WorldWideScience

Sample records for experimental models estudo

  1. Modelo experimental para o estudo da hérnia do disco intervertebral Experimental model to study intervertebral disc herniation

    Directory of Open Access Journals (Sweden)

    André Luiz de Souza Grava

    2008-04-01

    Full Text Available OBJETIVO: Apresentar um modelo experimental de hérnia de disco e sua validação para estudo da hiperalgesia mecânica e térmica produzidas pelo contato do núcleo pulposo (NP com as estruturas nervosas envolvidas nessa afecção. MÉTODOS: Foram utilizados ratos Wistar, sendo o NP autólogo retirado da região sacrococcígea e depositado sobre a dura-máter, raiz nervosa ou gânglios das raízes dorsais L4, L5 ou L6. Os experimentos foram divididos em quatro etapas: 1ª determinação da estrutura nervosa mais sensível ao contato com o NP; 2ª identificação do melhor nível lombar para a indução da hiperalgesia; 3ª determinação da ausência de lesão motora; e 4ª determinação da influência do procedimento cirúrgico no desenvolvimento do processo inflamatório. A hiperalgesia foi avaliada nos testes de von Frey eletrônico e de Hargreaves e a função motora, pelo teste de rota-rod. RESULTADOS: O NP induziu hiperalgesia de maior intensidade na pata quando em contato com o gânglio da raiz dorsal (GRD do que em contato com a dura-máter ou a raiz nervosa. Quando em contato com o GRD-L5, o NP induziu hiperalgesia ainda maior que a induzida pelo contato com os GRDs L4 e L6. Não foram observadas lesão motora e influência do processo inflamatório cirúrgico sobre a hiperalgesia. CONCLUSÃO: O GRD é a estrutura mais sensível aos componentes do NP para a produção da hiperalgesia, sendo o quinto nível lombar o que apresentou maior alteração nas sensibilidades mecânica e térmica avaliadas na pata dos animais, de acordo com os métodos utilizados.OBJECTIVE:The purpose of this study is to present an experimental model of disc herniation and to validate such model to study mechanic and thermal hyperalgesia produced by the contact of the nucleus pulposus (NP with nerve structures involved in this condition. METHODS: The authors used Wistar rats, the autologous NP being removed from the sacrococcygeal region and deposited on the

  2. O Mastomys natalensis como modelo alternativo nos estudos da esquistossomose mansoni experimental Mastomys natalensis as alternative model in studies on experimental schistosomiasis mansoni

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Moreira Campos

    1984-02-01

    Full Text Available Foram estudados aspectos da infecção e da imunidade experimentais em um roedor — o Mastomys natalensis — inoculado com a cepa LE (Belo Horizonte do Schistosoma mansoni, comparando os resultados com os do camundongo albino, animal tido como melhor modelo experimental. Os parâmetros estudados ofereceram resultados em tudo semelhantes aos encontrados em camundongos, com o M. natalensis se mostrando bastante sensível à infecção pelo S. mansoni, sendo de grande utilidade para os estudos da biologia do parasito e/ou observações da imu-nologia advinda da infecção. Somando-se a tal fato a grande reprodutividade do animal em cativeiro, a criação fácil, o manejo e a manutenção simples em laboratório, sugere-se que seja o M. natalensis usado como modelo experimental alternativo nos diversos estudos da esquistossomose mansoni.It was studied aspects of experimental infection and immunity in a rodent — Mastomys natalensis — infected by the LE strain of Schistosoma mansoni. The results were compared with those from albino mouse, that is an excellent animal for experimental schistosomiasis. The studied parameters showed similar results to those found in the mouse. M. natalensis is highly susceptible to S. mansoni infection, being very useful for biological studies and/or immunity observations about this kind of infection. In addition, the high reproduction rate in captivity, easy handling and unexpensive maintenance in laboratory, suggest that M. natalensis could be used as an alternative experimental model in schistosomiasis mansoni studies.

  3. Implante Autólogo Ovariano no Omento Maior: Estudo Experimental Ovarian Autotransplantation to the Greater Omentum: Experimental Model

    Directory of Open Access Journals (Sweden)

    Luiz Ronaldo Alberti

    2002-01-01

    Full Text Available Objetivos: avaliar os aspectos morfofuncionais de ovários implantados no omento maior, bem como a melhor técnica para implantação do ovário: se íntegro ou fatiado. Métodos: foram divididas aleatoriamente 40 ratas Wistar com ciclos estrais normais em quatro grupos: Grupo I (n = 5, controle - laparotomia; Grupo II (n = 5, ooforectomia total bilateral; Grupo III (n = 15, implante autólogo íntegro no omento maior e Grupo IV (n = 15, implante autólogo fatiado no omento maior. Realizaram-se esfregaços vaginais nos 3º e 6º mes pós-operatório e estudos histológicos dos implantes ovarianos, avaliando-se: degeneração, fibrose, reação inflamatória, angiogênese, cistos foliculares, desenvolvimento folicular e corpos lúteos. Resultados: os animais do Grupo I ciclaram normalmente. As ratas do Grupo II não apresentaram ciclo, permanecendo em diestro. No Grupo III, 11 ratas permaneceram em diestro, três apresentaram ciclos incompletos e apenas uma ciclou normalmente. No Grupo IV, três animais não ciclaram, oito tiveram esfregaços vaginais incompletos e quatro ciclaram normalmente. Os achados histológicos dos animais pertencentes ao Grupo III evidenciaram histoarquitetura normal em dez ratas, porém nas outras cinco, houve degeneração ovariana. No Grupo IV, 14 ratas tiveram ovários com histoarquitetura preservada e em apenas uma houve sinais de degeneração. Conclusões: o implante autólogo ovariano no omento maior foi viável, obtendo-se melhor preservação morfofuncional com a implantação de fatias.Purpose: in order to maintain the gonadal function after oophorectomy, morphofunctional aspects of ovarian autotransplantation to the greater omentum and the best kind of implantation, intact or sliced, were investigated. Methods: forty cycling female Wistar rats were randomly divided into four groups: Group I (n = 5, control - laparotomy; Group II (n = 5, bilateral oophorectomy; Group III (n = 10, intact ovarian

  4. Achados otomicroscópicos e histológicos da miringoesclerose induzida em ratos: estudo crítico de um modelo experimental Otomicroscopic and histologic findings of induced myringosclerosis in rats: a critical study of an experimental model

    Directory of Open Access Journals (Sweden)

    Patrícia F. Santos

    2005-10-01

    Full Text Available A miringoesclerose é caracterizada por hialinização da lâmina própria da membrana timpânica. Trabalhos experimentais têm utilizado a otomicroscopia ou a histologia para estudar a miringoesclerose em animais, porém sem correlacionar precisamente estes dois métodos de avaliação. OBJETIVO: Este estudo procura avaliar a acurácia da otomicroscopia no diagnóstico de miringoesclerose em modelo experimental com ratos. FORMA DE ESTUDO: experimental. MATERIAL E MÉTODO: Foi induzida miringoesclerose por inoculação transtimpânica de Streptococcus pneumoniae em 25 ratos Wistar, que foram examinados quinzenalmente por otomicroscopia e sacrificados após oito semanas, tendo suas membranas timpânicas examinadas por histologia. RESULTADOS: Da confrontação das alterações otomicroscópicas com os achados histológicos, houve uma sensibilidade de 80% e especificidade de 75%. CONCLUSÃO: Pelos resultados obtidos neste estudo, a otomicroscopia não representou um bom método para avaliar a miringoesclerose neste modelo experimental.Myringosclerosis is characterized by hyaline changes of the lamina propria of the tympanic membrane. Experimental studies have used otomicroscopy or histology to evaluate myringosclerosis in animals, but they do not correlate precisely these two methods. AIM: The present study evaluates the accuracy of otomicroscopy in the diagnosis of myringosclerosis in rats. STUDY DESIGN: experimental. MATERIAL AND METHOD: Myringosclerosis was induced by transtympanic inoculation of Streptococcus pneumoniae in 25 Wistar rats, which were examined weekly through otomicroscopy and sacrificed after eight weeks for histologic study of their tympanic membranes. RESULTS: From the comparison of the otomicroscopic data in relation to the histologic findings, we could observe sensibility of 80% and specificity of 75% for the otomicroscopy. CONCLUSION: Considering the results in this study, otomicroscopy did not represent a good method to

  5. Modelo de carcinogênese gástrica utilizando piloroplastia de Finney: estudo experimental em ratos Gastric carcinogenesis model using Finney pyloroplasty: experimental study in rats

    Directory of Open Access Journals (Sweden)

    Eliane de Marco Ferreira Kaminski

    2011-12-01

    estudados. CONCLUSÃO: 1 A piloroplastia à Finney é modelo experimental adequado de carcinogênese gástrica; 2 ela induziu refluxo duodenogástrico; 3 o refluxo duodenogástrico atuou como carcinógeno para o estômago; 4 não houve relação entre o pH gástrico e o desenvolvimento de carcinoma; 5 o nitrito de sódio não atuou como carcinógeno para o estômago dos ratos.BACKGROUND: The duodenogastric reflux has been implicated as a potential carcinogen for the stomach and esophagus and is one of the factors that may explain the development of gastric stump cancer. Experimental models of carcinogenesis in the stomach stump or in the duodenogastric anastomosis are well defined. AIM: To develop an experimental model of gastric carcinogenesis through the Finney pyloroplasty, evaluate the influence of ingestion of sodium nitrite in this model, analyze the concentrations of bile acids and the pH of the stomach. METHODS: A hundred and ten Wistar rats were operated and divided into four groups: Group I (15 rats underwent laparotomy (Sham group; Group II (15 rats underwent laparotomy (Sham and ingestion of sodium nitrite in drinking water; Group III (40 rats submitted to the Finney pyloroplasty and Group IV (40 rats submitted to the Finney pyloroplasty and ingestion of sodium nitrite in drinking water. After 50 weeks of surgery, the rats were sacrificed and samples collected for analysis of gastric pH, dosing of bile acids and histological analysis. RESULTS: The immediate postoperative mortality was 9%, and during the experiment, 10 rats died. The control group (I did not show gastric lesions; the control group with sodium nitrite (II developed papillomas in the pre-stomach in 16.6%; the operated groups with pyloroplasty had adenomas in 10.3% in Group III and 14.2 % in Group IV, and adenocarcinoma in 55.1% in group III and 14.2% in Group IV. The implementation of glands into the submucosa and muscle in the area of anastomosis (mucosa deployment was not sufficient criterion for

  6. Neural mobilization and static stretching in an experimental sciatica model: an experimental study Mobilização neural e alongamento estático em um modelo experimental de ciatalgia: estudo experimental

    Directory of Open Access Journals (Sweden)

    Gladson R. F. Bertolini

    2009-12-01

    Full Text Available OBJECTIVE: To verify the effectiveness of neural mobilization and static stretching in reducing pain in rats submitted to experimental sciatica. METHODS: The rats (n=23 were divided into three groups: sham (SG/n=8, without intervention; stretching (STCG/n=8, treated with static stretching; and neural mobilization (NMG/n=7, treated with neural mobilization. The animals underwent an experimental model of sciatica by compression of the right ischiatic nerve with catgut suture thread. There were five consecutive sessions of treatment that began on the third day after lesion. The pain caused by the sciatica was evaluated by a functional incapacitation test that measured paw elevation time (PET, and values over 10s were indicative of pain. PET was measured at the following moments: before the lesion (M1, immediately before (M2 and after the first session (M3, immediately after the last session (M4 and 24h after the last session (M5. ANOVA was applied with repeated measures and unrepeated measures for intra- and inter-group comparison, respectively. RESULTS: In the SG, post-lesion PETs were greater than M1 (pOBJETIVO: Verificar a eficácia da mobilização neural e do alongamento estático na redução da dor em ratos submetidos à ciática experimental. MÉTODOS: Os ratos (n=23 foram divididos em três grupos: simulacro (GS/n=8, sem intervenção; alongamento (GAL/n=8, tratados com alongamento estático; e mobilização neural (GMN/n=7, tratados com mobilização neural. Submeteram-se os animais a um modelo experimental de ciática, comprimindo o nervo isquiático direito com fio de catgut. Realizaram-se cinco sessões consecutivas de tratamento que se iniciaram no terceiro dia pós-lesão. Avaliou-se a dor, provocada pela ciática, pelo teste de incapacidade funcional que mensurava o tempo de elevação da pata (TEP do animal, e valores maiores que 10 segundos eram indicativos de dor. O TEP foi mensurado nos momentos: antes da lesão (M1

  7. Excision of sclerocorneal limbus in dogs and resulting clinical events: study of an experimental model Excisão do limbo esclerocorneano de cães e eventos clínicos decorrentes: estudo de um modelo experimental

    Directory of Open Access Journals (Sweden)

    A.T.J. Brunelli

    2006-02-01

    Full Text Available The consequences of complete removal of the sclerocorneal limbus epithelium were evaluated, as well as the model for such, in which n-heptanol and superficial keratectomy were used. The association of n-heptanol and keratectomy allowed a complete excision of stem cells. Moreover, the destruction of these cells led to significant tectonic alterations that could be employed as a feasible model for clinical experimentation of corneal transplantation.As conseqüências da completa remoção do epitélio do limbo esclerocorneano foram avaliadas, bem como o modelo utilizado para tal, em que se empregou o n-heptanol e a ceratectomia superficial. O n-heptanol e a ceratectomia associados possibilitaram a completa excisão das células-tronco. Da destruição dessas células decorrem alterações tectônicas significativas factíveis para estudos dos transplantes de córnea.

  8. An experimental model for the study of drug effects on cutaneous healing Modelo experimental para o estudo de efeitos de drogas sobre a cicatrização cutânea

    Directory of Open Access Journals (Sweden)

    Antonio Chiquetti Júnior

    2007-08-01

    Full Text Available PURPOSE: Immunosuppressive agents are known to interfere with the healing of surgical wounds. The increasing use of these drugs warrants a better understanding of their effects on wound healing. The aim of this study was to develop an experimental model that would allow for a reliable and rapid assessment of drug effects on cutaneous wound healing. METHODS: Thirty syngeneic Lewis rats underwent surgical incision on their dorsal region, in the presence or absence of a three-week regimen of immunosuppressant drug therapy (i.e., cyclosporin, azathioprine, and prednisone. Surgical site tissue was collected at intervals over 21 days after surgery and analyzed for cell number and collagen fiber content. Both of these quantitative assessments were performed using digital image capture with the Image Pro Plus 4.5 software. RESULTS: Computerized histomorphometric analyses revealed an apparent inhibition of cellular responses and collagen fiber production in drug-treated animals compared to control animals. CONCLUSION: The experimental model was reproducible, easy to perform, and allowed for quantitative histological evaluations. It may be useful for the study of surgical healing in the presence of other drug classes.OBJETIVO: Várias drogas podem interferir no processo de cicatrização de feridas cirúrgicas, incluindo-se aqui agentes imunossupressores. Devido ao crescimento do número de pessoas tratadas com estas drogas, um modelo experimental, baseado em um sistema computadorizado de avaliação histológica, para verificar os efeitos destas drogas sobre a cicatrização cirúrgica pode se mostrar útil e permitir, também, o estudo das ações de outras drogas sobre este processo. MÉTODOS: Trinta ratos Lewis isogênicos foram submetidos a incisões cirúrgicas na região dorsal e metade deles foi imunossuprimida utilizando-se ciclosporina, azatioprina e prednisona por 3 semanas. Em cinco intervalos de tempo pré-fixados, avaliações histol

  9. Avaliação do comportamento biológico de homoenxertos valvares pulmonares descelularizados: estudo experimental em ovinos Evaluation of the biological behavior of decellularized pulmonary homografts: an experimental sheep model

    Directory of Open Access Journals (Sweden)

    Fábio Binhara Navarro

    2010-09-01

    Full Text Available INTRODUÇÃO: Não havendo um substituto valvar ideal, os homoenxertos criopreservados são considerados uma boa opção, pelo excelente perfil hemodinâmico, baixa incidência de tromboembolismo, resistência a infecções e durabilidade a médio prazo. Porém, estão sujeitos à progressiva degeneração, especialmente em crianças e adultos jovens. Sua antigenicidade desencadeia uma resposta imunológica que contribui para sua degeneração, calcificação e falência. Para diminuir esta antigenicidade, desenvolveu-se o processo de descelularização. Pela ação de detergentes e enzimas, este processo remove os componentes celulares do homoenxerto, diminuindo sua imunogenicidade e, provavelmente, retardando sua degeneração. OBJETIVO: O objetivo deste estudo, experimental e descritivo, é analisar o comportamento histológico e funcional de homoenxertos pulmonares ovinos descelularizados (H-descel por uma nova solução, composta principalmente de dodecil sulfato de sódio a 0,1% e desenvolvida na PUCPR. Para caracterizar este comportamento, serão avaliados o repovoamento celular, a ocorrência de calcificação e a função valvar ao ecocardiograma. MÉTODOS: A amostra foi constituída de oito ovinos, submetidos ao implante de H-descel em posição ortotópica, através de uma toracotomia esquerda, com auxílio de circulação extracorpórea. Os animais foram acompanhados clinicamente e por ecocardiogramas periódicos até o explante, realizados em prazos predefinidos para cada dois animais: sete, 30, 90 e 180 dias. A análise histológica foi realizada por colorações Hematoxilina-eosina, Pentacrômio de Movat e Alizarina Red. RESULTADOS: Todos os animais sobreviveram ao procedimento e atingiram seus períodos de seguimento. Não houve insuficiência ou estenose destes enxertos ao ecocardiograma. Os animais submetidos aos explantes em 90 e 180 dias tiveram significativos ganhos ponderais e estes H-descel aumentaram de diâmetro, sem

  10. Using an experimental model for the study of therapeutic touch Uso de un modelo experimental para estudio sobre el toque terapéutico Utilização de um modelo experimental para estudo sobre o toque terapêutico

    Directory of Open Access Journals (Sweden)

    Daniella Soares dos Santos

    2013-02-01

    Full Text Available OBJECTIVE: to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. METHOD: this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic Touch for 15 minutes during three days. RESULTS: the data showed statistically significant differences in the nociceptive threshold and in the paw circumference of the animals from the experimental group on the second day of the experiment. CONCLUSION: the experiment model involving animals can contribute to study the effects of Therapeutic Touch on inflammation, and adjustments are suggested in the treatment duration, number of sessions and experiment duration.OBJETIVO: verificar si el Modelo de Edema de Pata puede ser utilizado en las investigaciones acerca de los efectos del Toque Terapéutico sobre la inflamación, mensurándose las variables dolor, edema y migración de neutrófilos. MÉTODO: se trata de un estudio piloto, experimental, con 10 ratones machos del mismo linaje genético, divididos en grupo experimental y control, sometidos a inducción química de inflamación local en la pata derecha trasera. O grupo experimental recibió una aplicación diaria de Toque Terapéutico con duración de quince minutos, por tres días. RESULTADOS: Los datos evidenciaron diferencias estadísticamente significativas en el umbral de nocicepción y circunferencia de las patas de los animales del grupo experimental durante el segundo día del experimento. CONCLUSIÓN: El modelo de experimento con animal puede contribuir al estudio de los efectos del Toque Terapéutico sobre la inflamación: se sugiere ajuste en el tiempo de exposición, número de sesiones y

  11. Experimental model for endometriosis. Comparative histological study between the ectopic and eutopic endometrium Modelo experimental de endometriose: estudo histológico comparativo entre o endométrio estópico e o eutópico

    Directory of Open Access Journals (Sweden)

    Cézar Alencar de Lima Rezende

    1997-12-01

    Full Text Available Thyrty-six rats werw implanted with endometrial squares (2 X 2mm to the left parietal peritoneum and the right uterine horn was tied. The rats were mated for 20 days and then sacrificed. Topic and ectopic endometrial histological pattern were compared. There was a correlation between the histological pattern of the autografted endometrium and the eutopic endometrium im most rats, pregnant or not. This suggests that both responded in a similar way to the same endocrine stimuli. The experimental model for endometriosis admiting the histological correlation between the uterine endometrium and the ectopic is factible and it is easy to be repetead.Trinta e seis ratas foram submetidas a implante cirúrgico de retalho endometrial quadrangular (2 x 2mm no peritônio parietal esquerdo e ligadura do corno uterino direito. As ratas foram acasaladas por 20 dias e logo após sacrificadas. Foram comparados o padrão histológico do endométrio eutópico e do ectópico.Houve correspondência entre o padrão histológico do endométrio auto-transplantado e o endométrio eutópico na maioria das ratas, prenhes ou não, sugerindo que ambos responderam de forma semelhante aos mesmo estímulos endócrinos. O modelo experimental de endometriose na rata, permitindo a correlação histológica entre o endométrio uterino e o ectópico, é viável e de fácil repetição.

  12. Vesicular stomatitis virus (indiana 2 serotype as experimental model to study acute encephalitis – morphological features Vírus da estomatite vesicular (sorotipo indiana 2 como modelo experimental para o estudo de encefalite aguda – aspectos morfológicos

    Directory of Open Access Journals (Sweden)

    Florêncio Figueiredo Cavalcanti Neto

    2003-10-01

    Full Text Available The Vesicular Stomatitis Virus (VSV is a Vesiculovirus of the Rhabdoviridae family that infects mammals and causes vesicular lesions similar to those of foot-and-mouth disease. VSV experimental encephalitis can be induced in rodents and the symptoms are similar to those observed in rabies. However, the lesions observed in the animals´ encephalon are different. Inclusion bodies are not observed. There is necrosis, particularly in the region of the olfactory bulb, and, in some cases, ventriculitis. It was observed that the time pattern of VSV dissemination and the morphological aspects of the lesions are similar to those described in literature. The virus seems to be disseminated through the brain ventricles, being multiplied in the ependyma cells and in the neurons, besides using retrograde and anterograde transport. It was noticed that, due to the facility of virus manipulation, this experimental model has been used in innumerable research studies in several fields. If, on the one hand there are plenty of reports on the infection pathogenesis, on the other hand there are many gaps involving, for instance, aspects about virus transmission, recovery of infected animals and participation of glial cells in the acute as well as in the recovery phases.   O vírus da estomatite vesicular (VEV é um Vesiculovírus da família Rhabdoviridae que infecta mamíferos e causa lesões vesiculares semelhantes às observadas na febre aftosa. A encefalite experimental pode ser induzida em roedores e os sintomas são semelhantes aos observados na raiva; entretanto, as lesões observadas no encéfalo dos animais são diferentes. Corpúsculos de inclusão não são observados, há necrose especialmente da região do bulbo olfatório e em alguns casos, ventriculite. Observamos que o padrão temporal de disseminação do VEV e os aspectos morfológicos das lesões são similares aos descritos na literatura. O vírus parece se disseminar através dos ventr

  13. Using an experimental model for the study of therapeutic touch Uso de un modelo experimental para estudio sobre el toque terapéutico Utilização de um modelo experimental para estudo sobre o toque terapêutico

    OpenAIRE

    Daniella Soares dos Santos; Ilda Estéfani Ribeiro Marta; Evelin Capellari Cárnio; Andreza Urba de Quadros; Thiago Mattar Cunha; Emilia Campos de Carvalho

    2013-01-01

    OBJECTIVE: to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. METHOD: this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic...

  14. Implante de tubo valvulado bioprótese "stentless" em posição aórtica: estudo experimental em ovinos A juvenile sheep model for the stentless bioprostheses implanted as aortic root replacements

    Directory of Open Access Journals (Sweden)

    Paulo César SANTOS

    2002-03-01

    Full Text Available INTRODUÇÃO: O tratamento das lesões valvares representa um grande desafio dentro da cirurgia cardiovascular, pois, até os dias atuais, não temos um substituto ideal para as valvas do coração. As próteses atualmente disponíveis apresentam vantagens e desvantagens; as mecânicas exigem anticoagulação definitiva e as biológicas apresentam baixa durabilidade. Para se chegar a um substituto ideal, são necessárias várias fases, desde a escolha e o preparo do material até o implante em animal de grande porte. Esta última é muito importante, pois a escolha do animal deve ser criteriosa. Ovinos juvenís são animais dóceis de fácil manipulação e suas características anatômicas e biológicas se assemelham muito ao que ocorre com o ser humano e as próteses "stentless" são substitutos mais próximos dos homoenxertos. MATERIAL E MÉTODO: Foram operados 30 ovinos juvenís com idade variando de 4,4 a 6,3 meses, peso de 25 a 37 kg, sendo 28 machos. Todos os animais foram submetidos a circulação extracorpórea para implante de bioprótese "stentless" montada em tubo de aorta porcina, com reimplante de artérias coronárias. A operação foi realizada com hipotermia moderada e cardioplegia gelada. O período de seguimento foi de 30 dias e, ao final, realizado ecocardiograma. RESULTADOS: Houve 8 (26,6% óbitos no intra-operatório e 6 (27,7% óbitos no seguimento. O tempo médio de CEC foi de 98 min. Foi realizado ecocardiograma em 16 animais e em nenhum caso foram vistos sinais de endocardite ou outras alterações; a fração média de ejeção foi de 74%. CONCLUSÃO: Este modelo experimental utilizando ovinos para o estudo de biopróteses "stentless" em posição aórtica mostrou-se bem reprodutível e a performance do enxerto bastante factível de ser avaliada, pois ovinos são animais dóceis e de fácil manipulação no seguimento tardio.INTRODUCTION: Often, studies on aortic prosthetic valves analyze their performance not at the

  15. Models of experimental epilepsy

    Directory of Open Access Journals (Sweden)

    Fatih Ekici

    2011-03-01

    Full Text Available Epilepsy is the most common serious neurological conditionin the world, with an estimated prevalence of 1% ofthe population. A large number of experimental modelsof seizure and epilepsy have been developed. These experimentalmodels are elicited by chemical convulsants,electrical stimulation, genetic models, structural lesions,physical stimuli (cold, pressure, hyperthermia, electricalin animals. Well-characterized animal models may allowthe understanding of the basic mechanisms underlyingepileptogenesis (it refers to the alteration of a normalneuronal network into a hyperexcitable network in whichrecurrent, spontaneous seizures occur. Moreover, thesemodels might also prove useful in identifying novel therapeuticapproaches to treatment of epilepsy. J Clin ExpInvest 2011; 2(1: 118-123

  16. Marcas e promoções de varejo: um estudo experimental

    Directory of Open Access Journals (Sweden)

    Leonardo Aureliano-Silva

    2016-10-01

    Full Text Available O principal objetivo desse estudo foi analisar o efeito da marca em promoções de varejo alimentício. Ao total 90 indivíduos participaram da pesquisa. Por meio do método experimental testou-se quatro hipóteses. Verificou-se que uma marca muito reconhecida pelo mercado, influencia significativamente a atratividade e intenção de recomendar a promoção comparada a uma marca pouco reconhecida. Não foi identificada diferença significativa entre a promoção somente do produto e o produto mais a marca pouco reconhecida. Esse estudo contribui para uma melhor compreensão de como marcas fortes no mercado podem ser usadas para atrair a atenção do consumidor em promoções de lojas de varejos situadas em bairros.

  17. O Mastomys natalensis como modelo alternativo nos estudos da esquistossomose mansoni experimental

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Moreira Campos

    1984-02-01

    Full Text Available Foram estudados aspectos da infecção e da imunidade experimentais em um roedor — o Mastomys natalensis — inoculado com a cepa LE (Belo Horizonte do Schistosoma mansoni, comparando os resultados com os do camundongo albino, animal tido como melhor modelo experimental. Os parâmetros estudados ofereceram resultados em tudo semelhantes aos encontrados em camundongos, com o M. natalensis se mostrando bastante sensível à infecção pelo S. mansoni, sendo de grande utilidade para os estudos da biologia do parasito e/ou observações da imu-nologia advinda da infecção. Somando-se a tal fato a grande reprodutividade do animal em cativeiro, a criação fácil, o manejo e a manutenção simples em laboratório, sugere-se que seja o M. natalensis usado como modelo experimental alternativo nos diversos estudos da esquistossomose mansoni.

  18. Estudo Comparativo de Polimerização de Propileno com Diferentes Catalisadores Metalocênicos Através de um Planejamento de Experimentos Comparative Study of Propylene Polymerization with Different Metallocene Catalysts Using a Statistic Experimental Planning Model

    Directory of Open Access Journals (Sweden)

    Maria de Fátima V. Marques

    2002-01-01

    Full Text Available Neste trabalho, o desempenho dos catalisadores SiMe2(Ind2ZrCl2, Et(Ind2ZrCl2, SiMe2(Ind2HfCl2 e Et(Ind2HfCl2 na polimerização de propileno usando MAO como cocatalisador empregando-se um Planejamento estatístico de experimentos foi avaliado. As polimerizações foram realizadas em diferentes temperaturas e razões molares alumínio/metal de transição. O efeito destas variáveis na atividade de cada catalisador e nas características do polipropileno obtido foi melhor investigado utilizando-se os modelos propostos para cada variável. Foram observadas influências significativas das condições experimentais principalmente na atividade catalítica, bem como no peso molecular ponderal médio, temperatura de fusão e percentagem de isotaticidade dos polímeros obtidos. A partir dos modelos propostos através do tratamento estatístico realizado pode-se observar que os catalisadores a base de zircônio são os de maior atividade catalítica, enquanto que os hafnocenos produzem polipropileno com peso molecular mais elevado. Os complexos com ponte dimetil-silânica produziram polipropileno com maior peso molecular, estereorregularidade e maior temperatura de fusão do que os similares com ponte etilidênica.In this work, the performance of the catalysts SiMe2(Ind2ZrCl2, Et(Ind2ZrCl2, SiMe2(Ind2HfCl2 e Et(Ind2HfCl2 on propylene polymerization using MAO as cocatalyst and employing a Statistic Experimental Planning Model was evaluated. The polymerizations were carried out at different temperatures and aluminum/transition metal molar ratios. The effect of these variables on the catalyst activity and on the polymer characteristics was investigated using the proposed models for each variable. A significant influence was observed of the experimental conditions on the catalyst activity in particular, but also on the weight-average molecular weight, melting point and isotacticity of the polypropylenes produced; the statistical analysis with the proposed

  19. Experimental Object-Oriented Modelling

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius

    and discuss techniques for handling and representing uncertainty when modelling in experimental system development. These techniques are centred on patterns and styles for handling uncertainty in object-oriented software architectures. Tools We present the Knight tool designed for collaborative modelling......This thesis examines object-oriented modelling in experimental system development. Object-oriented modelling aims at representing concepts and phenomena of a problem domain in terms of classes and objects. Experimental system development seeks active experimentation in a system development project...... through, e.g., technical prototyping and active user involvement. We introduce and examine “experimental object-oriented modelling” as the intersection of these practices. The contributions of this thesis are expected to be within three perspectives on models and modelling in experimental system...

  20. Comportamentos de ajuda no contexto urbano: um estudo experimental por meio do telefone

    Directory of Open Access Journals (Sweden)

    Abelardo Vinagre da Silva

    Full Text Available Utilitarismo e frieza nas relações pessoais entre habitantes de grandes cidades encontram respaldo em estudos norte-americanos. No Brasil, pouco se sabe sobre este tema. O uso do telefone como instrumento de pesquisa social experimental também não é freqüente em nossa cultura. Procurou-se verificar o nível de ajuda em função do tipo de residência (casa vs. apartamento, localização (centro vs. periferia e gênero de quem pedia ajuda. Utilizando-se o procedimento do 'Número Errado' solicitou-se ajuda por telefone a 320 moradores de duas áreas urbanas. De modo geral, 39,3% das pessoas contatadas ajudaram da maneira solicitada. Tipo de residência e localização não influenciaram a taxa de ajuda, mas mulheres receberam significativamente mais ajuda que os homens. A utilização do telefone como instrumento de pesquisa social mostrou-se possível. Para seu uso experimental discutiram-se alguns cuidados metodológicos.

  1. Análise do comportamento biológico de heteroenxertos descelularizados e homoenxertos criopreservados: estudo em ovinos Decellularized heterografts versus cryopreserved homografts: experimental study in sheep model

    Directory of Open Access Journals (Sweden)

    Sergio Augusto Veiga Lopes

    2009-03-01

    Full Text Available OBJETIVO: Este estudo avalia o comportamento biológico dos heteroenxertos porcinos descelularizados (Grupo Desc comparados com os homoenxertos criopreservados (Grupo Crio implantados em carneiros jovens. MÉTODOS: Foram implantados em cinco animais heteroenxertos pulmonares porcinos descelularizados e em outros cinco, homoenxertos pulmonares criopreservados. Os animais apresentaram seguimento médio de 280 ± 14 dias. O diâmetro valvar foi medido por ecocardiografia, a qual foi realizada no 30º pós-operatório e antes do explante. As valvas foram também avaliadas macroscopicamente. A avaliação histológica foi realizada utilizando-se coloração de H.E., Gomori e Weigert e imunohistoquímica (Fator VIII, CD3, Vimentina e CD68. A quantificação de cálcio foi realizada utilizando-se espectrometria de absorção atômica. RESULTADOS: Houve um óbito no Grupo Desc por endocardite. As valvas do Grupo Crio apresentaram decréscimo na celularidade, enquanto que as valvas do Grupo Desc demonstraram repovoamento da matriz com células endoteliais e intersticiais. No grupo Crio, observou-se perda na densidade e desarranjo da arquitetura das fibras colágenas. A espectrometria de absorção atômica demonstrou maior calcificação no conduto e nas cúspides dos enxertos criopreservados quando comparados aos descelularizados (P=0,016. O diâmetro médio valvar no explante foi significantemente maior no Grupo Desc (P=0,025. CONCLUSÃO: Heteroenxertos descelularizados apresentam um comportamento biológico diferente quando comparados aos homoenxertos criopreservados, tornando-se repovoados por células com características de fibroblastos e células endoteliais. A matriz permaneceu bem preservada, o que possibilitou um processo de regeneração celular.OBJECTIVES: The aim of this study is to assess the biological behaviour of porcine decellularized heterografts (Desc group compared with cryopreserved homografts (Crio group implanted in juvenile sheep

  2. Modelo experimental de fundoplicatura gastroesofágica em ratos: estudo manométrico e histológico do esôfago Experimental model of gastric-esophageal fundoplication in rats: manometric and histological study of the esophagus

    Directory of Open Access Journals (Sweden)

    Sérgio Luis Rocha

    2004-04-01

    Full Text Available OBJETIVO: O presente estudo objetiva avaliar alguns aspectos decorrentes da fundoplicatura em ratos, com técnica de Nissen, através da análise histológica do esôfago distal e estudo manométrico do esfíncter esofágico inferior (EEI, bem como da avaliação da variação do peso dos ratos submetidos ao procedimento, com diferentes dias de evolução. MÉTODOS: Utilizaram-se 70 ratos Wistar, machos, com idade entre 100 e 130 dias e peso entre 250 e 300 g, divididos em dois grupos. O grupo experimento foi composto por 60 ratos, subdivididos em 6 subgrupos de acordo com o tempo de aferição manométrica pós-operatória: 02, 07, 14, 21, 28 e 40 dias, e submetido a fundoplicatura com posterior análise manométrica do EEI e histológica do esôfago distal. O grupo controle foi composto pelos 10 animais restantes, submetido apenas a laparotomia com manipulação da região es��fago-gástrica, e realizaram-se as mesmas análises. RESULTADOS: Evidenciou-se na análise histológica, edema estatisticamente significativo (p=0,0000 nos subgrupos 02 e 07 dias, acompanhado de perda de peso. Observou-se significância estatística no estudo manométrico em todos os subgrupos comparados ao controle (p t c=+2,132. CONCLUSÃO: Após fundoplicatura de Nissen em ratos, a pressão no EEI não retorna aos níveis do controle até o 40º pós-operatório. O edema correlacionado à perda de peso e ao aumento da pressão no EEI pode ser a principal variável relacionada à possível disfagia.PURPOSE: The aim of this experimental study is to evaluate the outcomes of having Nissen fundoplication done on rats through the histological analysis of the distal esophagus and manometric study of the lower esophageal sphincter (LES, as well as the evaluation of weight variation of the rats subjected to this procedure, in distinct days after surgery. METHODS: Have been used 70 male Wistar rats, at the ages of 100 to 130 days , weighing from 250 to 300 grams and divided

  3. Cytogenetics and experimental models.

    Science.gov (United States)

    Toretsky, J A; Helman, L J

    1997-07-01

    The use of cytogenetics has led to significant improvement in the diagnoses and classification of sarcomas. Many of the major sarcomas have been to have characteristic tumor-specific chromosomal translocations that are currently used in the diagnosis of these tumors. In the past year, a subset of Ewing's family of tumors and myxoid liposarcomas, which lack one of the characteristic translocations, were found to carry related translocations. New technologies such as a spectral karyotyping will likely increase out ability to identify additional tumor-specific translocations. The emergence of genetic alterations as prognostic factors, as illustrated by Ewing's family of tumors, osteosarcoma, and p53 expression in soft tissue sarcomas in general, is discussed. The review concludes with laboratory applications derived from either tumor cytogenetic or gene function abnormalities that are related to tumor-specific translocations. It is anticipated that advances in diagnosis, prognosis, and modeling will translate into future therapeutic advances.

  4. PEMFC modeling and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, J.V.C. [Federal University of Parana (UFPR), Curitiba, PR (Brazil). Dept. of Mechanical Engineering], E-mail: jvargas@demec.ufpr.br; Ordonez, J.C.; Martins, L.S. [Florida State University, Tallahassee, FL (United States). Center for Advanced Power Systems], Emails: ordonez@caps.fsu.edu, martins@caps.fsu.edu

    2009-07-01

    In this paper, a simplified and comprehensive PEMFC mathematical model introduced in previous studies is experimentally validated. Numerical results are obtained for an existing set of commercial unit PEM fuel cells. The model accounts for pressure drops in the gas channels, and for temperature gradients with respect to space in the flow direction, that are investigated by direct infrared imaging, showing that even at low current operation such gradients are present in fuel cell operation, and therefore should be considered by a PEMFC model, since large coolant flow rates are limited due to induced high pressure drops in the cooling channels. The computed polarization and power curves are directly compared to the experimentally measured ones with good qualitative and quantitative agreement. The combination of accuracy and low computational time allow for the future utilization of the model as a reliable tool for PEMFC simulation, control, design and optimization purposes. (author)

  5. Experimental Modeling of Dynamic Systems

    DEFF Research Database (Denmark)

    Knudsen, Morten Haack

    2006-01-01

    An engineering course, Simulation and Experimental Modeling, has been developed that is based on a method for direct estimation of physical parameters in dynamic systems. Compared with classical system identification, the method appears to be easier to understand, apply, and combine with physical...

  6. THE EXPERIMENTAL MODEL OF OSTEONECROSIS

    Directory of Open Access Journals (Sweden)

    G. I. Netylko

    2010-01-01

    Full Text Available The experimental investigation for the purpose of modeling of knee osteonecrosis were performed in 36 rats. The chronic renal insufficiency by means of left nephrectomy and electrocoagulation in 25% cortical substance of right kidney was induced before 6 months till experiment with subsequent introduction of 0,1% adrenalin solution and methylprednisolone in paraarticular structures. The results of experiment showed the polyetiologic feature of disease.

  7. Estudo ultrassonográfico morfométrico do fígado e trato biliar de suínos submetidos a obstrução biliar experimental Sonographic morphometry of the liver and biliary tract in porcine models submitted to experimental biliary obstruction

    Directory of Open Access Journals (Sweden)

    Aline Gomes de Campos

    2013-04-01

    Full Text Available OBJETIVO: Comparar as alterações anatômicas decorrentes de um quadro de icterícia obstrutiva experimental induzida em suínos nos períodos pré e pós-operatório por meio de exame ultrassonográfico. MATERIAIS E MÉTODOS: Seis suínos da raça Landrace, com 36 dias de idade, foram submetidos a obstrução biliar completa mediante ligadura do ducto colédoco por cirurgia videolaparoscópica. RESULTADOS: Não ocorreram dificuldades na execução dos procedimentos obstrutivos e a recuperação cirúrgica foi eficiente. Decorridos sete dias, os animais apresentaram icterícia, bilirrubinúria e acolia fecal. O exame ultrassonográfico comparativo permitiu visualizar hepatomegalia, colecistomegalia e aumento no calibre do ducto colédoco em todos os animais, assim como alterações decorrentes da colestase. A avaliação morfométrica revelou aumento significativo nos diâmetros da vesícula biliar e do lobo hepático lateral esquerdo. CONCLUSÃO: Os suínos representam um modelo experimental adequado de icterícia obstrutiva, e o exame ultrassonográfico demonstrou-se sensível e relevante no diagnóstico das alterações decorrentes de obstrução biliar extra-hepática nesses animais.OBJECTIVE: To compare, by means of ultrasonography, pre- and postoperative anatomical changes arising from experimentally induced obstructive jaundice in porcine models. MATERIALS AND METHODS: Six 36-day-old Landrace pigs underwent laparoscopically induced complete biliary obstruction by common bile duct ligation. RESULTS: No difficulty was faced during the procedures and the surgical recovery was uneventful. After seven days, the animals showed jaundice, bilirubinuria and acholic stools. Comparative ultrasonography allowed visualization of hepatomegaly, cholecystomegaly and increased caliber of the common bile duct in all the animals, as well as changes resulting from cholestasis. The morphometric analysis revealed a significant increase in diameter of the

  8. The updated experimental proteinoid model

    Science.gov (United States)

    Fox, S. W.; Nakashima, T.; Przybylski, A.; Syren, R. M.

    1982-01-01

    The experimental proteinoid model includes new results indicating that polymers sufficiently rich in basic amino acid catalyze the synthesis of peptides from ATP and amino acids and of oligonucleotides from ATP. The need for simulation syntheses of amino acids yielding significant proportions of basic amino acids is now in focus. The modeled simultaneous protocellular synthesis of peptides and polynucleotides is part of a more comprehensive proposal for the origin of the coded genetic mechanism. The finding of membrane and action potentials in proteinoid microspheres, with or without added lecithin, is reported. The crucial nature of a nonrandom matrix for protocells is developed.

  9. Microscopia de desfocalização e seus limites de validade: um estudo experimental

    OpenAIRE

    Ulisses Moreira Silveira Andrade

    2010-01-01

    Objetos de fase tornam-se visíveis quando desfocalizados num microscópio óptico operando em campo claro. Esse fenômeno tem grande aplicação no estudo de células e outras amostras biológicas, que se comportam como objetos de fase em um microscópio. A técnica de Microscopia de Desfocalização é conveniente para estes estudos e foi desenvolvida no Laboratório de Física de Sistemas Biológicos da UFMG. A desfocalização do objeto introduz uma diferença de fase entre a luz difratada e a não difratada...

  10. Epithelial Ovarian Cancer Experimental Models

    Science.gov (United States)

    Lengyel, E; Burdette, JE; Kenny, HA; Matei, D; Pilrose, J; Haluska, P.; Nephew, KP; Hales, DB; Stack, MS

    2014-01-01

    Epithelial ovarian cancer (OvCa) is associated with high mortality and, as the majority (>75%) of women with OvCa have metastatic disease at the time of diagnosis, rates of survival have not changed appreciably over 30 years. A mechanistic understanding of OvCa initiation and progression is hindered by the complexity of genetic and/or environmental initiating events and lack of clarity regarding the cell(s) or tissue(s) of origin. Metastasis of OvCa involves direct extension or exfoliation of cells and cellular aggregates into the peritoneal cavity, survival of matrix-detached cells in a complex ascites fluid phase, and subsequent adhesion to the mesothelium lining covering abdominal organs to establish secondary lesions containing host stromal and inflammatory components. Development of experimental models to recapitulate this unique mechanism of metastasis presents a remarkable scientific challenge and many approaches used to study other solid tumors (lung, colon, and breast, for example) are not transferable to OvCa research given the distinct metastasis pattern and unique tumor microenvironment. This review will discuss recent progress in the development and refinement of experimental models to study OvCa. Novel cellular, three-dimensional organotypic, and ex vivo models are considered and the current in vivo models summarized. The review critically evaluates currently available genetic mouse models of OvCa, the emergence of xenopatients, and the utility of the hen model to study OvCa prevention, tumorigenesis, metastasis, and chemoresistance. As these new approaches more accurately recapitulate the complex tumor microenvironment, it is predicted that new opportunities for enhanced understanding of disease progression, metastasis and therapeutic response will emerge. PMID:23934194

  11. Modelização e estudo experimental de óxidos multiferróicos

    CERN Document Server

    Fenta, Abel

    The main goal of this work was the theoretical and experimental study of multiferroics oxides. This particular approach focused mainly on the ferroelectric material barium titanate. The essence of this theoretical study is the ab initio calculation of hiperfine parameters using the Wien2k software. This software, which uses the selfconsistent $LAPW$ method to solve the Kohn-Sham equations, allowed to determine the electric field gradient and the BaTiO$_3$ system’s total energy in its different structural phases, and study its behaviour in function of the different lattice parameters. The modeling of stratified systems of the (XTiO$_3$).(BaTiO$_3$)$_{n-1}$ and (BaZO$_3$).(BaTiO$_3$ )$_{n-1}$, with X=Cd and Hg and Z=Fe, from n=2 to n=6 type, built from the experimental latice parameters (formula) in the tetragonal sage was also made. This simulation can be related to the physical situation of the epitaxial growth of XTiO$_3$ a layer on n BaTiO$_3$ layers. It was also studied the effect of the Cd ion volume di...

  12. Experimental animal models of osteonecrosis.

    Science.gov (United States)

    Fan, Meng; Peng, Jiang; Qin, Ling; Lu, Shibi

    2011-08-01

    Osteonecrosis (ON) or avascular necrosis (AVN) is a common bone metabolic disorder, mostly affecting femoral head. Although many biological, biophysical, and surgical methods have been tested to preserve the femoral head with ON, none has been proven fully satisfactory. It lacks consensus on an optimal approach for treatment. This is due, at least in part, to the lack of ability to systematically compare treatment efficacy using an ideal animal model that mimics full-range osteonecrosis of femoral head (ONFH) in humans with high incidence of joint collapse accompanied by reparative reaction adjacent to the necrotic bone in a reproducible and accessible way. A number of preclinical animal ON models have been established for testing potential efficacy of various modalities developed for prevention and treatment of ON before introduction into clinics for potential applications. This paper describes a number of different methods for creating animal experimental ON models. Advantages and disadvantages of such models are also discussed as reference for future research in battle against this important medical condition.

  13. Repercussões respiratórias e hemodinâmicas do pneumoperitônio na lesão do diafragma: estudo experimental Hemodynamic and respiratory changes caused by CO2 laparoscopy in an experimental model of diaphragmatic injury

    Directory of Open Access Journals (Sweden)

    Sílvia Cristine Soldá

    2007-08-01

    Full Text Available OBJETIVO: Analisar as alterações hemodinâmicas e respiratórias secundárias à laparoscopia em modelo experimental de lesão diafragmática. MÉTODOS: Foram utilizados 15 suínos, distribuídos em três grupos com cinco animais cada, assim constituídos: Grupo 1 - Portadores de lesão diafragmática e avaliados sem pneumoperitônio (CLSP; Grupo 2 - Sem lesão diafragmática e avaliados com pneumoperitônio (SLCP; Grupo 3 - Portadores de lesão diafragmática e avaliados com pneumoperitônio (CLCP. Foram avaliadas variáveis gasométricas, hemodinâmicas e respiratórias. RESULTADOS: Houve alterações significantes da pressão média de artéria pulmonar (PAP, pressão de capilar pulmonar (PCP, PAO2, SAO2 e SVO2. CONCLUSÃO: A videolaparoscopia na presença de lesão do diafragma não acarreta alterações do débito cardíaco e pode ser realizada com segurança, desde que a pressão de pneumoperitônio não ultrapasse valores de 15 mmHg.OBJECTIVE: The objective of this study was to analyze the hemodynamic and respiratory changes caused by CO2 laparoscopy in an experimental model of diaphragmatic injury. METHODS: Fifteen animals chosen at random were submitted to diaphragmatic injury by means of CO2 laparoscopy. Evaluation consisted of drawing blood samples to analyze blood gases, as well as the hemodynamic and respiratory variables. RESULTS: Alterations occurred in APA, CPP, PAO2, ASO2, VSO2. CONCLUSION: We concluded that videolaparoscopy with pneumoperitoneum pressure under 15mmHg is a safe procedure in patients with diaphragmatic injuries because this pressure level does not cause hemodynamic changes, such as decrease of the cardiac output. [Rev Assoc Med Bras 2007; 53(4: 294-9

  14. Estudo do Efeito Neuroprotetor do Eugenol em Modelo Experimental da Doença de Huntington

    OpenAIRE

    Nóbrega, Rafaella Farias da

    2013-01-01

    O envelhecimento da população é um dos maiores triunfos da humanidade e também um dos grandes desafios. No entanto, o crescimento da expectativa de vida da população tem levado a um aumento na incidência de doenças características do envelhecimento e tem proporcionado um interesse, cada vez maior, em estudos que visam novas estratégias para a prevenção e cura destas patologias. Várias evidências têm demonstrado que alterações mitocondriais e elevados níveis de estresse oxidativo estão forteme...

  15. O n-butil cianoacrilato na lobectomia pulmonar parcial em felinos: estudo experimental

    Directory of Open Access Journals (Sweden)

    Ishizaki Marcos Makoto

    2005-01-01

    Full Text Available O presente estudo teve como objetivo verificar a viabilidade do n-butil cianoacrilato na pneumostasia e hemostasia em lobectomia pulmonar parcial. Foram utilizadas seis gatas hígidas, adultas, com peso médio de três quilogramas. O procedimento cirúrgico consistiu na realização de toracotomia intercostal com lobectomia pulmonar parcial em que se utilizou adesivo cirúrgico para fechamento do lobo pulmonar. Após 21 dias da cirurgia, os animais foram novamente submetidos à toracotomia para a coleta de fragmento da região onde o adesivo fora aplicado, para análise histopatológica. Foram realizadas radiografias de tórax das pacientes para o acompanhamento pré e pós lobectomia pulmonar parcial e, aos dois, sete, 14 e 21 dias subseqüentes. As alterações radiográficas e clínicas encontradas como pneumotórax residual, aumento na densidade pulmonar, enfisema subcutâneo e apatia foram corrigidas em tempo hábil, não comprometendo os resultados do estudo. A histopatologia evidenciou reação inflamatória com predomínio de células mononucleares, neovascularização, proliferação de tecido conjuntivo e pequenas áreas de enfisema e atelectasia, sem comprometimento clínico significativo. Concluiu-se que o cianoacrilato é capaz de produzir adequada pneumostasia e hemostasia, e poderá ser uma opção para a realização de lobectomia pulmonar parcial em felinos.

  16. Estudo experimental da biocompatibilidade de novo material para implante orbitário

    Directory of Open Access Journals (Sweden)

    Rodrigo Beraldi Kormann

    2013-06-01

    Full Text Available OBJETIVO:Avaliar a biocompatibilidade de material FullCure 720®, que é uma resina, na confecção de implante orbitário. Avaliou-se a resposta clínica dos animais, toxicidade sistêmica e a resposta inflamatória crônica. Os animais foram pesados, exames bioquímicos e resposta inflamatória foram avaliados. Foi efetuada evisceração e colocado implante esférico orbitário. Os animais foram acompanhados durante o período de 60 dias, onde se avaliou o comportamento clínico e sinais locais. Após este período, procedeu-se a eutanásia seguida da enucleação. Foi realizada análise macroscópica e histomorfométrica. Os resultados revelaram comportamento normal dos animais, com ausência de exposição ou extrusão dos implantes, morte de algum animal e ausência de toxicidade sistêmica. Houve formação de uma cápsula fibrosa entre a capa escleral e o implante orbitário, resposta inflamatória considerada normal quando em contato com o tecido do coelho. A resina FullCure 720® utilizada como implante orbitário, mostrou-se biocompatível neste estudo.

  17. Alternativa para ligaduras em cirurgias videoendoscópicas ou convencionais, com emprego de fitas de nylon: um estudo experimental

    Directory of Open Access Journals (Sweden)

    Albino Augusto Sorbello

    Full Text Available Os autores apresentam a proposta de utilização de fitas de nylon (braçadeiras em cirurgias videoendoscópicas ou convencionais. Estas braçadeiras foram idealizadas para amarração de cabos elétricos. Efetuaram estudo experimental em ratos brancos (teste de comportamento biológico e cães (ligaduras vasculares e de intestino com bom resultado técnico e demonstrando escassa reação tecidual na presença deste material. Ficaram confirmadas a exeqüibilidade, a praticidade, a segurança e a economia na utilização das mesmas, sugerindo que possam ser aceitas como um método alternativo na prática cirúrgica.

  18. Fundamental steps in experimental design for animal studies Passos fundamentais em desenhos experimentais de estudos envolvendo animais

    Directory of Open Access Journals (Sweden)

    José Eduardo de Aguilar-Nascimento

    2005-02-01

    Full Text Available Animal studies continue to have a vital role in science development. The aim of this review is to provide to new investigators an overview of the important steps involved in experimental designs and also to suggest some practical information that is commonly associated with this process. Investigators should adhere to the ethical procedure and follow strictly the scientific method. Both the aims and well-formulated hypothesis are essential and practical. In this regard a profound literature search and the aid of an experienced statistician is encouraged. The need of randomization, blinding, and attempting to minimize variation is discussed and recommended. The choosing of good control groups and the employment of pilot studies are useful. Finally, the formulation of new questions to be further responded is expected.Estudos em animais continuam a ser vital para o desenvolvimento da ciência. O objetivo dessa revisão é o de apresentar a novos pesquisadores, uma visão geral dos passos importantes envolvidos no desenho experimental e, ao mesmo tempo, sugerir algumas informações de ordem prática que geralmente estão incluídas no processo da pesquisa. Os pesquisadores devem atentar sempre aos princípios éticos e seguir estritamente o método científico. Hipóteses bem formuladas e objetivas claros são essenciais e práticos. Nesse contexto, uma pesquisa bibliográfica profunda deve ser executada previamente e o pesquisador deve contar, se possível, com o auxilio de um estatístico experiente. A necessidade de randomização, de planejar um estudo cego e de se minimizar a variação são discutidas e enfatizadas. A escolha de bons grupos controles e o emprego de um estudo piloto são recomendados. Finalmente, a formulação de novas questões para serem respondidas por novas pesquisas é esperada.

  19. A contribution to the study of acute schistosomiasis (an experimental trial Contribuição ao estudo da esquistossomose aguda (uma tentativa experimental

    Directory of Open Access Journals (Sweden)

    Zilton A. Andrade

    1987-09-01

    Full Text Available In an attempt to establish an experimental model of acute schistosomiasis, sequential histological changes were investigated in the skin, lung, liver and spleen of mice infected with 30 or 100 cercariae of Schistosoma mansoni according to four sets of experiments: single infection, repeated infections, unisexual infection and infection in mice born from infected mothers. Animals were killed every other day from exposure up to 50 days after infection. Only mild, isolated, focal inflammatory changes were found before the appearance of mature eggs in the liver, even when repeated infections were made. Severe changes of reactive hepatitis and splenitis appeared suddenly when the first mature eggs were deposited, around the 37th to 42nd day after infection. The mature eggs induced lytic and coagulative necrosis of hepatocytes around them which was soon followed by dense infiltration of eosinophils. So, mature egg-induced lesions appeared as the major factors in the pathogenesis of acute schistosomiasis in mice. Mice born from infected mothers were apparently able to rapidly modulate the egg-lesions, forming early fibrotic granulomas. The murine model of acute schistosomiasis appeared adequate for the study of pathology and pathogenesis of acute schistosomiasis.Numa tentativa para se estabelecer um modelo experimental para o estudo da esquistossomose aguda foram estudadas as alterações presentes na pele, pulmões, fígado e baço de comundongos submetidos a infecção com 30 ou 100 cercarias do Schistosoma mansoni e divididos em quatro tipos de experimentos: infecção simples, infecções repetidas, infecção unissexuada e infecção em animais provenientes de mães infectadas. Os animais foram sacrificados em dias alternados a partir do momento da infecção até 50 dias depois. As lesões encontadas na fase pré-postural foram discretas e poucas, mesmo quando os animais foram submetidos a infecções repetidas. As alterações mais súbitas e

  20. Um estudo experimental sobre os afundamentos nas trilhas de rodas de pavimentos delgados com basaltos alterados

    Directory of Open Access Journals (Sweden)

    Washington Peres Núnez

    2010-04-01

    Full Text Available

    Este trabalho apresenta os resultados de um estudo em verdadeira grandeza sobre afundamentos nas trilhas de roda em pavimentos delgados com bases de basaltos alterados. Um simulador linear de tráfego aplicou mais de 267.000 ciclos de carga, variáveis entre 82 e 130 kN, a cinco pistas experimentais construídas na Área de Pesquisas e Testes de Pavimentos, localizada em Porto Alegre. As estruturas ensaiadas continham bases com espessuras de 16, 21 e 32 cm, construídas com basaltos alterados de duas procedências distintas. Um total de 4.148 flechas, medidas periodicamente, forneceram um conjunto de dados consistente para uma análise estatística significativa. A evolução das flechas mostrou depender das características do tráfego e das estruturas dos pavimentos. Considerando os afundamentos nas trilhas de roda como causa da degradação de pavimentos delgados e uma flecha de 25 mm como critério de ruptura, calcularam-se fatores de equivalência de carga, através de uma análise de confiabilidade.

    ABSTRACT

    This paper presents the results of a study of rutting of thin pavements where weathered basalts were used as base layers. A linear traffic simulator applied more than 267,000 axle loads, ranging from 82 to 130 kN, to five full-scale test sections built in a Pavement Testing Facility located in Porto Alegre (Southern Brazil. Two different weathered basalts and three base thicknesses (16 cm; 21 cm and 32 cm were used. A total of 4,148 measurements of rut depth, made at intervals, provided a statistically significant data set. Rutting evolution showed to depend not only on traffic characteristics but also on pavement structure. Considering rutting as major failure cause of thin pavements and a rut depth of 25 mm as terminal criterion, load equivalence factors were calculated, by means of a reliability analysis.

  1. Hipersensibilidade tardia a antígeno de Trypanosoma cruzi: I - estudo experimental em coelhos

    Directory of Open Access Journals (Sweden)

    Antonio R.L. Teixeira

    1995-09-01

    Full Text Available Reações de hipersensibilidade cutânea tardia em coelhos infectados com Trypanosoma cruzi homólogo ou heterólogo, foram obtidas pela injeção de 50µg de proteína do antígeno T12E, derivado de um clone do parasito. A especificidade do teste foi indicada pela ausência de reação em coelhos controles normais que receberam a mesma quantidade de antígeno na pele. A injeção intradérmica do antígeno, em cinco ocasiões, não induziu reação cutânea positiva ou soroconversão dos exames de hemaglutinação e aglutinação, em coelhos controles normais. Por outro lado, coelhos chagásicos submetidos a série de cinco testes cutâneos, com intervalos de uma semana, não exibiram alteração da intensidade das reações de hipersmsibilidade ou dos perfis dos títulos de anticorpos séricos. Os registros eletrocardiográficos também não foram alterados pelos testes cutâneos em coelhos normais e chagásicos. A inocuidade do antígeno T12E foi confirmada em experimentos realizados em 36 coelhos chagásicos e 19 coelhos controles normais. Esse estudo mostra que o teste cutâneo com o antígeno T12E pode ser útil no diagnóstico, além de servir como indicador de morbidade da doença.Delayed-type skin hypersensitivity in rabbits infected with homologous or heterologous T. cruzi has been elicited upon injection of 50µg of protein in the T12E antigen derived from a parasite clone. The specificity of this reaction was indicated by absence of skin reactivity in control rabbits that received same quantity of antigen. Also, the intradermal injection of the antigen in five occasions in control rabbits neither induced seroconversion nor shifted their skin seitsitiveness. On the other hand, chagasic rabbits that underwent a series of five skin testings one week apart, did not alter the intensity of the skin reactivity, and their specific serum antibody titers remained similarly high. Of interest, the ECG patterns remained unchanged after a series

  2. Potencial cicatricial da Bixa orellana L. em feridas cutâneas: estudo em modelo experimental

    Directory of Open Access Journals (Sweden)

    S.O. Capella

    2016-02-01

    Full Text Available O uso de fitoterápicos é uma alternativa de baixo custo e de fácil acesso para o tratamento de feridas cutâneas. Objetivou-se avaliar a ação do extrato oleoso de urucum na cicatrização de feridas cutâneas abertas. Inicialmente, identificaram-se os principais ácidos graxos do óleo de urucum. Foi realizado ensaio citotóxico para determinar as concentrações a serem utilizadas no ensaio in vivo. No experimento, feridas cutâneas em ratos Wistar foram diariamente tratadas com: extrato de urucum 0,1% (U 0,1%, extrato de urucum 0,01% (U 0,01%, vaselina (V e solução fisiológica (SF, por até 21 dias. Aos quatro, sete, 14 e 21 dias, foi avaliada clinicamente a presença de exsudato, crosta e epitelização. Determinaram-se as áreas da lesão, e amostras de pele, fígado e rins foram coletadas para avalição histológica. Aos 21dias, amostras de pele foram coletadas para análise tensiométrica. Clinicamente, todos os grupos de tratamento apresentaram evolução cicatricial fisiológica. Os grupos U 0,1% e U 0,01% apresentaram maior presença de epitelização aos sete dias e maior retração cicatricial aos quatro dias. Na histologia, U 0,1% e U 0,01% apresentaram aos quatro e sete dias maior quantidade de fibrina e inflamação que V e SF, e, nos demais momentos, não houve diferenças entre os grupos. Quanto à fase cicatricial, aos quatro dias todos os grupos encontravam-se na fase inflamatória, aos sete dias U 0,1% e U 0,01% permaneciam na fase inflamatória, diferindo de SF e V, que se caracterizavam na fase proliferativa. Aos 14 dias, os grupos apresentavam-se em transição de fase proliferativa para maturação e, aos 21dias, estavam todos na fase de maturação. Os grupos tratados com urucum expressaram menor resistência à tensão que V e SF. Concluiu-se com este estudo que o extrato oleoso de urucum acelera o processo cicatricial nos primeiros dias, mas proporciona uma cicatriz de baixa qualidade.

  3. Novo modelo de endoprótese traqueal autoexpansível de fabricação nacional: estudo experimental em coelhos A new model of a self-expanding tracheal stent made in Brazil: an experimental study in rabbits

    Directory of Open Access Journals (Sweden)

    Celso Murilo Nálio Matias de Faria

    2012-04-01

    Full Text Available Objetivamos testar um novo modelo de endoprótese traqueal autoexpansível para que esse possa ser futuramente disponibilizado para o uso clínico. As endopróteses de nitinol revestidas de poliuretano foram alocadas no terço médio da traqueia de 25 coelhos da raça Nova Zelândia sob laringoscopia direta. Após um período de observação médio de 26 dias, avaliou-se a migração da prótese, grau de dilatação, incorporação, aderência, formação de tecido de granulação, presença de infiltrado inflamatório, envolvimento parietal e revestimento epitelial. Os resultados demonstraram completa expansibilidade radial, pouca aderência à mucosa traqueal e baixa incorporação tecidual, assim como alta taxas de formação de granulomas e de migração. Esse novo modelo demonstrou ser biocompatível e teve comportamento semelhante ao de outras próteses disponíveis no mercado.We aimed to test a new model of self-expanding tracheal stent so that it might be made available for clinical use. Using direct laryngoscopy, we placed polyurethane-coated, nitinol stents into the middle third of the trachea in 25 New Zealand rabbits. After a mean observation period of 26 days, we evaluated stent migration, degree of expansion, attachment, adherence, formation of granulation tissue, presence of inflammatory infiltrate, parietal involvement, and epithelial lining. The results showed complete radial expansion, little adherence to the tracheal mucosa, and low tissue attachment, as well as high rates of granuloma formation and stent migration. This new model proved to be biocompatible and showed a behavior similar to that of other stents on the market.

  4. Estudo teórico e experimental de paredes esbeltas de alvenaria estrutural

    Directory of Open Access Journals (Sweden)

    Guilherme Aris Parsekian

    Full Text Available Resumo Um dos fatores a serem levados em conta no dimensionamento de elementos comprimidos é sua esbeltez. Até hoje no Brasil utiliza-se o conceito de esbeltez simplificado, no qual o comprimento de flambagem é determinado por uma altura efetiva (hef, e o raio de giração é substituído por um parâmetro chamado espessura efetiva (tef, para o cálculo de fator minorador de resistência. Outras normas de alvenaria estrutural, como as norte-americana, europeia e australiana, trazem também em sua formulação de cálculo da capacidade de carga de uma parede comprimida um fator redutor de resistência. Já a normalização canadense indica que seja feita uma análise mais próxima da realidade, considerando o equilíbrio na configuração deformada da parede (análise P-Delta. Um programa experimental que envolveu 18 ensaios de paredes de blocos cerâmicos e de concreto com elevada esbeltez, obtida com a utilização de blocos de pequena espessura, é aqui relatado. As previsões da capacidade de carga para o caso de blocos de concreto de geometria vazada foram próximas aos resultados dos ensaios. No caso dos blocos cerâmicos utilizados, de geometria complexa, com as paredes dos blocos também vazadas, apenas a aproximação da norma canadense permitiu obter com algum grau de segurança e proximidade os resultados dos ensaios. Paredes mais esbeltas e com blocos de geometrias complexas exigem procedimentos mais refinados para o cálculo, em que o processo P-Delta e a verificação da seção com material não resistente à tração podem ser uma solução.

  5. Enxertos valvares aórticos homólogos: estudo experimental em cães

    Directory of Open Access Journals (Sweden)

    Rui Manoel Sequeira de ALMEIDA

    1998-01-01

    Full Text Available Vinte cães foram divididos em dois grupos de dez, sendo um o grupo doador (Grupo 1 e o outro, o receptor (Grupo 2. Todos os animais do grupo 1 foram submetidos a uma toracotomia mediana e sacrificados, para a retirada do coração e da valva aórtica; os cães do grupo 2 foram submetidos a uma laparotomia mediana para o implante das valvas aórticas homólogas na aorta abdominal infra-renal. O peso médio dos cães do grupo 1 era de 5,5 ± 1,7 kg e o diâmetro médio da aorta descendente de 11,8 ± 1,4 mm. No grupo 2 o peso médio era de 11,9 ± 2,3 kg e o diâmetro da aorta abdominal, de 8,8 ± 1,2 mm. A operação no grupo 2 teve como intercorrência a lesão do conduto linfático, em 4 casos, sendo o tempo médio de isquemia, durante o implante do enxerto homólogo, de 37,6 ± 13,3 min. Os animais foram acompanhados por um período de trinta dias, à exceção de 3. Um cão faleceu no décimo dia de pós-operatório por infarto da artéria mesentérica inferior; um segundo foi sacrificado no décimo quarto dia, por apresentar deiscência parcial da ferida cirúrgica, e o terceiro se evadiu no vigésimo quinto dia de pós-operatório. Dois animais apresentaram deiscência da incisão cirúrgica, levando a uma morbidade de 20%. No trigésimo dia, todos os animais sobreviventes foram submetidos a nova laparotomia, quando foram analisados as aderências da cavidade abdominal e o hematoma em torno do enxerto homólogo, e foram aferidas e registradas as pressões proximal e distal ao enxerto valvar (gradiente médio de 25 mmHg. Após o sacrifício do animal, os enxertos foram explantados para a análise das válvulas que eram normais, à excepção de dois, que apresentavam trombos e retração com fibrose, porém, sem significação clínica. Conclui-se que o modelo é viável para estudos futuros sobre valvas aórticas homólogas.The aim of this research was to develop an experimental model, with dogs, to study homologous aortic valve grafts. A

  6. New model systems for experimental evolution.

    Science.gov (United States)

    Collins, Sinéad

    2013-07-01

    Microbial experimental evolution uses a few well-characterized model systems to answer fundamental questions about how evolution works. This special section highlights novel model systems for experimental evolution, with a focus on marine model systems that can be used to understand evolutionary responses to global change in the oceans. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  7. Cardioplegia sangüínea normotérmica intermitente anterógrada: estudo experimental em coelhos

    Directory of Open Access Journals (Sweden)

    Alfredo José RODRIGUES

    1997-07-01

    Full Text Available Objetivos: Investigar a proteção miocárdica proporcionada pela infusão anterógrada intermitente, durante 60 minutos, de solução cardioplégica sangüínea a 37°C, em corações normais isolados de coelhos. Material e Métodos: Foram estudados 32 coelhos da raça Nova Zelândia, divididos em grupos, Experimental e Controle. O estudo foi realizado em 2 fases: Fase I: Estudo metabólico após isquemia sem reperfusão, Fase II: Estudo metabólico e funcional após reperfusão. A reperfusão foi realizada utilizando-se um sistema de perfusão parabiótica. Determinou-se o glicogênio miocárdico e a respiração mitocondrial no miocárdio ventricular, imediatamente ao final do período de infusão intermitente da solução cardioplégica (Fase I e após reperfusão sangüínea (Fase II, durante a qual analisou-se, também, a função ventricular esquerda (dP/dtmax. Resultados: Detectou-se queda significativa nos níveis de glicogênio miocárdico de 58% em relação ao controle, ao final do período de infusão (Fase I. Na fase com reperfusão (Fase II, as diferenças no glicogênio miocárdico entre o grupo experimental e seu controle não foram significativas. A análise da respiração mitocondrial não mostrou diferenças significativas entre os grupos experimentais e seus controles, quer seja nas fases com ou sem reperfusão. Os valores da dP/dtmax, na Fase II foram de 903,39 ± 113,46 mmHg/s e 1.043 ± 256,94 mmHg/s, para o grupo experimental e controle, respectivamente. A diferença entre os valores não foi significativa. Conclusões: A infusão anterógrada intermitente a cada 20 minutos, durante 60 minutos, de solução cardioplégica sangüínea a 37°C, mostrou-se um método eficaz de proteção miocárdica em corações normais de coelhos.Purpose: To study the degree of myocardial protection provided by intermittent infusion of normothermic blood cardioplegia during 60 minutes in normal rabbit hearts. Methods: The study was

  8. Developing Phenomena Models from Experimental Data

    DEFF Research Database (Denmark)

    Kristensen, Niels Rode; Madsen, Henrik; Jørgensen, Sten Bay

    2003-01-01

    unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance......A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

  9. Developing Phenomena Models from Experimental Data

    DEFF Research Database (Denmark)

    unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance......A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

  10. Model refinement for offshore platforms: Experimental study

    Science.gov (United States)

    Zhang, Min; Chen, Zongli; Wu, Yanjian

    2017-08-01

    Offshore jacket platforms are widely used in offshore oil and gas exploitation. Finite element models of such structures need to have many degrees of freedom (DOFs) to represent the geometrical detail of complex structures, thereby leading to incompatibility in the number of DOFs of experimental models. To bring them both to the same order while ensuring that the essential eigen- properties of the refined model match those of experimental models, an extended model refinement procedure is presented in this paper. Vibration testing of an offshore jacket platform model is performed to validate the applicability of the proposed approach. A full-order finite element model of the platform is established and then tuned to meet the measured modal properties identified from the acceleration signals. Both model reduction and modal expansion methods are investigated, as well as various scenarios of sensor arrangements. Upon completion of the refinement, the updated jacket platform model matches the natural frequencies of the measured model well.

