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Search Results: 1 - 10 of 462222 matches for " A. Baron "
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Associations with Organ Involvement and Autoantibodies in Systemic Sclerosis: Results from the Canadian Scleroderma Research Group (CSRG)  [PDF]
Vikram Tangri, Carly Hewson, Murray Baron, A. Bonner, Marvin Fritzler, Janet E. Pope
Open Journal of Rheumatology and Autoimmune Diseases (OJRA) , 2013, DOI: 10.4236/ojra.2013.32017
Abstract:

Objective: Serum from SSc patients was analyzed centrally to determine ANA patterns and extractable nuclear antigens (ENAs) between lcSSc and dcSSc and associations with organ involvement. Methods: 1145 SSc patients had ANA and ENA analyzed by indirect immunofluorescence on HEp-2 substrate at a screening serum dilution of 1/160. Most ENA antibodies [Sm. U1-RNP, Ro52, SS-A/Ro60, topoisomeraseI (Topo1), SS-B/La, chromatin, ribosomal P and Jo1] were measured by laser bead immunoassay; and RNA polymerase III (RNAP) by ELISA. Results: ANA was positive in 95% (same in lcSSc, and dcSSc). Centromere pattern was present in 34%, speckled 22%, nucleolar 18%, homogeneous and speckled (H&S) 16%, multiple nuclear dots 6%. Anti-centromere Ab (ACA) occurred in 46% of lcSSc and 11% of dcSSc (P = 0.0001). ENAs that differed between lcSSc and dcSSc subsets were Topo1 (OR 2.4, P = 0.0001) and RNAP (OR 5.6, P < 0.0001) more common in dcSSc. Overall, 15% had positive Topo1; usually with a H&S pattern (67%); Topo1 was associated with ILD on CXR (OR 2.3; 95% CI 1.5 - 3.5) and HRCT (OR 3.8; 95% CI 1.8 - 8.2). RNAP occurred in 18.5% (35.4% in dcSSc vs. 8.9% in lcSSc). Scleroderma renal crisis (SRC) was 13 times more likely if RNAP positive; P = 0.0001. ACA was only weakly associated with sPAP > 50 mmHg (OR 1.8; 95%CI 1.1 - 3.0). Conclusion: ANA homogeneous pattern alone is rare in SSc; ACA was significantly more common in lcSSc. Many ENAs are equal in lcSSc and dcSSc except RNAP and Topo1. RNAP has the highest OR of SRC. Topo1 is less strongly associated with ILD. Abstract word count: 249, Body word count 1246, Figures 2, Tables 2. Key Messages: 1) 95% of SSc has a positive ANA and ANA patterns in SSc include centromere, nucleolar, and homogeneous and speckled together; 2) Most ENAs are equal in both dcSSc and lcSSc except anti RNA polymerase III and topoisomerase I; 3) RNA polymerase III has the highest association (odds ratio) with scleroderma renal crisis, topoisomerase I is associated with interstitial lung disease; whereas anticentromere was not associated

Analysis of the kinetic mechanism of recombinant human isoprenylcysteine carboxylmethyltransferase (Icmt)
Rudi A Baron, Patrick J Casey
BMC Biochemistry , 2004, DOI: 10.1186/1471-2091-5-19
Abstract: In this study, we have investigated the kinetic mechanism of recombinant human Icmt. In the reaction catalyzed by Icmt, S-adenosyl-L-methionine (AdoMet) provides the methyl group that is transferred to the second substrate, the C-terminal isoprenylated cysteine residue of a CaaX protein, thereby generating a C-terminal prenylcysteine methyl ester on the protein. To facilitate the kinetic analysis of Icmt, we synthesized a new small molecule substrate of the enzyme, biotin-S-farnesyl-L-cysteine (BFC). Initial kinetic analysis of Icmt suggested a sequential mechanism for the enzyme that was further analyzed using a dead end competitive inhibitor, S-farnesylthioacetic acid (FTA). Inhibition by FTA was competitive with respect to BFC and uncompetitive with respect to AdoMet, indicating an ordered mechanism with SAM binding first. To investigate the order of product dissociation, product inhibition studies were undertaken with S-adenosyl-L-homocysteine (AdoHcy) and the N-acetyl-S-farnesyl-L-cysteine methylester (AFCME). This analysis indicated that AdoHcy is a competitive inhibitor with respect to AdoMet, while AFCME shows a noncompetitive inhibition with respect to BFC and a mixed-type inhibition with respect to AdoMet. These studies established that AdoHcy is the final product released, and that BFC and AFCME bind to different forms of the enzyme.These studies establish that catalysis by human Icmt proceeds through an ordered sequential mechanism and provide a kinetic framework for analysis of specific inhibitors of this key enzyme.Posttranslational modification of eukaryotic proteins with lipids is a prevalent mechanism for controlling the subcellular localization and activity of these proteins [1]. Most proteins terminating in a CaaX sequence (C, cysteine; "a", generally an aliphatic residue; X, the carboxy-terminal residue) are subject to modification by isoprenoid lipids via their ability to serve as substrates for protein farnesyltransferase or protein geranylgera
