bluuebunny/crossref_metadata_2025 huggingface dataset:
Making Molecules Make Themselves – the Chemistry of Artificial Replicators (Eur. J. Org. Chem. 5/2009)
Authors: Vidonne Annick , Philp Douglas
Published: January 2009

The cover picture shows in the lower left corner the schematic representation of a recognition‐mediated autocatalytic cycle that is capable of producing multiple copies of a single molecule in a template‐directed manner. The molecular recognition inherent in this cycle (red) leads to the accelerated formation of an imine bond (blue) between two building blocks through a ternary complex that renders the reaction between them pseudointramolecular. After bond formation, the product duplex dissociates and returns two molecules to the start of the autocatalytic cycle. The structure in the upper right corner represents the product duplex as determined by single‐crystal X‐ray diffraction ([18·18], taken from ref.[28]). The multiple copies of the reaction product shown highlight the exponential increase in the concentration of the product inherent in self‐replicating systems. Details are presented in the Microreview by A. Vidonne and D. Philp on p. 593 ff.
Electrochemical Detection of Cadmium and Lead Complexes with Low Molecular Weight Organic Acids
Authors: Dytrtová Jana Jaklová , Šestáková Ivana , Jakl Michal , Navrátil Tomáš
Published: January 2009

The Cd and Pb complexes with oxalic (OA) and citric acid (CA) were detected in model and soil solutions using cyclic and stripping voltammetry. A mixed complex consisting of Cd, Pb, and OA was found; its peak potential varied from −582.0 to −542.5 mV (vs. Ag/AgCl/KCl(3 mol L−1)). For mixed complex formation, the presence of PbOH+ species and Cd2+ in oxalic acid solution was necessary. Only the ‘simple’ complexes of CA with Pb and Cd were found in the model solution. The existence of all investigated metal complexes is confined to neutral pH range. The mixed complex was also found in real soil solutions.
Electrochemical Nanobiosensor for Glyphosate Herbicide and Its Metabolite
Authors: Songa Everlyne A. , Waryo Tesfaye , Jahed Nazeem , Baker Priscilla G. L. , Kgarebe Boitumelo V. , Iwuoha Emmanuel I.
Published: January 2009

The use of amperometric biosensor for the detection of glyphosate herbicide and its metabolite aminomethylphosphonic acid (AMPA) is presented. The biosensor was developed by electrochemically depositing poly(2,5‐dimethoxyaniline) (PDMA) doped with poly(4‐styrenesulfonic acid) (PSS) onto the surface of a gold electrode followed by electrostatic attachment of horseradish peroxidase (HRP) onto the PDMA‐PSS nanocomposite film. The PDMA‐PSS film was characterized by transmission electron microscopy (TEM) and Fourier Transform infrared (FTIR) spectroscopy. The HRP immobilized on the PDMA‐PSS film catalyzed the reduction of hydrogen peroxide, the inhibition of which was applied in the detection of glyphosate and AMPA. The limits of detection of the biosensor for glyphosate and AMPA were 0.16 μg L−1 and 1.0 μg L−1, respectively. The study demonstrates that the biosensor is very sensitive and could be a useful tool in the screening of glyphosate and AMPA at low concentrations.
Preparation and characterization of temperature‐responsive capillary electrochromatographic column using poly(N‐isopropylacrylamide)
Authors: Dai Rongji , Zhang Xuejing , Hu Na , Liu Yueying , Deng Yulin
Published: January 2009

Poly(N‐isopropylacrylamide) is a temperature‐responsive polymer, which is hydrophilic at low temperature but hydrophobic at high temperature. Using this characteristic, the polymer was bonded to the inner surface of fused‐silica capillary to prepare a temperature‐responsive column to study the separation behavior in electrochromatography.
Fact learning in complex arithmetic and figural‐spatial tasks: The role of the angular gyrus and its relation to mathematical competence
Authors: Grabner Roland H. , Ischebeck Anja , Reishofer Gernot , Koschutnig Karl , Delazer Margarete , Ebner Franz , Neuper Christa
Published: January 2009

Neuroimaging studies have revealed a strong link between mental calculation and the angular gyrus (AG) which has been interpreted to reflect arithmetic fact retrieval. Moreover, a stronger AG activation in individuals with higher mathematical competence has been reported. The present fMRI study investigates the specificity of the AG for arithmetic fact learning and the interplay between training and mathematical competence on brain activation. Adults of lower and higher mathematical competence underwent a five‐day training on sets of complex multiplication and figural‐spatial problems. In the following fMRI test session, trained and untrained problems were presented. Similar training effects were observed in both problem types, consisting of AG activation increases bilaterally and wide‐spread activation decreases in frontal and parietal regions. This finding indicates that the AG is not specifically involved in the learning of arithmetic facts. Competence‐related differences in the AG only emerged in untrained but not in trained multiplication problems. The relation between AG activation and mathematical competence in arithmetic problem solving therefore seems to be due to differences in arithmetic fact retrieval which can be attenuated through training. Hum Brain Mapp 2009. © 2009 Wiley‐Liss, Inc.
ICA decomposition of EEG signal for fMRI processing in epilepsy
Authors: Marques José P. , Rebola José , Figueiredo Patrícia , Pinto Alda , Sales Francisco , Castelo‐Branco Miguel
Published: January 2009

