UNT Scholarly Works - 2,191 Matching Results
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- Experimental and Kinetic Modeling Study of Acetylene Oxidation at High Pressure
- Article describing a detailed chemical kinetic model for oxidation of acetylene at intermediate temperatures and high pressure that was developed and evaluated experimentally.
- Confinement of antiprotons in the electrostatic space charge of positrons in a model of the ALPHA antihydrogen trap
- This article details the equilibrium of a positron plasma in a model of the ALPHA apparatus that is computed using a finite-difference method. The positron plasma in the model extends to axial magnetic mirrors in absence of an octupole field. Formation of a three-dimensional electrostatic potential well is found to occur self-consistently. Well depths under various conditions are evaluated. Also, the equilibrium with an antiproton plasma confined in the potential well is computed.
- Artificially Structured Boundary for a high purity ion trap or ion source
- This article proposes a plasma enclosed by an Artificially Structured Boundary (ASB) as an alternative to existing ion source assemblies. In accelerator applications, many ion sources can have a limited lifetime or frequent service intervals due to sputtering and eventual degradation of the ion source assembly. Ions are accelerated towards the exit canal of positive ion sources, whereas, due to the biasing scheme, electrons or negative ions are accelerated towards the back of the ion source assembly.
- Simulation Of An Antihydrogen Gravity Experiment Utilizing Multiple Apertures
- The article presents an analytical model and a Monte Carlo simulation of an antihydrogen gravity experiment that would employ multiple apertures. The model was developed with the primary goal of reducing the experimental run time necessary to determine the direction of free fall acceleration for antimatter in the gravitational field of the Earth. The experiment would confine cryogenic antihydrogen plasma for producing antihydrogen (e.g., by three-body recombination).
- Electrostatic storage ring with focusing provided by the space charge of an electron plasma
- Article describes an electronic storage ring that employs the space charge of an electron plasma for focusing. An advantage of the present concept is that slow ions, or even a stationary ion plasma, can be confined. The concept employs an artificially structured boundary, which is defined at present as one that produces a spatially periodic static field such that the spatial period and range of the field are much smaller than the dimensions of a plasma or charged-particle beam that is confined by the field.
- Accelerator-based fusion with a low temperature target
- This article reports a study of a cold target with a high Fermi energy in light of recent research that points to a new phase of hydrogen, which is hypothesized to be related to metallic hydrogen. It has been shown that if the energy transfer between injected ions and target electrons is sufficiently small, net energy gain can be achieved. As such, the target is considered to be composed of nuclei and delocalized electrons.
- Classical trajectory Monte Carlo code for simulating ion beam focusing or defocusing with magnetic elements modeled as current loops or current lines
- Article describes a computational tool that can be used for designing magnetic focusing or defocusing systems. A fully three-dimensional classical trajectory Monte Carlo simulation has been developed.
- Dual levitated coils for antihydrogen production
- Article on theoretical and experimental efforts to use dual levitated coils to confine relatively large, cold, dense non-drifting recombining antihydrogen plasmas. The theoretical effort includes the development of a classical trajectory Monte Carlo simulation of confinement. The experimental effort includes levitation of a NdFeB permanent ring magnet, which produces a magnetic field that is qualitatively similar to the field that would be produced by the two coaxial superconducting magnetic coils.
- Antihydrogen Synthesis Via Magnetobound States of Protonium Within Proton-Positron-Antiproton Plasmas
- Article studies the possibility that antihydrogen can be synthesized via three body recombination involving magnetobound protonium through classical trajectory simulation. It has been previously reported that proton antiproton collisions can result in a correlated drift of the particles perpendicular to a magnetic field. While the two particles are in their correlated drift, they are referred to as a magnetobound protonium system. Possible three body recombination resulting in bound state antihydrogen is studied when a magnetobound protonium system encounters a positron.
- Effect of a finite antiproton mass on antihydrogen synthesis via magnetobound positronium within electron-positron-antiproton plasmas
- This article describes a study that was conducted to determine what would happen if a magnetobound positronium system encountered a finite-mass antiproton. The simulation incorporates a strong magnetic field (1 T) similar to that found within Penning traps. The simulation shows that with a finite-mass antiproton, the electron will be ejected from the system, and the positron is captured into a bound state with an antiproton thereby synthesizing antihydrogen.
- Magnetobound positronium and protonium
- This article investigates the formation of magnetobound positronium and protonium via classical trajectory simulations of binary point charge interactions in an external magnetic field. The results of computer simulations of the fully three-dimensional trajectories of classical and non-relativistic point charges with the same mass, equal charge magnitude, and opposite sign are reported. The simulations show the formation of magnetobound positronium and protonium. The results yield formation cross sections, which are compared to analytical expressions. Additionally, the results reveal that magnetobound states drift across magnetic field lines.
