bluuebunny/crossref_metadata_2025 huggingface dataset:
Field Measurement of Soil Surface Chemical Transport Properties for Comparison of Management Zones
Authors: Heitman J.L. , Gaur A. , Horton R. , Jaynes D. B. , Kaspar T. C.
Published: March 2007

Management of chemicals in soil is important, yet the complexity of field soils limits prediction of management effects on transport. To date, few methods have been available for field measurement of chemical transport properties, but a recently developed dripper–time domain reflectometry technique allows rapid collection of data for determining these properties. The objective of this work was to apply this technique for comparison of chemical transport properties for different soil management zones. Experiments were conducted comparing four interrow management zones: no‐till nontrafficked, no‐till trafficked, chisel plow nontrafficked, and chisel plow trafficked. Drip emitters were positioned at 12 locations in each zone and used to apply water followed by a step input of CaCl2 tracer solution. Breakthrough curves were measured via electrical conductivity with time domain reflectometry probes. The mobile–immobile model was fit to the breakthrough curves to determine chemical transport properties. Mean chemical transport properties were 0.34, 0.11 h−1, 10 cm h−1, 164 cm2 h−1, and 5 cm, for the immobile water fraction, mass exchange coefficient, average pore‐water velocity, mobile dispersion coefficient, and dispersivity, respectively. All five properties showed significant differences between management zones. Differences in mass exchange and mobile dispersion coefficients coincided with differences in tillage, while differences in mean pore water velocities coincided with differences in traffic. The immobile water fraction was largest for the no‐till nontrafficked zone. These results represent one of very few reports for field measurement of chemical transport properties and the first application of this approach for comparison of chemical transport properties across management zones.
BEING PROUD OF ONESELF AS A PERSON OR BEING PROUD OF ONE’S PHYSICAL APEARANCE: WHAT MATTERS FOR FEELING WELL IN ADOLESCENCE?
Authors: Seidah Amélie , Bouffard Thérèse
Published: March 2007

Among the numerous studies aimed at examining the link between appearance satisfaction and self-esteem at adolescence very few, except Zumpf and Harter (1989), have specifically examined the directionality of the relation. Hence, the first goal of this study was to examine the distribution
of adolescents, according to their gender and grade level, within each of the following two groups: those who acknowledge that the evaluation of their physical appearance precedes and determines their global self-esteem, and those who conversely believe that they must first be satisfied with
their global sense of self in order to be satisfied with their physical appearance. The second goal was to examine whether adolescents' perceived competence in various domains of daily life functioning differs according to how they value physical appearance. Participants were 1,362 adolescents
(540 boys and 822 girls) from the 7th, 9th and 11th grades. Overall, 35% of adolescents acknowledged that their perceived appearance determined their self-esteem, with boys and girls being proportionally distributed between the groups. Adolescents in the group more concerned with appearance
reported lower satisfaction with their physical appearance, lower self-esteem than others, and lower perceived competence in the scholastic and social domains.
Currarino syndrome shown by prenatal onset ventriculomegaly and spinal dysraphism
Authors: Crétolle C. , Sarnacki S. , Amiel J. , Geneviève D. , Encha‐Razavi F. , Zrelli S. , Zérah M. , Nihoul Fékété C. , Lyonnet S.
Published: March 2007

The most frequent cause of ventriculomegaly is spina bifida when associated with Arnold–Chiari type II malformation. We report on a prenatal diagnosis of severe ventriculomegaly in association with spinal dysraphism that was indicative of a Currarino syndrome (CS) due to a c.584delA, p.H195fsX28 truncated mutation within the HLXB9 gene. Physiopathology of the ventriculomegaly is discussed in reference to the fetopathological examination and CS embryopathology. In the present case, prognosis was poor and pregnancy termination was authorized. However, such a decision may be controversial in fetuses with less severe malformations on sonographic examination, since mutations in the HLXB9 gene can predict neither the severity nor the long‐term prognosis of the disease. Due to a lack of genotype–phenotype correlation and the broad variability of phenotype in heterozygotes, clinical and genetic investigations among relatives are mandatory in all HLXB9 gene mutation cases, to detect asymptomatic CS cases and to prevent the occurrence of severe complications. © 2007 Wiley‐Liss, Inc.
Mutations in GJB2, GJB6, and mitochondrial DNA are rare in African American and Caribbean Hispanic individuals with hearing impairment
Authors: Samanich Joy , Lowes Christina , Burk Robert , Shanske Sara , Lu J. , Shanske Alan , Morrow Bernice E.
Published: March 2007

