bluuebunny/crossref_metadata_2025 huggingface dataset:
Silica
Authors: Uhrlandt Stefan
Published: June 2006

In recorded history, there are numerous indications of the omnipresence of silicates in humanity’s natural habitat. Siliceous minerals were either utilized by processing natural silica deposits, eg, clay, porcelain, glass or enamel, or obtained by means of chemical conversion. Silica in the form of amorphous white powders can also be made synthetically, using a thermal process (fumed silica) or a wet process (precipitated silica, silica gels). Forms of amorphous silica are used in various industries, such as food, feed, coatings, plant protection, tires, personal care, and many others, and are an essential part of many products of our everyday life.

This article briefly covers crystalline silica. The major focus is amorphous silica, its production processes, physical‐chemical characteristics, and uses in various everyday products. Health and safety aspects are also discussed.
Silylating Agents
Authors: Pape Peter G.
Published: June 2006

Silylating agents are used to replace active hydrogens from the surface of organic materials by trisubstituted silyl groups. This procedure is effected for a variety of reasons. Simple organic compounds may be silylated for purposes of synthesis and analysis; inorganic mineral surfaces may be silylated for purposes of analysis, adhesion, and water repellence; metal oxides, glass, resins, enzymes, etc, may be silylated to effect corrosion resistance, antimicrobial activity, immobilization for catalysis, chromatography column material, waterproofing, etc. The various compounds and the methods utilized for silylation are discussed.
Sulfur Compounds
Authors: Weil Edward D. , Sandler Stanley R. , Gernon Michael
Published: June 2006

Sulfur is a component of many industrially useful compounds, particularly process intermediates. Other sulfur compounds are important because of air pollution considerations, coming from natural sources (COS, SO2, H2S) as well as manmade. Carbon sulfides, carbonyl sulfide, thiophosgene, trichloromethanesulfenyl chloride, hydrogen sulfide, hydrogen polysulfides (sulfanes) and their salts, sulfur halides and oxyhalides, sulfur nitrides, sulfur oxides, sulfur oxygen acids and their salts, thiocyanic acid and its salts, methanesulfonyl chloride, and methanesulfonic acid are all discussed, along with properties, manufacture, shipment and storage, economic aspects, analytical methods, grades and specifications, health and safety, and uses in making agricultural pesticides, pharmaceuticals, food chemicals, oil additives, plastics and plastic additives, and refining catalysts. Elemental sulfur, sulfuric acid, sulfur trioxide, carbon disulfide, thiosulfates and sulfur removal from natural gas are discussed in separate articles in thisEncyclopedia.
Porphyrin profiles in blood, urine and faeces by HPLC/electrospray ionization tandem mass spectrometry
Authors: Danton Malcolm , Lim Chang Kee
Published: June 2006

A high‐resolution high‐performance liquid chromatography/electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry method is described for the analysis of porphyrins in blood, urine and faeces. The gradient elution reversed‐phase HPLC system using acetonitrile–methanol–1 m ammonium acetate/acetic acid buffer (pH 5.16) as gradient solvent mixtures was able to separate all porphyrin metabolites, including the type I and type III isomers of uroporphyrin, hepta‐, hexa‐ and penta‐carboxylic acid porphyrins and coproporphyrin. The porphyrins were positively identified by the protonated molecules [M+H]+ and further characterized by tandem mass spectrometric analysis with each porphyrin giving a characteristic collisioninduced dissociation product ion spectrum. The mass chromatograms obtained by HPLC/ESI MS are useful for the differential diagnosis of the porphyrias, since each type of porphyria has a typical porphyrin excretion pattern. Copyright © 2006 John Wiley & Sons, Ltd.
Quantification of MDMA and MDA in abusers' hair samples by semi‐micro column HPLC with fluorescence detection
Authors: Nakamura Shinichi , Tomita Mamoru , Wada Mitsuhiro , Chung Heesun , Kuroda Naotaka , Nakashima Kenichiro
Published: June 2006

A sensitive semi‐micro column high‐performance liquid chromatography with fluorescence detection method was developed for the determination of 3,4‐methylenedioxymethamphetamine (MDMA), 3,4‐methylenedioxyamphetamine (MDA), methamphetamine (MP) and amphetamine (AP) in human hair. 4‐(4,5‐Diphenyl‐1H‐imidazol‐2‐yl)benzoyl chloride (DIB‐Cl) and 1‐methyl‐3‐phenylpropylamine were used as labeling reagent and internal standard, respectively. These drugs were extracted from hair into 5% trifluoroacetic acid in methanol, and fluorescent labeled with DIB‐Cl. The separation of DIB‐derivatives was achieved on a reversed‐phase semi‐micro ODS column with an acetonitrile–methanol–water (30:40:30, v/v/v%) mixture as a mobile phase. The limits of detection at a signal‐to‐noise ratio of 3 for MDMA, MDA, MP and AP were 0.25, 0.15, 0.25 and 0.19 ng/mg, respectively. Precision of intra‐ and inter‐day assay as the relative standard deviation were in the range 1.5–6.8% (n = 5) and 2.7–4.7% (n = 5), respectively. The proposed method was highly sensitive and able to detect MDMA and its related compounds in small amounts of hair sample, and could be applied to quantification of six abusers' hair samples. Copyright © 2006 John Wiley & Sons, Ltd.
Alterations of plasma and cerebrospinal fluid glutamate levels in rats treated with theN‐methyl‐D‐aspartate receptor antagonist, ketamine
Authors: Tomiya Masayuki , Fukushima Takeshi , Kawai Junko , Aoyama Chiaki , Mitsuhashi Shogo , Santa Tomofumi , Imai Kazuhiro , Toyo'oka Toshimasa
Published: June 2006

