Optimización del Tratamiento Térmico de Productos Tubulares de Acero

[Optimization of Heat Treatment of Steel Tubular Products] El problema a abordar es el de la optimización del tratamiento térmico de productos tubulares de acero, presente en la empresa siderúrgica Tenaris. Más específicamente, se estudia el problema de dar un tratamiento adecuado a cargas retenidas en el horno de revenido. En este caso, el tratamiento térmico se compone de un primer calentamiento de los tubos a temperaturas cercanas a los 900°C, en el que se austeniza el material, seguido por un enfriamiento rápido en el que el material se transforma en martensita. Esta etapa constituye el templado del acero. Para lograr las propiedades metalúrgicas finales especificadas para el producto se realiza un segundo calentamiento a temperaturas entre 500 y 700°C, que se denomina revenido. Para simplificar el análisis, en este trabajo se considera una única propiedad metalúrgica, la dureza, que para el producto que se analiza debe estar en el rango de 270-300 Hv

Communication protocols evaluation for a wireless rainfall monitoring network in an urban area

Rainfall monitoring networks are key elements for the development of alerts and prediction models for communities at risk of flooding during high intensity rainfall events. Currently, most of these networks send the precipitation measurement to a data center in real-time using wireless communication protocols, avoiding travel to the measurement site. An Early Warning System (EWS) for pluvial flash floods developed in Barranquilla (Colombia), used the GPRS protocol to send rain gauge data in real-time to a web server for further processing; however, this protocol has a high consumption of energy and also high maintenance costs. This article carried out an evaluation in terms of link budget, link profile, energy consumption and devices costs of three low-power wireless communication protocols, Zigbee, LoRaWAN and Sigfox, to determine which one is the most suitable for the EWS of the city of Barranquilla. To perform the evaluation, a wireless sensor network was designed and characterized for Zigbee and LoRaWAN with Radio Mobile tool taking into account the measurement points implemented with GPRS network. The evaluation included the power consumption of Zigbee, LoRaWAN and Sigfox. From the results of simulations, LoRaWAN and Zigbee network has similar radio signal received and the LoRaWAN network obtains the least losses per path. As for power consumption, the LoRaWAN devices has the lowest energy consumption, as well as, the LoRaWAN network sensor nodes are cheaper. Finally, the protocol with the best general performance was LoRAWAN, since complies with the communication, consumption and cost requirements

Contribuciones al conocimiento de nematodos parásitos de anfibios de la ecorregión Chaco Seco de Argentina

