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See detailInvestigation of the interactions of polyvinylpyrrolidone with mixtures of anionic and nonionic surfactants or anionic and zwitterionic surfactants by pulsed field gradient NMR
Misselyn-Bauduin, Anne-Marie; Thibaut, André ULg; Grandjean, Jean ULg et al

in Journal of Colloid & Interface Science (2001), 238(1), 1-7

The interaction of polyvinylpyrrolidone (PVP) with an anionic surfactant (sodium dodecyl sulfate, SDS), a nonionic surfactant (pentaethylene glycol monodecyl ether, C(10)E(5)), and a zwitterionic ... [more ▼]

The interaction of polyvinylpyrrolidone (PVP) with an anionic surfactant (sodium dodecyl sulfate, SDS), a nonionic surfactant (pentaethylene glycol monodecyl ether, C(10)E(5)), and a zwitterionic surfactant (lauryl amido propyl betaine, LAPB) has been investigated by means of pulsed gradient spin-echo NMR (FT-PGSE NMR), allowing self-diffusion coefficients to be determined. The results confirm the strong interaction prevailing in the PVP/SDS system, whereas no association has been observed in the PVP/C(10)E(5) and PVP/LAPB systems. Mixing PVP with two surfactants, namely SDS and C(10)E(5) or SDS and LAPB, results in the formation of ternary aggregates between the polymer and the mixed micelles. [less ▲]

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See detailAn investigation of the large-scale variability of the apparently single Wolf-Rayet star WR 1
Morel, Thierry ULg; Georgiev, L. N.; Grosdidier, Y. et al

in Astronomy and Astrophysics (1999), 349

In recent years, much studies have focused on determining the origin of the large-scale line-profile and/or photometric patterns of variability displayed by some apparently single Wolf-Rayet stars, with ... [more ▼]

In recent years, much studies have focused on determining the origin of the large-scale line-profile and/or photometric patterns of variability displayed by some apparently single Wolf-Rayet stars, with the existence of an unseen (collapsed?) companion or of spatially extended wind structures as potential candidates. We present observations of <ASTROBJ>WR 1</ASTROBJ> which highlight the unusual character of the variations in this object. Our narrowband photometric observations reveal a gradual increase of the stellar continuum flux amounting to Delta v ~ 0.09 mag followed by a decline on about the same timescale (3-4 days). Only marginal evidence for variability is found during the 11 following nights. Strong, daily line-profile variations are also observed but they cannot be easily linked to the photometric variations. Similarly to the continuum flux variations, coherent time-dependent changes are observed in 1996 in the centroid, equivalent width, and skewness of He Ii lambda 4686. Despite the generally coherent nature of the variations, we do not find evidence in our data for the periods claimed in previous studies. While the issue of a cyclical pattern of variability in <ASTROBJ>WR 1</ASTROBJ> is still controversial, it is clear that this object might constitute in the future a cornerstone for our understanding of the mechanisms leading to the formation of largely anisotropic outflows in Wolf-Rayet stars. [less ▲]

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See detailAn Investigation of the Late Excitatory Potentials in the Hand following Transcranial Magnetic Stimulation in Early Alzheimer's Disease.
Balla, christina; PEPIN, Jean-Louis ULg; MAERTENS DE NOORDHOUT, Alain ULg

in Dementia & Geriatric Cognitive Disorders (2014), 4

BACKGROUND: Recent neuroimaging studies in humans support the clinical observations that the motor cortex is affected early in the course of Alzheimer's disease (AD). PATIENTS AND METHODS: We measured the ... [more ▼]

