bluuebunny/crossref_metadata_2025 huggingface dataset:
Binding and elution strategy for improved performance of arginine affinity chromatography in supercoiled plasmid DNA purification
Authors: Sousa F. , Prazeres D. M. F. , Queiroz J. A.
Published: September 2008

New interesting strategies for plasmid DNA (pDNA) purification were designed, exploiting affinity interactions between amino acids and nucleic acids. The potential application of arginine‐based chromatography to purify pDNA has been recently described in our work; however, to achieve higher efficiency and selectivity in arginine affinity chromatography, it is essential to characterize the behaviour of binding/elution of supercoiled (sc) isoforms. In this study, two different strategies based on increased sodium chloride (225–250 mm) or arginine (20–70 mm) stepwise gradients are described to purify sc isoforms. Thus, it was proved that well‐defined binding/elution conditions are crucial to enhance the purification performance, resulting in an improvement of the final plasmids yields and transfection efficiency, as this could represent a significant impact on therapeutic applications of the purified sc isoform. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of the Optimal Conditions for Synthesis of Silver Oxalate Nanorods
Authors: Pourmortazavi S. M. , Hajimirsadeghi S. S. , Kohsari I. , Fareghi Alamdari R. , Rahimi‐Nasrabadi M.
Published: September 2008

In this study, an orthogonal array design (OAD), OA9, was employed as a statistical experimental method for the controllable, simple and fast synthesis of silver oxalate nanorods. Ultrafine silver oxalate rods were synthesized by a precipitation method involving the addition of silver ion solution to the oxalate reagent. The effects of reaction conditions, i.e., silver and oxalate concentrations, flow rate of reagent addition and temperature, on the diameter of the synthesized silver oxalate rods were investigated. The effects of these factors on the width of the silver oxalate rods were quantitatively evaluated by the analysis of variance (ANOVA). The results showed that silver oxalate nanorods can be synthesized by controlling the silver concentration, flow rate and temperature. Finally, the optimum conditions for the synthesis of silver oxalate nanorods by this simple and fast method were proposed. The results of ANOVA showed that 0.001 mol/L silver ion concentration, 40 mL/min flow rate for the addition of the silver reagent to the oxalate solution and 0 °C temperature are the optimum conditions for producing silver oxalate nanorods with 107 ± 45 nm width.
Modeling of Soot and Polycyclic Aromatic Hydrocarbons in Diesel Diffusion Combustion
Authors: Song Y.‐N. , Zhong B.‐J.
Published: September 2008

By integrating a reduced n‐heptane oxidation chemical kinetic reaction mechanism in a multidimensional computational fluid dynamic solver, simulation of the turbulent diffusion reactive flow inside the direct injection (DI) diesel combustor through compression and expansion stroke were implemented. Coupled with the soot kinetic model by the method of moments, the soot formation is modeled simultaneously with a gas‐phase flame. Under fuel lean flame, orders of magnitude of the multi‐ring polycyclic aromatic hydrocarbon (PAH) intermediate molar fraction are very small. Though soot surface growth is overwhelmed quickly by oxidation under current modeling conditions, the simulated soot number density and average diameter curves are consistent with experimental results. A detailed soot kinetic mechanism is a prospect for further research in computational fluid dynamics (CFD) modeling.
Phase 1 trial of lipoplatin and gemcitabine as a second‐line chemotherapy in patients with nonsmall cell lung carcinoma
Authors: Froudarakis Marios E. , Pataka Athanasia , Pappas Periklis , Anevlavis Stavros , Argiana Evangelia , Nikolaidou Martha , Kouliatis George , Pozova Sofia , Marselos Marios , Bouros Demosthenes
Published: September 2008

BACKGROUND.

Lipoplatin is a new liposomal cisplatin that already has been tested in solid tumors, with encouraging results. The purpose of the current study was to determine the maximum tolerated dose (MTD) and the dose‐limiting toxicity (DLT) of a 21‒day regimen of lipoplatin plus a fixed dose of gemcitabine in patients with refractory or resistant nonsmall cell lung carcinoma (NSCLC) with an Eastern Cooperative Oncology Group (ECOG) performance status of ≤2.

METHODS.

The lipoplatin dose was escalated at 100 mg/m2 by increments of 10 mg/m2 on Days 1 and 8, with gemcitabine at a dose of 1000 mg/m2 administered on Days 1 and 8, repeated every 21 days. Hematopoietic growth factors were not allowed. Thirteen patients with advanced stage NSCLC who had been pretreated with platinum combination chemotherapy were enrolled in this phase 1 trial. At least 3 patients were entered at each dose level.

RESULTS.

At the fourth dose level, the DLT was reached (grade 3 neutropenia [according to World Health Organization criteria] in 3 of 4 patients 75%]; the fourth patient demonstrated degradation of performance status). Therefore, the third dose level (lipoplatin at a dose of 120 mg/m2) was defined as the MTD. At the same dose level, 2 of 4 patients had grade 3 thrombocytopenia. At the fourth dose level, 1 patient achieved a partial response and 1 patient had stable disease. Another patient achieved stable disease at the second dose level. Therefore, the overall disease control rate was 23% (3 of 13 patients). The median overall survival was 29 weeks (range, 4 weeks‐59 weeks) and the median time to disease progression was 12 weeks (range, 3 weeks‐36 weeks).

CONCLUSIONS.

