gebhart/patrepeval huggingface dataset:
Identification of an Efficacy Switch Region in the Ghrelin Receptor Responsible for Interchange between Agonism and Inverse Agonism (2007)

The carboxyamidated wFwLL peptide was used as a core ligand to probe the structural basis for agonism versus inverse agonism in the constitutively active ghrelin receptor. In the ligand, an efficacy switch could be built at the N terminus, as exemplified by AwFwLL, which functioned as a high potency agonist, whereas KwFwLL was an equally high potency inverse agonist. The wFw-containing peptides, agonists as well as inverse agonists, were affected by receptor mutations covering the whole main ligand-binding pocket with key interaction sites being an aromatic cluster in transmembrane (TM)-VI and -VII and residues on the opposing face of TM-III. Gain-of-function in respect of either increased agonist or inverse agonist potency or swap between high potency versions of these properties was obtained by substitutions at a number of positions covering a broad area of the binding pocket on TM-III, -IV, and -V. However, in particular, space-generating substitutions at position III:04 shifted the efficacy of the ligands from inverse agonism toward agonism, whereas similar substitutions at position III: 08, one helical turn below, shifted the efficacy from agonism toward inverse agonism. It is suggested that the relative position of the ligand in the binding pocket between this "efficacy shift region" on TM-III and the opposing aromatic cluster on TM-VI and TM-VII leads either to agonism, i.e. in a superficial binding mode, or it leads to inverse agonism, i.e. in a more profound binding mode. This relationship between different binding modes and opposite efficacy is in accordance with the Global Toggle Switch model for 7TM receptor activation.
Error-robust video coding with channel-optimized trellis-coded quantization (2002)

This paper presents a low bit rate error-resilient channel-optimized coder for the transmission of video over the binary symmetric channel. The proposed coder uses a channel-optimized trellis-coded quantization (COTCQ) stage that is designed to optimize the video coding based on the channel characteristics. The resilience to channel errors is obtained by optimizing the coder performance only at the level of the source encoder, with no explicit use of channel coding for error protection. Additionally, due to the novel adaptive nature of the coder, the need for entropy coding and motion compensation is eliminated. Simulation results show that our coder provides outstanding quantitative and subjective coding performance for a wide variety of bit error rates, without the use of error concealment techniques.
Ca<sub>18.75</sub>Li<sub>10.5</sub>[Al<sub>39</sub>N<sub>55</sub>]:Eu<sup>2+</sup>—Supertetrahedron Phosphor for Solid-State Lighting (2016)

Highly efficient red-emitting luminescent materials deliver the foundation for next-generation illumination-grade white light-emitting diodes (LEDs). Recent studies demonstrate that the hardly explored class of nitridoaluminates comprises intriguing phosphor materials, e.g., Sr[LiAl3N4]:Eu2+ or Ca[LiAl3N4]:Eu2+. Here, we describe the novel material Ca18.75Li10.5[Al39N55]:Eu2+ with highly efficient narrow-band red emission (λem ≈ 647 nm, full width at half-maximum, fwhm ≈ 1280 cm–1). This compound features a rather uncommon crystal structure, comprising sphalerite-like T5 supertetrahedra that are composed of tetrahedral AlN4 units that are interconnected by additional AlN4 moieties. The network charge is compensated by Ca2+ and Li+ ions located between the supertetrahedra. The crystal structure was solved and refined from single-crystal and powder X-ray diffraction data in the cubic space group Fd3̅m (No. 227) with a = 22.415(3) Å and Z = 8. To verify the presence of Li, transmission electron microscopy (TEM) investigations including electron energy-loss spectroscopy (EELS) were performed. Based on the intriguing luminescence properties, we proclaim high potential for application in high-power phosphor-converted white LEDs.
Creep Mechanisms in High-Temperature In-Situ Composites (1999)

