bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Walking-Safety Scale for Older Adults, Part II: Interrater and Test–Retest Agreement of the GEM Scale
Authors: Dubé François , Rousseau Jacqueline , Kaegi Christine , Boudreault Renée , Nadeau Sylvie
Published: October 2008

Purpose: The GEM scale is an objective assessment tool, specifically developed for older adults, to evaluate walking safety using standardized tasks. The purpose of this study was to estimate the interrater and test–retest agreement of the GEM scale.

Method: Participants (n = 41; ≥ 65 years) were recruited from geriatric units and assessed independently and simultaneously by three raters on two occasions using the GEM scale. Kappa coefficients and percentage agreement were calculated for each item of the scale.

Results: A majority of walking items (n = 22) showed fair to substantial interrater agreement (κ ≥ 0.25) and substantial to almost perfect test–retest agreement (κ ≥ 0.60). Mean percentage agreement was high for both interrater and test–retest agreement (79% ± 15% and 83% ± 16% respectively). Moreover, detailed analyses demonstrated that the relatively low agreement of some items resulted from changes in the performance of some participants and the low variability of scores. Although some walking items showed less agreement, the final decision regarding the participants’ ability to walk safely resulted in moderate to substantial interrater and test–retest agreement.

Conclusion: The GEM scale is a new assessment tool that can now be used with estimated interrater and test–retest properties to allow therapists to objectively evaluate walking safety among the elderly.
Response to Endothelin-1 in Arteries from Human Colorectal Tumours: Role of Endothelin Receptors
Authors: Ferrero Eduardo , Labalde Maria , Fernández Nuria , Monge Luis , Salcedo Adely , Narvaez-Sanchez Raul , Hidalgo Manuel , Dieguez Godofredo , García-Villalon Angel Luis
Published: October 2008

To examine the reaction of tumour arteries to endothelin-1, we obtained arteries supplying blood flow to colorectal tumours from patients, as well as mesenteric arteries supplying the normal colon tissue from the same patients and mesenteric arteries from patients without a colorectal tumour pathology. The contraction in response to endothelin-1 and the relaxation produced by bradykinin was recorded in each of these arteries. Accordingly, the sensitivity to endothelin-1 but not the maximal response, was higher in the arteries supplying colorectal tumours than in mesenteric arteries supplying normal colon or in mesenteric arteries from patients with no tumour pathology. The contraction produced by endothelin-1 was not modified by exposure to L-NAME or meclofenamate in arteries supplying both the tumour and the normal colon. The endothelin ETA andETB receptors were expressed similarly in arteries supplying the tumour or normal colon. However, the antagonist of the endothelin ETB receptors BQ788 (10−6 M) decreased the contractions in the arteries supplying the tumour but not in those supplying the normal colon. By contrast, the antagonist of endothelin ETA receptors BQ123 (10−6 M) reduced the contraction equally in both these types of arteries. Likewise, in arteries precontracted with U46619, the relaxation in response to bradykinin was similar in all three types of arteries. Together, these results suggest that the arteries supplying human colorectal tumours are more sensitive to endothelin-1, which could be due to the enhanced activity of endothelin ETB receptors in the absence of any change in the modulatory effect of nitric oxide or prostanoids in the arterial response to this peptide.
Efflux of Iron from the Cerebrospinal Fluid to the Blood at the Blood-CSF Barrier: Effect of Manganese Exposure
Authors: Wang Xueqian , Li G. Jane , Zheng Wei
Published: October 2008

The blood-cerebrospinal fluid (CSF) barrier (BCB) resides within the choroid plexus, with the apical side facing the CSF and the basolateral side towards the blood. Previous studies demonstrate that manganese (Mn) exposure in rats disrupts iron (Fe) homeostasis in the blood and CSF. The present study used a primary culture of rat choroidal epithelial cells grown in the two-chamber Transwell system to investigate the transepithelial transport of Fe across the BCB. Free, unbound Fe as [59Fe] was added to the donor chamber and the radioactivity in the acceptor chamber was quantified to determine the direction of Fe fluxes. Under the normal condition, the [59Fe] efflux (from the CSF to the blood) was 128% higher than that of the influx (P < 0.01). Mn exposure significantly increased the efflux rate of [59Fe] (P < 0.01) and the effect was inhibited when the cells were pre-incubated with the antibody against divalent metal transport 1 (DMT1). Moreover, when the siRNA knocked down the cellular DMT1 expression, the elevated Fe uptake caused by Mn exposure in the choroidal epithelial Z310 cells was completely abolished, indicating that Mn may facilitate Fe efflux via a DMT1-mediated transport mechanism. In vivo subchronic exposure to Mn in rats reduced Fe clearance from the CSF, as demonstrated by the ventriculo-cisternal brain perfusion, along with up-regulated mRNAs encoding DMT1 and transferrin receptor (TfR) in the same animals. Taken together, these data suggest that free Fe appears to be favorably transported from the CSF toward the blood by DMT1 and this process can be facilitated by Mn exposure. Enhanced TfR-mediated influx of Fe from the blood and ferroportin-mediated expelling Fe toward the CSF may compromise DMT1-mediated efflux, leading to an increased Fe concentration in the CSF as seen in Mn-exposed animals.
Association of Genetic Polymorphisms in Vitamin D Receptor Gene and Susceptibility to Sporadic Prostate Cancer
Authors: Onen Ilke Hacer , Ekmekci Abdullah , Eroglu Muzaffer , Konac Ece , Yesil Suleyman , Biri Hasan
Published: October 2008

