396 research outputs found

    Design of the Target Dump Injection Segmented (TDIS) in the framework of the High Luminosity Large Hadron Collider (HL-LHC) project

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    The High Luminosity Large Hadron Collider (HL-LHC) Project at CERN calls for increasing beam brightness and intensity. In this scenario, most equipment has to be redesigned and rebuilt. In particular, beam intercepting devices (such as dumps, collimators, absorbers and scrapers) have to withstand impact or scraping of the new intense HL-LHC beams without failure. Furthermore, minimizing the electromagnetic beam-device interactions is also a key design driver since they can lead to beam instabilities and excessive thermo-mechanical loading of devices. In this context, the present study assesses the conceptual design quality of the new LHC injection protection absorber, the Target Dump Injection Segmented (TDIS), from an electromagnetic and thermo-mechanical perspective. This contribution analyzes the thermo-mechanical response of the device considering two cases: an accidental beam impact scenario and another accidental scenario with complete failure of the RFcontacts. In addition, this paper presents the preliminary results from the simulation of the energy deposited by the two counter-rotating beams circulating in the device

    Inversion of the anomeric configuration of the transferred sugar during inactivation of the macrolide antibiotic oleandomycin catalyzed by a macrolide glycosyltransferase

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    AbstractMacrolides are a group of antibiotics structurally characterized by a macrocyclic lactone to which one or several deoxy-sugar moieties are attached. The sugar moieties are transferred to the different aglycones by glycosyltransferases (GTF). The OleI GTF of an oleandomycin producer, Streptomyces antibioticus, catalyzes the inactivation of this macrolide by glycosylation. The product of this reaction was isolated and its structure elucidated. The donor substrate of the reaction was UDP-α-D-glucose, but the reaction product showed a β-glycosidic linkage. The inversion of the anomeric configuration of the transferred sugar and other data about the kinetics of the reaction and primary structure analysis of several GTFs are compatible with a reaction mechanism involving a single nucleophilic substitution at the sugar anomeric carbon in the catalytic center of the enzyme

    One Anastomosis/Mini-Gastric Bypass (OAGB/MGB) as Revisional Surgery Following Primary Restrictive Bariatric Procedures: a Systematic Review and Meta-Analysis

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    One anastomosis gastric bypass (OAGB/MGB) has gained popularity in the past decade. International databases were searched for articles published by September 10, 2020, on OAGB/MGB as a revisional procedure after restrictive procedures. Twenty-six studies examining a total of 1771 patients were included. The mean initial BMI was 45.70 kg/m2, which decreased to 31.52, 31.40, and 30.54 kg/m2 at 1, 3, and 5-year follow-ups, respectively. Remission of type-2 diabetes mellitus (T2DM) following OAGB/MGB at 1-, 3-, and 5-year follow-up was 65.16 ± 24.43, 65.37 ± 36.07, and 78.10 ± 14.19%, respectively. Remission/improvement rate from gastroesophageal reflux disease (GERD). Also, 7.4% of the patients developed de novo GERD following OAGB/MGB. Leakage was the most common major complication. OAGB/MGB appears to be feasible and effective as a revisional procedure after failed restrictive bariatric procedures

    Collective excitations in liquid D2 confined within the mesoscopic pores of a MCM-41 molecular sieve

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    We present a comparative study of the excitations in bulk and liquid D2 confined within the pores of MCM-41. The material (Mobile Crystalline Material-41) is a silicate obtained by means of a template that yields a partially crystalline structure composed by arrays of nonintersecting hexagonal channels of controlled width having walls made of amorphous SiO2. Its porosity was characterized by means of adsorption isotherms and found to be composed by a regular array of pores having a narrow distribution of sizes with a most probable value of 2.45 nm. The assessment of the precise location of the sample within the pores is carried out by means of pressure isotherms. The study was conducted at two pressures which correspond to pore fillings above the capillary condensation regime. Within the range of wave vectors where collective excitations can be followed up (0.3<Q<3.0 A˚\AA&#8722;1), we found confinement brings forward a large shortening of the excitation lifetimes that shifts the characteristic frequencies to higher energies. In addition, the coherent quasielastic scattering shows signatures of reduced diffusivity.Comment: 6 page

    Identification of novel drought-tolerant-associated SNPs in common bean (Phaseolus vulgaris)

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    Common bean (Phaseolus vulgaris L.) is a leguminous in high demand for human nutrition and a very important agricultural product. Production of common bean is constrained by environmental stresses such as drought. Although conventional plant selection has been used to increase production yield and stress tolerance, drought tolerance selection based on phenotype is complicated by associated physiological, anatomical, cellular, biochemical, and molecular changes. These changes are modulated by differential gene expression. A common method to identify genes associated with phenotypes of interest is the characterization of Single Nucleotide Polymorphims (SNPs) to link them to specific functions. In this work, we selected two drought-tolerant parental lines from Mesoamerica, Pinto Villa, and Pinto Saltillo. The parental lines were used to generate a population of 282 families (F3:5) and characterized by 169 SNPs. We associated the segregation of the molecular markers in our population with phenotypes including flowering time, physiological maturity, reproductive period, plant, seed and total biomass, reuse index, seed yield, weight of 100 seeds, and harvest index in three cultivation cycles. We observed 83 SNPs with significant association (p < 0.0003 after Bonferroni correction) with our quantified phenotypes. Phenotypes most associated were days to flowering and seed biomass with 58 and 44 associated SNPs, respectively. Thirty-seven out of the 83 SNPs were annotated to a gene with a potential function related to drought tolerance or relevant molecular/biochemical functions. Some SNPs such as SNP28 and SNP128 are related to starch biosynthesis, a common osmotic protector; and SNP18 is related to proline biosynthesis, another well-known osmotic protector

    Spatio-temporal dynamics of dengue 2009 outbreak in Córdoba city, Argentina.

