bluuebunny/crossref_metadata_2025 huggingface dataset:
Low Back Pain in Professional Golfers
Authors: Vad Vijay B. , Bhat Atul L. , Basrai Dilshaad , Gebeh Ansu , Aspergren Donald D. , Andrews James R.
Published: February 2004

Background

Low back pain is fairly prevalent among golfers; however, its precise biomechanical mechanism is often debated.

Hypothesis

There is a positive correlation between decreased lead hip rotation and lumbar range of motion with a prior history of low back pain in professional golfers.

Study Design

A cross-sectional study.

Methods

Forty-two consecutive professional male golfers were categorized as group 1 (history of low back pain greater than 2 weeks affecting quality of play within past 1 year) and group 2 (no previous such history). All underwent measurements of hip and lumbar range of motion, FABERE's distance, and finger-to-floor distance. Differences in measurements were analyzed using the Wilcoxon signed rank test.

Results

33% of golfers had previously experienced low back pain. A statistically significant correlation (P < .05) was observed between a history of low back pain with decreased lead hip internal rotation, FABERE's distance, and lumbar extension. No statistically significant difference was noted in nonlead hip range of motion or finger-to-floor distance with history of low back pain.

Conclusions

Range-of-motion deficits in the lead hip rotation and lumbar spine extension correlated with a history of low back pain in golfers.
Near Infrared Spectroscopy in the Diagnosis of Chronic Exertional Compartment Syndrome
Authors: van den Brand Johan G. H. , Verleisdonk Egbert J. M. M. , van der Werken Christian
Published: February 2004

Background

Patients with chronic exertional compartment syndrome (CECS) experience pain during exercise. An abnormal increase in intracompartmental pressure (ICP) leads to impaired local tissue perfusion resulting in ischemia and pain. At cessation of exercise, pain subsides. Diagnosis is confirmed through postexercise ICP. Near infrared spectroscopy (NIRS) can measure tissue oxygen saturation (StO2)noninvasively.

Hypothesis

NIRS can diagnose CECS by showing tissue deoxygenation.

Study Design

Prospective, nonrandomized clinical trial.

Method

Volunteers completed a standardized exercise protocol. Those suspected of CECS did so preoperatively and postoperatively. StO2 and ICP were monitored. Data were compared between volunteers and patients and prefasciotomy and postfasciotomy.

Results

Significant differences between the StO2 values of volunteers and patients with CECS were found. Average peak exercise StO2 value for those with CECS was lower than for the healthy (27 versus 56, P < .05). Patients showed more absolute and percentage change between baseline and peak exercise StO2 (absolute: 60 versus 35, P < .05; percentage: 67 versus 38, P < .05). StO2 values in legs with confirmed CECS returned to normal range postfasciotomy. All changes differed significantly with preoperative values.

Conclusion

StO2 can distinguish healthy from diseased legs. This study provides evidence supporting NIRS as a noninvasive, painless alternative to ICP in the diagnosis of CECS.
The Posteromedial Corner of the Knee
Authors: Sims William F. , Jacobson Kurt E.
Published: February 2004

Background

Medial-sided knee injury patterns have been poorly defined in the available literature. The lack of definition can be attributed to the differing anatomic perspectives of physician authors and the functional significance they assigned to the posteromedial structures of the knee.

Hypothesis

Many so-called medial collateral ligament injuries can involve significant damage to the posteromedial corner structures that may not be appreciated.

Study Design

Retrospective cohort study.

Method

The authors reviewed the charts of 93 patients (93 knees) with operatively treated isolated and combined medial-sided knee injuries and described the associated medial injury patterns.

Results

Ninety-nine percent of the knees were found to have an injury of the posterior oblique ligament. In the series, 70% of the knees also had an injury of the semimembranosus capsular attachment, and 30% were found to have complete peripheral detachment of the meniscus. Injury to the posterior oblique ligament was the common injury, but other sites of disruption capable of disabling this dynamic meniscocapsular complex were present.

Conclusions

Before assigning function to the various posteromedial structures of the knee, we must better define medial-sided injury patterns, the purpose of the current work. From this review of medial-sided injuries in this series of patients, the authors have come to realize that a subgroup of these knee injuries involves injuries to the posteromedial structures that are underappreciated.
Abdominal aortic aneurysm in association with a congenital pelvic horseshoe kidney: sentinel report and technical consideration
Authors: Renzulli Joseph F , Borromeo Jose Roberto , Barkhordarian Siamak , Sumpio Bauer E
Published: February 2004

A case of an abdominal aortic aneurysm in the presence of a congenital pelvic horseshoe kidney is described and the technical approach discussed. Renal function was preserved by ‘double clamping’ during the proximal anastomosis and infusing cold crystalloid into cannulated renal arteries originating from the aneurysm sac.
Design of the START-trial: STimulation of ARTeriogenesis using subcutaneous application of GM-CSF as a new treatment for peripheral vascular disease. A randomized, double-blind, placebo-controlled trial
Authors: van Royen Niels , Piek Jan J , Legemate Dink A , Schaper Wolfgang , Oskam Jacques , Atasever Bektas , Voskuil Michiel , Ubbink Dirk , Schirmer Stephan H , Buschmann Ivo , Bode Christoph , Buschmann Eva E
Published: February 2004

