278 research outputs found

    Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth

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    Retinopathy of prematurity (ROP) is one of the main blinding diseases affecting preterm newborns and is classically considered a vascular disorder. The premature exposure to the extrauterine environment, which is hyperoxic in respect to the intrauterine environment, triggers a cascade of events leading to retinal ischemia which, in turn, makes the retina hypoxic thus setting off angiogenic processes. However, many children with a history of ROP show persistent vision impairment, and there is evidence of an association between ROP and neurosensory disabilities. This is not surprising given the strict relationship between neuronal function and an adequate blood supply. In the present work, we revised literature data evidencing to what extent ROP can be considered a neurodegenerative disease, also taking advantage from data obtained in preclinical models of ROP. The involvement of different retinal cell populations in triggering the neuronal damage in ROP was described along with the neurological outcomes associated to ROP. The situation of ROP in Italy was assessed as well

    Transposition of the apophysis of the greater trochanter for reconstruction of the femoral head after septic hip arthritis in children: 4 children followed for more than 15 years

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    Background and purpose Total necrosis of the femoral head after infection in children during their first months of life gives a dislocated hip with severe leg shortening. A new femoral head can be achieved with subtrochanteric osteotomy and transposition of the apophysis of the greater trochanter into the acetabulum. Previous reports have dealt with short-term results (up to 12 years). Here I present some results of this procedure 15–24 years after operation. Patients and methods 4 children aged 1–6 years with complete necrosis of the femoral head were operated on with transposition of the greater trochanter. Secondary shelf plasty was performed later in 1 child, distal femoral epiphysiodesis in another, and femoral bone lengthening in 1 child. The mean follow-up period was 19 (15–24) years. Results A new femoral head developed in all hips. 2 of them had a spherical head with a good acetabular cover, and without any osteoarthritis except for slight reduction of cartilage height. These hips were painless, with a mobility that allowed good walking function after 16 and 24 years, respectively. In the other 2 patients, in which there was a severe acetabular dysplasia at the primary operation, the new femoral head was somewhat flattened; painful osteoarthritis led to hip replacement 15 and 21 years after trochanter arthroplasty. Even these patients had a relatively good walking function until the last couple of years before hip replacement. Maximum leg length discrepancy was 7 cm. Interpretation Trochanter arthroplasty with subtrochanteric osteotomy in total femoral head necrosis after septic arthritis in children may give satisfactory long-term results provided adequate acetabular cover is obtained. Although the method cannot provide a normal hip, it can contribute to less length discrepancy, less pain, improved gait, and more favorable conditions for later hip replacement

    Mensuração dos custos e avaliação de rendas em sistemas de produção de leite caprino nos Cariris Paraibanos.

