gebhart/patrepeval huggingface dataset:
Meteosat Third Generation (MTG) status of space segment definition (2009)

ESA and EUMETSAT have initiated joint preparatory activities for the formulation and definition of the Meteosat Third Generation (MTG) geostationary system to ensure the future continuity, and enhancement, of the current Meteosat Second Generation (MSG) system. The MTG programmatics are being established to ensure a seamless transition between the conclusion of the successful MSG operational system and the start of the new MTG operational system, with particular emphasis on continuity of the imagery missions. The MTG phase A studies were successfully concluded in December 2008 an re-consolidation phase B1 activities continued from January to July 2009. They were devoted to the MTG concept definition and requirements consolidation for meeting the User needs in the field of Nowcasting and Very Short Term Weather Forecasting (NWC), Medium/Short Range global and regional Numerical Weather Prediction (NWP), Climate, Air Quality and Composition Monitoring. The following missions have been analysed, measurement techniques studied and preliminary concepts established: - High Resolution Fast Imagery Mission (improved successor to MSG SEVIRI HRV mission) - Full Disk High Spectral Resolution Imagery Mission (improved successor to SEVIRI) - Lightning Imagery Mission - IR Sounding Mission - UV-VIS-NIR Sounding Mission Both space segment architecture and preliminary satellite and instrument concepts were investigated in the course of these studies, and a dual satellite configuration established comprising the Imaging satellite (MTG-I) and the sounding satellite (MTG-S). The study covered all elements to a level of detail allowing to establish a technical baseline, conclude on the feasibility of the system requirements and undertake preliminary programmatic evaluation. Riders to the Phase A studies (Phase B1 work) have been placed to further consolidate the satellite and payload definition and development, prior to the release of the Invitation To Tender (ITT) for the full space segment implementation in July 2009. This paper provides an overview of the conclusions of those MTG space segment studies. It summarises the conclusions reached for the satellites, and associated instruments relating to Imaging, IR Sounding and Lightning missions, with respect to achievable performances, including Radiometry and Image Navigation and Registration aspects.
Peptide uptake is essential for growth of Lactococcus lactis on the milk protein casein (1989)

The chlorated dipeptide L-alanyl-beta-chloro-L-alanine (diACA) is very toxic for Lactococcus lactis. Spontaneous mutants resistant to the dipeptide were isolated from plates. The presence and activities of cell wall-associated proteinase, different peptidases in cell extracts, amino acid transport systems, and di- and oligopeptide transport systems were examined and compared in a diACA-resistant mutant and the wild type. Only the rates of di- and tripeptide transport were found to be significantly reduced in the diACA-resistant mutant of L. lactis ML3. Since all other characteristics of this mutant were comparable to those of the wild type, the diACA-resistant mutant is most likely deficient in di- and tripeptide transport. Uptake of di- and tripeptides by L. lactis ML3 was found to be mainly mediated by one peptide transport system. The peptide transport-deficient mutant was found to be unable to grow on a chemically defined medium supplemented with casein as the sole nitrogen source, whereas growth could be restored by the addition of amino acids. These results indicate that peptide transport in L. lactis ML3 is an essential component in the process of casein utilization during growth in milk.
<i>Tert</i>-BuOK/BuLi-Induced Facile Cyclodehydrogenation of Diphenyl Sulfide to Dibenzothiophene (2003)

Attempted double ortho-lithiation of diphenyl sulfide using two equivalents of butyllithium in the presence of potassium tert-butoxide in diethyl ether-THF at room temperature under argon resulted in facile cyclodehydrogenation to afford dibenzothiophene in moderate yield.
Determination of the quantum yield of the ferrioxalate actinometer with electrically calibrated radiometers (1981)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of the quantum yield of the ferrioxalate actinometer with electrically calibrated radiometersJ. N. Demas, W. D. Bowman, E. F. Zalewski, and R. A. VelapoldiCite this: J. Phys. Chem. 1981, 85, 19, 2766–2771Publication Date (Print):September 1, 1981Publication History Published online1 May 2002Published inissue 1 September 1981https://pubs.acs.org/doi/10.1021/j150619a015https://doi.org/10.1021/j150619a015research-articleACS PublicationsRequest reuse permissionsArticle Views2971Altmetric-Citations86LEARN 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 options Get e-Alerts
Improving the Stability and Sensing of Electrochemical Biosensors by Employing Trithiol-Anchoring Groups in a Six-Carbon Self-Assembled Monolayer (2009)

