gebhart/patrepeval huggingface dataset:
Neutron spectrometry using CR-39 track etch detectors (2006)

Track-size distributions were measured for chemically etched CR-39 foils exposed to monoenergetic neutrons with energies ranging from 0.144 to 19 MeV and to various broad-spectrum neutron sources including spontaneous fission neutrons from (238)Pu. These tracks are due to energetic charged particles resulting from interactions of the neutrons with the CR-39. The tracks are visible with an optical microscope after chemical etching and vary in size and configuration depending on the particle, energy and angle of incidence. The foils were analysed using an automatic analysis system that scans the foils, identifies valid tracks and records the track-size parameters. The track-size distributions vary with neutron energy for the monoenergetic sources and with the hardness of the broad-spectrum sources. The distribution from the (238)Pu fission source is readily distinguishable from the other sources measured and from distributions owing to the background.
High order synchronization, transitions, and competition among Arnold tongues in a continuous phase oscillator under harmonic forcing (2007)

We consider a rotator whose equation of motion for the angle $\theta$ consists of the zeroth and first Fourier modes. Numerical analysis based on the trailing of saddle-node bifurcations is used to locate the n:1 Arnold tongues where synchronization occurs. Several of them are wide enough for high-order synchronization to be seen in passive observations. By sweeping the system parameters within a certain range, we find that the stronger the dependence of $\dot\theta$ on $\theta$, the wider the regions of synchronization. Use of a synchronization index reveals a vast number of very narrow n:m Arnold tongues. A competition phenomenon among the tongues is observed, in that they push and squeeze one another: as some tongues widen, others narrow. Two mechanisms for transitions between different n:m synchronization states are considered: slow variation of the driving frequency, and the influence of low-frequency noise on the rotator.
Resonance Raman spectroscopic studies on the conducting state of polyvinylcarbazole and its model compounds (1998)

The conductivity in polyvinylcarbazole (PCVz), a well known photoconducting polymer, has been attributed to the migration of the cation radicals along the chain. In this paper, chemically generated monomer and dimer radical cations of the carbazolyl group and the conducting form of PVCz have been investigated by resonance Raman (RR) spectroscopy. Vibrational assignments are presented for the observed frequencies by comparison with similar compounds and also by density functional theoretical calculations. The structure of the monomer and dimer radical cations have been inferred from the RR spectra. It has been observed that Raman bands of the radical cation of PVCz in which the charge is localized on the dimer, undergo a downshift compared to that of N-ethylcarbazole (NEC) dimer radical cation. This shift has been tentatively attributed to the interaction of the PVCz dimer radical cation with the neutral carbazole which may be facilitated by the conformational rearrangement required for the exchange of charge with neutral carbazole. © 1998 John Wiley & Sons, Ltd.
Development of ZnO thin films for SAW devices by the ultrasonic spray pyrolysis technique (2002)

ZnO thin films for use in SAW filters have been prepared on SiO/sub 2//Si substrates by the ultrasonic spray pyrolysis technique. Thickness of the films has been determined through a SAW propagation simulation on the substrate as 8000 /spl Aring/ for the ZnO and 5000 /spl Aring/ for the SiO/sub 2/ at which the coupling factor and the Rayleigh wave velocity are 0.9% and 2900 m/sec, respectively. For use in SAW filters, the ZnO thin film should have high resistivity and strong piezoelectric activity, i.e., good c-axis orientation. For simultaneous achievement of the two desired properties, we have rigorously investigated the effects of various deposition parameters through experiments. The optimal deposition conditions have been determined as a substrate temperature of 430/spl deg/C, a zinc acetate solution of 0.05 M doped with 20 atomic percent of LiCl, a flow rate of 2.5 ml/min., reactor pressure of 3 Torr, and annealing and cooling down in oxygen environment. Deposited ZnO thin films show good thickness uniformity over a 4" wafer, have c-axis orientation ratio over 99%, and have resistivity of the order of 10/sup 9/ ohm/spl middot/m.
Pb-doped bisrcacuo superconducting thin films grown by halide-CVD (1993)

Abstract Effects of Pb-doping in superconducting BiSrCaCuO films have been experimentally studied by using a halide-CVD from BiCl3, PbCl2, SrI2, CaI2 and CuI powders. The Pb/(Bi + Pb) ratio in oxide films was successfully controlled by the temperature of PbCl2. The Pb-doping enhanced the high-Tc phase to increase the critical temperature of the superconducting transition. The optimal Pb concentration was determined to be about 0.15 for the 2223 high-Tc phase.
Sputter deposition of highly 〈100+001〉-textured tetragonal barium titanate on unheated silica using a neon discharge (1992)