Peripheral arterial disease (PAD) affects a large percentage of the elderly population. Standard invasive treatment, apart from risk factor modulation, consists of bypass surgery or percutaneous transluminal angioplasty. However, symptomatic recurrence rates are high for both procedures and a substantial part of the patient population with PAD is not a candidate for invasive revascularization due to complexity of the lesion and/or co-morbidity. Therapeutic arteriogenesis has been proposed as an alternative treatment option. The present paper describes the design of the START-trial. This trial aims to determine the potential of the proarteriogenic substance granulocyte/macrophage colony stimulating factor (GM-CSF) to increase maximal walking distance in patients with intermittent claudication. A double-blinded, randomized, placebo-controlled study will be performed in 40 patients with peripheral obstructive arterial disease Rutherford grade I, category 2 or 3, that are candidates for bypass surgery or percutaneous transluminal angioplasty. Based on pharmacokinetic and toxicologic studies, a dose of 10 mg/kg will be used. Patients will be treated for a period of 14 days on each consecutive day, with the last injection applied on day 12. The primary endpoint will be the change in walking distance from day 0 to day 14 as assessed by an exercise treadmill test. Secondary endpoints will be the ankle-brachial index at rest and after exercise, the pain-free walking distance and cutaneous microcirculatory alterations as assessed by laser Doppler fluxmetry. Iliac flow reserve and conductance will be measured by magnetic resonance imaging.
Rapid manufacturing techniques in the development of an axial blood pump impeller
Authors: Chan W K , Wong Y W , Chua C K , Lee C W , Feng C
Published: February 2004

This paper presents a comparison of manufacturing techniques used in the development of an axial blood pump impeller. In this development process the impeller was designed and its performance was evaluated with the aid of computational fluid dynamics (CFD). Prototypes of those designs where the CFD results show promise were needed in sufficient quantities at a low cost for experimental validation of the CFD results. As the impeller is less than 16 mm in diameter with a maximum blade thickness of about 1.5 mm, innovative manufacturing techniques are explored in this paper to determine the best process for quick fabrication of prototypes that are dimensionally accurate, structurally robust and low in cost. Four rapid prototyping techniques were explored. The completed parts were compared on the basis of manufacturing time, quality and strength of parts obtained, manufacturing cost and also in vitro performances. Based on these studies, it was concluded that selective laser sintering (SLS) is the most appropriate method for the quick production of prototype parts for evaluation of pump performance.
Ophthalmological Preparations
Authors: Dolak Terence M. , Lever O. William , Marsh David , Moran Irene , Sutton Scott
Published: February 2004

The article contains sections titled:

1.Introduction2.Anesthetics2.1.Topical Anesthetics2.2.Regional Anesthetics3.Antimicrobial Agents3.1.Antibacterial Agents3.1.1.Sulfonamides3.1.2.β‐Lactam Antibiotics3.1.2.1.Penicillins3.1.2.2.Cephalosporins3.1.3.Tetracycline Antibiotics3.1.4.Aminoglycoside Antibiotics3.1.5.Polypeptide Antibiotics3.1.6.Miscellaneous Antimicrobial Agents3.2.Antifungal Agents3.3.Antiprotozoal Agents3.4.Antiviral Agents4.Anti‐inflammatory Agents4.1.Corticosteroids4.2.Miscellaneous Anti‐inflammatory Agents5.Antiglaucomatous Agents5.1.Sympathomimetic Drugs5.2.β‐Adrenergic Blocking Agents5.3.Carbonic Anhydrase Inhibitors5.4.Hyperosmotic Agents5.5.Miotics (Parasympathomimetic Agents)5.5.1.Cholinergic Agonists5.5.2.Anticholinesterases6.Mydriatics and Cycloplegics6.1.Sympathomimetics6.2.Parasympatholytics7.Vasoactive (Adrenergic) Agents8.Diagnostic Agents9.Dry Eye Medications10.Miscellaneous Ophthalmic and Contact Lens Preparations10.1.Disinfectants and Preservatives10.1.1.Biguanides10.1.2.Mercurial Preservatives10.1.3.Quaternary Ammonium Compounds10.1.4.Miscellaneous Disinfectants and Preservatives10.2.Contact Lens Cleaners and Rewetting Agents10.2.1.Surfactant Cleaners10.2.2.Enzymatic Cleaners
Multi‐Principal‐Element Alloys with Improved Oxidation and Wear Resistance for Thermal Spray Coating
Authors: Huang P.‐K. , Yeh J.‐W. , Shun T.‐T. , Chen S.‐K.
Published: February 2004

Multi‐principal‐element alloy coatings of Al‐Si alloys were prepared by a plasma spray method. They not only exhibited a good oxidation resistance up to 1000 °C, but also possessed an excellent abrasive wear resistance approximately two times higher than those of SUJ2 and SKD61. Moreover, they displayed a high temperature precipitation hardening phenomenon up to 1100 °C which is novel and seldom found in conventional alloys.
Iso‐work Increment Assumption for Heterogeneous Material Behaviour Modelling
Authors: Bouaziz O. , Buessler P.
Published: February 2004

Assuming an equi‐incremental mechanical work in each constituent in stress‐strain mixture law, this article focuses on the interest of this approach through comparison with miscellaneous experimental results and with other modelling methods as Taylor, Sachs, self‐consistent or 3D finite element modelling.
The Enhancement of Metal‐to‐Ceramics Adhesion Bond Under Sintering in Microwave Fields
Authors: Pan E.G. , Ravaev A.A.
Published: February 2004

The article summarizes some of the most interesting results of experimental investigations searching for new ways of improving the adherence of oxide ceramics to alloys in metal‐ceramic structures. The method described in the article and tested with dental porcelain and Ni‐Cr alloy allows to increase the adherence of such structures by several times. The physical phenomena identified in the experiments are of fundamental nature, particularly, the abnormally high metal diffusion into ceramics and unusual behaviour of materials under the effect of electromagnetic field.
Hydrogen in Nano‐sized Metals
Authors: Pundt A.
Published: February 2004

Systems with small sizes show significant changes compared to the bulk system. These changes are of major interest regarding the size reduction of technological applications. The hydrogen‐metal system can be used as a model alloy to study small size features: shifted phase boundaries and sloped isotherms are found and, also, new materials structures. Most features can be attributed to surface‐ and interface contributions as well as to mechanical stress.
Mask‐free Localized Grafting of Organic Polymers at the Micrometer or Submicrometer Scale on Composite Conductors or Semiconductor Substrates
Authors: Charlier J. , Ameur S. , Bourgoin J. P. , Bureau C. , Palacin S.
Published: February 2004

