cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Conformational Analysis of Membrane Proteins in Phospholipid Bilayer Nanodiscs by Hydrogen Exchange Mass Spectrometry
Creators: name: Jorgenson, James W.
name: Rand, Kasper D.
name: Hebling, Christine M.
name: Morgan, Christopher R.
name: Stafford, Darrel W.
name: Engen, John R.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: The study of membrane protein structure and enzymology has traditionally been hampered by the inherent insolubility of membrane proteins in aqueous environments and experimental challenges in emulating an in vivo lipid environment. Phospholipid bilayer nanodiscs have recently been shown to be of great use for the study of membrane proteins since they offer a controllable, stable, and monodisperse model membrane with a native-like lipid bilayer. Here we report the integration of nanodiscs with hydrogen exchange (HX) mass spectrometry (MS) experiments, thereby allowing for analysis of the native conformation of membrane proteins. Gamma-glutamyl carboxylase (GGCX), an ~94 kDa transmembrane protein, was inserted into nanodiscs and labeled with deuterium oxide under native conditions. Analytical parameters including sample-handling and chromatographic separation were optimized to measure the incorporation of deuterium into GGCX. Coupling nanodisc technology with HX MS offers an effective approach for investigating the conformation and dynamics of membrane proteins in their native environment and is therefore capable of providing much needed insight into the function of membrane proteins.
On the longitudinal structure function in the dipole model
Creators: name: Niedziela, Marek
name: Praszalowicz, Michal
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We compare new HERA data for the longitudinal structure function $F_{\rm L}$ with the predictions of different variants of the dipole model. In particular we show that the ratio $F_{\rm L}/F_2$ is well described by the dipole models and is rather insensitive to the details of the fit. Fits to $F_2$ are performed with the help of geometrical scaling (GS). Using the property of GS we derive the bounds for $F_{\rm L}/F_2$ both for the different versions of the dipole model and in the general case. Finally we briefly discuss how the higher Fock components of the photon wave function may affect these bounds.
description: 19 pages, 11 figures, v3 to be published in Acta Physica Polonica B
Development of a Photothermal Absorbance Detector for Use with Microfluidic Devices
Creators: name: Welch, Erin Ferguson
name: Alarie, Jean Pierre
name: Ramsey, J. Michael
name: Jorgenson, James W.
name: Dennis, Patty J.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: The development of a photothermal absorbance detector for use with microfluidic devices is described. Unlike thermooptical techniques that rely on measuring refractive index changes, the solution viscosity is probed by continuously monitoring solution conductivity. Platinum electrodes microfabricated on a quartz substrate and bonded to a substrate containing the microchannels enable contact conductivity measurements. The effects of excitation frequency and voltage, electrode spacing, laser power, and laser modulation (chopping) frequency were evaluated experimentally. In the current configuration a limit of detection of 5 nM for DABSYL-tagged glucosamine was obtained using long injections (to give flat-topped peaks). This corresponds to an absorbance of 4.4 × 10−7 AU. Separation and detection of DABSYL-tagged glycine, proline, and tryptophan is also shown to demonstrate the feasibility of the method. In addition, simulations were used to investigate the applicability of the technique to small volume platforms.
Thomas-Fermi theory of out-of-plane charge screening in graphene
Creators: name: Moroz, Vitaly
name: Muratov, Cyrill B.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: This paper provides a variational treatment of the effect of external charges on the free charges in an infinite free-standing graphene sheet within the Thomas-Fermi theory. We establish existence, uniqueness and regularity of the energy minimizers corresponding to the free charge densities that screen the effect of an external electrostatic potential at the neutrality point. For the potential due to one or several off-layer point charges, we also prove positivity and a precise universal asymptotic decay rate for the screening charge density, as well as an exact charge cancellation by the graphene sheet. We also treat a simpler case of the non-zero background charge density and establish similar results in that case.
description: 30 pages, 2 figures
Genome Detective Platform adaptations for plant viruses
Creators: name: Cleemput, S.
name: Dierickx, S.
Publisher: name: Zenodo
Year: 2025

description: Deliverable 2.4 outlines the changes made to the Genome Detective Platform to accommodate the collection and analysis of plant virus samples, including metagenomic viral sequences and epidemiological metadata annotations, for the analysis of plant virus outbreaks.The H2020 project VIRTIGATION - Emerging viral diseases in tomatoes and cucurbits: Implementation of mitigation strategies for durable disease management - has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 101000570.
Experimental and computational investigation of the influence of stoichiometric mixture fraction on structure and extinction of laminar, nonpremixed dimethyl ether flames
Creators: name: Mairinger, Gerald
name: Rohit Sanjay Khare
name: Krithika Narayanaswamy
name: Hunyadi-Gall, Martin
name: Vasudevan Raghavan
name: Kalyanasundaram Seshadri
Publisher: name: Figshare
Year: 2019
Subjects: subject: Biophysics
subject: Biochemistry
subject: Cell Biology
subject: Neuroscience
subject: Physiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Science Policy
subject: 111714 Mental Health
subject: FOS: Health sciences
subject: Hematology
subject: 110309 Infectious Diseases
subject: 60506 Virology

