bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasticity of muscle fibre number in seawater stages of Atlantic salmon in response to photoperiod manipulation
Authors: Johnston Ian A. , Manthri Sujatha , Smart Alisdair , Campbell Patrick , Nickell David , Alderson Richard
Published: August 2003

Atlantic salmon (Salmo salar L.) were fed to satiety and reared from ∼60 g to 5000 g at ambient seawater temperatures. The effect of photoperiod manipulation on muscle growth was investigated from the start of the first sea winter. Continuous light treatment in winter/spring (1 November to 18 June) improved growth performance in fish, resulting in a 30% increase in mean body mass relative to the ambient photoperiod fish by 12 August, but had no effect on sexual maturation. Significant increases in body mass in the continuous light groups were observed after 126 days (P<0.01). The number of fast muscle fibres per trunk cross-section was determined in a subset of the fish and was 28.5% higher in the continuous light(799×103) than the natural day length(644×103) groups after only 40 days, corresponding to the period of decreasing natural day length. Subsequent rates of fibre recruitment were similar between treatments. At the end of the fibre recruitment phase of growth (combined June and August samples), the maximum number of fast muscle fibres was 23% higher in fish from the cages receiving continuous light(881×103±32×103; N=19) than in the ambient photoperiod cages(717×103±15×103; N=20)(P<0.001). Continuous light treatment was associated with a shift in the distribution of fibre diameters, reflecting the altered patterns of fibre recruitment. However, the mean rate of fibre hypertrophy showed no consistent difference between treatments. There was a linear relationship between the myonuclear content of isolated single fibres and fibre diameter. On average, there were 27% more myonuclei in 150 μm-diameter fibres in the continuous light (3118 myonuclei cm-1) than the ambient photoperiod(2448 myonuclei cm-1) fish. After 40 days, continuous light treatment resulted in a transient increase in the density of myogenic progenitor cells, identified using a c-met antibody, to a level 70% above that of fish exposed to natural light. It is suggested that short days inhibited the proliferation of myogenic progenitor cells and that this was overcome by transferring fish to continuous light, causing an increase in the number of times the myogenic precursor cells divided and/or a decrease in cell cycle time. The net increase in myogenic progenitor cells resulted in proportional increases in the number and myonuclear content of fibres. The subsequent hypertrophy of these additional fibres can explain the delayed increase in body mass observed with continuous light treatment.
Time course of the response of mitochondria from oxidative muscle during thermal acclimation of rainbow trout, Oncorhynchus mykiss
Authors: Bouchard Patrice , Guderley Helga
Published: August 2003

The time course of changes in the properties of mitochondria from oxidative muscle of rainbow trout was examined during warm (15°C) and cold (5°C)acclimation. Mitochondrial oxidative capacities showed a biphasic response during thermal acclimation: at a given assay temperature, capacities first increased and then decreased during warm acclimation and showed the inverse pattern during cold acclimation. This was most apparent for maximal rates of state 3 oxygen consumption expressed per mg mitochondrial protein. Rates expressed per nmol ADP-ATP translocase (ANT) showed this pattern during cold acclimation. A biphasic pattern was also apparent for state 4 and oligomycin-inhibited (state 4ol) rates of oxygen uptake expressed per mg protein. Changes in states 4 and 4ol were smaller during cold than warm acclimation. Warm acclimation reduced the proportion of cytochrome c oxidase and citrate synthase needed during mitochondrial substrate oxidation. Phospholipid concentrations per mg mitochondrial protein changed little with thermal acclimation. Mitochondrial properties changed more quickly during warm than cold acclimation. While the biochemical modifications during thermal acclimation may eventually compensate for the thermal change,compensation did not occur at its onset. Rather, the initial changes of mitochondrial oxidative capacity in response to temperature change accentuated the functional impact of the thermal change, and prolonged exposure to the new temperature was required to attain a degree of thermal compensation.
Intestinal water absorption through aquaporin 1 expressed in the apical membrane of mucosal epithelial cells in seawater-adapted Japanese eel
Authors: Aoki Mayumi , Kaneko Toyoji , Katoh Fumi , Hasegawa Sanae , Tsutsui Naoaki , Aida Katsumi
Published: August 2003

To elucidate the mechanisms associated with water absorption in the intestine, we compared drinking and intestinal water absorption in freshwater-and seawater-adapted Japanese eels, and investigated a possible involvement of aquaporin (AQP) in the absorption of water in the intestine. Seawater eels ingested more water than freshwater eels, the drinking rate being 0.02 ml kg-1 h-1 in fresh water and 0.82 ml kg-1h-1 in sea water. In intestinal sacs prepared from freshwater and seawater eels, water absorption increased in time- and hydrostatic pressure-dependent manners. The water absorption rates were greater in seawater sacs than in freshwater sacs, and also greater in the posterior intestine than in the anterior. In view of the enhanced water permeability in the intestine of seawater eel, we cloned two cDNAs encoding AQP from the seawater eel intestine, and identified two eel homologues (S-AQP and L-AQP) of mammalian AQP1. S-AQP and L-AQP possessed the same amino acid sequence, except that one amino acid was lacking in S-AQP and two amino acids were substituted. Eel AQP1 was expressed predominantly in the intestine, and the expression levels were higher in seawater eel than in freshwater eel. Immunocytochemical studies revealed intense AQP1 immunoreaction in the apical surface of columnar epithelial cells in seawater eel, in which the immunoreaction was stronger in the posterior intestine than in the anterior. In contrast, the immunoreaction was faint in the freshwater eel intestine. Preferential localization of AQP1 in the apical membrane of epithelial cells in the posterior intestine of seawater eel indicates that this region of the intestine is responsible for water absorption, and that AQP1 may act as a water entry site in the epithelial cells.
A marine diatom-derived aldehyde induces apoptosis in copepod and sea urchin embryos
Authors: Romano Giovanna , Russo Gian Luigi , Buttino Isabella , Ianora Adrianna , Miralto Antonio
Published: August 2003

