bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Recombinant Proteins as Cross‐Linkers for Hydrogelations
Authors: Wang Huaimin , Shi Yang , Wang Ling , Yang Zhimou
Published: May 2013

Review: 60 refs.
ChemInform Abstract: Coordination Polymer Gels with Important Environmental and Biological Applications
Authors: Jung Jong Hwa , Lee Ji Ha , Silverman Julian R. , John George
Published: May 2013

Review: 45 refs.
ChemInform Abstract: Nanotoxicity Assessment of Quantum Dots: From Cellular to Primate Studies
Authors: Yong Ken‐Tye , Law Wing‐Cheung , Hu Rui , Ye Ling , Liu Liwei , Swihart Mark T. , Prasad Paras N.
Published: May 2013

Review: 93 refs.
ChemInform Abstract: Biosensors Based on Nanomechanical Systems
Authors: Tamayo Javier , Kosaka Priscila M. , Ruz Jose J. , San Paulo Alvaro , Calleja Montserrat
Published: May 2013

Review: 147 refs.
ChemInform Abstract: Prebiotic Chemistry in Icy Grain Mantles in Space. An Experimental and Observational Approach
Authors: Munoz Caro Guillermo M. , Dartois Emmanuel
Published: May 2013

Review: 89 refs.
An optogenetic tool for the activation of endogenous diaphanous‐related formins induces thickening of stress fibers without an increase in contractility
Authors: Rao Megha Vaman , Chu Pei‐Hsuan , Hahn Klaus Michael , Zaidel‐Bar Ronen
Published: May 2013

We have developed an optogenetic technique for the activation of diaphanous‐related formins. Our approach is based on fusion of the light‐oxygen‐voltage 2 domain of Avena sativa Phototrophin1 to an isolated Diaphanous Autoregulatory Domain from mDia1. This “caged” diaphanous auto‐regulatory domain was inactive in the dark but in the presence of blue light rapidly activated endogenous diaphanous‐related formins. Using an F‐actin reporter, we observed filopodia and lamellipodia formation as well as a steady increase in F‐actin along existing stress fibers, starting within minutes of photo‐activation. Interestingly, we did not observe the formation of new stress fibers. Remarkably, a 1.9‐fold increase in F‐actin was not paralleled by an increase in myosin II along stress fibers and the amount of tension generated by the fibers, as judged by focal adhesion size, appeared unchanged. Our results suggest a decoupling between F‐actin accumulation and contractility in stress fibers and demonstrate the utility of photoactivatable diaphanous autoregulatory domain for the study of diaphanous‐related formin function in cells. © 2013 Wiley Periodicals, Inc.
Patterns of cortical reorganization in the adult marmoset after a cervical spinal cord injury
Authors: Bowes Charnese , Burish Mark , Cerkevich Christina , Kaas Jon
Published: May 2013

In the present study, we used microelectrode recordings of multiunit responses to evaluate patterns of the reactivation of somatosensory cortex after sensory loss produced by spinal cord lesions in the common marmoset (Callithrix jacchus). These New World monkeys have become a popular model in studies of cortical organization and function. Primary somatosensory cortex and adjoining somatosensory areas can become extensively deactivated by lesions of somatosensory afferents as they ascend in the dorsal columns of the cervical spinal cord. Six to 7 weeks after complete lesions of the cuneate fasciculus subserving the forelimb at cervical levels 5–6, the hand region in contralateral areas 3b and 1 was reactivated by inputs from the forelimb, but excluded representations of some or all digits. In a similar manner, recording sites from the forelimb region of areas 2–5 responded to parts of the forelimb but not to digits after an extensive lesion of the contralateral cuneate fasciculus at C5–C6. Lesions that damaged only the gracile fasciculus or a small percentage of the cuneate fasciculus did not produce changes in the gross hand representation in contralateral areas 3b, 3a, 1, and 2. Finally, a complete but lower lesion of the cuneate fasciculus at C8 produced some abnormalities in the reactivation, but the digits were represented. The results indicate that areas 3a, 3b, 1, and 2–5 of the somatosensory cortex are extensively reactivated after large, apparently complete lesions of the contralateral cuneate fasciculus, but afferents from the digits may not contribute to their reactivation. J. Comp. Neurol. 521:3451‐3463, 2013. © 2013 Wiley Periodicals, Inc.
Upregulation of insulin‐like growth factor and interleukin 1β occurs in neurons but not in glial cells in the cochlear nucleus following cochlear ablation
Authors: Fuentes‐Santamaría Verónica , Alvarado Juan Carlos , Gabaldón‐Ull María Cruz , Manuel Juiz José
Published: May 2013

One of the main mechanisms used by neurons and glial cells to promote repair following brain injury is to upregulate activity‐dependent molecules such as insulin‐like growth factor 1 (IGF‐1) and interleukin‐1β (IL‐1β). In the auditory system, IGF‐1 is crucial for restoring synaptic transmission following hearing loss; however, whether IL‐1β is also involved in this process is unknown. In this study, we evaluated the expression of IGF‐1 and IL‐1β within neurons and glial cells of the ventral cochlear nucleus in adult rats at 1, 7, 15, and 30 days following bilateral cochlear ablation. After the lesion, significant increases in both the overall mean gray levels of IGF‐1 immunostaining and the mean gray levels within cells of the cochlear nucleus were observed at 1, 7, and 15 days compared with control animals. The expression and distribution of IL‐1β in the ventral cochlear nucleus of ablated animals was temporally and spatially correlated with IGF‐1. We also observed a lack of colocalization between IGF‐1 and IL‐1β with either astrocytes or microglia at any of the time points following ablation. These results suggest that the upregulation of IGF‐1 and IL‐1β levels within neurons—but not within glial cells—may reflect a plastic mechanism involved in repairing synaptic homeostasis of the overall cellular environment of the cochlear nucleus following bilateral cochlear ablation. J. Comp. Neurol. 521:3478‐3499, 2013. © 2013 Wiley Periodicals, Inc.
Migration of Bone Marrow‐Derived Cells Into the Central Nervous System in Models of Neurodegeneration
Authors: Lampron Antoine , Pimentel‐Coelho Pedro M. , Rivest Serge
Published: May 2013