Alkane thiol self-assembled monolayers (SAMs) have seen widespread utility in the fabrication of electrochemical biosensors. Their utility, however, reflects a potentially significant compromise. While shorter SAMs support efficient electron transfer, they pack poorly and are thus relatively unstable. Longer SAMs are more stable but suffer from less efficient electron transfer, thus degrading sensor performance. Here we use the electrochemical DNA (E-DNA) sensor platform to compare the signaling and stability of biosensors fabricated using a short, six-carbon monothiol with those employing either of two commercially available trihexylthiol anchors (a flexible Letsinger type and a rigid adamantane type). We find that all three anchors support efficient electron transfer and E-DNA signaling, with the gain, specificity, and selectivity of all three being effectively indistinguishable. The stabilities of the three anchors, however, vary significantly. Sensors anchored with the flexible trithiol exhibit enhanced stability, retaining 75% of their original signal and maintaining excellent signaling properties after 50 days storage in buffer. Likewise these sensors exhibit excellent temperature stability and robustness to electrochemical interrogation. The stability of sensors fabricated using the rigid trithiol anchor, by comparison, are similar to those of the monothiol, with both exhibiting significant (>60%) loss of signal upon wet storage or thermocycling. Employing a flexible trithiol anchor in the fabrication of SAM-based electrochemical biosensors may provide a means of improving sensor robustness without sacrificing electron transfer efficiency or otherwise impeding sensor performance.
Thermal and photostimulated reactions on Si2H6-adsorbed Si(100)2×1 surfaces: Mechanisms of Si film growth by atomic-layer epitaxy (1989)

Electron energy-loss spectroscopy (EELS) and reflection high-energy electron diffraction (RHEED) have been used to investigate thermal and photothermal reactions in dihydride (1×1)::2H surfaces obtained by dosing clean Si(100)2×1 surfaces to a saturation exposure (≊2×1017 cm−2) of Si2H6 at 300 K. With 15-s anneals at progressively higher temperatures, the (1×1)::2H was transformed to a (2×1):H monohydride phase at temperatures between 655 and 725 K and most of the remaining H evolved by 765 K. Complete recovery of the initial clean-surface EELS spectrum and 2×1 RHEED pattern, signaling deposition of one layer of epitaxial Si(100)2×1, was obtained between 845 and 955 K. One pulse of 120 mJ cm−2 ArF laser-beam irradiation resulted in significant hydrogen evolution from Si2H6-saturated dihydride surfaces at 300 K and complete hydrogen desorption, with the reestablishment of the initial clean-surface EELS spectrum, at 525 K. The mechanism was found to be photothermal rather than photolytic and the maximum temperature during the ≊20-ns pulse (at 525-K starting temperature) was calculated to be 800 K. RHEED patterns from dihydride surfaces irradiated at 525 K were 2×1, but with slightly weakened half-order diffraction spot intensities. In initial film growth experiments using continuous Si2H6 dosing and pulsed ArF laser irradiation, epitaxial Si was obtained at a steady-state temperature of 525 K.
Uplink Arrays for the Deep Space Network (2007)

Deep-space communication and navigation is faced with two challenges in the future: (1) the potential retirement of the largest antennas of NASA's Deep Space Network and (2) an anticipated need for increasing ground system capacity so as to support higher data rates to and from missions operating at remote locations in the solar system, as well as in anticipation of a larger number of simultaneously flying missions. In the transmitting, or uplink, direction, one approach to increasing the effective transmitted power is to array multiple antennas. This is attractive mainly because it promises a lower construction cost than equivalent (large) single antenna systems. In addition, it has the potential for increasing the reliability of the uplink and reducing maintenance costs. This paper introduces the concept of uplink arraying by examining technological challenges and possible solutions to them. Arraying principles are presented and error sources described. The main challenge is to maintain carrier phase alignment among the antennas, and this must be done by periodic calibration. Presently, two calibration methods are being developed at the Jet Propulsion Laboratory as part of an uplink arraying demonstration effort. These methods are briefly discussed.
Dexamethasone and Oxytetracycline Reverse the Potentiation of Neurogenic Inflammation in Airways of Rats with Mycoplasma Pulmonis Infection (1994)

