1,325 research outputs found
The National Ignition Facility Project
The mission of the National Ignition Facility is to achieve ignition and gain in ICF targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effect testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. This paper reviews the design, schedule and costs associated with the construction project
Factors contributing to the time taken to consult with symptoms of lung cancer: a cross-sectional study
<b>Objectives</b>: To determine what factors are associated with the time people take to consult with symptoms of lung cancer, with a focus on those from rural and socially deprived areas.
<b>Methods</b>: A cross-sectional quantitative interview survey was performed of 360 patients with newly diagnosed primary lung cancer in three Scottish hospitals (two in Glasgow, one in NE Scotland). Supplementary data were obtained from medical case notes. The main outcome measures were the number of days from (1) the date participant defined first symptom until date of presentation to a medical practitioner; and (2) the date of earliest symptom from a symptom checklist (derived from clinical guidelines) until date of presentation to a medical practitioner.
<b>Results</b>: 179 participants (50%) had symptoms for more than 14 weeks before presenting to a medical practitioner (median 99 days; interquartile range 31â381). 270 participants (75%) had unrecognised symptoms of lung cancer. There were no significant differences in time taken to consult with symptoms of lung cancer between rural and/or deprived participants compared with urban and/or affluent participants. Factors independently associated with increased time before consulting about symptoms were living alone, a history of chronic obstructive pulmonary disease (COPD) and longer pack years of smoking. Haemoptysis, new onset of shortness of breath, cough and loss of appetite were significantly associated with earlier consulting, as were a history of chest infection and renal failure.
<b>Conclusion</b>: For many people with lung cancer, regardless of location and socioeconomic status, the time between symptom onset and consultation was long enough to plausibly affect prognosis. Long-term smokers, those with COPD and/or those living alone are at particular risk of taking longer to consult with symptoms of lung cancer and practitioners should be alert to this
Theory of photoinduced charge transfer in weakly coupled donor-acceptor conjugated polymers: application to an MEH-PPV:CN-PPV pair
In a pair of coupled donor-acceptor conjugated polymer chains, it is possible
for an exciton photoexcited on either polymer to decay into a hole in the donor
polymer's valence band and an electron in the conduction band of the acceptor
polymer. We calculate the corresponding exciton decay rate and its dependence
on inter-polymer distance. For a pair of derivatives of poly(phenylene
vinylene), PPV, specifically poly[2-methoxy, 5-(2-ethyl-hexyloxy)-1, 4
PPV], MEH-PPV, and poly(2,5-hexyloxy -phenylene cyanovinylene), CN-PPV, at a
separation of 6 \AA the characteristic decay time is 2.2 ps, whereas at 4 \AA
it is fs.Comment: 9 pages, RevTeX, 4 PS files, to be published in a special issue of
Chem. Phy
The small x gluon and b\bar{b} production at the LHC
We study open b\bar{b} production at large rapidity at the LHC in an attempt
to pin down the gluon distribution at very low x. For the LHC energy of 7 TeV,
at next-to-leading order (NLO), there is a large factorization scale
uncertainty. We show that the uncertainty can be greatly reduced if events are
selected in which the transverse momenta of the two B-mesons balance each other
to some accuracy, that is |\vec p_{1T}+\vec p_{2T}| < k_0. This will fix the
scale \mu_F \simeq k_0, and will allow the LHCb experiment, in particular, to
study the x-behaviour of gluon distribution down to x ~ 10^{-5}, at rather low
scales, \mu ~ 2 GeV. We evaluate the expected cross sections using, for
illustrative purposes, various recent sets of Parton Distribution Functions.Comment: 13 pages, 5 figure
Radiodynamic therapy using TAT peptideâtargeted Verteporfinâencapsulated PLGA nanoparticles
Radiodynamic therapy (RDT) is a recent extension of conventional photodynamic therapy, in which visible/near infrared light irradiation is replaced by a well-tolerated dose of high-energy X-rays. This enables greater tissue penetration to allow non-invasive treatment of large, deep-seated tumors. We report here the design and testing of a drug delivery system for RDT that is intended to enhance intra- or peri-nuclear localization of the photosensitizer, leading to DNA damage and resulting clonogenic cell kill. This comprises a photosensitizer (Verteporfin, VP) incorporated into poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) that are surface-functionalized with a cell-penetrating HIV trans-activator of transcription (TAT) peptide. In addition to a series of physical and photophysical characterization studies, cytotoxicity tests in pancreatic (PANC-1) cancer cells in vitro under 4 Gy X-ray exposure from a clinical 6 MV linear accelerator (LINAC) showed that TAT targeting of the nanoparticles markedly enhances the effectiveness of RDT treatment, particularly when assessed by a clonogenic, i.e., DNA damage-mediated, cell kill.Sandhya Clement, Ayad G. Anwer, Layla Pires, Jared Campbell, Brian C. Wilson and Ewa M. Goldy
