Stochastic models (cooperative and non-cooperative) for NMR analysis of the hetero-association of aromatic molecules in aqueous solution

International Nuclear Information System (INIS)

Evstigneev, Maxim P.; Davies, David B.; Veselkov, Alexei N.

2006-01-01

Stochastic cooperative (STOCH-C) and non-cooperative (STOCH-NC) models have been developed for NMR analysis of the hetero-association of aromatic compounds in solution, in order to take into account all physically meaningful association reactions of molecules in which there are no limitations on the lengths of the aggregates and complexes. These algorithmical approaches are compared with previously published basic (BASE) and generalized (GEN) analytical statistical thermodynamical models of hetero-association of biologically active aromatic molecules using the same sets of published NMR data measured under the same solution conditions (0.1 M phosphate buffer, pD = 7.1, T = 298 K). It is shown that, within experimental errors, the BASE analytical model may be used to describe molecular systems characterized by relatively small contributions of hetero-association reactions, whereas the GEN model may be applied to hetero-association reactions of any aromatic compound with different self-association properties. The STOCH-C computational algorithm enabled the effect on hetero-association of the interactions of molecules with different cooperativity parameters of self-association to be estimated for the first time and it is proposed that the algorithm for the stochastic models has great potential for detailed investigation and understanding of the interactions of aromatic molecules in solution

Effect of aromatic SAMs molecules on graphene/silicon schottky diode performance

OpenAIRE

Yağmurcukardeş, Nesli; Aydın, Hasan; Can, Mustafa; Yanılmaz, Alper; Mermer, Ömer; Okur, Salih; Selamet, Yusuf

2016-01-01

Au/n-Si/Graphene/Au Schottky diodes were fabricated by transferring atmospheric pressure chemical vapor deposited (APCVD) graphene on silicon substrates. Graphene/n-Si interface properties were improved by using 5-[(3-methylphenyl)(phenyl) amino]isophthalic acid (MePIFA) and 5-(diphenyl)amino]isophthalic acid (DPIFA) aromatic self-assembled monolayer (SAM) molecules. The surface morphologies of modified and non-modified films were investigated by atomic force microscopy and scanning electron ...

Profiles of equilibrium constants for self-association of aromatic molecules.

Science.gov (United States)

Beshnova, Daria A; Lantushenko, Anastasia O; Davies, David B; Evstigneev, Maxim P

2009-04-28

Analysis of the noncovalent, noncooperative self-association of identical aromatic molecules assumes that the equilibrium self-association constants are either independent of the number of molecules (the EK-model) or change progressively with increasing aggregation (the AK-model). The dependence of the self-association constant on the number of molecules in the aggregate (i.e., the profile of the equilibrium constant) was empirically derived in the AK-model but, in order to provide some physical understanding of the profile, it is proposed that the sources for attenuation of the equilibrium constant are the loss of translational and rotational degrees of freedom, the ordering of molecules in the aggregates and the electrostatic contribution (for charged units). Expressions are derived for the profiles of the equilibrium constants for both neutral and charged molecules. Although the EK-model has been widely used in the analysis of experimental data, it is shown in this work that the derived equilibrium constant, K(EK), depends on the concentration range used and hence, on the experimental method employed. The relationship has also been demonstrated between the equilibrium constant K(EK) and the real dimerization constant, K(D), which shows that the value of K(EK) is always lower than K(D).

Bio-Based Aromatic Epoxy Monomers for Thermoset Materials

Directory of Open Access Journals (Sweden)

Feifei Ng

2017-01-01

Full Text Available The synthesis of polymers from renewable resources is a burning issue that is actively investigated. Polyepoxide networks constitute a major class of thermosetting polymers and are extensively used as coatings, electronic materials, adhesives. Owing to their outstanding mechanical and electrical properties, chemical resistance, adhesion, and minimal shrinkage after curing, they are used in structural applications as well. Most of these thermosets are industrially manufactured from bisphenol A (BPA, a substance that was initially synthesized as a chemical estrogen. The awareness on BPA toxicity combined with the limited availability and volatile cost of fossil resources and the non-recyclability of thermosets implies necessary changes in the field of epoxy networks. Thus, substitution of BPA has witnessed an increasing number of studies both from the academic and industrial sides. This review proposes to give an overview of the reported aromatic multifunctional epoxide building blocks synthesized from biomass or from molecules that could be obtained from transformed biomass. After a reminder of the main glycidylation routes and mechanisms and the recent knowledge on BPA toxicity and legal issues, this review will provide a brief description of the main natural sources of aromatic molecules. The different epoxy prepolymers will then be organized from simple, mono-aromatic di-epoxy, to mono-aromatic poly-epoxy, to di-aromatic di-epoxy compounds, and finally to derivatives possessing numerous aromatic rings and epoxy groups.

Adsorption Characteristics of DNA Nucleobases, Aromatic Amino Acids and Heterocyclic Molecules on Silicene and Germanene Monolayers

KAUST Repository

Hussain, Tanveer

2017-09-14

Binding of DNA/RNA nucleobases, aromatic amino acids and heterocyclic molecules on two-dimensional silicene and germanene sheets have been investigated for the application of sensing of biomolecules using first principle density functional theory calculations. Binding energy range for nucleobases, amino acids and heterocyclic molecules with both the sheets have been found to be (0.43-1.16eV), (0.70-1.58eV) and (0.22-0.96eV) respectively, which along with the binding distances show that these molecules bind to both sheets by physisorption and chemisorption process. The exchange of electric charges between the monolayers and the incident molecules has been examined by means of Bader charge analysis. It has been observed that the introduction of DNA/RNA nucleobases, aromatic amino acids and heterocyclic molecules alters the electronic properties of both silicene and germanene nano sheets as studied by plotting the total (TDOS) and partial (PDOS) density of states. The DOS plots reveal the variation in the band gaps of both silicene and germanene caused by the introduction of studied molecules. Based on the obtained results we suggest that both silicene and germanene monolayers in their pristine form could be useful for sensing of biomolecules.

Aromatic C-nitrosation of a bioactive molecule. Nitrosation of minoxidil.

Science.gov (United States)

González-Jiménez, Mario; Arenas-Valgañón, Jorge; Calle, Emilio; Casado, Julio

2011-10-26

Minoxidil (2,4-diamino-6-(piperidin-1'-yl)pyrimidine N(3)-oxide; CASRN 38304-91-5) is a bioactive molecule with several nitrosatable groups widely used as an antihypertensive and antialopecia agent. Here the nitrosation of minoxidil was investigated. The conclusions drawn are as follows: (i) In the pH = 2.3-5.0 range, the minoxidil molecule undergoes aromatic C-nitrosation by nitrite. The dominant reaction was C-5 nitrosation through a mechanism that appears to consist of an electrophilic attack on the nitrosatable substrate by H(2)NO(2)(+)/NO(+), followed by a slow proton transfer; (ii) the reactivity of minoxidil as a C-nitrosatable substrate proved to be 7-fold greater than that of phenol, this being attributed to the preferred para- and ortho-orientations of the two -NH(2) groups at positions 2 and 4 of the minoxidil molecule, which activate electrophilic substitution in the C-5 position through their mesomeric effect. The N-nitrosominoxidil resulting from the nitrosation could be potentially harmful to the minoxidil users.

A MOLECULAR DYNAMICS STUDY ON SLOW ION INTERACTIONS WITH THE POLYCYCLIC AROMATIC HYDROCARBON MOLECULE ANTHRACENE

NARCIS (Netherlands)

Postma, J.; Hoekstra, Ronnie; Tielens, A. G. G. M.; Schlathölter, Thomas

2014-01-01

Atomic collisions with polycyclic aromatic hydrocarbon (PAH) molecules are astrophysically particularly relevant for collision energies of less than 1 keV. In this regime, the interaction dynamics are dominated by elastic interactions. We have employed a molecular dynamics simulation based on

Mini implants for definitive prosthodontic treatment: a systematic review.

Science.gov (United States)

Bidra, Avinash S; Almas, Khalid

2013-03-01

Mini implants are commonly used in orthodontics and for interim prosthodontic treatment, but evidence for their use in definitive prosthodontic treatment is not clear. This systematic review evaluated the mini-implant literature to analyze short-term (1 to 5 years), medium-term (5 to 10 years), and long-term (beyond 10 years) survival rates when used for definitive prosthodontic treatment. An electronic search of the English language literature for articles published between January 1974 and May 2012 was performed by using PubMed and Cochrane databases with predetermined inclusion criteria. Key terms included in the search were mini dental implants, narrow diameter implants, reduced diameter implants, small diameter implants, transitional implants, interim implants, and provisional implants. After a systematic filtering process, the selected articles were subjected to a detailed review, and the data collected were used to calculate the 1-year interval survival rate (ISR) and the cumulative survival rate (CSR). The electronic database search yielded 1807 titles. By scrutinizing the titles and abstracts with inclusion and exclusion criteria, the researchers identified 9 studies of mini implants for definitive prosthodontic treatment. Of the studies identified, 1 was a randomized controlled trial, 2 were prospective studies, and 6 were retrospective studies. The majority of mini implants were placed by using a flapless surgical technique in the mandibular anterior region to support an overdenture. The 1st year ISR was 94.7% and the CSR over a 9-year period, primarily attributed to data from 1 study, was 92.2%. Most implants were immediately loaded and almost all implant failures occurred during the first year after implant placement. For short-term survival, the first year ISR of 94.7% of mini dental implants appears encouraging, but the true 1-year survival rate is unknown, as the minimum follow-up period reported for several implants was less than a year

Adsorption Characteristics of DNA Nucleobases, Aromatic Amino Acids and Heterocyclic Molecules on Silicene and Germanene Monolayers

KAUST Repository

Hussain, Tanveer; Vovusha, Hakkim; Kaewmaraya, Thanayut; Amornkitbamrung, Vittaya; Ahuja, Rajeev

2017-01-01

Binding of DNA/RNA nucleobases, aromatic amino acids and heterocyclic molecules on two-dimensional silicene and germanene sheets have been investigated for the application of sensing of biomolecules using first principle density functional theory

DISSOCIATIVE PHOTOIONIZATION OF POLYCYCLIC AROMATIC HYDROCARBON MOLECULES CARRYING AN ETHYNYL GROUP

Energy Technology Data Exchange (ETDEWEB)

Rouillé, G.; Krasnokutski, S. A.; Fulvio, D.; Jäger, C. [Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, D-07743 Jena (Germany); Henning, Th. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Garcia, G. A.; Tang, X.-F.; Nahon, L., E-mail: cornelia.jaeger@uni-jena.de [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin BP 48, F-91192 Gif-sur-Yvette Cedex (France)

2015-09-10

The life cycle of the population of interstellar polycyclic aromatic hydrocarbon (PAH) molecules depends partly on the photostability of the individual species. We have studied the dissociative photoionization of two ethynyl-substituted PAH species, namely, 9-ethynylphenanthrene and 1-ethynylpyrene. Their adiabatic ionization energy and the appearance energy of fragment ions have been measured with the photoelectron photoion coincidence spectroscopy technique. The adiabatic ionization energy has been found at 7.84 ± 0.02 eV for 9-ethynylphenanthrene and at 7.41 ± 0.02 eV for 1-ethynylpyrene. These values are similar to those determined for the corresponding non-substituted PAH molecules phenanthrene and pyrene. The appearance energy of the fragment ion indicative of the loss of a H atom following photoionization is also similar for either ethynyl-substituted PAH molecule and its non-substituted counterpart. The measurements are used to estimate the critical energy for the loss of a H atom by the PAH cations and the stability of ethynyl-substituted PAH molecules upon photoionization. We conclude that these PAH derivatives are as photostable as the non-substituted species in H i regions. If present in the interstellar medium, they may play an important role in the growth of interstellar PAH molecules.

Support for designing waste sorting systems: A mini review.

Science.gov (United States)

Rousta, Kamran; Ordoñez, Isabel; Bolton, Kim; Dahlén, Lisa

2017-11-01

This article presents a mini review of research aimed at understanding material recovery from municipal solid waste. It focuses on two areas, waste sorting behaviour and collection systems, so that research on the link between these areas could be identified and evaluated. The main results presented and the methods used in the articles are categorised and appraised. The mini review reveals that most of the work that offered design guidelines for waste management systems was based on optimising technical aspects only. In contrast, most of the work that focused on user involvement did not consider developing the technical aspects of the system, but was limited to studies of user behaviour. The only clear consensus among the articles that link user involvement with the technical system is that convenient waste collection infrastructure is crucial for supporting source separation. This mini review reveals that even though the connection between sorting behaviour and technical infrastructure has been explored and described in some articles, there is still a gap when using this knowledge to design waste sorting systems. Future research in this field would benefit from being multidisciplinary and from using complementary methods, so that holistic solutions for material recirculation can be identified. It would be beneficial to actively involve users when developing sorting infrastructures, to be sure to provide a waste management system that will be properly used by them.

Parsing of the free energy of aromatic-aromatic stacking interactions in solution

Energy Technology Data Exchange (ETDEWEB)

Kostjukov, Viktor V.; Khomytova, Nina M. [Department of Physics, Sevastopol National Technical University, Sevastopol 99053, Crimea (Ukraine); Hernandez Santiago, Adrian A.; Tavera, Anna-Maria Cervantes; Alvarado, Julieta Salas [Faculty of Chemical Sciences, Autonomous University of Puebla, Puebla (Mexico); Evstigneev, Maxim P., E-mail: max_evstigneev@mail.ru [Department of Physics, Sevastopol National Technical University, Sevastopol 99053, Crimea (Ukraine)

2011-10-15

Graphical abstract: Highlights: > A protocol for decomposition of the free energy of aromatic stacking is developed. > The factors stabilizing/destabilizing stacking of aromatic molecules are defined. > Hydrophobic contribution is found to be dominant. - Abstract: We report an analysis of the energetics of aromatic-aromatic stacking interactions for 39 non-covalent reactions of self- and hetero-association of 12 aromatic molecules with different structures and charge states. A protocol for computation of the contributions to the total energy from various energetic terms has been developed and the results are consistent with experiment in 92% of all the systems studied. It is found that the contributions from hydrogen bonds and entropic factors are always unfavorable, whereas contributions from van-der-Waals, electrostatic and/or hydrophobic effects may lead to stabilizing or destabilizing factors depending on the system studied. The analysis carried out in this work provides an answer to the questions 'What forces stabilize/destabilize the stacking of aromatic molecules in aqueous-salt solution and what are their relative importance?'

Parsing of the free energy of aromatic-aromatic stacking interactions in solution

International Nuclear Information System (INIS)

Kostjukov, Viktor V.; Khomytova, Nina M.; Hernandez Santiago, Adrian A.; Tavera, Anna-Maria Cervantes; Alvarado, Julieta Salas; Evstigneev, Maxim P.

2011-01-01

Graphical abstract: Highlights: → A protocol for decomposition of the free energy of aromatic stacking is developed. → The factors stabilizing/destabilizing stacking of aromatic molecules are defined. → Hydrophobic contribution is found to be dominant. - Abstract: We report an analysis of the energetics of aromatic-aromatic stacking interactions for 39 non-covalent reactions of self- and hetero-association of 12 aromatic molecules with different structures and charge states. A protocol for computation of the contributions to the total energy from various energetic terms has been developed and the results are consistent with experiment in 92% of all the systems studied. It is found that the contributions from hydrogen bonds and entropic factors are always unfavorable, whereas contributions from van-der-Waals, electrostatic and/or hydrophobic effects may lead to stabilizing or destabilizing factors depending on the system studied. The analysis carried out in this work provides an answer to the questions 'What forces stabilize/destabilize the stacking of aromatic molecules in aqueous-salt solution and what are their relative importance?'

Targeting MicroRNA Function in Respiratory Diseases: Mini-review

Directory of Open Access Journals (Sweden)

Steven eMaltby

2016-02-01

Full Text Available MicroRNAs (miRNAs are small non-coding RNA molecules that modulate expression of the majority of genes by inhibiting protein translation. Growing literature has identified functional roles for miRNAs across a broad range of biological processes. As such, miRNAs are recognised as potential disease biomarkers and novel targets for therapies. While several miRNA-targeted therapies are currently in clinical trials (e.g. for the treatment of hepatitis C virus infection and cancer, no therapies have targeted miRNAs in respiratory diseases in the clinic. In this mini-review, we review the current knowledge on miRNA expression and function in respiratory diseases, intervention strategies to target miRNA function and considerations specific to respiratory diseases. Altered miRNA expression profiles have been reported in a number of respiratory diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis and idiopathic pulmonary fibrosis. These include alterations in isolated lung tissue, as well as sputum, bronchoalveolar lavage fluids and peripheral blood or serum. The observed alterations in easily accessible body fluids (e.g. serum have been proposed as new biomarkers that may inform disease diagnosis and patient management. In a subset of studies, miRNA-targeted interventions also improved disease outcomes, indicating functional roles for altered miRNA expression in disease pathogenesis. In fact, direct administration of miRNA-targeting molecules to the lung has yielded promising results in a number of animal models. The ability to directly administer compounds to the lung holds considerable promise and may limit potential off-target effects and side effects caused by the systemic administration required to treat other diseases.

Levan And Levansucrase-A Mini Review

Directory of Open Access Journals (Sweden)

Bruna Caroline Marques Goncalves

2015-05-01

Full Text Available Abstract Levansucrase is a fructosyltranferase that synthesizes levan and present great biotechnological interest. Its being widely used in therapeutic food cosmetic and pharmaceutical industries. Levansucrase is produced by many microorganisms such as the Bacillus subtilis Natto using the sucrose fermentation. In this mini-review we described some properties and functions of this important group of enzymes and the recent technologies used in the production and purification of levansucrase and levan.

A Review of Polycyclic Aromatic Hydrocarbons and Heavy Metal ...

African Journals Online (AJOL)

A Review of Polycyclic Aromatic Hydrocarbons and Heavy Metal Contamination of Fish from Fish Farms. ... Journal of Applied Sciences and Environmental Management ... Polycyclic aromatic hydrocarbons (PAHs) and heavy metals contribute to pollutants in aquaculture facilities and thus need to be further investigated.

1H NMR analysis of complexation of hydrotropic agents nicotinamide and caffeine with aromatic biologically active molecules in aqueous solution

Science.gov (United States)

Lantushenko, Anastasia O.; Mukhina, Yulia V.; Veselkov, Kyrill A.; Davies, David B.; Veselkov, Alexei N.

2004-07-01

NMR spectroscopy has been used to elucidate the molecular mechanism of solubilization action of hydrotropic agents nicotinamide (NA) and caffeine (CAF). Hetero-association of NA with riboflavine-mononucleotide (FMN) and CAF with low soluble in aqueous solution synthetic analogue of antibiotic actinomycin D, actinocyl-bis-(3-dimethylaminopropyl) amine (Actill), has been investigated by 500 MHz 1H NMR spectroscopy. Concentration and temperature dependences of proton chemical shifts have been analysed in terms of a statistical-thermodynamic model of indefinite self- and heteroassociation of aromatic molecules. The obtained results enable to conclude that NA-FMN and CAF-Actill intermolecular complexes are mainly stabilized by the stacking interactions of the aromatic chromophores. Hetero-association of the investigated molecules plays an important role in solubilization of aromatic drugs by hydrotropic agents nicotinamide and caffeine.

Absolute fragmentation cross sections in atom-molecule collisions: Scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules

Energy Technology Data Exchange (ETDEWEB)

Chen, T.; Gatchell, M.; Stockett, M. H.; Alexander, J. D.; Schmidt, H. T.; Cederquist, H.; Zettergren, H., E-mail: henning@fysik.su.se [Department of Physics, Stockholm University, S-106 91 Stockholm (Sweden); Zhang, Y. [Department of Mathematics, Faculty of Physics, M. V. Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Rousseau, P.; Maclot, S.; Delaunay, R.; Adoui, L. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen Cedex 05 (France); Université de Caen Basse-Normandie, Esplanade de la Paix, F-14032 Caen (France); Domaracka, A.; Huber, B. A. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen Cedex 05 (France); Schlathölter, T. [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands)

2014-06-14

We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH{sup +}) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections (including statistical fragmentation) for 110 eV PAH/PAH{sup +} + He collisions, and show that they compare well with experimental results. We demonstrate that non-statistical fragmentation becomes dominant for large PAHs and that it yields highly reactive fragments forming strong covalent bonds with atoms (H and N) and molecules (C{sub 6}H{sub 5}). Thus nonstatistical fragmentation may be an effective initial step in the formation of, e.g., Polycyclic Aromatic Nitrogen Heterocycles (PANHs). This relates to recent discussions on the evolution of PAHNs in space and the reactivities of defect graphene structures.

Self-consistent meta-generalized gradient approximation study of adsorption of aromatic molecules on noble metal surfaces

DEFF Research Database (Denmark)

Ferrighi, Lara; Madsen, Georg Kent Hellerup; Hammer, Bjørk

2011-01-01

aromatic molecules considered. The adsorption of pentacene is studied on Au, Ag, and Cu surfaces. In agreement with experiment, the adsorption energies are found to increase with decreasing nobleness, but the dependency is underestimated. We point out how the kinetic energy density can discriminate between...

Mini-Grids for the Base of the Pyramid Market: A Critical Review

Directory of Open Access Journals (Sweden)

Subhes C. Bhattacharyya

2018-04-01

Full Text Available The lack of access to electricity of more than 1.1 billion people around the world remains a major developmental challenge and Goal 7 of the Sustainable Development Goals (SDG as well as Sustainable Energy for All (SE4ALL have set a target of universal electrification by 2030. Various studies have identified mini-grid-based electrification as a possible solution. There is a growing body of literature available now that has explored the feasibility, practical application and policy interventions required to support mini-grids. Through a review of available literature, this paper explores whether mini-grids can be a solution for the base of the pyramid (BoP market and the challenges faced in deploying mini-grids in such markets. Interventions to support the mini-grid deployment are also discussed. The paper finds that the mini-grids are targeting the BoP market but the business is not attractive in profitability terms and requires financial support. Lack of regulatory clarity and non-coordinated policies affect the financial viability of projects, which requires careful support. Mini-grid electrification has hardly been embedded in rural development agenda and hence they have not contributed significantly to livelihood generation. Careful realignment of policies, regulatory frameworks and support systems can better support mini-grid deployment in developing countries.

Mini-implants in orthodontics: A systematic review of the literature

NARCIS (Netherlands)

Reynders, Reint; Ronchi, Laura; Bipat, Shandra

2009-01-01

Introduction: In this article, we systematically reviewed the literature to quantify success and complications encountered with the use of mini-implants for orthodontic anchorage, and to analyze factors associated with success or failure. Methods: Computerized and manual searches were conducted up

Simulation of angle-resolved photoemission spectra by approximating the final state by a plane wave: From graphene to polycyclic aromatic hydrocarbon molecules

Energy Technology Data Exchange (ETDEWEB)

Puschnig, Peter, E-mail: peter.puschnig@uni-graz.at; Lüftner, Daniel

2015-04-15

Highlights: • Computational study on angular dependent photoemission spectroscopy. • Graphene and polycyclic aromatic hydrocarbon molecules. • Plane wave final state approximation accounts for experimental findings. - Abstract: We present a computational study on the angular-resolved photoemission spectra (ARPES) from a number of polycyclic aromatic hydrocarbons and graphene. Our theoretical approach is based on ab-initio density functional theory and the one-step model where we greatly simplify the evaluation of the matrix element by assuming a plane wave for the final state. Before comparing our ARPES simulations with available experimental data, we discuss how typical approximations for the exchange-correlation energy affect orbital energies. In particular, we show that by employing a hybrid functional, considerable improvement can be obtained over semi-local functionals in terms of band widths and relative energies of π and σ states. Our ARPES simulations for graphene show that the plane wave final state approximation provides indeed an excellent description when compared to experimental band maps and constant binding energy maps. Furthermore, our ARPES simulations for a number of polycyclic aromatic molecules from the oligo-acene, oligo-phenylene, phen-anthrene families as well as for disc-shaped molecules nicely illustrate the evolution of the electronic structure from molecules with increasing size towards graphene.

From small aromatic molecules to functional nanostructured carbon by pulsed laser-induced photochemical stitching

Directory of Open Access Journals (Sweden)

R. R. Gokhale

2012-06-01

Full Text Available A novel route employing UV laser pulses (KrF Excimer, 248 nm to cleave small aromatic molecules and stitch the generated free radicals into functional nanostructured forms of carbon is introduced. The process differs distinctly from any strategies wherein the aromatic rings are broken in the primary process. It is demonstrated that this pulsed laser-induced photochemical stitching (PLPS process when applied to routine laboratory solvents (or toxic chemical wastes when discarded Chlorobenzene and o-Dichlorobenzene yields Carbon Nanospheres (CNSs comprising of graphene-like sheets assembled in onion-like configurations. This room temperature process implemented under normal laboratory conditions is versatile and clearly applicable to the whole family of haloaromatic compounds without and with additions of precursors or other nanomaterials. We further bring out its applicability for synthesis of metal-oxide based carbon nanocomposites.

Retardation the dewetting dynamics of ultrathin polystyrene films using highly branched aromatic molecules as additives

International Nuclear Information System (INIS)

Pangpaiboon, Nampueng; Traiphol, Nisanart; Promarak, Vinich; Traiphol, Rakchart

2013-01-01

This study introduces a new class of materials as a dewetting inhibitor for polystyrene (PS) ultrathin films. Two types of highly branched aromatic (HBA) molecules are added into PS films with thicknesses of 7 nm and 23 nm. Their concentrations range from 0.75 to 5 wt.%. The films are annealed in vacuum oven at elevated temperatures to accelerate dewetting process. Evolution of the film morphologies is followed by utilizing atomic force microscopy and optical microscopy. Contact angle measurements are used to evaluate interfacial interactions in each system. Dewetting area as a function of annealing time and HBA concentration are calculated. We have found that the presence of only 0.5 wt.% HBA can suppress the dewetting dynamics of PS films. Increasing the HBA concentration from 0.5 to 5 wt.% causes systematic decrease of the dewetting rate. In this system, the HBA molecules behave as physical cross-linking points for PS chains, which lead to the improvement of film stability. The efficiency of HBA as a dewetting inhibitor varies with molecular weight of PS while the change of HBA structure hardly affects the dewetting behaviors. - Highlights: • New method for improving stability of polystyrene (PS) thin films • Highly branched aromatic molecules (HBA) are used to suppress the dewetting. • Thermal stability of blended PS/HBA films greatly improves. • The effectiveness of HBA varies with molecular weight of PS. • Important results for designing materials in coating application

Retardation the dewetting dynamics of ultrathin polystyrene films using highly branched aromatic molecules as additives

Energy Technology Data Exchange (ETDEWEB)

Pangpaiboon, Nampueng [Research Unit of Advanced Ceramics, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Traiphol, Nisanart, E-mail: Nisanart.T@chula.ac.th [Research Unit of Advanced Ceramics, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Promarak, Vinich [School of Chemistry and Center of Excellence for Innovation in Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); Traiphol, Rakchart, E-mail: Rakchartt@nu.ac.th [Laboratory of Advanced Polymers and Nanomaterials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000 (Thailand); NANOTEC-MU Excellence Center on Intelligent Materials and Systems, Faculty of Science, Rama 6 Road, Ratchathewi, Bangkok 10400 (Thailand)

2013-12-02

This study introduces a new class of materials as a dewetting inhibitor for polystyrene (PS) ultrathin films. Two types of highly branched aromatic (HBA) molecules are added into PS films with thicknesses of 7 nm and 23 nm. Their concentrations range from 0.75 to 5 wt.%. The films are annealed in vacuum oven at elevated temperatures to accelerate dewetting process. Evolution of the film morphologies is followed by utilizing atomic force microscopy and optical microscopy. Contact angle measurements are used to evaluate interfacial interactions in each system. Dewetting area as a function of annealing time and HBA concentration are calculated. We have found that the presence of only 0.5 wt.% HBA can suppress the dewetting dynamics of PS films. Increasing the HBA concentration from 0.5 to 5 wt.% causes systematic decrease of the dewetting rate. In this system, the HBA molecules behave as physical cross-linking points for PS chains, which lead to the improvement of film stability. The efficiency of HBA as a dewetting inhibitor varies with molecular weight of PS while the change of HBA structure hardly affects the dewetting behaviors. - Highlights: • New method for improving stability of polystyrene (PS) thin films • Highly branched aromatic molecules (HBA) are used to suppress the dewetting. • Thermal stability of blended PS/HBA films greatly improves. • The effectiveness of HBA varies with molecular weight of PS. • Important results for designing materials in coating application.

Nonadiabatic Response Model of Laser-Induced Ultrafast π-Electron Rotations in Chiral Aromatic Molecules

International Nuclear Information System (INIS)

Kanno, Manabu; Kono, Hirohiko; Fujimura, Yuichi; Lin, Sheng H.

2010-01-01

We theoretically investigated the nonadiabatic couplings between optically induced π-electron rotations and molecular vibrations in a chiral aromatic molecule irradiated by a nonhelical, linearly polarized laser pulse. The results of wave packet dynamics simulation show that the vibrational amplitudes strongly depend on the initial rotation direction, clockwise or counterclockwise, which is controlled by the polarization direction of the incident pulse. This suggests that attosecond π-electron rotations can be observed by spectroscopic detection of femtosecond molecular vibrations.

Critical factors for the success of orthodontic mini-implants: a systematic review.

Science.gov (United States)

Chen, Yan; Kyung, Hee Moon; Zhao, Wen Ting; Yu, Won Jae

2009-03-01

This systematic review was undertaken to discuss factors that affect mini-implants as direct and indirect orthodontic anchorage. The data were collected from electronic databases (Medline [Entrez PubMed], Embase, Web of Science, Cochrane Library, and All Evidence Based Medicine Reviews). Randomized clinical trials, prospective and retrospective clinical studies, and clinical trials concerning the properties, affective factors, and requirements of mini-implants were considered. The titles and abstracts that appeared to fulfill the initial selection criteria were collected by consensus, and the original articles were retrieved and evaluated with a methodologic checklist. A hand search of key orthodontic journals was performed to identify recent unindexed literature. The search strategy resulted in 596 articles. By screening titles and abstracts, 126 articles were identified. After the exclusion criteria were applied, 16 articles remained. The analyzed results of the literature were divided into 2 topics: placement-related and loading-related factors. Mini-implants are effective as anchorage, and their success depends on proper initial mechanical stability and loading quality and quantity.

Recycling and management of waste lead-acid batteries: A mini-review.

Science.gov (United States)

Li, Malan; Liu, Junsheng; Han, Wei

2016-04-01

As a result of the wide application of lead-acid batteries to be the power supplies for vehicles, their demand has rapidly increased owing to their low cost and high availability. Accordingly, the amount of waste lead-acid batteries has increased to new levels; therefore, the pollution caused by the waste lead-acid batteries has also significantly increased. Because lead is toxic to the environment and to humans, recycling and management of waste lead-acid batteries has become a significant challenge and is capturing much public attention. Various innovations have been recently proposed to recycle lead and lead-containing compounds from waste lead-acid batteries. In this mini-review article, different recycling techniques for waste lead-acid batteries are highlighted. The present state of such recycling and its future perspectives are also discussed. We hope that this mini-review can provide useful information on recovery and recycling of lead from waste lead-acid batteries in the field of solid waste treatment. © The Author(s) 2016.

Noncomparative scaling of aromaticity through electron itinerancy

International Nuclear Information System (INIS)

Paul, Satadal; Goswami, Tamal; Misra, Anirban

2015-01-01

Aromaticity is a multidimensional concept and not a directly observable. These facts have always stood in the way of developing an appropriate theoretical framework for scaling of aromaticity. In the present work, a quantitative account of aromaticity is developed on the basis of cyclic delocalization of π-electrons, which is the phenomenon leading to unique features of aromatic molecules. The stabilization in molecular energy, caused by delocalization of π-electrons is obtained as a second order perturbation energy for archetypal aromatic systems. The final expression parameterizes the aromatic stabilization energy in terms of atom to atom charge transfer integral, onsite repulsion energy and the population of spin orbitals at each site in the delocalized π-electrons. An appropriate computational platform is framed to compute each and individual parameter in the derived equation. The numerical values of aromatic stabilization energies obtained for various aromatic molecules are found to be in close agreement with available theoretical and experimental reports. Thus the reliable estimate of aromaticity through the proposed formalism renders it as a useful tool for the direct assessment of aromaticity, which has been a long standing problem in chemistry

Electron Correlations and Two-Photon States in Polycyclic Aromatic Hydrocarbon Molecules: A Peculiar Role of Geometry

OpenAIRE

Aryanpour, K.; Shukla, A.; Mazumdar, S.

2013-01-01

We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene and circumcoronene, all possessing $D_{6h}$ point group symmetry versus ovalene with $D_{2h}$ symmetry, within the Pariser-Parr-Pople model of interacting $\\pi$-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitat...

Theoretical studies of the structures and local aromaticity of conjugated polycyclic hydrocarbons using three aromatic indices

Science.gov (United States)

Sakai, Shogo; Kita, Yuki

2013-07-01

The structures and local aromaticity of some conjugated polycyclic hydrocarbons (from the butadienoid, acene, and phenylene series) are studied using ab initio MO and density functional methods. The aromaticities of the molecules are estimated using three indices: the nucleus-independent chemical shift (NICS), the harmonic oscillator model of aromaticity (HOMA), and the index of deviation from aromaticity (IDA). Assessment of the relationships between the structures and the aromatic indices shows that the IDA values correspond best to the characteristics of the conjugated polycyclic hydrocarbon structures.

Adsorption of aromatic hydrocarbons and ozone at environmental aqueous surfaces.

Science.gov (United States)

Vácha, Robert; Cwiklik, Lukasz; Rezác, Jan; Hobza, Pavel; Jungwirth, Pavel; Valsaraj, Kalliat; Bahr, Stephan; Kempter, Volker

2008-06-05

Adsorption of environmentally important aromatic molecules on a water surface is studied by means of classical and ab initio molecular dynamics simulations and by reflection-absorption infrared spectroscopy. Both techniques show strong activity and orientational preference of these molecules at the surface. Benzene and naphthalene, which bind weakly to water surface with a significant contribution of dispersion interactions, prefer to lie flat on water but retain a large degree of orientational flexibility. Pyridine is more rigid at the surface. It is tilted with the nitrogen end having strong hydrogen bonding interactions with water molecules. The degree of adsorption and orientation of aromatic molecules on aqueous droplets has atmospheric implications for heterogeneous ozonolysis, for which the Langmuir-Hinshelwood kinetics mechanism is discussed. At higher coverages of aromatic molecules the incoming ozone almost does not come into contact with the underlying aqueous phase. This may rationalize the experimental insensitivity of the ozonolysis on the chemical nature of the substrate on which the aromatic molecules adsorb.

DMPD: Translational mini-review series on Toll-like receptors: networks regulated byToll-like receptors mediate innate and adaptive immunity. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 17223959 Translational mini-review series on Toll-like receptors: networks regulate...ol. 2007 Feb;147(2):199-207. (.png) (.svg) (.html) (.csml) Show Translational mini-review series on Toll-lik... immunity. PubmedID 17223959 Title Translational mini-review series on Toll-like receptors: networks regulat

Bacterial degradation of monocyclic aromatic amines

Directory of Open Access Journals (Sweden)

Pankaj Kumar Arora

2015-08-01

Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

Pulse gas chromatographic study of adsorption of substituted aromatics and heterocyclic molecules on MIL-47 at zero coverage.

Science.gov (United States)

Duerinck, Tim; Couck, Sarah; Vermoortele, Frederik; De Vos, Dirk E; Baron, Gino V; Denayer, Joeri F M

2012-10-02

The low coverage adsorptive properties of the MIL-47 metal organic framework toward aromatic and heterocyclic molecules are reported in this paper. The effect of molecular functionality and size on Henry adsorption constants and adsorption enthalpies of alkyl and heteroatom functionalized benzene derivates and heterocyclic molecules was studied using pulse gas chromatography. By means of statistical analysis, experimental data was analyzed and modeled using principal component analysis and partial least-squares regression. Structure-property relationships were established, revealing and confirming several trends. Among the molecular properties governing the adsorption process, vapor pressure, mean polarizability, and dipole moment play a determining role.

Analysis of Polycyclic Aromatic Hydrocarbons (PAHs in soils using ultrasonic agitation, heater/mini condenser tube and gaseous chromatography

Directory of Open Access Journals (Sweden)

Jurandir Pereira Pinto

2006-02-01

Full Text Available The increase in the number of gas stations in Brazil made it also possible the increase in the risk of underground waters contamination due to fuel spill. The polycyclic aromatic hydrocarbons (PAHs are petroleum-derived components and constitute a group of organic pollutants which are persistent in the environment and have highly carcinogenic capacity. In this work it was developed a PAHs analysis methodology in soils for quantifying these components, using the gaseous chromatography technique, through the optimization and validation of the chromatographic as well as the extraction, concentration and purification conditions of the PAHs. A good resolution for the sixteen PAHs was obtained, with retention times ranging from 6.1 to 43.7 minutes. The tube-heater/mini condenser system used for the solvent evaporation also showed satisfactory recovery for the naphthalene (83% as well as the extraction method by ultrasonic agitation with dichloromethane, obtaining recoveries that ranged from 74 to 104%. The analysis method proved to be appropriate for the quantification of the 16 PAHs in the evaluation of the environmental contamination in gas stations.

Intersystem crossing in complex molecules

International Nuclear Information System (INIS)

Pappalardo, R.G.

1980-01-01

The general question of singlet-triplet intersystem crossing is addressed in the context of large organic molecules, i.e., ''complex'' molecules capable of self-relaxation in the absence of collisions. Examples of spectral properties of such molecules in the vapor phase are discussed, relying on extensive Russian literature in this area. Formal expressions for the relaxation rate in the electronic excited states are derived on the basis of the formalism of collision theory, and are applied to the specific case of intersystem crossing. The derivation of the ''energy-gap'' law for triplet-singlet conversion in aromatic hydrocarbons is briefly outlined. The steep rise of internal conversion rates as a function of excess excitation energy, and its competition with the intersystem crossing process, are reviewed for the case of naphthalene vapor. A general expression for the spin-orbit interaction Hamiltonian in molecular systems is outlined. Experimental observations on singlet-triplet conversion rates and the factors that can drastically affect such rates are discussed, with emphasis on the ''in- ternal'' and ''external'' heavy-atom effects. Basic relations of ESR spectroscopy and magnetophotoselection are reviewed. Technological implications of the singlet-triplet crossing in complex molecules are discussed in the context of chelate lasers, dye lasers and luminescent displays. Effects related to singlet-triplet crossing, and generally to excited-state energy-transfer in biological systems, are exemplified by the role of aromatic amino-acids in the phosphorescence of proteins, by some recent studies of energy-transfer in models of biomembranes, and by the clustering of triplet-energy donor-acceptor pairs in micelles

Aromatic hydrocarbons

International Nuclear Information System (INIS)

Roder, M.

1985-01-01

Papers dealing with radiolysis of aromatic hydrocarbons of different composition (from benzene to terphenyls and hydrocarbons with condensed rings) as well as their mixtures (with alkanes, alkenes, other aromatic hydrocarbons) are reviewed. High radiation stability of aromatic hydrocarbons in condensed phases associated with peculiarities of molecular structure of compounds is underlined. Mechanisms of radiolytic processes, vaues of product yields are considered

DMPD: Translational mini-review series on Toll-like receptors: recent advances inunderstanding the role of Toll-like receptors in anti-viral immunity. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 17223961 Translational mini-review series on Toll-like receptors: recent advances i...147(2):217-26. (.png) (.svg) (.html) (.csml) Show Translational mini-review series on Toll-like receptors: r...nity. PubmedID 17223961 Title Translational mini-review series on Toll-like receptors: recent advances inund

Mass analyzed threshold ionization spectroscopy of aza-aromatic bicyclic molecules: Benzimidazole and benzotriazole

International Nuclear Information System (INIS)

Lin, J.L.; Li, Y.C.; Tzeng, W.B.

2007-01-01

We report the vibrationally resolved cation spectra of benzimidazole and benzotriazole, which give the respective adiabatic ionization energies (IEs) to be 67552 ± 5 cm -1 and 70474 ± 5 cm -1 . Comparing these data with that of indole, one finds that the IE of these aza-aromatic bicyclic molecules increases with the number of the N atoms. Most of the active modes of the benzimidazole cation are related to the in-plane ring vibrations. In contrast, the observed spectral bands of the benzotriazole cation correspond to the out-of-plane N2-H and skeleton N1N2N3 bending vibrations. These experimental findings may be attributed to the nature and the N atoms in the five-membered ring

Mini Review: Biomaterials for Enhancing Neuronal Repair

Science.gov (United States)

Cangellaris, Olivia V.; Gillette, Martha U.

2018-04-01

As they differentiate from neuroblasts, nascent neurons become highly polarized and elongate. Neurons extend and elaborate fine and fragile cellular extensions that form circuits enabling long-distance communication and signal integration within the body. While other organ systems are developing, projections of differentiating neurons find paths to distant targets. Subsequent post-developmental neuronal damage is catastrophic because the cues for reinnervation are no longer active. Advances in biomaterials are enabling fabrication of micro-environments that encourage neuronal regrowth and restoration of function by recreating these developmental cues. This mini-review considers new materials that employ topographical, chemical, electrical, and/or mechanical cues for use in neuronal repair. Manipulating and integrating these elements in different combinations will generate new technologies to enhance neural repair.

Spectroscopic Characterization of Key Aromatic Molecules: A Route toward The Origin of Life.

Science.gov (United States)

Puzzarini, Cristina; Baiardi, Alberto; Bloino, Julien; Barone, Vincenzo; Murphy, Thomas E; Drew, Dennis; Ali, Ashraf

2017-08-04

To gain information on the abiotic synthesis of the building blocks of life from simple molecules, and their subsequent chemical evolution to biological systems, the starting point is the identification of target species in Titan-like planets, i.e., planets that resemble the primitive Earth, as well as in Earth-like planets in the habitable zone of their star, namely planets where life can be already originated. In this scenario, molecular spectroscopy plays a crucial role because spectroscopic signatures are at the basis of an unequivocal proof for the presence of these target molecules. Thanks to the advances in many different techniques and to the NASA successful Kepler exoplanet transit mission, thousands of diverse planets outside of our solar system have been discovered. The James Webb Space Telescope (JWST), scheduled to be launched in 2018, will be very helpful in the identification of biosignature gases in Earth-like planets' atmospheres and of prebiotic molecule signatures in Titan-like atmospheres by observing their absorption during transits. While the search for key-target molecules in exoplanet atmospheres can be carried out by the JWST Transit Spectroscopy in the infrared (IR) region (0.6 - 29 µm wavelength range), opportunities for their detection in protostellar cores, protoplanetary disks and on Titan are also offered by the interferometric high spectral and spatial resolution observations using the Atacama Large Millimeter/submillimeter Array (ALMA). In the present work, target molecules have been selected and their spectroscopic characterization presented in view of supporting their infrared and complementary millimeter/submillimeter-wave spectral observations. In detail, the selected target molecules include: (1) the three-membered oxygen-containing heterocycles: oxirane and protonated oxirane, (2) the cyclopropenyl cation and its methyl derivative, (3) two examples of ortho- and peri-fused tri-cyclic aromatic rings, i.e., the phenalenyl

The status and developments of leather solid waste treatment: A mini-review.

Science.gov (United States)

Jiang, Huiyan; Liu, Junsheng; Han, Wei

2016-05-01

Leather making is one of the most widespread industries in the world. The production of leather goods generates different types of solid wastes and wastewater. These wastes will pollute the environment and threat the health of human beings if they are not well treated. Consequently, the treatment of pollution caused by the wastes from leather tanning is really important. In comparison with the disposal of leather wastewater, the treatment of leather solid wastes is more intractable. Hence, the treatment of leather solid wastes needs more innovations. To keep up with the rapid development of the modern leather industry, various innovative techniques have been newly developed. In this mini-review article, the major achievements in the treatment of leather solid wastes are highlighted. Emphasis will be placed on the treatment of chromium-tanned solid wastes; some new approaches are also discussed. We hope that this mini-review can provide some valuable information to promote the broad understanding and effective treatment of leather solid wastes in the leather industry. © The Author(s) 2016.

Biomechanics and load resistance of small-diameter and mini dental implants: a review of literature.

Science.gov (United States)

Hasan, Istabrak; Bourauel, Christoph; Mundt, Torsten; Stark, Helmut; Heinemann, Friedhelm

2014-02-01

In recent years, the application of small-diameter and mini dental implants to support removable and fixed prosthesis has dramatically increased. However, the success of these implants under functional biting forces and the reaction of the bone around them need to be analyzed. This review was aimed to present studies that deal with the fatigue life of small-diameter and mini dental implants under normal biting force, and their survival rate. The numerical and experimental studies concluded that an increase in the risk of bone damage or implant failure may be assumed in critical clinical situations and implants with <3 mm diameter have a risk of fracture in clinical practice. The survival rate of the small-diameter and mini dental implants over 5 years was 98.3-99.4%.

Mini-review: The Morphology, Mineralogy and Microbiology of Accumulated Iron Corrosion Products

Science.gov (United States)

2014-03-11

including the morphology, mineralogy , microbiology and the mecha- nisms for formation. Use of descriptive terms to denote specific iron corrosion product...RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) 11-03-2014 Journal Article Mini-review: the morphology, mineralogy and microbiology of...oxides/ hydroxides with a preponderance of α-FeOOH (goethite) and accumulation of metals. Bacteria, particularly iron-oxidizing and sulfatereducing

Radiation chemistry of aromatic dimer radical cations

International Nuclear Information System (INIS)

Okamoto, Kazumasa; Tagawa, Seiichi

2009-01-01

π-π Interactions of aromatic molecules are paid attention much in many fields, especially biology, chemistry, and applied physics, represented as protein, DNA, electron donor-accepter complexes, charge transfers, and self assembly molecules. Aromatic molecules including benzene rings are the simplest case to study the π-π interactions. To interpret the charge resonance (CR) structure in the dimer radical cations, spectroscopic and ESR methods have been carried out. The spectroscopic study on the dimer radical ion of molecules with two chromophores would be profitable to identify the electronic and configurational properties. In this article, dynamics of the dimer radical cation of benzenes, polystyrenes, and resist polymers is described on the basis of direct observation of CR band by the nanosecond pulse radiolysis and low temperature γ-radiolysis methods. (author)

Social media and college student risk behaviors: A mini-review.

Science.gov (United States)

Groth, Gabrielle G; Longo, Laura M; Martin, Jessica L

2017-02-01

Use of social media use is widespread and frequent among college students. Posting photos and text related to risk behaviors (e.g., problematic alcohol use, illicit drug use) on social media websites is common and has been linked to personal substance use and negative outcomes. This mini-review summarizes current findings related to associations between college students' social media use and engagement in risk behaviors. Conducting research on social media poses unique challenges for researchers; these challenges are reviewed and their impact on the state of the current literature discussed. Finally, implications for prevention and intervention efforts are discussed as well as recommendations regarding future research in the area of social media and college student risk behaviors. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effects of polycyclic aromatic hydrocarbons on the immune system of fish: A review

International Nuclear Information System (INIS)

Reynaud, S.; Deschaux, P.

2006-01-01

Polycyclic aromatic hydrocarbons are an important class of environmental pollutants that are known to be carcinogenic and immunotoxic. This review summarizes the diverse literature on the effects of these pollutants on innate and acquired immunity in fish and the mechanism of PAH-induced immunotoxicity. Among innate immune parameters, many authors have focused on macrophage activities in fish exposed to polycyclic aromatic hydrocarbons. Macrophage respiratory burst appears especially sensitive to polycyclic aromatic hydrocarbons. Among acquired immune parameters, lymphocyte proliferation appears highly sensitive to polycyclic aromatic hydrocarbon exposure. However, the effects of polycyclic aromatic hydrocarbons on both specific and non-specific immunity are contradictory and depend on the mode of exposure, the dose used or the species studied. In contrast to mammals, fewer studies have been done in fish to determine the mechanism of polycyclic aromatic hydrocarbon-induced toxicity. This phenomenon seems to implicate different intracellular mechanisms such as metabolism by cytochrome P4501A, binding to the Ah-receptor, or increased intracellular calcium. Advances in basic knowledge of fish immunity should lead to improvements in monitoring fish health and predicting the impact of polycyclic aromatic hydrocarbons on fish populations, which is a fundamental ecotoxicological goal

The effects of polycyclic aromatic hydrocarbons on the immune system of fish: A review

Energy Technology Data Exchange (ETDEWEB)

Reynaud, S. [Laboratoire d' Ecologie Alpine. UMR CNRS 5553. Universite Joseph Fourier. BP 53. 38041 Grenoble cedex 9 (France) and Laboratory of General and Comparative Immunophysiology, Science Teaching and Research Unit, 123, av. Albert Thomas, 87060 Limoges (France)]. E-mail: stephane.reynaud@ujf-grenoble.fr; Deschaux, P. [Laboratory of General and Comparative Immunophysiology, Science Teaching and Research Unit, 123, av. Albert Thomas, 87060 Limoges (France)

2006-05-01

Polycyclic aromatic hydrocarbons are an important class of environmental pollutants that are known to be carcinogenic and immunotoxic. This review summarizes the diverse literature on the effects of these pollutants on innate and acquired immunity in fish and the mechanism of PAH-induced immunotoxicity. Among innate immune parameters, many authors have focused on macrophage activities in fish exposed to polycyclic aromatic hydrocarbons. Macrophage respiratory burst appears especially sensitive to polycyclic aromatic hydrocarbons. Among acquired immune parameters, lymphocyte proliferation appears highly sensitive to polycyclic aromatic hydrocarbon exposure. However, the effects of polycyclic aromatic hydrocarbons on both specific and non-specific immunity are contradictory and depend on the mode of exposure, the dose used or the species studied. In contrast to mammals, fewer studies have been done in fish to determine the mechanism of polycyclic aromatic hydrocarbon-induced toxicity. This phenomenon seems to implicate different intracellular mechanisms such as metabolism by cytochrome P4501A, binding to the Ah-receptor, or increased intracellular calcium. Advances in basic knowledge of fish immunity should lead to improvements in monitoring fish health and predicting the impact of polycyclic aromatic hydrocarbons on fish populations, which is a fundamental ecotoxicological goal.

Factors Influencing Mini-CEX Rater Judgments and Their Practical Implications: A Systematic Literature Review.

Science.gov (United States)

Lee, Victor; Brain, Keira; Martin, Jenepher

2017-06-01

At present, little is known about how mini-clinical evaluation exercise (mini-CEX) raters translate their observations into judgments and ratings. The authors of this systematic literature review aim both to identify the factors influencing mini-CEX rater judgments in the medical education setting and to translate these findings into practical implications for clinician assessors. The authors searched for internal and external factors influencing mini-CEX rater judgments in the medical education setting from 1980 to 2015 using the Ovid MEDLINE, PsycINFO, ERIC, PubMed, and Scopus databases. They extracted the following information from each study: country of origin, educational level, study design and setting, type of observation, occurrence of rater training, provision of feedback to the trainee, research question, and identified factors influencing rater judgments. The authors also conducted a quality assessment for each study. Seventeen articles met the inclusion criteria. The authors identified both internal and external factors that influence mini-CEX rater judgments. They subcategorized the internal factors into intrinsic rater factors, judgment-making factors (conceptualization, interpretation, attention, and impressions), and scoring factors (scoring integration and domain differentiation). The current theories of rater-based judgment have not helped clinicians resolve the issues of rater idiosyncrasy, bias, gestalt, and conflicting contextual factors; therefore, the authors believe the most important solution is to increase the justification of rater judgments through the use of specific narrative and contextual comments, which are more informative for trainees. Finally, more real-world research is required to bridge the gap between the theory and practice of rater cognition.

The formation of quasi-alicyclic rings in alkyl-aromatic compounds

Science.gov (United States)

Straka, Pavel; Buryan, Petr; Bičáková, Olga

2018-02-01

The alkyl side chains of n-alkyl phenols, n-alkyl benzenes and n-alkyl naphthalenes are cyclised, as demonstrated by GC measurements, FTIR spectroscopy and molecular mechanics calculations. Cyclisation occurs due to the intramolecular interaction between an aromatic ring (-δ) and a hydrogen of the terminal methyl group (+δ) of an alkyl chain. In fact, conventional molecules are not aliphatic-aromatic, but quasi-alicyclic-aromatic. With the aromatic molecules formed with a quasi-alicyclic ring, the effect of van der Waals attractive forces increases not only intramolecularly but also intermolecularly. This effect is strong in molecules with propyl and higher alkyl substituents. The increase of intermolecular van der Waals attractive forces results in bi-linearity in the GC retention time of the compounds in question, observed in the dependence of the logarithm of the relative retention time on the number of carbons in a molecule in both polar and nonpolar stationary phases with both capillary and packed columns. The role of van der Waals forces has been demonstrated using the potential energies of covalent and noncovalent interactions for 2-n-alkyl phenols, n-alkyl benzenes and 1-n-alkyl- and 2-n-alkyl naphthalenes.

Polycyclic Aromatic Hydrocarbons: A Critical Review of Environmental Occurrence and Bioremediation.

Science.gov (United States)

Alegbeleye, Oluwadara Oluwaseun; Opeolu, Beatrice Oluwatoyin; Jackson, Vanessa Angela

2017-10-01

The degree of polycyclic aromatic hydrocarbon contamination of environmental matrices has increased over the last several years due to increase in industrial activities. Interest has surrounded the occurrence and distribution of polycyclic aromatic hydrocarbons for many decades because they pose a serious threat to the health of humans and ecosystems. The importance of the need for sustainable abatement strategies to alleviate contamination therefore cannot be overemphasised, as daily human activities continue to create pollution from polycyclic aromatic hydrocarbons and impact the natural environment. Globally, attempts have been made to design treatment schemes for the remediation and restoration of contaminated sites. Several techniques and technologies have been proposed and tested over time, the majority of which have significant limitations. This has necessitated research into environmentally friendly and cost-effective clean-up techniques. Bioremediation is an appealing option that has been extensively researched and adopted as it has been proven to be relatively cost-effective, environmentally friendly and is publicly accepted. In this review, the physicochemical properties of some priority polycyclic aromatic hydrocarbons, as well as the pathways and mechanisms through which they enter the soil, river systems, drinking water, groundwater and food are succinctly examined. Their effects on human health, other living organisms, the aquatic ecosystem, as well as soil microbiota are also elucidated. The persistence and bioavailability of polycyclic aromatic hydrocarbons are discussed as well, as they are important factors that influence the rate, efficiency and overall success of remediation. Bioremediation (aerobic and anaerobic), use of biosurfactants and bioreactors, as well as the roles of biofilms in the biological treatment of polycyclic aromatic hydrocarbons are also explored.

Polycyclic Aromatic Hydrocarbons: A Critical Review of Environmental Occurrence and Bioremediation

Science.gov (United States)

Alegbeleye, Oluwadara Oluwaseun; Opeolu, Beatrice Oluwatoyin; Jackson, Vanessa Angela

2017-10-01

The degree of polycyclic aromatic hydrocarbon contamination of environmental matrices has increased over the last several years due to increase in industrial activities. Interest has surrounded the occurrence and distribution of polycyclic aromatic hydrocarbons for many decades because they pose a serious threat to the health of humans and ecosystems. The importance of the need for sustainable abatement strategies to alleviate contamination therefore cannot be overemphasised, as daily human activities continue to create pollution from polycyclic aromatic hydrocarbons and impact the natural environment. Globally, attempts have been made to design treatment schemes for the remediation and restoration of contaminated sites. Several techniques and technologies have been proposed and tested over time, the majority of which have significant limitations. This has necessitated research into environmentally friendly and cost-effective clean-up techniques. Bioremediation is an appealing option that has been extensively researched and adopted as it has been proven to be relatively cost-effective, environmentally friendly and is publicly accepted. In this review, the physicochemical properties of some priority polycyclic aromatic hydrocarbons, as well as the pathways and mechanisms through which they enter the soil, river systems, drinking water, groundwater and food are succinctly examined. Their effects on human health, other living organisms, the aquatic ecosystem, as well as soil microbiota are also elucidated. The persistence and bioavailability of polycyclic aromatic hydrocarbons are discussed as well, as they are important factors that influence the rate, efficiency and overall success of remediation. Bioremediation (aerobic and anaerobic), use of biosurfactants and bioreactors, as well as the roles of biofilms in the biological treatment of polycyclic aromatic hydrocarbons are also explored.

Strong CH/O interactions between polycyclic aromatic hydrocarbons and water: Influence of aromatic system size.

Science.gov (United States)

Veljković, Dušan Ž

2018-03-01

Energies of CH/O interactions between water molecule and polycyclic aromatic hydrocarbons with a different number of aromatic rings were calculated using ab initio calculations at MP2/cc-PVTZ level. Results show that an additional aromatic ring in structure of polycyclic aromatic hydrocarbons significantly strengthens CH/O interactions. Calculated interaction energies in optimized structures of the most stable tetracene/water complex is -2.27 kcal/mol, anthracene/water is -2.13 kcal/mol and naphthalene/water is -1.97 kcal/mol. These interactions are stronger than CH/O contacts in benzene/water complex (-1.44 kcal/mol) while CH/O contacts in tetracene/water complex are even stronger than CH/O contacts in pyridine/water complexes (-2.21 kcal/mol). Electrostatic potential maps for different polycyclic aromatic hydrocarbons were calculated and used to explain trends in the energies of interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

Benzo-thia-fused [n]Thienoacenequinodimethanes with Small to Moderate Diradical Characters: The Role of Pro-aromaticity versus Anti-aromaticity

KAUST Repository

Shi, Xueliang

2016-01-19

Open-shell singlet diradicaloids recently have received much attention due to their unique optical, electronic and magnetic properties and promising applications in materials science. Among various diradicaloids, quinoidal π-conjugated molecules have become the prevailing designs. However, there still lacks fundamental understanding on how the fusion mode and pro-aromaticity/anti-aromaticity affect their diradical character and physical properties. In this work, a series of pro-aromatic benzo-thia-fused [n]thienoacenequinodimethanes (Thn-TIPS (n=1-3) and BDTh-TIPS) were synthesized and compared with the previously reported anti-aromatic bisindeno-[n]thienoacenes (Sn-TIPS, n=1-4). The ground-state geometric and electronic structures of these new quinoidal molecules were systematically investigated by X-ray crystallographic analysis, variable temperature NMR, ESR, SQUID, Raman, and electronic absorption spectroscopy, assisted by DFT calculations. It was found that the diradical character index (y0) increased from nearly zero for Th1-TIPS to 2.4% for Th2-TIPS, 18.2% for Th3-TIPS, and 38.2% for BDTh-TIPS, due to the enhanced aromatic stabilization. Consequently, with the extension of molecular size, the one-photon absorption spectra are gradually red-shifted, the two-photon absorption (TPA) cross section values increase, and the singlet excited state lifetimes decrease. By comparison with the corresponding anti-aromatic analogues Sn-TIPS (n=1-3), the pro-aromatic Thn-TIPS (n=1-3) exhibit larger diradical character, longer singlet excited state lifetime and larger TPA cross section value. At the same time, they display distinctively different electronic absorption spectra and improved electrochemical amphotericity. Spectroelectrochemical studies revealed a good linear relationship between the optical energy gaps and the molecular length in the neutral, radical cationic and dicationic forms. Our research work disclosed the significant difference between the pro-aromatic

Benzo-thia-fused [n]Thienoacenequinodimethanes with Small to Moderate Diradical Characters: The Role of Pro-aromaticity versus Anti-aromaticity

KAUST Repository

Shi, Xueliang; Quintero, EstefanÍ a; Lee, Sangsu; Jing, Linzhi; Herng, Tun Seng; Zheng, Bin; Huang, Kuo-Wei; Ló pez Navarrete, Juan T.; Ding, Jun; Kim, Dongho; Casado, Juan; Chi, Chunyan

2016-01-01

Open-shell singlet diradicaloids recently have received much attention due to their unique optical, electronic and magnetic properties and promising applications in materials science. Among various diradicaloids, quinoidal π-conjugated molecules have become the prevailing designs. However, there still lacks fundamental understanding on how the fusion mode and pro-aromaticity/anti-aromaticity affect their diradical character and physical properties. In this work, a series of pro-aromatic benzo-thia-fused [n]thienoacenequinodimethanes (Thn-TIPS (n=1-3) and BDTh-TIPS) were synthesized and compared with the previously reported anti-aromatic bisindeno-[n]thienoacenes (Sn-TIPS, n=1-4). The ground-state geometric and electronic structures of these new quinoidal molecules were systematically investigated by X-ray crystallographic analysis, variable temperature NMR, ESR, SQUID, Raman, and electronic absorption spectroscopy, assisted by DFT calculations. It was found that the diradical character index (y0) increased from nearly zero for Th1-TIPS to 2.4% for Th2-TIPS, 18.2% for Th3-TIPS, and 38.2% for BDTh-TIPS, due to the enhanced aromatic stabilization. Consequently, with the extension of molecular size, the one-photon absorption spectra are gradually red-shifted, the two-photon absorption (TPA) cross section values increase, and the singlet excited state lifetimes decrease. By comparison with the corresponding anti-aromatic analogues Sn-TIPS (n=1-3), the pro-aromatic Thn-TIPS (n=1-3) exhibit larger diradical character, longer singlet excited state lifetime and larger TPA cross section value. At the same time, they display distinctively different electronic absorption spectra and improved electrochemical amphotericity. Spectroelectrochemical studies revealed a good linear relationship between the optical energy gaps and the molecular length in the neutral, radical cationic and dicationic forms. Our research work disclosed the significant difference between the pro-aromatic

Aromaticity of benzene in condensed phases. A case of a benzene-water system

Science.gov (United States)

Zborowski, Krzysztof K.

