gebhart/patrepeval huggingface dataset:
Composite Properties of Polyimide Resins Made From Salt-Like Solution Precursors (1998)

Recent work in high temperature materials at NASA Langley Research Center (LaRC\TM) have led to the development of new polyimide resin systems with very attractive properties. The majority of the work done with these resin systems has concentrated on determining engineering mechanical properties of composites prepared from a poly(amide acid) precursor. Three NASA Langley-developed polyimide matrix resins, LaRC\TM-IA, LaRC\TM-IAX, and LaRC\TM-8515, were produced via a salt-like process developed by Unitka Ltd. The salt-like solutions (sixty-five percent solids in NMP) were prepregged onto Hexcel IM7 carbon fiber using the NASA LaRC\TM Multipurpose Tape Machine. Process parameters were determined and composite panels fabricated. Mechanical properties are presented for these three intermediate mudulus carbon fiber/polyimide matrix composites and compared to existing data on the same polyimide resin systems and IM7 carbon fiber manufactured via poly(amide acid) solutions (thirty-five percent solids in NMP). This work studies the effects of varying the synthetic route on the processing and mechanical properties of polyimide composites.
Intracellular integration of synthetic nanostructures with viable cells for controlled biochemical manipulation (2003)

We demonstrate the integration of vertically aligned carbon nanofibre (VACNF) elements with the intracellular domains of viable cells for controlled biochemical manipulation. Deterministically synthesized VACNFs were modified with either adsorbed or covalently-linked plasmid DNA and were subsequently inserted into cells. Post insertion viability of the cells was demonstrated by continued proliferation of the interfaced cells and long-term (> 22 day) expression of the introduced plasmid. Adsorbed plasmids were typically desorbed in the intracellular domain and segregated to progeny cells. Covalently bound plasmids remained tethered to nanofibres and were expressed in interfaced cells but were not partitioned into progeny, and gene expression ceased when the nanofibre was no longer retained. This provides a method for achieving a genetic modification that is non-inheritable and whose extent in time can be directly and precisely controlled. These results demonstrate the potential of VACNF arrays as an intracellular interface for monitoring and controlling subcellular and molecular phenomena within viable cells for applications including biosensors, in vivo diagnostics, and in vivo logic devices.
Inhibition of epidermal growth factor receptor restores decidualization markers in stromal fibroblasts from women with endometriosis (2014)

Purpose Decidualization comprises specific biochemical and morphological changes in uterine endometrium essential for establishment of pregnancy. This process is abnormal in women with endometriosis, a disorder in which endometrial-like tissue is present outside the uterus. The aim of this study was to restore cAMP-induced decidualization marker expression in endometrial stromal fibroblasts from women with endometriosis by using chemical inhibitors to PI3K/AKT/mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK) and epidermal growth factor receptor (EGFR) signaling pathways in vitro. Methods Endometrial stromal fibroblasts (eSF) from women with (eSF endo ) and without (eSF non-endo ) endometriosis were treated with inhibitors to EGFR tyrosine kinase (gefitinib), mTOR (rapamycin) and MAPK kinase 1/2 (MEK1/2) (UO126) during 8-bromoadenosine 3′,5′-cyclic monophosphate (8-br-cAMP)–stimulated decidualization. Decidualization was assessed by evaluating expression of insulin growth factor binding protein 1 (IGFBP1), prolactin (PRL) and forkhead box protein O1A (FOXO1A) by quantitative real-time PCR. Results Gefitinib restored expression of decidualization markers in eSF endo to levels consistent with those in eSF non-endo . Elevated levels of phosphorylated mTOR in eSF endo were reduced to levels found in eSF non-endo , by gefitinib during treatment with 8-br-cAMP. Additional gene expression analyses suggested dysregulation of EGFR negative feedback regulators in eSF endo . Conclusions Results implicate EGFR signaling as an underlying cause for aberrant cAMP-induced decidualization in women with endometriosis, and provide a potential target for management of infertility associated with the disease. The reduction of p-mTOR levels in eSF endo during 8-br-cAMP treatment suggests cooperation between EGR and protein kinase A signaling in the regulation of mTOR in eSF.
Synthesis and Structure-Activity Relationships of New (5R,8R,10R)-Ergoline Derivatives with Antihypertensive or Dopaminergic Activity. (1994)

