536 research outputs found

    Arroz más nutritivo contra la desnutrición en América Latina

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    More nutritive rice against malnutrition in Latin America Three topics are addressed briefly: (1) information available on the Fe and Zn contents of the grain of 11 rice cultivars; (2) factors affecting its contents; and (3) a plant breeding strategy proposed to increase the nutritional value of rice in Latin America. The data obtained are backed up by results obtained by the International Rice Research Institute (IRRI) and reveal significant differences among cultivars regarding rice grain Fe and Zn contents in both rough and polished rice. Acceptable Fe and Zn contents were also observed in several commercial varieties; these, however, were never selected to improve this aspect of nutritional quality. Recent scientific data indicate that plant breeding is an effective and reliable tool of reasonable cost to develop improved germplasm with a better nutritional value than current varieties. Research conducted by IRRI, within the framework of the HarvestPlus project, and by CIAT, through the AgroSalud project, indicates that genetic variability does exist in rice regarding grain Fe and Zn contents. In conclusion, it is considered feasible to improve the nutritional quality of rice in Latin America, and advances have been made in several areas.Se tratan brevemente tres temas: 1) la información disponible sobre el contenido de hierro (Fe) y zinc (Zn) del grano en 11 cultivares de arroz; 2) los factores que afectan ese contenido; y 3) una estrategia de fitomejoramiento que se propone para incrementar el valor nutricional del arroz en América Latina. Los datos obtenidos, que son sustentados por los resultados del Instituto Internacional de Investigaciones sobre el Arroz (IRRI), indican diferencias significativas entre los cultivares respecto al contenido de Fe y de Zn del grano, tanto en el arroz integral como en el arroz pulido. Se observó además un contenido aceptable de Fe y de Zn en algunas variedades comerciales; éstas, sin embargo, nunca fueron seleccionadas para mejorar este aspecto de su calidad nutricional. Datos científicos recientes indican que el fitomejoramiento es una herramienta eficaz, confiable y de costo razonable para desarrollar germoplasma mejorado, cuyo valor nutricional sea mayor que el de las variedades corrientes. Las investigaciones realizadas por el IRRI, en el marco del proyecto HarvestPlus, y por el CIAT, a través del proyecto AgroSalud, indican que hay variabilidad genética en el arroz respecto al contenido de Fe y de Zn de su grano. En conclusión, se considera que es factible mejorar la calidad nutricional del arroz en América Latina, tarea en la que se ha logrado avanzar en diversas direcciones

    Methods for Caries Prevention in Children Reported by Dentists from a Brazilian Community

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    Objective: To describe the dental practice patterns related to caries prevention in children aged 6-18 years and associated factors. Material and Methods: Dentists (n=162) from Araraquara, Brazil, completed two paper questionnaires: (1) one about characteristics of their practice and their patient population; and (2) a translated version of the “Assessment of Caries Diagnosis and Caries Treatment” Questionnaire from the National Dental Practice-Based Research Network. Regression analyses were used for data analysis (p<0.05). Results: Dentists reported using in-office fluoride (IOF) and dental sealants (DS) in 74.2% and 45.1% of their pediatric patients, respectively. Regression analysis showed that female dentists (p=0.035 for DS; p=0.044 for IOF; p=0.011 for non-prescription fluoride rinse), those with advanced degrees (p=0.032 for prescription of fluoride), those who graduated from a private dental school (p=0.018 for chlorhexidine rinse), those who provided caries prevention regimens (p<0.001 for DS; p=0.004 for IOF; p=0.013 for non-prescription fluoride rinse), those with a greater percentage of patients interested in a caries prevention regimen (p=0.007 for non-prescription fluoride rinse), those working in a private practice model (p=0.047 for prescription of fluoride) were more likely to recommend some type of preventive methods to their pediatric patients. Conclusion: Dentists reported recommending IOF to most of their pediatric patients. Certain dentists’, practices’, and patients’ characteristics were associated to some caries prevention regimens recommended by dentists

