bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of trypsin inhibitor on plasma antioxidant activity and lipid levels in mice from sweet potato roots
Authors: Huang Guan‐Jhong , Chang Heng‐Yuan , Chen Hsien‐Jung , Lu Te‐Ling , Chang Yuan‐Shiun , Sheu Ming‐Jyh , Lin Yaw‐Huei
Published: September 2008

BACKGROUND: Several inflammatory diseases are thought to be related to oxidative injury and reactive oxygen species have been proposed as important causative agents of heart disease and ageing. This study was designed to investigate the effects of sweet potato trypsin inhibitor (SPTI) on antioxidant enzymes, lipid peroxidation and lipid profiles in mice.

RESULTS: Twenty mice were randomly divided into four groups and fed with TI (10, 50 and 100 mg kg−1 BW) as treatment and with saline as a control in addition to regular diets. After 35 days, Trolox equivalent antioxidant capacity (TEAC), triglyceride (TG) and cholesterol levels in plasma and superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx), thiobarbituric acid reactive substances (TBARS) in liver were measured. Serum from the group that had received the the highest oral dose of SPTI (100 mg kg−1 BW) had the highest total antioxidant activity (expressed as 3.59 ± 0.237 mmol L−1 TEAC). The SOD, catalase and GPx activity of SPTI groups were significantly increased compared with the control group. Malondialdehyde (MDA) was significantly lower in all experimental groups compared with the control one. No significant differences in the concentration of low‐density lipoprotein (LDL)‐cholesterol was found, but high density lipoprotein (HDL)‐cholesterol, triglyceride (TG) and total cholesterol tended to decrease.

CONCLUSION: This study showed that the oral intake of SPTI in mice may trigger inflammatory responses which result in an increase in antioxidant enzyme activities, and a decrease in MDA, TG and total cholesterol, which are known risk factors of inflammatory and heart disease. Copyright © 2008 Society of Chemical Industry
High grade osteosarcoma of the extremities with lung metastases at presentation: Treatment with neoadjuvant chemotherapy and simultaneous resection of primary and metastatic lesions
Authors: Bacci Gaetano , Rocca Michele , Salone MariaCristina , Balladelli Alba , Ferrari Stefano , Palmerini Emanuela , Forni Cristiana , Briccoli Antonio
Published: September 2008

Background and Methods

Between 1986 and 2001, 162 patients with extremity osteosarcoma and lung metastases at presentation, were treated by neoadjuvant chemotherapy, simultaneous resection of primary and, when feasible, secondary lesions followed by chemotherapy.

Results

After neoadjuvant chemotherapy, metastases disappeared in 14 patients, 16 were judged unresectable by both our thoracic surgeons, 132 had primary tumors and lung metastases removed simultaneously. Removal of lung metastases was complete in 123 and incomplete in 9. Histologically lesions were benign in 32 patients. For the 100 patients simultaneously operated with histologically proven lung metastases, 5‐year event‐free survival (EFS) was 18.9%; 27.4% for the 91 who had a complete resection of pulmonary lesions and entered remission as opposed to none for 9 patients who had incomplete removal of lung nodules. Among these 91, 5‐year EFS was significantly higher for patients with monolateral compared to bilateral lesions (27.1% vs. 7.9%, P < 0.02) and when only one to three metastatic nodules were present (40.0% vs. 13.3%, P < 0.0001).

Conclusions

These different results, demonstrate that our treatment had a reasonable survival outcome whereas other groups continue to have dismal prognosis. More efforts should be made to improve survival by identifying new active agents or novel approaches with cellular molecular targets. J. Surg. Oncol. © 2008 Wiley‐Liss, Inc.
Nullbruchlinie der Dauerfestigkeit
Authors: Köhler J.
Published: September 2008

Mit ca. 45 Proben werden Dauerschwingversuche durchgeführt. In der anschließenden Auswertung wird die Nullbruchlinie mit der Bruchwahrscheinlichkeit 1ppm ermittelt.

Die Nullbruchlinie ist die gemeinsame Wöhlerlinie für ungekerbte und gekerbte Bauteile. Sie gilt für große und kleine Bauteile aus dem gleichen Werkstoff. Man muß den statistischen Größeneinfluß nicht berücksichtigen.
Experimental studies on selective laser melting of metallic parts
Authors: Meier H. , Haberland Ch.
Published: September 2008

Laser assisted generative production techniques like Selective Laser Melting (SLM) are novel but complex near net shape fabrication methods. The present paper describes properties of metallic specimens generated by SLM. Therefore various process parameters were observed to evaluate their influence on certain attributes of parts fabricated by Selective Laser Melting. In addition, approaches for an improvement of density, surface quality and mechanical properties are given.
Hybrides Walzen am Beispiel von Titan‐Aluminium‐Verbunden
Authors: Bach Fr.‐ W. , Bormann D. , Rodmann M. , Haverkamp H.
Published: September 2008