ANALYSIS OF FOREIGN DIRECT INVESTMENTS ENGAGED BY JAPANESE MULTINATIONAL COMPANIES
CODRU?A DURA,OANA DOBRE-BARON
Annals of the University of Petrosani : Economics , 2011,
Abstract: In recent years, the most visible feature of globalization was the new trend of the capital flow which moves from the stage of nternalization to the stage of transnationalization. The decisive factor that led to this development was the trans-nationalization of production/ distribution networks by multinational companies (MNCs). MNCs, which are also frequently referred to as transnational corporations (TNCs), are conglomerate organizations which carry out multiple and diverse economic activities and they consists of a parent company and a large number of subsidiaries operating in various countries of the world. Japan has been worthy of note on the international business scene not only by the high competitiveness of its companies on the global markets, but especially through the transnationalization of the activities of these enterprises, a process which has resulted in the implementation, via Foreign Direct Investments (FDI) of Japanese production units abroad, with significant positive impact both on the global economy and on the domestic economy. A great number of empirical studies since the mid-1990s, using firm-level data, have shown that multinational companies (MNCs) dominate today the Japanese business environment. The paper puts together the findings of some interesting working papers published by Japanese researchers in recent years, trying to provide a scientific answer to the following question: “In what way do FDI undertaken by MNCs influence the level of performances achieved by Japanese companies at home?” The conclusion is that FDI and the activity carried out by Japanese MNCs abroad have indubitable positive effects on both countries and firms involved - such as raises in production, employment and productivity at firms’ level or increases in competition intensity among firms, improvements in real wage and welfare at macroeconomic level.
The influence of Ni, Mo, Si, Ti on the surface alloy layer quality
A. Walasek,C. Baron,J. Szajnar
Archives of Foundry Engineering , 2011,
Abstract: The paper presents research results of microstructure and selected mechanical properties of alloy layer. The aim of the researches was to determine the influence of Ni, Mo, Si and Ti with high-carbon ferrochromium (added separately to pad) on the alloy layer on the steel cast. Metallographic studies were made with use of light microscopy. During studies of usable properties measurements of hardness, microhardness and abrasive wear resistance of type metal-mineral for creation alloy layer were made. As thick as possible composite layer without any defects and discontinuity was required. The conducted researches allowed to take the suitable alloy addition of the pad material which improved the quality of the surface alloy layer.
The influence of the size of ferrochromium grain on the surface composite layer forming process
J. Szajnar,C. Baron,A. Walasek
Archives of Foundry Engineering , 2010,
Abstract: The aim of the researches was to determine the influence of the size of high - carbon ferrochromium grain (which was used to make the pad) on the quality of the composite layer on the steel cast. This kind of cast was obtain by pouring the mould with the pad placed on the chosen surface with liquid metal. As thick as possible composite layer without any defects and discontinuity was required. Both good quality and required thickness of surface composite layer depend on many factors. The pouring temperature, module of cast solidification, size and shape of the cast are the most important ones. The suitable graininess of pad material is also significant parameter. The conducted researches allowed to take the suitable graininess of the pad material which improved the quality of the surface composite layer.
