gebhart/patrepeval huggingface dataset:
Pyrolysis of Trifluoromethane to Produce Hexafluoropropylene (2002)

Pyrolysis of a mixture of trifluoromethane (CHF3, R23) and tetrafluoroethylene (CF2CF2, TFE) to produce hexafluoropropylene (CF3CFCF2, HFP) was investigated by kinetic modeling and pyrolysis experiments. Product distributions from the pyrolysis of R23/TFE mixtures were estimated by a computer simulation using kinetic rate constants of individual reaction steps proposed in the literature and were compared with those obtained from pyrolysis experiments in a bench-scale tubular reactor. In addition, pyrolysis of the R23/TFE mixture in a mini-pilot-plant-scale reactor was investigated for the purpose of industrial application under the conditions of reaction temperatures of 700−1000 °C, contact times of 0.01−14 s, and R23/TFE molar ratios of 0.1−5. HFP was mainly produced, along with a small amount of byproducts such as perfluoroisobutylene [PFiB, (CF3)2CCF2 ], CF3CCCF3, C2F3H, CF3CHCF2, and CF3CF2CFCF2. By mixing R23 and TFE in the feed or by recycling the unreacted R23 and TFE to the feed of fresh R23, the reaction temperature could be controlled by carefully utilizing the heat balance between the endothermic pyrolysis of R23 and the exothermic dimerization of TFE. It was found that the simultaneous pyrolysis of a mixture of R23 and TFE with an appropriate molar ratio gave a higher yield of HFP and a lower selectivity of PFiB, a very harmful byproduct, than the pyrolysis of R23 alone. In addition, the pyrolysis of the mixture of R23 and TFE produced less carbon powder and also required less energy to be externally supplied than the pyrolysis of R23.
A Miniature Fiber Optic pH Sensor for Physiological Use (1980)

A flexible 0.4-mm-dia pH probe potentially suitable for physiological use has been developed. It is based on the concept of utilizing two single plastic fiber optic strands to illuminate and remotely sense the color change of a dye indicator contained within an acutely implanted sealed cellulosic hollow fiber permeable to hydrogen ions. A supporting electronic module provides tungsten filament illumination, light sensing with a photodiode/operational amplifier, analog and digital circuitry to provide appropriate signal averaging and processing, and a mechanical assembly to enable the optical density measurements to be made both at 560 nm and, for normalization purposes, in the red. Over the physiological pH range from 7.0 to 7.4, the fiber optic probe agrees with a standard glass pH electrode to within 0.01 pH units in buffer solutions, to within 0.017 pH units in heparinized dog blood in vitro, and it has performed successfully while implanted in the jugular vein of a sheep.
Challenges in High Performance Computing for Reservoir Simulation (2012)

Abstract High resolution reservoir modeling is necessary to analyze complex flow phenomena in reservoirs. As more powerful computing platforms become available, reservoir simulation engineers are building larger and higher resolution reservoir models to study giant fields. Large number of simulations is necessary to validate the model and to lower uncertainty in prediction results. It is a challenge to accurately model complex processes in the reservoir and also efficiently solve high resolution giant reservoir models on rapidly evolving hardware and software platforms. There are many challenges to get high performance in reservoir simulations on constantly evolving computing platforms. There are constraints which limit performance of large scale reservoir simulation. In this study, we review some of these constraints and show their effects on practical reservoir simulation. We review emerging computing platforms and highlight opportunities and challenges for reservoir simulation on those platforms. It is anticipated that management of data locality by the simulator will become very important on emerging computing platforms and there will be needs to manage locality to achieve good performance. Heterogeneity in the computing platform will make it difficult to get good performance without adoption of a hybrid parallelization style in the simulator. In this study, we analyze many benchmark results to illustrate challenges in high performance computations of reservoir simulation on current and emerging computing platforms.
Quantum well infrared photodetectors for long wavelength infrared imaging applications (2002)