It has been reported that the repeated administration of a sub‐anesthetic dose of anN‐methyl‐D‐aspartate receptor antagonist, ketamine, can produce an animal model of schizophrenia. Since no information is available on the alterations of the amino acid levels in ketamine‐treated rats, we investigated the amino acid composition in the plasma and cerebrospinal fluid of rats that were repeatedly administered with ketamine for 5 consecutive days (30 mg/kg/day). The plasma and cerebrospinal fluid amino acid compositions in the fifth week after cessation of repeated ketamine administration were determined by highperformance liquid chromatography with fluorescence detection using a pre‐column fluorescence reagent, i.e. 4‐fluoro‐7nitro‐2,1,3‐benzoxadiazole. Among the amino acids investigated in the present study, the level of plasma glutamic acid increased significantly (p< 0.05), while that of the cerebrospinal fluid glutamic acid decreased significantly in the ketamine‐treated rats as compared with these levels in control rats injected with saline (p< 0.05,n= 7). These alterations in the glutamic acid level in the plasma and cerebrospinal fluid resemble those in schizophrenic patients, suggesting that ketamine‐treated rats may be a useful model for performing research on the pathophysiology of schizophrenia. Copyright © 2006 John Wiley & Sons, Ltd.
The value of knowledge for colour design
Authors: Green‐Armytage Paul
Published: June 2006

Colour is not one single kind of “thing.” Here I propose a way of categorizing the different kinds of thing that colours are variously understood to be. I further propose that the means used to identify a colour determine what kind of thing it is that is being identified. My proposed categories are conventional colour, substance colour, formula colour, spectral profile colour, psychophysical colour, inherent colour, and perceived colour. I show how these different kinds of colour are the concern of people working in different disciplines and that these different disciplines all contribute knowledge that can be of value in colour design. I also show how recognition of the different kinds of colour can help designers to a clearer understanding of concepts that they use in their own discipline. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 253–269, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20222
Rejuvenating the color palette of Georges Seurat's A Sunday on La Grande Jatte—1884: A simulation
Authors: Berns Roy S. , Byrns Siobhan , Casadio Francesca , Fiedler Inge , Gallagher Christopher , Imai Francisco H. , Newman Alan , Taplin Lawrence A.
Published: June 2006

Georges Seurat first employed his divisionist painting technique, commonly called pointillism, on A Sunday on La Grande Jatte—1884 beginning in October 1885. Painting with pigments representing colors seen in the visible spectrum that were minimally mixed on the palette and using divided brushstrokes, he aimed to impart “luminosity” to the surface and to explore color theories that were being developed and disseminated at that time, such as simultaneous contrast, in his unique interpretation. In addition to the natural ageing of the painting materials causing an overall darkening of the painting, pigment analysis has disclosed that the brushwork containing zinc yellow has darkened significantly: yellow, green–yellow, and orange brushstrokes have become ochre‐like, olive–green, and reddish–brown, respectively. By performing spectral reflectance measurements in situ on darkened areas of the painting and on paint‐outs of comparable unaltered colors, using Kubelka–Munk turbid media theory, imaging the painting with color‐managed digital photography, and image editing with Adobe Photoshop, a digital version of the original, more luminous appearance of La Grande Jatte was simulated. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 278–293, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20223
Appearance reproduction and multispectral imaging
Authors: Tsumura Norimichi
Published: June 2006

With the recent progress of broadband networks, accurate appearance reproduction across various environments is required for objects in various applications such as e‐commerce, the designing process, and telemedicine. Multispectral imaging techniques are expected to perform cross‐environment color reproduction for objects. However, color is just one attribute for the appearance of objects. Other attributes such as glossiness, graininess, and translucency should be also considered for practical cross‐environment appearance reproduction. In this review, a framework for appearance reproduction is introduced with relation to computer graphics, computer vision, and image processing techniques. The importance of the multispectral imaging technique is also recognized again in this framework. Case studies are introduced based on the examples we have performed in our practical applications. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 270–277, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20225
Color and symbolic meaning of elements in nature
Authors: Kim Young‐In
Published: June 2006

Colors effectively communicate visual images, enabling the association of ideas and symbolic meanings based upon individual senses and experiences. The premise of this study is that colors stimulate interest in the aesthetics and significance of nature when they are applied to nature. Thus, the goal of this study is to convey the importance of nature through the colors of the four elements: air, water, earth, and fire. This article analyzes the application of colors and symbolic meanings of the four elements in art history, paintings, and fashion trends and examines whether they effectively represent nature. Finally, the four elements are represented by four color palettes. These colors may convey the image of nature and play an important role in shaping people's values that form aesthetic awareness and interests in nature. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 341–349, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20232
Corporate social responsibility in host countries: a perspective from American managers
Authors: Engle Robert L.
Published: June 2006

