bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamics in the use of drugs
Authors: van Ours Jan C. 
Published: June 2006

AbstractThis paper uses information about prime age individuals living in Amsterdam to study the dynamics in the use of tobacco, cannabis, and cocaine. The analysis examines transitions from non‐use to use, as well as transitions from use to non‐use. Particular attention is given to the effect of the age of onset on quitting behavior. The empirical analysis shows that for most of the drugs investigated, the earlier individuals start using a particular drug the less likely they are to stop using that drug. Copyright © 2006 John Wiley & Sons, Ltd.
DFT calculations of 57Fe Mössbauer isomer shifts and quadrupole splittings for iron complexes in polar dielectric media: Applications to methane monooxygenase and ribonucleotide reductase
Authors: Han Wen‐Ge , Liu Tiqing , Lovell Timothy , Noodleman Louis 
Published: June 2006

AbstractTo predict the isomer shifts of Fe complexes in different oxidation and spin states more accurately, we have performed linear regression between the measured isomer shifts (δexp) and DFT (PW91 potential with all‐electron triple‐ζ plus polarization basis sets) calculated electron densities at Fe nuclei [ρ(0)] for the Fe2+,2.5+ and Fe2.5+,3+,3.5+,4+ complexes separately. The geometries and electronic structures of all complexes in the training sets are optimized within the conductor like screening (COSMO) solvation model. Based on the linear correlation equation δexp = α[ρ(0) − 11884.0] + C, the best fitting for 17 Fe2+,2.5+ complexes (totally 31 Fe sites) yields α = −0.405 ± 0.042 and C = 0.735 ± 0.047 mm s−1. The correlation coefficient is r = −0.876 with a standard deviation of SD = 0.075 mm s−1. In contrast, the linear fitting for 19 Fe2.5+,3+,3.5+,4+ complexes (totally 30 Fe sites) yields α = −0.393 ± 0.030 and C = 0.435 ± 0.014 mm s−1, with the correlation coefficient r = −0.929 and a standard deviation SD = 0.077 mm s−1. We provide a physical rationale for separating the Fe2+,2.5+ fit from the Fe2.5+,3+,3.5+,4+ fit, which also is clearly justified on a statistical empirical basis. Quadrupole splittings have also been calculated for these systems. The correlation between the calculated (ΔEQ(cal)) and experimental (ΔEQ(exp)) quadrupole splittings based on |ΔEQ(exp)| = A |ΔEQ(cal)| + B yields slope A, which is almost the ideal value 1.0 (A = 1.002 ± 0.030) and intercept B almost zero (B = 0.033 ± 0.068 mm s−1). Further calculations on the reduced diferrous and oxidized diferric active sites of class‐I ribonucleotide reductase (RNR) and the hydroxylase component of methane monooxygenase (MMOH), and on a mixed‐valent [(tpb)Fe3+(μ‐O)(μ‐CH3CO2)Fe4+(Me3[9]aneN3)]2+ (S = 3/2) complex and its corresponding diferric state have been performed. Calculated results are in very good agreement with the experimental data. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1292–1306, 2006
DFT models for copper(II) bispidine complexes: Structures, stabilities, isomerism, spin distribution, and spectroscopy
Authors: Atanasov Mihail , Comba Peter , Martin Bodo , Müller Vera , Rajaraman Gopalan , Rohwer Heidi , Wunderlich Steffen 
Published: June 2006

AbstractVarious DFT and ab initio methods, including B3LYP, HF, SORCI, and LF‐density functional theory (DFT), are used to compute the structures, relative stabilities, spin density distributions, and spectroscopic properties (electronic and EPR) of the two possible isomers of the copper(II) complexes with derivatives of a rigid tetradentate bispidine ligand with two pyridine and two tertiary amine donors, and a chloride ion. The description of the bonding (covalency of the copper–ligand interactions) and the distribution of the unpaired electron strongly depend on the DFT functional used, specifically on the nonlocal DF correlation and the HF exchange. Various methods may be used to optimize the DFT method. Unfortunately, it appears that there is no general method for the accurate computation of copper(II) complexes, and the choice of method depends on the type of ligands and the structural type of the chromophore. Also, it appears that the choice of method strongly depends on the problem to be solved. LF‐DFT and spectroscopically oriented CI methods (SORCI), provided a large enough reference space is chosen, yield accurate spectroscopic parameters; EDA may lead to a good understanding of relative stabilities; accurate spin density distributions are obtained by modification of the nuclear charge on copper; solvation models are needed for the accurate prediction of isomer distributions. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1263–1277, 2006
Exploring the cell's network with molecular imaging
Authors: Enzmann Dieter R. 
Published: June 2006