Long wavelength Quantum Well Infrared (QWIP) cameras developed at the Jet Laboratory demonstrate the potential of GaAs/Al/sub x/Ga/sub 1-x/As QWIP technology for highly sensitive, low power, low cost, and highly uniform large format (focal plane array (FPA)) imaging systems. These cameras utilize FPAs as large as 640/spl times/486 based on optimized GaAs/AlGaAs multiquantum-well (MQW) structures coupled with random or two dimensional periodic grating reflectors. Reported uniformities of these FPAs are better than 99.95% after two point correction has been reported. Other advantages of GaAs/AlGaAs based QWIPs are higher yield, durability, radiation hardness, and no 1/f noise till 30 mHz. In addition, QWIPs offer greater flexibility than usual extrinsically doped semiconductor IR detectors because the wavelength of the peak response and cutoff can be continuously tailored by varying layer thickness (wellwidth,) barrier composition (barrier height), and carrier density (well doping density). The GaAs/Al/sub x/Ga/sub 1-x/As material system allows the quantum well parameters to be varied over a range wide enough to enable light detection at any wavelength range between, 6-20 /spl mu/m. The spectral band width of these detectors can be tuned from narrow (/spl Delta//spl lambda///spl lambda//spl sim/10%) to wide (/spl Delta//spl lambda///spl lambda/ /spl sim/40%), allowing various applications. Also, QWIP device parameters can be optimized to achieve extremely high performance at lower operating temperatures (/spl sim/40 K) for low background, long-wavelength, infrared applications in the strategic arena as well as in astronomy.
A method for calibrating the relative gamma-ray light yield of plastic scintillators (2017)

Currently we are investigating the inclusion of organotin compounds in new polystyrene scintillator materials to improve full gamma-ray energy sensitivity. Accurate calibration of the relative light yield from the newly developed scintillators is crucial to assess merits of compounds and chemical processes used in the scintillators' development. The full energy gamma-ray peak in a measured gamma-ray spectrum is commonly used in calibrating the relative light yield. However, the Compton continuum in the newly developed plastic scintillators is measured with much better efficiency and statistics and is found to be the best spectral feature that can be exploited for expeditious calibration of the relative light yield. In this study, we present a spectral gain matching of measured and simulated spectra, using a spectrum rebinning technique, to determine the Compton edge in a measured Compton continuum for accurate relative light yield calibration. The Compton edges determined using this technique were found to be within 1.2% of their theoretical estimates.
Mixed-Phase Synthesis of Glycopeptides Using a <i>N</i>-Peptidyl-2,4-dinitrobenzenesulfonamide–Thioacid Ligation Strategy (2011)

A strategy for the solid phase peptide synthesis (SPPS) and coupling of N-peptidyl and N-glycopeptidyl 2,4-dinitrobenzenesulfonamides (dNBS) with C-terminal peptidyl thioacids has been developed. The resulting N-dDNBS peptides were coupled to generate longer peptides. Ligation reactions were complete within 15 to 20 min.
Emissive chart for imager calibration (2004)

Each and every color imaging device should be custom calibrated both to enhance image processing algorithms and to produce pleasing and faithful images of the captured scenes or medias. Custom calibrations, however, are usually not performed because calibration instruments are either too slow to be used on the manufacturing line or the instruments lack the necessary accuracy. We have developed a calibration instrument that enables both fast and accurate imager calibrations. The instrument is based on emissive narrow-band light sources—light emitting diodes—arranged in a grid pattern or chart configuration. We refer to the instrument as the emissive calibration chart or the EC chart. We compare the emissive calibration chart to other calibration instruments, which include reflective charts, like the Macbeth ColorChecker or DC charts, and monochromators. The results demonstrate that custom calibrations of each and every imager could be accurately determined on the manufacturing line using the emissive calibration chart.
Practical Design of an Octave-band Stacked Patch Antenna Phased Array (2019)

MIT Lincoln Laboratory is developing a planar ultra-wideband phased array antenna. The radiator is required to operate over an octave of bandwidth and provide up to 55° of scanning in elevation and azimuth with dual polarization capability. Although these requirements are easily met using state of the art designs such as a PUMA or Vivaldi array, the design requires co-located phase centers for the unit cell. A detailed description of the probe-fed stacked patch radiator design will be reviewed and results discussed. Measurements will be presented for the prototype that was fabricated.
Three-Dimensional Moments of Molecular Property Fields (2000)