description: Experimental and computational investigation is carried out to elucidate the influence of stoichiometric mixture fraction, ξst, on the structure and critical conditions of extinction of nonpremixed dimethyl ether (DME) flames. The stoichiometric mixture fraction represents the location of a thin reaction zone in terms of a conserved scalar quantity. The counterflow configuration is employed, wherein two reactant streams flow towards a stagnation plane. One stream is made up of DME and nitrogen (N2) and the other stream is oxygen and N2. Previous studies have shown that critical conditions of extinction depend on ξst and the adiabatic temperature Tst. Therefore, the present investigation is carried out with the composition of the reactants in the counterflowing streams so chosen that the adiabatic temperature is the same for different values of ξst. The strain rate at extinction, aq, is measured for values of ξst up to 0.8. Computations are performed using detailed kinetic mechanisms and critical conditions of extinction and flame structures are predicted. The measurements and predictions show that, with increasing ξst, the strain rate at extinction first decreases and then increases. The predictions agree with measurements for ξst<0.4, but significant deviations between measurements and predictions are observed at higher values of ξst. The scalar dissipation rate at extinction, χst,q is calculated using measured and predicted values of aq. With increasing ξst, the measured and predicted values of χst,q first increase and then decrease. It is noteworthy that changes in values of χst,q with ξst for dimethyl ether flames are similar to those for methane flames, while the changes in values of aq with ξst are remarkably different. Flame structures are predicted and they are found to be qualitatively similar to those for hydrocarbon fuels.
High Yield Sample Preconcentration Using a Highly Ion-Conductive Charge-Selective Polymer
Creators: name: Ramsey, J. Michael
name: Chun, Honggu
name: Chung, Taek Dong
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: The development and analysis of a microfluidic sample preconcentration system using a highly ion-conductive charge-selective polymer (poly-AMPS) is reported. The preconcentration is based on the phenomenon of concentration polarization which develops at the boundaries of the poly-AMPS with buffer solutions. A negatively charged polymer, poly-AMPS, positioned between two microchannels efficiently extracts cations through its large cross section, resulting in efficient anion sample preconcentration. The present work includes the development of a robust polymer that is stable over a wide range of buffers with varying chemical compositions. The sample preconcentration effect remains linear to over 3 mM (0.15 pmol) and 500 μM (15 fmol) for fluorescein and TRITC-tagged albumin solutions, respectively. The system can potentially be used for concentrating proteins on microfluidic devices with subsequent analysis for proteomic applications.
Softened Gravity and the Extension of the Standard Model up to Infinite Energy
Creators: name: Giudice, Gian F.
name: Isidori, Gino
name: Salvio, Alberto
name: Strumia, Alessandro
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Attempts to solve naturalness by having the weak scale as the only breaking of classical scale invariance have to deal with two severe difficulties: gravity and the absence of Landau poles. We show that solutions to the first problem require premature modifications of gravity at scales no larger than $10^{11}$ GeV, while the second problem calls for many new particles at the weak scale. To build models that fulfil these properties, we classify 4-dimensional Quantum Field Theories that satisfy Total Asymptotic Freedom (TAF): the theory holds up to infinite energy, where all coupling constants flow to zero. We develop a technique to identify such theories and determine their low-energy predictions. Since the Standard Model turns out to be asymptotically free only under the unphysical conditions $g_1 = 0$, $M_t = 186$ GeV, $M_τ= 0$, $M_h = 163$ GeV, we explore some of its weak-scale extensions that satisfy the requirements for TAF.
description: 60 pages. Final version to appear on JHEP. v3: references added
Duration of Untreated Psychosis in the United States: A Scoping Review Focused on Equity
Creators: name: Swaim, Katarina
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2023

description: Background: Although many studies have assessed the relationship between duration of untreated psychosis (DUP) and schizophrenia outcomes, the relationship between sociodemographic variables and DUP remains unclear.
Methods: I conducted a scoping review of research based in the United States that reported any measure of DUP in addition to at least one sociodemographic variable with the aim of describing deficiencies in the documentation of the role of structural racism in the context of DUP. A systematic search of PubMed, PsycInfo, and Cochrane Library from 1975 to April 2023 was performed. 
Results: Of 465 studies identified, 20 met inclusion criteria. Operationalization of DUP varied between studies in terms of both criteria for psychosis onset and DUP end point. Of 17 studies reporting racial/ethnic data, only 5 gathered the information using participant self-report. Sixteen studies included a measure of socioeconomic status. Ten studies analyzed for an association between any sociodemographic variable and DUP. Five studies subdivided DUP into “help-seeking” and “referral delay” components in order to ascertain effects of both individual behaviors and the systems-level service delivery on pathways to care.
Conclusions: Current practices in early psychosis research are missing significant opportunities to examine and understand known disparities in mental health care access in the US. Recommendations for future research include: a focus on recruitment of ethnically and socioeconomically diverse study participants; collection of race/ethnicity data by participant self-report; clearly defining operationalization of DUP; and adoption of “help-seeking” and “referral delay” DUP classifications.
Damage-Fitness Model: the missing piece in integrative stress models
Creators: name: Wada, Haruka
Publisher: name: Taylor & Francis
Year: 2019
Subjects: subject: Biophysics
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Physiology
subject: Biotechnology
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: Science Policy
subject: 111714 Mental Health
subject: FOS: Health sciences