Microglia are the brain‐resident macrophages tasked with the defense and maintenance of the central nervous system (CNS). The hematopoietic origin of microglia has warranted a therapeutic potential for the hematopoietic system in treating diseases of the CNS. However, migration of bone marrow‐derived cells (BMDC) into the CNS is a marginal event under normal, healthy conditions. A busulfan‐based chemotherapy regimen was used for bone marrow transplantation in wild‐type mice before subjecting them to a hypoxic–ischemic brain injury or in APP/PS1 mice prior to the formation of amyloid plaques. The cells were tracked and analyzed throughout the development of the pathology. The efficacy of a preventive macrophage colony‐stimulating factor (M‐CSF) treatment was also studied to highlight the effects of circulating monocytes in hypoxic–ischemic brain injury. Such an injury induces a strong migration of BMDC into the CNS, without the need for irradiation. These migrating cells do not replace the entire microglial pool but rather are confined to the sites of injury for several weeks, suggesting that they could perform specific functions. M‐CSF showed neuroprotective effects as a preventive treatment. In APP/PS1 mice, the formation of amyloid plaques was sufficient to induce the entry of cells into the parenchyma, though in low numbers. This study confirms that BMDC infiltrate the CNS in animal models for stroke and Alzheimer's disease and that peripheral cells can be targeted to treat affected regions of the CNS. J. Comp. Neurol. 521:3863–3876, 2013. © 2013 Wiley Periodicals, Inc.
A Chemical Lift‐off Process: Removing Non‐Specific Adsorption in an Electrochemical Epstein–Barr Virus Immunoassay
Authors: Stratmann Lutz , Gebala Magdalena , Schuhmann Wolfgang
Published: May 2013

Upon contact of sensor surfaces with complex biological samples containing a variety of different proteins, non‐specific adsorption hampers the high‐sensitive detection of the analyte in question. To substantially decrease the impact of non‐specific adsorption at thiol‐based self‐assembled monolayers, a chemical lift‐off process is introduced. A sequence of local hydrolysis of isooctyl 3‐mercaptopropionate, covalent binding of an antigen against the Epstein–Barr virus (EBV), stepwise incubation with a serum sample possibly containing the EBV antibody and an enzyme‐labeled anti‐human antibody is completed with a lift‐off by integral hydrolysis of the remaining ester groups at the self‐assembled monolayer. The cleavage of the ester removes any non‐specifically bound protein during a following stringent washing step. The substantial improvement of the detection limit of an electrochemical immunoassay against EBV using native recombinant antigens, their immobilization after local deprotection using a scanning electrochemical microscope (SECM) and the local read‐out using the generator–collector mode of SECM with redox cycling amplification demonstrates the successful application of the proposed lift‐off procedure.
Value and information: A profit maximizing strategy for Maxwell's demon
Authors: Morck Randall , Morowitz Harold
Published: May 2013

Applications of Lagrange's method of undetermined multipliers in physics and economics suggest some analogies between the two disciplines. Applying Jaynes' approach to information theory reveals the long standing problem of Maxwell's demon in thermodynamics as a constrained optimization problem where information and energy are dual concepts. Temperature emerges as the energetic price of information. This approach highlights the economic features of the Maxwell demon discussed by Bridgman. It also suggests that an analog to temperature (or the price of information) should be present in any optimization problem constrained by costly information. A trivial economics example is presented where generalized temperature measures informational efficiency in the sense of Grossman and Stiglitz.
Order‐disorder transitions in the behavior of ant societies
Authors: Miramontes Octavio
Published: May 2013

Systems of many interacting elements may exhibit both optimal information processing capabilities and optimal adaptive capacity when poised in a state at the boundary separating chaos from order. Ant societies, composed of interacting chaotic individuals, which can generate regular cycles in the activity of the colony, provide one of the very first examples of this phenomenon. They self‐organize to attain nest densities at which the transfer of information, per capita activations and the information capacity of the colonies are maximal. At such densities, ant colonies are poised in the neighborhood of a chaos‐order phase transition.
Complex systems in drug research: II. The ligand—active site—water confluence as a complex system
Authors: Kier Lemont B. , Testa Bernard
Published: May 2013

Three partners are involved in any pharmacological phenomenon examined at the molecular level, namely a functional biomacromolecule (e.g., receptor or enzyme), a ligand molecule whose binding to the active site of the macromolecule triggers a response, and water which acts as a structural component and as a solvent. Some of the molecular events involved in initial steps of pharmacological responses are examined here as emergent properties of the triad active site‐ligand‐water, a complex system seldom viewed as such. For example, the exquisite selectivity and efficiency of long‐ and short‐range recognition of ligands may rest on more than simple random encounters. The emergent property of function suggests the possibility that active sites are maintained near criticality by low‐levels of endogenous ligands.
Genetic learning in strategic form games
Authors: Dawid Herbert , Mehlmann Alexander
Published: May 2013

