bluuebunny/crossref_metadata_2025_split huggingface dataset:
Instability and Self‐Oscillations in the Cell Energy Metabolism
Authors: Sel'kov E. E. 
Published: December 2010

AbstractThe temporal organization of the cell energy metabolism is the only way of maintaining a stable ATP concentration within the cell. This type of organization results directly from allosteric regulations of the key futile cycles of the cell energy metabolism such as substrate inhibition and product activation. These regulations switch the antagonist enzymes of the futile cycles on and off reciprocally to suppress recycling via self‐oscillatory changes in the enzyme activities. The deposition effect (E. E. Sel'kov, in: 8th FEBS Meeting, Vol. 25, pp. 145–161, H. C. Hemker and B. Hess, eds., North‐Holland, Amsterdam 1972) allows the oscillations on a circadian time scale.
Preclinical pharmacokinetics and metabolism of MNP001, a piperidine analog of 3‐carbamyl compounds
Authors: Xia Binfeng , Wang Desuo , Fox Laura M. 
Published: December 2010

AbstractMNP001 is a newly synthesized 3‐carbamyl‐4‐methylpyrrole analog with dual pharmacophores simultaneously to inhibit phosphodiesterase type 4 (PDE4) and to antagonize L‐type calcium channels. The physicochemical properties of MNP001, including solubility, pKa, Log P, plasma protein binding and plasma/blood partitioning, were determined to support the pharmacokinetic characterization. The preclinical pharmacokinetic parameters were determined in anin vivorat model and the metabolic pathways of MNP001 were characterized by incubating the compoundin vitroin rat or human microsomes/supersomes cocktails. MNP001 was found to have a low solubility in simulated intestinal fluid but a high solubility in simulated gastric fluid. MNP001 is a highly lipophilic compound with a LogPvalue greater than 4. MNP001 was highly bound to the plasma protein and had an uneven partition between red blood cells and plasma. MNP001 exhibited a rapid absorption, broad distribution, slow systemic clearance and a low but pharmacologically relevant oral bioavailability in rats. The low oral bioavailability was possibly caused by the low aqueous solubility of MNP001 in the gastrointestinal tract. However, 8 h after oral dosing, the mean plasma level of MNP001 was able to remain about 2‐fold greater than the minimum effective concentration. The major metabolite of MNP001 was defined as a tetrahydropyridine product (MNP001‐M4) of CYP3A4‐mediated phase I oxidation. The possibility that the major metabolite MNP001‐M4 may have a comparable antihypertensive efficacy to MNP001 needs to be studied. Copyright © 2010 John Wiley & Sons, Ltd.
Smoking, the xenobiotic pathway, and clubfoot
Authors: Sommer Amy , Blanton Susan H. , Weymouth Katelyn , Alvarez Christine , Richards B. Stephen , Barnes Douglas , Hecht Jacqueline T. 
Published: December 2010

AbstractBACKGROUNDIsolated clubfoot is a common orthopedic birth defect that affects approximately 135,000 newborns worldwide. It is characterized by ankle equinus, hindfoot varus, and forefoot adductus. Although numerous studies suggest a multifactorial etiology, the specific genetic and environmental components have yet to be delineated. Maternal smoking during pregnancy is the only common environmental factor consistently shown to increase the risk for clubfoot. Moreover, a positive family history of clubfoot, in conjunction with maternal smoking, increases the risk 20‐fold. These findings suggest that genetic variation in smoking metabolism (xenobiotic) genes may increase susceptibility to clubfoot. Based on this reasoning, we interrogated eight candidate genes from the xenobiotic metabolism.METHODSTwenty‐two single‐nucleotide polymorphisms and two null alleles in these genes (CYP1A1, CYP1A2, CYP1B1, CYP2A6, EPHX1, NAT2, GSTM1, and GSTT1) were genotyped in a dataset composed of non‐Hispanic white and Hispanic multiplex and simplex families.RESULTSOnly rs1048943/CYP1A1 had significantly altered transmission in the aggregate and multiplex non‐Hispanic white datasets (p = 0.003 and p = 0.009, respectively). Perturbation of CYP1A1 can cause an increase in harmful, adduct‐forming metabolic intermediates. A significant interaction between EPHX1 and NAT2 was also found (p = 0.007). Importantly, for CYP1A2, significant maternal (p = 0.03; relative risk [RR] = 1.24; 95% confidence interval [CI], 1.04–1.44) and fetal (p = 0.01; RR = 1.33; 95% CI, 1.13–1.54) genotypic effects were identified, suggesting that both maternal and fetal genotypes can negatively impact limb development. No association was found between maternal smoking status and variation in xenobiotic metabolism genes.CONCLUSIONTogether, these results suggest that xenobiotic metabolism genes are unlikely to play a major role in clubfoot; however, perturbation of this pathway may still play a contributory role. Birth Defects Research (Part A), 2011. © 2010 Wiley‐Liss, Inc.
NAT1,NOS3, and TYMS genotypes and the risk of conotruncal cardiac defects
Authors: Lupo Philip J. , Mitchell Laura E. , Goldmuntz Elizabeth 
Published: December 2010

