bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Diterpenes from Gorgonian Corals
Authors: Berrue Fabrice , Kerr Russell G.
Published: June 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Infinite Coordination Polymer Nano‐ and Microparticle Structures
Authors: Spokoyny Alexander M. , Kim Dongwoo , Sumrein Abdelqader , Mirkin Chad A.
Published: June 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Hydrogen Storage in Metal—Organic Frameworks
Authors: Murray Leslie J. , Dinca Mircea , Long Jeffrey R.
Published: June 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Thin Films of Metal—Organic Frameworks
Authors: Zacher Denise , Shekhah Osama , Woell Christof , Fischer Roland A.
Published: June 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Selective Gas Adsorption and Separation in Metal—Organic Frameworks
Authors: Li Jian‐Rong , Kuppler Ryan J. , Zhou Hong‐Cai
Published: June 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Human angiomotin‐like 1 associates with an angiomotin protein complex through its coiled‐coil domain and induces the remodeling of the actin cytoskeleton
Authors: Gagné Valérie , Moreau Julie , Plourde Mélodie , Lapointe Mathieu , Lord Mathieu , Gagnon Édith , Fernandes Maria J. G.
Published: June 2009

Angiostatin is a potent inhibitor of angiogenesis. One mechanism through which angiostatin inhibits angiogenesis is by binding to the cell surface protein p80‐angiomotin. The p80‐angiomotin protein promotes angiogenesis, in part, by conferring a hypermigratory phenotype to endothelial cells. Although p80‐angiomotin is extensively characterized, less is known about the related protein angiomotin‐like 1. We report that angiomotin‐like 1 forms part of a protein complex containing p80‐angiomotin. Structure‐function studies revealed that angiomotin‐like 1 associates with this p80‐angiomotin‐containing complex via its coiled‐coil domain. Since p80‐angiomotin plays a role in cell migration, a process that involves the remodeling of the actin cytoskeleton, we then addressed the hypothesis that angiomotin‐like 1 may interact with the cytoskeleton. Immunofluorescence studies reveal that angiomotin‐like 1 not only co‐localizes with filamentous actin but also significantly modifies the architecture of the actin cytoskeleton. Regarding migration, angiomotin‐like 1 increases the velocity of migration and decreases the persistence of migration directionality. Together these observations strongly suggest that angiomotin‐like 1 is involved in actin‐cytoskeleton‐based processes, in part, via its interaction with a p80‐angiomotin‐containing complex and the actin cytoskeleton. These findings have important implications for angiogenesis‐driven disease since angiomotin and angiomotin‐like 1 are both expressed in capillaries. Cell Motil. Cytoskeleton 2009. © 2009 Wiley‐Liss, Inc.
Cover Picture: Photonucleophilic Addition of the ε‐Amino Group of Lysine to a Triflusal Metabolite as a Mechanistic Key to Photoallergy Mediated by the Parent Drug (ChemMedChem 7/2009)
Authors: Montanaro Sara , Lhiaubet‐Vallet Virginie , Jiménez M. Consuelo , Blanca Miguel , Miranda Miguel Angel
Published: June 2009

The cover picture shows the proposed mechanism for a drug (triflusal) to trigger a photoallergic response. Photobinding of the active metabolite, 2‐hydroxy‐4‐trifluoromethylbenzoic acid (HTB), to poly‐L‐lysine is used here as a model system to gain further insight into the molecular basis of triflusal‐mediated photoallergy. The interaction between HTB and the protein, human serum albumin (HSA), was investigated by fluorescence and laser flash photolysis to monitor inclusion into the protein‐binding sites through variation in the excited‐state properties. For more details, see the Full Paper by M. A. Miranda et al. on p. 1196 ff.

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Continuity of optimal transport maps and convexity of injectivity domains on small deformations of 𝕊2
Authors: Figalli Alessio , Rifford Ludovic
Published: June 2009

Given a compact Riemannian manifold, we study the regularity of the optimal transport map between two probability measures with cost given by the squared Riemannian distance. Our strategy is to define a new form of the so‐called Ma‐Trudinger‐Wang condition and to show that this condition, together with the strict convexity on the nonfocal domains, implies the continuity of the optimal transport map. Moreover, our new condition, again combined with the strict convexity of the nonfocal domains, allows us to prove that all injectivity domains are strictly convex too. These results apply, for instance, on any small C4‐deformation of the 2‐sphere. © 2009 Wiley Periodicals, Inc.
Smallest singular value of a random rectangular matrix
Authors: Rudelson Mark , Vershynin Roman
Published: June 2009

We prove an optimal estimate of the smallest singular value of a random sub‐Gaussian matrix, valid for all dimensions. For an N × n matrix A with independent and identically distributed sub‐Gaussian entries, the smallest singular value of A is at least of the order √N − √n − 1 with high probability. A sharp estimate on the probability is also obtained. © 2009 Wiley Periodicals, Inc.
Targeted13C–13C Distance Measurements in a Microcrystalline Protein via J‐Decoupled Rotational Resonance Width Measurements
Authors: van der Wel Patrick C. A. , Eddy Matthew T. , Ramachandran Ramesh , Griffin Robert G.
Published: June 2009

Targeting the hydrophobic core: Solid‐state NMR rotational resonance width experiments are performed to measure13C–13C distances between aromatic and aliphatic residues that make up the hydrophobic core of streptococcal protein G (see picture). Their value in structure calculations and the effect of chemical shift anisotropy at high magnetic field are discussed.