Genetic and environmental factors are involved in prostate cancer (PCa) etiology. Single nucleotide polymorphisms (SNPs) may contribute to the PCa pathogenesis. The goal of this study is to determine the role of vitamin D receptor ( VDR) gene polymorphisms and haplotypes in the development and progression of sporadic PCa. One hundred and thirty-three PCa patients and 157 age-matched healthy controls were genotyped for the Apa I (rs7975232) , Bsm I (rs1544410) and Taq I (rs731236) polymorphisms in VDR gene by using polymerase chain reaction-restriction fragment length polymorphism. An association was observed between the Apa I polymorphism and PCa predisposition ( P = 0.03). When compared with AA genotype, there was a highly notable difference in the frequencies of the Aa ( P = 0.02), aa ( P = 0.026) and Apa I ‘‘a’’ allele carriers (Aa + aa) ( P = 0.009) genotypes. Furthermore, we found a statistical difference in the allele frequencies of the Apa I polymorphism between the sporadic PCa patients and control subjects ( P = 0.013). The genotype distribution for the Bsm I and Taq I polymorphisms were similar between cases and controls (P > 0.05). No clinically significant relationship was found between the three-locus haplotypes and development of sporadic PCa. The genotype frequencies for the three polymorphisms of the VDR gene within subgroups of PCa (defined by tumor stage, Gleason score, PSA levels) were also analyzed, but no statistically noteworthy difference was observed (P > 0.05). As far as we know, this is the first study which investigates the relationship between VDR genotypes and sporadic PCa in the Turkish population. Our findings suggest that the VDR ApaI (rs7975232) polymorphism may play a role in the development of sporadic PCa.
Timing of Egf Treatment Differentially Affects Tgf-β2 Induced Cranial Suture Closure
Authors: Rawlins Joseph T. , Fernandez Claudia R. , Cozby Melina E. , Opperman Lynne A.
Published: October 2008

Premature suture obliteration results in an inability of cranial and facial bones to grow, with craniofacial dysmorphology requiring surgical correction as a consequence. Understanding signaling pathways associated with suture morphogenesis might enable non-invasive treatment of patients with fused sutures. Tgf-β 2 induces premature suture fusion associated with increased cell proliferation both in vitro and in vivo. Tgf-β 2 and Egf signal transduction pathways use some signaling proteins in common to regulate proliferation and differentiation, leading to speculation that these two pathways converge to regulate normal suture development. It was therefore hypothesized that Egf could induce suture fusion, and that Tgf-β 2-induced suture closure occurred via an Egf-dependent pathway. A well-established fetal calvarial organ culture system was used to expose developing E19.5 fetal rat coronal sutures to Egf, Tgf-β 2 and SC-120, a blocker of Egf receptor activity. Co-culture experiments examined the effect of Egf on Tgf-β 2-induced suture closure when Egf was given either prior to or after Tgf-β 2 treatment. Histomorphometric measurement of suture width was done on sagittal sections through coronal sutures harvested after 5 days in culture. Western blotting using phospho-antibodies against Egf receptors was used to confirm Egf receptor activity. Suture width increased with increasing concentrations of Egf, demonstrating that Egf-induced cell activity alone was not sufficient to cause premature suture obliteration. Egf administered prior to Tgf-β 2 treatment rescued sutures from Tgf-β 2-induced suture obliteration, demonstrating that pre-exposure of cells to this powerful mitogen prevented their response to signals induced by Tgf-β 2. However, Egf added after Tgf-β 2 treatment had no effect on Tgf-β 2-induced suture closure. Blocking Egf activity after Tgf-β 2 treatment rescued sutures from Tgf-β 2-induced obliteration, indicating that Tgf-β 2 required Egf activity to induce suture obliteration. Appropriate timing of signal generation by Egf and Tgf-β 2 is critical for normal suture development and maintenance of suture patency.
Osteopontin Prevents Curcumin-Induced Apoptosis and Promotes Survival Through Akt Activation via αvβ3 Integrins in Human Gastric Cancer Cells
Authors: Song Gang , Ming Yanlin , Mao Yubin , Bao Shideng , Ouyang Gaoliang
Published: October 2008

Osteopontin (OPN) is a secreted, integrin-binding matrix phosphorylated glycoprotein that is overexpressed in many advanced cancers. However, the functional mechanisms by which OPN contributes to gastric cancer development are poorly understood. Here, we report that curcumin inhibited the growth of SGC7901 cell and induced apoptosis in a concentration- and time-dependent manner, while the acquired expression of OPN in SGC7901 cells dramatically promoted cell survival under serum depletion and prevented curcumin-induced apoptosis. Furthermore, PI3-K inhibitor LY294002 attenuated OPN-mediated Akt activation. Moreover, inhibiting the binding of OPN to αvβ3 integrins reduced activation of Akt. Taken together, these results demonstrate that the pro-survival and anti-apoptosis activities of OPN in gastric cancer cells are mediated in part through PI3-K/Akt pathway via αvβ3 integrins.
Pharmaco-Proteomic Study of Hydroxyurea-Induced Modifications in the Sickle Red Blood Cell Membrane Proteome
Authors: Ghatpande Swati S. , Choudhary Pankaj K. , Quinn Charles T. , Goodman Steven R.
Published: October 2008

