gebhart/patrepeval huggingface dataset:
Operating Current Mode Dependence of Luminescence Properties of Rubrene-doped Yellow Organic Light Emitting Diodes (2000)

The operating current mode dependence of luminescence properties of rubrene-doped yellow organic light-emitting diodes (OLEDs) was investigated. The devices were driven by three types of constant current mode: a simple direct current (DC) mode, a simple alternating current (AC) mode and a pulsed current (PC) mode. The device driven by the AC mode showed low energy efficiency because of the existence of time intervals with no emission in spite of energy consumption. The device driven by the PC mode showed the highest efficiency and better stability compared with the devices driven by the other modes.
Intermolecular and intramolecular hydrogen bonding of poly(dimethylsiloxane)urethane‐graft–poly(methyl methacrylate) copolymers based on 2,4‐TDI and m‐XDI (2002)

Abstract In this study, poly(dimethylsiloxane)urethane–graft–poly(methyl methacrylate) (PDMS urethane–g–PMMA) copolymers with low crosslinking density were synthesized. Glass transition temperatures of the copolymers were investigated by dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). Results confirm that PDMS urethane–g–PMMA is miscible in the 2,4‐TDI (2,4‐ toluene diisocyanate) system, whereas it is partially miscible in the m ‐XDI ( m ‐xylene diisocyanate) system. Free, intra‐ (urethane–urethane), and inter‐ (urethane–ester) association hydrogen bonding exist in the urethane group of copolymers. The inter‐association hydrogen bonding can improve the compatibility of the copolymer components. The relationship between the frequency shift and enthalpy confirm the distribution of hydrogen bonding in the macromonomer and copolymer. Ninety percent of the hydrogen bonding is by interassociation in the 2,4‐TDI system. The intra‐association hydrogen bonding in the m ‐XDI system is higher than that in the 2,4‐TDI system. Consequently, aggregation may occur easily in the siloxane‐grafted chain in the m ‐XDI system. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 962–972, 2002
Supplementary Figure 1 from Analysis of Mitosis and Antimitotic Drug Responses in Tumors by <i>In Vivo</i> Microscopy and Single-Cell Pharmacodynamics (2023)

Supplementary Figure 1 from Analysis of Mitosis and Antimitotic Drug Responses in Tumors by &lt;i&gt;In Vivo&lt;/i&gt; Microscopy and Single-Cell Pharmacodynamics
Does Gibberellic Acid Induce the Transfer of Lipase from Protein Bodies to Lipid Bodies in Barley Aleurone Cells? (1987)

We have examined the effect of gibberellic acid (GA(3)) on the distribution of the enzyme responsible for mobilizing storage triacylglycerol in aleurone cells of Hordeum vulgare L. cv Himalaya. Using cellular fractionation techniques, we find that, in cells that have not been exposed to hormone, neutral lipase activity is principally associated with a pellet containing the membranes of protein bodies. If the cells are exposed to GA(3) for at least 1 hour, the majority of the lipase activity becomes associated with the lipid body fraction. The nature of the in vivo association between lipid bodies and protein bodies was examined using ultrarapid freezing followed by freeze-fracture electron microscopy. Our analysis indicates that the phospholipid monolayer surrounding the lipid body is directly continuous with the outer leaflet of the bilayer surrounding the protein body. Based on our data, we propose that lipase can be transferred from protein bodies (storage form) to lipid bodies (active form) by lateral diffusion within the plane of the fused phospholipid monolayer, and that the transfer can be controlled by gibberellic acid by an unknown mechanism.
Supporting the notion of seamlessness in personal content management (2007)

The virtually ubiquitous always-on connectivity with mobile devices has enabled remote access to geographically distributed data providing anytime, anywhere access and potentially unlimited storage for personal digital content However, the user motives, the available devices, and the available connection types vary from one situation to another. In this paper, we discuss the characteristics of the user's notion of seamlessness when accessing the distributed content and the means supporting it. In addition, we propose guidelines for designing seamless mobile user experience with personal content.
Overview of Multi-Kilowatt Free-Piston Stirling Power Conversion Research at GRC (2008)

