bluuebunny/crossref_metadata_2025 huggingface dataset:
Physicochemical properties, total phenol and tocopherol of some Acacia seed oils
Authors: Falade Olumuyiwa S , Adekunle Abolanle S , Aderogba Mutalib A , Atanda Segun O , Harwood Chris , Adewusi Steve R
Published: September 2007

BACKGROUND: Recently, there has been an increase in the number of investigations into the possible use of vegetable oils as a source of oleochemicals to supplement petrochemicals. We have therefore determined the physicochemical properties of Acacia oils and compared them with groundnut oil as a first step toward their possible industrial utilization.

RESULTS: The chemical properties of Acacia oils compared well and surpassed those of groundnut oil in iodine value (1549.3, 1783.3 and 1093.1 g iodine kg−1 oil for A. colei, A. tumida and groundnut oils, respectively), saponification value (201.74, 202.15 and 198.01 g KOH kg−1 oil for A. colei, A. tumida and groundnut oils, respectively). Total phenol and tocopherol content of Acacia oils were also higher compared with groundnut oil. Refractive index, specific gravity and viscosity were higher in Acacia seed oils than in groundnut oil but the smoke point of Acacia oil was lower than that of groundnut oil. Acacia oils were higher in some essential elements (Mg, Ca, Fe, Zn and Cu) when compare with groundnut oil.

CONCLUSION: The properties of Acacia oils revealed that they could be useful as drying oils, in soap making and as lubricants at low temperatures. They could also be dietary sources of natural antioxidants and essential elements. Copyright © 2007 Society of Chemical Industry
Determination of decabromodiphenyl ether in water samples by single‐drop microextraction and RP‐HPLC
Authors: Li Yanyan , Wei Guohui , Wang Xuedong
Published: September 2007

This paper describes the development of a new method using single‐drop microextraction (SDME) and RP‐HPLC for the determination of decabromodiphenyl ether (BDE‐209) in water samples. The effects of SDME parameters such as extraction solvent, microdrop volume, extraction time, stirring speed, salt concentration, and sample pH on the extraction performance are investigated. Under optimal extraction conditions (extraction solvent, toluene; solvent drop volume, 3.0 μL; extraction time, 15 min; stirring speed, 600 rpm; no addition of salt and change of sample pH), the calibration curve was drawn by plotting peak area against a series of BDE‐209 concentrations (0.001–1 μg/mL) in aqueous solution; the correlation coefficient (r) was 0.9998. The limit of detection was 0.7 ng/mL. The enrichment factor was 10.6. The precision of this method was obtained by six successive analyses of a 100 ng/mL standard solution of BDE‐209, and RSD was 4.8%. This method was successfully applied to the extraction of BDE‐209 from tap and East Lake water samples with relative recoveries ranging from 92.5 to 102.8% and from 91.5 to 96.2%, respectively, and the relative standard deviations (n = 3) were 4.4 and 2.2%. The proposed method is acceptable for the analysis of BDE‐209 in water samples.
Determination of sulphonamides in animal tissues by high performance liquid chromatography with pre‐column derivatization of 9‐fluorenylmethyl chloroformate
Authors: Zou Qiong‐Hui , Xie Meng‐Xia , Wang Xiang‐Feng , Liu Yuan , Wang Jin , Song Jia , Gao Hui , Han Jie
Published: September 2007

A novel approach for simultaneous determination of 12 sulphonamides (sulphadiazine, sulphamethazine, sulphathiazole, sulphadimethoxine, sulphamerazine, sulphapyridine, sulphamethoxazole, suphamethizole, sulphaquinoxaline, sulphameter, sulphamonomethoxine, and sulphachloropyridazine) in animal tissues (swine muscle and liver, chicken muscle, beef muscle) by HPLC with UV detection has been developed. A pre‐column derivatization of the sulphonamide compounds with 9‐fluorenylmethyl chloroformate (FMOC‐Cl) has been proposed and the reaction conditions have been optimized. The FMOC‐sulphonamide derivatives were purified by SPE with silica gel as solid support prior to HPLC separation. The limits of detection for the sulphonamide compounds were greatly improved after the derivatization and purification step for the derivatives. Sulphonamide residues in animal tissues were extracted by acetonitrile and purified by solid phase extraction with C18 as the solid support. The method developed has high sensitivity and good repeatability, and the average recoveries for most of the sulphonamides at various spiking levels were above 70% with relative standard deviations below 13.7%. The limits of detection for most sulphonamides can reach 3–5 μg/kg.
Visitor motivation, satisfaction and behavioural intention: the 2005 Naadam Festival, Ulaanbaatar
Authors: Schofield Peter , Thompson Karen
Published: September 2007

The study investigates visitor motivation for attending the 2005 Naadam Festival in Ulaanbaatar, Mongolia. It identifies motivation variance on the basis of socio‐demographic variables and examines the factors of significance with regard to visitor satisfaction and intention to revisit the festival. Five motivation dimensions, consistent with those identified in previous research, were identified. The horse riding and wrestling events were the most satisfying aspects of the festival from the visitor perspective, followed by Naadam's uniqueness, the opening ceremony and the authenticity of the festival. Significant differences in motivation dimensions, satisfaction and intention to revisit the festival were found on the basis of visitor origin, gender and age. The theoretical and practical implications of the findings are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Channel-spacing and wavelength switchable multiwavelength erbium-doped fiber laser using sampled Hi-Bi fiber grating and photonic crystal fiber loop mirror
Authors: Liu Z-Y , Liu Y-G , Du J-B , Yuan S-Z , Dong X-Y
Published: September 2007

