bluuebunny/crossref_metadata_2025 huggingface dataset:
Eisen und Eisenmangel aus medizin‐ und pharmaziehistorischer Sicht. Die Maske des Mars
Authors: Müller Irmgard
Published: April 2009

Ähnlich wie bei den Avitaminosen war auch bei den Eisen‐Mangelkrankheiten der Weg zu ihrer Entschlüsselung reich an Umwegen und von vielen Rückschlägen, Missverständnissen und Irrgängen gezeichnet. Die Vorstellung, dass etwas nicht Vorhandenes, eine negative Entität, eine Krankheit hervorbringen sollte, lag lange Zeit außerhalb des ärztlichen Denkens, das gewohnt war, in konkreten Substraten mit quantitativen Begriffen sich auf Spurensuche zu begeben.
Eisen‐Stoffwechselstörungen. Diagnose und Therapie
Authors: Heimpel Hermann , Bommer Martin
Published: April 2009

Eisen gehört zu den für die vitalen Körperfunktionen aller höheren Tiere notwendigen “Spurenelemente”. Innerhalb dieser Gruppe nimmt Eisen insofern eine Sonderstellung ein, als es in vergleichsweise großer Menge vorhanden ist und dass sowohl Mangelzustände als auch klinisch relevante Zustände von Eisen‐Überladung häufiger vorkommen als bei allen anderen Metallen.
Prävention und Therapie der Osteoporose. Stellenwert von Calcium und Vitamin D
Authors: Bartl Reiner
Published: April 2009

Eine Monotherapie mit Vitamin D und Calcium ist zur Behandlung der postmenopausalen Osteoporose nicht geeignet. Die Supplementation von Calcium und Vitamin D3 ist aber generell als Basistherapie bei Patienten mit Risikofaktoren und obligat als additive Begleittherapie bei jeder medikamentösen Osteoporosetherapie indiziert und sogar unerlässlich (siehe DVO‐Leitlinien). Nach mehrjähriger Behandlung mit effektiven Antiosteoporotika wird oft Calcium plus Vitamin D allein im Sinne einer “Erhaltungstherapie” fortgeführt. Die Datenlage zur fraktursenkenden Wirkung von Calcium und/oder Vitamin D erlaubt folgende Einschätzungen:

˙ Wirkung gesichert: Verminderung von Schenkelhalsfrakturen bei Frauen in Altenheimen mit einem Calcium‐ und Vitamin‐D‐Mangel durch die kombinierte Gabe von Vitamin D plus Calcium.

˙ Wirkung wahrscheinlich: Verminderung von peripheren Frakturen bei Frauen und Männern im höheren Lebensalter mit Calcium‐ und Vitamin‐D‐Mangel durch die kombinierte Gabe von Vitamin D plus Calcium.

˙ Wirkung möglich: Verminderung von peripheren Frakturen und Wirbelkörperfrakturen bei Männern und Frauen in allen Altersklassen durch eine Optimierung der Calcium‐ und Vitamin‐D‐Versorgung.

Bei älteren Menschen muss die Vitamin‐D‐Gabe wegen der mangelhaften Produktion in der Haut Sommer wie Winter erfolgen. Die Serumkonzentration an 25‐Hydroxyvitamin D sollte mindestens 20 ng/mL und durchschnittlich 30 ng/mL betragen. Um diesen Spiegel zu erreichen, ist eine tägliche Aufnahme von ca. 800 IE (20 μg) Vitamin D erforderlich. Eine Vitamin‐D‐ und Calcium‐Zufuhr ist insbesondere in der Schwangerschaft und Stillzeit angezeigt. Wir empfehlen in unserer Ambulanz zur Prävention der Therapie der Osteoporose als Basistherapie die “1000er Regel”: täglich 1000 mg Calcium und 1000 IE Vitamin D3.

Vitamin D reduziert ferner das Sturzrisiko, verbessert die Muskelkraft und besitzt noch zahlreiche positive Wirkungen auf andere Organsysteme. Das Auftreten von Nierensteinen oder einer Gefäßverkalkung ist bei Osteoporose‐Patienten in der empfohlenen Dosis und bei normaler Flüssigkeitszufuhr nicht zu befürchten.

Der Einsatz aktiver Vitamin‐D‐Metabolite ist auf Grund der Studiendatenlage zur Therapie der postmenopausalen Osteoporose nicht zu empfehlen und nur bei Funktionsstörungen der Leber und/oder Niere zu diskutieren. Ein unkritischer Einsatz von hydroxylierten Formen des Vitamin D bei Sturzpatienten ist auch aus Kostengründen nicht sinnvoll. Eine Substitution mit anderen Mineralien, Vitaminen oder Spurenelementen ist nur bei Vorliegen von nachgewiesenen Mangelzuständen sinnvoll und vertretbar.
Mineralstoffe und Spurenelemente – ein Fall für die Beratung. In der Apotheke
Authors: Ude Miriam , Hengstler Susanne , Schulz Martin , Müller Walter E. , Leuner Kristina
Published: April 2009

Nahrungsergänzungsmittel sind heute aus der Apotheke nicht mehr wegzudenken. Trotzdem ist nicht jede Supplementierung ein Fall für die Selbstmedikation. Bei der Abgabe von Calcium‐, Magnesium‐ oder Eisen‐Präparaten sollte der Apotheker den Patienten auf Besonderheiten der Einnahme, Nebenwirkungen, Wechselwirkungen und Limitationen der Selbstmedikation hinweisen. Konkrete, individualisierte Empfehlungen sind von größerem Nutzen als der allgemeine Hinweis auf eine “ausgewogene und gesunde Ernährung”. Hinweise zur Erstattungsfähigkeit von Calcium‐, Magnesium‐ oder Eisen‐Präparaten sind in Tabelle 4 gegeben.
Polypropylene/silica nanocomposites prepared by in‐situ melt ultrasonication
Authors: Tan Xiumin , Xu Yongshen , Cai Na , Jia Guangwei
Published: April 2009

