bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of immobilized polypeptides with different C‐terminal residues using argon gas‐cluster SIMS
Authors: Aoyagi Satoka , Moritani Kousuke , Mochiji Kozo 
Published: June 2010

AbstractGas cluster (GC) ion sources, such as an argon cluster source, have been employed in SIMS of organic or biomaterials due to their low‐energy projectile effect. Recently, it was found that GC‐SIMS reportedly provides intact ion detection of proteins with molecular weights of 10000 or higher. Since GC‐SIMS enables control of the gas cluster size and collision energy per atom, it is considered sensitive for the detection of very small differences in the monolayers of polypeptides such as leu‐enkephalin (H‐Tyr‐Gly‐Gly‐Phe‐Leu‐OH) and met‐enkephalin (H‐Tyr‐Gly‐Gly‐Phe‐Met‐OH). In this study, both enkephalins were measured with GC‐SIMS and their spectra were compared to evaluate GC‐SIMS sensitivity to small chemical structure differences. The polypeptides, leu‐enkephalin and met‐enkephalin, were immobilized on indium‐ and tin oxide (ITO)‐coated glass plates, respectively, by binding their N terminal residues to glutaraldehyde‐activated aminosilanized‐ITO plates. An aminosilanized‐ITO plate without polypeptide was also prepared as the control sample. After freeze‐drying, the samples were measured with TOF‐SIMS with the argon cluster ion source, and then TOF‐SIMS spectra were analyzed to select peaks specific to the polypeptides. As a result, fragment ions related to the polypeptide without recombination were detected using the argon GC‐SIMS. Copyright © 2010 John Wiley & Sons, Ltd.
Visualization of biomolecules in the eyestalk of the blue swimming crab, Portunus pelagicus, by imaging mass spectrometry using the atmospheric‐pressure mass microscope
Authors: Sroyraya Morakot , Goto‐Inoue Naoko , Zaima Nobuhiro , Hayasaka Takahiro , Chansela Piyachat , Tanasawet Supita , Shrivas Kamlesh , Sobhon Prasert , Setou Mitsutoshi 
Published: June 2010

AbstractWe have developed an imaging mass spectrometer—the atmospheric‐pressure mass microscope—with high spatial resolution, which is composed of an atmospheric pressure ion‐source chamber for matrix‐assisted laser desorption/ionization (AP‐MALDI) and a quadrupole ion trap time‐of‐flight (QIT‐TOF) mass spectrometer. The production of 2‐dimensional mass spectrum intensity by the atmospheric‐pressure mass microscope with a very fine scan pitch enables us to visualize the distribution of lipids and their metabolites in frozen sections without any specific probes or labels.In this study, we applied AP‐MALDI‐QIT‐TOF imaging mass spectrometry to investigate the distribution of lipids in the compound eye‐associated eyestalk of the blue swimming crab, Portunus pelagicus. The eyestalk of crustaceans responds to many signaling substances, and most of these substances are involved in lipid metabolism. The merged ion image of five significant biomolecules clearly showed seven separate zones in the eye and eyestalk. The results indicate that the lipid components of each cell layer of the compound eye are different. This study provides information regarding lipid compositions and locations on real tissue that correlate with function. Imaging mass spectrometry (IMS) with high spatial resolution could thus be a powerful tool for imaging and measurement of various samples for a first molecular screening. Copyright © 2010 John Wiley & Sons, Ltd.
The National Children's Study (NCS): Establishment and protection of the inferential base
Authors: Ellenberg Jonas H. 
Published: June 2010

AbstractThe National Children's Study (NCS) is a unique study of environment and health that will follow a cohort of 100 000 women from prior to or early in pregnancy and then their children until 21 years of age. The NCS cohort will be a national multi‐stage probability sample, using a U.S. Census Bureau geographic sampling frame unrelated to factors that might influence selection into the sample (e.g. access to health care). I present the case for the use of a national probability sample as the design base for the NCS, arguing that selection of the original cohort should be as free from selection bias as possible. The dangers of using a selected or nonprobability sample approach are demonstrated by an example of its use in outlining the clinical management of children with febrile seizures, an infrequent disorder, which was so wrong for decades. In addition, I stress the importance of and the NCS approach to avoiding selection bias that might occur after the initial selection of the cohort. The selection of and maintenance of an unselected cohort is an important element for the validity of inferences in this major undertaking. Copyright © 2010 John Wiley & Sons, Ltd.
Statistical and practical issues in the design of a national probability sample of births for the Vanguard Study of the National Children's Study
Authors: Montaquila Jill M. , Brick J. Michael , Curtin Lester R. 
Published: June 2010

