bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Terminal Web‐Like Structure in Cortical Lens Fibers: Architecture and Functional Assessment
Authors: Al‐Ghoul Kristin J. , Lindquist Timothy P. , Kirk Spencer S. , Donohue Sean T.
Published: January 2011

Confocal image of posterior segments of cortical lens fibers which abut to form the typical inverted‐Y suture pattern. The sutural domains are flanked on either side by a prominent ‘terminal web’ containing actin, myosin and fodrin.
Development of the Genital Duct System in the Protandrous Black Porgy, Acanthopagrus schlegeli
Authors: Lee Mong‐Fong , Huang Jing‐Duan , Chang Ching‐Fong
Published: February 2011

Protandrous black porgies, Acanthopagrus schlegeli, have a striking life cycle, which includes early sex differentiation, bisexual gonads, and a male‐to‐female sex change at three years of age. We found novel features of and insights into the development of the genital duct system in relation to the gonadal stage during early gonadal development and natural sex change. We found that the genital ducts developed at 16–20 weeks of age during sex differentiation. The gonad developed “ovarian cavity cracks” and became “four‐stranded” during the first prespawning period and then proceeded to the development of genital ducts before 1 year of age. Two ovarian cavities of the paired gonads combined, developed, and extended caudally to form the oviduct, making up the inner duct of the genital ducts. The testicular main cavities also extended and fused together to form the outer duct of the genital duct system, that is, the sperm duct. The coexistence of an outer sperm duct and an inner oviduct constituted a unique “double cannula genital duct” structure. Gradually the inferior walls of the oviduct intermingled with those of the sperm duct, and the circular lumen of the sperm duct changed into an “M‐shaped canal.” Finally, the sperm duct and oviduct separated completely at the distal part of genital duct system. During natural sex change, the male reproductive passage regressed and degenerated and was replaced by connective tissue. The oviduct arrested as a blunt end during male phase and, finally, extended and connected to the genital pore during the female phase. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Toward Comprehensive Analysis of the Galectin Network in Chicken: Unique Diversity of Galectin‐3 and Comparison of its Localization Profile in Organs of Adult Animals to the Other Four Members of this Lectin Family
Authors: Kaltner Herbert , Kübler Dieter , López‐Merino Lara , Lohr Michaela , Manning Joachim C. , Lensch Martin , Seidler Joerg , Lehmann Wolf D. , André Sabine , Solís Dolores , Gabius Hans‐Joachim
Published: February 2011

Characterization of all members of a gene family established by gene divergence is essential to delineate distinct or overlapping expression profiles and functionalities. Their activity as potent modulators of diverse physiological processes directs interest to galectins (endogenous lectins with β‐sandwich fold binding β‐galactosides and peptide motifs), warranting their study with the long‐term aim of a comprehensive analysis. The comparatively low level of complexity of the galectin network in chicken with five members explains the choice of this organism as model. Previously, the three proto‐type chicken galectins CG‐1A, CG‐1B, and CG‐2 as well as the tandem‐repeat‐type CG‐8 had been analyzed. Our study fills the remaining gap to determine gene structure, protein characteristics and expression profile of the fifth protein, that is, chimera‐type chicken galectin‐3 (CG‐3). Its gene has a unique potential to generate variants: mRNA production stems from two promoters, alternative splicing of the form from the second transcription start point (tsp) can generate three mRNAs. The protein with functional phosphorylation sites in the N‐terminus generated by transcription from the first tsp (tsp1CG‐3) is the predominant CG‐3 type present in adult tissues. Binding assays with neoglycoproteins and cultured cells disclose marked similarity to properties of human galectin‐3. The expression and localization profiles as well as proximal promoter regions have characteristic features distinct from the other four CGs. This information on CG‐3 completes the description of the panel of CGs, hereby setting the stage for detailed comparative analysis of the entire CG family, e.g., in embryogenesis. Anat Rec, , 2011. © 2011 Wiley‐Liss, Inc.
Multiple objective optimization of the fleet sizing problem for road freight transportation
Authors: Żak Jacek , Redmer Adam , Sawicki Piotr
Published: February 2011

A fleet sizing problem (FSP) in a road freight transportation company with heterogeneous fleet and its own technical back‐up facilities is considered in the paper. The mathematical model of the decision problem is formulated in terms of multiple objective mathematical programming based on queuing theory. Technical and economical criteria as well as interests of different stakeholders are taken into account in the problem formulation. The solution procedure is composed of two steps. In the first one, a sample of Pareto‐optimal solutions is generated by an original program called MEGROS. In the second step, this set is reviewed and evaluated, according to the Decision Maker's (DM's) model of preferences. The evaluation of solutions is carried out with an application of an interactive multiple criteria analysis method, called Light Beam Search (LBS). Finally, the DM selects the most desirable, compromise solution. Copyright © 2011 John Wiley & Sons, Ltd.
Quantification of 1‐13C‐l‐methionine in rat serum with hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry and its application in pharmacokinetic study
Authors: Xu Ying , Huang Xiao , Nie Xiuli , Yang Li , Yan Weili , Wang Zhengtao , Wang Changhong , Hu Zhibi
Published: February 2011

