bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical, morphological, and thermal properties of polypropylene/kaolin composite. Part I. The effects of surface‐treated kaolin and processing enhancement
Authors: Ariffin A. , Mansor A. S. , Jikan S. S. , Mohd. Ishak Z. A.
Published: March 2008

All of the composites were prepared using Brabender internal mixer (50 rpm, 190°C) and molded using compression mold (190°C) to form test samples. The results showed that the tendency of kaolin particles to agglomerate was too strong, resulting in low strength and rigidity but fairly good toughness. To overcome the kaolin agglomerations dilemma, quaternary ammonium compound (QAC), sodium hexametaphosphate (SHMP), sodium hydroxide (NaOH), and polypropylene (PP) grafted maleic anhydride (PPgMAH) surface treatment agents were applied. Better dispersion of kaolin fillers were obtained with reduced size of the agglomerates. It was also found that nonreactive treatments enhanced the toughness of the composite remarkably, because of the softening effect that promotes plastic deformations. QAC was found to be the most effective dispersing agent of kaolin in PP matrix and contributes to 47% increment in the impact strength value compared to the untreated kaolin composite. QAC‐treated kaolin also shows the most remarkable increment in melt flow index (MFI) and degree of crystallization (DOC) beyond other composites. To improve the dispersion and affinity of kaolin fillers to PP matrix, the processing enhancement was conducted at the end of the experiment. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Metal ion retention using the ultrafiltration technique: Preparation, characterization of the water‐soluble poly(1‐vinyl‐2‐pyrrolidone‐co‐itaconic acid) and its metal complexes in aqueous solutions
Authors: Pizarro Guadalupe del C. , Marambio Oscar G. , Jeria‐Orell Manuel , Huerta Margarita R. , Rivas Bernabé L. , Habicher Wolf D.
Published: March 2008

Radical copolymerization of 1‐vinyl‐2‐pyrrolidone with itaconic acid at different feed monomer ratios (75–25 mol %) were investigated. The copolymers were characterized by elemental analysis, Fourier transform infrared (FTIR), 1H and 13C NMR spectroscopy. The copolymer composition was determined from elemental analysis and found to be statistical copolymers. Additionally, viscosimetric measurements, molecular weight, and polydispersity have been determined. The metal complexation of poly(1‐vinyl‐2‐pyrrolidone‐co‐itaconic acid) for the metal ions such as Cr(III), Co (II), Zn(II), Ni(II), Cu(II), Cd(II), and Fe(III) were investigated at pH 3, 5, and 7 in aqueous solution. The metal ion interaction with hydrophilic polymers was determined as a function of the pH and filtration factor. Poly(1‐vinyl‐2‐pyrrolidone‐co‐itaconic acid) showed a high affinity for the metal ions at pH 5 and 7. The poly(NVP‐co‐IA), with a copolymer composition of 29 : 71 mol % (PVA‐3), presented the highest metal ion retention values, particularly at higher pHs, at which the carboxylic acid groups are nonprotonated and could easily coordinate with the metal ions. According to the interaction pattern obtained, Cr(II), Zn(II), Pb(II), and Ni(II) formed the most stable complexes at pH 7. The thermal behaviors of the copolymer and polymer metal complex were characterized using differential scanning calorimetry (DSC) and thermogravimetry techniques under nitrogen atmosphere. The copolymers present high thermal stability and do not present glass transition in DSC curves between 25 and 500°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Preparation and characterization of silver nanoparticles with dendrimers as templates
Authors: Jin Lei , Yang Shi‐Ping , Wu Hui‐Xia , Huang Wei‐Wei , Tian Qi‐Wei
Published: March 2008

In this study, crystal silver nanoparticle clusters, prepared by the reduction of AgNO3 in the presence of third‐to‐sixth‐generation dendrimers with a trimesyl core, were characterized with ultraviolet–visible spectroscopy, transmission electron microscopy, and energy‐dispersive X‐ray spectroscopy. The results showed that the particle size of the silver nanoparticles was considerably affected by the generation of the dendrimers as well as the dendrimer concentration. When the concentration ratios of Ag+ to the third‐to‐sixth‐generation dendrimers were all 4 : 1, the average diameters of the obtained particles were 6.7, 6.0, 5.2, and 4.3 nm, respectively. The data from high‐resolution transmission electron microscopy and electron diffraction indicated that the particles belonged to a simple cubic crystal structure. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Prophenoloxidases 1 and 2 from the spruce budworm, Choristoneura fumiferana: Molecular cloning and assessment of transcriptional regulation by a polydnavirus
Authors: Doucet Daniel , Béliveau Catherine , Dowling Ashley , Simard Jocelyne , Feng Qili , Krell Peter J. , Cusson Michel
Published: March 2008