Dreilagige Titan‐Aluminiumverbunde aus den Titanlegierungen TiAl6V4 (ASTM grade 5) und Ti 99,8 (ASTM grade 1) sowie den Aluminiumlegerungen Al Mg Si0,5 (EN‐AW 6060) und AlCuMg1 (EN‐AW 2017) werden durch Warmwalzen hergestellt und das Umformverhalten unter unterschiedlichen Umformparametern betrachtet. Schwerpunkt ist die Untersuchung der Unterschiede zwischen schrittweiser und kontinuierlicher Erhöhung des Umformgrades. Getestet werden Umformgrade von 20…60 % bei Temperaturen von 400…500 °C. Anschließend wird die Kontaktzone der hergestellten Verbunde metallographisch untersucht und die Haftfestigkeit der Schichten mechanisch geprüft. Zur qualitativen Bestimmung der Haftfestigkeit des Verbundes werden Torsionsversuche vorgestellt. Der Beginn des Haftungsaufbaus stellt sich bereits bei Umformgraden von 35 % und Temperaturen von 350 °C im Walzspalt ein.
Wirkmedienbasierte Herstellung hybrider Metall‐Kunststoff‐Verbundbauteile mit Kunststoffschmelzen als Druckmedium
Authors: Hussain M. M. , Rauscher B. , Tekkaya A. E.
Published: September 2008

Im Rahmen der durchgeführten Arbeiten wurde eine innovative Verfahrensalternative zur Herstellung hybrider Metall‐Kunststoffbauteile untersucht. Gegenstand ist die Kombination des Kunststoff‐Spritzgießprozesses mit Blech‐ bzw. Profilumformtechnologien. Im Zuge der Umformung von Dom‐ und Napfgeometrien aus Aluminium‐ und Stahlwerkstoffen wurden grundlegende Prozessparameter wie Spritzgießdruck, Volumenstrom gemessen und die hergestellten Bauteile hinsichtlich ihrer Geometrie und Formänderungsverteilung untersucht.
Dynamic analysis of the micromilling process – influence of tool vibrations on the quality of microstructures
Authors: Baschin A. , Kahnis P. , Biermann D.
Published: September 2008

Micromilling is a suitable technique for the manufacturing of microstructured parts. The downscaling of the milling process leads to problems, which are caused by the low stability of microtools and their manufacturing. Tool vibrations and runout occur, resulting in poor surface qualities and undesirable surface location errors. The presented results of the experimental analysis include a stability diagram for the spindle speed range of n = 60,000–120,000 rpm and tool vibrations measured in the xy‐plane. Micrographs illustrate the influence of tool vibrations on the quality of the generated surface structures. In addition, the dynamic runout is characterized and its effects are discussed.
Diffusionslöten von Aluminium mittels PVD applizierter Lotzusatzwerkstoffe
Authors: Tillmann W. , Wojarski L. , Liu C. , Osmanda A. M.
Published: September 2008

Das Diffusionslöten mit Lotbestandteilen beschichteter Aluminium und Aluminiumlegierungen ermöglicht eine flussmittelfreie Herstellung von Lötverbindungen hoher Festigkeit bei moderaten Löttemperaturen. Die über den vorangegangenen Arc‐PVD‐Prozess auf der Oberfläche abgeschiedenenen Lotbestandteile lassen infolge der Diffusionvorgänge im anschließenden Diffusionslötprozess lokal eine Flüssigphase (transient liquid phase) entstehen. Diese bildet sich aus dem Schichtmaterial und dem Grundwerkstoff und erstarrt isotherm infolge der voranschreitenden Diffusionsvorgänge, so dass Verbunde mit einer höheren Wiederaufschmelztemperatur als der Löttemperatur realisiert werden können. In dieser Arbeit wurden die beiden Lotsysteme Al‐Cu und Al‐Cu‐Si für die Anwendung innerhalb dieses hybriden Fügeprozesses evaluiert. Cu bzw. Al‐Cu‐Si sind dabei über den Arc‐PVD‐Prozess auf die Grundwerkstoffoberfläche abgeschieden worden. Als Grundwerkstoffe kamen reines Aluminium und EN‐AW6060 zur Anwendung. Metallographische und rasterelektronenmikroskopische Untersuchungen haben ergeben, dass die Fügezone nach Abschluss des Diffusionslötprozesses eine dem Grundwerkstoff ähnelnde Zusammensetzung aufweist.
Molecular and functional imaging of breast cancer
Authors: Glunde K. , Jacobs M. A. , Pathak A. P. , Artemov D. , Bhujwalla Z. M.
Published: September 2008

Despite several major advances in breast cancer diagnosis and treatment, the American Cancer Society has estimated that in the US alone 43 300 women and 400 men will die from breast cancer in 2007. Breast cancer typically is a multi‐focal, multi‐faceted disease, with the major cause of mortality being complications due to metastasis. Whereas a decade ago genetic alterations were the primary focus in cancer research, it is now apparent that the physiological tumor microenvironment, interactions between cancer cells and stromal cells such as endothelial cells, fibroblasts and macrophages, the extracellular matrix, and a multitude of secreted factors and cytokines influence progression, aggressiveness, and response of the disease to treatment. Prevention, early diagnosis, and treatment are the three broad challenges for MR molecular and functional imaging in reducing mortality from this disease. Multi‐parametric molecular and functional MRI provides unprecedented opportunities for identifying novel targets for imaging and therapy at the bench, as well as for accurate diagnosis and monitoring response to therapy at the bedside. Here we provide an overview of the current status of molecular and functional MRI of breast cancer, outlining some key developments, as well as identifying some of the important challenges facing this field in the future. Copyright © 2008 John Wiley & Sons, Ltd.
PGD on a recombinant allele: crossover between the TSC2 gene and ‘linked’ markers impairs accurate diagnosis
Authors: Altarescu Gheona , Eldar Geva Talia , Brooks Barry , Margalioth Ehud , Levy‐Lahad Ephrat , Renbaum Paul
Published: September 2008

Objective

Accounting for possible recombinations in developing an accurate preimplantation genetic diagnosis (PGD) protocol based on familial haplotypes.

