bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automatic detection and verification of solar features
Authors: Qahwaji R. , Colak T. 
Published: January 2006

AbstractA fast hybrid system for the automated detection and verification of active regions (plages) and filaments in solar images is presented in this paper. The system combines automated image processing with machine learning. The imaging part consists of five major stages. The solar disk is detected in the first stage, using a morphological hit‐miss transform, watershed transform and Filling algorithm. An image‐enhancement technique is introduced to remove the limb‐darkening effect and intensity filtering is implemented followed by a modified region‐growing technique to detect the regions of interest (RoI). The algorithms are tested on H‐α and CA II K3‐line solar images that are obtained from Meudon Observatory, covering the period from July 2, 2001 till August 4, 2001. The detection algorithm is fast and it achieves false acceptance rate (FAR) error rate of 67% and false rejection rate (FRR) error rate of 3% for active regions, and FAR error rate of 19% and FRR error rate of 14% for filaments, when compared with the manually detected filaments in the synoptic maps. The detection performance is enhanced further using a neural network (NN), which is trained on statistical features extracted from the RoI and non‐RoI. With the use of this combination the FAR has dropped to 2% for active regions and 4% for filaments.© 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 199–210, 2005
A system for matching moving vehicles across different camera sites in outdoor environments
Authors: Lao Y. , Leung C. H. , Hung Y. S. 
Published: January 2006

AbstractA method for identifying the same running vehicle from images captured at different camera sites is proposed. This is achieved through an image matching process. With cameras installed at the inlets and exits of highways and at crossroads in a road network, the system can be used for tracking the routes of individual vehicles and computing the times of traveling from one site to another. The system has the advantages of being low cost and not requiring sophisticated imaging hardware. Contributions include (i) a novel background removal method that employs the robust RANSAC algorithm for estimation, (ii) an elaborate shadow removal algorithm, and (iii) an effective license plate matching method applicable to poor quality images.© 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 211–219, 2005
Optimization and integration of high‐performance ground penetrating imaging radar system: A research prototype
Authors: Lee Michael , Ono Sashi 
Published: January 2006

AbstractThis paper reports the design, development, and field experimentation of a new ground penetrating imaging radar system. This research prototype unit features full system optimization, which successfully integrates the key components of antenna sensitivity, data‐acquisition waveforms, synthetic‐aperture scan, and image reconstruction algorithms, for optimal system performance.© 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 220–223, 2005
Warfarin resistance in a French strain of rats
Authors: Lasseur Romain , Longin‐Sauvageon Christiane , Videmann Bernadette , Billeret Mikaëline , Berny Philippe , Benoit Etienne 
Published: January 2006

AbstractA warfarin‐resistant strain and a warfarin‐susceptible strain of wild rats (Rattus norvegicus) maintained in enclosures of the National Veterinary School of Lyon (France) were studied to determine the mechanism of the resistance to anticoagulant rodenticides. A low vitamin K epoxide reductase (VKOR) activity has been reported for many resistant rat strains. As recently suggested, mutations in the vitamin K epoxide reductase subunit 1 (VKORC1) gene are the genetic basis of anticoagulant resistance in wild populations of rats from various locations in Europe. Here we report, for our strain, one of the seven described mutations (Tyr139Phe) for VKORC1 in rats. In addition, a low expression of mRNA encoding VKORC1 gene is observed in resistant rats, which could explain their low VKOR activity. We calculated kinetic parameters of VKOR in the warfarin‐resistant and warfarin‐susceptible rats. The Vmax and the Km of the VKOR obtained in resistant rats were lowered by 57 and 77%, respectively, compared to those obtained in susceptible rats. As a consequence, the enzymatic efficiency (Vm/Km) of the VKOR was similar between resistant and susceptible rats. This result could be a good explanation to the observation that no clinical signs of vitamin K deficiency was observed in the warfarin‐resistant strain, while a low VKOR activity was found. VKOR activity in warfarin‐resistant rats was poorly inhibited by warfarin (Ki for warfarin is 29 μM and 0.72 μM for resistant and susceptible rats, respectively). © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:379‐385, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20104
Chemopreventive activity of selenocysteine prodrugs against tobacco‐derived nitrosamine (NNK) induced lung tumors in the A/J mouse
Authors: Li Liang , Xie Yang , El‐Sayed Wael M. , Szakacs Juliana G. , Franklin Michael R. , Roberts Jeanette C. 
Published: January 2006