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    During 2009 the biggest dengue epidemic to date occurred in Argentina, affecting almost half the country. We studied the spatio-temporal dynamics of the outbreak in the second most populated city of the country, Córdoba city. Confirmed cases and the results of an Aedes aegypti monitoring during the outbreak were geolocated. The imported cases began in January, and the autochthonous in March. Thirty-three percent of the 130 confirmed cases were imported, and occurred mainly at the center of the city. The autochthonous cases were more frequent in the outskirts, specially in the NE and SE. Aedes aegypti infestation showed no difference between neighborhoods with or without autochthonous cases, neither between neighborhoods with autochthonous vs. imported cases. The neighborhoods with imported cases presented higher population densities. The majority of autochthonous cases occurred at ages between 25 and 44 years old. Cases formed a spatio-temporal cluster of up to 20 days and 12 km. According to a athematical model that estimates the required number of days needed for transmission according to daily temperature, the number of cases begun to fall when more than 15.5 days were needed. This may be a coarse estimation of mean mosquito survival in the area, provided that the study area is close to the global distribution limit of the vector, and that cases prevalence was very low.Fil: Estallo, Elizabet Lilia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Investigaciones Entomológicas de Córdoba; ArgentinaFil: Carbajo, Anibal Eduardo. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Grech, Marta Gladys. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Departamento de Biología. Laboratorio de Investigaciones en Ecología y Sistemática Animal; ArgentinaFil: Frias Cespedes, M.. Ministerio de Salud de la Provincia de Córdoba; ArgentinaFil: Lopez, L.. Ministerio de Salud de la Provincia de Córdoba; ArgentinaFil: Lanfri, M. A.. Comision Nacional de Actividades Espaciales; ArgentinaFil: Ludueña Almeida, Francisco F.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Investigaciones Entomológicas de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Almiron, Walter Ricardo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Investigaciones Entomológicas de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas; Argentin

    The first survey addressing patients with BMI over 50: a survey of 789 bariatric surgeons

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    Background: Bariatric surgery in patients with BMI over 50 kg/m2 is a challenging task. The aim of this study was to address main issues regarding perioperative management of these patients by using a worldwide survey. Methods: An online 48-item questionnaire-based survey on perioperative management of patients with a BMI superior to 50 kg/m2 was ideated by 15 bariatric surgeons from 9 different countries. The questionnaire was emailed to all members of the International Federation of Surgery for Obesity (IFSO). Responses were collected and analyzed by the authors. Results: 789 bariatric surgeons from 73 countries participated in the survey. Most surgeons (89.9%) believed that metabolic/bariatric surgery (MBS) on patients with BMI over 50 kg/m2 should only be performed by expert bariatric surgeons. Half of the participants (55.3%) believed that weight loss must be encouraged before surgery and 42.6% of surgeons recommended an excess weight loss of at least 10%. However, only 3.6% of surgeons recommended the insertion of an Intragastric Balloon as bridge therapy before surgery. Sleeve Gastrectomy (SG) was considered the best choice for patients younger than 18 or older than 65 years old. SG and One Anastomosis Gastric Bypass were the most common procedures for individuals between 18 and 65 years. Half of the surgeons believed that a 2-stage approach should be offered to patients with BMI > 50 kg/m2, with SG being the first step. Postoperative thromboprophylaxis was recommended for 2 and 4 weeks by 37.8% and 37.7% of participants, respectively. Conclusion: This survey demonstrated worldwide variations in bariatric surgery practice regarding patients with a BMI superior to 50 kg/m2. Careful analysis of these results is useful for identifying several areas for future research and consensus building

    One Anastomosis/Mini-Gastric Bypass (OAGB/MGB) as Revisional Surgery Following Primary Restrictive Bariatric Procedures: a Systematic Review and Meta-Analysis

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    One anastomosis gastric bypass (OAGB/MGB) has gained popularity in the past decade. International databases were searched for articles published by September 10, 2020, on OAGB/MGB as a revisional procedure after restrictive procedures. Twenty-six studies examining a total of 1771 patients were included. The mean initial BMI was 45.70 kg/m2, which decreased to 31.52, 31.40, and 30.54 kg/m2 at 1, 3, and 5-year follow-ups, respectively. Remission of type-2 diabetes mellitus (T2DM) following OAGB/MGB at 1-, 3-, and 5-year follow-up was 65.16 ± 24.43, 65.37 ± 36.07, and 78.10 ± 14.19, respectively. Remission/improvement rate from gastroesophageal reflux disease (GERD). Also, 7.4 of the patients developed de novo GERD following OAGB/MGB. Leakage was the most common major complication. OAGB/MGB appears to be feasible and effective as a revisional procedure after failed restrictive bariatric procedures. © 2020, The Author(s)
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