BACKGROUND: Recent neuroimaging studies in humans support the clinical observations that the motor cortex is affected early in the course of Alzheimer's disease (AD). PATIENTS AND METHODS: We measured the silent period (SP) induced by transcranial magnetic stimulation in AD patients in the very early stage of the disease, and we explored whether and in which way the pharmacologic manipulation of the cholinergic system could modify it. RESULTS: An increase in the duration of the SP was observed in AD patients in the early stage in comparison to controls. After 2 months of treatment with donepezil, the duration did not differ significantly from that of normal subjects. The results of our study show a fragmentation and an enlargement of the SP in the presence of multiple late excitatory potentials (LEPs) in early untreated AD patients. These LEPs were also modulated by donepezil. CONCLUSIONS: The results suggest an early functional impairment of cholinergic neurotransmission in AD. The disturbance in acetylcholine output in early AD leads to a decrease in excitability of the motor system. [less ▲]

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See detailInvestigation of the links between mass transfer conditions, dissolved hydrogen concentration and biohydrogen production by the pure strain Clostridium butyricum CWBI1009
Beckers, L.; Masset, J.; Hamilton, C. et al

in Biochemical Engineering Journal (2015), 98

Fermentative hydrogen production has often been described as inhibited by its own gas production. In this work, hydrogen production by Clostridium butyricum was investigated in batch Biochemical Hydrogen ... [more ▼]

Fermentative hydrogen production has often been described as inhibited by its own gas production. In this work, hydrogen production by Clostridium butyricum was investigated in batch Biochemical Hydrogen Potential (BHP) tests and in a 2.5L anaerobic sequenced batch reactor (AnSBR) under different operating conditions regarding liquid-to-gas mass transfer. Through the addition of both stirring up to 400rpm and nitrogen sparging, the yields were enhanced from 1.6 to 3.1molH2molglucose -1 and the maximum hydrogen production rates from 140 to 278mLh-1. These original results were achieved with a pure Clostridium strain. They showed that hydrogen production was improved by a higher liquid-to-gas hydrogen transfer resulting in a lower dissolved hydrogen concentration in the culture medium and therefore in a lower bacterial inhibition. In addition, biohydrogen partitioning between the gas and the liquid phase did not conform to Henry's Law due to critical supersaturation phenomena up to seven-fold higher than the equilibrium conditions. Therefore, dissolved hydrogen concentration should be systematically measured instead of the headspace hydrogen partial pressure. A model was proposed to correlate H2 production yield and rate by the pure C. butyricum strain CWBI1009 with mass transfer coefficient KLa. [less ▲]

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See detailInvestigation of the physics of wind interactions in colliding-wind massive binaries through XMS high resolution X-ray spectroscopy
De Becker, Michaël ULg

Conference (2011, June 14)

Binary systems made of two massive stars offer the opportunity to investigate the physics of quite extreme stellar environments. The powerful stellar winds collide, producing so-called wind interaction ... [more ▼]

Binary systems made of two massive stars offer the opportunity to investigate the physics of quite extreme stellar environments. The powerful stellar winds collide, producing so-called wind interaction regions, and the shocked gas is heated up to temperatures that can reach values as high as several tens of MK, leading to the production of copious amounts of thermal X-rays. The properties of the X-ray spectrum of such systems are intimately related to the orbitally modulated physical conditions in the wind interaction region. The study of the hydrodynamics of the colliding-wind phenomenon is a crucial issue in the sense that it constitutes the basement for the study of higher level physical processes at work in these systems, such as particle acceleration or even dust production. High-resolution X-ray spectroscopy with ATHENA/XMS is undoubtedly expected to be the most powerful tool to probe the physics of such environments over the next two decades, allowing a detailed confrontation to state-of-the-art theoretical models aiming at simulating the complex physics of colliding-wind massive binaries (CWBs). [less ▲]

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See detailInvestigation of the preparation and activity of gold catalysts in the total oxidation of n-hexane
Cellier Caroline; Lambert, Stéphanie ULg; Gaigneaux Eric et al

Poster (2005, June)

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See detailInvestigation of the preparation and activity of gold catalysts in the total oxidation of n-hexane
Cellier Caroline; Lambert, Stéphanie ULg; Gaigneaux Eric et al

in Applied Catalysis B : Environmental (2007), 70

The factors affecting the preparation of Au/TiO2 catalysts and their activity in the total oxidation of n-hexane were investigated. The mechanism of gold deposition–precipitation is discussed through ... [more ▼]

