103 research outputs found
Análisis, diseño y construcción de una bomba de calor residencial
The following case study presents the analysis, design and construction of a residential heat pump to heat water. The thermodynamic analysis is done to determine the operating conditions and the required design features with respect of the pressures and the temperatures of the working fluid (R134a). With the thermodynamic parameters, process is continued with the required heat transfer analysis in order to heat up 20 gallons of water in 1.5 hours, resulting in Q ̇_H=1.1704kW...El siguiente estudio presenta el análisis, diseño y construcción de una bomba de calor residencial para el calentamiento de agua. Se realiza un análisis termodinámico para determinar las condiciones de operación y de diseño necesarias de la bomba de calor en términos de presiones y temperaturas para el fluido de trabajo (R134a). Con los parámetros termodinámicos se procede al análisis de transferencia de calor requerido para calentar 20 galones de agua en 1.5 horas, resultando en Q ̇_H=1.1704kW..
Penicillin Binding Proteins as Danger Signals: Meningococcal Penicillin Binding Protein 2 Activates Dendritic Cells through Toll-Like Receptor 4
Neisseria meningitidis is a human pathogen responsible for life-threatening inflammatory diseases. Meningococcal penicillin-binding proteins (PBPs) and particularly PBP2 are involved in bacterial resistance to β-lactams. Here we describe a novel function for PBP2 that activates human and mouse dendritic cells (DC) in a time and dose-dependent manner. PBP2 induces MHC II (LOGEC50 = 4.7 µg/ml±0.1), CD80 (LOGEC50 = 4.88 µg/ml±0.15) and CD86 (LOGEC50 = 5.36 µg/ml±0.1). This effect was abolished when DCs were co-treated with anti-PBP2 antibodies. PBP2-treated DCs displayed enhanced immunogenic properties in vitro and in vivo. Furthermore, proteins co-purified with PBP2 showed no effect on DC maturation. We show through different in vivo and in vitro approaches that this effect is not due to endotoxin contamination. At the mechanistic level, PBP2 induces nuclear localization of p65 NF-kB of 70.7±5.1% cells versus 12±2.6% in untreated DCs and needs TLR4 expression to mature DCs. Immunoprecipitation and blocking experiments showed tha
Differential Modulation of TNF-α–Induced Apoptosis by Neisseria meningitidis
Infections by Neisseria meningitidis show duality between frequent asymptomatic carriage and occasional life-threatening disease. Bacterial and host factors involved in this balance are not fully understood. Cytopathic effects and cell damage may prelude to pathogenesis of isolates belonging to hyper-invasive lineages. We aimed to analyze cell–bacteria interactions using both pathogenic and carriage meningococcal isolates. Several pathogenic isolates of the ST-11 clonal complex and carriage isolates were used to infect human epithelial cells. Cytopathic effect was determined and apoptosis was scored using several methods (FITC-Annexin V staining followed by FACS analysis, caspase assays and DNA fragmentation). Only pathogenic isolates were able to induce apoptosis in human epithelial cells, mainly by lipooligosaccharide (endotoxin). Bioactive TNF-α is only detected when cells were infected by pathogenic isolates. At the opposite, carriage isolates seem to provoke shedding of the TNF-α receptor I (TNF-RI) from the surface that protect cells from apoptosis by chelating TNF-α. Ability to induce apoptosis and inflammation may represent major traits in the pathogenesis of N. meningitidis. However, our data strongly suggest that carriage isolates of meningococci reduce inflammatory response and apoptosis induction, resulting in the protection of their ecological niche at the human nasopharynx
Frequent capsule switching in 'ultra-virulent' meningococci - Are we ready for a serogroup B ST-11 complex outbreak?