The sputter deposition of highly 〈100+001〉-textured tetragonal BaTiO3 on unheated substrates using a pressed powder BaTiO3 target and a radio frequency-excited Ne discharge is reported. For comparison, amorphous BaTiO3 was also produced, using an Ar discharge operated at the same value of all other independent process parameters. In situ discharge diagnostics using optical emission spectrometry was used to study the plasma volume. Data show that there was atomic Ti but no atomic Ba in the Ne discharge used to produce t-BaTiO3. However, both atomic Ba and Ti were identified in the Ar discharge used to produce a-BaTiO3. A probable source of free Ba atoms in the plasma is the reduction of BaTiO3 at the target surface due to the sputtering action of Ar+ ions. By comparison with other sputter-deposited metal oxide systems, the effect on film crystallinity of atomic metal versus molecular metal oxide flux incident on the substrate is discussed.
The Sulfonic Acids Derived from Pyridine and 2,6-Lutidine and the Corresponding N-Oxides<sup>1</sup> (1962)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Sulfonic Acids Derived from Pyridine and 2,6-Lutidine and the Corresponding N-Oxides1RUSSELL F. EVANS and HERBERT C. BROWNCite this: J. Org. Chem. 1962, 27, 4, 1329–1336Publication Date (Print):April 1, 1962Publication History Published online1 May 2002Published inissue 1 April 1962https://pubs.acs.org/doi/10.1021/jo01051a049https://doi.org/10.1021/jo01051a049research-articleACS PublicationsRequest reuse permissionsArticle Views892Altmetric-Citations27LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Mechanistic Studies of (Porphinato)Iron-Catalyzed Isobutane Oxidation. Comparative Studies of Three Classes of Electron-Deficient Porphyrin Catalysts (2000)

We report herein a comprehensive study of (porphinato)iron [PFe]-catalyzed isobutane oxidation in which molecular oxygen is utilized as the sole oxidant; these catalytic reactions were carried out and monitored in both autoclave reactors and sapphire NMR tubes. In situ 19F and 13C NMR experiments, coupled with GC analyses and optical spectra obtained from the autoclave reactions have enabled the identification of the predominant porphyrinic species present during PFe-catalyzed oxidation of isobutane. Electron-deficient PFe catalysts based on 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin [(C6F5)4PH2], 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(pentafluorophenyl) porphyrin [Br8(C6F5)4PH2], and 5,10,15,20-tetrakis(heptafluoropropyl) porphyrin [(C3F7)4PH2] macrocycles were examined. The nature and distribution of hydrocarbon oxidation products show that an autoxidation reaction pathway dominates the reaction kinetics, consistent with a radical chain process. For each catalytic system examined, PFeII species were shown not to be stable under moderate O2 pressure at 80 degrees C; in every case, the PFeII catalyst precursor was converted quantitatively to high-spin PFeIII complexes prior to the observation of any hydrocarbon oxidation products. Once catalytic isobutane oxidation is initiated, all reactions are marked by concomitant decomposition of the porphyrin-based catalyst. In situ 17O NMR spectroscopic studies confirm the incorporation of 17O from labeled water into the oxidation products, implicating the involvement of PFe-OH in the catalytic cycle. Importantly, Br8(C6F5)4PFe-based catalysts, which lack macrocycle C-H bonds, do not exhibit augmented stability with respect to analogous catalysts based on (C6F5)4PFe and (C3F7)4PFe species. The data presented are consistent with a hydrocarbon oxidation process in which PFe complexes play dual roles of radical chain initiator, and the species responsible for the catalytic decomposition of organic peroxides. This modified Haber-Weiss reaction scheme provides for the decomposition of tert-butyl hydroperoxide intermediates via reaction with PFe-OH complexes; the PFeIII species responsible for hydroperoxide decomposition are regenerated by reaction of PFeII with dioxygen under these experimental conditions.
Reaction of 4-trans-(N,N-dimethylamino)cinnamaldehyde with the liver alcohol dehydrogenase-NAD+ complex (1984)