In this study, we introduce a new approach to process simultaneous Electroencephalography and functional Magnetic Resonance Imaging (EEG‐fMRI) data in epilepsy. The method is based on the decomposition of the EEG signal using independent component analysis (ICA) and the usage of the relevant components' time courses to define the event related model necessary to find the regions exhibiting fMRI signal changes related to interictal activity. This approach achieves a natural data‐driven differentiation of the role of distinct types of interictal activity with different amplitudes and durations in the epileptogenic process. Agreement between the conventional method and this new approach was obtained in 6 out of 9 patients that had interictal activity inside the scanner. In all cases, the maximum Z‐score was greater in the fMRI studies based on ICA component method and the extent of activation was increased in 5 out of the 6 cases in which overlap was found. Furthermore, the three cases where an agreement was not found were those in which no significant activation was found at all using the conventional approach. Hum Brain Mapp 2009. © 2009 Wiley‐Liss, Inc.
Five New Cassane‐Type Diterpenes from Caesalpinia crista
Authors: Yang Zheng‐Yi , Yin Yin‐Hua , Hu Li‐Hong
Published: January 2009

magnified image

Five new cassane‐type diterpenes, caesalpinista A (1), caesalpinista B (2), caesaljapin B (3), caesaljapin C (4), and caesalpinilinn (5) were isolated from the MeOH extract of the seeds of Caesalpinia crista. Their structures were elucidated by the analysis of their 1D‐ and 2D‐NMR spectra.
New Eremophilanolides from Ligularia hodgsonii
Authors: Xu Yang‐Jun , Nan Ze‐Dong , Li Wen‐Hai , Huang Hong‐Li , Yuan Cheng‐Shan
Published: January 2009

magnified image

A phytochemical study on the roots and rhizomes of Ligularia hodgsonii led to the isolation of seven new eremophilanolides (1–7), their structures were established as (1R,4S,5S,6R,8S,10R)‐1‐acetoxyeremophil‐7(11)‐en‐6,15;8,12‐diolide (1), (1R,4S,5S,6R,8S,10R)‐1‐acetoxy‐8β‐hydroxyeremophil‐7(11)‐en‐6,15;8,12‐diolide (2), (4S,5S,6R,8R,9S,10S)‐8‐hydroxy‐9‐(angeloyloxy)eremophil‐7(11)‐en‐6,15;8,12‐diolide (3), (4S,5S,6R,10R)‐10‐hydroxyeremophil‐7(11),8(9)‐diene‐6,15;8,12‐diolide (4), (4S,5S,6R,8R, 10R)‐6‐(angeloyloxy)‐8‐hydroxyeremophil‐7(11)‐en‐8,12‐olide‐15‐carboxylic acid methyl ester (5), (4S,5S,6R,8R,10R)‐6‐(angeloyloxy)‐8‐ethoxyeremophil‐7(11)‐en‐8,12‐olid‐15‐oic acid (6), (4S,5S,6S, 8R,10R)‐6‐(angeloyloxy)‐8‐ethoxyeremophil‐7(11)‐en‐8,12‐olid‐15‐oic acid (7) by means of spectroscopic analyses. The compounds were also evaluated for antibacterial activity, only compound 6 exhibited antibacterial activity against Bacillus subtilis.
DFT Studies on the Thermal Activation of Molecular Oxygen by Bare [Ni(H)(OH)]+
Authors: Zhang Xinhao , Schlangen Maria , Baik Mu‐Hyun , Dede Yavuz , Schwarz Helmut
Published: January 2009

magnified image

An extensive density‐functional theory (DFT) study has been conducted to shed light on the mechanisms of the recently reported gas‐phase ion‐molecule reactions of mass‐selected [Ni(H)(OH)]+ with O2 (M. Schlangen, H. Schwarz, Helv. Chim. Acta 2008, 91, 379). Except for the liberation of OH from the encounter complex, all of the other highly atom‐specific processes can be explained in a consistent manner.
One‐pot radiosynthesis of [13N]urea and [13N]carbamate using no‐carrier‐added [13N]NH3
Authors: Kumata Katsushi , Takei Makoto , Ogawa Masanao , Kato Koichi , Suzuki Kazutoshi , Zhang Ming‐Rong
Published: January 2009

The aim of this study was to develop a practical labeling method of [13N]ligands using no‐carrier‐added [13N]NH3 with high specific activity. [13N]urea analogues [13N]1a and [13N]2a or [13N]carbamate [13N]3a were synthesized by reacting isocyanate 5a, carbamoyl chloride 6a or chloroformate 7a with [13N]NH3. The precursors 5a–7a were prepared by treating amines 8a and 9a and alcohol 10a with triphosgene in situ. These reaction mixtures were not purified and were used directly for [13N]ammonolysis, respectively. Using the one‐pot method, we synthesized [13N]carbamazepine ([13N]4), a putative positron emission tomography ligand for brain imaging. Copyright © 2009 John Wiley & Sons, Ltd.
Dihydropyrimidine dehydrogenase mRNA expression in peripheral blood of rectal cancer patients is significantly associated with residual tumor and distant metastases following resection
Authors: Hoffmann Andreas‐Claudius , Brabender Jan , Metzger Ralf , Ling Fredericke , Warnecke‐Eberz Ute , Lurje Georg , Hoelscher Arnulf H. , Schneider Paul M. , Vallböhmer Daniel
Published: January 2009

Background

DPD and TS expression have been shown to correlate with response of 5‐FU based chemotherapy in colorectal cancer tissue. Little is known about mRNA expression levels of TS and DPD in peripheral blood. The goals of this study were to test the feasibility of DPD and TS detection in blood and their associations to TNM staging and complete surgical resection.