The diatom-derived aldehyde 2-trans-4-trans-decadienal(DD) was tested as an apoptogenic inducer in both copepod and sea urchin embryos, using terminal-deoxynucleotidyl-transferase-mediated dUTP nick-end labelling (TUNEL), DNA fragmentation profiling (laddering) and an assay for caspase-3 activity. DD induced TUNEL positivity and DNA laddering, but not caspase-like activation, in copepod embryos spawned by females fed for 10-15 days the diatom diet Thalassiosira rotula Meunier (in vivo),or when newly spawned eggs were exposed for 1 h to 5 μg ml-1 DD(in vitro). To our knowledge, this is the first time that evidence for an apoptotic process in copepods has been obtained by cytochemical (TUNEL)and biochemical (DNA fragmentation) approaches. The absence of caspase-like activity in copepod embryos suggests that caspase-independent programmed cell death occurs in these organisms. In sea urchin embryos, DD induced apoptosis and also activated a caspase-3-like protease. The saturated aldehyde decanal induced apoptosis at higher concentrations and after a longer incubation period than DD, indicating that α,β-unsaturation of the molecule,coupled with the aldehyde group, is responsible for the greater biological activity of DD. Since diatoms are an important food source for marine herbivores such as copepods and sea urchins, these findings may help explain why unsaturated aldehydes often induce reproductive failure, with important ecological consequences at the population level.
Hormonal control of swimbladder sonic muscle dimorphism in the Lusitanian toadfish Halobatrachus didactylus
Authors: Modesto Teresa , Canário Adelino V. M.
Published: August 2003

The swimbladder and associated sonic muscle of the Lusitanian toadfish Halobatrachus didactylus increase in size throughout life and are,respectively, 25% and 30% larger in type I (nest-holder) males than females,which may generate sexual differences in sound production. Sexual dimorphism in swimbladder is also evident in the morphological features of sonic muscle fibers. During the breeding season, type I males have smaller myofibril contracting zones surrounded by larger sarcoplasm areas compared with females,possibly an adaptation to speed and fatigue resistance for the production of long mating calls. Type II (floater) males show characteristics that are intermediate, but statistically not significantly different, between type I males and females. Six weeks after castration and androgen (testosterone and 11-ketotestosterone) replacement in type I and type II males there were no alterations either in swimbladder mass or fiber morphology. However,17β-estradiol induced a significant decrease in swimbladder mass and sarcoplasm area/myofibril area ratio. Six months after castration there was a clear reduction in the seasonal swimbladder hypertrophy in males and induction of sonic fiber morphological characteristics that resemble those occurring in females (low sarcoplasm area/myofibril area ratio). These results suggest that testicular factors are required to initiate sonic muscle hypertrophy and type I sonic fiber phenotype in H. didactylus, but a specific involvement of androgens has not been completely clarified.
A hydrodynamic topographic map in the midbrain of goldfishCarassius auratus
Authors: Plachta Dennis T. T. , Hanke Wolf , Bleckmann Horst
Published: August 2003

Sensory systems often consist of several parallel pathways. Within each pathway, sensory information may be processed in topographically arranged maps or in maps derived by neuronal computation. Parallel pathways have so far not been described in the central lateral line system of teleost fish at levels higher than the medulla, and evidence for midbrain lateral line maps in fish is still weak. We found two classes of units with different response patterns in the central lateral line nucleus in the torus semicircularis of the goldfish Carassius auratus. Units of one class responded to a passing sphere and to the wake caused by that sphere with excitation. Units of the second class also responded to the moving sphere. However, these units did not respond to the wake behind the sphere. Hydrodynamic information received by class two units was topographically organized in the torus semicircularis of goldfish in that anterior body areas projected to rostral midbrain and posterior body areas to caudal midbrain. Units that responded only to the passing sphere were on average located more ventrally in the lateral TS than the units that responded exclusively to a vibrating sphere.
Waterborne iron acquisition by a freshwater teleost fish, zebrafishDanio rerio
Authors: Bury Nicolas R. , Grosell Martin
Published: August 2003

Waterborne iron accumulation by the gills of the zebrafish Danio rerio was assessed in ion-poor water. Branchial iron uptake, which comprises both the iron that has entered the gill cells and iron that is strongly bound to the epithelia, has high- and low-affinity components. At low nominal [Fe] (<40 nmol l-1) the high-affinity component demonstrated saturation kinetics, with an apparent Km of 5.9 nmol l-1 Fe and Vmax of 2.1 pmol g-1 h-1. Over a range of higher nominal [Fe] (40-200 nmol l-1), branchial uptake was linear. In the presence of 2μmol l-1 of the reducing agent dithiothreitol (DTT), branchial iron accumulation was significantly enhanced at [Fe]>15 nmol l-1. The proton pump inhibitor bafilomycin A significantly reduced iron uptake in the presence of DTT. On the basis of these observations we conclude that branchial iron uptake at low [Fe] shows characteristics similar to those of other iron-transporting epithelia, coupling an apical membrane ferric reductase to a Fe2+/H+ symporter. Zebrafish branchial iron transport at 18.6 nmol l-1 was inhibited by 200 nmol l-1 Cd2+. But, unlike other Fe2+/H+ symporters, iron uptake was not affected by other divalent metals (Co2+, Ni2+, Pb2+,Cu2+, Zn2+ and Mn2+). Zebrafish loaded with 59Fe from the water showed a loss of 7.9 pmol Fe g-1body mass over the first day and a further loss of 5.7 pmol Fe g-1body mass over the following 28 days. The depuration kinetics followed a two-component exponential model; for the short-lived component, t1/2=0.31 days, and for the long-lived component, t1/2=13.2 days. The daily iron loss by zebrafish can be compensated by iron uptake at exceedingly low water iron concentrations(uptake rate at 1.625 nmol l-1 Fe=0.425 pmol g-1h-1), demonstrating that uptake of iron from the water is potentially an important source of this nutritive metal in freshwater teleost fish.
An early role for theDrosophila melanogastermale seminal protein Acp36DE in female sperm storage
Authors: Qazi Margaret C. Bloch , Wolfner Mariana F.
Published: August 2003