Methods

Haplotypes were constructed from genomic DNA in a family where the male was affected with tuberous sclerosis complex (TSC). Embryos were biopsied at day 3, and single blastomeres were analyzed by multiplex polymerase chain reactions (PCRs) including multiple microsatellite markers and single‐cell sequencing.

Results

Informative markers used in the initial haplotype analysis, based on the genomic DNA of the parents and affected child, were analyzed in the first PGD cycle. All embryos appeared to show recombination and none were transferred. Prior to the next cycle, the parents of the affected male were included in the haplotype analysis, demonstrating that the affected child had a recombinant allele. In the second PGD cycle, two nonrecombinant intragenic single nucleotide polymorphisms (SNPs) were used with the TSC2 mutation and four microsatellite markers for a second PGD cycle. In this cycle two wild‐type embryos were transferred, resulting in the birth of a healthy girl carrying the wild‐type TSC2 allele.

Conclusions

PGD analysis requires the use of more than one meiosis for constructing accurate haplotypes. Testing for multiple closely linked markers and the familial mutation are necessary to detect recombination events and enable precise diagnosis. Copyright © 2008 John Wiley & Sons, Ltd.
Rapid prenatal diagnosis using uncultured amniocytes and oligonucleotide array CGH
Authors: Bi Weimin , Breman Amy M. , Venable Susan F. , Eng Patricia A. , Sahoo Trilochan , Lu Xin‐Yan , Patel Ankita , Beaudet Arthur L. , Cheung Sau Wai , White Lisa D.
Published: September 2008

Objective

Oligonucleotide‐based array comparative genomic hybridization (array CGH) is an established method for detecting chromosomal abnormalities. Here, we explored the feasibility of using DNA extracted from uncultured amniocytes in amniotic fluid for array CGH on an oligonucleotide array platform.

Methods

Fifteen fetuses from 14 ongoing pregnancies were studied by array CGH on targeted oligonucleotide arrays with DNA isolated from direct amniotic fluid using a modified DNA extraction protocol.

Results

High‐quality array CGH results were obtained for 13 samples with suboptimal but interpretable results in only 2 samples due to limited DNA amounts. Array CGH using whole genome amplification (WGA) of DNA for the two cases with limited DNA was successful, and results were consistent with those from unamplified DNA. For another five samples, the results of array CGH with amplified DNA matched those with unamplified DNA. Chromosome analysis was performed for 14 cases and was consistent with array CGH results.

Conclusion

This study demonstrates the feasibility of prenatal genetic diagnosis using oligonucleotide array CGH analysis for direct analysis of amniocytes without culturing cells. The use of oligonucleotide arrays increases the sensitivity and accuracy of detection over previous bacterial artificial chromosome (BAC)‐based arrays. Furthermore, the direct analysis allows for rapid array CGH results and shorter reporting time. Copyright © 2008 John Wiley & Sons, Ltd.
Gene expression in chorionic villous samples at 11 weeks' gestation from women destined to develop preeclampsia
Authors: Farina Antonio , Sekizawa Akihiko , De Sanctis Paola , Purwosunu Yuditiya , Okai Takashi , Cha Dong Hyun , Kang Jin Hee , Vicenzi Claudia , Tempesta Annalisa , Wibowo Noroyono , Valvassori Luisella , Rizzo Nicola
Published: September 2008

Objective

To evaluate the direct alterations in mRNA expression among chorionic villous samples from 11 weeks' pregnant women who would develop preeclampsia (PE) later in the pregnancy.

Method

Case‐control study encompassing five women destined to develop PE [cases matched 1:5 for gestational age (GA) with 25 controls]. We quantified mRNA expression on tissue samples from chorionic villous sampling (CVS) of normal and PE patients. We then assessed mRNA expressions of vascular endothelial growth factor (VEGFA), VEGFA receptor 1 (Flt‐1), endoglin (Eng), placental growth factor (PlGF), transforming growth factor‐β1 (TGF‐β1), heme oxygenase‐1 (HO‐1) and superoxide dismutase (SOD). Data were analyzed by nonparametric rank analysis.

Results

For all the mRNA species considered in this study, all the mean observed ranks in the PE group were significantly altered compared to the rank expectation among controls. mRNA for Eng and TGF‐β1 were the markers with the highest degree of aberration in PE, in respect to controls. The results are consistent with those already reported for the corresponding circulating proteins. mRNA for HO‐1 and SOD were instead associated with the lowest aberration.

Conclusion

It is assumed that the pathogenesis of PE is associated with pathophysiological alterations to trophoblasts in early gestation. Our study has directly proved that gene expressions relating to angiogenesis or oxidative stress are altered in the first trimester trophoblasts that go on to develop PE later. These results would put the basis for a possible screening method for PE by using residual CVS. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation and characterization of nanoparticulate poly(N‐isopropylacryl‐ amide) hydrogel for the controlled release of anti‐tumour drugs
Authors: Blanco M Dolores , Guerrero Sandra , Teijón César , Olmo Rosa , Pastrana Lorenzo , Katime Issa , Teijón José M
Published: September 2008

BACKGROUND: Poly(N‐isopropylacrylamide) (PNIPA) nanohydrogels were synthesized by inverse microemulsion to be used for the controlled release of anti‐tumour drugs. Different methods were used to obtain drug‐loaded xerogels, and their effect on drug release was studied, and evaluated using mathematical modelling.