AbstractThe National Children's Study is a national household probability sample designed to identify 100 000 children at birth and follow the sampled children for 21 years. Data from the study will support examining numerous hypotheses concerning genetic and environmental effects on the health and development of children. The goals of the study present substantial challenges. For example, the need for preconception, prenatal, and postnatal data requires identifying women in the early stages of pregnancy, the collection of many types of data, and the retention of the children over time. In this paper, we give an overview of the sample design used in a pilot study called the Vanguard Study, and highlight the approaches used to address these challenges. We will also describe the rationale for the sampling choices made at each stage, the unique organizational structure of the NCS and issues we expect to face during implementation. Published in 2010 by John Wiley & Sons, Ltd.
Improving cost‐effectiveness of epidemiological studies via designed missingness strategies
Authors: Strauss Warren J. , Ryan Louise , Morara Michele , Iroz‐Elardo Nicole , Davis Mark , Cupp Matthew , Nishioka Marcia G. , Quackenboss James , Galke Warren , Özkaynak Haluk , Scheidt Peter 
Published: June 2010

AbstractModern epidemiological studies face opportunities and challenges posed by an ever‐expanding capacity to measure a wide range of environmental exposures, along with sophisticated biomarkers of exposure and response at the individual level. The challenge of deciding what to measure is further complicated for longitudinal studies, where logistical and cost constraints preclude the collection of all possible measurements on all participants at every follow‐up time. This is true for the National Children's Study (NCS), a large‐scale longitudinal study that will enroll women both prior to conception and during pregnancy and collect information on their environment, their pregnancies, and their children's development through early adulthood—with a goal of assessing key exposure/outcome relationships among a cohort of approximately 100 000 children. The success of the NCS will significantly depend on the accurate, yet cost‐effective, characterization of environmental exposures thought to be related to the health outcomes of interest. The purpose of this paper is to explore the use of cost saving, yet valid and adequately powered statistical approaches for gathering exposure information within epidemiological cohort studies. The proposed approach involves the collection of detailed exposure assessment information on a specially selected subset of the study population, and collection of less‐costly, and presumably less‐detailed and less‐burdensome, surrogate measures across the entire cohort. We show that large‐scale efficiency in costs and burden may be achieved without making substantive sacrifices on the ability to draw reliable inferences concerning the relationship between exposure and health outcome. Several detailed scenarios are provided that document how the targeted sub‐sampling design strategy can benefit large cohort studies like the NCS, as well as other more focused environmental epidemiologic studies. Published in 2010 by John Wiley & Sons, Ltd.
Nanoparticle‐Induced Folding and Fibril Formation of Coiled‐Coil‐Based Model Peptides
Authors: Wagner Sara C. , Roskamp Meike , Pallerla Manjula , Araghi Raheleh Rezaei , Schlecht Sabine , Koksch Beate 
Published: June 2010

AbstractNanomedicine is a rapidly growing field that has the potential to deliver treatments for many illnesses. However, relatively little is known about the biological risks of nanoparticles. Some studies have shown that nanoparticles can have an impact on the aggregation properties of proteins, including fibril formation. Moreover, these studies also show that the capacity of nanoscale objects to induce or prevent misfolding of the proteins strongly depends on the primary structure of the protein. Herein, light is shed on the role of the peptide primary structure in directing nanoparticle‐induced misfolding by means of two model peptides. The design of these peptides is based on the α‐helical coiled‐coil folding motif, but also includes features that enable them to respond to pH changes, thus allowing pH‐dependent β‐sheet formation. Previous studies showed that the two peptides differ in the pH range required for β‐sheet folding. Time‐dependent circular dichroism spectroscopy and transmission electron microscopy are used to characterize peptide folding and aggregate morphology in the presence of negatively charged gold nanoparticles (AuNPs). Both peptides are found to undergo nanoparticle‐induced fibril formation. The determination of binding parameters by isothermal titration calorimetry further reveals that the different propensities of both peptides to form amyloid‐like structures in the presence of AuNPs is primarily due to the binding stoichiometry to the AuNPs. Modification of one of the peptide sequences shows that AuNP‐induced β‐sheet formation is related to the structural propensity of the primary structure and is not a generic feature of peptide sequences with a sufficiently high binding stoichiometry to the nanoparticles.
Cellular Association and Assembly of a Multistage Delivery System
Authors: Serda Rita E. , Mack Aaron , Pulikkathara Merlyn , Zaske Ana Maria , Chiappini Ciro , Fakhoury Jean R. , Webb Douglas , Godin Biana , Conyers Jodie L. , Liu Xue W. , Bankson James A. , Ferrari Mauro 
Published: June 2010

