Publications by authors named "Abbott N"

The Gulf States are home to industries emitting styrene, benzene, toluene, ethylbenzene, and xylenes (SBTEX). Presently, adverse health effects of ambient SBTEX exposure in highly polluted regions, such as the Gulf States, must be evaluated. Epidemiologists, however, are limited by inadequate estimates of ambient SBTEX.

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Recent studies have reported that the overexpression of MUC1 glycoproteins on cell surfaces changes the morphology of cell plasma membranes and increases the blebbing of vesicles from them, supporting the hypothesis that entropic forces exerted by MUC1 change the spontaneous curvature of cell membranes. However, how MUC1 is incorporated into and influences the size and biophysical properties of plasma-membrane-blebbed vesicles is not understood. Here we report single-vesicle-level characterization of giant plasma membrane vesicles (GPMVs) derived from cells overexpressing MUC1, revealing a 40× variation in MUC1 density between GPMVs from a single preparation and a strong correlation between GPMV size and MUC1 density.

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Liquid crystals (LCs), when interfaced with chemically functionalized surfaces, can amplify a range of chemical and physical transformations into optical outputs. While metal cation-binding sites on surfaces have been shown to provide a basis for the design of chemoresponsive LCs, the cations have been found to dissociate from the surfaces and dissolve slowly into LCs, resulting in time-dependent changes in the properties of LC-solid interfaces (which impacts the reliability of devices incorporating such surfaces). Here, we explore the use of surfaces comprising metal-coordinating polymers to minimize the dissolution of metal cations into LCs and characterize the impact of the interfacial environment created by the coordinating polymer on the ordering and time-dependent properties of LCs.

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We elucidate a previously unknown synthesis pathway that leads to polymeric nanospheres, orientation-controlled microgels, or microspheroids via single-step polymerization of divinylbenzene (DVB) using initiated chemical vapor deposition (iCVD) in liquid crystals (LC). iCVD supplies vapor-phase reactants continuously, avoiding the critical limitation of reactant-induced disruption of LC structure that has plagued past LC-templated polymerization processes. LC is leveraged as a real-time display of the polymerization conditions and particle emergence, captured using an in situ long-focal range microscope.

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An isotope-dilution bioanalytical assay for abemaciclib and its metabolites in combination with olaparib was developed and validated in human plasma K2 EDTA. For the quantitative assay, human plasma samples (or human plasma QC samples) were spiked with internal standard solution before a simple protein precipitation with methanol. The extract was injected onto a liquid chromatography-tandem mass spectrometry (LC-MS/MS) instrument where it was chromatographically separated by a polar end-capped reversed phase column and guard using gradient elution with water and methanol both modified with 0.

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The EFOMP working group on the Role of Medical Physics Experts (MPEs) in Clinical Trials was established in 2010, with experts from across Europe and different areas of medical physics. Their main aims were: (1) To develop a consensus guidance document for the work MPEs do in clinical trials across Europe. (2) Complement the work by American colleagues in AAPM TG 113 and guidance from National Member Organisations.

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This study examined whether children with Developmental Language Disorder (DLD) have knowledge of binding principles (i.e., linking pronouns to their structurally licensed antecedent) during real-time sentence processing (cross-modal priming, real-time) and overt comprehension (sentence-picture matching, interpretative) and whether rate of speech impacted access to that knowledge.

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Shape morphing is vital to locomotion in microscopic organisms but has been challenging to achieve in sub-millimetre robots. By overcoming obstacles associated with miniaturization, we demonstrate microscopic electronically configurable morphing metasheet robots. These metabots expand locally using a kirigami structure spanning five decades in length, from 10 nm electrochemically actuated hinges to 100 μm splaying panels making up the ~1 mm robot.

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Multidimensional solitons are prevalent in numerous research fields. In orientationally ordered soft matter system, three-dimensional director solitons exemplify the localized distortion of molecular orientation. However, their precise manipulation remains challenging due to unpredictable and uncontrolled generation.

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Solitons in nematic liquid crystals facilitate the rapid transport and sensing in microfluidic systems. Little is known about the elementary conditions needed to create solitons in nematic materials. In this study, we apply a combination of theory, computational simulations, and experiments to examine the formation and propagation of solitary waves, or "solitons", in nematic liquid crystals under the influence of an alternating current (AC) electric field.

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A key challenge underlying the design of miniature machines is encoding materials with time- and space-specific functional behaviors that require little human intervention. Dissipative processes that drive materials beyond equilibrium and evolve continuously with time and location represent one promising strategy to achieve such complex functions. This work reports how internal nonequilibrium states of liquid crystal (LC) emulsion droplets undergoing chemotaxis can be used to time the delivery of a chemical agent to a targeted location.

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Microtubules and catalytic motor proteins underlie the microscale actuation of living materials, and they have been used in reconstituted systems to harness chemical energy to drive new states of organization of soft matter (e.g., liquid crystals (LCs)).