We propose and demonstrate a stable room-temperature channel-spacing and wavelength switchable multiwavelength erbium-doped fiber (EDF) laser using a sampled Hi-Bi fiber grating and a photonic crystal fiber (PCF) loop mirror. The PCF loop mirror induces the intensity-dependent cavity loss to suppress the wavelength competition of the EDF. By adjusting the polarization controller, we can achieve 0.4 nm and 0.8 nm channel-spacing of the multiwavelength EDF laser. The measured power fluctuation of each wavelength is less than 0.2 dB and the peak power differences among the main oscillation wavelengths are less than 1.0 dB. Another desirable characteristic is that it needs a relatively low pump power of 100 mW.
The radiation amplification effect in the scattering of a quasi-classical electron by an ion in the weak electromagnetic field
Authors: Freiv A V , Roshchupkin S P
Published: September 2007

Possibility of amplification of electromagnetic radiation is theoretically studied in the scattering of a quasi-classical electron by an ion in the field of weak linearly polarized wave. Using the limiting process of the total cross-section at small values of adiabaticity parameter to Krainov's formula, the symmetrization of Berson's formula was performed. Expression for the total cross-section (the gain coefficient) for the wide interval of values of adiabaticity parameter was obtained. It was shown, that the wave amplification takes place in the range of values of adiabaticity parameter more than two and can be sufficiently large.
Calculations regarding cell metabolism stimulation using photons in the visible wavelength range
Authors: Scheller E E , Rohde E , Minet O , Müller G , Bindig U
Published: September 2007

The driving force behind the complex system of metabolism is based on the efficient use of potential differences. An intact biological system has a dynamic equilibrium in which the cellular biochemical reactions are in a pseudo-stationary state. The equilibrium can be manipulated by external effects such as, temperature changes brought about radiation absorption. Hot spots can be induced by the absorption of photons in strongly absorbing areas within the tissue or the sub-cellular components. Simulation calculations were carried out and utilized for selective manipulation within a spatially limited target volume, using simplified parameters for observation of the model. A good correlation was established between the results of the simulation and the measuring data based on absorption and scattering values for fibroblasts and liver tissue. Relevant biochemical causes of the stimulation effects at cellular level are considered in the discussion. The effect of stimulation with a laser on tissue such as cartilage, using a simplified two-dimensional tissue model system which is mainly supplied by diffusion processes, is discussed here with a view to its use in medicine.
Ipratropium bromide spray as treatment for sialorrhea in Parkinson's disease
Authors: Thomsen Teri R. , Galpern Wendy R. , Asante Abena , Arenovich Tamara , Fox Susan H.
Published: September 2007

Sialorrhea is a significant problem in advanced Parkinson's disease (PD). Current treatment options include systemic anticholinergics which frequently cause side effects. We hypothesized that sublingual application of ipratropium bromide spray, an anticholinergic agent that does not cross the blood brain barrier, may reduce drooling without systemic side effects. We performed a randomized, double blind, placebo‐controlled, crossover study in 17 subjects with PD and bothersome drooling. Patients were randomized to receive ipratropium bromide or placebo (one to two sprays, maximum of four times per day) for 2 weeks followed by a 1 week washout and crossover for further 2 weeks of treatment. The primary outcome was an objective measure of weight of saliva production. Secondary outcomes were subjective rating of severity and frequency of sialorrhoea using home diaries, United Parkinson's Disease Rating Scale (UPDRS) part II salivation subscore, parkinsonian disability using UPDRS, and adverse events. Ipratropium bromide spray had no significant effect on weight of saliva produced. There was a mild effect of treatment on subjective measures of sialorrhea. There were no significant adverse events. Ipratropium bromide spray was well tolerated in subjects with PD. Although it did not affect objective measures of saliva production, further studies in parkinsonism may be warranted. © 2007 Movement Disorder Society
Withdrawal of visual feedback improves micrographia in Parkinson's disease
Authors: Ondo William G. , Satija Pankaj
Published: September 2007

Micrographia is a common, often presenting feature of Parkinson's disease. We assessed a simple writing paradigm in 40 PD patients “off” medications, 40 different PD patients “on” medications, and 64 age‐ and sex‐matched controls. Patients wrote “Today is a nice day” with both eyes open and eyes closed to assess the effects of visual withdrawal (eyes closure). The order (eyes open vs. eyes closed) was alternated. In the “off” medicine group, eye closure increased the writing length by 14.0 ± 10.1% (P < 0.05) from a mean of 69.1 to 77.7 mm [range −14% to +73%]. The percentage increase was larger in the 20 subjects with the smallest baseline writing size (worse micrographia), compared to the 20 with relatively larger writing (19.5% vs. 7.9%, P < 0.05). Neither the “on” medicine group, nor the control group changed. Simple eye closure significantly increased writing size in “off” PD patients to a similar or greater amount as levodopa. This data suggests that micrographia is not a pure motor hypokinetic feature but is affected by PD similar to other superlearned tasks such as walking. Furthermore, some patients have adapted this simple eye closing strategy when writing, especially signatures. © 2007 Movement Disorder Society
Design of a novel Wilkinson power splitter based on the left‐handed transmission line
Authors: Hu Jun , Xiong Jiang , Ti Ling  , Zou Yongzhuo
Published: September 2007

