bluuebunny/crossref_metadata_2025 huggingface dataset:
Comment on “The Use of Attrition Rates for Economic Loss Calculations in Employment Discrimination Cases: A Hypothetical Case Study”
Authors: Raymond Richard D.
Published: July 2010

No abstract available.
Time Series Properties of Capitalization Rates: A Comment and Extension
Authors: Payne James E. , Mohammadi Hassan
Published: July 2010

No abstract available.
Out-of-Step with Cohort Analysis: The Problems with “Plain and Fancy Regression” – A Reply
Authors: Peterson David W.
Published: July 2010

No abstract available.
Moisture effects on carbon and nitrogen emission from burning of wildland biomass
Authors: Chen L.-W. A. , Verburg P. , Shackelford A. , Zhu D. , Susfalk R. , Chow J. C. , Watson J. G.
Published: July 2010

Abstract. Carbon (C) and nitrogen (N) released from biomass burning have multiple effects on the Earth's biogeochemical cycle, climate change, and ecosystem. These effects depend on the relative abundances of C and N species emitted, which vary with fuel type and combustion conditions. This study systematically investigates the emission characteristics of biomass burning under different fuel moisture contents, through controlled burning experiments with biomass and soil samples collected from a typical alpine forest in North America. Fuel moisture in general lowers combustion efficiency, shortens flaming phase, and introduces prolonged smoldering before ignition. It increases emission factors of incompletely oxidized C and N species, such as carbon monoxide (CO) and ammonia (NH3). Substantial particulate carbon and nitrogen (up to 4 times C in CO and 75% of N in NH3) were also generated from high-moisture fuels, maily associated with the pre-flame smoldering. This smoldering process emits particles that are larger and contain lower elemental carbon fractions than soot agglomerates commonly observed in flaming smoke. Hydrogen (H)/C ratio and optical properties of particulate matter from the high-moisture fuels show their resemblance to plant cellulous and brown carbon, respectively. These findings have implications for modeling biomass burning emissions and impacts.
Physico-chemical characterization of secondary organic aerosol derived from catechol and guaiacol as a model substance for atmospheric humic-like substances
Authors: Ofner J. , Krüger H.-U. , Grothe H. , Schmitt-Kopplin P. , Whitmore K. , Zetzsch C.
Published: July 2010

Abstract. Secondary organic aerosol was produced from the aromatic precursors catechol and guaiacol by reaction with ozone in the presence and absence of simulated sunlight and humidity and investigated for its properties as a proxy for humic-like substances (HULIS). Beside a small particle size, a relatively low molecular weight and typical optical features in the UV/VIS spectral range, HULIS contain a typical aromatic and/or olefinic chemical structure and highly oxidized functional groups within a high chemical diversity. Various methods were used to characterize the secondary organic aerosols obtained: Fourier transform infrared spectroscopy (FTIR) demonstrated the formation of different carbonyl containing functional groups as well as structural and functional differences between aerosols formed at different environmental conditions. UV/VIS spectroscopy of filter samples showed that the particulate matter absorbs far into the visible range up to more than 500 nm. Ultrahigh resolved mass spectroscopy (ICR-FT/MS) determined O/C-ratios between 0.3 and 1 and main molecular weights between 200 and 500 Da. Temperature-programmed-pyrolysis mass spectroscopy identified carboxylic acids and lactones as major functional groups. Particle sizing using CNC-DMPS demonstrated the formation of small particles during a secondary organic aerosol formation process. Particle imaging using field-emission-gun scanning electron microscopy (FEG-SEM) showed spherical particles, forming clusters and chains. Hence, secondary organic aerosols from catechol and guaiacol are appropriate model substances for studies of the processing of aromatic secondary organic aerosols and atmospheric HULIS on the laboratory scale.
Ultraphytoplankton basin-scale distribution in the eastern Mediterranean Sea in winter: link to hydrodynamism and nutrients
Authors: Denis M. , Thyssen M. , Martin V. , Manca B. , Vidussi F.
Published: July 2010

Abstract. The basin-scale distribution of ultraphytoplankton (<10 μm) was determined in the upper 200 m of the eastern Mediterranean Sea during the winter season. Four clusters were resolved by flow cytometry on the basis of their optical properties and identified as Synechococcus, Prochlorococcus, pico- (<3 μm) and nanoeukaryotes (3–10 μm). Synechococcus was the most abundant population (maximum abundance of about 37 000 cells cm−3) and contributed up to 67.7% to the overall ultraphytoplanktonic carbon biomass, whereas the contribution of Prochlorococcus never exceeded 6.5%. The maximum integrated carbon biomass was 1763, 453, 58 and 571 mg C m−2 for nanoeukaryotes, picoeukaryotes, Prochlorococcus and Synechococcus respectively. Water mass properties were analyzed on the basis of temperature and salinity distributions in order to account for the general circulation and locate the main hydrodynamic structures (fronts, gyres, transition between western and eastern basins). The effect of the main hydrodynamic structures and nutrients on the ultraphytoplankton distribution was investigated. No positive correlation between nutrients and phytoplankton could be established when considering large scales. However, below 50 m depth, nutrient ratios between particular stations were correlated to corresponding density ratios. In contrast, significant relationships were found between Synechococcus abundance and density, resulting from the impact of a gyre in southern Adriatic basin and a thermohaline front in the Ionian basin. A significant relationship was also found between picoeukaryotes and salinity in the comparison of western and eastern Mediterranean Sea.
Wirkstoffverabreichung mithilfe polymerer Mehrschichtkapseln
Authors: De Cock Liesbeth J. , De Koker Stefaan , De Geest Bruno G. , Grooten Johan , Vervaet Chris , Remon Jean Paul , Sukhorukov Gleb B. , Antipina Maria N.
Published: July 2010