  11. Experimental models of demyelination and remyelination.

    Science.gov (United States)

    Torre-Fuentes, L; Moreno-Jiménez, L; Pytel, V; Matías-Guiu, J A; Gómez-Pinedo, U; Matías-Guiu, J

    2017-08-29

    Experimental animal models constitute a useful tool to deepen our knowledge of central nervous system disorders. In the case of multiple sclerosis, however, there is no such specific model able to provide an overview of the disease; multiple models covering the different pathophysiological features of the disease are therefore necessary. We reviewed the different in vitro and in vivo experimental models used in multiple sclerosis research. Concerning in vitro models, we analysed cell cultures and slice models. As for in vivo models, we examined such models of autoimmunity and inflammation as experimental allergic encephalitis in different animals and virus-induced demyelinating diseases. Furthermore, we analysed models of demyelination and remyelination, including chemical lesions caused by cuprizone, lysolecithin, and ethidium bromide; zebrafish; and transgenic models. Experimental models provide a deeper understanding of the different pathogenic mechanisms involved in multiple sclerosis. Choosing one model or another depends on the specific aims of the study. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. CONGESTIVE HEART FAILURE: EXPERIMENTAL MODEL

    Directory of Open Access Journals (Sweden)

    Antonio Francesco Corno

    2013-10-01

    Full Text Available INTRODUCTION.Surgically induced, combined volume and pressure overload has been used in rabbits to create a simplified and reproducible model of acute left ventricular (LV failure.MATERIALS AND METHODS.New Zealand white male rabbits (n=24, mean weight 3.1±0.2kg were randomly assigned to either the Control group (n=10 or to the Heart Failure group (HF, n=14. Animals in the Control group underwent sham procedures. Animals in the HF group underwent procedures to induce LV volume overload by inducing severe aortic valve regurgitation with aortic cusp disruption and pressure overload using an occlusive silver clip positioned around the pre-renal abdominal aorta.RESULTS.Following Procedure-1 (volume overload echocardiography confirmed severe aortic regurgitation in all animals in the HF group, with increased mean pulse pressure difference from 18±3mmHg to 38±3mmHg (P

  13. Estudo da transmigração bacteriana na apendicite experimental em coelhos A study about bacterial transmigration in experimental Appendicitis in rabbits

    Directory of Open Access Journals (Sweden)

    ECF RAMOS

    2000-01-01

    Full Text Available Introdução: A queda extrínseca dos mecanismos de defesa de um hospedeiro é vista classicamente como uma infecção, que resulta na aquisição de um tecido normal, de um novo microorganismo, cuja virulência é fundamental para a sua patogenia.Na década de 50, estudos comprovaram que bactérias e endotoxinas podem ultrapassar a barreira intestinal e atingir a circulação, demonstrando ainda, que a flora intestinal representa uma importante fonte para o desenvolvimento da infecção sistêmica. Objetivo: o presente estudo visa avaliar a ocorrência de transmigração bacteriana em apendicite experimental induzida em coelhos, mediante a oclusão completa do apêndice vermiforme. Métodos: foram utilizados 24 coelhos brancos, da linhagem Nova Zelândia, com peso corporal variando de 2500 a 3000 gramas, sendo então divididos em 2 grupos. Os animais do Grupo I foram submetidos a laparotomia mediana e retirada de fragmentos do baço, rim esquerdo, pulmão direito, linfonodo abdominal, conteúdo da luz do apêndice vermiforme e sangue da veia porta para cultura. Os animais do Grupo II foram submetidos a laparotomia mediana e oclusão completa do apêndice vermiforme para a indução de apendicite e, após 24 horas, realizada a coleta do material nos moldes do Grupo I. Resultados: No Grupo controle (Grupo I, não se observou o crescimento de bactérias nas amostras analisadas. No Grupo experimento (Grupo II, observou-se o crescimento de Escherichia coli em todos os animais. Conclusão: Ocorreu transmigração bacteriana após 24 horas de observação em coelhos com apendicite experimental.The present study aims to evaluate the occurrence of the bacterial transmigration in induced ezxperimental appendicitis in rabbitis through complete oclusion of the vermiform appendix. 24 New Zealand white rabbits with a body weight ranging from 2500 to 3000 grams were used. They were divided into 2 groups. The animals from group I were submitted to a median

  14. Improving the physiological realism of experimental models.

    Science.gov (United States)

    Vinnakota, Kalyan C; Cha, Chae Y; Rorsman, Patrik; Balaban, Robert S; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A; Jeneson, Jeroen A L

    2016-04-06

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these models rely on the analysis and integration of experimental data. As such, the success of VPH depends on the availability of physiologically realistic experimental models (E-Models) of human organ function that can be parametrized to test the numerical models. Here, the current state of suitable E-models, ranging from in vitro non-human cell organelles to in vivo human organ systems, is discussed. Specifically, challenges and recent progress in improving the physiological realism of E-models that may benefit the VPH project are highlighted and discussed using examples from the field of research on cardiovascular disease, musculoskeletal disorders, diabetes and Parkinson's disease.

  15. Understanding Leadership: An Experimental-Experiential Model

    Science.gov (United States)

    Hole, George T.

    2014-01-01

    Books about leadership are dangerous to readers who fantasize about being leaders or apply leadership ideas as if they were proven formulas. As an antidote, I offer an experimental framework in which any leadership-management model can be tested to gain experiential understanding of the model. As a result one can gain reality-based insights about…

  16. Modeling of Experimental Adsorption Isotherm Data

    Directory of Open Access Journals (Sweden)

    Xunjun Chen

    2015-01-01

    Full Text Available Adsorption is considered to be one of the most effective technologies widely used in global environmental protection areas. Modeling of experimental adsorption isotherm data is an essential way for predicting the mechanisms of adsorption, which will lead to an improvement in the area of adsorption science. In this paper, we employed three isotherm models, namely: Langmuir, Freundlich, and Dubinin-Radushkevich to correlate four sets of experimental adsorption isotherm data, which were obtained by batch tests in lab. The linearized and non-linearized isotherm models were compared and discussed. In order to determine the best fit isotherm model, the correlation coefficient (r2 and standard errors (S.E. for each parameter were used to evaluate the data. The modeling results showed that non-linear Langmuir model could fit the data better than others, with relatively higher r2 values and smaller S.E. The linear Langmuir model had the highest value of r2, however, the maximum adsorption capacities estimated from linear Langmuir model were deviated from the experimental data.

  17. Experimental Concepts for Testing Seismic Hazard Models

    Science.gov (United States)

    Marzocchi, W.; Jordan, T. H.

    2015-12-01

    Seismic hazard analysis is the primary interface through which useful information about earthquake rupture and wave propagation is delivered to society. To account for the randomness (aleatory variability) and limited knowledge (epistemic uncertainty) of these natural processes, seismologists must formulate and test hazard models using the concepts of probability. In this presentation, we will address the scientific objections that have been raised over the years against probabilistic seismic hazard analysis (PSHA). Owing to the paucity of observations, we must rely on expert opinion to quantify the epistemic uncertainties of PSHA models (e.g., in the weighting of individual models from logic-tree ensembles of plausible models). The main theoretical issue is a frequentist critique: subjectivity is immeasurable; ergo, PSHA models cannot be objectively tested against data; ergo, they are fundamentally unscientific. We have argued (PNAS, 111, 11973-11978) that the Bayesian subjectivity required for casting epistemic uncertainties can be bridged with the frequentist objectivity needed for pure significance testing through "experimental concepts." An experimental concept specifies collections of data, observed and not yet observed, that are judged to be exchangeable (i.e., with a joint distribution independent of the data ordering) when conditioned on a set of explanatory variables. We illustrate, through concrete examples, experimental concepts useful in the testing of PSHA models for ontological errors in the presence of aleatory variability and epistemic uncertainty. In particular, we describe experimental concepts that lead to exchangeable binary sequences that are statistically independent but not identically distributed, showing how the Bayesian concept of exchangeability generalizes the frequentist concept of experimental repeatability. We also address the issue of testing PSHA models using spatially correlated data.

  18. Experimental deep brain stimulation in animal models.

    Science.gov (United States)

    Tan, Sonny Kh; Vlamings, Rinske; Lim, Leewei; Sesia, Thibault; Janssen, Marcus Lf; Steinbusch, Harry Wm; Visser-Vandewalle, Veerle; Temel, Yasin

    2010-10-01

    DEEP BRAIN STIMULATION (DBS) as a therapy in neurological and psychiatric disorders is widely applied in the field of functional and stereotactic neurosurgery. In this respect, experimental DBS in animal models is performed to evaluate new indications and new technology. In this article, we review our experience with the concept of experimental DBS, including its development and validation. An electrode construction was developed using clinical principles to perform DBS unilaterally or bilaterally in freely moving rats. The stimulation parameters were adjusted for the rat using current density calculations. We performed validation studies in 2 animal models: a rat model of Parkinson's disease (bilateral 6-hydroxydopamine infusion in the striatum) and a rat model of Huntington's disease (transgenic rats). The effects of DBS were evaluated in different behavioral tasks measuring motor and cognitive functions. The electrode construction developed allows experimental DBS to be performed in freely moving rats. With the current setup, electrodes are placed in the target in 70% to 95% of the cases. Using a rat model, we showed that bilateral DBS of the subthalamic nucleus improves parkinsonian motor disability, but can induce behavioral side effects, similar to the clinical situation. In addition, we showed that DBS of the globus pallidus can improve motor and cognitive symptoms in a rat model of Huntington's disease. Nevertheless, during the process of the development and validation of experimental DBS, we encountered specific problems. These are discussed in detail. Experimental DBS in freely moving animals is an adequate tool to explore new indications for DBS and to refine DBS technology.

  19. Prospects of experimentally reachable beyond Standard Model ...

    Indian Academy of Sciences (India)

    2016-01-06

    Jan 6, 2016 ... Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 2. Prospects of experimentally reachable beyond Standard Model physics in inverse see-saw motivated SO(10) GUT. Ram Lal Awasthi. Special: Supersymmetric Unified Theories and Higgs Physics Volume 86 Issue 2 February 2016 pp 223- ...

  20. Prospects of experimentally reachable beyond Standard Model ...

    Indian Academy of Sciences (India)

    2016-01-06

    Jan 6, 2016 ... also fit perfectly in the model framework. Despite the fact that SM has unravelled the gauge origin of fundamental forces and the structure of Universe while successfully confronting numerous experimental tests, it has various limitations. For a good summary on its excellencies and compulsions see [1], and.

  1. Linfadenocromatografia perigástrica com carbono ativado (CH40: estudo experimental Perigastric lymphadenochromatography with activated carbon (CH40: experimental study

    Directory of Open Access Journals (Sweden)

    Minao Okawa

    2007-09-01

    Full Text Available RACIONAL: Procedimento cirúrgico bem instituído e planejado constitui ainda a única terapêutica efetiva para o câncer gástrico. Entretanto, os resultados de cura não têm melhorado significativamente nas últimas décadas, principalmente no ocidente. O principal benefício de introdução endoscópica de corantes na submucosa gástrica está na facilitação de linfadenectomias regradas, podendo facilitar a localização acurada dos linfonodos. Além disso, a linfadenocromatografia possibilita futuras pesquisas para a detecção do linfonodo sentinela e sua aplicabilidade racional e seletiva na indicação precisa da linfadenectomia, principalmente dos grupos de linfonodos de ressecção mais trabalhosa e com maiores possibilidades de complicações. A linfadenocromatografia com carbono ativado (CH40 foi analisada neste estudo experimental (fase 1. OBJETIVOS: Testar a efetividade e inocuidade da linfadenocromatografia com CH40, em três espécies animais diferentes. MÉTODOS: Como preconizado pela Associação Brasileira de Pesquisas Clínicas (Resoluções nº 196/96 e 251/97, CNS/MS, foram utilizados três espécies diferentes de animais: 3 cães, 10 coelhos e 20 ratos. Em todos os cães, a introdução de CH40 na camada submucosa de estômago foi realizada através da endoscopia gástrica e utilizando, cateter de polietileno agulhado, usualmente empregado na esclerose de varizes esofageanas. O período de observação variou de 43 a 125 dias, quando o procedimento cirúrgico foi realizado. Em todos os coelhos e ratos a introdução de CH40 foi realizada através de agulha hipodérmica e seringa insulínica, na região subcutânea inguinal. O período de observação foi de 102 a 105 dias e 110 a 122 dias, respectivamente. RESULTADOS: Nos períodos de observação, desde a injeção até a eutanásia, não se detectou em nenhum animal efeito colateral ou óbito. Nos cães, linfonodos perigástricos foram corados pelo CH40. Em todos os

  2. Electrochemical desalination of bricks - Experimental and modeling

    DEFF Research Database (Denmark)

    Skibsted, Gry; Ottosen, Lisbeth M.; Jensen, Pernille Erland

    2015-01-01

    Chlorides, nitrates and sulfates play an important role in the salt-decay of porous materials in buildings and monuments. Electrochemical desalination is a technology able to remove salts from such porous materials in order to stop or prevent the decay. In this paper, experimental and numerical......-contaminated bricks with respect to the monovalent ions is discussed. Comparison between the experimental and the simulation results showed that the proposed numerical model is able to predict electrochemical desalination treatments with remarkable accuracy, and it can be used as a predictive tool...

  3. The rabbit as an animal model for experimental surgery O coelho como modelo animal para cirurgia experimental

    Directory of Open Access Journals (Sweden)

    Mônica Diuana Calasans-Maia

    2009-08-01

    Full Text Available The white New Zealand rabbit (Oryctolagus cuniculus is frequently used as a model for in vivo studies. However, information on precautions when using this animal as an experimental model is limited. This review of the literature covers the gamut from the selection of the animal model all the way to its death, and describes procedures for transporting, raising, breeding, housing, administering anesthesia and handling so as to rationalize the utilization of this species while exploiting its unique characteristics. Based upon the literature and our own experience with white New Zealand rabbits, we conclude that the rabbit is an adequate model for experimental surgery.O coelho branco da Nova Zelândia (Oryctolagus cuniculus é freqüentemente utilizado como modelo em estudos in vivo. Contudo, as informações referentes aos cuidados no emprego deste animal como modelo experimental são limitadas. Esta revisão da literatura pretende rever a literatura desde a seleção do modelo animal até a sua morte, enfatizando, os procedimentos para transporte, criação, reprodução, comportamento, acomodação, anestesia e manejo dos animais, de forma a racionalizar a utilização desses animais reconhecendo as características próprias dessa espécie. Conclui-se que o coelho constitui um modelo adequado e viável para cirurgia experimental.

  4. Study of morbidity in orthotopic small intestine transplantation with Wistar rats: experimental study Estudo da morbidade em transplante ortotópico de intestino delgado em ratos Wistar: estudo experimental

    Directory of Open Access Journals (Sweden)

    André Dong Won LEE

    2002-03-01

    total surgical time.Racional- O transplante de intestino delgado é procedimento cirúrgico em estudo visando sua aplicação no tratamento dos pacientes portadores da síndrome do intestino curto, com vistas à reabilitação da dieta oral. Objetivo - Definir a morbidade e mortalidade do transplante intestinal em animal de pequeno porte com emprego da microcirurgia. Foi estudado a morbidade e a mortalidade intra e pós-operatória no alotransplante intestinal ortotópico em ratos Wistar. Material e Método - Os animais foram divididos em três grupos: grupo A (37 animais doadores, grupo B (37 animais receptores e C grupo (10 animais controle, sendo que o grupo B foi subdividido em três subgrupos conforme o tempo de sobrevivência. Os animais que faleceram durante o ato operatório ou de causa relacionada diretamente à intervenção cirúrgica constituíram o subgrupo. Os animais que faleceram entre o quarto e 29º dia de pós-operatório constituíram o subgrupo T2 e os que sobreviveram após 30 dias constituíram o subgrupo T3. Os animais transplantados foram avaliados quanto à técnica cirúrgica empregada (anastomoses vascular e intestinal, qualidade do enxerto, tempo cirúrgico e parâmetros clínicos. Realizou-se autopsia dos animais que tiveram óbito até o 29º dia de pós-operatório, os demais foram sacrificados após 30 dias. Resultados - Houve alto índice de complicação de natureza cirúrgica; ocorreu 54% de mortalidade precoce, isto é, até o 3º dia de pós-operatório, sendo a anastomose vascular a principal causa de óbito. O tempo cirúrgico foi avaliado num grupo restrito e homogêneo, mostrando forte valor prognóstico quanto ao sucesso do transplante. Os parâmetros clínicos: perda de peso, redução da ingesta, redução da atividade motora e diarréia tiveram correlação direta quanto à rejeição aguda. Conclusão - O transplante intestinal experimental apresenta expressiva morbimortalidade relacionando-as a complicações cir

  5. Experimental Animal Models in Periodontology: A Review

    Science.gov (United States)

    Struillou, Xavier; Boutigny, Hervé; Soueidan, Assem; Layrolle, Pierre

    2010-01-01

    In periodontal research, animal studies are complementary to in vitro experiments prior to testing new treatments. Animal models should make possible the validation of hypotheses and prove the safety and efficacy of new regenerating approaches using biomaterials, growth factors or stem cells. A review of the literature was carried out by using electronic databases (PubMed, ISI Web of Science). Numerous animal models in different species such as rats, hamsters, rabbits, ferrets, canines and primates have been used for modeling human periodontal diseases and treatments. However, both the anatomy and physiopathology of animals are different from those of humans, making difficult the evaluation of new therapies. Experimental models have been developed in order to reproduce major periodontal diseases (gingivitis, periodontitis), their pathogenesis and to investigate new surgical techniques. The aim of this review is to define the most pertinent animal models for periodontal research depending on the hypothesis and expected results. PMID:20556202

  6. Os Impactos das Reclamações On-line na Lealdade dos Consumidores: um Estudo Experimental

    Directory of Open Access Journals (Sweden)

    Tatiane Nunes Viana de Almeida

    2012-09-01

    Full Text Available In a constant changing environment characterized by highly informed consumers, the search for long-term relationships through customer loyalty is the goal of many companies. However, studies suggest this loyalty may be affected by negative comments available on the internet. Thus, the aim of this study is to examine if the complaints available in the online environment impact loyalty to a cell phone brand. The research method was experimental, considering the antecedents of loyalty found in the revised NCSB model (Norwegian Customer Satisfaction Barometer. The approach was quantitative, using methods including descriptive statistics, factor analysis, multiple linear regression and non-parametric Wilcoxon test to analyze the data. All five propositions were confirmed. The results showed that complaints available the web may negatively impact consumer perception as it concerns loyalty, as well as its antecedents. These substantiations represent a warning, so that companies can be more attentive to content available on the internet, especially any related to complaints.

  7. Experimental superficial candidiasis on tissue models.

    Science.gov (United States)

    Jayatilake, J A M S; Samaranayake, L P

    2010-07-01

    Candida species are common pathogens causing superficial mycoses primarily affecting the mucosa and the skin in humans. Crucial steps during pathogenesis of superficial candidiasis comprise fungal adhesion, colonisation and subsequent penetration of the respective tissues. Exploring these pathological events and perhaps fungal and tissue responses towards drug treatment is imperative in the management of this infection. Unfortunately, pathological biopsies of superficial candidiasis do not exhibit the early changes in the host-pathogen interaction as the tissues are already invaded by the fungi. In vivo experimental assessments of pathological processes of superficial candidiasis are also limited because of the difficulties in providing reproducible and comparable conditions in the host environment. Conversely, in vitro models have helped studying fungal-host interactions under more defined and controlled conditions. Some common in vitro models used to simulate superficial candidiasis are chick chorioallantoic membrane, mucosal explants and single layer or multiple layer cell cultures. Interestingly, these experimental approaches share advantages as well as disadvantages when compared with in vivo conditions. Hence, this review intends to discuss about the experimental superficial candidiasis produced in various tissue models and their advantages as well as disadvantages with a particular reference to further improvement of validity and reliability of such experiments.

  8. Seclazone Reactor Modeling And Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Osinga, T. [ETH-Zuerich (Switzerland); Olalde, G. [CNRS Odeillo (France); Steinfeld, A. [PSI and ETHZ (Switzerland)

    2005-03-01

    A numerical model is formulated for the SOLZINC solar chemical reactor for the production of Zn by carbothermal reduction of ZnO. The model involves solving, by the finite-volume technique, a 1D unsteady state energy equation that couples heat transfer to the chemical kinetics for a shrinking packed bed exposed to thermal radiation. Validation is accomplished by comparison with experimentally measured temperature profiles and Zn production rates as a function of time, obtained for a 5-kW solar reactor tested at PSI's solar furnace. (author)

  9. Beyond the standard model, experimental summary

    CERN Document Server

    McPherson, R A

    2003-01-01

    An overview of experimental results in searches for physics beyond the Standard Model is presented. It is impossible to cover all topics in this field, so a set of examples is used to highlight the scope and breadth of the results. Selected topics include searches for compositeness, flavour changing neutral currents, SUSY, exotic Higgs particles, low scale gravity in extra dimensions, and non commutative geometry. Current results are presented from the LEP, Tevatron Run I, and HERA I experiments. No convincing evidence for physics beyond the Standard Model has been observed. Prospects for ongoing and upcoming experiments are discussed. (40 refs).

  10. Experimental in Vivo Models of Candidiasis

    Directory of Open Access Journals (Sweden)

    Esther Segal

    2018-02-01

    Full Text Available Candidiasis is a multifaceted fungal disease including mucosal-cutaneous, visceral, and disseminated infections caused by yeast species of the genus Candida. Candida infections are among the most common human mycoses. Candida species are the third to fourth most common isolates from bloodstream infections in neutropenic or immunocompromised hospitalized patients. The mucosal-cutaneous forms—particularly vaginal infections—have a high prevalence. Vaginitis caused by Candida species is the second most common vaginal infection. Hence, candidiasis is a major subject for research, including experimental in vivo models to study pathogenesis, prevention, or therapy of the disease. The following review article will focus on various experimental in vivo models in different laboratory animals, such as mammals (mice, rats, rabbits, the fruit fly–Drosophila melanogaster, the larvae of the moth Galleria mellonella, or the free-living nematode Caenorhabditis elegans. The review will describe the induction of the different clinical forms of candidiasis in the various models and the validity of such models in mimicking the human clinical situations. The use of such models for the assessment of antifungal drugs, evaluation of potential vaccines to protect before candidiasis, exploration of Candida virulence factors, and comparison of pathogenicity of different Candida species will be included in the review. All of the above will be reported as based on published studies of numerous investigators as well as on the research of the author and his group.

  11. Endometriose: modelo experimental em ratas Endometriosis: experimental model in rats

    Directory of Open Access Journals (Sweden)

    Eduardo Schor

    1999-06-01

    Full Text Available Objetivo: divulgar a metodologia da indução de endometriose experimental em animais de laboratório. Método: utilizamos ratas albinas, virgens, adultas de aproximadamente três meses de idade, que foram inicialmente anestesiadas pelo éter etílico. Aberta a cavidade abdominal, identificamos os cornos uterinos e retiramos um fragmento de aproximadamente 4 cm do corno uterino direito. Esse fragmento foi mergulhado em solução fisiológica e sob lupa estereoscópica foi separado o endométrio do miométrio e feitos retângulos de aproximadamente 4 por 5 mm. Esses foram fixados por meio de fio de sutura, sobre vasos sangüíneos visíveis a olho nu, na parede lateral do abdômen, tomando-se sempre o cuidado de manter a porção do endométrio livre voltada para a luz da cavidade abdominal. Após 21 dias os animais foram novamente operados para verificarmos o tamanho dos implantes e para retirada do endométrio ectópico para análise histológica. Resultados: macroscopicamente observamos crescimento significativo dos implantes endometriais. Ao exame microscópico pudemos observar a presença de epitélio glandular e estroma semelhantes ao do endométrio tópico. Conclusões: o modelo utilizado reproduz a doença, em ratas, sendo método auxiliar de valia para estudar esta afecção, principalmente a ação de medicamentos sobre esses implantes.Purpose: to demonstrate the experimental endometriosis induction in animals. Method: we used adult female Wistar rats weighing 200 - 250 g anesthetized with ethyl ether to open the abdominal cavity. After identifying the uterine horns, we removed an approximately 4 cm fragment from the right uterine horn. This fragment was placed in physiological saline and, with the aid of a stereoscopic magnifying glass, the endometrium was separated from the myometrium and cut into rectangles of approximately 4 x 5 mm. These rectangles were fastened to the lateral abdominal wall near great blood vessels, taking care

  12. Experimental animal modelling for TB vaccine development

    Directory of Open Access Journals (Sweden)

    Pere-Joan Cardona

    2017-03-01

    Full Text Available Research for a novel vaccine to prevent tuberculosis is an urgent medical need. The current vaccine, BCG, has demonstrated a non-homogenous efficacy in humans, but still is the gold standard to be improved upon. In general, the main indicator for testing the potency of new candidates in animal models is the reduction of the bacillary load in the lungs at the acute phase of the infection. Usually, this reduction is similar to that induced by BCG, although in some cases a weak but significant improvement can be detected, but none of candidates are able to prevent establishment of infection. The main characteristics of several laboratory animals are reviewed, reflecting that none are able to simulate the whole characteristics of human tuberculosis. As, so far, no surrogate of protection has been found, it is important to test new candidates in several models in order to generate convincing evidence of efficacy that might be better than that of BCG in humans. It is also important to investigate the use of “in silico” and “ex vivo” models to better understand experimental data and also to try to replace, or at least reduce and refine experimental models in animals.

  13. Nonlinear hierarchical modeling of experimental infection data.

    Science.gov (United States)

    Singleton, Michael D; Breheny, Patrick J

    2016-08-01

    In this paper, we propose a nonlinear hierarchical model (NLHM) for analyzing longitudinal experimental infection (EI) data. The NLHM offers several improvements over commonly used alternatives such as repeated measures analysis of variance (RM-ANOVA) and the linear mixed model (LMM). It enables comparison of relevant biological properties of the course of infection including peak intensity, duration and time to peak, rather than simply comparing mean responses at each observation time. We illustrate the practical benefits of this model and the insights it yields using data from experimental infection studies on equine arteritis virus. Finally, we demonstrate via simulation studies that the NLHM substantially reduces bias and improves the power to detect differences in relevant features of the infection response between two populations. For example, to detect a 20% difference in response duration between two groups (n=15) in which the peak time and peak intensity were identical, the RM-ANOVA test had a power of just 11%, and LMM a power of just 12%. By comparison, the nonlinear model we propose had a power of 58% in the same scenario, while controlling the Type I error rate better than the other two methods. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Models for Experimental High Density Housing

    Science.gov (United States)

    Bradecki, Tomasz; Swoboda, Julia; Nowak, Katarzyna; Dziechciarz, Klaudia

    2017-10-01

    The article presents the effects of research on models of high density housing. The authors present urban projects for experimental high density housing estates. The design was based on research performed on 38 examples of similar housing in Poland that have been built after 2003. Some of the case studies show extreme density and that inspired the researchers to test individual virtual solutions that would answer the question: How far can we push the limits? The experimental housing projects show strengths and weaknesses of design driven only by such indexes as FAR (floor attenuation ratio - housing density) and DPH (dwellings per hectare). Although such projects are implemented, the authors believe that there are reasons for limits since high index values may be in contradiction to the optimum character of housing environment. Virtual models on virtual plots presented by the authors were oriented toward maximising the DPH index and DAI (dwellings area index) which is very often the main driver for developers. The authors also raise the question of sustainability of such solutions. The research was carried out in the URBAN model research group (Gliwice, Poland) that consists of academic researchers and architecture students. The models reflect architectural and urban regulations that are valid in Poland. Conclusions might be helpful for urban planners, urban designers, developers, architects and architecture students.

  15. Estudo experimental com heteroenxertos valvares descelularizados: a prótese do futuro Experimental study with deccelularized porcine heterografts: the prosthesis of the future

    Directory of Open Access Journals (Sweden)

    Francisco Diniz Affonso Da Costa

    2004-03-01

    Full Text Available OBJETIVO: Avaliar, comparativamente, o comportamento de homoenxertos valvares criopreservados e de heteroenxertos descelularizados implantados na via de saída do ventrículo direito de carneiros jovens, assim como relatar a experiência clínica inicial com homoenxertos descelularizados em pacientes submetidos à operação de Ross. MÉTODO: No grupo A, foram implantados quatro homoenxertos pulmonares criopreservados e no Grupo B, quatro heteroenxertos porcinos valvares descelularizados com ácido deoxicólico. Em cada grupo, dois animais foram sacrificados no 3º mês e dois no 5º mês de pós-operatório. As peças foram avaliadas macroscopicamente e por radiografias, além de exame microscópico com colorações HE, Tricrômico de Mallory e Sirius Red. A experiência clínica com quatro pacientes submetidos à operação de Ross com emprego de homoenxertos valvares descelularizados é relatada. RESULTADOS: Todos os animais sobreviveram. Os ecocardiogramas demonstraram boa função valvar nos dois grupos. Embora as cúspides valvares em ambos os grupos tivessem aspecto macroscópico normal, a mensuração de cálcio e o estudo radiológico demonstraram início de calcificação focal nos homoenxertos criopreservados, mas não nos heteroenxertos descelularizados. Esses achados foram confirmados por exames microscópicos. Os homoenxertos criopreservados demonstraram perda de sua celularidade, enquanto que os heteroenxertos descelularizados demonstraram repopulação progressiva da matriz colágena com fibroblastos, assim como reendotelização. Os quatro pacientes operados tiveram evolução pós-operatória imediata satisfatória, com função normal dos homoenxertos. CONCLUSÕES: Heteroenxertos valvares descelularizados foram progressivamente repopulados por células autógenas e exibiram mínima tendência à calcificação no modelo estudado. Esses resultados sugerem que homoenxertos descelularizados possam ter alguma capacidade

  16. Modeling of Experimental Atherosclerotic Plaque Delamination.

    Science.gov (United States)

    Leng, Xiaochang; Chen, Xin; Deng, Xiaomin; Sutton, Michael A; Lessner, Susan M

    2015-12-01

    A cohesive zone model (CZM) approach is applied to simulate atherosclerotic plaque delamination experiments in mouse abdominal aorta specimens. A three-dimensional finite element model is developed for the experiments. The aortic wall is treated as a fiber-reinforced, highly deformable, incompressible material, and the Holzapfel-Gasser-Ogden (HGO) model is adopted for the aortic bulk material behavior. Cohesive elements are placed along the plaque-media interface along which delamination occurs. The 3D specimen geometry is created based on images from the experiments and certain simplifying approximations. A set of HGO and CZM parameter values is determined based on values suggested in the literature and through matching simulation predictions of the load vs. load-point displacement curve with experimental measurements for one loading-delamination-unloading cycle. Using this set of parameter values, simulation predictions for four other loading-delamination-unloading cycles are obtained, which show good agreement with experimental measurements. The findings of the current study demonstrate the applicability of the CZM approach in arterial tissue failure simulations.

  17. Superficial tension: experimental model with simple materials

    Directory of Open Access Journals (Sweden)

    Tintori Ferreira, María Alejandra

    2012-09-01

    Full Text Available In this work appears a didactic offer based on an experimental activity using materials of very low cost, orientated to achieving that the student understand and interpret the phenomenon of superficial tension together with the importance of the modeling in sciences. It has as principal aim of education bring the student over to the mechanics of the static fluids and the intermolecular forces, combining scientific contents with questions near to the student what provides an additional motivation to the reflection of the scientific investigation.

  18. Análise experimental do comportamento e sociedade: um novo foco de estudo Experimental analysis of behavior and society: a new field of investigation

    Directory of Open Access Journals (Sweden)

    João Claudio Todorov

    2004-01-01

    Full Text Available O estudo do comportamento em sociedades foi relegado por quase 50 anos, apesar das reiteradas propostas de Skinner considerando sua importância. No ano de 1980, Sigrid Glenn criou o conceito de metacontingência que contribui como uma importante ferramenta para a descrição e análise do comportamento social. Neste artigo são apresentados alguns estudos envolvendo metacontingências e discute-se o papel do analista do comportamento no desenvolvimento de temas que abordam questões sociais, incluindo análise e modificação de práticas culturais.Although there are many citations where Skinner writes about the importance of the study of cultural practices in behavior analysis, these studies were forgotten for almost fifty years. Working in this plan Sigrid Glenn has created the concept of metacontingency, a great contribution as a tool in the description and analysis of social behavior. Some metacontingency studies are presented in this paper and the behavior analyst's function in social issues is discussed, including analysis and modification of cultural practices.

  19. Muscle injury: review of experimental models.

    Science.gov (United States)

    Souza, Jaqueline de; Gottfried, Carmem

    2013-12-01

    Skeletal muscle is the most abundant tissue in the human body. Its main characteristic is the capacity to regenerate after injury independent of the cause of injury through a process called inflammatory response. Mechanical injuries are the most common type of the skeletal muscle injuries and are classified into one of three areas strain, contusion, and laceration. First, this review aims to describe and compare the main experimental methods that replicate the mechanical muscle injuries. There are several ways to replicate each kind of mechanical injury; there are, however, specific characteristics that must be taken into account when choosing the most appropriate model for the experiment. Finally, this review discusses the context of mechanical injury considering types, variability of methods, and the ability to reproduce injury models. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Organ models in wound ballistics: experimental study.

    Science.gov (United States)

    Ozer, Mustafa Tahir; Oğünç, Gökhan; Eryilmaz, Mehmet; Yiğit, Taner; Menteş, Mustafa Oner; Dakak, Mehmet; Uzar, Ali Ihsan; Oner, Köksal

    2007-01-01

    Effects of various types and diameters of guns and related treatment principles are different. Our study was performed to experimentally demonstrate the effects of different gunshots in body tissues. 9x19 mm hand-gun and 7.62x51 mm G-3 infantry rifle were used in the study. Injury models were created through hand-gun and rifle shootings at isolated soft tissue, lower extremity, liver and intestine tissue simulants made of ballistic candle. High-speed cameras were used to capture 1000 frames per second. Images were examined and wound mechanisms were evaluated. It was observed that the colon content distributed more within the surrounding tissues by the rifle shootings comparing with hand-gun shootings and could be an infection source due to the large size of the cavity in the colon. Especially when the bullets hitting the bone were investigated, it was seen that much more tissue injury occurs with high speed bullets due to bullet deformation and fragmentation. However, no significant difference was found between the effect of hand-gun and rifle bullets passing through the extremity without hitting the bone. To know the type of the gun that caused the injury and its characteristics will allow to estimate severity and size of the injury before the treatment and to focus on different alternatives of treatment. Therefore, use of appropriate models is required in experimental studies.

  1. Protective effects of ascorbic acid pretreatment in a rat model of intestinal ischemia-reperfusion injury: a histomorphometric study Efeito protetor do pré-tratamento com ácido ascóbico em modelo experimental de isquemia-reperfusão intestinal: um estudo histomorfométrico

    Directory of Open Access Journals (Sweden)

    Oscar Haruo Higa

    2007-01-01

    Full Text Available BACKGROUND: Ascorbic acid has shown promise in attenuation of intestinal ischemia-reperfusion (I/R injury. The aim of this study was to determine the protective effects of ascorbic acid on intestinal morphology during IR injury in rats. MATERIALS AND METHODS: We examined morphological changes in the small intestine of Wistar rats after (i 40 minutes of ischemia (I, (ii ischemia followed by 30 min of reperfusion (IR, (iii ischemia with ascorbic acid (IA, (iv ischemia followed by reperfusion and ascorbic acid (IRA and (v in a sham group (S. We used morphometry to evaluate the amount of villous architecture, crypts, necrosis, hemorrhagic infarcts and inflammatory cells at the mesenteric and antimesenteric borders of the small intestine. RESULTS: Ascorbic acid caused a significant reduction of antimesenteric villous hemorrhagic infarction (pINTRODUÇÃO: O ácido ascórbico tem se mostrado como um agente promissor na atenuação da lesão causada pela isquemia/reperfusão (IR. O objetivo deste estudo foi determinar os efeitos protetores do ácido ascórbico na morfologia intestinal durante a IR em ratos. MATERIAL E MÉTODOS: Examinamos alterações morfológicas no intestino delgado de ratos do tipo Wistar. Após 40 minutos de isquemia (I, isquemia seguida de reperfusão (IR, isquemia com tratamento com ácido ascórbico (IA, isquemia seguida por 30 minutos de reperfusão e tratamento com ácido ascórbico (IRA e do grupo sham (S. Utilizamos a morfometria para avaliar quantitativamente a arquitetura dos vilos da mucosa intestinal, criptas intestinais, necrose, hemorragia, células inflamatórias nas bordas mesentéricas e antimesentéricas do intestino delgado. RESULTADOS: O ácido ascórbico causou uma redução significativa (p<0,05 no infarto hemorrágico dos vilos intestinais da borda antimesentérica do intestino delgado após isquemia seguida por reperfusão, bem como redução da necrose dos vilos em ambas as bordas após a isquemia (p<0

  2. Experimental study of oil-water with paraffin precipitation in submarine pipelines; Estudo experimental do escoamento oleo-agua com precipitacao de parafinas em dutos submarinos

    Energy Technology Data Exchange (ETDEWEB)

    Bordalo, Sergio N.; Oliveira, Rafael de Castro [Universidade Estadual de Campinas (FEM/UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Petroleo], e-mail: bordalo@dep.fem.unicamp.br, e-mail: rafael@dep.fem.unicamp.br

    2006-07-01

    The deposition of paraffins in submarine pipelines poses a serious problem for the offshore petroleum production. Paraffins precipitate off oily solutions due to a temperature decrease according to the phase equilibrium conditions of the liquid-solid system. After some time, the continuous precipitation leads to deposits in the internal walls of the pipe, clogging the lines and promoting an increase in the head loss of the flow. Consequently, there is an increase in the pressure gradient required to maintain the flow, and the flow rate is reduced. A complete obstruction of the pipeline may occur. In the present work, this phenomenon was studied in a simulation of the subsea operational conditions, where the oil pipelines laying on the seabed are subjected to low temperatures, just a little above the freezing point of water. The pipeline behaves as a heat exchanger and the hot oil from the underground reservoir emerging from the wellhead is effectively cooled down to the point where paraffin precipitation occurs somewhere along the line. An experimental apparatus was built for a 25.4 mm (1 in) diameter pipe-flow model with 13 m of length, submerged in a chilling bath of near frozen water. Stream wise pressure and temperature gradients were measured, in order to evaluate the differences in the behavior of paraffin deposition between one-phase oil flow and two-phase oil-water flow. (author)

  3. Experimental Basis for IED Particle Model

    Science.gov (United States)

    Zheng-Johansson, J.

    2009-05-01

    The internally electrodynamic (IED) particle model is built on three experimental facts: a) electric charges present in all matter particles, b) an accelerated charge generates electromagnetic (EM) waves by Maxwell's equations and Planck energy equation, and c) source motion gives Doppler effect. A set of well-kwon basic particle equations have been predicted based on first-principles solutions for IED particle (e.g. arxiv:0812.3951, J Phys CS128, 012019, 2008); the equations are long experimentally validated. A critical review of the key experiments suggests that the IED process underlies these equations not just sufficiently but also necessarily. E.g.: 1) A free IED electron solution is a plane wave ψ= Ce^i(kdX-φT) requisite for producing the diffraction fringe in a Davisson-Germer experiment, and of also all basic point-like attributes facilitated by a linear momentum kd and the model structure. It needs not further be a wave packet which produces not a diffraction fringe. 2)The radial partial EM waves, hence the total ψ, of an IED electron will, on both EM theory and experiment basis -not by assumption, enter two slits at the same time, as is requisite for an electron to interfere with itself as shown in double slit experiments. 3) On annihilation, an electron converts (from mass m) to a radiation energy φ without an acceleration which is externally observable and yet requisite by EM theory. So a charge oscillation of frequency φ and its EM waves must regularly present internal of a normal electron, whence the IED model.

  4. DE TUBO DE SILICONE NO REPARO DE SEIO LACTÍFERO PAPILAR DE VACA LEITEIRA: ESTUDO EXPERIMENTAL

    Directory of Open Access Journals (Sweden)

    Duvaldo Eurides

    1994-01-01

    Full Text Available RESUMO Neste experimento, 10 vacas leiteiras foram distribuídas em dois grupos de igual número para implante de tubo de silicone no seio lactífero papilar. No grupo 1 a prótese foi fixada ao seio lactífero com pontos de sutura, permanecendo no local durante 60 dias. No grupo 2 a prótese foi implantada juntamente com uma sonda uretral para drenagem de leite e removida 12 dias após à intervenção cirúrgica. Em todos os animais foram feitas avaliações do fluxo de leite e estudos macroscópicos e microscópicos do seio lactífero papilar. Nos animais do grupo 1 os resultados apontaram alterações do seio lactífero papilar, mamite e deslocamento do tubo de silicone. No outro grupo os resultados foram excelentes, sendo o método mais vantajoso.

  5. Estado térmico de produtos armazenados em silos com sistema de aeração: estudo teórico e experimental Thermal state of stored products in storage bins with aeration system: experimental-theoretical study

    Directory of Open Access Journals (Sweden)

    Fabiane A. de Oliveira

    2007-04-01

    Full Text Available O resfriamento de grãos por ventilação de ar ambiente aplica-se amplamente nas etapas finais de secagem e para controle posterior da temperatura de grãos armazenados. O objetivo deste trabalho é realizar estudo teórico-experimental sobre o estado térmico de massa de grãos de soja sujeita à aeração. Foram obtidos dados experimentais sobre a dinâmica de resfriamento de massa pré-aquecida de grãos de soja para diferentes alturas da coluna de grãos e velocidades do ar. A análise dos resultados mostrou que a taxa de resfriamento varia significativamente durante todo o processo e em todo o domínio e a difusividade térmica das camadas não poderia ser considerada constante. Para simular a dinâmica de resfriamento, foram apresentados dois modelos matemáticos. No primeiro modelo, o domínio de resfriamento foi dividido pela fronteira móvel em duas zonas, representadas por diferentes difusividades térmicas (análogo de problema de Stefan. No outro modelo, todo o domínio foi dividido hipoteticamente em pequenas camadas e foi considerado que o processo de equilíbrio térmico entre o ar e a massa de grãos para essas camadas é atingido instantaneamente ("reatores homogêneos". Os resultados de simulações mostraram concordância satisfatória com os dados experimentais.The cooling of grains by ventilation with ambient air applies widely in the final stages of drying and for the subsequent temperature control of stored grains. The objective of this work is to carry out an experimental-theoretical study on the thermal state of a soybean mass, subject to the aeration. The experimental data on cooling dynamics of preheated soybean mass were obtained for different heights of the grain column and air velocities. The analysis of the results showed that the cooling rate varies significantly during all process in all domains and the thermal diffusivity of the layers cannot be considered as a constant. To simulate the cooling dynamics two

  6. Estudo experimental e numérico do sistema de admissão de um motor de combustão interna

    OpenAIRE

    Gustavo Rodrigues de Souza

    2010-01-01

    Durante o processo de admissão do ar em motores de combustão interna, nota-se que sua aspiração não é ideal, ou seja, o volume do cilindro não é completamente ocupado, devido à variação de sua massa específica e perdas de carga ao longo do sistema de alimentação. Conseqüentemente, a eficiência volumétrica no cilindro atinge valores ínfimos de desempenho, o que afeta diretamente a potência do motor. O trabalho consiste em um estudo numérico e experimental do sistema de admissão de um motor de ...

  7. Fechamento do coto distal do colon sigmoide comparando sutura Manual contÃnua com lacre plÃstico. Estudo experimental em cÃes

    OpenAIRE

    Carlos Renato Sales Bezerra

    2010-01-01

    Este estudo experimental verificou a eficÃcia do uso de um lacre plÃstico no fechamento do coto distal do cÃlon sigmÃide comparando com sutura manual em plano Ãnico, contÃnuo e extramucoso utilizando fio de polipropileno. Foram utilizados 30 animais (Canis familiaris) fÃmeas, pesando entre 8,0 e 18,0 kg, clinicamente sadios, oriundos do canil da Prefeitura Municipal de Teresina, PiauÃ. Foram distribuÃdos em dois grupos de 15 animais; submetidos a laparotomia com secÃÃo do cÃlon sigmÃide, com ...

  8. Experimental models of autoimmune inflammatory ocular diseases

    Directory of Open Access Journals (Sweden)

    Fabio Gasparin

    2012-04-01

    Full Text Available Ocular inflammation is one of the leading causes of blindness and loss of vision. Human uveitis is a complex and heterogeneous group of diseases characterized by inflammation of intraocular tissues. The eye may be the only organ involved, or uveitis may be part of a systemic disease. A significant number of cases are of unknown etiology and are labeled idiopathic. Animal models have been developed to the study of the physiopathogenesis of autoimmune uveitis due to the difficulty in obtaining human eye inflamed tissues for experiments. Most of those models are induced by injection of specific photoreceptors proteins (e.g., S-antigen, interphotoreceptor retinoid-binding protein, rhodopsin, recoverin, phosducin. Non-retinal antigens, including melanin-associated proteins and myelin basic protein, are also good inducers of uveitis in animals. Understanding the basic mechanisms and pathogenesis of autoimmune ocular diseases are essential for the development of new treatment approaches and therapeutic agents. The present review describes the main experimental models of autoimmune ocular inflammatory diseases.

  9. A human experimental model of episodic pain

    DEFF Research Database (Denmark)

    Petrini, Laura; Hennings, Kristian; Li, Xi

    2014-01-01

    were subjected to 45 min of intense painful cutaneous electrical stimulation (episodic pain session), using a stimulus paradigm that in animals has been shown to induce long-term potentiation. These electrical stimulations produced a verbal pain rating of approximately 85 on a 0-100 verbal rating scale......An experimental model of daily episodic pain was developed to investigate peripheral sensitization and cortical reorganization in healthy individuals. Two experiments (A and B) were conducted. Experiments A and B consisted of one and five consecutive days, respectively, in which the participants...... (VRS). Physiological (blood flow and axon flare reflex), psychophysical (perception threshold and verbal pain ratings) and electrophysiological (128 channels recorded somatosensory evoked potential (SEP)) measurements were recorded. The stimulation evoked a visible axon flare reflex and caused...

  10. Experimental validation of model Hortel Whillier; Validacion experimental del model de Hottel-Whillier

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez Munoz, F.; Cejudo Lopez, J. M.; Carrillo andres, A.

    2010-07-01

    Comparing the results of testing of a commercial flat-plate solar collector with a detailed implementation model of Hottel Whillier fin and tube. The validation procedure is based on comparing experimental and theoretical curves and more likely uncertainty bands. the model correctly predicts the end of profits and underestimates the 5% of losses, although a sensitivity analysis shows that this result is not attributable to the model itself but to the inputs with which it was implemented. The model has difficulty differentiating between the terms of linear and quadratic losses that appear in the quadratic fit curve. (Author) 1 refs.

  11. Spring-mediated skull expansion: overall effects in sutural and parasutural areas. An experimental study in rabbits Expansão craniana com molas: efeitos globais nas áreas suturais e parassuturais. Estudo experimental em coelhos

    Directory of Open Access Journals (Sweden)

    Rodrigo de Faria Valle Dornelles

    2010-04-01

    Full Text Available PURPOSE: The use of springs in cranial expansion has proven to be effective in the treatment of craniosynostosis. Spring-mediated expansion has been studied both in the sagittal and in parasagittal regions, especially in scaphocephaly. A rabbit model was used in the present study to analyze the effects of springs on the cranial vault and sutures. METHODS: Thirteen 4-week-old New Zealand rabbits were divided into 4 groups: in group I, only amalgam markers were used as control; in group II, amalgam markers were used and sagittal suturectomy was performed; in group III, amalgam markers were used, a sagittal suturectomy was performed and an expansible spring was fitted in the interparietal region and in group IV, markers were used and linear parasagittal craniectomy was carried out with springs. Animals were sacrificed after 2, 4, 8 and 12 weeks. Radiological control and histological analysis were performed in the area of spring implantation. RESULTS: In the groups using springs distraction of the craniectomy borders was greater than in those that did not use springs. New bone formation was observed in all groups, and was faster in group II. Bone growth started from the borders and depth. Bone regeneration presented a similar histological pattern in the groups with spring in the sagittal and parasagittal region. CONCLUSION: The rabbit model proved to be adequate for the analysis proposed by the study. The use of springs in the groups with sagittal and parasagittal osteotomy led to a similar distraction of amalgam markers and both groups had similar ossification histological pattern.OBJETIVO: O uso de molas na expansão craniana tem provado ser efetivo no tratamento da craniossinostoses. A expansão com molas tem sido estudada nas regiões sagital e parassagital, especialmente nas escafocefalias. Um modelo com coelho foi usado no presente estudo para analizar os efeitos das molas sobre a calota craniana e suturas. MÉTODOS: Treze coelhos Nova Zel

  12. Documentário: um outro campo experimental no estudo dos processos de subjetivação Documentary: another experimental field in the study of subjective processes

    Directory of Open Access Journals (Sweden)

    Giovanna De Marco

    2008-12-01

    Full Text Available Este artigo traz os problemas colocados para a pesquisa ao propor fazer um mapa audiovisual das configurações subjetivas em processo nas comunidades rurais de Massaroca, Juazeiro, Bahia, finalizando-o em um documentário. Foi feito um estudo bibliográfico e fílmico, particularmente sobre documentário nacional, de modo a adquirir as ferramentas conceituais e instrumentais próprias à linguagem audiovisual. Esse estudo e o trabalho de filmagem, montagem e edição problematizaram o modo de produção do documentário em questões que foram sistematizadas em três pontos: os processos de subjetivação na produção fílmica; o filme enquanto realidade ou ficção; o documentário como uma outra perspectiva metodológica. O documentário no qual a pesquisa estará se apresentando trará em imagens e sons fragmentos dos territórios existenciais das comunidades estudadas, nos quais a tensão existente entre o excesso e a escassez de água é processada, parcialmente, em linguagem; práticas produtivas, econômicas, políticas e éticas; manifestações culturais; religiosidade; afetividade; modos de cognição e percepção, etc.This article brings the problems discussed in the research, which aim at the creation of an audiovisual map of the subjective configurations that are taking place in the rural communities of Massaroca - a district of the city of Juazeiro, Bahia - and produce a documentary with this material. Bibliographic and cinematographic studies mainly about the Brazilian documentaries have been done in order to acquire conceptual and practical tools related to the audiovisual language. This study and the filming works and edition analyzed the documentary production method in three main points: the subjective processes in the cinematographic production; the film as reality or fiction; the documentary as another methodological perspective.

  13. Avaliação do efeito da glicosamina e condroitina na consolidação de fratura: estudo experimental em ratos Evaluating the effects of glucosamine and chondroitin in bone healing: experimental study in rats

    Directory of Open Access Journals (Sweden)

    Roberto Guarniero

    2007-07-01

    Full Text Available OBJETIVO: Avaliar o efeito da administração da condroitina e da glicosamina na consolidação de fratura em modelo animal. MÉTODOS: Este estudo experimental envolveu a utilização de 40 ratos machos adultos da raça Lewis. Os animais foram randomicamente divididos em quatro grupos de 10 animais cada, assim constituídos: grupo I, com administração de glicosamina; grupo II, com administração de condroitina; grupo III, administração da associação de glicosamina e condroitina; grupo IV, administração de água destilada (grupo controle. Realizou-se uma fratura fechada médio-diafisária da tíbia e fíbula direitas em cada animal, seguida da administração diária das drogas de acordo com o grupo, durante 30 dias. Após esse período, os animais foram sacrificados para estudo dos calos ósseos formados. Os critérios de avaliação foram a avaliação clínica da consolidação óssea, mensuração da densidade mineral do calo ósseo utilizando-se a densitometria óssea e cálculo da área do calo formado por meio de planigrafia. Os dados coletados foram avaliados com a técnica da análise de variância (ANOVA para verificar diferenças entre as médias nos quatro grupos estudados e com o teste de Tukey para comparação das médias duas a duas. Adotou-se nível de significância de 5% (alfa = 0,05. RESULTADOS: A utilização da condroitina e da glicosamina, tanto de maneira isolada quanto associadas, não resultou em aumento da área do calo ósseo ou da sua densidade mineral óssea, e não havendo melhora clínica da consolidação óssea. CONCLUSÃO: A administração de condroitina e glicosamina, neste estudo, não influenciou - quer de maneira positiva ou negativa - a consolidação de fraturas experimentais em ratos.OBJECTIVE: To evaluate the effects of administering chondroitin and glucosamine for bone healing in an animal model. METHODS: This experimental study involved the use of 50 male adult Lewis rats. The animals were

  14. Elastase-induced pulmonary emphysema: insights from experimental models

    Directory of Open Access Journals (Sweden)

    Mariana A. Antunes

    2011-12-01

    Full Text Available Several distinct stimuli can be used to reproduce histological and functional features of human emphysema, a leading cause of disability and death. Since cigarette smoke is the main cause of emphysema in humans, experimental researches have attempted to reproduce this situation. However, this is an expensive and cumbersome method of emphysema induction, and simpler, more efficacious alternatives have been sought. Among these approaches, elastolytic enzymes have been widely used to reproduce some characteristics of human cigarette smoke-induced disease, such as: augmentation of airspaces, inflammatory cell influx into the lungs, and systemic inflammation. Nevertheless, the use of elastase-induced emphysema models is still controversial, since the disease pathways involved in elastase induction may differ from those occurring in smoke-induced emphysema. This indicates that the choice of an emphysema model may impact the results of new therapies or drugs being tested. The aim of this review is to compare the mechanisms of disease induction in smoke and elastase emphysema models, to describe the differences among various elastase models, and to establish the advantages and disadvantages of elastase-induced emphysema models. More studies are required to shed light on the mechanisms of elastase-induced emphysema.Diversos estímulos podem ser utilizados para reproduzir características histológicas e funcionais do enfisema humano, uma das principais causas de incapacidade e morte. Uma vez que a fumaça de cigarro é a principal causa de enfisema em humanos, estudos experimentais têm tentado reproduzir esta situação. No entanto, esse é um método dispendioso e complicado para a indução do enfisema e, alternativas mais simples e eficazes, têm sido pesquisadas. Entre essas abordagens, enzimas elastolíticas vêm sendo amplamente utilizadas para reproduzir algumas das características do enfisema humano, tais como: aumento dos espaços a

  15. Effects of Anethole in Nociception Experimental Models

    Directory of Open Access Journals (Sweden)

    Alessandra Mileni Versuti Ritter

    2014-01-01

    Full Text Available This study investigated the antinociceptive activity of anethole (anethole 1-methoxy-4-benzene (1-propenyl, major compound of the essential oil of star anise (Illicium verum, in different experimental models of nociception. The animals were pretreated with anethole (62.5, 125, 250, and 500 mg/kg one hour before the experiments. To eliminate a possible sedative effect of anethole, the open field test was conducted. Anethole (62.5, 125, 250, and 500 mg/kg showed an antinociceptive effect in the writhing model induced by acetic acid, in the second phase of the formalin test (125 and 250 mg/kg in the test of glutamate (62.5, 125, and 250 mg/kg, and expresses pain induced by ACF (250 mg/kg. In contrast, anethole was not able to increase the latency time on the hot plate and decrease the number of flinches during the initial phase of the formalin test in any of the doses tested. It was also demonstrated that anethole has no association with sedative effects. Therefore, these data showed that anethole, at all used doses, has no sedative effect and has an antinociceptive effect. This effect may be due to a decrease in the production/release of inflammatory mediators.

  16. Tendon healing in vivo. An experimental model.

    Science.gov (United States)

    Abrahamsson, S O; Lundborg, G; Lohmander, L S

    1989-01-01

    Flexor tendon segments were incubated in a diffusion chamber in the subcutis of rabbits. Tendons incubated up to 6 weeks in the diffusion chamber showed proliferating and migrating cells from the epitenon cell layer as well as viable endotenon cells. Explants frozen in liquid nitrogen prior to incubation showed no signs of extrinsic cell contamination and remained non-viable indicating that no cell penetration occurred through the Millipore filter and that cell division seen in non-frozen and incubated tendons was an expression of intrinsic cellular proliferative capacity of the tendon. In tendon segments incubated in chambers for three weeks, collagen synthesis was reduced by 50% and the rate of cell proliferation measured as 3H-thymidine incorporation, was 15 times that of native tendons. Frozen and incubated tendons showed only traces of remaining matrix synthesis or cell proliferation. With this experimental model we have histologically and biochemically shown that tendons may survive and heal while the nutrition exclusively could be based on diffusion and the tendons have an intrinsic capacity of healing. The described model enables further studies on tendon healing and its regulation.

  17. Estudo experimental da influência da atividade muscular da face sobre o esqueleto da mesoestrutura facial em coelhos Experimental study on the influence of facial muscle activity on the facial mesostructure bones in rabbits

    Directory of Open Access Journals (Sweden)

    Andre Ricardo Mateus

    2008-10-01

    Full Text Available A partir do conceito da matriz funcional, surgiu a hipótese de que são os tecidos moles atuando sobre determinada peça óssea que determinam o processo de crescimento facial. A possibilidade de modificar a influência muscular, seja na fase de desenvolvimento facial, seja em pós-operatórios de cirurgia corretiva é de grande importância preventiva e deveria ser mais bem investigada, uma vez que poderia subtrair o número e magnitude destes procedimentos. DESENHO DO ESTUDO: Experimental em coelhos. OBJETIVO: Estimar a relevância da atividade muscular sobre o esqueleto facial, em coelhos de experimentação, durante sua fase de desenvolvimento facial. MATERIAL E MÉTODO: Foram estudados 37 coelhos de 2 meses de idade, divididos em grupo de estudo e grupo controle e seguidos por um período de 4 meses. Os animais do grupo de estudo tiveram seus nervos faciais seccionados no seu ramo cervical unilateralmente. O esqueleto da mesoestrutura facial era retirado para estudo morfométrico por programa de computação gráfica em fotografias digitalizadas realizadas nas peças. Os resultados obtidos sofreram análise estatística comparativa. CONCLUSÃO: Ausência de atividade muscular em uma metade da face produz desvio lateral da mesoestrutura facial para o mesmo lado em coelhos em desenvolvimento.Based on the functional matrix concept, scientists developed the hypothesis that soft tissue acting on certain bone pieces determines the process of facial growth. The possibility to modify muscle influence in the phase of facial development, or in postoperative of corrective surgery is of great preventive importance and it should be better investigated, since it could reduce the number and impact of these procedures. STUDY DESIGN: experimental in rabbits. AIM: to estimate the relevance of facial muscle activity on facial bones in lab rabbits. MATERIALS AND METHODS: 37 rabbits of two months of age were studied, divided in a study group and a control

  18. Deflazacort e cicatrização de anastomoses colônicas. Estudo experimental em ratos

    Directory of Open Access Journals (Sweden)

    Aguilar-Nascimento J.E. de

    2000-01-01

    Full Text Available OBJETIVO: O deflazacort é um novo corticóide com os mesmos efeitos antiinflamatórios dos demais, porém com menos efeitos colaterais. O objetivo deste estudo foi investigar os efeitos do deflazacort na cicatrização de anastomoses colônicas. MATERIAL E MÉTODO: 75 ratos Wistar foram randomizados em três grupos para receberem os seguintes tratamentos por gavagem: grupo controle (N=24= solução fisiológica; grupo deflazacort (N=25= 0,1 mg/Kg/dia dessa droga e, grupo dexametasona (N=26= 0,5 mg/Kg/dia substância. Após seis dias de tratamento, os animais foram submetidos à secção colônica, seguida de anastomose primária em um ponto situado a 2 cm acima da reflexão peritoneal. O tratamento com as soluções foi mantido até o sacrifício, que ocorreu no 3º ou no 6º dia de PO. Observou-se na necrópsia sinais de peritonite e deiscência de sutura. Realizou-se o teste de pressão de ruptura das anastomoses e dosou-se nessa região a concentração de hidroxiprolina e proteinas. RESULTADOS: Não houve diferença em relação à ocorrência de deiscência e peritonite. A pressão de ruptura foi semelhante no 3º dia. No 6º dia, ela foi maior (p <0.05 no grupo controle (180 [150-230] mmHg que nos grupos deflazacort (150 [120-180] mmHg e dexametasona (140 [100-180] mmHg. Não ocorreu diferença entre os grupos na dosagem de hidroxiprolina. A dosagem de protéinas foi maior no grupo dexametasona que nos controles no 3º PO. CONCLUSÕES: O uso de corticóides determina queda na resistência da anastomose colônica. O deflazacort apresenta os mesmos efeitos deletérios da dexametasona na cicatrização de anastomoses intestinais.

  19. Experimental models for Murray’s law

    Science.gov (United States)

    Akita, Dai; Kunita, Itsuki; Fricker, Mark D.; Kuroda, Shigeru; Sato, Katsuhiko; Nakagaki, Toshiyuki

    2017-01-01

    Transport networks are ubiquitous in multicellular organisms and include leaf veins, fungal mycelia and blood vessels. While transport of materials and signals through the network plays a crucial role in maintaining the living system, the transport capacity of the network can best be understood in terms of hydrodynamics. We report here that plasmodium from the large, single-celled amoeboid Physarum was able to construct a hydrodynamically optimized vein-network when evacuating biomass from confined arenas of various shapes through a narrow exit. Increasingly thick veins developed towards the exit, and the network spanned the arena via repetitive bifurcations to give a branching tree. The Hausdorff distance from all parts of the plasmodium to the vein network was kept low, whilst the hydrodynamic conductivity from distal parts of the network to the exit was equivalent, irrespective of the arena shape. This combination of spatial patterning and differential vein thickening served to evacuate biomass at an equivalent rate across the entire arena. The scaling relationship at the vein branches was determined experimentally to be 2.53-3.29, consistent with predictions from Murray’s law. Furthermore, we show that mathematical models for self-organised, adaptive transport in Physarum simulate the experimental network organisation well if the scaling coefficient of the current-reinforcement rule is set to 3. In simulations, this resulted in rapid development of an optimal network that minimised the combined volume and frictional energy in comparison with other scaling coefficients. This would predict that the boundary shear forces within each vein are constant throughout the network, and would be consistent with a feedback mechanism based on a sensing a threshold shear at the vein wall.

  20. Estudo Experimental e Numérico de Tensões Residuais em Juntas Soldadas com e sem Restrição

    Directory of Open Access Journals (Sweden)

    Daniel Casassola Gonçalves

    Full Text Available Resumo O conhecimento das tensões residuais geradas nos processos de soldagem apresenta especial importância no desempenho das estruturas e componentes soldados, pois durante a vida em serviço eles estarão sujeitos a diferentes níveis de carregamentos, que associados aos campos de tensões residuais pré-existentes podem levar à ruptura inesperada. Neste contexto, o presente trabalho tem como objetivo estudar o nível das tensões residuais geradas em juntas soldadas, pelo processo arame tubular (FCAW - Flux Cored Arc Welding, de aço ASTM A 131 Grau A, usadas na construção naval, por difração de raios-X, usando a técnica do sen2ψ. Foi realizado um estudo comparativo das mudanças nos campos de tensões quando adotadas restrições para manter a geometria de projeto da junta, bem como uma análise numérica computacional pelo método de elementos finitos, com os resultados obtidos pelo método experimental. A maioria dos resultados das tensões residuais mostrou que houve similaridade qualitativa, na sua natureza, entre o modelo e os experimentos nas regiões da zona termicamente afetada e do metal de solda. As análises de microdureza Vickers e a caracterização microestrutural por microscopia óptica das juntas soldadas complementaram o presente estudo.

  1. Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease: 2 - Attempts to upgrade the reliability and the efficacy of xenodiagnosis in chronic Chagas' disease Estudos em busca de um inseto modelo experimental para xenodiagnóstico em hospedeiros com doença de Chagas: 2. Tentativas para aumentar a credibilidade e a eficiência do xenodiagnóstico na doença de Chagas crônica

    Directory of Open Access Journals (Sweden)

    Alina Perlowagora Szumlewicz

    1987-06-01

    passo primordial na estratégia que visa a minimização de casos falso negativos, tanto nos levantamentos longitudinais da doença de Chagas, quanto na sua quimioterapia, apresentamos um estudo sobre a reconstrução do xenodiagnóstico, dando maior ênfase à dinâmica da população no xenodiagnóstico. Conseqüentemente, com o objetivo de levantar a credibilidade do xenodiagnóstico foram tomadas as seguintes medidas: 1. A densidade da população parasitária que em si não é um objetivo de investigações, mas retratando nitidamente a evolução e multiplicação do parasita, foi incorporada na triagem de insetos para o xenodiagnóstico. 2. Assumindo que a realimentação do inseto infectado é capaz de triplicar a densidade da população parasitária, este foi realimentado de duas em duas semanas em galinhas. 3. Na avaliação da resposta do inseto a infecção por T. cruzi foi medida no tubo digestivo completo no lugar da de fezes obtidas por compressão do barbeiro. 4. Sendo a densidade da população parasitária nos primeiros 15 dias após a infecção bem baixa, porém crescendo rapidamente nos 30 dias posteriores, adotou-se o intervalo de 45 dias para o exame do inseto alimentado no hospedeiro com a doença crônica. A eficácia do xenodiagnóstico parece estar associada com o inseto utilizado como seu agente. Das 9 espécies vetoras exploradas neste sentido o inseto da espécie Panstrongylus megistus mostrou-se o mais promissor, devido ao seu elevado índice de infectividade (91.2%, estando a maioria destes (61.9% com elevadas cargas parasitárias. Destaca-se também este inseto pela sua extraordinária capacidade de sustentar a rápida evolução e boa multiplicação de poucos parasitas ingeridos do hospedeiro na fase crônica. Isto está bem ilustrado na comparação do seu índice de positivos de 91.2% com este de 96.4% encontrado entre os insetos alimentados no mesmo hospedeiro com a infecção aguda, quando o numero estimado de...

  2. EFEITOS DO AGAROLâ E DO TRIGLICERILâ SOBRE A CICATRIZAÇÃO DE PELE: ESTUDO EXPERIMENTAL EM RATOS

    Directory of Open Access Journals (Sweden)

    Celso Fernando Ribeiro Araújo

    1998-10-01

    Full Text Available Desde os mais remotos tempos pesquisam-se incessantemente drogas que acelerem o processo cicatricial normal. No Hospital de Clínicas da UFPr preconiza-se a limpeza de feridas limpas com solução salina de NaCl a 0,9%. Alguns serviços têm utilizado empiricamente o Agarol® e o Trigliceril® na confecção do curativo após este procedimento. Este estudo objetivou avaliar experimentalmente a evolução de feridas cutâneas, em ratos, produzidas por incisão cirúrgica tratadas com solução de NaCl a 0,9%, Agarol® e Trigliceril® . Utilizou-se 24 ratos, divididos em três grupos: C, controle, submetido à troca diária de curativo após limpeza com solução de NaCl a 0,9%; grupo A com aplicação de Agarol® e grupo T com aplicação de Trigliceril®. Verificou-se que no terceiro e décimo quarto dias de pós-operatório o Agarolâ e o Triglicerilâ não influenciaram o processo cicatricial. No sétimo dia de pós-operatório verificou-se houve aumento da quantidade de tecido de granulação nos grupos tratados com Agarolâ e diminuição da neovascularização no grupo Triglicerilâ .For centuries, mankind has been incessantly researching with drugs that could accelerate the normal wound healing process. In the Hospital de Clinicas da Universidade Federal do Paraná, it has been recommended that the cleansing of clean wounds with saline solution of 0.9% sodium chloride, followed by a cover of dry dressing. However, some services have empirically used Agarol and Trigliceril in the confection of dressings after cleansing. This study aimed to evaluate the evolution of cutaneous wounds treated with normal saline, Agarol and Trigliceril in rats. A group of twenty-four rats were submitted to three skin circular incisions of 1.2 cm in diameter on their backs which exposed the subcutaneous tissue. The wounds were cleaned daily with normal saline solution. This group was distributed at random within three groups: Group C, control, received a clean

  3. Estudo comparativo experimental da estenose esofagogástrica nas suturas manual e mecânica

    Directory of Open Access Journals (Sweden)

    Francisco Américo Fernandes Neto

    Full Text Available Vinte e oito porcos foram aleatoriamente separados em dois grupos de 14 animais (A e B. Operados, o diâmetro anatômico das respectivas cárdias foi moldado e medido por um balonete de látex distendido por injeção de alginato, seguida de seção esofagogástrica. As anastomoses do grupo "A" foram realizadas ponto a ponto com fio de poliglactina 910-"000" e as do "B"com grampeadores "ILS". Sete animais dos subgrupos "A1"e"B1" foram reoperados e estudados após sete dias e outros sete porcos, dos subgrupos "A 2" e "B 2", foram no 14º dia. As peças anatômicas foram macroscopicamente examinadas, submetidas à prova pressórica, histologicamente estudadas, e os moldes, identificados e aferidos. Realizou-se estudo comparativo, prospectivo e randomizado da diferença percentual média de estenose ("delta P", obtida pela média dos diâmetros da cárdia antes e após sutura manual e mecânica. A análise estatística demonstrou insignificante variação na diferença de estenoses e dos tempos operatórios ("deltas Ps". Na sutura manual, o "delta P" foi 25,44% no sétimo dia pós-operatório e 15,88% no 14º dia e na mecânica, os percentuais do grupo de sete e 14 dias, respectivamente, foram 22,80% e 23,04%. As estenoses não prejudicaram o trânsito alimentar esofagogástrico. Macroscopicamente não houve vazamentos em cavidade livre apesar da microscopia ter evidenciado deiscências parciais bloqueadas em três animais. As aderências foram mais incidentes no grupo de sutura manual e a má coaptação das bordas viscerais, em alguns grampeamentos, resultou em cicatrização fibrótica com estenose mais acentuada. A sutura manual causou maior reação flogística perianastomótica e o grampeamento comprometeu mais intensamente a mucosa e a neo-angiogenêse. O trabalho parece ter demonstrado que as suturas manual e mecânica, se não são ideais, são satisfatórias e de considerável qualidade quando realizadas com mínimo traumatismo, boa

  4. Jogos de Empresas e Economia Experimental: um Estudo da Racionalidade Organizacional na Tomada de Decisão

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Aidar Sauaia

    2009-04-01

    Full Text Available Through the empirical analysis of behavior in business games, this paper contributes to the discussion of the classical theories on decision making, especially the studies of Simon. Primary data from sequential experiments were collected from business games that operated as laboratory experiments. According to the theorists of Experimental Economics and Behavioral Finance (Barberis & Thaler, 2003; Breinholt, Chesteen, & Cooper, 1992; Shiller, 2000; Simon, 1957, 1976, there was evidence that the choices of some individuals were rational, although in a limited way, producing results in disagreement with the expected utility theory. Their judgment prevented their organizations from maximizing the results because of some cognitive factors (Simon as cited in Bazerman, 2004, p. 6 such as simplification, lack of criteria, time restriction, cost restriction, perception and the ability to retain information in the memory. The subjectively rational decisions (rational a priori, which seemed to align means and ends, were shown to be inefficient (a posteriori reducing the organizational performance indicator (internal rate of return and lowering incentives for the managers (performance evaluation. The evidence shown here, based on objective data and observations, makes it possible to study problems in the field of Experimental Economics through business games

  5. Experimental study of the transient regime behaviour of an refrigerating machine evaporator; Estudo experimental do comportamento em regime transiente de um evaporador de uma maquina frigorifica

    Energy Technology Data Exchange (ETDEWEB)

    Machado, L.; Outtagarts, A.; Haberschill, P.; Lallemand, M. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France). Centre de Thermique de Lyon

    1995-07-01

    The aim of this work is the experimental study of the dynamic behaviour of a refrigerating machine evaporator. The superheat and cooling capacity responses to step exciting inlet and outlet refrigerant flow rates have been analysed for different operating points of the machine. The responses analysis allowed to determine the variations laws of the evaporators characteristics (gain, time constant) versus the compressor speed and evaporation temperature. (author)

  6. Injury Based on Its Study in Experimental Models

    Directory of Open Access Journals (Sweden)

    M. Mendes-Braz

    2012-01-01

    Full Text Available The present review focuses on the numerous experimental models used to study the complexity of hepatic ischemia/reperfusion (I/R injury. Although experimental models of hepatic I/R injury represent a compromise between the clinical reality and experimental simplification, the clinical transfer of experimental results is problematic because of anatomical and physiological differences and the inevitable simplification of experimental work. In this review, the strengths and limitations of the various models of hepatic I/R are discussed. Several strategies to protect the liver from I/R injury have been developed in animal models and, some of these, might find their way into clinical practice. We also attempt to highlight the fact that the mechanisms responsible for hepatic I/R injury depend on the experimental model used, and therefore the therapeutic strategies also differ according to the model used. Thus, the choice of model must therefore be adapted to the clinical question being answered.

  7. Biomass thermochemical gasification: Experimental studies and modeling

    Science.gov (United States)

    Kumar, Ajay

    The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For

  8. Study of process of water disinfection it saw energy solar using an experimental reactor; Estudo do proceso de desinfeccao de agua via energia solar utilizando um reator experimental

    Energy Technology Data Exchange (ETDEWEB)

    Batista, C. H.; Prado, L. R.; Lima, A. S.; Egues, S. M. S.; Araujo, P. M. M.

    2008-07-01

    In this work, was conducted an experimental study of the efficiency of a solar reactor in the disinfection of drinking water using photolysis (UV) and heterogeneous photo catalysis (TiO{sub 2}/UV). The experiments were conducted in batch mode, evaluating the effects of reactor inclination and the presence of a solar concentrator. The results indicated that the employed system was capable to promote the complete disinfection in 150 min using only the photo thermic effect, and in 120 min with the addition of immobilized TiO{sub 2} and the solar concentrator. (Author)

  9. Comunicações persuasivas e doação regular de sangue: um estudo experimental Persuasive communications and regular blood donation: an experimental study

    Directory of Open Access Journals (Sweden)

    Balduino Guedes Fernandes da Cunha

    2008-06-01

    Full Text Available Esta investigação teve por objetivos: verificar capitulação para a variável dependente "intenção comportamental de tornar-se doador(a regular de sangue", averiguar influência destas comunicações na variância da variável dependente, examinar a contribuição isolada da variável independente externa, à Teoria da Ação Racional e testar o ajuste da Teoria da Ação Racional ampliada para o comportamento e amostra estudados. Utilizou-se delineamento só pós-teste e procedimento duplo-cego, designando-se aleatoriamente 405 estudantes universitários, para os grupos experimental 1, experimental 2, controle-placebo e somente-controle. Resultados demonstraram: inexistir capitulação para os grupos experimentais; consideráveis percentuais de variância da variável dependente explicados pelas independentes dos grupos experimentais e controle-placebo; correlações satisfatórias e significativas para variáveis da teoria ampliada. A ausência de capitulação para a variável critério deveu-se, provavelmente, ao intervalo do tempo. Coube à estratégia persuasiva positiva maior variância da variável dependente. A obrigação moral demonstrou maior influência na intenção dos participantes em desempenhar o comportamento. Correlações corroboraram validades teórica e metodológica da teoria ampliada.This study aimed to: investigate yielding to the dependent variable "behavioral intent to become a regular blood donor", verify the impact of such communications on variance in the dependent variable, examine the single contribution of the external independent variable to the Rational Action Theory, and test the fit of the expanded Rational Choice Theory to the target behavior and sample. Only a post-test design and double-blinded procedure were used, randomly picking 405 university students for experimental groups 1 and 2, placebo control, and control only. The results showed: lack of yielding by the experimental groups; considerable

  10. PMWS: Experimental model and co-infections

    DEFF Research Database (Denmark)

    Allan, G. M.; McNeilly, F.; Ellis, J

    2004-01-01

    and pneumonia and typical histological lesions include lymphocytic depletion and multinucleated giant cell formation in lymph nodes, degeneration and necrosis of hepatocytes, and multifocal lymphohistocytic interstitial pneumonia. This communication will review the results of experimental infections...