Autosomal recessive nonsyndromic sensorineural hearing impairment (ARNSHI) comprises 80% of familial hearing loss cases. Approximately half result from mutations in the connexin 26 (Cx26) gene, GJB2, in Caucasian populations. Heterozygous mutations in GJB2 occasionally co‐occur with a deletion of part of GJB6 (connexin 30; Cx30). It is estimated that approximately 1% of deafness is maternally inherited, due to mutations in mitochondrial DNA (mtDNA). Few studies have focused on the frequency of mutations in connexins or mtDNA in African American (AA) and Caribbean Hispanic (CH) admixture populations. In this study, we performed bidirectional sequencing of the GJB2 gene and polymerase chain reaction (PCR) screening for the common GJB6 deletion, as well as PCR/RFLP analysis for three mutations in mtDNA (A1555G, A3243G, A7445G), in 109 predominantly simplex AA and CH individuals. Variations found were a 101T > C (M34T; 1/101 cases), 109G > A (V37I; 1/101), 35delG (mutation; 4/101, ¾ of non‐AA/CH ethnicity), 167delT (mutation; 1/101), 139G > T (mutation; E47X; 1/101 homozygote, consanguineous), −15C > T (1/101), 79G > A (V27I; 9/101), 380G > A (R127H; 4/101; Guyana, India, Pakistan ethnicity), 670A > C (Indeterminate; K224Q; 1/101), 503A > G (novel; K168R; 3/101) and 684C > A (novel; 1/101). All but one of the AA and CH patients had monoallelic variations. There were no hemizygous GJB6 deletions in those with monoallelic GJB2 variations. We also did not identify any patients with the three mutations in mtDNA. Bidirectional sequencing of the GJB2 gene was performed in 187 AA and Hispanic healthy individuals. Our results reveal that GJB2 mutations, GJB6 deletions, and mtDNA mutations may not be significant in these minority admixture populations. © 2007 Wiley‐Liss, Inc.
p75NTR gene and suicide attempts in young adults with a history of childhood‐onset mood disorder
Authors: McGregor S. , Strauss J. , Bulgin N. , De Luca V. , George C.J. , Kovacs M. , Kennedy J.L.
Published: March 2007

Recently, evidence has accumulated for the role of neurotrophic processes in mood disorders. Neurotrophins operate on receptors, one of which is the p75 neurotrophin receptor (p75NTR). We examined three p75NTR markers at the p75NTR gene, including a missense polymorphism that changes serine to leucine (S205L), for association with suicide attempt (SA) in 203 childhood‐onset mood disorder (COMD) cases. There was no difference between COMD suicide attempters and COMD non‐attempters with logistic regression models for any of the three markers. We also compared the three polymorphisms between 192 COMD cases and 192 matched healthy controls and found no significant differences between COMD and healthy controls. Our results do not support an association of the p75NTR S205L polymorphism with risk for COMD or SA in COMD. © 2007 Wiley‐Liss, Inc.
Association between cytochrome P450 (CYP) 2C19 polymorphisms and harm avoidance in Japanese
Authors: Yasui‐Furukori Norio , Kaneda Ayako , Iwashima Kumiko , Saito Manabu , Nakagami Taku , Tsuchimine Shoko , Kaneko Sunao
Published: March 2007

Polymorphic enzyme cytochrome P450 (CYP) 2C19 is expressed not only in the liver but also in the brain and mediates the biotransformation of 5‐hydroxytriptamine (5‐HT). We investigated possible association between genetic polymorphism of CYP2C19 and individual personality traits, possibly influenced by neurotransmitters. Mentally and physically healthy Japanese subjects were enrolled in this study (n = 352). Temperament and Character Inventory (TCI) and CYP2C19 genotyping were performed in all subjects. We detected CYP2C19*2 and *3 (http://www.imm.ki.se/CYPalleles/) using Amplichip CYP450 DNA tip. The number of genotypes classified as homozygous extensive metabolizer (EM), heterozygous EM, and poor metabolizer were 113, 181, and 58, respectively. Significant difference was found in TCI score in harm avoidance (HA; F = 3.138, P < 0.05). Post hoc analysis showed that TCI score in harm avoidance in homozygous EM was significantly lower than that in heterozygous EM (P < 0.05) or PM (P < 0.05). In sub‐item analyses, HA3 (shyness with strangers, P < 0.01) and HA1 (anticipatory worry, P < 0.05) of TCI scores were significantly different among CYP2C19 genotypes. Meanwhile, there were no differences in TCI scores of novelty seeking (NS; F = 0.350, n.s.), reward dependence (RD; F = 1.080, n.s.), or persistence (P; F = 0.786, n.s.) among CYP2C19 genotypes. This study demonstrated that a significant association between CYP2C19 activity and HA is present in Japanese. © 2007 Wiley‐Liss, Inc.
Clinical and imaging evidence of zolpidem effect in hypoxic encephalopathy
Authors: Brefel‐Courbon Christine , Payoux Pierre , Ory Fabierine , Sommet Agnes , Slaoui Tarik , Raboyeau Gaelle , Lemesle Beatrice , Puel Michele , Montastruc Jean‐Louis , Demonet Jean‐Francois , Cardebat Dominique
Published: March 2007

We conducted a randomized, double‐blind, placebo‐controlled, single‐patient (N = 1) trial to evaluate the efficacy of zolpidem in a 48‐year‐old woman with an akinetic mutism. Motor and cognitive examinations and functional imaging were performed. Acute administration of zolpidem markedly improved motor performance and neuropsychological status. Cerebral metabolism (18F‐fluorodeoxyglucose positron emission tomography) increased in postrolandic territories and in frontal cortex. Using the H215O positron emission tomography, we found a drug‐induced activation in the anterior cingulate and orbitofrontal cortices. Zolpidem induced a transient improvement in motor and cognitive performances. This paradoxical effect could result from an activation of limbic loops modulating motivational processes. Ann Neurol 2007
A kinetic study of novel bimetallic titanocene catalyst for syndiospecific styrene polymerization
Authors: Yim Jin‐Heong , Young Cho Kuk
Published: March 2007

A kinetic study of a syndiospecific polymerization was performed with two kinds of catalysts: Cp*Ti(O(C6H4)CMe2(C6H4)O)TiCp* [bimetallic system] and Cp*Ti(OMe)3 [monometallic system]. The purpose of this study was to determine the reasons behind the high activity of a bimetallic catalyst system. The active site structures of the two kinds of catalysts appears to be similar to the cationic Ti [III] species having η5‐pentamethylcyclopentadienyl ligand, while the rate of the activation process of the bimetallic catalyst was found to be higher than that of the monometallic catalyst. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Shear and elongational rheology of polyethylenes with different molecular characteristics. I. Shear rheology
Authors: Wei X. , Collier J. R. , Petrovan S.
Published: March 2007

