bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Rearrangements of Perchlorohexatrienes–Structures and Experimental and Theoretical Evaluation of Pathways to Isomerization and Cyclization
Authors: Detert Heiner , Lenoir Dieter , Zipse Hendrik
Published: January 2009

We have prepared trans‐ (1) and cis‐octachloro‐1,3,5‐hexatriene (2) by known routes and studied their thermal behavior experimentally and theoretically by ab initio calculations. The three double bonds in 1 and 2 are completely decoupled due to steric hindrance by the eight Cls, as indicated by calculations as well as the single‐crystal X‐ray structure of 1. The cis isomer 2 can be isomerized to the trans isomer 1 by heating it to 220–250 °C either neat or dissolved in high‐boiling solvents, leading to a roughly 2:1 mixture of trans and cis isomers. Calculations at several different levels of theory predict 1 and 2 to be isoenergetic within 2 kJ mol–1. Unimolecular cis/trans isomerization is predicted to occur through an unusual vinylcyclobutene intermediate 7, whose formation faces a barrier of more than 150 kJ mol–1, but whose stability is comparable to that of 1 and 2. The isomerization rate is strongly enhanced by the addition of small amounts of Br2 or Cl2 or by 3 and can be explained by a radical‐induced isomerization mechanism. The heating of trienes 1 and 2 to 250 °C leads to cyclization, yielding 71 % of the cyclopentene isomer 3. Compound 3 can be dechlorinated by treatment with copper powder to give fulvene derivative 4. Using flash vacuum pyrolysis, the thermal conversion of trienes 1 and 2 to hexachlorobenzene (5) occurs at higher temperatures between 600–1000 °C, likely via perchlorinated 1,3‐cyclohexadiene (6) as an intermediate. The elimination of molecular Cl2 from 3 and 6 requires very high activitation energies in agreement with calculations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis and Studies of a Super‐Structured Porphyrin Derivative – A Potential Building Block for CcO Mimic Models
Authors: Charalambidis Georgios , Ladomenou Kalliopi , Boitrel Bernard , Coutsolelos Athanassios G.
Published: January 2009

A novel porphyrin complex that contains an Fe porphyrin linked to a tridentate ligand where a Cu ion could be coordinated was synthesized. The molecule also incorporated a tyrosine mimic attached to the porphyrin ring via a urea bond and was fully characterized. We studied the action of dioxygen on several porphyrin derivatives electrochemically with a rotating ring‐disk electrode.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Concise Synthesis of R‐(–)‐Cicutoxin, a Natural 17‐Carbon Polyenyne
Authors: Gung Benjamin W. , Omollo Ann O.
Published: January 2009

A concise synthesis of the natural polyenyne R‐(–)‐cicutoxin (1) is described. After several trials, the successful synthesis commenced with three key fragments, R‐(–)‐1‐hexyn‐3‐ol (8), 1,4‐diiodo‐1,3‐butadiene (9), and THP‐protected 4,6‐heptadiyn‐1‐ol (6). Sonogashira coupling of compound 9 with acetylenes 6 and 8 gave the 17‐carbon frame, which upon regioselective reduction of a triple bond with Red‐Al and removal of the THP protecting group afforded the natural product in four linear steps. The triply convergent synthesis gave R‐(–)‐cicutoxin in 18 % overall yield. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Convenient Enantiospecific Route towards Bioactive Merosesquiterpenes by Cationic‐Resin‐Promoted Friedel–Crafts Alkylation with α,β‐Enones
Authors: Alvarez‐Manzaneda Enrique , Chahboun Rachid , Cabrera Eduardo , Alvarez Esteban , Haidour Ali , Ramos Jose Miguel , Alvarez‐Manzaneda Ramón , Tapia Rubén , Es‐Samti Hakima , Fernández Antonio , Barranco Inmaculada
Published: January 2009

An enantiospecific route towards bioactive merosesquiterpenes, based on the cationic‐resin‐promoted Friedel–Crafts alkylation of alkoxyarenes with an α,β‐unsaturated ketone, is reported. Reaction of ketone 11 with 3,4‐methylenedioxyphenol afforded the corresponding chromene. Treatment of 11 with protected phenol 20 gave aryl nordrimane ketone 21, a suitable intermediate in the synthesis of bioactive merosesquiterpenes and their 8‐epi derivatives. By utilizing this methodology, a formal synthesis of (+)‐puupehenone and other related metabolites, via triflate 25, is described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
AlCl3‐Promoted Facile E‐to‐Z Isomerization Route to (Z)‐2‐Methyl‐1‐buten‐1,4‐ylidene Synthons for Highly Efficient and Selective (Z)‐Isoprenoid Synthesis
Authors: Wang Guangwei , Negishi Ei‐ichi
Published: January 2009

Zr‐catalyzed methylalumination of 3‐butyn‐1‐ols followed by AlCl3‐promoted stereoisomerization at 50 °C for 6 h provides 4‐iodo‐3‐methyl‐3‐buten‐1‐ols 2b and 6 (≥98 % Z configuration) in 87 and 67 % yields, respectively. (Z)‐1,4‐Diiodo‐2‐methyl‐1‐butene (1b) obtainable by iodination of 2b is a valuable synthon for efficient and selective syntheses of (Z)‐alkene‐containing isoprenoids.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
New Electrochemical Method of Determining Blood and Blood Fractions Antioxidant Activity
Authors: Brainina Kh. Z. , Alyoshina L. V. , Gerasimova E. L. , Kazakov Ya. E. , Ivanova A. V. , Beykin Ya. B. , Belyaeva S. V. , Usatova T. I. , Khodos M. Ya.
Published: January 2009