The present paper proposes a novel design of a Wilkinson power splitter, which utilizes the nonlinear dispersion characteristic of a left‐handed transmission line (LHTL). The proposed device has been fabricated using the lumped L‐C −λ/4 LHTLs instead of the conventional TLs to implement branch arms. It has effectively improved the bandwidth of return loss and isolation, and reduced the whole size of the device as well. The measured results show good consistent with the simulation results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2975–2977, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22896
A spherical wave expansion model of sequentially rotated phased arrays with arbitrary elements
Authors: Vesterdal Larsen Niels , Olav Breinbjerg
Published: September 2007

An analytical model of sequentially rotated phased arrays with arbitrary antenna elements is presented. It is applied to different arrays and the improvements of axial ratio bandwidth and copolar directivity are investigated. It is compared to a numerical Method of Auxiliary Sources model to ascertain the accuracy and limitations. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3148–3154, 2007; Published online in Wiley Inter‐Science (www.interscience.wiley.com). DOI 10.1002/mop.22905
CMOS power cell with improved junction breakdown using interdigitated body contact
Authors: Park Changkun , Han Jeonghu , Hong Songcheol
Published: September 2007

A power‐cell for RF power applications is designed using 0.35‐μm standard CMOS technology. An interdigitated body contact method is proposed and applied to a RF power‐cell. A total gate width of the designed power‐cell is 3.2 mm. The proposed RF power‐cell has a higher junction breakdown voltage than that of a conventional RF power‐cell. The breakdown voltage of the proposed CMOS power‐cell at zero gate voltage was found to be ∼8 V. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3085–3087, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22908
Cost‐effective metal‐plate shorted dipole antenna with wide bandwidth for WLAN/WiMAX applications
Authors: Chou Jui‐Hung , Su Saou‐Wen
Published: September 2007

A wideband shorted dipole antenna well suited to applications for WLAN/WiMAX dual‐mode operation is presented. The dipole antenna is structured to be of an L shape to fit in corners of possible wireless communications devices. Two radiating arms of the dipole antenna are further short‐circuited, which allows the antenna to be cost‐effectively fabricated by stamping a single metal plate only one time. In addition, by widening the end portion of each radiating arm, much more improved impedance matching across a wide operating bandwidth can easily be achieved. Details of the proposed dipole antenna are described, and experimental and simulation results of a design prototype are elaborated and discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3044–3046, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22911
A hybrid MM‐PO method combining UV technique for scattering from two‐dimensional target above a rough surface
Authors: He Si Yuan , Zhu Guo Qiang
Published: September 2007

In this article, an efficient hybrid MM‐PO method combining UV technique is applied to calculate the EM scattering from a 2D PEC target above a PEC rough surface. Considering the target as the MM region and the rough surface as the PO region, the current on the rough surface is obtained through the PO approximation, leaving only unknowns on the target region. Furthermore, a UV technique is used to accelerate the coupling interaction between the target and the rough surface. With this hybrid method, large scale target/rough surface scattering problems can be solved more effectively. Using the Monte‐Carlo method to generate the rough surface, the bistatic difference field radar cross‐section of the target above a Pierson‐Morkowitz rough surface is numerically simulated. The results show good agreement when compared with the other methods. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2957–2960, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22922
Enhanced bandwidth for a coplanar coupled‐line balun design
Authors: Chen Guan‐Yu , Sun Jwo‐Shiun
Published: September 2007

This letter presents a practical and simple uniplanar coupled‐line balun with lower profile coplanar waveguide (CPW) structure to enhance the coupled coefficient and balanced output bandwidth for millimeter‐wave operations. The CPW balun with a pair of symmetric quarter wavelength coupled lines is developed to increase at least 150% (1.5 times) bandwidth efficiency with a return loss better than the traditional planar coupled‐line balun. The structure of the designed balun is simple, practical, and easy to fabricate. The measured results show fine agreements with the simulated data. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2902–2905, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22926
Novel ultra‐wideband bandpass filter using DUC‐EBG unit cell
Authors: Baik J. W. , Hyun D. H. , Kim G. N. , Kim Y.‐S.
Published: September 2007

A novel ultra‐wideband (UWB) bandpass filter (BPF) in the whole UWB passband of 3.1–10.6 GHz using a distorted uniplanar compact electromagnetic band‐gap (DUC‐EBG) unit cell is presented. This DUC‐EBG unit cell is acted as a multiple‐mode resonator (MMR). To model the DUC‐EBG unit cell, an equivalent L–C circuit is used to analyze passband characteristics of the proposed filter. Its design is dealt within this letter and the one‐ and three‐stage BPF are implemented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3134–3136, 2007; Published online in Wiley Inter‐Science (www.interscience.wiley.com). DOI 10.1002/mop.22931
Phase shift of recovered clock due to group delay ripple in fiber Bragg grating and PMD
Authors: Zhang Dechao , Zhang Xiaoru , Li Xiaolin , Xu Anshi , Wang Ziyu , Zhang Fan , Chen Zhangyuan
Published: September 2007