This paper examines the beliefs of 56 US‐based senior international business executives regarding the importance of multinational corporations' involvement in the improvement of host countries' human rights, poverty, education, health care and environment. The results of this pilot study suggest that all five areas are considered important, with the environmental responsibilities of MNCs being perceived as the most important of these five areas. Little significant difference was found with regards to the executives' views of importance based on either their having lived overseas or based on the international component of their current job activity, with one exception: those executives with more than 50% of their job involving international activities believed that MNCs had a significantly greater environmental responsibility in host countries than did those with less job‐related international activity. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Obscurin is required for the lateral alignment of striated myofibrils in zebrafish
Authors: Raeker Maide Ö. , Su Fengyun , Geisler Sarah B. , Borisov Andrei B. , Kontrogianni‐Konstantopoulos Aikaterini , Lyons Susan E. , Russell Mark W.
Published: June 2006

Obscurin/obscurin‐MLCK is a giant sarcomere‐associated protein with multiple isoforms whose interactions with titin and small ankyrin‐1 suggest that it has an important role in myofibril assembly, structural support, and the sarcomeric alignment of the sarcoplasmic reticulum. In this study, we characterized the zebrafish orthologue of obscurin and examined its role in striated myofibril assembly. Zebrafish obscurin was expressed in the somites and central nervous system by 24 hours post‐fertilization (hpf) and in the heart by 48 hpf. Depletion of obscurin using two independent morpholino antisense oligonucleotides resulted in diminished numbers and marked disarray of skeletal myofibrils, impaired lateral alignment of adjacent myofibrils, disorganization of the sarcoplasmic reticulum, somite segmentation defects, and abnormalities of cardiac structure and function. This is the first demonstration that obscurin is required for vertebrate cardiac and skeletal muscle development. The diminished capacity to generate and organize new myofibrils in response to obscurin depletion suggests that it may have a vital role in the causation of or adaptation to cardiac and skeletal myopathies. Developmental Dynamics 235:2018–2029, 2006. © 2006 Wiley‐Liss, Inc.
Toward a global picture of development: Lessons from genome‐scale analysis in Caenorhabditis elegans embryonic development
Authors: Ge Hui , Player Christopher M. , Zou Lihua
Published: June 2006

Development is the result of complex events, including cascades of transcriptional programs and numerous molecular interactions. Traditionally, research focus has been given to the characterization of individual mutants, regulators, or interactions. With the availability of complete genome sequences and high‐throughput (HT) experimental techniques, probing development on a system level has become feasible. Pioneering work initiated in invertebrate model systems such as Caenorhabditis elegans has provided first drafts of catalogs of essential components, transcriptional regulatory diagrams and molecular interaction networks underlying developmental processes. Integrating these drafts approximates a system‐level picture of development and provides local models for protein/gene functions. Here we summarize the progress toward elucidating developmental processes on a system level, including the applications of genomic technologies and computational analyses. We discuss C. elegans embryonic development in case studies to illustrate how various HT approaches can be integrated and how biological insights can be gained from these approaches. Developmental Dynamics 235:2009–2017, 2006. © 2006 Wiley‐Liss, Inc.
The input–output weight enumeration of binary Hamming codes
Authors: Loskot Pavel , Beaulieu Norman C.
Published: June 2006

We show that binary Hamming codes can be constructed recursively. The recursive structure is used to efficiently enumerate the input–output weights. Hence, the bit error rate of binary Hamming codes with antipodal signalling and hard‐decision demodulation used on additive white Gaussian noise channels can be evaluated exactly. The numerically computed coding gain of Hamming codes reveals a surprising fact that the coding gain is not monotonically increasing with signal‐to‐noise ratio. Copyright © 2006 AEIT
Analysis of integrated power control and advanced receivers algorithms
Authors: Novakovic Dejan M. , Dukic Miroslav L.
Published: June 2006

Integrated power control algorithms with advanced receivers like adaptive antenna arrays and multiuser detectors have significantly better performance than conventional power control algorithms with matched filters. However, these algorithms are very complex for practical implementation and their significant performance gains were only shown in idealised conditions. In this paper, we study the performance of integrated power control and advanced receivers algorithms for WCDMA uplink that are modified to be more suitable for practical implementation. We simultaneously take into account system imperfections, such as limited bandwidth for power control command, power control command errors, update rate of power control command, delay of power control command, fast fading effects, soft handover, limitation of mobile user minimum and maximum power, etc. Impact of mobile user velocities and errors in filter coefficients determination on performance of the algorithms are also shown. We show that also in this environment, power control algorithms integrated with advanced receivers significantly outperform conventional power control algorithm. Copyright © 2006 AEIT
Bayesian estimation of evoked and induced responses
Authors: Friston Karl , Henson Richard , Phillips Christophe , Mattout Jérémie
Published: June 2006