A rapid, selective and sensitive hydrophilic interaction liquid chromatography (HILIC) coupled with tandem mass spectrometry (MS/MS) method was developed to determine 1‐13C‐l‐methionine in rat serum. Proteins in serum were precipitated using acetonitrile and the supernatant was separated after centrifugation. 1‐13C‐l‐phenylalnine was used as the internal standard. HILIC–tandem mass spectrometry analysis was performed on a hydrophilic interaction silica column (TSK‐GEL AMIDE‐80) using a linear gradient elution system, acetonitrile−5 mm ammonium acetate containing 0.1% formic acid and multiple reaction monitoring mode for 1‐13C‐l‐methionine and 1‐13C‐l‐phenylalnine. The assay was validated with a linear range between 10 and 150 ng mL−1 (r ≥ 0.99) and a lower limit of quantification of 10 ng mL−1, calculated with weighted (1/x2) least squares linear regression. The RSD of intra‐day precision was smaller than 3.6% and the inter‐day RSD less than 6.5%, while the average recovery was 100.48% with an RSD of accuracy within 2.9%, determined from quality control samples. The HILIC‐MS/MS method was fully validated and successfully applied to the in vivo pharmacokinetic study of stable‐isotope 1‐13C‐l‐methionine in rats. Copyright © 2011 John Wiley & Sons, Ltd.
Constructing the stereotype of immigrants' criminality: Accounts of fear and risk in talk about immigration to Greece
Authors: Figgou Lia , Sapountzis Antonis , Bozatzis Nikos , Gardikiotis Antonis , Pantazis Pavlos
Published: January 2011

This paper explores the discursive construction of immigrants' criminality in interview accounts obtained by a sample of Greek people in Thessaloniki (Northern Greece). Analysis, which adopts a discursive approach to stereotypes and category construction, indicates that fear and insecurity on the part of Greek people are represented as a sine qua non consequence of immigration to Greece. Two different lines of argument are used to account for the arousal of fear. According to the first, fear constitutes a corollary of a widespread stereotypical representation of immigrants as criminals. The stereotype of immigrants' criminality is considered to be ill‐warranted and it is attributed to the media or to other unspecified people. According to another, more regularly used, line of argument, however, fear is predicated upon the sordid living conditions of immigrants in Greece which make the probability of them being involved in illegal acts particularly high. In this case, fear is seen to derive from a ‘rational estimate’ of the probability of immigrant's involvement in criminal acts. Nested within the discourse of ‘risk’ the stereotypical image of immigrants' criminality is sustained and used to account for the need to protect the ‘ingroup’ from ‘immigrant groups’ through immigration control and surveillance. Copyright © 2011 John Wiley & Sons, Ltd.
First survey of the three gene polymorphisms (PON1 Q192R, eNOS E298D and eNOS C‐786T) potentially associated with coronary artery spasm in African populations and comparison with worldwide data
Authors: Fujihara Junko , Yasuda Toshihiro , Kawai Yasuyuki , Morikawa Norihiro , Arakawa Kenichiro , Koda Yoshiro , Soejima Mikiko , Kimura‐Kataoka Kaori , Takeshita Haruo
Published: February 2011

Three polymorphisms, Paraoxonase 1 (PON1) Q192R (C/G), endothelial nitric oxide synthase (eNOS) E298D (G/T) and eNOS T‐786C have been suggested to be potentially associated with coronary artery spasm in Japanese patients. Data on worldwide populations are needed to clarify whether these associations could hold true for other populations. However, few data are available especially in Africans, spasm of which has been suggested to be an aetiology of myocardial infarction. Therefore, these polymorphisms were investigated in three Africans, Ovambos (n = 123), Ghanians (n = 118) and Xhosas (n = 96), together with Japanese (n = 96), by using polymerase chain reaction‐restriction fragment length polymorphism analysis. Genotype‐distributions of all these SNPs in African populations were significantly different from those in Caucasians, whereas were similar to those in Japanese population. African populations exhibit relatively higher frequency of spasm‐associated G192 allele in PON1 Q192R being similar to Japanese population, however frequencies of spasm‐associated T298 allele and –C786 allele in SNP eNOS E298D and T‐786C, respectively, were conversely lower in Africans than Caucasians. Although healthy subjects have been recruited in this study, these findings may provide genetic background for elucidation of aetiology of spasm. Copyright © 2011 John Wiley & Sons, Ltd.
Participation of the liver gluconeogenesis in the glibenclamide‐induced hypoglycaemia in rats
Authors: Geisler Sandonaid Andrei , Felisberto‐Junior Antonio Machado , Tavoni Thauany Martins , Carrara Márcia Aparecida , Curi Rui , Bazotte Roberto Barbosa
Published: February 2011

We previously demonstrated an increased liver gluconeogenesis (LG) during insulin‐induced hypoglycaemia. Thus, an expected effect of sulphonylureas induced hypoglycaemia (SIH) could be the activation of LG. However, sulphonylureas infused directly in to the liver inhibits LG. Considering these opposite effects we investigated herein LG in rats submitted to SIH. For this purpose, 24 h fasted rats that received glibenclamide (10 mg kg−1) were used (SIH group). Control group received oral saline. Glycaemia at 30, 60, 90, 120 and 150 min after oral administration of glibenclamide were evaluated. Since the lowest glycaemia was obtained 120 min after glibenclamide administration, this time was chosen to investigate LG in situ perfused livers. The gluconeogenesis from precursors that enters in this metabolic pathway before the mitochondrial step, i.e. L‐alanine (5 mM), L‐lactate (2 mM), pyruvate (5 mM) and L‐glutamine were decreased (p < 0·05). However, the gluconeogenic activity using glycerol (2 mM), which enters in the gluconeogenesis after the mitochondrial step was maintained. Taken together, the results suggest that the inhibition of LG promoted by SIH overcome the activation of this metabolic pathway promoted by IIH and could be attributed, at least in part, to its effect on mitochondrial function. Copyright © 2011 John Wiley & Sons, Ltd.
An activator of PHD2, KRH102140, decreases angiogenesis via inhibition of HIF‐1α
Authors: Nepal Manoj , Gong Young‐Dae , Park Young Ran , Soh Yunjo
Published: February 2011

