bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of hydrogen‐bonding in the development of high‐affinity metal ion complexants: Polymer‐bound phosphorylated cyclodextrin
Authors: Zhu Xiaoping , Alexandratos Spiro D. 
Published: March 2011

AbstractIn a series of phosphorylated polyols bound to a polystyrene support, the position of the FTIR band assigned to hydrogen bonding between the OH and phosphoryl oxygen correlates with the affinity of that phosphoryl oxygen for metal ions. Polymer with phosphorylated β‐cyclodextrin (pCD) ligands is now reported as a further test of this correlation. The metal ion affinity is probed with the uranyl ion. pCD is the most red‐shifted of a series of five phosphorylated polyols: the strongest polyol had been phosphorylated pentaerythritol (pPE) with a band at 873 cm−1; pCD has a band at 868 cm−1. Consistent with the FTIR bands, pCD has a significantly higher affinity for the uranyl ion than pPE: the percents complexed from a 10−4M uranyl solution in a background of 1.0N HNO3, HCl, and H2SO4 are 94.7%, 90.5%, and 93.6%, respectively, for pCD and 68.6%, 52.1%, and 40.1%, respectively, for pPE. This further supports the hypothesis that the strong complexing ability of phosphorylated polyols is due to activation of the phosphoryl oxygen through hydrogen bonding between the PO and the OH groups within the polyol. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Morphology change of biaxially oriented polytetrafluoroethylene membranes caused by solvent soakage
Authors: Zhengbang Wang , Haolin Tang , Junsheng Li , Mu Pan 
Published: March 2011

AbstractThe morphological changes of expanded polytetrafluoroethylene (ePTFE) membrane caused by solvent soakage were investigated in this study. The results demonstrated that the wettable solvent with low contact angle towards PTFE membrane can introduce huge stress to the ePTFE membrane and make the membrane shrinkage, and the stress is generated in the solvent evaporation procedure. The pore size and membrane dimension shrinkage of ePTFE membrane improved with the decrease of the solvent contact angle and surface tension. For ethanol and isopropanol with contact angle of 23° and 20°, the membrane thickness shrinkness are 15.0% and 16.7%, respectively. The evaporation‐induced stress towards the ePTFE membrane also increases with the decrease of the solvent contact angle to the ePTFE membrane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Histologic Distribution, Fragment Cloning, and Sequence Analysis of G Protein Couple Receptor 30 in Rat Submaxillary Gland
Authors: Chen Lei , Mei Xiao‐Peng , Gao Chang‐Jun , Zhang Gui‐He , Sun Xu‐De 
Published: March 2011

AbstractRecent studies indicated that G protein couple receptor 30 (GPR30), a nongenomic estrogen receptor, is widely expressed in many organ systems inducing many quick reaction of estrogen. However, there was rare report about the expression of GPR30 in the salivary gland. In the present study, we investigated the distribution of GPR30 in rat submaxillary gland by means of immunohistochemistry and in situ hybridization. GPR30 core sequences were amplified by RT‐PCR with total RNA extracted from rat submaxillary gland and were analyzed by sequencing with Sanger's method. The results showed that the epithelial cells of serous alveoli and granular convoluted duct in rat submaxillary gland displayed GPR30‐immunoreactivity on the plasma membrane and cytoplasm. Moreover, GPR30 mRNA hybridization signals were also detected in the cytoplasm of the above cells. GPR30 cDNA sequence cloned from rat submaxillary gland is identical to that of GPR30 from rat paraventricular and supraoptic nucleus. In conclusion, the expression of GPR30 in the serous and granular epithelial cells of submaxillary gland indicates that submaxillary gland could also be a target organ rapidly responding to estrogen stimulus, and estrogen may be involved in the functional regulation of submaxillary gland. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
The Jaw Adductors of Strepsirrhines in Relation to Body Size, Diet, and Ingested Food Size
Authors: Perry Jonathan M.G. , Hartstone‐Rose Adam , Wall Christine E. 
Published: March 2011

