1,199 research outputs found
Photoelectrochemical Hydrogen Evolution Using Si Microwire Arrays
Arrays of B-doped p-Si microwires, diffusion-doped with P to form a radial n+ emitter and subsequently coated with a 1.5-nm-thick discontinuous film of evaporated Pt, were used as photocathodes for H_2 evolution from water. These electrodes yielded thermodynamically based energy-conversion efficiencies >5% under 1 sun solar simulation, despite absorbing less than 50% of the above-band-gap incident photons. Analogous p-Si wire-array electrodes yielded efficiencies <0.2%, largely limited by the low photovoltage generated at the p-Si/H_2O junction
Mid-Infrared Images of Stars and Dust in Irregular Galaxies
We present mid-infrared to optical properties of 22 representative irregular
galaxies: 18 Im, 3 BCDs, and one Sm. The mid-IR is based on images from the
Spitzer Space Telescope archives. The 3.6 and 4.5 micron bands and the UBVJHK
images are used to examine disk morphology and the integrated and azimuthally
averaged magnitudes and colors of stars. The non-stellar contribution to the
4.5 micron images is used to trace hot dust. The 5.8 and 8.0 micron images
reveal emission from hot dust and PAHs, and both may contribute to these
passbands, although we refer to the non-stellar emission as PAH emission. We
compare the 8.0 micron images to Halpha. Im galaxies have no hidden bars, and
those with double-exponential optical light profiles have the same at mid-IR.
Most galaxies have similar optical mid-IR scale lengths. Four galaxies have
super star clusters that are not visible at optical bands. Galaxies with higher
area-normalized star formation rates have more dust and PAH emission relative
to starlight. Hot dust and PAH emission is found mostly in high surface
brightness HII regions, implying that massive stars are the primary source of
heating. Galaxies with intense, wide-spread star formation have more extended
PAH emssion. The ratio of PAH to Halpha emission is not constant on small
scales. PAHs are associated with shell and giant filaments, so they are not
destroyed during shell formation.Comment: To be published in AJ Available from
ftp.lowell.edu/pub/dah/papers/ira
Prevalence of drug-drug interactions in oncology patients enrolled on National Clinical Trials Network oncology clinical trials
Abstract
Background
Drug-drug interactions (DDIs) in subjects enrolling in clinical trials can impact not only safety of the patient but also study drug outcomes and data validity. This makes it critical to adequately screen and manage DDIs. The study objective was to determine the prevalence of DDIs involving study medications in subjects enrolling in National Clinical Trials Network (NCTN) clinical trials at a single institution. DDIs were evaluated based on study protocol recommendations for concomitant medication use (i.e. exclude, avoid or use caution), screening via DDI tool, and pharmacist review.
Methods
Subjects enrolled in NCTN trials of commercially available agents between January 2013 and August 2017 were included if a complete medication list was available. Complete medication lists were collected from the date of enrollment or the next available date then screened utilizing protocol guidance and the DDI screening tool, Lexicomp® Drug Interactions (Wolters Kluwer, Hudson, OH). Interactions were reviewed for clinical relevance: defined as a DDI that would require a medication change to ensure study agent safety and efficacy at enrollment.
Results
One hundred and twenty-eight subjects enrolled in 35 clinical trials were included. Protocol guidance detected 15 unique DDI pairs that should be avoided or used with caution in 10.2% (13/128) of subjects. The majority of these subjects did not have a clinically relevant DDI (69.2%, 9/13) based on pharmacist review. Lexicomp® detected moderate to major DDIs in 24.2% (31/128) of subjects, with 9.4% (12/128) having a clinically relevant DDI.