description: Over the last decade, several theoretical models have been put forth to describe how animals respond to adverse environments and how this response changes under different physiological demands across life history stages. These models capture the context- and condition-dependent nature of stress responses. Yet, application of the models has been limited thus far in part because each model addresses different aspects of the problems facing the field of stress biology. Thus, there is a need for a unifying theoretical model that incorporates changes in physiological demand with life history stages and age, intricate relationships among physiological systems, and biphasic nature of stress responses. Here, I propose a new integrative framework, the Damage-Fitness Model. In this model, regulators, such as DNA repair mechanisms and glucocorticoids, work together as anti-damage mechanisms to minimize damage at both the cellular and organismal level. When the anti-damage regulators are insufficient or inappropriate, persistent damage accumulates. Previous studies indicate that these damage directly impact reproductive performance, disease risk, and survival. The types of regulators, the threshold at which they are initiated, and the magnitude of the responses are shaped by developmental and current environments. This model unites existing theoretical models by shifting our focus from physiological responses to downstream consequences of the stress responses, circumventing context specificity. Discussions include (1) how the proposed model relates to existing models, (2) steps to test the new model, and (3) how this model can be used to better assess the health of individuals and a population. Lay summary The field of stress physiology faces a challenge of characterizing dynamic cellular, physiological, and behavioral responses when animals encounter a stressor. This paper proposes a new theoretical model which links stress avoidance, damage repair and accumulation, and fitness components.
Reduced energies for thin ferromagnetic films with perpendicular anisotropy
Creators: name: Di Fratta, G.
name: Muratov, C. B.
name: Slastikov, V. V.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We derive four reduced two-dimensional models that describe, at different spatial scales, the micromagnetics of ultrathin ferromagnetic materials of finite spatial extent featuring perpendicular magnetic anisotropy and interfacial Dzyaloshinskii-Moriya interaction. Starting with a microscopic model that regularizes the stray field near the material's lateral edges, we carry out an asymptotic analysis of the energy by means of $Γ$-convergence. Depending on the scaling assumptions on the size of the material domain vs. the strength of dipolar interaction, we obtain a hierarchy of the limit energies that exhibit progressively stronger stray field effects of the material edges. These limit energies feature, respectively, a renormalization of the out-of-plane anisotropy, an additional local boundary penalty term forcing out-of-plane alignment of the magnetization at the edge, a pinned magnetization at the edge, and, finally, a pinned magnetization and an additional field-like term that blows up at the edge, as the sample's lateral size is increased. The pinning of the magnetization at the edge restores the topological protection and enables the existence of magnetic skyrmions in bounded samples.
description: 30 pages, 1 figure
Integrated Microfluidic Device for Automated Single Cell Analysis Using Electrophoretic Separation and Electrospray Ionization Mass Spectrometry
Creators: name: Jorabchi, Kaveh
name: Ramsey, J. Michael
name: Mellors, J. Scott
name: Smith, Lloyd M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: A microfabricated fluidic device was developed for the automated real-time analysis of individual cells using capillary electrophoresis (CE) and electrospray ionization-mass spectrometry (ESI-MS). The microfluidic structure incorporates a means for rapid lysis of single cells within a free solution electrophoresis channel where cellular constituents were separated and an integrated electrospray emitter for ionization of separated components. The eluent was characterized using mass spectrometry. Human erythrocytes were used as a model system for this study. In this monolithically integrated device, cell lysis occurs at a channel intersection using a combination of rapid buffer exchange and an increase in electric field strength. An electroosmotic pump is incorporated at the end of the electrophoretic separation channel to direct eluent to the integrated electrospray emitter. The dissociated heme group and the α and β subunits of hemoglobin from individual erythrocytes were detected as cells continuously flowed through the device. The average analysis throughput was approximately 12 cells per minute demonstrating the potential of this method for high-throughput single cell analysis.
Higher Sensitivity Dopamine Measurements with Faster-Scan Cyclic Voltammetry
Creators: name: Keithley, Richard B.
name: Wightman, R. Mark
name: Takmakov, Pavel
name: Belle, Anna M.
name: Park, Jinwoo
name: Bucher, Elizabeth S.
name: Owesson-White, Catarina A.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Fast-scan cyclic voltammetry with carbon-fiber microelectrodes has been successfully used to detect catecholamine release in vivo. Generally, waveforms with anodic voltage limits of 1.0 V or 1.3 V (vs. Ag/AgCl) are used for detection. The 1.0 V excursion provides good temporal resolution, but suffers from a lack of sensitivity. The 1.3 V excursion increases sensitivity, but also increases response time which can blur the detection of neurochemical events. Here, the scan rate was increased to improve the sensitivity of the 1.0 V excursion while maintaining the rapid temporal response. However, increasing scan rate increases both the desired faradaic current response and the already large charging current associated with the voltage sweep. Analog background subtraction was used to prevent the analog-to-digital converter from saturating from the high currents generated with increasing scan rate by neutralizing some of the charging current. In vitro results with the 1.0 V waveform showed approximately a four-fold increase in signal to noise ratio with maintenance of the desired faster response time by increasing scan rate up to 2400 V/s. In vivo, stable stimulated release was detected with an approximate four-fold increase in peak current. The scan rate of the 1.3 V waveform was also increased, but the signal was unstable with time in vitro and in vivo. Adapting the 1.3 V triangular wave into a sawhorse design prevented signal decay and increased the faradaic response. The use of the 1.3 V sawhorse waveform decreased the detection limit of dopamine with FSCV to 0.96 ± 0.08 nM in vitro and showed improved performance in vivo without affecting the neuronal environment. Electron microscopy showed dopamine sensitivity is in a quasi-steady state with carbon-fiber microelectrodes scanned to potentials above 1.0 V.
Increased In Vivo Glucose Recovery via Nitric Oxide Release
Creators: name: Klitzman, Bruce
name: Nichols, Scott P.
name: Schoenfisch, Mark H.
name: Le, Nga N.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: The in vivo glucose recovery of subcutaneously implanted nitric oxide (NO)-releasing microdialysis probes was evaluated in a rat model using saturated NO solutions to steadily release NO. Such methodology resulted in a constant NO flux of 162 pmol cm-2 s-1 from the probe membrane over 8 h of perfusion daily. The in vivo effects of enhanced localized NO were evaluated by monitoring glucose recovery over a 14 d period, with histological analysis thereafter. A difference in glucose recovery was observed starting at 7 d for probes releasing NO relative to controls. Histological analysis at 14 d revealed lessened inflammatory cell density at the probe surface and decreased capsule thickness. Collectively, the results suggest that intermittent sustained NO release from implant surfaces may improve glucose diffusion for subcutaneously-implanted sensors by mitigating the foreign body reaction.
Real-World Incidence and Severity of Hypertension Caused by Abiraterone Acetate in Patients with Metastatic Prostate Cancer
Creators: name: Brian Lam
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2023