Four metallocene polyethylenes (PE), one conventional low density polyethylene (LDPE), and one conventional linear low density polyethylene (LLDPE) were characterized in terms of their complex viscosity, storage and loss moduli, and phase angle at different temperatures. The effects of molecular weight, breadth of molecular weight distribution, and long‐chain branching (LCB) on the shear rheological properties of PEs are studied. For the sparsely long‐chain branched metallocene PEs, LCB increases the zero‐shear viscosity. The onsets of shear thinning are shifted to lower shear rates. There is also a plateau in the phase angle, δ, for these materials. Master curves for the complex viscosity and dynamic moduli were generated for all PE samples. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Flame retardancy and mechanical properties of EVA nanocomposites based on magnesium hydroxide nanoparticles/microcapsulated red phosphorus
Authors: Lv Jian‐ping , Liu Wen‐hong
Published: March 2007

The flame retardancy and mechanical properties of ethylene vinyl acetate (EVA) polymer nanocomposite based on magnesium hydroxide (MH) nanoparticles with lamellar‐shape morphological structures and synergistic agent microcapsulated red phosphorus (MRP) have been studied by limiting oxygen index (LOI), cone calorimeter test (CCT), UL‐94 test, tensile strength (TS), and elongation at break (EB). Results showed that LOI values of lamellar‐like nanosized MH (50 × 350 nm2) samples were 1–7 vol. % higher than those of the common micrometer grade MH (1–2 μm) in all additive levels. When 1–3 phr MRP substituted for nanosized MH filler, LOI value increased greatly from original 37 to 55, and met the V‐0 rating in the UL‐94 test. The values of TS for MH nanoparticles composites increased from 10.4 to 17.0 MPa as additive loading levels increased from 80 to 150 phr, respectively, while the corresponding values for common micrometer MH composites decreased steadily from 9.7 to 7.1 MPa. Thermogravimetric analysis (TGA) and dynamic Fourier‐transform infrared spectroscopy (FTIR) results revealed two‐step flame‐retardant mechanism. First, MH particles decompose endothermically with the release of 30.1% hydration water in the 320–370°C temperature range. Second, MRP promote the formation of compact charred layers slowly in the condensed phase in the 450–550°C temperature range. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
New photochemical approach to cellulose fabric and photoinitiator system
Authors: Han Samsook , Lee Muncheul
Published: March 2007

The surface modifications of cellulose substrate based on the photo‐induced reaction are closely related with the radicals introduced on the surface of cellulose substrates by light irradiation. We have evaluated the ability of radical formation in lyocell fabric and two water‐soluble photoinitiator systems by using photoluminescence analyses. Namely, the relative quantum yields of fluorescence and phosphorescence were estimated by the integrated emission intensity under the same values of light absorbance and the identical measuring conditions. First of all the [2‐(acryloyloxy)ethyl](4‐benzoylbenzyl)dimethylammonium bromide (PIA) system had larger UV absorbance values below 287 nm than [3‐(3,4‐dimethyl‐9‐oxo‐9h‐thioxanthene‐2‐yloxy)‐2‐hydroxypropyl]trimethylammonium chloride (PIB) system at the same concentration. The relative quantum yields of fluorescence and phosphorescence emission in PIA system were smaller than those in PIB system even if the two systems had the same values of light absorbance. Therefore it was found that the PIA system was more easily transited to the triplet‐state and the transited molecules reacted with the cellulose substrates more effectively. The modified cellulose fabric with 2‐(dimethylamino)ethyl chloride hydrochloride (AM1) and PI system had only a little different UV absorbance and photoluminescence properties from the untreated fabric system. However, the fabric modified with 2‐(4‐chlorophenyl)‐ethylamine (AM2) and PI system showed relatively big differences. The UV absorbance values were increased and the relative quantum yields of photoluminescence were decreased remarkably. We have acquired that the tertiary amine treated cellulose fabric were very effective in photo‐induced modification of cellulose. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Surface modification of a group of polymers using a low temperature cascade arc torch
Authors: Gilliam Mary , Yu Qingsong
Published: March 2007

Surface modification treatments were performed on six different types of polymers using low temperature cascade arc torch (LTCAT) of Ar with or without adding reactive gas of O2 or H2O vapor. The effects of the treatments on the wettability enhancement, surface degradation from oligomer formation, and surface stability from the mobility of surface moieties and hydrophobic recovery were investigated. Surface characterization techniques included the static Sessile droplet method and dynamic Wilhelmy balance method. Experimental results indicated that Ar LTCAT treatments of the polymers with shorter treatment times (2 s in most cases) resulted in stable and hydrophilic surfaces without any surface damage from oligomer formation, with the exception of nylon‐6. The excellent results from Ar LTCAT treatments were attributed to the CASING effect (crosslinking via activated species of inert gas). Addition of O2 into Ar LTCAT resulted in greater wettability of the treated surfaces, but increased surface damage from oligomer formation. Adding H2O vapor into Ar LTCAT produced extremely hydrophilic surfaces on the polymers, but pronounced surface damage. The surface oligomer formation was attributed to alkoxy degradation reactions and chain scission from overexposure to high energy species. Comparisons of the treatment outcomes for each type of polymer are discussed with respect to the degree of wettability enhancement, the stability of the treated surfaces, and the susceptibility to degradation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Personal digital assistant (PDA) cell phone units produce elevated extremely‐low frequency electromagnetic field emissions
Authors: Sage Cindy , Johansson Olle , Sage S. Amy
Published: March 2007