RESULTS: Nanoparticulate hydrogels, with a z‐average diameter of 170 nm, were loaded with 5‐fluorouracil (5‐FU), methotrexate (MTX) or mitomycin C (MMC) by using spray drying (SD) and freeze drying (FD). Xerogels obtained by SD consisted of individual and independent particles, whereas particles established interactions in xerogels obtained by FD. Total drug release took place at 6 and 7 h from 5‐FU‐loaded and MMC‐loaded xerogels prepared by SD, whereas MTX was expelled from the xerogels formed using the SD process. Drug release was slower from xerogels prepared by FD: 5‐FU at 32 h, MMC at 120 h and MTX at 240 h. The Higuchi model most aptly fits the dissolution data. Non‐Fickian and Fickian release behaviour can be attributed to SD and FD formulations, respectively.

CONCLUSION: The amount of drug loaded, the morphology of xerogels as well as the drug release characteristics not only depend on the drug but also mainly on the process used to obtain the drug‐loaded PNIPA xerogels. Copyright © 2008 Society of Chemical Industry
Novel microporous poly(vinylidene fluoride)‐graft‐poly(tert‐butyl acrylate) electrolytes for secondary lithium batteries
Authors: Kader M Abdul , Kwak Soo Kyoung , Kang Seong Lak , Ahn Jou‐Hyeon , Nah Changwoon
Published: September 2008

BACKGROUND: Much interest has recently been shown in improving the performance of lithium‐ion polymer batteries with gel polymer electrolytes (GPEs) due to a rapid expansion in industrial demand. Novel GPEs based on poly(vinylidene fluoride)‐graft‐poly(tert‐butyl acrylate) (PVDF‐g‐tBA) microporous mats are suggested in this study.

RESULTS: Microfibrous polymer electrolytes were prepared using electrospinning and characterized for extent of grafting, morphology, crystallinity, electrochemical stability, ionic conductivity, interfacial resistance and cell cycleability. The degree of crystallinity was lower for tBA‐grafted PVDF mats than that of neat PVDF. The PVDF‐g‐tBA showed an improvement in the ionic conductivity, electrochemical stability, interfacial resistance and cyclic performance.

CONCLUSION: The tBA‐grafted PVDF microporous electrolytes are promising candidates for enhancing the performance of lithium‐ion polymer batteries. Copyright © 2008 Society of Chemical Industry
Successive solution fractionation mechanisms for high‐density polyethylene
Authors: Stéphenne Vincent , Bailly Christian , Berghmans Hugo , Daoust Daniel , Godard Pierre
Published: September 2008

BACKGROUND:Preparative fractionation techniques are currently used in order to obtain large amounts of polyethylene fractions. Preparative successive solution fractionation (SSF) and temperature rising elution fractionation (TREF) are compared as regards obtaining, at a multi‐gram scale, low‐dispersity fractions of high‐density polyethylene (HDPE). The operative separation mechanisms during a SSF of a broad HDPE, which are not yet totally elucidated, are also studied in this work.

RESULTS:SSF and TREF approaches lead to the separation of HDPE macromolecules according to their molar masses. If very homogeneous fractions (dispersities from 1.1 to 1.3) are isolated in TREF at the lowest elution temperature, the collected mass is too low. At higher elution temperatures, the fractions have too broad a molar mass distribution (dispersities from 2.7 to 3.7). With the SSF procedure, dispersities are not as low as for the first TREF fractions. But, the relative weight fraction is better distributed between the different extraction temperatures. The molar mass distribution exhibits a dispersity of around 1.9.

CONCLUSION:The SSF method is the most suitable way to obtain large gram amounts of low‐dispersity (ca2) HDPE fractions over a wide molar mass range. Complementary gram‐scale rheological characterization is thus possible enabling a better comprehension of the SSF mechanism. Liquid–liquid demixing is the main mechanism in SSF, but its relative importance depends on polymer characteristics and solvent quality. Copyright © 2008 Society of Chemical Industry
Polyimide films with antibacterial surfaces from surface‐initiated atom‐transfer radical polymerization
Authors: Li Liang , Ke Zhenjiang , Yan Guoping , Wu Jiangyu
Published: September 2008

BACKGROUND: Materials with antibacterial surface properties have attracted extensive scientific interest for research and development in the battle against microbial contamination. The application of antimicrobial polymers minimizes environmental problems and enhances the efficiency, selectivity and lifetime of the antimicrobial agents. In this paper polyimide (PI) films are chosen as the polymeric substrate to be modified due to the good thermal, mechanical and physicochemical properties of PI. The method of preparing PI films with antibacterial surfaces using surface‐initiated atom‐transfer radical polymerization (ATRP) is described.