Die Fortschritte der letzten Jahre in Medizin und Biotechnologie haben die Entwicklung von Transportsystemen im Nanomaßstab dringlich gemacht, die eine Vielzahl an neuartigen Therapeutika wie Proteine, Chemotherapeutika und Nucleinsäuren einschließen können. Zudem sollten diese Transportsysteme “intelligent” sein, d. h., sie sollten ihre Ladung zu einer festgelegten Zeit, an einem bestimmten Ort oder nach einer spezifischen Stimulierung abladen können. Seit polymere Mehrschichtkapseln verfügbar sind, die durch mehrstufiges Beschichten eines Opfertemplats und anschließendes Auflösen dieses Templats hergestellt werden, ist es möglich, Mikrokapseln unter rein wässrigen Bedingungen mithilfe einfacher Baustein‐ und Assoziationsverfahren gezielt herzustellen, was eine bislang unerreichte Steuerung der Mikrokapselfunktionalität erlaubt. Inzwischen sind polymere Mehrschichtkapseln auf zunehmendes Interesse in den Biowissenschaften gestoßen, und viele interessante Systeme mit bioabbaubaren Bestandteilen und biospezifischen Funktionen wurden beschrieben. In dieser Übersicht werden die neuesten Durchbrüche beim Einsatz für die Wirkstoffverabreichung vorgestellt.
A structuration approach to online communities of practice: The case of Q&A communities
Authors: Rosenbaum Howard , Shachaf Pnina
Published: July 2010

This article describes an approach based on structuration theory (Giddens, 1979, 1984; Orlikowski, 1992, 2000) and communities of practice (Wenger, 1998) that can be used to guide investigation into the dynamics of online question and answer (Q&A) communities. This approach is useful because most research on Q&A sites has focused attention on information retrieval, information‐seeking behavior, and information intermediation and has assumed uncritically that the online Q&A community plays an important role in these domains of study. Assuming instead that research on online communities should take into account social, technical, and contextual factors (Kling, Rosenbaum, & Sawyer, 2005), the utility of this approach is demonstrated with an analysis of three online Q&A communities seen as communities of practice. This article makes a theoretical contribution to the study of online Q&A communities and, more generally, to the domain of social reference.
Abstraction Assistant: An automatic text abstraction system
Authors: Wang Wendy , Hwang Drew
Published: July 2010

In the interest of standardization and quality assurance, it is desirable for authors and staff of access services to follow the American National Standards Institute (ANSI) guidelines in preparing abstracts. Using the statistical approach an extraction system (the Abstraction Assistant) was developed to generate informative abstracts to meet the ANSI guidelines for structural content elements. The system performance is evaluated by comparing the system‐generated abstracts with the author's original abstracts and the manually enhanced system abstracts on three criteria: balance (satisfaction of the ANSI standards), fluency (text coherence), and understandability (clarity). The results suggest that it is possible to use the system output directly without manual modification, but there are issues that need to be addressed in further studies to make the system a better tool.
Design and Preparation of Co‐crystals Utilizing the ${{\bf R}{{ \bf 2\hfill \atop \bf 4\hfill}}}$(8) Hydrogen‐Bonding Motif
Authors: Bernstein Joel , Novoa Juan J. , Boese Roland , Cirkel Sebastian A.
Published: July 2010

An investigation of the feasibility of utilizing a specific, and previously largely unrecognized, hydrogen‐bonded synthon for the design and preparation of co‐crystals is reported. Structural evidence (i.e., >12 000 instances) indicated the robustness of the cyclic${{\rm{R}}_4^2 (8)}$hydrogen‐bonded motif containing, in most cases, four individual (either identical or different) molecules, in which the donor substituent (e.g., an amine) can provide two hydrogen‐bond donors, and the acceptor (e.g., a carbonyl oxygen) can provide two hydrogen‐bond acceptors. The energetic robustness of the motif with respect to chemical substitution and charge on the component molecules was investigated and confirmed in a series of fully optimized calculations at the MP2/6‐31+G(d) level. A proof‐of‐concept experiment to prepare a co‐crystal between a prototypical ketone and a primary amine yielded the crystal structure reported herein, in which the hydrogen bonds between the co‐crystal components indeed exhibit exclusively the designed and sought‐after${{\rm{R}}_4^2 (8)}$motif.
Highly Efficient Visible Light Plasmonic Photocatalyst Ag@Ag(Br,I)
Authors: Wang Peng , Huang Baibiao , Zhang Qianqian , Zhang Xiaoyang , Qin Xiaoyan , Dai Ying , Zhan Jie , Yu Jiaoxian , Liu Haixia , Lou Zaizhu
Published: July 2010

The new plasmonic photocatalyst Ag@Ag(Br,I) was synthesized by the ion‐exchange process between the silver bromide and potassium iodide, then by reducing some Ag+ ions in the surface region of Ag(Br,I) particles to Ag0 species. Ag nanoparticles are formed from Ag(Br,I) by the light‐induced chemical reduction reaction. The Ag@Ag(Br,I) particles have irregular shapes with their sizes varying from 83 nm to 1 μm. The as‐grown plasmonic photocatalyst shows strong absorption in the visible light region because of the plasmon resonance of Ag nanoparticles. The ability of this compound to reduce CrVI under visible light was compared with those of other reference photocatalyst. The plasmonic photocatalyst is shown to be highly efficient under visible light. The stability of the photocatalyst was examined by X‐ray diffraction and X‐ray photoelectron spectroscopy. The XRD pattern and XPS spectra prove the stability of the plasmonic photocatalyst Ag@Ag(Br,I).
An Investigation into the Optimum Thickness of Titanium Dioxide Thin Films Synthesized by Using Atmospheric Pressure Chemical Vapour Deposition for Use in Photocatalytic Water Oxidation
Authors: Hyett Geoffrey , Darr Jawwad A. , Mills Andrew , Parkin Ivan P.
Published: July 2010

