bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding the properties of interfaces between organic self‐assembled monolayers and noble metals—a theoretical perspective
Authors: Rangger Gerold M. , Romaner Lorenz , Heimel Georg , Zojer Egbert 
Published: January 2008

AbstractHighly ordered, self‐assembled monolayers (SAMs) on (noble) metal surfaces are of particular importance for both the emerging field of single‐molecule electronics as well as for improving the characteristics of more conventional organic (opto)electronic devices. In the first part of this article, we review the microscopic description of electrode work function modification induced by SAMs and the alignment of molecular states relative to the states in the metal. The focus will be on the Ag(111) surface and biphenyl SAMs involving different donor–acceptor head‐group substituents. The impact of different docking groups will also be discussed and the results will be compared to previous findings (primarily) for SAMs on Au(111). The second part of the article deals with an in‐depth description of charge rearrangements and the hybridization between molecular and metal states by projecting the electronic states of the combined system onto the orbitals of the isolated molecules. Furthermore, the sulfur–silver bond is analyzed by means of a crystal orbital occupation population analysis. Copyright © 2008 John Wiley & Sons, Ltd.
The clinical effects of calcium sulfate combined with calcium carbonate in intrabony defects
Authors: Lee S. B. , Chae G. J. , Jung U. W. , Kim C. S. , Lee Y. K. , Cho K. S. , Chai J. K. , Kim C. K. , Choi S. H. 
Published: January 2008

AbstractBone grafts using calcium carbonate (CC) and guided tissue regeneration (GTR) using calcium sulfate (CS) will maximize their advantages and show the best clinical results in intrabony defects. The purpose of this study was to compare the effects of a combination of CS and CC with control treated only with modified widman flap in a periodontal repair of intrabony defects. As many as 30 patients at Yonsei University Hospital were enrolled in this study. Of this group, 10 patients were treated with a combination of CS and CC as the experimental group α another 10 were treated with CC as the experimental group β, and the remaining 10 patients, the control group, were treated only with modified widman flap. The results are follows: (i) The probing depth changes were significantly different (P < 0.05) between the control and experimental group. However, there were no significant differences (P < 0.05) between the experimental group β and α. (ii) The gingival recession changes were not significantly different (P < 0.05) among the groups. (iii) The attachment level changes were significantly different (P < 0.05) between the control and experimental group. However, there were no significant differences (P < 0.05) between the experimental group β and α. (iv) The bone probing depth changes were significantly different (P < 0.05) among the groups. On the basis of these results, it would be concluded that treatment using a combination of CS and CC had the potential to improve periodontal parameters in human intrabony defects. Copyright © 2008 John Wiley & Sons, Ltd.
Experimentell gestützte Verstärkung von Fachwerkknoten
Authors: Gutermann Marc , Meier Bodo , Melzer Veit 
Published: January 2008

AbstractFüllstäbe von Fachwerkkonstruktionen werden meist über ausgeschnittene Knotenbleche an Ober‐ und Untergurt angeschlossen. Kehlnähte zwischen Flansch und Knotenblech haben sich als wirtschaftliche Verbindung bewährt, da eine Schweißnaht zwischen Steg und Knotenblech sowie aufwendige Einpassarbeiten entfallen. Es wird ein Projekt vorgestellt, bei dem ein Verfahren zur Bemessung von ausgeschnittenen Knotenblechen bei einer Verstärkungsmaßnahme angewendet wurde. Belastungsversuche sichern dabei die Ergebnisse der analytischen Tragwerksplanung ab.
Messung und Auswertung von Verbundträgerverformungen
Authors: Grages Hauke , Lange Jörg 
Published: January 2008

