bluuebunny/crossref_metadata_2025 huggingface dataset:
La Russie face à la mondialisation : la voie du trans-impérialisme
Authors: Wallander Celeste A. , Allevione Jessica
Published: April 2009

Résumé Grâce à ses ressources énergétiques, la Russie est de retour dans l’économie mondiale dans son voisinage proche, et dans le rapport global des puissances. Elle n’est ni post-impériale, ni néo-impériale. Elle peut plutôt être qualifiée de trans-impériale, en ce sens qu’elle tente de reproduire à l’échelle internationale le système des relations patrons-clientèle qui structurent l’actuel pouvoir à Moscou. Ce trans-impérialisme appelle une réponse coordonnée entre Europe et États-Unis.
La démocratie russe : de la spontanéité à l'improvisation ?
Authors: Salmine Alexeï , Lomidzé Svetlana
Published: April 2009

Résumé De 1991 à 1996, émerge en Russie un régime de « démocratie immature » ou d’« infra-démocratie », fondé sur des institutions nouvelles. Auprès de ces dernières en subsistent d’autres, qui n’ont connu que des changements mineurs, ou se sont recomposées sur des logiques étrangères aux réformes des années 1990. Le régime actuel se caractérise par des institutions de transition, remplissant des espaces sociopolitiques vacants : la vraie lacune de la société russe, c’est l’absence de pouvoir consolidé.
Représenter les intérêts privés pour renforcer la confiance entre la Russie et l'UE
Authors: Bordatchev Timofeï , Rossini Alba
Published: April 2009

Résumé L’élargissement du cercle des acteurs de la coopération Union européenne-Russie, par exemple aux entreprises ou associations, pourrait aider à résoudre nombre de difficultés. Il pourrait produire un rapprochement progressif des comportements sociaux, économiques ou politiques, et aider à remédier au déficit de participation citoyenne dans la gestion des relations entre l’Union et Moscou. Cet élargissement servirait ainsi à la fois le partenariat euro-russe et la construction européenne elle-même.
La Russie, l'OTAN et l'Union européenne : triangle de sécurité européenne ou nouvelle « Entente » ?
Authors: Monaghan Andrew , Rossini Alba
Published: April 2009

Résumé Les relations entre la Russie, l’Organisation du traité de l’Atlantique Nord (OTAN) et l’Union européenne (UE) sont de première importance pour la sécurité européenne. En effet, d’importants progrès ont été accomplis, des mécanismes institutionnels ont été créés, et un certain nombre de coopérations pratiques se sont instaurées. Cependant, cette relation à trois souffre d’un manque persistant de confiance qui est à l’origine d’incompréhensions et de crispations.
Le dialogue énergétique Union européenne-Russie : concurrence contre monopoles
Authors: Milov Vladimir , Allevione Jessica
Published: April 2009

Résumé Les relations énergétiques entre la Russie et l’Union européenne sont au seuil de profonds changements que rend nécessaires l’asymétrie croissante entre un monopole national renforcé sur les approvisionnements, et l’ouverture des marchés en Europe. Les autorités communautaires doivent prendre l’initiative pour un nouveau modèle de relations énergétiques : en dépendent non seulement la sécurité énergétique des Européens, mais encore celle de l’ensemble des marchés énergétiques russes et eurasiens.
Quand le syndicalisme s'éprouve hors du lieu de travail
Authors: Yon Karel
Published: April 2009

Résumé Cet article rend compte d’un aspect du tournant « contestataire » de Force ouvrière (FO) depuis les années 1980 : l’importance nouvelle accordée par les instances confédérales à l’action syndicale interprofessionnelle. Il tente de dépasser le registre de la contradiction entre discours confédéral et pratiques fédérales en prenant en compte la culture organisationnelle qui structure FO. Marquée par le fédéralisme et la distance à la politique, cette culture est saisie à travers l’observation des stages de formation confédéraux. La notion de « style de groupe » est mobilisée comme catégorie d’analyse. L’article montre que l’injonction à « penser interpro » qui se diffuse dans les stages découle de ces contraintes structurelles tout en essayant de les déjouer. Le fédéralisme et la distance à la politique ne doivent pas être interprétés de façon univoque comme des obstacles à la production d’un sentiment d’appartenance confédérale. Ils sont constitutifs du style FO et entretiennent tout à la fois son morcellement interne et la solidité de ses frontières extérieures. L’entreprise confédérale de renforcement de l’identité interprofessionnelle, en valorisant cette singularité, a ainsi moins contribué à consolider la cohérence organisationnelle qu’à développer la scène confédérale comme une niche permettant de nouveaux types d’investissements militants.
« Dans le nettoyage, on ne fait pas du syndicalisme comme chez Renault ! »
Authors: Denis Jean-Michel
Published: April 2009

Résumé Dans le secteur du nettoyage industriel, les obstacles à la syndicalisation sont nombreux et de toute nature. Ils sont liés à la structure du marché du travail interne, aux conditions d’emploi et de travail, au profil social des salariés, etc. Entravent-ils totalement le développement des organisations syndicales et la conduite d’actions revendicatives ? Ou celles-ci réussissent-elles à les surmonter par une approche renouvelée et une offre spécifique ? C’est à ces questions que ce texte cherche à répondre en portant la focale sur les orientations et les pratiques des organisations syndicales implantées dans ce secteur et en s’intéressant à leur aptitude à faire face aux différentes formes de flexibilité auxquelles ont recours les entreprises de la branche.
Daily Mobility of Workers in Slovenia
Authors: Bole David
Published: April 2009

