156 research outputs found
Temperature Dependence of Electrical Resistance in Ge-Sb-Te Thin Films
Nowadays, the Ge-Sb-Te system is studied extensively for use in the field of both electrical and optical non-volatile memories. The key of this application is based on the changes in the physical properties (electrical conductivity or refractive index) of these films as a result of structural transformation between amorphous and crystalline states. Both states are highly stable and it is relatively easy to change between them when they are prepared as thin films. In this work, structural and electrical behaviours with the temperature of thin films with compositions Ge13Sb5Te82, Ge1Sb2Te4, Ge2Sb2Te5, Ge1Sb4Te7 and Sb70Te30 (atomic fraction) were studied. Films were obtained by pulsed laser deposition (PLD) using a pulsed Nd:YAG laser (λ = 355 nm) and they were structurally characterized by X-ray diffraction. Temperature dependence of electrical resistance was studied for these films from room temperature to 520 K at a heating rate about 3 K/min. During crystallization, their electrical resistance falls several orders of magnitude in a narrow temperature range. The electrical conduction activation energies of the amorphous and crystalline states and the crystallization temperature were determined. The crystallization products were characterized by X-ray diffraction. The results were compared with those obtained by other authors.Fil: Rocca, Javier Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Laboratorio de Sólidos Amorfos; ArgentinaFil: García, Jose Luis Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Laboratorio de Sólidos Amorfos; ArgentinaFil: Ureña, María Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Laboratorio de Sólidos Amorfos; ArgentinaFil: Fontana, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Laboratorio de Sólidos Amorfos; ArgentinaFil: Arcondo, Bibiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Laboratorio de Sólidos Amorfos; Argentin
A galectin-specific signature in the gut delineates Crohn’s disease and ulcerative colitis from other human inflammatory intestinal disorders
Inflammatory bowel diseases (IBD) are chronic and relapsing inflammatory conditions of the gastrointestinal tract including Crohn’s disease (CD) and ulcerative colitis (UC). Galectins, defined by shared consensus amino acid sequence and affinity for b-galactosides, are critical modulators of the inflammatory response. However, the relevance of the galectin network in the pathogenesis of human IBD has not yet been explored. Here, we analyzed the expression of relevant members of the galectin family in intestinal biopsies, and identified their contribution as novel mucosal markers in IBD. Colonic biopsies were obtained from 59 IBD patients (22 CD and 37 UC), 9 patients with gut rejection after transplantation, 8 adult celiac patients, and 32 non-IBD donors.
Galectin mRNA expression was analyzed by RT-PCR and qPCR using specific primers for individual galectins. A linear discriminant analysis (LDA) was used to analyze galectin expression in individual intestinal samples. Expression of common mucosalassociated galectins (Gal-1, 23, 24, 29) is dysregulated in inflamed tissues of IBD patients compared with noninflamed IBD or control samples. LDA discriminated between different inflammation grades in active IBD and showed that remission IBD samples were clusterized with control samples. Galectin profiling could not distinguish CD and UC. Furthermore, inflamed IBD was discriminated from inflamed tissue of rejected gut in transplanted patients and duodenum of celiac patients, which could not be distinguished from control duodenum samples. The integrative analysis of galectins discriminated IBD from other intestinal inflammatory conditions and could be used as potential mucosal biomarker.Instituto de Estudios Inmunológicos y Fisiopatológico
Probiotic Lactobacilli Isolated from Kefir Promote Down-Regulation of Inflammatory Lamina Propria T Cells from Patients with Active IBD
Ulcerative colitis and Crohn’s disease, the two main forms of inflammatory bowel disease (IBD), are immunologically mediated disorders. Several therapies are focused on activated T cells as key targets. Although Lactobacillus kefiri has shown anti-inflammatory effects in animal models, few studies were done using human mucosal T cells. The aim of this work was to investigate the immunomodulatory effects of this bacterium on intestinal T cells from patients with active IBD. Mucosal biopsies and surgical samples from IBD adult patients (n = 19) or healthy donors (HC; n = 5) were used. Lamina propria mononuclear cells were isolated by enzymatic tissue digestion, and entero-adhesive Escherichia coli-specific lamina propria T cells (LPTC) were expanded. The immunomodulatory properties of L. kefiri CIDCA 8348 strain were evaluated on biopsies and on anti-CD3/CD28-activated LPTC. Secreted cytokines were quantified by ELISA, and cell proliferation and viability were assessed by flow cytometry. We found that L. kefiri reduced spontaneous release of IL-6 and IL-8 from inflamed biopsies ex vivo. Activated LPTC from IBD patients showed low proliferative rates and reduced secretion of TNF-α, IL-6, IFN-γ and IL-13 in the presence of L. kefiri. In addition, L. kefiri induced an increased frequency of CD4+FOXP3+ LPTC along with high levels of IL-10. This is the first report showing an immunomodulatory effect of L. kefiri CIDCA 8348 on human intestinal cells from IBD patients. Understanding the mechanisms of interaction between probiotics and immune mucosal cells may open new avenues for treatment and prevention of IBD.Fil: Curciarello, Renata. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Canziani, Karina Eva. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Salto, Ileana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Barbiera Romero, Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Rocca, Andrés. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Doldan, Ivan. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Peton, Emmanuel. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Brayer, Santiago. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Sambuelli, Alicia. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Goncalves, Silvina. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Tirado, Pablo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Correa, Gustavo Javier. Hospital Interzonal General de Agudos San Martín; ArgentinaFil: Yantorno, Martín. Hospital Interzonal General de Agudos San Martín; ArgentinaFil: Garbi, Laura. Hospital Interzonal General de Agudos San Martín; ArgentinaFil: Docena, Guillermo H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Serradell, María de los Ángeles. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Cátedra de Microbiología General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Muglia, Cecilia Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentin
Revisión de laudos arbitrales de inversión 2020: 2º Encuentro Anual (Santiago de Chile, 07-08/06/2021)
Durante los días 7 y 8 de junio de 2021 fue celebrada la segunda edición del evento sobre revisión de laudos, en el marco de arbitrajes inversor-Estado, dictados durante el año 2020. En esta oportunidad, la actividad estuvo coorganizada por la Universidad Autónoma de Chile y la Universidad Finis Terrae, con la especial colaboración institucional del Centro de Arbitraje y Mediación de la Cámara de Comercio de Santiago, la Subsecretaría de Relaciones Económicas Internacionales del Ministerio de Relaciones Exteriores de Chile, la Universidad del Desarrollo, la Universidad del Rosario (Colombia), Florida International University (Estados Unidos), Universidade Federal do Rio Grande do Sul (Brasil), Heidelberg Center para América Latina, Apparcel, Uriarte & Vassallo y Lexincorp Central American Law Firm. Este evento también forma parte de los trabajos del Proyecto Fondecyt Iniciación sobre protección de la inversión chilena en el exterior frente al riesgo de expropiaciones indirectas, del cual Ivette Esis Villarroel es la Investigadora Responsable.
Durante 2020, a pesar de la pandemia y las consecuencias que ha traído, las estadísticas recientes publicadas por el Centro Internacional de Arreglo de Diferencias relativas a Inversiones del Banco Mundial (CIADI), el Instituto de Arbitraje de la Cámara de Comercio de Estocolmo y la Corte Permanente de Arbitraje, revelan un importante número de casos nuevos registrados en dichas instituciones. De ellas destaca el CIADI, institución arbitral que recibió 58 casos (siendo el mayor número de asuntos registrados en un año), mientras que SCC registró 4 casos nuevos y la CPA 126. Por ello, el evento en esta oportunidad contó con cuatro mesas conformadas por destacados ponentes y moderadores, donde fueron analizados laudos de jurisdicción, laudos de méritos y decisiones del Comité de Anulaciones del CIADI, además de discutir sobre el futuro de los mecanismos de solución de conflictos inversor – Estado.
Más allá de la excepcionalidad en todos los sentidos del año 2020, la jurisprudencia arbitral mantuvo una línea continuista. Las consecuencias de la pandemia para los inversores están avanzando a través del sistema sin todavía llegar a la fase de laudo. Discusiones clásicas como el concepto de consentimiento, la nacionalidad del inversionista o los límites del trato justo y equitativo siguen siendo el centro de la actividad arbitral en 2020. Igualmente, algunos de estos temas ya están presentes la jurisprudencia arbitral de 2021 y son brevemente comentados en esta crónica. Finalmente, los casos sobre energías renovables siguen presentando nuevas tensiones sobre las interacciones entre el derecho internacional de las inversiones y el derecho de las organizaciones regionales de integración económica. A este respecto señalar que en el 2020 se evidenció también dicha tensiones en el marco del derecho de la integración de América Latina
Autoantibodies against the immunodominant sCha epitope discriminate the risk of sudden death in chronic Chagas cardiomyopathy
In Chagas disease (ChD) caused by Trypanosoma cruzi, new biomarkers to predict chronic cardiac pathology are urgently needed. Previous studies in chagasic patients with mild symptomatology showed that antibodies against the immunodominant R3 epitope of sCha, a fragment of the human basic helix-loop-helix transcription factor like 5, correlated with cardiac pathology. To validate sCha as a biomarker and to understand the origin of anti-sCha antibodies, we conducted a multicenter study with several cohorts of chagasic patients with severe cardiac symptomatology. We found that levels of antibodies against sCha discriminated the high risk of sudden death, indicating they could be useful for ChD prognosis. We investigated the origin of the antibodies and performed an alanine scan of the R3 epitope. We identified a minimal epitope MRQLD, and a BLAST search retrieved several T. cruzi antigens. Five of the hits had known or putative functions, of which phosphonopyruvate decarboxylase showed the highest cross-reactivity with sCha, confirming the role of molecular mimicry in the development of anti-sCha antibodies. Altogether, we demonstrate that the development of antibodies against sCha, which originated by molecular mimicry with T. cruzi antigens, could discriminate electrocardiographic alterations associated with a high risk of sudden death.Ministerio de Economía y competitividad and Fondo Europeo de Desarrollo Regional (SAF2015-63868-R (MINECO/FEDER) to N.G., and SAF2016-75988-R (MINECO/FEDER) to M.F.); Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación and Fondo Europeo de Desarrollo Regional (PGC2018-096132-BI00 (MICINN/FEDER) to N.G.); Universidad Autónoma de Madrid-Banco de Santander Inter-University Cooperation Grant with Latin América (CEAL-AL/2015-12 to N.G.); Red de Investigación de Centros de Enfermedades Tropicales (RICET RD12/0018/0004 to M.F.); and Comunidad de Madrid (S-2010/BMD-2332 to M.F.). CBMSO institutional grants from Fundación Ramón Areces
and Banco de Santande
Expansion of the Human Phenotype Ontology (HPO) knowledge base and resources.