Abstract : The present work describes three year investigation of creep and toughening mechanisms in high strength, directionally solidified Nb silicides based in-situ composites. These composites consist of a Nb based silicides toughened with a Nb based solid solution. These composites have melting temperatures in excess of 1700 deg. C and densities less than 8 g/cc. The motivation for this study was to derive an understanding of a class of materials that possess a long term high temperature capability in excess of current nickel based superalloys. These studies have shown that room temperature fracture toughness can be increased to above 20 MPa (square root of m) in a range of complex silicides based composites with creep rupture behaviors superior to that of nickel based superalloys. The chemistries of the constituent phases, their volume fractions and their morphologies are critical features that control the balance of high and low temperature properties in this family of composites. During this program a thorough investigation of the dominant creep and toughening mechanisms that can be enhanced by independent modifications of the microstructure and properties of the metal and silicides phases has been completed. This investigation has examined the effect of volume fraction of silicides and strength of the metallic phase on the creep performance and fracture toughness of the composites. In-situ composite alloying concepts have been developed to provide a scheme for optimizing creep performance through control of the constituent phases. A series of phase equilibrium studies have also been completed. These include liquid solid and solid state phase equilibrium in the following systems: Nb-Ti-Si, Hf-Si, Nb-Hf-Si, and Hf-Th-Si. These investigations have been published in the open literature during the present contract.
Evaluation of Hydrogen Environment Embrittlement and Fatigue Properties of Stainless Steels in High Pressure Gaseous Hydrogen: Investigation of Materials Properties in High Pressure Gaseous Hydrogen—2 (2007)

Hydrogen environment embrittlement (HEE) susceptibility in high pressure gaseous hydrogen was investigated on 300 series austenitic stainless steels and A6061-T6 aluminum alloy. Tensile properties of these materials were evaluated by Slow Strain Rate Testing (SSRT) in gaseous hydrogen pressurized up to 90MPa (13053 psig) in the temperature range from −40 to 85 degrees C (−40 to 185 degrees F). HEE susceptibilities of austenitic stainless steels strongly depended upon the chemical compositions and testing temperatures. A6061-T6 aluminum alloy showed no degradation by hydrogen. Fatigue properties in high pressure gaseous hydrogen were evaluated by the external cyclic pressurization test using tubular specimens. The tubular specimen was filled with high pressure hydrogen gas, and the outside of the specimen was cyclically pressurized with water. Type 304 showed a decrease in the fatigue life in hydrogen gas, while as for type 316L and A6061-T6 the difference of the fatigue life between hydrogen and argon environments was small. HEE susceptibility of investigated materials was discussed based on the stability of an austenitic structure.
&lt;tex&gt;$rm MgB_2$&lt;/tex&gt;Tapes With Non-Magnetic Sheath: Effect of the Sintering Temperature on the Superconducting Properties (2005)

A nonmagnetic sheath, namely a Ni/Cr alloy (Ni80/Cr20), was used to fabricate MgB/sub 2/ tapes through the powder-in-tube (PIT) ex-situ technique. A series of samples sintered at different temperatures between 200/spl deg/C and 950/spl deg/C were prepared in order to correlate all the superconducting properties between them and with the sintering temperature. The possibility of using a nonmagnetic but at the same time hard sheath chemically compatible with the MgB/sub 2/ phase made possible a simpler interpretation of transport and magnetic measurements in magnetic field. With the chosen cold working parameters, we found that the amount of MgB/sub 2/ lattice strain was not sufficient to produce any enhancement of the upper critical field. The effect of the heat treatment temperature was on one hand to increase the grain connectivity but also to reduce the pinning properties of the superconductor.
Active Dna Demethylation of the Vertebrate Genomes by Dna Methyltransferases: Deaminase, Dehydroxymethylase or Demethylase? (2014)

Vertebrate DNA methyltransferases (DNMTs) have been thought to primarily function to covalently add a methyl group to the 5-position of cytosine. However, recent discovery of the DNA demethylation and dehydroxymethylation activities of DNMTs in vitro suggest new routes to complete the dynamic cycle of DNA methylation-demethylation of the vertebrate genomes. The in vitro reaction conditions suggest that vertebrate DNMTs can switch from DNA methylases to DNA dehydroxymethylases under oxidative stress and to DNA demethylases in the presence of calcium ion under nonreducing conditions. These environmental parameters provide clues regarding the choices in vivo of DNMT activities utilized in different physiological systems. In particular, the nature of these parameters suggest that the DNA demethylation and dehydroxymethylation activities of the vertebrate DNMTs play essential roles in multiple biological processes including early embryo development, regulation of neuronal plasticity, tumorigenesis and hormone-regulated transcription.
Thermogenic profiling using magnetic resonance imaging of dermal and other adipose tissues (2016)

