bluuebunny/crossref_metadata_2025 huggingface dataset:
Stabilisation of Methylene Radicals by Cob(II)alamin in Coenzyme B12 Dependent Mutases
Authors: Buckel Wolfgang , Kratky Christoph , Golding Bernard T.
Published: November 2005

Coenzyme B12 initiates radical chemistry in two types of enzymatic reactions, the irreversible eliminases (e.g., diol dehydratases) and the reversible mutases (e.g., methylmalonyl‐CoA mutase). Whereas eliminases that use radical generators other than coenzyme B12 are known, no alternative coenzyme B12 independent mutases have been detected for substrates in which a methyl group is reversibly converted to a methylene radical. We predict that such mutases do not exist. However, coenzyme B12 independent pathways have been detected that circumvent the need for glutamate, β‐lysine or methylmalonyl‐CoA mutases by proceeding via different intermediates. In humans the methylcitrate cycle, which is ostensibly an alternative to the coenzyme B12 dependent methylmalonyl‐CoA pathway for propionate oxidation, is not used because it would interfere with the Krebs cycle and thereby compromise the high‐energy requirement of the nervous system. In the diol dehydratases the 5′‐deoxyadenosyl radical generated by homolysis of the carbon–cobalt bond of coenzyme B12 moves about 10 Å away from the cobalt atom in cob(II)alamin. The substrate and product radicals are generated at a similar distance from cob(II)alamin, which acts solely as spectator of the catalysis. In glutamate and methylmalonyl‐CoA mutases the 5′‐deoxyadenosyl radical remains within 3–4 Å of the cobalt atom, with the substrate and product radicals approximately 3 Å further away. It is suggested that cob(II)alamin acts as a conductor by stabilising both the 5′‐deoxyadenosyl radical and the product‐related methylene radicals.
Linear HThThH: A Candidate for a Th—Th Triple Bond
Authors: Straka Michal , Pyykkoe Pekka
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis, Structure, and Electronic and Physical Properties of the Two SrZrS3 Modifications.
Authors: Lee Chi‐Shen , Kleinke Katja M. , Kleinke Holger
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Crystal Field Interaction in LnFe2Si2 (Ln: Er and Tm)
Authors: Harker S. J. , Stewart G. A. , Gubbens P. C. M. , de Vroege C. F.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Magnetic Investigations on Six Compounds with the General Formula (Ca,Y)Ba(Co,Fe,Al,Zn)4O7 and the Structures of YBaCoFeZn2O7 and YBaCo2FeZnO7.
Authors: Valldor Martin
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
[Me4N][Cu2(NCS)3] — A Compound Having a Framework Structure with Large Channels.
Authors: Dilshad R. , Boller H. , Klepp K. O.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Enantioselective Phenyl Transfer to Aldehydes Using 1,1′‐Bi‐2‐Naphthol‐3,3′‐dicarboxamide as Chiral Auxiliary.
Authors: Ito Katsuji , Tomita Yuki , Katsuki Tsutomu
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Tunable Dendritic Ligands of Chiral 1,2‐Diamine and Their Application in Asymmetric Transfer Hydrogenation.
Authors: Liu Weiguo , Cui Xin , Cun Linfeng , Zhu Jin , Deng Jingen
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Intermolecular Rhodium‐Catalyzed [2 + 2 +2] Carbocyclization Reactions of 1,6‐Enynes with Symmetrical and Unsymmetrical Alkynes.
Authors: Evans P. Andrew , Sawyer James R. , Lai Kwong Wah , Huffman John C.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Asymmetric Carroll Rearrangement of Allyl α‐Acetamido‐β‐ketocarboxylates Catalyzed by a Chiral Palladium Complex.
Authors: Kuwano Ryoichi , Ishida Naoki , Murakami Masahiro
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Regiocontrolled Carbometalation Reactions of Ynamides.
Authors: Chechik‐Lankin Helena , Livshin Shulamit , Marek Ilan
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
A Novel Rearrangement of Arylvinylidenecyclopropanes to Naphthalene Derivatives Catalyzed by Lewis Acids or Broensted Acids.
Authors: Xu Guang‐Cai , Ma Ming , Liu Le‐Ping , Shi Min
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Facile Cyclization of Amidyl Radicals Generated from N‐Acyltriazenes.
Authors: Lu Hongjian , Li Chaozhong
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
New Formation of 4,5,6,7‐Tetrahydroisoindoles.
Authors: Hou Duen‐Ren , Hsieh Yih‐Dar , Hsieh Yi‐Wei
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Reactions of N‐ and C‐Alkenylanilines. Part 7. Synthesis of Indole Heterocycles from Products of Reaction Between N‐Mesyl‐2‐(1‐alken‐1‐yl)anilines and Halogens.
Authors: Gataullin R. R. , Sotnikov A. M. , Spirikhin L. V. , Abdrakhmanov I. B.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Cross‐Coupling Reactions of Substituted 5‐Triflyloxyindoles.
Authors: England Dylan B. , Kerr Michael A.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Facile Deallylation Protocols for the Preparation of N‐Unsubstituted Triazoles and Tetrazoles.
Authors: Kamijo Shin , Huo Zhibao , Jin Tienan , Kanazawa Chikashi , Yamamoto Yoshinori
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of 1,4‐Dihydropyrano[2,3‐c]pyrazole Derivatives.
Authors: Vasyun'kina T. N. , Bykova L. M. , Plotkin V. N. , Ramsh S. M.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
A Novel One‐Step Synthesis of 2‐Substituted 6‐Azaindoles from 3‐Amino‐4‐picoline and Carboxylic Esters.
Authors: Song Jinhua J. , Tan Zhulin , Gallou Fabrice , Xu Jinghua , Yee Nathan K. , Senanayake Chris H.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Circumdatin H, a New Inhibitor of Mitochondrial NADH Oxidase, from Aspergillus ochraceus
Authors: Lopez‐Gresa M. Pilar , Gonzalez M. Carmen , Primo Jaime , Moya Pilar , Romero Vanessa , Estornell Ernesto
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Six New Indole Alkaloids from Gelsemium sempervirens Ait. f.
Authors: Kogure Noriyuki , Nishiya Chika , Kitajima Mariko , Takayama Hiromitsu
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
High‐Pressure Neutron Diffraction Study of Superhydrated Natrolite.
Authors: Colligan Marek , Lee Yongjae , Vogt Thomas , Celestian Aaron J. , Parise John B. , Marshall William G. , Hriljac Joseph A.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
One‐Step Direct Synthesis of a Ti‐Doped Sodium Alanate Hydrogen Storage Material.
Authors: Bellosta von Colbe Jose M. , Felderhoff Michael , Bogdanovic Borislav , Schueth Ferdi , Weidenthaler Claudia
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and in vitro Study of Novel 7‐O‐Acyl Derivatives of Oroxylin A as Antibacterial Agents.
Authors: Suresh Babu K. , Hari Babu T. , Srinivas P. V. , Sastry B. S. , Hara Kishore K. , Murty U. S. N. , Madhusudana Rao J.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Soft Functional Polynuclear Coordination Compounds Containing Pyrimidine Bridges
Authors: Navarro Jorge A. R. , Barea Elisa , Galindo Miguel A. , Salas Juan M. , Romero M. Angustias , Quiros Miguel , Masciocchi Norberto , Galli Simona , Sironi Angelo , Lippert Bernhard
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Chances and Limits of the Coordination Chemistry with Bis(benzene‐1,2‐ Dithiolato) Ligands
Authors: Seidel Wolfram W. , Hahn F. Ekkehardt
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Transition Metal‐Catalyzed Reactions Using Alkynes as Precursors of Carbene and Vinylidene Complexes
Authors: Miki Koji , Uemura Sakae , Ohe Kouichi
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Alkyl Metals
Authors: Moynihan H. A.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Alkylphosphorus Compounds
Authors: Kielbasinski P. , Zurawinski R. , Balczewski P. , Mikolajczyk M.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Heterocyclic Synthesis and Therapeutic Chemistry: A Successful Marriage
Authors: Guillaumet G.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Crystal Comets: Dewetting During Emulsion Droplet Crystallization
Authors: Spicer Patrick T. , Hartel Richard W.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Organic Host—Guest Structures in the Solid State
Authors: Nangia Ashwini
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Application of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry to Oligosaccharides
Authors: Park Youmie , Lebrilla Carlito B.
Published: November 2005