RESULTS: The results from X‐ray photoelectron spectroscopy showed that the surfaces at each stage were modified successfully. The pyridinium groups introduced on the PI surface possessed antibacterial properties and the bactericidal effect of the functionalized PI films on Escherichia coli was evaluated. Quaternization of the pyridine rings of the poly(4‐vinylpyridine) (P4VP) brushes gave rise to a high concentration of quaternary pyridinium groups on the PI film surfaces. The antibacterial efficiency of the modified PI film was dependent on the amount of quaternary pyridinium groups on the surface.

CONCLUSION: In this research, functional polymer brushes of P4VP were prepared via surface‐initiated ATRP from PI films, followed by alkylation of the grafted P4VP with hexyl bromide. The surface functionalization method described has the advantage of being effective in conferring antibacterial properties on polymeric materials. Copyright © 2008 Society of Chemical Industry
Effect of montmorillonite modification on the behaviour of polyamide/polystyrene blends
Authors: Kelnar Ivan , Rotrekl Jakub , Kotek Jiří , Kaprálková Ludmila
Published: September 2008

BACKGROUND: In nanocomposites with multiphase matrices, the addition of layered silicate not only has a reinforcing effect, but also changes significantly the morphology, namely the size and the structure of the dispersed phase. In this paper, we focus on systems with polyamide 6 (PA6)/polystyrene (PS) matrices. The effect of clay was studied over the whole composition range together with the simultaneous variation of basic parameters influencing the structure and mechanical behaviour, i.e. the clay treatment type and mixing protocol.

RESULTS: At all compositions, remarkable refinements of both particulate and co‐continuous structures by clay were found. This effect and a significant shift of the glass transition temperature of blend components were more pronounced for clay with less polar treatment as a result of distinct localization of clay in the interfacial area (due to its lower affinity for PA6 phase). An increase in modulus was found at all compositions, whereas strength and toughness were enhanced at low PS contents only, as a consequence of small particle size and enhanced interfacial bonding.

CONCLUSIONS: The results presented indicate that nanosilicates can effectively influence the structure and properties of PA6/PS blends. Copyright © 2008 Society of Chemical Industry
Comparative proteomic analysis of human placenta derived from assisted reproductive technology
Authors: Zhang Yu , Zhang Yan‐Ling , Feng Chun , Wu Yan‐Ting , Liu Ai‐Xia , Sheng Jian‐Zhong , Cai Jie , Huang He‐Feng
Published: September 2008

The aim of this study was to use proteomics‐based approach to examine differences in protein expression in placenta derived from assisted reproductive technology (ART) and normal pregnancy. Using 2‐DE we found that, compared with the control group, 12 spots in standard in vitro fertilization group and 18 spots in intracytoplasmic sperm injection group were identified as significantly differentially expressed proteins. Among them, six spots were differentially expressed in both standard IVF and ICSI groups with the same change tendency. Totally, 20 proteins were successfully identified by MALDI TOF/TOF MS, including proteins involved in the membrane traffic, metabolism, nucleic acid processing, stress response and cytoskeleton. Notably, five proteins detected to be differentially expressed in both ART groups were identified as annexin A3, hnRNP C1/C2, α‐SNAP, FTL and ATP5A. Some of the proteins were confirmed by Western blot and immunohistochemistry analysis. Our study allowed for the initial identification of these proteins related to various functions in placentation with significantly altered abundance in ART groups. The present results reveal that abnormal protein profiles are involved in ART placenta and these differentially expressed proteins may be valuable for the evaluation of potential association between ART treatment and offspring outcome.
Synthesis and evaluation of new thienyl and bithienyl‐bis‐indolylmethanes as colorimetric sensors for anions
Authors: Batista Rosa M. F. , Oliveira Elisabete , Nuñez Cristina , Costa Susana P. G. , Lodeiro Carlos , Raposo M. Manuela M.
Published: September 2008

The synthesis and full characterization of new bis‐indolylmethanes containing thienyl and bithienyl moieties are reported. The sensor ability of the compounds in the presence of halide ions (F−, Cl−, Br−, and I−), NO, ClO, SO, CN−, and OH− ions was investigated in acetonitrile. The experimental results indicate that they could act as selective chromogenic‐sensing molecules for the most basic anions F−, CN−, and OH−, as a well‐defined color change from yellow to pink was observed. The interaction constants between compounds 1 and 2 in the presence of F−, CN−, and OH− were calculated and increased in the order OH− > F− > CN−. Copyright © 2008 John Wiley & Sons, Ltd.
Evolution of iron catalysts for effective living radical polymerization: P–N chelate ligand for enhancement of catalytic performances
Authors: Uchiike Chihiro , Ouchi Makoto , Ando Tsuyoshi , Kamigaito Masami , Sawamoto Mitsuo
Published: September 2008

Iron catalysts were evolved for more active transition metal‐catalyzed living radical polymerization through design of the ligands. In situ introduction of P–N chelate‐ligands, consisting of hetero‐coordinating atoms [phosphine (P) and nitrogene (N)], onto FeBr2 effectively catalyzed living radical polymerization of methyl methacrylate (MMA) in conjunction with a bromide initiator, where the monomer‐conversion reached over 90% without dropping the rates and the molecular weights of obtained PMMAs were well controlled. The benign effects of the “hetero‐chelation” were demonstrated by comparative experiments with homo‐chelate ligands (P–P, N–N), model compounds of the composed coordination site, and the combinations. We successfully achieved an isolation of iron complex with a P–N ligand [FeBr2(DMDPE); DMDPE: (R)‐N,N‐dimethyl‐1‐(2‐(diphenylphosphino)phenyl)‐ethanamine], which was superior to the conventional catalyst [FeBr2(Pn‐Bu)2] with respect to controllability and activity, especially at the latter stage. The catalyst was almost quantitatively removed by water washing after polymerization. It was also effective for living polymerization of styrene. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6819–6827, 2008
Organic solvent dispersion of poly(3,4‐ethylenedioxythiophene) with the use of polymeric ionic liquid
Authors: Kim Tae Young , Lee Tae Hee , Kim Jong Eun , Kasi Rajeswari M. , Sung Chong S. P. , Suh Kwang S.
Published: September 2008