Methods

Whole blood was drawn 1 day pre‐ and 10 days post‐operatively from 23 patients with rectal cancer. Either adjuvant (n = 15) or neoadjuvant (n = 8) treatment was performed. Tumor cells were enriched from whole blood by density gradient centrifugation prior to extraction of total cellular RNA and subsequent direct quantitative reverse transcriptase‐PCR assays.

Results

DPD was detectable in 21/23 patients (91.3%) and TS in 14/23 (61.7%). Stepwise multiple linear regression models showed a significant association of DPD expression with distant metastases (P = 0.004) and residual tumor categories (P = 0.03).

Conclusions

Quantitative analysis of TS and DPD mRNA expression in peripheral blood of rectal cancer patients is technically feasible. DPD expression levels appear to be associated with residual tumor categories and might serve as a molecular marker for complete tumor resection. Larger studies seem to be warranted to scrutinize our hypothesis. J. Surg. Oncol. 2009;99:296–301. © 2009 Wiley‐Liss, Inc.
Combined atresiaplasty and tragal reconstruction for microtia and congenital aural atresia: Thesis for The American Laryngological, Rhinological, and Otological Society
Authors: Yellon Robert F.
Published: January 2009

Objective:

To describe a new technique for combining atresiaplasty with tragal reconstruction by performing the tragal reconstruction with cartilage grafting at the same time as the atresiaplasty for patients with microtia and congenital aural atresia. Hearing and canaloplasty outcomes for this combined technique are reported.

Patients:

Patients with aural atresia (n = 19) with (n = 16) or without (n = 3) microtia, and a Jahrsdoerfer grade of 6 or higher. Mean age was 8.3 years. Atresiaplasty was performed in 20 ears, with the new combined technique in 15 ears (75%).

Methods/Interventions:

During the meatoplasty portion of atresiaplasty, the tragus was reconstructed with a cartilage graft and an anteriorly pedicled skin flap.

Outcome Measures:

Hearing results, complications including canal stenosis, infections, sensorineural hearing loss, and facial nerve injuries.

Results:

The mean postatresiaplasty pure tone average (PTA) and air bone gap (ABG) were 37.5 and 29.4 dB, respectively. Eleven (55%) of the ears had an ABG of ≤30 dB, and 10 (50%) had speech reception thresholds (SRT) of ≤30 dB. Six ears (30%) had postoperative infections. Revision surgery was performed in four ears (20%) for canal/meatal stenosis, and in six (30%) for conductive hearing loss. Bone Anchored Hearing Aid™ was performed in six patients (30%). There was no sensorineural hearing loss or facial nerve injury.

Conclusions:

The new combined tragal reconstruction and atresiaplasty technique yielded satisfactory hearing, canal/meatal patency, and cosmetic results, with acceptable rates of complications. This combined tragal reconstruction and atresiaplasty technique is a valuable option in the armamentarium of microtia and atresia surgeons. Laryngoscope, 119:245–254, 2009
A survey of louisiana hospital ethics committees
Authors: Gonsoulin Thomas P.
Published: January 2009

Objectives:

To obtain a picture of hospital ethics committees (HECs) in the State of Louisiana. Compare results to other published studies. Gauge interest and participation in HECs by otolaryngologists.

Study Design:

Mail in questionnaire to all hospitals in Louisiana. Minisurvey distributed to randomly selected otolaryngologists.

Methods:

A questionnaire was mailed to the 194 hospitals identified by the Louisiana State Hospital Association. Questions included the presence and description of HECs plus the demographic data for the hospitals.

Results:

Eighty‐eight hospitals returned the survey. A HEC was present in 69. Membership was most often multidisciplinary. The annual growth rate ranged from 1.7% to 6%–8%. Teaching hospitals and larger hospitals tended to have a higher frequency rate of HECs. Like most US HECs, this state's committee primary functions included case consultation, education, and policy review. About 30% of otolaryngologists surveyed had some experience with a HEC.

Conclusions:

Louisiana's HEC construction and function appear similar to those committees found in other US hospitals. Membership is multidisciplinary. The three major functions are education, policy development and case consultation. Larger institutions tend to have a higher frequency of HECs. The growth rate of HECs increased in the early 1990s. As the ethical issues in contemporary medicine become more complex, especially with technological advances, HECs can anticipate constant new challenges. Future direction may focus on the evaluation of how well HECs function and on how improvements can be made. Laryngoscope, 119:330–340, 2009
Third generation photovoltaics
Authors: Brown G.F. , Wu J.
Published: January 2009

We review recent progress towards increasing solar cell efficiencies beyond the Shockley‐Queisser efficiency limit. Four main approaches are highlighted: multi‐junction cells, intermediate‐band cells, hot carrier cells and spectrum conversion. Multi‐junction cells use multiple solar cells that selectively absorb different regions of the solar spectrum. Intermediate‐band cells use one junction with multiple bandgaps to increase efficiencies. Hot‐carrier cells convert the excess energy of above‐bandgap photons into electrical energy. Spectrum conversion solar cells convert the incoming polychromatic sunlight into a narrower distribution of photons suited to the bandgap of the solar cell.
Studies on drug–DNA complexes, adriamycin–d‐(TGATCA)2 and 4′‐epiadriamycin–d‐(CGATCG)2, by phosphorus‐31 nuclear magnetic resonance spectroscopy
Authors: Agrawal Prashansa , Govil Girjesh , Barthwal Ritu
Published: January 2009