Evidence that horse liver alcohol dehydrogenase forms a ternary complex with 4-trans-(N,N-dimethylamino)cinnamaldehyde (DACA) and oxidized nicotinamide adenine dinucleotide (NAD+) is presented. Formation of the complex is characterized by a 97-nm red shift of the free chromophore to 495 nm (epsilon 495 approximately 6.0 X 10(4) M-1 cm-1). This shift is larger than the 66-nm red shift of the E(NADH,-DACA) complex (lambda max = 464 nm) previously reported by Dunn and Hutchinson [Dunn, M.F., & Hutchison, J.S. (1973) Biochemistry 12, 4882-4892]. The large red shift of the E(NAD+,DACA) complex is due to the combined effects of coordination of the carbonyl oxygen of DACA to the active-site zinc ion and to the close proximity of the positively charged nicotinamide ring of NAD+. The stability of this complex is pH dependent and depends on a single apparent ionization with pKa = 7.6 +/- 0.3. The pH-independent dissociation constant for binding of DACA to E(NAD+) is 23 +/- 6 microM. The stoichiometry of DACA binding to the E(NAD+) complex is shown to be one per active site (two per enzyme molecule). Liver alcohol dehydrogenase is also shown to catalyze the NAD+-mediated oxidation of DACA to the corresponding carboxylic acid with a very slow turnover rate. The possibility that the observed E(NAD+,DACA) complex is an intermediate in the enzyme-catalyzed oxidation of DACA is discussed.
STAT5 N-domain deleted isoforms are naturally occurring hypomorphs partially rescued in hematopoiesis by transgenic Bcl-2 expression. (2014)

Signal transducer and activator of transcription 5 (STAT5) is a critical regulator of normal and leukemic lympho-myeloid development through activation downstream of early-acting cytokines, their receptors, and JAKs. Truncation of STAT5 can be mediated through alternative translation initiation from an internal start codon giving rise to N-terminally deleted isoforms. To determine whether these isoforms could be detected naturally in normal murine tissues, Western blot analyses were performed on heart, lung, brain, spleen, liver, and kidney. Relative expression of full-length to truncated STAT5 was variable among tissues. Since we have previously demonstrated that STAT5abΔN lacks the ability to effectively upregulate pro-survival signals and bcl-2 expression, we used a transgenic mouse approach to next determine whether constitutive expression of human Bcl-2 in STAT5ab(ΔN/ΔN) mouse hematopoietic cells could restore normal hematopoiesis. Transgenic H2K-Bcl-2 expression in hypomorphic STAT5ab(ΔN/ΔN) mice largely rescued peripheral B and T lymphocyte numbers whereas multilineage donor contribution was only rescued to levels about 10% of normal. At the hematopoietic stem cell level, direct competitive repopulation with H2K-Bcl-2/STAT5ab(ΔN/ΔN) against STAT5ab(ΔN/ΔN) competitor showed a corrective effect of Bcl-2 expression whether the STAT5ab(ΔN/ΔN) genotype was competed as the donor or as the host versus H2K-Bcl-2/STAT5ab(ΔN/ΔN) genotype bone marrow cells. Therefore, STAT5abΔN isoforms are heterogeneously expressed and lack key functional activities that can be partially rescued by adding back Bcl-2.
Smart 155.52 Mb/s burst-mode transceiver with embedded intelligence for time division multiple access (TDMA) passive optical network (PON) applications (1995)

This paper presents a novel design of a burst-mode transceiver with local real-time intelligence for point-to-multipoint upstream transmission at 155.52 Mb/s. Using embedded intelligence for controlling laser drive parameters, and a trailer canceling technique at a receiver, excellent combined performance of high sensitivity (-37 dBm at BER 10<SUP>-9</SUP>), large optical power budget (36 dB), wide dynamic range (33 dB), and short run-in time (26 ns) was successfully demonstrated. It can connect up to 32 subscribers through a passive optical tree network using a burst TDMA scheme.
The Prostaglandin E 1 Analog, Misoprostol, a Normal Tissue Protector, Does Not Protect Four Murine Tumors In Vivo from Radiation Injury (1995)

