bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption and drug release based on β‐cyclodextrin‐grafted hydroxyapatite composite
Authors: Tang Weili , Zhao Jingchan , Sha Bijing , Liu Hong
Published: May 2012

In this study, β‐cyclodextrin (β‐CD) was covalently grafted on hydroxyapatite (HA) using a coupling agent to improve the drug loading capacity and prolong the drug release. The binding of β‐CD on the HA surface was confirmed by Fourier transformation infrared spectroscopy, thermal gravimetric analysis, and X‐ray powder diffraction. The adsorption capacity of ofloxacin on β‐CD‐grafted hydroxyapatite (β‐CD‐g‐HA) composite was found to be 30 mg g−1 at 37°C and 24 h. The adsorption process is spontaneous, given the negative values of free energy change. Compared with the release of ofloxacin loaded on HA, the release of ofloxacin loaded on β‐CD‐g‐HA was slowed down 28% and 21% in pH 2.0 and pH 7.4 buffer media at 2 h, respectively. Biocompatibility of β‐CD‐g‐HA was assessed by MTT assay, and the result showed that it had no cytotoxicity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Kinetics of glycolysis of poly(ethylene terephthalate) under microwave irradiation
Authors: Chen Feifei , Wang Guanghui , Shi Chuan , Zhang Yichen , Zhang Long , Li Wei , Yang Feng
Published: May 2012

The glycolysis of poly(ethylene terephthalate) (PET) was carried out using excess ethylene glycol (EG) in the presence of zinc acetate as catalysts under microwave irradiation. The effects of particle size, microwave power, the weight ratio of EG to PET, the weight ratio of catalyst to PET, reaction temperature and stirring speed on the yield of bis(hydroxyethyl terephthalate)(BHET) were investigated. The experimental results indicated that the glycolysis rate was significantly influenced by stirring speed and initial particle size. The optimal parameters of glycolysis reactions were the weight ratio of catalyst to PET of 1%, the weight ratio of EG to PET of 5, 500 W and 196°C, the yield of BHET reached to 78% at only 35 min. The glycolysis products were analyzed and identified by FTIR, differential scanning calorimetry, and elemental analysis. The kinetics of glycolysis of PET under microwave irradiation could be interpreted by the shrinking core model of the film diffusion control. The apparent activation energy was evaluated using the Arrhenius equation and it was found to be 36.5 KJ/mol, which was lower compared to the same process using conventional heating. The experimental results also showed that the reaction time was significantly decreased under microwave irradiation as compared with it by conventional heating. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Electric‐field‐induced aggregation of polymeric micelles to construct secondary assembly films
Authors: Liu Ren , Luo Jing , Tao Youhua , Zhu Ye , Chen Mingqing , Liu Xiaoya
Published: May 2012

A new amphiphilic quaternary random ionomer (PIDHES) was used to construct self‐assembly films. PIDHES was prepared by a selective ionization of quaternary random copolymer, poly(N,N‐domethyl amimethyl methartylate‐co‐2‐hydroxypropyl methacrylate‐co‐2‐ethylhexyl acrylate‐co‐styrene) precursor, which was synthesized by free radical copolymerization of commercial hydrophilic monomers N, N‐domethyl amimethyl methartylate and 2‐hydroxypropyl methacrylate and hydrophobic monomers 2‐ethylhexyl acrylate and styrene PIDHES could self‐assemble into polymer micelles in water, which underwent orientated deposition in the electric field and ultimately produced secondary assembly films. Scanning electron microscopy studies showed that the resultant PIDHES secondary assembly film was smooth and compact. Moreover, it was found that PIDHES micelles concentration and electric‐field‐induced time had a strong influence on the morphologies of the resultant secondary assembly film. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis of high‐solid content sulfonate‐type polyurethane dispersion by pellet process
Authors: He Lina , Sun Dongcheng
Published: May 2012

A novel method to prepare polyurethane dispersions (PUDs) is introduced in this article. Water dispersible polyurethane ionomer pellets were synthesized without solvent; these pellets were then dissolved in acetone and dispersed in water. Then PUDs were obtained after acetone was distilled off. Polyurethane ionomers were synthesized from polyether diol containing sulfonate as hydrophilic monomer and poly(1,4‐butylene adipate glycol) with an average molecular weight of 3000 as soft segments, isophorone diisocyanate and 1,4‐butanediol as hard segments, and dibutyltin dilaurate as catalyst. The properties of PUDs were measured by Laser particle size analyzer, Brookfield viscosity, and TEM analysis. High‐solid content and low viscosity PUDs were obtained. Meanwhile, PUDs exhibited excellent stability and polydispersity according to the above analysis. Tensile tests and dynamic mechanical analysis showed good mechanical and thermodynamic properties of PUD films. Some typical characteristics of crystalline polymers were revealed in the tensile stress–strain curves of PUD films. Peel strength test (PVC/PVC) yielded a maximum initial peel strength value of 6 N/mm and T‐peel strength value of 10 N/mm. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis and Spectral Characterization of New Bis(2‐(pyrimidin‐2‐yl)ethoxy)alkanes and Their Pharmacological Activity
Authors: Rani Vangavaragu Jhansi , Aminedi Raghavendra , Polireddy Kishore , Jagadeeswarareddy Kanala
Published: May 2012