AbstractThe realization that blood‐borne delivery systems must overcome a multiplicity of biological barriers has led to the fabrication of a multistage delivery system (MDS) designed to temporally release successive stages of particles or agents to conquer sequential barriers, with the goal of enhancing delivery of therapeutic and diagnostic agents to the target site. In its simplest form, the MDS comprises stage‐one porous silicon microparticles that function as carriers of second‐stage nanoparticles. Cellular uptake of nontargeted discoidal silicon microparticles by macrophages is confirmed by electron and atomic force microscopy (AFM). Using superparamagnetic iron oxide nanoparticles (SPIONs) as a model of secondary nanoparticles, successful loading of the porous matrix of silicon microparticles is achieved, and retention of the nanoparticles is enhanced by aminosilylation of the loaded microparticles with 3‐aminopropyltriethoxysilane. The impact of silane concentration and reaction time on the nature of the silane polymer on porous silicon is investigated by AFM and X‐ray photoelectron microscopy. Tissue samples from mice intravenously administered the MDS support co‐localization of silicon microparticles and SPIONs across various tissues with enhanced SPION release in spleen, compared to liver and lungs, and enhanced retention of SPIONs following silane capping of the MDS. Phantom models of the SPION‐loaded MDS display negative contrast in magnetic resonance images. In addition to forming a cap over the silicon pores, the silane polymer provides free amines for antibody conjugation to the microparticles, with both VEGFR‐2‐ and PECAM‐specific antibodies leading to enhanced endothelial association. This study demonstrates the assembly and cellular association of a multiparticle delivery system that is biomolecularly targeted and has potential for applications in biological imaging.
Enzyme digestibility and acid/shear stability of heat–moisture treated canna starch
Authors: Watcharatewinkul Yanika , Uttapap Dudsadee , Puttanlek Chureerat , Rungsardthong Vilai 
Published: June 2010

AbstractThe stability of heat–moisture treated (HMT) canna starches (starches with moisture contents of 15, 18, 20, 22, and 25%, treated at 100°C for 16 h) against acid, high shearing forces, and enzyme digestion was investigated. Micrographs of starch gels taken from a Rapid Visco Analyzer showed that granules of untreated native starch subjected to pH values of 7.2 and 4.6 were highly swelled, whereas granules exposed to higher acidic pH (3.0) values fragmented into small pieces. Yet, less swelling was found for the HTN15%, HMT18%, and HMT20% samples. Even at pH 3.0, HMT22% and HMT25% granules were still in an intact granular form. Similar findings were observed when native and HMT canna starches were agitated at various rates (160, 240, 320, and 480 rpm). Starch samples treated under higher moisture levels exhibited a higher tolerance to shearing forces acting on them. Comparative investigation of HMT and chemically crosslinked starches showed that pasting properties of HMT22% and HMT25% were equivalent to those of canna starches crosslinked by sodium trimetaphosphate at 0.2 and 0.5% (dwb), respectively. In regards to the enzyme digestibility of treated canna starches, there was no recognizable trend. The extent of starch hydrolysis (at 24 h) as a function of moisture level during HMT conformed to the following order: HMT25% > HTN15% > HMT18% ≈ native > HMT20% > HMT22%.
Analytic wavelet transformation‐based modal parameter identification from ambient responses
Authors: Li Chunxiang , Shen Jianhong 
Published: June 2010