As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free‐piston Stirling convertors and a pair of commercially available pressure wave generators (which will be plumbed together to create a high power Stirling linear alternator test rig) have been procured for in‐house testing at Glenn Research Center. Delivery of both the Stirling convertors and the linear alternator test rig is expected by October, 2007. The 1 kW class free‐piston Stirling convertors will be tested at GRC to map and verify performance. The convertors will later be modified to operate with a NaK liquid metal pumped loop for thermal energy input. The high power linear alternator test rig will be used to map and verify high power Stirling linear alternator performance and to develop power management and distribution (PMAD) methods and techniques. This paper provides an overview of the multi‐kilowatt free‐piston Stirling power conversion work being performed at GRC.
Genetic variant in theHSPB1 promoter region impairs the HSP27 stress response (2007)

The 27 kDa heat shock protein 1 (HSP27) is a member of the ubiquitously expressed small heat shock protein family and has pleiotropic cytoprotective functions. Since HSP27 may act as a motor neuron survival factor, we analyzed the genetic contribution of the human HSPB1 gene (HSPB1) to the etiology of amyotrophic lateral sclerosis (ALS). In a cohort of sporadic ALS patients, we identified three rare genetic variations and one of which (c.-217T>C) targeted a conserved nucleotide of the Heat Shock Element (HSE) in the HSPB1 promoter. Since binding of Heat Shock Factor 1 (HSF1) to this HSE is essential for stress-induced transcription of HSPB1, we examined the effect of the c.-217C allele on transcriptional activity and HSF binding. The basal promoter activity of the HSPB1 c.-217C mutant allele decreased to 50% as compared to the wild-type promoter in neuronal and non-neuronal cells. Following heat shock, the HSE variant attenuated significantly the stress-related increase in transcription. Electrophoretic mobility shift assays demonstrated a dramatically reduced HSF-binding to the c.-217C mutant allele as compared to the c.-217T wild-type allele. In conclusion, our study underscores the importance of the c.-217T nucleotide for HSF binding and heat inducibility of HSPB1. Therefore, our study suggests that the functional HSPB1 variant may represent a genetic modifier in the pathogenesis of motor neuron disease; however, it is necessary to confirm this HSPB1 variant in additional ALS patients.
Portfolio-driven Resource Management for Transient Cloud Servers (2017)

Cloud providers have begun to offer their surplus capacity in the form of low-cost transient servers, which can be revoked unilaterally at any time. While the low cost of transient servers makes them attractive for a wide range of applications, such as data processing and scientific computing, failures due to server revocation can severely degrade application performance. Since different transient server types offer different cost and availability tradeoffs, we present the notion of server portfolios that is based on financial portfolio modeling. Server portfolios enable construction of an "optimal" mix of severs to meet an application's sensitivity to cost and revocation risk. We implement model-driven portfolios in a system called ExoSphere, and show how diverse applications can use portfolios and application-specific policies to gracefully handle transient servers. We show that ExoSphere enables widely-used parallel applications such as Spark, MPI, and BOINC to be made transiency-aware with modest effort. Our experiments show that allowing the applications to use suitable transiency-aware policies, ExoSphere is able to achieve 80% cost savings when compared to on-demand servers and greatly reduces revocation risk compared to existing approaches.
Synthesis of New Cationic Lipids from an Unsaturated Glycoside Scaffold (2001)

[see structure]. We report the synthesis of new cationic lipids. These amphiphiles present a hydrophobic domain connected to a guanidinium entity by an unsaturated glycoside scaffold. The synthetic strategy using amide or acetal linkage led to various mono- and bicatenar derivatives. Investigation of their physicochemical properties indicated that these new compounds compact DNA.
Geospatial-Temporal Semantic Graphs for Automated Wide-Area Search (2017)