Female sperm storage is an essential component of reproduction in many animals. In insects, female sperm storage affects fecundity, sperm competition/preference and receptivity to re-mating. Female sperm storage consists of several stages, including sperm entry into the sperm storage organs (SSOs), maintenance within the SSOs and exit from the SSOs. The Drosophila melanogaster male seminal protein Acp36DE is essential for female sperm storage. Acp36DE associates with sperm and localizes to specific regions of the female reproductive tract, including the SSOs. We determined the stage of sperm storage at which Acp36DE acts by comparing the timing of initial sperm entry into storage as well as the rates of sperm accumulation and release from the SSOs in the presence or absence of Acp36DE. Acp36DE accelerates sperm accumulation into storage but does not mediate the entry of the first sperm into storage. This finding also demonstrates that the initial stage of sperm storage consists of multiple steps. Acp36DE enters the SSOs before sperm, and its residence within the SSOs does not require sperm. We propose that once sperm storage has initiated, Acp36DE acts as a guidance factor helping subsequent sperm move into storage, a corral concentrating sperm around the SSO entrances and/or a trigger for responses within the female that accelerate storage of sperm.
Compactness of Linear Aggregation Controlled by Molecular Selective Binding of Bridged Bis(β-cyclodextrin)s
Authors: Liu Yu , Wang Hao , Zhang Heng-Yi , Wang Li-Hua , Song Yun
Published: August 2003

Studies on linear aggregation prepared by inclusion complexation of bridged bis(β-cyclodextrin)s and calix[4]arene derivatives provide a simple method to control linear aggregation compactness by molecular recognition.
Analysis of Metallo‐Supramolecular Systems Using Single‐Molecule Force Spectroscopy
Authors: Kudera M. , Eschbaumer C. , Gaub H.E. , Schubert U.S.
Published: August 2003

Single‐molecule force spectroscopy has been used for the investigation of the rupture behavior of individual metallo‐supramolecular systems. For this purpose, a specifically designed unsymmetrical α,ω‐functionalized poly(ethylene oxide) has been employed for mono‐termination with a terpyridine ligand and subsequently for the attachment onto atomic force microscopy (AFM) tips and microscope slide substrates. Metallo‐supramolecular complexes were formed by the use of ruthenium(III)–ruthenium(II) chemistry. Vertical stretching with the AFM cantilever ruptured the coordinative bonds. The rupture force of individual bisterpyridine ruthenium(II) complexes was determined to be 95 pN at a force loading rate of 1 nN s–1. Simultaneous rupturing of multiple parallel metallo‐supramolecular bonds was also observed. Monte Carlo simulations corroborated the experimental observations. The presented results lay the basis for the application of such metallo‐supramolecular systems in advanced functional nanomaterials.
The Origin of Green Emission in Polyfluorene‐Based Conjugated Polymers: On‐Chain Defect Fluorescence
Authors: Romaner L. , Pogantsch A. , Scandiucci de Freitas P. , Scherf U. , Gaal M. , Zojer E. , List E.J.W.
Published: August 2003

The low emission band at 2.2–2.3 eV in polyfluorene‐based conjugated materials is studied by various spectroscopic methods on defined copolymers of 9–9′‐difarnesyl‐fluorene with 9‐fluorenone, which can be seen as a model compound for degraded polyfluorenes. Absorption, electroluminescence, and photoluminescence in the film (temperature‐dependent) and solution (room temperature) reveal the optical properties of this low‐energy emission band emerging in polyfluorene‐type polymers upon degradation. All the experimental evidence presented yield direct evidence against excimer or aggregate formation as the primary source of the low‐energy emission band. Instead keto defect sites can be shown to be responsible for the emissive defect.
Well‐Defined Fullerene Nanowire Arrays
Authors: Guo Y.‐G. , Li C.‐J. , Wan L.‐J. , Chen D.‐M. , Wang C.‐R. , Bai C.‐L. , Wang Y.‐G.
Published: August 2003

Fullerene nanowire arrays with well‐defined size and length have been prepared by a controllable technique. Fullerene molecules such as C60 are introduced into the pores of anodic aluminum oxide (AAO) templates under a direct current (DC) electric field and polymerized in the pores. Structure analysis shows that the C60 nanowires are mainly polycrystalline, and a rhombohedral polymeric phase is observed in their vibration spectra. The electrical conductivity of so‐prepared nanowire arrays show a semiconducting behavior. The ability to fabricate the fullerene nanowire arrays with controlled structures represents an important step toward the development of chemical sensors and nanoscale electronic devices based on fullerenes.
General Synthesis of Single‐Crystal Tungstate Nanorods/Nanowires: A Facile, Low‐Temperature Solution Approach
Authors: Yu S.‐H. , Liu B. , Mo M.‐S. , Huang J.‐H. , Liu X.‐M. , Qian Y.‐T.
Published: August 2003