Hydroxyurea (HU) is an effective oral drug for the management of homozygous sickle cell anemia (SS) in part because it increases fetal hemoglobin (HbF) levels within sickle red blood cells (RBCs) and thus reduces sickling. However, results from the Multicenter Study of HU suggested that clinical symptoms often improved before a significant increase in HbF levels occurred. This indicated that HU may be acting through the modification of additional cellular mechanisms that are yet to be identified. Hence, in this study, we focused on the analysis of the sickle RBC membrane proteome +/− HU treatment. 2D-DIGE (Two Dimensional Difference In-Gel Electrophoresis) technology and tandem mass spectrometry has been used to determine quantitative differences between sickle cell membrane proteins in the presence and absence of a clinically relevant concentration of HU. In vitro protein profiling of 13 sickle RBC membrane samples +/− 50 μM HU identified 10 statistically significant protein spots. Of these, the most remarkable class of proteins to show a statistically significant increase was the anti-oxidant enzymes—catalase, thioredoxin peroxidase and biliver-din reductase and the chaperonin containing TCP1 complex assisting in the folding of RBC cytoskeletal proteins. Interestingly, catalase immunoblots showed an increase in the acidic forms of the enzyme within sickle RBC membranes on incubation with 50 μM HU. We further identified this modification in catalase to be phosphorylation and demonstrated that HU exposed SS RBC membranes showed a 2-fold increase in tyrosine phosphorylation of catalase as compared to counterparts not exposed to HU. These results present an attractive model for HU-induced post-translational modification and potential activation of catalase in mature sickle RBCs. These findings also identify protein targets of HU other than fetal hemoglobin and enhance the understanding of the drug mechanism.
Molecular characterization of a patient with 3p deletion syndrome and a review of the literature
Authors: Fernandez Thomas V. , García‐González I.J. , Mason Christopher E. , Hernández‐Zaragoza G. , Ledezma‐Rodríguez V.C. , Anguiano‐Alvarez V.M. , E'Vega R. , Gutiérrez‐Angulo M. , Maya M.L. , García‐Bejarano H.E. , González‐Cruz M. , Barrios S. , Atorga R. , López‐Cardona M.G. , Armendariz‐Borunda J. , State Matthew W. , Dávalos Nory O.
Published: October 2008

3p deletion syndrome is a rare disorder involving developmental delay, dysmorphic physical features, and growth retardation. Molecular mapping of several cases in the literature have identified a critical region on chromosome 3p26. We present a child patient with characteristic features of 3p deletion syndrome and a de novo unbalanced translocation involving chromosomes 3 and 13. Fine mapping of this rearrangement using fluorescence in situ hybridization (FISH) and array‐based comparative genomic hybridization (aCGH) revealed an unbalanced abnormality including a 4.5 Mb terminal deletion of chromosome 3p, telomeric to ITPR1 on 3p26.2, which was not previously identified with routine cytogenetic analysis. In addition, these investigations confirmed and refined the boundaries of a 26.5 Mb deletion of chromosome 13. This study confirms the minimal candidate region for 3p deletion syndrome, provides further evidence implicating haploinsufficiency of CNTN4 in the disorder, and demonstrates the utility of high‐resolution investigations of rare chromosomal rearrangements. © 2008 Wiley‐Liss, Inc.
Habituation and desensitization as methods for reducing fearful behavior in singly housed rhesus macaques
Authors: Clay Andrea W. , Bloomsmith Mollie A. , Marr M. Jackson , Maple Terry L.
Published: October 2008

Operant conditioning using positive reinforcement techniques has been used extensively in the management of nonhuman primates in both zoological and laboratory settings. This research project was intended to test the usefulness of counter‐conditioning techniques in reducing the fear‐responses of singly housed male rhesus macaques living in the laboratory environment. A total of 18 male rhesus macaques (Macaca mulatta) were selected for this project and randomly assigned to one of three groups: a desensitization training group, a husbandry training group, or a control group. Behavioral data were collected before and after a 6 weeks training and/or habituation period during which the first two groups received a total of 125 min of positive reinforcement training (and also were assumed to undergo habituation to the environment) and the control group experienced only simple habituation to the environment. Based on a Wilcoxon Matched‐Pairs Sign Test, we found that a significant proportion of animals exposed to desensitization training showed a reduction in the rate at which they engaged in cringing toward humans (exact significance=0.016, one‐tailed, N–ties=6), cringing in general (exact significance=0.016, one‐tailed, N–ties=6), and in stress‐related behaviors (exact significance=0.016, one‐tailed, N–ties=6). This was not the case for animals exposed to basic husbandry training or animals in the control group. A significant proportion of desensitization‐exposed animals also showed a reduction in the duration of time spent cringing toward humans (exact significance=0.016, one‐tailed, N–ties=6), but not in cringing behaviors in general or in stress‐related behaviors. There were not a significant proportion of animals in either the husbandry training group or the control group that showed a decrease in duration of these behaviors. Results of this study could enhance both laboratory animal welfare and laboratory animal research, and could be a first step in developing techniques for reducing fearful behavior in rhesus monkeys in the laboratory environment. Am. J. Primatol. 71:30–39, 2009. © 2008 Wiley‐Liss, Inc.
Behavior patterns of Southern Bearded Sakis (Chiropotes satanas) in the fragmented landscape of Eastern Brazilian Amazonia
Authors: Silva Suleima S. B. , Ferrari Stephen F.
Published: October 2008