The pyrimidine nucleus is an important component of nucleic acids (DNA and RNA) and vitamins (B2 and folic acid). It is evident from the literature that pyrimidine derivatives possess a wide spectrum of biological activities such as antioxidant, anticancer, antibacterial, and anti‐inflammatory activities. On the basis of diverse biological activities, we attempted to synthesize a series of novel bis(2‐(pyrimidin‐2‐yl)ethoxy)alkanes 5a–j in four steps with good yields. 2‐Chloropyrimidine (1) was reacted with diethyl malonate in the presence of sodium hydride in dry dimethyl formamide to yield the intermediate diethyl 2‐(pyrimidin‐2‐yl)malonate (2), which on further reaction with sodium chloride and dimethyl sulfoxide yielded ethyl 2‐(pyrimidin‐2‐yl)ethanoate (3). Reduction with sodium borohydride (NaBH4) resulted in the formation of 2‐(pyrimidin‐2‐yl)ethanol (4). This was further reacted with various dibromoalkanes to obtain the title compounds 5a–j. In this current study, we evaluated the antioxidant properties of the title compounds using four in vitro test systems: the 2,2‐diphenyl‐2‐picrylhydrazyl radical‐, superoxide radical‐, and hydroxyl radical‐scavenging assays, and the anti‐lipid peroxidation activity test. The title compounds showed promising antioxidant activity when compared to butylated hydroxytoluene. The potency of their antioxidant activity was mainly influenced by the alkyl fragment attached to 2‐(pyrimidin‐2‐yl)ethanol. The ethyl and butyl fragments linked to oxygen led to increased antioxidant activity of the title compounds (i.e., 5b and 5d) in all our in vitro assays.
Synthesis and Bioevaluation of Diphyllin Glycosides as Novel Anticancer Agents
Authors: Zhao Yu , Ni Chunyan , Zhang Yuting , Zhu Li
Published: May 2012

A series of diphyllin glycosides were synthesized from diphyllin by phase transfer catalysis glycosylation, deprotection, and etherification, and the structures were established by 1H NMR, 13C NMR, and HRMS. These glycosides were evaluated for their in vitro cytotoxicity against HCT‐116, A549, and A549T cancer cell lines by MTT assay, and most of them were cytotoxic at submicromolar concentrations. They were also effective against the paclitaxel‐resistant cell line A549T. The kDNA decatenation assay indicated that most of these compounds inhibited topoisomerase IIα‐mediated kDNA decatenation. In addition, the in vitro tubulin polymerization study showed that compounds 5 and 6 had antimicrotubule activity with a paclitaxel‐like mode of action. Taken together, these results suggest that these diphyllin glycosides act on both TopoII and tubulin.
Identification of leukemia stem cells in acute myeloid leukemia and their clinical relevance
Authors: Hoang Van Thanh , Zepeda‐Moreno Abraham , Ho Anthony D.
Published: May 2012

Acute myeloid leukemia (AML) is considered to be a disease of stem cells. A rare defective stem cell population is purported to drive tumor growth. Similarly to their normal counterparts, leukemic stem cells (LSC) divide extreme slowly. This may explain the ineffectiveness of conventional chemotherapy in combatting this disease. Novel treatment strategies aimed at disrupting the binding of LSC to stem cell niches within the bone marrow might render the LSC vulnerable to chemotherapy and thus improving treatment outcome. This review focuses on the detection of LSC, our current knowledge about their cellular and molecular biology, and LSC interaction with the niche. Finally, we discuss the clinical relevance of LSC and prospective targeted treatment strategies for patients with AML.
Programmable genetic switches to control transcriptional machinery of pluripotency
Authors: Pandian Ganesh N. , Sugiyama Hiroshi
Published: May 2012

Transcriptional activators play a central role in the regulation of gene expression and have the ability to manipulate the specification of cell fate. Pluripotency is a transient state where a cell has the potential to develop into more than one type of mature cell. The induction of pluripotency in differentiated cells requires extensive chromatin reorganization regulated by core transcriptional machinery. Several small molecules have been shown to enhance the efficiency of somatic cell reprogramming into pluripotent stem cells. However, entirely chemical‐based reprogramming remains elusive. Recently, we reported that selective DNA‐binding hairpin pyrrole‐imidazole polyamides conjugated with histone deacetylase inhibitor could mimic natural transcription factors and epigenetically activate certain pluripotency‐associated genes. Here, we review the need to develop selective chromatin‐modifying transcriptional activators for somatic genome reprogramming.
DNA Methylation Profiling Distinguishes Three Clusters of Breast Cancer Cell Lines
Authors: Zheng Siyuan , Zhao Zhongming
Published: May 2012

Methylation change plays an important role in many cellular systems, including cancer development. During recent years, genome‐wide or large‐scale methylation data has become available thanks to rapid advances in high‐throughput biotechnologies. So far, researchers have always used gene expression profiling to study disease subtypes and related therapies. In this study, we investigated methylation profiles in 30 breast cancer cell lines using methylation data generated by microarray technologies. Strong variation of the number of methylation peaks was found among these 30 cell lines; however, more peaks were found in the upstream regions than in downstream regions of genes. We further grouped the methylation profiles of these cell lines into three consensus clusters. Finally, we performed an integrative analysis of breast cancer cell lines using both methylation and gene‐expression profiling data. There was no significant correlation between methylation‐profiling subtypes and gene‐expression profiling subtypes, suggesting the complex nature of methylation in the regulation of gene expression. However, we found basal B cell lines appeared exclusively in two methylation clusters. Although these results are preliminary, this study suggests that methylation profiling might be promising in disease subtype classification and the development of therapeutic strategies.
A Core Process in Receptor Function, General Anesthesia, Sleep, and Aging
Authors: Kier Lemont B. , Slattum Patricia W.
Published: May 2012

The diffusion of ligands and proteins was proposed to be guided by chreodes in water organized by protein‐surface side chains with varying hydropathic states. These chreodes are proposed to be the target of volatile general anesthetic agents. The similarity between this effect and sleep deprivation leads to a proposal of an external agent responsible for sleep. This agent is elemental nitrogen. An extension of this effect is the concept that elemental nitrogen is a core factor in aging.
A New Era of the Vaginal Microbiome: Advances Using Next‐Generation Sequencing
Authors: Fettweis Jennifer M. , Serrano Myrna G. , Girerd Philippe H. , Jefferson Kimberly K. , Buck Gregory A.
Published: May 2012