Initial tests indicate that personal and occupational use of personal digital assistants (PDAs or palm‐held wireless units) produce high intensity bursts of extremely‐low frequency electromagnetic fields (ELF‐EMF). These emissions could result in comparatively high ELF‐EMF exposure in persons that carry a PDA close to the body (i.e., in a pocket or on a belt); or held to the head for cell phone conversations. ELF‐EMF emissions of 10 µT were recorded on PDAs during normal office use over a 24 h test period. Results of ELF‐EMF measurements show that email transmit and receive functions produce rapid, short‐duration ELF‐EMF spikes in the 2–10 µT range, each lasting several seconds to over a minute apparently depending on file download size. Some units produced spikes as high as 30–60 µT during email activities. Cell phone activity on PDAs produced continuously elevated ELF‐EMF readings in the 0.5–1 µT range, as opposed to the rapid spiking pattern for email receipt and transmission. Switching the PDA unit from “OFF” to “ON” position resulted in single ELF‐EMF pulses of over 90 µT on two units. Email downloads into the PDA can occur randomly throughout the day and night when the unit is “ON”; thus the user who wears the PDA may be receiving high‐intensity ELF‐EMF pulses throughout the day and night. The frequency of email traffic on the PDA, and the power switching unit (battery unit) may affect the frequency and intensity of ELF‐EMF emissions. Bioelectromagnetics 28:386–392, 2007. © 2007 Wiley‐Liss, Inc.
The vertebral nerve revisited
Authors: Tubbs R. Shane , Loukas Marios , Remy Allison C. , Shoja Mohammadali M. , Salter E. George , Oakes W. Jerry
Published: March 2007

There is significant paucity in the literature regarding the vertebral nerve. Moreover, descriptions of this structure are conflicting. To evaluate further the anatomy and potential clinical significance of this structure, 10 fresh adult cadavers (20 sides) underwent dissection and macroscopic observation of this structure. All specimens were found to have a vertebral nerve that originated from the stellate ganglion with the exception of two left sides (10%) in which this nerve arose from the inferior cervical ganglion. This nerve ascended posteromedial to the vertebral artery. The vertebral nerve was found to be, in essence, a long and deep gray ramus communicans that connected most commonly the stellate ganglia to C6 or C7 spinal nerves by passing through the C6 and C7 transverse foramina. Fifteen percent of sides were found to have a vertebral nerve that was plexiform in its configuration. Fifty percent were found to have very small branches that entered the fibrous capsule of adjacent zygapophyseal and intervertebral joints. Some specimens were noted to have meningeal branches of the vertebral nerve. Based on our observations, the vertebral nerve is simply a deep ramus communicans, which often provides articular and meningeal branches to the adjacent spine. As neck pain is a significant reason for physician office visits, additional knowledge of the nerves innervating the joints and adjacent meninges of the neck could be important for both surgical and medical blockade of nerve fibers. Clin. Anat. 20:644–647, 2007. © 2007 Wiley‐Liss, Inc.
Variation of the spinal nerve compositions of thoracodorsal nerve
Authors: Lee Kyu‐Seok
Published: March 2007

Thoracodorsal nerve distributes to the latissimus dorsi muscle. The aim of this study was to investigate the anatomic variation of the spinal nerve compositions of thoracodorsal nerve and to confirm which spinal nerve is a main component in participating amount. The most frequent type was consisted of C7 and C8 in 60%. Next frequent type was C6, C7, and C8 in 25%. Third type was C6 and C7 in 10% and fourth type was C7 alone in 5%. The diameter of each spinal nerve comprising thoracodorsal nerve was 1.20 ± 0.23 (mean ± SD) mm at C7, 0.43 ± 0.15 mm at C8, and 0.33 ± 0.09 mm at C6. These results show that the C7 nerve was the main component of thoracodorsal nerve and the anatomic variation appeared at the spinal nerve that participate by small amounts, as be excepted (C6 and C8). Clin. Anat. 20:660–662, 2007. © 2007 Wiley‐Liss, Inc.
Cover Picture: Oligoribonucleotide Analogues Containing a Mixed Backbone of Phosphodiester and Formacetal Internucleoside Linkages, Together with Vicinal 2′‐O‐Methyl Groups (ChemBioChem 5/2007)
Authors: Rozners Eriks , Katkevica Dace , Strömberg Roger
Published: March 2007

The cover picture shows the chemical structure and a 3D representation (unoptimized Chem3D model) of RNA with hydrophobic chemical modifications. Replacement of selected phosphodiesters with formacetal linkages (blue) and methylation of the adjacent 2′‐hydroxyl groups (red) have independent and additive positive effects on the thermal stability of the RNA helices. Biophysical studies suggest that several complementary factors—reduction of electrostatic repulsion, solvation changes, conformational preorganization, hydrophobic interactions, etc.—interact to produce the observed stabilization. Modifications of RNA's sugar–phosphate backbone can be used to tune the thermal and enzymatic stability, hydrophobicity and electrostatic properties of RNA molecules. Chemically modified RNA has potential applications in gene‐control technologies, such as antisense and RNA interference. Further details can be found in the article by E. Rozners, et al. on p. 537 ff.
An integrative approach to the treatment of hyperhidrosis: review and case study
Authors: Kraft Tom , Kraft David
Published: March 2007