This work presents a new one‐step process enabling the mask‐free localized functionalization by organic polymers of the conducting or semiconducting parts of composite surfaces at the micrometer and submicrometer scale. The functionalization is carried out via cathodic electrografting of suitable precursors of composite cathodes, which gives an insulating polymer film strongly grafted to selected parts of the composite electrodes and guarantees that the resolution is that of the pre‐existing pattern, even when the whole surface is dipped into the reaction medium. The presumed mechanism is based on a regioselective extraction of electrons from the composite surface according to its apparent local work function in solution.
Spatially Selective Nucleation of Metal Clusters on the Tobacco Mosaic Virus
Authors: Knez M. , Sumser M. , Bittner A. M. , Wege C. , Jeske H. , Martin T. P. , Kern K.
Published: February 2004

Tobacco mosaic virus (TMV) is a very stable nanotube complex of a helical RNA and 2130 coat proteins. The special shape makes it an interesting nano‐object, especially as a template for chemical reactions. Here we use TMV as a chemically functionalized template for binding metal ions. Different chemical groups of the coat protein can be used as ligands or to electrostatically bind metal ions. Following this activation step, chemical reduction and electroless plating produces metal clusters of several nanometers in diameter. The clusters are attached to the virion without destroying its structure. Gold clusters generated from an ascorbic acid bath bind to the exterior surface as well as to the central channel of the hollow tube. Very high selectivity is reached by tuning PdII and PtII activations with phosphate: When TMV is first activated with PdII, and thereafter metallized with a nickel–phosphinate bath, 3 nm nickel clusters grow in the central channel; when TMV from phosphate‐buffered suspensions is employed, larger nickel clusters grow on the exterior surface. Phosphate buffers have to be avoided when 3 nm nickel and cobalt wires of several 100 nm in length are synthesized from borane‐based baths inside the TMV channel. The results are discussed with respect to the inorganic complex chemistry of precursor molecules and the distribution of binding sites in TMV.
Build‐up of Polypeptide Multilayer Coatings with Anti‐Inflammatory Properties Based on the Embedding of Piroxicam–Cyclodextrin Complexes
Authors: Benkirane‐Jessel N. , Schwinté P. , Falvey P. , Darcy R. , Haïkel Y. , Schaaf P. , Voegel J.‐C. , Ogier J.
Published: February 2004

We describe the build‐up of biomaterial coatings based on polypeptide multilayers possessing anti‐inflammatory properties. Poly(L‐lysine) (PLL) and poly(L‐glutamic acid) (PGA) are used as polypeptides, and piroxicam (Px) is used as the anti‐inflammatory agent. In order to embed high enough amounts of Px, the drug is incorporated in the films in the form of complexes with a charged 6A‐carboxymethylthio‐β‐cyclodextrin (cCD). It is shown that this cyclodextrin can solubilize higher amounts of Px than the cyclodextrins used commercially. The anti‐inflammatory properties are evaluated by determining the inhibition of TNFα production by human monocytic THP‐1 cells stimulated with lipopolysaccharide (LPS) bacterial endotoxin. Using Fourier‐transform (FT) Raman spectroscopy, we show that Px is mainly in the neutral form in cCD–Px complexes in solution, and that it remains biologically active under this form, whereas up to now only the zwitterionic form was reported to possess anti‐inflammatory properties. When incorporated in PLL/PGA multilayers, Px in the cCD–Px complexes changes from the neutral to the zwitterionic form. It is shown that these films present anti‐inflammatory properties, which can be delayed, and whose duration can be tuned by changing the film architecture.
A Simple and Effective Route for the Synthesis of Crystalline Silver Nanorods and Nanowires
Authors: Hu J.‐Q. , Chen Q. , Xie Z.‐X. , Han G.‐B. , Wang R.‐H. , Ren B. , Zhang Y. , Yang Z.‐L. , Tian Z.‐Q.
Published: February 2004

A simple and effective approach to the aqueous‐phase synthesis of crystalline silver nanorods and nanowires is demonstrated, using which their diameters and aspect ratios can be effectively controlled. The synthesis involves a template‐less and non‐seed process to high‐quality nanoparticles, which is low‐cost and proceeds at moderate temperatures. The nanorods and nanowires were synthesized by the reduction of silver nitrate with tri‐sodium citrate in the presence of sodium dodecylsulfonate. The concentration of tri‐sodium citrate plays a critical role while sodium dodecylsulfonate, as a capping agent, only plays an assistant role in controlling the diameters and aspect ratios of the products. High‐resolution transmission electron microscopy (HRTEM) and selected‐area electron diffraction (SAED) investigations show that the silver nanocrystals are generated with a twinned crystalline structure. We also put forward a primary experimental model to shed light on their growth mechanisms.
Alizarin Complexone on Nanocrystalline TiO2: A Heterogeneous Approach to Anion Sensing
Authors: Palomares E. , Vilar R. , Green A. , Durrant J. R.
Published: February 2004

A novel, heterogeneous approach to “naked‐eye” colorimetric and spectrophotometric anion sensing is demonstrated, employing the molecular receptor alizarin complexone adsorbed onto a nanocrystalline, mesoporous TiO2 film. pH buffer action intrinsic to the TiO2 film allows dip sensing in aqueous solutions. This heterogeneous sensing system exhibits a high selectivity to F– and CN– anions, high sensitivity, a rapid response time, and excellent reusability.
Columnar Liquid Crystals with a Central Crown Ether Unit
Authors: Schultz A. , Laschat S. , Saipa A. , Gießelmann F. , Nimtz M. , Schulte J. L. , Baro A. , Miehlich B.
Published: February 2004

