159 research outputs found

    Cytological Studies Of Metaplasia

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    Spray Cooling

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    Poliserosite, artrite e doença respiratória em leitões: estudo de caso

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    O complexo da poliserosite em suínos é causado por múltiplos factores, em particular pelo agente Haemophilus parasuis (HPS), que tem vindo a causar vários problemas em suínos, quer ao nível respiratório, quer nas articulações. O agente HPS é o responsável pela Doença de Glässer (DG), caracterizada por uma inflamação generalizada da pleura, pericárdio, peritoneu, membranas sinoviais e meninges, acompanhada pela elevada presença de fibrina. HPS é normalmente um agente secundário causado por algum factor predisponente, como stress, pneumonias ou por algum vírus, em particular o Vírus do Síndrome Respiratório e Reprodutor Porcino (PRRSv).No caso das pneumonias verificou-se que o agente HPS é um invasor secundário oportunista e que causa doença em associação com outros agentes víricos ou bacterianos e está associado com maior prevalência de pneumonia por agentes respiratórios víricos, como o Síndrome Respiratório e Reprodutor Porcino (PRRS). Durante este estudo de caso acompanhou-se um lote de leitões desde o desmame até ao final da recria, em que foram feitas serologias e enviados leitões inteiros para laboratório de forma a isolar e identificar o agente. Foi feita a avaliação da morbilidade bem como o cálculo do índice de tosse e taxa de mortalidade nas primeiras quatro semanas de recria. Efectuaram-se necropsias dos leitões deste lote. Pretende-se, como objectivo deste estudo, definir o agente primário causador da patologia, neste caso o PRRSv, bem como a entrada da infecção bacteriana secundária causada pelo HPS. Procedeu-se à vacinação do efectivo frente ao PRRSv. Como profilaxia, devido à falha de protecção de imunidade maternal, fez-se a administração de tulatromicina a todos os leitões até todo o efectivo estar devidamente protegido frente ao PRRSv, conferindo assim uma boa imunidade maternal.The porcine polyserositis complex is caused by multiple factors, particularly by Haemophilus parasuis (HPS), which has been causing several problems in pigs, both at the respiratory and articular levels. HPS is the causative agent of Glässer's Disease (DG), characterized by a generalized inflammation of the pleura, pericardium, peritoneum, synovial membranes and meninges, toguether with an abundant presence of fibrin. HPS is usually a secondary agent enhanced by some predisposing factor, like stress, pneumonia or some viruses, such as Porcine Reproductive and Respiratory Syndrome virus (PRRSv). In pneumonia, it has been show that HPS is an opportunistic secondary invader causing disease in association with other viral or bacterial agents being PRRSv the most prevalent respiratory viral agent found together with HPS. During this study a batch of piglets was followed from weaning until the end of nursery season, when serologies were performed, samples were collected and whole piglets were sent to pathology in order to isolate and identify the agent. Health condition was evaluated as well as the calculation of cough index and mortality rate in the first four weeks of nursery. Necropsies of the piglets of this batch were also carried out.The objective of this study was to define the primary agent causing disease (in this case PRRSv), as well as the factors that predisposed to secondary bacterial infections caused by HPS. Following these findings all herd was vaccinated against PRRSv. Due to lack of protective maternal immunity, tulathromycin was administered in pigs, as prophylactic measure until all sows were adequately protected against PRRSv, thus conferring good maternal immunity to their offspring

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    A multi-ancestry genome-wide study incorporating gene-smoking interactions identifies multiple new loci for pulse pressure and mean arterial pressure

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    Elevated blood pressure (BP), a leading cause of global morbidity and mortality, is influenced by both genetic and lifestyle factors. Cigarette smoking is one such lifestyle factor. Across five ancestries, we performed a genome-wide gene-smoking interaction study of mean arterial pressure (MAP) and pulse pressure (PP) in 129 913 individuals in stage 1 and follow-up analysis in 480 178 additional individuals in stage 2. We report here 136 loci significantly associated with MAP and/or PP. Of these, 61 were previously published through main-effect analysis of BP traits, 37 were recently reported by us for systolic BP and/or diastolic BP through gene-smoking interaction analysis and 38 were newly identified (P <5 x 10(-8), false discovery rate <0.05). We also identified nine new signals near known loci. Of the 136 loci, 8 showed significant interaction with smoking status. They include CSMD1 previously reported for insulin resistance and BP in the spontaneously hypertensive rats. Many of the 38 new loci show biologic plausibility for a role in BP regulation. SLC26A7 encodes a chloride/bicarbonate exchanger expressed in the renal outer medullary collecting duct. AVPR1A is widely expressed, including in vascular smooth muscle cells, kidney, myocardium and brain. FHAD1 is a long non-coding RNA overexpressed in heart failure. TMEM51 was associated with contractile function in cardiomyocytes. CASP9 plays a central role in cardiomyocyte apoptosis. Identified only in African ancestry were 30 novel loci. Our findings highlight the value of multi-ancestry investigations, particularly in studies of interaction with lifestyle factors, where genomic and lifestyle differences may contribute to novel findings.Peer reviewe

    The impact of tunnel oxide nitridation to reliability performance of charge storage non-volatile memory devices

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    This paper is written to review the development of critical research on the overall impact of tunnel oxide nitridation (TON) with the aim to mitigate reliability issues due to incessant technology scaling of charge storage NVM devices. For more than 30 years, charge storage non-volatile memory (NVM) has been critical in the evolution of intelligent electronic devices and continuous development of integrated technologies. Technology scaling is the primary strategy implemented throughout the semiconductor industry to increase NVM density and drive down average cost per bit. In this paper, critical reliability challenges and key innovative technical mitigation methods are reviewed. TON is one of the major candidates to replace conventional oxide layer for its superior quality and reliability performance. Major advantages and caveats of key TON process techniques are discussed. The impact of TON on quality and reliability performance of charge storage NVM devices is carefully reviewed with emphasis on major advantages and drawbacks of top and bottom nitridation. Physical mechanisms attributed to charge retention and Vt instability phenomenon are also reviewed in this paper

    Threshold voltage instability mechanisms of nitride based charge trap flash memory-A review

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    Technological scaling of charge trap device has become significantly more challenging due to two major physical limits revealed by International Technology Roadmap for Semiconductors (ITRS) 2011, i.e., (1) neighboring bit interference due to consistent shrinking in design floor space; (2) balancing act of ensuring sufficient number of electrons in shrinking storage layer to maintain stable threshold voltage (V-t) against various V-t instability mechanisms. Nitride based charge trap flash (CTF) is one of the better candidates to replace floating gate (FG) flash as the mainstream flash memory technology due to its inherent immunity to point defects and better device scalability. However, post cycled V-t instability in the form of V-t distribution shift and broadening of programmed/erased cells is still genuine reliability concerns for nitride based CTF devices. This is because the shift and broadening of V-t distribution could degrade the operating window and thus caused premature failures of the devices. V-t instability of nitride based CTF memory inevitably introduces statistical fluctuations in V-t distribution of nitride based CTF which is detrimental to its long term data retention performance. The scope of this review paper focuses on critical reliability challenges of future development of nitride based CTF development with emphasis on cell level V-t instability mechanisms. Our review on recent findings of V-t instability mechanisms are useful references for future development of nitride based CTF devices
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