H? filtering of time-varying systems with bounded rates of variation

In this paper, the problem of robust filter design for time-varying discrete-time polytopic systems with bounded rates of variation is investigated. The design conditions are obtained by using a parameter-dependent Lyapunov function and the Finsler\u27s Lemma. A robust filter, that minimizes an upper bound to the H? performance of the estimation error, is obtained as the solution of an optimization problem. A more precise geometric representation of the parameter time variation was used in order to obtain less conservative design conditions. Robust filters for time-invariant, as well as arbitrarily time-varying, polytopic systems can be obtained as a particular case of the proposed method. Numerical examples illustrate the results

H? robust memory controllers for networked control systems: uncertain sampling rates and time delays in polytopic domains

In this paper, the problem of controller design for networked control systems with time-varying sampling rates and time delays is investigated. By using a memory at the feedback loop, a digital robust controller that minimizes an upper bound to the Hinfin performance of the closed loop system is determined. The design conditions are obtained from the Finsler\u27s Lemma combined with the Lyapunov theory and expressed in terms of bilinear matrix inequalities. Extra variables introduced by the Finsler\u27s Lemma are explored in order to provide a better system behavior. The time-varying uncertainties are modelled using polytopic domains. The controller is obtained by the solution of an optimization problem formulated only in terms of the vertices of the polytope, avoiding grids in the parametric space. Numerical examples illustrate the efficiency of the proposed approach

H? Gain Scheduling for Discrete-Time Systems with Control Delays and Time-Varying Parameters: a BMI Approach

In this paper, the problem of gain scheduling for time-varying systems with time delays is investigated. By using a memory at the feedback loop, a discrete gain scheduled controller which minimizes an upper bound to the ,Hscrinfin performance of the closed loop system is determined. The design conditions, expressed in terms of bilinear matrix inequalities, are obtained from the Finsler\u27s Lemma combined with the Lyapunov theory. The extra variables introduced by the Finsler\u27s Lemma represent an alternative way in the search of better system behavior. The time-varying uncertainties are modeled using polytopic domains. The controller is obtained by the solution of an optimization problem formulated only in terms of the vertices of the polytope. No grids in the parametric space are used. Numerical examples illustrate the efficiency of the proposed approach

Oral glucose for pain relief during examination for retinopathy of prematurity: a masked randomized clinical trial

OBJECTIVE: Ophthalmologic examination for retinopathy of prematurity is a painful procedure. Pharmacological and non-pharmacological interventions have been proposed to reduce pain during eye examinations. This study aims to evaluate the analgesic effect of 25% glucose using a validated pain scale during the first eye examination for retinopathy of prematurity in preterm infants with birth weigh

Is being small for gestational age a risk factor for retinopathy of prematurity? A study with 345 very low birth weight preterm infants

