bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploring the Polyamine Regulatory Site of the NMDA Receptor: a Parallel Synthesis Approach
Authors: Berger Michael L. , Pöhler Thomas , Schadt Oliver , Stanger Maximilian , Rebernik Patrick , Scholze Petra , Noe Christian R. 
Published: December 2012

AbstractThe elongated structures of polyamine inverse agonists such as 1,12‐diaminododecane (N12N) and 5‐(4‐aminobutyl)‐2‐thiopheneoctanamine (N4T8N) lend themselves to a combinatorial chemistry approach to explore a potential polyamine pharmacophore at the NMDA receptor. Herein we describe more than 100 new analogues of N4T8N obtained by breaking up the long octanamine arm into a dipeptide chain of equivalent length. Solid‐phase parallel synthesis based on cross‐linked polystyrene and a Wang anchor allowed the low‐scale preparation of four small libraries based on the combination of two amino acid residues (out of Gly, Leu, Phe, Lys, phenylglycine, Tyr, Trp, His, and Arg). The obtained compounds were tested as modulators of [3H]MK‐801 binding to rat brain membranes and of NMDA‐induced currents in cultured rat hippocampal neurons. Compounds with two aromatic residues acted as binding inhibitors (inverse agonists). Compounds with two Lys residues acted as binding stimulators (agonists) and had stimulatory and inhibitory effects on NMDA‐induced currents, depending on the holding potential. High sensitivity of binding inhibition to spermine was conferred by a Tyr residue, whereas a His residue favored high potency at acidic pH.
Visible and near infrared fluorescence spectral flow cytometry
Authors: Nolan John P. , Condello Danilo , Duggan Erika , Naivar Mark , Novo David 
Published: December 2012

AbstractThere is a long standing interest in measuring complete emission spectra from individual cells in flow cytometry. We have developed flow cytometry instruments and analysis approaches to enable this to be done routinely and robustly. Our spectral flow cytometers use a holographic grating to disperse light from single cells onto a CCD for high speed, wavelength‐resolved detection. Customized software allows the single cell spectral data to be displayed and analyzed to produce new spectra‐derived parameters. We show that familiar reference and calibration beads can be employed to quantitatively assess instrument performance. We use microspheres stained with six different quantum dots to compare a virtual bandpass filter approach with classic least squares (CLS) spectral unmixing, and then use antibody capture beads and CLS unmixing to demonstrate immunophenotyping of peripheral blood mononuclear cells using spectral flow cytometry. Finally, we characterize and evaluate several near infrared (NIR) emitting fluorophores for use in spectral flow cytometry. Spectral flow cytometry offers a number of attractive features for single cell analysis, including a simplified optical path, high spectral resolution, and streamlined approaches to quantitative multiparameter measurements. The availability of robust instrumentation, software, and analysis approaches will facilitate the development of spectral flow cytometry applications. © 2012 International Society for Advancement of Cytometry
Genetic diversity of North American captive‐born gorillas (Gorilla gorilla gorilla)
Authors: Simons Noah D. , Wagner Ronald S. , Lorenz Joseph G. 
Published: December 2012

AbstractWestern lowland gorillas (Gorilla gorilla gorilla) are designated as critically endangered and wild populations are dramatically declining as a result of habitat destruction, fragmentation, diseases (e.g., Ebola) and the illegal bushmeat trade. As wild populations continue to decline, the genetic management of the North American captive western lowland gorilla population will be an important component of the long‐term conservation of the species. We genotyped 26 individuals from the North American captive gorilla collection at 11 autosomal microsatellite loci in order to compare levels of genetic diversity to wild populations, investigate genetic signatures of a population bottleneck and identify the genetic structure of the captive‐born population. Captive gorillas had significantly higher levels of allelic diversity (t7 = 4.49, P = 0.002) and heterozygosity (t7 = 4.15, P = 0.004) than comparative wild populations, yet the population has lost significant allelic diversity while in captivity when compared to founders (t7 = 2.44, P = 0.04). Analyses suggested no genetic evidence for a population bottleneck of the captive population. Genetic structure results supported the management of North American captive gorillas as a single population. Our results highlight the utility of genetic management approaches for endangered nonhuman primate species.
Four Members of the Sandwich‐Type Polytungstophosphate Family Based on Pentalacunary [HPW7O28]8– Building Blocks
Authors: Zhang Dongdi , Zhang Yanhui , Zhao Juan , Ma Pengtao , Wang Jingping , Niu Jingyang 
Published: December 2012

