Magnetically Catalyzed Fusion

We calculate the reaction cross-sections for the fusion of hydrogen and deuterium in strong magnetic fields as are believed to exist in the atmospheres of neutron stars. We find that in the presence of a strong magnetic field (B \gsim 10^{12}G), the reaction rates are many orders of magnitude higher than in the unmagnetized case. The fusion of both protons and deuterons are important over a neutron star's lifetime for ultrastrong magnetic fields ($B \sim 10^{16}$G). The enhancement may have dramatic effects on thermonuclear runaways and bursts on the surfaces of neutron stars.Comment: 13 pages, 6 figure

Evaluation of a Liquid Amine System for Spacecraft Carbon Dioxide Control

The analytical and experimental studies are described which were directed toward the acquisition of basic information on utilizing a liquid amine sorbent for in use in a CO2 removal system for manned spacecraft. Liquid amine systems are successfully used on submarines for control of CO2 generated by the crew, but liquid amines were not previously considered for spacecraft applications due to lack of development of satisfactory rotary phase separators. Developments in this area now make consideration of liquid amines practical for spacecraft system CO2 removal. The following major tasks were performed to evaluate liquid amine systems for spacecraft: (1) characterization, through testing, of the basic physical and thermodynamic properties of the amine solution; (2) determination of the dynamic characteristics of a cocurrent flow absorber; and (3) evaluation, synthesis, and selection of a liquid amine system concept oriented toward low power requirements. A low weight, low power system concept was developed. Numerical and graphical data are accompanied by pertinent observations

Spectroscopic Constraints on the Surface Magnetic Field of the Accreting Neutron Star EXO 0748-676

Gravitationally redshifted absorption lines of Fe XXVI, Fe XXV, and O VIII were inferred recently in the X-ray spectrum of the bursting neutron star EXO 0748-676. We place an upper limit on the stellar magnetic field based on the iron lines. The oxygen absorption feature shows a multiple component profile that is consistent with Zeeman splitting in a magnetic field of ~(1-2)x10^9 gauss, and for which the corresponding Zeeman components of the iron lines are expected to be blended together. In other systems, a field strength >5x10^{10} gauss could induce a blueshift of the line centroids that would counteract gravitational redshift and complicate the derivation of constraints on the equation of state of the neutron star.Comment: 5 pages, submitted to Phys. Rev. Let

Lithium in strong magnetic fields

The electronic structure of the lithium atom in a strong magnetic field 0 <= gamma <= 10 is investigated. Our computational approach is a full configuration interaction method based on a set of anisotropic Gaussian orbitals that is nonlinearly optimized for each field strength. Accurate results for the total energies and one-electron ionization energies for the ground and several excited states for each of the symmetries ^20^+, ^2(-1)^+, ^4(-1)^+, ^4(-1)^-, ^2(-2)^+, ^4(-2)^+, $^4(-3)^{+}$ are presented. The behaviour of these energies as a function of the field strength is discussed and classified. Transition wave lengths for linear and circular polarized transitions are presented as well.Comment: 12 pages, 13 figures, accepted for publication in Phys. Rev.

Tetrachloroethylene-contaminated drinking water and the risk of breast cancer.

We conducted a population-based case-control study to evaluate the relationship between cases of breast cancer and exposure to tetrachloroethylene (PCE) from public drinking water ( n = 258 cases and 686 controls). Women were exposed to PCE when it leached from the vinyl lining of water distribution pipes. The relative delivered dose was estimated using an algorithm that accounted for residential history, water flow, and pipe characteristics. Only small increases in breast cancer risk were seen among ever-exposed women either when latency was ignored or when 5 to 15 years of latency was considered. No or small increases were seen among highly exposed women either when latency was ignored or when 5 years of latency was considered. However, the adjusted odds ratios (ORs) were more increased for highly exposed women when 7 and 9 years of latency, respectively, were considered (OR 1.5 95% CI 0.5-4.7 and OR 2.3, 95% CI 0.6-8.8 for the 75th percentile, and OR 2.7, 95% CI 0.4-15.8 and OR 7.6, 95% CI 0.9-161.3 for the 90th percentile). The number of highly exposed women was too small for meaningful analysis when more years of latency were considered. Because firm conclusions from these data are limited, we recently undertook a new study with a large number of more recently diagnosed cases

Decreasing Medical Device Related Tracheostomy Pressure Injuries with Hydroconductive Dressings