The paper deals with the phenomenon of commuting to work in Slovenia and describes the basic patterns, causes, and consequences of the daily mobility of workers. An important part of the study is establishing the areas of employment attraction of selected urban settlements and their consequences on the phenomena of regional identity, suburbanization, and motorization.
Reduced Permeation of Precipitation Water into Groundwater on Ljubljansko polje
Authors: Smrekar Aleš
Published: April 2009

The permeation of water into groundwater in an urban environment is considerably differ-ent than that in an untransformed landscape. Built-up and open surfaces have very different proportions of impermeable surfaces. Due to urban land use on Ljubljansko polje, the loss of permeating precipitation water is more than 0.5m3/s or 190 mm of precipitation.
An Overview of Custom Array Sequencing
Authors: Kothiyal Prachi , Cox Stephanie , Ebert Jonathan , Aronow Bruce J. , Greinwald John H. , Rehm Heidi L.
Published: April 2009

This unit provides an overview of oligo hybridization–based resequencing and a wide range of considerations for implementing the technology and analyzing the resulting data. The specific technology discussed is the Affymetrix GeneChip CustomSeq Resequencing Array platform. Concepts related to array design, experimental protocols, and base‐calling using existing algorithms are presented. Details that should be evaluated during development of sequence tiling, target amplification, and PCR protocols are addressed. An overview of the Affymetrix GeneChip Sequence Analysis Software (GSEQ) is provided, along with factors that influence base‐calling coverage and accuracy. Also outlined are performance measures that can be used to characterize base‐calling with resequencing arrays, as well as factors known to affect their performance. Limitations associated with detection of insertions and deletions (indels) are discussed, with empirical data from our experiments used to outline possible approaches to indel detection. Critical topics in the design, implementation, and analysis of targeted sequencing arrays not previously discussed in detail are highlighted. Curr. Protoc. Hum. Genet. 61:7.17.1‐7.17.11. © 2009 by John Wiley & Sons, Inc.
Methylation‐Specific PCR
Authors: Coffee Bradford
Published: April 2009

DNA methylation is a dynamic covalent modification of DNA that is found in transcriptionally repressed regions of the genome. In concert with other epigenetic modifications, such as the repressive histone H3 modifications of lysine 9 and lysine 27 methylation, DNA methylation acts to repress gene expression through the formation of condensed chromatin structures. Thus, DNA methylation is a marker for gene repression. Methylation‐specific PCR (MSP) is a rapid and inexpensive method that can be used to determine the methylation status of DNA. MSP can be used to assess CpG methylation at imprinted genes and on the inactive X chromosome. In addition, MSP can be used to investigate the aberrant DNA methylation that occurs in diseases such as fragile X syndrome and in many types of cancers. MSP is rapid, inexpensive, and relatively simple to perform and provides a powerful tool to investigate these epigenetic processes. Curr. Protoc. Hum. Genet. 61:10.6.1‐10.6.14. © 2009 by John Wiley & Sons, Inc.
Kinetics of adsorption of 2‐CEES and HD on impregnated silica nanoparticles under static conditions
Authors: Saxena Amit , Srivastava Avanish Kumar , Singh Beer
Published: April 2009

Silica nanoparticles of high surface area (887.3 m2/g) were synthesized using aerogel route and, thereafter, impregnated with those reactive chemicals, which have already been proven to be effective against sulfur mustard (HD). Thus, developed adsorbents were tested for their potential by conducting studies on kinetics of adsorption of 2‐chloroethylethyl sulfide (2‐CEES) and HD under static conditions. Kinetics of adsorption was studied using linear driving force model and Fickian diffusion model. The kinetic parameters such as equilibration constant, equilibration capacity, diffusional exponent, and adsorbate‐adsorbent interaction constant were also determined. Trichloroisocyanuric acid impregnated silica nanoparticles (10% w/w) showed the maximum uptake of 2‐CEES (1824 mg/g) and HD (1208 mg/g). Values of diffusional exponent indicated the mechanisms to be Fickian and anomalous. Chemical interaction seemed to be another mechanism involved in the toxicant uptake rate. Hydrolysis, dehydrochlorination, and oxidation reactions were found to be the route of degradation of toxicants. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Hydrodynamics and mass transfer of gas–liquid flow in a falling film microreactor
Authors: Zhang Haocui , Chen Guangwen , Yue Jun , Yuan Quan
Published: April 2009

In this article, flow pattern of liquid film and flooding phenomena of a falling film microreactor (FFMR) were investigated using high‐speed CCD camera. Three flow regimes were identified as “corner rivulet flow,” “falling film flow with dry patches,” and “complete falling film flow” when liquid flow rate increased gradually. Besides liquid film flow in microchannels, a flooding presented as the flow of liquid along the side wall of gas chamber in FFMR was found at high liquid flow rate. Moreover, the flooding could be initiated at lower flow rate with the reduction of the depth of the gas chamber. CO2 absorption was then investigated under the complete falling flow regime in FFMR, where the effects of liquid viscosity and surface tension on mass transfer were demonstrated. The experimental results indicate that kL is in the range of 5.83 to 13.4 × 10−5 m s−1 and an empirical correlation was proposed to predict kL in FFMR. © 2009 American Institute of Chemical Engineers AIChE J, 2009
High resolution SNP based microarray mapping of mosaic supernumerary marker chromosomes 13 and 17: Delineating novel loci for apraxia
Authors: Kogan Jillene M. , Miller Erin , Ware Stephanie M.
Published: April 2009