For Abstract see ChemInform Abstract in Full Text.
Effects of intracerebroventricular losartan on angiotensin II‐mediated pressor responses andc‐fosexpression in near‐term ovine fetus
Authors: Shi Lijun , Mao Caiping , Thornton Simon N. , Sun Wanping , Wu Jiawei , Yao Jiaming , Xu Zhice
Published: November 2005

The renin‐angiotensin system plays an important role in cardiovascular control. Intracerebroventricular (i.c.v.) angiotensin (ANG) II causes a reliable pressor response in the fetus at 90% gestation. To determine the roles of brain AT1and AT2receptors in this response, the effects of the central AT1and AT2receptor antagonists losartan and PD123319 were investigated in chronically prepared near‐term ovine fetuses. Losartan at 0.5 mg/kg (i.c.v.) abolished central ANG II‐induced pressor responses. High‐dose losartan (5 mg/kg, i.c.v.) showed a potentiation of the pressor response to i.c.v. ANG II, accompanied by bradycardia. Associated with the pressor responses,c‐fosexpression in the cardiovascular controlling areas was significantly different between the low and high doses of losartan. These areas included the subfornical organ, median preoptic nucleus, organum vasculosum of the lamina terminalis, and paraventricular nuclei in the forebrain, and the tractus solitarius nuclei, lateral parabrachial nuclei in the hindbrain. Low‐dose losartan markedly reduced c‐fos in these areas after i.c.v. ANG II, while the high‐dose losartan together with ANG II elicited a much stronger FOS‐immunoreactivity in these areas than that induced by i.c.v. ANG II alone. This is a novel finding, thatc‐fosexpression in the brain can be both activated and inhibited under the same condition. Central ANG II‐induced fetal pressor responses were not altered by PD123319 (0.8 mg/kg). These results indicate that i.c.v. losartan at a high and a low dose has strikingly different effects on central ANG II‐induced pressor responses in fetuses at late gestation, and that the AT1mechanism plays an important role in fetal cardiovascular regulation. J. Comp. Neurol. 493:571–579, 2005. © 2005 Wiley‐Liss, Inc.
Amino‐phosphanes in RhI‐Catalyzed Hydroformylation: Hemilabile Behavior of P,N Ligands under High CO Pressure and Catalytic Properties
Authors: Andrieu Jacques , Camus Jean‐Michel , Richard Philippe , Poli Rinaldo , Gonsalvi Luca , Vizza Francesco , Peruzzini Maurizio
Published: November 2005