Monitoring of oxidant/antioxidant state (antioxidant activity of blood and blood fractions) is essential for selecting and applying important therapy, to reduce and to prevent oxidative stress and irreversible changes in the body. The paper describes a new potentiometric method of determining antioxidant\oxidant activity (AOA/OA) of blood and blood fractions. The source of information is the electrode potential shift observed when the analyzed sample is introduced into the medium containing a mediator system. Mediator system, measuring electrode, method of blood hemolysis, anticoagulant are chosen. Comparison of the results obtained with the method proposed and the TAS (Randox) method confirms high self‐descriptiveness, and reliability of the results provided by potentiometric method. Relative standard deviation of analysis results, obtained with the use of MPA‐1 instrument and sensor proposed does not exceed 6–10%.
Electrochemical Renewal of Stationary Mercury Drop or Meniscus Electrodes
Authors: Polášková Petra , Novotný Ladislav , Ostatná Veronika , Paleček Emil
Published: January 2009

We show that a liquid mercury drop electrode surface can be electrochemically renewed without mechanical detachment of the drop. Voltammetric experiments with a mechanically renewed stationary (hanging) mercury drop or meniscus electrode (SME) and an electrochemically renewed SME are compared. The measurements were performed with two surface active organic depolarizers, i.e., 2‐aminoanthraquinone and dithiothreitol and surface inactive Cd(NO3)2. The results show that efficient purely electrochemical renewal of the electrode surface of SME for voltammetric purposes is possible.
The Effect of Ionic Liquid Covalent Bonding to Sol‐Gel Processed Film on Ion Accumulation and Transfer
Authors: Lesniewski Adam , Jönsson‐Niedziolka Martin , Niedziolka‐Jönsson Joanna , Rizzi Cécile , Gaillon Laurent , Opallo Marcin
Published: January 2009

Accumulation of electroactive anions into a silicate film with covalently bonded room temperature ionic liquid film deposited on an indium tin oxide electrode was studied and compared with an electrode modified with an unconfined room temperature ionic liquid. A thin film containing imidazolium cationic groups was obtained by sol‐gel processing of the ionic liquid precursor 1‐methyl‐3‐(3‐trimethoxysilylpropyl)imidazolium bis(trifluoromethylsulfonyl)imide together with tetramethylorthosilicate on the electrode surface. Profilometry shows that the obtained film is not smooth and its approximate thickness is above 1 μm. It is to some extent permeable for a neutral redox probe – 1,1′‐ferrocene dimethanol. However, it acts as a sponge for electroactive ions like Fe(CN)63−, Fe(CN)64− and IrCl63−. This effect can be traced by cyclic voltammetry down to a concentration equal to 10−7 mol dm−3. Some accumulation of the redox active ions also occurs at the electrode modified with the ionic liquid precursor, but the voltammetric signal is significantly smaller compare with the bare electrode. The electrochemical oxidation of the redox liquid t‐butyloferrocene deposited on silicate confined ionic liquid film is followed by the expulsion of the electrogenerated cation into an aqueous solution. On the other hand, the voltammetry obtained with the electrode modified with t‐butyloferrocene solution in the ionic liquid precursor exhibits anion sensitive voltammetry. This is explained by anion insertion into the unconfined ionic liquid deposit following t‐butylferricinium cation formation.
In vitro genotoxic assessment of xenobiotic diacylglycerols in an in vitro micronucleus assay
Authors: Kayani Mahmood A. , Parry James M. , Vickery Susan , Dodds Peter F.
Published: January 2009

Xenobiotic diacylglycerols (DG) may induce pathological disorders by causing abnormal chromosomal segregation, which could be aneuploid. In this study, seven xenobiotic‐diacylglycerols (four of drug origin and three of pesticide origin) were evaluated for their ability to induce aneuploidy in mammalian cultures using in vitro cytokinesis blocked micronucleus (CBMN) assay coupled with kinetochore labeling and interphase fluorescent in situ hybridization. Out of seven xeno‐DGs, two (ibuprofen‐DG and fenbufen‐DG) induced statistically significant (P < 0.001) and dose‐dependent increase in micronucleus induction, but this apparent micronucleus induction was very weak in case of fenbufen‐DG. These MN were produced predominantly by aneugenic and clastogenic mechanisms, respectively, confirmed by immunofluorescent labeling of kinetochores. Fluorescent in situ hybridization analysis revealed that ibuprofen‐DG induced significantly higher nondisjunction for chromosomes 10, 17, and 18. Other xenobiotic diacylglycerols (indomethacin‐DG, salicylic acid‐DG, 4‐(2‐methyl‐4‐chlorophenoxy) butanoic acid‐DG (MCPB‐DG), 2‐(2‐methyl‐4‐chlorophenoxy) propanoic acid‐DG (MCPP‐DG) and 2‐(4‐dichlorophenoxy)‐butanoic acid‐DG (2,4 DB‐DG) did not induce micronuclei, but the concentrations tested did not reach levels that caused the marked growth suppression typically required for testing for regulatory testing purposes. However, the levels of growth suppression achieved were similar to that seen with ibuprofen‐DG, which was positive. This study shows that xeno‐DGs, which have been neglected in the past for their possible link to any pathological disorders, need serious assessment of their mutagenic potential. Environ. Mal. Mutagen. 2009. © 2009 Wiley‐Liss, Inc.
The functional neuroanatomy of geriatric depression
Authors: Smith Gwenn S. , Kramer Elisse , Ma Yilong , Kingsley Peter , Dhawan Vijay , Chaly Thomas , Eidelberg David
Published: January 2009

Objective

Positron Emission Tomography (PET) studies of cerebral glucose metabolism have demonstrated sensitivity in evaluating the functional neuroanatomy of treatment response variability in depression, as well as in the early detection of functional changes associated with incipient cognitive decline. The evaluation of cerebral glucose metabolism in late life depression may have implications for understanding treatment response variability, as well as evaluating the neurobiological basis of depression in late life as a risk factor for dementia.

