bluuebunny/crossref_metadata_2025 huggingface dataset:
Creating Linkages between the Labour Market and Agricultural Higher Education in Iran
Authors: Movahedi Reza , Saadi Heshmatollah , Farani Ahmad Yaghoubi
Published: August 2011

Employment of agriculture graduates in Iran is a major problem that needs to be addressed. There are three main issues: lack of robust strategies for linking agricultural higher education and the labour market, the lack of relevance of agricultural curricula to the real needs of the labour market, and diminishing levels of government services for the recruitment of graduates. The aim of the research reported in this paper was to identify effective strategies and mechanisms for establishing and maintaining partnerships between academia and the labour market, with a view to improving the employment prospects of agriculture graduates. The study used both quantitative and qualitative data and focused on agriculture graduates and faculty members of the Bu-Ali-Sina University in Iran and employers in different sectors of agriculture. Data were collected using a questionnaire survey and semi-structured interviews. The results indicate that six key mechanisms – managerial, support, information provision, research, collaboration and spatial (infrastructure facilities) – could help to link the university more effectively with the labour market.
Single Crystal Charge Density Studies of Thermoelectric Material Indium Antimonide
Authors: Muthaian Charles Robert , Subha Bandarinathan , Saravanan Ramachandran
Published: August 2011

density distribution using the single crystal X-ray intensity data. The charge density of this material has been studied including and excluding the quasi-forbidden h+k +l = 4n+2 type reflections using the maximum entropy method (MEM). Both the pictorial and numerical results of the experimental electron density show mixed ionic and covalent character in InSb. The use of InSb as a thermoelectric material is supported through charge density analysis.
The Effect of Substrate Clamping on Laminated Magnetoelectric Composite
Authors: Guo Hong-Li , Li Hai-Min , Li Xue-Dong , Xiao Ding-Quan , Zhu Jian-Guo
Published: August 2011

laminated composites on silicon or magnesium oxide substrates. The magnetoelectric voltage coefficient is calculated as function of interface coupling factor k, volume ratio of piezoelectrics to piezomagnetic, and volume ratio of substrates to composite. It was found that the magnetoelectric voltage coefficient decreases as the interface coupling factor k weakens, while the volume ratio of piezoelectrics to piezomagnetic vmax shifts to lead-rich compositions. The magnetoelectric voltage coefficient of laminated composites decreases sharply with increasing substrates thickness ratio, which shows strong substrate clamping effect to the magnetoelectric composite.
Numerical Solutions of Systems of High-Order Linear Differential-Difference Equations with Bessel Polynomial Bases
Authors: Yüzbași Șuayip , Șahin Niyazi , Yıldırımb Ahmet
Published: August 2011

In this paper, a numerical matrix method, which is based on collocation points, is presented for the approximate solution of a system of high-order linear differential-difference equations with variable coefficients under the mixed conditions in terms of Bessel polynomials. Numerical examples are included to demonstrate the validity and applicability of the technique and comparisons are made with existing results. The results show the efficiency and accuracy of the present work. All of the numerical computations have been performed on computer using a program written in MATLAB v7.6.0 (R2008a).
Reductions and Solutions of Two Types of Coupled Nonlinear Evolution Equations in Optical Fibers and Fluid Dynamics
Authors: Liu Li-Cai , Tian Bo , Qin Bo , Lü Xing , Lin Zhi-Qiang , Liu Wen-Jun
Published: August 2011

Under investigation in this paper are the coupled nonlinear Schrödinger equations (CNLSEs) and coupled Burgers-type equations (CBEs), which are, respectively, a model for certain birefringent optical fibers Raman-scattering, Kerr and gain/loss effects, and a generalized model in fluid dynamics. Special attention should be paid to the existing claim that the solitons for the CNLSEs do not exist. Through certain dependent-variable transformations, the CNLSEs are reduced to a Manakov system and the CBEs are linearized. In that way, some new solutions of the CNLSEs and CBEs are obtained via symbolic computation. Especially the one-dark-soliton-like solutions for the CNLSEs have been found, against the existing claim.
Shape Matters: Anisotropy of the Morphology of Inorganic Colloidal Particles – Synthesis and Function
Authors: Polarz Sebastian
Published: August 2011

The shape of a crystalline particle can be defined by a characteristic set and abundance of surfaces corresponding to the lattice planes [hkl] of the crystal. The structure, the density, the electronic system, and the energy of each [hkl]‐surface is different from the others. Consequently, every morphology is also characterized by a unique free energy compared to alternative shapes at a constant surface‐to‐volume ratio. Using tools from geometrical crystallography, an attempt is made to describe the systems in terms of morphology energy landscapes. It is obvious that, similar to surface phenomena, shape‐related properties are also apparent, in particular at the nanometer‐scale. However, morphology effects go much beyond surface effects. It will be shown that not only catalytic properties differ with particle shape, but also magnetic, optical, electronic, mechanical, and self‐assembly properties are influenced. In addition, analytical methods are highlighted that are suitable for the determination of the shape of the particles. Different methods are discussed that can be found for the synthesis of anisotropic metal and metal‐oxide nanoparticles.
Multi‐level modeling of aspects associated with poor mental health in a sample of prehospital emergency professionals
Authors: Arial Marc , Wild Pascal , Benoit Damien , Chouaniere Dominique , Danuser Brigitta
Published: August 2011

Background

The goal of this paper is to investigate the respective influence of work characteristics, the effort–reward ratio, and overcommitment on the poor mental health of out‐of‐hospital care providers.