Novel columnar liquid crystals 5a–f bearing a dibenzo[18]crown[6] central unit have been prepared from bromodialkyloxybenzenes 1 and tetrabromodibenzo[18]crown[6] 2 via Suzuki coupling reactions. Differential scanning calorimetry (DSC) revealed that the length of the alkyl chains in the liquid‐crystalline compounds 5 influenced their mesomorphic properties. Whereas 5a–d gave fan‐shaped textures only upon rapid cooling, 5e and 5f with C9 and C10 side chains formed stable columnar textures upon slow cooling. A hexagonal columnar mesophase of 5a is apparent from X‐ray diffraction studies. Complexation of 5 with potassium significantly shifted the clearing points to higher temperatures and also increased the mesophase stability in the cooling cycle.
Conducting‐Polymer Microcontainers: Controlled Syntheses and Potential Applications
Authors: Bajpai V. , He P. , Dai L.
Published: February 2004

We have demonstrated the controlled synthesis of conducting‐polymer microcontainers through the electrochemical generation of surfactant (i.e., β‐naphthalenesulfonic acid, β‐NSA)‐stabilized H2 gas bubbles on the working electrode, followed by electrochemical polymerization of pyrrole around the wall of the “soap‐bubble” template. It was noticed that the density, shape, and wall thickness of the polypyrrole microcontainers thus prepared could be regulated by controlling the electrochemical potential applied for the generation of H2 gas and the experimental conditions (e.g., the surfactant concentration, number of the cyclic voltammetric scanning) for the electropolymerization of pyrrole. By pre‐patterning the working electrode surface with non‐conducting polymers using microcontact printing (μCP) or plasma patterning, we have also produced conducting‐polymer microcontainers in a patterned fashion. Furthermore, potential applications of the patterned and non‐patterned conducting‐polymer microcontainers have been demonstrated; for example, through the encapsulation of appropriate fluorescence‐labeled molecules (e.g., fluorescein cadaverin) into the conducting‐polymer microcontainers by sealing their opened mouths with sequential electropolymerization of pyrrole. The resulting closed microcontainers could then be used for controlled releases.
On the Feasibility of Growing Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 Single Crystals
Authors: Fang B.‐J. , Shan Y.‐J. , Xu H.‐Q. , Luo H.‐S. , Yin Z.‐W.
Published: February 2004

Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 (PZNT91/9) single crystals were grown by two methods: from solution using PbO as a self‐fluxing agent (SC method) and directly from the melt without fluxing (MC method). In both growth methods, an allomeric Pb[(Mg1/3‐Nb2/3)0.69Ti0.31]O3 (PMNT69/31) single crystal was used as a seed. X‐ray diffraction patterns of ground crystals showed that phase‐pure perovskite PZNT91/9 single crystals were successfully fabricated by the above two methods. The composition of the crystals obtained by both the SC and MC methods was analyzed using X‐ray fluorescence, which confirmed that the crystal composition is close to the nominal value, although volatilization of PbO and segregation during crystal growth are inevitable. The MC PZNT91/9 crystals exhibit excellent piezoelectric properties, with the piezoelectric constant, d33, in the range of 1800–2200 pC N–1. This value is comparable to that of the SC crystals. However, the MC crystals show an abnormal dielectric behavior. In contrast with the SC crystals, in the MC crystals a much broader dielectric peak appears in the dielectric response curves, accompanied by a much lower peak temperature of around 105 °C. Furthermore, frequency dispersion is apparent over a much wider temperature range (even more apparent than in pure relaxors), where a large, i.e., about 70 °C, full width at half maximum (FWHM) for the dielectric peaks is observed in the dielectric response. It is speculated that such an unusual phenomenon correlates with defects, microinhomogeneities, and polar regions in the as‐grown MC crystals. The origins of this abnormality have not been interpreted in detail until now. However, optical observation of the domain structure confirms that both the SC and MC crystals possess complex structural states.
Properties of Carbon Nanotube Fibers Spun from DNA‐Stabilized Dispersions
Authors: Barisci J. N. , Tahhan M. , Wallace G. G. , Badaire S. , Vaugien T. , Maugey M. , Poulin P.
Published: February 2004

The fabrication of single‐walled carbon nanotube (CNT) fibers containing (salmon) DNA has been demonstrated. The DNA material has been found to be adequate for dispersing relatively large concentrations (up to 1 % by weight) of carbon nanotubes. These dispersions are better suited for fiber spinning than previously studied dispersions based on conventional surfactants, such as sodium dodecyl sulfate (SDS). The DNA‐containing fibers were less conductive than the fibers based on SDS, but they were significantly stronger. Considerably increased conductivity was obtained by thermally annealing the CNT/DNA fibers, a process accompanied by a loss in mechanical strength. Smaller improvements in conductivity could be introduced by annealing the carbon nanotubes before fiber production, with no alteration of the fiber mechanical properties. Those CNT/DNA fibers that were mechanically strong and conductive also exhibited good electrochemical behavior and useful capacitance values (up to 7.2 F g–1).
Efficient and Photostable ZnS‐Passivated CdS:Mn Luminescent Nanocrystals
Authors: Yang H. , Holloway P. H.
Published: February 2004

Efficient and photostable ZnS‐passivated CdS:Mn (CdS:Mn/ZnS core/shell) nanocrystals were synthesized using reverse micelle chemistry. CdS:Mn/ZnS core/shell nanocrystals exhibited much improved luminescent properties (quantum yield and photostability) over organically (n‐dodecanethiol‐) capped CdS:Mn nanocrystals. This is the result of effective, robust passivation of CdS surface states by the ZnS shell and consequent suppression of non‐radiative recombination transitions. The dependence of photoluminescence (PL) intensity has been observed as a function of UV irradiation time for both organically and inorganically capped CdS:Mn nanocrystals. Whereas organically capped CdS:Mn nanocrystals exhibit a significant reduction of PL intensity, CdS:Mn/ZnS core/shell nanocrystals exhibit an increased PL intensity with UV irradiation. XPS (X‐ray photoelectron spectroscopy) studies reveal that UV irradiation of CdS:Mn/ZnS nanocrystals in air atmosphere induces the photo‐oxidation of the ZnS shell surface, leading to the formation of ZnSO4. This photo‐oxidation product is presumably responsible for the enhanced PL emission, serving as a passivating layer.
Selective Atmospheric Pressure Chemical Vapor Deposition Route to CdS Arrays, Nanowires, and Nanocombs
Authors: Ge J. P. , Li Y. D.
Published: February 2004