2014-05-01

A theoretical Density Functional Theory study was performed for a benzene molecule in water cages. Two DFT functionals (B3LYP and BLYP) were employed. The optimized geometries of the studied clusters were used to calculate the aromaticity of benzene in a condensed phase using the aromaticity indices: HOMA, NICS, PDI, and H. The results were compared with aromaticity of a single benzene molecule in the gas phase and in the solvent environment provided by the PCM continuum model. It is argued that high aromaticity of benzene in the gas phase is retained in the water environment.

[Bone remodeling and modeling/mini-modeling.

Science.gov (United States)

Hasegawa, Tomoka; Amizuka, Norio

Modeling, adapting structures to loading by changing bone size and shapes, often takes place in bone of the fetal and developmental stages, while bone remodeling-replacement of old bone into new bone-is predominant in the adult stage. Modeling can be divided into macro-modeling(macroscopic modeling)and mini-modeling(microscopic modeling). In the cellular process of mini-modeling, unlike bone remodeling, bone lining cells, i.e., resting flattened osteoblasts covering bone surfaces will become active form of osteoblasts, and then, deposit new bone onto the old bone without mediating osteoclastic bone resorption. Among the drugs for osteoporotic treatment, eldecalcitol(a vitamin D3 analog)and teriparatide(human PTH[1-34])could show mini-modeling based bone formation. Histologically, mature, active form of osteoblasts are localized on the new bone induced by mini-modeling, however, only a few cell layer of preosteoblasts are formed over the newly-formed bone, and accordingly, few osteoclasts are present in the region of mini-modeling. In this review, histological characteristics of bone remodeling and modeling including mini-modeling will be introduced.

GAS-PHASE REACTIONS OF POLYCYCLIC AROMATIC HYDROCARBON ANIONS WITH MOLECULES OF INTERSTELLAR RELEVANCE

International Nuclear Information System (INIS)

Demarais, Nicholas J.; Yang Zhibo; Martinez, Oscar; Wehres, Nadine; Bierbaum, Veronica M.; Snow, Theodore P.

2012-01-01

We have studied reactions of small dehydrogenated polycyclic aromatic hydrocarbon anions with neutral species of interstellar relevance. Reaction rate constants are measured at 300 K for the reactions of phenide (C 6 H – 5 ), naphthalenide (C 10 H – 7 ), and anthracenide (C 14 H – 9 ) with atomic H, H 2 , and D 2 using a flowing afterglow-selected ion flow tube instrument. Reaction rate constants of phenide with neutral molecules (CO, O 2 , CO 2 , N 2 O, C 2 H 2 , CH 3 OH, CH 3 CN, (CH 3 ) 2 CO, CH 3 CHO, CH 3 Cl, and (CH 3 CH 2 ) 2 O) are also measured under the same conditions. Experimental measurements are accompanied by ab initio calculations to provide insight into reaction pathways and enthalpies. Our measured reaction rate constants should prove useful in the modeling of astrophysical environments, particularly when applied to dense regions of the interstellar and circumstellar medium.

Gas-phase Reactions of Polycyclic Aromatic Hydrocarbon Anions with Molecules of Interstellar Relevance

Science.gov (United States)

Demarais, Nicholas J.; Yang, Zhibo; Martinez, Oscar; Wehres, Nadine; Snow, Theodore P.; Bierbaum, Veronica M.

2012-02-01

We have studied reactions of small dehydrogenated polycyclic aromatic hydrocarbon anions with neutral species of interstellar relevance. Reaction rate constants are measured at 300 K for the reactions of phenide (C6H- 5), naphthalenide (C10H- 7), and anthracenide (C14H- 9) with atomic H, H2, and D2 using a flowing afterglow-selected ion flow tube instrument. Reaction rate constants of phenide with neutral molecules (CO, O2, CO2, N2O, C2H2, CH3OH, CH3CN, (CH3)2CO, CH3CHO, CH3Cl, and (CH3CH2)2O) are also measured under the same conditions. Experimental measurements are accompanied by ab initio calculations to provide insight into reaction pathways and enthalpies. Our measured reaction rate constants should prove useful in the modeling of astrophysical environments, particularly when applied to dense regions of the interstellar and circumstellar medium.

Refining MARGINS Mini-Lessons Using Classroom Observations

Science.gov (United States)

Iverson, E. A.; Manduca, C. A.; McDaris, J. R.; Lee, S.

2009-12-01

One of the challenges that we face in developing teaching materials or activities from research findings is testing the materials to determine that they work as intended. Traditionally faculty develop material for their own class, notice what worked and didn’t, and improve them the next year. However, as we move to a community process of creating and sharing teaching materials, a community-based process for testing materials is appropriate. The MARGINS project has piloted such a process for testing teaching materials and activities developed as part of its mini-lesson project (http://serc.carleton.edu/margins/index.html). Building on prior work developing mechanisms for community review of teaching resources (e.g. Kastens, 2002; Hancock and Manduca, 2005; Mayhew and Hall, 2007), the MARGINS evaluation team developed a structured classroom observation protocol. The goals of field testing are to a) gather structured, consistent feedback for the lesson authors based on classroom use; b) guide reviewers of these lessons to reflect on research-based educational practice as a framework for their comments; c) collect information on the data and observations that the reviewer used to underpin their review; d) determine which mini-lessons are ready to be made widely available on the website. The protocol guides faculty observations on why they used the activity, the effectiveness of the activity in their classroom, the success of the activity in leading to the desired learning, and what other faculty need to successfully use the activity. Available online (http://serc.carleton.edu/margins/protocol.html), the protocol can be downloaded and completed during instruction with the activity. In order to encourage review of mini-lessons using the protocol, a workshop focused on review and revision of activities was held in May 2009. In preparation for the workshop, 13 of the 28 participants chose to field test a mini-lesson prior to the workshop and reported that they found this

Hexacoordinate bonding and aromaticity in silicon phthalocyanine.

Science.gov (United States)

Yang, Yang

2010-12-23

Si-E bondings in hexacoordinate silicon phthalocyanine were analyzed using bond order (BO), energy partition, atoms in molecules (AIM), electron localization function (ELF), and localized orbital locator (LOL). Bond models were proposed to explain differences between hexacoordinate and tetracoordinate Si-E bondings. Aromaticity of silicon phthalocyanine was investigated using nucleus-independent chemical shift (NICS), harmonic oscillator model of aromaticity (HOMA), conceptual density functional theory (DFT), ring critical point (RCP) descriptors, and delocalization index (DI). Structure, energy, bonding, and aromaticity of tetracoordinate silicon phthalocyanine were studied and compared with hexacoordinate one.

Role of Conserved Disulfide Bridges and Aromatic Residues in Extracellular Loop 2 of Chemokine Receptor CCR8 for Chemokine and Small Molecule Binding

DEFF Research Database (Denmark)

Barington, Line; Rummel, Pia C; Lückmann, Michael

2016-01-01

and aromatic residues in extracellular loop 2 (ECL2) for ligand binding and activation in the chemokine receptor CCR8. We used IP3 accumulation and radioligand binding experiments to determine the impact of receptor mutagenesis on both chemokine and small molecule agonist and antagonist binding and action...... in CCR8. We find that the 7 transmembrane (7TM) receptor conserved disulfide bridge (7TM bridge) linking transmembrane helix (TM)III and ECL2 is crucial for chemokine and small molecule action, whereas the chemokine receptor conserved disulfide bridge between the N terminus and TMVII is needed only...

Prediction of druggable proteins using machine learning and systems biology: a mini-review

Directory of Open Access Journals (Sweden)

Gaurav eKandoi

2015-12-01

Full Text Available The emergence of -omics technologies has allowed the collection of vast amounts of data on biological systems. Although the pace of such collection has been exponential, the impact of these data remains small on many critical biomedical applications such as drug development. Limited resources, high costs and low hit-to-lead ratio have led researchers to search for more cost effective methodologies. A possible alternative is to incorporate computational methods of potential drug target prediction early during drug discovery workflow. Computational methods based on systems approaches have the advantage of taking into account the global properties of a molecule not limited to its sequence, structure or function. Machine learning techniques are powerful tools that can extract relevant information from massive and noisy data sets. In recent years the scientific community has explored the combined power of these fields to propose increasingly accurate and low cost methods to propose interesting drug targets. In this mini-review, we describe promising approaches based on the simultaneous use of systems biology and machine learning to access gene and protein druggability. Moreover, we discuss the state-of-the-art of this emerging and interdisciplinary field, discussing data sources, algorithms and the performance of the different methodologies. Finally, we indicate interesting avenues of research and some remaining open challenges.

Alexithymia and Suicide Risk in Psychiatric Disorders: A Mini-Review

Directory of Open Access Journals (Sweden)

Domenico De Berardis

2017-08-01

Full Text Available It is well known that alexithymic individuals may show significantly higher levels of anxiety, depression, and psychological suffering than non-alexithymics. There is an increasing evidence that alexithymia may be considered a risk factor for suicide, even simply increasing the risk of development of depressive symptoms or per se. Therefore, the purpose of this narrative mini-review was to elucidate a possible relationship between alexithymia and suicide risk. The majority of reviewed studies pointed out a relationship between alexithymia and an increased suicide risk. In several studies, this relationship was mediated by depressive symptoms. In conclusion, the importance of alexithymia screening in everyday clinical practice and the evaluation of clinical correlates of alexithymic traits should be integral parts of all disease management programs and, especially, of suicide prevention plans and interventions. However, limitations of studies are discussed and must be considered.

Alcohol consumption and prostate cancer: a mini review.

Science.gov (United States)

Rizos, Ch; Papassava, M; Golias, Ch; Charalabopoulos, K

2010-07-01

Prostate cancer has become a major public health problem worldwide although the etiology of prostate cancer remains largely unknown. Dietary factors, dietary supplements, and physical activity might be important in the prevention of the disease. In the majority of studies published, it was observed that high consumption of meat, alcohol and dairy products has been linked to a greater risk. Specifically, alcohol use, and particularly heavy use, may cause cancers of liver, esophagus, larynx, pharynx and oral cavity, with risks for the aero-digestive cancers. Moderate use among women has been related with increases in breast cancer. Alcohol consumption is a modifiable lifestyle factor that may affect prostate cancer risk. Alcohol alters the hormonal environment and in parallel, containing chemical substances such as flavonoids (red wine), may alter tumor cell growth. In this mini review, the relation between alcohol consumption and prostate cancer risk is analyzed.

Micropropagation of Ajuga species: a mini review.

Science.gov (United States)

Park, Han Yong; Kim, Doo Hwan; Sivanesan, Iyyakkannu

2017-09-01

The genus Ajuga L., belonging to Lamiaceae family, is widespread. The demand for Ajuga species has risen sharply because of their medicinal, ornamental, and pharmacological properties. These wide-ranging plants are being rapidly depleted due to over-collection for ornamental and medicinal purposes, as well as by habitat destruction and deforestation. Ajuga boninsimae, A. bracteosa, A. ciliate, A. genevensis, A. incisa, A. makinoi, A. multiflora, A. pyramidalis, A. shikotanensis, A. reptans, and A. vestita are categorized and protected as endangered plants. In vitro plant culture has therefore emerged for the conservation and mass clonal propagation of rare plants. This mini-review covers the current in vitro scenario in the propagation of Ajuga species. Adventitious or axillary shoots are initiated on the leaf, petiole and internodes, as well as roots, nodes, and shoot tip explants. Shoot induction is predominantly dependent on plant growth regulators added to the culture medium. Full- or half-strength Murashige and Skoog medium with or without auxin is used for in vitro rooting. Rooted shoots need to be acclimatized in the greenhouse with an estimated 82-100% survival rate.

A mini review on aflatoxin exposure in Malaysia: past, present and future

OpenAIRE

Mohd-Redzwan, Sabran; Jamaluddin, Rosita; Abd.-Mutalib, Mohd Sokhini; Ahmad, Zuraini

2013-01-01

This mini review article described the exposure of aflatoxin in Malaysia, including its presence in the foodstuffs and the detection of aflatoxin biomarkers in human biological samples. Historically, the exposure of aflatoxin in Malaysia can be dated in 1960s where an outbreak of disease in pig farms caused severe liver damage to the animals. Later, an aflatoxicosis case in Perak in 1988 was reported and caused death to 13 children, as up to 3 mg of aflatoxin was present in a single serving o...

Spectroscopic Diagnosis of Excited-State Aromaticity: Capturing Electronic Structures and Conformations upon Aromaticity Reversal.

Science.gov (United States)

Oh, Juwon; Sung, Young Mo; Hong, Yongseok; Kim, Dongho

2018-03-06

Aromaticity, the special energetic stability derived from cyclic [4 n + 2]π-conjugated electronic structures, has been the topic of intense interest in chemistry because it plays a critical role in rationalizing molecular stability, reactivity, and physical/chemical properties. Recently, the pioneering work by Colin Baird on aromaticity reversal, postulating that aromatic (antiaromatic) character in the ground state reverses to antiaromatic (aromatic) character in the lowest excited triplet state, has attracted much scientific attention. The completely reversed aromaticity in the excited state provides direct insight into understanding the photophysical/chemical properties of photoactive materials. In turn, the application of aromatic molecules to photoactive materials has led to numerous studies revealing this aromaticity reversal. However, most studies of excited-state aromaticity have been based on the theoretical point of view. The experimental evaluation of aromaticity in the excited state is still challenging and strenuous because the assessment of (anti)aromaticity with conventional magnetic, energetic, and geometric indices is difficult in the excited state, which practically restricts the extension and application of the concept of excited-state aromaticity. Time-resolved optical spectroscopies can provide a new and alternative avenue to evaluate excited-state aromaticity experimentally while observing changes in the molecular features in the excited states. Time-resolved optical spectroscopies take advantage of ultrafast laser pulses to achieve high time resolution, making them suitable for monitoring ultrafast changes in the excited states of molecular systems. This can provide valuable information for understanding the aromaticity reversal. This Account presents recent breakthroughs in the experimental assessment of excited-state aromaticity and the verification of aromaticity reversal with time-resolved optical spectroscopic measurements. To

Polycyclic Aromatic Hydrocarbons as Plausible Prebiotic Membrane Components

Science.gov (United States)

Groen, Joost; Deamer, David W.; Kros, Alexander; Ehrenfreund, Pascale

2012-08-01

Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C6-C10 fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane.

Aging and human sexual behavior: biocultural perspectives - a mini-review.

Science.gov (United States)

Gray, Peter B; Garcia, Justin R

2012-01-01

In this mini-review, we consider an evolutionary biocultural perspective on human aging and sexuality. An evolutionary approach to senescence highlights the energetic trade-offs between fertility and mortality. By comparing humans to other primates, we situate human senescence as an evolutionary process, with shifts in postreproductive sexual behavior in this light. Age-related declines in sexual behavior are typical for humans but also highly contingent on the sociocultural context within which aging individuals express their sexuality. We briefly review some of the most comprehensive studies of aging and sexual behavior, both from the USA and cross-culturally. We frame these patterns with respect to the long-term relationships within which human sexual behavior typically occurs. Because sexuality is typically expressed within pair-bonds, sexual behavior sometimes declines in both members of a couple with age, but also exhibits sex-specific effects that have their roots in evolved sex differences. Copyright © 2012 S. Karger AG, Basel.

Mini Tracheostomy for Obstructive Sleep Apnea: An Evidence Based Proposal

Science.gov (United States)

Camacho, Macario; Zaghi, Soroush; Chang, Edward T.; Song, Sungjin A.; Szelestey, Blake; Certal, Victor

2016-01-01

Objective. To search for articles evaluating the use of tracheostomies (either permanent stomas or tracheostomy tubes) in adult obstructive sleep apnea (OSA) patients and to evaluate the potential for the use of mini tracheostomies as treatment for OSA. Study Design. Systematic review. Methods. Nine databases were searched from inception through July 21, 2015. Results. The overall tracheostomy search yielded 516 articles, of which eighteen studies provided polysomnographic data. No study was identified (empty review) for the use of mini tracheostomies for treating OSA. The mini tracheostomy search yielded ninety-five articles which describe findings for either mini tracheostomy kits (inner cannula diameter of 4 mm) or the performance of mini tracheotomies. Six articles described the use of mini tracheostomies as a temporary procedure to relieve acute upper airway obstruction and none described the use for OSA. For tracheostomy stomal sites, suturing the skin directly to the tracheal rings with defatting can minimize stomal site collapse. The smallest tracheostomy stomal size that can successfully treat OSA has not been described. Conclusion. Mini tracheostomies as small as 4 mm have been successfully used in the short term to relieve upper airway obstruction. Given that polysomnography data are lacking, additional research is needed. PMID:26925105

Mini Tracheostomy for Obstructive Sleep Apnea: An Evidence Based Proposal

Directory of Open Access Journals (Sweden)

Macario Camacho

2016-01-01

Full Text Available Objective. To search for articles evaluating the use of tracheostomies (either permanent stomas or tracheostomy tubes in adult obstructive sleep apnea (OSA patients and to evaluate the potential for the use of mini tracheostomies as treatment for OSA. Study Design. Systematic review. Methods. Nine databases were searched from inception through July 21, 2015. Results. The overall tracheostomy search yielded 516 articles, of which eighteen studies provided polysomnographic data. No study was identified (empty review for the use of mini tracheostomies for treating OSA. The mini tracheostomy search yielded ninety-five articles which describe findings for either mini tracheostomy kits (inner cannula diameter of 4 mm or the performance of mini tracheotomies. Six articles described the use of mini tracheostomies as a temporary procedure to relieve acute upper airway obstruction and none described the use for OSA. For tracheostomy stomal sites, suturing the skin directly to the tracheal rings with defatting can minimize stomal site collapse. The smallest tracheostomy stomal size that can successfully treat OSA has not been described. Conclusion. Mini tracheostomies as small as 4 mm have been successfully used in the short term to relieve upper airway obstruction. Given that polysomnography data are lacking, additional research is needed.

Tuning dispersion correction in DFT-D2 for metal-molecule interactions: A tailored reparameterization strategy for the adsorption of aromatic systems on Ag(1 1 1)

Science.gov (United States)

Schiavo, Eduardo; Muñoz-García, Ana B.; Barone, Vincenzo; Vittadini, Andrea; Casarin, Maurizio; Forrer, Daniel; Pavone, Michele

2018-02-01

Common local and semi-local density functionals poorly describe the molecular physisorption on metal surfaces due to the lack of dispersion interactions. In the last decade, several correction schemes have been proposed to amend this fundamental flaw of Density Functional Theory. Using the prototypical case of aromatic molecules adsorbed on Ag(1 1 1), we discuss the accuracy of different dispersion-correction methods and present a reparameterization strategy for the simple and effective DFT-D2. For the adsorption of different aromatic systems on the same metallic substrate, good results at feasible computational costs are achieved by means of a fitting procedure against MP2 data.

AN AROMATIC INVENTORY OF THE LOCAL VOLUME

International Nuclear Information System (INIS)

Marble, A. R.; Engelbracht, C. W.; Block, M.; Van Zee, L.; Dale, D. A.; Cohen, S. A.; Schuster, M. D.; Smith, J. D. T.; Gordon, K. D.; Wu, Y.; Lee, J. C.; Kennicutt, R. C.; Skillman, E. D.; Johnson, L. C.; Calzetti, D.; Lee, H.

2010-01-01

Using infrared photometry from the Spitzer Space Telescope, we perform the first inventory of aromatic feature emission (also commonly referred to as polycyclic aromatic hydrocarbon emission) for a statistically complete sample of star-forming galaxies in the local volume. The photometric methodology involved is calibrated and demonstrated to recover the aromatic fraction of the Infrared Array Camera 8 μm flux with a standard deviation of 6% for a training set of 40 SINGS galaxies (ranging from stellar to dust dominated) with both suitable mid-infrared Spitzer Infrared Spectrograph spectra and equivalent photometry. A potential factor of 2 improvement could be realized with suitable 5.5 μm and 10 μm photometry, such as what may be provided in the future by the James Webb Space Telescope. The resulting technique is then applied to mid-infrared photometry for the 258 galaxies from the Local Volume Legacy (LVL) survey, a large sample dominated in number by low-luminosity dwarf galaxies for which obtaining comparable mid-infrared spectroscopy is not feasible. We find the total LVL luminosity due to five strong aromatic features in the 8 μm complex to be 2.47 x 10 10 L sun with a mean volume density of 8.8 x 10 6 L sun Mpc -3 . Twenty-four of the LVL galaxies, corresponding to a luminosity cut at M B = -18.22, account for 90% of the aromatic luminosity. Using oxygen abundances compiled from the literature for 129 of the 258 LVL galaxies, we find a correlation between metallicity and the aromatic-to-total infrared emission ratio but not the aromatic-to-total 8 μm dust emission ratio. A possible explanation is that metallicity plays a role in the abundance of aromatic molecules relative to the total dust content, but other factors, such as star formation and/or the local radiation field, affect the excitation of those molecules.

Bicyclic Baird-type aromaticity

Science.gov (United States)

Cha, Won-Young; Kim, Taeyeon; Ghosh, Arindam; Zhang, Zhan; Ke, Xian-Sheng; Ali, Rashid; Lynch, Vincent M.; Jung, Jieun; Kim, Woojae; Lee, Sangsu; Fukuzumi, Shunichi; Park, Jung Su; Sessler, Jonathan L.; Chandrashekar, Tavarekere K.; Kim, Dongho

2017-12-01

Classic formulations of aromaticity have long been associated with topologically planar conjugated macrocyclic systems. The theoretical possibility of so-called bicycloaromaticity was noted early on. However, it has yet to be demonstrated by experiment in a simple synthetic organic molecule. Conjugated organic systems are attractive for studying the effect of structure on electronic features. This is because, in principle, they can be modified readily through dedicated synthesis. As such, they can provide useful frameworks for testing by experiment with fundamental insights provided by theory. Here we detail the synthesis and characterization of two purely organic non-planar dithienothiophene-bridged [34]octaphyrins that permit access to two different aromatic forms as a function of the oxidation state. In their neutral forms, these congeneric systems contain competing 26 and 34 π-electronic circuits. When subject to two-electron oxidation, electronically mixed [4n+1]/[4n+1] triplet biradical species in the ground state are obtained that display global aromaticity in accord with Baird's rule.

Palladium-catalysed electrophilic aromatic C-H fluorination

Science.gov (United States)

Yamamoto, Kumiko; Li, Jiakun; Garber, Jeffrey A. O.; Rolfes, Julian D.; Boursalian, Gregory B.; Borghs, Jannik C.; Genicot, Christophe; Jacq, Jérôme; van Gastel, Maurice; Neese, Frank; Ritter, Tobias

2018-02-01

Aryl fluorides are widely used in the pharmaceutical and agrochemical industries, and recent advances have enabled their synthesis through the conversion of various functional groups. However, there is a lack of general methods for direct aromatic carbon-hydrogen (C-H) fluorination. Conventional methods require the use of either strong fluorinating reagents, which are often unselective and difficult to handle, such as elemental fluorine, or less reactive reagents that attack only the most activated arenes, which reduces the substrate scope. A method for the direct fluorination of aromatic C-H bonds could facilitate access to fluorinated derivatives of functional molecules that would otherwise be difficult to produce. For example, drug candidates with improved properties, such as increased metabolic stability or better blood-brain-barrier penetration, may become available. Here we describe an approach to catalysis and the resulting development of an undirected, palladium-catalysed method for aromatic C-H fluorination using mild electrophilic fluorinating reagents. The reaction involves a mode of catalysis that is unusual in aromatic C-H functionalization because no organometallic intermediate is formed; instead, a reactive transition-metal-fluoride electrophile is generated catalytically for the fluorination of arenes that do not otherwise react with mild fluorinating reagents. The scope and functional-group tolerance of this reaction could provide access to functional fluorinated molecules in pharmaceutical and agrochemical development that would otherwise not be readily accessible.

Influence of trace aromatics on the chemical growth mechanisms of Titan aerosol analogues

Science.gov (United States)

Gautier, Thomas; Sebree, Joshua A.; Li, Xiang; Pinnick, Veronica T.; Grubisic, Andrej; Loeffler, Mark J.; Getty, Stephanie A.; Trainer, Melissa G.; Brinckerhoff, William B.

2017-06-01

The chemical structure and formation pathways of Titan aerosols remain largely unknown. In this work, we studied the effect of trace aromatics on the chemical composition and formation pathways of laboratory analogues of Titan's organic aerosols. The aerosol analogues were produced using four different trace aromatic molecules, comprised of one or two aromatic rings, each with or without a nitrogen heteroatom. Samples were then analyzed by laser desorption/ionization Mass Spectrometry (LDMS), revealing a high variability in the sample composition depending on the trace aromatic used. Our work reveals that the final chemical structure of the aerosols depends strongly on the number of aromatic rings in the trace molecule, leading either to a polymeric or to a random co-polymeric growth of the sample. These different chemical structures can affect the physical properties of the aerosol. Future analysis of Titan's aerosols using better resolution could potentially determine whether either of the growth hypotheses are preferred.

UV irradiation of polycyclic aromatic hydrocarbons in ices: production of alcohols, quinones, and ethers

Science.gov (United States)

Bernstein, M. P.; Sandford, S. A.; Allamandola, L. J.; Gillette, J. S.; Clemett, S. J.; Zare, R. N.

1999-01-01

Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultraviolet (UV) radiation under astrophysical conditions, and the products were analyzed by infrared spectroscopy and mass spectrometry. Peripheral carbon atoms were oxidized, producing aromatic alcohols, ketones, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account for the interstellar 3.4-micrometer emission feature. These classes of compounds are all present in carbonaceous meteorites. Hydrogen and deuterium atoms exchange readily between the PAHs and the ice, which may explain the deuterium enrichments found in certain meteoritic molecules. This work has important implications for extraterrestrial organics in biogenesis.

Investigation on Single-Molecule Junctions Based on Current–Voltage Characteristics

Directory of Open Access Journals (Sweden)

Yuji Isshiki

2018-02-01

Full Text Available The relationship between the current through an electronic device and the voltage across its terminals is a current–voltage characteristic (I–V that determine basic device performance. Currently, I–V measurement on a single-molecule scale can be performed using break junction technique, where a single molecule junction can be prepared by trapping a single molecule into a nanogap between metal electrodes. The single-molecule I–Vs provide not only the device performance, but also reflect information on energy dispersion of the electronic state and the electron-molecular vibration coupling in the junction. This mini review focuses on recent representative studies on I–Vs of the single molecule junctions that cover investigation on the single-molecule diode property, the molecular vibration, and the electronic structure as a form of transmission probability, and electronic density of states, including the spin state of the single-molecule junctions. In addition, thermoelectronic measurements based on I–Vs and identification of the charged carriers (i.e., electrons or holes are presented. The analysis in the single-molecule I–Vs provides fundamental and essential information for a better understanding of the single-molecule science, and puts the single molecule junction to more practical use in molecular devices.

Bacterial Degradation of Aromatic Compounds

Directory of Open Access Journals (Sweden)

Qing X. Li

2009-01-01

Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

Mini-review: Prediction errors, attention and associative learning.

Science.gov (United States)

Holland, Peter C; Schiffino, Felipe L

2016-05-01

Most modern theories of associative learning emphasize a critical role for prediction error (PE, the difference between received and expected events). One class of theories, exemplified by the Rescorla-Wagner (1972) model, asserts that PE determines the effectiveness of the reinforcer or unconditioned stimulus (US): surprising reinforcers are more effective than expected ones. A second class, represented by the Pearce-Hall (1980) model, argues that PE determines the associability of conditioned stimuli (CSs), the rate at which they may enter into new learning: the surprising delivery or omission of a reinforcer enhances subsequent processing of the CSs that were present when PE was induced. In this mini-review we describe evidence, mostly from our laboratory, for PE-induced changes in the associability of both CSs and USs, and the brain systems involved in the coding, storage and retrieval of these altered associability values. This evidence favors a number of modifications to behavioral models of how PE influences event processing, and suggests the involvement of widespread brain systems in animals' responses to PE. Copyright © 2016 Elsevier Inc. All rights reserved.

MiniWall Tool for Analyzing CFD and Wind Tunnel Large Data Sets

Science.gov (United States)

Schuh, Michael J.; Melton, John E.; Stremel, Paul M.

2017-01-01

It is challenging to review and assimilate large data sets created by Computational Fluid Dynamics (CFD) simulations and wind tunnel tests. Over the past 10 years, NASA Ames Research Center has developed and refined a software tool dubbed the MiniWall to increase productivity in reviewing and understanding large CFD-generated data sets. Under the recent NASA ERA project, the application of the tool expanded to enable rapid comparison of experimental and computational data. The MiniWall software is browser based so that it runs on any computer or device that can display a web page. It can also be used remotely and securely by using web server software such as the Apache HTTP server. The MiniWall software has recently been rewritten and enhanced to make it even easier for analysts to review large data sets and extract knowledge and understanding from these data sets. This paper describes the MiniWall software and demonstrates how the different features are used to review and assimilate large data sets.

Epidemiology and vaccine of porcine epidemic diarrhea virus in China: a mini-review.

Science.gov (United States)

Sun, Dongbo; Wang, Xinyu; Wei, Shan; Chen, Jianfei; Feng, Li

2016-03-01

Porcine epidemic diarrhea (PED) is an intestinal infectious disease caused by porcine epidemic diarrhea virus (PEDV); manifestations of the disease are diarrhea, vomiting and dehydration. Starting from the end of 2010, a PED outbreak occurred in several pig-producing provinces in southern China. Subsequently, the disease spread throughout the country and caused enormous economic losses to the pork industry. Accumulating studies demonstrated that new PEDV variants that appeared in China were responsible for the PED outbreak. In the current mini-review, we summarize PEDV epidemiology and vaccination in China.

Metabolic activation of polycyclic and heterocyclic aromatic hydrocarbons and DNA damage: A review

International Nuclear Information System (INIS)

Xue Weiling; Warshawsky, David

2005-01-01

Polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic compounds (HACs) constitute a major class of chemical carcinogens present in the environment. These compounds require activation to electrophilic metabolites to exert their mutagenic or carcinogenic effects. There are three principal pathways currently proposed for metabolic activation of PAH and HAC: the pathway via bay region dihydrodiol epoxide by cytochrome P450 enzymes (CYPs), the pathway via radical cation by one-electron oxidation, and the ortho-quinone pathway by dihydrodiol dehydrogenase (DD). In addition to these major pathways, a brief description of a minor metabolic activation pathway, sulfonation, for PAHs that contain a primary benzylic alcoholic group or secondary hydroxyl group(s) is included in this review. The DNA damages caused through the reactive metabolites of PAH/HAC are described involving the DNA covalent binding to form stable or depurinating adducts, the formation of apurinic sites, and the oxidative damage. The review emphasizes the chemical/biochemical reactions involved in the metabolic processes and the chemical structures of metabolites and DNA adducts

Aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil: a review.

Science.gov (United States)

Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

2013-11-10

Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

Directory of Open Access Journals (Sweden)

Valerie Vranova

2013-01-01

Full Text Available Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

Science.gov (United States)

Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

2013-01-01

Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research. PMID:24319374

Dust and molecules in extra-galactic planetary nebulae

Science.gov (United States)

Garcia-Hernandez, Domingo Aníbal

2015-08-01

Extra-galactic planetary nebulae (PNe) permit the study of dust and molecules in metallicity environments other than the Galaxy. Their known distances lower the number of free parameters in the observations vs. models comparison, providing strong constraints on the gas-phase and solid-state astrochemistry models. Observations of PNe in the Galaxy and other Local Group galaxies such as the Magellanic Clouds (MC) provide evidence that metallicity affects the production of dust as well as the formation of complex organic molecules and inorganic solid-state compounds in their circumstellar envelopes. In particular, the lower metallicity MC environments seem to be less favorable to dust production and the frequency of carbonaceous dust features and complex fullerene molecules is generally higher with decreasing metallicity. Here, I present an observational review of the dust and molecular content in extra-galactic PNe as compared to their higher metallicity Galactic counterparts. A special attention is given to the level of dust processing and the formation of complex organic molecules (e.g., polycyclic aromatic hydrocarbons, fullerenes, and graphene precursors) depending on metallicity.

Three-dimensional aromatic networks.

Science.gov (United States)

Toyota, Shinji; Iwanaga, Tetsuo

2014-01-01

Three-dimensional (3D) networks consisting of aromatic units and linkers are reviewed from various aspects. To understand principles for the construction of such compounds, we generalize the roles of building units, the synthetic approaches, and the classification of networks. As fundamental compounds, cyclophanes with large aromatic units and aromatic macrocycles with linear acetylene linkers are highlighted in terms of transannular interactions between aromatic units, conformational preference, and resolution of chiral derivatives. Polycyclic cage compounds are constructed from building units by linkages via covalent bonds, metal-coordination bonds, or hydrogen bonds. Large cage networks often include a wide range of guest species in their cavity to afford novel inclusion compounds. Topological isomers consisting of two or more macrocycles are formed by cyclization of preorganized species. Some complicated topological networks are constructed by self-assembly of simple building units.

Fused aromatic thienopyrazines: structure, properties and function

KAUST Repository

Mondal, Rajib; Ko, Sangwon; Bao, Zhenan

2010-01-01

Recent development of a fused aromatic thieno[3.4-b]pyrazine system and their application in optoelectronic devices are reviewed. Introduction of a fused aromatic unit followed by side chain engineering, dramatically enhanced the charge carrier

Discovering Chemical Aromaticity Using Fragrant Plants

Science.gov (United States)

Schneider, Tanya L.

2010-01-01

Introductory organic chemistry is often perceived as inaccessible by students. This article describes a method used to link organic chemistry to everyday experience, asking students to explore whether fragrant molecules are also aromatic in the chemical sense. Students were engaged in this activity, excited about their results, and performed well…

Current status of waste management in Botswana: A mini-review.

Science.gov (United States)

Mmereki, Daniel

2018-05-01

Effective waste management practices are not all about legislative solutions, but a combination of the environmental, social, technical, technically skilled human resources, financial and technological resources, resource recycling, environmental pollution awareness programmes and public participation. As a result of insufficient resources, municipal solid waste (MSW) in transition and developing countries like Botswana remains a challenge, and it is often not yet given highest priority. In Botswana, the environment, public health and other socio-economic aspects are threatened by waste management practices due to inadequate implementation and enforcement mechanisms of waste management policy. This mini-review paper describes the panorama of waste management practices in Botswana and provides information to competent authorities responsible for waste management and to researchers to develop and implement an effective waste management system. Waste management practices in Botswana are affected by: lack of effective implementation of national waste policy, fragmented tasks and overlapping mandates among relevant institutions; lack of clear guidelines on the responsibilities of the generators and public authorities and on the associated economic incentives; and lack of consistent and comprehensive solid waste management policies; lack of intent by decision-makers to prepare national waste management plans and systems, and design and implement an integrated sustainable municipal solid waste management system. Due to these challenges, there are concerns over the growing trend of the illegal dumping of waste, creating mini dumping sites all over the country, and such actions jeopardize the efforts of lobbying investors and tourism business. Recommendations for concerted efforts are made to support decision makers to re-organize a sustainable waste management system, and this paper provides a reference to other emerging economies in the region and the world.

Novel Molecules Regulating Energy Homeostasis: Physiology and Regulation by Macronutrient Intake and Weight Loss

Directory of Open Access Journals (Sweden)

Anna Gavrieli

2016-09-01

Full Text Available Excess energy intake, without a compensatory increase of energy expenditure, leads to obesity. Several molecules are involved in energy homeostasis regulation and new ones are being discovered constantly. Appetite regulating hormones such as ghrelin, peptide tyrosine-tyrosine and amylin or incretins such as the gastric inhibitory polypeptide have been studied extensively while other molecules such as fibroblast growth factor 21, chemerin, irisin, secreted frizzle-related protein-4, total bile acids, and heme oxygenase-1 have been linked to energy homeostasis regulation more recently and the specific role of each one of them has not been fully elucidated. This mini review focuses on the above mentioned molecules and discusses them in relation to their regulation by the macronutrient composition of the diet as well as diet-induced weight loss.

Pharmacological Activities and Synthesis of Esculetin and Its Derivatives: A Mini-Review

Directory of Open Access Journals (Sweden)

Chengyuan Liang

2017-03-01

Full Text Available Esculetin, synonymous with 6,7-dihydroxycoumarin, is the main active ingredient of the traditional Chinese medicine Cortex Fraxini. The twig skin or trunk bark of Cortex Fraxini are used by herb doctors as a mild, bitter liver and gallbladder meridians’ nontoxic drug as well as dietary supplement. Recently, with a variety of novel esculetin derivatives being reported, the molecular mechanism research as well as clinical application of Cortex Fraxini and esculetin are becoming more attractive. This mini-review will consolidate what is known about the biological activities, the mechanism of esculetin and its synthetic derivatives over the past decade in addition to providing a brief synopsis of the properties of esculetin.

Co-Aromatization of Methane with Olefins: The Role of Inner Pore and External Surface Catalytic Sites

Energy Technology Data Exchange (ETDEWEB)

Yung, Matthew M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); He, Peng [University of Calgary; Jarvis, Jack [University of Calgary; Meng, Shijun [University of Calgary; Wang, Aiguo [University of Calgary; Kou, Shiyu [University of Calgary; Gatip, Richard [University of Calgary; Liu, Lijia [Soochow University; Song, Hua [University of Calgary

2018-04-22

The co-aromatization of methane with olefins is investigated using Ag-Ga/HZSM-5 as the catalyst at 400 degrees C. The presence of methane has a pronounced effect on the product distribution in terms of increased average carbon number and substitution index and decreased aromatic carbon fraction compared with its N2 environment counterpart. The participation of methane during the co-aromatization over the Ag-Ga/HZSM-5 catalyst diminishes as the co-fed olefin feedstock molecule becomes larger, from 1-hexene to 1-octene and 1-decene, in diameter. The effect of suppressed methane participation with larger olefinic molecules is not as significant when Ag-Ga/HY is employed as the catalyst, which might be attributed to the larger pore size of HY that gives more room to hold olefin and methane molecules within the inner pores and reduces the diffusion limitation of olefin molecules. The effect of olefin feedstock on the methane participation during the co-aromatization over Ag-Ga/HZSM-5 is experimentally evidenced by 13C and 2D NMR. The incorporation of the methane carbon atoms into the phenyl ring of product molecules is reduced significantly with larger co-fed olefins, whereas its incorporation into the substitution groups of the formed aromatic molecules is not notably affected, suggesting that the methane participation in the phenyl ring formation might preferably occur within inner pores, while its incorporation into substitution groups may mainly take place on external catalytic sites. This hypothesis is well supported by the product selectivity obtained over Ag-Ga/HZSM-5 catalysts prepared using conventional ZSM-5, ZSM-5 with the external catalytic sites deactivated, nanosize ZSM-5, ZSM-5 with a micro/meso pore structure and ZSM-5 with the inner pores blocked, and further confirmed by the isotopic labeling studies.

The mutagenic potential of high flash aromatic naphtha.

Science.gov (United States)

Schreiner, C A; Edwards, D A; McKee, R H; Swanson, M; Wong, Z A; Schmitt, S; Beatty, P

1989-06-01

Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent--high-flash aromatic naphtha. A program was initiated to assess the toxicological properties of high-flash aromatic naphtha since there may be human exposure through inhalation or external body contact. The current study was conducted partly to assess the potential for mutagenic activity and also to assist in an assessment of carcinogenic potential. The specific tests utilized included the Salmonella/mammalian microsome mutagenicity assay, the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) forward mutation assay in CHO cells, in vitro chromosome aberration and sister chromatid exchange (SCE) assays in CHO cells, and an in vivo chromosome aberration assay in rat bone marrow.

Recommended safety objectives, principles and requirements for mini-reactors

International Nuclear Information System (INIS)

1991-05-01

Canadian and international publications containing objectives, principles and requirements for the safety of nuclear facilities in general and nuclear power plants in particular have been reviewed for their relevance to mini-reactors. Most of the individual recommendations, sometimes with minor wording changes, are applicable to mini-reactors. However, some prescriptive requirements for the shutdown, emergency core cooling and containment systems of power reactors are considered inappropriate for mini-reactors. The Advisory Committee on Nuclear Safety favours a generally non-prescriptive approach whereby the applicant for a mini-reactor license is free to propose any means of satisfying the fundamental objectives, but must convince the regulatory agency to that effect. To do so, a probabilistic safety assessment (PSA) would be the favoured procedure. A generic PSA for all mini-reactors of the same design would be acceptable. Notwithstanding this non-prescriptive approach, the ACNS considers that it would be prudent to require the existence of at least one independent shutdown system and two physically independent locations from which the reactor can be shut down and the shutdown condition monitored, and to require provision for an assumed loss of integrity of the primary cooling system's boundary unless convincing arguments to the contrary are presented. The ACNS endorses in general the objectives and fundamental principles proposed by the interorganizational Small Reactor Criteria working group, and intends to review and comment on the documents on specific applications to be issued by that working group

Challenges and opportunities of biodegradable plastics: A mini review.

Science.gov (United States)

Rujnić-Sokele, Maja; Pilipović, Ana

2017-02-01

The concept of materials coming from nature with environmental advantages of being biodegradable and/or biobased (often referred to as bioplastics) is very attractive to the industry and to the consumers. Bioplastics already play an important role in the fields of packaging, agriculture, gastronomy, consumer electronics and automotive, but still they have a very low share in the total production of plastics (currently about 1% of the about 300 million tonnes of plastic produced annually). Biodegradable plastics are often perceived as the possible solution for the waste problem, but biodegradability is just an additional feature of the material to be exploited at the end of its life in specific terms, in the specific disposal environment and in a specific time, which is often forgotten. They should be used as a favoured choice for the applications that demand a cheap way to dispose of the item after it has fulfilled its job (e.g. for food packaging, agriculture or medical products). The mini-review presents the opportunities and future challenges of biodegradable plastics, regarding processing, properties and waste management options.

Solvation of carbonaceous molecules by para-H{sub 2} and ortho-D{sub 2} clusters. I. Polycyclic aromatic hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Calvo, F., E-mail: florent.calvo@univ-grenoble-alpes.fr [Univ. Grenoble Alpes, LIPHY, F-38000 Grenoble, France and CNRS, LIPHY, F-38000 Grenoble (France); Yurtsever, E. [Koç University, Rumelifeneriyolu, Sariyer, Istanbul 34450 (Turkey)

2016-06-14

This work theoretically examines the progressive coating of planar polycyclic aromatic hydrocarbon (PAH) molecules ranging from benzene to circumcoronene (C{sub 54}H{sub 18}) by para-hydrogen and ortho-deuterium. The coarse-grained Silvera-Goldman potential has been extended to model the interactions between hydrogen molecules and individual atoms of the PAH and parametrized against quantum chemical calculations for benzene-H{sub 2}. Path-integral molecular dynamics simulations at 2 K were performed for increasingly large amounts of hydrogen coating the PAH up to the first solvation shell and beyond. From the simulations, various properties were determined such as the size of the first shell and its thickness as well as the solvation energy. The degree of delocalization was notably quantified from an energy landscape perspective, by monitoring the fluctuations among inherent structures sampled by the trajectories. Our results generally demonstrate a high degree of localization owing to relatively strong interactions between hydrogen and the PAH, and qualitatively minor isotopic effects. In the limit of large hydrogen amounts, the shell size and solvation energy both follow approximate linear relations with the numbers of carbon and hydrogen in the PAH.

Microbial diversity in Brazilian mangrove sediments – a mini review

Science.gov (United States)

Ghizelini, Angela Michelato; Mendonça-Hagler, Leda Cristina Santana; Macrae, Andrew

2012-01-01

The importance and protection of mangrove ecosystems has been recognized in Brazilian Federal law since 1965. Being protected in law, however, has not always guaranteed their protection in practice. Mangroves are found in coastal and estuarine locations, which are prime real estate for the growth of cities, ports and other economic activities important for Brazilian development. In this mini-review we introduce what mangroves are and why they are so important. We give a brief overview of the microbial diversity found in mangrove sediments and then focus on diversity studies from Brazilian mangroves. We highlight the breadth and depth of knowledge about mangrove microbial communities gained from studying Brazilian mangroves. We report on the exciting findings of molecular microbial ecology methods that have been very successfully applied to study bacterial communities. We note that there have been fewer studies that focus on fungal communities and that fungal diversity studies deserve more attention. The review ends with a look at how a combination of new molecular biology methods and isolation studies are being developed to monitor and conserve mangrove ecosystems and their associated microbial communities. These recent studies are having a global impact and we hope they will help to protect and re-establish mangrove ecosystems. PMID:24031949

The BaBar Mini

International Nuclear Information System (INIS)

Brown, David N.

2003-01-01

BaBar has recently deployed a new event data format referred to as the Mini. The mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per event. The Mini currently uses Objectivity persistence, and it is being ported to use Root persistence. The Mini contains enough information to support detailed detector studies, while remaining small and fast enough to be used directly in physics analysis. Mini output is customizable, allowing users to both truncate unnecessary content or add content, depending on their needs. The Mini has now replaced three older formats as the primary output of BaBar event reconstruction. A reduced form of the Mini will soon replace the physics analysis format as well, giving BaBar a single, flexible event data format covering all its needs

The BaBar mini

International Nuclear Information System (INIS)

Brown, David N.; BaBar Collaboration

2003-01-01

BaBar has recently deployed a new event data format referred to as the Mini. The mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per event. The Mini currently uses Objectivity persistence, and it is being ported to use Root persistence. The Mini contains enough information to support detailed detector studies, while remaining small and fast enough to be used directly in physics analysis. Mini output is customizable, allowing users to both truncate unnecessary content or add content, depending on their needs. The Mini has now replaced three older formats as the primary output of BaBar event reconstruction. A reduced form of the Mini will soon replace the physics analysis format as well, giving BaBar a single, flexible event data format covering all its needs

Role of Dehalogenases in Aerobic Bacterial Degradation of Chlorinated Aromatic Compounds

Directory of Open Access Journals (Sweden)

Pankaj Kumar Arora

2014-01-01

Full Text Available This review was conducted to provide an overview of dehalogenases involved in aerobic biodegradation of chlorinated aromatic compounds. Additionally, biochemical and molecular characterization of hydrolytic, reductive, and oxygenolytic dehalogenases was reviewed. This review will increase our understanding of the process of dehalogenation of chlorinated aromatic compounds.

Use of bovine catalase and manganese dioxide for elimination of hydrogen peroxide from partly oxidized aqueous solutions of aromatic molecules - Unexpected complications

Science.gov (United States)

Kovács, Krisztina; Sági, Gyuri; Takács, Erzsébet; Wojnárovits, László

2017-10-01

Being a toxic substance, hydrogen peroxide (H2O2) formed during application of advanced oxidation processes disturbs the biological assessment of the treated solutions. Therefore, its removal is necessary when the concentration exceeds the critical level relevant to the biological tests. In this study, H2O2 removal was tested using catalase enzyme or MnO2 as catalysts and the concentration changes were measured by the Cu(II)/phenanthroline method. MnO2 and Cu(II) were found to react not only with H2O2 but also with the partly oxidized intermediates formed in the hydroxyl radical induced degradation of aromatic antibiotic and pesticide compounds. Catalase proved to be a milder oxidant, it did not show significant effects on the composition of organic molecules. The Cu(II)/phenanthroline method gives the correct H2O2 concentration only in the absence of easily oxidizable compounds, e.g. certain phenol type molecules.

Diagnosis of the σ-, π- and (σ+π-Aromaticity by the Shape of the NICSzz-Scan Curves and Symmetry-Based Selection Rules

Directory of Open Access Journals (Sweden)

Constantinos A. Tsipis

2010-03-01

Full Text Available The NICSzz-scan curves of aromatic organic, inorganic and “all-metal” molecules in conjunction with symmetry-based selection rules provide efficient diagnostic tools of the σ-, π- and/or double (σ + π-aromaticity. The NICSzz-scan curves of σ-aromatic molecules are symmetric around the z-axis, having half-band widths approximately less than 3 Å with the induced diatropic ring current arising from Tx,y-allowed transitions involving exclusively σ-type molecular orbitals. Broad NICSzz-scan curves (half-band width approximately higher than 3 Å characterize double (σ + π-aromaticity, the chief contribution to the induced diatropic ring current arising from Tx,y-allowed transitions involving both σ- and π-type molecular orbitals. NICSzz-scan curves exhibiting two maxima at a certain distance above and below the molecular plane are typical for (σ + π-aromatics where the π-diatropic ring current overwhelms the σ-type one. In the absence of any contribution from the σ-diatropic ring current, the NICSzz(0 value is close to zero and the molecule exhibits pure π-aromaticity.

Polycyclic aromatic hydrocarbons in stellar medium

Science.gov (United States)

Rastogi, Shantanu

2005-06-01

Polycyclic Aromatic Hydrocarbons (PAHs) are an important com- ponent of the Interstellar Medium (ISM). They are being used as probes for understanding of process and conditions of different astrophysical environments. The understanding of their IR spectra and its variations with PAH size and ionization state is useful in characterizing the ISM. Spectral features of model graphene sheets and also that of smaller PAH molecules are reported. The variation of intensity with charge state of the molecule shows that cations give a better correlation with observations. The relationship between changes in charge distribution with intensity changes upon ionization has been probed.

Development of a Relative Potency Factor (Rpf) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (External Review Draft)

Science.gov (United States)

EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of polycyclic aromatic hydrocarbon (PAH) mixtures that when finalized will appear on the Integrated Risk Information System (IRIS) database. ...

Electron correlations and two-photon states in polycyclic aromatic hydrocarbon molecules: A peculiar role of geometry

Energy Technology Data Exchange (ETDEWEB)

Aryanpour, Karan [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); Shukla, Alok [Department of Physics, Indian Institute of Technology, Powai, Mumbai 400076 (India); Mazumdar, Sumit [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States)

2014-03-14

We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene, and circumcoronene, all possessing D{sub 6h} point group symmetry versus ovalene with D{sub 2h} symmetry, within the Pariser-Parr-Pople model of interacting π-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitatively different from single-particle descriptions. More remarkably, a peculiar role of molecular geometry is found. The consequence of electron correlations is far stronger for ovalene, where the lowest spin-singlet two-photon state is a quantum superposition of pairs of lowest spin triplet states, as in the linear polyenes. The same is not true for D{sub 6h} group hydrocarbons. Our work indicates significant covalent character, in valence bond language, of the ground state, the lowest spin triplet state and a few of the lowest two-photon states in D{sub 2h} ovalene but not in those with D{sub 6h} symmetry.

Electron correlations and two-photon states in polycyclic aromatic hydrocarbon molecules: A peculiar role of geometry

International Nuclear Information System (INIS)

Aryanpour, Karan; Shukla, Alok; Mazumdar, Sumit

2014-01-01

We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene, and circumcoronene, all possessing D 6h point group symmetry versus ovalene with D 2h symmetry, within the Pariser-Parr-Pople model of interacting π-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitatively different from single-particle descriptions. More remarkably, a peculiar role of molecular geometry is found. The consequence of electron correlations is far stronger for ovalene, where the lowest spin-singlet two-photon state is a quantum superposition of pairs of lowest spin triplet states, as in the linear polyenes. The same is not true for D 6h group hydrocarbons. Our work indicates significant covalent character, in valence bond language, of the ground state, the lowest spin triplet state and a few of the lowest two-photon states in D 2h ovalene but not in those with D 6h symmetry

Electron correlations and two-photon states in polycyclic aromatic hydrocarbon molecules: a peculiar role of geometry.

Science.gov (United States)

Aryanpour, Karan; Shukla, Alok; Mazumdar, Sumit

2014-03-14

We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene, and circumcoronene, all possessing D(6h) point group symmetry versus ovalene with D(2h) symmetry, within the Pariser-Parr-Pople model of interacting π-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitatively different from single-particle descriptions. More remarkably, a peculiar role of molecular geometry is found. The consequence of electron correlations is far stronger for ovalene, where the lowest spin-singlet two-photon state is a quantum superposition of pairs of lowest spin triplet states, as in the linear polyenes. The same is not true for D(6h) group hydrocarbons. Our work indicates significant covalent character, in valence bond language, of the ground state, the lowest spin triplet state and a few of the lowest two-photon states in D(2h) ovalene but not in those with D(6h) symmetry.

Lutzomyia longipalpis in Brazil: a complex or a single species? A mini-review

Directory of Open Access Journals (Sweden)

Luiz GSR Bauzer

2007-02-01

Full Text Available Lutzomyia longipalpis is the main vector of Leishmania infantum chagasi, the causative agent of American visceral leishmaniasis (AVL. Although there is strong evidence that Lu. longipalpis is a species complex, not all data concerning populations from Brazil support this hypothesis. The issue is still somewhat controversial for this large part of Lu. longipalpis distribution range even though that it is the Latin American region contributing to most of the cases of AVL. In this mini-review we consider in detail the current data for the Brazilian populations and conclude that Lu. longipalpis is a complex of incipient vector species with a complexity similar to Anopheles gambiae s.s. in Africa.

Congenital hypogonadotropic hypogonadism: implications of absent mini-puberty.

Science.gov (United States)

Dwyer, Andrew A; Jayasena, Channa N; Quinton, Richard

2016-06-01

The phenomenon known as "mini-puberty" refers to activation of the neonatal hypothalamo-pituitary axis causing serum concentrations of gonadotrophins and testosterone (T) to approach adult male levels. This early neonatal period is a key proliferative window for testicular germ cells and immature Sertoli cells. Although failure to spontaneously initiate (adolescent) puberty is the most evident consequence of a defective gonadotropin-releasing hormone (GnRH) neurosecretory network, absent mini-puberty is also likely to have a major impact on the reproductive phenotype of men with congenital hypogonadotrophic hypogonadism (CHH). Furthermore, the phase of male mini-puberty represents a key window-of-opportunity to identify congenital GnRH deficiency (either isolated CHH, or as part of combined pituitary hormone deficiency) in childhood. Among male neonates exhibiting "red flag" indicators for CHH (i.e. maldescended testes with or without cryptorchidism) a single serum sample (between 4-8 weeks of life) can pinpoint congenital GnRH deficiency far more rapidly and with much greater accuracy than dynamic tests performed in later childhood or adolescence. Potential consequences for missing absent mini-puberty in a male neonate include the lack of monitoring of pubertal progression/lack of progression, and the missed opportunity for early therapeutic intervention. This article will review our current understanding of the mechanisms and clinical consequences of mini-puberty. Furthermore, evidence for the optimal clinical management of patients with absent mini-puberty will be discussed.

Taman Mini Indonesia Indah sebagai Bagian dari Fenomena Taman Budaya Dunia

Directory of Open Access Journals (Sweden)

Anak Agung Ayu Wulandari

2012-10-01

Full Text Available Cultural display in an open space or known as cultural parks appears rapidly as a worldwide phenomenon. From the European model which has a strong educational value, to the Asian parks which not only has educational function, but also has recreational purposes. So many types and characteristics of these parks, researches give them different names, thodse are Open-air museums, Ethnographic Theme Parks or even Theme Parks. Taman Mini Indonesia Indah as a part of this phenomenon was built first and foremost for educational purposes, therefore Taman Mini can be considered as an open-air museum. However, since Taman Mini also has recreational purposes, others can argue that Taman Mini is a theme park. Qualitative method will be used for this research, through observation to Taman Mini Indonesia Indah, followed by extensive literature review. With these data along with a table which points out the distinction between museum and theme parks. It can  be concluded that Taman Mini is a Theme Park.   

Analysis of experimental positron-molecule binding energies

International Nuclear Information System (INIS)

Danielson, J R; Surko, C M; Young, J A

2010-01-01

Experiments show that positron annihilation on molecules frequently occurs via capture into vibrational Feshbach resonances. In these cases, the downshifts in the annihilation spectra from the vibrational mode spectra provide measures of the positron-molecule binding energies. An analysis of these binding energy data is presented in terms of the molecular dipole polarizability, the permanent dipole moment, and the number of π bonds in aromatic molecules. The results of this analysis are in reasonably good agreement with other information about positron-molecule bound states. Predictions for other targets and promising candidate molecules for further investigation are discussed.

Left Ventricular Hypertrophy in Pediatric Hypertension: A Mini Review

Directory of Open Access Journals (Sweden)

Robert P. Woroniecki

2017-05-01

Full Text Available Adults with arterial hypertension (HTN have stroke, myocardial infarction, end-stage renal disease (ESRD, or die at higher rates than those without. In children, HTN leads to target organ damage, which includes kidney, brain, eye, blood vessels, and heart, which precedes “hard outcomes” observed in adults. Left ventricular hypertrophy (LVH or an anatomic and pathologic increase in left ventricular mass (LVM in response to the HTN is a pediatric surrogate marker for HTN-induced morbidity and mortality in adults. This mini review discusses current definitions, clinically relevant methods of LVM measurements and normalization methods, its epidemiology, management, and issue of reversibility in children with HTN. Pediatric definition of LVH and abnormal LVM is not uniformed. With multiple definitions, prevalence of pediatric HTN-induced LVH is difficult to ascertain. In addition while in adults cardiac magnetic resonance imaging is considered “the gold standard” for LVM and LVH determination, pediatric data are limited to “special populations”: ESRD, transplant, and obese children. We summarize available data on pediatric LVH treatment and reversibility and offer future directions in addressing LVH in children with HTN.

Electrical properties of SAM-modified ITO surface using aromatic small molecules with double bond carboxylic acid groups for OLED applications

Energy Technology Data Exchange (ETDEWEB)

Can, Mustafa [Izmir Katip Celebi University, Faculty of Engineering, Department of Engineering Sciences, Çiğli, Izmir (Turkey); Havare, Ali Kemal [Toros University, Faculty of Engineering, Electric and Electronic Department, Mersin (Turkey); Aydın, Hasan; Yagmurcukardes, Nesli [Izmir Institute of Technology, Material Science and Engineering, Izmir (Turkey); Demic, Serafettin [Izmir Katip Celebi University, Faculty of Engineering, Department of Material Science and Engineering, Çiğli, Izmir (Turkey); Icli, Sıddık [Ege University, Solar Energy Institute, Izmir (Turkey); Okur, Salih, E-mail: salih.okur@ikc.edu.tr [Izmir Katip Celebi University, Faculty of Engineering, Department of Material Science and Engineering, Çiğli, Izmir (Turkey)

2014-09-30

Graphical abstract: - Highlights: • We report that the performance of OLED consist of aromatic small molecules with double bond carboxylic acid groups on ITO surface. • The OLED devices were tested in terms of electrical and optical characteristics. • The I–V results show that OLEDs with SAM-modified ITO surface have lower turn on voltages than OLED configurations without SAMs. - Abstract: 5-[(3-Methylphenyl)(phenyl)amino]isophthalic acid (5-MePIFA) and 5-(diphenyl)amino]isophthalic acid (5-DPIFA) organic molecules were synthesized to form self-assembled monolayer on indium tin oxide (ITO) anode to enhance hole transport from ITO to organic hole transport layers such as TPD. The modified surface was characterized by scanning tunneling microscopy (STM). The change in the surface potential was measured by Kelvin probe force microscopy (KPFM). Our Kelvin probe force microscopy (KPFM) measurements showed that the surface potentials increased more than 100 mV with reference to bare indium tin-oxide. The results show that the threshold voltage on OLEDs with modified ITO is lowered significantly compared to OLEDs with unmodified ITO. The hole mobility of TPD has been estimated using space–charge-limited current measurements (SCLC)

Electrical properties of SAM-modified ITO surface using aromatic small molecules with double bond carboxylic acid groups for OLED applications

International Nuclear Information System (INIS)

Can, Mustafa; Havare, Ali Kemal; Aydın, Hasan; Yagmurcukardes, Nesli; Demic, Serafettin; Icli, Sıddık; Okur, Salih

2014-01-01

Graphical abstract: - Highlights: • We report that the performance of OLED consist of aromatic small molecules with double bond carboxylic acid groups on ITO surface. • The OLED devices were tested in terms of electrical and optical characteristics. • The I–V results show that OLEDs with SAM-modified ITO surface have lower turn on voltages than OLED configurations without SAMs. - Abstract: 5-[(3-Methylphenyl)(phenyl)amino]isophthalic acid (5-MePIFA) and 5-(diphenyl)amino]isophthalic acid (5-DPIFA) organic molecules were synthesized to form self-assembled monolayer on indium tin oxide (ITO) anode to enhance hole transport from ITO to organic hole transport layers such as TPD. The modified surface was characterized by scanning tunneling microscopy (STM). The change in the surface potential was measured by Kelvin probe force microscopy (KPFM). Our Kelvin probe force microscopy (KPFM) measurements showed that the surface potentials increased more than 100 mV with reference to bare indium tin-oxide. The results show that the threshold voltage on OLEDs with modified ITO is lowered significantly compared to OLEDs with unmodified ITO. The hole mobility of TPD has been estimated using space–charge-limited current measurements (SCLC)

DMPD: CD14 and other recognition molecules for lipopolysaccharide: a review. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 7542643 CD14 and other recognition molecules for lipopolysaccharide: a review. Kiel...her recognition molecules for lipopolysaccharide: a review. PubmedID 7542643 Title CD14 and other recognitio...n molecules for lipopolysaccharide: a review. Authors Kielian TL, Blecha F. Publi

Synthesis and bioelectrochemical behavior of aromatic amines.

Science.gov (United States)

Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Bolte, Michael; McKee, Vickie

2017-12-01

Four aromatic amines 1-amino-4-phenoxybenzene (A 1 ), 4-(4-aminophenyloxy) biphenyl (A 2 ), 1-(4-aminophenoxy) naphthalene (A 3 ) and 2-(4-aminophenoxy) naphthalene (A 4 ) were synthesized and characterized by elemental, spectroscopic (FTIR, NMR), mass spectrometric and single crystal X-ray diffraction methods. The compounds crystallized in monoclinic crystal system with space group P2 1 . Intermolecular hydrogen bonds were observed between the amine group and amine/ether acceptors of neighboring molecules. Electrochemical investigations were done using cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV). CV studies showed that oxidation of aromatic amines takes place at about 0.9 V (vs. Ag/AgCl) and the electron transfer (ET) process has irreversible nature. After first scan reactive intermediate were generated electrochemically and some other cathodic and anodic peaks also appeared in the succeeding scans. DPV study revealed that ET process is accompanied by one electron. DNA binding study of aromatic amines was performed by CV and UV-visible spectroscopy. These investigations revealed groove binding mode of interaction of aromatic amines with DNA. Copyright © 2017 Elsevier Inc. All rights reserved.