Dermal white adipose tissue (dWAT) was recently recognized for its potential to modify whole body metabolism. Here, we show that dWAT can be quantified using a high-resolution, fat-specific magnetic resonance imaging (MRI) technique. Noninvasive MRI has been used to describe adipocyte depots for many years; the MRI technique we describe uses an advanced fat-specific method to measure the thickness of dWAT, together with the total volume of WAT and the relative activation/fat depletion of brown adipose tissues (BAT). Since skin-embedded adipocytes may provide natural insulation, they provide an important counterpoint to the activation of thermogenic brown and beige adipose tissues, whereby these distinct depots are functionally interrelated and require simultaneous assay. This method was validated using characterized mouse cohorts of a lipodystrophic, dWAT-deficient strain (syndecan-1 KO) and 2 obese models (diet-induced obese mice and genetically obese animals, ob/ob). Using a preliminary cohort of normal human subjects, we found the thickness of skin-associated fat varied 8-fold, from 0.13-1.10 cm; on average, this depot is calculated to weigh 8.8 kg.
Photoconductively controlled electro-optic laser modulation (1993)

We propose new configurations of electro-optic modulators that are controlled by photoconductive switches. Photoconductive switching speed and the use of optical feedback combine to provide the potential for flexible intracavity and extracavity modulation of low- and high-power beams at multigigahertz rates. Experimental results are presented in which a modulator of this type is used to Q switch and cavity dump a Nd:YAG laser, utilizing only a single external trigger. The same modulator is also used to Q switch, mode lock, and cavity dump the same laser. The modulator allows the laser to produces pulses with durations over the range of <80 ps to >20 ns.
Evaluation of an Ion‐Exchange Procedure for Removal of Hepatitis Type B Contamination from Human Gamma Globulin Products (1984)

Utilizing a unique human plasma sample that contained extremely high concentrations of hepatitis B surface antigen (HBsAg), we were able in the laboratory to rapidly screen the binding efficiency for HBsAg of various ion-exchange resins that can be used to purify gamma globulin product from human plasma. 'Nonrigid' resins like QAE-Sephadex and DEAE-Sephadex showed a high affinity for HBsAg by removing greater than 10(4) of applied challenge. Much lower binding was achieved by 'rigid' resins like DEAE-Sepharose CL-6B and DEAE-Spherodex. Also examined were the usefulness of certain auxiliary procedures, special filters and resins, that offer the potential to remove HBsAg. We failed to find any significant removal of the HBsAg, and in some cases large losses of the gamma globulin product occurred. While encouraged by our findings, certain precautions are discussed concerning the conversion from large-scale production of gamma globulin by the conventional alcohol method to one utilizing chromatographic techniques.
Method of preparing an electrochemical cell in uncharged state. [cathode of Li sulfide, transition metal, and electrolytic salt] (1977)

A secondary electrochemical cell is assembled in an uncharged state for the preparation of a lithium alloy--transition metal sulfide cell. The negative electrode includes a material such as aluminum or silicon for alloying with lithium as the cell is charged. The positive electrode is prepared by blending particulate lithium sulfide, transition metal powder, and electrolytic salt in solid phase. The mixture is simultaneously heated to a temperature in excess of the melting point of the electrolyte and pressed onto an electrically conductive substrate to form a plaque. The plaque is assembled as a positive electrode within the cell. During the first charge cycle lithium alloy is formed within the negative electrode and transition metal sulfide, such as iron sulfide, is produced within the positive electrode. 2 figures, 2 tables.
Rapid and sensitive detection of ovarian cancer biomarker using a portable single peak Raman detection method (2022)