A nonaqueous dispersion of poly(3,4‐ethylenedioxythiophene) (PEDOT) was prepared with the use of polymeric ionic liquid (PIL) as a polymerization template and phase transfer medium. A detailed investigation was performed to understand the role of PIL in the course of polymerization and phase transfer reaction. On the basis of our findings from X‐ray photoelectric spectroscopy (XPS), we propose a mechanism by which the PIL leads to the nanostructured PEDOT colloids in various organic solvents and thus facilitating smoother surface morphologies of the PEDOT‐PIL films. In addition, the enhancement of charge transport was observed for PEDOT‐PIL complex when compared with PEDOT without PIL. Raman spectroscopy indicates that there is a reduced interaction between the charge carriers on the PEDOT and the counter ions bound to PIL, thus promoting charge carrier hopping rates. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6872–6879, 2008
Synthesis and characterization of nanomagnetite thermosets based on benzoxazines
Authors: Kiskan Baris , Demirel A. Levent , Kamer Orhan , Yagci Yusuf
Published: September 2008

Nanomagnetite thermosets were obtained by thermally activated ring opening copolymerization of benzoxazine groups coated on the surface of the nanomagnetite with bare benzoxazine. For this purpose, carboxylic acid containing 1,3‐benzoxazine was synthesized and covalently bonded on magnetite nanoparticles by postcoating method. The average size of benzoxazine coated nanoparticles was 40–100 nm as determined by Dynamic Light Scattering (DLS), Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) measurements. The crystal structure of benzoxazine coated nanoparticles was shown to be magnetite by X‐ray diffraction (XRD) analysis. Thermally activated curing behavior of nanomagnetite‐benzoxazines has also been studied by differential scanning calorimetry (DSC). Magnetic and thermal properties of the cured samples were investigated. It was shown that the precursor nanomagnetite benzoxazine and cured samples exhibited typical ferromagnetic character with low coercivities between 1.5 and 2.5 Oe. The cured samples showed high thermal stability. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6780–6788, 2008
Access to evidence (2): how to construct your search effectively
Authors: Dex Grant
Published: September 2008

By following a simple four‐step approach to evidence‐based medicine, practitioners can ‘pull’ answers out of the literature to inform clinical decision‐making. Here, Dr Dex guides us through the process using examples and mnemonics. Copyright © 2008 Wiley Interface Ltd
Environmental context, managerial cognition, and strategic action: an integrated view
Authors: Nadkarni Sucheta , Barr Pamela S.
Published: September 2008

This study addresses an apparent disconnect between two views of strategic action: the ‘economic view,’ which contends that industry structure is the primary influence on strategic action, and the ‘cognitive view,’ which suggests that managerial cognition drives strategic action. We argue that this disconnect has created artificial boundaries between the two perspectives and has limited our ability to develop holistic explanations of strategic action. In response, we develop an integrated model that answers two questions: 1) Does industry context affect managerial cognition? 2) Does managerial cognition mediate the relationship between industry context and strategic responses to environmental changes? To examine these questions, we study the relationship between industry velocity, the structure of top management's cognitive representation of the environment, and the speed of response to environmental events. We find that industry velocity influences the structure of cognitive representations, which in turn influence the speed of response to environmental events. These results support our contention that both industry and cognition variables are critical in developing explanations of strategic actions. These results have implications for our understanding of the development of top managers' beliefs, the relationship between beliefs and action, and the nature of the complex relationship between industry context, managerial cognition, and strategic action. Copyright © 2008 John Wiley & Sons, Ltd.
Envy, comparison costs, and the economic theory of the firm
Authors: Nickerson Jack A. , Zenger Todd R.
Published: September 2008

An economic theory of the firm must explain both when firms supplant markets and when markets supplant firms. While theories of when markets fail are well developed, the extant literature provides a less than adequate explanation of why and when hierarchies fail and of actions managers take to mitigate such failure. In this article, we seek to develop a more complete theory of the firm by theorizing about the causes and consequences of organizational failure. Our theory focuses on the concept of social comparison costs that arise through social comparison processes and envy. While transaction costs in the market provide an impetus to move activities inside the boundaries of the firm, we argue that envy and resulting social comparison costs motivate moving activities outside the boundary of the firm. More specifically, our theory provides an explanation for ‘managerial’ diseconomies of both scale and scope—arguments that are independent from traditional measurement, rent seeking, and competency arguments—that provides new insights into the theory of the firm. In our theory, hierarchies fail as they expand in scale because social comparison costs imposed on firms escalate and hinder the capacity of managers to optimally structure incentives and production. Further, hierarchy fails as a firm expands in scope for the simple reason that the costs of differentially structuring compensation within the firm to match the increasing diversity of activities also rises with increasing scope. In addition, we explore how social comparison costs influence the design of the firm through selection of production technologies and compensation structures within the firm. Copyright © 2008 John Wiley & Sons, Ltd.
Bigger and safer: the diffusion of competitive advantage
Authors: Greve Henrich R.
Published: September 2008