    USANDO ARDUINO COMO FERRAMENTA DE ENSINO NO LABORATÓRIO DE FÍSICA: CARGA-DESCARGA DO CAPACITOR

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    This paper presents an experiment involving assembling a capacitor charge and discharge circuit using Arduino. The goal is to integrate technological resources for teaching physics to enable students to become qualified technology users. It is based on the concepts of digital culture or cyberculture, which encompasses the use of digital technologies in various aspects of everyday life. It provides a didactic intervention to promote competence, skills, and abilities supported using technology. We conclude that it is essential that teachers are prepared to offer students possibilities of didactic experiences that integrate technology in all phases of education.Neste trabalho apresenta-se um experimento que envolve a montagem de um circuito de carga e descarga de capacitor utilizando o Arduino. O objetivo é integrar o uso de recurso tecnológico para o ensino de física de modo a possibilitar aos alunos tornarem-se usuários qualificados das tecnologias. Toma-se por base os conceitos de cultura digital ou cibercultura o que engloba a utilização de tecnologias digitais em diversos aspectos da vida cotidiana. Proporciona-se assim uma intervenção didática no sentido de promover competência, habilidades com suporte ao uso de tecnologia. Conclui-se que é essencial que os professores estejam preparados para oferecer aos alunos possibilidades de experiências didáticas que integrem tecnologia em todas as fases do ensino

    Estudo in vitro da ação do EDTA nas concentrações de 3%, 5%, 10% e 17% sobre a camada residual

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    The success of microbial disinfection of the endodontic space depends on the endodontic instruments, the ancillary chemicalsselected and the technical skills used in the chemical-mechanical preparation. Upon completion of the instrumentation thedeposition on the dentine surface of an organic and inorganic material extract of amorphous aspect, with an irregular andgranular surface known as residual layer, was observed. Aiming at removal of this layer several chemicals, in differentconcentrations and applied in pre-established time intervals were used alone, conjugated or mixed. The objective of this studywas to analyze, in vitro, through scanning electron microscopy, the effect of EDTA in 3%, 5%, 10% and 17% concentrations onthe removal of the residual layer and cleaning of the dentine tubules through applications ranging from 1 to 3 minutes. Eightunits from an 80-tooth sample were randomly selected to compose the negative control set (GC1) and other 8 units to composethe positive control set (GC2). The remaining 64 composed the 8 experimental sets (GExp.). Analysis of the photomicrographsat magnitude 2000X revealed that the 10 % and 17 % EDTA solutions were the most effective irrespective of the pre-establishedapplication times. It was also observed that the apical third showed a lower degree of cleaning than the cervical and basalthirds.O êxito da desinfecção do espaço endodôntico depende dos instrumentos endodônticos, das substâncias químicas auxiliaresselecionadas e da habilidade técnica no preparo químico mecânico. Concluída a instrumentação, é possível constatar adeposição na superfície dentinária de um extrato de material orgânico e inorgânico de aparência amorfa, superfície irregulare granulosa, denominada camada residual. Com este estudo, buscou-se analisar, in vitro, por meio da Microscopia Eletrônicade Varredura, o efeito do EDTA nas concentrações de 3%, 5%, 10% e 17%, na remoção da camada residual e na desobstruçãodos túbulos dentinários, nos tempos de 1 e 3 minutos. Da amostra constituída de 80 dentes, foram selecionados,randomicamente, 8 unidades para composição do grupo de controle negativo (GC1) e 8 para o grupo de controle positivo(GC2). Os 64 restantes compuseram os 8 grupos experimentais(GExp.). A análise das fotomicrografias com magnitude de2000X revelou que as soluções de EDTA a 10% e 17% foram as mais eficazes e que o terço apical apresentou grau de limpezainferior aos terços cervical e médio

    Mucopolysaccharidosis I, II, and VI: Brief review and guidelines for treatment

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    Mucopolysaccharidoses (MPS) are rare genetic diseases caused by the deficiency of one of the lysosomal enzymes involved in the glycosaminoglycan (GAG) breakdown pathway. This metabolic block leads to the accumulation of GAG in various organs and tissues of the affected patients, resulting in a multisystemic clinical picture, sometimes including cognitive impairment. Until the beginning of the XXI century, treatment was mainly supportive. Bone marrow transplantation improved the natural course of the disease in some types of MPS, but the morbidity and mortality restricted its use to selected cases. The identification of the genes involved, the new molecular biology tools and the availability of animal models made it possible to develop specific enzyme replacement therapies (ERT) for these diseases. At present, a great number of Brazilian medical centers from all regions of the country have experience with ERT for MPS I, II, and VI, acquired not only through patient treatment but also in clinical trials. Taking the three types of MPS together, over 200 patients have been treated with ERT in our country. This document summarizes the experience of the professionals involved, along with the data available in the international literature, bringing together and harmonizing the information available on the management of these severe and progressive diseases, thus disclosing new prospects for Brazilian patients affected by these conditions