Mycoplasma pulmonis infection in rats causes a chronic inflammatory airway disease. Along with extensive remodeling of the airway mucosa, lymphocytic infiltrates, angiogenesis, and mucosal thickening, there is an abnormal sensitivity of the blood vessels to mediators that evoke "neurogenic inflammation". As a result, substance P, a peptide released from sensory nerves, produces an unusually large amount of plasma leakage. These changes can be prevented or reduced by prophylactic treatment with antibiotics, but it is unknown whether the extensive remodeling of the airway mucosa and potentiation of neurogenic inflammation can be reversed once they are established. We addressed this issue in F344 rats that were infected with M. pulmonis at 8 wk of age. Six weeks later, the rats were treated daily with an antibiotic (oxytetracycline, 20 mg/kg intramuscularly), to reduce the number of infecting organisms, or with an antiinflammatory steroid (dexamethasone, 0.5 mg/kg intraperitoneally), to reduce the inflammatory and immunologic response to the infection. Sham-treated infected rats received daily injections of 0.9% NaCl. After 1, 2, or 4 wk of treatment the rats were anesthetized and then challenged with substance P (5 micrograms/kg intravenously). The sham-treated rats had pathologic changes in their airways typical of severe M. pulmonis infection, and had as much as a threefold increase in substance P-induced plasma leakage. By comparison, after 4 wk of treatment with oxytetracycline or dexamethasone, the chronic inflammation was nearly resolved and the response to substance P was in the normal range. Unexpectedly, dexamethasone, like oxytetracycline, reduced the number of infecting organisms.(ABSTRACT TRUNCATED AT 250 WORDS)
Widespread occurrence in animal tissues of an enzyme catalyzing the conversion of NAD+ into a cyclic metabolite with intracellular Ca2+-mobilizing activity (1989)

A metabolite with intracellular Ca2+-mobilizing activity can be produced by incubating NAD+ with extracts from sea urchin eggs. Structural determination indicates it is a cyclized ADP-ribose, and we have proposed cyclic ADP-ribose as a common name for it. In this study, we addressed the question of how widespread is the occurrence of the synthesizing enzyme for this NAD+ metabolite. Incubation of NAD+ with extracts prepared from rabbit liver resulted in a progressive increase in Ca2+ release activity which was monitored by a biological assay using sea urchin egg homogenates. The half-maximal concentration of NAD+ required was about 1 mM. The reaction was stereospecific, and the extracts were sensitive to protease treatment and heat, as well as alkaline pH of about 9.0, indicating the reaction was catalyzed by a protein. The active metabolite was purified by an identical high pressure liquid chromatography (HPLC) procedure used for cyclic ADP-ribose. Functionally, the liver metabolite behaved similarly to cyclic ADP-ribose. Both discharged the same Ca2+ stores in sea urchin egg homogenates with the same half-maximal effective concentrations. Both were active in inducing the cortical exocytosis reaction when microinjected into sea urchin eggs. That they are indeed identical compounds was demonstrated by structural analyses showing that they coeluted on a Partisil 5 SAX HPLC column and had identical 1H NMR spectra. Mass spectrometry indicated a mass of 540.0529 for the molecular ion (M - H)- of the liver metabolite, which was identical to within 0.74 ppm of cyclic ADP-ribose. Furthermore, their collisional activated decomposition mass spectra were virtually superimposable. Extracts from rabbit brain, heart, spleen, and kidney were all active in producing similar Ca2+-releasing metabolites which could be isolated by the same HPLC procedure and had similar elution times on both the mixed mode and the Partisil 5 SAX column. It is therefore apparent that the synthesizing enzyme for cyclic ADP-ribose is a very common enzyme.
A Temporal Order Resolution Algorithm in the Multi-server Time Stamp Service Framework (2005)

This paper describes solutions to resolve chronological orders of time stamps issued by multiple time stamp authorities (TSAs). The communication, computation, and storage overhead to provide such a service is considerably low. The correctness of the proposed algorithm is proved and the worst-case computation bound is also derived. The proposed resolution algorithm and the supporting "cross reference mark" server strategy can be applied in a multi-server timestamp service (TSS) framework with trusted or distrusted servers to obtain deterministic time stamp comparison results.
Photooptical Switching of Polymer Film Waveguide Containing Photochromic Diarylethenes (1994)