A review of the world literature indicates that there is a multiplicity of treatment approaches for hyperhidrosis. Most of these concentrate on the symptom itself and range from topical applications to sympathectomy. This paper demonstrates the value of an integrative approach in which behaviour therapy, combined with hypnosis, is used in conjunction with psychodynamic psychotherapy. This is a case study of a 58‐year‐old single man who, due to his severe social anxiety, had suffered from excessive sweating throughout his life. The dual approach to treatment concentrates both on the hyperhidrosis as well as its causation. The patient made an excellent recovery and this was maintained over a two year period. Copyright © 2007 British Society of Experimental & Clinical Hypnosis. Published by John Wiley & Sons, Ltd.
The value of using hypnosis in helping an adult survivor of childhood sexual abuse
Authors: Poon Maggie Wai‐ling
Published: March 2007

This report describes the successful treatment of a 33‐year‐old Chinese woman who had affect dysregulation and chronic trauma symptoms resulting from an intra‐familial childhood sexual abuse. A strategically phased multimodal treatment tailored to the needs of the client was used. The treatment framework consisted of three phases: training on affect management, strengthening the ego and re‐processing the trauma. Hypnosis was utilized as a means for grounding and stabilizing the overwhelming emotions; for addressing the negative self‐schema; and also for re‐processing the traumatic memories in a safe and controlled way. Data from self‐reports, observation and objective measures indicates a significant reduction in the trauma symptoms. Copyright © 2007 British Society of Experimental & Clinical Hypnosis. Published by John Wiley & Sons, Ltd.
Intramolecular Hydroamination/Cyclisation of Aminoallenes Mediated by a Neutral Zirconocene Catalyst: A Computational Mechanistic Study
Authors: Tobisch Sven
Published: March 2007

The complete catalytic cycle for the intramolecular hydroamination/cyclisation (IHC) of 4,5‐hexadien‐1‐ylamine (1) by a prototypical [ZrCp2Me2] precatalyst (2) has been scrutinized by employing a reliable DFT method. The present study conducted by means of a detailed computational characterisation of structural and energetic aspects of alternative pathways for all of the relevant elementary steps complements the mechanistic insights revealed from experimental results. The operative mechanism entails an initial transformation of precatalyst 2 into the thermodynamically prevalent, but dormant, bis(amido)–Zr compound in the presence of aminoallene 1. This complex undergoes a reversible, rate‐determining α‐elimination of 1 to form the imidoallene–Zr complex. The substrate‐free form, which contains a chelating imidoallene functionality, is the catalytically active species and is rapidly transformed into azazirconacyclobutane intermediates through a [2+2] cycloaddition reaction. This highly facile process does not proceed regioselectively because the alternative pathways for the formation of five‐ and six‐membered azacycles have comparable probabilities. Degradation of cyclobutane intermediates by following the most feasible pathway occurs through protonolysis of the metallacycle moiety and subsequent proton transfer from the ZrNHR moiety onto the azacycle. The five‐membered allylamine is generated through protonation at carbon atom C6 followed by α‐hydrogen elimination, whereas protonolysis of the cyclobutane moiety at the ZrN bond followed by proton transfer onto carbon atom C5 is the dominant route for the six‐membered product. Of the two consecutive proton transfer steps, the second one determines the overall kinetics of the entire protonation sequence. This process is predicted to be substantially slower than the cycloaddition reaction. The factors that regulate the composition of the cycloamine products have been elucidated.
Discussion on the Formation and Bonding in Three [Ga8R10] Compounds: The Diversity in Classical GaGa Bonds
Authors: Hartig Jens , Steiner Jochen , Stößer Anna , Schnöckel Hansgeorg
Published: March 2007

Herein we describe three Ga8 compounds that feature gallium atoms in an oxidation state of 1.25 with normal valent 2e–2c bonding. Their structures and the influence of their ligands (phosphorus and nitrogen atoms directly bonded to the Ga8 moieties) are discussed on the basis of DFT calculations, providing an insight into a probable mechanism for insertion reactions between GaX and GaX3 species that lead to a reaction cascade via halides like Ga2X4 and Ga5X7 to Ga8X10 and Ga8X122−, respectively. Finally, the Ga8 cores of the three title compounds were compared with the topology of carbon atoms in C8 alkanes.
Asymmetric Synthesis of Antimicrotubule Biaryl Hybrids of Allocolchicine and Steganacin
Authors: Joncour Agnès , Décor Anne , Liu Jian‐Miao , Tran Huu Dau Marie‐Elise , Baudoin Olivier
Published: March 2007

The asymmetric synthesis of novel axially chiral biaryl compounds 5 a–f containing a seven‐ or eight‐membered heterocyclic medium ring is described. These molecules can be considered to be structural hybrids of allocolchicine‐ and steganacin‐type natural products. The synthesis featured an atropo–diastereoselective biaryl Suzuki coupling in which a benzylic stereocenter efficiently transferred its stereochemical information to the biaryl axis. The coupling conditions were optimized, and two biphenylphosphane ligands (DavePhos and S‐Phos) were found to give the highest yields and diastereoselectivities. A three‐element stereochemical model was proposed to explain the observed diastereoselectivities. In a second key step, the medium ring of the target molecules was formed by a stereoselective SN1‐type cyclodehydration that probably involved a configurationally stable carbocationic intermediate, as supported by calculations. Alternatively, SN2‐type cyclizations were employed on the same Suzuki coupling products to give the target molecules in a stereodivergent or stereoconvergent manner. These cyclization methods furnished the target hybrid analogues 5 a–f with ee values above 94 %. All analogues were evaluated as antimicrotubule agents and against a panel of cancer‐cell lines using colchicine (1) and N‐acetylcolchinol (3) as references. Promising activities were found for R,aR‐configured compounds 5 a, b and 5 f; in particular, ethyl analogue 5 b showed a twofold antimicrotubule activity relative to colchicine.
GC‐MS detection of chiral markers in cocoa beans of different quality and geographic origin
Authors: Caligiani Augusta , Cirlini Martina , Palla Gerardo , Ravaglia Roberta , Arlorio Marco
Published: March 2007