We describe an extension of our empirical Bayes approach to magnetoencephalography/electroencephalography (MEG/EEG) source reconstruction that covers both evoked and induced responses. The estimation scheme is based on classical covariance component estimation using restricted maximum likelihood (ReML). We have focused previously on the estimation of spatial covariance components under simple assumptions about the temporal correlations. Here we extend the scheme, using temporal basis functions to place constraints on the temporal form of the responses. We show how the same scheme can estimate evoked responses that are phase‐locked to the stimulus and induced responses that are not. For a single trial the model is exactly the same. In the context of multiple trials, however, the inherent distinction between evoked and induced responses calls for different treatments of the underlying hierarchical multitrial model. We derive the respective models and show how they can be estimated efficiently using ReML. This enables the Bayesian estimation of evoked and induced changes in power or, more generally, the energy of wavelet coefficients. Hum Brain Mapp, 2006. © 2006 Wiley‐Liss, Inc.
ATM is activated by mitotic stress and suppresses centrosome amplification in primary but not in tumor cells
Authors: Shen Kate , Wang Yaolin , Brooks S.C. , Raz Avraham , Wang Y. Alan
Published: June 2006

Centrosome amplification has been proposed to contribute to the development of aneuploidy and genome instability. Here, we show that Ataxia‐Telangiectasia Mutated (ATM) is localized to the centrosome and co‐purified with γ‐tubulin. The importance of ATM in centrosome duplication is demonstrated in Atm‐deficient primary mouse embryonic fibroblasts that display centrosome amplification. Interestingly, centrosome amplification was not observed in tumor cell lines derived from Atm and p21 double deficient mouse. Our results also indicate that both p53 and p21 operate in the same pathway as ATM in regulating centrosome biogenesis. Finally, a potential role of ATM in spindle checkpoint regulation is demonstrated by which ATM protein is activated by mitotic stress. These results suggest a role of ATM in spindle checkpoint regulation and indicate that ATM suppresses genome instability and cellular transformation by regulating centrosome biogenesis. J. Cell. Biochem. 99: 1267–1274, 2006. © 2006 Wiley‐Liss, Inc.
High glucose increase cell cycle regulatory proteins level of mouse embryonic stem cells via PI3‐K/Akt and MAPKs signal pathways
Authors: Kim Yun Hee , Heo Jung Sun , Han Ho Jae
Published: June 2006

This study examined the effects of high glucose on cell proliferation and its related signal pathways using mouse embryonic stem (ES) cells. Here, we showed that high glucose level significantly increased [3H]thymidine incorporation, BrdU incorporation, the number of cells, [3H]leucine, and [3H]proline incorporation in a time‐(>3 hr) and dose‐(>25 mM) dependent manner. Moreover, high glucose level increased the cellular reactive oxygen species (ROS), Akt, and mitogen‐activated protein kinases (MAPKs) phosphorylation. Subsequently, these signaling molecules involved in high glucose‐induced increase of [3H]thymidine incorporation. High glucose level also increased cyclin D1, cyclin E, cyclin‐dependent kinase (CDK) 2, and CDK 4 protein levels, which is cell cycle regulatory proteins acting in G1–S phase of cell cycle. Inhibition of phosphatidylinositol 3‐kinase (PI3‐K) (LY 294002: PI3‐kinase inhibitor, 10−6 M), Akt (Akt inhibitor, 10−5 M), and p44/42 MAPKs (PD 98059: MEK inhibitor, 10−5 M) decreased these proteins. High glucose level phosphorylated the RB protein, which was decreased by inhibition of PI3‐K and Akt. In conclusion, high glucose level stimulates mouse ES cell proliferation via the PI3‐K/Akt and MAPKs pathways. J. Cell. Physiol. 209: 94–102, 2006. © 2006 Wiley‐Liss, Inc.
Modular, self‐assembling peptide linkers for stable and regenerable carbon nanotube biosensor interfaces
Authors: Contarino Mark R. , Sergi Mauro , Harrington Adrian E. , Lazareck Adam , Xu Jimmy , Chaiken Irwin
Published: June 2006

As part of an effort to develop nanoelectronic sensors for biological targets, we tested the potential to incorporate coiled coils as metallized, self‐assembling, site‐specific molecular linkers on carbon nanotubes (CNTs). Based on a previously conceived modular anchor‐probe approach, a system was designed in which hydrophobic residues (valines and leucines) form the interface between the two helical peptide components. Charged residues (glutamates and arginines) on the borders of the hydrophobic interface increase peptide solubility, and provide stability and specificity for anchor‐probe assembly. Two histidine residues oriented on the exposed hydrophilic exterior of each peptide were included as chelating sites for metal ions such as cobalt. Cysteines were incorporated at the peptide termini for oriented, thiol‐mediated coupling to surface plasmon resonance (SPR) biosensor surfaces, gold nanoparticles or CNT substrates. The two peptides were produced by solid phase peptide synthesis using Fmoc chemistry: an acidic 42‐residue peptide E42C, and its counterpart in the heterodimer, a basic 39‐residue peptide R39C. The ability of E42C and R39C to bind cobalt was demonstrated by immobilized metal affinity chromatography and isothermal titration calorimetry. SPR biosensor kinetic analysis of dimer assembly revealed apparent sub‐nanomolar affinities in buffers with and without 1 mM CoCl2 using two different reference surfaces. For device‐oriented CNT immobilization, R39C was covalently anchored to CNT tips via a C‐terminal cysteine residue. Scanning electron microscopy was used to visualize the assembly of probe peptide (E42C) N‐terminally labeled with 15 nm gold nanoparticles, when added to the R39C‐CNT surface. The results obtained open the way to develop CNT tip‐directed recognition surfaces, using recombinant and chemically synthesized chimeras containing binding epitopes fused to the E42C sequence domain. Copyright © 2006 John Wiley & Sons, Ltd.
Real‐time monitoring of the membrane‐binding and insertion properties of the cholesterol‐dependent cytolysin anthrolysin O from Bacillus anthracis
Authors: Cocklin Simon , Jost Monika , Robertson Noreen M , Weeks Stephen D , Weber Hans‐Walter , Young Emily , Seal Samar , Zhang Can , Mosser Elise , Loll Patrick J , Saunders Aleister J , Rest Richard F , Chaiken Irwin M
Published: June 2006

