105 research outputs found

    Monte Carlo Calculations of Polarized Microwave Radiation Emerging from Cloud Structures

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    The last decade has seen tremendous growth in cloud dynamical and microphysical models that are able to simulate storms and storm systems with very high spatial resolution, typically of the order of a few kilometers. The fairly realistic distributions of cloud and hydrometeor properties that these models generate has in turn led to a renewed interest in the three-dimensional microwave radiative transfer modeling needed to understand the effect of cloud and rainfall inhomogeneities upon microwave observations. Monte Carlo methods, and particularly backwards Monte Carlo methods have shown themselves to be very desirable due to the quick convergence of the solutions. Unfortunately, backwards Monte Carlo methods are not well suited to treat polarized radiation. This study reviews the existing Monte Carlo methods and presents a new polarized Monte Carlo radiative transfer code. The code is based on a forward scheme but uses aliasing techniques to keep the computational requirements equivalent to the backwards solution. Radiative transfer computations have been performed using a microphysical-dynamical cloud model and the results are presented together with the algorithm description

    Effect of maternal diets enriched in PUFAs administrated to diabetic rats during early postimplantation on structures involved in decidual histotrophic function and feto placental growth

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    Maternal diabetes induces alterations in decidualization, which may impact on decidual histotrophic function that include key roles of the uterine glands (UG) and the glycogenic area (GA). uNK cells, in- volved in angiogenesis and vessels remodeling, are needed for an adequate decidualization and feto-placental development. We pre- viously found that maternal diets enriched in polyunsaturated fatty acids (PUFAs) prevent increased resorption rates in diabetic preg- nancies. Aim: To evaluate the effect of diets enriched in sunflower and chia oil (rich in n-6 and n-3 PUFAs respectively) administrated during early postimplantation to diabetic rats on PAS staining of the GA and UG and on the number of uNK cells at day 9 of pregnancy and on decidual, fetal and placental growth at day 14 of pregnan- cy. Methods: Pregestational diabetes was induced in Wistar rats by streptozotocin (50 mg/kg). On days 7 to 9 of pregnancy diabetic rats received a standard diet or diets enriched in 6% of sunflower or chia oil. On day 9 of pregnancy GA, UG and uNK cells in the de- cidua were evaluated by PAS staining. On day 14 of pregnancy the fetal cephalic length was measured and the decidua and placenta were weighted. Results: At day 9 of pregnancy PAS staining of GA (p<0.001;74%) and UG (p<0.05;64%) and the number of uNK cells (p<0.001;62%) were reduced in diabetic rats, alterations prevented by the PUFAs enriched diets. At day 14 of pregnancy a decreased fetal cephalic length in diabetic rats (7.5%; p<0.05) was prevented by the sunflower oil supplementation. Both decidual (18.3%;p<0.05) and placental (12.4%;p<0.05) weights were decreased in the diabet- ic group. The diet enriched in sunflower oil prevented the reduced decidual weight while the diet enriched in chia oil prevented the re- duced placental weight. Conclusion: The early postimplantation is a key period for decidual and feto-placental development, affected by maternal diabetes, and in which dietary treatments can exert ben- eficial effects.Fil: Roberti, Sabrina Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Gatti, Cintia Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Leonardi, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Higa, Romina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Jawerbaum, Alicia Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaLXVI Reunión anual de la Sociedad Argentina de Investigación Clínica; LXIX Reunión Anual de la Sociedad Argentina de Inmunología; LIII Reunión Anual de la Asociación Argentina de Farmacología Experimental y XI Reunión Anual de la Asociación Argentina de NanomedicinasArgentinaSociedad Argentina de Investigacion ClinicaSociedad Argentina de InmunologíaAsociación Argentina de Farmacología Experimental;Asociación Argentina de Nanomedicinas

    Enriching Proteolysis Targeting Chimeras with a Second Modality: When Two Are Better Than One