High resolution comparative genomic hybridization is emerging as a powerful tool for delineating chromosomal rearrangements such as duplications, deletions, and unbalanced translocations, but it has not yet been broadly applied for structural aberrations such as supernumerary marker chromosomes (SMCs). In this report, we present the clinical and molecular analysis of a patient with de novo mosaic SMC (17) and SMC (13). High resolution single nucleotide polymorphism (SNP) based microarray mapping successfully identified the parent of origin for the SMCs and allowed delineation of the breakpoints which include a 5.1 Mb duplication from 17p11.2 to 17q11.2 as well as duplication of chromosome 13 that includes 2.2 Mb from 13q11 to 13q12.11. Interestingly, the patient has markedly severe oral and verbal apraxia, a characteristic feature of patients with 17p11.2 duplication syndrome (Potocki–Lupski syndrome, PTLS). Fine mapping indicates that the patient's duplication overlaps with a subset of PTLS patients, but not with PTLS patients harboring the common microduplication. FISH analysis confirms that the patient lacks duplication of RAI1, a dosage sensitive gene within the common microduplication interval. Taken together, these results demonstrate the utility of SNP microarray based methodology for mapping disease‐causing genes, including those within SMCs, and provide the opportunity to identify novel candidate genes for verbal apraxia. © 2009 Wiley‐Liss, Inc.
aCGH detects partial tetrasomy of 12p in blood from Pallister–Killian syndrome cases without invasive skin biopsy
Authors: Theisen Aaron , Rosenfeld Jill A. , Farrell Sandra A. , Harris Catharine J. , Wetzel Heather H. , Torchia Beth A. , Bejjani Bassem A. , Ballif Blake C. , Shaffer Lisa G.
Published: April 2009

Pallister–Killian syndrome (PKS) is a genetic disorder characterized by mental retardation, seizures, streaks of hypo‐ or hyperpigmentation and dysmorphic features. PKS is associated with tissue‐limited mosaic partial tetrasomy of 12p, usually caused by an isochromosome 12p. The mosaicism is usually detected in cultured skin fibroblasts or amniotic cells and rarely in phytohemagluttinin‐stimulated lymphocytes, which suggests stimulation of T‐lymphocytes may distort the percentage of abnormal cells. We recently reported on the identification by microarray‐based comparative genomic hybridization (aCGH) of a previously unsuspected case of partial tetrasomy of 12p caused by an isochromosome 12p. Here we report on seven additional individuals with partial tetrasomy of 12p characterized by our laboratory. All individuals were referred for mental retardation/developmental delay and/or dysmorphic features. In each case, aCGH using genomic DNA extracted from whole peripheral blood detected copy‐number gain for all clones for the short arm of chromosome 12. In all but one case, FISH on metaphases from cultured lymphocytes did not detect the copy‐number gain; in the remaining case, metaphase FISH on cultured lymphocytes showed an isochromosome in 10% of cells. However, interphase FISH using probes to 12p on peripheral blood smears showed additional hybridization signals in 18–70% of cells. Microarray and FISH analysis on cultured skin biopsies from four individuals confirmed the presence of an isochromosome 12p. Our results demonstrate the usefulness of aCGH with genomic DNA from whole peripheral blood to detect chromosome abnormalities that are not present in stimulated blood cultures and would otherwise require invasive skin biopsies for identification. © 2009 Wiley‐Liss, Inc.
Unusual Interlocking and Interpenetration Lead to Highly Porous and Robust Metal–Organic Frameworks
Authors: Ma Liqing , Lin Wenbin
Published: April 2009

Schluss mit Atmen: MOFs mit komplexen und großen organischen Brückenliganden neigen beim Entfernen des Lösungsmittels zu Gerüstverzerrungen („Atmen“). Ein Versteifen von MOFs mit langen Tetracarboxylat‐Brückenliganden durch ein ungewöhnliches Verzahnen und Durchdringen liefert hoch poröse und robuste Hybridmaterialien.

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Chiral Recognition of Hybrid Metal Oxide by Peptides
Authors: Micoine Kévin , Hasenknopf Bernold , Thorimbert Serge , Lacôte Emmanuel , Malacria Max
Published: April 2009

In Grammmengen gelingt die Enantiomerentrennung eines geringfügig – durch ein Fremdatom im Nanogerüst – chiralen Polyoxometallats (POM) durch Umsetzung mit kleinen Peptiden. Das funktionalisierbare Acylpolyoxowolframat (TBA)6[α1‐P2W17O61{SnCH2CH2C(O)}] (siehe Bild) lässt sich durch kinetische Racematspaltung trennen. Dieser Ansatz ebnet den Weg für die Anwendung chiraler POMs in der asymmetrischen Katalyse oder als bioaktive Substanzen.

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Physical Biology.From Atoms to Medicine. Edited by Ahmed Zewail.
Authors: Chergui Majed
Published: April 2009

Imperial College Press, 2008. 584 pp., hardcover, $ 78.00.—ISBN 978‐1848162006

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Mechanisms of ultrasound foam interactions
Authors: Winterburn J. B. , Martin P. J.
Published: April 2009

An experimental investigation into the effects of two frequencies of low‐power ultrasound on detergent (Teepol) stabilised air‐water foams is presented. Foam was subjected to ultrasound at 28 and 40 kHz with a power‐to‐foam volume ratio of approximately 3 W l−1 with particular consideration being given to the acoustic impedance discontinuity between air and water. The foam height, liquid drainage and collapse behaviour were compared to experiments conducted without ultrasound. In the case of 40 kHz ultrasound, an increased liquid drainage rate was observed and a pronounced increase and subsequent peak in mean liquid hold‐up, which occurred at 4 min, was observed. These results appear to be independent of the initial liquid hold‐up of the foam. Liquid drainage and mean liquid hold‐up results were related to foam collapse mechanisms of homogeneous rupture (HR) and rupture front breakage (FR), concluding that rupture front breakage dominates the collapse of foam under the influence of 40 kHz ultrasound. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Electromuscular incapacitation results from stimulation of spinal reflexes
Authors: Despa Florin , Basati Suki , Zhang Zhen‐Du , D'Andrea John , Reilly J Patrick , Bodnar Elena N. , Lee Raphael C.
Published: April 2009