We analyze the learning behavior of a Simple Genetic Algorithm in symmetric 3 × 3 Strategic‐Form‐Games. In cases of contests within one population and also between two populations the behavior of the SGA is compared with the behavior of the replicator dynamics and is analyzed with respect to equilibrium concepts in evolutionary game theory. Furthermore conservative non‐adaptive strings are added to the population which lead to convergence to an equilibrium even in “GA‐deceptive” games where the equilibrium can not be reached by GAs using only selection and crossover.
Modeling the complexity of genetic networks: Understanding multigenic and pleiotropic regulation
Authors: Somogyi Roland , Sniegoski Carol Ann
Published: May 2013

Molecular genetics presents an increasingly complex picture of the genome and biological function. Evidence is mounting for distributed function, redundancy, and combinatorial coding in the regulation of genes. Satisfactory explanation will require the concept of a parallel processing signaling network. Here we provide an introduction to Boolean networks and their relevance to present‐day experimental research. Boolean network models exhibit global complex behavior, self‐organization, stability, redundancy and periodicity, properties that deeply characterize biological systems. While the life sciences must inevitably face the issue of complexity, we may well look to cybernetics for a modeling language such as Boolean networks which can manageably describe parallel processing biological systems and provide a framework for the growing accumulation of data. We finally discuss experimental strategies and database systems that will enable mapping of genetic networks. The synthesis of these approaches holds an immense potential for new discoveries on the intimate nature of genetic networks, bringing us closer to an understanding of complex molecular physiological processes like brain development, and intractable medical problems of immediate importance, such as neurodegenerative disorders, cancer, and a variety of genetic diseases.
Effect of citric acid and starch as emulsifier on phase formation and crystallite size of lanthanum oxide nanoparticles
Authors: Bojari Hamidreza , Malekzadeh Azim , Ghiasi Mahnaz , Gholizadeh Ahmad , Azargohar Ramin , Kumar Dalai Ajay
Published: May 2013

Lanthanum oxide nanoparticles were synthesized via thermal decomposition method of the lanthanum nitrate in the presence of citric acid or starch as emulsifier. The effects of emulsifier and calcination temperature were investigated on the phase transformation and particle size distribution of the products. La2O3 nanoparticles were synthesized by drying lanthanum precursor and emulsifier solution, followed by calcination process at 600 and 900°C, respectively. Products were characterized by Fourier Transform Infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), thermal analysis (TG/DTA) and nitrogen adsorption method (porous characteristics). The morphology of the samples analyzed using scanning electron microscopy (SEM). Average crystallite size of the products was calculated by XRD data and average particle size was measured from the TEM micrographs. Lanthanum dioxycarbonate in different forms of the tetragonal and monoclinic is crystallized in the presence of citric acid and starch during the calcination at 600°C, respectively. The hexagonal structure, however, is detected as the only crystalline phase formed by calcination at 900°C.
Magnetic and electric field characterization of La2CoMnO6 crystals doped with Pb
Authors: Yankova L. , Milenov T. I. , Rafailov P. M. , Avdeev G. V. , Veleva M. N. , Gosopodinov M. M.
Published: May 2013

Crystals of La2CoMnO6 doped with Pb were successfully grown by the high temperature solution growth method and their magnetic and transport properties were studied. The examined crystal is found to have predominantly ordered Co2+/Mn4+ structure with randomly distributed Mn3+ substituting Co2+. A relaxor‐like temperature dependence of the dielectric constant with relaxation maximum is established in the temperature interval 180–210 K. On the base of the dc‐conductivity data, it is assumed that the charge transport in the interval 180–350 K is governed by small‐polaron hopping, whose onset coincides with the Curie temperature.
Reversible Capture of SO2 through Functionalized Ionic Liquids
Authors: Yang Dezhong , Hou Minqiang , Ning Hui , Ma Jun , Kang Xinchen , Zhang Jianling , Han Buxing
Published: May 2013

Emission of SO2 in flue gas from the combustion of fossil fuels leads to severe environmental problems. Exploration of green and efficient methods to capture SO2 is an interesting topic, especially at lower SO2 partial pressures. In this work, ionic liquids (ILs) 1‐(2‐diethylaminoethyl)‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([Et2NEMim][Tf2N]) and 1‐(2‐diethylaminoethyl)‐3‐methylimidazolium tetrazolate ([Et2NEMim][Tetz]) were synthesized. The performances of the two ILs to capture SO2 were studied under different conditions. It was demonstrated that the ILs were very efficient for SO2 absorption. The [Et2NEMim][Tetz] IL designed in this work could absorb 0.47 g gIL−1 at 0.0101 MPa SO2 partial pressure, which is the highest capacity reported to date under the same conditions. The main reason for the large capacity was that both the cation and the anion could capture SO2 chemically. In addition, the IL could easily be regenerated, and the very high absorption capacity and rapid absorption/desorption rates were not changed over five repeated cycles.
A Water‐free Low Temperature Process for Atomic Layer Deposition of Al2O3 Films
Authors: Guo Jiao‐Jiao , Li Ming‐Da , Sun Qing‐Qing , Yang Wen , Zhou Peng , Ding Shi‐Jin , Zhang David Wei
Published: May 2013

A new low temperature atomic layer deposition (LT‐ALD) Al2O3 process using trimethylaluminum (TMA) and acetic acid (CH3COOH) is studied both theoretically and experimentally. The atomistic mechanisms of the two deposition half‐cycles on Al‐CH3*, Al‐OH*, and Al(η2‐O2CCH3)* are investigated using density functional theory (DFT). The experimental demonstrations are performed on Si substrates over the growth temperature range 75–400°C. Consistent with the DFT simulation, lower linear growth rate and shorter required oxidant purge times are observed at 90°C, when compared to LT‐ALD Al2O3 using H2O as the oxidant. The chemical characteristics of the Al2O3 films grown with both CH3COOH at 90°C and H2O at 100°C are determined and compared using X‐ray photoelectron spectroscopy (XPS).
Room‐Temperature ALD of Metal Oxide Thin Films by Energy‐Enhanced ALD
Authors: Potts Stephen E. , Profijt Harald B. , Roelofs Robin , Kessels Wilhelmus M. M.
Published: May 2013