The effect of group delay ripple in fiber bragg grating and polarization mode dispersion on the phase shift of recovered clock signal and the sampling time shift is theoretically and experimentally investigated in 42.8 Gbit/s WDM recirculating transmission, which may result in significant BER degradation in high speed transmission. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3066–3068, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22935
Microstrip multiplexer with compact in‐line feed structure
Authors: Saavedra Carlos E.
Published: September 2007

A microstrip multiplexer circuit using a compact in‐line feed structure is presented and experimentally demonstrated. The multiplexer consists of four edge‐coupled microstrip bandpass filters that are independently designed using any filter synthesis technique. The bandpass filters are interconnected in a sequential manner using specific lengths of transmission line that isolate the filters from one another at the center frequency of their passbands. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3128–3130, 2007; Published online in Wiley Inter‐Science (www.interscience.wiley.com). DOI 10.1002/mop.22945
Novel reflector‐backed Fresnel zone plate antenna
Authors: Stout‐Grandy S. M. , Petosa A. , Minin I. V. , Minin O. V. , Wight J. S.
Published: September 2007

A novel reflector‐backed Fresnel zone plate antenna (FZPA) is presented. The reflector is positioned at the aperture of the feed antenna such that the radiation that was reflected back off the metal zones of the FZPA gets reradiated instead of being lost. This structure enhances the directivity of the FZPA by about 1 dB and also improves the sidelobes and aperture efficiency. The other benefit of the structure is that it enables a significant reduction in the volume of the FZPA. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3096–3098, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22946
Ammonia gas fiber sensor based on poly‐aniline sensing film coated on superstructure fiber Bragg gratings
Authors: Ai Lung , Mau Jiang‐Chiou , Liu Wen‐Fung , Fu Ming‐Yue , Chen Tzu‐Chiang
Published: September 2007

In this study, we experimentally demonstrated that the concentrations of ammonia (NH3) gas can be detected by a fiber sensor based on the poly‐aniline (PANI) sensing film coated on the surface of an etched superstructure fiber Bragg grating (SFBG). This sensing mechanism is based on the NH3 gas to interact with the PANI‐coating film to cause the film index change and then to result in the Bragg wavelength shift. The sensitivity of this sensor is around 0.073 pm/ppm, which requires to be improved in the future for achieving a simple, reliable, repeatable, and nondestructive chemical‐gas fiber sensor. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3063–3066, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22948
Propagation characteristics of H‐plane folded substrate integrated waveguide bends
Authors: Geng Liang , Che Wenquan , Deng Kuan
Published: September 2007

The H‐plane folded substrate integrated waveguide (FSIW) bend with circular right‐angle in C band and X band are investigated in this article. The design formulas of the folded substrate integrated waveguide are proposed first, followed by the proper design principles of FSIW bends. Comparisons between FSIW bends and SIW bends have been made to demonstrate the validity of the design formulas. In addition, the propagation characteristics between FSIW sections and FSIW bends have been compared also, almost same propagation characteristics can be observed within. However, some fluctuations can be seen from the insertion losses of FSIW bends, implying the occurrence of the higher modes. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2977–2981, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22953
New formulation of iterative substructuring methods without Lagrange multipliers: Neumann–Neumann and FETI
Authors: Herrera‐Revilla Ismael
Published: September 2007

This article is devoted to introduce a new approach to iterative substructuring methods that, without recourse to Lagrange multipliers, yields positive definite preconditioned formulations of the Neumann–Neumann and FETI types. To my knowledge, this is the first time that such formulations have been made without resource to Lagrange multipliers. A numerical advantage that is concomitant to such multipliers‐free formulations is the reduction of the degrees of freedom associated with the Lagrange multipliers. Other attractive features are their generality, directness, and simplicity. The general framework of the new approach is rather simple and stems directly from the discretization procedures that are applied; in it, the differential operators act on discontinuous piecewise‐defined functions. Then, the Lagrange multipliers are not required because in such an environment the functions‐discontinuities are not an anomaly that need to be corrected. The resulting algorithms and equations‐systems are also derived with considerable detail. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
Analysis of differently expressed proteins and transcripts in gills of Penaeus vannamei after yellow head virus infection
Authors: Rattanarojpong Triwit , Wang Hao‐Ching , Lo Chu‐Fang , Flegel Timothy W.
Published: September 2007

In this proteomic analysis of gills from yellow head virus (YHV)‐infected Penaeus vannamei, we identified 13 spots with up‐regulated protein expression levels and five spots with down‐regulated levels. LC‐nanoESI‐MS/MS indicated that the up‐regulated proteins included enzymes in the glycolytic pathway, the tricarboxylic acid cycle and amino acid metabolism. The other up‐regulated proteins were arginine kinase, imaginal disk growth factor (IDGF) and a Ras‐like GTP binding protein. By contrast, expression levels were reduced for an SCP‐calcium binding protein (SCP), actin‐1, a valosin‐containing protein, and Rab11. Time‐course assays by real time RT‐PCR revealed no significant increase in mRNA level of glycolytic enzymes and arginine kinase. However, a significant decrease in SCP mRNA was observed. The present results are consistent with previously published work and suggest that a decrease in SCP expression may play an important role in the shrimp response to viral infections in general.
Glycomic mapping of pseudomucinous human ovarian cyst glycoproteins: Identification of Lewis and sialyl Lewis glycotopes
Authors: Wu Albert M. , Khoo Kay‐Hooi , Yu Shin‐Yi , Yang Zhangung , Kannagi Reiji , Watkins Winifred M.
Published: September 2007

