bluuebunny/crossref_metadata_2025_split huggingface dataset:
ABRIXAS — A BRoad‐band Imaging X‐ray All‐sky Survey
Authors: Trümper J. E. , Hasinger G. , Staubert R. 
Published: July 2007

AbstractABRIXAS is an X‐ray satellite with seven 27‐fold nested Wolter‐1 telescopes, sharing one pn‐CCD detector in the focus. It will be launched in spring of 1999. ABRIXAS will perform the first imaging all‐sky survey above 2 keV. During a three‐year scanning mission it is expected to detect at least 10.000 new hard X‐ray sources obscured by gas and dust clouds. It will also study large diffuse X‐ray sources and the time variability of bright X‐ray sources.
Operational capabilities of AXAF for surveys
Authors: Schwartz D. A. 
Published: July 2007

AbstractThe Advanced X‐ray Astrophysics Facility (AXAF) will offer us all great opportunities for surveys. The exceptional resolution of the AXAF mirrors, will yield unsurpassed deep surveys, and the energy resolution of the ACIS will allow unique contributions to the AXAF version of previous “medium sensitivity” and “slew” surveys. At this workshop we presented some preliminary results of the calibration of the AXAF flight mirrors. Off‐axis imaging, chromatic effects of vignetting, and the asymmetry of the off‐axis response will be important for planning and analyzing surveys.
Present Epoch Plus — an X‐ray survey for cosmology
Authors: Jahoda K. 
Published: July 2007

AbstractThis paper summarizes some cosmologically interesting measurements which are uniquely possible in the hard X‐ray band and presents a mission concept capable of achieving them. The Present Epoch Plus mission will achieve a surface brightness sensitivity of better than 1% per square degree in the 2–10 keV band, and create a catalog of ∽ 106 sources. About 160,000 extragalactic sources are expected to be detected in the 2–10 keV band, providing an all sky survey with nearly uniform selection effects 10 times deeper than existing or planned surveys. The PEP concept can be achieved within the size and budgetary constrraints of a NASA Medium Explorer (MIDEX) mission.
Surveying the hard X‐ray sky: imaging in space and time
Authors: Grindlay J. E. 
Published: July 2007

AbstractOne of the few remaining astronomical bands (factor of ∽ 10 in energy range) still without an all‐sky imaging survey is the hard x‐ray band (10–600 keV). This is in spite of sensitive imaging all‐ sky surveys already conducted at soft x‐ray (0.2‐2 keV; ROSAT) and soft/hard γ‐ray (∽750 keV ‐ 10 GeV; COMPTEL/EGRET) energies and imminent for medium x‐ray energies (2–10 keV; ABRIXAS). A hard x‐ray imaging survey conducted with wide‐field coded aperture telescopes allows both hight sensitivity (and spatial/spectral resolution) and broad temporal coverage. We derive a generalized survey sensitivity/temporal parameter, Q, and compare previous and planned hard x‐ray surveys with the proposed EXIST mission. Key scientific objectives that could be addressed with the enhanced capability of EXIST are outlined.
An AllNAG8–1212sky Survey for Tens of keV
Authors: Gruber D. E. , Matteson J. , Coburn W. , Heindl W. , Pelling M. , Peterson L. E. , Rothschild R. E. , Skelton T. , Hink P. 
Published: July 2007

