bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prävention und Therapie der Osteoporose. Stellenwert von Calcium und Vitamin D
Authors: Bartl Reiner 
Published: April 2009

AbstractEine 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

AbstractNahrungsergänzungsmittel 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

AbstractA 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

AbstractObjectiveNonvisualization 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.MethodA 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.ResultsA 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.ConclusionGGT 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

AbstractTwo 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

AbstractA 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

AbstractA 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

AbstractIn 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

AbstractMit 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

AbstractWir 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

AbstractEr 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

AbstractEiskonfekt 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

AbstractWe 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

AbstractHybrid 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

AbstractBACKGROUNDInteractions 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.METHODSTumor 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.RESULTSThe 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.CONCLUSIONSThe 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

AbstractThe 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

AbstractHepatocellular 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

AbstractElectrospray 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.