description: Abiraterone acetate (AA) is used in treatment of patients with metastatic prostate cancer. Despite the survival advantage, AA is associated with hypertension due to mineralocorticoid excess syndrome. We conducted a single center retrospective analysis to evaluate the real-world incidence and severity of AA-induced hypertension.
Monolithic Integration of Two-Dimensional Liquid Chromatography−Capillary Electrophoresis and Electrospray Ionization on a Microfluidic Device
Creators: name: Mellors, J. Scott
name: Chambers, Andrew G.
name: Henley, W. Hampton
name: Ramsey, J. Michael
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: A microfluidic device capable of two-dimensional reversed-phase liquid chromatography-capillary electrophoresis with integrated electrospray ionization (LC-CE-ESI) for mass spectrometry (MS)-based proteomic applications is described. Traditional instrumentation was used for the LC sample injection and delivery of the LC mobile phase. The glass microfabricated device incorporated a sample-trapping region and an LC channel packed with reversed-phase particles. Rapid electrokinetic injections of the LC effluent into the CE dimension were performed at a cross channel intersection. The CE separation channel terminated at a corner of the square device, which functioned as an integrated electrospray tip. In addition to LC-CE-ESI, this device was used for LC-ESI without any instrumental modifications. To evaluate the system, LC-MS and LC-CE-MS analysis of protein digests were performed and compared.
"Damage-Fitness Model: the missing piece in integrative stress models
Creators: name: Wada, Haruka
Publisher: name: Taylor & Francis
Year: 2019
Subjects: subject: Biophysics
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Physiology
subject: Biotechnology
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: Science Policy
subject: 111714 Mental Health
subject: FOS: Health sciences

