MC3D-3D continuum radiative transfer, Version 2

A revised and greatly improved version of the 3D continuum radiative transfer code MC3D is presented. It is based on the Monte Carlo method and solves the radiative transfer problem self-consistently. It is designed for the simulation of dust temperatures in arbitrary geometric configurations and the resulting observables: spectral energy distributions, wavelength-dependent images, and polarization maps. The main objective is the investigation of “dust-dominated” astrophysical systems such as young stellar objects surrounded by an optically thick circumstellar disk and an optically thin(ner) envelope, debris disks around more evolved stars, asymptotic giant branch stars, the dust component of the interstellar medium, and active galactic nuclei.     

A comparative study of color measurement lntstrumentation

A multiplant Quality Improvement Team [QIT] was firmed to develop and implement an evaluation program for various color measurement .systems as potential replacements for the then-current aging systems. The emphasis qf this article is the analytical methodology utilized to evaluate the various color systems. The evaluation program consisted cf two phases. Phase I was a general overview/review of several systems, while Phase II was an extensive internal comparative evaluation measurement systems. These were Milton-Roy's ColorMate HDS, HunterLab's Ultrascan, Datacolor's CS-5, and BYK-Gardner's The Color Sphere [TCS]. The main comparison criteria were interinstrument agreement [agreement between two instruments ofthe same system], user-friendly software and computer interface capability, vendor amenability to a long-term logistical and maintenance relationship, and price. All systems were evaluated by duplicate measurements on various color tiles, yarns, and polymer flakes-over 1600 measurements on each system. The systems were compared with an instrument matrix, a decision matrix, and a product matrix. The instrument matrix was a comparison qfinstrument parameters, software/math treatments, and economics. The decision matrix was a forced ranking of each system by each criteria category [1–4 scale, with 1 representing the best and 4 representing the worst]. The product matrix accentuated the relative importance ofone criterion category over another by multiplying the forced ranking by the criticality of the category. The criticality of a given category wus determined by consensus within the QIT. Thr combination qf the three matrices allowed the evaluator[.s] t o select the color rneasuremmt system that best satixfied the color measurement needs and requirements of their facility and their products. For this evaluation, all ofthe evaluated systems were superior to the then-current agingsystems. As a result of this methodology, one instrument emerged as clearly superior. © 1994 John Wrley & Sons, Inc.     

Photo induced hydrogen evolution from water in the presence of EDTA and a supported catalyst

A flow reaction system was developed to study the steady state kinetics of hydrogen evolution in the presence of Ru(bipy)²⁺, MV⁺², EDTA and a heterogeneous supported catalyst. Under the conditions used, steady state rates similar to those previously reported with colloidal Pt particles were attained. Furthermore, over much of the range of concentrations used, the reaction was zero order and it did not exhibit an Arrhenius behavior. Examination of the various rate determining steps involved led us to conclude that surface processes such as the recombination and desorption of hydrogen from the Pt surface might be rate determining.     

Reversible nephrotic syndrome in Crohn's disease complicated with renal amyloidosis

A 24-year-old woman suffered from ano-rectal Crohn's disease and nephrotic syndrome due to glomerular amyloidosis AA. She received azathioprine and colchicine for two years. Both Crohn's disease and nephrotic syndrome resolved. However amyloid renal lesions were still present. This course is exceptional, and leads to a discussion of the treatment of amyloidosis associated with Crohn's disease.     

Patterns of messenger RNA expression for alpha1-adrenoceptor subtypes in human corpus cavernosum

PURPOSE: The present study evaluated the expression of alpha1-adrenoceptor subtypes in human corpus cavernosum. MATERIALS AND METHODS: The mRNA encoding alpha1a, alpha1b and alpha1d subtypes were assessed by RNA-directed complementary cDNA synthesis followed by Taq DNA amplification. The level of alpha1 mRNA was calculated in arbitrary optical density units and normalized with respect to the length of the respective cDNA fragments. RESULTS: We found that alpha1a, alpha1b and alpha1d adrenoceptor subtypes are expressed in human corpus cavernosum, with a predominant expression of the alpha1a subtype. CONCLUSION: These results suggest that alpha1a-adrenoceptor subtype is important and that understanding the biochemical and functional characteristics of this subtype may lead to the development of specific antagonists in the treatment of impotence.     

Reading epilepsy: report of five new cases and further considerations on the pathophysiology

Liposomes, microscopic lipid vesicles consisting of concentric phospholipid bilayers enclosing discrete aqueous spaces, have been investigated extensively as carries for drugs in attempts to achieve selective deposition and/or reduced toxicity. Liposomes radiolabeled with gamma emitters (67Ga, 111In and 99mTc) have been used for imaging purposes. Liposomes as formulated in the past, are rapidly taken up by cells of the mononuclear phagocyte system, primarily those located in liver and spleen. However, it has been shown during the last two decades that the in vivo behavior of liposomes can be modulated by modifying their formulation. The size and the lipid composition have a major influence on the blood clearance rate, hepatic uptake and splenic uptake of liposomes. The development of long circulating liposomes, in particular coating of the bilayer with polyethyleneglycol (PEG) resulted in liposomes that oppose recognition by the MPS, thus displaying even longer circulatory half-lives. By carefully adjusting the liposomal formulation, the in vivo characteristics of liposomes can be tailored such that they become suitable vehicles for imaging various pathological processes in vivo. Liposomes have been proposed for tumor imaging, for infection imaging and as blood pool markers. Here, the factors that determine the in vivo behavior of liposomes and the current status of liposome-based radiopharmaceuticals are reviewed.     

In vivo roles of receptor tyrosine kinases and cytokine receptors in early thymocyte development

The early phases of T-cell development require both cell-cell interactions and soluble factors provided by stromal cells within the thymic microenvironment. Still, the precise nature of the signals delivered in vivo by cytokines (resulting in survival, proliferation or differentiation) remains unclear. Recent studies using mice deficient in cytokines or in their receptors have helped to identify essential signaling pathways required for the development of intrathymic precursors to mature alpha beta and gamma delta T cells. In addition, cytokine requirements for the development of natural killer cells were revealed in such mutants. The results obtained demonstrate that the development of all classes of lymphocytes (natural killer, gamma delta T cells and alpha beta T cells) is cytokine dependent, but the specific requirements differ for each lineage.