The Human Phenotype Ontology (HPO)-a standardized vocabulary of phenotypic abnormalities associated with 7000+ diseases-is used by thousands of researchers, clinicians, informaticians and electronic health record systems around the world. Its detailed descriptions of clinical abnormalities and computable disease definitions have made HPO the de facto standard for deep phenotyping in the field of rare disease. The HPO\u27s interoperability with other ontologies has enabled it to be used to improve diagnostic accuracy by incorporating model organism data. It also plays a key role in the popular Exomiser tool, which identifies potential disease-causing variants from whole-exome or whole-genome sequencing data. Since the HPO was first introduced in 2008, its users have become both more numerous and more diverse. To meet these emerging needs, the project has added new content, language translations, mappings and computational tooling, as well as integrations with external community data. The HPO continues to collaborate with clinical adopters to improve specific areas of the ontology and extend standardized disease descriptions. The newly redesigned HPO website (www.human-phenotype-ontology.org) simplifies browsing terms and exploring clinical features, diseases, and human genes
Sex differences in circulating proteins in heart failure with preserved ejection fraction
Background
Many patients with heart failure with preserved ejection fraction (HFpEF) are women. Exploring mechanisms underlying the sex differences may improve our understanding of the pathophysiology of HFpEF. Studies focusing on sex differences in circulating proteins in HFpEF patients are scarce.
Methods
A total of 415 proteins were analyzed in 392 HFpEF patients included in The Metabolic Road to Diastolic Heart Failure: Diastolic Heart Failure study (MEDIA-DHF). Sex differences in these proteins were assessed using adjusted logistic regression analyses. The associations between candidate proteins and cardiovascular (CV) death or CV hospitalization (with sex interaction) were assessed using Cox regression models.
Results
We found 9 proteins to be differentially expressed between female and male patients. Women expressed more LPL and PLIN1, which are markers of lipid metabolism; more LHB, IGFBP3, and IL1RL2 as markers of transcriptional regulation; and more Ep-CAM as marker of hemostasis. Women expressed less MMP-3, which is a marker associated with extracellular matrix organization; less NRP1, which is associated with developmental processes; and less ACE2, which is related to metabolism. Sex was not associated with the study outcomes (adj. HR 1.48, 95% CI 0.83–2.63), p = 0.18.
Conclusion
In chronic HFpEF, assessing sex differences in a wide range of circulating proteins led to the identification of 9 proteins that were differentially expressed between female and male patients. These findings may help further investigations into potential pathophysiological processes contributing to HFpEF
Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study
Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak.
Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study.
Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM.
Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide
Endovascular therapy of central nervous system. Feasibility of its practice in our Setting
Se estudiaron 28 pacientes portadores de lesiones neurovasculares complejas, tales como fístulas arteriovenosas, malformaciones arteriovenosas, aneurismas gigantes y tumores hipervasculares, los cuales fueron tratados mediante técnicas endovasculares.
Se evaluaron los hallazgos clínico radiológicos, así como la estrategia, materiales embólicos, resultados y complicaciones de la embolización, demostrándose la factibilidad de:
1. Acceder por vía endovascular mediante microcatéteres al interior de lesiones neurovasculares complejas.
2. Realizar una evaluación angiográfica superselectiva de las mismas.
3. Colocar por vía endovascular y en el seno de estas lesiones, agentes terapéuticos trombogénicos con resultados curativos, coadyuvantes a la cirugía o paliativos con un mínimo de morbilidad.We have studied 28 patients with neurovascular lesions including arteriovenous fistulae, arteriovenous malformations, giant intracranial aneurysms, and hypervascularized tumors that were treated with endovascular techniques.
Clinical and radiologic findings as well as strategies, embolization materials, therapy results and complications were jointly evaluated demonstrating the feasibility of:
1. Accessing neurovascular lesions by endovascular procedures through microcatheters.
2. Performing ultra-selective angiographic assessment of neurovascular lesions.
3. Positioning thrombogenic therapeutic agents in desired lesion sites by endovascular procedures with curative outcomes, as surgical adjuvants or paliatives for less morbidity
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