as component parts) of the Resources for Enhancing Alzheimer's Caregiver Health (REACH) interventions in preventing complicated grief, normal grief, and depressive symptoms at a longer term follow-up assessment among bereaved caregivers (N = 224). On average, active interventions showed a statistically significant effect on normal grief symptoms (d = 0.28), exhibited a trend toward improvement on complicated grief symptoms (d = 0.25), and demonstrated little impact on depressive symptoms (d = 0.09). Interestingly, the examination of intervention components revealed differential effects, whereby cognitive and behavioral strategies were most effective at reducing levels of complicated grief, information and emotional support were most effective for addressing normal grief, and environmental modifications were most effective for ameliorating depressive symptoms. These findings suggest that different preloss interventions might be warranted depending on a caregiver's unique clinical presentation and combination of risk factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Overview of polyethylene as a bearing material: comparison of sterilization methods

Polyethylene has been used for more than 30 years as an orthopaedic bearing material; however, there has been recent concern regarding the early failure of a small percentage of the polyethylene bearings. The damage seen in some retrieved polyethylene components has been linked to gamma radiation sterilization in air, which was widely used by the industry for years. Gamma radiation in air has been documented to cause an increase in oxidation and degradation of mechanical properties with time. The degradation of polyethylene initiated by gamma sterilization in air has led the orthopaedic industry toward alternative sterilization methods, including gamma radiation in an inert gas or vacuum environment, ethylene oxide gas sterilization, and gas plasma sterilization. For many of these alternative techniques, little clinical performance data exist. This study is a comparative evaluation of sterilization methods using the same analytic techniques that have been used to document the effects of gamma sterilization in air on polyethylene. Fourier transform infrared spectroscopy, electron spin resonance, and uniaxial tensile testing are used to compare, respectively, the oxidation levels, free radical concentration, and mechanical properties of material sterilized by each method. The polyethylene is evaluated before sterilization, poststerilization, and postartificial aging. All examined alternative sterilization methods, when compared with gamma sterilization in air, caused less material degradation during a component's preimplantation shelf life.     

An investigation of genital ulcers in Jackson, Mississippi, with use of a multiplex polymerase chain reaction assay: high prevalence of chancroid and human immunodeficiency virus infection

To test the hypothesis that the frequencies of normal alleles (ANs) with a relatively large number of CAG repeats (large ANs) are related to the prevalences of the dominant spinocerebellar ataxias (SCAs)-SCA types 1, 2, 3 (Machado-Joseph disease), 6, and dentatorubral-pallidoluysian atrophy (DRPLA)-we investigated the relative prevalences of these diseases in 202 Japanese and 177 Caucasian families and distributions of the number of CAG repeats of ANs at these disease loci in normal individuals in each population. The relative prevalences of SCA1 and SCA2 were significantly higher in Caucasian pedigrees (15% and 14%, respectively) than in Japanese pedigrees (3% and 5%, respectively), corresponding to the observation that the frequencies of large ANs of SCA1 (alleles >30 repeats) and of SCA2 (alleles >22 repeats) were significantly higher in Caucasians than in Japanese. The relative prevalences of MJD/SCA3, SCA6, and DRPLA were significantly higher in Japanese pedigrees (43%, 11%, and 20%, respectively) than in Caucasian pedigrees (30%, 5%, and 0%, respectively), corresponding to the observation that the frequencies of large ANs of MJD/SCA3 (>27 repeats), SCA6 (>13 repeats), and DRPLA (>17 repeats) were significantly higher in Japanese than in Caucasians. The close correlations of the relative prevalences of the dominant SCAs with the distributions of large ANs strongly support the assumption that large ANs contribute to generation of expanded alleles (AEs) and the relative prevalences of the dominant SCAs.     

Time-Dependent Solution to the Tai-Chou Chemical Vapor Infiltration Model

A recently proposed steady-state isothermal model for chemical vapor infiltration in parallel cylindrical pores has been extended to include transient behavior. Availability of a time-dependent solution should prove useful in comparison with experimental data and validation of the assumed boundary conditions. Attention is also drawn to analogous problems in the heat transfer literature which may prove useful in development of enhanced vapor infiltration models of this class.     

Three Basic Residues of Intracellular Loop 3 of the Beta-1 Adrenergic Receptor Are Required for Golgin-160-Dependent Trafficking

Golgin-160 is a member of the golgin family of proteins, which have been implicated in the maintenance of Golgi structure and in vesicle tethering. Golgin-160 is atypical; it promotes post-Golgi trafficking of specific cargo proteins, including the β-1 adrenergic receptor (β1AR), a G protein-coupled receptor. Here we show that golgin-160 binds directly to the third intracellular loop of β1AR and that this binding depends on three basic residues in this loop. Mutation of the basic residues does not affect trafficking of β1AR from the endoplasmic reticulum through the Golgi complex, but results in reduced steady-state levels at the plasma membrane. We hypothesize that golgin-160 promotes incorporation of β1AR into specific transport carriers at the trans-Golgi network to ensure efficient delivery to the cell surface. These results add to our understanding of the biogenesis of β1AR, and suggest a novel point of regulation for its delivery to the plasma membrane.