  11. Isolamento e estudo experimental de duas novas culturas de bacilos ácido-alcool resistentes de muco nasal de leprosos

    Directory of Open Access Journals (Sweden)

    H. C. de Souza-Araujo

    1954-03-01

    . concludes that, according to his experience, the slower growing cultures of acid-fast bacilli isolated from leprosy material, are the more suitable for experimental work. Aknowledgement. The A. thanks to Miss MARIA DE LOURDES SANTANA for her valuable collaboration in the studies of the described cultures.

  12. Dynamic vehicle model for handling performance using experimental data

    Directory of Open Access Journals (Sweden)

    SangDo Na

    2015-11-01

    Full Text Available An analytical vehicle model is essential for the development of vehicle design and performance. Various vehicle models have different complexities, assumptions and limitations depending on the type of vehicle analysis. An accurate full vehicle model is essential in representing the behaviour of the vehicle in order to estimate vehicle dynamic system performance such as ride comfort and handling. An experimental vehicle model is developed in this article, which employs experimental kinematic and compliance data measured between the wheel and chassis. From these data, a vehicle model, which includes dynamic effects due to vehicle geometry changes, has been developed. The experimental vehicle model was validated using an instrumented experimental vehicle and data such as a step change steering input. This article shows a process to develop and validate an experimental vehicle model to enhance the accuracy of handling performance, which comes from precise suspension model measured by experimental data of a vehicle. The experimental force data obtained from a suspension parameter measuring device are employed for a precise modelling of the steering and handling response. The steering system is modelled by a lumped model, with stiffness coefficients defined and identified by comparing steering stiffness obtained by the measured data. The outputs, specifically the yaw rate and lateral acceleration of the vehicle, are verified by experimental results.

  13. Experimental study of core annular flow in the ultra viscous oil lift; Estudo experimental do escoamento anular oleo-agua (core flow) na elevacao de oleos ultraviscosos

    Energy Technology Data Exchange (ETDEWEB)

    Prada, Jose Walter Vanegas

    1999-07-01

    The increase in importance of heavy oil in the energy scenario makes it viable the exploitation of initially unprofitable reservoirs. This leads to the search of technologies capable to improve the development of heavy oil fields. In view of this scenario the present work proposes a new technology for heavy oil lift by using the core annular flow pattern (shortly 'coreflow'). This flow arrangement can be induced through the lateral injection of relatively small quantities of water, in order to get a lubricated oil core in the pipe. With this objective in mind, an experimental apparatus was built and tested at a laboratory scale (1 in. vertical pipe) with an 17.6 Pa.s oil and water at room temperatures. The experiments were quite successful. The core-flow allowed to reduce the friction pressure drop by more than 1000 times with respect to single phase oil flow and is of the same order as the flow of water alone at same total flow rate. The total pressure drop was reduced 93 times with respect to single phase oil flow. Finally, a physically based correlation for friction pressure drop in upward core flow was developed and validated with our measurements. Comparison of this correlation with data from another source gave excellent results. Besides the fluid properties and rates, the correlation requires the volumetric fraction of the oil, which is determined from another correlation. (author)

  14. Experimental comparison of models for ultrafast impact ionization is silicon

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Iwaszczuk, Krzysztof; Jepsen, Peter Uhd

    2016-01-01

    We compare experimentally the exponential and quadratic (Keldysh formula) impact ionization models using THz induced impact ionization in silicon. We demonstrate that the exponential model offers the best description of impact ionization process for ultrashort electric filed pulses....

  15. Studies on experimental models used for nutritional and biological ...

    African Journals Online (AJOL)

    The anatomical location for a successful implantation in order to reduce complications to the hearest minimum has been suggested . The maintenance of the implanted cannulae for the purpose of keeping the modified experimental model in perfect health is discussed. Key Words: Experimental Models, Nutritional Biological ...

  16. Experimental study in a reduced model of a primary clarifier

    OpenAIRE

    Pereira, Sylvia Manuela de Moura

    2013-01-01

    Dissertação de mestrado integrado em Engenharia Civil (área de especialização em Perfil de Hidráulica e Ambiente) A sedimentação é um processo simples e muito utilizado nas estações de tratamento de águas residuais. A sedimentação primária insere-se no tratamento primário de águas residuais, e consiste um processo físico de separação gravítica, que possibilita a remoção de sólidos em suspensão e coloidais da água residual. A presente dissertação apresenta um estudo experimental...

  17. Síndrome de disfunção de múltiplos órgãos induzida por sepse: estudo experimental em ratos Sepsis inducing syndrome of multiple organ dysfunction: an experimental study in rats

    Directory of Open Access Journals (Sweden)

    João Batista de Area Lima

    2011-06-01

    Full Text Available RACIONAL: A principal causa de morte em pacientes com sepse em cirurgia é a síndrome de disfunção de múltiplos órgãos. Assim, modelos experimentais que simulem alterações orgânicas da sepse em humanos são necessários. OBJETIVO: Apresentar dois modelos que induzem a síndrome de disfunção de múltiplos órgãos e comparar as alterações induzidas por inoculação endovenosa de 36UE de lipopolissacarídeo ou célula viável de Escherichia coli, em relação à: mortalidade e sobrevivência; nível de lipopolissacarídeo; liberação de fator de necrose tumoral alfa; alterações hematológicas e das funções hepática e renal. MÉTODO: Este estudo teve duração de sete dias e utilizou-se nele 50 ratos Wistar machos, divididos em três grupos: controle, lipopolissacarídeo e Escherichia coli. Os grupos experimento eram inoculados e separados em dois subgrupos, com inoculação a cada 24 ou 48 horas. No sétimo dia eram procedidas coletas de sangue e análise histopatológica de fígado, rins e pulmões. RESULTADOS: Houve sobrevivência de dez animais no grupo controle; zero no bacteriano de 24 horas e seis no de 48 horas; dez no lipopolissacarídeo de 24 horas e seis no de 48 horas. Nos grupos experimentais, os níveis de lipopolissacarídeo, fator de necrose tumoral alfa, leucócitos, plaquetas, bastonetes e as alterações renais e hepáticas foram superiores ao grupo controle. Houve alterações histopatológicas no grupo bacteriano. CONCLUSÃO: Os dois modelos de sepse induziram síndrome de disfunção de múltiplos órgãos, contudo a administração de 36UE de endotoxina a cada 48 horas pode ser utilizada com vantagens sobre os demais por não induzir morte em número significativo durante o período de sete dias.BACKGROUND: The leading cause of death in patients with sepsis in surgery is syndrome of multiple organ dysfunction. Thus, experimental models that simulate organic changes of sepsis in humans are required. AIM: To

  18. Improving the physiological realism of experimental models

    NARCIS (Netherlands)

    Vinnakota, Kalyan C.; Cha, Chae Y.; Rorsman, Patrik; Balaban, Robert S.; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A.; Jeneson, Jeroen A. L.

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these

  19. Experimental model of gastroesophageal reflux in rats Modelo experimental de refluxo gastroesofágico em ratos

    Directory of Open Access Journals (Sweden)

    Edmilson Vieira Gaia Filho

    2005-12-01

    Full Text Available PURPOSE: To develop an experimental model of gastroesophageal reflux in rats. METHODS: Sixty Wistar rats underwent surgery and were assigned to one of the three groups of twenty animals each. The animals in group A underwent total esophageal myectomy and, in group (B, underwent partial myectomy. The third group was the control group (C. A contrast radiographic study of the esophagus was performed to evaluate gastroesophageal reflux. The anatomopathological study of the esophagus was used to evaluate esophagitis. RESULTS: During the 30-day postoperative follow-up, 14 animals in group A presented with reflux of barium in the esophagus. The presence of barium in the esophagus was observed in 7 animals in group B and in 2 animals in the control group. The result of the histopathology examination was controversial. A marked weight loss in the rats undergoing total myectomy was observed, however there was no significant statistical difference. CONCLUSION: Total myectomy in the lower third of the esophagus caused gastroesophageal reflux in the majority of the animals.OBJETIVO: Desenvolver um modelo experimental de refluxo gastroesofágico em ratos. MÉTODOS: Sessenta ratos, Wistar, foram operados e distribuídos em três grupos de vinte animais. Os animais foram submetidos a miectomia total do esôfago em um grupo(A, e em outro grupo foram submetidos a miectomia parcial(B. O terceiro grupo foi o grupo controle(C. Para avaliar o refluxo gastroesofágico realizou-se o estudo radiológico contrastado do esôfago. O estudo anátomo-patológico do esôfago foi utilizado para avaliar esofagite. RESULTADOS: Durante os 30 dias de pós-operatório, 14 animais do grupo A apresentaram refluxo de Bário no esôfago. Em 07 animais do grupo B e em 02 do grupo controle, foram observados a presença de Bário no esôfago. O resultado do histopatológico foi controverso. Observou-se perda ponderal importante nos ratos submetidos a miectomia total, porém não existiu

  20. Experimental Diabetes Mellitus in Different Animal Models

    Directory of Open Access Journals (Sweden)

    Amin Al-awar

    2016-01-01

    Full Text Available Animal models have historically played a critical role in the exploration and characterization of disease pathophysiology and target identification and in the evaluation of novel therapeutic agents and treatments in vivo. Diabetes mellitus disease, commonly known as diabetes, is a group of metabolic disorders characterized by high blood glucose levels for a prolonged time. To avoid late complications of diabetes and related costs, primary prevention and early treatment are therefore necessary. Due to its chronic symptoms, new treatment strategies need to be developed, because of the limited effectiveness of the current therapies. We overviewed the pathophysiological features of diabetes in relation to its complications in type 1 and type 2 mice along with rat models, including Zucker Diabetic Fatty (ZDF rats, BB rats, LEW 1AR1/-iddm rats, Goto-Kakizaki rats, chemically induced diabetic models, and Nonobese Diabetic mouse, and Akita mice model. The advantages and disadvantages that these models comprise were also addressed in this review. This paper briefly reviews the wide pathophysiological and molecular mechanisms associated with type 1 and type 2 diabetes, particularly focusing on the challenges associated with the evaluation and predictive validation of these models as ideal animal models for preclinical assessments and discovering new drugs and therapeutic agents for translational application in humans.

  1. Experimental model to induce obesity in rats

    National Research Council Canada - National Science Library

    Vinicius Von Diemen; Eduardo Neubarth Trindade; Manoel Roberto Maciel Trindade

    2006-01-01

    .... Obesity can be induced in animals by neuroendocrine, dietary or genetic changes. The most widely used models to induce obesity in rats are a lesion of the ventromedial hypothalamic nucleus (VMH...

  2. Optimization of experimental human leukemia models (review

    Directory of Open Access Journals (Sweden)

    D. D. Pankov

    2012-01-01

    Full Text Available Actual problem of assessing immunotherapy prospects including antigenpecific cell therapy using animal models was covered in this review.Describe the various groups of currently existing animal models and methods of their creating – from different immunodeficient mice to severalvariants of tumor cells engraftment in them. The review addresses the possibility of tumor stem cells studying using mouse models for the leukemia treatment with adoptive cell therapy including WT1. Also issues of human leukemia cells migration and proliferation in a mice withdifferent immunodeficiency degree are discussed. To assess the potential immunotherapy efficacy comparison of immunodeficient mouse model with clinical situation in oncology patients after chemotherapy is proposed.

  3. Estudo experimental da influência das dimensões dos grânulos de hidroxiapatita na integração óssea Influence od dimensions of hydroxiapatite granules upon bone integration: an experimental study

    Directory of Open Access Journals (Sweden)

    Adriana Santos Barone Moreira

    2003-12-01

    Full Text Available Foi realizado estudo experimental em ratos Wistar para a avaliação da integração óssea dos grânulos de hidroxiapatita de diferentes tamanhos (212µ, 500µ e 1000µ. Os animais foram divididos em três grupos experimentais (dois grupos com 15 animais e um grupo com 25 animais e foram sacrificados com 30, 90 e 180 dias após a implantação da hidroxiapatita, que foi utilizada para o preenchimento de falha óssea produzida no fêmur. Dez animais formaram o grupo controle, cujo falha produzida no fêmur não foi preenchida com a HA. Os animais foram avaliados por meio de estudo radiológico e histológico, utilizando-se microscopia de luz para a avaliação da interface entre o tecido ósseo e a hidroxiapatita. Foi observado que os grânulos de hidroxiapatita utilizados para o preenchimento da falha óssea foram biocompatíveis e que a restauração da falha óssea ocorreu mais rapidamente nas falhas ósseas preenchidas com a HA que apresentava grânulos de menor diâmetro (212µ.This trial was performed in Wistar rats to evaluate bone integration of hydroxyapatite (HA granules of different sizes (212 µm, 500 µm, and 1000 µm. The animals were divided into three experimental groups, that is, two groups of 15 animals and one group of 25 animals, which were killed, respectively, 30, 90 and 180 days after the implantation of the hydroxyapatite employed to fill the bone defects produced in the rats' femurs. Additionally, a control group included ten rats whose induced femur defects were not filled with HA. All animals were radiologically and histologically examined by light microscopy, in order to evaluate the bone tissue / hydroxyapatite interface. It was seen that the hydroxyapatite granules employed to fill the bone defects were biocompatible and that the bone defect was restored faster in the bone defects filled with HA whose granules had smaller diameters (212 µm.

  4. Experimental model of arteriovenous malformation in vitro using biological grafts

    Directory of Open Access Journals (Sweden)

    Sandu Aurelia Mihaela

    2015-06-01

    Full Text Available Introduction: Brain arteriovenous malformations (AVMs represent a serious health problem all around the world. Experimental models help to better understand the pathophysiology of these lesions. Experiment: We performed an experimental model of AVM using biological grafts, arteries and veins harvested from chicken wings at the elbow joint. We used 14 vessels and we performed 20 end-to-end anastomoses to create a nidus with a single feeding artery and a single draining vein. The system was irrigated with colored solution. The experiment was done according with law in force regarding experimental research activity. Conclusions: Experimental models allow us to understand the hemodynamics and predict the outcome of brain AVMs in humans. This experimental model is a useful tool in understanding the hemodynamic properties of brain AVMs. It is very useful in vascular anastomosis training

  5. An experimental comparison of modelling techniques for speaker ...

    Indian Academy of Sciences (India)

    Most of the existing modelling techniques for the speaker recognition task make an implicit assumption of sufficient data for speaker modelling and hence may lead to poor modelling under limited data condition. The present work gives an experimental evaluation of the modelling techniques like Crisp Vector Quantization ...

  6. Experimental and numeric studies of one electro-optical flexible pipe (umbilical); Estudos numericos e experimentais de um umbilical eletro-optico

    Energy Technology Data Exchange (ETDEWEB)

    Lepore, Paula Ferreira; Buelta Martinez, Miguel Angel [Sao Paulo Univ., SP (Brazil). Escola Politecnica

    2005-07-01

    This work had as objective to develop, to implant, to survey and to test an experimental and numerical model of structural, applicable analysis of umbilical structures. An ample study of the behavior of its constituent layers was carried through, in special of its nucleus and material constituents, when operating under different conditions of tensions and deformations. As support for this work, experimental tests for one type of electro-optic umbilical with typical transversal section had been carried through. This was made with the intention to optimize the developed numerical model. With this model of structural analysis, the project of umbilicals could highly improved, in terms of the total weight of the handle, which is one of the great problems for its use in great depths, with the maximum of efficiency and the minimum of losses, foreseeing and hindering operation imperfections that can come to occur due to extreme deformation or electric rupture of the layers, hoses or handles. (author)

  7. Hysteretic behavior of a belt tensioner: modeling and experimental investigation

    OpenAIRE

    Michon, Guilhem; Manin, Lionel; Dufour, Regis

    2005-01-01

    In this paper we describe the modeling of the hysteretic behavior of belt tensioners. An initial experimental device is composed only of the tensioner by using forcing frequencies, preloads and deflection amplitudes. It permits the identification of the parameters of the restoring force model used. Comparison of the measured and predicted force deflection loops of the tensioner subjected to large deflections permits preliminary validation of the model.The second experimental device consists o...

  8. Experimental Measurement, Analysis and Modelling of Dependency ...

    African Journals Online (AJOL)

    We propose a direct method of measurement of the total emissivity of opaque samples on a range of temperature around the ambient one. The method rests on the modulation of the temperature of the sample and the infra-red signal processing resulting from the surface of the sample we model the total emissivity obtained ...

  9. Efeito da desnutrição na cicatrização de anastomoses colônicas: estudo experimental em ratos Effects of malnutrition on colonic anastomosis healing: an experimental study in rats

    Directory of Open Access Journals (Sweden)

    Manuela Molina Ferreira

    2006-09-01

    Full Text Available A deiscência de anastomose é uma das mais graves complicações advindas de operações do tubo gastrintestinal. Algumas condições gerais podem prejudicar o processo de cicatrização, tais como: desnutrição e hipoalbuminemia. Este estudo experimental teve como objetivo avaliar a cicatrização de anastomoses colônicas na vigência de desnutrição protéico-calórica e hipoalbuminemia. Dividimos os animais em dois grupos, sendo um deles o controle e o outro desnutrido (ingestão diária de metade da ração do grupo controle por vinte dias. O peso corporal, a albumina sérica, a evolução clínica, a cavidade abdominal, os aspectos macro e microscópicos da anastomose, a esteatose hepática e a concentração tecidual de hidroxiprolina foram observadas em cada animal. Pudemos notar que o método utilizado para desnutrir os animais mostrou-se eficaz, uma vez que houve redução significativa do peso do grupo experimental. Observamos que o grupo desnutrido apresentou dados necroscópicos de pior prognóstico e mortalidade superior ao grupo controle. Concluímos que a desnutrição influencia negativamente na cicatrização de anastomoses colônicas e aumenta significativamente a mortalidade.Dehiscence of colonic anastomosis is one of the most severe complications after gastrointestinal surgery. The intestinal anastomosis healing complication is associated to several factors like malnutrition and hypoalbuminemia. This is an experimental study that aimed to evaluate the colonic anastomosis healing in malnutrition and hypoalbuminemia conditions. Animals were separated in two experimental groups: control and submitted to malnutrition (daily food intake as half of the control group per 20 days. Body weight, clinical outcome, serum albumin, abdominal cavity aspects, gross and microscopic aspects of the anastomosis, hepatic steatosis and tissue hydroxyproline dosage were compared between groups. Our results show that malnutrition development was

  10. New experimental model for training in videosurgery Novo modelo experimental para treinamento em videocirurgia

    Directory of Open Access Journals (Sweden)

    Danilo Malta Batista

    2012-10-01

    Full Text Available PURPOSE: To develop a new experimental model of lower cost for training in videosurgery. METHODS: This project was performed at the Nucleus of Experimental Surgery of the Bahiana School of Medicine and Public Health, based on previous models described in the literature and under the supervision of the full professor of Operative Technique and Experimental Surgery II. It was made a model cube-shaped, made of wood, with holes distributed in various locations, rubber stoppers for the holes and lined externally with carpet, and internally with laminate. RESULTS: The new experimental model is of low cost and reproduces quite faithfully several videosurgical procedures. CONCLUSION: Medical schools interested in the subject may adopt the new model for training in videosurgery without the need of high costs for making and using these models.OBJETIVO: Desenvolver um novo modelo experimental de baixo custo para treinamento em videocirurgia MÉTODOS: Este projeto foi conduzido no Núcleo de Cirurgia Experimental da Escola Bahiana de Medicina e Saúde Pública, baseado em modelos prévios descritos na literatura e sob a supervisão do professor titular de Técnica Operatória e Cirurgia Experimental II. Foi feito um modelo em formato de cubo, de madeira, com furos distribuídos em vários locais, tampas de borracha para os orifícios e forrado externamente com carpete e internamente com laminado. RESULTADOS: O novo modelo experimental desenvolvido é de baixo custo e reproduz de forma bastante fiel diversos procedimentos videocirúrgicos. CONCLUSÃO: Faculdades médicas interessadas no tema poderão adotar o novo modelo para o treinamento em videocirurgia sem que sejam necessários gastos elevados para a confecção e o uso desses modelos.

  11. Different experimental approaches in modelling cataractogenesis

    Science.gov (United States)

    Kyselova, Zuzana

    2010-01-01

    Cataract, the opacification of eye lens, is the leading cause of blindness worldwide. At present, the only remedy is surgical removal of the cataractous lens and substitution with a lens made of synthetic polymers. However, besides significant costs of operation and possible complications, an artificial lens just does not have the overall optical qualities of a normal one. Hence it remains a significant public health problem, and biochemical solutions or pharmacological interventions that will maintain the transparency of the lens are highly required. Naturally, there is a persistent demand for suitable biological models. The ocular lens would appear to be an ideal organ for maintaining culture conditions because of lacking blood vessels and nerves. The lens in vivo obtains its nutrients and eliminates waste products via diffusion with the surrounding fluids. Lens opacification observed in vivo can be mimicked in vitro by addition of the cataractogenic agent sodium selenite (Na2SeO3) to the culture medium. Moreover, since an overdose of sodium selenite induces also cataract in young rats, it became an extremely rapid and convenient model of nuclear cataract in vivo. The main focus of this review will be on selenium (Se) and its salt sodium selenite, their toxicological characteristics and safety data in relevance of modelling cataractogenesis, either under in vivo or in vitro conditions. The studies revealing the mechanisms of lens opacification induced by selenite are highlighted, the representatives from screening for potential anti-cataract agents are listed. PMID:21217865

  12. Experimentally testing the standard cosmological model

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.N. (Chicago Univ., IL (USA) Fermi National Accelerator Lab., Batavia, IL (USA))

    1990-11-01

    The standard model of cosmology, the big bang, is now being tested and confirmed to remarkable accuracy. Recent high precision measurements relate to the microwave background; and big bang nucleosynthesis. This paper focuses on the latter since that relates more directly to high energy experiments. In particular, the recent LEP (and SLC) results on the number of neutrinos are discussed as a positive laboratory test of the standard cosmology scenario. Discussion is presented on the improved light element observational data as well as the improved neutron lifetime data. alternate nucleosynthesis scenarios of decaying matter or of quark-hadron induced inhomogeneities are discussed. It is shown that when these scenarios are made to fit the observed abundances accurately, the resulting conclusions on the baryonic density relative to the critical density, {Omega}{sub b}, remain approximately the same as in the standard homogeneous case, thus, adding to the robustness of the standard model conclusion that {Omega}{sub b} {approximately} 0.06. This latter point is the deriving force behind the need for non-baryonic dark matter (assuming {Omega}{sub total} = 1) and the need for dark baryonic matter, since {Omega}{sub visible} < {Omega}{sub b}. Recent accelerator constraints on non-baryonic matter are discussed, showing that any massive cold dark matter candidate must now have a mass M{sub x} {approx gt} 20 GeV and an interaction weaker than the Z{sup 0} coupling to a neutrino. It is also noted that recent hints regarding the solar neutrino experiments coupled with the see-saw model for {nu}-masses may imply that the {nu}{sub {tau}} is a good hot dark matter candidate. 73 refs., 5 figs.

  13. Tesla coil theoretical model and experimental verification

    OpenAIRE

    Voitkans, Janis; Voitkans, Arnis

    2014-01-01

    Abstract – In this paper a theoretical model of a Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wired format, where the line voltage is measured against electrically neutral space. It is shown that equivalent two-wired scheme can be found for a single-wired scheme and already known long line theory can be applied to a Tesla coil. Formulas for calculation of voltage in a Tesla coil by coordinate and calculation of resonance fre...

  14. Mathematical Models and the Experimental Analysis of Behavior

    Science.gov (United States)

    Mazur, James E.

    2006-01-01

    The use of mathematical models in the experimental analysis of behavior has increased over the years, and they offer several advantages. Mathematical models require theorists to be precise and unambiguous, often allowing comparisons of competing theories that sound similar when stated in words. Sometimes different mathematical models may make…

  15. The effect of Cordia platythyrsa on various experimental models of ...

    African Journals Online (AJOL)

    The effect of Cordia platythyrsa on various experimental models of pain and carrageenan induced inflammation. Benedicta N Nkeh-Chungag, Eugene J Ndebia, Joseph T Mbafor, Lonwabo A Dotwana, OO Oyedeji, Jehu E Iputo ...

  16. Microplasticity of MMC. Experimental results and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Maire, E. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Lormand, G. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Gobin, P.F. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Fougeres, R. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France))

    1993-11-01

    The microplastic behavior of several MMC is investigated by means of tension and compression tests. This behavior is assymetric : the proportional limit is higher in tension than in compression but the work hardening rate is higher in compression. These differences are analysed in terms of maxium of the Tresca's shear stress at the interface (proportional limit) and of the emission of dislocation loops during the cooling (work hardening rate). On another hand, a model is proposed to calculate the value of the yield stress, describing the composite as a material composed of three phases : inclusion, unaffected matrix and matrix surrounding the inclusion having a gradient in the density of the thermally induced dilocations. (orig.).

  17. Experimental investigation of a flapping wing model

    Energy Technology Data Exchange (ETDEWEB)

    Hubel, Tatjana Y.; Tropea, Cameron [Technische Universitaet Darmstadt, Fachgebiet Stroemungslehre und Aerodynamik, Darmstadt (Germany)

    2009-05-15

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle. (orig.)

  18. Statistical approach for uncertainty quantification of experimental modal model parameters

    DEFF Research Database (Denmark)

    Luczak, M.; Peeters, B.; Kahsin, M.

    2014-01-01

    . This paper aims at a systematic approach for uncertainty quantification of the parameters of the modal models estimated from experimentally obtained data. Statistical analysis of modal parameters is implemented to derive an assessment of the entire modal model uncertainty measure. Investigated structures...... estimates obtained from vibration experiments. Modal testing results are influenced by numerous factors introducing uncertainty to the measurement results. Different experimental techniques applied to the same test item or testing numerous nominally identical specimens yields different test results...

  19. In silico simulations of experimental protocols for cardiac modeling.

    Science.gov (United States)

    Carro, Jesus; Rodriguez, Jose Felix; Pueyo, Esther

    2014-01-01

    A mathematical model of the AP involves the sum of different transmembrane ionic currents and the balance of intracellular ionic concentrations. To each ionic current corresponds an equation involving several effects. There are a number of model parameters that must be identified using specific experimental protocols in which the effects are considered as independent. However, when the model complexity grows, the interaction between effects becomes increasingly important. Therefore, model parameters identified considering the different effects as independent might be misleading. In this work, a novel methodology consisting in performing in silico simulations of the experimental protocol and then comparing experimental and simulated outcomes is proposed for parameter model identification and validation. The potential of the methodology is demonstrated by validating voltage-dependent L-type calcium current (ICaL) inactivation in recently proposed human ventricular AP models with different formulations. Our results show large differences between ICaL inactivation as calculated from the model equation and ICaL inactivation from the in silico simulations due to the interaction between effects and/or to the experimental protocol. Our results suggest that, when proposing any new model formulation, consistency between such formulation and the corresponding experimental data that is aimed at being reproduced needs to be first verified considering all involved factors.

  20. Partial gastrectomy associated to anterior truncal vagotomy: alterations in metabolism of the calcium. Experimental study in rats Gastrectomia parcial e vagotomia troncular anterior: alterações no metabolismo de cálcio. Estudo experimental em ratos

    Directory of Open Access Journals (Sweden)

    Elisvânia Freitas dos Santos

    2009-06-01

    ção. RESULTADOS: Os animais controle apresentaram médias estatísticas maiores (P<0.05 para o consumo de dieta, ganho de peso, cálcio sérico, cálcio urinário, excreção de cálcio nas fezes, absorção aparente de cálcio e atividade da enzima fosfatase alcalina comparados aos animais do grupo gastrectomizado. Entretanto, a concentração de cálcio ósseo foi superior no grupo de animais gastrectomizados (P<0,05 quando comparado com o grupo controle. CONCLUSÃO: A gastrectomia parcial associada à vagotomia troncular anterior mostrou ser um bom modelo experimental para estudo com o metabolismo de cálcio, ocasionando diminuição da absorção de cálcio, cálcio sérico, cálcio urinário e fosfatase alcalina. No entanto, para alterações a nível ósseo em ratos, sugere-se um estudo experimental em período maior.

  1. The use of Alloxan and Streptozotocin in Experimental Diabetes Models

    Directory of Open Access Journals (Sweden)

    Zehra Kurçer

    2012-06-01

    Full Text Available Diabetes is a chronic metabolic disease which leads to several acute and chronic complications, morbidity and mortality, and decreased lifespan and quality of life. Therefore, in research studies that aim to enlighten the pathogenesis of diabetes and investigate possible treatment strategies, experimental animal models of diabetes provide many advantages to the investigator. Models of diabetes obtained by chemical induction, diet, surgical manipulations or combination thereof and also new genetically modified animal models are some of the experimental models. Alloxan and streptozotocin (STZ, which are toxic glucose analogues that preferentially accumulate in pancreatic beta cells, are widely used toxic agents to induce experimental diabetes in animals. This review gives an overview on the use of alloxan and STZ to induce chemical diabetes models with reference to their mechanisms, utilizable doses, advantages and disadvantages in diabetes research. Turk Jem 2012; 16: 34-40

  2. Estudo experimental e teórico da redução de bases de Schiff derivadas da 3,3-difenilpropilamina

    Directory of Open Access Journals (Sweden)

    Esteves-Souza Andressa

    2004-01-01

    Full Text Available A series of seven Schiff bases have been synthesized from 3,3-diphenylpropilamine and substituted benzaldehydes. These imines were treated with NaBH4 in ethanol affording the corresponding amines in 98-55% yields. A molecular modeling study was performed with the Schiff bases in order to compare the theoretical parameters with the experimental results. The theoretical parameters were obtained by AM1 and PM3 semi-empirical methods. The analysis of charge, electron densities and LUMO coefficients suggested that the most favorable interactions should occur with Schiff bases containing electron-donating groups, in accordance with experimental yields, showing that the higher reactivity is due to higher electrophilic character of imine carbons.

  3. Design and Implementation of an Experimental Segway Model

    Science.gov (United States)

    Younis, Wael; Abdelati, Mohammed

    2009-03-01

    The segway is the first transportation product to stand, balance, and move in the same way we do. It is a truly 21st-century idea. The aim of this research is to study the theory behind building segway vehicles based on the stabilization of an inverted pendulum. An experimental model has been designed and implemented through this study. The model has been tested for its balance by running a Proportional Derivative (PD) algorithm on a microprocessor chip. The model has been identified in order to serve as an educational experimental platform for segways.

  4. Experimental and modeling studies of mass transfer in ...

    African Journals Online (AJOL)

    Gaining a better understanding of mass transfer problems in encapsulated cell systems and in tissue engineering requires both experimental investigations and mathematical modelling. Specific mass transfer studies are reviewed including oxygen transfer in immobilised animal cell culture systems, modelling of ...

  5. Using an experimental model for the study of therapeutic touch.

    Science.gov (United States)

    dos Santos, Daniella Soares; Marta, Ilda Estéfani Ribeiro; Cárnio, Evelin Capellari; de Quadros, Andreza Urba; Cunha, Thiago Mattar; de Carvalho, Emilia Campos

    2013-02-01

    to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic Touch for 15 minutes during three days. the data showed statistically significant differences in the nociceptive threshold and in the paw circumference of the animals from the experimental group on the second day of the experiment. the experiment model involving animals can contribute to study the effects of Therapeutic Touch on inflammation, and adjustments are suggested in the treatment duration, number of sessions and experiment duration.

  6. Linking Experimental Characterization and Computational Modeling in Microstructural Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Demirel, Melik Cumhar [Univ. of Pittsburgh, PA (United States)

    2002-06-01

    It is known that by controlling microstructural development, desirable properties of materials can be achieved. The main objective of our research is to understand and control interface dominated material properties, and finally, to verify experimental results with computer simulations. In order to accomplish this objective, we studied the grain growth in detail with experimental techniques and computational simulations. We obtained 5170-grain data from an Aluminum-film (120μm thick) with a columnar grain structure from the Electron Backscattered Diffraction (EBSD) measurements. Experimentally obtained starting microstructure and grain boundary properties are input for the three-dimensional grain growth simulation. In the computational model, minimization of the interface energy is the driving force for the grain boundary motion. The computed evolved microstructure is compared with the final experimental microstructure, after annealing at 550 ºC. Two different measures were introduced as methods of comparing experimental and computed microstructures. Modeling with anisotropic mobility explains a significant amount of mismatch between experiment and isotropic modeling. We have shown that isotropic modeling has very little predictive value. Microstructural evolution in columnar Aluminum foils can be correctly modeled with anisotropic parameters. We observed a strong similarity between grain growth experiments and anisotropic three-dimensional simulations.

  7. Development of a fault test experimental facility model using Matlab

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Iraci Martinez; Moraes, Davi Almeida, E-mail: martinez@ipen.br, E-mail: dmoraes@dk8.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The Fault Test Experimental Facility was developed to simulate a PWR nuclear power plant and is instrumented with temperature, level and pressure sensors. The Fault Test Experimental Facility can be operated to generate normal and fault data, and these failures can be added initially small, and their magnitude being increasing gradually. This work presents the Fault Test Experimental Facility model developed using the Matlab GUIDE (Graphical User Interface Development Environment) toolbox that consists of a set of functions designed to create interfaces in an easy and fast way. The system model is based on the mass and energy inventory balance equations. Physical as well as operational aspects are taken into consideration. The interface layout looks like a process flowchart and the user can set the input variables. Besides the normal operation conditions, there is the possibility to choose a faulty variable from a list. The program also allows the user to set the noise level for the input variables. Using the model, data were generated for different operational conditions, both under normal and fault conditions with different noise levels added to the input variables. Data generated by the model will be compared with Fault Test Experimental Facility data. The Fault Test Experimental Facility theoretical model results will be used for the development of a Monitoring and Fault Detection System. (author)

  8. Linking Experimental Characterization and Computational Modeling in Microstructural Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Demirel, Melik Cumhur [Univ. of California, Berkeley, CA (United States)

    2002-06-01

    It is known that by controlling microstructural development, desirable properties of materials can be achieved. The main objective of our research is to understand and control interface dominated material properties, and finally, to verify experimental results with computer simulations. In order to accomplish this objective, we studied the grain growth in detail with experimental techniques and computational simulations. We obtained 5170-grain data from an Aluminum-film (120μm thick) with a columnar grain structure from the Electron Backscattered Diffraction (EBSD) measurements. Experimentally obtained starting microstructure and grain boundary properties are input for the three-dimensional grain growth simulation. In the computational model, minimization of the interface energy is the driving force for the grain boundary motion. The computed evolved microstructure is compared with the final experimental microstructure, after annealing at 550 ºC. Two different measures were introduced as methods of comparing experimental and computed microstructures. Modeling with anisotropic mobility explains a significant amount of mismatch between experiment and isotropic modeling. We have shown that isotropic modeling has very little predictive value. Microstructural evolution in columnar Aluminum foils can be correctly modeled with anisotropic parameters. We observed a strong similarity

  9. Experimental-analytical method of technological processes modeling in education

    OpenAIRE

    Efremov German I.; Geller Julia A.

    2016-01-01

    The article considers general modeling techniques used in the study in education at different stages. The classification of different types of models and main stages of the simulation are considered. It is shown that in the course “Process of simulation” for technical areas of the Universities required the category of “Experimental-analytical simulation method”. For example, a new textbook for bachelors “Modeling of chemical-technological processes” shows that the section facilitates the comp...

  10. Estudo teórico e experimental da desidratação da tainha em secador alternativo e estufa comercial

    Directory of Open Access Journals (Sweden)

    Jesus Marlinaldo Medeiros

    2016-09-01

    Full Text Available A tainha é um dos peixes mais abundantes do litoral brasileiro. Os peixes marinhos, como a tainha, constituem um dos recursos alimentares de melhor qualidade e abundância, graças ao valor nutritivo, fácil digestibilidade e composição equilibrada. No entanto, grande parte do pescado extraído é desperdiçado, devido a sua deterioração rápida, que ocorre em menos de 24 horas. Para combater o desperdício, destaca-se o processo de secagem, método de conservação que influencia no tempo de preservação, qualidade e durabilidade dos alimentos. A escolha pela técnica de secagem convectiva se deve à simplicidade e ao baixo custo de instalação e operação dos equipamentos usados. A secagem convectiva utiliza ar quente, aumentando a sua temperatura, diminuindo a sua umidade relativa e absorvendo a umidadecontida no material a secar. Neste estudo, investigou-se o processo da secagem convectiva da tainha, visando determinar o tempo de secagem – por meio de ensaios numa bancada experimental construída em laboratório fazendo uso de materiais alternativos – e também testar o modelo matemático da segunda Lei de Fick, com a devida comparação com os dados experimentais obtidos. A secagem foi realizada em filés de tainha submetidos à temperatura de 48 °C e à velocidade de deslocamento do ar de 2,5 m/s, no secador alternativo com convecção forçada e também em estufa comercial com convecção natural, realizando-se medições da massa do pescado a cada 15 minutos. Os resultados experimentais mostraram que a desidratação do filé de tainha foi mais rápida no secador alternativo em comparação com o processo em estufa comercial. Um ajuste do coeficiente de difusividade efetiva resultou na faixa de 2.10-10 a 2.7.10-10 m2/s para os filés de tainha avaliados e erro relativo máximo de 5% entre os resultados numéricos e os dados experimentais. Os modelos empíricos de polinômios de quarto grau e logaritmo tiveram

  11. Estudo Numérico e Experimental da Evolução Microestrutural e das Propriedades de Juntas Soldadas de Vergalhões pelo Processo GMAW

    Directory of Open Access Journals (Sweden)

    Rudineli Demarque

    2015-12-01

    Full Text Available Resumo Este trabalho constitui um estudo dos vergalhões CA-50 da classe dos aços SAE 1026. Para um melhor controle das propriedades mecânicas da junta soldada foi realizado este estudo, o conhecimento de certas variáveis é de grande importância para encontrar os parâmetros ideais de soldagem, e os respectivos resultados microestruturais e consequentemente sobre as propriedades mecânicas da junta soldada. Para realização deste estudo foi realizado um estudo do material como recebido para a fixação de uma base sólida de comparação. Foi realizada a soldagem do material utilizando como gás de proteção argônio com 20% de dióxido de carbono, o arame utilizado foi o cobreado ER70S-6, as juntas soldadas foram do tipo transpasse com monitoramento de temperatura através de termopares para dois aportes térmicos distintos. Um código numérico computacional foi desenvolvido para simular os fenômenos que ocorrem no processo (gradiente de temperatura, transformações de fases, transferência de calor. As juntas soldadas não apresentaram martensita como fase frágil, o metal de solda apresentou estrutura dendrítica, a ZTA apresentou duas regiões distintas com tamanhos de grão diferentes tudo isso devido ao gradiente de temperatura, que também originou características distintas do cordão de solda, ZTA, fases formadas e tamanhos de grão distintos.

  12. Experimental Validation of a Dynamic Model for Lightweight Robots

    Directory of Open Access Journals (Sweden)

    Alessandro Gasparetto

    2013-03-01

    Full Text Available Nowadays, one of the main topics in robotics research is dynamic performance improvement by means of a lightening of the overall system structure. The effective motion and control of these lightweight robotic systems occurs with the use of suitable motion planning and control process. In order to do so, model-based approaches can be adopted by exploiting accurate dynamic models that take into account the inertial and elastic terms that are usually neglected in a heavy rigid link configuration. In this paper, an effective method for modelling spatial lightweight industrial robots based on an Equivalent Rigid Link System approach is considered from an experimental validation perspective. A dynamic simulator implementing the formulation is used and an experimental test-bench is set-up. Experimental tests are carried out with a benchmark L-shape mechanism.

  13. A systematic review of animal models for experimental neuroma.

    Science.gov (United States)

    Toia, Francesca; Giesen, Thomas; Giovanoli, Pietro; Calcagni, Maurizio

    2015-10-01

    Peripheral neuromas can result in an unbearable neuropathic pain and functional impairment. Their treatment is still challenging, and their optimal management is to be defined. Experimental research still plays a major role, but - although numerous neuroma models have been proposed on different animals - there is still no single model recognised as being the reference. Several models show advantages over the others in specific aspects of neuroma physiopathology, prevention or treatment, making it unlikely that a single model could be of reference. A reproducible and standardised model of peripheral neuroma would allow better comparison of results from different studies. We present a systematic review of the literature on experimental in vivo models, analysing advantages and disadvantages, specific features and indications, with the goal of providing suggestions to help their standardisation. Published models greatly differ in the animal and the nerve employed, the mechanisms of nerve injury and the evaluation methods. Specific experimental models exist for terminal neuromas and neuromas in continuity (NIC). The rat is the most widely employed animal, the rabbit being the second most popular model. NIC models are more actively researched, but it is more difficult to generate such studies in a reproducible manner. Nerve transection is considered the best method to cause terminal neuromas, whereas partial transection is the best method to cause NIC. Traditional histomorphology is the historical gold-standard evaluation method, but immunolabelling, reverse transcriptase-polymerase chain reaction (RT-PCR) and proteomics are gaining increasing popularity. Computerised gait analysis is the gold standard for motor-recovery evaluation, whereas mechanical testing of allodynia and hyperalgesia reproducibly assesses sensory recovery. This review summarises current knowledge on experimental neuroma models, and it provides a useful tool for defining experimental protocols

  14. Influência da cola Bioglue® na deiscência de anastomose colônica: estudo experimental Influence of Bioglue® surgical adhesive on colonic anastomosis dehiscence: experimental study

    Directory of Open Access Journals (Sweden)

    Maurilio Toscano de Lucena

    2007-06-01

    Full Text Available A grande parte da morbimortalidade associada com a cirurgia colorretal, é associada com a deiscência anastomótica. Trabalhos experimentais sobre a utilidade de adesivos tissulares nas anastomoses colônicas são controversos, assim como estudos clínicos prospectivos randomizados são ausentes. O adesivo cirúrgico BioGlue®, formado por dois componentes - albumina sérica bovina purificada e glutaraldeído, forma uma ligação co-valente entre esses dois componentes e as proteínas teciduais no local de aplicação. O objetivo do estudo é avaliar a eficácia da BioGlue® na prevenção da deiscência anastomótica colônica em ratos. Foram utilizados 30 ratos machos da raça Wistar albino. A anastomose colocolônica foi confeccionada com sutura em pontos separados com polipropileno 5-0 (grupo 1 e aplicação da cola BioGlue® envolvendo a anastomose (grupo 2. Avaliaram-se a formação e extensão das aderências, a pressão de ruptura nas anastomoses e as alterações histológicas. Apenas um animal do grupo 1 (7% faleceu, sendo constatada na necropsia, obstrução intestinal com grande distensão de alças. A mortalidade no grupo 2, por outro lado, foi de 10 animais (67%, sendo observado: distensão de alças intestinais, vazamento anastomótico e, em algumas situações, franca peritonite fecal por deiscência quase que total da anastomose. O presente trabalho nos permitiu concluir que, o uso da Bioglue® nas anastomoses colônicas realizadas em ratos, promoveu um aumento na morbimortalidade que foi estatisticamente significante comparado à sutura convencional.The great part of the morbimortality associated with the colorretal surgery, is related with the anastomotic dehiscence. Experimental trials on the utility of tissue adhesives in the colonic anastomosis are controversial, as well as prospective randomized clinical studies are absent. BioGlue® Surgical Adhesive(BSA is a two-component surgical adhesive composed of purified bovine

  15. Hand-sewn and stapled esophageal anastomosis: experimental study in dogs Anastomose esofágica manual e mecânica: estudo experimental em cães

    Directory of Open Access Journals (Sweden)

    Cervantes Caporossi

    2004-08-01

    Full Text Available PURPOSE: To compare experimentally, the healing of cervical oesophageal anastomoses performed either with stapler or 2-layer hand-sewn sutures. METHODS: Thirty six dogs were randomised to two groups: stapled anastomoses (n = 18; hand-sewn anastomoses (n = 18. Each group was divided into three subgroups, corresponding to the day of sacrifice (3rd, 7th and 14th postoperative day. Healing was assessed by: a anatopathology b anastomotic resistance to bursting pressure test; c quantification of hidroxyproline RESULTS: Group 1 heal by second intention, group 2 showed a healing by first intention. Bursting pressure was similar between groups at day 3, though group 1 animals showed it significantly higher at day 7and day 14 compared with group 2. Statiscally, there were no interaction between the day of sacrifice and groups, as well as there was no difference among the dates of observation regarding the results of hidroxyproline CONCLUSIONS: a mechanical suture is more resistant than hand-sewn; b In stapler anastomoses, healing was as secondary union, whereas in hand-sewn anastomoses, healing was by first intention; c no correlation was found in the results of bursting pressure and hidroxyproline quantification.OBJETIVO: Comparar o processo de cicatrização do esôfago cervical com sutura mecânica ou manual em dois planos. MÉTODOS: Foram utilizados 36 cães, distribuídos em dois grupos: com sutura mecânica (n = 18, e manual (n = 18. Cada grupo foi dividido em três subgrupos, que correspondiam ao dia do sacrifício (3º p o; 7º p o e 14º p o. Avaliou-se: a o estudo anatomopatológico; b a resistência da anastomose à pressão interna; e c a dosagem da hidroxiprolina na anastomose. No estudo anatomopatológico, o grupo 1 apresentou cicatrização por segunda intenção, o grupo 2 apresentou cicatrização em primeira intenção. RESULTADOS: Os resultados da pressão de ruptura foram semelhantes em ambos os grupos no 3º p o; porém, o grupo 1

  16. Experimental modeling of injectivity loss; Modelagem experimental da perda de injetividade

    Energy Technology Data Exchange (ETDEWEB)

    Bonato, Adriano Jose do Amaral Mello; Silva, Pedro Glauto de Farias e; Gomes, Vanessa Limeira Azevedo; Santos, Adriano dos [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-07-01

    Produced water reinjection, suspended particles are retained in the porous media causing formation damage and injectivity decline. In general the retention of the particles occurs near the side of injection, this fact occurs in most cases, due to the size exclusion. The modeling of filtration and the consequent formation damage is essential to the project management of water injection in oil reservoirs. Thus, mathematical models are studied to better predict the distribution of particles throughout the porous media and determine the parameters of adjustment to injectivity decline. Among these models, there is the classic model which consists in determining these parameters (coefficient of filtration and formation damage). The methodology used in modeling is given from the equations the mass conservation, kinetic particle retention, the modified Darcy equation and the function formation damage. This study aimed to improve experimental modeling, including development of software for acquisition and processing of experimental data, considering the variable number of pressure measurements along the sample. The software was developed using the Labview 2011 platform and allows the determination of relevant parameters to predict injectivity loss in water injection wells. Furthermore, based on the traditional model of filtration in porous media (including depth filtration and formation of the external plaster), the software was applied to predict injectivity loss in addition to the properties of the grout. Finally, the classical models for transporting suspensions and damage to the formation were observed. (author)

  17. Efeito da tadalafila na prevenção de alterações do corpo cavernoso após lesão vasculo-nervosa do feixe peri prostático: estudo experimental em ratos

    OpenAIRE

    Toledo, Antonio Carlos Tonelli de [UNESP

    2013-01-01

    O presente estudo tem como objetivo avaliar o impacto no corpo cavernoso causado pela lesão isolada do nervo e artéria cavernosa, assim como determinar o efeito da tadalafila (IPDE-5) na remodelação tecidual, utilizando um modelo experimental de ratos. 50 ratos machos, da raça Whistar, pesando entre 250 e 350 gramas, foram aleatoriamente divididos, de forma randomizada em cinco grupos. Grupo 1 (G1): controle cirúrgico - CCir (n=10), submetidos apenas a exposição do feixe vásculo nervoso peri ...

  18. Contact Modelling in Resistance Welding, Part II: Experimental Validation

    DEFF Research Database (Denmark)

    Song, Quanfeng; Zhang, Wenqi; Bay, Niels

    2006-01-01

    Contact algorithms in resistance welding presented in the previous paper are experimentally validated in the present paper. In order to verify the mechanical contact algorithm, two types of experiments, i.e. sandwich upsetting of circular, cylindrical specimens and compression tests of discs...... with a solid ring projection towards a flat ring, are carried out at room temperature. The complete algorithm, involving not only the mechanical model but also the thermal and electrical models, is validated by projection welding experiments. The experimental results are in satisfactory agreement...... with the simulation prediction, showing the validity of the algorithm....

  19. Efeitos do ultrassom terapêutico em modelo experimental de ciatalgia Therapeutic ultrasound effects in a sciatica experimental model

    Directory of Open Access Journals (Sweden)

    Adriano Policam Ciena

    2009-12-01

    Full Text Available A ciática possui grande prevalência geral e seu tratamento tende a resolver as causas de compressão nervosa. A fisioterapia objetiva reduzir os sintomas causados pela compressão. O presente estudo teve como objetivo avaliar a eficácia do ultrassom terapêutico sobre a dor, em animais submetidos a modelo experimental de ciatalgia. Foram usados 18 ratos neste estudo, divididos em três grupos: GS (n = 4, submetido a modelo de ciatalgia e tratados com ultrassom desligado; GUP (n = 7, submetido à ciatalgia e tratados com ultrassom pulsado 2W/cm² (SATP; 0,4 - SATA; e grupo GUC (n = 7, submetido à ciática e ultrassom contínuo (0,4W/cm². O nervo ciático do membro posterior direito foi exposto à compressão com fio categute em quatro pontos. No 3º dia pós-operatório (PO, iniciou-se tratamento indireto por quatro dias. No 9º dia PO, o tratamento direto começou sobre a área do procedimento cirúrgico, por cinco dias consecutivos. O tempo de elevação da pata, durante a marcha, foi avaliado antes e após a ciatalgia, no 3º, 6º, 9º e 13º PO. Os resultados demonstraram que a aplicação do ultrassom reduziu a dor com ambos os tratamentos efetivos e tendeu a ser mais eficaz na forma pulsada.The sciatica possesses great general population prevalence, and its treatment tends to solve the nervous compression causes. Physiotherapy aims to reduce the symptoms caused by compression. This study aimed to evaluate the effectiveness of therapeutic ultrasound on pain in animals subjected to sciatica experimental model. Eighteen rats were used and they were divided in 3 groups: group SG (n=4 submitted to the sciatica and treated with the ultrasound off, group PUG (n=7 submitted to the sciatica and treated with pulsed ultrasound 2 W/cm² (SATP; 0,4 - SATA and group CUG (n=7 submitted to the sciatica and treated with continuous ultrasound (0,4 W/cm². The sciatic nerve of the posterior right limb was exposed to the compression with Catgut wire in 4

  20. Equilibrium phase experimental determination of petroleum + gas systems at supercritical condition using ultrasonic technology; Estudo experimental do equilibrio de fases de sistemas de fracoes de petroleo e gases em condicoes supercriticas utilizando tecnicas de ultra-som: aparato experimental

    Energy Technology Data Exchange (ETDEWEB)

    Mehl, Ana; Pessoa, Fernando L.P.; Silva, Silvia M.C. da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Feiteira, Jose F. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Escola de Engenharia

    2008-07-01

    In separation process of multicomponent systems based on phase equilibrium is essential know the phase behavior and the critical points of the system for determination and optimization of the operational conditions. The experimental apparatus presents the challenge of determine the equilibrium phase dates of a system composed by petroleum residua and supercritical solvent. The used method, named acoustic method, allows the composition identification of the phases in equilibrium also in cloudy systems as they are the systems formed by residues of crude oil. For this reason, the acoustic methodology, based on the ultra-sound technology will be used in the study of the phase equilibrium and experimental characterization of the system, in benches scale, operating in severe conditions of temperature and pressure.The acoustic method is one not invasive and not subjective technique, what becomes the work in high pressures safer. (author)

  1. Team Modelling: Review of Experimental Scenarios and Computational Models

    Science.gov (United States)

    2006-09-01

    designed to be) Yes Yes No Yes (Model individuals, or sub-teams - groups of individuals.) 19 C3TRACE* (Command, Control, and Communicatio ...radar sensors, satellites, c2 structures, jammers, communicatio ns networks and devices, and fire support) Depends (EADSIM normally models at

  2. Instrumental and ethical aspects of experimental research with animal models

    Directory of Open Access Journals (Sweden)

    Mirian Watanabe

    2014-02-01

    Full Text Available Experimental animal models offer possibilities of physiology knowledge, pathogenesis of disease and action of drugs that are directly related to quality nursing care. This integrative review describes the current state of the instrumental and ethical aspects of experimental research with animal models, including the main recommendations of ethics committees that focus on animal welfare and raises questions about the impact of their findings in nursing care. Data show that, in Brazil, the progress in ethics for the use of animals for scientific purposes was consolidated with Law No. 11.794/2008 establishing ethical procedures, attending health, genetic and experimental parameters. The application of ethics in handling of animals for scientific and educational purposes and obtaining consistent and quality data brings unquestionable contributions to the nurse, as they offer subsidies to relate pathophysiological mechanisms and the clinical aspect on the patient.

  3. Modeling and experimentation of a positioning system of SMA wires

    Science.gov (United States)

    Lei, KinFong; Yam, Yeung

    2000-06-01

    This work reports two modeling and control attempts performed on a positioning system comprising of linking SMA wires and an overlooking video system for on-line measurements. The first attempt takes the model by Ikuta and identifies experimentally the parameters of the SMA wire. The identified single wire model is then extended to a system of two SMA wires joining together at their tips, based upon which open loop position control of the linkage is then conducted. The approach, however, becomes too complicated when more SMA wires are involved. The second attempt utilizes a neuro-fuzzy based approach for positioning control of a linkage point joining together four SMA wires. The second approach involves four ANFIS neuro-networks with hybrid learning algorithm trained to model the currents to the SMA wires as functions of present and target positions of the linkage point. Experimentation for both the two-wires and four-wires system yield quite satisfactory performance.

  4. Experimental bounds on collapse models from gravitational wave detectors

    Science.gov (United States)

    Carlesso, Matteo; Bassi, Angelo; Falferi, Paolo; Vinante, Andrea

    2016-12-01

    Wave function collapse models postulate a fundamental breakdown of the quantum superposition principle at the macroscale. Therefore, experimental tests of collapse models are also fundamental tests of quantum mechanics. Here, we compute the upper bounds on the collapse parameters, which can be inferred by the gravitational wave detectors LIGO, LISA Pathfinder, and AURIGA. We consider the most widely used collapse model, the continuous spontaneous localization (CSL) model. We show that these experiments exclude a huge portion of the CSL parameter space, the strongest bound being set by the recently launched space mission LISA Pathfinder. We also rule out a proposal for quantum-gravity-induced decoherence.

  5. Experimental model in rat for sentinel node biopsy

    Directory of Open Access Journals (Sweden)

    Oliveira Filho Renato Santos de

    2003-01-01

    Full Text Available Although sentinel node procedure has been used world wide, there are many aspects to be defined and better standardized. This study address if the experimental model in rats is appropriate for sentinel node biopsy. In this model, the lymph nodes are showed by lymphoscintigraphy, they are dyed by patent blue and identified by intraoperative gamma probe detection. It isn?t necessary to use magnification for the procedure. The model demonstrated that sentinel node biopsy in rats is feasible. So, besides allowing researches in this field, the model is useful for training and diffusing this technique.

  6. Experimental Analysis and Model Validation of an Opaque Ventilated Facade

    DEFF Research Database (Denmark)

    López, F. Peci; Jensen, Rasmus Lund; Heiselberg, Per

    2012-01-01

    Natural ventilation is a convenient way of reducing energy consumption in buildings. In this study an experimental module of an opaque ventilated façade (OVF) was built and tested for assessing its potential of supplying free ventilation and air preheating for the building. A numerical model was ...

  7. Experimental model of capsular contracture in silicone implants

    Directory of Open Access Journals (Sweden)

    Bastos Érika Malheiros

    2003-01-01

    Full Text Available The breast implant procedure is one of the most performed into Plastic Surgery and the contracture that occurs the capsule formed around the breast implants one of most frequent complication. We describe here one experimental model of capsule contracture in rats.

  8. Sciara as an experimental model for studies on the evolutionary ...

    Indian Academy of Sciences (India)

    Sciara as an experimental model for studies on the evolutionary relationships between the zygotic, maternal and environmental primary signals for sexual development. Lucas Sánchez. Review Article Volume ... Lucas Sánchez1. Centro de Investigaciones Biol´ogicas (C. S. I. C.), Ramiro de Maeztu 9, 28040 Madrid, Spain ...

  9. Novel sensors for food inspection modelling, fabrication and experimentation

    CERN Document Server

    Abdul Rahman, Mohd Syaifudin; Yu, Pak-Lam

    2014-01-01

    This book addresses presents recent developments of novel planar interdigital sensors for food inspection. It covers the fundamentals of sensors, their design, modelling and simulations, fabrications, characterizations, experimental investigations and analyses. This book will be useful for the engineers and researchers especially higher undergraduate, postgraduate students as well as practitioners working on the development of Electromagnetic Sensors.

  10. numerical and numerical and experimental modeling of the static

    African Journals Online (AJOL)

    eobe

    recommendation for subsequent experiments and analysis of these types of structural elements. In this paper a report of numerical and experimental modeling of the static response of thin-walled reinforced concrete box girder bridges is given. The work is executed to verify the validity of a software developed by the authors ...

  11. An Interactive Multimedia Based Instruction in Experimental Modelling

    DEFF Research Database (Denmark)

    Knudsen, Morten; Nielsen, J.N.; Østergaard, J.

    1997-01-01

    A CD-ROM based interactive multimedia instruction in experimental modelling for Danish Engineering School teachers is described. The content is based on a new sensitivity approach for direct estimation of physical parameters in linear and nonlinear dynamic systems. The presentation is inspired...

  12. Pruning Chinese trees : an experimental and modelling approach

    NARCIS (Netherlands)

    Zeng, Bo

    2001-01-01

    Pruning of trees, in which some branches are removed from the lower crown of a tree, has been extensively used in China in silvicultural management for many purposes. With an experimental and modelling approach, the effects of pruning on tree growth and on the harvest of plant material were studied.

  13. [Establishment and evaluation of experimental sepsis mouse model].

    Science.gov (United States)

    Wang, Li-Yan; Xu, Ruo-Nan; Han, Gen-Cheng; Wang, Ren-Xi; Chen, Guo-Jiang; Xiao, He; Hou, Chun-Mei; Shen, Bei-Fen; Li, Yan

    2010-06-01

    After treating with chemotherapy or immunosuppressant, malignant diseases of hematopoietic system such as leukemia, malignant lymphoma and aplastic anemia usually induced severe infection such as sepsis. Sepsis which is hard to be diagnosed causes high death rate. This study was purposed to establish an experimental sepsis mouse model so as to provide a basis for pathogenesis and intervention study. A classic caecal ligation and puncture (CLP) was used to establish experimental sepsis model. ELISA was used to detect levels of C5a, IL-6, TNFalpha, and IFN-gamma. Flow Cytometry was applied to measure apoptosis of lymphocytes in thymus and mesentery. The pathologic changes of thymus and spleen were confirmed by HE staining. The results showed that almost 70%-80% mice died at 72 hours after CLP. Only approximate 20% animal survived during finite time, mice in CLP group had significant weight lose. Meanwhile large release of different inflammatory mediators which are related with sepsis (C5a, IL-6, TNF-alpha, and IFN-gamma) was observed after CLP. Apoptosis of lymphocytes in thymus and mesentery lymphonodus was enhanced markedly after CLP. Significantly pathologic injury was also observed in thymus and spleen. It is concluded that a mouse model of experimental sepsis was successfully established by caecal ligation and puncture which can well mimic the clinical symptom of sepsis. The experimental sepsis mouse model provides an excellent tool for exploring the pathogenesis and intervention ways for sepsis accompanied with complicated malignant hematological diseases in vivo.

  14. Caracterização de um modelo experimental de Diabetes Mellitus, induzido pela aloxana em ratos: estudo clínico e laboratorial

    Directory of Open Access Journals (Sweden)

    Lerco Mauro Masson

    2003-01-01

    Full Text Available OBJETIVO: O presente estudo teve por objetivo caracterizar as alterações clínicas e laboratoriais do rato portador de Diabetes Mellitus induzido pela administração endovenosa de aloxana. MÉTODOS: Os animais foram distribuídos, por sorteio, em dois grupos experimentais: Grupo Controle Normal (G1, constituído de 25 animais sadios, e Grupo Diabético (G2, formado por 25 animais diabéticos graves, que foram avaliados em cinco momentos (1, 3, 6, 9 e 12 meses de seguimento, tendo sido estudados os seguintes parâmetros: evolução clínica (peso, ingestão hídrica, ingestão alimentar e diurese e exames bioquímicos (glicemia de jejum, glicose urinária, glicosúria, cetonúria, colesterol total, colesterol HDL, triglicérides e lipídios. RESULTADOS: A injeção de aloxana 2% na via endovenosa do rato acompanhou-se de um índice de mortalidade de 39%, tendo produzido diabetes grave também em 39% dos animais. O diabetes foi caracterizado por queda progressiva do peso corporal, elevação substancial da ingestão hídrica, ingestão alimentar e da diurese, com valores glicêmicos acima de 300 mg/dl, glicosúria 3+ e, eventualmente, cetonúria. O diabetes não altera o perfil de colesterol e lípides de ratos a longo prazo. CONCLUSÃO: Nossos estudos revelam que a aloxana produz, no rato, alterações clínicas e laboratoriais características de diabetes grave, as quais possibilitam estudos a longo prazo do diabetes.

  15. Aspectos do envelhecimento cerebral e função cognitiva em modelo experimental animal e estudo de mecanismos de neurodegeneração em cultura celular

    OpenAIRE

    Ieda de Fatima Oliveira Silva

    2007-01-01

    Os dois fenômenos, biológico e comportamental, abordados no presente trabalho são, envelhecimento cerebral e memória espacial. Vários estudos, comparativos e experimentais, têm mostrado que sujeitos idosos apresentam desempenho significativamente prejudicado em diferentes tipos de tarefas cognitivas. Sabe-se também que, existem contradições na literatura com relação às conseqüências da interação entre os efeitos do envelhecimento com os efeitos do consumo crônico de etanol e da restrição alim...

  16. Systematic integration of experimental data and models in systems biology

    Directory of Open Access Journals (Sweden)

    Simeonidis Evangelos

    2010-11-01

    Full Text Available Abstract Background The behaviour of biological systems can be deduced from their mathematical models. However, multiple sources of data in diverse forms are required in the construction of a model in order to define its components and their biochemical reactions, and corresponding parameters. Automating the assembly and use of systems biology models is dependent upon data integration processes involving the interoperation of data and analytical resources. Results Taverna workflows have been developed for the automated assembly of quantitative parameterised metabolic networks in the Systems Biology Markup Language (SBML. A SBML model is built in a systematic fashion by the workflows which starts with the construction of a qualitative network using data from a MIRIAM-compliant genome-scale model of yeast metabolism. This is followed by parameterisation of the SBML model with experimental data from two repositories, the SABIO-RK enzyme kinetics database and a database of quantitative experimental results. The models are then calibrated and simulated in workflows that call out to COPASIWS, the web service interface to the COPASI software application for analysing biochemical networks. These systems biology workflows were evaluated for their ability to construct a parameterised model of yeast glycolysis. Conclusions Distributed information about metabolic reactions that have been described to MIRIAM standards enables the automated assembly of quantitative systems biology models of metabolic networks based on user-defined criteria. Such data integration processes can be implemented as Taverna workflows to provide a rapid overview of the components and their relationships within a biochemical system.

  17. Theories linguistiques, modeles informatiques, experimentation psycholinguistique (Linguistic Theories, Information-Processing Models, Psycholinguistic Experimentation)

    Science.gov (United States)

    Dubois, Daniele

    1975-01-01

    Delineates and elaborates upon the underlying psychological postulates in linguistic and information-processing models, and shows the interdependence of psycholinguistics and linguistic analysis. (Text is in French.) (DB)

  18. Optimization of Regression Models of Experimental Data Using Confirmation Points

    Science.gov (United States)

    Ulbrich, N.

    2010-01-01

    A new search metric is discussed that may be used to better assess the predictive capability of different math term combinations during the optimization of a regression model of experimental data. The new search metric can be determined for each tested math term combination if the given experimental data set is split into two subsets. The first subset consists of data points that are only used to determine the coefficients of the regression model. The second subset consists of confirmation points that are exclusively used to test the regression model. The new search metric value is assigned after comparing two values that describe the quality of the fit of each subset. The first value is the standard deviation of the PRESS residuals of the data points. The second value is the standard deviation of the response residuals of the confirmation points. The greater of the two values is used as the new search metric value. This choice guarantees that both standard deviations are always less or equal to the value that is used during the optimization. Experimental data from the calibration of a wind tunnel strain-gage balance is used to illustrate the application of the new search metric. The new search metric ultimately generates an optimized regression model that was already tested at regression model independent confirmation points before it is ever used to predict an unknown response from a set of regressors.

  19. Thermal conductivity of microporous layers: Analytical modeling and experimental validation

    Science.gov (United States)

    Andisheh-Tadbir, Mehdi; Kjeang, Erik; Bahrami, Majid

    2015-11-01

    A new compact relationship is developed for the thermal conductivity of the microporous layer (MPL) used in polymer electrolyte fuel cells as a function of pore size distribution, porosity, and compression pressure. The proposed model is successfully validated against experimental data obtained from a transient plane source thermal constants analyzer. The thermal conductivities of carbon paper samples with and without MPL were measured as a function of load (1-6 bars) and the MPL thermal conductivity was found between 0.13 and 0.17 W m-1 K-1. The proposed analytical model predicts the experimental thermal conductivities within 5%. A correlation generated from the analytical model was used in a multi objective genetic algorithm to predict the pore size distribution and porosity for an MPL with optimized thermal conductivity and mass diffusivity. The results suggest that an optimized MPL, in terms of heat and mass transfer coefficients, has an average pore size of 122 nm and 63% porosity.

  20. A systematic review of prion therapeutics in experimental models.

    Science.gov (United States)

    Trevitt, Clare R; Collinge, John

    2006-09-01

    Prion diseases are transmissible, invariably fatal, neurodegenerative diseases which include Creutzfeldt-Jakob disease (CJD) in humans and bovine spongiform encephalopathy and scrapie in animals. A large number of putative treatments have been studied in experimental models over the past 30 years, with at best modest disease-modifying effects. The arrival of variant CJD in the UK in the 1990s has intensified the search for effective therapeutic agents, using an increasing number of animal, cellular and in vitro models with some recent promising proof of principle studies. Here, for the first time, we present a comprehensive systematic, rather than selective, review of published data on experimental approaches to prion therapeutics to provide a scientific resource for informing future therapeutics research, both in laboratory models and in clinical studies.

  1. Experimental validation of the multiphase extended Leblond's model

    Science.gov (United States)

    Weisz-Patrault, Daniel

    2017-10-01

    Transformation induced plasticity is a crucial contribution of the simulation of several forming processes involving phase transitions under mechanical loads, resulting in large irreversible strain even though the applied stress is under the yield stress. One of the most elegant and widely used models is based on analytic homogenization procedures and has been proposed by Leblond et al. [1-4]. Very recently, a simple extension of the Leblond's model has been developed by Weisz-Patrault [8]. Several product phases are taken into account and several assumptions are relaxed in order to extend the applicability of the model. The present contribution compares experimental tests with numerical computations, in order to discuss the validity of the developed theory. Thus, experimental results extracted from the existing literature are analyzed. Results show a good agreement between measurements and theoretical computations.

  2. Regression Model Optimization for the Analysis of Experimental Data

    Science.gov (United States)

    Ulbrich, N.

    2009-01-01

    A candidate math model search algorithm was developed at Ames Research Center that determines a recommended math model for the multivariate regression analysis of experimental data. The search algorithm is applicable to classical regression analysis problems as well as wind tunnel strain gage balance calibration analysis applications. The algorithm compares the predictive capability of different regression models using the standard deviation of the PRESS residuals of the responses as a search metric. This search metric is minimized during the search. Singular value decomposition is used during the search to reject math models that lead to a singular solution of the regression analysis problem. Two threshold dependent constraints are also applied. The first constraint rejects math models with insignificant terms. The second constraint rejects math models with near-linear dependencies between terms. The math term hierarchy rule may also be applied as an optional constraint during or after the candidate math model search. The final term selection of the recommended math model depends on the regressor and response values of the data set, the user s function class combination choice, the user s constraint selections, and the result of the search metric minimization. A frequently used regression analysis example from the literature is used to illustrate the application of the search algorithm to experimental data.

  3. Atividade Experimental como Proposta de Formação de Aprendizagem Significativa no Tópico de Estudo de Soluções no Ensino Médio

    Directory of Open Access Journals (Sweden)

    Francisco Alberto Saraiva

    2017-05-01

    Full Text Available Como parte da dissertação em Ensino de Ciências e Matemática (ECM, o presente artigo investiga especificamente, indícios de Aprendizagem Significativa (AS no ensino e aprendizagem em Química no tópico Estudo de Soluções (ES adotando Atividade Experimental (AE. Para coleta de dados, foram aplicadas questões após as aulas teóricas e atividade experimental a estudantes do 2° ano do Ensino Médio de uma escola pública do Ceará. A análise dos dados leva a concluir que a AE, na abordagem do tópico de ES, contribui para aprendizagem significativa, pois os estudantes apresentaram evolução em suas respostas.

  4. Dynamic Modeling of Wind Turbine Gearboxes and Experimental Validation

    DEFF Research Database (Denmark)

    Pedersen, Rune

    is presented. The model takes into account the effects of load and applied grinding corrections. The results are verified by comparing to simulated and experimental results reported in the existing literature. Using gear data loosely based on a 1 MW wind turbine gearbox, the gear mesh stiffness is expanded...... analysis in relation to gear dynamics. A multibody model of two complete 2.3MWwind turbine gearboxes mounted back-to-back in a test rig is built. The mean values of the proposed gear mesh stiffnesses are included. The model is validated by comparing with calculated and measured eigenfrequencies and mode...

  5. Experimental validation of a Bayesian model of visual acuity.

    LENUS (Irish Health Repository)

    Dalimier, Eugénie

    2009-01-01

    Based on standard procedures used in optometry clinics, we compare measurements of visual acuity for 10 subjects (11 eyes tested) in the presence of natural ocular aberrations and different degrees of induced defocus, with the predictions given by a Bayesian model customized with aberrometric data of the eye. The absolute predictions of the model, without any adjustment, show good agreement with the experimental data, in terms of correlation and absolute error. The efficiency of the model is discussed in comparison with image quality metrics and other customized visual process models. An analysis of the importance and customization of each stage of the model is also given; it stresses the potential high predictive power from precise modeling of ocular and neural transfer functions.

  6. Endogenous opioid antagonism in physiological experimental pain models

    DEFF Research Database (Denmark)

    Werner, Mads U; Pereira, Manuel P; Andersen, Lars Peter H

    2015-01-01

    Opioid antagonists are pharmacological tools applied as an indirect measure to detect activation of the endogenous opioid system (EOS) in experimental pain models. The objective of this systematic review was to examine the effect of mu-opioid-receptor (MOR) antagonists in placebo-controlled, double...... hyperalgesia models (6 studies), 'pain' models (25 studies), summation models (2 studies), nociceptive reflex models (3 studies) and miscellaneous models (2 studies). A consistent reversal of analgesia by a MOR-antagonist was demonstrated in 10 of the 25 ITP-studies, including stress-induced analgesia and r......TMS. In the remaining 14 conditioning modulation studies either absence of effects or ambiguous effects by MOR-antagonists, were observed. In the STP-studies, no effect of the opioid-blockade could be demonstrated in 5 out of 6 secondary hyperalgesia studies. The direction of MOR-antagonist dependent effects upon pain...

  7. Experimental-analytical method of technological processes modeling in education

    Directory of Open Access Journals (Sweden)

    Efremov German I.

    2016-01-01

    Full Text Available The article considers general modeling techniques used in the study in education at different stages. The classification of different types of models and main stages of the simulation are considered. It is shown that in the course “Process of simulation” for technical areas of the Universities required the category of “Experimental-analytical simulation method”. For example, a new textbook for bachelors “Modeling of chemical-technological processes” shows that the section facilitates the compilation of process models in general; gives the possibility of studying the process at different levels; describes the nonlinear properties of the simulation objects, and to obtain refined adjustment of the model according to the experiment. The use of models of high accuracy can improve the quality of education.