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Rotational resonance width (R2W) magic‐angle spinning (MAS) NMR experiments are performed to measure13C–13C distances in the hydrophobic core of the microcrystalline model protein GB1. Such inter‐residue distances are of particular value in NMR structure determinations. The experiments are done at a Larmor frequency of 750 MHz1H where the contribution of13C chemical shift anisotropy (CSA) to the R2transfer mechanism is significant. To minimize line broadening in the 2D spectra, we employ a combination of even/odd isotopic labeling with [1,3‐13C] glycerol, and J‐decoupling in the indirect dimension. This results in high‐precision distance measurements between aromatic side chains of three tyrosine residues and distant methyl groups in the hydrophobic core of the protein. Even in the absence of information on the relative orientation of the shift tensors, we obtain relatively high precision data, which can be further improved by additional constraints on the tensor orientations.
Site‐Dependent Excited‐State Dynamics of a Fluorescent Probe Bound to Avidin and Streptavidin
Authors: Fürstenberg Alexandre , Kel Oksana , Gradinaru Julieta , Ward Thomas R. , Emery Daniel , Bollot Guillaume , Mareda Jiri , Vauthey Eric
Published: June 2009

Sensing protein environment: The femtosecond fluorescence dynamics of a molecular probe attached to avidin and streptavidin (see figure) depends markedly on the location of the probe and on the protein. These differences reflect not only the protein primary and tertiary structures but also the effect of the surrounding water molecules.

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The excited‐state dynamics of biotin–spacer–Lucifer‐Yellow (LY) constructs bound to avidin (Avi) and streptavidin (Sav) was investigated using femtosecond spectroscopy. Two different locations in the proteins, identified by molecular dynamics simulations of Sav, namely the entrance of the binding pocket and the protein surface, were probed by varying the length of the spacer. A reduction of the excited‐state lifetime, stronger in Sav than in Avi, was observed with the long spacer construct. Transient absorption measurements show that this effect originates from an electron transfer quenching of LY, most probably by a nearby tryptophan residue. The local environment of the LY chromophore could be probed by measuring the time‐dependent polarisation anisotropy and Stokes shift of the fluorescence. Substantial differences in both dynamics were observed. The fluorescence anisotropy decays analysed by using the wobbling‐in‐a‐cone model reveal a much more constrained environment of the chromophore with the short spacer. Moreover, the dynamic Stokes shift is multiphasic in all cases, with a ∼1 ps component that can be ascribed to diffusive motion of bulk‐like water molecules, and with slower components with time constants varying not only with the spacer, but with the protein as well. These slow components, which depend strongly on the local environment of the probe, are ascribed to the motion of the hydration layer coupled to the conformational dynamics of the protein.
Characterization of the Biomechanical Properties of T4 Pili Expressed by Streptococcus pneumoniae—A Comparison between Helix‐like and Open Coil‐like Pili
Authors: Castelain Mickaël , Koutris Efstratios , Andersson Magnus , Wiklund Krister , Björnham Oscar , Schedin Staffan , Axner Ove
Published: June 2009

Adhesion strategies: Open coil‐like T4 pili use different adhesion strategies in the presence of external forces (see figure) compared to the helix‐like P pili. When exposed to significant forces, bacteria expressing helix‐like pili remain attached by distributing the external force among a multitude of pili, whereas bacteria expressing open coil‐like pili sustain large forces primarily by their multitude of binding adhesins.

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Bacterial adhesion organelles, known as fimbria or pili, are expressed by Gram‐positive as well as Gram‐negative bacteria families. These appendages play a key role in the first steps of the invasion and infection processes, and they therefore provide bacteria with pathogenic abilities. To improve the knowledge of pili‐mediated bacterial adhesion to host cells and how these pili behave under the presence of an external force, we first characterize, using force measuring optical tweezers, open coil‐like T4 pili expressed by Gram‐positive Streptococcus pneumoniae with respect to their biomechanical properties. It is shown that their elongation behavior can be well described by the worm‐like chain model and that they possess a large degree of flexibility. Their properties are then compared with those of helix‐like pili expressed by Gram‐negative uropathogenic Escherichia coli (UPEC), which have different pili architecture. The differences suggest that these two types of pili have distinctly dissimilar mechanisms to adhere and sustain external forces. Helix‐like pili expressed by UPEC bacteria adhere to host cells by single adhesins located at the distal end of the pili while their helix‐like structures act as shock absorbers to dampen the irregularly shear forces induced by urine flow and to increase the cooperativity of the pili ensemble, whereas open coil‐like pili expressed by S. pneumoniae adhere to cells by a multitude of adhesins distributed along the pili. It is hypothesized that these two types of pili represent different strategies of adhering to host cells in the presence of external forces. When exposed to significant forces, bacteria expressing helix‐like pili remain attached by distributing the external force among a multitude of pili, whereas bacteria expressing open coil‐like pili sustain large forces primarily by their multitude of binding adhesins which presumably detach sequentially.
A Novel Heavy‐Atom Label for Side‐Specific Peptide Iodination: Synthesis, Membrane Incorporation and X‐ray Reflectivity
Authors: Schneggenburger Philipp E. , Beerlink André , Worbs Brigitte , Salditt Tim , Diederichsen Ulf
Published: June 2009

A novel iodine peptide label for X‐ray analysis of membrane‐active peptide structures is applied to solid‐phase peptide synthesis. The resulting pore‐structured labeled peptide as well as a non‐labeled reference were reconstituted in lipid bilayer stacks (see scheme). The results indicate the exhibition of a membrane‐spanning β5.6‐double helical peptide structure and illustrate the quality of the new label.