Methods

333 out‐of‐hospital care providers answered a questionnaire that included queries on mental health (GHQ‐12), demographics, health‐related information and work characteristics, questions from the Effort–Reward Imbalance Questionnaire, and items about overcommitment. A two‐level multiple regression was performed between mental health (the dependent variable) and the effort–reward ratio, the overcommitment score, weekly number of interventions, percentage of non‐prehospital transport of patients out of total missions, gender, and age. Participants were first‐level units, and ambulance services were second‐level units. We also shadowed ambulance personnel for a total of 416 hr.

Results

With cutoff points of 2/3 and 3/4 positive answers on the GHQ‐12, the percentages of potential cases with poor mental health were 20% and 15%, respectively. The effort–reward ratio was associated with poor mental health (P < 0.001), irrespective of age or gender. Overcommitment was associated with poor mental health; this association was stronger in women (β = 0.054) than in men (β = 0.020). The percentage of prehospital missions out of total missions was only associated with poor mental health at the individual level.

Conclusions

Emergency medical services should pay attention to the way employees perceive their efforts and the rewarding aspects of their work: an imbalance of those aspects is associated with poor mental health. Low perceived esteem appeared particularly associated with poor mental health. This suggests that supervisors of emergency medical services should enhance the value of their employees' work. Employees with overcommitment should also receive appropriate consideration. Preventive measures should target individual perceptions of effort and reward in order to improve mental health in prehospital care providers. Am. J. Ind. Med. 54:847–857, 2011. © 2011 Wiley Periodicals, Inc.
Predicting the open conformations of protein kinases using molecular dynamics simulations
Authors: Bjarnadottir Una , Nielsen Jens Erik
Published: August 2011

Protein kinases (PK) control phosphorylation in eukaryotic cells, and thereby regulate metabolic pathways, cell cycle progression, apoptosis, and transcription. Consequently, there is significant interest in manipulating PK activity and treat diseases by using small‐molecule drugs. All PK catalytic domains undergo large conformational changes as a result of substrate binding and phosphorylation. The “closed” state of a PK catalytic domain is the only state able to phosphorylate the target substrate, which makes the two other observed states (the “open” and the “intermediate” states) interesting drug targets. We investigate whether molecular dynamics (MD) simulations starting from the closed state of the catalytic domain of protein kinase A (C‐PKA) can be used to produce realistic structures representing the intermediate and/or open conformation of C‐PKA, because this would allow for drug docking calculations and drug design using MD snapshots. We perform 36 ten‐nanosecond MD simulations starting from the closed conformation [PDB ID: ATP] of C‐PKA in various liganded and phosphorylated states. The results show that MD simulations are capable of reproducing the open conformation of C‐PKA with good accuracy within 1 ns of simulation as measured by Cα root mean square deviations (RMSDs) and RMSDs of atoms defining the ATP‐binding pocket. Importantly, we are able to show that even without knowledge of the structure of the open form of C‐PKA, we can identify the MD snapshots resembling the open conformation most using the open structure of a different PK displaying only 23% sequence identity to C‐PKA. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 65–72, 2012.
Effects of copolypeptides on amyloid fibrillation of hen egg‐white lysozyme
Authors: Wen Wen‐Sing , Lai Jun‐Kun , Lin Yu‐Jiun , Lai Chia‐Min , Huang Yun‐Chiao , Wang Steven S.‐S. , Jan Jeng‐Shiung
Published: August 2011

The fibrillation of hen egg‐white lysozyme (HEWL) in the absence and presence of simple, unstructured D,L‐lysine‐co‐glycine (D,L‐Lys‐co‐gly) and D,L‐lysine‐co‐L‐phenylalanine (D,L‐Lys‐co‐Phe) copolypeptides was studied by using a variety of analytical techniques. The attenuating and decelerating effects on fibrillation are significantly dependent on the polypeptide concentration and the composition ratios in the polypeptide chain. Interestingly, D,L‐Lys‐co‐gly and D,L‐Lys‐co‐Phe copolypeptides with the same composition ratio have comparable attenuating effects on fibrillation. The copolypeptide with highest molar fraction of glycine residue exhibits the strongest suppression of HEWL fibrillation. The copolypeptide has the highest hydrophobic interacting capacity due to the more molar ratio of apolar monomer in the polymer backbone. The major driving forces for the association of HEWL and copolypeptides are likely to be hydrogen bonding and hydrophobic interactions, and these interactions reduce the concentration of free protein in solution available to proceed to fibrillation, leading to the increase of lag time and attenuation of fibrillation. The results of this work may contribute to the understanding of the molecular factors affecting amyloid fibrillation and the molecular mechanism(s) of the interactions between the unstructured polypeptides and the amyloid proteins. © 2011 Wiley Periodicals, Inc. Biopolymers 97:107–116, 2012.
Polyethylene glycol behaves like weak organic solvent
Authors: Hirano Atsushi , Shiraki Kentaro , Arakawa Tsutomu
Published: August 2011