The pharmacokinetic profile of the 2 compounds used in the current study are not modified when they are administered according to the schedule evaluated in this trial. When one considers that the patients in the current study had refractory or resistant NSCLC, the authors concluded that the combination of lipoplatin administered at a dose of 120 mg/m2 and gemcitabine administered at a dose of 1000 mg/m2 on Days 1 and 8 every 3 weeks needs to be studied further in phase 2 trials. Cancer 2008. © 2008 American Cancer Society.
NMR Spectroscopic Studies of Interactions in Solution during the Synthesis of MoVTeNb Oxide Catalysts
Authors: Maksimovskaya Raisa I. , Bondareva Valentina M. , Aleshina Galina I.
Published: September 2008

Aqueous solutions used for the synthesis of MoVTeNb oxide catalysts have been studied with 125Te, 95Mo, 51V, and 17O NMR spectroscopy. Polyoxometalate (POM) anion V9TeO285– (I), which has the decavanadate structure, containing Te6+ in one of its two central positions, has been identified for the first time in VV‐TeVI solutions. In ternary MoVI‐VV‐TeVI solutions, the POMs TeMo6O246– (II) (pH ca. 7.8–2) as well as previously unknown complexes of the proposed compositions TeV3Mo3O249– (III) (pH ca. 8–5) and TeMo3V5O275– (IV) (pH ca. 6–1) were observed. In the structure of IV, half of the decavanadate anion is combined with half of the octamolybdate anion, in which the central Mo atom is replaced with Te6+. There is an equilibrium, IV [rlarr2] I + II, in the ternary solutions. Despite its stability in solution, polyanion IV could not be isolated in the solid state. During concentration under ambient conditions, less soluble polyanion II begins to crystallize first, and the equilibrium in solution gradually shifts to I. Upon dissolving the precipitate, complex IV forms again. The distribution diagrams have been derived from the NMR spectra for a solution of the cationic composition Mo1V0.3Te0.23 with NH4+ as a counterion, acidified with HClO4 in the pH range 7.25–1. In addition to the above‐mentioned complexes, VO2+ and MoO22+ oxalates form in the presence of oxalic acid. Upon adding niobium oxalate, Nb2O5 gel forms without any Nb‐containing species in solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Heterometallic Transition‐Metal Complexes Based on 1‐Carboxy‐1′‐(diphenylphosphanyl)ferrocene, (tmeda/pmdta)Zinc(II), and Gold(I) Units
Authors: Kühnert Janett , Ecorchard Petra , Lang Heinrich
Published: September 2008

The synthesis of the ZnII and TiIV carboxylates [LnM(O2CfcPPh2)2] {LnM = (tmeda)Zn (3); LnM = (pmdta)Zn (8); LnM = [Ti] (12); fc = (η5‐C5H4)2Fe; tmeda = N,N,N′,N′‐tetramethylethylenediamine; pmdta = 1,1,4,7,7‐pentamethyldiethylentriamine; [Ti] = (η5‐C5H5)2Ti} and [LnM(X)(O2CfcPPh2)] {LnM = (pmdta)Zn, X = Cl (7); LnM = [Ti], X = Me (10)} is reported. The reaction of Hdpf (1) {Hdpf = (η5‐C5H4CO2H)(η5‐C5H4PPh2)Fe} with [(tht)AuCl] (13) (tht = tetrahydrothiophene) gave [(Hdpf)AuCl] (14). Treatment of 3, 7, and 10 with 13 produced trimetallic [LnM(X){(O2CfcPPh2)AuCl}] {LnM = [Ti], X = Me (15); LnM = (pmdta)Zn, X = Cl (16)} or [(tmeda)Zn{(O2CfcPPh2)AuCl}2] (17). Heptametallic complexes were accessible by the reaction of 14 with HC≡CR {R = Fc, Rc; Fc = (η5‐C5H4)(η5‐C5H5)Fe; Rc = (η5‐C5H4)(η5‐C5H5)Ru}, whereby [(H2NEt2){(O2CfcPPh2)AuCl}] (18) and [(H2NEt2){(O2CfcPPh2)AuC≡CR}] {R = Fc (20a), Rc (20b)} were formed. Further reaction of 20a and 20b with [(tmeda)ZnCl2] (2) gave [(tmeda)Zn{(O2CfcPPh2)AuC≡CR}2] {R = Fc (21a), Rc (21b)}. The solid‐state structures of 3, 7, 12, and 18 were determined by single‐crystal X‐ray diffraction. The Zn atom in 3 is in a distorted tetrahedral environment, while in 7 it is part of a distorted bipyramidal arrangement. In 18, a stairlike 1D chain is built from three independent molecules of 18 by N–H···O hydrogen bonds and π–π interactions between phenyl or cyclopentadienyl rings of adjacent molecules. The cyclovoltammetric properties of 3, 7, 14, 16, 17, 18, 21a, and 21b are reported.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis and Structure of Zirconium and Hafnium Polymerisation Catalysts Stabilised by Very Bulky Aminopyridinato Ligands
Authors: Noor Awal , Kretschmer Winfried P. , Glatz Germund , Meetsma Auke , Kempe Rhett
Published: September 2008