A series of new (5R,8R,10R)-ergoline derivatives was synthesized, and their antihypertensive and dopaminergic activities were tested in conscious spontaneously hypertensive rats and in rats with unilateral 6-hydroxydopamine-induced lesions of the substantia nigra. (5R,8R,10R)-6-Alkyl-8-ergolinemethanols, prepared from the corresponding ergolinecarboxylates, were converted to the tosylates, which were treated with various five-membered heterocycles containing nitrogen atoms to afford the new ergolines. (5R,8R,10R)-8-(1,2,4-Triazol-1-ylmethyl)-6-methylergoline (4s, maleate: BAM-1110) exhibited potent dopaminergic activity, about 18-fold greater than that of bromocriptine mesylate. (5R,8R,10R)-8-(1,2,4-Triazol-1-ylmethyl)-6-propylergoline (8b, fumarate: BAM-1602) showed extremely potent dopaminergic activity, being about 220 and 1.15 times more active than bromocriptine mesylate and pergolide mesylate, respectively. Several compounds exhibited potent antihypertensive activity. Structure-activity relationships for antihypertensive and dopaminergic activities are discussed.
Chemistry of lignin-based materials (2012)

There is a need for renewable resources as a raw material for commodity polymers. Lignin is one of the most important natural biopolymers from renewable resources due to its sufficient supply, robust material properties and the fact that its use does not compete with the food supply. Lignin has been investigated since the late 19th century, but its applications are limited due to poor processability, low reactivity and intrinsic heterogeneity depending on the plant source and isolation methods used. Current strategies for using lignin in modern materials center on integrating it with other natural or synthetic polymers. This review article introduces the technological importance of lignin and focuses on copolymers and blends based on lignin in a broad range of applications.
Aluminosilicate mesostructures with improved acidity and hydrothermal stability (2002)

Significant improvements in both the hydrothermal stability and the acidity of mesostructured aluminosilcates have been reported recently. New assembly pathways, along with post-synthesis treatment methods, have made it possible to form structures with thick and more highly crosslinked framework walls. The resulting structures are slow to degrade under hydrothermal conditions in comparison to conventional analogs. Also, improved methodologies for grafting Al centers into the walls of pre-assembled frameworks have afforded aluminosilicate mesostructures with enhanced acidity. The most promising strategy for improving the hydrothermal stability and acidity of aluminosilicate mesostructures, however, is based on the use of protozeolitic nanoclusters. These so-called “zeolite seeds” can be directly assembled into hexagonal, cubic, wormhole, and foamlike framework structures under a variety of assembly conditions. They also can be grafted into the walls of pre-assembled frameworks to form more stable acidic derivatives.
Characterization of an Immunodominant Antigenic Site on GB Virus C Glycoprotein E2 That Is Involved in Cell Binding (2006)

GB virus type C (GBV-C) is a human flavivirus that may cause persistent infection, although most infected individuals clear viremia and develop antibodies to the envelope glycoprotein E2. To study GBV-C E2 antigenicity and cell binding, murine anti-E2 monoclonal antibodies (MAbs) were evaluated to topologically map immunogenic sites on GBV-C E2 and for the ability to detect or block recombinant E2 binding to various cell lines. Five competition groups of MAbs were identified. Groups I and II did not compete with each other. Group III competed with both groups I and II. Group IV did not compete with group I, II, or III. One MAb competed with all of the other MAbs, suggesting that the epitopes bound by these MAbs are intimately related. Individually, none of the MAbs competed extensively with polyclonal human convalescent antibody (PcAb); however, combinations of all five MAb groups completely blocked PcAb binding to E2, suggesting that the epitopes bound by these MAbs form a single, immunodominant antigenic site. Only group I and III MAbs detected purified recombinant E2 bound to cells in binding assays. In contrast, group II MAbs neutralized the binding of E2 to cells. Both PcAb and MAbs were conformation dependent, with the exception of one group II MAb (M6). M6 bound to a five-amino-acid sequence on E2 if the peptide included four C-terminal or eight N-terminal residues, suggesting that the GBV-C E2 protein contains a single immunodominant antigenic site which includes a complex epitope that is involved in specific cellular binding.
Image Mapping Spectrometer (IMS) for Real Time Hyperspectral Fluorescence Microscopy (2010)