Effect of polyethylene glycol (PEG) on protein solubility has been primarily ascribed to its large hydrodynamic size and thereby molecular crowding effect. However, PEG also shows characteristics of organic solvents. Here, we have examined the solubility of glycine and aliphatic and aromatic amino acids in PEG solutions. PEG400, PEG4000, and PEG20000 decreased the solubility of glycine, though to a much smaller magnitude than the level achieved by typical organic solvents, including ethanol and dimethyl sulfoxide. PEG4000 showed varying degree of interactions with amino acid side chains. The free energy of aliphatic side chains marginally increased by the addition of PEG4000, indicating their weak unfavorable interactions. However, it significantly decreased the free energy of the aromatic side chains and hence stabilized them. Thus, it was concluded that PEG behaves like weak organic solvents; namely PEG destabilized (interacted unfavorably with) polar and charged groups and stabilized (interacted favorably with) aromatic groups. Interestingly, the interaction of PEG20000, but neither PEG400 nor PEG4000, with glycine resulted in phase separation under the saturated concentration of glycine. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 117–122, 2012.
Validation of long‐term primary neuronal cultures and network activity through the integration of reversibly bonded microbioreactors and MEA substrates
Authors: Biffi Emilia , Menegon Andrea , Piraino Francesco , Pedrocchi Alessandra , Fiore Gianfranco B. , Rasponi Marco
Published: August 2011

In vitro recording of neuronal electrical activity is a widely used technique to understand brain functions and to study the effect of drugs on the central nervous system. The integration of microfluidic devices with microelectrode arrays (MEAs) enables the recording of networks activity in a controlled microenvironment. In this work, an integrated microfluidic system for neuronal cultures was developed, reversibly coupling a PDMS microfluidic device with a commercial flat MEA through magnetic forces. Neurons from mouse embryos were cultured in a 100 µm channel and their activity was followed up to 18 days in vitro. The maturation of the networks and their morphological and functional characteristics were comparable with those of networks cultured in macro‐environments and described in literature. In this work, we successfully demonstrated the ability of long‐term culturing of primary neuronal cells in a reversible bonded microfluidic device (based on magnetism) that will be fundamental for neuropharmacological studies. Biotechnol. Bioeng. 2012;109: 166–175. © 2011 Wiley Periodicals, Inc.
Recent application of analytical methods to phase I and phase II drugs development: a review
Authors: Locatelli Marcello , Governatori Luciana , Carlucci Giuseppe , Genovese Salvatore , Mollica Adriano , Epifano Francesco
Published: August 2011

Drug development is a time‐consuming and costly process. It is usually divided into four phases, although it is not always possible to draw a sharp line between the various stages. In phase I and II there are many molecules investigate and it is necessary to analyze all of them in a short period of time, with lower costs, and with high‐throughput assay. During phase I relevant chemical–physical parameters like the acid dissociation constant, lipophilicity, solubility and stability must be analyzed. Classic techniques such as ‘shake‐flask’ can be used, but instrumental analytical methods such as HPLC may be helpful to improve and enhance the productivity and reproducibility of the results. During phase II the activity of a drug and factors that may have an influence on it, like metabolic profile and transformations, impurities and plasma biding proteins, must be considered. In this field, recent hyphenated analytical methods, such as LC‐MS/MS, GC‐MS/MS or more complex couplings, can provide more complete information. The aim of this review is to report the processes required for the validation of drug efficacy with reference to the description of ‘classic’ and modern techniques used. Copyright © 2011 John Wiley & Sons, Ltd.
Magnesium deficiency up‐regulates Myod expression in rat skeletal muscle and C2C12 myogenic cells
Authors: Furutani Yuuma , Funaba Masayuki , Matsui Tohru
Published: August 2011

Magnesium (Mg) deficiency induces the production of free radicals, increases cytosolic ionized calcium concentration, and modulates the function of skeletal muscle in rats. The present study examined the effects of Mg deficiency on the gene expression of molecules related to myogenesis in the gastrocnemius muscle as well as in C2C12 myogenic cells. Ingestion of an Mg‐deficient diet resulted in a lower weight of the gastrocnemius muscle and higher concentration of muscular TBARSs, an index of oxidative stress. Mg deficiency also enhanced the expression of Myod and myogenin. In vivo effects of Mg deficiency on myogenic gene expression were partially reproduced in in vitro C2C12 cells; expression of Myod was up‐regulated by a mixed culture of myoblasts and myotubes with Mg‐deficient medium, which related to the simultaneous up‐regulation of Myhc IIb, a myotube‐specific protein. The culture with Mg‐deficient medium did not increase the gene transcript level of HO‐1, another marker of oxidative stress, suggesting that Mg deficiency‐induced Myod expression does not result from oxidative stress. Furthermore, oxidative stress induced by hydrogen peroxide did not increase Myod expression, whereas the expression of Myod, myogenin and Myhc IIb was decreased by oxidative stress from the initial phase of differentiation. The effects of Mg deficiency depended on the stages of myogenesis; myoblast culture in Mg‐deficient differentiation medium did not affect the expression of Myod and Myhc IIb. The present study revealed stage‐dependent effects of Mg deficiency on myogenesis. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of indolizidines from optically pure α‐amino acids via stereocontrolled rhodium‐catalyzed hydroformylation of N‐allylpyrroles
Authors: Lazzaroni Raffaello , Settambolo Roberta
Published: August 2011

