1,410 research outputs found
Mechanical Behavior comparison of aircraft joints modeling / Comparação de comportamento mecânico da modelagem de juntas de aeronaves
The procedure of structural design for aircraft parts is widely known and discussed in the academy and in the industry, although it has been improved along the time. It is based on a detailed process of aerodynamics loads study coupled or not with specifications required by regulatory agencies. Further, several interactions of analysis are done to define the critical stress state of the structure submitted to load conditions, because it is a complex structure that needs to be often improved and updated (considering the requirement of assembly/disassembly simplicity). There are several components in an aircraft attached to each other by the use of fasteners, rivets or nuts made of different materials (aluminum, steel, Inconel among others). In fact, it is not to easy to obtain stress state of the aeronautical structure for real loading conditions. Further, it is also difficult to calculate the load acting on each one of the joints. Several studies were already performed in order to obtain the correct understanding of how actual loads is distributed through the joints. The present work aims to compare results in aircraft joints (focusing in spar and skin regions), considering three levels of fidelity to understand the differences in the structural response using different type of modeling approach. Finite Element Analysis modelings made using Nastran software were performed. Preliminary results show good response agreement even for high and intermediate detail levels. Low detail level present promisor response as a tool for predesign
The Effect of Dynamical Parton Recombination on Event-by-Event Observables
Within a dynamical quark recombination model we explore various proposed
event-by-event observables sensitive to the microscopic structure of the
QCD-matter created at RHIC energies. Charge fluctuations, charge transfer
fluctuations and baryon-strangeness correlations are computed from a sample of
central Au+Au events at the highest RHIC energy available (=200
GeV). We find that for all explored observables, the calculations yield the
values predicted for a quark-gluon plasma only at early times of the evolution,
whereas the final state approaches the values expected for a hadronic gas. We
argue that the recombination-like hadronization process itself is responsible
for the disappearance of the predicted deconfinement signatures. This might
explain why no fluctuation signatures for the transition between quark and
hadronic matter was ever observed in the experimental data up to now. However,
it might also be interpreted as a clear indication for a recombination like
hadronization process at RHIC.Comment: 5 page
Local reactions after the fourth-dose of acellular pertussis vaccine in South Australia
The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.ObjectiveTo assess the reported rate of local reactions after administration of acellular pertussis vaccine (DTPa) according to dose number and type of pertussis vaccine (whole-cell or acellular) used for the primary course, and to document the severity and outcome of fourth-dose local reactions.Design and settingRetrospective review. Reports of adverse events after vaccination in South Australia between 1 January 1997 and 31 December 2000 were reviewed, and a questionnaire administered to all parents who reported a local reaction after the fourth dose of DTPa.Main outcome measuresThe number, and rate per 100 000 administered doses, of local reactions following the primary and booster doses of DTPa, and of local reactions after the fourth-dose in cohorts of children whose primary vaccinations were with either DTPw or DTPa. Redness and/or swelling at the injection site as reported by parents.ResultsOf 581 reported adverse events after vaccination, 138 were local reactions after a pertussis-containing vaccine. Primary vaccinations with DTPa was a significant risk factor for a fourth-dose local reaction (relative risk, 6.7; 95% CI, 2.4-18.5). Parental questionnaires were completed for 45 of the 71 children (63%) with reported local reactions after the fourth dose of DTPa; extensive limb swelling was reported in 8 children (18%) and all except one child had recovered by the time of review.ConclusionsParents should be informed that children receiving booster doses of DTPa vaccine, after primary doses with DTPa, are at increased risk of local reactions (which tend to resolve spontaneously) but not of systemic effects. Studies should be initiated to investigate the pathogenesis and the risk of recurrence of local reactions to further improve vaccination schedules.Michael S Gold, Sara Noonan, Maggi Osbourn, Stella Precepa and Ann E Kemp