The catalytic properties of rhodium complexes containing the α‐, β‐, or γ‐amino‐phosphane ligands Ph2PCH2NEt2 (α‐P,N‐1), Ph2PCH(Ar)NHPh [α‐P,N‐2; Ar = η6(o‐C6H4Cl)Cr(CO)3], Ph2PCH2NPh2 (α‐P,N‐3), Ph2PCH2CH(Ph)NHPh (β‐P,N), Ph2PCH2(o‐C6H4–NMe2) (γ‐P,N‐1), Ph2PCH(o‐C6H4–CH2NHPh) (γ‐P,N‐2), and the α,β‐diamino‐phosphane ligand Et2NCH2P(Ph)CH2CH(Ph)NHPh (α,β‐N,P,N), in styrene hydroformylation have been examined. The results show that the activity increases when the number of backbone carbon atoms linking P and N decreases from 3 to 1. IR and 31P HPNMR studies in solution show that all P,N ligands adopt exclusively a κ1‐P coordination mode in rhodium chloride carbonyl complexes under high CO pressure. In the solid state a κ1‐P‐α‐amino‐phosphane coordination has been ascertained by X‐ray methods in trans‐[RhCl(CO)(γ‐P,N‐1)2]. In contrast, an equilibrium between the κ2‐P,N and κ1‐P‐coordination modes has been observed as a function of the CO pressure for the complex containing the β‐P,N ligand. The basicity of the dangling amino group also plays an important role on the catalytic activity and a mechanism involving the nitrogen function in the catalytic cycle is proposed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
An Original Supramolecular Helicate from a Bipyridine–Bipyrazine Ligand Strand and NiII by Self‐Assembly
Authors: Mathieu Julien , Fraisse Bernard , Lacour Daniel , Ghermani Noureddine , Montaigne François , Marsura Alain
Published: November 2005

A new discrete supramolecular pseudo‐helicate has been obtained from a saturated heterotopic methylbipyrazyl–methylbipyridyl ligand strand and NiCl2. The X‐ray structure of the dinuclear complex shows the 2‐oxapropylene bridge oxygen atoms are engaged in coordination to the octahedral metal centre and a selective ligand inter‐strand orientation is promoted in the complex. The crystal packing shows a perfect regular linear arrangement of the asymmetric units giving a packing of interacting molecules having well‐defined rectangular and polygonal open channels. Although a paramagnetic behaviour is observed above 10 K, below this temperature a significant deviation of this behaviour suggests the presence of an NiII–NiII magnetic coupling. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Electrocatalytic Oxidation of Dopamine and Ascorbic Acid on Carbon Paste Electrode Modified with Nanosized Cobalt Phthalocyanine Particles: Simultaneous Determination in the Presence of CTAB
Authors: Yang Gong‐Jun , Xu Jing‐Juan , Wang Kun , Chen Hong‐Yuan
Published: November 2005

Metallophthalocyanine (MPc) and its derivatives are well known as electrocatalysts to catalyze oxidation or reduction of some species, such as cysteine, nitric oxide. Their nanosized particles may display the potential optics, electronic, catalytic and structural properties. In this paper, carbon paste electrodes modified with nanosized cobalt phthalocyanine particles (denoted as Nano‐CoPc‐CPE) are fabricated. The electrocatalytic oxidation of dopamine (DA) and ascorbic acid (AA) on the Nano‐CoPc‐CPE was investigated by means of cyclic voltammetry. Nano‐CoPc particles perform good electrocatalytic activity to DA and AA. The anodic peak potentials of DA and AA were separated with good sensitivity in the presence of cetyltrimethylammonium bromide (CTAB). The DA and AA can be simultaneously determined by using differential pulse voltammetry. On optimal conditions, the good linear response to DA and AA was observed in the range of 3.0×10−6–1.0×10−4 M and 5.0×10−6–3.0×10−4 M with the correlation coefficient of 0.9983 and 0.9978, respectively. Moreover, 100‐fold AA did not interfere in the determination of DA. This method has been used to simultaneously determine DA and AA concentration in mixed drug samples with satisfactory results.
A new single grating spectrograph for ultraviolet Raman scattering studies
Authors: Hecht Lutz , Clarkson John , Smith Brian J. E. , Springett Roger
Published: November 2005

A state‐of‐the‐art single grating spectrograph for Raman scattering studies within the deep ultraviolet (DUV) region of the electromagnetic spectrum is discussed. It is based on a high throughput DUV version of a single‐stage monochromator originally designed for use in the visible spectral region. Its key components are two identical, newly designed calcium fluoride camera lenses each consisting of five different individual optical elements. The first of these lenses collimates the Raman scattered DUV radiation entering the spectrometer through its entrance slit. The second lens focuses the collimated beam of dispersed Raman scattered DUV radiation emerging from a high‐resolution reflection grating onto a charge coupled device (CCD) detector with enhanced DUV sensitivity. A novel high transmission edge filter is used as a blocking device for a sufficient rejection of the Rayleigh line generating a relatively sharp transmittance cutoff at a Stokes Raman wavenumber shift of about ∼450 cm−1 employing 257 nm DUV excitation. Overall, this new spectrograph enables rapid collection of Stokes DUV Raman scattered photons at f/2 wide apertures with sufficiently large signal‐to‐noise ratios (SNRs) in relatively short acquisition times and with an effective spectral resolution of approximately ∼6 cm−1. Backscattered Raman spectra of the following chemicals are presented as typical results illustrating the excellent performance characteristics of this new DUV spectrograph for a variety of experimental conditions within different scattering scenarios and for a relatively wide range of commonly used sample preparation techniques: neat cyclohexane, laboratory air, polycrystalline D‐glucose, single crystal L‐alanine and a dilute aqueous solution of 2′‐deoxyadenosine. Copyright © 2005 John Wiley & Sons, Ltd.
Intra-cavity polarizing element for Nd:YAG laser
Authors: Ahmed M A , Moser T , Pigeon F , Parriaux O , Graf Th
Published: November 2005