AbstractBACKGROUNDAlthough congenital heart defects (CHDs) are a common and serious group of birth defects, relatively little is known about the causes of these conditions, and there are no established prevention strategies. There is, however, evidence suggesting that the risk of CHDs in general, and conotruncal and related defects (CTRDs) in particular, may be associated with maternal folate status and genetic variants of folate‐related genes. Although several folate‐related genes have been studied as they relate to CHDs and CTRDs (e.g., MTHFR), others have not been adequately assessed.METHODSCase‐parent triads were examined using log‐linear analyses to assess the associations between CTRDs and both the genotype inherited by the case and the maternal genotype for the following variants: NAT1 1095C>A, NOS3 894G>T, and TYMS 1494del6. Subgroup analyses were also conducted among cases with classic conotruncal defects and cases with normally related great arteries.RESULTSThe results provided little evidence that CTRD risk was associated with the genotype inherited by the case for any of the analyzed variants. However, our results suggest that CTRD risk may be associated with the maternal genotype for NOS3 894G>T (p = 0.024 in the subgroup with normally related great arteries) and TYMS 1494del6 (p = 0.048 in the subgroup with classicconotruncal defects). However, these results were not significant after correcting for multiple comparisons.CONCLUSIONThis study provides further evidence that CTRD risk may be related to variation within folate‐pathway genes and suggests that these associations are, at least in part, mediated through the maternal genotype. Birth Defects Research (Part A), 2011. © 2010 Wiley‐Liss, Inc.
Deprotonation of glutamic acid induced by weak magnetic field: An FTIR‐ATR study
Authors: De Ninno A. , Congiu Castellano A. 
Published: December 2010

AbstractIt has been claimed that weak extremely low frequency electromagnetic fields (ELF‐EMFs) can affect biochemical reactions and a wide‐ranging body of literature is available on this topic. Nevertheless, the physical nature of these effects remains largely unknown. We investigated the influence of ELF‐EMF on glutamic acid solutions using Fourier transform infrared‐attenuated total reflectance (FTIR‐ATR) spectra. Samples were exposed for 10, 20, or 30 min to a weak EMF generated by Helmoltz coils, and then placed in a spectrometer. After exposure, those solutions that had a pH lower than the isoelectric point tended to show a shift toward the deprotonation of the carboxylic group, while solutions having a pH greater than the isoelectric point showed the deprotonation of the residual amine group. Moreover, at low pH values, we also detected a shift of the δantisym band of the amine. The effects lasted a few minutes after exposure before the native configuration was restored. The spectral modifications were observed after each independent exposure to EMFs, and the same effects were seen by varying the frequencies in the range of 0–7 kHz. Therefore, the hypothesis of the existence of a resonant frequency that has been proposed elsewhere cannot be supported by the results of this study. The most surprising characteristic of this effect is the long‐lasting nature of the perturbation, which is hard to be explained in terms of short‐living excitations in biological matter. Bioelectromagnetics 32:218–225, 2011. © 2010 Wiley‐Liss, Inc.
Nachweis von Strukturdefekten in Elementwänden mittels zerstörungsfreier Prüfverfahren
Authors: Mähner Dietmar , Thünemann Stefan , Becker Markus 
Published: December 2010

AbstractDer Beitrag befasst sich mit der Nachweisbarkeit von Strukturdefekten in Elementwänden mittels zerstörungsfreier Prüfverfahren. Innerhalb einer Versuchsreihe wurden in Elementwänden vordefinierte Fehlstellen eingebaut, die während der Betonage auf der Baustelle auftreten können. Die Messungen wurden durch verschiedene Messteams mit Ultraschall‐Echo‐, Impact‐Echo‐ und Impuls‐Radar‐Verfahren an einem vorgegebenen Messraster ausgeführt. Dabei konnten die Strukturdefekte vielfach zerstörungsfrei nachgewiesen werden. Die wesentlichen Untersuchungsergebnisse werden nachfolgend dargestellt.Verification of Failure in Prefabricated Walls Using Non‐Destructive Testing MethodsThis essay deals with the verification of failure in prefabricated walls using non‐destructive testing methods. Series of tests were carried out considering several imperfections which might occur on site during construction. Three measuring methods were used by different parties to carry out the tests. These methods were the Ultrasonic Echo Method, the Impact‐Echo Method and Impulse Radar Technique, where in many cases failure could have been detected in using these methods. The main research results are presented here.
Korrosionsmonitoring von Stahlbetonbauwerken als Element des Lebensdauermanagements
Authors: Holst Alexander , Budelmann Harald , Wichmann Hans‐Joachim 
Published: December 2010

