Microstructural, Densitometric and Metabolic Variations in Bones from Rats with Normal or Altered Skeletal States

Background: High resolution μCT, and combined μPET/CT have emerged as non-invasive techniques to enhance or even replace dual energy X-ray absorptiometry (DXA) as the current preferred approach for fragility fracture risk assessment. The aim of this study was to assess the ability of µPET/CT imaging to differentiate changes in rat bone tissue density and microstructure induced by metabolic bone diseases more accurately than current available methods. Methods: Thirty three rats were divided into three groups of control, ovariectomy and vitamin-D deficiency. At the conclusion of the study, animals were subjected to glucose (18FDG) and sodium fluoride (Na18F) PET/CT scanning. Then, specimens were subjected to µCT imaging and tensile mechanical testing. Results: Compared to control, those allocated to ovariectomy and vitamin D deficiency groups showed 4% and 22% (significant) increase in 18FDG uptake values, respectively. DXA-based bone mineral density was higher in the vitamin D deficiency group when compared to the other groups (cortical bone), yet μCT-based apparent and mineral density results were not different between groups. DXA-based bone mineral density was lower in the ovariectomy group when compared to the other groups (cancellous bone); yet μCT-based mineral density results were not different between groups, and the μCT-based apparent density results were lower in the ovariectomy group compared to the other groups. Conclusion: PET and micro-CT provide an accurate three-dimensional measurement of the changes in bone tissue mineral density, as well as microstructure for cortical and cancellous bone and metabolic activity. As osteomalacia is characterized by impaired bone mineralization, the use of densitometric analyses may lead to misinterpretation of the condition as osteoporosis. In contrast, µCT alone and in combination with the PET component certainly provides an accurate three-dimensional measurement of the changes in both bone tissue mineral density, as well as microstructure for cortical and cancellous bone and metabolic activity

Electroexcitation of the Δ+ (1232) at Low Momentum Transfer

We report on new p(e, e\u27 p)π°. measurements at the Δ+(1232) resonance at the low momentum transfer region, where the mesonic cloud dynamics is predicted to be dominant and rapidly changing, offering a test bed for chiral effective field theory calculations. The new data explore the Q2 dependence of the resonant quadrupole amplitudes and for the first time indicate that the Electric and the Coulomb quadrupole amplitudes converge as Q2 -\u3e 0. The measurements of the Coulomb quadrupole amplitude have been extended to the lowest momentum transfer ever reached, and suggest that more than half of its magnitude is attributed to the mesonic cloud in this region. The new data disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The measurements indicate that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements

Comparison of Biochar Attained from Various Feedstocks for the Adsorption of Arsenic in Water

Water is a fundamental human right, yet in many developing countries, it is a luxury. Water shortages and polluted water have become routine for millions of Venezuelans in the last two decades due to a failing economy and infrastructure mismanagement. According to the World Health Organization, arsenic (As) is a worldwide pollutant. Though it occurs naturally, As is toxic and may cause chronic poisoning with prolonged exposure. An estimated 4.5 million individuals in Latin America are chronically exposed to high levels of As (\u3e50 g/L), some up to 2000 g/L. Biochar, a carbon-based material, effectively adsorbs and sequesters pollutants. However, the decisive argument for further investigation of this sustainable adsorbent is its production from locally available and inexpensive materials. Furthermore, due to its large surface area, biochar soaks up pollutants from water. This research evaluates the feasibility of using sustainable biochar to remove As from water. In this study, we selected various feedstocks, specifically sugarcane bagasse, peanut, and walnut shells, which are readily available biowaste in Venezuela. Each feedstock was pyrolyzed for a specific time and temperature under an inert (Ar) atmosphere to produce biochars. First, biochars were characterized using various techniques such as FTIR analysis, BET theory, SEM, and others. Then, comparative, temperature-controlled adsorption batch experiments were conducted to estimate the adsorption capacities of each biochar. Future research will focus on taking the highest As adsorbent and preparing a water filtration system that a small community could use, providing them with improved access to clean water.https://digitalscholarship.unlv.edu/durep_posters/1074/thumbnail.jp

