124 research outputs found

    Relationship between survival and increased radiation dose to subventricular zone in glioblastoma is controversial.

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    To test the hypothesis on prolonged survival in glioblastoma cases with increased subventricular zone (SVZ) radiation dose. Sixty glioblastoma cases were previously treated with adjuvant radiotherapy and Temozolamide. Ipsilateral, contralateral and bilateral SVZs were contoured and their doses were retrospectively evaluated. Median follow-up, progression free survival (PFS) and overall survival (OS) were 24.5, 8.5 and 19.3 months respectively. Log-rank tests showed a statistically significant correlation between contralateral SVZ (cSVZ) dose > 59.2 Gy (75th percentile) and poor median PFS (10.37 [95% CI 8.37-13.53] vs 7.1 [95% CI 3.5-8.97] months, p = 0.009). cSVZ dose > 59.2 Gy was associated with poor OS in the subgroup with subtotal resection/biopsy (HR: 4.83 [95% CI 1.71-13.97], p = 0.004). High ipsilateral SVZ dose of > 62.25 Gy (75th percentile) was associated with poor PFS in both subgroups of high performance status (HR: 2.58 [95% CI 1.03-6.05], p = 0.044) and SVZ without tumoral contact (HR: 10.57 [95% CI 2.04-49], p = 0.008). The effect of high cSVZ dose on PFS lost its statistical significance in multivariate Cox regression analysis. We report contradictory results compared to previous publications. Changing the clinical practice based on retrospective studies which even do not indicate consistent results among each other will be dangerous. We need carefully designed prospective randomized studies to evaluate any impact of radiation to SVZ in glioblastoma

    Prevention of Pleural Adhesions Using a Membrane Containing Polyethylene Glycol in Rats

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    Background: Recurrent thoracotomies regardless of the cause are not a rare occurrence. However, each thoracotomy results in adhesion to some extent. This adhesions increase morbidity and mortality presents a significant inconvenience for surgeons and prolongs the length of operations

    ‘More than Just Waste Paper’ – It Could Be an Indicator of a Stereotypical Image of a Scientist

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    The purpose of this study was to investigate the meanings assigned by pre-service teachers to the wastepaper basket and waste (crumpled) papers in their drawings of a scientist. The study was carried out with 220 pre-service teachers during the 2015-2016 academic years. A phenomenological research method was used. First, the pre-service teachers were administered the ‘Draw-A-Scientist Test’ in order to identify their images of a scientist and then they were asked to describe and explain the scientist they drew. And a semi-structured interview was performed with the 34 pre-service teachers who included a wastepaper basket and waste paper in their drawings in order to identify the meanings assigned to the wastepaper and wastepaper basket by these teachers. The data were analysed by using content analysis. The results of the analysis showed that with these figures the pre-service teachers revealed their belief that when scientists conduct research, they follow a confirmatory experimental process in a similar manner to the way school science experiments. Based on these results, it can be suggested in the analysis of the drawings that waste paper and wastepaper baskets can be regarded as indicators of the stereotypical image of scientists and of the scientific method they use

    Relationship between survival and increased radiation dose to subventricular zone in glioblastoma is controversial

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    To test the hypothesis on prolonged survival in glioblastoma cases with increased subventricular zone (SVZ) radiation dose. Sixty glioblastoma cases were previously treated with adjuvant radiotherapy and Temozolamide. Ipsilateral, contralateral and bilateral SVZs were contoured and their doses were retrospectively evaluated. Median follow-up, progression free survival (PFS) and overall survival (OS) were 24.5, 8.5 and 19.3months respectively. Log-rank tests showed a statistically significant correlation between contralateral SVZ (cSVZ) dose >59.2Gy (75th percentile) and poor median PFS (10.37 [95% CI 8.37-13.53] vs 7.1 [95% CI 3.5-8.97] months, p=0.009). cSVZ dose>59.2Gy was associated with poor OS in the subgroup with subtotal resection/biopsy (HR: 4.83 [95% CI 1.71-13.97], p=0.004). High ipsilateral SVZ dose of >62.25Gy (75th percentile) was associated with poor PFS in both subgroups of high performance status (HR: 2.58 [95% CI 1.03-6.05], p=0.044) and SVZ without tumoral contact (HR: 10.57 [95% CI 2.04-49], p=0.008). The effect of high cSVZ dose on PFS lost its statistical significance in multivariate Cox regression analysis. We report contradictory results compared to previous publications. Changing the clinical practice based on retrospective studies which even do not indicate consistent results among each other will be dangerous. We need carefully designed prospective randomized studies to evaluate any impact of radiation to SVZ in glioblastoma

    Synthesis of Symmetrical Urea Derivatives From CO2 and Amines Over Copper-Based Core-Shell Catalysts

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    Urea derivatives are key intermediates in the synthesis of agrochemicals and pharmaceuticals and also have applications as additives in fuels and polymers. Traditional production routes require the use of highly toxic chemicals such as phosgene, isocyanates and carbon monoxide. Carbon dioxide is emerging as an alternative feedstock for the production of urea derivatives, avoiding the use of such hazardous materials. Previous studies, however, employed catalysts based on rare and expensive metals for long reaction times of up to 48 h. This work presented here shows the successful synthesis of urea derivatives from CO2 and various amines using inexpensive and abundant copper and iron-based catalysts with reduced reaction times
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