Surface induced selective delamination of amphiphilic ABA block copolymer thin films

This is the result of an ongoing collaboration with Dr. N. Sommerdijk’s Biomaterials group at the University of Eindhoven (the Netherlands) and illustrates the close collaboration that exists in pursuing the design and application of novel polymeric materials between the two groups. This details work on a physical phenomenon (selective delamination) and key materials (amphiphilic block copolymers) that have subsequently been applied in the design of novel biomaterials. These results have appeared in a larger body of work including Advanced Materials, Angewandtie Chemie International Edition and the Journal of Materials Chemistry

Colorectal cancer screening: Barriers to the faecal occult blood test (FOBT) and colonoscopy in Singapore

Introduction: This study aims to identify the barriers to adopting faecal occult blood test (FOBT) and colonoscopy as colorectal cancer (CRC) screening methods among the eligible target population of Singapore. Materials and methods: This study was previously part of a randomised controlled trial reported elsewhere. Data was collected from Singapore residents aged 50 and above, via a household sample survey. The study recruited subjects who were aware of CRC screening methods, and interviewed them about the barriers to screening that they faced. Collected results on barriers to each screening method were analysed separately. Results: Out of the 343 subjects, 85 (24.8%) recruited knew about FOBT and/or colonoscopy. Most of the respondents (48.9%) cited not having symptoms as the reason for not using the FOBT. This is followed by inconvenience (31.1%), not having any family history of colon cancer (28.9%), lack of time (28.9%) and lack of reminders/recommendation (28.9%). Of the respondents who indicated not choosing colonoscopy as a screening method, more than one-half (54.8%) identified not having any symptoms as the main barrier for them, followed by not having any family history (38.7%) and having a healthy/low-risk lifestyle (29.0%). There was no difference between the reported barriers to each of the screening methods and the respondents\u27 dwelling types. Conclusions: Lack of knowledge, particularly the misconceptions of not having symptoms and being healthy, were identified as the main barriers to FOBT and colonoscopy as screening methods. Interventions to increase the uptake of CRC screening in this population should be tailored to address this misconception

Colorectal cancer screening: Barriers to the faecal occult blood test (FOBT) and colonoscopy in Singapore

Introduction: This study aims to identify the barriers to adopting faecal occult blood test (FOBT) and colonoscopy as colorectal cancer (CRC) screening methods among the eligible target population of Singapore. Materials and methods: This study was previously part of a randomised controlled trial reported elsewhere. Data was collected from Singapore residents aged 50 and above, via a household sample survey. The study recruited subjects who were aware of CRC screening methods, and interviewed them about the barriers to screening that they faced. Collected results on barriers to each screening method were analysed separately. Results: Out of the 343 subjects, 85 (24.8%) recruited knew about FOBT and/or colonoscopy. Most of the respondents (48.9%) cited not having symptoms as the reason for not using the FOBT. This is followed by inconvenience (31.1%), not having any family history of colon cancer (28.9%), lack of time (28.9%) and lack of reminders/recommendation (28.9%). Of the respondents who indicated not choosing colonoscopy as a screening method, more than one-half (54.8%) identified not having any symptoms as the main barrier for them, followed by not having any family history (38.7%) and having a healthy/low-risk lifestyle (29.0%). There was no difference between the reported barriers to each of the screening methods and the respondents\u27 dwelling types. Conclusions: Lack of knowledge, particularly the misconceptions of not having symptoms and being healthy, were identified as the main barriers to FOBT and colonoscopy as screening methods. Interventions to increase the uptake of CRC screening in this population should be tailored to address this misconception

Nordic Homicide in Deep Time

Nordic Homicide in Deep Time draws a unique and detailed picture of developments in human interpersonal violence and presents new findings on rates, patterns, and long-term changes in lethal violence in the Nordics. Conducted by an interdisciplinary team of criminologists and historians, the book analyses homicide and lethal violence in northern Europe in two eras – the 17th century and early 21st century. Similar and continuous societal structures, cultural patterns, and legal cultures allow for long-term and comparative homicide research in the Nordic context. Reflecting human universals and stable motives, such as revenge, jealousy, honour, and material conflicts, homicide as a form of human behaviour enables long-duration comparison. By describing the rates and patterns of homicide during these two eras, the authors unveil continuity and change in human violence. Where and when did homicide typically take place? Who were the victims and the offenders, what where the circumstances of their conflicts? Was intimate partner homicide more prevalent in the early modern period than in present times? How long a time elapsed from violence to death? Were homicides often committed in the context of other crime? The book offers answers to these questions among others, comparing regions and eras. We gain a unique and empirically grounded view on how state consolidation and changing routines of everyday life transformed the patterns of criminal homicide in Nordic society. The path to pacification was anything but easy, punctuated by shorter crises of social turmoil, and high violence. The book is also a methodological experiment that seeks to assess the feasibility of long-duration standardized homicide analysis and to better understand the logic of homicide variation across space and over time. In developing a new approach for extending homicide research into the deep past, the authors have created the Historical Homicide Monitor. The new instrument combines wide explanatory scope, measurement standardization, and articulated theory expression. By retroactively expanding research data to the pre-statistical era, the method enables long-duration comparison of different periods and areas. Based on in-depth source critique, the approach captures patterns of criminal behaviour, beyond the control activity of the courts. The authors foresee the application of their approach in even remoter periods. Nordic Homicide in Deep Time helps the reader to understand modern homicide by revealing the historical continuities and changes in lethal violence. The book is written for professionals, university students and anyone interested in the history of human behaviour

