bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Essential Role of the Enhancer for Murine Cytomegalovirus In Vivo Growth and Pathogenesis
Authors: Ghazal Peter , Messerle Martin , Osborn Kent , Angulo Ana 
Published: February 2003

ABSTRACT

The transcription of cytomegalovirus (CMV) immediate-early (IE) genes is regulated by a large and complex enhancer containing an array of binding sites for a variety of cellular transcription factors. Previously, using bacterial artificial chromosome recombinants of the virus genome, it was reported that the enhancer region of murine CMV (MCMV) is dispensable but performs a key function for viral multiplication (A. Angulo, M. Messerle, U. H. Koszinowski, and P. Ghazal, J. Virol.
72:
8502-8509, 1998). In the present study, we defined, through the reconstitution of infectious enhancerless MCMVs, the growth requirement for the enhancer in tissue culture and explored its significance for steering a productive infection in vivo. A comparison of
cis
and
trans
complementation systems for infection of enhancerless virus in permissive fibroblasts revealed a multiplicity-dependent growth phenotype that is severely compromised in the rate of infectious-virus multiplication. The in vivo impact of viruses that have an amputated enhancer was investigated in an extremely sensitive model of MCMV infection, the SCID mouse. Histological examination of spleens, livers, lungs, and salivary glands from animals infected with enhancer-deficient MCMV demonstrated an absence of tissue damage associated with CMV infection. The lack of pathogenic lesions correlated with a defect in replication competence. Enhancerless viruses were not detectable in major target organs harvested from SCID mice. The pathogenesis and growth defect reverted upon restoration of the enhancer. Markedly, while SCID mice infected with 5 PFU of parental MCMV died within 50 days postinfection, all mice infected with enhancerless virus survived for the duration of the experiment (1 year) after infection with 5 × 10
5
PFU. Together, these results clarify the importance of the enhancer for MCMV growth in cell culture and underscore the in vivo significance of this region for MCMV virulence and pathogenesis.
Laser‐induced fluorescence as a powerful detection tool for capillary electrophoretic analysis of heparin/heparan sulfate disaccharides
Authors: Militsopoulou Maria , Lecomte Céline , Bayle Christopher , Couderc Francois , Karamanos Nikos K. 
Published: February 2003

AbstractIn quest for high sensitivities necessary for determining the disaccharide composition of heparin/heparan sulfate present in trace amounts in biologic samples, an ultrahighly sensitive capillary electrophoresis (CE) method using laser‐induced fluorescence (LIF) detection was developed. Heparin/heparan sulfate‐derived Δ‐disaccharides were derivatized with the fluorophore 2‐aminoacridone and resolved by a reversed‐polarity CE method. Estimation of the limit of detection in concentration term and limit of quantitation showed that LIF detection of AMAC‐derivatives of Δ‐disaccharides resulted in 27–744 times higher sensitivity as compared to those detected by UV at 255 nm. These data suggest that CE‐LIF is a powerful tool to quantify minute amounts of heparin/heparan sulfate disaccharides. Copyright © 2003 John Wiley & Sons, Ltd.
Specific determination of unbound oxacillin in protein solution with cefoperazone by high‐performance frontal analysis with chemiluminescence detection
Authors: Li Famei , Qiao Mingxi , Guo Xingjie 
Published: February 2003

AbstractUnbound oxacillin concentrations in human serum albumin (HSA) solutions in the presence or absence of cefoperazone were determined using high‐performance frontal analysis coupled with chemiluminescence detection (HPFA‐CL). The HPFA was performed on an ISRP column with 67 mM potassium phosphate buffer of pH 7.4 and ionic strength of 0.17 as the mobile phase. The luminol–H2O2–Co2+ system was employed in the chemiluminescence detection. The detection was highly specific for oxacillin in the presence of cefoperazone. Although both drugs in HSA solutions co‐eluted in the same region in HPFA, cefoperazone did not interfere with the determination of unbound concentration of oxacillin. In the solution of 100 µM HSA and 11.33 µM oxacillin the bound percentage of oxacillin to HSA was estimated as 80.5%. Addition of 30.98 µM cefoperazone into the HSA‐equilibrated solution produced little effect on the protein binding of oxacillin. In the presence of 154.9 µM cefoperazone, however, the bound percentage of oxacillin was significantly reduced. This specific method could be applied to the investigation of drug‐drug interaction in protein binding. Copyright © 2003 John Wiley & Sons, Ltd.
Iron Twin‐Coronet Porphyrins as Models of Myoglobin and Hemoglobin: Amphibious Electrostatic Effects of Overhanging Hydroxyl Groups for Successful CO/O2 Discrimination
Authors: Tani Fumito , Matsu‐ura Mikiya , Ariyama Kiyoko , Setoyama Toshikazu , Shimada Takayuki , Kobayashi Shinjiro , Hayashi Takashi , Matsuo Takashi , Hisaeda Yoshio , Naruta Yoshinori 
Published: February 2003

