1,027 research outputs found
Effects of Hydrogen Plasma Treatment on the Electrical Behavior of Solution-Processed ZnO Thin Films.
In this study, the effect of atmospheric hydrogen plasma treatment on the in-plane conductivity of solution-processed zinc oxide (ZnO) in various environments is reported. The hydrogen-plasma-treated and untreated ZnO films exhibited ohmic behavior with room-temperature in-plane conductivity in a vacuum. When the untreated ZnO film was exposed to a dry oxygen environment, the conductivity rapidly decreased, and an oscillating current was observed. In certain cases, the thin film reversibly 'switched' between the high- and low-conductivity states. In contrast, the conductivity of the hydrogen-plasma-treated ZnO film remained nearly constant under different ambient conditions. We infer that hydrogen acts as a shallow donor, increasing the carrier concentration and generating oxygen vacancies by eliminating the surface contamination layer. Hence, atmospheric hydrogen plasma treatment could play a crucial role in stabilizing the conductivity of ZnO films
On the Origin of Near-Infrared Extragalactic Background Light Anisotropy
Extragalactic background light (EBL) anisotropy traces variations in the
total production of photons over cosmic history, and may contain faint,
extended components missed in galaxy point source surveys. Infrared EBL
fluctuations have been attributed to primordial galaxies and black holes at the
epoch of reionization (EOR), or alternately, intra-halo light (IHL) from stars
tidally stripped from their parent galaxies at low redshift. We report new EBL
anisotropy measurements from a specialized sounding rocket experiment at 1.1
and 1.6 micrometers. The observed fluctuations exceed the amplitude from known
galaxy populations, are inconsistent with EOR galaxies and black holes, and are
largely explained by IHL emission. The measured fluctuations are associated
with an EBL intensity that is comparable to the background from known galaxies
measured through number counts, and therefore a substantial contribution to the
energy contained in photons in the cosmos.Comment: 65 pages, 29 figures, Published in Science Nov 7 2014 (includes
supplementary material
A prospective study to assess the value of MMP-9 in improving the appropriateness of urgent referrals for colorectal cancer
Background
Bowel cancer is common and is a major cause of death. Most people with bowel symptoms who meet the criteria for urgent referral to secondary care will not be found to have bowel cancer, and some people who are found to have cancer will have been referred routinely rather than urgently. If general practitioners could better identify people who were likely to have bowel cancer or conditions that may lead to bowel cancer, the pressure on hospital clinics may be reduced, enabling these patients to be seen more quickly. Increased levels of an enzyme called matrix metalloproteinase 9 (MMP-9) have been found to be associated with such conditions, and this can be measured from a blood sample. This study aims to find out whether measuring MMP-9 levels could improve the appropriateness of urgent referrals for patients with bowel symptoms.
Methods
People aged 18 years or older referred to a colorectal clinic will be asked to complete a questionnaire about symptoms, recent injuries or chronic illnesses (these can increase the level of matrix metalloproteinases) and family history of bowel cancer. A blood sample will be taken from people who consent to take part to assess MMP-9 levels, and the results of examination at the clinic and/or investigations arising from the clinic visit will be collected from hospital records. The accuracy of MMP-9 will be assessed by comparing the MMP-9 level with the resulting diagnosis. The combination of factors (e.g. symptoms and MMP-9 level) that best predict a diagnosis of malignancy (invasive disease or polyps) will be determined.
Discussion
Although guidelines are in place to facilitate referrals to colorectal clinics, symptoms alone do not adequately distinguish people with malignancy from people with benign conditions. This study will establish whether MMP-9 could assist this process. If this were the case, measurement of MMP-9 levels could be used by general practitioners to assist in the identification of people who were most likely to have bowel cancer or conditions that may lead to bowel cancer, and who should, therefore, be referred most urgently to secondary car
KMT-2016-BLG-1107: A New Hollywood-Planet Close/Wide Degeneracy
We show that microlensing event KMT-2016-BLG-1107 displays a new type of
degeneracy between wide-binary and close-binary Hollywood events in which a
giant-star source envelops the planetary caustic. The planetary anomaly takes
the form of a smooth, two-day "bump" far out on the falling wing of the light
curve, which can be interpreted either as the source completely enveloping a
minor-image caustic due to a close companion with mass ratio , or
partially enveloping a major-image caustic due to a wide companion with
. The best estimates of the companion masses are both in the planetary
regime ( and ) but differ by an even larger factor than the mass ratios due to
different inferred host masses. We show that the two solutions can be
distinguished by high-resolution imaging at first light on next-generation
("30m") telescopes. We provide analytic guidance to understand the conditions
under which this new type of degeneracy can appear.Comment: 23 pages, 7 figures, accepted for publication in A
KMT-2018-BLG-1990Lb: A Nearby Jovian Planet From A Low-Cadence Microlensing Field
We report the discovery and characterization of KMT-2018-BLG-1990Lb, a Jovian
planet orbiting a late M dwarf
, at a distance
