68 research outputs found

    Proton Beam Therapy Versus Conformal Photon Radiation Therapy for Childhood Craniopharyngioma: Multi-institutional Analysis of Outcomes, Cyst Dynamics, and Toxicity

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    PurposeWe compared proton beam therapy (PBT) with intensity modulated radiation therapy (IMRT) for pediatric craniopharyngioma in terms of disease control, cyst dynamics, and toxicity.Methods and MaterialsWe reviewed records from 52 children treated with PBT (n=21) or IMRT (n=31) at 2 institutions from 1996-2012. Endpoints were overall survival (OS), disease control, cyst dynamics, and toxicity.ResultsAt 59.6 months' median follow-up (PBT 33 mo vs IMRT 106 mo; P<.001), the 3-year outcomes were 96% for OS, 95% for nodular failure-free survival and 76% for cystic failure-free survival. Neither OS nor disease control differed between treatment groups (OS P=.742; nodular failure-free survival P=.546; cystic failure-free survival P=.994). During therapy, 40% of patients had cyst growth (20% requiring intervention); immediately after therapy, 17 patients (33%) had cyst growth (transient in 14), more commonly in the IMRT group (42% vs 19% PBT; P=.082); and 27% experienced late cyst growth (32% IMRT, 19% PBT; P=.353), with intervention required in 40%. Toxicity did not differ between groups. On multivariate analysis, cyst growth was related to visual and hypothalamic toxicity (P=.009 and .04, respectively). Patients given radiation as salvage therapy (for recurrence) rather than adjuvant therapy had higher rates of visual and endocrine (P=.017 and .024, respectively) dysfunction.ConclusionsSurvival and disease-control outcomes were equivalent for PBT and IMRT. Cyst growth is common, unpredictable, and should be followed during and after therapy, because it contributes to late toxicity. Delaying radiation therapy until recurrence may result in worse visual and endocrine function

    Assessment of DFG-S19 method for the determination of common endocrine disruptor pesticides in wine samples with an estimation of the uncertainty of the analytical results

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    WOS: 000314193800009PubMed ID: 23265455A gas chromatographic method for the determination of endocrine disruptor pesticides (Chlorpyrifos, Penconazole, Procymidone, Iprodione, Bromopropylate and Lambda-Cyhalothrin) in wine samples is described. A general DFG-S19 method for residual pesticide determination in all kind of food stuff was investigated to simplify and adopt for wine samples in this work. Alternative sample preparation routes were elucidated and compared according to their recovery values. Four different separation techniques were tested and the method employing florosil column after a LLE procedure was applied for wine samples with satisfactory recovery ratios (72-97%). The pesticides were extracted from the sample by cyclohexane-ethyl acetate mixture (1:1 v/v) and cleaned up by florosil column. The regression coefficients were at least 0.99 and relative standard deviations were no higher than 16%. Detection limits were in the range of 0.6-2.9 ng/mL and the relative expanded measurement uncertainties were calculated in the 7-22% range. (C) 2012 Elsevier Ltd. All rights reserved.Ege UniversityEge University [2005/Fen/017]; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [108T660]The authors thank to the Ege University for financial support (Project 2005/Fen/017) and TUBITAK ((Project 108T660)

    A spectrophotometric method for determination of molybdenum in water samples by using pyrogallol red and a water soluble ionic liquid

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    WOS: 000324927300061The present study describes a simple and sensitive spectrophotometric method for the determination of molybdenum in real water samples. The method is based on the hyperchromic and bathochromic effect of an ionic liquid namely, 1-methyl-3-octadecyl-imidazolium bromide (C(18)mimBr), on molybdenum ion (Mo(VI)) and pyrogallol red (PGR) complex. The ternary complex of Mo-PGR-C(18)mimBr displays a distinct absorption peak with excellent analytical characteristics and offers the advantages of simplicity for the determination of Mo(VI) ions, without any need for a solvent extraction step. The limit of detection (LOD) and limit of quantification (LOQ) of the method were calculated as 0.74 ng mL(-1) and 2.47 ng mL(-1) respectively. The method was validated and applied successfully to the determination of Mo(VI) ions in real water samples. The interference of ferric ions was shown to be removed from samples with less ionic content by using an ion exchange resin prior to the analysis, and the performance of the method was compared with that of ICP-MS.Ege UniversityEge UniversityAuthors thank Ege University for financial support and Ege University, Centre for R&D and Pharmacokinetic Applications Environmental & Food Analysis Laboratory (ARGEFAR) for ICP-MS measurements. Authors would like to thank Ass. Prof. Armagan Kinal for proof reading

    Ionic liquid intercalated clay sorbents for micro solid phase extraction of steroid hormones from water samples with analysis by liquid chromatography-tandem mass spectrometry