Immune challenge in arthropods is frequently accompanied by melanization of the hemolymph, a reaction triggered by the activation of prophenoloxidase (PPO). Because their immature stages are spent inside the hemocoel of insect larvae, endoparasitoids have evolved strategies to escape or counter melanin formation. Very little molecular information is available on these endoparasitoid counterstrategies. We have sought to shed light on the inhibition of melanization in the spruce budworm, Choristoneura fumiferana, by the parasitic wasp Tranosema rostrale, by cloning two host PPO homologs and studying their transcriptional regulation after parasitization. The two polypeptides are encoded by transcripts of ˜3.3 kb (for CfPPO1) and 3.0 kb (for CfPPO2) and possess structural features typical of other insect PPOs. While there appears to be a single CfPPO2 gene in the C. fumiferana genome, we detected three CfPPO1 mRNA variants displaying insertions/deletions in the 3′ untranslated region, suggesting that there may be more than one CfPPO1 gene copy. Both CfPPO1 and CfPPO2 were expressed at high levels in C. fumiferana 6th instars, and parasitization by T. rostrale had no apparent impact on the level of their transcripts. Injection of a large dose (0.5 female‐equivalent) of polydnavirus‐laden calyx fluid extracted from T. rostrale, which is known to inhibit melanization in C. fumiferana, only caused a transient decrease in CfPPO1 and CfPPO2 transcript accumulation at 2–3 d post injection. It thus appears that transcriptional downregulation of C. fumiferana PPO by T. rostrale plays a minor role in the inhibition of hemolymph melanization in this host‐parasitoid system. Arch. Insect Biochem. Physiol. 67:188–201, 2008. Published 2008 Wiley‐Liss, Inc.†
Comparison of three methods of parasitoid polydnavirus genomic DNA isolation to facilitate polydnavirus genomic sequencing
Authors: Rodríguez‐Pérez Mario A. , Beckage Nancy E.
Published: March 2008

A major long‐term goal of polydnavirus (PDV) genome research is to identify novel virally encoded molecules that may serve as biopesticides to target insect pests that threaten agriculture and human health. As PDV viral replication in cell culture in vitro has not yet been achieved, several thousands of wasps must be dissected to yield enough viral DNA from the adult ovaries to carry out PDV genomic sequencing. This study compares three methods of PDV genomic DNA isolation for the PDV of Cotesia flavipes, which parasitizes the sugarcane borer, Diatraea saccharalis, preparatory to sequencing the C. flavipes bracovirus genome. Two of these protocols incorporate phenol‐chloroform DNA extraction steps in the procedure and the third protocol uses a modified Qiagen DNA kit method to extract viral DNA. The latter method proved significantly less time‐consuming and more cost‐effective. Efforts are currently underway to bioengineer insect pathogenic viruses with PDV genes, so that their gene products will enhance baculovirus virulence for agricultural insect pests, either via suppression of the immune system of the host or by PDV‐mediated induction of its developmental arrest. Sequencing a growing number of complete PDV genomes will enhance those efforts, which will be facilitated by the study reported here. Arch. Insect Biochem. Physiol. 67:202–209, 2008. © 2008 Wiley‐Liss, Inc.
Persea americana (avocado): bringing ancient flowers to fruit in the genomics era
Authors: Chanderbali André S. , Albert Victor A. , Ashworth Vanessa E.T.M. , Clegg Michael T. , Litz Richard E. , Soltis Douglas E. , Soltis Pamela S.
Published: March 2008

The avocado (Persea americana) is a major crop commodity worldwide. Moreover, avocado, a paleopolyploid, is an evolutionary “outpost” among flowering plants, representing a basal lineage (the magnoliid clade) near the origin of the flowering plants themselves. Following centuries of selective breeding, avocado germplasm has been characterized at the level of microsatellite and RFLP markers. Nonetheless, little is known beyond these general diversity estimates, and much work remains to be done to develop avocado as a major subtropical‐zone crop. Among the goals of avocado improvement are to develop varieties with fruit that will “store” better on the tree, show uniform ripening and have better post‐harvest storage. Avocado transcriptome sequencing, genome mapping and partial genomic sequencing will represent a major step toward the goal of sequencing the entire avocado genome, which is expected to aid in improving avocado varieties and production, as well as understanding the evolution of flowers from non‐flowering seed plants (gymnosperms). Additionally, continued evolutionary and other comparative studies of flower and fruit development in different avocado strains can be accomplished at the gene expression level, including in comparison with avocado relatives, and these should provide important insights into the genetic regulation of fruit development in basal angiosperms. BioEssays 30:386–396, 2008. © 2008 Wiley Periodicals, Inc.
Gene duplications, robustness and evolutionary innovations
Authors: Wagner Andreas
Published: March 2008

Mutational robustness facilitates evolutionary innovations. Gene duplications are unique kinds of mutations, in that they generally increase such robustness. The frequent association of gene duplications in regulatory networks with evolutionary innovation is thus a special case of a general mechanism linking innovation to robustness. The potential power of this mechanism to promote evolutionary innovations on large time scales is illustrated here with several examples. These include the role of gene duplications in the vertebrate radiation, flowering plant evolution and heart development, which encompass some of the most striking innovations in the evolution of life. BioEssays 30:367–373, 2008. © 2008 Wiley Periodicals, Inc.
Silicon nanotechnologies of pigmented heterokonts
Authors: Grachev Mikhail A. , Annenkov Vadim V. , Likhoshway Yelena V.
Published: March 2008

Many pigmented heterokonts are able to synthesize elements of their cell walls (the frustules) of dense biogenic silica. These include diatom algae, which occupy a significant place in the biosphere. The siliceous frustules of diatoms have species‐specific patterns of surface structures between 10 and a few hundred nanometers. The present review considers possible mechanisms of uptake of silicic acid from the aquatic environment, its transport across the plasmalemma, and intracellular transport and deposition of silica inside the specialized Silica Deposition Vesicle (SDV) where elements of the new frustule are formed. It is proposed that a complex of silicic acid with positively charged proteins silaffins and polypropylamines remains a homogeneous solution during the intracellular transport to SDV, where biogenic silica precipitates. The high density of the deposited biogenic silica may be due to removal of water from the SDV by aquaporins followed by syneresis—a process during which pore water is expelled from the network of the contracting gel. The pattern of aquaporins in the silicalemma, the membrane embracing the SDV, can determine the pattern of species‐specific siliceous nanostructures. BioEssays 30:328–337, 2008. © 2008 Wiley Periodicals, Inc.
Wrestling off RAD51: a novel role for RecQ helicases
Authors: Wu Leonard
Published: March 2008