Raman spectroscopy (RS) is a widely used non-destructive technique for biosensing applications because of its ability to detect unique 'fingerprint' spectra of biomolecules from the vibrational bands. To detect these weak fingerprint spectra, a complex detection system consisting of expensive detectors and optical components are needed. As a result, surface enhanced Raman spectroscopy (SERS) method were used to increase the Raman signal multifold beyond 10<sup>12</sup> times. However, complexity of the entire Raman detection system can be greatly reduced if a short wavelength region/unique single spectral band can distinctly identify the investigating analyte, thereby reducing the need of multiple optical components to capture the entire frequency range of Raman spectra. Here we propose the development of a rapid, single peak Raman technique for the detection of epithelial ovarian cancers (EOC)s through haptoglobin (Hp), a prognostic biomarker. Hp concentration in ovarian cyst fluid (OCF) can be detected and quantified using Raman spectroscopy-based in vitro diagnostic assay. The uniqueness of the Raman assay is that, only in the presence of the analyte Hp, the assay reagent undergoes a biochemical reaction that results in product formation. The unique Raman signature of the assay output falls within the wavenumber region 1500-1700 cm<sup>-1</sup> and can be detected using our single peak Raman system. The diagnostic performance of our Raman system had 100.0% sensitivity, 85.0% specificity, 100.0% negative predictive value and 84.2% positive predictive value when compared to gold standard paraffin histology in a proof-of-concept study on 36 clinical OCF samples. When compared to blood-based serum cancer antigen 125 (CA125) levels, the Raman system-based assay had higher diagnostic accuracy when compared to CA125, especially in early-stage EOCs.
Area-based interpolation for scaling of images from a CCD (2002)

We describe a method for scaling images which have been acquired with a charge coupled device (CCD) sensor. This method produces enlarged images which are sharper than those produced by bilinear interpolation, for comparable complexity. It is based on the observation that the sampling process of a CCD is not a point sampling process, but instead can be modelled as an averaging filter followed by sampling.
Two-photon flow cytometry (2005)

Flow cytometry is a powerful technique for obtaining quantitative information from fluorescence in cells. Quantization is achieved by assuring a high degree of uniformity in the optical excitation and detection, generally by using a highly controlled flow such as is obtained via hydrodynamic focusing. In this work, we demonstrate a two-beam, two-channel detection and two-photon excitation flow cytometry (T<sup>3</sup>FC) system that enables multi-dye analysis to be performed very simply, with greatly relaxed requirements on the fluid flow. Two-photon excitation using a femtosecond near-infrared (NIR) laser has the advantages that it enables simultaneous excitation of multiple dyes and achieves very high signal-to-noise ratio through simplified filtering and fluorescence background reduction. By matching the excitation volume to the size of a cell, single-cell detection is ensured. Labeling of cells by targeted nanoparticles with multiple fluorophores enables normalization of the fluorescence signal and thus ratiometric measurements under nonuniform excitation. Quantitative size measurements can also be done even under conditions of nonuniform flow via a two-beam layout. This innovative detection scheme not only considerably simplifies the fluid flow system and the excitation and collection optics, it opens the way to quantitative cytometry in simple and compact microfluidics systems, or <i>in vivo</i>.
The Challenges of Tau Imaging (2012)

In vivo imaging of tau pathology will provide new insights into tau deposition in the human brain, thus facilitating research into causes, diagnosis and treatment of major dementias, such as Alzheimer’s disease, or some variants of frontotemporal lobar degeneration, in which tau plays a role. Tau imaging poses several challenges, some related to the singularities of tau aggregation, and others related to radiotracer design. Several groups around the world are working on the development of imaging agents that will allow the in vivo assessment of tau deposition in aging and in neurodegeneration. Development of a tau imaging tracer will enable researchers to noninvasively examine the degree and extent of tau pathology in the brain, quantify changes in tau deposition over time, evaluate its relation to cognition and assess the efficacy of anti-tau therapy.
Synthesis of Chimerical Oligonucleotides Containing Internucleosidic Phosphodiester and<i>S</i>-Pivaloyl Mercaptoethyl Phosphotriester Linkages (1999)