AbstractThe HEXIS (High Energy X‐Ray Imaging Spectrometer) is a MIDEX‐class mission concept to perform a deep survey and continuous monitoring of nearly the entire sky in the 5–200 keV band. It uses arrays of position‐sensitive Cadmium‐Zinc Telluride (CZT) detectors and coded masks to achieve 26′ resolution and a 5 sigma sensitivity (> 20 keV) of 4 milliCrab in one day and 0.2 milliCrab in one year. With these capabilities it is estimated that ∽5000 sources can be discovered and localized and have their spectra and variability characterized. Hundreds of gamma‐ray bursts would be detected each year and localized to < 20′. HEXIS also contains a narrow field, 5°, coded mask imager for detailed studies of selected regions. This has three arc minute resolution and is seven times more sensitive than the all‐sky system. The HEXIS detector concept uses crossed strip readout to achieve 0.5 mm resolution pixels for large area arrays, ∽ 400 cm2. This technique is under development at UCSD and Washington University. Detectors have been studied with tuneable monochromatic x‐ray beams and mapped with finely collimated 30 micron beams. These results show that the crossed strip readout has the necessary spatial and spectral characteristics. The HEXIS concept is described and results are presented on the detectors' spatial and spectral properties.
A new X‐ray mission to measure the power spectrum of fluctuations in the Universe
Authors: Barcons X. , Fabian A. C. 
Published: July 2007

AbstractWe propose a new, simple, dedicated X‐ray mission to measure the power spectrum of density fluctuations in the Universe, by accurately mapping the X‐ray background on the whole sky on scales of ∽ 1 deg2. Since the method relies on the detection of excess fluctuations produced by the clustering of X‐ray sources at intermediate redshifts above the confusion noise produced by bright foreground sources, counting noise and systematic noise need to be kept to a minimum. We propose a proportional counter with collimated fields of view of various sizes as the optimal instrument for this mission.
Identification of new low‐mass members of the Alpha Persei open cluster by ROSAT. II
Authors: Prosser C. F. , Randich S. , Simon T. 
Published: July 2007

AbstractThe present investigation examines possible optical counterparts to 130 X‐ray sources in the region of the α Persei open cluster (d ∽ 170pc, age ∽ 50 Myr) resulting from the analysis of three 22–25 ksec ROSAT PSPC pointings. In the same manner as for 73 X‐ray sources from a raster survey in α Per (Prosser & Randich 1998), CCD photometry is employed to obtain magnitudes and colors for stars/objects close to the X‐ray positions, with additional echelle and low‐dispersion Hα spectra provided for some stars. For almost 60 X‐ray sources, an optical counterpart with photometry acceptable for cluster membership is identified, some of which can be excluded from membership on the basis of discrepant radial velocity or X‐ray characteristics. On the order of 30 new members or likely members associated with X‐ray sources have been identified based on available data. A photometric rotation period has been obtained for one rapid rotator identified in X‐rays.
The G‐dwarf problem in the solar neighbourhood: a Lagrangian picture. II
Authors: Caimmi R. 
Published: July 2007

AbstractThe current paper investigates how the empirical, G‐dwarf metallicity distribution constrains simple, comoving models of chemical evolution. In doing this, the application of the models to a data sample, performed in a previous paper, is refined and extended. The key idea is that (i) different star formation rates with different mass spectra take place in different phases of evolution, i.e. contraction and equilibrium, and (ii) disk formation begins at a time t = Td and ends at t = Tc, which marks the transition from contraction to equilibrium. In this view, the lowest‐metallicity point of the empirical, differential distribution, consistent with a linear fit, is related to the beginning of disk formation, and an apparent discontinuity point to the transition from contraction to equilibrium. In addition, different linear fits hold on the left (early distribution) and on the right (late distribution) of the discontinuity point. Models consistent with the empirical, G‐dwarf metallicity distribution are related to linear fits on the early and late side. Homologous solutions during the equilibrium phase are analysed in detail with respect to changes in Tc and Ta, the age of the Galaxy. Then we are left with a single free parameter which is relevant to the chemical evolution, i.e. the mass spectrum exponent during the equilibrium phase. The allowed values for the other parameters, thought as a function of the above mentioned one, are plotted for each case. A Salpeter mass spectrum exponent, p = −2.35, is ruled out by the theoretical, lower stellar mass limit, contrary to a Scalo mass spectrum exponent, p = −2.90, in contrast with previous literature. The reasons for this discrepancy are discussed. Our results are marginally consistent with a same initial mass function during the contraction and equilibrium phase, but in this case the disk mass fraction is of the is same order, or less, than the halo mass fraction. It is also investigated how the empirical age‐metallicity relation constrains the duration of the contraction phase, for a reasonable upper limit of Ta. Keeping in mind that the empirical, G‐dwarf metallicity distribution has not been corrected for the large cosmic scatter shown by the empirical, age‐metallicity relation, we find a duration of disk formation, Tc — Td = 1.07–1.5 Gyr, by a factor 3–5 less than it is found by use of simple infall models. The reasons of this difference are explained. The idea of a massive, white dwarf halo, which seems to be indicated by microlensing experiments, is ruled out by the empirical, G‐dwarf metallicity distribution, in the light of the current model and provided the solar neighbourhood is a typical region of the Galaxy. More refined models involving e.g., the relax of instantaneous recycling would change our results, but the trend is expected to be only slightly altered.
Further improvement of phosphite dehydrogenase thermostability by saturation mutagenesis
Authors: McLachlan Michael J. , Johannes Tyler W. , Zhao Huimin 
Published: July 2007

