39 research outputs found
Response by P Pells to Discussion by Koutsoftas "Rock Quality Designation (RQD): Time to Rest in Peace"
No full textResponse by P Pells to Discussion by Koutsoftas "Rock Quality Designation: Time to Rest in Peace"The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Paracrine signalling events in embryonic stem cell renewal mediated by affinity targeted nanoparticles
No full textStem cell growth and differentiation is controlled by intrinsic and extrinsic factors. The latter includes growth factors, which are conventionally supplied in vitro in media exchanged daily. Here, we illustrate the use of affinity targeted biodegradable nanoparticles to mediate paracrine stimulation as an alternative approach to sustain the growth and pluripotency of mouse embryonic stem cells. Leukaemia Inhibitory Factor (LIF) was encapsulated in biodegradable nanoparticles and targeted to the cell surface using an antibody to the oligosaccharide antigen SSEA-1. Sustained release of LIF from nanoparticles composed of a solid Poly(lactide-co-glycolic acid) polyester or a hydrogel-based liposomal system, we term Nanolipogel, replenished once after each cell passage, proved as effective as daily replenishment with soluble LIF for maintenance of pluripotency after 5 passages using 10(4)-fold less LIF. Our study constitutes an alternative paradigm for stem cell culture, providing dynamic microenvironmental control of extrinsic bioactive factors benefiting stem cell manufacturing
Reassessing frontline medical practitioners of the British civil wars in the context of the seventeenth-century medical world
No full textThis is the author accepted manuscript. The final version is available from Cambridge University Press via the DOI in this recordMedical provision in Civil War armies has generally suffered a poor reputation. Medical matters have been excluded from assessments of how far Civil War armies confirm evidence of the so-called ‘Military Revolution’, whilst Harold Cook argued that it was not until after the Glorious Revolution that the medical infrastructure of the armed forces was brought in line with continental practices, particularly those of the Dutch army. Despite the recent rehabilitation of early modern practitioners elsewhere, frontline military practitioners continue to be dismissed as uneducated, unskilful and incompetent. This is largely due to the lack of a fresh perspective since C. H. Firth published Cromwell's Army in 1902. This article argues that the English were well aware of current medical practice in European armies and endeavoured to implement similar procedures during the Civil Wars. Indeed, almost all the developments identified by Cook for the later seventeenth century can be found in Civil War armies. Whilst failures may have occurred, most of these can be attributed to administrative and financial miscarriages, rather than ignorance of contemporary medical developments. Moreover, there is little to suggest that medics mobilized for Civil War armies were any less capable than those who practised civilian medicine in this period.This article draws on research undertaken whilst a postdoctoral research associate on the Wellcome Trust-funded project ‘The Medical World of Early Modern England, Wales and Ireland, c. 1500–1715’ at the University of Exeter (grant reference number 097782/Z/11/Z)
The church's ancient Bible; the Septuagint, the Old Latin, the Latin Vulgate, the Bible in the Book of common prayer, and the English Bibles. Their history, and the sources from whence they were translated or derived, with a summary ... also an appendix "The tomb of David" - two great discoveries,
No full textMode of access: Internet
Sufficiency of hypoxia-inducible 2-oxoglutarate dioxygenases to block chemical oxidative stress-induced differentiation of human embryonic stem cells
No full textHypoxia benefits undifferentiated pluripotent stem cell renewal, and 2-oxoglutarate (2OG) dioxygenases have been implicated in pluripotent stem cell induction and renewal. We show in human embryonic stem cells (hESC) that an ambient oxygen-induced oxidative stress response elicited by culture in a hypoxic atmosphere (0.5% O2) correlates with the expression of 2OG dioxygenases, which oxidise DNA (TET1, 2, 3) and histone H3 (KDM4C), the former reflected by elevation in genomic 5-hydroxymethylcytosine (5hmC). siRNA-mediated targeting of KDM4C and TET1–3 induces hESC differentiation. Under ambient atmospheric oxygen (21% O2), exposure to a low inhibitory concentration of sodium arsenite (NaAsO2, IC10), as a model of chemically-induced oxidative stress, suppresses antioxidant gene expression, reduces mitochondrial membrane potential and induces hESC differentiation. Co-administration of the antioxidant N-acetyl-L-cysteine promoted anti-oxidant, pluripotency and 2OG dioxygenase gene expression, elevated genomic hydroxymethylation and blocked induction of differentiation. Transient ectopic expression of KDM4C or TET1 in ambient atmospheric oxygen achieved the same. Our study substantiates a role for 2OG-dependent dioxygenases in hypoxia's promotion of undifferentiated hESC self-renewal
Dielectrophoresis: A Review of Applications for Stem Cell Research
No full textDielectrophoresis can discriminate distinct cellular identities in heterogeneous populations, and monitor cell state changes associated with activation and clonal expansion, apoptosis, and necrosis, without the need for biochemical labels. Demonstrated capabilities include the enrichment of haematopoetic stem cells from bone marrow and peripheral blood, and adult stem cells from adipose tissue. Recent research suggests that this technique can predict the ultimate fate of neural stem cells after differentiation before the appearance of specific cell-surface proteins. This review summarises the properties of cells that contribute to their dielectrophoretic behaviour, and their relevance to stem cell research and translational applications.</p
Analysis of the nucleolar compartment of the nucleus as an indicator of nuclear reprogramming after nuclear transfer
No full textInternational audienc
Dielectrophoretic Characterisation of Mammalian Cells above 100 MHz
No full textAbstract
Dielectrophoresis (DEP) is a label-free technique for the characterization and manipulation of biological particles - such as cells, bacteria and viruses. Many studies have focused on the DEP cross-over frequency f
xo1, where cells in a non-uniform electric field undergo a transition from negative to positive DEP. Determination of f
xo1 provides a value for the membrane capacitance from the cell diameter, the means to monitor changes in cell morphology and viability, and the information required when devising DEP cell separation protocols. In this paper we describe the first systematic measurements of the second DEP cross-over frequency f
xo2 that occurs at much higher frequencies. Theory indicates that f
xo2 is sensitive to the internal dielectric properties of a cell, and our experiments on murine myeloma cells reveal that these properties exhibit temporal changes that are sensitive to both the osmolality and temperature of the cell suspending medium.</jats:p
