38 research outputs found

    Interfacial Molecular Imprinting in Nanoparticle-Stabilized Emulsions

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    A new interfacial nano and molecular imprinting approach is developed to prepare spherical molecularly imprinted polymers with well-controlled hierarchical structures. This method is based on Pickering emulsion polymerization using template-modified colloidal particles. The interfacial imprinting is carried out in particle-stabilized oil-in-water emulsions, where the molecular template is presented on the surface of silica nanoparticles during the polymerization of the monomer phase. After polymerization, the template-modified silica nanoparticles are removed from the new spherical particles to leave tiny indentations decorated with molecularly imprinted sites. The imprinted microspheres prepared using the new interfacial nano and molecular imprinting have very interesting features: a well-controlled hierarchical structure composed of large pores decorated with easily accessible molecular binding sites, group selectivity toward a series of chemicals having a common structural moiety (epitopes), and a hydrophilic surface that enables the MIPs to be used under aqueous conditions

    Global Retinoblastoma Presentation and Analysis by National Income Level.

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    Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs

    The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries

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    DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt

    Molecular imprinting in Pickering emulsions: a new insight into molecular recognition in water.

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    Molecularly imprinted polymer microspheres were synthesized by Pickering emulsion polymerization. Fluorescence spectroscopic investigations provided insights into the template recognition in water

    Molecularly imprinted magnetic materials prepared from modular and clickable nanoparticles

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    We report a new strategy toward construction of functional composite materials for fast molecular separation. Molecularly imprinted nanoparticles containing surface-exposed alkyne groups were synthesized by one-pot precipitation polymerization. Magnetic Fe3O4 nanoparticles were first coated with a silica shell, and then modified with terminal azide groups. The two types of clickable nanoparticles were conjugated through a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction to give composite magnetic particles, which displayed high molecular recognition selectivity and could be easily separated using a simple magnet

    Molecularly Imprinted Polymers for Clean Water: Analysis and Purification

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    Because of their predetermined selectivity, molecularly imprinted polymers (MIPs) have been extensively investigated to offer efficient separation of organic pollutants for water analysis and purification. In this review, we first describe the current development of water compatible MIPs, and the physical encapsulation and chemical immobilization of MIP particles for practical applications related to water analysis and purification. We summarize the challenges in understanding the mechanisms in molecular imprinting, with a special emphasis on the use of nuclear magnetic resonance (NMR), dynamic light scattering (DLS), and synchronous fluorescence spectroscopy to gain theoretical insights into the molecular imprinting process. The highlighted synthetic methods and the mechanistic investigations discussed in this review should facilitate the identification of the most crucial factors affecting the applications of MIPs for clean water

    Imprinted polymer beads enabling direct and selective molecular separation in water

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    In this paper, we describe the synthesis of water-compatible Molecularly Imprinted Polymer (MIP) microspheres by nanoparticle-stabilized emulsion (Pickering emulsion) polymerization. During the polymerization, the amount of the porogen used not only affected the stability of the Pickering emulsion but also the specific molecular recognition of the obtained MIP microspheres. Under optimized conditions, the MIP microspheres synthesized had a porous and hydrophilic surface. Scanning electron microscopy and fluorescent labeling experiments indicated that the MIP microspheres had particle sizes of 165 +/- 38 mu m. Selective molecular recognition with the MIP microspheres was studied through equilibrium binding analysis and liquid chromatography experiments under pure aqueous conditions. Using the new MIP microspheres as solid phase extraction (SPE) absorbents, low concentration organic pollutants (beta-blockers) were effectively enriched from tap water and easily detected using HPLC-MS analysis

    Synthesis of Bacteria Imprinted Polymers by Pickering Emulsion Polymerization

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    Molecularly imprinted polymers have been studied for a long time and have found useful applications in many fields. In most cases, small organic molecules are used as templates to synthesize imprinted polymers. In contrast to low molecular weight targets, large biological molecules and cells are more challenging to use as templates to synthesize cell-recognizing materials. This chapter presents an interfacial imprinting method to synthesize bacteria-recognizing polymer beads using Pickering emulsion polymerization. The tendency of bacteria to reside between two immiscible liquids is utilized to create surface-imprinted binding sites on cross-linked polymer microspheres
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