A novel process using ultrasonic irradiation to enhance nanosilica dispersion in polypropylene‐based nanocomposites has been proposed and investigated. The nanocomposites were isotactic polypropylene reinforced with silica nanoparticles at 3 wt% loading level. Ultrasonic processing in the melt state is an effective method for improving nanosilica dispersion. The effectiveness of the proposed ultrasonic processing technique on polypropylene nanocomposites was evaluated by XRD and transmission electron microscopy (TEM). Poly(propylene‐g‐maleic anhydride) copolymer (PP‐g‐MAH) containing 5 wt% maleic anhydride content was added to nanocomposites at 0.5 wt% concentration based on silica content. PP‐g‐MAH plays an important role in nanosilica dispersion in polymer matrix and interface interaction. The reaction of maleic anhydride groups with the hydroxyl groups on the surface of nanosilica was characterized by FTIR spectrum. The final nanocomposites result in a further enhancement of mechanical properties because of silica agglomerate reduction and improving interface combination, even loading level being much lower than that of ordinary fillers in conventional composites. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers
Reference values for γ‐glutamyl‐transferase in amniotic fluid in normal pregnancies
Authors: Bardin Ron , Danon David , Tor Ruth , Mashiach Reuven , Vardimon David , Meizner Israel
Published: April 2009

Objective

Nonvisualization of the fetal gallbladder by ultrasound poses a diagnostic dilemma. The aim of the study was to establish reference values for the hepatobiliary enzyme γ‐glutamyl‐transferase (GGT) in amniotic fluid in normal pregnancies, and to determine the maximal week of gestation in which reference values can be determined.

Method

A cross‐sectional design was used. The study group consisted of pregnant women at 16 gestational weeks or more referred to our ultrasound unit for amniocentesis. Amniotic fluid was assayed for levels of GGT and other hepatobiliary enzymes using the Integra 800 device. The 5th and 95th percentiles for each gestational week were calculated.

Results

A total of 263 samples were analyzed. After conversion to log units, enzyme levels showed a good correlation with gestational week (Pearson). The mean values and the 5th and 95th percentiles were calculated for gestational weeks 16 to 22. Beyond 22 weeks, the number of examinations was insufficient for analysis. On multiple regression analysis, log values of alkaline phosphatase, maternal age, and gestational age independently affected log GGT values. Levels of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase were too low, and their correlation with gestational week too poor for calculation of reference values.

Conclusion

GGT reference values in amniotic fluid in normal pregnancies were defined for gestational weeks 16 to 22. These data may be useful for differentiating isolated absence of fetal gallbladder from extrahepatic biliary atresia. Copyright © 2009 John Wiley & Sons, Ltd.
Competition between chain scission and branching formation in the processing of high‐density polyethylene: Effect of processing parameters and of stabilizers
Authors: Scaffaro R. , La Mantia F.P. , Botta L. , Morreale M. , Tz. Dintcheva N. , Mariani P.
Published: April 2009

Two samples of high‐density polyethylene with different molecular weight were processed in a batch mixer and the rheological and structural properties were investigated. In particular, the effect of different processing parameters and the eventual presence of different stabilizers were evaluated. Actually, two reactions may occur during processing: branching/crosslinking or chain scission. The results indicate that when the processing conditions promote a scarce mobility of the macromolecular chains (lower temperatures, lower mixing speed, and higher molecular weight), branching is more favored than chain scission. On increasing the mobility of the chain (higher temperature, higher mixing speed, and lower initial molecular weight), branching appears still the predominant reaction, but the chain scission becomes progressively more important. In both cases, no crosslinking occurs. The presence of stabilizers has different effects on the relative extent of branching or chain scission reactions depending on the kind and of the amount of stabilizer and on the processing condition adopted. The correct choice of a stabilizer system will, therefore, depend on the desired final structure. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Thermal properties of an epoxy cresol‐formaldehyde novolac/diaminodiphenyl sulfone system modified by bismaleimide containing tetramethylbiphenyl and aromatic ether structures
Authors: Zhou Bo Xuan , Huang Yi Jun , Zhang Xing Hong , Fu Zhi Sheng , Qi Guo Rong
Published: April 2009

A bismaleimide monomer, 4,4′‐bis(4‐maleimidophenoxy)‐3,3′,5,5′‐tetramethyl biphenyl (BMITB), was synthesized in high yield (94%) via a facile four‐step reaction from 2,2′,6,6′‐tetramethyl‐4,4′‐biphenol. The chemical structure of BMITB was confirmed by FTIR, 1H NMR, 13C NMR and elemental analysis. The monomer used to modify the epoxy cresol‐formaldehyde novolac resin (ECN)/diaminodiphenyl sulfone (DDS) system. Cured ECN/BMITB/DDS blends with higher BMITB content had two distinct glass transition temperatures that were above 250°C according to differential scanning calorimetry, indicating that an interpenetrated polymer network structure may be formed. The initial thermal decomposition temperature and integral procedure decomposition temperature of the cured ECN/BMITB/DDS blends were >390 and 1080°C, respectively, according to thermogravimetric analyses. No phase separation was observed in dynamic mechanical analysis of cured ECN/BMITB/DDS blends with small amounts of BMITB (5 and 10 wt%). POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Effect of clay/water ratio during bentonite clay organophilization on the characteristics of the organobentonites and its polypropylene nanocomposites
Authors: Silva Suédina M.L. , Araújo Paolo E.R. , Ferreira Kaline M. , Canedo Eduardo L. , Carvalho Laura H. , Raposo Claudia M.O.
Published: April 2009