CdS arrays, nanowires, and nanocombs were selectively prepared through an atmospheric pressure chemical vapor deposition (APCVD) process with CdCl2 and S as sources. The morphologies could be controlled by adjusting the deposition position, the temperature, and the flux of the carrier gas. The phase structure, morphologies, and photoluminescence properties of the CdS products were investigated by X‐ray diffraction (XRD), scanning electron microscopy (SEM), high‐resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra. The formation mechanism of the nanowires is discussed on the basis of the experimental results. The adopted synthetic route is expected to be applied in the synthesis of other metal sulfide one‐dimensional (1D) nanostructures.
Loading Fullerene into a Conjugated Polymer Without Chemical Modification
Authors: Tada K. , Onoda M.
Published: February 2004

Conjugated polymers doped with fullerenes show excellent photoconversion efficiencies. However, due to the poor solubility of pure C60 in common organic solvents, it was thought that some chemical modifications to C60 were required in order to load conjugated polymers with comparable weights of fullerene. Here, we report a novel way to load large amounts of unmodified C60 fullerene into the conjugated polymer poly(2‐methoxy‐5‐(2′‐ethylhexoxy)‐1,4‐phenylenevinylene), MEH‐PPV. The principle of our approach is to separate the film‐deposition stage from the material‐solidification stage. That is, materials are quickly solidified from dilute solution into colloidal particles, which are large enough to be collected by electrophoretic deposition. Deposition from a mixture of separate suspensions of MEH‐PPV and C60 fullerene resulted in films consisting of isolated particles. In contrast, by using a suspension made of a dilute solution of MEH‐PPV and C60, which was so dilute that traditional techniques such as spin‐coating were not applicable, an MEH‐PPV film doped with 20 mol‐% C60, corresponding to an almost 1:1 ratio by weight of molecularly dispersed C60, was easily obtained. To the best of our knowledge, this is the first report on the successful loading of an equivalent weight ratio of unmodified C60 molecules into MEH‐PPV.
Inkjet Printing of Polymers: State of the Art and Future Developments
Authors: de Gans B.‐J. , Duineveld P. C. , Schubert U. S.
Published: February 2004

Inkjet printing is considered to be a key technology in the field of defined polymer deposition. This article provides an introduction to inkjet printing technology and a short overview of the available instrumentation. Examples of polymer inkjet printing are given, including the manufacturing of multicolor polymer light‐emitting diode displays, polymer electronics, three‐dimensional printing, and oral dosage forms for controlled drug release. Special emphasis is placed upon the utilized polymers and conditions, such as polymer structure, molar mass, solvents, and concentration. Studies on viscoelastic fluid jets and the formation of viscoelastic droplets under gravity indicate that strain hardening is the key parameter that determines the inkjet printability of polymer solutions.
Highly Oriented and Ordered Arrays from Block Copolymers via Solvent Evaporation
Authors: Kim S. H. , Misner M. J. , Xu T. , Kimura M. , Russell T. P.
Published: February 2004

A simple process of solvent evaporation is shown to produce highly ordered arrays of cylindrical microdomains in block copolymers with long‐range lateral order (see Figure). Solvent evaporation in thin films is unidirectional, producing a self‐assembly directed normal to the film surface, akin to a zone refinement. Further control over the size and separation distance of the domains can be achieved with cosolvents.
Phototactic Mass Transport in Polymer Films for Micropatterning and Alignment of Functional Materials
Authors: Ubukata T. , Hara M. , Ichimura K. , Seki T.
Published: February 2004

A new micropatterning technique based on photoinduced mass transport in a polymer film is presented. The Figure shows a rod‐like dye crystallized aligned along a surface relief grating (SRG) on an azobenzene polymer film produced by photoirradiation through a photomask. The uniaxial alignment is achieved by one‐dimensional diffusion—restricted by the grating geometry—of the dye molecule.
Rapid Fabrication of Binary Colloidal Crystals by Stepwise Spin‐Coating
Authors: Wang D. , Möhwald H.
Published: February 2004

Binary colloidal crystals (see Figure) of large (L) and small (S) silica colloidal spheres with large diameter ratios have been rapidly constructed by stepwise spin‐coating. The dominant structure of the resultant crystals is LS2, with which the LS3 structure usually coexists. The diameter ratio and the speed of spin‐coating are used to control the structures, with higher spin speeds favoring the formation of LS3 structures.
A Snowman‐like Array of Colloidal Dimers for Antireflecting Surfaces
Authors: Koo H. Y. , Yi D. K. , Yoo S. J. , Kim D.‐Y.
Published: February 2004

Fabrication of motheye‐like colloidal surface patterns as an antireflection coating is presented. Using layer‐by‐layer assembly and a novel colloid‐on‐colloid stamping strategy, snowman‐like patterns consisting of different‐sized colloids were fabricated (see Figure). The pattern spacing and height can be easily tailored by varying the salt concentration and the number of colloidal layers attached, respectively.
Crystalline Colloidal Arrays Composed of Poly(3,4‐ethylenedioxythiophene)‐Coated Polystyrene Particles with a Stop Band in the Visible Regime
Authors: Han M. G. , Foulger S. H.
Published: February 2004