Methods

Sixteen patients with geriatric depression and 13 comparison subjects underwent resting PET studies of cerebral glucose metabolism, as well as magnetic resonance (MR) imaging scans to evaluate brain structure.

Results

Cerebral glucose metabolism was elevated in geriatric depressed patients relative to comparison subjects in anterior (right and left superior frontal gyrus) and posterior (precuneus, inferior parietal lobule) cortical regions. Cerebral atrophy (increased cerebrospinal fluid [CSF] and decreased grey and white matter volumes) were observed in some of these regions, as well. Regional cerebral metabolism was positively correlated with severity of depression and anxiety symptoms.

Conclusions

In contrast to decreased metabolism observed in normal aging and neurodegenerative conditions such as Alzheimer's disease, cortical glucose metabolism was increased in geriatric depressed patients relative to demographically matched controls, particularly in brain regions in which cerebral atrophy was observed, which may represent a compensatory response. Copyright © 2009 John Wiley & Sons, Ltd.
Photoinduced isomerization of allyl alcohols to carbonyl compounds using dendrimer disulfide as catalyst
Authors: Tsuboi Takaaki , Takaguchi Yutaka , Tsuboi Sadao
Published: January 2009

Allyl alcohols were isomerized to carbonyl compounds using diphenyl disulfide derivatives upon photoirradiation. Especially, dendrimer disulfide catalyzed the isomerization of allyl alcohols. Photoinduced isomerization in water was also succeeded by the use of water‐soluble dendrimer disulfide. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:1–11, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20504
Novel synthesis of N,N′‐dialkyl cyclic ureas using sulfur‐assisted carbonylation and oxidation
Authors: Mizuno Takumi , Nakai Takeo , Mihara Masatoshi
Published: January 2009

The first example of cyclic urea synthesis from secondary amines by the use of sulfur‐assisted carbonylation and oxidation was established. By combined sulfur‐assisted carbonylation of secondary α,ω‐diamines under an ambient pressure of carbon monoxide at 20°C with oxidation by molecular oxygen (0.1 MPa, 20°C), a facile synthetic method for N,N′‐dialkyl cyclic ureas including 1,3‐dimethyl‐2‐imidazolidinone was developed. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:64–68, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20508
The comparative roles of home and host supervisors in the expatriate experience
Authors: Benson George S. , Pattie Marshall
Published: January 2009

This study investigates the impact of home and host supervisors on expatriate success. Using survey and archival data on 206 expatriates of a large U.S. professional services firm, we hypothesize that high‐quality leader‐member exchange (LMX) relationships with home and host supervisors have different outcomes. Relationships with host‐country supervisors have greater influence on in‐country and short‐term outcomes, including adjustment and intentions to complete the assignment. Home‐country supervisors, on the other hand, have a greater influence over expatriates' subjective fit with their jobs and longer‐term perceptions of how the overseas assignment will impact their career. Using a separate survey of home and host supervisors at the same firm, we found that one reason that home and host supervisors infl uence expatriates differently may be because home supervisors are more likely to see professional development as a goal for expatriate assignments. © 2009 Wiley Periodicals, Inc.
Expatriate practices in German, Japanese, U.K., and U.S. multinational companies: A comparative survey of changes
Authors: Tungli Zsuzsanna , Peiperl Maury
Published: January 2009

In this article we present expatriate management policies and practices of 136 large multinational companies (MNCs) based in four different countries: Germany, Japan, the United Kingdom, and the United States. The findings we focus on include staffing, selection, training, and success. By analyzing our own results as well as comparing them to previous findings, we examine the changes in expatriate practices over time. In the managerial and research implications sections, we share additional findings and our thoughts about future issues and trends in expatriation. © 2009 Wiley Periodicals, Inc.
Evaluation of FEM electric field analysis using the electric properties of giant unilamellar vesicles (GUV) and Jurkat cells measured by electrorotation spectroscopy: Introduction of cryo‐ and lyoprotectants by electrofusion of GUVs and living cells
Authors: Shirakashi Ryo , Reuss Randolph , Schulz Alexander , Sukhorukov Vladimir L. , Zimmermann Ulrich
Published: January 2009