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Structural parameters, such as conformation, orientation and penetration depth of membrane‐bound peptides and proteins that may function as channels, pores or biocatalysts, are of persistent interest and have to be probed in the native fluid state of a membrane. X‐ray scattering in combination with heavy‐atom labeling is a powerful and highly appropriate method to reveal the position of a certain amino acid residue within a lipid bilayer with respect to the membrane normal axis up to a resolution of several Ångstrøm. Herein, we report the synthesis of a new iodine‐labeled amino acid building block. This building block is intended for peptide incorporation to provide high intensities for electron density difference analysis of X‐ray reflectivity data and improve the labeling potential for the lipid bilayer head‐group and water region. The novel building block as well as the commercially available non‐iodinated analogue, required for X‐ray scattering, was implemented in a transmembrane peptide motif via manual solid‐phase peptide synthesis (SPPS) following the fluorenylmethyloxycarbonyl (Fmoc)‐strategy. The derived peptides were reconstituted in lipid vesicles as well as in highly aligned multilamellar lipid stacks and investigated via circular dichroism (CD) and X‐ray reflectivity. Thereby, it has been revealed that the bulky iodine probe neither causes conformational change of the peptide structure nor lamellar disordering of the membrane complexes.
Microscopic and Spectroscopic Observations in the Bio‐Nanoworld
Authors: Hinterdorfer Peter , Pohl Peter , Schütz Gerhard
Published: June 2009

Biophysics in Linz: In February biophysicists from across the world converged on Linz for two biophysical conferences. The city which is the Cultural Capital of Europe 2009, provided the perfect environment for fruitful discussions on single‐molecule techniques in biophysics, bio‐nanotechnology, cell biology, and drug discovery.

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Platelet‐activating factor‐stimulated production of reactive oxygen species in ovarian granulosa cells from periovulatory follicles
Authors: Xu Jinxian , Krüger Burkhard , Vernunft Andreas , Löhrke Berthold , Viergutz Torsten
Published: June 2009

The platelet‐activating factor (PAF) is a proinflammatory lipid present in the fluid of ovarian Graafian follicle. Ovarian blockage of the PAF receptor (PAFr) reduces ovulations in the rat whereas underlying mechanism is poorly understood. Mural granulosa cells (MGC) were mechanically isolated from the theca interna of bovine periovulatory follicle. The mRNA abundance for PAFr, progesterone receptor and cyclooxygenase‐2 were measured by real‐time PCR. Cytosolic calcium (Ca2+) concentration was assayed by microscopy using Fura‐2 AM as indicator, 8‐isoprostaglandin F2α(8‐isoPGF2α) by an ELISA kit. Fluorescent products arising from intracellular oxidation of hydroethidine (HE) and dihydrorhodamine (DHR) were quantified by flow cytometry. The cells expressed PAFr mRNA and PAFr protein and responded to cPAF (nonhydrolyzable form of PAF) with a pulsating increase in Ca2+, demonstrating functional PAFr. Elevation of Ca2+was reversed by WEB‐2086, an inverse PAFr agonist. cPAF elevated the level of 8‐isoPGF2αin the medium of MGC cultured with luteinizing hormone (LH). cPAF alone had no significant influence on the oxidation of HE and DHR, or 8‐isoPGF2αlevel. In MGC from vital periovulatory follicle, PAF and LH signaling plays an important role in regulating the production of excessive oxidants. Blockage of PAFr seems to interfere with these regulatory processes essential for ovulation. © 2009 International Society for Advancement of Cytometry
Simultaneous flow cytometric quantification of plant nuclear DNA contents over the full range of described angiosperm 2C values
Authors: Galbraith David W.
Published: June 2009

Flow cytometry provides a rapid, accurate, and simple means to determine nuclear DNA contents (C‐value) within plant homogenates. This parameter is extremely useful in a number of applications in basic and applied plant biology; for example, it provides an important starting point for projects involving whole genome sequencing, it facilitates characterization of plant species within natural and agricultural settings, it allows facile identification of engineered plants that are euploid or that represent desired ploidy classes, it points toward studies concerning the role of C‐value in plant growth and development and in response to the environment and in terms of evolutionary fitness, and, in uncovering new and unexpected phenomena (for example endoreduplication), it uncovers new avenues of scientific enquiry. Despite the ease of the method, C‐values have been determined for only around 2% of the described angiosperm (flowering plant) species. Within this small subset, one of the most remarkable observations is the range of 2C values, which spans at least two orders of magnitude. In determining C‐values for new species, technical issues are encountered which relate both to requirement for a method that can provide accurate measurements across this extended dynamic range, and that can accommodate the large amounts of debris which accompanies flow measurements of plant homogenates. In this study, the use of the Accuri C6 flow cytometer for the analysis of plant C‐values is described. This work indicates that the unusually large dynamic range of the C6, a design feature, coupled to the linearity of fluorescence emission conferred by staining of nuclei using propidium iodide, allows simultaneous analysis of species whose C‐values span that of almost the entire described angiosperms. © 2009 International Society for Advancement of Cytometry
Disease‐specific biomarker discovery by aptamers
Authors: Ulrich Henning , Wrenger Carsten
Published: June 2009

RNA and DNA aptamers developed by an in vitro selection process, Systematic Evolution of Ligands by EXponential enrichment (SELEX), comprise a novel class of high‐affinity and specific capture agents, which can be easily modified for cytometry and in vivo applications. A novel application of this technique (Cell SELEX) explores the expression of cell surface epitopes that differ between two given cell types or between healthy and diseased cells. Using whole cells as targets, aptamer libraries can be identified that bind to biomarkers expressed by target cells and not by any other cells. Aptamers have been developed that specifically interact with cell surface epitopes of trypanosomes or distinguish between the differences in molecular signature of somatic and cancer cells. Aside from its use for target cell identification by image and flow cytometry and laser‐scanning microscopy, aptamers can be used for ligand‐mediated purification and identification of their binding proteins in target cell membranes. In this review, we discuss an approach for the development of aptamers targeting parasite‐derived surface proteins of Trypanosoma and Plasmodium. © 2009 International Society for Advancement of Cytometry
Mauerwerkstrockenlegung: Analyse – Methoden – Überprüfung
Authors: Balak Michael
Published: June 2009