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Developmental language disorder (DLD) is a heterogenous neurodevelopmental disorder that affects a child's ability to comprehend and/or produce spoken and/or written language, yet it cannot be attributed to hearing loss or overt neurological damage. It is widely believed that some combination of genetic, biological, and environmental factors influences brain and language development in this population, but it has been difficult to bridge theoretical accounts of DLD with neuroimaging findings, due to heterogeneity in language impairment profiles across individuals and inconsistent neuroimaging findings. Therefore, the purpose of this overview is two-fold: (1) to summarize the neuroimaging literature (while drawing on findings from other language-impaired populations, where appropriate); and (2) to briefly review the theoretical accounts of language impairment patterns in DLD, with the goal of bridging the disparate findings.

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Solitons in liquid crystals have generated considerable interest. Several hypotheses of varying complexity have been advanced to explain how they arise, but consensus has not emerged yet about the underlying forces responsible for their formation or their structure. In this work, we present a minimal model for solitons in achiral nematic liquid crystals, which reveals the key requirements needed to generate them in the absence of added charges.

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Computational chemistry calculations are broadly useful for guiding the atom-scale design of hard-soft material interfaces including how molecular interactions of single-component liquid crystals (LCs) at inorganic surfaces lead to preferred orientations of the LC far from the surface. The majority of LCs, however, are not single-component phases but comprise of mixtures, such as a mixture of mesogens, added to provide additional functions such as responsiveness to the presence of targeted organic compounds (for chemical sensing). In such LC mixtures, little is understood about the near-surface composition and organization of molecules and how that organization propagates into the far-field LC orientation.

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Glucocorticoid receptor (GR) is a transcription factor that plays a crucial role in cancer biology. In this study, we utilized an in silico-designed GR activity signature to demonstrate that GR relates to the proliferative capacity of numerous primary cancer types. In breast cancer, the GR activity status determines luminal subtype identity and has implications for patient outcomes.

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Solitons are highly confined, propagating waves that arise from nonlinear feedback in natural (e.g., shallow and confined waters) and engineered systems (e.

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Self-assembly of functional liquid crystals provides a powerful approach to the development of stimuli-responsive materials and interfaces. Here, we have designed and synthesized bioconjugated amphiphilic dendritic mesogens containing arginine-glycine-aspartic acid (RGD) peptide sequence to develop new biofunctional aqueous/liquid crystalline interfaces. We have found that the RGD peptide-conjugated forklike mesogens induce the homeotropic alignment of liquid crystals at the aqueous interfaces, leading to distinct optical changes caused by the specific binding of the target proteins.

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Article Synopsis
  • Concentrative nucleoside transporters (CNTs), specifically CNT1, play a crucial role in the renal reabsorption of nucleosides, but their in vivo functions were not well understood before this study.
  • Researchers created CNT1 knockout (KO) mice and found that these mice had increased levels of urinary excretion of certain nucleosides and a disrupted metabolism of purine nucleosides.
  • The study also revealed that CNT1 KO mice showed poor tumor control when treated with the nucleoside analog gemcitabine, but increasing the dosage to levels seen in normal mice improved its anticancer effects, highlighting the importance of CNT1 in the efficacy of nucleoside-based therapies.
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We measure and model monolayers of concentrated diffusing colloidal probes interacting with polymerized liquid crystal (PLC) planar surfaces. At topological defects in local nematic director profiles at PLC surfaces, we observe time-averaged two-dimensional particle density profiles of diffusing colloidal probes that closely correlate with spatial variations in PLC optical properties. An inverse Monte Carlo analysis of particle concentration profiles yields two-dimensional PLC interfacial energy landscapes on the -scale, which is the inherent scale of many interfacial phenomena (, self-assembly, adsorption, diffusion).

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Biological systems convert chemical energy into mechanical work by using protein catalysts that assume kinetically controlled conformational states. Synthetic chemomechanical systems using chemical catalysis have been reported, but they are slow, require high temperatures to operate, or indirectly perform work by harnessing reaction products in liquids (e.g.

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How steroid hormone receptors (SHRs) regulate transcriptional activity remains partly understood. Upon activation, SHRs bind the genome together with a co-regulator repertoire, crucial to induce gene expression. However, it remains unknown which components of the SHR-recruited co-regulator complex are essential to drive transcription following hormonal stimuli.

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Identifying and removing microplastics (MPs) from the environment is a global challenge. This study explores how the colloidal fraction of MPs assemble into distinct 2D patterns at aqueous interfaces of liquid crystal (LC) films with the goal of developing surface-sensitive methods for identifying MPs. Polyethylene (PE) and polystyrene (PS) microparticles are measured to exhibit distinct aggregation patterns, with addition of anionic surfactant amplifying differences in PS/PE aggregation patterns: PS changes from a linear chain-like morphology to a singly dispersed state with increasing surfactant concentration whereas PE forms dense clusters at all surfactant concentrations.

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Hypothesis: Gradients in the concentration of amphiphiles play an important role in many non-equilibrium processes involving complex fluids. Here we explore if non-equilibrium interfacial behaviors of thermotropic (oily) liquid crystals (LCs) can amplify microscopic gradients in surfactant concentration into macroscopic optical signals.

Experiments: We use a milli-fluidic system to generate gradients in aqueous sodium dodecyl sulfate (SDS) concentration and optically quantify the dynamic ordering of micrometer-thick nematic LC films that contact the gradients.

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