Hypoxia‐inducible transcription factors (HIFs) play a pivotal role in the response of cells to hypoxia. HIFs are dimers of an oxygen‐sensitive α‐subunit (HIF‐1α or HIF‐2α), and a constitutively expressed β‐subunit. In normoxia, HIF‐1α is destabilized by post‐translational hydroxylation of Pro‐564 and Pro‐402 by a family of oxygen‐sensitive dioxygenases. Prolyl hydroxylation leads to von Hippel–Lindau protein‐dependent ubiquitination and rapid degradation of HIF‐1α. We previously reported that KRH102053, an activator of PHD2, rapidly decreased HIF‐1α and eventually inhibited angiogenesis. Here, we report a potent activator of PHD2, KRH102140, which has a structure similar to KRH102053. KRH102140 more efficiently suppressed HIF‐1α than KRH102053 in human osteosarcoma cells under hypoxia. Furthermore, KRH102140 decreased the mRNA levels of HIF‐regulated downstream target genes associated with angiogenesis and energy metabolism such as vascular endothelial growth factor, adrenomedullin, Glut1, aldolase A, enolase 1 and monocarboxylate transporter 4. KRH102140 also inhibited tube formation in human umbilical vein endothelium cells. The results suggest that KRH102140 has potential therapeutic effects in alleviating various diseases associated with HIFs. Copyright © 2011 John Wiley & Sons, Ltd.
Ventricular septal defect closure in a small children with the Amplatzer Duct Occluder II
Authors: Tahlawi Mohammad El , Kammache Issam , Fraisse Alain
Published: February 2011

Transcatheter technique for muscular ventricular septal defect closure remains challenging, particularly in small patients. We report the successful use of the low profile Amplatzer Duct Occluder II for multiple ventricular septal defect closure in an infant with D‐transposition of the great arteries, status postpulmonary artery banding. The multiple apical ventricular septal defects were successfully closed with two Amplatzer Duct Occluder II and one Amplatzer Muscular Ventricular Septal Defect Occluder during two interventional catheterizations. The patient subsequently underwent successful surgical repair. © 2011 Wiley‐Liss, Inc.
Migration of fractured renal artery stent
Authors: Tanaka Akihito , Takahashi Saeko , Saito Shigeru
Published: February 2011

An 80‐year‐old man received stent implantation for severe stenosis of the right renal artery. During the procedure, the proximal edge of the stent was successfully positioned at the ostium of the renal artery. After 6 months, follow‐up renal angiography showed transverse stent fracture without restenosis. The proximal part of the fractured stent had moved and protruded into the abdominal aorta. Three years later, the proximal part of the fractured stent had migrated from the renal artery to the wall of infrarenal aorta. This is the first reported case of stent migration of the renal artery caused by a complete transverse stent fracture. © 2011 Wiley‐Liss, Inc.
Hard–soft modeling parallel factor analysis to solve equilibrium processes
Authors: Sajjadi S. M. , Abdollahi H.
Published: February 2011

PARAFAC model is the most famous model for analyzing three‐way data. However, this method does not converge to chemically meaningful solutions when applied to three‐way problems involving rank overlap profiles at least in one mode. Rank overlap can be simply found where components have similar spectral profiles or analytes appearing in identical proportions throughout an experiment. However, an appropriate selection of the initial parameters and constraints such as non‐negativity and unimodality can still make PARAFAC model useful in this regard. Although such constraints reduce rotational freedom in PARAFAC solution, they are generally insufficient to wholly eliminate the rotational problem. The goal of the present paper is to incorporate hard modeling constraint in the soft‐modeled PARAFAC algorithm to overcome non‐uniqueness problem in the equilibrium processes involving linearly dependent factors at least in one mode. The hard constraint is introduced to force some or all of the concentration profiles to fulfill an equilibrium model that is refined at each iteration cycle of the optimization process of PARAFAC. The proposed approach is called hard–soft PARAFAC (HSPARAFAC). When the rank overlap species obeys equilibrium model in HSPARAFAC, the unique results are obtained even in the presence of non‐modeled interferences. The new modification in the treatment of equilibrium data sets yields more satisfactory results than the exclusive PARAFAC algorithm. Simulated and real examples with rank overlap problem are used to confirm this statement. Copyright © 2011 John Wiley & Sons, Ltd.
Combination of kernel PCA and linear support vector machine for modeling a nonlinear relationship between bioactivity and molecular descriptors
Authors: Fu Guang‐Hui , Cao Dong‐Sheng , Xu Qing‐Song , Li Hong‐Dong , Liang Yi‐Zeng
Published: February 2011

In this paper, a two‐step nonlinear classification algorithm is proposed to model the structure–activity relationship (SAR) between bioactivities and molecular descriptors of compounds, which consists of kernel principal component analysis (KPCA) and linear support vector machines (KPCA + LSVM). KPCA is used to remove some uninformative gradients such as noises and then exactly capture the latent structure of the training dataset using some new variables called the principal components in the kernel‐defined feature space. LSVM makes full use of the maximal margin hyperplane to give the best generalization performance in the KPCA‐transformed space. The combination of KPCA and LSVM can effectively improve the prediction performance compared with the linear SVM as well as two nonlinear methods. Three datasets related to different categorical bioactivities of compounds are used to evaluate the performance of KPCA + LSVM. The results show that our algorithm is competitive. Copyright © 2011 John Wiley & Sons, Ltd.
Broadening Deoxysugar Glycodiversity: Natural and Engineered Transaldolases Unlock a Complementary Substrate Space
Authors: Rale Madhura , Schneider Sarah , Sprenger Georg A. , Samland Anne K. , Fessner Wolf‐Dieter
Published: February 2011