Electronic stun devices (ESD) often used in law enforcement, military action or self defense can induce total body uncoordinated muscular activity, also known as electromuscular incapacitation (EMI). During EMI the subject is unable to perform purposeful or coordinated movements. The mechanism of EMI induction has not been reported, but has been generally thought to be direct muscle and nerve excitation from the fields generated by ESDs. To determine the neuromuscular mechanisms linking ESD to induction of EMI, we investigated EMI responses using an anesthetized pig model. We found that EMI responses to ESD application can best be simulated by simultaneous stimulation of motor and sensory peripheral nerves. We also found that application of local anesthetics limited the response of ESD to local muscle stimulation and abolished the total body EMI response. Stimulation of the pure sensory peripheral nerves or nerves that are primarily motor nerves induced muscle responses that are consistent with well defined spinal reflexes. These findings suggest that the mechanism of ESD‐induced EMI is mediated by excitation of multiple simultaneous spinal reflexes. Although direct motor‐neuron stimulation in the region of ESD contact may significantly add to motor reactions from ESD stimulation, multiple spinal reflexes appear to be a major, and probably the dominant mechanism in observed motor response. Bioelectromagnetics 30:411–421, 2009. © 2009 Wiley‐Liss, Inc.
Effective diffusivities and mass fluxes in fungal biopellets
Authors: Hille A. , Neu T.R. , Hempel D.C. , Horn H.
Published: April 2009

Mass transport within biological aggregates is a key process that can determine overall turnover rates in submerged cultivations. A parameter commonly used for its description is the effective diffusion coefficient D eff, which is highly dependent on biomass density and structure. Different approaches have been used to estimate or measure D eff, yet the data still shows broad scattering. This study provides experimental data on effective diffusivities of oxygen within fungal pellets. A correlation is found with the hyphal gradient (dh/dr), which is a morphological parameter describing the structure of the pellet periphery. Furthermore, the dependency of D eff on fluid dynamic conditions at the pellet is investigated. The comparison of the results with data from literature clearly demonstrates the influence of the experimental methodology applied for determination of D eff. Moreover, it is shown that while diffusion limitation of whole pellets is mainly a function of size, the influence of advection in the outer zone of pellets that is supplied with oxygen is actually rather high. Thus, it is concluded that the effective diffusion coefficient might not be sufficient for the description of mass transport within the pellet periphery for a broad range of realistic fluid dynamic conditions during cultivation. Nevertheless, although actual mass transport rates inside pellets are unknown, mass fluxes can be calculated on the basis of spatially resolved data of oxygen and biomass distribution within the pellet. Biotechnol. Bioeng. 2009;103: 1202–1213. © 2009 Wiley Periodicals, Inc.
Impact of lactic acid on cell proliferation and free radical‐induced cell death in monolayer cultures of neural precursor cells
Authors: Lampe Kyle J. , Namba Rachael M. , Silverman Tyler R. , Bjugstad Kimberly B. , Mahoney Melissa J.
Published: April 2009

Biomaterials prepared from polyesters of lactic acid and glycolic acid, or a mixture of the two, degrade in the presence of water into the naturally occurring metabolites, lactic acid and glycolic acid. While the lactic acid degradation product that is released from biomaterials is well tolerated by the body, lactic acid can influence the metabolic function of cells; it can serve as an energy substrate for cells, and has been shown to have antioxidant properties. Neural precursor cells, a cell population of considerable interest as a source of cells for neural tissue regeneration strategies, generate a high amount of reactive oxygen species, and when associated with a degradable biomaterial, may be impacted by released lactic acid. In this work, the effect of lactic acid on a neural cell population containing proliferative neural precursor cells was examined in monolayer culture. Lactic acid was found to scavenge exogenously added free radicals produced in the presence of either hydrogen peroxide or a photoinitiator (I2959) commonly utilized in the preparation of photopolymerizable biomaterials. In addition to its effect on exogenously added free radicals, lactic acid reduced intracellular redox state, increased the proliferation of the cell population, and modified the cell composition. The findings of this study provide insight into the role that lactic acid plays naturally on developing neural cells and are also of interest to biomaterials scientists that are focused on the development of degradable lactic‐acid‐based polymers for cell culture devices. The effect of lactic acid on other cell populations may differ and should be characterized to best understand how cells function in degradable cell culture devices. Biotechnol. Bioeng. 2009;103: 1214–1223. © 2009 Wiley Periodicals, Inc.
Regenerative medicine bioprocessing: Concentration and behavior of adherent cell suspensions and pastes
Authors: Zoro B.J.H. , Owen S. , Drake R.A.L. , Mason C. , Hoare M.
Published: April 2009