Indolizidine alkaloids have attracted considerable attention because of their vast array of structural diversity and varied biological activity. This article relates the results that we obtained in the field of the total synthesis of indolizidines from α‐amino acids, based on the rhodium‐catalyzed hydroformylation of N‐allylpyrroles intermediates. The formed pyrrolylbutanals undergo an intramolecular cyclodehydration to 5,6‐dihydroindolizines, which are fully hydrogenated to indolizidines. All reaction sequences are stereocontrolled: indeed, the chiral center in the starting amino acid is transferred into 5,6‐dihydroindolizine moiety with complete stereochemical integrity and the new stereogenic center at C9 carbon atom in the final indolizidines is generated in only one configuration.Chirality, 2011. © 2011 Wiley‐Liss, Inc.
Adenosine A2A receptor in the monkey basal ganglia: Ultrastructural localization and colocalization with the metabotropic glutamate receptor 5 in the striatum
Authors: Bogenpohl James W. , Ritter Stefanie L. , Hall Randy A. , Smith Yoland
Published: August 2011

The adenosine A2A receptor (A2AR) is a potential drug target for the treatment of Parkinson's disease and other neurological disorders. In rodents, the therapeutic efficacy of A2AR modulation is improved by concomitant modulation of the metabotropic glutamate receptor 5 (mGluR5). To elucidate the anatomical substrate(s) through which these therapeutic benefits could be mediated, pre‐embedding electron microscopy immunohistochemistry was used to conduct a detailed, quantitative ultrastructural analysis of A2AR localization in the primate basal ganglia and to assess the degree of A2AR/mGluR5 colocalization in the striatum. A2AR immunoreactivity was found at the highest levels in the striatum and external globus pallidus (GPe). However, the monkey, but not the rat, substantia nigra pars reticulata (SNr) also harbored a significant level of neuropil A2AR immunoreactivity. At the electron microscopic level, striatal A2AR labeling was most commonly localized in postsynaptic elements (58% ± 3% of labeled elements), whereas, in the GPe and SNr, the labeling was mainly presynaptic (71% ± 5%) or glial (27% ± 6%). In both striatal and pallidal structures, putative inhibitory and excitatory terminals displayed A2AR immunoreactivity. Striatal A2AR/mGluR5 colocalization was commonly found; 60–70% of A2AR‐immunoreactive dendrites or spines in the monkey striatum coexpress mGluR5. These findings provide the first detailed account of the ultrastructural localization of A2AR in the primate basal ganglia and demonstrate that A2AR and mGluR5 are located to interact functionally in dendrites and spines of striatal neurons. Together, these data foster a deeper understanding of the substrates through which A2AR could regulate primate basal ganglia function and potentially mediate its therapeutic effects in parkinsonism. J. Comp. Neurol., 2012;520:570–589. © 2011 Wiley Periodicals, Inc.
Heterogeneity in dendritic morphology of moth antennal lobe projection neurons
Authors: Namiki Shigehiro , Kanzaki Ryohei
Published: August 2011

A population of projection neurons (PNs) in the antennal lobe (AL) integrates sensory information from the antenna and is essential for processing odor information in the insect brain. We examined the anatomy of this neuronal population in the brain of the silkmoth Bombyx mori. Using intracellular dye injection, we labeled a total of 246 PNs and systematically analyzed their morphological features, including the soma position, antennocerebral tract, and number of innervating glomeruli. For example, we analyzed PNs that had somata in the different cell clusters, innervated overlapping but different groups of glomeruli, and ran through different pathways. We also identified glomeruli innervated by PNs using a previously established procedure that first classifies glomeruli into regional groups and then identifies individual glomeruli. We analyzed uniglomerular PNs (75.6% of the total) and found heterogeneity in the dendritic morphology of the PNs that was dependent on the regions and/or the innervating glomeruli. For example, most PNs innervating the macroglomerular complex did not have extraglomerular processes, whereas most PNs innervating ordinary glomeruli did. Moreover, PNs innervating the toroid glomerulus showed heterogeneity in their dendritic morphology. These PNs had dendritic arborization in different areas within the glomerulus. We found that, in some cases, the innervation pattern of the PN dendrite correlated with individual variation in the glomerular organization. These results indicate that PNs are not homogeneous populations, and in some cases morphological heterogeneity in PNs correlated with change in glomerular organization in the silkmoth AL. J. Comp. Neurol. 519:3367–3386, 2011. © 2011 Wiley‐Liss, Inc.
Sacral neural crest‐derived cells enter the aganglionic colon of Ednrb−/− mice along extrinsic nerve fibers
Authors: Erickson Christopher S. , Zaitoun Ismail , Haberman Kathryn M. , Gosain Ankush , Druckenbrod Noah R. , Epstein Miles L.
Published: August 2011

Both vagal and sacral neural crest cells contribute to the enteric nervous system in the hindgut. Because it is difficult to visualize sacral crest cells independently of vagal crest, the nature and extent of the sacral crest contribution to the enteric nervous system are not well established in rodents. To overcome this problem we generated mice in which only the fluorescent protein‐labeled sacral crest are present in the terminal colon. We found that sacral crest cells were associated with extrinsic nerve fibers. We investigated the source, time of appearance, and characteristics of the extrinsic nerve fibers found in the aganglionic colon. We observed that the pelvic ganglion neurons contributed a number of extrinsic fibers that travel within the hindgut between circular and longitudinal muscles and within the submucosa and serosa. Sacral crest‐derived cells along these fibers diminished in number from fetal to postnatal stages. A small number of sacral crest‐derived cells were found between the muscle layers and expressed the neuronal marker Hu. We conclude that sacral crest cells enter the hindgut by advancing on extrinsic fibers and, in aganglionic preparations, they form a small number of neurons at sites normally occupied by myenteric ganglia. We also examined the colons of ganglionated preparations and found sacral crest‐derived cells associated with both extrinsic nerve fibers and nascent ganglia. Extrinsic nerve fibers serve as a route of entry for both rodent and avian sacral crest into the hindgut. J. Comp. Neurol. 520:620–632, 2012. © 2011 Wiley Periodicals, Inc.
A methodology for real‐time self‐organized autonomous clustering in mobile ad hoc networks
Authors: Kakuda Yoshiaki , Ohta Tomoyuki , Oda Ryotaro
Published: August 2011