Descriptors that capture certain three-dimensional molecular features and do not require molecular superposition or alignment for the assignment of molecular similarity have recently been proposed and investigated. Among these, moments of molecular features have been utilized in the QSAR of several molecular series. The present work examines certain formal aspects of the use of moment expansions for which the zero-order moment of a property field is nonvanishing. The first-order term of such moment expansion is then dependent upon the origin of expansion, and it is pointed out that expansion about the molecular centroid is descriptive of first-order differences about the property-field mean. For a hydrophobic property field, this first-order term is just the Eisenberg hydrophobic moment. Second-order moments about the centroid can be written as components of the WHIM covariant matrix. Moment expansions are also performed about the property-field center in analogy with expansions about the center of mass. For such expansion, a set of descriptors consisting of moments of the molecular density and of a molecular hydrophobic property field as well as of related quantities are used in a QSAR of the binding of 74 polyhalogenated aromatic molecules to the Ah cystolic receptor. This QSAR has been named CoMMA2 to distinguish it from CoMMA, for which the zero-order moment of the expansion vanishes.
Abnormal Aggregation Accompanies Abnormal Platelet Ca2+ Handling in Arterial Thrombosis (1987)

The resting levels of cytoplasmic Ca2+ (measured by Quin 2 fluorescence) and dense tubular Ca2+ (measured by chlorotetracycline, CTC, fluorescence) are shown to be higher in platelets from patients with arterial thrombosis than from normal donors. Turbidimetric studies of aggregation of diluted platelet-rich plasma (PRP) at 135 microM Ca2+ showed increased rates of aggregation for patients relative to normal controls. For ADP-stimulated aggregation, increased maximal rates (Vmax) and decreased doses for half-maximal rates were observed. With collagen-stimulated aggregation, patient samples showed only decreased ED50 values relative to normal controls. The changes in these values are linearly correlated with the elevation of resting dense tubular Ca2+ level determined by the calcium-CTC test carried out at 2 mM external Ca2+. For ADP-stimulated aggregation this relationship can be mimicked by pre-incubating normal platelets with subcritical concentrations of the Ca2+ ionophore A23187. These results suggest that elevated cytoplasmic and dense tubular Ca2+ in the "resting state" is a major factor in arterial thrombosis, rendering the platelet more sensitive to the stimulation by physiologic agents.
Inhibition of human megakaryocytopoiesis in vitro by platelet factor 4 (PF4) and a synthetic COOH-terminal PF4 peptide. (1989)

We report that highly purified human platelet factor 4 (PF4) inhibits human megakaryocytopoiesis in vitro. At greater than or equal to 25 micrograms/ml, PF4 inhibited megakaryocyte colony formation approximately 80% in unstimulated cultures, and approximately 58% in cultures containing recombinant human IL 3 and granulocyte-macrophage colony-stimulating factor. Because PF4 (25 micrograms/ml) had no effect on either myeloid or erythroid colony formation lineage specificity of this effect was suggested. A synthetic COOH-terminal PF4 peptide of 24, but not 13 residues, also inhibited megakaryocyte colony formation, whereas a synthetic 18-residue beta-thromboglobulin (beta-TG) peptide and native beta-TG had no such effect when assayed at similar concentrations. The mechanism of PF4-mediated inhibition was investigated. First, we enumerated total cell number, and examined cell maturation in control colonies (n = 200) and colonies (n = 100) that arose in PF4-containing cultures. Total cells per colony did not differ dramatically in the two groups (6.1 +/- 3.0 vs. 4.2 +/- 1.6, respectively), but the numbers of mature large cells per colony was significantly decreased in the presence of PF4 when compared with controls (1.6 +/- 1.5 vs. 3.9 +/- 2.3; P less than 0.001). Second, by using the human leukemia cell line HEL as a model for primitive megakaryocytic cells, we studied the effect of PF4 on cell doubling time, on the expression of both growth-regulated (H3, p53, c-myc,and c-myb), and non-growth-regulated (beta 2-microglobulin) genes. At high concentrations of native PF4 (50 micrograms/ml), no effect on cell doubling time, or H3 or p53 expression was discerned. In contrast, c-myc and c-myb were both upregulated. These results suggested the PF4 inhibited colony formation by impeding cell maturation, as opposed to cell proliferation, perhaps by inducing expression of c-myc and c-myb. The ability of PF4 to inhibit a normal cell maturation function was then tested. Megakaryocytes were incubated in synthetic PF4, or beta-TG peptides for 18 h and effect on Factor V steady-state mRNA levels was determined in 600 individual cells by in situ hybridization. beta-TG peptide had no effect on FV mRNA levels, whereas a approximately 60% decrease in expression of Factor V mRNA was found in megakaryocytes exposed to greater than or equal 100 ng/ml synthetic COOH-terminal PF4 peptide. Accordingly, PF4 modulates megakaryocyte maturation in vitro, and may function as a negative autocrine regulator of human megakaryocytopoiesis.
In vivo regeneration of interspecies chimeric kidneys using a nephron progenitor cell replacement system (2019)