Until recently, bacterial species that inhabit the human vagina have been primarily studied using organism‐centric approaches. Understanding how these bacterial species interact with each other and the host vaginal epithelium is essential for a more complete understanding of vaginal health. Molecular approaches have already led to the identification of uncultivated bacterial taxa associated with bacterial vaginosis. Here, we review recent studies of the vaginal microbiome and discuss how culture‐independent approaches, such as applications of next‐generation sequencing, are advancing the field and shifting our understanding of how vaginal health is defined. This work may lead to improved diagnostic tools and treatments for women who suffer from, or are at risk for, vaginal imbalances, pregnancy complications, and sexually acquired infections. These approaches may also transform our understanding of how host genetic factors, physiological conditions (e.g., menopause), and environmental exposures (e.g., smoking, antibiotic usage) influence the vaginal microbiome.
Identification of Metabolic Changes in Genetically Unstable Stem Cells by Using Model Analysis of Gene Expression
Authors: Vanee Niti , Roberts Seth B. , Riggs Marion Joe , Rao Raj R. , Fong Stephen S.
Published: May 2012

Stem‐cell research seeks to address many different questions related to fundamental stem‐cell function with the ultimate goal of being able to control and utilize stem cells for a broad range of therapeutic needs. While a large amount of work is focused on discovering and controlling differentiation mechanisms in stem cells, an equally interesting and important area of work is to understand the basics of stem‐cell propagation and self‐renewal. With high‐throughput genomics and transcriptomic information on hand, it is becoming possible to address some of the detailed mechanistic processes occurring in stem cells, though interpretation of these data is often difficult. In this work, stem cells with genetic abnormalities were compared to genetically normal stem cells using gene‐expression array data integrated with a large‐scale metabolic model to help interpret changes in metabolism resulting in the identification of several metabolic pathways that were different in the normal and abnormal cells.
Synthesis, Structure, Properties, and Application of a Carbazole‐Based Diaza[7]helicene in a Deep‐Blue‐Emitting OLED
Authors: Shi Longqiang , Liu Zhi , Dong Guifang , Duan Lian , Qiu Yong , Jia Jiong , Guo Wei , Zhao Dan , Cui Deliang , Tao Xutang
Published: May 2012

A carbazole‐based diaza[7]helicene, 2,12‐dihexyl‐2,12‐diaza[7]helicene (1), was synthesized by a photochemical synthesis and its use as a deep‐blue dopant emitter in an organic light‐emitting diode (OLED) was examined. Compound 1 exhibited good solubility and excellent thermal stability with a high decomposition temperature (Td=372.1 °C) and a high glass‐transition temperature (Tg, up to 203.0 °C). Single‐crystal structural analysis of the crystalline clathrate (1)2⋅cyclohexane along with a theoretical investigation revealed a non‐planar‐fused structure of compound 1, which prevented the close‐packing of molecules in the solid state and kept the molecule in a good amorphous state, which allowed the optimization of the properties of the OLED. A device with a structure of ITO/NPB (50 nm)/CBP:5 % 1 (30 nm)/BCP (20 nm)/Mg:Ag (100 nm)/Ag (50 nm) showed saturated blue light with Commission Internationale de L’Eclairage (CIE) coordinates of (0.15, 0.10); the maximum luminance efficiency and brightness were 0.22 cd A−1 (0.09 Lm W−1) and 2365 cd m−2, respectively. This new class of helicenes, based on carbazole frameworks, not only opens new possibilities for utilizing helicene derivatives in deep‐blue‐emitting OLEDs but may also have potential applications in many other fields, such as molecular recognition and organic nonlinear optical materials.
An efficient algorithm for mapping imaging data to 3D unstructured grids in computational biomechanics
Authors: Einstein Daniel R. , Kuprat Andrew P. , Jiao Xiangmin , Carson James P. , Einstein David M. , Jacob Richard E. , Corley Richard A.
Published: May 2012

Geometries for organ scale and multiscale simulations of organ function are now routinely derived from imaging data. However, medical images may also contain spatially heterogeneous information other than geometry that are relevant to such simulations either as initial conditions or in the form of model parameters. In this manuscript, we present an algorithm for the efficient and robust mapping of such data to imaging‐based unstructured polyhedral grids in parallel. We then illustrate the application of our mapping algorithm to three different mapping problems: (i) the mapping of MRI diffusion tensor data to an unstructured ventricular grid; (ii) the mapping of serial cyrosection histology data to an unstructured mouse brain grid; and (iii) the mapping of computed tomography‐derived volumetric strain data to an unstructured multiscale lung grid. Execution times and parallel performance are reported for each case. Copyright © 2012 John Wiley & Sons, Ltd.
General‐purpose computation on GPUs for high performance cloud computing
Authors: Expósito Roberto R. , Taboada Guillermo L. , Ramos Sabela , Touriño Juan , Doallo Ramón
Published: May 2012