Blocking tumor-educated MSC paracrine activity halts osteosarcoma progression
Purpose: Human osteosarcoma is a genetically heterogeneous bone malignancy with poor prognosis despite the employment of aggressive chemotherapy regimens. Because druggable driver mutations have not been established, dissecting the interactions between osteosarcoma cells and supporting stroma may provide insights into novel therapeutic targets.Experimental Design: By using a bioluminescent orthotopic xenograft mouse model of osteosarcoma, we evaluated the effect of tumor extracellular vesicle (EV)-educated mesenchymal stem cells (TEMSC) on osteosarcoma progression. Characterization and functional studies were designed to assess the mechanisms underlying MSC education. Independent series of tissue specimens were analyzed to corroborate the preclinical findings, and the composition of patient serum EVs was analyzed after isolation with size-exclusion chromatography.Results: We show that EVs secreted by highly malignant osteosarcoma cells selectively incorporate a membrane-associated form of TGFβ, which induces proinflammatory IL6 production by MSCs. TEMSCs promote tumor growth, accompanied with intratumor STAT3 activation and lung metastasis formation, which was not observed with control MSCs. Importantly, intravenous administration of the anti-IL6 receptor antibody tocilizumab abrogated the tumor-promoting effects of TEMSCs. RNA-seq analysis of human osteosarcoma tissues revealed a distinct TGFβ-induced prometastatic gene signature. Tissue microarray immunostaining indicated active STAT3 signaling in human osteosarcoma, consistent with the observations in TEMSC-treated mice. Finally, we isolated pure populations of EVs from serum and demonstrated that circulating levels of EV-associated TGFβ are increased in osteosarcoma patients.Conclusions: Collectively, our findings suggest that TEMSCs promote osteosarcoma progression and provide the basis for testing IL6- and TGFβ-blocking agents as new therapeutic options for osteosarcoma patients
A Structure-Based Approach for Detection of Thiol Oxidoreductases and Their Catalytic Redox-Active Cysteine Residues
Cysteine (Cys) residues often play critical roles in proteins, for example, in
the formation of structural disulfide bonds, metal binding, targeting proteins
to the membranes, and various catalytic functions. However, the structural
determinants for various Cys functions are not clear. Thiol oxidoreductases,
which are enzymes containing catalytic redox-active Cys residues, have been
extensively studied, but even for these proteins there is little understanding
of what distinguishes their catalytic redox Cys from other Cys functions.
Herein, we characterized thiol oxidoreductases at a structural level and
developed an algorithm that can recognize these enzymes by (i) analyzing amino
acid and secondary structure composition of the active site and its similarity
to known active sites containing redox Cys and (ii) calculating accessibility,
active site location, and reactivity of Cys. For proteins with known or modeled
structures, this method can identify proteins with catalytic Cys residues and
distinguish thiol oxidoreductases from the enzymes containing other catalytic
Cys types. Furthermore, by applying this procedure to Saccharomyces
cerevisiae proteins containing conserved Cys, we could identify the
majority of known yeast thiol oxidoreductases. This study provides insights into
the structural properties of catalytic redox-active Cys and should further help
to recognize thiol oxidoreductases in protein sequence and structure
databases
How to avoid the inappropriate use of antibiotics in upper respiratory tract infections? A position statement from an expert panel