Electrofusion of giant unilamellar vesicles (GUVs) and living cells is a gentle method for delivering membrane impermeable cryo‐/lyo‐protective molecules into living cells for cryo‐/lyopreservation. In this method, an optimal length and strength of an electric pulse are required to initiate GUV‐cell fusion. Calculating the electric field by the finite element method (FEM) might be a powerful analytical method for prediction of the optimal pulse length and strength of a deformed and adhered GUV‐cell. The objective of this study is to clarify whether an FEM model of a pulsed GUV or cell could be applicable for prediction of its electric field, especially the change of membrane potential. First, electric properties of GUVs and Jurkat cells were derived from electrorotation spectra with a dipole approximation model. Secondly, the electric field and the membrane potential of a single GUV or cell after applying a stepwise electric field were calculated by an FEM model using the measured electric properties. At the first stage after applying a step electric field, the calculated membrane potential by the FEM model shows good agreement with the membrane potential derived from the dipole approximation model. After complete relaxation of the electric field, the calculated membrane potential of the FEM model is lower than that of the dipole approximation model. This might be because both models do not take into account the effects of electric double layers on both sides of the membrane. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20242
Metazoan origins of DNA replication: Regulation through dynamic chromatin structure
Authors: Rampakakis E. , Arvanitis D.N. , Di Paola D. , Zannis‐Hadjopoulos M.
Published: January 2009

DNA replication in eukaryotes is initiated at multiple replication origins distributed over the entire genome, which are normally activated once per cell cycle. Due to the complexity of the metazoan genome, the study of metazoan replication origins and their activity profiles has been less advanced than in simpler genome systems. DNA replication in eukaryotes involves many protein–protein and protein–DNA interactions, occurring in multiple stages. As in prokaryotes, control over the timing and frequency of initiation is exerted at the initiation site. A prerequisite for understanding the regulatory mechanisms of eukaryotic DNA replication is the identification and characterization of the cis‐acting sequences that serve as replication origins and the trans‐acting factors (proteins) that interact with them. Furthermore, in order to understand how DNA replication may become deregulated in malignant cells, the distinguishing features between normal and malignant origins of DNA replication as well as the proteins that interact with them must be determined. Based on advances that were made using simple genome model systems, several proteins involved in DNA replication have been identified. This review summarizes the current findings about metazoan origins of DNA replication and their interacting proteins as well as the role of chromatin structure in their regulation. Furthermore, progress in origin identification and isolation procedures as well as potential mechanisms to inhibit their activation in cancer development and progression are discussed. J. Cell. Biochem. 106: 512–520, 2009. © 2009 Wiley‐Liss, Inc.
Preparation and characterization of poly(lactic‐co‐glycolic acid) microparticles containing DNA molecules encoding a malaria vaccine candidate
Authors: Liu Shan , Danquah Michael K. , Ho Jenny , Ma Charles , Wang Lina , Coppel Ross , Forde Gareth M.
Published: January 2009

BACKGROUND: A novel ultrasonic atomization approach for the formulation of biodegradable poly(lactic‐co‐glycolic acid) (PLGA) microparticles of a malaria DNA vaccine is presented. A 40 kHz ultrasonic atomization device was used to create the microparticles from a feedstock containing 5 volumes of 0.5% w/v PLGA in acetone and 1 volume of condensed DNA which was fed at a flow rate of 18 ml h−1. The plasmid DNA vectors encoding a malaria protein were condensed with a cationic polymer before atomization.

RESULTS: High levels of gene expression in vitro were observed in COS‐7 cells transfected with condensed DNA at a nitrogen to phosphate (N/P) ratio of 10. At this N/P ratio, the condensed DNA exhibited a monodispersed nanoparticle size (Z‐average diameter of 60.8 nm) and a highly positive zeta potential of 38.8 mV. The microparticle formulations of malaria DNA vaccine were quality assessed and it was shown that the microparticles displayed high encapsulation efficiencies between 82–96% and a narrow size distribution in the range of 0.8–1.9 µm. In vitro release profile revealed that approximately 82% of the DNA was released within 30 days via a predominantly diffusion controlled mass transfer system.

CONCLUSIONS: This ultrasonic atomization technique showed excellent particle size reproducibility and displayed potential as an industrially viable approach for the formulation of controlled release particles. Copyright © 2009 Society of Chemical Industry
Pseudoaneurysm of the posterior circumflex humeral artery diagnosed by sonography
Authors: Damgaard Bodil , Court‐Payen Michel , Larsen Lone , Lausten Gunnar
Published: January 2009

We report a rare case of a pseudoaneurysm of the posterior circumflex humeral artery, probably related to a steroid injection in the shoulder 3 months earlier. The clinical presentation was atypical and the location not previously described in the literature. The patient was referred with a painless, nonpulsatile mass in the posterior shoulder region and was suspected of a malignant soft‐tissue tumor. Sonography, including power Doppler imaging, demonstrated a pseudoaneurysm, with the intralesional blood‐filled cavity developed from the posterior circumflex humeral artery. The diagnosis was confirmed by pathologic examination of the surgical specimen. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Cardiac amyloidosis in a patient with multiple myeloma: A case report and review of literature
Authors: Sedaghat David , Zakir Ramzan M. , Choe Jin , Klapholz Marc , Saric Muhamed
Published: January 2009

We report a case of a 52‐year‐old man with multiple myeloma and rapidly progressive heart failure who died unexpectedly from a probable arrhythmia. Postmortem examination revealed infiltrative amyloid cardiomyopathy, a rare cause of predominantly diastolic myocardial disease. Cardiac amyloidosis should be considered in any patient presenting with congestive heart failure, preserved systolic function, and a discrepancy between a low QRS voltage on electrocardiography and an apparent left ventricular hypertrophy on sonogram. The pattern of left ventricular diastolic dysfunction changes during the course of amyloidosis and the classically described restrictive physiology occurs only in advanced stages of the disease. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Reduction of type IIb myosin and IIB fibers in tibialis anterior muscle of mini‐muscle mice from high‐activity lines
Authors: Bilodeau Geneviève M. , Guderley Helga , Joanisse Denis R. , Garland Theodore
Published: January 2009

