606 research outputs found

    The dynamical evolution of the circumstellar gas around low-and intermediate-mass stars I: the AGB

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    We have investigated the dynamical interaction of low- and-intermediate mass stars (from 1 to 5 Msun) with their interstellar medium (ISM). In this first paper, we examine the structures generated by the stellar winds during the Asymptotic Giant Branch (AGB) phase, using a numerical code and the wind history predicted by stellar evolution. The influence of the external ISM is also taken into account. We find that the wind variations associated with the thermal pulses lead to the formation of transient shells with an average lifetime of 20,000 yr, and consequently do not remain recorded in the density or velocity structure of the gas. The formation of shells that survive at the end of the AGB occurs via two main processes: shocks between the shells formed by two consecutive enhancements of the mass-loss or via continuous accumulation of the material ejected by the star in the interaction region with the ISM. Our models show that the mass of the circumstellar envelope increases appreciably due to the ISM material swept up by the wind (up to 70 % for the 1 Msun stellar model). We also point out the importance of the ISM on the deceleration and compression of the external shells. According to our simulations, large regions (up to 2.5 pc) of neutral gas surrounding the molecular envelopes of AGB stars are expected. These large regions of gas are formed from the mass-loss experienced by the star during the AGB evolution.Comment: 43 pages, 15 figures. Accepted for publication in the Astrophysical Journa

    Cinética de inactivación térmica de Salmonella sp. en jugo de fresa, Fragaria sp.

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    Se determinó la cinética de termodestrucción de Salmonella sp. a temperaturas de 50, 55 y 60°C en jugo de fresa, Fragaria sp. Se reactivó el cultivo bacteriano y ajustó a una turbidez equivalente al 9 x 108 células/mL. Luego, se licuó 300 g de frutos maduros de fresa con 800 mL de agua destilada; previa filtración, se depositó el jugo en recipiente estéril y fue pasteurizado a 80°C por 5 minutos. Cada sistema de ensayo fue acondicionó en un matraz de vidrio de 250 mL con 90 mL de jugo pasteurizado y 10 mL de inóculo bacteriano estandarizado y sometido luego a temperatura de 50°C en baño maría. Desde el tiempo 0 y cada 2 minutos, hasta los 6 minutos, se extrajo una alícuota de 1 mL de muestra, se hizo diluciones con solución salina estéril y sembró 1 mL de la dilución por incorporación en Agar Nutritivo, e incubó a 35°C por 18 horas, y los recuentos bacterianos se expresaron en UFC/ml. Este procedimiento se repitió tres veces consecutivas; asímismo, para las temperaturas de 55 y 60°C. Con los datos obtenidos se representó las curvas de supervivencia de la bacteria (UFC/ml) en relación al tiempo de exposición, se determinó la velocidad de muerte térmica de la bacteria y los valores D para cada temperatura de evaluación. La población de Salmonella sp. en jugo de Frugaria sp. fue reducida y destruida en mayor proporción a medida que se incrementó la temperatura con un valor D promedio de 2 minutos.Palabras clave: Cinética, Termodestrucción, Valor D, Salmonella sp,  Fragaria spp