Research on the diffusion of technologies that give competitive advantage is needed to understand the role of technology in competition. Predictions on which firms first obtain useful technologies are made by cluster theory, which holds that the diffusion is geographically bounded, and network theory, which holds that adoption is more rapid in central network positions. These predictions can be evaluated using data on the diffusion of supplier innovations that give competitive advantage to firms in the buyer industry. Here, the diffusion of new ship types is studied using the heterogeneous diffusion model and data on shipping firm‐shipbuilder networks, showing that valuable innovations remain rare because they are not adopted by distant firms in geographical and network space. The strong influence of geographically dispersed interfirm networks on technology diffusion justifies a greater role of interorganizational networks in the theory of competitive advantage. Copyright © 2008 John Wiley & Sons, Ltd.
Why firms make unilateral investments specific to other firms: the case of OEM suppliers
Authors: Kang Min‐Ping , Mahoney Joseph T. , Tan Danchi
Published: September 2008

This study examines why and under what conditions firms will make unilateral relationship‐specific investments to their transaction partners. We propose that firms are more likely to make such investments when the investment yields positive economic spillover values for other transactions with the same exchange partners as well as for third‐party transactions. We also model two types of positive inter‐project spillover effects that a transaction may generate: knowledge spillovers and reputation spillovers. We find empirical support for our developed theory in the context of Taiwanese suppliers of original equipment manufacturers. Copyright © 2008 John Wiley & Sons, Ltd.
Reliability of three‐dimensional sonographic measurements in early pregnancy using virtual reality
Authors: Verwoerd‐Dikkeboom C. M. , Koning A. H. J. , Hop W. C. , Rousian M. , Van Der Spek P. J. , Exalto N. , Steegers E. A. P.
Published: September 2008

Objective

To establish the reliability of three‐dimensional (3D) ultrasound measurements in early pregnancy using a virtual reality system (the Barco I‐Space).

Methods

The study included 28 pregnancies with gestational ages ranging from 6 to 14 (median, 10) weeks. 3D volumes were acquired and offline measurements were made, where possible, of the yolk sac diameter, crown–rump length, biparietal diameter, head circumference and abdominal circumference, using specialized 3D imaging software (4DView). The datasets were then transferred to the Barco I‐Space, a virtual reality system that allows the observer to perceive depth and interact with volume‐rendered (ultrasound) data. The 3D rendered volumes were measured using a virtual pointer, controlled by a wireless joystick. For intraobserver variability, 3D and virtual reality volumes were measured twice by one operator. For interobserver variability, another operator performed the same measurements once. All measurements were repeated three times and their mean values were used for comparisons.

Results

All intraclass correlation coefficients (ICCs) comparing 4DView measurements with I‐Space measurements were > 0.97. Intra‐ and interobserver ICCs for the 4DView measurements were > 0.96 and for the I‐Space ones were > 0.98, representing good agreement.

Conclusions

The application of virtual reality is a novel method of visualizing 3D ultrasound data and perception of the depth in the I‐Space offers possibilities for measuring non‐planar structures. We have demonstrated that early pregnancy measurements in the I‐Space are reliable. New areas of embryonic and fetal biometry can now be explored using this technique, which we tentatively name ‘virtual embryoscopy’. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal prediction of survival in isolated diaphragmatic hernia using observed to expected total fetal lung volume determined by magnetic resonance imaging based on either gestational age or fetal body volume
Authors: Cannie M. , Jani J. , Meersschaert J. , Allegaert K. , Done' E. , Marchal G. , Deprest J. , Dymarkowski S.
Published: September 2008

Objectives

To compare the predictive value of the prenatal observed to expected (o/e) lung volume as measured by fetal magnetic resonance imaging (MRI), based on an algorithm using either the gestational age or fetal body volume (FBV), for neonatal survival of fetuses with isolated congenital diaphragmatic hernia (CDH).

Methods

We included 53 fetuses with a prenatal diagnosis of isolated CDH, 26 without and 27 with prenatal tracheal occlusion, who were assessed by fetal MRI, liveborn after 32 weeks, and in whom follow‐up until discharge from the neonatal care unit was available. Measurements of lung volumes were expressed as a percentage of the appropriate mean (o/e total fetal lung volume (TFLV) × 100) either for gestational age or for FBV. Measurements of FBV were expressed as a percentage of the appropriate mean (o/e FBV × 100) for gestation. Fetuses with prenatal intervention were all assessed ≥ 24 h after balloon removal. Regression analysis was used to examine the effect on postnatal survival of either o/e TFLV based on gestational age or based on FBV, gestation at delivery, side of CDH, intrathoracic position of the liver and prenatal intervention. Receiver–operating characteristics (ROC) curves were constructed for the prediction of survival by o/e TFLV based on gestational age and o/e TFLV based on FBV, for all fetuses, as well as for those with o/e FBV between 90 and 110% and those with values beyond that range. A power calculation for the number of fetuses needed to show a difference between the ROC curves was performed.