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    WOS: 000342257200006PubMed ID: 25130089Clay material plays an important role in the transport and retention of many compounds in the soil, therefore, clay based sorbents are promising alternatives for selective sorption of organic pollutants. In the present work, different chain length ionic liquids (ILs) namely, 1-methyl-3-octyl-imidazolium bromide, 1-methyl-3-undecyl-imidazolium bromide and 1-methyl-3-octadecyl-imidazolium bromide were intercalated in the galleries of montmorillonite (MMT) clay. Then, this novel nanofiller surface was utilized in micro extraction of estrogenic hormones for the first time. A fast procedure where sonication-assisted emulsification microextraction combined with vortex assisted micro-solid phase extraction (mu-SPE) was developed for the LC-MS/MS analysis of estrone (E1), 17 beta-estradiol (E2), estriol (E3) and ethynylestradiol (EE2). The parameters related to the mu-SPE procedure namely; pH, sorbent amount, extraction solvent type and volume, sonication and vortex time, sample volume and salt effect on the extraction efficiency were screened by applying Plackett-Burmann design. The selected parameters were then optimized by using Box-Behnken design. The method was validated for the determination of estrogenic hormone residues in river water samples. Linear calibration plots were obtained for all hormones whose regression coefficients were larger than 0.98. RSD values were found less than 10% for three levels of concentration. LOD levels were calculated as; 0.012, 0.062, 0.018 and 0.693 ng L-1 for E1, E2, E3 and EE2, respectively. Recovery values were calculated in the range of 86.9-97.7%. Considering large sample volumes required for attaining low limits of these hormones, present method provides an ease for analyst as 10 mL of the sample is adequate for achieving the same sensitivity. (C) 2014 Elsevier B.V. All rights reserved.Ege UniversityEge University [2012/Fen/046]The authors thank to the Ege University (Project no: 2012/Fen/046) for financial support

    Preparation and characterization of sodium dodecyl sulfate doped polypyrrole solid phase micro extraction fiber and its application to endocrine disruptor pesticide analysis

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    WOS: 000320085300015PubMed ID: 23669608A robust in house solid-phase micro extraction (SPME) surface has been developed for the headspace (HS)-SPME determination of endocrine disruptor pesticides, namely, Chlorpyrifos, Penconazole, Procymidone, Bromopropylate and Lambda-Cyhalothrin in wine sample by using sodium dodecylsulfate doped polypyrrole SPME fiber. Pyrrole monomer was electrochemically polymerized on a stainless steel wire in laboratory conditions in virtue of diminishing the cost and enhancing the analyte retention on its surface to exert better selectivity and hence the developed polymerized surface could offer to analyst to exploit it as a fiber in headspace SPME analysis. The parameters, mainly, adsorption temperature and time, desorption temperature, stirring rate and salt amount were optimized to be as 70 degrees C and 45 min, 200 degrees C, 600 rpm and 10 g L-1, respectively. Limit of detection was estimated in the range of 0.073-1.659 ng mL(-1) for the pesticides studied. The developed method was applied in to red wine sample with acceptable recovery values (92-107%) which were obtained for these selected pesticides. (C) 2013 Elsevier B.V. All rights reserved.Ege UniversityEge University [2010/Fen/033]The authors thank to the Ege University for financial support (Project 2010/Fen/033)

    Preparation and Characterization of a Novel Solid-Phase Microextraction Material for Application to the Determination of Pesticides

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    9th Aegean Analytical Chemistry Days (AACD) -- SEP 29-OCT 03, 2014 -- Chios, GREECEWOS: 000373911300004The preparation and characterization of a novel solid-phase microextraction fiber is reported with application to the determination of pesticides in fruit juice. The fiber was fabricated by electrochemically coating a stainless steel wire with a thin polymeric film of 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl) benzenamine. The procedure was initiated in 10mL of acetonitrile containing 5.5mg of monomer, 0.1mol NaClO4, and 0.1mol LiClO4 by cycling the potential between -0.5 and 1.2V with a scan rate of 100mV/sec. The morphology of the fiber surface was examined by scanning electron microscopy and its stability was characterized by thermal gravimetric analysis. The fiber was exposed to headspace extraction of bromopropylate, chlorpyrifos, lambda-cyhalothrin, penconazole, and procymidone prior to the analysis by gas chromatography with an electron capture detector. Operational parameters affecting the extraction efficiency, adsorption and desorption times and temperature, and stirring rate were screened using a Plackett-Burman Design. Emerging parameters were further optimized via Central Composite Design that were 20min at 64 degrees C for adsorption and 4.4min at 250 degrees C for desorption. Solution parameters were optimized to be 5.0mL of sample in pH 2.0 Britton-Robinson buffer containing 0.1mg/L NaCl to promote the volatilization of the analytes. The limits of detection were at the ng/mL level for the pesticides. The fiber was used as a selective and sensitive tool for the trace determination of these pesticides in grape juice
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