AbstractProdrugs of L‐selenocysteine have potential utility in cancer chemoprevention. This study reports the efficacy of three selenazolidine‐4(R)‐carboxylic acids, (2‐unsubstituted, 2‐oxo, and 2‐methyl derivatives; SCA, OSCA, and MSCA, respectively) against tobacco‐related lung tumorigenesis in a mouse model. Seven days after initiation of an AIN‐76A diet supplemented with sodium selenite (5 ppm Se), L‐selenomethionine (3.75 ppm Se), Se‐methyl‐L‐selenocysteine (3 ppm Se), L‐selenocystine (15 ppm Se), SCA (15 ppm Se), OSCA (15 ppm Se), or MSCA (15 ppm Se), mice received 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone (NNK; 10 μmol, i.p.). After an additional 16 weeks on the diets, two compounds, OSCA and selenocystine, significantly reduced lung adenoma multiplicity from 7.2 tumors per mouse in the NNK group to 4.5 and 4.6 tumors per mouse, respectively. Neither selenium concentration nor glutathione peroxidase activity in either RBCs or liver served as surrogate indicators of tumor reduction. Hepatic selenium levels were significantly elevated by all selenium‐containing compounds except Se‐methyl‐L‐selenocysteine and SCA; RBC selenium levels by all except sodium selenite and MSCA. With the exception of L‐selenomethionine, RBC glutathione peroxidase activity was increased along with the elevated selenium levels. Hepatic glutathione peroxidase activity was elevated by all Se‐compounds except SCA. The two compounds showing significant tumor reduction (OSCA and selenocystine) were the only two compounds that showed ubiquity of changes, elevating both selenium levels and GPx activity in both liver and RBC. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:396‐405, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20105
New force field for calcium binding sites in annexin–membrane complexes
Authors: Merzel Franci , Hodošček Milan , Janežič Dušanka , Sanson Alain 
Published: January 2006

AbstractFor accurate classical molecular dynamics (MD) simulations of the calcium mediated bound complexes of annexin and membrane we have developed new force‐field parameters correctly describing the interaction of the Ca ion with its environment. We have used quantum chemical calculations to investigate the potential energy surface experienced by the Ca ion within the three different binding sites found in domain 1 of annexin V (ANX V/1). Based on these calculations we were able to quantify the charge polarization of atoms within the binding sites, and to determine the geometry and force constants of harmonic restraints between the Ca ion and its coordinating oxygen atoms. Harmonic restraints were introduced to compensate for the deviations between the quantum mechanical potential energy surface and that of the classical force field. Our analysis has shown that using the refined force field for the Ca binding sites enables long‐time MD simulations that conserve the initial structure of ANX V/1 significantly better than MD simulations using the standard force field. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 446–452, 2006
Relativistic correlating basis sets for lanthanide atoms from Ce to Lu
Authors: Sekiya Masahiro , Noro Takeshi , Miyoshi Eisaku , Osanai You , Koga Toshikatsu 
Published: January 2006

AbstractContracted Gaussian‐type function (CGTF) sets for the description of the 4f subshell correlation and of the 6s and 5d subshell correlation are developed for lanthanide atoms from Ce to Yb. Also prepared are basis sets for the 5d orbitals, which are vacant in the ground states of most lanthanide atoms but are essential in molecular environments. In addition, correlating CGTF sets for the 4f subshell correlation are supplemented for the Lu atom. A segmented contraction scheme is employed for their compactness and efficiency. Contraction coefficients and exponents are determined by minimizing the deviation from accurate natural orbitals generated from configuration interaction calculations that include relativistic effects through the third‐order Douglas–Kroll approximation. All‐electron and model core potential calculations with the present correlating sets are performed on the ground state of the diatomic CeO molecule. The calculated spectroscopic constants are in good agreement with experimental values. © 2006 Wiley Periodicals, Inc. J Comput Chem 27:463–470, 2006
Characterization of host–guest complexes of cucurbit[n]uril (n = 6, 7) by electrospray ionization mass spectrometry
Authors: Osaka Issey , Kondou Masanobu , Selvapalam Narayanan , Samal Shashadhar , Kim Kimoon , Rekharsky Mikhail V. , Inoue Yoshihisa , Arakawa Ryuichi 
Published: January 2006

