bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal and mechanical properties of polyurethane rigid foam/modified nanosilica composite
Authors: Nikje Mir Mohammad Alavi , Tehrani Zahra Mazaheri 
Published: September 2009

AbstractSurface modification of fumed nanosilica was performed by using n‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilane as a coupling agent. Then, modified nanosilica was utilized in the preparation of polyurethane rigid foam. The characterization and the study of properties were done by some techniques, such as Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, dynamic mechanical analysis, and thermomechanical analysis. Also, tensile test was examined to evaluate the static mechanical properties. With the increasing of modified nanosilica, thermal and static mechanical properties were enhanced, but dynamic mechanical behavior was different from static mechanical behavior because of the different properties of interfacial domain and bulk matrix. The presence of functional groups on the nanosilica surface affected stoichiometry and reduced hard phase formation in bulk polymer. The decrease in glass transition temperature (Tg) confirmed this statement. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Validation of the Comprehensive ICF Core Set for obstructive pulmonary diseases from the perspective of physiotherapists
Authors: Rauch Alexandra , Kirchberger Inge , Stucki Gerold , Cieza Alarcos 
Published: September 2009

AbstractBackground and Purpose. The ‘Comprehensive ICF Core Set for obstructive pulmonary diseases’ (OPD) is an application of the International Classification of Functioning, Disability and Health (ICF) and represents the typical spectrum of problems in functioning of patients with OPD. To optimize a multidisciplinary and patient‐oriented approach in pulmonary rehabilitation, in which physiotherapy plays an important role, the ICF offers a standardized language and understanding of functioning. For it to be a useful tool for physiotherapists in rehabilitation of patients with OPD, the objective of this study was to validate this Comprehensive ICF Core Set for OPD from the perspective of physiotherapists. Method. A three‐round survey based on the Delphi technique of physiotherapists who are experienced in the treatment of OPD asked about the problems, resources and aspects of environment of patients with OPD that physiotherapists treat in clinical practice (physiotherapy intervention categories). Responses were linked to the ICF and compared with the existing Comprehensive ICF Core Set for OPD. Results. Fifty‐one physiotherapists from 18 countries named 904 single terms that were linked to 124 ICF categories, 9 personal factors and 16 ‘not classified’ concepts. The identified ICF categories were mainly third‐level categories compared with mainly second‐level categories of the Comprehensive ICF Core Set for OPD. Seventy of the ICF categories, all personal factors and 15 ‘not classified’ concepts gained more than 75% agreement among the physiotherapists. Of these ICF categories, 55 (78.5%) were covered by the Comprehensive ICF Core Set for OPD. Conclusion. The validity of the Comprehensive ICF Core Set for OPD was largely supported by the physiotherapists. Nevertheless, ICF categories that were not covered, personal factors and not classified terms offer opportunities towards the final ICF Core Set for OPD and further research to strengthen physiotherapists' perspective in pulmonary rehabilitation. Copyright © 2009 John Wiley & Sons, Ltd.
A novel approach to segregate and identify functional loop regions in protein structures using their Ramachandran maps
Authors: Kumar Mattaparthi Venkata Satish , Swaminathan Rajaram 
Published: September 2009

AbstractThe loops which connect or flank helices/sheets in protein structures are known to be functionally important. However, ironically they also belong to the part of protein whose structure is least accurately predicted. Here, a new method to isolate and analyze loop regions in protein structure is proposed using the spatial coordinates of the solved three‐dimensional structure. The extent of dispersion among points of successive amino acid residues in the Ramachandran map of protein region is utilized to calculate the Mean Separation between these points in the Ramachandran Plot (MSRP). Based on analysis of 2935 protein secondary structure regions obtained using DSSP software, spanning a range from 2 to 64 residues, taken from a set of 170 proteins, it is shown that helices (MSRP < 17) and strands (MSRP < 64) stand effectively demarcated from the loop regions (MSRP > 130). Analysis of 43 DNA binding and 98 ligand binding proteins revealed several loop regions with clear change in MSRP subsequent to binding. The population of such loops correlated with the magnitude of backbone displacement in the protein subsequent to binding. Can changes in MSRP quantify the temporal oscillations in dihedral angles among structured/unstructured regions in proteins? Molecular dynamics simulations (10 ns) revealed that deviations in MSRP among different snapshots in the trajectory were at least twofold higher for unstructured proteins in comparison with ordered proteins. The above results validate the use of MSRP parameter as a tool to identify and investigate functionally active loops and unstructured regions in protein structures. Proteins 2010. © 2009 Wiley‐Liss, Inc.
Evidence of field‐evolved resistance to Cry1Ac‐expressing Bt cotton in Helicoverpa armigera (Lepidoptera: Noctuidae) in northern China
Authors: Liu Fengyi , Xu Zhiping , Zhu Yu Cheng , Huang Fangneng , Wang Yanhua , Li Huiling , Li Hua , Gao Congfen , Zhou Weijun , Shen Jinliang 
Published: September 2009