AbstractDa korrosionsinduzierte Schäden an Bauwerken im Laufe der Zeit zu immensen Kosten führen, sind die sichere Beurteilung des Korrosionsrisikos und eine frühzeitige Erkennung und zuverlässige Vorhersage der Bewehrungskorrosion Schlüsselaufgaben des Bauwerksmanagements korrodierender Spann‐ und Stahlbetonbauwerke. Eine Bewertung des Korrosionszustands wird durch die Bauwerksüberwachung (Monitoring) objektiv möglich.Im vorliegenden Beitrag werden nach einer kurzen Einführung zum monitoringbasierten Lebensdauermanagement die Entwicklung, Erprobung und Optimierung neuartiger kalibrierungsfreier Miniatursensoren zur Erfassung der Bewehrungskorrosion in Betonbauteilen vorgestellt. Mit diesen vielseitig einsetzbaren Korrosionsstellvertretersensoren, die aus mehreren im Bereich der Betonüberdeckung angeordneten, 0,065 mm bis ca. 0,5 mm dünnen Stahldrähten bestehen, kann das Eindringen der Depassivierungsfront in den Beton einfach, zuverlässig und kostengünstig überwacht werden. Basierend auf umfangreichen Untersuchungen im Labormaßstab und der Anwendungserprobung im Zeitraum von mehr als sechs Jahren werden die Erkenntnisse und Weiterentwicklungen der Drahtsensorik präsentiert und diskutiert.Corrosion Monitoring as an Element of Service‐Life‐ManagementApplication of innovative filament sensors for rebar corrosion survey Since corrosion induced damages at civil structures result in enormous costs over lifetime, the assured assessment of the corrosion risk and an early identification and reliable prognosis of rebar corrosion are key tasks of the building management of corroding prestressed and steel reinforced concrete structures. Here an evaluation of the corrosion state is objectively possible by means of Structural Health Monitoring (SHM).In this contribution after a brief introduction of monitoring based service‐life‐management, the development, testing and optimization of novel calibration‐free miniature sensors for the detection of rebar corrosion in concrete members are introduced. By means of these versatile corrosion dummy sensors, made from several 0,065 mm up to 0,5 mm thin steel filaments and mounted within the concrete cover, the penetration of the depassivation front into concrete can be observed easily, reliably and cost effectively. Based upon various investigations in the lab scale and application testing during the time period of six years, the findings and further developments of the filament sensor will be presented and discussed.
Korrosionsbeständigkeit eines nichtrostenden Chromstahls in karbonatisiertem Normal‐, Leicht‐ und Recyclingbeton
Authors: Hunkeler Fritz , Bäurle Lukas 
Published: December 2010