The endangered but poorly studied southern bearded saki,Chiropotes satanas,faces extremes of habitat fragmentation throughout its geographic range in eastern Amazonia. This article focuses on the behavior of the members of two groups—a large one (30–34 members) in continuous forest (home range=69 ha) and a much smaller one (7 members) on a 17‐ha man‐made island—at the Tucuruí Reservoir on the Tocantins River. Quantitative behavioral data were collected through scan and all‐events sampling. Both groups were characterized by the fission–fusion pattern of social organization typical of the genus and relatively high rates of traveling and feeding, also characteristic of the genus. However, the island group spent significantly more time resting and significantly less traveling than the mainland group, presumably as a function of its much smaller home range. Despite resting more, island group members engaged in significantly less social interaction, possibly because of the much smaller size of this group (which also affected visibility), or other factors, such as nutritional stress. Affiliative associations of males were a mainstay of social behavior in both groups and interspecific associations with capuchins (Cebus apella) and squirrel monkeys (Saimiri sciureus) were relatively common, especially in the mainland group. Overall, the island group presented a relatively reduced behavioral repertoire, apparently reflecting factors such as group size and the size and quality of its home range. Am. J. Primatol. 71:1–7, 2009. © 2008 Wiley‐Liss, Inc.
Enantiokomplementäre Enzyme: Klassifizierung, molekulare Grundlage der Enantiopräferenz und Prognosen für spiegelbildliche Biotransformationen
Authors: Mugford Paul F. , Wagner Ulrike G. , Jiang Yun , Faber Kurt , Kazlauskas Romas J.
Published: October 2008

Eine häufig zitierte Schwäche der Biokatalyse ist das Fehlen spiegelbildlicher Enzyme, um in asymmetrischen Synthesen jedes der beiden Enantiomere herstellen zu können. Als Lösung für dieses Problem hat die Natur enantiokomplementäre Enzyme entwickelt – also Enzympaare, die dieselben Reaktionen katalysieren, aber entgegengesetzte Enantiomere bevorzugen. Diese Proteine sind nicht spiegelbildlich, aber sie enthalten funktionell spiegelbildliche aktive Zentren. Um spiegelbildliche aktive Zentren zu erhalten, kann die Natur die Position der Bindungsstellen und/oder der wichtigsten katalytischen Gruppen verändern. Dieser Kurzaufsatz stellt Röntgenkristallstrukturen von enantiokomplementären Enzymen vor und klassifiziert diese nach der Anordnung der spiegelbildlichen aktiven Zentren in vier Gruppen.
Synthesis, characterization and applications of coordination polymers of Ln(III)
Authors: Patel M. M. , Kapadia M. A. , Joshi J. D.
Published: October 2008

The resin was synthesized by condensation of 2‐hydroxy‐4‐ethoxybenzophenone with 1,4‐butane diol in presence of polyphosphoric acid as a catalyst at 155 °C for 10 h. The synthesized resin was used to get polychelates of 4f‐block elements. The resin and its polychelates were characterized on the basis of elemental analyses, electronic spectra, magnetic susceptibilities, FTIR, NMR and thermogravimetric analyses. Morphological study of resin and polychelates were carried out by scanning electron microscope. The number average molecular weight (M̄n) was determined using a vapor pressure osmometry method. The catalytic activity of selected polychelates was examined for organic synthesis. It is observed from the study that polychelates give excellent results. They were found to be efficient and effective catalysts and antimicrobial agents. Copyright © 2008 John Wiley & Sons, Ltd.
Accessibility of acrylic fiber to basic dye
Authors: Wang Huei‐Hsiung
Published: October 2008

The accessibility of the fiber to dye is considered to be related to the fraction of the polymer segment which is mobile. This is studied by dyeing the acrylic fiber at temperatures within a 40°C range while treating the samples with different carriers. The relation of the equilibrium dye uptake (dyeability) of the acrylic fiber to the structural parameter, ∫ (tanδ)cdT, with the presence or absence of carrier in solution is linear, confirming the validity of the hypotheses, where (tan δ)c is the loss tangent correlated at a temperature of 20°C. Moreover, The effect of carrier to swell the amorphous region of the acrylic fiber was less effective as temperature beyond Tg (mechanical). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The effect of low‐filler volume fraction on the elastic modulus and thermal expansion coefficient of particulate composites simulated by a multiphase model
Authors: Sideridis E. , Kytopoulos V. N. , Papadopoulos G. A. , Bourkas G. D.
Published: October 2008

The aim of this investigation is to determine the effect of low‐filler volume fraction on the elastic modulus and the thermal expansion coefficient of particulate composites. In the theoretical part, theoretical model valid for low‐filler volume fractions is used to evaluate these two magnitudes. In the experimental part, low‐percentage filler contents of 3, 5, 7, and 10% are used. The density for these epoxy resin‐iron particle composites is also determined. At the same time, an attempt to explain some of the disagreements observed between theoretical values and experimental data on a qualitative basis is also made. This attempt is in part assisted by scanning electron microscopy (SEM) observations concerning structural inhomogeneities and fractographical data. The comparison of the theoretical values derived from the present model with experimental results and with theoretical values derived from other workers appears satisfactory in many cases, but in some others the discrepancies among them are considerable. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of starch nanocrystal‐graft‐polycaprolactone on mechanical properties of waterborne polyurethane‐based nanocomposites
Authors: Chang Peter R. , Ai Fujin , Chen Yun , Dufresne Alain , Huang Jin
Published: October 2008

Based on a “graft from” strategy, the surface of starch nanocrystals (StN) were functionalized by grafting with polycaprolactone (PCL) chains via microwave assisted ring‐opening polymerization (ROP). The modified natural nanoparticles were then compounded into a PCL‐based waterborne polyurethane as matrix. The structural and mechanical properties of the WPU/StN‐g‐PCL nanocomposites were characterized by XRD, FTIR, SEM, DSC, DMA, and tensile testing. It was interesting to note that a loading‐level of 5 wt % StN‐g‐PCL resulted in a simultaneous enhancement of tensile strength and elongation at break, both of which were higher than those of neat WPU. This enhancement was attributed to the uniform dispersion of StN‐g‐PCL because of its nano‐scale size, the increased entanglements mediated with grafted PCL chains, and the reinforcing function of rigid StN. Increasing the StN‐g‐PCL content however caused the StN‐g‐PCL to self‐aggregate as crystalline domains, which impeded improvement in tensile strength and elongation at break, but significantly enhanced Young's modulus. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Solvent‐ and thermal‐induced crystallization of poly‐L‐lactic acid in supercritical CO2 medium
Authors: López‐Periago Ana , García‐González Carlos A. , Domingo Concepción
Published: October 2008