description: Over the last decade, several theoretical models have been put forth to describe how animals respond to adverse environments and how this response changes under different physiological demands across life history stages. These models capture the context- and condition-dependent nature of stress responses. Yet, application of the models has been limited thus far in part because each model addresses different aspects of the problems facing the field of stress biology. Thus, there is a need for a unifying theoretical model that incorporates changes in physiological demand with life history stages and age, intricate relationships among physiological systems, and biphasic nature of stress responses. Here, I propose a new integrative framework, the Damage-Fitness Model. In this model, regulators, such as DNA repair mechanisms and glucocorticoids, work together as anti-damage mechanisms to minimize damage at both the cellular and organismal level. When the anti-damage regulators are insufficient or inappropriate, persistent damage accumulates. Previous studies indicate that these damage directly impact reproductive performance, disease risk, and survival. The types of regulators, the threshold at which they are initiated, and the magnitude of the responses are shaped by developmental and current environments. This model unites existing theoretical models by shifting our focus from physiological responses to downstream consequences of the stress responses, circumventing context specificity. Discussions include (1) how the proposed model relates to existing models, (2) steps to test the new model, and (3) how this model can be used to better assess the health of individuals and a population. Lay summary The field of stress physiology faces a challenge of characterizing dynamic cellular, physiological, and behavioral responses when animals encounter a stressor. This paper proposes a new theoretical model which links stress avoidance, damage repair and accumulation, and fitness components.
Selection and Separation of Viable Cells Based on a Cell-Lethal Assay
Creators: name: Sims, Christopher E.
name: Phillips, Colleen
name: Xu, Wei
name: Pai, Jeng-Hao
name: Allbritton, Nancy L.
name: Herman, Annadele
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: A method to select and separate viable cells based on the results of a cell-lethal assay was developed. Cells were plated on an array of culture sites with each site composed of closely spaced, releasable micropallets. Clonal colonies spanning multiple micropallets on individual culture sites were established within 72 h of plating. Adjacent sites were widely spaced with 100% of the colonies remaining sequestered on a single culture site during expansion. A laser-based method mechanically released a micropallet underlying a colony to segment the colony into two genetically identical colonies. One portion of the segmented colony was collected with 90% efficiency while viability of both fractions was 100%. The segmented colonies released from the array were fixed and subjected to immunofluorescence staining of intracellular phospho-ERK kinase to identify colonies that were highly resistant or sensitive to phorbol ester-induced activation of ERK. These resistant and sensitive cells were then matched to the corresponding viable colonies on the array. Sensitive and resistant colonies on the array were released and cultured. When these cultured cells were reanalyzed for phorbol ester-induced ERK activity, the cells retained the sensitive or resistant phenotype of the originally screened subcolony. Thus cells were separated and collected based using the result of a cell-lethal assay as selection criteria. These microarrays enabling clonal colony segmentation permitted sampling and manipulation of the colonies at very early times and at small cell numbers to reduce reagent, time and manpower requirements.
Temporal witnesses of non-classicality in a macroscopic biological system
Creators: name: Di Pietra, Giuseppe
name: Vedral, Vlatko
name: Marletto, Chiara
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Exciton transfer along a polymer is essential for many biological processes, for instance light harvesting in photosynthetic biosystems. Here we apply a new witness of non-classicality to this phenomenon, to conclude that, if an exciton can mediate the coherent quantum evolution of a photon, then the exciton is non-classical. We then propose a general qubit model for the quantum transfer of an exciton along a polymer chain, also discussing the effects of environmental decoherence. The generality of our results makes them ideal candidates to design new tests of quantum features in complex bio-molecules.
description: 16 pages (7 pages main text, 9 pages appendices), 8 figures
Adiabatic many-body state preparation and information transfer in quantum dot arrays
Creators: name: Farooq, Umer
name: Bayat, Abolfazl
name: Mancini, Stefano
name: Bose, Sougato
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum simulation of many-body systems are one of the most interesting tasks of quantum technology. Among them is the preparation of a many-body system in its ground state when the vanishing energy gap makes the cooling mechanisms ineffective. Adiabatic theorem, as an alternative to cooling, can be exploited for driving the many-body system to its ground state. In this paper, we study two most common disorders in quantum dot arrays, namely exchange coupling fluctuations and hyperfine interaction, in adiabatically preparation of ground state in such systems. We show that the adiabatic ground state preparation is highly robust against those disorder effects making it good analog simulator. Moreover, we also study the adiabatic classical information transfer, using singlet-triplet states, across a spin chain. In contrast to ground state preparation the transfer mechanism is highly affected by disorder and in particular, the hyperfine interaction is very destructive for the performance. This suggests that for communication tasks across such arrays adiabatic evolution is not as effective and quantum quenches could be preferable.
description: 6 pages, 5 figures
Abschluß eines Lebens - Abschluß eines Werkes
Creators: name: Roegele, Otto Bernhard
Publisher: name: Internationale katholische Zeitschrift Communio
Year: 2022