Electron Accumulative Molecules.

Science.gov (United States)

Buades, Ana B; Sanchez Arderiu, Víctor; Olid-Britos, David; Viñas, Clara; Sillanpää, Reijo; Haukka, Matti; Fontrodona, Xavier; Paradinas, Markos; Ocal, Carmen; Teixidor, Francesc

2018-02-28

With the goal to produce molecules with high electron accepting capacity and low reorganization energy upon gaining one or more electrons, a synthesis procedure leading to the formation of a B-N(aromatic) bond in a cluster has been developed. The research was focused on the development of a molecular structure able to accept and release a specific number of electrons without decomposing or change in its structural arrangement. The synthetic procedure consists of a parallel decomposition reaction to generate a reactive electrophile and a synthesis reaction to generate the B-N(aromatic) bond. This procedure has paved the way to produce the metallacarboranylviologen [M(C 2 B 9 H 11 )(C 2 B 9 H 10 )-NC 5 H 4 -C 5 H 4 N-M'(C 2 B 9 H 11 )(C 2 B 9 H 10 )] (M = M' = Co, Fe and M = Co and M' = Fe) and semi(metallacarboranyl)viologen [3,3'-M(8-(NC 5 H 4 -C 5 H 4 N-1,2-C 2 B 9 H 10 )(1',2'-C 2 B 9 H 11 )] (M = Co, Fe) electron cumulative molecules. These molecules are able to accept up to five electrons and to donate one in single electron steps at accessible potentials and in a reversible way. By targeted synthesis and corresponding electrochemical tests each electron transfer (ET) step has been assigned to specific fragments of the molecules. The molecules have been carefully characterized, and the electronic communication between both metal centers (when this situation applies) has been definitely observed through the coplanarity of both pyridine fragments. The structural characteristics of these molecules imply a low reorganization energy that is a necessary requirement for low energy ET processes. This makes them electronically comparable to fullerenes, but on their side, they have a wide range of possible solvents. The ET from one molecule to another has been clearly demonstrated as well as their self-organizing capacity. We consider that these molecules, thanks to their easy synthesis, ET, self-organizing capacity, wide range of solubility, and easy processability, can

Investigating Superhydrogenated Polycyclic Aromatic Hydrocarbons on HOPG and their catalytic abilities of H2 formation

DEFF Research Database (Denmark)

Simonsen, Frederik Doktor Skødt

Scanning tunneling microscopy and temperature programmed desorption techniques have been used to investigate adsorption and abstraction of hydrogen atoms on the polycyclic aromatic hydrocarbon, coronene. The coronene molecules were exposed to different hydrogen fluences at a dosing temperature......). Both scanning tunneling microscopy (STM) and temperature programmed desorption (TPD) techniques have been used. Coronene monolayers were prepared on graphite and exposed to different fluences of 1000K H or D atoms. STM images show brigth spots on the coronene monolayers after hydrogenation indicating...... calcutions have also been made on desorption of H from a fully hydrogenated coronene molecule. The desorption DFT calculation reveals a favourable desorption route and stable configurations consistent with our TPD measurements[5]. References [1] Tielens, A., Reviews of Modern Physics, 85 (2013) 1021-1081 [2...

Using Molecular Modeling to Understand Some of the More Subtle Aspects of Aromaticity and Antiaromaticity

Science.gov (United States)

Box, Vernon G. S.

2011-01-01

pi-Electron delocalization exerts one of the most significant structure or energy influences in organic chemistry. Apart from determining the shapes of alkenes and alkynes, the planarity of aromatic molecules is a hallmark of pi-electron delocalization. Huckel's rules for aromaticity are easily applied in the teaching of undergraduates, but…

The formation of aromatics and PAH's in laminar flames

International Nuclear Information System (INIS)

Marinov, N M; Pitz, W J; Westbrook, C K

1999-01-01

The formation of aromatics and PAH's is an important problem in combustion. These compounds are believed to contribute to the formation of soot whose emission from diesel engines is regulated widely throughout the industrial world. Additionally, the United States Environmental Protection Agency regulates the emission of many aromatics and PAH species from stationary industrial burners, under the 1990 Clean Air Act Amendments. The above emission regulations have created much interest in understanding how these species are formed in combustion systems. Much previous work has been done on aromatics and PAH's. The work is too extensive to review here, but is reviewed in Reference 1. A few recent developments are highlighted here. McEnally, Pfefferle and coworkers have studied aromatic, PAH and soot formation in a variety of non-premixed flames with hydrocarbon additives[2-4]. They found additives that contain a C5 ring increase the concentration of aromatics and soot[4]. Howard and coworkers have studied the formation of aromatic and PAH's in low pressure, premixed, laminar hydrocarbon flames. They found the cyclopentadienyl radical to be a key species in naphthalene formation in a fuel-rich, benzene/Ar/O2 flame[5

Experimental and Computational Characterization of Biological Liquid Crystals: A Review of Single-Molecule Bioassays

Directory of Open Access Journals (Sweden)

Sungsoo Na

2009-09-01

Full Text Available Quantitative understanding of the mechanical behavior of biological liquid crystals such as proteins is essential for gaining insight into their biological functions, since some proteins perform notable mechanical functions. Recently, single-molecule experiments have allowed not only the quantitative characterization of the mechanical behavior of proteins such as protein unfolding mechanics, but also the exploration of the free energy landscape for protein folding. In this work, we have reviewed the current state-of-art in single-molecule bioassays that enable quantitative studies on protein unfolding mechanics and/or various molecular interactions. Specifically, single-molecule pulling experiments based on atomic force microscopy (AFM have been overviewed. In addition, the computational simulations on single-molecule pulling experiments have been reviewed. We have also reviewed the AFM cantilever-based bioassay that provides insight into various molecular interactions. Our review highlights the AFM-based single-molecule bioassay for quantitative characterization of biological liquid crystals such as proteins.

Mini-conference on Angular Momentum Transport in Laboratory and Nature

International Nuclear Information System (INIS)

Ji, Hantao; Kronberg, Philipp; Prager, Stewart C.; Uzdensky, Dmitri A.

2008-01-01

This paper provides a concise summary of the current status of the research and future perspectives discussed in the Mini-Conference on Angular Momentum Transport in Laboratory and Nature. This Mini-conference, sponsored by the Topical Group on Plasma Astrophysics, was held as part of the American Physical Society's Division of Plasma Physics 2007 Annual Meeting (November 12-16, 2007). This Mini-conference covers a wide range of phenomena happening in fluids and plasmas, either in laboratory or in nature. The purpose of this paper is not to comprehensively review these phenomena, but to provide a starting point for interested readers to refer to related research in areas other than their own

Aromatic Amino Acids-Guanidinium Complexes through Cation-π Interactions

Directory of Open Access Journals (Sweden)

Cristina Trujillo

2015-05-01

Full Text Available Continuing with our interest in the guanidinium group and the different interactions than can establish, we have carried out a theoretical study of the complexes formed by this cation and the aromatic amino acids (phenylalanine, histidine, tryptophan and tyrosine using DFT methods and PCM-water solvation. Both hydrogen bonds and cation-π interactions have been found upon complexation. These interactions have been characterized by means of the analysis of the molecular electron density using the Atoms-in-Molecules approach as well as the orbital interactions using the Natural Bond Orbital methodology. Finally, the effect that the cation-π and hydrogen bond interactions exert on the aromaticity of the corresponding amino acids has been evaluated by calculating the theoretical NICS values, finding that the aromatic character was not heavily modified upon complexation.

Evaluation and treatment of erectile dysfunction in the aging male: a mini-review.

Science.gov (United States)

Albersen, Maarten; Orabi, Hazem; Lue, Tom F

2012-01-01

Before the 20th century, individuals often did not live beyond the reproductive years, and sexuality of the elderly was not an issue. However, in the current era it is known that as life expectancy improves, both men and women are seeking to preserve their sexuality into old age. While the appreciation of sexuality persists with aging, a decline in sexual activity is typically seen with, and can be attributed to both general health problems as well as specific sexual dysfunctions. Erectile dysfunction is the most frequently diagnosed sexual dysfunction in the older male population. This mini-review provides an overview of contemporary literature concerning epidemiology, pathophysiology, assessment and treatment of erectile dysfunction in the aging male. Copyright © 2011 S. Karger AG, Basel.

Self-assembled electrical materials from contorted aromatics

Science.gov (United States)

Xiao, Shengxiong

This thesis describes the design, synthesis, self-assembly and electrical properties of new types of contorted polycyclic aromatic hydrocarbons. These topologically interesting contorted aromatics show promising transistor characteristics as new building blocks for organic field-effect transistors (OFETs) at different length scales. In chapter 2, a class of pentacenes that are substituted along their long edges with aromatic rings were synthesized. Their solid-state assemblies were studied by X-ray crystallography. Their performance as thin film transistors (TFTs) and single crystal field effect transistors (SCFETs) were systematically evaluated. A structure-property relationship between these highly phenylated pentacenes was found. Chapter 3 explores the new concept of whether a non-planar aromatic core could yield efficacious electronic materials, as the ultimate success in the organic electronics will require a holistic approach to creating new building blocks. Synthesis, functionalization and assembly of a new type of contorted hexabenzocoronene (HBC) whose aromatic core is heavily distorted away from planarity due to the steric congestion around its proximal carbons were discussed. Structural studies by X-ray crystallography showed that these HBC molecules stack into columnar structures in the solid state, which are ideal for conduction. Chapter 4 describes that microscale liquid crystalline thin film OFETs of tetradodecyloxy HBC showed the best transistor properties of all discotic columnar materials. Chapter 5 details the fabrication and characterization of nanoscale single crystalline fiber OFETs of octadodecyloxyl HBC. In Chapter 6 we show that a molecular scale monolayer of HBC acid chlorides could be self-assembled on SiO2 insulating layer and could be organized laterally between the ends of 2 nm carbon nanotube gaps to form high quality FETs that act as environmental and chemical sensors. Chapter 7 details the enforced one-dimensional photoconductivity

Modulating Spatial Processes and Navigation via Transcranial Electrical Stimulation: A Mini Review

Directory of Open Access Journals (Sweden)

Tad T. Brunyé

2018-01-01

Full Text Available Transcranial electrical stimulation (tES uses low intensity current to alter neuronal activity in superficial cortical regions, and has gained popularity as a tool for modulating several aspects of perception and cognition. This mini-review article provides an overview of tES and its potential for modulating spatial processes underlying successful navigation, including spatial attention, spatial perception, mental rotation and visualization. Also considered are recent advances in empirical research and computational modeling elucidating several stable cortical-subcortical networks with dynamic involvement in spatial processing and navigation. Leveraging these advances may prove valuable for using tES, particularly transcranial direct and alternating current stimulation (tDCS/tACS, to indirectly target subcortical brain regions by altering neuronal activity in distant yet functionally connected cortical areas. We propose future research directions to leverage these advances in human neuroscience.

Sensory and aromatic characteristics of tongue sole by-products hydrolysates (Cynoglossus senegalensis)

OpenAIRE

Sylla, K. S. B.; Berge, Jean-pascal; Prost, Carole; Musabyemariya, B.; Seydi, Mg

2009-01-01

Tongue sole by-products coming from fish-filleting plant were hydrolyzed by Protamex® protease. To identify the future application of hydrolysates, a sensory analysis was carried out.The sensory profile was performed with a jury of 14 specialized judges.11 profiles were found by this panel of tasting. In addition, the aromatic characterization revealed that 57 molecules are responsible for these odours described in sensory analysis.The description of these aromatic compounds opens potentia...

Extremely long aromatics: diastereomerically pure [19]helicene

Czech Academy of Sciences Publication Activity Database

Nejedlý, Jindřich; Rybáček, Jiří; Stará, Irena G.; Starý, Ivo

2016-01-01

Roč. 14, č. 2 (2016), s. 78-79 ISSN 2336-7202. [Mezioborové setkání mladých biologů, biochemiků a chemiků /16./. 10.05.2016-13.05.2016, Milovy] R&D Projects: GA ČR(CZ) GA16-08294S Institutional support: RVO:61388963 Keywords : long helicene * long aromatics * chiral molecules Subject RIV: CC - Organic Chemistry

Absolute fragmentation cross sections in atom-molecule collisions : Scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules

NARCIS (Netherlands)

Chen, T.; Gatchell, M.; Stockett, M. H.; Alexander, J. D.; Zhang, Y.; Rousseau, P.; Domaracka, A.; Maclot, S.; Delaunay, R.; Adoui, L.; Huber, B. A.; Schlathölter, T.; Schmidt, H. T.; Cederquist, H.; Zettergren, H.

2014-01-01

We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH+) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections

Use of heterologous expressed polyketide synthase and small molecule foldases to make aromatic and cyclic compounds

DEFF Research Database (Denmark)

2016-01-01

A method for producing individual or libraries of tri- to pentadecaketide-derived aromatic compounds of interest by heterologous expression of polyketide synthase and aromatase/cyclase in a recombinant host cell.......A method for producing individual or libraries of tri- to pentadecaketide-derived aromatic compounds of interest by heterologous expression of polyketide synthase and aromatase/cyclase in a recombinant host cell....

Kinematic anharmonicity of internal rotation of molecules

International Nuclear Information System (INIS)

Bataev, V.A.; Pupyshev, V.I.; Godunov, I.A.

2017-01-01

The methods of analysis the strongly coupled vibrations are proposed for a number of molecules of aromatic and heterocyclic carbonyl (and some others) compounds. The qualitative principles are formulated for molecular systems with a significant kinematic anharmonicity.

Effect of dietary macronutrients on aflatoxicosis: a mini-review.

Science.gov (United States)

Nurul Adilah, Zainuddin; Mohd Redzwan, Sabran

2017-06-01

Aflatoxin is a toxin produced by Aspergillus species of fungi. The main route of aflatoxin exposure is through the diet. Indeed, long-term aflatoxin exposure is linked to the development of hepatocellular carcinoma (HCC). Aflatoxin causes aflatoxicosis, which can be affected by several factors and is prevalent in many developing Asian and African countries. This mini-review discusses the effects of carbohydrate, fat and protein on aflatoxicosis based on findings from animal and human studies. It was found that high carbohydrate intake enhanced aflatoxicosis occurrence, while low ingestion of carbohydrate with caloric restriction slowed the symptoms associated with aflatoxicosis. Additionally, diets with low protein content worsened the symptoms related to HCC due to aflatoxin exposure. Nevertheless, a study reported that a high-protein diet favored detoxification of aflatoxin in vivo. There were also conflicting results on the influence of dietary fat, as high ingestion of fat enhanced aflatoxicosis development as compared with a low-fat diet. Moreover, the type of fat also plays a significant role in influencing aflatoxin toxicity. In regard to food safety, understanding the influence of macronutrients toward the progression of aflatoxicosis can improve preventive measures against human and animal exposure to aflatoxin. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

A review of atmospheric polycyclic aromatic hydrocarbons: sources, fate and behavior

International Nuclear Information System (INIS)

Baek, S.O.; Field, R.A.; Goldstone, M.E.; Kirk, P.W.; Lester, J.N.; Perry, R.

1991-01-01

A review has been written to assess the sources, fate and behavior of polycyclic aromatic hydrocarbons (PAH) in the atmosphere. PAH are formed mainly by anthropogenic processes, especially the combustion of organic fuels. PAH concentration in air will reflect the location of source emitters, with high concentrations corresponding with urban and industrial areas. PAH are however ubiquitous contaminants of the environment having been detected in remote areas of the world. This is thought to be due to long term transport in the atmosphere. PAH can also be subjected to chemical and/or photochemical change whilst resident in the atmosphere prior to their removal by either wet or dry deposition. 146 refs., 5 tabs

Development of miniaturized submersible fluorometers for the detection of aromatic hydrocarbons in marine waters

Science.gov (United States)

Tedetti, Marc; Bachet, Caroline; Joffre, Pascal; Ferretto, Nicolas; Guigue, Catherine; Goutx, Madeleine

2014-05-01

Polycyclic aromatic hydrocarbons (PAHs) are among the most widespread organic contaminants in aquatic environments. Due to their physico-chemical properties, PAHs are persistent and mobile, can strongly bioaccumulate in food chains and are harmful to living organisms. They are thus recognized by various international organizations as priority contaminants and are included in the list of 45 priority regulated substances by the European Union. Because of their aromatic structure, PAHs are "optically active" and have inherent fluorescence properties in the ultraviolet (UV) spectral domain (200-400 nm). Therefore, UV fluorescence spectroscopy has been successfully used to develop PAH sensors (i.e. UV fluorometers). Currently, five UV submersible fluorometers are commercially available for in situ measurements of PAHs: EnviroFlu-HC (TriOS Optical Sensors, Germany), Hydrocarbon Fluorometer (Sea & Sun Technology, Germany), HydroC ™ / PAH (CONTROS, Germany), UviLux AquaTracka (Chelsea Technology Group, UK) and Cyclops-7 (Turner Designs, US). These UV fluorometers are all dedicated to the measurement of phenanthrene (λEx /λEm: 255/360 nm), one of the most abundant and fluorescent PAHs found in the aquatic environment. In this study, we developed original, miniaturized submersible fluorometers based on deep UV light-emitting diodes (LEDs) for simultaneous measurements of two PAHs of interest: the MiniFluo-UV 1 for the detection of phenanthrene (PHE, at λEx /λEm: 255/360 nm) and naphthalene (NAP, at λEx /λEm: 270/340 nm), and the MiniFluo-UV 2 for the detection of fluorene (FLU, at λEx /λEm: 255/315 nm) and pyrene (PYR, at λEx /λEm: 270/380 nm). The MiniFluo-UV sensors have several features: measurements of two PAHs at the same time, small size (puck format, 80 x 60 mm), very low energy consumption (500 mW at 12V), LED monitoring, analog and numerical communication modes. The two MiniFluo-UV sensors were first tested in the laboratory: 1) on standard solutions of

On the formation of molecules and solid-state compounds from the AGB to the PN phases

Science.gov (United States)

García-Hernández, D. A.; Manchado, A.

2016-07-01

During the asymptoyic giant branch (AGB) phase, different elements are dredge- up to the stellar surface depending on progenitor mass and metallicity. When the mass loss increases at the end of the AGB, a circumstellar dust shell is formed, where different (C-rich or O-rich) molecules and solid-state compounds are formed. These are further processed in the transition phase between AGB stars and planetary nebulae (PNe) to create more complex organic molecules and inorganic solid-state compounds (e.g., polycyclic aromatic hydrocarbons, fullerenes, and graphene precursors in C-rich environments and oxides and crystalline silicates in O-rich ones). We present an observational review of the different molecules and solid-state materials that are formed from the AGB to the PN phases. We focus on the formation routes of complex fullerene (and fullerene-based) molecules as well as on the level of dust processing depending on metallicity.

Polycyclic aromatic hydrocarbons as a tracer of star formation?

NARCIS (Netherlands)

Peeters, E; Spoon, HWW; Tielens, AGGM

2004-01-01

Infrared (IR) emission features at 3.3, 6.2, 7.7, 8.6, and 11.3 mum are generally attributed to IR fluorescence from ( mainly) far-ultraviolet (FUV) pumped large polycyclic aromatic hydrocarbon (PAH) molecules. As such, these features trace the FUV stellar flux and are thus a measure of star

Recent Advances in Microbial Production of Aromatic Chemicals and Derivatives.

Science.gov (United States)

Noda, Shuhei; Kondo, Akihiko

2017-08-01

Along with the development of metabolic engineering and synthetic biology tools, various microbes are being used to produce aromatic chemicals. In microbes, aromatics are mainly produced via a common important precursor, chorismate, in the shikimate pathway. Natural or non-natural aromatics have been produced by engineering metabolic pathways involving chorismate. In the past decade, novel approaches have appeared to produce various aromatics or to increase their productivity, whereas previously, the targets were mainly aromatic amino acids and the strategy was deregulating feedback inhibition. In this review, we summarize recent studies of microbial production of aromatics based on metabolic engineering approaches. In addition, future perspectives and challenges in this research area are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Psychometric properties of a sign language version of the Mini International Neuropsychiatric Interview (MINI).

Science.gov (United States)

Øhre, Beate; Saltnes, Hege; von Tetzchner, Stephen; Falkum, Erik

2014-05-22

There is a need for psychiatric assessment instruments that enable reliable diagnoses in persons with hearing loss who have sign language as their primary language. The objective of this study was to assess the validity of the Norwegian Sign Language (NSL) version of the Mini International Neuropsychiatric Interview (MINI). The MINI was translated into NSL. Forty-one signing patients consecutively referred to two specialised psychiatric units were assessed with a diagnostic interview by clinical experts and with the MINI. Inter-rater reliability was assessed with Cohen's kappa and "observed agreement". There was 65% agreement between MINI diagnoses and clinical expert diagnoses. Kappa values indicated fair to moderate agreement, and observed agreement was above 76% for all diagnoses. The MINI diagnosed more co-morbid conditions than did the clinical expert interview (mean diagnoses: 1.9 versus 1.2). Kappa values indicated moderate to substantial agreement, and "observed agreement" was above 88%. The NSL version performs similarly to other MINI versions and demonstrates adequate reliability and validity as a diagnostic instrument for assessing mental disorders in persons who have sign language as their primary and preferred language.

Psychometric properties of a sign language version of the Mini International Neuropsychiatric Interview (MINI)

Science.gov (United States)

2014-01-01

Background There is a need for psychiatric assessment instruments that enable reliable diagnoses in persons with hearing loss who have sign language as their primary language. The objective of this study was to assess the validity of the Norwegian Sign Language (NSL) version of the Mini International Neuropsychiatric Interview (MINI). Methods The MINI was translated into NSL. Forty-one signing patients consecutively referred to two specialised psychiatric units were assessed with a diagnostic interview by clinical experts and with the MINI. Inter-rater reliability was assessed with Cohen’s kappa and “observed agreement”. Results There was 65% agreement between MINI diagnoses and clinical expert diagnoses. Kappa values indicated fair to moderate agreement, and observed agreement was above 76% for all diagnoses. The MINI diagnosed more co-morbid conditions than did the clinical expert interview (mean diagnoses: 1.9 versus 1.2). Kappa values indicated moderate to substantial agreement, and “observed agreement” was above 88%. Conclusion The NSL version performs similarly to other MINI versions and demonstrates adequate reliability and validity as a diagnostic instrument for assessing mental disorders in persons who have sign language as their primary and preferred language. PMID:24886297

Nucleobases in Space: Laboratory Studies of Polycyclic Aromatic Nitrogen Heterocycles

Science.gov (United States)

Elsila, Jamie; Mattioda, Andy; Bernstein, Max; Sandford, Scott; Hudgins, Doug

2005-01-01

Polycyclic Aromatic Nitrogen Heterocycles (PANHs) are heterocyclic aromatics Le., PAHs with carbon atoms replaced by a nitrogen atom. These molecules have been detected in meteorite extracts, and in general these nitrogen heterocycles are of astrobiological interest since this class of molecules include nucleobases, basic components of our nucleic acids. These compounds are predicted to be present in the interstellar medium and in Titan tholin, but have received relatively little attention. We will present spectra and reactions of PANHs, frozen in solid H2O at 12 K, conditions germane to astronomical observations. In contrast to simple PAHs, that do not interact strongly with solid H2O, the nitrogen atoms in PANHs are potentially capable of hydrogen bonding with H20 changing their spectra, complicating their remote detection on the surfaces of icy bodies. Moreover, we have studied the photo-chemistry of these interesting compounds under astrophysical conditions and will use our lab studies to assess a potential interstellar heritage of these compounds in carbonaceous chondrites.

Formation of Polycyclic Aromatic Hydrocarbons and Nitrogen Containing Polycyclic Aromatic Compounds in Titan's Atmosphere, the Interstellar Medium and Combustion

Science.gov (United States)

Landera, Alexander

2013-12-01

Several different mechanisms leading to the formation of (substituted) naphthalene and azanaphthalenes were examined using theoretical quantum chemical calculations. As a result, a series of novel synthetic routes to Polycyclic Aromatic Hydrocarbons (PAHs) and Nitrogen Containing Polycyclic Aromatic Compounds (N-PACs) have been proposed. On Earth, these aromatic compounds originate from incomplete combustion and are released into our environment, where they are known to be major pollutants, often with carcinogenic properties. In the atmosphere of a Saturn's moon Titan, these PAH and N-PACs are believed to play a critical role in organic haze formation, as well as acting as chemical precursors to biologically relevant molecules. The theoretical calculations were performed by employing the ab initio G3(MP2,CC)/B3LYP/6-311G** method to effectively probe the Potential Energy Surfaces (PES) relevant to the PAH and N-PAC formation. Following the construction of the PES, Rice-Ramsperger-Kassel-Markus (RRKM) theory was used to evaluate all unimolecular rate constants as a function of collision energy under single-collision conditions. Branching ratios were then evaluated by solving phenomenological rate expressions for the various product concentrations. The most viable pathways to PAH and N-PAC formation were found to be those where the initial attack by the ethynyl (C2H) or cyano (CN) radical toward a unsaturated hydrocarbon molecule led to the formation of an intermediate which could not effectively lose a hydrogen atom. It is not until ring cyclization has occurred, that hydrogen elimination leads to a closed shell product. By quenching the possibility of the initial hydrogen atom elimination, one of the most competitive processes preventing the PAH or N-PAC formation was avoided, and the PAH or N-PAC formation was allowed to proceed. It is concluded that these considerations should be taken into account when attempting to explore any other potential routes towards

Graphene and graphene nanocomposites for the removal of aromatic organic compounds from the water: systematic review

Science.gov (United States)

Monsores Paixão, Monique; Tadeu Gomes Vianna, Marco; Marques, Marcia

2018-01-01

Aromatic organic pollutants are highly toxic to the human and environmental health and are considered as priority pollutants by regulatory agencies. Managing contaminated sites with organic pollutants is one of the major environmental challenges today. Of all technologies that have been proposed to remove contaminants, adsorption is recognized worldwide as an attractive option due to its versatility, wide applicability and economic viability. Recent studies report the use of graphene (GN), a recently carbon nanomaterial, and its derivatives in sorption processes for the removal of aromatic organic compounds. The present review has shown that GN structures are a promising alternative to traditional adsorbent materials, with excellent results in the removal of organic compounds from water, due to their unique structural characteristics and great adsorption capacity for organic compounds. Although, there is still a long way to go until that practical applications can be implemented.

Return of the mini

International Nuclear Information System (INIS)

Ashmore, C.

2001-01-01

Partly as a result of the contentious nature of some large hydroelectric schemes, and continuing deregulation on a global scale, the mini hydro systems are enjoying unprecedented growth. This article discusses the reasons for the increase in demand for mini hydro systems, and describes Alstom Power Hydro's new, integrated 'water-to-wire' renewable energy solution which is a modular system which integrates the hydro-turbine, generator and controls to provide a single optimised product called the Mini-Aqua. The Mini-Aqua can be supplied inside a turnkey package including all civil works. The company is also looking to the future with development of its Powerformer technology for smaller-scale, grid-connected applications

Consistência interna da versão em português do Mini-Inventário de Fobia Social (Mini-SPIN Internal consistency of the Portuguese version of the Mini-Social Phobia Inventory (Mini-SPIN

Directory of Open Access Journals (Sweden)

Gustavo J. Fonseca D'El Rey

2007-01-01

Full Text Available CONTEXTO: A fobia social é um grave transtorno de ansiedade que traz incapacitação e sofrimento. OBJETIVOS: Investigar a consistência interna da versão em português do Mini-Inventário de Fobia Social (Mini-SPIN. MÉTODOS: Foi realizado um estudo da consistência interna do Mini-SPIN em uma amostra de 206 estudantes universitários da cidade de São Paulo, SP. RESULTADOS: A consistência interna do instrumento, analisada pelo coeficiente alfa de Cronbach, foi de 0,81. CONCLUSÕES: Esses achados permitiram concluir que a versão em português do Mini-SPIN exibiu resultados de boa consistência interna, semelhantes aos da versão original em inglês.BACKGROUND: Social phobia is a severe anxiety disorder that brings disability and distress. OBJECTIVES: To investigate the internal consistency of the Portuguese version of the Mini-Social Phobia Inventory (Mini-SPIN. METHODS: We conducted a study of internal consistency of the Mini-SPIN in a sample of 206 college students of the city of São Paulo, SP. RESULTS: The internal consistency of the instrument, analyzed by Cronbach's alpha coefficient, was 0.81. CONCLUSIONS: These findings suggest that the Portuguese version of the Mini-SPIN has a good internal consistency, similar to those obtained with the original English version.

Mini-review

Indian Academy of Sciences (India)

Since change in growth rate must be accompanied by changes in cell cycle parameters set through the activities of the DNA replication and cell division apparatus, (p)ppGpp could coordinate protein synthesis (cell mass increase) with these processes. Here we review the role of (p)ppGpp in bacterial cell cycle regulation.

Polycyclic aromatic hydrocarbons in disks around young solar-type stars

NARCIS (Netherlands)

Geers, Vincent Carlo

2007-01-01

In this thesis we study the dust around solar-type young stars. In particular, we focus on one specific species of dust, namely the Polycyclic Aromatic Hydrocarbons (PAHs), a family of large molecules, or small grains, that are widely observed in nearby star-forming regions. We address the following

Non-Markovian response of ultrafast coherent electronic ring currents in chiral aromatic molecules in a condensed phase

International Nuclear Information System (INIS)

Mineo, H.; Lin, S. H.; Fujimura, Y.; Xu, J.; Xu, R. X.; Yan, Y. J.

2013-01-01

Results of a theoretical study on non-Markov response for femtosecond laser-driven coherent ring currents in chiral aromatic molecules embedded in a condensed phase are presented. Coherent ring currents are generated by coherent excitation of a pair of quasi-degenerated π-electronic excited states. The coherent electronic dynamical behaviors are strongly influenced by interactions between the electronic system and phonon bath in a condensed phase. Here, the bath correlation time is not instantaneous but should be taken to be a finite time in ultrashort time-resolved experiments. In such a case, Markov approximation breaks down. A hierarchical master equation approach for an improved semiclassical Drude dissipation model was adopted to examine the non-Markov effects on ultrafast coherent electronic ring currents of (P)-2,2 ′ -biphenol in a condensed phase. Time evolution of the coherent ring current derived in the hierarchical master equation approach was calculated and compared with those in the Drude model in the Markov approximation and in the static limit. The results show how non-Markovian behaviors in quantum beat signals of ring currents depend on the Drude bath damping constant. Effects of temperatures on ultrafast coherent electronic ring currents are also clarified

Graphic software ''MiniG'' for the Mini-6

International Nuclear Information System (INIS)

Zen, J.

1984-06-01

MiniG is a set of subprograms, written and aimed at being used in Fortran for graphic applications in nuclear physics (histograms or point clouds). It includes three representation modes of axis scales (linear, semi-log and squared root), five types of vectors and numerous graphic symbols for spectra representation with or without notation (circle, cross, arrow, triangle, spiral, etc.). It offers also the possibilities of the software ''Plot-10'' of Tektronix, and accept all the types of graphic terminals of SATD connected to Mini-6 [fr

Frontal EEG Asymmetry of Mood: A Mini-Review

Directory of Open Access Journals (Sweden)

Massimiliano Palmiero

2017-11-01

Full Text Available The present mini-review was aimed at exploring the frontal EEG asymmetry of mood. With respect to emotion, interpreted as a discrete affective process, mood is more controllable, more nebulous, and more related to mind/cognition; in addition, causes are less well-defined than those eliciting emotion. Therefore, firstly, the rational for the distinction between emotion and mood was provided. Then, the main frontal EEG asymmetry models were presented, such as the motivational approach/withdrawal, valence/arousal, capability, and inhibition asymmetric models. Afterward, the frontal EEG asymmetry of mood was investigated following three research lines, that is considering studies involving different mood induction procedures, dispositional mood (positive and negative affect, and mood alterations in both healthy and clinical populations. In general, results were found to be contradictory, no model is unequivocally supported regardless the research line considered. Different methodological issues were raised, such as: the composition of samples used across studies, in particular, gender and age were found to be critical variables that should be better addressed in future studies; the importance of third variables that might mediate the relationship between frontal EEG asymmetries and mood, for example bodily states and hormonal responses; the role of cognition, namely the interplay between mood and executive functions. In light of these issues, future research directions were proposed. Amongst others, the need to explore the neural connectivity that underpins EEG asymmetries, and the need to include both positive and negative mood conditions in the experimental designs have been highlighted.

Photoionization of environmentally polluting aromatic chlorides and nitrides on the water surface by laser and synchrotron radiations.

Science.gov (United States)

Sato, Miki; Maeda, Yuki; Ishioka, Toshio; Harata, Akira

2017-11-20

The detection limits and photoionization thresholds of polycyclic aromatic hydrocarbons and their chlorides and nitrides on the water surface are examined using laser two-photon ionization and single-photon ionization, respectively. The laser two-photon ionization methods are highly surface-selective, with a high sensitivity for aromatic hydrocarbons tending to accumulate on the water surface in the natural environment due to their highly hydrophobic nature. The dependence of the detection limits of target aromatic molecules on their physicochemical properties (photoionization thresholds relating to excess energy, molar absorptivity, and the octanol-water partition coefficient) is discussed. The detection limit clearly depends on the product of the octanol-water partition coefficient and molar absorptivity, and no clear dependence was found on excess energy. The detection limits of laser two-photon ionization for these types of molecules on the water surface are formulated.

Dancing as an Intervention Tool for People with Dementia: A Mini-Review Dancing and Dementia.

Science.gov (United States)

Klimova, Blanka; Valis, Martin; Kuca, Kamil

2017-01-01

Research studies show a positive impact of physical activities such as dancing on the improvement of cognitive reserves of people with dementia. The purpose of this study is to explore dancing efficacy on people with dementia and list the key benefits and limitations of dancing therapy for these people. The methods used in this study include a method of literature review of available Englishwritten sources with respect to the dancing therapy and dementia in the acknowledged databases Pub- Med, Web of Science, Springer, and Scopus, and a method of comparison and evaluation of their findings. The findings of this mini review confirm positive efficacy of dancing therapy on cognitive, physical, emotional and social performance of people with dementia. More randomized controlled clinical trials should be conducted in this field, as well as other non-pharmacological therapies should be employed in order to holistically contribute to the prevention and treatment of dementia. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A neurotoxicity assessment of high flash aromatic naphtha.

Science.gov (United States)

Douglas, J F; McKee, R H; Cagen, S Z; Schmitt, S L; Beatty, P W; Swanson, M S; Schreiner, C A; Ulrich, C E; Cockrell, B Y

1993-01-01

Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide-boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 Aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent also known as High Flash Aromatic Naphtha (HFAN). A program was initiated to assess the toxicological properties of HFAN since there may be human exposure, especially in the workplace. The current study was conducted to assess the potential for neurotoxicity in the rat. Adult male Sprague-Dawley rats of approximately 300 grams body weight, in groups of twenty, were exposed by inhalation to HFAN for 90 days at concentrations of 0, 100, 500, and 1500 ppm. During this period the animals were tested monthly for motor activity and in a functional observation battery. After three months of exposure, for 6 hours/day, 5 days/week, 10 animals/group/sex were sacrificed and selected nervous system tissue was examined histopathologically. No signs of neurotoxicity were seen in any of the evaluated parameters, nor was there evidence of pathologic changes in any of the examined tissues.

[Validation of the portuguese version of the Mini-Social Phobia Inventory (Mini-SPIN)].

Science.gov (United States)

D'El Rey, Gustavo José Fonseca; Matos, Cláudia Wilmor

2009-01-01

Social phobia (also known as social anxiety disorder) is a severe mental disorder that brings distress and disability. The aim of this study was validate to the Portuguese language the Mini-Social Phobia Inventory (Mini-SPIN) in a populational sample. We performed a discriminative validity study of the Mini-SPIN in a sample of 644 subjects (Mini-SPIN positive group: n = 218 and control/negative group: n = 426) of a study of anxiety disorders' prevalence in the city of Santo André-SP. The Portuguese version of the Mini-SPIN (with score of 6 points, suggested in the original English version) demonstrated a sensitivity of 95.0%, specificity of 80.3%, positive predictive value of 52.8%, negative predictive value of 98.6% and incorrect classification rate of 16.9%. With score of 7 points, was observed an increase in the specificity and positive predictive value (88.6% and 62.7%), while the sensitivity and negative predictive value (84.8% and 96.2%) remained high. The Portuguese version of the Mini-SPIN showed satisfactory psychometric qualities in terms of discriminative validity. In this study, the cut-off of 7, was considered to be the most suitable to screening of the generalized social phobia.

Monitoring of environmental exposure to polycyclic aromatic hydrocarbons: a review.

Science.gov (United States)

Srogi, K

2007-01-01

Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds with two or more fused aromatic rings. They have a relatively low solubility in water, but are highly lipophilic. Most of the PAHs with low vapour pressure in the air are adsorbed on particles. When dissolved in water or adsorbed on particulate matter, PAHs can undergo photodecomposition when exposed to ultraviolet light from solar radiation. In the atmosphere, PAHs can react with pollutants such as ozone, nitrogen oxides and sulfur dioxide, yielding diones, nitro- and dinitro-PAHs, and sulfonic acids, respectively. PAHs may also be degraded by some microorganisms in the soil. PAHs are widespread environmental contaminants resulting from incomplete combustion of organic materials. The occurrence is largely a result of anthropogenic emissions such as fossil fuel-burning, motor vehicle, waste incinerator, oil refining, coke and asphalt production, and aluminum production, etc. PAHs have received increased attention in recent years in air pollution studies because some of these compounds are highly carcinogenic or mutagenic. Eight PAHs (Car-PAHs) typically considered as possible carcinogens are: benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene (B(a)P), dibenzo(a,h)anthracene, indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene. In particular, benzo(a)pyrene has been identified as being highly carcinogenic. The US Environmental Protection Agency (EPA) has promulgated 16 unsubstituted PAHs (EPA-PAH) as priority pollutants. Thus, exposure assessments of PAHs in the developing world are important. The scope of this review will be to give an overview of PAH concentrations in various environmental samples and to discuss the advantages and limitations of applying these parameters in the assessment of environmental risks in ecosystems and human health. As it well known, there is an increasing trend to use the behavior of pollutants (i.e. bioaccumulation) as well

P A Mini

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. P A Mini. Articles written in Bulletin of Materials Science. Volume 36 Issue 4 August 2013 pp 547-551. Composite supercapacitor electrodes made of activated carbon/PEDOT:PSS and activated carbon/doped PEDOT · T S Sonia P A Mini R Nandhini Kalluri Sujith Balakrishnan ...

POLYCYCLIC AROMATIC HYDROCARBONS WITH ARMCHAIR EDGES AND THE 12.7 μm BAND

International Nuclear Information System (INIS)

Candian, A.; Tielens, A. G. G. M.; Sarre, P. J.

2014-01-01

In this Letter, we report the results of density functional theory calculations on medium-sized neutral polycyclic aromatic hydrocarbon (PAH) molecules with armchair edges. These PAH molecules possess strong C-H stretching and bending modes around 3 μm and in the fingerprint region (10-15 μm), and also strong ring deformation modes around 12.7 μm. Perusal of the entries in the NASA Ames PAHs Database shows that ring deformation modes of PAHs are common, although generally weak. Therefore, we propose that armchair PAHs with N C > 65 are responsible for the 12.7 μm aromatic infrared band in H II regions and discuss the astrophysical implications in the context of the PAH life cycle

Quinoidal Oligo(9,10-anthryl)s with Chain-Length-Dependent Ground States: A Balance between Aromatic Stabilization and Steric Strain Release

KAUST Repository

Lim, Zhenglong; Zheng, Bin; Huang, Kuo-Wei; Liu, Ye; Wu, Jishan

2015-01-01

: the large steric repulsion between the anthryl/phenyl units in the closed-shell quinoidal form that drives the molecule to a flexible open-shell diradical structure, and aromatic stabilisation due to the gain of more aromatic sextet rings in the closed

Arc-to-arc mini-sling 1999: a critical analysis of concept and technology

Directory of Open Access Journals (Sweden)

Paulo Palma

2011-04-01

Full Text Available PURPOSE: The aim of this study was to critically review the Arc-to-Arc mini-sling (Palma's technique a less invasive mid-urethral sling using bovine pericardium as the sling material. MATERIALS AND METHODS: The Arc-to-Arc mini-sling, using bovine pericardium, was the first published report of a mini-sling, in 1999. The technique was identical to the "tension-free tape" operation, midline incision and dissection of the urethra. The ATFP (white line was identified by blunt dissection, and the mini-sling was sutured to the tendinous arc on both sides with 2 polypropylene 00 sutures. RESULTS: The initial results were encouraging, with 9/10 patients cured at the 6 weeks post-operative visit. However, infection and extrusion of the mini-sling resulted in sling extrusion and removal, with 5 patients remaining cured at 12 months. CONCLUSION: The Arc-to-Arc mini-sling was a good concept, but failed because of the poor technology available at that time. Further research using new materials and better technology has led to new and safer alternatives for the management of stress urinary incontinence.

Validação da versão em português do Mini-Inventário de Fobia Social (Mini-SPIN) Validation of the portuguese version of the Mini-Social Phobia Inventory (Mini-SPIN)

OpenAIRE

Gustavo José Fonseca D'El Rey; Cláudia Wilmor Matos

2009-01-01

A fobia social (também conhecida como transtorno de ansiedade social) é um grave transtorno mental que traz sofrimento e incapacitação. O objetivo deste estudo foi validar para a língua portuguesa o Mini-Inventário de Fobia Social (Mini-SPIN) em uma amostra da população. Foi realizado um estudo da validade discriminativa do Mini-SPIN em uma amostra de 644 pessoas (grupo positivo para o Mini-SPIN: n = 218 e grupo controle/negativo: n = 426) de um estudo de prevalência de transtornos de ansieda...

Aromatic Plants as a Source of Bioactive Compounds

Directory of Open Access Journals (Sweden)

Panagiota Florou-Paneri

2012-09-01

Full Text Available Aromatic plants, also known as herbs and spices, have been used since antiquity as folk medicine and as preservatives in foods. The best known aromatic plants, such as oregano, rosemary, sage, anise, basil, etc., originate from the Mediterranean area. They contain many biologically active compounds, mainly polyphenolics, which have been found to possess antimicrobial, antioxidant, antiparasitic, antiprotozoal, antifungal, and anti-inflammatory properties. Currently, the demand for these plants and their derivatives has increased because they are natural, eco-friendly and generally recognized as safe products. Therefore, aromatic plants and their extracts have the potential to become new generation substances for human and animal nutrition and health. The purpose of this review is to provide an overview of the literature surrounding the in vivo and in vitro use of aromatic plants.

A review on polycyclic aromatic hydrocarbons: Source, environmental impact, effect on human health and

Directory of Open Access Journals (Sweden)

Hussein I. Abdel-Shafy

2016-03-01

The aim of this review is to discuss PAHs impact on the environmental and the magnitude of the human health risks posed by such substances. They also contain important information on concentrations, burdens and fate of polycyclic aromatic hydrocarbons (PAHs in the atmosphere. The main anthropogenic sources of PAHs and their effect on the concentrations of these compounds in air are discussed. The fate of PAHs in the air, their persistence and the main mechanisms of their losses are presented. Health hazards associated with PAH air pollution are stressed.

Chlorinated aliphatic and aromatic VOC decomposition in air mixture by using electron beam irradiation

International Nuclear Information System (INIS)

Chmielewski, A.G.; Sun Yongxia; Bulka, S.; Zimek, Z.

2004-01-01

Chlorinated aliphatic and aromatic hydrocarbons, which are emitted from coal power station and waste incinerators, are very harmful to the environment and human health. Recent studies show that chlorinated aliphatic and aromatic hydrocarbons are suspected to be the precursors of dioxin's formation. Dioxin's emission into atmosphere will cause severe environmental problems by ecology contamination. l,4-dichlorobenzene(l,4-DCB) and cis-dichloroethylene(cis-DCE) were chosen as representative chlorinated aromatic and aliphatic compounds, respectively. Their decomposition was investigated by electron beam irradiation. The experiments were carried out 'in batch' system. It is found that over 97% cis-DCE is decomposed having an initial concentration of 661 ppm. G-values of cis-DCE decomposition vary from 10 to 28 (molecules/100 eV) for initial concentration of 270-1530 ppm cis-DCE. The decomposition is mainly caused by secondary electron attachment and Cl addition reactions. Comparing with cis-DCE, 1,4-DCB decomposition needs higher absorbed dose. G-value of 1,4-DCB is below 4 molecules/100 eV

Spin-lattice relaxation in phosphorescent triplet state molecules

International Nuclear Information System (INIS)

Verbeek, P.J.F.

1979-01-01

The present thesis contains the results of a study of spin-lattice relaxation (SLR) in the photo-excited triplet state of aromatic molecules, dissolved in a molecular host crystal. It appears that SLR in phosphorescent triplet state molecules often is related to the presence of so-called (pseudo) localized phonons in the molecular mixed crystals. These local phonons can be thought to correspond with vibrations (librations) of the guest molecule in the force field of the surrounding host molecules. Since the intermolecular forces are relatively weak, the frequencies corresponding with these vibrations are relatively low and usually are of the order of 10-30 cm -1 . (Auth.)

Scrap automotive electronics: A mini-review of current management practices.

Science.gov (United States)

Cucchiella, Federica; D'Adamo, Idiano; Rosa, Paolo; Terzi, Sergio

2016-01-01

End-of-life vehicles, together with waste from electric and electronic equipment, are known as an important source of secondary raw materials. For many years, their recovery has allowed the restoring of great amounts of metals for new cars production. This article provides a comprehensive mini-review on the end-of-life vehicles recycling topic between 2000 and 2014, with a particular focus on automotive electronics recycling. In fact, in the last years, experts focused their attention on a better exploitation of automotive shredder residue fraction, but not sufficiently on eventual electronic scraps embedded in it. Hence, studies assessing the value embedded in these scraps are rarely available in literature, causing an important gap in both recycling policies and research. The fact that, at present, the management of electronic control units (the most valuable component among automotive electronic equipment) is, as yet, off the radar in both end-of-life vehicles and waste from electric and electronic equipment Directives demonstrates the theory. Of course, their recycling would not contribute in a relevant way to reach the weighted-based recycling and recovery targets characterising current regulations, but would be very important under a critical raw materials recovery view. Results coming from the literature analysis confirm these assumptions. © The Author(s) 2015.

MiniCNT - A Tabletop Stellarator

Science.gov (United States)

Dugan, Chris; Pedersen, Thomas; Berkery, John

2006-10-01

MiniCNT is a scaled down version of the Columbia Non-Neutral Torus, a stellarator built to study confinement of non-neutral plasmas on magnetic surfaces. MiniCNT is a glass vacuum chamber capable of holding pressures six orders of magnitude below atmospheric pressure. Unlike CNT, in which plasmas are invisible, MiniCNT allows some collisions with neutrals, causing it to glow. Using two twelve-volt car batteries to power four magnetic coils, MiniCNT generates a 0.02 Tesla magnetic field. While CNT, being larger, is obviously more accurate, there are multiple benefits in MiniCNT. First, it is more flexible and can be adjusted to fit many scenarios easily. The car batteries can be switched for other power sources, the coils can be realigned, and the chamber can be pumped to various pressures of various gases. Also, it is visually accessible; while CNT has glass viewing ports and its plasma is dark, MiniCNT is made of glass and its plasma glows, allowing visualization of the magnetic surfaces.

Mini-Cog and Mini-Mental State Examination: agreement in a cross-sectional study with an elderly sample.

Science.gov (United States)

Costa, Diogo; Severo, Milton; Fraga, Sílvia; Barros, Henrique

2012-01-01

We aimed to compare the Mini-Mental State Examination (MMSE) with the Mini-Cog, measuring agreement in participants' classification, using a general population sample. Cross-sectional evaluation of 609 community dwellers aged ≥60 years was performed by trained interviewers. Cohen's kappa and 95% confidence intervals (CI) were calculated to assess overall agreement, and Cronbach alphas computed to assess reliability. Two-parameter Item Response Theory models (difficulty and discrimination parameters) were used to assess discrimination. Considering MMSE cut-point for scores Mini-Cog's cut-point score Mini-Cog Mini-Cog Mini-Cog's alpha was 0.2776. Co-calibration according to inherent ability is graphically presented. Agreement between scales seems fragile in our sample. The discriminative and reliability analysis suggests a better performance for subsets of the MMSE compared with the Mini-Cog. Usefulness of calibrated scores is discussed. Copyright © 2012 S. Karger AG, Basel.

Aromatics saturation, opening and cleavage technology for middle distillates

Energy Technology Data Exchange (ETDEWEB)

Oballa, M.C.; Simanzhenkov, V.; Kim, G. [NOVA Chemicals Corp., Calgary, AB (Canada)

2009-07-01

In order to address environmental concerns, there is a need to develop technologies to reformulate or adjust the quality of transportation fuels. The purpose is to reduce the concentration of the compounds which negatively affect the air that people breathe. One of those targeted is the aromatics content of diesel, because high aromatics content results in low cetane number of diesel, as well as higher emission of particulate matter. Less conventional sources of hydrocarbon feedstock such as oil from oil sands and/or shale oil are being exploited in Alberta. These feeds contain multiple fused aromatic ring compounds. NOVA Chemicals would like to use these potentially abundant liquids as feed, but they must first be transformed into a more user friendly state. This paper discussed the development of a process technology that could saturate the aromatic rings, open up the saturated rings and cleave them to get smaller paraffinic molecules. The products then comprised of lower paraffins are suitable as feed to steam crackers for the production of ethylene and propylene, higher paraffins suitable for blending into gasoline and mono aromatic ring compounds which may be further treated through alkylation of benzene to ethylbenzene and dealkylation to styrene. The paper discussed the process steps and highlighted the catalysts. Research results were also shown. It was concluded that the critical technology gaps, as well as solutions, which would enable overcoming the challenges related to handling of aromatic bitumen feedstock, entail the development of two different catalysts, which are on two different technology platforms. 7 refs., 3 tabs., 5 figs.

MiniDraw

DEFF Research Database (Denmark)

2018-01-01

MiniDraw is a teaching-oriented 2D graphics direct manipulation framework in Java, inspired by JHotDraw. It is used in the book "Flexible, Reliable Software - using Patterns and Agile Development", by Henrik Bærbak Christensen, published by CRC Press 2010.......MiniDraw is a teaching-oriented 2D graphics direct manipulation framework in Java, inspired by JHotDraw. It is used in the book "Flexible, Reliable Software - using Patterns and Agile Development", by Henrik Bærbak Christensen, published by CRC Press 2010....

Mini-grid Policy Tool-kit. Policy and business frameworks for successful mini-grid roll-outs

International Nuclear Information System (INIS)

Franz, Michael; Hayek, Niklas; Peterschmidt, Nico; Rohrer, Michael; Kondev, Bozhil; Adib, Rana; Cader, Catherina; Carter, Andrew; George, Peter; Gichungi, Henry; Hankins, Mark; Kappiah, Mahama; Mangwengwende, Simbarashe E.

2014-01-01

The Mini-grid Policy Tool-kit is for policy makers to navigate the mini-grid policy design process. It contains information on mini-grid operator models, the economics of mini-grids, and necessary policy and regulation that must be considered for successful implementation. The publication specifically focuses on Africa. Progress on extending the electricity grid in many countries has remained slow because of high costs of gird-extension and limited utility/state budgets for electrification. Mini-grids provide an affordable and cost-effective option to extend needed electricity services. Putting in place the right policy for min-grid deployment requires considerable effort but can yield significant improvement in electricity access rates as examples from Kenya, Senegal and Tanzania illustrate. The tool-kit is available in English, French and Portuguese

Perceptual Learning as a potential treatment for amblyopia: a mini-review

Science.gov (United States)

Levi, Dennis M.; Li, Roger W.

2009-01-01

Amblyopia is a developmental abnormality that results from physiological alterations in the visual cortex and impairs form vision. It is a consequence of abnormal binocular visual experience during the “sensitive period” early in life. While amblyopia can often be reversed when treated early, conventional treatment is generally not undertaken in older children and adults. A number of studies over the last twelve years or so suggest that Perceptual Learning (PL) may provide an important new method for treating amblyopia. The aim of this mini-review is to provide a critical review and “meta-analysis” of perceptual learning in adults and children with amblyopia, with a view to extracting principles that might make PL more effective and efficient. Specifically we evaluate: What factors influence the outcome of perceptual learning?Specificity and generalization – two sides of the coin.Do the improvements last?How does PL improve visual function?Should PL be part of the treatment armamentarium? A review of the extant studies makes it clear that practicing a visual task results in a long-lasting improvement in performance in an amblyopic eye. The improvement is generally strongest for the trained eye, task, stimulus and orientation, but appears to have a broader spatial frequency bandwidth than in normal vision. Importantly, practicing on a variety of different tasks and stimuli seems to transfer to improved visual acuity. Perceptual learning operates via a reduction of internal neural noise and/or through more efficient use of the stimulus information by retuning the weighting of the information. The success of PL raises the question of whether it should become a standard part of the armamentarium for the clinical treatment of amblyopia, and suggests several important principles for effective perceptual learning in amblyopia. PMID:19250947

Structure, aromaticity and reactivity of corannulene and its analogues: a conceptual density functional theory and density functional reactivity theory study

Science.gov (United States)

Deng, Youer; Yu, Donghai; Cao, Xiaofang; Liu, Lianghong; Rong, Chunying; Lu, Tian; Liu, Shubin

2018-04-01

Corannulene is an interesting yet special molecule, which has witnessed widespread applications. It is aromatic, but not planar and the total number of 20 π electrons is in conflict with Hückel's 4n + 2 rule. In this work, we design a series of analogous model systems based on this molecule with the central ring size extended from five members to three to eight members. A number of theoretical and analytical tools available in the literature are employed to systematically examine their structure, aromaticity and reactivity properties. We found that structurally speaking, they change from bowl-like to planar and then to saddle shapes as the central ring size increases from three to eight. From the reactivity perspective, species with five and six-membered-rings in the centre are chemically more stable and less reactive, which are confirmed by the numerical results from aromaticity indexes and quantities from the information-theoretic approach. Overall, our results show that only corannulene and its six-membered-ring, coronene, analogue are aromatic. Even though these two systems are aromatic in nature, they are markedly different in a number of ways in structure, reactivity and other properties. These results should provide with us insights and understanding about the phenomenon of three-dimensional and non-planarity aromaticity.

Genomic and metagenomic challenges and opportunities for bioleaching: a mini-review.

Science.gov (United States)

Cárdenas, Juan Pablo; Quatrini, Raquel; Holmes, David S

2016-09-01

High-throughput genomic technologies are accelerating progress in understanding the diversity of microbial life in many environments. Here we highlight advances in genomics and metagenomics of microorganisms from bioleaching heaps and related acidic mining environments. Bioleaching heaps used for copper recovery provide significant opportunities to study the processes and mechanisms underlying microbial successions and the influence of community composition on ecosystem functioning. Obtaining quantitative and process-level knowledge of these dynamics is pivotal for understanding how microorganisms contribute to the solubilization of copper for industrial recovery. Advances in DNA sequencing technology provide unprecedented opportunities to obtain information about the genomes of bioleaching microorganisms, allowing predictive models of metabolic potential and ecosystem-level interactions to be constructed. These approaches are enabling predictive phenotyping of organisms many of which are recalcitrant to genetic approaches or are unculturable. This mini-review describes current bioleaching genomic and metagenomic projects and addresses the use of genome information to: (i) build metabolic models; (ii) predict microbial interactions; (iii) estimate genetic diversity; and (iv) study microbial evolution. Key challenges and perspectives of bioleaching genomics/metagenomics are addressed. Copyright © 2016 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.

Psychometric properties of a sign language version of the Mini International Neuropsychiatric Interview (MINI)

OpenAIRE

Øhre, Beate; Saltnes, Hege; von Tetzchner, Stephen; Falkum, Erik

2014-01-01

Background There is a need for psychiatric assessment instruments that enable reliable diagnoses in persons with hearing loss who have sign language as their primary language. The objective of this study was to assess the validity of the Norwegian Sign Language (NSL) version of the Mini International Neuropsychiatric Interview (MINI). Methods The MINI was translated into NSL. Forty-one signing patients consecutively referred to two specialised psychiatric units were assessed with a diagnos...

The effects of polycyclic aromatic hydrocarbons on the chemistry of photodissociation regions

NARCIS (Netherlands)

Bakes, ELO; Tielens, AGGM

1998-01-01

We have investigated the effects of including polycylic aromatic hydrocarbons (PAHs) on the abundance of neutral atoms and molecules for two typical photodissociation regions (PDRs): a high-density case (the Orion complex) and a low-density case. PAHs provide a large surface area for chemistry

iPad mini for dummies

CERN Document Server

Baig, Edward C

2014-01-01

Find out why the iPad mini has never been bigger This new edition of iPad mini For Dummies covers all the latest tips and tricks for getting an even bigger bang out of your iPad mini. Presented in full-color and written in the straightforward but fun language that has defined the For Dummies brand for more than twenty years, this friendly guide walks you through the multitouch interface, going online, getting connected, packing your iPad mini with apps, games, e-books, photos, music, and movies, synchronizing your data, texting with iMessage, working with Siri, importing pictures and launching

Computer-based quantitative computed tomography image analysis in idiopathic pulmonary fibrosis: A mini review.

Science.gov (United States)

Ohkubo, Hirotsugu; Nakagawa, Hiroaki; Niimi, Akio

2018-01-01

Idiopathic pulmonary fibrosis (IPF) is the most common type of progressive idiopathic interstitial pneumonia in adults. Many computer-based image analysis methods of chest computed tomography (CT) used in patients with IPF include the mean CT value of the whole lungs, density histogram analysis, density mask technique, and texture classification methods. Most of these methods offer good assessment of pulmonary functions, disease progression, and mortality. Each method has merits that can be used in clinical practice. One of the texture classification methods is reported to be superior to visual CT scoring by radiologist for correlation with pulmonary function and prediction of mortality. In this mini review, we summarize the current literature on computer-based CT image analysis of IPF and discuss its limitations and several future directions. Copyright © 2017 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

Validação da versão em português do Mini-Inventário de Fobia Social (Mini-SPIN Validation of the portuguese version of the Mini-Social Phobia Inventory (Mini-SPIN

Directory of Open Access Journals (Sweden)

Gustavo José Fonseca D'El Rey

2009-12-01

Full Text Available A fobia social (também conhecida como transtorno de ansiedade social é um grave transtorno mental que traz sofrimento e incapacitação. O objetivo deste estudo foi validar para a língua portuguesa o Mini-Inventário de Fobia Social (Mini-SPIN em uma amostra da população. Foi realizado um estudo da validade discriminativa do Mini-SPIN em uma amostra de 644 pessoas (grupo positivo para o Mini-SPIN: n = 218 e grupo controle/negativo: n = 426 de um estudo de prevalência de transtornos de ansiedade na cidade de Santo André (SP. A versão em português do Mini-SPIN (com escore de 6 pontos, sugerido na versão original em inglês demonstrou uma sensibilidade de 95,0%, especificidade de 80,3%, valor preditivo positivo de 52,8%, valor preditivo negativo de 98,6% e taxa de classificação incorreta de 16,9%. Com escores de 7 pontos, foi observado um aumento na especificidade e no valor preditivo positivo (88,6% e 62,7%, sendo que a sensibilidade e o valor preditivo negativo (84,8% e 96,2% mantiveram-se altos. A versão em português do Mini-SPIN apresentou qualidades psicométricas satisfatórias em termos de validade discriminativa. Neste estudo, o ponto de corte igual a 7 mostrou-se mais adequado para a identificação da fobia social generalizada.Social phobia (also known as social anxiety disorder is a severe mental disorder that brings distress and disability. The aim of this study was validate to the Portuguese language the Mini-Social Phobia Inventory (Mini-SPIN in a populational sample. We performed a discriminative validity study of the Mini-SPIN in a sample of 644 subjects (Mini-SPIN positive group: n = 218 and control/negative group: n = 426 of a study of anxiety disorders' prevalence in the city of Santo André-SP. The Portuguese version of the Mini-SPIN (with score of 6 points, suggested in the original English version demonstrated a sensitivity of 95.0%, specificity of 80.3%, positive predictive value of 52.8%, negative predictive

Polycyclic Aromatic Compounds as Anticancer Agents: Synthesis and Biological Evaluation of Methoxy Dibenzofluorene Derivatives

Directory of Open Access Journals (Sweden)

Bimal Krishna Banik

2014-08-01

Full Text Available Synthesis of a new methoxy dibenzofluorene through alkylation, cyclodehydration and aromatization in a one-pot operation is achieved for the first time. Using this hydrocarbon, a few derivatives are prepared through aromatic nitration, catalytic hydrogenation, coupling reaction with a side chain and reduction. The benzylic position of this hydrocarbon with the side chain is oxidized and reduced. Some of these derivatives have demonstrated excellent antitumor activities in vitro. This study confirms antitumor activity depends on the structures of the molecules.

Senescence-Derived Extracellular Molecules as Modulators of Oral Cancer Development: A Mini-Review.

