bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective acetylene hydrogenation over core–shell magnetic Pd‐supported catalysts in a magnetically stabilized bed
Authors: Dong Minghui , Pan Zhiyong , Peng Ying , Meng Xiangkun , Mu Xuhong , Zong Baoning , Zhang Jinli 
Published: March 2008

AbstractA novel magnetic microspherical catalyst support with enough mechanical strength was prepared through coating Al2O3on a magnetic core of NiFe2O4spinel ferrite using the oil drop method to synthesize magnetic Pd‐supported catalyst for acetylene hydrogenation reaction. The synthesized core–shell composite Pd/Al2O3catalyst shows high surface area and pore volume as well as sufficient saturated magnetization property, characterized by powder X‐ray diffraction, low‐temperature N2adsorption–desorption analysis, and magnetic measurements. Catalytic performance of this magnetic Pd/Al2O3catalyst was measured for acetylene hydrogenation reaction in a magnetically stabilized bed (MSB) reactor under different operation conditions. Under the optimal conditions of 353 K, 1.5 MPa and a gas hourly space velocity of 12,000 h−1, C2H2conversion and C2H4selectivity approximated 100% and 84%, respectively, over this magnetic Pd/Al2O3catalyst in the MSB reactor, as a control over the commercial catalyst for hydrogenation reaction C2H2conversion and C2H4selectivity was near 37 and 64% under the similar conditions. Significant improvement of acetylene hydrogenation processes over this novel magnetic catalyst enlightens us a promising route to explore process intensification techniques through MSB. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Kinetic characterization of biomass dilute sulfuric acid hydrolysis: Mixtures of hardwoods, softwood, and switchgrass
Authors: Jensen Jill , Morinelly Juan , Aglan Anwar , Mix Adam , Shonnard David R. 
Published: March 2008

AbstractThe effects of woody biomass mixtures were investigated on the rates of hemicellulose hydrolysis by dilute acid. Very good agreement between the model predictions and single species acid hydrolysis data confirmed the validity of a pseudo first‐order model approach. This model was then utilized to predict monomer sugar concentrations for mixtures of hardwood (aspen, basswood, and red maple), a softwood (balsam), and the energy crop switchgrass, with very good agreement. The results of this study show that there are not significant synergistic or antagonistic effects by mixtures of woody biomass species on the kinetics of hemicellulose hydrolysis by dilute acid. Kinetic parameters were developed for each woody biomass species with xylose formation activation energies ranging from 76.19–171.20 kJ/mol, and pre‐exponential factors ranging from 2.19 × 108–7.73 × 1019 min−1. Overall xylose yields for pure biomass species ranged from approximately 66–88% with balsam having the lowest yield and switchgrass producing the highest yield. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Gelatin multilayers assembled on poly(L‐lactic acid) surface for better cytocompatibility
Authors: Lin Yuan , Chen Xuesi , Jing Xiabin , Jiang Yinshan , Su Zhaohui 
Published: March 2008

AbstractGelatin multilayers were assembled on PLLA substrate at pH 3, 5, and 7, which was below, around, and above the isoelectric point of the amphoteric polymer, using the layer‐by‐layer assembly technique. The multilayer deposition on the PLLA substrate was monitored by X‐ray photoelectron spectroscopy (XPS) and water contact angle measurement. The XPS, water contact angle, and atomic force microscopy data indicated that the layer thickness, surface hydrophilicity, and surface morphology of the gelatin multilayers assembled strongly depended on the pH at which the layers were deposited. Chondrocyte culture was used to test the cell attachment, cell morphology, and cell viability on the PLLAs modified with gelatin multilayers. All these modified PLLAs exhibited dramatically improved cytocompatibility compared with the virgin PLLA, and even better performance than that of tissue culture polystyrene (TCPS). The best cell compatibility was observed for the gelatin multilayers assembled at pH = 5. These results indicate that the cell compatibility of biodegradable polyesters can be effectively and facilely improved by assembly of gelatin multilayers, and the performance can be controlled by adjusting the solution pH at which the multilayers are deposited. This may help the design and fabrication of better scaffolds for tissue engineering. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Beliefs about what types of mechanisms produce random sequences
Authors: Blinder Deborah S. , Oppenheimer Daniel M. 
Published: March 2008