Homologous recombination (HR) is essential for the accurate repair of DNA double‐strand breaks and damaged replication forks. However, inappropriate or aberrant HR can also result in genome rearrangements. The maintenance of cell viability is, therefore, a careful balancing act between the benefits of HR (the error‐free repair of DNA strand breaks) and the potential detrimental outcomes of HR (chromosomal rearrangements). Two papers have recently provided a mechanistic insight into how HR may be tempered by RecQ helicases to prevent genome instability and diseases that are a consequence of this, such as cancer.1,2 BioEssays 30:291–295, 2008. © 2008 Wiley Periodicals, Inc.
Multicellular behavior in bacteria: communication, cooperation, competition and cheating
Authors: Dunny Gary M. , Brickman Timothy J. , Dworkin Martin
Published: March 2008

The sociobiology of bacteria, largely unappreciated and ignored by the microbiology research community two decades ago is now a major research area, catalyzed to a significant degree by studies of communication and cooperative behavior among the myxobacteria and in quorum sensing (QS) and biofilm formation by pseudomonads and other microbes. Recently, the topic of multicellular cooperative behaviors among bacteria has been increasingly considered in the context of evolutionary biology. Here we discuss the significance of two recent studies1,2 of the phenomenon of “cheating” mutants and their exploitation of cooperating microbial populations of Pseudomonas aeruginosa. BioEssays 30:296–298, 2008. © 2008 Wiley Periodicals, Inc.
Child abuse in South Africa: rights and wrongs
Authors: Richter Linda M. , Dawes Andrew R. L.
Published: March 2008

In a country in which human rights feature prominently in our discourse about who we are, as well as in the South African constitutional and legal framework, so many wrongs continue to be done to children. One category of wrongs is abuse, but it is not the only one. Poverty, patriarchy and gender violence, as well as the socialised obedience, dependency and silence of women and children, create conditions in which abuse can occur, often with few consequences. South Africa has extremely high rates of both physical and sexual abuse of children. Progressive, rights‐based legislation exists to protect children, but it is not adequately supported or resourced by services to fulfil their provisions. Child abuse and neglect will not be significantly reduced in South Africa, without simultaneous improvements in the social and economic conditions in which very large numbers of children live. Copyright © 2008 John Wiley & Sons, Ltd.
Changes in calcium‐dependent membrane permeability properties in mitochondria of livers from arthritic rats
Authors: Silva Pamelli Maria de Souza , Tanabe Eduardo , Hermoso Aparecida Pinto Munhos , Bersani‐Amado Ciomar A. , Bracht Adelar , Ishii‐Iwamoto Emy L. , Salgueiro‐Pagadigorria Clairce Luzia
Published: March 2008

The involvement of the mitochondrial permeability transition pore (PTP) in the responses of mitochondria from adjuvant‐induced arthritic rats to Ca2+ addition was investigated. The respiratory activity, the Ca2+‐induced osmotic swelling and the electrophoretic 45Ca2+ uptake were evaluated in the absence and in the presence of cyclosporin A (CsA), a well‐known inhibitor of the mitochondrial PTP. The Ca2+‐induced mitochondrial permeability transition (MPT) process occurred in mitochondria from arthritic rats even in the presence of a low Ca2+ concentration. Whereas in the normal condition, the Ca2+‐induced uncoupling of oxidative phosphorylation and osmotic swelling was observed in the presence of 10 or 20 µM Ca2+ concentration, in the arthritic condition, these events occurred at 1.0 µM concentration. In addition, mitochondria from arthritic rats presented an impaired ability to accumulate 45Ca2+. All these effects were completely prevented by the administration of CsA. The results of the present study suggest that the higher sensitivity of mitochondria from arthritic rats to Ca2+‐induced MPT may be an important factor in the pathogenesis of the arthritis disease. Copyright © 2008 John Wiley & Sons, Ltd.
BimEL‐dependent apoptosis induced in peripheral blood lymphocytes with n‐butyric acid is moderated by variation in expression of c‐myc and p21(WAF1)
Authors: Kalousek Ivan , Brodska Barbora , Otevrelova Petra , Röselova Pavla
Published: March 2008

We have examined the effect of sodium butyrate (SB) on the viability of normal peripheral blood lymphocytes (PBLs) in vitro and the effect of this agent on the expression of 20 apoptosis‐related genes. Data suggest that PBL treated with 2 mmol L−1 SB resisted for at least 8 h the destructive activity of the agent, but eventually 30% of cells died within 72 h. As documented by flow cytometry and cytochrome c release study, cells underwent mitochondrial‐derived apoptosis. While the expression of the majority of genes examined by RT‐PCR and Western blots remained indifferent to 2 mmol L−1 SB, the cellular levels of BimEL, c‐myc, p53, and p21(WAF1) varied profoundly with the time of SB treatment. The Bax activator BimEL increased rapidly, driving cells toward apoptosis likely controlled by c‐myc and p21(WAF1) activities. The c‐myc, exercising the role of mediator of the function of BimEL and inhibitor of p21(WAF1) expression, decreased significantly for several hours after adding SB but within 48 h it returned to close to its original value. An apoptosis inhibitor and executive caspase substrate p21(WAF1) increased early at the beginning of treatment but subsequently, within a time frame of 72 h, profoundly dropped in terms of both a caspase‐dependent and caspase‐independent way. We suggest that variations in c‐myc and p21(WAF1) expression delay apoptosis making PBL resistant to SB for several hours, and together with fast catabolism of SB in vivo protect PBL against the destructive activity of this anti‐cancerous metabolite of colonic bacteria. Copyright © 2008 John Wiley & Sons, Ltd.
A Molecular Dynamics Study of the ASC and NALP1 Pyrin Domains at Neutral and Low pH
Authors: Gattin Zrinka , van Gunsteren Wilfred F.
Published: March 2008