AbstractAnalytic wavelet transform (AWT) based on Gabor wavelet function overcomes the deficiency of the time‐domain localization of traditional Fourier transform and the limitation of the constant resolution in the time‐frequency domain of short‐time Fourier transform. The identification of modal parameters of structures may be carried out by both the amplitude and phase frequency information revealed by resorting to matching mechanism between the wavelet function and complex‐valued signal. By applying the AWT in conjunction with the well‐known random decrement technique, this paper analyses the time‐frequency resolution of Gabor wavelet and the process of identifying structural modal parameters. The method of selecting the parameters of Gabor wavelet function and the formula determining the usable lengths of signal are thus proposed. Eventually, the efficiency of the present method is confirmed by applying it to a numerical simulation data without and with noise contamination of a three degree‐of‐freedom (3DOF) structure with the closely spaced natural frequencies and to ambient vibration full‐scale measurements of a super high‐rise building—Shanghai Jin Mao Building excited by wind. Copyright © 2010 John Wiley & Sons, Ltd.
Ionengetterpumpen
Authors: Thierley Marcus 
Published: June 2010

AbstractIonengetterpumpen werden nicht nur durch ihr nominelles Saugvermögen charakterisiert. Sehr großen Einfluss auf das Pumpverhalten für verschiedene Gase haben die eingesetzten Pumpelemente. Heute hat der Anwender die Qual der Wahl, da es verschiedene Pumpelemente auf dem Markt gibt. Dieser Artikel soll dabei helfen, die passende Pumpe für die vorgesehene Applikation auszuwählen.
Membranvakuumpumpen als Turbo‐Vorpumpen
Authors: Dirscherl Jürgen 
Published: June 2010

AbstractModerne Turbopumpen mit integrierter Molekularpumpstufe können mit einem Vorvakuum im mbar‐Bereich betrieben werden. Als Vorpumpe können daher vorteilhaft ölfreie Membranvakuumpumpen eingesetzt werden. Große Fortschritte bei der Membrantechnologie durch den Einsatz optimierter Flachmembrane sowie durch elektronisch gesteuerte Antriebssysteme machen Membranpumpen noch kompakter, leistungsfähiger und zuverlässiger. Über fünf Jahre laufende Dauertests an Membranvakuumpumpen mit kontinuierlicher Endvakuummessung zeigen Membranlebensdauern von über 40.000 Stunden, und dies bei konstant sehr gutem Endvakuum. Insbesondere bei drehzahlgeregelten Systemen sind damit Wartungsintervalle ähnlich denen von Turbopumpen mittlerweile realisierbar.
Simulation von Plasma‐Beschichtungsprozessen
Authors: Pflug Andreas , Siemers Michael , Schwanke Christoph , Szyszka Bernd 
Published: June 2010

AbstractAufgrund der fortschreitenden Hochskalierung industrieller Plasma‐Beschichtungsprozesse steigen die Anforderungen sowohl an Produktivität als auch an Präzision kontinuierlich. Beide Anforderungen sind gegensätzlich, so wird z. B. eine Produktivitätssteigerung oft mittels Vergrößerung der Substratmaße erzielt, hierdurch wird i. d. R. die Homogenität der Schichteigenschaften über die Substratfläche verschlechtert.Eine auf experimentellen Methoden fußende Weiterentwicklung von Beschichtungsquellen wird durch die zunehmende Komplexität und Größe der Beschichtungsanlagen erschwert. Aus diesem Grund wird in der Forschung und Entwicklung in der Beschichtungstechnologie in letzter Zeit zunehmend ein Schwerpunkt auf Simulationsverfahren gesetzt.Am Fraunhofer‐Institut für Schicht und Oberflächentechnik wurde eine Particle‐in‐Cell Monte‐Carlo – Simulationsumgebung implementiert, um Transportphänomene und Gasentladungen im Niederdruckbereich detailliert beschreiben zu können. Bei der Entwicklung neuer Plasma‐Beschichtungsquellen können mit diesem Simulationstool Vorhersagen und Optimierungen durchgeführt sowie allgemein das Verständnis der Plasmaentladungsmechanismen vertieft werden.
Sputteryield‐Amplification
Authors: Szyszka Bernd , Pflug Andreas , Sittinger Volker , Ulrich Stephan 
Published: June 2010