Cloud computing is offering new approaches for High Performance Computing (HPC) as it provides dynamically scalable resources as a service over the Internet. In addition, General‐Purpose computation on Graphical Processing Units (GPGPU) has gained much attention from scientific computing in multiple domains, thus becoming an important programming model in HPC. Compute Unified Device Architecture (CUDA) has been established as a popular programming model for GPGPUs, removing the need for using the graphics APIs for computing applications. Open Computing Language (OpenCL) is an emerging alternative not only for GPGPU but also for any parallel architecture. GPU clusters, usually programmed with a hybrid parallel paradigm mixing Message Passing Interface (MPI) with CUDA/OpenCL, are currently gaining high popularity. Therefore, cloud providers are deploying clusters with multiple GPUs per node and high‐speed network interconnects in order to make them a feasible option for HPC as a Service (HPCaaS). This paper evaluates GPGPU for high performance cloud computing on a public cloud computing infrastructure, Amazon EC2 Cluster GPU Instances (CGI), equipped with NVIDIA Tesla GPUs and a 10 Gigabit Ethernet network. The analysis of the results, obtained using up to 64 GPUs and 256‐processor cores, has shown that GPGPU is a viable option for high performance cloud computing despite the significant impact that virtualized environments still have on network overhead, which still hampers the adoption of GPGPU communication‐intensive applications. Copyright © 2012 John Wiley & Sons, Ltd.
Exact capacity analysis of multi‐relay multiuser cooperative networks based on two‐step selection
Authors: Guo Weidong , Liu Ju , Liu Yuxi , Zheng Lina , Zhang Guowei
Published: May 2012

This paper advocates the capacity analysis of an amplify‐and‐forward cooperative communication system model in multi‐relay multiuser networks. A two‐step selection scheme is adopted, and both relay and user selection are based on the outdated channel state information. Exact expression of channel capacity for independent, but not necessarily identically distributed, Rayleigh fading channels is derived. Finally, simulations are carried out to verify the correctness of theoretical analysis and illustrate the effect of parameters on the performance. Results show that although the performance of our scheme is inferior to the optimal joint selection scheme, it is still a practical scheme because its complexity is much lower than that of the optimal scheme. Copyright © 2012 John Wiley & Sons, Ltd.
Circadian expression of the presynaptic active zone protein bruchpilot in the lamina of Drosophila melanogaster
Authors: Górska‐Andrzejak Jolanta , Makuch Renata , Stefan Joanna , Görlich Alicja , Semik Danuta , Pyza Elzbieta
Published: May 2012

In the fly's visual system, the morphology of cells and the number of synapses change during the day. In the present study we show that in the first optic neuropil (lamina) of Drosophila melanogaster, a presynaptic active zone protein Bruchpilot (BRP) exhibits a circadian rhythm in abundance. In day/night (or light/dark, LD) conditions the level of BRP increases two times, in the morning and in the evening. The same pattern of changes in the BRP level was detected in whole brain homogenates, thus indicating that the majority of synapses in the brain peaks twice during the day. However, these two peaks in BRP abundance, measured as the fluorescence intensity of immunolabeling, seem to be regulated differently. The peak in the morning is predominantly regulated by light and involves the transduction pathway in the retina photoreceptors. This peak is present neither in wild‐type Canton‐S flies in constant darkness (DD), nor in norpA7 phototransduction mutant in LD. However, it also depends on the clock gene per, because it is abolished in the per0 arrhythmic mutant. In turn, the peak of BRP in the evening is endogenously regulated by an input from the pacemaker located in the brain. This peak is present in Canton‐S flies in DD, as well as in the norpA7 mutant in LD, but is absent in per01, tim,01 and cry01 mutants in LD. In addition both peaks seem to depend on clock gene‐expressing photoreceptors and glial cells of the visual system. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2013
Sensitivity to Lexical Stress in Dyslexia: a Case of Cognitive not Perceptual Stress
Authors: Barry Johanna G. , Harbodt Silke , Cantiani Chiara , Sabisch Beate , Zobay Oliver
Published: May 2012

Sensitivity to lexical stress in adult German‐speaking students with reading difficulty was investigated using minimal pair prepositional verbs whose meaning and syntax depend on the location of the stressed syllable. Two tests of stress perception were used: (i) a stress location task, where listeners indicated the location of the perceptually most prominent syllable, and (ii) a stress pattern identification task, where listeners indicated if the stress pattern was appropriate for its semantic frame. The students with reading difficulties performed worse than the normally reading students on both tasks. Their poorer performance did not reflect the lack of a percept for lexical stress rather patterns of performance across the two tasks suggested that each loaded onto different underlying cognitive abilities. Deficits in these, rather than perceptual difficulties, explained observed group differences. Students with reading difficulties have a normal implicit knowledge of lexical stress usage but lack the necessary cognitive resources for developing an explicit metalinguistic awareness of it. Deficits in these skills not deficiencies in lexical stress perception are implicated in their reading difficulties. Copyright © 2012 John Wiley & Sons, Ltd.
A Cyano‐Bridged Vanadium–Niobium Bimetal Assembly Exhibiting a High Curie Temperature of 210 K (Eur. J. Inorg. Chem. 16/2012)
Authors: Imoto Kenta , Takemura Miho , Tokoro Hiroko , Ohkoshi Shin‐ichi
Published: May 2012

The front cover picture shows a schematic representation of the coordination network and the temperature dependence of magnetization of a cyano‐bridged V–Nb bimetal assembly, K0.59VII1.59VIII0.41[NbIV(CN)8]·(SO4)0.50·6.9H2O. This compound exhibits ferrimagnetism with a high Curie temperature (TC) of 210�K. This temperature is the highest TC value among those of octacyano‐bridged bimetal assemblies. The Short Communication by S. Ohkoshi et al. on p. 2649 ff. demonstrates that the increase in the superexchange pathways of VII–NC–NbIV contributes to the achievement of the high TC value.