A sodium bentonite (montmorillonite‐based layered silicate clay) was organically modified with cetyl trimethyl ammonium bromide (cetrimide), using different clay/water ratios—but the same clay/cetrimide ratio—to suspend the bentonite clay and perform its organophilization. Infrared spectroscopy and thermogravimetric analysis indicated the incorporation of organic modifier into the bentonite. Wide‐angle X‐ray scattering showed that the incorporation of surfactant significantly increased the interlayer spacing in the bentonite for all concentrations studied. It was found that clay/water ratio employed during the modification affects neither the amount of organic salt incorporated nor the interlayer spacing in the organobentonites, but influences its degree of structural disorder. Lower clay/water ratios resulted in a more disorderly structure, as established by the decrease of the areas under the X‐ray peaks as the clay/water ratio diminishes. The modified bentonites were melt compounded with maleic anhydride‐grafted polypropylene. X‐ray diffraction patterns of the hybrids revealed that the more disorderly organobentonites were better dispersed in the polymer matrix, indicating that, in the present system, the structure of polymer nanocomposites obtained were affected by the clay/water ratio used in organobentonite preparation. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Analysis of the structure and mass transport properties of nanocomposite polyurethane
Authors: Esposito Corcione C. , Mensitieri G. , Maffezzoli A.
Published: April 2009

In this work, nanocomposite adhesives obtained using an organically modified montmorillonite (OMM) in a polyurethane matrix were studied. The basal distance of OMM before and after mixing with the polyol and after curing was characterized by X‐Ray diffraction. The viscosity of polyols‐OMM systems was studied as function of shear rate in a cone‐plate rheometer in order to correlate the viscosity with the aggregation state of OMM. A simple model accounting for an apparent increase of rheological units size associated with the intercalation of macromolecules into OMM galleries is proposed. Curing was performed at room temperature for 1 week. The basal distances of crosslinked PU nanocomposites were obtained by X‐ray diffraction. The glass transition temperature, Tg, of PU nanocomposites, as measured using differential scanning calorimetry, increases with increasing volume fraction of OMM. Finally, the permeability to oxygen and water vapor of polyurethane clay‐nanocomposites was measured. The gas permeation through the composites was correlated to the volume fraction of the impermeable inorganic part of the OMM. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Die Magnetkanone. Spielwiese
Authors: Ucke Christian , Schlichting Hans‐Joachim
Published: April 2009

Mit den heute günstig erhältlichen Stahl‐ und Magnetkugeln lassen sich überraschende Experimente realisieren. Aufeinander prallende Kugeln können eine Art Schusseffekt induzieren, der auch als magnetische Kanone bezeichnet wird. Mit wenigen und einfachen Hilfsmitteln lassen sich Messungen machen, mit deren Hilfe quantitativ befriedigende Berechnungen möglich sind. Diese Experimente erlauben Variationen, die dem Spiel‐ und Forschungstrieb von Physikinteressierten aller Couleur ein weites Feld eröffnen.
Astronomie in die Schulen
Authors: Clausnitzer Lutz
Published: April 2009

Wir betreiben eine bemannte Forschungsstation im Erdorbit, schmieden Pläne für den bemannten Flug zum Mars und fotografieren extrasolare Planeten. Doch an unseren jungen Menschen geht diese Entwicklung weitgehend unverstanden vorüber. Die meisten von ihnen kommen in der Schule über das heliozentrische Weltbild des 16./17. Jahrhunderts kaum hinaus. Ein Unterrichtsfach Astronomie würde nicht nur diesen Missstand beheben, sondern überdies das von Kultusministern geforderte komplexe, interdisziplinäre Arbeiten fördern.
Der astigmatische Astronom
Authors: Loos Andreas
Published: April 2009

Er ist arm und ein Snob. So jedenfalls berichten es die Biographen: Er sei introvertiert, aber keineswegs schüchtern gewesen, ein Kind, das mit seinen Schulkameraden nichts anfangen konnte. Als er zwölf Jahre alt ist, verliert sein Vater seine Arbeit, und die Familie gerät in Armut. Doch das junge Talent sollte sich zum Royal Astronomer in Greenwich entwickeln.
Eiskonfekt – Physics meets Physiology
Authors: Vilgis Thomas
Published: April 2009

Eiskonfekt ist immer eine kleine Sensation: Kaum ist das gute Stück im Mund, schon wird es auf der Zunge angenehm kühl. Aber hinter dieser banalen Beobachtung verbergen sich eine ganze Reihe physikalischer Vorgänge, die sich vor allem auf Schmelzprozesse von “Fettlegierungen” zurückführen lassen. Eiskonfekt ist somit ein Paradebeispiel für das Wechselspiel zwischen Thermodynamik und Zungenphysiologie.
The Role of inclusion size in toughening of epoxy resins by spherical micelles
Authors: Thio Yonathan S. , Wu Junxian , Bates Frank S.
Published: April 2009