A monolithic intra cavity polarizing element which
consist on the association of a sub-wavelength resonant waveguide
grating and a slightly modified standard multi-dielectric mirror
showed a high purity polarized beam out of a Nd:YAG laser.
Negative refraction makes photonic crystal as super-concave-mirror
Authors: Liu Y-Z
Published: November 2005

Point imaging in a triangular two-dimensional photonic
crystal slab due to the negative refraction is studied
theoretically. The finite-difference time-domain scheme is used to
investigate the field patterns of a TM-polarized point source
placed in the vicinity of the PC slab. With proper surface
termination of photonic crystal (PC) slab, we find one image
occurs in the same side as the point source by negative refraction
and reflection at the two sides of the PC slab which makes the PC
slab act as super-concave-mirror.
Standardised load‐time histories – a contribution to durability issues under spectrum loading
Authors: Heuler P. , Bruder T. , Klätschke H.
Published: November 2005

It is well established that the fatigue performance of materials and structures may be very sensitive to the specifics of the loading encountered. Beside constant amplitude testing, therefore, tests with realistic load sequences are often required in order to assess any susceptibility to the specifics of variable amplitude loading and to demonstrate the in‐service integrity for given materials and structures. For these purposes standardised load‐time histories (SLH’s) have been developed for 30 years since it has been recognised that the use of SLH’s a series of advantages – both for studies of a more generic nature and practical applications. Starting with Gassner’s block programme test, some features of standardised load‐time histories available at present and their relevance for fatigue behaviour of materials and structures are reviewed.
Fatigue of welded hybrid‐joints
Authors: Schliebner R. , Vormwald M.
Published: November 2005

Only for steels up to grade S690QL the well‐known fact is confirmed that the fatigue strength of welded joints is independent of the material. For higher strength steels a remarkable reduction of the fatigue strength is found.

Some advice is given for designers in which situations the one or the other of the various approaches for the assessment of the fatigue strength of welds could be applied. In complex, real situations even the highly sophisticated effective notch stress approach might loose its applicability. A new alternative approach is proposed for these situations. It is based on stresses in real notches and an example is presented for the familiar case of a start‐stop position.
Modelling and fatigue life assessment of complex structures
Authors: Marquis G. , Samuelsson J.
Published: November 2005

This paper presents some of the motivations and main conclusions from a series of joint Nordic research initiatives in which an integrated research approach to the development of future generations of advanced fabricated structures have been employed. The integrated research approach includes coordinated efforts in several key technologies: high‐speed welding processes, high strength materials, cost‐effective NDE, post‐weld treatments and FE‐based design assessment tools. Traditionally, fatigue assessment methods for welded structures have been developed based on small‐scale test specimens and verification studies for large structures are rarely published. Applications on complex structures have led to several new assessment concepts and areas for future work. A modified structural stress method that proposes a multi‐linear stress distribution through the plate thickness is introduced. Also, a crack growth assessment method in which the constraint equations of a sub‐model are linked to the global model is presented. Both these new methods are promising for complex structures. The crucial role of boundary conditions for complex structures is highlighted as is the future challenge of understanding and making use of the residual stress state for welded structures.
Entwicklung eines praxisgeeigneten Prüfverfahrens zur Bewertung des Wasserstoffgefährdungspotenzials von Salzsäurebeizen und zum Vergleich der Wirksamkeit von Inhibitoren
Authors: Schröder‐Rentrop I. , Landgrebe R. , Berger C. , Hasselmann U.
Published: November 2005

Bei der im Rahmen einer Feuerverzinkung notwendigen Beizbehandlung, die zumeist in Salzsäure vorgenommen wird, kann es zur Entwicklung von atomarem Wasserstoff an der Stahloberfläche kommen. Ziel der nachfolgend dargestellten Untersuchungen war, den Prozess der Feuerverzinkung von hochfesten Schrauben, die aufgrund der geforderten hohen Zugfestigkeiten in einem sprödbruchanfälligen Werkstoffzustand vorliegen können, insbesondere unter Aspekten der Qualitätssicherung beherrschbarer zu machen und möglichst zu verbessern.

Es wurde ein praxistaugliches Versuchsverfahren zur Prozessüberwachung inhibierter Beizen entwickelt. Bei dem Verfahren handelt es sich um einen Verspannversuch, der an Wellensicherungsringen (WSR) nach DIN 471 in einer hierfür entwickelten Aufweitvorrichtung durchgeführt wird. Die Indikationssicherheit des Versuchsverfahrens wurde durch den Vergleich der Ergebnisse des Verspannversuches mit WSR mit den Ergebnissen aus anderen Untersuchungsverfahren, die mit den gleichen Salzsäurebeizen erzielt wurden, belegt. Die „Wiederholpräzision”︁ des Verspannversuches mit Wellensicherungsringen wurde durch übereinstimmende Ergebnisse, die mit WSR aus unterschiedlichen Fertigungslosen und Wärmebehandlungslosen erzielt wurden, belegt. Die Verspannversuche mit WSR eignen sich als praxistaugliches Prüfverfahren und zeichnen sich darüber hinaus durch einen geringen zeitlichen und materiellen Prüfaufwand, eine einfache Handhabung sowie einen robusten und fehlertoleranten Versuchsaufbau aus.