Fermented cocoa beans (Theobroma cacao L., Sterculiaceae) from different countries of origin (Ecuador, Ghana, Trinidad) and cocoa beans roasted under defined conditions (industrial roasting; 150–220°C for 20 min, dry roasting in conventional oven) were analyzed for their contents of certain chiral hydroxy acids, catechins, and amino acids. Cocoa beans are fermented, dried, and industrially transformed by roasting for the production of chocolate, cocoa powders, and other cocoa‐related products. Fermentation and roasting conditions influence the contents of chiral compounds such as hydroxy acids, amino acids, and polyphenols, depending on technological procedures as well as some technical parameters. The aim of this work was to check if the content and nature of the named chiral compounds present both in fermented and roasted cocoa beans could be related to the traditional parameters used to classify the variety of seeds and the degree of fermentation. The extent of racemization of amino acids in fermented cocoa beans was low while it slowly increased during roasting, depending on the temperature applied. L‐lactic acid was always higher than the D‐form while citric acid was generally the most abundant hydroxy acid detected in beans. A correlation was found between polyphenol content and degree of fermentation, while epimerization of (−)‐epicatechin to (+)‐catechin was observed during roasting. On the whole, results showed that several chiral compounds could be considered as good quality markers for cocoa seeds and cocoa‐related products of different quality and geographic origin. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Comparative HPLC enantioseparation of ferrocenylalcohols on two cellulose‐based chiral stationary phases
Authors: Patti Angela , Pedotti Sonia , Sanfilippo Claudia
Published: March 2007

The direct HPLC enantiomeric separation of several ferrocenylalcohols on the commercially available Chiralcel OD and Chiralcel OJ columns has been evaluated in normal‐phase mode. Almost all the compounds were resolved on one or both chiral stationary phases (CSPs) with separation factor (α) ranging from 1.06 to 2.88 while the resolution (Rs) varied from 0.63 to 12.70 In the separation of the α‐ferrocenylalcohols 1a–e and the phenyl analogues 2a–e, which were all resolved except 1c, a similar trend in the retention behavior for the two series of alcohols was evidenced and the selectivity was roughly complementary on the two investigated CSP. For three ferrocenylacohols, chosen as model compounds, the influence of the mobile phase composition and temperature on the enantioseparation were investigated and additional information on the chiral recognition mechanism were deduced from the chromatographic behavior of their acetylderivatives. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Easily recyclable chiral polymeric Mn(III) salen complexes for oxidative kinetic resolution of racemic secondary alcohols
Authors: Kureshy Rukhsana I. , Ahmad Irshad , Pathak Kavita , Khan Noor‐Ul H. , Abdi Sayed H. R. , Prathap Jaya K. , Jasra Raksh V.
Published: March 2007

Chiral polymeric Mn(III) salen complexes were used efficiently for oxidative kinetic resolution of racemic secondary alcohols at room temperature. High chiral purity (ee; >99%) was achieved for the oxidative kinetic resolution of racemic secondary alcohols with 0.6 mol % catalyst loading in 60 min. The catalyst was easily recycled for five successive catalytic experiments. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Log‐domain linear transformation filters revised: improved building blocks and comparison results
Authors: Psychalinos Costas
Published: March 2007

A method for designing high‐order log‐domain filters has already been proposed in the literature based on the concept of the classical linear transformation (LT) filters. For this purpose, a substitution table containing the log‐domain LT equivalent of each passive element has been introduced. Drawbacks of the log‐domain filter topologies derived according to this table are the following: (a) a dc offset current appears at the output of all pole filters and (b) dc instability is observed in the case of the substitution of LC resonators. In addition, an alternative technique already proposed for simulating filters with LC resonators is valid only under small‐signal conditions. In order to overcome the aforementioned problems, new log‐domain LT equivalents of a number of passive elements are introduced in this paper. The correct operation of the novel blocks has been verified through simulation results. Also, a comparison concerning the behaviour of the log‐domain LT filters and that of the filters derived according to the leapfrog and the wave methods has also been performed. Copyright © 2007 John Wiley & Sons, Ltd.
Subject classification obtained by cluster analysis and principal component analysis applied to flow cytometric data
Authors: Lugli Enrico , Pinti Marcello , Nasi Milena , Troiano Leonarda , Ferraresi Roberta , Mussi Chiara , Salvioli Gianfranco , Patsekin Valeri , Robinson J. Paul , Durante Caterina , Cocchi Marina , Cossarizza Andrea
Published: March 2007

Background:

Polychromatic flow cytometry (PFC) allows the simultaneous determination of multiple antigens in the same cell, resulting in the generation of a high number of subsets. As a consequence, data analysis is the main difficulty with this technology. Here we show the use of cluster analysis (CA) and principal component analyses (PCA) to simplify multicolor data visualization and to allow subjects' classification.

Methods:

By eight‐colour cytofluorimetric analysis, we investigated the T cell compartment in donors of different age (young, middle‐aged, and centenarians). T cell subsets were identified by combining positive and negative expression of antigens. The resulting data set was organized into a matrix and subjected to CA and PCA.