Selective breeding of laboratory house mice (Mus domesticus) for high voluntary wheel running has generated four replicate lines that show an almost threefold increase in daily wheel‐running distances as compared with four nonselected control lines. An unusual hindlimb “mini‐muscle” phenotype (small muscles, increased mitochondrial enzyme levels, disorganized fiber distribution) has increased in frequency in two of the four replicate selected lines. The gene of major effect that accounts for this phenotype is an autosomal recessive that has been mapped to a 2.6335 Mb interval on MMU11, but not yet identified. This study examined the tibialis anterior muscle to determine whether changes in muscle fiber types could explain such modifications in muscle size and properties. Although selected and control lines did not exhibit systematic differences in the fiber types present in the tibialis anterior muscle, as assessed by electrophoresis of myosin heavy chains (MHC) and by histochemistry, mini‐muscle mice lacked type IIB fibers and the corresponding MHCs. Mini‐muscle tibialis show increased activities of hexokinase and citrate synthase compared with the normally sized muscles, likely the result of the modified fiber types in the muscle. The mini‐muscle phenotype is the major means through which selective breeding for high wheel running has modified the functional capacities of the hindlimb muscles, as normally sized tibialis anterior muscles from control and selected lines did not show general differences in their enzymatic capacities, MHC profiles or fiber type composition, with the exception of an elevated hexokinase activity and a reduced GPa activity in the selected lines. J. Exp. Zool. 311A:189–198, 2009. © 2009 Wiley‐Liss, Inc.
Design and evaluation of thin and flexible theophylline imprinted polymer membrane materials
Authors: Hillberg Anna L. , Brain Keith R. , Allender Chris J.
Published: January 2009

The aim of this work was to produce a thin, flexible and diffusion able molecularly imprinted polymeric matrix with good template accessibility. Membranes were prepared using a non‐covalent molecular imprinting approach and their physical characteristics and binding capabilities investigated. Two materials were used, a poly(tri‐ethyleneglycol dimethyacrylate‐co‐methyl methacrylate‐co‐methacrylic acid) copolymer containing 14% cross‐linker and a monomer (g) to porogen (ml) ratio of 1:0.5 (A), and a blend of poly(TEGMA‐co‐MAA) and polyurethane (B). The polyurethane was added to improve membrane flexiblity and stability. The polymers were characterized using AFM, SEM and nitrogen adsorption, whilst binding was evaluated using batch‐rebinding studies. For all membranes the specific surface area was low (<10 m2/g). MIP (A) films were shown to bind specifically at low concentrations but specific binding was masked by non‐specific interactions at elevated concentrations. Selectivity studies confirmed specificity at low concentrations. KD approximations confirmed a difference in the population of binding sites within NIP and MIP films. The data also indicated that at low concentrations the ligand‐occupied binding site population approached homogeneity. Scanning electron microscopy images of membrane (B) revealed a complex multi‐layered system, however these membranes did not demonstrate specificity for the template. The results described here demonstrate how the fundamental parameters of a non‐covalent molecularly imprinted system can be successfully modified in order to generate flexible and physically tolerant molecularly imprinted thin films. Copyright © 2009 John Wiley & Sons, Ltd.
China's snow disaster in 2008, who is the principal player?
Authors: Hui Gao
Published: January 2009

The unprecedented snow disaster in January 2008 brought serious human and economic losses to China. It has been suggested that the La Nina event is the principal cause. But analysis indicates that in December 2007, the circulation patterns in the tropical regions are quite similar with those in January 2008. In contrast large differences existed at high latitudes, especially the Siberia high (SH) and the north polar vortex (NPV). The differences can also be found between other extreme heavy and light snow years. In the extreme heavy (light) snow years, the SH is stronger (weaker) and the NPV is deeper (shallower). But these extreme snow events don't correspond to ENSO events well. Statistical results also indicate that both the SH and the NPV are independent of ENSO. So, rather than the La Nina event, the abnormal circulations at the high latitudes may play a more crucial role in making this snow disaster. Copyright © 2009 Royal Meteorological Society
Apparent electrical conductivity integrated from layered soil profiles
Authors: Bänninger Dominik , Wunderli Hans , Flühler Hannes
Published: January 2009

Time domain reflectometry (TDR) trace analysis aims at extracting the water content profile along TDR probes. This can be done by applying a TDR forward solver inversely. Thus, TDR‐trace inversion is basically an optimization problem. As in any optimization procedure, it is worthwhile to include as much a priori information as possible about the problem to be solved. In this study, we discuss the feasibility to use the apparent electrical conductivity as constraint for the TDR inversion. The resistors‐in‐parallel circuit can be used to integrate a multislice soil model to obtain the apparent electrical conductivity. We apply additionally Archie's law to link the water content of a particular slice with its electrical conductivity. We compare the results from this approach with measured TDR traces and show that the problem is solved exactly. Finally, we address the thin‐layer issue because thin layers with a high permittivity contrast result in a delay of the run time of an electromagnetic pulse. We test numerically whether a similar behavior can be observed for a thin layered electrical conductivity profile. Our results show that the thickness of the soil layer with respect to electrical conductivity has no effect on the apparent electrical conductivity. We conclude that the apparent electrical conductivity is appropriate as boundary condition in TDR inversion as long as a procedure is known to convert the water content of a slice to its electrical conductivity
Determination of anti‐malaria agent chloroquine using single drop liquid‐liquid‐liquid microextraction
Authors: Daneshfar Ali , Khezeli Tahere , Manafi Mohamad H.
Published: January 2009