Aim: Medical device related pressure injuries (MDRPIs) are pressure injuries that result from prolonged exposure to a compressive force, tension, shear, or combination of all from a health care associated medical device. MDRPIs are negative hospital acquired patient outcomes that are costly to an organization. At Henry Ford Jackson Hospital (HFJH) there was an increase noted in MDRPIs from new tracheostomies in 2022: Quarter 1 2022: Two tracheostomy related MDRPIs (stage 2 and stage 3) Quarter 3 2022: Two tracheostomy related MDRPIs (both unstageable) The HFJH Falls and Pressure Injury Committee created a task force to investigate if the use of a hydroconductive dressing post tracheostomy placement would decrease MDRPIs compared to standard practice hydrocellular dressings.https://scholarlycommons.henryford.com/nursresconf2023/1002/thumbnail.jp

Artificial intelligence in commercial fracture detection products: a systematic review and meta-analysis of diagnostic test accuracy

Conventional radiography (CR) is primarily utilized for fracture diagnosis. Artificial intelligence (AI) for CR is a rapidly growing field aimed at enhancing efficiency and increasing diagnostic accuracy. However, the diagnostic performance of commercially available AI fracture detection solutions (CAAI-FDS) for CR in various anatomical regions, their synergy with human assessment, as well as the influence of industry funding on reported accuracy are unknown. Peer-reviewed diagnostic test accuracy (DTA) studies were identified through a systematic review on Pubmed and Embase. Diagnostic performance measures were extracted especially for different subgroups such as product, type of rater (stand-alone AI, human unaided, human aided), funding, and anatomical region. Pooled measures were obtained with a bivariate random effects model. The impact of rater was evaluated with comparative meta-analysis. Seventeen DTA studies of seven CAAI-FDS analyzing 38,978 x-rays with 8,150 fractures were included. Stand-alone AI studies (n=15) evaluated five CAAI-FDS; four with good sensitivities (>90%) and moderate specificities (80–90%) and one with very poor sensitivity (<60%) and excellent specificity (>95%). Pooled sensitivities were good to excellent, and specificities were moderate to good in all anatomical regions (n=7) apart from ribs (n=4; poor sensitivity / moderate specificity) and spine (n=4; excellent sensitivity / poor specificity). Funded studies (n=4) had higher sensitivity (+5%) and lower specificity (-4%) than non-funded studies (n=11). Sensitivity did not differ significantly between stand-alone AI and human AI aided ratings (p=0.316) but specificity was significantly higher the latter group (p<0.001). Sensitivity was significant lower in human unaided compared to human AI aided respectively stand-alone AI ratings (both p≤0.001); specificity was higher in human unaided ratings compared to stand-alone AI (p<0.001) and showed no significant differences AI aided ratings (p=0.316). The study demonstrates good diagnostic accuracy across most CAAI-FDS and anatomical regions, with the highest performance achieved when used in conjunction with human assessment. Diagnostic accuracy appears lower for spine and rib fractures. The impact of industry funding on reported performance is small

Cohesive property of magnetized neutron star surfaces: Computations and implications

The cohesive energy of condensed matter in strong magnetic fields is a fundamental quantity characterizing magnetized neutron star surfaces. The cohesive energy refers to the energy required to pull an atom out of the bulk condensed matter at zero pressure. Theoretical models of pulsar and magnetar magnetospheres depend on the cohesive properties of the surface matter in strong magnetic fields. For example, depending on the cohesive energy of the surface matter, an acceleration zone ("polar gap") above the polar cap of a pulsar may or may not form. Also, condensation of the neutron star surface, if it occurs, can significantly affect thermal emission from isolated neutron stars. We describe our calculations of the cohesive property of matter in strong magnetic fields, and discuss the implications of our results to the recent observations of neutron star surface emission as well as to the detection/non-detection of radio emission from magnetars.Comment: 12 pages, 4 figures. Minor changes to Author/Comments fields. To appear in Advances in Space Researc

Direct Immunosensor Design Based on the Electrochemical Reduction of 4-((4-Nitrophenyl) ethynyl) benzenethiol Monolayers

The synthesis and characterization of novel N-arylhydroxylamine-based molecular wires are described for use in the site-directed covalent immobilization of whole IgG antibodies onto gold electrode surfaces. The hydroxylamine, electrochemically generated in situ from reduction of the corresponding nitrobenzene, is stable under a wide range of solution conditions and reacts selectively with carbohydrate away from the antibody-binding site to allow the development of immunosensors with maximal activity. Cyclic voltammetric responses have shown a direct correlation between the structure and length of the molecular wire and its stability and concentration at the electrode surface