bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arthroscopic posterior cruciate ligament reconstruction: one‐ vs. two‐tunnel technique
Authors: Houe Thomas , Jørgensen Uffe 
Published: December 2004

As the techniques of arthroscopic surgery have evolved, so have the possibilities of reconstructing the posterior cruciate ligament (PCL). However, the indications for this procedure have been debated. We describe the results of reconstructing the PCL in 16 consecutive patients with chronic knee instability due to isolated PCL deficiency using either a patella bone–tendon–bone (pBTB) graft with proximal fixation in one femoral tunnel or double bundle hamstring grafts in two femoral tunnels. The patients were followed prospectively and had an additional evaluation after median 35 (25–51.5) months by a blinded observer. The objective stability and subjective scores increased significantly from the preoperative condition. There were no statistically significant differences in outcome between using a pBTB graft in one femoral tunnel compared with semitendinosus/gracilis grafts in two femoral tunnels.We conclude that arthroscopic reconstruction of isolated PCL ruptures improves the activity level of patients and relieves symptoms. In our study, no difference in outcome between the two techniques could be found.
Antibiotic Lock Technique: A Review of the Literature
Authors: Segarra-Newnham Marisel , Martin-Cooper Ellen M 
Published: December 2004

OBJECTIVE: To review the literature on the use of the antibiotic lock technique (ALT) as a treatment option for patients with highly needed catheters. DATA SOURCES: MEDLINE and International Pharmaceutical Abstracts were searched (1980–August 2004). Search terms included antibiotic lock, catheter infection, and topical treatment. STUDY SELECTION AND DATA EXTRACTION: Articles describing use of ALT in the treatment of catheter infections in humans and studies evaluating in vitro stability of antibiotics were included. DATA SYNTHESIS: ALT has been used in patients with highly needed catheters, usually for parenteral nutrition, cancer chemotherapy, or dialysis. Catheters are considered highly needed when removal is not feasible or desirable due to lack of alternative injection sites for required therapy. Success rates in saving the infected catheter have been variable and may depend on the infecting organism. In addition, there are conflicting data in terms of compatibility of antibiotics with heparin solutions. CONCLUSIONS: Consensus appears to be that the ALT can be tried for patients with highly needed catheters when infection with coagulase-negative staphylococci is documented and no systemic signs of sepsis, such as hypotension, are evident. Most of these patients are likely to need systemic therapy as well. Infection of the catheter associated with systemic gram-negative bacteremia or fungemia will most likely require removal of the catheter to prevent systemic complications. Additional research with the ALT is warranted given unanswered questions.
Rectifying junctions based on metallophthalocyanine thin films
Authors: Pietro William J. 
Published: December 2004

The unusual electrical properties of metallophthalocyanines (M(Pc)S) have made them the centerof much interest recently, in particular as candidates for the fabrication of novel molecularelectronic devices.M(Pc)‐basedrectifiers have been known for 20 years, but now a new non‐Schottky‐type of rectification has been discovered in a junction consisting of Ni(Pc) and Cu(PcF8), see Figure. A brief look is also taken at M(Pc)‐based transistorsand future developments. magnified image
Langmuir films of monodisperse 0.5 μm spherical polymer particles with a hydrophobic core and a hydrophilic shell
Authors: Fulda Karl‐Ulrich , Tieke Bernd 
Published: December 2004

Densely packed monolayers of spherical polymer particles are expected to show interesting materials properties, e.g. a high permeability. It is demonstrated that relatively close‐packed Langmuir films of monodisperse 0.5 μm particles—with a hydrophilic shell and hydrophobic core—can be formed at the air‐water interface and transferred to solid substrates (see Figure) by the subphase‐lowering or Langmuir‐Blodgett technique. magnified image
Interpreting STM and AFM Images
Authors: Magonov Sergei N. , Whangbo Myung‐Hwan 
Published: December 2004