AbstractWhen an intramolecular cavity exists in a molecule, it can trap another chemical species to form a host–guest complex. We examine the formation of such an inclusion complex with cucurbit[n]uril (CBn, n = 6, 7) as the host to trap alkali metal or ammonium ions as the guest, by electrospray ionization mass spectrometry (ESI‐MS). The results show that the inclusion complexes are formed between the three‐dimensional cylinder of CBn hosts and the guest cations. Selectivity of the complex formation is dependent both on (1) ion–dipole interactions between the cylindrical portal of the CBn hosts and the guest cations and (2) the hydrophobic interactions at the inner cavity of CBn. Copyright © 2006 John Wiley & Sons, Ltd.
Reactions of a modified lysine with aldehydic and diketonic dicarbonyl compounds: an electrospray mass spectrometry structure/activity study
Authors: Saraiva Marco A. , Borges Carlos M. , Florêncio M. Helena 
Published: January 2006

AbstractThe phenomenon known as non‐enzymatic glycation is described as the reaction of reducing sugars with basic amino groups of proteins and nucleic acids, as well as with simple amines, without enzyme mediation. Non‐enzymatic model glycation reactions that make use of low‐molecular‐weight compounds make an important contribution in the elucidation of glicated processes in vitro and in vivo. Four α‐dicarbonyl compounds, aldehydic (glyoxal, methylglyoxal and phenylglyoxal) and ketonic (diacetyl), were reacted with the modified amino acid Nα‐acetyl‐L‐lysine (AcLys) in an attempt to establish structure/activity relationships for the reactivity of α‐dicarbonyls with the amine compound. Electrospray ionization mass spectrometry (ESI‐MS) combined with tandem mass spectrometry (MS/MS) and collision‐induced dissociation (CID) was used to identify and characterize reagents, intermediates and reaction products. The formation of dicarbonyl‐derived lysine dimers was observed exclusively. Especially, attention is drawn to alkyl‐ (asymmetrical dicarbonyl systems) and carboxyl‐ (glyoxal system) substituted imidazolium ions, at ring position 2.The main differences observed in the reactions studied were related to the reactivity with the diimine intermediate. This intermediate can react either with a non‐hydrated dicarbonyl molecule at the aldehydic carbonyl, or with a mono‐hydrated one at the ketonic carbonyl, particularly for asymmetrical dicarbonyls. For 2‐carboxyl‐substituted imidazolium ion (glyoxal reaction), besides the usual keto–enol rearrangement from the diol group, an alternative reaction pathway (proton abstraction) appears to contribute also for the imidazolium ring‐closure process. Moreover, the formation of imidazolium ring structures can depend on several factors, namely, the presence (or absence) of electron donor substituents at the formed diol, the degree of stability of the new electrophile generated and/or the equilibrium concentration of the non‐ and mono‐hydrated dicarbonyl forms in solution, the last being particularly important for asymmetrical dicarbonyls.The results reported reveal the complexity of reactivity as well as the diversity of imidazolium molecular structures. Copyright © 2006 John Wiley & Sons, Ltd.
Mass spectrometric characterization of lipid‐modified peptides for the analysis of acylated proteins
Authors: Hoffman Michael D. , Kast Juergen 
Published: January 2006

AbstractThe analysis of acylated proteins by mass spectrometry (MS) has largely been overshadowed in proteomics by the analysis of glycosylated and phosphorylated proteins; however, lipid modifications on proteins are proving to be of increasing importance in biomedical research. In order to identify the marker ions and/or neutral loss fragments that are produced upon collision‐induced dissociation, providing a means to identify the common lipid modifications on proteins, peptides containing an N‐terminally myristoylated glycine, a palmitoylated cysteine and a farnesylated cysteine were chemically synthesized. Matrix‐assisted laser desorption/ionization time‐of‐flight time‐of‐flight (MALDI‐TOF‐TOF), electrospray ionization quadrupole time‐of‐flight (ESI Q‐TOF), and electrospray ionization hybrid triple‐quadrupole/linear ion trap (ESI QqQLIT) mass spectrometers were used for the analysis. The peptide containing the N‐terminally myristoylated glycine, upon CID, produced the characteristic fragments a1 (240.4 Th) and b1 (268.4 Th) ions as well as a low‐intensity neutral loss of 210 Da (C14H26O). The peptides containing a farnesylated cysteine residue fragmented to produce a marker ion at a m/z of 205 Th (C15H25) as well as other intense farnesyl fragment ions, and a neutral loss of 204 Da (C15H24). The peptides containing a palmitoylated cysteine moiety generated neutral losses of 238 Da (C16H30O) and 272 Da (C16H32OS); however, no marker ions were produced. The neutral losses were more prominent in the MALDI‐TOF‐TOF spectra, whereas the marker ions were more abundant in the ESI QqQLIT and Q‐TOF mass spectra. Copyright © 2006 John Wiley & Sons, Ltd.
Collision‐induced dissociation studies of protonated ether—(H2O)n (n = 1–3) clusters
Authors: Goebbert Daniel J. , Chen Hao , Wenthold Paul G. 
Published: January 2006