Twenty eight films of titanium dioxide of varying thickness were synthesised by using atmospheric pressure chemical vapour deposition (CVD) of titanium(IV) chloride and ethyl acetate onto glass and titanium substrates. Fixed reaction conditions at a substrate temperature of 660 °C were used for all depositions, with varying deposition times of 5–60 seconds used to control the thickness of the samples. A sacrificial electron acceptor system composed of alkaline sodium persulfate was used to determine the rate at which these films could photo‐oxidise water in the presence of 365 nm light. The results of this work showed that the optimum thickness for CVD films on titanium substrates for the purposes of water oxidation was ≈200 nm, and that a platinum coating on the reverse of such samples leads to a five‐fold increase in the observed rate of water oxidation.
Redox Sorption and Recovery of Silver Ions as Silver Nanocrystals on Poly(aniline‐co‐5‐sulfo‐2‐anisidine) Nanosorbents
Authors: Li Xin‐Gui , Feng Hao , Huang Mei‐Rong
Published: July 2010

Poly[aniline(AN)‐co‐5‐sulfo‐2‐anisidine(SA)] nanograins with rough and porous structure demonstrate ultrastrong adsorption and highly efficient recovery of silver ions. The effects of five key factors—AN/SA ratio, AgI concentration, sorption time, ultrasonic treatment, and coexisting ions—on AgI adsorbability were optimized, and AN/SA (50/50) copolymer nanograins were found to exhibit much stronger AgI adsorption than polyaniline and all other reported sorbents. The maximal AgI sorption capacity of up to 2034 mg g−1 (18.86 mmol g−1) is the highest thus far and also much higher than the maximal Hg‐ion sorption capacity (10.28 mmol g−1). Especially at ≤2 mM AgI, the nanosorbents exhibit ≥99.98 % adsorptivity, and thus achieve almost complete AgI sorption. The sorption fits the Langmuir isotherm well and follows pseudo‐second‐order kinetics. Studies by IR, UV/Vis, X‐ray diffraction, polarizing microscopy, centrifugation, thermogravimetry, and conductivity techniques showed that AgI sorption occurs by a redox mechanism mainly involving reduction of AgI to separable silver nanocrystals, chelation between AgI and NH/N/NH2/ SO3H/OCH3, and ion exchange between AgI and H+ on SO3−H+. Competitive sorption of AgI with coexisting Hg, Pb, Cu, Fe, Al, K, and Na ions was systematically investigated. In particular, the copolymer nanoparticles bearing many functional groups on their rough and porous surface can be directly used to recover and separate precious silver nanocrystals from practical AgI wastewaters containing Fe, Al, K, and Na ions from Kodak Studio. The nanograins have great application potential in the noble metals industry, resource reuse, wastewater treatment, and functional hybrid nanocomposites.
Density Functional Calculations of 55Mn, 14N and 13C Electron Paramagnetic Resonance Parameters Support an Energetically Feasible Model System for the S2 State of the Oxygen‐Evolving Complex of Photosystem II
Authors: Schinzel Sandra , Schraut Johannes , Arbuznikov Alexei V. , Siegbahn Per E. M. , Kaupp Martin
Published: July 2010

Metal and ligand hyperfine couplings of a previously suggested, energetically feasible Mn4Ca model cluster (SG2009−1) for the S2 state of the oxygen‐evolving complex (OEC) of photosystem II (PSII) have been studied by broken‐symmetry density functional methods and compared with other suggested structural and spectroscopic models. This was carried out explicitly for different spin‐coupling patterns of the S=1/2 ground state of the MnIII(MnIV)3 cluster. By applying spin‐projection techniques and a scaling of the manganese hyperfine couplings, computation of the hyperfine and nuclear quadrupole coupling parameters allows a direct evaluation of the proposed models in comparison with data obtained from the simulation of EPR, ENDOR, and ESEEM spectra. The computation of 55Mn hyperfine couplings (HFCs) for SG2009−1 gives excellent agreement with experiment. However, at the current level of spin projection, the 55Mn HFCs do not appear sufficiently accurate to distinguish between different structural models. Yet, of all the models studied, SG2009−1 is the only one with the MnIII site at the MnC center, which is coordinated by histidine (D1‐His332). The computed histidine 14N HFC anisotropy for SG2009−1 gives much better agreement with ESEEM data than the other models, in which MnC is an MnIV site, thus supporting the validity of the model. The 13C HFCs of various carboxylates have been compared with 13C ENDOR data for PSII preparations with 13C‐labelled alanine.
3‐Fluoroaspartate and Pyruvoyl‐Dependant Aspartate Decarboxylase: Exploiting the Unique Characteristics of Fluorine To Probe Reactivity and Binding
Authors: de Villiers Jandré , Koekemoer Lizbé , Strauss Erick
Published: July 2010

