40 research outputs found
On the central symmetry of the circumstellar envelope of RS Cnc
We present a phenomenological study of CO(1-0) and CO(2-1) emission from the
circumstellar envelope (CSE) of the Asymptotic Giant Branch (AGB) star RS\,Cnc.
It reveals departures from central symmetry that turn out to be efficient tools
for the exploration of some of the CSE properties. We use a wind model
including a bipolar flow with a typical wind velocity of 8 km\,s
decreasing to 2 km\,s near the equator to describe Doppler
velocity spectral maps obtained by merging data collected at the IRAM Plateau
de Bure Interferometer and Pico Veleta single dish radio telescope. Parameters
describing the wind morphology and kinematics are obtained, together with the
radial dependence of the gas temperature in the domain of the circumstellar
envelope probed by the CO observations. Significant north-south central
asymmetries are revealed by the analysis, which we quantify using a simple
phenomenological description. The origin of such asymmetries is unclear.Comment: accepted for publication in Research in Astronomy and Astrophysics
(RAA
Loi de comportement des composites BMC
L’objectif est l’obtention d’une loi de
comportement des composites BMC dont les coefficients sont fonction des propriétés des
constituants (la fraction volumique, la distribution d’orientation, la forme des
renforts). La démarche sera fondée sur une approche multi échelle d’homogénéisation des
milieux aléatoires. Les problèmes nouveaux qui se posent pour le BMC concernent la prise
en compte du comportement non linéaire de la matrice
Nutritional status and dietary intake before hospital admission of pulmonary tuberculosis patients
Conducting research on nutritional status and dietary intake of pulmonary tuberculosis patients is essential for developing interventions in clinical nutrition practice and treatment during hospitalization, which can improve the quality of patients life. This cross-sectional descriptive study aimed to determine nutritional status and some related factors (such as geography, occupation, educational level, economic classification, etc.) of 221 patients with pulmonary tuberculosis who were examined and treated at the Respiratory Tuberculosis Department, National Lung Hospital in July 2019–May 2020. The results showed that the risk of undernutrition: According to BMI (Body Mass Index): 45.8% of patients were malnourished, 44.2% normal and 10.0% overweight/obese. According to MUAC (Mid-Upper Arm Circumference): 60.2% of patients were malnourished, 39.8% of patients were normal. According to SGA (Subjective Global Assessment): 57.9% of patients were at risk of undernutrition, of which 40.7% were at moderate risk of undernutrition and 17.2% risk of severe undernutrition. Classification of nutritional status according to serum albumin index: 50% of patients were malnourished, the rate of undernutrition of mild, moderate and severe levels was 28.9%, 17.9% and 3.2%, respectively. Most patients eat with others and eat less than four meals a day. The average dietary energy of patients with pulmonary tuberculosis in was 1242.6 ± 46.5 Kcal and 1084 ± 57.9 Kcal, respectively. 85.52% of patients did not eat enough food, 4.07% had enough, 10.41% consumed excess energy. The ratio of energy-generating substances in the diet (Carbohydrate:Protein:Lipid) was on average 54:18:28 for males and 55:16:32 for females. Most of the study population had diets that did not meet the experimental study in terms of micronutrient content. Specifically, more than 90% do not meet the requirements for magnesium, calcium, zinc, and vitamin D. The water-soluble and fat-soluble vitamins respond poorly, only about 30–40%. Selenium is the mineral with the best response rate, above 70%. Our findings revealed that the majority of the study subjects had poor nutritional status, as evidenced by diets lacking in essential micronutrients
A Novel Thermostable Cytochrome P450 from Sequence-Based Metagenomics of Binh Chau Hot Spring as a Promising Catalyst for Testosterone Conversion
Biotechnological applications of cytochromes P450 show difficulties, such as low activity,
thermal and/or solvent instability, narrow substrate specificity and redox partner dependence. In an
attempt to overcome these limitations, an exploitation of novel thermophilic P450 enzymes from
nature via uncultured approaches is desirable due to their great advantages that can resolve nearly
all mentioned impediments. From the metagenomics library of the Binh Chau hot spring, an open
reading frame (ORF) encoding a thermostable cytochrome P450—designated as P450-T3—which
shared 66.6% amino acid sequence identity with CYP109C2 of Sorangium cellulosum So ce56 was
selected for further identification and characterization. The ORF was synthesized artificially and
heterologously expressed in Escherichia coli C43(DE3) using the pET17b system. The purified enzyme
had a molecular weight of approximately 43 kDa. The melting temperature of the purified enzyme
was 76.2 ◦C and its apparent half-life at 60 ◦C was 38.7 min. Redox partner screening revealed that
P450-T3 was reduced well by the mammalian AdR-Adx4-108 and the yeast Arh1-Etp1 redox partners.