We address the problem of wide-area search of overhead imagery. Given a time sequence of overhead images, we construct a geospatial-temporal semantic graph, which expresses the complex continuous information in the overhead images in a discrete searchable form, including explicit modeling of changes seen from one image to the next. We can then express desired search goals as a template graph, and search for matches using simple and efficient graph search algorithms. This produces a set of potential matches which provide cues for where to examine the imagery in detail, applying human expertise to determine which matches are correct. We include a match quality metric that scores the matches according to how well they match the stated search goal. This enables matches to be presented in sorted order with the best matches first, similar to the results returned by a web search engine. We present an evaluation of the method applied to several examples and data sets, and show that it can be used successfully for some problems. We also remark on several limitations of the method and note additional work needed to improve its scope and robustness. Approved for public release; further dissemination unlimited.
Magnetic field-controlled gene expression in encapsulated cells (2011)

Cell and gene therapies have an enormous range of potential applications, but as for most other therapies, dosing is a critical issue, which makes regulated gene expression a prerequisite for advanced strategies. Several inducible expression systems have been established, which mainly rely on small molecules as inducers, such as hormones or antibiotics. The application of these inducers is difficult to control and the effects on gene regulation are slow. Here we describe a novel system for induction of gene expression in encapsulated cells. This involves the modification of cells to express potential therapeutic genes under the control of a heat inducible promoter and the co-encapsulation of these cells with magnetic nanoparticles. These nanoparticles produce heat when subjected to an alternating magnetic field; the elevated temperatures in the capsules then induce gene expression. In the present study we define the parameters of such systems and provide proof-of-principle using reporter gene constructs. The fine-tuned heating of nanoparticles in the magnetic field allows regulation of gene expression from the outside over a broad range and within short time. Such a system has great potential for advancement of cell and gene therapy approaches.
Classical antigen presentation by HLA-A2 of Mycobacterium tuberculosis derived ligands (106.40) (2012)

Abstract Mycobacterium tuberculosis (Mtb) remains a world health threat, with 8.8 million cases reported in 2010, 65% of which were new and recurrent cases of tuberculosis . Cellular immunity is critical for controlling Mtb and recent studies identify CD8+ T cells as important players in controlling infection. Cytotoxic T lymphocytes (CTLs) recognize peptide antigen presented by Major Histocompatibility Complex (MHC) Class I molecules and destroy infected cells, therefore discovery of CTL epitopes is of high importance. Using a method of soluble HLA production, we were able to generate soluble HLA-A2 from THP-1 monocyte cell lines transfected with a soluble form of HLA A*02:01. Transfected cells were seeded into a hollow fiber bioreactor and were infected with Mtb or left uninfected. Following production of 25 mgs of HLA-A2 from infected and uninfected cells, peptides were eluted from the supernatants of uninfected and infected cells. Peptides from each group were fractionated using HPLC and analyzed by mass spectrometry. We were able to identify six Mtb derived ligands presented by the MHC Class I molecule HLA-A*0201, two of which reacted well with donor PBMC from patients with both active and latent Mtb infection. Identifying new vaccine candidates is a top priority in the TB field and the reactive Mtb ligands identified here demonstrate that multiple Mtb proteins are processed for presentation by Class I HLA and a fraction of these ligands are immunologically reactive.
Knockout Packet Loss Probability Analysis of SCWP Optical Packet Switching Wavelength Distributed Knockout Architecture (2005)

The deployment of optical packet switching (OPS) in dense wavelength division multiplexing (DWDM) backbone networks is perceived as a medium term promising alternative. Scalability restrictions imply that conventional switching architectures are unfeasible in this large-scale scenario. In a previous paper, the wavelength-distributed knockout architecture was proposed as a cost-effective scaling strategy for OPS switching fabrics. In this paper, this growable architecture is applied to OPS switching fabrics able to emulate output buffering. We also propose an scheduling algorithm which provides optimum performance if knockout packet losses are made negligible. The mathematical analysis to evaluate the knockout packet loss probability of this architecture is obtained, under uniform and non-uniform traffic patterns. To complement the switch dimensioning process, an upper bound assuring 0-knockout packet losses is compared with the exact analytical results.
The roles of polymer relaxation phenomena, aqueous dye solubility and the physical properties of water in the mechanism of adsorption of a disperse dye on poly(ethylene terephthalate) fibres: Part 2 dye solubility (2022)