The complexes of adriamycin–d‐(TGATCA)2 and 4′‐epiadriamycin–d‐(CGATCG)2 are studied by one‐ and two‐dimensional 31P nuclear magnetic resonance spectroscopy (NMR) at 500 MHz in the temperature range 275–328 K and as a function of drug to DNA ratio (0.0–2.0). The binding of drug to DNA is clearly evident in 31P31P exchange NOESY spectra that shows two sets of resonances in slow chemical exchange. The phosphate resonances at the intercalating steps, T1pG2/C1pG2 and C5pA6/C5pG6, shift downfield up to 1.7 ppm and that at the adjacent step shift downfield up to 0.7 ppm, whereas the central phosphate A3pT4 is relatively unaffected. The variations of chemical shift with drug to DNA ratio and temperature as well as linewidths are different in each of the two complexes. These observations reflect change in population of BI/BII conformation, stretching of backbone torsional angle ζ, and distortions in OPO bond angles that occur on binding of drug to DNA. To the best of our knowledge, there are no solution studies on 4′‐epiadriamycin, a better tolerated drug, and binding of daunomycin or its analogue to d‐(TGATCA)2 hexamer sequence. The studies report the use of 31P NMR as a tool to differentiate various complexes. The specific differences may well be the reasons that are responsible for different antitumor action of these drugs due to different binding ability and distortions in DNA. Copyright © 2009 John Wiley & Sons, Ltd.
Cholesterol depletion induces anoikis‐like apoptosis via FAK down‐regulation and caveolae internalization
Authors: Park Eun‐Kyung , Park Mi Jung , Lee Seong‐Hee , Li Ying Chun , Kim Jungeun , Lee Jae‐Seon , Lee Jung Weon , Ye Sang‐Kyu , Park Jong‐Wan , Kim Chul‐Woo , Park Byung‐Kiu , Kim Yong‐Nyun
Published: January 2009

Caveolae (lipid rafts), microdomains of the plasma membrane, are known to contain various signalling molecules and consequently are involved in the regulation of many biological functions. To investigate the role of the caveolae in cell survival and adhesion, we disrupted the caveolae by depletion of cholesterol, a major lipid component of the caveolae, with methyl‐β cyclodextrin (MβCD) treatment of A431 cells. We found that cholesterol depletion induced an anoikis‐like cell death involving actin reorganization, resulting in a decrease in cell spreading and an increase in cell detachment, which was reversed by cholesterol addition. Disruption of caveolae led to the down‐regulation of FAK, Src activation, tyrosine phosphorylation of caveolin‐1 and mobilization of caveolae markers, GM1 and caveolin‐1, from the cell surface to the cytoplasm, which were also recovered by cholesterol addition. The expression of dominant‐active FAK was able to delay caveolae internalization and apoptosis and attenuated Akt inactivation by MβCD, whereas dominant‐negative FAK expression resulted in enhanced apoptosis. Moreover, FAK down‐regulation by si‐RNA resulted in Akt inactivation and thus increased cell death by MβCD treatment. Our results suggest that the cholesterol content and/or surface levels of the caveolae affect the activity of FAK, which in turn regulates caveolae internalization and cell survival. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Studies of the copolymerisation of acrylic acid with n‐butyl vinyl ether
Authors: Lee Qianhui , Hill David JT , Le Tri , Rasoul Firas , Whittaker Andrew K
Published: January 2009

BACKGROUND: Copolymers of acrylic acid (AA) are important materials for the preparation of glass ionomer cements. Copolymerisation of AA is widely used to alter the acid strength of the material and to increase the number of salt bridges formed in cements. In this paper we report the copolymerisation of AA with n‐butyl vinyl ether (BVE) to form unique copolymers of the hemiacetal ester and with BVE incorporated into the main chain.

RESULTS: AA and BVE undergo a spontaneous reaction to form a hemiacetal ester which can itself undergo free radical copolymerisation. The kinetics of this reaction in the bulk state have been examined. In addition, under these conditions BVE is incorporated into the polymer main chain via a free radical mechanism.

CONCLUSION: Novel copolymers of the hemiacetal ester and BVE have been prepared in this study. The hemiacetal side chains are labile under moderate heating, being converted back to the acid analogue. Copyright © 2009 Society of Chemical Industry
Infrared‐assisted proteolysis using trypsin‐immobilized silica microspheres for peptide mapping
Authors: Bao Huimin , Lui Ting , Zhang Luyan , Chen Gang
Published: January 2009

A novel proteolysis approach was developed by using infrared (IR) radiation and trypsin‐immobilized silica microspheres. Protein solutions containing trypsin‐immobilized microspheres in sealed transparent Eppendorf tubes were allowed to digest under an IR lamp at 37°C. The feasibility and performance of the present proteolysis approach were demonstrated by the digestion of BSA and cytochrome c (Cyt‐c) and the digestion time was significantly reduced to 5 min. The obtained digests were identified by MALDI‐TOF‐MS with the sequence coverages of 54% (BSA) and 83% (Cyt‐c) that were better than those obtained by conventional in‐solution tryptic digestion. The suitability of the new digestion approach to complex proteins was demonstrated by digesting human serum. The present proteolysis strategy is simple and efficient and will find a wide range of application in protein identification.
The BRCA Self‐Concept Scale: a new instrument to measure self‐concept in BRCA1/2 mutation carriers
Authors: Esplen Mary Jane , Stuckless Noreen , Hunter Jonathan , Liede Alexander , Metcalfe Kelly , Glendon Gordon , Narod Steven , Butler Kate , Scott Jenna , Irwin Ellen
Published: January 2009

Genetic testing for BRCA1/2 has psychosocial impacts including those related to views of personal health, sense of self and identity and body image. The centrality of a person's self‐concept in maintaining physical and psychosocial well‐being has been well recognized; however, to date research exploring altered self‐concept related to carrier knowledge is limited.