AbstractThe necessity for a rational interpretation of scanning tunneling microscopy (STM) and atomic force microscopy (AFM) images is demonstrated by our recent STM/AFM studies of layered transition‐metal chalcogenides, layered transition‐metal halides, organic conducting salts, and alkanes adsorbed on graphite. To a first approximation, the STM image of a surface is described by the partial density plot ρ(r0, ef) of the surface, and the AFM image by the total density plot ρ(r0). The contribution of an atom to the ρ(r0, ef) plot increases with decreasing distance to the tip and with increasing electronic contribution to the energy levels around the Fermi level. Since the atoms that protrude more do not necessarily make greater contributions to the energy levels near the Fermi level, it is difficult to achieve a rational interpretation of STM images unless appropriate partial density plots are calculated. For a variety of layered compounds, the STM and AFM images are well simulated by the ρ(r0, ef) and ρ(r0) plots calculated by the extended Hückel tight‐binding electronic band structure method. Partial and total density plot calculations provide not only a basis for a rational interpretation of ideal STM and AFM images but also a step toward systematic studies of how tip–surface interactions and tunneling conditions affect the images.
Spiroconjugation: An added dimensi in the design of organic molecular materials
Authors: Maslak Przemyslaw 
Published: December 2004

Molecules with predictable electrical, optical, and magnetic properties are required for molecular devices and new materials. One approach to overcoming the disadvantages associated with the quasi‐one‐dimensional π‐conjugated acceptors and donors that have played a big part so far is to use spiroconjugated molecules that are conjugated but not planar. The concepts behind acceptors such as that shown in the Figure are explained. magnified image
Surface nano‐topography of drawn polyethylene and its modification using scanning force microscopy
Authors: Wawkuschewski Alexander , Cantow Hans‐Joachim , Magonov Sergei N. 
Published: December 2004

Scanning force microscopy (SFM) of oriented polyethylene reveals additional structural details that are not accessible by other techniques. For example, the Figure show that, in addition to the main fibrillar features, there exist nanofibrils oriented perpendicular to the stretching direction. The unique contribution of SFM result to studies of the structural hierarchy of oriented polymers is discussed. magnified image
New polyether‐based ionoselective materials
Authors: Dunjic Branko , Favre‐Réguillon Alain , Duclaux Olivier , Lemaire Marc 
Published: December 2004

The need to separate metalions form various media has led to a demand for ionoselective materials. One approach is to attach specific ligands to a polymeric carrier. The synthesis of the monomer show and its polymeriztion by tow different methods are reported. The cation bingding properties of the resulting polyether‐supported macrocycles as determined by competitive extraction of five alkali metal cations are described. magnified image
Membranes exhibiting molecular recognition
Authors: Bamford Clement H. , Al‐Lamee Kadem G. 
Published: December 2004

Membranes with molecular recognition properties find applications in affinity separations and immunodiagnosis. The Figure illustrates the structure typical of the electrostatically spun polymer membranes considered here. The natural species that can be attached to a membrane–and their uses–are described, and it is shown that completely synthetic systems are useful for studying the details of the recognition process. magnified image
The observation of polymer reptation
Authors: Sackmann Erich , Käs Josef , Strey Helmut 
Published: December 2004

AbstractDirect visualization of reptating macromolecules has been achieved. The concept of reptation, which until recently had only been directly confirmed by computer simulations, is now supported by two separate experiments. In one, a few fluorescencelabeled actin filaments were directly observed in an unlabeled semi‐dilute entangled network. The Figure shows snapshots of a filament moving in the network.
magnified image
Magnetic properties of ferrocene‐based conjugated polymers
Authors: Hmyene Mohamed , Yassar Abderrahim , Escorne Marcel , Percheron‐Guegan Annick , Garnier Francis 
Published: December 2004

A novel route to organic ferromagnetic materials is proposed that is based on the stability of spin‐containing organometallic moieties such as ferricenium and the electronic or topological interactions contributed by a polymer. The magnetic properties of the new high‐spin polymers (see Figure) are shown to be sensitively dependent on the chemical nature of the bridge linking the ferricenium units. magnified image
Junction electroluminescence from microscopic diode structures in CuInSe2, prepared by electric field‐assisted doping
Authors: Chernyak Leonid , Jakubowicz Abram , Cahen David 
Published: December 2004

Light emitting diodes where the efficiency of the junction electroluminescence has been improved over devices fabricated using thermal in‐diffusion methods, is demonstrated for structures such as that shown in the figure, which is an electric‐field‐induced device. As E‐field produced transistors are already available, combined monolithic LED/transistor structures produced using E‐field‐Induced doping of semiconductors could be possible. magnified image
Bimetallic Fe/Ga thin films from single sources; molecular control of the thin film stoichiometry
Authors: Fischer Roland A. , Miehr Alexander , Schulte Markus M. 
Published: December 2004