The general large‐scale synthesis of a family of single‐crystalline transition metal tungstate nanorods/nanowires is easily realized by a hydrothermal crystallization technique under mild conditions using cheap and simple inorganic salts as precursors. Uniform tungstate nanorods/nanowires such as MWO4 (M = Zn, Mn, Fe), Bi2WO6, Ag2WO4, and Ag2W2O7 with diameters of 20–40 nm, lengths of up to micrometers, and controlled aspect ratios can be readily obtained by hydrothermal transformation and recrystallization of amorphous particulates. This novel and efficient pathway toward various kinds of related low‐dimensional tungstate nanocrystals under mild conditions could open new opportunities for further investigating the novel properties of tungstate materials.
Fully Reversible Homogeneous and Heterogeneous Li Storage in RuO2 with High Capacity
Authors: Balaya P. , Li H. , Kienle L. , Maier J.
Published: August 2003

In this paper, we report that Li can be stored in RuO2 with an unusually high coulombic efficiency. The process involves three electrochemical steps: i) formation of a Ru/Li2O nanocomposite, ii) formation of a Li‐containing surface film, and iii) interfacial deposition of Li within the Ru/Li2O matrix. Corresponding to the storage of 5.6 mole of Li ions per mole of RuO2, a high capacity of 1130 mAh g–1 is achieved. Furthermore, virtually all inserted Li ions can be extracted, corresponding to a nearly 100 % coulombic efficiency at the first cycle. Achieving a complete reversibility for such a Li storage system through complex heterogeneous solid‐state electrochemical reactions is possible because of the formation of nanoscale Ru/Li2O during Li insertion and nano‐RuO2 during Li extraction, in addition to the favorable transport properties of RuO2 itself.
Powder‐Based Ceramic Meso‐ and Microscale Fabrication Processes
Authors: Heule M. , Vuillemin S. , Gauckler L.J.
Published: August 2003

Processing techniques are reviewed that allow the introduction of ceramic components made from powders into microelectromechanical systems (MEMS). Ceramics have several advantages over other materials also in microsystems, e.g., heat resistance, hardness, corrosion resistivity, or functional properties. The range of available materials in microfabrication technology is being increased beyond those deposited by thin‐film technology. Top–down approaches like mechanical and laser‐based direct writing processes, ink‐jet printing, microextrusion, and lithography‐based methods are presented. They are complemented by some more fundamental work in the field of bottom–up synthesis of micro‐ and nanoscaled ceramic materials.
Volume Contractions Induced by Crosslinking: A Novel Route to Nanoporous Polymer Films
Authors: Jeong U. , Ryu D.Y. , Kim J.K. , Kim D.H. , Russell T.P. , Hawker C.J.
Published: August 2003

Thin films of polystyrene‐block‐poly(methyl methacrylate)(PS‐b‐PMMA) are prepared in which the cylindrical PMMA microdomains are oriented normal to the substrate. When the PS block is crosslinked, pores with tailored diameters ranging from 3 nm to ∼ 8 nm, are generated at the center of PMMA microdomains (see Figure). The distance between the pores and their lateral distribution reflects that of the initial copolymer template.
Fabrication of Positively Patterned Conducting Polymer Microstructures via One‐Step Electrodeposition
Authors: Zhou F. , Chen M. , Liu W. , Liu J. , Liu Z. , Mu Z.
Published: August 2003

One‐step electrodeposition of pyrrole on octadecyltrichlorosilane‐ (OTS) patterned silicon wafers results in positively patterned polypyrrole (PPy) structures, i.e., PPy deposits on the OTS‐covered area. In contrast, negative patterns are obtained on an indium tin oxide surface. The Figure shows electrically isolated positive PPy microwires on a silicon wafer.
Room‐Temperature Synthesis of Aragonite Crystals at an Expanding Liquid–Liquid Interface in a Radial Hele–Shaw Cell
Authors: Rautaray D. , Banpurkar A. , Sainkar S.R. , Limaye A.V. , Pavaskar N.R. , Ogale S.B. , Sastry M.
Published: August 2003

Large quantities of extremely fine aragonite needles (see Figure, top image) have been synthesized at room temperature at an expanding liquid–liquid interface in a radial Hele–Shaw cell. By simple variation of the experimental conditions, hollow, cylindrical aragonite/calcite crystals (see Figure, bottom image) may also be obtained. It is believed that this method can be extended to other materials and nanostructures.
Enhancement of Photocatalytic and Electrochromic Properties of Electrochemically Fabricated Mesoporous WO3 Thin Films
Authors: Baeck S.‐H. , Choi K.‐S. , Jaramillo T.F. , Stucky G.D. , McFarland E.W.
Published: August 2003

Mesoporous WO3 films with a lamellar structure (see Figure) have been synthesized by electrodeposition using sodium dodecyl sulfate (SDS) as a templating agent. Compared to non‐porous WO3 prepared with isopropanol instead of SDS, lamellar phase mesoporous WO3 showed higher photocatalytic activity and greater current density for hydrogen intercalation, probably due to the larger surface area of mesoporous WO3 and more facile charge transport.
Enhanced Luminance of Blue Light‐Emitting Polymers by Blending with Hole‐Transporting Materials
Authors: Suh M.C. , Chin B.D. , Kim M.‐H. , Kang T.M. , Lee S.T.
Published: August 2003