Fluorine‐containing amino acids have been used with great success as mechanism‐based inhibitors of pyridoxal phosphate (PLP)‐dependent enzymes, and the influence of fluorine on the conformation of molecules has also been extensively studied and practically exploited. In this study, we sought to use these unique characteristics to probe the reactivity and binding of aspartate decarboxylase (ADC) enzymes, which are members of the small class of pyruvoyl‐dependant decarboxylases. Since ADC activity has been shown to be essential to the virulence of Mycobacterium tuberculosis, information gained in this manner could be used for the development of inhibitors that selectively target pyruvoyl‐dependent enzymes such as ADC, without affecting PLP‐dependent enzymes in the host. For this purpose, we synthesized the L‐erythro and L‐threo isomers of 3‐fluoroaspartate and tested their ability to act as substrates and/or inhibitors of the M. tuberculosis and Escherichia coli ADC enzymes. Trapping and MS‐based binding analysis was additionally used to confirm that both isomers enter the enzymes’ active sites. Our studies show that both isomers undergo single turnover decarboxylation and fluorine elimination reactions to give enamine products that can be trapped within the active site. Interestingly, the enamine/ADC complex that forms from the L‐erythro (but not the L‐threo) isomer is sufficiently stable that it can be observed even without any trapping. This finding suggests that the two 3‐fluoroaspartates maintain different conformations within the ADC active site, which leads to the enamine products with configurations of different stabilities. Taken together, our results provide new insights for the development of cofactor‐specific inhibitors, and confirm the utility of fluorine as a unique tool for probing reactivity and binding profiles within enzymes.
Multichromophoric Phthalocyanine–(Perylenediimide)8 Molecules: A Photophysical Study
Authors: Albert‐Seifried Sebastian , Finlayson Chris E. , Laquai Frederic , Friend Richard H. , Swager Timothy M. , Kouwer Paul H. J. , Juríček Michal , Kitto Heather J. , Valster Sanne , Nolte Roeland J. M. , Rowan Alan E.
Published: July 2010

We describe the synthesis of a series of phthalocyanine (Pc)–perylenediimide (PDI)8 “octad” molecules, in which eight PDI moieties are attached to a Pc core through alkyl‐chain linkers. There is clear spectroscopic evidence that these octads can exist as non‐aggregated “monomers” or form aggregates along the Pc cores, depending on the type of Pc and the solvent medium. In the low dielectric constant solvents, into which the octads are soluble, photoexcitation of the PDI units leads to rapid energy transfer to the Pc centre, rather than a charge separation between moieties. In octad monomers, the Pc singlet excited‐state decays within tens of ps, whereas the excitons are stabilised in the aggregated form of the molecules, typically with lifetimes in the order of 1–10 ns. By contrast, in an octad design in which π–π interactions are suppressed by the steric hindrance of a corona of incompatible glycol tails around the molecule, a more straightforward photophysical interaction of Förster energy transfer between the PDI moieties and Pc core may be inferred. We consider these molecules as prototypical multichromophoric aggregates, giving delocalised states with considerable flexibility of design.
Highly Enantioselective Synthesis of α‐Stereogenic Esters through Catalytic Asymmetric Michael Addition of 4‐Oxo‐4‐arylbutenoates
Authors: Wang Zhen , Chen Donghui , Yang Zhigang , Bai Sha , Liu Xiaohua , Lin Lili , Feng Xiaoming
Published: July 2010

Highly enantioselective Michael addition of 1,3‐dicarbonyl compounds and nitromethane to 4‐oxo‐4‐arylbutenoates catalyzed by N,N′‐dioxide–Sc(OTf)3 complexes has been developed. Using 0.5–2 mol % catalyst loading, various α‐stereogenic esters were obtained regioselectively with excellent yields (up to 97 %) and enantioselectivities (up to >99 % ee). Moreover, the reaction performed well under nearly solvent‐free conditions. The products with functional groups are ready for further transformation, which showed the potential value of the catalytic approach. According to the experimental results and previous reports, a plausible working model has been proposed to explain the origin of the activation and the asymmetric induction.
DFT Investigation of the Palladium‐Catalyzed Ene–Yne Coupling
Authors: Henriksen Signe Teuber , Tanner David , Skrydstrup Troels , Norrby Per‐Ola
Published: July 2010

The mechanism of the recently developed palladium‐catalyzed ene–yne coupling has been evaluated by DFT methods. The calculations validate the previously proposed reaction mechanism and explain the stereoselectivity of the reaction (exclusive formation of the E isomer of the disubstituted alkene). Concerning chemoselectivity, the calculations also clarify why the ene–yne coupling is able to dominate over plausible alternative reaction pathways such as alkene homocoupling and alkyne polymerization. The role of the phosphine ligand at various stages of the catalytic cycle has also been delineated.
Synthesis of Diverse Indole‐Containing Scaffolds by Gold(I)‐Catalyzed Tandem Reactions of 3‐Propargylindoles Initiated by 1,2‐Indole Migrations: Scope and Computational Studies
Authors: Sanz Roberto , Miguel Delia , Gohain Mukut , García‐García Patricia , Fernández‐Rodríguez Manuel A. , González‐Pérez Adán , Nieto‐Faza Olalla , de Lera Ángel R. , Rodríguez Félix
Published: July 2010