Bacillus anthracis has recently been shown to secrete a potently hemolytic/cytolytic protein that has been designated anthrolysin O (ALO). In this work, we initiated a study of this potential anthrax virulence factor in an effort to understand the membrane—binding properties of this protein. Recombinant anthrolysin O (rALO35–512) and two N‐terminally truncated versions of ALO (rALO390–512 and rALO403–512) from B. anthracis were overproduced in Escherichia coli and purified to homogeneity. The role of cholesterol in the cytolytic activity of ALO was probed in cellular cholesterol depletion assays using mouse and human macrophage‐like lines, and also Drosophila Schneider 2 cells. Challenging the macrophage cells with rALO35–512, but not rALO390–512 or rALO403–512, resulted in cell death by lysis, with this cytolysis being abolished by depletion of the membrane cholesterol. Drosophila cells, which contain ergosterol as their major membrane sterol, were resistant to rALO‐mediated cytolysis. In order to determine the molecular mechanism of this resistance, the interaction of rALO with model membranes comprised of POPC alone, or with a variety of structurally similar sterols including ergosterol, was probed using Biacore. Both rALO35–512 and rALO403–512 demonstrated robust binding to model membranes composed of POPC and cholesterol, with amount of protein bound proportional to the cholesterol content. Ergosterol supported greatly reduced binding of both rALO35–512 and rALO403–512, whereas other sterols tested did not support binding. The rALO403–512—membrane interaction demonstrated an equilibrium dissociation constant (KD) in the low nanomolar range, whereas rALO35–512 exhibited complex kinetics likely due to the multiple events involved in pore formation. These results establish the pivotal role of cholesterol in the action of rALO. The biosensor method developed to measure ALO recognition of cholesterol in a membrane environment could be extended to provide a platform for the screening of inhibitors of other membrane‐binding proteins and peptides. Copyright© 2006 John Wiley & Sons, Ltd.
Age‐dependent changes in matrix composition and organization at the ligament‐to‐bone insertion
Authors: Wang I‐Ning E. , Mitroo Siddarth , Chen Faye H. , Lu Helen H. , Doty Stephen B.
Published: June 2006

Injuries to the anterior cruciate ligament (ACL) often occur at the ligament‐to‐bone insertion site; thus, an in‐depth understanding of the native insertion is critical in identifying the etiology of failure and devising optimal treatment protocols for ACL injuries. The objective of this study is to conduct a systematic characterization of the ACL‐to‐bone interface, focusing on structural and compositional changes as a function of age. Using a bovine model, three age groups were studied: Neonatal (1–7 days old), Immature (2–6 months old), and Mature (2–5 years old). The distribution of types I, II, X collagen, decorin, cartilage oligomeric matrix protein (COMP), glycosaminoglycan (GAG), alkaline phosphatase (ALP) activity, and minerals at the ACL‐to‐bone insertion were examined. Additionally, cell aspect ratio, size, and distribution across the insertion were quantified. The ACL‐to‐bone insertion is divided into four regions: ligament, nonmineralized interface, mineralized interface, and bone. Both region‐dependent and age‐dependent structural and compositional changes at the insertion site were observed in this study. The interface in the skeletally immature group resembled articular cartilage, while the adult interface was similar to fibrocartilaginous tissue. Age‐dependent changes in extracellular matrix composition (type X collagen, sulfated glycosaminoglycan), cellularity, ALP activity, and mineral distribution were also found. Marked differences in collagen fiber orientation between the femoral and tibial insertions were observed, and these differences became more pronounced with age. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1745–1755, 2006
Relative contributions of muscle activation and muscle size to plantarflexor torque during rehabilitation after immobilization
Authors: Stevens Jennifer E. , Pathare Neeti C. , Tillman Susan M. , Scarborough Mark T. , Gibbs C. Parker , Shah Prithvi , Jayaraman Arun , Walter Glenn A. , Vandenborne Krista
Published: June 2006