Lauric acid, palmitic acid, embelin, retinoic acid (all-trans) and retinoic acid (13-cis) demonstrated
binding to P450-T3. Interestingly, P450-T3 also bound and converted testosterone. Overall, P450-T3
might become a good candidate for biocatalytic applications on a larger scale
Sterilization effect of UV light on Bacillus spores using TiO2 films depends on wavelength
UV light and photocatalysts such as titanium dioxide (TiO2) and silver (Ag) are useful for disinfection of water and surfaces. However, the effect of UV wavelength on photocatalytic disinfection of spores is not well understood. Inactivation of Bacillus spores has been examined using different UV wavelengths and TiO2 or TiO2/Ag composite materials. The level of UVA disinfection of Bacillus anthracis and Bacillus brevis vegetative cells increased with the presence of the TiO2 and Ag photocatalysts, but had little effect on their spores. B. brevis spores were slightly more sensitive to UVB and UVC than the spores of B. atrophaeus. Photocatalytic sterilization against spores was strongest in UVC and UVB and weakest in UVA. The rate of inactivation of Bacillus spores was significantly increased by the presence of TiO2, but was not markedly different from that induced by the presence of Ag. Therefore, TiO2/Ag plus UVA can be used for the sterilization of vegetative cells, while TiO2 and UVC are effective against spores
Association of apolipoprotein E polymorphism with plasma lipid disorders, independent of obesity-related traits in Vietnamese children
Composites BMC injectés : analyse et modélisation multi-échelles du comportement endommageable
Schneider Electric is developing technical parts used in the area of Low Voltage Power, medium voltage and industrial control. These parts are highly constrained in terms of dielectric, mechanical and thermal properties. This study is carried out on BMC materials (Bulk Molding Compound), applied in electrical industry and expected to answer all the properties mentioned before. In general, all the BMC composites are based on polyester resin used with low shrink additive and mineral fillers. One can obtain different properties by the method of processing and varying the amount or the nature of each component of the formulation. The design of pieces and the choice of the composite materials allow us to reach the main properties expected for such application. The main objective of Schneider Electric is to create a tool for the design of these BMC pieces, describing their mechanical properties as a function of the proposed formulation. We have proposed an approach to establish a numerical model allowing us to predict the behavior of BMC composites based on the properties of each constituent of the formulation. The proposed approach is based on a multi-scale homogenization of random media. The experimental results allowed us to determine precisely the micro-structure of the materials and its influence on the macroscopic scale (mechanical properties). They have permitted us to highlight the specificities of this class of materials. The results are integrated into a model of Mori-Tanaka type, coupled with the inclusion of damages like the formation of voids growth and the debonding of fibers.Les pièces élaborées par le groupe Schneider Electric sont principalement utilisées dans les domaines de la Basse Tension de Puissance, la Moyenne Tension et le Contrôle Industriel et fortement contraintes sur les plans diélectrique, mécanique et thermique. Cette étude traite des matériaux de type BMC appliqués dans l'industrie électrotechnique pour répondre à ces besoins. Si les BMC sont tous élaborés à base de résine polyester, d'un agent anti retrait, et de charges et renforts minéraux, ils diffèrent entre eux par le choix du procédé de fabrication mais aussi par la nature et la proportion de chacun des constituants du mélange. La conception des pièces et le choix du matériau composite permettant de remplir les fonctions principales demandées à une pièce ne sont donc pas triviaux et s'appuient encore largement sur un savoir-faire empirique. L'objectif de Schneider Electric est donc de disposer à terme d'un outil d'aide à la conception des pièces en décrivant les propriétés mécaniques des BMC en fonction de leur formulation et en optimisant ensuite le choix du matériau composite en fonction du cahier des charges demandé. Nous proposons ici de mettre en place les éléments nécessaires à l'établissement d'un modèle prédictif permettant de déduire la loi de comportement des composites BMC en fonction des propriétés de ses constituants. La démarche proposée est fondée sur une approche multi échelle d'homogénéisation des milieux aléatoires. Une analyse expérimentale complète nous permet de déterminer de manière précise la microstructure du matériau, son influence sur les propriétés mécaniques macroscopiques mais aussi de mettre en évidence les spécificités de cette classe de matériaux. Les résultats sont ensuite intégrés dans un modèle de type Mori-Tanaka élastique couplé à la prise en compte de l'endommagement par croissance de cavités et décohésion de fibres