AbstractMolecular imaging is already a powerful tool for investigating molecular interactions within the cell. Interpreting molecular imaging findings will, however, take us into the more unfamiliar, nonlinear realm of networks. The network class of interest is the “scale‐free” network, which characterizes not only the cell, but also surprisingly, other real work networks such as the world wide web. This network topology yields insights in how the cell is functionally organized via motifs, modules, and different types of hubs. Additional organizational information is gained from the cell's evolutionary history. Interpretation of molecular images will be deepened by a both qualitative and quantitative knowledge of the cell's network. Importantly, cell network behavior can be independent of molecular detail. For this reason, the same molecule can serve different functions in different cells or even within the same cell. Since a scale‐free network's behavior is likely to be nonlinear and exhibit emergent behavior, a degree of caution is prudent in assigning cause and effect to molecular imaging findings in our effort to reengineer some of the cell's functions. Molecular imagers will need to be cognizant of the level of organization in the cell's network they are interrogating. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Bone metastases from head and neck paragangliomas: Uncommon MR findings in an uncommon condition—Report of three cases
Authors: Duet Michèle , Herman Philippe , Wassef Michel , Huy Patrice Tran Ba , Laredo Jean‐Denis 
Published: June 2006

AbstractMalignancy (defined as metastatic disease) has been reported in nearly 5% of head and neck paragangliomas. Metastases preferentially target the lymph nodes, lung, liver, or bone. We describe three patients with multiple silent bone metastases exhibiting a fatty halo at MRI that coexisted with expansive bone lesions. In all cases, 123I‐metaiodobenzylguanidine (123MIBG) scintigraphy showed no abnormal tracer uptake, whereas 111In‐pentetreotide scintigraphy visualized a few silent bone metastases. These findings indicate that MRI should be included in the staging of paraganglioma patients with risk factors for malignancy. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Comparison of schwann cell and sciatic nerve transcriptomes indicates that mouse is a valid model for the human peripheral nervous system
Authors: Ten Asbroek Anneloor L.M.A. , Van Ruissen Fred , Ruijter Jan M. , Baas Frank 
Published: June 2006

AbstractHigh‐throughput gene expression analyses of murine models of the peripheral nervous system (PNS), and its cellular components, have yielded enormous amounts of expression data of the PNS in various conditions. These data provided clues for future research directions to further decipher this complex organ in relation to acquired and inherited PNS diseases. Various studies addressing the validity of mouse models for human conditions in other tissues and cell types have indicated that in many cases the mouse model only poorly represents the human situation. To determine how well the mouse can serve as model to study the biological processes occurring in the PNS, we compared the gene expression profiles that we generated for mouse and human sciatic nerve and cultured Schwann cells derived thereof. A two‐way analysis based on the differentially expressed genes between the sciatic nerve and the cultured Schwann cell, and which takes into account the differential expression between mouse and man, indicates that the human PNS is well represented by that of the mouse in terms of the “biological processes” ontology. © 2006 Wiley‐Liss, Inc.
Synthesis of Polyanilines Bearing Optically Active Substituents
Authors: Goto Hiromasa 
Published: June 2006

AbstractSummary: Optically active polyanilines were prepared by an interfacial polymerization with (NH4)2S2O8 in a water/perchloric acid/chloroform system. The pristine polymer obtained in this way is in the oxidized (doped) form. The polymers display the mirror‐image Cotton effect. The doping process in solution allows a change in the circular dichroism of the polymer. The procedure has great potential in the improved preparation of durable optoelectrical devices based on the good film‐forming properties of chiral polymers.CD spectra of R‐P2 (solid line) and S‐P2 (dashed line) in 4.0 × 10−4 M THF solution.magnified imageCD spectra of R‐P2 (solid line) and S‐P2 (dashed line) in 4.0 × 10−4 M THF solution.
Azoalkanes: A Novel Class of Flame Retardants
Authors: Nicolas Ronan C. , Wilén Carl‐Eric , Roth Michael , Pfaendner Rudolf , King Roswell E. 
Published: June 2006