Science.gov (United States)

Parkinson, Eric Kenneth; James, Emma L; Prime, Stephen S

2016-01-01

Oral cancers are predominantly oral squamous cell carcinomas (OSCCs) derived from keratinocytes, and there is now very detailed knowledge of the genetics and molecular biology of the epithelial tumourigenic component of these cancers, including the identification of cancer stem or tumour-initiating cells. Several key genetic alterations have been identified including the near ubiquitous loss of the CDKN2A/p16INK4A and p53 pathways and telomerase activation, together with frequent inactivation of the NOTCH1 canonical pathway either by somatic genetic alterations or by the presence of human papilloma virus. There is also evidence that OSCCs arise from a 'field' of altered cells and that malignant conversion takes place pre-dominantly at the microscopic level. However, in the last decade, it has been realised that tumour development and progression are influenced by the cells of the microenvironment with cross-talk between the epithelial (tumour) and mesenchymal components. OSCCs, especially those that have bypassed cellular senescence, produce an array of proteins and metabolites that induce cellular senescence in the normal surrounding cells; indeed, senescence is a common property of cancer-associated fibroblasts (CAFs). Cellular senescence is defined as an irreversible cell cycle arrest and is associated with the release of molecules known as the senescence-associated secretory phenotype that can selectively promote the growth of pre-neoplastic keratinocytes (osteopontin) and cancer invasion (transforming growth factor β, matrix metalloproteinases, interleukin 6 and lactate). In addition, both old and new work has shown that keratinocytes harbouring NOTCH loss-of-function mutations that lead to defective keratinocyte differentiation and loss of squamous epithelial barrier function may act as a tumour-promoting stimulus for initiated cells harbouring RAS pathway mutations by activating a wound response in the tumour mesenchyme. Thus, not all keratinocytes in the

TOPICAL REVIEW: Single-molecule experiments in biological physics: methods and applications

Science.gov (United States)

Ritort, F.

2006-08-01

I review single-molecule experiments (SMEs) in biological physics. Recent technological developments have provided the tools to design and build scientific instruments of high enough sensitivity and precision to manipulate and visualize individual molecules and measure microscopic forces. Using SMEs it is possible to manipulate molecules one at a time and measure distributions describing molecular properties, characterize the kinetics of biomolecular reactions and detect molecular intermediates. SMEs provide additional information about thermodynamics and kinetics of biomolecular processes. This complements information obtained in traditional bulk assays. In SMEs it is also possible to measure small energies and detect large Brownian deviations in biomolecular reactions, thereby offering new methods and systems to scrutinize the basic foundations of statistical mechanics. This review is written at a very introductory level, emphasizing the importance of SMEs to scientists interested in knowing the common playground of ideas and the interdisciplinary topics accessible by these techniques. The review discusses SMEs from an experimental perspective, first exposing the most common experimental methodologies and later presenting various molecular systems where such techniques have been applied. I briefly discuss experimental techniques such as atomic-force microscopy (AFM), laser optical tweezers (LOTs), magnetic tweezers (MTs), biomembrane force probes (BFPs) and single-molecule fluorescence (SMF). I then present several applications of SME to the study of nucleic acids (DNA, RNA and DNA condensation) and proteins (protein-protein interactions, protein folding and molecular motors). Finally, I discuss applications of SMEs to the study of the nonequilibrium thermodynamics of small systems and the experimental verification of fluctuation theorems. I conclude with a discussion of open questions and future perspectives.

Spurious RF signals emitted by mini-UAVs

NARCIS (Netherlands)

Schleijpen, R.; Voogt, V.; Zwamborn, P.; Oever, J. van den

2016-01-01

This paper presents experimental work on the detection of spurious RF emissions of mini Unmanned Aerial Vehicles (mini-UAV). Many recent events have shown that mini-UAVs can be considered as a potential threat for civil security. For this reason the detection of mini-UAVs has become of interest to

Near Infrared Spectroscopic Identification of Alkyl Aromatic Esters and Phenyl Ketones

Science.gov (United States)

Nelyubov, D. V.; Vazhenin, D. A.; Kudriavtsev, A. A.; Buzolina, A. Yu.

2018-03-01

Bands characterizing the content of carbon atoms in alkyl (7177-7205 cm-1) and phenyl structural fragments (9175-9192 cm-1) in organic molecules were revealed by studying the near infrared spectra of such compounds. The optical density at the maxima of these absorption bands was shown to depend strongly on the fraction of carbon atoms in the corresponding fragments. The developed models proved to be adequate for determining the fraction of carbon atoms in alkyl aromatic esters and phenyl ketones. The feasibility of modeling the molecular structure of alkyl aromatic esters using regression models was demonstrated for the product of the condensation of oleic acid and benzyl alcohol.

A mini review of designed mesoporous materials for energy-storage applications: from electric double-layer capacitors to hybrid supercapacitors

Science.gov (United States)

Lim, Eunho; Jo, Changshin; Lee, Jinwoo

2016-04-01

In recent years, porous materials have attracted significant attention in various research fields because of their structural merits. In particular, well-designed mesoporous structures with two- or three-dimensionally interconnected pores have been recognized as electrode materials of particular interest for achieving high-performance electrochemical capacitors (ECs). In this mini review, recent progress in the design of mesoporous electrode materials for ECs, from electric double-layer capacitors (EDLCs) and pseudocapacitors (PCs) to hybrid supercapacitors (HSCs), and research challenges for the development of new mesoporous electrode materials has been discussed.

Fused aromatic thienopyrazines: structure, properties and function

KAUST Repository

Mondal, Rajib

2010-01-01

Recent development of a fused aromatic thieno[3.4-b]pyrazine system and their application in optoelectronic devices are reviewed. Introduction of a fused aromatic unit followed by side chain engineering, dramatically enhanced the charge carrier mobility in thin film transistor devices and mobilities up to 0.2 cm2/Vs were achieved. The optoelectronic properties of these fused aromatic thienopyrazine polymers (Eg = 1.3 to 1.6 eV, HOMO = -4.9 to -5.2 V) were tuned by introduction of various fused aromatic rings within thienopyrazine. By balancing the fundamental properties of these polymers, both high charge carrier mobilities and moderate PCEs in solar cells were achieved. Further, effects of copolymerizing units are discussed. Low band gap semiconducting polymer (Eg ∼ 1 eV) with high field effect mobility (0.044 cm2/Vs) was obtained using cyclopentadithiophene as copolymerizing unit. Finally, a molecular design approach to enhance the absorption coefficients is discussed, which resulted in improved power conversion efficiency in bulk heterojunction solar cells. © 2010 The Royal Society of Chemistry.

Influence of methoxy- and nitro-substitutions in the aromatic ring on proton donation ability in hydrogen bond and on the amino group parameters of free and H-bonded molecules of 2-aminopyrimidine

Science.gov (United States)

Borisenko, V. E.; Krekov, S. A.; Fomenko, M. Yu.; Koll, A.; Lipkovski, P.

2008-06-01

Amino- and imino- forms of pyrimidine are widely presented as part of antibiotics, corrective medications for heart failures and metabolic stimulators. Hydrogen bonding is one of the fundamental interactions between biologically active molecules. This type of interactions provides flexibility, speed and variety of the biochemical processes. Proton donation properties of aminopyrimidines significantly depend on the position, number and kind of the substituent in its aromatic ring. In present work we studied the influence of the methoxy- and nitro-substitutions in the phenyl radical of pyridine and pyrimidine cycles on the proton donation ability of the amino group in hydrogen bonds as well as on its geometrical, force, electro-optical and thermodynamical characteristics in free and H-bonded (1:1 and 1:2, with various proton acceptors) molecules of primary aromatic amines. Acetonitrile, dioxane, tetrahydrofourane, dimethylformamide, dimethylsulfoxide and hexamethylphosphoramide (whose proton accepting properties vary within a wide range) were used as proton acceptors in our research. In the region of the amino group stretching and deformation vibrations the IR spectra of free and H-bonded (1:1) molecules of 2-amino-4,6-dimethoxy- and 2-amino-5-nitropyrimidine were studied in complexes with proton acceptors in CCl 4 within the temperature range 288-328 K. The spectra of 1:2 complexes were studied in undiluted aprotic solvents. The following spectral characteristics of absorption bands in amino group stretching vibrations were determined: M(0) (zero spectral moment, integrated intensity B); M(1) (first spectral moment, band "centre of gravity"); effective half width, related to the second central moment (Δ ν1/2) eff = 2( M(2)) 1/2, frequencies of the deformation vibrations δ(HNH) of free and H-bonded molecules. It was shown that changes of the absorption band spectral characteristics of the amino group stretching and deformation vibrations in the analyzed

Psychometric Evaluation of the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID).

Science.gov (United States)

Duncan, Laura; Georgiades, Kathy; Wang, Li; Van Lieshout, Ryan J; MacMillan, Harriet L; Ferro, Mark A; Lipman, Ellen L; Szatmari, Peter; Bennett, Kathryn; Kata, Anna; Janus, Magdalena; Boyle, Michael H

2017-12-04

The goals of the study were to examine test-retest reliability, informant agreement and convergent and discriminant validity of nine DSM-IV-TR psychiatric disorders classified by parent and youth versions of the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID). Using samples drawn from the general population and child mental health outpatient clinics, 283 youth aged 9 to 18 years and their parents separately completed the MINI-KID with trained lay interviewers on two occasions 7 to 14 days apart. Test-retest reliability estimates based on kappa (κ) went from 0.33 to 0.79 across disorders, samples and informants. Parent-youth agreement on disorders was low (average κ = 0.20). Confirmatory factor analysis provided evidence supporting convergent and discriminant validity. The MINI-KID disorder classifications yielded estimates of test-retest reliability and validity comparable to other standardized diagnostic interviews in both general population and clinic samples. These findings, in addition to the brevity and low administration cost, make the MINI-KID a good candidate for use in epidemiological research and clinical practice. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Applications of electrochemically-modulated liquid chromatography (EMLC): Separations of aromatic amino acids and polycyclic aromatic hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Deng, Li [Iowa State Univ., Ames, IA (United States)

1998-03-27

The research in this thesis explores the separation capabilities of a new technique termed electrochemically-modulated liquid chromatography (EMLC). The thesis begins with a general introduction section which provides a literature review of this technique as well as a brief background discussion of the two research projects in each of the next two chapters. The two papers which follow investigate the application of EMLC to the separation of a mixture of aromatic amino acids and of a mixture of polycyclic aromatic hydrocarbons (PAHs). The last section presents general conclusions and summarizes the thesis. References are compiled in the reference section of each chapter. The two papers have been removed for separate processing.

The MiniBooNE Detector

OpenAIRE

MiniBooNE Collaboration

2008-01-01

The MiniBooNE neutrino detector was designed and built to look for muon-neutrino to electron-neutrino oscillations in the mixing parameter space region where the LSND experiment reported a signal. The MiniBooNE experiment used a beam energy and baseline that were an order of magnitude larger than those of LSND so that the backgrounds and systematic errors would be completely different. This paper provides a detailed description of the design, function, and performance of the MiniBooNE detector.

Alternate service delivery models in cancer genetic counseling: a mini-review

Directory of Open Access Journals (Sweden)

Adam Hudson Buchanan

2016-05-01

Full Text Available Demand for cancer genetic counseling has grown rapidly in recent years as germline genomic information has become increasingly incorporated into cancer care and the field has entered the public consciousness through high-profile celebrity publications. Increased demand and existing variability in the availability of trained cancer genetics clinicians place a priority on developing and evaluating alternate service delivery models for genetic counseling. This mini-review summarizes the state of science regarding service delivery models such as telephone counseling, telegenetics and group counseling. Research on comparative effectiveness of these models in traditional individual, in-person genetic counseling has been promising for improving access to care in a manner acceptable to patients. Yet, it has not fully evaluated the short- and long-term patient- and system-level outcomes that will help answer the question of whether these models achieve the same beneficial psychosocial and behavioral outcomes as traditional cancer genetic counseling. We propose a research agenda focused on comparative effectiveness of available service delivery models and how to match models to patients and practice settings. Only through this rigorous research can clinicians and systems find the optimal balance of clinical quality, ready and secure access to care, and financial sustainability. Such research will be integral to achieving the promise of genomic medicine in oncology.

Metabolism and Biomarkers of Heterocyclic Aromatic Amines in Molecular Epidemiology Studies: Lessons Learned from Aromatic Amines

Science.gov (United States)

2011-01-01

Aromatic amines and heterocyclic aromatic amines (HAAs) are structurally related classes of carcinogens that are formed during the combustion of tobacco or during the high-temperature cooking of meats. Both classes of procarcinogens undergo metabolic activation by N-hydroxylation of the exocyclic amine group, to produce a common proposed intermediate, the arylnitrenium ion, which is the critical metabolite implicated in toxicity and DNA damage. However, the biochemistry and chemical properties of these compounds are distinct and different biomarkers of aromatic amines and HAAs have been developed for human biomonitoring studies. Hemoglobin adducts have been extensively used as biomarkers to monitor occupational and environmental exposures to a number of aromatic amines; however, HAAs do not form hemoglobin adducts at appreciable levels and other biomarkers have been sought. A number of epidemiologic studies that have investigated dietary consumption of well-done meat in relation to various tumor sites reported a positive association between cancer risk and well-done meat consumption, although some studies have shown no associations between well-done meat and cancer risk. A major limiting factor in most epidemiological studies is the uncertainty in quantitative estimates of chronic exposure to HAAs and, thus, the association of HAAs formed in cooked meat and cancer risk has been difficult to establish. There is a critical need to establish long-term biomarkers of HAAs that can be implemented in molecular epidemioIogy studies. In this review article, we highlight and contrast the biochemistry of several prototypical carcinogenic aromatic amines and HAAs to which humans are chronically exposed. The biochemical properties and the impact of polymorphisms of the major xenobiotic-metabolizing enzymes on the biological effects of these chemicals are examined. Lastly, the analytical approaches that have been successfully employed to biomonitor aromatic amines and HAAs, and

A DNA mini-barcode for land plants.

Science.gov (United States)

Little, Damon P

2014-05-01

Small portions of the barcode region - mini-barcodes - may be used in place of full-length barcodes to overcome DNA degradation for samples with poor DNA preservation. 591,491,286 rbcL mini-barcode primer combinations were electronically evaluated for PCR universality, and two novel highly universal sets of priming sites were identified. Novel and published rbcL mini-barcode primers were evaluated for PCR amplification [determined with a validated electronic simulation (n = 2765) and empirically (n = 188)], Sanger sequence quality [determined empirically (n = 188)], and taxonomic discrimination [determined empirically (n = 30,472)]. PCR amplification for all mini-barcodes, as estimated by validated electronic simulation, was successful for 90.2-99.8% of species. Overall Sanger sequence quality for mini-barcodes was very low - the best mini-barcode tested produced sequences of adequate quality (B20 ≥ 0.5) for 74.5% of samples. The majority of mini-barcodes provide correct identifications of families in excess of 70.1% of the time. Discriminatory power noticeably decreased at lower taxonomic levels. At the species level, the discriminatory power of the best mini-barcode was less than 38.2%. For samples believed to contain DNA from only one species, an investigator should attempt to sequence, in decreasing order of utility and probability of success, mini-barcodes F (rbcL1/rbcLB), D (F52/R193) and K (F517/R604). For samples believed to contain DNA from more than one species, an investigator should amplify and sequence mini-barcode D (F52/R193). © 2013 John Wiley & Sons Ltd.

Cutting edge pre-intermediate : student's book : with mini-dictionary

CERN Document Server

Cunningham, Sarah; Comyns Carr, Jane

2001-01-01

A focus on high-frequency useful vocabulary helps students say what they want to say. Regular, well-structured speaking tasks encourage students to express themselves more extensively and fluently. ‘Do You Remember’ sections in every unit and extra. Consolidation modules provide regular review and consolidation Student Books include Mini-Dictionary to help learners study independently.

Non-covalent Interactions of Graphene with Polycyclic Aromatic Hydrocarbons

NARCIS (Netherlands)

Zygouri, Panagiota; Potsi, Georgia; Mouzourakis, Eleftherios; Spyrou, Konstantinos; Gournis, Dimitrios; Rudolf, Petra

2015-01-01

In this mini review we discuss the interactions of polyaromatic hydrocarbons (PAHs) with graphene and the experimental approaches developed so far to create novel graphene/PAH hybrids and composite systems. The utilization of these systems in electrical, biomedical and polymer-reinforcement

Polycyclic Aromatic Hydrocarbons Adsorption onto Graphene: A DFT and AIMD Study

Directory of Open Access Journals (Sweden)

Bing Li

2018-05-01

Full Text Available Density functional theory (DFT calculations and ab-initio molecular dynamics (AIMD simulations were performed to understand graphene and its interaction with polycyclic aromatic hydrocarbons (PAHs molecules. The adsorption energy was predicted to increase with the number of aromatic rings in the adsorbates, and linearly correlate with the hydrophobicity of PAHs. Additionally, the analysis of the electronic properties showed that PAHs behave as mild n-dopants and introduce electrons into graphene; but do not remarkably modify the band gap of graphene, indicating that the interaction between PAHs and graphene is physisorption. We have also discovered highly sensitive strain dependence on the adsorption strength of PAHs onto graphene surface. The AIMD simulation indicated that a sensitive and fast adsorption process of PAHs can be achieved by choosing graphene as the adsorbent. These findings are anticipated to shed light on the future development of graphene-based materials with potential applications in the capture and removal of persistent aromatic pollutants.

Environmental Temperature Effect on the Far-Infrared Absorption Features of Aromatic-Based Titan's Aerosol Analogs

Science.gov (United States)

Gautier, Thomas; Trainer, Melissa G.; Loeffler, Mark J.; Sebree, Joshua A.; Anderson, Carrie M.

2016-01-01

Benzene detection has been reported in Titans atmosphere both in the stratosphere at ppb levels by remote sensing and in the thermosphere at ppm levels by the Cassini's Ion and Neutral Mass Spectrometer. This detection supports the idea that aromatic and heteroaromatic reaction pathways may play an important role in Titans atmospheric chemistry, especially in the formation of aerosols. Indeed, aromatic molecules are easily dissociated by ultraviolet radiation and can therefore contribute significantly to aerosol formation. It has been shown recently that aerosol analogs produced from a gas mixture containing a low concentration of aromatic and/or heteroaromatic molecules (benzene, naphthalene, pyridine, quinoline and isoquinoline) have spectral signatures below 500/cm, a first step towards reproducing the aerosol spectral features observed by Cassini's Composite InfraRed Spectrometer (CIRS) in the far infrared. In this work we investigate the influence of environmental temperature on the absorption spectra of such aerosol samples, simulating the temperature range to which aerosols, once formed, are exposed during their transport through Titans stratosphere. Our results show that environmental temperature does not have any major effect on the spectral shape of these aerosol analogs in the far-infrared, which is consistent with the CIRS observations.

Mini-review: In vitro Metabolic Engineering for Biomanufacturing of High-value Products

Directory of Open Access Journals (Sweden)

Weihua Guo

Full Text Available With the breakthroughs in biomolecular engineering and synthetic biology, many valuable biologically active compound and commodity chemicals have been successfully manufactured using cell-based approaches in the past decade. However, because of the high complexity of cell metabolism, the identification and optimization of rate-limiting metabolic pathways for improving the product yield is often difficult, which represents a significant and unavoidable barrier of traditional in vivo metabolic engineering. Recently, some in vitro engineering approaches were proposed as alternative strategies to solve this problem. In brief, by reconstituting a biosynthetic pathway in a cell-free environment with the supplement of cofactors and substrates, the performance of each biosynthetic pathway could be evaluated and optimized systematically. Several value-added products, including chemicals, nutraceuticals, and drug precursors, have been biosynthesized as proof-of-concept demonstrations of in vitro metabolic engineering. This mini-review summarizes the recent progresses on the emerging topic of in vitro metabolic engineering and comments on the potential application of cell-free technology to speed up the “design-build-test” cycles of biomanufacturing. Keywords: Cell-free, Biosynthesis, Metabolic pathways, Design-build-test cycle

The MiniBooNE detector

International Nuclear Information System (INIS)

Aguilar-Arevalo, A.A.; Anderson, C.E.; Bartoszek, L.M.; Bazarko, A.O.; Brice, S.J.; Brown, B.C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J.M.; Cox, D.C.; Curioni, A.; Djurcic, Z.; Finley, D.A.; Fleming, B.T.; Ford, R.; Garcia, F.G.; Garvey, G.T.; Green, C.; Green, J.A.

2009-01-01

The MiniBooNE neutrino detector was designed and built to look for ν μ →ν e oscillations in the (sin 2 2θ,Δm 2 ) parameter space region where the LSND experiment reported a signal. The MiniBooNE experiment used a beam energy and baseline that were an order of magnitude larger than those of LSND so that the backgrounds and systematic errors would be completely different. This paper provides a detailed description of the design, function, and performance of the MiniBooNE detector.

Are Ducted Mini-Splits Worth It?

Energy Technology Data Exchange (ETDEWEB)

Winkler, Jonathan M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Maguire, Jeffrey B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Metzger, Cheryn E. [Pacific Northwest National Laboratory; Zhang, Jason [Pacific Northwest National Laboratory

2018-02-01

Ducted mini-split heat pumps are gaining popularity in some regions of the country due to their energy-efficient specifications and their ability to be hidden from sight. Although product and install costs are typically higher than the ductless mini-split heat pumps, this technology is well worth the premium for some homeowners who do not like to see an indoor unit in their living area. Due to the interest in this technology by local utilities and homeowners, the Bonneville Power Administration (BPA) has funded the Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy Laboratory (NREL) to develop capabilities within the Building Energy Optimization (BEopt) tool to model ducted mini-split heat pumps. After the fundamental capabilities were added, energy-use results could be compared to other technologies that were already in BEopt, such as zonal electric resistance heat, central air source heat pumps, and ductless mini-split heat pumps. Each of these technologies was then compared using five prototype configurations in three different BPA heating zones to determine how the ducted mini-split technology would perform under different scenarios. The result of this project was a set of EnergyPlus models representing the various prototype configurations in each climate zone. Overall, the ducted mini-split heat pumps saved about 33-60% compared to zonal electric resistance heat (with window AC systems modeled in the summer). The results also showed that the ducted mini-split systems used about 4% more energy than the ductless mini-split systems, which saved about 37-64% compared to electric zonal heat (depending on the prototype and climate).

Protecting the radiation-damaged skin from friction: a mini review

International Nuclear Information System (INIS)

Herst, Patries M

2014-01-01

Radiation-induced skin reactions are an unavoidable side effect of external beam radiation therapy, particularly in areas prone to friction and excess moisture such as the axilla, head and neck region, perineum and skin folds. Clinical studies investigating interventions for preventing or managing these reactions have largely focussed on formulations with moisturising, anti-inflammatory, anti-microbial and wound healing properties. However, none of these interventions has emerged as a consistent candidate for best practice. Much less emphasis has been placed on evaluating ways to protect the radiation-damaged skin from friction and excess moisture. This mini review analyses the clinical evidence for barrier products that form a protective layer by adhering very closely to the skin folds and do not cause further trauma to the radiation-damaged skin upon removal. A database search identified only two types of barrier products that fitted these criteria and these were tested in two case series and six controlled clinical trials. Friction protection was most effective when the interventions were used from the start of treatment and continued for several weeks after completion of treatment. Soft silicone dressings (Mepilex Lite and Mepitel Film) and Cavilon No Sting Barrier Film, but not Cavilon Moisturizing Barrier Cream, decreased skin reaction severity, most likely due to differences in formulation and skin build-up properties. It seems that prophylactic use of friction protection of areas at risk could be a worthwhile addition to routine care of radiation-damaged skin

Review: Biological fertilization and its effect on medicinal and aromatic plants

Directory of Open Access Journals (Sweden)

KHALID ALI KHALID

2012-11-01

Full Text Available Khalid KA. 2012. Review: Biological fertilization and its effect on medicinal and aromatic plants. Nusantara Bioscience 4: 124-133. The need of increase food production in the most of developing countries becomes an ultimate goal to meet the dramatic expansion of their population. However, this is also associated many cases with a reduction of the areas of arable land which leaves no opinion for farmers but to increase the yield per unit area through the use of improved the crop varieties, irrigation and fertilization. The major problem facing the farmer is that he cannot afford the cost of these goods, particularly that of chemical fertilizers. Moreover, in countries where fertilizer production relies on imported raw materials, the costs are even higher for farmer and for the country. Besides this, chemical fertilizers production and utilization are considered as air, soil and water polluting operations. The utilization of bio-fertilizers is considered today by many scientists as a promising alternative, particularly for developing countries. Bio-fertilization is generally based on altering the rhizosphere flora, by seed or soil inoculation with certain organisms, capable of inducing beneficial effects on a compatible host. Bio-fertilizers mainly comprise nitrogen fixes (Rhizobium, Azotobacter, Azospirellum, Azolla or blue green algae, phosphate dissolvers or vesicular-arbuscular mycorrhizas and silicate bacteria. These organisms may affect their host plant by one or more mechanisms such as nitrogen fixation, production of growth promoting substances or organic acids, enhancing nutrient uptake or protection against plant pathogens. Growth characters, yield, essential oil and its constituents, fixed oil, carbohydrates, soluble sugars and nutrients contents of medicinal and aromatic plants were significantly affected by adding the biological fertilizers compared with recommended chemical fertilizers.

Mini-review: impact and dynamics of surface fouling by solitary and compound ascidians.

Science.gov (United States)

Aldred, Nick; Clare, Anthony S

2014-01-01

Globally, ascidians are a significant contributor to benthic marine fouling communities, but have remained poorly studied in this context. In some cases, such as in shellfish and finfish aquaculture, ascidians are the most problematic of all fouling organisms. The disproportionate impact of ascidian fouling in some specific geographic locations has been related directly to anthropogenic translocation of these organisms around the globe. In the case of ascidians, therefore, the economic issue of biofouling and the ecological ramifications of invasion are inextricably linked. This mini-review briefly discusses the introduction of non-native ascidians to areas where they have subsequently proven to be a significant fouling pest. The elements of ascidian reproductive ecology that support their aggressive fouling character are discussed and the scant information pertaining to their adhesion and adhesives is presented. Finally, strategies for mitigating ascidian fouling are examined. It is suggested that sufficient working knowledge currently exists to support the inclusion of one or more common ascidian species as 'standard' test organisms used for evaluation of novel fouling-resistant surfaces.

Design guidelines for mini-roundabouts

CSIR Research Space (South Africa)

Emslie, I

1997-03-01

Full Text Available Guidelines for Traffic Calming. Concepts and principles relating to the use of mini-roundabouts as a form of intersection control and in the traffic calming context are discussed. Warrants for the implementation of mini-roundabouts and design standards...

MiniBooNE Oscillation Results

International Nuclear Information System (INIS)

Djurcic, Zelimir

2009-01-01

These proceedings summarize the MiniBooNE ν μ → ν e results, describe the first (bar ν) μ → (bar ν) e result, and current analysis effort with the NuMI neutrinos detected in the miniBooNE detector

Polycyclic Aromatic Hydrocarbons

Science.gov (United States)

Salama, Farid

2010-01-01

Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

Plasmonic tunnel junctions for single-molecule redox chemistry.

Science.gov (United States)

de Nijs, Bart; Benz, Felix; Barrow, Steven J; Sigle, Daniel O; Chikkaraddy, Rohit; Palma, Aniello; Carnegie, Cloudy; Kamp, Marlous; Sundararaman, Ravishankar; Narang, Prineha; Scherman, Oren A; Baumberg, Jeremy J

2017-10-20

Nanoparticles attached just above a flat metallic surface can trap optical fields in the nanoscale gap. This enables local spectroscopy of a few molecules within each coupled plasmonic hotspot, with near thousand-fold enhancement of the incident fields. As a result of non-radiative relaxation pathways, the plasmons in such sub-nanometre cavities generate hot charge carriers, which can catalyse chemical reactions or induce redox processes in molecules located within the plasmonic hotspots. Here, surface-enhanced Raman spectroscopy allows us to track these hot-electron-induced chemical reduction processes in a series of different aromatic molecules. We demonstrate that by increasing the tunnelling barrier height and the dephasing strength, a transition from coherent to hopping electron transport occurs, enabling observation of redox processes in real time at the single-molecule level.

Photoacoustic spectroscopic studies of polycyclic aromatic hydrocarbons

Science.gov (United States)

Zaidi, Zahid H.; Kumar, Pardeep; Garg, R. K.

1999-02-01

Because of their involvement in environmental pollutants, in carcinogenic activity, plastics, pharmaceuticals, synthesis of some laser dyes and presence in interstellar space etc., Polycyclic aromatic hydrocarbons (PAHs) are important. As their structure and properties can be varied systematically, they form a beautiful class of molecules for experimental and quantum chemical investigations. These molecules are being studied for last several years by using conventional spectroscopy. In recent years, Photoacoustic (PA) spectroscopy has emerged as a new non-destructive technique with unique capability and sensitivity. The PA effect is the process of generation of acoustic waves in a sample resulting from the absorption of photons. This technique not only reveals non- radiative transitions but also provides information about forbidden singlet-triplet transitions which are not observed normally by the conventional spectroscopy. The present paper deals with the spectroscopic studies of some PAH molecules by PA spectroscopy in the region 250 - 400 nm. The CNDO/S-CI method is used to calculate the electronic transitions with the optimized geometries. A good agreement is found between the experimental and calculated results.

TVT-Secur mini-sling for stress urinary incontinence: a review of outcomes at 12 months.

Science.gov (United States)

Walsh, Colin A

2011-09-01

• Synthetic mid-urethral slings (MUSs) are considered the first choice surgical procedure for stress urinary incontinence. Recent publications have raised concerns about the efficacy of third generation single-incision mini-slings. The present paper is a systematic review of studies reporting 12-month outcomes after the TVT-Secur (TVT-S) procedure. • Pubmed/Medline online databases, abstracts from recent International Continence Society and International Urogynecological Association annual scientific meetings and the Clinicaltrials.gov and Controlled-trials.com online trial registries were searched for English-language articles containing the terms 'TVT-Secur', 'TVT Secur' or 'mini-sling'. The primary outcomes were objective and subjective cure rates at 12 months. Secondary outcomes included peri-operative (vaginal perforation, urinary retention, urinary tract infection [UTI]) and postoperative (mesh exposure, de novo overactive bladder (OAB), dyspareunia and return to theatre) complication rates. • Among 1178 women undergoing the TVT-S procedure, from 10 studies, both objective and subjective cure rate at 12 months was 76%, with objective cure significantly higher in women undergoing the 'U-type' approach. Vaginal perforation was a complication in 1.5% of cases, with a 2.4% incidence of mesh exposure in the first year. The incidence of de novo OAB symptoms was 10%. Rates of urinary retention (2.3%), UTI (4.4%), dyspareunia (1%) and return to theatre for complications (0.8%) were low. In the first year after a TVT-S procedure 5% of women required repeat continence surgery. • Longer-term studies and randomized comparisons with more established MUSs are required before TVT-S should be routinely used in the surgical treatment of stress urinary incontinence. © 2011 THE AUTHOR. BJU INTERNATIONAL © 2011 BJU INTERNATIONAL.

Bioremediation mechanisms of combined pollution of PAHs and heavy metals by bacteria and fungi: A mini review.

Science.gov (United States)

Liu, Shao-Heng; Zeng, Guang-Ming; Niu, Qiu-Ya; Liu, Yang; Zhou, Lu; Jiang, Lu-Hua; Tan, Xiao-Fei; Xu, Piao; Zhang, Chen; Cheng, Min

2017-01-01

In recent years, knowledge in regard to bioremediation of combined pollution of polycyclic aromatic hydrocarbons (PAHs) and heavy metals by bacteria and fungi has been widely developed. This paper reviews the species of bacteria and fungi which can tackle with various types of PAHs and heavy metals entering into environment simultaneously or successively. Microbial activity, pollutants bioavailability and environmental factors (e.g. pH, temperature, low molecular weight organic acids and humic acids) can all affect the bioremediation of PAHs and heavy metals. Moreover, this paper summarizes the remediation mechanisms of PAHs and heavy metals by microbes via elucidating the interaction mechanisms of heavy metals with heavy metals, PAHs/PAHs metabolites with PAHs and PAHs with heavy metals. Based on the above reviews, this paper also discusses the potential research needs for this field. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adsorption and Oxidation of Aromatic Amines on Metal(II Hexacyanocobaltate(III Complexes: Implication for Oligomerization of Exotic Aromatic Compounds

Directory of Open Access Journals (Sweden)

Rachana Sharma

2017-03-01

Full Text Available Based on the hypothesis on the presence of double metal cyanides in the primordial oceans, a series of nano-sized metal(II hexacyanocobaltate(III (MHCCo with the general formula: M3[Co(CN6]2•xH2O (where M = Zn, Fe, Ni and Mn has been synthesized. Surface interaction of aromatic amines, namely aniline, 4-chloroaniline, 4-methylaniline and 4-methoxyaniline with MHCCo particles has been carried out at the concentration range of 100–400 μM at pH~7.0. The percentage binding of aromatic amines on MHCCo surface was found to be in the range of 84%–44%. The trend in adsorption was in accordance to the relative basicity of the studied amines. At the experimental pH, amines reacted rapidly with the surface of the iron(II hexacyanocobaltate, producing colored products that were analyzed by Gas Chromatography Mass Spectroscopy (GC-MS. GC-MS analysis of the colored products demonstrated the formation of dimers of the studied aromatic amines. Surface interaction of aromatic amines with MHCCo was studied by Fourier Transform Infrared (FT-IR spectroscopy and Field Emission Scanning Electron Microscopy (FE-SEM. The change in amine characteristic frequencies, as observed by FT-IR, suggests that interaction took place through the NH2 group on amines with metal ions of hexacyanocobaltate complexes. FE-SEM studies revealed the adherence of 4-methoxyaniline on zinc hexacyanocobaltate particles surface. We proposed that MHCCo might have been formed under the conditions on primitive Earth and may be regarded as an important candidate for concentrating organic molecules through the adsorption process.

Evaluation of the Aromaticity of a Non-Planar Carbon Nano-Structure by Nucleus-Independent Chemical Shift Criterion: Aromaticity of the Nitrogen- Doped Corannulene

Directory of Open Access Journals (Sweden)

A. Reisi-Vanani

2014-04-01

Full Text Available Substitution of two or four carbon atoms by nitrogen in the corannulene molecule as a carbon nanostructure was done and the obtained structures were optimized at MP2/6-31G(d level of theory. Calculations of the nucleus-independent chemical shift (NICS were performed to analyze the aromaticity of the corannulene rings and its derivatives upon doping with N at B3LYP/6-31G(d level of theory. Results showed NICS values in six-membered and five-membered rings of two and four N atoms doped corannulene are different and very dependent to number and position of the N atoms. The values of the mean NICS of all N-doped structures are more positive than intact corannulene that show insertion of N atom to the structures causes to decreasing aromaticity of them.

Diagnostic validity Polish language version of the questionnaire MINI-KID (Mini International Neuropsychiatry Interview for Children and Adolescent).

Science.gov (United States)

Adamowska, Sylwia; Sylwia, Adamowska; Adamowski, Tomasz; Tomasz, Adamowski; Frydecka, Dorota; Dorota, Frydecka; Kiejna, Andrzej; Andrzej, Kiejna

2014-10-01

Since over forty years structuralized interviews for clinical and epidemiological research in child and adolescent psychiatry are being developed that should increase validity and reliability of diagnoses according to classification systems (DSM and ICD). The aim of the study is to assess the validity of the Polish version of MINI-KID (Mini International Neuropsychiatric Interview for Children and Adolescents) in comparison to clinical diagnosis made by a specialist in the field of child and adolescent psychiatry. There were 140 patients included in the study (93 boys, 66.4%, mean age 11.8±3.0 and 47 girls 33.5%, mean age 14.0±2.9). All the patients were diagnosed by the specialist in the field of child and adolescent psychiatry according to ICD-10 criteria and by the independent interviewer with the Polish version of MINI-KID (version 2.0, 2001). There was higher agreement between clinical diagnoses and diagnoses based on MINI-KID interview with respect to eating disorders and externalizing disorders (κ 0.43-0.56) and lower in internalizing disorders (κ 0.13-0.45). In the clinical interview, there was smaller number of diagnostic categories (maximum 3 diagnoses per one patient) in comparison to MINI-KID (maximum 10 diagnoses per one patient), and the smaller percentage of patients with one diagnosis (65,7%) in comparison to MINI-KID interview (72%). Our study has shown satisfactory validity parameters of MINI-KID questionnaire, promoting its use for clinical and epidemiological settings. The Mini International Neuropsychiatry Interview for Children and Adolescent (MINI-KID) is the first structuralized diagnostic interview for assessing mental status in children and adolescents, which has been translated into Polish language. Our validation study demonstrated satisfactory psychometric properties of the questionnaire, enabling its use in clinical practice and in research projects. Copyright © 2014 Elsevier Inc. All rights reserved.

Mini-Sniffer on Lakebed

Science.gov (United States)

1974-01-01

The original Mini-Sniffer on Rogers Dry Lake, adjacent to NASA's Flight Research Center, Edwards AFB. This version of the remotely-piloted vehicle had swept-back wings, tip rudders, nose canards, and an air breathing engine. The Mini-Sniffer was a remotely controlled, propeller-driven vehicle developed at the NASA Flight Research Center (which became the Dryden Flight Research Center, Edwards, California, in 1976) as a potential platform to sample the upper atmosphere for pollution. The vehicle, flown from 1975 to 1977, was one of the earliest attempts by NASA to develop an aircraft that could sense turbulence and measure natural and human-produced atmospheric pollutants at altitudes above 80,000 feet with a variable-load propeller that was never flight-tested. Three Mini-Sniffer vehicles were built. The number 1 Mini-Sniffer vehicle had swept wings with a span of 18 feet and canards on the nose. It flew 12 flights with the gas-powered engine at low altitudes of around 2,500 feet. The number 1 vehicle was then modified into version number 2 by removing the canards and wing rudders and adding wing tips and tail booms. Twenty flights were made with this version, up to altitudes of 20,000 feet. The number 3 vehicle had a longer fuselage, was lighter in weight, and was powered by the non-air-breathing hydrazine engine designed by NASA's Johnson Space Center in Houston, Texas. This version was designed to fly a 25-pound payload to an altitude of 70,000 feet for one hour or to climb to 90,000 feet and glide back. The number 3 Mini-Sniffer made one flight to 20,000 feet and was not flown again because of a hydrazine leak problem. All three versions used a pusher propeller to free the nose area for an atmospheric-sampling payload. At various times the Mini-Sniffer has been considered for exploration in the carbon dioxide atmosphere of the planet Mars, where the gravity (38 percent of that on Earth) would reduce the horsepower needed for flight.

Mini-implant-supported Molar Distalization

Directory of Open Access Journals (Sweden)

Amit Goyal

2012-01-01

Full Text Available Temporary anchorage devices popularly called mini-implants or miniscrews are the latest addition to an orthodontist′s armamentarium. The following case report describes the treatment of a 16-year-old girl with a pleasant profile, moderate crowding and Angle′s Class II molar relationship. Maxillary molar distalization was planned and mini-implants were used to preserve the anterior anchorage. After 13 months of treatment, Class I molar and canine relation was achieved bilaterally and there was no anterior proclination. Thus, mini-implants provide a viable option to the clinician to carry out difficult tooth movements without any side effects.

Mini and Micro Propulsion for Medical Swimmers

Directory of Open Access Journals (Sweden)

JianFeng

2014-02-01

Full Text Available Mini and micro robots, which can swim in an underwater environment, have drawn widespread research interests because of their potential applicability to the medical or biological fields, including delivery and transportation of bio-materials and drugs, bio-sensing, and bio-surgery. This paper reviews the recent ideas and developments of these types of self-propelling devices, ranging from the millimeter scale down to the micro and even the nano scale. Specifically, this review article makes an emphasis on various propulsion principles, including methods of utilizing smart actuators, external magnetic/electric/acoustic fields, bacteria, chemical reactions, etc. In addition, we compare the propelling speed range, directional control schemes, and advantages of the above principles.

Fundamental study of ionization and dissociation processes caused by electron impact in aromatic molecules; application of the quasi-equilibrium theory to phenanthrene and to methylphenanthrenes; Etudes fondamentales des processus d'ionisation et de dissociation des molecules aromatiques par impact electronique et application de la theorie du quasi-equilibre au phenanthrene et aux methyl-phenanthrenes

Energy Technology Data Exchange (ETDEWEB)

Nounou, P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

The quasi-equilibrium theory has been applied only to the family of long chain aliphatic hydrocarbons. We have tried to extend it to phenanthrene and methyl-phenanthrenes molecules, i.e. to aromatic molecules possessing a great number of degrees of freedom. In a first part, we have attempted to give a method of interpretation of the ionization and dissociation processes of the phenanthrenic molecules. These preliminary experimental studies of the behaviour under electron impact of the compounds provide us a great wealth of information about important structural transformations of the molecular and fragment ions, and also about auto-ionization and excitation processes of the studied molecules. The experimental study of the metastable peaks has then confirmed the validity of the preceding dissociation processes, while it gave with more accuracy some thermodynamical values in connection with decomposition reactions. The three studies of the ionization, then dissociation processes and of the metastable peaks, represent the three phases of a general method of interpretation of the fragmentation in mass spectrometry. In order to give this method a theoretical basis, we have carried out the molecular diagrams of each of the studied, compounds, showing by this way the aid of Quantum Mechanics to the study of excited and ionic states. In a second part, we have carried out the mass spectra of the phenanthrene and methyl-phenanthrenes molecules by means of the rate constants expression given by ROSENSTOCK. We have proposed new methods of calculation of the frequency factors, for the aliphatic molecules as well as the aromatic ones. If the rather good agreement observed between the experimental and calculated results cannot be surely attributed to the validity of the theory, however it out-lines the interest presented by the application of this theory to large aromatic molecules. Furthermore, the results at which we arrived provide us with interesting information about the

Effect of binding group on hybridization across the silicon/aromatic-monolayer interface

Energy Technology Data Exchange (ETDEWEB)

Toledano, Tal; Garrick, Rachel; Sinai, Ofer [Department of Materials and Interfaces, Weizmann Institute of Science, Rehovoth 76100 (Israel); Bendikov, Tatyana [Chemical Research Support, Weizmann Institute of Science, Rehovoth 76100 (Israel); Haj-Yahia, Abd-Elrazek [Department of Materials and Interfaces, Weizmann Institute of Science, Rehovoth 76100 (Israel); Lerman, Keti; Alon, Hadas; Sukenik, Chaim N. [Chemistry Department, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900 (Israel); Vilan, Ayelet, E-mail: ayelet.vilan@weizmann.ac.il [Department of Materials and Interfaces, Weizmann Institute of Science, Rehovoth 76100 (Israel); Kronik, Leeor, E-mail: leeor.kronik@weizmann.ac.il [Department of Materials and Interfaces, Weizmann Institute of Science, Rehovoth 76100 (Israel); Cahen, David [Department of Materials and Interfaces, Weizmann Institute of Science, Rehovoth 76100 (Israel)

2015-10-01

We report a combined ultraviolet photoelectron spectroscopy (UPS) and density functional theory (DFT) study of the electronic structure of aromatic self-assembled monolayers covalently bound to Si, using several different aromatic groups (phenyl, biphenyl, and fluorene) and binding groups (O, NH, and CH{sub 2}). We obtain excellent agreement between theory and experiment, which allows for a detailed interpretation of the experimental results. Our analysis reveals a significant effect of the binding group on state hybridization at the organic/inorganic interface. Specifically, it highlights that lone-pair electrons in the binding atom facilitate hybridization between the aromatic system and the Si substrate, resulting in a significant induced density of interface states (IDIS). These interface states are manifested as a broadened HOMO peak in the experimental UPS data and are clearly observed in a theoretical spatially-resolved density of states map. This provides means to control the degree of coupling between substrate and molecule, which may prove useful in the design of transport across organic/inorganic interfaces.

The Individual Features Of Indonesian-Chinese Mini-Novels

Directory of Open Access Journals (Sweden)

Ma Feng

2011-11-01

Full Text Available This article talks about mini-novels in the new period of Indonesian Chinese Literature. Through the overall developing trend of mini-novels’ corpuses, analyzes the individual creative features: firstly, the humor of Mo Mingmiao’s Mini-novels; secondly, the compassion of Xiao Xing’s Mini-novels; thirdly, Yuan Ni’s emotional sonata of The Lost Key-ring. By combination of themes and techniques of the three mini-novels corpuses, the article focuses on the analysis of three writers’ distinctive writing style.

Mini-Sniffer II in Flight

Science.gov (United States)

1976-01-01

This photograph shows the second Mini-Sniffer undergoing flight testing over Rogers Dry Lake in Edwards, California. This version of the Mini-Sniffer lacked the canard of the original version and had wing tips and tail booms added. The Mini-Sniffer was a remotely controlled, propeller-driven vehicle developed at the NASA Flight Research Center (which became the Dryden Flight Research Center, Edwards, California, in 1976) as a potential platform to sample the upper atmosphere for pollution. The vehicle, flown from 1975 to 1977, was one of the earliest attempts by NASA to develop an aircraft that could sense turbulence and measure natural and human-produced atmospheric pollutants at altitudes above 80,000 feet with a variable-load propeller that was never flight-tested. Three Mini-Sniffer vehicles were built. The number 1 Mini-Sniffer vehicle had swept wings with a span of 18 feet and canards on the nose. It flew 12 flights with the gas-powered engine at low altitudes of around 2,500 feet. The number 1 vehicle was then modified into version number 2 by removing the canards and wing rudders and adding wing tips and tail booms. Twenty flights were made with this version, up to altitudes of 20,000 feet. The number 3 vehicle had a longer fuselage, was lighter in weight, and was powered by the non-air-breathing hydrazine engine designed by NASA's Johnson Space Center in Houston, Texas. This version was designed to fly a 25-pound payload to an altitude of 70,000 feet for one hour or to climb to 90,000 feet and glide back. The number 3 Mini-Sniffer made one flight to 20,000 feet and was not flown again because of a hydrazine leak problem. All three versions used a pusher propeller to free the nose area for an atmospheric-sampling payload. At various times the Mini-Sniffer has been considered for exploration in the carbon dioxide atmosphere of the planet Mars, where the gravity (38 percent of that on Earth) would reduce the horsepower needed for flight.

Current Status of the MiniBooNE Experiment

OpenAIRE

Ray, H.; collaboration, for the MiniBooNE

2004-01-01

MiniBooNE is an experiment designed to refute or confirm the LSND anti-nu_mu -> anti-nu_e oscillation result. MiniBooNE will look for oscillations of nu_mu -> nu_e in a closed-box appearance analysis. MiniBooNE began collecting data in 2002, and is expected to continue data taking through 2005. Current MiniBooNE results are presented.

Orthogonal 4,10 and 6,12 substitution of dibenzo[def,mno]chrysene polycyclic aromatic small molecules

KAUST Repository

Koldemir, Unsal; Tinkham, Jonathan S.; Johnson, Robert; Lim, Bogyu; Yemam, Henok A.; Gagnon, Kevin J.; Parkin, Sean; Sellinger, Alan

2017-01-01

A series of new polycyclic aromatic hydrocarbon compounds based on (4,10-disubstituted-dibenzo[def,mno]chrysene-6,12-dione) and 4,10 di-substituted 6,12-bis(triisopropylsilylethynyl)dibenzo[def,mno]chrysene are reported with tunable electronic properties through varied molecular architecture. Starting with an inexpensive commercially available textile dye known as Vat Orange #3, (4,10-dibromo-dibenzo[def,mno] chrysene-6,12-dione) we extended the conjugation at the 4- and 10-positions by the attachment of both electron rich and deficient hexylvinylphthalimide, thiophene, hexylthiophene, triphenylamine, and hexylbithiophene aromatic groups, and studied the resultant optoelectronic properties. By applying various synthetic metal-catalyzed reactions, soluble dibenzo[def,mno]chrysene and dibenzo[def,mno]chrysene-6,12-dione derivatives were achieved with optical edge band gaps between 2.30 eV and 1.65 eV.

Orthogonal 4,10 and 6,12 substitution of dibenzo[def,mno]chrysene polycyclic aromatic small molecules

KAUST Repository

Koldemir, Unsal

2017-07-14

A series of new polycyclic aromatic hydrocarbon compounds based on (4,10-disubstituted-dibenzo[def,mno]chrysene-6,12-dione) and 4,10 di-substituted 6,12-bis(triisopropylsilylethynyl)dibenzo[def,mno]chrysene are reported with tunable electronic properties through varied molecular architecture. Starting with an inexpensive commercially available textile dye known as Vat Orange #3, (4,10-dibromo-dibenzo[def,mno] chrysene-6,12-dione) we extended the conjugation at the 4- and 10-positions by the attachment of both electron rich and deficient hexylvinylphthalimide, thiophene, hexylthiophene, triphenylamine, and hexylbithiophene aromatic groups, and studied the resultant optoelectronic properties. By applying various synthetic metal-catalyzed reactions, soluble dibenzo[def,mno]chrysene and dibenzo[def,mno]chrysene-6,12-dione derivatives were achieved with optical edge band gaps between 2.30 eV and 1.65 eV.

Nano-Sized Cyclodextrin-Based Molecularly Imprinted Polymer Adsorbents for Perfluorinated Compounds—A Mini-Review

Directory of Open Access Journals (Sweden)

Abdalla H. Karoyo

2015-06-01

Full Text Available Recent efforts have been directed towards the design of efficient and contaminant selective remediation technology for the removal of perfluorinated compounds (PFCs from soils, sediments, and aquatic environments. While there is a general consensus on adsorption-based processes as the most suitable methodology for the removal of PFCs from aquatic environments, challenges exist regarding the optimal materials design of sorbents for selective uptake of PFCs. This article reviews the sorptive uptake of PFCs using cyclodextrin (CD-based polymer adsorbents with nano- to micron-sized structural attributes. The relationship between synthesis of adsorbent materials and their structure relate to the overall sorption properties. Hence, the adsorptive uptake properties of CD-based molecularly imprinted polymers (CD-MIPs are reviewed and compared with conventional MIPs. Further comparison is made with non-imprinted polymers (NIPs that are based on cross-linking of pre-polymer units such as chitosan with epichlorohydrin in the absence of a molecular template. In general, MIPs offer the advantage of selectivity, chemical tunability, high stability and mechanical strength, ease of regeneration, and overall lower cost compared to NIPs. In particular, CD-MIPs offer the added advantage of possessing multiple binding sites with unique physicochemical properties such as tunable surface properties and morphology that may vary considerably. This mini-review provides a rationale for the design of unique polymer adsorbent materials that employ an intrinsic porogen via incorporation of a macrocyclic compound in the polymer framework to afford adsorbent materials with tunable physicochemical properties and unique nanostructure properties.

Nano-Sized Cyclodextrin-Based Molecularly Imprinted Polymer Adsorbents for Perfluorinated Compounds—A Mini-Review

Science.gov (United States)

Karoyo, Abdalla H.; Wilson, Lee D.

2015-01-01

Recent efforts have been directed towards the design of efficient and contaminant selective remediation technology for the removal of perfluorinated compounds (PFCs) from soils, sediments, and aquatic environments. While there is a general consensus on adsorption-based processes as the most suitable methodology for the removal of PFCs from aquatic environments, challenges exist regarding the optimal materials design of sorbents for selective uptake of PFCs. This article reviews the sorptive uptake of PFCs using cyclodextrin (CD)-based polymer adsorbents with nano- to micron-sized structural attributes. The relationship between synthesis of adsorbent materials and their structure relate to the overall sorption properties. Hence, the adsorptive uptake properties of CD-based molecularly imprinted polymers (CD-MIPs) are reviewed and compared with conventional MIPs. Further comparison is made with non-imprinted polymers (NIPs) that are based on cross-linking of pre-polymer units such as chitosan with epichlorohydrin in the absence of a molecular template. In general, MIPs offer the advantage of selectivity, chemical tunability, high stability and mechanical strength, ease of regeneration, and overall lower cost compared to NIPs. In particular, CD-MIPs offer the added advantage of possessing multiple binding sites with unique physicochemical properties such as tunable surface properties and morphology that may vary considerably. This mini-review provides a rationale for the design of unique polymer adsorbent materials that employ an intrinsic porogen via incorporation of a macrocyclic compound in the polymer framework to afford adsorbent materials with tunable physicochemical properties and unique nanostructure properties. PMID:28347047

Quality Assurance Framework for Mini-Grids

Energy Technology Data Exchange (ETDEWEB)

Baring-Gould, Ian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burman, Kari [National Renewable Energy Lab. (NREL), Golden, CO (United States); Singh, Mohit [National Renewable Energy Lab. (NREL), Golden, CO (United States); Esterly, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mutiso, Rose [US Department of Energy, Washington, DC (United States); McGregor, Caroline [US Department of Energy, Washington, DC (United States)

2016-11-01

Providing clean and affordable energy services to the more than 1 billion people globally who lack access to electricity is a critical driver for poverty reduction, economic development, improved health, and social outcomes. More than 84% of populations without electricity are located in rural areas where traditional grid extension may not be cost-effective; therefore, distributed energy solutions such as mini-grids are critical. To address some of the root challenges of providing safe, quality, and financially viable mini-grid power systems to remote customers, the U.S. Department of Energy (DOE) teamed with the National Renewable Energy Laboratory (NREL) to develop a Quality Assurance Framework (QAF) for isolated mini-grids. The QAF for mini-grids aims to address some root challenges of providing safe, quality, and affordable power to remote customers via financially viable mini-grids through two key components: (1) Levels of service: Defines a standard set of tiers of end-user service and links them to technical parameters of power quality, power availability, and power reliability. These levels of service span the entire energy ladder, from basic energy service to high-quality, high-reliability, and high-availability service (often considered 'grid parity'); (2) Accountability and performance reporting framework: Provides a clear process of validating power delivery by providing trusted information to customers, funders, and/or regulators. The performance reporting protocol can also serve as a robust monitoring and evaluation tool for mini-grid operators and funding organizations. The QAF will provide a flexible alternative to rigid top-down standards for mini-grids in energy access contexts, outlining tiers of end-user service and linking them to relevant technical parameters. In addition, data generated through implementation of the QAF will provide the foundation for comparisons across projects, assessment of impacts, and greater confidence that

Model Documentation for the MiniCAM

Energy Technology Data Exchange (ETDEWEB)

Brenkert, Antoinette L.; Smith, Steven J.; Kim, Son H.; Pitcher, Hugh M.

2003-07-17

The MiniCAM, short for the Mini-Climate Assessment Model, is an integrated assessment model of moderate complexity focused on energy and agriculture sectors. The model produces emissions of greenhouse gases (carbon dioxide, methane and nitrous oxide) and other radiatively important substances such as sulfur dioxide. Through incorporation of the simple climate model MAGICC, the consequences of these emissions for climate change and sea-level rise can be examined. The MiniCAM is designed to be fast and flexible.

Design of the MiniSLAR system for Bruce A

International Nuclear Information System (INIS)

Gray, M.G.

1995-01-01

Cancellation of Bruce A Retube created the need to perform SLAR on Unit 1. The existing SLAR system cannot reach Unit 1 and alternative systems had limitations. The concept and design of MiniSLAR were driven by the availability of existing components made for Retube. The MiniSLAR concept was developed by a team with members representing operators, technicians, and designers from various departments within Ontario Hydro and GE Canada. Overall project leadership was provided by Bruce A Projects and Modifications Department with assistance from Ontario Hydro Nuclear Technology Services. The responsibility for detailed design was assigned by Ontario Hydro to GE Canada. The detailed design proceeded with continual input and review by the team. The MiniSLAR delivery machine consists of a closure removal ram, a shield plug removal ram and a SLAR tool delivery ram attached to the sliding plate of a horizontal indexing mechanism. The moving plate is constrained by guide rails to a fixed plate and seals against it with o-rings. A snout and clamping mechanism mounts on the front of the fixed plate. The machine mounts atop a work table which provides the various motions required for endfitting engagement. Some operations are performed manually while others are remote and automatic. (author)

Microbial degradation of aliphatic and aliphatic-aromatic co-polyesters.

Science.gov (United States)

Shah, Aamer Ali; Kato, Satoshi; Shintani, Noboru; Kamini, Numbi Ramudu; Nakajima-Kambe, Toshiaki

2014-04-01

Biodegradable plastics (BPs) have attracted much attention since more than a decade because they can easily be degraded by microorganisms in the environment. The development of aliphatic-aromatic co-polyesters has combined excellent mechanical properties with biodegradability and an ideal replacement for the conventional nondegradable thermoplastics. The microorganisms degrading these polyesters are widely distributed in various environments. Although various aliphatic, aromatic, and aliphatic-aromatic co-polyester-degrading microorganisms and their enzymes have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. In this review, we have reported some new microorganisms and their enzymes which could degrade various aliphatic, aromatic, as well as aliphatic-aromatic co-polyesters like poly(butylene succinate) (PBS), poly(butylene succinate)-co-(butylene adipate) (PBSA), poly(ε-caprolactone) (PCL), poly(ethylene succinate) (PES), poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate) and poly(3-hydoxybutyrate-co-3-hydroxyvalterate) (PHB/PHBV), poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(butylene adipate-co-terephthalate (PBAT), poly(butylene succinate-co-terephthalate) (PBST), and poly(butylene succinate/terephthalate/isophthalate)-co-(lactate) (PBSTIL). The mechanism of degradation of aliphatic as well as aliphatic-aromatic co-polyesters has also been discussed. The degradation ability of microorganisms against various polyesters might be useful for the treatment and recycling of biodegradable wastes or bioremediation of the polyester-contaminated environments.

The interstellar carbonaceous aromatic matter as a trap for molecular hydrogen

Science.gov (United States)

Pauzat, F.; Lattelais, M.; Ellinger, Y.; Minot, C.

2011-04-01

We report a theoretical study of the physisorption of molecular hydrogen, H2, on a major component of the interstellar dust, namely, the polyaromatic carbonaceous grains. Going beyond the model of the polycyclic aromatic hydrocarbon freeflyers and its theoretical treatment within the super molecule approach, we consider the graphene surface in a Density Functional Theory periodic approach using plane-wave expansions. The physisorption energy of isolated H2 on that flat and rigid support is determined to be attractive by ˜0.75 kcal mol-1 and practically independent of the orientation with respect to the infinite surface. Since this energy is also not affected by the position (over a ring centre, a carbon atom or the middle of a carbon-carbon bond), we can conclude that H2 is able to move freely like a ball rolling on the graphene support. We also investigate the conditions for multiple physisorption. It leads to a monolayer of H2 molecules where the corresponding interaction energy per H2 amounts to a potential depth of ˜1 kcal mol-1, close to the available experimental estimates ranging from 1.1 to 1.2 kcal mol-1. We show that the most energetically favourable coverage, which corresponds to an arrangement of the H2 molecules, the closest possible to the dimer configuration, leads to a surface density of ˜0.8 × 1015 molecule cm-2. Finally, assuming that 15-20 per cent of the interstellar carbon is locked in aromatic systems, one obtains ˜10-5 of the interstellar hydrogen trapped as H2 on such types of surfaces.

Movimentação de molares inferiores ancorados em mini-parafusos Mandibular molar uprighting, using mini-screw as anchorage

Directory of Open Access Journals (Sweden)

Rosana Canteras Di Matteo

2005-08-01

Full Text Available Freqüentemente a movimentação ortodôntica exige recursos adicionais de ancoragem. Os mini-parafusos têm-se apresentado como uma possível solução. O propósito deste trabalho foi estabelecer um método para a verticalização de molares inferiores inclinados para mesial, utilizando ancoragem em mini-parafusos colocados na região de linha oblíqüa externa da mandíbula. Foram selecionados três pacientes entre 40 a 48 anos (dois do gênero feminino, um do gênero masculino, com molares inferiores inclinados para mesial e distalmente posicionados às áreas edêntulas. Os pacientes foram tratados ortodonticamente durante um período de 6 a 12 meses, com técnica ortodôntica MD3. Mini-parafusos de titânio foram colocados bilateralmente com anestesia local. Uma incisão sobre a linha oblíqüa externa da mandíbula, medindo aproximadamente 1 cm foi realizada em cada lado, distalmente aos molares inclinados. Após descolamento muco-periosteal, mini-parafusos foram implantados e foram realizadas suturas deixando suas cabeças exteriorizadas. Uma semana após a remoção das suturas, cargas ortodônticas (entre 150 a 200 gramas/força foram aplicadas através de forças elásticas. Verificamos que alguma inflamação foi observada ao redor dos mini-parafusos, mas foi controlada com procedimentos de higienização. O procedimento cirúrgico é simples, podendo ser realizado pelo ortodontista; as formas dimensionais dos mini-parafusos são adequadas e estes são de fácil remoção após uso. Concluímos que o uso de mini-parafusos representa uma alternativa efetiva de ancoragem ortodôntica na verticalização de molares inferiores.Tooth movement frequently requires additional anchorage resources. Mini-screws have been used as a possible solution to this matter. The purpose of this study was to establish a method of mandibular molar uprighting, using mini-screw as anchorage, positioned on the mandibular external oblique line, behind and

Standardization of the Korean version of Mini-Mental Adjustment to Cancer (K-Mini-MAC) scale: factor structure, reliability and validity.