Kidney regeneration is expected to be a new alternative treatment to the currently limited treatments for chronic kidney disease. By transplanting exogeneous nephron progenitor cells (NPCs) into the metanephric mesenchyme of a xenogeneic foetus, we aimed to regenerate neo-kidneys that originate from transplanted NPCs. Previously, we generated a transgenic mouse model enabling drug-induced ablation of NPCs (the Six2-iDTR mouse). We demonstrated that eliminating existing native host NPCs allowed their 100% replacement with donor mouse or rat NPCs, which could generate neo-nephrons on a culture dish. To apply this method to humans in the future, we examined the possibility of the in vivo regeneration of nephrons between different species via NPC replacement. We injected NPCs-containing rat renal progenitor cells and diphtheria toxin below the renal capsule of E13.5 metanephroi (MNs) of Six2-iDTR mice; the injected MNs were then transplanted into recipient rats treated with immunosuppressants. Consequently, we successfully regenerated rat/mouse chimeric kidneys in recipient rats receiving the optimal immunosuppressive therapy. We revealed a functional connection between the neo-glomeruli and host vessels and proper neo-glomeruli filtration. In conclusion, we successfully regenerated interspecies kidneys in vivo that acquired a vascular system. This novel strategy may represent an effective method for human kidney regeneration.
GOLD AND ALLOY NANOPARTICLE CATALYSTS IN FUEL CELL REACTIONS (2004)

Gold-based nanoparticles (1-5 nm) have recently emerged as highly active catalysts for many important catalytic reactions [1]. A major factor for their catalytic activity is related to the sizeand composition-dependent properties of nanoparticles. We have investigated the preparation and catalytic properties of gold-based alloy nanoparticles supported on carbon materials [2,3]. One example involves the preparation of monolayer-capped AuPt nanoparticles for electrocatalytic oxidation of methanol and reduction of oxygen. To delineate the size and composition correlation of the catalytic properties, we employed an array of surface analytical techniques to probe the structural and morphological evolution and reconstitution of the nanoparticles upon catalytic activation. These techniques include; atomic force microscopy (AFM), transmission electron microscopy (TEM), surface infrared reflection spectroscopy (IRS), X-ray photoelectron spectroscopy (XPS), and thermogravimetic analysis (TGA) [3-5]. The combined results of these characterizations have provided insights into the viability of tailoring the nanostructured catalysts in terms of size and composition.
Inhibition of Angiogenesis by Cleaved High Molecular Weight Kininogen (HKa) and HKa Domain 5 (2005)

High molecular weight kininogen (HK) is an abundant, multi-domain plasma protein that circulates in plasma primarily in its single chain form. Proteolytic cleavage of HK by plasma kallikrein releases the vasoactive nanopeptide bradykinin (BK), and converts HK into two-chain HK (HKa). BK appears to have pro-angiogenic activity, most likely mediated through binding to B1 and B2 receptors on endothelial cells. Conversely, HKa and its domain 5, but not (single chain) HK, have potent anti-angiogenic activity comparable to other endogenous angiogenesis inhibitors. The mechanism by which HKa exerts its anti-angiogenic activity remains controversial, but appears to involve binding to cell surface tropomyosin and induction of apoptosis of proliferating endothelial cells. A role for tropomyosin in mediating the anti-angiogenic signals of other anti-angiogenic proteins such as endostatin and histidine-proline-rich glycoprotein (HPRG) has also been reported. Here we review the physiological importance of high molecular weight kininogen in angiogenesis, with emphasis on the mechanism(s) by which this activity is mediated.
Pharmacokinetic and pharmacodynamic studies of a novel antitumor wortmannin analogue inhibitor of phosphatidylinositol-3-kinase (2004)