In order to realize hierarchical routings that should be executed in large‐scaled mobile ad hoc networks that vary their topologies considerably with time, we have developed autonomous clustering with high scalability and adaptability. In autonomous clustering, an entire network is divided into disjoint subnetworks (called clusters), and they are maintained by periodically sending messages within the clusters. This paper proposes real‐time self‐organizing autonomous clustering, in which interval and power for transmitting such messages are dynamically changed depending on variation of mobility and density of the clusters. Because their mobility and density can be estimated by local information obtained in the clusters, and according to their respective change the clusters are self‐organized in real‐time way, the proposed real‐time self‐organizing autonomous clustering can contribute to enhancement of its scalability and adaptability. Copyright © 2011 John Wiley & Sons, Ltd.
Context‐aware web search using dynamically weighted information fusion
Authors: Anderson Nicole
Published: August 2011

Web search has become a cornerstone tool for Internet users. The information one is able to retrieve quickly with commercial tools is awe inspiring, yet average users still remain frustrated with finding information that is truly relevant to them. In our research, we seek to show that if we utilize key pieces of information about a user and their current context, we can provide more accurate results. We do this by exploring context data, using query enhancement techniques, and appropriately fusing the results to provide the best ordering when presenting the results to the user. Context data includes a user's personal calendar, location, preferences, personal vocabulary, and peer recommendations. Query enhancement involves utilizing relevant contextual information to decorate a user's query text to produce a more focused query. Information fusion allows the query results to be compared and re‐ordered using contextual data by utilizing either a sum of products, a Bayesian technique, or a combination of the two. We find that by combining these methods, we are able to significantly enhance the search results. We have performed a case study and present the results here. Copyright © 2011 John Wiley & Sons, Ltd.
MR‐search: massively parallel heuristic search
Authors: Schütt Thorsten , Reinefeld Alexander , Maier Robert
Published: August 2011

MR‐Search is a framework for massively parallel heuristic search. Based on the MapReduce paradigm, it efficiently utilizes all available resources: processors, memories, and disks. MR‐Search uses OpenMP on shared memory systems, Message Passing Interface on clusters with distributed memory, and a combination of both on clusters with multi‐core processors. Large graphs that do not fit into the main memory can be efficiently processed with an out‐of‐core variant. We implemented two node expansion strategies in MR‐Search: breadth‐first frontier search and breadth‐first iterative deepening A*. With breadth‐first frontier search, we computed large and powerful table‐driven heuristics, so‐called pattern databases that exceed the main memory capacity. These pattern databases were then used to solve random instances of the 24‐puzzle with breadth‐first iterative deepening A* on systems with up to 4093 processor cores. MR‐Search is conceptually simple. It takes care of data partitioning, process scheduling, out‐of‐core data merging, communication, and synchronization. Application developers benefit from the parallel computational capacity without having the burden of implementing parallel application code. Copyright © 2011 John Wiley & Sons, Ltd.
Hybrid Architectures from 3D Aligned Arrays of Multiwall Carbon Nanotubes and Nanoparticulate LiCoPO4: Synthesis, Properties and Evaluation of Their Electrochemical Performance as Cathode Materials in Lithium Ion Batteries
Authors: Schneider Jörg J. , Khanderi Jayaprakash , Popp Alexander , Engstler Jörg , Tempel Hermann , Sarapulova Angelina , Bramnik Natalia N. , Mikhailova Daria , Ehrenberg Helmut , Schmitt Ljubomira A. , Dimesso Lucangelo , Förster Christoph , Jaegermann Wolfram
Published: August 2011

Hybrid materials composed of LiMPO4 (M = Fe or Co) with multiwalled carbon nanotubes (MCNTs) were synthesized by tethering lithium phosphoolevins on isolated stochastically disordered MWCNTs as well as on ordered 3D MWCNT arrays via solution based impregnation routes. Ordered 3D arrays of MWCNT monoliths comprising MWCNTs with nominal tube diameters of 60 and 200 nm were synthesized by a catalyst free, template based method, with porous aluminum oxide (PAOX) acting as a template. Consecutive selectiveetching processes gave free standing aligned 3D carbon nanotube (CNT) architectures that were used as supporting cathode structures for electroactive LiCoPO4. LiCoPO4 nanoparticle suspensions derived from an ethanol based organic phosphate source turned out to be superior for the tethering of LiCoPO4 nanoparticles onto the 3D aligned CNT arrays compared to an aqueous based tethering route, thus giving hybrid materials with better electrochemical battery performance compared to materials generated by the latter method. Li ion extraction within the ordered 3D CNT/LiCoPO4 composites seems to be a two‐step process and the Li intercalation a one‐step process, highlighting the enhanced kinetics of the Li insertion process in the 3D CNT/LixCoPO4 composite in comparison to a particulate mixture of LixCoPO4 that is typically present in a conventional carbon/LiCoPO4 cathode composite system.
A Crystallographic and Mo K‐Edge XAS Study of Molybdenum Oxo Bis‐, Mono‐, and Non‐Dithiolene Complexes – First‐Sphere Coordination Geometry and Noninnocence of Ligands
Authors: Samuel Prinson P. , Horn Sebastian , Döring Alexander , Havelius Kajsa G. V. , Reschke Stefan , Leimkühler Silke , Haumann Michael , Schulzke Carola
Published: August 2011