AbstractSummary: The synthesis of azoalkanes such as azocyclohexane (1) and 4,4′‐bis(cyclohexylazocyclohexyl)methane (2) and their use as flame retardants in polymeric substrates is reported. For the first time it is demonstrated that azoalkanes alone can effectively provide flame retardancy and self‐extinguishing properties to poly(propylene) films at a very low concentration of 0.25 to 0.5 wt.‐%. All the poly(propylene) formulations passed DIN 4102‐1/B2 standards and the instant azoalkane‐containing poly(propylene) blends show no discoloration.4,4′‐bis(cyclohexylazocyclohexyl)methane.magnified image4,4′‐bis(cyclohexylazocyclohexyl)methane.
Homogeneously Dispersed Poly(propylene)/SiO2 Nanocomposites with Unprecedented Transparency
Authors: Asuka Kazuo , Liu Boping , Terano Minoru , Nitta Koh‐hei 
Published: June 2006

AbstractSummary: Physico‐chemical interactions between hydrophobic polyolefin materials and hydrophilic inorganic nanoparticles such as surface‐hydroxylated SiO2 have not been well understood so far. In this study, the effects of particle size and content of SiO2 nanoparticles on isothermal growth rate of PP spherulites in various PP/SiO2 nanocomposites were investigated by polarized optical microscopy. It was unexpected to find that hydrophilic SiO2 nanoparticles can be homogeneously dispersed in a PP matrix. Spherulite growth rates of PP in PP/SiO2 nanocomposites decrease significantly with increasing SiO2 content and decreasing particle size. Most interestingly, the spherulite growth rate was zero for PP/16 nm‐SiO2 nanocomposites with SiO2 content above 2.5 wt.‐% resulting in a highly transparent film.Photographs of 200 µm‐thick PP and PP/16 nm‐SiO2 (5 wt.‐%) sheets in front of a graphic pattern.magnified imagePhotographs of 200 µm‐thick PP and PP/16 nm‐SiO2 (5 wt.‐%) sheets in front of a graphic pattern.
Preparation and properties of chitosan/poly(vinyl alcohol) blend foams for copper adsorption
Authors: Wang Xiao , Chung Yong Sik , Lyoo Won Seok , Min Byung Gil 
Published: June 2006

AbstractA new form of polymer blend, macroporous chitosan/poly(vinyl alcohol) (PVA) foams made by a starch expansion process, exhibits the functionalities of chitosan while avoiding its poor mechanical properties and chemical instabilities. The appropriate conditions for foaming are discussed using both insoluble and water‐soluble chitosan. The chitosan/PVA foams demonstrated interconnected and open‐cell structures with large pore size from tens to hundreds of micrometers and high porosities from 73.6 to 84.3%. Glutaraldehyde was employed to improve the retention of chitosan and copper adsorption of the chitosan/PVA foams. While it increased the retention of chitosan and the adsorption capacities, glutaraldehyde decreased the pore size and porosity. The macroporous structure of the chitosan/PVA foams indicates extensive application prospects in terms of the considerable adsorption of heavy metal ions. Copyright © 2006 Society of Chemical Industry
Synthesis and properties of bismaleimide resin containing dicyclopentadiene or dipentene. VI
Authors: Hwang Hann‐Jang , Li Chun‐Hung , Wang Chun‐Shan 
Published: June 2006