Das im Rahmen des Projektes entwickelte, aus verschiedenen Versuchsführungen bestehende Untersuchungsprogramm, ermöglicht darüber hinaus die umfassende Bewertung geeigneter Inhibitoren für die Beizvorbehandlung hochfester vergüteter Verbindungselemente.
Zur Plausibilität der Methode der Zugdreiecke
Authors: Mattheck C. , Bethge K.
Published: November 2005

Die im Forschungszentrum Karlsruhe entwickelte Formoptimierung von Bauteilen nach den Gestaltprinzipien der Natur [1] hat sich in den letzten 15 Jahren weit verbreitet und in der Industrie, insbesondere im Automobilbau bewährt. Die Grenzen der CAO‐Methode (Computer Aided Optimization) sind auch eher wirtschaftlicher Natur. Hier wird die Plausibilität einer neuen, rein graphischen Methode aufgezeigt, die ohne FEM und Optimierungssoftware auskommt.
Low temperature‐induced systems failure in Escherichia coli: Insights from rescue by cold‐adapted chaperones
Authors: Strocchi Massimo , Ferrer Manuel , Timmis Kenneth N. , Golyshin Peter N.
Published: November 2005

The growth of Escherichia coli cells is impaired at temperatures below 21°C and stops at 7.5°C; however, growth of a transgenic strain producing the cold‐adapted chaperones Cpn60 and Cpn10 from the psychrophilic bacterium Oleispira antarctica is good at low temperatures. The E. coli cpn+ transgene offers a novel opportunity for examining the essential protein for cell viability at low temperatures. By screening a large‐scale protein map (proteome) of cells of K‐12 and its Cpn+ transgene incubated at 4°C, we identified 22 housekeeping proteins involved in systems failure of E. coli when confronted with low temperature. Through co‐immunoprecipitation of Cpn60, Northern blot, and in vitro refolding, we systematically identified that protein–chaperone interactions are key determinants of their protein functions at low temperatures. Furthermore, chromosomal gene deletion experiments suggest that the mechanism of cold‐induced systems failure in E. coli is cold‐induced inactivation of the GroELS chaperonins and the resulting failure to refold cold‐inactivated Dps, ClpB, DnaK and RpsB proteins. These findings: (1) indicate the potential importance of chaperones in cold sensitivity, cold adaptation and cold tolerance in cellular systems, and (2) suggest the identity of a few key cold‐sensitive chaperone‐interacting proteins that get inactivated and ultimately cause systems failure in E. coli cells at low temperatures.
Proteomic investigation of the molecular pathophysiology of dysferlinopathy
Authors: De Palma Sara , Morandi Lucia , Mariani Elena , Begum Shajna , Cerretelli Paolo , Wait Robin , Gelfi Cecilia
Published: November 2005

Mutations in dysferlin gene cause several types of muscular dystrophy in humans, including the limb‐girdle muscular dystrophy type 2B and the distal muscular dystrophy of Miyoshi. The dysferlin gene product is a membrane‐associated protein belonging to the ferlins family of proteins. The function of the dysferlin protein and the cause of deterioration and regression of muscle fibres in its absence, are incompletely known. A functional clue may be the presence of six hydrophilic domains, C2, that bind calcium and mediate the interaction of proteins with cellular membranes. Dysferlin seems to be involved in the membrane fusion or repair. Molecular diagnosis of dysferlinopathies is now possible and the types of gene alterations that have been characterized so far include missense mutations, deletions and insertions.
Depressive symptoms after lung cancer surgery: their relation to coping style and social support
Authors: Walker Mark S. , Zona Denise M. , Fisher Edwin B.
Published: November 2005

Lung cancer patients may experience greater emotional distress than patients with other cancers. Studies have shown social support to predict adjustment in other cancers, but findings among lung cancer patients have been equivocal. Coping style has been shown to predict distress among lung cancer patients, but has not been examined in the context of social support. We examined coping style and social support as predictors of depressive symptoms one week after surgery among 119 patients with non‐small cell lung cancer. The Beck Depression Inventory was the primary outcome measure. Predictors included age, ECOG performance status, stage of disease, and measures of adaptive coping, less adaptive coping, Directive instrumental social support and Nondirective instrumental social support. Results indicated that 29% of lung cancer patients had scores above a standard cutoff for clinically significant depression. Results also showed that depressive symptoms were directly related to use of less adaptive coping methods and Directive instrumental social support, inversely related to age and use of adaptive coping methods, and unrelated to nondirective social support, stage of disease and performance status. Results extend previous findings by showing that adaptive coping methods are related to severity of distress, and that the benefits of social support may depend on the characteristics of that support. Copyright © 2005 John Wiley & Sons, Ltd.
A method for localizing ligand binding pockets in protein structures
Authors: Glaser Fabian , Morris Richard J. , Najmanovich Rafael J. , Laskowski Roman A. , Thornton Janet M.
Published: November 2005

The accurate identification of ligand binding sites in protein structures can be valuable in determining protein function. Once the binding site is known, it becomes easier to perform in silico and experimental procedures that may allow the ligand type and the protein function to be determined. For example, binding pocket shape analysis relies heavily on the correct localization of the ligand binding site. We have developed SURFNET‐ConSurf, a modular, two‐stage method for identifying the location and shape of potential ligand binding pockets in protein structures. In the first stage, the SURFNET program identifies clefts in the protein surface that are potential binding sites. In the second stage, these clefts are trimmed in size by cutting away regions distant from highly conserved residues, as defined by the ConSurf‐HSSP database. The largest clefts that remain tend to be those where ligands bind. To test the approach, we analyzed a nonredundant set of 244 protein structures from the PDB and found that SURFNET‐ConSurf identifies a ligand binding pocket in 75% of them. The trimming procedure reduces the original cleft volumes by 30% on average, while still encompassing an average 87% of the ligand volume. From the analysis of the results we conclude that for those cases in which the ligands are found in large, highly conserved clefts, the combined SURFNET‐ConSurf method gives pockets that are a better match to the ligand shape and location. We also show that this approach works better for enzymes than for nonenzyme proteins. Proteins 2006. © 2005 Wiley‐Liss, Inc.
Kinetic parameters of crystallization in glassy Se100–xSbx alloys
Authors: Mehta N. , Zulfequar M. , Kumar A.
Published: November 2005