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Thermolysis of 3,3,5,5‐Tetramethyl‐1,2,4‐trithiolane 1‐Oxide: First Matrix Isolation of the HOSS· Radical
Authors: Reisenauer Hans Peter , Mloston Grzegorz , Romanski Jaroslaw , Schreiner Peter R.
Published: May 2012

Flash vacuum pyrolysis of 3,3,5,5‐tetramethyl‐1,2,4‐trithiolane 1‐oxide performed at 700 °C yields the 1‐oxatrisulfan‐3‐yl radical (HOSS·) along with disulfur monoxide (S2O) and diisopropyl sulfide, which were isolated in argon matrices at 10 K. Upon irradiation with UV light, the 1‐oxatrisulfan‐3‐yl radical undergoes isomerization to the 1‐oxatrisulfan‐1‐yl radical (HSSO·). Both radicals were identified by comparison of their computed and experimental IR and UV/Vis spectra. In addition, density functional theory (DFT) computations offer a plausible explanation of the most likely reaction mechanism, suggesting that the initial step is a 1,3‐H shift with simultaneous ring opening. A 1‐oxatrisulfane derivative formed thereby undergoes fragmentations via a radical and a competitive concerted pathway leading to the observed final products. The same mechanism also governs the thermal fragmentation of di‐tert‐butyl disulfide S‐oxide. Its pyrolysis at 700 °C affords an analogous set of products, including the 1‐oxatrisulfan‐3‐yl radical (HOSS·) as the key intermediate.
C3v‐Symmetrical Tribenzotriquinacenes Bearing Six Benzylic Tentacle Groups at the Molecular Periphery
Authors: Mughal Ehsan Ullah , Kuck Dietmar
Published: May 2012

The synthesis and characterization of several C3v‐symmetrically extended tribenzotriquinacenes (TBTQs) bearing six benzylic C1‐tentacular functional groups at the arene periphery were reported. A new C3v‐symmetrical hexakis(chloromethyl)‐substituted TBTQ derivative was used as the key intermediate, and other derivatives were synthesized with high efficiency by either sixfold nucleophilic substitution reactions with phenols or sixfold Friedel–Crafts alkylation reactions with various arenes.
Inverse‐Opal Conducting Polymer Monoliths in Microfluidic Channels
Authors: Gorey Brian , Galineau Jeremy , White Blanaid , Smyth Malcolm R. , Morrin Aoife
Published: May 2012

Inverse opal monolithic flow‐through structures of conducting polymer (CP) were achieved in microfluidic channels for lab‐on‐a‐chip (LOC) applications. In order to achieve the uniformly porous monolith, polystyrene (PS) colloidal crystal (CC) templates were fabricated in microfluidic channels. Consequently, an inverse opal polyaniline (PANI) structure was achieved on‐chip, through a two‐step process involving the electrochemical growth of PANI and subsequent removal of the template. In this work the effect of CP electropolymerisation time on these structures is discussed. It was found that growth time is critical in achieving an ordered structure with well‐defined flow‐through pores. This is significant as these optimised porous structures will allow for maximising the surface area of the monolith and will also result in well‐defined flow profiles through the microchannel.
Determination of Sb(V) Using Differential Pulse Anodic Stripping Voltammetry at an Unmodified Edge Plane Pyrolytic Graphite Electrode
Authors: Lu Min , Rees Neil V. , Compton Richard G.
Published: May 2012

Antimony(V) determination at an unmodified edge plane pyrolytic graphite (EPPG) electrode using anodic stripping voltammetry (ASV) by depositing beyond the hydrogen wave is shown in this paper. By depositing beyond the hydrogen wave, we report a sensitive method to determine pentavalent antimony at a carbon electrode in 0.25 M HCl. Using differential pulse anodic stripping voltammetry (DPASV), a bare EPPG electrode gave a detection limit of 5.8±0.02 nM without the need for surface modification. This level is greatly within the EU limit for drinking water of 40 nM.
DIAPH3 governs the cellular transition to the amoeboid tumour phenotype
Authors: Hager Martin H. , Morley Samantha , Bielenberg Diane R. , Gao Sizhen , Morello Matteo , Holcomb Ilona N. , Liu Wennuan , Mouneimne Ghassan , Demichelis Francesca , Kim Jayoung , Solomon Keith R. , Adam Rosalyn M. , Isaacs William B. , Higgs Henry N. , Vessella Robert L. , Di Vizio Dolores , Freeman Michael R.
Published: May 2012

Therapies for most malignancies are generally ineffective once metastasis occurs. While tumour cells migrate through tissues using diverse strategies, the signalling networks controlling such behaviours in human tumours are poorly understood. Here we define a role for the Diaphanous‐related formin‐3 (DIAPH3) as a non‐canonical regulator of metastasis that restrains conversion to amoeboid cell behaviour in multiple cancer types. The DIAPH3 locus is close to RB1, within a narrow consensus region of deletion on chromosome 13q in prostate, breast and hepatocellular carcinomas. DIAPH3 silencing in human carcinoma cells destabilized microtubules and induced defective endocytic trafficking, endosomal accumulation of EGFR, and hyperactivation of EGFR/MEK/ERK signalling. Silencing also evoked amoeboid properties, increased invasion and promoted metastasis in mice. In human tumours, DIAPH3 down‐regulation was associated with aggressive or metastatic disease. DIAPH3‐silenced cells were sensitive to MEK inhibition, but showed reduced sensitivity to EGFR inhibition. These findings have implications for understanding mechanisms of metastasis, and suggest that identifying patients with chromosomal deletions at DIAPH3 may have prognostic value.
On utility‐optimised router‐level bandwidth allocation
Authors: Tan Liansheng , Yang Peng , Zhang Wei , Ge Fei
Published: May 2012