    Recursos hospitalarios y letalidad por infarto de miocardio. Estudio IBERICA

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    [Abstract] Introduction and objectives. To determine the proportion of patients with myocardial infarction (MI) not admitted to a coronary care unit (CCU), the variables associated with admission into a CCU, and whether admission to a CCU, and the availability of coronary angiography in the same hospital, were associated with 28-day case fatality. Patients and method. Population-based registry of MI in patients 25 to 74 years of age, admitted during 1996-1998. Demographic and clinical characteristics were recorded, as well as management, clinical course and survival after 28 days. Hospitals were classified according to the availability of a CCU and catheterization laboratory (advanced hospital), CCU only (intermediate hospital) or neither (basic hospital). Admission to the CCU was also recorded. Results. In all, 9046 cases of MI were recorded; in 11.3% the patient was not admitted to a CCU. Age, smoking (OR=1.33; 95% CI, 1.08-1.64), non-Q MI (OR=0.62; 95% CI, 0.49-0.78) or undetermined location of MI (OR=0.34; 95% CI, 0.23-0.50), Killip 4 score on admission (OR=0.63; 95% CI, 0.40-1.00) and delay in arrival at the hospital >6 h were associated with CCU admission. Patients admitted to a CCU showed a lower case fatality in the first 24 h (4.2% vs 23.5%), which was independent of comorbidity, severity and treatment. The 24-hour survivors admitted to a basic hospital had higher case fatality (17.3% vs 7.8%) than other groups, which was related to differences in treatment. Conclusions. CCU admission is associated with a lower case fatality in the first 24 h. Admission to a basic hospital is associated with a higher 28-day case fatality even in patients who survive 24 h.[Resumen] Introducción y objetivos. Determinar el porcentaje de pacientes con infarto agudo de miocardio (IAM) que no ingresan en una unidad de cuidados intensivos coronaries (UCIC), las variables asociadas al ingreso en una UCIC y si el ingreso en una UCIC, su disponibilidad y la de hemodinámica en el hospital se asocian a la letalidad a 28 días. Pacientes y método. Registro poblacional (1996-1998) de casos de IAM en pacientes con edades comprendidas entre los 25 y los 74 años. Se recogieron variables demográficas, clínicas, el ingreso en UCIC y la letalidad a los 28 días. Se clasificaron los hospitales según la disponibilidad de UCIC y hemodinámica (hospital avanzado), solamente UCIC (hospital intermedio) o ninguno (hospital básico). Resultados. Se registraron 9.046 casos; el 11,3% no ingresó en una UCIC. La edad, el consumo de tabaco (odds ratio [OR] = 1,33; intervalo de confianza [IC] del 95%, 1,08-1,64), el infarto sin onda Q (OR = 0,62; IC del 95%, 0,49-0,78) o ilocalizable (OR = 0,34; IC del 95%, 0,23-0,50), el grado Killip 4 al ingreso (OR = 0,63; IC del 95%, 0,40-1,00) y el retraso > 6 h en llegar al hospital se asociaron al ingreso en UCIC. Los pacientes ingresados en UCIC presentaban menor letalidad que los ingresados en hospitales básicos en las primeras 24 h (el 4,2 frente al 23,5%), independientemente de la gravedad del IAM y de las variables relacionadas con el tratamiento. Los su-pervivientes a 24 h que ingresaban en un hospital bÁsico presentaban mayor letalidad a los 28 días (el 17,3 frente al 7,8%), relacionada con las variables de tratamiento. Conclusiones. El ingreso en una UCIC se asocia a una menor letalidad de los pacientes con IAM en las primeras 24 h. El ingreso en un hospital bÁsico se asocia a una mayor letalidad a los 28 días.Insituto de Salud Carlos III; FIS96/0026-01 to 05Insituto de Salud Carlos III; FIS97/1270Insituto de Salud Carlos III; FIS98/153

    Steroid hormone-related polymorphisms associate with the development of bone erosions in rheumatoid arthritis and help to predict disease progression: Results from the REPAIR consortium

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    Here, we assessed whether 41 SNPs within steroid hormone genes associated with erosive disease. The most relevant finding was the rheumatoid factor (RF)-specific effect of the CYP1B1, CYP2C9, ESR2, FcγR3A, and SHBG SNPs to modulate the risk of bone erosions (P = 0.004, 0.0007, 0.0002, 0.013 and 0.015) that was confirmed through meta-analysis of our data with those from the DREAM registry (P = 0.000081, 0.0022, 0.00074, 0.0067 and 0.0087, respectively). Mechanistically, we also found a gender-specific correlation of the CYP2C9rs1799853T/T genotype with serum vitamin D3 levels (P = 0.00085) and a modest effect on IL1β levels after stimulation of PBMCs or blood with LPS and PHA (P = 0.0057 and P = 0.0058). An overall haplotype analysis also showed an association of 3 ESR1 haplotypes with a reduced risk of erosive arthritis (P = 0.009, P = 0.002, and P = 0.002). Furthermore, we observed that the ESR2, ESR1 and FcγR3A SNPs influenced the immune response after stimulation of PBMCs or macrophages with LPS or Pam3Cys (P = 0.002, 0.0008, 0.0011 and 1.97•10−7). Finally, we found that a model built with steroid hormone-related SNPs significantly improved the prediction of erosive disease in seropositive patients (PRF+ = 2.46•10−8) whereas no prediction was detected in seronegative patients (PRF− = 0.36). Although the predictive ability of the model was substantially lower in the replication population (PRF+ = 0.014), we could confirm that CYP1B1 and CYP2C9 SNPs help to predict erosive disease in seropositive patients. These results are the first to suggest a RF-specific association of steroid hormone-related polymorphisms with erosive disease

    Psychometric Properties and factor structure of the spanish version of the HC-PAIRS questionnaire