AbstractBody size and food properties account for much of the variation in the hard tissue morphology of the masticatory system whereas their influence on the soft tissue anatomy remains relatively understudied. Data on jaw adductor fiber architecture and experimentally determined ingested food size in a broad sample of 24 species of extant strepsirrhines allows us to evaluate several hypotheses about the influence of body size and diet on the masticatory muscles. Jaw adductor mass scales isometrically with body mass (β = 0.99, r = 0.95), skull size (β = 1.04, r = 0.97), and jaw length cubed (β = 1.02, r = 0.95). Fiber length also scales isometrically with body mass (β = 0.28, r = 0.85), skull size (β = 0.33, r = 0.84), and jaw length cubed (β = 0.29, r = 0.88). Physiological cross‐sectional area (PCSA) scales with isometry or slight positive allometry with body mass (β = 0.76, r = 0.92), skull size (β = 0.78, r = 0.94), and jaw length cubed (β = 0.78, r = 0.91). Whereas PCSA is isometric to body size estimates in frugivores, it is positively allometric in folivores. Independent of body size, fiber length is correlated with maximum ingested food size, suggesting that ingestive gape is related to fiber excursion. Comparisons of temporalis, masseter, and medial pterygoid PCSA in strepsirrhines of different diets suggest that there may be functional partitioning between these muscle groups. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Altered posterior cingulate cortical cyctoarchitecture, but normal density of neurons and interneurons in the posterior cingulate cortex and fusiform gyrus in autism
Authors: Oblak Adrian L. , Rosene Douglas L. , Kemper Thomas L. , Bauman Margaret L. , Blatt Gene J. 
Published: March 2011

AbstractAutism is a developmental disorder with prenatal origins, currently estimated to affect 1 in 91 children in the United States. Social‐emotional deficits are a hallmark of autism and early neuropathology studies have indicated involvement of the limbic system. Imaging studies demonstrate abnormal activation of the posterior cingulate cortex (PCC), a component of the limbic system. Abnormal activation has also been noted in the fusiform gyrus (FFG), a region important for facial recognition and a key element in social interaction. A potential imbalance between excitatory and inhibitory interneurons in the cortex may contribute to altered information processing in autism. Furthermore, reduced numbers of GABA receptors have previously been reported in the autistic brain. Thionin‐stained sections were used to qualitatively assess cytoarchitectonic patterning and quantitatively determine the density of neurons and immunohistochemistry was used to determine the densities of a subset of GABAergic interneurons utilizing parvalbumin‐and calbindin‐immunoreactivity. In autism, the PCC displayed altered cytoarchitecture with irregularly distributed neurons, poorly demarcated layers IV and V, and increased presence of white matter neurons. In contrast, no neuropathology was observed in the FFG. There was no significant difference in the density of thionin, parvalbumin, or calbindin interneurons in either region and there was a trend towards a reduced density of calbindin neurons in the PCC. This study highlights the presence of abnormal findings in the PCC, which appear to be developmental in nature and could affect the local processing of social–emotional behaviors as well as functioning of interrelated areas. Autism Res 2011,4:200–211. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.
Not a walk in the park: the ECVAM whole embryo culture model challenged with pharmaceuticals and attempted improvements with random forest design
Authors: Thomson Jason , Johnson Kjell , Chapin Robert , Stedman Donald , Kumpf Steven , Ozolinš Terence R.S. 
Published: March 2011

AbstractBackground:The European Committee for the Validation of Alternative Methods (ECVAM) supported the development of a linear discriminant embryotoxicity prediction model founded on rat whole embryo culture (Piersma et al. (2004). Altern Lab Anim 32:275–307). Our goals were to (1) assess the accuracy of this model with pharmaceuticals, and (2) to use the data to develop a more accurate prediction model.Methods:Sixty‐one chemicals of knownin vivoactivity were tested. They were part of the ECVAM validation set (N= 13), commercially available pharmaceuticals (N= 31), and Pfizer chemicals that did not reach the market, but for which developmental toxicity data were available (N= 17). They were tested according to the ECVAM procedures. Fifty‐seven of these chemicals were used for Random Forest modeling to develop an alternate model with the goal of using surrogate endpoints for simplified assessments and to improve the predictivity of the model.Results:Using part of the ECVAM chemical test set, the ECVAM prediction model was 77% accurate. This approximated what was reported in the validation study (80%; Piersma et al. (2004). Altern Lab Anim 32:275–307). However, when confronted with novel chemicals, the accuracy of the linear discriminant model dropped to 56%. In an attempt to improve this performance, we used a Random Forest model that provided rankings and confidence estimates. Although the model used simpler endpoints, its performance was no better than the ECVAM linear discriminant model.Conclusions:This study confirms previous concerns about the applicability of the ECVAM prediction model to a more diverse chemical set, and underscores the challenges associated with developing embryotoxicity prediction models.Birth Defects Res (Part B)92:111–121, 2011.  © 2011 Wiley‐Liss, Inc.
Berücksichtigung von Viskoelastizität bei der Beurteilung von Zwangbeanspruchungen erhärtender Massenbetonbauteile
Authors: Nietner Lutz , Schlicke Dirk , Tue Nguyen Viet 
Published: March 2011

