44 research outputs found

    Elemental abundances differences in the massive planet-hosting wide binary HD 196067-68

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    It has been suggested that small chemical anomalies observed in planet-hosting wide binary systems could be due to planet signatures, where the role of the planetary mass is still unknown. We search for a possible planet signature by analyzing the TC trends in the remarkable binary system HD 196067–HD 196068. At the moment, only HD 196067 is known to host a planet which is near the brown dwarf regime. We take advantage of the strong physical similarity between both stars, which is crucial to achieving the highest possible precision in stellar parameters and elemental chemical abundances. This system gives us a unique opportunity to explore if a possible depletion of refractories in a binary system could be inhibited by the presence of a massive planet. We performed a line-by-line chemical differential study, employing the non-solar-scaled opacities, in order to reach the highest precision in the calculations. After differentially comparing both stars, HD 196067 displays a clear deficiency in refractory elements in the TC plane, a lower iron content (0.051 dex) and also a lower Li i content (0.14 dex) than its companion. In addition, the differential abundances reveal a TC trend. These targets represent the first cases of an abundance difference around a binary system hosting a super-Jupiter. Although we explored several scenarios to explain the chemical anomalies, none of them can be entirely ruled out. Additional monitoring of the system as well as studies of larger sample of wide binary systems hosting massive planets, are needed to better understand the chemical abundance trend observed in HD 196067-68.Fil: Flores, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Galarza, J. Yana. Carnegie Observatories; Estados UnidosFil: Miquelarena Hollger, Paula Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Saffe, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Arancibia, M. Jaque. Universidad de La Serena; ChileFil: Ibañez Bustos, Romina Valeria. Observatoire de la Cote D'Azur; Francia. Centre National de la Recherche Scientifique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jofre, Jorge Emiliano. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Alacoria, José Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Gunella Toledo, Jose Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentin

    Tris(diphenylthiophosphinoyl)methanide as tripod ligand in rhodium(III), iridium(III) and ruthenium(II) complexes. Crystal structures of [(η5-C5Me5)Ir{η3-(SPPh2)3C-S,S′,S″}]BF4 and [(η6-MeC6H4Pri)Ru{η3-(SPPh2)3C-S,S′,S″}]BPh4

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    Reaction of the complex [{(η5-C5Me5)RhCl2}2], in CH2Cl2 solution, with AgBF4 (1:2 molar ratio) and (SPPh2)3CH leads to the cationic compound [(η5-C5Me5)RhCl{η2-(SPPh2)2CH(SPPh2)-S,S′}]BF4 (1) which is deprotonated by thallium(I) pyrazolate affording [(η5-C5Me5)Rh{η3-(SPPh2)3C−S,S′,S″}]BF4 (2a). The iridium dimer [(η5-C5Me5)IrCl2}2] reacts with silver salts and (SPPh2)3CH, in CH2Cl2 or Me2CO, under analogous conditions, affording mixtures of [(η5-C5Me5)IrCl{η2-(SPPh2)2)-S,S′}]+ and [(η5-C5Me5)Ir{η3-(SPPh2)3C-S,S′,S″}]A [A=BF4− (3a), PF6− (3b). Addition of Et3N to the mixture gives pure complexes 3. The ruthenium complexes [{η6j6-arene)RuCl2}2] (arene = C6Me6, p-MeC6H4Pri) react with (SPPh2)3CH, in the presence of AgA (A = PF6− or BF4−) or Na BPh4, in CH2Cl2 or Me2CO, yielding only the deprotonated complexes [(η6-arene)Ru{η3-(SPPH2)3C−S,S′,S″}]A [arene = C6Me6, A = BF4; arene = p-MeC6H4Pri, A - BPh4 (4a), PF6 (4b)]. The crystal structures of 3a and 4a were established by X-ray crystallography. Compound 3a crystallizes in the orthorhombic space group Pna21, with lattice parameters a-41.477(6), b = 10.6778(11), c = 20.162(3) Å and Z=8. Complex 4a crystallizes in a monoclinic lattice, space group P21/n, with a = 20.810(4), b = 12.555(3), c = 23.008(4) Å, β = 95.82(2)° and Z = 4. Both cationic complexes exhibit analogous pseudo-octahedml molecular structures with the anionic (SPPh2)3C− ligand bonded via the three sulphur atoms in a tripodal, tridentate fashion. Each metal centre completes its coordination environment with a η5-C5Me5 (3a) or a η6-MeC6H4Pri group (4a). A quite interesting result concerns the non-planarity of the methanide carbon which display P−C−P angles in the range 112.6–114.4(5)° in 3a and 111.9–113.6(4)° in 4a. The redox chemistry of the complexes was investigated by cyclic voltammetry. The Rh(III) complexes are quasi-reversibly reduced to Rh(I) and the Ir(III) complex is irreversibly reduced to IKD in acetonitrile solutions. The Ru(II) complex undergoes a quasi-reversible reduction to Ru(I) and a reversible oxidation to Ru(III).We thank the 'Fondo de Desarrollo Cientifico y Tecnologico, Chile' (Grant No. 460/93-95), Direccion de Investigacion y Postgrado, Pontificia Universidad Catolica de Chile (DlPUC), Fundacion Andes, Chile, and the Instituto de Cooperacion Iberoamericano, Spain, for financial support.Peer reviewe