Laser‐induced thermal imaging (LITI) has been used to pattern polymeric light‐emitting devices (see Figure). Most commercial light‐emitting polymers (LEPs) are not suitable for LITI because of strong cohesion within the LEP layer. To reduce this and achieve excellent image quality, transfer layers based on blends of LEPs and inert polymers were used. The introduction of amorphous hole‐transporting materials also enhanced the brightness of the devices.
Generation of Uniform Colloidal Assemblies in Soft Microfluidic Devices
Authors: Yi G.‐R. , Thorsen T. , Manoharan V.N. , Hwang M.‐J. , Jeon S.‐J. , Pine D.J. , Quake S.R. , Yang S.‐M.
Published: August 2003

A microfluidic device is used to generate uniform emulsion droplets containing monodisperse latex spheres at specific intervals by shearing off the tip of the incoming aqueous phase at the junction of two microfluidic channels (see Figure). The water‐in‐oil emulsions are converted to uniform colloidal assemblies of latex spheres by slowly removing water from the aqueous emulsion droplets.
Synthesis of TiSe2 Nanotubes/Nanowires
Authors: Chen J. , Tao Z.‐L. , Li S.‐L. , Fan X.‐B. , Chou S.‐L.
Published: August 2003

The family of layered metal dichalcogenide nanomaterials has been enlarged with the successful preparation of TiSe2 nanotubes/ nanowires (see Figure). A solid‐phase reaction is described and the characterization of the product—by X‐ray diffraction, scanning and transmission electron microscopy, and Raman measurements—detailed.
Determination of the Particle Size Distribution of Quantum Nanocrystals from Absorbance Spectra
Authors: Pesika N.S. , Stebe K.J. , Searson P.C.
Published: August 2003

The optical absorbance spectrum for a suspension of quantum particles with an arbitrary particle size distribution is determined by the electronic transition and the distribution of bandgaps in the system. It is demonstrated that the particle size distribution obtained for a suspension of ZnO quantum particles is in excellent agreement with the distribution obtained from transmission electron microscope images.
Self‐Assembly of Mesostructured Conjugated Poly(2,5‐thienylene ethynylene)/Silica Nanocomposites
Authors: McCaughey B. , Costello C. , Wang D. , Hampsey J.E. , Yang Z. , Li C. , Brinker C.J. , Lu Y.
Published: August 2003

Mesostructured conjugated polymer/silica nanocomposites have been synthesized via surfactant‐directed assembly of monomeric materials in silica followed by polymerization. This novel approach provides a general route for the synthesis of mesostructured conjugated polymer/inorganic nanocomposites. The Figure shows transmission electron microscopy images of the nanocomposite cubic mesostructure viewed from the [111] direction.
Phase Separation Micromolding—PSμM
Authors: Vogelaar L. , Barsema J.N. , van Rijn C.J.M. , Nijdam W. , Wessling M.
Published: August 2003

Microstructures from a broad spectrum of materials, ranging from polymers to ceramics and metals, can be fabricated by phase separation micromolding (PSμM), a generic microfabrication technique. PSμM offers the possibility to introduce porosity; the process benefits from intrinsic shrinkage, which facilitates the fabrication of completely open microstructures (see Figure), and also promotes defect‐free release of the microstructure.
How Do Polycrystalline Materials Deform Plastically?
Authors: Kalidindi S.R. , Bhattacharyya A. , Doherty R.D.
Published: August 2003

Orientation imaging microscopy (OIM) and modern crystal plasticity theory have been used to understand in a fundamental way how plastic deformation occurs in crystalline solids. The orientation and size of neighboring grains is shown to strongly influence the local deformation experienced by a given crystal. This can be reconciled using the principle of minimum energy dissipation. The Figure shows a sample of the data produced using OIM.
WO3 Sol–Gel Modified Ag Nanoparticle Arrays for Electrochemical Modulation of Surface Plasmon Resonance
Authors: Wang Z. , Chumanov G.
Published: August 2003

A simple plasmon‐based electro‐optical device has been realized by over‐coating an array of Ag nanoparticles with WO3 sol–gel layers. This treatment had the effect of stabilizing the Ag nanoparticle arrays to such an extent that they were capable of rapidly and reversibly modulating the transmittance of the electrode by switching its externally applied potential (see Figure).
The First Truly All‐Polymer Electrochromic Devices
Authors: Argun A.A. , Cirpan A. , Reynolds J.R.
Published: August 2003

Using poly(3,4‐ethylenedioxythiophene)–poly (styrene sulfonate) (PEDOT–PSS) as the transparent electrode material, all‐polymer‐based electrochromic devices (ECDs) have been constructed from only organic and polymeric components. In the picture shown, an absorption/transmissive‐type ECD maintained in its colored state is bent to demonstrate its flexibility.
Application of a Transparent Conductive Substrate with an Atomically Flat and Stepped Surface to Lateral Growth of an Organic Molecule: Vanadyl Phthalocyanine
Authors: Ohta H. , Kambayashi T. , Hirano M. , Hoshi H. , Ishikawa K. , Takezoe H. , Hosono H.
Published: August 2003

The lateral growth of an organic molecule on a transparent conductive substrate—important for molecular electronics—is demonstrated using vanadyl phthalocyanine (VOPc) on epitaxial indium tin oxide (ITO) film with an atomically flat and stepped surface. The occurrence of two‐dimensional lateral growth is proved by the heights of the square‐shaped domains of VOPc (see Figure) stacked parallel to the ITO substrate.
Photoresponsive Anisotropic Soft Solids: Liquid‐Crystalline Physical Gels Based on a Chiral Photochromic Gelator
Authors: Moriyama M. , Mizoshita N. , Yokota T. , Kishimoto K. , Kato T.
Published: August 2003