We report our finding of an optimal length scale for toughening of epoxies using spherical micelles formed by block copolymers. The amphiphilic diblock copolymer poly(hexylene oxide)‐poly(ethylene oxide) (PHO‐PEO) with 30 wt % PEO self‐assembled to form spherical micelles in a bisphenol A epoxy resin with a phenol novolac hardener. We systematically increased the size of the spherical micelles from 20–30 nm to 0.5–10 μm by swelling their PHO core using PHO homopolymer. Although all the blends were tougher than the unmodified epoxy, the largest enhancement of fracture resistance was measured in blends containing 0.1–1 μm spherical inclusions. This enhanced toughness was correlated with plastic deformation by shear banding in tensile test and greater roughness of the fracture surface. Smaller micelles neither induced plastic deformation nor contributed to surface roughness significantly whereas larger micelles acted as local defects resulting in early failure. These findings provide a framework in assessing the toughening effects of blended block copolymers on epoxy resins. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1125–1129, 2009
POSS‐nylon 6 nanocomposites: Influence of POSS structure on surface and bulk properties
Authors: Misra Rahul , Fu Bruce X. , Plagge Andreas , Morgan Sarah E.
Published: April 2009

Hybrid organic/inorganic nanocomposites based on polyhedral oligomeric silsesquioxane (POSS) nanostructured chemicals and nylon 6 were prepared via melt mixing. Two structurally and chemically different POSS molecules, a closed cage, nonpolar octaisobutyl POSS (Oib‐POSS) and an open cage, polar trisilanolphenyl POSS (Tsp‐POSS) with differing predicted solubility parameters were evaluated in the nylon matrix. Surface analysis, including quasi‐static and dynamic nanoindentation and nanotribological techniques, revealed exceptional improvements in modulus and hardness along with significant reductions in friction. Additionally, surface wetting characteristics of the nylon were reversed, with POSS incorporation yielding low surface energy, highly hydrophobic surfaces. AFM, TEM/EDAX, spectroscopic techniques and thermomechanical analysis were used to evaluate nanoscale dispersion and bulk properties of the composites. Both POSS molecules exhibit preferential surface segregation behavior in the nylon matrix. Tsp‐POSS, with its higher predicted solubility in nylon, exhibited enhanced dispersion and tribomechanical properties at both nano and bulk scale. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1088–1102, 2009
The prostatic environment suppresses growth of androgen‐independent prostate cancer xenografts: An effect influenced by testosterone
Authors: Jennbacken Karin , Gustavsson Heléne , Tešan Tajana , Horn Michael , Vallbo Christina , Welén Karin , Damber Jan‐Erik
Published: April 2009

BACKGROUND

Interactions between prostate cancer cells and their surrounding stroma play an important role in the growth and maintenance of prostate tumors. To elucidate this further, we investigated how growth of androgen‐dependent (AD) LNCaP and androgen‐independent (AI) LNCaP‐19 prostate tumors was affected by different microenvironments and androgen levels.

METHODS

Tumor cells were implanted subcutaneously and orthotopically in intact and castrated immunodeficient mice. Orthotopic tumor growth was followed by magnetic resonance imaging (MRI). Gene expression in the tumors was evaluated by means of microarray analysis and microvessel density (MVD) was analyzed using immunohistochemistry.

RESULTS

The results showed that LNCaP‐19 tumors grew more rapidly at the subcutaneous site than in the prostate, where tumors were obviously inhibited. Castration of the mice did not affect ectopic tumors but did result in increased tumor growth in the prostatic environment. This effect was reversed by testosterone treatment. In contrast to LNCaP‐19, the LNCaP cells grew rapidly in the prostate and castration reduced tumor development. Gene expression analysis of LNCaP‐19 tumors revealed an upregulation of genes, inhibiting tumor growth (including ADAMTS1, RGS2 and protocadherin 20) and a downregulation of genes, promoting cell adhesion and metastasis (including N‐cadherin and NRCAM) in the slow‐growing orthotopic tumors from intact mice.

CONCLUSIONS

The results show that the prostatic environment has a varying impact on AD and AI tumor xenografts. Data indicate that the androgen‐stimulated prostatic environment limits growth of orthotopic AI tumors through induction of genes that inhibit tumor growth and suppression of genes that promote cell adhesion and metastasis. Prostate 69:1164–1175, 2009. © 2009 Wiley‐Liss, Inc.
Synthesis of new modified truncated peptides and inhibition of glycogen phosphorylase
Authors: Schweiker Stephanie S. , Loughlin Wendy A. , Brown Christopher L. , Pierens Gregory K.
Published: April 2009

The first solution state structural analysis (NMR) of the C‐terminal sequence of human GL that binds to glycogen phosphorylase a (GPa), PEWPSYLGYEKLGPYY‐NH2 (1), showed it to be in a random coil conformation. This was supported by molecular dynamics simulation (modelled in solution) using NAMD 2.6. The conformational ambiguity of the peptide makes the structural arrangement of the peptide (and internal residues) strongly dependent on the environment. Thirteen tetra‐peptide fragments of the C‐terminal sequence, YEKLG‐NH2, and the corresponding tri‐ and di‐peptide sequences were used in a fragment screen against GPa. Compound 2 (H‐GPYY‐NH2) did not give an IC50 value, whereas PEWPSYLGYEKLGPYY‐NH2 (1) displayed an IC50 of 34 µM against GPa. Truncated peptides derived from 1, (EKL‐NH2, EKLG‐NH2, and AcEKNH2) inhibited GPa (21%, 32%, 63%, respectively at 22 mM). These studies suggest key residues within the peptide chain have additional molecular interactions with GPa. The interaction of intra‐sequence residues in combination with the terminal residues of PEWPSYLGYEKLGPYY with GPa may form the basis for the design of new inhibitors of GPa. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Analysis of urinary nucleosides as helper tumor markers in hepatocellular carcinoma diagnosis
Authors: Jeng Long‐Bin , Lo Wan‐Yu , Hsu Wei‐Yi , Lin Wei‐De , Lin Chiung‐Tsung , Lai Chien‐Chen , Tsai Fuu‐Jen
Published: April 2009

