8 research outputs found

    Poly(amidoxime) ligand derived from waste palm fiber for the removal of heavy metals from electroplating wastewater

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    A waste material known as palm oil empty fruit bunch (EFB) is used as a source of cellulose for the development of polymeric materials for the removal of metal ions from industrial wastewater. A poly(acrylonitrile)-grafted palm cellulose copolymer was synthesized by a conventional free radical initiating process followed by synthesis of a poly(amidoxime) ligand by oximation reaction. The resulting products were characterized by FT-IR, FE-SEM, EDX, TGA, DSC, and XPS. The poly(amidoxime) ligand was used to coordinate with and extract a series of transition metal ions from water samples. The binding capacity (qe) of the ligand with the metal ions such as copper, iron, cobalt, nickel, and lead were 260, 210, 168, 172, and 272 mg g−1 , respectively at pH 6. The adsorption process followed the pseudo-first-order kinetic model (R2 > 0.99) and as well as the Freundlich isotherm model (R2 > 0.99) indicating the occurrence of a multi-layer adsorption process in the amidoxime ligand adsorbent. Results from reusability studies show that the ligand can be recycled for at least 10 cycles without any significant losses to its initial adsorption capacity. The synthesized polymeric ligand was shown to absorb heavy metals from electroplating wastewater with up to 95% efficiency

    The influence of poly (2-methoxyaniline-5-sulfonic acid) on the electrochemical and photochemical properties of a highly luminescent ruthenium complex

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    Immobilisation of a luminescent material on an electrode surface is well known to substantially modulate its photophysical and electrochemical properties. Here a positively charged ruthenium metal complex ([Ru(bpy)(3)](2+)) is immobilised on all electrode surface by ion paring with a sulfonated conducting polymer poly(2-methoxyaniline-5-sulfonic acid), (PMAS). Significantly, our study reveals that the electron transport between the ruthenium metal centres can be greatly enhanced due to the interaction with the conducting polymer when both are surface confined. Charge transfer diffusion rates in the present system are an order of magnitude faster than those found where the metal centre is immobilised within a non-conducting polymeric matrix. Electron transport appears to be mediated through the PMAS conjugated structure, contrasting with the electron hopping process typically observed in non-conducting metallopolymers. This increased regeneration rate causes the ruthenium-based electrochemiluminescence (ECL) efficiency to be increased. The impact of these observations on the ECL detection of low concentrations of disease biomarkers is discussed. (c) 2007 Published by Elsevier Ltd

    The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

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    Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

    Second‐line chemotherapy in advanced biliary cancers: A retrospective, multicenter analysis of outcomes

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    BACKGROUND: Though gemcitabine plus platinum chemotherapy is the established first line regimen for advanced biliary tract cancer (ABC), there is no standard second line therapy. We evaluated current practice and outcomes for second line chemotherapy in patients with ABC across three US academic medical centers. METHODS: Institutional registries were reviewed to identify patients who had received second line chemotherapy for ABC from 4/2010 to 3/2015, along with demographics, diagnosis and staging, treatment history, and clinical outcomes. Overall survival from initiation of second line chemotherapy (OS2) was estimated using Kaplan-Meier methods. RESULTS: We identified 198 patients with cholangiocarcinoma (intrahepatic, 61.1% and extrahepatic, 14.1%) and gallbladder carcinoma (24.8%); 52% received at least 3 lines of systemic chemotherapy. The median OS2 11 months (95% CI 8.8-13.1). Median OS2 for intrahepatic cholangiocarcinoma was 13.4 months (95% CI: 10.7-17.8), longer than extrahepatic or gallbladder with mOS2 of 6.8 months (95% CI: 5-10.5) and 9.4 months (95% CI: 7.2-12.3), respectively (p=0.018). The median time to second line treatment failure was 2.2 (95% CI: 1.8-2.7) months, similar across tumor locations (p=0.60). CONCLUSIONS: In this large cohort of ABC patients treated across three academic medical centers after failure of first line chemotherapy, the time to treatment failure on standard therapies was short, though median OS2 was longer than has been reported previously, and over half of patients received additional lines of treatment. This multicenter collaboration represents the largest cohort studied to date of second line chemotherapy in ABC and provides a contemporary benchmark for future clinical trials
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