AbstractInspired by the observation of polar interactions between CO and O2 ligands and the peptide residues at the active site of hemoglobin and myoglobin, we synthesized two kinds of superstructured porphyrins: TCP‐IM, which contains a linked imidazole ligand, and TCP‐PY, which contains a linked pyridine ligand, and examined the thermodynamic, kinetic, and spectroscopic (UV/Vis, IR, NMR, and resonance Raman) properties of their CO and O2 complexes. On both sides of each porphyrin plane, bulky binaphthyl bridges form hydrophobic cavities that are suitable for the binding of small molecules. In the proximal site, an imidazole or pyridine residue is covalently fixed and coordinates axially to the central iron atom. In the distal site, two naphtholic hydroxyl groups overhang toward the center above the heme. The CO affinities of TCPs are significantly lower than those of other heme models. In contrast, TCPs have moderate O2 binding ability. Compared with reported model hemes, the binding selectivity of O2 over CO in TCP‐IM and TCP‐PY complexes is greatly improved. The high O2 selectivity of the TCPs is mainly attributable to a low CO affinity. The comparison of kon(CO) values of TCPs with those of unhindered hemes indicates the absence of steric hindrance to the intrinsically linear CO coordination to FeII in TCP‐IM and TCP‐PY. The abnormally large koff(CO) values are responsible for the low CO affinities. In contrast, koff(O2) of TCP‐PY is smaller than those of other pyridine‐coordinated model hemes. For the CO adducts of TCPs, unusually low ν(FeCO) and unusually high ν(CO) frequencies are observed. These results can be ascribed to decreased back‐bonding from the iron atom to the bound CO. The lone pairs of the oxygen atoms of the hydroxyl groups prevent back‐bonding by exertion of a strong negative electrostatic interaction. On the other hand, high ν(FeO2) frequencies are observed for the O2 adducts of TCPs. In the resonance Raman (RR) spectrum of oxy‐TCP‐IM, we observed simultaneous enhancement of the FeO2 and OO stretching modes. Furthermore, direct evidence for hydrogen bonding between the hydroxyl groups and bound dioxygen was obtained by RR and IR spectroscopy. These spectroscopic data strongly suggest that O2 and CO binding to TCPs is controlled mainly by the two different electrostatic effects exerted by the overhanging OH groups: destabilization of CO binding by decreasing back‐bonding and stabilization of O2 binding by hydrogen bonding.
Swelling and Shrinking of Polyelectrolyte Microcapsules in Response to Changes in Temperature and Ionic Strength
Authors: Gao Changyou , Leporatti Stefano , Moya Sergio , Donath Edwin , Möhwald Helmuth 
Published: February 2003

AbstractSwelling and shrinking of polyelectrolyte microcapsules consisting of poly(styrene sulfonate, sodium salt) (PSS) and poly(diallyldimethyl ammonium) chloride (PDADMAC) multilayers have been observed in response to temperature and electrolyte exposure, respectively. Heat‐induced capsule swelling and capsule wall volume reduction were observed by confocal laser scanning microscopy (CLSM) and scanning force microscopy (SFM). On the other hand, pronounced shrinking in diameter induced by exposure to an electrolyte was observed in parallel to increases in the thickness of the capsule wall. The estimated wall volume was reduced to two thirds of the control for the salt‐exposed capsules and one half for the salt‐exposed and simultaneously annealed capsules. This reduction in volume was supposedly mainly caused by the compression of the capsule wall due to the ionic screening from the electrolyte. The highly porous microstructure of the multilayers and loosely bound PSS/PDADMAC complex are thought to be responsible for the structure of the PSS/PDADMAC capsules being easily modulated upon annealing and salt‐exposure.
Electrocatalytic Oxidation of Formic Acid at an Ordered Intermetallic PtBi Surface
Authors: Casado‐Rivera Emerilis , Gál Zoltán , Angelo A. C. D. , Lind Cora , DiSalvo Francis J. , Abruña Héctor D. 
Published: February 2003