Image Mapping Spectrometer (IMS) is a snapshot hyperspectral imaging technique capable of providing full spectral information for entire fluorescent sample within a short 100-200 ms integration time. This paper presents an IMS system acquiring, analyzing and displaying datacube at 5-10 frame/sec rates. System design and imaging results for cells expressing GFP/YFP/CFP are discussed.
Experimental Evaluation of Kinetic and Thermodynamic Reaction Parameters of Colloidal Nanocrystals (2016)

The unique properties of colloidal semiconductor nanocrystals, or quantum dots, have attracted enormous interest in a wide range of applications, including energy, lighting, and biomedical fields. However, widespread implementation is hampered by the difficulty of developing large-scale and inexpensive synthesis routes, mainly due to our limited knowledge of formation reaction parameters. We report here a simple yet powerful method to experimentally determine critically important reaction parameters such as rate constants, activation barriers, equilibrium constants and reaction enthalpies. This method was applied to wurtzite cadmium selenide nanocrystals, yielding activation energies for growth and dissolution of 14 ± 6 kJ mol–1 and 27 ± 8 kJ mol–1, respectively, and a reaction enthalpy for nanocrystal growth of −15 ± 7 kJ mol–1. Moreover, the Gibbs free energy for growth was found to be negative at low temperatures, whereas dissolution becomes the spontaneous process above 150 °C.
PacketScore: A Statistics-Based Packet Filtering Scheme against Distributed Denial-of-Service Attacks (2006)

Distributed denial-of-service (DDoS) attacks are a critical threat to the Internet. This paper introduces a DDoS defense scheme that supports automated online attack characterizations and accurate attack packet discarding based on statistical processing. The key idea is to prioritize a packet based on a score which estimates its legitimacy given the attribute values it carries. Once the score of a packet is computed, this scheme performs score-based selective packet discarding where the dropping threshold is dynamically adjusted based on the score distribution of recent incoming packets and the current level of system overload. This paper describes the design and evaluation of automated attack characterizations, selective packet discarding, and an overload control process. Special considerations are made to ensure that the scheme is amenable to high-speed hardware implementation through scorebook generation and pipeline processing. A simulation study indicates that packetscore is very effective in blocking several different attack types under many different conditions.
Bioimpedance Sensor Array for Long-Term Monitoring of Wound Healing from Beneath the Primary Dressings and Controlled Formation of H2O2 Using Low-Intensity Direct Current (2019)

Chronic wounds impose a significant financial burden for the healthcare system. Currently, assessment and monitoring of hard-to-heal wounds are often based on visual means and measuring the size of the wound. The primary wound dressings must be removed before assessment can be done. We have developed a quasi-monopolar bioimpedance-measurement-based method and a measurement system to determine the status of wound healing. The objective of this study was to demonstrate that with an appropriate setup, long-term monitoring of wound healing from beneath the primary dressings is feasible. The developed multielectrode sensor array was applied on the wound area and left under the primary dressings for 142 h. The impedance of the wounds and the surrounding intact skin area was measured regularly during the study at 150 Hz, 300 Hz, 1 kHz, and 5 kHz frequencies. At the end of the follow-up period, the wound impedance had reached the impedance of the intact skin at the higher frequencies and increased significantly at the lowest frequencies. The measurement frequency affected the measurement sensitivity in wound monitoring. The skin impedance remained stable over the measurement period. The sensor array also enabled the administration of periodical low-intensity direct current (LIDC) stimulation in order to create an antimicrobial environment across the wound area via the controlled formation of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>).
Technical Issues In Low Rate Transform Coding (1988)

The transmission of video information through a narrow band channel requires a significant degree of image compression. In addition to the actual coding procedure, the frame rate is reduced, the spatial sample rate is lowered and the color components are further filtered. Via the review of a practical and flexible image compression configuration, the important technical aspects of videocoding is presented. The complexity of the currently developed system is discussed for the operation over a 64 kbit/sec communication channel. The specific and primary considerations include the following: After a reduction of temporal and spatial resolution, the luminance and color difference signals are divided in pixel blocks of 16 x 16 and 8 x 8, respectively. Then, they are passed on to a motion compensated DPCM coding system with a subsequent discrete cosine transform of the prediction error. The appropriate quantization is performed via several Huffman tables.
Purification to homogeneity and the N-terminal sequence of human leukotriene C4 synthase: a homodimeric glutathione S-transferase composed of 18-kDa subunits. (1993)