AbstractFour dimeric mononuclear sandwich‐type tungstophosphate clusters of Na12H[FeIII(HPW7O28)2]·44H2O (1) and Na14[M(HPW7O28)2]·44H2O {M = CoII (2), CdII (3), MnII (4)} were successfully synthesized by reaction of Na2WO4·2H2O, H3PO4, and CH3COOH with FeCl3·6H2O, Co(CH3COO)2·4H2O, CdSO4·8H2O, and Mn(CH3COO)2·4H2O, respectively. Single‐crystal X‐ray diffraction analysis revealed that 1–4 are essentially isomorphous and crystallize in the triclinic space group P$\bar {1}$. Complexes 1–4 consist of two [HPW7O28]8– units incorporating a single FeIII, CoII, CdII, and MnII ion, respectively. Furthermore, the electrocatalytic behaviors of 1–4 in the reduction of nitrite were investigated.
Production of nitrogen‐based platform chemical: cyanophycin biosynthesis using recombinant Escherichia coli and renewable media substitutes
Authors: Zhang Yixing , Kumar Amit , Vadlani Praveen V. , Narayanan Sanjeev 
Published: December 2012

AbstractBackgroundCyanophycin (CGP) is a sustainable polymer that can be converted to a derivative with reduced arginine content, or to completely biodegradable poly‐aspartic acid, which can substitute for non‐biodegradable polyacrylates. In nature, it is produced by most cyanobacteria; however, these microbes are not suitable for large‐scale production due to slow growth and low polymer content.ResultsCyanophycin synthetase gene (cphA) from Anabaena variabilis ATCC 29413 was PCR amplified and cloned into Escherichia coli. Different renewable media components, such as soybean meal, potato wastes and corn‐derived zein hydrolysate, were evaluated for their feasibility for CGP production at shake flask level. The optimized conditions were then tested in a 7 L bioreactor; a maximum cell weight of 10.2 g L‐1 was obtained. CGP comprised 23 g g‐1 of cell dry matter (CDM) with molecular weight between 21.5 and 31 kDa and was composed of aspartic acid, arginine and lysine in the ratio of 1.05:1:0.2 (mass basis).ConclusionThe efficient use of renewable biomass for cyanophycin production could achieve competitive price, and in return, promote the use of this platform chemical to produce innovative polymers and materials.© 2012 Society of Chemical Industry
Evaluation of Ba‐promoted Mo carbide catalyst for Fischer–Tropsch synthesis
Authors: Vo Dai‐Viet N. , Arcotumapathy Viswanathan , Abdullah Bawadi , Adesina Adesoji A. 
Published: December 2012

AbstractBackgroundTraditional FT catalysts such as Co and Fe still suffer from carbon‐induced deactivation even with alkali promotion. The objective of this study was to examine the effect of Ba addition to carbon‐tolerant Mo carbide since it has Pt‐like characteristics and is cheaper than noble metals as an FT catalyst.ResultsThe presence of Ba increased the Mo carbide production rate and reduced the activation energy for its formation. The promoted catalyst exhibited higher specific basic site strength and CO2 uptake for strong basic site than that of the undoped catalyst. Both catalysts exhibited optimal reaction rate at a H2 mole fraction of 0.75 while CO consumption rate, total olefin‐to‐paraffin ratio, methane suppression as well as C5+ selectivity were improved with Ba addition. The non‐standard Anderson–Schulz–Flory (ASF) product distribution observed for the Ba‐doped catalyst may be due to the appearance of an additional polymerization site on the catalyst surface located in the BaMoO4 phase. Chain growth factor was enhanced by up to 93% from 0.43 to 0.83 with the Ba‐doped catalyst.ConclusionsBa promoter increased chain growth probability by about 93%. The deviation of product distribution from standard ASF plots with 2 chain growth factors for the 3wt%Ba‐10%MoC1‐x/Al2O3 catalyst was probably due to the presence of different active sites for chain initiation. The result is unprecedented and represents excellent opportunity for industrial exploitation of a new and relatively cheap carbon‐resistant catalyst.© 2012 Society of Chemical Industry
Tetracycline degradation and mineralization by the coupling of an electro‐Fenton pretreatment and a biological process
Authors: Ferrag‐Siagh Fatiha , Fourcade Florence , Soutrel Isabelle , Aït‐Amar Hamid , Djelal Hayet , Amrane Abdeltif 
Published: December 2012

