bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unique scanning capabilities of a new hybrid linear ion trap mass spectrometer (Q TRAP) used for high sensitivity proteomics applications
Authors: Le Blanc J. C. Yves , Hager James W. , Ilisiu A. M. Patricia , Hunter Christie , Zhong Feng , Chu Ivan 
Published: June 2003

AbstractThe unique scanning capabilities of a hybrid linear ion trap (Q TRAP) mass spectrometer are described with an emphasis on proteomics applications. The combination of the very selective triple quadrupole based tandem mass spectrometry (MS/MS) scans with the very sensitive ion trap product ion scans allows rapid identification of peptides at low concentrations derived from post‐translationally modified proteins on chromatographic time scales. The Q TRAP instrument also offers the opportunity to conduct a variety of ion processing steps prior to performing a mass scan. For example, the enhancement of the multiple‐charge ion contents of the ion trap can be performed resulting in a survey mass spectrum dominated by double‐ and triple‐charge peptides. This facilitates the identification of relevant biological species in both separated and unseparated peptide mixtures for further MS/MS experiments.
Pulmonary glial heterotopia in a monoamniotic twin
Authors: Morgan Terry , Anderson Jodee , Jorden Michelle , Keller Kathy , Robinson Terry , Hintz Susan 
Published: June 2003

AbstractBrain heterotopia in the lungs is rare, but when it occurs in an otherwise healthy newborn, it presents a difficult diagnostic problem and uncertain pathophysiology. We report on a 2‐week‐old premature infant who presented with respiratory distress and widespread cystic lung changes identified by chest imaging studies. Autopsy demonstrated that the cyst walls were composed of well‐differentiated neuroglial tissue, which was confirmed by immunohistochemistry. The cysts were partially lined by bronchial epithelium and contained keratinous debris. For the first time, we demonstrate that the debris stain for human chorionic gonadotropin, compatible with aspirated amnion. There were no other congenital abnormalities. Her monoamniotic twin was anencephalic and died at birth. Although the etiology of glial heterotopia in the lungs is unknown, the majority of cases are associated with anencephalic newborns. Some authors postulated that this heterotopia may therefore be a consequence of fetal aspiration of brain tissue. Other possibilities include glial predominant teratomas, hamartomatous malformations, and abnormal neural crest migration. Our review of the 21 cases reported over the past century suggests that in utero aspiration of glial cells, or abnormal neural crest migration, are the most likely explanations for this rare and fatal disease. Pediatr Pulmonol. 2003; 36:162–166. © 2003 Wiley‐Liss, Inc.
Hypercapnic acidosis and compensated hypercapnia in control and pulmonary hypertensive piglets
Authors: Lee K. Jane , Hernandez Guillermo , Gordon John B. 
Published: June 2003

AbstractLow tidal volume/inspiratory pressure ventilator strategies result in hypercapnia, which has been shown to increase pulmonary vasomotor tone. This may be particularly detrimental in infants and children with preexistent pulmonary hypertension. In this study, a piglet model of chronic hypoxia‐induced pulmonary hypertension was used to test the hypotheses that: 1) the effects of hypercapnic acidosis are exaggerated by preexistent pulmonary hypertension; and 2) the pulmonary hemodynamic effects of hypercapnic acidosis are attenuated by normalizing pH. Pulmonary hypertension was induced by 2 weeks of hypoxia. Hemodynamic responses were measured in control and pulmonary hypertensive piglets during both normoxia and hypoxia under normocapnic, hypercapnic acidotic, and compensated hypercapnic conditions. We found that: 1) hypercapnic acidosis increased both normoxic and hypoxic pulmonary vascular resistance index (PVRI) in control piglets; 2) the pressor effects of hypercapnia were not attenuated by infusing bicarbonate to normalize the pH; and 3) piglets with chronic hypoxia‐induced pulmonary hypertension had elevated baseline normoxic and hypoxic PVRI, but responded to hypercapnic acidosis and compensated hypercapnia in a similar way to control piglets. These data suggest that acute hypercapnic acidosis may have deleterious effects on the pulmonary hemodynamics of normal and pulmonary hypertensive subjects which may not be acutely reversed by buffering the pH. Pediatr Pulmonol. 2003; 36:94–101. © 2003 Wiley‐Liss, Inc.
Smad6 is induced by BMP‐2 and modulates chondrocyte differentiation
Authors: Li Xeufeng , Ionescu Andreia M. , Schwarz Edward M. , Zhang Xinping , Drissi Hicham , Puzas J. Edward , Rosier Randy N. , Zuscik Michael J. , O'Keefe Regis J. 
Published: June 2003