Photoinduced reversible structural changes of anisotropic physical gels are applied to re‐writable patterning (see Figure, a photo of a re‐writable pattern). The change between a nematic gel and a cholesteric gel via a cholesteric liquid‐crystalline sol state is induced by trans–cis photoisomerization of the azobenzene moieties in a chiral hydrogen‐bonded gelator blended with a nematic liquid crystal.
Assembly of 1D Nanostructures into Sub‐micrometer Diameter Fibrils with Controlled and Variable Length by Dielectrophoresis
Authors: Tang J. , Gao B. , Geng H. , Velev O.D. , Qin L.‐C. , Zhou O.
Published: August 2003

A dielectrophoresis method for manipulation, alignment, and assembly of 1D nanostructures is reported. Processed carbon nanotubes dispersed in water are assembled into micro‐electrodes and fibrils of variable and controllable length from ∼ 1 μm to over 1 cm (see Figure). The method allows of parallel fabrication, and the fibrils could find applications as probes for scanning probe microscopes, electrodes, and conducting wires.
Biocatalytic Route to Ascorbic Acid‐Modified Polymers for Free‐Radical Scavenging
Authors: Singh A. , Kaplan D.L.
Published: August 2003

Ascorbic acid functionalized polymers (see Figure) for free radical scavenging have been synthesized via a two step biocatalytic route. The ascorbic acid retained antioxidant activity, and this functional antioxidant on a polymer backbone has implications for consumer‐related applications like foods, pharmaceuticals, and personal care products.
Undoped Photorefractive Ferroelectric Liquid Crystal
Authors: Talarico M. , Barberio G. , Pucci D. , Ghedini M. , Golemme A.
Published: August 2003

Photorefractive chiral smectic A and C phases known to date are not intrinsically photoconducting, but contain a light sensitizer dissolved in the bulk. In this work, the first example of a single‐component smectic mesophase (structure shown in Figure) which exhibits photorefractive behavior without any doping is presented. It is also shown that the observed photorefractive performance is larger than that previously reported for doped systems.
Quasi‐Aligned Single‐Crystalline W18O49 Nanotubes and Nanowires
Authors: Li Y. , Bando Y. , Golberg D.
Published: August 2003

Quasi‐aligned W18O49 nanotubes and nanowires with single‐crystalline monoclinic structure were prepared via a physical vapor deposition process. The axes of the nanotubes and nanowires were aligned along the [010] direction. Field‐emission measurement revealed a threshold field of 6.2 V μm–1 for W18O49 nanowire films, indicating the prepared W18O49 nanowires are excellent field emitters.
Non‐Close‐Packed Artificial Opals
Authors: Fenollosa R. , Meseguer F.
Published: August 2003

Non‐close‐packed artificial opals consisting of face‐centered cubic arrays of spheres interconnected by tubular necks (see Figure and cover) have been obtained. The fabrication method and structural and optical properties are reported. Compared to their close‐packed counterparts, non‐close‐packed opals have: i) much higher porosity and ii) stronger optical scattering, which provokes more intense reflectance peaks caused by larger photonic gaps.
Control of Molecular Transport Through Stimuli‐Responsive Ordered Mesoporous Materials
Authors: Fu Q. , Rao G.V.R. , Ista L.K. , Wu Y. , Andrzejewski B.P. , Sklar L.A. , Ward T.L. , López G.P.
Published: August 2003

External and reversible control of the size and surface energy of the pores in mesoporous architectures has been achieved. The method involves modification of mesoporous silica by atom transfer radical polymerization of N‐isopropyl acrylamide (the precursor to a stimuli‐ responsive polymer). The resulting polymer‐grafted particles allow the adsorption and transport of molecular species to be dynamically controlled as illustrated in the Figure for the release of rhodamine 6G from the particles at 50 °C.
High Electron Mobility and Ambipolar Transport in Organic Thin‐Film Transistors Based on a π‐Stacking Quinoidal Terthiophene
Authors: Chesterfield R.J. , Newman C.R. , Pappenfus T.M. , Ewbank P.C. , Haukaas M.H. , Mann K.R. , Miller L.L. , Frisbie C.D.
Published: August 2003

Thin‐film transistors (TFTs) based on a new n‐channel organic semiconductor (DCMT; see Figure) are reported. An electron mobility as high as 0.2 cm2/V s was observed, as well as ambipolar TFT behavior. Variable temperature measurements reveal that electron conduction is activated, with a small activation energy of 35 ± 10 meV. These results demonstrate that quinoidal oligothiophenes are a promising new class of organic semiconductors for TFTs.
General Synthesis of Ordered Crystallized Metal Oxide Nanoarrays Replicated by Microwave‐Digested Mesoporous Silica
Authors: Tian B. , Liu X. , Yang H. , Xie S. , Yu C. , Tu B. , Zhao D.
Published: August 2003

Microwave‐digested (MWD) mesoporous materials are shown for the first time to be powerful hosts (templates) for the production of various crystalline metal oxide nanowire (the Figure shows a model) or nanosphere arrays via a simple impregnation and thermolysis synthesis. Some of the metal oxides (e.g., Co3O4) exhibit ordered structures on both meso‐ and atomic scales.
Near‐Infrared Electroluminescent Light‐Emitting Devices Based on Ethyne‐Bridged Porphyrin Fluorophores
Authors: Ostrowski J.C. , Susumu K. , Robinson M.R. , Therien M.J. , Bazan G.C.
Published: August 2003