Fabrication of a photooptical switching device based on the photo-induced refractive index change of polymer film doped with photochromic compounds is described. 1,2-bis(2-methylbenzo[b]thiophen-3-yl) perfluorocyclopentene (BFCP) and 1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene (CMTE) were used as the photochromic compounds. A transformation in the compounds from the opened-ring to closed-ring form was induced by irradiation with a He–Cd laser (325 nm) and the reverse reaction with an Ar ion laser (488 nm). The polymer films containing BFCP and CMTE showed a refractive index change, Δ n , as large as 5×10 -4 / wt% photoisomerized chromophores. Photooptical switching of a prism-coupling device was demonstrated by alternate irradiation with Ar ion and He–Cd lasers, and also by irradiation with a pulsed YAG laser.
Simple methods for monitoring HIV-1 and HIV-2 gp120 binding to soluble CD4 by enzyme-linked immunosorbent assay (1990)

Sensitive enzyme-linked immunosorbent assay-based methods are described for monitoring the binding of envelope glycoproteins from HIV-1 and HIV-2 to soluble CD4 (sCD4). Each of the assays has different properties suitable for different applications, but all can be used to characterize recombinant antigens and to screen for inhibitors of the gp120-CD4 interaction. Recombinant mammalian gp120 (Celltech) binds to sCD4 with high affinity (3 nM); this interaction is inhibited by sera from HIV-infected individuals and by specific monoclonal and polyclonal antibodies raised to a component of the CD4 binding site on gp120. The affinity for sCD4 of HIV-2 viral gp120 is shown to be approximately 25-fold lower than that of HIV-1 gp120 (viral or recombinant).
Chemokine CXCL1/KC and its Receptor CXCR2 Are Responsible for Neutrophil Chemotaxis in Adenoviral Keratitis (2009)

Epidemic keratoconjunctivitis (EKC), caused by human adenovirus (HAdV), is one of the most common ocular infections and results in corneal inflammation and subepithelial infiltrates. Adenoviral keratitis causes significant morbidity to the patients, and is characterized by infiltration of leukocytes in the corneal stroma, and expression of chemokines. The exact role of these chemokines in adenoviral infection has not been studied due to lack of animal models. Here, we have characterized the role of chemokine CXCL1/KC and receptor CXCR2 in adenoviral keratitis using a novel mouse model. Analysis of chemokine expression, leukocyte infiltration, and development of keratitis was performed by ELISA, flow cytometry, and histopathology, respectively. Deficiency of CXCL1 and CXCR2 resulted in delayed infiltration of neutrophils, but not inflammatory monocytes in HAdV-37 corneal infection. CXCL1(-/-) mice showed decreased expression of CXCL2/MIP-2, but not CCL2/MCP-1. CXCR2(-/-) mice showed increased expression of CXCL1 and CXCL2, but not CCL2. Both CXCL1(-/-) and CXCR2(-/-) mice demonstrated keratitis similar to wild-type mice. In conclusion, both CXCL1 and CXCR2 play an important role in chemokine expression and neutrophil infiltration following adenoviral corneal infection, but have a redundant role in the development of keratitis.
Liquid and gaseous fuels from biotechnology: challenge and opportunities (1995)

This paper presents challenging opportunities for production of liquid and gaseous fuels by biotechnology. From the liquid fuels, ethyl alcohol production has been widely researched and implemented. The major obstacle for large scale production of ethanol for fuel is the cost, whereby the substrate represents one of the major cost components. Various scenarios will be presented for a critical assessment of cost distribution for production of ethanol from various substrates by conventional and high rate processes. The paper also focuses on recent advances in the research and application of biotechnological processes and methods for the production of liquid transportation fuels other than ethanol (other oxygenates; diesel fuel extenders and substitutes), as well as gaseous fuels (biogas, methane, reformed syngas). Potential uses of these biofuels are described, along with environmental concerns which accompany them. Emphasis is also put on microalgal lipids as diesel substitute and biogas/methane as a renewable alternative to natural gas. The capturing and use of landfill gases is also mentioned, as well as microbial coal liquefaction. Described is also the construction and performance of microbial fuel cells for the direct high-efficiency conversion of chemical fuel energy to electricity. Bacterial carbon dioxide recovery is briefly dealt with as an environmental issue associated with the use of fossil energy.
8‐[2‐(2‐pentyl‐cyclopropylmethyl)‐cyclopropyl]‐octanoic acid stimulates GABA release from interneurons projecting to CA1 pyramidal neurons in the rat hippocampus via pre‐synaptic α7 acetylcholine receptors (2005)