Muscle atrophy is clearly related to a loss of muscle torque, but the reduction in muscle size cannot entirely account for the decrease in muscle torque. Reduced neural input to muscle has been proposed to account for much of the remaining torque deficits after disuse or immobilization. The purpose of this investigation was to assess the relative contributions of voluntary muscle activation failure and muscle atrophy to loss of plantarflexor muscle torque after immobilization. Nine subjects (ages 19–23) years with unilateral ankle malleolar fractures were treated by open reduction‐internal fixation and 7 weeks of cast immobilization. Subjects participated in 10 weeks of rehabilitation that focused on both strength and endurance of the plantarflexors. Magnetic resonance imaging, isometric plantarflexor muscle torque and activation (interpolated twitch technique) measurements were performed at 0, 5, and 10 weeks of rehabilitation. Following immobilization, voluntary muscle activation (56.8 ± 16.3%), maximal cross‐sectional area (CSA) (35.3 ± 7.6cm2), and peak torque (26.2 ± 12.7N‐m) were all significantly decreased ( p < 0.0056) compared to the uninvolved limb (98.0 ± 2.3%, 48.0 ± 6.8 cm2, and 105.2 ± 27.0 N‐m, respectively). During 10 weeks of rehabilitation, muscle activation alone accounted for 56.1% of the variance in torque ( p < 0.01) and muscle CSA alone accounted for 35.5% of the variance in torque ( p < 0.01). Together, CSA and muscle activation accounted for 61.5% of the variance in torque ( p < 0.01). The greatest gains in muscle activation were made during the first 5 weeks of rehabilitation. Both increases in voluntary muscle activation and muscle hypertrophy contributed to the recovery in muscle strength following immobilization, with large gains in activation during the first 5 weeks of rehabilitation. In contrast, muscle CSA showed fairly comparable gains throughout both the early and later phase of rehabilitation. Published by Wiley Periodicals, Inc. J Orthop Res 24:1729–1736, 2006
Tissue response to polyglycolide, polydioxanone, polylevolactide, and metallic pins in cancellous bone: An experimental study on rabbits
Authors: Pihlajamäki Harri , Salminen Sari , Laitinen Outi , Tynninen Olli , Böstman Ole
Published: June 2006

The purpose of this study was to investigate, qualitatively and histoquantitatively, the tissue response of rabbit femur cancellous bone to polyglycolide (PGA), polydioxanone (PDS), polylevolactide (PLLA), and stainless steel pins under identical conditions. Eighty knees in 50 rabbits were operated on by inserting bioabsorbable pins (PGA, PDS, or PLLA) together with metallic Kirschner wire in 60, and two metallic Kirschner wires alone in 20 knees, while 20 knees served as intact controls. Follow‐up times were 3, 6, 12, 24, and 52 weeks. Cancellous bone tissue response to implants was studied using histological, histomorphometrical, microradiographical, and oxytetracycline fluorescence methods. Residual fragments of PGA and PDS were seen at 24 weeks. Complete degradation of these polymers had taken place before 52 weeks. No signs of degradation of the PLLA pins were observed within the entire follow‐up period. The osteoid formation surfaces at tissue implant‐interface were statistically larger in all test groups as compared to intact controls. The number of macrophages at tissue implant‐interfaces increased in all bioabsorbable implant specimens until 6 weeks, and with PGA until 12 weeks. No differences in the osseous response emerged when comparing groups of bioabsorbable implants with each other or with stainless steel group. Bioabsorbable pins and metallic Kirschner wires evoked an osteoconductive response in the cancellous bone surrounding implant, but the response intensity between implants displayed no differences. This suggests a simple, nonspecific walling‐off new‐bone front type of response. Consequently, the polymers possessed no specific osteostimulatory or osteoinhibitory properties. Within the follow‐up, no significant differences in biocompatibility between the implants appeared, and no frank inflammatory foreign‐body reactions occurred. The small‐volume pins obviously did not exceed the local tissue tolerance and clearing capacity of the bone. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1597–1606, 2006
Distribution of Kv1‐like potassium channels in the electromotor and electrosensory systems of the weakly electric fish Apteronotus leptorhynchus
Authors: Smith G. Troy , Unguez Graciela A. , Weber Christopher M.
Published: June 2006

The electromotor and electrosensory systems of the weakly electric fish Apteronotus leptorhynchus are model systems for studying mechanisms of high‐frequency motor pattern generation and sensory processing. Voltage‐dependent ionic currents, including low‐threshold potassium currents, influence excitability of neurons in these circuits and thereby regulate motor output and sensory filtering. Although Kv1‐like potassium channels are likely to carry low‐threshold potassium currents in electromotor and electrosensory neurons, the distribution of Kv1 α subunits in A. leptorhynchus is unknown. In this study, we used immunohistochemistry with six different antibodies raised against specific mammalian Kv1 α subunits (Kv1.1–Kv1.6) to characterize the distribution of Kv1‐like channels in electromotor and electrosensory structures. Each Kv1 antibody labeled a distinct subset of neurons, fibers, and/or dendrites in electromotor and electrosensory nuclei. Kv1‐like immunoreactivity in the electrosensory lateral line lobe (ELL) and pacemaker nucleus are particularly relevant in light of previous studies suggesting that potassium currents carried by Kv1 channels regulate neuronal excitability in these regions. Immunoreactivity of pyramidal cells in the ELL with several Kv1 antibodies is consistent with Kv1 channels carrying low‐threshold outward currents that regulate spike waveform in these cells (Fernandez et al., J Neurosci 2005;25:363–371). Similarly, Kv1‐like immunoreactivity in the pacemaker nucleus is consistent with a role of Kv1 channels in spontaneous high‐frequency firing in pacemaker neurons. Robust Kv1‐like immunoreactivity in several other structures, including the dorsal torus semicircularis, tuberous electroreceptors, and the electric organ, indicates that Kv1 channels are broadly expressed and are likely to contribute significantly to generating the electric organ discharge and processing electrosensory inputs. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Assessing functional mobility in survivors of lower‐extremity sarcoma: Reliability and validity of a new assessment tool
Authors: Marchese Victoria G. , Rai Shesh N. , Carlson Claire A. , Hinds Pamela S. , Spearing Elena M. , Zhang Lijun , Callaway Lulie , Neel Michael D. , Rao Bhaskar N. , Ginsberg Jill P.
Published: June 2006

Background

Reliability and validity of a new tool, Functional Mobility Assessment (FMA), were examined in patients with lower‐extremity sarcoma. FMA requires the patients to physically perform the functional mobility measures, unlike patient self‐report or clinician administered measures.