AbstractBACKGROUND: Evolution of resistance threatens the continued success of transgenic crops expressing insecticidal proteins. One of the key factors for successful resistance management is the timely implementation of monitoring programmes to detect early changes of resistance allele frequency in field populations. F1/F2 screen, dose–response bioassays and field survey were used to monitor resistance to the Cry1Ac‐expressing cotton in a field population of Helicoverpa armigera (Hübner), the primary target of transgenic Bt cotton in China.RESULTS: Field survey showed an increased trend of egg populations of H. armigera on Bt cotton in the Qiuxian area from 2003 to 2007. By using the F2 screening procedure, the resistance allele frequency in the Qiuxian (Hebei, China) population of H. armigera collected during 2007 was estimated to be 0.075 (95% CI: 0.053–0.100), which was 12 times greater than that estimated 9 years ago. Dose–response bioassay with the field population collected from the same area showed a significant resistance level (11‐fold) to Cry1Ac toxin compared to a laboratory susceptible strain.CONCLUSION: This study documented a case of field‐evolved resistance in H. armigera after several years of intensive planting of Bt cotton. Proactive tactics must be adopted to prevent further increase of resistance gene frequency in the Qiuxian region. Copyright © 2009 Society of Chemical Industry
Monolithic self‐sustaining nanographene sheet grown using plasma‐enhanced chemical vapor deposition
Authors: Takeuchi Wakana , Takeda Keigo , Hiramatsu Mineo , Tokuda Yutaka , Kano Hiroyuki , Kimura Shigeru , Sakata Osami , Tajiri Hiroo , Hori Masaru 
Published: September 2009

AbstractWe have fabricated carbon nanowalls (CNWs) composed of monolithic self‐sustaining nanographene sheets standing vertically on a Si substrate, using plasma‐enhanced chemical vapor deposition with a C2F6/H2 mixture. The crystallinity, evaluated by Raman spectroscopy and synchrotron X‐ray surface diffraction, and the electrical properties of the CNWs were improved by introducing O2 gas into the source gas mixture during the CNW growth process. The temperature dependence of the resistivity of the CNW films exhibited semiconductor behavior.
Determination of cylindrospermopsin in freshwaters and fish tissue by liquid chromatography coupled to electrospray ion trap mass spectrometry
Authors: Gallo Pasquale , Fabbrocino Serena , Cerulo Maria Grazia , Ferranti Pasquale , Bruno Milena , Serpe Luigi 
Published: September 2009

AbstractCylindrospermopsin (CYN) is a toxic alkaloid‐like compound produced by some strains of cyanobacteria, procariotic organisms occurring in water blooms, observed worldwide in eutrophic lakes and drinking water reservoirs. Methods for determination of CYN in freshwater and fish muscle by liquid chromatography coupled to electrospray ion trap mass spectrometry are herein described. The performances of both methods are reported; ion trap LC/ESI‐MS/MS resulted highly selective and reliable in unambiguous identification of CYN, based on monitoring the precursor ion and three product ions. The methods developed showed satisfactory mean recoveries (higher than 63.6%) and relative standard deviations, ranging from 5.8 to 9.8%. The limits of quantification at 0.10 ng/mL in freshwaters and 1.0 ng/g in fish muscle, respectively, allow for determination of CYN also in early contamination stages. Ion trap LC/ESI‐MS/MS was successfully applied to the identification and quantification of CYN in water and cyanobacteria extracts from Lake Averno, near Naples, representing the first case of contamination described in southern Italy. Copyright © 2009 John Wiley & Sons, Ltd.
Determination of rare earth elements in tomato plants by inductively coupled plasma mass spectrometry techniques
Authors: Spalla S. , Baffi C. , Barbante C. , Turretta C. , Cozzi G. , Beone G. M. , Bettinelli M. 
Published: September 2009