Aufgrund des äußerst komplexen Fachgebietes der Mauerwerkstrockenlegung und den damit verbundenen häufigen Fehlschlägen in der Praxis sind vor Durchführung von Trockenlegungsmaßnahmen eine umfangreiche Bauwerksdiagnose und die Erstellung eines Sanierungskonzeptes sowie in weiterer Folge einer Sanierungsdetailplanung erforderlich. Die Besonderheiten und Anwendungsgrenzen der verschiedenen Horizontalabdichtungsmethoden und der flankierenden Maßnahmen zur Mauerwerkstrockenlegung werden aufgezeigt. Weiterhin wird auf die Überprüfungsmöglichkeiten von Trockenlegungsmaßnahmen hingewiesen.
Massive Bestandsdecken gründerzeitlicher Bausubstanz
Authors: Kolbitsch Andreas
Published: June 2009

Zahlreiche Zustandsbewertungen an Objekten der Gründerzeit, also der Bauphase von ca. 1850 bis 1918, zeigten, dass ab etwa 1870 neuere Typen von Massivdecken unterschiedlichster Ausführung verwendet wurden, wobei unter den sogenannten “Patentdecken” Systeme mit keramischen Füllkörpern vorherrschen. Diese Deckensysteme sind in der älteren und neueren Literatur nur teilweise erfasst, die konstruktive Bewertung setzt daher in vielen Fällen eine genaue Bestandsanalyse voraus.

Der vorliegende Beitrag soll die anhand bisheriger Untersuchungen gewonnenen Erfahrungen aufzeigen und exemplarische Bewertungsansätze vorstellen.
Mauerwerksdruckfestigkeit – Bestimmung bei Bestandsobjekten
Authors: Pech Anton , Zach Franz
Published: June 2009

Zum Nachweis der vertikalen, aber natürlich auch der horizontalen Tragsicherheit von Mauerwerksgebäuden des Bestandes ist es unerlässlich, entsprechende und für das Gesamtobjekt relevante Festigkeitskennwerte zu ermitteln. Diese können entweder direkt in der Bestimmung der charakteristischen Druckfestigkeit und der Scherfestigkeit liegen, werden üblicher Weise jedoch über die Komponentenfestigkeiten und durch Normen gesicherte Beziehungen definiert. Für die Praxis wurden dafür einfache Prüfverfahren entwickelt, die durch zahlreiche Anwendungen erprobt und ständige Kontrollüberprüfungen abgesichert sind.
Mauerwerksverfestigung mittels Kunstharzen
Authors: Pohlplatz Klaus
Published: June 2009

Im Rahmen eines Forschungsprojektes wurden umfangreiche Untersuchungen an Kellerwänden (Bestandmauerwerk) und an Prüfkörpern durchgeführt. Es hat sich gezeigt, dass eine verfestigende Wirkung bei allen Harzen und Bohrlochrastern eintritt. Eine Abdichtungswirkung von organischen Injektionsmitteln gegen kapillar aufsteigende Feuchtigkeit ist bei einem engen Bohrlochraster ebenfalls gegeben. Die Ergebnisse der Untersuchungen zeigen allerdings für die einzelnen Harze und Injektionsraster ein sehr unterschiedliches Bild, so dass eine pauschale Beurteilung der Produkte nicht möglich ist und die Hersteller gefordert sind, genaue Angaben hinsichtlich Bohrlochraster, Injektionsmittelverbrauch und maximalen Durchfeuchtungsgrad zu liefern.
Der Meier Öko‐Kalkstein® als Beispiel einer Produktneuentwicklung im Bereich der Mauersteine aus Beton nach DIN EN 771‐3
Authors: Schrenk Johannes , Maier Martin
Published: June 2009

Mauersteine aus Beton werden seit vielen Jahrzehnten auf dem Markt angeboten und sind sowohl den Planern und Architekten als auch den Verarbeitern und Bauherrn bekannt. Normalerweise bestehen sie aus verschiedenen Gesteinskörnungen und ‐mehlen und werden durch das Bindemittel Zement zusammengehalten, darüber hinaus enthalten sie oft Flugasche oder Recyclingprodukte. Da sich ihre Eigenschaften über die Jahre hinweg nicht sonderlich geändert oder gar verbessert haben, sind sie mit der Zeit oft nur noch für untergeordnete Aufgaben wie Kellermauerwerk, unbeheizte Anbauten, Garagen u. ä. verwendet worden. Obwohl diese Art von Mauersteinen über ein hohes Potenzial in Bezug auf die Zusammensetzung und Struktur und die daraus resultierenden bauphysikalischen Eigenschaften verfügt, gelang es zumeist nicht, sie aus diesem “Dornröschenschlaf” zu wecken und ihr neues Leben einzuhauchen. Dass diese Steinart aber durchaus eine Zukunft besitzt, zeigt eine Entwicklung der letzten Jahre, die die Firma Meier Betonwerke GmbH aus Lauterhofen in der Oberpfalz (Bayern) vorangetrieben und durch mehrere bauaufsichtliche Zulassungen im Jahre 2008 zunächst abgeschlossen hat. Der neue Stein nennt sich zu Recht Meier Öko‐Kalkstein® und soll in diesem Beitrag näher beschrieben werden. Er ist zugleich ein Synonym für andere Entwicklungen in dieser Mauerwerksparte, da er auch als Planstein und als Großblock produziert werden kann und damit auch im Trend liegt, da klassisches, kleinformatiges Mauerwerk mit 12‐mm‐Fugen sich seit Jahren auf dem Rückzug befindet.
Einbruchhemmung – Mauerwerk bietet massiven Schutz
Authors: Schwieger Hartmut
Published: June 2009