A simple, sensitive, and inexpensive single drop liquid‐liquid‐liquid microextraction combined with isocratic RP‐HPLC and UV detection was developed for the determination of anti‐malaria drug, chloroquine. The target compound was extracted from alkaline aqueous sample solution (adjusted to 0.5 mol/L sodium hydroxide) through a thin layer of organic solvent membrane and back‐extracted to an acidic acceptor drop (adjusted to 0.02 mol/L phosphoric acid) suspended on the tip of a 25 μL HPLC syringe in the organic layer. This syringe was also used for direct injection after extraction. The linear range was 1–200 μg/L. The LOD and LOQ were 0.3 and 1.0 μg/L, respectively. Intra‐and inter‐day precisions were less than 2.0 and 2.3%, respectively. The real samples were successfully analyzed using the proposed method. The recoveries of spiked samples were more than 94.6%.
Improved protein separation by microchip isoelectric focusing with stepwise gradient of electric field strength
Authors: Cong Yongzheng , Liang Yu , Zhang Lihua , Zhang Weibing , Zhang Yukui
Published: January 2009

A stepwise gradient of electric field strength was proposed for microchip IEF‐based protein separation, by which after focusing at low voltages, IEF was performed by applying higher separation voltages step‐by‐step. A linear relationship between the focusing time and the inverse of the electric field strength was found. In addition, the conductivity of an established pH gradient showed a negative but nonlinear correlation with the applied voltage. Based on the above‐mentioned results, a stepwise gradient of electric field strength, ranging from 160 to 1500 V/cm was applied in the separation of proteins extracted from Escherichia coli in a straight glass microchip channel permanently coated by polyacrylamide. Compared to the conventional separation performed under a constant field strength of 750 V/cm, the increased stepwise gradient of electric field strength resulted in improved resolution and decreased focusing time, while without the negative effects of Joule heat for protein separation. All these results demonstrated that such a method might be of great significance to achieve high resolution and high‐throughput analysis of complex protein samples for microchip IEF.
Effects of long‐acting beta adrenergic agonists on vocal fold ion transport
Authors: Sivasankar Mahalakshmi , Blazer‐Yost Bonnie
Published: January 2009

Objectives:

Inhaled medications prescribed for the hypersensitive airway typically combine corticosteroids and long‐acting β2 adrenergic agonists (LABAs). The phonatory side effects of these combination treatments are widely recognized. However, there is limited understanding of the physiological changes induced by these medications that underlie the phonatory side effects. The objective of this study was to investigate the distinct effects of corticosteroids and LABAs on vocal fold mucosal physiology. Understanding the physiological changes to the vocal folds after corticosteroid and LABA treatments is necessary to prevent the prevalent vocal decrement associated with these medications.

Study Design:

Experimental in vitro design with treatment and control groups.

Methods:

Native porcine vocal fold mucosae (N = 38) were exposed to corticosteroid or LABA treatments. Ion transport was measured continuously at baseline and after treatment. To quantify the nature of ion transport, vocal folds were also treated with chloride and sodium channel inhibitors.

Results:

Corticosteroid treatment did not alter ion transport. Conversely, exposure to LABAs significantly increased ion transport. This increase in ion transport was transient, observed immediately after treatment in all tissue and associated with increased chloride secretion.

Conclusions:

The distinct effects of corticosteroids and LABAs on vocal fold physiology have not been examined to date. This study demonstrates that short‐term treatment with LABAs, but not corticosteroids, significantly increases ion transport. These findings suggest that one underlying physiological mechanism for phonatory changes associated with inhaled treatments may be related to acute alterations in vocal fold ion transport and surface hydration. Laryngoscope, 2009
Significant correlation between spleen volume and thrombocytopenia in liver transplant patients: A concept for predicting persistent thrombocytopenia
Authors: Ohira Masahiro , Ishifuro Minoru , Ide Kentaro , Irei Toshimitsu , Tashiro Hirotaka , Itamoto Toshiyuki , Ito Katsuhide , Chayama Kazuaki , Asahara Toshimasa , Ohdan Hideki
Published: January 2009

Interferon (IFN) therapy with or without ribavirin treatment is well established as a standard antiviral treatment for hepatitis C virus (HCV)–infected patients. However, susceptibility to thrombocytopenia is a major obstacle for initiating or continuing this therapy, particularly in liver transplant (LTx) recipients with HCV. Studies have reported that splenectomy performed concurrently with LTx is a feasible strategy for conditioning patients for anti-HCV IFN therapy. However, the relationship between the severity of splenomegaly and alterations in the blood cytopenia in LTx recipients remains to be clarified. Here, we analyzed the relationship between spleen volume (SV) and thrombocytopenia in 45 patients who underwent LTx at Hiroshima University Hospital. The extent of pre-LTx splenomegaly [the SV to body surface area (BSA) ratio in an individual] was inversely correlated with both the post-LTx white blood cell count and platelet (PLT) count (P < 0.001). Furthermore, the PLT count of patients with thrombocytopenia (PLT count ≤ 5 × 104/mm3) increased significantly in the group without splenomegaly (SV/BSA value < 400) versus that in the group with splenomegaly (P = 0.005). Thus, if both splenomegaly and thrombocytopenia coexist (PLT count ≤ 5 × 104/mm3 and SV/BSA value ≥ 400), persistent thrombocytopenia is predictable after LTx.
Addition of adult-to-adult living donation to liver transplant programs improves survival but at an increased cost
Authors: Northup Patrick G. , Abecassis Michael M. , Englesbe Michael J. , Emond Jean C. , Lee Vanessa D. , Stukenborg George J. , Tong Lan , Berg Carl L.
Published: January 2009