AbstractIn recent years identification of the geographical origin of food has grown more important as consumers have become interested in knowing the provenance of the food that they purchase and eat. Certification schemes and labels have thus been developed to protect consumers and genuine producers from the improper use of popular brand names or renowned geographical origins. As the tomato is one of the major components of what is considered to be the healthy Mediterranean diet, it is important to be able to determine the geographical origin of tomatoes and tomato‐based products such as tomato sauce. The aim of this work is to develop an analytical method to determine rare earth elements (RRE) for the control of the geographic origin of tomatoes. The content of REE in tomato plant samples collected from an agricultural area in Piacenza, Italy, was determined, using four different digestion procedures with and without HF. Microwave dissolution with HNO3 + H2O2 proved to be the most suitable digestion procedure. Inductively coupled plasma quadrupole mass spectrometry (ICPQMS) and inductively coupled plasma sector field plasma mass spectrometry (ICPSFMS) instruments, both coupled with a desolvation system, were used to determine the REE in tomato plants in two different laboratories. A matched calibration curve method was used for the quantification of the analytes. The detection limits (MDLs) of the method ranged from 0.03 ng g−1 for Ho, Tm, and Lu to 2 ng g−1 for La and Ce. The precision, in terms of relative standard deviation on six replicates, was good, with values ranging, on average, from 6.0% for LREE (light rare earth elements) to 16.5% for HREE (heavy rare earth elements). These detection limits allowed the determination of the very low concentrations of REE present in tomato berries. For the concentrations of REE in tomato plants, the following trend was observed: roots > leaves > stems > berries. Copyright © 2009 John Wiley & Sons, Ltd.
Extending matrix‐assisted laser desorption/ionization triple quadrupole mass spectrometry enzyme screening assays to targets with small molecule substrates
Authors: Rathore Rakesh , Corr Jay J. , Lebre Daniel T. , Seibel William L. , Greis Kenneth D. 
Published: September 2009

AbstractMass spectrometry (MS)‐based high‐throughput screening (HTS) has tremendous potential as an alternative to current screening methods due to its speed, sensitivity, reproducibility and label‐free readout. We recently reported that a new generation matrix‐assisted laser desorption/ionization triple quadrupole (MALDI‐QqQ) mass spectrometer is ideally suited for a variety of enzyme assays and screening protocols. However, all the targets measured to date had peptide substrates that were easily monitored by selected ion monitoring (SIM) without interference from the MALDI matrix. To further extend the application to enzymes with small molecule, non‐peptide substrates, we evaluated this method for measuring enzyme activity and inhibition of acetylcholinesterase (AChE). Due to the potential of MALDI matrix interference, multiple reaction monitoring (MRM) was investigated for selective MS/MS transitions and to accurately measure the conversion of acetylcholine into choline. Importantly, ionization, detection and MRM transition efficiency differences between the substrate and product can be overcome by pre‐balancing the MRM transitions during method development, thus allowing for a direct readout of the enzyme activity using the ratio of the substrate and product signals. Further validation of the assay showed accurate concentration‐dependent inhibition measurements of AChE with several known inhibitors. Finally, a small library of 1008 drug‐like compounds was screened at a single dose (10 µM) and the top 10 inhibitors from this primary screen were validated in a secondary screen to determine the rank order of inhibitory potency for each compound. Collectively, these data demonstrate that a MALDI‐QqQMS‐based readout platform is amenable to measuring small molecule substrates and products and offers significant advantages over current HTS methods in terms of speed, sensitivity, reproducibility and reagent costs. Copyright © 2009 John Wiley & Sons, Ltd.
Molecular depth profiling of multilayer structures of organic semiconductor materials by secondary ion mass spectrometry with large argon cluster ion beams
Authors: Ninomiya Satoshi , Ichiki Kazuya , Yamada Hideaki , Nakata Yoshihiko , Seki Toshio , Aoki Takaaki , Matsuo Jiro 
Published: September 2009