The pyrin domain is one of four subfamilies of the death domain superfamily of proteins, all members of which share a similar three‐dimensional fold with a structure comprising five or six antiparallel α‐helices. The pyrin domain of the ASC (six‐helical fold) and of the NALP1 (five‐helical fold) proteins were simulated at two different pH values, 3.7 and 6.5, with two different force‐field parameter sets, and the molecular dynamics simulation trajectories were compared to NMR experimental data. The two force fields that were used did not show very different results. The simulations of NALP1 at pH 6.5 largely satisfied the experimental NOE atom–atom distance bounds that were measured at pH 6.5, and preserved its tertiary structure. The simulations at pH 3.7 showed a denaturation of the protein. The simulations of ASC at pH 3.7 only satisfied the experimental NOE atom–atom distance bounds that were measured at pH 3.7 if either three acidic side chains (Asp48, Glu64 and Asp75) or only two (Glu64 and Asp75) were not protonated. This indicates that the ASC tertiary structure is stabilized by salt bridges at low pH. A corresponding analysis for NALP1 at pH 3.7 only yielded one possible salt bridge, but this did not stabilize the tertiary structure at low pH. The results show that the particular protonation states of acidic side chains in the protein interior might be crucial to properly modeling these proteins at low pH.
An ESI‐MS/MS Method for Screening of Small‐Molecule Mixtures against Glycogen Synthase Kinase‐3β (GSK‐3β)
Authors: Partserniak Ivan , Werstuck Geoff , Capretta Alfredo , Brennan John D.
Published: March 2008

Glycogen synthase kinase‐3β (GSK‐3β) is involved in the hyperphosphorylation of previously phosphorylated (primed) substrates, and is currently assayed using an approach based on the incorporation of γ‐32P‐radiolabelled isotopes into substrate peptides. The requirement to detect hyperphosphorylation of a primed substrate poses a particular challenge for development of a high‐throughput screening assay, as many current kinase assays are designed to produce a signal in the presence of any phosphorylation site, and thus are only suitable for β‐unphosphorylated substrates. Herein, we have developed an electrospray‐ionization tandem mass spectrometry (ESI‐MS/MS) assay to allow for direct detection of a hyperphosphorylated product which is formed in a solution reaction involving a primed peptide substrate (GSM peptide) and GSK‐3β. Optimum reaction conditions (level of Mg2+, buffer type, ionic strength, pH, enzyme concentration, and reaction time) were established to both maintain the activity of GSK‐3β and allow for substrate and product quantification through ESI/MS/MS. We show that the MS‐based assay allows for rapid determination of GSK‐3β activity from reaction volumes of ∼40 μL and that it can be used to assess IC50 values and the site of action of known inhibitors. It also can be used for automated screening of small‐molecules mixtures to identify inhibitors of GSK‐3β.
Covalent Linkage Mediates Communication between ACP and TE Domains in Modular Polyketide Synthases
Authors: Tran Lucky , Tosin Manuela , Spencer Jonathan B. , Leadlay Peter F. , Weissman Kira J.
Published: March 2008

Polyketide natural products such as erythromycin A and epothilone are assembled on multienzyme polyketide synthases (PKSs), which consist of modular sets of protein domains. Within these type I systems, the fidelity of biosynthesis depends on the programmed interaction among the multiple domains within each module, centered around the acyl carrier protein (ACP). A detailed understanding of interdomain communication will therefore be vital for attempts to reprogram these pathways by genetic engineering. We report here that the interaction between a representative ACP domain and its downstream thioesterase (TE) is mediated largely by covalent tethering through a short “linker” region, with only a minor energetic contribution from protein–protein molecular recognition. This finding helps explain in part the empirical observation that TE domains can function out of their normal context in engineered assembly lines, and supports the view that overall PKS architecture may dictate at least a subset of interdomain interactions.
Internal governance in the community college: Models and quilts
Authors: Miller Michael T. , Miles Jennifer M.
Published: March 2008

This chapter describes the various approaches to internal shared governance utilized by community colleges, ranging from approaches that intentionally involve different constituents to those evolved from habit, tradition, and precedence.
The effect of the community college workforce development mission on governance
Authors: Friedel Janice Nahra
Published: March 2008

This chapter uses Kentucky and Iowa as case studies to identify the contextual factors affecting the relationship between workforce development and state community college governance.
Yanks, Canucks, and Aussies: Governance as liberation
Authors: Levin John S.
Published: March 2008

This chapter offers a three‐nation perspective on college governance, emphasizing the condition of autonomy embedded in governance arrangements.
Governance in strategic context
Authors: Alfred Richard L.
Published: March 2008

Forces inside and outside of community colleges are changing the context for governance and mandating new and different approaches to decision making.
Key resources on community college governance
Authors: Schuetz Pam
Published: March 2008

This chapter offers a selection of references and resources on structures, processes, and outcomes of community college governance.
When did Louis Pasteur present his memoir on the discovery of molecular chirality to the Académie des sciences? Analysis of a discrepancy
Authors: Gal Joseph
Published: March 2008