Similar to propargylic carboxylates and sulphides, 3‐propargylindoles undergo 1,2‐indole migrations under cationic gold(I) catalysis. The intermediate Au–carbenoid complex may evolve through different pathways depending on the substituents at the propargylic and terminal positions of the alkyne moiety. Thus, 3‐indenylindole derivatives were easily obtained through formal iso‐Nazarov or Nazarov cyclizations. DFT computations support the formation of an alkylidenecyclopropane intermediate that undergoes gold‐iso‐Nazarov or gold‐Nazarov cyclizations upon torquoselective ring opening. In addition, 3‐dienylindoles could be accessed when none of the referred pathways were accessible and so the intermediate Au–carbenoid complex evolved via a 1,2‐CH insertion reaction. We have also demonstrated that the final products can be obtained in a one‐pot protocol from easily available propargylic alcohols and indoles.
Erythroid Induction of Chronic Myelogenous Leukemia K562 Cells Following Treatment with a Photoproduct Derived from the UV‐A Irradiation of 5‐Methoxypsoralen
Authors: Salvador Alessia , Dall'Acqua Stefano , Sardo Manlio Sutera , Caffieri Sergio , Vedaldi Daniela , Dall'Acqua Francesco , Borgatti Monica , Zuccato Cristina , Bianchi Nicoletta , Gambari Roberto
Published: July 2010

Induction of terminal erythroid differentiation can be an efficient strategy to inhibit proliferation of chronic myelogenous leukemia cells. Psoralens, well‐known photo‐chemotherapeutic agents, were found to be efficient at inducing erythroid differentiation of K562 cells, an in vitro cell line isolated from the pleural effusion of a patient with chronic myelogenous leukemia in blast crisis. The effects of crude pre‐irradiated solutions of 5‐methoxypsoralen on erythroid differentiation of human leukemic K‐562 cells were evaluated. The major photoproduct was characterized and analyzed, and it was found to induce erythroid differentiation of K562 cells and inhibit NF‐κB/DNA interactions.
Evaluation of a breast cancer risk prediction model expanded to include category of prior benign breast disease lesion
Authors: Tamimi Rulla M. , Rosner Bernard , Colditz Graham A.
Published: July 2010

BACKGROUND:

Benign breast diseases (BBD) encompass several histologic subtypes with various risks of subsequent breast cancer. Information on previous benign breast disease biopsies has been incorporated into breast cancer risk prediction models; however, the type of histologic lesion has not been taken into account. Given the substantial heterogeneity in breast cancer risk dependent on the type of benign lesion, the authors evaluated whether incorporating this level of detail would improve the discriminatory power of risk classification models.

METHODS:

By using data from the Nurses' Health Study, a breast cancer nested case‐control study (240 cases; 1036 controls), the authors determined predictors of categories of BBD lesions and developed imputation models. The type of BBD, imputed for each cohort member who reported a diagnosis, was added to a modified version of the Rosner‐Colditz breast cancer risk prediction model.

RESULTS:

Compared with the model that included only previous BBD (yes/no), the model that included categories of BBD was significantly improved (P < .0001). Overall, including the category of BBD increased the concordance statistic from 0.628 to 0.635. By using risk reclassification, inclusion of the type of BBD resulted in a 17% increase in incidence per increase of 1 risk decile, holding the model without BBD type risk decile constant.

CONCLUSIONS:

Although the current data suggested that the inclusion of BBD category may improve breast cancer risk classification, the clinical utility of such a model will depend on the consistency of histologic classification of benign breast disease lesions. Cancer 2010. © 2010 American Cancer Society.
Two‐dimensional recursive digital filters with nearly circular‐symmetric magnitude response and approximately linear phase
Authors: Lee Ju‐Hong , Yang Yuan‐Hau
Published: July 2010

This paper presents a general structure using 1‐D and two‐dimensional (2‐D) recursive digital all‐pass filters (DAFs) for the design of 2‐D recursive circularly symmetric digital low‐pass filters (CS‐DLFs). The general structure is a cascade of two stages composed of all‐pass building blocks. The first stage is a parallel connection of a 2‐D recursive DAF with a symmetric half‐plane (SHP) support for its filter coefficients and a 2‐D pure delay block. The second stage composed of a parallel connection of a 1‐D recursive DAF and a 1‐D pure delay block is used for eliminating the unwanted pass‐band induced by the first stage. As a result, the design of a 2‐D CS‐DLF in either the least‐squares or the minimax sense can be formulated in a simple linear optimization problem in terms of the weighted‐phase response error for each DAF. Design results with nearly circularly symmetric magnitude response and approximately linear phase are also provided for illustration and comparison. Copyright © 2010 John Wiley & Sons, Ltd.
Simultaneous chemometric determination of pyridoxine hydrochloride and isoniazid in tablets by multivariate regression methods
Authors: Dinç Erdal , Üstündağ Özgür , Baleanu Dumitru
Published: July 2010

The sole use of pyridoxine hydrochloride during treatment of tuberculosis gives rise to pyridoxine deficiency. Therefore, a combination of pyridoxine hydrochloride and isoniazid is used in pharmaceutical dosage form in tuberculosis treatment to reduce this side effect. In this study, two chemometric methods, partial least squares (PLS) and principal component regression (PCR), were applied to the simultaneous determination of pyridoxine (PYR) and isoniazid (ISO) in their tablets. A concentration training set comprising binary mixtures of PYR and ISO consisting of 20 different combinations were randomly prepared in 0.1 M HCl. Both multivariate calibration models were constructed using the relationships between the concentration data set (concentration data matrix) and absorbance data matrix in the spectral region 200–330 nm. The accuracy and the precision of the proposed chemometric methods were validated by analyzing synthetic mixtures containing the investigated drugs. The recovery results obtained by applying PCR and PLS calibrations to the artificial mixtures were found between 100.0 and 100.7%. Satisfactory results obtained by applying the PLS and PCR methods to both artificial and commercial samples were obtained. The results obtained in this manuscript strongly encourage us to use them for the quality control and the routine analysis of the marketing tablets containing PYR and ISO drugs. Copyright © 2010 John Wiley & Sons, Ltd.
A rapid strategy to detect the recombined allele in LSL‐TβRICA transgenic mice
Authors: Vincent David F. , Kaniewski Bastien , Powers Shannon E. , Havenar‐Daughton Colin , Marie Julien C. , Wotton David , Bartholin Laurent
Published: July 2010

