Óxido de calcio para mejorar las propiedades físicas y mecánicas del concreto estructural

Esta investigación lleva como título “Óxido de calcio para mejorar las propiedades físicas y mecánicas del concreto estructural”. Tuvo como objetivo principal analizar el óxido de calcio para mejorar las propiedades físicas y mecánicas del concreto estructural. Esta investigación fue documental - bibliográfica, donde la información fue recolectada de investigaciones nacionales e internacionales, tanto como tesis y artículos. Las investigaciones revisadas utilizaron el método deductivo, enfoque cuantitativo, el diseño experimental, longitudinal y estudio de cohorte. Al realizar la adición el óxido de calcio en porcentajes óptimos a una mezcla de concreto, esta mejora sus propiedades físicas y mecánicas como la trabajabilidad, tiempo de fraguado, resistencia a la compresión. Con respecto a la trabajabilidad se determinó que el porcentaje óptimo fue de 4%, con un asentamiento de 11cm. El porcentaje óptimo para aumentar la resistencia a la compresión fue de 4% con una resistencia de 353 kg/cm². Se determinó que la relación a/c de 0.43 con un porcentaje óptimo de óxido de calcio de 4 % en la mezcla de concreto reduce el tiempo de fraguado a 375 minutos. Finalmente, para una mejor mezcla se utilizó del agregado grueso de tamaño máximo nominal de 12.7 mm., con una resistencia máxima de 353 kg/cm²

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

Perceived Feasibility, Acceptability, and Cultural Adaptation for a Mental Health Intervention in Rural Haiti

Mental healthcare is largely unavailable throughout Haiti, particularly in rural areas. The aim of the current study is to explore perceived feasibility, acceptability, and effectiveness of potential culturally adapted interventions to improve mental health among Haitian women. The study used focus group discussions (n = 12) to explore five potential interventions to promote mental health: individual counseling, income-generating skills training, peer support groups, reproductive health education, and couples' communication training. Findings indicate that individual counseling, support group, and skills training components were generally anticipated to be effective, acceptable, and feasible by both male and female participants. That being said, participants expressed doubts regarding the acceptability of the couples' communication training and reproductive health education due to: a perceived lack of male interest, traditional male and female gender roles, lack of female autonomy, and misconceptions about family planning. Additionally, the feasibility, effectiveness, and acceptability of the components were described as dependent on cost, proximity to participants, and inclusion of a female health promoter that is known in the community. Given the lack of research on intervention approaches in Haiti, particularly those targeting mental health, this study provides a foundation for developing prevention and treatment approaches for mental distress among Haitian women

Imaging the neural circuitry and chemical control of aggressive motivation

<p>Abstract</p> <p>Background</p> <p>With the advent of functional magnetic resonance imaging (fMRI) in awake animals it is possible to resolve patterns of neuronal activity across the entire brain with high spatial and temporal resolution. Synchronized changes in neuronal activity across multiple brain areas can be viewed as functional neuroanatomical circuits coordinating the thoughts, memories and emotions for particular behaviors. To this end, fMRI in conscious rats combined with 3D computational analysis was used to identifying the putative distributed neural circuit involved in aggressive motivation and how this circuit is affected by drugs that block aggressive behavior.</p> <p>Results</p> <p>To trigger aggressive motivation, male rats were presented with their female cage mate plus a novel male intruder in the bore of the magnet during image acquisition. As expected, brain areas previously identified as critical in the organization and expression of aggressive behavior were activated, e.g., lateral hypothalamus, medial basal amygdala. Unexpected was the intense activation of the forebrain cortex and anterior thalamic nuclei. Oral administration of a selective vasopressin V_1areceptor antagonist SRX251 or the selective serotonin reuptake inhibitor fluoxetine, drugs that block aggressive behavior, both caused a general suppression of the distributed neural circuit involved in aggressive motivation. However, the effect of SRX251, but not fluoxetine, was specific to aggression as brain activation in response to a novel sexually receptive female was unaffected.</p> <p>Conclusion</p> <p>The putative neural circuit of aggressive motivation identified with fMRI includes neural substrates contributing to emotional expression (i.e. cortical and medial amygdala, BNST, lateral hypothalamus), emotional experience (i.e. hippocampus, forebrain cortex, anterior cingulate, retrosplenial cortex) and the anterior thalamic nuclei that bridge the motor and cognitive components of aggressive responding. Drugs that block vasopressin neurotransmission or enhance serotonin activity suppress activity in this putative neural circuit of aggressive motivation, particularly the anterior thalamic nuclei.</p