The clinical development of radioprotectors, such as misoprostol, to protect normal tissue during cancer treatment must proceed with the assurance that tumors are not protected similarly or significantly. To provide data on this critical question, radiation-induced growth delay with or without the presence of misoprostol was measured in four murine tumors grown in the flanks of mice: the Lewis lung carcinoma, M-5076 ovarian sarcoma, FSA and NFSA. The effect of misoprostol on the tumor control dose (TCD50) of radiation was measured in FSA-bearing mice with or without prior treatment with the nonsteroidal anti-inflammatory agent, indomethacin. Misoprostol did not influence the in vivo growth of any of the four tumors, nor did it protect any of the tumors from radiation-induced growth delay. Likewise, there was no increase in the radiation TCD50 to treat the FSA in vivo in control or indomethacin-treated tumor-bearing mice. To measure any possible influence of tumor burden on the protective effect of misoprostol on normal tissue in mice, the protective effect of misoprostol on the survival of intestinal clonogenic cells was measured in M-5076-bearing mice and found to be the same as in non-tumor-bearing mice. These data suggest that misoprostol protects normal tissue in mice without protecting at least four experimental murine tumors. The data support the contention that misoprostol can achieve therapeutic gain by protecting normal tissues without protecting tumors.
Influence of Pyramid Size of Chemically Textured Silicon Wafers on the Characteristics of Industrial Solar Cells (2010)

Pyramidal texture on monocrystalline silicon wafers is a very common surface structure of industrial monocrystalline silicon solar cells because of its advantage to reduce light reflection. However, pyramidal texture with big pyramids (15 μm) or small pyramids (0.3 μm) produce lower performance of solar cells. By using a wet chemical method we produced a pyramidal texture on (100) p-type Czochralski monocrystalline silicon wafers. We achieved pyramidal texture with pyramid size between 1 μm and 6 μm. After that, we processed industrial silicon solar cells by using the screen printing method. Solar cells achieved efficiencies between 16.7 % and 17.7 %.
Modelling cooperation in mobile ad hoc networks: a formal description of selfishness (2003)

The advance in wireless technologies makes now viable to start to develop ad hoc networks. However, without a mechanism that prevents misbehaviors, these networks could result easily unreliable. We develop a model, based on game theory, capable of formally explaining characteristics of ad hoc networks (as the nodes&apos; selfishness or the network mobility). It also allows to formally study and analyze strategies for cooperation. As example, we describe a simple strategy that enforces packet forwarding among nodes.
The Photochemical Generation and Intramolecular Chemistry of β-Acetoxycarbene (2002)

The photolytic precursor to, acetic acid 1a,9b-dibydro-1H- cyclopropa[1]phenanthren-l-yl methyl ester, was prepared in two steps from phenanthrene. Photolysis of the precursor generated β-acetoxycarbene, an intermediate, which rearranged to vinyl acetate in a yield of 18%. Conspicuously absent in the reaction mixture is γ•butyrolactone, a product that could have arisen via an intramolecular C-H insertion to seal the ring. Three intramolecular mechanisms were considered to account for the formation of vinyl acetate from the carbene. Deuterium labeling of the methylene group of the carbene was used to demonstrate that a simple 1;1- H shift was the principle mode of rearrangement, accounting for 82% of the vinyl acetate. Most interesting, however, is that the remaining vinyl acetate appears to arise from other mechanisms. Computational studies (B3LYP/6-31 G*) found a triplet minimum and two slightly less stable singlet minima for the carbene. The l,2-H shift was found to have an especially low barrier in two separate theoretical investigations.
Histone H3 as a novel substrate for MAP kinase phosphatase-1 (2008)

Mitogen-activated protein (MAP) kinase phosphatase-1 (MKP-1) is a nuclear, dual-specificity phosphatase that has been shown to dephosphorylate MAP kinases. We used a "substrate-trap" technique involving a mutation in MKP-1 of the catalytically critical cysteine to a serine residue ("CS" mutant) to capture novel MKP-1 substrates. We transfected the MKP-1 (CS) mutant and control (wild-type, WT) constructs into phorbol 12-myristate 13-acetate (PMA)-activated COS-1 cells. MKP-1-substrate complexes were immunoprecipitated, which yielded four bands of 17, 15, 14, and 10 kDa with the CS MKP-1 mutant but not the WT MKP-1. The bands were identified by mass spectrometry as histones H3, H2B, H2A, and H4, respectively. Histone H3 was phosphorylated, and purified MKP-1 dephosphorylated histone H3 (phospho-Ser-10) in vitro; whereas, histone H3 (phospho-Thr-3) was unaffected. We have previously shown that thrombin and vascular endothelial growth factor (VEGF) upregulated MKP-1 in human endothelial cells (EC). We now show that both thrombin and VEGF caused dephosphorylation of histone H3 (phospho-Ser-10) and histone H3 (phospho-Thr-3) in EC with kinetics consistent with MKP-1 induction. Furthermore, MKP-1-specific small interfering RNA (siRNA) prevented VEGF- and thrombin-induced H3 (phospho-Ser-10) dephosphorylation but had no effect on H3 (phospho-Thr-3 or Thr-11) dephosphorylation. In summary, histone H3 is a novel substrate of MKP-1, and VEGF- and thrombin-induced H3 (phospho-Ser-10) dephosphorylation requires MKP-1. We propose that MKP-1-mediated H3 (phospho-Ser-10) dephosphorylation is a key regulatory step in EC activation by VEGF and thrombin.
Preparation of allogeneic cartilage and bone for grafting. (1978)