Etudes des enzymes de réplication coronavirus : assemblage, mécanisme et inhibition
Mon projet de doctorat décrit dans cette thèse était la caractérisation structurale et fonctionnelle de l'ARN polymérase du SARS-CoV complexe. Nous avons reconstitué un RTC hautement actif avec l’ARN polymérase dépendante de l’ARN nsp12 purifiée individuellement et son facteur de processivité nsp7-nsp8. En utilisant des analyses biochimiques, nous montrons que ce complexe de polymérase présente une faible fidélité sans l’aide de l’activité d’excision de l’Exonucléase (ExoN) de nsp14. Le SARS-CoV semble utiliser un mécanisme unique de correction de l’ARN impliquant le RdRp nsp12 et l’ExoN nsp14 qui n’a jamais été décrit dans aucun virus à ARN. Il montre également que ce complexe est capable de catalyser la formation de liaisons phosphodiester à un rythme plus rapide que tout autre RdRp viral connu à ce jour, ainsi qu’avec des taux d’erreur élevés pour l’incorporation du NTP, en particulier pour l’UTP. Le RTC du SARS-CoV incorpore facilement les 5’- triphosphates de Ribavirine, de 5-Fluorouracil et de de-fluoro Favipiravir-ribose dans l’ARN. Étant donné que l’exonucléase nsp14 est capable d’éliminer à la fois les mésappariements de l’extrémité 3’ et les analogues nucléotidiques, nos résultats suggèrent que les meilleures propriétés anti-SARS-CoV peuvent être obtenues avec des nucléotides mutagènes qui ne sont pas discriminés le site actif de nsp12. L’absence de traitement médicamenteux efficace contre les CoVs souligne la nécessité d’élucider leurs mécanismes de réplication et d’identifier des cibles médicamenteuses potentielles pour le traitement de l’infection par les CoVs. Notre résultat pourrait ouvrir la voie à la mise au point de nouveaux antiviraux contre ce virus.My PhD project described in this thesis was the structural and functional characterization of the SARS-CoV RNA polymerase complex.We first reconstitute a highly active RTC with individually purified RNA dependent RNA polymerase (RdRp) nsp12 and its processive factor nsp7-nsp8. By using biochemical assays, we show that this polymerase complex exhibits low fidelity without the help of Exonuclease (ExoN) excision activity of nsp14. SARS-CoV seems to use a unique RNA proofreading mechanism involving the RdRp nsp12 and the ExoN nsp14 that has never been described in any RNA virus. It also shows that this complex is able to catalyze phosphodiester bond formation at a faster rate than any other viral RdRp known so far, as well as with high error rates for NTP incorporation, in particular for UTP. The SARS- CoV RTC readily incorporates 5’-triphosphates of Ribavirin, 5-Fluorouracil, and de-fluoro Favipiravir-ribose into RNA. Since the nsp14 exonuclease is able to remove both 3’- terminus mismatches and nucleotide analogues, our results suggest that best anti-SARS-CoV properties may be achieved with mutagenic nucleotides that are not discriminated at the nsp12 active-site.The lack of effective drug treatment against CoVs highlights the need for elucidating their replication mechanisms and identifying potential drug targets for treatment of CoVs infection. Our result may pave the way to develop new antivirals against this virus
Composites BMC injectés : analyse et modélisation multi-échelles du comportement endommageable
Schneider Electric is developing technical parts used in the area of Low Voltage Power, medium voltage and industrial control. These parts are highly constrained in terms of dielectric, mechanical and thermal properties. This study is carried out on BMC materials (Bulk Molding Compound), applied in electrical industry and expected to answer all the properties mentioned before. In general, all the BMC composites are based on polyester resin used with low shrink additive and mineral fillers. One can obtain different properties by the method of processing and varying the amount or the nature of each component of the formulation. The design of pieces and the choice of the composite materials allow us to reach the main properties expected for such application. The main objective of Schneider Electric is to create a tool for the design of these BMC pieces, describing their mechanical