Alle zwei Minuten passiert in Deutschland ein Einbruch. Die Summe der jährlich durch Einbrüche in Wohnungen und Gewerbe verursachten Schäden beträgt rund 650 Mio. €, davon 410 Mio. € allein im privaten Bereich. Der durchschnittliche Schaden eines Einbruchs im privaten Bereich beträgt dabei rund 1000 € [1]. Bei Gewerbeobjekten beträgt der Durchschnittsschaden ca. 2600 € [2]. Dem vorbeugenden baulichen Einbruchschutz kommt damit hohe Bedeutung zu. Kalksandstein‐Mauerwerk [3] bietet aufgrund seiner hoher Steindruckfestigkeit die Voraussetzung zur Befestigung geeigneter Tür‐ und Fensterelemente.
Vitamin D in diabetes mellitus—a new field of knowledge poised for D‐velopment
Authors: Alfonso B. , Liao E. , Busta A. , Poretsky L.
Published: June 2009

This commentary reviews the current state of knowledge regarding the role of vitamin D in the pathogenesis of diabetes mellitus. In type 1 diabetes mellitus or in adult onset latent autoimmune diabetes (LADA), vitamin D exhibits immunomodulatory actions, influencing the activity of lymphocytes and interleukins. In type 2 diabetes mellitus vitamin D appears to act through different mechanisms, affecting insulin secretion and insulin sensitivity through its effects on the β cells, mediators of inflammation and parathyroid hormone. Much work remains to be done in this new field of knowledge before the role of vitamin D in the pathogenesis of diabetes mellitus is completely understood. Copyright © 2009 John Wiley & Sons, Ltd.
Leptin and endothelin‐1 mediated increased extracellular matrix protein production and cardiomyocyte hypertrophy in diabetic heart disease
Authors: Majumdar Pijush , Chen Shali , George Biju , Sen Subhrojit , Karmazyn Morris , Chakrabarti Subrata
Published: June 2009

Background

We investigated the role of leptin and its interaction with endothelin 1 (ET‐1) in fibronectin (FN) synthesis and cardiomyocyte hypertrophy, two characteristic features of diabetic cardiomyopathy.

Methods

Endothelial cells [human umbilical vein endothelial cells (HUVECs)] were examined for FN production and neonatal rat cardiomyocytes for hypertrophy, following incubation with glucose, ET‐1, leptin and specific blockers. FN, ET‐1, leptin and leptin receptors mRNA expression and FN protein were measured. Myocytes were also morphometrically examined. Furthermore, hearts from streptozotocin‐diabetic rats were analysed.

Results

Glucose caused increased FN mRNA and protein expression in HUVECs and cardiomyocytes hypertrophy along with upregulation of ET‐1 mRNA, leptin mRNA and protein. Glucosemimetic effects were seen with leptin and ET‐1. Leptin receptor antagonist (leptin quadruple mutant) and dual endothelin A endothelin B (ETA/ETB) receptor blocker bosentan normalized such abnormalities. Hearts from the diabetic animals showed hypertrophy and similar mRNA changes.

Conclusion

These data indicate that in diabetes increased FN production and cardiomyocyte hypertrophy may be mediated through leptin with its interaction with ET‐1. Copyright © 2009 John Wiley & Sons, Ltd.
Comparison of insulin detemir and insulin glargine using a basal‐bolus regimen in a randomized, controlled clinical study in patients with type 2 diabetes
Authors: Raskin Philip , Gylvin Titus , Weng Wayne , Chaykin Louis
Published: June 2009

Background

This treat‐to‐target study compared the efficacy and safety of insulin detemir (IDet) and insulin glargine (IGla) in a basal‐bolus (insulin aspart) regimen in type 2 diabetes.

Methods

385 patients were randomized 2 : 1 (IDet : IGla). Non‐inferiority of IDet to IGla was determined by HbA1c 95% CI upper limit <0.4.

Results

IDet and IGla showed similar efficacy in HbA1c reduction at 26 weeks, as the non‐inferiority criterion was met at 26 weeks (LS mean [Det–Gla]: 0.207; 95% CI: 0.0149,0.3995). It appeared that IGla in some cases did better than IDet in terms of HbA1c, but the difference (0.207%) was not clinically meaningful. Based on the CONSORT guideline, non‐inferiority analysis using the LOCF approach was inconclusive regarding possible inferiority of delta 0.4 (LS mean of [Det–Gla]: 0.307; 95% CI: 0.1023, 0.5109). HbA1c decreased significantly from baseline in IDet (−1.1% [26 weeks], −0.9% [LOCF], p < 0.001) and in IGla (−1.3% [26 weeks, LOCF], p < 0.001). Final HbA1c were 7.1% (26 weeks) and 7.3% (LOCF) in IDet, and 6.9% (26 weeks) and 7.0% (LOCF) in IGla. Final FPG were 130 mg/dL (26 weeks) and 135 mg/dL (LOCF) in IDet, and 134 mg/dL (26 weeks) and 137 mg/dL (LOCF) in IGla. There was significantly less weight gain in IDet‐treated patients (1.2 ± 3.96 kg versus 2.7 ± 3.94 kg, p = 0.001). Hypoglycemia risk was comparable between groups. The majority of IDet‐treated patients (87.4%) remained on a once‐daily basal insulin regimen throughout the study.