AbstractUm der Forderung nach Nachhaltigkeit nachzukommen, wird in den nächsten Jahren der Einsatz von Betonen mit rezyklierten Gesteinskörnungen (Beton‐ und Mischabbruch) zunehmen. Wegen den wärmedämmenden Eigenschaften wird auch der Bedarf an Betonen mit Leichtzuschlägen (z. B. Blähglas) steigen. Als wesentliches Element dieser Entwicklung werden für die Zementund Betonproduktion zunehmend Zemente mit reduziertem Portlandzementklinkergehalt sowie Zusatzstoffe wie Flugasche und Hüttensand verwendet. Damit nimmt der Karbonatisierungswiderstand der Betone tendenziell ab und das Risiko für Korrosionsschäden zu. Die nachfolgend vorgestellten Untersuchungen hatten zum Ziel, die Korrosionsbeständigkeit eines nichtrostenden Chromstahls (Top12, Zusammensetzung entspricht ungefähr dem Stahl mit der Werkstoffnummer 1.4003) in karbonatisiertem Beton mit unterschiedlicher Zusammensetzung zu evaluieren, mit normalem Betonstahl zu vergleichen und zu beurteilen. Die Ergebnisse lassen den Schluss zu, dass der Top12, im Gegensatz zum normalen Betonstahl, in allen untersuchten Betonen und damit auch in stark karbonatisierten Recyclingbetonen beständig ist.Corrosion Resistance of a Stainless Chromium‐Steel in Carbonated Ordinary, Light‐Weight and Recycling ConcreteIn order to achieve the goals for a sustainable development, concrete with recycled aggregates (concrete and mixtures from concrete and masonry, e.g. clay bricks and calcium silicate blocks etc.) is going to be used more and more in the future. Due to its thermal insulating properties, the demand for concrete with light‐weight aggregates (e.g. foam glass) will also increase. As an essential element of this development, an increasing amount of cements with a reduced clinker factor as well as of mineral additions such as fly ash and ground granulated blast furnace slag is used for concrete production. Therefore, as a general tendency, the carbonation resistance of concrete mixes decreases while the risk of corrosion damages increases. The goal of the investigations described in this paper was to evaluate and to assess the corrosion resistance of a stainless rebar (Top12, composition corresponds approx. to steel grade 1.4003) in various carbonated concrete mixes and to compare the results with common rebars. The results lead to the conclusion that, in contrast to common rebars, Top12 is durable in all investigated concrete mixes, including strongly carbonated recycling concretes.
A gaussian model for substrates of entangled cross‐linked poly(ethylene glycol) in biomedical applications
Authors: Eskandari Mahnaz , Brey Eric , Cinar Ali 
Published: December 2010

AbstractCells usually spread on a synthetic substrate through bonds between receptors and chemical groups on the substrate (ligands). Therefore, it is valuable to study the effects of the average number density of these chemical groups and the average distance between them to model and predict the cell behavior. Poly(ethylene glycol) [PEG] modified with peptide groups has been used widely in biomedical applications as a substrate material. In this study, a coarse‐grained model is proposed for PEG to predict the average number density of ligands and the average distance between them. Molecular information such as initial molecular weight distribution, average molecular weight between cross‐links, and average molecular weight between entanglements is used as input parameters. Based on simulation results, it is concluded that both entanglement and cross‐link densities are required to create a network structure. The results suggest that an average initial molecular weight 2–3 times the average molecular weight between entanglements and a moderate cross‐link density are sufficient to create a closed network structure with a high ligand density and a small average distance between them. Biotechnol. Bioeng. 2011;108: 435–445. © 2010 Wiley Periodicals, Inc.
Ionic liquid pretreatment of cellulosic biomass: Enzymatic hydrolysis and ionic liquid recycle
Authors: Shill Kierston , Padmanabhan Sasisanker , Xin Qin , Prausnitz John M. , Clark Douglas S. , Blanch Harvey W. 
Published: December 2010

AbstractIonic liquids (ILs) are promising solvents for the pretreatment of biomass as certain ILs are able to completely solubilize lignocellulose. The cellulose can readily be precipitated with an anti‐solvent for further hydrolysis to glucose, but the anti‐solvent must be removed for the IL to be recovered and recycled. We describe the use of aqueous kosmotropic salt solutions to form a three‐phase system that precipitates the biomass, forming IL‐rich and salt‐rich phases. The phase behavior of [Emim][Ac] and aqueous phosphate salt systems is presented, together with a process for recycling the [Emim][Ac] and enzymatically hydrolyzing the cellulose. This process reduces the amount of water to be evaporated from recycled IL, permitting efficient recycle of the IL. Material balances on the process, with multiple recycles of the [Emim][Ac], quantify the major components from a Miscanthus feedstock through the pretreatment, separation, and enzymatic hydrolysis steps. A more rapid and higher yielding conversion of cellulose to glucose is obtained by use of the three‐phase system as compared to the cellulose obtained from biomass pretreated with IL and precipitated with water. The addition of a kosmotropic salt during the precipitation results in partial delignification of the biomass, which makes the substrate more accessible, enhancing the enzymatic hydrolysis. Biotechnol. Bioeng. 2011; 108:511–520. © 2010 Wiley Periodicals, Inc.
Microalgae—novel highly efficient starch producers
Authors: Brányiková Irena , Maršálková Barbora , Doucha Jiří , Brányik Tomáš , Bišová Kateřina , Zachleder Vilém , Vítová Milada 
Published: December 2010