Objective: The objective of the study was to develop and validate a scale to measure the self‐concept among individuals testing positive for BRCA1/2 mutations.

Methods: The study was conducted in two phases: phase I: item generation and refinement and phase II: scale selection and initial validation. During phase I, scale items were generated through individual interviews and focus groups of women with BRCA1/2 mutations, including women with or without a prior diagnosis of cancer. In phase II items were selected based on several criteria resulting in a 25‐item scale, which underwent a reliability analyses and preliminary validation with 115 women. A second sample of 126 women was used to conduct further validation and samples were pooled to conduct factor analysis and the final scale selection.

Results: A 17‐item self‐concept scale emerged having three factors: stigma, vulnerability and mastery demonstrating evidence for an instrument with promising psychometric properties (total scale alpha=0.90).

Conclusions: The scale has direct relevance for research in facilitating our understanding of the specific aspects of the self, which are vulnerable to BRCA1/2 testing and which play a role in clinical outcomes, to facilitate the development and specific testing of interventions and may be used as an outcome measure. Specific measurement tools for genetic populations will ultimately assist in the clinical management of these populations. Copyright © 2009 John Wiley & Sons, Ltd.
Impedimetric detection of covalently attached biomolecules on field‐effect transistors
Authors: GhoshMoulick Ranjita , Vu Xuan Thang , Gilles Sandra , Mayer Dirk , Offenhäusser Andreas , Ingebrandt Sven
Published: January 2009

A method for impedimetric detection of biomolecules with field‐effect transistor (FET) arrays is presented. For biomolecular detection, the corresponding molecules such as single‐stranded DNA or bovine serum albumine (BSA) were covalently immobilized to the gate structure of 16‐channel open‐gate FET devices. A micro spotter system was used to site‐selectively attach biomolecules to selected channels out of the array. The differential transistor transfer function (TTF) of the FETs with attached biomolecules compared to free FETs was recorded. With this impedimetric technique it was possible to reliably detect biomolecules, because the recordings were not disturbed by the typical long‐term drift of the sensors like in potentiometric readout mode. For transistor gates, where DNA sequences of different length were attached, small differences in the TTF spectra were detected. When BSA was covalently immobilized to the FETs clear differences in the TTF spectra were detected, which were independent on buffer pH variations around the isoelectric point of the protein. Based on the results presented in this article it can be concluded, that the TTF method detects passive components of the biomolecules like resistance and capacitance rather than surface charge effects. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Baric and temperature dependences of kinetic coefficients in p‐Cd0.7Mn0.3GeAs2 at atmospheric and high pressures
Authors: Mollaev A. Yu. , Kamilov I. K. , Arslanov R. K. , Zalibekov U. Z. , Arslanov T. R. , Bashirov R. R. , Novotorzev V. M. , Marenkin S. F.
Published: January 2009

The pressure dependences of the resistivity ρ (P) and Hall coefficient Rρ(P) have been measured for heavily doped Cd0.7Mn0.3GeAs2 at increasing and decreasing pressure at room temperature. To investigate temperature properties of conductivity in Cd0.7Mn0.3GeAs2, the temperature dependences ρ (T) and Rρ(T) have been defined in the temperature range 77–450 K at atmospheric pressure. The pioneering measurements of magnetoresistance Δρxx (H, P)/ρ0(P) in Cd0.7Mn0.3GeAs2 are presented. A hysteresis of magnetoresistive effect has been found when pressure rises and falls. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hole density and anisotropic mobility of Mg‐doped InN from the analysis of LO phonon‐hole plasmon properties
Authors: Ishitani Yoshihiro , Fujiwara Masayuki , Wang Xinqiang , Che Song‐Bek , Yoshikawa Akihiko
Published: January 2009

Infrared reflectance and ellipsometry measurements are applied in order to study the influence of Mg‐doping on the properties of hexagonal InN films. Reflectance spectrum characteristics reveal the large effective mass and large plasmon damping rate just in the region where net acceptors have been observed by electrolyte capacitance‐voltage technique. The numerical spectrum analysis accounting for the modulation of the normal mode energies of longitudinal optical phonon–plasmon coupling (LOPC) by the large hole scattering rate yields the hole density of (0.1‐1.2)×1019 cm–3 and optical mobility of 25‐70 cm2/Vs for the direction vertical to the c axis. The properties of the bulk‐like part of the films are determined by the optical techniques. Infrared ellipsometry on the study of anisotropy of LOPC mode broadening indicates that threading dislocations or columnar grain boundaries cause the significantly larger scattering rate for holes vibrating along the c axis than those vibrating vertical to the c axis. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical properties and device characteristics of InAlN/AlGaN/ AlN/GaN heterostructure field effect transistors
Authors: Hiroki Masanobu , Maeda Narihiko , Kobayashi Takashi
Published: January 2009