Selected manufacturing techniques of nanomaterials
A. Baron,D. Szewieczek,R. Nowosielski
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: Enabling nanofabrication techniques as tools for experiments to understand the underlying scienceand engineering in the nanometer scale are required. This paper is a resume a range of technology andcharacterization tools relevant for nanoeletronics devices.Design/methodology/approach: An overview on bottom – up and bottom – down fabrication techniques arepresented in this paper. As an alternative to the continually increasing cost of nanotechnology for manufacturingelectronic devices, new strategies are examined in research, which are based on basic principles of physics andchemistry. For example, molecular self-organization mechanisms are developed in order to manufacture welldefinednanostructures with desired properties.Findings: This paper includes description of three methods of production nanolayers and monolayers molecularself-organization, Langmuir – Blodget films and Nanoimprint Lithography.Research limitations/implications: The most extreme approach is to build nanostructures atom by atomwith the help of scanning tunneling microscope at low temperatures. This is very slow method to buildnanostructures, usually a couple of hours. An alternative approach for the formation of nanostructures is self– organization of atoms.Practical implications: The greatest advantage of litographic patterning is very large variety of differentstructures which can be defined by lithographic methods, Langmuir – Blodget (LB) films is another unpopularmethod to produce nanomaterials.Originality/value: Materials engineering technology stands today at the edge of a huge challenge: produce cheapnanomaterials for nanoelectronics. Building materials from the bottom up requires a multidisciplinary approach.This arena is unquestionably in the nano-dimension, where all fields of science and engineering meet.
EIS tests of electrochemical behaviour of Ti6Al4V and Ti6Al7Nb alloys
A. Baron,W. Simka,W. Chrzanowski
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: This study has been undertaken in order to establish the influence of parameters of the electrochemical treatment of Ti –alloys on their electrochemical behaviour in Tyrod solution.Design/methodology/approach: Surface of the Ti-alloys: Ti6Al4V and Ti6Al7Nb in the form of a rod submitted to grounding, electropolishing and anodic passivation. Electrochemical investigations were carried out by means of the electrochemical impedance spectroscopy method. Scope of this paper includes analysis of the impedance spectra based on Bode plot.Findings: Prolongation time of anodic passivation to 60 minutes caused formation of a two – layer model consisting of an inner layer which is compact and the barrier type, and outer layer which is porousResearch limitations/implications: Obtained results are the basis for the optimization of anodic passivation pareameters of the Ti alloys as a metallic biomaterial. The future research should be focused on selected more suitable parameters of the electrochemical impedance spectroscopy test to better describe process on the solid/ liquid interface.Practical implications: It has been found that a good resistance to corrosion and homogenous oxide layer on the Ti6Al4V and Ti6Al7Nb alloys surface can be achieved due to the application of electrolytic polishing of these alloys in a special bath and anodic passivation in sulphuric acid (VI), phosphoric acid (V) and inorganic salts.Originality/value: Results of the experiments presents the influence of various conditions of anodic passivation of the surface of the Ti6Al4V and Ti6Al7Nb alloy. In this cases, when the surface roughness plays important role, this method can be applied in treatment of the material intended for medical applications especially.
