gebhart/patrepeval huggingface dataset:
Processing of composite fibers based on polypropylene and a thermotropic liquid crystalline polymer (1995)

Isotactic polypropylene (PP) was reinforced with Vectra B950 (VB), a thermotropic liquid crystalline polymer (TLCP), in two novel fiber spinning processes. In one process, a single VB melt stream was surrounded by a sheath of PP in a manner comparable to a wire coating process just prior to melt spinning to generate fibers possessing a sheath-core structure. The other process involved the distribution of continuous VB melt streams within a separately plasticated PP melt to form a composite melt which was drawn to create matrix-fibril fibers consisting of a PP matrix in situ reinforced with VB fibrils. Both processes allow polymers with non-overlapping processing temperatures to be combined and melt spun to form composite fibers. The effect of fiber draw ratio on the tensile mechanical properties was assessed for composite fibers reinforced with 50 wt.% (39 vol.%) VB. Numerical simulations of the non-isothermal fiber drawing processes and an investigation of fiber morphology were undertaken in order to explain the mechanical properties. The matrix-fibril (in situ) reinforced fibers were woven into fabric preforms. The preforms, pre-wetted with PP, were used to fabricate orthotropic composites, and the mechanical performance and formability of these composites was evaluated.
Role of Environment on the Shear-Induced Structural Evolution of MoS2 and Impact on Oxidation and Tribological Properties for Space Applications (2022)

This work investigates the role of water and oxygen on the shear-induced structural modifications of molybdenum disulfide (MoS<sub>2</sub>) coatings for space applications and the impact on friction due to oxidation from aging. We observed from transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) that sliding in both an inert environment (i.e., dry N<sub>2</sub>) or humid lab air forms basally oriented (002) running films of varying thickness and structure. Tribological testing of the basally oriented surfaces created in dry N<sub>2</sub> and air showed lower initial friction than a coating with an amorphous or nanocrystalline microstructure. Aging of coatings with basally oriented surfaces was performed by heating samples at 250 °C for 24 h. Post aging tribological testing of the as-deposited coating showed increased initial friction and a longer transition from higher friction to lower friction (i.e., run-in) due to oxidation of the surface. Tribological testing of raster patches formed in dry N<sub>2</sub> and air both showed an improved resistance to oxidation and reduced initial friction after aging. The results from this study have implications for the use of MoS<sub>2</sub>-coated mechanisms in aerospace and space applications and highlight the importance of preflight testing. Preflight cycling of components in inert or air environments provides an oriented surface microstructure with fewer interaction sites for oxidation and a lower shear strength, reducing the initial friction coefficient and oxidation due to aging or exposure to reactive species (i.e., atomic oxygen).
Much Enhanced Catalytic Reactivity of Cobalt Chlorin Derivatives on Two-Electron Reduction of Dioxygen to Produce Hydrogen Peroxide (2015)

Effects of changes in the redox potential or configuration of cobalt chlorin derivatives (Co(II)(Chn) (n = 1-3)) on the catalytic mechanism and the activity of two-electron reduction of dioxygen (O2) were investigated based on the detailed kinetic study by spectroscopic and electrochemical measurements. Nonsubstituted cobalt chlorin complex (Co(II)(Ch1)) efficiently and selectively catalyzed two-electron reduction of dioxygen (O2) by a one-electron reductant (1,1'-dimethylferrocene) to produce hydrogen peroxide (H2O2) in the presence of perchloric acid (HClO4) in benzonitrile (PhCN) at 298 K. The detailed kinetic studies have revealed that the rate-determining step in the catalytic cycle is the proton-coupled electron transfer reduction of O2 with the protonated Co(II)(Ch1) complex ([Co(II)(Ch1H)](+)), where one-electron reduction potential of [Co(III)(Ch1)](+) was changed from 0.37 V (vs SCE) to 0.48 V by the addition of HClO4 due to the protonation of [Co(III)(Ch1)](+). The introduction of electron-withdrawing aldehyde group (position C-3) (Co(II)(Ch3)) and both methoxycarbonyl group (position C-13(2)) and aldehyde group (position C-3) (Co(II)(Ch2)) on the chlorin ligand resulted in the positive shifts of redox potential for Co(III/II) from 0.37 V to 0.45 and 0.40 V, respectively, whereas, in the presence of HClO4, no positive shifts of those redox potentials for [Co(III)(Chn)](+)/Co(II)(Chn) (n = 2, 3) were observed due to lower acceptability of protonation. As a result, such a change in redox property resulted in the enhancement of the catalytic reactivity, where the observed rate constant (kobs) value of Co(II)(Ch3) was 36-fold larger than that of Co(II)(Ch1).
Reconfiguring the Quorum-Sensing Regulator SdiA ofEscherichia coliTo Control Biofilm Formation via Indole andN-Acylhomoserine Lactones (2009)