Mono(aminopyridinato) complexes of the type [ApM(CH2C6H5)3] [M = Zr, Hf and Ap = aminopyridinate] were prepared by treating the three different sterically demanding aminopyridines with one equiv. of tetrabenzylzirconium or ‐hafnium. One of the three benzyl groups is η2‐coordinated in the solid state. However all of the three benzyl substituents are equivalent in solution as evidenced by the 1H NMR spectrum. Treatment of these neutral complexes with B(C6F5)3 afforded the corresponding zwitterionic dibenzyl complexes. The η6‐coordination of the phenyl ring of the B‐bound benzyl group to the metal centre was supported by 1H NMR spectroscopy and confirmed by single‐crystal X‐ray diffraction analysis. These zwitterionic complexes show very low activity for ethylene polymerisation at low temperature since the coordination site is blocked by the η6‐coordinated phenyl ring. At elevated temperature, moderate activity with the formation of high molecular weight polyethylene (PE) was observed. An attempted abstraction of the second benzyl group failed when the zwitterionic complexes were treated with an additional equivalent of B(C6F5)3. Using one equiv. of [R2(Me)NH][B(C6F5)4] (R = C16H33–C18H37) instead of B(C6F5)3, moderate activities of ethylene polymerisation were observed. Treatment of the aminopyridinato metal tribenzyls with [R2(Me)NH][B(C6F5)4] (R = C16H33–C18H37) gave active ethylene polymerisation catalysts which produced low molecular weight PE in the case of the zirconium analogues and higher molecular weight PE in the case of the hafnium example. Propylene homopolymerisation under the same conditions failed. Ethylene–propylene copolymers with separated propene units and alternating sequences were observed in the presence of both monomers.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Denial of Tris(C,N‐cyclometalated) Ruthenacycle: Nine‐Membered η6‐N,N‐trans or η2‐N,N‐cis RuII Chelates of 2,2′‐Bis(2‐pyridinyl)‐1,1′‐biphenyl
Authors: Saavedra‐Díaz Omar , Cerón‐Camacho Ricardo , Hernández Simon , Ryabov Alexander D. , Le Lagadec Ronan
Published: September 2008

In the attempt to prepare the tris(cyclometalated) ruthenium derivative of 2‐phenylpyridine, [Ru(η6‐C6H6)(phpy)Cl] was treated with Hg(phpy)2. The anticipated [Ru(phpy)3]n+ species was not formed. Instead, the product of oxidative coupling of two 2‐(2‐pyridinyl)phenyl ligands to form octahedral [RuII(phpy)(pbp)]PF6 with pbp = 2,2′‐bis(2‐pyridinyl)‐1,1′‐biphenyl was isolated; pbp forms a nine‐membered chelate with two N and two η2‐C=C donor centers. The binding of η2‐C=C donor units is weak as they are readily replaced by CO. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Stable Trichlorosilane–Pyridine Adducts
Authors: Fester Gerrit W. , Wagler Jörg , Brendler Erica , Kroke Edwin
Published: September 2008

The prepapration, and first comprehensive spectroscopic and structural characterization of octahedral trichlorosilane adducts HSiCl3(Rpy)2 with R = H, 4‐CH3, 4‐C6H5, 3‐Br, 4‐CHCH2, 4‐C2H5, 4‐C(CH3)3 and 4‐N(CH3)2 is reported. The products are surprisingly stable in the solid state and easily obtained in high yield. Single‐crystal X‐ray diffraction analysis of HSiCl3(3‐Brpy)2 revealed relatively short Si–Cl bonds (218–223 pm) while the Si–N bonds (ca. 198 pm) are only slightly longer than in the corresponding H2SiCl2(Rpy)2adducts. Dismutation reactions were observed only in polar solvents at elevated temperatures.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Oxime‐Based Synthesis of New Chromogenic and Fluorogenic Oligosaccharides
Authors: Renaudet Olivier , Dumy Pascal
Published: September 2008

A new simple approach for the synthesis of labelled oligosaccharides is described. Free synthetic carbohydrate recognition building blocks were conjugated with fluorogenic and chromogenic dyes under mild experimental conditions by using oxime ligation. The resulting oligosaccharide probes presenting well‐defined anomer configuration might find broad interests for recognition studies with a large panel of carbohydrate‐binding proteins. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Evaluation of Meldola Blue‐Carbon Nanotube‐Sol‐Gel Composite for Electrochemical NADH Sensors and Their Application for Lactate Dehydrogenase‐Based Biosensors
Authors: Arvinte Adina , Sesay Adama M. , Virtanen Vesa , Bala Camelia
Published: September 2008

A novel MB‐SWNT‐sol‐gel nanocomposite material was prepared by the sol‐gel process incorporating a redox mediator and carbon nanotubes. The electrocatalytic properties of the nanomaterial based sensor toward NADH oxidation were studied by electrochemical measurements. Significant enhancement of oxidation current is obtained at electrodes modified by MB‐SWNT‐sol‐gel in comparison with the analogous carbon black and/or graphite composite modified electrode. The usefulness of the nanocomposite material as a matrix for immobilizing enzymes is also demonstrated. Analytical parameters of D‐lactate biosensors with and without SWNT in the hybrid film were compared demonstrating that performance of the biosensor was significantly improved when introducing SWNT.
Contribution of roots and hyphae to phosphorus uptake of mycorrhizal onion (Allium cepa L.)—A mechanistic modeling approach
Authors: Gashaw Deressa Tesfaye , Schenk Manfred K.
Published: September 2008