Louis Pasteur presented his historic memoir on the discovery of molecular chirality to the Académie des sciences in Paris on May 22nd, 1848. The literature, however, nearly completely ignores this date, widely claiming instead May 15th, 1848, which first surfaced in 1922 in Pasteur's collected works edited by his grandson Louis Pasteur Vallery‐Radot. On May 21st, 1848, i.e., one day before Pasteur's presentation in Paris, his mother died in Arbois, eastern France. Informed at an unknown point in time that she was “very ill,” Pasteur left for Arbois only after his presentation. Biographies of Pasteur by his son‐in‐law René Vallery‐Radot or the grandson, and Pasteur's collected correspondence edited by the grandson are incomprehensibly laconic or silent about the historic presentation. While no definite conclusions are possible, the evidence strongly suggests a deliberate alteration of the record by the biographer relatives, presumably for fear of adverse public judgment of Pasteur for a real or perceived insensitivity to a grave family medical emergency. Such fear would have been in accord with their hagiographic portrayal of Pasteur, and the findings raise questions concerning the extent of their zeal in protecting his “demigod” image. Universal recognition of the true date of Pasteur's announcement of molecular chirality is long overdue. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Significance of HER2 and C‐MYC oncogene amplifications in breast cancer in atomic bomb survivors
Authors: Miura Shiro , Nakashima Masahiro , Ito Masahiro , Kondo Hisayoshi , Meirmanov Serik , Hayashi Tomayoshi , Soda Midori , Matsuo Takeshi , Sekine Ichiro
Published: March 2008

BACKGROUND.

It has been postulated that radiation induces breast cancers in atomic bomb (A‐bomb) survivors. Oncogene amplification is an important mechanism during breast carcinogenesis and also serves as an indicator of genomic instability (GIN). The objective of this study was to clarify the association of oncogene amplification in breast cancer in A‐bomb survivors with radiation exposure.

METHODS.

In total, 593 breast cancers were identified in A‐bomb survivors from 1968 to 1999, and the association between breast cancer incidence and A‐bomb radiation exposure was evaluated. Invasive ductal cancers from 67 survivors and 30 nonsurvivors were analyzed for amplification of the HER2 and C‐MYC genes by fluorescence in situ hybridization, and expression levels of hormone receptors were analyzed by immunostaining.

RESULTS.

The incidence rate increased significantly as exposure distance decreased from the hypocenter (hazard ratio per 1‐km decrement, 1.47; 95% confidence interval [95% CI], 1.30–1.66). The incidence of HER2 and C‐MYC amplification was increased significantly in the order of the control group, the distal group (P = .0238), and the proximal group (P = .0128). Multivariate analyses revealed that distance was a risk factor for the coamplification of C‐MYC and HER2 in breast cancer in survivors (odds ratio per 1‐km increment, 0.17; 95% CI, 0.01–0.63). The histologic grade of breast cancers became significantly higher in the order of the control group, the distal group, and the proximal group and was associated with oncogene amplifications.

CONCLUSIONS.

The current results suggested that A‐bomb radiation may affect the development of oncogene amplification by inducing GIN and may be associated with a higher histologic grade in breast cancer among A‐bomb survivors. Cancer 2008. © 2008 American Cancer Society.
Telomere length and telomerase subunits as diagnostic and prognostic biomarkers in Barrett carcinoma
Authors: Gertler Ralf , Doll Dietrich , Maak Matthias , Feith Marcus , Rosenberg Robert
Published: March 2008

BACKGROUND.

Maintenance of telomeres has been identified as an essential regulator of proliferative capacity and genomic integrity in malignant tumors. The authors evaluated telomere length and telomerase subunits, hTR and hTERT, as prognostic markers in patients with Barrett carcinoma.

METHODS.

Telomere length was measured by Southern blot analysis and hTR expression and hTERT expression by real‐time polymerase chain reaction in both cancer tissue and adjacent noncancerous Barrett mucosa in resection specimens from 46 patients with Barrett carcinoma (International Union Against Cancer [UICC] stages I‐III). The median follow‐up time of the surviving patients was 79 months.

RESULTS.

Cancer tissue expressed more hTERT‐mRNA than noncancerous mucosa (P< .05). Telomere lengths in cancer tissue and in noncancerous mucosa increased with higher pT category (P= .08 andP= .05, respectively). Twenty‐one patients who died of tumor recurrence showed significantly longer telomeres in cancer tissue compared with 25 patients without tumor‐related deaths (P< .05). Telomere length in both cancer tissue and in noncancerous mucosa and the telomere‐length ratio cancer:noncancerous tissue were correlated with overall survival. In multivariate analysis, the telomere‐length ratio proved to be an independent prognostic parameter (P< .02; relative risk of death 3.4; confidence interval, 1.3–8.9). Ten patients with telomere‐length ratios >1.17 had a significantly poorer overall survival compared with 36 patients with telomere‐length ratios ≤1.17 with 5‐year survival rates of 0% and 60%, respectively (P< .02).

CONCLUSIONS.

Telomere length and telomerase subunits were identified as diagnostic and prognostic biomarkers for Barrett carcinoma. Genetic alterations found in adjacent noncancerous mucosa suggested a “field effect” in Barrett carcinoma. Cancer 2008. © 2008 American Cancer Society.
Histologic response of dose‐intense chemotherapy with preoperative hypofractionated radiotherapy for patients with high‐risk soft tissue sarcomas
Authors: Ryan Christopher W. , Montag Anthony G. , Hosenpud Janet R. , Samuels Brian , Hayden James B. , Hung Arthur Y. , Mansoor Atiya , Peabody Terrance D. , Mundt Arno J. , Undevia Samir
Published: March 2008

BACKGROUND.