AbstractDer nachfolgende Aufsatz behandelt die Berechnung und Messung von hydratationsbedingten Zwangspannungen in massigen Betonbauteilen. Dabei wird auf das zeitveränderliche und viskoelastische Materialverhalten des Betons und dessen Berücksichtigung innerhalb eines numerischen Berechnungsverfahrens besonders eingegangen. Die vorgestellten Zusammenhänge werden anhand eines Dehnstabmodells mathematisch beschrieben und innerhalb eines FE‐Modells numerisch implementiert. Im Zuge des Betonierens einer Sohlplatte eines Schleusenbauwerks werden die Berechnungsergebnisse mit Messdaten für die Spannungsentwicklung verglichen und bewertet.Consideration of Viscoelasticity in Computation of Hydration induced Stresses in Massive Concrete MembersThe present document reports about the computation and measurement of hydration induced stresses in massive concrete structures. It focuses on the time dependent and viscoelastic material properties of concrete and their consideration within a numerical computation procedure. The presented relationships will be described mathematically by using a strain‐rod‐model and be implemented in a FEM‐Model. The computed results will be compared and evaluated by using measured stress data obtained during the casting of a lock's base slab.
Korrosionsinhibitoren für die Instandsetzung chloridverseuchter Stahlbetonbauten
Authors: Hunkeler Fritz , Mühlan Björn , Ungricht Heidi 
Published: March 2011

AbstractDer Einsatz von Inhibitoren wird weltweit als technisch und wirtschaftlich interessante Alternative zur konventionellen Instandsetzung von Stahlbetonbauten betrachtet, da der Betonabtrag erheblich reduziert oder sogar ganz wegfallen kann. In diesem Aufsatz werden die Resultate von praxisnahen Laboruntersuchungen vorgestellt (aktive, d. h. laufende Bewehrungskorrosion, unterschiedliche Bewehrungsüberdeckung, unterschiedlicher Chloridgehalt im Untergrund bzw. im “Altbeton”, Makroelementwirkung). Keines der drei geprüften Systeme war in der Lage, die Korrosionsgeschwindigkeit zu reduzieren oder sogar zu stoppen.Corrosion Inhibitors for the Rehabilitation of Chloride Contaminated Reinforced Concrete StructuresThe use of inhibitors is considered worldwide as a technically and economically interesting alternative to the conventional repair of reinforced concrete structures since the removal of concrete can be considerably reduced or completely omitted. In this contribution the results of practical laboratory investigations are presented (active, e.g. ongoing corrosion, different concrete cover depths and chloride contents of the substrate or “old concrete”, macroelement effect). None of the three tested systems was able to reduce the corrosion rate or to stop the corrosion.
Hinweise zur Bemessung von Stahlbetonsilos bei exzentrischer Entleerung nach DIN EN 1991‐4
Authors: Ruckenbrod Cornelius , Stech Karl‐Heinz , Grimaldi Thomas 
Published: March 2011

AbstractFür rotationssymmetrische Silozellen mit exzentrischer Entleerung geben die derzeit noch gültige DIN 1055‐6 und die bald maßgebliche DIN EN 1991‐4 Lastansätze vor, die für eine Siloschale zu einer sehr ungünstigen Beanspruchungskombination von Biegung, Quer‐ und Längszugkräften führt. In diesem Beitrag werden die Hintergründe der Lastansätze erläutert und auf Besonderheiten bei der Bemessung in der Anwendung der einschlägig zur Verfügung stehenden Bemessungsnormen hingewiesen.Remarks to the Design of Concrete Silos with large Discharge Eccentricities according to DIN EN 1991‐4Where large eccentricities of discharge occur in circular silo bins DIN 1055‐6:2005 and DIN 1991‐4 define special different load cases resulting in a very unfavourable design situation with bending, tensile and shear forces. In this paper special background information are given of the loading rules and due to the specifics in using the existing relevant design codes.
Repression of xylose‐specific enzymes by ethanol inScheffersomyces(Pichia)stipitisand utility of repitching xylose‐grown populations to eliminate diauxic lag
Authors: Slininger Patricia J. , Thompson Stephanie R. , Weber Scott , Liu Z. Lewis , Moon Jaewoong 
Published: March 2011