Kelly's network utility maximisation (NUM) problems and solutions are aimed to maximise the aggregate utility subject to link capacity constraints. They are formulated and solved by using the individual flow rate vector. Because of the architecture of the current networks such as the Internet, the individual flow rates are generally not measurable directly at the routers for the network service provider. However, the aggregate flow rates are more convenient to obtain and to adjust. In this paper, we still study the NUM problems for communication networks but from a router‐level bandwidth allocation standpoint. With the use of the generalised matrix inverse, we propose a general model of utility‐optimised router‐level bandwidth allocation and its solution, where the objective function and the constraints are formulated in terms of the aggregate flow rate vector rather than from the individual flow rate vector as in the usual NUM problem. We find that the new proposed models are equivalent to Kelly's NUM model in the sense that they lead to the same optimum and their solutions satisfy the given routing scheme. We also discuss the special cases where the routing matrix is of full row rank and where there is one single‐hop flow in every link in the network. We suggest a direct application to Internet Protocol‐based virtual private network of the latter case. We present the mathematical models and solution procedures that lead to the utility‐optimised aggregate flow rate vector and further illustrate them by numerical examples. We believe our approach is promising for deployment in communication networks. Copyright © 2012 John Wiley & Sons, Ltd.
Electricity and natural gas dance: It takes more than two to contango
Authors: Bodell Tanya
Published: May 2012

Participants in the US energy industry have been watching the fall in natural gas prices with seemingly shocked surprise.
Natural gas and electric distribution: Prior preparation, good communication key to recovering costs after storms
Authors: Stewart Calvin E. , Deric Miki
Published: May 2012

Every utility executive's worst fear is the type of punishing wind, snow, or ice storm that wreaks havoc on power systems, results in significant and often lengthy outages, and causes severe public outcry. But extreme weather can and does happen everywhere—no matter where in the country you operate. And one of the most common challenges utilities face is how to recoup the costs of restoring power after a significant weather event.
Natural gas matters: Changing estimates and today's low prices could cause bad policies
Authors: Smead Richard G.
Published: May 2012

Gasoline prices are at something like an all‐time high, and natural gas prices are at a ten‐year low. What a tumultuous, but promising, time for US natural gas. An obvious implication of this massive price disparity is that anywhere natural gas can compete with oil or with oil‐based energy pricing, many parties are eager to do so.
Electric regulation: The fracking buzz
Authors: Bowden Nicholas S.
Published: May 2012

A news media buzz has solidified around the economic and environmental impacts resulting from hydraulic fracturing in natural gas wells. The strictest opponents of hydraulic fracturing assert environmental degradation threatens ecological and human health to a degree that is high enough to require the government to prohibit use of the technique. Proponents assert the need to develop this newly accessed source of safe domestic energy as a key component to the “nation's clean energy future.”
The CpG island shore of the GLT‐1 gene acts as a methylation‐sensitive enhancer
Authors: Perisic Tatjana , Holsboer Florian , Rein Theo , Zschocke Jürgen
Published: May 2012

Astrocytic lineage commitment and brain region‐dependent specialization of glia are partly ascribed to epigenetic processes. Clearance of glutamate is an essential task, which astrocytes assume in a temporal‐spatial fashion by distinct glutamate transporter expression. Glutamate transporter subtype 1 (GLT‐1) is predominant in cortex (CTX), while it plays an inferior role in cerebellum (CER). Here, we set out to identify regulatory elements that could account for the differences in brain region‐specific activity as well as response to dexamethasone (DEX) or epigenetic factors. We found a distal promoter element at the shore of the CpG island exhibiting enhancer function in response to DEX in reporter gene assays. This shore region showed slight enrichment in repressive trimethyl‐histone H3 (Lys27) and under‐representation of acetyl‐histone H4 (H4ac) marks in DEX nonresponsive CER astrocytes as determined by chromatin immunoprecipitation. In addition, CpG sites of the shore region displayed higher methylation in CER than in CTX cells. Targeted in vitro methylation of CpG sites within the shore abrogated the stimulatory effects of DEX. Interestingly, the shore was characterized by a pronounced epigenetic plasticity in CTX cells since DEX exposure elicited an increase of H4ac in CTX in comparison to DEX nonresponsive CER. The transcriptional activity of this region was also affected by histone deacetylase inhibitors in a methylation‐ and brain region‐dependent manner. Together, our study highlights the impact of an epigenetically adaptive DNA element of the GLT‐1 promoter being decisive for brain region‐specific activity and reactivity. © 2012 Wiley Periodicals, Inc.
Fun and Accurate Static Balance Training to Enhance Fall Prevention Ability of Aged Adults: A Preliminary Study
Authors: Lai Chung‐Liang , Tseng Shiuan‐Yu , Huang Chien‐Hua , Pei Chun , Chi Wei‐Min , Hsu Liang‐Ching , Sun Tien‐Lung
Published: May 2012

Fall prevention is critical for aged adults as falling down has been cited as the number one cause of accidental death in aged adults. Static balance training is an effective method of increasing the balancing capacity in aged adults and reducing their fall risk. This article discusses a method that combines virtual reality (VR) technology with motion‐capture devices for aged adults to practice static balance training in a fun and accurate environment. The aged adults wore motion‐capture devices to interactively manipulate a three‐dimensional (3D) human model (HM) in a virtual environment to follow a 3D posture model (PM). The proposed method was implemented using commercial, off‐the‐shelf 3D tools. A preliminary usability study was conducted, and the results show that the parameters of PM design will affect the aged adult's posture control performance. Our method has several advantages over the currently existing approaches. First, by adjusting the PM parameters, different posture control programs could be designed to support customized static balance training. Second, collision detections between the HM and PM could be used to accurately monitor the posture control process and to interactively provide feedback to the trainee. Third, posture control quality could be quantitatively evaluated by analyzing the collision data between the HM and PM. The proposed method could be used to develop a fun, accurate, and customized static balancing capacity training environment for aged adults. © 2012 Wiley Periodicals, Inc.
New Concise and Efficient Synthesis of Rubrolides C and E via Intramolecular Wittig Reaction
Authors: Tale Nilesh P. , Shelke Amol V. , Tiwari Girdharilal B. , Thorat Prerana B. , Karade Nandkishor N.
Published: May 2012