Abstract The marked temperature‐dependent uptake of a commercial disperse dye on poly(ethylene terephthalate) fabric achieved during an aqueous high temperature dyeing process is the likely amalgamation of at least two separate, but intrinsically inter‐related, thermally activated processes, namely, poly(ethylene terephthalate) structural relaxations, as articulated in terms of polymer chain segmental mobility and available free volume, in which glass transition adopts a principal role, as well as disperse dye aqueous solubility. Both polymer relaxation times and disperse dye solubility therefore assume crucially important roles in the mechanism of adsorption of disperse dyes on poly(ethylene terephthalate) fibres.
Epigenetics in the Extreme: Prions and the Inheritance of Environmentally Acquired Traits (2010)

Prions are an unusual form of epigenetics: Their stable inheritance and complex phenotypes come about through protein folding rather than nucleic acid-associated changes. With intimate ties to protein homeostasis and a remarkable sensitivity to stress, prions are a robust mechanism that links environmental extremes with the acquisition and inheritance of new traits.
A Coordination Chemistry Approach to a Multieffector Enzyme Mimic (2007)

A macrocyclic complex, formed via the weak-link approach, behaves as a multieffector enzyme mimic in the context of pseudorotaxane formation. The complex has Rh metal centers as regulatory sites, which can be used to change the size and charge of the cavity responsible for pseudorotaxane formation. The first binding events on the metal center (M) involving CO (the filled squares) change the shape of the molecule, while the second binding event involving Cl anion (the filled circles) changes the charge on the molecule and its ability to recognize and sequester a hexyl viologen guest molecule (G).
Molecular Basis of Ligand-Dependent Regulation of NadR, the Transcriptional Repressor of Meningococcal Virulence Factor NadA (2016)

Neisseria adhesin A (NadA) is present on the meningococcal surface and contributes to adhesion to and invasion of human cells. NadA is also one of three recombinant antigens in the recently-approved Bexsero vaccine, which protects against serogroup B meningococcus. The amount of NadA on the bacterial surface is of direct relevance in the constant battle of host-pathogen interactions: it influences the ability of the pathogen to engage human cell surface-exposed receptors and, conversely, the bacterial susceptibility to the antibody-mediated immune response. It is therefore important to understand the mechanisms which regulate nadA expression levels, which are predominantly controlled by the transcriptional regulator NadR (Neisseria adhesin A Regulator) both in vitro and in vivo. NadR binds the nadA promoter and represses gene transcription. In the presence of 4-hydroxyphenylacetate (4-HPA), a catabolite present in human saliva both under physiological conditions and during bacterial infection, the binding of NadR to the nadA promoter is attenuated and nadA expression is induced. NadR also mediates ligand-dependent regulation of many other meningococcal genes, for example the highly-conserved multiple adhesin family (maf) genes, which encode proteins emerging with important roles in host-pathogen interactions, immune evasion and niche adaptation. To gain insights into the regulation of NadR mediated by 4-HPA, we combined structural, biochemical, and mutagenesis studies. In particular, two new crystal structures of ligand-free and ligand-bound NadR revealed (i) the molecular basis of 'conformational selection' by which a single molecule of 4-HPA binds and stabilizes dimeric NadR in a conformation unsuitable for DNA-binding, (ii) molecular explanations for the binding specificities of different hydroxyphenylacetate ligands, including 3Cl,4-HPA which is produced during inflammation, (iii) the presence of a leucine residue essential for dimerization and conserved in many MarR family proteins, and (iv) four residues (His7, Ser9, Asn11 and Phe25), which are involved in binding 4-HPA, and were confirmed in vitro to have key roles in the regulatory mechanism in bacteria. Overall, this study deepens our molecular understanding of the sophisticated regulatory mechanisms of the expression of nadA and other genes governed by NadR, dependent on interactions with niche-specific signal molecules that may play important roles during meningococcal pathogenesis.
Production of polyolefins with controlled long chain branching and molecular weight distributions using mixed metallocene catalysts (2001)