The photoluminescence and electroluminescence of guest–host blends containing DD and DDD (see Figure) in the conjugated polymers polyvinylcarbazole (PVK) and poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) is described. It is shown that this class of long‐wavelength‐emitting porphyrin oligomer, is an excellent platform upon which to fabricate near‐infrared light‐emitting devices.
Photo‐Induced Orientation of a Film of Ladderlike Polysiloxane Bearing Dual Photoreactive Side Groups
Authors: Gu H.W. , Xie P. , Shen D.‐Y. , Fu P.‐F. , Zhang J.‐M. , Shen Z.‐R. , Tang Y.‐X. , Cui L. , Kong B. , Wei X.‐F. , Wu Q. , Bai F.‐L. , Zhang R.‐B.
Published: August 2003

A newly designed ladder‐like polysiloxane (LPS) containing dual photoreactive side groups has been synthesized for the purpose of generating high‐quality photo‐alignment layers with controllable pretilt angle (∼ 1–7°, see Figure and cover). Integrated spectroscopic methods of UV dichroism, surface‐enhanced Raman scattering (SERS), and FT‐IR are used together for the first time to elucidate the photo‐alignment mechanism and the real cause of the high pretilt angle.
A Genuine Quarter‐Filled Band Mott Insulator, (EDT‐TTF‐CONMe2)2AsF6: Where the Chemistry and Physics of Weak Intermolecular Interactions Act in Unison
Authors: Heuzé K. , Fourmigué M. , Batail P. , Coulon C. , Clérac R. , Canadell E. , Auban‐Senzier P. , Ravy S. , Jérome D.
Published: August 2003

C1 symmetry and C–H···O and C–H···O hydrogen‐bond donor/acceptor ability of the title phase π‐donor are expressed by a glide plane (a ± c/2 repetition), uniform stacks, and a band structure quarter‐filled with holes. Conductivity and spin susceptibility data demonstrate strong Mott localization at ambient pressure which is weakened at high pressure. These results show that the 1/4‐Umklapp scattering channel is efficient enough for localization in 1D, strongly correlated electron systems.
Adverse work outcomes and events attributed to asthma
Authors: Mancuso Carol A. , Rincon Melina , Charlson Mary E.
Published: August 2003

Background

Asthma is a chronic condition that has been linked to lower employment rates, job effectiveness, productivity and increased absenteeism. The objectives of this study were to assess the impact of asthma on work function, workplace events, and career.

Methods

One hundred ninety‐six patients in an urban practice completed standardized major and minor life events scales and rated whether adverse work events were caused by asthma.

Results

Thirty‐eight percent of the patients had either changed jobs, work hours, or work duties, and 65% had taken days off because of asthma. In multivariate analyses, less education, not wanting to work, more comorbidity, prior use of oral corticosteroids, and current use of oral beta agonists and methylxanthines (P ≤ 0.05 for all comparisons) were associated with these outcomes. Also, currently working patients were more likely to be using inhaled corticosteroids (P = 0.018). Thirty‐nine percent believed asthma had adversely affected their career by causing them to: not pursue a desired career; not get promoted due to absenteeism; change to a worse job; and be perceived as incapable of more responsible assignments. Seven percent had a negative work event in the preceding year that they attributed to asthma, including job loss and unfavorable interactions with co‐workers.

Conclusions

Patients attribute daily and long‐term adverse work outcomes to asthma. Asthma severity and demographic and occupational characteristics were associated with adverse occurrences. Am. J. Ind. Med. 44:236–245, 2003. © 2003 Wiley‐Liss, Inc.
Participatory ergonomics as a return‐to‐work intervention: A future challenge?
Authors: Anema J.R. , Steenstra I.A. , Urlings I.J.M. , Bongers P.M. , de Vroome E.M.M. , van Mechelen W.
Published: August 2003

Background

Participatory ergonomics (PE) are often applied for prevention of low back pain (LBP). In this pilot‐study, a PE‐program is applied to the disability management of workers sick listed due to LBP.

Methods

The process, implementation, satisfaction, and barriers for implementation concerning the PE‐program were analyzed quantitatively and qualitatively for 35 workers sick listed 2–6 weeks due to LBP and their ergonomists.

Results

Two‐hundred‐and‐seventy ergonomic solutions were proposed to the employer. They were targeted more at work design and organization of work (58.9%) than at workplace and equipment design (38.9%). They were planned mostly on a short‐term basis (74.8%). Almost half (48.9%) of the solutions for work adjustment were completely or partially implemented within 3 months after the first day of absenteeism. Most workers were satisfied about the PE‐program (median score 7.8 on a 10‐point scale) and reported a stimulating effect on return‐to‐work (66.7%). Main obstacles to implementation were technical or organizational difficulties (50.0%) and physical disabilities of the worker (44.8%).

Conclusions

This study suggests that compliance, acceptance, and satisfaction related to the PE‐program were good for all participants. Almost half of the proposed solutions were implemented. Am. J. Ind. Med. 44:273–281, 2003. © 2003 Wiley‐Liss, Inc.
Previously undetected silicosis in New Jersey decedents
Authors: Goodwin Susan S. , Stanbury Martha , Wang Mei‐Lin , Silbergeld Ellen , Parker John E.
Published: August 2003

Background

Despite a reported decline in mortality and hospitalizations associated with silicosis [U.S. Department of Health and Human Services, 1999], this decline may be artifactual, stemming in part from underdiagnosis by physicians.

Methods

This study estimates, through radiological confirmation, the prevalence of unrecognized silicosis in a group of silica‐exposed New Jersey decedents whose cause of death was chronic obstructive pulmonary disease (COPD), tuberculosis, or cor pulmonale. Two expert readers re‐evaluated the chest X‐rays of this group to determine the presence or absence of silicosis. The study population was considered to be presumptively exposed to silica dust by virtue of their usual industry of employment as listed on the death certificate.

Results

Radiographic evidence of silicosis was found in 8.5% of this population, and evidence of asbestosis was found in another 10.7%, for a total of 19.2%.