Expression of sialyl Lewis x (sLex) and sialyl Lewis a (sLea) on cell‐surface glycoproteins endows cells with the ability to adhere to E‐, P‐, and L‐selectins present on endothelia, platelets, or leukocytes. Special arrangements of these glycotopes in cancers are thought to play a key role in metastasis. Previous studies have mostly described membrane‐bound sLex and sLea activities. In this report, the major O‐glycans of the secreted human ovarian cyst sialoglycoproteins from a Le(a+) nonsecretor individual (human ovarian cyst sample 350) were characterized by MS/MS analyses and immuno‐/lectin‐chemical assays. The results showed that HOC 350 carries a large number of epitopes for sLex, sLea, and Lea reactive antibodies. Advanced MS/MS sequencing coupled with mild periodate oxidation and exoglycosidase digestions further revealed that the O‐glycans from HOC 350 are mostly of core 1 and 2 structures, extended and branched on the 3‐arm with both type I and type II chains, complete with variable degrees of terminal sialylation and/or fucosylation to yield the sLex or sLea epitopes. Thus, the underlying core and peripheral backbone structures are similar to that of a previously proposed composite structural model for nonsialylated human ovarian cysts O‐glycans, but with some notable distinguishing structural features in addition to sialylation.
Comparative proteomes of Corynebacterium glutamicum grown on aromatic compounds revealed novel proteins involved in aromatic degradation and a clear link between aromatic catabolism and gluconeogenesis via fructose‐1,6‐bisphosphatase
Authors: Qi Su‐Wei , Chaudhry Muhammad Tausif , Zhang Yun , Meng Bo , Huang Yan , Zhao K.‐X. , Poetsch Ansgar , Jiang Cheng‐Ying , Liu Siqi , Liu Shuang‐Jiang
Published: September 2007

The current study examined the aromatic degradation and central metabolism in Corynebacterium glutamicum by proteomic and molecular methods. Comparative analysis of proteomes from cells grown on gentisate and on glucose revealed that 30% of the proteins of which their abundance changed were involved in aromatic degradation and central carbon metabolism. Similar results were obtained from cells grown on benzoate, 4‐cresol, phenol, and resorcinol. Results from these experiments revealed that (i) enzymes involved in degradation of benzoate, 4‐cresol, gentisate, phenol, and resorcinol were specifically synthesized and (ii) that the abundance of enzymes involved in central carbon metabolism of glycolysis/gluconeogenesis, pentose phosphate pathway, and TCA cycles were significantly changed on various aromatic compounds. Significantly, three novel proteins, NCgl0524, NCgl0525, and NCgl0527, were identified on 4‐cresol. The genes encoding NCgl0525 and NCgl0527 were confirmed to be necessary for assimilation of 4‐cresol with C. glutamicum. The abundance of fructose‐1,6‐bisphosphatase (Fbp) was universally increased on all the tested aromatic compounds. This Fbp gene was disrupted and the mutant WTΔfbp lost the ability to grow on aromatic compounds. Genetic complementation by the Fbp gene restored this ability. We concluded that gluconeogenesis is a necessary process for C. glutamicum growing on various aromatic compounds.
Photochromic crown‐containing molecular switches of chemosensor activity
Authors: Bren Vladimir A. , Dubonosov Alexander D. , Minkin Vladimir I. , Tsukanov Alexey V. , Gribanova Tatyana N. , Shepelenko Evgenii N. , Revinsky Yurii V. , Rybalkin Vladimir P.
Published: September 2007

The crown‐ether functionalized 2‐(N‐acetyl‐N‐arylaminomethylene)benzo[b]thiophene‐3(2H)‐ones exhibit photochromic behavior involving photoinitiated Z/E‐isomerization around the exocyclic CC bond followed by a fast thermal N → O acetyl migration and syn → anti isomerization of the resulting kinetically stable O‐acetyl isomers. The reverse rearrangement is an acid catalyzed reaction. The addition of alkali‐earth metal ions to solutions of N‐acyl isomers induces negligible changes in their UV/Vis spectra, which can be significantly enhanced after irradiation and conversion to the O‐acyl isomers. The compounds obtained may be used as sensitive photodynamic chemosensors with the ‘off‐on’ mechanism for alkali‐earth ions (Ca2+, Ba2+). Quantum‐chemical calculations using the DFT B3LYP/LanL2DZ method predict greater affinity of these sensors to Ca2+ ions (in the gas phase) and to Ba2+ ions (in acetonitrile). Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and thermal crosslinking of oxazolidine‐functionalized polyurethanes
Authors: Andreu Robert , Lligadas Gerard , Carles Ronda Joan , Galià Marina , Cádiz Virginia
Published: September 2007