properties as a function of the proposed formulation. We have proposed an approach to establish a numerical model allowing us to predict the behavior of BMC composites based on the properties of each constituent of the formulation. The proposed approach is based on a multi-scale homogenization of random media. The experimental results allowed us to determine precisely the micro-structure of the materials and its influence on the macroscopic scale (mechanical properties). They have permitted us to highlight the specificities of this class of materials. The results are integrated into a model of Mori-Tanaka type, coupled with the inclusion of damages like the formation of voids growth and the debonding of fibers.Les pièces élaborées par le groupe Schneider Electric sont principalement utilisées dans les domaines de la Basse Tension de Puissance, la Moyenne Tension et le Contrôle Industriel et fortement contraintes sur les plans diélectrique, mécanique et thermique. Cette étude traite des matériaux de type BMC appliqués dans l'industrie électrotechnique pour répondre à ces besoins. Si les BMC sont tous élaborés à base de résine polyester, d'un agent anti retrait, et de charges et renforts minéraux, ils diffèrent entre eux par le choix du procédé de fabrication mais aussi par la nature et la proportion de chacun des constituants du mélange. La conception des pièces et le choix du matériau composite permettant de remplir les fonctions principales demandées à une pièce ne sont donc pas triviaux et s'appuient encore largement sur un savoir-faire empirique. L'objectif de Schneider Electric est donc de disposer à terme d'un outil d'aide à la conception des pièces en décrivant les propriétés mécaniques des BMC en fonction de leur formulation et en optimisant ensuite le choix du matériau composite en fonction du cahier des charges demandé. Nous proposons ici de mettre en place les éléments nécessaires à l'établissement d'un modèle prédictif permettant de déduire la loi de comportement des composites BMC en fonction des propriétés de ses constituants. La démarche proposée est fondée sur une approche multi échelle d'homogénéisation des milieux aléatoires. Une analyse expérimentale complète nous permet de déterminer de manière précise la microstructure du matériau, son influence sur les propriétés mécaniques macroscopiques mais aussi de mettre en évidence les spécificités de cette classe de matériaux. Les résultats sont ensuite intégrés dans un modèle de type Mori-Tanaka élastique couplé à la prise en compte de l'endommagement par croissance de cavités et décohésion de fibres
Hvilken betydning har håp og sosial kognisjon for bedring ved schizofreni? : Målt de første 18 måneder av forløpet
Bakgrunn: Personlige beretninger fra restituerte eller remitterte personer som har fått diagnosen schizofreni, fremhever håp og sosiale relasjoner som viktige bidrag i sin bedringsprosess. Håp beskrives her som en utløsende og opprettholdende motivasjonsfaktor. Mange pasienter mener at sosial støtte er avgjørende for bedring, blant annet ved å opprettholde håp. Sosial fungering og utfall er videre blitt knyttet til sosial kognisjon. Det synes derfor nærliggende å tenke seg at sosial kognisjon kan bidra til økt sosial støtte, og dermed opprettholdelse av håp. Imidlertid er det lite empirisk forskning på hvordan håp relaterer seg til remisjon og restitusjon. Sosial kognisjon er også et relativt nytt forskningsområde, og det etterlyses mer kunnskap om hvordan sosial kognisjon relaterer seg til schizofreni. Vi har derfor undersøkt hvorvidt håp og/eller sosial kognisjon bidrar til ulikheter i forløp ved schizofreni. Metode: Voksne over 18 år med førstegangspsykose (n = 17) ble vurdert med mål på håp og sosial kognisjon. Symptomendring vurderes ut i fra skårer på The Structured Clinical Interview for The Positive and Negative Syndrome Scale (SCI-PANSS). Data er samlet inn ved 0, 6 og 18 måneder. Resultater: Signifikante sammenhenger ble funnet mellom håp og symptomendring, der håp øker i etterkant av symptomlette (r = -.637). Den første tiden har positive symptomer størst signifikant unikt bidrag til håp ( = -.609), deretter har negative symptomer størst unikt bidrag til håp (β = - .503). Endring i sosial kognisjon korrelerer med endring i positive symptomer (r = -.488). Håp og sosial kognisjon korrelerer signifikant kun ved baseline (r = .668). Konklusjon: Vi fant ikke støtte for at grad av håp og sosial kognisjon bidrar til ulikheter i individuelle forløp. Håp synes å komme som en følge av symptomlette. Sosial kognisjon endrer seg i samsvar med positive symptomer, der høyt symptomtrykk gir nedgang i sosial kognitive evner