Regenerative medicines based on human cells demand their harvesting, culture, and processing. Manufacturing processes are likely to include cell concentration and subsequent controlled dosing of concentrates, for example, to the patient or tissue construct. The integrity and functionality of the cells must be maintained during these processing stages. In this study the performance of two different cell concentration protocols (involving centrifugation and resuspension) are compared and consideration given to possible causes of cell loss. Further studies examine cell size and rheological behavior of anchorage‐dependent mammalian cell suspensions, and the effect of capillary flow stress (0.5–15 Pa, laminar flow regime) on cell number and membrane integrity as quantified by flow cytometry. The cell concentration protocols achieved maximum cell volume fraction of around 0.3 and the improved protocol exhibited intact cell yield of 80 ± 13%, demonstrating proof‐of principle for achieving tissue‐like cell concentrations by a process of centrifugation and orbital shaking. Volume mean cell diameter (cell diameter at the mean cell volume) for the rat aortic smooth muscle cells (CRL‐1444) used in this study was 22.4 µm. Concentrated cell suspension rheology approximated to power law behavior and exhibited similar trends to reports for plant and yeast cells. Capillary transfer at 2–15 Pa (wall shear stress) did not significantly affect cell number or membrane integrity while losses observed at low shear (0.5, 1.0 Pa) were probably due to surface attachment of cells in the apparatus. Biotechnol. Bioeng. 2009;103: 1236–1247. © 2009 Wiley Periodicals, Inc.
Hans Hass – ein Leben für die Unterwasserwelt
Authors: Scholz Joachim , Wöss Emmy
Published: April 2009

Im Jahre 2009 feiern wir in den Lebenswissenschaften neben dem Darwin‐Jahr auch weitere Jubiläen. Der 90. Geburtstag von Professor Hans Hass (*1919) ist Anlass dieses Artikels. Hans Hass wird oft als “Tauchpionier” bezeichnet, eine dem Jubilar nicht vollständig gerecht werdende Bezeichnung. Sein Lebenswerk umfasst mehr als 100 Filme und 30 Bücher.
Sichtbarmachung von Nukleinsäurefragmenten durch Agarosegelelektrophorese
Authors: Schrödel Andrea
Published: April 2009

Mit Hilfe eines aus roten Meeresalgen gewonnenen Polysaccharids (Agarose) mit stark gelierenden Eigenschaften werden in der Wissenschaft Gele hergestellt, mit deren Hilfe man Nukleinsäurefragmente (DNA und RNA) unterschiedlicher Größe auftrennen kann, nachdem sie beispielsweise per PCR amplifiziert wurden. Man spricht von der Methode der Agarosegelelektrophorese.
Krankheiten erben und erwerben
Authors: Kronberg Inge
Published: April 2009

Die Entschlüsselung des menschlichen Genoms weckte große Hoffnungen, nun auch die genetischen Anteile von Krankheiten wie Diabetes, Autismus, Schizophrenie oder Fettleibigkeit herauszufinden. Genomanalysen könnten dann Erkrankungsrisiken abschätzen und langfristig ließen sich personalisierte Behandlungsmethoden entwickeln. Bisher haben vergleichende Genomstudien allerdings viele neue Fragen zum Verständnis der Erblichkeit aufgeworfen.
Die Struktur der DNA – Modell‐Projekt II
Authors: Quadbeck‐Seeger H.‐J.
Published: April 2009

Wie die DNA in etwa aussieht, kennt praktisch jeder von Abbildungen. Allerdings zeigen erst dreidimensionale Modelle die eindrucksvolle Schönheit und Vollkommenheit des Moleküls. Leider sind solche Modelle teuer. In zwei Artikeln (Biol. unserer Zeit, 2008, 38, 150 sowie Chem. unserer Zeit 2008, 42, 293) wurde ein Modell vorgeschlagen, das sich sehr kostengünstig herstellen lässt. Nun wächst die Modell‐Familie: Für Unterrichtszwecke lassen sich nach neuem Konzept auch deutlich größere, ebenfalls kostengünstige Modelle bauen.
Retention data from reverse‐phase high‐performance thin‐layer chromatography in characterization of some bis‐salicylic acid derivatives
Authors: Djaković‐Sekulić Tatjana , Perišić‐Janjić Nada , Djurendi Evgenija
Published: April 2009

The chromatographic behaviour of salicylic acid derivatives was investigated using reversed‐phase high performance thin‐layer chromatography (RP HPTLC) with methanol–water and dioxane–water binary mixtures as mobile phase in order to establish relationships between chromatographic data and selected physico‐chemical parameters that are related to ADME (absorption, distribution, metabolism and elimination). Some of the investigated compounds were screened for antioxidant activity. Examination of chromatographic behaviour revealed a linear correlation between RM values and the volume fraction of mobile phase modifier. Obtained RM0 values were correlated with lipophilicity, solubility, human intestinal absorption, plasma‐protein binding, and blood–brain barrier data. The comparison among chromatographic data obtained by two mobile phase was performed with a statistical technique, principle component analysis. Copyright © 2009 John Wiley & Sons, Ltd.
Immobilization of a thermostable α‐amylase by covalent binding to an alginate matrix increases high temperature usability
Authors: Tee Boon L. , Kaletunç Gönül
Published: April 2009

Thermostable α‐amylase was covalently bound to calcium alginate matrix to be used for starch hydrolysis at liquefaction temperature of 95°C. 1‐ethyl‐3‐(3‐dimethylamino‐propyl) carbodiimide hydrochloride (EDAC) was used as crosslinker. EDAC reacts with the carboxylate groups on the calcium alginate matrix and the amine groups of the enzyme. Ethylenediamine tetraacetic acid (EDTA) treatment was applied to increase the number of available carboxylate groups on the calcium alginate matrix for EDAC binding. After the immobilization was completed, the beads were treated with 0.1 M calcium chloride solution to reinstate the bead mechanical strength. Enzyme loading efficiency, activity, and reusability of the immobilized α‐amylase were investigated. Covalently bound thermostable α‐amylase to calcium alginate produced a total of 53 g of starch degradation/mg of bound protein after seven consecutive starch hydrolysis cycles of 10 min each at 95°C in a stirred batch reactor. The free and covalently bound α‐amylase had maximum activity at pH 5.5 and 6.0, respectively. The Michaelis‐Menten constant (Km) of the immobilized enzyme (0.98 mg/mL) was 2.5 times greater than that of the free enzyme (0.40 mg/mL). The maximum reaction rate (Vmax) of immobilized and free enzyme were determined to be 10.4‐mg starch degraded/mL min mg bound protein and 25.7‐mg starch degraded/mL min mg protein, respectively. The high cumulative activity and seven successive reuses obtained at liquefaction temperature make the covalently bound thermostable α‐amylase to calcium alginate matrix, a promising candidate for use in industrial starch hydrolysis process. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Synthesis and Biological Evaluation of Nitric Oxide‐Donating Thalidomide Analogues as Anticancer Agents
Authors: Wang Tao , Zhang Yi‐Hua , Kong Xiang‐Wen , Lai Yi‐Sheng , Ji Hui , Chen Yan‐Ping , Peng Si‐Xun
Published: April 2009