Introduction: Bacterial resistance burden has increased in the past years, mainly due to inappropriate antibiotic use. Recently it has become an urgent public health concern due to its impact on the prolongation of hospitalization, an increase of total cost of treatment and mortality associated with infectious disease. Almost half of the antimicrobial prescriptions in outpatient care visits are prescribed for acute upper respiratory infections, especially rhinosinusitis, otitis media, and pharyngotonsillitis. In this context, otorhinolaryngologists play an important role in orienting patients and non-specialists in the utilization of antibiotics rationally and properly in these infections. Objectives: To review the most recent recommendations and guidelines for the use of antibiotics in acute otitis media, acute rhinosinusitis, and pharyngotonsillitis, adapted to our national reality. Methods: A literature review on PubMed database including the medical management in acute otitis media, acute rhinosinusitis, and pharyngotonsillitis, followed by a discussion with a panel of specialists. Results: Antibiotics must be judiciously prescribed in uncomplicated acute upper respiratory tract infections. The severity of clinical presentation and the potential risks for evolution to suppurative and non-suppurative complications must be taken into 'consideration'. Conclusions: Periodic revisions on guidelines and recommendations for treatment of the main acute infections are necessary to orient rationale and appropriate use of antibiotics. Continuous medical education and changes in physicians' and patients' behavior are required to modify the paradigm that all upper respiratory infection needs antibiotic therapy, minimizing the consequences of its inadequate and inappropriate use. (C) 2018 Associacao Brasileira de Otorrinolaringologia e Cirurgia Cervico-Facial. Published by Elsevier Editora Ltda. This is an open access article under the CC BY license.Introdução: A resistência bacteriana a antibióticos nos processos infecciosos é um fato crescente nos últimos anos, especialmente devido ao seu uso inapropriado. Ao longo dos anos vem se tornando um grave problema de saúde pública devido ao prolongamento do tempo de internação, elevação dos custos de tratamento e aumento da mortalidade relacionada às doenças infecciosas. Quase a metade das prescrições de antibióticos em unidades de pronto atendimento é destinada ao tratamento de alguma infecção de vias aéreas superiores, especialmente rinossinusites, otite média aguda supurada e faringotonsilites agudas, sendo que uma significativa parcela dessas prescrições é inapropriada. Nesse contexto, os otorrinolaringologistas têm um papel fundamental na orientação de pacientes e colegas não especialistas, para o uso adequado e racional de antibióticos frente a essas situações clínicas. Objetivos: Realizar uma revisão das atuais recomendações de utilização de antibióticos nas otites médias, rinossinusites e faringotonsilites agudas adaptadas à realidade nacional. Método: Revisão na base PubMed das principais recomendações internacionais de tratamentos das infecções de vias aéreas superiores, seguido de discussão com um painel de especialistas. Resultados: Os antibióticos devem ser utilizados de maneira criteriosa nas infecções agudas de vias aéreas superiores não complicadas, a depender da gravidade da apresentação clínica e dos potenciais riscos associados de complicações supurativas e não supurativas. Conclusões: Constantes revisões a respeito do tratamento das principais infecções agudas são necessárias para que sejam tomadas medidas coletivas no uso racional e apropriado de antibióticos. Somente com orientação e transformações no comportamento de médicos e pacientes é que haverá mudanças do paradigma de que toda infecção de vias aéreas superiores deva ser tratada com antibióticos, minimizando por consequência os efeitos de seu uso inadequado.Univ Fed Rio Grande do Sul, Dept Oftalmol & Otorrinolaringol, Fac Med FAMED, Porto Alegre, RS, BrazilUniv Fed Sao Paulo UNIFESP, Dept Otorrinolaringol & Cirurgia Cabeca & Pescoco, EPM, Sao Paulo, SP, BrazilUniv Estadual Campinas, UNICAMP, Dept Otorrinolaringol & Oftalmol, Campinas, SP, BrazilUniv Sao Paulo, FM, Disciplina Otorrinolaringol, Sao Paulo, SP, BrazilUniv Sao Paulo, FM, Otorrinolaringol, Sao