Conclusions

IDet and IGla were both effective and safe treatments for glycemic control in a basal‐bolus regimen for type 2 diabetes. Clinically significant reductions in HbA1c were achieved in both groups, but with significantly less weight gain in the IDet group at comparable basal insulin dosage. Copyright © 2009 John Wiley & Sons, Ltd.
Paternal deprivation induces dendritic and synaptic changes and hemispheric asymmetry of pyramidal neurons in the somatosensory cortex
Authors: Pinkernelle Josephine , Abraham Andreas , Seidel Katja , Braun Katharina
Published: June 2009

Similar to maternal care, paternal care is a source of neonatal sensory stimulation, which in primates and rodents has been shown to be essential for developing structure and function of sensory cortices. The aim of our study in the biparental rodent Octodon degus was to assess the impact of paternal deprivation on dendritic and synaptic development in the somatosensory cortex. We (i) quantified the amount of paternal care in relation to total parental investment and (ii) compared dendritic and synaptic development of pyramidal neurons in the somatosensory cortex of animals raised by a single mother or by both parents. On the behavioral level we show that paternal care comprises 37% of total parent‐offspring interactions, and that the somatosensory stimulation provided by the fathers primarily consists of huddling, licking/grooming, and playing. On the morphological level we found that, compared with offspring raised by both parents (mother and father), the father‐deprived animals displayed significantly reduced spine numbers on the basal dendrites of pyramidal neurons. Furthermore, paternal deprivation induces hemispheric asymmetry of the dendritic morphology of somatosensory pyramidal neurons. Father‐deprived animals show shorter and less complex basal dendrites in the left somatosensory cortex compared with the right hemisphere. These findings indicate that paternal deprivation results in delayed or retarded dendritic and synaptic development of somatosensory circuits. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009
Gap junctions are involved in cell migration in the early postnatal subventricular zone
Authors: Marins Mônica , Xavier Anna L.R. , Viana Nathan B. , Fortes Fábio S.A. , Fróes Maira M. , Menezes João R.L.
Published: June 2009

The massive migration of neuroblasts and young neurons through the anterior extension of the postnatal subventricular zone (SVZ), known as the rostral migratory stream (RMS) is still poorly understood on its molecular basis. In this work, we investigated the involvement of gap junctional communication (GJC) in the robust centrifugal migration from SVZ/RMS explants obtained from early postnatal (P4) rats. Cells were dye‐coupled in homocellular and heterocellular pairings and expressed at least two connexins, Cx 43 and 45. Treatment with the uncoupler agent carbenoxolone (CBX, 10–100 μM) reversibly reduced outgrowth from SVZ explants, while its inactive analog, glycyrhizinic acid (GZA), had no effect. Consistent with a direct effect on cell migration, time‐lapse video microscopy show that different pharmacological uncouplers cause an abrupt and reversible arrest of cell movement in explants. Our results indicate that GJC is positively involved in the migration of neuroblasts within the SVZ/RMS. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009
Preparation of TiNxO2–x Photoelectrodes with NH3 Under Controllable Middle Pressures for Dye‐Sensitized Solar Cells
Authors: Wang Xin , Yang Yulin , Jiang Zhaohua , Fan Ruiqing
Published: June 2009

As part of our efforts to find a way to control the concentration of N‐doped TiO2, TiNxO2–x powders were prepared by a device of our own design. In this research, photoelectrodes are generated using N‐doped TiO2 materials where the concentrations are adjusted by the amount of NH3 under middle pressure, which is seldom reported. Considerable efforts have been directed to the study of the optical absorption edge that is redshifted towards the visible‐light region. Therefore, N‐doped TiO2 electrodes are characterized by SPS and TPV analyses as experimental and theoretical studies. Experimental results indicate that the band gap of the semiconductor has been narrowed by increasing the concentration of the N‐doped TiO2. The overall conversion efficiency of the solar cell has shown that the photoelectrical properties of the N‐doped TiO2 have greatly improved with different concentrations. It can therefore be concluded that the synthesis route we found through this study is an effective way to adjust the relationship between the concentration and the band gap of the N‐doped TiO2 photoelectrodes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Coupling Radical and Ionic Processes: An Unusual Rearrangement Affords Sugar and C‐Glycoside Derivatives
Authors: Boto Alicia , Hernández Dácil , Hernández Rosendo , Álvarez Eleuterio
Published: June 2009

An unusual scission–rearrangement process, which couples radical and ionic reactions, was observed with galactofuranose derivatives. This one‐pot procedure afforded, in good yields, highly functionalized 1,4‐dioxanes, which could be considered as six‐membered‐ring sugar analogues. The synthesis of C‐glycoside analogues is also possible with this methodology.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Direct Electrochemistry and Electrocatalysis of the Hemoglobin Immobilized on Diazonium‐Functionalized Aligned Carbon Nanotubes Electrode
Authors: Yang Jing , Xu Ying , Zhang Renyi , Wang Yanzhi , He Pingang , Fang Yuzhi
Published: June 2009