Nicotinic acetylcholine (ACh) receptors, such as alpha7, alpha3beta4 and alpha4beta2 receptors in the hippocampus, are suggested to modulate neurotransmitter release. 8-[2-(2-Pentyl-cyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA) (100 nM), a linoleic acid derivative, potentiated responses of alpha7, alpha3beta4 and alpha4beta2 ACh receptors expressed in Xenopus oocytes that are blocked by 3-(1-[dimethylaminopropyl] indol-3-yl)-4-[indol-3-yl] maleimide (GF109203X), a selective inhibitor of protein kinase C (PKC), except for alpha3beta4 ACh receptors. DCP-LA enhanced the nicotine-triggered release of GABA from rat hippocampal slices in the presence of tetrodotoxin in a bell-shaped dose-dependent manner at concentrations ranging from 10 nM to 10 microM, although DCP-LA by itself had no effect on GABA release. The DCP-LA action was inhibited by GF109203X or alpha-bungarotoxin, an inhibitor of alpha7 ACh receptors, but not by mecamylamine or dihydro-beta-erithroidine, an inhibitor of alpha3beta4 and alpha4beta2 ACh receptors. A similar effect on GABA release was obtained with 12-O-tetradecanoylphorbol 13-acetate, a PKC activator. DCP-LA (100 nM) also enhanced GABA release triggered by choline, an agonist of alpha7 ACh receptors, but not 3-[2(s)-azetidinylmethoxy] pyridine, an agonist of alpha4beta2 ACh receptors. In addition, DCP-LA (100 nM) increased the rate of nicotine-triggered GABA(A) receptor-mediated miniature inhibitory post-synaptic currents, monitored from CA1 pyramidal neurons of rat hippocampal slices, and the effect was also inhibited by GF109203X or alpha-bungarotoxin but not by mecamylamine. Thus, the results of the present study indicate that DCP-LA stimulates GABA release by enhancing activity of pre-synaptic alpha7 ACh receptors present on the GABAergic terminals of interneurons that transmit to CA1 pyramidal neurons via a PKC pathway.
The Effects of Compression and Pore Size Variations on the Liquid Flow Characteristics in Metal Foams (2001)

Open-cell aluminum foams were investigated using water to determine their hydraulic characteristics. Maximum fluid flow velocities achieved were 1.042 m/s. The permeability and form coefficient varied from 2.46×10−10 m2 and 8701 m−1 to 3529×10−10 m2 and 120 m−1, respectively. It was determined that the flowrate range influenced these calculated parameters, especially in the transitional regime where the permeability based Reynolds number varied between unity and 26.5. Beyond the transition regime where ReK≳30, the permeability and form coefficient monotonically approached values which were reported as being calculated at the maximum flow velocities attained. The results obtained in this study are relevant to engineering applications employing metal foams ranging from convection heat sinks to filters and flow straightening devices.
Degradation of a Pneumococcal Type-Specific Polysaccharide with Exposure of Group-Specificity (1970)

Pyruvic acid is an immunological determinant of the quite rigorously type-specific capsular polysaccharide of pneumococcal type IV (S IV). Removal of pyruvic acid by mild hydrolysis converts the capsular polysaccharide of type IV into an analog of the pneumococcal group-specific C-substance. Depyruvylated S IV resembles C-substance so closely immunologically that it not only precipitates a high proportion of the anti-C in antipneumococcal sera, regardless of their immunological types, but also, like C, precipitates human C-reactive protein in the presence of calcium ions. Apparently, the removal of pyruvic acid ketal rings from adjacent sugars unmasks N-acetylgalactosamine residues which must be linked and spaced much as are those in C-substance. Groupings reactive with suitably linked N-acetylgalactosamine, therefore, appear to be located on the surfaces of molecules of human C-reactive protein.