SdiA is a homolog of quorum-sensing regulators that detects N-acylhomoserine lactone (AHL) signals from other bacteria. Escherichia coli uses SdiA to reduce its biofilm formation in the presence of both AHLs and its own signal indole. Here we reconfigured SdiA (240 amino acids) to control biofilm formation using protein engineering. Four SdiA variants were obtained with altered biofilm formation, including truncation variants SdiA1E11 (F7L, F59L, Y70C, M94K, and K153X) and SdiA14C3 (W9R, P49T, N87T, frameshift at N96, and L123X), which reduced biofilm formation by 5- to 20-fold compared to wild-type SdiA in the presence of endogenous indole. Whole-transcriptome profiling revealed that wild-type SdiA reduced biofilm formation by repressing genes related to indole synthesis and curli synthesis compared to when no SdiA was expressed, while variant SdiA1E11 induced genes related to indole synthesis in comparison to wild-type SdiA. These results suggested altered indole metabolism, and corroborating the DNA microarray results in regard to indole synthesis, variant SdiA1E11 produced ninefold more indole, which led to reduced swimming motility and cell density. Also, wild-type SdiA decreased curli production and tnaA transcription, while SdiA1E11 increased tnaA transcription (tnaA encodes tryptophanase, which forms indole) compared to wild-type SdiA. Hence, wild-type SdiA decreased biofilm formation by reducing curli production and motility, and SdiA1E11 reduced biofilm formation via indole. Furthermore, an AHL-sensitive variant (SdiA2D10, having four mutations at E31G, Y42F, R116H, and L165Q) increased biofilm formation sevenfold in the presence of N-octanoyl-DL-homoserine lactone and N-(3-oxododecatanoyl)-L-homoserine lactone. Therefore, SdiA can be evolved to increase or decrease biofilm formation, and biofilm formation may be controlled by altering sensors rather than signals.
Clinical Trial of Quantitative Real‐Time Polymerase Chain Reaction for Detection of Cytomegalovirus in Peripheral Blood of Allogeneic Hematopoietic Stem‐Cell Transplant Recipients (2003)

The preemptive therapy of cytomegalovirus (CMV) reactivation is useful for the prevention of CMV disease in allogeneic hematopoietic stem-cell transplant (HSCT) recipients. We compared results of the pp65 CMV antigenemia test with quantitative touch-down polymerase chain reaction (Q-PCR) on unfractionated whole blood for the detection of CMV reactivation in 51 HSCT recipients. Forty episodes of reactivation in 28 patients were detected by antigenemia and treated by antiviral drugs. Q-PCR detected CMV DNA in 39 (97.5%) of 40 reactivation episodes. False-positive results occurred in 3% of tests, of which 63% were borderline positive. Q-PCR results were positive earlier than antigenemia results in 30 (77%) of 39 episodes detected by antigenemia. Q-PCR remained positive after treatment was discontinued in 14 (36%) of 39 episodes and predicted the return of CMV reactivation in 4 (31%) of 13 episodes. Q-PCR was more sensitive than the antigenemia test and had sufficient specificity for clinical use.
Injection-seeded Nd:YAG laser linewidth measurement using saturation spectroscopy in iodine (1989)

We describe the application of two-laser saturation spectroscopy in iodine for the measurement of the time-averaged linewidth of an injection-seeded Nd:YAG laser. Linewidths as narrow as 23 MHz have been measured. 2 refs., 1 fig.
Hybrid RF/LC Systems under QoS Constraints (2018)