The meningococcal ST-11 complex (cc11) causes large invasive disease outbreaks with high case fatality rates, such as serogroup C (MenC) epidemics in industrialised nations in the 1990s and the serogroup W epidemic currently expanding globally. Glycoconjugate vaccines are available for serogroups A, C, W and Y. Broad coverage protein-based vaccines have recently been licensed against serogroup B meningococci (MenB), however, these do not afford universal MenB protection. Capsular switching from MenC to MenB among cc11 organisms is concerning because a large MenB cc11 (B:cc11) outbreak has the potential to cause significant morbidity and mortality. This study aimed to assess the potential for licensed and developmental non-capsular meningococcal vaccines to protect against B:cc11. The population structure and vaccine antigen distribution was determined for a panel of >800 geo-temporally diverse, predominantly MenC cc11 and B:cc11 genomes. The two licensed vaccines potentially protect against many but not all B:cc11 meningococci. Furthermore, strain coverage by these vaccines is often due to a single vaccine antigen and both vaccines are highly susceptible to vaccine escape owing to the apparent dispensability of key proteins used as vaccine antigens. cc11 strains with MenB and MenC capsules warrant special consideration when formulating future non-capsular meningococcal vaccines
Experimental Meningococcal Sepsis in Congenic Transgenic Mice Expressing Human Transferrin
Severe meningococcal sepsis is still of high morbidity and mortality. Its management may be improved by an experimental model allowing better understanding of its pathophysiology. We developed an animal model of meningococcal sepsis in transgenic BALB/c mice expressing human transferrin. We studied experimental meningococcal sepsis in congenic transgenic BALB/c mice expressing human transferrin by transcriptional profiling using microarray analysis of blood and brain samples. Genes encoding acute phase proteins, chemokines and cytokines constituted the largest strongly regulated groups. Dynamic bioluminescence imaging further showed high blood bacterial loads that were further enhanced after a primary viral infection by influenza A virus. Moreover, IL-1 receptor–associated kinase–3 (IRAK-3) was induced in infected mice. IRAK-3 is a negative regulator of Toll-dependant signaling and its induction may impair innate immunity and hence result in an immunocompromised state allowing bacterial survival and systemic spread during sepsis. This new approach should enable detailed analysis of the pathophysiology of meningococcal sepsis and its relationships with flu infection
Diagnostic investigation of 100 cases of abortion in sheep in Uruguay: 2015-2021
The aim of this work was to identify causes of abortion through laboratory investigations in sheep flocks in Uruguay. One hundred cases of abortion, comprising 58 fetuses, 36 fetuses with their placentas, and 6 placentas were investigated in 2015-2021. Cases were subjected to gross and microscopic pathologic examinations, and microbiological and serological testing for the identification of causes of abortion, including protozoal, bacterial, and viral pathogens. An etiologic diagnosis was determined in 46 (46%) cases, including 33 (33%) cases caused by infectious pathogens, as determined by the detection of a pathogen along with the identification of fetoplacental lesions attributable to the detected pathogen. Twenty-seven cases (27%) were caused by Toxoplasma gondii, 5 (5%) by Campylobacter fetus subspecies fetus, and 1 (1%) by an unidentified species of Campylobacter. Fourteen cases (14%) had inflammatory and/or necrotizing fetoplacental lesions compatible with an infectious etiology. Although the cause for these lesions was not clearly identified, T. gondii was detected in 4 of these cases, opportunistic bacteria (Bacillus licheniformis, Streptococcus sp.) were isolated in 2 cases, and bovine viral diarrhea virus 1 subtype i (BVDV-1i) was detected in another. Campylobacter jejuni was identified in 1 (1%) severely autolyzed, mummified fetus. BVDV-2b was identified incidentally in one fetus with an etiologic diagnosis of toxoplasmosis. Microscopic agglutination test revealed antibodies against ≥1 Leptospira serovars in 15/63 (23.8%) fetuses; however, Leptospira was not identified by a combination of qPCR, culture, fluorescent antibody testing nor immunohistochemistry. Neospora caninum, Chlamydia abortus, Chlamydia pecorum, Coxiella burnetii and border disease virus were not detected in any of the analyzed cases. Death was attributed to dystocia in 13 (13%) fetuses delivered by 8 sheep, mostly from one highly prolific flock. Congenital malformations including inferior prognathism, a focal hepatic cyst, and enterohepatic agenesis were identified in one fetus each, the latter being the only one considered incompatible with postnatal life. Toxoplasmosis, campylobacteriosis and dystocia were the main identified causes of fetal losses. Despite the relatively low overall success rate in establishing an etiologic diagnosis, a systematic laboratory workup in cases of abortion is of value to identify their causes and enables zoonotic pathogens surveillance.INIA: PL_27 N-23398ANII: FCE_3_2018_1_148540ANII: FSA_1_2018_1_15268
Beleza e deficiência visual
Este trabalho questiona a impot1ância da beleza física na sociedade. Essa beleza padronizada pela mídia cria um modelo de corpo ideal, cada vez mais influente na vida e no comportamento das pessoas. Sendo a visão uma fonte de informação importante, questionamos se os cegos também são influenciados e apresentam os mesmos padrões de beleza que os videntes. Sendo assim, este trabalho tem como objetivo compreender o significado do termo beleza para as pessoas cegas. O primeiro momento desse trabalho descreve o desenvolvimento da personalidade, autonomia e auto-estima dos cegos. Em seguida a definição de beleza, os padrões estabelecidos pela sociedade e sua influência na formação da imagem corporal. A finalização se faz ao relacionar as duas primeiras partes e acrescentando um estudo de caso feito com cegos congênitos, onde estes descrevem o que é beleza e se esta tem influência em seus comportamentos. Dessa forma, este trabalho refletiu a importância dos pais, educadores e pesquisadores no desenvolvimento social c cognitivo dos cegos.This work questions the importance of the physical beauty on society. This media standardized beauty shapes the model of an ideal body, and this ideal has more influence each day on the life and behavior of people. The sight is an important information source, so I wondered if the blind people also are influenced and presents the same beauty standards as the called sighted. Thus, this study aims to understand the meaning of the term beauty for the blind. At first, this work has as purpose to study the development of the personality, autonomy, and self-esteem of the blind. Then, the definition of beauty, the standards established by the society and their influence on the corporal image shaping. In the final chapter, the two previous chapters are associated and a study of case with congenital blind is added, where they describe what is beauty and if\u27 it has some influence in their behaviors. This way, thinking on how the sighted can influence on the general development of blind are very important on the familiar, professional and educational environments
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