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    Proteolysis targeting chimera (PROTAC)-mediated protein degradation has prompted a radical rethink and is at a crucial stage in driving a drug discovery transition. To fully harness the potential of this technology, a growing paradigm toward enriching PROTACs with other therapeutic modalities has been proposed. Could researchers successfully combine two modalities to yield multifunctional PROTACs with an expanded profile? In this Perspective, we try to answer this question. We discuss how this possibility encompasses different approaches, leading to multitarget PROTACs, light-controllable PROTACs, PROTAC conjugates, and macrocycle-and oligonucleotide-based PROTACs. This possibility promises to further enhance PROTAC efficacy and selectivity, minimize side effects, and hit undruggable targets. While PROTACs have reached the clinical investigation stage, additional steps must be taken toward the translational development of multifunctional PROTACs. A deeper and detailed understanding of the most critical challenges is required to fully exploit these opportunities and decisively enrich the PROTAC toolbox

    TTAS a new stilbene derivative that induces apoptosis in Leishmania infantum.

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    Leishmania parasites are able to undergo apoptosis (programmed cell death), similarly to mammalian cells. Recently it was demonstrated in vitro the anti-leishmanial effect of some natural and synthetic stilbenoids including resveratrol and piceatannol. In this study we evaluated the Leishmanicidal activity of a pool of stilbene derivatives which had previously shown high apoptotic efficacy against neoplastic cells. All the compounds tested were capable to decrease the parasite viability in a dose-dependent manner. Trans-stilbenes proved to be markedly more effective than cis-isomers. This was different from that observed in tumor cells in which cis-stilbenes were more potent cytotoxic agents. Trans-3,4',5-trimethoxy-3'-amino-stilbene (TTAS) was the most active stilbene showing in Leishmania infantum a LD(50) value of 2.6 μg/mL. In contrast TTAS showed a low toxicity when tested on normal hemopoietic cells. This compound induced apoptosis in parasites by disrupting the mitochondrial membrane potential. Moreover it shows the ability to block Leishmania parasites in G(2)-M phase of cell cycle in agreement with the data obtained by affinity chromatography that identify tubulin as the putative target of TTAS. In conclusion, our results indicate that some stilbene derivatives are highly effective as anti-leishmanial agents and TTAS represents a pro-apoptotic agent in Leishmania parasites that merit further in vivo investigation

    Lung ultrasound as a predictor of mortality of patients with Covid-19

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    Objective: To evaluate the performance of lung ultrasound to determine short-term outcomes of patients with COVID-19 admitted to the intensive care unit. Methods: This is a Prospective, observational study. Between July and November 2020, 59 patients were included and underwent at least two LUS assessments using LUS score (range 0-42) on day of admission, day 5th, and 10th of admission. Results: Age was 66.5±15 years, APACHE II was 8.3±3.9, 12 (20%) patients had malignancy, 46 (78%) patients had a non‑invasive ventilation/high-flow nasal cannula and 38 (64%) patients required mechanical ventilation. The median stay in ICU was 12 days (IQR 8.5-20.5 days). ICU or hospital mortality was 54%. On admission, the LUS score was 20.8±6.1; on day 5th and day 10th of admission, scores were 27.6±5.5 and 29.4±5.3, respectively (P=0.007). As clinical condition deteriorated the LUS score increased, with a positive correlation of 0.52, P <0.001. Patients with worse LUS on day 5th versus better score had a mortality of 76% versus 33% (OR 6.29, 95%CI 2.01-19.65, p. 0.003); a similar difference was observed on day 10. LUS score of 5th day of admission had an area under the curve of 0.80, best cut-point of 27, sensitivity and specificity of 0.75 and 0.78 respectively. Conclusion: These findings position LUS as a simple and reproducible method to predict the course of COVID-19 patients.Fil: Sosa, Fernando A.. Hospital Alemán; ArgentinaFil: Matarrese, Agustín. Hospital Aleman; ArgentinaFil: Saavedra, Santiago. Hospital Aleman; ArgentinaFil: Osatnik, Javier. Hospital Alemán; ArgentinaFil: Roberti, Javier Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: Tort Oribe, Barbara. Hospital Alemán; ArgentinaFil: Ivulich, Daniel. Hospital Aleman; ArgentinaFil: Durán, Ana Laura. Hospital Alemán; ArgentinaFil: Caputo, Celeste. Hospital Aleman; ArgentinaFil: Benay, Cristian Gabriel. Hospital Alemán; Argentin