Hepatocellular carcinoma (HCC) is a common neoplasm in Taiwan, for which early diagnosis is difficult and the prognosis is usually poor. HCC is usually diagnosed by abdominal sonography and serum alpha‐fetoprotein (AFP) detection. Modified nucleosides, regarded as indicators for the whole‐body turnover of RNAs, are excreted in abnormal amounts in the urine of patients with malignancies and can serve as tumor markers. We analyzed the excretion patterns of urinary nucleosides from 25 HCC patients and 20 healthy volunteers by high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI‐MS/MS) under optimized conditions. The HPLC/ESI‐MS/MS approach with selective reaction monitoring (SRM) allowed for the sensitive determination of nucleosides in human urine samples. The mean levels of the urinary nucleosides adenosine, cytidine, and inosine were significantly higher in HCC patients than healthy volunteers (average of 1.78‐, 2.26‐, and 1.47‐fold, respectively). However, the mean levels of urinary 1‐methyladenosine, 3‐methylcytidine, uridine, and 2′‐deoxyguanosine were not significantly different. Combined with the determination of serum AFP levels, the higher levels of urinary adenosine, cytidine, and inosine may be additional diagnosis markers for HCC in Taiwanese patients. Copyright © 2009 John Wiley & Sons, Ltd.
Complexation of late transition metal(II) ions (M = Co, Ni, Cu, and Zn) by a macrocyclic thiacrown ether studied by means of electrospray ionization mass spectrometry
Authors: Tsierkezos Nikos G. , Buchta Michal , Holý Petr , Schröder Detlef
Published: April 2009

Electrospray ionization mass spectrometry (ESI‐MS) is used to probe the metal‐binding selectivity of a macrocyclic thiacrown ether (C44H32S20) towards CoII, NiII, CuII, and ZnII. In homogeneous 1:1 v/v methanol/dichloromethane solutions, it is found that the thia ligand very selectively binds traces of copper even in the presence of an excess of the other metal ions. The large selectivity is ascribed to the redox‐active nature of copper which enables a reduction from CuII to CuI, occurring upon ESI‐MS, whereas CoII, NiII and ZnII cannot undergo similar redox reactions. Copyright © 2009 John Wiley & Sons, Ltd.
A high‐throughput bioanalytical platform using automated infusion for tandem mass spectrometric method optimization and its application in a metabolic stability screen
Authors: Kieltyka Kasia , Zhang Jun , Li Shu , Vath Marianne , Baglieri Chris , Ferraro Cheryl , Zvyaga Tatyana A. , Drexler Dieter M. , Weller Harold N. , Shou Wilson Z.
Published: April 2009

Liquid chromatography/tandem mass spectrometry (LC/MS/MS) is the bioanalytical method of choice to support plate‐based, in vitro early ADME (Absorption, Distribution, Metabolism and Excretion) screens such as metabolic stability (Metstab) assessment. MS/MS method optimization has historically been the bottleneck in this environment, where samples from thousands of discrete compounds are analyzed on a monthly basis, mainly due to the lack of a high‐quality commercially available platform to handle the necessary MS/MS method optimization steps for sample analysis by selected reaction monitoring (SRM) on triple quadrupole mass spectrometers. To address this challenge, we recently developed a highly automated bioanalytical platform by successfully integrating QuickQuan™ 2.0, a unique high‐throughput solution featuring MS/MS method optimization by automated infusion, with a customized in‐house software tool in support of a Metstab screen. In this platform, a dual‐column setup running parallel chromatography was also implemented to reduce the bioanalytical cycle time for LC/MS/MS sample analysis. A set of 45 validation compounds was used to demonstrate the speed, quality and reproducibility of MS/MS method optimization, sample analysis, and data processing using this automated platform. Metstab results for the validation compounds in microsomes from multiple species (human, rat, mouse) showed good consistency within each batch, and also between batches conducted on different days. We have achieved and maintained a monthly throughput of 1300 compound assays representing 500 discrete compounds per instrument per month on this platform, and it has been used to generate metabolic stability data for more than 25 000 compounds to date with an overall success rate of more than 95%. Copyright © 2009 John Wiley & Sons, Ltd.
Doping control analysis for adrafinil and its major metabolites in human urine
Authors: Lu Jianghai , Wang Xiaobing , Yang Shuming , Liu Xin , Qin Yang , Shen Li , Wu Yun , Xu Youxuan , Wu Moutian , Ouyang Gangfeng
Published: April 2009

A new and reliable two‐step liquid chromatography/tandem mass spectrometry (LC/MS/MS) method in combination with gas chromatography/mass spectrometry (GC/MS) for the screening and confirmation of adrafinil and its major metabolites, modafinil and modafinil acid, in human urine has been developed and validated. The method involved reversed‐phase C18 solid‐phase extraction (SPE) cartridge extraction and MS analysis by means of LC/MS/MS and GC/MS. The study illustrated that the ESI capillary temperature played a key role in the formation of the protonated molecule. The limits of detection (LODs) of the developed method for the three compounds were lower than the minimum required performance limit (MRPL) of the World Anti‐Doping Agency (WADA). The human urine samples obtained after the oral administration of modafinil and from the Beijing 2008 Olympic Games were analyzed by using the described method, which has also been successfully applied to routine analyses and the WADA Proficiency Test. Copyright © 2009 John Wiley & Sons, Ltd.
Precise and fast secondary ion mass spectrometry depth profiling of polymer materials with large Ar cluster ion beams
Authors: Ninomiya Satoshi , Ichiki Kazuya , Yamada Hideaki , Nakata Yoshihiko , Seki Toshio , Aoki Takaaki , Matsuo Jiro
Published: April 2009