AbstractGeschossdecken in Stahlverbundbauweise stellen im heutigen Parkhaus‐, Büro‐ und Industriebau eine wirtschaftliche Bauweise für weitgespannte, schlanke Decken dar. Um eine uneingeschränkte Nutzbarkeit des Bauwerks zu gewährleisten, werden im Nachweis der Gebrauchstauglichkeit die zu erwartenden Verformungen, Schwingungen und Rissbreiten ermittelt, die bereits in der Planung durch geeignete Maßnahmen beeinflusst werden können. In der Realität treten jedoch insbesondere bei den Verformungen erhebliche Abweichungen zwischen den berechneten und den am Bauwerk vorhandenen Verformungen auf.In [1] wurde das Verformungsverhalten von ausgeführten Verbundträgern analysiert, um Vorschläge zu entwickeln, mit denen Verformungen sicherer vorhergesagt werden können. Die Verformungsgeschichte von Verbundträgern wurde an vier Parkhäusern in Stahl‐Beton‐Verbundbauweise während der Bauphase ermittelt. Es zeigte sich, dass sich unter anderem bereits die Fertigung der Stahlträger im Stahlbaubetrieb auf das weitere Verformungsverhalten der Träger auswirkt.
Analyse der Einflüsse auf die Rissbildung infolge Flüssigmetallversprödung beim Feuerverzinken
Authors: Feldmann Markus , Pinger Thomas , Tschickardt Dirk , Bleck Wolfgang , Völling Alexander , Langenberg Peter 
Published: January 2008

AbstractIn dem Beitrag wird, ausgehend von typischen Schadensfällen, der Hintergrund der Rissbildung durch Flüssigmetallversprödung beim Feuerverzinken aufgezeigt. Dabei handelt es sich um ein Phänomen, das in den letzten Jahren verstärkt und nicht selten mit Auswirkung auf die Standsicherheit zu beobachten war. Dies gab Anlass für eingehende Forschungsarbeiten, deren Ergebnisse die Ursachen und Hintergründe der Rissbildung nun wesentlich aufhellen. Sie reichen über das gesamte Spektrum der Problematik, beginnend von den mikroskopischen Befunden, des Korngrenzenangriffs über die Ermittlung von Spannungs‐Dehnungszuständen bis hin zu griffigen Beurteilungsverfahren. Nach der Darstellung der maßgebenden Einflussfaktoren wie Zinkschmelzenzusammensetzung, Spannungs‐ Dehnungsentwicklung, Material, etc. werden auf Grundlage der aktuellen Forschungsergebnisse Empfehlungen zur Vermeidung der Rissbildung abgeleitet und vorgestellt.
Analysis of long chain sultones by thin layer chromatography
Authors: Wolf T. , McPherson B. P. 
Published: January 2008

Abstract and SummaryThe separation and semiquantitative estimation of nine C14 sultones by thin layer chromatography (TLC) on silica gel is reported. Vapor phase charring gives detection limits of several ppm in olefin sulfonate, ethoxylated alcohol sulfates, and formulated products. Isopropyl ether is the solvent of choice, and two‐dimensional TLC with this and a chlorinated solvent mixture gives an exclusive sultone area, as well as added sensitivity. Simplified preparative TLC on plates with preadsorbent is described for confirmation by independent analytical methods.
Synergistic antioxidant effect of nucleic acids and tocopherols
Authors: Ikeda Nobuo , Fukuzumi Kazuo 
Published: January 2008

Abstract and SummaryNucleic acids acted as synergists with tocopherols in inhibiting the oxidation of methyl linoleate. DNA and RNA enhanced the activity of tocopherols to different extents in the order α‐>γ‐>δ‐tocopherol. Nucleic acids decreased the rates of consumption of tocopherol in the presence of oxi‐dizing methyl linoleate. Nucleic acids also decreased the rate of oxidation of tocopherols by PbO2. The synergistic effect of nucleic acids seemed to be caused by hydrogen bond formation with tocopherols which protected toco‐pherols from direct air oxidation.
Computer‐ Controlled Automatic titration system and its application to the analysis of fats and oils
Authors: Fudano Shintaro , Kusuyama Takashi , Yashima Kazuaki , Terai Sakiko , Konishi Kazuo 
Published: January 2008

