77 research outputs found

    Role of hydrophobic and electrostatic Interactions for initial enteric virus retention by MF membranes

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    Membranes are of increasing interest for the removal of human enteric viruses from wastewater, especially when the goal of treatment is reuse. Limited work has been undertaken on fundamental issues such as aggregation and the role of electrostatic and hydrophobic interactions, as opposed to the sieving of viruses by membranes. One apparently critical factor would be the iso-electric point (pI) of a virus. As an example of a worst-case model virus, the retention of bacteriophage MS-2 was investigated using hydrophobic (GVHP) and hydrophilic (GVWP) 0.22 mm MF membranes at different pH levels and with different salts. High retention levels were measured at the iso-electric point of MS-2, pH 3.9 (5 log retention) and pH 7 (4.3 log retention) in the presence of salts and with a hydrophobic membrane. When retention was compared on a hydrophilic membrane, it was clear that hydrophobic interactions dominated virus retention, and this was improved by salt, presumably causing reduction of the Gouy double-layer when MS-2 was charged (pH 7). This paper shows that knowledge of the adsorption characteristics of viruses and the suspending conditions are important to predict removal of viruses by hydrophobic MF membranes, and discusses some of the practical implications of these important hydrophobic interactions

    Hepatocellular adenoma in men:A nationwide assessment of pathology and correlation with clinical course

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    BACKGROUND & AIMS: Hepatocellular adenomas (HCA) rarely occur in males, and if so, are frequently associated with malignant transformation. Guidelines are based on small numbers of patients and advise resection of HCA in male patients, irrespective of size or subtype. This nationwide retrospective cohort study is the largest series of HCA in men correlating (immuno)histopathological and molecular findings with the clinical course. METHODS: Dutch male patients with available histological slides with a (differential) diagnosis of HCA between 2000 and 2017 were identified through the Dutch Pathology Registry (PALGA). Histopathology and immunohistochemistry according to international guidelines were revised by two expert hepatopathologists. Next generation sequencing (NGS) was performed to confirm hepatocellular carcinoma (HCC) and/or subtype HCA. Final pathological diagnosis was correlated with recurrence, metastasis and death. RESULTS: A total of 66 patients from 26 centres fulfilling the inclusion criteria with a mean (±SD) age of 45.0 ± 21.6 years were included. The diagnosis was changed after expert revision and NGS in 33 of the 66 patients (50%). After a median follow‐up of 9.6 years, tumour‐related mortality of patients with accessible clinical data was 1/18 (5.6%) in HCA, 5/14 (35.7%) in uncertain HCA/HCC and 4/9 (44.4%) in the HCC groups (P = .031). Four B‐catenin mutated HCA were identified using NGS, which were not yet identified by immunohistochemistry and expert revision. CONCLUSIONS: Expert revision with relevant immunohistochemistry may help the challenging but prognostically relevant distinction between HCA and well‐differentiated HCC in male patients. NGS may be more important to subtype HCA than indicated in present guidelines

    The Prospective Dutch Colorectal Cancer (PLCRC) cohort: real-world data facilitating research and clinical care

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    Real-world data (RWD) sources are important to advance clinical oncology research and evaluate treatments in daily practice. Since 2013, the Prospective Dutch Colorectal Cancer (PLCRC) cohort, linked to the Netherlands Cancer Registry, serves as an infrastructure for scientific research collecting additional patient-reported outcomes (PRO) and biospecimens. Here we report on cohort developments and investigate to what extent PLCRC reflects the “real-world”. Clinical and demographic characteristics of PLCRC participants were compared with the general Dutch CRC population (n = 74,692, Dutch-ref). To study representativeness, standardized differences between PLCRC and Dutch-ref were calculated, and logistic regression models were evaluated on their ability to distinguish cohort participants from the Dutch-ref (AU-ROC 0.5 = preferred, implying participation independent of patient characteristics). Stratified analyses by stage and time-period (2013–2016 and 2017–Aug 2019) were performed to study the evolution towards RWD. In August 2019, 5744 patients were enrolled. Enrollment increased steeply, from 129 participants (1 hospital) in 2013 to 2136 (50 of 75 Dutch hospitals) in 2018. Low AU-ROC (0.65, 95% CI: 0.64–0.65) indicates limited ability to distinguish cohort participants from the Dutch-ref. Characteristics that remained imbalanced in the period 2017–Aug’19 compared with the Dutch-ref were age (65.0 years in PLCRC, 69.3 in the Dutch-ref) and tumor stage (40% stage-III in PLCRC, 30% in the Dutch-ref). PLCRC approaches to represent the Dutch CRC population and will ultimately meet the current demand for high-quality RWD. Efforts are ongoing to improve multidisciplinary recruitment which will further enhance PLCRC’s representativeness and its contribution to a learning healthcare system

    Nutrient removal by NF and RO membranes in a decentralized sanitation system

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    Decentralized treatment of domestic wastewater offers the possibility of water and nutrient reuse. In a decentralized sanitation system the household wastewater streams are separated in a large diluted stream (gray water) and a small and concentrated stream (black water) containing important nutrients like ammonium and phosphate. Nanofiltration (NF) and reverse osmosis (RO) membranes might be used to recover the nutrients from anaerobically treated black water. The permeate might be used in a water reuse scheme. In case of water reuse the produced permeate should meet guidelines for potable water or meet new guidelines which might be applied in the future for intermediate quality of water, for example toilet flushwater; when this is not possible the permeate should meet guidelines for discharge. The most stringent guidelines apply for ammonium and phosphate. The focus of this paper is to test commercially available NF and RO membranes to remove nutrients from anaerobically treated black water in order to meet the Dutch guidelines. A large number of commercial tubular, capillary and flat sheet NF and RO membranes was tested on laboratory scale on their performance to meet the Dutch guidelines for ammonium and phosphate. The ammonium and phosphate concentrations used were based on the effluent composition of anaerobically treated black water. Ammonium and phosphate rejection were both measured in synthetic single salt and multi-ion mixtures and in anaerobic effluent.\ud \ud The rejection for ammonium (30Âż95%) is neither sufficient for discharge nor potable water use. The rejection of phosphate (74Âż99%) is in most cases almost sufficient to meet the standards for potable water

    Café science for kids.

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    Café science for kids

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