Single source CVD precursors for FeGa thin films (e.g. see Fig.) are reported. The precursors are volatile, give clean deposits, and allow the use of unprecedented mild deposition conditions, at temperatures well below the decomposition temperature of the GaAs substrate. It is also shown that single‐source precursors for binary materials should be designed with the strongest bond joining the atoms which make up the final material. magnified image
On the conjugation length in poly(para‐phenylene)‐type polymers
Authors: Grimme Julian , Kreyenschmidt Martin , Uckert Frank , Müllen Klaus , Scherf Ullrich 
Published: December 2004

The study of well‐defined, monodisperse model PPP oligomers (e.g. see Figure) has revealed that, contrary to expectations, the planarization of the π system in these oligomers leads to a decrease in the effective conjugation length. This result has profound influence on the design of conducting organic materials. magnified image
Promising new precursors for the CVD of gold
Authors: Jansen Frank , Kruck Thomas 
Published: December 2004

High deposition rates for the CVD of gold at low temperatures are reported. The synthesis and use of methyl(alkyldimethoxyphosphine)gold(I) compounds in the chemical vapor deposition of gold (see Figure) is described, and the precursors are found to be easily handled in air, and to result in comparable deposition rates and higher yields compared to currently used materials. magnified image
Polymerization of 10,12‐docosadiyne‐1,22‐ disulfate in self‐assembled multilayers
Authors: Saremi Farnaz , Tieke Bernd 
Published: December 2004

The polymerization of diacetylenes in self‐assembled multilayers (see Figure) should lead to a new type of ultrathin films exhibiting interesting optical and electronic properties. Here the preparation of water‐soluble diacetylene derivatives, multi‐layer formation, and the UV polymerization of the derivatives are reported. magnified image
Molecular nanoclusters as precursors to conductive thin films and crystals
Authors: Hillier Andrew C. , Hossick Schott Joachim , Ward Michael D. 
Published: December 2004

The role of epitaxy and orientation in the morphologies of thin films of organic conductors such as TTF‐TCNQ (see Figure) is discussed. It is found that the anisotropy and direction of molecular bonding with respect to the interface, as well as interfacial interactions have a profound effect on the growth of the thin films. magnified image
Semiconductor nanotube formation by a two‐step template process
Authors: Hoyer Patrick 
Published: December 2004

Multistep template synthesis offers an easy and general route to complicated nanostructures. A two‐step replication procedure is described that can be used to prepare nanotubes of titanium dioxide (see Figure) or other semiconducting materials. The requirements placed on the starting material, the synthesis route, and the TiO2 deposition mechanism are considered and filling of the tubes is briefly discussed. magnified image
Rapid prototyping of complex structures with feature sizes larger than 20 μm
Authors: Qin Dong , Xia Younan , Whitesides George M. 
Published: December 2004

A rapid, low‐cost technique of microfabrication for feature sizes of 20 μm or more is described, which is useful for the rapid production of limited numbers of microsensor and optical structures. The pattern can be designed on a PC and printed out on transparent films of polymers using a commercial image‐setting system. The Figure shows an SEM image of a relief pattern generated on photoresistant film using this method. magnified image
Dyeing salt crystals for optical applications
Authors: Kahr Bart , Jang Sei‐Hum , Subramony J. Anand , Kelley Michael P. , Bastin Loyd 
Published: December 2004

Inorganic materials can encapsulate organic dye molecules in a variety of ways. Those considered here are simple inorganic salts that have adsorbed, oriented, and overgrown dyes during growth from solution, which promise spectroscopic and photonic applications. The Figure shows KH2PO4 crystals in which dyes carrying sulfonate or phosphate groups have been incorporated in the {101} growth sectors (see also the cover of this issue). magnified image
The design and synthesis of Heterogeneous Catalyst Systems
Authors: Herron Norman , Farneth William E. 
Published: December 2004