AbstractIn this study, we present molecular depth profiling of multilayer structures composed of organic semiconductor materials such as tris(8‐hydroxyquinoline)aluminum (Alq3) and 4,4′‐bis[N‐(1‐naphthyl)‐N‐phenylamino]biphenyl (NPD). Molecular ions produced from Alq3 and NPD were measured by linear‐type time‐of‐flight (TOF) mass spectrometry under 5.5 keV Ar700 ion bombardment. The organic multilayer films were analyzed and etched with large Ar cluster ion beams, and the interfaces between the organic layers were clearly distinguished. The effect of temperature on the diffusion of these materials was also investigated by the depth profiling analysis with Ar cluster ion beams. The thermal diffusion behavior was found to depend on the specific materials, and the diffusion of Alq3 molecules was observed to start at a lower temperature than that of NPD molecules. These results prove the great potential of large gas cluster ion beams for molecular depth profiling of organic multilayer samples. Copyright © 2009 John Wiley & Sons, Ltd.
Atmospheric pressure thermospray ionization using a heated microchip nebulizer
Authors: Keski‐Rahkonen Pekka , Haapala Markus , Saarela Ville , Franssila Sami , Kotiaho Tapio , Kostiainen Risto , Auriola Seppo 
Published: September 2009

AbstractWhen a standard atmospheric pressure chemical ionization (APCI) or atmospheric pressure photoionization (APPI) ion source is used without applying the corona discharge or photoirradiation, atmospheric pressure thermospray ionization (APTSI) of various compounds can be achieved. Although largely ignored, this phenomenon has recently gained interest as an alternative ionization technique. In this study, this technique is performed for the first time on a miniaturized scale using a microchip nebulizer. Sample ionization with the presented microchip‐APTSI (µAPTSI) is achieved by applying only heat and gas flow to a nebulizer chip, without any other methods to promote gas‐phase ionization. To evaluate the performance of the described µAPTSI setup, ionization efficiency for a set of test compounds was monitored as the microchip positioning, temperature, nebulizer gas flow rate, sample solution composition, and solvent flow rate were varied. The µAPTSI mass spectra of the test compounds were also compared to those obtained with ESI and APCI. The µAPTSI produces ESI‐like spectra with low background noise, favoring the formation of protonated or deprotonated molecules of compounds that are ionizable in solution. Multiple charging of peptides without in‐source fragmentation was also observed. Unlike ESI, however, the µAPTSI source can tolerate the presence of mobile phase additives like trifluoroacetic acid (TFA) without significant ion suppression. The µAPTSI source can be used with standard mass spectrometer ion source hardware, being a unique alternative to the present interfacing techniques. Copyright © 2009 John Wiley & Sons, Ltd.
Functionalized pyrolytic highly oriented graphite polymer film for surface‐assisted laser desorption/ionization mass spectrometry in environmental analysis
Authors: Kawasaki Hideya , Takahashi Naoyuki , Fujimori Hiroki , Okumura Kouji , Watanabe Takehiro , Matsumura Chisato , Takemine Syusuke , Nakano Takeshi , Arakawa Ryuichi 
Published: September 2009

AbstractThe pyrolytic highly oriented graphite polymer film (PGS) was first employed to analyze low‐mass analytes in environmental analysis by surface‐assisted laser desorption/ionization mass spectrometry (SALDI‐MS). PGS is a synthetic uniform and highly oriented graphite polymer film with high thermal anisotropic conductivity. We have found that negative ion mode SALDI‐MS using oxidized PGS (PGS‐SALDI‐MS) can be used to detect [M–H]− ions from perfluorooctanoic acid (PFOA) and other perfluoroalkylcarboxylic acids when the PGS surface is modified with the cationic polymer polyethyleneimine (PEI). The signal intensity of PFOA when employing the PEI modification showed a ten‐fold increase over that obtained from desorption/ionization on porous silicon (DIOS). PFOA was quantified using PGS‐SALDI‐MS and the calibration curve showed a wide linear dynamic range of response (20–1000 ppb). The combination of atmospheric pressure ionization and PGS (AP‐PGS‐SALDI) showed greater signal intensity than vacuum PGS‐SALDI for deprotonated PFOA. Several other environmentally important chemicals, including perfluoroalkylsulfonic acid, pentachlorophenol, bisphenol A, 4‐hydroxy‐2‐chlorobiphenyl, and benzo[a]pyrene, were also successfully used to evaluate PGS‐SALDI‐MS. In addition, we found that nonafluoro‐1‐butanesulfonic acid was able to produce protonated peptides in positive ion PGS‐SALDI‐MS, but that perfluoropentanoic acid and trifluoroacetic acid were not. It is suggested that perfluoroalkylsulfonic acids are better protonating agents than perfluoroalkylcarboxylic acids in SALDI‐MS. Copyright © 2009 John Wiley & Sons, Ltd.
Advantages of compound‐specific stable isotope measurements over bulk measurements in studies on plant uptake of intact amino acids
Authors: Sauheitl Leopold , Glaser Bruno , Weigelt Alexandra 
Published: September 2009

AbstractIncreasing interest in the ability of plants to take up amino acids has given rise to questions on the accuracy of the commonly used bulk method to measure and calculate amino acid uptake. This method uses bulk measurements of 13C and 15N enrichment in plant tissues after application of dual‐labelled amino acids but some authors have recommended the use of compound‐specific stable isotope (CSI) analysis of the plants' amino acids instead. However, there has never been a direct evaluation of both methods. We conducted a field study applying dual‐labelled (13C, 15N) amino acids (glycine, valine, tyrosine and lysine) to soil of a Plantago lanceolata monoculture. Root and shoot samples were collected 24 h after label application and the isotope composition of the plant tissues was investigated using bulk and CSI measurements. Enrichment of 13C in the case of CSI measurements was limited to the applied amino acids, showing that no additional 13C had been incorporated into the plants' amino acid pool via the uptake of tracer‐derived C‐fragments. Compared with this rather conservative indicator of amino acid uptake, the 13C enrichment of bulk measurements was 8, 5, 1.6 and 6 times higher for fine roots, storage roots, shoot and the whole plant, respectively. These findings show that the additional uptake of tracer‐derived C‐fragments will result in a considerable overestimation of amino acid uptake in the case of bulk measurements. We therefore highly recommend the use of CSI measurements for future amino acid uptake studies due to their higher accuracy. Copyright © 2009 John Wiley & Sons, Ltd.
Development of a new electron ionization/field ionization ion source for gas chromatography/time‐of‐flight mass spectrometry
Authors: Miyamoto Kenji , Fujimaki Susumu , Ueda Yoshihisa 
Published: September 2009

AbstractWe have developed a combined EI/FI source for gas chromatography/orthogonal acceleration time‐of‐flight mass spectrometry (GC/oaTOFMS). In general, EI (electron ionization) and FI (field ionization) mass spectra are complementary: the EI mass spectrum contains information about fragment ions, while the FI mass spectrum contains information about molecular ions. Thus, the comparative study of EI and FI mass spectra is useful for GC/MS analyses. Unlike the conventional ion sources for FI and EI measurements, the newly developed source can be used for both measurements without breaking the ion source vacuum or changing the ion source. Therefore, the combined EI/FI source is more preferable than the conventional EI or FI ion source from the viewpoint of the reliability of measurements and facility of operation.Using the combined EI/FI source, the complementarity between EI and FI mass spectra is demonstrated experimentally with n‐hexadecane (100 pg): characteristic fragment ions for the n‐alkane such as m/z 43, 57, 71, and 85 are obtained in the EI mass spectrum, while only the parent peak of m/z 226 (M+) without any fragment ions is observed in the FI mass spectrum. Moreover, the field desorption (FD) measurement is also demonstrated with poly(ethylene glycol)s M600 (10 ng) and M1000 (15 ng). Signals of [M+H]+, [M+Na]+ and [M+K]+ are clearly detected in the FD mass spectra. Copyright © 2009 John Wiley & Sons, Ltd.
Perceptions and determinants of environmental concern: the case of Hong Kong and its implications for sustainable development
Authors: Wong Timothy Ka‐ying , Wan Po‐san 
Published: September 2009

AbstractEnvironmental concern is a precursor to behavioural change. This article draws upon data from two surveys conducted in 2000 and 2008 to examine the development of environmental concern in Hong Kong and its major determinants. It finds that Hong Kong people have consistently shown a high level of environmental concern in terms of both their perception of the seriousness of environmental problems and their assessment of how these problems will develop in the future. In line with previous findings, our study confirms that environmental concern is affected by a combination of positional, individual and institutional factors, including gender, education, pro‐environmental beliefs, especially concern for environmental damage, and the government's performance in environmental protection. Among these factors, government performance is shown to be of crucial importance. Implications for sustainable development are highlighted. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.