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    Objective To develop a Spanish version of the Health Care Providers" Pain and Impairment Relationship Scale (HC-PAIRS) and to test its psychometric properties. Methods A forward and backward translation methodology was used to translate the questionnaire, which was then applied to 206 participants (174physiotherapy students and 32 family physicians). The intraclass correlation coefficient was calculated to assess testretest reliability. Internal consistency was evaluated using Cronbach"s alpha and item analysis. Construct validity was measured using Pearson correlation coefficients between HC-PAIRS and FABQ, FABQ-Phys, FABQ-Work and the responses given by participants to three clinical case scenarios. An exploratory factor analysis was carried out following the Kaiser normalization criteria and principal axis factoring with an oblique rotation (quartimax). Sensitivity to change was assessed after a teaching module. Results Testretest reliability was ICC 0.50 (p\0.01)and Cronbach"s alpha was 0.825. The HC-PAIRS scores correlated significantly with the scores of the FABQ and also with the recommendations for work and activity given by the participants in the three clinical case scenarios. Sensitivity to change test showed an effect size of 1.5, which is considered a large change. Factor analysis suggests that the Spanish version of HC-PAIRS measures a unidimensional construct. Conclusion The Spanish version of the HC-PAIRS has proven to be a reliable, valid and sensitive instrument to assess health care providers" attitudes and beliefs about LBP. It can be used in evaluating clinical practice and in undergraduate acquisition of skills and knowledge

    The N-Terminal residues 43 to 60 form the interface for dopamine mediated α-synuclein dimerisation

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    α-synuclein (α-syn) is a major component of the intracellular inclusions called Lewy bodies, which are a key pathological feature in the brains of Parkinson's disease patients. The neurotransmitter dopamine (DA) inhibits the fibrillisation of α-syn into amyloid, and promotes α-syn aggregation into SDS-stable soluble oligomers. While this inhibition of amyloid formation requires the oxidation of both DA and the methionines in α-syn, the molecular basis for these processes is still unclear. This study sought to define the protein sequences required for the generation of oligomers. We tested N- (α-syn residues 43-140) and C-terminally (1-95) truncated α-syn, and found that similar to full-length protein both truncated species formed soluble DA: α-syn oligomers, albeit 1-95 had a different profile. Using nuclear magnetic resonance (NMR), and the N-terminally truncated α-syn 43-140 protein, we analysed the structural characteristics of the DA:α-syn 43-140 dimer and α-syn 43-140 monomer and found the dimerisation interface encompassed residues 43 to 60. Narrowing the interface to this small region will help define the mechanism by which DA mediates the formation of SDS-stable soluble DA:α-syn oligomers

    Breast and Prostate Cancer Risks for Male BRCA1 and BRCA2 Pathogenic Variant Carriers Using Polygenic Risk Scores

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    Background: Recent population-based female breast cancer and prostate cancer polygenic risk scores (PRS) have been developed. We assessed the associations of these PRS with breast and prostate cancer risks for male BRCA1 and BRCA2 pathogenic variant carriers. Methods: 483 BRCA1 and 1318 BRCA2 European ancestry male carriers were available from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). A 147-single nucleotide polymorphism (SNP) prostate cancer PRS (PRSPC) and a 313-SNP breast cancer PRS were evaluated. There were 3 versions of the breast cancer PRS, optimized to predict overall (PRSBC), estrogen receptor (ER)-negative (PRSER-), or ER-positive (PRSER+) breast cancer risk. Results: PRSER+ yielded the strongest association with breast cancer risk. The odds ratios (ORs) per PRSER+ standard deviation estimates were 1.40 (95% confidence interval [CI] =1.07 to 1.83) for BRCA1 and 1.33 (95% CI = 1.16 to 1.52) for BRCA2 carriers. PRSPC was associated with prostate cancer risk for BRCA1 (OR = 1.73, 95% CI = 1.28 to 2.33) and BRCA2 (OR = 1.60, 95% CI = 1.34 to 1.91) carriers. The estimated breast cancer odds ratios were larger after adjusting for female relative breast cancer family history. By age 85 years, for BRCA2 carriers, the breast cancer risk varied from 7.7% to 18.4% and prostate cancer risk from 34.1% to 87.6% between the 5th and 95th percentiles of the PRS distributions. Conclusions: Population-based prostate and female breast cancer PRS are associated with a wide range of absolute breast and prostate cancer risks for male BRCA1 and BRCA2 carriers. These findings warrant further investigation aimed at providing personalized cancer risks for male carriers and informing clinical management.Peer reviewe
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