AbstractBACKGROUNDStudies on the degradation and mineralization of tetracycline by means of the electro‐Fenton process are lacking in the available literature. Its relevance as a pre‐treatment prior to a biological process for the removal of tetracycline was therefore examined.RESULTSDegradation followed pseudo‐first‐order kinetics and the optimal operating conditions were: 0.1 mmol L‐1 catalyst (Fe2+) concentration, 300 mA applied current intensity and 25 mg L‐1 tetracycline, leading to total degradation within only 5 min and a mineralization yield of 89 % after 6 h electrolysis. Biodegradability tests were realized with 100 mg L‐1 tetracycline; BOD5/COD ratio increased from 0.02 to 0.56 after 6 h electrolysis, showing the relevance of the electro‐Fenton pre‐treatment. However, to keep a significant residual organic content, 2 to 4 h electrolysis time may be more relevant, leading to BOD5/COD ratio and mineralization yields of 0.33–0.44 and 46–72%, respectively.CONCLUSIONActivated sludge cultures of pretreated and non‐pretreated tetracycline solutions were carried out for 3 weeks. The overall TOC removal increased from 28% for the non‐pretreated tetracycline to 68 and 86% after 2 and 4 h electrolysis, confirming the efficiency of the proposed combined process. © 2012 Society of Chemical Industry
Years‐identification mathematical model of paeonia lactiflora pall. based on the allometric‐scaling
Authors: Cheng Chunsong , Peng Daiyin , Huang Luqi , Ma Xiaohui 
Published: December 2012

AbstractThe fixed number years‐identification of Chinese material medicinal was a difficulty in the process of the traditional Chinese pharmacology, the phenomenon was found in our study of telomerase that the speed of the vascular cambium outside expanding growth fluctuated in a definite value. Based on it, we put forward a hypothesis that the radial length of the vascular cambium to expand (Δb)and the radius of cross section (Δr) are constant in every activity cycle if the external environment factors unchanged every year. Therefore, We defined that the proportion (k) of Δr and Δb is constant (Δr/Δb = k). Then, each of Δb and Δr fluctuating in a fixed value in every year, because of the different rainfall, temperature, and sunniness every year. The hypothesis was proved correct within the domain of definition range, through the extrapolation of mathematical method. Hence, the telomerase experimental results just become effective evidence on mechanism. The conclusion we obtained include the following three: the telomerase experimental show that the activity gradually decreased in the Paeonia overall taproot, while, the it does not seem significantly change in the parts of the cambium cells with increasing age; Microscopy studies and mathematical models exploration gave us an identification method which can determine the growth years of Chinese medicinal materials (Refers to a kind of herbs exclusive which contains taproot), and, for example, we can use the mathematical model y = 0.02x−0.5
$ \left(P = {0.08 \over {k^2}{n}\Delta {b}}-{0.0016 \over \Delta {b }^2{ n}^2{ k}^2}\right) $
to identify the years of the Paeonia lactiflora Pall; the power function of allometric‐scaling explored at microscopic cellular‐level firstly. Ginseng, for example, more definitive proved a mathematical relationship of the allometric scaling in the taproot of plants. Microsc. Res. Tech., 2013. © 2012 Wiley Periodicals, Inc.
10Be ages of late Pleistocene deglaciation and Neoglaciation in the north‐central Brooks Range, Arctic Alaska
Authors: Badding Michael E. , Briner Jason P. , Kaufman Darrell S. 
Published: December 2012

AbstractWe present a chronology of late Pleistocene deglaciation and Neoglaciation for two valleys in the north‐central Brooks Range, Alaska, using cosmogenic 10Be exposure dating. The two valleys show evidence of ice retreat from the northern range front before ∼16–15 ka, and into individual cirques by ∼14 ka. There is no evidence for a standstill or re‐advance during the Lateglacial period, indicating that a glacier advance during the Younger Dryas, if any, was less extensive than during the Neoglaciation. The maximum glacier expansion during the Neoglacial is delimited by moraines in two cirques separated by about 200 km and dated to 4.6 ± 0.5 and 2.7 ± 0.2 cal ka BP. Both moraine ages agree with previously published lichen‐inferred ages, and confirm that glaciers in the Brooks Range experienced multiple advances of similar magnitude throughout the late Holocene. The similar extent of glaciers during the middle Holocene and the Little Ice Age may imply that the effect of decreasing summer insolation was surpassed by increasing aridity to limit glacier growth as Neoglaciation progressed. Copyright © 2012 John Wiley & Sons, Ltd.
Ultrasonic Breaking of Fibers and Microparticles into Mesoporous Particles with High Loading of Magnetic Nanoparticles
Authors: Hyun Dong Choon , Jo Eunmin , Park Choo Jin , Lim Min‐Cheol , Paik Hyun‐Jong , Cho Eun Chul , Kim Young‐Rok , Jeong Unyong 
Published: December 2012