Abstract and SummaryAn automatic titration system (ATS) controlled by a microcomputer was developed for potentiometric or pH titrations. The titrator is equipped with a piston‐type glass buret which is operated by a stepping motor driven by computer‐generated pulse. The droplet volume of titrant is 0.00211 ml per pulse which enables very accurate titration. The titration rate is controlled by regulating the intervals of pulses according to the potential changes accompanying the progress of titration. The point giving the maximum pulse interval is detected automatically as the end point. Accordingly, it is not necessary to present the potential or pH value of the end point. Sample beakers are sent in turn with an endless mode. As examples of practical application of ATS, saponification value, amine value, acid value, total chlorine content, and chloride ion content were determined. The ATS makes it possible to contribute not only to the improvement of precision but to the simplification of analytical procedures in fats and oils chemistry.
Apoptotic Effects of Dietary and Synthetic Sphingolipids in Androgen‐Independent (PC‐3) Prostate Cancer Cells
Authors: Kent Kyle D. , Clubbs Elizabeth A. , Harper W. James , Bomser Joshua A. 
Published: January 2008

AbstractStress‐induced activation and metabolism of plasma membrane sphingolipids results in intracellular ceramide accumulation and has been shown to induce apoptosis in human prostate cancer cells. This effect has been observed using synthetic ceramide analogs, such as C6‐ceramide; however, the effects of naturally‐occurring sphingolipids, such as C18‐ceramide and sphingomyelin (CerPCho), on apoptosis and prostate cancer cell proliferation have not been examined. The results of the present study demonstrate that natural (CerPCho, C18‐ceramide) and synthetic (C6‐ceramide) sphingolipids reduced PC‐3 cell proliferation by 15 ± 1.8, 17 ± 2.5, and 46 ± 2.1%, respectively (P < 0.05). These reductions in proliferation were due, in part, to increased cellular apoptosis. Treatment of PC‐3 cells with CerPCho and C18‐ceramide significantly increased apoptosis by 3.0 ± 0.8 and 3.6 ± 0.6%, respectively, compared to the untreated control, while the synthetic C6‐ceramide significantly increased apoptosis by 55.7 ± 0.4%. C6‐ceramide‐induced apoptosis was associated with cell cycle arrest in the G2/M phase, decreased extracellular signal‐regulated kinase (ERK1/2) signaling and activation of the cell cycle regulatory protein, retinoblastoma (pRb). Treatment of PC‐3 cells with C18‐ceramide and CerPCho did not alter cell cycle distribution, pRb or ERK1/2 activation. Taken together, these results suggest that natural and synthetic sphingolipids induce apoptosis in PC‐3 cells via distinct signaling mechanisms and potencies.
Characterization and Oxidative Stability of Structured Lipids: Infant Milk Fat Analog
Authors: Maduko C. O. , Park Y. W. , Akoh C. C. 
Published: January 2008

AbstractStructured lipids (SLs) for infant milk formulation were produced by enzymatic interesterification of tripalmitin with vegetable oil blends and fish oil. The SLs were characterized by fatty acid content and structure, melting profiles, oxidative stability index, free fatty acid (FFA) concentration, and tocopherol content. Oxidative stability was studied using accelerated methods by quantifying FFA, peroxides (peroxide value) and aldehydes (p‐anisidine value) production. Total oxidation (TOTOX value) was calculated as 2 × (peroxide value) + (p‐anisidine value). The structured lipids after purification by distillation and addition of antioxidants had melting profiles, oxidative stability index, and initial FFA concentration that were similar to that of the starting oil blends, while the fatty acid composition and structure of the SLs were similar to that of human milk fat. Oxidative stability of the SLs was improved with tocopherol addition as antioxidants and was comparable to that of the vegetable oils and oil blends.
WEYL'S THEOREM FOR CLASSA(k) OPERATORS
Authors: IRENE MARY J. STELLA , PANAYAPPAN S. 
Published: January 2008