Science.gov (United States)

Kang, Jee In; Chung, Hyun Cheol; Kim, Se Joo; Choi, Hye Jin; Ahn, Joong Bae; Jeung, Hei-Cheul; Namkoong, Kee

2008-06-01

Mental adjustment and coping affect the physical outcome and survival as well as quality of life in cancer patients. The Mini-Mental Adjustment to Cancer (Mini-MAC) scale is a new refined, economical and reliable self-rating instrument measuring cognitive and behavioral responses to cancer. The aim of this study was to evaluate the psychometric properties of the Mini-MAC in Korean cancer patients. A total of 208 cancer patients recruited from the Yonsei Cancer Center were assessed with the Mini-MAC and the Hospital Anxiety and Depression Scale (HADS). Principal component analysis with varimax rotation for the Korean version of Mini-MAC (K-Mini-MAC) confirmed four factors. Three had psychometric properties similar to Helpless-Hopeless (HH), Anxious Preoccupation (AP) and Cognitive Avoidance (CA) of the original Mini-MAC. A novel factor, named Positive Attitude, included items of both Fatalism (FA) and Fighting Spirit (FS) from the original version. The five subscales from the original version (AP, HH, FS, FA and CA) and Positive Attitude had acceptable internal reliabilities in our sample (Cronbach's alpha coefficient 0.50-0.86; correlation coefficient of test-retest 0.68-0.88). For the validity, significant interscale correlation was observed in the original five subscales and Positive Attitude. Each subscale including Positive Attitude was also significantly related to Depression and Anxiety of HADS. As a whole, the K-Mini-MAC was a reliable, valid and acceptable tool for Korean cancer patients. These findings can provide information about the cross-cultural validity of Mini-MAC scale's factor structure. Cultural differences were also discussed.

A systematic review on aromatic L-amino acid decarboxylase (5-hydroxytryptophan decarboxylase)

International Nuclear Information System (INIS)

Rahman, M.K.; Nagatsu, T.

1988-11-01

Aromatic L-amino acid decarboxylase (AADC, EC. 4.1.1.28) with L-5-hydroxytryptophan as a substrate (also called L-5-hydroxytryptophan decarboxylase, 5-HTPDC) decarboxylates L-5-hydroxytryptophan to serotonin (5-HT), an important neurotransmitter that involved in the regulation of neuronal functions, behaviour and emotion of higher animals. As it is an important enzyme, many researchers are now working on its physiological functions and properties and also on its isolation, purification and characterization from mammalian tissues. But up to now no systematic review studies have been done on this enzyme. We made systematic studies on this enzyme in tissues and brains of rats, and human subjects. We also developed highly sensitive assay methods of the enzyme. This new method led us to discover the enzyme in the sera of various animals. We examined the developmental changes of 5-HTPDC in the sera of animals. We discovered an endogenous inhibitor of the enzyme in the monkey blood. The purification of the enzyme were performed by us and other researches from the sera, brains, adrenals, liver and kidneys of mammals. These and other results of up to date research papers on 5-HTPDC have been reviewed in this paper. (author). 71 refs, 10 figs, 14 tabs

A review of the immune molecules in the sea cucumber.

Science.gov (United States)

Xue, Zhuang; Li, Hui; Wang, Xiuli; Li, Xia; Liu, Yang; Sun, Jing; Liu, Cenjie

2015-05-01

It is very important to identify and characterize the immune-related genes that respond to pathogens. Until recently, only some of the immune-related genes in sea cucumbers had been characterized. Their expression patterns after pathogen challenges have been analyzed via expressed sequence tag libraries, microarray studies and proteomic approaches. These genes include lectins, antimicrobial peptides, lysozyme, enzymes, clotting protein, pattern recognition proteins, Toll receptors, complement C3 and other humoral factors that might participate in the innate immune system of sea cucumbers. Although the participation of some of these immune molecules in the sea cucumber's innate immune defense against invading pathogens has been demonstrated, the functions of many of the molecules remain unclear. This review focuses on the discovery and functional characterization of the immune-related molecules from the sea cucumber for the first time and provides new insights into the immune mechanisms of the sea cucumber, which opens new possibilities for developing drugs for novel anti-bacterial and antiviral applications in fisheries. Copyright © 2015 Elsevier Ltd. All rights reserved.

Single-molecule fluorescence microscopy review: shedding new light on old problems.

Science.gov (United States)

Shashkova, Sviatlana; Leake, Mark C

2017-08-31

Fluorescence microscopy is an invaluable tool in the biosciences, a genuine workhorse technique offering exceptional contrast in conjunction with high specificity of labelling with relatively minimal perturbation to biological samples compared with many competing biophysical techniques. Improvements in detector and dye technologies coupled to advances in image analysis methods have fuelled recent development towards single-molecule fluorescence microscopy, which can utilize light microscopy tools to enable the faithful detection and analysis of single fluorescent molecules used as reporter tags in biological samples. For example, the discovery of GFP, initiating the so-called 'green revolution', has pushed experimental tools in the biosciences to a completely new level of functional imaging of living samples, culminating in single fluorescent protein molecule detection. Today, fluorescence microscopy is an indispensable tool in single-molecule investigations, providing a high signal-to-noise ratio for visualization while still retaining the key features in the physiological context of native biological systems. In this review, we discuss some of the recent discoveries in the life sciences which have been enabled using single-molecule fluorescence microscopy, paying particular attention to the so-called 'super-resolution' fluorescence microscopy techniques in live cells, which are at the cutting-edge of these methods. In particular, how these tools can reveal new insights into long-standing puzzles in biology: old problems, which have been impossible to tackle using other more traditional tools until the emergence of new single-molecule fluorescence microscopy techniques. © 2017 The Author(s).

Quality Assurance Framework for Mini-Grids

Energy Technology Data Exchange (ETDEWEB)

Esterly, Sean; Baring-Gould, Ian; Booth, Samuel

2017-05-04

To address the root challenges of providing quality power to remote consumers through financially viable mini-grids, the Global Lighting and Energy Access Partnership (Global LEAP) initiative of the Clean Energy Ministerial and the U.S. Department of Energy teamed with the National Renewable Energy Laboratory (NREL) and Power Africa to develop a Quality Assurance Framework (QAF) for isolated mini-grids. The framework addresses both alternating current (AC) and direct current (DC) mini-grids, and is applicable to renewable, fossil-fuel, and hybrid systems.

Conformational switching of ethano-bridged Cu,H2-bis-porphyrin induced by aromatic amines.

Science.gov (United States)

Bettini, Simona; Maglie, Emanuela; Pagano, Rosanna; Borovkov, Victor; Inoue, Yoshihisa; Valli, Ludovico; Giancane, Gabriele

2015-01-01

Cu,H2-bis-porphyrin (Cu,H2-Por2), in which copper porphyrin and free-base porphyrin are linked together by an ethano-bridge, was dissolved in chloroform and spread at the air/liquid subphase interface of a Langmuir trough. The bis-porphyrin derivative, floating film was characterized by reflection spectroscopy and the surface pressure of the floating film was studied as a function of the mean area per molecule. When aromatic amines are dissolved in the subphase, an evident interaction between the bis-porphyrin host and the aromatic amine guest is observed. A clear-cut variation of the profile of surface pressure vs area per molecule curve is observed. Reflection spectroscopy highlights that the aromatic amines dissolved in the subphase are able to induce the syn-to-anti conformational switching in the bis-porphyrin derivative. The Langmuir-Schaefer technique has been used to transfer the floating bis-porphyrin film (when using pure water as a subphase) to a surface plasmon resonance (SPR) substrate and the resulting device was able to detect the presence of aniline at concentrations as low as 1 nM in aqueous solution. The high selectivity of the SPR sensing device has been verified by checking the spectral response of the active layer towards other analytes dissolved in the aqueous solutions.

Conformational switching of ethano-bridged Cu,H2-bis-porphyrin induced by aromatic amines

Directory of Open Access Journals (Sweden)

Simona Bettini

2015-11-01

Full Text Available Cu,H2-bis-porphyrin (Cu,H2-Por2, in which copper porphyrin and free-base porphyrin are linked together by an ethano-bridge, was dissolved in chloroform and spread at the air/liquid subphase interface of a Langmuir trough. The bis-porphyrin derivative, floating film was characterized by reflection spectroscopy and the surface pressure of the floating film was studied as a function of the mean area per molecule. When aromatic amines are dissolved in the subphase, an evident interaction between the bis-porphyrin host and the aromatic amine guest is observed. A clear-cut variation of the profile of surface pressure vs area per molecule curve is observed. Reflection spectroscopy highlights that the aromatic amines dissolved in the subphase are able to induce the syn-to-anti conformational switching in the bis-porphyrin derivative. The Langmuir–Schaefer technique has been used to transfer the floating bis-porphyrin film (when using pure water as a subphase to a surface plasmon resonance (SPR substrate and the resulting device was able to detect the presence of aniline at concentrations as low as 1 nM in aqueous solution. The high selectivity of the SPR sensing device has been verified by checking the spectral response of the active layer towards other analytes dissolved in the aqueous solutions.

Senescence, apoptosis or autophagy? When a damaged cell must decide its path--a mini-review.

Science.gov (United States)

Vicencio, José Miguel; Galluzzi, Lorenzo; Tajeddine, Nicolas; Ortiz, Carla; Criollo, Alfredo; Tasdemir, Ezgi; Morselli, Eugenia; Ben Younes, Amena; Maiuri, Maria Chiara; Lavandero, Sergio; Kroemer, Guido

2008-01-01

Many features of aging result from the incapacity of cells to adapt to stress conditions. When damage accumulates irreversibly, mitotic cells from renewable tissues rely on either of two mechanisms to avoid replication. They can permanently arrest the cell cycle (cellular senescence) or trigger cell death programs. Apoptosis (self-killing) is the best-described form of programmed cell death, but autophagy (self-eating), which is a lysosomal degradation pathway essential for homeostasis, reportedly contributes to cell death as well. Unlike mitotic cells, postmitotic cells like neurons or cardiomyocytes cannot become senescent since they are already terminally differentiated. The fate of these cells entirely depends on their ability to cope with stress. Autophagy then operates as a major homeostatic mechanism to eliminate damaged organelles, long-lived or aberrant proteins and superfluous portions of the cytoplasm. In this mini-review, we briefly summarize the molecular networks that allow damaged cells either to adapt to stress or to engage in programmed-cell-death pathways. (c) 2008 S. Karger AG, Basel.

Design considerations, architecture, and use of the Mini-Sentinel distributed data system.

Science.gov (United States)

Curtis, Lesley H; Weiner, Mark G; Boudreau, Denise M; Cooper, William O; Daniel, Gregory W; Nair, Vinit P; Raebel, Marsha A; Beaulieu, Nicolas U; Rosofsky, Robert; Woodworth, Tiffany S; Brown, Jeffrey S

2012-01-01

We describe the design, implementation, and use of a large, multiorganizational distributed database developed to support the Mini-Sentinel Pilot Program of the US Food and Drug Administration (FDA). As envisioned by the US FDA, this implementation will inform and facilitate the development of an active surveillance system for monitoring the safety of medical products (drugs, biologics, and devices) in the USA. A common data model was designed to address the priorities of the Mini-Sentinel Pilot and to leverage the experience and data of participating organizations and data partners. A review of existing common data models informed the process. Each participating organization designed a process to extract, transform, and load its source data, applying the common data model to create the Mini-Sentinel Distributed Database. Transformed data were characterized and evaluated using a series of programs developed centrally and executed locally by participating organizations. A secure communications portal was designed to facilitate queries of the Mini-Sentinel Distributed Database and transfer of confidential data, analytic tools were developed to facilitate rapid response to common questions, and distributed querying software was implemented to facilitate rapid querying of summary data. As of July 2011, information on 99,260,976 health plan members was included in the Mini-Sentinel Distributed Database. The database includes 316,009,067 person-years of observation time, with members contributing, on average, 27.0 months of observation time. All data partners have successfully executed distributed code and returned findings to the Mini-Sentinel Operations Center. This work demonstrates the feasibility of building a large, multiorganizational distributed data system in which organizations retain possession of their data that are used in an active surveillance system. Copyright © 2012 John Wiley & Sons, Ltd.

Anaerobic catabolism of aromatic compounds: a genetic and genomic view.

Science.gov (United States)

Carmona, Manuel; Zamarro, María Teresa; Blázquez, Blas; Durante-Rodríguez, Gonzalo; Juárez, Javier F; Valderrama, J Andrés; Barragán, María J L; García, José Luis; Díaz, Eduardo

2009-03-01

Aromatic compounds belong to one of the most widely distributed classes of organic compounds in nature, and a significant number of xenobiotics belong to this family of compounds. Since many habitats containing large amounts of aromatic compounds are often anoxic, the anaerobic catabolism of aromatic compounds by microorganisms becomes crucial in biogeochemical cycles and in the sustainable development of the biosphere. The mineralization of aromatic compounds by facultative or obligate anaerobic bacteria can be coupled to anaerobic respiration with a variety of electron acceptors as well as to fermentation and anoxygenic photosynthesis. Since the redox potential of the electron-accepting system dictates the degradative strategy, there is wide biochemical diversity among anaerobic aromatic degraders. However, the genetic determinants of all these processes and the mechanisms involved in their regulation are much less studied. This review focuses on the recent findings that standard molecular biology approaches together with new high-throughput technologies (e.g., genome sequencing, transcriptomics, proteomics, and metagenomics) have provided regarding the genetics, regulation, ecophysiology, and evolution of anaerobic aromatic degradation pathways. These studies revealed that the anaerobic catabolism of aromatic compounds is more diverse and widespread than previously thought, and the complex metabolic and stress programs associated with the use of aromatic compounds under anaerobic conditions are starting to be unraveled. Anaerobic biotransformation processes based on unprecedented enzymes and pathways with novel metabolic capabilities, as well as the design of novel regulatory circuits and catabolic networks of great biotechnological potential in synthetic biology, are now feasible to approach.

Mini-Open Latarjet Procedure for Recurrent Anterior Shoulder Instability

Directory of Open Access Journals (Sweden)

Numa Mercier

2011-01-01

Full Text Available Anterior shoulder instability is a common problem. The Latarjet procedure has been advocated as an option for the treatment of anteroinferior shoulder instability. The purpose of this paper is to explain our surgical procedure titled “Mini-open Latarjet Procedure.” We detailed patient positioning, skin incision, subscapularis approach, and coracoid fixation. Then, we reviewed the literature to evaluate the clinical outcomes of this procedure.

Effect of aromatic compounds on radiation resistance of polymers studied by optical emission

International Nuclear Information System (INIS)

Kawanishi, Shunichi; Hagiwara, Miyuki

1987-10-01

To clarify the effects of condensed bromoacenaphthylene (con-BACN) as a newly developed flame retardant on the radiation resistance of ethylene-propylene-diene-terpolymer (EPDM), optical emission behavior of aromatic compounds, acenaphthylene and acenaphthene as model compound of con-BACN was studied. The energy absorbed in polymer matrix is transferred to the aromatic molecules very fast within 1 ns, and introduces excited states of aromatic compound. The fluorescence from naphthalene units of the additives with peak at 337 and 350 nm (named AT emission band) was observed in EPDM containing acenaphthene or acenaphthylene. When aromatic peroxide was used as a crosslinking agent, another emission band (Xn band) was observed at 400 nm. It was found that these emission bands play a role in trapping sites in which a part of radiation energy release in the form of fluorescence. The energy level of the excited state was correlated to the radiation stability measured with coloration and oxidation reaction of the polymer. Furthermore, acenaphthylene having a reactive vinyl bond forms excimer emission band Ex whose level is lower than those of AT and Xn bands, and therefore, enhances radiation stability of matrix polymer by giving effective routes for energy release. (author)

The Psychometrics of the Mini-K.

Science.gov (United States)

Richardson, George B; Chen, Ching-Chen; Dai, Chia-Liang; Brubaker, Michael D; Nedelec, Joseph L

2017-01-01

Many published studies have employed the Mini-K to measure a single fast-slow life history dimension. However, the internal structure of the Mini-K has not been determined and it is not clear that a single higher order K-factor fits the data. It is also not clear that the Mini-K is measurement invariant across groups such as the sexes. To establish the construct validity of K as well as the broader usefulness of applying life history theory to humans, it is crucial that these psychometric issues are addressed as a part of measure validation efforts. Here we report on three studies that used latent variable modeling and data drawn from two college student samples ( ns = 361 and 300) to elucidate the psychometrics of the Mini-K. We found that (a) the Mini-K had a six dimensional first-order structure, (b) the K-factor provided a parsimonious explanation of the associations among the lower order factors at no significant cost to fit, (c) the Mini-K measured the same K-factor across the sexes, (d) K-factor means did not have the same meaning across the sexes and thus the first-order factors should be used in studies of mean sex differences, and finally, (e) the K-factor was only associated with environment and aspects of mating competition in females. Implications and future directions for life history research are discussed.

Transformation of toxic potential of Jatropha curcas (Ratanjyot into protein source: A mini-review

Directory of Open Access Journals (Sweden)

Amit Shukla

2015-06-01

Full Text Available The production of animal largely depends on supplying of quality feed and proteinaceous supplement to the animals. Jatropha plant can grow in the barren lands, and are used as a source of biodiesel. Besides, the plant may act as a rich proteinaceous source. However, the antinutritional factors present in the seed and seed oil of the plant may hamper the availability and beneficial use of the plant. Curcin and phorbol esters are the major toxic compounds present in the plant; these toxic compounds cause to produce liver and kidney diseases. Detoxification of these toxic compounds by physical and chemical means converting to less toxic seed cake may serve the purpose of using this plant in future as a replacement of costly protein supplement for animals. Therefore, in modern world, it is recommended to utilize the protein source by neutralizing the antinutritional factors. This mini-review describes the updates on how J. curcas can be utilized as a supplementary source of protein for animals by decreasing its toxicity.

Correlation between experimental data of protonation of aromatic compounds at (+) atmospheric pressure photoionization and theoretically calculated enthalpies.

Science.gov (United States)

Ahmed, Arif; Lim, Dongwon; Choi, Cheol Ho; Kim, Sunghwan

2017-06-30

The theoretical enthalpy calculated from the overall protonation reaction (electron transfer plus hydrogen transfer) in positive-mode (+) atmospheric-pressure photoionization (APPI) was compared with experimental results for 49 aromatic compounds. A linear relationship was observed between the calculated ΔH and the relative abundance of the protonated peak. The parameter gives reasonable predictions for all the aromatic hydrocarbon compounds used in this study. A parameter is devised by combining experimental MS data and high-level theoretical calculations. A (+) APPI Q Exactive Orbitrap mass spectrometer was used to obtain MS data for each solution. B3LYP exchange-correlation functions with the standard 6-311+G(df,2p) basis set was used to perform density functional theory (DFT) calculations. All the molecules with ΔH toluene clusters produced protonated ions, regardless of the desolvation temperature. For molecules with ΔH >0, molecular ions were more abundant at typical APPI desolvation temperatures (300°C), while the protonated ions became comparable or dominant at higher temperatures (400°C). The toluene cluster size was an important factor when predicting the ionization behavior of aromatic hydrocarbon ions in (+) APPI. The data used in this study clearly show that the theoretically calculated reaction enthalpy (ΔH) of protonation with toluene dimers can be used to predict the protonation behavior of aromatic compounds. When compounds have a negative ΔH value, the types of ions generated for aromatic compounds could be very well predicted based on the ΔH value. The ΔH can explain overall protonation behavior of compounds with ΔH values >0. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Assessment of atmospheric distribution of polychlorinated biphenyls and polycyclic aromatic hydrocarbons using polyparameter model

Directory of Open Access Journals (Sweden)

Turk-Sekulić Maja M.

2011-01-01

Full Text Available Results of partial or total destruction of industrial plants, military targets, infrastructure, uncontrolled fires and explosions during the conflict period from 1991 to 1999, at the area of Western Balkans, were large amounts of hazardous organic matter that have been generated and emitted in the environment. In order to assess gas/particle partition of seven EPA polychlorinated biphenyls and sixteen EPA polycyclic aromatic hydrocarbons, twenty air samples have been collected at six urban, industrial and highly contaminated localities in Vojvodina. Hi-Vol methodology has been used for collecting ambiental air samples, that simultaneously collects gaseous and particulate phase with polyurethane foam filters (PUF and glass fiber filters (GFF. PUF and GFF filters have been analyzed, and concentration levels of gaseous PCBs and PAHs molecules in gaseous and particulate phase were obtained, converted and expressed through fraction of individual compounds sorbed onto particulate phase of the sample, in total detected quantity. Experimentally gained gas/particle partitioning values of PCBs and PAHs molecules have been compared with PP-LFER model estimated values. Significant deviation has been noticed during comparative analysis of estimated polyparameter model values for complete set of seven PCBs congeners. Much better agreement of experimental and estimated values is for polycyclic aromatic hydrocarbons, especially for molecules with four rings. These results are in a good correlation with literature data where polyparameter model has been used for predicting gas/particle partition of studied group of organic molecules.

Aromatic chemical feedstocks from coal

Energy Technology Data Exchange (ETDEWEB)

Collin, G

1982-06-01

Liquid byproducts of coal carbonization meet some 25% of the world demand for aromatic chemicals, currently at approx. 30 million t/a, in particular 15% of the demand for benzene and over 95% of the demand for condensed aromatics and heteroaromatics. Industrial processing of the aromatic byproducts of coal pressure gasification is carried out to only a minor extent. Other methods that may be employed in future to obtain carbochemical aromatic compounds are solvolysis and supercritical gas extraction, the catalytic liquid-phase hydrogenation and hydropyrolysis of coal, which also permit recovery of benzene and homologues, phenols, and condensed and partially hydrogenated aromatics, and the synthesis of aromatics using methanol as the key compound. As with the present means of obtaining aromatic chemicals from coal, the processes that may in the future be applied on an industrial scale to obtain pure aromatics will only be economically feasible if linked with the manufacture of other mass products and combined with the present production of carbochemical aromatics.

Aromatic raw materials from coal

Energy Technology Data Exchange (ETDEWEB)

Collin, G

1982-06-01

Liquid byproducts of coal carbonization meet some 25% of the world demand for aromatic chemicals, currently at approx. 30 million t/a, in particular 15% of the demand for benzene and over 95% of the demand for condensed aromatics and heteroaromatics. Industrial processing of the aromatic byproducts of coal pressure gasification is carried out to only a minor extent. Other methods that may be employed in future to obtain carbochemical aromatic compounds are solvolysis and supercritical gas extraction, the catalytic liquid-phase hydrogenation and hydropyrolysis of coal, which also permit recovery of benzene and homologues, phenols, and condensed and partially hydrogenated aromatics, and the synthesis of aromatics using methanol as the key compound. As with the present means of obtaining aromatic chemicals from coal, the processes that may in future be applied on an industrial scale to obtain pure aromatics will only be economically feasible if linked with the manufacture of other mass products and combined with the present production of carbochemical aromatics. (In German)

Prenatal exposure to polycyclic aromatic hydrocarbons/aromatics, BDNF and child development

International Nuclear Information System (INIS)

Perera, Frederica; Phillips, David H.; Wang, Ya; Roen, Emily; Herbstman, Julie; Rauh, Virginia; Wang, Shuang; Tang, Deliang

2015-01-01

Objectives: Within a New York City (NYC) birth cohort, we assessed the associations between polycyclic aromatic hydrocarbon (PAH) and other aromatic DNA adducts and brain derived neurotrophic factor (BDNF) concentrations in umbilical cord blood, and neurodevelopment at age 2 years and whether BDNF is a mediator of the associations between PAH/aromatic-DNA adducts and neurodevelopment. Methods: PAH/aromatic-DNA adduct concentrations in cord blood were measured in 505 children born to nonsmoking African-American and Dominican women residing in NYC, and a subset was assessed for neurodevelopment at 2 years using the Bayley Scales of Infant Development Mental Development Index (MDI). A spectrum of PAH/aromatic-DNA adducts was measured using the 32 P-postlabeling assay; DNA adducts formed by benzo[a]pyrene (B[a]P), a representative PAH, were measured by High Performance Liquid Chromatography (HPLC)/fluorescence. BDNF mature protein in cord blood plasma was quantified by an ELISA. Multivariate regression analysis, adjusting for potential confounders, was conducted. Results: PAH/aromatic-DNA adduct concentration measured by postlabeling was inversely associated with BDNF concentration (p=0.02) and with MDI scores at 2 years (p=0.04). BDNF level was positively associated with MDI scores (p=0.003). Restricting to subjects having all three measures (PAH/aromatic-DNA adducts by postlabeling, MDI, and BDNF), results were similar but attenuated (p=0.13, p=0.05, p=0.01, respectively). Associations between B[a]P-DNA adducts and BDNF and B[a]P-DNA adducts and MDI at age 2 years were not significant. At age 3 years, the positive association of BDNF with MDI was not observed. Conclusions: The results at age 2 suggest that prenatal exposure to a spectrum of PAH/aromatic pollutants may adversely affect early neurodevelopment, in part by reducing BDNF levels during the fetal period. However, the same relationship was not seen at age 3. - Highlights: • Cord blood Polycyclic Aromatic

Prenatal exposure to polycyclic aromatic hydrocarbons/aromatics, BDNF and child development

Energy Technology Data Exchange (ETDEWEB)

Perera, Frederica, E-mail: fpp1@columbia.edu [Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); Columbia Center for Children' s Environmental Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); Phillips, David H. [Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King' s College London, Franklin-Wilkins Building, London SE1 9NH (United Kingdom); Wang, Ya [Columbia Center for Children' s Environmental Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); Department of Biostatistics, Mailman School of Public Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); Roen, Emily; Herbstman, Julie [Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); Columbia Center for Children' s Environmental Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); Rauh, Virginia [Columbia Center for Children' s Environmental Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); The Heilbrunn Department of Population and Family Health, Columbia University, 60 Haven Avenue, New York, NY 10032 (United States); Wang, Shuang [Columbia Center for Children' s Environmental Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); Department of Biostatistics, Mailman School of Public Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); Tang, Deliang [Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States); Columbia Center for Children' s Environmental Health, Columbia University, 722 W. 168th St., New York, NY 10032 (United States)

2015-10-15

Objectives: Within a New York City (NYC) birth cohort, we assessed the associations between polycyclic aromatic hydrocarbon (PAH) and other aromatic DNA adducts and brain derived neurotrophic factor (BDNF) concentrations in umbilical cord blood, and neurodevelopment at age 2 years and whether BDNF is a mediator of the associations between PAH/aromatic-DNA adducts and neurodevelopment. Methods: PAH/aromatic-DNA adduct concentrations in cord blood were measured in 505 children born to nonsmoking African-American and Dominican women residing in NYC, and a subset was assessed for neurodevelopment at 2 years using the Bayley Scales of Infant Development Mental Development Index (MDI). A spectrum of PAH/aromatic-DNA adducts was measured using the {sup 32}P-postlabeling assay; DNA adducts formed by benzo[a]pyrene (B[a]P), a representative PAH, were measured by High Performance Liquid Chromatography (HPLC)/fluorescence. BDNF mature protein in cord blood plasma was quantified by an ELISA. Multivariate regression analysis, adjusting for potential confounders, was conducted. Results: PAH/aromatic-DNA adduct concentration measured by postlabeling was inversely associated with BDNF concentration (p=0.02) and with MDI scores at 2 years (p=0.04). BDNF level was positively associated with MDI scores (p=0.003). Restricting to subjects having all three measures (PAH/aromatic-DNA adducts by postlabeling, MDI, and BDNF), results were similar but attenuated (p=0.13, p=0.05, p=0.01, respectively). Associations between B[a]P-DNA adducts and BDNF and B[a]P-DNA adducts and MDI at age 2 years were not significant. At age 3 years, the positive association of BDNF with MDI was not observed. Conclusions: The results at age 2 suggest that prenatal exposure to a spectrum of PAH/aromatic pollutants may adversely affect early neurodevelopment, in part by reducing BDNF levels during the fetal period. However, the same relationship was not seen at age 3. - Highlights: • Cord blood Polycyclic

Mini-Membrane Evaporator for Contingency Spacesuit Cooling

Science.gov (United States)

Makinen, Janice V.; Bue, Grant C.; Campbell, Colin; Petty, Brian; Craft, Jesse; Lynch, William; Wilkes, Robert; Vogel, Matthew

2015-01-01

The next-generation Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is integrating a number of new technologies to improve reliability and functionality. One of these improvements is the development of the Auxiliary Cooling Loop (ACL) for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feedwater assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the full-sized AEMU PLSS cooling device, the Spacesuit Water Membrane Evaporator (SWME), but Mini-ME occupies only approximately 25% of the volume of SWME, thereby providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology, which relies upon a Secondary Oxygen Vessel; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a reduction in SOV size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The first iteration of Mini-ME was developed and tested in-house. Mini-ME is currently packaged in AEMU PLSS 2.0, where it is being tested in environments and situations that are representative of potential future Extravehicular Activities (EVA's). The second iteration of Mini-ME, known as Mini-ME2, is currently being developed to offer more heat rejection capability. The development of this contingency evaporative cooling system will contribute to a more robust and comprehensive AEMU PLSS.

Substrate specific hydrolysis of aromatic and aromatic-aliphatic esters in orchid tissue cultures

Directory of Open Access Journals (Sweden)

Agnieszka Mironowicz

2014-01-01

Full Text Available We found that tissue cultures of higher plants were able, similarly as microorganisms, to transform low-molecular-weight chemical compounds. In tissue cultures of orchids (Cymbidium 'Saint Pierre' and Dendrobium phalaenopsis acetates of phenols and aromatic-aliphatic alcohols were hydrolyzed, whereas methyl esters of aromatic and aromatic-aliphatic acids did not undergo this reaction. Acetates of racemic aromatic-aliphatic alcohols were hydrolyzed with distinct enantiospecificity.

MINI-THESAURUS, Energy Data Base Subject Thesaurus Generator

International Nuclear Information System (INIS)

Paulk, J.W.

2003-01-01

1 - Description of program or function: MINI-THESAURUS allows the user to subset into highly-specialized 'mini-thesauri' the Energy Data Base (EDB) Subject Thesaurus, which contains the standard vocabulary of indexing terms (descriptors) developed and structured by the Office of Scientific and Technical Information (OSTI) for the building and maintenance of the U.S. Department of Energy (DOE) energy information databases. This structured vocabulary reflects the scope of DOE's research, development, and technological programs and encompasses terminology derived not only from the basic sciences but also from the areas of energy, conservation, safety, environmental impact, and regulation. Entire word blocks may be copied from the primary Subject Thesaurus, from another mini-thesaurus, or both, and subsequently modified through the addition of new terms, the deletion of existing terms, and changes to the internal relationships among the word blocks within the mini-thesaurus to create a new, special-purpose thesaurus. MINI-THESAURUS also provides the ability to copy the entire Subject Thesaurus and to treat the copy as a mini-thesaurus, thus allowing one to examine the effects of major changes to the thesaurus structure without having to modify the primary, on-line Thesaurus. The copy operation also optimizes the Subject Thesaurus structure. An interactive user having update privileges for a specific mini-thesaurus and access to the TeX and PostScript proprietary software can produce the mini-thesaurus in printed publication format. Once the mini-thesaurus has been published, periodic supplements may be generated based on date of entry or change maintained by the Thesaurus software. 2 Restrictions on the complexity of the problem: The system enforces the OSTI rules for Thesaurus development

Two-dimensional character of internal rotation of furfural and other five-member heterocyclic aromatic aldehydes

Science.gov (United States)

Bataev, Vadim A.; Pupyshev, Vladimir I.; Godunov, Igor A.

2016-05-01

The features of nuclear motion corresponding to the rotation of the formyl group (CHO) are studied for the molecules of furfural and some other five-member heterocyclic aromatic aldehydes by the use of MP2/6-311G** quantum chemical approximation. It is demonstrated that the traditional one-dimensional models of internal rotation for the molecules studied have only limited applicability. The reason is the strong kinematic interaction of the rotation of the CHO group and out-of-plane CHO deformation that is realized for the molecules under consideration. The computational procedure based on the two-dimensional approximation is considered for low lying vibrational states as more adequate to the problem.

Spurious RF signals emitted by mini-UAVs

Science.gov (United States)

Schleijpen, Ric (H. M. A.); Voogt, Vincent; Zwamborn, Peter; van den Oever, Jaap

2016-10-01

This paper presents experimental work on the detection of spurious RF emissions of mini Unmanned Aerial Vehicles (mini-UAV). Many recent events have shown that mini-UAVs can be considered as a potential threat for civil security. For this reason the detection of mini-UAVs has become of interest to the sensor community. The detection, classification and identification chain can take advantage of different sensor technologies. Apart from the signatures used by radar and electro-optical sensor systems, the UAV also emits RF signals. These RF signatures can be split in intentional signals for communication with the operator and un-intentional RF signals emitted by the UAV. These unintentional or spurious RF emissions are very weak but could be used to discriminate potential UAV detections from false alarms. The goal of this research was to assess the potential of exploiting spurious emissions in the classification and identification chain of mini-UAVs. It was already known that spurious signals are very weak, but the focus was on the question whether the emission pattern could be correlated to the behaviour of the UAV. In this paper experimental examples of spurious RF emission for different types of mini-UAVs and their correlation with the electronic circuits in the UAVs will be shown

LOW TEMPERATURE FORMATION OF NITROGEN-SUBSTITUTED POLYCYCLIC AROMATIC HYDROCARBONS (PANHs)—BARRIERLESS ROUTES TO DIHYDRO(iso)QUINOLINES

Energy Technology Data Exchange (ETDEWEB)

Parker, Dorian S. N.; Yang, Tao; Dangi, Beni B.; Kaiser, Ralf I. [Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Bera, Partha P.; Lee, Timothy J., E-mail: ralfk@hawaii.edu, E-mail: Timothy.J.Lee@nasa.gov [Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, Mountain View, CA 94035 (United States)

2015-12-20

Meteorites contain bio-relevant molecules such as vitamins and nucleobases, which consist of aromatic structures with embedded nitrogen atoms. Questions remain over the chemical mechanisms responsible for the formation of nitrogen-substituted polycyclic aromatic hydrocarbons (PANHs) in extraterrestrial environments. By exploiting single collision conditions, we show that a radical mediated bimolecular collision between pyridyl radicals and 1,3-butadiene in the gas phase forms nitrogen-substituted polycyclic aromatic hydrocarbons (PANHs) 1,4-dihydroquinoline and to a minor amount 1,4-dihydroisoquinoline. The reaction proceeds through the formation of a van der Waals complex, which circumnavigates the entrance barrier implying it can operate at very low kinetic energy and therefore at low temperatures of 10 K as present in cold molecular clouds such as TMC-1. The discovery of facile de facto barrierless exoergic reaction mechanisms leading to PANH formation could play an important role in providing a population of aromatic structures upon which further photo-processing of ice condensates could occur to form nucleobases.

Mini-Sniffer III on Lakebed

Science.gov (United States)

1976-01-01

The third remotely-piloted Mini-Sniffer research vehicle rests on the lakebed adjacent to the Dryden Flight Research Center, Edwards, California. This view shows the wing shape, hydrazine engine, and the tail booms. The Mini-Sniffer was a remotely controlled, propeller-driven vehicle developed at the NASA Flight Research Center (which became the Dryden Flight Research Center, Edwards, California, in 1976) as a potential platform to sample the upper atmosphere for pollution. The vehicle, flown from 1975 to 1977, was one of the earliest attempts by NASA to develop an aircraft that could sense turbulence and measure natural and human-produced atmospheric pollutants at altitudes above 80,000 feet with a variable-load propeller that was never flight-tested. Three Mini-Sniffer vehicles were built. The number 1 Mini-Sniffer vehicle had swept wings with a span of 18 feet and canards on the nose. It flew 12 flights with the gas-powered engine at low altitudes of around 2,500 feet. The number 1 vehicle was then modified into version number 2 by removing the canards and wing rudders and adding wing tips and tail booms. Twenty flights were made with this version, up to altitudes of 20,000 feet. The number 3 vehicle had a longer fuselage, was lighter in weight, and was powered by the non-air-breathing hydrazine engine designed by NASA's Johnson Space Center in Houston, Texas. This version was designed to fly a 25-pound payload to an altitude of 70,000 feet for one hour or to climb to 90,000 feet and glide back. The number 3 Mini-Sniffer made one flight to 20,000 feet and was not flown again because of a hydrazine leak problem. All three versions used a pusher propeller to free the nose area for an atmospheric-sampling payload. At various times the Mini-Sniffer has been considered for exploration in the carbon dioxide atmosphere of the planet Mars, where the gravity (38 percent of that on Earth) would reduce the horsepower needed for flight.

Feasibility of mini-tablets as a flexible drug delivery tool.

Science.gov (United States)

Mitra, Biplob; Chang, Jessica; Wu, Sy-Juen; Wolfe, Chad N; Ternik, Robert L; Gunter, Thomas Z; Victor, Michael C

2017-06-15

Mini-tablets have potential applications as a flexible drug delivery tool in addition to their generally perceived use as multi-particulates. That is, mini-tablets could provide flexibility in dose finding studies and/or allow for combination therapies in the clinic. Moreover, mini-tablets with well controlled quality attributes could be a prudent choice for administering solid dosage forms as a single unit or composite of multiple mini-tablets in patient populations with swallowing difficulties (e.g., pediatric and geriatric populations). This work demonstrated drug substance particle size and concentration ranges that achieve acceptable mini-tablet quality attributes for use as a single or composite dosage unit. Immediate release and orally disintegrating mini-tablet formulations with 30μm to 350μm (particle size d 90 ) acetaminophen and Compap™ L (90% acetaminophen) at concentrations equivalent to 6.7% and 26.7% acetaminophen were evaluated. Mini-tablets achieved acceptable weight variability, tensile strength, friability, and disintegration time at a reasonable solid fraction for each formulation. The content uniformity was acceptable for mini-tablets of 6.7% formulations with ≤170μm drug substance, mini-tablets of all 26.7% formulations, and composite dosage units containing five or more mini-tablets of any formulation. Results supported the manufacturing feasibility of quality mini-tablets, and their applicability as a flexible drug delivery tool. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis of a Fluorescent Acridone Using a Grignard Addition, Oxidation, and Nucleophilic Aromatic Substitution Reaction Sequence

Science.gov (United States)

Goodrich, Samuel; Patel, Miloni; Woydziak, Zachary R.

2015-01-01

A three-pot synthesis oriented for an undergraduate organic chemistry laboratory was developed to construct a fluorescent acridone molecule. This laboratory experiment utilizes Grignard addition to an aldehyde, alcohol oxidation, and iterative nucleophilic aromatic substitution steps to produce the final product. Each of the intermediates and the…

Side Chain Cyclized Aromatic Amino Acids

DEFF Research Database (Denmark)

Van der Poorten, Olivier; Knuhtsen, Astrid; Sejer Pedersen, Daniel

2016-01-01

Constraining the conformation of flexible peptides is a proven strategy to increase potency, selectivity, and metabolic stability. The focus has mostly been on constraining the backbone dihedral angles; however, the correct orientation of the amino acid side chains (χ-space) that constitute...... the peptide pharmacophore is equally important. Control of χ-space utilizes conformationally constrained amino acids that favor, disfavor, or exclude the gauche (-), the gauche (+), or the trans conformation. In this review we focus on cyclic aromatic amino acids in which the side chain is connected...... to the peptide backbone to provide control of χ(1)- and χ(2)-space. The manifold applications for cyclized analogues of the aromatic amino acids Phe, Tyr, Trp, and His within peptide medicinal chemistry are showcased herein with examples of enzyme inhibitors and ligands for G protein-coupled receptors....

Simultaneous atomization and ionization of large organic molecules using femtosecond laser ablation

International Nuclear Information System (INIS)

Kurata-Nishimura, Mizuki; Tokanai, Fuyuki; Matsuo, Yukari; Kobayashi, Tohru; Kawai, Jun; Kumagai, Hiroshi; Midorikawa, Katsumi; Tanihata, Isao; Hayashizaki, Yoshihide

2002-01-01

We have experimentally demonstrated femtosecond laser ablation for simultaneous atomization and ionization (fs-SAI) of organic molecules on solid substrates. We find most of the constituent atoms of organic molecules are atomized and ionized non-resonantly by femtosecond laser ablation. This observation is in contrast with that for the photoionization of cyclic aromatic hydrocarbons by femtosecond laser in the gas phase where little fragmentation has been observed. Crucial contribution of ablation plasma of solid sample to fs-SAI process is suggested. The ratio of natural abundance of stable isotopes contained in sample molecules is well reproduced, which confirms fs-SAI can be applied to the quantitative chemical analysis of isotope-labeled large organic molecules

Engineering Aromatic-Aromatic Interactions To Nucleate Folding in Intrinsically Disordered Regions of Proteins.

Science.gov (United States)

Balakrishnan, Swati; Sarma, Siddhartha P

2017-08-22

Aromatic interactions are an important force in protein folding as they combine the stability of a hydrophobic interaction with the selectivity of a hydrogen bond. Much of our understanding of aromatic interactions comes from "bioinformatics" based analyses of protein structures and from the contribution of these interactions to stabilizing secondary structure motifs in model peptides. In this study, the structural consequences of aromatic interactions on protein folding have been explored in engineered mutants of the molten globule protein apo-cytochrome b 5 . Structural changes from disorder to order due to aromatic interactions in two variants of the protein, viz., WF-cytb5 and FF-cytb5, result in significant long-range secondary and tertiary structure. The results show that 54 and 52% of the residues in WF-cytb5 and FF-cytb5, respectively, occupy ordered regions versus 26% in apo-cytochrome b 5 . The interactions between the aromatic groups are offset-stacked and edge-to-face for the Trp-Phe and Phe-Phe mutants, respectively. Urea denaturation studies indicate that both mutants have a C m higher than that of apo-cytochrome b 5 and are more stable to chaotropic agents than apo-cytochrome b 5 . The introduction of these aromatic residues also results in "trimer" interactions with existing aromatic groups, reaffirming the selectivity of the aromatic interactions. These studies provide insights into the aromatic interactions that drive disorder-to-order transitions in intrinsically disordered regions of proteins and will aid in de novo protein design beyond small peptide scaffolds.

Mini-marathon groups: psychological "first aid" following disasters.

Science.gov (United States)

Terr, L C

1992-01-01

Large group counseling sessions for soldiers following battle have been commonly used since World War II. The author conceptualizes and demonstrates how these mini-marathon sessions can be adapted to support all ages and types of civilians involved in disasters. Mini-marathons take about 3 hours and are divided into three sections: story sharing, symptom sharing, and suggestions for self-help, including sharing tales of heroism and survival. After an initial mini-marathon session, a second session may be held emphasizing creativity. The author also describes how mini-marathons can be adapted for therapists who will lead their own sessions.

The use of mini-samples in palaeomagnetism

Science.gov (United States)

Böhnel, Harald; Michalk, Daniel; Nowaczyk, Norbert; Naranjo, Gildardo Gonzalez

2009-10-01

Rock cores of ~25 mm diameter are widely used in palaeomagnetism. Occasionally smaller diameters have been used as well which represents distinct advantages in terms of throughput, weight of equipment and core collections. How their orientation precision compares to 25 mm cores, however, has not been evaluated in detail before. Here we compare the site mean directions and their statistical parameters for 12 lava flows sampled with 25 mm cores (standard samples, typically 8 cores per site) and with 12 mm drill cores (mini-samples, typically 14 cores per site). The site-mean directions for both sample sizes appear to be indistinguishable in most cases. For the mini-samples, site dispersion parameters k on average are slightly lower than for the standard samples reflecting their larger orienting and measurement errors. Applying the Wilcoxon signed-rank test the probability that k or α95 have the same distribution for both sizes is acceptable only at the 17.4 or 66.3 per cent level, respectively. The larger mini-core numbers per site appears to outweigh the lower k values yielding also slightly smaller confidence limits α95. Further, both k and α95 are less variable for mini-samples than for standard size samples. This is interpreted also to result from the larger number of mini-samples per site, which better averages out the detrimental effect of undetected abnormal remanence directions. Sampling of volcanic rocks with mini-samples therefore does not present a disadvantage in terms of the overall obtainable uncertainty of site mean directions. Apart from this, mini-samples do present clear advantages during the field work, as about twice the number of drill cores can be recovered compared to 25 mm cores, and the sampled rock unit is then more widely covered, which reduces the contribution of natural random errors produced, for example, by fractures, cooling joints, and palaeofield inhomogeneities. Mini-samples may be processed faster in the laboratory, which is of

The Infrared Spectra of Polycyclic Aromatic Hydrocarbons with Excess Peripheral H Atoms (H(sub n)-PAHs) and their Relation to the 3.4 and 6.9 Micrometer PAH Emission Features

Science.gov (United States)

Sandford, Scott A.; Bernstein, Max P.; Materese, Christopher K.

2013-01-01

A population of polycyclic aromatic hydrocarbons (PAHs) and related materials are thought to be responsible for the family of infrared emission features that are seen towards a wide variety of astrophysical environments. A potentially important subclass of these materials are polycyclic aromatic hydrocarbons whose edges contain excess H atoms (H(sub n)-PAHs). While it has been suggested that this type of compound may be present in the interstellar population, it has been difficult to properly assess this possibility because of a lack of suitable infrared laboratory spectra to assist with analysis of the astronomical data. We present the 4000-500 cm(exp -1) (2.5-20 micrometers) infrared spectra of 23 H(sub n)-PAHs and related molecules isolated in argon matrices, under conditions suitable for use in the interpretation of astronomical data. The spectra of molecules with mixed aromatic and aliphatic domains show unique characteristics that distinguish them from their fully aromatic PAH equivalents. We discuss the changes to the spectra of these types of molecules as they transition from fully aromatic to fully aliphatic forms. The implications for the interpretation of astronomical spectra are discussed with specific emphasis on the 3.4 and 6.9 micrometer features. Laboratory data is compared with emission spectra from IRAS 21282+5050, an object with normal PAH emission features, in addition to IRAS 22272+5435 and IRAS 0496+3429, two protoplanetary nebulae with abnormally large 3.4 micrometer features. We show that 'normal' PAH emission objects contain relatively few H(sub n)-PAHs in their emitter populations, but less evolved protoplanetary nebulae may contain significant abundances of these molecules.

HIGH-RESOLUTION IR ABSORPTION SPECTROSCOPY OF POLYCYCLIC AROMATIC HYDROCARBONS: THE REALM OF ANHARMONICITY

Energy Technology Data Exchange (ETDEWEB)

Maltseva, Elena; Buma, Wybren Jan [University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Petrignani, Annemieke; Candian, Alessandra; Mackie, Cameron J.; Tielens, Alexander G. G. M. [Leiden Observatory, Niels Bohrweg 2, 2333 CA Leiden (Netherlands); Huang, Xinchuan; Lee, Timothy J. [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Oomens, Jos, E-mail: w.j.buma@uva.nl, E-mail: petrignani@strw.leidenuniv.nl [Radboud University, Toernooiveld 7, 6525 ED Nijmegen (Netherlands)

2015-11-20

We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3-μm CH stretching region of polycyclic aromatic hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold (∼4 K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computational program SPECTRO, providing anharmonic predictions with a Fermi-resonance treatment that utilizes intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination bands as possible candidates to resolve remaining discrepancies. The anharmonic spectra as calculated with SPECTRO lead to predictions of the main bands that fall within 0.5% of the experimental frequencies. The implications for the aromatic infrared bands, specifically the 3-μm band, are discussed.

High-Resolution IR Absorption Spectroscopy of Polycyclic Aromatic Hydrocarbons: The Realm of Anharmonicity

Science.gov (United States)

Maltseva, Elena; Petrignani, Annemieke; Candian, Alessandra; Mackie, Cameron J.; Huang, Xinchuan; Lee, Timothy J.; Tielens, Alexander G. G. M.; Oomens, Jos; Buma, Wybren Jan

2016-01-01

We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3 micrometers CH stretching region of Polycyclic Aromatic Hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold ((is) approximately 4K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computational program SPECTRO, providing anharmonic predictions enhanced with a Fermi-resonance treatment that utilizes intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination bands as possible candidates to resolve remaining discrepancies. The anharmonic spectra as calculated with SPECTRO lead to predictions of the main modes that fall within 0.5% of the experimental frequencies. The implications for the Aromatic Infrared Bands, specifically the 3-m band are discussed.

Heat transfer and pressure drop characteristics of mini-fin structures

International Nuclear Information System (INIS)

Jiang Peixue; Xu Ruina

2007-01-01

Forced convection heat transfer of air and water in bronze and pure copper mini-fin structures and mini-channel structures was investigated experimentally. The mini-fin dimensions were 0.7 mm x 0.2 mm and 0.8 mm x 0.4 mm. The tests included both staggered diamond-shaped and in-line square mini-fin arrangements. The tests investigated the effects of structures, mini-fin dimensions and arrangement, test section materials, and fluid properties on the convection heat transfer and heat transfer enhancement. For the tested conditions, the convection heat transfer coefficient was increased 9-21 fold for water and 12-38 fold for air in the mini-fin structures compared with an empty plate channel. The friction factor and flow resistance in the mini-channel structures and the in-line square mini-fin arrangement were much less than in the staggered diamond-shaped mini-fin arrangement. For the small channel width, W c = 0.2 mm, the convection heat transfer with the in-line square array structure was more intense than with the staggered diamond-shaped structure, the mini-channel structure or the porous media. For the larger channel width, W c = 0.4 mm, the convection heat transfer in the staggered diamond-shaped array structure was more intense than in the others systems while the in-line square structure had the best overall thermal-hydraulic performance

Electronic structure of BN-aromatics: Choice of reliable computational tools

Science.gov (United States)

Mazière, Audrey; Chrostowska, Anna; Darrigan, Clovis; Dargelos, Alain; Graciaa, Alain; Chermette, Henry

2017-10-01

The importance of having reliable calculation tools to interpret and predict the electronic properties of BN-aromatics is directly linked to the growing interest for these very promising new systems in the field of materials science, biomedical research, or energy sustainability. Ionization energy (IE) is one of the most important parameters to approach the electronic structure of molecules. It can be theoretically estimated, but in order to evaluate their persistence and propose the most reliable tools for the evaluation of different electronic properties of existent or only imagined BN-containing compounds, we took as reference experimental values of ionization energies provided by ultra-violet photoelectron spectroscopy (UV-PES) in gas phase—the only technique giving access to the energy levels of filled molecular orbitals. Thus, a set of 21 aromatic molecules containing B-N bonds and B-N-B patterns has been merged for a comparison between experimental IEs obtained by UV-PES and various theoretical approaches for their estimation. Time-Dependent Density Functional Theory (TD-DFT) methods using B3LYP and long-range corrected CAM-B3LYP functionals are used, combined with the Δ SCF approach, and compared with electron propagator theory such as outer valence Green's function (OVGF, P3) and symmetry adapted cluster-configuration interaction ab initio methods. Direct Kohn-Sham estimation and "corrected" Kohn-Sham estimation are also given. The deviation between experimental and theoretical values is computed for each molecule, and a statistical study is performed over the average and the root mean square for the whole set and sub-sets of molecules. It is shown that (i) Δ SCF+TDDFT(CAM-B3LYP), OVGF, and P3 are the most efficient way for a good agreement with UV-PES values, (ii) a CAM-B3LYP range-separated hybrid functional is significantly better than B3LYP for the purpose, especially for extended conjugated systems, and (iii) the "corrected" Kohn-Sham result is a

STUDY OF FACTORS AFFECTING DEVELOPMENT OF FOOD AROMATIZATION

Directory of Open Access Journals (Sweden)

Н.Ye. Dubova

2017-10-01

Full Text Available The specific understanding of food philosophy according to the facts of development of cooking technologies and growth rate of food range is given. As it has been proven by historical stages of production of flavorings, aroma is one of the important organoleptic ingredients for food developers. A review of food production based on development of nanotechnologies, as well as promising and cautioning publications on nanotechnologies in the food sector is presented. On the basis of the literary analysis, the future impact of nanotechnologies on the evolution of the aromatization process of food products is predicted. It has been determined that the peculiarity of the development mentioned above lies in the use of plant enzymes and / or flavor precursors in the nanoscale range. The example of enzymatic breakdown of polyunsaturated fatty acids of plant cell membranes as one of the ways of creating fresh flavor of many fruits, namely C6-C9 aldehydes and alcohols, is considered. It is noted that green fresh aromatic ingredients are needed to improve the organoleptic profile of foods from heat-treated vegetables, melons and gourds. The following factors affecting the development of food aromatization are defined: the decreased differentiation of principles of healthy nutrition and fast food, repetition of natural processes of aroma formation, application of wild green leafy vegetables, and evolution of medical nutrition. The information on food aromatization by packing with autonomous mixing and their approximate assortment is given. The innovations in food aromatization are aimed at quality nutrition, time saving, recreation and entertainment, meeting specific needs (vegetarian dishes, restrictive diets.

Mini-Split Heat Pumps Multifamily Retrofit Feasibility Study

Energy Technology Data Exchange (ETDEWEB)

Dentz, Jordan [ARIES Collaborative, New York, NY (United States); Podorson, David [ARIES Collaborative, New York, NY (United States); Varshney, Kapil [ARIES Collaborative, New York, NY (United States)

2014-05-01

Mini-split heat pumps can provide space heating and cooling in many climates and are relatively affordable. These and other features make them potentially suitable for retrofitting into multifamily buildings in cold climates to replace electric resistance heating or other outmoded heating systems. This report investigates the suitability of mini-split heat pumps for multifamily retrofits. Various technical and regulatory barriers are discussed and modeling was performed to compare long-term costs of substituting mini-splits for a variety of other heating and cooling options. A number of utility programs have retrofit mini-splits in both single family and multifamily residences. Two such multifamily programs are discussed in detail.

The Relation between Structure and Quantum Interference in Single Molecule Junctions

DEFF Research Database (Denmark)

Markussen, Troels; Stadler, Robert; Thygesen, Kristian Sommer

2010-01-01

Quantum interference (QI) of electron pathways has recently attracted increased interest as an enabling tool for single-molecule electronic devices. Although various molecular systems have been shown to exhibit QI effects and a number of methods have been proposed for its analysis, simple...... guidelines linking the molecular structure to QI effects in the phase-coherent transport regime have until now been lacking. In the present work we demonstrate that QI in aromatic molecules is intimately related to the topology of the molecule’s π system and establish a simple graphical scheme to predict...

Removal of polycyclic aromatic hydrocarbons in aqueous environment by chemical treatments: a review.

Science.gov (United States)

Rubio-Clemente, Ainhoa; Torres-Palma, Ricardo A; Peñuela, Gustavo A

2014-04-15

Due to their carcinogenic, mutagenic and teratogenic potential, the removal of polycyclic aromatic hydrocarbons (PAHs) from aqueous environment using physical, biological and chemical processes has been studied by several researchers. This paper reviews the current state of knowledge concerning PAHs including their physico-chemical properties, input sources, occurrence, adverse effects and conventional and alternative chemical processes applied for their removal from water. The mechanisms and reactions involved in each treatment method are reported, and the effects of various variables on the PAH degradation rate as well as the extent of degradation are also discussed. Extensive literature analysis has shown that an effective way to perform the conversion and mineralization of this type of substances is the application of advanced oxidation processes (AOPs). Furthermore, combined processes, particularly AOPs coupled with biological treatments, seem to be one of the best solutions for the treatment of effluents containing PAHs. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of mini-LIA and primary experiments

International Nuclear Information System (INIS)

Cheng Cheng; Liao Shuqing; Zheng Shuxin; Lin Yuzheng; Tang Chuanxiang; Jing Xiaobing; Mu Fan; Pan Haifeng; Zhang Kaizhi; Shi Jinshui; Deng Jianjun

2009-01-01

Mini-LIA is a miniature of a linear induction accelerator developed by China Academy of Engineering Physics and Tsinghua University in 2007. It has been constructed with a thermionic cathode in an electron injector and a metglas core in the induction accelerator cavities. A double-pulsed electron beam was produced for the first time in China on the Mini-LIA with a thermionic cathode in the electron gun and a metglas core in the induction accelerator cavities. A double-pulsed beam current of more than 1.1A was obtained on condition of 80 kV double-pulsed high voltage produced by pulsed power system supplying to the injector and accelerating modules. Some primary experiments for measuring the parameters of Mini-LIA has been performed, and some beam characterizations of Mini-LIA are presented. Further improvement is underway. (authors)

Mini lathe machine converted to CNC

Directory of Open Access Journals (Sweden)

Alexandru Morar

2012-06-01

Full Text Available This paper presents the adaptation of a mechanical mini-lathing machine to a computerized numerical control (CNC lathing machine. This machine is composed of a ASIST mini-lathe and a two-degrees-of-freedom XZ stage designed specifically for this application. The whole system is controlled from a PC using adequate CNC control software.

On-line database of the spectral properties of polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

Malloci, Giuliano; Joblin, Christine; Mulas, Giacomo

2007-01-01

We present an on-line database of computed molecular properties for a large sample of polycyclic aromatic hydrocarbons in four charge states: -1, 0, +1, and +2. At present our database includes 40 molecules ranging in size from naphthalene and azulene (C 10 H 8 ) up to circumovalene (C 66 H 20 ). We performed our calculations in the framework of the density functional theory (DFT) and the time-dependent DFT to obtain the most relevant molecular parameters needed for astrophysical applications. For each molecule in the sample, our database presents in a uniform way the energetic, rotational, vibrational, and electronic properties. It is freely accessible on the web at (http://astrochemistry.ca.astro.it/database/) and (http://www.cesr.fr/~joblin/database/)

Photorefractive IR-spectrum composites prepared from polyimide and ruthenium(II) tetra-15-crown-5-phthalocyaninate with axially coordinated triethylenediamine molecules

International Nuclear Information System (INIS)

Vannikov, A.V.; Grishina, A.D.; Gorbunova, Yu.G.; Enakieva, Yu.Yu.; Krivenko, T.V.; Savel'ev, V.V.; Tsivadze, A.Yu.

2006-01-01

Photoelectric, non-linear optical, and photorefractive properties of aromatic polyimine doped with ruthenium(II) complex with tetra-15-crown-5-phthalocyanine and axially coordinated triethylenediamine molecules, (R 4 Pc)Ru(TED) 2 , where R 4 Pc 2- and TED denote 4,5,4',5',4'',5'',4''',5'''-tetrakis-(1,4,7,10,13- pentaoxatridecamethylene)phthalocyaninate ion and triethylenediamine molecule, respectively, were studied. It is established that supramolecular ensembles on the basis of the complex make an aromatic polyimide layer photoelectrically sensitive to 1064-nm Nd : YAG laser radiation, exhibit third-order susceptibility, and, consequently, impart photorefractive properties to the polymer layer at this wavelength [ru

Incorporating Inquiry into Upper-Level Homework Assignments: The Mini-Journal

Science.gov (United States)

Whittington, A. G.; Speck, A. K.; Witzig, S. B.; Abell, S. K.

2009-12-01

The U.S. National Science Education Standards provide guidelines for teaching science through inquiry, where students actively develop their understanding of science by combining scientific knowledge with reasoning and thinking skills. Inquiry activities include reading scientific literature, generating hypotheses, designing and carrying out investigations, interpreting data, and formulating conclusions. Inquiry-based instruction emphasizes questions, evidence, and explanation, the essential features of inquiry. As part of an NSF-funded project, “CUES: Connecting Undergraduates to the Enterprise of Science,” new inquiry-based homework materials were developed for two upper-level classes at the University of Missouri: Geochemistry (required for Geology majors), and Solar System Science (open to seniors and graduate students, co-taught and cross-listed between Geology and Physics & Astronomy). We engage students in inquiry-based learning by presenting homework exercises as “mini-journal” articles that follow the format of a scientific journal article, including a title, authors, abstract, introduction, methods, results, discussion and citations to peer-reviewed literature. The mini-journal provides a scaffold and serves as a springboard for students to develop and carry out their own follow-up investigation. They then present their findings in the form of their own mini-journal. Mini-journals replace traditional homework problem sets with a format that more directly reflects and encourages scientific practice. Students are engaged in inquiry-based homework which encompass doing, thinking, and communicating, while the minijournal allows the instructor to contain lines of inquiry within the limits posed by available resources. In the examples we present, research is conducted via spreadsheet modeling, where the students develop their own spreadsheets. The key differences between the old and new formats include (i) the active participation of the students in

Detection of dementia in primary care: comparison of the original and a modified Mini-Cog Assessment with the Mini-Mental State Examination.

Science.gov (United States)

Kamenski, Gustav; Dorner, Thomas; Lawrence, Kitty; Psota, Georg; Rieder, Anita; Schwarz, Franz; Sepandj, Asita; Spiegel, Wolfgang; Strotzka, Stefan

2009-12-01

Background Dementia is considered widely under-detected in primary care, and general practitioners (GPs) frequently ask for easy to use tools to assist in its early detection.Aim To determine the degree of correlation between the Mini-Cog Assessment (Mini-Cog) as performed by GPs and the Mini-Mental State Examination (MMSE).Design of study This was a prospective study (2005, 2006) comparing two cognitive screening instruments.Setting Ten general practices in Austria, with patients with a hitherto undiagnosed suspicion of dementia seen consecutively.Method Sensitivity, specificity and positive and negative predictive values (PPVs and NPVs) of the Mini-Cog (applying both a colour-coded and the original rating method) were assessed for degree of correlation with the MMSE. In phase one GPs examined patients suspected of having dementia using the Mini-Cog; in phase two a neurologist retested them applying the MMSE, a clock-drawing test (CDT) and a routine clinical examination. A questionnaire on the practicability of the Mini-Cog was answered by GPs.Results Of the 107 patients who participated 86 completed the whole study protocol. The Mini-Cog, as performed by the ten GPs, displayed a sensitivity of 0.85 (95% CI: 0.71, 0.98), a specificity of 0.58 (95% CI: 0.46, 0.71), a PPV of 0.47 (95% CI: 0.33, 0.61) and an NPV of 0.90 (95% CI: 0.80, 0.99) as against the MMSE carried out by neurologists. The GPs judged the Mini-Cog useful and time saving.Conclusion The Mini-Cog has a high sensitivity and acceptable specificity in the general practice setting and has proved to be a practicable tool for the diagnosis of dementia in primary care.

Human mini-guts: new insights into intestinal physiology and host-pathogen interactions.