Phosphorus uptake by plant roots and arbuscular mycorrhizae (AM) hyphae can be described based on morphological and physiological uptake characteristics and parameters affecting P transport in the soil to the uptake surface. The current study aimed to quantify the relative contribution of hyphae and roots to P uptake of onion and to investigate the associated mechanisms using a mechanistic simulation model. Onion was grown in a growth chamber under controlled conditions at five levels of P supply with (M) or without (NM) AM. Uptake by onion roots and AM hyphae was simulated separately using a nutrient‐uptake model, which was developed for roots. Model parameters describing P transport in the soil, as well as morphological and physiological uptake characteristics of roots and hyphae were derived from soil and nutrient‐solution experiments. The model fairly described P uptake of M and NM plants at the highest level of P supply (28 µM P in soil solution) where roots and hyphae contributed nearly equally to P uptake of M plants. However, at lower P levels (≤0.41 µM P), hyphae accounted for nearly the whole P uptake whereas roots hardly explained any uptake. The effectiveness of AM hyphae at low P supply was well explained by their favorable morphological and physiological uptake properties. Hyphae were characterized by a diameter of 3 × 10–4 cm, a Km of 0.25 µM, and a Cmin of 0.04 µM, values that are about 200, 40, and 10 times lower, respectively, compared to those of roots. Not more than 60% of the uptake at lower levels of P supply could be explained by the sum of predicted uptake of roots and hyphae suggesting that hyphae and roots may have used mechanisms additional to those described by the model to mobilize P. This work demonstrated that mechanistic models can be useful tools to study the role of AM in P uptake of plants, although reliable estimation of model parameters, especially physiological uptake properties of AM, is still limiting this approach.
Impact of the heatwave in 2003 on the summer CH4 budget of a spruce forest with large variation in soil drainage: A four‐year comparison (2001–2004)
Authors: Fiedler Sabine , Lamers Marc , Ingwersen Joachim , Streck Thilo , Stahr Karl , Jungkunst Hermann F.
Published: September 2008

Well‐aerated soils are sinks for atmospheric methane (CH4) whereas hydromorphic soils act as sources. Both CH4 oxidation and production are highly sensitive to variation in soil moisture. Significant changes of net CH4 fluxes from soils can therefore be expected to accompany redistribution of precipitation in the course of climate change where more extreme events are predicted for the future. The extreme summer drought in 2003 offered the opportunity to study the impact of such events on methane fluxes under field conditions. The objective was to evaluate the impact of the summer drought in 2003 on net methane budget of a spruce‐forest ecosystem. We studied net CH4 flux (bi‐)weekly during the summers of 2000–2004 using a closed‐chamber technique on six different soil types ranging from well‐aerated Cambisols, to poorly drained Gleysols and a wet Histosol in a cool‐humid spruce forest.
Unprecedented Route to Ordered Polyaniline: Direct Synthesis of Highly Crystalline Fibrillar Films with Strong π‐π Stacking Alignment
Authors: Gospodinova Natalia , Ivanov Dimitri A. , Anokhin Denis V. , Mihai Iulia , Vidal Loïc , Brun Sulyvan , Romanova Julia , Tadjer Alia
Published: September 2008

Films of polyaniline (PANI) featuring about 80% crystallinity and characterised with strong π‐π stacking alignment parallel to the film surface have been obtained directly after the original synthesis upon simple drying of the aqueous PANI suspension. A strong anisotropy in the growth of the nano‐sized crystals produced during the synthesis results in the formation of micrometer‐length fibrils perpendicular to the film surface in the course of water evaporation. The regular intercalation of water molecules between the PANI chains seems to be crucial for their ordering throughout the synthesis and film formation.

magnified image
DFT–GIAO–NBO and 13C NMR study of the δ‐syn‐axial effect in 2,4‐disubstituted adamantanes
Authors: Mikhova B. , Stamboliyska B. , Koch A. , Duddeck H. , Kleinpeter E.
Published: September 2008

Six groups of diastereomeric 2,4‐disubstituted adamantanes were studied with DFT–GIAO–NBO (natural orbital analysis) methods. The calculated 13C chemical shifts reproduce well the experimental data. It was found that among all diastereomers, those bearing substituents in δ‐syn‐axial positions showed the largest overall deshielding, i.e. the sum of all 13C chemical shifts [Σδ(13C)] was the greatest and also had the highest delocalization contribution to the molecular energy evaluated with NBO. The higher delocalization energy is proposed to be the origin of the deshielding δ‐syn‐axial effect. Copyright © 2008 John Wiley & Sons, Ltd.
Complete assignments of 1H and 13C NMR spectral data for three sesquiterpenoids from Inula helenium
Authors: Huo Yan , Shi Haiming , Wang Mengyue , Li Xiaobo
Published: September 2008

The complete assignments of all the 1H and 13C NMR signals of three sesquiterpene lactones, 4‐oxo‐5(6),11‐eudesmadiene‐8,12‐olide (1), 4‐oxo‐11‐eudesmaene‐8,12‐olide (2) and (1(10)E)‐5β‐Hydroxygermacra‐1(10),4(15),11‐trien‐8, 12‐olide (3), were carried out by various 2D NMR experiments. Compounds 1–3 were isolated from the roots of Inula helenium for the first time. Among them, 1 was identified as a new nor‐sesquiterpene lactone, and 2 was isolated from a natural source for the first time. The 13C‐NMR data of compound 3 was also reported for the first time. Copyright © 2008 John Wiley & Sons, Ltd.
Hospitalist educators: future of inpatient internal medicine training
Authors: Goldenberg Jill , Glasheen Jeffrey J.
Published: September 2008