We fabricated InxAl1–xN/Al0.38Ga0.62N/AlN/GaN hetero‐structures with flat surfaces and high electron mobility. The density of the two‐dimensional electron gas varies over a wide range and decreases from 2.3 x 1013 to 9 x 1012 cm–2. The electron mobility is higher than that of conventional InAlN/AlN/GaN in the range of In content in InAlN from 0.13 to 0.31. The mobility increases from 1050 to 1960 cm2/V·s with increasing In content. A high transconductance of 230 mS/mm and a large drain current of 1.2 A/mm are obtained in spite of the long 1.5‐μm gate and high contact resistance of about 1 Ω·mm in field effect transistors made from both structures. For the new structure, the subthreshold swing is lowered 1.5 to 0.6 V/dec. and the dark current is reduced 10–2 to 10–3 A/mm. The smoother surface of the new structure improves these parameters. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Antihyperlipidemic Compounds from the Fruit of Piper longum L.
Authors: Jin Zhuang , Borjihan Gereltu , Zhao Ruiguo , Sun Zhaorigetu , Hammond Gerald B. , Uryu Toshiyuki
Published: January 2009

A bioassay‐guided isolation of an ethanol extract of the fruit of Piper longum L. yielded piperlonguminine, piperine and pipernonaline, as the main antihyperlipidemic constituents. They exhibit appreciable antihyperlipidemic activity in vivo, which is comparable to that of the commercial antihyperlipidemic drug, simvastatin. Copyright © 2009 John Wiley & Sons, Ltd.
Accuracy in planar cutting of bones: an ISO‐based evaluation
Authors: Cartiaux Olivier , Paul Laurent , Docquier Pierre‐Louis , Francq Bernard G , Raucent Benoît , Dombre Etienne , Banse Xavier
Published: January 2009

Background

Computer‐ and robot‐assisted technologies are capable of improving the accuracy of planar cutting in orthopaedic surgery. This study is a first step toward formulating and validating a new evaluation methodology for planar bone cutting, based on the standards from the International Organization for Standardization.

Methods

Our experimental test bed consisted of a purely geometrical model of the cutting process around a simulated bone. Cuts were performed at three levels of surgical assistance: unassisted, computer‐assisted and robot‐assisted. We measured three parameters of the standard ISO1101:2004: flatness, parallelism and location of the cut plane.

Results

The location was the most relevant parameter for assessing cutting errors. The three levels of assistance were easily distinguished using the location parameter.

Conclusions

Our ISO methodology employs the location to obtain all information about translational and rotational cutting errors. Location may be used on any osseous structure to compare the performance of existing assistance technologies. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of sprayer configuration on efficacy for the control of scab on crabapple using electron beam analysis
Authors: Krause Charles R. , Derksen Richard C. , Horst Leona E. , Zhu Heping , Zondag Randall
Published: January 2009

Foliar diseases like apple scab result in significant economic losses to growers each year. Assessment in past studies involved only macroscopic disease ratings. More complete knowledge of the fate and behavior of fungicide has been needed to reduce pesticide use with less off‐target contamination. Field studies were conducted in a production nursery for over 4 years. A moderately susceptible cultivar of ornamental crabapple, Malus spp. cv “Candied Apple”, was sprayed with a fungicide using two sprayer/nozzle configurations. The fungicide used in this study was Mankocide, combination of Cu(OH)2 and mancozeb that permitted electron beam analysis (EBA) identification based on the presence of Cu, MN and Zn in the molecule and formulation. EBA was conducted using a cold field emission scanning electron microscopy and energy dispersive x‐ray microanalyzer. Fresh leaf samples were placed on sticky stubs after each fungicide treatment. The presence or absence of fungal conidia and fungicide residue were measured. EBA permitted direct visualization and identification of the pathogens, morphologically, and chemical characterization of fungicide present. EBA was useful to quantify disease control related to fungicide coverage, sprayer configuration and treatment efficacy. SCANNING 31: 24–27, 2009. Published 2009 by Wiley Periodicals, Inc.
“State of the Art” in Liver Resection and Living Donor Liver Transplantation: A Worldwide Survey of 100 Liver Centers
Authors: Breitenstein Stefan , Apestegui Carlos , Petrowsky Henrik , Clavien Pierre Alain
Published: January 2009

Background

New strategies have been developed to expand indications for liver surgery. The objective was to evaluate the current practice worldwide regarding critical liver mass and manipulation of the liver volume.

Methods

A survey was sent to 133 liver centers worldwide, which focused on (a) critical liver volume, (b) preoperative manipulation of the liver mass, and (c) use of liver biopsy and metabolic tests.

Results

The overall response rate to the survey was 75%. Half of the centers performed more than 100 resections per year; 86% had an associated liver transplant program. The minimal remnant liver volume for resection was 25% (15–40%) in cases of normal liver parenchyma and 50% (25–90%) in the presence of underlying cirrhosis. The minimal remnant liver volume for living donors was 40% (30–50%), whereas the accepted graft body weight ratio was 0.8 (0.6–1.2). Portal vein occlusion to manipulate the liver volume before resection was performed in 89% of the centers.

Conclusions

Limits of liver volume and the current practice of liver manipulation before resection were comparable among different centers and continents. The minimal remnant liver volume in normal liver was 25%, and more than 80% of the centers performed portal vein occlusion.
Locking, Jamming, and Ratchet Mechanisms of Sliding Surgical Knots Topologically Revisited
Authors: Hage J. Joris , van der Steen Lydia P. E.
Published: January 2009

Background

The geometry of lockable, ratchet, or jamming sliding surgical knots was assessed to enhance practical and topological understanding of knots among surgeons.

Methods

Using a database of more than 100 surgical knots, 29 knots that reportedly feature locking, ratchet, or jamming mechanisms were topologically assessed for their ability to lock antegradely or retrogradely, to lock by assuming their flat geometry, or to jam.