AbstractBMPs regulate cartilage differentiation and have been approved for clinical use as stimulators of bone repair. BMP signaling is complex and there are multiple potential points of regulation, including modulation of Smad signaling, which is inhibited by both Smad6 and Smad7. In the current manuscript we assessed the expression and biological function of Smad6 during chondrocyte differentiation. We found that the induction of chondrocyte differentiation by BMP‐2 in chicken sternal embryonic chondrocytes was accompanied by a marked increase in Smad6 mRNA and protein levels. A morpholino antisense oligonucleotide complementary to Smad6 reduced the expression of Smad6 protein and enhanced the stimulatory effect of BMP‐2 on both colX and alkaline phosphatase activity. In contrast, over‐expression of Smad6 blocked BMP‐2 mediated induction of the type X collagen promoter, b2‐640 Luc. Therefore, expression studies as well as gain and loss of function experiments suggest that Smad6 participates in an important negative feedback loop whereby BMP‐2 mediated effects on chondrocyte differentiation are reduced by induction of Smad6. Additional studies are required to determine the extent to which this pathway participates in pathologic processes involving cartilage. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Susceptibility to neuroleptic-induced parkinsonism—age and increased substantia nigra echogenicity as putative risk factors
Authors: Jabs Burkhard Emanuel , Bartsch Andreas Joachim , Pfuhlmann Bruno 
Published: June 2003

AbstractObjectivePatients treated by neuroleptics often develop neuroleptic-induced parkinsonism (NIP) to a varying extent. The reasons for this are discussed controversially in the literature. Previous transcranial sonography (TCS) findings of the substantia nigra (SN) in patients with idiopathic Parkinson’s disease suggest a correlation of echogenicity with nigrostriatal dysfunction.MethodsOne hundred psychiatric patients receiving neuroleptics were included. They underwent clinical examination for NIP (Simpson and Angus-scale) and, independently, TCS of the SN. History of smoking habits and medication were taken from the patient’s chart.ResultsWe found a significant positive association of the prevalence of NIP with age (P < 0.01) and the echogenic area of the SN (P < 0.05). Neither type nor dosage of the neuroleptics was found to have any significant impact on the occurrence of NIP. Smokers displayed lower prevalence of NIP (P < 0.05) and lower EPS scores (P < 0.01).ConclusionsThese findings suggest that age and increased size of SN echogenicity are possible risk factors for NIP. In contrast, smoking seems to have a certain protecting effect.
Determining species composition in mixed-species marks: an example from the New Zealand hoki (Macruronus novaezelandiae) fishery
Authors: O'Driscoll Richard L 
Published: June 2003

Abstract
A model-based method has been developed for partitioning acoustic backscatter from mixed-species marks. This method uses catch-composition data to partition the echo integral, but allows for differences in trawl catchability and acoustic vulnerability between species. It was applied to estimate the biomass of New Zealand hoki (Macruronus novaezelandiae) from trawl and acoustic surveys on the Chatham Rise and Campbell Plateau in 2001. Mixed-species layers containing up to 20 different species were present in both survey areas. A total of 224 bottom-trawl surveys (123 on Chatham Rise and 101 on Campbell Plateau) were carried out to determine the species composition and relative densities. Simultaneous acoustic recordings made during each of these trawls were used to estimate vulnerability ratios for the two methods, i.e. acoustic as opposed to trawl surveys, (acoustic:trawl) by non-negative, least-squares minimization. The best-fit model for each survey attributed 14–22% of the backscatter in mixed layers within 10 m of the bottom to hoki. This produced hoki biomass estimates 1.3–1.8 times higher than the standard approach, which divides the echo integral in proportion to the catch assuming equal trawl catchability. The precision of the estimated acoustic:trawl vulnerability ratios depended on the contrast in trawl catch composition, and the ratios for the same species differed between areas. A major problem on the Chatham Rise was the acoustic contribution of small mesopelagic species, which are not caught by the bottom trawl. Despite these difficulties, the model-based approach has good potential for determining the biomass of the target species in a mixed-species mark when the different species cannot be discriminated acoustically.
Autonomous underwater vehicles: future platforms for fisheries acoustics
Authors: Fernandes Paul G , Stevenson Pete , Brierley Andrew S , Armstrong Frederick , Simmonds E.John 
Published: June 2003