Abstract Novel oligonucleotide analogs that bear phosphodiester and bioreversible S-pivaloyl 2-mercaptoethyl (SPME) phosphate triester internucleosidic linkages and their thioate analogs are described. Their synthesis involves new methodology for the deprotection of base-labile oligonucleotides.
Intimin from enteropathogenic Escherichia coli mediates remodelling of the eukaryotic cell surface (2000)

Adhesion to cultured epithelial cells by enteropathogenic Escherichia coli (EPEC) is associated with extensive rearrangement of the host cell cytoskeleton. Evidence has been presented that EPEC adhesion is associated with activation of signal transduction pathways leading to production of a characteristic histopathological feature known as the attaching and effacing (A/E) lesion. A/E lesion formation requires intimin, an EPEC adhesion molecule and several EPEC secreted proteins (EspA, B, D and Tir) involved in cell signalling and protein translocation. In this study it is shown that HEp-2 cells respond during the early stages of infection with two wild-type EPEC strains (B171 and E2348/69) by producing microvillus-like processes (MLP) at the site of initial bacterial adherence. Intimin appears to play a key role in MLP elongation. At later stages of infection with these wild-type EPEC strains, when A/E lesions have formed, the MLP were reduced in number and length to appear as at time zero, and the cell surface in the vicinity of bacterial clusters appeared unaffected. In contrast, infection with EspA- or EspB-negative, but intimin-positive, EPEC strains (UMD872 and UMD864, respectively) resulted in enhanced MLP proliferation and formation of 'cage-like' structures engulfing the bacteria. Inoculating HEp-2 cells with intimin-coated latex spheres induced similar 'cage-like' structures. Caco-2 cells did not show intimin-induced microvillus elongation in response to EPEC infection, although microvillus effacement and reduction in number occurred. Similar phenomena appeared on B171 and E2348/69 infection of paediatric intestine using in vitro organ culture, i.e. elongated microvilli were seen in association with small colonies and at the periphery of large localized colonies, along with evidence of microvillus breakdown and debris in the colony centre. These results show that intimin activates signal transduction pathways involved in the remodelling of the eukaryotic cell surface, probably via binding to a receptor encoded by the host cell.
Coverage of MC/JD-CDMA based macrocellular radiosystems (1997)

A method for analysing the coverage of cellular radio systems is explained and applied to multicarrier joint detection code division multiple access (MC/JD-CDMA) . The method comprises a link analysis which explicitly considers a quality of service criterion combined with a requirement on the area probability of service.
Video and image watermark synchronization (2005)

Digital watermarking is the practice of inserting a signal, known as the watermark, into an original signal in an imperceptible manner. The watermark encodes or represents information that can protect the watermarked signal, typically identifying the owner (source) or the intended recipient (destination) of the signal. The embedded watermark may be detected by using a watermark detector, which enables an application to react to the presence (or absence) of the watermark in a signal. However, the watermarked signal may be processed, or attacked, prior to watermark detection. Attacks may remove the embedded watermark or make the watermark more difficult to detect. One type of attack that has received considerable attention is synchronization attacks. A synchronization attack confuses the watermark detector by re-positioning the embedded watermark. Most watermark detectors will fail to detect the water mark embedded in the attacked signal unless the position of the watermark can be identified. This is a significant vulnerability in robust watermark detection. The process of identifying the position of the watermark is known as watermark detector synchronization. A new framework is developed for temporal synchronization in blind symmetric video watermarking. Embedding and detection models are proposed that encompass the behavior of many video watermarking techniques. These models demonstrate that synchronization is challenging when the watermark lacks redundancy, but also that efficient synchronization can be achieved by designing the watermark with temporal redundancy. The temporal synchronization models are adapted to spatial synchronization in still image watermarks. For spatial synchronization, redundancy is obtained by constructing a watermark which induces a pattern in the auto-correlation. Experimental results support the theoretical foundations for both temporal and spatial synchronization. In addition, earlier exploration in watermarking led to the development of a semi-fragile watermarking technique for image authentication. The semi-fragile technique is capable of detecting significant alterations to the watermarked image, but is tolerant to lossy JPEG compression and other, more subtle alterations. This earlier work is not related to watermark synchronization.