Conclusions
This study confirms a high prevalence of DDIs present in subjects enrolling in oncology clinical trials. Further efforts should be made to improve methods to detect and manage DDIs in patients enrolling on clinical trials to ensure patient safety and trial data validity.https://deepblue.lib.umich.edu/bitstream/2027.42/146516/1/12885_2018_Article_5076.pd
Prehospital use of plasma in traumatic hemorrhage (The PUPTH Trial): study protocol for a randomised controlled trial
Background Severe traumatic injury and haemorrhagic shock are frequently associated with disruptions of coagulation function (such as trauma-induced coagulopathy TIC) and activation of inflammatory cascades. These pathologies may be exacerbated by current standard of care resuscitation protocols. Observational studies suggest early administration of plasma to severely-injured haemorrhaging patients may correct TIC, minimise inflammation, and improve survival. The proposed randomised clinical trial will evaluate the clinical effectiveness of pre-hospital plasma administration compared with standard- of-care crystalloid resuscitation in severely-injured patients with major traumatic haemorrhage. Methods/design This is a prospective, randomized, open-label, non-blinded trial to determine the effect of pre-hospital administration of thawed plasma (TP) on mortality, morbidity, transfusion requirements, coagulation, and inflammatory response in severely-injured bleeding trauma patients. Two hundred and ten eligible adult trauma patients will be randomised to receive either two units of plasma, to be administered in-field, vsstandard of care normal saline (NS). Main analyses will compare subjects allocated to TP to those allocated to NS, on an intention-to-treat basis. Primary outcome measure is all-cause 30-day mortality. Secondary outcome measures include coagulation and lipidomic/pro-inflammatory marker responses, volume of resuscitation fluids (crystalloid, colloid) and blood products administered, and major hospital outcomes (e.g. incidence of MSOF, length of ICU stay, length of hospital stay). Discussion This study is part of a US Department of Defense (DoD)-funded multi-institutional investigation, conducted independently of, but in parallel with, the University of Pittsburgh and University of Denver. Demonstration of significant reductions in mortality and coagulopathic/inflammatory-related morbidities as a result of pre-hospital plasma administration would be of considerable clinical importance for the management of haemorrhagic shock in both civilian and military populations. Trial registration ClinicalTrials.gov: NCT02303964 on 28 November 201
Predictors and outcomes of crossover to surgery from physical therapy for meniscal tear and osteoarthritis a randomized trial comparing physical therapy and surgery
BACKGROUND: Arthroscopic partial meniscectomy (APM) combined with physical therapy (PT) have yielded pain relief similar to that provided by PT alone in randomized trials of subjects with a degenerative meniscal tear. However, many patients randomized to PT received APM before assessment of the primary outcome. We sought to identify factors associated with crossing over to APM and to compare pain relief between patients who had crossed over to APM and those who had been randomized to APM. METHODS: We used data from the MeTeOR (Meniscal Tear in Osteoarthritis Research) Trial of APM with PT versus PT alone in subjects ≥45 years old who had mild-to-moderate osteoarthritis and a degenerative meniscal tear. We assessed independent predictors of crossover to APM among those randomized to PT. We also compared pain relief at 6 months among those randomized to PT who crossed over to APM, those who did not cross over, and those originally randomized to APM. RESULTS: One hundred and sixty-four subjects were randomized to and received APM and 177 were randomized to PT, of whom 48 (27%) crossed over to receive APM in the first 140 days after randomization. In multivariate analyses, factors associated with a higher likelihood of crossing over to APM among those who had originally been randomized to PT included a baseline Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Score of ≥40 (risk ratio [RR] = 1.99; 95% confidence interval [CI] = 1.00, 3.93) and symptom duration of <1 year (RR = 1.74; 95% CI = 0.98, 3.08). Eighty-one percent of subjects who crossed over to APM and 82% of those randomized to APM had an improvement of ≥10 points in their pain score at 6 months, as did 73% of those who were randomized to and received only PT. CONCLUSIONS: Subjects who crossed over to APM had presented with a shorter symptom duration and greater baseline pain than those who did not cross over from PT. Subjects who crossed over had rates of surgical success similar to those of the patients who had been randomized to surgery. Our findings also suggest that an initial course of rigorous PT prior to APM may not compromise surgical outcome. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence
Duty to Protect: Enhancing the Federal Framework to Prevent Childhood Lead Poisoning and Exposure to Environmental Harm
Scientific evidence indisputably demonstrates that lead poisoning causes permanent neurological damage and numerous co-morbidities for children and adults. Exposure to lead hazards irreversibly harms individuals and, left unchecked, can devastate communities into the future. In recognition of these threats, the President\u27s Task Force on Environmental Health Risks and Safety Risks to Children (Task Force) was established by Executive Order in 1997. The original Task Force created the first coordinated federal response to eliminate childhood lead poisoning in the United States and set an ambitious ten-year timeline to achieve its goals of prevention, treatment, research, and progress management
Duty to Protect: Enhancing the Federal Framework to Prevent Childhood Lead Poisoning and Exposure to Environmental Harm