AbstractNew aromatic bismaleimides (BMIs), bis(4‐maleimidophenoxy‐3,5‐dimethylphenyl)dicyclopentadiene (DCPDBMI) and bis(4‐maleimido‐phenoxy‐3,5‐dimethylphenyl)dipentene (DPBMI), containing a large dicyclopentadiene (DCPD) or dipentene (DP) and aryl ether linkage, were synthesized from diamine bis(4‐aminophenoxy‐3,5‐dimethylphenyl)dicyclopentadiene (DCPDA) or bis(4‐aminophenoxy‐3,5‐dimethylphenyl)dipentene(DPA) and maleic anhydride by the usual two‐step procedure that included ring‐opening addition to give bismaleamic acid, followed by cyclodehydration to bismaleimide. The monomers were characterized by Fourier transform infrared spectroscopy, proton NMR, elemental analyses, and mass spectra. Their thermal polymerization was investigated by DSC. The presence of a large cycloaliphatic moiety in the backbone of the bismaleimide increased the curing temperature and reduced the reactivity of the maleimide bond. Thermal and electrical properties of cured bismaleimide resins were studied using a dielectric analyzer, dynamic mechanical analyzer, and thermal gravimetric analyzer. These data were compared with that of commercial 4,4‐bismaleimidodiphenylmethane (DDMBMI). The cured DCPDBMI or DPBMI exhibits a lower dielectric constant, dissipation factor and moisture absorption than those of DDMBMI. Copyright © 2006 Society of Chemical Industry
Proteomic biomarkers for autoimmune disease
Authors: Hueber Wolfgang , Robinson William H. 
Published: June 2006

AbstractAutoimmune diseases affect 3% of the world population, yet the diagnosis and classification of autoimmune diseases remain based on clinical examination combined with traditional laboratory tests and imaging studies. The development of genomic and proteomic technologies provides an unprecedented ability to identify novel biosignatures to diagnose, classify, and guide therapeutic decision making in patients with autoimmune disease. In this article, we review recent advances in proteomics technologies and their application to autoimmune disease.
Old fold in a new X‐ray diffraction dataset? Low‐resolution molecular replacement using representative structural templates can provide phase information
Authors: Rajavel M. , Warrier Thulasi , Gopal B. 
Published: June 2006

AbstractThe advent of structural genomics has led to a dramatic increase in the number of structures deposited in the Protein Data Bank. The number of new folds, however, still remains a very small fraction of the total number of deposited structures. Recent data on the progress of the structural genomics initiative reveals that more than 85% of target proteins that progress to the stage of data collection and structure determination have a known fold. Enzymes, which tend to exploit reaction space while adopting a common stable scaffold, contribute significantly to this observation. Herein, we evaluate a method to examine the “old fold in a new dataset” scenario likely to be encountered in the structural genomics pipeline. We demonstrate that a fold detection strategy based on secondary structure signatures followed by molecular replacement using a minimalist model can be effectively used to solve the phase problem in X‐ray crystallography without further recourse to heavy atom derivatives or multiple anomalous dispersion techniques. Three common folds—the triosephosphate isomerase (TIM), adenine nucleotide alpha hydrolase‐like (HUP), and RNA recognition motif (RRM)—were examined using this approach. The results presented herein also provide an estimate of the extent of phase information that can be derived from a single domain in a large multidomain structure. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Molecular simulations reveal a new entry site in quercetin 2,3‐dioxygenase. A pathway for dioxygen?
Authors: Fiorucci Sébastien , Golebiowski Jérôme , Cabrol‐Bass Daniel , Antonczak Serge 
Published: June 2006

AbstractMolecular dynamics simulations performed on quercetin 2,3‐dioxygenase have shown the existence of a channel linking the bulk solvent and the cavity of the enzyme. Although much is known about the the oxygenolysis reaction catalyzed by this enzyme, the way dioxygen enters the active site has not been firmly established. The size, orientation and hydrophobic character of this channel suggests that it could provide an entrance for molecular dioxygen into the cavity. Free energy calculations show that such a process is likely to occur. Proteins 2006. © 2006 Wiley‐Liss, Inc.
STRUCTFAST: Protein sequence remote homology detection and alignment using novel dynamic programming and profile–profile scoring
Authors: Debe Derek A. , Danzer Joseph F. , Goddard William A. , Poleksic Aleksandar 
Published: June 2006

AbstractSTRUCTFAST is a novel profile—profile alignment algorithm capable of detecting weak similarities between protein sequences. The increased sensitivity and accuracy of the STRUCTFAST method are achieved through several unique features. First, the algorithm utilizes a novel dynamic programming engine capable of incorporating important information from a structural family directly into the alignment process. Second, the algorithm employs a rigorous analytical formula for profile–profile scoring to overcome the limitations of ad hoc scoring functions that require adjustable parameter training. Third, the algorithm employs Convergent Island Statistics (CIS) to compute the statistical significance of alignment scores independently for each pair of sequences. STRUCTFAST routinely produces alignments that meet or exceed the quality obtained by an expert human homology modeler, as evidenced by its performance in the latest CAFASP4 and CASP6 blind prediction benchmark experiments. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Variability of pesticide residues in crop units
Authors: Ámbrus Árpád 
Published: June 2006