Conclusions

The existence of previously unrecognized silicosis and asbestosis in 19.2% of this study group suggests that occupational lung disease is under‐recognized and, hence, undercounted. Am. J. Ind. Med. 44:304–311, 2003. © 2003 Wiley‐Liss, Inc.
The concordance of pollution prevention and occupational health and safety: A perspective on U.S. policy
Authors: Enander Richard T. , Gute David M. , Cohen Howard J.
Published: August 2003

Background

Occupational health and pollution prevention, although conceptually linked by the common goals of preventing exposure to toxic materials and lowering risk functions, have been largely confined to separate patterns of practice and professional development. Some analysts see this as a missed opportunity for synergy and raising the level of protection afforded to both the worker and the ambient environment. By using current specific examples we show how strategies that integrate pollution prevention and occupational health practices can be effective at reducing chemical exposures and environmental releases beyond the levels normally achieved using traditional methods alone.

Methods

Similarities in approaches to addressing chemical hazards at the source, are analyzed in the context of U.S. policy and recent state and federal initiatives. Results obtained from the analysis of multi‐pathway risks found within the automotive refinishing sector serve as examples of how best to select engineering and control strategies.

Results

Industry survey, metal speciation, and methylene chloride usage data from studies conducted in Rhode Island, coupled with case reports from other settings, demonstrate that opportunities exist to concurrently mitigate multiple environmental and occupational health hazards.

Conclusions

The collaborative initiatives undertaken in the automotive refinishing industry sector demonstrate that an integrated environmental and occupational health approach can more effectively address multiple chemical releases and workplace exposures. Such synergy should be advanced in the future by similar integrative and collaborative strategies. Am. J. Ind. Med. 44:312–320, 2003. © 2003 Wiley‐Liss, Inc.
Occupational asthma (OA) with sensitization to diphenylmethane diisocyanate (MDI) presenting at the onset like a reactive airways dysfunction syndrome (RADS)
Authors: Perfetti Luca , Bramé Barbara , Ferrari Massimo , Moscato Gianna
Published: August 2003

Background

Two types of OA are distinguished: immunological (OA with sensitization) and non‐immunological, i.e., irritant induced asthma or reactive airways dysfunction syndrome (RADS).

Methods

We describe the case of a worker who developed respiratory symptoms after a spill of diphenylmethane diisocyanate (MDI) at the workplace. RADS was initially diagnosed and the worker resumed working. The progressive worsening of symptoms and the appearance of symptoms–work relationship one year later, when concentrations of isocyanates were no longer “irritant,” suggested immunological OA.

Results

The diagnosis was confirmed by specific inhalation challenge test, followed by removal from exposure and complete recovery.

Conclusions

In the case of RADS due to an agent with both irritant and sensitizing properties, history should be repeatedly assessed for a possible symptom–work relationship. If this is found, further investigations should be carried out, including specific inhalation challenges, to confirm the possibility of immunological OA. Am. J. Ind. Med. 44:325–328, 2003. © 2003 Wiley‐Liss, Inc.
Asbestos fiber length as related to potential pathogenicity: A critical review
Authors: Dodson Ronald F. , Atkinson Mark A.L. , Levin Jeffrey L.
Published: August 2003

Background

Asbestos inhalation is recognized as an exposure that increases the risk for the development of lung disease. It is unique among dusts in that it is both a carcinogen and capable of inducing extrapulmonary responses such as pleural thickening and fibrosis as well as malignancy. One feature of asbestos suggested as crucial in its pathological activity is its fibrous morphology. Long fibers that have been inhaled are cleared less readily and are thus more persistent in the body. Furthermore certain experimental models link fiber length to levels of risks for development of certain diseases. The present review will survey the data on this subject.

Methods

The review considers experimental models that have been used to assess the response to various lengths of fibers in animal models in addition to data obtained from studies of human materials. The review also emphasizes the importance in defining the method by which a sample is categorized.

Results

Data are offered which support the potential for longer fibers as well as shorter fibers to contribute to pathological responses.

Conclusions

The data presented argue that asbestos fibers of all lengths induce pathological responses and that caution should be exerted when attempting to exclude any population of inhaled fibers, based on their length, from being contributors to the potential for development of asbestos‐related diseases. Am. J. Ind. Med. 44:291–297, 2003. © 2003 Wiley‐Liss, Inc.
Reliability of data from next‐of‐kin: Results from a case‐control study of occupational and lifestyle risk factors for cancer
Authors: Kaerlev Linda , Lynge Elsebeth , Sabroe Svend , Olsen Jorn
Published: August 2003

Background

Use of surrogate responders often needs to be considered in case‐control studies with a high case fatality.

Methods

Agreement between 98 colon cancer patients and their closest relative was expressed as a percentage of the exact agreement and by Kappa coefficients and intra‐class correlation coefficients.

Results

The percentage of “don't know” answers was higher for surrogates than for index cases and the highest percentage was seen for questions on early events like childhood diseases. Agreement was best for responses to dichotomous questions on smoking and for prevalent or chronic diseases like diabetes or psoriasis, and lower (54–64%) when a quantitative response of, e.g., smoking was requested. The next‐of‐kin reported fewer job periods than the study person, 4.5 and 2.8, respectively, and there was a higher agreement for the latest job held than for the longest held job. We found an overall agreement between 91% and 100% for responses to ever having worked in a specific type of industry or occupation.

Conclusions

Use of next‐of‐kin data will often be a better alternative than excluding severely ill or deceased cases, if the exposure under study correlates with disease progression. Am. J. Ind. Med. 44:298–303, 2003. © 2003 Wiley‐Liss, Inc.