We demonstrate depth profiling of polymer materials by using large argon (Ar) cluster ion beams. In general, depth profiling with secondary ion mass spectrometry (SIMS) presents serious problems in organic materials, because the primary keV atomic ion beams often damage them and the molecular ion yields decrease with increasing incident ion fluence. Recently, we have found reduced damage of organic materials during sputtering with large gas cluster ions, and reported on the unique secondary ion emission of organic materials. Secondary ions from the polymer films were measured with a linear type time‐of‐flight (TOF) technique; the films were also etched with large Ar cluster ion beams. The mean cluster size of the primary ion beams was Ar700 and incident energy was 5.5 keV. Although the primary ion fluence exceeded the static SIMS limit, the molecular ion intensities from the polymer films remained constant, indicating that irradiation with large Ar cluster ion beams rarely leads to damage accumulation on the surface of the films, and this characteristic is excellently suitable for SIMS depth profiling of organic materials. Copyright © 2009 John Wiley & Sons, Ltd.
Beginning teachers moving toward effective elementary science teaching
Authors: Davis Elizabeth A. , Smithey Julie
Published: April 2009

We use a 10‐year program of research centered on iterations of one elementary science methods course as a vehicle for exploring three important and interrelated goals for the learning of beginning elementary teachers. These include learning about inquiry‐oriented science teaching, using science curriculum materials effectively, and anticipating and working with students' ideas in instruction. For each goal we discuss how the literature informs our thinking, describe relevant aspects of our design of the course, and present findings of our research with regard to preservice teachers' experiences in and learning from aspects of the course. For each goal, we also highlight examples from our longitudinal work following the preservice teachers into their early years as elementary teachers, to provide a glimpse of teachers' trajectories related to each of the themes. We close with a discussion of implications for research and practice in elementary science teacher education. © 2009 Wiley Periodicals, Inc. Sci Ed 93:745–770, 2009
Principled reasoning about problems of practice
Authors: Mikeska Jamie N. , Anderson Charles W. , Schwarz Christina V.
Published: April 2009

The elementary science teacher educators in this article set recognize the challenges that new science teachers face when they enter classrooms. They have developed frameworks and strategies aimed at helping the preservice teachers with whom they work become “well‐started beginners” who are ready to address problems of science teaching. To do so, these educators purposefully engage the candidates in focused dialogue regarding challenges or problems of practice that they will likely face in their work. These challenges include (1) engaging in science, (2) organizing instruction, and (3) understanding students. The science teacher educators use a dialogic third space to help the preservice teachers reconsider and develop deeper understandings of these problems of practice. In this introduction, we point out some of the common themes that tie these articles together, including (a) a focus on problems of practice in elementary science teaching, (b) a focus on dialogue with preservice teachers about these problems of practice, (c) a commitment to developing tools and approaches that support principled reasoning about these problems of practice, and (d) a commitment to shared goals and methods for research on elementary science teacher education. We point to ways that these themes are addressed in the three articles. © 2009 Wiley Periodicals, Inc. Sci Ed 93:678–686, 2009
Developing preservice elementary teachers' knowledge and practices through modeling‐centered scientific inquiry
Authors: Schwarz Christina
Published: April 2009

Preservice elementary teachers face many challenges in learning how to teach science effectively, such as engaging students in science, organizing instruction, and developing a productive learning community. This paper reports on several iterative cycles of design‐based research aimed at fostering preservice teachers' principled reasoning around these problems of practice through modeling‐centered scientific inquiry. The first design cycle introduced preservice teachers to modeling and simulation software tools in an effort to advance their understanding of science and technology; the second used an instructional framework embodying modeling‐centered inquiry to advance their views of effective science teaching and their lesson‐planning practices; the third engaged preservice teachers in analyzing and modifying curriculum materials using reform‐based criteria to foster effective curriculum materials use. Outcomes from these iterations indicate that the preservice teachers were most likely to advance their knowledge and practices within a coherent approach that focused on a core scientific practice such as modeling‐centered inquiry, provided opportunities to unpack and apply robust tools such as reform‐based instructional frameworks, and addressed their perceived problems of practice. The findings from this set of approaches are compared to others in an effort to point toward promising future directions for effective science teacher education. © 2009 Wiley Periodicals, Inc. Sci Ed 93:720–744, 2009
Comparison of two parameter choice methods for the extraction of depth profiles by means of a regularized multipoint profile model from ARXPS data obtained on a three‐component system
Authors: Paynter R. W.
Published: April 2009

Polystyrene films were exposed to nitrogen plasmas for periods up to 8 min. Angle‐resolved X‐ray photoelectron spectroscopy measurements revealed the presence of oxygen and nitrogen in the surface due to the plasma treatment. The depth profiles of these adatoms were determined by fitting a regularized multipoint linear segment model to the data. A regularization parameter chosen such that the chi‐square statistic of the fit to the data was equal to the number of independent data points gave a more intuitive result than a parameter chosen according to the L‐curve criterion. Although the shape of the nitrogen depth profile was observed to vary as a function of the plasma duration, the oxygen depth profiles were nearly identical. Copyright © 2009 John Wiley & Sons, Ltd.
Amifostine protection against induced DNA damage in γ‐irradiated Escherichia coli cells depend on recN DNA repair gene product activity
Authors: Almeida Eliseo , Fuentes Jorge Luis , Cuetara Elizabeth , Prieto Elio , Llagostera Montserrat
Published: April 2009