AbstractAlthough many researchers use Wagenaar's framework for understanding the factors that people use to determine whether a process is random, the framework has never undergone empirical scrutiny. This paper uses Wagenaar's framework as a starting point and examines the three properties of his framework—independence of events, fixed alternatives, and equiprobability. We find strong evidence to suggest that independence of events is indeed used as a cue toward randomness. Equiprobability has an effect on randomness judgments. However, it appears to work only in a limited role. Fixedness of alternatives is a complex construct that consists of multiple sub‐concepts. We find that each of these sub‐concepts influences randomness judgments, but that they exert forces in different directions. Stability of outcome ratios increases randomness judgments, while knowledge of outcome ratios decreases randomness judgments. Future directions for development of a functional framework for understanding perceptions of randomness are suggested. Copyright © 2008 John Wiley & Sons, Ltd.
SAR and efficiency evaluation of a 900 MHz waveguide chamber for cell exposure
Authors: De Prisco Giuseppe , d'Ambrosio Guglielmo , Calabrese Maria Lucia , Massa Rita , Juutilainen Jukka 
Published: March 2008

AbstractIn this work we present the results of numerical and experimental dosimetry carried out for an in vitro exposure device to irradiate sample groups at 900 MHz. The cells are kept in 8 and 15 ml cell cultures, contained, respectively in T25 and T75 rectangular flasks. The dosimetric assessment of the distribution of the specific absorption rate (SAR) is performed for both the bottom of the flask and the whole volume of the sample to provide results for experiments on either the cell layer or the cell suspension. The irradiating chamber is a rectangular waveguide (WG). Different configurations are considered to assess the optimum orientation and positioning of the cell cultures inside the WG. The system performance is optimal when the electric field is parallel to the sample and the WG is terminated by a matched load. In this condition two 15 or four 8 ml cells cultures can be exposed. The efficiency (ratio between the power absorbed by the sample and the incident power) and the non‐uniformity degree (ratio between the standard deviation of SAR values and the average SAR over the sample) are calculated and successfully verified through measurements of the scattering parameters and local temperature increases. In the chosen exposure configuration, the efficiency is 0.40 and the non‐uniformity degree is 39% for the 15 ml samples. For the 8 ml samples, the efficiency is 0.19 and a low non‐uniformity degree (15%) is found. Bioelectromagnetics 29:429–438, 2008. © 2008 Wiley‐Liss, Inc.
The mechanical transduction of physiological strength electric fields
Authors: Hart Francis X. 
Published: March 2008

AbstractIn this article it is proposed that electric fields of physiological strength (∼100 V/m) are transduced by the mechanical torque they exert on glycoproteins. The resulting mechanical signal is then transmitted to the cytoskeleton and propagated throughout the cell interior. This mechanical coupling is analyzed for transmembrane glycoproteins, such as integrins and the glycocalyx, and for glycoproteins in the extracellular matrix of cartilage. The applied torque is opposed by viscous fluid drag and restoring forces exerted by adjacent molecules in the membrane or cartilage. The resulting system represents a damped, driven harmonic oscillator. The amplitude of oscillation is constant at low frequencies, but falls off rapidly in the range 1–1000 Hz. The transition frequency depends on parameters such as the viscosity of the surrounding fluid and the restoring force exerted by the surrounding structure. The amplitude increases as the fourth power of the length of the transmembrane glycoproteins and as the square of the applied field. This process may operate in concert with other transduction mechanisms, such as the opening of voltage‐gated channels and electrodiffusion/osmosis for DC fields. Bioelectromagnetics 29:447–455, 2008. © 2008 Wiley‐Liss, Inc.
In vivo MR imaging of magnetically labeled mesenchymal stem cells transplanted into rat liver through hepatic arterial injection
Authors: Cai Jinhua , Zhang Xuemei , Wang Xin , Li Chuan , Liu Guanxin 
Published: March 2008