  8. Experimental Evaluation of Equivalent-Fluid Models for Melamine Foam

    Science.gov (United States)

    Allen, Albert R.; Schiller, Noah H.

    2016-01-01

    Melamine foam is a soft porous material commonly used in noise control applications. Many models exist to represent porous materials at various levels of fidelity. This work focuses on rigid frame equivalent fluid models, which represent the foam as a fluid with a complex speed of sound and density. There are several empirical models available to determine these frequency dependent parameters based on an estimate of the material flow resistivity. Alternatively, these properties can be experimentally educed using an impedance tube setup. Since vibroacoustic models are generally sensitive to these properties, this paper assesses the accuracy of several empirical models relative to impedance tube measurements collected with melamine foam samples. Diffuse field sound absorption measurements collected using large test articles in a laboratory are also compared with absorption predictions determined using model-based and measured foam properties. Melamine foam slabs of various thicknesses are considered.

  9. Transvaginal ultrasound ovarian diathermy: sheep as an experimental model

    Directory of Open Access Journals (Sweden)

    Pimentel Anita M

    2012-01-01

    Full Text Available Abstract Background Some techniques of transvaginal ovarian drilling have been previously described. Nevertheless a monopolar transvaginal ovarian cauterization, that use the expertise and safety of transvaginal puncture for oocyte captation seems to be an easier and feasible approach. The aim of this study was to develop a minimally invasive ovarian cauterization technique under transvaginal ultrasound control, and to evaluate the safety of the transvaginal ovarian monopolar cauterization, female sheep at reproductive age were used as an experimental model. Findings An experimental study was performed in a university research center. Seventeen female sheep (15 Corriedale e 2 Suffolk in reproductive age were submitted to transvaginal ovarian cauterization with a monopolar Valleylab Force 2 electrocautery. Macroscopic and microscopic lesions were assessed. Ovarian size were 1.31 cm2 ± 0,43 (Corriedale and 3.41 cm2 ± 0,64 (Suffolk. From 30 ovaries from Corriedale sheep punctured, only 3 were cauterized, presenting macroscopic and typical microscopic lesion. In the Suffolk sheep group, only one ovary was cauterized. No lesion could be found in the needle path. Conclusions This is the first experimental animal model described for ovarian cauterization needle guided by transvaginal ultrasound. The sheep does not seem to be the ideal animal model to study this technique. Another animal model, whose ovaries are better identified by transvaginal ultrasound should be sought for this technique, theoretically less invasive, before it could be offered safely to women with polycystic ovary syndrome.

  10. Numerical modeling of experimental human fibrous cap delamination.

    Science.gov (United States)

    Leng, Xiaochang; Davis, Lindsey A; Deng, Xiaomin; Sutton, Michael A; Lessner, Susan M

    2016-06-01

    Fibrous cap delamination is a critical process during the rupture of atherosclerotic plaque, which often leads to severe life-threatening clinical consequences such as myocardial infarction or stroke. In this study a finite element modeling and simulation approach is presented that enables the study of fibrous cap delamination experiments for the purpose of understanding the fibrous cap delamination process. A cohesive zone model (CZM) approach is applied to simulate delamination of the fibrous cap from the underlying plaque tissue. A viscoelastic anisotropic (VA) model for the bulk arterial material behavior is extended from existing studies so that the hysteresis phenomenon observed in the fibrous cap delamination experiments can be captured. A finite element model is developed for the fibrous cap delamination experiments, in which arterial layers (including the fibrous cap and the underlying plaque tissue) are represented by solid elements based on the VA model and the fibrous cap-underlying plaque tissue interface is characterized by interfacial CZM elements. In the CZM, the delamination process is governed by an exponential traction-separation law which utilizes critical energy release rates obtained directly from the fibrous cap delamination experiments. A set of VA model parameter values and CZM parameter values is determined based on values suggested in the literature and through matching simulation predictions of the load vs. load-point displacement curve with one set of experimental measurements. Using this set of parameter values, simulation predictions for other sets of experimental measurements are obtained and good agreement between simulation predictions and experimental measurements is observed. Results of this study demonstrate the applicability of the viscoelastic anisotropic model and the CZM approach for the simulation of diseased arterial tissue failure processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Target Soil Impact Verification: Experimental Testing and Kayenta Constitutive Modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Broome, Scott Thomas [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Flint, Gregory Mark [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Dewers, Thomas [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Newell, Pania [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    This report details experimental testing and constitutive modeling of sandy soil deformation under quasi - static conditions. This is driven by the need to understand constitutive response of soil to target/component behavior upon impact . An experimental and constitutive modeling program was followed to determine elastic - plastic properties and a compressional failure envelope of dry soil . One hydrostatic, one unconfined compressive stress (UCS), nine axisymmetric compression (ACS) , and one uniaxial strain (US) test were conducted at room temperature . Elastic moduli, assuming isotropy, are determined from unload/reload loops and final unloading for all tests pre - failure and increase monotonically with mean stress. Very little modulus degradation was discernable from elastic results even when exposed to mean stresses above 200 MPa . The failure envelope and initial yield surface were determined from peak stresses and observed onset of plastic yielding from all test results. Soil elasto - plastic behavior is described using the Brannon et al. (2009) Kayenta constitutive model. As a validation exercise, the ACS - parameterized Kayenta model is used to predict response of the soil material under uniaxial strain loading. The resulting parameterized and validated Kayenta model is of high quality and suitable for modeling sandy soil deformation under a range of conditions, including that for impact prediction.

  12. Experimental Damage Identification of a Model Reticulated Shell

    Directory of Open Access Journals (Sweden)

    Jing Xu

    2017-04-01

    Full Text Available The damage identification of a reticulated shell is a challenging task, facing various difficulties, such as the large number of degrees of freedom (DOFs, the phenomenon of modal localization and transition, and low modeling accuracy. Based on structural vibration responses, the damage identification of a reticulated shell was studied. At first, the auto-regressive (AR time series model was established based on the acceleration responses of the reticulated shell. According to the changes in the coefficients of the AR model between the damaged conditions and the undamaged condition, the damage of the reticulated shell can be detected. In addition, the damage sensitive factors were determined based on the coefficients of the AR model. With the damage sensitive factors as the inputs and the damage positions as the outputs, back-propagation neural networks (BPNNs were then established and were trained using the Levenberg–Marquardt algorithm (L–M algorithm. The locations of the damages can be predicted by the back-propagation neural networks. At last, according to the experimental scheme of single-point excitation and multi-point responses, the impact experiments on a K6 shell model with a scale of 1/10 were conducted. The experimental results verified the efficiency of the proposed damage identification method based on the AR time series model and back-propagation neural networks. The proposed damage identification method can ensure the safety of the practical engineering to some extent.

  13. Estudo experimental da separação do fluxo bifasico em uma ramificação lateral tipo "T"

    OpenAIRE

    Juan Carlos Severiche Maldonado

    1999-01-01

    Resumo: o objetivo deste estudo é pesquisar experimentalmente a separação de um fluxo bifásico sob condições de padrão de fluxo estratificado ondulado e anular em uma junta "tê" horizontal de configuração regular e irregular. Os dados da separação foram adquiridos para uma extensa série de condições de fluxo estratificado ondulado e anular; os dados experimentais incluem medições de razões de separação gás-líquido e distribuição da pressão ao longo dos tres ramos. Analisando os dados se obser...

  14. Biomechanics of epithelial cell islands analyzed by modeling and experimentation

    CERN Document Server

    Coburn, Luke; Noppe, Adrian; Caldwell, Benjamin J; Moussa, Elliott; Yap, Chloe; Priya, Rashmi; Lobaskin, Vladimir; Roberts, Anthony P; Yap, Alpha S; Neufeld, Zoltan; Gomez, Guillermo A

    2016-01-01

    We generated a new computational approach to analyze the biomechanics of epithelial cell islands that combines both vertex and contact-inhibition-of-locomotion models to include both cell-cell and cell-substrate adhesion. Examination of the distribution of cell protrusions (adhesion to the substrate) in the model predicted high order profiles of cell organization that agree with those previously seen experimentally. Cells acquired an asymmetric distribution of protrusions (and traction forces) that decreased when moving from the edge to the island center. Our in silico analysis also showed that tension on cell-cell junctions (and monolayer stress) is not homogeneous across the island. Instead it is higher at the island center and scales up with island size, which we confirmed experimentally using laser ablation assays and immunofluorescence. Moreover, our approach has the minimal elements necessary to reproduce mechanical crosstalk between both cell-cell and cell substrate adhesion systems. We found that an i...

  15. Numerical modeling of nitrogen oxide emission and experimental verification

    Directory of Open Access Journals (Sweden)

    Szecowka Lech

    2003-12-01

    Full Text Available The results of nitrogen reduction in combustion process with application of primary method are presented in paper. The reduction of NOx emission, by the recirculation of combustion gasses, staging of fuel and of air was investigated, and than the reduction of NOx emission by simultaneous usage of the mentioned above primary method with pulsatory disturbances.The investigations contain numerical modeling of NOx reduction and experimental verification of obtained numerical calculation results.

  16. Epidural blood patch: A study on an experimental model

    OpenAIRE

    S K Sengupta

    2013-01-01

    Aim: Epidural blood patch has been used to treat spinal headache with varying success. An experimental model was designed to ascertain whether an epidural blood patch can be used to seal the needle puncture sites in dural repair. Materials and Methods: Bovine dura was secured to the lower end of an open-ended calibrated plastic cylinder. Multiple interrupted stitches were applied over a 02 cm length of the dura without any incision. The cylinder was filled with colored saline gradually with t...

  17. Experimental model of heterotopic ossification in Wistar rats

    Energy Technology Data Exchange (ETDEWEB)

    Zotz, T.G.G. [Escola Politécnica, Programa de Pós-Graduação em Tecnologia em Saúde, Pontifícia Universidade Católica do Paraná, Curitiba, PR (Brazil); Paula, J.B. de [Médico,Doutor em Engenharia Biomédica, Curitiba, PR (Brazil); Moser, A.D.L. [Escola Politécnica, Programa de Pós-Graduação em Tecnologia em Saúde, Pontifícia Universidade Católica do Paraná, Curitiba, PR (Brazil)

    2012-04-05

    Heterotopic ossification (HO) is a metaplastic biological process in which there is newly formed bone in soft tissues adjacent to large joints, resulting in joint mobility deficit. In order to determine which treatment techniques are more appropriate for such condition, experimental models of induced heterotopic bone formation have been proposed using heterologous demineralized bone matrix implants and bone morphogenetic protein and other tissues. The objective of the present experimental study was to identify a reliable protocol to induce HO in Wistar rats, based on autologous bone marrow (BM) implantation, comparing 3 different BM volumes and based on literature evidence of this HO induction model in larger laboratory animals. Twelve male Wistar albino rats weighing 350/390 g were used. The animals were anesthetized for blood sampling before HO induction in order to quantify serum alkaline phosphatase (ALP). HO was induced by BM implantation in both quadriceps muscles of these animals, experimental group (EG). Thirty-five days after the induction, another blood sample was collected for ALP determination. The results showed a weight gain in the EG and no significant difference in ALP levels when comparing the periods before and after induction. Qualitative histological analysis confirmed the occurrence of heterotopic ossification in all 12 EG rats. In conclusion, the HO induction model was effective when 0.35 mL autologous BM was applied to the quadriceps of Wistar rats.

  18. Amplified energy harvester from footsteps: design, modeling, and experimental analysis

    Science.gov (United States)

    Wang, Ya; Chen, Wusi; Guzman, Plinio; Zuo, Lei

    2014-04-01

    This paper presents the design, modeling and experimental analysis of an amplified footstep energy harvester. With the unique design of amplified piezoelectric stack harvester the kinetic energy generated by footsteps can be effectively captured and converted into usable DC power that could potentially be used to power many electric devices, such as smart phones, sensors, monitoring cameras, etc. This doormat-like energy harvester can be used in crowded places such as train stations, malls, concerts, airport escalator/elevator/stairs entrances, or anywhere large group of people walk. The harvested energy provides an alternative renewable green power to replace power requirement from grids, which run on highly polluting and global-warming-inducing fossil fuels. In this paper, two modeling approaches are compared to calculate power output. The first method is derived from the single degree of freedom (SDOF) constitutive equations, and then a correction factor is applied onto the resulting electromechanically coupled equations of motion. The second approach is to derive the coupled equations of motion with Hamilton's principle and the constitutive equations, and then formulate it with the finite element method (FEM). Experimental testing results are presented to validate modeling approaches. Simulation results from both approaches agree very well with experimental results where percentage errors are 2.09% for FEM and 4.31% for SDOF.

  19. Experimental model of cutaneous radiation injury in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Meirelles, Rafael Panisi de Campos [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina; Hochman, Bernardo [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina. Dept. de Cirurgia; Helene Junior, Americo; Fraga, Murillo Francisco Pires [Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo (FCMSCSP), SP (Brazil). Dept. de Cirurgia. Divisao de Cirurgia Plastica; Lellis, Rute [Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo (FCMSCSP), SP (Brazil). Divisao de Patologia; Ferreira, Lydia Masako, E-mail: rpcmeirelles@yahoo.com.br, E-mail: lydia.dcir@epm.br [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Mediciana. Divisao de Cirugia Plastica

    2013-07-01

    Purpose: to describe an experimental model of cutaneous radiation injury in rabbits. Methods: on this study eight six-month-old New Zealand male rabbits, with an average weight of 2.5kg were used. They were distributed in four groups (n=2 per group). The control group did not receive radiotherapy and the others received one radiotherapy session of 2000, 3000 and 4500 cGy, respectively. Photographic analysis and histopathological evaluation of the irradiated areas were carried out. Results: after 30 days, the animals from the control group had all their hair grown. In spite of that, the animals from group 2000 cGy had a 60-day alopecia and from group 3000 cGy, a 90-day alopecia. After the 30th day, the 3000cGy group demonstrated 90-day cutaneous radiation injuries, graded 3 and 4. One of the animals from group 4500 cGy died on the 7th day with visceral necrosis. The other from the same group had total skin necrosis. A progressive reduction of glands and blood vessels count and an increase on collagen deposition was observed. Conclusion: The proposed experimental model is reproducible. This study suggests that the dosage 4500cGy is excessive and the 3000 cGy is the most effective for this experimental model of cutaneous radiation injury in rabbits. (author)

  20. Ionospheric topside models compared with experimental electron density profiles

    Directory of Open Access Journals (Sweden)

    S. M. Radicella

    2005-06-01

    Full Text Available Recently an increasing number of topside electron density profiles has been made available to the scientific community on the Internet. These data are important for ionospheric modeling purposes, since the experimental information on the electron density above the ionosphere maximum of ionization is very scarce. The present work compares NeQuick and IRI models with the topside electron density profiles available in the databases of the ISIS2, IK19 and Cosmos 1809 satellites. Experimental electron content from the F2 peak up to satellite height and electron densities at fixed heights above the peak have been compared under a wide range of different conditions. The analysis performed points out the behavior of the models and the improvements needed to be assessed to have a better reproduction of the experimental results. NeQuick topside is a modified Epstein layer, with thickness parameter determined by an empirical relation. It appears that its performance is strongly affected by this parameter, indicating the need for improvements of its formulation. IRI topside is based on Booker's approach to consider two parts with constant height gradients. It appears that this formulation leads to an overestimation of the electron density in the upper part of the profiles, and overestimation of TEC.

  1. Estudo experimental do processo de rotomoldagem de PELBD: efeitos sobre a morfologia e estabilidade dimensional Experimental study of rotational molding process of LLDPE: effects on morphology and dimensional stability

    Directory of Open Access Journals (Sweden)

    Tiago Boni Comisso

    2013-01-01

    Full Text Available No presente estudo o empenamento de peças de polietileno linear de baixa densidade (PELBD moldadas por rotomoldagem foi investigado. O efeito de diferentes fatores como espessura da peça, taxa de resfriamento e diâmetro de tubo de ventilação foi avaliado. Além dos experimentos de rotomoldagem, uma técnica alternativa denominada "Hot Press" foi também aplicada para investigar o empenamento de dois diferentes PELBD sob condições típicas da rotomoldagem quanto ao resfriamento assimétrico. Cristalinidade e morfologia esferulítica ao longo da espessura das peças rotomoldadas foram avaliadas por Calorimetria Exploratória Diferencial (DSC e Microscopia Ótica de Luz Polarizada. Verificou-se que o grau de empenamento aumenta com a taxa de resfriamento. O aumento do diâmetro do tubo de ventilação é mais efetivo na redução do empenamento principalmente em menores taxas de resfriamento. Nos experimentos de "Hot Press" o PELBD com menor índice de fluidez e maior módulo de flexão apresentou menor empenamento. Nos experimentos de "Hot Press" a espessura das peças afetou o empenamento somente para maiores taxas de resfriamento. Em geral, a cristalinidade e o tamanho de esferulitos se mostraram menores nas posições ao longo da espessura das peças rotomodadas onde as taxas de resfriamento eram mais rápidas.In the present study the warpage of rotationally molded parts of a linear low density polyethylene (LLDPE was investigated. The effect from different processing factors such as part thickness, cooling condition and diameter of the venting tube was evaluated. In addition to the rotational molding experiments, an alternative experimental technique, referred to as "Hot Press", was also applied to investigate the warpage of two different grades of LLDPE under typical rotational molding conditions, which means slow cooling from only one side. The crystallinity and spherulitic morphology along the thickness of the rotationally molded

  2. CFD modeling of pharmaceutical isolators with experimental verification of airflow.

    Science.gov (United States)

    Nayan, N; Akay, H U; Walsh, M R; Bell, W V; Troyer, G L; Dukes, R E; Mohan, P

    2007-01-01

    Computational fluid dynamics (CFD) models have been developed to predict the airflow in a transfer isolator using a commercial CFD code. In order to assess the ability of the CFD approach in predicting the flow inside an isolator, hot wire anemometry measurements and a novel experimental flow visualization technique consisting of helium-filled glycerin bubbles were used. The results obtained have been shown to agree well with the experiments and show that CFD can be used to model barrier systems and isolators with practical fidelity. This indicates that CFD can and should be used to support the design, testing, and operation of barrier systems and isolators.

  3. Contact drying: a review of experimental and mechanistic modeling approaches.

    Science.gov (United States)

    Sahni, Ekneet Kaur; Chaudhuri, Bodhisattwa

    2012-09-15

    Drying is one of the most complex unit operations with simultaneous heat and mass transfer. The contact drying process is also not well understood as several physical phenomena occur concurrently. This paper reviews current experimental and modeling approaches employed towards a better understanding of the contact drying operation. Additionally, an overview of some fundamental aspects relating to contact drying is provided. A brief discussion of some model extensions such as incorporation of noncontact forces, interstitial fluids and attrition rate is also presented. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Pneumatic Adaptive Absorber: Mathematical Modelling with Experimental Verification

    Directory of Open Access Journals (Sweden)

    Grzegorz Mikułowski

    2016-01-01

    Full Text Available Many of mechanical energy absorbers utilized in engineering structures are hydraulic dampers, since they are simple and highly efficient and have favourable volume to load capacity ratio. However, there exist fields of applications where a threat of toxic contamination with the hydraulic fluid contents must be avoided, for example, food or pharmacy industries. A solution here can be a Pneumatic Adaptive Absorber (PAA, which is characterized by a high dissipation efficiency and an inactive medium. In order to properly analyse the characteristics of a PAA, an adequate mathematical model is required. This paper proposes a concept for mathematical modelling of a PAA with experimental verification. The PAA is considered as a piston-cylinder device with a controllable valve incorporated inside the piston. The objective of this paper is to describe a thermodynamic model of a double chamber cylinder with gas migration between the inner volumes of the device. The specific situation considered here is that the process cannot be defined as polytropic, characterized by constant in time thermodynamic coefficients. Instead, the coefficients of the proposed model are updated during the analysis. The results of the experimental research reveal that the proposed mathematical model is able to accurately reflect the physical behaviour of the fabricated demonstrator of the shock absorber.

  5. Experimental models in vaccine research: malaria and leishmaniasis

    Directory of Open Access Journals (Sweden)

    C. Teixeira

    2013-02-01

    Full Text Available Animal models have a long history of being useful tools, not only to test and select vaccines, but also to help understand the elaborate details of the immune response that follows infection. Different models have been extensively used to investigate putative immunological correlates of protection against parasitic diseases that are important to reach a successful vaccine. The greatest challenge has been the improvement and adaptation of these models to reflect the reality of human disease and the screening of vaccine candidates capable of overcoming the challenge of natural transmission. This review will discuss the advantages and challenges of using experimental animal models for vaccine development and how the knowledge achieved can be extrapolated to human disease by looking into two important parasitic diseases: malaria and leishmaniasis.

  6. Experimental models in vaccine research: malaria and leishmaniasis.

    Science.gov (United States)

    Teixeira, C; Gomes, R

    2013-02-01

    Animal models have a long history of being useful tools, not only to test and select vaccines, but also to help understand the elaborate details of the immune response that follows infection. Different models have been extensively used to investigate putative immunological correlates of protection against parasitic diseases that are important to reach a successful vaccine. The greatest challenge has been the improvement and adaptation of these models to reflect the reality of human disease and the screening of vaccine candidates capable of overcoming the challenge of natural transmission. This review will discuss the advantages and challenges of using experimental animal models for vaccine development and how the knowledge achieved can be extrapolated to human disease by looking into two important parasitic diseases: malaria and leishmaniasis.

  7. Experimental model of cultured keratinocytes Modelo experimental de cultura de queratinócitos

    Directory of Open Access Journals (Sweden)

    Alfredo Gragnani

    2003-01-01

    Full Text Available The bioengineering research is essential in the development of ideal combination of biomaterials and cultured cells to produce the permanent wound coverage. The experimental model of cultured keratinocytes presents all steps of the culture, since the isolation of the keratinocytes, preparation of the human acellular dermis, preparation of the composite skin graft and their elevation to the air-liquid interface. The research in cultured keratinocytes model advances in two main ways: 1. optimization of the methods in vitro to the skin cells culture and proliferation and 2. developing biomaterials that present similar skin properties.A pesquisa em bioengenharia é primordial no desenvolvimento da combinação ideal de biomateriais e células cultivadas para produzir a cobertura definitiva das lesões. O modelo experimental da cultura de queratinócitos apresenta toda as etapas do cultivo, desde o isolamento dos queratinócitos, preparação da derme acelular humana, do enxerto composto e da sua elevação à interface ar-líquido. A pesquisa em modelo de cultura de queratinócitos desenvolve-se em duas vias principais: 1. otimização dos métodos in vitro para cultivo e proliferação de células da pele e 2. desenvolvimento de biomateriais que mimetizem as propriedades da pele.

  8. DMFC anode polarization: Experimental analysis and model validation

    Energy Technology Data Exchange (ETDEWEB)

    Casalegno, A.; Marchesi, R. [Dipartimento di Energetica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2008-01-03

    Anode two-phase flow has an important influence on DMFC performance and methanol crossover. In order to elucidate two-phase flow influence on anode performance, in this work, anode polarization is investigated combining experimental and modelling approach. A systematic experimental analysis of operating conditions influence on anode polarization is presented. Hysteresis due to operating condition is observed; experimental results suggest that it arises from methanol accumulation and has to be considered in evaluating DMFC performances and measurements reproducibility. A model of DMFC anode polarization is presented and utilised as tool to investigate anode two-phase flow. The proposed analysis permits one to produce a confident interpretation of the main involved phenomena. In particular, it confirms that methanol electro-oxidation kinetics is weakly dependent on methanol concentration and that methanol transport in gas phase produces an important contribution in anode feeding. Moreover, it emphasises the possibility to optimise anode flow rate in order to improve DMFC performance and reduce methanol crossover. (author)

  9. Of mice and men: modelling post-stroke depression experimentally

    Science.gov (United States)

    Kronenberg, G; Gertz, K; Heinz, A; Endres, M

    2014-01-01

    At least one-third of stroke survivors suffer from depression. The development of comorbid depression after stroke is clinically highly significant because post-stroke depression is associated with increased mortality, slows recovery and leads to worse functional outcomes. Here, we review the evidence that post-stroke depression can be effectively modelled in experimental rodents via a variety of approaches. This opens an exciting new window onto the neurobiology of depression and permits probing potential underlying mechanisms such as disturbed cellular plasticity, neuroendocrine dysregulation, neuroinflammation, and neurodegeneration in a novel context. From the point of view of translational stroke research, extending the scope of experimental investigations beyond the study of short-term end points and, in particular, acute lesion size, may help improve the relevance of preclinical results to human disease. Furthermore, accumulating evidence from both clinical and experimental studies offers the tantalizing prospect of 5-hydroxytryptaminergic antidepressants as the first pharmacological therapy for stroke that would be available during the subacute and chronic phases of recovery. Interdisciplinary neuropsychiatric research will be called on to dissect the mechanisms underpinning the beneficial effects of antidepressants on stroke recovery. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24838087

  10. Analytical modeling and experimental characterization of chemotaxis in Serratia marcescens

    Science.gov (United States)

    Zhuang, Jiang; Wei, Guopeng; Wright Carlsen, Rika; Edwards, Matthew R.; Marculescu, Radu; Bogdan, Paul; Sitti, Metin

    2014-05-01

    This paper presents a modeling and experimental framework to characterize the chemotaxis of Serratia marcescens (S. marcescens) relying on two-dimensional and three-dimensional tracking of individual bacteria. Previous studies mainly characterized bacterial chemotaxis based on population density analysis. Instead, this study focuses on single-cell tracking and measuring the chemotactic drift velocity VC from the biased tumble rate of individual bacteria on exposure to a concentration gradient of l-aspartate. The chemotactic response of S. marcescens is quantified over a range of concentration gradients (10-3 to 5 mM/mm) and average concentrations (0.5×10-3 to 2.5 mM). Through the analysis of a large number of bacterial swimming trajectories, the tumble rate is found to have a significant bias with respect to the swimming direction. We also verify the relative gradient sensing mechanism in the chemotaxis of S. marcescens by measuring the change of VC with the average concentration and the gradient. The applied full pathway model with fitted parameters matches the experimental data. Finally, we show that our measurements based on individual bacteria lead to the determination of the motility coefficient μ (7.25×10-6 cm2/s) of a population. The experimental characterization and simulation results for the chemotaxis of this bacterial species contribute towards using S. marcescens in chemically controlled biohybrid systems.

  11. An experimental and modeling study of diethyl carbonate oxidation

    KAUST Repository

    Nakamura, Hisashi

    2015-04-01

    Diethyl carbonate (DEC) is an attractive biofuel that can be used to displace petroleum-derived diesel fuel, thereby reducing CO2 and particulate emissions from diesel engines. A better understanding of DEC combustion characteristics is needed to facilitate its use in internal combustion engines. Toward this goal, ignition delay times for DEC were measured at conditions relevant to internal combustion engines using a rapid compression machine (RCM) and a shock tube. The experimental conditions investigated covered a wide range of temperatures (660-1300K), a pressure of 30bar, and equivalence ratios of 0.5, 1.0 and 2.0 in air. To provide further understanding of the intermediates formed in DEC oxidation, species concentrations were measured in a jet-stirred reactor at 10atm over a temperature range of 500-1200K and at equivalence ratios of 0.5, 1.0 and 2.0. These experimental measurements were used to aid the development and validation of a chemical kinetic model for DEC.The experimental results for ignition in the RCM showed near negative temperature coefficient (NTC) behavior. Six-membered alkylperoxy radical (RO˙2) isomerizations are conventionally thought to initiate low-temperature branching reactions responsible for NTC behavior, but DEC has no such possible 6- and 7-membered ring isomerizations. However, its molecular structure allows for 5-, 8- and 9-membered ring RO˙2 isomerizations. To provide accurate rate constants for these ring structures, ab initio computations for RO˙2⇌Q˙OOH isomerization reactions were performed. These new RO˙2 isomerization rate constants have been implemented in a chemical kinetic model for DEC oxidation. The model simulations have been compared with ignition delay times measured in the RCM near the NTC region. Results of the simulation were also compared with experimental results for ignition in the high-temperature region and for species concentrations in the jet-stirred reactor. Chemical kinetic insights into the

  12. Determinação da Estrutura de Diferentes Álcoois Terpênicos: Um Estudo Teórico e Experimental

    Directory of Open Access Journals (Sweden)

    Naiara Letícia Marana

    2013-05-01

    Full Text Available Terpene compounds is a major class of natural products found in nature, although having a relatively simple structure, their 1H-NMR spectra and 13C are complex and have many overlapping signals. The present study aimed to conduct a theoretical and experimental study in order to determine the structure of different chiral alcohols through the use of theoretical calculations of NMR shielding tensors (δ and their comparison with the experimental chemical shifts. The results show that the level of theory adopted in our studies to describe the structure of the alcohol was adequate, with a good theoretical and experimental correlation assists in determining what structure.

  13. Experimental validation of Swy-2 clay standard's PHREEQC model

    Science.gov (United States)

    Szabó, Zsuzsanna; Hegyfalvi, Csaba; Freiler, Ágnes; Udvardi, Beatrix; Kónya, Péter; Székely, Edit; Falus, György

    2017-04-01

    One of the challenges of the present century is to limit the greenhouse gas emissions for the mitigation of climate change which is possible for example by a transitional technology, CCS (Carbon Capture and Storage) and, among others, by the increase of nuclear proportion in the energy mix. Clay minerals are considered to be responsible for the low permeability and sealing capacity of caprocks sealing off stored CO2 and they are also the main constituents of bentonite in high level radioactive waste disposal facilities. The understanding of clay behaviour in these deep geological environments is possible through laboratory batch experiments of well-known standards and coupled geochemical models. Such experimentally validated models are scarce even though they allow deriving more precise long-term predictions of mineral reactions and rock and bentonite degradation underground and, therefore, ensuring the safety of the above technologies and increase their public acceptance. This ongoing work aims to create a kinetic geochemical model of Na-montmorillonite standard Swy-2 in the widely used PHREEQC code, supported by solution and mineral composition results from batch experiments. Several four days experiments have been carried out in 1:35 rock:water ratio at atmospheric conditions, and with inert and CO2 supercritical phase at 100 bar and 80 ⁰C relevant for the potential Hungarian CO2 reservoir complex. Solution samples have been taken during and after experiments and their compositions were measured by ICP-OES. The treated solid phase has been analysed by XRD and ATR-FTIR and compared to in-parallel measured references (dried Swy-2). Kinetic geochemical modelling of the experimental conditions has been performed by PHREEQC version 3 using equations and kinetic rate parameters from the USGS report of Palandri and Kharaka (2004). The visualization of experimental and numerous modelling results has been automatized by R. Experiments and models show very fast

  14. Estudo experimental dos efeitos da heparina de baixo peso molecular (Enoxaparina na formação de calo ósseo em fêmures de ratos The effects of low-molecular-weight heparin (Enoxaparin on bony callus formation in rats' femurs - an experimental study

    Directory of Open Access Journals (Sweden)

    Salim Mussi Filho

    2006-01-01

    Full Text Available O tromboembolismo venoso é uma complicação grave que pode ocorrer após fraturas. O tratamento anticoagulante mais utilizado é com a heparina de baixo peso molecular (HBPM. Existem estudos que mostram que essa droga pode interferir no metabolismo ósseo. Com o objetivo de avaliar a influência da HBPM no processo de formação de calo ósseo, realizamos um estudo experimental em ratos. A amostra constituiu-se de 22 ratos de linhagem Wistar, machos, que foram submetidos à fratura diafisária de seus fêmures direitos. Foram divididos em dois grupos de 11. No grupo controle, os animais recebiam soro fisiológico e no grupo de estudo, recebiam HBPM, enoxaparina, diariamente, por 28 dias. Após este período os ratos foram submetidos à eutanásia e os fêmures foram avaliados. No estudo macroscópico foi constatada consolidação em 11 animais (100% que não receberam enoxaparina, e, em dez animais (90,9% que receberam a droga em estudo. No estudo histológico foi constatada a formação de calo ósseo em todos os fêmures. Concluiu-se neste experimento que a enoxaparina não altera o processo de consolidação óssea em fêmures de ratos Wistar.Venous thromboembolism is a serious complication that may follow fractures. The most commonly used anticoagulant treatment is low-molecular-weight heparin (LMWH. There are some studies showing that this drug may interfere on bone metabolism. With the objective of evaluating the LMWH influence on the process of bony callus formation, we conducted an experimental study on rats. Sample was constituted of 22 Wistar male rats, which were submitted to diaphyseal fracture on their right femurs. They were divided into two groups of 11 subjects each. In the control group, the animals received saline solution and in the study group, they received LMWH - enoxaparin - in a daily basis, during 28 days. After that period, the rats were submitted to euthanasia for femur assessment purposes. At the macroscopic study

  15. Experimental validation of solid rocket motor damping models

    Science.gov (United States)

    Riso, Cristina; Fransen, Sebastiaan; Mastroddi, Franco; Coppotelli, Giuliano; Trequattrini, Francesco; De Vivo, Alessio

    2017-12-01

    In design and certification of spacecraft, payload/launcher coupled load analyses are performed to simulate the satellite dynamic environment. To obtain accurate predictions, the system damping properties must be properly taken into account in the finite element model used for coupled load analysis. This is typically done using a structural damping characterization in the frequency domain, which is not applicable in the time domain. Therefore, the structural damping matrix of the system must be converted into an equivalent viscous damping matrix when a transient coupled load analysis is performed. This paper focuses on the validation of equivalent viscous damping methods for dynamically condensed finite element models via correlation with experimental data for a realistic structure representative of a slender launch vehicle with solid rocket motors. A second scope of the paper is to investigate how to conveniently choose a single combination of Young's modulus and structural damping coefficient—complex Young's modulus—to approximate the viscoelastic behavior of a solid propellant material in the frequency band of interest for coupled load analysis. A scaled-down test article inspired to the Z9-ignition Vega launcher configuration is designed, manufactured, and experimentally tested to obtain data for validation of the equivalent viscous damping methods. The Z9-like component of the test article is filled with a viscoelastic material representative of the Z9 solid propellant that is also preliminarily tested to investigate the dependency of the complex Young's modulus on the excitation frequency and provide data for the test article finite element model. Experimental results from seismic and shock tests performed on the test configuration are correlated with numerical results from frequency and time domain analyses carried out on its dynamically condensed finite element model to assess the applicability of different equivalent viscous damping methods to describe

  16. Experimental limits from ATLAS on Standard Model Higgs production.

    CERN Multimedia

    ATLAS, collaboration

    2012-01-01

    Experimental limits from ATLAS on Standard Model Higgs production in the mass range 110-600 GeV. The solid curve reflects the observed experimental limits for the production of a Higgs of each possible mass value (horizontal axis). The region for which the solid curve dips below the horizontal line at the value of 1 is excluded with a 95% confidence level (CL). The dashed curve shows the expected limit in the absence of the Higgs boson, based on simulations. The green and yellow bands correspond (respectively) to 68%, and 95% confidence level regions from the expected limits. Higgs masses in the narrow range 123-130 GeV are the only masses not excluded at 95% CL

  17. Experimentally supported mathematical modeling of continuous baking processes

    DEFF Research Database (Denmark)

    Stenby Andresen, Mette

    The scope of the PhD project was to increase knowledge on the process-to-product interactions in continuous tunnel ovens. The work has focused on five main objectives. These objectives cover development of new experimental equipment for pilot plant baking experiments, mathematical modeling of heat...... and mass transfer in a butter cookie product, and evaluation of quality assessment methods. The pilot plant oven is a special batch oven designed to emulate continuous convection tunnel oven baking. The design, construction, and validation of the oven has been part of the project and is described...... in this thesis. The oven was successfully validated against a 10 m tunnel oven. Besides the ability to emulate the baking conditions in a tunnel oven, the new batch oven is designed and constructed for experimental research work. In the design options to follow the product continuously (especially weight...

  18. Continuum damage modeling through theoretical and experimental pressure limit formulas

    Directory of Open Access Journals (Sweden)

    Fatima Majid

    2018-01-01

    Full Text Available In this paper, we developed a mathematical modeling to represent the damage of thermoplastic pipes. On the one hand, we adapted the theories of the rupture pressure to fit the High Density Polyethylene (HDPE case. Indeed, the theories for calculating the rupture pressure are multiple, designed originally for steels and alloys. For polymer materials, we have found that these theories can be adapted using a coefficient related to the nature of the studied material. The HDPE is characterized by two important values of pressure, deduced from the ductile form of the internal pressures evolution until burst. For this reason, we have designed an alpha coefficient taking into account these two pressures and giving a good approximation of the evolution of the experimental burst pressures through the theoretically corrected ones, using Faupel㒒s pressure formula. Then, we can deduce the evolution of the theoretical damage using the calculated pressures. On the other hand, two other mathematical models were undertaken. The first one has given rise to an adaptive model referring to an expression of the pressure as a function of the life fraction, the characteristic pressures and the critical life fraction. The second model represents a continuum damage model incorporating the pressure equations as a function of the life fraction and based on the burst pressure�s static damage model. These models represent important tools for industrials to assess the failure of thermoplastic pipes and proceed quick checks

  19. Short note: the experimental geopotential model XGM2016

    Science.gov (United States)

    Pail, R.; Fecher, T.; Barnes, D.; Factor, J. F.; Holmes, S. A.; Gruber, T.; Zingerle, P.

    2017-10-01

    As a precursor study for the upcoming combined Earth Gravitational Model 2020 (EGM2020), the Experimental Gravity Field Model XGM2016, parameterized as a spherical harmonic series up to degree and order 719, is computed. XGM2016 shares the same combination methodology as its predecessor model GOCO05c (Fecher et al. in Surv Geophys 38(3): 571-590, 2017. doi: 10.1007/s10712-016-9406-y). The main difference between these models is that XGM2016 is supported by an improved terrestrial data set of 15^' × 15^' gravity anomaly area-means provided by the United States National Geospatial-Intelligence Agency (NGA), resulting in significant upgrades compared to existing combined gravity field models, especially in continental areas such as South America, Africa, parts of Asia, and Antarctica. A combination strategy of relative regional weighting provides for improved performance in near-coastal ocean regions, including regions where the altimetric data are mostly unchanged from previous models. Comparing cumulative height anomalies, from both EGM2008 and XGM2016 at degree/order 719, yields differences of 26 cm in Africa and 40 cm in South America. These differences result from including additional information of satellite data, as well as from the improved ground data in these regions. XGM2016 also yields a smoother Mean Dynamic Topography with significantly reduced artifacts, which indicates an improved modeling of the ocean areas.

  20. Processo inflamatório crônico granulomatoso experimental em peixes: um estudo morfológico, ultraestrutural e imunohistoquímico

    Directory of Open Access Journals (Sweden)

    Eliana Reiko Matushima

    2006-04-01

    Full Text Available O objetivo do presente estudo foi avaliar o processo inflamatório crônico granulomatoso induzido experimentalmente em Oreochromis niloticus através da inoculação de BCG e elucidar aspectos da reação inflamatória em peixes para uma melhor compreensão da filogenia do processo. Os resultados obtidos por microscopia de luz comum e ultra-estrutural demonstraram a participação de macrófagos, trombócitos, linfócitos, eosinófilos, células plasmáticas e células gigante tipo corpo estranho no processo inflamatório. Além desses tipos celulares, uma reação granulomatosa constituída predominantemente de células epitelióides também foram observadas ultraestruturalmente. Essas células epitelióides desenvolveram desmossomos ao longo do experimento, e também passaram a expressar receptores para citoqueratina, características estas de células epiteliais. Células pigmentares (melanomacrófagos, envolvendo de maneira crescente toda a formação granulomatóide e, participando ativamente da reação inflamatória crônica granulomatosa.

  1. O pulmão na doença inflamatória do cólon: estudo experimental em ratos

    Directory of Open Access Journals (Sweden)

    Biondo-Simões Maria de Lourdes Pessole

    2000-01-01

    Full Text Available Embora a colite ulcerativa seja conhecida desde 1875 e muitas sejam as manifestações extra-intestinais descritas nesta doença, só recentemente chamou-se a atenção para o envolvimento do aparelho respiratório. Severas complicações têm sido descritas em pacientes como: estenose traqueal inflamatória, bronquiolite com pneumonia, pneumonite intersticial, granulomatose de Wegener, bronquite crônica com bronquiectasia, nódulos necrobióticos, vasculites, fibrose e alveolites. O presente estudo visa reconhecer as alterações pulmonares, na fase aguda da doença inflamatória do cólon, induzida em ratos com ácido acético à 10% e comparar com controles normais. Foi possível constatar que 100% dos animais com colite apresentaram reação inflamatória pulmonar (p=0,0210 de intensidade moderada à severa (p=0,0340. Vasculite foi vista em 58,33% dos pulmões (p=0,0060 e em 3 animais detectou-se hemorragia focal, necrose e abscesso. Estes achados permitem atribuir uma forte associação entre a doença inflamatória do cólon e alterações do aparêlho respiratório, durante a fase aguda da doença, em ratos.

  2. Experimental validation of mathematical model for small air compressor

    Directory of Open Access Journals (Sweden)

    Tuhovčák Ján

    2017-01-01

    Full Text Available Development process of reciprocating compressors can be simplified by using simulation tools. Modelling of a compressor requires a trade-off between computational effort and accuracy of desired results. This paper presents experimental validation of the simulation tool, which can be used to predict compressor behaviour under different working conditions. The mathematical model provides fast results with very good accuracy, however the model must be calibrated for a certain type of compressor. Small air compressor was used to validate an in-house simulation tool, which is based on mass and energy conservation in a control volume. The simulation tool calculates pressure and temperature history inside the cylinder, valve characteristics, mass flow and heat losses during the cycle of the compressor. A test bench for the compressor consisted of pressure sensors on both discharge and suction side, temperature sensor on discharge side and flow meter with calorimetric principle sensor.

  3. A two-Higgs-doublet model facing experimental hints

    Directory of Open Access Journals (Sweden)

    Crivellin Andreas

    2016-01-01

    Full Text Available Physics beyond the Standard Model has so far eluded our experimental probes. Nevertheless, a number of interesting anomalies have accumulated that can be taken as hints towards new physics: BaBar, Belle, and LHCb have found deviations of approximately 3:8σ in B → Dτν and B → D*τν; the anomalous magnetic moment of the muon differs by about 3σ from the theoretic prediction; the branching ratio for τ → μνν is about 2σ above the Standard Model expectation; and CMS and ATLAS found hints for a non-zero decay rate of h → μτ at 2.6σ. Here we consider these processes within a lepton-specific two-Higgs doublet model with additional non-standard Yukawa couplings and show how (and which of these excesses can be accommodated.

  4. Comparison of mixed layer models predictions with experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Faggian, P.; Riva, G.M. [CISE Spa, Divisione Ambiente, Segrate (Italy); Brusasca, G. [ENEL Spa, CRAM, Milano (Italy)

    1997-10-01

    The temporal evolution of the PBL vertical structure for a North Italian rural site, situated within relatively large agricultural fields and almost flat terrain, has been investigated during the period 22-28 June 1993 by experimental and modellistic point of view. In particular, the results about a sunny day (June 22) and a cloudy day (June 25) are presented in this paper. Three schemes to estimate mixing layer depth have been compared, i.e. Holzworth (1967), Carson (1973) and Gryning-Batchvarova models (1990), which use standard meteorological observations. To estimate their degree of accuracy, model outputs were analyzed considering radio-sounding meteorological profiles and stability atmospheric classification criteria. Besides, the mixed layer depths prediction were compared with the estimated values obtained by a simple box model, whose input requires hourly measures of air concentrations and ground flux of {sup 222}Rn. (LN)

  5. Vídeo-artroscopia da articulação fêmorotibiopatelar de cães antes e 21 dias após secção do ligamento cruzado cranial (estudo experimental).

    OpenAIRE

    Natalie Ferreira Borges

    2006-01-01

    A ruptura do ligamento cruzado cranial (LCC) é uma lesão comum e significativa em cães, cuja instabilidade articular pode levar ao desenvolvimento de alterações degenerativas. O objetivo deste estudo foi avaliar e classificar por meio da vídeoartroscopia, as alterações da articulação fêmoro-tíbio-patelar (FTP) 21 dias após secção experimental do LCCr, tendo como referência os parâmetros encontrados no exame artroscópico imediatamente anterior à secção. Foram utilizados 18 cães, sem raça defin...

  6. Evaluation of Algebraic Reynolds Stress Model Assumptions Using Experimental Data

    Science.gov (United States)

    Jyoti, B.; Ewing, D.; Matovic, D.

    1996-11-01

    The accuracy of Rodi's ASM assumption is examined by evaluating the terms in Reynolds stress transport equation and their modelled counterparts. The basic model assumption: Dτ_ij/Dt + partial T_ijl/partial xl = (τ_ij/k )(Dk/Dt + partial Tl /partial xl ) (Rodi( Rodi W., ZAMM.), 56, pp. 219-221, 1976.), can also be broken into two stronger assumptions: Da_ij/Dt = 0 and (2) partial T_ijl/partial xl = (τ_ij/k )(partial Tl /partial xl ) (e.g. Taulbee( Taulbee D. B., Phys. of Fluids), 4(11), pp. 2555-2561, 1992.). Fu et al( Fu S., Huang P.G., Launder B.E. & Leschziner M.A., J. Fluid Eng.), 110(2), pp. 216-221., 1988 examined the accuracy of Rodi's assumption using the results of RSM calculation of axisymmetric jets. Since the RSM results did not accurately predict the experimental results either, it may be useful to examine the basic ASM model assumptions using experimental data. The database of Hussein, Capp and George( Hussein H., Capp S. & George W., J.F.M.), 258, pp.31-75., 1994. is sufficiently detailed to evaluate the terms of Reynolds stress transport equations individually, thus allowing both Rodi's and the stronger assumptions to be tested. For this flow assumption (1) is well satisfied for all the components (including \\overlineuv); however, assumption (2) does not seem as well satisfied.

  7. Neuroinflammatory targets and treatments for epilepsy validated in experimental models.

    Science.gov (United States)

    Aronica, Eleonora; Bauer, Sebastian; Bozzi, Yuri; Caleo, Matteo; Dingledine, Raymond; Gorter, Jan A; Henshall, David C; Kaufer, Daniela; Koh, Sookyong; Löscher, Wolfgang; Louboutin, Jean-Pierre; Mishto, Michele; Norwood, Braxton A; Palma, Eleonora; Poulter, Michael O; Terrone, Gaetano; Vezzani, Annamaria; Kaminski, Rafal M

    2017-07-01

    A large body of evidence that has accumulated over the past decade strongly supports the role of inflammation in the pathophysiology of human epilepsy. Specific inflammatory molecules and pathways have been identified that influence various pathologic outcomes in different experimental models of epilepsy. Most importantly, the same inflammatory pathways have also been found in surgically resected brain tissue from patients with treatment-resistant epilepsy. New antiseizure therapies may be derived from these novel potential targets. An essential and crucial question is whether targeting these molecules and pathways may result in anti-ictogenesis, antiepileptogenesis, and/or disease-modification effects. Therefore, preclinical testing in models mimicking relevant aspects of epileptogenesis is needed to guide integrated experimental and clinical trial designs. We discuss the most recent preclinical proof-of-concept studies validating a number of therapeutic approaches against inflammatory mechanisms in animal models that could represent novel avenues for drug development in epilepsy. Finally, we suggest future directions to accelerate preclinical to clinical translation of these recent discoveries. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  8. Hepatoprotective activity of Musa paradisiaca on experimental animal models.

    Science.gov (United States)

    Nirmala, M; Girija, K; Lakshman, K; Divya, T

    2012-01-01

    To investigate the hepatoprotective activity of stem of Musa paradisiaca (M. paradisiaca) in CCl4 and paracetamol induced hepatotoxicity models in rats. Hepatoprotective activity of alcoholic and aqueous extracts of stem of M. paradisiaca was demonstrated by using two experimentally induced hepatotoxicity models. Administration of hepatotoxins (CCl4 and paracetamol) showed significant biochemical and histological deteriorations in the liver of experimental animals. Pretreatment with alcoholic extract (500 mg/kg), more significantly and to a lesser extent the alcoholic extract (250 mg/kg) and aqueous extract (500 mg/kg), reduced the elevated levels of the serum enzymes like serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP) and bilirubin levels and alcoholic and aqueous extracts reversed the hepatic damage towards the normal, which further evidenced the hepatoprotective activity of stem of M. paradisiaca. The alcoholic extract at doses of 250 and 500 mg/kg, p.o. and aqueous extract at a dose of 500 mg/kg, p.o. of stem of M. paradisiaca have significant effect on the liver of CCl4 and paracetamol induced hepatotoxicity animal models.

  9. A comprehensive experimental and modeling study of 2-methylbutanol combustion

    KAUST Repository

    Park, Sungwoo

    2015-05-01

    2-Methylbutanol (2-methyl-1-butanol) is one of several next-generation biofuels that can be used as an alternative fuel or blending component for combustion engines. This paper presents new experimental data for 2-methylbutanol, including ignition delay times in a high-pressure shock tube and premixed laminar flame speeds in a constant volume combustion vessel. Shock tube ignition delay times were measured for 2-methylbutanol/air mixtures at three equivalence ratios, temperatures ranging from 750 to 1250. K, and at nominal pressures near 20 and 40. bar. Laminar flame speed data were obtained using the spherically propagating premixed flame configuration at pressures of 1, 2, and 5. bar. A detailed chemical kinetic model for 2-methylbutanol oxidation was developed including high- and low-temperature chemistry based on previous modeling studies on butanol and pentanol isomers. The proposed model was tested against new and existing experimental data at pressures of 1-40. atm, temperatures of 740-1636. K, equivalence ratios of 0.25-2.0. Reaction path and sensitivity analyses were conducted for identifying key reactions at various combustion conditions, and to obtain better understanding of the combustion characteristics of larger alcohols.

  10. Padronização da pesquisa de linfonodos sentinelas em estômago por métodos combinados : estudo experimental em coelhos = Standardization of sentinel lymph node navigation in stomach by combined methods: experimental study in rabbits

    OpenAIRE

    José Roberto Alves

    2012-01-01

    Resumo: Introdução - Com os estudos de Gould et al. (1960), Cabanas (1977) e Morton et al. (1992), estabeleceu-se o conceito da pesquisa do linfonodo sentinela. Esse se baseia na teoria de que ao identificar a presença ou ausência de metástase no primeiro linfonodo que recebe a drenagem linfática a partir do tumor (sentinela), poderia representar o estado de acometimento dos outros linfonodos. Isto evitaria a realização desnecessária de linfadenectomias. Com o passar dos anos, foi consagrada ...

  11. Modelos experimentais de esquizofrenia: uma revisão Experimental models of schizophrenia: a review

    Directory of Open Access Journals (Sweden)

    João Vinícius Salgado

    2006-06-01

    Full Text Available OBJETIVO: O uso de modelos experimentais tem permitido importantes avanços no diagnóstico e na terapêutica de doenças somáticas, tais como diabetes e hipertensão. No caso da esquizofrenia, entretanto, as tentativas de modelos experimentais causaram, historicamente, pouco impacto e algum ceticismo. Estudos mais recentes, contudo, indicam que a Ciência Cognitiva aplicada ao uso de modelos pode nos ajudar na compreensão da fisiopatologia da esquizofrenia. O estudo objetivou realizar uma revisão crítica dos modelos experimentais propostos para a esquizofrenia. RESULTADOS E DISCUSSÃO: As dificuldades próprias dos modelos de esquizofrenia são a subjetividade dos sintomas, a dificuldade em reproduzi-los em animais e a complexidade clínica a ser totalizada. Fenótipo tão complexo só pode ser abordado pela separação de seus componentes (endofenótipos e pela respectiva manipulação de seus correlatos experimentais, feita por intervenções específicas (e.g. farmacológicas, cirúrgicas, genéticas na busca de um mecanismo comum para estes endofenótipos. A correlação entre resultados e sintomas deve apoiar-se em hipótese explanatória abrangente. Até o presente, a doença parece envolver desconexão neuronal difusa decorrente de anormalidades cerebrais sutis, de causa genética e/ou ambiental. CONCLUSÕES: A integração da informação dos modelos atualmente em uso pode contribuir de modo significativo para a compreensão da esquizofrenia.OBJECTIVE: Diagnostic and therapy of somatic diseases like diabetes and hypertension have improved notably with the use of experimental models. For schizophrenia the proposal of a model has made little impact and even scepticism. Nevertheless the most recent studies indicate that "Cognitive Sciences" applied to specific models may help us to find out mechanisms of the disease. This article reviews the models presently under investigation for schizophrenia. RESULTS AND DISCUSSION: The difficulty

  12. Model reduction for experimental thermal characterization of a holding furnace

    Science.gov (United States)

    Loussouarn, Thomas; Maillet, Denis; Remy, Benjamin; Dan, Diane

    2017-09-01

    Vacuum holding induction furnaces are used for the manufacturing of turbine blades by loss wax foundry process. The control of solidification parameters is a key factor for the manufacturing of these parts. The definition of the structure of a reduced heat transfer model with experimental identification through an estimation of its parameters is required here. Internal sensors outputs, together with this model, can be used for assessing the thermal state of the furnace through an inverse approach, for a better control. Here, an axisymmetric furnace and its load have been numerically modelled using FlexPDE, a finite elements code. The internal induction heat source as well as the transient radiative transfer inside the furnace are calculated through this detailed model. A reduced lumped body model has been constructed to represent the numerical furnace. The model reduction and the estimation of the parameters of the lumped body have been made using a Levenberg-Marquardt least squares minimization algorithm, using two synthetic temperature signals with a further validation test.

  13. Experimental models of sepsis and septic shock: an overview

    Directory of Open Access Journals (Sweden)

    Garrido Alejandra G.

    2004-01-01

    Full Text Available Sepsis remains a major cause of morbidity and mortality in surgical patients and trauma victims, mainly due to sepsis-induced multiple organ dysfunction. In contrast to preclinical studies, most clinical trials of promising new treatment strategies for sepsis have fails to demonstrate efficacy. Although many reasons could account for this discrepancy, the misinterpretation of preclinical data obtained from experimental studies, and especially the use of animal models that do not adequately mimic human sepsis may have been contributing factors. In this review, the benefits and limitations of various animal models of sepsis are discussed to clarify the extend to which findings are relevant to human sepsis, particularly with respect to the subsequent design and execution of clinical trials. Such models include intravascular infusion of endotoxin or live bacteria, bacterial peritonitis, cecal ligation and perforation, soft tissue infection, pneumonia or meningitis models, using different animal species including rats, mice, rabbits, dogs, pigs, sheep and nonhuman primates. Despite several limitations, animal models remain essential in the development of all new therapies for sepsis and septic shock, because they provide fundamental information about the pharmacokinetics, toxicity, and mechanism of drug action that cannot be duplicated by other methods. New therapeutic agents should be studies in infection models, even after the initiation of the septic process. Furthermore, debility conditions need to be reproduced to avoid the exclusive use of healthy animals, which often do not represent the human septic patient.

  14. Source of funding and results of studies of health effects of mobile phone use: systematic review of experimental studies Fonte de financiamento e resultados de estudos sobre os efeitos do uso do telefone celular à saúde: revisão sistemática de estudos experimentais

    Directory of Open Access Journals (Sweden)

    Anke Huss

    2008-06-01

    Full Text Available There is concern regarding the possible health effects of cellular telephone use. We conducted a systematic review of studies of controlled exposure to radiofrequency radiation with health-related outcomes (electroencephalogram, cognitive or cardiovascular function, hormone levels, symptoms, and subjective well-being. We searched Embase, Medline, and a specialist database in February 2005 and scrutinized reference lists from relevant publications. Data on the source of funding, study design, methodologic quality, and other study characteristics were extracted. The primary outcome was the reporting of at least one statistically significant association between the exposure and a health-related outcome. Data were analyzed using logistic regression models. Of 59 studies, 12 (20% were funded exclusively by the telecommunications industry, 11 (19% were funded by public agencies or charities, 14 (24% had mixed funding (including industry, and in 22 (37% the source of funding was not reported. Studies funded exclusively by industry reported the largest number of outcomes, but were least likely to report a statistically significant result. The interpretation of results from studies of health effects of radiofrequency radiation should take sponsorship into account.Foi realizada uma revisão sistemática de estudos de exposição controlada à radiação de radiofreqüência com resultados relacionados à saúde (eletroencefalograma, função cognitiva ou cardiovascular, níveis hormonais, sintomas e bem-estar subjetivo. Foram pesquisados o Embase, Medline e um banco de dados especializado e analisadas listas de referências de publicações relevantes. Foram extraídos dados sobre a fonte de financiamento, desenho do estudo, qualidade metodológica e outras características do estudo. A principal descoberta foi o relato de pelo menos uma associação estatisticamente significativa entre a exposição e um resultado relacionado à saúde. Os dados foram

  15. CFD Modeling and Experimental Validation of a Solar Still

    Directory of Open Access Journals (Sweden)

    Mahmood Tahir

    2017-01-01

    Full Text Available Earth is the densest planet of the solar system with total area of 510.072 million square Km. Over 71.68% of this area is covered with water leaving a scant area of 28.32% for human to inhabit. The fresh water accounts for only 2.5% of the total volume and the rest is the brackish water. Presently, the world is facing chief problem of lack of potable water. This issue can be addressed by converting brackish water into potable through a solar distillation process and solar still is specially assigned for this purpose. Efficiency of a solar still explicitly depends on its design parameters, such as wall material, chamber depth, width and slope of the zcondensing surface. This study was aimed at investigating the solar still parameters using CFD modeling and experimental validation. The simulation data of ANSYS-FLUENT was compared with actual experimental data. A close agreement among the simulated and experimental results was seen in the presented work. It reveals that ANSYS-FLUENT is a potent tool to analyse the efficiency of the new designs of the solar distillation systems.

  16. Experimental model for creation of carotid artery aneurysms in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hyun; Han, Moon Hee; Yu, In Kyu; Lee, Sang Hyun; Chang, Kee Hyun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-11-01

    To describe the detailed technique for producing experimental carotid aneurysms in dogs and the success rate, cause of failure and remedy, based on our experience. Fourteen male dogs weighing 12-15kg were anesthetized with inhalation of 1-2% halothane and 50% nitrous oxide. Each surgical procedure was performed under sterile condition with the aid of an operating microscope. A paramidline incision 7-8cm in length was made parallel to and medial to the external jugular vein in the dog's neck. The external jugular vein was harvested as a 1cm vein pouch by ligation and division of the proximal and distal ends. The ipsilateral common carotid artery was exposed and clamped at both ends by a vascular clamp. A 5-mm long elliptical arteriotomy was made at the mid portion of the artery, and then end to side anastomosis between the artery and vein sac was performed by using interrupted 7-0 monofilament prolene sutures. Carotid arteriography or Doppler sonography was performed 1-6 weeks after aneurysm construction. Twenty experimental aneurysms were constructed, and 17 aneurysms were patent on follow up study, but one dog with two aneurysms died from hemorrhagic pneumonia 17 days after surgery. The overall patency rate was 75%. We demonstrated the feasibility of creating experimental aneurysm models in the dog and expect that the technique presented will help to avoid failure in the construction of aneurysms.

  17. Plasma transferred arc welding—modeling and experimental optimization

    Science.gov (United States)

    Wilden, J.; Bergmann, J. P.; Frank, H.

    2006-12-01

    Plasma transferred arc (PTA) welded coatings are used to improve surface properties of mechanical parts. Advantages are the high reliability of the process and the low dilution of substrate and coating material. Processing of surfaces by PTA welding is restricted at the time to flat horizontal position. Furthermore, industry is interested in the development of strategies for coating with PTA in constraint position as complex three-dimensional (3D) parts could be then easily processed as well. Under commercial aspects, the process design can be optimized to increase process efficiency and to reduce heat input during the welding process. Process optimization involves the determination of guidelines for PTA welding in constraint positions as well. Modeling the process gives an alternative to reduce the experimental effort to optimize the welding process. Results of simulation studies of the PTA welding process are given in the present work. It will be shown that coating conditions can be optimized by varying plasma gas flow, heat input and heat flow, process speed, or powder injection with regard to welding in constraint positions. The defined controlling of the PTA welding allows modification of process management with less experimental effort and to develop coating strategies for processing in different positions. In experimental investigations, the developed coating strategies are confirmed by producing PTA coatings in constraint position as well as complex 3D parts.

  18. Retalho de submucosa de intestino delgado autólogo para aumento da capacidade da bexiga: estudo experimental em cães

    Directory of Open Access Journals (Sweden)

    Fernando Hintz Greca

    Full Text Available OBJETIVO: Os procedimentos disponíveis para correção de lesões do trato urinário não são livres de complicações. Recentemente, uma nova opção tem sido investigada: o uso da submucosa de intestino delgado (SIS. Constituída de uma matriz extracelular que não apresenta tendências à rejeição, a SIS é capaz de permitir o crescimento de vasos sangüíneos, participar de processos de diferenciação celular e de ser resistente contra o desenvolvimento de processos infecciosos. O objetivo deste estudo foi avaliar a histocompatibilidade de um enxerto autólogo de submucosa de intestino delgado (SIS, quando utilizado para a ampliação da bexiga urinária. MÉTODO: Utilizaram-se oito cães adultos, pesando entre 10 e 15kg. Realizou-se laparotomia mediana e enterectomia de um segmento de jejuno de 10cm, localizado a 20cm da flexura duodeno-jejunal, seguida de anastomose terminoterminal. Desse segmento de intestino obteve-se, por dissecção, a camada submucosa. Após esvaziamento da bexiga por punção, fez-se uma incisão mediana de 3cm em sua parede, compreendendo todas as camadas. Um segmento de 3 x 2,5cm de SIS foi fixado às bordas da incisão com sutura contínua, laçada de fio absorvível 3.0 de poliglecaprone-25. No 30º dia de pós-operatório os animais foram submetidos à retirada da bexiga para estudo histopatológico. RESULTADOS: Não se observou reação inflamatória aguda. Reação inflamatória crônica esteve presente com graus discreto e moderado. A infiltração fibroblástica foi moderada. A presença de células gigantes de corpo estranho foi mínima. A epitelização foi satisfatória, não sendo completa em apenas um dos oito implantes. Ocorreu incorporação predominante de fibras colágenas tipo III, cuja média correspondeu a 70,7% do colágeno total. A reabsorção da mucosa foi moderada em 7/8 dos implantes. CONCLUSÃO: Os resultados indicam que ocorre regeneração da bexiga, quando é utilizada a submucosa

  19. Polipeptídeos farmacológicamente ativos e diâmetro de artérias piais: estudo experimental com vasopressina, ocitocina, bradicinina e neurocinina

    Directory of Open Access Journals (Sweden)

    Sylvio Saraiva

    1965-03-01

    Full Text Available A ação de quatro polipeptídeos farmacológicamente ativos (vasopressina, ocitocina, bradicinina e neurocinina sôbre as artérias piais foi estudada em cães anestesiados com pentobarbital sódico e preparados para o registro da pressão arterial. Utilizou-se a técnica de Forbes 25, modificada por Me-laragno37 que permite a visibilização, a fotografia e a mensuração dos referidos vasos. Foram feitas 24 experiências, divididas em 5 grupos de animais: um grupo foi utilizado como contrôle e os outros quatro para o estudo de cada uma das drogas acima referidas, administradas por via venosa. Os resultados obtidos conduziram às seguintes conclusões: 1 a vasopressina não determina variação significativa no diâmetro das artérias da pia-máter, embora tenha provocado irregulares variações da pressão arterial; 2 a ocitocina causa intensa vasoconstrição pial, de curta duração, sem contudo modificar essencialmente a pressão arterial sistêmica; 3 a bradicinina aumenta o diâmetro das artérias da pia-máter, em paralelismo com um efeito hipotensor sistêmico; 4 a neurocinina promove dilatação das artérias da pia-máter, independentemente de eventual variação da pressão arterial sistêmica.

  20. An efficient approach to bioconversion kinetic model generation based on automated microscale experimentation integrated with model driven experimental design

    DEFF Research Database (Denmark)

    Chen, B. H.; Micheletti, M.; Baganz, F.

    2009-01-01

    design. It incorporates a model driven approach to the experimental design that minimises the number of experiments to be performed, while still generating accurate values of kinetic parameters. The approach has been illustrated with the transketolase mediated asymmetric synthesis of L......Reliable models of enzyme kinetics are required for the effective design of bioconversion processes. Kinetic expressions of the enzyme-catalysed reaction rate however, are frequently complex and establishing accurate values of kinetic parameters normally requires a large number of experiments....... These can be both time consuming and expensive when working with the types of non-natural chiral intermediates important in pharmaceutical syntheses. This paper presents ail automated microscale approach to the rapid and cost effective generation of reliable kinetic models useful for bioconversion process...

  1. A DIDATIC EXPERIENCE IN BIOCHEMISTRY LABWORKS: THEORETICALVERSUS EXPERIMENTAL MODEL

    Directory of Open Access Journals (Sweden)

    B.C Rossi-Rodrigues

    2008-05-01

    Full Text Available Biochemistry labworks are fundamental to both the instrumentation and  for  the  establishment of important concepts. The labworks of Basic  Biochemistry  (BB280 for Biology students at UNICAMP have gone through several  improvements. The labworks are  now  structured  from simple  activities to more complex ones, and aimed  to  the student’s  autonomy  development  in the experiments planning and execution  over  the teaching  semester. The first practical activity is on buffer systems, and   it is based  on  the confrontation of a theoretical model with the  lab experiments results.  First of all, the students  simulate  a Titration  in  a computational environment, where students lay a theoretical model from their knowledge. In the theoretical model the buffer parameters are set according to the teacher instructions, and the experiment conditions are also set and tested.  The simulation results are used for planning  the experiment and to compare with the experimental ones.  After having the simulations concluded and having the experiment planned the students  perform  the  in lab  Titration with the parameters established in the simulation. The results obtained by students are presented in a report. We analyzed the reports from 76 BB280’s students in 2007(night class and day class. The students identified as the main causes of the discrepancy between theoretical and experimental data: 1 experimental errors, related to the lack of technical skill 2 limitation of equipment used 3 unexpected behavior of the substances  used. In addition to the theoretical content related to  labwork, the confrontation between the  simulation and experimentation provided the students with ability  to identify the main aspects of which can influence the quality of the data obtained.

  2. Astrocyte regulation of sleep circuits: experimental and modeling perspectives

    Directory of Open Access Journals (Sweden)

    Tommaso eFellin

    2012-08-01

    Full Text Available Integrated within neural circuits, astrocytes have recently been shown to modulate brain rhythms thought to mediate sleep function. Experimental evidence suggests that local impact of astrocytes on single synapses translates into global modulation of neuronal networks and behavior. We discuss these findings in the context of current conceptual models of sleep generation and function, each of which have historically focused on neural mechanisms. We highlight the implications and the challenges introduced by these results from a conceptual and computational perspective. We further provide modeling directions on how these data might extend our knowledge of astrocytic properties and sleep function. Given our evolving understanding of how local cellular activities during sleep lead to functional outcomes for the brain, further mechanistic and theoretical understanding of astrocytic contribution to these dynamics will undoubtedly be of great basic and translational benefit.

  3. An experimental and modeling study of n-octanol combustion

    KAUST Repository

    Cai, Liming

    2015-01-01

    This study presents the first investigation on the combustion chemistry of n-octanol, a long chain alcohol. Ignition delay times were determined experimentally in a high-pressure shock tube, and stable species concentration profiles were obtained in a jet stirred reactor for a range of initial conditions. A detailed kinetic model was developed to describe the oxidation of n-octanol at both low and high temperatures, and the model shows good agreement with the present dataset. The fuel\\'s combustion characteristics are compared to those of n-alkanes and to short chain alcohols to illustrate the effects of the hydroxyl moiety and the carbon chain length on important combustion properties. Finally, the results are discussed in detail. © 2014 The Combustion Institute.

  4. Experimental studies and modeling on concentration polarization in forward osmosis.

    Science.gov (United States)

    Qin, Jian-Jun; Chen, Sijie; Oo, Maung Htun; Kekre, Kiran A; Cornelissen, Emile R; Ruiken, Chris J

    2010-01-01

    Concentration polarization (CP) is an important issue in forward osmosis (FO) processes and it is believed that the coupled effect of dilutive internal CP (DICP) and concentrative external CP (CECP) limits FO flux. The objective of this study was to distinguish individual contribution of different types of DICP and CECP via modeling and to validate it by pilot studies. The influence of DICP/CECP on FO flux has been investigated in this study. The CP model presented in this work was derived from a previous study and evaluated by bench-scale FO experiments. Experiments were conducted with drinking water as the feed and NaCl/MgSO(4) as draw solutions at different concentrations and velocities. Modeling results indicated that DICP contributed to a flux reduction by 99.9% for 0.5 M NaCl as a draw solution although the flow pattern of both feed and draw solutions was turbulent. DICP could be improved via selection of the draw solution. The modeling results were well fit with the experimental data. It was concluded that the model could be used for selection of the draw solution and prediction of water flux under similar situation. A draw solution with greater diffusion coefficient or a thinner substrate of an asymmetric FO membrane resulted in a higher flux.

  5. Immunology and Homeopathy. 3. Experimental Studies on Animal Models

    Directory of Open Access Journals (Sweden)

    Paolo Bellavite

    2006-01-01

    Full Text Available A search of the literature and the experiments carried out by the authors of this review show that there are a number of animal models where the effect of homeopathic dilutions or the principles of homeopathic medicine have been tested. The results relate to the immunostimulation by ultralow doses of antigens, the immunological models of the ‘simile’, the regulation of acute or chronic inflammatory processes and the use of homeopathic medicines in farming. The models utilized by different research groups are extremely etherogeneous and differ as the test medicines, the dilutions and the outcomes are concerned. Some experimental lines, particularly those utilizing mice models of immunomodulation and anti-inflammatory effects of homeopathic complex formulations, give support to a real effect of homeopathic high dilutions in animals, but often these data are of preliminary nature and have not been independently replicated. The evidence emerging from animal models is supporting the traditional ‘simile’ rule, according to which ultralow doses of compounds, that in high doses are pathogenic, may have paradoxically a protective or curative effect. Despite a few encouraging observational studies, the effectiveness of the homeopathic prevention or therapy of infections in veterinary medicine is not sufficiently supported by randomized and controlled trials.

  6. Maternal hypothyroidism: An overview of current experimental models.

    Science.gov (United States)

    Ghanbari, Mahboubeh; Ghasemi, Asghar

    2017-10-15

    Maternal hypothyroidism (MH) is the most common cause of transient congenital hypothyroidism. Different animal models are used for assessing developmental effects of MH in offspring. The severity and status of hypothyroidism in animal models must be a reflection of the actual conditions in humans. To obtain comparable results with different clinical conditions, which lead to MH in humans, several factors have been suggested for researchers to consider before designing the experimental models. Regarding development of fetal body systems during pregnancy, interference at different times provides different results and the appropriate time for induction of hypothyroidism should be selected based on accurate time of development of the system under assessment. Other factors that should be taken into consideration include, physiological and biochemical differences between humans and other species, thyroid hormone-independent effects of anti-thyroid drugs, circadian rhythms in TSH secretion, sex differences, physical and psychological stress. This review addresses essential guidelines for selecting and managing the optimal animal model for MH as well as discussing the pros and cons of currently used models. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Antioxidant Capacity: Experimental Determination by EPR Spectroscopy and Mathematical Modeling.

    Science.gov (United States)

    Polak, Justyna; Bartoszek, Mariola; Chorążewski, Mirosław

    2015-07-22

    A new method of determining antioxidant capacity based on a mathematical model is presented in this paper. The model was fitted to 1000 data points of electron paramagnetic resonance (EPR) spectroscopy measurements of various food product samples such as tea, wine, juice, and herbs with Trolox equivalent antioxidant capacity (TEAC) values from 20 to 2000 μmol TE/100 mL. The proposed mathematical equation allows for a determination of TEAC of food products based on a single EPR spectroscopy measurement. The model was tested on the basis of 80 EPR spectroscopy measurements of herbs, tea, coffee, and juice samples. The proposed model works for both strong and weak antioxidants (TEAC values from 21 to 2347 μmol TE/100 mL). The determination coefficient between TEAC values obtained experimentally and TEAC values calculated with proposed mathematical equation was found to be R(2) = 0.98. Therefore, the proposed new method of TEAC determination based on a mathematical model is a good alternative to the standard EPR method due to its being fast, accurate, inexpensive, and simple to perform.

  8. An experimental methodology for a fuzzy set preference model

    Science.gov (United States)

    Turksen, I. B.; Willson, Ian A.

    1992-01-01

    models and vague linguistic preferences has greatly limited the usefulness and predictive validity of existing preference models. A fuzzy set preference model that uses linguistic variables and a fully interactive implementation should be able to simultaneously address these issues and substantially improve the accuracy of demand estimates. The parallel implementation of crisp and fuzzy conjoint models using identical data not only validates the fuzzy set model but also provides an opportunity to assess the impact of fuzzy set definitions and individual attribute choices implemented in the interactive methodology developed in this research. The generalized experimental tools needed for conjoint models can also be applied to many other types of intelligent systems.