Results:

CA clustered people of different ages on the basis of cytofluorimetric profile. PCA of the cellular subsets identified centenarians within a different cluster from young donors, while middle‐aged donors were scattered between these groups. These approaches identified T cell phenotypes that changed with increasing age. In young donors, memory T cell subsets tended to be CD127+ and CD95− whereas CD127−, CD95+ phenotypes were found at higher frequencies in people with advanced age.

Conclusions:

Our data suggest the use of bioinformatic approaches to analyze large data‐sets generated by PFC and to obtain the rapid identification of key populations that best characterize a group of subjects. © 2007 International Society for Analytical Cytology
Vaccinia virus impairs directional migration and chemokine receptor switch of human dendritic cells
Authors: Humrich Jens Y. , Thumann Peter , Greiner Sebastian , Humrich Jan H. , Averbeck Marco , Schwank Christiane , Kämpgen Eckhart , Schuler Gerold , Jenne Lars
Published: March 2007

A crucial event for the induction of an anti‐viral immune response is the coordinated, phenotype‐dependent migration of dendritic cells (DC) to sites of infection and secondary lymphoid organs. Here we show that the vaccinia virus (VV) strains Western Reserve (WR) and modified virus Ankara (MVA) inhibit directional migration of mature DC toward the lymphoid chemokines CCL19 and CXCL12 without affecting surface expression of the respective chemokine receptors or impairing undirected cellular locomotion. Instead, infection with VV results in a deficiency of extracellular signal‐regulated kinase‐1 and a disturbance of intracellular calcium mobilization, indicating a viral interference with signaling events downstream of the surface chemokine receptors. In immature DC, apart from inhibiting chemokine‐induced migration of infected DC, infection with both VV strains increases expression of the inflammatory chemokine receptors CCR1 and CXCR1 on non‐infected bystander DC, which depends on the activity of IFN‐α. Although functional, these chemokine receptors are resistant to lipopolysaccharide‐induced down‐regulation. In addition, VV‐infected and non‐infected bystander DC fail to up‐regulate the lymphoid chemokine receptor CCR7 upon activation, together pointing to a disability to undergo the chemokine receptor switch. This study shows that VV targets directional migration of professional antigen‐presenting cells at multiple functional levels, revealing a potent viral strategy of immune escape.

See accompanying commentary: http://dx.doi.org/10.1002/eji.200737215
BAFF and LPS cooperate to induce B cells to become susceptible to CD95/Fas‐mediated cell death
Authors: Acosta‐Rodríguez Eva V. , Craxton Andrew , Hendricks Deborah W. , Merino Maria C. , Montes Carolina L. , Clark Edward A. , Gruppi Adriana
Published: March 2007

Microorganisms with pathogen‐associated molecular patterns (PAMP) activate B cells directly by binding to TLR and also indirectly by inducing APC to release cytokines such as BAFF that promote B cell survival. We found that murine B cells activated concomitantly with LPS (TLR‐4 ligand) and BAFF are protected from spontaneous apoptosis, but are more susceptible to Fas/CD95‐mediated cell death. This increased susceptibility to Fas‐induced apoptosis is associated with a dramatic coordinated up‐regulation of Fas/CD95 and IRF‐4 expression through a mechanism mediated, at least in part, by inhibition of the MEK/ERK pathway. Up‐regulation of Fas/CD95 by BAFF is restricted to B cells activated through TLR‐4, but not through TLR‐9, BCR or CD40. TLR ligands differ in the BAFF family receptors (R) they induce on B cells: BAFF‐R is increased by the TLR4 ligand, LPS, but not by the TLR9 ligand, CpG‐containing oligodeoxynucleotides, which, in contrast, strongly up‐regulates transmembrane activator and CAML interactor (TACI). This suggests the up‐regulation of Fas by BAFF is mediated by BAFF‐R and not by TACI. Consistently, APRIL, which binds to TACI and B cell maturation antigen but not BAFF‐R, did not enhance Fas expression on LPS‐activated B cells. Increased susceptibility to Fas‐mediated killing of B cells activated with LPS and BAFF may be a fail‐safe mechanism to avoid overexpansion of nonspecific or autoreactive B cells.
Expression of a non‐DNA‐binding Ikaros isoform exclusively in B cells leads to autoimmunity but not leukemogenesis
Authors: Wojcik Heather , Griffiths Erin , Staggs Sarah , Hagman James , Winandy Susan
Published: March 2007

Ikaros is a transcriptional regulator whose function is essential for B cell development. It is expressed in the hematopoietic stem cell (HSC) through the mature B cell stage. Using genetically engineered mice in which the endogenous Ikaros gene is disrupted, it has been shown that a lack of Ikaros leads to a block in B cell development and that its severe diminution results in a hyperresponsive B cell compartment. Ikaros expression within the HSC has led to speculation as to whether the role of Ikaros in B cell biology is largely accomplished prior to B cell specification. In addition, widespread expression of Ikaros in hematopoietic cells leads to the possibility that some or all of the observed defects are not B cell autonomous. In this report, we demonstrate that over‐expression of a dominant interfering Ikaros isoform exclusively in B cells has profound effects on mature B cell function. We provide evidence that continued high‐level expression of Ikaros is essential for homeostasis of peripheral lymphocytes and maintenance of B cell tolerance. We also show that deregulation of Ikaros activity does not rapidly result in B cell leukemogenesis as it does with 100% penetrance within the T cell lineage.
[CuII4] Clusters From the Self‐Assembly of Two Imidazolidinyl 2‐Phenolate‐Bridged [CuII2] Units: The Role of the Chloride Bridge
Authors: Paital Alok Ranjan , Hong Chang Seop , Kim Hyoung Chan , Ray Debashis
Published: March 2007