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    Resumo: Objetivou-se mensurar o custo de produção do leite e avaliar a renda na atividade caprina por sistemas de produção. Os sistemas de produção estão localizados na microrregião dos Cariris Paraibanos e foram definidos por critérios de eficiência técnica e econômica, com método de agrupamento por análise multivariada e formação de cinco grupos. O método utilizado para o custo de produção foi o custo operacional, e o critério adotado para a conversão do custo da atividade leiteira para o custo do leite foi da participação da renda do leite na renda bruta da atividade. Os critérios adotados de análise de rendas foram margem bruta e margem líquida. No cômputo do custo de produção do leite de cabra, os valores foram de R0,67/L;R 0,67/L; R 0,73/L; R0,80/L;R 0,80/L; R 0,88/L; e R1,21/Lparaossistemasdeproduc\ca~o1,2,3,4e5.Ossistemasdeproduc\ca~o1e2,dealtatecnologia,commargemlıˊquidadeR 1,21/L para os sistemas de produção 1, 2, 3, 4 e 5. Os sistemas de produção 1 e 2, de alta tecnologia, com margem líquida de R 9.147,30 e R3.995,18naatividadeleiteira,foramosqueapresentaramosmenorescustoseeconomicamentesa~oosmaisvantajosos.[CalculationofthecostsandevaluationofincomesindifferentsystemsofproductionofgoatmilkinCaririsParaibanos].Abstract:Thestudyaimedatcalculatingmilkproductioncostandevaluatingtheincomeingoatmilkfarmactivitybyproductionsystems.TheproductionsystemsarelocatedinthesubregionofCaririsParaibanosandtheyweredefinedbycriteriaoftechnicalandeconomicalefficiency,withgroupingmethodbymultivariatedataanalysisandformationoffivegroups.Themethodusedforproductioncostwastheoperationalcost,andthecriterionadoptedfortheconversionofthemilkactivitycostforthecostofthemilkwastheparticipationofthemilkincomeinthegrossincomeoftheactivity.Thecriteriaadoptedforanalysisofincomeweregrossmarginandnetmargin.InthecountofgoatmilkproductioncostthevalueswereR 3.995,18 na atividade leiteira, foram os que apresentaram os menores custos e economicamente são os mais vantajosos. [Calculation of the costs and evaluation of incomes in different systems of production of goat milk in Cariris Paraibanos]. Abstract: The study aimed at calculating milk production cost and evaluating the income in goat milk farm activity by production systems. The production systems are located in the sub region of Cariris Paraibanos and they were defined by criteria of technical and economical efficiency, with grouping method by multivariate data analysis and formation of five groups. The method used for production cost was the operational cost, and the criterion adopted for the conversion of the milk activity cost for the cost of the milk was the participation of the milk income in the gross income of the activity. The criteria adopted for analysis of income were gross margin and net margin. In the count of goat milk production cost the values were R 0.67/L R0.73/L,R 0.73/L, R 0.80/L, R0.88/LandR 0.88/L and R 1.21/L for the production systems 1, 2, 3, 4 and 5. Systems of production 1 and 2 with high technology and net margin of R9,147.30andR 9,147.30 and R 3,995.18 in the milk activity, were the ones that showed the lowest costs and they are economically the most advantageou

    Refractive outcome in preterm newborns with ROP after propranolol treatment. A retrospective observational cohort study

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    Background: Recent explorative studies suggest that propranolol reduces retinopathy of prematurity (ROP) progression, but the short-term effects of propranolol treatment at 1 year of corrected age have not been extensively evaluated. Methods: A multi-center retrospective observational cohort study was conducted to assess the physical development and the refractive outcome of infants with prior ROP treated with propranolol. Forty-nine infants treated with propranolol were compared with an equal number of patients who did not receive any propranolol therapy and represent the control group, with comparable anthropometrical characteristics and stages of ROP. Results: The weight, length, and head circumference at 1 year of corrected age were similar between infants who had been treated, or not, with propranolol, without any statistically significant differences. Refractive evaluation at 1 year showed spherical equivalent values decreasing with the progression of ROP toward more severe stages of the disease, together with an increasing number of infants with severe myopia. On the contrary, no differences were observed between infants who had been treated with propranolol and those who had not. Conclusion: This study confirms that the progression of ROP induces an increase of refractive errors and suggests that propranolol itself does not affect the refractive outcome. Therefore, if the efficacy of propranolol in counteracting ROP progression is confirmed by further clinical trials, the conclusion will be that propranolol might indirectly improve the visual outcome, reducing the progression of ROP

    Spatio-temporal dynamics of quantum-well excitons

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    We investigate the lateral transport of excitons in ZnSe quantum wells by using time-resolved micro-photoluminescence enhanced by the introduction of a solid immersion lens. The spatial and temporal resolutions are 200 nm and 5 ps, respectively. Strong deviation from classical diffusion is observed up to 400 ps. This feature is attributed to the hot-exciton effects, consistent with previous experiments under cw excitation. The coupled transport-relaxation process of hot excitons is modelled by Monte Carlo simulation. We prove that two basic assumptions typically accepted in photoluminescence investigations on excitonic transport, namely (i) the classical diffusion model as well as (ii) the equivalence between the temporal and spatial evolution of the exciton population and of the measured photoluminescence, are not valid for low-temperature experiments.Comment: 8 pages, 6 figure
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