Procedure

A sample of 114 subjects participated, 20 healthy volunteers and 94 patients with lower‐extremity sarcoma after amputation, limb‐sparing, or rotationplasty surgery. Reliability of the FMA was examined by three raters testing 20 healthy volunteers and 23 subjects with lower‐extremity sarcoma. Concurrent validity was examined using data from 94 subjects with lower‐extremity sarcoma who completed the FMA, Musculoskeletal Tumor Society (MSTS), Short‐Form 36 (SF‐36v2), and Toronto Extremity Salvage Scale (TESS) scores. Construct validity was measured by the ability of the FMA to discriminate between subjects with and without functional mobility deficits.

Results

FMA demonstrated excellent reliability (ICC [2,1] ≥0.97). Moderate correlations were found between FMA and SF‐36v2 (r = 0.60, P < 0.01), FMA and MSTS (r = 0.68, P < 0.01), and FMA and TESS (r = 0.62, P < 0.01). The patients with lower‐extremity sarcoma scored lower on the FMA as compared to healthy controls (P < 0.01).

Conclusion

The FMA is a reliable and valid functional outcome measure for patients with lower‐extremity sarcoma. This study supports the ability of the FMA to discriminate between patients with varying functional abilities and supports the need to include measures of objective functional mobility in examination of patients with lower‐extremity sarcoma. Pediatr Blood Cancer 2007;49:183–189. © 2006 Wiley‐Liss, Inc.
Macromolecular properties from light‐scattering experimental data using linear inverse problem theory
Authors: Virtuoso Luciano S. , Sebastião Rita C. O. , Braga João P. , Da Silva Luis H. M.
Published: June 2006

The inversion of the temporal correlation function in dynamic light‐scattering experimental data for polyethylene oxide + H2O + NaCl is treated in the present work. The relaxation time distribution function for this ill‐posed problem is obtained by a recurrent neural network, using analytical inverse Laplace transform as the initial condition. Diffusion coefficient and particle size distributions can also be retrieved from this relaxation time distribution, providing important information for the experimental researcher. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Rotor flux magnitude and angle control strategy for doubly fed induction generators
Authors: Anaya‐Lara Olimpo , Hughes F. Michael , Jenkins Nicholas , Strbac Goran
Published: June 2006

A new control strategy is investigated for Doubly Fed Induction Generators (DFIGs). It exercises control over the generator terminal voltage and output power by adjusting the magnitude and angle of the rotor flux vector. It is shown that this control strategy leads to low interaction between the power and voltage control loop, better system damping and voltage recovery following faults, and it also provides enhanced frequency regulation capability compared with that achieved with existing DFIG controllers described in the open literature. The dynamic performance of the proposed DFIG control is tested for small and large disturbances using a generic network that combines wind and conventional synchronous generation. Simulation results are presented and discussed that demonstrate the capabilities of the new strategy to enhance DFIG performance and its contribution to network operation.
Fluorescence Characteristics of Hydrophobic Partial Agonist Probes of the Cholecystokinin Receptor
Authors: Harikumar Kaleeckal G. , Pinon Delia I. , Miller Laurence J.
Published: June 2006

Fluorescence spectroscopic studies are powerful tools for the evaluation of receptor structure and the dynamic changes associated with receptor activation. Here, we have developed two chemically distinct fluorescent probes of the cholecystokinin (CCK) receptor by attaching acrylodan or a nitrobenzoxadiazole moiety to the amino terminus of a partial agonist CCK analogue. These two probes were able to bind to the CCK receptor specifically and with high affinity, and were able to elicit only submaximal intracellular calcium responses typical of partial agonists. The fluorescence characteristics of these probes were compared with those previously reported for structurally-related full agonist and antagonist probes. Like the previous probes, the partial agonist probes exhibited longer fluorescence lifetimes and increased anisotropy when bound to the receptor than when free in solution. The receptor-bound probes were not easily quenched by potassium iodide, suggesting that the fluorophores were protected from the extracellular aqueous milieu. The fluorescence characteristics of the partial agonist probes were quite similar to those of the analogous full agonist probes and quite distinct from the analogous antagonist probes. These data suggest that the partially activated conformational state of this receptor is more closely related to its fully active state than to its inactive state.
Infrequent use of antidepressants in depressed individuals (an interview and prescription database study in a defined Swedish population 2001–2002)
Authors: Henriksson S. , Asplund R. , Boëthius G. , Hällström T. , Isacsson G.
Published: June 2006

Purpose:

To investigate whether antidepressants are over-used, under-used, or misused, by determining to what extent the depressed individuals in a defined population are treated with antidepressant medication and, from the other end, to what extent prescribed antidepressants are aimed for the treatment of depression.