    Sarilumab in patients admitted to hospital with severe or critical COVID-19: a randomised, double-blind, placebo-controlled, phase 3 trial

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    Background: Elevated proinflammatory cytokines are associated with greater COVID-19 severity. We aimed to assess safety and efficacy of sarilumab, an interleukin-6 receptor inhibitor, in patients with severe (requiring supplemental oxygen by nasal cannula or face mask) or critical (requiring greater supplemental oxygen, mechanical ventilation, or extracorporeal support) COVID-19. Methods: We did a 60-day, randomised, double-blind, placebo-controlled, multinational phase 3 trial at 45 hospitals in Argentina, Brazil, Canada, Chile, France, Germany, Israel, Italy, Japan, Russia, and Spain. We included adults (≥18 years) admitted to hospital with laboratory-confirmed SARS-CoV-2 infection and pneumonia, who required oxygen supplementation or intensive care. Patients were randomly assigned (2:2:1 with permuted blocks of five) to receive intravenous sarilumab 400 mg, sarilumab 200 mg, or placebo. Patients, care providers, outcome assessors, and investigators remained masked to assigned intervention throughout the course of the study. The primary endpoint was time to clinical improvement of two or more points (seven point scale ranging from 1 [death] to 7 [discharged from hospital]) in the modified intention-to-treat population. The key secondary endpoint was proportion of patients alive at day 29. Safety outcomes included adverse events and laboratory assessments. This study is registered with ClinicalTrials.gov, NCT04327388; EudraCT, 2020-001162-12; and WHO, U1111-1249-6021. Findings: Between March 28 and July 3, 2020, of 431 patients who were screened, 420 patients were randomly assigned and 416 received placebo (n=84 [20%]), sarilumab 200 mg (n=159 [38%]), or sarilumab 400 mg (n=173 [42%]). At day 29, no significant differences were seen in median time to an improvement of two or more points between placebo (12·0 days [95% CI 9·0 to 15·0]) and sarilumab 200 mg (10·0 days [9·0 to 12·0]; hazard ratio [HR] 1·03 [95% CI 0·75 to 1·40]; log-rank p=0·96) or sarilumab 400 mg (10·0 days [9·0 to 13·0]; HR 1·14 [95% CI 0·84 to 1·54]; log-rank p=0·34), or in proportions of patients alive (77 [92%] of 84 patients in the placebo group; 143 [90%] of 159 patients in the sarilumab 200 mg group; difference −1·7 [−9·3 to 5·8]; p=0·63 vs placebo; and 159 [92%] of 173 patients in the sarilumab 400 mg group; difference 0·2 [−6·9 to 7·4]; p=0·85 vs placebo). At day 29, there were numerical, non-significant survival differences between sarilumab 400 mg (88%) and placebo (79%; difference +8·9% [95% CI −7·7 to 25·5]; p=0·25) for patients who had critical disease. No unexpected safety signals were seen. The rates of treatment-emergent adverse events were 65% (55 of 84) in the placebo group, 65% (103 of 159) in the sarilumab 200 mg group, and 70% (121 of 173) in the sarilumab 400 mg group, and of those leading to death 11% (nine of 84) were in the placebo group, 11% (17 of 159) were in the sarilumab 200 mg group, and 10% (18 of 173) were in the sarilumab 400 mg group. Interpretation: This trial did not show efficacy of sarilumab in patients admitted to hospital with COVID-19 and receiving supplemental oxygen. Adequately powered trials of targeted immunomodulatory therapies assessing survival as a primary endpoint are suggested in patients with critical COVID-19. Funding: Sanofi and Regeneron Pharmaceuticals

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

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    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe
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