We have previously generated a transgenic mouse strain (LSL‐TβRICA) containing a Cre‐inducible constitutively active TGFβ type I receptor (Bartholin et al., 2008, Genesis 46: 724–731). Transgene expression depends on the excision of a floxed‐transcriptional STOP (LSL, Lox‐STOP‐Lox) located upstream the TβRICA coding sequence. To evaluate the correct excision of the STOP signal in the presence of Cre‐recombinase, we developed a rapid screening based on an original PCR genotyping strategy. More precisely, we designed a set of primers flanking the LSL containing region. The size of the amplified products will differ according to recombination status of the LSL‐TβRICA allele. Indeed, the size of the STOP containing PCR product is 1.93 kb, but is reduced to 0.35 kb when the STOP signal is removed after Cre‐mediated recombination. We validated excision in several compartments, including pancreas, liver, T lymphocytes, and embryos using different Cre expressing transgenic mouse strains. This represents a simple and efficient way of monitoring the tissue specific recombination of the LSL‐TβRICA allele. genesis 48:559–562, 2010. © 2010 Wiley‐Liss, Inc.
Effect of water absorption temperature on space charge profiles in paper/phenol‐resin composites for printed circuit boards
Authors: Echigo Yasutsune , Natsui Masashi , Maeno Takashi , Ohki Yoshimichi
Published: July 2010

More and more electronics are intended for use in adverse environments at high temperatures with high humidity. The spatial distributions of internal charge carriers, mainly due to ionic impurities that appear in hot and humid environments, are considered to affect the reliability of bulk insulation. Therefore, the authors examined space charge behavior inside paper/phenol‐resin composites for printed circuit boards under DC voltages, focusing on the effect of the water absorption temperature. Both the sample weight and thickness were increased monotonically by immersion in water with an increase in the water temperature from 24 to 85 , indicating that the water absorption by the sample was temperature dependent. In the early periods of water absorption (up to 10 hours), the electric field decreased near the two electrodes and increased in the other regions. Furthermore, heterocharge formation was observed near the cathode as the water absorption progressed, becoming more significant at higher water temperatures. Ion chromatography analyses detected numerous ions such as Na+, $NH_{4}^{+}$ and Cl‐ from the water, in which the sample had been immersed for 100 hours at various temperatures. It is highly possible that these ions are responsible for the heterocharge formation. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(2): 1–7, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20992
Hydropower output forecast with tank models combined with Kalman filter estimation
Authors: Ofuji Kenta , Yamaguchi Nobuyuki , Hoshino Kazumi , Sakamoto Masaaki
Published: July 2010

In this paper, we study how to forecast the next‐day expected output of hydropower energy based on the past rainfall record in the reference area. The Tank Model, which has been conventionally applied to this type of forecast, has been improved by employing Kalman filter stepwise estimation in order to accommodate seasonal and yearly variations of rainfall water runoff conditions. Our Kalman Filter Tank Model (KF‐Tank Model) yielded a broader choice of parameters while maintaining an acceptable average forecast error level of about ±0.05 PU per forecast period. It is also shown that the error correction mechanism of the KF Tank Model can remain robust to snowfall and snowmelt seasons without requiring parameter revisions of the model. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(2): 33–41, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20995
Research on magnetron phased array with mutual injection locking for space solar power satellite/station
Authors: Shinohara Naoki , Matsumoto Hiroshi
Published: July 2010

The SPS (Space Solar Power Satellite/Station) will be a clean base‐load power station in space. It will be the largest space system ever built and will require a high‐efficiency, large‐size, highly accurate, lightweight, inexpensive phased array in order to transmit energy generated in space to the ground. We have proposed and developed a phase‐controlled magnetron (PCM) with injection locking and PLL technique for the high‐efficiency, lightweight, inexpensive phased array. It still has several weak points: (1) approximately 10% power loss occurs at the circulator for injection locking, (2) phase shifter is needed in each PCM for the phased array. In order to correct the weak points, we propose a magnetron phased array with mutual injection locking. For the magnetron phased array, we only use two PCMs with phase shifters; the other components are self‐oscillated and mutual injection locked magnetrons. In this paper, we propose a new formula for use with the magnetron phased array with mutual injection locking. We also present the results of experiments on beam direction control with the magnetron phased array with mutual injection locking. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(2): 21–32, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20998
A feasibility study of pressure‐retarded osmosis power generation system based on measuring permeation volume using reverse osmosis membrane
Authors: Enomoto Hiroshi , Fujitsuka Masashi , Hasegawa Tomoyasu , Kuwada Masatoshi , Tanioka Akihiko , Minagawa Mie
Published: July 2010