ABA triblock copolymers: from controlled synthesis to controlled function

The ABA amphiphilic block copolymers, poly(hydroxyethyl methacrylate-hlock-methylphenylsilane-block-hydroxyethyl methacrylate) (PHEMA-PMPS-PHEMA) and poly[oligo(ethylene glycol) methyl ether methacrylate-block-methylphenylsilane-block-oligo(ethylene glycol). methyl ether methacrylate] (POEGMA-PMPS-POEGMA) were successfully synthesised via atom transfer radical polymerisation (ATRP). Macroinitiators suitable for the ATRP of oligo(ethylene glycol) methyl ether methacrylate and 2-hydroxyethyl methacrylate were synthesised from the condensation reaction of alpha,omega-dihalopolymethylphenylsilane and 2'-hydroxyethyl 2-bromo-2-methylpropanoate. The copolymers were characterised using H-1 NMR and C-13 NMR spectroscopy and molecular weight characteristics were determined using size exclusion chromatography and H-1 NMR. The aggregation behaviour of some of the copolymers in water was studied using transmission and scanning electron microscopy and dynamic light scattering. These revealed the prevalent aggregate species to be micelles. Larger aggregates of 300-1000 nm diameter were also observed. The UV induced degradation of the aggregates was studied by UV-Vis spectroscopy. The thermal behaviour of selected copolymers was studied by differential scanning calorimetry and microphase separation of the two components was demonstrated

ABA Amphiphilic block copolymers with comb-like segments from ATRP: Self-assembly in aqueous and electrolyte solutions

Amphiphilic block copolymers (BCs) can self-organize into various aggregates morphologies in solution where the solvent is selective for one of the blocks. The size and the shape of these various molecular assemblies depends on the balance of hydrophilic and hydrophobic regions of the block copolymer. Among these aggregates, vesicles, which have been considered as powerful nanocarriers, are especially interesting for their applications in the design of drug delivery systems. Here we report preliminary results of our studies into the self-assembly behaviour in aqueous dispersions of poly[olig(ethylene glycol methyl ether)]-block-polystyrene-block-[olig(ethylene glycol methyl ether)] (POEGMA-PS-POEGMA) prepared by atom transfer radical polymerisation techniques (ATRP) for different hydrophilic:hydrophobic weight ratios between the blocks. Size and morphology of the aggregates were analysed by TEM and dynamic light scattering. The effects of two salts, NaCl and CaBr2 on the aggregation behaviour were studied and fluorescence measurements were also carried out in order to determine the critical aggregation concentration (c.a.c.) and to exhibit the encapsulation of a fluorescent probe

The synthesis of methacrylate amphiphilic diblock and triblock copolymers by copper mediated atom transfer radical polymerisation

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Towards inclusive service delivery through social investment in Romania. An analysis of five sectors, with a particular focus on Early Childhood Education and Care in Roma communities

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PVP2004-2755 PLASTIC AND CREEP ANALYSES OF THE SUPERHEATER HEADER TUBEPLATE USING LINEAR MATCHING METHOD

ABSTRACT In 2003 ASME PVP conference, a series of numerical procedures for integrity assessment based upon recently developed Linear Matching Method were presented INTRODUCTION The integrity assessment for the high temperature response of structures, including fatigue and creep analyses, is required in the evaluation of engineering structures exposed to high temperature environment, especially for the components of power producing plants. In the past decades, British Energy Generation's R5 integrity assessment procedure The life assessment involving plasticity and creep deformation of the tubeplate lower radius, tubeplate ligaments and tube/tubeplate welds of a typical AGR superheater headers was reported in Not only the plastic mechanism, the tubeplate structures exposed to high temperature environment exhibit time dependent behaviour. Creep dwell periods exist where the temperature of some proportion of the structure lies within the creep range. In such circumstances, the mechanical loads can be relatively small but the thermal stresses ca

Physiological response to temperature changes of the marine, sulphate-reducing bacterium Desulfobacterium autotrophicum

Abstract The physiological response of bacteria to temperature is critical for the regulation of biogeochemical processes on daily, seasonal, and inter-annual time scales. We investigated the temperature response of the marine sulfate-reducing bacterium Desulfobacterium autotrophicum strain HRM2. Growth experiments in a temperature gradient block demonstrated that D. autotrophicum is psychrotolerant and grows between 0 and 31 ‡C. The normal range of temperature for growth is between 4 and 29 ‡C. The physiological response to temperature changes was studied with three sets of cells that were acclimated at 4, 10, and 28 ‡C, respectively. Sulfate reduction rates were determined in the temperature gradient block with short-term incubations to minimize growth. The rates were similar at the 4 and 10 ‡C acclimation temperature, and exhibited an enhanced response at 28 ‡C. At every acclimation temperature, sulfate reduction rates increased 20-fold from 31.7 to 41 ‡C. The relative proportion of cellular unsaturated fatty acids (e.g. cis16:1) and short-chain fatty acids increased when cells were grown at 4 ‡C compared to 28 ‡C. The proteome of D. autotrophicum strain HRM2 was studied by two-dimensional gel electrophoresis with soluble extracts of cells grown at the three respective acclimation temperatures. Protein patterns were similar with the exception of two proteins showing 5^10-fold lower abundance in the 4 ‡C culture compared to the 28 ‡C culture. In general, D. autotrophicum strain HRM2 responded to low temperatures by reduced metabolic activity rather than by pronounced de novo synthesis of specifically adapted enzymes. Such a strategy agrees well with in situ activities measured in field studies and may reflect a common physiological principle of psychrotolerant marine sulfate-reducing bacteria.