A simple and efficient electrochemical method is utilized to functionalize aligned carbon nanotubes (ACNTs) by the electrochemical reduction of 4‐carboxyphenyl diazonium salt. Thus hemoglobin (Hb) molecules were covalently immobilized on the diazonium‐ACNTs surface via carbodiimide chemistry. Direct electrochemistry and bioelectrocatalytic activity of the immobilized Hb were then investigated by cyclic voltammetry (CV) and amperometry techniques. It is showed that the Hb film on the diazonium‐ACNTs electrode had well‐defined redox peaks with a formal potential (E°) at −312 mV (vs. Ag/AgCl), and the Hb‐ACNTs electrode displayed good electrocatalytic activity to H2O2 reduction. Owing to the high Hb covering on the ACNTs surface (Γ*=2.7×10−9 mol cm−2), the catalytic current were significantly improved when compared to the current measured at an Hb‐tangled carbon nanotubes electrode. The Hb‐ACNTs electrode exhibited high sensitivity, long‐term stability and wide concentration range from 40 μM to 3 mM for the amperometric detection of H2O2. The heterogeneous reaction rate constant (ks) was 0.95±0.05 s−1 and the apparent Michaelis–Menten constant (K$\rm{ {_{m}^{app}})}$ was 0.15 mM.
Fabrication of Fe(CN)63− Functionalized PDDA/CdTe Layer‐by‐layer Film with Good Electron Transfer Ability
Authors: Luan Qingfen , Li Jun , Yao Xin
Published: June 2009

(PDDA/CdTe)n layer‐by‐layer (LBL) film immobilized with Fe(CN)63− was fabricated on the gold electrode. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to investigate the electrochemical properties of this film. The peak current of the immobilized Fe(CN)63− increased as the number of the bilayers increased and was proportional to the scan rate. Compared with pure (PDDA/CdTe)n and (PDDA/PSS)n LBL film, Fe(CN)63− immobilized (PDDA/CdTe)n LBL film had good electron transfer ability. The immobility of Fe(CN)63− into the film was attributed to its interaction with Cd2+ on the surface of CdTe QDs. Fe(CN)63− also can interact with other metal ions, which would make Fe(CN)63− release from the film. The concentrations of metal ions will affect the CV response of Fe(CN)63− immobilized LBL film. It has provided a novel prototype of device or sensor for quantitative detection of metal ions.
Potentiometry of Anionic Polyelectrolytes by Quaternary Ammonium Ion‐Selective Electrode with Quaternary Ammonium Ion Added as Probe
Authors: Zheng Xiang‐Yang , Yano Daisaku , Yasui Takashi , Takada Kazutake , Yuchi Akio
Published: June 2009

For potentiometric determination of anionic polyelectrolytes (APEs), the free concentration of water‐soluble quaternary ammonium cation (QA+) added as a probe was measured with a quaternary ammonium ion‐selective electrode. The optimized detection of polyacrylate as one example of APEs demonstrated that the quaternary ammonium ions with a single alkyl group >C15 had large potential changes (−80 mV for C16 and −130 mV for C18) within a concentration range of 10−6–10−4 mol dm−3. The response was rapid (several minutes) and independent of pH>8 and showed no hysteresis. APEs with other anionic functional groups, for example, heparin and poly(4‐styrenesulfonate), were also detected.
Solid‐Contact Reference Electrodes Based on Lipophilic Salts
Authors: Mattinen Ulriika , Bobacka Johan , Lewenstam Andrzej
Published: June 2009

A novel solid‐contact reference electrode (SCRE) for potentiometric measurements is studied. A lipophilic salt was introduced into a PVC membrane by two different approaches, i) using tetra(alkyl)ammonium‐tetra(butyl or phenyl)borate, i.e. a single salt (Φ+Ψ−), and ii) tetra(alkyl)ammonium chloride+potassium tetra(phenyl)borate i.e. two salts (Φ+Cl−) and (K+Ψ−) that presumably form (T(alkyl)A+T(phenyl)B−) and potassium chloride (KCl) in the membrane. The effect of the salt size on the performance of the SCRE was studied by preparing membranes using compounds with varying alkyl chain lengths. To get reference electrodes, these membranes were drop cast on two different substrates: glassy carbon (GC) disks covered with the conductive polymer (poly(3,4‐ethylenedioxythiophene) doped with chloride (PEDOT‐Cl), or silver disks coated with silver chloride (Ag/AgCl). The potential response of these electrodes was investigated in several potentiometric experiments using a conventional double junction silver chloride electrode as a reference. It was found that electrodes with the tetrabutylammonium tetrabutylborate (TBA‐TBB, single salt) in the membrane were insensitive to changes in electrolyte concentrations but reached stable potentials slowly after changes in the sample electrolyte. The double salt approach, where KCl was also present in the membrane, improved the response time, but these electrodes were more sensitive to concentration changes.
Hypothesis: Bifunctional mitochondrial proteins have centrosomal functions
Authors: Moore Akilah , Golden Andy
Published: June 2009

Mitochondria are dynamic organelles that are involved in a number of diverse processes. Most often the mitochondrion is associated with energy generation, but other important processes occur in this organelle such as fatty acid synthesis and amino acid metabolism. Although mitochondria encode less than 40 genes, all of the other ∼1,000 genes required for their function are nuclear encoded. The protein products from these nuclear encoded genes are subsequently translocated to the mitochondria and utilized in the variety of processes within the organelle. Is it possible then that any of these nuclear encoded proteins could be translocated to other areas of the cell to participate in functions not normally attributed to the mitochondria? There is growing evidence that mitochondrial proteins not only localize to sites outside of the organelle, but also have functionality at these other locales. We suggest that a subset of nuclear encoded mitochondrial proteins are bifunctional and are involved in processes outside of the mitochondria. In this perspective, we will discuss published data demonstrating mitochondrial proteins that influence progression of the cell cycle, alter chromosome morphology, localize to centrosomes, and affect centrosome number in the cell. Overall, the mitochondrion is an interesting organelle that participates in a variety of vital functions. We suggest that these essential functions are not solely due to the ability of the mitochondria to produce high amounts of energy. Throughout this discussion we attempt to demonstrate that a cell cannot live without mitochondria and study this issue from a nonenergetic perspective. Environ. Mol. Mutagen., 2009. Published 2009 Wiley‐Liss, Inc.
Cosmogenic 21Ne analysis of individual detrital grains: Opportunities and limitations
Authors: Codilean Alexandru T. , Bishop Paul , Hoey Trevor B. , Stuart Finlay M. , Fabel Derek
Published: June 2009