The coexistence of radio frequency (RF) and visible light communications (VLC) in typical indoor environments can be leveraged to support vast user quality-of-service (QoS) needs. In this paper, we target a hybrid RF/VLC network in which data transmission is provided via either an RF access point or a VLC luminary based on a selection process. We employ the concept of effective capacity, which defines the maximum constant arrival data rate at the transmitter buffer when the QoS needs are imposed as limits on the buffer overflow and delay violation probabilities, as the main selection criteria. We initially formulate the effective capacity of both channels with respect to channel gains and user distribution. Under the assumption of uniform user distribution within the VLC cell, we then provide a closed-form approximation for the effective capacity of the VLC channel. We further investigate the effects of illumination needs and line-of-sight blockage on the VLC performance. In addition, we explore the non-asymptotic bounds regarding the buffering delay by capitalizing on the effective capacity. Through simulation results, we show the impacts of different physical aspects and datalink QoS needs on the effective capacity and delay bounds.
Carrier–envelope phase-tagged imaging of the controlled electron acceleration from SiO2nanospheres in intense few-cycle laser fields (2012)

Waveform-controlled light fields offer the possibility of manipulating ultrafast electronic processes on sub-cycle timescales. The optical lightwave control of the collective electron motion in nanostructured materials is key to the design of electronic devices operating at up to petahertz frequencies. We have studied the directional control of the electron emission from 95 nm diameter SiO2 nanoparticles in few-cycle laser fields with a well-defined waveform. Projections of the three-dimensional (3D) electron momentum distributions were obtained via single-shot velocity-map imaging (VMI), where phase tagging allowed retrieving the laser waveform for each laser shot. The application of this technique allowed us to efficiently suppress background contributions in the data and to obtain very accurate information on the amplitude and phase of the waveform-dependent electron emission. The experimental data that are obtained for 4 fs pulses centered at 720 nm at different intensities in the range (1–4) × 1013 W cm−2 are compared to quasi- classical mean-field Monte-Carlo simulations. The model calculations identify electron backscattering from the nanoparticle surface in highly dynamical localized fields as the main process responsible for the energetic electron emission from the nanoparticles. The local field sensitivity of the electron emission observed in our studies can serve as a foundation for future research on propagation effects for larger particles and field-induced material changes at higher intensities.
Gene Delivery and Transfection in Human Pancreatic Cancer Cells using Epidermal Growth Factor Receptor-targeted Gelatin-Based Engineered Nanovectors (2012)

More than 32,000 patients are diagnosed with pancreatic cancer in the United States per year and the disease is associated with very high mortality (1). Urgent need exists to develop novel clinically-translatable therapeutic strategies that can improve on the dismal survival statistics of pancreatic cancer patients. Although gene therapy in cancer has shown a tremendous promise, the major challenge is in the development of safe and effective delivery system, which can lead to sustained transgene expression. Gelatin is one of the most versatile natural biopolymer, widely used in food and pharmaceutical products. Previous studies from our laboratory have shown that type B gelatin could physical encapsulate DNA, which preserved the supercoiled structure of the plasmid and improved transfection efficiency upon intracellular delivery. By thiolation of gelatin, the sulfhydryl groups could be introduced into the polymer and would form disulfide bond within nanoparticles, which stabilizes the whole complex and once disulfide bond is broken due to the presence of glutathione in cytosol, payload would be released (2-5). Poly(ethylene glycol) (PEG)-modified GENS, when administered into the systemic circulation, provides long-circulation times and preferentially targets to the tumor mass due to the hyper-permeability of the neovasculature by the enhanced permeability and retention effect (6). Studies have shown over-expression of the epidermal growth factor receptor (EGFR) on Panc-1 human pancreatic adenocarcinoma cells (7). In order to actively target pancreatic cancer cell line, EGFR specific peptide was conjugated on the particle surface through a PEG spacer.(8) Most anti-tumor gene therapies are focused on administration of the tumor suppressor genes, such as wild-type p53 (wt-p53), to restore the pro-apoptotic function in the cells (9). The p53 mechanism functions as a critical signaling pathway in cell growth, which regulates apoptosis, cell cycle arrest, metabolism and other processes (10). In pancreatic cancer, most cells have mutations in p53 protein, causing the loss of apoptotic activity. With the introduction of wt-p53, the apoptosis could be repaired and further triggers cell death in cancer cells (11). Based on the above rationale, we have designed EGFR targeting peptide-modified thiolated gelatin nanoparticles for wt-p53 gene delivery and evaluated delivery efficiency and transfection in Panc-1 cells.
Accessible Crowdwork? (2015)