The authors studied a dose‐intense regimen of epirubicin and ifosfamide with hypofractionated preoperative radiotherapy for high‐risk soft tissue sarcomas. The primary objective was estimation of the rate of ≥95% pathologic necrosis.

METHODS.

Twenty‐five patients with intermediate‐grade or high‐grade, localized soft tissue sarcomas of the extremity or body wall measuring >5 cm were treated with epirubicin at a dose of 30 mg/m2/day on Days 1 to 4 and ifosfamide at a dose of 2.5 g/m2/day on Days 1 to 4 every 21 days for 3 preoperative and 3 postoperative cycles. A total of 28 grays of radiation was administered over 8 fractions during Cycle 2 of preoperative therapy (epirubicin was omitted).

RESULTS.

Sixteen patients (64%) completed all chemotherapy cycles and the average delivered dose intensity relative to intended therapy was 69%. Twenty‐one patients (84%) experienced grade 4 toxicity (using the National Cancer Institute Common Terminology Criteria for Adverse Events [version 2.0]), which was predominantly hematologic. Notable toxicities included neutropenic fever (40%), ifosfamide‐induced encephalopathy (24%), and grade 3/4 anemia (64%). Postoperative wound complications requiring a surgical procedure occurred in 20% of patients. The rate of ≥95% pathologic necrosis was 40% (95% confidence interval [95% CI], 21–59%). Estimates of 2‐year overall and disease‐free survival were 84% (95% CI, 66–100%) and 62% (95% CI, 37–86%), respectively.

CONCLUSIONS.

A high rate of ≥95% pathologic necrosis was noted with this aggressive chemoradiotherapy regimen. The occurrence of significant acute toxicities limited the delivery of the intended dose intensity. Cancer 2008. ©2008 American Cancer Society.
Spatial patterning of cholinergic amacrine cells in the mouse retina
Authors: Whitney Irene E. , Keeley Patrick W. , Raven Mary A. , Reese Benjamin E.
Published: March 2008

Mosaic of cholinergic amacrine cells (green, labeled for choline acetyltransferase) in the ganglion cell layer of the mouse retina. The somal patterning of the mosaic is degraded due to the presence of blood vessels (white, labeled for PNA) and fascicles of optic axon (magenta, labeled for neurofilaments). Also shown are the retinal astrocytes (blue, labeled for glial fibrillary acidic protein). J. Comp. Neurol. 508:1‐12, 2008. © 2008 Wiley‐Liss, Inc.
Fe1−yO Nanoparticles: Organometallic Synthesis and Magnetic Properties
Authors: Glaria Arnaud , Kahn Myrtil L. , Lecante Pierre , Barbara Bernard , Chaudret Bruno
Published: March 2008

Non‐stoichiometric wüstite particles (Fe1−yO) are synthesized using the controlled room‐temperature hydrolysis of the organometallic precursor {Fe[N(SiMe3)2]2}. Particles stabilized by hexadecylamine with a diameter of ∼5 nm are obtained. For such small nanoparticles, a distorted crystallographic structure is evidenced by wide‐angle X‐ray scattering at room temperature and reported for the first time. The study of the magnetic properties indicates that these particles are composed of an antiferromagnetic core surrounded by a ferromagnetic shell. According to the Néel theory, we demonstrate that this shell consists of 1.5 % of Fe3+ ions ferromagnetically coupled with Fe2+ ions.
Expression and activity of P‐glycoprotein (MDR1/ABCB1) in peripheral blood mononuclear cells from patients with anorexia nervosa compared with healthy controls
Authors: Storch Caroline Henrike , Nikendei Christoph , Schild Sandra , Haefeli Walter Emil , Weiss Johanna , Herzog Wolfgang
Published: March 2008

Objective:

Pharmacotherapeutic strategies for treatment of anorexia nervosa (AN) are characterized by limited success. Some drugs used (antipsychotics, selective serotonin reuptake inhibitors) are transported by P‐glycoprotein (P‐gp), a transporter with major impact on pharmacokinetics of substrate drugs. Biochemical alterations seen in AN patients could lead to increased expression and/or activity of P‐gp and therefore to diminished access of drugs to the brain. The aim of our study was to investigate expression and activity levels of P‐gp in peripheral blood mononuclear cells (PBMCs) in AN patients.

Method:

PBMCs of 16 AN patients and 16 controls were isolated. Activity of P‐gp was determined by flow cytometry and expression was quantified by reverse‐transcriptase‐real‐time‐polymerase‐chain‐reaction.

Results:

Neither a significant difference in P‐gp expression (AN: 0.00154 ± 0.00088 [MDR1/β2 mg], control: 0.00244 ± 0.0013 [MDR1/β2 mg], p = .138) nor a difference in P‐gp activity (rhodamine123 ratio AN: 1.79 ± 0.73, control: 2.03 ± 0.42, p = .20) between AN patients and healthy controls could be detected. In contrast to previous studies, expression and activity of P‐gp correlated significantly (p = .0031).