AbstractObjectiveThe aim of this study was to evaluate in vivo magnetic resonance imaging (MRI) for tracking the magnetically labeled mesenchymal stem cells (MSCs) transplanted into rat liver through hepatic arterial injection.Materials and MethodsMSCs, harvested from the bone marrow of Wistar rats and expanded by the adhesion method, were labeled with both Feridex and 4′,6‐diamidino‐2‐phenylindole (DAPI). Cell transplantation was performed by injection of 1 × 106 labeled cells (n = 20) or unlabeled cells (n = 10) via hepatic artery into rat livers treated with 2% carbon tetrachloride to induce acute liver necrosis. MR imaging was performed on a clinical 1.5 T MR scanner with a T2*‐weighted gradient‐echo sequence immediately before and at 1 h, 3 days, 7 days and 14 days after transplantation, and the signal‐to‐noise ratios (SNRs) were measured in liver, spleen, kidney and muscle. After MR examination, the animals were sacrificed, and the liver, kidney, lung and muscle were prepared for fluorescence observation and Prussian Blue staining.ResultsIn the group treated with labeled cells, the SNR of the liver after cell transplantation was 3.12 ± 0.43 at 1 h, 7.98 ± 1.05 at 3 days and 11.46 ± 1.41 at 7 days. These values were significantly lower than the pre‐transplantation SNR (14.40 ± 0.37). In the group treated with unlabeled cells, no significant difference could be found between after and before transplantation liver SNRs. Prussian Blue staining showed iron particles, contained within the cytoplasm and distributed in the liver parenchyma, which corresponded to the DAPI‐stained fluorescent nuclei under the fluorescence microscope.ConclusionThe magnetically labeled MSCs transplanted into rat liver through hepatic arterial injection can be detected and monitored in vivo with a 1.5 T clinical MR scanner for up to 7 days after cell transplantation. Copyright © 2008 John Wiley & Sons, Ltd.
Coexpression of the mu‐opioid receptor splice variant MOR1C and the vesicular glutamate transporter 2 (VGLUT2) in rat central nervous system
Authors: Schnell Stephen A. , Wessendorf Martin W. 
Published: March 2008

AbstractIt has been reported that mu‐opioid agonists depress glutamate release in some neurons but the specific receptor subtype mediating this effect is unclear. The purpose of the present study was to examine whether a particular mu‐opioid receptor (MOR) splice‐variant, MOR1C, is expressed in rat central nervous system (CNS) by terminals expressing the vesicular glutamate transporter2 (VGLUT2), a marker of glutamatergic neurons. Several MOR splice variants have been identified in mice and MOR1C appears mainly to be localized to fibers and terminals, from which most neurotransmitter release would be expected. In addition, VGLUT2 has been found in the CNS and antibodies to it are reliable markers for glutamatergic terminals. Using fluorescence immunohistochemistry and confocal microscopy to examine spatial relationships between MOR1C and VGLUT2, we found that MOR1C and VGLUT2 puncta were widely distributed throughout the rat CNS; moreover, many regions contained terminals that expressed both. Thus, it appears that coexpression of MOR1C and VGLUT2 is common in the rat CNS. We hypothesize that activation of MOR1C by mu‐opioid agonists at some glutamatergic terminals may be a mechanism by which glutamate release is inhibited. J. Comp. Neurol. 508:542–564, 2008. © 2008 Wiley‐Liss, Inc.
Visual, lateral line, and auditory ascending pathways to the dorsal telencephalic area through the rostrolateral region of the lateral preglomerular nucleus in cyprinids
Authors: Yamamoto Naoyuki , Ito Hironobu 
Published: March 2008

AbstractFiber connections of the rostrolateral region of the lateral preglomerular nucleus (PGlr) were studied by tract‐tracing methods in carp and goldfish. The PGlr receives fibers from the optic tectum, ventrolateral nucleus of semicircular torus, ventromedial thalamic nucleus, medial pretoral nucleus, anterior tuberal nucleus, subglomerular nucleus, and (unexpectedly) also from the retina. Dendritic morphology of tecto‐preglomerular neurons suggests that they receive retinal inputs. The PGlr can be further subdivided into dorsal (PGlr‐d) and ventral (PGlr‐v) zones, both of which are composed of somata and neuropil layers. Retinal and tectal fibers terminate mostly in the neuropil layer of the PGlr‐d with the retinal terminals concentrated medially and tectal terminals laterally. Lateral line toral fibers terminate mainly in a lateral portion and ventromedial thalamic fibers in a medial portion of the somata layer of the PGlr‐d. Auditory fibers from the medial pretoral nucleus and anterior tuberal nucleus terminate in the PGlr‐v. The central nucleus of the semicircular torus also projects sparse fibers to the PGlr‐v. The PGlr projects to the lateral, central, and medial parts of the dorsal telencephalic area, and the latter telencephalic part sends descending fibers to the PGlr. Differential distribution patterns of PGlr‐d and PGlr‐v fibers are noted within the dorsal telencephalic parts, suggesting that different sensory modalities may be represented in distinct regions at least to a certain degree. J. Comp. Neurol. 508:615–647, 2008. © 2008 Wiley‐Liss, Inc.
Genes, chromosomes and the development of testicular germ cell tumors of adolescents and adults
Authors: McIntyre Alan , Gilbert Duncan , Goddard Neil , Looijenga Leendart , Shipley Janet 
Published: March 2008