We present the first formal study of crowdworkers who have disabilities via in-depth open-ended interviews of 17 people (disabled crowdworkers and job coaches for people with disabilities) and a survey of 631 adults with disabilities. Our findings establish that people with a variety of disabilities currently participate in the crowd labor marketplace, despite challenges such as crowdsourcing workflow designs that inadvertently prohibit participation by, and may negatively affect the worker reputations of, people with disabilities. Despite such challenges, we find that crowdwork potentially offers different opportunities for people with disabilities relative to the normative office environment, such as job flexibility and lack of a need to rely on public transit. We close by identifying several ways in which crowd labor platform operators and/or individual task requestors could improve the accessibility of this increasingly important form of employment.
Control strategy of virtual synchronous generator based on virtual impedance and band-pass damping (2016)

This paper introduces a new control strategy to realize a virtual synchronous generator. The proposed control strategy is based on virtual impedance and band-pass damping algorithms to achieve the electro-mechanical characteristics of synchronous generator for the grid converter. Differences between new and traditional method on impedance emulation, and differences between traditional pure proportional damping algorithm and new band-pass damping algorithm are discussed as well. Additionally, detailed analysis of the components of synchronous generator is given, also the roles of the various parts of synchronous generator in the power system stability control are explained. The behavior of designed control strategy is validated by both simulations and experiments made on a 2kW grid-connected inverter.
Electron trapping time versus annealing temperature in low temperature grown GaAs (2003)

We report in our study the carrier trapping time versus different annealing temperature, which will be important for LT-GaAs application on high speed telecommunication devices. The samples investigated are l-/spl mu/m-thick MBE-grown LT-GaAs films sandwiched between two AlAs layers with a growing temperature of 220 C.
Identification of distinct, ligand‐specific structural changes in a G protein‐coupled receptor (2007)

G protein‐coupled receptors (GPCRs) represent by far the largest class of cell surface receptors. The conformational changes in GPCR structure induced by GPCR ligands (agonists, neutral antagonists, or inverse agonists) are not well understood at present. In this study, we employed an in situ disulfide cross‐linking strategy to monitor ligand‐induced conformational changes in a series of cysteine (Cys)‐substituted mutant M3 muscarinic acetylcholine receptors. We demonstrated that muscarinic agonists inhibited disulfide cross‐linking in the A91C/T549C and F92C/F550C double Cys mutant M3 receptors. In striking contrast, inverse muscarinic agonists enhanced disulfide bond formation in the same receptor constructs. Given the predicted localization of the Cys residues present in these mutant receptors, our data strongly suggest that muscarinic agonists trigger a separation of the N‐terminal segment of the cytoplasmic tail from the cytoplasmic end of transmembrane domain I (TM I), whereas inverse muscarinic agonists increase the proximity between these two receptor regions. These findings provide a structural basis for the opposing biological effects of muscarinic agonists and inverse agonists. This study also provides the first piece of direct structural information as to how the receptor conformations induced by these two functionally different classes of ligands differ at the molecular level. This work was supported by the Intramural Research Program of the NIDDK, NIH
Attosecond Metrology with Controlled Light Waveforms (2005)

Young sports medicine patients reported significant physical and emotional symptoms associated with COVID-related surgical delays. Patients were most concerned about delays resulting in missed sport seasons. Those who reported greater levels of concern with surgical delays reported more emotional symptoms and higher levels of psychological stress. <b>Clinical Relevance</b>: It is important to understand the impact of delayed elective surgical treatment on young patients due to COVID. This study will allow us to make more informed choices for patients during the pandemic.
Thermally stimulated depolarisation current calculated from isothermal dielectric response functions (2002)