A new oxazolidine derivative was obtained from phenol, 2‐amino‐2‐methylpropane‐1,3‐diol and paraformaldehyde. The reaction of this novel oxazolidine diol with phenylisocyanate lead to a urethane model compound which can be polymerized thermally by oxazolidine ring opening to give a Mannich bridge structure. Linear segmented polyurethanes were prepared by reaction of different ratios of oxazolidine diol and commercial polyethylenglycol (Mw ∼ 400) with 4,4′‐methylenbis (cyclohexylisocyanate) (HMDI, 90% isomers mixture). The polyurethanes were thermally characterized and crosslinked by oxazolidine ring opening to obtain materials which showed improved thermal stability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4965–4973, 2007
Sphingolipids and the sphingosine kinase inhibitor, SKI II, induce BCL‐2‐independent apoptosis in human prostatic adenocarcinoma cells
Authors: Leroux M.E. , Auzenne E. , Evans R. , Hail N. , Spohn W. , Ghosh S.C. , Farquhar D. , McDonnell T. , Klostergaard J.
Published: September 2007

BACKGROUND

Elevated BCL‐2 is one mechanism of therapeutic resistance in prostate cancer (PC), and new approaches are needed to overcome such resistance.

METHODS

We evaluated the effects of BCL‐2 over‐expression in human prostatic adenocarcinoma cells on their susceptibility to sphingolipids (SLs) and to the sphingosine kinase (SpK) inhibitor, SKI II.

RESULTS

In survival assays, no significant differences were observed in the responses to sphingosine or ceramide among parental PC‐3 cells lacking detectable BCL‐2 and BCL‐2 over‐expressing PC‐3 transfectants; similarly, the responses to dimethyl‐sphingosine (DMSP) of parental LNCaP cells and a BCL‐2 over‐expressing LNCaP transfectant were equivalent. SKI II induced protracted, BCL‐2‐independent survival loss in both PC‐3 and LNCaP parental/transfectant pairs; in contrast, DMSP induced rapid cell shrinkage, caspase activation and caspase‐dependent DNA fragmentation. DMSP‐induced DNA fragmentation and loss of mitochondrial membrane potential were equivalent in BCL‐2 transfectants and parental PC‐3 cells and were not associated with BCL‐2 downregulation. DMSP‐mediated cytotoxicity was not associated with the enhanced production of reactive oxygen intermediates. SL analyses of parental and transfectant PC‐3 cells did not reveal increased levels of sphingosine‐1‐phosphate in the BCL‐2 transfectants; further, there only a modest early shift, corresponding to apoptotic onset, in pro‐ versus anti‐apoptotic SLs in response to DMSP treatment.

CONCLUSIONS

Thus, in contrast to the inhibitory effects of BCL‐2 on apoptosis induced by various agents in tumor cells, SKI II and selected pro‐apoptotic SLs appear atypical in their independence from such inhibition, and may have merits as new candidates for treatment of AI PC. Prostate 67: 1699–1717, 2007. © 2007 Wiley‐Liss, Inc.
Electrospray ionization mass spectrometry of soybean lipoxygenases: N‐terminal acetylation, chemical modification, and solution conformation
Authors: Peariso Amber M. , Nicholson Kellie M. , Benjamin Jones R. , Green‐Church Kari B. , Funk Max O.
Published: September 2007

Electrospray ionization mass spectrometry was used to examine both the covalent structure and solution conformation of the soybean lipoxygenases. The post‐translational modifications of two lipoxgyenases were identified as N‐terminal acetylations by tandem mass spectrometry of peptides generated by trypsin digestion. The N‐terminal sequence suggests that the proteins were substrates for the plant homolog of the N‐terminal acetyltransferase complex C in yeast. Analysis of samples of native lipoxygenase‐3 produced ions corresponding within experimental error to the mass of the N‐acetylated polypeptide and one iron atom. The precision of the measurements was within roughly 100 ppm for the 96,856 Da protein. This made it possible to detect the addition of a single oxygen atom to the enzyme in a chemical modification reaction with cumene hydroperoxide. The acid‐induced denaturation of lipoxygenase‐3, which was accompanied by nearly complete loss of catalytic activity, was observed below pH 3.5 with the appearance of ions in the mass spectrum derived from the apoprotein. There was no evidence for the loss of iron in the absence of unfolding. Solutions of lipoxygenase‐3 incubated in 0.1M acetic acid produced ions with a novel charge state distribution suggesting a unique conformation. Circular dichroism measurements showed that the secondary structure features of the native protein were retained in the new conformation. Dynamic light scattering revealed that the new conformation was not a consequence of protein aggregation as the hydrodynamic radius of lipoxygenase‐3 was significantly smaller in acetic acid solution than at pH 7.0. Remarkably, the enzyme incubated in acetic acid retained full catalytic activity. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Dynamics of group II chaperonin and prefoldin probed by 13C NMR spectroscopy
Authors: Kurimoto Eiji , Nishi Yohei , Yamaguchi Yoshiki , Zako Tamotsu , Iizuka Ryo , Ide Naoki , Yohda Masafumi , Kato Koichi
Published: September 2007