Academic hospitalists have grown in number and influence over the past decade. This has fueled concerns about the effect of hospitalists on resident and student education. While the bulk of the literature favors the hospitalist teaching model to a more traditional model concerns remain that hospitalists may negatively imipact housestaff autonomy and reduce exposure to subspeciality physicians. This paper will review the literature exploring the effect of the hospitalist teaching model on resident and student education. Mt Sinai J Med 75: 430–435, 2008. © 2008 Mount Sinai School of Medicine
Achieving hospital medicine's promise through internal medicine residency redesign
Authors: Glasheen Jeffrey J. , Goldenberg Jill , Nelson John R.
Published: September 2008

The promise of the hospital medicine movement is that the hospitalist model of care will provide better outcomes than the system it replaced. This means improving the quality and processes of care, reducing inefficiencies and lowering costs. Despite some documented improvements in these areas hospitalists have yet to achieve their pinnacle. These shortfalls likely result from training providers in residencies that have yet to evolve to address the specific needs of hospitalists. While most internal medicine residency training programs stress inpatient care they underemphasize key components of a successful hospitalist career. This paper overviews the state of the hospitalist movement, the current educational training deficiencies and the methods to deliver hospitalist‐focused training. Mt Sinai J Med 75: 436–441, 2008. © 2008 Mount Sinai School of Medicine
Preparation and mechanical properties of well‐aligned and well‐oriented poly(vinyl alcohol) nanoribbon
Authors: Iwashita Mai , Kotera Masaru , Nishino Takashi
Published: September 2008

We report a novel, economical method of preparing well‐aligned and well‐oriented nanoribbons made of poly(vinyl alcohol) (PVA). The method requires no special equipment and easily produces nanoribbon. The structure of uniaxially drawn nanoribbon was investigated by polarized microscopy, polarized FT‐IR, and X‐ray diffraction, which showed high molecular and crystallite orientations. The well‐aligned PVA nanoribbon, measuring several tens of micrometer width and around 400 nm thickness, had a Young's modulus of 9 GPa and a tensile strength of 350 MPa. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and characteristic of polybenzoxazine with phenylnitrile functional group
Authors: Qi Huimin , Ren Hao , Pan Guangyan , Zhuang Yuanqi , Huang Farong , Du Lei
Published: September 2008

The phenylnitrile functional benzoxazine monomers, 3‐phenyl‐3,4‐dihydro‐ 6‐nitril‐2H‐1,3‐benzoxazine (NBen‐a) and 4,4′‐bis(3,4‐dihydro‐6‐nitril‐2H‐1,3‐benzoxazine‐3‐yl)phenylether (NBen‐De), were synthesized and characterized by Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (1H‐NMR). The curing behaviors of NBen‐a and NBen‐De were characterized by differential scanning calorimetry (DSC) and FTIR. Thermal stability and dynamic mechanical properties of the cured NBen‐a and NBen‐De were investigated using thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The cured NBen‐a and NBen‐De showed glass transition temperature (Tg), the thermal stability improved as compared to the analogous polybenzoxazine without phenylnitrile group. Copyright © 2008 John Wiley & Sons, Ltd.
Active drug safety surveillance: a tool to improve public health
Authors: Platt Richard , Madre Leanne , Reynolds Robert , Tilson Hugh
Published: September 2008

Purpose

Ensuring that drugs have an acceptable safety profile and are used safely is a major public health priority. The Centers for Education and Research on Therapeutics (CERTs) convened experts from academia, government, and industry to assess strategies to increase the speed and predictive value of generating and evaluating safety signals, and to identify next steps to improve the US system for identifying and evaluating potential safety signals.

Methods

The CERTs convened a think tank comprising representatives of the groups noted above to address these goals.

Results

Participants observed that, with the increasing availability of electronic health data, opportunities have emerged to more accurately characterize and confirm potential safety issues. The gain for public health from a highly coordinated network of population‐based databases for active surveillance is great and within reach, although operational questions remain. A collaborative network must create a working definition of a safety signal, screening algorithms, and criteria and strategies to confirm or refute a signal once identified through screening. Guidelines are needed for when and how to communicate a signal exists and is being evaluated, as well as the outcome of that evaluation.

Conclusion

A public–private partnership to create a network of government and private databases to routinely evaluate and prioritize safety questions is in the public interest. Better methods are needed, and a knowledgeable workforce is required to conduct the surveillance and understand how to interpret the results. The international community will benefit from the availability of better methods and more experts. Copyright © 2008 John Wiley & Sons, Ltd.
Comparison of the folding mechanism of highly homologous proteins in the lipid‐binding protein family
Authors: Ropson Ira J. , Boyer Joshua A. , Schaeffer Blake A. , Dalessio Paula M.
Published: September 2008

The folding mechanism of two closely related proteins in the intracellular lipid‐binding protein family, human bile acid‐binding protein (hBABP), and rat bile acid‐binding protein (rBABP) were examined. These proteins are 77% identical (93% similar) in sequence. Both of these single domain proteins fit well to a two‐state model for unfolding by fluorescence and circular dichroism at equilibrium. Three phases were observed during the unfolding of rBABP by fluorescence but only one phase was observed during the unfolding of hBABP, suggesting that at least two kinetic intermediates accumulate during the unfolding of rBABP that are not observed during the unfolding of hBABP. Fluorine NMR was used to examine the equilibrium unfolding behavior of the W49 side chain in 6‐fluorotryptophan‐labeled rBABP and hBABP. The structure of rBABP appears to be more dynamic than that of hBABP in the vicinity of W49 in the absence of denaturant, and urea has a greater effect on this dynamic behavior for rBABP than for hBABP. As such, the folding behavior of highly sequence related proteins in this family can be quite different. These differences imply that moderately sized proteins with high sequence and structural similarity can still populate quite different structures during folding. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Applying undertaker cost functions to model quality assessment
Authors: Archie John , Karplus Kevin
Published: September 2008