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In search of more potent anticancer agents, 15 nitric oxide (NO)‐donating thalidomide analogues, 6a, 6b, 8a–8e, and 13a–13h, were designed and synthesized. Cytotoxicity of these compounds was evaluated in vitro against three human tumor cell lines (HepG2, A549, and PC‐3). The results indicated that 13a–13d exhibited notable anticancer activities comparable to or stronger than that of 5‐fluorouracil (5‐FU). Structure–activity relationships were also discussed, based on the experimental data obtained. Generally, the cytotoxic activity of target compounds is closely related to the type of NO donors, and the length of the spacers connecting to NO donors also appears important for the bioactivities.
Molluscicidal Sesquiterpene Lactones from Species of the Tribe Vernonieae (Compositae)
Authors: Borkosky Susana , de León Susana Ponce , Juárez Gabriela , Sierra Manuel González , Bardón Alicia
Published: April 2009

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Schistosomiasis is caused by parasitic flatworms of the genus Schistosoma, and some snails, particularly of the genus Biomphalaria (Planorbidae), are directly implicated in the transmission of the disease. Continuing with our investigations of bioactive plant constituents, we evaluated and report in the present article, the molluscicidal effects of 16 sesquiterpene lactones, as well as the commercial reagents tetrahydrofuran, furfural, and furfuryl alcohol, on an adult population of B. peregrina. The natural sesquiterpene lactones tested are characteristic constituents of species of the tribe Vernonieae, family Asteraceae. Compounds 1–3 and 7 came from a Bolivian collection of Vernonanthura pinguis, compounds 4 and 5 from an Argentine collection of Cyrtocymura cincta var. cincta, 6 was obtained from a Bolivian collection of Eirmocephala megaphylla, 8–14 from an Argentine collection of Centratherum punctatum ssp. punctatum, and compounds 15 and 16 were obtained by chemical derivatization from 5 and 14, respectively. Ten of the sesquiterpene lactones displayed moderate molluscicidal activity (LD50<100 μg/ml). Commercial reagents were inactive.
Non‐Nucleoside HIV‐1 Reverse Transcriptase Inhibitors. Part 13
Authors: Xiong Yuan‐Zhen , Chen Fen‐Er , Balzarini Jan , De Clercq Erik , Pannecouque Christophe
Published: April 2009

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A series of diaryltriazine derivatives modified at C(2) of the triazine ring with a fluorinated phenyl group has been synthesized and tested for the ability to inhibit HIV‐1 replication. Most of these F‐containing compounds showed low‐to‐moderate anti‐HIV activity in MT‐4 cells.
Phytotoxic Aromatic Constituents of Oxalis pes‐caprae
Authors: DellaGreca Marina , Previtera Lucio , Purcaro Raffaella , Zarrelli Armando
Published: April 2009

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A cinnamic acid ester, two dihydrocinnamic acid esters, a noroxyneolignan, a dibenzyl ether derivative, along with common aromatic compounds and flavonoids were isolated from the extracts of fresh leaves and twigs of Oxalis pes‐caprae. The structures of these aromatic compounds were elucidated on the basis of spectroscopic analyses, especially 2D‐NMR techniques. Their effects on the germination and growth of Lactuca sativa L. as standard target species have been studied at concentrations ranging from 10−4 to 10−7 M. The activities of some compounds were higher than that of pendimethalin, a commercial pre‐emergence herbicide.
Nonenzymatic, Self‐Elimination Degradation Mechanism of Glutathione
Authors: Deshmukh Manjeet , Kutscher Hilliard , Stein Stanley , Sinko Patrick
Published: April 2009

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In the present in vitro studies, evidence is provided showing that glutathione (GSH) can undergo spontaneous, nonenzymatic auto‐degradation. The initial cleavage of the Glu‐Cys bond involves nucleophilic attack of the N‐terminal amino group of GSH at the γ‐carbonyl side chain, followed by an unusual cleavage of the Cys‐Gly amide bond that is complete within 3–5 weeks in the physiological pH range. These observations may be useful for the development of novel biodegradable polymers and releasable prodrugs for sustained and targeted drug delivery applications.
Fabrication of Carbohydrate Surfaces by Using Nonderivatised Oligosaccharides, and their Application to Measuring the Assembly of Sugar–Protein Complexes
Authors: Popplewell Jonathan F. , Swann Marcus J. , Ahmed Yassir , Turnbull Jerry E. , Fernig David G.
Published: April 2009

This way up. Dual polarisation interferometry was used to design and characterise a surface on which the orientation and density of immobilised carbohydrates was suitable for studying their interactions with proteins. Lactoferrin was shown to adopt two orientations: “end‐on” or “side‐on”, while for FGF‐2 a single monolayer of protein was observed. The new surface can be used to elucidate the binding of proteins to carbohydrates and the geometry of the complexes, a frequently controversial area.