AbstractTesticular germ cell tumors (TGCTs) of adults and adolescents are thought to be derived from primordial germ cells or gonocytes. TGCTs develop postpuberty from precursor lesions known as intratubular germ cell neoplasia undifferentiated. The tumors can be divided into two groups based on their histology and clinical behavior; seminomas resemble primordial germ cells or gonocytes and nonseminomas resemble embryonic or extraembryonic tissues at various stages of differentiation. The most undifferentiated form of nonseminoma, embryonal carcinoma, resembles embryonic stem cells in terms of morphology and expression profiling, both mRNAs and microRNAs. Evidence supports both environmental factors and genetic predisposition underlying the development of TGCTs. Various models of development have been proposed and are discussed. In TGCTs, gain of material from the short arm of chromosome 12 is invariable: genes from this region include the proto‐oncogene KRAS, which has activating mutations in ∼10% of tumors or is frequently overexpressed. A number of different approaches to increase the understanding of the development and progression of TGCTs have highlighted the involvement of KIT, RAS/RAF/MAPK, STAT, and PI3K/AKT signaling. We review the role of these signaling pathways in this process and the potential influence of environmental factors in the development of TGCTs. © 2008 Wiley‐Liss, Inc.
Facies and depositional environments of the Devonian–Carboniferous succession of Iraq
Authors: Al‐Juboury Ali , Al‐Hadidy Aboosh 
Published: March 2008

AbstractFacies associations and depositional environments of the Late Devonian–Early Carboniferous succession in Iraq have been studied in several boreholes from north and northwestern Iraq. The >400 m‐thick succession comprises the Kaista, Ora, Harur and Raha formations which are composed generally of mixed siliciclastic‐carbonate facies. The Kaista Formation consists of sandstones intercalated with siltstones and calcareous shale that were deposited in a mixed fluvial‐marine environment. The Ora Formation is composed dominantly of black shale with subordinate sandstone and dolomite deposited in a shallow‐marine, sub‐tidal shelf environment. The Harur Formation is composed mainly of dolomite with subordinate shale and was deposited in a deep sub‐tidal environment. The Raha Formation consists mainly of marine shales intercalated with sandstones and concluded the Kaskaskia megasequence. The depositional setting is considered as a subsiding basin with a wide geographic distribution. It extended from the Ora region in the extreme north of Iraq to west and southwestern Iraq and reflects an epicontinental or epeiric sea setting on a homoclinal ramp inclined to the southeast. Copyright © 2008 John Wiley & Sons, Ltd.
Expression of glutamine synthetase and glutamate dehydrogenase in the latent phase and chronic phase in the kainate model of temporal lobe epilepsy
Authors: Hammer Janniche , Alvestad Silje , Osen Kirsten K. , Skare Øivind , Sonnewald Ursula , Ottersen Ole Petter 
Published: March 2008