  9. Contaminant plume configuration and movement: an experimental model

    Science.gov (United States)

    Alencoao, A.; Reis, A.; Pereira, M. G.; Liberato, M. L. R.; Caramelo, L.; Amraoui, M.; Amorim, V.

    2009-04-01

    The relevance of Science and Technology in our daily routines makes it compulsory to educate citizens who have both scientific literacy and scientific knowledge. These will allow them to be intervening citizens in a constantly changing society. Thus, physical and natural sciences are included in school curricula, both in primary and secondary education, with the fundamental aim of developing in the students the skills, attitudes and knowledge needed for the understanding of the planet Earth and its real problems. On the other hand, teaching in Geosciences is more and more based on practical methodologies which use didactic material, sustaining teachers' pedagogical practices and facilitating students' learning tasks suggested on the syllabus defined for each school level. Themes related to exploring the different components of the Hydrological Cycle and themes related to natural environment protection and preservation, namely water resources and soil contamination by industrial and urban sewage are examples of subject matters included on the Portuguese syllabus. These topics motivated the conception and construction of experimental models for the study of the propagation of pollutants on a porous medium. The experimental models allow inducing a horizontal flux of water though different kinds of permeable substances (e.g. sand, silt), with contamination spots on its surface. These experimental activities facilitate the student to understand the flow path of contaminating substances on the saturated zone and to observe the contaminant plume configuration and movement. The activities are explored in a teaching and learning process perspective where the student builds its own knowledge through real question- problem based learning which relate Science, Technology and Society. These activities have been developed in the framework of project ‘Water in the Environment' (CV/PVI/0854) of the POCTI Program (Programa Operacional "Ciência, Tecnologia, Inovação") financed

  10. Taenia solium: Development of an Experimental Model of Porcine Neurocysticercosis.

    Science.gov (United States)

    Fleury, Agnès; Trejo, Armando; Cisneros, Humberto; García-Navarrete, Roberto; Villalobos, Nelly; Hernández, Marisela; Villeda Hernández, Juana; Hernández, Beatriz; Rosas, Gabriela; Bobes, Raul J; de Aluja, Aline S; Sciutto, Edda; Fragoso, Gladis

    2015-01-01

    Human neurocysticercosis (NC) is caused by the establishment of Taenia solium larvae in the central nervous system. NC is a severe disease still affecting the population in developing countries of Latin America, Asia, and Africa. While great improvements have been made on NC diagnosis, treatment, and prevention, the management of patients affected by extraparenchymal parasites remains a challenge. The development of a T. solium NC experimental model in pigs that will allow the evaluation of new therapeutic alternatives is herein presented. Activated oncospheres (either 500 or 1000) were surgically implanted in the cerebral subarachnoid space of piglets. The clinical status and the level of serum antibodies in the animals were evaluated for a 4-month period after implantation. The animals were sacrificed, cysticerci were counted during necropsy, and both the macroscopic and microscopic characteristics of cysts were described. Based on the number of established cysticerci, infection efficiency ranged from 3.6% (1000 oncospheres) to 5.4% (500 oncospheres). Most parasites were caseous or calcified (38/63, 60.3%) and were surrounded by an exacerbated inflammatory response with lymphocyte infiltration and increased inflammatory markers. The infection elicited specific antibodies but no neurological signs. This novel experimental model of NC provides a useful tool to evaluate new cysticidal and anti-inflammatory approaches and it should improve the management of severe NC patients, refractory to the current treatments.

  11. Experimental Model of Intervertebral Disk Mediated Postoperative Epidural Fibrosis.

    Science.gov (United States)

    Larionov, Sergey N; Sorokovikov, V A; Erdyneyev, K C; Lepekhova, S A; Goldberg, O A

    2016-07-01

    Postoperative epidural fibrosis (EF) after lumbar discectomy is the most common and at the same time controversial issue. The etiology and pathogenesis creates a lot of discussion and selection of methods of treatment and prevention continues. LIV laminectomy with dura mater (DM) exposition was done in 24 rats, and then, 0.3 ml of elements of suspension of autologous intervertebral disk was implicated on DM. As autologous intervertebral disk, we used the intervertebral disk from amputated tail. In all the animals, incisions were closed with 3/0 Vicryl. EF was examined. Fibroblast cell density was calculated in each field at ×40 magnification: Grade 1 - fewer than 100 fibroblasts in each field; Grade 2 - 100-150 fibroblasts in each field; Grade 3 - more than 150 fibroblasts in each field. Based on histological results, we confirmed our model of experiment. On the 30th day of evaluation, there were significant histological evidences of postoperative epidural adhesions in experimental animals, which included the obliteration of epidural space, the presence of adhesions in the dura and nerve roots, the restructuring of the yellow ligament, bone sclerosis, excessive appearance of fibrous tissue around the autologous intervertebral disk tissue that applied on the DM. In our work, we describe a new experimental model, where the elements of autologous intervertebral disk play the role of inflammation trigger, which cause postoperative scar and EF.

  12. Experimental Investigation and Theoretical Modeling of Nanosilica Activity in Concrete

    Directory of Open Access Journals (Sweden)

    Han-Seung Lee

    2014-01-01

    Full Text Available This paper presents experimental investigations and theoretical modeling of the hydration reaction of nanosilica blended concrete with different water-to-binder ratios and different nanosilica replacement ratios. The developments of chemically bound water contents, calcium hydroxide contents, and compressive strength of Portland cement control specimens and nanosilica blended specimens were measured at different ages: 1 day, 3 days, 7 days, 14 days, and 28 days. Due to the pozzolanic reaction of nanosilica, the contents of calcium hydroxide in nanosilica blended pastes are considerably lower than those in the control specimens. Compared with the control specimens, the extent of compressive strength enhancement in the nanosilica blended specimens is much higher at early ages. Additionally, a blended cement hydration model that considers both the hydration reaction of cement and the pozzolanic reaction of nanosilica is proposed. The properties of nanosilica blended concrete during hardening were evaluated using the degree of hydration of cement and the reaction degree of nanosilica. The calculated chemically bound water contents, calcium hydroxide contents, and compressive strength were generally consistent with the experimental results.

  13. NADPH Oxidase-Related Pathophysiology in Experimental Models of Stroke

    Directory of Open Access Journals (Sweden)

    Hiroshi Yao

    2017-10-01

    Full Text Available Several experimental studies have indicated that nicotinamide adenine dinucleotide phosphate (NADPH oxidases (Nox exert detrimental effects on ischemic brain tissue; Nox-knockout mice generally exhibit resistance to damage due to experimental stroke following middle cerebral artery occlusion (MCAO. Furthermore, our previous MCAO study indicated that infarct size and blood-brain barrier breakdown are enhanced in mice with pericyte-specific overexpression of Nox4, relative to levels observed in controls. However, it remains unclear whether Nox affects the stroke outcome directly by increasing oxidative stress at the site of ischemia, or indirectly by modifying physiological variables such as blood pressure or cerebral blood flow (CBF. Because of technical problems in the measurement of physiological variables and CBF, it is often difficult to address this issue in mouse models due to their small body size; in our previous study, we examined the effects of Nox activity on focal ischemic injury in a novel congenic rat strain: stroke-prone spontaneously hypertensive rats with loss-of-function in Nox. In this review, we summarize the current literature regarding the role of Nox in focal ischemic injury and discuss critical issues that should be considered when investigating Nox-related pathophysiology in animal models of stroke.

  14. Experimental model of distraction osteogenesis in edentulous rats

    Directory of Open Access Journals (Sweden)

    Maria Montserrat Pujadas Bigi

    2011-06-01

    Full Text Available Distraction osteogenesis (DO is a surgical technique producing bone lengthening by distraction of the fracture callus. Although a large number of experimental studies on the events associated with DO of craniofacial skeleton have been reported, the few employing rat mandibular bone DO used complicated designs and produced a small volume of newly formed bone. Thus, this study aims to present an original experimental model of mandibular DO in edentulous rats that produces a sufficient quantity and quality of intramembranous bone. Eight male Wistar rats, weighing 75 g, underwent extraction of lower molars. With rats weighing 350 g, right mandibular osteotomy was performed and the distraction device was placed. The distraction device was custom made using micro-implants, expansion screws, and acrylic resin. Study protocol: latency: 6 days, distraction: ¼ turn (0.175 mm once a day during 6 d, consolidation: 28 d after distraction phase, sacrifice. DO-treated and contralateral hemimandibles were dissected and compared macroscopically and using radiographic studies. Histological sections were obtained and stained with H&E. A distraction gap filled with newly formed and mature bone tissue was obtained. This model of mandibular DO proved useful to obtain adequate quantity and quality of bone to study bone regeneration.

  15. Sparse linear models: Variational approximate inference and Bayesian experimental design

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, Matthias W [Saarland University and Max Planck Institute for Informatics, Campus E1.4, 66123 Saarbruecken (Germany)

    2009-12-01

    A wide range of problems such as signal reconstruction, denoising, source separation, feature selection, and graphical model search are addressed today by posterior maximization for linear models with sparsity-favouring prior distributions. The Bayesian posterior contains useful information far beyond its mode, which can be used to drive methods for sampling optimization (active learning), feature relevance ranking, or hyperparameter estimation, if only this representation of uncertainty can be approximated in a tractable manner. In this paper, we review recent results for variational sparse inference, and show that they share underlying computational primitives. We discuss how sampling optimization can be implemented as sequential Bayesian experimental design. While there has been tremendous recent activity to develop sparse estimation, little attendance has been given to sparse approximate inference. In this paper, we argue that many problems in practice, such as compressive sensing for real-world image reconstruction, are served much better by proper uncertainty approximations than by ever more aggressive sparse estimation algorithms. Moreover, since some variational inference methods have been given strong convex optimization characterizations recently, theoretical analysis may become possible, promising new insights into nonlinear experimental design.

  16. UM ESTUDO EXPERIMENTAL SOBRE OS EFEITOS DA PROPAGANDA NA INTENÇÃO DE USO DE SERVIÇOS DE PERSONAL TRAINER

    National Research Council Canada - National Science Library

    Verônica de Oliveira-Lopes; Ary José Rocco; Evandro Luiz Lopes

    2017-01-01

    ...: one with high level of physical hypertrophy and the other with a conditioned body. Along with the manipulation of the biotype of the models, the expressive actions of the models were also manipulated...

  17. Application of Iterative Robust Model-based Optimal Experimental Design for the Calibration of Biocatalytic Models

    DEFF Research Database (Denmark)

    Van Daele, Timothy; Gernaey, Krist V.; Ringborg, Rolf Hoffmeyer

    2017-01-01

    The aim of model calibration is to estimate unique parameter values from available experimental data, here applied to a biocatalytic process. The traditional approach of first gathering data followed by performing a model calibration is inefficient, since the information gathered during...... experimentation is not actively used to optimise the experimental design. By applying an iterative robust model-based optimal experimental design, the limited amount of data collected is used to design additional informative experiments. The algorithm is used here to calibrate the initial reaction rate of an ω......-transaminase catalysed reaction in a more accurate way. The parameter confidence region estimated from the Fisher Information Matrix is compared with the likelihood confidence region, which is a more accurate, but also a computationally more expensive method. As a result, an important deviation between both approaches...

  18. ESTUDO EXPERIMENTAL DAS PROPRIEDADES FÍSICAS DE ARGAMASSAS COM ADIÇÃO DE RESÍDUOS DE CERÂMICAS VERMELHAS RECICLADAS

    Directory of Open Access Journals (Sweden)

    Bruno Silva Mendes

    2008-05-01

    Full Text Available O uso de argamassas como meio de reciclagem materiais orgânico e inorgânicos não é de hoje. Vários estudos já foram realizados nesta área, já que a sociedade e a indústria da construção civil estão sempre procurando desenvolver novas tecnologias. Tendo em vista essa visão que este trabalho foi desenvolvido, propondo analisar as propriedades físicas de argamassas de revestimento de alvenaria produzidas a partir de diferentes proporções de resíduos de cerâmicas vermelhas recicladas (RCV através do processo de trituração, objetivando, assim, a redução dos custos de produção e da quantidade desses resíduos descartados no ambiente. Para se realizar a proposta estabelecida, os seguintes pontos foram destacados como objetivos principais: determinação das proporções otimizadas do “novo composto” de forma a se enquadrar nos parâmetros normativos em vigor referente às argamassas; analisar o comportamento do resíduo de cerâmica vermelha reciclada como agregado miúdo em argamassa de assentamento e/ou revestimento no que diz respeito as suas propriedades físicas; identificar a influência da quantidade de resíduos de cerâmicas vermelhas nas quatro proporções previamente estabelecidas (5%, 10%, 15% e 20% em substituição ao agregado miúdo (cal mantendo-se o mesmo fator água / cimento. Para tanto, foram realizados ensaios no estado fresco (índice de consistência, teor de ar incorporado e densidade de massa fluida. Os resultados demonstraram que a presença do RCV na argamassa aumenta o índice de consistência e o teor de ar incorporado e reduz a densidade de massa. As propriedades físicas das argamassas no estado fresco são otimizadas coma a adição do RCV. Palavras-chave: reciclagem, RCV, argamassa.

  19. Alteração do tecido conjuntivo orbitário após aplicação de bimatoprost: estudo experimental em ratos

    Directory of Open Access Journals (Sweden)

    Nilson Lopes da Fonseca Junior

    Full Text Available RESUMO O bimatoprost é utilizado comumente como a droga de primeira escolha no tratamento do glaucoma primário de ângulo aberto. Hiperemia conjuntival, crescimento dos cílios, enoftalmia, escurecimento cutâneo periocular, sulco palpebral profundo e prurido ocular têm sido relatados em pacientes que receberam bimatoprost em doses únicas diárias durante cerca de 3 meses. O mecanismo exato para estes efeitos adversos permanece desconhecido. Objetivo: Verificar em animais de experimentação, as alterações do tecido conjuntivo orbitário após injeção retrobulbar de bimatoprost 0,03%. Métodos Foram utilizados trinta e seis ratos machos (Rattus norvegicus albinus submetidos a diferentes períodos de injeção retrobulbar de bimatoprost à direita. O material exenterado foi submetido à análise histológica, morfométrica (diâmetro, densidade numérica e densidade de volume dos adipócitos e imunohistoquímica para marcação do VEGF. Os resultados destas análises foram submetidos à análise descritiva com o auxílio do software R. O nível de significância adotado foi 5%. Para as comparações foi proposto o modelo de regressão linear com efeitos mistos. Resultados: Na amostra estudada, as órbitas submetidas a injeções retrobulbares de bimatoprost apresentaram ao redor do nervo óptico tecido conjuntivo mais espesso, com inúmeros capilares e vasos de vários calibres e a redução da quantidade, diâmetro e volume das células adiposas estatisticamente significativo quando comparado à órbita contralateral e ao grupo controle. Conclusão: Neste estudo observaram-se as seguintes alterações potencialmente reversíveis do tecido conjuntivo orbitário nos ratos submetidos à injeção retrobulbar de bimatoprost: 1 redução da quantidade, do diâmetro e do volume das células adiposas orbitárias; 2 neovascularização local; 3 espessamento e remodelamento das fibras de colágeno na cavidade orbitária.

  20. Integral Reactor Containment Condensation Model and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiao [Oregon State Univ., Corvallis, OR (United States); Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States)

    2016-05-02

    This NEUP funded project, NEUP 12-3630, is for experimental, numerical and analytical studies on high-pressure steam condensation phenomena in a steel containment vessel connected to a water cooling tank, carried out at Oregon State University (OrSU) and the University of Wisconsin at Madison (UW-Madison). In the three years of investigation duration, following the original proposal, the planned tasks have been completed: (1) Performed a scaling study for the full pressure test facility applicable to the reference design for the condensation heat transfer process during design basis accidents (DBAs), modified the existing test facility to route the steady-state secondary steam flow into the high pressure containment for controllable condensation tests, and extended the operations at negative gage pressure conditions (OrSU). (2) Conducted a series of DBA and quasi-steady experiments using the full pressure test facility to provide a reliable high pressure condensation database (OrSU). (3) Analyzed experimental data and evaluated condensation model for the experimental conditions, and predicted the prototypic containment performance under accidental conditions (UW-Madison). A film flow model was developed for the scaling analysis, and the results suggest that the 1/3 scaled test facility covers large portion of laminar film flow, leading to a lower average heat transfer coefficient comparing to the prototypic value. Although it is conservative in reactor safety analysis, the significant reduction of heat transfer coefficient (50%) could under estimate the prototypic condensation heat transfer rate, resulting in inaccurate prediction of the decay heat removal capability. Further investigation is thus needed to quantify the scaling distortion for safety analysis code validation. Experimental investigations were performed in the existing MASLWR test facility at OrST with minor modifications. A total of 13 containment condensation tests were conducted for pressure

  1. Toxin-Induced Experimental Models of Learning and Memory Impairment.

    Science.gov (United States)

    More, Sandeep Vasant; Kumar, Hemant; Cho, Duk-Yeon; Yun, Yo-Sep; Choi, Dong-Kug

    2016-09-01

    Animal models for learning and memory have significantly contributed to novel strategies for drug development and hence are an imperative part in the assessment of therapeutics. Learning and memory involve different stages including acquisition, consolidation, and retrieval and each stage can be characterized using specific toxin. Recent studies have postulated the molecular basis of these processes and have also demonstrated many signaling molecules that are involved in several stages of memory. Most insights into learning and memory impairment and to develop a novel compound stems from the investigations performed in experimental models, especially those produced by neurotoxins models. Several toxins have been utilized based on their mechanism of action for learning and memory impairment such as scopolamine, streptozotocin, quinolinic acid, and domoic acid. Further, some toxins like 6-hydroxy dopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and amyloid-β are known to cause specific learning and memory impairment which imitate the disease pathology of Parkinson's disease dementia and Alzheimer's disease dementia. Apart from these toxins, several other toxins come under a miscellaneous category like an environmental pollutant, snake venoms, botulinum, and lipopolysaccharide. This review will focus on the various classes of neurotoxin models for learning and memory impairment with their specific mechanism of action that could assist the process of drug discovery and development for dementia and cognitive disorders.

  2. Toxin-Induced Experimental Models of Learning and Memory Impairment

    Directory of Open Access Journals (Sweden)

    Sandeep Vasant More

    2016-09-01

    Full Text Available Animal models for learning and memory have significantly contributed to novel strategies for drug development and hence are an imperative part in the assessment of therapeutics. Learning and memory involve different stages including acquisition, consolidation, and retrieval and each stage can be characterized using specific toxin. Recent studies have postulated the molecular basis of these processes and have also demonstrated many signaling molecules that are involved in several stages of memory. Most insights into learning and memory impairment and to develop a novel compound stems from the investigations performed in experimental models, especially those produced by neurotoxins models. Several toxins have been utilized based on their mechanism of action for learning and memory impairment such as scopolamine, streptozotocin, quinolinic acid, and domoic acid. Further, some toxins like 6-hydroxy dopamine (6-OHDA, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP and amyloid-β are known to cause specific learning and memory impairment which imitate the disease pathology of Parkinson’s disease dementia and Alzheimer’s disease dementia. Apart from these toxins, several other toxins come under a miscellaneous category like an environmental pollutant, snake venoms, botulinum, and lipopolysaccharide. This review will focus on the various classes of neurotoxin models for learning and memory impairment with their specific mechanism of action that could assist the process of drug discovery and development for dementia and cognitive disorders.

  3. Mass spectrometry analysis of hepcidin peptides in experimental mouse models.

    Science.gov (United States)

    Tjalsma, Harold; Laarakkers, Coby M M; van Swelm, Rachel P L; Theurl, Milan; Theurl, Igor; Kemna, Erwin H; van der Burgt, Yuri E M; Venselaar, Hanka; Dutilh, Bas E; Russel, Frans G M; Weiss, Günter; Masereeuw, Rosalinde; Fleming, Robert E; Swinkels, Dorine W

    2011-03-08

    The mouse is a valuable model for unravelling the role of hepcidin in iron homeostasis, however, such studies still report hepcidin mRNA levels as a surrogate marker for bioactive hepcidin in its pivotal function to block ferroportin-mediated iron transport. Here, we aimed to assess bioactive mouse Hepcidin-1 (Hep-1) and its paralogue Hepcidin-2 (Hep-2) at the peptide level. To this purpose, Fourier transform ion cyclotron resonance (FTICR) and tandem-MS was used for hepcidin identification, after which a time-of-flight (TOF) MS-based methodology was exploited to routinely determine Hep-1 and -2 levels in mouse serum and urine. This method was biologically validated by hepcidin assessment in: i) 3 mouse strains (C57Bl/6; DBA/2 and BABL/c) upon stimulation with intravenous iron and LPS, ii) homozygous Hfe knock out, homozygous transferrin receptor 2 (Y245X) mutated mice and double affected mice, and iii) mice treated with a sublethal hepatotoxic dose of paracetamol. The results showed that detection of Hep-1 was restricted to serum, whereas Hep-2 and its presumed isoforms were predominantly present in urine. Elevations in serum Hep-1 and urine Hep-2 upon intravenous iron or LPS were only moderate and varied considerably between mouse strains. Serum Hep-1 was decreased in all three hemochromatosis models, being lowest in the double affected mice. Serum Hep-1 levels correlated with liver hepcidin-1 gene expression, while acute liver damage by paracetamol depleted Hep-1 from serum. Furthermore, serum Hep-1 appeared to be an excellent indicator of splenic iron accumulation. In conclusion, Hep-1 and Hep-2 peptide responses in experimental mouse agree with the known biology of hepcidin mRNA regulators, and their measurement can now be implemented in experimental mouse models to provide novel insights in post-transcriptional regulation, hepcidin function, and kinetics.

  4. Mass spectrometry analysis of hepcidin peptides in experimental mouse models.

    Directory of Open Access Journals (Sweden)

    Harold Tjalsma

    Full Text Available The mouse is a valuable model for unravelling the role of hepcidin in iron homeostasis, however, such studies still report hepcidin mRNA levels as a surrogate marker for bioactive hepcidin in its pivotal function to block ferroportin-mediated iron transport. Here, we aimed to assess bioactive mouse Hepcidin-1 (Hep-1 and its paralogue Hepcidin-2 (Hep-2 at the peptide level. To this purpose, Fourier transform ion cyclotron resonance (FTICR and tandem-MS was used for hepcidin identification, after which a time-of-flight (TOF MS-based methodology was exploited to routinely determine Hep-1 and -2 levels in mouse serum and urine. This method was biologically validated by hepcidin assessment in: i 3 mouse strains (C57Bl/6; DBA/2 and BABL/c upon stimulation with intravenous iron and LPS, ii homozygous Hfe knock out, homozygous transferrin receptor 2 (Y245X mutated mice and double affected mice, and iii mice treated with a sublethal hepatotoxic dose of paracetamol. The results showed that detection of Hep-1 was restricted to serum, whereas Hep-2 and its presumed isoforms were predominantly present in urine. Elevations in serum Hep-1 and urine Hep-2 upon intravenous iron or LPS were only moderate and varied considerably between mouse strains. Serum Hep-1 was decreased in all three hemochromatosis models, being lowest in the double affected mice. Serum Hep-1 levels correlated with liver hepcidin-1 gene expression, while acute liver damage by paracetamol depleted Hep-1 from serum. Furthermore, serum Hep-1 appeared to be an excellent indicator of splenic iron accumulation. In conclusion, Hep-1 and Hep-2 peptide responses in experimental mouse agree with the known biology of hepcidin mRNA regulators, and their measurement can now be implemented in experimental mouse models to provide novel insights in post-transcriptional regulation, hepcidin function, and kinetics.

  5. Mass Spectrometry Analysis of Hepcidin Peptides in Experimental Mouse Models

    Science.gov (United States)

    van Swelm, Rachel P. L.; Theurl, Milan; Theurl, Igor; Kemna, Erwin H.; van der Burgt, Yuri E. M.; Venselaar, Hanka; Dutilh, Bas E.; Russel, Frans G. M.; Weiss, Günter; Masereeuw, Rosalinde; Fleming, Robert E.; Swinkels, Dorine W.

    2011-01-01

    The mouse is a valuable model for unravelling the role of hepcidin in iron homeostasis, however, such studies still report hepcidin mRNA levels as a surrogate marker for bioactive hepcidin in its pivotal function to block ferroportin-mediated iron transport. Here, we aimed to assess bioactive mouse Hepcidin-1 (Hep-1) and its paralogue Hepcidin-2 (Hep-2) at the peptide level. To this purpose, fourier transform ion cyclotron resonance (FTICR) and tandem-MS was used for hepcidin identification, after which a time-of-flight (TOF) MS-based methodology was exploited to routinely determine Hep-1 and -2 levels in mouse serum and urine. This method was biologically validated by hepcidin assessment in: i) 3 mouse strains (C57Bl/6; DBA/2 and BABL/c) upon stimulation with intravenous iron and LPS, ii) homozygous Hfe knock out, homozygous transferrin receptor 2 (Y245X) mutated mice and double affected mice, and iii) mice treated with a sublethal hepatotoxic dose of paracetamol. The results showed that detection of Hep-1 was restricted to serum, whereas Hep-2 and its presumed isoforms were predominantly present in urine. Elevations in serum Hep-1 and urine Hep-2 upon intravenous iron or LPS were only moderate and varied considerably between mouse strains. Serum Hep-1 was decreased in all three hemochromatosis models, being lowest in the double affected mice. Serum Hep-1 levels correlated with liver hepcidin-1 gene expression, while acute liver damage by paracetamol depleted Hep-1 from serum. Furthermore, serum Hep-1 appeared to be an excellent indicator of splenic iron accumulation. In conclusion, Hep-1 and Hep-2 peptide responses in experimental mouse agree with the known biology of hepcidin mRNA regulators, and their measurement can now be implemented in experimental mouse models to provide novel insights in post-transcriptional regulation, hepcidin function, and kinetics. PMID:21408141

  6. Experimental model of ultrasound thermotherapy in rats inoculated with Walker-236 tumor Modelo experimental de termoterapia ultrassônica em ratos inoculados com tumor de Walker-236

    Directory of Open Access Journals (Sweden)

    José Antonio Carlos Otaviano David Morano

    2011-01-01

    Full Text Available PURPOSE: To develop a model to evaluate the effects of focal pulsed ultrasound (US waves as a source of heat for treatment of murine subcutaneous implanted Walker tumor. METHODS: An experimental, controlled, comparative study was conducted. Twenty male Wistar rats (160-300 g randomized in 2 equal groups (G-1: Control and G-2: Hyperthermia were inoculated with Walker-256 carcinosarcoma tumor. After 5 days G-2 rats were submitted to 45ºC hyperthermia. Heat was delivered directly to the tumor by an ultrasound (US equipment (3 MHz frequency, 1,5W/cm³. Tumor temperature reached 45º C in 3 minutes and was maintained at this level for 5 minutes. Tumor volume was measured on days 5, 8, 11, 14 e 17 post inoculation in both groups. Unpaired t-test was used for comparison. POBJETIVO: Desenvolver um modelo para avaliar os efeitos do ultra-som focal pulsado como fonte de calor para o tratamento de tumores de Walker subcutâneos implantados em ratos. MÉTODOS: Um estudo experimental, controlado, comparativo foi realizado. Vinte ratos Wistar machos (160-300 g divididos em dois grupos (G-1: Controle e G-2: hipertermia foram inoculados com tumor de Walker carcinossarcoma-256. Após cinco dias os ratos do grupo G-2 ratos foram submetidos a hipertermia (45ºC. O calor foi aplicado diretamente no tumor por um equipamento de ultrassonografia (3 MHz, 1,5 W/cm³. A temperatura no tumor atingiu 45ºC em 3 minutos e foi mantida nesse nível por 5 minutos. O volume do tumor foi medido nos dias 5, 8, 11, 14 e 17 após a inoculação, em ambos os grupos. Teste t não pareado foi utilizado para comparação. P <0,05 foi considerado significante. RESULTADOS: O volume do tumor foi significativamente maior no 5º dia e diminuiu nos dias 11, 14 e 17 nos ratos tratados. Animais submetidos à hipertermia sobreviveram mais tempo que os animais do grupo controle. No 29º dia após a inoculação do tumor, 40% dos ratos do grupo controle e 77,78% dos ratos tratados com

  7. Estudo de propriedades físico-químicas envolvidas no processo de compactação de uma formulação experimental contendo zidovudina

    Directory of Open Access Journals (Sweden)

    Tatiana Angiolucci

    2012-04-01

    Full Text Available Estudo das propriedades físico-químicas envolvidos no processo de compactação de uma formulação experimental contendo como fármaco modelo a zidovudina. O objetivo foi caracterizar o comportamento físico-químico de comprimidos produzidos por compressão direta usando-se diferentes pressões de compactação. Nas análises foram empregadas metodologias convencionais e não convencionais. A metodologia não convencional foi o uso da técnica da atenuação de raios-gama na determinação da porosidade. As metodologias convencionais utilizadas foram os testes de friabilidade, dureza e dissolução. Os modelos teóricos utilizados para explicar o comportamento físico-químico da formulação sob compressão são os proposto por Heckel e Walker. Os estudos mostraram que o processo de densificação é governado principalmente por deformações do tipo plásticas e pressões em torno de 246MPa são suficientes para induzir deformação plástica e consolidação do sistema compactado. Os resultados da análise de Walker indicam que a formulação tem propriedades de compressão que podem ser melhoradas.

  8. Predicting subsurface uranium transport: Mechanistic modeling constrained by experimental data

    Science.gov (United States)

    Ottman, Michael; Schenkeveld, Walter D. C.; Kraemer, Stephan

    2017-04-01

    Depleted uranium (DU) munitions and their widespread use throughout conflict zones around the world pose a persistent health threat to the inhabitants of those areas long after the conclusion of active combat. However, little emphasis has been put on developing a comprehensive, quantitative tool for use in remediation and hazard avoidance planning in a wide range of environments. In this context, we report experimental data on U interaction with soils and sediments. Here, we strive to improve existing risk assessment modeling paradigms by incorporating a variety of experimental data into a mechanistic U transport model for subsurface environments. 20 different soils and sediments from a variety of environments were chosen to represent a range of geochemical parameters that are relevant to U transport. The parameters included pH, organic matter content, CaCO3, Fe content and speciation, and clay content. pH ranged from 3 to 10, organic matter content from 6 to 120 g kg-1, CaCO3 from 0 to 700 g kg-1, amorphous Fe content from 0.3 to 6 g kg-1 and clay content from 4 to 580 g kg-1. Sorption experiments were then performed, and linear isotherms were constructed. Sorption experiment results show that among separate sets of sediments and soils, there is an inverse correlation between both soil pH and CaCO¬3 concentration relative to U sorptive affinity. The geological materials with the highest and lowest sorptive affinities for U differed in CaCO3 and organic matter concentrations, as well as clay content and pH. In a further step, we are testing if transport behavior in saturated porous media can be predicted based on adsorption isotherms and generic geochemical parameters, and comparing these modeling predictions with the results from column experiments. The comparison of these two data sets will examine if U transport can be effectively predicted from reactive transport modeling that incorporates the generic geochemical parameters. This work will serve to show

  9. Evaluation of two experimental models of hepatic encephalopathy in rats

    Directory of Open Access Journals (Sweden)

    L.M. García-Moreno

    2005-01-01

    Full Text Available The serious neuropsychological repercussions of hepatic encephalopathy have led to the creation of several experimental models in order to better understand the pathogenesis of the disease. In the present investigation, two possible causes of hepatic encephalopathy, cholestasis and portal hypertension, were chosen to study the behavioral impairments caused by the disease using an object recognition task. This working memory test is based on a paradigm of spontaneous delayed non-matching to sample and was performed 60 days after surgery. Male Wistar rats (225-250 g were divided into three groups: two experimental groups, microsurgical cholestasis (N = 20 and extrahepatic portal hypertension (N = 20, and a control group (N = 20. A mild alteration of the recognition memory occurred in rats with cholestasis compared to control rats and portal hypertensive rats. The latter group showed the poorest performance on the basis of the behavioral indexes tested. In particular, only the control group spent significantly more time exploring novel objects compared to familiar ones (P < 0.001. In addition, the portal hypertension group spent the shortest time exploring both the novel and familiar objects (P < 0.001. These results suggest that the existence of portosystemic collateral circulation per se may be responsible for subclinical encephalopathy.

  10. Tesla Coil Theoretical Model and its Experimental Verification

    Directory of Open Access Journals (Sweden)

    Voitkans Janis

    2014-12-01

    Full Text Available In this paper a theoretical model of Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wire form, where the line voltage is measured across electrically neutral space. By applying the principle of equivalence of single-wire and two-wire schemes an equivalent two-wire scheme can be found for a single-wire scheme and the already known long line theory can be applied to the Tesla coil. A new method of multiple reflections is developed to characterize a signal in a long line. Formulas for calculation of voltage in Tesla coil by coordinate and calculation of resonance frequencies are proposed. The theoretical calculations are verified experimentally. Resonance frequencies of Tesla coil are measured and voltage standing wave characteristics are obtained for different output capacities in the single-wire mode. Wave resistance and phase coefficient of Tesla coil is obtained. Experimental measurements show good compliance with the proposed theory. The formulas obtained in this paper are also usable for a regular two-wire long line with distributed parameters.

  11. Modelling concentration-analgesia relationships for morphine to evaluate experimental pain models

    DEFF Research Database (Denmark)

    Sverrisdóttir, Eva; Foster, David John Richard; Upton, Richard Neil

    2015-01-01

    -blind, placebo-controlled, crossover study, 39 healthy volunteers received an oral dose of 30 mg morphine hydrochloride or placebo. Non-linear mixed effects modelling was used to describe the plasma concentrations of morphine and metabolites, and the analgesic effect of morphine on experimental pain in skin......The aim of this study was to develop population pharmacokinetic-pharmacodynamic models for morphine in experimental pain induced by skin heat and muscle pressure, and to evaluate the experimental pain models with regard to assessment of morphine pharmacodynamics. In a randomized, double...... and muscle. Baseline pain metrics varied between individuals and occasions, and were described with interindividual and interoccasion variability. Placebo-response did not change with time. For both pain metrics, morphine effect was proportional to baseline pain and was described with a linear model...

  12. Retalho venoso unipediculado transposto comparado ao não transposto: estudo experimental em coelhos Evaluation of unipediculated venous flap with and without transposition

    Directory of Open Access Journals (Sweden)

    Alfredo Benjamim Duarte da Silva

    2000-01-01

    Full Text Available Retalhos venosos são aqueles que apresentam em seu pedículo apenas uma veia, diferente dos retalhos convencionais que são caracterizados por entrada de sangue arterial e saída de sangue venoso. O objetivo deste trabalho foi determinar se a transposição do retalho venoso unipediculado modifica a sua área de sobrevida e vascularização. As orelhas de oito coelhos foram submetidas à realização de retalhos venosos. Dissecou-se um retalho de pele de dois por dois centímetros baseado no pedículo distal da veia marginal anterior. Os retalhos foram divididos em dois grupos: no grupo I(n=8, os retalhos venosos foram levantados e suturados na mesma posição; no grupo II (n=8, os retalhos foram levantados e transpostos 90 graus. Estes dois grupos foram comparados entre si e ao grupo III(n=8, no qual foi realizado enxerto de pele com subcutâneo sobre um leito bem vascularizado. A área média de necrose no grupo I (6,5% foi significativamente menor que no grupo II (43,75%, e as áreas de necrose dos grupos I e II foram significativamente menor do que no grupo III (88,75%. O estudo angiográfico não mostrou alterações no padrão vascular comparando-se os grupos I e II. A veia marginal anterior foi importante para a sobrevida do retalho. Houve uma maior área de necrose do grupo II, em que foi realizada transposição, em relação ao grupo I.Conventional flaps are caracterized by arterial blood inflow and venous blood outflow. Venous flaps have only one vein in their pedicle. Determination of survival area and vascularization in transpositioned venous flaps is the aim of this study. A 2x2 cm² skin flap, based in the distal pedicle of anterior marginal vein, was performed in 8 rabbits ears. The flaps were divided in two groups: group I (n=8-the flaps were elevated are fixated in the same position.; group II (n=8-the flaps were elevated and transpositioned in 90°. These two groups were compared in between and with group III (n=8, in which

  13. Exclusão gastroduodenal e vagotomia troncular: repercussão no peso corporal e gastrinemia- estudo experimental em ratos

    Directory of Open Access Journals (Sweden)

    Pedro Luiz Squilacci Leme

    Full Text Available OBJETIVO: A obesidade mórbida é uma doença crônica que se acompanha de várias complicações médicas e de uma menor esperança de vida, prejudicando o aspecto físico, emocional, econômico e social. As pesquisas clínicas e experimentais são amplamente justificadas nesta doença, considerando-se que a opção de tratamento operatório é recente. As gastroplastias e as derivações gástricas são algumas das modalidades terapêuticas propostas e produzem uma grande câmara gástrica remanescente, que em algumas técnicas fica totalmente excluída do trânsito alimentar. As possíveis alterações deste segmento, transformado em apêndice do sistema digestório, representam um vasto campo para pesquisa. Tivemos como objetivo avaliar o peso e as alterações da dosagem de gastrina sérica do rato, após denervação vagal troncular subdiafragmática, com exclusão da câmara gástrica e duodeno do trânsito alimentar do animal. MÉTODO: Foi realizada vagotomia troncular e exclusão gastroduodenal em cem ratos, dos quais trinta puderam ser estudados. Eram ratos machos adultos (Rattus Norvegicus Albinus, da linhagem Wistar, com peso médio de 378,67 g. Este estudo foi complementado pela dosagem sérica de gastrina por radioimunoensaio com I125 e duplo anticorpo para gastrina. RESULTADOS: O peso de todos os ratos estudados diminuiu em média de 378,67 g para 285,83 g. Os trinta animais perderam em média 92,83 g (-24,52%. Houve diferenças significativas entre o peso inicial dos animais e o peso final (p< 0,001. A gastrina sérica também diminuiu em vinte e um dos trinta ratos operados, caindo de 59,68 pg/ml para 46,77 pg/ml em média, correspondendo a uma diminuição de 12,91 pg (-19,73% entre as duas médias (p< 0,001. A análise estatística teve como objetivo avaliar se houve diminuição nas médias das variáveis: peso e gastrina, medidas antes e depois da operação proposta. Para avaliar as diferenças entre as médias, utilizou

  14. A molecular machine biosensor: construction, predictive models and experimental studies.

    Science.gov (United States)

    Moradi-Monfared, Sahar; Krishnamurthy, Vikram; Cornell, Bruce

    2012-04-15

    This paper describes the construction, operation and predictive modeling of a molecular machine, functioning as a high sensitivity biosensor. Embedded gramicidin A (gA) ionchannels in a self-assembled tethered lipid bilayer act as biological switches in response to target molecules and provide a signal amplification mechanism that results in high sensitivity molecular detection. The biosensor can be used as a rapid and sensitive point of care diagnostic device in different media such as human serum, plasma and whole blood without the need for pre and post processing steps required in an enzyme-linked immunosorbent assay. The electrical reader of the device provides the added advantage of objective measurement. Novel ideas in the construction of the molecular machine, including fabrication of biochip arrays, and experimental studies of its ability to detect analyte molecules over a wide range of concentrations are presented. Remarkably, despite the complexity of the device, it is shown that the response can be predicted by modeling the analyte fluid flow and surface chemical reactions. The derived predictive models for the sensing dynamics also facilitate determining important variables in the design of a molecular machine such as the ion channel lifetime and diffusion dynamics within the bilayer lipid membrane as well as the bio-molecular interaction rate constants. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Thermal infrared spectroscopy and modeling of experimentally shocked basalts

    Science.gov (United States)

    Johnson, J. R.; Staid, M.I.; Kraft, M.D.

    2007-01-01

    New measurements of thermal infrared emission spectra (250-1400 cm-1; ???7-40 ??m) of experimentally shocked basalt and basaltic andesite (17-56 GPa) exhibit changes in spectral features with increasing pressure consistent with changes in the structure of plagioclase feldspars. Major spectral absorptions in unshocked rocks between 350-700 cm-1 (due to Si-O-Si octahedral bending vibrations) and between 1000-1250 cm-1 (due to Si-O antisymmetric stretch motions of the silica tetrahedra) transform at pressures >20-25 GPa to two broad spectral features centered near 950-1050 and 400-450 cm-1. Linear deconvolution models using spectral libraries composed of common mineral and glass spectra replicate the spectra of shocked basalt relatively well up to shock pressures of 20-25 GPa, above which model errors increase substantially, coincident with the onset of diaplectic glass formation in plagioclase. Inclusion of shocked feldspar spectra in the libraries improves fits for more highly shocked basalt. However, deconvolution models of the basaltic andesite select shocked feldspar end-members even for unshocked samples, likely caused by the higher primary glass content in the basaltic andesite sample.

  16. Experimental Models of Autoimmune Demyelinating Diseases in Nonhuman Primates.

    Science.gov (United States)

    Stimmer, Lev; Fovet, Claire-Maëlle; Serguera, Ché

    2017-01-01

    Human idiopathic inflammatory demyelinating diseases (IIDD) are a heterogeneous group of autoimmune inflammatory and demyelinating disorders of the central nervous system (CNS). These include multiple sclerosis (MS), the most common chronic IIDD, but also rarer disorders such as acute disseminated encephalomyelitis (ADEM) and neuromyelitis optica (NMO). Great efforts have been made to understand the pathophysiology of MS, leading to the development of a few effective treatments. Nonetheless, IIDD still require a better understanding of the causes and underlying mechanisms to implement more effective therapies and diagnostic methods. Experimental autoimmune encephalomyelitis (EAE) is a commonly used animal model to study the pathophysiology of IIDD. EAE is principally induced through immunization with myelin antigens combined with immune-activating adjuvants. Nonhuman primates (NHP), the phylogenetically closest relatives of humans, challenged by similar microorganisms as other primates may recapitulate comparable immune responses to that of humans. In this review, the authors describe EAE models in 3 NHP species: rhesus macaques ( Macaca mulatta), cynomolgus macaques ( Macaca fascicularis), and common marmosets ( Callithrix jacchus), evaluating their respective contribution to the understanding of human IIDD. EAE in NHP is a heterogeneous disease, including acute monophasic and chronic polyphasic forms. This diversity makes it a versatile model to use in translational research. This clinical variability also creates an opportunity to explore multiple facets of immune-mediated mechanisms of neuro-inflammation and demyelination as well as intrinsic protective mechanisms. Here, the authors review current insights into the pathogenesis and immunopathological mechanisms implicated in the development of EAE in NHP.

  17. Experimental rat models of chronic allograft nephropathy: a review

    Directory of Open Access Journals (Sweden)

    Shrestha B

    2014-07-01

    Full Text Available Badri Shrestha, John HaylorSheffield Kidney Institute, Sheffield Teaching Hospitals NHS Trust, Sheffield, UKAbstract: Chronic allograft nephropathy (CAN is the leading cause of late allograft loss after renal transplantation (RT, which continues to remain an unresolved problem. A rat model of CAN was first described in 1969 by White et al. Although the rat model of RT can be technically challenging, it is attractive because the pathogenesis of CAN is similar to that following human RT and the pathological features of CAN develop within months as compared with years in human RT. The rat model of RT is considered as a useful investigational tool in the field of experimental transplantation research. We have reviewed the literature on studies of rat RT reporting the donor and recipient strain combinations that have investigated resultant survival and histological outcomes. Several different combinations of inbred and outbred rat combinations have been reported to investigate the multiple aspects of transplantation, including acute rejection, cellular and humoral rejection mechanisms and their treatments, CAN, and potential targets for its prevention.Keywords: interventions, therapy, late allograft loss, renal transplantation

  18. Standardised Models for Inducing Experimental Peritoneal Adhesions in Female Rats

    Directory of Open Access Journals (Sweden)

    Bernhard Kraemer

    2014-01-01

    Full Text Available Animal models for adhesion induction are heterogeneous and often poorly described. We compare and discuss different models to induce peritoneal adhesions in a randomized, experimental in vivo animal study with 72 female Wistar rats. Six different standardized techniques for peritoneal trauma were used: brushing of peritoneal sidewall and uterine horns (group 1, brushing of parietal peritoneum only (group 2, sharp excision of parietal peritoneum closed with interrupted sutures (group 3, ischemic buttons by grasping the parietal peritoneum and ligating the base with Vicryl suture (group 4, bipolar electrocoagulation of the peritoneum (group 5, and traumatisation by electrocoagulation followed by closure of the resulting peritoneal defect using Vicryl sutures (group 6. Upon second look, there were significant differences in the adhesion incidence between the groups (P<0.01. Analysis of the fraction of adhesions showed that groups 2 (0% and 5 (4% were significantly less than the other groups (P<0.01. Furthermore, group 6 (69% was significantly higher than group 1 (48% (P<0.05 and group 4 (47% (P<0.05. There was no difference between group 3 (60% and group 6 (P=0.2. From a clinical viewpoint, comparison of different electrocoagulation modes and pharmaceutical adhesion barriers is possible with standardised models.

  19. Optimization of Experimental Model Parameter Identification for Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Rosario Morello

    2013-09-01

    Full Text Available The smart grid approach is envisioned to take advantage of all available modern technologies in transforming the current power system to provide benefits to all stakeholders in the fields of efficient energy utilisation and of wide integration of renewable sources. Energy storage systems could help to solve some issues that stem from renewable energy usage in terms of stabilizing the intermittent energy production, power quality and power peak mitigation. With the integration of energy storage systems into the smart grids, their accurate modeling becomes a necessity, in order to gain robust real-time control on the network, in terms of stability and energy supply forecasting. In this framework, this paper proposes a procedure to identify the values of the battery model parameters in order to best fit experimental data and integrate it, along with models of energy sources and electrical loads, in a complete framework which represents a real time smart grid management system. The proposed method is based on a hybrid optimisation technique, which makes combined use of a stochastic and a deterministic algorithm, with low computational burden and can therefore be repeated over time in order to account for parameter variations due to the battery’s age and usage.

  20. Models of Investor Forecasting Behavior — Experimental Evidence

    Directory of Open Access Journals (Sweden)

    Federico Bonetto

    2017-12-01

    Full Text Available Different forecasting behaviors affect investors’ trading decisions and lead to qualitatively different asset price trajectories. It has been shown in the literature that the weights that investors place on observed asset price changes when forecasting future price changes, and the nature of their confidence when price changes are forecast, determine whether price bubbles, price crashes, and unpredictable price cycles occur. In this paper, we report the results of behavioral experiments involving multiple investors who participated in a market for a virtual asset. Our goal is to study investors’ forecast formation. We conducted three experimental sessions with different participants in each session. We fit different models of forecast formation to the observed data. There is strong evidence that the investors forecast future prices by extrapolating past price changes, even when they know the fundamental value of the asset exactly and the extrapolated forecasts differ significantly from the fundamental value. The rational expectations hypothesis seems inconsistent with the observed forecasts. The forecasting models of all participants that best fit the observed forecasting data were of the type that cause price bubbles and cycles in dynamical systems models, and price bubbles and cycles ended up occurring in all three sessions.

  1. Experimental and numerical investigation of a simplified exhaust model

    Directory of Open Access Journals (Sweden)

    Balázs Vehovszky

    2016-10-01

    Full Text Available A simplified experimental equipment was built to investigate heat radiation and free convection around hot exhaust pipe. Temperatures were measured on the surface of the pipe as like as on heat insulating and -reflecting aluminum shield. Special care was taken to the temperature measuring method: result proved that inappropriate fixing of measuring thermocouples lead to an error of up to 30 % in the temperature-increase values. A detailed 1D numerical model was set up and parametrized so as to the calculation results can be fitted to measured temperature values. In this way thermal properties of the surfaces – as emissivities, absorption coefficients and convective heat transfer coefficients – were determined for temperature sweeps and stationary state cases. The used methods are to be further improved for real automotive parts and higher temperatures.

  2. Modeling the constitutive response of tantalum across experimental platforms

    Science.gov (United States)

    Barton, Nathan; Austin, Ryan; Brown, Justin; Marinak, Marty; Park, Hye-Sook; Prisbrey, Shon

    2017-06-01

    Given the complexities of the mechanics related to strength and the wide range of conditions of interest, it is useful to make comparisons across experimental platforms and across computational methods where possible. Modeling results will be presented from one such cross-platform study; including results from plate impact, ramp compression, and Rayleigh-Taylor instability growth experiments. Observables from strength experiments at more extreme conditions are influenced by a variety of material response characteristics, not just by the material's resistance to plastic deformation. Results include sensitivities to some of these other aspects, such as equation of state and shear modulus formulations. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 (LLNL-ABS-724459).

  3. Experimental human pneumococcal carriage models for vaccine research.

    Science.gov (United States)

    Ferreira, Daniela M; Jambo, Kondwani C; Gordon, Stephen B

    2011-09-01

    Pneumococcal conjugate vaccines have had unprecedented success in controlling vaccine-type invasive pneumococcal disease. As serotype replacement and the complexity of designing vaccines to multiple capsular polysaccharides ultimately pose a threat to these vaccines, the development of alternative protein vaccines is important. Protein vaccines offer the promise of extended serotype coverage, reduced cost, and improved protection against otitis media and pneumococcal pneumonia. As placebo-controlled trials are not currently ethically justifiable, human pneumococcal challenge models using prevention of carriage as a test endpoint offer an attractive link between preclinical studies and clinical efficacy trials. Experimental human pneumococcal carriage studies offer a means of describing mechanisms of protection against carriage and a clinical tool to choose between vaccine candidates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Practical application of stereological kidney methods in experimental animal models

    Directory of Open Access Journals (Sweden)

    María Teresa Fernández García

    2017-01-01

    Full Text Available The kidneys are vital organs responsible for excretion, fluid and electrolyte balance and hormone production. The nephrons are the kidney's functional and structural units. The number, size and distribution of the nephron components contain relevant information on renal function. Stereology is a branch of morphometry that applies mathematical principles to obtain three-dimensional information from serial, parallel and equidistant two-dimensional microscopic sections. Because of the complexity of stereological studies and the lack of scientific literature on the subject, the aim of this paper is to clearly explain, through animal models, the basic concepts of stereology and how to calculate the main kidney stereological parameters that can be applied in future experimental studies.

  5. Dietary whey supplementation in experimental models of wound healing.

    Science.gov (United States)

    Velioglu Ogünç, A; Manukyan, M; Cingi, A; Eksioglu-Demiralp, E; Ozdemir Aktan, A; Süha Yalçin, A

    2008-03-01

    Whey is a dairy product containing milk serum proteins with diverse biological effects. In this study, the effect of dietary whey supplementation on wound healing was investigated. Rats were fed a standard or whey-supplemented diet for three weeks. Wound healing parameters, glutathione, and lipid peroxide levels were determined three days after the application of two different models of wound healing, i.e. laparotomy and colonic anastomosis. Dietary whey supplementation significantly increased glutathione levels and suppressed lipid peroxidation after experimental laparotomy and colonic anastomosis. Bursting pressures, hydroxyproline, and cytokine levels were not changed. Our results show that dietary whey supplementation increases glutathione synthesis and cellular antioxidant defense. Long-term effects of whey feeding on wound healing remains to be investigated.

  6. Calcium Intervention Ameliorates Experimental Model of Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Dariush Haghmorad

    2014-05-01

    Full Text Available Objective: Multiple sclerosis (MS is the most common inflammatory disease of the CNS. Experimental autoimmune encephalomyelitis (EAE is a widely used model for MS. In the present research, our aim was to test the therapeutic efficacy of Calcium (Ca in an experimental model of MS. Methods: In this study the experiment was done on C57BL/6 mice. EAE was induced using 200 μg of the MOG35-55 peptide emulsified in CFA and injected subcutaneously on day 0 over two flank areas. In addition, 250 ng of pertussis toxin was injected on days 0 and 2. In the treatment group, 30 mg/kg Ca was administered intraperitoneally four times at regular 48 hour intervals. The mice were sacrificed 21 days after EAE induction and blood samples were taken from their hearts. The brains of mice were removed for histological analysis and their isolated splenocytes were cultured. Results: Our results showed that treatment with Ca caused a significant reduction in the severity of the EAE. Histological analysis indicated that there was no plaque in brain sections of Ca treated group of mice whereas 4 ± 1 plaques were detected in brain sections of controls. The density of mononuclear infiltration in the CNS of Ca treated mice was lower than in controls. The serum level of Nitric Oxide in the treatment group was lower than in the control group but was not significant. Moreover, the levels of IFN-γ in cell culture supernatant of splenocytes in treated mice were significantly lower than in the control group. Conclusion: The data indicates that Ca intervention can effectively attenuate EAE progression.

  7. Experimental and modelling evidence of shortening heat in cardiac muscle.

    Science.gov (United States)

    Tran, Kenneth; Han, June-Chiew; Crampin, Edmund John; Taberner, Andrew James; Loiselle, Denis Scott

    2017-10-01

    Heat associated with muscle shortening has been repeatedly demonstrated in skeletal muscle, but its existence in cardiac muscle remains contentious after five decades of study. By iterating between experiments and computational modelling, we show compelling evidence for the existence of shortening heat in cardiac muscle and reveal, mechanistically, the source of this excess heat. Our results clarify a long-standing uncertainty in the field of cardiac muscle energetics. We provide a revised partitioning of cardiac muscle energy expenditure to include this newly revealed thermal component. When a muscle shortens against an afterload, the heat that it liberates is greater than that produced by the same muscle contracting isometrically at the same level of force. This excess heat is defined as 'shortening heat', and has been repeatedly demonstrated in skeletal muscle but not in cardiac muscle. Given the micro-structural similarities between these two muscle types, and since we imagine that shortening heat is the thermal accompaniment of cross-bridge cycling, we have re-examined this issue. Using our flow-through microcalorimeter, we measured force and heat generated by isolated rat trabeculae undergoing isometric contractions at different muscle lengths and work-loop (shortening) contractions at different afterloads. We simulated these experimental protocols using a thermodynamically constrained model of cross-bridge cycling and probed the mechanisms underpinning shortening heat. Predictions generated by the model were subsequently validated by a further set of experiments. Both our experimental and modelling results show convincing evidence for the existence of shortening heat in cardiac muscle. Its magnitude is inversely related to the afterload or, equivalently, directly related to the extent of shortening. Computational simulations reveal that the heat of shortening arises from the cycling of cross-bridges, and that the rate of ATP hydrolysis is more sensitive to

  8. Experimental model of severe acute pancreatitis in rabbits Modelo experimental de pancreatite aguda grave em coelhos

    Directory of Open Access Journals (Sweden)

    Alberto Goldenberg

    2007-10-01

    Full Text Available PURPOSE: To develop an experimental model of severe acute pancreatitis in rabbits through a pancreatic ductal injection of sodium taurocholate. METHODS: Twenty-four albino rabbits of the New Zealand lineage were distributed into four groups of six animals (A, B, C and S. The rabbits of three experimental groups (A, B and C were submitted to a laparatomy and received a pancreatic ductal injection of 1ml/kg sodium taurocholate 5%. Also, they were submitted to further laparatomies after 4h, 8h and 12h, respectively. The control group (S was subdivided into two groups of three animals: in subgroup S1 only the pancreatic duct catheterization was performed whereas in subgroup S2 the pancreatic duct catheterization as well as an injection of 1ml/kg physiologic solution 0.9% were carried out. After 12 hours, the rabbits were evaluated. In the re-intervention, blood was collected to determine the amylasemia and a pancreatectomy was carried out to investigate interstitial infiltration, steatonecrosis and necrosis of the organ, using an optical microscope. RESULTS: There was an elevation of amylase in all groups thus proving the existence of acute pancreatitis. The size of the interlobular septum increased progressively with a greater variation between group S1 (0.13 and group C (0. 53 (p=0.035. While all the animals in group A exhibited focal cellular necrosis, it was more intense in the rabbits of group B and culminated with a high proportion of severe pancreatic necrosis in group C animals. The difference in the intensity of cellular necrosis showed statistic significance (p=0.001. CONCLUSION: The proposed experimental model demonstrated its reproducibility and effectiveness in producing severe acute pancreatitis in rabbits.OBJETIVO: Desenvolver modelo experimental de pancreatite aguda grave em coelhos por meio da injeção de taurocolato de sódio no ducto pancreático. MÉTODOS: Vinte e quatro coelhos albinos da linhagem Nova Zelândia foram distribu

  9. Experimental model for Porphyromonas gingivalis infection in animals.

    Science.gov (United States)

    Eke, P I; Rotimi, V O; Laughon, B E

    1996-03-01

    A virulence model suitable for studying the dynamics of Porphyromonas gingivalis infection, including the pathogenicity of P. gingivalis in experimentally induced infections of multiple organs was developed using mouse and hamster. Virulence of P. gingivalis strains was expressed contrastingly in subcutaneous (sc) infection in the Murine abscess model (MAM) and the Hamsters abscess model (HAM). Subcutaneous infection in the MAM was characterized by a gravity abscess, spreading from the primary site of inoculation downwards, frequently erupting as a secondary lesion. In contract, s.c. P. gingivalis infection in HAM was characterized as a palpable localized abscess at the primary site of inoculation. When the Semi-Solid Agar (SSA) was added to the mono-culture of P. gingivalis, reproducibility of infection in both models was enhanced. P. gingivalis culture supplemented with haemin, or combined with oral Actinomyces viscosus had its virulence overtly enhanced and often fatal in the MAM. Menadione, Eh reducing agents and mixture with the Streptococcus or A. neaslundii did not potentiate virulence in either mode. Transtracheal challenge of the lungs of hamster with P. gingivalis initiated an early pneumonitis and later sequelae of necrosis and abscess formation. Also, abscess was induced by direct inoculation of P. gingivalis in the muscles, liver and testes, but did not induce intra-abdominal abscesses. In conclusion, the HAM applied with the SSA procedure caused a localized P. gingivalis tissue infection with practical advantages for quantitative and qualitative studies of P. gingivalis infections. This study also demonstrates the pathogenic potential of P. gingivalis by reproducing similar infections in multiple anatomical sites.

  10. Microbial dormancy improves development and experimental validation of ecosystem model.

    Science.gov (United States)

    Wang, Gangsheng; Jagadamma, Sindhu; Mayes, Melanie A; Schadt, Christopher W; Steinweg, J Megan; Gu, Lianhong; Post, Wilfred M

    2015-01-01

    Climate feedbacks from soils can result from environmental change followed by response of plant and microbial communities, and/or associated changes in nutrient cycling. Explicit consideration of microbial life-history traits and functions may be necessary to predict climate feedbacks owing to changes in the physiology and community composition of microbes and their associated effect on carbon cycling. Here we developed the microbial enzyme-mediated decomposition (MEND) model by incorporating microbial dormancy and the ability to track multiple isotopes of carbon. We tested two versions of MEND, that is, MEND with dormancy (MEND) and MEND without dormancy (MEND_wod), against long-term (270 days) carbon decomposition data from laboratory incubations of four soils with isotopically labeled substrates. MEND_wod adequately fitted multiple observations (total C-CO2 and (14)C-CO2 respiration, and dissolved organic carbon), but at the cost of significantly underestimating the total microbial biomass. MEND improved estimates of microbial biomass by 20-71% over MEND_wod. We also quantified uncertainties in parameters and model simulations using the Critical Objective Function Index method, which is based on a global stochastic optimization algorithm, as well as model complexity and observational data availability. Together our model extrapolations of the incubation study show that long-term soil incubations with experimental data for multiple carbon pools are conducive to estimate both decomposition and microbial parameters. These efforts should provide essential support to future field- and global-scale simulations, and enable more confident predictions of feedbacks between environmental change and carbon cycling.

  11. An experimental model of vitreous motion induced by eye rotations.

    Science.gov (United States)

    Bonfiglio, Andrea; Lagazzo, Alberto; Repetto, Rodolfo; Stocchino, Alessandro

    2015-01-01

    During eye rotations the vitreous humour moves with respect to the eye globe. This relative motion has been suggested to possibly have an important role in inducing degradation of the gel structure, which might lead to vitreous liquefaction and/or posterior vitreous detachment. Aim of the present work is to study the characteristics of vitreous motion induced by eye rotations. We use an experimental setup, consisting of a Perspex model of the vitreous chamber that, for simplicity, is taken to have a spherical shape. The model is filled with an artificial vitreous humour, prepared as a solution of agar powder and hyaluronic acid sodium salt in deionised water, which has viscoelastic mechanical properties similar to those of the real vitreous. The model rotates about an axis passing through the centre of the sphere and velocity measurements are taken on the equatorial plane orthogonal to the axis of rotation, using an optical technique. The results show that fluid viscoelasticity has a strong influence on flow characteristics. In particular, at certain frequencies of oscillation of the eye model, fluid motion can be resonantly excited. This means that fluid velocity within the domain can be significantly larger than that of the wall. The frequencies for which resonant excitation occurs are within the range of possible eye rotations frequencies. Therefore, the present results suggest that resonant excitation of vitreous motion is likely to occur in practice. This, in turn, implies that eye rotations produce large stresses on the retina and within the vitreous that may contribute to the disruption of the vitreous gel structure. The present results also have implications for the choice of the ideal properties for vitreous substitute fluids.

  12. Estudo experimental da influência da zona de recirculação na combustão de gás natural.

    OpenAIRE

    Gustavo Adolfo Ronceros Rivas

    2005-01-01

    O presente trabalho apresenta uma investigação experimental sobre a influência da presença de uma zona de recirculação interna (ZRI) no processo de combustão de gás natural. Basicamente os experimentos foram conduzidos para verificar a influência da ZRI no limite de "blow out", balanço de energia e emissões de CO e NO. Um queimador com configuração especial foi projetado para permitir mudanças na intensidade da ZRI e os experimentos foram conduzidos em uma câmara de combustão horizontal refri...

  13. Oxigenação extracorpórea por membrana e alterações hematológicas em estudo experimental Extra-corporeal membrane oxygenation and hematological alterations in an experimental study

    Directory of Open Access Journals (Sweden)

    Aírton C. Moscardini

    2002-04-01

    Full Text Available A oxigenação extracorpórea por membrana é uma técnica de suporte cardiopulmonar prolongado, com finalidade de auxiliar o pulmão e/ou o coração, quando os mesmos entram em falência não responsiva aos tratamentos convencionais não invasivos. O objetivo do presente estudo foi avaliar as alterações hematimétricas durante 12 horas de ECMO em estudo animal. Foram estudados 11 ovinos, da raça Santa Inês, sendo seis machos e cinco fêmeas, com peso entre 5,4 e 15kg (12,2 ± 3,1kg. Nos cinco primeiros animais, o prime do circuito extracorpóreo foi feito com solução de Ringer com lactato de sódio (Ringer-Lactato Glicolabor - Ribeirão Preto - SP e solução de gelatina a 3,5% (Hisocel - Campinas - SP, na proporção de 2:1, no total de 750ml. No sexto animal foi diminuído o volume do prime para 450ml, sendo 250ml de solução de Ringer com lactato de sódio e 200ml de solução de gelatina a 3,5%. Nos cinco últimos experimentos (casos 7 a 11, empregou-se 250ml de sangue fresco total anticoagulado com citrato de sódio e 200ml de Ringer com lactato de sódio. Os exames realizados foram: hematócrito, hemoglobina, leucócitos, plaquetas, albumina e globulina. No estudo estatístico foram empregados os testes de Mann-Whitney e Análise da Variância e, no caso deste último demonstrar variação significativa (pExtra-corporeal membrane oxygenation is a technique of prolonged cardiopulmonary support, with the objective of assisting the lungs and/or heart when they start to fail and do not respond to conventional non-invasive treatment. The aim of this study was to evaluate hematological alterations during 12 hours of extra-corporeal membrane oxygenation in animals. Eleven sheep, six males and five females, of the Santa Inês breed with weights ranging from 5.4 to 15kg (12.2±3.1kg were studied. With the first five animals, Ringer solution with sodium lactate (Ringer - Lactato Glicolabor - Ribeirão Preto - SP and a 3.5% gelatine solution

  14. Experimental Investigation and Modeling of Copper Smelting Slags

    Science.gov (United States)

    Starodub, Konstantin; Kuminova, Yaroslava; Dinsdale, Alan; Cheverikin, Vladimir; Filichkina, Vera; Saynazarov, Abdukahhar; Khvan, Alexandra; Kondratiev, Alex

    2016-10-01

    Effective extraction of copper from sulfide ores requires careful operation of a copper smelter, which in turn depends very much on chemistry of the feed and resulted slag and matte. For example, chemical composition of copper smelting slags has to be in a certain range to ensure that their properties are within specific limits. Disobeying these rules may lead to complications in smelting operation, poor quality of the copper products, and premature shutdown of the copper smelter. In the present paper the microstructure and phase composition of slags from the Almalyk copper flash smelter were investigated experimentally and then modeled thermodynamically to evaluate potential ways of improvement and optimization of the copper smelting process and its products. The slag samples were taken at different stages of the copper smelting process: on slag tapping, after slag transportation to a deposition site, and at the site. Experimental investigation included the XRD, XRF, and SEM techniques, which were also confirmed by the traditional wet chemistry analysis. Thermodynamic modeling was carried out using thermochemical software package MTDATA, which enables thermodynamic and physical properties of the matte, slag, and gas phases to be calculated in a wide range of temperatures, pressures, and chemical compositions. In addition, slag viscosities and corresponding matte settling rates were estimated using the modified Urbain and Utigard-Warczok models, and the Hadamard-Rybczynski equation, respectively. It was found that the copper content in the slags may vary significantly depending on the location of slag sampling. Cu was found to be present as sulfide particles, almost no Cu was found to be dissolved in the slag. Analysis of microstructure and phase composition showed that major phase found in the samples is fayalite, while other phases are complex spinels (based on magnetite), different sulfides, and a glass-like phase. Thermodynamic calculations demonstrated the

  15. Experimental osteonecrosis: development of a model in rodents administered alendronate.

    Science.gov (United States)

    Conte, Nicolau; Spolidorio, Luis Carlos; Andrade, Cleverton Roberto de; Esteves, Jônatas Caldeira; Marcantonio, Elcio

    2016-08-22

    The main objective of this study was to cause bisphosphonate-related osteonecrosis of the jaws to develop in a rodent model. Adult male Holtzman rats were assigned to one of two experimental groups to receive alendronate (AL; 1 mg/kg/week; n = 6) or saline solution (CTL; n = 6). After 60 days of drug therapy, all animals were subjected to first lower molar extraction, and 28 days later, animals were euthanized. All rats treated with alendronate developed osteonecrosis, presenting as ulcers and necrotic bone, associated with a significant infection process, especially at the inter-alveolar septum area and crestal regions. The degree of vascularization, the levels of C-telopeptide cross-linked collagen type I and bone-specific alkaline phosphatase, as well as the bone volume were significantly reduced in these animals. Furthermore, on radiographic analysis, animals treated with alendronate presented evident sclerosis of the lamina dura of the lower first molar alveolar socket associated with decreased radiographic density in this area. These findings indicate that the protocol developed in the present study opens new perspectives and could be a good starting model for future property design.

  16. Experimental osteonecrosis: development of a model in rodents administered alendronate

    Directory of Open Access Journals (Sweden)

    Nicolau CONTE NETO

    Full Text Available Abstract The main objective of this study was to cause bisphosphonate-related osteonecrosis of the jaws to develop in a rodent model. Adult male Holtzman rats were assigned to one of two experimental groups to receive alendronate (AL; 1 mg/kg/week; n = 6 or saline solution (CTL; n = 6. After 60 days of drug therapy, all animals were subjected to first lower molar extraction, and 28 days later, animals were euthanized. All rats treated with alendronate developed osteonecrosis, presenting as ulcers and necrotic bone, associated with a significant infection process, especially at the inter-alveolar septum area and crestal regions. The degree of vascularization, the levels of C-telopeptide cross-linked collagen type I and bone-specific alkaline phosphatase, as well as the bone volume were significantly reduced in these animals. Furthermore, on radiographic analysis, animals treated with alendronate presented evident sclerosis of the lamina dura of the lower first molar alveolar socket associated with decreased radiographic density in this area. These findings indicate that the protocol developed in the present study opens new perspectives and could be a good starting model for future property design.

  17. [Coronary microvascular disease: from experimental models to clinical practice].

    Science.gov (United States)

    Vecoli, Cecilia; Caselli, Chiara; Caruso, Raffaele; Morales, Maria Aurora

    2012-01-01

    Coronary vascular microcirculation plays a major role in the pathogenesis of left ventricular dysfunction as well as in the development of heart failure. Coronary microcirculation includes all the vessels which contribute to provide resistance to coronary flow. It represents the district where coronary circulation blood flow is regulated to ensure that each structural and functional cardiac component receives the proper amount of oxygen and metabolic substrates through the capillary network. Coronary microcirculation is fundamental for myocardial function which largely depends on the ratio between energetic metabolites received from coronary circulation and their utilization by the myocytes. Alterations in coronary microvascular circulation which limit myocardial perfusion can cause repetitive ischemic events leading to left ventricular dysfunction in several ischemic and non ischemic cardiomyopathies as the idiopathic dilated cardiomyopathy. To date, mechanisms underlying microvascular dysfunction are not completely understood and experimental animal models are employed to study alterations which may cause microcirculation impairment. These animals models are unique tools to identify new therapeutic targets, to test new drug therapies for the treatment of left ventricular dysfunction as well as its progression towards overt heart failure.

  18. Experimental studies on power transformer model winding provided with MOVs

    Directory of Open Access Journals (Sweden)

    G.H. Kusumadevi

    2017-05-01

    Full Text Available Surge voltage distribution across a HV transformer winding due to appearance of very fast rise time (rise time of order 1 μs transient voltages is highly non-uniform along the length of the winding for initial time instant of occurrence of surge. In order to achieve nearly uniform initial time instant voltage distribution along the length of the HV winding, investigations have been carried out on transformer model winding. By connecting similar type of metal oxide varistors across sections of HV transformer model winding, it is possible to improve initial time instant surge voltage distribution across length of the HV transformer winding. Transformer windings with α values 5.3, 9.5 and 19 have been analyzed. The experimental studies have been carried out using high speed oscilloscope of good accuracy. The initial time instant voltage distribution across sections of winding with MOV remains nearly uniform along length of the winding. Also results of fault diagnostics carried out with and without connection of MOVs across sections of winding are reported.

  19. Development of Experimental Tissue Models for Blast Injury

    Science.gov (United States)

    Butler, Benjamin; Bo, Chiara; Williams, Alun; Jardine, Andy; Brown, Katherine

    2013-06-01

    There is a pressing need to better understand the relationship between the intensity of a blast wave and the clinical consequences for victims of an explosion. In order to quantitatively study how these factors correlate with one another, blast injury tissue models are being developed. Sections of larynx, trachea and pulmonary tissue were excised from a recently sacrificed pig and maintained on ice prior to testing. The samples were subjected to strain rates of between 0.001 s-1 and 1000 s-1 in the laboratory by using a Split Hopkinson Pressure Bar and quasi-static testing apparatus. During high strain rate testing, samples were housed in a polycarbonate chamber which permitted experimentation on tissue held in fluid. Data were analysed using 1, 2 and 3 wave analysis software in Matlab to yield information about the material properties of both undamaged and damaged tissues. In addition, macroscopic changes in tissue organization were also visualized using histopathological techniques. This work is being extended to cellular and animal models to derive more detailed information about the underlying molecular changes relating to blast-induced damage and repair. The Royal British Legion Centre for Blast Injury Studies.

  20. Effectiveness and safety of iodopovidone in an experimental pleurodesis model

    Directory of Open Access Journals (Sweden)

    Lisete R. Teixeira

    2013-04-01

    Full Text Available OBJECTIVES: Chemical pleurodesis is an important therapeutic tool to control recurrent malignant pleural effusion. Among the various sclerosing agents, iodopovidone is considered effective and safe. However, in a recent study, ocular changes were described after iodopovidone was used in recurrent pneumothorax. The aim of the study was to evaluate the efficacy and morbidity of iodopovidone pleurodesis in an experimental model. METHODS: New Zealand rabbits were submitted to intrapleural injection of iodopovidone at concentrations of 2%, 4% and 10%. Biochemical (lactic dehydrogenase, proteins, triiodothyronine, free thyroxine, urea and creatinine and immunological (Interleukin-8 [IL-8], VEGF and TGFβ parameters were measured in the pleural fluid and blood. After 1, 3, 7, 14 and 28 days, groups of animals were euthanized, and macro- (pleura and microscopic (pleura and retina analyses were performed. RESULTS: An early pleural inflammatory response with low systemic repercussion was observed without corresponding changes in thyroid or renal function. The higher concentrations (4% and 10% correlated with greater initial exudation, and maximum pleural thickening was observed after 28 days. No changes were observed in the retinal pigment epithelium of the rabbits. CONCLUSION: Iodopovidone is considered to be an effective and safe sclerosing agent in this animal model. However, its efficacy, tolerance and safety in humans should be further evaluated.

  1. An experimental model of hemolysis-induced acute pancreatitis

    Directory of Open Access Journals (Sweden)

    Saruc M.