A pressure‐retarded osmosis (PRO) power generation system is a hydroelectric power system which utilizes permeation flow through a semipermeable membrane. Permeation flow is generated by the potential energy of the salinity difference between sea water and fresh water. Since the cost of the membrane is high, the permeation performance of the membrane must be improved in order to realize PRO systems. We have investigated reverse osmosis (RO) membrane products as semipermeable membranes and measured the permeation volume of a few products. The generation power per unit membrane area calculated from the permeation volume is about 0.62 W/m2. But as a result of our improvements (greater salt water volume, spacers for fresh water channel with the function of discharging concentrated salinity, extralow‐pressure type of membrane, washing the support layer of membrane when the generation power falls by half) the generated power may be 2.43 W/m2. Then the power system cost would be about 4.1 million yen/kW. In addition, if the support layer of the membrane is made thinner and a PRO system is applied to equipment where pumping power for another purpose is available (wastewater treatment plants located at the seaside, thermal and nuclear power plants, sea water desalination plants), the generated power may be increased. These improvements may enable PRO systems to be realized at a cost close to that of photovoltaic power systems. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(2): 8–20, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.21000
Harmonic current suppression for PMSM by repetitive perfect tracking control
Authors: Nakai Takahiro , Fujimoto Hiroshi
Published: July 2010

PM motor drives are widely used for high‐performance servo applications. However, the PM motor has an imperfect sinusoidal flux distribution which causes harmonic currents. Inverter dead time and current measurement error also lead to harmonic currents. The repetitive control method has been applied to current suppression. For repetitive control based on the internal model principle, the harmonic suppression characteristics are excellent. However, interharmonic components are amplified. The interharmonic components have frequencies that are nonintegral multiples of the fundamental frequency. Therefore, feedforward compensation is applied for the harmonic currents to improve the suppression characteristic. The authors propose harmonic current suppression control of a PM motor in αβ coordinates by using repetitive perfect tracking control with the PWM‐hold model. The advantages of the proposed method are shown by simulations and experiments. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(2): 55–63, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ eej.21009
Iodate Sensing Electrodes Based on Phosphotungstate‐ Doped‐Glutaraldehyde‐Cross‐Linked Poly‐L‐lysine Coatings
Authors: Thangamuthu R. , Pan Yu‐Ching , Chen Shen‐Ming
Published: July 2010

Glassy carbon electrode modified with phosphotungstate‐doped‐glutaraldehyde‐cross‐linked poly‐L‐lysine (PLL‐GA‐PW) film was employed for iodate determination. The PLL‐GA‐PW film electrode shows excellent electrocatalytic activity towards iodate reduction with significant reduction of overpotential. Under optimized experimental conditions, a linear range from 5×10−8 to 2.27×10−2 M with a sensitivity of 61.75 μA mM−1 was obtained. Possible interfering species, in iodate determination, were evaluated and the applicability of proposed sensor for iodate estimation in table salt was also demonstrated. The PLL‐GA‐PW film electrode shows fast response, wider linear range, and good selectivity and stability.
Electrochemically Monitoring the Acid and Acidic Urea‐Induced Unfolding of Hemoglobin and Its Electrocatalytic Ability
Authors: Zhao Xiaojuan , Mai Zhibin , Dai Zong , Zou Xiaoyong
Published: July 2010

Acid and acidic urea‐induced unfolding of hemoglobin (Hb) was investigated using protein‐film‐based electrochemical method. The conformational transition of Hb was monitored through the change of direct electrochemical response of Hb. The heme groups in Hb detached from their native binding sites after pH<4.0. Spectral experiments fully supported the results. Furthermore, the catalytic ability of Hb was enhanced 15 times under the optimal unfolded conditions of pH 2.0 PBS containing 3.0 mol L−1 urea. The method contributes to understand the relationship between function and conformation of Hb, and provides possibility of manipulating protein function by controlling its conformation.
Flow‐Injection Differential‐Pulse Anodic Stripping Voltammetry as a Tool for Thallium Monitoring in the Environment
Authors: Lukaszewski Zenon , Jakubowska Monika , Zembrzuski Wlodzimierz , Karbowska Bozena , Pasieczna Anna
Published: July 2010

In order to demonstrate the applicability of the Flow‐Injection Differential‐Pulse Anodic Stripping Voltammetry to monitoring of thallium in the environment, thallium concentration in water, bottom sediments and the soil of flood‐plain terraces of two rivulets were investigated. It is shown, that thallium containing particles are transported by rivulets and are deposited in bottom sediments (7.4 and 1.7 μg g−1downstream, respectively). Thallium originating from this source is dispersed in flood‐plain valley soil and is dissolved in rivulet water. Thallium concentration in water (0.32 and 0.21 μg L−1 downstream , respectively) exceeds the normal level by 20–30 times.
Thermal transformations of some monoterpene compounds in supercritical lower alcohols
Authors: Anikeev V. I.
Published: July 2010

This review systematizes the results of basic studies on thermal transformations of phytogenic terpene compounds (α‐ and β‐pinenes, turpentine, cis‐verbenol) performed in supercritical lower alcohols. The main result is the demonstration of a considerable increase in the rate of thermal isomerization of monoterpene compounds in supercritical lower alcohols, with the retained selectivity toward target products of the reaction as compared to the rate of similar reactions conducted in the gas or liquid phase. The kinetic studies provided a deep insight into the isomerization mechanism of these compounds and elucidated the role of supercritical solvent in a manifold increase of the reaction rate compared to isomerization of the same compounds in the gas or liquid phase. The pressure of a supercritical solvent was shown to strongly facilitate the acceleration of the reactions under study. Chemical transformations of the considered terpene compounds in supercritical fluid solvents can be used as a basis of modern highly efficient technologies for the production of a wide range of practically important organic compounds, medicinal and perfume substances. Copyright © 2010 John Wiley & Sons, Ltd.
Focal experimental autoimmune encephalomyelitis in the lewis rat induced by immunization with myelin oligodendrocyte glycoprotein and intraspinal injection of vascular endothelial growth factor
Authors: Sasaki Masanori , Lankford Karen L. , Brown Robert J. , Ruddle Nancy H. , Kocsis Jeffery D.
Published: July 2010