Monodisperse polystyrene particles with a diameter of ca. 100 nm have been coated with 8 nm shells of poly(3,4‐ethylenedioxythiophene) (PEDOT) and self‐assembled into crystalline colloidal arrays (see Figure) with an observed stop band in the visible regime. These materials could be used in developing photonic crystals with frequency‐ and dopant‐dependent optical properties .
Porous Tin Oxides Prepared Using an Anodic Oxidation Process
Authors: Shin H.‐C. , Dong J. , Liu M.
Published: February 2004

Open, porous structures of tin oxides, fabricated by an anodic oxidation process, are characterized by irregular channels with diameters of several tens of nanometers, as shown in the Figure. The as‐prepared amorphous tin oxides can be transformed by annealing to a crystalline stannic structure with very few micro‐structural changes. The materials may find applications in batteries and chemical sensors.
Receptor‐Mediated Self‐Assembly of Multi‐Component Magnetic Nanowires
Authors: Salem A. K. , Chao J. , Leong K. W. , Searson P. C.
Published: February 2004

The directed orientation of ferromagnetic nanowires tethered to spatially controlled regions of a surface is reported. The Figure is a light microscope image of 9 μm‐long, two‐segment Au/Ni nanowires with a biotinylated Au segment tethered to patterned avidin tracks. The aspect ratio of the nickel segments is ∼ 50, so the magnetic easy axis is parallel to the wire axis. The nanowires have rotated to be parallel to an applied magnetic field.
Preparation of Conductive Nanotube–Polymer Composites Using Latex Technology
Authors: Regev O. , ElKati P. N. B. , Loos J. , Koning C. E.
Published: February 2004

Composites consisting of individual, or bundles of single‐walled, exfoliated nanotubes in a highly viscous polymer matrix (see Figure) are described. The nanotubes and polymer are made compatible using surfactant molecules, hence avoiding the need for direct attraction between the nanotubes and the matrix. The resulting nanotube–polymer composites have a conductivity percolation threshold of 0.28 wt.‐% nanotubes.
Direct Writing of Patterned Ceramics Using Electron‐Beam Lithography and Metallopolymer Resists
Authors: Clendenning S. B. , Aouba S. , Rayat M. S. , Grozea D. , Sorge J. B. , Brodersen P. M. , Sodhi R. N. S. , Lu Z.‐H. , Yip C. M. , Freeman M. R. , Ruda H. E. , Manners I.
Published: February 2004

Patterned arrays of ceramics have been fabricated using electron‐beam lithography (EBL) and a metallopolymer resist. Highly ordered arrays of dots, bars (see scanning electron microscopy and time‐of‐flight secondary ion mass spectrometry images in the Figure), and curved lines rich in Fe and Co are direct‐written on films of a highly metallized cobalt‐clusterized polyferrocenylsilane. Subsequent pyrolysis leads to ferromagnetic ceramics.
Aligned Gold Nanorods in Silica Made by Ion Irradiation of Core–Shell Colloidal Particles
Authors: Roorda S. , van Dillen T. , Polman A. , Graf C. , van Blaaderen A. , Kooi B. J.
Published: February 2004

Colloidal particles with a 14 nm diameter Au core surrounded by a 72 nm thick silica shell have been irradiated with 30 MeV heavy ions. The shell deforms into an oblate ellipsoid, while the core becomes rod‐shaped (aspect ratio up to 9) with the major axis along the beam. Optical extinction measurements show evidence for split plasmon bands, characteristic for anisotropic metal nanoparticles.
Immobilization of Protein Molecules by Size‐Selected Metal Clusters on Surfaces
Authors: Leung C. , Xirouchaki C. , Berovic N. , Palmer R. E.
Published: February 2004

Protein immobilization by nanocluster films is a new route to stabilize individual protein molecules and complexes for single‐molecule measurements such as liquid‐phase atomic force microscopy (AFM) imaging (see Figure). The sub‐monolayer films of size‐selected Au clusters present protein binding sites of arbitrary density.
Novel Nanostructured Electrodes for Solid Oxide Fuel Cells Fabricated by Combustion Chemical Vapor Deposition (CVD)
Authors: Liu Y. , Zha S. , Liu M.
Published: February 2004

Highly porous and nano‐structured electrodes for low‐temperature solid oxide fuel cells have been fabricated using a combustion chemical vapor deposition process. The composite electrodes consist of small grains, about 50 nm as shown in the Figure, have extremely high surface area, low interfacial polarization resistances, and high performance at low operating temperatures.
Multiple‐Walled Nanotubes Made of Metals
Authors: Sun Y. , Xia Y.
Published: February 2004

Metal nanotubes with multiple walls (see Figure) have been synthesized in bulk quantities using a combination of galvanic replacement reaction (between Ag nanowires and salt precursors) and an electroless plating process of silver. These nanotubes with controllable structure, composition, and morphology are expected to find uses ranging from catalysis to gas storage, optoelectronics, electronics, and optical sensing.
Nanocarving of Bulk Titania Crystals into Oriented Arrays of Single‐Crystal Nanofibers via Reaction with Hydrogen‐Bearing Gas
Authors: Yoo S. , Akbar S. A. , Sandhage K. H.
Published: February 2004

Oriented arrays of titania nanofibers have been fabricated by a simple and easily scalable method. Exposure to a 5 % H2/95 % N2 gas mixture at 700 °C transforms dense, polycrystalline rutile (TiO2) into arrays of single‐crystal nanofibers (15–50 nm diameter; see Figure, scale bar: 1 μm). The arrays could be used in of environmental, biomedical, transportation, chemical processing, and sensing applications.
Highly Efficient Biocatalysts via Covalent Immobilization of Candida rugosa Lipase on Ethylene Glycol‐Modified Gold–Silica Nanocomposites
Authors: Drechsler U. , Fischer N. O. , Frankamp B. L. , Rotello V. M.
Published: February 2004