Room‐temperature atomic layer deposition (RT‐ALD) processes are of interest for applications using temperature‐sensitive substrates. Challenges with RT‐ALD arise when the precursors are not sufficiently volatile, purge times become impractically long, and precursors or co‐reactants are unreactive with the surface species. In several cases, the latter two challenges can be overcome using energy‐enhanced ALD. Here, we demonstrate RT‐ALD (25°C) processes for Al2O3, TiO2, and SiO2 from trimethylaluminum (Al(CH3)3, TMA), titanium(IV) tetraisopropoxide (Ti(OiPr)4, TTIP), and bis(diethylamino)silane (SiH2(NEt2)2, BDEAS) precursors with an O2 plasma or O3 gas as co‐reactants. Saturated RT‐ALD growth was obtained for all O2 plasma processes and TMA/O3, whereas the TTIP/O3 and BDEAS/O3 processes gave no growth. Using these and literature results, the criteria for viable RT‐ALD processes are discussed.
Photocatalytic Properties of WO3/TiO2 Core/Shell Nanofibers prepared by Electrospinning and Atomic Layer Deposition
Authors: Szilágyi Imre Miklós , Santala Eero , Heikkilä Mikko , Pore Viljami , Kemell Marianna , Nikitin Timur , Teucher Georg , Firkala Tamás , Khriachtchev Leonid , Räsänen Markku , Ritala Mikko , Leskelä Markku
Published: May 2013

Core WO3 nanofibers (140–300 nm in diameter, several hundred µm long) are made by a novel, water‐based electrospinning process using ammonium metatungstate (AMT) and polyvinylpyrrolidone (PVP) as precursors. TiO2 shells (1.5–20 nm) are grown by atomic layer deposition (ALD) using TiCl4 and water at 250°C. The WO3/TiO2 composite fibers are analyzed using X‐ray diffraction (XRD), scanning electron microscopy (SEM)‐energy dispersive X‐ray (EDX), transmission electron microscopy (TEM), Raman spectroscopy (RS), UV‐Vis spectroscopy, and X‐ray photoelectron spectroscopy (XPS). The optimal photocatalytic conversion under visible light is reached by the WO3/1.5 nm TiO2 nanofibers, which have higher activity compared to bare WO3 and Degussa TiO2. Thicker TiO2 layers fill the pores of the nanowires and reduce the specific surface area, weakening the photocatalytic activity.
Influence of Subsurface Hybrid Material Growth on the Mechanical Properties of Atomic Layer Deposited Thin Films on Polymers
Authors: Sun Yujie , Padbury Richard P. , Akyildiz Halil I. , Goertz Matthew P. , Palmer Jeremy A. , Jur Jesse S.
Published: May 2013

The mechanical properties of atomic layer deposition (ALD) coatings play a key role in their long‐term use as encapsulation barriers for organic‐based, flexible, electronic devices. Nano‐indentation characteristics and flexure testing of nanometer‐scale alumina on polyamide 6 (PA6) films are investigated to determine the influence of a sub‐surface hybrid layer formed during the ALD process. This hybrid layer is observed to affect the mechanical performance of the thin films, in particular at lower processing temperatures. This work has important consequences on how ALD materials need to be applied and evaluated on polymers for application as encapsulation barrier layers.
Molecular Hybrid Structures by Atomic Layer Deposition – Deposition of Alq3, Znq2 and Tiq4 (q = 8‐hydroxyquinoline)
Authors: Nilsen Ola , Haug Kristoffer Robin , Finstad Terje , Fjellvåg Helmer
Published: May 2013

Atomic layer deposition (ALD) is traditionally used for deposition of inorganic compounds, metals, organic polymers, and hybrid inorganic/organic materials. In all these materials, the structural framework is based on covalent or metallic bonds. The present paper demonstrates the growth of thin films of metal‐organic films in which weak Van der Waals forces are important. Thin films of metal quinolines based on 8‐hydroxyquinoline (q) and aluminum (Alq3), zinc (Znq2), and titanium (possibly Tiq4) have been deposited using ALD in the temperature range 85–200 °C. The growth rates decrease with increasing temperature from 0.7–0.4 nm per cycle at 85 °C, to zero at 200 °C. The growth dynamics have been investigated using a quartz crystal microbalance (QCM). It is found that an excess of metal precursor will etch the films. The Alq3 material is stable towards exposure to water during deposition. The photoluminescent properties of selected metal quinoline films are reported.
Body fluid and tissue analysis using filter paper sampling support prior to LC‐MS/MS: Application to fatal overdose with colchicine
Authors: Lauer Estelle , Widmer Christèle , Versace François , Staub Christian , Mangin Patrice , Sabatasso Sara , Augsburger Marc , Déglon Julien
Published: May 2013