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Surface‐based tools, such as microarrays and optical biosensors, are being increasingly applied to the analysis of carbohydrate–protein interactions. A key to these developments is the presentation of the carbohydrate to the protein target. Dual polarisation interferometry (DPI) is a surface‐based technique that permits the real‐time measurement of the changes in thickness, refractive index and mass of adsorbates 100 nm thick or less on the surface of a functionalised waveguide. DPI has been used to design and characterise a surface on which the orientation and density of the immobilised carbohydrates is suitable for studying their interactions with proteins and where nonspecific binding is reduced to less than 5 % of total binding. A thiol‐functionalised surface was derivatised with a heterobifunctional crosslinker to yield a hydrazide surface. This was treated with oligosaccharides, derived from keratan sulfate (KS) chondroitin sulfate (CS) and heparin, that possess a reducing end. To block the unreacted hydrazide groups, the surface was treated with an aldehyde‐functionalised PEG. The heparin DP‐10 surfaces were then used to determine the performance of the immobilised DP‐10 with respect to binding of two well‐characterised proteins, lactoferrin (Lf) and fibroblast growth factor‐2. The results show that Lf could adopt two different orientations, at high protein loadings the protein layer thickness corresponded to an “end‐on” orientation of Lf, whilst rinsing with buffer saw the Lf molecules adopt a “side‐on” configuration. In the case of FGF‐2, a single monolayer of protein bound to DP‐10 was observed. These results demonstrate that the new surface can be used to resolve key questions relating to the binding of proteins to carbohydrates, including, when used in DPI, the resolution of the geometry of complexes, an area that is frequently controversial.
New Approach for Local Structure Analysis of the Tyrosine Domain in Proteins by Using a Site‐Specific and Polarity‐Sensitive Fluorescent Probe
Authors: Chen Suming , Li Xiaohua , Ma Huimin
Published: April 2009

Designer label: A newly developed polarity‐sensitive fluorescent probe (DBHA) was combined with a tyrosine‐specific labelling method that uses transition metal catalysis, and was successfully used in local structural analysis of the Tyr108 domain in Cu/Zn superoxide dismutase (SOD; see scheme). The strategy presented here provides a new approach for studying the local polarity and conformation changes of this tyrosine domain in SOD under acid or heat denaturation conditions.

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The design and synthesis of a novel long‐wavelength polarity‐sensitive fluorescence probe, 6‐[9‐(diethylamino)‐5‐oxo‐5 H‐benzo[α]phenoxazin‐2‐yloxy]hex‐2‐enyl acetate, for the selective modification of tyrosine residues with the goal of providing local information on tyrosine domains in proteins, is reported. This probe comprises a polarity‐sensitive Nile red fluorophore and an active π‐allyl group that can form π‐allylpalladium complexes and react selectively with tyrosine residues. The probe has the following features: 1) it has a long‐wavelength emission of >550 nm, thanks to which interference from short‐wavelength fluorescence from common biological matrixes can be avoided; 2) the maximum emission wavelength is sensitive only to polarity and not to pH or temperature; this allows the accurate determination of local polarity; and 3) it is a neutral, uncharged molecule, and does not disturb the overall charge of the labelled protein. With this probe the polarity and conformation changes of the Tyr108 domain in native and in acid‐ and heat‐denatured bovine Cu/Zn superoxide dismutase were detected for the first time. It was found that the polarity of the Tyr108 domain hardly alters on acid denaturation between pH 4 and 9. However, heat denaturation caused the Tyr108 domain to be more hydrophobic, and was accompanied by an irreversible aggregation of the protein. In addition, the probe‐binding experiments revealed that the surface of the protein becomes more hydrophobic after thermal denaturation; this can be ascribed to the formation of the more hydrophobic aggregates. This strategy might provide a general approach for studying the local environment changes of tyrosine domains in proteins under acid or heat denaturation conditions.
Insights into Sequence–Activity Relationships amongst Baeyer–Villiger Monooxygenases as Revealed by the Intragenomic Complement of Enzymes from Rhodococcus jostii RHA1
Authors: Szolkowy Claudia , Eltis Lindsay D. , Bruce Neil C. , Grogan Gideon
Published: April 2009

The Rhodococcus jostii RHA1 genome encodes a number of enzymes that can be exploited as biocatalysts. Study of the substrate spectrum and enantioselectivity of Baeyer–Villiger monooxygenases from R. jostii allowed the identification of short amino acid sequences specific to groups displaying certain catalytic characteristics. The gel illustrates the substrate acceptance spectra and selectivities of the different proteins.

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Microbial genome sequences are providing a wealth of information on new enzymes that have considerable potential as biocatalysts. The recently sequenced genome of Rhodococcus jostii RHA1, for example, has revealed an impressive array of catabolic enzymes, including many putative Baeyer–Villiger monooxygenases (BVMOs). We have cloned 23 target BVMO sequences from the genome of R. jostii RHA1 and heterologously expressed 13 of these as soluble proteins to unearth new substrate specificities and selectivities. Whole‐cell biocatalysts expressing the genes were screened against seven different test substrates. Each of these catalysts displayed activity toward at least three ketones. We observed a remarkable diversity of both regio‐ and enantioselectivity among the BVMOs from R. jostii RHA1 for the transformation of two chiral substrates, with some enzymes displaying high enantioselectivity for the isomers of 2‐methylcyclopentanone. With the notable exception of the product of gene ro03437, named MO14, the biocatalysts' sequences correlated well with their respective activities and selectivities. This correlation allowed the identification of sequence motifs specific to subgroups of the BVMOs from R. jostii and other organisms. Overall, the data improve predictive models of BVMO activity from sequence and suggest new avenues to pursue in engineering these enzymes.
Synthesis and Structure of α/δ‐Hybrid Peptides—Access to Novel Helix Patterns in Foldamers
Authors: Sharma Gangavaram V. M. , Babu Bommagani Shoban , Ramakrishna Kallaganti V. S. , Nagendar Pendem , Kunwar Ajit C. , Schramm Peter , Baldauf Carsten , Hofmann Hans‐Jörg
Published: April 2009

Origami peptides: A novel class of foldamers consisting of α/δ‐hybrid peptides has been investigated theoretically and experimentally by exploiting the rigidity of the side chain of a new δ‐amino acid prepared from D‐glucose and D‐xylose with a furanose side chain (see figure).