Seroma formation was most apparent in the A-treated groups and was probably related to the continued leakage of methyl alcohol from the graft. Warping in the pinna, fibrosis around grafts, graft resorption, and cellular infiltration were least evident in the FZ and R groups. Both produced better results than storage in BSS or A, but because radiation is far more expensive and less convenient than FZ, the latter is the better preparation and preservation technique.
A phosphatase activity in <i>Xenopus</i> oocyte extracts preferentially dephosphorylates the MPM‐2 epitope (1998)

MPM‐2 antigens are a large family of mitotic phosphoproteins that contain similar phosphoepitopes recognized by the anti‐phosphoepitope antibody MPM‐2 (MPM‐2 epitopes). These proteins are phosphorylated during M phase induction and dephosphorylated from the onset of anaphase through interphase. Since biochemical characterization of the MPM‐2 epitope phosphatase requires a specific assay for its activity, we tested different methods for measurement of the MPM‐2 epitope phosphatase activity in crude cell lysates. First, an ELISA‐based assay was designed that measured the phosphatase‐induced reduction of the MPM‐2 reactivity in crude M phase cell lysates. Using this assay to follow the phosphatase activity during sequential chromatography of Xenopus oocyte extracts, one predominant peak of phosphatase activity was detected which was separated from the majority of PP1 and PP2A activities. This phosphatase activity dephosphorylated the MPM‐2 epitope on multiple MPM‐2 antigens. The second method measured dephosphorylation of cdc25, a known MPM‐2 antigen. Two major peaks of cdc25 dephosphorylating activities were detected during the sequential chromatography, one that copurified with the major peak of MPM‐2 epitope phosphatase activity, and the other with the major peak of PP2A activity. Finally, we examined whether GST‐MPM2, a fusion protein between glutathione S ‐transferase and a 19‐residue peptide that contained two representative MPM‐2 epitope sequences, could be dephosphorylated efficiently and specifically by the major MPM‐2 epitope phosphatase activity in Xenopus oocyte extracts. Neither the crude extract nor the partially purified MPM‐2 epitope phosphatase activity efficiently dephosphorylated the MPM‐2 epitope on GST‐MPM2. These results demonstrate that the ELISA‐based assay preferentially detects the MPM‐2 epitope phosphatase activity in crude cell lysates which may represent a physiological MPM‐2 epitope phosphatase.
Diffusion of nitric oxide can facilitate cerebellar learning: A simulation study (2000)

The gaseous second messenger nitric oxide (NO), which readily diffuses in brain tissue, has been implicated in cerebellar long-term depression (LTD), a form of synaptic plasticity thought to be involved in cerebellar learning. Can NO diffusion facilitate cerebellar learning? The inferior olive (IO) cells, which provide the error signals necessary for modifying the granule cell-Purkinje cell (PC) synapses by LTD, fire at ultra-low firing rates in vivo, rarely more than 2-4 spikes within a second. In this paper, we show that NO diffusion can improve the transmission of sporadic IO error signals to PCs within cerebellar cortical functional units, or microzones. To relate NO diffusion to adaptive behavior, we add NO diffusion and a "volumic" LTD learning rule, i.e., a learning rule that depends both on the synaptic activity and on the NO concentration at the synapse, to a cerebellar model for arm movement control. Our results show that biologically plausible diffusion leads to an increase in information transfer of the error signals to the PCs when the IO firing rate is ultra-low. This, in turn, enhances cerebellar learning as shown by improved performance in an arm-reaching task.