    The clinical effectiveness of an integrated multidisciplinary evidence-based program to prevent intraoperative pressure injuries in high-risk children undergoing long-duration surgical procedures: a quality improvement study

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    The prevention of hospital-acquired pressure injuries (HAPIs) in children undergoing long-duration surgical procedures is of critical importance due to the potential for catastrophic sequelae of these generally preventable injuries for the child and their family. Long-duration surgical procedures in children have the potential to result in high rates of HAPI due to physiological factors and the difficulty or impossibility of repositioning these patients intraoperatively. We developed and implemented a multi-modal, multi-disciplinary translational HAPI prevention quality improvement program at a large European Paediatric University Teaching Hospital. The intervention comprised the establishment of wound prevention teams, modified HAPI risk assessment tools, specific education, and the use of prophylactic dressings and fluidized positioners during long-duration surgical procedures. As part of the evaluation of the effectiveness of the program in reducing intraoperative HAPI, we conducted a prospective cohort study of 200 children undergoing long-duration surgical procedures and compared their outcomes with a matched historical cohort of 200 children who had undergone similar surgery the previous year. The findings demonstrated a reduction in HAPI in the intervention cohort of 80% (p &lt; 0.01) compared to the comparator group when controlling for age, pathology, comorbidity, and surgical duration. We believe that the findings demonstrate that it is possible to significantly decrease HAPI incidence in these highly vulnerable children by using an evidence-based, multi-modal, multidisciplinary HAPI prevention strategy

    Beyond trees: Mapping total aboveground biomass density in the Brazilian savanna using high-density UAV-lidar data

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    Tropical savanna ecosystems play a major role in the seasonality of the global carbon cycle. However, their ability to store and sequester carbon is uncertain due to combined and intermingling effects of anthropogenic activities and climate change, which impact wildfire regimes and vegetation dynamics. Accurate measurements of tropical savanna vegetation aboveground biomass (AGB) over broad spatial scales are crucial to achieve effective carbon emission mitigation strategies. UAV-lidar is a new remote sensing technology that can enable rapid 3-D mapping of structure and related AGB in tropical savanna ecosystems. This study aimed to assess the capability of high-density UAV-lidar to estimate and map total (tree, shrubs, and surface layers) aboveground biomass density (AGBt) in the Brazilian Savanna (Cerrado). Five ordinary least square regression models esti-mating AGBt were adjusted using 50 field sample plots (30 m × 30 m). The best model was selected under Akaike Information Criterion, adjusted coefficient of determination (adj.R2), absolute and relative root mean square error (RMSE), and used to map AGBt from UAV-lidar data collected over 1,854 ha spanning the three major vegetation formations (forest, savanna, and grassland) in Cerrado. The model using vegetation height and cover was the most effective, with an overall model adj-R2 of 0.79 and a leave-one-out cross-validated RMSE of 19.11 Mg/ha (33.40%). The uncertainty and errors of our estimations were assessed for each vegetation formation separately, resulting in RMSEs of 27.08 Mg/ha (25.99%) for forests, 17.76 Mg/ha (43.96%) for savannas, and 7.72 Mg/ha (44.92%) for grasslands. These results prove the feasibility and potential of the UAV-lidar technology in Cerrado but also emphasize the need for further developing the estimation of biomass in grasslands, of high importance in the characterization of the global carbon balance and for supporting integrated fire management activities in tropical savanna ecosystems. Our results serve as a benchmark for future studies aiming to generate accurate biomass maps and provide baseline data for efficient management of fire and predicted climate change impacts on tropical savanna ecosystems

    Il progetto Lab2Go per la diffusione della pratica laboratoriale nelle Scuole Secondarie di II grado

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    Even if laboratory practice is essential for all scientific branches of knowledge, it is often neglected at High School, due to lack of time and/or resources. To establish a closer contact between school and experimental sciences, Sapienza Università di Roma and the Istituto Nazionale di Fisica Nucleare (INFN) launched the Lab2Go project, with the goal of spreading laboratory practice among students and teachers in high schools
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