A short total synthesis of rubrolides C and E has been achieved in four steps, using readily available 4‐methoxyacetophenone, 2‐bromoacetic acid, and the appropriate aromatic aldehyde, in 46 and 45% yield, respectively. Key reactions involved are α‐tosyloxylation of the aryl methyl ketone, intramolecular Wittig reaction, Knoevenagel condensation, and demethylation.
Synthesis of Halogenated α,β‐Unsaturated γ‐Butyrolactone Derivatives by Triphenylphosphine‐Catalyzed Cyclization of α‐Halogeno Ketones with Dialkyl Acetylenedicarboxylates (=Dialkyl But‐2‐ynedioates)
Authors: Asghari Sakineh , Khabbazi Habibi Ahmad
Published: May 2012

A Ph3P‐catalyzed cyclization of α‐halogeno ketones 2 with dialkyl acetylenedicarboxylates (=dialkyl but‐2‐ynedioates) 3 produced halogenated α,β‐unsaturated γ‐butyrolactone derivatives 4 in good yields (Scheme 1, Table). The presence of electron‐withdrawing groups such as halogen atoms at the α‐position of the ketones was necessary in this reaction. Cyclization of α‐chloro ketones resulted in higher yields than that of the corresponding α‐bromo ketones. Dihalogeno ketones similarly afforded the expected γ‐butyrolactone derivatives in high yields.
One‐Pot Four‐Component Synthesis of N2‐Alkyl‐N3‐[2‐(1,3,4‐oxadiazol‐2‐yl)aryl]benzofuran‐2,3‐diamines
Authors: Adib Mehdi , Sheikhi Ehsan , Karimzadeh Morteza , Bijanzadeh Hamid Reza , Amanlou Massoud
Published: May 2012

A simple synthesis of N2‐alkyl‐N3‐[2‐(1,3,4‐oxadiazol‐2‐yl)aryl]benzofuran‐2,3‐diamines 5 via a one‐pot four‐component reaction is described (Scheme 1). A mixture of N‐(isocyanoimino)triphenylphosphorane (1), a 2‐aminobenzoic acid 2, a 2‐hydroxybenzaldehyde 3, and an isocyanide 4 in absolute EtOH at room temperature undergoes a smooth reaction to afford 5 in excellent yields (Table).
New Efficient Synthetic Pathways to Tetrakis{p‐[(diethylphosphono)methyl]}calix[4]arene
Authors: Mourer Maxime , Regnouf‐de‐Vains Jean‐Bernard
Published: May 2012

Various operating conditions have been applied on tetrakis[p‐(halogenomethyl)]‐ and tetrakis[p‐(aminomethyl)]calix[4]arene derivatives to improve the synthesis of the 5,11,17,23‐tetrakis[(diethylphosphono)methyl]‐25,26,27,28‐tetrahydroxycalix[4]arene. Two new, high yield, synthetic pathways have been selected, involving, for the first one, the 25,26,27,28‐tetrahydroxy‐5,11,17,23‐tetrakis[(trimethylamino)methyl]calix[4]arene, tetraiodide, DMF, and 10 equiv. of triethyl phosphite ((EtO)3P), and, for the other one, the 5,11,17,23‐tetra(bromomethyl)‐25,26,27,28‐tetrahydroxycalix[4]arene, CH2Cl2, and only 4 equiv. of (EtO)2P.
A Straightforward Synthesis of 2‐[1‐Alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic Acid Derivatives via Domino Michael AdditionCyclization Reaction
Authors: Alizadeh Abdolali , Rezvanian Atieh
Published: May 2012

A new and efficient synthesis of 2‐[1‐alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic acid derivatives by a one‐pot three‐component reaction between primary amine, dialkyl acetylenedicarboxylate, and itaconic anhydride (=3,4‐dihydro‐3‐methylidenefuran‐2,5‐dione) is reported. The reaction was performed without catalyst and under solvent‐free conditions with excellent yields. Notably, the ready availability of the starting materials, and the high level of practicability of the reaction and workup make this approach an attractive complementary method to access to unknown 2‐[1‐alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic acid derivatives. The structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of domino Michael additioncyclization reaction is proposed (Scheme 2).
Synthesis and Characterization of Enantiomerically Pure cis‐ and trans‐3‐Fluoro‐2,4‐dioxa‐7‐aza‐3‐phosphadecalin 3‐Oxides as Acetylcholine Mimetics and Inhibitors of Acetylcholinesterase
Authors: Wächter Michael , Rüedi Peter
Published: May 2012

The title compounds, the P(3)‐axially and P(3)‐equatorially substituted cis‐ and trans‐configured 7‐benzyl‐3‐fluoro‐2,4‐dioxa‐7‐aza‐3‐phosphadecalin 3‐oxides (=7‐benzyl‐3‐fluoro‐2,4‐dioxa‐7‐aza‐3‐phosphabicyclo[4.4.0]decane 3‐oxides=5‐benzyl‐2‐fluorohexahydro‐4H‐1,3,2‐dioxaphosphorino[5,4‐b]pyridine 2‐oxides) were prepared (ee>99%) and fully characterized (Schemes 2 and 4). The absolute configurations were established from that of their precursors, the enantiomerically pure cis‐ and trans‐1‐benzyl‐3‐hydroxypiperidine‐2‐methanols which were unambiguously assigned. Being configuratively fixed and conformationally constrained phosphorus analogues of acetylcholine, they mimic rotamers of acetylcholine and are suitable probes for the investigation of molecular interactions with acetylcholinesterase. As determined by kinetic methods, the compounds are irreversible inhibitors of the enzyme displaying significant stereoselectivity.
Novel Synthesis of 2‐Alkylquinolizinium‐1‐olates and Their 1,3‐Dipolar Cycloaddition Reactions with Acetylenes
Authors: Gebert Andreas , Barth Max , Linden Anthony , Widmer Ulrich , Heimgartner Heinz
Published: May 2012