The effect of different annealing treatments with supercritical carbon dioxide (SCCO2) on the structural and mechanical properties of semicrystalline poly‐L‐lactic acid (L‐PLA) was investigated. 2000, 27,000, 100,000, and 350,000 g mol−1 molecular weight L‐PLA polymers were used in the study. The solid‐state processing of L‐PLA at temperatures lower than the effective melting point led to solvent‐ and thermal‐induced crystallization. Solvent‐induced and isothermal crystallization mechanisms could be considered similar regarding the increase of polymer chain mobility and mass‐transfer in the amorphous region; however, quite different microstructures were obtained. SCCO2 solvent‐induced crystallization led to polymers with high crystallinity and melting point. On the contrary, SCCO2 thermal‐induced crystallization led to polymers with high crystallinity and low melting point. For these polymers, the hardness increased and the elasticity decreased. Finally, the effect of dissolving SCCO2 in the molten polymer (cooling from the melt) was analyzed. Cooling from the melt led to polymers with high crystallinity, low melting point, low hardness, and low elasticity. Distinctive crystal growth and nucleation episodes were identified. This work also addressed the interaction of SCCO2‐drug (triflusal) solution with semicrystalline L‐PLA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Phosphorescence Color Tuning by Ligand, and Substituent Effects of Multifunctional Iridium(III) Cyclometalates with 9‐Arylcarbazole Moieties
Authors: Ho Cheuk‐Lam , Wang Qi , Lam Ching‐Shan , Wong Wai‐Yeung , Ma Dongge , Wang Lixiang , Gao Zhi‐Qiang , Chen Chin‐Hsin , Cheah Kok‐Wai , Lin Zhenyang
Published: October 2008

The synthesis, isomeric studies, and photophysical characterization of a series of multifunctional cyclometalated iridium(III) complexes containing a fluoro‐ or methyl‐substituted 2‐[3‐(N‐phenylcarbazolyl)]pyridine molecular framework are presented. All of the complexes are thermally stable solids and highly efficient electrophosphors. The optical, electrochemical, photo‐, and electrophosphorescence traits of these iridium phosphors have been studied in terms of the electronic nature and coordinating site of the aryl or pyridyl ring substituents. The correlation between the functional properties of these phosphors and the results of density functional theory calculations was made. Arising from the propensity of the electron‐rich carbazolyl group to facilitate hole injection/transport, the presence of such a moiety can increase the highest‐occupied molecular orbital levels and improve the charge balance in the resulting complexes relative to the parent phosphor with 2‐phenylpyridine ligands. Remarkably, the excited‐state properties can be manipulated through ligand and substituent effects that allow the tuning of phosphorescence energies from bluish green to deep red. Electrophosphorescent organic light‐emitting diodes (OLEDs) with outstanding device performance can be fabricated based on these materials, which show a maximum current efficiency of approximately 43.4 cd A−1, corresponding to an external quantum efficiency of approximately 12.9 % ph/el (photons per electron) and a power efficiency of approximately 33.4 Lm W−1 for the best device. The present work provides a new avenue for the rational design of multifunctional iridium–carbazolyl electrophosphors, by synthetically tailoring the carbazolyl pyridine ring that can reveal a superior device performance coupled with good color‐tuning versatility, suitable for multicolor‐display technology.
A DFT Study on the Reaction Pathways for CarbonCarbon Bond‐Forming Reactions between Propargylic Alcohols and Alkenes or Ketones Catalyzed by Thiolate‐Bridged Diruthenium Complexes
Authors: Sakata Ken , Miyake Yoshihiro , Nishibayashi Yoshiaki
Published: October 2008

The reaction pathways of two types of the carboncarbon bond‐forming reactions catalyzed by thiolate‐bridged diruthenium complexes have been investigated by density‐functional‐theory calculations. It is clarified that both carboncarbon bond‐forming reactions proceed through a ruthenium–allenylidene complex as a common reactive intermediate. The attack of π electrons on propene or the vinyl alcohol on the ruthenium–allenylidene complex is the first step of the reaction pathways. The reaction pathways are different after the attack of nucleophiles on the ruthenium–alkynyl complex. In the reaction with propene, the carboncarbon bond‐forming reaction proceeds through a stepwise process, whereas in the reaction with vinyl alcohol, it proceeds through a concerted process. The interactions between the ruthenium–allenylidene complex and propene or vinyl alcohol have been investigated by applying a simple way of looking at orbital interactions.
Tetrahedral Oligothiophenes; Synthesis, X‐ray Analysis, and Optoelectronic Properties of Highly Symmetrical, 3D‐Branched Oligothiophenes
Authors: Matsumoto Kouzou , Tanaka Toru , Kugo Sota , Inagaki Takuya , Hirao Yoshikazu , Kurata Hiroyuki , Kawase Takeshi , Kubo Takashi
Published: October 2008

Tetrakis(bithienyl)methane and tetrakis(terthienyl)methane have been synthesized from tetrakis(2‐thienyl)methane by use of Suzuki–Miyaura coupling as a key reaction. Their trimethylsilyl (TMS) derivatives are also synthesized. X‐ray analysis reveals that each oligothiophene moiety tends to adopt anti‐conformations and show relatively small torsion angles between the adjacent thiophene rings. While the longest absorption maxima of these tetrakis(oligothienyl)methanes exhibit only a slight bathochromic shift compared to the corresponding linear oligothiophene derivative, tetrakis(bithienyl)methane and its TMS derivative exhibit an appreciable red‐shift in their fluorescence spectra. The intramolecular interaction between thienyl groups of tetrakis(2‐thienyl)methane is supported by DFT calculation.
3‐ Instead of 4‐Helix Formation in a De Novo Designed Protein in Solution Revealed by Small‐Angle X‐ray Scattering
Authors: Høiberg‐Nielsen Rasmus , Tofteng Shelton A. Pernille , Sørensen Kasper K. , Roessle Manfred , Svergun Dimitri I. , Thulstrup Peter W. , Jensen Knud J. , Arleth Lise
Published: October 2008

De novo design and chemical synthesis of proteins and their mimics are central approaches for understanding protein folding and accessing proteins with novel functions. We have previously described carbohydrates as templates for the assembly of artificial proteins, so‐called carboproteins. Here, we describe the preparation and structural studies of three α‐helical bundle carboproteins, which were assembled from three different carbohydrate templates and one amphiphilic hexadecapeptide sequence. This heptad repeat peptide sequence has been reported to lead to 4‐α‐helix formation. The low resolution solution structures of the three carboproteins were analyzed by means of small‐angle X‐ray scattering (SAXS) and synchrotron radiation circular dichroism (SRCD). The ab initio SAXS data analysis revealed that all three carboproteins adopted an unexpected 3+1‐helix folding topology in solution, while the free peptide formed a 3‐helix bundle. This finding is consistent with the calculated α‐helicities based on the SRCD data, which are 72 and 68 % for two of the carboproteins. The choice of template did not affect the overall folding topology (that is for the 3+1 helix bundle) the template did have a noticeable impact on the solution structure. This was particularly evident when comparing 4‐helix carboprotein monomers with the 2×2‐helix carboprotein dimer as the latter adopted a more compact conformation. Furthermore, the clear conformational differences observed between the two 4‐helix (3+1) carboproteins based on D‐altropyranoside and D‐galactopyranoside support the notion that folding is affected by the template, and subtle variations in template distance‐geometry design may be exploited to control the solution fold. In addition, the SRCD data show that template assembly significantly increases thermostability.
Structural and Immunochemical Analysis of the Lipopolysaccharide from Acinetobacter lwoffii F78 Located Outside Chlamydiaceae with a Chlamydia‐Specific Lipopolysaccharide Epitope
Authors: Hanuszkiewicz Anna , Hübner Göran , Vinogradov Evgeny , Lindner Buko , Brade Lore , Brade Helmut , Debarry Jennifer , Heine Holger , Holst Otto
Published: October 2008

Chemical analyses, NMR spectroscopy, and mass spectrometry were used to elucidate the structure of the rough lipopolysaccharide (LPS) isolated from Acinetobacter lwoffii F78. As a prominent feature, the core region of this LPS contained the disaccharide α‐Kdo‐(2→8)‐α‐Kdo (Kdo=3‐deoxy‐d‐D‐manno‐oct‐2‐ulopyranosonic acid), which so far has been identified only in chlamydial LPS. In serological investigations, the anti‐chlamydial LPS monoclonal antibody S25–2, which is specific for the epitope α‐Kdo‐(2→8)‐α‐Kdo, reacted with A. lwoffii F78 LPS. Thus, an LPS was identified outside Chlamydiaceae that contains a Chlamydia‐specific LPS epitope in its core region.
Natural Gum Reduced/Stabilized Gold Nanoparticles for Drug Delivery Formulations
Authors: Dhar Sheetal , Reddy E. Maheswara , Shiras Anjali , Pokharkar Varsha , Prasad B. L. V.
Published: October 2008

“Gellan Gum”, widely used in food and confectionary industry as a thickening and gelling agent, has been employed as a reducing and stabilizing agent for the synthesis of gold nanoparticles. These nanoparticles display greater stability to electrolyte addition and pH changes relative to the traditional citrate and borohydride reduced nanoparticles. Subsequently these have been used to load anthracycline ring antibiotic doxorubicin hydrochloride. The drug loaded on these nanoparticles showed enhanced cytotoxic effects on human glioma cell lines LN‐18 and LN‐229.
Acceleration Effect of an Allylic Hydroxy Group on Ring‐Closing Enyne Metathesis of Terminal Alkynes: Scope, Application, and Mechanistic Insights
Authors: Imahori Tatsushi , Ojima Hidetomo , Yoshimura Yuichi , Takahata Hiroki
Published: October 2008

An interesting acceleration effect of an allylic hydroxy group on ring‐closing enyne metathesis has been found. Ring‐closing enyne metathesis of terminal alkynes possessing an allylic hydroxy group proceeded smoothly without the ethylene atmosphere generally necessary to promote the reaction. The synthesis of (+)‐isofagomine with the aid of this efficient reaction has been demonstrated. Mechanistic studies of the acceleration effect were also carried out. Results of NMR studies suggested that the reaction proceeded via an “ene‐then‐yne” pathway. Kinetic studies indicated switching of the rate‐determining step as a consequence of the presence of an allylic hydroxy group. These results suggest acceleration of the reentry step of Ru‐carbene species by the allylic hydroxy group.
Diamantelektroden in der dezentralen Abwasserbehandlung – elektrochemischer Abbau des chemischen Sauerstoffbedarfs organisch hochbelasteter Härtereiabwässer
Authors: Dittmar T. , Schmalz V. , Worch E. , Fischer D.
Published: October 2008

Ein elektrochemisches Verfahren zur dezentralen Behandlung von organisch hochbelasteten Industrieabwässern wird hier vorgestellt. Dazu wurden Diamantelektroden in verschiedenen diskontinuierlichen Laborreaktoren eingesetzt sowie der Einfluss der Stromdichte (8 – 66 mA/cm2) auf den Abbau des chemischen Sauerstoffbedarfs (CSB) untersucht. Dieser ließ sich mit Hilfe eines mathematischen Modells beschreiben. Das Verfahren ermöglichte die Einhaltung der Direkteinleitungskriterien.
Childhood and adolescent cancer survival in the US by race and ethnicity for the diagnostic period 1975‐1999
Authors: Linabery Amy M. , Ross Julie A.
Published: October 2008

BACKGROUND.

