146 research outputs found

    Continuous process for selective metal extraction with an ionic liquid

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    This work describes for the first time a continuous process for selective metal extraction with an ionic liquid (IL) at room temperature. The hydrophobic fatty acid based IL tetraoctylphosphonium oleate ([P-8888][oleate]) was specifically chosen for its low viscosity and high selectivity towards transition metals. Applying [P-8888][oleate] for continuous metal ion extraction with 0.1 M sodium oxalate for regeneration resulted in a process with good and stable extraction efficiencies over time. The selectivity of the IL resulted in a process in which cobalt was selectively removed from two mixed salt solutions (Co/Na, Ca/Co/K) to obtain a pure cobalt stream after stripping the IL. The performed experiments showed that the contact time of the IL for extraction and stripping strongly influenced the achieved efficiencies. The stability of the IL was tested and it was shown that the fatty acid based IL was stable for the duration of the experiment. Liposome tests showed that the IL is very hydrophobic, which limits its leakage towards the water phase, but also results in a higher toxicity towards cell membranes. Economic analysis shows that the IL based process is not (yet) economical compared to ion-exchange resins, in case demineralised water is the only product. However, if the recovery of valuable metals is also taken into account and/or if brine disposal is an issue, then continuous IL metal extraction systems must be regarded as promising alternatives. (C) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.Peer reviewe

    Experimental and molecular modeling evaluation of the physicochemical properties of proline-based deep eutectic solvents

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    The liquid range and applicability of deep eutectic solvents (DESs) are determined by their physicochemical properties. In this work, the physicochemical properties of glycolic acid:proline and malic acid:proline were evaluated experimentally and with MD simulations at five different ratios. Both DESs exhibited esterification upon preparation, which affected the viscosity in particular. In order to minimize oligomer formation and water release, three different experimental preparation methods were explored, but none could prevent esterification. The experimental and calculated densities of the DESs were found to be in good agreement. The measured and modeled glass transition temperature showed similar trends with composition, as did the experimental viscosity and the calculated diffusivities. The MD simulations provided additional insight at the atomistic level, showing that at acid-rich compositions, the acid-acid hydrogen bonding (HB) interactions prevail. Malic acid-based DESs show stronger acid-acid HB interactions than glycolic acid-based ones, possibly explaining its extreme viscosity. Upon the addition of proline, the interspecies interactions become predominant, confirming the formation of the widely assumed HB network between the DESs constituents in the liquid phase.</p

    ACS Virtual Issue on Deep Eutectic Solvents

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    Colposcopy referrals and CIN3 detection after triage by host cell DNA methylation and/or HPV genotyping in HPV positive women with low-grade cytology from a population-based Dutch primary HPV screening trial

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    High-risk HPV (hrHPV)-based screening has led to many unnecessary colposcopy referrals, mainly because of direct referral after low-grade cytology (ASC-US/LSIL). DNA methylation and genotyping tests on ASC-US/LSIL samples have the potential to significantly improve the efficiency of screening. In this study, 12 triage strategies were constructed from FAM19A4/miR124-2 or ASCL1/LHX8 methylation, HPV16/18 or HPV16/18/31/33/45 genotyping and 1-year repeat cytology. The performance was evaluated on 215 hrHPV-positive ASC-US/LSIL samples from the IMPROVE trial (NTR5078). Performance was measured by colposcopy referral rate, positive predictive value (PPV) for detecting precancer (CIN3), and negative predictive value (NPV). To evaluate efficiency, strategies were ordered by the cumulative colposcopy referral rate after 1-year cytology and compared by the marginal PPV to detect one additional CIN3 (mPPV). The most conservative strategy (referral when HPV16/18 and FAM19A4/miR124 methylation results are positive) had a direct referral rate of 5.2%, a cumulative referral rate after 1-year cytology of 54.1%, and mPPV of 19.3%. Replacing HPV16/18 by HPV16/18/31/33/45 increased the cumulative 1-year referral rate to 54.6%, and yielded an mPPV of 10.0%. Similar results were obtained for strategies with ASCL1/LHX8 methylation. Of all strategies, referral after an HPV16/18/31/33/45 positive, ASCL1/LHX8 methylation-positive, and/or 1-year cytology-positive result yielded the highest direct and cumulative 1-year colposcopy referral rates of 64.4% and 79.1%, respectively. The NPVs after 1-year cytology varied between 98.1% and 99.4%, warranting a return to routine screening. Altogether, DNA methylation-based triage strategies are recommended as they are discriminative for CIN3 and control the number of immediate colposcopy referrals.</p

    Thermophysical properties of imidazolium tricyanomethanide ionic liquids: experiments and molecular simulation