The polymer‐mediated self‐assembly of silica and gold nanoparticles (see inset in Figure and cover) leads to extended aggregates. After calcination and subsequent surface modification, these aggregates serve as supports for the covalent immobilization of lipase (see Scheme). The obtained biocatalysts exhibit high efficiencies and long‐term stability.
Thermally Assisted Sub‐10 fs Electron Transfer in Dye‐Sensitized Nanocrystalline TiO2 Solar Cells
Authors: Stier W. , Duncan W. R. , Prezhdo O. V.
Published: February 2004

The sub‐10 fs photoinduced electron transfer from alizarin molecules to titania nanoparticles is simulated (see Figure; white: H; black: C; red: O; gray: Ti). The system provides a paradigm of the nanoscale coupling of organic and inorganic species. Remarkably, conduction is possible with photoexcitation below the conduction band and occurs by thermal activation.
Characterizing Joule Heating in Polymer Light‐Emitting Diodes Using a Scanning Thermal Microscope
Authors: Boroumand F. A. , Hammiche A. , Hill G. , Lidzey D. G.
Published: February 2004

Scanning thermal microscopy (SThM) has been used to study Joule heating in conjugated polymer light‐emitting diodes (LEDs; see Figure). The operational temperature of the LED is found to be a strong function of device area: smaller LEDs exchange heat more efficiently with their surrounding environment. The results suggest that at high current density, Joule heating may be linked to device failure.
Free Radical‐Mediated Acylation and Carboxylation Reactions
Authors: Kim Sunggak
Published: February 2004

Radical acylations to prepare carbonyl compounds are described and focus on indirect acylation approaches using sulfonyl oxime ethers under tin‐mediated and tin‐free conditions. The efficiency of carboxylic acid derivatives as carbonyl group radical acceptors in radical acylation and carboxylation reactions is discussed.
Achiral Dihydroxylation of Olefins by Osmate (OsO42−) Stabilised on Nanocrystalline Magnesium Oxide
Authors: Choudary Boyapati M. , Jyothi Karangula , Kantam Mannepalli L. , Sreedhar B.
Published: February 2004

A recoverable and reusable new heterogeneous AP‐Mg‐OsO4 catalyst was designed and developed for the first time via a counterionic stabilisation of OsO42− with Mg2+ present on the corner or edge of nanocrystalline MgO. AP‐Mg‐OsO4 catalysed the dihydroxylation of olefins to afford diols with excellent yields in the presence of N‐methylmorpholine N‐oxide for the first time. The absence of osmium and no progress of the dihydroxylation reaction with the filtrate samples withdrawn periodically during the reaction rule out the leaching of osmium unambiguously and provide evidence for the heterogeneity of the reaction. Identification of surface intermediate species by XPS and TGA‐DTA‐mass thermography gives an insight into the mechanism of the dihydroxylation reaction.
Rhodium Acetate Dimer Immobilized in 1‐Butyl‐3‐methylimidazolium Hexafluorophosphate Ionic Liquid: a Novel and Recyclable Catalytic System for the Cyclopropanation of Alkenes
Authors: Yadav J. S. , Reddy B. V. S. , Reddy P. Narayana
Published: February 2004

Alkenes undergo smooth cyclopropanation with ethyl diazoacetate using a catalytic amount of rhodium acetate dimer, Rh2(OAc)4, immobilized in the air‐ and moisture‐stable 1‐butyl‐3‐methylimidazolium hexafluorophosphate ionic liquid, [bmim]PF6, to afford cyclopropanecarboxylates in excellent yields with high trans‐selectivity. The recovery of the catalyst is facilitated by the hydrophobic nature of [bmim]PF6. The recovered ionic liquid containing Rh2(OAc)4 can be reused for three to five subsequent runs with only a gradual decrease in activity.
Phosphorus Acids as Highly Efficient Promoters for the Palladium‐Phenanthroline Catalyzed Carbonylation of Nitrobenzene to Methyl Phenylcarbamate†
Authors: Ragaini Fabio , Gasperini Michela , Cenini Sergio
Published: February 2004

A new family of promoters, based on phosphorus acids, is reported for the catalytic carbonylation of nitrobenzene to methyl phenylcarbamate by palladium‐phenanthroline complexes. With the new promoters, unprecedented reaction rates (TOF up to 6000/h) and catalyst stability (TON up to 105) could be reached. The best promoter is phosphoric acid, which is also very cheap, nontoxic and easily separable from the reaction products.
Enantioselective Hydrogenation of β‐Acylamino Acrylates Catalyzed by Rhodium(I)‐Monophosphite Complexes
Authors: Jerphagnon Thomas , Renaud Jean‐Luc , Demonchaux Patrice , Ferreira Amadéo , Bruneau Christian
Published: February 2004

Chiral rhodium(I) complexes bearing monophosphite ligands, prepared from chiral Binol and (L)‐menthol, were found to be efficient catalysts for the asymmetric hydrogenation of β‐acylamino acrylates with ee values up to 94%.
Efficient Synthesis of β,γ‐Alkynyl α‐Amino Acid Derivatives by Ag(I)‐Catalyzed Alkynylation of α‐Imino Esters
Authors: Ji Jian‐Xin , Au‐Yeung Terry T.‐L. , Wu Jing , Yip Chiu Wing , Chan Albert S. C.
Published: February 2004

The first catalytic synthesis of β,γ‐alkynyl α‐amino acid derivatives was achieved by direct addition of terminal alkynes to α‐imino esters in the presence of an Ag(I) salt under mild reaction conditions.
Cyclodextrins or Calixarenes: What is the Best Mass Transfer Promoter for Suzuki Cross‐Coupling Reactions in Water?
Authors: Hapiot F. , Lyskawa J. , Bricout H. , Tilloy S. , Monflier E.
Published: February 2004