Contribuciones al conocimiento de nematodos parásitos de anfibios de la ecorregión Chaco Seco de Argentina. En el Gran Chaco Argentino, numerosas investigaciones han tratado la diversidad de los vertebrados, incluida su fauna herpetológica. En cuanto a la parasitofauna de estos organismos, algunos grupos como el de los anfibios han sido más estudiados; sin embargo, biogeográficamente, la mayor parte de estos estudios fueron realizados en el Chaco Húmedo. El objetivo de este trabajo es presentar la nematofauna hallada en seis especies de anfibios, Rhinella diptycha, Chacophrys pierottii, Ceratophrys cranwelli, Scinax nasicus, Leptodactylus bufonius y Odontophrynus lavillai, colectadas en distintos puntos del Chaco Seco en el departamento de Matacos, Formosa, Argentina. En un total de 34 anfibios analizados encontramos 1.526 nematodes parásitos (prevalencia total: 61,7%; intensidad media total: 72,6±90,3; abundancia media total: 44,9±78,9), pertenecientes a 9 taxones, adultos de Rhabdias sp., Oswaldocruzia sp., O. subauricularis, Schulzia travassosi, Aplectana hylambatis, Cosmocerca podicipinus, Oxyascaris caudacutus, Schrankiana formosula y larvas de Physaloptera sp. Estos nematodos se colectaron de los pulmones, el intestino delgado, el intestino grueso, la mucosa gástrica y la vesícula biliar de los hospedadores. Este trabajo constituye el primer registro de helmintos para C. pierottii y O. lavillai y el primero de nematodes para Ce. cranwelli en toda su área de distribución geográfica. La especie Schrankiana formosula (Atractidae) es registrada por primera vez en anfibios argentinos. De este modo, ampliamos el conocimiento de la diversidad biológica de los helmintos parásitos de anfibios de la ecorregión Chaco Seco. Esta información permitirá conocer cuáles son los factores que influyen en los patrones de ocurrencia en hospedadores y distribución geográfica de helmintos parásitos de vertebrados, en un área con características tan extremas como el Chaco SecoIn the Argentinean Gran Chaco, numerous investigations have dealt with the diversity of vertebrates, including amphibians and reptiles. The parasitofauna of these organisms, has been more studied in some groups such as amphibians; however, from a biogeographic perspective, most of these studies were carried out in the Humid Chaco. The goal of this work is to present the nematofauna found in six species of amphibians, Rhinella diptycha, Chacophrys pierottii, Ceratophrys cranwelli, Scinax nasicus, Leptodactylus bufonius, and Odontophrynus lavillai, collected in different locations within the Dry Chaco, in the department of Matacos, Formosa, Argentina. In a total of 34 amphibians analyzed, we found 1,526 parasitic nematodes (total prevalence: 61.7%; total mean intensity: 72.6±90.3; total mean abundance: 44.9±78.9), belonging to 9 taxa: adults of Rhabdias sp., Oswaldocruzia sp., O. subauricularis, Schulzia travassosi, Aplectana hylambatis, Cosmocerca podicipinus, Oxyascaris caudacutus, Schrankiana formosula, and larvae of Physaloptera sp. These nematodes were collected from the lungs, small intestine, large intestine, gastric mucosa, and gallbladder of hosts. This work is the first record of helminths from C. pierottii and O. lavillai and the first record of nematodes from Ce. cranwelli throughout its geographical range. The species Schrankiana formosula (Atractidae) is recorded for the first time in Argentinean amphibians. Thus, we expand the knowledge of the biological diversity of helminth parasites of amphibians from the Dry Chaco ecoregion. This base-line information, would allow to understand the factors that influence the patterns of host and geographic distribution of vertebrate parasites in an area with extreme characteristics such as the Dry Chaco.Fil: Gonzalez, Cynthya Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Duré Pitteri, Marta Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Palomas Alaniz, Yanina Soledad. Universidad Nacional de Jujuy. Instituto de Ecorregiones Andinas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Ecorregiones Andinas; ArgentinaFil: Schaefer, Eduardo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Investigaciones Geohistóricas. Universidad Nacional del Nordeste. Instituto de Investigaciones Geohistóricas; ArgentinaFil: Etchepare, Eduardo Gabriel. Universidad Tecnológica Nacional. Facultad Regional de Concordia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Acosta, José Luis. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Departamento de Biología. Laboratorio de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Comparative Analysis of Clinical Practice Guidelines for the Pharmacological Treatment of Type 2 Diabetes Mellitus in Latin America

Purpose of review: Type 2 diabetes mellitus (T2DM) is one of the leading causes of death and disability in the world. The majority of diabetes deaths (> 80%) occur in low- and middle-income countries, which are predominant in Latin America. Therefore, the purpose of this article is to compare the clinical practice guideline (CPG) for the pharmacological management of T2DM in Latin America (LA) with international reference guidelines. Recent findings: Several LA countries have recently developed CPGs. However, the quality of these guidelines is unknown according to the AGREE II tool and taking as reference three CPGs of international impact: American Diabetes Association (ADA), European Diabetes Association (EASD), and Latin American Diabetes Association (ALAD). Ten CPGs were selected for analysis. The ADA scored > 80% on the AGREE II domains and was selected as the main comparator. Eighty percent of LA CPGs were developed before 2018. Only one was not recommended (all domains < 60%). The CPGs in LA have good quality but are outdated. They have significant gaps compared to the reference. There is a need for improvement, as proposing updates every three years to maintain the best available clinical evidence in all guidelines.This research was funded by SANOFI and was developed by Sapyens SAS BIC.S

High Prevalence of Systemic Autoimmune Diseases in Patients with Menière's Disease

