1,214 research outputs found
Glycerol stabilizes oxygen evolution and maintains binding of a 9 kDa polypeptide in photosystem II particles from the cyanobacterium, Phormidium laminosum
AbstractHigh concentrations of glycerol (⩾20% vv) stabilize oxygen evolution in photosystem (PS) II particles from the thermophilic cyanobacterium, Phormidium laminosum. Treating PS II particles with lower glycerol concentrations inhibits activity and, in parallel, detaches a 9 kDa polypeptide from PS II. These results suggest that the 9 kDa polypeptide is essential for PS II activity, and that it is bound to PS II primarily by hydrophobic interactions that are strengthened in vitro by glycerol. The 9 kDa polypeptide is distinct from cytochrome b-559 and does not appear to be associated with manganese or with the calcium or chloride requirements for oxygen evolution
Differential expression of Axl and Gas6 in renal cell carcinoma reflecting tumor advancement and survival
PURPOSE: Overexpression of the receptor tyrosine kinase Axl is implicated in several cancers. Therefore, we conducted this study to determine the expression of Axl and its ligand Gas6 in various renal cell carcinoma (RCC) types and in oncocytoma. EXPERIMENTAL DESIGN: Real-time quantitative reverse transcription-PCR was used to quantify tumor mRNA levels for Axl and Gas6 in a cohort (n = 221) of RCC patients. Serum levels of soluble sAxl and Gas6 proteins were measured using specific ELISA assays (n = 282). The presence of Axl protein in tumor tissue was evaluated by immunohistochemistry (n = 294). Results were correlated to tumor-associated variables, clinical biochemical tests, and patient survival. RESULTS: Tumor Axl mRNA levels correlated independently to survival when assessed against tumor stage and grade. In the study group, the median cancer-specific survival of all RCC patients during 307 months of follow-up was 55 months (confidence interval, +/-40.4). The 25% of patients with lowest tumor Axl mRNA levels had significantly better survival than the rest (P = 0.0005), with 70% of the patients still alive at the end of follow-up. In contrast, in patients with medium-high Axl mRNA, only 25% were alive at the end of follow-up. Tumor Gas6 mRNA levels correlated to survival, tumor-associated variables, and disease severity as did serum levels of soluble sAxl and Gas6 protein. However, no correlation between Axl protein in tumor tissue and survival was found. CONCLUSIONS: Axl and Gas6 expression in RCC are associated with tumor advancement and patient survival. In particular, low tumor Axl mRNA levels independently correlated with improved survival
A Statistical DOI Estimation Algorithm for a SiPM-Based Clinical SPECT Insert
A prototype clinical brain SPECT insert has been designed for use in simultaneous SPECT/MRI. The system utilises novel slit-slat collimators which, like pinhole collimators, suffers from parallax errors due to the large incident angle of photons. A statistical algorithm has been developed to determine the depth-of-interaction (DOI) with a view to improving image performance. The importance of DOI correction was demonstrated using Monte Carlo simulation. This simulation also indicated that 4 DOI layers (3×1.5 mm+3.5 mm) may be sufficient. The improvement in event localisation was demonstrated on a single detector before implementing the algorithm on the full clinical prototype where some limitations in event localisation in layers close to the readout plane were observed. Nevertheless DOI enabled the rejection of poorly localised events with improved resolution in reconstructed line sources
Impact of DOI in a clinical SPECT/MRI system:asimulation study
A novel SPECT/MRI scanner has been modelled and tested here using Monte Carlo simulation software, SIMIND. The INSERT SPECT/MRI system faces challenges with event reconstruction due to photon depth of interaction. The novel SPECT system is subject to parallax errors due to its crystal size and slit aperture collimator. We present a simple measure of the DOI errors through SIMIND experiments; by modelling the DOI layers we are able to improve the reconstruction of projection data in the INSERT scanner. A set of capillary phantoms are simulated to explore the impact of DOI on the resolution of the scanner and establish corrections in the system's reconstruction
Conferencing otherwise: a feminist new materialist writing experiment
This paper attempts to reconfigure hegemonic framings of ‘the academic conference’ and thereby offer a means to (re-)encounter the spatial, temporal and affective forces that conferences generate, differently. We are a geographically dispersed but multiply entangled group of academic researchers united by theoretical fault lines within our work that seek to ask what if (Haraway, 2016) and what else (Manning, 2016). This ‘what if’ and ‘what else’ thinking has manifested in experimental and subversive doings otherwise at a series of academic conferences. The storying practices presented in this paper were made possible by the vital materialism (Bennett, 2010) of a shared google.doc. It was within this virtual environment that we attempted to weave diffractive accounts of what conferencing otherwise produces. This writing experiment offers a series of speculative provocations and counter-provocations to ask what else does conferencing make possible. This article is an invitation to the reader to plunge in and wallow (Taylor, 2016) within the speculative accounts which ensue and to contemplate the possibilities of breaking free from sedimented ways of neoliberal conferencing
Systematic review of perioperative and quality-of-life outcomes following surgical management of localised renal cancer
UCAN Cancer Charity (www.ucanhelp.org.uk) and MacMillan Cancer Charity (www.macmillan.org.uk) helped design and conduct the study.Peer reviewedPostprin
An AARS variant as the likely cause of Swedish type hereditary diffuse leukoencephalopathy with spheroids
Swedish type Hereditary Diffuse Leukoencephalopathy with Spheroids (HDLS-S) is a severe adult-onset leukoencephalopathy with the histopathological hallmark of neuraxonal degeneration with spheroids, described in a large family with a dominant inheritance pattern. The initial stage of the disease is dominated by frontal lobe symptoms that develop into a rapidly advancing encephalopathy with pyramidal, deep sensory, extrapyramidal and optic tract symptoms. Median survival is less than 10 years. Recently, pathogenic mutations in CSF1R were reported in a clinically and histologically similar leukoencephalopathy segregating in several families. Still, the cause of HDLS-S remained elusive since its initial description in 1984, with no CSF1R mutations identified in the family. Here we update the original findings associated with HDLS-S after a systematic and recent assessment of several family members. We also report the results from exome sequencing analyses indicating the p.Cys152Phe variant in the alanyl tRNA synthetase (AARS) gene as the probable cause of this disease. The variant affects an amino acid located in the aminoacylation domain of the protein and does not cause differences in splicing or expression in the brain. Brain pathology in one case after 10 years of disease duration showed the end stage of the disease to be characterized by widespread liquefaction of the white matter leaving only some macrophages and glial cells behind the centrifugally progressing front. These results point to AARS as a candidate gene for rapidly progressing adult-onset CSF1R-negative leukoencephalopathies
- …