Human leukotriene C4 (LTC4) synthase was purified > 25,000-fold to homogeneity from the monocytic leukemia cell line THP-1. Beginning with taurocholate-solubilized microsomal membranes, LTC4 synthase was chromatographically resolved by (i) anion exchange, (ii) affinity chromatography (through a resin of biotinylated LTC2 immobilized on streptavidin-agarose), and then (iii) gel filtration. The final preparation contained only an 18-kDa polypeptide. The molecular mass of the pure polypeptide was consistent with an 18-kDa polypeptide from THP-1 cell membranes that was specifically photolabeled by an LTC4 photoaffinity probe, 125I-labeled azido-LTC4. On calibrated gel-filtration columns, purified LTC4 synthase activity eluted at a volume corresponding to 39.2 +/- 3.3 kDa (n = 12). The sequence of the N-terminal 35 amino acids was determined and found to be a unique sequence composed predominantly of hydrophobic amino acids and containing a consensus sequence for protein kinase C phosphorylation. We therefore conclude that human LTC4 synthase is a glutathione S-transferase composed of an 18-kDa polypeptide that is enzymatically active as a homodimer and may be phosphoregulated in vivo.
Efficient modeling of video-to-image conversion for QoS management in networked video service (2004)

Modality conversion (also called transmoding) currently emerges as an important issue in universal multimedia access. Intuitively, when content scaling cannot provide the acceptable QoS, modality conversion may be the good choice to maintain the quality. For this purpose, we need to answer a QoS-related question "at which resource constraint should the current modality be converted?" In our previous works, we have proposed the overlapped content value model that represents the relationship between quality and resource for different modalities, thus helping to find the conversion points between modalities. In this paper, we propose an efficient method to build the OCV model in the case of video-to-image conversion.
PSC motor improvement for direct drive clothes washer applications (1994)

Top load, vertical axis domestic washing machines using direct drive rapid reversing motors and simple speed reducers are becoming increasingly common in today's world market. Theoretical and practical advantages of these systems include a significant reduction in cost and hardware complexity. Additionally, performance flexibility in agitation and spin activity is increased. Cost effectiveness of this approach is contingent upon applying standard induction motors and avoiding variable voltage, variable frequency or DC power supply driven motors. Contemporary products achieve cost effectiveness by confining permanent split capacitor (PSC) direct drive application to smaller washing machine basket sizes and lighter clothes loads. In this class of washing machine, agitator size, stroke-rates and general energy transfer is quite different from typical American washing machines. This paper presents the study and development of an upgraded PSC prime mover for direct drive application to large load capacity washers. Modified rotor resistance motors similar in size, weight and cost to the lighter PSC systems have been developed for 14 to 18 pound American (high energy agitation) machines. The motor operates in synergy with a simple duty cycle modulation electronic control. The theory of development with supporting dynamometer and washing machine data is submitted in this text.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
In Vivo Expression and Immunological Studies of the 42-Kilodalton Carboxyl-Terminal Processing Fragment of<i>Plasmodium falciparum</i>Merozoite Surface Protein 1 in the Baculovirus-Silkworm System (2002)