OBJECTIVE: To analyze prevalence and risk factors for retinopathy of prematurity (ROP) among preterm infants born small for gestational age (SGA) and appropriate for gestational age (AGA). METHODS: A prospective cohort study included preterm infants with birth weight (BW) ≤ 1,500 grams and gestational age (GA) ≤ 32 weeks, divided into two groups: AGA or SGA. Prevalences and risk factors for ROP were determined in both groups. Logistic regression was used for the significant variables after univariate analysis. RESULTS: A total of 345 patients were examined: 199 included in the AGA group and 146 in the SGA. Mean BW and GA in the whole cohort (345 patients) were 1,128.12 grams (±239.9) and 29.7 weeks (±1.9), respectively. The prevalence of any stage ROP and severe ROP (needing treatment) was 29.6 and 7.0%, respectively. ROP in any evolutive stage developed in 66 AGA (33.2%) and in 36 SGA (24.7%) (p = 0.111). Severe ROP occurred in 15 AGA (7.5%) and in nine SGA (6.2%) (p = 0.779). After adjusted logistic regression, weight gain from birth to sixth week of life and need for blood transfusions were found to be significant risk factors for ROP in both groups. CONCLUSIONS: This study has shown that being SGA was not a significant risk factor for any stage ROP or for severe ROP in this cohort and, also, that the risk factors for ROP were similar among SGA and AGA very-low-birth-weight preterm babies.OBJETIVO: Comparar a prevalência e os fatores de risco para a retinopatia da prematuridade entre pré-termos pequenos para a idade gestacional e pré-termos apropriados para a idade gestacional. MÉTODOS: Estudo de coorte, prospectivo, incluindo pré-termos com peso de nascimento ≤ 1.500 g e idade gestacional ≤ 32 semanas divididos em dois grupos: apropriados para a idade gestacional ou pequenos para a idade gestacional. As prevalências da retinopatia da prematuridade e os fatores de risco foram estudados nos dois grupos. Regressão logística foi utilizada após análise univariada. RESULTADOS: Foram examinados um total de 345 pacientes: 199 no grupo apropriados para a idade gestacional e 146 no grupo pequenos para a idade gestacional. As médias do peso de nascimento e da idade gestacional na coorte de 345 pacientes foram 1.128,12 g (±239,9) e 29,7 semanas (±1,9), respectivamente. A prevalência da retinopatia da prematuridade em qualquer estadiamento e da retinopatia da prematuridade severa (necessitando tratamento) foi 29,6 e 7%, respectivamente. A retinopatia da prematuridade em qualquer estadiamento ocorreu em 66 apropriados para a idade gestacional (33,2%) e em 36 pequenos para a idade gestacional (24,7%) (p = 0,111). A retinopatia da prematuridade severa ocorreu em 15 apropriados para a idade gestacional (7,5%) e em nove pequenos para a idade gestacional (6,2%) (p = 0,779). Após regressão logística ajustada, o ganho ponderal do nascimento até a sexta semana de vida e a necessidade de transfusões sanguíneas foram fatores de risco significativos para a retinopatia da prematuridade nos dois grupos. CONCLUSÕES: Este estudo mostrou que ser pequenos para a idade gestacional não foi um fator de risco significativo para o surgimento da retinopatia da prematuridade e que os fatores de risco para a retinopatia da prematuridade são semelhantes em pré-termos pequenos para a idade gestacional e apropriados para a idade gestacional.Universidade Federal do Rio Grande do Sul Faculdade de MedicinaHospital de Clínicas de Porto Alegre Setor de Retinopatia da PrematuridadeUFRGSHCPAUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaHCPA Unidade de Terapia Intensiva NeonatalUFRGS Faculdade de MedicinaHCPA Serviço de NeonatologiaUNIFESP, EPMSciEL