AbstractIn this paper we shall show that Weyl's theorem holds for classA(k) operatorsTwherek≥>1, via its hyponormal transform$\skew3\hat{T}$. Next we shall prove some applications of Weyl's theorem on classA(k) operators.
ON A FRIEDRICHS EXTENSION RELATED TO UNBOUNDED SUBNORMALS-II
Authors: CHAVAN SAMEER 
Published: January 2008

AbstractWe study the Friedrichs extensions of unbounded cyclic subnormals. The main result of the present paper is the identification of the Friedrichs extensions of certain cyclic subnormals with their closures. This generalizes as well as complements the main result obtained in [5]. Such characterizations lead to abstract Galerkin approximations, generalized wave equations, and bounded${\mathcal H}^{\infty}$-functional calculi.
ASYMPTOTIC BEHAVIOR OF EIGENVALUES OF RECIPROCAL POWER LCM MATRICES
Authors: HONG SHAOFANG , ENOCH LEE K. S. 
Published: January 2008

AbstractLet$\{x_i\}_{i=1}^{\infty}$be an arbitrary strictly increasing infinite sequence of positive integers. For an integern≥1, let$S_n=\{x_1, {\ldots}\, x_n\}$. Letr>0 be a real number andq≥ 1 a given integer. Let$\lambda _n^{(1)}\, {\le}\, {\ldots}\, {\le}\, \lambda _n^{(n)}$be the eigenvalues of the reciprocal power LCM matrix$(\frac{1}{[x_i, x_j]^r})$having the reciprocal power${1\over {[x_i, x_j]^r}}$of the least common multiple ofxiandxjas itsi,j-entry. We show that the sequence$\{\lambda _n^{(q)}\}_{n=q}^{\infty}$converges and${\rm lim}_{n\, {\rightarrow}\, \infty}\lambda _n^{(q)}=0$. We show that the sequence$\{\lambda _n^{(n-q+1)}\}_{n=q}^{\infty}$converges if$s_r:=\sum_{i=1}^{\infty}{1\over {x_i^r}}<\infty $and${\rm lim}_{n\, {\rightarrow}\, \infty}\lambda _n^{(n-q+1)}\, {\le}\, s_r$. We show also that ifr> 1, then the sequence$\{\lambda _{ln}^{(tn-q+1)}\}_{n=1}^{\infty}$converges and${\rm lim}_{n\, {\rightarrow}\, \infty}\lambda _{ln}^{(tn-q+1)}=0$, wheretandlare given positive integers such thatt≤l−1.
MOUFANG QUADRANGLES OF MIXED TYPE
Authors: STRUYVE KOEN , VAN MALDEGHEM HENDRIK 
Published: January 2008

AbstractIn this paper, we present some geometric characterizations of the Moufang quadrangles of mixed type, i.e., the Moufang quadrangles all the points and lines of which are regular. Roughly, we classify generalized quadrangles with enough (to be made precise) regular points and lines with the property that the dual nets associated to the regular points satisfy the Axiom of Veblen-Young, or a very weak version of the Axiom of Desargues. As an application we obtain a geometric characterization and axiomatization of the generalized inversive planes arising from the Suzuki-Tits ovoids related to a polarity in a mixed quadrangle. In the perfect case this gives rise to a characterization with one axiom less than in a previous result by the second author.
Characterization of an exported monoglyceride lipase from Mycobacterium tuberculosis possibly involved in the metabolism of host cell membrane lipids
Authors: Côtes Karen , Dhouib Rabeb , Douchet Isabelle , Chahinian Henri , de Caro Alain , Carrière Frédéric , Canaan Stéphane 
Published: January 2008