AbstractIt has been suggested that astrocytic glutamate release or perturbed glutamate metabolism contributes to the proneness to epileptic seizures. Here we investigated whether astrocytic contents of the major glutamate degrading enzymes glutamine synthetase (GS) and glutamate dehydrogenase (GDH) decreases on moving from the latent phase (prior to seizures) to the chronic phase (after onset of seizures) in the kainate (KA) model of temporal lobe epilepsy. Western blotting and immunogold analysis of hippocampal formation indicated similar levels of GDH in the latent and chronic phases of KA injected rats and in corresponding controls. In contrast, the level of GS was increased in the latent phase compared with controls, as assessed by Western blots of whole hippocampal formation and subregions. The increase in GS paralleled that of glial fibrillary acidic protein (GFAP). Compared with the latent phase, the chronic phase revealed a lower level of GS (approaching control levels) but an unchanged GFAP content. The decrease in GS from latent to chronic phase was significant in whole hippocampal formation, dentate gyrus and CA3. It is concluded that kainate treated rats show an initial increase in GS, pari passu with the increase in GFAP, and a secondary decrease in GS that is not accompanied by a similar loss of GFAP. In a situation where glutamate catabolism is in high demand the secondary reduction in GS level may be sufficient to contribute to the seizure proneness that develops between the latent and chronic phases. © 2008 Wiley‐Liss, Inc.
Activation of olfactory and trigeminal cortical areas following stimulation of the nasal mucosa with low concentrations of S(−)‐nicotine vapor—An fMRI study on chemosensory perception
Authors: Albrecht Jessica , Kopietz Rainer , Linn Jennifer , Sakar Vehbi , Anzinger Andrea , Schreder Tatjana , Pollatos Olga , Brückmann Hartmut , Kobal Gerd , Wiesmann Martin 
Published: March 2008

AbstractApplied to the nasal mucosa in low concentrations, nicotine vapor evokes odorous sensations (mediated by the olfactory system) whereas at higher concentrations nicotine vapor additionally produces burning and stinging sensations in the nose (mediated by the trigeminal system). The objective of this study was to determine whether intranasal stimulation with suprathreshold concentrations of S(−)‐nicotine vapor causes brain activation in olfactory cortical areas or if trigeminal cortical areas are also activated. Individual olfactory detection thresholds for S(−)‐nicotine were determined in 19 healthy occasional smokers using a computer‐controlled air‐dilution olfactometer. Functional magnetic resonance images were acquired using a 1.5T MR scanner with applications of nicotine in concentrations at or just above the individual's olfactory detection threshold. Subjects reliably perceived the stimuli as being odorous. Accordingly, activation of brain areas known to be involved in processing of olfactory stimuli was identified. Although most of the subjects never or only rarely observed a burning or painful sensation in the nose, brain areas associated with the processing of painful stimuli were activated in all subjects. This indicates that the olfactory and trigeminal systems are activated during perception of nicotine and it is not possible to completely separate olfactory from trigeminal effects by lowering the concentration of the applied nicotine. In conclusion, even at low concentrations that do not consistently lead to painful sensations, intranasally applied nicotine activates both the olfactory and the trigeminal system. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Effect of dual growth factor delivery on chondrogenic differentiation of rabbit marrow mesenchymal stem cells encapsulated in injectable hydrogel composites
Authors: Park Hansoo , Temenoff Johnna S. , Tabata Yasuhiko , Caplan Arnold I. , Raphael Robert M. , Jansen John A. , Mikos Antonios G. 
Published: March 2008

AbstractAn injectable hydrogel composite consisting of oligo(poly(ethylene glycol)fumarate) (OPF) and gelatin microparticles has been developed as a novel carrier system for cells and growth factors. Rabbit marrow mesenchymal stem cells (MSCs) and gelatin microparticles (MPs) loaded with insulin‐like growth factor‐1 (IGF‐1), transforming growth factor‐β1 (TGF‐β1), or a combination of both growth factors were mixed with OPF, a poly(ethylene glycol)‐diacrylate crosslinker and the radical initiators ammonium persulfate and N,N,N′,N′‐tetramethylethylenediamine, and then crosslinked at 37°C for 8 min to form hydrogel composites. Hydrogel composites encapsulating rabbit marrow MSCs and blank MPs served as controls. At day 14, confocal fluorescent images of OPF hydrogels showed a strong aggregation of rabbit marrow MSCs when encapsulated with IGF‐1‐loaded MPs with or without TGF‐β1‐loaded MPs. Quantitative RT‐PCR results showed that rabbit marrow MSCs encapsulated with MPs loaded with TGF‐β1 or both TGF‐β1 and IGF‐1 had a significant increase in the expression of chondrocyte‐specific genes such as collagen type II and aggrecan at day 14 as compared with the control group. Specifically, samples with both TGF‐β1‐loaded MPs and IGF‐1‐loaded MPs exhibited a 121 ± 20‐fold increase of type II collagen gene expression and a 71 ± 24‐fold increase of aggrecan gene expression after 14 days of in vitro culture as compared with controls at day 0. These results suggest that hydrogel composites based on OPF and gelatin microparticles have great potential as carriers for MSCs and multiple growth factors for cartilage tissue engineering applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009