Science.gov (United States)

In, Julie G; Foulke-Abel, Jennifer; Estes, Mary K; Zachos, Nicholas C; Kovbasnjuk, Olga; Donowitz, Mark

2016-11-01

The development of indefinitely propagating human 'mini-guts' has led to a rapid advance in gastrointestinal research related to transport physiology, developmental biology, pharmacology, and pathophysiology. These mini-guts, also called enteroids or colonoids, are derived from LGR5 + intestinal stem cells isolated from the small intestine or colon. Addition of WNT3A and other growth factors promotes stemness and results in viable, physiologically functional human intestinal or colonic cultures that develop a crypt-villus axis and can be differentiated into all intestinal epithelial cell types. The success of research using human enteroids has highlighted the limitations of using animals or in vitro, cancer-derived cell lines to model transport physiology and pathophysiology. For example, curative or preventive therapies for acute enteric infections have been limited, mostly due to the lack of a physiological human intestinal model. However, the human enteroid model enables specific functional studies of secretion and absorption in each intestinal segment as well as observations of the earliest molecular events that occur during enteric infections. This Review describes studies characterizing these human mini-guts as a physiological model to investigate intestinal transport and host-pathogen interactions.

Prospects for Antineutrino Running at MiniBooNE

OpenAIRE

Wascko, M. O.

2006-01-01

MiniBooNE began running in antineutrino mode on 19 January, 2006. We describe the sensitivity of MiniBooNE to LSND-like nuebar oscillations and outline a program of antineutrino cross-section measurements necessary for the next generation of neutrino oscillation experiments. We describe three independent methods of constraining wrong-sign (neutrino) backgrounds in an antineutrino beam, and their application to the MiniBooNE antineutrino analyses.

Microwave spectra, molecular structure, and aromatic character of 4a,8a-azaboranaphthalene

Energy Technology Data Exchange (ETDEWEB)

Pejlovas, Aaron M.; Daly, Adam M.; Kukolich, Stephen G. [Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (United States); Ashe, Arthur J. [Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055 (United States)

2016-03-21

The microwave spectra for seven unique isotopologues of 4a,8a-azaboranaphthalene [hereafter referred to as BN-naphthalene] were measured using a pulsed-beam Fourier transform microwave spectrometer. Spectra were obtained for the normal isotopologues with {sup 10}B, {sup 11}B, and all unique single {sup 13}C and the {sup 15}N isotopologue (with {sup 11}B), in natural abundance. The rotational, centrifugal distortion and quadrupole coupling constants determined for the {sup 11}B{sup 14}N isotopologue are A = 3042.712 75(43) MHz, B = 1202.706 57(35) MHz, C = 862.220 13(35) MHz, D{sub J} = 0.06(1) kHz, 1.5χ{sub aa} ({sup 14}N) = 2.5781(61) MHz, 0.25(χ{sub bb} − χ{sub cc}) ({sup 14}N) = − 0.1185(17) MHz, 1.5χ{sub aa} (11B) = − 3.9221(75) MHz, and 0.25(χ{sub bb} − χ{sub cc}) ({sup 11}B) = − 0.9069(24) MHz. The experimental inertial defect is Δ = − 0.159 amu Å{sup 2}, which is consistent with a planar structure for the molecule. The B—N bond length from the experimentally determined structure is 1.47 Å, which indicates π-bonding character between the B and N. The measured quadrupole coupling strengths provide important and useful information about the bonding, orbital occupancy, and aromatic character for this aromatic molecule. Extended Townes-Dailey analyses were used to determine the B and N electron sp{sup 2}-hybridized and p-orbital occupations. These results are compared with electron orbital occupations from the natural bond orbital option in theoretical calculations. From the analyses, it was determined that BN-naphthalene has aromatic character similar to that of other N-containing aromatics. The results are compared with similar results for B—N bonding in 1,2-dihydro-1,2-azaborine and BN-cyclohexene. Accurate and precise structural parameters were obtained from the microwave measurements on seven isotopologues and from high-level G09 calculations.

Arrested Handedness and Disordered Stacking in Crystals of the Pre-helical Molecule 7,8-Dioxa[6]helicene

DEFF Research Database (Denmark)

Krebs, Frederik C; Faldt, André; Thorup, Niels

1999-01-01

A characteristic feature of many molecules of biological origin is their 'handedness' or enantiomorphism. L. Pasteur prepared and separated enantiomeric crystals in 1848.(1) Since then, manifestations of symmetry breaking have attracted much attention.(2,3) Simple models of the new horseshoe shaped...... molecule, 7,8-dioxa[6]helicene ( 1), indicated a low inversion barrier between helical enantiomers. A quasi-planar pi system capable of stack formation was also observed. The molecule in question is a so-called helicene. Aromatic helicenes and heteroaromatic helicenes constitute a class of molecules...

Adsorption behaviour of aromatic in different activated carbon: (Frendlich and Langmuir models)

International Nuclear Information System (INIS)

Nouri, S.; Haghseresht, F.; Lu, Max

2001-01-01

Adsorption behavior of p-Cresol, Benzoic acid and nitrobenzene on the two different activated carbons was carried out at 301 K and at controlled ph conditions. In acidic conditions, well below the pK a of all solutes, it was observed that the adsorbate solubility and the electron density of its aromatic ring were the influencing factors on the extent of the adsorption by affecting the extent of London dispersion forces. In higher solution ph conditions, on the other hand, it was found that the electrostatic forces played a significant role on the extent on adsorption. The Effect of ph must be considered from its combined effects on the carbon surface and on the solute molecules. It was found that the uptake of the molecular form of the aromatic solute was dependent on the substituents of the aromatic ring. Adsorption of the solutes in higher ph values was found to be dependent on the concentration of anionic form of the solutes. All isotherms on the F 100 and S E I were fitted into Langmuir and Freundlich isotherm Equations, respectively to find the relative factors

Detecting aromatic compounds on planetary surfaces using ultraviolet time-resolved fluorescence spectroscopy

Science.gov (United States)

Eshelman, E.; Daly, M. G.; Slater, G.; Cloutis, E.

2018-02-01

Many aromatic organic molecules exhibit strong and characteristic fluorescence when excited with ultraviolet radiation. As laser excitation in the ultraviolet generates both fluorescence and resonantly enhanced Raman scattering of aromatic vibrational modes, combined Raman and fluorescence instruments have been proposed to search for organic compounds on Mars. In this work the time-resolved fluorescence of a suite of 24 compounds composed of 2-5 ringed alternant, non-alternant, and heterocyclic PAHs was measured. Fluorescence instrumentation with similar specifications to a putative flight instrument was capable of observing the fluorescence decay of these compounds with a sub-ns resolution. Incorporating time-resolved capabilities was also found to increase the ability to discriminate between individual PAHs. Incorporating time-resolved fluorescence capabilities into an ultraviolet gated Raman system intended for a rover or lander can increase the ability to detect and characterize PAHs on planetary surfaces.

Synthesis and characterization of aromatic self-assembled monolayers containing methylene and ethyleneglycol entities by means of sum-frequency generation spectroscopy

International Nuclear Information System (INIS)

Dreesen, L.; Sartenaer, Y.; Peremans, A.; Thiry, P.A.; Humbert, C.; Grugier, J.; Marchand-Brynaert, J.

2006-01-01

We use infrared-visible sum-frequency generation (SFG) spectroscopy in order to investigate the adsorption properties on Pt(111) of molecules having CH 3 -C 6 H 4 -(O-CH 2 -CH 2 ) n -O-(CH 2 ) m -SH as general chemical formula. We synthesized three molecules defined by the values m = 5 n = 4, m = 11 n = 4, m = 11 n = 8 and characterized them by Nuclear Magnetic Resonance spectroscopy. Thanks to spectroscopic measurements, we show that these molecules build self-assembled monolayers on Pt(111). First, the weak SFG signals arising from the ad-layer indicate low order and surface coverage of the substrate by these molecules. Next, the vibrational fingerprints of the aforementioned molecules are determined between 2825 and 3125 cm - 1 and the observed SFG spectral features are ascribed on the basis of the analysis of shorter and simpler molecules (1-dodecanethiol, 4-methylbenzenethiol and CH 3 -C 6 H 4 -O-(CH 2 ) 11 -SH) also adsorbed on Pt(111). The occurrence of methylene vibration modes indicates a significant amount of chain defects whatever the n and m numbers are. Finally, the identification of a particular vibration mode, characteristic of the aromatic ring, enables us to qualitatively discuss the effect of the number of methylene and ethylene glycol entities on its orientation. More precisely, higher these numbers, more tilted (with respect to the substrate normal) the aromatic ring plane is

A mini-UAV VTOL Platform for Surveying Applications

Directory of Open Access Journals (Sweden)

Kuldeep Rawat

2014-05-01

Full Text Available In this paper we discuss implementation of a mini-Unmanned Aerial Vehicle (UAV vertical take-off and landing (VTOL platform for surveying activities related to highway construction. Recent advances in sensor and communication technologies have allowed scaling sizes of unmanned aerial platforms, and explore them for tasks that are economical and safe over populated or inhabited areas. In highway construction the capability of mini-UAVs to survey in hostile and/or hardly accessible areas can greatly reduce human risks. The project focused on developing a cost effective, remotely controlled, fuel powered mini-UAV VTOL (helicopter platform with certain payload capacity and configuration and demonstrated its use in surveying and monitoring activities required for highway planning and construction. With an on-board flight recorder global positioning system (GPS device, memory storage card, telemetry, inertial navigation sensors, and a video camera the mini-UAV can record flying coordinates and relay live video images to a remote ground receiver and surveyor. After all necessary integration and flight tests were done the mini-UAV helicopter was tested to operate and relay video from the areas where construction was underway. The mini-UAV can provide a platform for a range of sensors and instruments that directly support the operational requirements of transportation sector.

Designing a mini subcritical nuclear reactor; Diseno de un mini reactor nuclear subcritico

Energy Technology Data Exchange (ETDEWEB)

Escobedo G, C. R.; Vega C, H. R.; Davila H, V. M., E-mail: rafelaescobedo@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Jardin Juarez 147, Col. Centro, 98000 Zacatecas, Zac. (Mexico)

2015-10-15

In this work the design of a mini subcritical nuclear reactor formed by means of light water moderator, uranium as fuel, and isotopic neutron source of {sup 239}PuBe was carried out. The design was done by Monte Carlo methods with the code MCNP5 in which uranium was modeled in an array of concentric holes cylinders of 8.5, 14.5, 20.5, 26.5, 32.5 cm of internal radius and 3 cm of thickness, 36 cm of height. Different models were made from a single fuel cylinder (natural uranium) to five. The neutron source of {sup 239}PuBe was situated in the center of the mini reactor; in each arrangement was used water as moderator. Cross sections libraries Endf/Vi were used and the number of stories was large enough to ensure less uncertainty than 3%. For each case the effective multiplication factor k{sub e}-f{sub f}, the amplification factor and the power was calculated. Outside the mini reactor the ambient dose equivalent H (10) was calculated for different cases. The value of k{sub eff}, the amplification factor and power are directly related to the number of cylinders of uranium as fuel. Although the average energy of the neutrons {sup 239}PuBe is between 4.5 and 5 MeV in the case of the mini reactor for a cylinder, in the neutron spectrum the presence of thermal neutrons does not exist, so that produced fissions are generated with fast neutrons, and in designs of two and three rings the neutron spectra shows the presence of thermal neutrons, however the fissions are being generated with fast neutrons. Finally in the four and five cases the amount of moderator is enough to thermalized the neutrons and thereby produce the fission. The maximum value for k{sub eff} was 0.82; this value is very close to the assembly of Universidad Autonoma de Zacatecas generating a k{sub eff} of 0.86. According to the safety and radiation protection standards for the design of mini reactor of one, two and three cylinders they comply with the established safety, while designs of four and five

[The "Mini-ICF-Rating for Mental Disorders (Mini-ICF-P)". A short instrument for the assessment of disabilities in mental disorders].

Science.gov (United States)

Linden, M; Baron, S

2005-06-01

Supplementary to the description of diseases at symptom level, the International Classification of Functioning, Disability and Health (ICF), edited by the WHO, for the first time enables a systematic description also at the level of disabilities and impairments. The Mini-ICF-Rating for Mental Disorders (Mini-ICF-P) is a short observer rating instrument for the assessment of disabilities, especially with regard to occupational functioning. The Mini-ICF-P was first evaluated empirically in 125 patients of a Department of Behavioural Medicine and Psychosomatics. Parallel-test reliability was r = 0.59. Correlates were found with cognitive and motivational variables and duration of sick leave from work. In summary, the Mini-ICF-P is a quick and practicable instrument.

Mini International Neuropsychiatric Interview (MINI: validação de entrevista breve para diagnóstico de transtornos mentais

Directory of Open Access Journals (Sweden)

Amorim Patrícia

2000-01-01

Full Text Available Objetivos: O MINI é uma entrevista diagnóstica padronizada breve (15-30 minutos, compatível com os critérios do DSM-III-R/IV e da CID-10, que é destinada à utilização na prática clínica e na pesquisa em atenção primária e em psiquiatria, e pode ser utilizada por clínicos após um treinamento rápido (de 1 a 3 horas. A versão Plus do MINI, mais detalhada, gera diagnósticos positivos dos principais transtornos psicóticos e do humor do DSM-IV. Este artigo apresenta os resultados de quatro estudos de validação do instrumento, realizados na Europa e nos EUA. Métodos: Os estudos 1 (França e 2 (EUA testaram a confiabilidade -entre avaliadores e teste-reteste -da versão DSM-III-R do MINI (n=84, sendo 42 pacientes psiquiátricos de cada centro e sua validade com relação ao CIDI (n=346, sendo 296 pacientes psiquiátricos e 50 controles e ao SCID-P (n=370, sendo 308 pacientes psiquiátricos e 62 controles, respectivamente. O estudo 3 testou a validade de diagnósticos gerados por clínicos gerais usando o MINI (DSM-IV com relação aos diagnósticos clínicos habituais de psiquiatras, em 409 pacientes de centros de atenção primária de quatro países (França, Espanha, Itália e Reino Unido. O estudo 4 testou a confiabilidade entre avaliadores (n=20 pacientes psiquiátricos e a validade dos módulos Transtornos Psicóticos, Depressão e Mania do MINI Plus - DSM IV (n=104 pacientes psiquiátricos com relação a dois critérios de referência: diagnósticos do CIDI e diagnósticos clínicos de psiquiatras. Análises quantitativas (índices de concordância e de validade e qualitativas (razões de discordância foram realizadas. Resultados: Os índices de confiabilidade do MINI (estudos 1 e 2 e do MINI Plus (estudo 4 foram globalmente satisfatórios. Comparados a vários critérios de referência (CIDI, SCID-P, opinião de peritos, em diferentes contextos (unidades psiquiátricas e centros de atenção primária, o MINI e o MINI

PV-hybrid and mini-grid

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

Within the 5th European PV-hybrid and mini-grid conference 29th and 30th April, 2010 in Tarragona (Spain) the following lectures were held: (1) Overview of IEA PVPS Task 11 PV-hybrid systems within mini grids; (2) Photovoltaic revolution for deployment in developing countries; (3) Legal and financial conditions for the sustainable operation of mini-grids; (4) EU instruments to promote renewable energies in developing countries; (5) PV hybridization of diesel electricity generators: Conditions of profitability and examples in differential power and storage size ranges; (6) Education suit of designing PV hybrid systems; (7) Sustainable renewable energy projects for intelligent rural electrification in Laos, Cambodia and Vietnam; (8) Techno-economic feasibility of energy supply of remote villages in Palestine by PV systems, diesel generators and electric grid (Case studies: Emnazeil and Atouf villages); (9) Technical, economical and sustainability considerations of a solar PV mini grid as a tool for rural electrification in Uganda; (10) Can we rate inverters for rural electrification on the basis of energy efficiency?; (11) Test procedures for MPPT charge controllers characterization; (12) Energy storage for mini-grid stabilization; (13) Redox flow batteries - Already an alternative storage solution for hybrid PV mini-grids?; (14) Control methods for PV hybrid mini-grids; (15) Partial AC-coupling in mini-grids; (15) Normative issues of small wind turbines in PV hybrid systems; (16) Communication solutions for PV hybrid systems; (17) Towards flexible control and communication of mini-grids; (18) PV/methanol fuel cell hybrid system for powering a highway security variable message board; (19) Polygeneration smartgrids: A solution for the supply of electricity, potable water and hydrogen as fuel for transportation in remote Areas; (20) Implementation of the Bronsbergen micro grid using FACDS; (21) A revisited approach for the design of PV wind hybrid systems; (22

Subgap Two-Photon States in Polycyclic Aromatic Hydrocarbons: Evidence for Strong Electron Correlations

OpenAIRE

Aryanpour, K.; Roberts, A.; Sandhu, A.; Rathore, R.; Shukla, A.; Mazumdar, S.

2013-01-01

Strong electron correlation effects in the photophysics of quasi-one-dimensional $\\pi$-conjugated organic systems such as polyenes, polyacetylenes, polydiacetylenes, etc., have been extensively studied. Far less is known on correlation effects in two-dimensional $\\pi$-conjugated systems. Here we present theoretical and experimental evidence for moderate repulsive electron-electron interactions in a number of finite polycyclic aromatic hydrocarbon molecules with $D_{6h}$ symmetry. We show that...

Calculation of average molecular parameters, functional groups, and a surrogate molecule for heavy fuel oils using 1H and 13C NMR spectroscopy

KAUST Repository

Abdul Jameel, Abdul Gani; Elbaz, Ayman M.; Emwas, Abdul-Hamid M.; Roberts, William L.; Sarathy, Mani

2016-01-01

Heavy fuel oil (HFO) is primarily used as fuel in marine engines and in boilers to generate electricity. Nuclear Magnetic Resonance (NMR) is a powerful analytical tool for structure elucidation and in this study, 1H NMR and 13C NMR spectroscopy were used for the structural characterization of 2 HFO samples. The NMR data was combined with elemental analysis and average molecular weight to quantify average molecular parameters (AMPs), such as the number of paraffinic carbons, naphthenic carbons, aromatic hydrogens, olefinic hydrogens, etc. in the HFO samples. Recent formulae published in the literature were used for calculating various derived AMPs like aromaticity factor 〖(f〗_a), C/H ratio, average paraffinic chain length (¯n), naphthenic ring number 〖(R〗_N), aromatic ring number〖 (R〗_A), total ring number〖 (R〗_T), aromatic condensation index (φ) and aromatic condensation degree (Ω). These derived AMPs help in understanding the overall structure of the fuel. A total of 19 functional groups were defined to represent the HFO samples, and their respective concentrations were calculated by formulating balance equations that equate the concentration of the functional groups with the concentration of the AMPs. Heteroatoms like sulfur, nitrogen, and oxygen were also included in the functional groups. Surrogate molecules were finally constructed to represent the average structure of the molecules present in the HFO samples. This surrogate molecule can be used for property estimation of the HFO samples and also serve as a surrogate to represent the molecular structure for use in kinetic studies.

Calculation of average molecular parameters, functional groups, and a surrogate molecule for heavy fuel oils using 1H and 13C NMR spectroscopy

KAUST Repository

Abdul Jameel, Abdul Gani

2016-04-22

Heavy fuel oil (HFO) is primarily used as fuel in marine engines and in boilers to generate electricity. Nuclear Magnetic Resonance (NMR) is a powerful analytical tool for structure elucidation and in this study, 1H NMR and 13C NMR spectroscopy were used for the structural characterization of 2 HFO samples. The NMR data was combined with elemental analysis and average molecular weight to quantify average molecular parameters (AMPs), such as the number of paraffinic carbons, naphthenic carbons, aromatic hydrogens, olefinic hydrogens, etc. in the HFO samples. Recent formulae published in the literature were used for calculating various derived AMPs like aromaticity factor 〖(f〗_a), C/H ratio, average paraffinic chain length (¯n), naphthenic ring number 〖(R〗_N), aromatic ring number〖 (R〗_A), total ring number〖 (R〗_T), aromatic condensation index (φ) and aromatic condensation degree (Ω). These derived AMPs help in understanding the overall structure of the fuel. A total of 19 functional groups were defined to represent the HFO samples, and their respective concentrations were calculated by formulating balance equations that equate the concentration of the functional groups with the concentration of the AMPs. Heteroatoms like sulfur, nitrogen, and oxygen were also included in the functional groups. Surrogate molecules were finally constructed to represent the average structure of the molecules present in the HFO samples. This surrogate molecule can be used for property estimation of the HFO samples and also serve as a surrogate to represent the molecular structure for use in kinetic studies.

The Mini-Cog, Clock Drawing Test, and the Mini-Mental State Examination in a German memory clinic: specificity of separation dementia from depression.

Science.gov (United States)

Milian, Monika; Leiherr, Anna-Maria; Straten, Guido; Müller, Stephan; Leyhe, Thomas; Eschweiler, Gerhard W

2013-01-01

The aim of this study was to assess the specificities of the Mini-Cog, the Clock Drawing Test (CDT), and the Mini-Mental State Examination (MMSE) against depression and healthy controls in a German Memory Clinic. Furthermore, we analyzed the specificities of all three screening instruments in dependence of actual depression severity. Data from 142 depressed elderly, 438 dementia patients, and 64 healthy controls were retrospectively analyzed. The CDT and an extraction of the three-item recall of the MMSE were used to constitute the Mini-Cog algorithm. Depression severity was rated by either the Beck Depression Inventory (BDI) or the Geriatric Depression Scale (GDS) depending on the age of the patients. The Mini-Cog achieved a specificity of 79.6% against depressed elderly and 100.0% against healthy subjects (p Mini-Cog and the CDT, but also showed the lowest sensitivity for the detection of dementia. Surprisingly, the depression severity had no effect on the specificity of the Mini-Cog and the CDT, only the MMSE was susceptible for the depression severity. Although the MMSE showed higher specificities, the weighting between the sensitivities and specificities in all tests prove again the Mini-Cog as a short, valid, and sensitive screening tool.

The Raman and vibronic activity of intermolecular vibrations in aromatic-containing complexes and clusters

International Nuclear Information System (INIS)

Maxton, P.M.; Schaeffer, M.W.; Ohline, S.M.; Kim, W.; Venturo, V.A.; Felker, P.M.

1994-01-01

Theoretical and experimental results pertaining to the excitation of intermolecular vibrations in the Raman and vibronic spectra of aromatic-containing, weakly bound complexes and clusters are reported. The theoretical analysis of intermolecular Raman activity is based on the assumption that the polarizability tensor of a weakly bound species is given by the sum of the polarizability tensors of its constituent monomers. The analysis shows that the van der Waals bending fundamentals in aromatic--rare gas complexes may be expected to be strongly Raman active. More generally, it predicts strong Raman activity for intermolecular vibrations that involve the libration or internal rotation of monomer moieties having appreciable permanent polarizability anisotropies. The vibronic activity of intermolecular vibrations in aromatic-rare gas complexes is analyzed under the assumption that every vibronic band gains its strength from an aromatic-localized transition. It is found that intermolecular vibrational excitations can accompany aromatic-localized vibronic excitations by the usual Franck--Condon mechanism or by a mechanism dependent on the librational amplitude of the aromatic moiety during the course of the pertinent intermolecular vibration. The latter mechanism can impart appreciable intensity to bands that are forbidden by rigid-molecule symmetry selection rules. The applicability of such rules is therefore called into question. Finally, experimental spectra of intermolecular transitions, obtained by mass-selective, ionization-detected stimulated Raman spectroscopies, are reported for benzene--X (X=Ar, --Ar 2 , N 2 , HCl, CO 2 , and --fluorene), fluorobenzene--Ar and --Kr, aniline--Ar, and fluorene--Ar and --Ar 2 . The results support the conclusions of the theoretical analyses and provide further evidence for the value of Raman methods in characterizing intermolecular vibrational level structures

Two-dimensional character of internal rotation of furfural and other five-member heterocyclic aromatic aldehydes.

Science.gov (United States)

Bataev, Vadim A; Pupyshev, Vladimir I; Godunov, Igor A

2016-05-15

The features of nuclear motion corresponding to the rotation of the formyl group (CHO) are studied for the molecules of furfural and some other five-member heterocyclic aromatic aldehydes by the use of MP2/6-311G** quantum chemical approximation. It is demonstrated that the traditional one-dimensional models of internal rotation for the molecules studied have only limited applicability. The reason is the strong kinematic interaction of the rotation of the CHO group and out-of-plane CHO deformation that is realized for the molecules under consideration. The computational procedure based on the two-dimensional approximation is considered for low lying vibrational states as more adequate to the problem. Copyright © 2016 Elsevier B.V. All rights reserved.

Cyano-containing ionic liquids for the extraction of aromatic hydrocarbons from an aromatic/aliphatic mixture

NARCIS (Netherlands)

Meindersma, G.W.; Haan, de A.B.

2012-01-01

Ionic liquids can replace conventional solvents in aromatic/aliphatic extractions, if they have higher aromatic distribution coefficients and higher or similar aromatic/aliphatic selectivities. Also physical properties, such as density and viscosity, must be taken into account if a solvent is

Carbazole Scaffold in Medicinal Chemistry and Natural Products: A Review from 2010-2015.

Science.gov (United States)

Tsutsumi, Lissa S; Gündisch, Daniela; Sun, Dianqing

2016-01-01

9H-carbazole is an aromatic molecule that is tricyclic in nature, with two benzene rings fused onto a 5-membered pyrrole ring. Obtained from natural sources or by synthetic routes, this scaffold has gained much interest due to its wide range of biological activity upon modifications, including antibacterial, antimalarial, anticancer, and anti-Alzheimer properties. This review reports a survey of the literature on carbazole-containing molecules and their medicinal activities from 2010 through 2015. In particular, we focus on their in vitro and in vivo activities and summarize structure-activity relationships (SAR), mechanisms of action, and/or cytotoxicity/selectivity findings when available to provide future guidance for the development of clinically useful agents from this template.

Pendant unit effect on electron tunneling in U-shaped molecules

International Nuclear Information System (INIS)

Liu Min; Chakrabarti, Subhasis; Waldeck, David H.; Oliver, Anna M.; Paddon-Row, Michael N.

2006-01-01

The electron transfer reactions of three U-shaped donor-bridge-acceptor molecules with different pendant groups have been studied in different solvents as a function of temperature. Analysis of the electron transfer kinetics in nonpolar and weakly polar solvents provides experimental reaction Gibbs energies that are used to parameterize a molecular solvation model. This solvation model is then used to predict energetic parameters in the electron transfer rate constant expression and allow the electronic coupling between the electron donor and electron acceptor groups to be determined from the rate data. The U-shaped molecules differ by alkylation of the aromatic pendant group, which lies in the 'line-of-sight' between the donor and acceptor groups. The findings show that the electronic coupling through the pendant group is similar for these molecules

Metal-metal bonding and aromaticity in [M2(NHCHNH)3]2 (μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh).

Science.gov (United States)

Yan, Xiuli; Meng, Lingpeng; Sun, Zheng; Li, Xiaoyan

2016-02-01

The nature of M-M bonding and aromaticity of [M2(NHCHNH)3]2(μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh) was investigated using atoms in molecules (AIM) theory, electron localization function (ELF), natural bond orbital (NBO) and molecular orbital analysis. These analyses led to the following main conclusions: in [M2(NHCHNH)3]2(μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh), the Nb-Nb, Ru-Ru, and Rh-Rh bonds belong to "metallic" bonds, whereas Mo-Mo and Tc-Tc drifted toward the "dative" side; all these bonds are partially covalent in character. The Nb-Nb, Mo-Mo, and Tc-Tc bonds are stronger than Ru-Ru and Rh-Rh bonds. The M-M bonds in [M2(NHCHNH)3]2(μ-S)2 are stronger than those in [M2(NHCHNH)3]2(μ-O)2 for M = Nb, Mo, Tc, and Ru. The NICS(1)ZZ values show that all of the studied molecules, except [Ru2(NHCHNH)3]2(μ-O)2, are aromaticity molecules. O-bridged compounds have more aromaticity than S-bridged compounds. Graphical Abstract Left Molecular graph, and right electron localization function (ELF) isosurface of [M2(NHCHNH)3]2(μ-E)2(E = O, S; M = Nb, Mo, Tc, Ru, Rh).

Solution processable organic polymers and small molecules for bulk-heterojunction solar cells: A review

International Nuclear Information System (INIS)

Sharma, G. D.

2011-01-01

Solution processed bulk heterojunction (BHJ) organic solar cells (OSCs) have gained wide interest in past few years and are established as one of the leading next generation photovoltaic technologies for low cost power production. Power conversion efficiencies up to 6% and 6.5% have been reported in the literature for single layer and tandem solar cells, respectively using conjugated polymers. A recent record efficiency about 8.13% with active area of 1.13 cm 2 has been reported. However Solution processable small molecules have been widely applied for photovoltaic (PV) devices in recent years because they show strong absorption properties, and they can be easily purified and deposited onto flexible substrates at low cost. Introducing different donor and acceptor groups to construct donor--acceptor (D--A) structure small molecules has proved to be an efficient way to improve the properties of organic solar cells (OSCs). The power conversion efficiency about 4.4 % has been reported for OSCs based on the small molecules. This review deals with the recent progress of solution processable D--A structure small molecules and discusses the key factors affecting the properties of OSCs based on D--A structure small molecules: sunlight absorption, charge transport and the energy level of the molecules.

Is coronene better described by Clar's aromatic π-sextet model or by the AdNDP representation?

Science.gov (United States)

Kumar, Anand; Duran, Miquel; Solà, Miquel

2017-07-05

The bonding patterns in coronene are complicated and controversial as denoted by the lack of consensus of how its electronic structure should be described. Among the different proposed descriptions, the two most representative are those generated by Clar's aromatic π-sextet and adaptative natural density partitioning (AdNDP) models. Quantum-chemical calculations at the density functional theory level are performed to evaluate the model that gives a better representation of coronene. To this end, we analyse the molecular structure of coronene, we estimate the aromaticity of its inner and outer rings using various local aromaticity descriptors, and we assess its chemical reactivity from the study of the Diels-Alder reaction with cyclopentadiene. Results obtained are compared with those computed for naphthalene and phenanthrene. Our conclusion is that Clar's π-sextet model provides the representation of coronene that better describes the physicochemical behavior of this molecule. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The reproductive and developmental toxicity of High Flash Aromatic Naphtha.

Science.gov (United States)

McKee, R H; Wong, Z A; Schmitt, S; Beatty, P; Swanson, M; Schreiner, C A; Schardein, J L

1990-01-01

Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent--High Flash Aromatic Naphtha. A program was initiated to assess the toxicological properties of High Flash Aromatic Naphtha since there may be human exposure through inhalation or external body contact. The current study was conducted to assess the potential for developmental toxicity in the mouse and for reproductive toxicity in the rat. In the developmental toxicity study in CD-1 mice, exposure of dams by inhalation to near lethal levels (1500 ppm) resulted in fetal mortality, reduced weight, delayed ossification, and an increased incidence of cleft palate. At 500 ppm, a level at which maternal weight gain was slightly reduced, fetal weight gain was also reduced, but there was no other evidence of developmental effects. The lowest exposure level (100 ppm) did not cause any maternal or developmental toxicity. There was no consistent evidence of reproductive toxicity in rats, even at exposure levels which resulted in significantly reduced parental weight gain. In addition, when parental exposure was stopped on GD (gestation day) 20, birth weights as well as postnatal survival were generally similar to control values, even in the 1500 ppm exposure group. Postnatal weight gain was also similar to controls early in weaning, but, if maternal exposure was reinitiated, weight gain was reduced in the high exposure group. However, when exposure was continued until delivery, pups in the high exposure group exhibited reduced litter size, birth weight and poor survival. Thus it was likely that the reduction in fetal weight

Ultrasound assisted intensification of enzyme activity and its properties: a mini-review.

Science.gov (United States)

Nadar, Shamraja S; Rathod, Virendra K

2017-08-22

Over the last decade, ultrasound technique has emerged as the potential technology which shows large applications in food and biotechnology processes. Earlier, ultrasound has been employed as a method of enzyme inactivation but recently, it has been found that ultrasound does not inactivate all enzymes, particularly, under mild conditions. It has been shown that the use of ultrasonic treatment at appropriate frequencies and intensity levels can lead to enhanced enzyme activity due to favourable conformational changes in protein molecules without altering its structural integrity. The present review article gives an overview of influence of ultrasound irradiation parameters (intensity, duty cycle and frequency) and enzyme related factors (enzyme concentration, temperature and pH) on the catalytic activity of enzyme during ultrasound treatment. Also, it includes the effect of ultrasound on thermal kinetic parameters and Michaelis-Menten kinetic parameters (k m and V max ) of enzymes. Further, in this review, the physical and chemical effects of ultrasound on enzyme have been correlated with thermodynamic parameters (enthalpy and entropy). Various techniques used for investigating the conformation changes in enzyme after sonication have been highlighted. At the end, different techniques of immobilization for ultrasound treated enzyme have been summarized.

Robot therapy: a new approach for mental healthcare of the elderly - a mini-review.

Science.gov (United States)

Shibata, Takanori; Wada, Kazuyoshi

2011-01-01

Mental healthcare of elderly people is a common problem in advanced countries. Recently, high technology has developed robots for use not only in factories but also for our living environment. In particular, human-interactive robots for psychological enrichment, which provide services by interacting with humans while stimulating their minds, are rapidly spreading. Such robots not only simply entertain but also render assistance, guide, provide therapy, educate, enable communication, and so on. Robot therapy, which uses robots as a substitution for animals in animal-assisted therapy and activity, is a new application of robots and is attracting the attention of many researchers and psychologists. The seal robot named Paro was developed especially for robot therapy and was used at hospitals and facilities for elderly people in several countries. Recent research has revealed that robot therapy has the same effects on people as animal therapy. In addition, it is being recognized as a new method of mental healthcare for elderly people. In this mini review, we introduce the merits and demerits of animal therapy. Then we explain the human-interactive robot for psychological enrichment, the required functions for therapeutic robots, and the seal robot. Finally, we provide examples of robot therapy for elderly people, including dementia patients. Copyright © 2010 S. Karger AG, Basel.

NMR detects molecular interactions of graphene with aromatic and aliphatic hydrocarbons in water

Science.gov (United States)

Bichenkova, Elena V.; Raju, Arun P. A.; Burusco, Kepa K.; Kinloch, Ian A.; Novoselov, Kostya S.; Clarke, David J.

2018-03-01

Polyaromatic carbon is widely held to be strongly diamagnetic and hydrophobic, with textbook van der Waals and ‘π-stacked’ binding of hydrocarbons, which disrupt their self-assembled supramolecular structures. The NMR of organic molecules sequestered by polyaromatic carbon is expected to be dominated by shielding from the orbital diamagnetism of π electrons. We report the first evidence of very different polar and magnetic behavior in water, wherein graphene remained well-dispersed after extensive dialysis and behaved as a 1H-NMR-silent ghost. Magnetic effects dominated the NMR of organic structures which interacted with graphene, with changes in spin-spin coupling, vast increase in relaxation, line broadening and decrease in NMR peak heights when bound to graphene. However, the interactions were weak, reversible and did not disrupt organic self-assemblies reliant on hydrophobic ‘π-stacking’, even when substantially sequestered on the surface of graphene by the high surface area available. Interacting assemblies of aromatic molecules retained their strongly-shielded NMR signals and remained within self-assembled structures, with slower rates of diffusion from association with graphene, but with no further shielding from graphene. Binding to graphene was selective for positively-charged organic assemblies, weaker for non-aromatic and negligible for strongly-negatively-charged molecules, presumably repelled by a negative zeta potential of graphene in water. Stronger binders, or considerable excess of weaker binders readily reversed physisorption, with no evidence of structural changes from chemisorption. The fundamental nature of these different electronic interactions between organic and polyaromatic carbon is considered with relevance to electronics, charge storage, sensor, medical, pharmaceutical and environmental research.

Validation and cultural adaptation of the Arabic versions of the Mini-Mental Status Examination - 2 and Mini-Cog test.

Science.gov (United States)

Albanna, Mohammad; Yehya, Arij; Khairi, Abdalla; Dafeeah, Elnour; Elhadi, Abdelsalam; Rezgui, Lamia; Al Kahlout, Shahada; Yousif, Adil; Uthman, Basim; Al-Amin, Hassen

2017-01-01

The elderly population is increasing around the world, and the prevalence of dementia increases with age. Hence, it is expected that the number of people with dementia will increase significantly in the coming years. The Mini-Mental Status Examination - 2 (MMSE-2) and Mini-Cog are widely used tests to screen for dementia. These scales have good reliability and validity and are easy to administer in clinical and research settings. The purpose of this study was to validate the Arabic versions of MMSE-2 and Mini-Cog. These scales were assessed against the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision ( DSM-IV-TR ) criteria for dementia, as the gold standard. The standard versions of the MMSE-2 and Mini-Cog were translated to Arabic following the back-translation method. Then, a trained rater administered these tests to 134 Arab elderly aged >60 years. A physician, blind to the results of these two tests, assessed the participants for vascular dementia or probable Alzheimer's disease, based on the DSM-IV-TR criteria. The sample included 67.2% Qataris. The mean age was 74.86 years (standard deviation =7.71), and 61.9% did not attend school. The mean of the adjusted scores of MMSE-2 based on age and education level was 19.60 (standard deviation =6.58). According to DSM-IV-TR , 17.2% of the participants had dementia. Sensitivity and specificity of the MMSE-2 and the Mini-Cog together were 71.4% and 61.6%, respectively, which were better than those of each test alone. Together, the Arabic versions of MMSE-2 and Mini-Cog are good screening tools for cognitive impairment in Arabs.

Aromater i drikkevand

DEFF Research Database (Denmark)

Nyeland, B. A.; Hansen, A. B.

DMU har den 10. Juni 1997 afholdt en præstationsprøvning: Aromater i drikkevand. Der deltog 21 laboratorier i præstationsprøvningen. Prøvningen omfattede 6 vandige prøver og 6 ampuller indeholdende 6 aromater. Laboratorierne spikede de tilsendte vandprøver med indholdet fra ampullerne...

Self-Assessment Based Mini-After Action Review (SAMAAR) Methodology: Developmental Application to Division Artillery Staff Training

National Research Council Canada - National Science Library

Mirabella, Angelo

1998-01-01

.... In the SAMAAR approach, trainees, at the end of an exercise day or shift fill out rating forms to assess the units training progress and then convene with their completed forms to participate in a mini-AAR...

Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

Science.gov (United States)

Smith, R.E.; Dolbeare, F.A.

1980-10-21

Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes. No Drawings

Recent Studies on the Aromaticity and Antiaromaticity of Planar Cyclooctatetraene

Directory of Open Access Journals (Sweden)

Masahiko Iyoda

2010-02-01

Full Text Available Cyclooctatetraene (COT, the first 4nπ-electron system to be studied, adopts an inherently nonplanar tub-shaped geometry of D2d symmetry with alternating single and double bonds, and hence behaves as a nonaromatic polyene rather than an antiaromatic compound. Recently, however, considerable 8π-antiaromatic paratropicity has been shown to be generated in planar COT rings even with the bond alternated D4h structure. In this review, we highlight recent theoretical and experimental studies on the antiaromaticity of hypothetical and actual planar COT. In addition, theoretically predicted triplet aromaticity and stacked aromaticity of planar COT are also briefly described.

Ionic Liquids as Benign Solvents for the Extraction of Aromatics

International Nuclear Information System (INIS)

Hossain, Md. Anwar; Lee, Jeesun; Kim, Dai Hyun; Nguyen, Dinh Quan; Cheong, Minserk; Kim, Hoon Sik

2012-01-01

Ionic liquids (ILs) have been extensively investigated as promising alternatives to conventional organic solvents such as sulfolane and N,N-dimethylformamide for the selective extraction of aromatic hydrocarbons from the C 6 -C 10 hydrocarbon mixtures produced from the cracking processes of naphtha and light oils. The most important advantage of ILs over conventional organic solvents is that they are immiscible with aliphatic hydrocarbons, and thus the back extraction of ILs from the raffinate phases and top hydrocarbon-rich layers is not necessary. In this paper, a brief review on the state of the art in the utilization of ILs for aromatics separation is presented

The antitumor effects of geraniol: Modulation of cancer hallmark pathways (Review).

Science.gov (United States)

Cho, Minsoo; So, Insuk; Chun, Jung Nyeo; Jeon, Ju-Hong

2016-05-01

Geraniol is a dietary monoterpene alcohol that is found in the essential oils of aromatic plants. To date, experimental evidence supports the therapeutic or preventive effects of geraniol on different types of cancer, such as breast, lung, colon, prostate, pancreatic, and hepatic cancer, and has revealed the mechanistic basis for its pharmacological actions. In addition, geraniol sensitizes tumor cells to commonly used chemotherapy agents. Geraniol controls a variety of signaling molecules and pathways that represent tumor hallmarks; these actions of geraniol constrain the ability of tumor cells to acquire adaptive resistance against anticancer drugs. In the present review, we emphasize that geraniol is a promising compound or chemical moiety for the development of a safe and effective multi-targeted anticancer agent. We summarize the current knowledge of the effects of geraniol on target molecules and pathways in cancer cells. Our review provides novel insight into the challenges and perspectives with regard to geraniol research and to its application in future clinical investigation.

Reasons for mini-implants failure: choosing installation site should be valued!

Directory of Open Access Journals (Sweden)

Alberto Consolaro

2014-04-01

Full Text Available Mini-implant loss is often associated with physical and mechanical aspects that result from choosing an inappropriate placement site. It is worth highlighting that: a Interdental alveolar bone crests are flexible and deformable. For this reason, they may not offer the ideal absolute anchorage. The more cervical the structures, the more delicate they are, thus offering less physical support for mini-implant placement; b Alveolar bone crests of triangular shape are more deformable, whereas those of rectangular shape are more flexible; c The bases of the alveolar processes of the maxilla and the mandible are not flexible, for this reason, they are more likely to receive mini-implants; d The more cervical a mini-implant is placed, the higher the risk of loss; the more apical a mini-implant is placed, the better its prognosis will be; e 3D evaluations play a major role in planning the use of mini-implants. Based on the aforementioned considerations, the hypotheses about mini-implant loss are as follows: 1 Deflection of maxillary and mandibular alveolar processes when mini-implants are more cervically placed; 2 Mini-implants placed too near the periodontal ligament, with normal intra-alveolar tooth movement; 3 Low bone density, low thickness and low alveolar bone volume; 4 Low alveolar cortical bone thickness; 5 Excessive pressure inducing trabecular bone microfracture; 6 Sites of higher anatomical weakness in the mandible and the maxilla; 7 Thicker gingival tissue not considered when choosing the mini-implant.

Virtual laboratory of electrical mini-grids with distributed generation

International Nuclear Information System (INIS)

Menezes Ramos, Vanessa; Barros Galhardo, Marcos André; Oliveira Barbosa, Claudomiro Fábio de; Tavares Pinho, João

2015-01-01

This paper presents a computing tool called Virtual Laboratory de Minirredes (Virtual Laboratory of Mini-grids). Using the virtual environment of the developed tool, it is possible to make remote connection/disconnection of switches and loads (resistive, inductive, capacitive and non-linear) at strategic points of the electric mini-grid with hybrid distributed generation systems (solar photovoltaic-diesel). The mini-grid has a length of about 1 km and is installed in the test area of the Grupo de Estudios e Desenvolvimento de Alternativas Exergética (GEDAE) of the Universidade Federal do Pará, located in the city of Belém, Pará, Brazil. The developed tool has communication functions with electric parameters transducers and programmable logic controllers (PLCs). This communication enables the opening and closing of contactors, resulting in different settings for the mini-grid. In addition to that, based on the proposed configuration by the user, the real-time operation status of mini-grid is presented in a graphic interface (for example, monitored electric parameters, distributed generators connected, status of disconnected switches, etc.) and the acquired data is stored. The use of the computing tool also focuses on the construction of a database, in order to obtain knowledge about the mini-grid performance under various conditions that can be set, depending on the operational strategy adopted, based on the choice of the layout, loads and power sources used in the mini-grid. (full text)

Mini AERCam Inspection Robot for Human Space Missions

Science.gov (United States)

Fredrickson, Steven E.; Duran, Steve; Mitchell, Jennifer D.

2004-01-01

The Engineering Directorate of NASA Johnson Space Center has developed a nanosatellite-class free-flyer intended for future external inspection and remote viewing of human spacecraft. The Miniature Autonomous Extravehicular Robotic Camera (Mini AERCam) technology demonstration unit has been integrated into the approximate form and function of a flight system. The spherical Mini AERCam free flyer is 7.5 inches in diameter and weighs approximately 10 pounds, yet it incorporates significant additional capabilities compared to the 35 pound, 14 inch AERCam Sprint that flew as a Shuttle flight experiment in 1997. Mini AERCam hosts a full suite of miniaturized avionics, instrumentation, communications, navigation, imaging, power, and propulsion subsystems, including digital video cameras and a high resolution still image camera. The vehicle is designed for either remotely piloted operations or supervised autonomous operations including automatic stationkeeping and point-to-point maneuvering. Mini AERCam is designed to fulfill the unique requirements and constraints associated with using a free flyer to perform external inspections and remote viewing of human spacecraft operations. This paper describes the application of Mini AERCam for stand-alone spacecraft inspection, as well as for roles on teams of humans and robots conducting future space exploration missions.

Water droplet accumulation and motion in PEM (Proton Exchange Membrane) fuel cell mini-channels

International Nuclear Information System (INIS)

Carton, J.G.; Lawlor, V.; Olabi, A.G.; Hochenauer, C.; Zauner, G.

2012-01-01

Effective water management is one of the key strategies for improving low temperature PEM (Proton Exchange Membrane) fuel cell performance and durability. Phenomena such as membrane dehydration, catalyst layer flooding, mass transport and fluid flow regimes can be affected by the interaction, distribution and movement of water in flow plate channels. In this paper a literature review is completed in relation to PEM fuel cell water flooding. It is clear that droplet formation, movement and interaction with the GDL (Gas Diffusion Layer) have been studied extensively. However slug formation and droplet accumulation in the flow channels has not been analysed in detail. In this study, a CFD (Computational Fluid Dynamic) model and VOF (Volume of Fluid) method is used to simulate water droplet movement and slug formation in PEM fuel cell mini-channels. In addition, water slug visualisation is recorded in ex situ PEM fuel cell mini-channels. Observation and simulation results are discussed with relation to slug formation and the implications to PEM fuel cell performance. -- Highlights: ► Excess water in mini-channels from the collision and coalescence of droplets can directly form slugs in PEM fuel cells. ► Slugs can form at low flow rates so increasing the flow rate can reduce the size and frequency of slugs. ► One channel of a double serpentine mini-channel may become blocked due to the redistribution of airflow and pressure caused by slug formation. ► Correct GDL and mini-channel surface coatings are essential to reduce slug formation and stagnation. ► Having geometry changes (bends and steps) in the flow fields can disrupt slug movement and avoid channel blockages.

Mini-chamber, an advanced protection concept for NIF

International Nuclear Information System (INIS)

Peterson, P.F.; Scott, J.M.

1996-01-01

Inertial confinement fusion (ICF) target debris and ablated near-target materials pose the primary threat to the National Ignition Facility (NIF) final optics debris shields, as well as a major challenge in future inertial fusion energy (IFE) power plants. This work discusses a NIF 'mini-chamber,' designed to mitigate the debris threat. Although the NIF base-line design protects against debris using a frost-protected target positioner and refractory first-wall coatings, the mini-chamber provides important flexibility in three areas: debris-shield protection from beyond-design basis shots (i.e. heavy hohlraums, special diagnostics, shields); fielding of large experiments with significant surface ablation; and studying key ablation and gas-dynamics issues for liquid-wall IFE power plants. Key mini-chamber modeling results are presented, followed by discussion of equipment requirements for fielding a NIF mini-chamber. 7 refs., 3 figs

Dibenzoheptazethrene isomers with different biradical characters: An exercise of clar's aromatic sextet rule in singlet biradicaloids

KAUST Repository

Sun, Zhe

2013-12-04

Clar\\'s aromatic sextet rule has been widely used for the prediction of the reactivity and stability of polycyclic aromatic hydrocarbons with a closed-shell electronic configuration. Recent advances in open-shell biradicaloids have shown that the number of aromatic sextet rings plays an important role in determination of their ground states. In order to test the validity of this rule in singlet biradicaloids, the two soluble and stable dibenzoheptazethrene isomers DBHZ1 and DBHZ2 were prepared by different synthetic approaches and isolated in crystalline form. These two molecules have different numbers of aromatic sextet rings in their respective biradical resonance forms and thus are expected to exhibit varied singlet biradical character. This assumption was verified by different experimental methods, including nuclear magnetic resonance (NMR), electron spin resonance (ESR), superconducting quantum interference device (SQUID), steady-state and transient absorption spectroscopy (TA), and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. DBHZ2, with more aromatic sextet rings in the biradical form, was demonstrated to possess greater biradical character than DBHZ1; as a result, DBHZ2 exhibited an intense one-photon absorption (OPA) in the near-infrared region (λabs max = 804 nm) and a large two-photon absorption (TPA) cross-section (σ(2)max = 2800 GM at 1600 nm). This investigation together with previous studies indicates that Clar\\'s aromatic sextet rule can be further extended to the singlet biradicaloids to predict their ground states and singlet biradical characters. © 2013 American Chemical Society.

Mini-Implants: New Possibilities in Interdisciplinary Treatment Approaches

Directory of Open Access Journals (Sweden)

Biju Sebastian

2014-01-01

Full Text Available The introduction of mini-implants has broadened the range of tooth movements possible by fixed appliance therapy alone. The limits of fixed orthodontic treatment have become more a matter of facial appearance than anchorage. Many complex cases which would previously have required surgery or functional appliances can now be treated with fixed appliance therapy using mini-implants. A mutilated dentition case where mini-implants were used to provide anchorage for intrusion of molars and retraction of anterior teeth is reported here to illustrate this point.

Extracting physics of life at the molecular level: A review of single-molecule data analyses.

Science.gov (United States)

Colomb, Warren; Sarkar, Susanta K

2015-06-01

Studying individual biomolecules at the single-molecule level has proved very insightful recently. Single-molecule experiments allow us to probe both the equilibrium and nonequilibrium properties as well as make quantitative connections with ensemble experiments and equilibrium thermodynamics. However, it is important to be careful about the analysis of single-molecule data because of the noise present and the lack of theoretical framework for processes far away from equilibrium. Biomolecular motion, whether it is free in solution, on a substrate, or under force, involves thermal fluctuations in varying degrees, which makes the motion noisy. In addition, the noise from the experimental setup makes it even more complex. The details of biologically relevant interactions, conformational dynamics, and activities are hidden in the noisy single-molecule data. As such, extracting biological insights from noisy data is still an active area of research. In this review, we will focus on analyzing both fluorescence-based and force-based single-molecule experiments and gaining biological insights at the single-molecule level. Inherently nonequilibrium nature of biological processes will be highlighted. Simulated trajectories of biomolecular diffusion will be used to compare and validate various analysis techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

Immobilization of small molecules and proteins by radio-derivatized polystyrene

International Nuclear Information System (INIS)

Varga, J.M.; Fritsch, P.

1990-01-01

When molded polystyrene (PS) products (e.g., microtiter plates) or latex particles are irradiated with high-energy (1-10 Mrads) gamma rays in the presence of nonpolymerizable small molecules such as aromatic amines, some of these molecules incorporate into PS, which leads to the formation of radio-derivatized PS (RDPS). Two classes of RDPS can be identified regarding their ability for immobilization of biologically important molecules: (1) reactive RDPS that are able to form covalent bonds with molecules such as proteins without the help of cross-linkers, and (2) functionalized RDPS that can be used for the immobilization of molecules with activators (e.g., carbodiimides) or cross-linkers. The method can be used for the production of low-noise supports for binding assays. Most of the RDPS can be produced without impairment of the optical quality of PS, making derivatized microtiter plates suitable for colorimetric assays. The principle can be applied for the preparation of affinity sorbents, e.g., for high-performance affinity chromatography and for the immobilization of enzymes using latex PS particles

Energy efficient mini bars in hotel rooms; Energieffektive minibarer til hotelvaerelser

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-12-15

The project 'Energy-efficient mini bars for hotel rooms' is carried out from February December 2005. The project is financed by Elfor's PSO funds and also by the participants in the project, HORESTA and Teknologisk Institut. Mini bars consume up to 10% of the total electricity costs of a hotel. Therefore, the energy consumption of mini bars has been brought into focus in this project. The existing mini bar market has been analysed and measurements have been carried out on the type of mini bars that are used most often. In that way, energy consumption, net volume, energy efficiency, energy labelling, noise level and cooling capacity have been determined. In the course of the project, mini bars from IndelB, Domestic and Vibocold have been tested. With regard to energy consumption, the test results showed large deviations from the consumption stated by the manufacturer. Only 1 of the 6 tested mini bars received an energy label B - the others were labelled with F or G. Therefore, there is a great potential for developing more energy efficient mini bars. A list covering the energy consumption, energy labelling, noise level etc. of the tested mini bars and a guide to new purchases can be found on HORESTA's homepage www.horesta.dk. (au)

Occurrence of Functional Molecules in the Flowers of Tea (Camellia sinensis Plants: Evidence for a Second Resource

Directory of Open Access Journals (Sweden)

Yiyong Chen

2018-03-01

Full Text Available Tea (Camellia sinensis is an important crop, and its leaves are used to make the most widely consumed beverage, aside from water. People have been using leaves from tea plants to make teas for a long time. However, less attention has been paid to the flowers of tea plants, which is a waste of an abundant resource. In the past 15 years, researchers have attempted to discover, identify, and evaluate functional molecules from tea flowers, and have made insightful and useful discoveries. Here, we summarize the recent investigations into these functional molecules in tea flowers, including functional molecules similar to those in tea leaves, as well as the preponderant functional molecules in tea flowers. Tea flowers contain representative metabolites similar to those of tea leaves, such as catechins, flavonols, caffeine, and amino acids. The preponderant functional molecules in tea flowers include saponins, polysaccharides, aromatic compounds, spermidine derivatives, and functional proteins. We also review the safety and biological functions of tea flowers. Tea flower extracts are proposed to be of no toxicological concern based on evidence from the evaluation of mutagenicity, and acute and subchronic toxicity in rats. The presence of many functional metabolites in tea flowers indicates that tea flowers possess diverse biological functions, which are mostly related to catechins, polysaccharides, and saponins. Finally, we discuss the potential for, and challenges facing, future applications of tea flowers as a second resource from tea plants.

Development on mini X-ray diode

International Nuclear Information System (INIS)

Jiang Shaoen; Sun Kexu; Peng Nengling; Huang Tianxuan; Cui Yanli; Yi Rongqing; Chen Jiusen

2004-01-01

The mini X-ray diode (M-XRD) was developed, and was used in mini soft X-ray spectrometer. Compared with traditional XRD, M-XRD's volume reduces to 1/30. M-XRD's property was experimentally examined on Shenguang II laser facility. The experimental results indicated that the temporal response and sensitivity of M-XRD are basically consistent with traditional XRD. The equivalent circuit of XRD was analyzed, and its response time and linear saturated current were calculated. (authors)

Revisiting the stability of mini-implants used for orthodontic anchorage

Directory of Open Access Journals (Sweden)

Chung-Chen Jane Yao

2015-11-01

Conclusion: This study revealed that once the dental surgeon becomes familiar with the procedure, the stability of orthodontic mini-implants depends on the type of mini-implant, age of the patient, implantation site, and the healing time of the mini-implant. Miniplates are a more feasible anchorage system when miniscrews fail repeatedly.

Berkeley mini-collider

International Nuclear Information System (INIS)

Schroeder, L.S.

1984-06-01

The Berkeley Mini-Collider, a heavy-ion collider being planned to provide uranium-uranium collisions at T/sub cm/ less than or equal to 4 GeV/nucleon, is described. The central physics to be studied at these energies and our early ideas for a collider detector are presented

THE FAR-INFRARED SPECTROSCOPY OF VERY LARGE NEUTRAL POLYCYCLIC AROMATIC HYDROCARBONS

International Nuclear Information System (INIS)

Ricca, Alessandra; Bauschlicher, Charles W.; Mattioda, Andrew L.; Boersma, Christiaan; Allamandola, Louis J.

2010-01-01

Here we report the computed far-infrared (FIR) spectra of neutral polycyclic aromatic hydrocarbon (PAH) molecules containing at least 82 carbons up to 130 carbons and with shapes going from compact round and oval-type structures to rectangular and to trapezoidal. The effects of size and shape on the FIR band positions and intensities are discussed. Using FIR data from the NASA Ames PAH IR Spectroscopic Database Version 1.1, we generate synthetic spectra that support the suggestion that the 16.4, 17.4, and 17.8 μm bands arise from PAHs.

A-π-D-π-A Electron-Donating Small Molecules for Solution-Processed Organic Solar Cells: A Review.

Science.gov (United States)

Wang, Zhen; Zhu, Lingyun; Shuai, Zhigang; Wei, Zhixiang

2017-11-01

Organic solar cells based on semiconducting polymers and small molecules have attracted considerable attention in the last two decades. Moreover, the power conversion efficiencies for solution-processed solar cells containing A-π-D-π-A-type small molecules and fullerenes have reached 11%. However, the method for designing high-performance, photovoltaic small molecules still remains unclear. In this review, recent studies on A-π-D-π-A electron-donating small molecules for organic solar cells are introduced. Moreover, the relationships between molecular properties and device performances are summarized, from which inspiration for the future design of high performance organic solar cells may be obtained. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antifungal activity of polycyclic aromatic hydrocarbons against Ligninolytic fungi

Directory of Open Access Journals (Sweden)

Memić Mustafa

2011-01-01

Full Text Available Environmental contamination by polycyclic aromatic hydrocarbons (PAHs has caused increasing concern because of their known, or suspected, carcinogenic and mutagenic effects. Polycyclic aromatic hydrocarbons occurring in the environment are usually the result of the incomplete combustion of carbon containing materials. The main sources of severe PAHs contamination in soil come from fossil fuels, i.e. production or use of fossil fuels or their products, such as coal tar and creosote. Creosote is used as a wood preservation for railway ties, bridge timbers, pilling and large-sized lumber. It consists mainly of PAHs, phenol and cresol compounds that cause harmful health effects. Research on biodegradation has shown that a special group of microorganisms, the white-rot fungi and brown-rot fungi, has a remarkable potential to degrade PAHs. This paper presents a study of the antifungal activity of 12 selected PAHs against two ligninolytic fungi Hypoxylon fragiforme (white rot and Coniophora puteana (brown rot. The antifungal activity of PAHs was determined by the disc-diffusion method by measuring the diameter of the zone of inhibition. The results showed that the antifungal activity of the tested PAHs (concentration of 2.5 mmol/L depends on the their properties such as molar mass, solubility in water, values of log Kow, ionization potential and Henry’s Law constant as well as number of aromatic rings, molecule topology or pattern of ring linkage. Among the 12 investigated PAHs, benzo(k fluoranthene with five rings, and pyrene with four cyclic condensed benzene rings showed the highest antifungal activity.

Regional factor of sustainable development of rural settlements of Kalna and Minićevo at the foot of the Stara Planina mountain

Directory of Open Access Journals (Sweden)

Aranđelović Miloš

2016-01-01

Full Text Available Developmental potential of rural settlements of Kalna and Minićevo should be reviewed in the wider context of the area in which they are located. The natural resources of Stara Planina mountain, as a special purpose area focused on tourism and agriculture, represent the basic components for sustainable development of the mentioned settlements. The heritage of autochthonus, traditional rural architecture and sacral buildings, together with natural resources potentials, represent attractors for the development of a specific form of rural tourism. This research paper presents an analysis of the options for the development of rural tourism in the territory of Knjaževac municipality, aimed at sustainable development of rural settlements of Kalna and Minićevo. The basic idea of the paper is for Kalna and Minićevo to become the centres towards which the population of smaller surrounding villages will gravitate: towards Kalna as a potential tourism centre and towards Minićevo as a transit tourist settlement with accompanying public and other services. The purpose of the paper is not to offer a solution that would completely eliminate economic and demographic changes, but to review different options for the development of rural settlements that could keep up with modern social needs.

Biotin conjugated organic molecules and proteins for cancer therapy: A review.

Science.gov (United States)

Maiti, Santanu; Paira, Priyankar

2018-02-10

The main transporter for biotin is sodium dependent multivitamin transporter (SMVT), which is overexpressed in various aggressive cancer cell lines such as ovarian (OV 2008, ID8), leukemia (L1210FR), mastocytoma (P815), colon (Colo-26), breast (4T1, JC, MMT06056), renal (RENCA, RD0995), and lung (M109) cancer cell lines. Furthermore, its overexpression was found higher to that of folate receptor. Therefore, biotin demand in the rapidly growing tumors is higher than normal tissues. Several biotin conjugated organic molecules has been reported here for selective delivery of the drug in cancer cell. Biotin conjugated molecules are showing higher fold of cytotoxicity in biotin positive cancer cell lines than the normal cell. Nanoparticles and polymer surface modified drugs and biotin mediated cancer theranostic strategy was highlighted in this review. The cytotoxicity and selectivity of the drug in cancer cells has enhanced after biotin conjugation. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Perlindungan Hukum Hak Kekayaan Intelektual (Hki) Dalam Waralaba Retail Mini Market Di Yogyakarta Mini Market Di Yogyakarta

OpenAIRE

Hariyanto Hariyanto, S.H., M.KN

2009-01-01

The Law Protection Intellectual Property Right in Mini Market Retail Franchise in YogyakartaFranchise business is more happening in Indonesia. This fast development indicates an interesting investment which on the same time helps the business subjects in starting their own business with a low risk. The franchise business which commonly stable is retail business. One of retail business which serves the main needs and daily needs is mini market Alfamart and Indomaret.This research aims to ident...