description: Internationale katholische Zeitschrift Communio, Bd. 14 Nr. 6 (1985): Internationale katholische Zeitschrift Communio, Band 14, Heft 6
Evaluation of the Impact of Human Hepatocyte-Derived Exosomes on Immune Response in Idiosyncratic Drug-Induced Liver Injury
Creators: name: Choe, Angel
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2023

description: Introduction: Idiosyncratic drug-induced liver injury (IDILI) is a rare, but serious adverse drug reaction that occurs rarely among treated patients and often only after several weeks or months of treatment with the offending drug. Previous work from our group suggests that hepatocyte-derived exosomes (HDEs) may play a role in activating the innate immune system, which is likely a critical step in the pathogenesis of idiosyncratic drug-induced liver injury. Several non-parenchymal liver cell types including liver sinusoidal endothelial cells (LSECs) participate in this innate immune response. In this study, we tested the hypothesis that HDEs released from IDILI drug-treated hepatocytes modulate the immune response of LSECs.
Methods: First, we determined the peak bosentan media concentrations that did not cause overt toxicity to modify cultures of the human hepatocyte cell line, HuH-7. The HuH-7 cells were treated with vehicle (DMSO) or bosentan at three different concentrations. Exosomes were then isolated from these cultures and applied to a human LSEC cell line, TMNK-1, for 24 hours. All treatments were done in the presence and absence of lipopolysaccharide (LPS). TMNK-1 cell media from each treatment group was then collected and analyzed for pro-inflammatory cytokine release (IL-1β, IL-6, and TNF-α).
Results: LPS stimulation induced a significant increase in pro-inflammatory cytokine release in TMNK-1 cells in the absence of HDE treatment (mock control) as expected. There was no significant difference in pro-inflammatory cytokine release from TMNK-1 cells exposed to control HDEs in comparison to mock control, with or without LPS stimulation. In addition, we did not observe a significant difference in cytokine release in TMNK-1 cells exposed to HDE’s from bosentan-treated HuH-7 cells in comparison to exposure to HDEs from untreated HuH-7 cells. Interestingly, we did observe a significant increase in ATP levels in TMNK-1 cells in response to HDEs in comparison to mock control, regardless of bosentan treatment or exposure to LPS.
Conclusions: We established a robust model to study immune stimulation of TMNK-1 cells by HDEs. Our data with bosentan do not support our hypothesis that HDEs released from untreated or IDILI drug-treated hepatocytes modulate the immune responsiveness of LSECs. However, our methods may be applied to study the effects of other IDILI inducing drugs. Our finding that HDEs caused increased ATP production in TMNK-1 cells is unexpected and should be further investigated.
Design of an Application for Collaboration and Interaction with Animated Content for Children in a Television Ecosystem
Creators: name: Marques, Jorge Teixeira
Publisher: name: Figshare
Year: 2019
Subjects: subject: 80602 Computer-Human Interaction
subject: FOS: Psychology

description: The ongoing research project presented in this paper
aims to propose and evaluate models of interaction
with audiovisual animated content in an interactive
television ecosystem. Through the referred models we
aim to understand the extent to which an interactive
animation application can encourage the shared
participation of children at primary school level in
taking an active role while watching TV animation. Here
we present the conceptual and empirical methodology
adopted to develop the research work and the current
state of research.
LIV constraints derived from INTEGRAL observations of polarized GRB
Creators: name: Laurent, Philippe
Publisher: name: Zenodo
Year: 2022

description: In complement to spectro-imaging and timing observations, polarimetry provides a unique in-sight into the geometry and magnetic configuration of compact gamma-ray sources, such as neutron stars or black holes. Thanks to the Integral coded mask imaging technics which efficiently suppresses most of the background contribution, we have measured linearly polarized emission from the brightest cosmic high energy sources, such as Gamma-Ray Bursts (GRB). These observations have enabled us to put strong constraints on the physical process at work in these sources. Models of Lorentz Invariance Violation (LIV) predict a energy-dependant rotation of the polarization angle along the photon path from the GRB site to Earth. Integral observation of polarized GRB have enable us to put strong constraints on these models. After a short review of Integral as a Compton polarimeter, I will describe these Integral results and their implication.
Characterization of Solute Distribution Following Iontophoresis from a Micropipet
Creators: name: Wightman, R. Mark
name: Kirkpatrick, Douglas C.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Iontophoresis uses a current to eject solution from the tip of a barrel formed from a pulled glass capillary and has been employed as a method of drug delivery for neurochemical investigations. Much attention has been devoted to resolving perhaps the greatest limitation of iontophoresis, the inability to determine the concentration of substances delivered by ejections. To further address this issue, we evaluate the properties of typical ejections such as barrel solution velocity and its relation to the ejection current using an amperometric and liquid chromatographic approach. These properties were used to predict the concentration distribution of ejected solute that was then confirmed by fluorescence microscopy. Additionally, incorporation of oppositely charged fluorophores into the barrel investigated the role of migration on the mass transport of an ejected species. Results indicate that location relative to the barrel tip is the primary influence on the distribution of ejected species. At short distances (<100 μm), advection from electroosmotic transport of the barrel solution may significantly contribute to the distribution, but this effect can be minimized through the use of low to moderate ejection currents. However, as the distance from the source increases (>100 μm), even solute ejected using high currents exhibits diffusion-limited behavior. Lastly a time-dependent theoretical model was constructed and is used with experimental fluorescent profiles to demonstrate how iontophoresis can generate near-uniform concentration distributions near the ejection source.
STUDY ON THE IMPROVEMENT METHOD OF ORGANIZATIONAL INNOVATION ABILITY BASED ON USER COLLABORATIVE INNOVATION FOR ELECTRICAL APPLIANCE
Creators: name: FENG CHUNYUAN
name: Dr. CHALERMPOL TAPSAI
Publisher: name: Zenodo
Year: 2024
Subjects: User Collaborative Innovation, Lead User, User Insight, Conceptual Decision-Making.