Undertaker is a program designed to help predict protein structure using alignments to proteins of known structure and fragment assembly. The program generates conformations and uses cost functions to select the best structures from among the generated conformations. This paper describes the use of Undertaker's cost functions for model quality assessment. We achieve an accuracy that is similar to other methods, without using consensus‐based techniques. Adding consensus‐based features further improves our approach substantially. We report several correlation measures, including a new weighted version of Kendall's τ (τ3) and show model quality assessment results superior to previously published results on all correlation measures when using only models with no missing atoms. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Entangled‐photon generation from a quantum dot in cavity QED
Authors: Ajiki Hiroshi , Ishihara Hajime
Published: September 2008

We theoretically study polarization‐entangled photon generation from a single quantum dot in a microcavity. Entangled‐photon pairs with singlet or triplet Bell states are generated in the resonant‐hyperparametric scattering via dressed states in the cavity QED.

Although co‐polarized non‐entangled photons are also generated, the generation is dramatically suppressed in the strong‐coupling limit owing to the photon blockade effect. Finite binding energy of biexciton is also important for the generation of photon pairs with high degree of entanglement. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rapid energy transfer and ist temperature dependence in π ‐conjugated dendrimers
Authors: Akai I. , Miyanari K. , Shimamoto T. , Fujii A. , Nakao H. , Okada A. , Kanemoto K. , Karasawa T. , Ishida A. , Yamada A. , Katayama I. , Takeda J. , Kimura M.
Published: September 2008

We investigate a rapid energy transfer (ET) process and its temperature dependence in a star‐shaped stilbenoid phthalocyanine (SSS1Pc) dendrimer having π ‐conjugated light‐harvesting (LH) antennas. In SSS1Pc, intense core‐photoluminescence is observed under selective excitation on the LH‐antenna as a result of the highly efficient ET from the LH‐antenna. Pump‐probe experiments show that ET occurs rapidly with a rising time constant (∼ 250 fs).

To understand such rapid ET, we employ a simplified ET model through a π ‐conjugated network between the Lhantenna and the core that takes into account the steric hindrance between the LH‐antenna subunits. Our model reveals that the highly efficient ET at room temperature in SSS1Pc takes place through the π ‐conjugated network mediated by a thermally activated torsional vibration of the aromatic ring subgroup in the LH‐antenna. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Up to 30 times enhancement of deep UV emission at room temperature by prolonged excitation of localized exciton in NaCl:I crystal
Authors: Akimoto Ikuko , Shimozato Masahiro , Kan'no Ken‐ichi
Published: September 2008

A material emitting DUV light at room temperature is promising for an application to a new laser action. We report the remarkable phenomena that deep ultra‐violet (DUV) emission at 220 nm, so‐called NE emission, in NaCl:I crystal is enhanced up to 30 times at room temperature by prolonged excitation of the localized exciton. Such an accumulated effect is kept even if the excitation is interuped for a few minutes but is completely reset by white light irradiation at room temperature. The phenomena are discussed considering thermal ionization of iodine anion by the VUV light excitation, trapping of dissociated electrons in hole centers and recombination of electrons and iodine hole centers. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of anthracene‐fluorene mixed crystals fabricated by cell method
Authors: Aoki‐Matsumoto Tamao , Takama Atsushi , Mizuno Ken‐ichi , Hirai Takeshi , Matsumura Michio
Published: September 2008

Anthracene‐fluorene mixed crystals with anthracene mole fraction of 0.1 to 100% are fabricated using a cell method and their optical properties are studied. In contrast to sharp luminescence due to isolated anthracene molecules in a 0.1% doped sample and in a pure anthracene bulk crystal, broad luminescence bands are observed in the middle concentration samples. For samples with less than 50% anthracene, broad luminescence bands are attributable to localized excited state at anthracene molecule pair which is accompanied by lattice relaxation. For samples with higher anthracene concentration, observed broad luminescence has lower peak energy than that of an anthracene bulk crystal. Origin of the luminescence is proposed to be excitation localized at fluorene impurity induced X‐traps in anthracene clusters. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lattice‐mismatch‐strain effects on excitons in GaAs1–xNx /GaAs heterostructures
Authors: Hashimoto Jun , Nakayama Masaaki
Published: September 2008

We have investigated the lattice‐mismatch‐strain effect on excitons in GaAs1‐x Nx (500 nm)/GaAs heterostructures with x = 0.4, 0.8, and 1.5% grown on a GaAs substrate using photoreflectance spectroscopy that is sensitive to excitonic transitions. It is found that the heavy‐hole (HH) and light‐hole (LH) excitons of the GaAs1‐x Nx layer, which are degenerate in a bulk crystal, are split and that the energy of the LH exciton is lower than that of the HH exciton. In this case, a quantum‐size effect is negligible because the GaAs1‐x Nx layer thickness is sufficiently thick. The HH‐LH splitting energy increases with an increase of nitrogen concentration (x) in addition to a drastic decrease of the energies of the HH and LH excitons. We have quantitatively analyzed the nitrogen‐concentration dependence of the energies of the HH and LH excitons, taking account of the lattice‐mismatch‐strain effect on the band structure and nitrogen‐induced giant bowing of the band‐gap energy. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural and electronic properties of Co‐doped ZnO nanocrystals synthesized by co‐precipitation method
Authors: Hasuike Noriyuki , Nishio Koji , Isshiki Toshiyuki , Kisoda Kenji , Harima Hiroshi
Published: September 2008