The factors affecting the preparation of Au/TiO2 catalysts and their activity in the total oxidation of n-hexane were investigated. The mechanism of gold deposition–precipitation is discussed through comparison of the samples prepared by this method and others prepared by anion adsorption method. The influence of the pH and of the origin of TiO2 support used are additionally addressed. The difference of gold dispersion observed between the two methods is attributed to a difference of mobility of the gold precursors during the thermal treatment rather than to a difference of dispersion over the uncalcined samples. The mechanism of gold deposition–precipitation actually involves the reactions of gold hydroxy-chloride species with the surface. Another part of the work, thus, concerned the use of the deposition–precipitation method to prepare a Au/MnO2 catalyst. It is shown that the activity of g-MnO2 is directly proportional to its surface area and that the deposition–precipitation procedure decreases the surface and activity of MnO2. However, the deposition of gold allows to avoid a too deep sintering of g-MnO2 and, thus, helps to somehow preserve its activity. [less ▲]

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See detailInvestigation of the preparation and activity of gold catalysts in the total oxidation of n-hexane
Cellier, Caroline; Lambert, Stéphanie ULg; Gaigneaux, Eric M. et al

in Applied Catalysis B : Environmental (2007), 70(1-4), 406-416

The factors affecting the preparation of Au/TiO2 catalysts and their activity in the total oxidation of n-hexane were investigated. The mechanism of gold deposition-precipitation is discussed through ... [more ▼]

The factors affecting the preparation of Au/TiO2 catalysts and their activity in the total oxidation of n-hexane were investigated. The mechanism of gold deposition-precipitation is discussed through comparison of the samples prepared by this method and others prepared by anion adsorption method. The influence of the pH and of the origin of TiO2 support used are additionally addressed. The difference of gold dispersion observed between the two methods is attributed to a difference of mobility of the gold precursors during the thermal treatment rather than to a difference of dispersion over the uncalcined samples. The mechanism of gold deposition-precipitation actually involves the reactions of gold hydroxy-chloride species with the surface. Another pan of the work, thus, concerned the use of the deposition-precipitation method to prepare a Au/MnO2 catalyst. It is shown that the activity of gamma-MnO2 is directly proportional to its surface area and that the deposition-precipitation procedure decreases the surface and activity of MnO2. However, the deposition of gold allows to avoid a too deep sintering of gamma-MnO2 and, thus, helps to somehow preserve its activity. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailInvestigation of the range and effective factors on protein energy malnutrition based on nutritional classification of rural zone of Arak in children less than five years
Jafarinia; Faraz, Alireza ULg; Akhoundzadeh, Sh. et al

in Arak Medical University Journal (2003), 6(2(23)), 7-13

Introduction: The protein-energy malnutrition is the most prevalent cause of malnutrition and always occures in infants and children under 5 years old. According to the harmful effects of malnutrition ... [more ▼]

Introduction: The protein-energy malnutrition is the most prevalent cause of malnutrition and always occures in infants and children under 5 years old. According to the harmful effects of malnutrition, such as high mortality, inability of learning and decrease of mental and physical ability, reconnoite and study of malnutrition qualification is very important. Material and Methods: This analytic cross-sectional study was carried out on 811 children under 5 years old who were living in rural zone of Arak. Based on health files; clinical inspections and interview with mothers a checklist was fulfilled for every child. Data were analysed by EPI6 software. Results: In this study, none of the children had stricken with Kwashiorkor or Marasmic-Kwashiorkor. Undernourished were seen in 7.39% and Marasmus were also seen in 1.1 % of subjects. The prevalence of malnutrition was 7.5% in Wellcome, 33.55% in Waterlow-Stunting, 23.05% in Waterlow-Wasting and 30.94% in Gomez classification. There was statistically correlation between malnutririon and respiratory infection rate, milstones, birthweight, maturity and begning of helpfood (P<0.05). Conclusion: Considering the results, the most rate of malnutrition in each classification was mild. It is suggested that increasing of familial awareness is an important factor for preventing from next damages and additional treatment costs. [less ▲]