4752 Phosphatidylinositol-3-kinase (PI-3-K) is activated by a wide range of growth factor receptors and oncogenic protein-tyrosine kinases as well as by p21Ras. Constitutive activation of PI-3-K occurs in human small cell lung cancer and in approximately 40% of human ovarian, head and neck, urinary tract and cervical cancers. The major mechanism for the oncogenic activity of PI-3-K is its role in survival signaling to prevent apoptosis through the down stream activation of PH domain-containing proteins such as Akt. PI-3-K signaling activity is attenuated by PTEN, a tumor suppressor that is lost in many human cancers. Thus, PI-3-K is a drug target to inhibit cancer cell survival signaling pathway and to compensate for lost PTEN. A PI-3-K inhibitor would be predicted to have antitumor activity and to potentiate the sensitivity of cancer cells to radiation and chemotherapy. We have previously reported that the irreversible PI-3-K inhibitor wortmannin has oral antitumor activity in animal models. Wortmannin is a highly reactive compound that cannot be detected in plasma after parenteral administration and causes toxicity, primarily to the liver. From screen of over 300 wortmannin analogues we have identified a wortmannin analogue that retains potent PI-3-K inhibitory activity with an IC50 of 10 nM against immunoprecipitated enzyme and an IC50 of 25 nM in EGF stimulated HT-29 colon cancer cells measured by phospho-Akt inhibition. DJM-166 is less reactive than wortmannin and has considerably decreased liver toxicity in mice. DJM-166 shows antitumor activity against a number of human tumor xenografts including established (100 mm3) OvCar-3 ovarian cancer that shows over expression of PI-3-K (DJM-166 8 mg/kg ip QD x 9, log10 cell kill= 1.2) and additive activity with radiation (DJM-166 12.5 mg/kg QD x 5, 2 hr before 1 Gy radiation, log10 cell kill from 0.6 to 1.6). DJM-166, has been subjected to pharmacokinetic (PK) and pharmacodynamic (PD) studies in mice. A HPLC/mass spectrometric assay was developed for PK studies DJM-166 in plasma. Following iv administration to mice at 10 mg/kg the peak plasma concentration was 1.9 μg/ml and half life 19.5 min. Oral administration of the same dose of DJM-166 gave barely detectable plasma DJM-166 concentrations around 0.1 μg/ml. PD studies showed that a single iv dose of DJM-166 at 10 mg/kg inhibited HT-29 tumor xenograft phopsho-Akt a maximum of 67.5 ± 5.0 % at 10 hr and recovery by 48 hr. The same dose of DJM-166 administered orally gave a maximum inhibition of 78.3 ± 1.8 % at 24 hr and remained at 69.0 ± 9.0 % at 48 hr. There was also inhibition of phospho-GSK-3, a down stream target of Akt. The work shows that DJM-166 causes pronounced inhibition of tumor xeonograft PI-3-K signaling and has antitumor activity. DJM-166 appears to be metabolized to active metabolite(s) especially after oral administration. Supported by CA52995 and CA90821
Polymers And Riblets Reduce Hydrodynamic Skin Friction (1991)

Polymers injected into riblet grooves dramatically reduce polymer flow rate required for drag reduction. Polymer solution injected into valleys of grooves through array of holes or slots angled downstream to keep injected streams within grooves. Injection repeated some distance downstream because volumes of grooves finite and polymer becomes depleted as slowly pulled from groove by turbulence. Potentially useful for oil tankers as means of markedly reducing cost of fuel and used extensively on submarines, other ships, and other marine vehicles.
Memory-Based Forecasting for Weather Image Patterns (2000)

A novel method and a framework called Memory-Based Forecasting are proposed to forecast complex and timevarying natural patterns with the goal of supporting experts’ decision making. This paper targets the local precipitation phenomena captured as echo patterns in weather radar images, and aims to realize a tool that supports weather forecasters. In our framework, past image patterns similar to the present pattern are retrieved from a large set held in an image database, and the forecast image is produced by using the patterns that follow the retrieved patterns; it is analogous to human forecasters who imagine the future patterns based on their past experience. Appearance-based image features and temporal texture features are introduced to characterize the non-rigid complex echo patterns found in such radar images. The dissimilarity between two image sequences is defined as the normalized distance between paths of feature points in eigenspaces of the image features to retrieve similar past sequences. Forecast images are then constructed from a future point in the feature spaces, which is estimated by a nonlinear prediction scheme. Statistical experiments using weather radar images verify the effectiveness of our method and framework especially for drastically changing patterns.