description: Abstract

This study investigates the integration of the lead user method and collaborative innovation method to improve enterprise product innovation management, a research area that remains underexplored in academia. The research focuses on key challenges such as identifying lead users, extracting and managing their innovative ideas, and integrating these ideas with expert insights to develop innovative product concepts. A structured model is proposed to examine the impact of five critical factors Customer. Using a mixed-method approach, including quantitative surveys of 434 participants and qualitative interviews with 15 experts, the study validates the model and identifies significant relationships among these factors. The results indicate that Customer Competence of Lead User and User Insight significantly influence Conceptual Collaboration Innovation Competence, which in turn positively affects User Collaborative Innovation. Additionally, Conceptual Decision-Making Competence and Innovative Leadership play crucial roles in enhancing collaborative innovation outcomes. The findings highlight that effective management of lead user insights, collaborative innovation processes, and decision-making competencies, supported by innovative leadership, significantly improves product innovation performance.
Investigating the Relationship between Burnout and Personality in Pharmacy Students
Creators: name: Owusu, Yaa
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2023

description: Introduction: To investigate the relationship between student’s personality traits, academic expectations, burnout, and engagement in student pharmacists 
Methods: A 48-question survey was administered to students in the didactic portion of the curriculum. The survey consists of questions from the Maslach Scale for Burnout, the Utrecht scale for Engagement, the Five Factor Personality, and demographics. 
Results: Fifty Doctors of Pharmacy Students participated in the survey. Burnout was negatively correlated with extroversion and conscientiousness. Engagement was positively correlated with conscientiousness.
Conclusion: This study was a start for finding internal correlations for burnout in pharmacy students. Due to the small sample size, further research is needed. Proper research and results will help school programs better understand and help students with burnout.
Immobilization of Lambda Exonuclease onto Polymer Micropillar Arrays for the Solid-Phase Digestion of dsDNAs
Creators: name: Weerakoon-Ratnayake, Kumuditha M.
name: Uba, Franklin I.
name: Oliver-Calixte, Nyoté J.
name: Soper, Steven A.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: The process of immobilizing enzymes onto solid supports for bioreactions has some compelling advantages compared to their solution-based counterpart including the facile separation of enzyme from products, elimination of enzyme autodigestion, and increased enzyme stability and activity. We report the immobilization of λ-exonuclease onto poly(methylmethacrylate) (PMMA) micropillars populated within a microfluidic device for the on-chip digestion of double-stranded DNA. Enzyme immobilization was successfully accomplished using 3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling to carboxylic acid functionalized PMMA micropillars. Our results suggest that the efficiency for the catalysis of dsDNA digestion using λ-exonuclease, including its processivity and reaction rate, were higher when the enzyme was attached to a solid support compared to the free solution digestion. We obtained a clipping rate of 1.0 × 103 nucleotides s–1 for the digestion of λ-DNA (48.5 kbp) by λ-exonuclease. The kinetic behavior of the solid-phase reactor could be described by a fractal Michaelis–Menten model with a catalytic efficiency nearly 17% better than the homogeneous solution-phase reaction. The results from this work will have important ramifications in new single-molecule DNA sequencing strategies that employ free mononucleotide identification.
Ultrasensitive and broadband MoS2 photodetector driven by ferroelectrics
Creators: name: Wang, Xudong
name: Wang, Peng
name: Wang, Jianlu
name: Hu, Weida
name: Zhou, Xiaohao
name: Guo, Nan
name: Huang, Hai
name: Sun, Shuo
name: Shen, Hong
name: Lin, Tie
name: Tang, Minghua
name: Liao, Lei
name: Jiang, Anquan
name: Sun, Jinglan
name: Meng, Xiangjian
name: Chen, Xiaoshuang
name: Lu, Wei
name: Chu, Junhao
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Photodetectors based on two dimensional materials have attracted growing interest. However, the sensitivity is still unsatisfactory even under high gate voltage. Here we demonstrate a MoS2 photodetector with a poly(vinylidene fluoride-trifluoroethylene) ferroelectric layer in place of the oxide layer in a traditional field effect transistor. The dark current of the photodetector is strongly suppressed by ferroelectric polarization. A high detectivity 2.21012 Jones) and photoresponsitivity (2570 A W) detector has been achieved under ZERO gate bias at a wavelength of 635 nm. Most strikingly, the band gap of few-layer MoS2 can be tuned by the ultra-high electrostatic field from the ferroelectric polarization. With this characteristic, photoresponse wavelengths of the photodetector are extended into the near infrared (0.85-1.55m). A ferroelectrics optoelectronics hybrid structure is an effective way to achieve high performance 2D electronic optoelectronic devices.
description: 35pages,4 figures
Construction of Training Sets for Valid Calibration of in Vivo Cyclic Voltammetric Data by Principal Component Analysis
Creators: name: Wightman, R. Mark
name: Rodeberg, Nathan T.
name: Carelli, Regina M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2015