ZnO nanocrystals doped with Co were synthesized by co‐precipitation method combined with post‐thermal treatment. The synthesized crystals formed high‐quality wurtzite ZnO crystal lattice with the dimension about 10 nm, substituting Co ions into Zn sites in the composition range of [Co] < 3.0%. The position of Co2+/1+ charge transfer (CT) level composed by O 2p and Co 3d orbitals was observed at 3.0 eV by optical absorption measurements. Raman spectra showed the enhancement of LO phonon due to resonant Raman effect caused by photo‐excitation of free carriers mediated the CT level. And, Photoluminescence spectra showed UV emission at ∼3.3 eV suppressed and shifted to higher energy side with increase in Co doping level, indicating increase in nonradiative recombination centers and the possibility of band‐gap engineering in Zn1–xCoxO nanocrystals, respectively. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lost of coherence due to disorder in molecular rings
Authors: Heřman Pavel , Zapletal David , Barvík Ivan
Published: September 2008

The time dependence of the anisotropy of fluorescence can indicate the coherent exciton transfer regime.We are comparing time development of this quantity after an impulsive excitation obtained for the ring models of bacterial antenna complexes with tangential and radial optical transition dipole moments arrangement as in nonameric LH2 and octameric LH4 units.We compare its decay for three models of uncorrelated static Gaussian disorder: in the local exciton energies, in transfer integrals and in radial positions of molecules. Dynamic disorder is taken into account simultaneously using a Markovian treatment of the interaction with the bath. The influence of dimerization in molecular local energies, the strength of dynamic disorder and the shape of spectral density on difference of the anisotropy of fluorescence is shown and discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gain‐narrowed emissions of thiophene/phenylene co‐oligomer single crystals
Authors: Hiramatsu Toru , Matsuoka Naoki , Yanagi Hisao , Sasaki Fumio , Hotta Shu
Published: September 2008

In order to elucidate the origin of gain‐narrowed photoluminescence spectra of 5,5″‐bis(4‐biphenylyl)‐2,2′:5′,2″‐terthiophene (BP3T) single crystals, the dependence of excitation energy threshold on excitation lengths was studied at 12 K. The emission peak of the 0‐1 vibrational band was narrowed at a constant excitation density irrespective of the excitation length, indicating that the gain‐narrowing followed a stimulated emission process. On the other hand, the excitation density threshold for the 0‐2 peak decreased with increasing excitation length. The latter behaviour is suggestive of a cooperative interaction among uniaxially oriented transition dipoles in the BP3T crystal. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence properties of annealed InAs quantum dots capped by InGaAs layers
Authors: Hiratsuka Shingo , Saravanan Shanugam , Harayama Takahisa , Ohtani Naoki
Published: September 2008

We have investigated the annealing‐temperature dependence on photoluminescence (PL) properties of InAs quantum dots (QDs) fabricated on GaAs substrate. The annealing temperatures were varied from 700 to 1000 °C. The observed PL spectra were drastically changed by changing the annealing temperature. The PL peaking‐wavelength of non‐annealed sample is around 1200 nm. However, the peaking‐wavelength is drastically blue‐shifted with increasing annealing temperature. The strongest PL intensity is observed from the sample annealed at 875 °C. This PL intensity is more than seven fold compared with that of the non‐annealed sample. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theory of nano optical manipulation by designed light fields under excitonic resonance conditions
Authors: Iida Takuya , Yoshimizu Takashi , Ishihara Hajime
Published: September 2008

We theoretically study the resonant radiation force on a nanoparticle confining an exciton under the irradiation of various light sources that consist of Laguerre‐Gaussian beams (LGB) with doughnut‐shaped intensity distribution on a beam cross‐section and optical orbital angular momentum (OAM) around light axis. As a result, we have clarified possibilities of novel types of nano optical manipulation as follows: (A) Size‐selective control of rotational motion of nano‐objects can be realized by changing light frequency near the exciton resonance in multiple optical potential wells in a standing wave field composed of counter‐propagating LGBs with the same OAM. (B) Spiral‐shaped optical traps can be formed by the combination of LGBs with different OAMs. Obtained results will drastically expand the degrees of freedom of resonant nano optical manipulation by incorporating the control technique of the rotational motion in addition to those of the translational and the relative motions. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Four‐wave‐mixing study of exciton fine structure in GaN
Authors: Ishiguro T. , Toda Y. , Adachi S. , Tadatomo K. , Hoshino K.
Published: September 2008

Dephasing dynamics of exciton fine structure (EFS) caused by long and short range exchange interactions in GaN was investigated by using a four‐wave‐mixing (FWM) spectroscopy. The type of exchange interactions was selected by samples (uniaxially strained c ‐plane GaN films and a thick bulk GaN) and their geometries in optical excitation. Since each component of EFS is highly polarized, the polarization‐dependent FWM spectra successfully resolve the dephasing dynamics in the individual EFS resonances. The results show a difference in dephasing time, suggesting a contribution of anisotropic exchange interaction (AEI). (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In‐situ X‐ray diffraction of mechanically milled β‐Al3Mg2 powders
Authors: Scudino S. , Sakaliyska M. , Stoica M. , Surreddi K. B. , Ali F. , Vaughan G. , Yavari A. R. , Eckert J.
Published: September 2008