AbstractWe have studied the protonated ether—(H2O)n (n = 1–3) complexes containing tetrahydrofuran, dimethyl, diethyl, dibutyl, and butylmethyl ethers using a flowing afterglow triple‐quadrupole mass spectrometer. Collision‐induced dissociation, CID, of all clusters with n = 1, 2 shows sequential water loss. The n = 3 cluster of dimethyl ether shows sequential water loss, while all other ether clusters display selective product formation. The CID spectra are interpreted based on known energetics, and theoretical studies of the dimethyl and diethyl ether systems. Copyright © 2006 John Wiley & Sons, Ltd.
Deuterium isotope effects observed during competitive binding chiral recognition electrospray ionization—mass spectrometry of cinchona alkaloid‐based systems
Authors: Schug Kevin A. , Maier Norbert M. , Lindner Wolfgang 
Published: January 2006

AbstractDeuterium isotope effects are reported for binding between tert‐butylcarbamoyl‐quinine/quinidine chiral selectors and isotopomeric quasienantiomers of N‐(3,5‐dinitrobenzoyl)leucine measured using electrospray ionization‐mass spectrometry (ESI‐MS) and competitive binding. Evaluation of mixtures of each selector with one labeled and one unlabeled enantiomeric selectand of identical configuration showed a significant difference in measured ion abundances of diastereomeric complexes between the selector and each selectand. It was found that in some cases, the complex containing the nondeuterated selectand was 15% more abundant than its deuterated counterpart. On the basis of an assessment of solution‐ and gas‐phase isotope effects reported in the literature, a series of control experiments were performed to study the origin of the effects. On the basis of these measurements, our preliminary conclusion is that the differing gas‐phase physicochemical nature of the deuterated versus nondeuterated selectand represents the strongest contribution to the observed effect in this chiral molecular recognition system. Copyright © 2006 John Wiley & Sons, Ltd.
Fragmentation and skeletal rearrangements of 2‐arylylamino‐5‐aryl‐1,3,4‐oxadiazoles and their noncovalent complexes with cobalt cation and cyclodextrin studied by mass spectrometry
Authors: Frański Rafał , Gierczyk Błażej , Schroeder Grzegorz 
Published: January 2006

AbstractMass spectrometric fragmentation pathways of title compounds were studied by electron ionization (EI) and electrospray ionization (ESI) as methods of ion generation. To explain the observed complex skeletal rearrangements, tandem mass spectrometry, accurate mass measurement and isotope labeling (compounds containing one 13C atom in oxadiazole ring) were used. Loss of CO, N2 and H atoms under EI conditions led to the formation of 9,10‐dihydroacridine‐type ions, loss of NH3 under ESI conditions yielded the 4‐phenylphthalazinone‐type ions and the loss of HNCO under ESI conditions produced N‐arylamino‐benzonitrilium ions; however, this process can be affected by the electron‐donor/electron‐withdrawing properties of groups substituted at the phenyl rings. The ESI was used to study the complexes of the compounds with cobalt as well as with cyclodextrin. It was found that the compounds studied tend to form inclusion complexes with cyclodextrin of stoichiometry 1 : 1 and complexes of different stoichiometries with cobalt, although those of stoichiometry 6 : 1 and 4 : 1 are favored and the attachment of counter ion may stabilize the complexes 3 : 1 and 2 : 1. Copyright © 2006 John Wiley & Sons, Ltd.
Raman and IR spectral studies of L‐phenylalanine L‐phenylalaninium dihydrogenphosphate and DL‐phenylalaninium dihydrogenphosphate
Authors: Ravikumar B. , Rajaram R. K. , Ramakrishnan V. 
Published: January 2006