BACKGROUND: Autoimmunity appears to be associated with the pathophysiology of Meniere's disease (MD), an inner ear disorder characterized by episodes of vertigo associated with hearing loss and tinnitus. However, the prevalence of autoimmune diseases (AD) in patients with MD has not been studied in individuals with uni or bilateral sensorineural hearing loss (SNHL). METHODS AND FINDINGS: We estimated the prevalence of AD in 690 outpatients with MD with uni or bilateral SNHL from otoneurology clinics at six tertiary referral hospitals by using clinica criteria and an immune panel (lymphocyte populations, antinuclear antibodies, C3, C4 and proinflammatory cytokines TNFα, INFγ). The observed prevalence of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and ankylosing spondylitis (AS) was higher than expected for the general population (1.39 for RA, 0.87 for SLE and 0.70 for AS, respectively). Systemic AD were more frequently observed in patients with MD and diagnostic criteria for migraine than cases with MD and tension-type headache (p = 0.007). There were clinical differences between patients with uni or bilateral SNHL, but no differences were found in the immune profile. Multiple linear regression showed that changes in lymphocytes subpopulations were associated with hearing loss and persistence of vertigo, suggesting a role for the immune response in MD. CONCLUSIONS: Despite some limitations, MD displays an elevated prevalence of systemic AD such as RA, SLE and AS. This finding, which suggests an autoimmune background in a subset of patients with MD, has important implications for the treatment of MD

The soft X-ray and narrow-line emission of Mrk573 on kiloparcec scales

We present a study of the circumnuclear region of the nearby Seyfert galaxy Mrk573 using Chandra, XMM-Newton and HST data. The X-ray morphology shows a biconical region extending up to 12 arcsecs (4 kpc) in projection from the nucleus. A strong correlation between the X-rays and the highly ionized gas seen in the [O III] image is reported. Moreover, we have studied the line intensities detected with the RGS/XMM-Newton and used them to fit the low resolution EPIC/XMM-Newton and ACIS/Chandra spectra. The RGS spectrum is dominated by emission lines of C VI, O VII, O VIII, Fe XVII, and Ne IX, among others. A good fit is obtained using these emission lines found in the RGS spectrum as a template for Chandra spectra of the nucleus and extended emission. The photoionization model Cloudy provides a reasonable fit for both the nuclear region and the cone-like structures. For the nucleus the emission is modelled using two phases: a high ionization [log(U)=1.23] and a low ionization [log(U)=0.13]. For the high ionization phase the transmitted and reflected component are in a ratio 1:2, whereas for the low ionization the reflected component dominates. For the extended emission, we successfully reproduced the emission with two phases. The first phase shows a higher ionization parameter for the NW (log(U)=0.9) than for the SE cone (log(U)=0.3). The second phase shows a low ionization parameter (log(U)=-3) and is rather uniform for NW and SE cones. In addition, the nuclear optical/infrared SED has been modeled by a clumpy torus model. The torus bolometric luminosity agrees with the AGN luminosity inferred from the observed hard X-ray spectrum. The optical depth along the line of sight derived from the SED fit indicates a high neutral column density in agreement with the classification of the nucleus as a Compton-thick AGN.Comment: 15 pages, 14 figures, final version of the paper submitted to Ap

Human adipose-derived mesenchymal stem cell-conditioned medium ameliorates polyneuropathy and foot ulceration in diabetic BKS db/db mice

