Search results for "Stein"
showing 10 items of 1448 documents
Hepatitis C virus co-infection and sexual risk behaviour are associated with a high homocysteine serum level in HIV-infected patients.
2012
BACKGROUND AND AIMS: A better understanding of the relationship of homocysteine with cardiovascular risk factors is needed. The objectives of this study were to assess the serum level of homocysteine in HIV-infected patients and to analyse the possible association of increased levels of the amino acid with cardiovascular risk factors, demographic and clinical characteristics of participants. METHODS: Cross-sectional study carried out as a supplementary task to the usual controls necessary in HIV-infected patients in the outpatient clinic of the Hospital General of Castellon, Spain. For two consecutive visits the demographic, clinical and HIV-related characteristics and blood analyses result…
Manipulation of optical solitons in Bose-Einstein condensates
2004
We propose a method to control the optical transparency of a Bose-Einstein condensate with working energy levels of the Lambda-type. The reported effects are essentially nonlinear and are considered in the framework of an exactly solvable model describing the interaction of light with a Lambda-type medium. We show how the complicated nonlinear interplay between fast and slow solitons in the $\Lambda$-type medium points to a possibility to create optical gates as well as to a possibility to store optical information.
Studies of Quantum Chromodynamics with the ALEPH Detector
1998
Previously published and as vet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and non-perturbative aspects of strong interactions to be carried out using hadronic Z and tau decays. The studies presented include precise determinations of the strong coupling constant. tests of its flavour independence, tests of the SU(3) gauge structure of QCD, study of coherence effects, and measurements of single-particle inclusive distributions and two-particle correlations for many identified baryons and mesons. (C) 1998 Elsevier Science B.V.
In situ forming hydrogels of new amino hyaluronic acid/benzoyl-cysteine derivatives as potential scaffolds for cartilage regeneration
2012
A new chemical strategy is described to link ethylenediamino (EDA) groups to primary hydroxyl groups of hyaluronic acid (HA) and the obtained derivatives have been characterized by 1H-NMR and 13C-NMR analyses. Such HA–EDA derivatives have been exploited to control the functionalization degree in benzoyl-cysteine (BC) groups, chosen as moieties able to allow both self-assembling in aqueous media and an oxidative crosslinking. In particular, the kinetics of oxidation of thiol groups in HA–EDA–BC derivatives has been studied in Dulbecco's Phosphate Buffer Solution (DPBS) pH 7.4 by colorimetric assays and rheological measurements. Mechanical properties of chemical hydrogels obtained after oxida…
Sosiaalinen media ja verkko-opiskelu
2010
Koskelainen, Tiina Elina Tietojärjestelmätieteen kandidaatintutkielma / Tiina Koskelainen Jyväskylä: Jyväskylän yliopisto, 2009, 39 s. Kandidaatintutkielma Tässä tutkimuksessa kartoitetaan sosiaalisen median ominaispiirteitä sekä oppimisen ja verkko-opiskelun käsitteitä. Lisäksi tutkitaan millaisia vaikutuksia sosiaalisen median käytöllä on verkko-opiskeluun. Tutkimus on toteutettu kirjallisuuskatsauksena. Tieto- ja viestintäteknologian nopea kehitys, vuorovaikutukseen perustuvat kommunikointitavat sekä sosiaaliset sovellukset ovat lisänneet yhteisöllisyyttä ja mahdollistaneet sosiaalisen median kehittymisen. Käyttäjälähtöisyys, verkostoituminen ja uudet kommunikointitavat ovat muuttaneet …
Negative pressure cavitation extraction and antioxidant activity of genistein and genistin from the roots of pigeon pea [Cajanus cajan (L.) Millsp.]
2010
Abstract A new method—negative pressure cavitation extraction (NPCE) was proposed and investigated for the extraction of the main isoflavonoids, namely genistein and genistin from pigeon pea roots. The effects of extraction time and particle size on the extraction yields were firstly optimized, then a central composite design (CCD) combined with response surface methodology (RSM) was used to study the effects of negative pressure, ethanol concentration and liquid/solid ratio on the extraction yields. The maximum extraction yields of genistein and genistin reached 0.418 and 0.398 mg/g, respectively, under the optimal conditions: extraction time 45 min, particle size 50 mesh, negative pressur…
Differential cysteine depletion in respiratory chain complexes enables the distinction of longevity from aerobicity.
2010
Mitochondrially encoded proteins in long-lived animals exhibit a characteristic anomaly on the amino acid usage level: they abstain from the use of cysteine in a lifespan-dependent fashion. Here, we have further investigated this phenomenon by analyzing respiratory chain complex subunits individually. We find that complex I cysteine depletion is the almost exclusive carrier of the cysteine-lifespan correlation, whereas complex IV cysteine depletion is uniform in all aerobic animals, unrelated to longevity, but even more pronounced than complex I cysteine depletion in the longest-lived species. In nuclear encoded subunits of the respiratory chain, we find lifespan-independent cysteine deplet…
Effect of oral glutathione on hepatic glutathione levels in rats and mice
1989
Administration of oral glutathione (GSH) increases hepatic GSH levels in fasted rats, in mice treated with GSH depletors such as diethyl maleate and in mice treated with high doses of paracetamol. An increase in hepatic GSH levels after administration of oral GSH does not occur in animals treated with buthionine sulphoximine, an inhibitor of GSH synthesis. Administration of oral GSH leads to an increase in the concentration of l-cysteine, a precursor of GSH, in portal blood plasma. Oral administration of l-methionine produced a significant decrease of hepatic ATP in fasted rats, but not in fed rats. Administration ofN−acetylcysteine or GSH did not affect the hepatic ATP levels. The results …
Folate, related B vitamins, and homocysteine in childhood and adolescence: potential implications for disease risk in later life.
2009
OBJECTIVES. Folate and the metabolically related B vitamins are an important priority throughout life, but few studies have examined their status through childhood and adolescence. The aims of the current study were to investigate age, gender, and lifestyle factors as determinants of folate, related B-vitamin status, and homocysteine concentrations among British children and adolescents and to propose age-specific reference ranges for these biomarkers, which, at present, are unavailable. PARTICIPANTS AND METHODS. Data from the National Dietary and Nutritional Survey of 2127 young people aged 4 to 18 years were accessed to provide a representative sample of British children. All of the subje…
NADA: A new code for studying self-gravitating tori around black holes
2008
We present a new two-dimensional numerical code called Nada designed to solve the full Einstein equations coupled to the general relativistic hydrodynamics equations. The code is mainly intended for studies of self-gravitating accretion disks (or tori) around black holes, although it is also suitable for regular spacetimes. Concerning technical aspects the Einstein equations are formulated and solved in the code using a formulation of the standard 3+1 (ADM) system, the so-called BSSN approach. A key feature of the code is that derivative terms in the spacetime evolution equations are computed using a fourth-order centered finite difference approximation in conjunction with the Cartoon metho…