The majority of prokaryotic drugs are produced in glycosylated form, with the deoxygenation level in the sugar moiety having a profound influence on the drug’s bioprofile. Chemical deoxygenation is challenging due to the need for tedious protective group manipulations. For a direct biocatalytic de novo generation of deoxysugars by carboligation, with regiocontrol over deoxygenation sites determined by the choice of enzyme and aldol components, we have investigated the substrate scope of the F178Y mutant of transaldolase B, TalBF178Y, and fructose 6‐phosphate aldolase, FSA, from E. coli against a panel of variously deoxygenated aldehydes and ketones as aldol acceptors and donors, respectively. Independent of substrate structure, both enzymes catalyze a stereospecific carboligation resulting in the D‐threo configuration. In combination, these enzymes have allowed the preparation of a total of 22 out of 24 deoxygenated ketose‐type products, many of which are inaccessible by available enzymes, from a [3×8] substrate matrix. Although aliphatic and hydroxylated aliphatic aldehydes were good substrates, D‐lactaldehyde was found to be an inhibitor possibly as a consequence of inactive substrate binding to the catalytic Lys residue. A 1‐hydroxy‐2‐alkanone moiety was identified as a common requirement for the donor substrate, whereas propanone and butanone were inactive. For reactions involving dihydroxypropanone, TalBF178Y proved to be the superior catalyst, whereas for reactions involving 1‐hydroxybutanone, FSA is the only choice; for conversions using hydroxypropanone, both TalBF178Y and FSA are suitable. Structure‐guided mutagenesis of Ser176 to Ala in the distant binding pocket of TalBF178Y, in analogy with the FSA active site, further improved the acceptance of hydroxypropanone. Together, these catalysts are valuable new entries to an expanding toolbox of biocatalytic carboligation and complement each other well in their addressable constitutional space for the stereospecific preparation of deoxysugars.
A New Phase in the Binary Iron Nitrogen System?—The Prediction of Iron Pernitride, FeN2
Authors: Wessel Michael , Dronskowski Richard
Published: February 2011

Among numerous different AB2 structures with the hypothetical composition FeN2, the structures lying lowest in energy have been determined by a series of density‐functional electronic‐structure calculations. The most likely FeN2 phase crystallizing in the space group R$\bar 3$m must be considered an iron pernitride incorporating binuclear NN units (d=1.275 Å) with an anionic charge of 2−. This high‐pressure magnetic phase with a bulk modulus of about 192 GPa and an iron saturation moment of approximately 1.68 μB should already form at a pressure of 17 GPa at an assumed reaction temperature of 1000 K. Besides bonding FeN interactions, antibonding NN and FeFe interactions exist in the crystal structure.
Taxol®. Hoffnung gegen Krebs
Authors: Schäfer Bernd
Published: February 2011

Krebserkrankungen kennt man seit der Antike. Die Entdeckung von Paclitaxel und die Entwicklung von Taxol(r) ist sowohl für die Naturstoffsynthese als auch für die Krebsforschung ein bedeutender Meilenstein. Unmittelbar nach der Entdeckung seiner einzigartigen pharmakologischen Eigenschaften wurde die klinische Versorgung mit Material einer Verbindung mit solch anspruchsvoller Struktur ein ernsthaftes Problem. Namhafte Arbeitskreise lieferten eine Reihe von Totalsynthesen, aber der klinische Bedarf wurde von Anfang an zunächst durch Extraktion der Eibenrinde und später durch Partialsynthese gedeckt. Seit den 1990er Jahren stellt man Paclitaxel zusätzlich durch Pflanzenzellfermentation her.
Mit Licht Protonen pumpen
Authors: Feil Sylvia
Published: February 2011

Bakterien können Sonnenlicht nutzen, um Protonengradienten an den sie umhüllenden Membranen aufzubauen. Die dazu nötigen Pumpen sind in der Membran eingelagerte Proteine, lichtgetriebene Protonenpumpen wie das Bakteriorhodopsin. Am Transport der Protonen ist Wasser im Innenraum der Proteine entscheidend beteiligt.
Eiskalte Fische
Authors: Feil Sylvia
Published: February 2011

Der antarktische Seehecht Dissostichus mawsoni lebt dauerhaft bei Temperaturen um den Gefrierpunkt. Sein Blut hat einen Gefrierpunkt von –0, 9 °C. Hieraus isolierten Bochumer Chemiker um Martina Havenith gemeinsam mit amerikanischen Kollegen Glykoproteine, die Modell standen, um auf molekularer Ebene den Schutz vor gefrierendem Wasser aufzuklären.
März – Alaaf und Helau
Authors: Hatscher Deike , Knirsch Sandra
Published: February 2011

Die Klimax der fünften Jahreszeit am Rosenmontag und Veilchendienstag beschert uns einen Rahmen, um alle Register der Schminkkunst zu ziehen. Grundlage sind die typischen Produkte der dekorativen Kosmetik in den wildesten Farben, die einer phantasiereichen Hautbemalung praktisch keine Grenzen mehr setzten.
Arsenat‐Verwerter: anders oder nur angepasst?
Authors: Groß Michael
Published: February 2011

Die Meldung der NASA erregte viel Aufsehen: Forscher hatten offenbar Mikroben entdeckt, die eins der sechs essentiellen Elemente, Phosphor, durch Arsen ersetzen können. Doch ob diese Giftschlucker wirklich Arsenat in ihre DNA einbauen, ist noch höchst ungewiss.
Role of Age, Sex, and Race on Cardiac and Total Mortality Associated With Super Bowl Wins and Losses
Authors: Kloner Robert A. , McDonald Scott A. , Leeka Justin , Poole W. Kenneth
Published: January 2011

Background

Total and cardiac mortality rates in Los Angeles County, Califorina, increased after the 1980 Super Bowl loss (SBL), but there was an overall reduction in total mortality after the 1984 Super Bowl win (SBW).