Differential scanning calorimetry (DSC) has been performed at different heating rates under non‐isothermal conditions to study the crystallization kinetics of glassy Se100–xSbx (2 ≤ x ≤ 10) alloys. The crystallization kinetics have been studied using four different methods of analysis of the non‐isothermal DSC data and various kinetic parameters (the activation energy of crystallization, order parameter, rate constant and frequency factor) have been determined. The difference Tc – Tg (indicator of thermal stability) has been determined from the DSC thermograms for each sample. The rate constant K (indicator of the rate of amorphous to crystalline phase transformation) has been evaluated using the method of Augis and Bennett. The increasing sequence of the rate constant in the glasses studied is opposite to that of Tc – Tg. This indicates that chalcogenide glasses having a higher rate of crystallization have less thermal stability. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Relationship between QRS duration, left ventricular volumes and prevalence of nonviability in patients with coronary artery disease and severe left ventricular dysfunction
Authors: De Winter Olivier , Van de Veire Nico , Van Heuverswijn Frederic , Van Pottelberge Geert , Gillebert Thierry C. , De Sutter Johan
Published: November 2005

Background:

Patients with coronary artery disease (CAD), a QRS duration ≥120 ms and left ventricular ejection fraction (LVEF) ≤30% are potential candidates for cardiac resynchronization therapy (CRT). Our aim was to investigate the relationship between QRS duration, left ventricular volumes and prevalence of nonviable tissue in this patient population.

Methods:

We studied 132 patients (118 men, age 68±5 years) with CAD and LVEF ≤30% (mean LVEF 24±6%). LV volumes and myocardial viability were determined by gated myocardial perfusion imaging.

Results:

A QRS duration ≥120 ms was present in 91 patients (69%). Although there were no differences in LVEF, patients with longer QRS durations had significant larger end‐diastolic and end‐systolic volumes (p<0.01). Substantial nonviable tissue in the inferior or lateral wall was present in 29% of patients with a QRS duration ≥120 ms versus 7% of those with a QRS duration <<120 ms (p<0.01).

Conclusions:

An increased QRS duration is associated with more advanced remodeling in patients with CAD and poor LV function. Almost one third of these patients with a prolonged QRS duration have no viable tissue in the inferolateral wall, an area that is usually stimulated with CRT.
Accuracy of B‐type natriuretic peptide levels in the diagnosis of left ventricular dysfunction and heart failure: A systematic review
Authors: Latour‐Pérez Jaime , Coves‐Orts Francisco Javier , Abad‐Terrado Carmen , Abraira Víctor , Zamora Javier
Published: November 2005

Objectives:

To evaluate the accuracy of B‐type natriuretic peptide levels (BNP) in the diagnosis of heart failure and left ventricular dysfunction.

Data sources:

Electronic search in Medline, Embase, Cochrane Library and Medion database, and hand search of reference lists.

Review methods:

We have included published studies on the accuracy of BNP which had both sufficient information to construct the 2×2 diagnostic cross table and an appropriate spectrum of patients.

Results:

Fifty five studies (16,730 patients) were analyzed. The main determinants of diagnostic accuracy were the reference standard analyzed (clinical heart failure versus left ventricular dysfunction), and the methodological quality of the study. BNP levels were highly accurate for the diagnosis of clinical heart failure (diagnostic OR=41; 95% CI 23–74). The negative likelihood ratios were homogeneous, and useful for excluding the existence of heart failure (pooled negative likelihood ratio=0.11; 95% CI 0.08–0.16). The studies focused on the identification of left ventricular dysfunction were heterogeneous, with indications of publication bias, and showed less overall diagnostic accuracy than studies focused on heart failure.

Conclusions:

BNP levels are useful for ruling out heart failure. The accuracy of BNP for identifying patients with systolic dysfunction is more limited.
Pain induced by low‐grade stress in patients with fibromyalgia and chronic shoulder/neck pain, relation to surface electromyography
Authors: Nilsen K.B. , Westgaard R.H. , Stovner L.J. , Helde G. , Rø M. , Sand T.H.
Published: November 2005

The mechanisms of pain causation in fibromyalgia (FMS) and chronic shoulder/neck pain (SNP) are still debated. We wanted to compare muscle activity and pain development during and after low‐grade mental stress in FMS and SNP patients. Twenty‐three women with FMS, 29 women with chronic SNP and 35 healthy women performed a stressful task lasting 60 min followed by a 30 min recovery period. We recorded surface electromyography over the trapezius, neck, temporalis and frontalis muscles. Subjects reported their pain at the corresponding locations together with the development of fatigue and perceived tension. Significant differences between FMS and SNP groups were not observed either for muscular or subjective responses. SNP patients and controls responded with more pain in the trapezius and neck regions than in the forehead, in contrast to FMS patients who had a more generalized pain response. Development of pain, tension and fatigue was not related to muscle activity for any group. We conclude that FMS and SNP patients have similar pain and electromyographic responses. The results suggest that similar pathophysiological mechanisms are involved although the responses are more generalised in FMS than in SNP patients. Muscular activity did not explain the pain which developed during the stressful task for either group. Pain lasted longer during recovery in both FMS and SNP patients compared to healthy controls, possibly a result of disease‐related sensitisation in pain pathways.
The binding of mycolic acids to galectin‐3: A novel interaction between a host soluble lectin and trafficking mycobacterial lipids?
Authors: Barboni Erminia , Coade Stephen , Fiori Anna
Published: November 2005