    2003-01-01

    Full Text Available The literature indicates that acute pancreatitis is a complication of massive hemolysis with a prevalence of about 20%. We describe an experimental model of hemolysis-induced acute pancreatitis. Hemolytic anemia was induced in rats by a single ip injection of 60 mg/kg of 20 mg/ml acetylphenylhydrazine (APH in 20% (v/v ethanol on the first experimental day (day 0. One hundred and fifty Wistar albino rats weighing 180-200 g were divided into three groups of 50 animals each: groups 1, 2 and 3 were injected ip with APH, 20% ethanol, and physiological saline, respectively. Ten rats from each group were sacrificed on study days 1, 2, 3, 4 and 5. Serum amylase, lipase levels and pancreatic tissue tumor necrosis factor-alpha (TNF-alpha and platelet-activating factor (PAF contents were determined and a histological examination of the pancreas was performed. No hemolysis or pancreatitis was observed in any of the rats in groups 2 and 3. In group 1, massive hemolysis was observed in 35 (70% of 50 rats, moderate hemolysis in seven (14%, and no hemolysis in eight (16%. Thirty-three of 35 (94.2% rats with massive hemolysis had hyperamylasemia, and 29 of these rats (82.8% had histologically proven pancreatitis. The most severe pancreatitis occurred on day 3, as demonstrated by histology. Tissue TNF-alpha and PAF levels were statistically higher in group 1 than in groups 2 and 3. Acute massive hemolysis induced acute pancreatitis, as indicated by histology, in almost 80% of cases. Hemolysis may induce acute pancreatitis by triggering the release of proinflammatory and immunoregulatory cytokines.

  2. Epidural blood patch: A study on an experimental model

    Directory of Open Access Journals (Sweden)

    S K Sengupta

    2013-01-01

    Full Text Available Aim: Epidural blood patch has been used to treat spinal headache with varying success. An experimental model was designed to ascertain whether an epidural blood patch can be used to seal the needle puncture sites in dural repair. Materials and Methods: Bovine dura was secured to the lower end of an open-ended calibrated plastic cylinder. Multiple interrupted stitches were applied over a 02 cm length of the dura without any incision. The cylinder was filled with colored saline gradually with the dura placed in a dependent position. Height of the water column at which sutured dura leaked was recorded. A layer of fresh blood was laid over the dura and allowed to clot. The test was repeated and the hydrostatic pressure at which leak took place was noted again. The test was repeated three times. Similar studies were done with two specimens with 02-cm dural incisions repaired with interrupted stitches of 4-0 silk in one specimen and 4-0 prolene in another, and three specimens with 3-mm unsutured dural rent in one and dural punctures made with 23-G and 26-G spinal needles in the other two. Results: All the dural preparations leaked, at a very low hydrostatic pressure (<30 mm of H 2 O. By covering the needle puncture sites with clotted blood, a watertight closure could be achieved, that can withstand a much higher hydrostatic pressure (mean of 180 mm of H 2 O. Conclusion : The experimental findings indicate that an epidural blood patch does enhance the ability of a dural closure to prevent a leak; however, its utility in clinical setting is questionable.

  3. An optimized animal model for partial and total skin thickness burns studies Um modelo animal aperfeiçoado para estudo de queimaduras superficiais e profundas da pele

    Directory of Open Access Journals (Sweden)

    Ana Paula Bomfim Soares Campelo

    2011-01-01

    Full Text Available PURPOSE: Development of an improved animal model for studying skin burns in rats. METHODS: Twenty-four male Wistar rats were randomly assigned to four groups (n=6: G1-Control, G2- T100°C, G3-T150°C and G4-T200°C. Two 10 x 10 mm squares were outlined with a sterile surgical marker on each side and along the vertebral column using a prepared template positioned between the anterior and posterior limbs. G2-G4 rats were subjected to 100°C, 150°C and 200ºC thermal burns, respectively. G1 rats served as controls. Burns were inflicted by applying a copper plate connected to an electronic temperature controlling device to the dorsal skin of anesthetized rats. Four burns were produced on each animal (total area: 4 cm²/animal leaving about 1 cm of undamaged skin between burn areas. Analgesia was administered during 24 h after burn injury by adding 30 mg codeine phosphate hemihydrate to 500 ml tap water. RESULTS: The application of 100°C and 150ºC resulted in partial thickness skin burns with central reepithelialization of the burned area only at 100°C. In G4 group the whole thickness of the skin was injured without central reepithelialization. However, there was marginal reepithelialization in all groups. CONCLUSION: The model studied is inexpensive and easily reproducible, enabling the achievement of controlled burns with partial or total impairment of the skin in experimental animals.OBJETIVO: Desenvolvimento de um modelo animal aperfeiçoado para estudo de queimaduras cutâneas em ratos. MÉTODOS: Vinte e quatro ratos Wistar, machos, foram distribuídos aleatoriamente em quatro grupos (n=6: G1-Controle, G2-T100°C, G3-T150°C e G4-T200°C. Dois quadrados medindo 10x10 mm foram delineados com um marcador cirúrgico estéril em cada lado e ao longo da coluna vertebral e posicionados entre os membros anteriores e posteriores, utilizando um molde previamente preparado. Os ratos dos grupos G2-G4 foram submetidos a queimaduras térmicas de 100

  4. Early differentiation of the Moon: Experimental and modeling studies and experimental and modeling studies of massif anorthosites

    Science.gov (United States)

    Longhi, John

    1994-01-01

    NASA grant NAG9-329 was in effect from 3/1/89 to 8/31/94, the last 18 months being a no-cost extension. While the grant was in effect, the P.I., coworkers, and students gave 22 talks and poster sessions at professional meetings, published 12 articles in referred journals (one more is in press, and another is in review), and edited 2 workshop reports relevant to this project. Copies of all the publications are appended to this report. The major accomplishments during the grant period have derived from three quarters: 1) the application of quantitative models of fractional crystallization and partial melting to various problems in planetary science, such as the petrogenesis of picritic glasses and mare basalts and the implications of the SNC meteorites for martian evolution; 2) an experimental study of silicate liquid immiscibility relevant to early lunar differentiation and the petrogenesis of evolved highlands rocks; and 3) experimental studies of massif anorthosites and related rocks that provide terrestrial analogs for the proposed origin of lunar anorthosites by multistage processes. The low-pressure aspects of the quantitative models were developed by the P.I. in the 1980s with NASA support and culminated with a paper comparing the crystallization of terrestrial and lunar lavas. The basis for the high-pressure modifications to the quantitative models is a data set gleaned from high pressure melting experiments done at Lamont and is supplemented by published data from other labs that constrain the baric and compositional dependences of various liquidus phase boundaries such as olivine/orthopyroxene, relevant to the melting of the mantles of the terrestrial planets. With these models it is possible to predict not only the thermal and compositional evolution of magmatic liquids ranging in composition from lumar mare basalt to terrestrial calc-alkaline basalts, but also the small increments of fractional melting that are produced when mantle rises adiabatically

  5. Thermal infrared spectroscopy and modeling of experimentally shocked plagioclase feldspars

    Science.gov (United States)

    Johnson, J. R.; Horz, F.; Staid, M.I.

    2003-01-01

    Thermal infrared emission and reflectance spectra (250-1400 cm-1; ???7???40 ??m) of experimentally shocked albite- and anorthite-rich rocks (17-56 GPa) demonstrate that plagioclase feldspars exhibit characteristic degradations in spectral features with increasing pressure. New measurements of albite (Ab98) presented here display major spectral absorptions between 1000-1250 cm-1 (8-10 ??m) (due to Si-O antisymmetric stretch motions of the silica tetrahedra) and weaker absorptions between 350-700 cm-1 (14-29 ??m) (due to Si-O-Si octahedral bending vibrations). Many of these features persist to higher pressures compared to similar features in measurements of shocked anorthite, consistent with previous thermal infrared absorption studies of shocked feldspars. A transparency feature at 855 cm-1 (11.7 ??m) observed in powdered albite spectra also degrades with increasing pressure, similar to the 830 cm-1 (12.0 ??m) transparency feature in spectra of powders of shocked anorthite. Linear deconvolution models demonstrate that combinations of common mineral and glass spectra can replicate the spectra of shocked anorthite relatively well until shock pressures of 20-25 GPa, above which model errors increase substantially, coincident with the onset of diaplectic glass formation. Albite deconvolutions exhibit higher errors overall but do not change significantly with pressure, likely because certain clay minerals selected by the model exhibit absorption features similar to those in highly shocked albite. The implication for deconvolution of thermal infrared spectra of planetary surfaces (or laboratory spectra of samples) is that the use of highly shocked anorthite spectra in end-member libraries could be helpful in identifying highly shocked calcic plagioclase feldspars.

  6. Technological study of experimental proton exchange polymer membrane fuel cells; Estudo tecnologico de celulas a combustivel experimentais a membrana polimerica trocadora de protons

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, Thais Aranha de Barros

    2004-07-01

    Experimental studies to achieve an optimized behavior of a unit PEM-fuel cell with an active area of 25cm{sup 2} were carried out. Polarization curves, surface response methodology and regression methodology were used for the analysis. The different methodologies identified the interactions between the parameters that were studied. These parameters were, humidifying temperature, fuel cell operating temperature and the flows of hydrogen and oxygen. MEAs were produced by the spray and hot pressing hybrid method, developed at IPEN. The studies were done with these MEAs and equivalent commercial ones. The MEAs producing method used induced an important variation on the quantity of platinum in the electrodes. This fact has showed to have a great influence in the results. The optimized values were: oxygen flow from 30 to 35% of consume (70 to 65% of excess), fuel cell operating temperature from 60 to 62 deg C and 0.41 mg of platinum in the electrodes. The hydrogen flows and the humidifying temperature have not showed a major influence in the fuel cell behavior, in the studied variable range. (author)

  7. Avaliação histológica da neurorrafia término-lateral: estudo experimental em ratos Histologic evaluation of end-to-side neurorrhaphy: experimental study in rats

    Directory of Open Access Journals (Sweden)

    Fabiano Inácio de Souza

    2011-01-01

    Full Text Available OBJETIVO: Realizar estudo histológico comparando o crescimento axonal após neurorrafia término-lateral com e sem epineurectomia. MÉTODOS: foram utilizados vinte ratos Wistar, machos, divididos em dois grupos de 10 ratos cada. Um segmento de 1,0cm do nervo tibial e, foi transposto para o lado contralateral, sendo suturado no nervo ciático D. No grupo I, a sutura foi realizada diretamente no epineuro, enquanto que no grupo II foi realizado epineurectomia. Após 4 semanas foi realizado avaliação histológica do segmento transposto e no nervo ciático D, no sitio distal à lesão. RESULTADOS: demonstrou-se baixa quantidade de fibras remielinizadas, variando de 7 a 51 fibras no Grupo I e de 10 a 91 fibras no Grupo II. Utilizou-se o teste U de Mann-Whitney, com p=0,31, demonstrando que não há diferença estatisticamente significante entre os dois grupos. Não há relação positiva entre o número de fibras remielinizadas no enxerto e no sitio distal à lesão do ciático. CONCLUSÃO: A neurorrafia término-lateral, com e sem janela epineural, não promove remielinização eficiente. Nivel de evidência: Nível II: Estudo prospectivo comparativoOBJECTIVE: The aim of this study was to histologically compare the axonal sprouting after end-to-side neurorrhaphy with or without epineurotomy. METHODS: twenty male Wistar rats were used, divided into two groups of 10 rats each. A 1.0cm segment of the tibial nerve E was dried and sutured on the opposite side, where it was sutured into the sciatic nerve D. In Group I, the suture was made directly in the epineurium and in Group II, epineurotomy was performed. After 4 weeks, histological evaluation was carried out of the transposed segment and the sciatic nerve distal to the suture. RESULTS: the results showed a small number of remyelinated fibers, varying from 7 to 51 fibers in Group I and from 10 to 91 fibers in Group II. The Mann-Whitney U test was used, with p=0.311, showing there is no statistically

  8. Repercussões histopatológicas da colostomia no coto colônico distal desfuncionalizado: estudo experimental em ratos

    Directory of Open Access Journals (Sweden)

    Francisco Edilson Leite Pinto Júnior

    Full Text Available O objetivo deste trabalho foi evidenciar as repercussões histopatológicas da colostomia no segmento desfuncionalizado e, dessa forma, criar um modelo experimental da colite de derivação fecal (CO. Foram utilizados 65 ratos, adultos, da raça Wistar, com peso variando de 220 a 300 g. Os animais foram divididos em 13 grupos, contendo cinco ratos. Do grupo 1 ao grupo 12, os animais foram submetidos a laparotomia mediana, sendo realizada uma colostomia terminal tipo boca única, e observados, por períodos variados de tempo, com o máximo de cem dias. Os animais, após serem mortos, foram necropsiados e retirado o segmento co1ônico desfuncionalizado para a avaliação histopatológica. Essa avaliação consistia de uma análise quantitativa, através da medida da espessura da mucosa colônica, e de uma análise qualitativa, mediante avaliação subjetiva: da presença de infiltrado inflamatório agudo ou crônico na lâmina própria; das alterações na arquitetura das criptas colônicas; da presença de hiperplasia folicular linfóide e de linfócitos na luz dos vasos da submucosa; e da presença de eosinófilos na luz intestinal. No grupo 12, após o 100° dia de pós-operatório (OPO, foi realizada a reconstrução do trânsito intestinal, e, após trinta dias, o cólon descendente foi retirado para a análise histopatológica. O método de Tukey e o teste "t" de Student foram utilizados como parte da análise dos resultados. Verificou-se uma redução estatisticamente significante da espessura da mucosa colônica a partir do 4000PO. Concluiu-se que a colostomia desfuncionalizante realizada em ratos reproduziu alterações histopatológicas compatíveis com a colite de derivação, e que estas mostraram-se reversíveis após a reconstrução do trânsito intestinal.

  9. Neovascular growth in an experimental alkali corneal burn model.

    Science.gov (United States)

    Figueroa-Ortiz, L C; Martín Rodríguez, O; García-Ben, A; García-Campos, J

    2014-08-01

    To analyse the length and area of corneal surface occupied by vessels, and their location in an experimental model of alkali burn-induced corneal neovascularization. An injury to the central cornea of the right eye in 91 Sprague-Dawley rats was induced using a silver nitrate pencil. The rats were divided in 7 groups that were sacrificed 2, 4, 6, 8, 10, 12 and 14 days post-injury, and then perfused with a mixture of Chinese ink in PBS -phosphate buffer saline-. Corneas were flat-mounted processed and divided in 4 quadrants. Corneal neovascular growth parameters (length and area) and the location of these vessels were performed blind. The results were statistically analysed. Neovascular growth was observed from day 2, reaching its maximum peak in length and area on the 12th day post-injury. A slight reduction in corneal neovascularization was observed after this day. The vessels were initially located in the middle third of the stroma and tended to be observed in the anterior third during the course of the experiment. Neovascularisation was observed on day 2 post-injury in all sectors of corneal surface. Neovascular growth was uniform during the experiment. Neovessels were located in the middle and anterior third of the cornea. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  10. Modeling experimental plasma diagnostics in the FLASH code: proton radiography

    Science.gov (United States)

    Flocke, Norbert; Weide, Klaus; Feister, Scott; Tzeferacos, Petros; Lamb, Donald

    2017-10-01

    Proton radiography is an important diagnostic tool for laser plasma experiments and for studying magnetized plasmas. We describe a new synthetic proton radiography diagnostic recently implemented into the FLASH code. FLASH is an open source, finite-volume Eulerian, spatially adaptive radiation hydrodynamics and magneto-hydrodynamics code that incorporates capabilities for a broad range of physical processes. Proton radiography is modeled through the use of the (relativistic) Lorentz force equation governing the motion of protons through 3D domains. Both instantaneous (one time step) and time-resolved (over many time steps) proton radiography can be simulated. The code module is also equipped with several different setup options (beam structure and detector screen placements) to reproduce a large variety of experimental proton radiography designs. FLASH's proton radiography diagnostic unit can be used either during runtime or in post-processing of simulation results. FLASH is publicly available at flash.uchicago.edu. U.S. DOE NNSA, U.S. DOE NNSA ASC, U.S. DOE Office of Science and NSF.

  11. Atomistic modeling at experimental strain rates and timescales

    Science.gov (United States)

    Yan, Xin; Cao, Penghui; Tao, Weiwei; Sharma, Pradeep; Park, Harold S.

    2016-12-01

    Modeling physical phenomena with atomistic fidelity and at laboratory timescales is one of the holy grails of computational materials science. Conventional molecular dynamics (MD) simulations enable the elucidation of an astonishing array of phenomena inherent in the mechanical and chemical behavior of materials. However, conventional MD, with our current computational modalities, is incapable of resolving timescales longer than microseconds (at best). In this short review article, we briefly review a recently proposed approach—the so-called autonomous basin climbing (ABC) method—that in certain instances can provide valuable information on slow timescale processes. We provide a general summary of the principles underlying the ABC approach, with emphasis on recent methodological developments enabling the study of mechanically-driven processes at slow (experimental) strain rates and timescales. Specifically, we show that by combining a strong physical understanding of the underlying phenomena, kinetic Monte Carlo, transition state theory and minimum energy pathway methods, the ABC method has been found to be useful in a variety of mechanically-driven problems ranging from the prediction of creep-behavior in metals, constitutive laws for grain boundary sliding, void nucleation rates, diffusion in amorphous materials to protein unfolding. Aside from reviewing the basic ideas underlying this approach, we emphasize some of the key challenges encountered in our own personal research work and suggest future research avenues for exploration.

  12. An Experimental Model for Resistance Exercise in Rodents

    Directory of Open Access Journals (Sweden)

    Humberto Nicastro

    2012-01-01

    Full Text Available This study aimed to develop an equipment and system of resistance exercise (RE, based on squat-type exercise for rodents, with control of training variables. We developed an operant conditioning system composed of sound, light and feeding devices that allowed optimized RE performance by the animal. With this system, it is not necessary to impose fasting or electric shock for the animal to perform the task proposed (muscle contraction. Furthermore, it is possible to perform muscle function tests in vivo within the context of the exercise proposed and control variables such as intensity, volume (sets and repetitions, and exercise session length, rest interval between sets and repetitions, and concentric strength. Based on the experiments conducted, we demonstrated that the model proposed is able to perform more specific control of other RE variables, especially rest interval between sets and repetitions, and encourages the animal to exercise through short-term energy restriction and “disturbing” stimulus that do not promote alterations in body weight. Therefore, despite experimental limitations, we believe that this RE apparatus is closer to the physiological context observed in humans.

  13. Experimental model of a wind energy conversion system

    Science.gov (United States)

    Vasar, C.; Rat, C. L.; Prostean, O.

    2018-01-01

    The renewable energy domain represents an important issue for the sustainable development of the mankind in the actual context of increasing demand for energy along with the increasing pollution that affect the environment. A significant quota of the clean energy is represented by the wind energy. As a consequence, the developing of wind energy conversion systems (WECS) in order to achieve high energetic performances (efficiency, stability, availability, competitive cost etc) represents a topic of permanent actuality. Testing and developing of an optimized control strategy for a WECS direct implemented on a real energetic site is quite difficult and not cost efficient. Thus a more convenient solution consists in a flexible laboratory setup which requires an experimental model of a WECS. Such approach would allow the simulation of various real conditions very similar with existing energetic sites. This paper presents a grid-connected wind turbine emulator. The wind turbine is implemented through a real-time Hardware-in-the-Loop (HIL) emulator, which will be analyzed extensively in the paper. The HIL system uses software implemented in the LabVIEW programming environment to control an ABB ACS800 electric drive. ACS800 has the task of driving an induction machine coupled to a permanent magnet synchronous generator. The power obtained from the synchronous generator is rectified, filtered and sent to the main grid through a controlled inverter. The control strategy is implemented on a NI CompactRIO (cRIO) platform.

  14. Helicopter noise in hover: Computational modelling and experimental validation

    Science.gov (United States)

    Kopiev, V. F.; Zaytsev, M. Yu.; Vorontsov, V. I.; Karabasov, S. A.; Anikin, V. A.

    2017-11-01

    The aeroacoustic characteristics of a helicopter rotor are calculated by a new method, to assess its applicability in assessing rotor performance in hovering. Direct solution of the Euler equations in a noninertial coordinate system is used to calculate the near-field flow around the spinning rotor. The far-field noise field is calculated by the Ffowcs Williams-Hawkings (FW-H) method using permeable control surfaces that include the blade. For a multiblade rotor, the signal obtained is duplicated and shifted in phase for each successive blade. By that means, the spectral characteristics of the far-field noise may be obtained. To determine the integral aerodynamic characteristics of the rotor, software is written to calculate the thrust and torque characteristics from the near-field flow solution. The results of numerical simulation are compared with experimental acoustic and aerodynamic data for a large-scale model of a helicopter main rotor in an open test facility. Two- and four-blade configurations of the rotor are considered, in different hover conditions. The proposed method satisfactorily predicts the aerodynamic characteristics of the blades in such conditions and gives good estimates for the first harmonics of the noise. That permits the practical use of the proposed method, not only for hovering but also for forward flight.

  15. Total laparoscopic gastrocystoplasty: experimental technique in a porcine model

    Directory of Open Access Journals (Sweden)

    Frederico R. Romero

    2007-02-01

    Full Text Available OBJECTIVE: Describe a unique simplified experimental technique for total laparoscopic gastrocystoplasty in a porcine model. MATERIAL AND METHODS: We performed laparoscopic gastrocystoplasty on 10 animals. The gastroepiploic arch was identified and carefully mobilized from its origin at the pylorus to the beginning of the previously demarcated gastric wedge. The gastric segment was resected with sharp dissection. Both gastric suturing and gastrovesical anastomosis were performed with absorbable running sutures. The complete procedure and stages of gastric dissection, gastric closure, and gastrovesical anastomosis were separately timed for each laparoscopic gastrocystoplasty. The end-result of the gastric suturing and the bladder augmentation were evaluated by fluoroscopy or endoscopy. RESULTS: Mean total operative time was 5.2 (range 3.5 - 8 hours: 84.5 (range 62 - 110 minutes for the gastric dissection, 56 (range 28 - 80 minutes for the gastric suturing, and 170.6 (range 70 to 200 minutes for the gastrovesical anastomosis. A cystogram showed a small leakage from the vesical anastomosis in the first two cases. No extravasation from gastric closure was observed in the postoperative gastrogram. CONCLUSIONS: Total laparoscopic gastrocystoplasty is a feasible but complex procedure that currently has limited clinical application. With the increasing use of laparoscopy in reconstructive surgery of the lower urinary tract, gastrocystoplasty may become an attractive option because of its potential advantages over techniques using small and large bowel segments.

  16. COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS

    Energy Technology Data Exchange (ETDEWEB)

    Paul Lam; Dimitri Gidaspow

    2000-09-01

    The objective if this study was to develop a predictive experimentally verified computational fluid dynamics (CFD) model for gas-liquid-solid flow. A three dimensional transient computer code for the coupled Navier-Stokes equations for each phase was developed. The principal input into the model is the viscosity of the particulate phase which was determined from a measurement of the random kinetic energy of the 800 micron glass beads and a Brookfield viscometer. The computed time averaged particle velocities and concentrations agree with PIV measurements of velocities and concentrations, obtained using a combination of gamma-ray and X-ray densitometers, in a slurry bubble column, operated in the bubbly-coalesced fluidization regime with continuous flow of water. Both the experiment and the simulation show a down-flow of particles in the center of the column and up-flow near the walls and nearly uniform particle concentration. Normal and shear Reynolds stresses were constructed from the computed instantaneous particle velocities. The PIV measurement and the simulation produced instantaneous particle velocities. The PIV measurement and the simulation produced similar nearly flat horizontal profiles of turbulent kinetic energy of particles. This phase of the work was presented at the Chemical Reaction Engineering VIII: Computational Fluid Dynamics, August 6-11, 2000 in Quebec City, Canada. To understand turbulence in risers, measurements were done in the IIT riser with 530 micron glass beads using a PIV technique. The results together with simulations will be presented at the annual meeting of AIChE in November 2000.

  17. Clinical and histologic study of autogenous oral mucosa in experimental lamellar ketatoplasty/ Estudo clínico e histológico da mucosa oral autógena na ceratoplastia lamelar experimental

    Directory of Open Access Journals (Sweden)

    Vinícius Rivera Cardoso Prado

    2004-05-01

    feasible option for tectonic and reconstructive means in dogs.Oito cães sem raça definida, machos, com peso corpóreo médio de 12,4 kg, foram submetidos a procedimentos cirúrgicos de retirada de fragmento da mucosa oral com auxílio de trépano de 5 mm com posterior aplicação sobre lesão corneana de 4,5 mm de diâmetro, produzida em um dos olhos, aplicando-se sutura simples interrompida com fio de náilon 9-0. Os animais foram divididos em 4 grupos compostos por 2 animais, para estudo histológico aos 15, 30, 45, 60 dias de pós-operatório. Simultaneamente, realizou-se estudo clínico nos períodos de 0-2 dias, 3-7 dias, 8-15 dias, 16-30 dias e 31-60 dias de pós-operatório. Blefarospasmo e quemose foram mais intensos nos períodos iniciais e opacidade corneana e vascularização (da córnea e enxerto nos períodos intermediários, ambos com tendência de regressão nos períodos tardios. A secreção predominante foi seromucosa, sendo mais incidente nas fases iniciais e intermediárias com ausência nos tardios. Clinicamente, a integração do enxerto foi verificada no 15º dia. O estudo microscópico revelou para os períodos iniciais e intermediários intensa fibroplasia e deposição de fibras colágenas em arranjo desorganizado e vascularização do enxerto de intensa a leve entre 15º e 30º dia. Infiltrado polimorfonuclear foi observado no 15º dia, em grau discreto. Infiltrado linfoplasmocitário foi predominantemente, em grau discreto a moderado, entre o 30º e 60º dia. No 60º dia, observou-se epitelização compacta com projeções para o estroma, presença moderada de fibrócitos, colágeno em disposição mais organizada e vascularização discreta a ausente. Diante dos resultados admite-se a técnica de ceratoplastia com o emprego da mucosa bucal como opção eficiente para fins tectônicos e reconstrutivos em cães.

  18. Application of iterative robust model-based optimal experimental design for the calibration of biocatalytic models.

    Science.gov (United States)

    Van Daele, Timothy; Gernaey, Krist V; Ringborg, Rolf H; Börner, Tim; Heintz, Søren; Van Hauwermeiren, Daan; Grey, Carl; Krühne, Ulrich; Adlercreutz, Patrick; Nopens, Ingmar

    2017-09-01

    The aim of model calibration is to estimate unique parameter values from available experimental data, here applied to a biocatalytic process. The traditional approach of first gathering data followed by performing a model calibration is inefficient, since the information gathered during experimentation is not actively used to optimize the experimental design. By applying an iterative robust model-based optimal experimental design, the limited amount of data collected is used to design additional informative experiments. The algorithm is used here to calibrate the initial reaction rate of an ω-transaminase catalyzed reaction in a more accurate way. The parameter confidence region estimated from the Fisher Information Matrix is compared with the likelihood confidence region, which is not only more accurate but also a computationally more expensive method. As a result, an important deviation between both approaches is found, confirming that linearization methods should be applied with care for nonlinear models. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1278-1293, 2017. © 2017 American Institute of Chemical Engineers.

  19. Comparison of Laboratory Experimental Data to XBeach Numerical Model Output

    Science.gov (United States)

    Demirci, Ebru; Baykal, Cuneyt; Guler, Isikhan; Sogut, Erdinc

    2016-04-01

    generating data sets for testing and validation of sediment transport relationships for sand transport in the presence of waves and currents. In these series, there is no structure in the basin. The second and third series of experiments were designed to generate data sets for development of tombolos in the lee of detached 4m-long rubble mound breakwater that is 4 m from the initial shoreline. The fourth series of experiments are conducted to investigate tombolo development in the lee of a 4m-long T-head groin with the head section in the same location of the second and the third tests. The fifth series of experiments are used to investigate tombolo development in the lee of a 3-m-long rubble-mound breakwater positioned 1.5 m offshore of the initial shoreline. In this study, the data collected from the above mentioned five experiments are used to compare the results of the experimental data with XBeach numerical model results, both for the "no-structure" and "with-structure" cases regarding to sediment transport relationships in the presence of only waves and currents as well as the shoreline changes together with the detached breakwater and the T-groin. The main purpose is to investigate the similarities and differences between the laboratory experimental data behavior with XBeach numerical model outputs for these five cases. References: Baykal, C., Sogut, E., Ergin, A., Guler, I., Ozyurt, G.T., Guler, G., and Dogan, G.G. (2015). Modelling Long Term Morphological Changes with XBeach: Case Study of Kızılırmak River Mouth, Turkey, European Geosciences Union, General Assembly 2015, Vienna, Austria, 12-17 April 2015. Gravens, M.B. and Wang, P. (2007). "Data report: Laboratory testing of longshore sand transport by waves and currents; morphology change behind headland structures." Technical Report, ERDC/CHL TR-07-8, Coastal and Hydraulics Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS. Roelvink, D., Reniers, A., van Dongeren, A., van Thiel de

  20. Desorption of plutonium from montmorillonite: An experimental and modeling study

    Science.gov (United States)

    Begg, James D.; Zavarin, Mavrik; Kersting, Annie B.

    2017-01-01

    Desorption of plutonium (Pu) will likely control the extent to which it is transported by mineral colloids. We evaluated the adsorption/desorption behavior of Pu on SWy-1 montmorillonite colloids at pH 4, pH 6, and pH 8 using batch adsorption and flow cell desorption experiments. After 21 days adsorption, Pu(IV) affinity for montmorillonite displayed a pH dependency, with Kd values highest at pH 4 and lowest at pH 8. The pH 8 experiment was further allowed to equilibrate for 6 months and showed an increase in Kd, indicating that true sorption equilibrium was not achieved within the first 21 days. For the desorption experiments, aliquots of the sorption suspensions were placed in a flow cell, and Pu-free solutions were then pumped through the cell for a period of 12 days. Changes in influent solution flow rate were used to investigate the kinetics of Pu desorption and demonstrated that it was rate-limited over the experimental timescales. At the end of the 12-day flow cell experiments, the extent of desorption was again pH dependent, with pH 8 > pH 6 > pH 4. Further, at pH 8, less Pu was desorbed after an adsorption contact time of 6 months than after a contact time of 21 days, consistent with an aging of Pu on the clay surface. A conceptual model for Pu adsorption/desorption that incorporated known surface-mediated Pu redox reactions was used to fit the experimental data. The resulting rate constants indicated processes occurring on timescales of months and even years which may, in part, explain observations of clay colloid-facilitated Pu transport on decadal timescales. Importantly, however, our results also imply that migration of Pu adsorbed to montmorillonite colloids at long (50-100 year) timescales under oxic conditions may not be possible without considering additional phenomena, such as co-precipitation.

  1. A comprehensive experimental and modeling study of isobutene oxidation

    KAUST Repository

    Zhou, Chong-Wen

    2016-03-17

    Isobutene is an important intermediate in the pyrolysis and oxidation of higher-order branched alkanes, and it is also a component of commercial gasolines. To better understand its combustion characteristics, a series of ignition delay time (IDT) and laminar flame speed (LFS) measurements have been performed. In addition, flow reactor speciation data recorded for the pyrolysis and oxidation of isobutene is also reported. Predictions of an updated kinetic model described herein are compared with each of these data sets, as well as with existing jet-stirred reactor (JSR) species measurements. IDTs of isobutene oxidation were measured in four different shock tubes and in two rapid compression machines (RCMs) under conditions of relevance to practical combustors. The combination of shock tube and RCM data greatly expands the range of available validation data for isobutene oxidation models to pressures of 50 atm and temperatures in the range 666–1715 K. Isobutene flame speeds were measured experimentally at 1 atm and at unburned gas temperatures of 298–398 K over a wide range of equivalence ratios. For the flame speed results, there was good agreement between different facilities and the current model in the fuel-rich region. Ab initio chemical kinetics calculations were carried out to calculate rate constants for important reactions such as H-atom abstraction by hydroxyl and hydroperoxyl radicals and the decomposition of 2-methylallyl radicals. A comprehensive chemical kinetic mechanism has been developed to describe the combustion of isobutene and is validated by comparison to the presently considered experimental measurements. Important reactions, highlighted via flux and sensitivity analyses, include: (a) hydrogen atom abstraction from isobutene by hydroxyl and hydroperoxyl radicals, and molecular oxygen; (b) radical–radical recombination reactions, including 2-methylallyl radical self-recombination, the recombination of 2-methylallyl radicals with

  2. Solar-Powered Desalination: A Modelling and Experimental Study

    Science.gov (United States)

    Leblanc, Jimmy; Andrews, John

    2007-10-01

    materials were investigated: copper-nickel and a commercially available plastic. The modelling and design of a three effects MEE system is also discussed. The effects of the important design and operating parameters (recovery ratio, thermal energy, parasitic electrical energy, distillate production and solar collection area) controlling the cost of fresh water determined both from the computer simulation and experimental results are presented and analysed in this paper. Future work in the overall research program is also outlined.

  3. Therapeutic trial in experimental tegumentary leishmaniasis caused by Leishmania (Leishmania amazonensis. A comparative study between mefloquine and aminosidine Ensaio terapêutico na leishmaniose tegumentar experimental causada por Leishmania (Leishmania amazonensis. Um estudo comparativo entre mefloquina e aminosidine

    Directory of Open Access Journals (Sweden)

    Letícia Oba Galvão

    2000-08-01

    Full Text Available One hundred and eighty-two male inbred C57/BL/6 mice were infected with 3 x 106 Leishmania (Leishmania amazonensis promastigotes of the MHOM/BR/PH8 strain by means of a subcutaneous injection in the right ear. The animals were separated in three groups: 1 oral mefloquine hydrochloride treatment (16mg/kg/day/10 days, 2 intramuscular aminosidine (Paromomycin® treatment (20mg/kg/20 days and 3 control. Twenty six mice of each treated group were sacrificed, one at the end of treatment (nine weeks after inoculation, and one six weeks later (fifteen weeks after inoculation. Control Group animals were sacrificed at weeks six, nine and fifteen after inoculation. There was no significant difference between Group 1 (mefloquine and Group 3 (control subjects. Group 2 animals (aminosidine presented the smallest differences of all, both at the end of the treatment and six weeks later. The histopato-logical parameters have shown the following findings: a there was no significant difference between the mefloquine treated group and the control group; the group treated with aminosidine showed fewer of vacuolated macrophages than the control group, at week 9 (end of treatment. b both at the end of treatment and six weeks later, evaluation of tissue necrosis and tissue fibrosis revealed no differences between the treated groups. It was found that six weeks after the end of treatment, mice in the control group presented significantly more severe degrees of fibrosis than mice in the other groups. It can be concluded that mefloquine showed limited therapeutic effect in this experimental model, whereas aminosidine had a significant effect. Nevertheless, neither of them resulted in cure of the lesions.Foram utilizados 182 camundongos machos, isogênicos, da linhagem C57BL/6 inoculados na orelha direita com 3,0 x 10(6 formas promastigotas da cepa MHOM/BR/PH8 de Leishmania (Leishmania amazonensis. Os animais foram separados em três grupos: 1 52 animais tratados com

  4. Energy transfer in photosynthesis: experimental insights and quantitative models

    NARCIS (Netherlands)

    van Grondelle, R.; Novoderezhkin, V.

    2006-01-01

    We overview experimental and theoretical studies of energy transfer in the photosynthetic light-harvesting complexes LH1, LH2, and LHCII performed during the past decade since the discovery of high-resolution structure of these complexes. Experimental findings obtained with various spectroscopic

  5. Numerical Modeling and Experimental Testing of a Wave Energy Converter

    DEFF Research Database (Denmark)

    Zurkinden, Andrew Stephen; Kramer, Morten; Ferri, Francesco

    numerical values for comparison with the experimental test results which were carried out in the same time. It is for this reason why Chapter 4 does consist exclusively of numerical values. Experimental values and measured time series of wave elevations have been used throughout the report in order to a...

  6. Comportamento hemodinâmico e metabólico do choque hemorrágico: estudo experimental no cão Comportamiento hemodinámico y metabólico del choque hemorrágico: estudio experimental en el can Hemorrhagic shock hemodynamic and metabolic behavior: experimental study in dogs

    Directory of Open Access Journals (Sweden)

    José Fernando Amaral Meletti

    2003-09-01

    ón significativa de la FC solamente en M6; caída de la PAM, IC, IS y ITSVE a cada momento estudiado; discreta alteración de la PVC y PCP en cada momento; diminución de la PvO2 y de la SvO2 en los momentos estudiados; reducción del DO2, estabilización del VO2 y elevación de la TEO2 en los momentos; el I. choque presentó elevación hasta M3, caída en M4 y nueva elevación hasta M6; el IRVS se elevó hasta M4, quedó inalterado en M5 y presentó caída significativa en M6; el lactato presentó elevaciones a partir de M5 y M6. CONCLUSIONES: Se consideró que la presión arterial media, frecuencia cardíaca, presión venosa central y presión capilar pulmonar no reflejan el real estado volemico de los canes en nuestro modelo experimental y que el transporte, consumo y la tasa de extracción de oxígeno son parámetros útiles en la determinación de la reversibilidad y pronóstico del choque hemorrágico.BACKGROUND AND OBJECTIVES: Different experimental models have been used to illustrate hemodynamic and metabolic changes during hemorrhagic shock. This study aimed at observing hemodynamic and metabolic behaviors during a sequential and progressive model of hemorrhagic shock in dogs to determine which indices are earlier changed. METHODS: The study involved 13 dogs under total intravenous anesthesia with sodium pentobarbital, standard ventilation and previously splenectomized. Animals were not hydrated and bleeding velocity was dictated by animals’ blood pressure. Evaluated parameters were: hemodynamic (heart rate - HR, mean blood pressure - MBP, systemic vascular resistance index - SVRI, stroke index - SI, cardiac index - CI, shock index - i.Shock, left ventricular stroke work index - LVSWI, pulmonary capillary pressure - PCP, central venous pressure - CVP; and metabolic (mixed venous saturation - SvO2, venous oxygen pressure - PvO2, oxygen transport - O2T, oxygen consumption - VO2, oxygen extraction - TEO2, serum lactate. Results and parameters were evaluated in 6 different

  7. Formation of Large-Amplitude Wave Groups in an Experimental Model Basin

    National Research Council Canada - National Science Library

    Bassler, Christopher C; Lang, Gerritt E; Lee, Sang S; Carneal, Jason B; Park, Joel T; Dipper, Jr., Martin J

    2008-01-01

    .... Proving the feasibility of generating asymmetric large-amplitude wave groups in an experimental basin is the first step in the development of an experimental test technique that ensures a model...

  8. Experimental Verification of a Systematic Method for Identifying Contact-Dynamics Model Parameters

    National Research Council Canada - National Science Library

    Ma, Ou; Kim, Jong; Martinez, Lucas

    2007-01-01

    This project is aimed at conducting an experimental test of a new and systematic method for identifying the key parameters of a general multiple-point contact dynamics model using a robotics-based experimental testbed...

  9. Estudo morfológico da polpa de molares de ratos Wistar frente a uma oclusão traumática experimental Morphological study of the pulp of Wistar rats molars under experimental occlusal interference

    Directory of Open Access Journals (Sweden)

    Luiz Alberto Plácido PENNA

    2000-06-01

    Full Text Available As alterações morfológicas pulpares, decorrentes de um estímulo externo experimental (interferência oclusal, foram estudadas, em nível de microscopia de luz. Utilizaram-se restaurações de amálgama, em sobreoclusão nos primeiros molares superiores direitos de dez ratos Wistar, divididos em 3 grupos e sacrificados por perfusão transcardíaca com formol a 10%, aos 10, 20 e 30 dias. A avaliação foi feita nos molares inferiores direitos (lado experimental e esquerdos (lado controle. As peças ósseas após descalcificação em solução de EDTA associada às microondas, seguiram técnica histológica de rotina e coloração por hematoxilina-eosina e tricrômico de Mallory. Verificou-se no lado controle uma reação intensa caracterizada por um posicionamento atípico dos odontoblastos, seguida pelo aparecimento de cálculos pulpares e posteriormente por uma aparente e uniforme acomodação tecidual em toda a polpa, com moderada incidência de fibras colágenas. No lado experimental, as alterações foram similares parecendo, porém, aumentar com o tempo, principalmente aos 30 dias, onde a imagem histológica era semelhante à do lado controle aos 10 dias. Os resultados obtidos permitiram concluir que a interferência oclusal provocou alterações no tecido conjuntivo pulpar tanto no lado experimental como no controle e que as mesmas foram proporcionais à direção dos movimentos mandibulares.Pulpal morphological alterations in mandibular molars of rats, resulting from an experimental external stimulus (occlusal interference, were studied using light microscopy. We placed amalgam restorations in supraocclusion in the right superior first molars of 10 Wistar rats divided into three groups, which were sacrificed by transcardiac perfusion with 10% formalin, after 10, 20 and 30 days. The evaluation of the right (experimental side and left (control side inferior molars was made after decalcification of the bony specimens with EDTA solution

  10. Immunorestorative effect of thymostimulin on surgery immunodepression: experimental model.

    Science.gov (United States)

    García-Lechuz, J M; Navarro, M; Morandeira, M J; Soria, J; Román, A; Güemes, A; Salinas, J C; Lozano, R

    1993-01-01

    The purpose of the present study is to ascertain the immunorestorative effect of two different drugs on immunodepression induced by small bowel surgical resection in an experimental model. The potential immunorestorative effect has been measured by the ability of the drug to avoid the delay of skin allograft rejection induced by surgery and the inhibition of CD4/CD8 index changes induced by surgery in spleen tissue. 120 Wistar-Furth rats (age 12-16 weeks) anesthetized with a single intramuscular dose of ketamine (25 mg), diazepine (4 mg) and atropine (0.1 mg) were allotted to two main groups. One group received a skin graft (SG) from Fisher 344 rats and was treated with placebo, Inmunoferón (AM-3 polypeptidic drug) or TP-1 (thymostimulin) before the experiment (groups I, II, III) or treated with placebo, Inmunoferón or TP-1 before the experiment and underwent enterectomy and anastomosis (groups IV, V, VI). On the 2nd, 5th and 8th postoperative days, biopsies of the SG were taken and the signs of rejection were microscopically studied and evaluated by a pathologist as zero, incipient, moderate or massive. The other group was treated similarly, but the animals did not receive a SG and were splenectomized 5 days later. CD4 and CD8 lymphocyte subpopulations were identified by means of immunoperoxidase technique and monoclonal antibodies. Thymostimulin is able to stimulate the presence of SG rejection signs on the 2nd postoperative day in nonenterectomized animals and on the 8th postoperative day in nonenterectomized animals and on the 8th postoperative day in enterectomized rats and is able to avoid the decrease of the CD4/CD8 index in spleen tissue after surgical immunodepression.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Electro-acupuncture reduces the need for additional anesthetics in experimental studies Eletroacupuntura reduz a necessidade de doses adicionais de anestésicos em estudos experimentais

    Directory of Open Access Journals (Sweden)

    Agamenon Honório Silva

    2010-08-01

    Full Text Available PURPOSE: To evaluate the possible beneficial effects of electro-acupuncture in rats subjected to ketamine/xylazine (KX intra-peritoneal (i.p. anesthesia. METHODS: Forty-eight male Wistar rats were distributed in four equal groups. All rats received i.p. injections of ketamine (90 mg/kg +xylazine (10 mg/kg anesthesia. Basal values group (control rats (BV received no additional treatment. The equivalent of the human right ST36 (Zusanli and CV-12(Zhongwan acupoints were chosen for needling and electrical stimulation. AC rats were needled with sterilized disposable stainless steel needles at right ST36 and CV12 acupoints; needles were retained for 30 minutes. EAC10 rats, after needle insertion as described, had electrodes connected to both needles and to an electro stimulator model NKL EL-608; pulsed square waves, 10 Hz, 10 mA, was applied for 30 minutes. EAC100 rats were submitted to EA as described. However, a greater frequency (100 Hz was used. RESULTS: Thirty-seven rats remained under adequate anesthetic level during the experiment. However, maintenance anesthesia was required by 11 rats. Need for additional anesthesia decreased to 9.1% in EAC100 rats compared to BV (36.3%. CONCLUSION: Both the AC and the EAC10/100 prolong the anesthetic effect of the combination Ketamine-xylazine in rats, allowing longer duration of anesthesia with a lower dose of anesthetic, thereby reducing the occurrence of complications.OBJETIVO: Avaliar os possíveis efeitos benéficos da eletroacupuntura em ratos submetidos à anestesia intraperitoneal (i.p. com ketamina / xilazina. MÉTODOS: Quarenta e oito ratos Wistar foram randomizados em quatro grupos iguais. Todos os ratos receberam injeções i.p. de ketamina (90 mg / kg + xilazina (10 mg / kg. Os ratos do grupo Valores Basais (controle - BV não receberam nenhum tratamento adicional. Os acupontos equivalentes aos humanos E-36 (Zusanli e VC-12 (Zhongwan foram escolhidos para inserção de agulhas e estimulação el

  12. O uso da matriz óssea desmineralizada na reparação de lesões osteocondrais: estudo experimental em coelhos The use of demineralized bone matrix in the repair of osteochondral lesions: experimental study in rabbits

    Directory of Open Access Journals (Sweden)

    Aldo José Fernando da Costa

    2001-12-01

    Full Text Available Este estudo teve como finalidade a avaliação do uso de matriz óssea desmineralizada na reparação de lesões osteocondrais. A cartilagem articular tem pequena capacidade regenerativa devido a suas características histológicas e à ausência de vasos sanguíneos. Implantes teciduais e cultura de células condrogênicas foram utilizadas para o tratamento de lesões osteocondrais, porém trazem dificuldades técnicas na fixação e suporte mecânico da região subcondral. A matriz óssea desmineralizada pode facilitar tecnicamente a fixação destes implantes em razão de ser um material firme, porém com características elásticas. Além de ter capacidade osteogênica e produzir osso subcondral, assim funcionando como suporte mecânico, também tem fatores indutores de condrogênese. Lesões osteocondrais foram produzidas em joelhos de 15 coelhos. Os joelhos esquerdos foram tratados com matriz óssea desmineralizada, e os direitos usados como controle comparativo. Realizaram-se avaliações macroscópicas e histológicas nas semanas 02, 04 e 06. Nas lesões tratadas com matriz óssea desmineralizada foi obtido 100% de viabilidade do enxerto e formação de tecido normal de reparação, o qual preencheu a lesão completamente com matriz óssea desmineralizada. A análise histológica demonstrou neoformação óssea e integração do enxerto com o tecido ósseo da região subcondral, e na região superficial da lesão ocorrera a indução de formação de tecido condrogênico. A conclusão deste estudo é que a matriz óssea desmineralizada é útil na reparação de lesões osteocondrais devido a sua capacidade de indução óssea e indução de formação de tecido condrogênico. Pode ser usada no tratamento de lesões osteocondrais como componente de um enxerto composto com tecido condrogênico ou cultura de células condrogênicas. Pode também diminuir as dificuldades técnicas de fixação e suporte estes implantes.This study evaluated

  13. COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS

    Energy Technology Data Exchange (ETDEWEB)

    Paul C.K. Lam; Isaac K. Gamwo; Dimitri Gidaspow

    2002-05-01

    The objective of this study was to develop a predictive experimentally verified computational fluid dynamics (CFD) model for gas-liquid-solid flow. A three dimensional transient computer code for the coupled Navier-Stokes equations for each phase was developed and is appended in this report. The principal input into the model is the viscosity of the particulate phase which was determined from a measurement of the random kinetic energy of the 800 micron glass beads and a Brookfield viscometer. The details are presented in the attached paper titled ''CFD Simulation of Flow and Turbulence in a Slurry Bubble Column''. This phase of the work is in press in a referred journal (AIChE Journal, 2002) and was presented at the Fourth International Conference on Multiphase Flow (ICMF 2001) in New Orleans, May 27-June 1, 2001 (Paper No. 909). The computed time averaged particle velocities and concentrations agree with Particle Image Velocimetry (PIV) measurements of velocities and concentrations, obtained using a combination of gamma-ray and X-ray densitometers, in a slurry bubble column, operated in the bubbly-coalesced fluidization regime with continuous flow of water. Both the experiment and the simulation show a down-flow of particles in the center of the column and up-flow near the walls and nearly uniform particle concentration. Normal and shear Reynolds stresses were constructed from the computed instantaneous particle velocities. The PIV measurement and the simulation produced instantaneous particle velocities. The PIV measurement and the simulation produced similar nearly flat horizontal profiles of turbulent kinetic energy of particles. To better understand turbulence we studied fluidization in a liquid-solid bed. This work was also presented at the Fourth International Conference on Multiphase Flow (ICMF 2001, Paper No. 910). To understand turbulence in risers, measurements were done in the IIT riser with 530 micron glass beads using a PIV

  14. Desenvolvimento de uma órtese de Dumon modificada para aplicações traqueais: um estudo experimental em cães Development of a modified Dumon stent for tracheal applications: an experimental study in dogs

    Directory of Open Access Journals (Sweden)

    Rogério Gastal Xavier

    2008-01-01

    Full Text Available OBJETIVO: Descrever o desenvolvimento de uma órtese de silicone e os testes in vivo de compatibilidade e aplicabilidade na traquéia canina normal. MÉTODOS: Quatro densidades de silicone foram testadas para a obtenção de protótipos. Para cada densidade, foi calculada a pressão exigida para causar a compressão, considerando-se uma área de contato de 1 cm² e uma redução de 30% no diâmetro. A densidade selecionada foi 70-75 Shore A hardness. Adicionou-se sulfato de bário em pó ao silicone para tornar a órtese desenvolvida radiopaca e facilmente identificável ao exame radiológico. A órtese desenvolvida apresenta superfície externa corrugada com arcos salientes e descontínuos, semelhantes aos anéis traqueobrônquicos, para intercalação e fixação nas vias aéreas inferiores, superfície interna polida e extremidades lisas que evitam o dano por fricção. O protótipo considerado como sendo o mais adequado em termos de rigidez e flexibilidade foi implantado broncoscopicamente em traquéias caninas normais. Os animais foram sacrificados após oito semanas, e a traquéia foi removida para análise anatomopatológica. RESULTADOS: Não houve complicações após a implantação das órteses. Nenhuma precisou ser removida, e todas estavam bem posicionadas ao final de oito semanas. O estudo histopatológico mostrou que a membrana basal epitelial foi preservada. Foram observados pontos focais de desnudamento epitelial, leve infiltrado inflamatório sob a mucosa e, mais raramente, tecido de granulação com neoformação vascular e ausência de microorganismos. CONCLUSÕES: A órtese desenvolvida mostrou resistência aos esforços mecânicos e biocompatibilidade, não provocando reação tecidual adversa na traquéia canina, além de permanecer íntegra ao final do experimento.OBJECTIVE: To describe the development of a silicone stent and perform in vivo testing for biocompatibility/applicability in the normal canine trachea. METHODS

  15. Estudo experimental da ação da metilprednisolona utilizada antes do traumatismo raquimedular em ratos Wistar Experimental study on the action of methylprednisolone on Wistar rats before spinal cord injury

    Directory of Open Access Journals (Sweden)

    Raphael Martus Marcon

    2010-01-01

    Full Text Available OBJETIVO: Avaliar os efeitos da metilprednisolona empregada previamente ao traumatismo medular, tanto em relação aos possíveis efeitos benéficos quanto às possíveis complicações associadas. MATERIAIS E MÉTODOS: Foram utilizados 32 ratos Wistar, divididos em 4 grupos. Dois grupos receberam as drogas A (placebo e B (metilprednisolona imediatamente após a lesão. Outros 2 grupos receberam as mesmas drogas 4 horas antes da lesão. Todos foram avaliados por um período de 28 dias quanto à função locomotora e complicações associadas. RESULTADOS: Os 4 grupos foram comparados quanto ao peso e idade. Não foi encontrada diferença estatisticamente significante entre os grupos de estudos quanto às médias de peso e de idade. Na comparação entre os 4 grupos quanto às intercorrências foi encontrada diferença estatisticamente significante nos óbitos (p = 0,047, onde o grupo Droga B T0 apresentou proporção de óbitos (0% significantemente menor do que a encontrada no grupo Droga B T-4 (55,6%. Não houve diferença estatística entre estres grupos quanto aos índides motores e quanto às complicações (p > 0,05 em todas as comparações. CONCLUSÕES: os animais tratados com metilprednisolona quatro horas antes do trauma apresentaram um número de óbitos significativamente maior quando comparados aos ratos tratados com a mesma droga após o trauma.OBJECTIVE: To evaluate the effects of methylprednisolone used prior to spinal injury, both in relation to possible beneficial effects and to possible associated complications. MATERIALS AND METHODS: The study subjects were 32 Wister rats, divided into 4 groups. Two groups received drugs A (placebo and B (methylprednisolone immediately after the injury. Another 2 groups received the same drugs 4 hours before the injury. They were all evaluated over a period of 28 days to verify locomotor function and associated complications. RESULTS: The 4 groups were compared in terms of weight and age. No

  16. Biópsia mamária realizada pela técnica de biópsia helicoide: estudo experimental Breast biopsy performed by the helicoid biopsy technique: an experimental study

    Directory of Open Access Journals (Sweden)

    Eliel de Souza

    2010-12-01

    Full Text Available OBJETIVO: avaliar o desempenho da biópsia helicoide na realização de biópsias mamárias. MÉTODOS: foi selecionado aleatoriamente uma amostra composta de 30 pacientes portadoras de câncer de mama submetidas à mastectomia. Foram excluídas as mulheres portadoras de tumor que tivessem consistência pétrea, não-palpável, com manipulação cirúrgica prévia ou que contivesse líquido. Utilizando-se o kit de biópsia helicoide e um equipamento de core biopsy com cânula e agulha de 14 gauge, respectivamente, coletou-se um fragmento por equipamento em área sã e nos tumores, em cada peça cirúrgica, totalizando 120 fragmentos para estudo histológico. Para a análise dos dados, definiu-se um nível de confiança de 95% e utilizou-se o software SPSS, versão 13; o índice de concordância Kappa e o teste paramétrico t de Student. RESULTADOS: a média das idades das pacientes foi de 51,6 anos (±11,1 anos. A core biopsy apresentou sensibilidade de 93,3%, especificidade de 100% e acurácia de 96,7%, enquanto a biópsia helicoide teve sensibilidade de 96,7%, especificidade de 100% e acurácia de 98,3%. Na comparação entre a histologia dos tumores e dos fragmentos de biópsias, houve alto grau de concordância nos diagnósticos (Kappa igual a 0,9, com pPURPOSE: to assess the helicoid biopsy performance when carrying out breast biopsies. METHODS: thirty patients with breast cancer submitted to mastectomy were selected at random. Women with a tumor of petreous consistency, nonpalpable, submitted to previous surgical manipulation or containing fluid were excluded. The helicoid biopsy kit and a core biopsy device with a cannula and a 14-gauge-needle, respectively, were used to collect a fragment each from a healthy area and from the tumor of each surgical specimen, for a total of 120 fragments for histological study. Data were analyzed statistically by the parametric Student's t-test and by the Kappa concordance index at the 95% confidence level

  17. Efeito da utilização de um centrifugado de medula óssea no tratamento de lesão muscular: estudo experimental em coelhos Effect of use of bone-marrow centrifugate on muscle injury treatment: experimental study on rabbits

    Directory of Open Access Journals (Sweden)

    Daniel Ferreira Fernandes Vieira

    2011-01-01

    Full Text Available OBJETIVO: O objetivo deste estudo foi de avaliar o efeito de um centrifugado de medula óssea na cicatrização de lesão muscular em coelhos. MÉTODOS: Este estudo experimental envolveu a utilização de 15 coelhos machos, adultos, da raça Nova Zelândia Branco. Em cada animal, realizou-se uma lesão transversal na região média do músculo tibial anterior direito, onde se adicionou uma esponja de colágeno absorvível, embebida em um centrifugado de aspirado de medula óssea do osso ilíaco ipsilateral. O membro posterior esquerdo foi utilizado como controle, sendo submetido à mesma lesão; porém, neste caso, adicionando-se somente a esponja de colágeno absorvível. Após 30 dias, os animais foram sacrificados para o estudo da cicatrização muscular. As áreas de cicatrização muscular foram submetidas à análise histológica com histomorfometria, interessando-se a mensuração do número de células musculares em regeneração por micrômetro quadrado e a proporção de fibrose formada. RESULTADOS: O método de centrifugação utilizado neste estudo resultou em uma concentração média de células nucleadas maior que o número destas células nos aspirados originais, sem provocar destruição celular significativa. A adição do centrifugado de medula óssea não resultou em aumento significante do número de células musculares em regeneração em relação ao grupo controle. Também não houve diferença significante na proporção de fibrose formada em relação ao grupo controle. CONCLUSÃO: A administração de centrifugado de medula óssea utilizada neste estudo não favoreceu a cicatrização de lesão muscular em coelhos.OBJECTIVE: The objective of this study was to evaluate the effect of bone-marrow centrifugate on the healing of muscle injuries in rabbits. METHODS: This experimental study involved use of fifteen adult male New Zealand White rabbits. Each animal received a transverse lesion in the middle of the right

  18. Influência da irrigação de soluções nutricionais no colo excluso de trânsito intestinal: estudo experimental em ratos Influence of irrigation of nutritional solutions in the colon excluded of fecal stream: experimental study in rats

    Directory of Open Access Journals (Sweden)

    Carlos Guilherme Giazzi Nassri

    2008-09-01

    Full Text Available A colite por exclusão é descrita como processo inflamatório que ocorre nos segmentos colorretais desprovidos do trânsito fecal. A deficiência dos ácidos graxos de cadeia curta vem sendo considerada como principal fator causal. OBJETIVO: O objetivo do presente estudo foi avaliar, em modelo experimental de colite de exclusão, a importância da irrigação do segmento desprovido de trânsito com soluções nutricionais na prevenção e tratamento do processo inflamatório. MÉTODO: Foram utilizados trinta ratos Wistar, machos, com peso inicial variando entre 350 e 500 gramas, submetidos à derivação do trânsito intestinal através da realização de colostomia proximal e fístula mucosa distal. Os animais foram divididos em três grupos de 10 animais segundo a irrigação do segmento excluso de trânsito ter sido realizada, empregando-se: Grupo SF: solução fisiológica a 0,9%; Grupo GH: solução de glicose a 50%; e Grupo AG: solução de ácidos graxos de cadeia curta. Em todos os animais, a irrigação do colo excluso foi realizada em intervalos de quatro dias sendo sacrificados sempre no 21º pós-operatório. Os fragmentos removidos dos segmentos intestinais foram corados pelas técnicas da hematoxilina-eosina e tricrômio de Masson. As variáveis histológicas estudadas foram: espessura da túnica mucosa, congestão vascular; infiltrado inflamatório e a deposição de colágeno. Os resultados encontrados foram submetidos a estudo estatístico considerando nível de significância de 5% (pDiversion colitis is described as an inflammatory process that occurs in the colorectal segments excluded of the fecal stream. The deficiency of the short-chain fatty acids inside of intestinal lumen was considered the main etiologic factor. AIM: The aim of the present study was valued, in experimental model of diversion colitis, the importance of the irrigation of the segment without fecal stream with nutritional solutions in prevention and

  19. Rat an experimental model for burns: A systematic review Rato como modelo experimental de queimadura: Revisão sistemática

    Directory of Open Access Journals (Sweden)

    Jorge Kiyoshi Mitsunaga Junior

    2012-06-01

    Full Text Available PURPOSE: To revise and systematize scientific knowledge of the experimental model for cutaneous burns in rats. METHODS: A bibliographical review from 2008 up to January 2011 in PubMed, EMBASE and LILACS was undertaken. Were used the keywords: animal models, burns and rats. 221 studies were identified, and 116 were selected. RESULTS: It was found that: 54/86 (62.7% had third degree burns; 55/73 (75.3% studied the back; 45/78 (57.6% used heated water and 27/78 (35.9% incandescent instruments; 39/78 (50% studied systemic effects; 22/71 (31% used ketamine associated with xylazine; 61/64 (95.3% performed depilation with appropriate equipment; 36/72 (50% used microscopy; more than 50% did not describe analgesia or antibiotics during the postoperative period; in 42/116 (36.2% postoperative fluid therapy was performed; and the time interval after the burn, up to the beginning of the results analysis varied from 7s up to four weeks. Legislation issues on burn experiments are discussed. CONCLUSION: The hot water was the main method to induce burns those of third degree on the back, with anesthesia using ketamine and xylazine, after depilation. These were evaluated microscopically, without using analgesia or an antibiotic during the postoperative period. The studies were not very reproducible.OBJETIVO: Revisar e sistematizar o conhecimento científico do modelo experimental em queimadura da pele em ratos. MÉTODOS: Revisão da literatura foi realizada de 2008 a Janeiro de 2011 na PubMed, EMBASE e LILACS. Os descritores usados foram: modelo animal, queimadura e ratos. 221 estudos foram identificados e 116 foram selecionados. RESULTADOS: Foi encontrado que: 54/86 (62,7% tinham queimadura de terceiro grau; 55/73 (75,3% estudaram o dorso; 45/78 (57.6% usaram líquido aquecido e 27/78 (35,9% usaram instrumento incandescente; 39/78 (50% estudaram efeitos sistêmicos; 22/71 (31% usaram ketamina associada a xilazina; 61/64 (95,3% realizaram depilação com

  20. Mechanisms of Osteoarthritic Pain. Studies in Humans and Experimental Models

    Directory of Open Access Journals (Sweden)

    Annett Eitner

    2017-11-01

    Full Text Available Pain due to osteoarthritis (OA is one of the most frequent causes of chronic pain. However, the mechanisms of OA pain are poorly understood. This review addresses the mechanisms which are thought to be involved in OA pain, derived from studies on pain mechanisms in humans and in experimental models of OA. Three areas will be considered, namely local processes in the joint associated with OA pain, neuronal mechanisms involved in OA pain, and general factors which influence OA pain. Except the cartilage all structures of the joints are innervated by nociceptors. Although the hallmark of OA is the degradation of the cartilage, OA joints show multiple structural alterations of cartilage, bone and synovial tissue. In particular synovitis and bone marrow lesions have been proposed to determine OA pain whereas the contribution of the other pathologies to pain generation has been studied less. Concerning the peripheral neuronal mechanisms of OA pain, peripheral nociceptive sensitization was shown, and neuropathic mechanisms may be involved at some stages. Structural changes of joint innervation such as local loss and/or sprouting of nerve fibers were shown. In addition, central sensitization, reduction of descending inhibition, descending excitation and cortical atrophies were observed in OA. The combination of different neuronal mechanisms may define the particular pain phenotype in an OA patient. Among mediators involved in OA pain, nerve growth factor (NGF is in the focus because antibodies against NGF significantly reduce OA pain. Several studies show that neutralization of interleukin-1β and TNF may reduce OA pain. Many patients with OA exhibit comorbidities such as obesity, low grade systemic inflammation and diabetes mellitus. These comorbidities can significantly influence the course of OA, and pain research just began to study the significance of such factors in pain generation. In addition, psychologic and socioeconomic factors may aggravate

  1. Estudo dos modelos assistenciais praticados por operadoras de planos privados de saúde Study of care models practiced by private operators of health plans

    Directory of Open Access Journals (Sweden)

    Rosiene Maria de Freitas

    2011-12-01

    Full Text Available Este estudo objetivou identificar a adoção, pelas operadoras, de modelos assistenciais que busquem a integralidade do cuidado, a partir da indução pela Agência Nacional de Saúde Suplementar (ANS. O universo foi composto por operadoras de planos de saúde atuantes no estado de Minas Gerais, nas modalidades autogestão, filantropia, medicina de grupo e cooperativa médica. As empresas foram descritas a partir dos cadastros da ANS. Foi realizada entrevista telefônica assistida por computador - ETAC - para obtenção de dados sobre o acesso dos beneficiários aos serviços, estruturação da rede e implantação de modelos segundo linhas materno-infantil, adulto/idoso, cardiovascular e neoplasias. Foram constatadas 182 empresas em atividade no estado; 108 foram elegíveis para o estudo; 27,1% das operadoras informaram ter implantado programas de cuidado na linha materno-infantil; 22,2%, na linha de cuidado ao adulto/idoso e 9,2% em neoplasias. Inadequadas estruturas internas e o pequeno porte da maioria das operadoras podem explicar, em parte, a dificuldade de implantação e modelos de atenção mais cuidadores. Ressalta-se a ampla margem de inovações ainda existente para a introdução dessas práticas por parte das operadoras.This study aimed to identify the adoption by private health insurance companies, from the induction by the Agência Nacional de Saúde Suplementar (ANS of models that foments integrality. The universe were companies in Minas Gerais, in the modalities self-management, philanthropy, group medicine and medical cooperative. The companies were described from ANS official registers. Also, was made a computer-assisted telephone interview - ETAC- which approached: the beneficiaries' access to services, the structuring of the network, and the introducion of care models on maternal and child health, adult/elderly, cardiovascular and cancer. There were found 182 companies in Minas Gerais; 108 were elegible; 27,1% reported the

  2. Alterações inflamatórias provocadas pelo metronidazol em feridas: estudo experimental em ratos Inflammatory alterations provoked by metronidazole in wounds: an experimental study in rats

    Directory of Open Access Journals (Sweden)

    Cláudia Paraguaçu Pupo Sampaio

    2009-09-01

    Full Text Available CONTEXTO: Cerca de 2,7% da população brasileira tem úlceras crônicas nos pés e nas pernas, porcentagem que chega a 10% nos diabéticos e que representa a segunda causa de afastamento do trabalho no Brasil. Isso demonstra a necessidade de se encontrar um produto de baixo custo que favoreça a cicatrização dessas feridas. OBJETIVO: Avaliar os efeitos do metronidazol na cicatrização de feridas por segunda intenção. MÉTODOS: Utilizaram-se 80 ratos machos, em cujos dorsos se produziu uma ferida, distribuindo-se, os animais, em dois grupos de 40. Os ratos do grupo-controle tiveram suas feridas tratadas com solução de NaCl 0,9%, e os pertencentes ao grupo-experimento, com metronidazol 4%. No terceiro, sétimo, 14º e 21º dias, avaliou-se o processo cicatricial por parâmetros macroscópicos, histológicos e imunoistoquímicos. RESULTADOS: A concentração de colágeno foi maior nas cicatrizes dos animais do grupo-experimento em todos os tempos examinados. A concentração de colágeno do tipo I também foi significante no sétimo dia (p = 0,020 e no 21º dia (p = 0,016. O colágeno tipo III mostrou concentração semelhante nos tempos iniciais e apresentou-se com maior concentração no 21º dia (p = 0,005. A angiogênese, avaliada pelo anti-CD34, demonstrou maior número de vasos, no grupo-experimento, com diferença significante no terceiro dia (p CONTEXT: Chronic feet and leg ulcers affect about 2.7% of the Brazilian population, 10% of diabetic patients. The condition represents the second most frequent cause of absence from work in Brazil. This shows the need for a product that promotes healing of these wounds at a low cost. OBJECTIVE: To evaluate the effects of metronidazole on ulcer healing by second intention. METHODS: Eighty male rats divided into two groups of 40 had a wound made on their dorsum. The control group was treated with a 0.9% NaCl solution and the experimental group was treated with 4% metronidazole. On the third

  3. Protector mechanisms of the association between gastroesophageal reflux disease and asthma: experimental study in rats Mecanismos protetores: doença do refluxo gastroesofágico e asma. Estudo experimental em ratos

    Directory of Open Access Journals (Sweden)

    Paula Yuri Sugishita Kanikadan

    2008-09-01

    éreas é uma das características que o indivíduo asmático desenvolve e diversos estudos associam o aumento da reatividade das vias aéreas com o refluxo gastroesofágico. OBJETIVO: Avaliar a reatividade à metacolina de traquéia exposta intraluminalmente ao suco gástrico de ratos submetidos a inflamação alérgica pulmonar. MÉTODOS: Grupos de ratos foram sensibilizados e broncoprovocados com ovoalbumina. Após 24 horas, os animais foram sacrificados e a traquéia removida para preenchimento de seu lúmen com suco gástrico obtido de um animal doador. A seguir, os segmentos foram colocados em placas plásticas com RPMI-1640 e mantidos em estufa por 3 horas em condições ambientais adequadas. Após o tempo de incubação, os fragmentos foram montados em cubas de vidro para órgão isolado para registro isométrico de contração, através da construção de curvas concentração-efeito à metacolina. RESULTADOS: Observou-se redução da resposta contrátil em traquéia exposta ao suco gástrico proveniente de ratos alérgicos. Os tratamentos farmacológicos com composto 48/80 e cromoglicato de sódio (bloqueio de mastócitos, L-NAME (inibidor de óxido nítrico, NO, capsaicina (depleção de neuropeptídios e indometacina (inibidor da ciclooxigenase corroboraram esta observação. CONCLUSÕES: Os resultados apontam para a existência de complexa interação entre a alergia pulmonar e o suco gástrico nas vias aéreas, com o envolvimento do sistema não-adrenérgico não-colinérgico, NO, prostanóides e mastócitos. À luz das evidências in vivo sobre a hiperreatividade das vias aéreas na associação asma e refluxo gastroesofágico, sugere-se que a reduzida resposta contrátil detectada in vitro pode representar um mecanismo protetor das vias aéreas. A despeito de sua presença, esta redução pode não ser observada in vivo devido à proeminência dos efeitos do sistema não-adrenérgico não-colinérgico excitatório.

  4. Prevenção de aderências pélvicas: estudo experimental em ratas com diferentes modalidades terapêuticas Pelvic adhesion prevention: experimental study on rats with different therapeutic agents

    Directory of Open Access Journals (Sweden)

    José Fernando Pacheco

    2003-06-01

    Full Text Available OBJETIVOS: avaliar o grau de aderências pélvicas em função do tempo e da utilização de diferentes substâncias empregadas na sua profilaxia. MATERIAL E MÉTODOS: estudo prospectivo com 120 ratas Wistar, albinas, virgens, 3 a 4 meses de idade, pesando aproximadamente 250 gramas, divididas aleatoriamente em 10 grupos de 12 animais cada: controle, sem lesão; lesões e sem tratamento; lesões + solução fisiológica 0,9%; lesões + Ringer-lactato; lesões + dextrano 70 a 32%; lesões + Ringer-lactato/heparina; lesões + Ringer-lactato/dexametasona; lesões + Ringer-lactato/hidrocortisona/dexametasona/ampicilina; lesões + Ringer-lactato/albumina e lesões + carboximetilcelulose 1%. Após anestesiados os animais, realizaram-se dois tipos de lesões nos cornos uterinos (escarificação e eletrocauterização, seguidos de tratamento profilático intraperitoneal com as soluções citadas. No 7º, 14º e 28º dia pós-operatório, momentos M1, M2 e M3, respectivamente, avaliaram-se quatro ratas de cada grupo quanto à presença de aderências. Os métodos empregados na quantificação das aderências encontradas basearam-se na classificação de Cohen, com escores variando de 0 a 4+ de acordo com a quantidade, características e localização das aderências. Foram usadas provas paramétricas para análise da variância e Kruskal-Wallis. RESULTADOS: os melhores tratamentos para prevenção de aderência pélvica em ratas foram: Ringer-lactato/dexametasona (predomínio do escore 1+, dextrano 70 a 32% (predomínio do escore 2+ e Ringer-lactato/hidrocortisona/dexametasona/ampicilina (predomínio do escore 2+. O período pós-operatório, representado pelo momento M3, e a técnica cirúrgica, predominantemente com escore 0, influíram na adesiólise e manutenção de aderências pélvicas em ratas. CONCLUSÕES: a prevenção de aderências pélvicas em ratas inicia-se no processo cirúrgico de baixo dano tecidual; o uso de substâncias profil

  5. Influência do antibiótico nas lesões de isquemia e reperfusão intestinal: estudo experimental em ratos The influence of antibiotics on intestinal ischemia and reperfusion: experimental study in rats

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Pessole Biondo-Simões

    2000-01-01

    Full Text Available Muito se tem questionado sobre os efeitos da isquemia intestinal seguida de reperfusão (I/R, chamando a atenção para o papel dos leucócitos na patobiologia da I/R. A fisiopatogenia das lesões está intimamente ligada à geração de radicais de oxigênio durante o período em que se processa a reperfusão. A ruptura da barreira intestinal permitindo a translocação bacteriana agravaria ainda mais estas lesões. Este estudo tem por objetivo avaliar as lesões intestinais na vigência de isquemia e na reperfusão com e sem antibioticoterapia. Submeteram-se 42 ratos Wistar à anestesia e laparotomia mediana. Obteve-se isquemia intestinal por clampeamento das artérias mesentéricas cranial e caudal por 30 minutos. Após reperfundiu-se por igual tempo. Metade destes animais receberam 50 mg/kg de eritromicina por via oral nas 24 horas que antecederam o procedimento. Cada um destes grupos foi subdividido em outros 3, constituíndo os subgrupos de controle, isquemia e isquemia/reperfusão. Ao final, ressecaram-se segmentos do intestins delgado para processamento histológico. Avaliaram-se os resultados pela escala de CHIU e col. e submeteram-se os resultados à tratamento estatístico. Observou-se que a mucosa intestinal apresentava-se com padrão normal nos grupos de controle, tanto com antibioticoprofilaxia como sem. Os intestinos submetidos à isquemia com ou se antibioticoprofilaxia mostraram, lesões com descolamento e perda de vilosidades até infartamento transmucoso. Os intestinos reperfundidos apresentavam lesões semelhantes. Verificou-se que os intestinos reperfundidos que receberam antibioticoprofilaxia apresentavam lesões mais graves do que os que sofreram isquemia sem antibioticoprofilaxia (p=0,0303. Concluiu-se que o uso de antibióticos pré-isquemia não diminui a gravidade das lesões histopatológicas da mucosa intestinal, não protegendo das lesões após a reperfusão.The role of the white blood cells in the ischemia and

  6. Profile construction in experimental choice designs for mixed logit models

    NARCIS (Netherlands)

    Sandor, Z; Wedel, M

    2002-01-01

    A computationally attractive model for the analysis of conjoint choice experiments is the mixed multinomial logit model, a multinomial logit model in which it is assumed that the coefficients follow a (normal) distribution across subjects. This model offers the advantage over the standard

  7. Model-robust experimental designs for the fractional polynomial ...

    African Journals Online (AJOL)

    Fractional polynomial response surface models are polynomial models whose powers are restricted to a small predefined set of rational numbers. Very often these models can give a good a fit to the data and much more plausible behavior between design points than the polynomial models. In this paper, we propose a ...