Various models of experimental autoimmune encephalomyelitis (EAE) have led to insights into the pathogenesis and novel therapies for multiple sclerosis. One generalized EAE model uses immunizing the Lewis Rat with myelin oligodendrocyte glycoprotein (MOG) and complete Freund's adjuvant that induces systemic disease and inflammatory lesions at random central nervous system (CNS) locations. These lesions result from a combination of sensitized T cells and pathogenic antibodies gaining access to the CNS to cause an immune assault on myelin‐expressing oligodendrocytes. We report a focal and temporal variant of the EAE model that results in immune‐mediated demyelination at a predictable time and location. Lewis rats were immunized with the extracellular domain (1‐125) of recombinant rat MOG in incomplete Freund's adjuvant (IFA) to induce a clinically silent humoral response. Vascular endothelial growth factor (VEGF) was then microinjected into the spinal cord to induce a transient, focal breakdown of the blood brain barrier (BBB). Clinical signs were apparent within 72 hours and began to resolve by day 21. The histopathology at the site of injection consisted of a focal region containing OX‐42+ cells, phagocytic cells with debris, extensive demyelination, and some lymphocyte infiltration. Neither intraspinal injection of PBS into immunized animals nor VEGF into animals treated with IFA alone resulted in clinical lesions. Thus, a transient, focal opening of the BBB with VEGF in animals with subclinical MOG immunization leads to a discrete inflammatory demyelinating lesion. This model may be useful for the study of transplanted myelin‐forming cells in a discrete inflammatory demyelinating lesion. © 2010 Wiley‐Liss, Inc.
Autophagy is activated by proteasomal inhibition and involved in aggresome clearance in cultured astrocytes
Authors: Jänen Sven B. , Chaachouay Hassan , Richter‐Landsberg Christiane
Published: July 2010

A common pathway underlying a variety of neurodegenerative disorders is the aggregation and deposition of misfolded proteins. Proteasomal inhibition has been demonstrated to promote the formation of intracellular inclusions. We have shown before that astrocytes respond to the treatment with the proteasome inhibitor MG‐132 by aggresome formation and cytoskeletal disturbances, but unlike oligodendrocytes do not die by apoptotic cell death and have the capability to recover. This study was undertaken to elucidate if the autophagy‐lysosomal pathway participates in the efficient recovery process in astrocytes and is modulated under conditions of proteasomal inhibition. The data show that the autophagic pathway was stimulated during a 24‐h treatment with the proteasome inhibitor MG‐132 in a time and concentration‐dependent manner. It remained at an elevated level throughout a 24‐h recovery period in the absence of MG‐132 and participates in the aggregate clearing process. In the presence of the specific inhibitor of macroautophagy, 3‐methyladenine, cell viability was impaired, aggregates were not as efficiently removed and HSP25, αB‐crystallin and ubiquitinated proteins remained in the insoluble protein fraction. LC3‐II positive puncta, indicative of autophagosomes, were formed abundantly in the cells after proteasome inhibition and were seen in close association with the aggregates. Hence, the ability of astrocytes to upregulate autophagic degradation might contribute to their resistance against proteasomal stress situations and act as a compensatory mechanism when the proteasome is impaired. © 2010 Wiley‐Liss, Inc.
Human remyelination promoting antibody inhibits apoptotic signaling and differentiation through Lyn kinase in primary rat oligodendrocytes
Authors: Watzlawik J. , Holicky E. , Edberg D. D. , Marks D. L. , Warrington A. E. , Wright B. R. , Pagano R. E. , Rodriguez M.
Published: July 2010

Purpose:

Human remyelination promoting IgM mAbs target oligodendrocytes (OLs) and function in animal models of multiple sclerosis (MS). However, their mechanism of action is unknown. This study seeks to identify the cellular mechanism of action of a recombinant human IgM on OL survival.

Methods:

Binding of rHIgM22 to the surface of rat OLs was studied by co‐localization with various markers. RHIgM22‐mediated effects on apoptotic signaling in OLs, differentiation markers, and signaling molecules were detected by Western blotting and immunoprecipitation.

Results:

RHIgM22 co‐localized with integrin β3 but not other integrin β‐chains in OLs. Downstream of integrin β3 we identified Src family kinase (SFK) Lyn as a key player of rHIgM22‐mediated actions in OLs. Lyn immunoprecipitated in a complex together with integrin αvβ3 and PDGFαR. Lyn expression was 9‐fold up‐regulated and Lyn activation was 3‐fold higher inrHIgM22‐treated OL cultures compared with controls. RHIgM22 inhibited apoptotic signaling by greater than 10‐fold reduction of caspase‐3 and capsase‐9 cleavage and reduced by 4‐fold expression of differentiation markers MBP and MOG in OLs. SFK inhibitors PP2 and SU6656 inhibited Lyn activity and restored caspase‐cleavage in OLs. A human IgM that did not promote remyelination and medium wereused as controls.

Conclusions:

rHIgM22 prevented apoptotic signaling andinhibited OL differentiation by Lyn implying thatIgM‐mediated remyelination is due toprotection of OPC and OLs rather than promotion of OPC differentiation. © 2010 Wiley‐Liss, Inc.