Conclusion:

Failure in pharmacotherapy with P‐gp substrates in AN patients are probably neither caused by different P‐gp expression nor activity levels. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord 2008
F‐Amphiphilic 1,2,3‐Triazoles by Unexpected Intramolecular Cyclisation of Vinyl Azides
Authors: Mayot Estelle , Lemière Pascal , Gérardin‐Charbonnier Christine
Published: March 2008

A series of fluoroalkylated 1,2,3‐triazoles have been synthetised in significant yields through unexpected intramolecular cyclisations of vinyl azides bearing electron‐withdrawing groups. The mechanism proposed in this study implies the participation of a catalytic amount of azide ions in the cyclisations of the vinyl azides to triazoles. The study includes the alkylation of these compounds with various alkylating agents and the evaluation of the surface activities of the ionic derivatives.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis and Reactivity of Silylformylation Products Derived from Alkynes
Authors: Aronica Laura Antonella , Caporusso Anna Maria , Salvadori Piero
Published: March 2008

The silylformylation reaction of unsaturated compounds consists of the rhodium‐catalysed addition of a R3Si and a CHO moiety to a carbon–carbon multiple bond. The silylformylation process is applicable to both terminal and internal alkynes and is tolerant towards several functional groups. Many factors can influence the chemoselectivity of the reaction that generally affords β‐silylalkenals with high yields and regioselectivity. The β‐silylalkenals are polyfunctionalised substrates that can be submitted to several chemical transformations and in particular can undergo fluoride‐promoted (TBAF) aryl migration from an aryldimethylsilyl group to the adjacent carbon atom thus generating 2‐(arylmethyl)aldehydes, important industrial precursors of perfumes. This silylformylation‐aryl migration two‐steps sequence can be applied to functionalised alkyne precursors and chemo‐, regio‐ and stereoselectivity of the products can be modulated according to the nature and the position of the functional group. When a good leaving group is present in the ω position of the aliphatic chain of the alkyne cyclisation products are obtained, while α,β‐unsaturated aldehydes are generated from propargyl tosylamides, acetates and benzoates. α‐Silylmethylene‐β‐lactams, prepared from p‐tosylamides according to silylcarbocyclisation reaction, can be transformed into the corresponding arylmethyl‐β‐lactams by means of TBAF‐induced rearrangement that takes place without involving the lactam ring. A plausible mechanism of the rearrangement reaction is reported that suggests the addition of the fluoride ion to the arylsilicon moiety and the consequent migration of the aryl group to the adjacent carbon atom. Both aryl and heteroaryl substituents can migrate without any loss of configuration further enhancing the high synthetic value of this protocol. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Polarographic Behavior of Human Plasma Thrombin and Changes in Its Anticoagulation Activity Through Various Conformations
Authors: Singh Niyati , Pitre K. S.
Published: March 2008

Thrombin plays a pivotal role in the regulation of blood fluidity and therefore constitutes a primary target in the treatment of various hemostatic disorders. For this differential pulse polarography has been developed in an appropriate supporting electrolyte, which produced well‐defined DPP peaks. The average prothrombin time (PT) in citrated plasma samples was determined, which indicated decrease of average PT with rise of thrombin and albumin concentrations, while PT resulted differently (increase) with heparin, thus confirming their role in anticoagulation activity. The PT of thrombin‐heparin and thrombin‐albumin conformations showed sharp increased and steady decreased respectively. Thus, two opposite actions of thrombin, coagulation (thrombin‐albumin) and anticoagulation (thrombin‐heparin) may prove fruitful in clinical approach for thrombotic disorders.
Electrochemical Behavior and Determination of L‐Tyrosine at Single‐walled Carbon Nanotubes Modified Glassy Carbon Electrode
Authors: Yu Xiaozhi , Mai Zhibin , Xiao Yun , Zou Xiaoyong
Published: March 2008

Based on single‐walled carbon nanotubes (SWCNTs) modified glassy carbon electrode (GCE/SWCNTs), a novel method was presented for the determination of L‐tyrosine. The GCE/SWCNTs exhibited remarkable catalytic and enhanced effects on the oxidation of L‐tyrosine. In 0.10 mol/L citric acid‐sodium citrate buffer solution, the oxidation potential of L‐tyrosine shifted negatively from +1.23 V at bare GCE to +0.76 V at GCE/SWCNTs. Under the optimized experimental conditions, the linear range of the modified electrode to the concentration of L‐tyrosine was 5.0×10−6–2.0×10−5 mol/L (R1=0.9952) and 2.7×10−5–2.6×10−4 mol/L (R2=0.9998) with a detection limit of 9.3×10−8 mol/L. The kinetic parameters such as α (charge transfer coefficient) and D (diffusion coefficient) were evaluated to be 0.66, 9.82×10−5 cm2 s−1, respectively. And the electrochemical mechanism of L‐tyrosine was also discussed.
Heat release rate and computer fire modelling vs real‐scale fire tests in passenger trains
Authors: Capote Jorge A. , Alvear Daniel , Lázaro Mariano , Espina Pablo
Published: March 2008

The materials and products used in passenger trains may not be the first ignited element, but during the fire development, these materials, especially ceiling linings and wall coverings, contribute significantly to the fire growth. The fire safety requirements in passenger trains consist mainly of bench‐scale tests, with particular focus on the sample geometry, position and fire exposition. When this information is extrapolated to real end use conditions limitations appear.

In this paper, a discussion of the use of fire dynamics simulator model and heat release rate experiments in cone calorimeter (bench‐scale test) is presented in order to represent the fire development in a passenger train compartment. For the study, two fire scenarios were selected: (1) the single burning item SBI test (modified) and (2) a passenger train compartment. Initially, the limitations of the assumptions and hypothesis made when producing the model were analyzed and the research team carried out a sensitivity study of the model results considering different grid sizes.