Because of the various matrices available for forensic investigations, the development of versatile analytical approaches allowing the simultaneous determination of drugs is challenging. The aim of this work was to assess a liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) platform allowing the rapid quantification of colchicine in body fluids and tissues collected in the context of a fatal overdose. For this purpose, filter paper was used as a sampling support and was associated with an automated 96‐well plate extraction performed by the LC autosampler itself. The developed method features a 7‐min total run time including automated filter paper extraction (2 min) and chromatographic separation (5 min). The sample preparation was reduced to a minimum regardless of the matrix analyzed. This platform was fully validated for dried blood spots (DBS) in the toxic concentration range of colchicine. The DBS calibration curve was applied successfully to quantification in all other matrices (body fluids and tissues) except for bile, where an excessive matrix effect was found. The distribution of colchicine for a fatal overdose case was reported as follows: peripheral blood, 29 ng/ml; urine, 94 ng/ml; vitreous humour and cerebrospinal fluid, < 5 ng/ml; pericardial fluid, 14 ng/ml; brain, < 5 pg/mg; heart, 121 pg/mg; kidney, 245 pg/mg; and liver, 143 pg/mg. Although filter paper is usually employed for DBS, we report here the extension of this alternative sampling support to the analysis of other body fluids and tissues. The developed platform represents a rapid and versatile approach for drug determination in multiple forensic media. Copyright © 2013 John Wiley & Sons, Ltd.
Adenosine signaling inhibits CIITA‐mediated MHC class II transactivation in lung fibroblast cells
Authors: Fang Mingming , Xia Jun , Wu Xiaoyan , Kong Hui , Wang Hong , Xie Weiping , Xu Yong
Published: May 2013

Efficient antigen presentation by major histocompatibility complex (MHC) molecules represents a critical process in adaptive immunity. Class II transactivator (CIITA) is considered the master regulator of MHC class II (MHC II) transcription. Previously, we have shown that CIITA expression is upregulated in smooth muscle cells deficient in A2b adenosine receptor. Here, we report that treatment with the adenosine receptor agonist adenosine‐5′N‐ethylcarboxamide (NECA) attenuated MHC II transcription in lung fibro‐blast cells as a result of CIITA repression. Further analysis revealed that NECA preferentially abrogated CIITA transcription through promoters III and IV. Blockade with a selective A2b receptor antagonist MRS‐1754 restored CIITA‐dependent MHC II transactivation. Forskolin, an adenylyl cyclase activator, achieved the same effect as NECA. A2b signaling repressed CIITA transcription by altering histone modifications and recruitment of key factors on the CIITA promoters in a STAT1‐dependent manner. MRS‐1754 blocked the antagonism of transforming growth factor beta (TGF‐β) in CIITA induction by interferon gamma (IFN‐γ), alluding to a potential dialogue between TGF‐β and adenosine signaling pathways. Finally, A2b signaling attenuated STAT1 phosphorylation and stimulated TGF‐β synthesis. In conclusion, we have identified an adenosine‐A2b receptor‐adenylyl cyclase axis that influences CIITA‐mediated MHC II transactivation in lung fibroblast cells and as such have provided invaluable insights into the development of novel immune‐modulatory strategies.
Syntheses of Hydrazino Peptides and Conjugates
Authors: Panda Siva S. , El‐Nachef Claudia , Bajaj Kiran , Katritzky Alan R.
Published: May 2013

(α‐Benzyloxycarbonyl‐aminoacyl)benzotriazolides (Cbz = benzyloxycarbonyl) underwent a coupling reaction with α‐hydrazino acids under microwave irradiation to form hybrid hydrazino dipeptides (42–71 %). Chiral acylations of β‐N‐Cbz‐α‐hydrazino acylbenzotriazolides were successfully carried out with N‐, S‐, O‐, and C‐nucleophiles in yields of 49–88 %.
Following the Lead from Nature: Divergent Pathways in Natural Product Synthesis and Diversity‐Oriented Synthesis
Authors: Serba Christelle , Winssinger Nicolas
Published: May 2013

This microreview discusses recent efforts in chemical synthesis to design divergent pathways either to access diverse natural products from a common intermediate or to produce diverse libraries of compounds reminiscent of natural products. These efforts are generally based on the development and use of powerful complexity‐generating reactions and cascade reactions. A panel of eighteen examples is used to illustrate different strategies.
Measuring the exposome: A powerful basis for evaluating environmental exposures and cancer risk
Authors: Wild Christopher P. , Scalbert Augustin , Herceg Zdenko
Published: May 2013

Advances in laboratory sciences offer much in the challenge to unravel the complex etiology of cancer and to therefore provide an evidence‐base for prevention. One area where improved measurements are particularly important to epidemiology is exposure assessment; this requirement has been highlighted through the concept of the exposome. In addition, the ability to observe genetic and epigenetic alterations in individuals exposed to putative risk factors also affords an opportunity to elucidate underlying mechanisms of carcinogenesis, which in turn may allow earlier detection and more refined molecular classification of disease. In this context the application of omics technologies to large population‐based studies and their associated biobanks raise exciting new avenues of research. This review considers the areas of genomics, transcriptomics, epigenomics and metabolomics and the evidence to date that people exposed to well‐defined factors (for example, tobacco, diet, occupational exposures, environmental pollutants) have specific omics profiles. Although in their early stages of development these approaches show promising evidence of distinct exposure‐derived biological effects and indicate molecular pathways that may be particularly relevant to the carcinogenic process subsequent to environmental and lifestyle exposures. Such an interdisciplinary approach is vital if the full benefits of advances in laboratory sciences and investments in large‐scale prospective cohort studies are to be realized in relation to cancer prevention. Environ. Mol. Mutagen. 54:480‐499, 2013. © 2013 Wiley Periodicals, Inc.
ERBB4 confers metastatic capacity in Ewing sarcoma
Authors: Mendoza‐Naranjo Ariadna , El‐Naggar Amal , Wai Daniel H. , Mistry Priti , Lazic Nikola , Ayala Fernanda Rocha Rojas , da Cunha Isabela Werneck , Rodriguez‐Viciana Pablo , Cheng Hongwei , Tavares Guerreiro Fregnani Jose H. , Reynolds Patrick , Arceci Robert J. , Nicholson Andrew , Triche Timothy J. , Soares Fernando A. , Flanagan Adrienne M. , Wang Yuzhuo Z. , Strauss Sandra J. , Sorensen Poul H.
Published: May 2013