- Phase space of positron trajectories exiting a charged particle source through a magnetic field point cusp
- This article presents a configuration of magnetic fields using properties of cylindrically symmetric permanent magnets as a candidate to produce a high purity charged particle source or trap. Cylindrically symmetric hollow permanent magnets produce magnetic field point cusps on the axis of symmetry. A magnetic field point cusp reflects all particles that lie outside a narrow region of phase space, a region dependent on particle kinetic energies and on the magnetic field intensity.
- Giant cross-magnetic-field steps due to binary collisions between pair particles
- Article explores giant cross-magnetic-field steps which occur as a result of positron-electron collisions. Within a constant magnetic field (e.g., 1 T), a collision between a positron and an electron can result in a correlated drift across the magnetic field for a continuous range of impact parameters. Within this range, drift distances orders of magnitude larger than that associated with like-charge collisions were observed by computer simulation.
- Explicitly teaching five technical genres to English first-language adults in a multi-major technical writing course
- In this article, the author reports the effects of explicitly teaching five technical genres to English first-language students enrolled in a multi-major technical writing course. Previous experimental research has demonstrated the efficacy of explicitly teaching academic writing to English first-language adults, but no comparable study on technical writing exists.
- Measurements and Theoretical Predictions of Charge Exchange Cross Sections and Emission Spectra for O6+ with H2O, CO, CO2, CH4, N2, NO, N2O and Ar
- Article reports absolute CE cross sections for up to three exchanges of the O6+ ion with electrons from the comet/planetary gases H2O, CO, CO2, CH4, N2, NO, N2O and Ar.
- Cabo de hornos: Un crisol biogeográfico en la cumbre austral de américa
- Article discusses the history and the biodiversity of Cape Horn.
- A New Way to Understand and Address Women’s Health in the Context of Complex Systems: Self-organizing Criticality
- Article proposes applying concepts from nonlinear science developed and employed by physicists, economists, and meteorologists to women's health issues.
- What Can We Learn about Dispersion from the Conformer Surface of n-Pentane?
- Article describes study in which researchers mapped the torsional surface of n-pentane to 10-degree resolution at the CCSD(T)-F12 level near the basis set limit.
- Evidence for the Involvement of Electrical, Calcium and ROS Signaling in the Systemic Regulation of Non-Photochemical Quenching and Photosynthesis
- Article presents study in which pulse amplitude-modulated Chl fluorescence imaging and surface electrical potential measurements accompanied by pharmacological treatments were employed to study stimuli-induced electrical signals in leaves from a broad range of plant species and in Arabidopsis thaliana mutants.
- EMOTION-III Model: A Theoretical Framework for Social Empathic Emotions in Autonomous Control Systems
- In this article, a theoretical model of social empathic emotion is derived based on the principles of survival by extending the maximization of self-gains to include others as an extended-self. This extended-self model of optimization for survival provides the computational mechanisms in the optimization process to maximize self-gains without minimizing the gains (or maximizing losses) for the other individuals. Thus, it can resolve conflicts in a competitive environment, and change the social dynamics into a cooperative interaction instead.
- Space-charge-based electrostatic plasma confinement involving relaxed plasma species
- In this article, a numerical study is reported on the equilibrium properties of a surface-emitted or edge-confined non-drifting plasma. A self-consistent finite-differences evaluation of the electrostatic potential is carried out for a non-neutral plasma that follows a Boltzmann density distribution.
- Targeting the PI3K/Akt signaling pathway in gastric carcinoma: A reality for personalized medicine?
- Article reviews the common dysregulation of phosphatidylinositol-3 kinases (PI3K)/Akt/mTOR pathway in gastric cancer (GC) and the various types of single or dual pathway inhibitors under development that might have a superior role in GC treatment.
- Electrical Properties of Tin Selenide Under High-Pressure
- The article investigates the pressure-induced phase transitions in tin selenide (SnSe). using the first-principles density functional calculations. The experimental results in the nanostructured SnSe revealed a phase transition at 4 GPa whereas that in the well-crystallized samples showed at 10 GPa.
- A blood screening test for Alzheimer's disease
- Article describes study examining the positive and negative predictive values of an Alzheimer's disease (AD) blood test if implemented in primary care.
- Crystal structure of (3E,5E)-3,5-bis[4-(diethylazaniumyl)benzylidene]-1-methyl-4-oxopiperidin-1-ium trichloride dihydrate: a potential biophotonic material
- Article provides a detailed description of the crystal structure of (3E,5E)-3,5-bis[4-(diethylazaniumyl)benzylidene]-1-methyl-4-oxopiperidin-1-ium trichloride dihydrate
- Crystal structure of bis(acetonitrile-κN)(4,4′-di-tert-butyl-2,2′-bipyridine-κ2N,N′)platinum(II) bis(tetrafluoridoborate) packing as head-to-head dimers
- Article discusses the crystal structure of a platinum(II) supramolecular building block, [Pt(dbbpy)(NCCH3)2](BF4)2 (dbbpy = 4,4′-di-tert-butyl-2,2′-bipyridine, C18H24N2).