Ignition sensitivity of solid fuel mixtures

Due to both environmental concerns and the depletion of the reserves of fossil fuels, alternative and more environmentally friendly fuels, such as biomass and waste products, are being considered for partial or full fossil fuel replacement. The main disadvantage of these products is their lower energy density compared to fossil fuels. To deal with this several heat and power generation facilities are co-firing fuel mixtures. These processes involve mixtures of flammable dusts whose ignitability and explosibility characteristics are not known and therefore present un-quantified safety risk to the new technologies. This study reports on these risks and on the reactivity characteristics of two and three components dust mixtures of coal/sewage-sludge/torrefied-wood-pellet. In particular chemical composition, ignition sensitivity parameters (including minimum ignition energy, minimum ignition temperature on a layer, minimum explosive concentration) and flame speed have been determined. In all cases the measured parameters for the mixtures were within the range defined by the lower and upper value of the constituent. However, the expected values do not agree with the experimentally obtained ones, providing more relaxed values than the ones needed on this facilities

Search for a new gauge boson in the A′A' Experiment (APEX)

We present a search at Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling $\alpha'$ to electrons. Such a particle $A'$ can be produced in electron-nucleus fixed-target scattering and then decay to an $e^+e^-$ pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175--250 MeV, found no evidence for an $A'\to e^+e^-$ reaction, and set an upper limit of $\alpha'/\alpha \simeq 10^{-6}$. Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.Comment: 5 pages, 5 figures, references adde

Electroexcitation of the Δ+(1232)\Delta^{+}(1232) at low momentum transfer

We report on new p$(e,e^\prime p)\pi^\circ$ measurements at the $\Delta^{+}(1232)$ resonance at the low momentum transfer region. The mesonic cloud dynamics is predicted to be dominant and rapidly changing in this kinematic region offering a test bed for chiral effective field theory calculations. The new data explore the low $Q^2$ dependence of the resonant quadrupole amplitudes while extending the measurements of the Coulomb quadrupole amplitude to the lowest momentum transfer ever reached. The results disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The reported measurements suggest that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements

Protein kinetics of superoxide dismutase-1 in familial and sporadic amyotrophic lateral sclerosis

OBJECTIVE: Accumulation of misfolded superoxide dismutase-1 (SOD1) is a pathological hallmark of SOD1-related amyotrophic lateral sclerosis (ALS) and is observed in sporadic ALS where its role in pathogenesis is controversial. Understanding in vivo protein kinetics may clarify how SOD1 influences neurodegeneration and inform optimal dosing for therapies that lower SOD1 transcripts. METHODS: We employed stable isotope labeling paired with mass spectrometry to evaluate in vivo protein kinetics and concentration of soluble SOD1 in cerebrospinal fluid (CSF) of SOD1 mutation carriers, sporadic ALS participants and controls. A deaminated SOD1 peptide, SDGPVKV, that correlates with protein stability was also measured. RESULTS: In participants with heterozygous SOD1 INTERPRETATION: These results highlight the ability of stable isotope labeling approaches and peptide deamidation to discern the influence of disease mutations on protein kinetics and stability and support implementation of this method to optimize clinical trial design of gene and molecular therapies for neurological disorders. TRIAL REGISTRATION: Clinicaltrials.gov: NCT03449212

Development and evaluation of a web-based breast cancer cultural competency course for primary healthcare providers

<p>Abstract</p> <p>Background</p> <p>To develop and evaluate a continuing medical education (CME) course aimed at improving healthcare provider knowledge about breast cancer health disparities and the importance of cross-cultural communication in provider-patient interactions about breast cancer screening.</p> <p>Methods</p> <p>An interactive web-based CME course was developed and contained information about breast cancer disparities, the role of culture in healthcare decision making, and demonstrated a model of cross-cultural communication. A single group pre-/post-test design was used to assess knowledge changes. Data on user satisfaction was also collected.</p> <p>Results</p> <p>In all, 132 participants registered for the CME with 103 completing both assessments. Differences between pre-/post-test show a significant increase in knowledge (70% vs. 94%; p < .001). Ninety-five percent of participants agreed that the web based training was an appropriate tool to train healthcare providers about cultural competency and health disparities.</p> <p>Conclusion</p> <p>There was an overall high level of satisfaction among all users. Users felt that learning objectives were met and the web-based format was appropriate and easy to use and suggests that web-based CME formats are an appropriate tool to teach cultural competency skills. However, more information is needed to understand how the CME impacted practice behaviors.</p