A Maxwell's Demon approach to catalysis, in which individual molecules can be distinguished, has come closer to reality in recent years. Two new approaches to catalyst synthesis are described that are leading the way to catalyst design. The Figure shown n‐octane proceeding through the 8‐ring window of zeolite A toward the iron active site for oxidation. The relative size of the window and alkaline causes selectivity for oxidation towards the end of the chain. magnified image
Efficient blue‐light emitting devices from conjugated polymer blends
Authors: Birgerson Jonas , Kaeriyama Koji , Barta Piotr , Bröms Per , Fahlman Mats , Granlund Thomas , Salaneck William R. 
Published: December 2004

A polymer light‐emitting device with an external quantum efficiency of 2%, one of the highest values in polymer‐based devices reported to date, had been fabricated from a blend of PDHPT (see Figure) and PDPP (poly(2,5‐diheptyl‐2′,5′‐dipentoxybiphenylene)). The optical properties of the polymers and the device are presented. A particularly important point is the processability of the active media. magnified image
A new method for the preparation of conductive polyaniline solutions: Application to liquid crystal devices
Authors: Harlev Eli , Gulakhmedova Tamila , Rubinovich Ilia , Aizenshtein Gentadi 
Published: December 2004

Transparent “all‐polymer” electrodes are promising candidates for applications in LCDs and LEDs and LEDs. A novel approach for making a new polyaniline‐based polymer is described, efficient solubilization of the conductive from of polyaniline is reported, and use of the resulting conductive polymer solutions for LCDs demonstrated. The Figure shows a bent polymer‐dispersed LCD with transparent “all‐polymer” electrodes in the “on” (transparent) state. magnified image
Oligo(siloxane) rings and cages possessing nickel‐containing liquid crystal side chains
Authors: Saez Isabel M. , Styring Peter 
Published: December 2004

A liquid‐crystalline coordination compound immobilized on an oligomeric superstructure free from cross‐linking (see Figure) is reported for the first time. A highly versatile synthetic methodology is described that allows unsymmetrical, mono‐functionalized, metal‐containing liquid‐crystalline coordination complexes to be prepared. Related materials may find uses as novel catalysts. magnified image
Oriented growth of molecular sieves on inorganic membranes
Authors: Wu Chih‐Ning , Chao Kuei‐Jung , Tsai Tzeng‐Guang , Chiou Yuan‐Horng , Shih Han‐Chang 
Published: December 2004

A molecular sieve film with vertically oriented and closely packed crystals has been prepared by a novel method. The Figure shows VAP4‐5 (zeolite‐like) crystals anchored inside the straight channel walls of an anodic alumina membrane. The novel method of synthesis is outlined and the effect of varying the growth conditions, e.g., temperature, solution dilution, chemical composition, reactant source, described. magnified image
Metal nanoparticle/polymer superlattice films: Fabrication and control of layer structure
Authors: Schmitt Johannes , Decher Gero , Dressick Walter J. , Brandow Susan L. , Geer Robert E. , Shashidhar R. , Calvert Jeffrey M. 
Published: December 2004

Multilayer superlattices incorporating colloidal metal nanoparticles have been synthesized by an approach based on self‐assembly. Teh method of synthesis is described and the results are presented from X‐ray reflectivity measurements, optical spectroscopy, and various microscopies, showing that they provide a consistent picture of the structure of the resulting multilayer superlattices (see Figure). fig.magnified image
Laser Ablation of Doped Polymer Systems
Authors: Lippert Thomas , Yabe Akira , Wokaun Alexander 
Published: December 2004

AbstractLaser ablation has become a widely recognized tool for materials processing. In the area of polymeric materials, applications of UV lasers for surface modification, microlithography, cutting, and boring have been explored. With the addition of dopants into the bulk, it has become possible to sensitize most known classes of polymers for UV laser ablation at any desired wavelength, including fluoropolymers. Important features of dopant‐induced ablation are the reduction of threshold energy fluence required for ablation, and the enhancement of the etching rate by factors higher than ten. In the present review the investigated dopant/polymer systems are summarized and compared. Based on the available information, a general scheme including all relevant pathways is suggested, revealing that in each particular case the dominant mechanism depends on the specific system under study.
An improved experimental determination of external photoluminescence quantum efficiency
Authors: de Mello John C. , Wittmann H. Felix , Friend Richard H. 
Published: December 2004