Polyethylene with long-chain branches can be produced with certain metallocene catalysts, such as monocyclopentadienyl derivatives, by incorporation of macromonomers formed in-situ into the polymer backbone. This investigation demonstrates how dual metallocene systems can be used to control and enhance the level of long chain branching of polyethylene made with these catalysts. For instance, a catalyst that favors long chain branch formation, such as Dow's constrained geometry catalyst, can be combined with another metallocene that produces macromonomers at a faster rate. In this way, the concentration of macromonomers in the reactor increases, thus favoring the formation of long chain branches. This leads, however, to a complex microstructural control problem, since both the molecular weight and long chain branch distribution are affected simultaneously by the presence of the second catalyst. Several mathematical models will be used to describe this challenging microstructural control problem.
Optical fiber-fault surveillance for passive optical networks in S-band operation window (2005)

An S-band (1470 to 1520 nm) fiber laser scheme, which uses multiple fiber Bragg grating (FBG) elements as feedback elements on each passive branch, is proposed and described for in-service fault identification in passive optical networks (PONs). By tuning a wavelength selective filter located within the laser cavity over a gain bandwidth, the fiber-fault of each branch can be monitored without affecting the in-service channels. In our experiment, an S-band four-branch monitoring tree-structured PON system is demonstrated and investigated experimentally.
Unrecognized Pretransplant and Donor‐Derived Cryptococcal Disease in Organ Transplant Recipients (2010)

A subset of SOT recipients with cryptococcosis present very early after transplantation with disease that appears to occur preferentially in liver transplant recipients and involves unusual sites, such as the transplanted organ or the surgical site. These patients may have unrecognized pretransplant or donor-derived cryptococcosis.
Expression pattern of aspartic proteinase antigens in aspergilli (1996)

Sporulating colonies of Aspergillus fumigatus, A. flavus, and A. niger were subjected to immunofluorescence using specific polyclonal antibodies against the aspergillopepsin PEP (EC 3.4.23.18), a secretory aspartic proteinase produced by A. fumigatus. The proteinase antigen was found mainly in developing conidiophores of aspergilli, in submerged mycelia and on the tips of growing aerial mycelia. Mature aerial hyphae and spores showed no immunofluorescence at all. Sporulating conidiophores revealed only weak activity in A. fumigatus and A. flavus. The distinct pattern of expression of the aspartic proteinase antigens suggests a role for such enzymes in the growth of hyphae and the development of conidiophores and thus for the sporulation process in aspergilli.
Fabricating PFPE Membranes for Microfluidic Valves and Pumps (2009)

A process has been developed for fabricating membranes of a perfluoropolyether (PFPE) and integrating them into valves and pumps in laboratory-on-achip microfluidic devices. Membranes of poly(tetrafluoroethylene) [PTFE] and poly(dimethylsilane) [PDMS] have been considered for this purpose and found wanting. By making it possible to use PFPE instead of PTFE or PDMS, the present process expands the array of options for further development of microfluidic devices for diverse applications that could include detection of biochemicals of interest, detection of toxins and biowarfare agents, synthesis and analysis of proteins, medical diagnosis, and synthesis of fuels.
Quantitative estimation of liver attenuation and echogenicity: normal state versus diffuse liver disease. (1987)

A method based on broad-band amplitude for obtaining attenuation and echogenicity estimates from homogeneous phantoms and tissues is described. Although a number of assumptions about the beam and scattering properties must be made, the attenuation results are as accurate as those obtained by the spectral-difference method and show less variability. The method was applied to the livers of 18 healthy volunteers and 76 patients with liver disease, including 29 patients with chronic hepatitis and 30 patients with Gaucher disease. Patients with chronic hepatitis formed a bimodal distribution, with one group having lower than normal attenuation and echogenicity values and another having elevated values. Six patients with type I glycogen storage disease and fatty infiltration of the liver had highly attenuating, echogenic livers as did patients with fatty livers from other causes. This finding confirms the subjective impressions already reported in the literature. In contrast to previous literature reports, patients with cirrhosis had normal attenuation and echogenicity values. Reasons for this discrepancy are discussed.