Abstract
Autonomous underwater vehicles (AUVs) are unmanned submersibles that can be pre-programmed to navigate in three dimensions under water. The technological advances required for reliable deployment, mission control, performance, and recovery of AUVs have developed considerably over the past 10 years. Currently, there are several vehicles operating successfully in the offshore industries as well as in the applied and academic oceanographic sciences. This article reviews the application of AUVs to fisheries- and plankton-acoustics research. Specifications of the main AUVs currently in operation are given. Compared to traditional platforms for acoustic instruments, AUVs can sample previously impenetrable environments such as the sea surface, the deep sea, and under-sea ice. Furthermore, AUVs are typically small, quiet, and have the potential to operate at low cost and be unconstrained by the vagaries of weather. Examples of how these traits may be utilized in fisheries-acoustics science are given with reference to previous work in the North Sea and Southern Ocean and to potential future applications. Concurrent advances in multi-beam sonar technology and species identification, using multi-frequency and broadband sonars, will further enhance the utility of AUVs for fisheries acoustics. However, before many of the more prospective applications can be accomplished, advances in power-source technology are required to increase the range of operation. The paper ends by considering developments that may turn AUVs from objects sometimes perceived as science fiction into instruments used routinely to gather scientific facts.
Competing supplies of olive oil in the German market: An application of multinomial logit models
Authors: Ward Ronald W. , Briz Julian , de Felipe Isabel 
Published: June 2003

AbstractGermany consumers are shown to differentiate their use of olive oil by country‐of‐origin, with Spain, Italy, and Greece being important competing suppliers. Effects of demographics, product characteristics, and information sources impact the probability of buying olive oil by origin. Multinomial logit models are estimated and used to show the gains (or loses), and point to the important role of promotions to Spain's olive oil. The importance of these variables are ranked for each country and Odds Ratios are used to compare the relatives gains among the major suppliers. [EconLit citations: Q130, Q180]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 393–406, 2003.
Mechanical, hygroscopic, and thermal properties of ultrathin polymeric substrates for magnetic tapes
Authors: Ma Tiejun , Bhushan Bharat 
Published: June 2003

AbstractMechanical, hygroscopic, and thermal properties of improved ultrathin polymeric films for magnetic tapes are presented. These films include poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), and aromatic polyamide (ARAMID). PET films are currently the most commonly used polymeric substrate material for magnetic tapes, followed by PEN and ARAMID. The thickness of the films ranges from 6.2 to 4.8 μm. Tensile tests were run to obtain the Young's modulus, F5 value, strain at yield, breaking strength, and strain at break. The storage modulus, E′, and the loss tangent, tan δ, were measured using a dynamic mechanical analyzer (DMA) at temperature ranges of −50 to 150°C (for PET) and −50 to 210°C (for PEN and ARAMID) and at a frequency range of 0.016–28 Hz. Frequency–temperature superposition was used to predict the dynamic mechanical behavior of the films over a 28‐decade frequency range. Short‐term longitudinal creep behavior of the films during 10, 30, 60, and 300 s, 7 MPa, were measured at 25 and 55°C. Long‐term longitudinal creep measurements were performed at 25, 40, and 55°C for 100 h. The Poisson's ratio and 50‐h long‐term lateral creep were measured at 25°C/15% RH, 25°C/50% RH, 25°C/80% RH, and 40°C/50% RH. The in‐plane coefficient of hygroscopic expansion (CHE) at 25°C/20–80% RH and the coefficient of thermal expansion (CTE) at 30–70°C were measured for all the samples. The properties for all films are summarized. The relationship between the polymeric structure and the mechanical and physical properties are discussed, based on the molecular structure, crystallinity, and molecular orientation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3052–3080, 2003
Nanofiber‐reinforced polymers prepared by fused deposition modeling
Authors: Shofner M. L. , Lozano K. , Rodríguez‐Macías F. J. , Barrera E. V. 
Published: June 2003