AbstractThe electrocatalytic oxidation of formic acid at a PtBi ordered intermetallic electrode surface has been investigated using cyclic voltammetry, rotating disk electrode (RDE) voltammetry and differential electrochemical mass spectrometry (DEMS). The results are compared to those at a polycrystalline platinum electrode surface. The PtBi electrode exhibits superior properties when compared to polycrystalline platinum in terms of oxidation onset potential, current density, and a much diminished poisoning effect by CO. Using the RDE technique, a value of 1.4×10−4 cm s−1 was obtained for the heterogeneous charge transfer rate constant. The PtBi surface did not appear to be poisoned when exposed to a CO saturated solution for periods exceeding 0.5 h. The results for PtBi are discussed within the framework of the dual‐path mechanism for the electrocatalytic oxidation of formic acid, which involves formation of a reactive intermediate and a poisoning pathway.
AFM reveals steps in Mn‐Al silicates crystals obtained from melt
Authors: Nicolov M. F. , Woensdregt C. F. 
Published: February 2003

AbstractMn3AI2Si3O12 crystals were grown experimentally at atmospheric pressure and at temperatures 1235 °C from a molten stoichiometric mixture of tephroite (Mn2SiO4), γ‐alumina (A1203) and quartz (SiO2) Their habit is identical to that of natural grown Mn3AI2Si3O12 crystals. Using AFM (Atomic Force Mycroscopy) technique are shown the steps of growing crystals.
Crystal structure of 3‐hydroxy methyl 4,6‐dimethoxy‐9‐phenylsulfonyl‐carbazole
Authors: Govindasamy L. , Rajakannan V. , Velmurugan D. , Mohanakrishnan A. K. , Srinivasan P. C. 
Published: February 2003

AbstractThe crystal structure of 3‐Hydroxy methyl 4,6‐dimethoxy‐9‐phenylsulfonyl‐carbazole. (C21H19NO5S) has been determined [CCDC 194425]. The compound crystallizes from methanol in the monoclinic system, space group I2/c, with unit cell parameters: a = 20.498(2), b = 9.258(2), c = 21.866(3)Å, β = 116.450(10)°, Z = 8, V = 3715.2(10)Å3. The crystal structure was solved by direct methods and refined by full‐matrix least squares to a final R‐value of 0.050 with 3508 unique reflections. The planar carbazole ring fragment is inclined at an angle of 79.9(1)° to the phenylsulfonyl group. The sum of the angle about N is 351.6(2)°. The atoms linked to the central hexavalent S atom are arranged in a tetrahedral configuration with the larger deviations in the O‐SO angles [O1‐S‐O2 = 119.7(2)°] and the O1‐S‐N and O2‐S‐N angles [106.1(2) and 106.9(1)°, respectively].
Crystal structure of cis,cis,cis‐1,2‐epoxy‐3,5‐dibromo‐4‐hydroxy tetralin
Authors: Çelik I. , Demirtas I. , Akkurt M. , Erenler R. , Güven K. , Çakmak O. 
Published: February 2003

AbstractThe title compound, C10H8Br2O2, consists of a tetrahydronaphthalene skeleton composed of a six‐membered ring A with arene oxide, monobromo and monohydroxy atoms in cis,cis,cis configuration held in a boat conformation and a six‐membered planar ring B, where the ring B carries monobromo atom. The repulsive interactions between the Br and OH atoms affect the topology of the tetrahydronaphthalene moieties.
A new database for seed oil fatty acids — the database SOFA
Authors: Aitzetmüller Kurt , Matthäus Bertrand , Friedrich Holger 
Published: February 2003

AbstractIn a time of diminishing resources, a better knowledge of nature's biodiversity is important. The plant kingdom contains lipids with an astonishing variety of structures, particularly so in angiosperm seed oils. Lipids as natural products are an exciting field of research. Over many years, the Institute for Chemistry and Physics of Lipids in Münster has collected seed oil fatty acid composition data, which were sorted by plant botanical name. Although this collection contained numerous examples for the occurrence, distribution, and content of fatty acids with unusual structures in various concentrations, they could not be searched for manually. This data collection has now been transferred into an electronically searchable database, offering a variety of search routines. Currently it contains about 110, 000 individual data in 17, 500 sets, relating to more than 7, 000 different plant species. About 500 different fatty acids are listed. The database permits searches for plant species, genera and families, for individual fatty acids and combinations of fatty acids in their seed oils, and for their percentage contents in form of fatty acid composition tables. It also contains literature references and close to 1, 000 unpublished data from analyses carried out by GLC analysis between 1986 and 2002 in the Institute for Chemistry and Physics of Lipids. Most interestingly, fatty acid partial structures or functional groups can also be searched for, yielding the percentage contents of relevant fatty acids, using a specially developed “Delta‐Notation” system. The data on occurrence and distribution of unusual fatty acids in the plant kingdom will be useful in chemistry, botany, search for renewable resources, plant breeding, gene technology or gene transfer and indirectly also for enzyme design. A number of examples for “search” and find operations are given and may help to illustrate the usefulness of the new database.
Conicaquinones A and B, Two Novel Cytotoxic Terpene Quinones from the Mediterranean Ascidian Aplidium conicum
Authors: Aiello Anna , Fattorusso Ernesto , Luciano Paolo , Menna Marialuisa , Esposito Giuseppe , Iuvone Teresa , Pala David 
Published: February 2003