AbstractThe infrared (IR) and Raman spectra were recorded at room temperature for L‐phenylalanine, L‐phenylalaninium dihydrogenphosphate, and DL‐phenylalaninium dihydrogenphosphate, and the observed bands were assigned. In the first compound, a phenylalaninium cation and a zwitterionic L‐phenylalanine and in the latter compound two protonated DL‐phenylalaninium cations have been identified. Presence of NH···O and OH···O hydrogen bonds are revealed from the spectra. The symmetry of the dihydrogenphosphate anion is found to be retaining C2v symmetry in both crystals. Copyright © 2006 John Wiley & Sons, Ltd.
A novel ‘optimal’ exponential‐based integration algorithm for von‐Mises plasticity with linear hardening: Theoretical analysis on yield consistency, accuracy, convergence and numerical investigations
Authors: Artioli E. , Auricchio F. , Beirão da Veiga L. 
Published: January 2006

AbstractIn this communication we propose a new exponential‐based integration algorithm for associative von‐Mises plasticity with linear isotropic and kinematic hardening, which follows the ones presented by the authors in previous papers. In the first part of the work we develop a theoretical analysis on the numerical properties of the developed exponential‐based schemes and, in particular, we address the yield consistency, exactness under proportional loading, accuracy and stability of the methods. In the second part of the contribution, we show a detailed numerical comparison between the new exponential‐based method and two classical radial return map methods, based on backward Euler and midpoint integration rules, respectively. The developed tests include pointwise stress–strain loading histories, iso‐error maps and global boundary value problems. The theoretical and numerical results reveal the optimal properties of the proposed scheme. Copyright © 2006 John Wiley & Sons, Ltd.
Childhood acute lymphoblastic leukaemia in relation to population mixing around the time of birth in South Hungary
Authors: Nyári Tibor A. , Kajtár Pál , Bartyik Katalin , Thurzó László , Parker Louise 
Published: January 2006

AbstractIn a retrospective epidemiological study of 481,984 live births in South Hungary, we investigated whether higher levels of population mixing around the time of birth is a risk factor for acute lymphoblastic leukemia (ALL) under age 5 years. Poisson regression was used to investigate the relationship between risk of ALL and the population‐mixing index based on the number of incomers in each county district for each year, standardized to have a range of 0–1. Among all children, the risk of ALL increased significantly with increasing population mixing around the time of birth (trend across the range of 0–1 RR = 2.1 95% CI: 1.02–4.44). This effect was more marked for boys (RR = 3.1 95% CI: 1.13–8.51), which supports a sex‐specific effect of exposures on risk of ALL. Pediatric Blood Cancer © 2006 Wiley‐Liss, Inc.
Long‐lasting partial remission by Interferon‐alpha treatment in a child with essential thrombocythemia
Authors: Szegedi István , Benkő Ilona , Merő Gabriella , Prinzinger Ágota , Kappelmayer János , Kiss Csongor 
Published: January 2006

AbstractEssential thrombocythemia (ET) is a clonal myeloproliferative disorder characterized by sustained thrombocytosis, isolated hyperplasia of megakaryocytic lineage, and association with thrombotic or bleeding episodes. It is extremely rare in childhood and frequently presents without evident clinical signs. We describe a 3‐year‐old girl with severe headache and dizziness suffering from ET, who was treated with Interferon‐alpha‐2a (IFN) based on the potent effect of this agent to inhibit myeloid colonies induced by phytohemagglutinin A stimulated leukocyte conditioned medium (PHA‐LCM). Bone‐marrow‐derived mononuclear cells of this patient did not exhibit spontaneous colony formation but responded to recombinant human (rh) erythropoietin (EPO), rh granulocyte‐colony stimulating factor (G‐CSF), granulocyte‐macrophage (GM)‐CSF, and stem‐cell factor in addition to PHA‐LCM. After 65 months of in vivo IFN treatment, the patient experienced a sustained partial remission with platelet counts varying between 400 and 600 × 103/µl. Pediatr Blood Cancer 2007;49:744–747. © 2006 Wiley‐Liss, Inc.