Group II chaperonin (CPN) cooperates with prefoldin (PFD), which forms a jellyfish‐shaped heterohexameric complex with a molecular mass of 87 kDa. PFD captures an unfolded protein with the tentacles and transfers it to the cavity of CPN. Although X‐ray crystal structures of CPN and PFD have been reported, no structural information has been so far available for the terminal regions of the PFD tentacles nor for the C‐terminal segments of CPNs, which were regarded to be functionally significant in the previous studies. Here we report 13C NMR analyses on archaeal PFD, CPN, and their complex, focusing on those structurally uncharacterized regions. The PFD and CPN complexes selectively labeled with 13C at methionyl carbonyl carbons were separately and jointly subjected to NMR measurements. 13C NMR spectral data demonstrated that the N‐terminal segment of the α and β subunits of PFD as well as the C‐terminal segments of the CPN hexadecamer retain significant degrees of freedom in internal motion even in the complex with a molecular mass of 1.1 MDa. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Discrimination of mesophilic and thermophilic proteins using machine learning algorithms
Authors: Gromiha M. Michael , Suresh M. Xavier
Published: September 2007

Discriminating thermophilic proteins from their mesophilic counterparts is a challenging task and it would help to design stable proteins. In this work, we have systematically analyzed the amino acid compositions of 3075 mesophilic and 1609 thermophilic proteins belonging to 9 and 15 families, respectively. We found that the charged residues Lys, Arg, and Glu as well as the hydrophobic residues, Val and Ile have higher occurrence in thermophiles than mesophiles. Further, we have analyzed the performance of different methods, based on Bayes rules, logistic functions, neural networks, support vector machines, decision trees and so forth for discriminating mesophilic and thermophilic proteins. We found that most of the machine learning techniques discriminate these classes of proteins with similar accuracy. The neural network‐based method could discriminate the thermophiles from mesophiles at the five‐fold cross‐validation accuracy of 89% in a dataset of 4684 proteins. Moreover, this method is tested with 325 mesophiles in Xylella fastidosa and 382 thermophiles in Aquifex aeolicus and it could successfully discriminate them with the accuracy of 91%. These accuracy levels are better than other methods in the literature and we suggest that this method could be effectively used to discriminate mesophilic and thermophilic proteins. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Dynamic property is a key determinant for protein–protein interactions
Authors: Bai Hongjun , Ma Wenzhe , Liu Shiyong , Lai Luhua
Published: September 2007

Dynamic property is highly correlated with the biological functions of macromolecules, such as the activity and specificity of enzymes and the allosteric regulation in the signal transduction process. Applications of the dynamic property to protein function researches have been discussed and encouraging progresses have been achieved, for example, in enzyme activity and protein–protein docking studies. However, how the global dynamic property contributes to protein–protein interaction was still unclear. We have studied the dynamic property in protein–protein interactions based on Gaussian Network Model and applied it to classify biological and nonbiological protein–protein complexes in crystal structures. The global motion correlation between residues from the two protomers was found to be remarkably different for biological and nonbiological complexes. This correlation has been used to discriminate biological and nonbiological complexes in crystal and gave a classification rate of 86.9% in the cross‐validation test. The innovation of this feature is that it is a global dynamic property which does not rely directly on the interfacial properties of the complex. In addition, the correlation of the global motions was found to be weakly correlated with the dissociation rate constant of protein complexes. We suggest that the dynamic property is a key determinant for protein–protein interaction, which can be used to discriminate native and crystal complexes and potentially be applied in protein–protein dynamic rate constants estimations. Proteins 2008. © 2007 Wiley‐Liss, Inc.
ClusPro: Performance in CAPRI rounds 6–11 and the new server
Authors: Comeau Stephen R. , Kozakov Dima , Brenke Ryan , Shen Yang , Beglov Dmitri , Vajda Sandor
Published: September 2007

ClusPro is the first fully automated, web‐based program for docking protein structures. Users may upload the coordinate files of two protein structures through ClusPro's web interface, or enter the PDB codes of the respective structures. The server performs rigid body docking, energy screening, and clustering to produce models. The program output is a short list of putative complexes ranked according to their clustering properties. ClusPro has been participating in CAPRI since January 2003, submitting predictions within 24 h after a target becomes available. In Rounds 6–11, ClusPro generated acceptable submissions for Targets 22, 25, and 27. In general, acceptable models were obtained for the relatively easy targets without substantial conformational changes upon binding. We also describe the new version of ClusPro that incorporates our recently developed docking program PIPER. PIPER is based on the fast Fourier transform correlation approach, but the method is extended to use pairwise interaction potentials, thereby increasing the number of near‐native docked structures. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Prediction and scoring of docking poses with pyDock
Authors: Grosdidier Solène , Pons Carles , Solernou Albert , Fernández‐Recio Juan
Published: September 2007

The two previous CAPRI experiments showed the success of our rigid‐body and refinement approach. For this third edition of CAPRI, we have used a new faster protocol called pyDock, which uses electrostatics and desolvation energy to score docking poses generated with FFT‐based algorithms. In target T24 (unbound/model), our best prediction had the highest value of fraction of native contacts (40%) among all participants, although it was not considered as acceptable by the CAPRI criteria. In target T25 (unbound/bound), we submitted a model with medium quality. In target T26 (unbound/unbound), we did not submit any acceptable model (but we would have submitted acceptable predictions if we had included available mutational information about the binding site). For targets T27 (unbound/unbound) and T28 (homo‐dimer using model), nobody (including us) submitted any acceptable model. Intriguingly, the crystal structure of target T27 shows an alternative interface that correlates with available biological data (we would have submitted acceptable predictions if we had included this). We also participated in all targets of the SCORERS experiment, with at least acceptable accuracy in all valid cases. We submitted two medium and four acceptable scoring models of T25. Using additional distance restraints (from mutational data), we had two medium and two acceptable scoring models of T26. For target T27, we submitted two acceptable scoring models of the alternative interface in the crystal structure. In summary, CAPRI showed the excellent capabilities of pyDock in identifying near‐native docking poses. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Toxicity of dimethoate and fenoxycarb to honey bee brood (Apis mellifera), using a new in vitro standardized feeding method
Authors: Aupinel Pierrick , Fortini Dominique , Michaud Bruno , Marolleau Franck , Tasei Jean‐Noël , Odoux Jean‐François
Published: September 2007