Amifostine is the most effective radioprotector known and the only one accepted for clinical use in cancer radiotherapy. In this work, the antigenotoxic effect of amifostine against γ‐rays was studied in Escherichia coli cells deficient in DNA damage repair activities. Assays of irradiated cells treated with amifostine showed that the drug reduced the genotoxicity induced by radiation in E. coli wild‐type genotypes and in uvr, recF, recB, recB‐recC‐recF mutant strains, but not in recN defective cells. Thus, the mechanism of DNA protection by amifostine against γ‐radiation‐induced genotoxicity appears to involve participation of the RecN protein that facilitates repair of DNA double‐strand breaks. The results are discussed in relation to amifostine's chemopreventive potential. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010.
Accumulation of toxic metals (Pb and Cd) in the sea urchin Diadema aff. antillarum Philippi, 1845, in an oceanic island (Tenerife, Canary Islands)
Authors: Hernández Ofelia Dolores , Gutiérrez Ángel José , González‐Weller Dailos , Lozano Gonzalo , Melón Enrique García , Rubio Carmen , Hardisson Arturo
Published: April 2009

This document shows the results obtained from a study on the concentration of toxic heavy metals in the internal tissue and exoskeleton of sea urchins, collected from their natural habitat. The levels of lead and cadmium were measured by Graphite Furnace Atomic Absorption Spectrometry. The mean concentrations of lead and cadmium in the internal tissue were 304.04 and 260.54 μg/kg respectively, whereas in the shell they were 185.02 and 142.48 μg/kg. We also performed a statistical analysis of the differences in the distribution of metals between their exoskeleton and their internal content, a correlation study of the metal content in internal tissue and shell and sampling areas, and a correlation study between the metal content and sample size. Since the sea urchin Diadema antillarum presents a wide range of variation in metal content, this study suggests that this species is an excellent bioindicator of heavy metal contamination. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010.
Malathion‐induced oxidative stress, cytotoxicity, and genotoxicity in human liver carcinoma (HepG2) cells
Authors: Moore Pamela D. , Yedjou Clement G. , Tchounwou Paul B.
Published: April 2009

Malathion is an organophosphate pesticide that is known for its high toxicity to insects and low to moderate potency to humans and other mammals. Its toxicity has been associated with the inhibition of acetylcholinesterase activity, leading to the interference with the transmission of nerve impulse, accumulation of acetylcholine at synaptic junctions, and subsequent induction of adverse health effects including headache, dizziness, nausea, vomiting, bradycardia, and miosis. Oxidative stress (OS) has been reported as a possible mechanism of malathion toxicity in humans. Hence, the aim of this study was to examine the role of OS in malathion‐induced cytotoxicity and genotoxicity. To achieve this goal, MTT, lipid peroxidation, and single cell gel electrophoresis (Comet) assays were performed, respectively, to evaluate the levels of cell viability, malondialdehyde (MDA) production, and DNA damage in human liver carcinoma (HepG2) cells. Study results indicated that malathion is mitogenic at lower levels of exposure, and cytotoxic at higher levels of exposure. Upon 48 h of exposure, the average percentages of cell viability were 100% ± 11%, 117% ± 15%, 86% ± 15%, 35% ± 9%, and 27% ± 7% for 0, 6, 12, 18, and 24 mM, respectively. In the lipid peroxidation assay, the concentrations of MDA produced were 12.55 ± 0.16, 20.65 ± 0.27, 31.1 ± 0.40, 34.75 ± 0.45, and 15.1 ± 0.20 μM in 0, 6, 12, 18, and 24 mM malathion, respectively. The Comet assay showed a significant increase in DNA damage at the 24 mM malathion exposure. Taken together, our results indicate that malathion exposure at higher concentrations induces cytotoxic and genotoxic effects in HepG2 cells, and its toxicity may be mediated through OS as evidenced by a significant production of MDA, an end product of lipid peroxidation. © 2009 Wiley Periodicals, Inc. Environ Toxicol 2010.
Investigation of the dynamic mechanical behavior of polypropylene/(wood flour)/(kenaf fiber) hybrid composites
Authors: Ghasemi Ismail , Azizi Hamed , Naeimian Navid
Published: April 2009

Polypropylene/(wood flour)/(kenaf fiber) hybrid composites were prepared in an internal mixer. Kenaf was considered as a fibrous filler and wood flour as a particulate filler. The lignocellulosic loading used was 50%. Dynamic mechanical thermal analysis properties such as storage modulus (E′), loss modulus (E″), damping factor (tan δ), and adhesion factor were evaluated. It was found that the adhesion factor could interpret the interfacial adhesion between lignocellulosic fillers and the plastic matrix macroscopically. This factor was affected by the type of filler used and the coupling agent concentration. The variation of storage modulus was affected more by the shape of the filler and the coupling agent concentration at higher temperatures than at temperatures below the glass transition. Owing to a higher probability of agglomeration in a sample containing 50 wt% of wood flour, the storage modulus and complex viscosity of this sample were higher than those of other samples. Cole‐Cole diagrams showed that the homogeneity of samples containing a higher amount of coupling agent was higher than that of samples with a lower concentration. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers
Effects of nanoclay and additives on the fusion characteristics and thermal stability of poly(vinyl chloride) nanocompounds
Authors: Moghri Mehdi , Akbarian Masis
Published: April 2009

The effects of varying amounts of organically modified nanoclay (NC), calcium stearate (Ca.St.), stearic acid (St.Ac.), and an impact modifier (IM) on the fusion characteristics of a rigid Poly(vinyl chloride) (PVC) nanocompound were investigated by using the L9 orthogonal method of experimental design. The materials showed varying effects on the fusion parameters. Thus, while the fusion time was lowered and the fusion factor increased by NC, Ca.St., and IM, the reverse was true with St.Ac. Effects on the minimum and maximum viscosities of formulations also varied with material type. The behavior of the materials is discussed in terms of their effects on the transformation of PVC grains. Thermal stability and color change were sensitive to NC content. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers
The first weekend of spring
Authors: Prichard Bob
Published: April 2009