Hypothesis

We hypothesized that age, sex, and race may have played a role in the Super Bowl related differences in death rates.

Methods

We compared mortality rates for SB‐related days with non‐SB control days assessing differences in demographics. We ran regression models predicting daily death rates per 100,000 including SB variable versus non‐SB control days for age, sex, race, and interactions for these covariates.

Results

After the SBL, daily death rates increased for both males and females. People aged ≥65 years had a larger absolute increase in all cause mortality during the SBL days compared with those aged <65 years, with significant interaction between age and SBL‐variable for all‐cause and cardiac‐related mortality. Whites and Hispanics had increased death rates on SBL days. There were trends suggesting less death in older patients and females associated with the SBW.

Conclusion

A SBL triggered increased deaths in both men and women and especially in older patients, whereas a SBW reduced death more in those aged ≥65 years and in women. Copyright © 2011 Wiley Periodicals, Inc.

The authors have no funding, financial relationships, or conflicts of interest to disclose.
Response Surface Approach for the Bisorption of Ag(I) by Macrofungus Pleurotus platypus
Authors: Das Devlina , Das Nilanjana
Published: January 2011

Response surface methodology (RSM) employing the three‐level Box–Behnken factorial design was used to optimize the biosorption of Ag(I) by the macrofungus Pleurotus platypus. The initial Ag(I) concentration (100–300 mg/L), pH (3.0–9.0), and biomass dosage (1.0–5.0 g/L) were chosen as the process variables for the optimization. A coefficient of determination (R2) value (0.99), model F value (234.18), and its low p‐value (F < 0.0001) along with the lower value of coefficient of variation (2.44%) indicated the fitness of response surface quadratic model during the present study. At the optimum pH (6.0), initial metal concentration (220 mg/L), and biomass dosage (3.0 g/L), the model predicted 46.7 mg/g Ag(I) uptake and an experimental 46.77 mg/g Ag(I) uptake by P. platypus was obtained. This is the first report on Ag(I) sorption by P. platypus using statistical experimental design employing RSM which may be helpful towards the treatment of industrial effluent containing silver.
Time‐Dependent FRET with Single Enzymes: Domain Motions and Catalysis in H+‐ATP Synthases
Authors: Bienert Roland , Zimmermann Boris , Rombach‐Riegraf Verena , Gräber Peter
Published: February 2011

H+‐ATP synthases are molecular machines which couple transmembrane proton transport with ATP synthesis from ADP and inorganic phosphate by a rotational mechanism. Single‐pair fluorescence resonance energy transfer (spFRET) in single molecules is a powerful tool to analyse conformational changes. It is used to investigate subunit movements in H+‐ATP synthases from E. coli (EF0F1) and from spinach chloroplasts (CF0F1) during catalysis. The enzymes are incorporated into liposome membranes, and this allows the generation of a transmembrane pH difference, which is necessary for ATP synthesis. After labelling of appropriate sites on different subunits with fluorescence donor and acceptor, the kinetics of spFRET are measured. Analysis of the EFRET traces reveals rotational movement of the ε and γ subunits in 120° steps with opposite directions during ATP synthesis and ATP hydrolysis. The stepped movement is characterized by a 120° step faster than 1 ms followed by a rest period with an average dwell time of 15 ms, which is in accordance with the turnover time of the enzyme. In addition to the three conformational states during catalysis, also an inactive conformation is found, which is observed after catalysis.
Pd/PdO functionalization of SnO2 nanowires and ZnO nanotetrapods
Authors: De Zorzi C. , Rossetto G. , Calestani D. , Zha M. Z. , Zappettini A. , Lazzarini L. , Villani M. , Habra N. El , Zanotti L.
Published: February 2011

Tin oxide (SnO2) and zinc oxide (ZnO) nanostructures are widely studied because of their peculiar physical and chemical properties and the large number of possible application fields. Surface functionalization of these materials is a very important topic because it is a powerful tool for modifying or tuning their properties, in order to better match the device requests. For example, palladium/palladium oxide (Pd/PdO) nanoparticles are often used to enhance selectivity of chemoresistive gas sensing properties of metal‐oxide nanostructures. SnO2 nanowires and ZnO nanotetrapods have been grown on large areas by a combination of metal evaporation and controlled oxidation, while a MOCVD (Metal Organic Chemical Vapor Deposition) process has been chosen in order to deposit Pd/PdO nanoparticles on the surface of the obtained oxide nanostructures. Samples morphology, structure and composition have been studied by means of SEM and TEM microscopy, EDS microanalysis and X‐Ray diffraction. The different results, obtained as a function of the synthesis and annealing parameters, are discussed focusing the attention to the experimental conditions that allowed the authors to obtain an optimal “spotted” coverage of oxide nanostructures, which is often required for gas sensing application. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamic modeling of DC–DC converters with peak current control in double‐stage photovoltaic grid‐connected inverters
Authors: Garcerá Gabriel , González‐Medina Raúl , Figueres Emilio , Sandia Jesús
Published: January 2011

In photovoltaic (PV) double‐stage grid‐connected inverters a high‐frequency DC–DC isolation and voltage step‐up stage is commonly used between the panel and the grid‐connected inverter. This paper is focused on the modeling and control design of DC–DC converters with Peak Current mode Control (PCC) and an external control loop of the PV panel voltage, which works following a voltage reference provided by a maximum power point tracking (MPPT) algorithm. In the proposed overall control structure the output voltage of the DC–DC converter is regulated by the grid‐connected inverter. Therefore, the inverter may be considered as a constant voltage load for the development of the small‐signal model of the DC–DC converter, whereas the PV panel is considered as a negative resistance. The sensitivity of the control loops to variations of the power extracted from the PV panel and of its voltage is studied.