A new family of tetracopper clusters [Cu4(μ4‐X)L2]ClO4·nH2O (1a–c) [X = Cl, Br, I; n = 12, 2, 2; H3L = 2‐(2′‐hydroxyphenyl)‐1,3‐bis[4‐(2‐hydroxyphenyl)‐3‐azabut‐3‐enyl]‐1,3‐imidazolidine] have been synthesised and characterised. The X‐ray crystal structure of 1a reveals that the template action of the spherical Cl– anion (μ4‐Cl–), which features a unique rectangular planar bridging mode, is responsible for the self‐assembly of two [Cu2L]+ units in complex 1a. In this family of complexes the spherical halides serve as templates to assemble the dimeric unit into tetrameric complexes, which gives an insight into the role of the halide bridge in tetranuclear complex formation. The capacity of this bridge to mediate magnetic coupling has been examined by bulk magnetic measurements for complex 1a. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
CuO/ZnO Nanoparticles in a Matrix of Amorphous Silica as High‐Surface Precursors for Methanol Synthesis
Authors: Rohe Bernd , Weiss Rainer , Vukojević Sascha , Baltes Christian , Muhler Martin , Tausch Michael , Epple Matthias
Published: March 2007

An intimate mixture of CuO/ZnO nanocrystals was prepared by an easy sol‐gel synthesis (precipitation in methanol by hydroxide in the presence of a silane). The organic substituents of the silane were almost completely removed by a subsequent photochemical oxidation. The resulting amorphous SiO2 prevented the growth of the catalytically active particles to larger crystals. The coating layer of silica can easily be penetrated by gaseous reactants, as shown by the high specific surface area of about 110–130 m2 g–1 (probably due to both silica and nanocrystalline CuO/ZnO) and the good catalytic activity in methanol synthesis from CO/CO2/H2 synthesis gas (7 to 37 %, compared to an industrial standard methanol catalyst). The ratio of CuO to ZnO can be easily varied by the used preparation method. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Repetitive Application of a Fluorous Chiral BINAP–Ru Complex in the Asymmetric Hydrogenation of Olefins
Authors: Horn Joachim , Bannwarth Willi
Published: March 2007

A trisperfluoroalkylsilyl‐modified (S)‐BINAP ligand has been prepared and its pertinent Ru complex applied to the asymmetric hydrogenation of olefins. Efficient separation of the Ru catalyst by filtration and its reuse was achieved. Relative to the untagged complex with a Ru‐leaching of 300 ppm, leaching into the product was low (1.6–4.9 ppm). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Decision support for network operation in an open power market
Authors: Warland Geir , Holen Arne T. , Solem Gerd , Uhlen Kjetil , Gimmestad Idar
Published: March 2007

The Norwegian system operator plans to change from (N‐1) to a more flexible cost‐based security criterion. The approach is illustrated using a simple example and then compared with alternative decision paradigms. The comparison shows how different paradigms may change ranking of operating alternatives and that the new cost‐based criterion still tends to favor alternatives close to (N‐1), provided application of a penalty factor giving additional and significant weight on interruption costs. Copyright © 2007 John Wiley & Sons, Ltd.
Improved analytical expressions for the reduction factor of feeding lines consisting of three single‐core cables
Authors: Popović Ljubivoje M.
Published: March 2007

The paper presents an original analytical procedure giving analytical expressions for the determination of ground fault current distribution for a fault located anywhere along a feeding line consisting of three single‐core cables. The derived analytical expressions are mathematically rigorous and take into account all the relevant factors without introducing some larger approximations or idealizations of the real electrical circuit. Correct estimation of ground fault current distribution is necessary in contemporary power engineering practice due to at least two important reasons. One of them is the possibility to a correct estimation of dangerous potential differences, touch and step voltage, which may appear during a ground fault at grounding system of the supplied station. The second reason is the possibility to choose single‐core cables of the feeding cable lines with a metallic sheath cross‐section large enough to withstand thermal strains caused by fault currents. The final result of the use of the analytical expressions derived here is the possibility to determine safe and cost‐effective solutions regarding the grounding systems of the supplied stations and regarding the cross‐sections of the metallic sheaths of single‐core cables. The validation of the derived expressions is verified by experimental measurements. Copyright © 2007 John Wiley & Sons, Ltd.
Geostatistical and multi‐elemental analysis of soils to interpret land‐use history in the Hebrides, Scotland
Authors: Entwistle J.A. , McCaffrey K.J.W. , Dodgshon R.A.
Published: March 2007

In the absence of documentary evidence about settlement form and agricultural practice in northwest Scotland before the mid‐18th century, a geoarchaeological approach to reconstructing medieval land use and settlement form is presented here. This study applies multielemental analysis to soils previously collected from a settlement site in the Hebrides and highlights the importance of a detailed knowledge of the local soil environment and the cultural context. Geostatistical methods were used to analyze the spatial variability and distribution of a range of soil properties typically associated with geoarchaeological investigations. Semivariograms were produced to determine the spatial dependence of soil properties, and ordinary kriging was undertaken to produce prediction maps of the spatial distribution of these soil properties and enable interpolation over nonsampled locations in an attempt to more fully elucidate former land‐use activity and settlement patterns. The importance of identifying the spatial covariance of elements and the need for several lines of physical and chemical evidence is highlighted. For many townships in the Hebrides, whose precise location and layout prior to extensive land reorganization in the late 18th–early 19th century is not recoverable through plans, multi‐elemental analysis of soils can offer a valuable prospective and diagnostic tool. © 2007 Wiley Periodicals, Inc.