Graphical prediction of quantum interference-induced transmission nodes in functionalized organic molecules

DEFF Research Database (Denmark)

Markussen, Troels; Stadler, Robert; Thygesen, Kristian Sommer

2011-01-01

Quantum interference (QI) in molecular transport junctions can lead to dramatic reductions of the electron transmission at certain energies. In a recent work [Markussen et al., Nano Lett., 2010, 10, 4260] we showed how the presence of such transmission nodes near the Fermi energy can be predicted...... solely from the structure of a conjugated molecule when the energies of the atomic pz orbitals do not vary too much. Here we relax the assumption of equal on-site energies and generalize the graphical scheme to molecules containing different atomic species. We use this diagrammatic scheme together......, the transmission functions of functionalized aromatic molecules generally display a rather complex nodal structure due to the interplay between molecular topology and the energy of the side group orbital....

Determination of Quantum Chemistry Based Force Fields for Molecular Dynamics Simulations of Aromatic Polymers

Science.gov (United States)

Jaffe, Richard; Langhoff, Stephen R. (Technical Monitor)

1995-01-01

Ab initio quantum chemistry calculations for model molecules can be used to parameterize force fields for molecular dynamics simulations of polymers. Emphasis in our research group is on using quantum chemistry-based force fields for molecular dynamics simulations of organic polymers in the melt and glassy states, but the methodology is applicable to simulations of small molecules, multicomponent systems and solutions. Special attention is paid to deriving reliable descriptions of the non-bonded and electrostatic interactions. Several procedures have been developed for deriving and calibrating these parameters. Our force fields for aromatic polyimide simulations will be described. In this application, the intermolecular interactions are the critical factor in determining many properties of the polymer (including its color).

Orthodontic mechanics using mini-implant measured by FBG

Science.gov (United States)

Trannin, Pamela G.; Milczewski, Maura S.; de Oliveira, Walmir; Guariza Filho, Odilon; Lopes, Stephani C. P. S.; Kalinowski, Hypolito J.

2015-07-01

The magnitude of the force generated during orthodontic mechanics anchored in mini-implant in a maxilla model was analyzed. Data was collected during the insertion of the mini-implant and at the moment of applying forces to the structure of the maxilla and dentition. To obtain quantitative results, the Fibre Bragg Gratings (FBG) were inserted in an elastomeric material reproducing a maxilla model. It was observed levels of forces of approximately 3,78N next to the root of first premolar by the insertion of the mini-implant and different levels of the force to different orthodontic mechanics applied on the dental system.

Initial validation of the Mini-Mental Adjustment to Cancer (Mini-MAC) scale: study of Portuguese end-of-life cancer patients.

Science.gov (United States)

Pereira, Filomena Moreira Pinto; Santos, Célia Samarina Vilaça de Brito

2014-10-01

The Mini-Mental Adjustment to Cancer Scale (Mini-MAC) is a 29-item instrument designed to evaluate the responses developed by cancer patients during their mental adjustment to diagnosis and treatment. This study aims to validate the Mini-Mental Adjustment to Cancer Scale (Mini-MAC) translated and adapted to the Portuguese language and culture, in end-of-life cancer patients receiving palliative care. The instrument was administered to 346 Portuguese end-of-life cancer patients, receiving care through outpatient visits or admitted into palliative care units, without cognitive symptoms and with symptoms under control. A cross-sectional validation study using orthogonal rotation through the varimax method followed by convergent and discriminant validity. The analysis of the main components confirms the existence of five factors, demonstrating the validity of the construct, with good internal consistency in the subscales and Cronbach's alpha values between 0.78 and 0.93. Good test-retest reliability was also found, and r values for subscales ranged from 0.62 to 0.99. The instrument proved to be a reliable, valid and sensitive measure in the study of mental adjustment of Portuguese end-of-life patients with cancer receiving palliative care. Nurses can use the Mini-MAC Scale in research and clinical practice in order to evaluate the mental adjustment of Portuguese end-of-life cancer patients receiving palliative care. Copyright © 2014 Elsevier Ltd. All rights reserved.

A novel approach of solid waste management via aromatization using multiphase catalytic pyrolysis of waste polyethylene.

Science.gov (United States)

Gaurh, Pramendra; Pramanik, Hiralal

2018-01-01

A new and innovative approach was adopted to increase the yield of aromatics like, benzene, toluene and xylene (BTX) in the catalytic pyrolysis of waste polyethylene (PE). The BTX content was significantly increased due to effective interaction between catalystZSM-5 and target molecules i.e., lower paraffins within the reactor. The thermal and catalytic pyrolysis both were performed in a specially designed semi-batch reactor at the temperature range of 500 °C-800 °C. Catalytic pyrolysis were performed in three different phases within the reactor batch by batch systematically, keeping the catalyst in A type- vapor phase, B type- liquid phase and C type- vapor and liquid phase (multiphase), respectively. Total aromatics (BTX) of 6.54 wt% was obtained for thermal pyrolysis at a temperature of 700 °C. In contrary, for the catalytic pyrolysis A, B and C types reactor arrangement, the aromatic (BTX) contents were progressively increased, nearly 6 times from 6.54 wt% (thermal pyrolysis) to 35.06 wt% for C-type/multiphase (liquid and vapor phase). The pyrolysis oil were characterized using GC-FID, FT-IR, ASTM distillation and carbon residue test to evaluate its end use and aromatic content. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structural variations in aromatic 2π-electron three-membered rings ...

Indian Academy of Sciences (India)

Abstract. Structural variations of different 2π-aromatic three-membered ring systems of main group ele- ments, especially group 14 and 13 elements as compared to the classical description of cyclopropenyl cation has been reviewed in this article. The structures of heavier analogues as well as group 13 analogues of cyclo-.

Which hydrogen atom of toluene protonates PAH molecules in (+)-mode APPI MS analysis?

Science.gov (United States)

Ahmed, Arif; Ghosh, Manik Kumer; Choi, Myung Chul; Choi, Cheol Ho; Kim, Sunghwan

2013-03-01

A previous study (Ahmed, A. et al., Anal. Chem. 84, 1146-1151( 2012) reported that toluene used as a solvent was the proton source for polyaromatic hydrocarbon compounds (PAHs) that were subjected to (+)-mode atmospheric-pressure photoionization. In the current study, the exact position of the hydrogen atom in the toluene molecule (either a methyl hydrogen or an aromatic ring hydrogen) involved in the formation of protonated PAH ions was investigated. Experimental analyses of benzene and anisole demonstrated that although the aromatic hydrogen atom of toluene did not contribute to the formation of protonated anthracene, it did contribute to the formation of protonated acridine. Thermochemical data and quantum mechanical calculations showed that the protonation of anthracene by an aromatic ring hydrogen atom of toluene is endothermic, while protonation by a methyl hydrogen atom is exothermic. However, protonation of acridine by either an aromatic ring hydrogen or a methyl hydrogen atom of toluene is exothermic. The different behavior of acridine and anthracene was attributed to differences in gas-phase basicity. It was concluded that both types of hydrogen in toluene can be used for protonation of PAH compounds, but a methyl hydrogen atom is preferred, especially for non-basic compounds.

Maximum atmosphere at the Mini Atomiades

CERN Multimedia

Rachel Bray, Atomiades organizer team

2016-01-01

CERN Clubs Coordination Committee and CERN Staff Association host the ASCERI Mini Atomiades June 2016.   The CERN team won the tennis tournament for the Mini Atomiades 2016. (Photo: Erwin Van Hove) Over 180 participants from 10 different European Scientific Research Institutes came together on the first weekend of June in Divonne-les-Bains to take part in the ASCERI Sport & Science Mini Atomiades. Sports men and women from Belgium, Germany, France, Hungary, Russia and Switzerland battled it out in four different tournaments for medals, cups and, above all, lots of fun. The four disciplines included football, golf, tennis and a 10km race. CERN was victorious in tennis, golf and the men's and women's 10km, and despite the CERN football team putting up an excellent fight against some very strong teams they came almost last (we cannot win everything, can we?). But CERN were the clear winners for team spirit, community and camaraderie, as confirmed by all the comp...

Probing of miniPEGγ-PNA-DNA Hybrid Duplex Stability with AFM Force Spectroscopy.

Science.gov (United States)

Dutta, Samrat; Armitage, Bruce A; Lyubchenko, Yuri L

2016-03-15

Peptide nucleic acids (PNA) are synthetic polymers, the neutral peptide backbone of which provides elevated stability to PNA-PNA and PNA-DNA hybrid duplexes. It was demonstrated that incorporation of diethylene glycol (miniPEG) at the γ position of the peptide backbone increased the thermal stability of the hybrid duplexes (Sahu, B. et al. J. Org. Chem. 2011, 76, 5614-5627). Here, we applied atomic force microscopy (AFM) based single molecule force spectroscopy and dynamic force spectroscopy (DFS) to test the strength and stability of the hybrid 10 bp duplex. This hybrid duplex consisted of miniPEGγ-PNA and DNA of the same length (γ(MP)PNA-DNA), which we compared to a DNA duplex with a homologous sequence. AFM force spectroscopy data obtained at the same conditions showed that the γ(MP)PNA-DNA hybrid is more stable than the DNA counterpart, 65 ± 15 pN vs 47 ± 15 pN, respectively. The DFS measurements performed in a range of pulling speeds analyzed in the framework of the Bell-Evans approach yielded a dissociation constant, koff ≈ 0.030 ± 0.01 s⁻¹ for γ(MP)PNA-DNA hybrid duplex vs 0.375 ± 0.18 s⁻¹ for the DNA-DNA duplex suggesting that the hybrid duplex is much more stable. Correlating the high affinity of γ(MP)PNA-DNA to slow dissociation kinetics is consistent with prior bulk characterization by surface plasmon resonance. Given the growing interest in γ(MP)PNA as well as other synthetic DNA analogues, the use of single molecule experiments along with computational analysis of force spectroscopy data will provide direct characterization of various modifications as well as higher order structures such as triplexes and quadruplexes.

PRESSURE EFFECTS IN POLYCYCLIC AROMATIC NITROGENATED HETEROCYCLES (PANHs): DIAGNOSTIC QUALITIES AND COSMOBAROMETRY POTENTIAL

Energy Technology Data Exchange (ETDEWEB)

Montgomery, Wren; Sephton, Mark A., E-mail: w.montgomery@imperial.ac.uk [Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, Imperial College London SW7 2AZ (United Kingdom)

2016-03-01

The influence of polycyclic aromatic nitrogen heterocycles (PANHs), which have been suggested as contributors to the interstellar IR emission bands, on interstellar emission features is difficult to constrain because their infrared characteristics are strongly similar to those for polycyclic aromatic hydrocarbons (PAHs). One possible solution is to seek a means of visualizing the presence of PANHs that provides information that is distinct from that for PAHs. Although PANHs and PAHs have similar infrared characteristics in many settings, this relationship may not be universally maintained. We have used in situ high-pressure synchrotron-source Fourier transform infrared spectroscopy to determine that the responses of two representative molecules, acridine and anthracene, differ at high pressures (>ca. 1 GPa). Because there are a number of high-pressure environments that can be remotely observed by infrared spectroscopy, they represent a potential to glimpse the distribution of PANHs across the cosmos.

Influence of different implant materials on the primary stability of orthodontic mini-implants

OpenAIRE

Chin-Yun Pan; Szu-Ting Chou; Yu-Chuan Tseng; Yi-Hsin Yang; Chao-Yi Wu; Ting-Hsun Lan; Pao-Hsin Liu; Hong-Po Chang

2012-01-01

This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants w...

Gas-phase ion/molecule isotope-exchange reactions: methodology for counting hydrogen atoms in specific organic structural environments by chemical ionization mass spectrometry

International Nuclear Information System (INIS)

Hunt, D.F.; Sethi, S.K.

1980-01-01

Ion/molecule reactions are described which facilitate exchange of hydrogens for deuteriums in a variety of different chemical environments. Aromatic hydrogens in alkylbenzenes, oxygenated benzenes, m-toluidine, m-phenylenediamine, thiophene, and several polycyclic aromatic hydrocarbons and metallocenes are exchanged under positive ion CI conditions by using either D 2 O, EtOD, or ND 3 as the reagent gas. Aromatic hydrogens, benzylic hydrogens, and hydrogens on carbon adjacent to carbonyl groups suffer exchange under negative ion CI conditions in ND 3 , D 2 O, and EtOD, respectively. A possible mechanism for the exchange process is discussed. 1 figure, 2 tables

Aromaticidade: evolução histórica do conceito e critérios quantitativos Aromaticity: historical evolution of the concept and quantitative criteria

Directory of Open Access Journals (Sweden)

Giovanni Finoto Caramori

2009-01-01

Full Text Available In this paper the evolution of the concept of aromaticity is discussed. It considers not only historical aspects of the aromaticity concept but also the different criteria (theoretical and experimental that have appeared to explain the properties of the aromatic compounds. The topics range from the isolation of benzene by Faraday (1825 until the modern criteria based on geometries, magnetic properties, resonance energy (RE, aromatic stabilization energy (ASE, topological analyses, and others. A chronological separation of issues concerning aromaticity was made, splitting the definitions before and after the appearance of the quantum chemistry. This work reviews the concept of aromaticity.

Adsorption of organic molecules on mineral surfaces studied by first-principle calculations: A review.

Science.gov (United States)

Zhao, Hongxia; Yang, Yong; Shu, Xin; Wang, Yanwei; Ran, Qianping

2018-04-09

First-principle calculations, especially by the density functional theory (DFT) methods, are becoming a power technique to study molecular structure and properties of organic/inorganic interfaces. This review introduces some recent examples on the study of adsorption models of organic molecules or oligomers on mineral surfaces and interfacial properties obtained from first-principles calculations. The aim of this contribution is to inspire scientists to benefit from first-principle calculations and to apply the similar strategies when studying and tailoring interfacial properties at the atomistic scale, especially for those interested in the design and development of new molecules and new products. Copyright © 2017. Published by Elsevier B.V.

Polycyclic Aromatic Hydrocarbons and Esophageal Squamous Cell Carcinoma-A Review

Science.gov (United States)

Roshandel, Gholamreza; Semnani, Shahryar; Malekzadeh, Reza; Dawsey, Sanford M.

2018-01-01

Esophageal cancer (EC) is the 8th most common cancer and the 6th most frequent cause of cancer mortality worldwide. Esophageal squamous cell carcinoma (ESCC) is the most common type of EC. Exposure to polycyclic aromatic hydrocarbons (PAHs) has been suggested as a risk factor for developing ESCC. In this paper we will review different aspects of the relationship between PAH exposure and ESCC. PAHs are a group of compounds that are formed by incomplete combustion of organic matter. Studies in humans have shown an association between PAH exposure and development of ESCC in many populations. The results of a recent case-control study in a high risk population in northeastern Iran showed a dramatic dose-response relationship between PAH content in non-tumor esophageal tissue (the target tissue for esophageal carcinogenesis) and ESCC case status, consistent with a causal role for PAH exposure in the pathogenesis of ESCC. Identifying the main sources of exposure to PAHs may be the first and most important step in designing appropriate PAH-reduction interventions for controlling ESCC, especially in high risk areas. Coal smoke and drinking mate have been suggested as important modifiable sources of PAH exposure in China and Brazil, respectively. But the primary source of exposure to PAHs in other high risk areas for ESCC, such as northeastern Iran, has not yet been identified. Thus, environmental studies to determining important sources of PAH exposure should be considered as a high priority in future research projects in these areas. PMID:23102250

Management of waste electrical and electronic equipment in Romania: A mini-review.

Science.gov (United States)

Ciocoiu, Carmen Nadia; Colesca, Sofia Elena; Rudăreanu, Costin; Popescu, Maria-Loredana

2016-02-01

Around the world there are growing concerns for waste electrical and electronic equipment. This is motivated by the harmful effects of waste electrical and electronic equipment on the environment, but also by the perspectives of materials recovery. Differences between countries regarding waste electrical and electronic equipment management are notable in the European Union. Romania is among the countries that have made significant efforts to comply with European Union regulations, but failed reaching the collection target. The article presents a mini review of the waste electrical and electronic equipment management system in Romania, based on legislation and policy documents, statistical data, research studies and reports published by national and international organisations. The article debates subjects like legislative framework, the electrical and electronic equipment Romanian market, the waste electrical and electronic equipment collection system, waste electrical and electronic equipment processing and waste electrical and electronic equipment behaviour. The recast of the European directive brings new challenges to national authorities and to other stakeholders involved in the waste electrical and electronic equipment management. Considering the fact that Romania has managed a collection rate of roughly 1 kg capita(-1) in the last years, the new higher collection targets established by the waste electrical and electronic equipment Directive offer a serious challenge for the management system. Therefore, another aim of the article is to highlight the positive and negative aspects in the Romanian waste electrical and electronic equipment field, in order to identify the flows that should be corrected and the opportunities that could help improve this system to the point of meeting the European standards imposed by the European Directive. © The Author(s) 2015.

Impact of implant design on primary stability of orthodontic mini-implants.

Science.gov (United States)

Wilmes, Benedict; Ottenstreuer, Stephanie; Su, Yu-Yu; Drescher, Dieter

2008-01-01

Skeletal anchorage with mini-implants has greatly broadened the treatment possibilities in orthodontics over the last few years. To reduce implant failure rates, it is advisable to obtain adequate primary stability. The aim of this study was to quantitatively analyze the impact of implant design and dimension on primary stability. Forty-two porcine iliac bone segments were prepared and embedded in resin. To evaluate the primary stability, we documented insertion torques of the following mini-implants: Aarhus Screw, AbsoAnchor, LOMAS, Micro-Anchorage-System, ORLUS and Spider Screw. In each bone, five Dual Top Screws were inserted for reference purposes to achieve comparability among the specimens. We observed wide variation in insertion torques and hence primary stability, depending on mini-implant design and dimension; the great impact that mini-implant diameter has on insertion torques was particularly conspicuous. Conical mini-implants achieved higher primary stabilities than cylindrical designs. The diameter and design of the mini-implant thread have a distinctive impact on primary stability. Depending on the region of insertion and local bone quality, the choice of the mini-implant design and size is crucial to establish sufficient primary stability.

Conformational polymorphism and aromaticity in crystalline dibenzotetraaza[14]annulene derivatives

Science.gov (United States)

Śliwiński, Jan; Eilmes, Julita; Oleksyn, Barbara J.; Stadnicka, Katarzyna

2004-06-01

The structures of two single crystal modifications, orange and yellow, of 7,16-dibenzoyl-6,8,15,17-tetramethyl-5,14-dihydrodibenzo [b,i][1,4,8,11]tetraazacyclotetradecine were determined in room and low temperatures. The aromaticity of the 14-membered macrocyclic ring system was studied with the use of HOMA index and compared to the values calculated for the structures found in the Cambridge Structural Database System. The nature of the polymorphism of the investigated molecules was elucidated. The molecules of the orange and yellow modifications differ in the mutual orientation of the benzoyl groups. The molecular conformation in the yellow crystals is stabilized by two intramolecular hydrogen bonds, C-H⋯OC, which do not occur in the orange modification. Weak, but numerous, intermolecular bonds of this type occur in both modifications, but in the orange polymorph a π-π interaction is also observed, while in the yellow modification a C-H⋯N intermolecular bond is formed.

Formation of self-assembled monolayer of curcuminoid molecules on gold surfaces

International Nuclear Information System (INIS)

Berlanga, Isadora; Etcheverry-Berríos, Álvaro; Mella, Andy; Jullian, Domingo; Gómez, Victoria Alejandra; Aliaga-Alcalde, Núria; Fuenzalida, Victor; Flores, Marcos

2017-01-01

Highlights: • Thiophene curcuminoid molecules deposited on a gold surface by immersion. • Molecular dynamic studies of the molecular arrangement approaching the surface. • XPS and STM studies showing different arrangement of the molecules on the surface. • Molecular Interaction with surface depends on the sulfur position in thiophene rings. • Temporal evolution of the molecular arrangement on the surface. - Abstract: We investigated the formation of self-assembled monolayers of two thiophene curcuminoid molecules, 2-thphCCM (1) and 3-thphCCM (2), on polycrystalline gold substrates prepared by immersion of the surfaces in a solution of the molecules during 24 h. The functionalized surfaces were studied by scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). Despite the fact that both molecules have the same composition and almost the same structure, these molecules exhibit different behavior on the gold surface, which can be explained by the different positions of the sulfur atoms in the terminal aromatic rings. In the case of molecule 1, the complete formation of a SAM can be observed after 24 h of immersion. In the case of molecule 2, the transition from flat-lying to upright configuration on the surface is still in process after 24 h of immersion. This is attributed to the fact that molecule 2 have the sulfur atoms more exposed than molecule 1.

Formation of self-assembled monolayer of curcuminoid molecules on gold surfaces

Energy Technology Data Exchange (ETDEWEB)

Berlanga, Isadora [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Blanco Encalada 2008, Santiago (Chile); Etcheverry-Berríos, Álvaro; Mella, Andy; Jullian, Domingo [Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Beaucheff 851, Santiago (Chile); Gómez, Victoria Alejandra [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Blanco Encalada 2008, Santiago (Chile); Aliaga-Alcalde, Núria [ICREA (Institució Catalana de Recerca i Estudis Avançats), Passeig Lluís Companys, 23, 08018, Barcelona (Spain); CSIC-ICMAB (Institut de Ciència dels Materials de Barcelona), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra (Spain); Fuenzalida, Victor [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Blanco Encalada 2008, Santiago (Chile); Flores, Marcos, E-mail: mflorescarra@ing.uchile.cl [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Blanco Encalada 2008, Santiago (Chile); and others

2017-01-15

Highlights: • Thiophene curcuminoid molecules deposited on a gold surface by immersion. • Molecular dynamic studies of the molecular arrangement approaching the surface. • XPS and STM studies showing different arrangement of the molecules on the surface. • Molecular Interaction with surface depends on the sulfur position in thiophene rings. • Temporal evolution of the molecular arrangement on the surface. - Abstract: We investigated the formation of self-assembled monolayers of two thiophene curcuminoid molecules, 2-thphCCM (1) and 3-thphCCM (2), on polycrystalline gold substrates prepared by immersion of the surfaces in a solution of the molecules during 24 h. The functionalized surfaces were studied by scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). Despite the fact that both molecules have the same composition and almost the same structure, these molecules exhibit different behavior on the gold surface, which can be explained by the different positions of the sulfur atoms in the terminal aromatic rings. In the case of molecule 1, the complete formation of a SAM can be observed after 24 h of immersion. In the case of molecule 2, the transition from flat-lying to upright configuration on the surface is still in process after 24 h of immersion. This is attributed to the fact that molecule 2 have the sulfur atoms more exposed than molecule 1.

Effect of Recycling Protocol on Mechanical Strength of Used Mini-Implants

OpenAIRE

Estelita, Sérgio; Janson, Guilherme; Chiqueto, Kelly; Ferreira, Eduardo Silveira

2014-01-01

Purpose. This study evaluated the influence of recycling process on the torsional strength of mini-implants. Materials and Methods. Two hundred mini-implants were divided into 4 groups with 50 screws equally distributed in five diameters (1.3 to 1.7 mm): control group (CG): unused mini-implants, G1: mini-implants inserted in pig iliac bone and removed, G2: same protocol of group 1 followed by sonication for cleaning and autoclave sterilization, and G3: same insertion protocol of group 1 follo...

Mini-mental Parkinson (MMP) as a dementia screening test: comparison with the Mini-Mental State Examination (MMSE).

Science.gov (United States)

Larner, Andrew J

2012-07-01

As populations age, screening instruments for cognitive impairment and dementia will become of increasing importance in clinical practice. Mini-Mental Parkinson (MMP), a derivative of the Mini-Mental State Examination (MMSE), was originally described as a cognitive screening instrument for use in Parkinson's disease. Its item content addresses some of the acknowledged shortcomings of the MMSE. Pragmatic use of MMP in general cognitive clinics has not previously been examined. To compare the performance of two scales, Mini-Mental Parkinson (MMP) and the Mini-Mental State Examination (MMSE), as cognitive screening instruments for dementia in a memory clinic population. MMP was administered prospectively to 201 consecutive new patient referrals independent of other tests used to establish dementia diagnosis according to standard diagnostic criteria (DSM-IV). Diagnostic utility of MMP for dementia was measured and compared with MMSE. MMP proved easy to use and acceptable to patients. Optimal test accuracy (0.86) was at MMP cutoff of ≤ 17/32, with sensitivity 0.51, specificity 0.97, positive predictive value 0.83, negative predictive value 0.87, and area under Receiver Operating Characteristic curve 0.89. Using a higher cutoff (≤ 29/32), MMP sensitivity was 1.00 with specificity 0.70. MMP scores correlated with MMSE (r = 0.93) and diagnostic agreement was high (κ = 0.85). MMP is a useful screening instrument in the memory clinic setting, with patients who fall below the designated cutoff requiring further investigation to ascertain a cause for their cognitive impairment.

Ionization of Polycyclic Aromatic Hydrocarbon Molecules around the Herbig Ae/be ENVIRONMENT*

Science.gov (United States)

Sakon, Itsuki; Onaka, Takashi; Okamoto, Yoshiko K.; Kataza, Hirokazu; Kaneda, Hidehiro; Honda, Mitsuhiko

We present the results of mid-infrared N-band spectroscopy of the Herbig Ae/Be system MWC1080 using the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on board the 8 m Subaru Telescope. The MWC1080 has a geometry such that the diffuse nebulous structures surround the central Herbig B0 type star. We focus on the properties of polycyclic aromatic hydrocarbons (PAHs) and PAH-like species, which are thought to be the carriers of the unidentified infrared (UIR) bands in such environments. A series of UIR bands at 8.6, 11.0, 11.2, and 12.7 μm is detected throughout the system and we find a clear increase in the UIR 11.0 μm/11.2 μm ratio in the vicinity of the central star. Since the UIR 11.0 μm feature is attributed to a solo-CH out-of-plane wagging mode of cationic PAHs while the UIR 11.2 μm feature to a solo-CH out-of-plane bending mode of neutral PAHs, the large 11.0 μm/11.2 μm ratio directly indicates a promotion of the ionization of PAHs near the central star.

Mini-clinical evaluation exercise til evaluering af kommunikation og samarbejde i ambulatoriet

DEFF Research Database (Denmark)

Eriksen, Jesper Grau; Simonsen, Dorit; Bastholt, Lars

2009-01-01

INTRODUCTION: In the revised Danish medical specialist training increased focus has been placed on competences which are hard to evaluate such as communication skills. Mini-CEX seems promising as an evaluation tool. Our aim was to test: 1) whether mini-CEX was useable in the evaluation...... of communicative and cooperative skills and 2) whether mini-CEX would provide reproducible data. MATERIAL AND METHODS: Twenty-one residents were evaluated by mini-CEX by trained observers. Seventeen residents had at least two observations within a short period of time and these data were used to estimate the mini...

Gas Chromatographic-Ion Trap Mass Spectrometric Analysis of Volatile Organic Compounds by Ion-Molecule Reactions Using the Electron-Deficient Reagent Ion CCl{3/+}

Science.gov (United States)

Wang, Cheng-Zhong; Su, Yue; Wang, Hao-Yang; Guo, Yin-Long

2011-10-01

When using tetrachloromethane as the reagent gas in gas chromatography-ion trap mass spectrometry equipped with hybrid ionization source, the cation CCl{3/+} was generated in high abundance and further gas-phase experiments showed that such an electron-deficient reagent ion CCl{3/+} could undergo interesting ion-molecule reactions with various volatile organic compounds, which not only present some informative gas-phase reactions, but also facilitate qualitative analysis of diverse volatile compounds by providing unique mass spectral data that are characteristic of particular chemical structures. The ion-molecule reactions of the reagent ion CCl{3/+} with different types of compounds were studied, and results showed that such reactions could give rise to structurally diagnostic ions, such as [M + CCl3 - HCl]+ for aromatic hydrocarbons, [M - OH]+ for saturated cyclic ether, ketone, and alcoholic compounds, [M - H]+ ion for monoterpenes, M·+ for sesquiterpenes, [M - CH3CO]+ for esters, as well as the further fragment ions. The mechanisms of ion-molecule reactions of aromatic hydrocarbons, aliphatic ketones and alcoholic compounds with the reagent ion CCl{3/+} were investigated and proposed according to the information provided by MS/MS experiments and theoretical calculations. Then, this method was applied to study volatile organic compounds in Dendranthema indicum var. aromaticum and 20 compounds, including monoterpenes and their oxygen-containing derivatives, aromatic hydrocarbon and sesquiterpenes were identified using such ion-molecule reactions. This study offers a perspective and an alternative tool for the analysis and identification of various volatile compounds.

Reactions of aromatic diazonium salts with unsaturated compounds in the presence of nucleophiles

Science.gov (United States)

Grishchuk, B. D.; Gorbovoi, P. M.; Ganushchak, N. I.; Dombrovskii, A. V.

1994-03-01

The review surveys the reactions of aromatic diazonium salts with diene and monounsaturated compounds in the presence of nucleophiles. Certain further reactions of the reaction products and their application are considered. The bibliography includes 63 references.

Therapeutic potential of abalone and status of bioactive molecules: A comprehensive review.

Science.gov (United States)

Suleria, H A R; Masci, P P; Gobe, G C; Osborne, S A

2017-05-24

Marine organisms are increasingly being investigated as sources of bioactive molecules with therapeutic applications as nutraceuticals and pharmaceuticals. In particular, nutraceuticals are gaining popularity worldwide owing to their therapeutic potential and incorporation in functional foods and dietary supplements. Abalone, a marine gastropod, contains a variety of bioactive compounds with anti-oxidant, anti-thrombotic, anti-inflammatory, anti-microbial, and anti-cancer activities. For thousands of years different cultures have used abalone as a traditional functional food believing consumption provides health benefits. Abalone meat is one of the most precious commodities in Asian markets where it is considered a culinary delicacy. Recent research has revealed that abalone is composed of many vital moieties like polysaccharides, proteins, and fatty acids that provide health benefits beyond basic nutrition. A review of past and present research is presented with relevance to the therapeutic potential of bioactive molecules from abalone.

Barriers and facilitators to the implementation of orthodontic mini-implants in clinical practice: a protocol for a systematic review and meta-analysis.

Science.gov (United States)

Meursinge Reynders, Reint; Ronchi, Laura; Ladu, Luisa; Di Girolamo, Nicola; de Lange, Jan; Roberts, Nia; Mickan, Sharon

2016-02-05

Most orthodontic treatment plans need some form of anchorage to control the reciprocal forces of tooth movement. Orthodontic mini implants (OMIs) have been hailed for having revolutionized orthodontics, because they provide anchorage without depending on the collaboration of patients, they have a favorable effectiveness compared with conventional anchorage devices, and they can be used for a wide scale of treatment objectives. However, surveys have shown that many orthodontists never or rarely use them. To understand the rationale behind this knowledge-to-action gap, we will conduct a systematic review that will identify and quantify potential barriers and facilitators to the implementation of OMIs in clinical practice for all potential stakeholders, i.e., patients, family members, clinicians, office staff, clinic owners, policy makers, etc. The prevalence of clinicians that do not use OMIs will be our secondary outcome. The Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) 2015 Statement was adopted as the framework for reporting this manuscript. We will apply broad-spectrum search strategies and will search MEDLINE and more than 40 other databases. We will conduct searches in the gray literature, screen reference lists, and hand-search 12 journals. All study designs, stakeholders, interventions, settings, and languages will be eligible. We will search studies that report on barriers or facilitators to the implementation of orthodontic mini implants (OMIs) in clinical practice. Implementation constructs and their prevalence among pertinent stakeholders will be our primary outcomes. All searching and data extraction procedures will be conducted by three experienced reviewers. We will also contact authors and investigators to obtain additional information on data items and unidentified studies. Risk of bias will be scored with tools designed for the specific study designs. We will assess heterogeneity, meta-biases, and the

Investigating Superhydrogenated Polycyclic Aromatic Hydrocarbons as catalysts for Interstellar H2 formation

DEFF Research Database (Denmark)

Simonsen, Frederik Doktor Skødt

2016-01-01

Temperature programmed desorption has been used to investigate adsorption and abstraction of hydrogen atoms on the polycyclic aromatic hydrocarbon, coronene. The coronene molecules were exposed to different hydrogen fluences at a dosing temperature of 1000K. Large fluences of hydrogen leave...... large abundances, alongside H2[2]. To investigate the the abstraction and adsoption patterns of hydrogen/deuterium on coronene, C24H12 (a PAH), we used temperature programmed desorption (TPD). Coronene monolayers were prepared on graphite and exposed to different fluences of 1000 K H or D atoms...

Mini-conference and Related Sessions on Laboratory Plasma Astrophysics

International Nuclear Information System (INIS)

Hantao Ji

2004-01-01

This paper provides a summary of some major physics issues and future perspectives discussed in the Mini-Conference on Laboratory Plasma Astrophysics. This Mini-conference, sponsored by the Topical Group on Plasma Astrophysics, was held as part of the American Physical Society's Division of Plasma Physics 2003 Annual Meeting (October 27-31, 2003). Also included are brief summaries of selected talks on the same topic presented at two invited paper sessions (including a tutorial) and two contributed focus oral sessions, which were organized in coordination with the Mini-Conference by the same organizers

Mini-conference and Related Sessions on Laboratory Plasma Astrophysics

Energy Technology Data Exchange (ETDEWEB)

Hantao Ji

2004-02-27

This paper provides a summary of some major physics issues and future perspectives discussed in the Mini-Conference on Laboratory Plasma Astrophysics. This Mini-conference, sponsored by the Topical Group on Plasma Astrophysics, was held as part of the American Physical Society's Division of Plasma Physics 2003 Annual Meeting (October 27-31, 2003). Also included are brief summaries of selected talks on the same topic presented at two invited paper sessions (including a tutorial) and two contributed focus oral sessions, which were organized in coordination with the Mini-Conference by the same organizers.

Screening for Dementia in Older Adults: Comparison of Mini-Mental State Examination, Mini-Cog, Clock Drawing Test and AD8.

Science.gov (United States)

Yang, Li; Yan, Jing; Jin, Xiaoqing; Jin, Yu; Yu, Wei; Xu, Shanhu; Wu, Haibin

2016-01-01

This study was conducted to estimate screening performance of dementia screening tools including Mini-Mental State Examination (MMSE), Mini-Cog, Clock Drawing Test (CDT) and Ascertain Dementia 8 questionnaire (AD8) for older adults. 2015 participants aged 65 years or more in eastern China were enrolled. 4 screening tests were administered and scored by specifically trained psychiatrists. We used data from two-by-two tables to calculate the sensitivity, specificity, and positive and negative predictive values (PPV/NPV). Our study showed that dementia was highly prevalent among elderly in Zhejiang province. The Mini-Cog, with excellent screening characteristics and spending less time, could be considered to be used as a screening tool among communities to help to diagnose dementia early.

Pulse shape discrimination in non-aromatic plastics

Energy Technology Data Exchange (ETDEWEB)

Paul Martinez, H.; Pawelczak, Iwona; Glenn, Andrew M.; Leslie Carman, M.; Zaitseva, Natalia; Payne, Stephen

2015-01-21

Recently it has been demonstrated that plastic scintillators have the ability to distinguish neutrons from gamma rays by way of pulse shape discrimination (PSD). This discovery has lead to new materials and new capabilities. Here we report our work with the effects of aromatic, non-aromatic, and mixed aromatic/non-aromatic matrices have on the performance of PSD plastic scintillators.

The importance of nuclear quantum effects in spectral line broadening of optical spectra and electrostatic properties in aromatic chromophores

Science.gov (United States)

Law, Y. K.; Hassanali, A. A.

2018-03-01

In this work, we examine the importance of nuclear quantum effects on capturing the line broadening and vibronic structure of optical spectra. We determine the absorption spectra of three aromatic molecules indole, pyridine, and benzene using time dependent density functional theory with several molecular dynamics sampling protocols: force-field based empirical potentials, ab initio simulations, and finally path-integrals for the inclusion of nuclear quantum effects. We show that the absorption spectrum for all these chromophores are similarly broadened in the presence of nuclear quantum effects regardless of the presence of hydrogen bond donor or acceptor groups. We also show that simulations incorporating nuclear quantum effects are able to reproduce the heterogeneous broadening of the absorption spectra even with empirical force fields. The spectral broadening associated with nuclear quantum effects can be accounted for by the broadened distribution of chromophore size as revealed by a particle in the box model. We also highlight the role that nuclear quantum effects have on the underlying electronic structure of aromatic molecules as probed by various electrostatic properties.

Reversal of Hückel (anti)aromaticity in the lowest triplet states of hexaphyrins and spectroscopic evidence for Baird's rule

Science.gov (United States)

Sung, Young Mo; Yoon, Min-Chul; Lim, Jong Min; Rath, Harapriya; Naoda, Koji; Osuka, Atsuhiro; Kim, Dongho

2015-05-01

The reversal of (anti)aromaticity in a molecule's triplet excited state compared with its closed-shell singlet ground state is known as Baird's rule and has attracted the interest of synthetic, physical organic chemists and theorists because of the potential to modulate the fundamental properties of highly conjugated molecules. Here we show that two closely related bis-rhodium hexaphyrins (R26H and R28H) containing [26] and [28] π-electron peripheries, respectively, exhibit properties consistent with Baird's rule. In the ground state, R26H exhibits a sharp Soret-like band and distinct Q-like bands characteristic of an aromatic porphyrinoid, whereas R28H exhibits a broad absorption spectrum without Q-like bands, which is typical of an antiaromatic porphyrinoid. In contrast, the T-T absorption of R26H is broad, weak and featureless, whereas that of R28H displays an intense and sharp Soret-like band. These spectral signatures, in combination with quantum chemical calculations, are in line with qualitative expectations based on Baird's rule.

Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review

Energy Technology Data Exchange (ETDEWEB)

Haritash, A.K., E-mail: akharitash@gmail.com [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar, Haryana (India); Kaushik, C.P. [Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar, Haryana (India)

2009-09-30

PAHs are aromatic hydrocarbons with two or more fused benzene rings with natural as well as anthropogenic sources. They are widely distributed environmental contaminants that have detrimental biological effects, toxicity, mutagenecity and carcinogenicity. Due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity, the PAHs have gathered significant environmental concern. Although PAH may undergo adsorption, volatilization, photolysis, and chemical degradation, microbial degradation is the major degradation process. PAH degradation depends on the environmental conditions, number and type of the microorganisms, nature and chemical structure of the chemical compound being degraded. They are biodegraded/biotransformed into less complex metabolites, and through mineralization into inorganic minerals, H{sub 2}O, CO{sub 2} (aerobic) or CH{sub 4} (anaerobic) and rate of biodegradation depends on pH, temperature, oxygen, microbial population, degree of acclimation, accessibility of nutrients, chemical structure of the compound, cellular transport properties, and chemical partitioning in growth medium. A number of bacterial species are known to degrade PAHs and most of them are isolated from contaminated soil or sediments. Pseudomonas aeruginosa, Pseudomons fluoresens, Mycobacterium spp., Haemophilus spp., Rhodococcus spp., Paenibacillus spp. are some of the commonly studied PAH-degrading bacteria. Lignolytic fungi too have the property of PAH degradation. Phanerochaete chrysosporium, Bjerkandera adusta, and Pleurotus ostreatus are the common PAH-degrading fungi. Enzymes involved in the degradation of PAHs are oxygenase, dehydrogenase and lignolytic enzymes. Fungal lignolytic enzymes are lignin peroxidase, laccase, and manganese peroxidase. They are extracellular and catalyze radical formation by oxidation to destabilize bonds in a molecule. The biodegradation of PAHs has been observed under both aerobic and anaerobic conditions

Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review

International Nuclear Information System (INIS)

Haritash, A.K.; Kaushik, C.P.

2009-01-01

PAHs are aromatic hydrocarbons with two or more fused benzene rings with natural as well as anthropogenic sources. They are widely distributed environmental contaminants that have detrimental biological effects, toxicity, mutagenecity and carcinogenicity. Due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity, the PAHs have gathered significant environmental concern. Although PAH may undergo adsorption, volatilization, photolysis, and chemical degradation, microbial degradation is the major degradation process. PAH degradation depends on the environmental conditions, number and type of the microorganisms, nature and chemical structure of the chemical compound being degraded. They are biodegraded/biotransformed into less complex metabolites, and through mineralization into inorganic minerals, H 2 O, CO 2 (aerobic) or CH 4 (anaerobic) and rate of biodegradation depends on pH, temperature, oxygen, microbial population, degree of acclimation, accessibility of nutrients, chemical structure of the compound, cellular transport properties, and chemical partitioning in growth medium. A number of bacterial species are known to degrade PAHs and most of them are isolated from contaminated soil or sediments. Pseudomonas aeruginosa, Pseudomons fluoresens, Mycobacterium spp., Haemophilus spp., Rhodococcus spp., Paenibacillus spp. are some of the commonly studied PAH-degrading bacteria. Lignolytic fungi too have the property of PAH degradation. Phanerochaete chrysosporium, Bjerkandera adusta, and Pleurotus ostreatus are the common PAH-degrading fungi. Enzymes involved in the degradation of PAHs are oxygenase, dehydrogenase and lignolytic enzymes. Fungal lignolytic enzymes are lignin peroxidase, laccase, and manganese peroxidase. They are extracellular and catalyze radical formation by oxidation to destabilize bonds in a molecule. The biodegradation of PAHs has been observed under both aerobic and anaerobic conditions and the rate can

Evidence for a strong sulfur-aromatic interaction derived from crystallographic data.

Science.gov (United States)

Zauhar, R J; Colbert, C L; Morgan, R S; Welsh, W J

2000-03-01

Letters, 1985, Vol. 190, pp. 209-213), as well as studies involving molecular mechanics (G. Nemethy and H. A. Scheraga, Biochemistry and Biophysics Research Communications, 1981, Vol. 98, pp. 482-487) and quantum chemical calculations (B. V. Cheney, M. W. Schulz, and J. Cheney, Biochimica Biophysica Acta, 1989, Vol. 996, pp.116-124; J. Pranata, Bioorganic Chemistry, 1997, Vol. 25, pp. 213-219)-all of which point to the possible importance of the sulfur-aromatic interaction. However, the preferred geometry of the interaction, as determined from our analysis of the small-molecule crystal data, differs significantly from that found by other approaches. Copyright 2000 John Wiley & Sons, Inc.

Systemic levels of metallic ions released from orthodontic mini-implants.

Science.gov (United States)

de Morais, Liliane Siqueira; Serra, Glaucio Guimarães; Albuquerque Palermo, Elisabete Fernandes; Andrade, Leonardo Rodrigues; Müller, Carlos Alberto; Meyers, Marc André; Elias, Carlos Nelson

2009-04-01

Orthodontic mini-implants are a potential source of metallic ions to the human body because of the corrosion of titanium (Ti) alloy in body fluids. The purpose of this study was to gauge the concentration of Ti, aluminum (Al), and vanadium (V), as a function of time, in the kidneys, livers, and lungs of rabbits that had Ti-6Al-4V alloy orthodontic mini-implants placed in their tibia. Twenty-three New Zealand rabbits were randomly divided into 4 groups: control, 1 week, 4 weeks, and 12 weeks. Four orthodontic mini-implants were placed in the left proximal tibia of 18 rabbits. Five control rabbits had no orthodontic mini-implants. After 1, 4, and 12 weeks, the rabbits were killed, and the selected tissues were extracted and prepared for analysis by graphite furnace atomic absorption spectrophotometry. Low amounts of Ti, Al, and V were detectable in the 1-week, 4-weeks, and 12-weeks groups, confirming that release of these metals from the mini-implants occurs, with diffusion and accumulation in remote organs. Despite the tendency of ion release when using the Ti alloy as orthodontic mini-implants, the amounts of metals detected were significantly below the average intake of these elements through food and drink and did not reach toxic concentrations.

Mini Max (T-864): a progress report on a disoriented chiral condensate search at the Tevatron

International Nuclear Information System (INIS)

Taylor, Cyrus

1996-01-01

Relativistic quantum field theory treats the vacuum as a medium with bulk properties characterized by long-range order parameters. This has led to suggestions that regions disoriented vacuum might be formed in high energy collision processes. The putative phenomenology of such 'Disoriented Chiral condensates'will be reviewed and used to motivate the design of Fermilab experiment T-864 (Mini Max). The status f the experiment at the time of writing is reviewed, as are prospects for future developments. (author)

Measuring mental health in the clinical setting: what is important to service users? The Mini-Service user Recovery Evaluation scale (Mini-SeRvE).

Science.gov (United States)

Barber, Joanna M; Parsons, Helen; Wilson, Carol A; Cook, Christopher C H

2017-12-01

Since 2001, a policy of positive mental health recovery has been promoted in the UK, with service user involvement. This has not been easy to implement in the clinical setting. To develop and validate a brief self-report, service user-designed, outcome measure (Mini-SeRvE), for clinical use, including spiritual and religious issues. From the previously developed Service user Recovery Evaluation scale (SeRvE), 15 questions were selected for Mini-SeRvE which was self-completed by 207 people; 100 service users and, for comparison, 107 staff. Results were analysed using SPSS software (SPSS Inc., Chicago, IL). Mini-SeRvE is reliable, Cronbach's alpha 0.852. Correlation with another recovery scale, Mental Health Recovery Measure, was high, r = 0.819. Three reliable subscales emerged; existential well-being (EWB), mental ill-being (MIB) and religious well-being (RWB). Scores of the EWB and MIB subscales were higher for staff, consistent with higher mental well-being. Religious well-being scores were higher in service users, who also rated religion as more important to them. Mini-SeRvE is a valid measure of service user recovery. The importance of religion/spiritual belief for our users is highlighted, this being reflected in the subject matter of Mini-SeRvE. Mini-SeRvE assessments could show individual priorities, evaluate therapy and aid clinical decision-making.

Probing the spin multiplicity of gas-phase polycyclic aromatic hydrocarbons through their infrared emission spectrum: a theoretical study.

Science.gov (United States)

Falvo, Cyril; Calvo, Florent; Parneix, Pascal

2012-08-14

The anharmonic infrared emission spectrum following an optical excitation has been calculated for a variety of polycyclic aromatic hydrocarbon molecules in their ground singlet electronic state or in their triplet state. The computational protocol relies on second-order perturbation theory and involves a quartic vibrational Hamiltonian, the vibrational quantum numbers being sampled according to a Monte Carlo procedure. In the case of neutral naphthalene, the IR spectrum obtained in the (ground) singlet state differs significantly from the spectrum in the triplet state, especially for out-of-plane CH bending modes. Although not as prominent, spectral differences in larger molecules are still observable.

New type of bonding formed from an overlap between pi aromatic and pi C=O molecular orbitals stabilizes the coexistence in one molecule of the ionic and neutral meso-ionic forms of imidazopyridine.

Science.gov (United States)

Hoffmann, Marcin; Plutecka, Agnieszka; Rychlewska, Urszula; Kucybala, Zdzislaw; Paczkowski, Jerzy; Pyszka, Ilona

2005-05-26

New bis(imidazo)pyridine dye has been synthesized and tested as a potential photoinitaitor for free-radical polymerization induced with the visible emission of an argon ion laser. The X-ray analysis based on data collected at 170 and 130 K, as well as density functional theory (DFT) calculations, revealed the presence of two different forms of imidazopyridine rings within the same molecule. These two forms of the same moiety had not only different geometries but different electronic structures as well. One of the imidazopyridine rings was in the ionic form, while the other was in the meso-ionic form. DFT calculations provided an explanation for such an observed phenomena. The averaging of ionic and meso-ionic forms of imidazopyridine rings within the same molecule is hindered because of an attractive interaction between them. Analysis of electronic density revealed that, indeed, a new type of bonding is formed as the result of an overlap between pi aromatic and pi C=O molecular orbitals. This bonding, like the hydrogen bond, is primarily of electrostatic character, and its energy was estimated at 3.5 kcal/mol.

Plasmodium Falciparum: Adhesion Phenotype of Infected Erythrocytes Using Classical and Mini-Column Cytoadherence Techniques

Directory of Open Access Journals (Sweden)

N Kalantari

2013-03-01

Full Text Available Background: Cytoadherence of Plasmodium falciparum- infected erythrocytes to host cells is an impor­tant trait for parasite survival and has a major role in pathology of malaria disease. Infections with P. falciparum usually consist of several subpopulations of parasites with different adhesive proper­ties. This study aimed to compare relative sizes of various binding subpopulations of different P. falciparum isolates. It also investigated the adhesive phenotype of a laboratory P. falciparum line, A4, using different binding techniques.Methods: Seven different P. falciparum isolates (ITG, A4, 3D7 and four field isolates were cultivated to late trophozoite and schizont and then cytoadherence to cell differentiation 36 (CD36, intercellu­lar cell adhesion molecule-1 (ICAM-1, and vascular cell adhesion molecule (V-CAM and E-selectin were examined. The relative binding sizes of parasite subpopulations to human receptors were meas­ured by mini-column cytoadherence method. The adhesion phenotype of P. falciparum-A4 line was evaluated by in vitro static, flow-based and mini-column binding assays.Results: The relative binding size of ITG, A4 and 3D7 clones to a column made with CHO/ICAM-1 was 68%, 54% and 0%, respectively. The relative binding sizes of these lines to CHO/CD36 were 59.7%, 28.7% and 0%, respectively. Different field isolates had variable sizes of respective CD36 and ICAM1-binding subpopulations. A4 line had five different subpopulations each with different binding sizes.Conclusion: This study provided further evidence that P. falciparum isolates have different binding subpopulations sizes in an infection. Furthermore, measurement of ICAM-1 or CD36 binding subpopula­tions may practical to study the cytoadherence phenotypes of P. falciparum field isolates at the molecular level.

Mini Heme-Proteins: Designability of Structure and Diversity of Functions.

Science.gov (United States)

Rai, Jagdish

2017-08-30

Natural heme proteins may have heme bound to poly-peptide chain as a cofactor via noncovalent forces or heme as a prosthetic group may be covalently bound to the proteins. Nature has used porphyrins in diverse functions like electron transfer, oxidation, reduction, ligand binding, photosynthesis, signaling, etc. by modulating its properties through diverse protein matrices. Synthetic chemists have tried to utilize these molecules in equally diverse industrial and medical applications due to their versatile electro-chemical and optical properties. The heme iron has catalytic activity which can be modulated and enhanced for specific applications by protein matrix around it. Heme proteins can be designed into novel enzymes for sterio specific catalysis ranging from oxidation to reduction. These designed heme-proteins can have applications in industrial catalysis and biosensing. A peptide folds around heme easily due to hydrophobic effect of the large aromatic ring of heme. The directional property of co-ordinate bonding between peptide and metal ion in heme further specifies the structure. Therefore heme proteins can be easily designed for targeted structure and catalytic activity. The central aromatic chemical entity in heme viz. porphyrin is a very ancient molecule. Its presence in the prebiotic soup and in all forms of life suggests that it has played a vital role in the origin and progressive evolution of living organisms. Porphyrin macrocycles are highly conjugated systems composed of four modified pyrrole subunits interconnected at their α -carbon atoms via methine (=CH-) bridges. Initial minimalist models of hemoproteins focused on effect of heme-ligand co-ordinate bonding on chemical reactivity, spectroscopy, electrochemistry and magnetic properties of heme. The great sensitivity of these spectroscopic features of heme to its surrounding makes them extremely useful in structural elucidation of designed heme-peptide complexes. Therefore heme proteins are

Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

Science.gov (United States)

Lau, E. V.; Gan, S.; Ng, H. K.

2010-01-01

This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs) in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction. PMID:20396670

Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

Directory of Open Access Journals (Sweden)

E. V. Lau

2010-01-01

Full Text Available This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction.

A mini-microscope for in situ monitoring of cells.

Science.gov (United States)

Kim, Sang Bok; Koo, Kyo-in; Bae, Hojae; Dokmeci, Mehmet R; Hamilton, Geraldine A; Bahinski, Anthony; Kim, Sun Min; Ingber, Donald E; Khademhosseini, Ali

2012-10-21

A mini-microscope was developed for in situ monitoring of cells by modifying off-the-shelf components of a commercial webcam. The mini-microscope consists of a CMOS imaging module, a small plastic lens and a white LED illumination source. The CMOS imaging module was connected to a laptop computer through a USB port for image acquisition and analysis. Due to its compact size, 8 × 10 × 9 cm, the present microscope is portable and can easily fit inside a conventional incubator, and enables real-time monitoring of cellular behaviour. Moreover, the mini-microscope can be used for imaging cells in conventional cell culture flasks, such as Petri dishes and multi-well plates. To demonstrate the operation of the mini-microscope, we monitored the cellular migration of mouse 3T3 fibroblasts in a scratch assay in medium containing three different concentrations of fetal bovine serum (5, 10, and 20%) and demonstrated differential responses depending on serum levels. In addition, we seeded embryonic stem cells inside poly(ethylene glycol) microwells and monitored the formation of stem cell aggregates in real time using the mini-microscope. Furthermore, we also combined a lab-on-a-chip microfluidic device for microdroplet generation and analysis with the mini-microscope and observed the formation of droplets under different flow conditions. Given its cost effectiveness, robust imaging and portability, the presented platform may be useful for a range of applications for real-time cellular imaging using lab-on-a-chip devices at low cost.

Mini-implantes ortodônticos como auxiliares da fase de retração anterior Orthodontic mini-implants assisting the anterior retraction phase

Directory of Open Access Journals (Sweden)

Carlo Marassi

2008-10-01

Full Text Available INTRODUÇÃO: os mini-implantes ortodônticos se estabeleceram como um importante método de ancoragem e vêm auxiliando os ortodontistas nas várias etapas do tratamento ortodôntico, eliminando, em grande parte, a necessidade de colaboração dos pacientes e tornando os resultados mais previsíveis. OBJETIVO: este artigo descreve os principais aspectos do uso dos mini-implantes como auxiliares da fase de retração anterior, trazendo considerações sobre suas indicações, quantidade de movimentação dos dentes anteriores, os vetores de força de retração, o controle vertical, o posicionamento dos mini-implantes, os tipos de apoio na região anterior e a força a ser utilizada. São citados os sítios de instalação mais usados para a retração anterior e abordados fatores que deverão ser controlados durante o fechamento de espaço. Por fim, são citadas algumas considerações clínicas sobre o uso dos mini-implantes nessa importante fase do tratamento ortodôntico.INTRODUCTION: The use of orthodontic mini-implants has settled as an important anchorage method and is aiding the orthodontists in the several stages of the treatment, largely eliminating the need of patients' compliance, and turning the results more predictable. AIM: This article describes the main aspects of the use of mini-implants as auxiliaries on the retraction phase of the anterior teeth, bringing considerations about their indications, amount of movement of the anterior teeth, the vectors of retraction force, the vertical control and evaluation of the incisors vestibulolingual tipping, the positioning of the mini-implants, the support types in the anterior area and the force to be applied. The placement sites best used for the anterior retraction are mentioned, and the factors that should be controlled during the space closure are approached. Lastly, some clinical considerations on the use of mini-implants in such important phase of the orthodontic treatment are

Effects of solution P H on the adsorption of aromatic compounds from aqueous solutions by activated carbon

International Nuclear Information System (INIS)

Nouri, S.; Haghseresht, F.; Lu, M.

2002-01-01

Absorption of p-Cresol, Benzoic acid and Nitro Benzene by activated carbon from dilute aqueous solutions was carried out under controlled ph conditions at 310 k. In acidic conditions, well below the pK a of all solutes, it was observed that the adsorbate solubility and the electron density of its aromatic ring were the influencing factors on the extent of the adsorption by affecting the extent of London dispersion forces. In higher solution ph conditions, on the other hand, it was found that the electrostatic forces played a significant role on the extent of adsorption. The Effect of ph must be considered from its combined effects on the carbon surface and on the solute molecules. It was found that the uptake of the molecular forms of the aromatic solutes was dependent on the substituents of the aromatic ring. Adsorption of the solutes in higher P H values was found to be dependent on the concentration of anionic form of the solutes. All isotherms were fitted into Freundlich Isotherm Equations

The Mini-Cog versus the Mini-Mental State Examination and the Clock Drawing Test in daily clinical practice: screening value in a German Memory Clinic.

Science.gov (United States)

Milian, Monika; Leiherr, Anna-Maria; Straten, Guido; Müller, Stephan; Leyhe, Thomas; Eschweiler, Gerhard W

2012-05-01

The aim of this study was to compare the screening value of the Mini-Cog, Clock Drawing Test (CDT), Mini-Mental State Examination (MMSE) and the algorithm MMSE and/or CDT to separate elderly people with dementia from healthy depending on test time, type and severity of dementia, and demographic variables in a German Memory Clinic. Data from a heterogeneous patient sample and healthy participants (n = 502) were retrospectively analyzed. Of the 438 patients with dementia, 49.1% of the dementia diagnoses were Alzheimer's dementia and 50.9% were non-Alzheimer's dementia. Sixty-four participants were classified as cognitively unimpaired. The CDT and an extraction of the 3-item recall of the MMSE were used to constitute the Mini-Cog algorithm. Overall, the Mini-Cog showed significantly higher discriminatory power (86.8%) than the MMSE (72.6% at a cut-off ≤ 24 and 79.2% at ≤ 25, respectively) and CDT (78.1%) (each p 0.05). The specificity of the Mini-Cog (100.0%) was similar to that of the MMSE (100.0% for both cut-offs) and CDT (96.9%) (p = 0.154). For all age and educational groups the Mini-Cog outmatched the CDT and MMSE, and was less affected by education than MMSE and less susceptible for the dementia stage than the CDT. The Mini-Cog proved to have superior discriminatory power than either CDT or MMSE and is demonstrated to be a valid "short" screening instrument taking 3 to 4 minutes to administer in the geriatric setting.

Aromatic-Aromatic Interactions in Biological System: Structure Activity Relationships

International Nuclear Information System (INIS)

Rajagopal, Appavu; Deepa, Mohan; Govindaraju, Munisamy

2016-01-01

While, intramolecular hydrogen bonds have attracted the greatest attention in studies of peptide conformations, the recognition that several other weakly polar interactions may be important determinants of folded structure has been growing. Burley and Petsko provided a comprehensive overview of the importance of weakly polar interactions, in shaping protein structures. The interactions between aromatic rings, which are spatially approximate, have attracted special attention. A survey of the proximal aromatic residue pairs in proteins, allowed Burley and Petsko to suggest that, “phenyl ring centroids are separated by a preferential distance of between 4.5 and 7 Å, and dihedral angles approximately 90° are most common”

Aromatic-Aromatic Interactions in Biological System: Structure Activity Relationships

Energy Technology Data Exchange (ETDEWEB)

Rajagopal, Appavu; Deepa, Mohan [Molecular Biophysics Unit, Indian Institute of Sciences-Bangalore, Karnataka (India); Govindaraju, Munisamy [Bio-Spatial Technology Research Unit, Department of Environmental Biotechnology, School of Environmental Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu (India)

2016-02-26

While, intramolecular hydrogen bonds have attracted the greatest attention in studies of peptide conformations, the recognition that several other weakly polar interactions may be important determinants of folded structure has been growing. Burley and Petsko provided a comprehensive overview of the importance of weakly polar interactions, in shaping protein structures. The interactions between aromatic rings, which are spatially approximate, have attracted special attention. A survey of the proximal aromatic residue pairs in proteins, allowed Burley and Petsko to suggest that, “phenyl ring centroids are separated by a preferential distance of between 4.5 and 7 Å, and dihedral angles approximately 90° are most common”.

Single helically folded aromatic oligoamides that mimic the charge surface of double-stranded B-DNA

Science.gov (United States)

Ziach, Krzysztof; Chollet, Céline; Parissi, Vincent; Prabhakaran, Panchami; Marchivie, Mathieu; Corvaglia, Valentina; Bose, Partha Pratim; Laxmi-Reddy, Katta; Godde, Frédéric; Schmitter, Jean-Marie; Chaignepain, Stéphane; Pourquier, Philippe; Huc, Ivan

2018-05-01

Numerous essential biomolecular processes require the recognition of DNA surface features by proteins. Molecules mimicking these features could potentially act as decoys and interfere with pharmacologically or therapeutically relevant protein-DNA interactions. Although naturally occurring DNA-mimicking proteins have been described, synthetic tunable molecules that mimic the charge surface of double-stranded DNA are not known. Here, we report the design, synthesis and structural characterization of aromatic oligoamides that fold into single helical conformations and display a double helical array of negatively charged residues in positions that match the phosphate moieties in B-DNA. These molecules were able to inhibit several enzymes possessing non-sequence-selective DNA-binding properties, including topoisomerase 1 and HIV-1 integrase, presumably through specific foldamer-protein interactions, whereas sequence-selective enzymes were not inhibited. Such modular and synthetically accessible DNA mimics provide a versatile platform to design novel inhibitors of protein-DNA interactions.

Characterization of surface topography and chemical composition of mini-implants

OpenAIRE

Knop, Luegya Amorim Henriques; Soares, Ana Prates; Shintcovsk, Ricardo Lima; Martins, Lidia Parsekian; Gandini Jr., Luiz Gonzaga

2015-01-01

Abstract Aim : To assess the surface topography and chemical composition of three brands of as-received mini-implants (SIN(r), Morelli(r), and Conexao(r)). Methods: Twelve mini-implants of each brand were analyzed by scanning electron microscopy and energy dispersive X-ray (EDX). Results: There was no significant differences among SIN(r), Morelli(r), and Conexao(r) mini-implants comparing their surface topography by visualization of SEM micrographs and analysis of scores. The EDX analysis ...

Myosin heavy chain isoform expression in adult and juvenile mini-muscle mice bred for high-voluntary wheel running.