The theoretical analysis is corroborated by frequency response measurements on a 230 W experimental inverter working from a single PV panel. The inverter is based on a Flyback DC–DC converter operating in discontinuous conduction mode (DCM) followed by a PWM full‐bridge single‐phase inverter. The time response of the whole system (DC–DC + inverter) is also shown to validate the concept. Copyright © 2011 John Wiley & Sons, Ltd.
Performance study of mobile WiMAX network with changing scenarios under different modulation and coding
Authors: Bhunia Suman , Misra Iti Saha , Sanyal Salil K. , Kundu Anindita
Published: January 2011

WiMAX—the Worldwide Interoperability for Microwave Access is a promising technology for offering high‐speed data, video and multimedia services over mobile platform evolving toward all IP networks. The increasing demand of WiMAX for VoIP and high‐speed multimedia is due to the simplicity of installation and cost reduction compared with the traditional wired DSL cable. The challenges to service providers lie with the Quality of Service (QoS) under varying fading environment while at the same time maximizing for resource utilization. In this paper, a rigorous and comprehensive performance study of mobile WiMAX has been made with respect to adaptive modulation and coding techniques considering the variation in the speed of the mobile, path‐loss, scheduling services and application type for comparing with the fixed type of modulations. The OPNET 14.5.A modeler for WiMAX platform has been used as simulator for adaptation at the physical layer of the transmission in WiMAX OFDMA structure. Observation reveals that dynamic adaptation of modulation and coding schemes based on channel condition enables better QoS while consuming low overall bandwidth of the system. Copyright © 2011 John Wiley & Sons, Ltd.
Polycomb group gene Bmi1 plays a role in the growth of thymic epithelial cells
Authors: Guo Yun , Miyazaki Masaki , Itoi Manami , Satoh Rumi , Iwama Atsushi , Amagai Takashi , Kawamoto Hiroshi , Kanno Masamoto
Published: January 2011

Polycomb group gene Bmi1 plays an essential role in HSCs and the BM microenvironment. Recent reports also pointed to the importance of Bmi1 in thymocyte development. However, little is known about its role in the development of the thymic microenvironment. Here, we examined the function of Bmi1 in thymic epithelial cells (TECs) by using the engraftment of fetal thymus (FT) lobes under the kidney capsule. The engrafted Bmi1−/− FT lobes were clearly smaller and the number of thymocytes in these lobes was significantly decreased compared with control FT lobes. Analysis of the cell cycle status of TECs in the reconstituted lobes revealed that the reduction of thymus size in Bmi1−/− FT grafts was caused by less proliferation of TECs during the early expansion stage. Unlike cases with hematopoietic stem cells or thymocytes, the deletion of p16Ink4a and p19Arf could not restore the defects in Bmi1−/− TEC, indicating a distinct role for Bmi1 in TECs. In conclusion, epigenetic regulator polycomb group gene Bmi1 plays a role in the thymic microenvironment in a regeneration process by supporting TEC growth, and thereby contributes to the control of thymus size for T‐cell growth in mice.
XAFS and DFT Characterisation of Protonated Reduced Fe Hydrogenase Analogues and Their Implications for Electrocatalytic Proton Reduction
Authors: Cheah Mun Hon , Best Stephen P.
Published: February 2011

The relationship between the structures of reduced, protonated diiron compounds relevant to the diiron subsite of the Fe‐hydrogenase H cluster, [2Fe]H, and the rate of electrocatalytic proton reduction is explored by a combination of experimental and computational approaches. Analysis of the X‐ray absorption fine structure (XAFS) of the two‐electron, two‐proton product of [Fe(CO)3]2(μ‐PPh2)2 (DP) shows distortions of the primary coordination environment of the Fe centre that result from the trans influence of the terminally bound hydrido ligand. The difference in Fe–C(O) bond lengths for the CO groups cis and trans to the hydrido ligand is similarly predicted by density functional theory, although there is relatively poor agreement between the magnitude of the difference obtained by XAFS and DFT methods. The calculated energies of the cis and trans stereoisomers of DP‐H2 with both hydrido ligands normal to the FeP2 plane (axial:axial) are within 0.5 kcal mol–1 of each other and lower, by approximately 4.5 kcal mol–1, than those of the axial:equatorial isomer. Similar trends in the relative energies are found for the hydrido forms of [Fe(CO)3]2[μ‐PhP(CH2)3PPh] (3P). The rates of dihydrogen elimination from 3P‐H2 and analogues with ethanedithiolate and propanedithiolate bridging ligands (2S‐H2 and 3S‐H2) have been re‐evaluated by using recent DFT calculations of equilibrium constants and reduction potentials. The rate constants 4–8, 2–7 and 1.5–4 s–1 for dihydrogen elimination from the two‐electron, two‐proton analogues of 2S, 3S and 3P, respectively, for reactions conducted with p‐toluenesulfonic acid fall within a narrow range and are consistent with reactions following a similar path but inconsistent with the different transition states proposed for dihydrogen elimination from 2S‐H2 and 3S‐H2.
Oxidovanadium(V) Complexes with Aminoethanol Bis(phenolate) [O,N,O,O′] Ligands: Preparations, Structures, N‐Dealkylation and Condensation Reactions
Authors: Wichmann Oula , Sopo Harri , Lehtonen Ari , Sillanpää Reijo
Published: February 2011