description: Principal component regression, a multivariate calibration technique, is an invaluable tool for the analysis of voltammetric data collected in vivo with acutely implanted microelectrodes. This method utilizes training sets to separate cyclic voltammograms into contributions from multiple electroactive species. The introduction of chronically implanted microelectrodes permits longitudinal measurements at the same electrode and brain location over multiple recordings. The reliability of these measurements depends on a consistent calibration methodology. One published approach has been the use of training sets built with data from separate electrodes and animals to evaluate neurochemical signals in multiple subjects. Alternatively, responses to unpredicted rewards have been used to generate calibration data. This study addresses these approaches using voltammetric data from three different experiments in freely moving rats obtained with acutely implanted microelectrodes. The findings demonstrate critical iss...
The Effects of Cystic Fibrosis Disease Progression on Methicillin-Resistant Staphylococcus Aureus Extracellular Vesicles
Creators: name: Griffin, Megan
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2023

description: INTRODUCTION: Approximately one-fourth of cystic fibrosis (CF) cases are compromised by methicillin-resistant Staphylococcus aureus (MRSA). Extracellular vesicles (EVs) are membrane vesicles that can be found in MRSA pathogens and many other organisms as they are naturally released by most cell types. The functions of EVs such as antibiotic resistance and increased immunogenicity convey their potential to be used as biomarkers in CF progression. With characterization of the contents of these vesicles and understanding of their functions, it is believed that EVs can contribute to improvements in the treatment of CF.
METHODS: This was a single-center, translational, hypothesis-generating study. MRSA-infected respiratory secretions were obtained from five CF patients at UNC Medical Center. One sample taken before pulmonary exacerbation and one taken after exacerbation were obtained from each patient (N=10). MRSA EVs were isolated from each sample via ultracentrifugation from broth, and isolation methods were optimized to obtain vesicles with optimal purity. Vesicles were then analyzed under transmission electron microscopy (TEM) for analysis and quantification.
RESULTS: The vesicle isolation protocol required several rounds of optimization due to impurities in the resulting solution. TEM imaging produced images of two patients’ samples for analysis of the effectiveness of the isolation protocol and comparison before and after CF exacerbation. Both patients’ samples produced a visibly greater quantity of vesicles after exacerbation compared to before.
CONCLUSION: The quantity of MRSA EVs present in respiratory secretions increases in CF patients after pulmonary exacerbation, which may be due to antibiotic administration. Further research should be done to identify RNA and proteins present in the EVs in this setting and how they affect CF progression.
Developing small molecule PLC-γ2 activators
Creators: name: Meyer, Emma
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2023

description: An increasing number of Americans are living with Alzheimer’s disease, yet none of the existing therapies slow or reverse disease progression. Due to the rising burden of Alzheimer’s disease and limited treatment options, novel drug targets that stop damage to neurons are needed. Phospholipase C-γ2 (PLC-γ2) has recently been identified as a promising therapeutic target for treatment of Alzheimer’s disease, as one genetic variant has been associated with protective effects against cognitive impairment. The aims of this study were to confirm activity of selected PLC-γ2 hit compounds using a liposomal assay and cell-based inositol monophosphate (IP1) assay. The liposomal assay was used to further characterize hit compounds and characterize their potency and selectivity for PLC-γ2. For the IP1 assay, cells were cultured and treated with varying concentrations of hit compounds. The results show that compounds initially identified via high-throughput screening activate PLC-γ2 as demonstrated in a liposomal assay and a secondary assay utilizing IP1. The compounds identified show varying selectivity for PLC-γ2 over other PLC isozymes such as PLC-γ1. Further investigation of these compounds is being carried out through optimization of the IP1 assay in additional cell lines. Our work further supports PLC-γ2 as an important drug target and developing selective PLC-γ2 agonists will likely impact the field of AD therapeutics.