AbstractDuring the fermentation of lignocellulosic hydrolyzates to ethanol by native pentose‐fermenting yeasts such asScheffersomyces(Pichia)stipitisNRRL Y‐7124 (CBS 5773) andPachysolen tannophilusNRRL Y‐2460, the switch from glucose to xylose uptake results in a diauxic lag unless process strategies to prevent this are applied. When yeast were grown on glucose and resuspended in mixed sugars, the length of this lag was observed to be a function of the glucose concentration consumed (and consequently, the ethanol concentration accumulated) prior to the switch from glucose to xylose fermentation. At glucose concentrations of 95 g/L, the switch to xylose utilization was severely stalled such that efficient xylose fermentation could not occur. Further investigation focused on the impact of ethanol on cellular xylose transport and the induction and maintenance of xylose reductase and xylitol dehydrogenase activities when large cell populations ofS. stipitisNRRL Y‐7124 were pre‐grown on glucose or xylose and then presented mixtures of glucose and xylose for fermentation. Ethanol concentrations around 50 g/L fully repressed enzyme induction although xylose transport into the cells was observed to be occurring. Increasing degrees of repression were documented between 15 and 45 g/L ethanol. Repitched cell populations grown on xylose resulted in faster fermentation rates, particularly on xylose but also on glucose, and eliminated diauxic lag and stalling during mixed sugar conversion byP. tannophilusorS. stipitis, despite ethanol accumulations in the 60 or 70 g/L range, respectively. The process strategy of priming cells on xylose was key to the successful utilization of high mixed sugar concentrations because specific enzymes for xylose utilization could be induced before ethanol concentration accumulated to an inhibitory level. Biotechnol. Bioeng. 2011; 108:1801–1815. © 2011 Wiley Periodicals, Inc.
Mechanism and Origins of Regio‐ and Enantioselectivities in RhI‐Catalyzed Hydrogenative Couplings of 1,3‐Diynes and Activated Carbonyl Partners: Intervention of a Cumulene Intermediate
Authors: Liu Peng , Krische Michael J. , Houk Kendall N. 
Published: March 2011

AbstractThe mechanism of the rhodium‐catalyzed reductive coupling of 1,3‐diynes and vicinal dicarbonyl compounds employing H2 as reductant was investigated by density functional theory. Oxidative coupling through 1,4‐addition of the RhI‐bound dicarbonyl to the conjugated diyne via a seven‐membered cyclic cumulene transition state leads to exclusive formation of linear adducts. Diyne 1,4‐addition is much faster than the 1,2‐addition to simple alkynes. The 1,2‐dicarbonyl compound is bound to rhodium in a bidentate fashion during the oxidative coupling event. The chemo‐, regio‐, and enantioselectivities of this reaction were investigated and are attributed to this unique 1,4‐addition pathway. The close proximity of the ligand and the alkyne substituent distal to the forming CC bond controls the regio‐ and enantioselectivity: coupling occurs at the sterically more demanding alkyne terminus, which minimizes nonbonded interaction with the ligand. A stereochemical model is proposed that accounts for preferential formation of the (R)‐configurated coupling product when (R)‐biaryl phosphine ligands are used.
Enzymatic Cascade Reactions inside Polymeric Nanocontainers: A Means to Combat Oxidative Stress
Authors: Tanner Pascal , Onaca Ozana , Balasubramanian Vimalkumar , Meier Wolfgang , Palivan Cornelia G. 
Published: March 2011