The Rv0183 gene of the Mycobacterium tuberculosis H37Rv strain, which has been implicated as a lysophospholipase, was cloned and expressed in Escherichia coli. The purified Rv0183 protein did not show any activity when lysophospholipid substrates were used, but preferentially hydrolysed monoacylglycerol substrates with a specific activity of 290 units·mg−1 at 37 °C. Rv0183 hydrolyses both long chain di- and triacylglycerols, as determined using the monomolecular film technique, although the turnover was lower than with MAG (monoacyl-glycerol). The enzyme shows an optimum activity at pH values ranging from 7.5 to 9.0 using mono-olein as substrate and is inactivated by serine esterase inhibitors such as E600, PMSF and tetrahydrolipstatin. The catalytic triad is composed of Ser110, Asp226 and His256 residues, as confirmed by the results of site-directed mutagenesis. Rv0183 shows 35% sequence identity with the human and mouse monoglyceride lipases and well below 15% with the other bacterial lipases characterized so far. Homologues of Rv0183 can be identified in other mycobacterial genomes such as Mycobacterium bovis, Mycobacterium smegmatis, and even Mycobacterium leprae, which is known to contain a low number of genes involved in the replication process within the host cells. The results of immunolocalization studies performed with polyclonal antibodies raised against the purified recombinant Rv0183 suggested that the enzyme was present only in the cell wall and culture medium of M. tuberculosis. Our results identify Rv0183 as the first exported lipolytic enzyme to be characterized in M. tuberculosis and suggest that Rv0183 may be involved in the degradation of the host cell lipids.
The widely utilized brominated flame retardant tetrabromobisphenol A (TBBPA) is a potent inhibitor of the SERCA Ca2+ pump
Authors: Ogunbayo Oluseye A. , Michelangeli Francesco 
Published: January 2008

TBBPA (tetrabromobisphenol A) is currently the most widely used type of BFR (brominated flame retardant) employed to reduce the combustibility of a large variety of electronic and other manufactured products. Recent studies have indicated that BFRs, including TBBPA, are bio-accumulating within animal and humans. BFRs including TBBPA have also been shown to be cytotoxic and potentially endocrine-disrupting to a variety of cells in culture. Furthermore, TBBPA has specifically been shown to cause disruption of Ca2+ homoeostasis within cells, which may be the underlying cause of its cytotoxicity. In this study, we have demonstrated that TBBPA is a potent non-isoform-specific inhibitor of the SERCA (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase) (apparent Ki 0.46–2.3 μM), thus we propose that TBBPA inhibition of SERCA contributes in some degree to Ca2+ signalling disruption. TBBPA binds directly to the SERCA without the need to partition into the phospholipid bilayer. From activity results and Ca2+-induced conformational results, it appears that the major effect of TBBPA is to decrease the SERCA affinity for Ca2+ (increasing the Kd from approx. 1 μM to 30 μM in the presence of 10 μM TBBPA). Low concentrations of TBBPA can quench the tryptophan fluorescence of the SERCA and this quenching can be reversed by BHQ [2,5-di-(t-butyl)-1,4-hydroquinone] and 4-n-nonylphenol, but not thapsigargin, indicating that TBBPA and BHQ may be binding to similar regions in the SERCA.
The pharmacology of endosomal TLR agonists in viral disease
Authors: Averett D.R. , Fletcher S.P. , Li W. , Webber S.E. , Appleman J.R. 
Published: January 2008

The discovery of endosomal TLRs (Toll-like receptors) and their natural ligands has accelerated efforts to exploit them for therapeutic benefit. Importantly, this was preceded by clinical exploration of agents now known to be endosomal TLR agonists. Clinical effects in viral disease have been reported with agonists of TLR3, TLR7, TLR7/8 and TLR9, and the TLR7 agonist imiquimod is marketed for topical use against warts, a papillomavirus disease. The observed pre-clinical and clinical profiles of agonists of each of these TLRs suggest induction of a multifaceted innate immune response, with biomarker signatures indicative of type 1 interferon induction. However, these agents differ in both their pharmaceutical characteristics and the cellular distribution of their target TLRs, suggesting that drugs directed to these targets will display differences in their overall pharmacological profiles.
Immobilization of thermophilic enzymes in miniaturized flow reactors
Authors: Hickey A.M. , Marle L. , McCreedy T. , Watts P. , Greenway G.M. , Littlechild J.A. 
Published: January 2008