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See detailInvestigation of the Relationship between Osteoporosis and the Collagenase Gene by Means of Polymorphism of the 5'upstream Region of This Gene
Thiry-Blaise, L. M.; Taquet, A. N.; Reginster, Jean-Yves ULg et al

in Calcified Tissue International (1995), 56

Osteoporosis is a slowly progressing disease resulting from an imbalance between bone accretion and degradation. As interstitial collagenase is a key enzyme in the degradation of bone matrix, we ... [more ▼]

Osteoporosis is a slowly progressing disease resulting from an imbalance between bone accretion and degradation. As interstitial collagenase is a key enzyme in the degradation of bone matrix, we investigated a possible relationship between the collagenase gene and osteoporosis. Analysis of an amplified genomic DNA fragment from -524 to +52 by denaturing gradient gel electrophoresis and sequencing allowed us to detect three dimorphic sites upstream of base -300, one of them leading to a BanI restriction site. None of the sites could be directly associated with osteoporosis. The allele frequencies of the three dimorphic sites were estimated. The interallelic ratios were high, thus providing new useful genetic markers for linkage analysis. When comparing these ratios in osteoporotic and nonosteoporotic subjects, no significant differences could be observed. [less ▲]

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See detailAn investigation of the relationships between foot conformation and distal interphalangeal joint effusion in young warmblood horses at the beginning of their training
Cubeddu, Francesca; Bastianacci, Valentina; Verwilghen, Denis et al

Poster (2011)

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See detailInvestigation of the Separation of Ternary Mixtu¬res Forming Two Liquid Phases by Distillation
Keil, B; Paul, H I; Pfennig, Andreas ULg et al

in International Chemical Engineering (1994)

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See detailInvestigation of the stellar content in the western part of the Carina nebula
Kumar, Brajesh; Sharma, Saurabh; Manfroid, Jean ULg et al

in Astronomy and Astrophysics (2014), 567

Context. The low obscuration and proximity of the Carina nebula make it an ideal place to study the ongoing star formation process and impact of massive stars on low-mass stars in their surroundings. <BR ... [more ▼]

Context. The low obscuration and proximity of the Carina nebula make it an ideal place to study the ongoing star formation process and impact of massive stars on low-mass stars in their surroundings. <BR /> Aims: To investigate this process, we generated a new catalog of the pre-main-sequence stars in the Carina west (CrW) region and studied their nature and spatial distribution. We also determined various parameters (reddening, reddening law, age, mass), which are used further to estimate the initial mass function and K-band luminosity function for the region under study. <BR /> Methods: We obtained deep UBVRI Hα photometric data of the field situated to the west of the main Carina nebula and centered on WR 22. Medium-resolution optical spectroscopy of a subsample of X-ray selected objects along with archival data sets from Chandra, XMM-Newton and 2MASS surveys were used for the present study. Different sets of color-color and color-magnitude diagrams are used to determine reddening for the region and to identify young stellar objects (YSOs) and estimate their age and mass. <BR /> Results: Our spectroscopic results indicate that the majority of the X-ray sources are late spectral type stars. The region shows a large amount of differential reddening with minimum and maximum values of E(B - V) as 0.25 and 1.1 mag, respectively. Our analysis reveals that the total-to-selective absorption ratio R[SUB]V[/SUB] is ~3.7 ± 0.1, suggesting an abnormal grain size in the observed region. We identified 467 YSOs and studied their characteristics. The ages and masses of the 241 optically identified YSOs range from ~0.1 to 10 Myr and ~0.3 to 4.8 M[SUB]⊙[/SUB], respectively. However, the majority of them are younger than 1 Myr and have masses below 2 M[SUB]⊙[/SUB]. The high mass star WR 22 does not seem to have contributed to the formation of YSOs in the CrW region. The initial mass function slope, Γ, in this region is found to be -1.13 ± 0.20 in the mass range of 0.5 < M/M[SUB]⊙[/SUB] < 4.8. The K-band luminosity function slope (α) is also estimated as 0.31 ± 0.01. We also performed minimum spanning tree analysis of the YSOs in this region, which reveals that there are at least ten YSO cores associated with the molecular cloud, and that leads to an average core radius of 0.43 pc and a median branch length of 0.28 pc. Full Table 3 is only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/567/A109">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/567/A109</A> [less ▲]