We use a numerical model describing cosmogenic nuclide acquisition in sediment moving through the upper Gaub River catchment to evaluate the extent to which aspects of source area geomorphology and geomorphological processes can be inferred from frequency distributions of cosmogenic 21Ne (21Nec) concentrations in individual detrital grains. The numerical model predicts the pathways of sediment grains from their source to the outlet of the catchment and calculates the total 21Nec concentration that each grain acquires along its pathway. The model fully accounts for variations in nuclide production due to changes in latitude, altitude and topographic shielding and allows for spatially variable erosion and sediment transport rates. Model results show that the form of the frequency distribution of 21Nec concentrations in exported sediment is sensitive to the range and spatial distribution of processes operating in the sediment's source areas and that this distribution can be used to infer the range and spatial distribution of erosion rates that characterise the catchment. The results also show that lithology can affect the form of the 21Nec concentration distribution indirectly by exerting control on the spatial pattern of denudation in a catchment. Model results further indicate that the form of the distribution of 21Nec concentrations in the exported sediment can also be affected by the acquisition of 21Nec after detachment from bedrock, in the diffusive (hillslope) and/or advective (fluvial) domains. However, for such post‐detachment nuclide acquisition to be important, this effect needs to at least equal the nuclide acquisition prior to detachment from bedrock. Copyright © 2009 John Wiley and Sons, Ltd.
Amount and controls of the quaternary denudation in the Ardennes massif (western Europe)
Authors: Demoulin A. , Hallot E. , Rixhon G.
Published: June 2009

It is still debated whether the primary control on the middle Pleistocene denudation of the uplifted Ardennes massif (western Europe) is tectonic or climatic. Here, based on geomorphological observations, we calculate the amount of river incision and interfluve denudation in the Meuse basin upstream of Maastricht since 0·7 Ma and we show that the main response to tectonic forcing was incision. This allows us to provide first‐order estimates of the tectonic and climatic contributions to the denudation of the Ardennes. From a dataset of 71 remnants of a terrace level dated ∼0·7 Ma, we first derive a basin‐scale functional relationship linking incision with distances to the regional base level (Lc) and to the source (Ls) in the Ourthe basin (pertaining to the Ardennian part of the Meuse basin). Expressed as I = I0*(1 – a*Lcb/Lsc), I0 being the incision measured at the basin outlet, this relationship calculates that river incision has removed 84 km3 of rock in the Meuse basin upstream of Maastricht since 0·7 Ma. In the same time, 292 km3 were eroded from the interfluves. A comparison of these volumes shows that the tectonically forced river incision accounts for ∼22% of the total post‐0·7 Ma denudation. Furthermore, the mean denudation rate corresponding to our geomorphological estimate of the overall denudation in the Meuse basin since 0·7 Ma amounts to 27 mm/ky, a figure significantly lower than the ∼40 mm/ky mean rate derived from 10Be studies of terrace deposits of the Meuse (Schaller et al., 2004). This suggests that, taken as a basin average, the 10Be‐derived rate is overestimated, probably due to an overrepresentation of the erosion products of the rapidly incising valleys in the alluvial deposits. Copyright © 2009 John Wiley & Sons, Ltd.
The critical role of climate and saprolite weathering in landscape evolution
Authors: Dixon Jean L. , Heimsath Arjun M. , Amundson Ronald
Published: June 2009

Landscapes evolve in response to external forces, such as tectonics and climate, that influence surface processes of erosion and weathering. Internal feedbacks between erosion and weathering also play an integral role in regulating the landscapes response. Our understanding of these internal and external feedbacks is limited to a handful of field‐based studies, only a few of which have explicitly examined saprolite weathering. Here, we report rates of erosion and weathering in saprolite and soil to quantify how climate influences denudation, by focusing on an elevation transect in the western Sierra Nevada Mountains, California. We use an adapted mass balance approach and couple soil‐production rates from the cosmogenic radionuclide (CRN) 10Be with zirconium concentrations in rock, saprolite and soil. Our approach includes deep saprolite weathering and suggests that previous studies may have underestimated denudation rates across similar landscapes. Along the studied climate gradient, chemical weathering rates peak at middle elevations (1200–2000 m), averaging 112·3 ± 9·7 t km–2 y–1 compared to high and low elevation sites (46·8 ± 5·2 t km−2 y−1). Measured weathering rates follow similar patterns with climate as those of predicted silica fluxes, modeled using an Arrhenius temperature relationship and a linear relationship between flux and precipitation. Furthermore, chemical weathering and erosion are tightly correlated across our sites, and physical erosion rates increase with both saprolite weathering rates and intensity. Unexpectedly, saprolite and soil weathering intensities are inversely related, such that more weathered saprolites are overlain by weakly weathered soils. These data quantify exciting links between climate, weathering and erosion, and together suggest that climate controls chemical weathering via temperature and moisture control on chemical reaction rates. Our results also suggest that saprolite weathering reduces bedrock coherence, leading to faster rates of soil transport that, in turn, decrease material residence times in the soil column and limit soil weathering. Copyright © 2009 John Wiley & Sons, Ltd.