Results

Eighteen of the 29 investigated surgical knots have previously been mistakenly categorized. Topologically, the concept of a true ratchet knot is a fallacy.

Conclusions

Surgical knots may be consistently classified on the basis of precise and detailed definition of various anti‐backsliding geometrical characteristics of knots.
Is It Necessary to Discuss Person‐Oriented Research in Community Psychology?
Authors: Anne Bogat G.
Published: January 2009

A brief overview of the person orientation is provided. It is then argued that research in community psychology, similar to every other field in psychology, has mainly focused on variables, not individuals. Suggestions are provided for how the person orientation can be applied to understanding settings and environments as well as the theoretical and methodological contributions community psychologists can make to further person oriented methods.
The emerging of “female citizen”: The subject identity of modern Chinese women through literary practices
Authors: Yigang QIAO , Kun LIU
Published: January 2009

The construction of “citizen-state” relations in the intellectual world of modern China and the establishment of individual citizenship in political discourse have opened up a political and discourse sphere for modern women to strive for new identities, wherein some intellectually advanced women have managed to establish their individual identity as “female citizen” by carrying the debate on the relationship between women and the state with regard to their rights and responsibilities, and on the relationship between gender role and citizenship. Though the idea of “female citizen” was not provided with a political theory of practical significance, the subject identity of women, however, was repeatedly spoken about and strengthened in brand-new literary practices, resulting in a dynamic discourse of “female citizen”; in the meantime, disagreements concerning the concepts of “female rights,” “civil rights,” and “natural rights” have all helped create significant tension inside the related discourse sphere.
The Buttazzoni Classification of Distal Radial Fractures in Adults: Interobserver and Intraobserver Reliability
Authors: Wadsten Mats Å. , Sayed-Noor Arkan S. , Sjù;dén Gùran O. , Svensson Olle , Buttazzoni Gunnar G.
Published: January 2009

Despite the fact that distal radial fracture is the commonest fracture, there is a little evidence-based knowledge about the value of its classification to guide management and predict prognosis. The available classification systems are either complicated or weakly applicable in clinical practice. Older's classification is the most reliable, but does not cover all radial fracture types. We evaluated the interobserver and intraobserver reliability of a new classification system which is a modification of Older's classification covering all radial fracture types. Two hundred and thirty-two consecutive adult patients with acute distal radial fractures were blindly evaluated according to the new classification by three orthopedic surgeons twice with 1-year interval. The interobserver reliability was measured using the Fleiss kappa coefficient, and the intraobserver reliability was measured using the Cohen's kappa coefficient. The new classification showed fair to substantial interobserver and intraobserver reliability, i.e., results comparable to the reliability of commonly used classification systems. The reliability was better for younger patients and when evaluation was carried out by hand-surgery-interested orthopedic surgeons. The new classification system is simple, covers all radial fracture types, and has an acceptable reliability. Further studies are needed to judge its ability to direct management and predict prognosis.
Synthesis and Characterization of Aromatic–Aliphatic Polyamide Nanocomposite Films Incorporating a Thermally Stable Organoclay
Authors: Zulfiqar Sonia , Sarwar MuhammadIlyas
Published: January 2009

Nanocomposites were synthesized from reactive thermally stable montmorillonite and aromatic–aliphatic polyamide obtained from 4-aminophenyl sulfone and sebacoyl chloride. Carbonyl chloride terminal chain ends were generated using 1% extra sebacoyl chloride that could interact chemically with the organoclay. The distribution of clay in the nanocomposites was investigated by XRD, SEM, and TEM. Mechanical and thermal properties of these materials were monitored using tensile testing, TGA, and DSC. The results revealed delaminated and intercalated nanostructures leading to improved tensile strength and modulus up to 6 wt% addition of organoclay. The elongation at break and toughness of the nanocomposites decreased with increasing clay contents. The nanocomposites were thermally stable in the range 400–450 °C. The glass transition temperature increased relative to the neat polyamide due to the interfacial interactions between the two phases. Water uptake of the hybrids decreased upon the addition of organoclay depicting reduced permeability.
Shapes and Coiling of Mixed Phospholipid Vesicles
Authors: Paredes‐Quijada Gerardo , Aranda‐Espinoza Helim , Maldonado Amir
Published: January 2009

We have studied some physical properties of mixed phosphatidylcholine (SOPC)–phosphatidylserine (SOPS) vesicles. In a previous work (Paredes et al. in J Biol Phys 32:177–181, 2006) it was shown that the shape of the vesicles depends on the SOPC:SOPS composition, and that coiled cylindrical vesicles exist in samples with low SOPS contents. In this work, we further studied the same system of mixed vesicles. Differential scanning calorimetry (DSC) experiments displayed peaks characteristic of lipid mixing in the liquid state, ruling out a possible phase transition as an explanation of vesicle coiling. In addition, small‐angle X‐ray scattering (SAXS) experiments allowed us to estimate the periodicity distance inside the vesicles. This distance is d ≈ 60 Å, as revealed by the Bragg peaks observed in the experiments. Finally, the coiling transition of a cylindrical vesicle was observed under solvent flow. This observation indicates that the vesicle coiling reported previously for this system (Paredes et al. in J Biol Phys 32:177–181, 2006) does not depend on the SOPC:SOPS composition alone, but also on mechanical perturbations during the preparation steps.
Distribution of complex phase velocities for small disturbances to pipe Poiseuille flow
Authors: NISHIYAMA TAKAHIRO
Published: January 2009