Metastatic spread is the single‐most powerful predictor of poor outcome in Ewing sarcoma (ES). Therefore targeting pathways that drive metastasis has tremendous potential to reduce the burden of disease in ES. We previously showed that activation of the ERBB4 tyrosine kinase suppresses anoikis, or detachment‐induced cell death, and induces chemoresistance in ES cell lines in vitro. We now show that ERBB4 is transcriptionally overexpressed in ES cell lines derived from chemoresistant or metastatic ES tumours. ERBB4 activates the PI3K‐Akt cascade and focal adhesion kinase (FAK), and both pathways contribute to ERBB4‐mediated activation of the Rac1 GTPase in vitro and in vivo. ERBB4 augments tumour invasion and metastasis in vivo, and these effects are blocked by ERBB4 knockdown. ERBB4 expression correlates significantly with reduced disease‐free survival, and increased expression is observed in metastatic compared to primary patient‐matched ES biopsies. Our findings identify a novel ERBB4‐PI3K‐Akt‐FAK‐Rac1 pathway associated with aggressive disease in ES. These results predict that therapeutic targeting of ERBB4, alone or in combination with cytotoxic agents, may suppress the metastatic phenotype in ES.
Eating Disorders with and without Comorbid Depression and Anxiety: Similarities and Differences in a Clinical Sample of Children and Adolescents
Authors: Hughes Elizabeth K. , Goldschmidt Andrea B. , Labuschagne Zandre , Loeb Katharine L. , Sawyer Susan M. , Grange Daniel Le
Published: May 2013

Objective

This study aimed to describe and compare the demographic and clinical characteristics of children and adolescents with an eating disorder (ED) and comorbid depression or anxiety.

Method

Data were drawn from intake assessments of children and adolescents at a specialist ED clinic. Demographic characteristics (e.g. age and gender) and clinical characteristics (e.g. body mass, binge eating and purging) were compared between 217 ED participants without comorbidity, 32 with comorbid anxiety, 86 with comorbid depression and 36 with comorbid anxiety and depression.

Results

The groups with comorbid depression had more complex and severe presentations compared with those with an ED and no comorbid disorder and those with comorbid anxiety alone, especially in regard to binge eating, purging, dietary restraint and weight/shape concerns.

Discussion

Depression and anxiety were differentially related to clinical characteristics of EDs. The findings have implications for understanding the relations between these disorders and their potential to impact outcome of ED treatments. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.
Variability of internal frontal bore breaking above Opouawe Bank methane seep area (New Zealand)
Authors: van Haren Hans , Greinert Jens
Published: May 2013

Large internal wave breaking is observed exceeding a vertical array of 61 high‐resolution temperature sensors at 1 m intervals between 7 and 67 m above the bottom. The array was moored for 5 days at 969 m of Opouawe Bank, New Zealand, a known methane seep area. As breaking internal waves dominate sediment resuspension above sloping topography in other ocean areas, they are expected to also influence methane transport. Despite being visible in single beam echosounder data, indications for turbulence due to rising gas bubbles are not found in the present 1 Hz sampled temperature records. Likely, the mooring was too far away from the very localized bubble release spot. Instead, the temperature sensors show detailed internal wave‐turbulence transitions. Every tidal cycle, a solibore (a frontal turbulent bore with a train of trailing solitary waves) changes shape and intensity. These solibores are highly turbulent and they restratify the bottom boundary layer, thereby maintaining efficient mixing. Details of different turbulent bore developments are discussed. Averaged over a few tidal cycles and over the sensors range, mean vertical eddy diffusivity amounts to 3 ± 1 × 10−3 m2 s−1 and mean turbulent kinetic energy dissipation to 1.6 ± 0.7 × 10−7 W kg−1, with variations over 4 orders of magnitude. Such turbulence will affect the distribution of dissolved methane and other geochemical species in the lower 100–150 m above the bottom and their release from the bottom. The above mean values are remarkably similar to those found at various other sites in the NE Atlantic Ocean.
Subduction and slab breakoff controls on Asian indentation tectonics and Himalayan western syntaxis formation
Authors: Capitanio Fabio A. , Replumaz Anne
Published: May 2013

We test the link between large‐scale Asian continent deformations and Indian slab subduction and breakoff during convergence by means of three‐dimensional numerical models of the subducting‐upper plates system. We find that the subduction of the buoyant continent results in the reduction of convergence velocity comparable to that observed in the Indian motions, yet the upper plate deformation remains accommodated in a narrow belt along a straight margin. Comparable rates are measured when the subducting slab breakoff is modeled, although the convergent margin deforms and curves markedly, with large underplating contiguous to ongoing subduction, similar to what observed along the Himalayan range. The models support the interpretation of the Himalayan Western Syntaxis evolution, the progressive curvature of the Indian margin and the underthrusting as a consequence of the Indian slab breakoff. The modeled slab detachment is followed by short‐lived large stresses in the upper plate interiors, propagating at large distance from the margin with a trend similar to several major Asian lithospheric faults. Such localized stress has likely provided the conditions for the formation of the Central Asian intracontinental faulting, the Bangong‐Red River and the Altyn Tagh faults, that followed successive Indian slab breakoff episodes. Continent subduction and breakoff during India‐Asia convergence offer an explanation for the different deformation mechanisms as the long‐lived understhrusting and the episodic lithospheric faulting in the Asian continent and their link to deep processes.
The effect of particle size on the rheology of liquid‐solid mixtures with application to lava flows: Results from analogue experiments
Authors: Del Gaudio P. , Ventura G. , Taddeucci J.
Published: May 2013