Survival trends provide a measure of improvement in detection and treatment over time. In the current study, updated childhood and adolescent cancer survival statistics are presented, overall and among demographic subgroups, including Hispanics, for whom to the authors' knowledge national rates have not been previously reported. These results extend those provided by the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program in their detail and interpretation.

METHODS.

Survival trends of primary cancers in children and adolescents (ages birth to 19 years) were evaluated using SEER 9 data. Five‐year and 10‐year relative survival rates across 5‐year (1975‐1979, 1985‐1989, and 1995‐1999) and 10‐year (1975‐1984 and 1985‐1994) cohorts were compared via Z‐tests. Annual percent change (APC) in survival was computed via weighted least‐squares regression. Rates in Hispanic children and adolescents were compared with those in non‐Hispanic whites and blacks (SEER 13, 1995‐1999).

RESULTS.

Five‐year survival rates increased significantly overall (1975‐1979: 63% vs 1995‐1999: 79%; P < .0001) and for nearly all histologic types examined; increases were greatest for ependymoma (+37%; P < .0001) and non‐Hodgkin lymphoma (+34%; P < .0001). Hispanic children and adolescents had somewhat poorer 5‐year rates than non‐Hispanic whites overall (74% vs 81%; P < .0001) and for Ewing sarcoma, leukemia, central nervous system tumors, and melanoma. Ten‐year rates also increased significantly overall (1975‐1984: 61% vs 1985‐1994: 72%; P < .0001) and for a majority of cancer types. The largest improvements were noted for acute lymphoblastic leukemia (+19%; P < .0001) and non‐Hodgkin lymphoma (+19%; P < .0001).

CONCLUSIONS.

Observed trends reinforce the need for resources devoted to advancing treatment modalities, reducing disparities among racial/ethnic groups and adolescents, and providing long‐term care of survivors. Cancer 2008. © 2008 American Cancer Society.
A pilot study of cognitive behaviour therapy for panic disorder augmented by panic surfing
Authors: Lamplugh Claire , Berle David , Milicevic Denise , Starcevic Vladan
Published: October 2008

This pilot study reports the outcome of cognitive behaviour therapy for panic disorder augmented by panic surfing. This treatment approach encourages acceptance of feelings rather than control of symptoms and anxiety, at the same time also targeting catastrophic misinterpretations, bodily vigilance and safety‐seeking behaviours. Eighteen participants completed a brief group treatment for panic disorder incorporating psychoeducation, panic surfing, interoceptive exposure, graded exposure and cognitive restructuring. Significant improvements occurred over the course of this treatment and were maintained at a 1‐month follow‐up. Results suggest that cognitive behaviour therapy augmented by panic surfing may be effective in the treatment of panic disorder, but there is a need for controlled studies and investigation of the relative contribution of its various components. Copyright © 2008 John Wiley & Sons, Ltd.
Using the Steepened Plasma Profile and Wave Breaking Threshold in Laser‐Plasma Interaction
Authors: Zobdeh P. , Sadighi‐Bonabi R. , Afarideh H. , Yazdani E. , Rezaei Nasirabad R.
Published: October 2008

In this work we evaluate the interaction of high intense laser beam with a steepened density profile. During laser interaction with underdense plasma by freely expanding plasma regime, modification of density profile is possible. In this paper we have investigated the ultra short laser pulse interaction with nonisothermal and collisionless plasma. We consider self–focusing as an effective nonlinear phenomenon that tends to increase when the laser power is more than critical rate. By leading the expanded plasma to a preferred location near to critical density, laser reflection is obtained, so the density profile will be locally steepened. The electromagnetic fields are evaluated in this new profile. We show the amplitude and period of electrical field oscillation are increased by reducing the steepened scale length. Also our numerical results identify that by reducing the steepened scale length, the electrical field is increased to wave breaking threshold limit. This high gradient electrical field causes the effective beam loading during the wave breaking phenomenon. The wave breaking can be the initial point for other acceleration regime as cavity or channel guiding regime. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Longitudinal Dust Lattice Shock Wave in a Strongly Coupled Complex Dusty Plasma
Authors: Ghosh S.
Published: October 2008

The effect of hydrodynamical damping that arises due to the irreversible processes within the system have been studied on 1D nonlinear longitudinal dust lattice wave (LDLW) in homogeneous strongly coupled complex (dusty) plasma. Analytical investigation shows that the nonlinear wave is governed by Korteweg‐de Vries Burgers' equation. This hydrodynamical damping induced dissipative effect is responsible for the Burgers' term that causes the generation of shock wave in dusty plasma crystal. Numerical investigation on the basis of the glow‐discharge plasma parameters reveal that LDLW exhibits both oscillatory and monotonic shock. The shock is compressive in nature and its strength decreases (increases) with the increase of the shielding parameter κ (characteristic length L). The effects of dust‐neutral collision are also discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transverse Optical Diagnostics for Intense Focused Heavy Ion Beams
Authors: Varentsov D. , Fertman A. D. , Turtikov V. I. , Ulrich A. , Wieser J. , Fortov V. E. , Golubev A. A. , Hoffmann D. H. H. , Hug A. , Kulish M. , Mintsev V. , Ni P. A. , Nikolaev D. , Sharkov B. Yu. , Shilkin N. , Ternovoi V. Ya. , Udrea S.
Published: October 2008