The external photoluminescence quantum yield of, for example, thin film semiconductors can be conveniently determined using the improved integrating‐sphere method (see Figure) presented here. Spectrally resolved detection allows the excitation source and the emission to be distinguished. The method will be particularly useful for samples with small Stocks' shifts or low photoluminescence quantum yields or for highly scattering samples. Figmagnified image
5, 5″‐Bis{4‐[bis(4‐methylphenyl)amino]phenyl}2, 2′:5′, 2″‐terthiophene and 5, 5‴‐bis{4‐[Bis(4‐methylphenyl)amino]phenyl}2, 2′:5′, 2″:5″, 2‴‐quaterthiophene as a Novel Family of Amorphous Molecular Materials
Authors: Noda Tetsuya , Imae Ichiro , Noma Naoki , Shirota Yasuhiko 
Published: December 2004

A novel family of photo‐and electroactive amorphous molecular materials containing an oligothiophene moiety linked to two triphenylamine moieties has been designed and synthesized (see Figure). Their glass‐forming properties, morphological changes, and molecualr and solid‐state properties are described. They are reported to exhibit multiredox behavior on electrochemical oxidation. magnified image
Fabrication of polymeric microstructures with high aspect ratios using shrinkable polystyrene films
Authors: Zhao Xiao‐Mei , Xia Younan , Qin Dong , Whitesides George M. 
Published: December 2004

High‐aspect‐ratio polymeric structures have been fabricated using a process that combines reactive ion etching (RIE) and stress‐oriented, shrinkable polystyrene films. It is reported how, after pattering of the surface of the polystyrene film by RIE, heating of the film caused it to shrink by a factor of 4–5 in the lateral dimensions while the thickness of the film and the features on it increased by a factor of ∼20 (see Figure). Fig.magnified image
Progress and perspectives in solar energy conversion
Authors: Kuwano Yukinoro 
Published: December 2004

AbstractPhotovoltaic (PV) power generation can surely be considered a critical technol‐ ogy for overcoming global environmental problems and energy problems. This essay will review the current status and application technologies of PV power gene‐ ration, concluding with a discussion of the prospects of a future global‐scale energy supply system based on PV power generation.
Magnetic properties of nitronyl nitroxide radicals substituted in phenylboronic acid the BOH ⃛O hydrogen bond as a constituent unit of a one‐dimensional suprastructure exhibiting a ferromagnetic spin interaction
Authors: Akita Takeyuki , Kobayashi Keiji 
Published: December 2004

The NO…︁HOB hydrogen bond has recently been shown to play a role as an intermolecular ferromagnetic spin coupler. Studies of this bound in phenylboronic acid derivatives substituted by the nitronyl nitroxide radical moiety are presented, in particular the synthesis, crystal structure, and magnetic properties of the para‐substituted phenylboronic acid shown in the Figure and the corresponding meta compound. Boronic acid derivatives bearing the NO radical center are shown to be promising precursors for molecular magnetic materials. magnified image
Microlithographic process for patterning conjugated emissive polymers
Authors: Renak Michelle L. , Bazan Guillermo C. , Roitman Daniel 
Published: December 2004

The spatially confined synthesis of emissive conjugated polymers—compatible with existing 1C fabrication technology—is described, which can be used to create well‐defined micrometerscale patterned organic LEDs (see cover). The Figure shows the first step in the photolithographic process, which is followed by irradication, to produce a latent image, and development, resulting in patterned polymer. magnified image
Surface chemistry of Luminescent Silicon Nanocrystallites
Authors: Sailor Michael J. , Lee Eric J. 
Published: December 2004

The rational modification of porous and single‐crystalline silico surfaces is of particular interest for technologies based on silicon. Porous silicon, such as the layer shown in the Figure, has many potential technological applications. In this review of chemical reactions developed for Si surface modification, both extensions of the chemistry of molecular Si compounds to surfaces and new surface chemistry are treated. magnified image
Ultrathin cellulose ether network as a host matrix for alkylthiophene polymerization
Authors: Henry Christelle Denise , Tebbe Heiko , Wegner Gerhard , Arrnand Frank , Ruaudel‐Teixier Annie 
Published: December 2004

New insights into the mechanism of chain growth and phase formation in electropolymerization are expected from the work on ultrathin films described here. The Figure shows that the very rapid electrochemical polymerization of a thiophene derivative that occurs inside a multilayered assembly of a cellulose derivative on an electrode can be used as the basis of an imaging process. magnified image