The reactions between [VO(acac)2] (acac– = acetylacetonate ion) or [VO(OPr)3] and trianionic tetradentate N,N‐bis(2‐methylene‐4,6‐alkylphenolate)aminoethanolate ligands, [L13– (4,6‐dimethyl), L23– (4‐methyl, 6‐tert‐butyl), L33– (4‐tert‐butyl, 6‐methyl), L43– (4,6‐di‐tert‐butyl)], afford mononuclear complexes [VO(L1)] (1) and [VO(L2)] (2) with a trigonal bipyramidal coordination sphere around the VV ion, or dinuclear octahedral complexes [V2O2(L3)2] (3) and [V2O2(L4)2] (4). In methanol an adduct with the formula [VO(L1)(MeOH)]·1/2MeOH (5) is obtained. According to multinuclear NMR spectroscopy all those complexes have a mononuclear structure in CDCl3 solutions. In wet polar solvents complex 1 reacts with water and N‐dealkylation occurs producing 3,5‐dimethylsalicyl alcohol, which condensates with 1 and forms a new oxidovanadium complex 6. An ether bond links 3,5‐dimethylsalicyl alcohol to the L13– ligand. To support the reaction mechanism, we have found that in dry acetonitrile 1 reacts directly with salicyl alcohol forming compound 7, which is similar to 6. All compounds 1–7 have been characterized by elemental analysis, multinuclear NMR and X‐ray diffraction.
Total Syntheses of Rhodiolosides A and D and of Sachalinols A–C
Authors: Simon Kristina , Jones Peter G. , Lindel Thomas
Published: February 2011

The glucosylated monoterpenoids (–)‐rhodioloside A and (–)‐rhodioloside D from the roseroot (Rhodiola rosea) have been synthesized for the first time. Glucosylation with tetrapivaloylglucosyl bromide proved superior to the use of tetraacetylglucosyl bromide or glucosyl iodides. Acid‐catalyzed cyclization of a homoglycidol‐type geraniol derivative afforded the monoterpenoid tetrahydrofuran (+)‐sachalinol C from Rhodiola sachalinensis. The absolute configuration of (+)‐sachalinol C requires revision. (–)‐Sachalinol A and (–)‐sachalinol B were also obtained.
In vitro screening of taxol, an anticancer drug produced by the fungus, Colletotrichum capsici
Authors: Kumaran Rangarajulu Senthil , Jung Heehoon , Kim Hyung Joo
Published: February 2011

The fungus Colletotrichum capsici was isolated from the diseased fruits of Chilli plant, Capsicum annuum. The isolated test fungus was identified by its morphological and molecular characteristic features. For the first time, the fungus was screened for the production of taxol on modified liquid medium. The presence of taxol was confirmed by the spectroscopic and chromatographic methods of analyses. The amount of taxol produced by this fungus was quantified by HPLC. The maximum amount of fungal taxol production was recorded as 687 μg/L. The production rate was 13 740‐fold higher than that, previously reported for the fungus Taxomyces andreanae. The extracted fungal taxol showed a strong cytotoxic activity in an in vitro culture of human cancer cells indicating that the increase in taxol concentration induces increased cell death. A PCR‐based screening for taxadiene synthase (ts), a unique gene in the formation of the taxane skeleton, confirmed the molecular blueprint for taxol biosynthesis. The results show that the fungus C. capsici is an excellent candidate for an alternate source of taxol supply and can serve as a potential species for genetic engineering to enhance the production of taxol to a higher level.
Evaluation of three‐dimensional modal pushover analysis for unsymmetric‐plan buildings subjected to two components of ground motion
Authors: Reyes Juan C. , Chopra Anil K.
Published: February 2011

The accuracy of the three‐dimensional modal pushover analysis (MPA) procedure in estimating seismic demands for unsymmetric‐plan buildings due to two horizontal components of ground motion, simultaneously, is evaluated. Eight low‐and medium‐rise structures were considered. Four intended to represent older buildings were designed according to the 1985 Uniform Building Code, whereas four other designs intended to represent newer buildings were based on the 2006 International Building Code. The median seismic demands for these buildings to 39 two‐component ground motions, scaled to two intensity levels, were computed by MPA and nonlinear response history analysis (RHA), and then compared. Even for these ground motions that deform the buildings significantly into the inelastic range, MPA offers sufficient degree of accuracy. It is demonstrated that PMPA, a variant of the MPA procedure, for nonlinear systems is almost as accurate as the well‐known standard response spectrum analysis procedure is for linear systems. Thus, for practical applications, the PMPA procedure offers an attractive alternative to nonlinear RHA, whereby seismic demands can be estimated directly from the (elastic) design spectrum. In contrast, the nonlinear static procedure specified in the ASCE/SEI 41‐06 Standard is demonstrated to grossly underestimate seismic demands for some of the unsymmetric‐plan buildings considered. Copyright © 2011 John Wiley & Sons, Ltd.
Decoding short binary cyclic codes via covering polynomials
Authors: Sung Wonjin , Coffey John T.
Published: January 2011

The paper concerns the covering polynomial method of decoding cyclic codes. This is an easily‐implementable, robust, and low‐complexity decoding algorithm. The determination of the exact complexity of the algorithm is a difficult open problem. In this paper several methods for constructing minimal sets of covering polynomials are proposed for the case R < 2/τ, where τ is the number of errors to be corrected. Complete closed form specifications of the minimal set are given for the case where τ is even, and a computationally efficient procedure presented for general τ is shown to be optimal in many cases (and conjectured to be globally optimal). These results are sufficient to determine the exact minimal number of covering monomials for all binary cyclic codes of length up to 127 with τ < 9. Closed form specifications are available for the covering polynomial set for all such codes.
Complexity/performance tradeoffs in multistage decoders
Authors: Lee Wing‐Man , Kschischang Frank R.
Published: January 2011