Elasticity-driven interaction between vortices in type-II superconductors
The contribution to the vortex lattice energy which is due to the
vortex-induced strains is calculated covering all the magnetic field range
which defines the vortex state. This contribution is compared with previously
reported ones what shows that, in the most part of the vortex state, it has
been notably underestimated until now. The reason of such underestimation is
the assumption that only the vortex cores induce strains. In contrast to what
is generally assumed, both core and non-core regions are important sources of
strains in high- superconductors.Comment: 10 pages, 1 figure, revtex
Emerging clinical applications in oncology for nonâinvasive multiâ and hyperspectral imaging of cell and tissue autofluorescence
OnlinePublHyperspectral and multispectral imaging of cell and tissue autofluorescence is an emerging technology in which fluorescence imaging is applied to biological materials across multiple spectral channels. This produces a stack of images where each matched pixel contains information about the sample's spectral properties at that location. This allows precise collection of molecularly specific data from a broad range of native fluorophores. Importantly, complex information, directly reflective of biological status, is collected without staining and tissues can be characterised in situ, without biopsy. For oncology, this can spare the collection of biopsies from sensitive regions and enable accurate tumour mapping. For in vivo tumour analysis, the greatest focus has been on oral cancer, whereas for ex vivo assessment head-and-neck cancers along with colon cancer have been the most studied, followed by oral and eye cancer. This review details the scope and progress of research undertaken towards clinical translation in oncology.Jared M. Campbell, Abbas Habibalahi, Shannon Handley, Adnan Agha, Saabah B. Mahbub, Ayad G. Anwer, Ewa M. Goldy
Automated pancreatic islet viability assessment for transplantation using bright-field deep morphological signature
Islets transplanted for type-1 diabetes have their viability reduced by warm ischemia, dimethyloxalylglycine (DMOG; hypoxia model), oxidative stress and cytokine injury. This results in frequent transplant failures and the major burden of patients having to undergo multiple rounds of treatment for insulin independence. Presently there is no reliable measure to assess islet preparation viability prior to clinical transplantation. We investigated deep morphological signatures (DMS) for detecting the exposure of islets to viability compromising insults from brightfield images. Accuracies ranged from 98 % to 68 % for; ROS damage, pro-inflammatory cytokines, warm ischemia and DMOG. When islets were disaggregated to single cells to enable higher throughput data collection, good accuracy was still obtained (83-71 %). Encapsulation of islets reduced accuracy for cytokine exposure, but it was still high (78 %). Unsupervised modelling of the DMS for islet preparations transplanted into a syngeneic mouse model was able to predict whether or not they would restore glucose control with 100 % accuracy. Our strategy for constructing DMS' is effective for the assessment of islet pre-transplant viability. If translated into the clinic, standard equipment could be used to prospectively identify non-functional islet preparations unable to contribute to the restoration of glucose control and reduce the burden of unsuccessful treatments.Abbas Habibalahi, Jared M. Campbell, Stacey N. Walters, Saabah B. Mahbub, Ayad G. Anwer, Shane T. Grey, Ewa M. Goldy
Clinical applications of nonâinvasive multi and hyperspectral imaging of cell and tissue autofluorescence beyond oncology
Hyperspectral and multispectral imaging of cell and tissue autofluorescence employs fluorescence imaging, without exogenous fluorophores, across multiple excitation/ emission combinations (spectral channels). This produces an image stack where each pixel (matched by location) contains unique information about the sample's spectral properties. Analysis of this data enables access to a rich, molecularly specific data set from a broad range of cell-native fluorophores (autofluorophores) directly reflective of biochemical status, without use of fixation or stains. This non-invasive, non-destructive technology has great potential to spare the collection of biopsies from sensitive regions. As both staining and biopsy may be impossible, or undesirable, depending on the context, this technology great diagnostic potential for clinical decision making. The main research focus has been on the identification of neoplastic tissues. However, advances have been made in diverse applicationsâincluding ophthalmology, cardiovascular health, neurology, infection, assisted reproduction technology and organ transplantation.Jared M. Campbell, Saabah B. Mahbub, Abbas Habibalahi, Adnan Agha, Shannon Handley, Ayad G. Anwer, Ewa M. Goldy
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