    TLR4, but Neither Dectin-1 nor Dectin-2, Participates in the Mollusk Hemocyanin-Induced Proinflammatory Effects in Antigen-Presenting Cells From Mammals

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    Funding This study was supported by CONICYT-CHILE FONDECYT Regular Grant 1151337 to MB. FONDAP 15130011 to SL. CONICYT-CHILE National Ph.D. Fellowships were awarded to JJ (CONICYT-PCHA/Doctorado Nacional/2013-21130683) and to JO-Q (CONICYT-PFCHA/Doctorado Nacional/2017-21171588). FS holds a postdoctoral fellowship from the National Commission for Scientific and Technological Research (CONICYT), Chile. Funding was provided by the Wellcome Trust (102705, 097377), the MRC Centre for Medical Mycology and the University of Aberdeen (MR/N006364/1) to GB. Acknowledgments We thank Dr. María Rosa Bono, Dr. Sergio Vargas, and Dr. Juan Carlos Aguillón from Universidad de Chile and Dr. Mónica Imarai from Universidad de Santiago, Chile for helpful comments.Peer reviewedPublisher PD

    Preneoplastic somatic mutations including MYD88(L265P) in lymphoplasmacytic lymphoma

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    Normal cell counterparts of solid and myeloid tumors accumulate mutations years before disease onset; whether this occurs in B lymphocytes before lymphoma remains uncertain. We sequenced multiple stages of the B lineage in elderly individuals and patients with lymphoplasmacytic lymphoma, a singular disease for studying lymphomagenesis because of the high prevalence of mutated MYD88. We observed similar accumulation of random mutations in B lineages from both cohorts and unexpectedly found MYD88(L265P) in normal precursor and mature B lymphocytes from patients with lymphoma. We uncovered genetic and transcriptional pathways driving malignant transformation and leveraged these to model lymphoplasmacytic lymphoma in mice, based on mutated MYD88 in B cell precursors and BCL2 overexpression. Thus, MYD88(L265P) is a preneoplastic event, which challenges the current understanding of lymphomagenesis and may have implications for early detection of B cell lymphomas

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Envelope analysis of the airflow signal to improve polysomnographic assessment of sleep disordered breathing

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    Study Objectives: Given the detailed respiratory waveform signal provided by the nasal cannula in polysomnographic (PSG) studies, to quantify sleep breathing disturbances by extracting a continuous variable based on the coefficient of variation of the envelope of that signal. Design: Application of an algorithm for envelope analysis to standard nasal cannula signal from actual polysomnographic studies. Setting: PSG recordings from a sleep disorders center were analyzed by an algorithm developed on the Igor scientific data analysis software. Patients or Participants: Recordings representative of different degrees of sleep disordered breathing (SDB) severity or illustrative of the covariation between breathing and particularly relevant factors and variables. Interventions: The method calculated the coefficient of variation of the envelope for each 30-second epoch. The normalized version of that coefficient was defined as the respiratory disturbance variable (RDV). The method outcome wa

    Hipovitaminosis D en pacientes hospitalizados por trastornos por consumo de sustancias en Unidad de Adicciones del Hospital Clínico Universidad de Chile

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    The pathological consumption of alcohol and other drugs is associated with calcium metabolism disfunction through different pathways. Hypovitaminosis D contributes to acute a chronic neuronal injury in alcohol dependent patients. We do not have national evidence regarding the presence of hypovitaminosis D in addicted patients and there is a lack of information in the literature regarding polysubstance users. In this retrospective study, we evaluate the presence of hypovitaminosis of D in Substance Use Disorder inpatients treated in the Psychiatric Clinic of the University during the months of August to November 2017 and we described their main characteristics. 24 patients were evaluated, 19 of whom presented levels lower than 30 ng/ml of Vitamin D. Of those patients with hypovitaminosis 79% were men and 90% of them consumed alcohol, although in only 26% alcohol was the main substance. The main substance reported by the patients was cocaine (37%), smokable cocaine (32%) and marijuana (5%). Despite the methodological limitations of the study and the high prevalence of Hypovitaminosis D reported in the Chilean population, the results of this study suggest the need for a systematic evaluation of Vitamin D levels in patients hospitalized for addictions to adequately supplement those who require it