This Weather Image describes how the first weekend of Spring 2009 brought heavy rain and wintry showers to the British Isles, and illustrates the weather pattern responsible with satellite and radar images. Copyright © 2009 Royal Meteorological Society
Incidence, clinical presentation and pathological features of benign sclerosing cholangitis of unknown origin masquerading as biliary carcinoma
Authors: Fujita Takeo , Kojima Motohiro , Gotohda Naoto , Takahashi Shinichiro , Nakagohri Toshio , Konishi Masaru , Ochiai Atsushi , Kinoshita Taira
Published: April 2009

Background

Benign obstructions of the liver hilum are occasionally encountered in surgically resected cases. Some of these cases are pathologically classified as benign sclerosing cholangitis and are not clearly categorized. This study aims to elucidate the clinicopathological features of benign sclerosing cholangitis of unknown origin.

Methods

Patients who had undergone surgery of the proximal bile duct from 1993 to 2008 on suspicion of proximal bile carcinoma were evaluated, then their clinical presentation, histopathological and immunohistochemical findings were retrospectively analyzed.

Results

One hundred seventy‐six patients underwent surgery during this period. Of these, five patients were diagnosed with benign sclerosing cholangitis of unknown origin. All five patients were middle‐aged with no history of autoimmune disease. One patient died of recurrent cholangitis after surgery. Histopathologically, lymphoplasmacytic infiltrations were observed in all five cases. Among them, the clinicopathological findings of one patient were compatible with IgG4‐related sclerosing cholangitis, and the other two patients had unusual histopathological findings with prominent lymph follicular formation.

Conclusions

Although patients with benign sclerosing cholangitis of unknown origin comprise a heterogeneous population, they can be further classified into subgroups. The response to immunosuppressive therapy, long‐term prognosis and histological morphology of the disease should be considered in order to classify these cases of sclerosing cholangitis.
Clustering Qualitative Data Based on Binary Equivalence Relations: Neighborhood Search Heuristics for the Clique Partitioning Problem
Authors: Brusco Michael J. , Köhn Hans-Friedrich
Published: April 2009

The clique partitioning problem (CPP) requires the establishment of an equivalence relation for the vertices of a graph such that the sum of the edge costs associated with the relation is minimized. The CPP has important applications for the social sciences because it provides a framework for clustering objects measured on a collection of nominal or ordinal attributes. In such instances, the CPP incorporates edge costs obtained from an aggregation of binary equivalence relations among the attributes. We review existing theory and methods for the CPP and propose two versions of a new neighborhood search algorithm for efficient solution. The first version (NS-R) uses a relocation algorithm in the search for improved solutions, whereas the second (NS-TS) uses an embedded tabu search routine. The new algorithms are compared to simulated annealing (SA) and tabu search (TS) algorithms from the CPP literature. Although the heuristics yielded comparable results for some test problems, the neighborhood search algorithms generally yielded the best performances for large and difficult instances of the CPP.
Effect of the Presence and Absence of Potatoes under Repeated Frying Conditions on the Composition of Palm Oil
Authors: Kalogianni Eleni P. , Karastogiannidou Calliope , Karapantsios Thodoris D.
Published: April 2009

The effect of repeated deep frying of potatoes versus repeated heating/quenching on the chemical profile of palm oil was investigated. The novelty of the work is that the frying and heating/quenching experiments were conducted under similar time‐temperature profiles. The effects of the frying load (potato‐to‐oil ratio: 1/7 and 1/35 kgpotatoes/loil) and of the time‐temperature profile were examined. Whole palm oil and its polar fraction were analyzed using high pressure size exclusion chromatography. Both repeated frying and repeated heating/quenching generated polar and polymerization products in palm oil. Interestingly, no hydrolysis or other decomposition products were generated under any of the examined conditions. The presence of potatoes during frying in palm oil increased the concentration of polymerization products and polar compounds compared to oils without potatoes significantly. The effects of frying load on oil quality depended on frying time. No significant effect of frying load was observed up to frying times of 13 h (or 10 frying batches). However, frying oil quality was affected by frying load once frying times exceeded 24 h (or 20 batches).
Urinary Peptidomic Analysis Identifies Potential Biomarkers for Acute Rejection of Renal Transplantation
Authors: Sigdel Tara K. , Ling Xuefeng B. , Lau Ken H. , Li Li , Schilling James , Sarwal Minnie M.
Published: April 2009

Introduction

Human urine is a complex matrix of proteins, endogenous peptides, lipids, and metabolites. The level of any or all of these components can reflect the pathophysiological status of an individual especially of the kidney at the time of urine collection. The naturally occurring endogenous urinary peptides which are thought to be the product of several proteolytic and degradation processes may provide clinically useful biomarkers for different renal and systemic diseases.

Materials and Methods

To examine if specific differences in the urinary peptidome (<10 kDa) occur at the time of acute renal transplant rejection (AR), we undertook a study of urine samples collected from biopsy-proven AR (n = 10), stable graft function (n = 10), and healthy normal control (n = 10). The peptides (<10 kDa) were extracted and fractionated with high-performance liquid chromatography followed by matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometric (MS) analysis.

Results

We identified 54 endogenous peptides, including multiple peptides for Tamm–Horsfall protein (UMOD). A panel of peptides are identified which discriminate renal transplant patients with AR from stable graft. We have shown that liquid chromatography followed by MALDI is a useful tool to identify potential biomarkers, which after verification with larger patient cohort can be used as a non-invasive monitoring tool for renal transplant rejection.