AbstractDie Erhöhung der Sputterrate durch den Sputteryield‐Amplification‐Effekt zeigt Potential auf, um die Energieeffizienz von Sputterprozessen deutlich zu steigern. Seit der Entdeckung dieses Effekts in den 1990er Jahren wurden vornehmlich metallische Prozesse untersucht. Rechnungen und erste Experimente zeigen jedoch gerade für das Sputtern von keramischen Targets interessante möglichkeiten zur Ratensteigerung. Nachfolgend werden der Stand der Technik und die zu erwartenden Ergebnisse als Übersicht zusammengestellt.
Formation of an Inorganic‐Organic Host‐Guest Material by Intercalation of Acetone Formaldehyde Sulfite Polycondensate into a Hydrocalumite Structure
Authors: Plank Johann , von Hoessle Friedrich 
Published: June 2010

AbstractAn acetone formaldehyde sulfite based polycondensate (Mw ~ 64 kDa), which is commonly used as a superplasticizer in cement and concrete, was intercalated into a hydrocalumite type LDH structure. Preparation was done by controlled rehydration of tricalcium aluminate in the presence of the polymer. Formation of the LDH phase was confirmed by XRD, IR spectroscopic and TG measurements. Elemental composition of the organo‐mineral phase reveals charge balancing of the cationic LDH main layers by the polycondensate and OH– ions. Low crystallinity observed by XRD and presence of LDH foils was verified by SEM images. There, the novel Ca‐Al‐LDH phase shows a morphology of intergrown platelets which is typical for layered calcium aluminate hydrates. Depending on the preparation method, ultra‐thin foils with 20 nm–50 nm thickness were observed. TEM images also support presence of a layered structure.
Self‐assembled Monolayers of Alkylphosphonic Acids on Aluminum Oxide Surfaces – A Theoretical Study
Authors: Luschtinetz Regina , Oliveira Augusto F. , Duarte Hélio A. , Seifert Gotthard 
Published: June 2010

AbstractDensity‐functional based calculations were used to investigate self‐assembled monolayers of different alkylphosphonic acids on corundum α‐Al2O3 (0001), bayerite β‐Al(OH)3 (001) and boehmite γ‐AlOOH (010) surface models. Mono‐, bi‐, and tridentate adsorption modes were considered. In addition, the organization of single adsorbed molecules was compared to the organization at full surface coverage. The height (thickness) of the self‐assembled monolayers is always shorter than the length of the phosphonic acid molecules due to tilting of the alkyl chains. Tilt angles at full surface coverage are very similar to the tilt angle of a single adsorbed molecule, which indicates that the density of the self‐assembled monolayers is limited by the density of adsorption sites. The lateral interactions between alkyl chains are evidenced by small torsions of the adsorbed molecules, which may serve to minimize the repulsion forces between interchain hydrogen atoms. Similar tilt angles were obtained for mono‐, bi‐, and tridentate adsorptions. Hence, the coordination mode cannot be characterized by the molecule tilting.
Synthesis, Spectroscopic, and Electrochemical Properties of Four Novel Trinuclear RuII Polypyridyl Complexes Containing Diazafluorene
Authors: Cheng Feixiang , Wang Fan , Yang Siya , Tang Ning , Chen Longhai 
Published: June 2010

AbstractFour tripodal ligands L1–4 derived from 4,5‐diazafluoren‐9‐one were synthesized. L1–2 formed by the reaction of 4,5‐diazafluoren‐9‐oxime with 1,3,5‐tris(bromomethyl)benzene, and 1,1,1‐tris(p‐tosyloxymethyl)propane, respectively and L3–4 formed by the condensation of 9‐(4‐hydroxy)phenylimino‐4,5‐diazafluorene with 1,3,5‐tris(bromomethyl)benzene, and 1,1,1‐tris(p‐tosyloxymethyl)propane, respectively. Four trinuclear complexes [(bpy)6Ru3L1–4](PF6)6 (Ru‐L1–4) were obtained by reaction of Ru(bpy)2Cl2·2H2O with ligands L1–4. The photophysical behaviors of these complexes were investigated by UV/Vis absorption and emission spectrometry. The complexes display metal‐to‐ligand charge transfer absorptions at 441–445 nm and emissions at 571–578 nm. Cyclic voltammetry data of the complexes show one RuII‐centered oxidation and three successive ligand‐centered reductions.