In order to validate the model, both bench‐ and full‐scale fire tests were considered based on the results provided by the European research program FIRESTARR. The limitations and uncertainties in the results demonstrate the importance of two basic factors: the incident heat flux in the cone calorimeter tests and the prescribed ignition temperature. Copyright © 2008 John Wiley & Sons, Ltd.
Human survivability in motor vehicle fires
Authors: Digges K. H. , Gann R. G. , Grayson S. J. , Hirschler M. M. , Lyon R. E. , Purser D. A. , Quintiere J. G. , Stephenson R. R. , Tewarson A.
Published: March 2008

Automobile fires are consistently among the largest causes of fire death in the United States (about 500 annually) and the U.S. motor vehicle industry and others have spent a significant amount of money in recent years studying this problem. The authors of this review have analyzed the auto industry reports, the scientific literature, and statistical data, and conclude that measures should be taken to improve survivability in automobile fires. The U.S. Federal Motor Vehicle Safety Standard 302 (FMVSS 302) was introduced almost 40 years ago to measure the flammability of interior materials, but improvements in the crashworthiness of automobiles and their fuel tanks and the increased use of combustible materials have changed the motor vehicle fire scenario significantly. In particular, the primary threat has changed from ignition of a small quantity of combustible interior materials by a lit cigarette, in 1960, to ignition of a large quantity of combustible interior and exterior materials by an impact‐induced fire, at present. The authors therefore suggest that FMVSS 302 is no longer relevant to automobile fire safety and recommend improved standards based on objective criteria for fire safety performance (fireworthiness) at the system/vehicle level as is routinely done for crashworthiness. Copyright © 2008 John Wiley & Sons, Ltd.
Flame retardation and thermal degradation of flame‐retarded polypropylene composites containing melamine phosphate and pentaerythritol phosphate
Authors: Zhou Shun , Wang Zhengzhou , Gui Zhou , Hu Yuan
Published: March 2008

The flame retardation of polypropylene (PP) composites containing melamine phosphate (MP) and pentaerythritol phosphate (PEPA) was characterized by limiting oxygen index (LOI) and UL 94. The morphology of the char obtained from the combustion of the composites was studied by scanning electron microscopy (SEM). The thermal degradation of the composites was investigated using thermogravimetric (TG) analysis and real‐time Fourier transform infrared (RTFTIR) spectroscopy. It has been found that the PP composites containing only MP do not show good flame retardancy even at 40% additive level. Compared with the PP/MP binary composites, all the LOI values of the PP/MP/PEPA ternary composites at the same additive loading increase, and UL 94 ratings of the ternary composites at suitable MP/PEPA ratios are raised to V‐0 from no rating (PP/MP). The TG and RTFTIR studies indicate that the interaction occurs among MP, PEPA and PP. Copyright © 2008 John Wiley & Sons, Ltd.
Spectral/hp penalty least‐squares finite element formulation for unsteady incompressible flows
Authors: Prabhakar V. , Reddy J. N.
Published: March 2008

In this paper, we present spectral/hp penalty least‐squares finite element formulation for the numerical solution of unsteady incompressible Navier–Stokes equations. Pressure is eliminated from Navier–Stokes equations using penalty method, and finite element model is developed in terms of velocity, vorticity and dilatation. High‐order element expansions are used to construct discrete form. Unlike other penalty finite element formulations, equal‐order Gauss integration is used for both viscous and penalty terms of the coefficient matrix. For time integration, space–time decoupled schemes are implemented. Second‐order accuracy of the time integration scheme is established using the method of manufactured solution. Numerical results are presented for impulsively started lid‐driven cavity flow at Reynolds number of 5000 and transient flow over a backward‐facing step. The effect of penalty parameter on the accuracy is investigated thoroughly in this paper and results are presented for a range of penalty parameter. Present formulation produces very accurate results for even very low penalty parameters (10–50). Copyright © 2008 John Wiley & Sons, Ltd.
A further work on multi‐phase two‐fluid approach for compressible multi‐phase flows
Authors: Niu Yang‐Yao , Lin Yu‐Chin , Chang Chih‐Hao
Published: March 2008

This paper is to continue our previous work Niu (Int. J. Numer. Meth. Fluids 2001; 36:351–371) on solving a two‐fluid model for compressible liquid–gas flows using the AUSMDV scheme. We first propose a pressure–velocity‐based diffusion term originally derived from AUSMDV scheme Wada and Liou (SIAM J. Sci. Comput. 1997; 18(3):633—657) to enhance its robustness. The scheme can be applied to gas and liquid fluids universally. We then employ the stratified flow model Chang and Liou (J. Comput. Physics 2007; 225:240–873) for spatial discretization. By defining the fluids in different regions and introducing inter‐phasic force on cell boundary, the stratified flow model allows the conservation laws to be applied on each phase, and therefore, it is able to capture fluid discontinuities, such as the fluid interfaces and shock waves, accurately. Several benchmark tests are studied, including the Ransom's Faucet problem, 1D air–water shock tube problems, 2D shock‐water column and 2D shock‐bubble interaction problems. The results indicate that the incorporation of the new dissipation into AUSM+‐up scheme and the stratified flow model is simple, accurate and robust enough for the compressible multi‐phase flows. Copyright © 2008 John Wiley & Sons, Ltd.
A new volume of fluid method in three dimensions—Part II: Piecewise‐planar interface reconstruction with cubic‐Bézier fit
Authors: López J. , Zanzi C. , Gómez P. , Faura F. , Hernández J.
Published: March 2008

A new interface reconstruction method in 3D is presented. The method involves a conservative level‐contour reconstruction coupled to a cubic‐Bézier interpolation. The use of the proposed piecewise linear interface calculation (PLIC) reconstruction scheme coupled to a multidimensional time integration provides solutions of second‐order spatial and temporal accuracy. The accuracy and efficiency of the proposed reconstruction algorithm are demonstrated through several tests, whose results are compared with those obtained with other recently proposed methods. An overall improvement in accuracy with respect to other recent methods has been achieved, along with a substantial reduction in the central processing unit time required. Copyright © 2008 John Wiley & Sons, Ltd.