  8. Neural network model to control an experimental chaotic pendulum

    NARCIS (Netherlands)

    Bakker, R; Schouten, JC; Takens, F; vandenBleek, CM

    1996-01-01

    A feedforward neural network was trained to predict the motion of an experimental, driven, and damped pendulum operating in a chaotic regime. The network learned the behavior of the pendulum from a time series of the pendulum's angle, the single measured variable. The validity of the neural

  9. Melt pool modelling, simulation and experimental validation for SLM

    NARCIS (Netherlands)

    Wits, Wessel

    2017-01-01

    SLM parts are built by successively melting layers of powder in a powder bed. Process parameters are often optimized experimentally by laser scanning a number of single tracks and subsequently determining which settings lead to a good compromise between quality and build speed. However,

  10. Apendicite aguda: modelo experimental em coelhos Acute appendicitis: model experimental in rabbits

    Directory of Open Access Journals (Sweden)

    João EBRAM-NETO

    2000-04-01

    Full Text Available Com objetivo de estudar experimentalmente as diversas fases evolutivas da apendicite aguda, foram utilizados 60 coelhos (Oryctogalus cuniculus, fêmeas, da linhagem Nova Zelândia, com peso variando de 2510 a 3040 gramas. Os animais foram divididos em dois grupos denominados controle e experimento, e estes subdivididos em três subgrupos com períodos de observação de 12, 24 e 48 horas. No grupo experimento foi realizada a oclusão do lume apendicular por meio de sutura seromuscular circular a 8 cm da extremidade distal do apêndice cecal, com fio de polipropileno 4-0. No controle foi feita somente a simulação da cirurgia. Os aspectos macroscópicos (aumento do tamanho, necrose, perfuração, aderência e secreção na cavidade abdominal bem como os microscópicos do grupo experimento, evidenciaram uma progressão das alterações anatomopatológicas mostrando haver uma relação entre a intensidade dos achados histopatológicos e o tempo de observação. Conclui-se que o método utilizado causa apendicite aguda com alterações anatomopatológicas distintas, de acordo com a fase evolutiva da doença.The evolving phases of acute appendicitis were studied experimentally. Sixty female rabbits (Oryctogalus cuniculus of New Zealand lineage weighing about 2510 to 3040 g were divided in two groups: a control group and experimental group. The experimental group was divided into three subgroups for observation after 12, 24 and 48 hours of the operation, that consisted on a 4-0 polypropylene circular suture at 8 cm from the distal part of the cecal appendix. The control group was sham operated. The macroscopic exam (increase of the appendix volume, necrosis, perfuration, adherence and secretion in the abdominal cavity and the microscopic finding showed a progression in the anatomopathological alterations. There was a close relationship between the histopathological findings and time after the appendiceal obstruction. We conclude that the method

  11. THE MOUSE AS AN EXPERIMENTAL MODEL FOR TITYUS SERRULATUS SCORPION ENVENOMING

    Directory of Open Access Journals (Sweden)

    Mônica de Mônico Magalhães

    1998-10-01

    Full Text Available The scorpion toxin induces a number of physiological parameters alterations, as disturbance of cardiac rhythm, heart failure, shock, pancreatic hypersecretion, abortion, respiratory arrhytmias and pulmonary edema. As the purification of the venom fractions is a laborious process, one alternative for this would be the utilization of small animals. We utilized in the present study thity-six mice that received progressive doses of scorpion toxin TsTX, i.p. or i.v., and were observed for three hours or sacrificed, and the pulmonary alterations were determined by the lung-body index and by histological analysis of the lungs in order to determine if the mouse can be an esperimental model for scorpion envenomation. The data were analyzed by One Way analysis of variance with pA toxina do escorpião induz a várias alterações fisiológicas, como disturbio do ritmo cardíaco, insuficiência cardíaca, choque, hipersecreção pancreática, aborto, arritmias respiratórias e edema pulmonar. A purificação de frações do veneno é um processo trabalhoso. Como alternativa utilizam-se animais pequenos. No presente estudo utilizou-se 36 camundongos que receberam doses progressivas de toxinas do escorpião (TsTX, intraperitoneal ou intravenosa e foram observados por tres horas ou sacrificados. As alteraçòes pulmonares foram determinadas pela fórmula peso do pulmão x 100/ peso corporal e pela análise hitológica dos pulmões a fim de determinar que o camundongo pode ser um modelo experimental do envenenamento pelo escorpião. Os dados foram analizados pela análise de variância considerando-se p<0,05 indicando significancia. Os experimentos não mostraram diferença nos sinais clínicos do envenenamento comparando-se o camundongo com outros mamíferos. Os efeitos foram dose-dependente e que pela via venosa necessita-se menos quantidade para produzir as mesmas alterações. Nos aspectos histológicos pulmonares observou-se edema septal e não alveolar

  12. Plasma rico em plaquetas de coelhos: introdução a um modelo animal experimental Platelet-rich plasma in rabbits: introduction of one experimental animal model

    Directory of Open Access Journals (Sweden)

    Marco Antonio de Oliveira-Filho

    2008-12-01

    Full Text Available RACIONAL: Muitas dúvidas ainda permanecem no que se refere às ações dos fatores de crescimento e do plasma rico em plaquetas sobre o mecanismo de reparação tissular. Há necessidade de serem esclarecidos pontos controversos ainda existentes. OBJETIVO: Obter o plasma rico em plaquetas em coelhos através de um método simplificado e ao mesmo tempo adequado, introduzindo um modelo experimental que possa ser utilizado em estudos posteriores. MÉTODOS: Foram utilizados 25 coelhas da raça Nova Zelândia e sem doenças prévias. Quinze mL de sangue de cada animal foi coletado, sendo 10 mL submetidos à dupla centrifugação. Para comprovar a efetividade do método proposto realizou-se contagem mecânica do sangue, bem como do produto final. RESULTADO: Obteve-se uma concentração média de plaquetas no plasma rico em plaquetas 687% maior que a contagem inicial observada no sangue venoso periférico. Para as variáveis: contagem inicial de plaquetas, contagem de plaquetas no plasma rico em plaquetas e enriquecimento, foram obtidos os limites de 95% de confiança para suas médias, sendo que, no que se refere ao percentual de enriquecimento, existe 95% de chance de que o intervalo de (530-844 contenha a média real de enriquecimento de plaquetas. CONCLUSÃO: O método simplificado utilizado permite a obtenção de plasma rico em plaquetas adequado permitindo seu uso em estudos dos fatores de crescimento nos mecanismos de reparação tecidual.BACKGROUND: Multiple uncertainties still exist about the action of the growth factors and the platelet-rich plasma on the mechanism of repair. AIM: To obtain the platelet-rich plasma in rabbits through a simplified and suitable method, creating an experimental model. METHODS: Twenty-five female New Zealand rabbits without previous diseases were used. Fifteen mL of blood of each rabbit was collected and 10 mL of the collected blood were twice centrifugated. To check the effectiveness of the proposed method

  13. Validation of the ovine fetus as an experimental model for the human myelomeningocele defect Validação do feto de ovino como modelo experimental de meningomielocele

    Directory of Open Access Journals (Sweden)

    Denise Araújo Lapa Pedreira

    2007-06-01

    Full Text Available PURPOSE: To produce a myelomeningocele-like human defect in the ovine fetus and validate this experimental model in our population. METHODS: A prospective study on 12 pregnant sheep of a crossed Hampshire/Down breed where a spinal defect was surgically created between Day 75 and Day 77 after conception. The technique consisted of a hysterotomy with exposure of fetal hind limbs and tail up to the mid spine. Fetal skin, paravertebral muscles, and 4 posterior spinal arches were excised, exposing the spinal cord. Duramater was opened and the medulla was incised until the medullar canal. Animals were euthanized at 139 days of gestation for fetal evaluation. The central nervous system was submitted to post-mortem magnetic resonance imaging (MRI and the spine was submitted to pathological examination. RESULTS: The defect was created in 13 fetuses and 5 survived. Mean gestational age at necropsy was 121.6 days (varying from 93 to 145 days. Macroscopically, the defect was present in 4 cases. Microscopy revealed a flattened medulla with disappearance of the medullar canal and disruption of normal medullar architecture with neuronal apoptosis and/or fusion of the piamater and duramater. The MRI showed herniation of the cerebellum into the cervical canal and syringomyelia. CONCLUSIONS: The surgically produced defect mimics the defect found in the human fetus, including the Arnold-Chiari malformation. Post-mortem MRI was used for the first time in our study and proved an excellent alternative for demonstrating the cerebellar herniation. We standardized the technique for creating the defect in our population.OBJETIVO: Produzir um defeito semelhante a meningomielocele humana em feto de ovinos, validando este modelo experimental, em nosso meio. MÉTODOS: Estudo prospectivo com 12 ovelhas de cruzamento das raças Hampshire e Down, onde um defeito na coluna foi criado cirurgicamente com 75 a 77 dias de gestação. A técnica consistiu em histerotomia com exposi

  14. Proteção cerebral no tratamento cirúrgico dos aneurismas do arco aórtico: estudo experimental em cães Cerebral protection to be used during aortic arch aneurysms resection

    Directory of Open Access Journals (Sweden)

    Henrique Murad

    1993-09-01

    Full Text Available Os autores realizaram estudo experimental comparativo entre dois métodos de proteção cerebral utilizados na abordagem cirúrgica dos aneurismas do arco aórtico, avaliando a sua eficácia. Os métodos comparados foram a hipotermia sistêmica profunda isolada (menor que 20ºC com pinçamento arterial braquiocefálico e a hipotermia sistêmica profunda associada à perfusão carotídea seletiva. Dois grupos de 15 cães cada foram submetidos, respectivamente, a hipotermia sistêmica profunda com pinçamento arterial braquiocefálico (GRUPO I e a hipotermia sistêmica profunda associada a perfusão seletiva da carótida direita (GRUPO II. Foram colhidas amostras seriadas de sangue para análise das alterações metabólicas de pH e PaCO2 que ocorreram no retorno venoso cerebral, aferidas na veia jugular interna, bem como as alterações histopatológicas encontradas com 45 min, 90 min e 135 min de cada procedimento. Os resultados demonstraram que, apesar de ambos os métodos de proteção cerebral serem eficazes por um período de 45 minutos, o método utilizado no GRUPO II mostrou ser superior em períodos de até 90 minutos. Em períodos de 135 minutos os métodos tiveram resultados semelhantes, não oferecendo proteção cerebral adequada.The authors proposition is to make an experimental study of two methods of cerebral protection to be used during aortic arch aneurysm resection. The methods to be evaluated were profound systemic hypothermia (under 20oC with great vessels occlusion and profound systemic hypothermia with selective right carotid artery perfusion. Two groups of 15 dogs each were submitted either to profound systemic hypothermia with great vessels occlusion (GROUP I or to profound systemic hypothermia with selective right carotid artery perfusion (GROUP II. Serial jugular vein samples for pH and PaC02 were analyzed to evaluate ischemic cerebral metabolic derangements. Hystopathological studies were also made at 45, 90 and 135

  15. Models, simulation, and experimental issues in structural mechanics

    CERN Document Server

    Maceri, Franco; Vairo, Giuseppe

    2017-01-01

    The reader aware in Structural Mechanics will find in this book a source of fruitful knowledge and effective tools useful for imagining, creating, and promoting novel and challenging developments. It addresses a wide range of topics, such as mechanics and geotechnics, vibration and damping, damage and friction, experimental methods, and advanced structural materials. It also discusses analytical, experimental and numerical findings, focusing on theoretical and practical issues, and leading to innovations in the field. Collecting some of the latest results from the Lagrange Laboratory, a European scientific research group, mainly consisting of Italian and French engineers, mechanicians and mathematicians, the book presents the most recent example of the long-term scientific cooperation between well-established French and Italian Mechanics, Mathematics and Engineering Schools. .

  16. Experimental determination and modelling of restricted water effects on bulkcarriers

    OpenAIRE

    Laforce, E.; Vantorre, M.

    2006-01-01

    Systematic captive motion tests on scale models of Panamax bulkcaniers of three different sizes were performed for open shallow water al 10% under keel clearance, in a trapezoidal standard cross section of a canal with 27 % blockage and in a scale model of a canal with varying width. Forces were measured and modelled. A technique of validation of the models by multi-harmonic test runs was developed. The models were used for an evaluation of the influence of ship length by fast-time simulation.

  17. Congenital Transmission of Experimental Leishmaniasis in a Hamster Model

    OpenAIRE

    Osorio, Yaneth; Rodriguez, Luz D.; Diana L Bonilla; Peniche, Alex G.; Henao, Hector; Saldarriaga, Omar; Bruno L. Travi

    2012-01-01

    Little information is available on transplacental transmission of Leishmania spp. We determined the frequency and impact of congenital infection caused by Leishmania panamensis or L. donovani in experimentally infected hamsters. A polymerase chain reaction showed that congenital transmission occurred in 25.8% (24 of 93) of offspring born to L. panamensis-infected hamsters and 14.6% (11 of 75) offspring born to L. donovani-infected hamsters. Mortality during lactation was higher in offspring b...

  18. Model-Based Optimal Experimental Design for Complex Physical Systems

    Science.gov (United States)

    2015-12-03

    optimality aspect of sOED, another major difficulty remains: to numer - ically represent non-Gaussian, continuous random variable posteriors (i.e...construct, as they involve solving a convex optimization problem that can be easily separated into independent sub-problems for each dimension, and requires...OM Knio. “Bayesian Guided Optimal Experimental Design for Reactive Multilayers.” In preparation, 2015. 6. X Huan, “ Numerical Approaches for Sequential

  19. Fantastic animals as an experimental model to teach animal adaptation

    OpenAIRE

    Veronesi Paola; Pini Lorenza; Calzolai Caterina; Baraldi Laura; Guidetti Roberto; Pederzoli Aurora

    2007-01-01

    Abstract Background Science curricula and teachers should emphasize evolution in a manner commensurate with its importance as a unifying concept in science. The concept of adaptation represents a first step to understand the results of natural selection. We settled an experimental project of alternative didactic to improve knowledge of organism adaptation. Students were involved and stimulated in learning processes by creative activities. To set adaptation in a historic frame, fossil records ...

  20. Task-Difficulty Homeostasis in Car Following Models: Experimental Validation Using Self-Paced Visual Occlusion

    National Research Council Canada - National Science Library

    Pekkanen, Jami; Lappi, Otto; Itkonen, Teemu H; Summala, Heikki

    2017-01-01

    ...) model, by dynamically changing driving parameters as function of driver capability. We examined assumptions of these models experimentally using a self-paced visual occlusion paradigm in a simulated car following task...

  1. Products modeling for application in risk analysis, reducing uncertainties; Modelagem de produtos em estudos de risco, reduzindo incertezas

    Energy Technology Data Exchange (ETDEWEB)

    Sodre, Carlos F.; Mendes, Renato F.; Saker, Leonardo F. [PETROBRAS Engenharia, Rio de Janeiro, RJ (Brazil)]. E-mail: felipesodre@petrobras.com.br; renatomendes@petrobras.com.br; Oliveira, Edimilson J.; Aguiar, Paulo Cesar; Pinto, Ulysses Brandao; Badaro, Sonia M. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    Accidental repercussions due to hydrocarbon releases are required on risk analysis studies and contingency plans. The physical effects estimation from releases on vessels or pipelines through out orifices and the estimation of limits for vapor cloud require several modeling, such us: pseudo-mixture estimation, source calculation and dispersion models. These models require physical and chemical properties of the real products in study, so a deep analysis of the original product and the recommended mixtures is demanded. This paper assesses some PETROBRAS refined products and defines pseudo-mixture in order to emulate the physical and chemical properties, for these original products. Finally, it was suggested mixture profiles for some products such as, gasoline, diesel and crude (light), to be applied in next risk studies. (author)

  2. Three-dimensional FEM model of FBGs in PANDA fibers with experimentally determined model parameters

    Science.gov (United States)

    Lindner, Markus; Hopf, Barbara; Koch, Alexander W.; Roths, Johannes

    2017-04-01

    A 3D-FEM model has been developed to improve the understanding of multi-parameter sensing with Bragg gratings in attached or embedded polarization maintaining fibers. The material properties of the fiber, especially Young's modulus and Poisson's ratio of the fiber's stress applying parts, are crucial for accurate simulations, but are usually not provided by the manufacturers. A methodology is presented to determine the unknown parameters by using experimental characterizations of the fiber and iterative FEM simulations. The resulting 3D-Model is capable of describing the change in birefringence of the free fiber when exposed to longitudinal strain. In future studies the 3D-FEM model will be employed to study the interaction of PANDA fibers with the surrounding materials in which they are embedded.

  3. Modeling, signaling and cytoskeleton dynamics: integrated modeling-experimental frameworks in cell migration.

    Science.gov (United States)

    Sun, Meng; Zaman, Muhammad H

    2017-01-01

    Cell migration is a complex and multistep process involved in homeostasis maintenance, morphogenesis, and disease development, such as cancer metastasis. Modeling cell migration and the relevant cytoskeleton dynamics have profound implications for studying fundamental development and disease diagnosis. This review focuses on some recent models of both cell migration and migration-related cytoskeleton dynamics, addressing issues such as the difference between amoeboid and mesenchymal migration modes, and between single-cell migration and collective cell migration. The review also highlights the computational integration among variable external cues, especially the biochemical and mechanical signaling that affects cell migration. Finally, we aim to identify the gaps in our current knowledge and potential strategies to develop integrated modeling-experimental frameworks for multiscale behavior integrating gene expression, cell signaling, mechanics, and multicellular dynamics. WIREs Syst Biol Med 2017, 9:e1365. doi: 10.1002/wsbm.1365 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

  4. Hybrid Electric Vehicle Experimental Model with CAN Network Real Time Control

    Directory of Open Access Journals (Sweden)

    RATOI, M.

    2010-05-01

    Full Text Available In this paper an experimental model with a distributed control system of a hybrid electrical vehicle is presented. A communication CAN network of high speed (1 Mbps assures a distributed control of the all components. The modeling and the control of different operating regimes are realized on an experimental test-bench of a hybrid electrical vehicle. The experimental results concerning the variations of the mains variables (currents, torques, speeds are presented.

  5. Utilização da veia glicerolada na regeneração neural: Estudo experimental em ratos The use of glycerol-treated venous graft in damaged nerves repair: an experimental study in rats

    Directory of Open Access Journals (Sweden)

    Armando dos Santos Cunha

    2007-01-01

    Full Text Available A auto-enxertia de nervo é o tratamento de escolha para grandes perdas de tecido neural que não podem ser reparadas por meio de rafia primária. A utilização do enxerto venoso previamente conservado em glicerol seria uma alternativa para diminuir o tempo operatório e a morbidade cirúrgica nesses casos. Os vasos preservados em glicerol não apresentam destruição de sua estrutura, o que permite seu uso na microcirurgia vascular, tendo a vantagem de diminuir a imunogenicidade do enxerto. O objetivo deste trabalho experimental foi comparar o grau de reparação nervosa, utilizando análise histológica, contagem do número de axônios mielinizados regenerados e análise funcional, obtida com a interposição de enxerto autógeno (grupo A e de tubo de veia glicerolada (grupo B em defeitos de 5 mm no nervo fibular de ratos Wistar. Somente no grupo A foi observado a formação de neuroma. O grupo B apresentou padrões histológicos compatíveis com diminuição quantitativa do número de axônios mielinizados regenerados em menor número em relação ao grupo A (controle. Na recuperação funcional, não houve diferença estatisticamente significativa entre os dois grupos.Autografting is the treatment of choice for cases of major nervous tissue loss where the ruptured nerve ends cannot be reduced. The use of a venous autograft previously treated with glycerol may be an alternative treatment, as it reduces surgery time duration and level of morbidity. Blood vessel explants, used in vascular microsurgery, kept in glycerol maintain their original biological structure, and when used in autografting, present reduced levels of patient's immune response. The aim of this study was to compare the level of nervous tissue regeneration by using histological analysis, regenerated myelinized axons counts, and functional analysis, obtained with the interposition of autologous graft (group A and glycerol-treated vein tube (group B in 5-mm defects on Wistar

  6. Warning system based on theoretical-experimental study of dispersion of soluble pollutants in rivers Sistema de alerta com base em estudo teórico-experimental de dispersão de poluentes solúveis em rios

    Directory of Open Access Journals (Sweden)

    Celso B. de M. Ribeiro

    2011-10-01

    Full Text Available Information about capacity of transport and dispersion of soluble pollutants in natural streams are important in the management of water resources, especially in planning preventive measures to minimize the problems caused by accidental or intentional waste, in public health and economic activities that depend on the use of water. Considering this importance, this study aimed to develop a warning system for rivers, based on experimental techniques using tracers and analytical equations of one-dimensional transport of soluble pollutants conservative, to subsidizing the decision-making in the management of water resources. The system was development in JAVA programming language and MySQL database can predict the travel time of pollutants clouds from a point of eviction and graphically displays the temporal distribution of concentrations of passage clouds, in a particular location, downstream from the point of its launch.Informações sobre a capacidade de transporte e dispersão de poluentes solúveis em cursos de água naturais são importantes no gerenciamento dos recursos hídricos, principalmente no planejamento preventivo de medidas que visem a minimizar problemas à saúde pública e às atividades econômicas que dependem do uso da água, ocasionados por despejos acidentais ou intencionais. Considerando tal importância, este trabalho teve como objetivo desenvolver um sistema de alerta para rios, com base em resultados experimentais, utilizando técnicas de traçadores e equações analíticas de transporte unidimensional de poluentes solúveis conservativos, visando a subsidiar a tomada de decisão no gerenciamento dos recursos hídricos. O sistema desenvolvido em linguagem de programação JAVA e banco de dados MySQL permite prever o tempo de percurso da nuvem de poluentes a partir de um ponto de despejo de um poluente e apresenta, graficamente, a distribuição temporal de concentrações da passagem da nuvem, em um determinado local,

  7. Puerto Rico Experimental Model Dental Auxiliary Training Program. The Comprehensive Report, Exhibits A to F.

    Science.gov (United States)

    Puerto Rico Univ., San Juan. School of Dentistry.

    This annex supplements the Puerto Rico Experimental Model Dental Training Program Comprehensive Report (CE 028 213) and is comprised of exhibits A through F. Among the information included in the exhibits is the experimental model schedule, the schematic representation, the content display, and the course outlines for all courses in the program.…

  8. Theorical and experimental model for carbon-13 turnover in mammalian and avian tissues

    OpenAIRE

    Ducatti Carlos; Carrijo Alfredo Sampaio; Pezzato Antônio Celso; Mancera Paulo Fernando de Arruda

    2002-01-01

    A diferença entre fontes alimentares da ordem de 14‰, originárias de plantas com ciclos fotossintéticos Carbono-3 (C3) e Carbono-4 (C4) e seus subprodutos, abre novas perspectivas para o estudo do metabolismo do carbono em aves e animais de pequeno porte. Os autores propõem um modelo teórico e experimental capaz de exprimir os resultados de enriquecimento relativo, delta per mil (delta‰) da razão 13C/12C versus tempo em diferentes tecidos. Utilizou-se a equação y(t) = (y0 -- q/k) e-kt + q/k o...

  9. Cicatrização de anastomoses do cólon esquerdo com doença inflamatória: estudo experimental em ratos Healing of the left colon anastomosis with inflammatory bowel disease: experimental study in rats

    Directory of Open Access Journals (Sweden)

    Fernando Hintz Greca

    2000-01-01

    Full Text Available Complicações relacionadas com a anastomose são descritas com freqüência nas cirurgias para o tratamento da doença inflamatória do cólon. Para conhecer a interferência da inflamação na cicatrização de anastomoses 40 ratos Wistar são utilizados e divididos em 2 grupos. Um deles serviu de controle e no outro induziu-se doença inflamatória com ácido acético 10% por sondagem retal. No sétimo dia procedeu-se à laparotomia em ambos os grupos, colotomia e anastomose término-terminal com pontos separados em plano único. Avaliadas no terceiro e sétimo dias, pode-se verificar que o número de complicações no grupo de animais com doença inflamatória foi maior assim como a mortalidade. As deiscências com peritonite foi a situação mais comum (p=0,0222. A capacidade de suportar pressão, nas anastomoses que evoluíram sem complicações foi menor nestes cólons, porém a diferença quando comparada ao controle não foi significante (p=0,0836. Verificou-se que as anastomoses construídas em cólons com doença inflamatória apresentavam maior concentração de colágeno total, com predomínio de colágeno imaturo (tipo III (p=0,0000 enquanto que nas feitas em cólons normais predominava colágeno maduro (tipo I (p=0,0102. Observou-se ainda que a organização do colágeno era menor, no terceiro dia, nas anastomoses com doença inflamatória. Entretando a análise da reação inflamatória ao nível da anastomose foi semelhante nos dois grupos. Estes resultados permitem sugerir que a doença inflamatória leva a aumento do número de deiscências provavelmente pelo atraso da maturação e ordenação do colágeno.Complications related to anastomosis failure are frequently described in the surgery of inflammatory bowel disease. The aim of the present study was to evaluated colonic wound healing in an inflamed bowel. Forty Wistar rats were divided in 2 groups: the control and experimental groups. In the experimental group, colitis was

  10. Estudo experimental da aplicação do ventrículo artificial eletromecânico pulsátil implantável Experimental study of pulsatile implantable electromechanical artificial ventricle

    Directory of Open Access Journals (Sweden)

    Jarbas Jakson Dinkhuysen

    2011-03-01

    Full Text Available OBJETIVO: Apresentar os resultados da aplicação deste dispositivo em animais de experimentação, promovendo auxílio hemodinâmico apenas ao ventrículo esquerdo (VE. MÉTODOS: Entre junho 2002 e outubro 2009, foram implantados em 27 bezerros com idade 2½ a 4 meses e peso 80/100 kg e, por meio de anestesia geral e ventilação controlada e de toracotomia lateral esquerda, era introduzida cânula no ápice do VE e anastomose término/lateral de tubo vascular de politetrafluoretileno (PTFE com a porção descendente da aorta torácica, ambos interligados ao dispositivo implantado no subcutâneo abaixo do diafragma (24 e intratorácico (três. Em cinco bezerros, o dispositivo foi aplicado com auxílio de circulação extracorpórea (CEC e, em 22, sem CEC. RESULTADOS: Ocorreram dois óbitos durante o implante e três por causas diversas nas primeiras horas de pós-operatório (PO, sendo um relacionado ao dispositivo. A sobrevivência entre o 1º e 6º dia de PO ocorreu em 17 animais e entre o 8º e 31º dia de PO em cinco, com causas determinantes diversas, não só por problemas clínico/cirúrgicos, mas também relacionados ao dispositivo. O impacto hemodinâmico avaliado pela análise da pressão sistêmica mostrou incremento que variou de 20 a 40 mmHg e os dados laboratoriais analisados demonstraram baixos impactos traumáticos à crase sanguínea e boa biocompatibilidade. CONCLUSÃO: Trata-se de pesquisa árdua e complexa onde a cada experimento são identificados problemas não só de implantabilidade, mas também relacionados ao dispositivo, que vão sendo sistematicamente corrigidos, tornando-o cada vez mais seguro e eficaz.OBJECTIVE: The objective is to present the results of the application this device in experimental animals unloading only the left ventricle. METHODS: Between June 2002 and October 2009, were implanted in 27 calfs with age between 2½ to 4 months and 80 to 100 kg of weight, with general anaesthesia and controled

  11. Evaluation of advanced materials through experimental mechanics and modelling

    Science.gov (United States)

    Yang, Yii-Ching

    1993-01-01

    Composite materials have been frequently used in aerospace vehicles. Very often defects are inherited during the manufacture and damages are inherited during the construction and services. It becomes critical to understand the mechanical behavior of such composite structure before it can be further used. One good example of these composite structures is the cylindrical bottle of solid rocket motor case with accidental impact damages. Since the replacement of this cylindrical bottle is expensive, it is valuable to know how the damages affects the material, and how it can be repaired. To reach this goal, the damage must be characterized and the stress/strain field must be carefully analyzed. First the damage area, due to impact, is surveyed and identified with a shearography technique which uses the principle of speckle shearing interferometry to measure displacement gradient. Within the damage area of a composite laminate, such as the bottle of solid rocket motor case, all layers are considered to be degraded. Once a lamina being degraded the stiffness as well as strength will be drastically decreased. It becomes a critical area of failure to the whole bottle. And hence the stress/strain field within and around a damage should be accurately evaluated for failure prediction. To investigate the stress/strain field around damages a Hybrid-Numerical method which combines experimental measurement and finite element analysis is used. It is known the stress or strain at the singular point can not be accurately measured by an experimental technique. Nevertheless, if the location is far away from the singular spot, the displacement can be found accurately. Since it reflects the true displacement field locally regardless of the boundary conditions, it is an excellent input data for a finite element analysis to replace the usually assumed boundary conditions. Therefore, the Hybrid-Numerical method is chosen to avoid the difficulty and to take advantage of both experimental

  12. Diabetes and hypertension: experimental models for pharmacological studies

    NARCIS (Netherlands)

    van Zwieten, P. A.

    1999-01-01

    Since hypertensive and diabetes-mellitus frequently occur simultaneously there exists a requirement for animal models where both pathological entities are combined. The streptozotocin (STZ)-spontaneously hypertensive rat (STZ-SHR) and the obese Zucker rat are examples of animal models where

  13. Systematic experimental based modeling of a rotary piezoelectric ultrasonic motor

    DEFF Research Database (Denmark)

    Mojallali, Hamed; Amini, Rouzbeh; Izadi-Zamanabadi, Roozbeh

    2007-01-01

    In this paper, a new method for equivalent circuit modeling of a traveling wave ultrasonic motor is presented. The free stator of the motor is modeled by an equivalent circuit containing complex circuit elements. A systematic approach for identifying the elements of the equivalent circuit is sugg...

  14. An Experimental Test of the Contingency Model of Leadership Effectiveness.

    Science.gov (United States)

    Chemers, Martin M.; Skrzypek, George J.

    The present experiment provided a test of Fiedler's (1967) Contingency Model of Leadership Effectiveness, i.e., the relationship of leader style to group effectiveness is mediated by situational demands. Thirty-two 4 man task groups composed of military academy cadets were run in the experiment. In accordance with the Contingency Model, leaders…

  15. Model-robust experimental designs for the fractional polynomial ...

    African Journals Online (AJOL)

    can give a good a fit to the data and much more plausible behavior between de- sign points than the polynomial models. In this ... often resorted to the theory of optimal designs to get practical designs for those models. However the complexity of these nonlinear ..... on Statistics in Industry and Tech- nology, Dayton, Ohio. 18 ...

  16. Systematic integration of experimental data and models in systems biology.

    NARCIS (Netherlands)

    Li, P.; Dada, J.O.; Jameson, D.; Spasic, I.; Swainston, N.; Carroll, K.; Dunn, W.; Khan, F.; Messiha, E.; Simeonides, E.; Weichart, D.; Winder, C.; Broomhead, D.S.; Goble, C.A.; Gaskell, S.J.; Kell, D.B.; Westerhoff, H.V.; Mendes, P.; Paton, N.W.

    2010-01-01

    Background: The behaviour of biological systems can be deduced from their mathematical models. However, multiple sources of data in diverse forms are required in the construction of a model in order to define its components and their biochemical reactions, and corresponding parameters. Automating

  17. Evaluation model and experimental validation of tritium in agricultural plant

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hee Suk; Keum, Dong Kwon; Lee, Han Soo; Jun, In; Choi, Yong Ho; Lee, Chang Woo [KAERI, Daejon (Korea, Republic of)

    2005-12-15

    This paper describes a compartment dynamic model for evaluating the contamination level of tritium in agricultural plants exposed by accidentally released tritium. The present model uses a time dependent growth equation of plant so that it can predict the effect of growth stage of plant during the exposure time. The model including atmosphere, soil and plant compartments is described by a set of nonlinear ordinary differential equations, and is able to predict time-dependent concentrations of tritium in the compartments. To validate the model, a series of exposure experiments of HTO vapor on Chinese cabbage and radish was carried out at the different growth stage of each plant. At the end of exposure, the tissue free water(TFWT) and the organically bound tritium (OBT) were measured. The measured concentrations were agreed well with model predictions.

  18. Estudo da ação da estreptoquinase e do alopurinol em retalhos cutâneos em ilha submetidos à isquemia prolongada: estudo experimental em ratos Study of the effect of streptokinase and allopurinol in island skin flaps submitted to prolonged ischemia: experimental study in rats

    Directory of Open Access Journals (Sweden)

    Tatiana de Moura

    2009-01-01

    Full Text Available OBJETIVO: Estabelecer relação entre a sobrevivência de retalhos cutâneos em ilha submetidos à isquemia prolongada e o uso da estreptoquinase e do alopurinol administrados após o período de isquemia prolongado. MÉTODOS: Foram utilizados 48 ratos machos da raça Wistar, com peso entre 300 e 350g, divididos em quatro grupos com 12 cada um, sendo; grupo controle, alopurinol, estreptoquinase e associação de alopurinol com estreptoquinase, submetidos à dissecção de retalho epigástrico em ilha, seguido de clampeamento do feixe vascular, por oito horas em isquemia mista normotérmica. Após este período, as pinças foram retiradas e cada animal recebeu o esquema terapêutico proposto através de injeção intravenosa. A análise da sobrevivência dos retalhos foi realizada no sétimo dia de pós-operatório. Foram realizadas análises descritivas (% de área necrótica e de variâncias, bem como comparações múltiplas de Dunnett T3 entre os quatro grupos e o teste da mediana. RESULTADOS: O grupo controle apresentou em média 79,88% de necrose da área total. Aqueles que receberam alopurinol apresentaram em média 64,05% de necrose e o grupo que recebeu estreptoquinase apresentou em média 55,52% de necrose. Com a associação das duas drogas, os ratos apresentaram 54,30% em média de necrose do retalho. Aplicando o teste Dunnett e o teste da mediana verificou-se de que o grupo estreptoquinase é o com menor percentual de necrose neste estudo. CONCLUSÃO: A administração sistêmica da estreptoquinase após oito horas de isquemia mista normotérmica resultou em aumento da sobrevivência de retalhos epigástricos em ilha em ratos, quando comparada à administração de alopurinol, associação do alopurinol e estreptoquinase e do grupo controle.BACKGROUND: To establish a relation between the survival rate of island skin flaps submitted to prolonged ischemia and the effect of streptokinase and allopurinol administered after the ischemic

  19. Flow of a blood analogue fluid in a compliant abdominal aortic aneurysm model: experimental modelling.

    Science.gov (United States)

    Deplano, Valérie; Knapp, Yannick; Bailly, Lucie; Bertrand, Eric

    2014-04-11

    The aim of this work is to develop a unique in vitro set-up in order to analyse the influence of the shear thinning fluid-properties on the flow dynamics within the bulge of an abdominal aortic aneurysm (AAA). From an experimental point of view, the goals are to elaborate an analogue shear thinning fluid mimicking the macroscopic blood behaviour, to characterise its rheology at low shear rates and to propose an experimental device able to manage such an analogue fluid without altering its feature while reproducing physiological flow rate and pressure, through compliant AAA. Once these experimental prerequisites achieved, the results obtained in the present work show that the flow dynamics is highly dependent on the fluid rheology. The main results point out that the propagation of the vortex ring, generated in the AAA bulge, is slower for shear thinning fluids inducing a smaller travelled distance by the vortex ring so that it never impacts the anterior wall in the distal region, in opposition to Newtonian fluids. Moreover, scalar shear rate values are globally lower for shear thinning fluids inducing higher maximum stress values than those for the Newtonian fluids. Consequently, this work highlights that a Newtonian fluid model is finally inadequate to obtain a reliable prediction of the flow dynamics within AAA. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Experimental and theoretical study of magnetohydrodynamic ship models.

    Directory of Open Access Journals (Sweden)

    David Cébron

    Full Text Available Magnetohydrodynamic (MHD ships represent a clear demonstration of the Lorentz force in fluids, which explains the number of students practicals or exercises described on the web. However, the related literature is rather specific and no complete comparison between theory and typical small scale experiments is currently available. This work provides, in a self-consistent framework, a detailed presentation of the relevant theoretical equations for small MHD ships and experimental measurements for future benchmarks. Theoretical results of the literature are adapted to these simple battery/magnets powered ships moving on salt water. Comparison between theory and experiments are performed to validate each theoretical step such as the Tafel and the Kohlrausch laws, or the predicted ship speed. A successful agreement is obtained without any adjustable parameter. Finally, based on these results, an optimal design is then deduced from the theory. Therefore this work provides a solid theoretical and experimental ground for small scale MHD ships, by presenting in detail several approximations and how they affect the boat efficiency. Moreover, the theory is general enough to be adapted to other contexts, such as large scale ships or industrial flow measurement techniques.

  1. Experimental and theoretical study of magnetohydrodynamic ship models.

    Science.gov (United States)

    Cébron, David; Viroulet, Sylvain; Vidal, Jérémie; Masson, Jean-Paul; Viroulet, Philippe

    2017-01-01

    Magnetohydrodynamic (MHD) ships represent a clear demonstration of the Lorentz force in fluids, which explains the number of students practicals or exercises described on the web. However, the related literature is rather specific and no complete comparison between theory and typical small scale experiments is currently available. This work provides, in a self-consistent framework, a detailed presentation of the relevant theoretical equations for small MHD ships and experimental measurements for future benchmarks. Theoretical results of the literature are adapted to these simple battery/magnets powered ships moving on salt water. Comparison between theory and experiments are performed to validate each theoretical step such as the Tafel and the Kohlrausch laws, or the predicted ship speed. A successful agreement is obtained without any adjustable parameter. Finally, based on these results, an optimal design is then deduced from the theory. Therefore this work provides a solid theoretical and experimental ground for small scale MHD ships, by presenting in detail several approximations and how they affect the boat efficiency. Moreover, the theory is general enough to be adapted to other contexts, such as large scale ships or industrial flow measurement techniques.

  2. Fantastic animals as an experimental model to teach animal adaptation.

    Science.gov (United States)

    Guidetti, Roberto; Baraldi, Laura; Calzolai, Caterina; Pini, Lorenza; Veronesi, Paola; Pederzoli, Aurora

    2007-08-16

    Science curricula and teachers should emphasize evolution in a manner commensurate with its importance as a unifying concept in science. The concept of adaptation represents a first step to understand the results of natural selection. We settled an experimental project of alternative didactic to improve knowledge of organism adaptation. Students were involved and stimulated in learning processes by creative activities. To set adaptation in a historic frame, fossil records as evidence of past life and evolution were considered. The experimental project is schematized in nine phases: review of previous knowledge; lesson on fossils; lesson on fantastic animals; planning an imaginary world; creation of an imaginary animal; revision of the imaginary animals; adaptations of real animals; adaptations of fossil animals; and public exposition. A rubric to evaluate the student's performances is reported. The project involved professors and students of the University of Modena and Reggio Emilia and of the "G. Marconi" Secondary School of First Degree (Modena, Italy). The educational objectives of the project are in line with the National Indications of the Italian Ministry of Public Instruction: knowledge of the characteristics of living beings, the meanings of the term "adaptation", the meaning of fossils, the definition of ecosystem, and the particularity of the different biomes. At the end of the project, students will be able to grasp particular adaptations of real organisms and to deduce information about the environment in which the organism evolved. This project allows students to review previous knowledge and to form their personalities.

  3. Fantastic animals as an experimental model to teach animal adaptation

    Directory of Open Access Journals (Sweden)

    Veronesi Paola

    2007-08-01

    Full Text Available Abstract Background Science curricula and teachers should emphasize evolution in a manner commensurate with its importance as a unifying concept in science. The concept of adaptation represents a first step to understand the results of natural selection. We settled an experimental project of alternative didactic to improve knowledge of organism adaptation. Students were involved and stimulated in learning processes by creative activities. To set adaptation in a historic frame, fossil records as evidence of past life and evolution were considered. Results The experimental project is schematized in nine phases: review of previous knowledge; lesson on fossils; lesson on fantastic animals; planning an imaginary world; creation of an imaginary animal; revision of the imaginary animals; adaptations of real animals; adaptations of fossil animals; and public exposition. A rubric to evaluate the student's performances is reported. The project involved professors and students of the University of Modena and Reggio Emilia and of the "G. Marconi" Secondary School of First Degree (Modena, Italy. Conclusion The educational objectives of the project are in line with the National Indications of the Italian Ministry of Public Instruction: knowledge of the characteristics of living beings, the meanings of the term "adaptation", the meaning of fossils, the definition of ecosystem, and the particularity of the different biomes. At the end of the project, students will be able to grasp particular adaptations of real organisms and to deduce information about the environment in which the organism evolved. This project allows students to review previous knowledge and to form their personalities.

  4. Recent advances in animal model experimentation in autism research.

    Science.gov (United States)

    Tania, Mousumi; Khan, Md Asaduzzaman; Xia, Kun

    2014-10-01

    Autism, a lifelong neuro-developmental disorder is a uniquely human condition. Animal models are not the perfect tools for the full understanding of human development and behavior, but they can be an important place to start. This review focused on the recent updates of animal model research in autism. We have reviewed the publications over the last three decades, which are related to animal model study in autism. Animal models are important because they allow researchers to study the underlying neurobiology in a way that is not possible in humans. Improving the availability of better animal models will help the field to increase the development of medicines that can relieve disabling symptoms. Results from the therapeutic approaches are encouraging remarkably, since some behavioral alterations could be reversed even when treatment was performed on adult mice. Finding an animal model system with similar behavioral tendencies as humans is thus vital for understanding the brain mechanisms, supporting social motivation and attention, and the manner in which these mechanisms break down in autism. The ongoing studies should therefore increase the understanding of the biological alterations associated with autism as well as the development of knowledge-based treatments therapy for those struggling with autism. In this review, we have presented recent advances in research based on animal models of autism, raising hope for understanding the disease biology for potential therapeutic intervention to improve the quality of life of autism individuals.

  5. Gas Absorption by Alkaline Solution in a Cyclone Scrubber: Experimental and Modeling Study

    Directory of Open Access Journals (Sweden)

    Mariana Mariana

    2009-06-01

    Full Text Available Experimental and modeling studies have been conducted on a CO2 absorption in a cyclone scrubber operated at room temperature. The effects of parameters such as the initial concentration of alkali in the solution and the liquid – gas ratio on the CO2 absorbed flux were experimentally and theoretically investigated. A theoretical study has been performed using a mathematical model based on the absorption in the liquid droplet with instantaneous reaction, in the inlet duct of the cyclone and in the cyclone itself. The results from the model were compared with experimental data and showed satisfactory agreement.   Keywords: CO2 removal, mathematical model, wet cyclone scrubber

  6. Estudo teórico-experimental do transitório da corrente de dreno e do tempo de vida de geração em tecnologias SOI MOSFETs.

    OpenAIRE

    Milene Galeti

    2008-01-01

    Este trabalho apresenta um estudo sobre o transitório da corrente de dreno e métodos de extração de tempo de vida de geração em transistores SOI MOSFETs parcialmente depletados de porta simples, porta dupla e FinFETs de porta tripla. Este estudo foi baseado tanto em simulações numéricas bidimensionais como em dados experimentais extraídos a partir de transistores fabricados no IMEC (Interuniversity Microelectronics Center), que fica na Universidade Católica de Leuven (KUL) na Bélgica. Inicial...

  7. Estudo hidrológico da bacia hidrográfica do Rio Jundiaí-RN visando a implantação de bacia experimental e a atenuação de cheias pela barragem Tabatinga

    OpenAIRE

    Troncoso, Raquel Ferreira

    2012-01-01

    A gestão de recursos hídricos em nível da bacia hidrográfica, como define a Lei nº 9433/97, exige o conhecimento efetivo dos processos hidrológicos da bacia, decorrentes de estudos baseados em séries consistentes de dados hidrológicos que espelhem as características da bacia. Neste contexto, este trabalho teve como objetivo desenvolver a modelagem hidrológica da bacia hidrográfica do rio Jundiaí RN e realizar o estudo da atenuação de cheia da barragem Tabatinga visando a i...

  8. Tesla Coil Theoretical Model and its Experimental Verification

    National Research Council Canada - National Science Library

    Janis Voitkans; Arnis Voitkans

    2014-01-01

    In this paper a theoretical model of Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wire form, where the line voltage is measured across electrically neutral space...

  9. New experimental models of skin homeostasis and diseases.

    Science.gov (United States)

    Larcher, F; Espada, J; Díaz-Ley, B; Jaén, P; Juarranz, A; Quintanilla, M

    2015-01-01

    Homeostasis, whose regulation at the molecular level is still poorly understood, is intimately related to the functions of epidermal stem cells. Five research groups have been brought together to work on new in vitro and in vivo skin models through the SkinModel-CM program, under the auspices of the Spanish Autonomous Community of Madrid. This project aims to analyze the functions of DNA methyltransferase 1, endoglin, and podoplanin in epidermal stem cell activity, homeostasis, and skin cancer. These new models include 3-dimensional organotypic cultures, immunodeficient skin-humanized mice, and genetically modified mice. Another aim of the program is to use skin-humanized mice to model dermatoses such as Gorlin syndrome and xeroderma pigmentosum in order to optimize new protocols for photodynamic therapy. Copyright © 2013 Elsevier España, S.L.U. and AEDV. All rights reserved.

  10. Experimental analysis and modeling of a stormwater perlite filter.

    Science.gov (United States)

    Gironás, Jorge; Adriasola, José M; Fernández, Bonifacio

    2008-06-01

    This paper presents the study of a mixed porous media composed of expanded perlite and a nonwoven needle-punched geotextile used to reduce the suspended solids load and concentration in urban runoff. Laboratory procedures were designed to quantify the suspended solids removal efficiency and variation in time of filtration rate. Different grain-size distributions of expanded perlite, diverse suspended solids concentrations, and different hydraulic and geometric conditions were tested to determine the most effective filter media. A dimensionless parameter, termed Global Performance Index (GPI), was developed to reach this objective. Measured data were also used to build a dimensional and a regression model to represent the performance of the filter media mathematically. The theory, derivation, and performance of both models are presented and compared with an existent empirical model. The dimensional model better reproduces the observations, becoming a useful tool for the design, operation, and evaluation of commercial porous media filters.

  11. EXPERIMENTAL MODELS FOR THE STUDY OF ORAL CLEFTS

    Science.gov (United States)

    Toxicology and teratology studies routinely utilize animal models to determine the potential for chemical and physical agents to produce reproductive and developmental toxicity, including birth defects such as cleft palate. The standardized teratology screen typically tests co...

  12. An Experimental Animal Model for Abdominal Fascia Healing after Surgery

    DEFF Research Database (Denmark)

    Burcharth, J; Pommergaard, H-C; Klein, M

    2013-01-01

    Background: Incisional hernia (IH) is a well-known complication after abdominal surgical procedures. The exact etiology of IH is still unknown even though many risk factors have been suggested. The aim of this study was to create an animal model of a weakly healed abdominal fascia that could...... be used to evaluate the actively healing fascia. Such an animal model may promote future research in the prevention of IH. Methods: 86 male Sprague-Dawley rats were used to establish a model involving six experiments (experiments A-F). Mechanical testing of the breaking strength of the healed fascia...... was performed by testing tissue strips from the healed fascia versus the unincised control fascia 7 and 28 days postoperatively. Results: During the six experiments a healing model was created that produced significantly weaker coherent fascia when compared with the control tissue measured in terms...

  13. Estereótipos, mentiras e videotape: estudos experimentais sobre a acurácia na identificação da mentira Stereotypes, lies and videotape: experimental studies on the degree of accuracy in identifying a lie

    Directory of Open Access Journals (Sweden)

    Marcos Emanoel Pereira

    2006-04-01

    Full Text Available O objetivo deste estudo foi investigar a acurácia da avaliação da mentira e, em seguida, a forma pela qual a vinculação a determinadas categorias sociais interfere e modifica a percepção e o julgamento social. Assumiram-se aqui três hipóteses de trabalho. A primeira delas refere-se ao tipo de pista que favorece a identificação da mentira. A segunda refere-se ao grau de acurácia na identificação dos erros entre as categorias sociais. A terceira se refere aos efeitos exercidos pelos estereótipos. O teste empírico da primeira hipótese não apontou diferenças na identificação da mentira quando utilizadas somente pistas visuais ou auditivas e visuais. No teste da segunda hipótese constatou-se a pouca significância apresentada pela categoria social representada na cena. O teste da terceira revelou que as crenças estereotipadas não foram suficientemente fortes para distorcer os julgamentos e influenciar os tipos de erros esperados.The aim of this study is to experimentally investigate the lying behavior. Three hypotheses have been advocated. The first concerns the kind of cues which are conducive to identifying a lie (auditory and/or visual. The second is about the degree of accuracy in identifying mistakes among social categories. Lastly, the third relates to stereotypes effects and proposes a different pattern structure with regard to mistakes made by participants about lies presented by individuals from the social groups under investigation. The first assumption did not lead to any differences in lie identifying when the clues are either visual and auditory or visual only. It has been found that the social category depicted in the scene holds little significance. The third group of assumptions, on its turn, made it clear that stereotyped beliefs were not strong enough to distort judgment and thus influence the mistakes.

  14. An improved experimental model for peripheral neuropathy in rats

    Directory of Open Access Journals (Sweden)

    Q.M. Dias

    Full Text Available A modification of the Bennett and Xie chronic constriction injury model of peripheral painful neuropathy was developed in rats. Under tribromoethanol anesthesia, a single ligature with 100% cotton glace thread was placed around the right sciatic nerve proximal to its trifurcation. The change in the hind paw reflex threshold after mechanical stimulation observed with this modified model was compared to the change in threshold observed in rats subjected to the Bennett and Xie or the Kim and Chung spinal ligation models. The mechanical threshold was measured with an automated electronic von Frey apparatus 0, 2, 7, and 14 days after surgery, and this threshold was compared to that measured in sham rats. All injury models produced significant hyperalgesia in the operated hind limb. The modified model produced mean ± SD thresholds in g (19.98 ± 3.08, 14.98 ± 1.86, and 13.80 ± 1.00 at 2, 7, and 14 days after surgery, respectively similar to those obtained with the spinal ligation model (20.03 ± 1.99, 13.46 ± 2.55, and 12.46 ± 2.38 at 2, 7, and 14 days after surgery, respectively, but less variable when compared to the Bennett and Xie model (21.20 ± 8.06, 18.61 ± 7.69, and 18.76 ± 6.46 at 2, 7, and 14 days after surgery, respectively. The modified method required less surgical skill than the spinal nerve ligation model.

  15. Europium anomaly in plagioclase feldspar - Experimental results and semiquantitative model.

    Science.gov (United States)

    Weill, D. F.; Drake, M. J.

    1973-01-01

    The partition of europium between plagioclase feldspar and magmatic liquid is considered in terms of the distribution coefficients for divalent and trivalent europium. A model equation is derived giving the europium anomaly in plagioclase as a function of temperature and oxygen fugacity. The model explains europium anomalies in plagioclase synthesized under controlled laboratory conditions as well as the variations of the anomaly observed in natural terrestrial and extraterrestrial igneous rocks.

  16. An improved experimental model for peripheral neuropathy in rats

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Q.M.; Rossaneis, A.C.; Fais, R.S.; Prado, W.A. [Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2013-03-15

    A modification of the Bennett and Xie chronic constriction injury model of peripheral painful neuropathy was developed in rats. Under tribromoethanol anesthesia, a single ligature with 100% cotton glace thread was placed around the right sciatic nerve proximal to its trifurcation. The change in the hind paw reflex threshold after mechanical stimulation observed with this modified model was compared to the change in threshold observed in rats subjected to the Bennett and Xie or the Kim and Chung spinal ligation models. The mechanical threshold was measured with an automated electronic von Frey apparatus 0, 2, 7, and 14 days after surgery, and this threshold was compared to that measured in sham rats. All injury models produced significant hyperalgesia in the operated hind limb. The modified model produced mean ± SD thresholds in g (19.98 ± 3.08, 14.98 ± 1.86, and 13.80 ± 1.00 at 2, 7, and 14 days after surgery, respectively) similar to those obtained with the spinal ligation model (20.03 ± 1.99, 13.46 ± 2.55, and 12.46 ± 2.38 at 2, 7, and 14 days after surgery, respectively), but less variable when compared to the Bennett and Xie model (21.20 ± 8.06, 18.61 ± 7.69, and 18.76 ± 6.46 at 2, 7, and 14 days after surgery, respectively). The modified method required less surgical skill than the spinal nerve ligation model.

  17. Correlação entre a tração de afastadores e o risco de isquemia e infecção de feridas cirúrgicas: estudo experimental em ratos Correlation between surgical retractors and risk of wound ischemia and infection: experimental study in rats

    Directory of Open Access Journals (Sweden)

    Fernando Hintz Greca

    1997-03-01

    Full Text Available Verificou-se o grau de isquemia produzido pela tração dos afastadores, bem como determinou-se o índice de infecção nas feridas limpas e contaminadas quando submetidas a trações conhecidas e progressivas. Foram utilizados 104 ratos machos da cepa Wistar com peso entre 180 e 190 gr, sendo que 40 animais foram utilizados para a determinação da isquemia provocada por afastadores e 64 para estudo da correlação do emprego de afastadores com infecção. Para a análise da isquemia produzida por afastadores sobre a ferida cirúrgica, os 40 ratos foram divididos em 4 grupos: T0, T1, T2, T3. Para o estudo do risco de infecção produzido por afastadores sobre a ferida cirúrgica, 64 ratos foram divididos em oito grupos: C0, C1, C2, C3, L0, L1, L2 e L3. Todos animais foram submetidos a laparotomia paramediana, conservando-se íntegro o peritônio. A ferida foi então submetida a tração por afastadores. A tração empregada foi de 0Kgf nos grupos T0, L0, C0; 0,062Kgf nos grupos T1, L1 e C1; 0,125Kgf nos grupos T2, L2 e C2 e 0,25Kgf nos grupos T3, L3 e C3. Nos grupos T0, Tl, T2 e T3 injetou-se o corante azul de Evans e após 1 hora foram retirados fragmentos da ferida, com posterior extração do corante e análise espectrofotocolorimétrica, que serviu para avaliar indiretamente o grau de isquemia da ferida. Nos grupos CO, Cl, C2 eC3 foi inoculado na ferida uma solução contendo 10(5 Stafilococcus aureus l ml. As feridas nos grupos C0, C1, C2, C3, L0, L1, L2 e L3 foram suturadas e os animais sacrificados após sete dias para análise bacteriológica das amostras. Verificou-se que nos grupos T1, T2, T3 o grau de isquemia aumentou a medida que se usava maior tração, fato este comprovado pela diminuição progressiva da concentração tissular do corante azul de Evans (pThe relation between ischemia and infection is well known, but the hazards of surgical retractors to wound healing is not well documented. We developed a experimental model to

  18. Modeling experimental plasma diagnostics in the FLASH code: Thomson scattering

    Science.gov (United States)

    Weide, Klaus; Flocke, Norbert; Feister, Scott; Tzeferacos, Petros; Lamb, Donald

    2017-10-01

    Spectral analysis of the Thomson scattering of laser light sent into a plasma provides an experimental method to quantify plasma properties in laser-driven plasma experiments. We have implemented such a synthetic Thomson scattering diagnostic unit in the FLASH code, to emulate the probe-laser propagation, scattering and spectral detection. User-defined laser rays propagate into the FLASH simulation region and experience scattering (change in direction and frequency) based on plasma parameters. After scattering, the rays propagate out of the interaction region and are spectrally characterized. The diagnostic unit can be used either during a physics simulation or in post-processing of simulation results. FLASH is publicly available at flash.uchicago.edu. U.S. DOE NNSA, U.S. DOE NNSA ASC, U.S. DOE Office of Science and NSF.

  19. Experimental Investigation and Modeling of Integrated Tri-generation Systems

    Science.gov (United States)

    Cetinkaya, Eda

    Energy demand in the world is increasing with population growth and higher living standards. Today, the need for energy requires a focus on renewable sources without abandoning fossil fuels. Efficient use of energy is one of the most important tasks in modern energy systems to achieve. In addition to the energy need, growing environmental concerns are linked with energy is emerged. Multi-purpose energy generation allows a higher efficiency by generating more outputs with the same input in the same system. Tri-generation systems are expected to provide at least three commodities, such as heating, cooling, desalination, storable fuel production and some other useful outputs, in addition to power generation. In this study, an experimental investigation of gasification is presented and two integrated tri-generation systems are proposed. The first integrated tri-generation system (System 1) utilizes solar energy as input and the outputs are power, fresh water and hot water. It consists of four sub-systems, namely solar power tower system, desalination system, Rankine cycle and organic Rankine cycle (ORC). The second integrated tri-generation system (System 2) utilizes coal and biomass as input and the outputs are power, fuel and hot water. It consists of five sub-systems: gasification plant, Brayton cycle, Rankine cycle, Fischer-Tropsch synthesis plant and an organic Rankine cycle (ORC). Experimental investigation includes coal and biomass gasification, where the experimental results of synthesis gas compositions are utilized in the analysis of the second systems. To maximize efficiency, heat losses from the system should be minimized through a recovery system to make the heat a useful commodity for other systems, such as ORCs which can utilize the low-grade heat. In this respect, ORCs are first analyzed for three different configurations in terms of energy and exergy efficiencies altering working fluids to increase the power output. Among two types of coal and one type

  20. An engineering approach to business model experimentation – an online investment research startup case study

    NARCIS (Netherlands)

    Kijl, Björn; Boersma, Durk

    2010-01-01

    Every organization needs a viable business model. Strikingly, most of current literature is focused on business model design, whereas there is almost no attention for business model validation and implementation and related business model experimentation. The goal of the research as described in

  1. Error Modelling and Experimental Validation for a Planar 3-PPR Parallel Manipulator

    DEFF Research Database (Denmark)

    Wu, Guanglei; Bai, Shaoping; Kepler, Jørgen Asbøl

    2011-01-01

    In this paper, the positioning error of a 3-PPR planar parallel manipulator is studied with an error model and experimental validation. First, the displacement and workspace are analyzed. An error model considering both configuration errors and joint clearance errors is established. Using...... this model, the maximum positioning error was estimated for a U-shape PPR planar manipulator, the results being compared with the experimental measurements. It is found that the error distributions from the simulation is approximate to that of themeasurements....

  2. An Experimental Protocol to Model Recovery of Anaerobic Work Capacity

    Directory of Open Access Journals (Sweden)

    Vijay Sarthy M. Sreedhara

    2018-02-01

    Full Text Available Models of fatigue are based on physiological parameters such as Critical Power (CP and Anaerobic Work Capacity (AWC. CP is a theoretical threshold value that a human can generate for an indefinite amount of time and AWC represents a finite expendable amount of anaerobic energy at intensities above CP. There is an increasing interest in developing mathematical models of energy expenditure and recovery for athletic training and human performance. The objective of this research is to propose and validate a model for recovery of AWC during a post exertion recovery interval of cycling. A cycling ergometer study is proposed which involves a VO2max ramp test to determine gas exchange threshold, a 3-min all-out intensity test to determine CP and AWC, and exertion-recovery interval tests to understand recovery of AWC. The results will be used to build a human in the loop control system to optimize cycling performance.

  3. An experimental study of tether reel system: A laboratory model

    OpenAIRE

    Yoshimura, Shoichi; Okamoto, Osamu; 吉村 庄市; 岡本 修

    1992-01-01

    A laboratory prototype model of a reel system has been made as the first step of an in-house hardware study of the tether system in space. The model is consisted of two main parts, i. e., a Reel Drum Driving (RDD) unit (25 kg weight) and a Power Supply/Signal Processing (PSSP) unit (32 kg weight). The tether (0.8 mm in diameter and 300 m long) consists of a Kevlar fiber core and a nylon fiber jacket. Following the preliminary functional test, a computer-controlled functional test has been car...

  4. Cuttings Transport Models and Experimental Visualization of Underbalanced Horizontal Drilling

    Directory of Open Access Journals (Sweden)

    Na Wei

    2013-01-01

    Full Text Available Aerated underbalanced horizontal drilling technology has become the focus of the drilling industry at home and abroad, and one of the engineering core issues is the horizontal borehole cleaning. Therefore, calculating the minimum injection volume of gas and liquid accurately is essential for the construction in aerated underbalanced horizontal drilling. This paper establishes a physical model of carrying cuttings and borehole cleaning in wellbore of horizontal well and a critical transport mathematical model according to gas-liquid-solid flow mechanism and large plane dunes particle transport theory.

  5. Cicatrização da membrana timpânica na timpanocentese com laser de argônio comparado à técnica com microlanceta: estudo experimental em ratos Tympanic membrane healing in myringotomies performed with argon laser or microknife: an experimental study in rats

    Directory of Open Access Journals (Sweden)

    Lucio Almeida Castagno

    2006-12-01

    Full Text Available Otite média secretora (OMS e otite média aguda recorrente (OMAR podem necessitar tratamento cirúrgico para adequada ventilação da orelha média. A abertura clássica do tímpano (timpanocentese requer incisão por microlanceta sob controle de microscópio cirúrgico e mantém-se patente por alguns dias. Estudos recentes sugerem que a timpanocentese feita por diferentes lasers pode permanecer permeável por maior tempo, o que possibilitaria a normalização da otite média. MATERIAL E MÉTODOS: Neste estudo experimental 34 ratos linhagem Wistar, albinos, machos adultos pesando cerca de 300g, foram anestesiados com cetamina 27 mg/kg e xilazina 2,7 mg/kg. A seguir, foram submetidos à timpanocentese incisional com microlanceta no ouvido direito (ML-OD, e à timpanocentese mediada por laser de argônio no ouvido esquerdo (LA-OE. RESULTADOS: Não houve diferença significativa no tempo de cicatrização das timpanocenteses feitas com laser de argônio ou microlanceta. Todas as timpanocenteses cicatrizaram em 10 dias. CONCLUSÃO: A timpanocentese com laser de argônio apresentou patência e cicatrização semelhantes à técnica clássica com microlanceta realizada em ratos Wistar sem enfermidades de orelha média.Secretory otitis media (SOM and recurrent acute otitis media (RAOM may require surgical treatment to proper ventilate the middle ear. Incisional myringotomy is usually done under microscopy with a micro-knife , but it remains patent for just a few days. Recent research indicates that laser assisted myringotomies remain open much longer, allowing middle ear ventilation and healing. MATERIAL AND METHODS: In this experimental study 34 white, male, adult, Wistar rats, without middle ear disease were submited to anesthesia with ketamine 27 mg/kg and xylazine 2,7 mg/kg. Incisional myringotomy was done on the right ear, while laser myringotomy was done on the left. Myringotomies were evaluated periodically until healing. RESULTS: The healing

  6. Estudo experimental da aplicação das forças de compressão ou distração sobre o sistema de fixação pedicular Compression or distraction forces applied on a pedicular fixation system: an experimental study

    Directory of Open Access Journals (Sweden)

    Helton Luiz Aparecido Defino

    2006-01-01

    Full Text Available Foi realizado estudo experimental com o objetivo de avaliar os efeitos da aplicação da força de compressão e distração (aproximação e afastamento sobre os implantes colocados nos pedículos vertebrais. Foram utilizados no estudo os segmentos vertebrais T8-T9, T10-T11, T12-L1, L2-L3 e L4-L5 de suínos da raça Landsark. Cada segmento vertebral foi fixado com implantes pediculares, tendo sido aplicada força de compressão ou distração com deslocamento que variou de 5,1 mm a 9,35 mm. O deslocamento provocado pela aplicação das forças foi mensurado em quatro pontos do segmento vertebral: A (porção anterior do corpo vertebral, B (porção média do corpo vertebral, C (porção posterior do corpo vertebral e D (processo articular siperior. A força de compressão produziu o afastamento dos pontos localizados nas regiões A e B, e aproximação dos pontos da região D. A força de distração produziu a aproximação dos pontos da região A e B e o afastamento dos pontos da região D.An experimental study was conducted with the objective of evaluating the effects of compression and distraction (approach and deviation forces applied on implants placed at vertebral pedicles. The vertebral segments T8-T9, T10-T11, T12-L1, L2-L3 and L4-L5 of Landsark pigs were used in the study. Each vertebral segment was fixed with pedicular implants, with compression or distraction forces being applied with a displacement that ranged from 5.1 mm to 9.35 mm. Displacement caused by forces application was measured in four points of the vertebral segment: A (anterior portion of the vertebral segment, B (medial portion of the vertebral segment, C (posterior portion of the vertebral segment and D (superior joint process. Compression forces caused the deviation of points located at regions A and B, and the approach of points at region D. Distraction forces caused the approach of points at regions A and B and deviation of the points at region D.

  7. Experimental and numerical modeling of shrub crown fire initiation

    Science.gov (United States)

    Watcharapong Tachajapong; Jesse Lozano; Shakar Mahalingam; Xiangyang Zhou; David Weise

    2009-01-01

    The transition of fire from dry surface fuels to wet shrub crown fuels was studied using laboratory experiments and a simple physical model to gain a better understanding of the transition process. In the experiments, we investigated the effects of varying vertical distances between surface and crown fuels (crown base height), and of the wind speed on crown fire...

  8. Mathematical Modelling and Experimental Analysis of Early Age Concrete

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Anders Boe

    1997-01-01

    The report deals with mathematical models for concrete at early age. In the hardening process chemical reactions take place and the concrete skeleton is created. The processes changes the moisture content and produces heat. The associated temperature rise gives expansion of the material which may...... element concept....

  9. Experimental Validation of Flow Force Models for Fast Switching Valves

    DEFF Research Database (Denmark)

    Bender, Niels Christian; Pedersen, Henrik Clemmensen; Nørgård, Christian

    2017-01-01

    to compare and validate different models, where an effort is directed towards capturing the fluid squeeze effect just before material on material contact. The test data is compared with simulation data relying solely on analytic formulations. The general dynamics of the plunger is validated...

  10. Experimentally validated thermal model of thin film NiTi

    Science.gov (United States)

    Favelukis, Jenna E.; Lavine, Adrienne S.; Carman, Gregory P.

    1999-06-01

    The primary focus of this work is to develop a new analytical approach for thermal modeling of Nickel Titanium (NiTi) shape memory alloy membranes undergoing both phase transformation and large deflections. This paper describes a thermal model of a NiTi plate or thin film, including all the modes of heat loss and latent heat dissipation during the phase transformation. This model is used to predict the NiTi temperature during cooling. The results are compared with experiments conducted on a NiTi plate and thin film (3 micrometers thick), and very good agreement is found. The thermal model is also used to predict the temperature response of a bubble actuator proposed for use in a forced flow environment. Using a 3 mm diameter, 3 micrometers thickness bubble under forced airflow conditions it is possible to achieve a frequency response faster than 300 Hz. Additional calculations were made to verify the structural stability of the actuator system. Predictions indicated that for specific geometries a pressure of at least 35 kPa can be supported by the NiTi membrane. Deflections of a bubble actuator are shown to be on the order of 10% of its diameter while the strain remains below 4%.

  11. Experimental Design of Formulations Utilizing High Dimensional Model Representation.

    Science.gov (United States)

    Li, Genyuan; Bastian, Caleb; Welsh, William; Rabitz, Herschel

    2015-07-23

    Many applications involve formulations or mixtures where large numbers of components are possible to choose from, but a final composition with only a few components is sought. Finding suitable binary or ternary mixtures from all the permissible components often relies on simplex-lattice sampling in traditional design of experiments (DoE), which requires performing a large number of experiments even for just tens of permissible components. The effect rises very rapidly with increasing numbers of components and can readily become impractical. This paper proposes constructing a single model for a mixture containing all permissible components from just a modest number of experiments. Yet the model is capable of satisfactorily predicting the performance for full as well as all possible binary and ternary component mixtures. To achieve this goal, we utilize biased random sampling combined with high dimensional model representation (HDMR) to replace DoE simplex-lattice design. Compared with DoE, the required number of experiments is significantly reduced, especially when the number of permissible components is large. This study is illustrated with a solubility model for solvent mixture screening.

  12. Experimental review on interior tire-road noise models

    NARCIS (Netherlands)

    Bekke, Dirk; Bekke, D.A.; Wijnant, Ysbrand H.; de Boer, Andries; Sas, P

    2010-01-01

    Exterior and interior tire-road noise is a common problem for car and tire manufactures. Exterior tire-road noise is bounded by UN-ECE R117 and EC R661/2009. Interior tire-road noise on the other hand is determined by market requirements. Since the beginning of the last century different model

  13. Biliary System Architecture: Experimental Models and Visualization Techniques

    Czech Academy of Sciences Publication Activity Database

    Sarnová, Lenka; Gregor, Martin

    2017-01-01

    Roč. 66, č. 3 (2017), s. 383-390 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LQ1604; GA ČR GA15-23858S Institutional support: RVO:68378050 Keywords : Biliary system * Mouse model * Cholestasis * Visualisation * Morphology Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.461, year: 2016

  14. Experimental model of intracranial arteriovenous shunting in the acute stage.

    Science.gov (United States)

    Numazawa, Shinichi; Sasaki, Tatsuya; Sato, Sonomi; Watanabe, Yoichi; Watanabe, Zenichiro; Kodama, Namio

    2005-06-01

    A model of intracranial arteriovenous (AV) shunting must incorporate local hypoperfusion and simulate the hemodynamics of arteriovenous malformations. In this study, the hemodynamics of an intracranial AV shunt model in the acute stage were clarified. End-to-side anastomoses with a femoral vein graft were performed between a cortical branch of the middle cerebral artery (MCA) and the superior sagittal sinus in anesthetized dogs. Local cerebral blood flow (l-CBF) was measured by laser Doppler blood flowmetry. l-CBF decreased suddenly by 34.2% when the shunt was opened in the ipsilateral MCA territory. Upon re-occlusion, l-CBF immediately equaled or exceeded the pre-opening value and returned to the pre-opening value within the next 15 minutes. Opening the shunt produced little change in l-CBF in the territory of the ipsilateral or contralateral anterior cerebral artery. The decrease in l-CBF was correlated with shunt volume only in the MCA territory. l-CBF manifested a PaCO(2)-dependent increase before shunt opening, but CO(2) reactivity was impaired after opening the shunt only in the MCA territory. This dog model features local hypoperfusion due to intracranial AV shunting and disturbance of CO(2) reactivity in the acute stage. The hemodynamics of this model will be confirmed in the chronic stage.

  15. Cellulose and the twofold screw axis: Modeling and experimental arguments

    Science.gov (United States)

    Crystallography indicates that molecules in crystalline cellulose either have 2-fold screw-axis (21) symmetry or closely approximate it, leading to short distances between H4 and H1' across the glycosidic linkage. Therefore, modeling studies of cellobiose often show elevated energies for 21 structur...

  16. Experimental validation and calibration of pedestrian loading models for footbridges

    DEFF Research Database (Denmark)

    Ricciardelli, Fransesco; Briatico, C; Ingólfsson, Einar Thór

    2006-01-01

    Different patterns of pedestrian loading of footbridges exist, whose occurrence depends on a number of parameters, such as the bridge span, frequency, damping and mass, and the pedestrian density and activity. In this paper analytical models for the transient action of one walker and for the stat...

  17. Mass spectrometry analysis of hepcidin peptides in experimental mouse models

    NARCIS (Netherlands)

    Tjalsma, H.; Laarakkers, C.M.; Swelm, R.P. van; Theurl, M.; Theurl, I.; Kemna, E.H.J.M.; Burgt, Y.E. van der; Venselaar, H.; Dutilh, B.E.; Russel, F.G.M.; Weiss, G.; Masereeuw, R.; Fleming, R.E.; Swinkels, D.W.