    Structural Changes of Amyloid Beta in Hippocampus of Rats Exposed to Ozone: A Raman Spectroscopy Study

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    The aim of this work was to study the effect of oxidative stress on the structural changes of the secondary peptide structure of amyloid beta 1–42 (Aβ 1–42), in the dentate gyrus of hippocampus of rats exposed to low doses of ozone. The animals were exposed to ozone-free air (control group) and 0.25 ppm ozone during 7, 15, 30, 60, and 90 days, respectively. The samples were studied by: (1) Raman spectroscopy to detect the global conformational changes in peptides with α-helix and β-sheet secondary structure, following the deconvolution profile of the amide I band; and (2) immunohistochemistry against Aβ 1–42. The results of the deconvolutions of the amide I band indicate that, ozone exposure causes a progressively decrease in the abundance percentage of α-helix secondary structure. Furthermore, the β-sheet secondary structure increases its abundance percentage. After 60 days of ozone exposure, the β-sheet band is identified in a similar wavenumber of the Aβ 1–42 peptide standard. Immunohistochemistry assays show an increase of Aβ 1–42 immunoreactivity, coinciding with the conformational changes observed in the Raman spectroscopy of Aβ 1–42 at 60 and 90 days. In conclusion, oxidative stress produces changes in the folding process of amyloid beta peptide structure in the dentate gyrus, leading to its conformational change in a final β-sheet structure. This is associated to an increase in Aβ 1–42 expression, similar to the one that happens in the brain of Alzheimer’s Disease (AD) patients

    PROCEDIMIENTO DE ESCISIÓN ELECTRO-QUIRÚRGICA POR ASA TÉRMICA Y RIESGO DE PARTO PREMATURO: UNA REVISIÓN SISTEMÁTICA DE LA LITERATURA

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    Antecedentes: A diferencia de la conización cervical por cono frío, no se ha podido demostrar una clara asociación entre el procedimiento de escisión electro-quirúrgica por asa térmica (LEEP) y el riesgo de parto prematuro. Objetivo: Análisis crítico de la literatura científica, en relación al riesgo de presentar un parto prematuro en pacientes que han sido sometidas a LEEP, y los resultados materno-perinatales asociados. Búsqueda sistemática en múltiples bases de datos. Resultados: Se encontraron sólo tres artículos que cumplían los criterios de inclusión, los cuales son incluidos en esta revisión. De éstos, el primero muestra que el LEEP no aumenta el riesgo de parto prematuro ni de recién nacidos de bajo peso. El segundo evidencia un aumento del riesgo de rotura prematura de membranas y parto prematuro secundario a esto, pero no de parto prematuro espontáneo. Sin embargo, el tercero, señala que el LEEP se asocia en forma significativa a riesgo aumentado de parto prematuro, parto prematuro secundario a rotura prematura de membranas y recién nacidos de bajo peso. Los tres estudios son de cohortes retrospectivas, lo cual les otorga un nivel de evidencia de tipo 2b. Conclusión: La evidencia indica que la excision de la zona de transformación a través del uso de LEEP está asociada a un pequeño, pero real incremento del riesgo de presentar un parto de prétermino.<br>Background: Unlike cold-knife conization, studies have shown conflicting results on the outcome of pregnancy following loop electrosurgical excision procedure (LEEP). Objective: Critical analysis of the literature to establish if the LEEP treatments increase risk of preterm delivery and its influence in maternal-perinatal results. Results: Only three studies were filling the inclusion criteria. The first study does not show that LEEP treatment increase risk of preterm delivery and low birth weight. The second study shows increased risk of premature rupture of membranes and the subsequent preterm delivery, but not spontaneous preterm delivery. Nevertheless, the third study shows increased risk of premature rupture of membranes and the subsequent preterm delivery, spontaneous preterm delivery and low birth weight. The three studies are based in retrospective cohorts, which grant them a level of evidence of type 2b. Conclusion: The evidence indicates that loop excision of the transformation zone by LEEP is associated with a small but real increase the risk of preterm delivery

    Recursos naturales y proyectos de diseño urbano en Colina : proposiciones de estudiantes (Escuela Agrícola, Acueducto Energitérmico, Borde de Recreación Inundable, Cementerio)

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    An intervention in a commune urban-rural in character and anagro-industrial vocation, with a deterioration of its urban environment.Se interviene en una comuna de caracter urbano-rural y vocación agro-industrial que presenta un fuerte deterioro en su medio ambiente urbano
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