AbstractPhosphite dehydrogenase represents a new enzymatic system for regenerating reduced nicotinamide cofactors for industrial biocatalysis. We previously engineered a variant of phosphite dehydrogenase with relaxed cofactor specificity and significantly increased activity and stability. Here we performed one round of random mutagenesis followed by comprehensive saturation mutagenesis to further improve the enzyme thermostability while maintaining its activity. Two new thermostabilizing mutations were identified. These, along with the 12 mutations previously identified, were subjected to saturation mutagenesis using the parent enzyme or the engineered thermostable variant 12× as a template, followed by screening of variants with increased thermostability. Of the 12 previously identified sites, 6 yielded new variants with improved stability over the parent enzyme. Several mutations were found to be context‐dependent. On the basis of molecular modeling and biochemical analysis, various mechanisms of thermostabilization were identified. Combining the most thermostabilizing mutation at each site resulted in a variant that showed a 100‐fold increase in half‐life at 62°C over the 12× mutant. The final mutant has improved the half‐life of thermal inactivation at 45°C by 23,000‐fold over the parent enzyme. The engineered phosphite dehydrogenase will be useful in NAD(P)H regeneration. Biotechnol. Bioeng. 2008;99: 268–274. © 2007 Wiley Periodicals, Inc.
Modeling of ferrous iron oxidation by a Leptospirillum ferrooxidans‐dominated chemostat culture
Authors: Sundkvist Jan‐Eric , Gahan Chandra Sekhar , Sandström Åke 
Published: July 2007

AbstractThe objective of this study was to evaluate a direct classical bioengineering approach to model data generated from continuous bio‐oxidation of Fe2+ by a Leptospirillum ferrooxidans‐dominated culture fed with either 9 g or 18 g Fe2+ L−1 under chemostat conditions (dilution rates were between 0.051 and 0.094 h−1). The basic Monod and Pirt equations have successfully been integrated in an overall mass balance procedure, which has not been previously presented in this detail for Fe2+ oxidation. To ensure chemostat conditions, it was found that the range of the dilution rates had to be limited. A too long retention time might cause starvation or non‐negligible death rate whereas, a too short retention time may cause a significant alteration in solution chemistry and culture composition. Modeling of the experimental data suggested that the kinetic‐ and yield parameters changed with the overall solution composition. However, for respective feed solutions only minor changes of ionic strength and chemical speciation can be expected within the studied range of dilution rates, which was confirmed by thermodynamic calculations and conductivity measurements. The presented model also suggests that the apparent Fe3+ inhibition on specific Fe2+ utilization rate was a direct consequence of the declining biomass yield on Fe2+ due to growth uncoupled Fe2+ oxidation when the dilution rate was decreased. The model suggested that the maintenance activities contributed up to 90% of the maximum specific Fe2+ utilization rate, which appears close to the critical dilution rate. Biotechnol. Bioeng. 2008;99: 378–389. © 2007 Wiley Periodicals, Inc.
Development of a minimal defined medium for recombinant human interleukin‐3 production by Streptomyces lividans 66
Authors: Nowruzi Keyvan , Elkamel Ali , Scharer Jeno M. , Cossar Doug , Moo‐Young Murray 
Published: July 2007