- Molecular Markers of Neuropsychological Functioning and Alzheimer's Disease
- Article examines molecular markers of neuropsychological functioning among elders with and without Alzheimer's disease (AD) and determine the predictive ability of combined molecular markers and select neuropsychological tests in detecting disease presence. This work provides the foundation for the generation of a point‐of‐care device that can be used to screen for AD.
- Guidelines for the standardization of preanalytic variables for blood‐based biomarker studies in Alzheimer's disease research
- Review article which provides (1) a synopsis of selected preanalytical methods utilized in many international AD cohort studies, (2) initial draft guidelines/SOPs for preanalytical methods, and (3) a list of required methodological information and protocols to be made available for publications in the field to foster cross‐validation across cohorts and laboratories.
- Loitering at the hilltop on exterior domains
- In this article, the author proves the existence of an infinite number of radial solutions of Δu+f(u)=0 on the exterior of the ball of radius R>0 centered at the origin and f is odd with f<0 on (0,β), f>0 on (β,δ), and f≡0 for u>δ. The primitive F(u)=∫u0f(t)dt has a "hilltop" at u=δ which allows one to use the shooting method and ODE techniques to prove the existence of solutions.
- Overexpression of fatty acid amide hydrolase induces early flowering in Arabidopsis thaliana
- Article investigates the nature of the early flowering phenotype of AtFAAH overexpression.
- Florigen and anti-florigen – a systemic mechanism for coordinating growth and termination in flowering plants
- Article describes study establishing FLOWERING LOCUS T (FT) as a key flower-promoting gene in photoperiodic systems.
- The Differences between NAD-dependent malic enzyme and NADP-dependent malic enzyme Subtypes of C4 Photosynthesis: More than Decarboxylating Enzymes
- Article addresses the differences in evolutionary scenario, leaf anatomy, and especially C4 metabolic flow, C4 transporters, and cell-specific function deduced from recently reported cell-specific transcriptomic, proteomic, and metabolic analyses of NAD-dependent malic enzyme (NAD-ME) and NADP-dependent malic enzyme (NADP-ME) subtypes.
- Metabolomics as a hypothesis-generating functional genomics tool for the annotation of Arabidopsis thaliana genes of “unknown function”
- Article describes the analysis of Arabidopsis metabolomics data sets acquired by a consortium that includes five analytical laboratories, bioinformaticists, and biostatisticians, which aims to develop and validate metabolomics as a hypothesis-generating functional genomics tool.
- Biochemical and molecular-genetic characterization of SFD1’s involvement in lipid metabolism and defense signaling
- Article describes study which sought to to determine if the dihydroxyacetone phosphate (DHAP) reductase activity and chloroplast localization are required for the Arabidopsis thaliana SFD1 (suppressor of fatty acid desaturase deficiency1) gene’s involvement in galactolipid metabolism and systemic acquired resistance (SAR) signaling.
- Cardiac and metabolic physiology of early larval zebrafish (Danio rerio) reflects parental swimming stamina
- Article describes experiment in which mature adult zebrafish (Danio rerio) were subjected to a swimming performance test that allowed separation into low swimming stamina or high swimming stamina groups in order to determine if inherited traits that support enhanced swimming stamina in offspring appear only in juveniles and/or adults, or if these traits actually appear earlier in the morphologically quite different larvae.
- Social Reward Questionnaire (SRQ): development and validation
- Article discusses study which led to the development of the Social Reward Questionnaire (SRQ), a measure of individual differences in the value of different social rewards.
- Elevated CO2 increases energetic cost and ion movement in the marine fish intestine
- Article describes study which aimed to gain resolution in assessing the energetic demand associated with acid-base regulation by examining ion movement and O2 consumption rates of isolated intestinal tissue from Gulf toadfish acclimated to control or 1900 μatm CO2 (projected for year 2300).
- SPHK1 regulates proliferation and survival responses in triple-negative breast cancer
- Article describes study suggesting that the inhibation of sphingosine kinase 1 (SPHK1) can attenuate ERK1/2 and AKT signaling and reduce growth of triple-negative breast cancer (TNBC) cells in vitro and in a xenograft SCID mouse model.
- Generalized second-order parametric optimality conditions in semiinfinitediscrete minmax fractional programming and second order (F,β,φ,ρ,θ,m)-univexity
- Article discusses establishing numerous sets of generalized second order paramertic sufficient optimality conditions for a semiinfinite discrete minmax fractional programming problem, while the results on semiinfinite discrete minmax fractional programming problem achieved based on some partitioning schemes under various types of generalized second order univexity assumptions.