We investigate the effect of crystal size on the rheology of basaltic magmas by means of a rheometer and suspensions of silicon oil with natural magmatic crystals of variable size (from 63 to 0.5 mm) and volume fraction ϕ (from 0.03 to 0.6). At constant ϕ, finer suspensions display higher viscosities than coarser ones. Shear thinning (flow index n < 1) occurs at ϕ > 0.1–0.2 and is more pronounced (stronger departure from the Newtonian behavior) in finer suspensions. Maximum packing and average crystal size displays a nonlinear, positive correlation, while yield stress develops at ϕ > 0.2–0.3 irrespective of the crystal size. We incorporate our results into physical models for flow of lava and show that, with respect to lava flows containing coarser crystals, those with smaller crystals are expected to: 1) flow at lower velocity, 2) have a lower velocity gradient, and 3) be more prone to develop a region of plug flow. Our experimental results explain the observation that phenocryst‐bearing and microlite‐bearing lavas at Etna volcano (Italy) show smooth pahoehoe and rough aa' surfaces, respectively.
Close interactions between the Antarctic cyclone budget and large‐scale atmospheric circulation
Authors: Uotila Petteri , Vihma Timo , Tsukernik Maria
Published: May 2013

For the first time, we quantify relationships between the Southern Ocean cyclones and large‐scale atmospheric variability indices: the Southern Annular Mode (SAM), the El Niño–Southern Oscillation (ENSO), the Zonal Wave 3 (ZW3) pattern, and the semiannual oscillation (SAO). Using the ERA‐Interim 1979–2011 results, we identify cyclones south of 40°S and calculate monthly sectoral cyclone budgets of the Southern Ocean, defined as cyclogenesis minus cyclolysis plus net movement of cyclones into each sector. The SAM index has a strong connection with cyclones across all sectors. Positive SAM values are related to decreased eastward and increased southward movement of cyclones, resulting in higher cyclone densities along the Antarctic coast. The ENSO index shows strong associations with the cyclone behavior in the Amundsen‐Ross Seas, whereas other regions are less sensitive to it. The ZW3 index has a stronger association with the meridional movement of cyclones than other indices.
Low‐frequency earthquakes in the Mexican Sweet Spot
Authors: Frank William B. , Shapiro Nikolaï M. , Kostoglodov Vladimir , Husker Allen L. , Campillo Michel , Payero Juan S. , Prieto Germán A.
Published: May 2013

We use data from the Meso‐America Subduction Experiment to detect and locate low‐frequency earthquakes (LFEs) in the Mexican subduction zone. We use visually‐identified templates to perform a network waveform correlation search that produced ~17,000 robustly detected LFEs that form 15 distinct families. Stacking an LFE family's corresponding detections results in seismograms with high signal‐to‐noise ratios and clearPandSwave arrivals; we use these travel times to locate the sources. The resulting locations superpose a previously identified region of permanent non‐volcanic tremor (NVT) activity. Husker et al. (2012) called this region a Sweet Spot, suggesting that the local conditions are adequate to continuously generate NVT. The LFE hypocenters have been located at a depth of 40–45 km in an area that is surrounding the upper slab‐plate interface. We characterize their focal mechanisms by comparing their stacked seismograms to synthetic seismograms. This analysis reveals a common low‐dipping focal mechanism.
Nonfitting protein–ligand interaction scoring function based on first‐principles theoretical chemistry methods: Development and application on kinase inhibitors
Authors: Rao Li , Zhang Igor Ying , Guo Wenping , Feng Li , Meggers Eric , Xu Xin
Published: May 2013

Targeted therapy is currently a hot topic in the fields of cancer research and drug design. An important requirement for this approach is the development of potent and selective inhibitors for the identified target protein. However, current ways to estimate inhibitor efficacy rely on empirical protein–ligand interaction scoring functions which, suffering from their heavy parameterizations, often lead to a low accuracy. In this work, we develop a nonfitting scoring function, which consists of three terms: (1) gas‐phase protein‐ligand binding enthalpy obtained by the eXtended ONIOM hybrid method based on an integration of density functional theory (DFT) methods (XYG3 and ωB97X‐D) and the semiempirical PM6 method, (2) solvation free energy based on DFT‐SMD solvation model, and (3) entropy effect estimated by using DFT frequency analysis. The new scoring function is tested on a cyclin‐dependent kinase 2 (CDK2) inhibitor database including 76 CDK2 protein inhibitors and a p21‐activated kinase 1 (PAK1) inhibitor database including 20 organometallic PAK1 protein inhibitors. From the results, good correlations are found between the calculated scores and the experimental inhibitor efficacies with the square of correlation coefficient R2 of 0.76–0.88. This suggests a good predictive power of this scoring function. To the best of our knowledge, this is the first high level theory‐based nonfitting scoring function with such a good level of performance. This scoring function is recommended to be used in the final screening of lead structure derivatives. © 2013 Wiley Periodicals, Inc.
Biosynthesis of Highly Dispersed Palladium Nanoparticles Using Astraglmanna Aqueous Extract
Authors: Farhadi Khalil , Pourhossein Atefeh , Forough Mehrdad , Molaei Rahim , Abdi Ali , Siyami Abbas
Published: May 2013