Subjects and method:

From an individual based prescription database in the County of Jämtland, 2048 individuals representative for the general population were selected. The presence of current depression in these individuals was screened by a mailed self-screening questionnaire. Individuals with depression according to the questionnaire were interviewed by a psychiatrist using a structured interview (SCAN) to confirm the diagnosis. Their use of antidepressants was obtained from the prescription database.

Results:

Sixty-two (4.5%) out of 1375 were diagnosed with depression and 17 (27%) of these were taking an antidepressant. In addition 44 individuals, currently not depressed, were taking antidepressants. Twenty-five of these were interviewed per telephone and it was found that the indications for 18 of them were continuation treatment of depression, and for seven of them pain, sleep disturbance or anxiety.

Conclusion:

Antidepressants appear to be under-used in the population. Only one in four of the depressed individuals was treated with antidepressant medication. Those who had antidepressant medication without being currently depressed had, with few exceptions, either continuation treatment for depression in remission or treatment on other approved indications.
Accelerated induction of apoptosis in insect cells by baculovirus‐expressed SARS‐CoV membrane protein
Authors: Lai Chia-Wei , Chan Zun-Ren , Yang Ding-Gang , Lo Wen-Hsin , Lai Yiu-Kay , Chang Margaret Dah-Tsyr , Hu Yu-Chen
Published: June 2006

It has been shown that severe acute respiratory syndrome‐associated coronavirus (SARS‐CoV) 3a and 7a proteins, but not membrane (M) protein, induce apoptosis in mammalian cells. Upon expression of SARS‐CoV M protein using the baculovirus/insect cell expression system, however, we found that the expressed M protein triggered accelerated apoptosis in insect cells, as characterized by rapid cell death, elevated cytotoxicity, cell shrinkage, nuclear condensation and DNA fragmentation. Conversely, the M protein expressed in mammalian cells did not induce apoptosis. This is the first report describing the induction of apoptosis by SARS‐CoV M protein in animal cells and possible implications are discussed.
Whole blood cytokine profiles in cats infected by feline coronavirus and healthy non-FCoV infected specific pathogen-free cats
Authors: Gelain Maria E , Meli Marina , Paltrinieri Saverio
Published: June 2006

In this study, the cytokine profiles of clinically healthy cats naturally infected with feline coronavirus (FCoV), of cats with feline infectious peritonitis (FIP) and of specific pathogen-free (SPF) cats were investigated in whole blood using a traditional reverse-transcriptase polymerase chain reaction (RT-PCR) assay and a semi-quantitative method of analysis based on computerised quantification of positive bands. The low inter-assay coefficient of variation recorded demonstrated that this method is highly repeatable. Compared with SPF cats, cytokine production was upregulated in most of the samples from FCoV-positive non-symptomatic cats. The appearance of a case of FIP in the cattery was associated with an increased expression of cytokines, in particular there was an increased production of IL-1β and IFN-γ, suggesting that these cytokines might protect infected cats from the disease. This hypothesis was also supported by the low levels of IFN-γ recorded in blood from cats with FIP.
The Effect of Endothelial Cell Growth Factor on Peripheral Nerve Regeneration
Authors: Smith Michael S. , Browne J. Dale
Published: June 2006

Neural regeneration after grafting can be unpredictable. In an effort to enhance the return of function after cable grafting, we studied the effects of an angiogenic factor, endothelial cell growth factor (ECGF), on regenerating nerves. Cable grafts on the sciatic nerve were established in 18 rats and treated with ECGF or a control saline solution. At 5 weeks, nerve conduction studies were performed, and the animals were killed for histologic measurements of graft vascularity and axon counts. A significant increase in vascularity was noted in the treated group versus the control group; neither the axon counts nor the nerve conduction velocities differed significantly between the two groups, although the treated group appeared to show improved neural conduction compared with the control group.
The Histologic Fate of Autologous Collagen Injected into the Canine Vocal Fold
Authors: Staskowski Paul A. , Ford Charles N. , Inagi Katsuhide
Published: June 2006

Collagen is a functionally essential component of the five‐layered structure of the vocal fold. Soluble bovine collagen has previously been shown to be an effective injectable bioimplant for vocal fold defects, paralysis, and, especially, scarred larynges. Although bovine collagen appears to be well tolerated, the concern for possible adverse immunologic responses has deterred approval from the Food and Drug Administration for its clinical use in the larynx. Currently we are investigating the use of injectable autologous collagen for vocal fold augmentation. The purpose of this study is to examine the histologic fate of autologous collagen injected into the canine vocal fold at multiple intervals after injection. An ellipse of skin measuring 3 × 6cm was harvested from each of three dogs and processed into a naturally cross‐linked injectable solution of collagen (Autologen). This autologous collagen was injected into one vocal fold and a control injection of buffer solution was injected contralaterally. The injections were well tolerated and no dog appeared to suffer any immediate or delayed ill effects. The dog larynges were harvested 1, 3, and 6 months after collagen injection and examined grossly and histologically. Injected autologous collagen material persisted in these experimental animals and appeared to be well tolerated. Based on this preliminary study, we anticipate autologous collagen to be at least as suitable as bovine chemically cross‐linked collagen as an injectable bioimplant for vocal fold augmentation. It may also have the advantage of added safety and stability.