AbstractOxidative stress, which is primarily due to an imbalance in reactive oxygen species, such as superoxide radicals, peroxynitrite, or hydrogen peroxide, represents a significant initiator in pathological conditions that range from arthritis to cancer. Herein we introduce the concept of enzymatic cascade reactions inside polymeric nanocontainers as an effective means to detect and combat superoxide radicals. By simultaneously encapsulating a set of enzymes that act in tandem inside the cavities of polymeric nanovesicles and by reconstituting channel proteins in their membranes, an efficient catalytic system was formed, as demonstrated by fluorescence correlation spectroscopy and fluorescence cross‐correlation spectroscopy. Superoxide dismutase and lactoperoxidase were selected as a model to highlight the combination of enzymes. These were shown to participate in sequential reactions in situ in the nanovesicle cavity, transforming superoxide radicals to molecular oxygen and water and, therefore, mimicking their natural behavior. A channel protein, outer membrane protein F, facilitated the diffusion of lactoperoxidase substrate/products and dramatically increased the penetration of superoxide radicals through the polymer membrane, as established by activity assays. The system remained active after uptake by THP‐1 cells, thus behaving as an artificial organelle and exemplifying an effective approach to enzyme therapy.
Multi‐Electron‐Acceptor Dyad and Triad Systems Based on Perylene Bisimides and Fullerenes
Authors: Chamberlain Thomas W. , Davies E. Stephen , Khlobystov Andrei N. , Champness Neil R. 
Published: March 2011

AbstractFullerene (C60) and 3,4,9,10‐perylene tetracarboxylic diimide (PTDCI) were used as building blocks for an electron acceptor dyad (C60–PTCDI) and triad (C60–PTCDI–C60). As the first reduction potentials for C60 and PTCDI are very close, simultaneous introduction of two or three electrons is possible into the dyad and triad, respectively. Further stepwise electrochemical reduction leads to formation of a series of well‐defined anionic species in which electrons associated with the fullerene or the PTDCI components of the molecule can be clearly distinguished. In total, up to four electrons can be reversibly injected into the dyad C60–PTCDI and up to six into the triad C60–PTCDI–C60 system. The optical absorption properties in the UV/Vis range are also crucially defined by the distribution of electrons between the acceptor parts, as the injection/removal of electrons causes drastic colour changes in the dyad and the triad systems.
Metabolic flux‐based optimisation of recombinant human interleukin‐3 expression by Streptomyces lividans 66
Authors: Nowruzi Keyvan , Elkamel Ali , Scharer Jeno M. , Cossar Douglas , Moo‐Young Murray 
Published: March 2011

AbstractA metabolic reaction network including carbohydrate and amino acid metabolism in both anabolic and catabolic reactions was developed for Streptomyces lividans. Based on observed nutrient consumption, the fermentation process comprised two stages: amino acid uptake in the first phase followed by ammonia uptake as the nitrogen source in the second phase. Linear programming in combination with eight measured input and output fluxes was employed to determine the flux distribution through the major metabolic pathways in both phases of the batch fermentations. Two different objective functions were defined and examined: optimising biomass production by maximising the specific growth rate and optimising a balanced redox metabolism by minimising excess NAD(P)H production. The flux distributions obtained for the two objectives were very similar. The model predicted specific growth rate agreed well (8–10% difference) with observations. A uniform distribution was assumed for each biomass component and the results showed that, using either objective the biomass composition does not have a significant effect on the internal distribution of fluxes.
Removal of direct Red‐31 and direct Orange‐26 by low cost rice husk: Influence of immobilisation and pretreatments
Authors: Safa Yusra , Bhatti Haq Nawaz , Bhatti Ijaz Ahmad , Asgher Muhammad 
Published: March 2011

AbstractThe aim of the present study is to investigate the influence of free, carboxymethyl cellulose (CMC) immobilised, PVA–alginate immobilised, and HCl treated rice husk on the removal of Direct Red‐31 and Direct Orange‐26 dyes. The biosorption capacity of the rice husk increased with HCl treatment (67.39 and 45.34 mg/g) and decreased with PVA–alginate immobilisation (9.73 and 10.03 mg/g) as compared to the free biomass (65.56 and 45.58 mg/g) at 200 mg/L dye concentration for Direct Red‐31 and Direct Orange‐26, respectively. Equilibrium data were best described by Langmuir Type 1 for Direct Red‐31 and Direct Orange‐26 (free, CMC immobilised, PVA–alginate immobilised, and HCl treated). Best correlation coefficients for Direct Red‐31 and Direct Orange‐26 using free, CMC immobilised, PVA–alginate immobilised, and HCl treated rice husk were obtained for pseudo‐second order and Elovich kinetic models. Values of Gibbs free energy (ΔG°) and enthalpy change (ΔH°) indicated that reaction was spontaneous and endothermic in nature at the studied temperatures. FT‐IR studies showed the involvement of carbonyl, carboxyl, and amide groups in the biosorption process. SEM exhibited the morphological changes on the biosorbent surface and BET analysis to determine the surface area is also carried out.