(D_L=1.23_{-0.43}^{+1.06}\,\kpc), and projected at times the
snow line distance, i.e., a_{\rm snow}\equiv 2.7\,\au (M/M_\odot), This is
the second Jovian planet discovered by KMTNet in its low cadence () fields, demonstrating that this population will be well
characterized based on survey-only microlensing data.Comment: 24 pages, 7 figures, 4 table
The significance of hazardous chemicals in wastewater treatment works effluents
This is the post-print version of the final paper published in Science of The Total Environment. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2012 Elsevier B.V.The advent of increasingly stringent and wider ranging European Union legislation relating to water and the environment has required regulators to assess compliance risk and to respond by formulating appropriate pollution control measures. To support this process the UK Water Industry has completed a national Chemicals Investigation Programme (CIP), to monitor over 160 wastewater treatment works (WwTWs) for 70 determinands. Final effluent concentrations of zinc, polynuclear aromatic hydrocarbons (fluoranthene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene), “penta” congeners (BDEs) 47 and 99, tributyltin, triclosan, erythromycin, oxytetracycline, ibuprofen, propranolol, fluoxetine, diclofenac, 17β-estradiol and 17α-ethinyl estradiol exceeded existing or proposed Environmental Quality Standards (EQSs) in over 50% of WwTWs. Dilution by receiving water might ensure compliance with EQSs for these chemicals, apart from the BDEs. However, in some cases there will be insufficient dilution to ensure compliance and additional management options may be required
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Mainstreaming domestic and gender-based violence into sociology and the criminology of violence
Sociological and criminological views of domestic and gender-based violencegenerally either dismiss it as not worthy of consideration, or focus on specificgroups of offenders and victims (male youth gangs, partner violence victims). Inthis paper, we take a holistic approach to violence, extending the definition fromthat commonly in use to encompass domestic violence and sexual violence. Weoperationalize that definition by using data from the latest sweep of the CrimeSurvey for England and Wales. By so doing, we identify that violence is currentlyunder-measured and ubiquitous; that it is gendered, and that other forms of violence (family violence, acquaintance violence against women) are equally ofconcern. We argue that violence studies are an important form of activity forsociologists
KMT-2018-BLG-1292: A Super-Jovian Microlens Planet in the Galactic Plane
We report the discovery of KMT-2018-BLG-1292Lb, a super-Jovian planet orbiting an F or G dwarf , which lies physically within {\cal O}(10\,\pc) of the
Galactic plane. The source star is a heavily extincted luminous
giant that has the lowest Galactic latitude, , of any planetary
microlensing event. The relatively blue blended light is almost certainly
either the host or its binary companion, with the first explanation being
substantially more likely. This blend dominates the light at band and
completely dominates at and bands. Hence, the lens system can be probed
by follow-up observations immediately, i.e., long before the lens system and
the source separate due to their relative proper motion. The system is well
characterized despite the low cadence -- of
observations and short viewing windows near the end of the bulge season. This
suggests that optical microlensing planet searches can be extended to the
Galactic plane at relatively modest cost.Comment: 35 pages, 3 Tables, 8 figure
Outcome of index upper gastrointestinal endoscopy in patients presenting with dysphagia in a tertiary care hospital-A 10 years review
<p>Abstract</p> <p>Background</p> <p>Patients with malignant tumours of the upper gastrointestinal tract tumours exhibit important alarm symptoms such as dysphagia that warrant clinical investigations. An endoscopic examination of the upper gastrointestinal tract will be required in most cases. This study evaluates the diagnostic potential of index endoscopy in a random population of patients with dysphagia.</p> <p>Methods</p> <p>This is a retrospective analysis of prospectively collected data over 10 years. Patients with previous endoscopic evaluation or upper gastrointestinal pathology were excluded from the study. Data was analysed to see the number and frequency of abnormal findings in upper gastrointestinal tract, and their significance in relation to the presenting symptoms.</p> <p>Results</p> <p>Total number of index endoscopies was 13, 881. 913 patients were included in the study including 465 males (age range: 17–92 years, median: 55 years) and 448 females (age range: 18–100, median: 59 years), with male to female ratio of 1.04: 1. Oesophagus was abnormal in 678 cases (74%) and biopsies were taken in 428 patients (47%). Superficial oesophagitis, Barrett's oesophagus, oesophageal cancer, and oesophageal ulcer were main histological findings. Age more than 50 years and weight loss were significant predictors of oesophageal cancer (p < 0.0001). Male gender, heartburn, epigastric pain, weight loss and vomiting were significantly related to Barrett's oesophagus. A total of 486 gastric and 56 duodenal biopsies were also taken. There were 20 cases of gastric adenocarcinoma.</p> <p>Conclusion</p> <p>OGD is an effective initial investigation to assess patients with dysphagia, especially males above the age of 50 years. Patients may be started on treatment or referred for further investigations, for example, a barium meal in the absence of any anatomical abnormality.</p
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