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See detailInvestigation of the surface activity of a poly(styrene-b-dimethylsiloxane) copolymer blended within a polystyrene matrix
Petitjean, Serge; Ghitti, G.; Jérôme, Robert ULg et al

in Macromolecules (1994), 27

The surface properties of thin polystyrene films are deeply modified by the addition of various amounts of a poly(styrene-b-dimethylsiloxane) copolymer-or poly(S-b-DMS)-as confirmed by a series of ... [more ▼]

The surface properties of thin polystyrene films are deeply modified by the addition of various amounts of a poly(styrene-b-dimethylsiloxane) copolymer-or poly(S-b-DMS)-as confirmed by a series of analytical methods. In addition to the surface tension which has been estimated from wettability and contact angle measurements, surface composition has been analyzed by X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). Surface studies have been completed by the analysis of the depth distribution of siloxane from the surface by XPS and SIMS. Finally, the surface activity of poly(S-b-DMS) has been investigated in solution. Indeed, changes in the surface tension of polystyrene solutions in THF have been measured in relation to the addition of the diblock copolymer. All the experimental data agree with the complete coverage of the polystyrene films with the poly(S-b-DMS) copolymer. This situation already prevails in the solutions prepared as precursors to the thin polystyrene films. Accordingly, surface characteristics of film freshly prepared by solvent-casting are unaffected by subsequent annealing. [less ▲]

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See detailInvestigation of the susceptibility of human cell lines to bovine herpesvirus 4 infection: Demonstration that human cells can support a nonpermissive persistent infection which protects them against tumor necrosis factor alpha-induced apoptosis
Gillet, Laurent ULg; Minner, F.; Detry, Bruno et al

in Journal of Virology (2004), 78(5), 2336-2347

Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus that has a worldwide distribution in the population of cattle. Many factors make human contamination by BoHV-4 likely to occur. In this study, we ... [more ▼]

Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus that has a worldwide distribution in the population of cattle. Many factors make human contamination by BoHV-4 likely to occur. In this study, we performed in vitro experiments to assess the risk and the consequences of human infection by BoHV-4. First, by using a recombinant BoHV-4 strain expressing enhanced green fluorescent protein under the control of the human cytomegalovirus immediate-early gene promoter, we tested 21 human cell lines for their sensitivity and their permissiveness to BoHV-4 infection. These experiments revealed that human cell lines from lymphoid and myeloid origins were resistant to infection, whereas epithelial cells, carcinoma cells, or adenocarcinoma cells isolated from various organs were sensitive but poorly permissive to BoHV-4 infection. Second, by using the HeLa cell line as a model of human cells sensitive but not permissive to BoHV-4 infection, we investigated the resistance of infected cells to apoptosis and the persistence of the infection through cellular divisions. The results obtained can be summarized as follows. (i) BoHV-4 nonpermissive infection of HeLa cells protects them against tumor necrosis factor alpha-induced apoptosis. (ii) BoHV-4 infection of HeLa cells persists in cell culture; however, the percentage of infected cells decreases with time due to erratic transmission of the viral genome through cell division. (iii) BoHV-4 infection has no effect on the rate of HeLa cell division. Altogether, these data suggest that BoHV-4 could infect humans. This study also stresses the importance of considering the insidious effects of nonpermissive infection when the biosafety of animal gammaherpesviruses for humans is being considered. [less ▲]

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See detailInvestigation of the thermal and structural behavior of two lauric fats in bulk and oil-in-water emulsion states
Petrut, Raul Flaviu ULg; Anihouvi, Prudent Placide; Blecker, Christophe ULg et al

Poster (2014, September 14)

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