Biosynthesis of nanoparticles has received increased attention due to a growing need to develop environmentally benign technologies in material synthesis and employment of secondary metabolites from plant extract that has emerged as a novel technology for this purpose. In this study, a rapid and biogenic process for fabrication of palladium nanoparticles (PdNPs) is reported. Highly dispersed palladium nanoparticles were successfully prepared by using aqueous extract of Astraglmanna, a non‐toxic and eco‐friendly material, without extra surfactant, capping agent, and template. The PdNPs were characterized by using UV—Visible spectroscopy, scanning electron microscope ‐ energy dispersive spectra (SEM‐EDX), Fourier transform infra red spectroscopy (FTIR), dynamic light scattering (DLS) and X‐ray diffraction (XRD) analysis. Transmission electron microscopic (TEM) images of the PdNPs were recorded and mean size of the biosynthesized nanoparticles was found to be approximately 15 nm.
Catalysis of Multi‐walled Carbon Nanotubes Supported PdxCoy Nanoparticles Prepared by a Pyrolysis Method Using Ionic Liquids as the Solvent toward Ethanol Oxidation Reaction
Authors: Yang Hongwei , Wang Yahui , Cao Yanli , Zheng Chunbao , Liu Lu , Liu Likun , Ding Keqiang , Rapole Sowjanya B. , Wang Yiran , Guo Zhanhu
Published: May 2013

Multi‐walled carbon nanotubes (MWCNTs) decorated with PdxCoy (the nominal atomic ratios of Pd to Co were 3:1, 3:1.5, 3:2, 3:3, respectively) nanoparticles (denoted as PdxCoy/MWCNTs ) were fabricated by a simple pyrolysis process, in which room temperature ionic liquids (RTILs) of butyl‐3‐methylimidazolium hexafluorophosphate (denoted as [BMIM]PF6) was used as the solvent. X‐ray diffraction (XRD) and transmission electron microscopy (TEM) were all used to characterize the PdxCoy/MWCNTs catalysts, showing that the PdxCoy particles were dispersed on the surface of the MWCNTs with an average particle size of ∼25.0 nm. The electro‐catalytic activity of the PdxCoy/MWCNTs catalysts toward ethanol oxidation reaction (EOR) was examined by cyclic voltammetry (CV). It was revealed that the onset potential was ∼90 mV lower and the peak current was about four times higher for ethanol oxidation for Pd3Co1.5/MWCNTs compared to those of Pd3Co1/MWCNTs. The possible catalysis mechanisms of the Pd3Co1.5/MWCNTs toward EOR were also discussed.
A Quantitative Analysis of the Spontaneous Reporting of Congestive Heart Failure‐Related Adverse Events With Systemic Anti‐Fungal Drugs
Authors: Hauben Manfred , Hung Eric Y.
Published: May 2013

To investigate spontaneous reporting relationships between representative antifungal agents and congestive heart failure (CHF)‐related adverse events (AE) we performed multiple disproportionality analyses of the US FDA AERS database. Specifically we performed analysis of drug‐AE associations (2D) plus drug–drug–AE and drug–AE–AE‐associations (3D), the latter two to explore the potential contribution of reported pharmacodynamic interactions, overexposure from pharmacokinetic interactions, and drug overdose. Itraconazole displayed a pattern of statistical reporting dependencies across multiple analyses (2D and 3D). Amphotericin B was the only other antifungal that demonstrated a 2D SDR with CHF‐related events. Itraconazole demonstrated multiple SDRs with calcium channel blockers in suspect drug‐only 3D analysis. There was one other SDR with fluconazole and propanolol and three SDRs involving valproate and fluconazole that may have been do at least in part to duplicate reporting. Less specific 3D analysis including both suspect plus concomitant medications showed a greater number and variety of SDRs with multiple antifungals. Statistical reporting dependencies with CHF‐related events did not appear to be a consistent pharmacological (e.g., azole/triazole)/therapeutic (i.e., antifungal) class effect. Itraconzole was unique in the pattern of statistical reporting dependencies with CHF‐related events which is consistent with findings from independent data sets.
Determinants and normal values of ascending aortic diameter by age, gender, and race/ethnicity in the Multi‐Ethnic Study of Atherosclerosis (MESA)
Authors: Turkbey Evrim B. , Jain Aditya , Johnson Craig , Redheuil Alban , Arai Andrew E. , Gomes Antoinette S. , Carr James , Hundley W. Gregory , Teixido‐Tura Gisela , Eng John , Lima João A.C. , Bluemke David A.
Published: May 2013

Purpose

To determine the normal size and wall thickness of the ascending thoracic aorta (AA) and its relationship with cardiovascular risk factors in a large population‐based study.

Materials and Methods

The mean AA luminal diameter was measured in 3573 Multi‐Ethnic Study of Atherosclerosis (MESA) participants (age: 45–84 years), using gradient echo phase contrast cine MRI. Multiple linear regression models were used to evaluate the associations between risk factors and AA diameter. The median and upper normal limit (95th percentile) was defined in a “healthy” subgroup as well as AA wall thickness.

Results

The upper limits of body surface area indexed AA luminal diameter for age categories of 45–54, 55–64, 65–74, and 75–84 years are 21, 22, 22, and 28 mm/m2 in women and 20, 21, 22, 23 mm/m2 in men, respectively. The mean AA wall thickness was 2.8 mm. Age, gender, and body surface area were major determinants of AA luminal diameter (∼+1 mm/10 years; ∼+1.9 mm in men than women; ∼+1 mm/ 0.23 m2; P < 0.001). The AA diameter in hypertensive subjects was +0.9 mm larger than in normotensives (P < 0.001).

Conclusion

AA diameter increases gradually with aging for both genders among all race/ethnicities. The normal value of AA diameter is provided. J. Magn. Reson. Imaging 2014;39:360–368. © 2013 Wiley Periodicals, Inc.