    2011-01-01

    The mouse is a valuable model for unravelling the role of hepcidin in iron homeostasis, however, such studies still report hepcidin mRNA levels as a surrogate marker for bioactive hepcidin in its pivotal function to block ferroportin-mediated iron transport. Here, we aimed to assess bioactive mouse

  18. Theoretical modeling and experimental analyses of laminated wood composite poles

    Science.gov (United States)

    Cheng Piao; Todd F. Shupe; Vijaya Gopu; Chung Y. Hse

    2005-01-01

    Wood laminated composite poles consist of trapezoid-shaped wood strips bonded with synthetic resin. The thick-walled hollow poles had adequate strength and stiffness properties and were a promising substitute for solid wood poles. It was necessary to develop theoretical models to facilitate the manufacture and future installation and maintenance of this novel...

  19. Numerical modelling and experimental assessment of concrete spalling in fire

    NARCIS (Netherlands)

    Shamalta, M.; Breunese, A.; Peelen, W.; Fellinger, J.

    2005-01-01

    In this paper, the phenomenon of spalling of concrete in fire has been studied using a numerical model. Spalling is the violent or non-violent breaking off of layers or pieces of concrete when it is exposed to high temperatures as experienced in fires. The types and mechanisms of spalling have been

  20. Hydrodynamic Modelling and Experimental Analysis of FE-DMFC Stacks

    Science.gov (United States)

    Kablou, Yashar

    Direct methanol fuel cells (DMFCs) present some unique features such as having liquid fuel, quick refueling process, compact design and high energy density. These characteristics make them incredibly suitable as a promising power source for portable electronic applications, such as cell phones or laptop computers. Despite of these positive aspects, the commercial development of DMFCs has nevertheless been hindered by some important issues such as, carbon dioxide formation at the anode compartment and, methanol crossover through the membrane. Many researchers have tried to model the two-phase flow behavior inside the DMFC anode compartment using the "homogenous flow modelling" approach, which has proven to be inaccurate specially when dealing with DMFC stacks. On the other hand, several strategies to prevent methanol crossover have been suggested in the literature, including the use of a flowing electrolyte between the DMFC anode and cathode compartments. Preliminary tests on flowing electrolyte direct methanol fuel cells (FE-DMFCs) have shown promising results; however, further investigation should be carried out on the stack level. In the first part of this study, a quasi two-dimensional numerical model was developed, to predict the two-phase flow behavior within the DMFC anode compartment, both in single cell and stack levels. Various types of flow modelling approaches and void fraction correlations were utilized to estimate the pressure drop across the anode compartment. It was found that the "separated flow modelling" approach, as well as CISE correlation for void fraction (developed at the CISE labs in Milan), yield the best results. In the second part, a five-cell FE-DMFC stack unit with a parallel serpentine flow bed design and U-type manifold configuration, was developed and tested at various operating conditions. It was found that, the flowing electrolyte effectively reduced methanol crossover and, improved the stack performance.

  1. The experimentation of learning models viewed from interpersonal intelligence

    Science.gov (United States)

    Gerhana, M. T. C.; Mardiyana; Pramudya, I.

    2017-11-01

    This research aimed to know experimentation Project Based Learning (PjBL) and Problem Based Learning (PBL) with scientific approach viewed from interpersonal intelligence. The subjects of this research were grade X MIPA students in SMA N 1 Minggir. This research instruments used were test and questionnaire. The result of the research showed that: (1) Students subjected PjBL with scientific approach had a better learning achievement than PBL with scientific approach; (2) students with high interpersonal intelligence had a better learning achievement than low and medium interpersonal intelligence, students with low and medium interpersonal intelligence gave the same learning achievement; (3) In PjBL, students with high interpersonal intelligence had a better learning achievement than low and medium interpersonal intelligence, students with low and medium interpersonal intelligence gave the same learning achievement. In PBL, students with high and medium interpersonal intelligence had a better learning achievement than low interpersonal intelligence, students with high and medium interpersonal intelligence gave the same learning achievement; (4) In high interpersonal intelligence, students subjected PjBL had a better learning achievement than students subjected PBL. In medium and low interpersonal intelligence, students subjected PjBL gave same learning achievement than students subjected PBL.

  2. Triggering the mechanical (slip) instability in laboratory experimental model

    Science.gov (United States)

    Devidze, M.; Chelidze, T.; Varamashvili, N.

    2008-05-01

    Recent laboratory experiments testify possibility of significant influence of elastic and electromagnetic (EM) fields to affect (hamper or initiate) slip. This work focuses on experimental test of possibility of triggering the mechanical instability of system, which is close to the critical state, by electromagnetic pulses. The mechanical system consisted of two pieces of rock (basalt).This system is driven close to the critical state, namely by placing the rock plate on the inclined supporting sample at the slope angle less than, but close to the critical slip angle. In this state the triggering of mechanical instability by some weak impact such as electrical pulse became more probable. It has been found that when the EM field is nearly parallel to the slip plane the EM impact initiates the slip with the probability at the voltage and with the probability at . On the other hand, if the EM field is normal to the slip surface, application of EM pulse hampers the slip. The slope of support in experiment is analogue of tectonic stress in natural conditions. We conclude that our laboratory experiments give a sound principal basis for the interpretation of the field data on the control of seismic regime by relatively weak natural or artificial perturbations; of course, in the earth crust the detailed physical mechanisms of coupling between tectonic forces and superimposed perturbations may be different.

  3. Congenital Transmission of Experimental Leishmaniasis in a Hamster Model

    Science.gov (United States)

    Osorio, Yaneth; Rodriguez, Luz D.; Bonilla, Diana L.; Peniche, Alex G.; Henao, Hector; Saldarriaga, Omar; Travi, Bruno L.

    2012-01-01

    Little information is available on transplacental transmission of Leishmania spp. We determined the frequency and impact of congenital infection caused by Leishmania panamensis or L. donovani in experimentally infected hamsters. A polymerase chain reaction showed that congenital transmission occurred in 25.8% (24 of 93) of offspring born to L. panamensis-infected hamsters and 14.6% (11 of 75) offspring born to L. donovani-infected hamsters. Mortality during lactation was higher in offspring born to L. panamensis-infected hamsters and offspring born to L. donovani-infected hamsters than controls, and lymphoproliferation to Leishmania was more frequent in offspring born to L. panamensis-infected hamsters (17.4%, 11 of 63) than in offspring born to L. donovani-infected hamsters (8.5%, 3 of 35). After weaning, only offspring born to L. donovani-infected hamsters had lower weight gain (P < 0.001) and hematocrit levels (P = 0.0045) than controls. Challenge of offspring born to L. panamensis-infected hamsters with L. panamensis showed no differences in lesion evolution, and offspring born to L. donovani-infected hamsters were more susceptible to L. donovani challenge than controls. Consequently, prenatal exposure of hamsters to L. donovani significantly increased the mortality risk and susceptibility to secondary homologous infection. PMID:22556079

  4. Granulocytes as effective anticancer agent in experimental solid tumor models.

    Science.gov (United States)

    Jaganjac, Morana; Poljak-Blazi, Marija; Kirac, Iva; Borovic, Suzana; Joerg Schaur, Rudolf; Zarkovic, Neven

    2010-12-01

    The aim of the study was to elucidate the effects of murine granulocytes on the growth of solid murine tumors when administrated in the vicinity of W256 carcinoma growing in Sprague Dawley rats, and in the vicinity of Ehrlich ascites tumor (EAT) growing in BALBc mice. The administration of granulocytes significantly improved the survival of W256-bearing rats, and increased the tumor regression incidence from 17% up to 75%. Rats with regressing tumors had 2.5 times increased levels of granulocytes in peripheral blood, which were also cytotoxic in vitro for W256 carcinoma cells. However, blood levels of cytokine-induced neutrophil chemoattractant-2, tumor necrosis factor α and interleukin 6 were similar between rats with regressing tumors and control healthy rats, suggesting that the observed regression of W256 carcinoma was caused by specific anticancer effects of the applied granulocytes. Anticancer effects of granulocytes were also found in BALBc mice bearing solid form of EAT, resulting in a 20% increase of survival in EAT-bearing mice. Therefore, the administration of granulocytes, isolated from healthy animals and applied at the site of solid tumors in rats and in mice, reduced experimental tumor growth, and extended the survival of tumor-bearing animals, while in some rats it even caused a W256 regression. Copyright © 2010 Elsevier GmbH. All rights reserved.

  5. Vaporization inside a mini microfin tube: experimental results and modeling

    Science.gov (United States)

    Diani, A.; Rossetto, L.

    2015-11-01

    This paper proposes a comparison among the common R134a and the extremely low GWP refrigerant R1234yf during vaporization inside a mini microfin tube. This microfin tube has an internal diameter of 2.4 mm, it has 40 fins, with a fin height of 0.12 mm. Due to the high heat transfer coefficients shown by this tube, this technology can lead to a refrigerant charge reduction. Tests were run in the Heat Transfer in Micro Geometries Lab of the Dipartimento di Ingegneria Industriale of the Università di Padova. Mass velocities range between 375 and 940 kg m-2 s-1, heat fluxes from 10 to 50 kW m-2, vapour qualities from 0.10 to 0.99, at a saturation temperature of 30°C. The comparison among the two fluids is proposed at the same operating conditions, in order to highlight the heat transfer and pressure drop differences among the two refrigerants. In addition, two correlations are proposed to estimate the heat transfer coefficient and frictional pressure drop during refrigerant flow boiling inside mini microfin tubes. These correlations well predict the experimental values, and thus they can be used as a useful tool to design evaporators based on these mini microfin tubes.

  6. Experimental Errors in QSAR Modeling Sets: What We Can Do and What We Cannot Do.

    Science.gov (United States)

    Zhao, Linlin; Wang, Wenyi; Sedykh, Alexander; Zhu, Hao

    2017-06-30

    Numerous chemical data sets have become available for quantitative structure-activity relationship (QSAR) modeling studies. However, the quality of different data sources may be different based on the nature of experimental protocols. Therefore, potential experimental errors in the modeling sets may lead to the development of poor QSAR models and further affect the predictions of new compounds. In this study, we explored the relationship between the ratio of questionable data in the modeling sets, which was obtained by simulating experimental errors, and the QSAR modeling performance. To this end, we used eight data sets (four continuous endpoints and four categorical endpoints) that have been extensively curated both in-house and by our collaborators to create over 1800 various QSAR models. Each data set was duplicated to create several new modeling sets with different ratios of simulated experimental errors (i.e., randomizing the activities of part of the compounds) in the modeling process. A fivefold cross-validation process was used to evaluate the modeling performance, which deteriorates when the ratio of experimental errors increases. All of the resulting models were also used to predict external sets of new compounds, which were excluded at the beginning of the modeling process. The modeling results showed that the compounds with relatively large prediction errors in cross-validation processes are likely to be those with simulated experimental errors. However, after removing a certain number of compounds with large prediction errors in the cross-validation process, the external predictions of new compounds did not show improvement. Our conclusion is that the QSAR predictions, especially consensus predictions, can identify compounds with potential experimental errors. But removing those compounds by the cross-validation procedure is not a reasonable means to improve model predictivity due to overfitting.

  7. DMFC performance and methanol cross-over: Experimental analysis and model validation

    Energy Technology Data Exchange (ETDEWEB)

    Casalegno, A.; Marchesi, R. [Dipartimento di Energia, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2008-10-15

    A combined experimental and modelling approach is proposed to analyze methanol cross-over and its effect on DMFC performance. The experimental analysis is performed in order to allow an accurate investigation of methanol cross-over influence on DMFC performance, hence measurements were characterized in terms of uncertainty and reproducibility. The findings suggest that methanol cross-over is mainly determined by diffusion transport and affects cell performance partly via methanol electro-oxidation at the cathode. The modelling analysis is carried out to further investigate methanol cross-over phenomenon. A simple model evaluates the effectiveness of two proposed interpretations regarding methanol cross-over and its effects. The model is validated using the experimental data gathered. Both the experimental analysis and the proposed and validated model allow a substantial step forward in the understanding of the main phenomena associated with methanol cross-over. The findings confirm the possibility to reduce methanol cross-over by optimizing anode feeding. (author)

  8. Transmission resonance Raman spectroscopy: experimental results versus theoretical model calculations.

    Science.gov (United States)

    Gonzálvez, Alicia G; González Ureña, Ángel

    2012-10-01

    A laser spectroscopic technique is described that combines transmission and resonance-enhanced Raman inelastic scattering together with low laser power (Raman signal dependence on the sample thickness is also presented. Essentially, the model considers the sample to be homogeneous and describes the underlying physics using only three parameters: the Raman cross-section, the laser-radiation attenuation cross-section, and the Raman signal attenuation cross-section. The model was applied successfully to describe the sample-size dependence of the Raman signal in both β-carotene standards and carrot roots. The present technique could be useful for direct, fast, and nondestructive investigations in food quality control and analytical or physiological studies of animal and human tissues.

  9. Experimental exploration of diffusion panel labyrinth in scale model

    Science.gov (United States)

    Vance, Mandi M.

    Small rehearsal and performance venues often lack the rich reverberation found in larger spaces. Higini Arau-Puchades has designed and implemented a system of diffusion panels in the Orchestra Rehearsal Room at the Great Theatre Liceu and the Tonhalle St. Gallen that lengthen the reverberation time. These panels defy traditional room acoustics theory which holds that adding material to a room will shorten the reverberation time. This work explores several versions of Arau-Puchades' panels and room characteristics in scale model. Reverberation times are taken from room impulse response measurements in order to better understand the unusual phenomenon. Scale modeling enables many tests but has limitations in its accuracy due to the higher frequency range involved. Further investigations are necessary to establish how the sound energy interacts with the diffusion panels and confirm their validity in a range of applications.

  10. Developing Experimental Models for NASA Missions with ASSL

    Directory of Open Access Journals (Sweden)

    Emil Vassev

    2010-03-01

    Full Text Available NASA's new age of space exploration augurs great promise for deep space exploration missions whereby spacecraft should be independent, autonomous, and smart. Nowadays NASA increasingly relies on the concepts of autonomic computing, exploiting these to increase the survivability of remote missions, particularly when human tending is not feasible. Autonomic computing has been recognized as a promising approach for the development of self-managing spacecraft systems that employ onboard intelligence and rely less on control links. The Autonomic System Specification Language (ASSL is a framework for formally specifying and generating autonomic systems. As part of long-term research targeted at the development of models for space exploration missions that rely on principles of autonomic computing, we have employed ASSL to develop formal models and generate functional prototypes for NASA missions. This helps to validate features and perform experiments through simulation. Here, we discuss our work on developing such missions with ASSL.

  11. Experimental Model for the Study of Periodontal Wound Healing

    Science.gov (United States)

    1991-05-01

    efficacy of various adjunctive materials. An additional variable that can prohibit the comparison of wound healing studies is the diversity of animal...dissimilarities exist between this model and the human. For example, dental anatomy, oral microbiota , hygiene, diet, and immune response can vary...3 mm. One or two control sites were created per arch. The flaps were repositioned and sutured with 4-0 plain gut suture. Intramuscular Combiotic

  12. Numerical Modeling of a Ducted Rocket Combustor With Experimental Validation

    OpenAIRE

    Hewitt, Patrick

    2008-01-01

    The present work was conducted with the intent of developing a high-fidelity numerical model of a unique combustion flow problem combining multi-phase fuel injection with substantial momentum and temperature into a highly complex turbulent flow. This important problem is very different from typical and more widely known liquid fuel combustion problems and is found in practice in pulverized coal combustors and ducted rocket ramjets. As the ducted rocket engine cycle is only now finding wides...

  13. Cuttings Transport Models and Experimental Visualization of Underbalanced Horizontal Drilling

    OpenAIRE

    Na Wei; YingFeng Meng; Gao Li; LiPing Wan; ZhaoYang Xu; XiaoFeng Xu; YuRui Zhang

    2013-01-01

    Aerated underbalanced horizontal drilling technology has become the focus of the drilling industry at home and abroad, and one of the engineering core issues is the horizontal borehole cleaning. Therefore, calculating the minimum injection volume of gas and liquid accurately is essential for the construction in aerated underbalanced horizontal drilling. This paper establishes a physical model of carrying cuttings and borehole cleaning in wellbore of horizontal well and a critical transport ma...

  14. Wideband Channel Modeling in Real Atmospheric Environments with Experimental Evaluation

    Science.gov (United States)

    2013-04-01

    received signal will experience ISI and the channel is considered wideband. If either the transmitter or receiver is mobile or the environment is not...are commonly used in spread spectrum communication systems such as Code Division Multiple Access ( CDMA ) systems. Narrowband interference mitigation...Model (APM) for Mobile Radio Applications,” IEEE Trans. Antennas and Propagation, vol. 54, no. 10 (October), pp. 2869–2877. [5] A. Barrios. 1995

  15. Blister growth in zirconium alloys: experimentation and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Domizzi, G. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Dept. de Materiales; Enrique, R.A. [Instituto Balseiro, Universidad Nacional de Cuyo and Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche (Argentina); Ovejero-Garcia, J. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Dept. de Materiales; Buscaglia, G.C. [Instituto Balseiro, Universidad Nacional de Cuyo and Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche (Argentina)]|[Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche (Argentina)

    1996-04-01

    Hydrogen redistribution in the presence of a cold spot is considered, with hydrogen concentrations above the solid-solubility limit and thus with hydrogen flowing through a hydride-matrix mixture. Fully-hydrided regions (frequently called blisters) grow in the samples, beginning at the cold spot. Under equivalent conditions, the experiment is carried out on several Zr-2.5% Nb samples, allowing for the hydrogen migration times to vary from 1.10{sup 5} to 6.10{sup 5} s, so as to construct a blister-growth curve. Metallographic examination of the samples is performed before and after the imposition of the thermal gradient. A mathematical model is then presented, and the corresponding equations are numerically solved by means of a finite element method, refining the discretization so as to render approximation errors unimportant. Agreement between model and experiment is shown to be quite good for migration times greater than 3.10{sup 5} s. For shorter times, implying small blisters around the cold spot, discrepancies arise between model and experiment, which are attributed to errors in estimating the local temperature field near the sample surface. (orig.).

  16. Radiative transfer model for contaminated slabs : experimental validations

    CERN Document Server

    Andrieu, François; Schmitt, Bernard; Douté, Sylvain; Brissaud, Olivier

    2015-01-01

    This article presents a set of spectro-goniometric measurements of different water ice samples and the comparison with an approximated radiative transfer model. The experiments were done using the spectro-radiogoniometer described in Brissaud et al. (2004). The radiative transfer model assumes an isotropization of the flux after the second interface and is fully described in Andrieu et al. (2015). Two kind of experiments were conducted. First, the specular spot was closely investigated, at high angular resolution, at the wavelength of $1.5\\,\\mbox{\\mu m}$, where ice behaves as a very absorbing media. Second, the bidirectional reflectance was sampled at various geometries, including low phase angles on 61 wavelengths ranging from $0.8\\,\\mbox{\\mu m}$ to $2.0\\,\\mbox{\\mu m}$. In order to validate the model, we made a qualitative test to demonstrate the relative isotropization of the flux. We also conducted quantitative assessments by using a bayesian inversion method in order to estimate the parameters (e.g. sampl...

  17. Cu/Zn Thermal Conductivity: Experimental And ANFIS Modelling

    Directory of Open Access Journals (Sweden)

    Zaid S. Kareem

    2018-01-01

    Full Text Available Nanofluids are fluids within which particles of nanometre sizes are suspended. In terms of thermal characteristics, nanofluids have a greater heat transfer coefficient and thermal conductivity than other traditional fluids. Bimetallic core/shell Cu/Zn particles of nanometre sizes are novel invented nanoparticle materials with considerable variations in its applications. The particles of nanometre size were suspended in a base fluid for the preparation of nanofluids for different volume fractions. A coated transitory hot wire device were built and standardized and this was subsequently employed for the determination of heat conductivities of the nanofluids for bimetallic ratios, volume fraction, base fluid temperatures and base fluids thermal conductivity. The Adaptive neuro fuzzy inference system (ANFIS model was subsequently employed for modelling the determined results generated. A random test of 20% from various nanofluids showed a deviation less than 1% between measured and modeled results. It was inferred that heat conductivities increase with increase in the particle volume concentrations, especially when the later one at value of 1, the heat conductivities ratio approach to 1.35. Nevertheless, the shape and the method of preparing the particles of nanometre size reveals anomalous enhancements in heat conductivities of bimetallic compared to monocular metallic nanofluids.

  18. Experimental model of human corpus cavernosum smooth muscle relaxation

    Directory of Open Access Journals (Sweden)

    Rommel P. Regadas

    2010-08-01

    Full Text Available PURPOSE: To describe a technique for en bloc harvesting of the corpus cavernosum, cavernous artery and urethra from transplant organ donors and contraction-relaxation experiments with corpus cavernosum smooth muscle. MATERIALS AND METHODS: The corpus cavernosum was dissected to the point of attachment with the crus penis. A 3 cm segment (corpus cavernosum and urethra was isolated and placed in ice-cold sterile transportation buffer. Under magnification, the cavernous artery was dissected. Thus, 2 cm fragments of cavernous artery and corpus cavernosum were obtained. Strips measuring 3 x 3 x 8 mm3 were then mounted vertically in an isolated organ bath device. Contractions were measured isometrically with a Narco-Biosystems force displacement transducer (model F-60, Narco-Biosystems, Houston, TX, USA and recorded on a 4-channel Narco-Biosystems desk model polygraph. RESULTS: Phenylephrine (1µM was used to induce tonic contractions in the corpus cavernosum (3 - 5 g tension and cavernous artery (0.5 - 1g tension until reaching a plateau. After precontraction, smooth muscle relaxants were used to produce relaxation-response curves (10-12M to 10-4 M. Sodium nitroprusside was used as a relaxation control. CONCLUSION: The harvesting technique and the smooth muscle contraction-relaxation model described in this study were shown to be useful instruments in the search for new drugs for the treatment of human erectile dysfunction.

  19. Experimental model of human corpus cavernosum smooth muscle relaxation.

    Science.gov (United States)

    Regadas, Rommel P; Moraes, Maria E A; Mesquita, Francisco J C; Cerqueira, Joao B G; Gonzaga-Silva, Lucio F

    2010-01-01

    To describe a technique for en bloc harvesting of the corpus cavernosum, cavernous artery and urethra from transplant organ donors and contraction-relaxation experiments with corpus cavernosum smooth muscle. The corpus cavernosum was dissected to the point of attachment with the crus penis. A 3 cm segment (corpus cavernosum and urethra) was isolated and placed in ice-cold sterile transportation buffer. Under magnification, the cavernous artery was dissected. Thus, 2 cm fragments of cavernous artery and corpus cavernosum were obtained. Strips measuring 3 x 3 x 8 mm(3) were then mounted vertically in an isolated organ bath device. Contractions were measured isometrically with a Narco-Biosystems force displacement transducer (model F-60, Narco-Biosystems, Houston, TX, USA) and recorded on a 4-channel Narco-Biosystems desk model polygraph. Phenylephrine (1 microM) was used to induce tonic contractions in the corpus cavernosum (3-5 g tension) and cavernous artery (0.5-1 g tension) until reaching a plateau. After precontraction, smooth muscle relaxants were used to produce relaxation-response curves (10(-12) M to 10(-4) M). Sodium nitroprusside was used as a relaxation control. The harvesting technique and the smooth muscle contraction-relaxation model described in this study were shown to be useful instruments in the search for new drugs for the treatment of human erectile dysfunction.

  20. JANNUS: experimental validation at the scale of atomic modelling

    Science.gov (United States)

    Serruys, Yves; Ruault, Marie-Odile; Trocellier, Patrick; Miro, Sandrine; Barbu, Alain; Boulanger, Loïc; Kaïtasov, Odile; Henry, Sylvain; Leseigneur, Olivier; Trouslard, Philippe; Pellegrino, Stéphanie; Vaubaillon, Sylvain

    2008-04-01

    Ion irradiation is well suited to simulate neutron irradiation because primary knock-on atoms (PKA) produced by neutron collisions are self ions of the target. As the main difference, the energy spectrum of ion-produced PKAs is somewhat broader than in the case of fast neutrons. Studies of the combined effects of target damaging, ion implantation effects, helium and hydrogen production, and the occurrence of nuclear reactions should be performed by co-irradiation experiments (dual or triple beam irradiation). The JANNUS project (Joint Accelerators for Nanosciences and NUclear Simulation) was started in 2002 in the frame of a collaboration between CEA (Commissariat à l'Énergie Atomique) and CNRS-IN2P3 (Centre National de la Recherche Scientifique-Institut National de Physique Nucléaire et de Physique des Particules). Two experimental sites are involved. At Saclay, three electrostatic accelerators are being coupled: a new 3 MV Pelletron™ machine equipped with an ECR multi-charged ion source, a 2.5 MV single ended Van de Graaff and a 2.25 MV General Ionex tandem. At Orsay, the 2 MV tandem ARAMIS and the 190 kV ion implanter IRMA are being coupled with a 200 kV TECNAI™ transmission electron microscope to allow simultaneous co-irradiation and observation. This paper will first discuss both advantages and limitations of the use of ion beam irradiation to simulate neutron irradiation. A technical description of both set-ups is then presented, and some details will be given concerning multi-irradiation facilities running worldwide. The main application fields of JANNUS will be further detailed. To cite this article: Y. Serruys et al., C. R. Physique 9 (2008).

  1. Selecting appropriate dynamic model for elastomeric engine mounts to approximate experimental FRF data of them

    Directory of Open Access Journals (Sweden)

    Jahani K.

    2010-06-01

    Full Text Available In this paper, the capabilities of different dynamic analytical models to approximate experimentally measured FRFs of elastomeric engine mounts of a passenger car are investigated. Artificial neural networks is used in identifying the dynamic characteristics of each model. Impact hammer test is implemented to extract measured FRFs and harmonic analysis is used to get the counterpart response of the models. Here linear and orthotropic material properties are considered for elastomeric media. The frequency response functions of updated models are compared with experimentally detected ones and advantages and limitations of each model to simulate the real dynamic behaviour of elastomeric engine mounts are discussed

  2. Search for periodicities in experimental data using an autoregression data model

    CERN Document Server

    Belashev, B Z

    2001-01-01

    To process data obtained during interference experiments in high-energy physics, methods of spectral analysis are employed. Methods of spectral analysis, in which an autoregression model of experimental data is used, such as the maximum entropy technique as well as Pisarenko and Prony's method, are described. To show the potentials of the methods, experimental and simulated hummed data are discussed as an example.

  3. An Analytical Hierarchy Process Model for the Evaluation of College Experimental Teaching Quality

    Science.gov (United States)

    Yin, Qingli

    2013-01-01

    Taking into account the characteristics of college experimental teaching, through investigaton and analysis, evaluation indices and an Analytical Hierarchy Process (AHP) model of experimental teaching quality have been established following the analytical hierarchy process method, and the evaluation indices have been given reasonable weights. An…

  4. Experimental and numerical modeling of wind flow over complex topography

    Science.gov (United States)

    Rasouli, Ashkan

    Wind mapping is of utmost importance in various wind engineering, wind environment, and wind energy applications. The available wind atlases usually provide wind data with low resolutions relative to the wind turbine height and size and usually neglect the effect of topographic features with relatively large or sudden changes in elevation. Developing a cost effective methodology to predict the wind patterns and to obtain wind maps over any topographic terrain is absolutely needed for wind turbine/farm siting. As the previous analytic and empirical attempts to resolve the flow over topographic features were limited to basic geometries that hardly exist in nature, applying Particle Image Velocimetry (PIV) measurement techniques in wind tunnel and Computational Fluid Dynamics (CFD) techniques in numerical simulation of the flow over topography seems to be the best alternative solution to the problem. PIV measurements and CFD simulations are carried out on a 1:3000 scale model of complex topographic area. Three distinct topographic features are investigated: a valley, a ridge and a hill. The PIV measurements compare well with hot-wire based mean velocity profiles for the three cases. Moreover, the turbulence intensity profiles match well for flow regions without recirculation. The ridge wake region shows discrepancies between the two techniques which are attributed to the complexity of the flow in this region and limitations of both techniques. A procedure incorporating Geographic Information System (GIS) and surface modeling techniques is introduced to build the CFD model of a complex terrain starting from the existing topography maps with desired resolutions. Moreover, a new approach is made to simulate the terrain roughness up to ultimate roughness heights, by implementing arrays of bell-shaped roughness elements in the CFD model. The velocity profiles and velocity vectors were compared with the PIV measurements and were found to be in good agreement near the ground

  5. Tesla Coil Theoretical Model and its Experimental Verification

    OpenAIRE

    Voitkans Janis; Voitkans Arnis

    2015-01-01

    In this paper a theoretical model of Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wire form, where the line voltage is measured across electrically neutral space. By applying the principle of equivalence of single-wire and two-wire schemes an equivalent two-wire scheme can be found for a single-wire scheme and the already known long line theory can be applied to the Tesla coil. A new method of multiple reflections is develope...

  6. Gravity research on plants: use of single cell experimental models

    Directory of Open Access Journals (Sweden)

    Youssef eChebli

    2011-09-01

    Full Text Available Future space missions and implementation of permanent bases on Moon and Mars will greatly depend on the availability of ambient air and sustainable food supply. Therefore, understanding the effects of altered gravity conditions on plant metabolism and growth is vital for space missions and extra-terrestrial human existence. In this mini-review we summarize how plant cells are thought to perceive changes in magnitude and orientation of the gravity vector. The particular advantages of several single celled model systems for gravity research are explored and an overview over recent advancements and potential use of these systems is provided.

  7. Experimental model of occlusal trauma in mouse periodontal tissues.

    OpenAIRE

    Fujii, T; Takaya, T; Mimura, H; Osuga, N; Matsuda, S; Nakano, K

    2014-01-01

    The aim of this study was to establish a model, which can be used to investigate the response of periodontal tissues to excessive occlusal loading in mice by observing histopathological changes. The experiment was performed on ten 7-week-old ddY male mice. Under general anesthesia by intraperitoneal injectionpentobarbital sodium, a micro-plus-screwpin (head part, 1.7mm in diameter, thickness 0.5mm thickness) was screwed into the pulp cavity of the upper-left-first molar. R_mCT images of the e...

  8. [Experimental study on quick preparation of osteoporosis in vitro model].

    Science.gov (United States)

    Shang, Qing; Liu, Zongchao; Lu, Xiaobo

    2013-03-01

    To establish a rapid, simple, and economic method to prepare osteoporosis (OP) in vitro model. Eighty pairs of fresh goat femur were collected from 18-month-old female goats and were randomly divided into 4 groups (20 pairs in each group). The femur was immersed decalcifying solution (18% EDTA) for 1-5 days (group B), 6-10 days (group C), and 11-15 days (group D), while group A had no treatment as control. Four pairs of femur were taken out every day. Quantitative computed tomography was used to scan the medial and lateral femoral condyles, and the bone mineral density (BMD) was calculated. Electronic universal testing machine was used to do three-point bending test and compress and tensile ultimate strenght test, and the mechanical parameters for femur were calculated. With demineralized time passing, BMD of the medial and lateral femoral condyles were downtrend in groups A, B, C, and D, showing significant differences among 4 groups (P 0.05). Compress and tensile ultimate strength test showed that the compress and tensile ultimate strengths were significantly higher in group A than in groups C and D (P 0.05). The 18% EDTA immersing for 6-15 days is a fast, simple, economical method to prepare an OP in vitro model of goat femur.

  9. Experimental Validation of Various Temperature Modells for Semi-Physical Tyre Model Approaches

    Science.gov (United States)

    Hackl, Andreas; Scherndl, Christoph; Hirschberg, Wolfgang; Lex, Cornelia

    2017-10-01

    With increasing level of complexity and automation in the area of automotive engineering, the simulation of safety relevant Advanced Driver Assistance Systems (ADAS) leads to increasing accuracy demands in the description of tyre contact forces. In recent years, with improvement in tyre simulation, the needs for coping with tyre temperatures and the resulting changes in tyre characteristics are rising significantly. Therefore, experimental validation of three different temperature model approaches is carried out, discussed and compared in the scope of this article. To investigate or rather evaluate the range of application of the presented approaches in combination with respect of further implementation in semi-physical tyre models, the main focus lies on the a physical parameterisation. Aside from good modelling accuracy, focus is held on computational time and complexity of the parameterisation process. To evaluate this process and discuss the results, measurements from a Hoosier racing tyre 6.0 / 18.0 10 LCO C2000 from an industrial flat test bench are used. Finally the simulation results are compared with the measurement data.

  10. Actual Usage and Quality of Experimental Colitis Models in Preclinical Efficacy Testing: A Scoping Review

    NARCIS (Netherlands)

    Zeeff, S.B.; Kunne, C.; Bouma, G.; Vries, R.B.M. de; Velde, A.A. Te

    2016-01-01

    BACKGROUND: There is no standardized validated experimental model used to predict human drug response, and the choice of model is not based on systematic evidence. Therefore, we decided to systematically investigate which models are currently used by selecting studies from literature that use

  11. Actual Usage and Quality of Experimental Colitis Models in Preclinical Efficacy Testing: A Scoping Review

    NARCIS (Netherlands)

    Zeeff, Sophia B.; Kunne, Cindy; Bouma, Gerd; de Vries, Rob B.; te Velde, Anje A.

    2016-01-01

    Background:There is no standardized validated experimental model used to predict human drug response, and the choice of model is not based on systematic evidence. Therefore, we decided to systematically investigate which models are currently used by selecting studies from literature that use

  12. Assessment of knee joint pain in experimental rodent models of osteoarthritis.

    Science.gov (United States)

    Piel, Margaret J; Kroin, Jeffrey S; Im, Hee-Jeong

    2015-01-01

    Pain assessment in animal models of osteoarthritis is integral to interpretation of a model's utility in representing the clinical condition, and enabling accurate translational medicine. Here we describe two methods for behavioral pain assessments available for use in animal models of experimental osteoarthritic pain: Von Frey filaments and spontaneous activity monitoring.

  13. [Stomach ulcers in rats. New experimental model and protection by a triterpene healing agent].

    Science.gov (United States)

    Lefournier, C; Poizot, A; Saint-Maur, P

    1977-05-16

    An experimental model using restricted diet and exposure to cold for several weeks was devised. Following a two-week treatment with a triterpen healing agent, the rate of ulcerative lesion was significantly decreased.

  14. Simultaneous Experimentation as a Learning Strategy: Business Model Development Under Uncertainty

    NARCIS (Netherlands)

    Andries, Petra; Debackere, Koenraad; van Looy, Bart

    2013-01-01

    Ventures operating under uncertainty face challenges defining a sustainable value proposition. Six longitudinal case studies reveal two approaches to business model development: focused commitment and simultaneous experimentation. While focused commitment positively affects initial growth, this

  15. Experimental Model Based Feedback Control for Flutter Suppression and Gust Load Alleviation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZONA Technology, Inc. (ZONA) proposes an R&D effort to develop an Experimental Model Based Feedback Control (EMBFC) Framework for the flutter suppression and...

  16. Theoretical temperature model with experimental validation for CLIC Accelerating Structures

    CERN Document Server

    AUTHOR|(CDS)2126138; Vamvakas, Alex; Alme, Johan

    Micron level stability of the Compact Linear Collider (CLIC) components is one of the main requirements to meet the luminosity goal for the future $48 \\,km$ long underground linear accelerator. The radio frequency (RF) power used for beam acceleration causes heat generation within the aligned structures, resulting in mechanical movements and structural deformations. A dedicated control of the air- and water- cooling system in the tunnel is therefore crucial to improve alignment accuracy. This thesis investigates the thermo-mechanical behavior of the CLIC Accelerating Structure (AS). In CLIC, the AS must be aligned to a precision of $10\\,\\mu m$. The thesis shows that a relatively simple theoretical model can be used within reasonable accuracy to predict the temperature response of an AS as a function of the applied RF power. During failure scenarios or maintenance interventions, the RF power is turned off resulting in no heat dissipation and decrease in the overall temperature of the components. The theoretica...

  17. An experimental cyst model established from human unkeratinized vaginal mucosa.

    Science.gov (United States)

    Thompson, I O; van Wyk, C W

    1996-12-01

    Because of the scarcity of sizeable specimens of normal oral mucosa and the availability of human vaginal mucosa, which resembles the lining mucosa of the mouth, we used the latter to establish a human cyst model. Fragments of vaginal mucosa, removed during corrective procedures, were sutured around 2 mm glass balls and implanted into the flanks of nude mice. Thirty-seven specimens were implanted and 31 harvested after 3, 6, 9 and 12 weeks. At 6 weeks the wall of the implanted cyst consisted of recognizable unkeratinized vaginal mucosa but had not healed completely at the sutured edges. From 9 weeks the cyst cavities were healed and the lumens lined by unkeratinized stratified squamous vaginal epithelium. The enclosing connective tissue had retained the characteristics of the lamina propria of the vaginal mucosa and could be distinguished from mouse tissue.

  18. An Experimental and Kinetic Modeling Study of Methyl Decanoate Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Sarathy, S M; Thomson, M J; Pitz, W J; Lu, T

    2010-02-19

    Biodiesel is typically a mixture of long chain fatty acid methyl esters for use in compression ignition engines. Improving biofuel engine performance requires understanding its fundamental combustion properties and the pathways of combustion. This research study presents new combustion data for methyl decanoate in an opposed-flow diffusion flame. An improved detailed chemical kinetic model for methyl decanoate combustion is developed, which serves as the basis for deriving a skeletal mechanism via the direct relation graph method. The novel skeletal mechanism consists of 648 species and 2998 reactions. This mechanism well predicts the methyl decanoate opposed-flow diffusion flame data. The results from the flame simulations indicate that methyl decanoate is consumed via abstraction of hydrogen atoms to produce fuel radicals, which lead to the production of alkenes. The ester moiety in methyl decanoate leads to the formation of low molecular weight oxygenated compounds such as carbon monoxide, formaldehyde, and ketene.

  19. Impaired executive functions in experimental model of temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Fabiane Ochai Ramos

    2016-06-01

    Full Text Available ABSTRACT Objective The present study aimed to investigate cognitive and behavioural changes consistent with attention deficit hyperactivity disorder (ADHD -like behavior in male Wistar rats with temporal lobe epilepsy (TLE. Method Male Wistar rats at 25 day of age were submitted to animal model of TLE by pilocarpine injection (350 mg/kg, ip and a control group received saline 0.9%. The animals were continuously video monitored up to the end of experiments. The behavioural tests (open field, elevated plus maze and operant conditioning box started from 60 days postnatal. Results Animals with TLE exhibited elevated locomotor activity, reduced level of anxiety-related behavior, impulsivity and impaired visuospatial working memory. Conclusion Taken as a whole, we concluded that animals with TLE exhibited some cognitive and behavioural changes consistent with ADHD-like behavior.

  20. Modeling experimental findings on sorption and biodegradation of PAHs

    DEFF Research Database (Denmark)

    Rein, Arno; Smith, K. E. C.; Karlson, U. G.

    2011-01-01

    Polycyclic aromatic hydrocarbons (PAHs) in the environment are to a major degree bound to organic matter or soot particles. It is disputed whether and to which extent the adsorbed fraction of PAH in soil and sediment can be attacked by microbial enzymes, or whether dissolution in aqueous media...... is required. In that case, the degradation depends critically on the bioavailability, or better the bioaccessibility of PAH for microbes. The increasing non-accessibility of PAH with time (‘aging’) may explain the formation of a residual fraction, which has been observed in remediation projects. A unified....... The model was also used to simulate typical scenarios of adsorption (aging) and microbial degradation, in order to identify sensitive parameters and processes. Furthermore, the impact of dissolved organic matter and various types of amendments was studied, which potentially enhance diffusive mass transfer...

  1. Recapitulating Human Gastric Cancer Pathogenesis: Experimental Models of Gastric Cancer

    Science.gov (United States)

    Ding, Lin; El Zaatari, Mohamad

    2017-01-01

    Overview Gastric cancer has been traditionally defined by the Correa paradigm as a progression of sequential pathological events that begins with chronic inflammation [1]. Infection with Helicobacter pylori (H. pylori) is the typical explanation for why the stomach becomes chronically inflamed. Acute gastric inflammation then leads to chronic gastritis, atrophy particularly of acid-secreting parietal cells, metaplasia due to mucous neck cell expansion from trans-differentiation of zymogenic cells to dysplasia and eventually carcinoma [2]. The chapter contains an overview of gastric anatomy and physiology to set the stage for signaling pathways that play a role in gastric tumorigenesis. Finally, the major known mouse models of gastric transformation are critiqued in terms of the rationale behind their generation and contribution to our understanding of human cancer subtypes. PMID:27573785

  2. Experimental and Numerical Analysis of Modelling of Solar Shading

    DEFF Research Database (Denmark)

    Winther, Frederik Vildbrad; Liu, Mingzhe; Heiselberg, Per

    2017-01-01

    The use of solar shading in future low energy office buildings is essential for minimizing energy consumption for building services, while maintaining thermal conditions. Implementing solar shading technologies in energy calculations and thermal building simulation programs is essential in order...... to demonstrate the effect of adaptive solar shading. In order to document the benefits of the shading technology, the description of the shading device in the thermal building simulation software must be described at a reasonably accurate level, related to the specific solar shading device. This research...... presents different approaches for modeling solar shading devices, demonstrating the level of accuracy in relation to measurement conducted in a full-scale façade test facility at Aalborg University. The research bridges the gap between increased complexity of solar shading technologies and the use...

  3. Experimental results and modeling of a dynamic hohlraum on SATURN

    Energy Technology Data Exchange (ETDEWEB)

    Derzon, M.S.; Allshouse, G.O.; Deeney, C.; Leeper, R.J.; Nash, T.J. [Sandia National Labs., Albuquerque, NM (United States); Matuska, W.; Peterson, D.L. [Los Alamos National Lab., NM (United States); MacFarlane, J.J. [Univ. of Wisconsin, Madison, WI (United States); Ryutov, D.D. [Lawrence Livermore National Lab., CA (United States)

    1998-06-01

    Experiments were performed at SATURN, a high current z-pinch, to explore the feasibility of creating a hohlraum by imploding a tungsten wire array onto a low-density foam. Emission measurements in the 200--280 eV energy band were consistent with a 110--135 eV Planckian before the target shock heated, or stagnated, on-axis. Peak pinch radiation temperatures of nominally 160 eV were obtained. Measured early time x-ray emission histories and temperature estimates agree well with modeled performance in the 200--280 eV band using a 2D radiation magneto-hydrodynamics code. However, significant differences are observed in comparisons of the x-ray images and 2D simulations.

  4. Experimental Mouse Model of Lumbar Ligamentum Flavum Hypertrophy.

    Science.gov (United States)

    Saito, Takeyuki; Yokota, Kazuya; Kobayakawa, Kazu; Hara, Masamitsu; Kubota, Kensuke; Harimaya, Katsumi; Kawaguchi, Kenichi; Hayashida, Mitsumasa; Matsumoto, Yoshihiro; Doi, Toshio; Shiba, Keiichiro; Nakashima, Yasuharu; Okada, Seiji

    2017-01-01

    Lumbar spinal canal stenosis (LSCS) is one of the most common spinal disorders in elderly people, with the number of LSCS patients increasing due to the aging of the population. The ligamentum flavum (LF) is a spinal ligament located in the interior of the vertebral canal, and hypertrophy of the LF, which causes the direct compression of the nerve roots and/or cauda equine, is a major cause of LSCS. Although there have been previous studies on LF hypertrophy, its pathomechanism remains unclear. The purpose of this study is to establish a relevant mouse model of LF hypertrophy and to examine disease-related factors. First, we focused on mechanical stress and developed a loading device for applying consecutive mechanical flexion-extension stress to the mouse LF. After 12 weeks of mechanical stress loading, we found that the LF thickness in the stress group was significantly increased in comparison to the control group. In addition, there were significant increases in the area of collagen fibers, the number of LF cells, and the gene expression of several fibrosis-related factors. However, in this mecnanical stress model, there was no macrophage infiltration, angiogenesis, or increase in the expression of transforming growth factor-β1 (TGF-β1), which are characteristic features of LF hypertrophy in LSCS patients. We therefore examined the influence of infiltrating macrophages on LF hypertrophy. After inducing macrophage infiltration by micro-injury to the mouse LF, we found excessive collagen synthesis in the injured site with the increased TGF-β1 expression at 2 weeks after injury, and further confirmed LF hypertrophy at 6 weeks after injury. Our findings demonstrate that mechanical stress is a causative factor for LF hypertrophy and strongly suggest the importance of macrophage infiltration in the progression of LF hypertrophy via the stimulation of collagen production.

  5. A SIMPLE EXPERIMENTAL MODEL OF HEAT SHOCK RESPONSE IN RATS

    Directory of Open Access Journals (Sweden)

    Tufi Neder Meyer

    1998-10-01

    Full Text Available Objective: To obtain a simple model for the elicitation of the heat shock response in rats. Design: Laboratory study. Setting: University research laboratories. Sample: Seventy-nine adult male albino rats (weight range 200 g to 570 g. Procedures: Exposure to heat stress by heating animals in a warm bath for 5 min after their rectal temperatures reached 107.60 F (420 C. Liver and lung samples were collected for heat-shock protein 70 (HSP70 detection (Western analysis. Results: Western analysis was positive for HSP70 in the liver and in the lungs of heated animals. There was a temporal correlation between heating and HSP70 detection: it was strongest 1 day after heating and reduced afterwards. No heated animals died. Conclusion: These data show that heating rats in a warm (45o C bath, according to parameters set in this model, elicits efficiently the heat shock response.OBJETIVO: Obter um modelo simples para tentar esclarecer a resposta ao choque térmico em ratos. LOCAL: Laboratório de pesquisa da Universidade. MÉTODO: Amostra: 79 ratos albinos, adultos, entre 200g a 570g. Procedimentos: Exposição ao calor, em banho quente, por 5 minutos, após a temperatura retal chegar a 42 graus centigrados. Biópsias de fígado e pulmão foram obtidas para detectar a proteina 70 (HSP 70, pelo "Western blot". RESULTADOS: As análises foram positivas nos animais aquecidos, com uma correlação entre aquecimento e constatação da HSP 70. Foi mais elevada no primeiro dia e não houve óbitos nos animais aquecidos. CONCLUSÃO: Os ratos aquecidos a 45 graus centígrados respondem eficientemente ao choque térmico.

  6. Developing Model Benchtop Systems for Microbial Experimental Evolution

    Science.gov (United States)

    Wang, Jonathan; Arismendi, Dillon; Alvarez, Jennifer; Ouandji, Cynthia; Blaich, Justin; Gentry, Diana

    2017-01-01

    Understanding how microbes impact an ecosystem has improved through advances of molecular and genetic tools, but creating complex systems that emulate natural biology goes beyond current technology. In fact, many chemical, biological, and metabolic pathways of even model organisms are still poorly characterized. Even then, standard laboratory techniques for testing microbial impact on environmental change can have many drawbacks; they are time-consuming, labor intensive, and are at risk of contamination. By having an automated process, many of these problems can be reduced or even eliminated. We are developing a benchtop system that can run for long periods of time without the need for human intervention, involve multiple environmental stressors at once, perform real-time adjustments of stressor exposure based on current state of the population, and minimize contamination risks. Our prototype device allows operators to generate an analogue of real world micro-scale ecosystems that can be used to model the effects of disruptive environmental change on microbial ecosystems. It comprises of electronics, mechatronics, and fluidics based systems to control, measure, and evaluate the before and after state of microbial cultures from exposure to environmental stressors. Currently, it uses four parallel growth chambers to perform tests on liquid cultures. To measure the population state, optical sensors (LED/photodiode) are used. Its primary selection pressure is UV-C radiation, a well-studied stressor known for its cell- and DNA-damaging effects and as a mutagen. Future work will involve improving the current growth chambers, as well as implementing additional sensors and environmental stressors into the system. Full integration of multiple culture testing will allow inter-culture comparisons. Besides the temperature and OD sensors, other types of sensors can be integrated such as conductivity, biomass, pH, and dissolved gasses such as CO and O. Additional environmental

  7. Efeitos da clonidina nas respostas cardiovasculares ao pinçamento aórtico infra-renal: estudo experimental no cão Efectos de la clonidina en las respuestas cardiovasculares al pinzamiento aórtico infra-renal: estudio experimental en el can Effects of clonidine on cardiovascular responses to infrarenal aortic cross-clamping: experimental study in dogs

    Directory of Open Access Journals (Sweden)

    Renato Viccário Achôa

    2003-09-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O pinçamento aórtico infra-renal pode determinar alterações cardiovasculares. A clonidina, um alfa2-agonista, determina bradicardia e diminuição da pressão arterial. O objetivo do estudo foi avaliar os efeitos da clonidina sobre a função cardiovascular, em cães submetidos a pinçamento aórtico infra-renal. MÉTODO: O estudo aleatório foi realizado em 16 cães, distribuídos em dois grupos: G Controle - sem a utilização de clonidina e G Clon - clonidina, na dose inicial de 5 µg.kg-1, por via venosa, imediatamente antes do pinçamento aórtico infra-renal, seguido de 2 µg.min-1.m² até o final do estudo. Em todos os animais foi realizada ligadura infra-renal da aorta, por 45 minutos. Os atributos hemodinâmicos foram estudados nos momentos C (controle, após 10 (Ao10 e 25 (Ao25 minutos do pinçamento aórtico, e após 10 (DAo10 e 25 (DAo25 minutos do despinçamento aórtico. RESULTADOS: Durante o pinçamento aórtico, houve diferença significante entre os grupos, em relação à freqüência cardíaca, pressão arterial média e índice cardíaco (G Controle > G Clon. Após o despinçamento aórtico houve diferença significante entre os grupos, em relação à freqüência cardíaca (G Controle > G Clon e pressões do átrio direito e da artéria pulmonar ocluída (G Clon > G Controle. Durante o pinçamento aórtico, houve nos dois grupos, aumento significante das pressões de átrio direito e artéria pulmonar ocluída, dos índices sistólico e do trabalho sistólico do ventrículo esquerdo, e diminuição do índice de resistência vascular pulmonar. No grupo controle houve aumento significante das pressões arterial média e da artéria pulmonar, e dos índices cardíaco e do trabalho sistólico do ventrículo direito. No grupo clonidina, houve diminuição significante da freqüência cardíaca. Após o despinçamento aórtico, houve nos dois grupos: diminuição significante da freqüência card

  8. Experimental modeling of gravity underflow in submarine channels

    Science.gov (United States)

    Islam, Mohammad Ashraful

    Active and relic meandering channels are common on the seafloor adjacent to continental margins. These channels and their associated submarine fan deposits are products of the density-driven gravity flows known as turbidity currents. Unlike natural rivers, few attempts have been made to explore the process of channel meandering in the submarine environment. This research focuses on resolving the flow field of submarine channels by conducting experiments in a large laboratory basin. Saline and particulate density flows were studied in a straight channel, a single bend sinuous channel with vertical sidewalls and a multiple-bend sinuous channel with sloping sidewalls. Instantaneous velocities in steady developed currents were measured using 3-component acoustic Doppler velocity probes. Excess fractional density was measured at selected locations by collecting water sample using a siphon rake. Turbulent kinetic energy and Reynolds stress components are derived from the instantaneous velocity data of the straight channel experiments. Structure functions for mean velocity, Reynolds stress and turbulent kinetic energy profiles are derived by fitting normalized data. The normalized Reynolds-averaged velocity shows excellent similarity collapse while the Reynolds-stress and the turbulent kinetic energy profiles display reasonable similarity. Vertical profiles of the turbulent kinetic energy display two peaks separated by a zone of low turbulence; the ratio of the maximum to the depth-averaged turbulent kinetic energy is approximately 1.5. Theoretical profile of turbulent kinetic energy is derived. Comparisons of experimentally and theoretically derived turbulent kinetic energy profiles show reasonable agreement except at the position of velocity maximum where the theoretical profile displays a very small value. Velocity profiles derived from the measurements with confined flow in the single bend channel reveal that channel curvature drives two helical flow cells, one

  9. Associations between psychological variables and pain in experimental pain models. A systematic review

    DEFF Research Database (Denmark)

    Hansen, M S; Horjales-Araujo, E; Dahl, J B

    2015-01-01

    are predictive of the level of pain following experimental pain models. METHODS: A systematic search on the databases, PubMed, Embase, Cochcrane library, and Clinicaltrials.gov was performed during September 2014. All trials investigating the association between psychological variables and experimental pain...... and experimental pain. CONCLUSION: Psychological factors may have predictive value when investigating experimental pain. However, due to substantial heterogeneity and methodological shortcomings of the published literature, firm conclusions are not possible.......BACKGROUND: The association between pain and psychological characteristics has been widely debated. Thus, it remains unclear whether an individual's psychological profile influences a particular pain experience, or if previous pain experience contributes to a certain psychological profile...

  10. Uniting Epidemiology and Experimental Disease Models for Alcohol-Related Pancreatic Disease

    OpenAIRE

    Setiawan, Veronica Wendy; Monroe, Kristine; Lugea, Aurelia; Yadav, Dhiraj; Pandol, Stephen

    2017-01-01

    Findings from epidemiologic studies and research with experimental animal models provide insights into alcohol-related disease pathogeneses. Epidemiologic data indicate that heavy drinking and smoking are associated with high rates of pancreatic disease. Less clear is the association between lower levels of drinking and pancreatitis. Intriguingly, a very low percentage of drinkers develop clinical pancreatitis. Experimental models demonstrate that alcohol administration alone does not initiat...

  11. Development of a stochastic dynamical model for hermetic compressor's components with experimental investigation

    Science.gov (United States)

    Fontanela, F.; Silva, O. M.; Lenzi, A.; Ritto, T. G.

    2016-08-01

    The analysis of household compressor's components is typically evaluated by using mathematical-mechanical models, and many decisions are taken based on simulations. However, such an investigation is usually performed in a deterministic framework, which cannot consider manufacturing variabilities and epistemic uncertainties. In this paper, a stochastic structural model that considers data and model uncertainties is developed for a discharge pipe connected to a hermetic compressor's shell. An experimental test rig is constructed to test each part separately, and an identification strategy is proposed to fit the stochastic model to experimental results. Finally, the impact of the uncertainties in each structural component on the dynamical responses of the whole system is investigated. It turns out that: (1) the proposed stochastic dynamical model presented very good results when compared to the experimental responses, and (2) uncertainties in the discharge pipe model play an important role in the coupled system dynamics.

  12. Sildenafil after cardiac arrest and infarction; an experimental rat model.

    Science.gov (United States)

    Mennander, Ari A; Vuohelainen, Vilma; Aanismaa, Riikka S; Narkilahti, Susanna; Paavonen, Timo; Tarkka, Matti

    2013-02-01

    Resuscitation after cardiac arrest may lead to ischemia-reperfusion injury and infarction. We evaluated whether sildenafil, a phosphodiesterase-5 inhibitor, has an impact on recovery after cardiac arrest in a rat cardiac transplantation model. Sixty-one Fischer344 rats underwent syngeneic heterotopic cardiac transplantation after ischemia and ligation of the left anterior coronary artery of the heart to yield myocardial infarction (IRI + MI). Of these, 22 rats received subcutaneously injected sildenafil (1 mg/kg/day) (IRI +MI + S). Twenty-three additional grafted animals with transplantation only served as controls with ischemia reperfusion injury (IRI). After 2 days, immunohistochemistry for eNOS, and RT-PCR for iNOS and Aquaporin-7 were performed after graft harvesting and histology. Two days after transplantation, remote intramyocardial arteries were more preserved in IRI + MI + S as compared with IRI +MI and IRI (0.74 ± 0.14, 0.56 ± 0.23 and 0.55 ± 0.22, PSU, p cardiac arrest and ischemia.

  13. Experimental Realization of the Harper-Hofstadter Model

    Science.gov (United States)

    Kennedy, Colin

    Extensions of Berry's phase and the quantum Hall effect have led to the discovery of new states of matter with topological properties. Traditionally, this has been achieved using magnetic fields or spin-orbit interactions, which couple only to charged particles. For neutral ultracold atoms, synthetic magnetic fields have been created that are strong enough to realize the Harper-Hofstadter model. In this talk, I report on work studying Bose-Einstein condensation in the Harper-Hofstadter Hamiltonian with one-half flux quantum per lattice unit cell. The diffraction pattern of the superfluid state directly shows the momentum distribution of the wavefunction, which is gauge-dependent, and it reveals both the reduced symmetry of the vector potential and the degeneracy of the ground state. I present an adiabatic, many-body state preparation protocol via the Mott insulating phase and show the superfluid ground state in a three-dimensional lattice with moderate interactions. I will discuss progress towards a triple-superlattice implementation as well as prospects for exploring exotic states close to the Mott transition.

  14. Compartment syndrome–induced microvascular dysfunction: an experimental rodent model

    Science.gov (United States)

    Lawendy, Abdel-Rahman; Sanders, David W.; Bihari, Aurelia; Parry, Neil; Gray, Daryl; Badhwar, Amit

    2011-01-01

    Background Acute compartment syndrome (CS) is a limb-threatening disease that results from increased intracompartmental pressure. The pathophysiologic mechanisms by which this occurs are poorly understood. This study was designed to measure the effects of increased intracompartmental pressure on skeletal muscle microcirculation, inflammation and cellular injury using intravital videomicroscopy (IVVM) in a clinically relevant small animal model. Methods We induced CS in 10 male Wistar rats (175–250 g), using a saline infusion technique. Intracompartmental pressure was controlled between 30 and 40 mm Hg and maintained for 45 minutes. After fasciotomy, the extensor digitorum longus muscle was visualized using IVVM, and perfusion was quantified. We quantified leukocyte recruitment to measure the inflammatory response. We measured muscle cellular injury using a differential fluorescent staining technique. Results The number of nonperfused capillaries increased from 12.7 (standard error of the mean [SEM] 1.4 ) per mm in the control group to 30.0 (SEM 6.7) per mm following 45 minutes of elevated intracompartmental pressure (CS group; p = 0.031). The mean number of continuously perfused capillaries (and SEM) decreased from 78.4 (3.2) per mm in the control group to 41.4 (6.9) per mm in the CS group (p = 0.001). The proportion of injured cells increased from 5.0% (SEM 2.1%) in the control group to 16.3% (SEM 6.8%) in the CS group (p = 0.006). The mean number of activated leukocytes increased from 3.6 (SEM 0.7) per 100 μm2 in the control group to 8.6 (SEM 1.8) per 100 μm2 in the CS group (p = 0.033). Conclusion Early CS-induced microvascular dysfunction resulted in a decrease in nutritive capillary perfusion and an increase in cellular injury and was associated with a severe acute inflammatory component. PMID:21443836

  15. Diminuição das úlceras por pressão em pacientes com ventilação mecânica aguda prolongada: um estudo quasi-experimental

    Directory of Open Access Journals (Sweden)

    Cecilia Inés Loudet

    Full Text Available RESUMO Objetivo: Determinar a eficácia de um programa de gestão da qualidade para reduzir a incidência e a gravidade de úlceras por pressão em pacientes de terapia intensiva. Métodos: Estudo com metodologia quasi-experimental, antes-e-depois, conduzido em uma unidade de terapia intensiva clínica e cirúrgica. Incluíram-se os pacientes consecutivos que receberam ventilação mecânica por um período igual ou superior a 96 horas. Uma equipe de Melhoria de Processos delineou um processo de intervenção multifacetado, que consistiu de uma sessão educacional, uma lista de verificação de úlcera de pressão, um aplicativo para smartphone para monitoramento de lesões e um conjunto de normas de tomada de decisão, além de prevenção familiar. Resultados: O Grupo Pré-I incluiu 25 pacientes, e o Grupo Pós-I foi constituído por 69 pacientes. A incidência de úlcera de pressão nestes grupos foi de 41 (75% e 37 (54%, respectivamente. O tempo mediano para o desenvolvimento das úlceras por pressão foi de 4,5 (4-5 dias no Grupo Pré-I e 9 (6-20 dias no Grupo Pós-I após a admissão para cada um dos períodos. A incidência de úlceras por pressão de grau avançado foi de 27 (49% no Grupo Pré-I e 7 (10% no Grupo Pós-I. A presença de úlceras por pressão na alta foi de 38 (69% e 18 (26%, respectivamente, para os Grupos Pré-I e Pós-I (p < 0,05 para todas as comparações. A participação da família totalizou 9% no Grupo Pré-I e aumentou para 57% no Grupo Pós-I (p < 0,05. Utilizou-se um modelo de regressão logística para analisar os preditores de úlcera de pressão com grau avançado. A duração da ventilação mecânica e a presença de falência de órgão associaram-se positivamente com o desenvolvimento de úlceras por pressão, enquanto o programa multifacetado de intervenção atuou como fator de proteção. Conclusão: Um programa de qualidade, com base em um aplicativo para smartphone e na participação da fam

  16. Desenvolvimento, Viabilidade e Mortalidade de Imaturos de Aedes (Stegomyia aegypti Linnaeus, em Água de Duas Espécies de Bromélias: Estudo Bibliográfico e Experimental

    Directory of Open Access Journals (Sweden)

    Maria das Graças Guimarães

    2015-12-01

    Full Text Available Resumo. Criadouros naturais de Aedes aegypti Linnaeus podem ser encontrados em bromélias e outros vegetais que apresentem estrutura capaz de armazenar a água. A produtividade dos criadouros está ligada ao volume e à capacidade de manutenção de água, à oferta de nutrientes e à densidade larval e ao número de folhas do vegetal. Há controvérsias entre os pesquisadores sobre o encontro de formas imaturas de Ae. aegypti na água dos reservatórios de bromélias. Este estudo dedicou-se à observação da eclosão de ovos e do desenvolvimento de Ae. aegypti em água de tanques de bromélia Aechmea fasciata (Lindley Baker eNeoregelia compacta (Mez L.B. Smith. Para cada uma das espécies de bromélias três tipos de grupos foram utilizados: dois grupos controles, um contendo água de rega e outro grupo com água dos reservatórios das bromélias sem a presença da microfauna; e o grupo teste, contendo água dos tanques com a presença da microfauna. Os resultados dos experimentos em água de A. fasciata em presença da microfauna apresentaram 45% de mortalidade larval; em água de N. compacta, em presença da microfauna, apresentou inibição de 100% de eclosão de ovos de Ae. aegypti. Há necessidade de informar e educar a população sobre o cultivo de bromélias, sobre a fauna fitotelmata competidora e predadora nos reservatórios e sobre a interação entre aquele ambiente e as larvas do Ae. aegypti. Development, Availability and Mortality of Immature Aedes(Stegomyia aegypti, Linnaeus, in Water of Two Species of Bromeliads: Bibliographic and Experimental Study Abstract. Natural breeding of Aedes aegypti Linnaeus can be found in bromeliads and other plants that have a structure capable of storing water. The productivity of the breeding is linked to the volume and the maintenance of the water content, the nutrients supply, the larval density and the number

  17. Modelo experimental de tumor na cavidade oral de ratos com carcinossarcoma de Walker 256 Experimental model of Walker 256 carcinosarcoma developed in the oral cavity of rats

    Directory of Open Access Journals (Sweden)

    Ana Paula Negreiros Nunes Alves

    2004-08-01

    Full Text Available OBJETIVO: Estabelecer um modelo experimental de desenvolvimento tumoral na cavidade oral de ratos, permitindo, assim, o estudo da osteólise induzida pelo tumor nos ossos do complexo maxilomandibular como também nas estruturas dentais, através da caracterização histomorfológica da reabsorção óssea e dentária. MÉTODOS: Uma suspensão de células tumorais (0,1mL do Carcinossarcoma de Walker 256, na concentração de 10(6 células/mL foi implantado na cavidade alveolar de ratos previamente aberta por exodontia. Os animais foram observados durante 12 (doze dias consecutivos para determinação da curva de peso corpóreo, sendo posteriormente sacrificados e as mandíbulas removidas para exames radiográfico e histológico. RESULTADOS: No exame radiográfico foi verificada área lítica, sem evidência de reparo, na região dos alvéolos. No exame microscópico foi identificada infiltração óssea, periférica e central, de pequenas células hipercromáticas e pleomórficas, com leve infiltrado inflamatório mononuclear associado e áreas de necrose. O índice de pega foi de 100%. CONCLUSÃO: O modelo animal de invasão óssea, do tumor de Walker na cavidade oral, possibilita a avaliação in vivo de drogas antitumorais e esquemas terapêuticos no tratamento do câncer bucal.PURPOSE: To estabilish an experimental model of tumor development in the oral cavity of rats, that would enable to study the tumor-induced autolysis in the maxillomandibular bone complex as well as of the dental structures, through histomorphological characterization of bone and dental resorption. METHODS: Walker 256 carcinossarcoma cell suspension (0,1 mL containing 10(6 cell/mL was implanted in the alveoli of first and second molars. The animals were observed during twelve consecutive days and the body weigth were determined. Later, the animals were sacrificed and their mandibles removed to radiographic and hystologic analysis. RESULTS: The radiographic image

  18. Experimental model of pulmonary carcinogenesis in Wistar rats Modelo experimental de carcinogênese pulmonar em ratos Wistar

    Directory of Open Access Journals (Sweden)

    Baldomero Antonio Kato da Silva

    2007-01-01

    Full Text Available PURPOSE: To elaborate an experimental model of pulmonary carcinogenesis in Wistar rats. METHODS: Male Rattus norvegicus albinus, Wistar lineage was carried through an intra-pulmonary instillation of the Benzo[a]pyrene (B[a]P dilution in alcohol 70%, a polycyclic aromatic hydrocarbon widely known by its power of tumoral induction. Three experimental groups had been formed with 08 animals each: Control Group (Alcohol 70%; B[a]P Group 10 mg/kg; e B[a]P Group 20mg/kg, submitted to euthanasia 08, 10, 12 and 14 weeks after the experimental procedure. The pulmonary sections had been colored by hematoxilin-eosin (HE and submitted to the morphometrical analysis to describe the tissue alterations. RESULTS: The presence of diffuse inflammatory alterations was observed in all groups, however, at the analysis of the pulmonary tissue of the experimental groups, it had been observed hyperplasic alterations (BALT hyperplasia, and in one of the animals of the experimental group 20mg/kg (12 weeks, it was noticed the presence of cellular epithelial tracheal pleomorphism, suggesting the adenocarcinoma formation in situ. CONCLUSION: The main secondary alterations to the intra-pulmonary instillation of B[a]P in Wistar rats were: cellular proliferation, inflammatory alterations of several degrees and nodular lymphoid hyperplasias. The association of an activator agent of the pulmonary metabolic reply is necessary to establish the ideal reply-dose to the development of the lung cancer.OBJETIVO: Elaborar um modelo experimental de carcinogênese pulmonar em ratos wistar. MÉTODOS: Rattus norvegicus albinus, linhagem Wistar foram submetidos a instilação intra-pulmonar da diluição em álcool 70% de Benzo[a]pireno (B[a]P, um hidrocarboneto aromático policíclico amplamente conhecido por seu poder de indução tumoral. Foram formados três grupos experimentais com 08 animais cada: Grupo Controle (álcool 70%; Grupo B[a]P 10 mg/kg; e Grupo B[a]P 20mg/kg, submetidos a

  19. Analytical and experimental study of control effort associated with model reference adaptive control

    Science.gov (United States)

    Messer, R. S.; Haftka, R. T.; Cudney, H. H.

    1992-01-01

    Numerical simulation results presently obtained for the performance of model reference adaptive control (MRAC) are experimentally verified, with a view to accounting for differences between the plant and the reference model after the control function has been brought to bear. MRAC is both experimentally and analytically applied to a single-degree-of-freedom system, as well as analytically to a MIMO system having controlled differences between the reference model and the plant. The control effort is noted to be sensitive to differences between the plant and the reference model.

  20. Experimental evaluation of the use of homogeneous and slip-flow two-phase dynamic models in evaporator modelling

    DEFF Research Database (Denmark)

    Jakobsen, Arne; Antonius, Jesper; Knudsen, Hans Jørgen Høgaard

    1999-01-01

    Distributed dynamic models of a simple coaxial-type evaporator are implemented in the simulation tool Sinda/Fluint. In order to obtain data for model validation an experimental set-up is built, where dynamic responses to changes in inflow and/or outflow of refrigerant are recorded. Model validation...... shows that the dynamic response of the homogeneous model is too fast whereas the simulation results based on the slip-flow model agrees very well with the experimental results. Another difference in the results from the two types of models is the estimation of charge. The charge calculated by the use...... of the homogeneous model is approximately a factor 3 less than the charge calculated using the slip-flow model.The overall conclusion is that when one wants to investigate the dynamic behaviour due to the movement and amount of the refrigerant in the evaporator, then it is needed to use a slip-flow two-phase model...

  1. Immunomodulatory effect of Hawthorn extract in an experimental stroke model.

    Science.gov (United States)

    Elango, Chinnasamy; Devaraj, Sivasithambaram Niranjali

    2010-12-30

    increased Foxp3-positive T(regs) in the brain, which may have aided in suppression of activated inflammatory cells. Such treatment also minimizes apoptotic cell death by influencing STAT-3 phosphorylation and Bcl-xL expression in the brain. Taken together, the immunomodulatory effect of Hawthorn extract may play a critical role in the neuroprotection observed in this MCAO-induced stroke model.

  2. Immunomodulatory effect of Hawthorn extract in an experimental stroke model

    Directory of Open Access Journals (Sweden)

    Devaraj Sivasithambaram

    2010-12-01

    with I/R-induced injury, boosted IL-10 levels, and increased Foxp3-positive Tregs in the brain, which may have aided in suppression of activated inflammatory cells. Such treatment also minimizes apoptotic cell death by influencing STAT-3 phosphorylation and Bcl-xL expression in the brain. Taken together, the immunomodulatory effect of Hawthorn extract may play a critical role in the neuroprotection observed in this MCAO-induced stroke model.

  3. Celiac artery in New Zealand rabbit: anatomical study of its origin and arrangement for experimental research and surgical practice Artéria celíaca em coelhos Nova Zelândia: estudo anatômico de sua origem e arranjo para a pesquisa experimental e a prática cirúrgica

    Directory of Open Access Journals (Sweden)

    Marcelo Abidu-Figueiredo

    2008-05-01

    Full Text Available Rabbits have been used as an experimental model in many diseases and for the study of toxicology, pharmacology and surgery in many universities. However, some aspects of their macro anatomy need a more detailed description, especially the abdominal and pelvic arterial vascular system, which has a huge variability in distribution and trajectory. Thirty cadaveric adult New Zealand rabbits, 13 male and 17 female, with an average weight and rostrum-sacral length of 2.5 kg and 40cm, respectively, were used. The thoracic aorta was cannulated and the vascular system was filled with stained latex S-65. The celiac artery and its proximal branches were dissected and lengthened in order to evidence origin and proximal ramifications. The celiac artery emerged between the 12th and 13th thoracic vertebra in 11 (36.7% rabbits; at the level of the 13th thoracic vertebra in 6 (20% rabbits; between the 13th thoracic vertebra and the 1st lumbar vertebra in 12 (40% rabbits; and at the level of the 1st lumbar vertebra in only one (3.3% rabbit. The mean length of the celiac artery was 0.5cm. The celiac artery first branch was the lienal artery, the second branch was the left gastric artery and the hepatic artery arose from the left gastric artery in all the dissected rabbits. No relation was observed between the celiac artery length and the rostrum-sacral length in rabbits. The number of left gastric and lienal artery branches and the distribution of celiac artery origin are not gender dependent.Os coelhos têm sido usados como modelo experimental em diferentes patologias e para estudos de toxicologia, farmacologia e cirurgia em várias universidades. Entretanto apesar de sua grande utilização, muitos aspectos de sua macroanatomia, em especial os que se referem ao sistema vascular arterial que irrigam as viscerais abdomino-pélvicas ainda carecem de uma descrição mais detalhada, pois os vasos arteriais apresentam grande variabilidade na sua distribuição e

  4. Experimental Modelling of the Breakdown Voltage of Air Using Design of Experiments

    Directory of Open Access Journals (Sweden)

    REZOUGA, M.

    2009-02-01

    Full Text Available Many experimental and numerical studies were devoted to the electric discharge of air, and some mathematical models were proposed for the critical breakdown voltage. As this latter depends on several parameters, it is difficult to find a formula, theoretical or experimental, which considers many factors. The aim of this paper is to model the critical breakdown voltage in a "Sphere-Sphere� electrodes system by using the methodology of experimental designs. Several factors were considered, such as geometrical factors (inter-electrodes interval, diameter of the electrodes and climatic factors (temperature, humidity. Two factorial centred faces experimental designs (CCF were carried out, a first one for the geometrical factors and a second one for the climatic factors. The obtained results made it possible to propose mathematical models and to study the interactions between the various factors.

  5. Removal of Cr(III ions from salt solution by nanofiltration: experimental and modelling analysis

    Directory of Open Access Journals (Sweden)

    Kowalik-Klimczak Anna

    2016-09-01

    Full Text Available The aim of this study was experimental and modelling analysis of the nanofiltration process used for the removal of chromium(III ions from salt solution characterized by low pH. The experimental results were interpreted with Donnan and Steric Partitioning Pore (DSP model based on the extended Nernst-Planck equation. In this model, one of the main parameters, describing retention of ions by the membrane, is pore dielectric