- Effect of selection for commercially productive traits on the plasticity of cardiovascular regulation in chicken breeds during embryonic development
- Article investigates basic cardiovascular physiology in the Red Junglefowl, the broiler, and the White Leghorn breeds at 90% of incubation. The authors aimed to identify breed-specific features of arterial blood pressure and heart rate as well as the physiological mechanisms regulating them. They concluded that selection for rapid growth shifts cardiovascular regulatory plasticity to emphasize mechanisms that modulate pressure, and that selection for egg-laying capacity emphasizes mechanisms that modulate heart rate.
- Thymoquinone overcomes chemoresistance and enhances the anticancer effects of bortezomib through abrogation of NF-κB regulated gene products in multiple myeloma xenograft mouse model
- Article investigates whether thymoquinone (TQ), a bioactive constituent of black seed oil, could suppress the proliferation and induce chemosensitization in human myeloma cells and xenograft mouse model. Overall, the results demonstrate that TQ can enhance the anticancer activity of bortezomib in vitro and in vivo and may have a substantial potential in the treatment of MM.
- γ-tocotrienol inhibits angiogenesis-dependent growth of human hepatocellular carcinoma through abrogation of AKT/mammalian target of rapamycin pathway in an orthotopic mouse model
- Article describing an investigation into whether γ-tocotrienol can abrogate angiogenesis-mediated tumor growth in hepatocellular carcinoma (HCC) and if so, through what molecular mechanisms.
- Association of Host and Microbial Species Diversity across Spatial Scales in Desert Rodent Communities
- Article describes study in which researchers employed a natural gradient of rodent species richness and quantified bacterial communities in rodent blood at several hierarchical spatial scales to test the hypothesis that associations between host and microbial species diversity will be positive in communities dominated by organisms with broad niches sampled at large scales.
- Negative Regulation of Signal Transducer and Activator of Transcription-3 Signalling Cascade by Lupeol Inhibits Growth and Induces Apoptosis in Hepatocellular Carcinoma Cells
- In this article, the authors evaluate the effect of lupeol on STAT3 signalling cascade and its regulated functional responses in hepatocellular carcinoma (HCC) cells. Constitutive activation of signal transducer and activator of transcription signalling 3 (STAT3) has been linked with survival, proliferation and angiogenesis in a wide variety of malignancies including HCC. Lupeol exhibited its potential anticancer effects in HCC through the downregulation of STAT3-induced pro-survival signalling cascade.
- Introducción a la Sección Especial de Revista Bosque. Avances de una red de sitios de estudios ecológicos a largo plazo en el suroeste de Sudamérica
- This article is the forward to a special section on long-term ecological research in Chile. It briefly introduces the main topics and ideas of each of the articles and comment on their relevance in the context of research and monitoring of Chilean ecosystems and in the perspective of global change research.
- Pulsed cooperative backward emissions from non-degenerate atomic transitions in sodium
- Article describes study which examines backward cooperative emissions from a dense sodium atomic vapor.
- Spatially Periodic Electromagnetic Force Field For Plasma Confinement and Control
- In this article, a theoretical understanding is developed of the single-particle reflection properties of a force field, considering the incident charged particles to have a non-drifting, isotropic velocity distribution. Classical trajectory Monte Carlo simulations and analytical modeling are employed. The initiation of an experimental effort to study force fields is described.
- Molecular evolutionary and structural analysis of the cytosolic DNA sensor cGAS and STING
- Article describes study in which researchers carried out comprehensive evolutionary analyses of the GMP-AMP (cGAMP) synthase (cGAS)-STING pathway.
- Structural Consideration in Designing Organotin Polyethers to Arrest the Growth of Breast Cancer Cells In Vitro
- The article looks at antitumor activity using a matched pair of cell lines MDA-MB-231 cells that are estrogen-independent, estrogen receptor negative and MCF-7 cells, a cell line that is estrogen receptor (ER) positive. Those polyethers that contained a O-phenyl unit were able to significantly inhibit the non-estrogen sensitive cell line but were much less effective against the estrogen sensitive cell line; that is, the human breast cancer cell line MDA-MB-231 showed better test results for polymers derived from diols containing the O-phenyl moiety than the breast cancer cell line MCF-7, a well-characterized estrogen receptor positive control cell line.
- Antiviral Activity of Metal-Containing Polymers—Organotin and Cisplatin-Like Polymers
- This article examines the use of metal-containing polymers as a novel class of antivirals. Polymers containing platinum and to a lesser extent tin, have repeatedly demonstrated antitumor activity in vitro and in vivo against a variety of cell and tumor types. The mechanisms responsible for the antitumor activity include inducing a delay in cell proliferation and sister chromatid exchanges blocking tumor growth.