A new in vitro method was devised to assess the effects of pesticides on honey bee brood. The method allowed the quantification of doses ingested by larvae and the assessment of larval and pupal mortality. Larval mortality in control samples was lower than 10%. Two active substances were tested: dimethoate and fenoxycarb. The LD50 of dimethoate was 1.9 µg larva−1 48 h after oral exposure of larvae at day 4. Additional dose‐related effects on pupal mortality were noted. After a chronic intoxication, the NOAEC (No Observed Adverse Effect Concentration) for larval mortality at day 7 was 2.5 mg kg−1, whereas a NOAEC of 5 mg kg−1 was found at day 22 for delayed effects on the reduction of adult emergence. Fenoxycarb applied at day 4 showed no effect on larvae, whereas emergence of adults was affected at doses higher than 6 ng larva−1. Copyright © 2007 Society of Chemical Industry
The relevance of sublethal effects in honey bee testing for pesticide risk assessment
Authors: Thompson Helen M , Maus Christian
Published: September 2007

The option of an evaluation and assessment of possible sublethal effects of pesticides on bees has been a subject of discussion by scientists and regulatory authorities. Effects considered included learning behaviour and orientation capacity. This discussion was enhanced by the French bee issue and allegations against systemic insecticides that were linked to the hypothesis that sublethal intoxication might even have led to reported colony losses. This paper considers whether and, if so, how sublethal effects should be incorporated into risk assessment, by addressing a number of questions: What is meant by a sublethal effect? Which sublethal effects should be measured, when and how? How are sublethal effects to be included in risk assessments? The authors conclude that sublethal studies may be helpful as an optional test to address particular, compound‐specific concerns, as a lower‐tier alternative to semi‐field or field testing, if the effects are shown to be ecologically relevant. However, available higher‐tier data (semi‐field, field tests) should make any additional sublethal testing unnecessary, and higher‐tier data should always override data of lower‐tier trials on sublethal effects. © Crown copyright 2007. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Ab initio electronic band structure calculations of half‐metallic c alcium pnictides
Authors: Jaiganesh G. , Eithiraj R. D. , Kalpana G. , Rajagopalan M.
Published: September 2007

Ab initio electronic structure calculations of hypothetical zinc‐blende CaX (X = P, As, Sb) were performed using tight‐binding linear muffin‐tin orbital method. It was found that, these compounds are ferromagnets exhibiting half‐metallicity. Total energy calculations show that the zinc blende ferromagnetic phase is more stable than the zinc‐blende non‐magnetic phase at equilibrium volume. Ground state properties such as equilibrium lattice constant, bulk modulus and cohesive energy were calculated. The calculated magnetic moment is found to be 1μB per formula unit for all these materials, which agrees well with the other theoretical results. On reducing the cell volume all these compounds are found to undergo a magnetic phase transition from zinc‐blende ferromagnetic phase to zinc‐blende non‐magnetic phase. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dispersion‐related theory for heat capacities of semiconductors
Authors: Pässler Roland
Published: September 2007

A reasonable analytical basis for dispersion‐related descriptions of the temperature dependences of harmonic parts of isochoric heat capacities is given by a three‐oscillator model for phonon density of states (PDOS) spectra of semiconductors with a relatively large degree of phonon dispersion. Within this model, a combination of two lower‐energy oscillators substitutes the lower (acoustical) part, and a single higher‐energy oscillator represents the upper (optical) part of PDOS spectra. This model provides good simulations of T ‐dependences of harmonic parts of isochoric heat capacities from moderately low to high temperatures. The incorporation of continuous (quadratic and quartic) power function components into the low‐energy tail region enables a very fine description of temperature dependences also throughout the cryogenic region. Deviations of experimentally measured heat capacities from their harmonic parts are quantified by a conveniently designed low‐order anharmonicity term. The corresponding analytical model provides excellent numerical simulations of isobaric heat capacities of Si and Ge from absolute zero up to room temperature on the basis of least‐mean‐square fittings involving total sets of 6 model‐specific parameters in combination with known zero temperature values of Debye temperatures. As important by‐products of these fittings we obtain adequate values for the material‐specific PDOS spectra moments for all orders within the range –3 < n ≤ 10. The extended version of this dispersion‐related description, which involves a power series expansion for anharmonic components of heat capacities, represents an unprecedented analytical tool for adequate numerical representations of isobaric heat capacities of Si and Ge throughout the whole experimentally relevant temperature region, i.e. from absolute zero up to the respective melting points.

Supporting information for this acticle (Appendices on “Self‐sufficient scheme for estimations of even moments” and “Direct use of heat capacity data for determinations of lower moments”) is provided online at www.pss‐b.com.

(© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)