Thermally stimulated depolarisation (TSD) currents are modelled from dielectric response functions deduced from isothermal measurements. The key assumption is that the same state of polarisation can be achieved both via the real non-isothermal TSD process or via an equivalent isothermal process. The change of polarisation with temperature and time is traced through a continuous adjustment of the starting and stopping times and polarising field of the fictitious isothermal process. The theory is applicable to general non-Debye relaxation and variable activation energies. A comparison is made with experimental data on polyethylene terephtalate films.
Nitrogen and Phosphorus Co‐doped Nanoporous Carbons from Phosphoprotein/Silica Self‐Assemblies for Energy Storage in Supercapacitors (2020)

Abstract In this work, nanoporous, heteroatom‐doped carbon materials with tailorable structures and excellent charge/energy storage properties are synthesized using casein (a phosphoprotein) as a precursor and silica gel as a template via a facile synthetic route. The synthesis involves carbonization and etching. In the synthesis, an appreciable amount of the N and P atoms in casein make it as dopants into the nanoporous carbons, enabling the materials to efficiently store charge. The structures and compositions as well as the overall charge storage properties of the materials are easily tuned by varying the relative amount of silica gel template used with casein in the precursors. By using an optimal amount of silica in the casein/silica self‐assemblies, a nanoporous carbon with low resistance to Faradaic processes and good capacitance and pseudocapacitance is obtained. This material gives a capacitance of ca . 261 F g −1 at 1 A g −1 , which is higher than those of many recently reported carbon materials in the literature. Moreover, the material retains 95 % of the initial capacitance with ca . 100 % of coulombic efficiency after 10,000 charge‐discharge cycles.
Design of 3D-Printed Titanium Compliant Mechanisms (2014)

This paper describes 3D-printed titanium compliant mechanisms for aerospace applications. It is meant as a primer to help engineers design compliant, multi-axis, printed parts that exhibit high performance. Topics covered include brief introductions to both compliant mechanism design and 3D printing in titanium, material and geometry considerations for 3D printing, modeling techniques, and case studies of both successful and unsuccessful part geometries. Key findings include recommended flexure geometries, minimum thicknesses, and general design guidelines for compliant printed parts that may not be obvious to the first time designer.
Solid State NMR Studies on Inhomogeneous Structure of Fibre Wall in Kraft Pulp (2001)

Summary Solid state NMR spectroscopy was used to analyse the inhomogeneous structure of kraft fibre. Primary fines, isolated from the original kraft pulp, and secondary fines, isolated after refining, were compared with the corresponding long fibres. To fractionate fibre wall surface material, the kraft pulp was refined in stages. After each stage, the secondary fines and long fibres were separated and the long fibres refined again to peel off the surface material. It was found that the crystallinity of cellulose is lower in fines compared with the corresponding long fibres. When the fines fractions were compared with each other, the cellulose crystallinity was observed to increase towards the inner parts of the fibre surface. A very clear gradient was also seen in the amount of extractives, which was highest in the primary fines rich in ray cells. The contents of lignin and some hemicelluloses, mainly xylan and glucomannan, were also higher in fines. Residual lignin isolated from the fines was found to be slightly more condensed than residual lignin from long fibres.
Paper #58: T2 Mapping and Functional Outcome of Patients With Medial Knee Osteoarthritis After the Use of Unloader Bracing (2013)

Medial unloader bracing provides small, subjective improvements in patients with unicompartmental osteoarthritis; these improvements are likely not due to physiological changes in articular cartilage.
Effect of nanogroove geometry on adipogenic differentiation (2011)

We present the effect of nanotopographically defined surfaces on adipocyte differentiation using various nanogroove patterns. Parallel nanogroove arrays with equal inter-groove distance (400, 550, 800 nm width) and varying distances (550 nm width with three different spacings of 550, 1100, and 2750 nm) were fabricated by UV-assisted capillary force lithography (CFL) on 18 mm diameter glass coverslips using biocompatible polyurethane (PU)-based material. After coating with fibronectin and subsequent culture of 3T3-L1 preadipocytes, the degree of adipocyte differentiation was determined by Oil Red O staining and adipogenic gene expression. We observed that adipocyte differentiation was slightly but substantially affected by culture on various nanogrooved surfaces. In particular, the cell crawling into nanogrooves contributed substantially to an enhanced level of differentiation with higher contact guidance, suggesting that cell-to-surface interactions would play a role for the adipocyte differentiation.