Science.gov (United States)

Talmadge, Robert J; Acosta, Wendy; Garland, Theodore

2014-11-01

The myosin heavy chain (MyHC) isoform composition of locomotor and non-locomotor muscles of mini-muscle mice were assessed at the protein and mRNA levels in both adult and juvenile (21 day old) mice. Mini-muscle mice are one outcome of a replicated artificial selection experiment in which four lines of mice were bred for high voluntary wheel running (HR lines). Two of the lines responded with an increase in frequency of a single nucleotide polymorphism in an intron in the MyHC-2b gene (myh4) that when homozygous causes a dramatic reduction in triceps surae mass. We found that both locomotor and non-locomotor muscles of adult mini-muscle mice displayed robust reductions, but not elimination, of the MyHC-2b isoform at both the protein and mRNA levels, with commensurate increases in MyHC-2x and sometimes MyHC-2a, as compared with either a line of HR mice that does not display the mini-muscle phenotype or inbred C57Bl6 mice. Immunohistochemical analyses revealed that locomotor muscles of mini-muscle mice contain fibers that express the MyHC-2b isoform, which migrates normally in SDS-PAGE gels. However, these MyHC-2b positive fibers are generally smaller than the surrounding fibers and smaller than the MyHC-2b positive fibers of non-mini-muscle mice, resulting in characteristically fast muscles that lack a substantial MyHC-2b positive (superficial) region. In contrast, the masseter, a non-locomotor muscle of mini-muscle mice contained MyHC-2b positive fibers that stained more lightly for MyHC-2b, but appeared normal in size and distribution. In adults, many of the MyHC-2b positive fibers in the mini-muscle mice also display central nuclei. Only a small proportion of small MyHC-2b fibers in mini-muscle mice stained positive for the neural cell adhesion molecule, suggesting that anatomical innervation was not compromised. In addition, weanling (21 day old), but not 5 day old mice, displayed alterations in MyHC isoform content at both the protein and mRNA levels, including

A mini review on aflatoxin exposure in Malaysia: past, present and future.

Science.gov (United States)

Mohd-Redzwan, Sabran; Jamaluddin, Rosita; Abd-Mutalib, Mohd Sokhini; Ahmad, Zuraini

2013-11-13

This mini review article described the exposure of aflatoxin in Malaysia, including its presence in the foodstuffs and the detection of aflatoxin biomarkers in human biological samples. Historically, the exposure of aflatoxin in Malaysia can be dated in 1960s where an outbreak of disease in pig farms caused severe liver damage to the animals. Later, an aflatoxicosis case in Perak in 1988 was reported and caused death to 13 children, as up to 3 mg of aflatoxin was present in a single serving of contaminated noodles. Since then, extensive research on aflatoxin has been conducted in Malaysia. The food commodities such as peanuts, cereals, spices, and their products are the main commodities commonly found to be contaminated with aflatoxin. Surprisingly, some of the contaminated foods had levels greater than the permissible limit adopted by the Malaysian Food Regulation 1985. Besides, exposure assessment through the measurement of aflatoxin biomarkers in human biological samples is still in its infancy stage. Nevertheless, some studies had reported the presence of these biomarkers. In fact, it is postulated that Malaysians are moderately exposed to aflatoxin compared to those high risk populations, where aflatoxin contamination in the diets is prevalent. Since the ingestion of aflatoxin could be the integral to the development of liver cancer, the incidence of cancer attributable by dietary aflatoxin exposure in Malaysia has also been reported and published in the literatures. Regardless of these findings, the more important task is to monitor and control humans from being exposed to aflatoxin. The enforcement of law is insufficient to minimize human exposure to aflatoxin. Preventive strategies include agricultural, dietary, and clinical measures should be implemented. With the current research on aflatoxin in Malaysia, a global networking for research collaboration is needed to expand the knowledge and disseminate the information to the global scientific community.

A mini review on aflatoxin exposure in Malaysia: past, present and future

Directory of Open Access Journals (Sweden)

Mohd Redzwan eSabran

2013-11-01

Full Text Available This mini review article described the exposure of aflatoxin in Malaysia, including its presence in the foodstuffs and the detection of aflatoxin biomarkers in human biological samples. Historically, the exposure of aflatoxin in Malaysia can be dated in 1960s where an outbreak of disease in pig farms caused severe liver damage to the animals. Later, an aflatoxicosis case in Perak in 1988 was reported and caused death to 13 children, as up to 3 mg of aflatoxin was present in a single serving of contaminated noodles. Since then, extensive research on aflatoxin has been conducted in Malaysia. The food commodities such as peanuts, cereals, spices and their products are the main commodities commonly found to be contaminated with aflatoxin. Surprisingly, some of the contaminated foods had levels greater than the permissible limit adopted by the Malaysian Food Regulation 1985. Besides, exposure assessment through the measurement of aflatoxin biomarkers in human biological samples is still in its infancy stage. Nevertheless, some studies had reported the presence of these biomarkers. In fact, it is postulated that Malaysians are moderately exposed to aflatoxin compared to those high risk populations, where aflatoxin contamination in the diets is prevalent. Since the ingestion of aflatoxin could be the integral to the development of liver cancer, the incidence of cancer attributable by dietary aflatoxin exposure in Malaysia has also been reported and published in the literatures. Regardless of these findings, the more important task is to monitor and control humans from being exposed to aflatoxin. The enforcement of law is insufficient to minimize human exposure to aflatoxin. Preventive strategies include agricultural, dietary and clinical measures should be implemented. With the current research on aflatoxin in Malaysia, a global networking for research collaboration is needed to expand the knowledge and disseminate the information to the global

A mini review on aflatoxin exposure in Malaysia: past, present and future

Science.gov (United States)

Mohd-Redzwan, Sabran; Jamaluddin, Rosita; Abd.-Mutalib, Mohd Sokhini; Ahmad, Zuraini

2013-01-01

This mini review article described the exposure of aflatoxin in Malaysia, including its presence in the foodstuffs and the detection of aflatoxin biomarkers in human biological samples. Historically, the exposure of aflatoxin in Malaysia can be dated in 1960s where an outbreak of disease in pig farms caused severe liver damage to the animals. Later, an aflatoxicosis case in Perak in 1988 was reported and caused death to 13 children, as up to 3 mg of aflatoxin was present in a single serving of contaminated noodles. Since then, extensive research on aflatoxin has been conducted in Malaysia. The food commodities such as peanuts, cereals, spices, and their products are the main commodities commonly found to be contaminated with aflatoxin. Surprisingly, some of the contaminated foods had levels greater than the permissible limit adopted by the Malaysian Food Regulation 1985. Besides, exposure assessment through the measurement of aflatoxin biomarkers in human biological samples is still in its infancy stage. Nevertheless, some studies had reported the presence of these biomarkers. In fact, it is postulated that Malaysians are moderately exposed to aflatoxin compared to those high risk populations, where aflatoxin contamination in the diets is prevalent. Since the ingestion of aflatoxin could be the integral to the development of liver cancer, the incidence of cancer attributable by dietary aflatoxin exposure in Malaysia has also been reported and published in the literatures. Regardless of these findings, the more important task is to monitor and control humans from being exposed to aflatoxin. The enforcement of law is insufficient to minimize human exposure to aflatoxin. Preventive strategies include agricultural, dietary, and clinical measures should be implemented. With the current research on aflatoxin in Malaysia, a global networking for research collaboration is needed to expand the knowledge and disseminate the information to the global scientific community

The Pollutant Organotins Leads to Respiratory Disease by Inflammation: A Mini-Review

Science.gov (United States)

Nunes-Silva, Albená; Dittz, Dalton; Santana, Higor Scardini; Faria, Rodrigo Alves; Freitas, Katia Michelle; Coutinho, Christiane Rabelo; de Melo Rodrigues, Livia Carla; Miranda-Alves, Leandro; Silva, Ian Victor; Graceli, Jones Bernardes; Freitas Lima, Leandro Ceotto

2018-01-01

Organotins (OTs) are organometallic pollutants. The OTs are organometallic pollutants that are used in many industrial, agricultural, and domestic products, and it works as powerful biocidal compound against large types of microorganisms such as fungi and bacteria. In addition, OTs are well known to be endocrine-disrupting chemicals, leading abnormalities an “imposex” phenomenon in the female mollusks. There are some studies showing that OTs’ exposure is responsible for neural, endocrine, and reproductive dysfunctions in vitro and in vivo models. However, OTs’ effects over the mammalian immune system are poorly understood, particularly in respiratory diseases. The immune system, as well as their cellular components, performs a pivotal role in the control of the several physiologic functions, and in the maintenance and recovery of homeostasis. Thus, it is becoming important to better understand the association between environmental contaminants, as OTs, and the physiological function of immune system. There are no many scientific works studying the relationship between OTs and respiratory disease, especially about immune system activation. Herein, we reported studies in animal, humans, and in vitro models. We searched studies in PUBMED, LILACS, and Scielo platforms. Studies have reported that OTs exposure was able to suppress T helper 1 (Th1) and exacerbate T helper 2 (Th2) response in the immune system. In addition, OTs’ contact could elevate in the airway inflammatory response, throughout a mechanism associated with the apoptosis of T-regulatory cells and increased oxidative stress response. In addition, OTs induce macrophage recruitment to the tissue, leading to the increased necrosis, which stimulates an inflammatory cytokines secretion exacerbating the local inflammation and tissue function loss. Thus, the main intention of this mini-review is to up to date the main findings involving the inflammatory profile (especially Th1 and Th2 response) in the

TOPICAL REVIEW: TeV mini black hole decay at future colliders

Science.gov (United States)

Casanova, Alex; Spallucci, Euro

2006-02-01

It is generally believed that mini black holes decay by emitting elementary particles with a black body energy spectrum. The original calculation leads to the conclusion that about the 90% of the black hole mass is radiated away in the form of photons, neutrinos and light leptons, mainly electrons and muons. With the advent of string theory, such a scenario must be updated by including new effects coming from the stringy nature of particles and interactions. The main modifications with respect to the original picture of black hole evaporation come from recent developments in non-perturbative string theory globally referred to as TeV-scale gravity. By taking for granted that black holes can be produced in hadronic collisions, then their decay must take into account that: (i) we live in a D3 brane embedded into a higher dimensional bulk spacetime; (ii) fundamental interactions, including gravity, are unified at the TeV energy scale. Thus, the formal description of the Hawking radiation mechanism has to be extended to the case of more than four spacetime dimensions and includes the presence of D-branes. This kind of topological defect in the bulk spacetime fabric acts as a sort of 'cosmic fly-paper' trapping electro-weak standard model elementary particles in our (3 + 1)-dimensional universe. Furthermore, unification of fundamental interactions at an energy scale many orders of magnitude lower than the Planck energy implies that any kind of fundamental particle, not only leptons, is expected to be emitted. A detailed understanding of the new scenario is instrumental for optimal tuning of detectors at future colliders, where, hopefully, this exciting new physics will be tested. In this review, we study higher dimensional black hole decay, considering not only the emission of particles according to the Hawking mechanism, but also their near-horizon QED/QCD interactions. The ultimate motivation is to build up a phenomenologically reliable scenario, allowing a clear

Late time CMB anisotropies constrain mini-charged particles

Energy Technology Data Exchange (ETDEWEB)

Burrage, C.; Redondo, J.; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Jaeckel, J. [Univ. of Durham, Inst. for Particle Physics Phenomenology (United Kingdom)

2009-09-15

Observations of the temperature anisotropies induced as light from the CMB passes through large scale structures in the late universe are a sensitive probe of the interactions of photons in such environments. In extensions of the Standard Model which give rise to mini-charged particles, photons propagating through transverse magnetic fields can be lost to pair production of such particles. Such a decrement in the photon flux would occur as photons from the CMB traverse the magnetic fields of galaxy clusters. Therefore late time CMB anisotropies can be used to constrain the properties of mini- charged particles. We outline how this test is constructed, and present new constraints on mini-charged particles from observations of the Sunyaev-Zel'dovich effect in the Coma cluster. (orig.)

Flash pyrolysis of adsorbed aromatic organic acids on carbonate minerals: Assessing the impact of mineralogy for the identification of organic compounds in extraterrestrial bodies

Science.gov (United States)

Zafar, R.

2017-12-01

The relationship between minerals and organics is an essential factor in comprehending the origin of life on extraterrestrial bodies. So far organic molecules have been detected on meteorites, comets, interstellar medium and interplanetary dust particles. While on Mars, organic molecules may also be present as indicated by the Sample Analysis at Mars (SAM) instrument suite on the Curiosity Rover in Martian sediments. Minerals including hydrated phyllosilicate, carbonate, and sulfate minerals have been confirmed in carbonaceous chondrites. The presence of phyllosilicate minerals on Mars has been indicated by in situ elemental analysis by the Viking Landers, remote sensing infrared observations and the presence of smectites in meteorites. Likewise, the presence of carbonate minerals on the surface of Mars has been indicated by both Phoenix Lander and Spirit Rover. Considering the fact that both mineral and organic matter are present on the surface of extraterrestrial bodies including Mars, a comprehensive work is required to understand the interaction of minerals with specific organic compounds. The adsorption of the organic molecule at water/mineral surface is a key process of concentrating organic molecules on the surface of minerals. Carboxylic acids are abundantly observed in extraterrestrial material such as meteorites and interstellar space. It is highly suspected that carboxylic acids are also present on Mars due to the average organic carbon infall rate of 108 kg/yr. Further aromatic organic acids have also been observed in carbonaceous chondrite meteorites. This work presents the adsorption of an aromatic carboxylic acid at the water/calcite interface and characterization of the products formed after adsorption via on-line pyrolysis. Adsorption and online pyrolysis results are used to gain insight into adsorbed aromatic organic acid-calcite interaction. Adsorption and online pyrolysis results are related to the interpretation of organic compounds identified

Estimation of diagnostic performance of dementia screening tests: Mini-Mental State Examination, Mini-Cog, Clock Drawing test and Ascertain Dementia 8 questionnaire.

Science.gov (United States)

Yang, Li; Yan, Jing; Jin, Xiaoqing; Jin, Yu; Yu, Wei; Xu, Shanhu; Wu, Haibin; Xu, Ying; Liu, Caixia

2017-05-09

Dementia is one of the leading causes of dependence in the elderly. This study was conducted to estimate diagnostic performance of dementia screening tests including Mini-Mental State Examination (MMSE), Mini-Cog, Clock Drawing Test (CDT) and Ascertain Dementia 8 questionnaire (AD8) by Bayesian models. A total of 2015 participants aged 65 years or more in eastern China were enrolled. The four screening tests were administered and scored by specifically trained psychiatrists. The prior information of sensitivity and specificity of every screening test was updated via Bayes' theorem to a posterior distribution. Then the results were compared with the estimation based on National Institute of Aging-Alzheimer's Association criteria (NIA-AA). The diagnostic characteristics of Mini-Cog, including sensitivity, specificity, PPV, NPV, especially the Youden index, performed well, even better than the combinations of several screening tests. The Mini-Cog with excellent screening characteristics, spending less time, could be considered to be used as a screening test to help to screen patients with cognitive impairment or dementia early. And Bayesian method was shown to be a suitable tool for evaluating dementia screening tests. The Mini-Cog with excellent screening characteristics, spending less time, could be considered to be used as a screening test to help to screen patients with cognitive impairment or dementia early. And Bayesian method was shown to be a suitable tool for evaluating dementia screening tests.

Computational study on the functionalization of BNNC with pyrrole molecule

Science.gov (United States)

Payvand, Akram; Tavangar, Zahra

2018-05-01

The functionalization of the boron nitride nanocone (BNNC) by pyrrole molecule was studied using B3LYP/6-311+G(d) level of theory. The reaction was studied in three methods in different layers of the nanocone: Diels-Alder cycloaddition, quartet cycloaddition and the reaction of the nitrogen atom of the pyrrole molecule with the boron or nitrogen atom of the BNNC. Thermodynamic quantities, Chemical hardness and potential and electrophilicity index of the functionalized BNNC were studied. The results show that the tip of nanocone has a higher tendency for participation in the reaction and the most favorable product of the reaction between BNNC and pyrrole molecule is produced from the reaction of N atom of pyrrole with the B atom of BNNC. The reaction decreases the energy gap value which leads to increasing the reactivity and conductivity of functionalized nanocone. The calculated NICS values confirm the aromaticity in the pristine nanocone as well as in the functionalized nanocone.

Investigation of Self-Assembly Processes for Chitosan-Based Coagulant-Flocculant Systems: A Mini-Review

Directory of Open Access Journals (Sweden)

Savi Bhalkaran

2016-09-01

Full Text Available The presence of contaminants in wastewater poses significant challenges to water treatment processes and environmental remediation. The use of coagulation-flocculation represents a facile and efficient way of removing charged particles from water. The formation of stable colloidal flocs is necessary for floc aggregation and, hence, their subsequent removal. Aggregation occurs when these flocs form extended networks through the self-assembly of polyelectrolytes, such as the amine-based polysaccharide (chitosan, which form polymer “bridges” in a floc network. The aim of this overview is to evaluate how the self-assembly process of chitosan and its derivatives is influenced by factors related to the morphology of chitosan (flocculant and the role of the solution conditions in the flocculation properties of chitosan and its modified forms. Chitosan has been used alone or in conjunction with a salt, such as aluminum sulphate, as an aid for the removal of various waterborne contaminants. Modified chitosan relates to grafted anionic or cationic groups onto the C-6 hydroxyl group or the amine group at C-2 on the glucosamine monomer of chitosan. By varying the parameters, such as molecular weight and the degree of deacetylation of chitosan, pH, reaction and settling time, dosage and temperature, self-assembly can be further investigated. This mini-review places an emphasis on the molecular-level details of the flocculation and the self-assembly processes for the marine-based biopolymer, chitosan.

Advances towards aromatic oligoamide foldamers

DEFF Research Database (Denmark)

Hjelmgaard, Thomas; Plesner, Malene; Dissing, Mette Marie

2014-01-01

We have efficiently synthesized 36 arylopeptoid dimers with ortho-, meta-, and para-substituted aromatic backbones and tert-butyl or phenyl side chains. The dimers were synthesized by using a "submonomer method" on solid phase, by applying a simplified common set of reaction conditions. X......-ray crystallographic analysis of two of these dimers disclosed that the tert-butyl side chain invokes a cis amide conformation with a comparatively more closely packed structure of the surrounding aromatic backbone while the phenyl side chain results in a trans amide conformation with a more open, extended structure...... of the surrounding aromatic backbone. Investigation of the X-ray structures of two arylopeptoid dimers disclosed that the tert-butyl side chain invokes a cis amide conformation with a closely packed structure of the surrounding aromatic backbone while the phenyl side chain results in a trans amide conformation...

Risperidone oral disintegrating mini-tablets: A robust-product for pediatrics.

Science.gov (United States)

El-Say, Khalid M; Ahmed, Tarek A; Abdelbary, Maged F; Ali, Bahaa E; Aljaeid, Bader M; Zidan, Ahmed S

2015-12-01

This study was aimed at developing risperidone oral disintegrating mini-tablets (OD-mini-tablets) as age-appropriate formulations and to assess their suitability for infants and pediatric use. An experimental Box-Behnken design was applied to assure high quality of the OD-mini-tablets and reduce product variability. The design was employed to understand the influence of the critical excipient combinations on the production of OD-mini-tablets and thus guarantee the feasibility of obtaining products with dosage form uniformity. The variables selected were mannitol percent in Avicel (X1), swelling pressure of the superdisintegrant (X2), and the surface area of Aerosil as a glidant (X3). Risperidone-excipient compatibilities were investigated using FTIR and the spectra did not display any interaction. Fifteen formulations were prepared and evaluated for pre- and post-compression characteristics. The prepared OD-mini-tablet batches were also assessed for disintegration in simulated salivary fluid (SSF, pH 6.2) and in reconstituted skimmed milk. The optimized formula fulfilled the requirements for crushing strength of 5 kN with minimal friability, disintegration times of 8.4 and 53.7 s in SSF and skimmed milk, respectively. This study therefore proposes the risperidone OD-mini-tablet formula having robust mechanical properties, uniform and precise dosing of medication with short disintegration time suitable for pediatric use.

Comparison of retrograde intrarenal surgery and mini-percutaneous nephrolithotomy in management of lower-pole renal stones with a diameter of smaller than 15 mm.

Science.gov (United States)

Kirac, Mustafa; Bozkurt, Ömer Faruk; Tunc, Lutfi; Guneri, Cagri; Unsal, Ali; Biri, Hasan

2013-06-01

The aim of this study was to compare the outcomes of retrograde intrarenal surgery (RIRS) and miniaturized percutaneous nephrolithotomy (mini-PNL) in management of lower-pole renal stones with a diameter smaller than 15 mm. Between December 2009 and July 2012, the patients with the diagnosis of lower-pole stones were evaluated by ultrasonography, intravenous pyelography and computed tomography. The records of 73 evaluable patients who underwent mini-PNL (n = 37) or RIRS (n = 36) for lower-pole (LP) stones with diameter smaller than 15 mm were reviewed retrospectively. Of the 73 patients, 37 underwent mini-PNL and 36 underwent RIRS. The stone-free rates were 89.1 and 88.8 % for mini-PNL and RIRS groups, respectively. The mean operation time was 53.7 ± 14.5 in the mini-PNL group but 66.4 ± 15.8 in the RIRS group (P = 0.01). The mean fluoroscopy times and hospitalization times were significantly higher in the mini-PNL group. There was no major complication in any patient. RIRS and mini-PNL are safe and effective methods for treatment of LP calculi with a diameter smaller than 15 mm. RIRS is a non-invasive and feasible treatment option, and has also short hospitalization time, low morbidity and complication rate. It may be an alternative of mini-PNL in the treatment LP calculi with smaller than 15 mm.

Low carbon mini grids 'Identifying the gaps; building the evidence base', Support Study for DFID - Final Report

International Nuclear Information System (INIS)

2013-11-01

This report represents the final report on the support study on 'Identifying the gaps and building the evidence base on low carbon mini-grids'. The review forms part of a preliminary initiative of DFID to promote Green Mini-Grids (GMG) in Africa under the International Climate Fund (ICF) with the objective of providing guidance and recommendations for DFID intervention and program implementation. The support study started in November 2012 and ended in September 2013. The report is based on activities which have included kick-off meetings, development of the methodological framework, literature and web review of documents relevant to the state-of-the-art practices for mini-grids, collation of relevant international experience, and a field visit in 2 targeted African countries (Kenya and Mozambique) to conduct interviews with key stakeholders and to collect field data. The report is structured in 8 chapters as per the requirements of the TOR, with a 'Highlights' section: 1- International Review of Mini-Grids and Data Collection, overview of the technologies, and of implementation schemes. The reality of the target countries is that while there are a number of diesel based mini-grids run either by private operators with low service and high cost, outside any regulated framework, and some run through various forms of Public Private Partnerships, there are extremely few Green Mini-Grids. Some Renewable Energy Power Generation operations are found to be for self-consumption or feeding into the grid, but very seldom for powering a Mini-Grid isolated from the interconnected network. 2 - Relevance of Mini-Grid Solutions, proposes an approach to help the planner identify whether in a given country/region, Mini-Grids - and further Green Mini-Grids are a viable option for access to electricity services. These mini-grid areas are those which will remain out reach of the interconnected grid for a few years to come, and yet where there is sufficient load density to ensure the

Accelerated Tooth Movement with Orthodontic Mini-Screws

Directory of Open Access Journals (Sweden)

S. Aksakalli

2017-01-01

Full Text Available This case report outlines the possibility of accelerated tooth movement with the combination of microosteoperforation and mini-screws. A 14-year-old male patient presented Class II malocclusion with maxillary incisor protrusion. Upper first premolars were extracted, and after leveling, accelerated canine distalization started. For pre- and postdistalization times, amount of distalization, periodontal health, and root resorption were assessed. Within the limitations of this case report, micro-osteoperforations with mini-screw have a potential for shortening the treatment time.

Adsorption of polynuclear aromatic hydrocarbons from aqueous solution: Agrowaste-modified kaolinite vs surfactant modified bentonite

Directory of Open Access Journals (Sweden)

E. I. Unuabonah

2017-01-01

Full Text Available The adsorption efficiency of a new hybrid clay adsorbent for polynuclear aromatic hydrocarbons (PAHs is compared with known modified clay adsorbents. The new hybrid clay adsorbent (HYCA showed far higher adsorption capacities for the adsorption of various PAH molecules compared with sodium dodecyl sulfate modified and humic acid modified Bentonite clay adsorbents. With the new hybrid clay adsorbent (HYCA, the adsorption of some of the larger PAH molecules was complete in the first 1 h as compared with ≈ 62% and ≈ 76% observed for both humic acid modified and sodium dodecyl sulfate modified Bentonite clay adsorbents respectively. In 24 h adsorption of the PAHs was complete for all adsorbents with HYCA adsorbent showing better efficiency in the removal of the PAH molecules from aqueous solutions. No significant change was observed with increase in time up to 48 h. The adsorption was observed to be more spontaneous with HYCA adsorbent than with either modified Bentonite adsorbents. The enthalpy of adsorption did not follow any specific order and were not consistent for all PAH molecules considered.

Predicting everyday functional abilities of dementia patients with the Mini-Mental State Examination.

Science.gov (United States)

Razani, Jill; Wong, Jennifer T; Dafaeeboini, Natalia; Edwards-Lee, Terri; Lu, Po; Alessi, Cathy; Josephson, Karen

2009-03-01

The Mini-Mental State Examination is a widely used cognitive screening measure. The purpose of the present study was to assess how 5 specific clusters of Mini-Mental State Examination items (ie, subscores) correlate with and predict specific areas of daily functioning in dementia patients, 61 patients with varied forms of dementia were administered the Mini-Mental State Examination and an observation-based daily functional test (the Direct Assessment of Functional Status). The results revealed that the orientation and attention subscores of the Mini-Mental State Examination correlated most significantly with most functional domains. The Mini-Mental State Examination language items correlated with all but the shopping and time orientation tasks, while the Mini-Mental State Examination recall items correlated with the Direct Assessment of Functional Status time orientation and shopping tasks. Stepwise regression analyses found that among the Mini-Mental State Examination subscores, orientation was the single, best independent predictor of daily functioning.

Validity of a short clinical interview for psychiatric diagnosis: the mini-SCAN.

Science.gov (United States)

Nienhuis, F J; van de Willige, G; Rijnders, C A Th; de Jonge, P; Wiersma, D

2010-01-01

To promote clinical application of the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) system a shorter version (the mini-SCAN) was devised. Its psychometric properties were unknown. To establish the validity and practical properties of the mini-SCAN. One hundred and six participants were interviewed twice, once with the SCAN and once with the mini-SCAN. The level of agreement was established for the categories: no disorder, affective disorders, anxiety disorders, non-affective psychotic disorders, affective psychotic disorders. The mini-SCAN is a valid instrument. Most kappa values were around 0.90. Only for the class of affective psychotic disorders was the agreement moderate. Mean duration of the mini-SCAN interviews was 25 min shorter than the SCAN interviews. Participants and interviewers were generally satisfied with the interview format and questions. The mini-SCAN can be used as a diagnostic instrument for clinical purposes and for clinical studies when the present episode is the focus of attention.

Why are mini-implants lost: the value of the implantation technique!

Science.gov (United States)

Romano, Fabio Lourenço; Consolaro, Alberto

2015-01-01

The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1) Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2) Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3) Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4) The more precise the lancing procedures, the better the implant placement technique; 5) Self-drilling does not mean higher pressures; 6) Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

Why are mini-implants lost: The value of the implantation technique!

Directory of Open Access Journals (Sweden)

Fabio Lourenço Romano

2015-02-01

Full Text Available The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1 Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2 Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3 Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4 The more precise the lancing procedures, the better the implant placement technique; 5 Self-drilling does not mean higher pressures; 6 Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

Peer Reviewer

OpenAIRE

Baru Mansjur, Mansjur

2016-01-01

- Peer Reviewer Effects Of Histomorohometric, Bone Tu Implant Contac and Asseointegration On a novel Hybrid Micro/Nano Topografhy Modfie Dental Implant in The Mandibular Canine Premolar Area Of The Mini Pigs

An EPR study of positive hole transfer and trapping in irradiated frozen solutions containing aromatic traps

International Nuclear Information System (INIS)

Egorov, A.V.; Zezin, A.A.; Feldman, V.I.

2002-01-01

Complete text of publication follows. Processes of positive hole migration and trapping are of basic significance for understanding of the primary events in the radiation chemistry of solid molecular systems. Specific interest is concerned with the case, when ionization energies of 'hole traps' are rather close, so one may expect 'fine tuning' effects resulting from variations in conformation, weak interactions, molecular packing, etc. In this contribution we report the results of EPR study of formation of radical cations in irradiated frozen halocarbon solutions containing aromatic molecules of different structure. Using the 'two-trap' model made it possible to obtain an evidence for efficient long-range trap-to-trap positive hole transfer between alkyl benzene molecules with close ionization energies distributed in the matrices with high ionization potentials. The distance of transfer was found to be 2-4 nm. In the case of frozen solutions containing ethylbenzene and toluene, it was found that the efficiency and direction of hole transfer was controlled by the conformation of ethylbenzene radical cation. The study of positive hole localization in 'bridged' diphenyls of Ph(CH 2 ) n Ph type revealed that the structure of radical cations of these species was affected by local environment (type of halocarbon matrix) and the conformational flexibility of 'bridge'. In summary, we may conclude that migration and localization of positive hole in rigid systems containing aromatic 'traps' is quite sensitive to rather subtle effects. This conclusion may be of common significance for the radiation chemistry of systems with physical dispersion of the traps of similar chemical structure (e.g. macromolecules, adsorbed molecules, etc.)

In silico and experimental methods revealed highly diverse bacteria with quorum sensing and aromatics biodegradation systems--a potential broad application on bioremediation.

Science.gov (United States)

Huang, Yili; Zeng, Yanhua; Yu, Zhiliang; Zhang, Jing; Feng, Hao; Lin, Xiuchun

2013-11-01

Phylogenetic overlaps between aromatics-degrading bacteria and acyl-homoserine-lactone (AHL) or autoinducer (AI) based quorum-sensing (QS) bacteria were evident in literatures; however, the diversity of bacteria with both activities had never been finely described. In-silico searching in NCBI genome database revealed that more than 11% of investigated population harbored both aromatic ring-hydroxylating-dioxygenase (RHD) gene and AHL/AI-synthetase gene. These bacteria were distributed in 10 orders, 15 families, 42 genus and 78 species. Horizontal transfers of both genes were common among them. Using enrichment and culture dependent method, 6 Sphingomonadales and 4 Rhizobiales with phenanthrene- or pyrene-degrading ability and AHL-production were isolated from marine, wetland and soil samples. Thin-layer-chromatography and gas-chromatography-mass-spectrum revealed that these Sphingomonads produced various AHL molecules. This is the first report of highly diverse bacteria that harbored both aromatics-degrading and QS systems. QS regulation may have broad impacts on aromatics biodegradation, and would be a new angle for developing bioremediation technology. Copyright © 2013 Elsevier Ltd. All rights reserved.

Pulsed laser study of excited states of aromatic molecules absorbed in globular proteins

International Nuclear Information System (INIS)

Cooper, M.; Thomas, J.K.

1977-01-01

Pyrene and several derivatives of pyrene such as pyrene sulfonic acid, and pyrene butyric acid were incorporated into bovine serum albumin (BSA) in aqueous solution. The pyrene chromophore was subsequently excited by a pulse of uv light (lambda = 3471 A) from a Q switched frequency doubled ruby laser. The lifetime of the pyrene excited singlet and triplet states were monitored by time resolved spectrophotometry. Various molecules, such as O 2 and I - , dissolved in the aqueous phase, diffused into the protein and quenched pyrene excited states. The rates of these reactions were followed under a variety of conditions such as pH and temperature and in the presence of inert additives. The rates of pyrene excited-state quenching were often considerably smaller than the rates observed in simple solutions. A comparison of the rates in the protein and homogeneous solutions gives information on the factors such as temperature, charge, and pH that control the movement of small molecules in and into BSA

Influence of different implant materials on the primary stability of orthodontic mini-implants.

Science.gov (United States)

Pan, Chin-Yun; Chou, Szu-Ting; Tseng, Yu-Chuan; Yang, Yi-Hsin; Wu, Chao-Yi; Lan, Ting-Hsun; Liu, Pao-Hsin; Chang, Hong-Po

2012-12-01

This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft(3) trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates(®) device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05). Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success. Copyright © 2012. Published by Elsevier B.V.

Influence of different implant materials on the primary stability of orthodontic mini-implants

Directory of Open Access Journals (Sweden)

Chin-Yun Pan

2012-12-01

Full Text Available This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm. The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft3 trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates® device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05. Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success.

Delphi report 1995 on developments in science and technology. Mini Delphi; Delphi-Bericht 1995 zur Entwicklung von Wissenschaft und Technik. Mini-Delphi

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

In August 1993 the first German `Delphi Report on Developments in Science and Technology` was published. It was elaborated by the Fraunhofer Institute for System Engineering and Innovation Research (FhG-ISI) in cooperation with the Japanese National Institute of Science and Technology Policy (NISTEP). The `MINI-DELPHI` now completed by FhG-ISI, again in cooperation with NISTEP, is a further development of the Delphi approach in that it is more differentiated in its questions and assessment criteria than its predecessors. `MINI-DELPHI` is not intended as a comprehensive forecast on technology in general but rather focusses on key topics. Its emphasis is on technology demand and the relevance of technologies to social issues. Although the Mini-Delphi study was primarily aimed at further refining the methodology employed, it nevertheless contains a wealth of information and details on circumscript questions. The requisite database is provided by tables on the results of two inquiry rounds among Japanese and German experts. (orig./RHM) [Deutsch] Im August 1993 wurde der erste deutsche `Delphi-Bericht zur Entwicklung von Wissenschaft und Technik` veroeffentlicht. Er war vom Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (FhG-ISI) in Zusammenarbeit mit dem japanischen National Institute of Science and Technology Policy (NISTEP) erarbeitet worden. Mit dem jetzt vorliegenden `MINI-DELPHI` hat das FhG-ISI - wieder in Zusammenarbeit mit dem NISTEP - den Delphi-Ansatz fortentwickelt und sowohl hinsichtlich der Fragen als auch der Beurteilungskriterien weiter ausdifferenziert. `MINI-DELPHI` bezweckt keine umfassende Technologievorausschau, sondern konzentriert sich auf Schluesselthemen. Im Vordergrund steht der Gedanke des Technikbedarfs und die Relevanz fuer gesellschaftliche Fragestellungen. Obwohl die Mini-Delphi-Studie vorrangig der Weiterentwicklung der Methodik dient, enthaelt sich eine Fuelle von Informationen und Details zu Einzelfragen. Die im Bericht

Designing a mini subcritical nuclear reactor

International Nuclear Information System (INIS)

Escobedo G, C. R.; Vega C, H. R.; Davila H, V. M.

2015-10-01

In this work the design of a mini subcritical nuclear reactor formed by means of light water moderator, uranium as fuel, and isotopic neutron source of 239 PuBe was carried out. The design was done by Monte Carlo methods with the code MCNP5 in which uranium was modeled in an array of concentric holes cylinders of 8.5, 14.5, 20.5, 26.5, 32.5 cm of internal radius and 3 cm of thickness, 36 cm of height. Different models were made from a single fuel cylinder (natural uranium) to five. The neutron source of 239 PuBe was situated in the center of the mini reactor; in each arrangement was used water as moderator. Cross sections libraries Endf/Vi were used and the number of stories was large enough to ensure less uncertainty than 3%. For each case the effective multiplication factor k e -f f , the amplification factor and the power was calculated. Outside the mini reactor the ambient dose equivalent H (10) was calculated for different cases. The value of k eff , the amplification factor and power are directly related to the number of cylinders of uranium as fuel. Although the average energy of the neutrons 239 PuBe is between 4.5 and 5 MeV in the case of the mini reactor for a cylinder, in the neutron spectrum the presence of thermal neutrons does not exist, so that produced fissions are generated with fast neutrons, and in designs of two and three rings the neutron spectra shows the presence of thermal neutrons, however the fissions are being generated with fast neutrons. Finally in the four and five cases the amount of moderator is enough to thermalized the neutrons and thereby produce the fission. The maximum value for k eff was 0.82; this value is very close to the assembly of Universidad Autonoma de Zacatecas generating a k eff of 0.86. According to the safety and radiation protection standards for the design of mini reactor of one, two and three cylinders they comply with the established safety, while designs of four and five cylinders not met. (Author)

3-Econsystems: MicroRNAs, Receptors, and Latent Viruses; Some Insights Biology Can Gain from Economic Theory.

Science.gov (United States)

Polansky, Hanan; Javaherian, Adrian

2016-01-01

This mini-review describes three biological systems. All three include competing molecules and a limiting molecule that binds the competing molecules. Such systems are extensively researched by economists. In fact, the issue of limited resources is the defining feature of economic systems. Therefore, we call these systems "econsystems." In an econsystem, the allocation of the limiting molecule between the competing molecules determines the behavior of the system. A cell is an example of an econsystem. Therefore, a change in the allocation of a limiting molecule as a result of, for instance, an abnormal change in the concentration of one of the competing molecules, may result in abnormal cellular behavior, and disease. The first econsystem described in this mini-review includes a long non-coding RNA and a messenger RNA (lncRNA and mRNA). The limiting molecule is a microRNA (miRNA). The lncRNA and mRNA are known as competing endogenous RNAs (ceRNAs). The second econsystem includes two receptors, and the limiting molecule is a ligand. The third econsystem includes a cis-regulatory element of a latent virus and that of a human gene. The limiting molecule is a transcription complex that binds both cis-elements.

Growth and Destruction of PAH Molecules in Reactions with Carbon Atoms

Energy Technology Data Exchange (ETDEWEB)

Krasnokutski, Serge A.; Huisken, Friedrich; Jäger, Cornelia; Henning, Thomas [Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Helmholtzweg 3, D-07743 Jena (Germany)

2017-02-10

A very high abundance of atomic carbon in the interstellar medium (ISM), and the high reactivity of these species toward different hydrocarbon molecules including benzene, raise questions regarding the stability of polycyclic aromatic hydrocarbon (PAH) molecules in space. To test the efficiency of destruction of PAH molecules via reactions with atomic carbon, we performed a set of laboratory and computational studies of the reactions of naphthalene, anthracene, and coronene molecules with carbon atoms in the ground state. The reactions were investigated in liquid helium droplets at T = 0.37 K and by quantum chemical computations. Our studies suggest that all small and all large catacondensed PAHs react barrierlessly with atomic carbon, and therefore should be efficiently destroyed by such reactions in a broad temperature range. At the same time, large compact pericondensed PAHs should be more inert toward such a reaction. In addition, taking into account their higher photostability, much higher abundances of pericondensed PAHs should be expected in various astrophysical environments. The barrierless reactions between carbon atoms and small PAHs also suggest that, in the ISM, these reactions could lead to the bottom-up formation of PAH molecules.

Prehispanic Functional Foods and Nutraceuticals in the Treatment of Dyslipidemia Associated to Cardiovascular Disease: a Mini-Review.

Science.gov (United States)

Ríos-Hoyo, Alejandro; Romo-Araiza, Alejandra; Meneses-Mayo, Marcos; Guttiérrez-Salmeán, Gabriela

2017-01-27

Dyslipidemia is an important modifi able risk factor for cardiovascular and metabolic diseases, which are responsible for a large number of mortality and disability cases around the globe. Different strategies have been used within the treatment of dyslipidemia, including lifestyle modifi cations, pharmacologic therapy, as well as functional foods and nutraceuticals. Functional foods have been used worldwide since ancient times, particularly, the prehispanic civilizations utilized several as medicinal foods. In the current pandemic of dyslipidemia as well as the nutritional transition, particularly in Latin America, the use of native functional foods represents an attractive target for the treatment and/ or prevention of these conditions. In this mini-review, evidence regarding different functional foods such as cacao, amaranth, chia, nopal, spirulina, as well as their nutraceutical compounds, including fl avonoids, omega-3 PUFAs, fi ber, prebiotics, lovastatin, c-phycocyanin, among others, and their mechanism of action are presented and discussed. Although such foods certainly are considered as attractive potential agents to target dyslipidemia thus decrease the associated cardiometabolic risk, we conclude that for most of the presented functional foods there is currently not enough evidence to support its recommendation and every-day use.

[Use of the Mini-Mental State Examination in research on the elderly in Brazil: a systematic review].

Science.gov (United States)

de Melo, Denise Mendonça; Barbosa, Altemir José Gonçalves

2015-12-01

The Mini-Mental State Examination (MMSE) is the most widely used cognitive screening test around the world. In Brazil, different MMSE versions and many cut-off points have been used. A systematic review of papers indexed in Scielo was conducted in order to analyze use of the MMSE in Brazilian empirical studies with elderly people. To search for these texts, the complete name of the instrument and its abbreviation were used. A growth trend in the scientific production during the 1998 to 2013 period was observed. Eleven versions of the MMSE were identified and the Bertolucci et al. version was the most cited. Over half of the studies used schooling as the criteria to establish cut-off points. The studies were predominantly conducted using samples recruited from large cities in the Southeastern region and in the community. Despite the growing trend of research with the elderly using the MMSE, the psychometric properties of this scale of measurement have been the subject of little investigation. Despite the widespread use of the MMSE in Brazil, there is a lack of standardization and evidence of validity for this this scale of measurement.

Internal Structure of Mini-CEX Scores for Internal Medicine Residents: Factor Analysis and Generalizability

Science.gov (United States)

Cook, David A.; Beckman, Thomas J.; Mandrekar, Jayawant N.; Pankratz, V. Shane

2010-01-01

The mini-CEX is widely used to rate directly observed resident-patient encounters. Although several studies have explored the reliability of mini-CEX scores, the dimensionality of mini-CEX scores is incompletely understood. Objective: Explore the dimensionality of mini-CEX scores through factor analysis and generalizability analysis. Design:…

Mini-Digest of Education Statistics, 2008. NCES 2009-021

Science.gov (United States)

Snyder, Thomas D.

2009-01-01

This publication is the 14th edition of the "Mini-Digest of Education Statistics," a pocket-sized compilation of statistical information covering the broad field of American education from kindergarten through graduate school. The "Mini-Digest" is designed as an easy reference for materials found in much greater detail in the…

Fibrous mini-collagens in hydra nematocysts.

Science.gov (United States)

Holstein, T W; Benoit, M; Herder, G V; David, C N; Wanner, G; Gaub, H E

1994-07-15

Nematocysts (cnidocysts) are exocytotic organelles found in all cnidarians. Here, atomic force microscopy and field emission scanning electron microscopy reveal the structure of the nematocyst capsule wall. The outer wall consists of globular proteins of unknown function. The inner wall consists of bundles of collagen-like fibrils having a spacing of 50 to 100 nanometers and cross-striations at intervals of 32 nanometers. The fibrils consist of polymers of "mini-collagens," which are abundant in the nematocysts of Hydra. The distinct pattern of mini-collagen fibers in the inner wall can provide the tensile strength necessary to withstand the high osmotic pressure (15 megapascals) in the capsules.

Concerning production and decay of mini black holes

CERN Document Server

Hajdukovic, D

2007-01-01

In the next few years, theories predicting possibility to create mini black holes will be tested at CERN. Either experimental verification or rejection of these theories is of great scientific importance. There is a large consensus that, if successfully created, these short living mini black holes will decay through thermal (Hawking's) radiation. In the present comment we point out, that under assumption of the gravitational repulsion between matter and antimatter (in short we call it antigravity), thermal radiation may be dominated by a non-thermal radiation (being the consequence of pair creation from the vacuum, by gravitational field, which in the case of antigravity, pushes particles and antiparticles in opposite directions). Thus, the eventual creation of mini black holes may turn to be an unexpected opportunity to test the existence of antigravity.

Role of the Human Breast Milk-Associated Microbiota on the Newborns' Immune System: A Mini Review.

Science.gov (United States)

Toscano, Marco; De Grandi, Roberta; Grossi, Enzo; Drago, Lorenzo

2017-01-01

The human milk is fundamental for a correct development of newborns, as it is a source not only of vitamins and nutrients, but also of commensal bacteria. The microbiota associated to the human breast milk contributes to create the "initial" intestinal microbiota of infants, having also a pivotal role in modulating and influencing the newborns' immune system. Indeed, the transient gut microbiota is responsible for the initial change from an intrauterine Th2 prevailing response to a Th1/Th2 balanced one. Bacteria located in both colostrum and mature milk can stimulate the anti-inflammatory response, by stimulating the production of specific cytokines, reducing the risk of developing a broad range of inflammatory diseases and preventing the expression of immune-mediated pathologies, such as asthma and atopic dermatitis. The aim of the present Mini Review is to elucidate the specific immunologic role of the human milk-associated microbiota and its impact on the newborn's health and life, highlighting the importance to properly study the biological interactions in a bacterial population and between the microbiota and the host. The Auto Contractive Map, for instance, is a promising analytical methodology based on artificial neural network that can elucidate the specific role of bacteria contained in the breast milk in modulating the infants' immunological response.

Optical aptasensors for quantitative detection of small biomolecules: a review.

Science.gov (United States)

Feng, Chunjing; Dai, Shuang; Wang, Lei

2014-09-15

Aptasensors are aptamer-based biosensors with excellent recognition capability towards a wide range of targets. Specially, there have been ever-growing interests in the development of aptasensors for the detection of small molecules. This phenomenon is contributed to two reasons. On one hand, small biomolecules play an important role in living organisms with many kinds of biological function, such as antiarrhythmic effect and vasodilator activity of adenosine. On the other hand, the concentration of small molecules can be an indicator for disease diagnosis, for example, the concentration of ATP is closely associated with cell injury and cell viability. As a potential analysis tool in the construction of aptasensors, optical analysis has attracted much more interest of researchers due to its high sensitivity, quick response and simple operation. Besides, it promises the promotion of aptasensors in performance toward a new level. Review the development of optical aptasensors for small biomolecules will give readers an overall understanding of its progress and provide some theoretical guidelines for its future development. Hence, we give a mini-review on the advance of optical aptasensors for small biomolecules. This review focuses on recent achievements in the design of various optical aptasensors for small biomolecules, containing fluorescence aptasensors, colorimetric aptasensors, chemiluminescence aptasensors and other optical aptasensors. Copyright © 2014 Elsevier B.V. All rights reserved.

On structure of some laminated crystals with organic molecules

International Nuclear Information System (INIS)

Volodina, G.F.; Ivanova, V.Ya.; Malinovskij, T.I.

1982-01-01

A survey is made of papers dealing with intercalation of organic molecules into crystals of dihalcogenides of some transition metals (TaS 2 , TiS 2 , NbS 2 , ZrS 2 , TaSe 2 ), variation of their structure and physical properties. Among the used intercalates ammonia, pyridine, aniline and other aromatic amines proved to be most satisfactory from the viewpoint of reaction rate and product stability. A possibility is discussed of intercalation into PbI 2 and CdI 2 crystals that are of the same structural type as dihalcogenides

Replacing a failed mini-implant with a miniplate to prevent interruption during orthodontic treatment.

Science.gov (United States)

Lee, Jin-Hwa; Choo, Hyeran; Kim, Seong-Hun; Chung, Kyu-Rhim; Giannuzzi, Lucille A; Ngan, Peter

2011-06-01

When mini-implants fail during orthodontic treatment, there is a need to have a backup plan to either replace the failed implant in the adjacent interradicular area or wait for the bone to heal before replacing the mini-implant. We propose a novel way to overcome this problem by replacement with a miniplate so as not to interrupt treatment or prolong treatment time. The indications, advantages, efficacy, and procedures for switching from a mini-implant to a miniplate are discussed. Two patients who required replacement of failed mini-implants are presented. In the first patient, because of the proximity of the buccal vestibule to the mini-implant, it was decided to replace the failed mini-implant by an I-shaped C-tube miniplate. In the second patient, radiolucencies were found around the failed mini-implants, making the adjacent alveolar bone unavailable for immediate placement of another mini-implant. In addition, the maxillary sinus pneumatization was expanded deeply into the interradicular spaces; this further mandated an alternative placement site. One failed mini-implant was examined under a scanning electron microscope for bone attachment. Treatment was completed in both patients after replacement with miniplates without interrupting the treatment mechanics or prolonging the treatments. Examination under the scanning electron microscope showed partial bone growth into the coating pores and titanium substrate interface even after thorough cleaning and sterilization. Replacement with a miniplate is a viable solution for failed mini-implants during orthodontic treatment. The results from microscopic evaluation of the failed mini-implant suggest that stringent guidelines are needed for recycling used mini-implants. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Evaluation of mini super computers for nuclear design applications

International Nuclear Information System (INIS)

Altomare, S.; Baradari, F.

1987-01-01

The evolution of the mini super computers will force changes from the current environment of performing nuclear design calculations on mainframe computers (such as a CRAY) to mini super computers. This change will come about for a number of reasons. First, the mini super computers currently available in the marketplace offer the power and speed comparable to mainframes and can provide the capability to support highly computer intensive calculations. Second, the equipment is physically smaller and can easily be installed and operated without extensive investments in facilities and operations support. Third, the computer capacity can be acquired with as much needed memory, disk, and tape capacity as may be needed. Another reasons is that the performance/cost ratio has increased drastically as hardware costs have decreased. A study was conducted at the Westinghouse Commercial Nuclear Fuel Division (CNFD) to evaluate the mini super computers for use in nuclear core design. As a result of this evaluation, Westinghouse CNFD is offering a combined hardware/software technology transfer package for core design. This package provides the utility designer with a totally dedicated mini super computer comparable in speed to the CRAY 1S with sufficient capacity for a sizable design group to perform the engineering activities related to nuclear core design and operations support. This also assures the utility of being totally compatible with the CNFD design codes, thus assuring total update compatibility

Determination and theoretical analysis of supercritical fluid chromatographic retention of polycyclic aromatic hydrocarbons in a polymeric smectic phase

International Nuclear Information System (INIS)

Chao Yan; Martire, D.E.

1992-01-01

A mean-field lattice model is used to describe the partitioning of blocklike molecules between an isotropic mobile phase and an anisotropic stationary phase in chromatography by applying it to supercritical fluid retention of polycyclic aromatic hydrocarbons in a polymeric smectic phase. This concludes that the logarithm of the capacity factor (1) increases linearly with increasing reciprocal temperature, (2) decreases with increasing mobile phase density more rapidly for solute molecules with a relatively larger contact area with the mobile phase, and (3) is a linear function of the minimum area. The van't Hoff plot slope is also determined to be more negative for solute molecules with a relatively larger ratio of contact area with the stationary phase versus the mobile phase. 18 refs., 9 figs., 5 tabs

Unexpected solvent effects on the UV/Vis absorption spectra of o-cresol in toluene and benzene: in contrast with non-aromatic solvents.

Science.gov (United States)

Zheng, Dong; Yuan, Xiang-Ai; Ma, Haibo; Li, Xiaoxiong; Wang, Xizhang; Liu, Ziteng; Ma, Jing

2018-03-01

Cresol is a prototype molecule in understanding intermolecular interactions in material and biological systems, because it offers different binding sites with various solvents and protonation states under different pH values. It is found that the UV/Vis absorption spectra of o -cresol in aromatic solvents (benzene, toluene) are characterized by a sharp peak, unlike the broad double-peaks in 11 non-aromatic solvents. Both molecular dynamics simulations and electronic structure calculations revealed the formation of intermolecular π-complexation between o -cresol and aromatic solvents. The thermal movements of solvent and solute molecules render the conformations of o -cresol changing between trans and cis isomers. The π-interaction makes the cis configuration a dominant isomer, hence leading to the single keen-edged UV/Vis absorption peak at approximately 283 nm. The free conformation changes between trans and cis in aqueous solution rationalize the broader absorption peaks in the range of 260-280 nm. The pH dependence of the UV/Vis absorption spectra in aqueous solutions is also rationalized by different protonation states of o -cresol. The explicit solvent model with long-ranged interactions is vital to describe the effects of π-complexation and electrostatic interaction on the UV/Vis absorption spectra of o -cresol in toluene and alkaline aqueous (pH > 10.3) solutions, respectively.

Mini-clinical evaluation exercise til evaluering af kommunikation og samarbejde i ambulatoriet

DEFF Research Database (Denmark)

Eriksen, Jesper Grau; Simonsen, Dorit; Bastholt, Lars

2009-01-01

INTRODUCTION: In the revised Danish medical specialist training increased focus has been placed on competences which are hard to evaluate such as communication skills. Mini-CEX seems promising as an evaluation tool. Our aim was to test: 1) whether mini-CEX was useable in the evaluation of communi......INTRODUCTION: In the revised Danish medical specialist training increased focus has been placed on competences which are hard to evaluate such as communication skills. Mini-CEX seems promising as an evaluation tool. Our aim was to test: 1) whether mini-CEX was useable in the evaluation...

Injuries in Japanese Mini-Basketball Players During Practices and Games

Science.gov (United States)

Kuzuhara, Kenji; Shibata, Masashi; Uchida, Ryo

2016-01-01

Context: Mini-basketball is one of the most popular junior sports in Japan. Mini-basketball–related injuries may increase because of early specialization. However, no reports have been published to date concerning basketball injuries in children younger than 12 years of age. Objective: To prospectively study the incidence, sites, types, and mechanisms of injuries in mini-basketball teams. Design: Descriptive epidemiology study. Setting: Mini-basketball teams in Kobe, Japan. Patients or Other Participants: A total of 95 players in 7 community-based mini-basketball club teams (age range, 9 through 12 years). Main Outcome Measure(s): Data on all practice and game injuries for the 2013–2014 season were collected using an injury report form. Injury rates were calculated according to site, type, and mechanism. Results: The overall injury rate was 3.83 per 1000 athlete-hours (AHs). The game injury rate (12.92/1000 AHs) was higher than the practice injury rate (3.13/1000 AHs; P basketball players. The high practice injury rate in this study may be due to specific factors related to growth, such as individual differences in height, or to skills, such as inexperience in ball handling. PMID:27922287

Gender and Self-Employment: The Role of Mini-Companies

Science.gov (United States)

Johansen, Vegard

2016-01-01

Purpose: The purpose of this paper is to evaluate to what degree participation in mini-companies impact young women and men with regard to the perceived desirability and perceived feasibility of self-employment. The Company Programme (CP) is the largest mini-company scheme in European secondary school. Design/methodology/approach: The data derived…

Afrique : ressources minières, environnement et gouvernance ...

International Development Research Centre (IDRC) Digital Library (Canada)

25 janv. 2011 ... ils regorgent de richesses inouïes », assure Bonnie Campbell, directrice du Groupe de recherche sur les activités minières en Afrique (GRAMA) et titulaire de la Chaire C.-A. Poissant de recherche sur la gouvernance et l'aide au développement, faisant référence aux ressources minières et pétrolières dont ...

MiniDLNA_tweaker : Aplicació per configurar i previsualitzar el servidor MiniDLNA per a GNU/Linux

OpenAIRE

Martínez Lloveras, Jordi

2013-01-01

L'aplicació MiniDLNA per a GNU/Linux és un servidor lleuger que compleix els estàndards DLNA/UPnP configurable a través d'un simple arxiu de text, això la fa ideal per al propòsit d'implantació d'un servidor que ofereixi els continguts a tots els dispositius que compleixin els estàndards esmentats. La aplicación MiniDLNA para GNU/Linux es un servidor ligero que cumple los estándares DLNA/UPnP configurable a través de un simple archivo de texto, esto la hace ideal para el propósito de impla...

Positron creation in superheavy quasi-molecules

International Nuclear Information System (INIS)

Mueller, B.

1976-01-01

The review of positron creation in superheavy quasi-molecules includes spontaneous positron emission from superheavy atoms, supercritical quasi-molecules, background effects, and some implications of the new ground state. 66 references

Converting lignin to aromatics: step by step

NARCIS (Netherlands)

Strassberger, Z.I.

2014-01-01

Lignin, the glue that holds trees together, is the most abundant natural resource of aromatics. In that respect, it is a far more advanced resource than crude oil. This is because lignin already contains the aromatic functional groups. Thus, catalytic conversion of lignin to high-value aromatics is

Quantum coherent π-electron rotations in a non-planar chiral molecule induced by using a linearly polarized UV laser pulse

Science.gov (United States)

Mineo, Hirobumi; Fujimura, Yuichi

2015-06-01

We propose an ultrafast quantum switching method of π-electron rotations, which are switched among four rotational patterns in a nonplanar chiral aromatic molecule (P)-2,2’- biphenol and perform the sequential switching among four rotational patterns which are performed by the overlapped pump-dump laser pulses. Coherent π-electron dynamics are generated by applying the linearly polarized UV pulse laser to create a pair of coherent quasidegenerated excited states. We also plot the time-dependent π-electron ring current, and discussed ring current transfer between two aromatic rings.

Agreement between clinical and MINI diagnoses in outpatients with mood and anxiety disorders

NARCIS (Netherlands)

Verhoeven, F. E. A.; Swaab, L. S. M. A.; Carlier, I. V. E.; van Hemert, A. M.; Zitman, F. G.; Ruhé, H. G.; Schoevers, R. A.; Giltay, E. J.

2017-01-01

Background: Standardized Diagnostic Interviews (SDIs) such as the Mini International Neuropsychiatric Interview (MINI) are widely used to systematically screen for psychiatric disorders in research. To support generalizability of results to clinical practice, we assessed agreement between the MINI

Do dual-thread orthodontic mini-implants improve bone/tissue mechanical retention?

Science.gov (United States)

Lin, Yang-Sung; Chang, Yau-Zen; Yu, Jian-Hong; Lin, Chun-Li

2014-12-01

The aim of this study was to understand whether the pitch relationship between micro and macro thread designs with a parametrical relationship in a dual-thread mini-implant can improve primary stability. Three types of mini-implants consisting of single-thread (ST) (0.75 mm pitch in whole length), dual-thread A (DTA) with double-start 0.375 mm pitch, and dual-thread B (DTB) with single-start 0.2 mm pitch in upper 2-mm micro thread region for performing insertion and pull-out testing. Histomorphometric analysis was performed in these specimens in evaluating peri-implant bone defects using a non-contact vision measuring system. The maximum inserted torque (Tmax) in type DTA was found to be the smallest significantly, but corresponding values found no significant difference between ST and DTB. The largest pull-out strength (Fmax) in the DTA mini-implant was found significantly greater than that for the ST mini-implant regardless of implant insertion orientation. Mini-implant engaged the cortical bone well as observed in ST and DTA types. Dual-thread mini-implant with correct micro thread pitch (parametrical relationship with macro thread pitch) in the cortical bone region can improve primary stability and enhanced mechanical retention.

Upgrading Lignocellulosic Biomasses: Hydrogenolysis of Platform Derived Molecules Promoted by Heterogeneous Pd-Fe Catalysts

Directory of Open Access Journals (Sweden)

Claudia Espro

2017-03-01

Full Text Available This review provides an overview of heterogeneous bimetallic Pd-Fe catalysts in the C–C and C–O cleavage of platform molecules such as C2–C6 polyols, furfural, phenol derivatives and aromatic ethers that are all easily obtainable from renewable cellulose, hemicellulose and lignin (the major components of lignocellulosic biomasses. The interaction between palladium and iron affords bimetallic Pd-Fe sites (ensemble or alloy that were found to be very active in several sustainable reactions including hydrogenolysis, catalytic transfer hydrogenolysis (CTH and aqueous phase reforming (APR that will be highlighted. This contribution concentrates also on the different synthetic strategies (incipient wetness impregnation, deposition-precipitaion, co-precipitaion adopted for the preparation of heterogeneous Pd-Fe systems as well as on the main characterization techniques used (XRD, TEM, H2-TPR, XPS and EXAFS in order to elucidate the key factors that influence the unique catalytic performances observed.

Mini-gastric bypass to control morbid obesity and diabetes mellitus: What radiologists need to know

Energy Technology Data Exchange (ETDEWEB)

Park, Hyun Jeong [Dept. of Radiology, Chung-Ang University Hospital, Seoul (Korea, Republic of); Hong, Seong Sook; Hwang, Ji Young; Hur, Kyung Yul [Soonchunhyang University Seoul Hospital, Seoul (Korea, Republic of)

2015-04-15

Laparoscopic mini-gastric bypass surgery is a safe and simple surgical intervention for treating morbid obesity and diabetes mellitus and is now being performed more frequently. Radiologists must be critical in their postoperative evaluation of these patients. In this pictorial review, we explain and illustrate the surgical technique, normal postoperative anatomy, and associated complications as seen on imaging examinations, including fluoroscopy and computed tomography.

The Galactic Centre Mini-Spiral with CARMA

Science.gov (United States)

Kunneriath, D.; Eckart, A.; Vogel, S. N.; Teuben, P.; Muzic, K.; Schodel. R.; Garcia-Marin, M.; Moultaka, J.; Staguhn, J.; Straubmeier, C.;

Photovoltaic energy mini-generation: Future perspectives for Portugal

International Nuclear Information System (INIS)

Carvalho, Duarte; Wemans, Joao; Lima, Joao; Malico, Isabel

2011-01-01

This paper evaluates the benefits of developing the mini-generation PV market in Portugal. It presents the legal framework and current status of the Portuguese PV electricity sector, and compares the country to other European nations: France, Germany, Greece, Italy, Spain and the United Kingdom. A model that combines PVGIS with a self-developed financial tool is used to assess the feasibility of a 150 kW mini-generation system using five different technologies: fixed mount, single-axis tracking, double-axis tracking, low concentration and medium concentration (MCPV). The profitability of the mini-generation systems in the seven countries studied is calculated and compared. According to this analysis, MCPV and, of the conventional technologies, the single-axis tracking systems are the most profitable technologies. Despite the attractiveness of the current Portuguese feed-in tariffs and of the abundant solar resource, investors are discouraged and the country's PV market is far from mature. Specific mini-generation regulations should focus on a fast and transparent licensing procedure and should promote the access to financing. This would attract new investments, which would result in the growth of the PV electricity produced, and would help Portugal to meet its European Union Renewable Energy targets. - Highlights: → This work promotes the development of a mini-generation PV market in Portugal. → The Portuguese current status and legal framework is compared to other EU countries. → The profitability of 5 different PV technologies is compared for 7 European countries. → The Portuguese growth potential for PV energy is still big. → Portugal, due to its radiation levels, presents excellent investment opportunities.