AbstractHerein, a facile method for the large‐scale production of mesoporous polymer/nanoparticle (NP) composites, with high‐loading‐efficiency of nanoparticles, is presented. The composite fibers and microparticles composed of polystyrene (PS), poly(ethylene oxide) (PEO), and Fe2O3 NPs were obtained by electrojetting. After selectively dissolving the PEO phase, simple ultrasonication broke the porous fibers and the microparticles into numerous small mesoporous composite particles. For the breaking of the fibers and microparticles, the use of low‐molecular‐weight polymer was critical. As an example demonstration, we produced mesoporous PS particles with a large amount of magnetic NPs. magnified image
Photo‐Degradable, Protein–Polyelectrolyte Complex‐Coated, Mesoporous Silica Nanoparticles for Controlled Co‐Release of Protein and Model Drugs
Authors: Wan Xuejuan , Liu Tao , Hu Jinming , Liu Shiyong 
Published: December 2012

AbstractThe fabrication of photo‐degradable, protein–polyelectrolyte complex (PPC)‐coated, mesoporous silica nanoparticles (MSNs) and their controlled co‐release of protein and model drugs is reported. Random copolymers composed of oligo(ethylene glycol) monomethyl ether methacrylate (OEGMA), and a photolabile o‐nitrobenzyl‐containing monomer, 5‐(2′‐(dimethylamino)ethoxy)‐2‐nitrobenzyl methacrylate (DENBMA), are first anchored onto the MSNs and then quaternary aminated, to obtain positively charged P(OEGMA‐co‐TENBMA) which exhibits photo‐induced charge conversion characteristics. PPCs consisting of P(OEGMA‐co‐TENBMA) and the protein bovine serum albumin (BSA) are utilized as capping agents for the nanopores of the MSNs. Upon UV irradiation, charge conversion of P(OEGMA‐co‐TENBMA) can lead to the disruption of PPCs on MSNs and co‐release of BSA and rhodamine B by electrostatic repulsion.
Effect of surface modification of aluminum nitride on electrical and thermal characterizations of thermosetting polymeric nanocomposites
Authors: Choudhury Mousam , Mohanty Smita , Nayak Sanjay K. 
Published: December 2012

AbstractThermally conductive composites and nanocomposites composed of epoxy resin as base matrix and aluminum nitride (AlN) as micro and nanofiller have been studied at variable temperatures and loading of AlN. To improve the dispersion of the filler within the polymer matrix, AlN was surface modified with silane‐coupling agent. Thermogravimetric analysis confirmed the interfacial bonding of epoxy‐ and silane‐modified AlN. The dielectric properties of epoxy/AlN composites and nanocomposites have been studied at variable percentage of filler. Test result indicated an increase of thermal conductivity of the composites at 20 wt% of AlN. Also, silane‐treated composites exhibited improved electrical conductivity properties, whereas the electrical insulation property decreased in terms of dielectric strength and resistivity. POLYM. COMPOS., 2013. © 2012 Society of Plastics Engineers
First principles electronic structure of coincidence site epitaxial Ag/Si(111) interface
Authors: Abdul Wasey A. H. M. , Batabyal R. , Mahato J. C. , Dev B. N. , Kawazoe Y. , Das G. P. 
Published: December 2012

AbstractAg/Si(111) heterojunction having ∼25% lattice mismatch can be formed by placing four surface unit cells of Ag(111) on three surface unit cells of Si(111), thereby reducing the effective strain in the Ag film to ∼0.3% in this coincidence site epitaxial growth. We have carried out first‐principles investigation of such Ag/Si(111) interface to establish the interplay between the structural and electronic properties. While the Ag overlayer affects the reconstruction of the Si(111) surface, we find that the geometrical relaxation of the Ag atoms is influenced by the sub‐surface Si‐layer and the concomitant lattice mismatch. The electronic density of states show some oscillations near the Fermi energy, which have been compared with the scanning tunnelling spectroscopic (STS) experimental data. The signature of metal‐induced gap states (MIGS) for this metal–semiconductor heterojunction has been established from the evolution of localized gap states in the layer projected density of states. Our DFT estimated work function values for Ag(100), (110) and (111) have an excellent agreement with the available experimental results. Also, the p‐type Schottky barrier height (SBH) of this rectifying Ag/Si contact has been calculated from the Kohn–Sham estimates of EF − Ev modified by the interface induced dipole.
Magnetotransport and induced superconductivity in Bi based three‐dimensional topological insulators
Authors: Veldhorst M. , Snelder M. , Hoek M. , Molenaar C. G. , Leusink D. P. , Golubov A. A. , Hilgenkamp H. , Brinkman A. 
Published: December 2012