Understanding the molecular mechanism of host‐pathogen interactions is the basis for drug design and vaccine development. The fine composition of mycolic acids (MA), the major constituents of Mycobacterium tuberculosis (Mtb) cell envelope, as well as other cell wall‐associated lipids, contribute to determine the virulence of a given strain. However, endogenous receptors for mycolic acids on susceptible cells exposed to mycobacterial infections have not been fully identified. Here, we show that galectin‐3, a multifunctional β‐galactoside binding lectin present mainly in the cytoplasm of inflammatory cells and also present on the cell surface, can recognize mycobacterial mycolic acids. MA can inhibit the lectin self‐association but not its carbohydrate‐binding abilities and can selectively interfere in the interaction of the lectin with its receptors on temperature‐sensitive dendritic cell line, suggesting that galectin‐3 could be involved in the recognition of trafficking mycolic acids and participate in their interaction with host cells.
Multiple incorporation of non‐natural amino acids into a single protein using tRNAs with non‐standard structures
Authors: Ohtsuki Takashi , Manabe Taishi , Sisido Masahiko
Published: November 2005

The ability to introduce non‐natural amino acids into proteins opens up new vistas for the study of protein structure and function. This approach requires suppressor tRNAs that deliver the non‐natural amino acid to a ribosome associated with an mRNA containing an expanded codon. The suppressor tRNAs must be absolutely protected from aminoacylation by any of the aminoacyl‐tRNA synthetases in the protein synthesizing system, or a natural amino acid will be incorporated instead of the non‐natural amino acid. Here, we found that some tRNAs with non‐standard structures could work as efficient four‐base suppressors fulfilling the above orthogonal conditions. Using these tRNAs, we successfully demonstrated incorporation of three different non‐natural amino acids into a single protein.
Structural basis for the specificity of basic winged bean lectin for the Tn‐antigen: A crystallographic, thermodynamic and modelling study
Authors: Kulkarni Kiran A. , Sinha Sharmistha , Katiyar Samiksha , Surolia Avadhesha , Vijayan Mamannamana , Suguna Kaza
Published: November 2005

The crystal structure of winged bean basic agglutinin in complex with GalNAc‐α‐O‐Ser (Tn‐antigen) has been elucidated at 2.35 Å resolution in order to characterize the mode of binding of Tn‐antigen with the lectin. The Gal moiety occupies the primary binding site and makes interactions similar to those found in other Gal/GalNAc specific legume lectins. The nitrogen and oxygen atoms of the acetamido group of the sugar make two hydrogen bonds with the protein atoms whereas its methyl group is stabilized by hydrophobic interactions. A water bridge formed between the terminal oxygen atoms of the serine residue of the Tn‐antigen and the side chain oxygen atom of Asn128 of the lectin increase the affinity of the lectin for Tn‐antigen compared to that for GalNAc. A comparison with the available structures reveals that while the interactions of the glyconic part of the antigen are conserved, the mode of stabilization of the serine residue differs and depends on the nature of the protein residues in its vicinity. The structure provides a qualitative explanation for the thermodynamic parameters of the complexation of the lectin with Tn‐antigen. Modeling studies indicate the possibility of an additional hydrogen bond with the lectin when the antigen is part of a glycoprotein.
The Impact of a Novel Computerized CBT CD Rom (Overcoming Depression) Offered to Patients Referred to Clinical Psychology
Authors: Whitfield Graeme , Hinshelwood Robert , Pashely Adele , Campsie Linda , Williams Chris
Published: November 2005

A new CBT based CD Rom (Williams, Taylor, Aubin, Harkin and Cottrell, 2002) was introduced as a way of offering a clinical psychology waiting-list initiative for patients with depression and depression with anxiety. This study evaluated the impact of this computerized cognitive behavioural therapy (CCBT) on consecutive referrals. Six hourly sessions of the interactive computer programme were offered to clients on the waiting list, to be completed by them with some support from a self-help support nurse. Seventy-eight consecutive referrals were offered an appointment for CCBT; 20 (26%) attended at least one session of CCBT and 14 (70% of starters) completed all six hour-long sessions. Beck Depression Inventory scores (BDI-II) fell from a mean of 28.15 (SD 11.41) to 20.00 (SD 10.41) (p = .000) over the 6-week intervention period using an intention to treat analysis. The discussion asks why only a quarter of patients on this psychology waiting list chose to use a CBT CD-Rom, but also notes that those who did use it had clinically and statistically significant reductions in their reported symptoms of depression.
Variability of Mg/Ca and Sr/Ca between and within the planktonic foraminifers Globigerina bulloides and Globorotalia truncatulinoides
Authors: Anand Pallavi , Elderfield Henry
Published: November 2005