ABSTRACT The 42-kDa carboxyl-terminal processing fragment of Plasmodium falciparum merozoite surface protein 1 (MSP-1 42 ) is an anti-erythrocytic stage malaria vaccine candidate. In this study, MSP-1 42 was expressed by using the Bombyx mori nuclear polyhedrosis virus-silkworm expression system, and the antigenicity and immmunogenicity of the recombinant protein, Bmp42, were evaluated. The average yield of Bmp42, as determined by a sandwich enzyme-linked immunosorbent assay (ELISA), was 379 μg/ml of infected silkworm hemolymph, which was >100-fold higher than the level attainable in cell culture medium. N-terminal amino acid sequencing revealed that Bmp42 was correctly processed in silkworm cells. Data from immunoblotting, as well as from the inhibition ELISA, suggested that the conformational B-cell epitopes of MSP-1 42 were recreated in Bmp42. Immunization of rabbits with Bmp42 in complete Freund's adjuvant generated high-titer antibody responses against the immunogen. Specificity analyses of the anti-Bmp42 antibodies using several recombinant MSP-1 19 proteins expressing variant and conserved B-cell epitopes suggested that the anti-Bmp42 antibodies recognized primarily conserved epitopes on MSP-1 19 . Furthermore, the anti-Bmp42 antibodies were highly effective in inhibiting the in vitro growth of parasites carrying homologous or heterologous MSP-1 42 . Our results demonstrated that the baculovirus-silkworm expression system could be employed to express biologically and immunologically active recombinant MSP-1 42 at elevated levels; thus, it is an attractive alternative for producing a protective MSP-1 42 vaccine for human use.
Characterization of a Sphingosine‐1‐phosphate Receptor Antagonist (2008)

Sphingosine 1‐phosphate (S1P) is an extracellular lipid mediator that acts via a set of G‐protein‐coupled receptors (S1P1 – S1P5) to influence angiogenesis, immune cell trafficking, cell migration, proliferation and survival. The S1P receptor agonist prodrug, FTY720, is an immunomodulator that is in late stage clinical trials for multiple sclerosis. In the course of making conformationally‐constrained FTY720 analogs, we discovered multiple S1P receptor type‐selective compounds including antagonists such as VPC03090‐P. This compound is a pro‐drug that is converted to the active compound, VPC03090‐P, by sphingosine kinase 2. The parent compound is orally available and long lived; the ratio of active to parent drug in mouse plasma at 24 hours post dosing is 20:1. VPC03090‐P behaves as a competitive antagonist at the S1P1, S1P3 and S1P5 receptors, shifting agonist concentration‐response curves in both GTP[γ‐ 35 S] binding and calcium mobilization assays by one log order or more when present at a concentration of 1 μM. Studies of the effect of this compound on lymphocyte trafficking and capillary permeability are ongoing. We anticipate that this unique tool will help elucidate the complex nature of S1P signaling. This research is supported by NIH grants R01 GM067958 and T32 GM007055.
DNA chip image processing via cellular neural networks (2002)

In this work, a new cellular neural network algorithm for DNA-chip automatic analysis is outlined. It allows to automatically classify in real-time fluorescence images from DNA microarray after the hybridization process. The paper introduces the main issues in DNA-chip technology and reports the key features of CNN application in this field, together with the description of a sample CNN algorithm and simulation results.
Terahertz quantum cascade lasers with double-resonant-phonon depopulation (2006)

We present two different terahertz quantum cascade laser (QCL) designs based on GaAs∕Al0.3Ga0.7As heterostructures that feature a depopulation mechanism of two longitudinal-optical phonon scattering events. This scheme is intended to improve high temperature operation by reducing thermal backfilling of the lower radiative state. The better of these two devices displays a threshold current density of 170A∕cm2 at 5K and lases up to 138K in pulsed mode and 105K in continuous-wave mode. However, contrary to expectation, we observed no improvement in temperature performance compared to single-resonant-phonon designs, which suggests that the thermal backfilling is not yet a limiting factor for high temperature terahertz QCL operation.
Control of Wood Dust from Disc Sanders (1991)

Abstract Association between nasal cancer and other health effects and occupations involving exposure to wood dust has been clearly established in the literature. This article reports on the research that has been conducted by scientists at the National Institute for Occupational Safety and Health (NIOSH) to reduce wood dust emissions from large-diameter disc sanders. An air jet stripper system was developed to be used in conjunction with existing local exhaust ventilation to reduce dust emissions. The system consists of a set of jets located inside the local exhaust hood. The jets are supplied with pressurized air. The control system, combined with currently existing controls, reduced wood dust emissions (area and breathing zone) by an average of 60 percent. Laboratory results were confirmed by field tests conducted at a wood furniture manufacturing plant. The control system does not interfere with the worker's activity, requires minimum maintenance, and is inexpensive to install and operate. This system also may extend the life of sanding discs by dislodging wood dust from the sanding surface.