Abstractmagnified imageThe surface of a three‐dimensional (3D) topological insulator is conducting and the topologically nontrivial nature of the surface states is observed in experiments. It is the aim of this paper to review and analyze experimental observations with respect to the magnetotransport in Bi‐based 3D topological insulators, as well as the superconducting transport properties of hybrid structures consisting of superconductors and these topological insulators. The helical spin‐momentum coupling of the surface state electrons becomes visible in quantum corrections to the conductivity and magnetoresistance oscil‐lations. An analysis will be provided of the reported magnetoresistance, also in the presence of bulk conductivity shunts. Special attention is given to the large and linear magnetoresistance. Superconductivity can be induced in topological superconductors by means of the proximity effect. The induced supercurrents, Josephson effects and current–phase relations will be reviewed. These materials hold great potential in the field of spintronics and the route towards Majorana devices. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A quad‐band W‐CDMA transceiver IC–direct conversion architecture with fractional frequency divider
Authors: Kamizuma Hiroshi , Akamine Yukinori , Yamawaki Taizo , Hikasa Kazuhiko 
Published: December 2012

AbstractA quad‐band (0.8, 1.7, 2, and 1.4 GHz) wideband code division multiple access (W‐CDMA) transceiver, which uses a divide‐by‐2.5 frequency divider in local parts of a direct‐conversion architecture, has been developed. Using the fractional‐2.5 frequency divider reduces the fractional bandwidth of the voltage‐controlled oscillator and avoids injection locking of the local RF synthesizer perfectly. This transceiver achieved 3% error‐vector magnitude and—46 dB ACLR, which satisfy the margin given in standard specifications. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Optimal frequency tracking method for phase‐shift PWM inverter
Authors: Kifune Hiroyasu , Hatanaka Yoshihiro 
Published: December 2012

AbstractThis paper proposes a new resonant frequency tracking control method for full‐bridge‐type high‐frequency inverters. Whereas the ordinary phase‐locked loop (PLL) based frequency control method uses a current sensor and a voltage sensor, the proposed technique can achieve the same purpose with a single current sensor. In high‐frequency power supply systems using a PLL, it is impossible to perform power control with an inverter. Therefore, an active converter must be used for power control, and the system grows larger. On the other hand, high‐frequency inverters using the proposed control system simultaneously enable power control and achieve the same resonant frequency tracking as a PLL, and thus high‐frequency power supply systems become extremely simple. This paper explains in detail the principle underlying the control method, and presents an example of a circuit to realize it. The theory is backed up by using a prototype high‐frequency power supply system which actually employs the proposed control system, thereby demonstrating its practical utility in industry. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Improving routing in networks of Unmanned Aerial Vehicles: Reactive‐Greedy‐Reactive
Authors: Li Yi , Shirani Rostam , St‐Hilaire Marc , Kunz Thomas 
Published: December 2012

ABSTRACTBecause of their specific characteristics, Unmanned Aeronautical Ad‐hoc Networks (UAANETs) can be classified as a special kind of mobile ad hoc networks. Because of the high mobility of Unmanned Aerial Vehicles, designing a good routing protocol for UAANETs is challenging. Here, we present a new protocol called Reactive‐Greedy‐Reactive (RGR) as a promising routing protocol in high mobility and density‐variable scenarios. RGR combines features of reactive MANET routing protocols such as Ad‐hoc On‐demand Distance Vector with geographic routing protocols, exploiting the unique characteristics of UAANETs. In addition to combining reactive and geographic routing, the protocol has a number of features to further improve the overall performance. We present the rationale and design of the protocol, discuss the specific performance improvements in detail and provide extensive simulation results that demonstrate that RGR outperforms purely reactive or geographic routing protocols. The results also demonstrate the impact of the various protocol modifications. Copyright © 2012 John Wiley & Sons, Ltd.