Beam‐induced fluorescence of dense gas targets has been studied for its application to measure the transverse intensity distribution of energetic focused heavy ion beams. Mechanisms of light emission are discussed on the basis of measured wavelength‐ and time‐resolved light emission of argon. Gas pressures from 10 mbar up to 1 bar have been used. Transverse beam intensity profiles of 200 – 400 AMeV 238U pulses from the heavy ion synchrotron SIS‐18 at the Gesellschaft für Schwerionenforschung, Darmstadt, Germany with up to 5 · 109 particles per pulse focused to a sub‐millimeter spot have been recorded with argon and helium as target gases. Beam profiles recorded at the ArII lines by an optical filter resulted in the narrowest, most realistic beam diameters. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient and Flexible Solid‐Phase Synthesis of N‐Hydroxypolyamine Derivatives
Authors: Méret Michaël , Bienz Stefan
Published: October 2008

Orthogonally protected, N‐hydroxylated, linear tri‐ and tetra‐amines were efficiently synthesised on Merrifield resin, which was modified with a phenethyl bromide linker. The polyamine frameworks were convergently prepared “from the centre” with reductive aminations and nucleophilic substitutions to elongate the polyamine backbone. The required N‐hydroxy groups were introduced during the cleavage of the polyamine derivatives from the resin through Cope elimination.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
An Overview of Syntheses of Apogalanthamine Analogues and 7‐Aza Derivatives of Steganacin and Steganone
Authors: Appukkuttan Prasad , Van der Eycken Erik
Published: October 2008

A concise and critical overview of the developments in the synthesis of apogalanthamine analogues and steganacin and steganone 7‐aza analogues over the last four decades is presented. These amaryllidaceae alkaloid analogues bear a 5,6,7,8‐tetrahydrodibenz[c,e]azocine skeleton, and are well known for their diverse and potent biological activities. This microreview will briefly glance over the history and early developments in the field at the beginning, and will, in the latter parts, concentrate on the recent synthetic developments in the synthesis of the title molecules. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Unsymmetrical Biaryls by Palladium‐Catalyzed Coupling of Aryl Halides with Internal Reduction
Authors: Satyanarayana Gedu , Maier Martin E.
Published: October 2008

Aryl bromides containing a (1,4,5,6‐tetrahydro‐6‐oxopyridin‐3‐yl)methyl substituent can be coupled with aryl halides yielding unsummetrical biaryls. In the course of this process, the cyclic enamide is oxidized to the 2(1H)‐pyridinone. The reaction proceeds by a six‐membered palladacycle resulting from allylic C–H bond activation of the cyclic enamide, leading to a six‐membered palladacycle. A subsequent transmetalation reaction with an aryl‐Pd‐X intermediate eventually leads to mixed biaryls by reductive elimination and β‐hydride elimination. The best yields were obtained with 2 equiv. of aryl halide. The required substrates were prepared from bromoiodobenzenes by a sequence consisting of a Heck reaction with allyl alcohol, enamine formation, Michael addition to ethyl acrylate, and heterocycle formation with benzylamine.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of Yb Complexes with Amino‐Acid‐Armed Ligands for Direct Asymmetric Tandem Aldol Reduction Reactions
Authors: Stodulski Maciej , Jaźwiński Jarosław , Mlynarski Jacek
Published: October 2008

A synthetic route to a series of C2‐symmetric chiral ligands armed with selectively protected amino acids have been developed with the aim to study the potential of the corresponding Yb(III) complexes for enantioselective direct aldol reactions. These ligands, which contain chiral bis(ester) or bis(amide) moieties, were readily prepared in enantiomerically pure form by the reaction of (S,S)‐hydrobenzoin or (S,S)‐diphenylethylenediamine with various chiral amino acids. In this article, the asymmetric aldol‐reduction reaction leading to 1,3‐diols (known as the aldol–Tishchenko reaction) has been performed with an elaborated family of ligands. This unique tandem reaction was catalysed by chiral Yb complexes that promote both the aldol reaction of unactivated carbonyl compounds and the Evans–Tishchenko reduction of the aldol intermediates. 1,3‐anti‐Diols with three stereogenic centers have been isolated as a result of the condensation of aliphatic ketones with aromatic aldehydes with up to 64 % ee. Additional detailed investigations of the nature of the binding of both class of ligands have also been carried out with high‐resolution 1H‐, 13C‐, and 14N‐NMR techniques.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
DFT/MM Study on Copper‐Catalyzed Cyclopropanation – Enantioselectivity with No Enthalpy Barrier
Authors: Drudis‐Solé Galí , Maseras Feliu , Lledós Agustí , Vallribera Adelina , Moreno‐Mañas Marcial
Published: October 2008

The enantioselectivity in the reaction of [Cu(adam‐box)(CHCO2Me)] {adam‐box = 2,2′‐isopropylidenebis[(4R)‐(1‐adamantyl)‐2‐oxazoline]} with Ph2C=CH2 was analyzed computationally by ONIOM(B3LYP:UFF) calculations. The lack of transition states in the potential‐energy surface precludes the use of conventional approaches and requires the definition of reaction paths in an approximate Gibbs free‐energy surface. The procedure is time consuming and intrinsically less accurate than the usual approaches based on enthalpic energy surfaces, but it produces results in reasonable agreement with experiment, which furthermore allow identification of the key interactions responsible for chiral discrimination.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)