Paulo, SP, BrazilHosp Infantil Sabara, Otorrinolaringol, Sao Paulo, SP, BrazilHosp Paranaense Otorrinolaringol IPO, Inst Paranaense Otorrinolaringol, Curitiba, Parana, BrazilFac Ciencias Med Santa Casa de Sao Paulo, Sao Paulo, SP, BrazilUniv Fed Pernambuco UFPE, Dept Cirurgia, Div Otorrinolaringol, Recife, PE, BrazilUniv Luterana Brasil, Fac Med, Porto Alegre, RS, BrazilUniv Sao Paulo, FM, Sao Paulo, SP, BrazilHosp Albert Einstein, Sao Paulo, SP, BrazilUniv Sao Paulo, FMRP, Dept Oftalmol Otorrinolaringol & Cirurgia Cabeca, Ribeirao Preto, SP, BrazilUniv Fed Ciencias Saude Porto Alegre, Hosp Crianca St Antonio, Serv Otorrinolaringol Pediat, Porto Alegre, RS, BrazilUniv Estado Rio De Janeiro, Fac Ciencias Med, Disciplina Otorrinolaringol, Rio De Janeiro, RJ, BrazilUniv Fed Goias, Goiania, Go, BrazilPontificia Univ Catolica Goias PUC GO, Goiania, Go, BrazilCtr Univ Anapolis, Anapolis, Go, BrazilUniv Fed Sao Paulo UNIFESP, Dept Otorrinolaringol & Cirurgia Cabeca & Pescoco, EPM, Sao Paulo, SP, BrazilSciEL
Selective use of percutaneous testis biopsy to optimize IVF-ICSI outcomes: a case series
Cancers of unknown primary origin: current perspectives and future therapeutic strategies
It is widely accepted that systemic neoplastic spread is a late event in tumour progression. However, sometimes, rapidly invasive cancers are diagnosed because of appearance of metastatic lesions in absence of a clearly detectable primary mass. This kind of disease is referred to as cancer of unknown primary (CUP) origin and accounts for 3-5% of all cancer diagnosis. There is poor consensus on the extent of diagnostic and pathologic evaluations required for these enigmatic cases which still lack effective treatment. Although technology to predict the primary tumour site of origin is improving rapidly, the key issue is concerning the biology which drives early occult metastatic spreading. This review provides the state of the art about clinical and therapeutic management of this malignant syndrome; main interest is addressed to the most recent improvements in CUP molecular biology and pathology, which will lead to successful tailored therapeutic options
Serological survey on immunity status against polioviruses in children and adolescents living in a border region, Apulia (Southern Italy)
<p>Abstract</p> <p>Background</p> <p>In 1988 the World Health Assembly adopted the goal to eradicate poliomyelitis by routine immunization using Oral Polio Vaccine (OPV). On 21 June 2002 the WHO European Region was declared polio-free. In 2008 poliomyelitis is still endemic in 4 countries (Nigeria, India, Pakistan, and Afghanistan), where 1201 new cases were registered in 2007; 107 sporadic cases were also notified in countries where poliovirus is not endemic. The aim of this work was to verify the level of antipoliomyelitis immunity status in children and adolescents in the Apulia region (south of Italy), which may be considered a border region due to its position.</p> <p>Methods</p> <p>704 blood specimens from a convenience sample were collected in six laboratories. The age of subjects enrolled was 0–15 years. The immunity against poliomyelitis was evaluated by neutralizing antibody titration in tissue culture microplates.</p> <p>Results</p> <p>Seropositivity (neutralising antibodies titre ≥ 8) for polioviruses 1, 2 and 3 was detected in 100%, 99.8% and 99.4% of collected sera. Antibody titres were not lower in subjects who received either four doses of inactivated polio vaccine (IPV) or a sequential schedule consisting of two doses of IPV and two of oral polio vaccine than in subjects who received four doses of OPV.</p> <p>Conclusion</p> <p>These results confirmed current data of vaccine coverage for poliomyelitis: during the last ten years in Apulia, the coverage in 24 months old children was more than 90%. The high level of immunization found confirms the effectiveness both of the sequential schedule IPV-OPV and of the schedule all-IPV. Apulia region has to face daily arrivals of refugees and remains subject to the risk of the importation of poliovirus from endemic areas. Surveys aimed at determining anti-polio immunity in subpopulations as well as in the general population should be carried out.</p
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