The structure evolution during heating of mechanically milled single‐phase β‐Al3Mg2 has been investigated by in‐situ X‐ray diffraction. The nanoscale supersaturated Al(Mg) solid solution formed during milling transforms back to the original β‐Al3Mg2 phase through a sequence of phase transformations. At low temperatures, an increasing amount of Mg is rejected from the solid solution with increasing temperature. At intermediate temperatures, the β′‐phase, a hexagonal phase with approximate composition Al3Mg2, forms. Finally, at higher temperatures the original β‐Al3Mg2 phase is restored, indicating that the formation of the supersaturated solid solution during milling can be reversed by appropriate heat treatment. The phase transformations during heating are gradual and the temperature ranges of stability of the different structure configurations are quite large, all exceeding 50 K. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hypothesis testing in an errors‐in‐variables model with heteroscedastic measurement errors
Authors: de Castro Mário , Galea Manuel , Bolfarine Heleno
Published: September 2008

In many epidemiological studies it is common to resort to regression models relating incidence of a disease and its risk factors. The main goal of this paper is to consider inference on such models with error‐prone observations and variances of the measurement errors changing across observations. We suppose that the observations follow a bivariate normal distribution and the measurement errors are normally distributed. Aggregate data allow the estimation of the error variances. Maximum likelihood estimates are computed numerically via the EM algorithm. Consistent estimation of the asymptotic variance of the maximum likelihood estimators is also discussed. Test statistics are proposed for testing hypotheses of interest. Further, we implement a simple graphical device that enables an assessment of the model's goodness of fit. Results of simulations concerning the properties of the test statistics are reported. The approach is illustrated with data from the WHO MONICA Project on cardiovascular disease. Copyright © 2008 John Wiley & Sons, Ltd.
The coupled dynamics of human socio‐economic choice and lake water system: the interaction of two sources of nonlinearity
Authors: Suzuki Yukari , Iwasa Yoh
Published: September 2008

We study a mathematical model for the coupled dynamics of human socio‐economic choice and lake water system. In the model, many players choose one of the two options: a cooperative and costly option with low phosphorus discharge, and an economical option with high phosphorus discharge. The choice is affected by an economic cost, a social concern about water pollution, and a conformist tendency. The pollution level in the lake is determined by total phosphorus discharge by the players, the sedimentation and the outflow of phosphorus, and the recycling of phosphorus from the sediment. The model has two sources of nonlinearity: the cooperation level tends to be bistable due to conformist tendency of people (social hysteresis) and pollution level tends to be bistable because phosphorus recycling occurs faster in more eutrophic lakes (ecological hysteresis). The combination of these two sources may cause multiple stable equilibria or oscillations with a long periodicity. Small economic cost and strong social concern about pollution level can decrease the pollution level, but may not be very effective in enhancing the cooperation level. In contrast, strong conformist tendency produces a stable state with a high cooperation level and a low pollution level. We discuss implications of these results to the water quality management.
An In‐vitro Investigation of Selected Biological Activities of Hydrolysed Flaxseed (Linum usitatissimum L.) Proteins
Authors: Marambe P. W. M. L. H. K. , Shand P. J. , Wanasundara J. P. D.
Published: September 2008

A study was conducted to determine bioactivities of flaxseed (Linum usitatissimum L.; variety: Valour) proteins and their hydrolysates. Isolated flaxseed proteins were treated with Flavourzyme® at different levels of enzyme to substrate ratio (E/S) and hydrolysis time. The unhydrolysed proteins and hydrolysates were studied for angiotensin I‐converting enzyme inhibiting (ACEI) activity, hydroxyl radical (OH·) scavenging activity and bile acid binding ability. Flavourzyme catalysed hydrolysis generated hydrolysates with a 11.94–70.62% degree of hydrolysis (DH). The hydrolysates (0.67 mg/ml) had strong ACEI activity (71.59–88.29%). The maximum ACEI activity containing hydrolysate exhibited an IC50 of 0.07 mg/ml (E/S: 1.5; Time: 12 h; DH: 11.94%). The OH· scavenging activity of the hydrolysates (0.5 mg/ml) was 12.48–22.08% with an IC50 of 1.56 mg/ml in the sample possessing maximum activity (E/S: 47.5; Time 0.7 h; DH: 24.63%). Both these activities were greater in hydrolysates with lower DH and higher peptide chain length (PCL) than those with higher DH and lower PCL. Hydrolysed flaxseed proteins (0.67 mg/ml) had no bile acid binding ability. The unhydrolysed proteins had no ACEI or OH· scavenging activity but demonstrated bile acid binding ability.
Metacognitive Therapy: Cognition Applied To Regulating Cognition
Authors: Wells Adrian
Published: September 2008

The theory and principles of Metacognitive therapy (MCT) are described and data supporting its effects are summarized. MCT does not advocate challenging of negative automatic thoughts or traditional schemas. It proposes the existence of a universal maladaptive thinking style that causes disorder and focuses on helping patients regulate their cognition more adaptively. It aims to reduce worry and rumination and alter problematic patterns of attention and coping. In doing so it targets underlying metacognition that controls thinking and helps patients develop new ways of consciously experiencing inner events. Data from treatment studies suggest that individual MCT techniques and full treatment are highly effective. Further randomized trials are clearly warranted.