Ten square‐based pyramidal molybdenum complexes with different sulfur donor ligands, that is, a variety of dithiolenes and sulfides, were prepared, which mimic coordination motifs of the molybdenum cofactors of molybdenum‐dependent oxidoreductases. The model compounds were investigated by Mo K‐edge X‐ray absorption spectroscopy (XAS) and (with one exception) their molecular structures were analyzed by X‐ray diffraction to derive detailed information on bond lengths and geometries of the first coordination shell of molybdenum. Only small variations in Mo=O and Mo–S bond lengths and their respective coordination angles were observed for all complexes including those containing Mo(CO)2 or Mo(μ‐S)2Mo motifs. XAS analysis (edge energy) revealed higher relative oxidation levels in the molybdenum ion in compounds with innocent sulfur‐based ligands relative to those in dithiolene complexes, which are known to exhibit noninnocence, that is, donation of substantial electron density from ligand to metal. In addition, longer average Mo–S and Mo=O bonds and consequently lower ν(Mo=O) stretching frequencies in the IR spectra were observed for complexes with dithiolene‐derived ligands. The results emphasize that the noninnocent character of the dithiolene ligand influences the electronic structure of the model compounds, but does not significantly affect their metal coordination geometry, which is largely determined by the Mo(IV) or (V) ion itself. The latter conclusion also holds for the molybdenum site geometries in the oxidized MoVI cofactor of DMSO reductase and the reduced MoIV cofactor of arsenite oxidase. The innocent behavior of the dithiolene molybdopterin ligands observed in the enzymes is likely to be related to cofactor–protein interactions.
A Family of Thiazolium Salt Derived N‐Heterocyclic Carbenes (NHCs) for Organocatalysis: Synthesis, Investigation and Application in Cross‐Benzoin Condensation
Authors: Piel Isabel , Pawelczyk Marius D. , Hirano Keiichi , Fröhlich Roland , Glorius Frank
Published: August 2011

A family of thiazolium salt derived N‐heterocyclic carbenes (NHCs) bearing sterically demanding aryl substituents on the nitrogen and with varying backbone substitution patterns have been synthesized. Investigation of the catalytic activity of these NHCs in a number of benzoin‐type coupling reactions revealed markedly different levels of reactivity and selectivity. To elucidate the underlying factors leading to differences in reactivity, a study of the electronic and steric properties of these NHC catalysts was conducted. By using the best catalyst in this study, the intermolecular cross‐benzoin condensation reaction was explored in more detail.
A novel concept of dielectrophoretic engine oil filter
Authors: Shen Yueyang , Elele Ezinwa , Khusid Boris
Published: August 2011

A novel concept of an alternating current (AC) dielectrophoretic filter with a three‐dimensional electrode array is presented. A filter is constructed by winding into layers around the core tube two sheets of woven metal wire‐mesh with several sheets of woven insulating wire‐mesh sandwiched in between. Contrary to conventional dielectrophoretic devices, the proposed design of electrodes generates a high‐gradient field over a large working volume by applying several hundred volts at a standard frequency of 60 Hz. The operating principle of filtration is based on our recently developed method of AC dielectrophoretic gating for microfluidics. The filtration efficiency is expressed in terms of two non‐dimensional parameters, which describe the combined influence of the particle polarizability and size, the oil viscosity and flow rate, and the field gradient on the particle captivity. The proof‐of‐concept is tested by measuring the single‐pass performance of two filters on positively polarized particles dispersed in engine oil: spherical glass beads, fused aluminum oxide powder, and silicon metal powder, all smaller than the mesh opening. The results obtained are used to consider the potential of using AC dielectrophoretic filtration and provide critical design guidelines for the development of a filter based on the retention capability of challenge particles.
Fluid streaming above interdigitated electrodes in dielectrophoresis experiments
Authors: Stanke Sandra , Bier Frank. F. , Hölzel Ralph
Published: August 2011

For the investigation of alternating current electrokinetic effects, a system is presented that allows for the simultaneous observation of fluid flow above and around microelectrodes in all three directions in space. Beside the usual microscopical view from top, lateral observation through the same objective is made possible by two small mirrors that are placed next to the electrodes. Fluid flow and movement of fluorescent nanoparticles above interdigitated electrodes are monitored by fluorescence microscopy and digital imaging and are further analysed by image processing. Field frequencies are varied from 10 Hz to 1 GHz at up to 10Vrms. Electrical conductivity of the fluid is monitored in situ in the actual measuring chamber.
Evaluation of Bayesian spatiotemporal latent models in small area health data
Authors: Choi Jungsoon , Lawson Andrew B. , Cai Bo , Hossain Md. Monir
Published: August 2011

Health outcomes are linked to air pollution and demographic or socioeconomic factors that vary across space and time. Thus, it is often found that relative risks in space–time health data have locally different temporal patterns. In such cases, latent modeling is useful in the disaggregation of risk profiles. In particular, spatiotemporal mixture models can help to isolate spatial clusters in which each has a homogeneous temporal pattern in relative risks. In mixture modeling, various weight structures can be used, and two situations can be considered: the number of underlying components is known or unknown. In this paper, we compare spatiotemporal mixture models with different weight structures in both situations. In addition, spatiotemporal Dirichlet process mixture models are compared with them when the number of components is unknown. For comparison, we propose a set of spatial cluster detection diagnostics based on the posterior distribution of the weights. We also develop new accuracy measures to assess the recovery of true relative risks. Based on the simulation study, we examine the performance of various spatiotemporal mixture models in terms of proposed methods and goodness‐of‐fit measures. We apply our models to a county‐level chronic obstructive pulmonary disease data set from the state of Georgia. Copyright © 2011 John Wiley & Sons, Ltd.
The intrinsic fusogenicity of glioma cells as a factor of transformation and progression in the tumor microenvironment
Authors: Mercapide Javier , Rappa Germana , Lorico Aurelio
Published: August 2011

We have previously reported in vitro heterotypic fusion of glioma cells with neural progenitor cells, producing tetraploid cells expressing genetic complements of each partner. Herein, we investigated the fusogenicity of glioma cells. In 1:1 cocultures of single‐labeled cells, U87MG cells presented high frequency of homotypic fusogenic events, producing cells that coexpressed both fluorescent proteins. Six percent of the total cells had 8n DNA content, consistent with the finding that the double‐labeled cells were actively proliferating. In coculture with fibroblasts, glioma cell fusogenicity resulted in viable reprogrammed cells, thus emerging as a plausible source of tumor cell heterogeneity. As for heterotypic fusion to happen, glioma cells have to establish direct contact with other cells, the effect of stroma on glioma cells was analyzed. Proliferation assays and array analysis of cancer‐related pathways established a promalignant effect of stroma. This effect was mediated by fibronectin and was nearly completely abolished by inhibitors of the epidermal‐growth‐factor receptor. That stroma elicited transduction signaling through the mitogen‐activated‐protein kinase/extracellular‐signal‐regulated kinase pathway, which is linked to increased tumor cell migration through extracellular matrix, suggested that glioma cells may actively approach nontumor cells in stromal niches. According to these results, the fusogenicity of glioma cells emerged as an inherent factor for phenotypic changes leading to glioma progression.
Efficacy of the human papillomavirus (HPV)‐16/18 AS04‐adjuvanted vaccine in women aged 15–25 years with and without serological evidence of previous exposure to HPV‐16/18
Authors: Szarewski A. , Poppe W.A.J. , Skinner S.R. , Wheeler C.M. , Paavonen J. , Naud P. , Salmeron J. , Chow S.‐N. , Apter D. , Kitchener H. , Castellsagué X. , Teixeira J.C. , Hedrick J. , Jaisamrarn U. , Limson G. , Garland S. , Romanowski B. , Aoki F.Y. , Schwarz T.F. , Bosch F.X. , Harper D.M. , Hardt K. , Zahaf T. , Descamps D. , Struyf F. , Lehtinen M. , Dubin G. ,   for the HPV PATRICIA Study Group
Published: August 2011

In the Phase III PATRICIA study (NCT00122681), the human papillomavirus (HPV)‐16/18 AS04‐adjuvanted vaccine (Cervarix®, GlaxoSmithKline Biologicals) was highly efficacious against HPV‐16/18 infections and precancerous lesions in women HPV‐16/18 deoxyribose nucleic acid (DNA) negative and seronegative at baseline. We present further data on vaccine efficacy (VE) against HPV‐16/18 in the total vaccinated cohort including women who may have been exposed to HPV‐16/18 infection before vaccination. In women with no evidence of current or previous HPV‐16/18 infection (DNA negative and seronegative), VE was 90.3% (96.1% confidence interval: 87.3–92.6) against 6‐month persistent infection (PI), 91.9% (84.6–96.2) against cervical intraepithelial neoplasia (CIN)1+ and 94.6% (86.3–98.4) against CIN2+ [97.7% (91.1–99.8) when using the HPV type assignment algorithm (TAA)]. In women HPV‐16/18 DNA negative but with serological evidence of previous HPV‐16/18 infection (seropositive), VE was 72.3% (53.0–84.5) against 6‐month PI, 67.2% (10.9–89.9) against CIN1+, and 68.8% (−28.3–95.0) against CIN2+ [88.5% (10.8–99.8) when using TAA]. In women with no evidence of current HPV‐16/18 infection (DNA negative), regardless of their baseline HPV‐16/18 serological status, VE was 88.7% (85.7–91.1) against 6‐month PI, 89.1% (81.6–94.0) against CIN1+ and 92.4% (84.0–97.0) against CIN2+ [97.0% (90.6–99.5) when using TAA]. In women who were DNA positive for one vaccine type, the vaccine was efficacious against the other vaccine type. The vaccine did not impact the outcome of HPV‐16/18 infections present at the time of vaccination. Vaccination was generally well tolerated regardless of the woman's HPV‐16/18 DNA or serological status at entry.
Biomarkers of oxidant load and type‐specific clearance of prevalent oncogenic human papillomavirus infection: Markers of immune response?
Authors: Siegel Erin M. , Patel Nitin , Lu Beibei , Lee Ji‐Hyun , Nyitray Alan G. , Craft Neal E. , Frenkel Krystyna , Villa Luisa L. , Franco Eduardo L. , Giuliano Anna R.
Published: August 2011

Human papillomavirus (HPV) infection is the cause of cervical cancer. Increased production of reactive oxygen species (ROS) maybe the common mechanism through which HPV‐cofactors (i.e., smoking and inflammation) influence duration of infections. Biomarkers of total oxidant load may serve as cumulative measures of ROS exposure due to these cofactors. Therefore, we conducted a study evaluating the association between biomarkers of oxidant load and duration of HPV infections, early HPV natural history events. Serum samples were obtained from 444 HPV‐positive women in the Ludwig‐McGill Cohort Study. Anti‐5‐hydroxymethyl‐2′‐deoxyuridine autoantibody (anti‐HMdU aAb) and malondialdehyde (MDA) were measured at baseline. Cox‐proportional hazard models were used to estimate the probability of clearing any HPV, oncogenic HPV, non‐oncogenic HPV and HPV‐16 infections. Women with elevated MDA were significantly more likely to clear prevalent oncogenic HPV infections compared to those with lower MDA levels (Adjusted Hazard Ratio (AHR) = 2.7; 95%CI = 1.4‐5.1). There did not appear to be an association between elevated MDA and clearance of incident oncogenic HPV infections. Similarly, women with elevated anti‐HMdU aAb levels had higher rates of prevalent oncogenic HPV infection clearance (Quartile 3:AHR = 2.2; 95%CI = 1.2‐4.4; Quartile 4:AHR = 2.4; 95%CI = 1.2‐4.9). Higher levels of oxidant load biomarkers were associated with increased clearance of prevalent HPV infections. However, oxidant load biomarkers measured before incident infections were not associated, suggesting that the elevation of MDA and anti‐HMdU aAb may reflect an ongoing effective immune response, such as increased innate immunity. More research focused on the immune responses to HPV and elevated markers of oxidant load is needed.
Promiscuous survivin peptide induces robust CD4+ T‐cell responses in the majority of vaccinated cancer patients
Authors: Widenmeyer Melanie , Griesemann Heinrich , Stevanović Stefan , Feyerabend Susan , Klein Reinhild , Attig Sebastian , Hennenlotter Jörg , Wernet Dorothee , Kuprash Dmitri V. , Sazykin Alexei Y. , Pascolo Steve , Stenzl Arnulf , Gouttefangeas Cécile , Rammensee Hans‐Georg
Published: August 2011

CD4+ T cells have been shown to be crucial for the induction and maintenance of cytotoxic T cell responses and to be also capable of mediating direct tumor rejection. Therefore, the anticancer therapeutic efficacy of peptide‐based vaccines may be improved by addition of HLA class II epitopes to stimulate T helper cells. Survivin is an apoptosis inhibiting protein frequently overexpressed in tumors. Here we describe the first immunological evaluation of a survivin‐derived CD4+ T cell epitope in a multipeptide immunotherapy trial for prostate carcinoma patients. The survivin peptide is promiscuously presented by several human HLA‐DRB1 molecules and, most importantly, is naturally processed by dendritic cells. In vaccinated patients, it was able to induce frequent, robust and multifunctional CD4+ T cell responses, as monitored by IFN‐γ ELISPOT and intracellular cytokine staining. Thus, this HLA‐DR restricted epitope is broadly immunogenic and should be valuable for stimulating T helper cells in patients suffering from a wide range of tumors.
IL‐13 regulates cancer invasion and metastasis through IL‐13Rα2 via ERK/AP‐1 pathway in mouse model of human ovarian cancer
Authors: Fujisawa Toshio , Joshi Bharat H. , Puri Raj K.
Published: August 2011

Previously, we have demonstrated that a variety of human cancers including the ovarian cancer express IL‐13Rα2, a high affinity receptor for IL‐13. Herein, we have examined if IL‐13 regulates invasion and metastasis of ovarian cancer through IL‐13Rα2 in vitro and in vivo in animal models of human ovarian cancer. We tested cell invasion and protease activity in IL‐13Rα2‐overexpressing and IL‐13Rα2‐negative ovarian tumor cell lines. IL‐13 treatment significantly augmented both cell invasion and enzyme activities in only IL‐13Rα2‐positive cells but not in IL‐13Rα2‐negative cells in vitro. Mechanistically, IL‐13 enhanced ERK1/2, AP‐1 and MMP activities only in IL‐13Rα2‐positive cells but not in IL‐13Rα2‐negative cells. In contrast, other signaling pathways such as IRS1/2, PI3K and AKT do not seem to be involved in IL‐13 induced signaling in ovarian cancer cell lines. Highly specific inhibitors for MMP and AP‐1 efficiently inhibited both invasion and protease activities without impacting the basal level invasion and protease activities in vitro. In orthotopic animal model of human ovarian cancer, IL‐13Rα2‐positive tumors metastasized to lymph nodes and peritoneum earlier than IL‐13Rα2‐negative tumors. Interestingly, the IL‐13Rα2‐positive tumor bearing mice died earlier than mice with IL‐13Rα2‐negative tumor. Intraperitoneal injection of IL‐13 further shortened survival of IL‐13Rα2‐positive tumor bearing mice compared to IL‐13Rα2‐negative tumor mice. IL‐13Rα2‐positive tumors and lymph node metastasis expressed higher levels of MMPs and higher ERK1/2 activation compared to IL‐13Rα2‐negative tumors. Taken together, IL‐13Rα2 is involved in cancer metastasis through activation of ERK/AP‐1 and that targeting IL‐13Rα2 might not only directly kill primary tumors but also prevent cancer metastasis.