Descrição morfoquantitativa do tórus digital de bovinos

O tórus digital é caracterizado como um tecido subcutâneo modificado que atua na absorção do impacto durante a locomoção, auxilia o retorno venoso do casco e mantêm o suporte de uma considerável parte do peso corporal. Os tórus possuem particular importância nas patogêneses de casco, já que eles precisam trabalhar corretamente para prevenir compressões e traumas nos tecidos moles. Assim, o objetivo deste estudo foi quantificar e com isso determinar, como se arranjam estas estruturas, para tanto, foram estabelecidas as proporções dos tecidos conjuntivo, adiposo, vascular e ainda das fibras colágenas e dos tipos de colágenos encontrados nos tórus digitais palmares e plantares de bovinos. Foram utilizados membros torácicos e pélvicos de doze bovinos zebuínos adultos, de ambos os sexos, sendo onze machos e uma fêmea, com peso médio de carcaça com 269kg e sem afecções nos membros. Os fragmentos dos tórus foram submetidos à técnica histológica convencional, cortados em espessura de 4µm e corados com Picrosirius Red. Com o uso de microscópio óptico digital, o tecido conjuntivo e a diferenciação dos tipos de colágeno foram quantificados empregando-se o programa de análise de imagem Image Pro Plus® e para a quantificação dos tecidos adiposo e vascular foi utilizada o sistema teste de pontos. Através do programa GraphPad Prism 5.0 foram obtidas por meio de uma analise descritiva a media e o erro padrão da media, em seguida os dados foram submetidos à aplicação do teste de normalidade de Kolmogorov-Smirnov e ao teste "T" Student com nível de significância de 5% para a determinação da quantidade encontrada dos diferentes tecidos entre os membros torácicos e pélvicos dos animais estudados. Nos membros torácicos a média e o erro padrão da proporção de tecido conjuntivo foi de 50,10%+1,54, a de tecido adiposo foi de 21,34%+1,44 e a de tecido vascular foi de 3,43%+0,28. Os membros pélvicos apresentaram uma proporção de tecido conjuntivo de 61,61%+1,47, de tecido adiposo de 20,66%+1,53 e de tecido vascular de 3,06%+0,20. Verificou-se diferença estatística na proporção de tecido conjuntivo entre membros torácicos e pélvicos (p<0,001). As fibras colágenas tipo I e III apresentaram, respectivamente, uma proporção de 31,89% e 3,9% nos membros torácicos e 34,05% e 1,78% nos membros pélvicos. Os tórus digitais, de acordo com a metodologia utilizada, apresentaram diferenciação evidente em relação ao tecido adiposo entre membros torácicos e pélvicos.The digital cushion is characterized as a modified subcutaneous tissue that absorbs the shock during gait, assists venous return of the hoof and supports a considerable part of body weight. Digital cushions have particular importance in the pathogenesis of the hoof, since they need to properly work in order to prevent compression and traumas in soft tissues. This study aimed to measure and determine how is the arrangement of these structures, and for this it was established the proportions of connective, adipose, vascular tissues and collagen fibers and collagen types found in palmar and plantar digital cushion of bovine using fore and hindlimbs of twelve adult zebu cattle of both sexes, 11 male and one female, with 269kg average carcass weight and without limb disorders. Fragments of cushions were subjected to conventional histology, cut to a thickness of 4µm and stained with Red Picrosirius. With digital optical microscope, the quantification of the connective tissue and differentiation of types of collagen used the Image Pro Plus® software, and of adipose and vascular tissue, the test point system. The mean and standard error were estimated with the GraphPad Prism 5.0 software, and then data were subjected to Kolmogorov-Smirnov normality test and Student's t-test with significance level set at 5% for determining the amount of different tissues between fore and hindlimbs of studied animals. In forelimbs the mean and standard error of the connective tissue proportion was 50.10%+1.54, of the adipose tissue was 21.34%+1.44, and of vascular tissue was 3.43%+0.28. Hindlimbs presented a proportion of connective tissue of 61.61%+1.47, 20.66%+1.53 of adipose tissue, and 3.06%+0.20 of vascular tissue. A significant difference (p<0.001) was detected in the connective tissue proportion between fore and hindlimbs. Types I and II collagen fibers have presented, respectively, a proportion of 31.89% and 3.9% in forelimbs and 34.05% and 1.78% in hindlimbs. According to the used methodology, digital cushions had a clear differentiation relative to adipose tissue between fore and hindlimbs

Stanniocalcin 2 contributes to aggressiveness and is a prognostic marker for oral squamous cell carcinoma

Stanniocalcin 2 (STC2), a glycoprotein that regulates calcium and phosphate homeostasis during mineral metabolism, appears to display multiple roles in tumorigenesis and cancer progression. This study aimed to access the prognostic value of STC2 in oral squamous cell carcinoma (OSCC) and its implications in oral tumorigenesis. STC2 expression was examined in 2 independent cohorts of OSCC tissues by immunohistochemistry. A loss-of-function strategy using shRNA targeting STC2 was employed to investigate STC2 in vitro effects on proliferation, apoptosis, migration, invasion, epithelial-mesenchymal transition (EMT) and possible activation of signaling pathways. Moreover, STC2 effects were assessed in vivo in a xenograft mouse cancer model. High expression of STC2 was significantly associated with poor disease-specific survival (HR: 2.67, 95% CI: 1.37-5.21, p = 0.001) and high rate of recurrence with a hazard ratio of 2.80 (95% CI: 1.07-5.71, p = 0.03). In vitro downregulation of STC2 expression in OSCC cells attenuated proliferation, migration and invasiveness while increased apoptotic rates. In addition, the STC2 downregulation controlled EMT phenotype of OSCC cells, with regulation on E-cadherin, vimentin, Snaill, Twist and Zeb2. The reactivation of STC2 was observed in the STC2 knockdown cells in the in vivo xenograft model, and no influence on tumor growth was observed. Modulation of STC2 expression levels did not alter consistently the phosphorylation status of CREB, ERK, JNK, p38, p70 S6K, STAT3, STAT5A/B and AKT. Our findings suggest that STC2 overexpression is an independent marker of OSCC outcome and may contribute to tumor progression via regulation of proliferation, survival and invasiveness of OSCC cells.Peer reviewe