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    The low-viscous tricyanomethanide ([TCM]−)-based ionic liquids (ILs) are gaining increasing interest as attractive fluids for a variety of industrial applications. The thermophysical properties (density, viscosity, surface tension, electrical conductivity and self-diffusion coefficient) of the 1-alkyl-3-methylimidazolium tricyanomethanide [Cnmim][TCM] (n = 2, 4 and 6–8) IL series were experimentally measured over the temperature range from 288 to 363 K. Moreover, a classical force field optimized for the imidazolium-based [TCM]− ILs was used to calculate their thermodynamic, structural and transport properties (density, surface tension, self-diffusion coefficients, viscosity) in the temperature range from 300 to 366 K. The predictions were directly compared against the experimental measurements. The effects of anion and alkyl chain length on the structure and thermophysical properties have been evaluated. In cyano-based ILs, the density decreases with increasing molar mass, in contrast to the behavior of the fluorinated anions, being in agreement with the literature. The contribution per –CH2– group to the increase of the viscosity presents the following sequence: [PF6]− > [BF4]− > [Tf2N]− > [DCA]− > [TCB]− > [TCM]−. [TCM]−-based ILs show lower viscosity than dicyanamide ([DCA]−)- and tetracyanoborate ([TCB]−)-based ILs, while the latter two exhibit a crossover which depends both on temperature and the alkyl chain length of the cation. The surface tension of the investigated ILs decreases with increasing alkyl chain length. [C2mim][TCM] shows an outlier behavior compared to other members of the homologous series. The surface enthalpies and surface entropies for all the studied systems have been calculated based on the experimentally determined surface tensions. The relationship between molar conductivity and viscosity was analyzed using the Walden rule. The experimentally determined self-diffusion coefficients of the cations are in good agreement with the molecular simulation predictions, in which a decrease of the self-diffusion of the cations with increasing alkyl chain length is observed with a simultaneous increase in viscosity and for the longer alkyl lengths the anion becomes more mobile than the cation

    Short-term surgical complications after radical hysterectomy - a nationwide cohort study

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    Introduction: Centralization has, among other aspects, been argued to have an impact on quality of care in terms of surgical morbidity. Next, monitoring quality of care is essential in identifying areas of improvement. This nationwide cohort study was conducted to determine the rate of short-term surgical complications and to evaluate its possible predictors in women with early-stage cervical cancer. Material and methods: Women diagnosed with early-stage cervical cancer, 2009 FIGO stages IB1 and IIA1, between 2015 and 2017 who underwent radical hysterectomy with pelvic lymphadenectomy in 1 of the 9 specialized medical centers in the Netherlands, were identified from the Netherlands Cancer Registry. Women were excluded if primary treatment consisted of hysterectomy without parametrial dissection or radical trachelectomy. Women in whom radical hysterectomy was aborted during the procedure, were also excluded. Occurrence of intraoperative and postoperative complications and type of complications, developing within 30 days after surgery, were prospectively registered. Multivariable logistic regression analysis was used to identify predictors of surgical complications. Results: A total of 472 women were selected, of whom 166 (35%) developed surgical complications within 30 days after radical hysterectomy. The most frequent complications were urinary retention with catheterization in 73 women (15%) and excessive perioperative blood loss >1000 mL in 50 women (11%). Open surgery (odds ratio [OR] 3.42; 95% CI 1.73-6.76), chronic pulmonary disease (OR 3.14; 95% CI 1.45-6.79), vascular disease (OR 1.90; 95% CI 1.07-3.38), and medical center (OR 2.83; 95% CI 1.18-6.77) emerged as independent predictors of the occurrence of complications. Body mass index (OR 0.94; 95% CI 0.89-1.00) was found as a negative predictor of urinary retention. Open surgery (OR 36.65; 95% CI 7.10-189.12) and body mass index (OR 1.15; 95% CI 1.08-1.22) were found to be independent predictors of excessive perioperative blood loss. Conclusions: Short-term surgical complications developed in 35% of the women after radical hysterectomy for early-stage cervical cancer in the Netherlands, a nation with centralized surgical care. Comorbidities predict surgical complications, and open surgery is associated with excessive perioperative blood loss

    Evaluation of the recently established Dutch nationwide Archipelago of Ovarian Cancer Research biobank

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    Fundamental and translational research in ovarian cancer aims to enhance understanding of disease mechanisms and improve treatment and survival outcomes. To support this, we established the Dutch multicenter, interdisciplinary Archipelago of Ovarian Cancer Research (AOCR) infrastructure, which includes a nationwide biobank. In this study, we share our experiences in establishing the infrastructure, offer guidance for similar initiatives, and evaluate the AOCR patient cohort. Key challenges included obtaining Data Protection Impact Assessment (DPIA) clearance, drafting the consortium agreement, and securing ethical approval from all hospitals. Over three years, 1093 patients were enrolled across 17 hospitals, resulting in the collection of 1339 tissue samples and 2280 blood samples. Of the 523 patients with currently available clinical and pathological data, 74 % (n = 387) had primary ovarian cancer. Among these patients, 73.4 % was diagnosed with high-grade serous ovarian carcinoma, and 80.9 % presented with advanced-stage disease. Surgery was performed on 93 % of patients with primary ovarian cancer, and chemotherapy was administered to 90.4 % of these patients. In conclusion, the AOCR biobank has established a robust foundation for future fundamental and translational ovarian cancer research. This manuscript provides valuable insights and guidance for developing future research infrastructures and biobanks, and contains detailed information about the AOCR patient cohort to date
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