AbstractVapor‐grown carbon fibers (VGCFs), a practical model nanofiber for single‐walled carbon nanotubes, were combined with an acrylonitrile–butadiene–styrene (ABS) copolymer to create a composite material for use with fused deposition modeling (FDM). Continuous filament feedstock materials were extruded from Banbury mixed composites with a maximum composition of 10 wt % nanofibers. Issues of dispersion, porosity, and fiber alignment were studied. SEM images indicated that the VGCFs were well dispersed and evenly distributed in the matrix and that no porosity existed in the composite material following FDM processing. VGCFs aligned both in the filament feedstock and in the FDM traces suggested that nanofibers, in general, can be aligned through extrusion/shear processing. The feedstock materials were processed into test specimens for mechanical property comparisons with unfilled ABS. The VGCF‐filled ABS swelled less than did the plain ABS at similar processing conditions due to the increased stiffness. The tensile strength and modulus of the VGCF‐filled ABS increased an average of 39 and 60%, respectively, over the unfilled ABS. Storage modulus measurements from dynamic mechanical analysis indicated that the stiffness increased 68%. The fracture behavior of the composite material indicated that the VGCFs act as restrictions to the chain mobility of the polymer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3081–3090, 2003
Easy approach to chiral Michael adducts by Eu+3‐catalyzed conjugate addition
Authors: De Rosa Margherita , Palombi Laura , Acocella Maria Rosaria , Fruilo Marina , Villano Rosaria , Soriente Annunziata , Scettri Arrigo 
Published: June 2003

AbstractMichael addition of enantiopure N‐acetoacetyl‐oxazolidin‐2‐ones is shown to take place in the presence of catalytic amounts of Eu+3 salts and complexes in high yields, very reduced reaction times, and moderate diastereoselectivity. The level of diastereoselectivity can be significantly enhanced by the suitable exploitation of the easy epimerization of the adducts in the presence of silica gel. Chirality 15:579–583, 2003. © 2003 Wiley‐Liss, Inc.
Iron chelation promoted by desazadesferrithiocin analogs: An enantioselective barrier
Authors: Bergeron Raymond J. , Wiegand Jan , Weimar William R. , McManis James S. , Smith Richard E. , Abboud Khalil A. 
Published: June 2003

AbstractFor patients who require lifelong blood transfusions, there is no efficient means, unless chelation therapy is employed, for elimination of excess iron. Alternatives to desferrioxamine, the currently accepted treatment for transfusional iron overload, are being investigated. The current article focuses on an enantiomeric pair of analogs of desferrithiocin, (+)‐(S)‐ and (−)‐(R)‐2‐(2,4‐dihydroxyphenyl)‐4,5‐dihydro‐4‐methyl‐4‐thiazolecarboxylic acid (4′‐hydroxydesazadesferrithiocin). The crystal structure corroborated the absolute configuration of the two compounds, (+) and (−) for the (S)‐ and (R)‐enantiomers, respectively. Job's plots established the tridentate nature of both analogs and circular dichroism spectra confirmed the ligands' antipodal relationship. (+)‐(S)‐4′‐Hydroxydesazadesferrithiocin is a more efficient deferration agent than is the (−)‐(R)‐enantiomer in a Cebus apella model of iron overload. Pharmacokinetic analyses and IC50 measurements in L1210 murine leukemia cells were undertaken in an effort to account for the contrast in efficacy between the two enantiomers. Some differences exist in the plasma pharmacokinetic parameters between the two analogs. However, a more plausible explanation may be the apparent differences in transport across the cell membrane; the IC50 value in L1210 cells of the (+)‐(S)‐enantiomer was at least 5‐fold lower than that of the (−)‐(R)‐compound. Chirality 15:593–599, 2003. © 2003 Wiley‐Liss, Inc.
Exciton coupling effects and conformational change of perhexyloligosilanes with optically active methyl(1‐naphthyl)phenylsilyl terminals
Authors: Oh Hyun‐Shik , Park Lee‐Soon , Kawakami Yusuke 
Published: June 2003