AbstractA systematic approach was developed to identify and optimize the essential amino acids in defined minimal medium for the production of recombinant human interleukin 3 (rHuIL‐3) by Streptomyces lividans. Starvation trials were carried out initially to narrow down the number of probable essential amino acids from an initial number of 20 to 8. Then a screening mixture experiment was designed and performed with the eight identified amino acids and distance‐based multivariate analysis was employed to rank the probable essential amino acids regarding both growth and product formation. Following this procedure, the search was narrowed to four amino acids (Asp, Leu, Met, and Phe). Finally, a mixture design experiment known as the simplex lattice design was carried out and the composition of the optimum minimal medium was found (Asp 53%, Met 5%, and Phe 42%). Biotechnol. Bioeng. 2008;99: 214–222. © 2007 Wiley Periodicals, Inc.
Vibrational Study on the Local Structure of Post‐Synthesis and Hybrid Mesoporous Materials: Are There Fundamental Distinctions?
Authors: Vaz Pedro D. , Nunes Carla D. , Vasconcellos‐Dias Maria , Nolasco Mariela M. , Ribeiro‐Claro Paulo J. A. , Calhorda Maria José 
Published: July 2007

AbstractOrganic–inorganic mesoporous materials of the MCM‐41 type are important materials that can be prepared by either post‐synthesis or one‐pot synthesis procedures. A complete control of the characteristics at a local level is of the utmost importance in view of the applications of such materials. However, there are not many studies relating such features with synthetic approaches. In this work, we prepared samples by post‐synthesis derivatization of materials from Si‐based MCM‐41, with bidentate nitrogen ligands bearing one or two silylated arms, and by one‐pot synthesis of organic–inorganic hybrid materials. The bulk properties of the two kinds of materials were comparable. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and Raman spectroscopy were used to investigate the local environment, namely, the number of OH groups and distribution of SiO4 units (large and small ring units). Hydrophilicity correlates with both the type of organic moiety used (mono‐ or disilylated), as well as with the synthetic procedure. The same vibrational studies showed how the structure in the channels changes as a function of pressure, reflecting the low mechanical stability of the mesoporous materials.
Rare Earth‐Rich Magnesium Compounds Ln4RhMg (Ln: Y, La—Nd, Sm, Gd—Tm, Lu).
Authors: Tuncel Selcan , Rodewald Ute Ch. , Chevalier Bernard , Poettgen Rainer 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Wide Compositional and Structural Diversity in the System Tl/Bi/P/Q (Q: S, Se) and Observation of Vicinal P—Tl J Coupling in the Solid State.
Authors: Gave Matthew A. , Malliakas Christos D. , Weliky David P. , Kanatzidis Mercouri G. 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
General Asymmetric Hydrogenation of α‐Branched Aromatic Ketones Catalyzed by TolBINAP/DMAPEN—Ruthenium(II) Complex.
Authors: Arai Noriyoshi , Ooka Hirohito , Azuma Keita , Yabuuchi Toshio , Kurono Nobuhito , Inoue Tsutomu , Ohkuma Takeshi 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Environmentally Benign System for Synthesis of β‐Hydroxylketones: L‐Histidine Asymmetrically Catalyzed Direct Aldol Reactions in Aqueous Micelle and Water‐Like Media.
Authors: Peng Yi‐Yuan , Peng Shu‐Jun , Ding Qiu‐Ping , Wang Qi , Cheng Jin‐Pei 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Ytterbium Triflate Catalyzed Synthesis of β‐Enaminones.
Authors: Epifano Francesco , Genovese Salvatore , Curini Massimo 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Environmentally Benign N‐Boc Protection under Solvent‐ and Catalyst‐Free Conditions.