Scientific evidence indisputably demonstrates that lead poisoning causes permanent neurological damage and numerous co-morbidities for children and adults. Exposure to lead hazards irreversibly harms individuals and, left unchecked, can devastate communities into the future. In recognition of these threats, the President\u27s Task Force on Environmental Health Risks and Safety Risks to Children (Task Force) was established by Executive Order in 1997. The original Task Force created the first coordinated federal response to eliminate childhood lead poisoning in the United States and set an ambitious ten-year timeline to achieve its goals of prevention, treatment, research, and progress management. However, the most recent Task Force retreated from these bold goals. Rather than eliminating lead poisoning, in 2018 the Task Force sought merely to reduce it. This Article provides a comprehensive overview of the dangers of lead exposure, details the federal government\u27s evolving response to lead poisoning, and, for the first time, disseminates previously unpublished comments on Drafting a New Federal Strategy to Reduce Childhood Lead Exposures and Impacts, submitted to the Task Force in 2017, ahead of its most recent report. By providing these comments publicly, this Article creates a record of critical recommendations to the Task Force, provides best practices for the federal government\u27s response to lead poisoning, and encourages federal policymakers to take the necessary steps to meet the original goal of eradicating lead hazards and protecting children from lead poisoning
Health Justice Strategies to Eradicate Lead Poisoning: An Urgent Call to Safeguard Future Generations
Despite over a century of evidence that lead is a neurotoxin that causes irreparable harm, today, lead continues to pervade children\u27s environments and remains a constant threat to health and wellbeing. One in three homes across the United States housing children under the age of six has significant lead-based paint hazards that place occupants at risk of permanent neurological harm and lifelong poor health risks. Federal, state, and local governments must use a range of primary prevention strategies in order to fully eradicate the risks and protect children from lead poisoning. This Article provides a comprehensive examination of best practices for addressing lead poisoning and proposes urgent reform measures at the local and state levels. Successful interventions ultimately prioritize health justice strategies and rely on community ownership and cross-sector participation; dedicate significant resources and funding to completely eliminate lead in the environment; and prioritize primary prevention practices that identify lead-based paint hazards before children are exposed
The evolution of sex ratio distorter suppression affects a 25 cM genomic region in the butterfly Hypolimnas bolina
Open Access ArticleSymbionts that distort their host's sex ratio by favouring the production and survival of females are common in arthropods. Their presence produces intense Fisherian selection to return the sex ratio to parity, typified by the rapid spread of host 'suppressor' loci that restore male survival/development. In this study, we investigated the genomic impact of a selective event of this kind in the butterfly Hypolimnas bolina. Through linkage mapping, we first identified a genomic region that was necessary for males to survive Wolbachia-induced male-killing. We then investigated the genomic impact of the rapid spread of suppression, which converted the Samoan population of this butterfly from a 100:1 female-biased sex ratio in 2001 to a 1:1 sex ratio by 2006. Models of this process revealed the potential for a chromosome-wide effect. To measure the impact of this episode of selection directly, the pattern of genetic variation before and after the spread of suppression was compared. Changes in allele frequencies were observed over a 25 cM region surrounding the suppressor locus, with a reduction in overall diversity observed at loci that co-segregate with the suppressor. These changes exceeded those expected from drift and occurred alongside the generation of linkage disequilibrium. The presence of novel allelic variants in 2006 suggests that the suppressor was likely to have been introduced via immigration rather than through de novo mutation. In addition, further sampling in 2010 indicated that many of the introduced variants were lost or had declined in frequency since 2006. We hypothesize that this loss may have resulted from a period of purifying selection, removing deleterious material that introgressed during the initial sweep. Our observations of the impact of suppression of sex ratio distorting activity reveal a very wide genomic imprint, reflecting its status as one of the strongest selective forces in nature.Natural Environment Research Council (NERC
Self-reported Adherence with the Use of a Device in a Clinical Trial as Validated by Electronic Monitors: the VIBES Study
Background: Adherences to treatments that require a behavioral action often rely on self-reported recall, yet it is vital to determine whether real time self reporting of adherence using a simple logbook accurately captures adherence. The purpose of this study was to determine whether real time self-reported adherence is an accurate measurement of device usage during a clinical trial by comparing it to electronic recording. Methods: Using data collected from older adult men and women (N=135, mean age 82.3 yrs; range 66 to 98 yrs) participating in a clinical trial evaluating a vibrating platform for the treatment of osteoporosis, daily adherence to platform treatment was monitored using both self-reported written logs and electronically recorded radio-frequency identification card usage, enabling a direct comparison of the two methods over one year. Agreement between methods was also evaluated after stratification by age, gender, time in study, and cognition status. Results: The two methods were in high agreement (overall intraclass correlation coefficient = 0.96). The agreement between the two methods did not differ between age groups, sex, time in study and cognitive function. Conclusions: Using a log book to report adherence to a daily intervention requiring a behavioral action in older adults is an accurate and simple approach to use in clinical trials, as evidenced by the high degree of concordance with an electronic monitor
- …