It is numerically known that normal modes for small disturbances to pipe Poiseuille flow have complex phase velocities c which form a Y-shaped set of discrete points in the fourth quadrant, when the Reynolds number R is large. In this paper, the eigenvalue problem of determining c for axisymmetric torsional disturbances is treated, and the Y-shaped distribution of these c is studied analytically (with a little aid from numerics) by using some asymptotic forms of a Whittaker function. As a result, a Y-shaped contour on which eigenvalues c are approximately located is obtained, independent of the wavenumber α and R, from simple equations which contain elementary functions only. Naturally, the location of each individual c depends on α and R. How it changes on the contour when large R is becoming still larger is explained. Several approximate values of c on the contour are compared with c computed by Schmid & Henningson (1994), and their agreement is seen to be good. Furthermore, the limit Re c → 2/3 as Im c → −∞ is rigorously proved when R is fixed at an arbitrary number, which is not required to be large. This limit is shown to be true also with eigenvalues c for axisymmetric meridional disturbances. The alternate distribution of c for torsional and meridional disturbances on a branch of the Y-shaped contour is explained.
Nonlinear dynamics of viscoelastic Taylor–Couette flow: effect of elasticity on pattern selection, molecular conformation and drag
Authors: THOMAS D. G. , KHOMAMI B. , SURESHKUMAR R.
Published: January 2009

Three-dimensional and time-dependent simulations of viscoelastic Taylor–Couette flow of dilute polymer solutions are performed using a fully implicit parallel spectral time-splitting algorithm to discover flow patterns with various spatio-temporal symmetries, namely rotating standing waves (RSWs), disordered oscillations (DOs) and solitary vortex structures referred to as oscillatory strips (OSs) and diwhirls (DWs). A detailed account of the impact of flow transitions on molecular conformation and viscoelastic stress, velocity profiles, hydrodynamic drag force and energy spectra of time-dependent flow states is presented. Overall, predicted pattern selection and flow features compare very favourably with experimental observations. For elasticity number E, that signifies the ratio of elastic to viscous forces, >0.1, and when the shear rate (cylinder rotation speed) is increased above the linear stability threshold, the circular Couette flow (CCF) becomes unstable to RSWs which are characterized by a checkerboard-like pattern in the space–time plot of radial velocity, implying symmetry between inflow/outflow (I/O) regions. As the shear rate is further increased, perturbations that break the I/O symmetry are amplified leading to DOs and/or flame-like patterns with spectral mechanical energy transfer reminiscent of elastically induced low-Reynolds-number turbulence. However, when the shear rate is decreased from those at which such chaotic states are observed, the radially inward acting polymer body force created by flow-induced molecular stretching causes the development of narrow inflow regions surrounded by much broader weak outflow domains. This promotes the formation of solitary vortex structures, which can be stationary and axisymmetric (DWs) or time-dependent (OSs). The dynamics of the formation of these structures by merging and coalescence of vortex pairs and the implication of such events on instantaneous hydrodynamic force are studied. For O(1) values of E, OSs and DWs appear approximately at constant values of the We, defined as the ratio of polymer relaxation time to the inverse shear rate in the gap. As shear rate is decreased further, DWs decay to CCF although at We values less than the linear stability threshold. The flow transitions are hysteretic with respect to We, as evidenced by a plot of drag force versus We.
Large eddy simulation of a circular jet: effect of inflow conditions on the near field
Authors: KIM JUNGWOO , CHOI HAECHEON
Published: January 2009

In the present study, the effects of the jet inflow conditions such as the initial momentum thickness (θ) and background disturbances on the downstream evolution of a circular jet are investigated using large eddy simulation (LES). We consider four different initial momentum thicknesses,D/θ = 50, 80, 120 and 180, and three different Reynolds numbers,ReD=UJD/ν = 3600, 104and 105, whereUJis the jet inflow velocity andDis the jet diameter. The present study shows that the jet characteristics significantly depend on both the initial momentum thickness and the Reynolds number. For all the Reynolds numbers considered in this study, vortex rings are generated at an earlier position with decreasing initial momentum thickness. In case of a relatively low Reynolds number ofReD= 3600, at smaller initial momentum thickness, early growth of the shear layer due to the early generation of vortex ring leads to the occurrence of large-scale coherent structures in earlier downstream locations, which results in larger mixing enhancement and more rapid increase in turbulence intensity. However, at a high Reynolds number such asReD= 105, with decreasing initial momentum thickness, rapid growth of the shear layer leads to the saturation of the shear layer and the generation of fine-scale turbulence structures, which reduces mixing and turbulence intensity. With increasingReθ(=UJθ/ν), the characteristic frequency corresponding to the shear layer mode (Stθ=fθ/UJ) gradually increases and reaches near 0.017 predicted from the inviscid instability theory. On the other hand, the frequency corresponding to the jet-preferred mode (StD=f D/UJ) varies depending onReDandD/θ. From a mode analysis, we show that, in view of the energy of the axial velocity fluctuations integrated over the radial direction, the double-helix mode (mode 2) becomes dominant past the potential core, but the axisymmetric mode (mode 0) is dominant near the jet exit. In view of the local energy, the disturbances grow along the shear layer near the jet exit: for thick shear layer, mode 0 grows much faster than other modes, but modes 0–3 grow almost simultaneously for thin shear layer. However, past the potential core, the dominant mode changes from mode 0 near the centreline to mode 1 and then to mode 2 with increasing radial direction regardless of the initial shear layer thickness.