NLTE Modeling of SNe Ia Near Maximum Light
E. Baron,P. H. Hauschildt,A. Mezzacappa
Physics , 1995,
Abstract: Modeling the atmospheres of SNe~Ia requires the solution of the NLTE radiative transfer equation. We discuss the formulation of the radiative transfer equation in the co-moving frame. For characteristic velocities larger than about 2000 km/s, the effects of advection on the synthetic spectra are non-negligible, and hence should be included in model calculations. We show that the time-independent or quasi-static approximation is adequate for SNe~Ia near maximum light, as well as for most other astrophysical problems; e.g., hot stars, novae, and other types of supernovae. We examine the use of the Sobolev approximation in modeling moving atmospheres and find that the number of overlapping lines in the co-moving frame make the approximation suspect in models that predict both lines and continua. We briefly discuss the form of the Rosseland mean opacity in the co-moving frame, and present a formula that is easy to implement in radiation hydrodynamics calculations.
Change-Point Analysis of Survival Data with Application in Clinical Trials  [PDF]
Xuan Chen, Michael Baron
Open Journal of Statistics (OJS) , 2014, DOI: 10.4236/ojs.2014.49062
Abstract: Effects of many medical procedures appear after a time lag, when a significant change occurs in subjects’ failure rate. This paper focuses on the detection and estimation of such changes which is important for the evaluation and comparison of treatments and prediction of their effects. Unlike the classical change-point model, measurements may still be identically distributed, and the change point is a parameter of their common survival function. Some of the classical change-point detection techniques can still be used but the results are different. Contrary to the classical model, the maximum likelihood estimator of a change point appears consistent, even in presence of nuisance parameters. However, a more efficient procedure can be derived from Kaplan-Meier estimation of the survival function followed by the least-squares estimation of the change point. Strong consistency of these estimation schemes is proved. The finite-sample properties are examined by a Monte Carlo study. Proposed methods are applied to a recent clinical trial of the treatment program for strong drug dependence.
Angiotensin II-Rezeptorblockade im Vergleich zu ACE-Hemmung bei Patienten mit chronischem Nierenversagen
Rump LC,Andre M,Baron A,Dendorfer A
Journal für Hypertonie , 1999,
Abstract: Angiotensin-Converting-Enzym (ACE)-Hemmer verz gern die Progression des chronischen Nierenversagens [1-3]. Chronisches Nierenversagen ist durch ein aktiviertes sympathisches Nervensystem charakterisiert [4], welches zumindest im Herz durch Angiotensin (Ang) II-Rezeptor-Antagonisten besser unterdrückt wird als durch ACE-Hemmer [5]. Unsere Hypothese war, da Ang II Rezeptor-Antagonisten besser als ACE-Hemmer in bezug auf die Behandlung der Hypertonie von Patienten mit eingeschr nkter Nierenfunktion wirken. Die Patienten wurden in zwei Gruppen randomisiert und erhielten entweder Benazepril (10 mg, n = 9) oder Losartan (50 mg, n = 9). Proteinurie, Bradykinin im Urin, Ang II Plasma-Spiegel, Serum-Kreatinin, 24-Stunden-Blutdruck und die Lebensqualit t (Beltz-Test) wurden bei Einschlu sowie 4 und 24 Wochen nach Beginn der Studie erfa t. Der mittlere arterielle Blutdruck nach 0, 4 und 24 Wochen war 97 ± 3, 96 ± 3 and 95 ± 4 mmHg in der Benazepril- und 98 ± 4, 93 ± 1 und 90 ± 2 mmHg in der Losartan-Gruppe. Ang II-Spiegel stiegen unter Losartan und fielen unter Benazepril. Kein Unterschied fand sich bei der Bradykinin-Ausscheidung. Die Proteinurie fiel initial (4 Wochen) um 0,7 g/24 h in der Losartan-Gruppe und 1,2 g/24 h in der Benazepril-Gruppe, zeigte im Verlauf der Studie wieder eine steigende Tendenz. Parameter der Lebensqualit t stiegen in der Losartan-Gruppe leicht an und fielen in der Benazepril-Gruppe leicht ab. Beide Substanzen reduzierten vorübergehend die Proteinurie ohne negativen Effekt auf die Kreatinin-Clearance, die in beiden Gruppen stabil blieb. Tendenziell fanden sich eine bessere Lebensqualit t unter Ang II Rezeptor-Blockade.
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