AbstractPerhexyloligosilanes (R,R)‐(+)‐MeNpPhSi*(Hex2Si)nSi*PhNpMe (n = 2; (R,R)‐(+)‐4a, n = 4; (R,R)‐(+)‐6a, n = 6; (R,R)‐(+)‐8a) with chiral methyl(1‐naphthyl)phenylsilyl terminals were synthesized and characterized. The absorption wavelengths λmax by 1La,Ph transition of phenyl chromophore conjugated with oligosilane units in (R,R)‐(+)‐4a – (R,R)‐(+)‐8a show bathochromic shift of about 3–4 nm compared with those of the α,ω‐phenyl substituted perhexyloligosilanes Ph(Hex2Si)mPh (m = 4; 4b, m = 6; 6b, m = 8; 8b) having the same silicon chain length. Longer chain length induces the separated λmax of 1La,Ph from 1Bb,Np of naphthyl chromophore with positive exciton chiralities. In (R,R)‐(+)‐8a, although the extremum wavelengths λext of exciton coupling between 1Bb,Np and 1La,Ph are separated by about 80 nm, the compound retains the positive exciton chirality, which provides definite information on the absolute configuration of terminal chiral silicon atoms. Bulky terminal substituents and lowering the temperature affect the conformation of the main chain, inducing extended silicon backbone structure. Chirality 15:646–653, 2003. © 2003 Wiley‐Liss, Inc.
Surface charge analysis in eddy current problems
Authors: Fujishima Yasushi , Wakao Shinji 
Published: June 2003

AbstractTo estimate the characteristics of electric machines that have conductors of complicated shape, it is effective to analyze the surface charge related to eddy current phenomena. However, the eddy current field is generally treated as a quasi‐static field in which the displacement current is neglected and the electric field is not defined in the nonconductive region in the calculation process. Therefore, when we use only the A–ϕ finite element method (FEM) as a field analysis method, it is difficult to calculate the surface charge directly at the interface between conductive and nonconductive regions. In this paper, with this background, we propose a novel method of analysis of the surface charge based on both the A–ϕ FEM with edge elements and the integral equation. This approach enables us to precisely calculate the surface charge. Some numerical results that demonstrate the validity of the proposed method are also presented, such as the surface charge analysis of linear induction motors for evaluating the relationships among the surface charge, eddy current, and conductor shape. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(1): 59–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10173
A novel technique to implement frequency hopping planar antennas with a computer interface
Authors: Majumder A. , Chakravarty T. , Saran S. , Sanyal S. K. 
Published: June 2003

AbstractIn this paper, a novel configuration for a computer‐controlled frequency hopping microstrip antenna is presented. A circular microstrip antenna, loaded with a series LC tuned circuit in the form of a varactor diode with a metallic pin, is electronically tuned by sending digital words using the asynchronous serial communication facility of a computer. An analytical formulation, useful for the design of such an antenna, is presented. A computer interface circuit has been developed which, unlike embedded systems, offers flexibility in the choice of hopping sequence and facilitates remote operation. Design details and measured results are given. The results illustrate the feasibility of the proposed scheme to convert a low‐profile antenna into an adaptive antenna system. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 270–274, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11035
Verilog‐A implementation of a 2D spatiotemporal VCSEL model for system‐oriented simulations of optical links
Authors: Christen T. , Odermatt S. , Jungo M. , Erni D. , Baechtold W. 
Published: June 2003

AbstractAn implementation of a highly efficient spatiotemporal vertical‐cavity surface‐emitting laser (VCSEL) model in the circuit simulation environment of Cadence is presented. The VCSEL model, based on a set of modified rate equations, is written in Verilog‐A. It enables the association of the VCSEL model with transistor‐level models of the driver and detector circuits. Furthermore, the spatiotemporal nature of the model allows the generation of multimode responses and corresponding far‐field intensity profiles, which can be used to investigate fibre coupling and propagation mechanisms. An optimization of the VCSEL drive signal performed using the built‐in optimizer of Cadence is presented. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 304–308, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11044
An improved compact 2D full‐wave FDFD method for general guided wave structures
Authors: Pereda José A. , Vegas Angel , Prieto Andrés 
Published: June 2003

AbstractRecently a finite‐difference frequency‐domain (FDFD) formulation has been reported for the dispersion analysis of uniform waveguides loaded with anisotropic dielectrics characterized by a diagonal tensor [4]. This formulation, which leads to an eigenvalue problem for the propagation constant γ, involves four field components. This paper shows that this formulation can be improved by taking advantage of the fact that the structures considered are strictly bidirectional waveguides and thus the dispersion analysis problem can be formulated as an eigenvalue problem for γ2, involving only two field components. This improved formulation is applied to several waveguiding structures and a comparison of the results with those obtained by the commercial simulator Agilent‐HFSS 5.6 show good agreement. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 331–335, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11052