Authors: Jia Xueshun , Huang Qing , Li Jian , Li Shaoyu , Yang Qiushi 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of γ‐Amino Acid Esters by 1,4‐Addition of Deprotonated α‐Aminonitriles and α‐(Alkylideneamino)nitriles to α,β‐Unsaturated Esters.
Authors: Bergner Ines , Opatz Till 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Diastereoselective Synthesis of Spiro‐β‐lactams via Staudinger Reaction.
Authors: Rojas‐Lima Susana , Santillan‐Sid Lidia , Lopez‐Ruiz Heraclio , Alvarez‐Hernandez Alejandro 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Alkylidenephthalans Through Fluoride‐Induced Cyclization of Electron‐Deficient 2‐Siloxymethylphenylacetylene Derivatives.
Authors: Duan Shaofeng , Cress Karen , Waynant Kris , Ramos‐Miranda Elias , Herndon James W. 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemoselective One‐Pot Conversion of Primary Alcohols to Their Bis(indolyl)methanes Promoted by Bi(NO3)3×5H2O.
Authors: Khosropour Ahmad R. , Mohammadpoor‐Baltork Iraj , Khodaei Mohammad M. , Ghanbary Parvin 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
1,2,3‐Thiadiazole Substituted Pyrazolones as Potent KDR/VEGFR‐2 Kinase Inhibitors.
Authors: Tripathy Rabindranath , Ghose Arup , Singh Jasbir , Bacon Edward R. , Angeles Thelma S. , Yang Shi X. , Albom Mark S. , Aimone Lisa D. , Herman Joseph L. , Mallamo John P. 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Lactams by Radical Substitution Reaction of α,β‐Unsaturated Acyl Radicals at Amine Nitrogen.
Authors: Uenoyama Yoshitaka , Fukuyama Takahide , Ryu Ilhyong 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Novel Functionalized Derivatives of 5‐Nitro‐3,4‐dihydropyrimidin‐2(1H)‐one by the Cyclocondensation of 1‐Chlorobenzyl Isocyanates with N,S‐ and N,N‐Nitroketeneacetals.
Authors: Sukach Volodymyr A. , Bol'but Andriy V. , Petin Alexander Yu. , Vovk Mykhaylo V. 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Orally Active 4‐Amino‐5‐diarylurea‐furo[2,3‐d]pyrimidine Derivatives as Antiangiogenic Agent Inhibiting VEGFR2 and Tie‐2.
Authors: Miyazaki Yasushi , et al. et al. 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Novel Heterocyclic System — Imidazo[5,1‐b][1,3]benzoxazine.
Authors: Osyanin V. A. , Sidorina N. E. 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
New Thermal Rearrangement of 2,4,6‐Triarylthio(seleno)pyrylium Salts.
Authors: Drevko B. I. , Suchkova E. V. , Baranchikova G. A. , Mandych V. G. 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A New Antifeedant Withanolide from Jaborosa lanigera.
Authors: Tettamanzi M. Cristina , Biurrun Fernando N. , Cirigliano Adriana M. 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Daphlongeramine A, Novel Daphniphyllum Alkaloid from Daphniphyllum longeracemosum.
Authors: Li Chunshun , He Hongping , Di Yingtong , Wang Yuehu , Mu Shuzhen , Li Shunlin , Gao Suo , Gao Zhulin , Hao Xiaojiang 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Monohydrocalcite and Its Relationship to Hydrated Amorphous Calcium Carbonate in Biominerals.
Authors: Neumann Markus , Epple Matthias 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Self‐Assembled Growth of PbTiO3 Nanoparticles into Microspheres and Bur‐like Structures.
Authors: Wang Guozhong , Saeterli Ragnhild , Roervik Per Martin , van Helvoort Antonius T. J. , Holmestad Randi , Grande Tor , Einarsrud Mari‐Ann 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
o‐Aminomethyl Derivatives of Phenols. Part 1. Benzylamines: Properties, Structure, Synthesis and Purification
Authors: Bujnowski Krzysztof , Adamczyk Agnieszka , Synoradzki Ludwik 
Published: July 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.