Anionic multiblock core cross-linked star copolymers via RAFT polymerization

Poly(2-acrylamido-2-methylpropane sulfonic acid) is a polyelectrolyte currently used in numerous industrial applications. Herein, we report the use of reversible addition fragmentation chain transfer (RAFT) polymerization to prepare a range of well-defined homopolymers and block copolymers of 2-acrylamido-2-methylpropane sulfonic acid (AMPS®) and either N-hydroxyethyl acrylamide (HEAm) or 4-acryloylmorpholine (NAM) as a comonomer. We also describe the one-pot synthesis of multiblock core cross-linked star copolymers of AMPS® and HEAm with low dispersities (<1.3). The influence of several parameters such as the cross-linker type, cross-linker to chain transfer agent (CTA) ratio, arm length and composition on the polymerization efficiency are investigated

Sulfonated copolymers as heparin-mimicking stabilizer of fibroblast growth factor : size, architecture, and monomer distribution effects

Fibroblast growth factors (FGF) are involved in a wide range of biological processes such as cell proliferation and differentiation. In living organisms, the binding of FGF to its receptors are mediated through electrostatic interactions between FGF and naturally occurring heparin. Despite its prevalent use in medicine, heparin carries notable limitations, namely; its extraction from natural sources (expensive, low yield and extensive purification), viral contamination, and batch-to-batch heterogeneity. In this work a range of synthetic homopolymers and copolymers of sodium 2-acrylamido-2-methylpropane sulfonate (AMPS®) were evaluated as potential FGF stabilisers. This was studied by measuring the proliferation of BaF3-FR1c cells, as a model assay, and the results will be compared with the natural stabilisation and activation of FGF by heparin. This study explores the structure-activity relationship of these polysulfonated polymers with a focus on the effect of molecular weight, co-monomer type, charge dispersion and polymer architecture on protein stabilisation

Impact of laser-assisted hatching on pregnancy rate in fresh and frozen-thawed cycles

peer reviewe

Exploring precision polymers to fine-tune magnetic resonance imaging properties of iron oxide nanoparticles

The use of bio-polymers as stabilising agents for iron oxide-based negative magnetic resonance imaging (MRI) contrast agents has become popular in recent years, however the wide polydispersity of biologically-derived and commercially available polymers limits the ability to produce truly tuneable and reproducible behaviour, a major challenge in this area. In this work, stable colloids of iron oxide nanoparticles were prepared utilising precision-engineered bio-polymer mimics, poly(2-acrylamido-2-methylpropane sodium sulfonate) (P(AMPS)) polymers, with controlled narrow polydispersity molecular weights, as templating stabilisers. In addition to producing magnetic colloids with excellent MRI contrast capabilities (r values reaching 434.2 mM  s at 25 °C and 23 MHz, several times higher than similar commercial analogues), variable field relaxometry provided unexpected important insights into the dynamic environment of the hydrated materials, and hence their exceptional MRI behaviour. Thanks to the polymer's templating backbone and flexible conformation in aqueous suspension, nanocomposites appear to behave as "multi-core" clustered species, enhancing interparticle interactions whilst retaining water diffusion, boosting relaxation properties at low frequency. This clustering behaviour, evidenced by small-angle X-ray scattering, and strong relaxometric response, was fine-tuned using the well-defined molecular weight polymer species with precise iron to polymer ratios. By also showing negligible haemolytic activity, these nanocomposites exhibit considerable potential for MRI diagnostics. [Abstract copyright: Crown Copyright © 2020. Published by Elsevier Inc. All rights reserved.

Facing homelessness

In facing homelessness we face the other, and in facing the other, we face ourselves. This book contributes to an emerging body of knowledge on street homelessness in the South African context. It is meant for researchers and scholars who are committed to finding solutions for street homelessness. It offers conceptual frameworks and practical guidelines for a liberative and transformative response to homelessness. It brings together authors from a wide range of disciplines, fusing the rigour of researchers, the vision of activists and the lived experience of practitioners. In this volume, the causes of street homelessness in South Africa today, and its different faces, are traced. It critiques singular solutions, and interrogates the political, institutional and moral failures that contribute to the systemic exclusion of homeless persons and other vulnerable populations from society. It proposes rights-based interventions as part of a radical re-imagination of how street homelessness can be ended, one person and one neighbourhood at a time. The analysis by the authors steer in the direction of new ways of doing and being that could demonstrate concrete, viable and sustainable alternatives to the exclusionary realities faced by homeless persons. It argues for solution-based approaches, aimed at radical forms of social inclusion and achieved through broad-based and creative collaborations by all spheres of society. In the face and presence of street homelessness – as one expression of urban vulnerability and deep socio-economic inequality – society is confronted with a clear political, institutional, moral and personal obligation. This volume calls for a reclamation of community in its most inclusionary, life-affirming and interdependent sense, asserting that we truly are well because of others, and we are unwell if others are. It is a call to reclaim our common humanity in the context of inclusive communities where all are equally welcome and bestowed with dignity and honour