The variability in Mg/Ca and Sr/Ca within individual tests and chambers of tests, and samples consisting of differing numbers of individuals, was determined for Globigerina bulloides and Globorotalia truncatulinoides in a North Atlantic core top sample (52.918°N 16.917°W′). The variability in Mg/Ca and Sr/Ca within individual tests and chambers was determined by electron microprobe, and samples consisting of variable sample size were measured using inductively coupled plasma optical emission spectrometer (ICP‐OES). Large compositional heterogeneity was found within individual chambers, and within the test as a whole, of the two species and the presence of regions with up to ∼10 mmol/mol Mg/Ca, especially in G. bulloides. Mean Mg/Ca decreases in successive chambers of G. bulloides (especially the 300–355 μm fraction) and is accompanied by decreasing variance but is not statistical significant. Sr/Ca is much more homogeneously distributed, with a normal distribution, and shows no differences from chamber to chamber. The variability of Mg/Ca and Sr/Ca decreases with increasing sample size, from single to five to twenty tests per sample, approximately as for a normal distribution, with greater variability for G. bulloides than for G. truncatulinoides, equivalent to uncertainties in temperature (n = 20) of 1.1°C and 0.7°C for the two species within the whole of the sediment mixed layer.
Deformation and fluid flow of a major out‐of‐sequence thrust located at seismogenic depth in an accretionary complex: Nobeoka Thrust in the Shimanto Belt, Kyushu, Japan
Authors: Kondo Hideki , Kimura Gaku , Masago Hideki , Ohmori‐Ikehara Kotoe , Kitamura Yujin , Ikesawa Eisei , Sakaguchi Arito , Yamaguchi Asuka , Okamoto Shin'ya
Published: November 2005

Nobeoka Thrust in Kyushu, southwest Japan, was investigated to understand the relationship between the seismogenic out‐of‐sequence thrust (OST) and fluid flow in accretionary prisms. The Nobeoka Thrust is a fossilized OST, being active at seismogenic depth. The hanging wall exhibits a penetrative plastic deformation, while a brittle, cataclastic mélange‐like occurrence characterizes the footwall, although both of them have same shale and sandstone‐dominant protolith. Vitrinite reflectance analyses indicate that the maximum temperatures of the hanging wall and footwall are approximately 320 and 250°C, respectively. This thermal gap across the thrust corresponds to 8.6–14.4 km of displacement assuming a 28–47°C/km geothermal gradient. The brittle damage zone of the thrust is asymmetric: only 2 m for hanging wall side and 100 m for footwall. Three types of mineral veins, quartz, and carbonate are well developed, especially in the damaged footwall: the tension crack‐filling vein, the fault‐filling vein, and postmélange one. The first is harmonious with fabric, perpendicular to the P surface. Fluid inclusion geothermobarometry indicates the P‐T of fluid in the intensively damaged zone of the footwall is ∼300°C, 230–250 MPa, higher than that from vitrinite reflectance, which suggests that hydrothermal fluid flow is associated with deformation. The same type vein in the lowest portion of the footwall‐damaged zone includes a much lower P‐T fluid. This difference suggests that continuous underplating caused the damaged zone to propagate downward with cooling and shallowing, which differs from faults characterized by shear localization and might be unique to aquiferous OST in accretionary complexes.
Morphological and chemical modification of mineral dust: Observational insight into the heterogeneous uptake of acidic gases
Authors: Matsuki Atsushi , Iwasaka Yasunobu , Shi Guangyu , Zhang Daizhou , Trochkine Dmitri , Yamada Maromu , Kim Yoon‐Suk , Chen Bin , Nagatani Tetsuji , Miyazawa Takeshi , Nagatani Masahiro , Nakata Hiroshi
Published: November 2005

Aerosol samples were collected in the urban atmosphere of Beijing, China, by deploying a tethered balloon. Coarse particles (d > 1 μm) were individually analyzed using electron microscopes, to investigate the extent of dust modification by acidic gases in the atmosphere. Based on the elemental composition, irregularly shaped mineral dust was separated into carbonate and silicate groups. Both sulfate and nitrate were found to accumulate on carbonate more readily than silicate particles. Interestingly, spherical particles resembling Ca‐carbonate in composition were spotted frequently in the samples. These Ca‐rich spherical particles were more abundant under humid conditions, suggesting that they are deliquesced carbonate particles that formed in the atmosphere following the uptake of acidic gases. Sulfate and nitrate were more frequently detected in the Ca‐rich spherical particles than in carbonate in the original solid form, indicating that the gas uptake efficiency of carbonate is further enhanced after the phase transition.
A wave equation migration method for receiver function imaging: 1. Theory
Authors: Chen Ling , Wen Lianxing , Zheng Tianyu
Published: November 2005

A wave equation‐based poststack depth migration method is proposed to image the Earth's internal structure using teleseismic receiver functions. By utilizing a frequency wave number domain one‐way phase screen propagator for wave field extrapolation in the migration scheme, common conversion point (CCP) stacked receiver functions are backward propagated to construct a subsurface structural image. The phase screen propagator migration method takes into account the effects of diffraction, scattering, and travel time alternation caused by lateral heterogeneities, and therefore it is particularly useful for imaging complex structures and deep discontinuities overlain by strong shallow anomalies. Synthetic experiments demonstrate the validity of the migration method for a variety of laterally heterogeneous models. The migrated images show considerable improvement over the CCP images in recovering the model features. Influences of several factors on the image quality of the poststack migration are further investigated, including interstation spacing, noise level of the data, velocity model used in migration, and earthquake distribution (incident direction of source fields). On the basis of the sampling theorem and previous statistic results, we discuss the relation of spatial resolution and signal‐to‐noise ratio of the migrated image with the frequency of the data, surface station spacing and number of receiver functions used in stacking. We show that both CCP stacking and poststack migration of receiver functions need to be designed in a target‐oriented way for reliable and efficient imaging. Our results also suggest that careful consideration of earthquake source distribution is necessary in designing seismic experiments aimed at imaging steeply dipping structures.