Cyclodextrins or calixarenes possessing extended hydrophobic host cavities and surface‐active properties were found to be very efficient as mass transfer promoters for the palladium‐mediated Suzuki cross‐coupling reaction of 1‐iodo‐4‐phenylbenzene and phenylboronic acid in aqueous medium. The cross‐coupling rates were up to 92 times higher than those obtained without addition of any compound.
Mechanistic Aspects of Formation of Chiral Ruthenium Hydride Complexes from 16‐Electron Ruthenium Amide Complexes and Formic Acid: Facile Reversible Decarboxylation and Carboxylation
Authors: Koike Takashi , Ikariya Takao
Published: February 2004

The 16‐electron amide complex, Ru[(R,R)‐TsNCHPhCHPhNH](η6‐p‐cymene) (Ts=p‐toluenesulfonyl, Ph=C6H5) readily reacts with formic acid to give the corresponding formate complex, which subsequently undergoes decarboxylation leading to the hydride complex with release of CO2. The reaction of this hydride complex with CO2 under mild reaction conditions, a pressure of 10 atm and even at −78 °C, proceeds rapidly to give the corresponding formate complex almost quantitatively. Thus, the reversible decarboxylation and carboxylation takes place with or without the aid of a metal‐NH bifunctional effect of the Ru complexes.
Surfactant‐Stabilized Aqueous Iridium(0) Colloidal Suspension: An Efficient Reusable Catalyst for Hydrogenation of Arenes in Biphasic Media
Authors: Mévellec Vincent , Roucoux Alain , Ramirez Esther , Philippot Karine , Chaudret Bruno
Published: February 2004

Aqueous suspensions of iridium nanoparticles produced by the chemical reduction of IrCl3 assisted by sonication, in the presence of N,N‐dimethyl‐N‐cetyl‐N‐(2‐hydroxyethyl)ammonium chloride salt as surfactant, have shown an efficient activity for the catalytic hydrogenation of various aromatic derivatives in biphasic media under mild conditions. These nanocatalysts can be reused for further runs with a total conservation of activity and provided significant catalytic lifetime for anisole hydrogenation in pure water with 3000 total turn‐over (TTO).
Recycling Chiral Imidazolidin‐4‐one Catalyst for Asymmetric Diels–Alder Reactions: Screening of Various Ionic Liquids
Authors: Park Jin Kyoon , Sreekanth Pentlavalli , Kim B. Moon
Published: February 2004

Various imidazolium ionic liquids such as [Bmim]PF6, [Bmim]SbF6, [Bmim]OTf and [Bmim]BF4 were screened for recycling an organic catalyst [(5S)‐5‐benzyl‐2,2,3‐trimethylimidazolidin‐4‐one (1)] for asymmetric Diels–Alder reactions. Good yields and enantioselectivies (up to 85% yield and 93% ee) were obtained from reactions in [Bmim]PF6 or [Bmim]SbF6. However, reactions in [Bmim]OTf or [Bmim]BF4 gave racemic products in low yields. Isolation of the products by simple extraction using diethyl ether allowed recycling of the ionic liquid containing the immobilized catalyst in subsequent reactions without significant decrease of yields and enantioselectivities.
Simple Biocatalytic Access to Enantiopure (S)‐1‐Heteroarylethanols Employing a Microbial Hydrogen Transfer Reaction
Authors: Stampfer Wolfgang , Edegger Klaus , Kosjek Birgit , Faber Kurt , Kroutil Wolfgang
Published: February 2004

Lyophilised cells of various Rhodococcus spp. were employed in an efficient hydrogen transfer‐like process for the asymmetric bioreduction of heteroaryl methyl ketones using 2‐propanol as hydrogen donor. Besides the genus Rhodococcus, only Mycoplana rubra R14 showed a comparable stability towards elevated concentrations of the co‐substrate 2‐propanol. Among the organisms tested, Rhodococcus ruber DSM 44541 and DSM 43338 showed best activity and selectivity. With these strains, the reaction proceeded with high stereoselectivity (ee>99%) and predictable stereochemical outcome regardless of the nature of the heteroaromatic ring system. The reaction could be performed at the exceptional substrate concentration of up to 0.4 mol L−1 in an environmentally friendly aqueous‐organic solvent mixture at room temperature and is easy to handle, thus providing a very practical tool to access enantiopure 1‐heteroarylethanols.
Efficient Halogenation of Aromatic Systems Using N‐Halosuccinimides in Ionic Liquids
Authors: Yadav J. S. , Reddy B. V. S. , Reddy P. S. R. , Basak A. K. , Narsaiah A. V.
Published: February 2004

A simple, rapid and highly regioselective green protocol has been developed for the halogenation of aromatic systems with N‐halosuccinimides using room temperature ionic liquids (ILs) as novel and recyclable reaction media to produce the corresponding halogenated aromatic compounds in high to quantitative yields. N‐Halosuccinimides show enhanced reactivity in ionic liquids thereby reducing the reaction times dramatically and improving the yields substantially.
Results of Long‐term Sediment Quality Studies on the River Elbe
Authors: Heininger Peter , Pelzer Jürgen , Claus Evelyn , Pfitzner Steffi
Published: February 2004

The results of long‐term studies in the Upper and Middle Elbe River between 1991 and 2001 are presented and the temporal and spatial trends in sediment contamination and toxicity are studied. Although the concentrations of heavy metals and arsenic have significantly decreased in the last 10 years for most of the toxic elements they are still far from natural background values. For organic priority pollutants increasing as well as decreasing trends are observed, depending on the Elbe reach and/or the parameter under consideration. Elbe sediments have a permanent measurable toxicity. It is usually low in terms of aquatic tests as far as the persisting hot spots are not considered. Whole sediment testing with nematode Caenorhabditis elegans which was started in 1997 revealed clear toxic effects. In contrast to the priority pollution situation, no significant trend could be found in general sediment toxicity between 1992 and 2001.