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Stimulated by an overview on all periodic folding patterns of α/δ‐hybrid peptides with 1:1 alternating backbone provided by ab initio molecular orbital theory, the first representatives of this foldamer class were synthesized connecting novel C‐linked carbo‐δ‐amino acid constituents and L‐Ala. In agreement with theoretical predictions, extensive NMR spectroscopic analyses confirm the formation of new motifs of 13/11‐mixed helical patterns in these peptides supported by the rigidity of the D‐xylose side chain in the selected δ‐amino acid constituents. Relationships between possible helix types in α/δ‐hybrid peptides and their counterparts in other 1:1 hybrid peptide classes and native α‐peptides are discussed; these indicate the high potential of these foldamers to mimic native peptide secondary structures. The design of α/δ‐hybrid peptides provides an opportunity to expand the domain of foldamers and allows the introduction of desired functionalities through the α‐amino acid constituents.
Control of the Supramolecular Excimer Formation of Thioflavin T within a Cucurbit[8]uril Host: A Fluorescence On/Off Mechanism
Authors: Mohanty Jyotirmayee , Dutta Choudhury Sharmistha , Upadhyaya Hari P. , Bhasikuttan Achikanath C. , Pal Haridas
Published: April 2009

On or off? A new excimer band at λ=570 nm was visualized during the noncovalent host–guest interaction between thioflavin T (ThT) and cucurbit[8]uril (CB8). Controlled dissociation of this assembly in the presence of Ca2+ was demonstrated as an on/off fluorescence switch (see picture).

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Consecutive Three‐Component Synthesis of Ynones by Decarbonylative Sonogashira Coupling
Authors: Merkul Eugen , Oeser Thomas , Müller Thomas J. J.
Published: April 2009

Mild conditions! Decarbonylative carbonylation by consecutive glyoxylation of indoles, 7‐aza‐indoles, or pyrroles with oxalyl chloride and subsequent Pd/Cu‐catalyzed decarbonylative alkynylation with terminal alkynes furnishes alkynones under very mild conditions. 4‐(Indol‐3‐yl)‐, 4‐(7‐aza‐indol‐3‐yl)‐, and 4‐(pyrrol‐2‐yl)‐2‐amino pyrimidines can be readily obtained in a concise two‐step synthesis starting from N‐substituted indoles, 7‐aza‐indoles, or pyrroles (see scheme).

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Conformationally Complex π‐Conjugated Molecular and Polymeric Materials: New Challenges for Organic Synthesis
Authors: Guthrie Daryl A. , Tovar John D.
Published: April 2009

No protection? A unique, albeit fairly specialized, example of what promises to be a useful retrosynthetic consideration for those designing complex π‐molecular systems, namely, using conformation as a protecting group to shield a given reactive site in lieu of protecting‐group manipulation, is described (see scheme).

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Conformational influences profoundly impact the performance of organic electronic materials and the reactivity of organic molecules. We recently found that the expected former consideration was uniquely accompanied by the latter. This report describes a surprisingly regioselective bromination that suggests the general use of conformation as a protecting group during complex molecule synthesis.
The Electrochemistry of Carbon Nanotubes: Fundamentals and Applications
Authors: Pumera Martin
Published: April 2009

Electrocatalytic or not? Carbon nanotubes (CNTs; see figure) are at the forefront of electrochemical research, but care should be taken when describing the electrochemistry, which is often caused by defects or impurities. A discussion on this aspect of their chemistry as well as important applications of CNTs for sensing and energy storage are presented.

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Carbon nanotubes (CNTs) are in the forefront of electrochemical research. It has become clear that an understanding of the fundamental reasons for the electrochemical activity of CNTs is essential for further progress in the field. This review provides a critical discussion of the fundamental reasons behind the electrochemical and “electrocatalytic” activity of CNTs as well as on important applications of CNTs for sensing, biosensing, and energy storage systems.
ChemInform Abstract: Transport Properties and Lithium Insertion Study in the p‐Type Semi‐Conductors AgCuO2 and AgCu0.5Mn0.5O2.
Authors: Sauvage F. , Munoz‐Rojas D. , Poeppelmeier K. R. , Casan‐Pastor N.
Published: April 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: Phase Diagram Investigations of the Ni—Sn—Bi System.
Authors: Vassilev G. P. , Lilova K. I. , Gachon J.‐C.
Published: April 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: Facile Sonochemical Synthesis and Photoluminescent Properties of Lanthanide Orthophosphate Nanoparticles.
Authors: Yu Cuicui , Yu Min , Li Chunxia , Liu Xiaoming , Yang Jun , Yang Piaoping , Lin Jun
Published: April 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: Solvothermal Crystal Growth of CuSbQ2 (Q: S, Se) and the Correlation Between Macroscopic Morphology and Microscopic Structure.
Authors: Zhou Jian , Bian Guo‐Qing , Zhu Qin‐Yu , Zhang Yong , Li Chun‐Ying , Dai Jie
Published: April 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.