AbstractThe freshwater alga Chlorella, a highly productive source of starch, might substitute for starch‐rich terrestrial plants in bioethanol production. The cultivation conditions necessary for maximizing starch content in Chlorella biomass, generated in outdoor scale‐up solar photobioreactors, are described. The most important factor that can affect the rate of starch synthesis, and its accumulation, is mean illumination resulting from a combination of biomass concentration and incident light intensity. While 8.5% DW of starch was attained at a mean light intensity of 215 µmol/(m2 s1), 40% of DW was synthesized at a mean light intensity 330 µmol/(m2 s1). Another important factor is the phase of the cell cycle. The content of starch was highest (45% of DW) prior to cell division, but during the course of division, its cellular level rapidly decreased to about 13% of DW in cells grown in light, or to about 4% in those kept in the dark during the division phase. To produce biomass with high starch content, it is necessary to suppress cell division events, but not to disturb synthesis of starch in the chloroplast. The addition of cycloheximide (1 mg/L), a specific inhibitor of cytoplasmic protein synthesis, and the effect of element limitation (nitrogen, sulfur, phosphorus) were tested. The majority of the experiments were carried out in laboratory‐scale photobioreactors, where culture treatments increased starch content to up to about 60% of DW in the case of cycloheximide inhibition or sulfur limitation. When the cells were limited by phosphorus or nitrogen supply, the cellular starch content increased to 55% or 38% of DW, respectively, however, after about 20 h, growth of the cultures stopped producing starch, and the content of starch again decreased. Sulfur limited and cycloheximide‐treated cells maintained a high content of starch (60% of DW) for up to 2 days. Sulfur limitation, the most appropriate treatment for scaled‐up culture of starch‐enriched biomass, was carried out in an outdoor pilot‐scale experiment. After 120 h of growth in complete mineral medium, during which time the starch content reached around 18% of DW, sulfur limitation increased the starch content to 50% of DW. Biotechnol. Bioeng. 2011; 108:766–776. © 2010 Wiley Periodicals, Inc.
Developing the TriLab, a triple access mode (hands‐on, virtual, remote) laboratory, of a process control rig using LabVIEW and Joomla
Authors: Abdulwahed Mahmoud , Nagy Zoltan K. 
Published: December 2010

AbstractLaboratory education is a core part of engineering curricula; engineering students generally prefer to work on something real. The classical mode and the oldest form of laboratory education is the hands‐on mode. Advances in information and communication technologies have contributed to the laboratory education by creating two new modes, the simulated (virtual) mode and the online controlled mode (remote). Recently, developments or utilizations of hybrid structures of two types (e.g., virtual and hands‐on, or remote and hands‐on) have been reported in the literature; however, until now there are no reports of hybrid structures of the three types together. This paper describes the technical development of a novel laboratory model that combines the three modes in one unifying software package, namely the TriLab, by using Laboratory Virtual Instrument Engineering Workbench (LabVIEW). It is shown that LabVIEW provides a single programming environment for developing all components of the TriLab. Furthermore, it is shown that the Joomla web content management system can be used as a solution for efficient deployment of a remote lab online portal on the top of the LabVIEW core software. The development of the TriLab using LabVIEW and Joomla for an Instrumentation and Control Engineering Laboratory rig is shown. The analysis of student survey is presented which has shown positive impact of the pedagogical utilization of the TriLab. This is the first paper which aims to provide engineering academics a generic architecture and software solutions to rapidly develop their own TriLab. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 21: 614–626, 2013
Ultra‐small gadolinium oxide nanoparticles to image brain cancer cells in vivo with MRI
Authors: Faucher Luc , Guay‐Bégin Andrée‐Anne , Lagueux Jean , Côté Marie‐France , Petitclerc Éric , Fortin Marc‐André 
Published: December 2010

AbstractThe majority of contrast agents used in magnetic resonance imaging (MRI) is based on the rare‐earth element gadolinium. Gadolinium‐based nanoparticles could find promising applications in pre‐clinical diagnostic procedures of certain types of cancer, such as glioblastoma multiforme. This is one of the most malignant, lethal and poorly accessible forms of cancer. Recent advances in colloidal nanocrystal synthesis have led to the development of ultra‐small crystals of gadolinium oxide (US‐Gd2O3, 2–3 nm diameter). As of today, this is the smallest and the densest of all Gd‐containing nanoparticles. Cancer cells labeled with a sufficient quantity of this compound appear bright in T1‐weighted MRI images. Here we demonstrate that US‐Gd2O3 can be used to label GL‐261 glioblastoma multiforme cells, followed by localization and visualization in vivo using MRI. Very high amounts of Gd are efficiently internalized and retained in cells, as confirmed with TEM and ICP‐MS. Labeled cells were visualized in vivo at 1.5 T using the chicken embryo model. This is one more step toward the development of “positively contrasted” cell tracking procedures with MRI. Copyright © 2010 John Wiley & Sons, Ltd.