This paper describes suboptimal decoding methods for multilevel block‐encoded modulation schemes. These decoding methods can achieve large coding gains with relatively low decoding complexity, and operate, in part, by decoding a supercode of the code to be decoded. By decomposing the multilevel codes in various ways, a wide range of performance/complexity tradeoff points can be obtained. Introducing syndrome checking can further reduce the average decoding complexity with no degradation in performance. Both analysis and extensive simulation results confirm that a given coding gain can be achieved with significantly smaller decoding complexity than Viterbi decoding.
Error and work estimates for high‐order elements
Authors: Löhner Rainald
Published: January 2011

Error and work estimates for high‐order elements are derived. The comparison of error and work estimates shows that for relative accuracy in the 1% range, which is typical of engineering interest, it may prove very difficult to improve on linear elements. As expected, the estimates also show that the optimal order of element in terms of work and storage demands depends on the desired relative accuracy. Copyright © 2011 John Wiley & Sons, Ltd.
A dual‐weighted trust‐region adaptive POD 4‐D Var applied to a finite‐volume shallow water equations model on the sphere
Authors: Chen X. , Akella S. , Navon I. M.
Published: January 2011

In this paper we study solutions of an inverse problem for a global shallow water model controlling its initial conditions specified from the 40‐yr ECMWF Re‐analysis (ERA‐40) data sets, in the presence of full or incomplete observations being assimilated in a time interval (window of assimilation) with or without background error covariance terms. As an extension of the work by Chen et al. (Int. J. Numer. Meth. Fluids 2009), we attempt to obtain a reduced order model of the above inverse problem, based on proper orthogonal decomposition (POD), referred to as POD 4D‐Var for a finite volume global shallow water equation model based on the Lin–Rood flux‐form semi‐Lagrangian semi‐implicit time integration scheme. Different approaches of POD implementation for the reduced inverse problem are compared, including a dual‐weighted method for snapshot selection coupled with a trust‐region POD adaptivity approach. Numerical results with various observational densities and background error covariance operator are also presented. The POD 4‐D Var model results combined with the trust‐region adaptivity exhibit similarity in terms of various error metrics to the full 4D Var results, but are obtained using a significantly lesser number of minimization iterations and require lesser CPU time. Based on our previous and current work, we conclude that POD 4‐D Var certainly warrants further studies, with promising potential of its extension to operational 3‐D numerical weather prediction models. Copyright © 2011 John Wiley & Sons, Ltd.
A coordinate transformation method for numerical solutions of the electric double layer and electroosmotic flows in a microchannel
Authors: Yao Zhang , Jiankang Wu , Bo Chen
Published: January 2011

The electric double layer (EDL) and electroosmotic flows (EOFs) constitute the theoretical foundations of microfluidics. Numerical solution is one of the effective means of analysis in microfluidics. In general, it is difficult to obtain an accurate numerical solution of complex EOFs because of multiphysical interactions and locally high gradients. In this paper, a new coordinate transformation method is proposed to numerically solve the Poisson–Boltzmann, Navier–Stokes and Nernst–Planck equations to study the EDL and complex EOFs in a microchannel. A series of numerical examples is presented including cases of a homogeneous, discontinous wall electric potential and a locally high wall potential. A systematic comparison of numerical solutions with and without the coordinate transformation is carried out. The numerical results indicate that the coordinate transformation effectively decreases the gradient of the electric potential, ion concentration and electroosmotic velocity in the vicinity of the solid wall, and greatly improves the stability and convergency of the solution. In a transformed coordinate system with a coarse grid, the numerical solutions can be as accurate as those in the original coordinate system with a refined grid. Copyright © 2011 John Wiley & Sons, Ltd.
Prognostic factors in patients with high‐risk locally advanced salivary gland cancers treated with surgery and postoperative radiotherapy
Authors: Feinstein Trevor M. , Lai Stephen Y. , Lenzner Diana , Gooding William , Ferris Robert L. , Grandis Jennifer R. , Myers Eugene N. , Johnson Jonas T. , Heron Dwight E. , Argiris Athanassios
Published: January 2011

Background

This study was designed to identify the factors associated with the outcome after standard treatment with surgery and postoperative radiotherapy (RT) for locally advanced salivary gland cancers.

Methods

We conducted a retrospective review of patients with salivary gland cancers registered in the University of Pittsburgh databases from 1990 to 2006.

Results

A total of 74 patients were analyzed. Histologic types included salivary duct carcinoma, 24%; adenoid cystic carcinoma, 23%; and adenocarcinoma, 19%; N2, 39%; N0–1, 58%; and major salivary gland origin, 80%. With a median follow‐up of 4.1 years, the 5‐year recurrence‐free survival (RFS) was 49%, and the 5‐year overall survival (OS) was 55%. The 5‐year local RFS was 76% and the 5‐year distant RFS was 60%. Using Cox‐regression analysis, advanced N classification (N2) was the only significant predictor of both RFS and OS.

Conclusion

The long‐term survival of patients with high‐risk, locally advanced salivary gland cancers is unsatisfactory. Advanced nodal disease is strongly associated with patient outcome and should be considered as a stratification factor in future trials in locally advanced salivary gland cancers. © 2011 Wiley Periodicals, Inc. Head Neck, 2011