The exploitation of enzymes for biotransformation reactions for the production of new and safer drug intermediates has been the focus of much research. While a number of enzymes are commercially available, their use in an industrial setting is often limited to reactions that are cost-effective and they are rarely investigated further. However, the development of miniaturized flow reactor technology has meant that the cost of such research, once considered cost- and time-inefficient, would be much less prohibitive. The use of miniaturized flow reactors for enzyme screening offers a number of advantages over batch enzyme assay systems. Since the assay is performed on a miniaturized scale, enzyme, substrate and cofactor quantities are significantly reduced, thus reducing the cost of laboratory-scale investigations. Since flow reactors use microfluidic systems, where the substrate and products flow out of the system, the problems of substrate inhibition and product inhibition encountered by some enzymes are avoided. Quite often, enzymes fulfil a single-use function in biotransformation processes; however, enzyme immobilization allows enzyme reuse and often helps to increase enzyme stability. We have used an aminoacylase enzyme with potential use for industrial biotransformation reactions and have successfully immobilized it in miniaturized flow reactors. This L-aminoacylase is from the thermophilic archaeon Thermococcus litoralis. Two approaches to enzyme immobilization have been examined, both involving enzyme cross-linking. The first reactor type has used monoliths, to which the enzyme was attached, and the second contained previously cross-linked enzyme trapped using frits, in the microfluidic channels. Two different microreactor designs were used in the investigation: microreactor chips for the monoliths and capillary flow reactors for the cross-linked enzyme. These systems allowed passage of the substrate and product through the system while retaining the aminoacylase enzyme performing the catalytic conversion. The enzyme has been successfully immobilized and used to produce stable biocatalytic microreactors that can be used repeatedly over a period of several months.
High-Field Superconductivity
Authors: Larbalestier David , Fisk Gene , Montgomery Bruce , Hawksworth David 
Published: January 2008

One does not often read original research communications that are 50 or 75 years old. Preparing an article to commemorate the 75th anniversary of the discovery of superconductivity seemed to be an appropriate occasion for reading some of Heike Kamerlingh Onnes's original articles. Two years after his discovery, Onnes made a report to the third International Conference of Refrigeration in 1913. He reviewed the recent research of his Leiden group. This article is quite astonishing, and only extensive quotations can convey the breadth of Onnes's conception of the possibilities of the superconducting state. Onnes commences his description of the superconducting state by describing his initial 1911 experiments on mercury, but he proceeds rapidly to sketch whole segments of the technology of superconducting magnets:
Mercury has passed into a new state, which on account of its extraordinary electrical properties may be called the superconductive state…. The behavior of metals in this state gives rise to new fundamental questions as to the mechanism of electrical conductivity.
It is therefore of great importance that tin and lead were found to become superconductive also. Tin has its step-down point at 3.8 K, a somewhat lower temperature than the vanishing point of mercury. The vanishing point of lead may be put at 6 K. Tin and lead being easily workable metals, we can now contemplate all kinds of electrical experiments with apparatus without resistance….
SQUIDs, Brains and Gravity Waves
Authors: Clarke John 
Published: January 2008

▸ A lonely instrument in Baja California records tiny fluctuations in the Earth's magnetic field, giving valuable information on the location of geothermal energy.
▸ An extremely quiet amplifier detects electrical noise generated by the fluctuating spins in a collection of chlorine nuclei—the first observation of nuclear-spin noise.
▸ Superconducting gradiometers in liquid helium measure tiny fluctuating magnetic fields emanating from the human brain (see figure 1), pinpointing the source of the electrical discharge associated with focal epilepsy.
▸ An aluminum bar weighing 4800 kg and cooled to 4.2 K rests in a vacuum chamber at Stanford University, working as the world's most sensitive monitor of gravitational radiation.