AbstractTwo new unique cytotoxic metabolites, conicaquinones A (1) and B (2), each possessing a 1,1‐dioxo‐1,4‐thiazine ring, were isolated from the Mediterranean ascidian Aplidium conicum. Their structures were established by an extensive spectroscopic analysis. Compounds 1 and 2 exhibited a strong cytotoxicity in vitro against rat glioma cells. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Copper Solid Amalgam Electrodes
Authors: Yosypchuk Bogdan , Novotný Ladislav 
Published: February 2003

AbstractThis work describes the behavior of copper solid amalgam electrodes (CuSAE). The applied potential range has been compared with that of the silver solid amalgam electrode (AgSAE) and the hanging mercury drop electrode (HMDE). In 0.05 M tetraborate buffer the applicable potential range of CuSAE is+0.945 V to −1.75 V excluding −0.2 V to −0.5 V, where the anodic oxidation of copper occurs. CuSAE does not need other than electrochemical pre‐treatment, which has been documented by the evaluated repeatability of eleven voltammetric curves of Cd2+ (0.1 ppm), Pb2+ (0.1 ppm) and Mn2+ (0.5 ppm). The obtained results showed that CuSAE could substitute the solid copper, amalgamed copper or liquid copper amalgam electrodes, and can be applied for the study of systems needing an addition of Cu2+ ions into the measured solution.
Self‐Assembled Monolayers into the 21st Century: Recent Advances and Applications
Authors: Gooding J. Justin , Mearns Freya , Yang Wenrong , Liu Jingquan 
Published: February 2003

AbstractThe modification of an interface on a molecular level with more than one molecular ‘building block' is essentially an example of the ‘bottom–up' fabrication principle of nanotechnology. The fabrication of such integrated molecular systems in electrochemistry has seen rapid progress in recent years via the development of sensing interfaces fabricated using self‐assembled monolayers (SAMs). This review outlines recent advances and applications of self‐assembled monolayers for modifying electrodes with an emphasis on the development of integrated molecular systems. First, some basic issues regarding fabricating integrated molecular systems, such as the role of the surface topography of the electrode and patterning surfaces, are discussed. Subsequently an overview of recent developments in pH, inorganic and bio sensing involving the use of SAMs is given. Finally emerging trends in using molecular building blocks in the fabrication of integrated molecular systems, such as nanotubes, dendrimers and nanoparticles, are reviewed.
The use of barium and strontium abundances in human skeletal tissues to determine their geographic origins
Authors: Burton J. H. , Price T. D. , Cahue L. , Wright L. E. 
Published: February 2003

AbstractDecades of research show that barium and strontium enter skeletal tissues in proportion to their dietary abundance and, hence, to local environmental levels. Among regions that contrast geologically or climatologically, the environmental abundance of these elements can vary substantially and exceed variation due solely to local dietary differences. Because dental enamel develops during childhood and retains the original levels of these elements, it can provide a chemical signature of the geographic origins of individuals. Copyright © 2003 John Wiley & Sons, Ltd.
Assessing the preservation of biogenic strontium in fossil bones and tooth enamel
Authors: Hoppe K. A. , Koch P. L. , Furutani T. T. 
Published: February 2003