Results

Regression analysis demonstrated that o/e TFLV based on gestational age and on FBV were the only independent predictors of postnatal survival. The area under the ROC curve for prediction of postnatal survival from the o/e TFLV based on gestational age was 0.811, and for that based on FBV it was 0.868 (P < 0.001 for both). For fetuses with o/e FBV between 90 and 110%, and those with values < 90% and > 110%, the area for measurements based on gestational age was 0.895 and 0.733, respectively; when based on FBV it was 0.906 and 0.833 (P < 0.01 for all). A minimum of 273 patients would be needed to provide a probability of 90% of detecting a difference between the areas under both ROC curves.

Conclusions

In fetuses with isolated CDH, lung volume as measured by fetal MRI was significantly correlated with survival. Prediction tended to be better by o/e TFLV based on FBV rather than gestational age. The difference in the prediction of survival between o/e TFLV based on FBV or gestational age was dependent on fetal biometry. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Mitigation of colluding route falsification attacks by insider nodes in mobilead hocnetworks
Authors: Su Xu , Boppana Rajendra V.
Published: September 2008

Colluding malicious insider nodes with no special hardware capability can use packet encapsulation and tunneling to create bogus shortcuts (in‐band wormholes) in routing paths and influence data traffic to flow through them. This is a particularly hard attack using which even a handful of malicious nodes can conduct data traffic analysis of packets or disrupt connections by dropping packets when needed. Simulation analysis shows that a disproportionately large amount of traffic goes through routes with wormholes even when a secure routing protocol (SRP) such as Ariadne is used. To mitigate such attacks and augment existing on demand SRPs, distributed packet filtering techniques based on statistical profiling of control packet propagation speeds are proposed. These techniques do not require network‐wide synchronized clocks or new packet transmissions and need only simple computations by the sources or the destinations of the connections. The proposed packet filters together with Ariadne are implemented in the Glomosim simulator and their effectiveness is evaluated. The simulation results indicate that the proposed packet filters can reduce the in‐band wormhole creation and their usage by a factor of 2‐‐10. Also, the false alarm rates of the proposed techniques are very low and have little impact on normal network throughput, making them practical for mobilead hocnetworks. Copyright © 2008 John Wiley & Sons, Ltd.
Perineural Invasion Is a Prognostic Factor in Intrahepatic Cholangiocarcinoma
Authors: Shirai Kazuhisa , Ebata Tomoki , Oda Koji , Nishio Hideki , Nagasaka Tetsuro , Nimura Yuji , Nagino Masato
Published: September 2008

Background

Perineural invasion is commonly observed in biliary tract cancer and is an independent prognostic factor. Since intrahepatic cholangiocarcinoma (ICC) develops from biliary epithelia in the liver, ICC may share the same characteristics in terms of the prognostic implications of perineural invasion. The aim of this study was to evaluate the clinical significance of perineural invasion in ICC.

Methods

A total of 59 patients with ICC who underwent hepatectomy were retrospectively reviewed. The numbers of nerves with and without tumor involvement were counted. The perineural invasion index (PNI) was calculated as the number of involved nerves divided by the total number of nerves examined. Predictors for perineural invasion and prognostic factors were analyzed.

Results

Perineural invasion was observed in 47 of 59 (80%) patients, and the median PNI was 0.082. The macroscopic tumor appearance and tumor location were significantly associated with perineural invasion (p = 0.013 and 0.032, respectively). Univariate and multivariate analyses (excluding seven in‐hospital deaths) revealed that histologic grade, the presence of perineural invasion, nodal metastasis, and intrahepatic metastasis were independent prognostic factors. The survival rate of the patients with (n = 42) or without (n = 10) perineural invasion was 17 and 80% at 3 years; and 17 and 70% at 5 years, respectively (p = 0.001).

Conclusion

Perineural invasion is frequently found in patients with ICC and is an independent prognostic factor. ICC is an aggressive tumor similar to other biliary tract cancers. Because perineural invasion is a histologic marker of aggressiveness, it potentially has a role as a determinant of patient selection for adjuvant therapy.
The Use of Magnetic Anchors in the Bowel Lumen for Laparoscopic Anterior Resection of Rectosigmoid Colon in Pigs: with Video
Authors: Kume Makoto , Miyazawa Hideaki , Iwasaki Wataru , Abe Fukumitsu , Uchinami Hiroshi , Yamamoto Yuzo
Published: September 2008

Background

This article describes a new technique for retracting the rectum upward during laparoscopic surgery using the pulling force created between two magnets.

Methods

A magnet and a colonoscope were inserted into the rectal cavity of a swine model, and a second magnet was placed on the abdominal wall creating a magnetic anchor or retraction that pulled the rectum upward. Subsequently, a laparoscopic anterior resection of the rectosigmoid colon was performed. The magnetic anchor transferred an electromagnetic force through the abdominal wall, creating effective organ retraction without the need of a trocar.

Results

Surgery without the use of trocars allows for increased flexibility in the angle, distance, and location of the retraction. Since retraction was achieved without a shaft device that can impede visibility within the abdominal cavity, the surgeons achieved excellent endoscopic views. Because the intraluminal magnetic anchor was placed directly on the inside wall of the target organ, tracking target organ movement closely with the movement of the extracorporeal control magnet was possible and synchronizing their movements was not difficult.

Conclusion

The technique presented in this article might be less invasive and could provide more effective manageability for laparoscopic surgery.