AbstractThe results of 89 new field trials and 11 supervised trials were considered, together with 91 sets of residue data evaluated earlier. The datasets consisted of 22 643 valid residue data. As all variability factors calculated from individual sample sets are affected by the uncertainties of sampling and analysis, the average of the P0.975/Rave (97.5th percentile of the residue population divided by the average residues in the lot) values gives the best estimate for the variability factor. The Harrell–Davis (H–D) method gave an average value of 2.89 for the variability factor for all samples, while the average variability factors obtained from samples derived from the new field and supervised trials were 2.8 and 2.7 with the IUPAC and H–D methods respectively. The number of residue values below the LOQ in a sample set significantly affects the observed variability factors. It was found that datasets containing over 20% non‐quantifiable residues might not reflect the true variability of the residues. Mixing of treated and non‐treated commodities may significantly increase the apparent variability. Consequently, only datasets of known origin and consisting of well‐quantifiable residues should be used for estimation of the variability factor. Samples taken from marketed lots may not represent a single lot, and thus they have limited value in estimating the variability factor. The large number of residue data confirms the applicability of the default variability factor of 3 adopted by the FAO/WHO for deterministic estimation of the acute intake of pesticide residues. Copyright © 2006 Society of Chemical Industry
Leaf surface characteristics of apple seedlings, bean seedlings and kohlrabi plants and their impact on the retention and rainfastness of mancozeb
Authors: Hunsche Mauricio , Bringe Katja , Schmitz‐Eiberger Michaela , Noga Georg 
Published: June 2006

AbstractA study was made of the influence of the upper leaf surface characteristics on the retention and rainfastness of the contact fungicide mancozeb with and without tank‐mix adjuvants (RSO 5 and RSO 60) on apple seedlings, bean seedlings and kohlrabi plants. Large differences in roughness, in the amount and composition of surface waxes and in the retention and rainfastness of mancozeb were found among species. Strong correlations between roughness and total amount of surface waxes and mass of C29 alkane in the wax mass were also found. Fungicide retention was strongly, negatively correlated with surface roughness, total epicuticular wax, amount of C29 alkane and the total mass of alkanes. Rainfastness correlated strongly or very strongly with the amount of C28 alcohol and C33 alkane. The addition of a more hydrophobic (RSO 5) or a more hydrophilic (RSO 60) adjuvant to the spray solution influenced retention and rainfastness, and also altered the correlation coefficients. The present results support earlier observations which show that the success of adjuvants in enhancing the retention and rainfastness of agrochemicals depends on the characteristics of the leaf surface. Copyright © 2006 Society of Chemical Industry
A route comprehension support system for a robotic travel aid
Authors: Shi Yafang , Kotani Shinji , Mori Hideo 
Published: June 2006

AbstractWe have developed a robotic travel aid that can provide assistance to guide visually impaired people. According to the opinions of visually impaired people, for such travel aids to be safe and easy to use, the person being guided must be able to comprehend their route from the point of departure to their destination before starting off on their journey. Therefore, we have developed a route comprehension support system to be used as a subsystem in such a robotic travel aid. This system generates an explanation of the route that will be taken by the user on the basis of an XML file containing route information. In addition, we have designed an interface that takes into consideration the user's disabilities by using a combination of a touch keypad and speech synthesis. The system is able to make use of the fully functioning senses of the user to acquire information regarding the environment through which the user is passing, for instance, the user's sense of distance and information regarding how they control the robot, and generates route guidance instructions including information regarding footpaths, traffic controls, and the shape and size of intersections that can be confirmed by the user. We have verified the effectiveness of this guide system by means of experiments to evaluate the route understanding system with seven visually impaired subjects and experiments to evaluate the guidance performance of the system with four subjects; in both cases the system receiving positive evaluations. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(9): 87–99, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10568