AbstractAnalyses of the strontium isotope ratio (87Sr/86Sr) of vertebrate fossils can provide information about palaeobiological attributes such as habitat use and movement patterns. Diagenetic contaminants can alter the 87Sr/86Sr ratio of fossils, however, complicating palaeobiological interpretations. Several pretreatment protocols have been developed to separate diagenetic contaminants from biogenic Sr. While these methods can remove some diagenetic Sr, it has not been shown that any technique removes all contamination. The extent to which pretreatment removes diagenetic Sr can be quantified through analysis of the 87Sr/86Sr ratios of fossil marine mammal bones and teeth buried in sediments with non‐marine diagenetic 87Sr/86Sr signatures. To do this, we examined Holocene seals recovered from archaeological sites in Greenland and California, as well as a Miocene whale from Maryland. Our results demonstrate that although pretreatment eliminated some contaminants from bone, a large percentage (up to 80%) of diagenetic Sr remained after treatment. In contrast, pretreatment does appear to remove nearly all (≥∼95%) diagenetic Sr from tooth enamel. Copyright © 2003 John Wiley & Sons, Ltd.
Partitioning of unsaturated hydrophilic monomer in microemulsion media monitored by pyrene fluorescence method
Authors: Capek Ignac , Liaw Der‐Jang , Huang Ching‐Cheng 
Published: February 2003

AbstractThe extent of intra‐ and interchain associations of (un)charged water‐soluble monomers in the homogeneous and micellar solutions was studied with steady‐state fluorescence spectroscopy. Fluorescence spectroscopic experiments were performed on uncharged (acryl amide) and charged hydrophilic monomers [zwitterionic 3‐dimethyl(methacryloyloxyethyl)ammonium propane sulfonate (DMAPS), etc.] with pyrene as a probe. In both the homogeneous and micellar solutions, linear Stern–Volmer plots were obtained that implied that the quenching process can be considered as totally dynamic. The Stern–Volmer constant (KSV) for DMAPS decreased with an increasing dielectric constant of solvent and the concentration of simple electrolyte. An abrupt decrease in KSV was observed in the presence of a small amount of anionic emulsifier [below the critical micelle concentration (cmc)]. The dependence of KSV on pH for DMAPS was described by a curve with a maximum at about pH = 7. This was interpreted in terms of segregation of DMAPS and the variation of a optimal microenvironment for the probe and quencher with pH. The quenching rate in the micellar solutions strongly increased above the cmc but was lower than that in the homogeneous solutions. In the micellar solutions (above the cmc), the microenvironment for an interaction between the probe and quencher was suggested to be the whole microdroplet. The dependence of KSV on pH for DMAPS is described by a curve with a maximum at about pH = 9.3. The synergistic effect arises from the segregation of charged quencher molecules within the microdroplets. The complex (or strong interaction) between quencher and additive(s) is supposed to increase the dynamic nature of microdroplets that provides an optimal microenvironment for probe and quencher. A good coemulsifier, however, removes quencher from the interface and creates a barrier for entering monomer (quencher) into the core of micelles; therefore, quenching is depressed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 571–581, 2003
Dynamic, hard and strategic questions: using optimization to answer a marketing resource allocation question
Authors: Graham Alan K. , Ariza Carlos A. 
Published: February 2003

AbstractFor historical reasons, optimization has traditionally been slightly outside the mainstream of system dynamics. However, computer technology has made both quantitative data more abundant and optimization more feasible. At the same time, modelers are encountering real situations and clients with high‐stakes questions that are nearly impossible to answer without optimization—the systems involved are not only dynamic, and not only highly interconnected, but also combinatorially daunting. In particular, corporate marketers currently make allocation decisions impacting billions of dollars of shareholder value on the basis of intuitive “anchor and adjust” strategies, which can be far from optimal. This article presents an anonymized case study of one such situation. The company is in a high‐tech industry undergoing rapid change. The company needed to fashion a go‐to‐market strategy balancing traditional and unfamiliar markets, an important component of which was allocation of marketing resources. Optimization revealed a potential valuation increase of roughly 30 per cent relative to executives' intuitive allocations. Scenario analysis revealed the basic policy direction (more advertising) to be robust, and in the process resolved several traditional conundrums in dealing with adverse events in the marketplace. Copyright © 2003 John Wiley & Sons, Ltd.
Modeling biological systems using Dynetica—a simulator of dynamic networks
Authors: You Lingchong , Hoonlor Apirak , Yin John 
Published: February 2003

Abstract
Summary: We present Dynetica, a user-friendly simulator of dynamic networks for constructing, visualizing, and analyzing kinetic models of biological systems. In addition to generic reaction networks, Dynetica facilitates construction of models of genetic networks, where many reactions are gene expression and interactions among gene products. Further, it integrates the capability of conducting both deterministic and stochastic simulations.
Availability and supplementary information: Dynetica 1.0, example models, and the user's guide are available at http://www.its.caltech.edu/~you/Dynetica/Dynetica_page.htm
Contact: you@cheme.caltech.eduyin@engr.wisc.edu
* To whom correspondence should be addressed.