Using outcomes data from the Adult-to-Adult Living Donor Liver Transplantation Cohort Study, we performed a cost-effectiveness analysis exploring the costs and benefits of living donor liver transplantation (LDLT). A multistage Markov decision analysis model was developed with treatment, including medical management only (strategy 1), waiting list with possible deceased donor liver transplantation (DDLT; strategy 2), and waiting list with possible LDLT or DDLT (strategy 3) over 10 years. Decompensated cirrhosis with medical management offered survival of 2.0 quality-adjusted life years (QALYs) while costing an average of $65,068, waiting list with possible DDLT offered 4.4-QALY survival and a mean cost of $151,613, and waiting list with possible DDLT or LDLT offered 4.9-QALY survival and a mean cost of $208,149. Strategy 2 had an incremental cost-effectiveness ratio (ICER) of $35,976 over strategy 1, whereas strategy 3 produced an ICER of $106,788 over strategy 2. On average, strategy 3 cost $47,693 more per QALY than strategy 1. Both DDLT and LDLT were cost-effective compared to medical management of cirrhosis over our 10-year study period. The addition of LDLT to a standard waiting list DDLT program is effective at improving recipient survival and preventing waiting list deaths but at a greater cost.
Treatment of hepatitis C in liver transplant recipients
Authors: Gordon Fredric D. , Kwo Paul , Vargas Hugo E.
Published: January 2009

Recurrent hepatitis C after liver transplantation is a universal phenomenon. Graft reinfection occurs rapidly; once it is established, allograft cirrhosis and decompensation rapidly ensue in many patients. Treatment with pegylated interferon plus ribavirin is the standard of care among nontransplant patients with hepatitis C; however, the applicability of these therapies in liver transplant patients is severely limited. Before transplantation, many patients are simply too ill to endure the long treatment duration necessary to achieve viral eradication; thus, treatment-related toxicity is a frequent barrier to success. Clinical trials in the pretransplantation population have yielded poor outcomes, with sustained virologic response rates only as high as 25%. Early after transplantation, treatment may be initiated prophylactically, or it may be initiated therapeutically in patients with evidence of recurrent disease. In small studies, prophylactic therapy has been associated with sustained virologic response rates lower than 20%, whereas in therapeutic intervention studies, sustained virologic response rates have ranged from 20% to 37%. In the setting of therapeutic intervention, preliminary indications suggest that rapid and early virologic response may become important clinical tools enabling the early identification of patients likely to respond to treatment. Two important clinical trials, PHOENIX (Pegasys and Copegus Administered After Liver Transplantation for Hepatitis C) in the prophylactic setting and PROTECT (Pegylated Interferon Alfa-2b and Ribavirin After Orthotopic Liver Transplantation: Efficacy and Safety in Hepatitis C Recurrence Therapy) in the therapeutic setting, are under way and should further advance our understanding of the management of hepatitis C in patients undergoing liver transplantation.
Chelation therapy for neurodegenerative diseases
Authors: Bolognin Silvia , Drago Denise , Messori Luigi , Zatta Paolo
Published: January 2009

Mounting evidence suggests a central role for transition biometals in the etiopathogenesis of neurodegenerative diseases (ND). Indeed, while studying the molecular basis for this heterogeneous group of diseases, it has become increasingly evident that biometals and nonphysiological Al are often involved in pathology onset and progression, either by affecting the conformation of specific proteins or by exacerbating local oxidative stress. The apparently critical role played by metal dishomeostasis in ND makes chelation therapy an attractive pharmacological option. However, classical metal chelation approaches, relying on potent metal ligands, turned out to be successful only in those rare cases where exceptional brain metal accumulation occurs due to specific defects in metal metabolism. In contrast, metal‐targeted approaches using ligand of intermediate strength seem to be more appropriate in fighting the major ND, although their benefits are still questioned. We report here a survey of recent evidences supporting the use of a variety of metal ligands, and even functionalized nanoparticles, for the treatment of the most common ND. The beneficial neuropharmacological actions of metal‐targeted agents most likely arise from local metal redistribution rather than from massive metal removal. The perspectives for the development of new effective agents against ND are critically discussed. © 2009 Wiley Periodicals, Inc. Med Res Rev
A practical method for computing the largest M‐eigenvalue of a fourth‐order partially symmetric tensor
Authors: Wang Yiju , Qi Liqun , Zhang Xinzhen
Published: January 2009

In this paper, we consider a bi‐quadratic homogeneous polynomial optimization problem over two unit spheres arising in nonlinear elastic material analysis and in entanglement studies in quantum physics. The problem is equivalent to computing the largest M‐eigenvalue of a fourth‐order tensor. To solve the problem, we propose a practical method whose validity is guaranteed theoretically. To make the sequence generated by the method converge to a good solution of the problem, we also develop an initialization scheme. The given numerical experiments show the effectiveness of the proposed method. Copyright © 2009 John Wiley & Sons, Ltd.
Isothermal degradation of poly(3‐hydroxybutyrate)/organically modified montmorillonite nanocomposites
Authors: Erceg Matko , Kovačić Tonka , Perinović Sanja
Published: January 2009