Several 2‐alkylquinolizinium‐1‐olates 9, i.e., heterobetaines, were prepared from ketone 11, the latter being readily available either from pyridine‐2‐carbaldehyde via a Grignard reaction, followed by oxidation with MnO2, or from 2‐picolinic acid (=pyridine‐2‐carboxylic acid) via the corresponding Weinreb amide and subsequent Grignard reaction. Mesoionic heterobetaines such as quinolizinium derivatives have the potential to undergo cycloaddition reactions with double and triple bonds, e.g., 1,3‐dipolar cycloadditions or DielsAlder reactions. We here report on the scope and limitations of cycloaddition reactions of 2‐alkylquinolizinium‐1‐olates 9 with electron‐poor acetylene derivatives. As main products of the reaction, 5‐oxopyrrolo[2,1,5‐de]quinolizines (=‘[2.3.3]cyclazin‐5‐ones’) 19 were formed via a regioselective [2+3] cycloaddition, and cyclohexadienone derivatives, formed via a DielsAlder reaction, were obtained as side products. The structures of 2‐benzylquinolizinium‐1‐olate (9a) and two ‘[2.3.3]cyclazin‐5‐ones’ 19i and 19l were established by X‐ray crystallography.
1,2‐Bis(trifluoromethyl)ethene‐1,2‐dicarbonitrile and Vinyl Ethers: Cyclic Ketene Imines on the Pathway to 1 : 2 Cycloadducts
Authors: Urrutia Desmaison Gonzalo , Huisgen Rolf , Nöth Heinrich
Published: May 2012

(E)‐ and (Z)‐1,2‐bis(trifluoromethyl)ethene‐1,2‐dicarbonitrile (BTE; (=E)‐ and (Z)‐1,2‐bis(trifluoromethyl)but‐2‐enedinitrile) were reacted with an excess of methyl vinyl ether, used as solvent, and furnished 1 : 2 adducts 6 (54%) and cyclobutanes 3 as 1 : 1 adducts (41%). The four diastereoisomeric bis‐adducts 6 (different ratios from (E)‐ and (Z)‐BTE) are derivatives of 1‐azabicyclo[4.2.0]oct‐5‐ene; X‐ray analyses and 19F‐NMR spectra revealed their structures. Since the cyclobutanes 3 are resistant to vinyl ether, the pathways leading to mono‐ and bis‐adducts must compete on the level of the intermediate l,4‐zwitterions 1 and 2. The latter either cyclize to the cyclobutanes 3 or to six‐membered cyclic ketene imines 8 which accept a second molecule of vinyl ether to yield the bis‐adducts 6. The occurrence of the highly strained ketene imines 8 gains credibility by comparison to stable seven‐membered cyclic ketene imines recently reported.
Poverty and Single Parenting: Relations with Preschoolers' Cortisol and Effortful Control
Authors: Zalewski Maureen , Lengua Liliana J. , Fisher Philip A. , Trancik Anika , Bush Nicole R. , Meltzoff Andrew N.
Published: May 2012

Poverty and single parent status, which often co‐occur, have been shown to relate to lower effortful control, and this may be in part due to disruptions in hypothalamic–pituitary–adrenal (HPA) axis activity. Both poverty and single parent status may compromise parenting, which in turn may disrupt HPA axis activity and the development of effortful control. We examined whether parenting and HPA axis activity accounted for the effects of poverty and single parent status on the development of effortful control in preschool children (N = 78). Effortful control was measured at two time points, 6 months apart. Individually, poverty and single parent status were related to blunted HPA axis activity, characterized by low AM and PM cortisol. However, when examined together, the effects were present only for preschoolers whose parents were in poverty. Parental warmth and negativity accounted for the relations between poverty and blunted cortisol. Blunted cortisol was related to lower effortful control at Time 2. These results suggest a pathway through which poverty may impact children's developing effortful control through parenting, which in turn may shape HPA axis activity. Copyright © 2012 John Wiley & Sons, Ltd.
Asymmetric Intermolecular Mizoroki‐Heck Reaction: From Phosphine/Phosphinite‐Nitrogen to Phosphite‐Nitrogen Ligands
Authors: Diéguez Montserrat , Pàmies Oscar
Published: May 2012

This review discusses the latest developments in ligand design for the Pd‐catalyzed asymmetric intermolecular Mizoroki‐Heck reaction, from the successful phosphine/phosphinite‐nitrogen ligands to the recently reported phosphite‐nitrogen ligands. The presence of a biaryl phosphite group offers several advantages as a ligand scaffold for this process.
A simple and fast method for profiling microRNA expression from low‐input total RNA by microarray
Authors: Zhao Botao , Jin Li , Wei Jiali , Ma Zhongliang , Jiang Weijun , Ma Lijun , Jin Youxin
Published: May 2012

Analysis of mature microRNA (miRNA) expression is important to understand its physiological functions and pathological implications. Microarray is a powerful technology to profile global miRNA expression. In this study, we developed a rapid miRNA labeling method by which miRNA was directly labeled in total RNA for microarray detection. This method consists of RNA tailing by poly(A) polymerase, reverse transcription, and template‐switching by moloney murine leukemia virus (MMLV) reverse transcriptase. After these reactions, the small RNA cDNA was ready for labeling for microarray detection. The whole process of prearray sample preparation was dramatically shortened to 2 h. Furthermore, this method allows very limited starting total RNA (100 ng) for microarray analysis. Our data showed that the results from our method were highly consistent with that of real‐time polymerase chain reaction (PCR). 2012 IUBMB IUBMB Life, 64(7): 612–616, 2012