Background: Diabetic polyneuropathy (DPN) is the most common and early developing complication of diabetes mellitus, and the key contributor for foot ulcers development, with no specific therapies available. Different studies have shown that mesenchymal stem cell (MSC) administration is able to ameliorate DPN; however, limited cell survival and safety reasons hinder its transfer from bench to bedside. MSCs secrete a broad range of antioxidant, neuroprotective, angiogenic, and immunomodulatory factors (known as conditioned medium), which are all decreased in the peripheral nerves of diabetic patients. Furthermore, the abundance of these factors can be boosted in vitro by incubating MSCs with a preconditioning stimulus, enhancing their therapeutic efficacy. We hypothesize that systemic administration of conditioned medium derived from preconditioned MSCs could reverse DPN and prevent foot ulcer formation in a mouse model of type II diabetes mellitus. Methods: Diabetic BKS db/db mice were treated with systemic administration of conditioned medium derived from preconditioned human MSCs; conditioned medium derived from non-preconditioned MSCs or vehicle after behavioral signs of DPN was already present. Conditioned medium or vehicle administration was repeated every 2 weeks for a total of four administrations, and several functional and structural parameters characteristic of DPN were evaluated. Finally, a wound was made in the dorsal surface of both feet, and the kinetics of wound closure, re-epithelialization, angiogenesis, and cell proliferation were evaluated. Results: Our molecular, electrophysiological, and histological analysis demonstrated that the administration of conditioned medium derived from non-preconditioned MSCs or from preconditioned MSCs to diabetic BKS db/db mice strongly reverts the established DPN, improving thermal and mechanical sensitivity, restoring intraepidermal nerve fiber density, reducing neuron and Schwann cell apoptosis, improving angiogenesis, and reducing chronic inflammation of peripheral nerves. Furthermore, DPN reversion induced by conditioned medium administration enhances the wound healing process by accelerating wound closure, improving the re-epithelialization of the injured skin and increasing blood vessels in the wound bed in a skin injury model that mimics a foot ulcer. Conclusions: Studies conducted indicate that MSC-conditioned medium administration could be a novel cell-free therapeutic approach to reverse the initial stages of DPN, avoiding the risk of lower limb amputation triggered by foot ulcer formation and accelerating the wound healing process in case it occurs.Fil: De Gregorio, Cristian. Universidad del Desarrollo; ChileFil: Contador, David. Universidad del Desarrollo; ChileFil: Díaz, Diego. Universidad del Desarrollo; ChileFil: Cárcamo, Constanza. Universidad del Desarrollo; ChileFil: Santapau, Daniela. Universidad del Desarrollo; ChileFil: Lobos Gonzalez, Lorena. Universidad del Desarrollo; ChileFil: Acosta, Cristian Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Campero, Mario. Universidad de Chile; ChileFil: Carpio, Daniel. Universidad Austral de Chile; ChileFil: Gabriele, Caterina. University Of Catanzaro; ItaliaFil: Gaspari, Marco. University Of Catanzaro; ItaliaFil: Aliaga Tobar, Victor. Universidad de Chile; ChileFil: Maracaja Coutinho, Vinicius. Universidad de Chile; ChileFil: Ezquer, Marcelo. Universidad del Desarrollo; ChileFil: Ezquer, Fernando. Universidad del Desarrollo; Chil

Senolytic treatment preserves biliary regenerative capacity lost through cellular senescence during cold storage

Liver transplantation is the only curative option for patients with end-stage liver disease. Despite improvements in surgical techniques, nonanastomotic strictures (characterized by the progressive loss of biliary tract architecture) continue to occur after liver transplantation, negatively affecting liver function and frequently leading to graft loss and retransplantation. To study the biological effects of organ preservation before liver transplantation, we generated murine models that recapitulate liver procurement and static cold storage. In these models, we explored the response of cholangiocytes and hepatocytes to cold storage, focusing on responses that affect liver regeneration, including DNA damage, apoptosis, and cellular senescence. We show that biliary senescence was induced during organ retrieval and exacerbated during static cold storage, resulting in impaired biliary regeneration. We identified decoy receptor 2 (DCR2)–dependent responses in cholangiocytes and hepatocytes, which differentially affected the outcome of those populations during cold storage. Moreover, CRISPR-mediated DCR2 knockdown in vitro increased cholangiocyte proliferation and decreased cellular senescence but had the opposite effect in hepatocytes. Using the p21KO model to inhibit senescence onset, we showed that biliary tract architecture was better preserved during cold storage. Similar results were achieved by administering senolytic ABT737 to mice before procurement. Last, we perfused senolytics into discarded human donor livers and showed that biliary architecture and regenerative capacities were better preserved. Our results indicate that cholangiocytes are susceptible to senescence and identify the use of senolytics and the combination of senotherapies and machine-perfusion preservation to prevent this phenotype and reduce the incidence of biliary injury after transplantation.This work was supported by the UK Medical Research MRC (MR/K017047/1) (to S.J.F.), the Computational and Chemical Biology of Stem Cell Niche (MR/L012766/1) (to S.J.F.), the UK Regenerative Medicine Platform (MR/K026666/1) (to S.J.F.), and the Wellcome Trust Institutional Translational Partnership Award (WT iTPA) (to S.F.-G.). J.M.B. was supported by the Spanish Carlos III Health Institute (ISCIII) (PI15/01132, PI18/01075, and Miguel Servet Program CON14/00129 and CPII19/00008) cofinanced by “Fondo Europeo de Desarrollo Regional” (FEDER); “Instituto de Salud Carlos III” (CIBERehd), Spain; “Euskadi RIS3” (2019222054 and 2020333010); and the Department of Industry of the Basque Country (Elkartek: KK-2020/00008). This research was funded in whole or in part by The Wellcome Trust (grant number 209710/Z/17/Z), a cOAlition S organization

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie