bluuebunny/crossref_metadata_2025 huggingface dataset:
Two‐dimensional J‐resolved NMR spectroscopy: review of a key methodology in the metabolomics toolbox
Authors: Ludwig Christian , Viant Mark R.
Published: November 2009

One‐dimensional (1D) 1H NMR spectroscopy remains a leading analytical technology in metabolomics. Advantages of this approach include relatively rapid spectral acquisition and NMR resonances that provide a direct measure of metabolite concentration based upon a single internal standard. Severe spectral congestion can, however, significantly hinder both metabolite identification and quantification. Two‐dimensional 1H J‐resolved (JRES) NMR spectroscopy retains many of the benefits of 1D NMR, but additionally disperses the overlapping resonances into a second dimension, reducing congestion and increasing metabolite specificity. The usefulness of this approach to metabolomics was first realised six years ago, and since then it has been used in biological, medical and environmental studies of plants and animals. Here we provide a basic introduction to the 2D JRES NMR experiment and then discuss strategies for spectral acquisition and processing in the context of metabolomics applications, concluding with some key recommendations: acquisition using a double spin‐echo sequence with excitation sculpting; processing using the SEM window function, tilting and symmetricising, optionally followed by a skyline projection. Strategies for implementing JRES spectroscopy into the metabolomics toolbox are then considered, including its roles in metabolic fingerprinting, metabolite identification and metabolite quantification. Public resources and data standards for JRES metabolomics are reviewed. We conclude by evaluating the advantages (e.g. increased spectral dispersion and confidence in metabolite identification; fully automated processing; reduced batch‐to‐batch variation) and disadvantages (e.g. longer acquisition times; higher technical variability; phase‐twisted lineshapes resulting in quantification errors) of 2D JRES NMR vs the established 1D approach for metabolomics. Copyright © 2009 John Wiley & Sons, Ltd.
Properties of new cationic amphiphilic polymers in hydro‐alcoholic media
Authors: Bezzaoucha Fatiha , Lochon Pierre , Jonquières Anne , Aïnad‐Tabet Driss , Brembilla Alain , Fischer Arnaud
Published: November 2009

BACKGROUND: Following our recent synthesis and characterization of three new families of cationic amphiphilic polymers with great structural variability, this paper reports their physical chemical properties in aqueous media in relation to their chemical structure. These amphiphilic polymers are comb poly(meth)acrylamides laterally substituted by groups containing a quaternary ammonium site and hydrophobic n‐alkyl side chains with variable lengths.

RESULTS: Viscometry first showed that these polymers display typical polysoap behaviour in hydro‐alcoholic mixtures. Fluorescence spectrometry was then used to characterize the corresponding intramolecular association with two complementary fluorescent probes. In addition to confirming macromolecular folding, pyrene provided information about the probe local environment polarity whereas a molecular rotor gave interesting complementary information about the compactness of the corresponding nano‐domains.

CONCLUSION: It was shown that increasing the length of the n‐alkyl side chain induced much better polysoap properties whereas increasing the size of the spacer between the two polar amide and ammonium groups and the presence of a methyl side group had the greatest impact on the nano‐domain characteristics. Copyright © 2009 Society of Chemical Industry
The moderating role of borderline personality in the relationships between deliberate self‐harm and emotion‐related factors
Authors: Gratz Kim L. , Breetz Alisa , Tull Matthew T.
Published: November 2009

This study examined the associations between deliberate self‐harm (DSH) and key emotion‐related factors thought to underlie this behaviour (i.e. emotional dysregulation, avoidance and inexpressivity) among a non‐clinical sample of individuals with clinically‐relevant levels of borderline personality disorder (BPD) symptoms (high BPD) and those without significant BPD pathology (low BPD), and explored the moderating role of BPD status in these associations. Participants were 392 undergraduates who completed questionnaires assessing DSH, BPD symptoms, emotion dysregulation, experiential avoidance and emotional inexpressivity. Consistent with theories emphasizing the centrality of emotion dysregulation to DSH, overall emotion dysregulation and the particular dimension related to perceived difficulties modulating emotional arousal were associated with DSH status among both the high‐BPD and low‐BPD groups. However, other correlates of DSH differed as a function of BPD status, with emotional inexpressivity associated with DSH among the high‐BPD group and non‐judging of inner experience (negatively) associated with DSH among the low‐BPD group. Experiential avoidance was associated with DSH frequency among self‐harming individuals in the low‐BPD group. The results provide support for the role of emotion‐related factors (in particular, emotion dysregulation) in DSH among both high‐BPD and low‐BPD individuals, and highlight the need to control for BPD pathology when examining the correlates of DSH within non‐clinical samples. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of chain stiffness on the morphology of diblock copolymer melts
Authors: Tsige Mesfin , Leuty Gary , Bedard Joe
Published: November 2009

The authors have studied the microphase separation of symmetric diblock copolymers with variable block stiffness and different block chain lengths using coarse‐grained molecular dynamics simulations. The simulation results show that for symmetric diblock copolymers, a combination of chain length and relative stiffness between the blocks may play the major role in determining the equilibrium morphology of the system. When the variation in stiffness between blocks is small, the equilibrium morphology of the diblock system is found to be lamellar; this is also the case for systems with small chain lengths, regardless of the difference in block stiffness. However, in systems with longer chains with modest variation in stiffness between the blocks, an ordered cylindrical phase is formed in which the stiffer blocks form cylinders completely surrounded by the flexible components. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2556–2565, 2009
Temperature‐rise fractionation of poly(3‐alkyl thiophenes)
Authors: Lefevre Scott W. , Choi Heungyeal , Chang Taihyun , Ryu Chang Y.
Published: November 2009

In this article, we have investigated a temperature‐rise fractionation procedure for poly(3‐hexyl thophene) (P3HT) and poly(3‐octyl thophene) (P3OT) that provides well‐defined molecular weight (MW) fractions with improved molecular weight distributions (MWD) when compared with Soxhlet extraction. This process involves dispersing the material over C18‐boned silica stationary phase in a jacketed column and using incremental rises in column temperature (Tcol) to gradually improve solvent quality and selectively dissolve higher molecular weight samples with a narrow polydispersity (PDI). Fractionation of P3HT with ΔTcol = 5 °C in methylene chloride (MC) yielded 7 fractions ranging from Mp of 20 to 53 kg/mol with an average PDI of 1.80 compared with a mother sample of 3.10. Predominant recovery of P3HT was acquired for fractions with Tcol > 20 °C (30 wt %). Subsequent separation of P3OT in methylene chloride, with a reduced ΔTcol of 3 °C per fraction, due to increased solubility from the longer alkyl chain, generated 8 fractions with a weight range of Mn = 22 to 57 kg/mol with an mean PDI of 1.23 with the mother sample having PDI = 2.34, demonstrating the tunability of this method. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2547–2555, 2009
The stiffening of ultrathin polymer films in the rubbery regime: The relative contributions of membrane stress and surface tension
Authors: O'Connell Paul A. , McKenna Gregory B.
Published: November 2009

We have previously reported on a new nanobubble inflation technique we have developed to measure the absolute creep compliance of polymer films at thicknesses down to ∼10 nm (1–5). One of the more surprising results to come out of these studies was the observation that as the film thickness decreased the rubbery plateau compliance was seen to decrease dramatically. At the thinnest film thickness (∼10 nm) the compliance decreased (or conversely the stiffness increased) by some 3 orders of magnitude from the bulk value. It is known that, at the nanometer scale, surface tension effects can become significant. We examine here the contribution of surface tension to the observed stiffening and show that, while the contribution is important, it does not account for the degree of stiffening observed. This suggests that molecular or confinement induced stiffening is the major factor. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2441–2448, 2009
Mobility of single DNA chain under electric field during its transient contact with solid surfaces
Authors: Jing Benxin , Yang Qingbo , Zhu Yingxi , Zhao Jiang
Published: November 2009

The motion of DNA chain under electric field when it is in transient contact with the solid surfaces in aqueous solution was studied by single molecule fluorescence microscopy at the total internal reflection geometry (TIRFM). In situ observation discovered that single λ‐DNA chains driven by electric field made transient contact with the solid surface and made hitting–sliding–leaving‐like motion along the surface. By varying the surface chemistry, from the negative‐charged silanol group‐rich surface to positive‐charged amino group‐rich surface, as well as hydrophobic surfaces, the dependence of DNA mobility on the surface–DNA interaction was studied. The results show that a dependence of the mobility of DNA on the surface polarity with respect to DNA itself. The study on different surfaces rich of silanol, amide, amino, and methyl groups show a sequence of DNA mobility of silanol > amide > amino. The mobility of DNA on methyl terminated surface was found to be similar to that on amino surface. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2541–2546, 2009
Effect of fluorosurfactant on capillary instabilities in nanoimprinted polymer patterns
Authors: Alvine Kyle J. , Ding Yifu , Douglas Jack F. , Wook Ro Hyun , Okerberg Brian C. , Karim Alamgir , Lavery Kristopher A. , Lin‐Gibson Sheng , Soles Christopher L.
Published: November 2009

Surface forces play a paramount role in most aspects of Nanoimprint Lithography. In particular, subjecting nanoimprinted patterns to moderate heating allows surface tension to smooth out undesirable roughness and defects in the patterns, but this “thermal reflow” treatment can induce structural decay or even collapse of the patterns by capillary instability if this process is not carefully controlled. Adhesion between the mold and polymer film can also cause the imprinted structure to tear or fracture. Fluorinated surfactants (FS) are attractive for reducing mold adhesion, yet the effects of these additives on nanostructure stability during thermal reflow are not well understood. Here we present thermal stability studies of line‐space grating patterns created by Thermal Embossing Nanoimprint Lithography (TENIL) on model polystyrene (PS) films with FS additives. As expected by energy considerations, FS segregates to the air interface, where it seems to facilitate mold release. This also reduces the surface energy and thus reduces the driving force for pattern “slumping” (height decay). However, the beneficial effects of the surfactant are counterbalanced by the fact that the FS decreases the effective film viscosity, which accelerates nanopattern leveling. The net effect is that the pattern height decay is strongly a function of FS concentration. This enhanced film fluidity in the presence of FS also makes the pattern more susceptible to an undulatory capillary instability under thermal reflow conditions. Surface phase segregation of FS and PS is also observed in conjunction with both slumping and lateral capillary instabilities, which may be useful for producing chemically patterned surfaces. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2591–2600, 2009
Antagonistic interaction between bicalutamide™ (Casodex®) and radiation in androgen‐positive prostate cancer LNCaP cells
Authors: Quéro Laurent , Giocanti Nicole , Hennequin Christophe , Favaudon Vincent
Published: November 2009

BACKGROUND

Bicalutamide™ (Casodex®) reportedly improves high‐risk prostate cancer survival as an adjuvant treatment following radiotherapy. However, biological data for the interaction between bicalutamide and ionizing radiation in concomitant association are lacking.

METHODS

To explore this issue, androgen‐dependent (LNCaP) and ‐independent (DU145) human prostate cancer cells were exposed for 48 hr to 20, 40, or 80 µM bicalutamide introduced before (neoadjuvant), during (concomitant), or following (adjuvant) radiation. Growth inhibition and cytotoxicity, cell cycle distribution and expression of the prostate serum antigen (PSA) and androgen receptor (AR), were measured as endpoints.

RESULTS

Bicalutamide‐induced cytotoxic and cytostatic effects were found to be correlated with a marked G1 phase arrest and S phase depression. The drug down‐regulated PSA and AR proteins and psa mRNA in LNCaP cells. However, transient up‐regulation of the expression of ar mRNA was observed in the presence of 40 µM drug. DU145 cells did not express PSA and proved to be comparatively resistant to the drug from both cytostatic and cytotoxic effects. Bicalutamide dose‐dependently induced a significant decrease of radiation susceptibility among drug survivors in LNCaP cells, whilst the interaction appeared to be additive in DU145 cells.

CONCLUSIONS

The antagonistic radiation–drug interaction observed in LNCaP cells is of significance in relation to combined radiotherapy–bicalutamide treatments directed against tumors expressing the AR. The results suggest that bicalutamide is amenable to combined schedule with radiotherapy provided the drug and radiation are not given in close temporal proximity. Prostate 70: 401–411, 2010. © 2009 Wiley‐Liss, Inc.
Nicotinoid and pyrethroid insecticide resistance in houseflies (Diptera: Muscidae) collected from Florida dairies
Authors: Kaufman Phillip E , Nunez Sonia C , Mann Rajinder S , Geden Christopher J , Scharf Michael E
Published: November 2009

BACKGROUND: The housefly, Musca domestica L., continues to be a major pest of confined livestock operations. Houseflies have developed resistance to most chemical classes, and new chemistries for use in animal agriculture are increasingly slow to emerge. Five adult housefly strains from four Florida dairy farms were evaluated for resistance to four insecticides (beta‐cyfluthrin, permethrin, imidacloprid and nithiazine).

RESULTS: Significant levels of tolerance were found in most field strains to all insecticides, and in some cases substantial resistance was apparent (as deduced from comparison with prior published results). At the LC90 level, greater than 20‐fold resistance was found in two of the fly strains for permethrin and one fly strain for imidacloprid. Beta‐cyfluthrin LC90 resistance ratios exceeded tenfold resistance in three fly strains. The relatively underutilized insecticide nithiazine had the lowest resistance ratios; however, fourfold LC90 resistance was observed in one southern Florida fly strain. Farm insecticide use and its impact on resistance selection in Florida housefly populations are discussed.

CONCLUSION: Housefly resistance to pyrethroids is widespread in Florida. Imidacloprid resistance is emerging, and tolerance was observed to both imidacloprid and nithiazine. If these insecticides are to retain efficacy, producer use must be restrained. Copyright © 2009 Society of Chemical Industry
Potential of piperonyl butoxide‐synergised pyrethrins against psocids (Psocoptera: Liposcelididae) for stored‐grain protection
Authors: Nayak Manoj K
Published: November 2009

BACKGROUND: Piperonyl butoxide (PB)‐synergised natural pyrethrins (pyrethrin:PB ratio 1:4) were evaluated both as a grain protectant and a disinfestant against four Liposcelidid psocids: Liposcelis bostrychophila Badonnel, L. entomophila (Enderlein), L. decolor (Pearman) and L. paeta Pearman. These are key storage pests in Australia that are difficult to control with the registered grain protectants and are increasingly being reported as pests of stored products in other countries. Firstly, mortality and reproduction of adults were determined in wheat freshly treated at 0.0, 0.75, 1.5, 3 and 6 mg kg−1 of pyrethrins + PB (1:4) at 30 ± 1 °C and 70 ± 2% RH. Next, wheat treated at 0.0, 1.5, 3 and 6 mg kg−1 of pyrethrins + PB (1:4) was stored at 30 ± 1 °C and 70 ± 2% RH and mortality and reproduction of psocids were assessed after 0, 1.5, 3 and 4.5 months of storage. Finally, the potential of synergised pyrethrins as a disinfestant was assessed by establishing time to endpoint mortality for adult psocids exposed to wheat treated at 3 and 6 mg kg−1 of synergised pyrethrins after 0, 3, 6, 9 and 12 h of exposure.

RESULTS: Synergised pyrethrins at 6 mg kg−1 provided 3 months of protection against all four Liposcelis spp., and at this rate complete adult mortality of these psocids can be achieved within 6 h of exposure.

CONCLUSION: Piperonyl butoxide‐synergised pyrethrins have excellent potential both as a grain protectant and as a disinfestant against Liposcelidid psocids. Copyright © State of Queensland, Department of Employment, Economic Development and Innovation, 2010. Published by John Wiley and Sons, Ltd.
Drift mobility of photocarriers on Zn‐ and O‐polar surfaces of ZnO
Authors: Yamaguchi Hiroyuki , Komiyama Takao , Chonan Yasunori , Ishidsuka Yousuke , Ito Ryouta , Aoyama Takashi
Published: November 2009

Photocurrent transients were measured at the two polar surfaces of ZnO single crystals with an experimental arrangement of the TOF technique. The slopes of initial decays of photocurrent became steeper with the applied voltages. The change in transit time must be responsible for the change in the shape of photocurrent transient. Absolute values of mobility are estimated for photocarriers generated at the Zn‐surface and the O‐surface. Large slow photocurrent was observed for carriers generated at the O‐surface. It is plausible that there exist trap levels with high density at the O‐surface. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Annealing simulations to determine the matrix interface structure of SiC quantum dots embedded in SiO2
Authors: Knaup Jan M. , Vörös Márton , Déak Peter , Gali Adam , Frauenheim Thomas , Kaxiras Efthimios
Published: November 2009

We use the Density Functional based Tight‐Binding (SCC‐DFTB) method in a Quantum Mechanics/Molecular Mechanics embedding scheme to simulate single SiC quantum dots of different shapes and with diameters of up to 1 nm, embedded in a block of α ‐Quartz with cell vectors of a = 15 nm and c = 13 nm.

First results show that during the annealing process three recurring motives appear at the SiC/SiO2 interface of the embedded nanocrystals: Si‐Si bonds often in Si interstitial‐like configurations, C‐C bonds involving all possible combinations of sp3 and sp2 hybridized carbon and threefold coordinated oxygen atoms. All of these defects, alone or in complexes, may play a crucial role in quenching the luminescence of these embedded nanocrystals. Detailed studies of the spectroscopic properties if the point defects identified in this work is indicated (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interface with organic molecules: Cysteine on Au(110)
Authors: Höffling Benjamin , Ortmann Frank , Hannewald Karsten , Bechstedt Friedhelm
Published: November 2009

We study the adsorption of the amino acid cysteine on the Au(110) surface by means of density functional theory. Different adsorbate‐substrate geometries are investigated regarding geometry, adsorption energy, and changes in the density of states.

In particular we compare flat versus upright adsorption configurations in which the molecule registers to the surface via a deprotonized thiolate head group and eventually the amino side group. Sulfur‐gold and amino‐gold bonding geometries are discussed with their implications for electronic properties (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dielectric functions of Si nanoparticles within a silicon nitride matrix
Authors: Keita A.‐S. , Naciri A. En , Delachat F. , Carrada M. , Ferblantier G. , Slaoui A.
Published: November 2009

We report on the study of the influence of ammonia flow on physical properties of Plasma Enhanced Chemical Vapor Deposition (PECV)‐grown silicon nanoparticles (np‐Si) within a silicon nitride matrix. To achieve this goal, we have used spectroscopic ellipsometry (SE) to determine the np‐Si dielectric functions (DFs). On the one hand, the DF have been modeled using single parametric oscillators given by Tauc‐Lorentz and Forouhi‐Bloomer dispersion models. On the other hand, wavelength‐by‐wavelength numerical inversion, carried out without considering any fitting parameter, have represented another way to derive the DFs of the np‐Si. Besides a comparison has been done between results given by Bruggeman Effective Medium Approximation (BEMA) and Maxwell‐Garnett law. The results have shown that SE can be used to find out the band gap and mean size of np‐Si according to quantum confinement theory. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure and effective masses in strained silicon
Authors: Bouhassoune Mohammed , Schindlmayr Arno
Published: November 2009

The structural and electronic properties of strained silicon are investigated quantitatively with ab initio computational methods. For this purpose we combine densityfunctional theory within the local‐density approximation and the GW approximation for the electronic self‐energy. From the variation of the total energy as a function of applied strain we obtain the elastic constants, Poisson ratios and related structural parameters, taking a possible internal relaxation fully into account. For biaxial tensile strain in the (001) and (111) planes we then investigate the effects on the electronic band structure. These strain configurations occur in epitaxial silicon films grown on SiGe templates along different crystallographic directions.

The tetragonal deformation resulting from (001) strain induces a valley splitting that removes the sixfold degeneracy of the conduction‐band minimum. Furthermore, strain in any direction causes the band structure to warp. We present quantitative results for the electron effective mass, derived from the curvature of the conduction band, as a function of strain and discuss the implications for the mobility of the charge carriers. The inclusion of proper self‐energy corrections within the GW approximation in our work not only yields band gaps in much better agreement with experimental measurements than the localdensity approximation, but also predicts slightly larger electron effective masses (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interface bands in carbon nanotube superlattices
Authors: Jaskólski W. , Pelc M. , Santos H. , Chico L. , Ayuela A.
Published: November 2009

We study the electronic band structure of several carbon nanotube superlattices built of two kinds of intermolecular junctions: (12, 0)/(6, 6) and (8, 0)/(14, 0). In particular, we focus on the energy bands originating from interface states. We find that in case of the metallic (12, 0)/(6, 6) superlattices, the interface bands change periodically their character from bonding‐ to antibonding‐like vs. increasing length of the (6, 6) tube.

We show that these changes are related to the decay of the charge density Friedel oscillations in the metallic (6, 6) tube. However, when we explore other chiralities without rotational symmetry, no changes in bondingantibonding character are observed for semiconductor superlattices, as exemplified in the case of (8, 0)/(14, 0) superlattices. Our results indicate that unless metallic tubes are employed in the junctions, the bondingantibonding crossings are not present (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of [U‐13C6]glucose in human plasma using liquid chromatography/isotope ratio mass spectrometry compared with two other mass spectrometry techniques
Authors: Schierbeek Henk , Moerdijk‐Poortvliet Tanja C. W. , van den Akker Chris H. P. , te Braake Frans W. J. , Boschker Henricus T. S. , van Goudoever Johannes B.
Published: November 2009

The use of stable isotope labelled glucose provides insight into glucose metabolism. The 13C‐isotopic enrichment of glucose is usually measured by gas chromatography/mass spectrometry (GC/MS) or gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). However, in both techniques the samples must be derivatized prior to analysis, which makes sample preparation more labour‐intensive and increases the uncertainty of the measured isotopic composition. A novel method for the determination of isotopic enrichment of glucose in human plasma using liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) has been developed. Using this technique, for which hardly any sample preparation is needed, we showed that both the enrichment and the concentration could be measured with very high precision using only 20 µL of plasma. In addition, a comparison with GC/MS and GC/IRMS showed that the best performance was achieved with the LC/IRMS method making it the method of choice for the measurement of 13C‐isotopic enrichment in plasma samples. Copyright © 2009 John Wiley & Sons, Ltd.
Detection of pathogenic Verticillium spp. using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Tao Jie , Zhang Guiming , Jiang Zide , Cheng Yinghui , Feng Jianjun , Chen Zhinan
Published: November 2009

Verticillium spp. have been listed by the European and Mediterranean Plant Protection Organization (EPPO) and China as plant quarantine pests. Although attempts have been made to develop a simple routine laboratory assay to detect these organisms, none are routinely used. We describe for the first time a robust assay for reliable identification of Verticillium spp. using protein fingerprinting data obtained by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry(MALDI‐TOF‐MS). Several sample preparation methods and matrices were investigated to improve mass spectra for the routine identification of six species of Verticillium spp.(Verticillium dahiliae, V. alboatrum, V. fungicola, V. nigrescens, and V. lecanii) by MALDI‐TOF‐MS. Using the optimized experimental method, we constructed a protein fingerprint database for six species of Verticillium and established a analysis criteria of log(Score). This MALDI‐TOF‐MS protocol should prove useful as a rapid and reliable assay for distinguishing different Verticillium spp. Copyright © 2009 John Wiley & Sons, Ltd.
Investigation of the photochemical behaviour of pyrethroids lacking the cyclopropane ring by photo‐solid‐phase microextraction and gas chromatography/mass spectrometry
Authors: Fernandez‐Alvarez Maria , Llompart Maria , Garcia‐Jares Carmen , Dagnac Thierry , Lores Marta
Published: November 2009

The characterization of by‐products arising from the UV photodegradation of two insecticide pyrethroids lacking the cyclopropane ring (flucythrinate and fenvalerate) has been investigated by gas chromatography coupled with mass spectrometry (GC/MS). Twenty photoproducts were tentatively identified mainly based on the interpretation of the experimental mass spectra or by using reference mass spectra. Some of these compounds had not previously been detected. Furthermore, the generation of some of the photoproducts might be a matter for concern due to their potential toxicity. The corresponding photodegradation routes, including postulation of the intermediate radicals, have also been proposed. These photodegradation studies were performed by photo‐solid‐phase microextraction (photo‐SPME) in which the SPME fibre was exposed to light after extraction of the target analytes from aqueous solutions. The degradation kinetics of the investigated pyrethroids and the photoformation‐photodegradation curves of the photoproducts generated in situ were also monitored through the ion chromatograms obtained for different irradiation times and the corresponding mass spectra. Copyright © 2009 John Wiley & Sons, Ltd.
Isotope abundance analysis for improved sample identification with tandem mass spectrometry
Authors: Alon Tal , Amirav Aviv
Published: November 2009

Tandem mass spectrometry (MS/MS) is widely used for trace level sample analysis in complex mixtures. However, sample identification in MS/MS is challenging and not as trustworthy as with electron ionization (EI) mass spectral libraries. This paper presents a novel method for the combination of isotope abundance analysis (IAA) and EI‐MS/MS for improved sample identification even at trace level in complex matrices. Accordingly, the first quadrupole is scanned in a narrow range around the molecular ion group of isotopomers such as M+, [M+1]+ and [M+2]+, Q2 serves for collision‐induced dissociation to produce product ions while Q3 transfers the major sample product ions with low resolution, thus encompassing and uniformly transmitting all the product ion isotopomers. IAA can then be used to derive elemental formula information from the cleansed experimental data. IAA‐MS/MS was experimentally tested with perfluorotributylamine and a very good matching factor of 995 (out of 1000) was obtained for IAA on m/z 502, 503 and 504 (fragment ion isotopomers) while Q3 transmitted the m/z 264 product ion with a mass window of 6 m/z units. The IAA‐MS/MS method was further tested with the pesticide diazinon on its molecular ions m/z 304, 305 and 306 while Q3 was locked on its m/z 179 product ion with a mass window of 6 m/z units. Again, very good matching factors were obtained, even for 40 pg diazinon on‐column during its GC/MS analysis (match = 981). IAA‐MS/MS combines the traditional benefits of MS/MS in the removal of matrix interferences with the IAA power of elemental analysis. Copyright © 2009 John Wiley & Sons, Ltd.
Investigation of the identification point system adaptation in cocaine, benzoylecgonine and ecgonine methyl ester using a single quadrupole mass spectrometer
Authors: Pistos C. , Karampela S. , Papoutsis I. , Athanaselis S. , Spiliopoulou Ch. , Maravelias C.
Published: November 2009

At present, no official criteria exist for drug identification using single quadrupole mass spectrometers although the European Union (EU) criteria for compound identification have been adopted. These criteria are evaluated with respect to the confirmation of cocaine and its metabolites by single quadrupole liquid chromatography/mass spectrometry (LC/MS) and problems are highlighted. Spiked samples, proficiency testing samples, certified reference materials and samples from real cases that had screened positive for cocaine derivatives by immunoassay were subjected to confirmation by LC/MS using single ion monitoring with in‐source fragmentation. The EU criteria for compound identification were applied for the confirmation of cocaine, benzoylecgonine and ecgonine methyl ester. The use of the identification point (IP) system in spiked, proficiency testing samples and certified reference materials provided acceptable results in all cases while in some cases real positive samples did not provide acceptable results. Failure to meet the EU criteria was attributed to low fragmentation at the lower concentrations and the ion suppression effect while both factors affected compliance with the IP system. The identification of cocaine and its metabolites was considerably improved by using a combination of ammonium formate and formic acid as the LC mobile phase. It appears that poor in‐source fragmentation in single quadrupole LC/MS and ion suppression may constitute a problem with drug identification when implementing the IP system in real samples, resulting in false negative results. Further investigation is needed for the use of such IP systems to be suitable for use in LC/MS methods. Copyright © 2009 John Wiley & Sons, Ltd.
Comprehensive analysis of short peptides in sera from patients with IgA nephropathy
Authors: Kaneshiro Nagayuki , Xiang Yang , Nagai Kouhei , Kurokawa Manae S , Okamoto Kazuki , Arito Mitsumi , Masuko Kayo , Yudoh Kazuo , Yasuda Takashi , Suematsu Naoya , Kimura Kenjiro , Kato Tomohiro
Published: November 2009

We analyzed serum short peptides comprehensively to know whether they were useful to characterize IgA nephropathy (IgAN). Serum samples from 26 patients with untreated IgAN and 25 healthy donors were tested. Short peptides with molecular weights of ∼7 kDa, purified from the serum samples by magnetic‐beads‐based weak cation exchange, were detected by mass spectrometry. Then the peptide peaks detected were subjected to the multivariate data analysis by SIMCA‐P+® containing principal component analysis (PCA) and orthogonal partial‐least‐squares‐discriminate analysis (OPLS‐DA). A total of 92 peptide peaks were detected in the tested serum samples. The OPLS‐DA analysis revealed that the profile of all the peptide peak intensities discriminated the IgAN group and the healthy group completely with a high R2 value (0.919) and a high Q2 value (0.861). Further, the profile of only five peptide peaks was found to discriminate the two groups. By tandem mass spectrometry and database searching, three of the five peptides which increased in the IgAN group were identified as fragments of fibrinogen alpha chain, and the two peptides which increased in the healthy group were identified as fragments of complement C3f and kininogen‐1 light chain. Taken together, the profile of the serum short peptides would be useful to discriminate IgAN and healthy conditions. Further, the five peptides may be candidate serum markers for IgAN and may be related to pathogenesis of IgA. Copyright © 2009 John Wiley & Sons, Ltd.
Reverse thin layer method for enhanced ion yield of oligosaccharides in matrix‐assisted laser desorption/ionization
Authors: Nishikaze Takashi , Amano Junko
Published: November 2009

A sample preparation method that is suitable for sensitive detection of underivatized oligosaccharides by matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) has been investigated. As compared with the conventional dried‐droplet or ethanol (EtOH) recrystallization method, superior mass spectra in terms of ion yield and signal‐to‐noise (s/n) ratio were obtained when methanol (MeOH) was used as a solvent for the mixture of matrix and oligosaccharides. Based on these results, a new sample preparation method, named the ‘reverse thin layer method’, was developed. This method comprises two steps: first, complete drying of the oligosaccharide solution on the MALDI target plate; and second, deposition of the matrix dissolved in a small amount of MeOH. Using this method, a relatively homogeneous matrix crystal was generated and higher yields of both positive and negative ions were obtained from oligosaccharides compared with conventional methods. Notably, the method can be applied to various matrices including both solid and liquid matrices. Copyright © 2009 John Wiley & Sons, Ltd.
Real‐time trace detection and identification of chemical warfare agent simulants using recent advances in proton transfer reaction time‐of‐flight mass spectrometry
Authors: Petersson Fredrik , Sulzer Philipp , Mayhew Chris A. , Watts Peter , Jordan Alfons , Märk Lukas , Märk Tilmann D.
Published: November 2009

This work demonstrates for the first time the potential of using recent developments in proton transfer reaction mass spectrometry for the rapid detection and identification of chemical warfare agents (CWAs) in real‐time. A high‐resolution (m/Δm up to 8000) and high‐sensitivity (∼50 cps/ppbv) proton transfer reaction time‐of‐flight mass spectrometer (PTR‐TOF 8000 from Ionicon Analytik GmBH) has been successfully used to detect a number of CWA simulants at room temperature; namely dimethyl methylphosphonate, diethyl methylphosphonate, diisopropyl methylphosphonate, dipropylene glycol monomethyl ether and 2‐chloroethyl ethyl sulfide. Importantly, we demonstrate in this paper the potential to identify CWAs with a high level of confidence in complex chemical environments, where multiple threat agents and interferents could also be present in trace amounts, thereby reducing the risk of false positives. Instantaneous detection and identification of trace quantities of chemical threats using proton transfer reaction mass spectrometry could form the basis for a timely warning system capability with greater precision and accuracy than is currently provided by existing analytical technologies. Copyright © 2009 John Wiley & Sons, Ltd.
Cooperative control of multiple surface vessels in the presence of ocean currents and parametric model uncertainty
Authors: Almeida J. , Silvestre C. , Pascoal A.
Published: November 2009

This paper addresses the problem of cooperative path‐following of multiple autonomous vehicles. Stated briefly, the problem consists of steering a group of vehicles along specified paths while keeping a desired spatial formation. For a given class of autonomous surface vessels, it is shown how Lyapunov‐based techniques and graph theory can be brought together to design a decentralized control structure, where the vehicle dynamics and the constraints imposed by the topology of the inter‐vehicle communication network are explicitly taken into account. To achieve path‐following for each vehicle, a nonlinear adaptive controller is designed that yields convergence of the trajectories of the closed‐loop system to the path in the presence of constant unknown ocean currents and parametric model uncertainty. The controller derived implicitly compensates for the effect of the ocean current without the need for direct measurements of its velocity. Vehicle cooperation is achieved by adjusting the speed of each vehicle along its path according to information exchanged on the positions of a subset of the other vehicles, as determined by the communication topology adopted. Global stability and convergence of the closed‐loop system are guaranteed. Illustrative examples are presented and discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Interfacial reactions in an interpenetrating polymer network thin film on an aluminum substrate
Authors: Tang Dongyan , Guo Yudi , Zhang Xiaohong , Liu Jie
Published: November 2009

We have adopted the dip‐pulling method and a thinning technique to obtain interpenetrating polymer network (IPN) thin films with suitable thickness and adhesive strength on Al substrates. X‐ray photoelectron spectroscopy (XPS) and attenuated total reflection infrared spectroscopy (ATR‐FTIR) were used to study the interfacial reactions, metal transformations, and nonmetal bond types between IPN and Al. By probing the binding energy shifts of nitrogen, aluminum, and oxygen atom species at different IPN/Al interfacial layers, the reactions between the polyurethane in IPN and the OH group in aluminum substrate could be determined. Moreover, the additional structures formed by the double bond between the nitrogen and nitrogen in the NCO group in IPN suggested the existence of covalent bonding in the adhesion areas. Sufficient interfacial reactions occurring between IPN and Al effectively restricted the IPN peel off from Al substrate. Copyright © 2009 John Wiley & Sons, Ltd.
Bayesian spatial modeling of disease risk in relation to multivariate environmental risk fields
Authors: Kim Ji‐in , Lawson Andrew B. , McDermott Suzanne , Aelion C. Marjorie
Published: November 2009

The relationship between exposure to environmental chemicals during pregnancy and early childhood development is an important issue that has a spatial risk component. In this context, we have examined mental retardation and developmental delay (MRDD) outcome measures for children in a Medicaid population in South Carolina and sampled measures of soil chemistry (e.g. As, Hg, etc.) on a network of sites that are misaligned to the outcome residential addresses during pregnancy. The true chemical concentration at the residential addresses is not observed directly and must be interpolated from soil samples. In this study, we have developed a Bayesian joint model that interpolates soil chemical fields and estimates the associated MRDD risk simultaneously. Having multiple spatial fields to interpolate, we have considered a low‐rank Kriging method for the interpolation that requires less computation than the Bayesian Kriging. We performed a sensitivity analysis for a bivariate smoothing, changing the number of knots and the smoothing parameter. These analyses show that a low‐rank Kriging method can be used as an alternative to a full‐rank Kriging, reducing the computational burden. However, the number of knots for the low‐rank Kriging model needs to be selected with caution as a bivariate surface estimation can be sensitive to the choice of the number of knots. Copyright © 2009 John Wiley & Sons, Ltd.
Tuning Array Morphology for High‐Strength Carbon‐Nanotube Fibers
Authors: Zheng Lianxi , Sun Gengzhi , Zhan Zhaoyao
Published: November 2009

Vertically aligned carbon‐nanotube arrays are synthesized by chemical vapor deposition. Carbon‐nanotube fibers are directly spun from the obtained nanotube arrays and then tested mechanically. A strong correlation between the array morphologies and the mechanical properties of the fibers is observed: well‐aligned arrays yield fibers with much higher performance, while wavy and entangled arrays give poor fiber properties. More importantly, such array morphologies could be controlled by introducing hydrogen or oxygen during the nanotube synthesis. By simply switching the growth condition from 150 ppm oxygen addition to 2% hydrogen addition, the nanotube array changes from the wavy morphology to the well‐aligned morphology, and correspondingly the tensile strength of the resultant fibers could be increased by 4.5 times, from 0.29 GPa for the fibers spun from the oxygen‐assistance‐grown nanotube arrays to 1.3 GPa for the fibers spun from the hydrogen‐assistance‐grown nanotube arrays. The detailed effects of hydrogen and oxygen on the nanotube growth, especially on the growth rate and the array spinnability, are extensively studied. The formation mechanism of the different morphologies of the nanotube arrays and the failure mechanism of the nanotube fibers are also discussed in detail.
Size‐Selective Effects on Fullerene Adsorption by Nanoporous Molecular Networks
Authors: Shen Yong‐Tao , Deng Ke , Zeng Qing‐Dao , Wang Chen
Published: November 2009

A new hierarchical self‐assembling molecular template, which can size‐selectively immobilize fullerene molecules, is reported. The molecular template is fabricated from 1,3,5‐tris(10‐carboxydecyloxy)benzene (TCDB) and triangle‐shaped macrocycles. It is observed that the two‐dimensional hydrogen‐bonded achiral TCDB network affected by the 3NN‐Macrocycle becomes a chiral network. Host and guest molecules both form chiral arrangements with hexagonal empty pores. In addition, fullerenes and other molecules such as coronene can be entrapped in the empty pores or on the 3NN‐Macrocycle molecules. The adsorption constant (K) is estimated, from which it is concluded that the different filling behaviors of the fullerenes are associated with the different sizes of the guest species. This method provides a facile approach to molecularly designed surfaces and the study of fullerene molecular arrays on the single‐molecule level.
Change and continuity in the recent 30 years of research on modern Chinese history: Some unsystematic reflective thoughts
Authors: Zhitian LUO
Published: November 2009

Research on modern Chinese history in the past 30 years can be equally divided into two parts, which are different in terms of attended issues, observed objects, and investigated topics, and also employ different perspectives to explore “problems,” utilize different materials, and resort to different formats for narration. To understand this “thirty-year” (post-1978) historiography, it is necessary to go back to the “seventeen-year” (1949–1966) research before the Cultural Revolution and examine and analyze these studies for trends of continuity and fracture in the accumulation of scholarship. On the other hand, future research should be cautious about even an unconscious tendency of self-isolation, keep an open mind, and fully consider the numerous foreign elements “present in China” in the modern period, their consequences, and impact.
Temple community of folk religion in Jiangnan since the Ming and Qing dynasties: Focus on Suzhou and Songjiang areas
Authors: Jian WANG
Published: November 2009

The temple community is an important concept in Suzhou and Songjiang folk religion since the Ming and Qing dynasties. The two major types of temple communities were those surrounding a Tudi Temple (Temple of the god of land), those encircling a Chenghuang Temple (Temple of the City God), and a Mount Tai Temple. Their existence has different meanings. The organizational systems and varying kinds of religious activities were distinct to the different temple communities. However, the division of temple communities is closely related to local administrative divisions. It is worth noticing that temple communities compete and conflict with each other for regional development resources and the benefits of relevant groups. This study of temple communities contributes to our overall understanding of communities of faith in villages.
A reflection on the alternative philosophy of science
Authors: Dachun LIU , Yongmou LIU
Published: November 2009

A prominent phenomenon in contemporary philosophy of science has been the unexpected rise of alternative philosophers of science. This article analyses in depth such alternative philosophers of science as Paul Feyerabend, Richard Rorty, and Michel Foucault, summarizing the similarities and differences between alternative philosophies of science and traditional philosophy of science so as to unveil the trends in contemporary philosophy of science. With its different principles and foundation, alternative philosophy of science has made breakthroughs in terms of its field of vision, scope, and methodology, and its relationship with science has become more humanistic and pluralistic. Attention should be given to alternative perspectives in the contemporary philosophy of science, and research should be expanded into the fields of the epistemology of science and cognitive science, the sociology of scientific knowledge and scientific anthropology, the scientific cultural philosophy, and scientific ethics.
Functional Recovery following an End to Side Neurorrhaphy of the Accessory Nerve to the Suprascapular Nerve: Case Report
Authors: Ray Wilson Z. , Kasukurthi Rahul , Yee Andrew , Mackinnon Susan E.
Published: November 2009

The use of end-to-side neurrorhaphy remains a controversial topic in peripheral nerve surgery. The authors report the long-term functional outcome following a modified end-to-side motor reinnervation using the spinal accessory to innervate the suprascapular nerve following a C5 to C6 avulsion injury. Additionally, functional outcomes of an end-to-end neurotization of the triceps branch to the axillary nerve and double fascicular transfer of the ulnar and medial nerve to the biceps and brachialis are presented. Excellent functional recoveries are found in respect to shoulder abduction and flexion and elbow flexion.