Facing homelessness

In facing homelessness we face the other, and in facing the other, we face ourselves. This book contributes to an emerging body of knowledge on street homelessness in the South African context. It is meant for researchers and scholars who are committed to finding solutions for street homelessness. It offers conceptual frameworks and practical guidelines for a liberative and transformative response to homelessness. It brings together authors from a wide range of disciplines, fusing the rigour of researchers, the vision of activists and the lived experience of practitioners. In this volume, the causes of street homelessness in South Africa today, and its different faces, are traced. It critiques singular solutions, and interrogates the political, institutional and moral failures that contribute to the systemic exclusion of homeless persons and other vulnerable populations from society. It proposes rights-based interventions as part of a radical re-imagination of how street homelessness can be ended, one person and one neighbourhood at a time. The analysis by the authors steer in the direction of new ways of doing and being that could demonstrate concrete, viable and sustainable alternatives to the exclusionary realities faced by homeless persons. It argues for solution-based approaches, aimed at radical forms of social inclusion and achieved through broad-based and creative collaborations by all spheres of society. In the face and presence of street homelessness – as one expression of urban vulnerability and deep socio-economic inequality – society is confronted with a clear political, institutional, moral and personal obligation. This volume calls for a reclamation of community in its most inclusionary, life-affirming and interdependent sense, asserting that we truly are well because of others, and we are unwell if others are. It is a call to reclaim our common humanity in the context of inclusive communities where all are equally welcome and bestowed with dignity and honour

Expanding the clinical spectrum of hereditary fibrosing poikiloderma with tendon contractures, myopathy and pulmonary fibrosis due to <i>FAM111B </i>mutations

BACKGROUND: Hereditary Fibrosing Poikiloderma (HFP) with tendon contractures, myopathy and pulmonary fibrosis (POIKTMP [MIM 615704]) is a very recently described entity of syndromic inherited poikiloderma. Previously by using whole exome sequencing in five families, we identified the causative gene, FAM111B (NM_198947.3), the function of which is still unknown. Our objective in this study was to better define the specific features of POIKTMP through a larger series of patients. METHODS: Clinical and molecular data of two families and eight independent sporadic cases, including six new cases, were collected. RESULTS: Key features consist of: (i) early-onset poikiloderma, hypotrichosis and hypohidrosis; (ii) multiple contractures, in particular triceps surae muscle contractures; (iii) diffuse progressive muscular weakness; (iv) pulmonary fibrosis in adulthood and (v) other features including exocrine pancreatic insufficiency, liver impairment and growth retardation. Muscle magnetic resonance imaging was informative and showed muscle atrophy and fatty infiltration. Histological examination of skeletal muscle revealed extensive fibroadipose tissue infiltration. Microscopy of the skin showed a scleroderma-like aspect with fibrosis and alterations of the elastic network. FAM111B gene analysis identified five different missense variants (two recurrent mutations were found respectively in three and four independent families). All the mutations were predicted to localize in the trypsin-like cysteine/serine peptidase domain of the protein. We suggest gain-of-function or dominant-negative mutations resulting in FAM111B enzymatic activity changes. CONCLUSIONS: HFP with tendon contractures, myopathy and pulmonary fibrosis, is a multisystemic disorder due to autosomal dominant FAM111B mutations. Future functional studies will help in understanding the specific pathological process of this fibrosing disorder

Speech Communication

Contains table of contents for Part V, table of contents for Section 1, reports on six research projects and a list of publications.C.J. Lebel FellowshipDennis Klatt Memorial FundNational Institutes of Health Grant R01-DC00075National Institutes of Health Grant R01-DC01291National Institutes of Health Grant R01-DC01925National Institutes of Health Grant R01-DC02125National Institutes of Health Grant R01-DC02978National Institutes of Health Grant R01-DC03007National Institutes of Health Grant R29-DC02525National Institutes of Health Grant F32-DC00194National Institutes of Health Grant F32-DC00205National Institutes of Health Grant T32-DC00038National Science Foundation Grant IRI 89-05249National Science Foundation Grant IRI 93-14967National Science Foundation Grant INT 94-2114