Polymer nanocomposites consisted of biodegradable poly(3‐hydroxybutyrate) (PHB) and organically modified montmorillonite Cloisite25A (OMMT), prepared by the solution‐casting method, were isothermally degraded for 120 min at 230, 235, 240, and 245°C in the nitrogen atmosphere. The addition of OMMT increases the thermal stability of PHB, and the most pronounced effect has the addition of 7 wt% of OMMT. Kinetic analysis was performed using reduced time plots and model‐free isoconversional methods. The empirical kinetic triplets (E, A, and g(α)) for the isothermal degradation of pure PHB and PHB/OMMT nanocomposites were determined. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Evaluation of embedded optical fiber sensors in composites: EFPI sensor response to fatigue loading
Authors: Etches J.A. , Fernando G.F.
Published: January 2009

Extrinsic Fiber Fabry‐Perot Interferometric (EFPI) sensors were fabricated and embedded within a 16‐layer cross‐ply composite. The composites with and without the embedded EFPI sensors were subjected to tension/compression loading. The presence of the embedded sensor was not found to have adverse effect on the tension/compression fatigue properties. However, the performance of the EFPI sensor was found to degrade with fatigue cycles, with the introduction of a compressive element in the loading regime; samples were tested using stress ratios of −1, −2.5, and −3. Although the reasons for this observed degradation in the response of the sensor to applied strain is not known at present, it is speculated that this may be due to debonding of the key components of the sensor. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Properties and strain hardening character of polyethylene terephthalate containing Isosorbide
Authors: Gohil Ramesh M.
Published: January 2009

Polyethylene terephthalate containing Isosorbide (PEIT) polymers made from renewable corn‐derived Isosorbide monomer exhibit a wide range of glass transition temperatures (80–180°C) and are therefore able to be used in many applications. Stress–strain curves for high Isosorbide content copolymers show strain softening, which impairs the molecular orientation during orientation of films and bottles. It is therefore necessary to find ways to modify deformation behavior of PEIT copolymers. Deformation characteristics of PEIT and other polyesters have been evaluated to define stretching parameters and necessary composition for making oriented bottles for hot fill applications. In the presence of polymeric nucleating agents, (polymeric ionomers or polyesters containing sodium ions), strain‐hardening parameters become almost temperature‐ independent below solid state deformation temperature of 125°C. We developed a methodology to achieve molecular orientation comparable with films and articles made by conventional processing of poly(ethylene terephthalate), PET. Polyesters containing sodium ions are efficient nucleating agents for PEIT, and their required concentration is dependent on deformation temperature. Both strain hardening and stress at 250% strain depend on the concentration of nucleating agents and deformation temperatures. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Effect of cellulose concentration in NMMO·H2O solution on prediction of MW and MWD of cellulose using a rheology‐based method
Authors: Zhang Huiru , Liu Xiaoyun , Li Dongshuang , Li Rongxian
Published: January 2009

Prediction of molecular weight (MW) and molecular weight distribution (MWD) of cellulose by means of a rheology‐based method is developed. In this method, the effect of cellulose concentration in N‐methlymorpholine‐N‐oxide monohydrate (NMMO·H2O) solution on predicting results is discussed. It is shown that there is no significant effect of cellulose concentration on predicting results when the cellulose concentration in NMMO·H2O solution is high enough. Meanwhile, the obtained results are compared with those of gel permeation chromatograghy (GPC) method. The comparison shows that the calculated peak MW, polydispersity index (PDI) and MWD curves have the same trends. Consequently, it may be feasible to compare the MW and MWD of cellulose by using the rheology‐based method. In addition, the rheology‐based method is simple and fast. Therefore it is a useful and easy way to analyze the MW and MWD of cellulose in the fiber industry. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Strategies for improving graft degree of urethane derivative of 2‐hydroxymethyl methacrylate grafted onto LDPE
Authors: Ding Shenglong , Liu Mingzhu
Published: January 2009

A novel monomer, 2‐methyl‐acrylic acid 2‐(3‐isocyanato‐2‐methyl‐phenyl carbamoyloxy)‐ethyl ester (HT), was synthesized by the reaction of 2‐hydroxymethyl methacrylate with toluene diisocyanate. The influences of solvents, temperature and catalyst, dibutyl tin dilaurate on the total yield of HT were investigated and theoptimum synthesis conditions were obtained. The obtained monomer was then used to modify low density polyethylene (LDPE) in the Haake Rheomix 600P via melt grafting copolymerization. The modified LDPE was characterized by Fourier transform infrared. During the grafting process, single‐step and two‐step procedures were compared and the results showed that the two‐step procedure was more favorable. In a two‐step procedure, the influences of melting temperatures, monomer amount, and ethylene vinyl acetate copolymer (EVA, Mn = 800–1200) on the graft degree were also investigated. The investigation confirmed that EVA acting as a dispersant could enhance the dispersion of the monomer and improve graft degree significantly, and net value of increased graft degree was about 1.5%. The better dispersion of HT in the matrix of LDPE was confirmed via scanning electron microscope after adding EVA to the system. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers