Electronic structure of copper phthalocyanine : An experimental and theoretical study of occupied and unoccupied levels

NARCIS (Netherlands)

Evangelista, Fabrizio; Carravetta, Vincenzo; Stefani, Giovanni; Jansik, Branislav; Alagia, Michele; Stranges, Stefano; Ruocco, Alessandro

2007-01-01

An experimental and theoretical study of the electronic structure of copper phthalocyanine (CuPc) molecule is presented. We performed x-ray photoemission spectroscopy (XPS) and photoabsorption [x-ray absorption near-edge structure (XANES)] gas phase experiments and we compared the results with

Binary molecular layers of C-60 and copper phthalocyanine on Au(111) : Self-organized nanostructuring

NARCIS (Netherlands)

Stöhr, Meike; Wagner, Thorsten; Gabriel, Markus; Weyers, Bastian; Möller, Rolf

The binary molecular system of C-60 and copper phthalocyanine(CuPc) molecules has been investigated by scanning tunneling microscopy (STM) at room temperature and at 50 K. As substrate Au(111) was chosen. When C-60 and CuPc molecules are sequentially deposited, it is found that well-ordered domains

Ab initio electronic structure and correlations in pristine and potassium-doped molecular crystals of copper phthalocyanine

NARCIS (Netherlands)

Giovannetti, G.; Brocks, G.; van den Brink, J.

2008-01-01

We investigate the effect that potassium intercalation has on the electronic structure of copper phthalocyanine (CuPc) molecular crystals by means of ab initio density functional calculations. Pristine CuPc (in its alpha and beta structures) is found to be an insulator containing local magnetic

Hindered rotation of a copper phthalocyanine molecule on C60 : Experiments and molecular mechanics calculations

NARCIS (Netherlands)

Fendrich, M.; Wagner, Th.; Stöhr, M.; Möller, R.

2006-01-01

If copper phthalocyanine (CuPc) molecules are deposited on a Au(111) surface covered with a monolayer of C60, the molecules are found to adsorb individually onto the close-packed layer of C60. As the adsorption site of the CuPc is not symmetric with respect to the underlying C60 layer, the CuPc

Nucleation and growth of copper phthalocyanine aggregates deposited from solution on planar surfaces

Energy Technology Data Exchange (ETDEWEB)

Ghani, Fatemeh [Department of Theory & Bio-Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1 Golm, 14476 Potsdam (Germany); Gojzewski, Hubert, E-mail: hubert.gojzewski@put.poznan.pl [Department of Theory & Bio-Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1 Golm, 14476 Potsdam (Germany); Institute of Physics, Poznan University of Technology, Piotrowo 3, 60-965 Poznan (Poland); Riegler, Hans [Department of Theory & Bio-Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1 Golm, 14476 Potsdam (Germany)

2015-10-01

Graphical abstract: - Highlights: • Copper phthalocyanine deposited on planar surfaces by 3 solution process methods. • Aggregate morphology examined for coverage extending over 3 orders of magnitude. • Morphologies vary from small individual domains to mesh-like multilayers. • Nucleation and growth model explains the observed deposit morphologies. - Abstract: Copper phthalocyanine (CuPc) dissolved in trifluoroacetic acid (TFA) is deposited on solid SiO{sub 2} surfaces by solvent evaporation. The deposited CuPc aggregates are investigated by atomic force microscopy (AFM). The CuPc deposits were prepared by spin casting, dip coating, and spray deposition. Depending on the amount of deposited CuPc the aggregate morphology ranges from small individual domains to mesh-like multilayers. Each domain/layer consists of many parallel stacks of CuPc molecules with the square, plate-like molecules piled face-wise within each stack. The parallel stacks are attached sideways (i.e., edgewise attachment molecularly) to the substrate forming “nanoribbons” with uniform thickness of about 1 nm and varying width. The thickness reflects the length of a molecular edge, the width the number of stacks. A nucleation and growth model is presented that explains the observed aggregate and multilayer morphologies as result of the combination of nucleation, transport processes and a consequence of the anisotropic intermolecular interactions due to the shape of the CuPc molecule.

Corrections to the density-functional theory electronic spectrum: Copper phthalocyanine

DEFF Research Database (Denmark)

Vazquez, Hector; Jelinek, P.; Brandbyge, Mads

2009-01-01

A method for improving the electronic spectrum of standard Density-Functional Theory (DFT) calculations (i.e., LDA or GGA approximations) is presented, and its application is discussed for the case of the copper phthalocyanine (CuPc) molecule. The method is based on a treatment of exchange...... and correlation in a many-body Hamiltonian, and it leads to easy-to-evaluate corrections to the DFT eigenvalues. Self-interaction is largely corrected, so that the modified energy levels do not suffer from spurious crossings, as often encountered for CuPc in DFT, and they remedy the standard underestimation...... or semiempirical functionals for molecular levels, it can be easily applied to any local-orbital DFT approach, improving on several important limitations of standard DFT methods....

Sensing of volatile organic compounds by copper phthalocyanine thin films

Science.gov (United States)

Ridhi, R.; Saini, G. S. S.; Tripathi, S. K.

2017-02-01

Thin films of copper phthalocyanine have been deposited by thermal evaporation technique. We have subsequently exposed these films to the vapours of methanol, ethanol and propanol. Optical absorption, infrared spectra and electrical conductivities of these films before and after exposure to chemical vapours have been recorded in order to study their sensing mechanisms towards organic vapours. These films exhibit maximum sensing response to methanol while low sensitivities of the films towards ethanol and propanol have been observed. The changes in sensitivities have been correlated with presence of carbon groups in the chemical vapours. The effect of different types of electrodes on response-recovery times of the thin film with organic vapours has been studied and compared. The electrodes gap distance affects the sensitivity as well as response-recovery time values of the thin films.

Energy level alignment at the methylammonium lead iodide/copper phthalocyanine interface

Directory of Open Access Journals (Sweden)

Shi Chen

2014-08-01

Full Text Available The energy level alignment at the CH3NH3PbI3/copper phthalocyanine (CuPc interface is investigated by X-ray photoelectron spectroscopy (XPS and ultraviolet photoelectron spectroscopy (UPS. XPS reveal a 0.3 eV downward band bending in the CuPc film. UPS validate this finding and further reveal negligible interfacial dipole formation – verifying the viability of vacuum level alignment. The highest occupied molecular orbital of CuPc is found to be closer to the Fermi level than the valance band maximum of CH3NH3PbI3, facilitating hole transfer from CH3NH3PbI3 to CuPc. However, subsequent hole extraction from CuPc may be impeded by the downward band bending in the CuPc layer.

Pinning of fullerene lowest unoccupied molecular orbital edge at the interface with standing up copper phthalocyanine

International Nuclear Information System (INIS)

Wang, Chenggong; Irfan, Irfan; Turinske, Alexander J.; Gao, Yongli

2012-01-01

The electronic structure evolution of interfaces of fullerene (C 60 ) with copper phthalocyanine (CuPc) on highly oriented pyrolitic graphite (HOPG) and on native silicon oxide has been investigated with ultra-violet photoemission spectroscopy and inverse photoemission spectroscopy. The lowest unoccupied molecular orbital edge of C 60 was found to be pinned at the interface with CuPc on SiO 2 . A substantial difference in the electron affinity of CuPc on the two substrates was observed as the orientation of CuPc is lying flat on HOPG and standing up on SiO 2 . The ionization potential and electron affinity of C 60 were not affected by the orientation of CuPc due to the spherical symmetry of C 60 molecules. We observed band bending in C 60 on the standing-up orientation of CuPc molecules, while the energy levels of C 60 on the flat lying orientation of CuPc molecules were observed to be flat. - Highlights: ► Orientation of copper phthalocyanine (CuPc) on ordered graphite and silicon oxide. ► Pinning of lowest unoccupied molecular orbital edge of C60 to the Fermi level on CuPc. ► No C60 pinning or band bending was observed on flat laying CuPc. ► Results are useful for organic photovoltaic and organic light emitting diode research.

Fabrication and characterization of tetracyanoquinodimethane/phthalocyanine solar cells

International Nuclear Information System (INIS)

Suzuki, Atsushi; Ohtsuki, Takahiro; Oku, Takeo; Akiyama, Tsuyoshi

2012-01-01

Highlights: ► Heterojunction solar cells of tetracyanoquinodimethane (TCNQ)/copper phthalocyanine (CuPc) and zinc phthalocyanine (ZnPc) were fabricated and characterized. ► The light-induced charge separation with charge transfer was investigated by light-induced current density and optical absorption.. ► In both solar cells of TCNQ/CuPc and TCNQ/ZnPc, the TCNQ thin film worked for strong electron-accepting layer. ► These behaviors would be originated in charge transfer of excited electron from CuPc and ZnPc to TCNQ. ► The photovoltaic mechanism was discussed by the experimental results. - Abstract: Fabrication and characterization of heterojunction solar cells of tetracyanoquinodimethane (TCNQ)/copper phthalocyanine (CuPc) and zinc phthalocyanine (ZnPc) were carried out. The light-induced charge separation with charge transfer was investigated by light-induced current density and optical absorption. In both cases of the TCNQ/CuPc and TCNQ/ZnPc solar cells, the TCNQ thin film worked for strong electron-accepting layer as n-type semiconductor. These behaviors would be originated in charge transfer of excited electron from CuPc and ZnPc to TCNQ. The photovoltaic mechanism was discussed on the basis of the experimental results.

Synchrotron-based measurements of the electronic structure of the organic semiconductor copper phthalocyanine

International Nuclear Information System (INIS)

Downes, J.E.

2004-01-01

Full text: Copper phthalocyanine (CuPc) is a prototypical molecular organic semiconductor that is currently used in the construction of many organic electronic devices such as organic light emitting diodes (OLEDs). Although the material is currently being used, and despite many experimental and theoretical studies, it's detailed electronic structure is still not completely understood. This is likely due to two key factors. Firstly, the interaction of the Cu 3d and phthalocyanine ligand 2p electrons leads to the formation of a complex arrangement of localized and delocalized states near the Fermi level. Secondly, thin films of the material are subject to damage by the photon beam used to make measurements of their electronic structure. Using the synchrotron-based techniques of soft x-ray emission spectroscopy (XES) and x-ray photoemission spectroscopy (XPS), we have measured the detailed electronic structure of in-situ grown thin film samples of CuPc. Beam damage was minimized by continuous translation of the sample during data acquisition. The results obtained differ significantly from previous XES and ultraviolet photoemission measurements, but are in excellent agreement with recent density functional calculations. The reasons for these discrepancies will be explained, and their implications for future measurements on similar materials will be explored

Covalentely Attached Multilayer Films Comprising Phthalocyanine and Their Photoelectron Conversion Properties

Institute of Scientific and Technical Information of China (English)

ZANG Mao-feng; YAO Qiao-hong; YANG Zhao-hui; HUANG Chun-hui; CAO Wei-xiao

2004-01-01

The photosensitive multilayer films from sulfonated metal-free, sulfonated copper-, and sulfonated nickel-phthalocyanines were fabricated with diazoresin layer by layer on a substrate via electrostatic interaction by the self-assembly technique. Under UV irradiation, the linkage nature between the layers of the film is converted from the electrostatic bonding to covalent bonding. The covalently attached multilayer films are very stable towards polar solvents and salt aqueous solutions. The photovoltaic properties of the covalently attached film can be determined by means of a traditional three-electrode photoelectrochemical cell in aqueous solutions with KCl as the supporting electrolyte. The photocurrent determination has shown that the sulfonated copper-containing phthalocyanine films possess a higher photocurrent value than sulfonated metalfree and sulfonated nickel-containing phthalocyanine films.

Hole Mobility of Molecular β-Copper Phthalocyanine Crystal

International Nuclear Information System (INIS)

Pengmanayol, S.; Osotchan, T.; Suewattana, M.; Ingadapa, N.; Girdpun, J.

2011-01-01

A Monte Carlo approach is used to estimate hole mobilities in molecular β-copper phthalocyanine (CuPc) crystal for different applied electric field directions. Due to the crystal symmetry, the twelve neighboring molecules in the three-dimensional crystal are selected in the hopping rate calculation. Density functional theory is employed to derive the molecular interaction between the central and neighboring molecules for various applied electric fields. The derived molecular hopping rate is applied to 80 × 80 × 80 lattice sites under periodic boundary conditions. In order to achieve accurate statistics, each calculation includes 6561 particles with more than 10000 hopping steps under an applied electric field of 0.5–3.5 MV/cm. The results indicate that the molecular hopping strongly depends on the molecular orientation and neighboring sites related to the applied electric field direction. The estimated carrier mobility can be described by the percentage occupation in each neighboring site and the obtained hole mobility value is in the same range of the measured values of single crystal CuPc. The calculated mobility for applied electric field along the c crystal axis exhibits the highest values while the mobility along the b axis has the smallest value. (condensed matter: structure, mechanical and thermal properties)

Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)

Energy Technology Data Exchange (ETDEWEB)

Xiao, Teng [Iowa State Univ., Ames, IA (United States)

2012-01-01

Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3- hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A

Nonvolatile organic write-once-read-many-times memory devices based on hexadecafluoro-copper-phthalocyanine

Science.gov (United States)

Wang, Lidan; Su, Zisheng; Wang, Cheng

2012-05-01

Nonvolatile organic write-once-read-many-times memory device was demonstrated based on hexadecafluoro-copper-phthalocyanine (F16CuPc) single layer sandwiched between indium tin oxide (ITO) anode and Al cathode. The as fabricated device remains in ON state and it can be tuned to OFF state by applying a reverse bias. The ON/OFF current ratio of the device can reach up to 2.3 × 103. Simultaneously, the device shows long-term storage stability and long retention time in air. The ON/OFF transition is attributed to the formation and destruction of the interfacial dipole layer in the ITO/F16CuPc interface, and such a mechanism is different from previously reported ones.

Controlling molecular condensation/diffusion of copper phthalocyanine by local electric field induced with scanning tunneling microscope tip

Science.gov (United States)

Nagaoka, Katsumi; Yaginuma, Shin; Nakayama, Tomonobu

2018-02-01

We have discovered the condensation/diffusion phenomena of copper phthalocyanine (CuPc) molecules controlled with a pulsed electric field induced by the scanning tunneling microscope tip. This behavior is not explained by the conventional induced dipole model. In order to understand the mechanism, we have measured the electronic structure of the molecule by tunneling spectroscopy and also performed theoretical calculations on molecular orbitals. These data clearly indicate that the molecule is positively charged owing to charge transfer to the substrate, and that hydrogen bonding exists between CuPc molecules, which makes the molecular island stable.

High-mobility solution-processed copper phthalocyanine-based organic field-effect transistors

Directory of Open Access Journals (Sweden)

Nandu B Chaure, Andrew N Cammidge, Isabelle Chambrier, Michael J Cook, Markys G Cain, Craig E Murphy, Chandana Pal and Asim K Ray

2011-01-01

Full Text Available Solution-processed films of 1,4,8,11,15,18,22,25-octakis(hexyl copper phthalocyanine (CuPc6 were utilized as an active semiconducting layer in the fabrication of organic field-effect transistors (OFETs in the bottom-gate configurations using chemical vapour deposited silicon dioxide (SiO2 as gate dielectrics. The surface treatment of the gate dielectric with a self-assembled monolayer of octadecyltrichlorosilane (OTS resulted in values of 4×10−2 cm2 V−1 s−1 and 106 for saturation mobility and on/off current ratio, respectively. This improvement was accompanied by a shift in the threshold voltage from 3 V for untreated devices to -2 V for OTS treated devices. The trap density at the interface between the gate dielectric and semiconductor decreased by about one order of magnitude after the surface treatment. The transistors with the OTS treated gate dielectrics were more stable over a 30-day period in air than untreated ones.

Influence of Exchange-Correlation Functional in the Calculations of Vertical Excitation Energies of Halogenated Copper Phthalocyanines using Time-Dependent Density Functional Theory (TD-DFT)

International Nuclear Information System (INIS)

Lee, Sang Uck

2013-01-01

The accurate prediction of vertical excitation energies is very important for the development of new materials in the dye and pigment industry. A time-dependent density functional theory (TD-DFT) approach coupled with 22 different exchange-correlation functionals was used for the prediction of vertical excitation energies in the halogenated copper phthalocyanine molecules in order to find the most appropriate functional and to determine the accuracy of the prediction of the absorption wavelength and observed spectral shifts. Among the tested functional, B3LYP functional provides much more accurate vertical excitation energies and UV-vis spectra. Our results clearly provide a benchmark calibration of the TD-DFT method for phthalocyanine based dyes and pigments used in industry

Effect of annealing on bulk heterojunction organic solar cells based on copper phthalocyanine and perylene derivative

KAUST Repository

Kim, Inho

2012-02-01

We investigated the effects of annealing on device performances of bulk heterojunction organic solar cells based on copper phthalocyanine (CuPc) and N,N′-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C6). Blended films of CuPc and PTCDI-C6 with annealing at elevated temperature were characterized by measuring optical absorption, photoluminescence, and X-ray diffraction. Enhanced molecular ordering and increments in domain sizes of donor and acceptor for the blended films were observed, and their influences on device performances were discussed. Annealing led to substantial improvements in photocurrent owing to enhanced molecular ordering and formation of percolation pathways. © 2011 Elsevier B.V. All rights reserved.

Effect of oxide insertion layer on resistance switching properties of copper phthalocyanine

Science.gov (United States)

Joshi, Nikhil G.; Pandya, Nirav C.; Joshi, U. S.

2013-02-01

Organic memory device showing resistance switching properties is a next-generation of the electrical memory unit. We have investigated the bistable resistance switching in current-voltage (I-V) characteristics of organic diode based on copper phthalocyanine (CuPc) film sandwiched between aluminum (Al) electrodes. Pronounced hysteresis in the I-V curves revealed a resistance switching with on-off ratio of the order of 85%. In order to control the charge injection in the CuPc, nanoscale indium oxide buffer layer was inserted to form Al/CuPc/In2O3/Al device. Analysis of I-V measurements revealed space charge limited switching conduction at the Al/CuPc interface. The traps in the organic layer and charge blocking by oxide insertion layer have been used to explain the absence of resistance switching in the oxide buffer layered memory device cell. Present study offer potential applications for CuPc organic semiconductor in low power non volatile resistive switching memory and logic circuits.

Spectroscopic investigation of sulfonate phthalocyanine to probe enzyme reactions for heavy metals detection

Energy Technology Data Exchange (ETDEWEB)

Chaure, Shweta; Paul, Deepen; Vadagma, Pankaj [School of Engineering and Material Science, Queen Mary, University of London, London E1 4NS (United Kingdom); Ray, Asim K., E-mail: a.k.ray@qmul.ac.uk [School of Engineering and Material Science, Queen Mary, University of London, London E1 4NS (United Kingdom)

2010-01-15

Optical absorption and Raman spectra of the sulfonated copper phthalocyanine (CuTsPc) layer were exploited for detection of cadmium (Cd) contaminants in water. Acetylcholine esterase was immobilized by freely suspending them in calcium alginate microbeads and this gel was then spincoated on the drop cast sulfonated copper phthalocyanine film on a glass substrate to form a bilayer. The inhibition of catalytic reaction between acetylcholine chloride and enzyme due to Cd contaminants was monitored by recording changes in spectra of drop cast CuTsPc as an indicator. The detection limit of cadmium content in water was found to be 1 ppm.

Spectroscopic investigation of sulfonate phthalocyanine to probe enzyme reactions for heavy metals detection

International Nuclear Information System (INIS)

Chaure, Shweta; Paul, Deepen; Vadagma, Pankaj; Ray, Asim K.

2010-01-01

Optical absorption and Raman spectra of the sulfonated copper phthalocyanine (CuTsPc) layer were exploited for detection of cadmium (Cd) contaminants in water. Acetylcholine esterase was immobilized by freely suspending them in calcium alginate microbeads and this gel was then spincoated on the drop cast sulfonated copper phthalocyanine film on a glass substrate to form a bilayer. The inhibition of catalytic reaction between acetylcholine chloride and enzyme due to Cd contaminants was monitored by recording changes in spectra of drop cast CuTsPc as an indicator. The detection limit of cadmium content in water was found to be 1 ppm.

Revisiting the adsorption of copper-phthalocyanine on Au(111) including van der Waals corrections

International Nuclear Information System (INIS)

Lüder, Johann; Eriksson, Olle; Sanyal, Biplab; Brena, Barbara

2014-01-01

We have studied the adsorption of copper-phthalocyanine on Au(111) by means of van der Waals corrected density functional theory using the Tkatchenko-Scheffler method. We have compared the element and site resolved adsorption distances to recent experimental normal-incident X-ray standing wave measurements. The measured adsorption distances could be reproduced within a deviation of 1% for the Cu atom, 1% for the C atoms, and 2% for the N atoms. The molecule was found to have a magnetic moment of 1 μ B distributed over the Cu and the N atoms of the pyrrole ring. Simulated scanning tunnel microscopy images based on the total and on the spin-resolved differential charge densities are provided for bias voltages of −1.45 and 1.45 eV

Spontaneous Adsorption of a Co-Phthalocyanine Ionic Derivative on HOPG. An In Situ EPR Study

Czech Academy of Sciences Publication Activity Database

Tarábek, Ján; Klusáčková, Monika; Janda, Pavel; Tarábková, Hana; Rulíšek, Lubomír; Plšek, Jan

2014-01-01

Roč. 118, č. 8 (2014), s. 4198-4206 ISSN 1932-7447 R&D Projects: GA ČR(CZ) GA14-31419S Institutional support: RVO:61388963 ; RVO:61388955 Keywords : scanning tunneling microscopy * electron paramagnetic resonance * metal phthalocyanine s * copper phthalocyanine Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.772, year: 2014

Back to the future: An online OSCE Management Information System for nursing OSCEs.

Science.gov (United States)

Meskell, Pauline; Burke, Eimear; Kropmans, Thomas J B; Byrne, Evelyn; Setyonugroho, Winny; Kennedy, Kieran M

2015-11-01

The Objective Structured Clinical Examination (OSCE) is an established tool in the repertoire of clinical assessment methods in nurse education. The use of OSCEs facilitates the assessment of psychomotor skills as well as knowledge and attitudes. Identified benefits of OSCE assessment include development of students' confidence in their clinical skills and preparation for clinical practice. However, a number of challenges exist with the traditional paper methodology, including documentation errors and inadequate student feedback. To explore electronic OSCE delivery and evaluate the benefits of using an electronic OSCE management system. To explore assessors' perceptions of and attitudes to the computer based package. This study was conducted using electronic software in the management of a four station OSCE assessment with a cohort of first year undergraduate nursing students delivered over two consecutive years (n=203) in one higher education institution in Ireland. A quantitative descriptive survey methodology was used to obtain the views of the assessors on the process and outcome of using the software. OSCE documentation was converted to electronic format. Assessors were trained in the use of the OSCE management software package and laptops were procured to facilitate electronic management of the OSCE assessment. Following the OSCE assessment, assessors were invited to evaluate the experience. Electronic software facilitated the storage and analysis of overall group and individual results thereby offering considerable time savings. Submission of electronic forms was allowed only when fully completed thus removing the potential for missing data. The feedback facility allowed the student to receive timely evaluation on their performance and to benchmark their performance against the class. Assessors' satisfaction with the software was high. Analysis of assessment results can highlight issues around internal consistency being moderate and examiners variability

Marine sponge skeleton photosensitized by copper phthalocyanine: A catalyst for Rhodamine B degradation

Directory of Open Access Journals (Sweden)

Norman Małgorzata

2016-01-01

Full Text Available We present a combined approach to photo-assisted degradation processes, in which a catalyst, H2O2 and UV irradiation are used together to enhance the oxidation of Rhodamine B (RB. The heterogeneous photocatalyst was made by the process of adsorption of copper phthalocyanine tetrasulfonic acid (CuPC onto purified spongin-based Hippospongia communis marine sponge skeleton (HcS. The product obtained, CuPC-HcS, was investigated by a variety of spectroscopic (carbon-13 nuclear magnetic resonance 13C NMR, Fourier transform infrared spectroscopy FTIR, energy-dispersive X-ray spectroscopy EDS and microscopic techniques (scanning electron microscopy SEM, fluorescent and optical microscopy, as well as thermal analysis. The study confirms the stable combination of the adsorbent and adsorbate. For a 10 mg/L RB solution, the percentage degradation reached 95% using CuPC-HcS as a heterocatalyst. The mechanism of RB removal involves adsorption and photodegradation simultaneously.

Change spectroscopic studies and optimization electrical properties of PVP/PEO doped copper phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Ragab, H.M., E-mail: yara20092009@yahoo.com [Department of Physics, Faculty of Science, Al-Azhar University, Girls Branch, Cairo 11754 (Egypt); Basic Science Department, Faculty of Preparatory Year, Hail University (Saudi Arabia); Ahmad, F.; Radwan, Sh.N. [Department of Physics, Faculty of Science, Al-Azhar University, Girls Branch, Cairo 11754 (Egypt)

2016-12-01

Composite films of polyvinyl pyrrolidone and Polyethylene oxide (PVP/PEO) blend doped with 1, 4 and 12 wt% of copper Phthalocyanines (CuPc) were prepared by casting method. The samples were studied using different techniques. The X-ray (XRD) revealed average crystallite size and X-ray intensity decrease at 1 CuPc %; this implies to an increase on the degree of amorphousity, then increase at CuPc >1%. The change in both the intensity and position of some absorption peaks of the blend with CuPc content were observed in Fourier transform infrared (FTIR) spectroscopy suggest the complexation of polymer blend. The UV–Vis spectroscopy revealed that the optical band gap decreases as well as band tail width increases with increasing CuPc concentration. It may be reflect the role of CuPc in modifying the electronic structure of the polymeric matrix. The charge carrier concentration is responsible for conductivity improvement in electrolytes rather than the mobility.

The photophysical and photochemical properties of new unmetallated and metallated phthalocyanines bearing four 5-chloroquinolin-8-yloxy substituents on peripheral sites

Energy Technology Data Exchange (ETDEWEB)

Nas, Asiye; Demirbaş, Ümit [Department of Chemistry, Karadeniz Technical University, 61080 Trabzon (Turkey); Pişkin, Mehmet [Marmara University, Faculty of Art and Science, Department of Chemistry, 34722 Kadıkoy-Istanbul (Turkey); Durmuş, Mahmut [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze, 41400 Kocaeli (Turkey); Kantekin, Halit, E-mail: halit@ktu.edu.tr [Department of Chemistry, Karadeniz Technical University, 61080 Trabzon (Turkey)

2014-01-15

The synthesis and characterization of novel peripherally tetrakis-(5-chloroquinolin-8-yloxy) substituted metal-free (4), zinc(II) (5), lead(II) (6), cobalt(II) (7), copper(II) (8) and nickel(II) (9) phthalocyanines are described for the first time in this study. The spectroscopic, photophysical (fluorescence quantum yields and lifetimes) and photochemical properties (singlet oxygen production and photodegradation under light irradiation) of metal-free (4), zinc(II) (5) and lead(II) (6) phthalocyanines are investigated in N,N-dimetilformamid (DMF). The newly synthesized cobalt(II) (7), copper(II) (8) and nickel(II) (9) phthalocyanine compounds were not evaluated for this purpose due to open shell nature of these central metals in the phthalocyanine cavity. The influence of various the nature of the central metal ion (zinc, lead or without metal) on these properties has also been investigated and compared. -- Highlights: • The synthesis and characterization of novel peripherally tetrakis-(5-chloroquinolin-8-yloxy) substituted metal-free (4), zinc(II) (5), lead(II) (6), cobalt(II) (7), copper(II) (8) and nickel(II) (9) phthalocyanines. • The spectroscopic, photophysical (fluorescence quantum yields and lifetimes) and photochemical properties of metal-free (4), zinc(II) (5) and lead(II) (6)phthalocyanines in N, N-dimetilformamid (DMF). • The influence of various the nature of the central metal ion (zinc, lead or without metal) on these properties.

Effect of pentacene/Ag anode buffer and UV-ozone treatment on durability of small-molecule organic solar cells

International Nuclear Information System (INIS)

Inagaki, S; Sueoka, S; Harafuji, K

2017-01-01

Three surface modifications of indium tin oxide (ITO) are experimentally investigated to improve the performance of small-molecule organic solar cells (OSCs) with an ITO/anode buffer layer (ABL)/copper phthalocyanine (CuPc)/fullerene/bathocuproine/Ag structure. An ultrathin Ag ABL and ultraviolet (UV)-ozone treatment of ITO independently improve the durability of OSCs against illumination stress. The thin pentacene ABL provides good ohmic contact between the ITO and the CuPc layer, thereby producing a large short-circuit current. The combined use of the abovementioned three modifications collectively achieves both better initial performance and durability against illumination stress. (paper)

Effect of pentacene/Ag anode buffer and UV-ozone treatment on durability of small-molecule organic solar cells

Science.gov (United States)

Inagaki, S.; Sueoka, S.; Harafuji, K.

2017-06-01

Three surface modifications of indium tin oxide (ITO) are experimentally investigated to improve the performance of small-molecule organic solar cells (OSCs) with an ITO/anode buffer layer (ABL)/copper phthalocyanine (CuPc)/fullerene/bathocuproine/Ag structure. An ultrathin Ag ABL and ultraviolet (UV)-ozone treatment of ITO independently improve the durability of OSCs against illumination stress. The thin pentacene ABL provides good ohmic contact between the ITO and the CuPc layer, thereby producing a large short-circuit current. The combined use of the abovementioned three modifications collectively achieves both better initial performance and durability against illumination stress.

Controlling the Orbital Sequence in Individual Cu-Phthalocyanine Molecules

NARCIS (Netherlands)

Uhlmann, C.; Swart, I.; Repp, J.

2013-01-01

We report on the controlled change of the energetic ordering of molecular orbitals. Negatively charged copper(II)phthalocyanine on NaCl/Cu(100) undergoes a Jahn–Teller distortion that lifts the degeneracy of two frontier orbitals. The energetic order of the levels can be controlled by Au and Ag

Is OSCE successful in pediatrics?

Directory of Open Access Journals (Sweden)

M Imani

2009-02-01

Full Text Available Background: The Faculty of Medical Sciences, University of Zahedan implemented the Objective Structured Clinical Examination (OSCE in the final Examination during the 2003–2004 academic year. Simultaneously, the pediatric department initiated faculty and student training, and instituted the OSCE as an assessment instrument during the pediatric clerkship in year 5. The study set out to explore student acceptance of the OSCE as part of an evaluation of the Pediatric clerkship.Purpose: This study implemented to evaluate a new method of assessment in medical education in pediatrics.Methods: A self-administered questionnaire was completed by successive groups of students immediately after the OSCE at the end of each clerkship rotation. Main outcome measures were student perception of examination attributes, which included the quality of instructions and organization, the quality of performance, authenticity and transparency of the process, and usefulness of the OSCE as an assessment instrument compared to other methods.Results: There was overwhelming acceptance of the OSCE in Pediatric with respect to the comprehensiveness (90%, transparency (87%, fairness (57% and authenticity of the required tasks (58–78%. However, students felt that it was a strong anxiety-producing experience. And concerns were expressed regarding the ambiguity of some questions and inadequacy of time for expected tasks.Conclusion: Student feedback was invaluable in influencing faculty teaching, curriculum direction and appreciation of student opinion. Further psychometric evaluation will strengthen the development of the OSCE.Key words: OSCE, COMPETENCE ASSESSMENT

Thermal Annealing Effect on Poly(3-hexylthiophene: Fullerene:Copper-Phthalocyanine Ternary Photoactive Layer

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H. Derouiche

2013-01-01

Full Text Available We have fabricated poly(3-hexylthiophene (P3HT/copper phthalocyanine (CuPc/fullerene (C60 ternary blend films. This photoactive layer is sandwiched between an indium tin oxide (ITO/poly(3,4-ethylenedioxythiophene:poly(styrene sulfonate (PEDOT/PSS photoanode and a bathocuproine (BCP/aluminium photocathode. The thin films have been characterized by atomic force microscope (AFM and ultraviolet/visible spectroscopy in order to study the influence of P3HT doping on the morphological and optical properties of the photoactive layer. We have also compared the characteristics of three different organic solar cells: ITO/PEDOT:PSS/CuPc0.5:C600.5/BCP/Al and ITO/PEDOT:PSS/P3HT0.3:CuPc0.3:C600.4/BCP/Al with and without annealing. Both structures show good photovoltaic behaviour. Indeed, the incorporation of P3HT into CuPc:C60 thin film improves all the photovoltaic characteristics. We have also seen that thermal annealing significantly improves the optical absorption ability and stabilizes the organic solar cells making it more robust to chemical degradation.

Voltammetric, in-situ spectroelectrochemical and in-situ electrocolorimetric characterization of phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Koca, Atif [Department of Chemical Engineering, Faculty of Engineering, Marmara University, Goeztepe, 34722 Istanbul (Turkey)], E-mail: akoca@eng.marmara.edu.tr; Bayar, Serife; Dincer, Hatice A. [Department of Chemistry, Technical University of Istanbul, Maslak, 34469 Istanbul (Turkey); Gonca, Erguen [Department of Chemistry, Fatih University, TR34500 B.Cekmece, Istanbul (Turkey)

2009-04-01

In this work, electrochemical, and in-situ spectroelectrochemical characterization of the metallophthalocyanines bearing tetra-(1,1-(dicarbethoxy)-2-(2-methylbenzyl))-ethyl 3,10,17,24-tetra chloro groups were performed. Voltammetric and in-situ spectroelectrochemical measurements show that while cobalt phthalocyanine complex gives both metal-based and ring-based redox processes, zinc and copper phthalocyanines show only ring-based reduction and oxidation processes. The redox processes are generally diffusion-controlled, reversible and one-electron transfer processes. Differently lead phthalocyanine demetallized during second oxidation reaction while it was stable during reduction processes. An in-situ electrocolorimetric method, based on the 1931 CIE (Commission Internationale de l'Eclairage) system of colorimetry, has been applied to investigate the color of the electro-generated anionic and cationic forms of the complexes for the first time in this study.

Ambipolar Cu- and Fe-phthalocyanine single-crystal field-effect transistors

NARCIS (Netherlands)

De Boer, R.W.I.; Stassen, A.F.; Craciun, M.F.; Mulder, C.L.; Molinari, A.; Rogge, S.; Morpurgo, A.F.

2005-01-01

We report the observation of ambipolar transport in field-effect transistors fabricated on single crystals of copper- and iron-phthalocyanine, using gold as a high work-function metal for the fabrication of source and drain electrodes. In these devices, the room-temperature mobility of holes reaches

Low voltage operating OFETs based on solution processed metal phthalocyanines

Czech Academy of Sciences Publication Activity Database

Chaidogiannos, G.; Petraki, F.; Glezos, N.; Kennou, S.; Nešpůrek, Stanislav

2009-01-01

Roč. 96, č. 3 (2009), s. 763-767 ISSN 0947-8396 R&D Projects: GA AV ČR KAN400720701 Institutional research plan: CEZ:AV0Z40500505 Keywords : field-effect transistors * thin-film transistors * copper phthalocyanine Subject RIV: CG - Electrochemistry Impact factor: 1.595, year: 2009

Short-lived γ-emitting metal isotopes phthalocyanine tetrasulfonic acid

International Nuclear Information System (INIS)

Lier, J. Van; Rousseau, J.; Autenrieth, D.

1981-01-01

New phthalocyanine tetrasulfonic acid metal complexes selected from technetium-99m, gallium-67, gallium-68, copper-64, chromium-51, cobalt-57, indium-111, mercury-197 and zinc-62 have been found to have affinity for malignant growth and thus are useful in detecting the presence, size and location thereof with radiation imaging device. (author)

Novel non-symmetrical bifunctionally-substituted phthalonitriles and corresponding d-metal phthalocyaninates

Science.gov (United States)

Vashurin, Artur; Maizlish, Vladimir; Tikhomirova, Tatiyana; Nemtseva, Marina; Znoyko, Serafima; Aleksandriiskii, Viktor

2018-05-01

The work reports synthesis of 4-(2-tert-butyl-4,5-dicyanophenylsulfonyl)benzene and its analogue containing carboxyl group in phenyl fragment by nucleophilic substitution of nitro-group of 4-tert-butyl-5-nitrophthalonitrile. Unique structure of the obtained compounds is explained by presence of bulky tert-butyl substituent in combination with carboxyl group, which being part of phthalocyanine molecule impart it higher solubility within different solvents (organic and water mediums) and act as anchoring groups. Based on obtained nitriles phthalocyanine complexes of copper, nickel, cobalt and magnesium are synthesized with good yields. Demetallization of initial magnesium phthalocyanine by hydrochloric acid was performed in order to obtain ligand of phthalocyanine. Synthetic and purification techniques are described in detail. Obtained substances are of specific structure making them to be applied in sensorics for smart materials production, as sensitizers or part of molecular magnets. The structure, NMR and IR spectra are modeled using special software. Resulting experimental and theoretical data are compared. The results show sufficient correlation that confirms correctness of chosen methods and its applicability for theoretical studying compounds related to investigated ones.

Layer-by-layer self-assembling copper tetrasulfonated phthalocyanine on carbon nanotube modified glassy carbon electrode for electro-oxidation of 2-mercaptoethanol

International Nuclear Information System (INIS)

Shaik, Mahabul; Rao, V.K.; Gupta, Manish; Pandey, P.

2012-01-01

This paper describes the electrocatalytic activity of layer-by-layer self-assembled copper tetrasulfonated phthalocyanine (CuPcTS) on carbon nanotube (CNT)-modified glassy carbon (GC) electrode. CuPcTS is immobilized on the negatively charged CNT surface by alternatively assembling a cationic poly(diallyldimethylammonium chloride) (PDDA) layer and a CuPcTS layer. UV–vis absorption spectra and electrochemical measurements suggested the successive linear depositions of the bilayers of CuPcTs and PDDA on CNT. The surface morphology was observed using scanning electron microscopy. The viability of this CuPcTS/PDDA/CNT modified GC electrode as a redox mediator for the anodic oxidation and sensitive amperometric determination of 2-mercaptoethanol (2-ME) in alkaline conditions is described. The effect of number of bilayers of CuPcTS/PDDA and pH on electrochemical oxidation of 2-ME was studied. The proposed electrochemical sensor displayed excellent characteristics towards the determination of 2-ME in 0.1 M NaOH; such as low overpotentials (− 0.15 V vs Ag/AgCl), linear concentration range of 3 × 10 −5 M to 6 × 10 −3 M, and with a detection limit of 2.5 × 10 −5 M using simple amperometry. - Highlights: ► Carbon nanotubes (CNT) were drop-dried on glassy carbon electrode (GCE). ► Copper tetrasulfonated phthalocyanine (CuPcTS) was deposited on CNT/GCE. ► Layer-by-layer self-assembling method is used for depositing CuPcTS. ► Electrocatalytic oxidation of 2-mercaptoethanol (ME) was studied at this electrode ► The detection limit of ME at modified electrode was 25 μM by amperometry.

Hubungan Tingkat Kecemasan dalam Menghadapi Objective Structured Clinical Examination (OSCE dengan Kelulusan OSCE pada Mahasiswa Fakultas Kedokteran Universitas Andalas

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Dinda Putri Amir

2016-01-01

Full Text Available AbstrakKecemasan adalah normal terjadi dalam kehidupan, namun kecemasan dapat menjadi abnormal jika respons terhadap stimulus berlebihan. Pada mahasiswa, kecemasan berpengaruh terhadap proses pendidikan. OSCE merupakan salah satu bagian dari ujian komprehensif yang menguji keterampilan medis mahasiswa yang akan memasuki kepaniteraan klinik. Ujian ini hampir sama dengan ujian skills lab, tapi materi ujian lebih banyak dan setting ujian juga berbeda sehingga situasi tersebut menimbulkan kecemasan pada mahasiswa menjelang OSCE. Tujuan penelitian ini adalah menentukan hubungan tingkat kecemasan dalam menghadapi OSCE dengan kelulusan OSCE pada mahasiwa FK Unand. Jenis penelitian ini adalah deskriptif analitik dengan sampel sebanyak 34 orang. Data diperoleh melalui wawancara kepada peserta OSCE menggunakan kuesioner Hamilton Rating Scale for Anxiety (HRS-A dan Bagian Akademik FK Unand yang selanjutnya dianalisis melalui uji korelasi Gamma dan Somers’d. Hasil penelitian ini didapatkan nilai koefisien korelasi (r sebesar -0,106 dan nilai signifikansi p>0,05. Berdasarkan hasil penelitian dapat disimpulkan bahwa tidak terdapat hubungan yang bermakna antara tingkat kecemasan dalam menghadapi OSCE dengan kelulusan OSCE pada mahasiwa FK Unand.Kata kunci: kecemasan, ujian, OSCE, HRS-A AbstractAnxiety normally occurs in life, but anxiety can become abnormal if the response to the stimulus is excessive. In student, anxiety affects the educational process. OSCE is a part of comprehensive exam that examine medical skills of the students who will enter their clinical stage. Although this exam is similiar like skills lab exam but the matters of exam is more complex and the setting of exam is different too, so these situations cause anxiety in students toward OSCE. The objective of this study was to determine the correlation between anxiety level in facing OSCE to students’ graduation of OSCE in Faculty of Medicine Andalas University. This study was a

The Psychiatry OSCE: a 20-year retrospective.

Science.gov (United States)

Hodges, Brian D; Hollenberg, Elisa; McNaughton, Nancy; Hanson, Mark D; Regehr, Glenn

2014-02-01

Twenty years ago researchers at the University of Toronto launched the Psychiatry Skills Assessment Project (PSAP), a research program exploring Objective Structured Clinical Examinations (OSCEs) in psychiatry. Between 1994 and 2005 PSAP produced publications on the feasibility, reliability, validity, ethics, and practical concerns of OSCEs in psychiatry. The current review has two parts: a review of the state of the art of OSCEs in psychiatry 20 years after they were introduced and documentation of the impact of the PSAP research program. A literature search identified all publications on OSCEs and psychiatry. Articles were coded thematically, and locations of agreement and controversies were identified. Bibliometric analysis identified citations of PSAP research papers, which were analyzed thematically. As of May 2013, there were 250 publications related to OSCEs in psychiatry (not including 10 PSAP papers), published in 29 different countries and ten languages. Prominent topics were the validity and acceptability of OSCEs and SPs, systems issues in adopting OSCEs in psychiatry, and the effects on learning. Eighty-eight percent of all publications cited PSAP work (300 citations). Citations were employed for four purposes: as evidence/justification (54 %); to frame replication research (14 %); to support adaptation of OSCEs in other countries and professions (15 %); and for debate (18 %). Over the past 20 years, use of OSCEs has grown steadily in psychiatry, and several national certification organizations have adopted OSCEs. PSAP work, introduced two decades ago, continues to provide a scholarly foundation for psychometric, practical, and ethical issues of interest to this field.

Phase and Texture of Solution-Processed Copper Phthalocyanine Thin Films Investigated by Two-Dimensional Grazing Incidence X-Ray Diffraction

Directory of Open Access Journals (Sweden)

Lulu Deng

2011-07-01

Full Text Available The phase and texture of a newly developed solution-processed copper phthalocyanine (CuPc thin film have been investigated by two-dimensional grazing incidence X-ray diffraction. The results show that it has β phase crystalline structure, with crystallinity greater than 80%. The average size of the crystallites is found to be about 24 nm. There are two different arrangements of crystallites, with one dominating the diffraction pattern. Both of them have preferred orientation along the thin film normal. Based on the similarities to the vacuum deposited CuPc thin films, the new solution processing method is verified to offer a good alternative to vacuum process, for the fabrication of low cost small molecule based organic photovoltaics.

Awarding global grades in OSCEs: evaluation of a novel eLearning resource for OSCE examiners.

Science.gov (United States)

Gormley, Gerard J; Johnston, Jenny; Thomson, Clare; McGlade, Kieran

2012-01-01

A novel online resource has been developed to aid OSCE examiner training comprising a series of videos of OSCE performances that allow inter-examiner comparison of global grade decisions. To evaluate this training resource in terms of usefulness and ability to improve examiner confidence in awarding global grades in OSCEs. Data collected from the first 200 users included global grades awarded, willingness to change grades following peer comparison and confidence in awarding grades before and after training. Most (86.5%) agreed that the resource was useful in developing global grade scoring ability in OSCEs, with a significant improvement in confidence in awarding grades after using the training package (p<0.001). This is a useful and effective online training package. As an adjunct to traditional training it offers a practical solution to the problem of availability of examiners.

Temporary tattoos: a novel OSCE assessment tool.

Science.gov (United States)

Gormley, Gerry; Menary, Allison; Layard, Brooke; Hart, Nigel; McCourt, Collette

2013-08-01

There are many issues regarding the use of real patients in objective structured clinical examinations (OSCEs). In dermatology OSCE stations, standardised patients (SPs) with clinical photographs are often used. Temporary transfer tattoos can potentially simulate skin lesions when applied to an SP. This study aims to appraise the use of temporary malignant melanoma tattoos within an OSCE framework. Within an 11-station OSCE, a temporary malignant melanoma tattoo was developed and applied to SPs in a 'skin lesion' OSCE station. A questionnaire captured the opinions of the candidate, SP and examiners, and the degree of perceived realism of each station was determined. Standard post hoc OSCE analysis determined the psychometric reliability of the stations. The response rates were 95.9 per cent of candidates and 100 per cent of the examiners and SPs. The 'skin lesion' station achieved the highest realism score compared with other stations: 89.0 per cent of candidates felt that the skin lesion appeared realistic; only 28 per cent of candidates had ever seen a melanoma before in training. The psychometric performance of the melanoma station was comparable with, and in many instances better than, other OSCE stations. Transfer tattoo technology facilitates a realistic dermatology OSCE station encounter. Temporary tattoos, alongside trained SPs, provide an authentic, standardised and reliable experience, allowing the assessment of integrated dermatology clinical skills. © 2013 John Wiley & Sons Ltd.

Hybrid Solar Cell with TiO2 Film: BBOT Polymer and Copper Phthalocyanine as Sensitizer

Directory of Open Access Journals (Sweden)

Saptadip Saha

2016-01-01

Full Text Available An organic-inorganic hybrid solar cell was fabricated using Titanium dioxide (TiO2: 2,5-bis(5-tert-butyl-2-benzoxazolyl thiophene (BBOT film and Copper Phthalocyanine (CuPc as a sensitizer. BBOT was used in photodetector in other reported research works, but as per best of our knowledge, it was not implemented in solar cells till date. The blend of TiO2: BBOT blend was used to fabricate the film on ITO-coated glass and further a thin layer of CuPc was coated on the film. This was acted as photoanode and another ITO coated glass with a platinum coating was used as a counter electrode (cathode. An optimal blend of acetonitrile (solvent (50-100%, 1,3-dimethylimidazolium iodide (10-25%, iodine (2.5-10% and lithium iodide, pyridine derivative and thiocyanate was used as electrolytes in the hybrid solar cell. The different structural, optical and electrical characteristics were measured. The Hybrid solar cell showed a maximum conversion efficiency of 6.51%.

Implementation of an OSCE at Kaohsiung Medical University

Directory of Open Access Journals (Sweden)

Yu-Sheng Huang

2007-04-01

Full Text Available The Objective Structured Clinical Examination (OSCE, a tool to objectively and fairly assess medical students' clinical competences, has become widely used in medical education worldwide. However, most medical schools in Taiwan have just begun to adopt this assessment method. In 2003, Kaohsiung Medical University (KMU established the first standardized patient (SP program in Taiwan and applied SPs with an OSCE. This study reports the process of the implementation of an OSCE at KMU, which includes collecting information, visiting leading clinical skills centers, consulting medical educators from other countries, holding international conferences, establishing an OSCE committee, writing cases, training SPs, administrating the OSCE, and receiving feedback from medical students. Most students were satisfied with the assessment and appreciated the learning experience. Based on the experience in 2003, the OSCE committee decided to incorporate the OSCE into the medical curriculum as a measure to assess medical students' clinical competences. In addition to assessing medical students' clinical competence, the OSCE can also be applied to other professional health education, such as dentistry, nursing, and pharmacy. We are currently sharing our experience with other colleges at KMU.

Rasch analysis on OSCE data : An illustrative example.

Science.gov (United States)

Tor, E; Steketee, C

2011-01-01

The Objective Structured Clinical Examination (OSCE) is a widely used tool for the assessment of clinical competence in health professional education. The goal of the OSCE is to make reproducible decisions on pass/fail status as well as students' levels of clinical competence according to their demonstrated abilities based on the scores. This paper explores the use of the polytomous Rasch model in evaluating the psychometric properties of OSCE scores through a case study. The authors analysed an OSCE data set (comprised of 11 stations) for 80 fourth year medical students based on the polytomous Rasch model in an effort to answer two research questions: (1) Do the clinical tasks assessed in the 11 OSCE stations map on to a common underlying construct, namely clinical competence? (2) What other insights can Rasch analysis offer in terms of scaling, item analysis and instrument validation over and above the conventional analysis based on classical test theory? The OSCE data set has demonstrated a sufficient degree of fit to the Rasch model (Χ(2) = 17.060, DF=22, p=0.76) indicating that the 11 OSCE station scores have sufficient psychometric properties to form a measure for a common underlying construct, i.e. clinical competence. Individual OSCE station scores with good fit to the Rasch model (p > 0.1 for all Χ(2) statistics) further corroborated the characteristic of unidimensionality of the OSCE scale for clinical competence. A Person Separation Index (PSI) of 0.704 indicates sufficient level of reliability for the OSCE scores. Other useful findings from the Rasch analysis that provide insights, over and above the analysis based on classical test theory, are also exemplified using the data set. The polytomous Rasch model provides a useful and supplementary approach to the calibration and analysis of OSCE examination data.

Taking OSCE examiner training on the road: reaching the masses.

Science.gov (United States)

Reid, Katharine; Smallwood, David; Collins, Margo; Sutherland, Ruth; Dodds, Agnes

To ensure the rigour of objective structured clinical examinations (OSCEs) in assessing medical students, medical school educators must educate examiners with a view to standardising examiner assessment behaviour. Delivering OSCE examiner training is a necessary yet challenging part of the OSCE process. A novel approach to implementing training for current and potential OSCE examiners was trialled by delivering large-group education sessions at major teaching hospitals. The 'OSCE Roadshow' comprised a short training session delivered in the context of teaching hospital 'Grand Rounds' to current and potential OSCE examiners. The training was developed to educate clinicians about OSCE processes, clarify the examiners' role and required behaviours, and to review marking guides and mark allocation in an effort to standardise OSCE processes and encourage consistency in examiner marking behaviour. A short exercise allowed participants to practise marking a mock OSCE to investigate examiner marking behaviour after the training. OSCE Roadshows at four metropolitan and one rural teaching hospital were well received and well attended by 171 clinicians across six sessions. Unexpectedly, medical students also attended in large numbers ( n= 220). After training, participants' average scores for the mock OSCE clustered closely around the ideal score of 28 (out of 40), and the average scores did not differ according to the levels of clinical experience. The OSCE Roadshow demonstrated the potential of brief familiarisation training in reaching large numbers of current and potential OSCE examiners in a time and cost-effective manner to promote standardisation of OSCE processes.

Does student performance on preclinical OSCEs relate to clerkship grades?

Science.gov (United States)

Chima, Margot; Dallaghan, Gary Beck

2016-01-01

Objective structured clinical examinations (OSCEs) have been used to assess the clinical competence and interpersonal skills of healthcare professional students for decades. However, the relationship between preclinical (second year or M2) OSCE grades and clerkship performance had never been evaluated, until it was explored to provide information to educators at the University of Nebraska Medical Center (UNMC). In addition, the relationship between M2 OSCE communication scores (which is a portion of the total score) and third-year (M3) Internal Medicine (IM) clerkship OSCE scores was also explored. Lastly, conflicting evidence exists about the relationship between the amount of previous clinical experience and OSCE performance. Therefore, the relationship between M3 IM clerkship OSCE scores and the timing of the clerkship in the academic year was explored. Data from UNMC M2 OSCEs and M3 IM clerkship OSCEs were obtained for graduates of the 2013 and 2014 classes. Specifically, the following data points were collected: M2 fall OSCE total, M2 fall OSCE communication; M2 spring OSCE total, M2 spring OSCE communication; and M3 IM clerkship OSCE total percentages. Data were organized by class, M3 IM clerkship OSCE performance, and timing of the clerkship. Microsoft Excel and SPSS were used for data organization and analysis. Of the 245 records, 229 (93.5%) had data points for all metrics of interest. Significant differences between the classes of 2013 and 2014 existed for average M2 spring total, M2 spring communication, and M3 IM clerkship OSCEs. Retrospectively, there were no differences in M2 OSCE performances based on how students scored on the M3 IM clerkship OSCE. M3 IM clerkship OSCE performance improved for those students who completed the clerkship last in the academic year. There were inconsistencies in OSCE performances between the classes of 2013 and 2014, but more information is needed to determine if this is because of testing variability or heterogeneity

Does student performance on preclinical OSCEs relate to clerkship grades?

Directory of Open Access Journals (Sweden)

Margot Chima

2016-06-01

Full Text Available Background: Objective structured clinical examinations (OSCEs have been used to assess the clinical competence and interpersonal skills of healthcare professional students for decades. However, the relationship between preclinical (second year or M2 OSCE grades and clerkship performance had never been evaluated, until it was explored to provide information to educators at the University of Nebraska Medical Center (UNMC. In addition, the relationship between M2 OSCE communication scores (which is a portion of the total score and third-year (M3 Internal Medicine (IM clerkship OSCE scores was also explored. Lastly, conflicting evidence exists about the relationship between the amount of previous clinical experience and OSCE performance. Therefore, the relationship between M3 IM clerkship OSCE scores and the timing of the clerkship in the academic year was explored. Methods: Data from UNMC M2 OSCEs and M3 IM clerkship OSCEs were obtained for graduates of the 2013 and 2014 classes. Specifically, the following data points were collected: M2 fall OSCE total, M2 fall OSCE communication; M2 spring OSCE total, M2 spring OSCE communication; and M3 IM clerkship OSCE total percentages. Data were organized by class, M3 IM clerkship OSCE performance, and timing of the clerkship. Microsoft Excel and SPSS were used for data organization and analysis. Results: Of the 245 records, 229 (93.5% had data points for all metrics of interest. Significant differences between the classes of 2013 and 2014 existed for average M2 spring total, M2 spring communication, and M3 IM clerkship OSCEs. Retrospectively, there were no differences in M2 OSCE performances based on how students scored on the M3 IM clerkship OSCE. M3 IM clerkship OSCE performance improved for those students who completed the clerkship last in the academic year. Conclusions: There were inconsistencies in OSCE performances between the classes of 2013 and 2014, but more information is needed to determine if

Taking OSCE examiner training on the road: reaching the masses

Directory of Open Access Journals (Sweden)

Katharine Reid

2016-09-01

Full Text Available Background: To ensure the rigour of objective structured clinical examinations (OSCEs in assessing medical students, medical school educators must educate examiners with a view to standardising examiner assessment behaviour. Delivering OSCE examiner training is a necessary yet challenging part of the OSCE process. A novel approach to implementing training for current and potential OSCE examiners was trialled by delivering large-group education sessions at major teaching hospitals. Methods: The ‘OSCE Roadshow’ comprised a short training session delivered in the context of teaching hospital ‘Grand Rounds’ to current and potential OSCE examiners. The training was developed to educate clinicians about OSCE processes, clarify the examiners’ role and required behaviours, and to review marking guides and mark allocation in an effort to standardise OSCE processes and encourage consistency in examiner marking behaviour. A short exercise allowed participants to practise marking a mock OSCE to investigate examiner marking behaviour after the training. Results: OSCE Roadshows at four metropolitan and one rural teaching hospital were well received and well attended by 171 clinicians across six sessions. Unexpectedly, medical students also attended in large numbers (n=220. After training, participants’ average scores for the mock OSCE clustered closely around the ideal score of 28 (out of 40, and the average scores did not differ according to the levels of clinical experience. Conclusion: The OSCE Roadshow demonstrated the potential of brief familiarisation training in reaching large numbers of current and potential OSCE examiners in a time and cost-effective manner to promote standardisation of OSCE processes.

Rasch analysis on OSCE data : An illustrative example

Directory of Open Access Journals (Sweden)

Tor E

2011-06-01

Full Text Available BackgroundThe Objective Structured Clinical Examination (OSCE is awidely used tool for the assessment of clinical competencein health professional education. The goal of the OSCE is tomake reproducible decisions on pass/fail status as well asstudents’ levels of clinical competence according to theirdemonstrated abilities based on the scores. This paperexplores the use of the polytomous Rasch model inevaluating the psychometric properties of OSCE scoresthrough a case study.MethodThe authors analysed an OSCE data set (comprised of 11stations for 80 fourth year medical students based on thepolytomous Rasch model in an effort to answer tworesearch questions: (1 Do the clinical tasks assessed in the11 OSCE stations map on to a common underlyingconstruct, namely clinical competence? (2 What otherinsights can Rasch analysis offer in terms of scaling, itemanalysis and instrument validation over and above theconventional analysis based on classical test theory?ResultsThe OSCE data set has demonstrated a sufficient degree offit to the Rasch model (χ2 = 17.060, DF=22, p=0.76indicating that the 11 OSCE station scores have sufficientpsychometric properties to form a measure for a commonunderlying construct, i.e. clinical competence. IndividualOSCE station scores with good fit to the Rasch model (p >0.1 for all χ2 statistics further corroborated thecharacteristic of unidimensionality of the OSCE scale forclinical competence. A Person Separation Index (PSI of0.704 indicates sufficient level of reliability for the OSCEscores. Other useful findings from the Rasch analysis thatprovide insights, over and above the analysis based onclassical test theory, are also exemplified using the data set.ConclusionThe polytomous Rasch model provides a useful andsupplementary approach to the calibration and analysis ofOSCE examination data.

Electrodeposition of zinc oxide/tetrasulfonated copper phthalocyanine hybrid thin film for dye-sensitized solar cell application

International Nuclear Information System (INIS)

Luo Xinze; Xu Lin; Xu Bingbing; Li Fengyan

2011-01-01

Hybrid film of zinc oxide (ZnO) and tetrasulfonated copper phthalocyanine (TSPcCu) was grown on an indium tin oxide (ITO) glass by one-step cathodic electrodeposition from aqueous mixtures of Zn(NO 3 ) 2 , TSPcCu and KCl. The addition of TSPcCu strongly influences the morphology and crystallographic orientation of the ZnO. The nanosheets stack of ZnO leads to a porous surface structure which is advantageous to further adsorb organic dyes. The photovoltaic properties were investigated by assembling the DSSC device based on both the only ZnO film and the ZnO/TSPcCu hybrid films. Photoelectrochemical analysis revealed that the optimized DSSC device with TSPcCu represented a more than three-fold improvement in power conversion efficiency than the device without TSPcCu. The DSSC based on ZnO/TSPcCu hybrid films demonstrates an open circuit voltage of 0.308 V, a short circuit current of 90 μA cm -2 , a fill factor of 0.26, and a power conversion efficiency of 0.14%.

Electrodeposition of zinc oxide/tetrasulfonated copper phthalocyanine hybrid thin film for dye-sensitized solar cell application

Energy Technology Data Exchange (ETDEWEB)

Luo Xinze [Key Laboratory of Polyoxometalates Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China); College of Chemistry and Biological Science, Yili Normal University, Yining 835000, (China); Xu Lin, E-mail: linxu@nenu.edu.cn [Key Laboratory of Polyoxometalates Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China); Xu Bingbing; Li Fengyan [Key Laboratory of Polyoxometalates Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China)

2011-05-15

Hybrid film of zinc oxide (ZnO) and tetrasulfonated copper phthalocyanine (TSPcCu) was grown on an indium tin oxide (ITO) glass by one-step cathodic electrodeposition from aqueous mixtures of Zn(NO{sub 3}){sub 2}, TSPcCu and KCl. The addition of TSPcCu strongly influences the morphology and crystallographic orientation of the ZnO. The nanosheets stack of ZnO leads to a porous surface structure which is advantageous to further adsorb organic dyes. The photovoltaic properties were investigated by assembling the DSSC device based on both the only ZnO film and the ZnO/TSPcCu hybrid films. Photoelectrochemical analysis revealed that the optimized DSSC device with TSPcCu represented a more than three-fold improvement in power conversion efficiency than the device without TSPcCu. The DSSC based on ZnO/TSPcCu hybrid films demonstrates an open circuit voltage of 0.308 V, a short circuit current of 90 {mu}A cm{sup -2}, a fill factor of 0.26, and a power conversion efficiency of 0.14%.

Adsorption of Cu phthalocyanine on Pt modified Ge(001): A scanning tunneling microscopy study

NARCIS (Netherlands)

Saedi, A.; Berkelaar, Robin P.; Kumar, Avijit; Poelsema, Bene; Zandvliet, Henricus J.W.

2010-01-01

The adsorption configurations of copper phthalocyanine (CuPc) molecules on platinum-modified Ge(001) have been studied using scanning tunneling microscopy. After deposition at room temperature and cooling down to 77 K the CuPc molecules are still dynamic. However, after annealing at 550±50 K, the

Controllable preparation of copper phthalocyanine single crystal nano column and its chlorine gas sensing properties

Directory of Open Access Journals (Sweden)

Jianhong Zhao

2016-09-01

Full Text Available The unsubstituted copper phthalocyanine (CuPc single crystal nano columns were fabricated for the first time as chlorine (Cl2 gas sensors in this paper. The nano columns of CuPc have been prepared on different substrates via template-free physical vapor deposition (PVD approach. The growth mechanism of CuPc nano column on quartz was explored and the same condition used on other substrates including glass, sapphire (C-plane, M-plane, R-plane, Si and SiO2/Si came to a same conclusion, which confirmed that the aligned growth of CuPc nano column is not substrate-dependent. And then the CuPc nano column with special morphology was integrated as in-situ sensor device which exhibits high sensitivity and selectivity towards Cl2 at room temperature with a minimum detection limit as low as 0.08 ppm. The response of sensor was found to increase linearly (26∼659% with the increase for Cl2 within concentration range (0.08∼4.0ppm. These results clearly demonstrate the great potential of the nano column growth and device integration approach for sensor device.

Task Demands in OSCEs Influence Learning Strategies.

Science.gov (United States)

Lafleur, Alexandre; Laflamme, Jonathan; Leppink, Jimmie; Côté, Luc

2017-01-01

Models on pre-assessment learning effects confirmed that task demands stand out among the factors assessors can modify in an assessment to influence learning. However, little is known about which tasks in objective structured clinical examinations (OSCEs) improve students' cognitive and metacognitive processes. Research is needed to support OSCE designs that benefit students' metacognitive strategies when they are studying, reinforcing a hypothesis-driven approach. With that intent, hypothesis-driven physical examination (HDPE) assessments ask students to elicit and interpret findings of the physical exam to reach a diagnosis ("Examine this patient with a painful shoulder to reach a diagnosis"). When studying for HDPE, students will dedicate more time to hypothesis-driven discussions and practice than when studying for a part-task OSCE ("Perform the shoulder exam"). It is expected that the whole-task nature of HDPE will lead to a hypothesis-oriented use of the learning resources, a frequent use of adjustment strategies, and persistence with learning. In a mixed-methods study, 40 medical students were randomly paired and filmed while studying together for two hypothetical OSCE stations. Each 25-min study period began with video cues asking to study for either a part-task OSCE or an HDPE. In a crossover design, sequences were randomized for OSCEs and contents (shoulder or spine). Time-on-task for discussions or practice were categorized as "hypothesis-driven" or "sequence of signs and maneuvers." Content analysis of focus group interviews summarized students' perception of learning resources, adjustment strategies, and persistence with learning. When studying for HDPE, students allocate significantly more time for hypothesis-driven discussions and practice. Students use resources contrasting diagnoses and report persistence with learning. When studying for part-task OSCEs, time-on-task is reversed, spent on rehearsing a sequence of signs and maneuvers. OSCEs with

Ordering of Zn-centered porphyrin and phthalocyanine on TiO2(011: STM studies

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Piotr Olszowski

2017-01-01

Full Text Available Zn(IIphthalocyanine molecules (ZnPc were thermally deposited on a rutile TiO2(011 surface and on Zn(IImeso-tetraphenylporphyrin (ZnTPP wetting layers at room temperature and after elevated temperature thermal processing. The molecular homo- and heterostructures were characterized by high-resolution scanning tunneling microscopy (STM at room temperature and their geometrical arrangement and degree of ordering are compared with the previously studied copper phthalocyanine (CuPc and ZnTPP heterostructures. It was found that the central metal atom may play some role in ordering and growth of phthalocyanine/ZnTPP heterostructures, causing differences in stability of upright standing ZnPc versus CuPc molecular chains at given thermal annealing conditions.

The use of the OSCE in postgraduate education.

Science.gov (United States)

Arnold, R C; Walmsley, A D

2008-08-01

The Objective Structured Clinical Examination (OSCE) is a method of assessing the clinical skills of undergraduates in medicine, dentistry and other health sciences and is employed increasingly in postgraduate education. To describe the application of the OSCE to the development of Lifelong Learning and Continuing Professional Development (CPD) for General Dental Practitioners (GDPs). A postgraduate course was designed as an OSCE for GDPs. The OSCE comprised 12 stations covering different aspects of general dentistry. After an introductory seminar outlining the aim of the course, the participants spent 7 min at each station. Each question or task required 10 answers and was designed to highlight areas of weakness or interest and to stimulate further study of the presenting topic. Solutions and answers were provided at each station for self-assessment along with a list of locally presented courses related to that subject. Participants were invited to leave contact details and to make suggestions for future postgraduate courses. The final session consisted of a group discussion and participants were invited to complete an evaluation form to express opinions on the course. The evaluation demonstrated that most candidates found participation in the OSCE stimulated their interest in CPD. The OSCE also highlighted areas of weakness in knowledge of certain clinical procedures. Group discussion confirmed that practitioners found the hands-on component valuable and that they were likely to participate in further OSCEs to enhance their CPD. Suggestions received during the discussion were used to modify the course. The OSCE course fulfilled its aim of assisting practitioners to organise their CPD. The reflective nature of the course was helpful in evaluating clinical knowledge and the unique multidisciplinary style fulfilled its objective in promoting thoughts regarding future study.

Pabriks denied in OSCE challenge / Lelde Benke

Index Scriptorium Estoniae

Benke, Lelde

2010-01-01

OSCE parlamentaarse assamblee peasekretäriks sai uuesti Spencer Oliver, keda toetas 95% hääletanutest. Läti endine välisminister Artis Pabriks, kes tahtis muuta OSCE PA peasekretäri valimisprotsessi ja hääletussüsteemi, kaotas

Feedback in the OSCE: What Do Residents Remember?

Science.gov (United States)

Humphrey-Murto, Susan; Mihok, Marika; Pugh, Debra; Touchie, Claire; Halman, Samantha; Wood, Timothy J

2016-01-01

The move to competency-based education has heightened the importance of direct observation of clinical skills and effective feedback. The Objective Structured Clinical Examination (OSCE) is widely used for assessment and affords an opportunity for both direct observation and feedback to occur simultaneously. For feedback to be effective, it should include direct observation, assessment of performance, provision of feedback, reflection, decision making, and use of feedback for learning and change. If one of the goals of feedback is to engage students to think about their performance (i.e., reflection), it would seem imperative that they can recall this feedback both immediately and into the future. This study explores recall of feedback in the context of an OSCE. Specifically, the purpose of this study was to (a) determine the amount and the accuracy of feedback that trainees remember immediately after an OSCE, as well as 1 month later, and (b) assess whether prompting immediate recall improved delayed recall. Internal medicine residents received 2 minutes of verbal feedback from physician examiners in the context of an OSCE. The feedback was audio-recorded and later transcribed. Residents were randomly allocated to the immediate recall group (immediate-RG; n = 10) or the delayed recall group (delayed-RG; n = 8). The immediate-RG completed a questionnaire prompting recall of feedback received immediately after the OSCE, and then again 1 month later. The delayed-RG completed a questionnaire only 1 month after the OSCE. The total number and accuracy of feedback points provided by examiners were compared to the points recalled by residents. Results comparing recall at 1 month between the immediate-RG and the delayed-RG were also studied. Physician examiners provided considerably more feedback points (M = 16.3) than the residents recalled immediately after the OSCE (M = 2.61, p feedback points recalled upon completion of the OSCE (2.61) compared to 1 month later (M = 1

Item Analysis to Improve Reliability for an Internal Medicine Undergraduate OSCE

Science.gov (United States)

Auewarakul, Chirayu; Downing, Steven M.; Praditsuwan, Rungnirand; Jaturatamrong, Uapong

2005-01-01

Utilization of objective structured clinical examinations (OSCEs) for final assessment of medical students in Internal Medicine requires a representative sample of OSCE stations. The reliability and generalizability of OSCE scores provides validity evidence for OSCE scores and supports its contribution to the final clinical grade of medical…

Interaction of tricyclic drugs with copper phthalocyanine dye immobilized on magnetic carriers

Czech Academy of Sciences Publication Activity Database

Šafaříková, Miroslava; Šafařík, Ivo

3(Suppl.2), - (2002), s. 188-191 ISSN 1473-2262. [International Conference on the Scientific and Clinical Applications of Magnetic Carriers /4./. Tallahassee, 09.05.2002-11.05.2002] R&D Projects: GA MŠk OC 523.80; GA AV ČR IBS6087204 Institutional research plan: CEZ:AV0Z6087904 Keywords : magnetic * tricyclic drugs * phthalocyanine Subject RIV: CE - Biochemistry

Kremlin's OSCE Ministerial Council-related demarches / Rokas M. Tracevskis

Index Scriptorium Estoniae

Tracevskis, Rokas M.

2011-01-01

Detsembril alguses Vilniuses toimunud OSCE kohtumisel kritiseeris USA riigisekretär Hillary Clinton Venemaa parlamendivalimiste korraldamist. Venemaa peaminister Vladimir Putin ütles, et USA riigisekretäri kõne saatis Vene opositsioonile tegutsemissignaali. Venemaa välisministri Sergei Lavrovi ja Leedu välisministri Audronius Azubalise ebasõbralikust kohtumisest. Venemaa blokeeris OSCE-s internetivabaduse kaitsele suunatud deklaratsiooni

Electronic acquisition of OSCE performance using tablets

Directory of Open Access Journals (Sweden)

Hochlehnert, Achim

2015-10-01

Full Text Available Background: Objective Structured Clinical Examinations (OSCEs often involve a considerable amount of resources in terms of materials and organization since the scores are often recorded on paper. Computer-assisted administration is an alternative with which the need for material resources can be reduced. In particular, the use of tablets seems sensible because these are easy to transport and flexible to use.Aim: User acceptance concerning the use of tablets during OSCEs has not yet been extensively investigated. The aim of this study was to evaluate tablet-based OSCEs from the perspective of the user (examiner and the student examinee.Method: For two OSCEs in Internal Medicine at the University of Heidelberg, user acceptance was analyzed regarding tablet-based administration (satisfaction with functionality and the subjective amount of effort as perceived by the examiners. Standardized questionnaires and semi-standardized interviews were conducted (complete survey of all participating examiners. In addition, for one OSCE, the subjective evaluation of this mode of assessment was gathered from a random sample of participating students in semi-standardized interviews.Results: Overall, the examiners were very satisfied with using tablets during the assessment. The subjective amount of effort to use the tablet was found on average to be “hardly difficult”. The examiners identified the advantages of this mode of administration as being in particular the ease of use and low rate of error. During the interviews of the examinees, acceptance for the use of tablets during the assessment was also detected.Discussion: Overall, it was found that the use of tablets during OSCEs was well accepted by both examiners and examinees. We expect that this mode of assessment also offers advantages regarding assessment documentation, use of resources, and rate of error in comparison with paper-based assessments; all of these aspects should be followed up on in

Fluorinated copper-phthalocyanine-based n-type organic field-effect transistors with a polycarbonate gate insulator

International Nuclear Information System (INIS)

Sethuraman, Kunjithapatham; Kumar, Palanisamy; Santhakumar, Kannappan; Ochiai, Shizuyasu; Shin, Paikkyun

2012-01-01

Fluorinated copper-phthalocyanine (F 16 CuPc) thin films were prepared by using a vacuum evaporation technique and were applied to n-type organic field-effect transistors (OFETs) as active channel layers combined with a spin-coated polycarbonate thin-film gate insulator. The output characteristics of the resulting n-type OFET devices with bottom-gate/bottom-contact structures were investigated to evaluate the performances such as the field effect mobility (μ FE ), the on/off current ratio (I on/off ), and the threshold voltage (V th ). A relatively high field effect mobility of 6.0 x 10 -3 cm 2 /Vs was obtained for the n-type semiconductor under atmospheric conditions with an on/off current ratio of 1 x 10 4 and a threshold voltage of 5 V. The electron mobility of the n-type semiconductor was found to depend strongly on the growth temperature of the F 16 CuPc thin films. X-ray diffraction profiles showed that the crystallinity and the orientation of the F 16 CuPc on a polycarbonate thin film were enhanced with increasing growth temperature. Atomic force microscopy studies revealed various surface morphologies of the active layer. The field effect mobility of the F 16 CuPc-OFET was closely related to the crystallinity and the orientation of the F 16 CuPc thin film.

Asymmetric Response toward Molecular Fluorination in Binary Copper–Phthalocyanine/Pentacene Assemblies

DEFF Research Database (Denmark)

de Oteyza, D. G.; García Lastra, Juan Maria; Goiri, E.

2014-01-01

We report a didactic and simple example of the subtleness in the balance of intermolecular and molecule–substrate interactions and its effect on molecular self-assembly. The study is performed on two closely related molecular blends of copper phthalocyanines and pentacene, in each of which one of...... intermolecular interactions and a larger corrugation in the molecule–substrate interaction potential, results in a disordered layer. However, the difference between the two blend’s structures vanishes when substrates with less corrugated interaction potentials are used....

Synthesis, aggregation and spectroscopic studies of novel water soluble metal free, zinc, copper and magnesium phthalocyanines and investigation of their anti-bacterial properties

Science.gov (United States)

Bayrak, Rıza; Akçay, Hakkı Türker; Beriş, Fatih Şaban; Şahin, Ertan; Bayrak, Hacer; Demirbaş, Ümit

2014-12-01

In this study, novel phthalonitrile derivative (3) was synthesized by the reaction between 4-nitrophthalonitrile (2) and a triazole derivative (1) containing pyridine moiety. Crystal structure of compound (3) was characterized by X-ray diffraction. New metal free and metallo-phthalocyanine complexes (Zn, Cu, and Mg) were synthesized using the phthalonitrile derivative (3). Cationic derivatives of these phthalocyanines (5, 7, 9, and 11) were prepared from the non-ionic phthalocyanines (4, 6, 8, and 10). All proposed structures were supported by instrumental methods. The aggregation behaviors of the phthalocyanines (4-11) were investigated in different solvents such as dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), chloroform and water. Water soluble cationic Pcs (5, 7, 9, and 11) aggregated in water and sodium dodecyl sulfate was used to prevent the aggregation. The second derivatives of the UV-Vis spectra of aggregated Pcs were used for analyzing the Q and B bands of aggregated species. Thermal behaviors of the phthalocyanines were also studied. In addition, anti-bacterial properties of the phthalocyanines were investigated. We used four gram negative and two gram positive bacteria to determine antibacterial activity of these compounds. Compound 7 has the best activity against the all bacteria with 125 μg/mL of MIC value. Compounds 4, 6, and 10 have the similar effect on the bacteria with 250 μg/mL of MIC value.

Molecular mechanics calculations on cobalt phthalocyanine dimers

NARCIS (Netherlands)

Heuts, J.P.A.; Schipper, E.T.W.M.; Piet, P.; German, A.L.

1995-01-01

In order to obtain insight into the structure of cobalt phthalocyanine dimers, molecular mechanics calculations were performed on dimeric cobalt phthalocyanine species. Molecular mechanics calculations are first presented on monomeric cobalt(II) phthalocyanine. Using the Tripos force field for the

Enhancing OSCE preparedness with video exemplars in undergraduate nursing students. A mixed method study.

Science.gov (United States)

Massey, D; Byrne, J; Higgins, N; Weeks, B; Shuker, M-A; Coyne, E; Mitchell, M; Johnston, A N B

2017-07-01

Objective structured clinical examinations (OSCEs) are designed to assess clinical skill performance and competency of students in preparation for 'real world' clinical responsibilities. OSCEs are commonly used in health professional education and are typically associated with high levels of student anxiety, which may present a significant barrier to performance. Students, including nursing students, have identified that flexible access to exemplar OSCEs might reduce their anxiety and enable them to better prepare for such examinations. To implement and evaluate an innovative approach to preparing students for OSCEs in an undergraduate (registration) acute care nursing course. A set of digitized OSCE exemplars were prepared and embedded in the University-based course website as part of usual course learning activities. Use of the exemplars was monitored, pre and post OSCE surveys were conducted, and qualitative data were collected to evaluate the approach. OSCE grades were also examined. The online OSCE exemplars increased self-rated student confidence, knowledge, and capacity to prepare and provided clarity around assessment expectations. OSCE exemplars were accessed frequently and positively received; but did not impact on performance. Video exemplars aid student preparation for OSCEs, providing a flexible, innovative and clear example of the assessment process. Video exemplars improved self-rated student confidence and understanding of performance expectations, leading to increased engagement and reduced anxiety when preparing for the OSCE, but not overall OSCE performance. Such OSCE exemplars could be used to increase staff capacity and improve the quality of the student learning experience. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

An Electrochemical Quartz Crystal Microbalance Multisensor System Based on Phthalocyanine Nanostructured Films: Discrimination of Musts

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Celia Garcia-Hernandez

2015-11-01

Full Text Available An array of electrochemical quartz crystal electrodes (EQCM modified with nanostructured films based on phthalocyanines was developed and used to discriminate musts prepared from different varieties of grapes. Nanostructured films of iron, nickel and copper phthalocyanines were deposited on Pt/quartz crystals through the Layer by Layer technique by alternating layers of the corresponding phthalocyanine and poly-allylamine hydrochloride. Simultaneous electrochemical and mass measurements were used to study the mass changes accompanying the oxidation of electroactive species present in must samples obtained from six Spanish varieties of grapes (Juan García, Prieto Picudo, Mencía Regadío, Cabernet Sauvignon, Garnacha and Tempranillo. The mass and voltammetric outputs were processed using three-way models. Parallel Factor Analysis (PARAFAC was successfully used to discriminate the must samples according to their variety. Multi-way partial least squares (N-PLS evidenced the correlations existing between the voltammetric data and the polyphenolic content measured by chemical methods. Similarly, N-PLS showed a correlation between mass outputs and parameters related to the sugar content. These results demonstrated that electronic tongues based on arrays of EQCM sensors can offer advantages over arrays of mass or voltammetric sensors used separately.

USA ja Venemaa ristasid piike OSCE tuleviku pärast / Ahto Lobjakas

Index Scriptorium Estoniae

Lobjakas, Ahto, 1970-

2006-01-01

OSCE välisministrite kohtumiselt ei jõutud organisatsiooni tulevikus kokkuleppele. Kui USA nõuab, et OSCE-d tuleb tugevdada demokraatia edendajana ning valimiste aususe tagaja ja inimõiguste kaitsjana, siis Venemaa näeb sellises suunas liigset sekkumist liikmesriikide siseasjadesse

OSCE vs. TEM: Different approaches to assess clinical skills of nursing students

Directory of Open Access Journals (Sweden)

Prasuna Jelly

2017-01-01

Full Text Available Introduction: Nurses are trained with specific clinical skills, and objective structured clinical examination (OSCE could be a better approach to assess clinical skills of nursing students. Materials and Methods: A comparative study was conducted by observational checklist regarding antenatal care and opinionnaire on the usefulness of OSCE and tradition evaluation method (TEM was used to assess the clinical skills and to get opinion. Results: The mean score of OSCE was more than TEM and the difference was statistically significant (P < 0.001. The opinion of students regarding the usefulness of OSCE was higher than TEM. Conclusions: The study concluded that implementing OSCE will overweigh the advantages of the TEM.

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

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Satoru Mori

2017-10-01

Full Text Available Phthalocyanines and subphthalocyanines are attracting attention as functional dyes that are applicable to organic solar cells, photodynamic therapy, organic electronic devices, and other applications. However, phthalocyanines are generally difficult to handle due to their strong ability to aggregate, so this property must be controlled for further applications of phthalocyanines. On the other hand, trifluoroethoxy-substituted phthalocyanines are known to suppress aggregation due to repulsion of the trifluoroethoxy group. Furthermore, the electronic characteristics of phthalocyanines are significantly changed by the strong electronegativity of fluorine. Therefore, it is expected that trifluoroethoxy-substituted phthalocyanines can be applied to new industrial fields. This review summarizes the synthesis and application of trifluoroethoxy-substituted phthalocyanine and subphthalocyanine derivatives.

The Dental School Interview As a Predictor of Dental Students' OSCE Performance.

Science.gov (United States)

Park, Sang E; Price, Mirissa D; Karimbux, Nadeem Y

2018-03-01

The aim of this study was to evaluate the use of the dental school admissions interview score as a noncognitive indicator of performance in predoctoral dental education, with specific attention to whether a correlation existed between the admissions interview scores and performance on the objective structured clinical examination (OSCE). The study population consisted of all 175 students in the Harvard School of Dental Medicine (HSDM) DMD Classes of 2012 through 2016. Data on students' gender and age on entering dental school were self-reported using their applications for admission to the HSDM DMD program. Data on students' OSCE scores for three examination sessions were collected from the Office of Dental Education. The results showed that the students' interview scores did not significantly correlate with OSCE performance on any of the three exams. Performance on the first and second OSCEs did, however, correlate with performance on the third OSCE (pinterview score. These results suggest that although the admissions interview scores can serve as an important resource in student selection, with the lack of association between interview and OSCE scores, it is possible that the communication skills required for the interview do not directly overlap with those required for OSCE success.

Conducting Polymers Functionalized with Phthalocyanine as Nitrogen Dioxide Sensors

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S. D. Deshpande

2002-05-01

Full Text Available The conducting polymers such as polyaniline, polypyrrole and polythiophene were functionalized with copper phthalocyanine using chemical oxidation method. The obtained polymers viz. PANI-CuPc, PPy-CuPc and PT-CuPc were studied as chemical sensors by their response characteristics after exposure to various chemical vapors such as methanol, ammonia and nitrogen dioxide. The results obtained showed that these polymers have moderate sensitivity towards the methanol as well as ammonia vapors whereas they show tremendous sensitivity towards nitrogen dioxide vapors. The sensitivity factor of as high as 50,000 was obtained for PT-CuPc polymers in nitrogen dioxide. In comparison to this, the sensitivity factors of about 100 and 40 were obtained, when these polymers were exposed to ammonia and methanol vapors. The very high selectivity towards the nitrogen dioxide was explained on the basis of charge transfer complex formed between, the phthalocyanine donor and nitrogen dioxide acceptor molecules. On the other hand, ammonia becomes a competing electron donor in CuPc containing conducting polymers. The very low response towards the methanol may be explained on the basis very little charge transfer / interaction between CuPc containing polymers and methanol. Thus, CuPc incorporated conducting polymers have much higher selectivity than their original homopolymer.

Sulphonated metal phthalocyanine complexes as redox indicators in micro titrations with cerium(IV) sulphate

Energy Technology Data Exchange (ETDEWEB)

Gowda, H S; Achar, B N [Mysore Univ. (India). Dept. of Chemistry

1980-01-01

Tetrasodium salts of copper(II) 4,4', 4'', 4'''-tetrasulphophthalocyanine 2-hydrate, nickel(II) 4,4', 4'', 4'''-tetrasulphophthalocyanine, nickel(II) 3,3', 3'', 3'''-tetrasulphophthalocyanine and cobalt(II) 4,4', 4'', 4'''-tetrasulphophthalocyanine 2-hydrate, and copper phthalocyanine trisulphonic acid are prepared in pure state. The molar absorptivity and formal redox potentials of the complexes are determined. The complexes are proposed as sensitive redox indicators in the micro determination of iron(II), arsenic(III), molybdenum(V), uranium(IV) and hydroquinone with 0.001-0.0005N cerium(IV) sulphate in sulphuric, hydrochloric and acetic acid media. They give sharp colour change from light turquoise blue to pale purple colour at the equivalence point. They have advantages over a few existing redox indicators.

Objective structured clinical examination (OSCE in pharmacy education - a trend

Directory of Open Access Journals (Sweden)

Shirwaikar A

2015-12-01

Full Text Available Pharmacy education has undergone a radical change as it evolves towards becoming a more patient oriented profession. With a greater emphasis on problem based teaching and competency, the Objective Structured Clinical Examination (OSCE, supported by its reliability and validity became the gold standard for the evaluation of clinical skills of undergraduate students of medicine and pharmacy worldwide. Core competency evaluation has become a mandatory and critical norm for accountability of educational objectives as the traditional testing tools cannot evaluate clinical competence. Interpersonal and communication skills, professional judgment, skills of resolution etc., may be best assessed through a well- structured OSCE in comparison to oral examinations, multiple choice tests and other methods of assessment. Though OSCEs as an objective method of evaluation offer several advantages to both students and teachers, it also has disadvantages and pitfalls in implementation. This article reviews the OSCE as a trend in pharmacy education.

Application of best practice guidelines for OSCEs-An Australian evaluation of their feasibility and value.

Science.gov (United States)

Mitchell, Marion L; Henderson, Amanda; Jeffrey, Carol; Nulty, Duncan; Groves, Michele; Kelly, Michelle; Knight, Sabina; Glover, Pauline

2015-05-01

Objective Structured Clinical Examinations (OSCEs) are widely used in health professional education and should be based on sound pedagogical foundations. The aim of this study is to evaluate the feasibility and utility of using Best Practice Guidelines (BPGs) within an OSCE format in a broad range of tertiary education settings with under-graduate and post-graduate nursing and midwifery students. We evaluated how feasible it was to apply the BPGs to modify OSCEs in a course; students' perspective of the OSCE; and finally, if the BPG-revised OSCEs better prepared students for clinical practice when compared with the original OSCEs. A mixed method with surveys, focus groups and semi-structured interviews evaluated the BPGs within an OSCE. Four maximally different contexts across four sites in Australia were used. Participants included lecturers and undergraduate nursing students in high and low fidelity simulation settings; under-graduate midwifery students; and post-graduate rural and remote area nursing students. 691 students participated in revised OSCEs. Surveys were completed by 557 students; 91 students gave further feedback through focus groups and 14 lecturers participated in interviews. At all sites the BPGs were successfully used to modify and implement OSCEs. Students valued the realistic nature of the modified OSCEs which contributed to students' confidence and preparation for clinical practice. The lecturers considered the revised OSCEs enhanced student preparedness for their clinical placements. The BPGs have a broad applicability to OSCEs in a wide range of educational contexts with improved student outcomes. Students and lecturers identified the revised OSCEs enhanced student preparation for clinical practice. Subsequent examination of the BPGs saw further refinement to a set of eight BPGs that provide a sequential guide to their application in a way that is consistent with best practice curriculum design principles. Copyright © 2015 Elsevier Ltd

Hubungan Self Assessment-Peer Assessment dengan Nilai Kelulusan OSCE Mahasiswa Fakultas Kedokteran Unisba

Directory of Open Access Journals (Sweden)

Santun Bhekti Rahimah

2017-02-01

Full Text Available Abstrak Objective structured clinical examination (OSCE adalah cara penilaian kompetensi klinik mahasiswa secara komprehensif dan konsisten serta dapat dijadikan media untuk meningkatkan hasil belajar. Feedback dapat dilakukan oleh mahasiswa itu sendiri (self assessment maupun mahasiswa lain yang satu level (peer assessment. Self dan peer assessment diharapkan akan meningkatkan kemampuan mahasiswa dalam melihat tujuan pembelajaran, meningkatkan rasa percaya diri, kemampuan berpikir kritis, dan bertindak tepat dalam menghadapi ujian. Tujuan penelitian ini melihat hubungan self assessment dan peer assessment dengan nilai kelulusan OSCE mahasiswa tingkat dua dan empat FK Unisba tahun akademik 2012/2013. Nilai hasil ujian OSCE yang dipergunakan adalah pada periode Desember 2012–Juni 2013. Self dan peer assessment dilaksanakan setelah ujian OSCE. Self assessment dilakukan oleh mahasiswa itu sendiri, sedangkan peer assessment didapatkan dari lima orang mahasiswa lain yang pernah berada dalam satu kelompok dengan subjek. Hasil penelitian menunjukkan untuk mahasiswa tingkat dua terdapat korelasi bermakna self assessment dan peer assessment dengan nilai OSCE (p<0,001, arah hubungan antara keduanya positif, serta kekuatan hubungan keduanya sedang (R=0,426. Pada mahasiswa tingkat empat terdapat korelasi bermakna antara self assessment dan nilai OSCE (p<0,001 dengan kekuatan hubungan keduanya sedang (R=0,451, serta terdapat korelasi yang bermakna antara penilaian peer assessment dan nilai OSCE. Simpulan, self assessment mempunyai korelasi positif terhadap nilai kelulusan OSCE pada mahasiswa tingkat dua dan tingkat empat, sedangkan peer assessment mempunyai korelasi positif dengan nilai kelulusan OSCE hanya pada mahasiswa tingkat dua. Self assessment mempunyai korelasi positif dengan peer assessment pada mahasiswa tingkat dua dan tingkat empat FK Unisba tahun akademik 2012/2013. Abstract Objective structured clinical examination (OSCE is a tools to assess

Student reflections on learning cross-cultural skills through a 'cultural competence' OSCE.

Science.gov (United States)

Miller, Elizabeth; Green, Alexander R

2007-05-01

Medical schools use OSCEs (objective structured clinical examinations) to assess students' clinical knowledge and skills, but the use of OSCEs in the teaching and assessment of cross-cultural care has not been well described. To examine medical students' reflections on a cultural competence OSCE station as an educational experience. Students at Harvard Medical School in Boston completed a 'cultural competence' OSCE station (about a patient with uncontrolled hypertension and medication non-adherence). Individual semi-structured interviews were conducted with a convenience sample of twenty-two second year medical students, which were recorded, transcribed, and analysed. Students' reflections on what they learned as the essence of the case encompassed three categories: (1) eliciting the patient's perspective on their illness; (2) examining how and why patients take their medications and inquiring about alternative therapies; and (3) exploring the range of social and cultural factors associated with medication non-adherence. A cultural competence OSCE station that focuses on eliciting patients' perspectives and exploring medication non-adherence can serve as a unique and valuable teaching tool. The cultural competence OSCE station may be one pedagogic method for incorporating cross-cultural care into medical school curricula.

OSCE as a Summative Assessment Tool for Undergraduate Students of Surgery-Our Experience.

Science.gov (United States)

Joshi, M K; Srivastava, A K; Ranjan, P; Singhal, M; Dhar, A; Chumber, S; Parshad, R; Seenu, V

2017-12-01

Traditional examination has inherent deficiencies. Objective Structured Clinical Examination (OSCE) is considered as a method of assessment that may overcome many such deficits. OSCE is being increasingly used worldwide in various medical specialities for formative and summative assessment. Although it is being used in various disciplines in our country as well, its use in the stream of general surgery is scarce. We report our experience of assessment of undergraduate students appearing in their pre-professional examination in the subject of general surgery by conducting OSCE. In our experience, OSCE was considered a better assessment tool as compared to the traditional method of examination by both faculty and students and is acceptable to students and faculty alike. Conducting OSCE is feasible for assessment of students of general surgery.

Increased Authenticity in Practical Assessment Using Emergency Case OSCE Stations

Science.gov (United States)

Ruesseler, Miriam; Weinlich, Michael; Byhahn, Christian; Muller, Michael P.; Junger, Jana; Marzi, Ingo; Walcher, Felix

2010-01-01

In case of an emergency, a fast and structured patient management is crucial for patient's outcome. The competencies needed should be acquired and assessed during medical education. The objective structured clinical examination (OSCE) is a valid and reliable assessment format to evaluate practical skills. However, traditional OSCE stations examine…

Detection Learning Style Vark For Out Of School Children (OSC)

Science.gov (United States)

Amran, Ali; Desiani, Anita; Hasibuan, MS

2017-04-01

Learning style is different for every learner especially for out of school children or OSC. They are not like formal students, they are learners but they don’t have a teacher as a guide for learning. E-learning is one of the solutions to help OSC to get education. E-learning should have preferred learning styles of learners. Data for identifying the learning style in this study were collected with a VARK questionnaire from 25 OSC in junior high school level from 5 municipalities in Palembang. The validity of the questionnaire was considered on basis of experts’ views and its reliability was calculated by using Cronbach’s alpha coefficients (α=0.68). Overall, 55% preferred to use a single learning style (Uni-modal). Of these, 27,76% preferred Aural, 20,57% preferred Reading Writing, 33,33% preferred Kinaesthetic and 23,13% preferred Visual. 45% of OSC preferred more than one style, 30% chose two-modes (bimodal), and 15% chose three-modes (tri-modal). The Most preferred Learning style of OSC is kinaesthetic learning. Kinaesthetic learning requires body movements, interactivities, and direct contacts with learning materials, these things can be difficult to implement in eLearning, but E-learning should be able to adopt any learning styles which are flexible in terms of time, period, curriculum, pedagogy, location, and language.

The composite phthalocyanine-based Langmuir-Blodgett films: structural peculiarities and NO-sensitive properties

Energy Technology Data Exchange (ETDEWEB)

Emelianov, I.L.; Khatko, V.V. [Nat. Acad. of Sci., Minsk (Belarus). Phys. Tech. Inst.

1999-10-08

Surface pressure versus area per molecule isotherms of the Langmuir monolayers of copper tetra-tert-butyl phthalocyanine (abbreviated as CuTTBPc), arachidic acid (abbreviated as AA), and their mixtures were measured depending upon the film component ratio and ionic content of the subphase. Substantial deviations of the mixed monolayer behaviour from an ideal one, which is characteristic of fully immiscible compounds forming separate surface domains on the liquid subphase, were observed if the molar fraction of AA in mixed monolayers exceeded 50%. This abnormality in the monolayer behaviour correlated with the drastic changes in the kinetics responses to NO gas of the sensors based on the mixed Langmuir-Blodgett (LB) films. The comparison and analysis of the results obtained suggest that the gas-sensitive properties of the two-component LB films are determined by two features of their structure, namely, hole-like defects existing in the AA matrix and interlayer cavities. The corresponding structure model of the mixed films is proposed. The results obtained may be useful for understanding the gas-sensitive mechanism of the composite phthalocyanine-based LB films. (orig.)

Synthesis and photophysical properties of indium(III) phthalocyanine derivatives

Energy Technology Data Exchange (ETDEWEB)

Özceşmeci, İbrahim, E-mail: ozcesmecii@itu.edu.tr [Department of Chemistry, Technical University of Istanbul, Maslak 34469, Istanbul (Turkey); Gelir, Ali [Department of Physics, Technical University of Istanbul, Maslak 34469, Istanbul (Turkey); Gül, Ahmet [Department of Chemistry, Technical University of Istanbul, Maslak 34469, Istanbul (Turkey)

2014-03-15

Three chloroindium(III) phthalocyanine derivatives bearing four aromatic (naphthalene or pyrene) or aliphatic (hexylthio) groups were prepared from corresponding phthalonitrile compounds. The indium(III) phthalocyanine derivatives were characterized with elemental analyses, mass, proton nuclear magnetic resonance ({sup 1}H NMR), Fourier transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectroscopy (UV–vis) techniques. Quantum yields and the energy transfer from the substituents to phthalocyanine core were examined. No energy transfer was observed for 5. The energy transfer efficiency from pyrene units to indium phthalocyanine core was calculated as 0.27 for 6. Quantum yields of all samples were very small due to heavy atom effect of indium atom in the core. It was also observed that upon binding of pyrene and naphthalene units to indium phthalocyanine as substituents, the quantum yields of indium phthalocyanine parts of 5 and 6 decreased. -- Highlights: • Three chloroindium(III) phthalocyanines were prepared and characterized. • Aggregation properties of these compounds were investigated. • The energy transfer efficiency was examined. • Quantum yield of these systems were calculated.

Femtosecond time-resolved two-photon photoemission study of organic semiconductor copper phthalocyanine film

International Nuclear Information System (INIS)

Tanaka, A.; Tohoku University; University of Rochester, NY; Yan, L.; Watkins, N.J.; Gao, Y.

2004-01-01

Full text: Organic semiconductors are recently attracting much interest from the viewpoints of both device and fundamental physics. These organic semiconductors are considered to be important constituents of the future devices, such as organic light-emitting diode, organic field effect transistor, and organic solid-state injection laser. In order to elucidate their detailed physical properties and to develop the future devices, it is indispensable to understand their excited-state dynamics as well as their electronic structures. The femtosecond time-resolved two-photon photoemission (TR-2PPE) spectroscopy is attracting much interest because of its capability to observe the energy-resolved excited electron dynamics. In this work, we have carried out a TR-2PPE study of the organic semiconductor copper phthalocyanine (CuPc) film. Furthermore, we have investigated the detailed electronic structure of CuPc film using the photoemission (PES) and inverse photoemission (IPES) spectroscopies. From the simultaneous PES and IPES measurements for CuPc film with a thickness of 100 nm, the lowest unoccupied molecular orbital (LUMO), highest occupied molecular orbital, and ionization potential of CuPc film have been directly determined. The observed two-photon photoemission (2PPE) spectrum of the present CuPc film, measured with photon energy of about hv=3.3 eV, exhibits a broad feature. From the energy diagram of CuPc film determined by the PES and IPES measurements, the intermediate state observed in the present 2PPE spectrum of CuPc film corresponds to the energy region between about 0.4 and 1.7 eV above the LUMO energy. From the time-resolved pump-probe measurements, it is found that the relaxation lifetimes of excited states in the present CuPc films are very short (all below 50 fs) and monotonously become faster with increasing excitation energy. We attribute this extremely fast relaxation process of photoexcitation to a rapid internal conversion process. From these results

Room temperature ferromagnetism in a phthalocyanine based carbon material

International Nuclear Information System (INIS)

Honda, Z.; Sato, K.; Sakai, M.; Fukuda, T.; Kamata, N.; Hagiwara, M.; Kida, T.

2014-01-01

We report on a simple method to fabricate a magnetic carbon material that contains nitrogen-coordinated transition metals and has a large magnetic moment. Highly chlorinated iron phthalocyanine was used as building blocks and potassium as a coupling reagent to uniformly disperse nitrogen-coordinated iron atoms on the phthalocyanine based carbon material. The iron phthalocyanine based carbon material exhibits ferromagnetic properties at room temperature and the ferromagnetic phase transition occurs at T c  = 490 ± 10 K. Transmission electron microscopy observation, X-ray diffraction analysis, and the temperature dependence of magnetization suggest that the phthalocyanine molecules form three-dimensional random networks in the iron phthalocyanine based carbon material

Room temperature ferromagnetism in a phthalocyanine based carbon material

Energy Technology Data Exchange (ETDEWEB)

Honda, Z., E-mail: honda@fms.saitama-u.ac.jp; Sato, K.; Sakai, M.; Fukuda, T.; Kamata, N. [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Hagiwara, M.; Kida, T. [KYOKUGEN (Center for Quantum Science and Technology under Extreme Conditions), Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

2014-02-07

We report on a simple method to fabricate a magnetic carbon material that contains nitrogen-coordinated transition metals and has a large magnetic moment. Highly chlorinated iron phthalocyanine was used as building blocks and potassium as a coupling reagent to uniformly disperse nitrogen-coordinated iron atoms on the phthalocyanine based carbon material. The iron phthalocyanine based carbon material exhibits ferromagnetic properties at room temperature and the ferromagnetic phase transition occurs at T{sub c} = 490 ± 10 K. Transmission electron microscopy observation, X-ray diffraction analysis, and the temperature dependence of magnetization suggest that the phthalocyanine molecules form three-dimensional random networks in the iron phthalocyanine based carbon material.

Improvement of the photovoltaic parameters of perovskite solar cells using a reduced-graphene-oxide-modified titania layer and soluble copper phthalocyanine as a hole transporter.

Science.gov (United States)

Nouri, Esmaiel; Mohammadi, Mohammad Reza; Xu, Zong-Xiang; Dracopoulos, Vassilios; Lianos, Panagiotis

2018-01-24

Functional perovskite solar cells can be made by using a simple, inexpensive and stable soluble tetra-n-butyl-substituted copper phthalocyanine (CuBuPc) as a hole transporter. In the present study, TiO 2 /reduced graphene oxide (T/RGO) hybrids were synthesized via an in situ solvothermal process and used as electron acceptor/transport mediators in mesoscopic perovskite solar cells based on soluble CuBuPc as a hole transporter and on graphene oxide (GO) as a buffer layer. The impact of the RGO content on the optoelectronic properties of T/RGO hybrids and on the solar cell performance was studied, suggesting improved electron transport characteristics and photovoltaic parameters. An enhanced electron lifetime and recombination resistance led to an increase in the short circuit current density, open circuit voltage and fill factor. The device based on a T/RGO mesoporous layer with an optimal RGO content of 0.2 wt% showed 22% higher photoconversion efficiency and higher stability compared with pristine TiO 2 -based devices.

Layer-by-layer assembled highly absorbing hundred-layer films containing a phthalocyanine dye: Fabrication and photosensibilization by thermal treatment

International Nuclear Information System (INIS)

Sergeeva, Alena S.; Volkova, Elena K.; Bratashov, Daniil N.; Shishkin, Mikhail I.; Atkin, Vsevolod S.; Markin, Aleksey V.; Skaptsov, Aleksandr A.; Volodkin, Dmitry V.; Gorin, Dmitry A.

2015-01-01

Highly absorbing hundred-layer films based on poly(diallyldimethylammonium chloride) (PDADMAC) of various molecular weights and on sulfonated copper phthalocyanine (CuPcTs) were prepared using layer-by-layer assembly. The multilayer films grew linearly up to 54 bilayers, indicating that the same amount of CuPcTs was adsorbed at each deposition step. This amount, however, was dependent on the molecular weight of PDADMAC in the range 100-500 kDa: the higher the molecular weight, the more CuPcTs molecules were adsorbed. This can be explained by the larger surface charge number density specific to longer polymer chains. Domains of pure PDADMAC and of the PDADMAC/CuPcTs complex were formed in the films during the assembly. Uniform distribution of CuPcTs over the films could be achieved by thermal treatment, leading to an α → β phase transition in phthalocyanine at 300 °C. Annealing caused changes in the film absorbance spectra, resulting in a 30-nm red shift of the peak maxima and in a strong (up to 62%) decrease in optical density. Thermogravimetric analysis revealed thermodegradation of PDADMAC during annealing above 270 °C, giving rise to micrometer-sized cracks within the films, as evidenced by scanning electron microscopy. - Highlights: • The films exhibit the linear dependence of the adsorption on the bilayer number varied from 2 until 54. • Polyelectrolyte of the highest MW shows the maximal adsorption of copper phthalocyanine molecules. • Annealing of the films causes a red-shift of the maxima in the absorbance spectra. • Cracks and micropores emerged in the multilayer films during the annealing

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.

Photoinduced electron transfer between benzyloxy dendrimer phthalocyanine and benzoquinone

Science.gov (United States)

Zhang, Tiantian; Ma, Dongdong; Pan, Sujuan; Wu, Shijun; Jiang, Yufeng; Zeng, Di; Yang, Hongqin; Peng, Yiru

2016-10-01

Photo-induced electron transfer (PET) is an important and fundamental process in natural photosynthesis. To mimic such interesting PET process, a suitable donor and acceptor couple were properly chosen. Dendrimer phthalocyanines and their derivatives have emerged as promising materials for artificial photosynthesis systems. In this paper, the electron transfer between the light harvest dendrimer phthalocyanine (donor) and the 1,4-benzoquinone (acceptor) was studied by UV/Vis and fluorescence spectroscopic methods. It was found that fluorescence of phthalocyanine was quenched by benzoquinone (BQ) via excited state electron transfer, from the phthalocyanine to the BQ upon excitation at 610 nm. The Stern-Volmer constant (KSV) of electron transfer was calculated. Our study suggests that this dendritic phthalocyanine is an effective new electron donor and transmission complex and could be used as a potential artificial photosynthesis system.

Photophysical studies of zinc phthalocyanine and chloroaluminum phthalocyanine incorporated into liposomes in the presence of additives

Directory of Open Access Journals (Sweden)

S.M.T. Nunes

2004-02-01

Full Text Available The photophysical properties of zinc phthalocyanine (ZnPC and chloroaluminum phthalocyanine (AlPHCl incorporated into liposomes of dimyristoyl phosphatidylcholine in the presence and absence of additives such as cholesterol or cardiolipin were studied by time-resolved fluorescence, laser flash photolysis and steady-state techniques. The absorbance of the drugs changed linearly with drug concentration, at least up to 5.0 µM in homogeneous and heterogeneous media, indicating that aggregation did not occur in these media within this concentration range. The incorporation of the drugs into liposomes increases the dimerization constant by one order of magnitude (for ZnPC, 3.6 x 10(4 to 1.0 x 10(5 M-1 and for AlPHCl, 3.7 x 10(4 to 1.5 x 10(5 M-1, but this feature dose does not rule out the use of this carrier, since the incorporation of these hydrophobic drugs into liposomes permits their systemic administration. Probe location in biological membranes and predominant positions of the phthalocyanines in liposomes were inferred on the basis of their fluorescence and triplet state properties. Both phthalocyanines are preferentially distributed in the internal regions of the liposome bilayer. The additives affect the distribution of these drugs within the liposomes, a fact that controls their delivery when both are used in a biological medium, retarding their release. The addition of the additives to the liposomes increases the internalization of phthalocyanines. The interaction of the drugs with a plasma protein, bovine serum albumin, was examined quantitatively by the fluorescence technique. The results show that when the drugs were incorporated into small unilamellar liposomes, the association with albumin was enhanced when compared with organic media, a fact that should increase the selectivity of tumor targeting by these phthalocyanines (for ZnPC, 0.71 x 10(6 to 1.30 x 10(7 M-1 and for AlPHCl, 4.86 x 10(7 to 3.10 x 10(8 M-1.

Student evaluation of an OSCE in General Medicine at Mamata Medical College, Andhra Pradesh

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Dharma Rao V, Pramod Kumar Reddy M, Rajaneesh Reddy M, HanumiahA, Shyam Sunder P, Narasingha Reddy T, Kishore Babu SPV

2014-04-01

Full Text Available The assessment of student’s clinical competence is of paramount importance, and there are several means of evaluating student performance in medical examinations. The OSCE is an approach to student assessment in which aspects of clinical competence are evaluated in a comprehensive, consistent and structured manner with close attention to the objectivity of the process. The faculty of general medicine in collaboration with other clinical departments, Mamata Medical College, Khammam first implemented the objective structured clinical examination (OSCE in the final MBBS Part-II examination during the internal assessment examination for the 2011-2012 academic years. The study was set out to explore student acceptance of the OSCE as part of an evaluation of final MBBS students. A self-administered questionnaire was completed by successive groups of students immediately after the OSCE. Main outcome measures were student perception of examination attributes, which included the quality of instructions and organization, the quality of performance, authenticity and transparency of the process, and usefulness of the OSCE as an assessment instrument compared to other formats. There was an overwhelming acceptance of OSCE in general medicine with respect to comprehensiveness (90% transparency (90% & authenticity of required tasks. Students felt that it was a useful form of examination. Student’s feedback was invaluable in influencing faculty teaching curriculum direction and appreciation of student opinion and overall the students were agreeable with newer form of OSCE. The majority of the students felt that OSCE is a fair assessment tool compared to traditional long and short cases and it covers a wide range of knowledge and clinical skills in general medicine.

Exciplex mediated photoinduced electron transfer reactions of phthalocyanine-fullerene dyads

NARCIS (Netherlands)

Niemi, Marja; Tkachenko, Nikolai V.; Efimov, Alexander; Lehtivuori, Heli; Ohkubo, Kei; Fukuzumi, Shunichi; Lemmetyinen, Helge

2008-01-01

Evidences of an intramolecular exciplex intermediate in a photoinduced electron transfer (ET) reaction of double-linked free-base and zinc phthalocyanine-C-60 dyads were found. This was the first time for a dyad with phthalocyanine donor. Excitation of the phthalocyanine moiety of the dyads results

Medical students review of formative OSCE scores, checklists, and videos improves with student-faculty debriefing meetings.

Science.gov (United States)

Bernard, Aaron W; Ceccolini, Gabbriel; Feinn, Richard; Rockfeld, Jennifer; Rosenberg, Ilene; Thomas, Listy; Cassese, Todd

2017-01-01

Performance feedback is considered essential to clinical skills development. Formative objective structured clinical exams (F-OSCEs) often include immediate feedback by standardized patients. Students can also be provided access to performance metrics including scores, checklists, and video recordings after the F-OSCE to supplement this feedback. How often students choose to review this data and how review impacts future performance has not been documented. We suspect student review of F-OSCE performance data is variable. We hypothesize that students who review this data have better performance on subsequent F-OSCEs compared to those who do not. We also suspect that frequency of data review can be improved with faculty involvement in the form of student-faculty debriefing meetings. Simulation recording software tracks and time stamps student review of performance data. We investigated a cohort of first- and second-year medical students from the 2015-16 academic year. Basic descriptive statistics were used to characterize frequency of data review and a linear mixed-model analysis was used to determine relationships between data review and future F-OSCE performance. Students reviewed scores (64%), checklists (42%), and videos (28%) in decreasing frequency. Frequency of review of all metric and modalities improved when student-faculty debriefing meetings were conducted (p<.001). Among 92 first-year students, checklist review was associated with an improved performance on subsequent F-OSCEs (p = 0.038) by 1.07 percentage points on a scale of 0-100. Among 86 second year students, no review modality was associated with improved performance on subsequent F-OSCEs. Medical students review F-OSCE checklists and video recordings less than 50% of the time when not prompted. Student-faculty debriefing meetings increased student data reviews. First-year student's review of checklists on F-OSCEs was associated with increases in performance on subsequent F-OSCEs, however this

Photodynamics of charge separation and recombination in solid alternating films of phthalocyanine or phthalocyanine-fullerene dyad and perylene dicarboximide

NARCIS (Netherlands)

Lehtivuori, Heli; Kumpulainen, Tatu; Hietala, Matti; Efimov, Alexander; Helge, Lemmetyinen; Kira, Aiko; Imahori, Hiroshi; Tkachenko, Nikolai V.

2009-01-01

Alternate bilayer structures of N,N'-bis(2,5-di-tert-butylphenyl)-3,4,9,10- perylene dicarboximide (PDI), freebase phthalocyanines (Pc), and double-linked free-base phthalocyanine-fullerene dyad (Pc-C 60) were prepared by the Langmuir-Schäfer method and studied using a range of optical spectroscopy

An ultrafast study of Zinc Phthalocyanine in DMSO

CSIR Research Space (South Africa)

Ombinda-Lemboumba, Saturnin

2010-10-01

Full Text Available The ultrafast dynamics of Zinc Phthalocyanine was studied using trasient absorption pump probe spectroscopy. Zinc Phthalocyanine was excited (pumped) at 672nm and probed by a white light continuum. The pump-probe technique used in this study...

Synthesis of phthalocyanine doped sol-gel materials

Science.gov (United States)

Dunn, Bruce

1993-01-01

The synthesis of sol-gel silica materials doped with three different types of metallophthalocyanines has been studied. Homogeneous materials of good optical quality were prepared and the first optical limiting measurements of dyes in sol-gel hosts were carried out. The properties of these solid state limiters are similar to limiters based on phthalocyanine (Pc) in solution. Sol-gel silica materials containing copper, tin and germanium phthalocyanines were investigated. The initial step in all cases was to prepare silica sols by the sonogel method using tetramethoxy silane (TMOS), HCl and distilled water. Thereafter, the synthesis depended upon the specific Pc and its solubility characteristics. Copper phthalocyanine tetrasulfonic acid tetra sodium salt (CuPc4S) is soluble in water and various doping levels (1 x 10 (exp -4) M to 1 x 10 (exp -5) M) were added to the sol. The group IV Pc's, SnPc(OSi(n-hexyl)3)2 and GePc(OSi(n-hexyl)3)2, are insoluble in water and the process was changed accordingly. In these cases, the compounds were dissolved in THF and then added to the sol. The Pc concentration in the sol was 2 x 10(exp -5)M. The samples were then aged and dried in the standard method of making xerogel monoliths. Comparative nanosecond optical limiting experiments were performed on silica xerogels that were doped with the different metallophthalocyanines. The ratio of the net excited state absorption cross section (sigma(sub e)) to the ground state cross section (sigma(sub g)) is an important figure of merit that is used to characterize these materials. By this standard the SnPc sample exhibits the best limiting for the Pc doped sol-gel materials. Its cross section ratio of 19 compares favorably with the value of 22 that was measured in toluene. The GePc materials appear to not be as useful as those containing SnPc. The GePc doped solids exhibit a higher onset energy (2.5 mj and lower cross section ratio, 7. The CuPc4S sol-gel material has a still lower cross

Student evaluation of an OSCE in paediatrics at the University of the West Indies, Jamaica

Directory of Open Access Journals (Sweden)

Branday J Michael

2004-10-01

Full Text Available Abstract Background The Faculty of Medical Sciences, University of the West Indies first implemented the Objective Structured Clinical Examination (OSCE in the final MB Examination in Medicine and Therapeutics during the 2000–2001 academic year. Simultaneously, the Child Health Department initiated faculty and student training, and instituted the OSCE as an assessment instrument during the Child Health (Paediatric clerkship in year 5. The study set out to explore student acceptance of the OSCE as part of an evaluation of the Child Health clerkship. Methods A self-administered questionnaire was completed by successive groups of students immediately after the OSCE at the end of each clerkship rotation. Main outcome measures were student perception of examination attributes, which included the quality of instructions and organisation, the quality of performance, authenticity and transparency of the process, and usefulness of the OSCE as an assessment instrument compared to other formats. Results There was overwhelming acceptance of the OSCE in Child Health with respect to the comprehensiveness (90%, transparency (87%, fairness (70% and authenticity of the required tasks (58–78%. However, students felt that it was a strong anxiety-producing experience. And concerns were expressed regarding the ambiguity of some questions and inadequacy of time for expected tasks. Conclusion Student feedback was invaluable in influencing faculty teaching, curriculum direction and appreciation of student opinion. Further psychometric evaluation will strengthen the development of the OSCE.

Correlation between MMI performance and OSCE performance – a pilot study

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Adetokunbo Oluwasanjo

2015-06-01

Full Text Available Objective: The multiple mini-interview (MMI has been shown to have a positive correlation with early medical school performance, clerkship evaluations, and national licensing examinations. There is limited data on its predictive validity at the postgraduate level. Methods: Six hundred and nineteen internship candidates were interviewed using the MMI format by the internal medicine residency program of The Reading Health System, between September 2011 and February 2014. Fifty-two interns were recruited. Each intern participated in an objective structured clinical examination (OSCE 3–4 months after the start of the program. The OSCE score of each intern was used as the independent variable to test the relationship with both the MMI interpersonal score and the MMI overall score. Results: There was a moderate positive correlation between the average MMI interpersonal score and the communication score on the OSCE, r=0.384, n=52, p=0.005, and a negligible relationship between the average MMI overall score and the communication score on the OSCE, r=0.175, n=52, p=0.214. Conclusion: The MMI is a useful tool for residency programs to assess interpersonal and communication skills prior to matriculation into residency training. This study provides evidence for its validity in assessing these competencies.

Evaluating verbal and non-verbal communication skills, in an ethnogeriatric OSCE.

Science.gov (United States)

Collins, Lauren G; Schrimmer, Anne; Diamond, James; Burke, Janice

2011-05-01

Communication during medical interviews plays a large role in patient adherence, satisfaction with care, and health outcomes. Both verbal and non-verbal communication (NVC) skills are central to the development of rapport between patients and healthcare professionals. The purpose of this study was to assess the role of non-verbal and verbal communication skills on evaluations by standardized patients during an ethnogeriatric Objective Structured Clinical Examination (OSCE). Interviews from 19 medical students, residents, and fellows in an ethnogeriatric OSCE were analyzed. Each interview was videotaped and evaluated on a 14 item verbal and an 8 item non-verbal communication checklist. The relationship between verbal and non-verbal communication skills on interview evaluations by standardized patients were examined using correlational analyses. Maintaining adequate facial expression (FE), using affirmative gestures (AG), and limiting both unpurposive movements (UM) and hand gestures (HG) had a significant positive effect on perception of interview quality during this OSCE. Non-verbal communication skills played a role in perception of overall interview quality as well as perception of culturally competent communication. Incorporating formative and summative evaluation of both verbal and non-verbal communication skills may be a critical component of curricular innovations in ethnogeriatrics, such as the OSCE. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Resonance Raman spectra of phthalocyanine monolayers on different supports. A normal mode analysis of zinc phthalocyanine by means of the MNDO method

NARCIS (Netherlands)

Palys, Barbara J.; van den Ham, Dirk M.W.; van den Ham, D.M.W.; Briels, Willem J.; Feil, D.; Feil, Dirk

1995-01-01

Resonance Raman spectra of monolayers of transition metal phthalocyanines reveal specific interaction with the support. To elucidate its mechanism, Raman spectra of zinc phthalocyanine monolayers were studied. The analysis was based largely on the results of MNDO calculations. Calculated wavenumbers

Thermosetting Phthalocyanine Polymers

Science.gov (United States)

Fohlen, G.; Parker, J.; Achar, B.

1985-01-01

Group of phthalocyanine polymers resist thermal degradation. Polymers expected semiconducting. Principal applications probably in molded or laminated parts that have to withstand high temperatures. Polymers made from either of two classes of monomer: Bisphthalonitriles with imide linkages or Bisphthalonitriles with ester-imide linkages.

A core competency-based objective structured clinical examination (OSCE) can predict future resident performance.

Science.gov (United States)

Wallenstein, Joshua; Heron, Sheryl; Santen, Sally; Shayne, Philip; Ander, Douglas

2010-10-01

This study evaluated the ability of an objective structured clinical examination (OSCE) administered in the first month of residency to predict future resident performance in the Accreditation Council for Graduate Medical Education (ACGME) core competencies. Eighteen Postgraduate Year 1 (PGY-1) residents completed a five-station OSCE in the first month of postgraduate training. Performance was graded in each of the ACGME core competencies. At the end of 18 months of training, faculty evaluations of resident performance in the emergency department (ED) were used to calculate a cumulative clinical evaluation score for each core competency. The correlations between OSCE scores and clinical evaluation scores at 18 months were assessed on an overall level and in each core competency. There was a statistically significant correlation between overall OSCE scores and overall clinical evaluation scores (R = 0.48, p competencies of patient care (R = 0.49, p competencies. An early-residency OSCE has the ability to predict future postgraduate performance on a global level and in specific core competencies. Used appropriately, such information can be a valuable tool for program directors in monitoring residents' progress and providing more tailored guidance. © 2010 by the Society for Academic Emergency Medicine.

Russia coordinates new broadside against OSCE / Liz Fuller

Index Scriptorium Estoniae

Fuller, Liz

2004-01-01

SRÜ maade poolt 8. juulil 2004 Viinis tehtud avaldusest, mille kohaselt sekkub Euroopa Julgeoleku- ja Koostööorganisatsioon (OSCE) riikide siseasjadesse ning rakendab topeltstandardeid. Avaldusega ei ühinenud Gruusia ja Aserbaidžaan

Modification of an OSCE format to enhance patient continuity in a high-stakes assessment of clinical performance

Directory of Open Access Journals (Sweden)

Cuncic Cary

2011-05-01

Full Text Available Abstract Background Traditional Objective Structured Clinical Examinations (OSCEs are psychometrically sound but have the limitation of fragmenting complex clinical cases into brief stations. We describe a pilot study of a modified OSCE that attempts to balance a typical OSCE format with a semblance of a continuous, complex, patient case. Methods Two OSCE scenarios were developed. Each scenario involved a single standardized patient and was subdivided into three sequential 10 minute sections that assessed separate content areas and competencies. Twenty Canadian PGY-4 internal medicine trainees were assessed by trained examiner pairs during each OSCE scenario. Paired examiners rated participant performance independent of each other, on each section of each scenario using a validated global rating scale. Inter-rater reliabilities and Pearson correlations between ratings of the 3 sections of each scenario were calculated. A generalizability study was conducted. Participant and examiner satisfaction was surveyed. Results There was no main effect of section or scenario. Inter-rater reliability was acceptable. The g-coefficient was 0.68; four scenarios would achieve 0.80. Moderate correlations between sections of a scenario suggest a possible halo effect. The majority of examiners and participants felt that the modified OSCE provided a sense of patient continuity. Conclusions The modified OSCE provides another approach to the assessment of clinical performance. It attempts to balance the advantages of a traditional OSCE with a sense of patient continuity.

Spin-polarized scanning tunneling microscopy of magnetic nanostructures at the example of bcc-Co/Fe(110), Fe/Mo(110), and copper phthalocyanine/Fe(1110); Spinpolarisierte Rastertunnelmikroskopie magnetischer Nanostrukturen am Beispiel von bcc-Co/Fe(110), Fe/Mo(110) und Kupfer-Phthalocyanin/Fe(110)

Energy Technology Data Exchange (ETDEWEB)

Methfessel, Torsten

2010-12-09

This thesis provides an introduction into the technique of spin-polarized scanning tunnelling microscopy and spectroscopy as an experimental method for the investigation of magnetic nanostructures. Experimental results for the spin polarized electronic structure depending on the crystal structure of ultrathin Co layers, and depending on the direction of the magnetization for ultrathin Fe layers are presented. High-resolution measurements show the position-dependent spin polarization on a single copper-phthalocyanine molecule deposited on a ferromagnetic surface. Co was deposited by molecular beam epitaxy on the (110) surface of the bodycentered cubic metals Cr and Fe. In contrast to previous reports in the literature only two layers of Co can be stabilized in the body-centered cubic (bcc) structure. The bcc-Co films on the Fe(110) surface show no signs of epitaxial distortions. Thicker layers reconstruct into a closed-packed structure (hcp / fcc). The bcc structure increases the spin-polarization of Co to P=62 % in comparison to hcp-Co (P=45 %). The temperature-dependent spin-reorientation of ultrathin Fe/Mo(110) films was investigated by spin-polarized spectroscopy. A reorientation of the magnetic easy axis from the [110] direction along the surface normal to the in-plane [001] axis is observed at T (13.2{+-}0.5) K. This process can be identified as a discontinuous reorientation transition, revealing two simultaneous minima of the free energy in a certain temperature range. The electronic structure of mono- and double-layer Fe/Mo(110) shows a variation with the reorientation of the magnetic easy axis and with the direction of the magnetization. The investigation of the spin-polarized charge transport through a copper-phthalocyanine molecule on the Fe/Mo(110) surface provides an essential contribution to the understanding of spin-transport at the interface between metal and organic molecule. Due to the interaction with the surface of the metal the HOMO-LUMO energy

Evaluation of the OSC-TV iterative reconstruction algorithm for cone-beam optical CT.

Science.gov (United States)

Matenine, Dmitri; Mascolo-Fortin, Julia; Goussard, Yves; Després, Philippe

2015-11-01

The present work evaluates an iterative reconstruction approach, namely, the ordered subsets convex (OSC) algorithm with regularization via total variation (TV) minimization in the field of cone-beam optical computed tomography (optical CT). One of the uses of optical CT is gel-based 3D dosimetry for radiation therapy, where it is employed to map dose distributions in radiosensitive gels. Model-based iterative reconstruction may improve optical CT image quality and contribute to a wider use of optical CT in clinical gel dosimetry. This algorithm was evaluated using experimental data acquired by a cone-beam optical CT system, as well as complementary numerical simulations. A fast GPU implementation of OSC-TV was used to achieve reconstruction times comparable to those of conventional filtered backprojection. Images obtained via OSC-TV were compared with the corresponding filtered backprojections. Spatial resolution and uniformity phantoms were scanned and respective reconstructions were subject to evaluation of the modulation transfer function, image uniformity, and accuracy. The artifacts due to refraction and total signal loss from opaque objects were also studied. The cone-beam optical CT data reconstructions showed that OSC-TV outperforms filtered backprojection in terms of image quality, thanks to a model-based simulation of the photon attenuation process. It was shown to significantly improve the image spatial resolution and reduce image noise. The accuracy of the estimation of linear attenuation coefficients remained similar to that obtained via filtered backprojection. Certain image artifacts due to opaque objects were reduced. Nevertheless, the common artifact due to the gel container walls could not be eliminated. The use of iterative reconstruction improves cone-beam optical CT image quality in many ways. The comparisons between OSC-TV and filtered backprojection presented in this paper demonstrate that OSC-TV can potentially improve the rendering of

Exciplex mediated photoinduced electron transfer reactions of phthalocyanine-fullerene dyads.

Science.gov (United States)

Niemi, Marja; Tkachenko, Nikolai V; Efimov, Alexander; Lehtivuori, Heli; Ohkubo, Kei; Fukuzumi, Shunichi; Lemmetyinen, Helge

2008-07-31

Evidences of an intramolecular exciplex intermediate in a photoinduced electron transfer (ET) reaction of double-linked free-base and zinc phthalocyanine-C60 dyads were found. This was the first time for a dyad with phthalocyanine donor. Excitation of the phthalocyanine moiety of the dyads results in rapid ET from phthalocyanine to fullerene via an exciplex state in both polar and nonpolar solvents. Relaxation of the charge-separated (CS) state Pc(*+)-C60(*-) in a polar solvent occurs directly to the ground state in 30-70 ps. In a nonpolar solvent, roughly 20% of the molecules undergo transition from the CS state to phthalocyanine triplet state (3)Pc*-C60 before relaxation to the ground state. Formation of the CS state was confirmed with electron spin resonance measurements at low temperature in both polar and nonpolar solvent. Reaction schemes for the photoinduced ET reactions of the dyads were completed with rate constants obtained from the time-resolved absorption and emission measurements and with state energies obtained from the fluorescence, phosphorescence, and voltammetric measurements.

Forging Consensus for Atrocity Prevention: Assessing the Record of the OSCE

Directory of Open Access Journals (Sweden)

Matthew Levinger

2018-03-01

Full Text Available This essay examines the record of the Organization for Security and Cooperation in Europe (OSCE in fostering norms and collaborative practices for preventing mass atrocities in Eurasia. Comprising fifty-seven participating states “from Vancouver to Vladivostok,” the OSCE is the sole regional security organization spanning all of the members of NATO and the former Warsaw Pact. Its consensus-based approach to advancing “common and comprehensive security” has proved successful in preventing escalation or containing levels of violence in various conflicts in the Baltic states, Ukraine, Southeastern Europe, and the Caucasus. Since the late 1990s, however, rising geopolitical tensions between NATO and the Russian Federation have undermined the effectiveness of the OSCE’s conflict prevention initiatives. In order for the OSCE to play a more robust role in enhancing human security in Eurasia, it will need to find a path toward rebuilding the normative consensus between Russia and its Western participating states.

Formation of highly toxic hydrogen cyanide upon ruby laser irradiation of the tattoo pigment phthalocyanine blue

Science.gov (United States)

Schreiver, Ines; Hutzler, Christoph; Laux, Peter; Berlien, Hans-Peter; Luch, Andreas

2015-08-01

Since laser treatment of tattoos is the favored method for the removing of no longer wanted permanent skin paintings, analytical, biokinetics and toxicological data on the fragmentation pattern of commonly used pigments are urgently required for health safety reasons. Applying dynamic headspace—gas chromatography with mass spectrometric detection (DHS—GC/MS) and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC—ToF-MS), we identified 1,2-benzene dicarbonitrile, benzonitrile, benzene, and the poisonous gas hydrogen cyanide (HCN) as main fragmentation products emerging dose-dependently upon ruby laser irradiation of the popular blue pigment copper phthalocyanine in suspension. Skin cell viability was found to be significantly compromised at cyanide levels of ≥1 mM liberated during ruby laser irradiation of >1.5 mg/ml phthalocyanine blue. Further, for the first time we introduce pyrolysis-GC/MS as method suitable to simulate pigment fragmentation that may occur spontaneously or during laser removal of organic pigments in the living skin of tattooed people. According to the literature such regular tattoos hold up to 9 mg pigment/cm2 skin.

Development of Smart Phthalocyanine-based Photosensitizers for Photodynamic Therapy

Science.gov (United States)

Chow, Yun Sang

Phthalocyanines are versatile functional dyes that have shown great potential in cancer theranostics, especially in photodynamic therapy (PDT). This research work aims to develop "smart" phthalocyanine-based photosensitizers for targeted PDT. This thesis describes the synthesis, spectroscopic characterization, photophysical properties, and in vitro photodynamic activities of several series of carefully designed phthalocyanine-based photosensitizers. Chapter 1 presents an overview of PDT, including its historical development, photophysical mechanisms, and biological mechanisms. Various classes of photosensitizers are introduced with emphasis putting on phthalocyanines, which exhibit ideal characteristics of photosensitizers for PDT. In recent years, several approaches have been used to develop photosensitizers with higher tumor selectivity and minimal skin photosensitivity after PDT. Activatable photosensitizers can provide a "turn on" mechanism to offer an additional control of the specificity of treatment. Photosensitizers can also work cooperatively with the tumor-targeting groups or anticancer drugs so as to achieve targeted or dual therapy, which can enhance the efficacy of PDT. The novel approaches mentioned above have been widely used and combined to form multi-functional photosensitizing agents. These novel concepts and development of PDT are discussed and illustrated with relevant examples at the end of this chapter. To minimize the prolonged skin photosensitivity, photosensitizers that can only be activated by tumor-associated stimuli have been developed. Due to the abnormal metabolism in tumor tissues, their surface usually exhibits a lower pH compared to that of the normal tissues. Also, the pH difference between the intracellular and the physiological environment provides a pH-activation mechanism. Chapter 2 presents the synthesis and spectroscopic characterization of a pH-responsive zinc(II) phthalocyanine tetramer, in which the phthalocyanine units

Calibration of communication skills items in OSCE checklists according to the MAAS-Global.

Science.gov (United States)

Setyonugroho, Winny; Kropmans, Thomas; Kennedy, Kieran M; Stewart, Brian; van Dalen, Jan

2016-01-01

Communication skills (CS) are commonly assessed using 'communication items' in Objective Structured Clinical Examination (OSCE) station checklists. Our aim is to calibrate the communication component of OSCE station checklists according to the MAAS-Global which is a valid and reliable standard to assess CS in undergraduate medical education. Three raters independently compared 280 checklists from 4 disciplines contributing to the undergraduate year 4 OSCE against the 17 items of the MAAS-Global standard. G-theory was used to analyze the reliability of this calibration procedure. G-Kappa was 0.8. For two raters G-Kappa is 0.72 and it fell to 0.57 for one rater. 46% of the checklist items corresponded to section three of the MAAS-Global (i.e. medical content of the consultation), whilst 12% corresponded to section two (i.e. general CS), and 8.2% to section one (i.e. CS for each separate phase of the consultation). 34% of the items were not considered to be CS. A G-Kappa of 0.8 confirms a reliable and valid procedure for calibrating OSCE CS checklist items using the MAAS-Global. We strongly suggest that such a procedure is more widely employed to arrive at a stable (valid and reliable) judgment of the communication component in existing checklists for medical students' communication behaviours. It is possible to measure the 'true' caliber of CS in OSCE stations. Students' results are thereby comparable between and across stations, students and institutions. A reliable calibration procedure requires only two raters. Copyright © 2015. Published by Elsevier Ireland Ltd.

Photoinduced charge and energy transfer in phthalocyanine-functionalized gold nanoparticles

NARCIS (Netherlands)

Kotiaho, Anne; Lahtinen, Riikka; Efimov, Alexander; Metsberg, Hanna Kaisa; Sariola, Essi; Lehtivuori, Heli; Tkachenko, Nikolai V.; Lemmetyinen, Helge

2010-01-01

Photoinduced processes in phthalocyanine-functionalized gold nanoparticles (Pc-AuNPs) have been investigated by spectroscopic measurements. The metal-free phthalocyanines used have two linkers with thioacetate groups for bonding to the gold nanoparticle surface, and the attachment was achieved using

Phthalocyanines as sensitizers for photodynamic water disinfection

Energy Technology Data Exchange (ETDEWEB)

Kuznetsova, N.; Slivka, L.; Kaliya, O.; Lukyanets, E.; Negrimovsky, V.; Vorozhtsov, G. [Organic Intermediates and Dyes Inst., Moscow (Russian Federation); Nedachin, E.; Artemova, T.; Ivanova, L.; Lavrova, D. [A.N. Sysin Research Inst. of Human Ecology and Environmental Health of Russian Academy of Medical Sciences, Moscow (Russian Federation)

2003-07-01

New octapyridiniomethyl-substituted phthalocyanines of Al and Zn have been synthesized. These octacationic complexes are readily soluble in water, show monomeric behavior and sensitize formation of singlet oxygen efficiently. They are of high photodynamic potential in killing both Gram-negative and Gram-positive bacteria in contrast to negatively charged sulfonated derivatives, which are substantially less effective, particularly towards coliform bacteria in natural or sewage water. The present study confirms that cationic phthalocyanines represent a class of photosensitizing agents with an efficient antibacterial activity. (orig.)

Interactions of oversulfated chondroitin sulfate (OSCS) from different sources with unfractionated heparin.

Science.gov (United States)

Gray, Angel; Litinas, Evangelos; Jeske, Walter; Fareed, Jawed; Hoppensteadt, Debra

2012-01-01

In 2008, oversulfated chondroitin sulfate (OSCS) was identified as the main contaminant in recalled heparin. Oversulfated chondroitin sulfate can be prepared from bovine (B), porcine (P), shark (Sh), or skate (S) origin and may produce changes in the antithrombotic, bleeding, and hemodynamic profile of heparins. This study examines the interactions of various OSCSs on heparin in animal models of thrombosis and bleeding, as well as on the anticoagulant and antiprotease effects in in vitro assays. Mixtures of 70% unfractionated heparin (UFH) with 30% OSCS from different sources were tested. In the in vitro activated partial thromboplastin time (aPTT) assay, all contaminant mixtures showed a decrease in clotting times. In addition, a significant increase in bleeding time compared to the control (UFH/saline) was observed. In the thrombosis model, no significant differences were observed. The OSCSs significantly increased anti-Xa activity in ex vivo blood samples. These results indicate that various sources of OSCS affect the hemostatic properties of heparin.

Synthesis, photophysical and photochemical properties of zinc phthalocyanines bearing fluoro-functionalized substituents

International Nuclear Information System (INIS)

Aktaş, Ayşe; Pişkin, Mehmet; Durmuş, Mahmut; Bıyıklıoğlu, Zekeriya

2014-01-01

In this study, the synthesis of phthalonitrile derivatives bearing fluoro-functionalized groups and their peripherally-tetra substituted zinc phthalocyanine complexes were reported. The phthalonitrile derivatives 2a–5a were prepared by nucleophilic substitution of 4-nitrophthalonitrile with 2-[3-(trifluoromethyl)phenoxy]ethanol, 2-{2-[3-(trifluoromethyl) phenoxy]ethoxy}ethanol, 2-(2,3,5,6-tetrafluorophenoxy)ethanol, 2-[2-(2,3,5,6-tetrafluorophenoxy)ethoxy]ethanol, respectively. Zinc phthalocyanines bearing fluoro-functionalized groups (2b–5b) were obtained from the corresponding phthalonitrile derivatives. The newly synthesized phthalocyanines displayed good solubility in organic solvents such as chloroform (CHCl 3 ), dichloromethane (DCM), tetrahydrofuran (THF), toluene, dimethylformamide (DMF) and dimethylsulfoxide (DMSO). On the other hand, the singlet oxygen, photodegradation, fluorescence quantum yields and fluorescence lifetime of these complexes were determined in DMSO. The effects of the substitution with fluoro-functionalized groups on these parameters were also compared. -- Highlights: • Synthesis of peripherally substituted zinc phthalocyanines. • Photophysical and photochemical properties in DMSO for phthalocyanines. • Photodynamic therapy studies

Synthesis, photophysical and photochemical properties of zinc phthalocyanines bearing fluoro-functionalized substituents

Energy Technology Data Exchange (ETDEWEB)

Aktaş, Ayşe [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Pişkin, Mehmet [Marmara University, Faculty of Art and Science, Department of Chemistry, 34722 Kadikoy-Istanbul (Turkey); Durmuş, Mahmut [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze 41400, Kocaeli (Turkey); Bıyıklıoğlu, Zekeriya, E-mail: zekeriya_61@yahoo.com [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

2014-01-15

In this study, the synthesis of phthalonitrile derivatives bearing fluoro-functionalized groups and their peripherally-tetra substituted zinc phthalocyanine complexes were reported. The phthalonitrile derivatives 2a–5a were prepared by nucleophilic substitution of 4-nitrophthalonitrile with 2-[3-(trifluoromethyl)phenoxy]ethanol, 2-{2-[3-(trifluoromethyl) phenoxy]ethoxy}ethanol, 2-(2,3,5,6-tetrafluorophenoxy)ethanol, 2-[2-(2,3,5,6-tetrafluorophenoxy)ethoxy]ethanol, respectively. Zinc phthalocyanines bearing fluoro-functionalized groups (2b–5b) were obtained from the corresponding phthalonitrile derivatives. The newly synthesized phthalocyanines displayed good solubility in organic solvents such as chloroform (CHCl{sub 3}), dichloromethane (DCM), tetrahydrofuran (THF), toluene, dimethylformamide (DMF) and dimethylsulfoxide (DMSO). On the other hand, the singlet oxygen, photodegradation, fluorescence quantum yields and fluorescence lifetime of these complexes were determined in DMSO. The effects of the substitution with fluoro-functionalized groups on these parameters were also compared. -- Highlights: • Synthesis of peripherally substituted zinc phthalocyanines. • Photophysical and photochemical properties in DMSO for phthalocyanines. • Photodynamic therapy studies.

Ratiometric Fluorescent Detection of Pb2+ by FRET-Based Phthalocyanine-Porphyrin Dyads.

Science.gov (United States)

Zhang, Dongli; Zhu, Mengliang; Zhao, Luyang; Zhang, Jinghui; Wang, Kang; Qi, Dongdong; Zhou, Yang; Bian, Yongzhong; Jiang, Jianzhuang

2017-12-04

Sensitive and selective detection of Pb 2+ is a very worthwhile endeavor in terms of both human health and environmental protection, as the heavy metal is fairly ubiquitous and highly toxic. In this study, we designed phthalocyanine-porphyrin (Pc-Por) heterodyads, namely, H 2 Pc-α-ZnPor (1) and H 2 Pc-β-ZnPor (2), by connecting a zinc(II) porphyrin moiety to the nonperipheral (α) or peripheral (β) position of a metal-free phthalocyanine moiety. Upon excitation at the porphyrin Soret region (420 nm), both of the dyads exhibited not only a porphyrin emission (605 nm) but also a phthalocyanine emission (ca. 700 nm), indicating the occurrence of intramolecular fluorescence resonance energy transfer (FRET) processes from the porphyrin donor to the phthalocyanine acceptor. The dyads can selectively bind Pb 2+ in the phthalocyanine core leading to a red shift of the phthalocyanine absorption and thus a decrease of spectral overlap between the porphyrin emission and phthalocyanine absorption, which in turn suppresses the intramolecular FRET. In addition, the binding of Pb 2+ can highly quench the emission of phthalocyanine by heavy-metal ion effects. The synergistic coupled functions endow the dyads with remarkable ratiometric fluorescent responses at two distinct wavelengths (F 605 /F 703 for 1 and F 605 /F 700 for 2). The emission intensity ratio increased as a linear function to the concentration of Pb 2+ in the range of 0-4.0 μM, whereas the detection limits were determined to be 3.4 × 10 -9 and 2.2 × 10 -8 M for 1 and 2, respectively. Furthermore, by comparative study of 1 and 2, the effects of distance and relative orientation between Pc and ZnPor fluorophores on the FRET efficiency and sensing performance were highlighted, which is helpful for further optimizing such FRET systems.

Assessing the Organizational Social Context (OSC) of Child Welfare Systems: Implications for Research and Practice

Science.gov (United States)

Glisson, Charles; Green, Philip; Williams, Nathaniel J.

2012-01-01

Objective: The study: (1) provides the first assessment of the a "priori" measurement model and psychometric properties of the Organizational Social Context (OSC) measurement system in a US nationwide probability sample of child welfare systems; (2) illustrates the use of the OSC in constructing norm-based organizational culture and climate…

Photophysical properties of a novel axially substituted tetra-α-(pentyloxy) Titanium(IV) Phthalocyanine - Hematoxylin

Science.gov (United States)

Jiang, Yufeng; Lv, Huafei; Yu, Xinxin; Pan, Sujuan; Zhang, Tiantian; Huang, Yide; Wang, Yuhua; Xie, Shusen; Yang, Hongqin; Peng, Yiru

2017-06-01

Metal phthalocyanines (MPcs) are a very important class of widespread application compounds. They are not only used as dyes but also used as catalysts, data storage, electron charge carriers in photocopiers, photoconductors in chemical sensors, and photo-antenna devices in photosysthesis, photovoltaic cells. A particular application of Pcs is that it was used as a photosensitizers (PS) for treatment of certain cancer by photodynamic therapy of cancer and non-cancer diseases. However, the molecular aggregation of phthalocyanines, which is an intrinsic property of these large π-π conjugated systems, provides an efficient non-radioactive energy relaxation pathway, thereby shortening the excited state lifetimes, and reducing the photosensitizing and target efficiency. To overcome these problems, the introduction of axial ligands to phthalocyanine can prevent the formation of aggregation to some extend. In this paper, hematoxylin axially substituted tetra-α-(pentoxy) titanium (IV) phthalocyanine (TiPc(OC5H11)4-Hematoxylin) were characterized by elemental analysis, IR, 1H NMR, UV-Vis, fluorescence spectra. No obviously Q band change was observed after the hematoxylin was substituted at the peripheral position of substituted phthalocyanine ring. Because of the rigidity structure of the hematoxylin, the fluorescence intensity of hematoxylin peripheral substituted phthalocyanine decreased compared with free substituted phthalocyanines. The fluorescence lifetimes of axially substituted phthalocyanine was fitted to be 3.613 ns. This compound may be considered as a promising photosensitizer for PDT.

Some features of the molecular assembly of copper porphyrazines

International Nuclear Information System (INIS)

Valkova, L.; Borovkov, N.; Kopranenkov, V.; Pisani, M.; Bossi, M.; Rustichelli, F.

2002-01-01

Floating layers and Langmuir-Blodgett (LB) films of copper porphyrazine (CuPaz) and its tetra-tert-butyl-substituted homologue (CuPaz') are studied. Contrary to phthalocyanines, the monolayer phase in the porphyrazine layers is metastable and transforms directly into the tetralayer one under moderate compression. In diffraction patterns and electronic spectra of the LB films, supramolecular peaks indicating collectivizing of the molecular electron density in direction perpendicular to the main axis of the macrocycle are found. The data obtained indicate the prismatic 3-D supermolecule to be the simplest structural unit of the porphyrazine assembly

Theoretical Study on the Rational Design of Cyano-Substituted P3HT Materials for OSCs

DEFF Research Database (Denmark)

Qiu, Meng; Brandt, Rasmus Guldbæk; Niu, Yingli

2015-01-01

Calculations have been made regarding the strong electron-withdrawing cyano (-CN) group, which was introduced onto the backbone of poly(3-hexylthiophene) (P3HT), as an effective way to improve the parameters essential for the photovoltaic performance of organic solar cells (OSCs). The substitution...... useful information for better design strategy for OSCs....

Photoinduced electron transfer between the dendritic zinc phthalocyanines and anthraquinone

Science.gov (United States)

Chen, Kuizhi; Wen, Junri; Liu, Jiangsheng; Chen, Zhenzhen; Pan, Sujuan; Huang, Zheng; Peng, Yiru

2015-03-01

The intermolecular electron transfer between the novel dendritic zinc (II) phthalocyanines (G1-DPcB and G2-DPcB) and anthraquinone (AQ) was studied by steady-state fluorescence and UV/Vis absorption spectroscopic methods. The effect of dendron generation on intermolecular electron transfer was investigated. The results showed that the fluorescence emission of these dendritic phthalocyanines could be greatly quenched by AQ upon excitation at 610 nm. The Stern- Volmer constant (KSV) of electron transfer was decreased with increasing the dendron generations. Our study suggested that these novel dendritic phthalocyanines were effective new electron donors and transmission complexes and could be used as a potential artifical photosysthesis system.

Photoelectric characteristics of lead phthalocyanine/titanium oxide structures

CERN Document Server

Ray, A K; Hodgson, S N B

2003-01-01

A study has been carried out into the conduction, charge transfer/electron injection and photovoltaic conversion properties of TiO sub 2 -lead phthalocyanine (PbPc) heterojunctions. The results indicate that although the heterojunction area, and hence overall conversion efficiency, was low for the planar device structures used in the investigation, electron injection and effective charge separation across the dye-TiO sub 2 interface was achieved, with open circuit voltages in the region of 0.3 V. The conversion efficiency was found to be a function of the thickness of the phthalocyanine layer, increasing by a factor of more than 30 times as the thickness of the dye layer was reduced from 500 to 100 nm. The results suggest that under appropriate deposition conditions, to ensure effective coating of the inorganic phase, such phthalocyanine dyes may offer potential for use in dye sensitized photovoltaic cells.

Continuous wasteless ecologically safe technology of propylenecarbonate production in presence of phthalocyanine catalysts

Science.gov (United States)

Afanasiev, Vladimir Vasilievich [Moscow, RU; Zefirov, Nikolai Serafimovich [Moscow, RU; Zalepugin, Dmitry Yurievich [Moscow, RU; Polyakov, Victor Stanislavovich [Moscow, RU; Tilkunova, Nataliya Alexandrovna [Moscow, RU; Tomilova, Larisa Godvigovna [Moscow, RU

2009-09-08

A continuous method of producing propylenecarbonate includes carboxylation of propylene oxide with carbon dioxide in presence of phthalocyanine catalyst on an inert carrier, using as the phthalocyanine catalyst at least one catalyst selected from the group consisting of not-substituted, methyl, ethyl, butyl, and tret butyl-substituted phthalocyanines of metals, including those containing counterions, and using as the carrier a hydrophobic carrier.

Permanganate-assisted removal of PCR inhibitors during the DNA Chelex extraction from stained denim samples.

Science.gov (United States)

Pîrlea, Sorina; Puiu, Mihaela; Răducan, Adina; Oancea, Dumitru

2017-03-01

In this study, it was demonstrated that the DNA Chelex extraction combined with the permanganate assisted-oxidation is highly efficient in removing the PCR inhibitors often found in clothing materials, such as phthalocyanine. The extraction assays were conducted in saliva, blood and epithelial cells samples mixed with three oxidation-resistant dye copper(II) α-phthalocyanine, copper(II) β-phthalocyanine and tetrasulfonated copper(II) β-phthalocyanine. After DNA amplification, all samples were able to provide full DNA profiles. The permanganate/Chelex system was tested further on denim-stained samples and displayed the same ability to remove the PCR inhibitors from the commercial textile materials.

Assessing the Organizational Social Context (OSC) of child welfare systems: implications for research and practice.

Science.gov (United States)

Glisson, Charles; Green, Philip; Williams, Nathaniel J

2012-09-01

The study: (1) provides the first assessment of the a priori measurement model and psychometric properties of the Organizational Social Context (OSC) measurement system in a US nationwide probability sample of child welfare systems; (2) illustrates the use of the OSC in constructing norm-based organizational culture and climate profiles for child welfare systems; and (3) estimates the association of child welfare system-level organizational culture and climate profiles with individual caseworker-level job satisfaction and organizational commitment. The study applies confirmatory factor analysis (CFA) and hierarchical linear models (HLM) analysis to a US nationwide sample of 1,740 caseworkers from 81 child welfare systems participating in the second National Survey of Child and Adolescent Wellbeing (NSCAW II). The participating child welfare systems were selected using a national probability procedure reflecting the number of children served by child welfare systems nationwide. The a priori OSC measurement model is confirmed in this nationwide sample of child welfare systems. In addition, caseworker responses to the OSC scales generate acceptable to high scale reliabilities, moderate to high within-system agreement, and significant between-system differences. Caseworkers in the child welfare systems with the best organizational culture and climate profiles report higher levels of job satisfaction and organizational commitment. Organizational climates characterized by high engagement and functionality, and organizational cultures characterized by low rigidity are associated with the most positive work attitudes. The OSC is the first valid and reliable measure of organizational culture and climate with US national norms for child welfare systems. The OSC provides a useful measure of Organizational Social Context for child welfare service improvement and implementation research efforts which include a focus on child welfare system culture and climate. Copyright © 2012

OSCEs for undergraduate clinical examination in orthopaedics: inter ...

African Journals Online (AJOL)

... D (Group 2) was 8.625. The p-value was 0.001148 (95% confidence interval). Conclusion: There was statistically significant inter-examiner variability. We recommend that for all OSCE exams, examiners be paired with a deliberate attempt to pair a “Hawk” with a “Dove”. Statistical correction of biases is also recommended.

Phthalocyanine doping to improve critical current densities in MgB2 tapes

International Nuclear Information System (INIS)

Zhang Xianping; Ma Yanwei; Wang Dongliang; Gao Zhaoshun; Wang Lei; Qi Yanpeng; Awaji, Satoshi; Watanabe, Kazuo; Mossang, Eric

2009-01-01

Phthalocyanine-doped MgB 2 tapes were prepared by the in situ powder-in-tube method. The relationships between the critical current properties, crystallinity and microstructure were studied as a function of the phthalocyanine doping level. It is found that both H irr and H c2 were improved when MgB 2 samples were doped with phthalocyanine, which are mainly attributed to the effective carbon substitution and enhanced flux pinning strength caused by very fine grain sizes. Furthermore, compared to pure samples, the MgO content remained almost unchanged in all doped tapes, which is very beneficial to having better grain connectivity in MgB 2 . Significantly improved J c was obtained in the phthalocyanine-doped MgB 2 tapes, especially under high magnetic fields.

Enhancement in photovoltaic performance of phthalocyanine-sensitized solar cells by attapulgite nanoparticles

International Nuclear Information System (INIS)

Jin Ling; Chen Dajun

2012-01-01

Highlights: ► Dye-sensitized solar cells sensitized by zinc octacarboxylic phthalocyanine. ► Attapulgite nanoparticles have been used to suppress phthalocyanine aggregation. ► Adding attapulgite improves the photovoltaic performance of the dye-sensitized solar cells. - Abstract: Attapulgite nanoparticles were used to improve photovoltaic performance of phthalocyanine-sensitized solar cells. The effects of attapulgite on the devices were investigated in details. Adding of attapulgite into TiO 2 electrodes not only reduced the adsorption of zinc octacarboxylic phthalocyanine but also prevented phthalocyanine aggregation effect, which greatly improved photovoltaic performance of the dye-sensitized solar cell. The solar cell with 10 mg attapulgite nanoparticles dispersed in the dye solution exhibited nearly three times larger photoelectric conversion efficiency under simulated AM 1.5 G irradiation (100 mW cm −2 ) when compared to the pure dye, which was further characterized by the electrochemical impedance spectroscopy (EIS). The EIS studies showed that attapulgite decreased the charge-transfer resistances at the TiO 2 /dye/electrolyte interface, which can promote electron transport.

Photochemical and Photophysical Properties of Phthalocyanines Modified with Optically Active Alcohols

Directory of Open Access Journals (Sweden)

Aline A. Ramos

2015-07-01

Full Text Available Three phthalocyanine derivatives were synthesized and characterized: one modified with a racemic mixture of 1-(4-bromophenylethanol and two other macrocycles modified with each one of the enantioenriched isomers (R-1-(4-bromophenylethanol and (S-1-(4-bromophenylethanol. The compounds were characterized by 1H-NMR spectroscopy, mass spectrometry, UV-Vis absorption, and excitation and emission spectra. Additionally, partition coefficient values and the quantum yield of the generation of oxygen reactive species were determined. Interestingly, the phthalocyanine containing a (R-1-(4-bromophenylethoxy moiety showed higher quantum yield of reactive oxygen species generation than other compounds under the same conditions. In addition, the obtained fluorescence microscopy and cell viability results have shown that these phthalocyanines have different interactions with mammary MCF-7 cells. Therefore, our results indicate that the photochemical and biological properties of phthalocyanines with chiral ligands should be evaluated separately for each enantiomeric species.

Interface properties of Fe/MgO/Cu-phthalocyanine metal-insulator-organic semiconductor structures

International Nuclear Information System (INIS)

Lee, Nyunjong; Bae, Yujeong; Kim, Taehee; Ito, Eisuke; Hara, Masahiko

2014-01-01

Hybrid interface structures consisting of organic copper-phthalocyanine (CuPc) and ferromagnetic metal Fe(001) with and without a MgO(001) cover were investigated by using surface sensitive techniques of X-ray photoemission spectroscopy and ultraviolet photoemission spectroscopy. A systematic study of the energy level alignment at the interfaces was carried out. For the hybrid interfaces considered here, our results indicate that the insertion of an artificially-grown ultra-thin oxide layer MgO(001) can prevent Femi level pinning and induce a rather large interface dipole, thereby resulting in remarkable CuPc Fermi level shifts when the thickness of the CuPc film is less than 3 nm. This study provides a better understanding of spin filtering in MgO-based organic spin devices and a new way to alter the interface electronic structure of metal/organic semiconductor hybrid systems.

Phthalocyanines in batteries and supercapacitors

CSIR Research Space (South Africa)

Oni, J

2012-08-01

Full Text Available of their lower cost. This review article looks through a very narrow window of the applications of phthalocyanines in batteries and supercapacitors as a means of improving the qualities such as cycle property, energy density, capacity, open circuit voltage, etc...

Use of the OSCE to Evaluate Brief Communication Skills Training for Dental Students

Science.gov (United States)

Cannick, Gabrielle F.; Horowitz, Alice M.; Garr, David R.; Reed, Susan G.; Neville, Brad W.; Day, Terry A.; Woolson, Robert F.; Lackland, Daniel T.

2009-01-01

Although communications competency is recommended by the American Dental Education Association, only a few (n=5) dental schools report evaluating students’ skills using a competency examination for communication. This study used an objective structured clinical examination (OSCE) to evaluate dental students’ competency in interpersonal and tobacco cessation communication skills. All students were evaluated on their interpersonal communication skills at baseline and at six months post-OSCE by standardized patients and on their tobacco cessation communication skills by two independent raters. First- and second-year dental students (n=104) were randomized to a control or intervention group. One month after the baseline OSCE, students in the intervention group participated in a two-hour training session in which faculty members communicated with a standardized patient during a head and neck examination and counseled the patient about tobacco cessation. There were no statistically significant differences from baseline to post-test between the intervention and control group students as measured by the OSCE. However, among first-year students, both the intervention (n=23) and control (n=21) groups significantly increased in tobacco cessation communication scores. Second-year students in both intervention (n=24) and control (n=28) groups declined in interpersonal communication skills from baseline to post-test. Overall, this one-shot intervention was not successful, and results suggest that a comprehensive communication skills training course may be more beneficial than a single, brief training session for improving dental students’ communication skills. PMID:17761627

Realisation and study of poly-phthalocyanine thin films grafted on solid substrate

International Nuclear Information System (INIS)

Huc, Vincent

1999-01-01

The aim of this work is to develop thin films of phthalocyanines covalently grafted to solid substrates. These thin films are formed of successive monomolecular layers of macrocycles, deposited on the substrate by a 'Merrifield' sequential method. These phthalocyanines have in their centre a metallic ion (such as ruthenium) which ensures the bonding of phthalocyanines on the substrate and the assembling of monolayers consecutive together. The deposition of these monolayers is provided by a succession of two spontaneous exchange ligands reactions between the labile groups L initially bound to ruthenium and to those present on the substrate (preliminary functionalized). The repetition of these two steps allows to consider the controlled formation of phthalocyanines multilayers by self-assembling. The main substrates used are the silicon oxide and the gold. Their different characteristics have imposed the development of separate functionalization and characterization methods. The results obtained with these two substrates are separately described. A second method of construction of successive monolayers of phthalocyanines is described involving a chemical coupling between an amine function carried out by the substrate and an aldehyde function present on the ligands bound on ruthenium. (author) [fr

Localization Study of Co-Phthalocyanines in Cells by Raman Micro(spectro)scopy

NARCIS (Netherlands)

Arzhantsev, S.Y.; Arzhantsev, S.Y.; Chikishev, A.Y.; Chikishev, A.Y.; Koroteev, N.I.; Greve, Jan; Otto, Cornelis; Sijtsema, N.M.

1999-01-01

An investigation of intracellular localization of Co-phthalocyanines is reported. The Raman images of K562 cells stained with phthalocyanine were acquired. To understand the peculiarities of the Raman images, measurements were performed at different z-axis positions. The intracellular concentration

Localization study of Co-phthalocyanines in cells by Raman micro(spectro)scopy

NARCIS (Netherlands)

Arzhantsev, S Y; Chikishev, A Y; Koroteev, N I; Greve, J; Otto, C; Sijtsema, N M

An investigation of intracellular localization of Co-phthalocyanines is reported. The Raman images of K562 cells stained with phthalocyanine were acquired. To understand the peculiarities of the Raman images, measurements were performed at different z-axis positions. The intracellular concentration

Synthesis of phthalocyanine conjugates with gold nanoparticles and liposomes for photodynamic therapy

CSIR Research Space (South Africa)

Nombona, N

2012-02-01

Full Text Available -damage of cancer cells. The production of reactive oxygen species (ROS) and phototoxicity of the photosensitizer were assessed. Healthy fibroblast cells and breast cancer (MCF-7) cells were treated with either free phthalocyanine or phthalocyanine bound to either...

Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE)--A Systematic Review of Rating Scales.

Science.gov (United States)

Cömert, Musa; Zill, Jördis Maria; Christalle, Eva; Dirmaier, Jörg; Härter, Martin; Scholl, Isabelle

2016-01-01

Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE) has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students' communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales. We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed), reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues. Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate. Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed in order to yield psychometrically

Interfacial Engineering of Perovskite Solar Cells by Employing a Hydrophobic Copper Phthalocyanine Derivative as Hole-Transporting Material with Improved Performance and Stability.

Science.gov (United States)

Jiang, Xiaoqing; Yu, Ze; Lai, Jianbo; Zhang, Yuchen; Hu, Maowei; Lei, Ning; Wang, Dongping; Yang, Xichuan; Sun, Licheng

2017-04-22

In high-performance perovskite solar cells (PSCs), hole-transporting materials (HTMs) play an important role in extracting and transporting the photo-generated holes from the perovskite absorber to the cathode, thus reducing unwanted recombination losses and enhancing the photovoltaic performance. Herein, solution-processable tetra-4-(bis(4-tert-butylphenyl)amino)phenoxy-substituted copper phthalocyanine (CuPc-OTPAtBu) was synthesized and explored as a HTM in PSCs. The optical, electrochemical, and thermal properties were fully characterized for this organic metal complex. The photovoltaic performance of PSCs employing this CuPc derivative as a HTM was further investigated, in combination with a mixed-ion perovskite as a light absorber and a low-cost vacuum-free carbon as cathode. The optimized devices [doped with 6 % (w/w) tetrafluoro-tetracyano-quinodimethane (F4TCNQ)] showed a decent power conversion efficiency of 15.0 %, with an open-circuit voltage of 1.01 V, a short-circuit current density of 21.9 mA cm -2 , and a fill factor of 0.68. Notably, the PSC devices studied also exhibited excellent long-term durability under ambient condition for 720 h, mainly owing to the introduction of the hydrophobic HTM interlayer, which prevents moisture penetration into the perovskite film. The present work emphasizes that solution-processable CuPc holds a great promise as a class of alternative HTMs that can be further explored for efficient and stable PSCs in the future. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Subjektive Kompetenzeinschätzung von Studierenden und ihre Leistung im OSCE [Student´s self-assessment of clinical competence and objective clinical performance in OSCE evaluation

Directory of Open Access Journals (Sweden)

Jünger, Jana

2006-08-01

Full Text Available [english] Overestimating one's clinical competence can be dangerous to patient's safety. Therefore the goal of this study was to identify students with high confidence in their own clinical competence but low performance in objective assessment. 171 students in the 14 week course in internal medicine completed the clinical skills-related self-assessment expectations (SE and were tested in a 12 station OSCE. Both measures were obtained within three days. In total we identified 16% of students who overestimated their performance in clinical skills compared to their OSCE-results. Male students significantly more oversestimated their clinical compltence (31% than female students. One possible cause may be the lack of corrective experiences during clinical traineeship leading to the misconception of own performance. Further validation and the integration of a counselling program for these students seem necessary. [german] Die Selbstüberschätzung ärztlicher Kompetenzen kann weitereichende Konsequenzen für die Patientensicherheit haben. Aus diesem Grunde initiierten wir eine Studie zur Identifizierung von Studierenden, die ihre klinische Kompetenz als sehr gut einschätzen, jedoch eine unzufriedenstellende objektive klinisch-praktische Performanz aufweisen. 171 Studierende des 14-wöchigen Blockes Innere Medizin an der Medizinischen Universitätsklinik Heidelberg füllten einen Selbsteinschätzungsfragebogen zur klinischen Kompetenz aus und wurden in einem 12-Stationen OSCE evaluiert. Beide Messungen wurden innerhalb von drei Tagen vollzogen. Insgesamt konnten 16% der Studierenden identifiziert werden, die sich verglichen mit den OSCE-Ergebnissen, bezüglich ihrer klinisch-praktischen Fertigkeit selbst überschätzen. Dabei überschätzen sich signifikant mehr männliche (31% als weibliche (8% Studierende. Eine mögliche Erklärung für den Sachverhalt der studentischen Fehleinschätzung klinischer Kompetenzen könnte in fehlenden korrigierenden R�

Tetra-methyl substituted copper (II) phthalocyanine as a hole injection enhancer in organic light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Wang, Yu-Long; Xu, Jia-Ju; Lin, Yi-Wei; Chen, Qian; Shan, Hai-Quan; Xu, Zong-Xiang, E-mail: xu.zx@sustc.edu.cn, E-mail: val.roy@cityu.edu.hk [Department of Chemistry, South University of Science and Technology of China, Shenzhen, Guangdong, P. R. China, 518055 (China); Yan, Yan; Roy, V. A. L., E-mail: xu.zx@sustc.edu.cn, E-mail: val.roy@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (Hong Kong)

2015-10-15

We have enhanced hole injection and lifetime in organic light-emitting diodes (OLEDs) by incorporating the isomeric metal phthalocyanine, CuMePc, as a hole injection enhancer. The OLED devices containing CuMePc as a hole injection layer (HIL) exhibited higher luminous efficiency and operational lifetime than those using a CuPc layer and without a HIL. The effect of CuMePc thickness on device performance was investigated. Atomic force microscope (AFM) studies revealed that the thin films were smooth and uniform because the mixture of CuMePc isomers depressed crystallization within the layer. This may have caused the observed enhanced hole injection, indicating that CuMePc is a promising HIL material for highly efficient OLEDs.

Tetra-methyl substituted copper (II phthalocyanine as a hole injection enhancer in organic light-emitting diodes

Directory of Open Access Journals (Sweden)

Yu-Long Wang

2015-10-01

Full Text Available We have enhanced hole injection and lifetime in organic light-emitting diodes (OLEDs by incorporating the isomeric metal phthalocyanine, CuMePc, as a hole injection enhancer. The OLED devices containing CuMePc as a hole injection layer (HIL exhibited higher luminous efficiency and operational lifetime than those using a CuPc layer and without a HIL. The effect of CuMePc thickness on device performance was investigated. Atomic force microscope (AFM studies revealed that the thin films were smooth and uniform because the mixture of CuMePc isomers depressed crystallization within the layer. This may have caused the observed enhanced hole injection, indicating that CuMePc is a promising HIL material for highly efficient OLEDs.

Recent Studies in Phthalocyanine Chemistry.

Science.gov (United States)

1986-07-01

desulfurisation ) etc. Many of the uses cited In the preceding sentence involve a redox process in which two or more electrons are exchanged per reaction...phthalocyanine as a catalyst for desulfurisation of residues, effluents etc 144]. Acknowledgmnts We ars Indebted to the Natural Sciences and Engineering

Development, implementation, and evaluation of an integrated multidisciplinary Objective Structured Clinical Examination (OSCE) in primary health care settings within limited resources.

Science.gov (United States)

Abdelaziz, Adel; Hany, Mohamed; Atwa, Hani; Talaat, Wagdy; Hosny, Somaya

2016-01-01

In ordinary circumstances, objective structured clinical examination (OSCE) is a resource-intensive assessment method. In case of developing and implementing multidisciplinary OSCE, there is no doubt that the cost will be greater. Through this study a research project was conducted to develop, implement and evaluate a multidisciplinary OSCE model within limited resources. This research project went through the steps of blueprinting, station writing, resources reallocation, implementation and finally evaluation. The developed model was implemented in the Primary Health Care (PHC) program which is one of the pillars of the Community-Based undergraduate curriculum of the Faculty of Medicine, Suez Canal University (FOM-SCU). Data for evaluation of the implemented OSCE model were derived from two resources. First, feedback of the students and assessors through self-administered questionnaires was obtained. Second, evaluation of the OSCE psychometrics was done. The deliverables of this research project included a set of validated integrated multi-disciplinary and low cost OSCE stations with an estimated reliability index of 0.6. After having this experience, we have a critical mass of faculty members trained on blueprinting and station writing and a group of trained assessors, facilitators and role players. Also there is a state of awareness among students on how to proceed in this type of OSCE which renders future implementation more feasible.

A fast 4D cone beam CT reconstruction method based on the OSC-TV algorithm.

Science.gov (United States)

Mascolo-Fortin, Julia; Matenine, Dmitri; Archambault, Louis; Després, Philippe

2018-01-01

Four-dimensional cone beam computed tomography allows for temporally resolved imaging with useful applications in radiotherapy, but raises particular challenges in terms of image quality and computation time. The purpose of this work is to develop a fast and accurate 4D algorithm by adapting a GPU-accelerated ordered subsets convex algorithm (OSC), combined with the total variation minimization regularization technique (TV). Different initialization schemes were studied to adapt the OSC-TV algorithm to 4D reconstruction: each respiratory phase was initialized either with a 3D reconstruction or a blank image. Reconstruction algorithms were tested on a dynamic numerical phantom and on a clinical dataset. 4D iterations were implemented for a cluster of 8 GPUs. All developed methods allowed for an adequate visualization of the respiratory movement and compared favorably to the McKinnon-Bates and adaptive steepest descent projection onto convex sets algorithms, while the 4D reconstructions initialized from a prior 3D reconstruction led to better overall image quality. The most suitable adaptation of OSC-TV to 4D CBCT was found to be a combination of a prior FDK reconstruction and a 4D OSC-TV reconstruction with a reconstruction time of 4.5 minutes. This relatively short reconstruction time could facilitate a clinical use.

M-OSCE as a method to measure dental hygiene students' critical thinking: a pilot study.

Science.gov (United States)

McComas, Martha J; Wright, Rebecca A; Mann, Nancy K; Cooper, Mary D; Jacks, Mary E

2013-04-01

Educators in all academic disciplines have been encouraged to utilize assessment strategies to evaluate students' critical thinking. The purpose of this study was to assess the viability of the modified objective structured clinical examination (m-OSCE) to evaluate critical thinking in dental hygiene education. This evaluation utilized a convenience sample of senior dental hygiene students. Students participated in the m-OSCE in which portions of a patient case were revealed at four stations. The exam consisted of multiple-choice questions intended to measure students' ability to utilize critical thinking skills. Additionally, there was one fill-in-the-blank question and a treatment plan that was completed at the fifth station. The results of this study revealed that the m-OSCE did not reliably measure dental hygiene students' critical thinking. Statistical analysis found no satisfactory reliability within the multiple-choice questions and moderately reliable results within the treatment planning portion of the examination. In addition, the item analysis found gaps in students' abilities to transfer clinical evidence/data to basic biomedical knowledge as demonstrated through the multiple-choice questioning results. This outcome warrants further investigation of the utility of the m-OSCE, with a focus on modifications to the evaluation questions, grading rubric, and patient case.

Synthesis, spectral and photophysical properties of novel phthalocyanines bearing bulky phenantroxy moiety

International Nuclear Information System (INIS)

Erdogmuş, Ali; Lütfi Ugur, Ahmet; Memişoglu, Abdussamed; Erden, İbrahim

2013-01-01

The synthesis, characterization, spectral and photophysical properties of soluble 9-Phenanthroxy substituted oxo-titanium (IV), zinc, magnesium and nickel phthalocyanines (1a, 1b, 1c and 1d) are reported for the first time. The new compounds have been characterized by elemental analysis, FT-IR, 1 H–NMR spectroscopy, electronic spectroscopy and mass spectra. General trends are described for spectral, fluorescence properties and fluorescence quantum yields of these compounds in dimethylsulfoxide (DMSO) and toluene. All phthalocyanine complexes (1a to 1d) exhibited excellent solubility in organic solvents such as dichloromethane, chloroform, THF, toluene, DMF and DMSO. - Highlights: ► New metallophthalocyanines (1a–1d) were synthesized. ► These new phthalocyanine derivatives show the enhanced solubility in organic solvents. ► The spectral and photophysical properties of TiO(IV), zinc (II) and Mg(II) phthalocyanine (1a–1c) are investigated in DMSO and toluene. ► Ground state electronic absorption and fluorescence spectra.

Nurse educators’ perceptions of OSCE as a clinical evaluation method

Directory of Open Access Journals (Sweden)

MM Chabeli

2001-09-01

Full Text Available The South African Qualifications Authority, and the South African Nursing Council are in pursuit of quality nursing education to enable the learners to practise as independent and autonomous practitioners. The educational programme should focus on the facilitation of critical and reflective thinking skills that will help the learner to make rational decisions and solve problems. A way of achieving this level of functioning is the use of assessment and evaluation methods that measure the learners’ clinical competence holistically. This article is focused on the perceptions of twenty nurse educators, purposively selected from three Nursing Colleges affiliated to a university in Gauteng, regarding the use of OSCE (Objective Structured Clinical Examination as a clinical evaluation method within a qualitative and descriptive research strategy. Three focus group interviews were conducted in different sessions. A descriptive content analysis was used. Trustworthiness was ensured by using Lincoln and Guba’s model (1985. The results revealed both positive and negative aspects of OSCE as a clinical evaluation method with regard to: administrative aspects; evaluators; learners; procedures/instruments and evaluation. The conclusion drawn from the related findings is that OSCE does not measure the learners’ clinical competence holistically. It is therefore recommended that the identified negative perception be taken as challenges faced by nurse educators and that the positive aspects be strengthened. One way of meeting these recommendations is the use of varied alternative methods for clinical assessment and evaluation that focus on the holistic measurement of the learners’ clinical competence.

Charge transfer from and to manganese phthalocyanine: bulk materials and interfaces

Directory of Open Access Journals (Sweden)

Florian Rückerl

2017-08-01

Full Text Available Manganese phthalocyanine (MnPc is a member of the family of transition-metal phthalocyanines, which combines interesting electronic behavior in the fields of organic and molecular electronics with local magnetic moments. MnPc is characterized by hybrid states between the Mn 3d orbitals and the π orbitals of the ligand very close to the Fermi level. This causes particular physical properties, different from those of the other phthalocyanines, such as a rather small ionization potential, a small band gap and a large electron affinity. These can be exploited to prepare particular compounds and interfaces with appropriate partners, which are characterized by a charge transfer from or to MnPc. We summarize recent spectroscopic and theoretical results that have been achieved in this regard.

Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE) - A Systematic Review of Rating Scales

Science.gov (United States)

Cömert, Musa; Zill, Jördis Maria; Christalle, Eva; Dirmaier, Jörg; Härter, Martin; Scholl, Isabelle

2016-01-01

Background Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE) has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students’ communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales. Methods We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed), reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues. Results Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate. Discussion Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed

Soluble substituted phthalocyanines for OFET applications

Czech Academy of Sciences Publication Activity Database

Chaidogiannos, G.; Petraki, F.; Glezos, N.; Kennou, S.; Nešpůrek, Stanislav

2008-01-01

Roč. 152, - (2008), s. 105-108 ISSN 0921-5107. [International Workshop on Nanosciences and Nanotechnologies. Thessaloniki, 16.08.2007-18.07.2007] Institutional research plan: CEZ:AV0Z40500505 Keywords : organic electronic transistors * phthalocyanines Subject RIV: CD - Macromolecular Chemistry

The first OSCE; does students' experience of performing in public affect their results?

Science.gov (United States)

Chan, Michael; Bax, Nigel; Woodley, Caroline; Jennings, Michael; Nicolson, Rod; Chan, Philip

2015-03-26

Personal qualities have been shown to affect students' exam results. We studied the effect of experience, and level, of public performance in music, drama, dance, sport, and debate at the time of admission to medical school as a predictor of student achievement in their first objective structured clinical examination (OSCE). A single medical school cohort (n = 265) sitting their first clinical exam in 2011 as third year students were studied. Pre-admission statements made at the time of application were coded for their stated achievements in the level of public performance; participation in each activity was scored 0-3, where 0 was no record, 1 = leisure time activity, 2 = activity at school or local level, 3 = activity at district, regional or national level. These scores were correlated to OSCE results by linear regression and t-test. Comparison was made between the highest scoring students in each area, and students scoring zero by t-test. There was a bell shaped distribution in public performance score in this cohort. There was no significant linear regression relationship between OSCE results and overall performance score, or between any subgroups. There was a significant difference between students with high scores in theatre, debate and vocal music areas, grouped together as verbal performance, and students scoring zero in these areas. (p < 0.05, t-test) with an effect size of 0.4. We found modest effects from pre-admission experience of verbal performance on students' scores in the OSCE examination. As these data are taken from students' admission statements, we call into question the received wisdom that such statements are unreliable.

Perfluorinated cobalt phthalocyanine effectively catalyzes water electrooxidation

KAUST Repository

Morlanes, Natalia Sanchez

2014-12-08

Efficient electrocatalysis of water oxidation under mild conditions at neutral pH was achieved by a fluorinated cobalt phthalocyanine immobilized on fluorine-doped tin oxide (FTO) surfaces with an onset potential at 1.7 V vs. RHE. Spectroscopic, electrochemical, and inhibition studies indicate that phthalocyanine molecular species are the operational active sites. Neither free cobalt ions nor heterogeneous cobalt oxide particles or films were observed. During long-term controlled-potential electrolysis at 2 V vs. RHE (phosphate buffer, pH 7), electrocatalytic water oxidation was sustained for at least 8 h (TON ≈ 1.0 × 105), producing about 4 μmol O2 h-1 cm-2 with a turnover frequency (TOF) of about 3.6 s-1 and no measurable catalyst degradation.

Supramolecular assemblies of pyridyl porphyrin and diazadithia phthalocyanine

Directory of Open Access Journals (Sweden)

OZER BEKAROGLU

1999-08-01

Full Text Available In this paper we report for the first time on a mixed complex between the cationic porphyrin 5, 10, 15, 20-tetra-N- -methyl-pyrydinium-p-il porphyrin (TMPyP and a new metal phthalocyanine with four 16-membered diazadithia macrocycles (denoted here as Pc16, in order to obtain an active complex with an intense absorption on the lower energy side of the visible spectrum and with a higher sensitivity in photodynamic therapy of cancer. The dimerization constant for Pc16 and also the ratio between the oscillator strengths for monomeric and dimeric forms of this compound, were evaluated. The ratio between these oscillator strengths was 2.01 showing a certain dimerization process. The Job mathematical method allowed the establishment of the stoichiometry and the formation constants for the heteroaggregates between the porphyrin and the phthalocy- anine (a diad between one phthalocyanine molecule and one porphyrin molecule and a triad between two phthalocyanine molecules and only one porphyrin molecule. The coulombic attraction resulting from the p-p interaction of the two highly conjugated macrocycles and from the interaction between the substituents, favors a face-to-face geometry.

Enhancing photophysical and photochemical properties of zinc(II) phthalocyanine dyes by substitution of triptycene moieties

Energy Technology Data Exchange (ETDEWEB)

Al-Sohaimi, Bander Roshadan [Department of Chemistry, Faculty of Science, Taibah University, P.O. Box 344, Al-Madinah Al Munawwrah (Saudi Arabia); Pişkin, Mehmet [Çanakkale Onsekiz Mart University, Vocational School of Technical Sciences, Department of Food Technology, Çanakkale 17100 (Turkey); Aljuhani, Ateyatallah; Al-Raqa, Shaya Y. [Department of Chemistry, Faculty of Science, Taibah University, P.O. Box 344, Al-Madinah Al Munawwrah (Saudi Arabia); Durmuş, Mahmut, E-mail: durmus@gtu.edu.tr [Gebze Technical University, Department of Chemistry, P.O. Box 141, Gebze 41400, Kocaeli (Turkey)

2016-05-15

The symmetrical zinc(II) phthalocyanines conjugated with 9,10-dioctyl-6,7-dimethoxy-2,3-dioxytriptycene or 9,10-diundecyl-6,7-dimethoxy-2,3-dioxytriptycene moieties were synthesized in this study. These novel phthalocyanines were characterized by standard characterization techniques such as {sup 1}H-NMR, FT-IR, UV–vis, Mass and Elemental Analysis. All these phthalocyanines showed highly solubility and formed non-aggregated monomeric species in most of the organic solvents. Their photochemical properties such as singlet oxygen, and photodegradation quantum yields, and photophysical properties including fluorescence quantum yields and lifetimes were investigated in toluene. The fluorescence quenching behavior of the studied zinc(II) phthalocyanines by the addition of 1,4-benzoquinone were also described in toluene.

Enhancing photophysical and photochemical properties of zinc(II) phthalocyanine dyes by substitution of triptycene moieties

International Nuclear Information System (INIS)

Al-Sohaimi, Bander Roshadan; Pişkin, Mehmet; Aljuhani, Ateyatallah; Al-Raqa, Shaya Y.; Durmuş, Mahmut

2016-01-01

The symmetrical zinc(II) phthalocyanines conjugated with 9,10-dioctyl-6,7-dimethoxy-2,3-dioxytriptycene or 9,10-diundecyl-6,7-dimethoxy-2,3-dioxytriptycene moieties were synthesized in this study. These novel phthalocyanines were characterized by standard characterization techniques such as 1 H-NMR, FT-IR, UV–vis, Mass and Elemental Analysis. All these phthalocyanines showed highly solubility and formed non-aggregated monomeric species in most of the organic solvents. Their photochemical properties such as singlet oxygen, and photodegradation quantum yields, and photophysical properties including fluorescence quantum yields and lifetimes were investigated in toluene. The fluorescence quenching behavior of the studied zinc(II) phthalocyanines by the addition of 1,4-benzoquinone were also described in toluene.

Efficient small-molecule organic solar cells incorporating a doped buffer layer

Energy Technology Data Exchange (ETDEWEB)

Chou, Dei-Wei [Department of aviation and Communication Electronics, Air Force Institute of Technology, Kaohsiung 820, Taiwan (China); Chen, Kan-Lin [Department of Electronic Engineering, Fortune Institute of Technology, Kaohsiung 831, Taiwan (China); Huang, Chien-Jung, E-mail: chien@nuk.edu.tw [Department of Applied Physics, National University of Kaohsiung, Nanzih, Kaohsiung 811, Taiwan (China); Tsao, Yao-Jen [Department of Applied Physics, National University of Kaohsiung, Nanzih, Kaohsiung 811, Taiwan (China); Chen, Wen-Ray; Meen, Teen-Hang [Department of Electronic Engineering, National Formosa University, Hu-Wei, Yunlin 632, Taiwan (China)

2013-06-01

Small-molecule organic solar cells (OSCs) with an optimized structure of indium tin oxide/poly (3,4-ethylenedioxythioxythiophene):poly(styrenesulfonate)/copper phthalocyanine (CuPc) (10 nm)/CuPc: fullerene (C{sub 60}) mixed (20 nm)/C{sub 60} (20 nm)/4,7-diphenyl-1,10-phenanthroline (BPhen) (5 nm)/Ag were fabricated. In this study, the cesium carbonate-doped BPhen (Cs{sub 2}CO{sub 3}:BPhen) was adopted as the buffer layer to enhance the efficiency of the OSCs. The photovoltaic parameters of the OSCs, such as the short-circuit current density and fill factor, depend on the doping concentration of Cs{sub 2}CO{sub 3} in the BPhen layer. The cell with a Cs{sub 2}CO{sub 3}:BPhen (1:4) cathode buffer layer exhibits a power conversion efficiency (PCE) of 3.51%, compared to 3.37% for the device with the pristine BPhen layer. The enhancement of PCE was attributed to the energy-level alignment between the C{sub 60} layer and the Cs{sub 2}CO{sub 3}:BPhen layer. In addition, the characterization measured using atomic force microscopy shows that the Cs{sub 2}CO{sub 3}:BPhen layers have smoother surfaces. - Highlight: • Cs2CO3-doped 4,7-diphenyl-1,10-phenanthroline (BPhen) cathode buffer layer. • Cs2CO3:BPhen layer with different ratios affects organic solar cells performance. • Cell with 1:4 (Cs2CO3:BPhen) ratio shows 3.51% power conversion efficiency.

Synthesis and characterization of near-IR absorbing metal-free and zinc(II phthalocyanines modified with aromatic azo groups

Directory of Open Access Journals (Sweden)

Mukaddes Özçeşmeci

2015-05-01

Full Text Available Metal-free and zinc(II phthalocyanine complexes bearing peripheral (E-4-((2-hydroxynaphthalen-1-yldiazenyl units have been synthesized. Novel phthalonitrile derivative required for the preparation of phthalocyanine complexes was prepared by coupling 4-aminophthalonitrile and 2-naphthol. The structures of these new compounds were characterized by using elemental analyses, proton nuclear magnetic resonance, fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, fluorescence spectroscopy and mass spectrometry. In the UV-Vis spectra a broad absorption band appears for phthalocyanine complexes at around 450–500 nm resulting from azo-group introduced onto the phthalocyanine ring. The photophysical properties of metal-free and zinc(II phthalocyanines were studied in tetrahydrofuran.

Theoretical study of NMR, infrared and Raman spectra on triple-decker phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Atsushi; Oku, Takeo [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga, 522-8533 (Japan)

2016-02-01

Electronic structures and magnetic properties of multi-decker phthalocyanines were studied by theoretical calculation. Electronic structures, excited processes at multi-states, isotropic chemical shifts of {sup 13}C, {sup 14}N and {sup 1}H-nuclear magnetic resonance (NMR), principle V-tensor in electronic field gradient (EFG) tensor and asymmetry parameters (η), vibration mode in infrared (IR) and Raman spectra of triple-decker phthalocyanines were calculated by density functional theory (DFT) and time-dependent DFT using B3LYP as basis function. Electron density distribution was delocalized on the phthalocyanine rings with electron static potential. Considerable separation of chemical shifts in {sup 13}C, {sup 14}N and {sup 1}H-NMR was originated from nuclear spin interaction between nitrogen and carbon atoms, nuclear quadrupole interaction based on EFG and η of central metal under crystal field. Calculated optical absorption at multi-excited process was derived from overlapping π-orbital on the phthalocyanine rings. The vibration modes in IR and Raman spectra were based on in-plane deformation and stretching vibrations of metal-ligand coordination bond on the deformed structure.

Solvent Effect, Photochemical and Photophysical Properties of Phthalocyanines with Different Metallic Nuclei

Directory of Open Access Journals (Sweden)

Charles Biral Silva

2017-12-01

Full Text Available Photophysical and photochemical properties of lithium phthalocyanine (1, gallium(III phthalocyanine chloride (2, titanium(IV phthalocyanine dichloride (3 and iron(II phthalocyanine (4 were investigated in dimethyl sulfoxide (DMSO, tetrahydrofuran (THF and DMSO-THF mixtures. The influence of the central metal on these properties was analyzed according to solvent type, axial ligands and their paramagnetic and diamagnetic effect. Fluorescence lifetimes were recorded using a time correlated single photon counting setup (TCSPC technique. In order to demonstrate the generation of reactive oxygen species under light irradiation, the indirect method (applying 1,3-diphenylisobenzofuran (DPBF as chemical suppressor and the direct method (analyzing the phosphorescence decay curves of singlete oxygen at 1270 nm were employed. Compounds 1, 2 and 3 showed a monomeric behavior in all media while compound 4 presented low aggregation in DMSO, but a very pronounced aggregation behavior in THF. Steady-state fluorescence anisotropy was compared with emission spectra and complex 4 presented values beyond the expected limits. DOI: http://dx.doi.org/10.17807/orbital.v9i5.1047 

Generalized Optimal-State-Constraint Extended Kalman Filter (OSC-EKF)

Science.gov (United States)

2017-02-01

algorithms is demonstrated by achieving reasonable consistency and accuracy on a challenging micro aerial vehicle dataset. simultaneous localization...platforms exist,4 and many others have been constructed with low-cost components. Visual-inertial simultaneous localization and mapping (SLAM) and...epipolar constraints. The OSC-EKF used a window size of 10 frames. The SAM problem was constructed using an inverse -depth feature position param

Towards functionalization of graphene: in situ study of the nucleation of copper-phtalocyanine on graphene

OpenAIRE

Schwarz, Daniel; Henneke, Caroline; Kumpf, Christian

2016-01-01

Molecular films present an elegant way for the uniform functionalization or doping of graphene. Here, we present an in situ study on the initial growth of copper phthalocyanine (CuPc) on epitaxial graphene on Ir(111). We followed the growth up to a closed monolayer with low energy electron microscopy and selected area electron diffraction (μLEED). The molecules coexist on graphene in a disordered phase without long-range order and an ordered crystalline phase. The local topography of the grap...

Effect of Clinically Discriminating, Evidence-Based Checklist Items on the Reliability of Scores from an Internal Medicine Residency OSCE

Science.gov (United States)

Daniels, Vijay J.; Bordage, Georges; Gierl, Mark J.; Yudkowsky, Rachel

2014-01-01

Objective structured clinical examinations (OSCEs) are used worldwide for summative examinations but often lack acceptable reliability. Research has shown that reliability of scores increases if OSCE checklists for medical students include only clinically relevant items. Also, checklists are often missing evidence-based items that high-achieving…

Water soluble {2-[3-(diethylamino)phenoxy]ethoxy} substituted zinc(II) phthalocyanine photosensitizers

Energy Technology Data Exchange (ETDEWEB)

Çakır, Dilek [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Göl, Cem [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze, 41400, Kocaeli (Turkey); Çakır, Volkan [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Durmuş, Mahmut [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze, 41400, Kocaeli (Turkey); Bıyıklıoğlu, Zekeriya, E-mail: zekeriya_61@yahoo.com [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Kantekin, Halit [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

2015-03-15

The new peripherally and non-peripherally tetra-{2-[3-(diethylamino)phenoxy] ethoxy} substituted zinc phthalocyanines (2a and 3a) were synthesized by cyclotetramerization of phthalonitrile derivatives (2 and 3). 2-[3-(diethylamino)phenoxy] ethoxy group was chosen as substituent because the quaternization of the diethylamino functionality on the structure of this group produced water soluble zinc phthalocyanines (2b and 3b). The water solubility is very important for many different applications such as photosensitizers in the photodynamic therapy of cancer because the water soluble photosensitizers can be injected directly to the body and they can transport to cancer cells through blood stream. The new compounds were characterized by using elemental analysis, UV–vis, IR, {sup 1}H NMR, {sup 13}C NMR and mass spectroscopies. The photophysical and photochemical properties of these novel photosensitizer compounds were examined in DMSO (both non-ionic and ionic complexes) and in PBS (for ionic complexes) solutions. The investigation of these properties is very important for the usage of the compounds as photosensitizers for PDT because determination of these properties is the first stage of potential of the compounds as photosensitizers. The bovine serum albumin (BSA) and DNA binding behaviour of the studied water soluble zinc (II) phthalocyanines were also investigated in PBS solutions for the determination of biological activity of these compounds. - Highlights: • Synthesis of water soluble zinc phthalocyanines. • Photophysical and photochemical properties for phthalocyanines. • Photodynamic therapy studies.

Water soluble {2-[3-(diethylamino)phenoxy]ethoxy} substituted zinc(II) phthalocyanine photosensitizers

International Nuclear Information System (INIS)

Çakır, Dilek; Göl, Cem; Çakır, Volkan; Durmuş, Mahmut; Bıyıklıoğlu, Zekeriya; Kantekin, Halit

2015-01-01

The new peripherally and non-peripherally tetra-{2-[3-(diethylamino)phenoxy] ethoxy} substituted zinc phthalocyanines (2a and 3a) were synthesized by cyclotetramerization of phthalonitrile derivatives (2 and 3). 2-[3-(diethylamino)phenoxy] ethoxy group was chosen as substituent because the quaternization of the diethylamino functionality on the structure of this group produced water soluble zinc phthalocyanines (2b and 3b). The water solubility is very important for many different applications such as photosensitizers in the photodynamic therapy of cancer because the water soluble photosensitizers can be injected directly to the body and they can transport to cancer cells through blood stream. The new compounds were characterized by using elemental analysis, UV–vis, IR, 1 H NMR, 13 C NMR and mass spectroscopies. The photophysical and photochemical properties of these novel photosensitizer compounds were examined in DMSO (both non-ionic and ionic complexes) and in PBS (for ionic complexes) solutions. The investigation of these properties is very important for the usage of the compounds as photosensitizers for PDT because determination of these properties is the first stage of potential of the compounds as photosensitizers. The bovine serum albumin (BSA) and DNA binding behaviour of the studied water soluble zinc (II) phthalocyanines were also investigated in PBS solutions for the determination of biological activity of these compounds. - Highlights: • Synthesis of water soluble zinc phthalocyanines. • Photophysical and photochemical properties for phthalocyanines. • Photodynamic therapy studies

Light-harvesting dendrimer zinc-phthalocyanines chromophores labeled single-wall carbon nanotube nanoensembles: Synthesis and photoinduced electron transfer

Energy Technology Data Exchange (ETDEWEB)

Yang, Hongqin [Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education and Fujian Provincial Key Laboratory for Photonics Technology, Fujian Normal University, Fuzhou 350007 (China); Pan, Sujuan; Ma, Dongdong; He, Dandan; Wang, Yuhua [College of Chemistry & Engineering, Fujian Provincial Key Laboratory of Polymer Materials, Fujian Normal University, Fuzhou 350007 (China); Xie, Shusen [Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education and Fujian Provincial Key Laboratory for Photonics Technology, Fujian Normal University, Fuzhou 350007 (China); Peng, Yiru, E-mail: yirupeng@fjnu.edu.cn [College of Chemistry & Engineering, Fujian Provincial Key Laboratory of Polymer Materials, Fujian Normal University, Fuzhou 350007 (China)

2016-11-15

A novel series of light-harvesting dendrimer zinc-phthalocyanines chromophores labeled-single-wall carbon nanotubes (SWNTs) nanoparticles, in which 0–2 generations dendrimer zinc phthalocyanines covalently linked with SWNTs using either ethylenediamine or hexamethylenediamine as the space linkers were prepared. The structures and morphologies of these nanoconjugates were comprehensively characterized by Raman spectroscopy, transmission electron microscopy and thermal gravimetric analysis methods. Their photophysical properties were investigated by fluorescence and time-resolved spectroscopic methods. The photoinduced intramolecular electron transfer occurred from phthalocyanines (donors) to SWNTs (acceptors). Besides, the electron transfer exchange rates and exchange efficacies between the dendritic phthalocyanines and single-wall carbon nanotubes increased as the length of spacer linker decreased, or as the dendritic generation increased. Cyclic voltammetry (CV) method further confirmed thermodynamics possibility of the electron transfer from phthalocyanines to single-wall carbon nanotubes. These new nanoconjugates are fundamentally important due to the synergy effects of both carbon nanotubes and dendrimer phthalocyanines, which may find potential applications in the fields of drug delivery, biological labeling, or others.

Development and testing of an objective structured clinical exam (OSCE) to assess socio-cultural dimensions of patient safety competency

Science.gov (United States)

Ginsburg, Liane R; Tregunno, Deborah; Norton, Peter G; Smee, Sydney; de Vries, Ingrid; Sebok, Stefanie S; VanDenKerkhof, Elizabeth G; Luctkar-Flude, Marian; Medves, Jennifer

2015-01-01

Background Patient safety (PS) receives limited attention in health professional curricula. We developed and pilot tested four Objective Structured Clinical Examination (OSCE) stations intended to reflect socio-cultural dimensions in the Canadian Patient Safety Institute's Safety Competency Framework. Setting and participants 18 third year undergraduate medical and nursing students at a Canadian University. Methods OSCE cases were developed by faculty with clinical and PS expertise with assistance from expert facilitators from the Medical Council of Canada. Stations reflect domains in the Safety Competency Framework (ie, managing safety risks, culture of safety, communication). Stations were assessed by two clinical faculty members. Inter-rater reliability was examined using weighted κ values. Additional aspects of reliability and OSCE performance are reported. Results Assessors exhibited excellent agreement (weighted κ scores ranged from 0.74 to 0.82 for the four OSCE stations). Learners’ scores varied across the four stations. Nursing students scored significantly lower (p<0.05) than medical students on three stations (nursing student mean scores=1.9, 1.9 and 2.7; medical student mean scores=2.8, 2.9 and 3.5 for stations 1, 2 and 3, respectively where 1=borderline unsatisfactory, 2=borderline satisfactory and 3=competence demonstrated). 7/18 students (39%) scored below ‘borderline satisfactory’ on one or more stations. Conclusions Results show (1) four OSCE stations evaluating socio-cultural dimensions of PS achieved variation in scores and (2) performance on this OSCE can be evaluated with high reliability, suggesting a single assessor per station would be sufficient. Differences between nursing and medical student performance are interesting; however, it is unclear what factors explain these differences. PMID:25398630

Reacting to Conflict: Civilian Capabilities in the EU, UN and OSCE

NARCIS (Netherlands)

Dijkstra, Hylke; Petrov, Petar; Mahr, Ewa

2016-01-01

This report analyses how the EU, UN and OSCE make resources available for civilian missions. It starts with an overview of civilian missions around the world before comparing civilian planning and conduct procedures in these international organisations. The report zooms in on EU civilian

How well do second-year students learn physical diagnosis? Observational study of an objective structured clinical examination (OSCE

Directory of Open Access Journals (Sweden)

Simon Steven R

2002-01-01

Full Text Available Abstract Background Little is known about using the Objective Structured Clinical Examination (OSCE in physical diagnosis courses. The purpose of this study was to describe student performance on an OSCE in a physical diagnosis course. Methods Cross-sectional study at Harvard Medical School, 1997–1999, for 489 second-year students. Results Average total OSCE score was 57% (range 39–75%. Among clinical skills, students scored highest on patient interaction (72%, followed by examination technique (65%, abnormality identification (62%, history-taking (60%, patient presentation (60%, physical examination knowledge (47%, and differential diagnosis (40% (p Conclusions Students scored higher on interpersonal and technical skills than on interpretive or integrative skills. Station scores identified specific content that needs improved teaching.

Kinetic response study in chemiresistive gas sensor based on carbon nanotube surface functionalized with substituted phthalocyanines

Science.gov (United States)

Sharma, Anshul Kumar; Kumar, Pankaj; Saini, Rajan; Bedi, R. K.; Mahajan, Aman

2016-05-01

A kind of hybrid material is prepared by functionalizing multi-wall carbon nanotubes (MWCNTs-COOH) with substituted copper phthalocyanine and the formation of CuPcOC8/MWCNTs-COOH hybrid is confirmed by scanning electron microscopy and transmission electron microscopy. The results indicated that on the surface of nanotubes substituted CuPcOC8 derivatives has been successfully anchored through π-π stacking interaction. The gas sensing application of the fabricated hybrid material is tested upon exposure to different hazardous species, specifically NO2, NO, Cl2 and NH3 at operating temperature of 150˚C. It has been demonstrated that for Cl2 minimum detection limit of CuPcOC8/MWCNTs-COOH hybrid is 100 ppb. The response of hybrid sensor is found to be increased with increase in the concentration of Cl2.

Fluorescence behavior and singlet oxygen generating abilities of aluminum phthalocyanine in the presence of anisotropic gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Mthethwa, Thandekile; Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za

2015-01-15

Gold nanoparticles (spheres, rods and bipyramids) were synthesized. The nanocrystals were characterized by UV–visible spectrometry, transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The as prepared gold nanoparticles were then conjugated to a quaternized 2,(3)-tetra [2-(dimethylamino) ethanethio] substituted Al(OH) phthalocyanine (complex 1). The conjugation of phthalocyanines with gold nanoparticles resulted in a decrease in the fluorescence quantum yields and lifetimes. Conversely, an increase in the singlet oxygen quantum yields was observed for the conjugated complex 1 in the presence of AuNPs. - Highlights: • Gold nanoparticles (spheres, rods and bipyramids) were synthesized. • Gold nanoparticles were then conjugated to a quaternized ClAl phthalocyanine. • Conjugation of phthalocyanines with gold nanoparticles resulted in a decrease in the fluorescence quantum yields. • An increase in the singlet oxygen quantum yields was observed for the phthalocyanine in the presence of nanoparticles.

Energy level alignment at the Si(1 1 1)/RCA–SiO2/copper(II) phthalocyanine ultra-thin film interface

International Nuclear Information System (INIS)

Krzywiecki, Maciej; Grządziel, Lucyna

2014-01-01

Graphical abstract: - Highlights: • The interface formation studies between CuPc and Si by photoemission methods. • Charge rearrangement detected at the inorganic/organic interface. • Existence of disordered/polarization layer at the initial stages of CuPc deposition. • Examined structures applicable for organic transistors development. - Abstract: The photoemission experimental techniques (i.e. ultraviolet photoelectron spectroscopy—UPS and X-ray photoelectron spectroscopy—XPS) were used to investigate the charge–rearrangement–related phenomena occuring at organic–inorganic semiconductor interface. Examined samples were copper phthalocyanine (CuPc) ultra-thin (up to 16 nm) layers deposited onto oxidized silicon Si(1 1 1) of n- and p-type of conductivity. The 1.3-nm-thick silicon oxide was prepared by means of RCA wet cleaning procedure. The analysis of the photoemission data (mainly UPS) suggested the existance of the polarization layer within first 3 nm of CuPc layer thickness. Basing on the UPS and XPS results the energy level diagrams of examined structures have been constructed. In present paper it is suggested that the existance of the polarization layer could be assigned to the disordered adsorption and continous molecular reorientation of the CuPc molecules during the interface formation process. In the terms of the lack of the charge transfer via substrate/organic overlayer interface and disordered adsorption the fluctuations of CuPc electronic parameters were detected. Moreover the ionization energy and the work function parameters of final CuPc layer were affected. The values were more consistent with those obtained for much thicker (over 500 nm) CuPc layers. Performed studies showed that contrary to CuPc layers deposited on native substrates (where the charge transfer via tunnelable oxide – determined as dipole effect – has been detected), the thicker RCA-prepared oxide seems to be non-tunnelable hence the possibility for Si(1 1 1

Graphene and Carbon-Nanotube Nanohybrids Covalently Functionalized by Porphyrins and Phthalocyanines for Optoelectronic Properties.

Science.gov (United States)

Wang, Aijian; Ye, Jun; Humphrey, Mark G; Zhang, Chi

2018-04-01

In recent years, there has been a rapid growth in studies of the optoelectronic properties of graphene, carbon nanotubes (CNTs), and their derivatives. The chemical functionalization of graphene and CNTs is a key requirement for the development of this field, but it remains a significant challenge. The focus here is on recent advances in constructing nanohybrids of graphene or CNTs covalently linked to porphyrins or phthalocyanines, as well as their application in nonlinear optics. Following a summary of the syntheses of nanohybrids constructed from graphene or CNTs and porphyrins or phthalocyanines, explicit intraconjugate electronic interactions between photoexcited porphyrins/phthalocyanines and graphene/CNTs are introduced classified by energy transfer, electron transfer, and charge transfer, and their optoelectronic applications are also highlighted. The major current challenges for the development of covalently linked nanohybrids of porphyrins or phthalocyanines and carbon nanostructures are also presented. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Soluble phthalocyanines - new materials for optoelectronics

Czech Academy of Sciences Publication Activity Database

Biler, M.; Zhivkov, I.; Rakušan, J.; Karásková, M.; Pochekailov, S.; Wang, G.; Nešpůrek, Stanislav

2005-01-01

Roč. 7, č. 3 (2005), s. 1365-1370 ISSN 1454-4164 R&D Projects: GA MPO FT-TA/036; GA MŠk ME 700 Institutional research plan: CEZ:AV0Z40500505 Keywords : phthalocyanine * poly[3,4-(ethylenedioxy)thiophene] * electrical properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.138, year: 2005

Theoretical investigation of the electronic structure of a substituted nickel phthalocyanine

Energy Technology Data Exchange (ETDEWEB)

Kaur, Prabhjot, E-mail: prabhphysics@gmail.com; Sachdeva, Ritika [Department of Physics, Panjab University Chandigarh-160014, Chandigarh (India); Singh, Sukhwinder [Department of Physics, Govt. College for Girls, Ludhiana-141008, Ludhiana (India)

2016-05-23

The optimized geometry and electronic structure of an organic compound nickel phthalocyanine tetrasulfonic acid tetra sodium salt have been investigated using density functional theory. We have also optimized the structure of nickel phthalocyanine tetrasulfonic acid tetra sodium salt in dimethyl sulfoxide to study effects of solvent on the electronic structure and transitions. Experimentally, the electronic transitions have been studied using UV-VIS spectroscopic technique. It is observed that the electronic transitions obtained from the theoretical studies generally agree with the experiment.

Unsymmetrical extended π-conjugated zinc phthalocyanine for ...

Indian Academy of Sciences (India)

Administrator

mental compatibility compared to the ruthenium dyes. 2–6 ... for the development of efficient light-to-energy con- version devices. .... solution and compared to that of the phthalocyanine adsorbed onto 2 μm .... of dark current. 25. In this study ...

Belarus and Russia in OSCE Ministerial Council focus / Rokas M. Tracevskis

Index Scriptorium Estoniae

Tracevskis, Rokas M.

2011-01-01

6.-7. detsembril Vilniuses toimunud OSCE Ministrite Nõukogu kohtumisel räägiti inimõiguste probleemidest, meediavabadusest, Afganistanist, Araabia kevadest, Valgevenes toimuvast ja Venemaal toimunud parlamendivalimistest. Kohtumise avas Leedu president Dalia Grybauskaite. 6. detsembril kohtus USA riigisekretär Hillary Clinton president Dalia Grybauskaite ja välisminister Audronius Azubalisega

Functionalization of nanocrystalline diamond films with phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Petkov, Christo [Institute of Nanostructure Technologies and Analytics (INA), Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel (Germany); Reintanz, Philipp M. [Institute of Chemistry, Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel (Germany); Kulisch, Wilhelm [Institute of Nanostructure Technologies and Analytics (INA), Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel (Germany); Degenhardt, Anna Katharina [Institute of Chemistry, Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel (Germany); Weidner, Tobias [Max Planck Institute for Polymer Research, Mainz (Germany); Baio, Joe E. [School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR (United States); Merz, Rolf; Kopnarski, Michael [Institut für Oberflächen- und Schichtanalytik (IFOS), Kaiserslautern (Germany); Siemeling, Ulrich [Institute of Chemistry, Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel (Germany); Reithmaier, Johann Peter [Institute of Nanostructure Technologies and Analytics (INA), Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel (Germany); Popov, Cyril, E-mail: popov@ina.uni-kassel.de [Institute of Nanostructure Technologies and Analytics (INA), Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel (Germany)

2016-08-30

Highlights: • Grafting of phthalocyanines on nanocrystalline diamond films with different terminations. • Pc with different central atoms and side chains synthesized and characterized. • Attachment of Pc on H- and O-terminated NCD studied by XPS and NEXAFS spectroscopy. • Orientation order of phthalocyanine molecules on NCD surface. - Abstract: Phthalocyanine (Pc) derivatives containing different central metal atoms (Mn, Cu, Ti) and different peripheral chains were synthesized and comprehensively characterized. Their interaction with nanocrystalline diamond (NCD) films, as-grown by hot-filament chemical vapor deposition or after their modification with oxygen plasma to exchange the hydrogen termination with oxygen-containing groups, was studied by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The elemental composition as determined by XPS showed that the Pc were grafted on both as-grown and O-terminated NCD. Mn, Cu and Ti were detected together with N stemming from the Pc ring and S in case of the Ti-Pc from the peripheral ligands. The results for the elemental surface composition and the detailed study of the N 1s, S 2p and O 1s core spectra revealed that Ti-Pc grafted better on as-grown NCD but Cu-Pc and Mn-Pc on O-terminated films. Samples of Mn-Pc on as-grown and O-terminated NCD were further investigated by NEXAFS spectroscopy. The results showed ordering of the grafted molecules, laying flat on the H-terminated NCD surface while only the macrocycles were oriented parallel to the O-terminated surface with the peripheral chains perpendicular to it.

Investigation of Various Active Layers for Their Performance on Organic Solar Cells

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Pao-Hsun Huang

2016-08-01

Full Text Available The theoretical mechanism of open-circuit voltages (VOC in OSCs based on various small molecule organic materials is studied. The structure under investigation is simple planar heterojunction (PHJ by thermal vacuum evaporation deposition. The various wide band gaps of small molecule organic materials are used to enhance the power conversion efficiency (PCE. The donor materials used in the device include: Alpha-sexithiophene (α-6T, Copper(II phthalocyanine (CuPc, boron subnaphthalocyanine chloride (SubNc and boron Subphthalocyanine chloride (SubPc. It is combined with fullerene or SubPc acceptor material to obtain a comprehensive understanding of the charge transport behavior. It is found that the VOC of the device is largely limited by charge transport. This was associated with the space charge effects and hole accumulation. These results are attributed to the improvement of surface roughness and work function after molybdenum trioxide (MoO3 is inserted as an anode buffer layer.

Investigation of Various Active Layers for Their Performance on Organic Solar Cells.

Science.gov (United States)

Huang, Pao-Hsun; Wang, Yeong-Her; Ke, Jhong-Ciao; Huang, Chien-Jung

2016-08-09

The theoretical mechanism of open-circuit voltages (V OC ) in OSCs based on various small molecule organic materials is studied. The structure under investigation is simple planar heterojunction (PHJ) by thermal vacuum evaporation deposition. The various wide band gaps of small molecule organic materials are used to enhance the power conversion efficiency (PCE). The donor materials used in the device include: Alpha-sexithiophene (α-6T), Copper(II) phthalocyanine (CuPc), boron subnaphthalocyanine chloride (SubNc) and boron Subphthalocyanine chloride (SubPc). It is combined with fullerene or SubPc acceptor material to obtain a comprehensive understanding of the charge transport behavior. It is found that the V OC of the device is largely limited by charge transport. This was associated with the space charge effects and hole accumulation. These results are attributed to the improvement of surface roughness and work function after molybdenum trioxide (MoO₃) is inserted as an anode buffer layer.

Improved Reliability of Small Molecule Organic Solar Cells by Double Anode Buffer Layers

Directory of Open Access Journals (Sweden)

Pao-Hsun Huang

2014-01-01

Full Text Available An optimized hybrid planar heterojunction (PHJ of small molecule organic solar cells (SM-OSCs based on copper phthalocyanine (CuPc as donor and fullerene (C60 as acceptor was fabricated, which obviously enhanced the performance of device by sequentially using both MoO3 and pentacene as double anode buffer layers (ABL, also known as hole extraction layer (HEL. A series of the vacuum-deposited ABL, acting as an electron and exciton blocking layer, were examined for their characteristics in SM-OSCs. The performance and reliability were compared between conventional ITO/ABL/CuPc/C60/BCP/Ag cells and the new ITO/double ABL/CuPc/C60/BCP/Ag cells. The effect on the electrical properties of these materials was also investigated to obtain the optimal thickness of ABL. The comparison shows that the modified cell has an enhanced reliability compared to traditional cells. The improvement of lifetime was attributed to the idea of double layers to prevent humidity and oxygen from diffusing into the active layer. We demonstrated that the interfacial extraction layers are necessary to avoid degradation of device. That is to say, in normal temperature and pressure, a new avenue for the device within double buffer layers has exhibited the highest values of open circuit voltage (Voc, fill factor (FF, and lifetime in this work compared to monolayer of ABL.

Photophysical, Photochemical, and BQ Quenching Properties of Zinc Phthalocyanines with Fused or Interrupted Extended Conjugation

Directory of Open Access Journals (Sweden)

Gülşah Gümrükçü

2014-01-01

Full Text Available The effects of substituents and solvents on the photophysical and photochemical parameters of zinc(II phthalocyanines containing four Schiff’s base substituents attached directly and through phenyleneoxy-bridges on peripheral positions are reported. The group effects on peripheral position and the continual and intermittent conjugation of the phthalocyanine molecules on the photophysical and photochemical properties are also investigated. General trends are described for photodegradation, singlet oxygen, and fluorescence quantum yields of these compounds in dimethylsulfoxide (DMSO, dimethylformamide (DMF, and tetrahydrofurane (THF. Among the different substituents, phthalocyanines with cinnamaldimine moieties (1c and 2c have the highest singlet oxygen quantum yields (ΦΔ and those with nitro groups (1a and 2a have the highest fluorescence quantum yields in all the solvents used. The fluorescence of the substituted zinc(II phthalocyanine complexes is effectively quenched by 1,4-benzoquinone (BQ in these solvents.

Investigation of interaction between alkoxy substituted phthalocyanines with different lengths of alkyl residue and bovine serum albumin

Energy Technology Data Exchange (ETDEWEB)

Lebedeva, Natalya Sh., E-mail: nsl@isc-ras.ru [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Akademicheskaya, 1, 153045 Ivanovo (Russian Federation); Gubarev, Yury A.; Vyugin, Anatoly I. [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Akademicheskaya, 1, 153045 Ivanovo (Russian Federation); Koifman, Oscar I. [Research Institute of Macroheterocycles of Ivanovo State University of Chemistry and Technology, 153000 Ivanovo (Russian Federation)

2015-10-15

Interaction between bovine serum albumin and alkoxy substituted phthalocyanines was studied by means of electron absorption spectroscopy, fluorescence spectroscopy and viscosimetry. The binding constants and binding distance were calculated. It was found that ZnPc(4-NH-CO-C{sub 6}H{sub 4}-OC{sub 10}H{sub 21}){sub 4} prevents twisting of BSA molecule and localizes between subdomains IB and IIA in protein globule. ZnPc(4-NH-CO-C{sub 6}H{sub 4}-OC{sub 6}H{sub 13}){sub 4} and ZnPc(4-NH-CO-C{sub 6}H{sub 4}-OC{sub 8}H{sub 17}){sub 4} are located on the outer surface of the protein globule. In the case of ZnPc(4-NH-CO-C{sub 6}H{sub 4}-OC{sub 3}H{sub 7}){sub 4} it can be assumed that the phthalocyanine molecule is in the immediate vicinity of the subdomains IB and IIA. - Highlights: • Interaction between bovine serum albumin and alkoxy substituted phthalocyanines was studied by means of electron absorption spectroscopy, fluorescence spectroscopy and viscosimetry. • The binding constants and binding distance were calculated by using the Scatchard method. • Photochemical characteristics of phthalocyanines of studied phthalocyanines are defined. • Localization of phthalocyanines on the protein globule is defined.

Using Item Analysis to Assess Objectively the Quality of the Calgary-Cambridge OSCE Checklist

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Tyrone Donnon

2011-06-01

Full Text Available Background:  The purpose of this study was to investigate the use of item analysis to assess objectively the quality of items on the Calgary-Cambridge Communications OSCE checklist. Methods:  A total of 150 first year medical students were provided with extensive teaching on the use of the Calgary-Cambridge Guidelines for interviewing patients and participated in a final year end 20 minute communication OSCE station.  Grouped into either the upper half (50% or lower half (50% communication skills performance groups, discrimination, difficulty and point biserial values were calculated for each checklist item. Results:  The mean score on the 33 item communication checklist was 24.09 (SD = 4.46 and the internal reliability coefficient was ? = 0.77. Although most of the items were found to have moderate (k = 12, 36% or excellent (k = 10, 30% discrimination values, there were 6 (18% identified as ‘fair’ and 3 (9% as ‘poor’. A post-examination review focused on item analysis findings resulted in an increase in checklist reliability (? = 0.80. Conclusions:  Item analysis has been used with MCQ exams extensively. In this study, it was also found to be an objective and practical approach to use in evaluating the quality of a standardized OSCE checklist.

The Objective Structured Clinical Examination (OSCE) as a strategy for assessing clinical competence in midwifery education in Ireland: a critical review.

Science.gov (United States)

Smith, Valerie; Muldoon, Kathryn; Biesty, Linda

2012-09-01

In Ireland, to register as a midwife, all student midwives must be deemed competent to practice with the assessment of competence an essential component of midwifery education. A variety of assessment strategies, including observed practice, clinical interviews, portfolios of reflection, the Objective Structured Clinical Examination (OSCE) and written examination papers, are utilised to assess midwifery students' clinical competence. In this paper, a critical review of the OSCE as a strategy for assessing clinical competence in one third level institution in Ireland is offered. Although utilised for assessing competence across a range of areas (e.g. obstetric emergencies and pharmacology/drug administration), the use of the OSCE for assessing midwifery students' competence in lactation and infant feeding practices, as an example for this paper, is described. The advantages, disadvantages, validity and reliability of the OSCE, as an assessment strategy, are critically explored. Recognising that no single assessment strategy can provide all the information required to assess something as complex as clinical performance, the OSCE, when viewed alongside other forms of assessment, and with relevance to the topic under examination, may be considered a valuable strategy for enhancing the assessment of students' clinical competence, and for embracing diversity within midwifery education and training. Copyright © 2012 Elsevier Ltd. All rights reserved.

Tetra- and octa-[4-(2-hydroxyethyl)phenoxy bearing novel metal-free and zinc(II) phthalocyanines: Synthesis, characterization and investigation of photophysicochemical properties

Energy Technology Data Exchange (ETDEWEB)

Köksoy, Baybars [Marmara University, Department of Chemistry, 34722 Kadıköy, Istanbul (Turkey); Durmuş, Mahmut [Gebze Technical University, Department of Chemistry, 41400 Gebze, Kocaeli (Turkey); Bulut, Mustafa, E-mail: mbulut@marmara.edu.tr [Marmara University, Department of Chemistry, 34722 Kadıköy, Istanbul (Turkey)

2015-05-15

In this study, four novel phthalonitriles (1–4) and their corresponding metal-free (5–8) and zinc(II) phthalocyanine derivatives (9–12) bearing 4-(hydroxyethyl)phenoxy groups were synthesized. These novel compounds were characterized by IR, elemental analyses, {sup 1}H-NMR, UV–vis, and MALDI-TOF spectral data. Furthermore, photophysical (fluorescence quantum yields and lifetimes) and photochemical properties (singlet oxygen generation and photodegradation quantum yields) of these phthalocyanines were investigated in dimethylsulfoxide. The studied zinc(II) phthalocyanines generated highly singlet oxygen which is very important for the photodynamic therapy (PDT) of cancer. The fluorescence quenching behaviour of the newly synthesized phthalocyanine compounds were also investigated using 1,4-benzoquinone. - Highlights: • Octa and tetra 4-(hydroxyethyl)phenoxy substituted metal-free and zinc(II) phthalocyanines. • Study of photophysicochemical properties of eight new phthalocyanines. • Highly singlet oxygen generation for novel zinc(II) phthalocyanine photosensitizers.

Control of in-plane orientation of phthalocyanine molecular columns using vicinal Si(001)-(2x1)-H

International Nuclear Information System (INIS)

Nakamura, Masakazu; Matsunobe, Takeshi; Tokumoto, Hiroshi

2001-01-01

In-plane crystal orientation of copper phthalocyanine (CuPc) films formed by organic molecular-beam epitaxy have been successfully controlled by using vicinal Si(001)-(2x1)-H as a substrate, containing atomic steps of an approximately 4 nm period. A continuous film was grown at 60 degree C and the film thickness ranged between 5 and 8 molecular layers. By observing a frictional force image of the film, 90% of the molecular columns were found to align across the substrate step rows. The preferential orientation is considered to be induced by artificial surface lattices, which result from the striped effective contact area between the rigid CuPc crystals and the stair-like surfaces. The anisotropic optical properties of the film have been also confirmed by polarized reflection measurements. [copyright] 2001 American Institute of Physics

Synthesis of mesogenic phthalocyanine-C60 donor–acceptor dyads designed for molecular heterojunction photovoltaic devices

Directory of Open Access Journals (Sweden)

Yves Henri Geerts

2009-10-01

Full Text Available A series of phthalocyanine-C60 dyads 2a–d was synthesized. Key steps in their synthesis are preparation of the low symmetry phthalocyanine intermediate by the statistical condensation of two phthalonitriles, and the final esterification of the fullerene derivative bearing a free COOH group. Structural characterization of the molecules in solution was performed by NMR spectroscopy, UV–vis spectroscopy and cyclic voltammetry. Preliminary studies suggest formation of liquid crystalline (LC mesophases for some of the prepared dyads. To the best of our knowledge, this is the first example of LC phthalocyanine-C60 dyads.

Sulphonated Phthalocyanines as Effective Oxidation Photocatalysts

Czech Academy of Sciences Publication Activity Database

Klusoň, P.; Drobek, M.; Strašák, Tomáš; Krýsa, J.; Karásková, M.; Rakušak, J.

2008-01-01

Roč. 272, 1-2 (2008), s. 213-219 ISSN 1381-1169 R&D Projects: GA ČR(CZ) GD203/03/H140; GA AV ČR(CZ) KAN400720701 Institutional research plan: CEZ:AV0Z40720504 Keywords : phthalocyanines * 4-Chlorophenol * photocatalysis Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.814, year: 2008

The Synthesis And Characterization Of Wolfram Phthalocyanine For The Target Material Of High Specific Activity Radioisotope Wolfram - 188 (188W)

International Nuclear Information System (INIS)

Setiawan, Duyeh

2000-01-01

The application of 188 Re radioisotope separation on aluminia column through elution solution has increased significantly since the last two decades. The 188 Re radioisotope has been done fram 188 Re beta-decay through a neutron capture radiation on wolfram -186 target. In trhe column separation, high specific activity of 188 W radioisotope is required to get sufficient activity in small quality 188 W radioisotope has been carried out in this research. Wolfram-phthalocyanine compound was prepared by refluxing a mixture of wolfram trioxyde, (WO 3 ) and phthalonitrile, (C 8 H 4 N 2 ) at 250 o C for two hours. The synthesis of wolfram phthalocyanine is 70% purity yield, the product are green crystals, have a 193,0-193,8 o C melting points, and has a molecular formula C 3 2H 1 6 N8 WO 2 . The infra red spectrum of wolfram-phthalocyanine was the absorption band at 964,3 cm - 1 was due to the vibration of W=O bond of the wolfram dioxy-phthalocyanine. The x-ray diffraction of the wolfram dioxy-phthalocyanine was similar with molybdenum dioxy-phthalocyanine compound. This fact showed that the product was wolfram dioxy-phthalocyanine

Kinetic response study in chemiresistive gas sensor based on carbon nanotube surface functionalized with substituted phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Sharma, Anshul Kumar; Saini, Rajan; Bedi, R. K.; Mahajan, Aman, E-mail: dramanmahajan@yahoo.co.in, E-mail: anshulsharma.phy@gmail.com [Material Science Laboratory, Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Kumar, Pankaj [Department of Applied Sciences, I.K. Gujral Punjab Technical University, Kapurthala 144601 (India)

2016-05-06

A kind of hybrid material is prepared by functionalizing multi-wall carbon nanotubes (MWCNTs-COOH) with substituted copper phthalocyanine and the formation of CuPcOC{sub 8}/MWCNTs-COOH hybrid is confirmed by scanning electron microscopy and transmission electron microscopy. The results indicated that on the surface of nanotubes substituted CuPcOC{sub 8} derivatives has been successfully anchored through π-π stacking interaction. The gas sensing application of the fabricated hybrid material is tested upon exposure to different hazardous species, specifically NO{sub 2}, NO, Cl{sub 2} and NH{sub 3} at operating temperature of 150°C. It has been demonstrated that for Cl{sub 2} minimum detection limit of CuPcOC{sub 8}/MWCNTs-COOH hybrid is 100 ppb. The response of hybrid sensor is found to be increased with increase in the concentration of Cl{sub 2}.

Surface chemistry and electrocatalytic behaviour of tetra-carboxy substituted iron, cobalt and manganese phthalocyanine monolayers on gold electrode

International Nuclear Information System (INIS)

Mashazi, Philani N.; Westbroek, Philippe; Ozoemena, Kenneth I.; Nyokong, Tebello

2007-01-01

Surface chemistry and electrocatalytic properties of self-assembled monolayers of metal tetra-carboxylic acid phthalocyanine complexes with cobalt (Co), iron (Fe) and manganese (Mn) as central metal ions have been studied. These phthalocyanine molecules are immobilized on gold electrode via the coupling reaction between the ring substituents and pre-formed mercaptoethanol self-assembled monolayer (Au-ME SAM). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy confirmed chemisorption of mercaptoethanol via sulfur group on gold electrode and also coupling reaction between phthalocyanines and Au-ME SAM. Electrochemical parameters of the immobilized molecules show that these molecules are densely packed with a perpendicular orientation. The potential applications of the gold modified electrodes were investigated towards L-cysteine detection and the analysis at phthalocyanine SAMs. Cobalt and iron tetra-carboxylic acid phthalocyanine monolayers showed good oxidation peak for L-cysteine at potentials where metal oxidation (M III /M II ) takes place and this metal oxidation mediates the catalytic oxidation of L-cysteine. Manganese tetra-carboxylic acid phthalocyanine monolayer also exhibited a good catalytic oxidation peak towards L-cysteine at potentials where Mn IV /Mn III redox peak occurs and this redox peak mediates L-cysteine oxidation. The analysis of cysteine at phthalocyanine monolayers displayed good analytical parameters with good detection limits of the orders of 10 -7 mol L -1 and good linearity for a studied concentration range up to 60 μmol L -1

Synthesis, photophysical and electrochemical properties of water–soluble phthalocyanines bearing 8-hydroxyquinoline-5-sulfonicacid derivatives

Energy Technology Data Exchange (ETDEWEB)

Günsel, Armağan; Kocabaş, Sibel; Bilgiçli, Ahmet T. [Department of Chemistry, Sakarya University, 54140 Esentepe, Sakarya (Turkey); Güney, Sevgi [Department of Chemistry, Istanbul Technical University, 34469 Maslak, Istanbul (Turkey); Kandaz, Mehmet, E-mail: mkandaz@sakarya.edu.tr [Department of Chemistry, Sakarya University, 54140 Esentepe, Sakarya (Turkey)

2016-08-15

We have presented in this paper, the synthesis, characterization, photophysical properties and electrochemical characterization of water soluble phthalocyanines (Pcs) bearing 8-hydroxyquinoline-5-sulfonicacid conjugates and their cationic quaternized counterpart that play important roles their application in photodynamic therapy (PDT). The periphery and non-periphery substituted phthalocyanines show high solubility and low aggregation tendency due to bulky 8-hydroxyquinoline-5-sulfonicacid steric hindrance moieties and axially bound counter chlorine anion. Singlet oxygen quantum yields, photodegradation quantum yields, photophysical properties and also the nature of the substituent and solvent effect on the photophysical and photochemical parameters of α-ZnPc and β-ZnPc are reported. In electrovalent cobalt (II) and manganese (III) compounds, metal based electron transfer reactions have been observed in addition to the common phthalocyanine ring-based electron transfer processes. The effect of point of substitution on the electrochemical properties of newly synthesized phthalocyanines substituted with 8-hydroxyquinoline-5-sulfonicacid group were evaluated.

Water soluble peripheral and non-peripheral tetrasubstituted zinc phthalocyanines: Synthesis, photochemistry and bovine serum albumin binding behavior

Energy Technology Data Exchange (ETDEWEB)

Çakır, Volkan; Çakır, Dilek [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Pişkin, Mehmet [Department of Food Technology, Çanakkale Vocational School of Technical Sciences, Çanakkale Onsekiz Mart University, 17100 Çanakkale (Turkey); Durmuş, Mahmut [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze 41400, Kocaeli (Turkey); Bıyıklıoğlu, Zekeriya, E-mail: zekeriya_61@yahoo.com [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

2014-10-15

The new peripherally and non-peripherally tetra-1,3-bis[3-(diethylamino)phenoxy]propan-2-ol substituted zinc(II) phthalocyanine complexes (2a and 3a) and their quaternized amphiphilic derivatives (2b and 3b) have been synthesized and characterized using UV–vis, FT-IR, {sup 1}H-NMR, {sup 13}C-NMR, MS spectroscopic data and elemental analysis for the first time. The quaternized complexes (2b and 3b) show excellent solubility in water and DMSO which makes them potential photosensitizers for use in photodynamic therapy (PDT) of cancer. The photochemical (singlet oxygen generation and photodegradation under light irradiation) properties of these novel phthalocyanines are investigated in dimethylsulfoxide (DMSO) for non-quaternized complexes and in DMSO, phosphate buffered solution (PBS) or PBS+triton X-100 (TX) solution for quaternized complexes. In this study, the effects of the aggregation of the molecules, quaternization, position of the substituents (peripherally or non-peripherally) and nature of the solvents (DMSO, PBS or PBS+triton X-100) on the photochemical parameters of the zinc (II) phthalocyanines are also reported. In addition, a spectroscopic investigation of the binding behavior of the quaternized zinc(II) phthalocyanine complexes to bovine serum albumin (BSA) is also presented in this work. - Highlights: • Synthesis of zinc phthalocyanines is performed. • Photophysical and photochemical properties of phthalocyanines are studied. • Photodynamic therapy studies are performed.

Water soluble peripheral and non-peripheral tetrasubstituted zinc phthalocyanines: Synthesis, photochemistry and bovine serum albumin binding behavior

International Nuclear Information System (INIS)

Çakır, Volkan; Çakır, Dilek; Pişkin, Mehmet; Durmuş, Mahmut; Bıyıklıoğlu, Zekeriya

2014-01-01

The new peripherally and non-peripherally tetra-1,3-bis[3-(diethylamino)phenoxy]propan-2-ol substituted zinc(II) phthalocyanine complexes (2a and 3a) and their quaternized amphiphilic derivatives (2b and 3b) have been synthesized and characterized using UV–vis, FT-IR, 1 H-NMR, 13 C-NMR, MS spectroscopic data and elemental analysis for the first time. The quaternized complexes (2b and 3b) show excellent solubility in water and DMSO which makes them potential photosensitizers for use in photodynamic therapy (PDT) of cancer. The photochemical (singlet oxygen generation and photodegradation under light irradiation) properties of these novel phthalocyanines are investigated in dimethylsulfoxide (DMSO) for non-quaternized complexes and in DMSO, phosphate buffered solution (PBS) or PBS+triton X-100 (TX) solution for quaternized complexes. In this study, the effects of the aggregation of the molecules, quaternization, position of the substituents (peripherally or non-peripherally) and nature of the solvents (DMSO, PBS or PBS+triton X-100) on the photochemical parameters of the zinc (II) phthalocyanines are also reported. In addition, a spectroscopic investigation of the binding behavior of the quaternized zinc(II) phthalocyanine complexes to bovine serum albumin (BSA) is also presented in this work. - Highlights: • Synthesis of zinc phthalocyanines is performed. • Photophysical and photochemical properties of phthalocyanines are studied. • Photodynamic therapy studies are performed

Antibacterial effect of cationic porphyrazines and anionic phthalocyanine and their interaction with plasmid DNA

Science.gov (United States)

Hassani, Leila; Hakimian, Fatemeh; Safaei, Elham; Fazeli, Zahra

2013-11-01

Resistance to antibiotics is a public health issue and identification of new antibacterial agents is one of the most important goals of pharmacological research. Among the novel developed antibacterial agents, porphyrin complexes and their derivatives are ideal candidates for use in medical applications. Phthalocyanines differ from porphyrins by having nitrogen atoms link the individual pyrrol units. The aza analogues of the phthalocyanines (azaPcs) such as tetramethylmetalloporphyrazines are heterocyclic Pc analogues. In this investigation, interaction of an anionic phthalocyanine (Cu(PcTs)) and two cationic tetrapyridinoporphyrazines including [Cu(2,3-tmtppa)]4+ and [Cu(3,4-tmtppa)]4+ complexes with plasmid DNA was studied using spectroscopic and gel electrophoresis methods. In addition, antibacterial effect of the complexes against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria was investigated using dilution test method. The results indicated that both porphyrazines have significant antibacterial properties, but Cu(PcTs) has weak antibacterial effect. Compairing the binding of the phthalocyanine and the porphyrazines to DNA demonstrated that the interaction of cationic porphyrazines is stronger than the anionic phthalocyanine remarkably. The extent of hypochromicity and red shift of absorption spectra indicated preferential intercalation of the two porphyrazine into the base pairs of DNA helix. Gel electrophoresis result implied Cu(2,3-tmtppa) and Cu(3,4-tmtppa) are able to perform cleavage of the plasmid DNA. Consequently, DNA binding and cleavage might be one of the antibacterial mechanisms of the complexes.

Metal-phthalocyanine ordered layers on Au(110): Metal-dependent adsorption energy

Energy Technology Data Exchange (ETDEWEB)

Massimi, Lorenzo, E-mail: lorenzo.massimi@uniroma1.it; Angelucci, Marco; Gargiani, Pierluigi; Betti, Maria Grazia [Dipartimento di Fisica, Università di Roma La “Sapienza,” 00185 Roma (Italy); Montoro, Silvia [IFIS Litoral, CONICET-UNL, Laboratorio de Fisica de Superficies e Interfaces, Güemes 3450, Santa Fe (Argentina); Mariani, Carlo, E-mail: carlo.mariani@uniroma1.it [Dipartimento di Fisica, CNISM, Università di Roma La “Sapienza,” 00185 Roma (Italy)

2014-06-28

Iron-phthalocyanine and cobalt-phthalocyanine chains, assembled along the Au(110)-(1×2) reconstructed channels, present a strong interaction with the Au metallic states, via the central metal ion. X-ray photoemission spectroscopy from the metal-2p core-levels and valence band high-resolution ultraviolet photoelectron spectroscopy bring to light signatures of the interaction of the metal-phthalocyanine single-layer with gold. The charge transfer from Au to the molecule causes the emerging of a metal-2p core level component at lower binding energy with respect to that measured in the molecular thin films, while the core-levels associated to the organic macrocycle (C and N 1s) are less influenced by the adsorption, and the macrocycles stabilize the interaction, inducing a strong interface dipole. Temperature Programmed Desorption experiments and photoemission as a function of temperature allow to estimate the adsorption energy for the thin-films, mainly due to the molecule-molecule van der Waals interaction, while the FePc and CoPc single-layers remain adsorbed on the Au surface up to at least 820 K.

Standardised clients as assessors in a veterinary communication OSCE: a reliability and validity study.

Science.gov (United States)

Artemiou, E; Adams, C L; Hecker, K G; Vallevand, A; Violato, C; Coe, J B

2014-11-22

In human medicine, standardised patients (SP) have been shown to reliably and accurately assess learners' communication performance in high-stakes certification Objective Structured Clinical Examinations (OSCE), offering a feasible way to reduce the need for recruitment, time commitment and coordination of faculty assessors. In this study, we evaluated the use of standardised clients (SC) as a viable option for assessing veterinary students' communication performance. We designed a four-station, two-track communication skills OSCE. SC assessors used an adapted nine-item Liverpool Undergraduate Communication Assessment Scale (LUCAS). Faculty used a 21-item checklist derived from the Calgary-Cambridge Guide (CCG) and a five-point global rating scale. Participants were second year veterinary students (n=96). For the four stations, intrastation reliability (α) ranged from 0.63 to 0.82 for the LUCAS, and 0.73 to 0.87 for the CCG. The interstation reliability coefficients were 0.85 for the LUCAS and 0.89 for the CGG. The calculated Generalisability (G) coefficients were 0.62 for the LUCAS and 0.60 for the CGG. Supporting construct validity, SC and faculty assessors showed a significant correlation between the LUCAS and CCG total percent scores (r=0.45, PStudy results support that SC assessors offer a reliable and valid approach for assessing veterinary communication OSCE. British Veterinary Association.

Novel zinc(II)phthalocyanines bearing azo-containing schiff base: Determination of pKa values, absorption, emission, enzyme inhibition and photochemical properties

Science.gov (United States)

Kantar, Cihan; Mavi, Vildan; Baltaş, Nimet; İslamoğlu, Fatih; Şaşmaz, Selami

2016-10-01

Azo-containing schiff bases are well known and there are many studies about their various properties in literature. However, phthalocyanines bearing azo-containing schiff bases, their spectral, analytical and biological properties are unknown. Therefore, new zinc (II) phthalocyanines bearing azo-containing schiff base were synthesized and investigated to determine pKa values, absorption, emission, enzyme inhibition and photochemical properties. Emission spectra were reported and large Stokes shift values were determined for all compounds, indicating that all molecules exhibit excited state intramolecular proton transfer. These phthalocyanines were the first examples of phthalocyanine showing excited state intramolecular proton transfer. Singlet oxygen quantum yields of zinc (II) phthalocyanines were determined. pKa values and indicator properties of all compounds were investigated by potentiometry. All compounds were assayed for inhibitory activity against bovine milk xanthine oxidase and acetylcholinesterase enzyme in vitro. Compound 2 showed the high inhibitory effect against xanthine oxidase (IC50 = 0.24 ± 0.01 μM). However, phthalocyanine compounds did not show enzyme inhibitor behavior.

An application of the coincidence Doppler spectroscopy for substances of chemical interest: phthalocyanine and acetylacetonate complexes

International Nuclear Information System (INIS)

Ito, Y.; Suzuki, T.

2000-01-01

Coincidence Doppler spectroscopy, which is particularly powerful when one is concerned with high momentum components of positron annihilation gamma-rays, has been applied to two different kinds of organo-metallic ligands: metal phthalocyanines and metal acetylacetonates. The energy (momentum) profiles of the annihilation gamma-rays were the same for metal phthalocyanines indicating that positron and/or positronium are not interacting with the metal ions. However, the profiles for the metal acetylacetonates evidently showed a dependence on the kind of metal ions. Discussion is made on the features of positron interaction which are different for phthalocyanines and acetylacetonates.

Electrochemistry and spectroelectrochemistry of tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine, Lu2Pc4 and dimeric lutetium(III) phthalocyanine, Lu2Pc2(OAc)2

International Nuclear Information System (INIS)

Koca, Atif; Ceyhan, Tanju; Erbil, Mehmet K.; Ozkaya, Ali Riza; Bekaroglu, Ozer

2007-01-01

In this study, electrochemical, electrochromic and spectroelectrochemical properties of a tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine (Lu 2 Pc 4 2) were investigated explicitly as compared with a tert-butylcalix[4]arene bridged dimeric lutetium(III) phthalocyanine [Lu 2 Pc 2 (OAc) 2 1]. Distinctive differences between electrochemical and electrochromic properties of 1 and 2 were detected. Moreover, the properties of 1 and 2 were compared with previously reported S 4 (CH 2 ) 4 bridged Lu 2 Pc 2 (OAc) 2 and Lu 2 Pc 4 . The calixarene bridged phthalocyanine (Pc) compounds, 1 and 2 showed well-defined electrochromic behaviour with green-blue and blue-purple colour transitions. The enhanced electrochromic properties of 2, as compared to 1, were attributed to its double-decker structure, probably allowing the formation of suitable ion channels for the counter ion movement in the solid film

Towards the anti-fibrillogenic activity of phthalocyanines with out-of-plane ligands: correlation with self-association proneness

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Kovalska V. B.

2013-11-01

Full Text Available Aim. The activity of five hafnium phthalocyanines containing out-of-plane ligands as inhibitors of reaction of insulin fibril formation is studied and correlation between their inhibitory properties and tendency to self-association is discussed. Methods. Fluorescence and absorption spectroscopy. Results. For the complexes with weak proneness to self-association PcHfDbm2, PcHfPyr2, and PcHfBtfa2 the values of inhibitory activity were estimated as 60–73 %. For phthalocyanines with the pronounced tendency to self-association PcHfPiromelit and PcHfCl2 the noticeably higher inhibitory activity values (about 95 % were shown. In the presence of native or fibrilar insulin the destruction of self-associates of metal complex occurs in buffer pH 7.9, Besides upon the conditions of insulin fibrillization reaction (0.1 M HCl phthalocyanines exist predominantly as monomers. Conclusions. The phthalocyanines with out-of-plane ligands with higher tendency to self-association have shown higher inhibitory activity in the insulin fibril formation comparing with the poorly aggregated metal complexes. At the same time low-order self-associates are not involved directly in the mechanism of inhibition of insulin fibrillization and the phthalocyanines bind with protein in monomeric form. Tendency of phthalocyanines to self-association in aqueous media seems to be an «indicator» of their proneness to stack with protein aromatic amino-acids and thus of anti-fibrilogenic properties.

Electronic structure, transport, and collective effects in molecular layered systems

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Torsten Hahn

2017-10-01

Full Text Available The great potential of organic heterostructures for organic device applications is exemplified by the targeted engineering of the electronic properties of phthalocyanine-based systems. The transport properties of two different phthalocyanine systems, a pure copper phthalocyanine (CoPc and a flourinated copper phthalocyanine–manganese phthalocyanine (F16CoPc/MnPc heterostructure, are investigated by means of density functional theory (DFT and the non-equilibrium Green’s function (NEGF approach. Furthermore, a master-equation-based approach is used to include electronic correlations beyond the mean-field-type approximation of DFT. We describe the essential theoretical tools to obtain the parameters needed for the master equation from DFT results. Finally, an interacting molecular monolayer is considered within a master-equation approach.

Active and passive control of zinc phthalocyanine photodynamics

NARCIS (Netherlands)

Sharma, Divya; Huijser, Jannetje Maria; Savolainen, Janne; Steen, Gerrit Willem; Herek, Jennifer Lynn

2013-01-01

In this work we report on the ultrafast photodynamics of the photosensitizer zinc phthalocyanine (ZnPc) and manipulation thereof. Two approaches are followed: active control via pulse shaping and passive control via strategic manipulation in the periphery of the molecular structure. The objective of

Kinetic of the Intracellular Incorporation of New Phthalocyanines Synthesized in mexico and Its Potential as Photosensibilizers in the Photodynamic Therapy

International Nuclear Information System (INIS)

Aragon-Aguilar, Hector; Ramon-Gallegos, Eva; Arenas-Huertero, Francisco Jesus; Contreras-Ramos, Alejandra; Cruz-Orea, Alfredo; Sosa-Sanchez, Jose Luis; Garcia Miranda, Maribel

2008-01-01

The search of more specific and efficient photosensitizer in low oxygen tensions is a need in the Photodynamic Therapy (PDT). Phthalocyanines have demonstrated to have the above mentioned activity. The aim of this work was to determine the efficiency of PDT using two phthalocyanines synthesized in Mexico to eliminate melanoma cells. B16F0 melanoma mouse cells were exposed to concentrations from 8.95x10 -5 to 0.733 m/mL of F16VoPc and F16NbPcC13 during 24h, afterwards cellular mortality was measured. One kinetic was realized to determine the intracellular incorporation of phthalocyanines by confocal microscopy at 1, 2, 4, 8, 16 and 24 h of exposition. The PDT was applied exposing the cells to innocuous concentration (that does not provoke cellular death with out irradiation) and irradiating with an argon laser at 100 J/cm 2 . For each phthalocyanine a control group was used; one group was not treated neither with light nor with phthalocyanine, the other group it was only irradiated. 24 h after treatment the citotoxicity was measured by Alamar blue assay. The innocuous concentration found for the phthalocyanines F16VoPc and F16NbPcC13 were 4.58x10-2 and 2.29xl0 -2 mg/mL, respectively. The time of maximum intracellular accumulation for both phthalocyanines was 24 h. Only the F16VoPc had anticancerous activity and induced 31.7% of cellular death. The PDT might offer a potential alternative to the treatment of this cancer when is used the phthalocyanine F16VoPc

Synthesis of the iron phthalocyaninate radical cation μ-nitrido dimer and its interaction with hydrogen peroxide

Science.gov (United States)

Grishina, E. S.; Makarova, A. S.; Kudrik, E. V.; Makarov, S. V.; Koifman, O. I.

2016-03-01

The iron phthalocyaninate μ-nitrido dimer radical cation, as well as the μ-nitrido dimer complexes of iron phthalocyaninate, was found to have high catalytic activity in the oxidation of organic compounds. It was concluded that this compound is of interest as a model of active intermediates—catalase and oxidase enzymes.

Immobilization of Zinc Phthalocyanines in Silicate Matrices and Investigation of Their Photobactericidal Effect on E.coli

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Spas Artarsky

2006-01-01

Full Text Available The aim of the present investigation was to immobilize zinc phthalocyanines in a silicate matrix and to test the photobactericidal properties of the matrices so prepared toward Esherichia coli in model aqueous media. For the purpose, tetra tertiary butyl zinc phthalocyanine (TBZnPc and zinc phthalocyanine tetrasulfonic acid (ZnPcTS were used. The abilities of these two photosensitizers to generate singlet oxygen in solution were compared by following the rate of photobleaching of 1,3-diphenylisobenzofuran (DPBF at 430 nm in dimethylformamide (DMF.The results of this study show clearly that, under the conditions used here, the TBZnPc is the more effective generator of singlet oxygen; with it the DPBF was virtually completely photobleached in 4 min, while with the ZnPcTS under the same conditions, it took 12 min to reach this point. Glass conjugates with the two phthalocyanines were obtained by the sol-gel technique and were characterized by a well-defined color due to the phthalocyanine incorporated in the silicate matrix. Glasses with an intense, but inhomogeneous, green color were obtained when the tetrasulfonic derivative of the zinc phthalocyanine was used, while blue glasses of evenly distributed coloration were formed from the tetra tertiary butyl derivative.The ZnPcTS conjugate demonstrates more effective singlet oxygen evolution than is the case with the TBZnPc conjugate. These results are the opposite of those obtained for the free phthalocyanines in solution. The structural formulae of the compounds show that TBZnPc has a more pronounced hydrophobic character than the sulfonic derivative. In our view, the relative reactivities of the conjugates can be explained by the tetrasulfonic derivative being situated mainly in the surface parts of the glass matrix where the hydrophilic character is prevailing, while the tertiary butyl derivative is mainly present in the internal parts of the matrix as a result of which it is less accessible and

Assessing nursing clinical skills competence through objective structured clinical examination (OSCE) for open distance learning students in Open University Malaysia.

Science.gov (United States)

Oranye, Nelson Ositadimma; Ahmad, Che'an; Ahmad, Nora; Bakar, Rosnida Abu

2012-06-01

The objective structured clinical skills examination (OSCE) has over the years emerged as a method of evaluating clinical skills in most medical and allied professions. Although its validity and objectivity has evoked so much debate in the literature, little has been written about its application in non-traditional education systems such as in distance learning. This study examined clinical skills competence among practising nursing students who were enrolled in a distance learning programme. The study examined the effect of work and years of nursing practice on nurses' clinical skills competence. This study used observational design whereby nursing students' clinical skills were observed and scored in five OSCE stations. Two instruments were used for the data collection - A self-administered questionnaire on the students' bio-demographic data, and a check list on the clinical skills which the examiners rated on a four point scale. The findings revealed that 14% of the nurses had level four competence, which indicated that they could perform the tasks correctly and complete. However, 12% failed the OSCE, even though they had more than 10 years experience in nursing and post basic qualifications. Inter-rater reliability was 0.92 for the five examiners. Factor analysis indicated that five participant factors accounted for 74.1% of the variations in clinical skills performance. An OSCE is a necessary assessment tool that should be continuously applied in nursing education, regardless of the mode of the education program, the student's years of experience or his/her clinical placement. This study validates the need for OSCE in both the design of tertiary nursing degree programs and the assessment of nurses' clinical competency level.

Synthesis and electrochemical and in situ spectroelectrochemical characterization of manganese, vanadyl, and cobalt phthalocyanines with 2-naphthoxy substituents

International Nuclear Information System (INIS)

Ozcesmeci, Ibrahim; Koca, Atif; Guel, Ahmet

2011-01-01

Highlights: → Metallo (Mn, Co, VO) phthalocyanines bearing peripheral 2-naphthoxy-groups were synthesized by cyclotetramerisation of the corresponding phthalonitrile derivative. → Incorporation of the redox active metal ions into the phthalocyanine core extends the redox capabilities of the Pc ring. → The presence of O 2 in the electrolyte system influences both oxygen reduction reaction and the electrochemical and spectral behaviors of the complexes. → Homogeneous catalytic ORR process occurs via an 'inner sphere' chemical catalysis process. - Abstract: Metallo (Mn, Co, VO) phthalocyanines bearing peripheral 2-naphthoxy groups were synthesized by cyclotetramerisation of the corresponding phthalonitrile derivative. The phthalocyanine compounds were characterized by elemental analyses, mass, FT-IR and UV-vis spectral data. Three intense bands in the electronic spectra clearly indicate the absorptions resulting from naphthyl groups along with the Q and B bands of the phthalocyanines. Electrochemical and spectroelectrochemical measurements exhibit that incorporation of redox active metal ions, Co II and Mn III , into the phthalocyanine core extends the redox capabilities of the Pc ring including the metal-based reduction and oxidation couples of the metal. Presence of molecular oxygen in the electrolyte system affects the voltammetric and spectroelectrochemical responses of the cobalt and manganese phthalocyanines due to the interaction between the complexes and molecular oxygen. Interaction reaction of oxygen with CoPc occurs via an 'inner sphere' chemical catalysis process. While CoPc gives the intermediates [O 2 - -Co II Pc -2 ] - and [O 2 2 -Co II Pc -2 ] 2- , MnPc forms μ-oxo MnPc species. An in situ electrocolorimetric method has been applied to investigate the color of the electro-generated anionic and cationic forms of the complexes for possible electrochromatic applications.

Wahlfach Teamarbeit: Ergebnisse eines Pilotprojektes zur interprofessionellen und interdisziplinären Ausbildung mit formativem Team-OSCE (TOSCE [Teamwork elective: Results of a German pilot project on interprofessional and interdisciplinary education with formative team OSCE

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Schmidt, Anita

2010-08-01

Full Text Available [english] Aims: There is a growing need to implement teamworking in medical education. In reality, interdisciplinary and interprofessional education is often absent. Here we describe a pilot trial developed jointly by the nursing college and the medical faculty in Erlangen (Germany in which nursing students and undergraduate medical students formed interprofessional teams and were confronted with interprofessional cases using simulated patients (SPs and phantoms. The elective was planned using standard curriculum planning instruments and finally evaluated with a novel formative team OSCE (Objective Structured Clinical Evaluation instrument.Methods: During one year, 20 nursing students participated voluntarily in the project and 10 medical students took the course as an elective. Results: The pilot project was first performed with two tutors, one from the medical school and one from the nursing school, as well as one to two SPs. During the second course, there was only one tutor. Overall evaluation of the voluntary students was good, with some elements (acute stroke, factual knowledge, and general organizational problems that needed to be improved. Performance of a four-station team OSCE was feasible, but raters reported problems in assessing individuals and the team at the same time. Interobserver agreement was satisfactory (kappa 0.35.Conclusions: Interdisciplinary and interprofessional education between a nursing school and a medical school is feasible within an elective, but requires substantial personnel resources. Design and performance of a team OSCE is possible. The validity of the test has to be shown on follow-up.[german] Zielsetzung: Das Lernziel „Fähigkeit zur interprofessionellen und interdisziplinären Teamarbeit“ wird sowohl in der aktuellen Approbationsordnung für Ärzte als auch im Krankenpflegegesetz gefordert. In der Realität gibt es in beiden Ausbildungen kaum gemeinsame Lehreinheiten. Wir beschreiben ein Pilotprojekt

Dynamical propagation of nanosecond pulses in Naphthalocyanines and Phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Miao, Quan, E-mail: qmiao2013@yahoo.com [College of Electronics, Communication and Physics, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); Liang, Min; Liu, Qixin [College of Electronics, Communication and Physics, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); Wang, Jing-Jing [College of Electronics, Communication and Physics, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); Sun, Erping; Xu, Yan [College of Electronics, Communication and Physics, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, Shandong (China)

2016-11-30

Highlights: • We study the dynamical processes of nanoseconds lasers in Naphthalocyanines and Phthalocyanines. • We provide theoretical evidences of the main mechanism of optical power limiting. • The central metals play more important roles in the dynamical processes. • The main reason is the central metals enhance the spin–orbit coupling. - Abstract: Dynamical propagation and optical limiting of nanosecond pulses in peripherally substituted Naphthalocyanines (Npcs) and Phthalocyanines (Pcs) with central metals gallium and indium were theoretically studied using paraxial field and rate equations. The results demonstrated that both Npcs and Pcs have good optical limiting performances, and Npc with heavier central mental indium shows better optical limiting properities due to the stronger reverse saturable absorption, which is mainly strengthened by the larger one-photo absorption cross section of excited state and the faster intersystem crossing rate.

Supramolecular Structure, Physical Properties, and Langmuir-Blodgett Film Formation of an Optically Active Liquid-Crystalline Phthalocyanine

NARCIS (Netherlands)

Nostrum, Cornelus F. van; Bosman, Anton W.; Gelinck, Gerwin H.; Schouten, Pieter G.; Warman, John M.; Devillers, Marinus A.C.; Meijerink, Andries; Picken, Stephen J.; Sohling, Ulrich; Schouten, Arend-Jan; Nolte, Roeland J.M.

The structure and physical properties of optically active, metal-free 2,3,9,10,16,17,23,24-octa(S-3,7-dimethyloctoxy)phthalocyanine ((S)-Pc(8,2)) are reported and compared with those of the phthalocyanine with (R,S) side chains (mixture of 43 stereoisomers). Unlike the latter compound, (S)-Pc(8,2)

OSCE para Competências de Comunicação Clínica e Profissionalismo: Relato de Experiência e Meta-Avaliação

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Camila Ament Giuliani dos Santos Franco

Full Text Available RESUMO A comunicação clínica e o profissionalismo estão entre as principais competências médicas e, portanto, devem ter sua avaliação garantida. Nesse contexto, o exame clínico objetivo estruturado (OSCE tem papel fundamental. Objetivos Descrever as etapas de elaboração de um OSCE, bem como a avaliação da qualidade das estações e a percepção do estudante de Medicina sobre a sua realização. Método O estudo é composto pela realização de um OSCE com quatro estações por 16 estudantes de Medicina e pela análise da qualidade psicométrica e aplicação de um questionário de satisfação. Resultados Para os estudantes, o OSCE é o método que melhor avalia e ensina essas competências, ao passo que os testes de múltipla escolha estão no polo oposto quanto à avaliação. Em relação à qualidade múltipla das estações: duas se apresentaram com boa confiabilidade, uma se tornou satisfatória após adequação e uma se revelou inconsistente. Conclusão Mesmo bem avaliadas pelos estudantes, algumas estações apresentaram falhas. A análise do OSCE é fundamental para sua validade e mensurabilidade, em especial para o OSCE de alta aposta.

Synthesis, characterization, photophysical, and photochemical properties of novel zinc(II) and indium(III) phthalocyanines containing 2-phenylphenoxy units

Energy Technology Data Exchange (ETDEWEB)

Ali, Haytham Elzien Alamin [Department of Chemistry, Marmara University, Istanbul 34722 (Turkey); University of Khartoum, Department of Chemistry, Faculty of Science, P.O. Box 321, Khartoum, 11115 (Sudan); Pişkin, Mehmet [Çanakkale Onsekiz Mart University, Vocational School of Technical Sciences, Department of Food Technology, Çanakkale 17100 (Turkey); Altun, Selçuk [Department of Chemistry, Marmara University, Istanbul 34722 (Turkey); Durmuş, Mahmut [Gebze Technical University, Department of Chemistry, P.O. Box 141, Gebze, Kocaeli 41400 (Turkey); Odabaş, Zafer, E-mail: zodabas@marmara.edu.tr [Department of Chemistry, Marmara University, Istanbul 34722 (Turkey)

2016-05-15

The synthesis of highly soluble and non-aggregated peripherally/non-peripherally Zn and In(OAc) phthalocyanines was achieved by 3-/ and 4-(2-phenylphenoxy)phthalonitrile as starting materials. The novel compounds were characterized by elemental analyses, FT-IR, {sup 1}H-NMR (for phthalonitriles), UV–vis and MALDI-TOF mass (for Pcs) spectroscopic techniques. Additionally, photophysical, photochemical and spectral properties of the phthalocyanines were reported. Especially, the indium(OAc) phthalocyanines showed good singlet oxygen quantum yields in DMSO and they can be appropriate candidates as Type II photosensitizers in photodynamic therapy (PDT) applications.

Synthesis, characterization, photophysical, and photochemical properties of novel zinc(II) and indium(III) phthalocyanines containing 2-phenylphenoxy units

International Nuclear Information System (INIS)

Ali, Haytham Elzien Alamin; Pişkin, Mehmet; Altun, Selçuk; Durmuş, Mahmut; Odabaş, Zafer

2016-01-01

The synthesis of highly soluble and non-aggregated peripherally/non-peripherally Zn and In(OAc) phthalocyanines was achieved by 3-/ and 4-(2-phenylphenoxy)phthalonitrile as starting materials. The novel compounds were characterized by elemental analyses, FT-IR, 1 H-NMR (for phthalonitriles), UV–vis and MALDI-TOF mass (for Pcs) spectroscopic techniques. Additionally, photophysical, photochemical and spectral properties of the phthalocyanines were reported. Especially, the indium(OAc) phthalocyanines showed good singlet oxygen quantum yields in DMSO and they can be appropriate candidates as Type II photosensitizers in photodynamic therapy (PDT) applications.

A Comparison of Standard-Setting Procedures for an OSCE in Undergraduate Medical Education.

Science.gov (United States)

Kaufman, David M.; Mann, Karen V.; Muijtjens, Arno M. M.; van der Vleuten, Cees P. M.

2000-01-01

Compared four standard-setting procedures for an objective structure clinical examination (OSCE) in medical education. Applied Angoff, borderline, relative, and holistic procedures to the data used to establish a cutoff score for a pass/fail decision. The Angoff and borderline procedures gave similar results; however, the relative and holistic…

Novel homo- and heterobinuclear ball-type phthalocyanines: synthesis and electrochemical, electrical, EPR and MCD spectral properties.

Science.gov (United States)

Odabaş, Zafer; Dumludağ, Fatih; Ozkaya, Ali Riza; Yamauchi, Seigo; Kobayashi, Nagao; Bekaroğlu, Ozer

2010-09-21

The mononuclear Fe(II) phthalocyanine 2 and ball-type homobinuclear Fe(II)-Fe(II) and Cu(II)-Cu(II) phthalocyanines, 3 and 4 respectively, were synthesized from the corresponding 4,4'-[1,1'-methylenebis-(naphthalene-2,1-diyl)]bis(oxy)diphthalonitrile 1, and then ball-type heterobinuclear Fe(II)-Cu(II) phthalocyanine 5 was synthesized from 2. The novel compounds 4 and 5 have been characterized by elemental analysis, UV/vis, IR and MALDI-TOF mass spectroscopies. Electron paramagnetic resonance and magnetic circular dichroism measurements of 3, 4 and 5 were also examined. The voltammetric measurements of the complexes showed the formation of various electrochemically stable ligand- and metal-based mixed-valence species, due to the intramolecular interactions between the two MPc units, especially in ball-type binuclear iron(II) phthalocyanine. Impedance spectroscopy and d.c. conductivity measurements of 4 and 5 were performed as a function of temperature (295-523 K) and frequency (40-10(5) Hz). While room temperature impedance spectra consist of a curved line, a transformation into a full semicircle with increasing temperature was observed for both compounds.

Objective Structured Clinical Examinations (OSCEs, psychiatry and the Clinical assessment of Skills and Competencies (CASCSame Evidence, Different Judgement

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Marwaha Steven

2011-05-01

Full Text Available Abstract Background The Objective Structured Clinical Examination (OSCE, originally developed in the 1970's, has been hailed as the "gold standard" of clinical assessments for medical students and is used within medical schools throughout the world. The Clinical assessment of Skills and Competencies (CASC is an OSCE used as a clinical examination gateway, granting access to becoming a senior Psychiatrist in the UK. Discussion Van der Vleuten's utility model is used to examine the CASC from the viewpoint of a senior psychiatrist. Reliability may be equivalent to more traditional examinations. Whilst the CASC is likely to have content validity, other forms of validity are untested and authenticity is poor. Educational impact has the potential to change facets of psychiatric professionalism and influence future patient care. There are doubts about acceptability from candidates and more senior psychiatrists. Summary Whilst OSCEs may be the best choice for medical student examinations, their use in post graduate psychiatric examination in the UK is subject to challenge on the grounds of validity, authenticity and educational impact.

Zinc phthalocyanine thin film and chemical analyte interaction studies by density functional theory and vibrational techniques

International Nuclear Information System (INIS)

Saini, G S S; Singh, Sukhwinder; Kumar, Ranjan; Tripathi, S K; Kaur, Sarvpreet; Sathe, Vasant

2009-01-01

Thin films of zinc phthalocyanine have been deposited on KBr and glass substrates by the thermal evaporation method and characterized by the x-ray diffraction, optical, infrared and Raman techniques. The observed x-ray diffraction and infrared absorption spectra of as-deposited thin films suggest the presence of an α crystalline phase. Infrared and Raman spectra of thin films after exposure to vapours of ammonia and methanol have also been recorded. Shifts in the position of some IR and Raman bands in the spectra of exposed films have been observed. Some bands also show changes in their intensity on exposure. Increased charge on the phthalocyanine ring and out-of-plane distortion of the core due to interaction between zinc phthalocyanine and vapour molecules involving the fifth coordination site of the central metal ion may be responsible for the band shifts. Changes in the intensity of bands are interpreted in terms of the lowering of molecular symmetry from D 4h to C 4v due to doming of the core. Molecular parameters and Mulliken atomic charges of zinc phthalocyanine and its complexes with methanol and ammonia have been calculated from density functional theory. The binding energy of the complexes have also been calculated. Calculated values of the energy for different complexes suggest that axially coordinated vapour molecules form the most stable complex. Calculated Mulliken atomic charges show net charge transfer from vapour molecules to the phthalocyanine ring for the most stable complex.

Production of nuclear ceramic fuel for nuclear power plants at 'Ulba metallurgical plant' OSC

International Nuclear Information System (INIS)

Khadeev, V.G.

2000-01-01

The paper describes the flow-sheet of production of uranium dioxide powders and nuclear ceramic fuel pellets of them existing at the facility. 'UMP' OSC applies ADU extraction process of UO2 powders production. An indisputable success of the process is the possibility of use of the wide range of raw materials. Uranium hexafluoride, uranium oxides, uranium metal, uranium tetrafluoride, uranyl salts, uranium ore concentrates, all possible types of uranium-containing materials the processing of which by routine methods is difficult (ashes, scraps, etc.) are used as the raw materials. In addition, a reprocessed nuclear fuel can be used for fuel production. The quality of uranium dioxide powder produced does not depend on the type of uranium raw material used. High selectivity of extraction refining makes possible to obtain material with rather low impurities content that meets practically all specifications for uranium dioxide known to us. Ceramic and process features of uranium dioxide powders, namely, specific surface, bulk density, grain size and sinterability make possible to produce nuclear ceramic fuel with specified features. Quality of uranium dioxide powders produced by 'UMP' OSC was highly rated by General Electric company that is one of the leading companies from fuel manufactures in the USA market . It has certified 'UMP' OSC as its supplier. Currently, our company makes great efforts on establishing production of uranium dioxide powders with natural isotopes content for production of fuel for CANDU reactors. Trial lots of such powders are under tests at some companies manufacturing fuel for this type reactors in Canada, USA and Corea

77 FR 28638 - OSC Forms And Survey Renewal for FY 2012-Request for Comment

Science.gov (United States)

2012-05-15

... employees; and (2) the interpretation and enforcement of Hatch Act provisions on political activity in... Possible Prohibited Political Activity (Violation of the Hatch Act)); (4) Office of Special Counsel (OSC... seeking assistance was fully apprised of their rights; (2) determine whether the individual was successful...

Zinc Phthalocyanine Labelled Polyethylene Glycol: Preparation, Characterization, Interaction with Bovine Serum Albumin and Near Infrared Fluorescence Imaging in Vivo

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Tianjun Liu

2012-05-01

Full Text Available Zinc phthalocyanine labelled polyethylene glycol was prepared to track and monitor the in vivo fate of polyethylene glycol. The chemical structures were characterized by nuclear magnetic resonance and infrared spectroscopy. Their light stability and fluorescence quantum yield were evaluated by UV-Visible and fluorescence spectroscopy methods. The interaction of zinc phthalocyanine labelled polyethylene glycol with bovine serum albumin was evaluated by fluorescence titration and isothermal titration calorimetry methods. Optical imaging in vivo, organ aggregation as well as distribution of fluorescence experiments for tracking polyethylene glycol were performed with zinc phthalocyanine labelled polyethylene glycol as fluorescent agent. Results show that zinc phthalocyanine labelled polyethylene glycol has good optical stability and high emission ability in the near infrared region. Imaging results demonstrate that zinc phthalocyanine labelled polyethylene glycol can track and monitor the in vivo process by near infrared fluorescence imaging, which implies its potential in biomaterials evaluation in vivo by a real-time noninvasive method.

Communication Skills assessed at OSCE are not affected by Participation in the Adolescent Healthy Sexuality Program

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Deborah Penava

2002-12-01

Full Text Available We proposed that first year medical students who voluntarily participated in the Healthy Sexuality adolescent program would perform better than their peers on an adolescent counseling station at the year-end OSCE (Objective Structured Clinical Examination. In addition we compared medical students’ communication skills at the time of the program as assessed by self, peers and participating adolescents. Methods: Nineteen first year medical students voluntarily participated in the ongoing Healthy Sexuality program. Adolescent participants, medical student peer participants and medical students assessed communication components on a 7-point Likert scale at the end of the program. At the year-end OSCE, all first year medical students at the University of Western Ontario were assessed at an adolescent counseling station by a standardized patient (SP and a physician examiner. Statistical analysis examined differences between the two groups. Results: Students who participated in the Healthy Sexuality program did not perform better than their colleagues on the year-end OSCE. A statistically significant correlation between physician examiner and SP evaluations was found (r = 0.62. Adolescent participants communication skills assessments in the Healthy Sexuality Program demonstrated no significant correlation with medical student assessments (self or peer. Conclusions:Voluntary intervention with adolescents did not result in improved communication skills at the structured year-end examination. Further investigation will be directed towards delineating differences between SP and physician examiner assessments.

Synthesis and Supramolecular Chemistry of Novel Liquid Crystalline Crown Ether-Substituted Phthalocyanines : Toward Molecular Wires and Molecular Ionoelectronics

NARCIS (Netherlands)

Nostrum, Cornelus F. van; Picken, Stephen J.; Schouten, Arend-Jan; Nolte, Roeland J.M.

1995-01-01

The synthesis of the metal-free and the dihydroxysilicon derivatives of tetrakis[4’,5’-bis(decoxy)benzo-18-crown-6]phthalocyanine is described. The metal-free phthalocyanine is liquid crystalline and exhibits a crystalline phase to mesophase transition at 148 °C. The structures of the crystalline

The quality of feedback during formative OSCEs depends on the tutors’ profile

Directory of Open Access Journals (Sweden)

Noelle Junod Perron

2016-11-01

Full Text Available Abstract Background During their pre-clinical years, medical students are given the opportunity to practice clinical skills with simulated patients. During these formative objective structured clinical encounters (OSCEs, tutors from various backgrounds give feedback on students’ history taking, physical exam, and communication skills. The aim of the study was to evaluate whether the content and process of feedback varied according to the tutors’ profile. Methods During 2013, all 2nd and 3rd year medical students and tutors involved in three formative OSCEs were asked to fill in questionnaires, and their feedback sessions were audiotaped. Tutors were divided into two groups: 1 generalists: primary care, general internist and educationalist physicians 2 specialists involved in the OSCE related to their field of expertise. Outcome measures included the students’ perceptions of feedback quality and utility and objective assessment of feedback quality. Results Participants included 251 medical students and 38 tutors (22 generalists and 16 specialists. Students self-reported that feedback was useful to improve history taking, physical exam and communication skills. Objective assessment showed that feedback content essentially focused on history taking and physical exam skills, and that elaboration on clinical reasoning or communication/professionalism issues was uncommon. Multivariate analyses showed that generalist tutors used more learner-centered feedback skills than specialist tutors (stimulating student’s self-assessment (p < .001; making the student active in finding solutions, p < .001; checking student’s understanding, p < .001 and elaborated more on communication and professionalism issues (p < 0.001. Specialists reported less training in how to provide feedback than generalists. Conclusion These findings suggest that generalist tutors are more learner-centered and pay more attention to communication and

Electronic structures and magnetic/optical properties of metal phthalocyanine complexes

Energy Technology Data Exchange (ETDEWEB)

Baba, Shintaro; Suzuki, Atsushi, E-mail: suzuki@mat.usp.ac.jp; Oku, Takeo [Department of Materials Science, The University of Shiga Prefecture. 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

2016-02-01

Electronic structures and magnetic / optical properties of metal phthalocyanine complexes were studied by quantum calculations using density functional theory. Effects of central metal and expansion of π orbital on aromatic ring as conjugation system on the electronic structures, magnetic, optical properties and vibration modes of infrared and Raman spectra of metal phthalocyanines were investigated. Electron and charge density distribution and energy levels near frontier orbital and excited states were influenced by the deformed structures varied with central metal and charge. The magnetic parameters of chemical shifts in {sup 13}C-nuclear magnetic resonance ({sup 13}C-NMR), principle g-tensor, A-tensor, V-tensor of electric field gradient and asymmetry parameters derived from the deformed structures with magnetic interaction of nuclear quadruple interaction based on electron and charge density distribution with a bias of charge near ligand under crystal field.

Layer-by-layer construction of graphene/cobalt phthalocyanine composite film on activated GCE for application as a nitrite sensor

International Nuclear Information System (INIS)

Cui, Lili; Pu, Tao; Liu, Ying; He, Xingquan

2013-01-01

Graphical abstract: A novel nitrite sensor was prepared by using LBL technique which for the first time used the activated positively charged glassy carbon electrode (A-GCE) as the substrate. The nitrite sensor shows super stability for consecutive CV testing and rather low detection limit. -- Abstract: In this paper, a novel graphene/cobalt phthalocyanine composite film was prepared by layer-by-layer (LBL) technique which for the first time used the activated positively charged glassy carbon electrode (A-GCE) as the substrate. The surface morphology of graphene/cobalt phthalocyanine composite film was characterized by scanning electron microscopy (SEM) and atomic force microscope (AFM). It is found that graphene/cobalt phthalocyanine composite film modified GCE exhibits good catalytic activity toward the oxidation of nitrite. The oxidation current barely decreases in consecutive CV test. Furthermore, the modified GCE shows long-term stability after 70 days. The super good stability can be attributed to the immobilization and dispersion of electroactive cobalt phthalocyanine by graphene, and using A-GCE as substrate which can enhance the interaction force between GCE and electroactive cobalt phthalocyanine. The nitrite sensor shows rather low detection limit of 0.084 μM at a signal-to-noise ratio = 3 (S/N = 3)

High-resolution spectroscopy in superfluid helium droplets. Investigation of vibrational fine structures in electronic spectra of phthalocyanine and porphyrin derivatives

Energy Technology Data Exchange (ETDEWEB)

Riechers, Ricarda Eva Friederike Elisabeth

2011-03-22

Since a considerably large variety of substituted compounds is commercially available and the electronic excitation spectra fit well into the spectral range covered by the continuous wave dye laser used for this study several porphyrin and phthalocyanine derivatives substituted with different types and numbers of alkyl and aryl groups were chosen as molecular probes. Recording fluorescence excitation and dispersed emission spectra revealed exclusively sharp transitions for all species. A change of the molecule's electrostatic moments, primarily and most effectively, a change of the molecular dipole moment regarding both magnitude and orientation, was identified as the main contribution for line broadening effects. Apart from the sharp lines presented in their fluorescence excitation spectra, the phthalocyanine derivatives investigated for this study, namely chloro-aluminium-phthalocyanine (AlClPc) and tetra-tertbutyl-phthalocyanine (TTBPc), exhibited more than one emission spectrum.

High-resolution spectroscopy in superfluid helium droplets. Investigation of vibrational fine structures in electronic spectra of phthalocyanine and porphyrin derivatives

International Nuclear Information System (INIS)

Riechers, Ricarda Eva Friederike Elisabeth

2011-01-01

Since a considerably large variety of substituted compounds is commercially available and the electronic excitation spectra fit well into the spectral range covered by the continuous wave dye laser used for this study several porphyrin and phthalocyanine derivatives substituted with different types and numbers of alkyl and aryl groups were chosen as molecular probes. Recording fluorescence excitation and dispersed emission spectra revealed exclusively sharp transitions for all species. A change of the molecule's electrostatic moments, primarily and most effectively, a change of the molecular dipole moment regarding both magnitude and orientation, was identified as the main contribution for line broadening effects. Apart from the sharp lines presented in their fluorescence excitation spectra, the phthalocyanine derivatives investigated for this study, namely chloro-aluminium-phthalocyanine (AlClPc) and tetra-tertbutyl-phthalocyanine (TTBPc), exhibited more than one emission spectrum.

Photosensitive heterostructures made of sulfonamide zinc phthalocyanine and organic semiconductor

Czech Academy of Sciences Publication Activity Database

Lutsyk, P.; Vertsimakha, Ya.; Nešpůrek, Stanislav; Pomaz, I.

2011-01-01

Roč. 535, - (2011), s. 18-29 ISSN 1542-1406 Institutional research plan: CEZ:AV0Z40500505 Keywords : heterostructure * reversal of sign in photovoltage spectra * sulphonamide-substituted phthalocyanine Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.580, year: 2011

Effect of iodine doping of phthalocyanine on the photocurrent generation in a phthalocyanine/C_<60> heterojunction

OpenAIRE

Mizuta, Shinsei; Iyota, Masatoshi; Tanaka, Senku; Hiromitsu, Ichiro

2012-01-01

Photocurrent generation in an indium?tin oxide (ITO)/iodine-doped Ni-phthalocyanine (NiPc-I_x)/C_/In/Al heterojunction device with x～1 was studied. By keeping the device in air after preparation, the device slowly reached a stationary state in which the sign of the photocurrent is opposite to that of a non-doped ITO/NiPc/C_/In/Al device although the rectification direction for the dark current is the same. By a simulation of incident photon-to-current conversion efficiency spectra and a measu...

Photophysicochemical, calf thymus DNA binding and in vitro photocytotoxicity properties of tetra-morpholinoethoxy-substituted phthalocyanines and their water-soluble quaternized derivatives.

Science.gov (United States)

Koçan, Halit; Kaya, Kerem; Özçeşmeci, İbrahim; Sesalan, B Şebnem; Göksel, Meltem; Durmuş, Mahmut; Burat, Ayfer Kalkan

2017-12-01

In this study, morpholinoethoxy-substituted metal-free (3), zinc(II) (4) and indium(III) (5) phthalocyanines were synthesized. These phthalocyanines were converted to their water-soluble quaternized derivatives (3Q-5Q) using excess methyl iodide as a quaternization agent. All these phthalocyanines (Pcs) were characterized by elemental analysis and different spectroscopic methods such as FT-IR, 1 H NMR, UV-Vis and mass spectrometry. The photophysical and photochemical properties such as fluorescence and generation of singlet oxygen were investigated for determination of these phthalocyanines as photosensitizers in photodynamic therapy (PDT) applications. The binding properties of quaternized phthalocyanines (3Q-5Q) to calf thymus DNA (CT-DNA) were investigated by UV-Vis and fluorescence spectrophotometric methods. The quenching effect of all quaternized phthalocyanines on the fluorescence intensity of SYBR Green-DNA complex was determined. The mixtures of 3Q, 4Q or 5Q and DNA solutions were used to determine the change in T m of double helix DNA with thermal denaturation profile. In addition, thermodynamic parameters considering their aggregation in buffer solution, which shows the spontaneity of the reactions between DNA and quaternized Pcs were investigated. On the other hand, in vitro phototoxicity and cytotoxicity behavior of the quaternized water-soluble phthalocyanine photosensitizers (3Q-5Q) were tested against the cervical cancer cell line named HeLa for evaluation of their suitability for treatment of cancer by PDT method. Peripherally tetra-substituted neutral and quaternized metal-free and metallophthalocyanines (MPcs) (Zn, In) bearing morpholinoethoxy groups were prepared. The binding of quaternized compounds (3Q-5Q) to CT-DNA were examined using UV-Vis, fluorescence spectra, thermal denaturation profiles and K SV values. Besides, thermodynamic studies indicated that binding of 3Q-5Q to DNA was spontaneous. On the other hand, in vitro phototoxicity and

Enhanced power conversion efficiency of p-i-n type organic solar cells by employing a p-layer of palladium phthalocyanine

KAUST Repository

Kim, Inho; Haverinen, Hanna M.; Li, Jian; Jabbour, Ghassan E.

2010-01-01

We demonstrate an enhancement in the power conversion efficiency (PCE) of p-i-n type organic solar cells consisting of zinc phthalocyanine (ZnPc) and fullerene (C60) using a p-layer of palladium phthalocyanine (PdPc). Solar cells employing three

Optimized adsorption of sulfonated phthalocyanines on ZnO electrodes and their characterization in dye- sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Falgenhauer, Jane; Loewenstein, Thomas; Schlettwein, Derck [Institute of Applied Physics, Justus-Liebig-University Giessen (Germany)

2010-07-01

Phthalocyanines belong to the most stable industrial dyes and show some of the highest molar extinction coefficients in the visible range. ZnO is known as a wide band gap semiconductor material which can be conveniently prepared as a porous electrode from solution-based processes. Sulfonated phthalocyanines were adsorbed at such electrodeposited porous ZnO thin films to work as a photosensitizer in a dye sensitized solar cell (DSSC). The adsorption solution of the phthalocyanine was modified in its composition and by adding different detergents in different concentrations. The adsorption solutions and the sensitized ZnO films were investigated by UV/Vis spectroscopy to characterize the aggregation of the dye molecules. Most of the detergents used could minimize the aggregation of the dye molecules in the adsorption solution without hindering the adsorption of the phthalocyanine on the ZnO surface. The photoelectrochemical characteristics of the resulting test cells were determined using a standard liquid electrolyte. The efficiency of the cells did not reach the expected level and reasons for this are discussed based on film morphology, amount of adsorbed dye molecules, competition by detergent adsorption, the optical absorbance of the dyes in the film and aggregate formation.

In situ metalation of free base phthalocyanine covalently bonded to silicon surfaces

Directory of Open Access Journals (Sweden)

Fabio Lupo

2014-11-01

Full Text Available Free 4-undecenoxyphthalocyanine molecules were covalently bonded to Si(100 and porous silicon through thermic hydrosilylation of the terminal double bonds of the undecenyl chains. The success of the anchoring strategy on both surfaces was demonstrated by the combination of X-ray photoelectron spectroscopy with control experiments performed adopting the commercially available 2,3,9,10,16,17,23,24-octakis(octyloxy-29H,31H-phthalocyanine, which is not suited for silicon anchoring. Moreover, the study of the shape of the XPS N 1s band gave relevant information on the interactions occurring between the anchored molecules and the substrates. The spectra suggest that the phthalocyanine ring interacts significantly with the flat Si surface, whilst ring–surface interactions are less relevant on porous Si. The surface-bonded molecules were then metalated in situ with Co by using wet chemistry. The efficiency of the metalation process was evaluated by XPS measurements and, in particular, on porous silicon, the complexation of cobalt was confirmed by the disappearance in the FTIR spectra of the band at 3290 cm−1 due to –NH stretches. Finally, XPS results revealed that the different surface–phthalocyanine interactions observed for flat and porous substrates affect the efficiency of the in situ metalation process.

A Procedural Skills OSCE: Assessing Technical and Non-Technical Skills of Internal Medicine Residents

Science.gov (United States)

Pugh, Debra; Hamstra, Stanley J.; Wood, Timothy J.; Humphrey-Murto, Susan; Touchie, Claire; Yudkowsky, Rachel; Bordage, Georges

2015-01-01

Internists are required to perform a number of procedures that require mastery of technical and non-technical skills, however, formal assessment of these skills is often lacking. The purpose of this study was to develop, implement, and gather validity evidence for a procedural skills objective structured clinical examination (PS-OSCE) for internal…

Fabrication and characterization of inverted organic solar cells using shuttle cock-type metal phthalocyanine and PCBM:P3HT

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Atsushi, E-mail: suzuki@mat.usp.ac.jp; Furukawa, Ryo, E-mail: suzuki@mat.usp.ac.jp; Akiyama, Tsuyoshi, E-mail: suzuki@mat.usp.ac.jp; Oku, Takeo, E-mail: suzuki@mat.usp.ac.jp [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

2015-02-27

Inverted organic solar cells using shuttle cock-type phthalocyanine, semiconducting polymer and fullerenes were fabricated and characterized. Photovoltaic and optical properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristics. The photovoltaic properties of the tandem organic solar cell using titanyl phthalocyanine, vanadyl phthalocyanine, poly(3-hexylthiophene) (P3HT) and [6, 6]-phenyl C{sub 61}-butyric acid methyl ester (PCBM) were improved. Effect of annealing and solvent treatment on surface morphologies of the active layer was investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed for improvement of the photovoltaic performance.

Fabrication and characterization of inverted organic solar cells using shuttle cock-type metal phthalocyanine and PCBM:P3HT

International Nuclear Information System (INIS)

Suzuki, Atsushi; Furukawa, Ryo; Akiyama, Tsuyoshi; Oku, Takeo

2015-01-01

Inverted organic solar cells using shuttle cock-type phthalocyanine, semiconducting polymer and fullerenes were fabricated and characterized. Photovoltaic and optical properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristics. The photovoltaic properties of the tandem organic solar cell using titanyl phthalocyanine, vanadyl phthalocyanine, poly(3-hexylthiophene) (P3HT) and [6, 6]-phenyl C 61 -butyric acid methyl ester (PCBM) were improved. Effect of annealing and solvent treatment on surface morphologies of the active layer was investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed for improvement of the photovoltaic performance

Electrochemistry and spectroelectrochemistry of tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine, Lu{sub 2}Pc{sub 4} and dimeric lutetium(III) phthalocyanine, Lu{sub 2}Pc{sub 2}(OAc){sub 2}

Energy Technology Data Exchange (ETDEWEB)

Koca, Atif [Chemical Engineering Department, Engineering Faculty, Marmara University, TR34722 Goeztepe, Istanbul (Turkey); Ceyhan, Tanju; Erbil, Mehmet K. [Department of Biochemistry, Division of Organic Chemistry, Guelhane Medical Academy (GATA), Ankara (Turkey); Ozkaya, Ali Riza [Department of Chemistry, Marmara University, TR34722 Goeztepe, Istanbul (Turkey)], E-mail: aliozkaya@marmara.edu.tr; Bekaroglu, Ozer [Department of Chemistry, Technical University of Istanbul, TR34469 Maslak, Istanbul (Turkey)], E-mail: obek@itu.edu.tr

2007-11-09

In this study, electrochemical, electrochromic and spectroelectrochemical properties of a tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine (Lu{sub 2}Pc{sub 4}2) were investigated explicitly as compared with a tert-butylcalix[4]arene bridged dimeric lutetium(III) phthalocyanine [Lu{sub 2}Pc{sub 2}(OAc){sub 2}1]. Distinctive differences between electrochemical and electrochromic properties of 1 and 2 were detected. Moreover, the properties of 1 and 2 were compared with previously reported S{sub 4}(CH{sub 2}){sub 4} bridged Lu{sub 2}Pc{sub 2}(OAc){sub 2} and Lu{sub 2}Pc{sub 4}. The calixarene bridged phthalocyanine (Pc) compounds, 1 and 2 showed well-defined electrochromic behaviour with green-blue and blue-purple colour transitions. The enhanced electrochromic properties of 2, as compared to 1, were attributed to its double-decker structure, probably allowing the formation of suitable ion channels for the counter ion movement in the solid film.

Zinc(II) phthalocyanines immobilized in mesoporous silica Al-MCM-41 and their applications in photocatalytic degradation of pesticides

Energy Technology Data Exchange (ETDEWEB)

Silva, M. [Departamento de Quimica, Universidade de Coimbra, Rua Larga, 3004-535 Coimbra (Portugal); Laboratoire de Photochimie Moleculaire et Macromoleculaire, UMR CNRS 6505, Universite Blaise Pascal, F-63177 Aubiere cedex (France); Calvete, M.J.F.; Goncalves, N.P.F.; Burrows, H.D. [Departamento de Quimica, Universidade de Coimbra, Rua Larga, 3004-535 Coimbra (Portugal); Sarakha, M. [Laboratoire de Photochimie Moleculaire et Macromoleculaire, UMR CNRS 6505, Universite Blaise Pascal, F-63177 Aubiere cedex (France); Fernandes, A.; Ribeiro, M.F. [Instituto para a Biotecnologia e Bioengenharia, Centro para a Engenharia Biologica e Quimica, Instituto Superior Tecnico - Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Azenha, M.E., E-mail: meazenha@ci.uc.pt [Departamento de Quimica, Universidade de Coimbra, Rua Larga, 3004-535 Coimbra (Portugal); Pereira, M.M., E-mail: mmpereira@qui.uc.pt [Departamento de Quimica, Universidade de Coimbra, Rua Larga, 3004-535 Coimbra (Portugal)

2012-09-30

Highlights: Black-Right-Pointing-Pointer Complete immobilization of zinc(II) phthalocyanines accomplished in Al-MCM-41. Black-Right-Pointing-Pointer Efficient photodegradation of model pesticides achieved using 365 nm irradiation. Black-Right-Pointing-Pointer Sodium azide experiments showed the involvement of singlet oxygen ({sup 1}O{sub 2}). - Abstract: In the present study the authors investigated a set of three new zinc(II) phthalocyanines (zinc(II) tetranitrophthalocyanine (ZnTNPc), zinc(II) tetra(phenyloxy)phthalocyanine (ZnTPhOPc) and the tetraiodide salt of zinc(II)tetra(N,N,N-trimethylaminoethyloxy) phthalocyaninate (ZnTTMAEOPcI)) immobilized into Al-MCM-41 prepared via ship-in-a-bottle methodology. The samples were fully characterized by diffuse reflectance-UV-vis spectroscopy (DRS-UV-vis), luminescence, thermogravimetric analysis (TG/DSC), N{sub 2} adsorption techniques and elemental analysis. A comparative study was made on the photocatalytic performance upon irradiation within the wavelength range 320-460 nm of these three systems in the degradation of pesticides fenamiphos and pentachlorophenol. ZnTNPc-Al-MCM-41 and ZnTTMAEOPcI-Al-MCM-41 were found to be the most active systems, with the best performance observed with the immobilized cationic phthalocyanine, ZnTTMAEOPcI-Al-MCM-41. This system showed high activity even after three photocatalytic cycles. LC-MS product characterization and mechanistic studies indicate that singlet oxygen ({sup 1}O{sub 2}), produced by excitation of these immobilized photosensitizers, is a key intermediate in the photocatalytic degradation of both pesticides.

Zinc(II) phthalocyanines immobilized in mesoporous silica Al-MCM-41 and their applications in photocatalytic degradation of pesticides

International Nuclear Information System (INIS)

Silva, M.; Calvete, M.J.F.; Gonçalves, N.P.F.; Burrows, H.D.; Sarakha, M.; Fernandes, A.; Ribeiro, M.F.; Azenha, M.E.; Pereira, M.M.

2012-01-01

Highlights: ► Complete immobilization of zinc(II) phthalocyanines accomplished in Al-MCM-41. ► Efficient photodegradation of model pesticides achieved using 365 nm irradiation. ► Sodium azide experiments showed the involvement of singlet oxygen ( 1 O 2 ). - Abstract: In the present study the authors investigated a set of three new zinc(II) phthalocyanines (zinc(II) tetranitrophthalocyanine (ZnTNPc), zinc(II) tetra(phenyloxy)phthalocyanine (ZnTPhOPc) and the tetraiodide salt of zinc(II)tetra(N,N,N-trimethylaminoethyloxy) phthalocyaninate (ZnTTMAEOPcI)) immobilized into Al-MCM-41 prepared via ship-in-a-bottle methodology. The samples were fully characterized by diffuse reflectance-UV–vis spectroscopy (DRS-UV–vis), luminescence, thermogravimetric analysis (TG/DSC), N 2 adsorption techniques and elemental analysis. A comparative study was made on the photocatalytic performance upon irradiation within the wavelength range 320–460 nm of these three systems in the degradation of pesticides fenamiphos and pentachlorophenol. ZnTNPc-Al-MCM-41 and ZnTTMAEOPcI-Al-MCM-41 were found to be the most active systems, with the best performance observed with the immobilized cationic phthalocyanine, ZnTTMAEOPcI-Al-MCM-41. This system showed high activity even after three photocatalytic cycles. LC–MS product characterization and mechanistic studies indicate that singlet oxygen ( 1 O 2 ), produced by excitation of these immobilized photosensitizers, is a key intermediate in the photocatalytic degradation of both pesticides.

Reactive oxygen species produced by irradiation of some phthalocyanine derivatives

Czech Academy of Sciences Publication Activity Database

Černý, J.; Karásková, M.; Rakušan, J.; Nešpůrek, Stanislav

2010-01-01

Roč. 210, č. 1 (2010), s. 82-88 ISSN 1010-6030 R&D Projects: GA AV ČR KAN400720701 Institutional research plan: CEZ:AV0Z40500505 Keywords : singlet oxygen * photosensitizer * phthalocyanine Subject RIV: CG - Electrochemistry Impact factor: 2.243, year: 2010

Synthesis and spectral properties of europium phthalocyanine complexes

International Nuclear Information System (INIS)

Maksimova, K.N.; Bazyakina, N.L.; Kutyreva, V.V.; Suvorova, O.N.; Domrachev, G.A.

2008-01-01

Synthesis of europium monophthalocyanic complexes with thenoyltrifluroacetonate (tta) and ferrocenoyltrifluoroacetate (fta) ligands has been considered. Spectral characteristics of complexes PcEu(tta)(ttaH) and PcEu(fta)(ftaH) (Pc - phthalocyanine ligand) have been investigated. One of β-diketonate ligand is proposed to bind with europium ion covalently, and the second ligand saturates coordination sphere of europium due to donor-acceptor binding [ru

Electronic and gas sensing properties of soluble phthalocyanines

Czech Academy of Sciences Publication Activity Database

Pochekaylov, Sergey; Rais, David; Nešpůrek, Stanislav; Rakušan, J.; Karásková, M.

2009-01-01

Roč. 27, č. 3 (2009), s. 781-795 ISSN 0137-1339. [International Conference on Electtrical and Related Properties of Organic Solids /11./. Wroclaw, 13.07.2008-17.07.2008] R&D Projects: GA AV ČR KAN400720701 Institutional research plan: CEZ:AV0Z40500505 Keywords : substituted phthalocyanine * nitrogen dioxide sensor * optical properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.384, year: 2009

Application of nanophotosensitizers (aluminum phthalocyanine nanoparticles) for early diagnosis and prevention of inflammatory diseases

Science.gov (United States)

Kuznetsova, J. O.; Makarov, V. I.

2016-08-01

This paper deals with a possibility of new types of photosensitizers application - Aluminum Phthalocyanine nanoparticles (nAlPc) in clinical practice for diagnosis, prevention and therapy of inflammatory diseases in dentistry and traumatology. It was detected that the aluminum phthalocyanine (AlPc) fluoresces in the nanoparticle form in the presence of pathologic microflora or inflammation process. It will make possible to detect the local accumulation of pathological microflora on the enamel surface and also for diagnostics and treatment of inflammatory diseases. Experimental studies of interaction of NP-AlPc with tooth enamel and with biological joint tissue at arthrosis are presented.

Application of nanophotosensitizers (aluminum phthalocyanine nanoparticles) for early diagnosis and prevention of inflammatory diseases

International Nuclear Information System (INIS)

Kuznetsova, J O; Makarov, V I

2016-01-01

This paper deals with a possibility of new types of photosensitizers application - Aluminum Phthalocyanine nanoparticles (nAlPc) in clinical practice for diagnosis, prevention and therapy of inflammatory diseases in dentistry and traumatology. It was detected that the aluminum phthalocyanine (AlPc) fluoresces in the nanoparticle form in the presence of pathologic microflora or inflammation process. It will make possible to detect the local accumulation of pathological microflora on the enamel surface and also for diagnostics and treatment of inflammatory diseases. Experimental studies of interaction of NP-AlPc with tooth enamel and with biological joint tissue at arthrosis are presented. (paper)

Properties of uncharged water-soluble tetra({omega}-methoxypolyethyleneoxy)phthalocyanine free base: Viable switching of the optical response by means of H{sub 3}O{sup +} ions

Energy Technology Data Exchange (ETDEWEB)

Mineo, Placido [Department of Chemistry, University of Catania and INSTM UdR of Catania, Viale Andrea Doria 6, 95125 Catania (Italy); Istituto per i Processi Chimico Fisici - CNR, Viale Ferdinando Stagno D' Alcontres, 37, 98158 Messina (Italy); Lupo, Fabio; Fragala, Ignazio; Scamporrino, Emilio [Department of Chemistry, University of Catania and INSTM UdR of Catania, Viale Andrea Doria 6, 95125 Catania (Italy); Gulino, Antonino, E-mail: agulino@unict.it [Department of Chemistry, University of Catania and INSTM UdR of Catania, Viale Andrea Doria 6, 95125 Catania (Italy)

2012-02-15

An uncharged water-soluble tetra ({omega}-methoxypolyethyleneoxy)phthalocyanine was characterized by MALDI-TOF mass spectrometry, UV-vis and luminescence measurements. The polyether substituents render water soluble this uncharged phthalocyanine. Relevant changes are observed in emission measurements upon protonation. The phthalocyanine free base and its protonated forms can be switched alternating H{sub 3}O{sup +} and OH{sup -} ions as inputs, being the intensity of the luminescence spectra the output. Binary codes 1 or 0 can be assigned to the high luminescent phthalocyanine free base state or to the low luminescent protonated state, respectively. The read-out procedure is fast and the system is reversible. In addition, the exploiting of the luminescent properties of the present water soluble phthalocyanine could be of relevance also for biological applications (photosensitizers for the photodynamic therapy). Highlights: Black-Right-Pointing-Pointer An uncharged water soluble tetra ({omega}-methoxypolyethyleneoxy)phthalocyanine was characterized. Black-Right-Pointing-Pointer Phthalocyanine protonation changes the luminescence output. Black-Right-Pointing-Pointer The system can be switched alternating H{sub 3}O{sup +} and OH{sup -} as inputs. Black-Right-Pointing-Pointer The read-out procedure is fast and reversible. Black-Right-Pointing-Pointer Binary codes are assigned to the high and low luminescent states, respectively.

Iron phthalocyanine supported on amidoximated PAN fiber as effective catalyst for controllable hydrogen peroxide activation in oxidizing organic dyes

International Nuclear Information System (INIS)

Han, Zhenbang; Han, Xu; Zhao, Xiaoming; Yu, Jiantao; Xu, Hang

2016-01-01

Iron(II) phthalocyanine was immobilized onto amidoximated polyacrylonitrile fiber to construct a bioinspired catalytic system for oxidizing organic dyes by H 2 O 2 activation. The amidoxime groups greatly helped to anchor Iron(II) phthalocyanine molecules onto the fiber through coordination interaction, which has been confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and UV diffuse reflectance spectroscopy analyses. Electron spin resonance studies indicate that the catalytic process of physically anchored Iron(II) phthalocyanine performed via a hydroxyl radical pathway, while the catalyst bonded Iron(II) phthalocyanine through coordination effect could selectively catalyze the H 2 O 2 decomposition to generate high-valent iron-oxo species. This may result from the amidoxime groups functioning as the axial fifth ligands to favor the heterolytic cleavage of the peroxide O−O bond. This feature also enables the catalyst to only degrade the dyes adjacent to the catalytic active centers and enhances the efficient utilization of H 2 O 2 . In addition, this catalyst could effectively catalyze the mineralization of organic dyes and can be easily recycled without any loss of activity.

Determination of Trace Amounts of Gold in Environmental Samples by Adsorptive Stripping Voltammetry of Its Complex with Rhodamine Using Osc-Pls

Directory of Open Access Journals (Sweden)

A. Akrami

2012-11-01

Full Text Available The multivariate calibration method was applied for the determination of trace amounts of gold based on a hanging mercury drop electrode (HMDE in the presence of rhodanine, followed by reduction of adsorbed gold by voltammetric scan using differential pulse modulation The optimum experimental conditions are: rhodanine concentration of 0.20 mg mL-1, pH 5.0, accumulation potential of -600 mV versus Ag/AgCl, accumulation time of 100 sec, scan rate of 30 mV s-1 and pulse height of 100 mV. The calibration matrix for partial least squares (PLS regression was designed with 9 samples. Orthogonal signal correction (OSC is a preprocessing technique used for removing the information unrelated to the target variables based on constrained principal component analysis. OSC is a suitable preprocessing method for PLS calibration without loss of prediction capacity using electrochemical method. The RMSEP for gold determination with PLS and OSC-PLS were 8.51 and 1.94, respectively. This procedure allows the determination of gold in synthetic and real samples with good reliability of the determination. 

Enhanced Charge Separation Efficiency in Pyridine-Anchored Phthalocyanine-Sensitized Solar Cells by Linker Elongation.

Science.gov (United States)

Ikeuchi, Takuro; Agrawal, Saurabh; Ezoe, Masayuki; Mori, Shogo; Kimura, Mutsumi

2015-11-01

A series of zinc phthalocyanine sensitizers (PcS22-24) having a pyridine anchoring group are designed and synthesized to investigate the structural dependence on performance in dye-sensitized solar cells. The pyridine-anchor zinc phthalocyanine sensitizer PcS23 shows 79 % incident-photon to current-conversion efficiency (IPCE) and 6.1 % energy conversion efficiency, which are comparable with similar phthalocyanine dyes having a carboxylic acid anchoring group. Based on DFT calculations, the high IPCE is attributed with the mixture of an excited-state molecular orbital of the sensitizer and the orbitals of TiO2 . Between pyridine and carboxylic acid anchor dyes, opposite trends are observed in the linker-length dependence of the IPCE. The red-absorbing PcS23 is applied for co-sensitization with a carboxyl-anchor organic dye D131 that has a complementary spectral response. The site-selective adsorption of PcS23 and D131 on the TiO2 surface results in a panchromatic photocurrent response for the whole visible-light region of sun light. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Side chain polysiloxanes with phthalocyanine moieties

Directory of Open Access Journals (Sweden)

T. Ganicz

2012-05-01

Full Text Available Side chain polysiloxane with 5-(pentyloxy-3-methyloxy-9,10,16,17,23,24-hexakis(octenyloxyphthalocyanine moieties is synthesized by hydrosilylation reaction. The phase behavior and thermooptical properties of the polysiloxane and starting 2-(pent-4-enyloxy-3-methyloxy-9,10,16,17,23,24-hexakis(octenyloxyphthalocyanine is examined by POM (Polarizing optical microscopy, TOA (thermooptical analysis, DSC (differential scanning calorimetry, AFM (atomic force microscopy and SAXS (small angle X-ray scattering studies. The effect of the attachment of phthalocyanine to polysiloxane chains over phase transitions and phase morphology is discussed in details.

Effect of iodine doping of phthalocyanine on the photocurrent generation in a phthalocyanine/C{sub 60} heterojunction

Energy Technology Data Exchange (ETDEWEB)

Mizuta, Shinsei; Iyota, Masatoshi; Tanaka, Senku; Hiromitsu, Ichiro, E-mail: hiromitu@riko.shimane-u.ac.jp

2012-06-30

Photocurrent generation in an indium-tin oxide (ITO)/iodine-doped Ni-phthalocyanine (NiPc-I{sub x})/C{sub 60}/In/Al heterojunction device with x {approx} 1 was studied. By keeping the device in air after preparation, the device slowly reached a stationary state in which the sign of the photocurrent is opposite to that of a non-doped ITO/NiPc/C{sub 60}/In/Al device although the rectification direction for the dark current is the same. By a simulation of incident photon-to-current conversion efficiency spectra and a measurement of internal electric field by electroabsorption spectroscopy, it was elucidated that, in the doped device, the band bending near the phthalocyanine/C{sub 60} interface is absent and the photocurrent is generated by a weak Schottky barrier at the C{sub 60}/In interface. It is also shown that the C{sub 60} film encapsulates the doped iodine into the NiPc-I{sub x} layer to stabilize the doping level and prevent the reaction of iodine with In. - Highlights: Black-Right-Pointing-Pointer The C{sub 60} film deposited on a NiPc-I{sub x} film encapsulates the doped iodine. Black-Right-Pointing-Pointer An iodine-doped device generates a photocurrent of inverted direction. Black-Right-Pointing-Pointer The internal electric field is also inverted. Black-Right-Pointing-Pointer The activity of photocurrent generation at the heterojunction is quenched. Black-Right-Pointing-Pointer Photocurrent is generated at the C{sub 60}/In interface.

An innovative OSCE clinical log station: a quantitative study of its influence on Log use by medical students

Directory of Open Access Journals (Sweden)

Hudson Judith N

2012-11-01

Full Text Available Abstract Background A Clinical Log was introduced as part of a medical student learning portfolio, aiming to develop a habit of critical reflection while learning was taking place, and provide feedback to students and the institution on learning progress. It was designed as a longitudinal self-directed structured record of student learning events, with reflection on these for personal and professional development, and actions planned or taken for learning. As incentive was needed to encourage student engagement, an innovative Clinical Log station was introduced in the OSCE, an assessment format with established acceptance at the School. This study questions: How does an OSCE Clinical Log station influence Log use by students? Methods The Log station was introduced into the formative, and subsequent summative, OSCEs with careful attention to student and assessor training, marking rubrics and the standard setting procedure. The scoring process sought evidence of educational use of the log, and an ability to present and reflect on key learning issues in a concise and coherent manner. Results Analysis of the first cohort’s Log use over the four-year course (quantified as number of patient visits entered by all students revealed limited initial use. Usage was stimulated after introduction of the Log station early in third year, with some improvement during the subsequent year-long integrated community-based clerkship. Student reflection, quantified by the mean number of characters in the ‘reflection’ fields per entry, peaked just prior to the final OSCE (mid-Year 4. Following this, very few students continued to enter and reflect on clinical experience using the Log. Conclusion While the current study suggested that we can’t assume students will self-reflect unless such an activity is included in an assessment, ongoing work has focused on building learner and faculty confidence in the value of self-reflection as part of being a competent

The complex nature of phthalocyanine/gold interfaces

International Nuclear Information System (INIS)

Lindner, Susi; Treske, Uwe; Knupfer, Martin

2013-01-01

We compare the electronic properties of the interface between Au(1 0 0) and cobalt phthalocyanine (CoPc), fluorinated F 16 CoPc as well as CuPc using X-ray photoemission spectroscopy and valence band ultra-violet photoemission spectroscopy. Our results show that in addition to the formation of an interface dipole at the interfaces of CoPc and F 16 CoPc to gold, there is a local charge transfer to the central Co ion, which as a result is reduced to Co(I).

Laser deposition of sulfonated phthalocyanines for gas sensors

Czech Academy of Sciences Publication Activity Database

Fitl, Přemysl; Vrňata, M.; Kopecký, D.; Vlček, J.; Škodová, J.; Bulíř, Jiří; Novotný, Michal; Pokorný, Petr

2014-01-01

Roč. 302, MAY (2014), s. 37-41 ISSN 0169-4332. [European-Materials-Research-Society Symposium on Laser Material Interactions for Micro- and Nano- Applications /5./. Strasbourg, 27.05.2013-31.05.2013] R&D Projects: GA ČR(CZ) GAP108/11/1298 Institutional support: RVO:68378271 Keywords : Matrix Assisted Pulsed Laser Evaporation * substituted phthalocyanine s * gas sensors * impedance measurements Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.711, year: 2014

Synthesis of phthalocyanines-ALA conjugates: water-soluble compounds with low aggregation.

Science.gov (United States)

de Oliveira, Kleber T; de Assis, Francisco F; Ribeiro, Anderson O; Neri, Claudio R; Fernandes, Adjaci U; Baptista, Mauricio S; Lopes, Norberto P; Serra, Osvaldo A; Iamamoto, Yassuko

2009-10-16

Syntheses of two water-soluble phthalocyanines (Pc) containing 5-aminolevulinic acid (ALA) linked to the core structure are described. These compounds were prepared by using original functionalizations, and they present remarkable structural and photophysical features, indicating that they could be applied to photodynamic therapy (PDT).

Degradation of natural toxins by phthalocyanines-example of cyanobacterial toxin, microcystin

Czech Academy of Sciences Publication Activity Database

Jančula, D.; Blahová, L.; Karásková, M.; Maršálek, Blahoslav

2010-01-01

Roč. 62, č. 2 (2010), s. 273-278 ISSN 0273-1223 R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516 Keywords : microcystin * phthalocyanine * singled oxygen Subject RIV: EF - Botanics Impact factor: 1.056, year: 2010

Iron phthalocyanine supported on amidoximated PAN fiber as effective catalyst for controllable hydrogen peroxide activation in oxidizing organic dyes

Energy Technology Data Exchange (ETDEWEB)

Han, Zhenbang, E-mail: hzbang@aliyun.com [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China); Key Laboratory of Advanced Textile Composite Materials, Ministry of Education of China, Tianjin 300387 (China); Han, Xu [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China); Zhao, Xiaoming, E-mail: zhaoxiaoming@tjpu.edu.cn [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China); Key Laboratory of Advanced Textile Composite Materials, Ministry of Education of China, Tianjin 300387 (China); Yu, Jiantao; Xu, Hang [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China)

2016-12-15

Iron(II) phthalocyanine was immobilized onto amidoximated polyacrylonitrile fiber to construct a bioinspired catalytic system for oxidizing organic dyes by H{sub 2}O{sub 2} activation. The amidoxime groups greatly helped to anchor Iron(II) phthalocyanine molecules onto the fiber through coordination interaction, which has been confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and UV diffuse reflectance spectroscopy analyses. Electron spin resonance studies indicate that the catalytic process of physically anchored Iron(II) phthalocyanine performed via a hydroxyl radical pathway, while the catalyst bonded Iron(II) phthalocyanine through coordination effect could selectively catalyze the H{sub 2}O{sub 2} decomposition to generate high-valent iron-oxo species. This may result from the amidoxime groups functioning as the axial fifth ligands to favor the heterolytic cleavage of the peroxide O−O bond. This feature also enables the catalyst to only degrade the dyes adjacent to the catalytic active centers and enhances the efficient utilization of H{sub 2}O{sub 2}. In addition, this catalyst could effectively catalyze the mineralization of organic dyes and can be easily recycled without any loss of activity.

Ambipolar carrier transport properties and molecular packing structure of octahexyl-substituted copper phthalocyanine

Science.gov (United States)

Watanabe, Ken; Watanabe, Koichi; Tohnai, Norimitsu; Itani, Hiromichi; Shimizu, Yo; Fujii, Akihiko; Ozaki, Masanori

2018-04-01

The charge carrier mobility of a solution-processable low-molecular-weight organic semiconductor material, i.e., 1,4,8,11,15,18,22,25-octahexylphthalocyanine copper complex (C6PcCu), was investigated by the time-of-flight technique. The anomalous ambipolar carrier mobility was discussed from the viewpoint of the molecular packing structure, which was clarified by single-crystal X-ray structure analysis. In the comparison between the molecular packing structures of C6PcCu and its metal-free-type homologue, it was found that the difference in carrier mobility originates from the rotation of the molecule, which is caused by the steric hindrance due to the introduction of a center metal and the interpenetration of the nonperipheral alkyl chains.

Is the OSCE more stressful? Examination anxiety and its consequences in different assessment methods in dental education

NARCIS (Netherlands)

Brand, H.S.; Schoonheim-Klein, M.

2009-01-01

Objective: To measure the levels of anxiety, self-perception of preparation and expectation for success induced by an objective structured clinical examination (OSCE), a written examination and a preclinical preparation test, and to examine the effects of the three predictive variables on the

Environmentally Friendly Phthalocyanine Catalysts for Water Decontamination - Non Photocatalytic Systems

Czech Academy of Sciences Publication Activity Database

Klusoň, Petr; Drobek, M.; Zsigmond, A.; Baranyi, J.; Bata, P.; Zárubová, Š.; Kalaji, A.

2009-01-01

Roč. 91, 3-4 (2009), s. 605-609 ISSN 0926-3373 R&D Projects: GA ČR GD203/03/H140; GA AV ČR KAN400720701 Institutional research plan: CEZ:AV0Z40720504 Keywords : phthalocyanines * phenol * chlorophenols Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 5.252, year: 2009

Covalent Functionalization of Carbon Nanotube by Tetrasubtituted Amino Manganese Phthalocyanine

Institute of Scientific and Technical Information of China (English)

Zheng Long YANG; Hong Zheng CHEN; Lei CAO; Han Yin LI; Mang WANG

2004-01-01

The multiwall carbon nanotube (MWCNT) bonded to 2, 9, 16, 23-tetraamino manganese phthalocyanine (TAMnPc) was obtained by covalent functionalization, and its chemical structure was characterized by TEM. The photoconductivity of single-layered photoreceptors, where MWCNT bonded by TAMnPc (MWCNT-b-TAMnPc) served as the charge generation material (CGM), was also studied.

Phthalocyanine as Sensitive Coatings for QCM Sensors-Experimental and Computational Approaches

International Nuclear Information System (INIS)

Erbahar, D. D.; Harbeck, M.; Guerol, I.; Musluoglu, E.; Oeztuerk, Z. Z.; Berber, S.

2011-01-01

Sorption of organic compounds from aqueous phase into phthalocyanines (Pc) is studied using QCM sensors and Density Functional Theory (DFT) for the first time. The focus is set on the influence of substitution type and central metal atom on the liquid sensing properties of the Pcs.

Optical spectra of phthalocyanines and related compounds a guide for beginners

CERN Document Server

Isago, Hiroaki

2015-01-01

This book displays how optical (absorption, emission, and magnetic circular dichroism) spectra of phthalocyanines and related macrocyclic dyes can be varied from their prototypical ones depending on conditions. As these compounds can be involved in colorful chemistry (which might be driven by impurities in solvents), their spectra behave like the sea-god Proteus in their mutability. Therefore, those who have been engaged with phthalocyanines for the first time, including even educated professional researchers and engineers, may have been embarrassed by the deceptive behavior of their compounds and could have, in the worst cases, given up their projects. This book is aimed not merely at reviewing the optical spectra, but also at helping such people, particularly beginners, to figure them out by showing some examples of their prototypical spectra and their variations in several situations. For the purpose of better understanding, the book also provides an introduction to their theoretical backgrounds as graphic...

Type II photoinitiator substituted zinc phthalocyanine: Synthesis, photophysical and photopolymerization studies

Energy Technology Data Exchange (ETDEWEB)

Korkut, Sibel Eken [Department of Chemistry, Yıldız Technical University, 34210 Davutpaşa, İstanbul (Turkey); Temel, Gokhan [Department of Polymer Engineering, Yalova University, 77100 Yalova (Turkey); Balta, Demet Karaca [Department of Chemistry, Yıldız Technical University, 34210 Davutpaşa, İstanbul (Turkey); Arsu, Nergis, E-mail: narsu@yildiz.edu.tr [Department of Chemistry, Yıldız Technical University, 34210 Davutpaşa, İstanbul (Turkey); Şener, M. Kasım, E-mail: mkasimsener@gmail.com [Department of Chemistry, Yıldız Technical University, 34210 Davutpaşa, İstanbul (Turkey)

2013-04-15

The novel 4-(9-oxo-9 H-thioxanthen-2yloxy) phthalonitrile (TX-Pht) and its peripherally tetra substituted zinc phthalocyanine complex (TX-ZnPc) have been prepared and characterized by spectroscopic and elemental analysis techniques. Photoinitiated polymerization of methyl methacrylate (MMA) with TX-ZnPc has been investigated in the presence and absence of a co-initiator. Fluorescence and phosphorescence measurements have been also performed to determine the photophysical properties. Low fluorescence quantum yield (Φ{sub F}=0.08) compared to the unsubstituted ZnPc has been found. This allows initiator to undergo intersystem crossing into the triplet state and the lowest triplet state possesses π-π{sup ⁎} configuration. Highlights: ► Zinc phthalocyanine (ZnPc), peripherally functionalized with photoactive thioxanthone (TX) groups was synthesized. ► The photophysical and photochemical properties of resulting photoinitiator were studied in DMF. ► Photoinitiated polymerization of MMA with TX-ZnPc was investigated in the presence and absence of co-initiator.

Spectroscopic insights on selfassembly and excited state interactions between rhodamine and phthalocyanine molecules.

Science.gov (United States)

Geng, Hao; Zhang, Xian-Fu

2015-03-15

The absorption and fluorescence spectra as well as fluorescence lifetimes of tetrasulfonated zinc phthalocyanine ZnPc(SO3Na)4 were measured in the absence and presence of four rhodamine dyes, Rhodamine B (RB), Ethyl rhodamine B (ERB), Rhodamine 6G (R6G), Rhodamine 110 (R110), and Pyronine B (PYB). The ground state complexes of phthalocyanine-(Rhodamine)2 were observed which exhibit new absorption bands. The binding constants are all very large (0.86×10(5)-0.22×10(8) M(-1)), suggesting rhodamine-phthalocyanine pairs are very good combinations for efficient selfassembly. Both the fluorescence intensity and the lifetime values of ZnPc(SO3Na)4 were decreased by the presence of rhodamines. The structural effect of rhodamines on selfassembly is significant. The ground state binding and dynamic quenching capability is PYB>R6G>ERB>RB>R110. The dynamic fluorescence quenching is due to the photoinduced electron transfer (PET). The PET rate constant is very large and in the order of 10(13) M(-1) s(-1), much greater than kf and kic (in the order of 10(8) M(-1) s(-1)), which means that the PET efficiency is almost 100%. Therefore the non-covalent Pc-rhodamine is a very good pair of donor/acceptor for potential efficient solar energy conversion. Copyright © 2014 Elsevier B.V. All rights reserved.

Testing clinical competencies in undergraduate nursing education using Objective Structured Clinical Examination (OSCE) – a literature review of international practice

Science.gov (United States)

Beyer, Angelika; Dreier, Adina; Kirschner, Stefanie; Hoffmann, Wolfgang

2016-07-01

Background: In response to demographic trends in Germany nursing competencies are currently reevaluated. Since these have to be taught and trained in nursing education programs, efficient verification of the success is necessary. OSCEs are internationally well-recognized as a comprehensive tool for that. Aim: In this analysis we identified competencies worldwide, which are tested by OSCEs in undergraduate nursing education programs. Method: An international literature research was conducted. The selection criterion for an article was the specification of at least one verifiable competency. Afterwards the competencies were categorized into knowledge, skills and attitudes according to the German “Fachqualifikationsrahmen Pflege für die hochschulische Bildung”. Results: A total of 36 publications fulfilled all inclusion criteria. Relevant studies were predominantly initiated in the UK, Canada and Australia. Within all categories a total of n = 166 different competencies are mentioned. OSCEs are developed and performed in a broad range of methods. Most frequently skills were verified. The most common topic was sure handling of medication. Other important themes were communicative competencies in relation to patients and the ability of self-evaluation. Discussion/Conclusions: A variation in examination methods is appropriate as different competencies are acquired in preparation of the test. Evaluation took place on an individual or institutional level. Further research is needed.

Feedback promotes learning success! Which kind of feedback for the faculty is given by an interdisciplinary OSCE with focus on decision-making?

Directory of Open Access Journals (Sweden)

Stibane, Tina

2016-08-01

Full Text Available Clinical skills such as history taking, diagnostic reasoning, therapy planning, and giving advice are even more complex than practical skills like lung auscultation and have to be applied in complex clinical situations. We judged this competence in an interdisciplinary formative OSCE conducted with students of Marburg University. Results of 218 students passing 643 OSCE stations composed of 37 different scenarios were analyzed. As a competence based examination that reflects the practical skills gained during clinical training, the here presented analysis serves also as a feedback instrument for clinical teachers, their respective disciplines and the medical faculty as a whole.

Electrocatalytic behavior of carbon paste electrode modified with metal phthalocyanines nanoparticles toward the hydrogen evolution

International Nuclear Information System (INIS)

Abbaspour, Abdolkarim; Norouz-sarvestani, Fatemeh; Mirahmadi, Ehsan

2012-01-01

Highlights: ► The new construction of a carbon paste electrode impregnated with nanoparticles of Zn and Ni phthalocyanine (nano ZnPc and nano NiPc). ► The decrease overpotential and higher current value obtained in nano ZnPc and nano NiPc compared to bulky ZnPc and bulky NiPc, respectively. ► Types of the catalyst and pH of the solution affect the electro catalytic proton reduction reaction considerably. - Abstract: This paper describes the construction of a carbon paste electrode (CPE) impregnated with nanoparticles of Zn and Ni phthalocyanine (nano ZnPc and nano NiPc). These new electrodes (nano ZnPc-CPE and nano NiPc-CPE) reveal interesting electrocatalytic behavior toward hydrogen evolution reaction (HER). Voltammetric characteristics indicated that the proposed electrodes display better electrocatalytic activity compared to their corresponding bulky modified metal phthalocyanines (MPcs) in minimizing overpotential and increasing the reduction current of HER. Electrocatalytic activities irregularly change with the pH of the solution. However by increasing the pH while nano MPcs are still active, bulky MPcs are almost inactive, and their corresponding ΔE increase by increasing the pH.

Improved syntheses of high hole mobility phthalocyanines: A case of steric assistance in the cyclo-oligomerisation of phthalonitriles

Directory of Open Access Journals (Sweden)

Daniel J. Tate

2012-01-01

Full Text Available It has been shown that the base-initiated cyclo-oligomerisation of phthalonitriles is favoured by bulky α-substituents making it possible to obtain the metal-free phthalocyanine directly and in high yield. The phthalocyanine with eight α-isoheptyl substituents gives a high time-of-flight hole mobility of 0.14 cm2·V−1·s−1 within the temperature range of the columnar hexagonal phase, that is 169–189 °C.

Metal-phthalocyanine functionalized carbon nanotubes as catalyst for the oxygen reduction reaction: A theoretical study

Science.gov (United States)

Orellana, Walter

2012-07-01

The covalent functionalization of metallic single-walled carbon nanotubes (CNTs) with transition metal phthalocyanines (MPc, with M = Mn, Fe and Co) are addressed by density functional calculations. The CNT-MPc catalytic activity toward the oxygen reduction reaction (ORR) is investigated through the O2 stretching frequency adsorbed on the phthalocyanine metal center. We find better reduction abilities when the CNT functionalization occurs through sp2-like bonds. Multiple stable-spin states for the M-O2 adduct are also found for M = Mn and Fe, suggesting higher ORR rates. The CNT-MPc complexes show metallic characteristics, suggesting favorable conditions to work as ORR cathode catalysts in fuel cells.

Antimicrobial photodisinfection with Zn(II) phthalocyanine adsorbed on TiO2 upon UVA and red irradiation

Science.gov (United States)

Mantareva, Vanya; Eneva, Ivelina; Kussovski, Vesselin; Borisova, Ekaterina; Angelov, Ivan

2015-01-01

The light exposure on a daily basis has been well accepted as a competitive method for decontamination of wastewater. The catalytic properties of TiO2 offer a great potential to reduce the transmission of pathogens in the environment. Although the titanium dioxide shows high activity against pathogens, its general usage in water cleaning is limited due to the insufficient excitation natural light (about 3% of the solar spectrum). A hydrophobic dodecylpyridyloxy Zn(II)-phthalocyanine with four peripheral hydrocarbon chains of C12 (ZnPcDo) was immobilized on a photocatalyst TiO2 anatase (P25). The resulted greenish colored nanoparticles of phthalocyanine were characterized by the means of absorption, fluorescence and infrared spectroscopy. The laser scanning confocal fluorescence microscopy was used to visualize the phthalocyanine dye by the red fluorescence emission (650 - 740 nm). The intensive Q-band in the far red visible spectral region (~ 690 nm) suggested a monomeric state of phthalocyanine on TiO2 nanoparticles. Two pathogenic bacterial strains (methicillin-resistant Staphylococcus aureus - MRSA and Salmonella enteritidis) associated with wastewater were photoinactivated with the suspension of the particles. The effective photoinactivation was observed with 1 g.L-1 TiO2 anatase at irradiation with UVA 364 nm as with UVA 364 nm and LED 643 nm. The gram-negative Salmonella enteritidis was fully photoinactivated with ZnPcDo-TiO2 and TiO2 alone at UVA 346 nm and at irradiation with two light sources (364 nm + 643 nm). The proposed conjugate appears as an useful composite material for antibacterial disinfection.

Phthalocyanine identification in paintings by reflectance spectroscopy. A laboratory and in situ study

Science.gov (United States)

Poldi, G.; Caglio, S.

2013-06-01

The importance of identifying pigments using non invasive (n.i.) analyses has gained increasing importance in the field of spectroscopy applied to art conservation and art studies. Among the large set of pigments synthesized and marketed during 20th century, surely phthalocyanine blue and green pigments occupy an important role in the field of painting (including restoration) and printing, thanks to their characteristics like brightness and fastness. This research focused on the most used phthalocyanine blue (PB15:1 and PB15:3) and green pigments (PG7), and on the possibility to identify these organic compounds using a methodology like reflectance spectroscopy in the UV, visible and near IR range (UV-vis-NIR RS), performed easily through portable instruments. Laboratory tests and three examples carried out on real paintings are discussed.

Exploration of Nursing Faculty Members' Lived Experiences of Objective Structured Clinical Examination (OSCE) in Undergraduate Nursing Education

Science.gov (United States)

Obizoba, Cordelia O.

2014-01-01

The purpose of this phenomenological study was to gain an understanding of nursing faculty members' lived experiences of Objective Structured Clinical Examination (OSCE) in undergraduate nursing education. As owners of their programs' curriculum, nursing faculties are charged with the responsibility of providing needed knowledge, skills, and…

Using modified information delivery to enhance the traditional pharmacy OSCE program at TMU - a pilot study.

Science.gov (United States)

Lin, Che-Wei; Chang, Elizabeth H; Clinciu, Daniel L; Peng, Yun-Ting; Huang, Wen-Chen; Wu, Chien-Chih; Wu, Jen-Chieh; Li, Yu-Chuan

2018-05-01

Objective Structured Clinical Examination (OSCE) has been used in many areas of healthcare training over the years. However, it constantly needs to be upgraded and enhanced due to technological and teaching changes. We aim at implementing an integrative OSCE method which employs informatics via the virtual patient within the pharmacy education curriculum at Taipei Medical University to enhance the pharmacy students' competence for using and disseminating information and to also improve critical thinking and clinical reasoning. We propose an integrated pharmacy OSCE which uses standardized patients and virtual patients (DxR Clinician). To evaluate this method, we designed four simulated stations and pilot tested with 19 students in the first year of the Master in Clinical Pharmacy program. Three stations were simulated as the inpatient pharmacy: 1) History and lab data collection; 2) Prescription review; 3) Calling physician to discuss potential prescription problems. The fourth was simulated as the patient ward station to provide patient education. A satisfaction questionnaire was administered at the end of the study. Students rated their ability of 2.84, 2.37, 2.37, and 3.63 of 5 for each of the four stations, with the second and third being the most difficult stations. The method obtained an average rating of 4.32 of 5 for relevance, 4.16 for improving clinical ability, 4.32 for practicality in future healthcare work, and 4.28 for willing to have another similar learning experience. The integration of Virtual Patient in this study reveals that this assessment method is efficient and practical in many aspects. Most importantly, it provides the test taker with a much closer real-life clinical encounter. Although it is in many ways more difficult, it also provides for better "learning from mistakes" opportunities for test-takers. Copyright © 2017. Published by Elsevier B.V.

The use of global rating scales for OSCEs in veterinary medicine.

Directory of Open Access Journals (Sweden)

Emma K Read

Full Text Available OSCEs (Objective Structured Clinical Examinations are widely used in health professions to assess clinical skills competence. Raters use standardized binary checklists (CL or multi-dimensional global rating scales (GRS to score candidates performing specific tasks. This study assessed the reliability of CL and GRS scores in the assessment of veterinary students, and is the first study to demonstrate the reliability of GRS within veterinary medical education. Twelve raters from two different schools (6 from University of Calgary [UCVM] and 6 from Royal (Dick School of Veterinary Studies [R(DSVS] were asked to score 12 students (6 from each school. All raters assessed all students (video recordings during 4 OSCE stations (bovine haltering, gowning and gloving, equine bandaging and skin suturing. Raters scored students using a CL, followed by the GRS. Novice raters (6 R(DSVS were assessed independently of expert raters (6 UCVM. Generalizability theory (G theory, analysis of variance (ANOVA and t-tests were used to determine the reliability of rater scores, assess any between school differences (by student, by rater, and determine if there were differences between CL and GRS scores. There was no significant difference in rater performance with use of the CL or the GRS. Scores from the CL were significantly higher than scores from the GRS. The reliability of checklist scores were .42 and .76 for novice and expert raters respectively. The reliability of the global rating scale scores were .7 and .86 for novice and expert raters respectively. A decision study (D-study showed that once trained using CL, GRS could be utilized to reliably score clinical skills in veterinary medicine with both novice and experienced raters.

Patterns of nucleotide diversity and phenotypes of two domestication related genes (OsC1 and Wx) in indigenous rice varieties in Northeast India.

Science.gov (United States)

Choudhury, Baharul Islam; Khan, Mohammed Latif; Dayanandan, Selvadurai

2014-06-16

During the domestication of crops, individual plants with traits desirable for human needs have been selected from their wild progenitors. Consequently, genetic and nucleotide diversity of genes associated with these selected traits in crop plants are expected to be lower than their wild progenitors. In the present study, we surveyed the pattern of nucleotide diversity of two selected trait specific genes, Wx and OsC1, which regulate amylose content and apiculus coloration respectively in cultivated rice varieties. The analyzed samples were collected from a wide geographic area in Northeast (NE) India, and included contrasting phenotypes considered to be associated with selected genes, namely glutinous and nonglutinous grains and colored and colorless apiculus. No statistically significant selection signatures were detected in both Wx and OsC1gene sequences. However, low level of selection that varied across the length of each gene was evident. The glutinous type varieties showed higher levels of nucleotide diversity at the Wx locus (πtot = 0.0053) than nonglutinous type varieties (πtot = 0.0043). The OsC1 gene revealed low levels of selection among the colorless apiculus varieties with lower nucleotide diversity (πtot = 0.0010) than in the colored apiculus varieties (πtot = 0.0023). The results revealed that functional mutations at Wx and OsC1genes considered to be associated with specific phenotypes do not necessarily correspond to the phenotypes in indigenous rice varieties in NE India. This suggests that other than previously reported genomic regions may also be involved in determination of these phenotypes.

Preparation and Characterization of Cu and Ni on Alumina Supports and Their Use in the Synthesis of Low-Temperature Metal-Phthalocyanine Using a Parallel-Plate Reactor

Directory of Open Access Journals (Sweden)

Carlos J. Lucio-Ortiz

2013-09-01

Full Text Available Ni- and Cu/alumina powders were prepared and characterized by X-ray diffraction (XRD, scanning electronic microscope (SEM, and N2 physisorption isotherms were also determined. The Ni/Al2O3 sample reveled agglomerated (1 μm of nanoparticles of Ni (30–80 nm however, NiO particles were also identified, probably for the low temperature during the H2 reduction treatment (350 °C, the Cu/Al2O3 sample presented agglomerates (1–1.5 μm of nanoparticles (70–150 nm, but only of pure copper. Both surface morphologies were different, but resulted in mesoporous material, with a higher specificity for the Ni sample. The surfaces were used in a new proposal for producing copper and nickel phthalocyanines using a parallel-plate reactor. Phthalonitrile was used and metallic particles were deposited on alumina in ethanol solution with CH3ONa at low temperatures; ≤60 °C. The mass-transfer was evaluated in reaction testing with a recent three-resistance model. The kinetics were studied with a Langmuir-Hinshelwood model. The activation energy and Thiele modulus revealed a slow surface reaction. The nickel sample was the most active, influenced by the NiO morphology and phthalonitrile adsorption.

Vibrational spectra of charge transfer complexes of lead phthalocyanine

International Nuclear Information System (INIS)

Oza, A.T.; Patel, S.G.; Patel, R.G.; Prajapati, S.M.; Vaidya, Rajiv

2005-01-01

Infrared spectra of six charge transfer complexes of lead phthalocyanine (PbPc), namely, PbPc-I 2 , PbPc-TCNQ, PbPc-DDQ, PbPc-chloranil, PbPc-TCNE and PbPc-TNF, where TCNQ=7,7,8,8-tetracyano-1,4-quinodimethane, DDQ=2,3-dichloro-5,6-dicyano-p-benzoquinone, TCNE=tetracyano-p-ethylene and TNF=2,4,5,7-tetranitro-9-fluorenone have been studied in the range of 400-4000 cm -1 . The analysis of featureless absorption is carried out for studying transition across the Peierls gap of 0.225 eV. The electronic absorption envelopes at 1500, 1100 and 3400 cm -1 are found to have Gaussian shapes and not the degenerate oscillators, as found in purely organic conductors. There is a pairing of two electrons on phthalocyanine ligand as required in Little's model, and consequently, the electronic absorption envelope is a doublet. Electronic absorption envelope is a doublet showing two peaks at 1500 and 1100 cm -1 , indicating a two-electron problem in PbPc. Metal-ligand vibrations between 400 and 700 cm -1 lead to indirect transition between the valence and conduction bands and phonon-mediated coupling between metal chains and the side chains

Optical-limiting response of rare-earth metallo-phthalocyanine-doped copolymer matrix

NARCIS (Netherlands)

Aneeshkumar, B.N.; Gopinath, P.; Vallabhan, C.P.G.; Nampoori, V.P.N.; Radhakrishnan, P.; Thomas, J.

2003-01-01

The nanosecond optical-limiting characteristics (at 532 nm) of some rare-earth metallo-phthalocyanines (Sm(Pc)2, Eu(Pc)2, and LaPc) doped in a copolymer matrix of poly(Me methacrylate) and Me-2-cyanoacrylate were studied for the 1st time to the authors' knowledge. The optical-limiting response is

Annealing assisted structural and surface morphological changes in Langmuir–Blodgett films of nickel octabutoxy phthalocyanine

Energy Technology Data Exchange (ETDEWEB)

Shilpa Harish, T.; Viswanath, P., E-mail: viswanath@cnsms.res.in

2016-01-01

We report our studies on thin films of metallo-phthalocyanine (MPc), Nickel(II)1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (NiPc(OBu){sub 8}) transferred in a well defined thermodynamic state over a self assembled monolayer (octadecyl trichlorosilane)/SiO{sub 2}/Si substrate using the Langmuir–Blodgett (LB) method. The films are characterized using differential scanning calorimetry (DSC), grazing incidence X-ray diffraction (GIXD) and atomic force microscopy (AFM) techniques. DSC studies on powdered samples in the bulk indicate enantiotropic solid–solid phase transition. GIXD studies on the as-deposited LB film show a Bragg peak indicating crystallinity of the thin film. Annealing (373 K) results in reduction of lattice spacing (1.21 Å) signifying changes in molecular packing within the unit cell. At this stage, an additional Bragg peak is observed which grows at the expense of the former one and they coexist between 373 K and 423 K. A discontinuity in lattice spacing from 20.73 to 15.12 Å with annealing indicates clearly a structural change of the underlying crystalline lattice. Correspondingly, the surface morphology images obtained using AFM show, with annealing, a transformation from spherical granular morphology to elongated, flat crystallites suggesting asymmetric growth process. Statistical parameters of the grain extracted from the AFM images show that the size, fractal dimension and circularity are affected by annealing. Based on these studies, we infer the structural and surface morphological changes of the meta-stable phase (Form I) to the stable phase (Form II) in annealed LB films of phthalocyanine. - Highlights: • Langmuir–Blodgett (LB) films of phthalocyanine subjected to thermal annealing. • Structural transformation and coexistence of polymorphs in LB films • Surface morphology changes from nanoscale grains to elongated crystallites. • Reduction of fractal dimension and circularity index reveals asymmetric growth.

The effect of the triblock properties on the morphologies and photophysical properties of nanoparticle loaded with carboxylic dendrimer phthalocyanine

Science.gov (United States)

Lv, Huafei; Chen, Zhe; Yu, Xinxin; Pan, Sujuan; Zhang, Tiantian; Xie, Shusen; Yang, Hongqin; Peng, Yiru

2016-09-01

Photodynamic therapy (PDT) is an emerging alternative treatment for various cancers and age-related macular degeneration. Phthalocyanines (Pcs) and their substituted derivatives are under intensive investigation as the second generation photosensitizers. A big challenge for the application of Pcs is poor solubility and limited accumulation in the tumor tissues, which severely reduced its PDT efficacy. Nano-delivery systems such as polymeric micelles are promising tools for increasing the solubility and improving delivery efficiency of Pcs for PDT application. In this paper, nanoparticles of amphiphilic triblock copolymer poly(L-lysine)-b-poly (ethylene glycol)-b-poly(L-lysine) were developed to encapsulate 1-2 generation carboxylic poly (benzyl aryl ether) dendrimer. The morphologies and photophysical properties of polymeric nanoparticles loaded with 1-2 generation dendritic phthalocyanines (G1-ZnPc(COOH)8/m and G2-ZnPc(COOH)16/m) were studied by AFM, UV/Vis and fluorescent spectroscopic method. The morphologies of self-assembled PLL-PEG-PLL aggregates exhibited concentration dependence. Its morphologies changed from cocoon-like to spheral. The diameters of G1-ZnPc(COOH)8/m and G2-ZnPc(COOH)16/m were in the range of 33-147 nm, increasing with the increase of the concentration of PLL-PEG-PLL. The morphologies of G2-ZnPc(COOH)16/m also changed from cocoon-like to sphere with the increase of the concentration of PLL-PEG-PLL. It was found that, the no obviously Q change was observed between the free phthalocyanines and nanoparticles. The fluorescence intensity of polymer nanoparticles were higher enhanced compared with free dendritic phthalocyanines. The dendrimer phthalocyanine loaded with poly(L-lysine)-b-poly (ethylene glycol)-b-poly(L-lysine) presented suitable physical stability, improved photophysical properties suggesting it may be considered as a promising formulation for PDT.

Synergetic Enhancement of the Photocatalytic Activity of TiO2 with Visible Light by Sensitization Using a Novel Push-Pull Zinc Phthalocyanine

Directory of Open Access Journals (Sweden)

A. Luna-Flores

2017-01-01

Full Text Available A new one-pot synthesis of a novel A3B-type asymmetric zinc phthalocyanine (AZnPc was developed. The phthalocyanine complex was characterized unambiguously and used to prepare a TiO2 hybrid photocatalyst to enhance its photocatalytic activity in the visible range. Different compositions of the phthalocyanine dye were tested in order to find the optimum amount of sensitizer to get the highest activity during the photocatalytic tests. The hybrid photocatalyst was characterized by UV-Vis diffuse reflectance (DRS and Fourier transform infrared spectroscopy (FT-IR and its photocatalytic activity was compared with that of the individual components considering the effects of sensitization on their efficiency to degrade Rhodamine B as a model reaction. A synergic improvement of the photocatalytic activity for the hybrid system was explained in terms of an improved electron injection from the photo-activated phthalocyanine to the TiO2. Considering the structural features of the phthalocyanine sensitizer and their effect on aggregation, some mechanistic aspects of its binding to TiO2 are suggested to account for the photocatalytic activity enhancement. Finally, the inhibitory effect on the sprouting of chia seeds (Salvia hispanica was evaluated in order to test the toxicity of the water effluent obtained after the photodegradation process. According to our growth inhibition assays, it was found that the Rh-B degradation by-products do not lead to an acute toxicity.

Understanding the application of OSC policy 9.1 during a takeover transaction

International Nuclear Information System (INIS)

Hayduk, M.F.; Rasmuson, M.A.

1998-01-01

Legal aspects of ownership of publicly traded companies in Canada are explored, with particular emphasis on transactions involving 'related parties'. In this context, Policy 9.1 of the Ontario Securities Commission is examined. The policy seeks to enhance minority shareholder protection by providing for independent valuation, majority of minority approval, enhanced disclosure and review of substantial transactions by independent directors. This paper focuses on four types of transactions governed by Policy 9.1, i.e. insider bids, issuer bids, going private transactions, related party transactions and the recent proposed rule reformulation proposed by the Ontario Securities Commission (OSC)

Preparation of new phthalocyanine complexes of some rare-earth elements

International Nuclear Information System (INIS)

Sugimoto, Hiroshi; Higashi, Teruaki; Mori, Masayasu

1982-01-01

The reaction of tris(1,3-diphenyl-1,3-propanedionato) complexes of heavier rare-earth elements, M 3+ (dbm) 3 and lithium phthalocyaninato (2-), Li 2 (pc) gave two types of new stable phthalocyanine complexes, [M 3+ (pc)(dbm)(dbmH)] and [M 3+ (pc)(dbm)] depending on the solvents used for the preparation. The structure of both types of complexes are tentatively proposed. (author)

Improved selectivity towards NO₂ of phthalocyanine-based chemosensors by means of original indigo/nanocarbons hybrid material.

Science.gov (United States)

Brunet, J; Pauly, A; Dubois, M; Rodriguez-Mendez, M L; Ndiaye, A L; Varenne, C; Guérin, K

2014-09-01

A new and original gas sensor-system dedicated to the selective monitoring of nitrogen dioxide in air and in the presence of ozone, has been successfully achieved. Because of its high sensitivity and its partial selectivity towards oxidizing pollutants (nitrogen dioxide and ozone), copper phthalocyanine-based chemoresistors are relevant. The selectivity towards nitrogen dioxide results from the implementation of a high efficient and selective ozone filter upstream the sensing device. Thus, a powdered indigo/nanocarbons hybrid material has been developed and investigated for such an application. If nanocarbonaceous material acts as a highly permeable matrix with a high specific surface area, immobilized indigo nanoparticles are involved into an ozonolysis reaction with ozone leading to the selective removal of this analytes from air sample. The filtering yields towards each gas have been experimentally quantified and establish the complete removal of ozone while having the concentration of nitrogen dioxide unchanged. Long-term gas exposures reveal the higher durability of hybrid material as compared to nanocarbons and indigo separately. Synthesis, characterizations by many complementary techniques and tests of hybrid filters are detailed. Results on sensor-system including CuPc-based chemoresistors and indigo/carbon nanotubes hybrid material as in-line filter are illustrated. Sensing performances will be especially discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Iron phthalocyanine on Cu(111): Coverage-dependent assembly and symmetry breaking, temperature-induced homocoupling, and modification of the adsorbate-surface interaction by annealing.

Science.gov (United States)

Snezhkova, Olesia; Bischoff, Felix; He, Yuanqin; Wiengarten, Alissa; Chaudhary, Shilpi; Johansson, Niclas; Schulte, Karina; Knudsen, Jan; Barth, Johannes V; Seufert, Knud; Auwärter, Willi; Schnadt, Joachim

2016-03-07

We have examined the geometric and electronic structures of iron phthalocyanine assemblies on a Cu(111) surface at different sub- to mono-layer coverages and the changes induced by thermal annealing at temperatures between 250 and 320 °C by scanning tunneling microscopy, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy. The symmetry breaking observed in scanning tunneling microscopy images is found to be coverage dependent and to persist upon annealing. Further, we find that annealing to temperatures between 300 and 320 °C leads to both desorption of iron phthalocyanine molecules from the surface and their agglomeration. We see clear evidence of temperature-induced homocoupling reactions of the iron phthalocyanine molecules following dehydrogenation of their isoindole rings, similar to what has been observed for related tetrapyrroles on transition metal surfaces. Finally, spectroscopy indicates a modified substrate-adsorbate interaction upon annealing with a shortened bond distance. This finding could potentially explain a changed reactivity of Cu-supported iron phthalocyanine in comparison to that of the pristine compound.

Improved OSC Amtec generator design to meet goals of JPL's candidate Europa Orbiter mission

International Nuclear Information System (INIS)

Schock, A.; Noravian, H.; Or, C.; Kumar, V.

1998-01-01

The preceding paper (Paper IECEC.98.244) described OSC's initial designs of AMTEC (Alkali Metal Thermal-to-Electrical Conversion) power systems, consisting of one or two generators, each with 2, 3, or 4 General Purpose Heat Source (GPHS) modules and with 16 refractory AMTEC cells containing 5 Beta Alumina Solid Electrolyte (BASE) tubes; and presented the effect of heat input and voltage output on the generator's BOM evaporator and clad temperatures and on its EOM system efficiency and power output. Comparison of the computed results with JPL's goals for the Europa Orbiter mission showed that all of the initial 16-cell design options yielded either excessive evaporator and clad temperatures or insufficient EOM power to satisfy the JPL-specified mission goals. The present paper describes modified OSC generator designs with different numbers of AMTEC cells, cell diameters, cell lengths, cell materials, BASE tube lengths, and number of tubes per cell. These efforts succeeded in identifying generator designs with only half the number of AMTEC cells which -- for the same assumptions -- can produce EOM power outputs substantially in excess of JPL's goals for NASA's Europa Orbiter mission while operating well below the prescribed BOM limits on evaporator and clad temperature; and revealed that lowering the emissivity of the generator's housing to raise the cells' condenser temperatures can achieve substantial additional performance improvement. Finally, the paper culminates in programmatic recommendations

Impact of the Anchoring Ligand on Electron Injection and Recombination Dynamics at the Interface of Novel Asymmetric Push-Pull Zinc Phthalocyanines and TiO2

NARCIS (Netherlands)

Sharma, Divya; Steen, Gerrit Willem; Korterik, Jeroen P.; Garcia-Iglesias, M.; Vazquez, P; Torres, T.; Herek, Jennifer Lynn; Huijser, Jannetje Maria

2013-01-01

Phthalocyanines are promising photosensitizers for dye-sensitized solar cells (DSSCs). A parameter that has been problematic for a long time involves electron injection (EI) into the TiO2. The development of push-pull phthalocyanines shows great potential to improve the ratio of EI to back electron

In search of the main properties of phthalocyanines participating in toxicity against cyanobacteria

Czech Academy of Sciences Publication Activity Database

Jančula, Daniel; Maršálek, Blahoslav; Novotná, Zlatica; Černý, J.; Karásková, M.; Rakušan, J.

2009-01-01

Roč. 77, č. 11 (2009), s. 1520-1525 ISSN 0045-6535 R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516 Keywords : phthalocyanine s * cyanobycteria * toxicity Subject RIV: EF - Botanics Impact factor: 3.253, year: 2009

Effect of mixed-sulfonated aluminium phthalocyanine on human skin fibroblasts for photodynamic therapy

CSIR Research Space (South Africa)

Ndhundhuma, IM

2008-08-01

Full Text Available of the study was to evaluate the effect of mixed-sulfonated aluminium phthalocyanine (AlPcSmix) used as photosensitizers for PDT, determined by changes in cell morphology and cell viability of human skin fibroblasts (WS1). Methods. Cells incubated with 5, 10...

Comparison of chemical changes during photooxidation of polypropylene film and filament containing phthalocyanine pigment

International Nuclear Information System (INIS)

Ahmadi, Z.; Haghighat Kish, M.; Kotak, R.; Katbab, A. A.

2008-01-01

Photooxidation as an important process, which significantly affects the service life of the polypropylene products, has been the subject of much theoretical and experimental study. Pigments used often change the light stabilities of polypropylene. Out-door applications of pigmented polypropylene are now increasingly developed in products such as artificial grass. The aim of this work is to examine the effect of photo-oxidation on the structure of isotactic polypropylene (iPP) in film and filament forms, where phthalocyanine pigment is used. For production of films and filaments, iPP granules with MFI 25 g/10 min were used, with and without phthalocyanine pigment. Samples were exposed to xenon lamp for various time lengths. The extent of the changes in chemical and structural parameters was examined by differential scanning calorimetry, Fourier transform infrared spectroscopy and wide angle x-ray diffraction. The results show that carbonyl and hydroperoxide indices increase during the exposure to the radiation. The changes in melting points of the samples were not significant after irradiation process. The effects of phthalocyanine pigment in the photooxidation of film and filament were different. Crystalline fractions of the non-pigmented filament samples decreased during the irradiation time while increased in film samples. Build up of hydroperoxide and carbonyl group in filament was higher than in film samples; that could be due to the differences in structural parameters. Crystallinity variations during photooxidation are related to the nucleation effect of the pigment, chemical crystallization and phase transformation

Comparison of Chemical Changes During Photooxidation of Polypropylene Film and Filament Containing Phthalocyanine Pigment

Directory of Open Access Journals (Sweden)

Z. Ahmadi

2008-02-01

Full Text Available Photooxidation as an important process, which significantly affects the service life of the polypropylene products, has been the subject of much theoretical and experimental study. Pigments used often change the light stabilities of polypropylene. Out-door applications of pigmented polypr-opylene are now increasingly developed in products such as artificial grass. The aim of this work is to examine the effect of photo-oxidation on the structure of isotactic polypropylene (iPP in film and filament forms, where phthalocyanine pigment is used. For production of films and filaments, iPP granules with MFI 25 g/10min were used, with and without phthalocyanine pigment. Samples were exposed to xenon lamp for various time lengths. The extent of the changes in chemical and structural parameters was examined by differential scanning calorimetry, Fourier transform infrared spectroscopy and wide angle x-ray diffraction. The results show that carbonyl and hydroperoxide indices increase during the exposure to the radiation. The changes in melting points of the samples were not significant after irradiation process. The effects of phthalocyanine pigment in the photooxidation of filmand filament were different. Crystalline fractions of the non-pigmented filament samples decreased during the irradiation time while increased in film samples. Build up of hydroperoxide and carbonyl group in filament was higher than in film samples; that could be due to the differences in structural parameters. Crystallinity variations during photooxidation are related to the nucleation effect of the pigment, chemical crystallization and phase transformation.

Permanent antistatic phthalocyanine/epoxy nanocomposites – Influence of crosslinking agent, solvent and processing temperature

NARCIS (Netherlands)

Yuan, M.; Brokken-Zijp, J.C.M.; With, de G.

2010-01-01

Cross-linked epoxy matrices containing small amounts of semi-conductive phthalocyanine (Phthalcon) nanoparticles were prepared using different crosslinking agents and processing temperatures. A starting mixture containing an optimum dispersion of these nanoparticles and with an almost equal and

Optical properties of zinc phthalocyanine thin films prepared by pulsed laser deposition

Czech Academy of Sciences Publication Activity Database

Novotný, Michal; Bulíř, Jiří; Bensalah-Ledoux, A.; Guy, S.; Fitl, P.; Vrňata, M.; Lančok, Ján; Moine, B.

2014-01-01

Roč. 117, č. 1 (2014), 377-381 ISSN 0947-8396 R&D Projects: GA ČR(CZ) GAP108/11/1298 Grant - others:AVČR(CZ) M100101271 Institutional support: RVO:68378271 Keywords : optical properties * zinc phthalocyanine * laser deposition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.704, year: 2014

Photodynamic effects of 31 different phthalocyanines on a human keratinocyte cell line

Czech Academy of Sciences Publication Activity Database

Jančula, Daniel; Maršálek, Blahoslav; Babica, Pavel

2013-01-01

Roč. 93, č. 6 (2013), s. 870-874 ISSN 0045-6535 R&D Projects: GA TA ČR TA01010356 Grant - others:European Commission(XE) FP/2007-2013 no.2SGA2858 Institutional support: RVO:67985939 Keywords : phthalocyanine s * photodynamics * toxicity Subject RIV: EF - Botanics Impact factor: 3.499, year: 2013

Synthesis and spectral properties of axially substituted zirconium(IV) and hafnium(IV) water soluble phthalocyanines in solutions

International Nuclear Information System (INIS)

Gerasymchuk, Y.S.; Volkov, S.V.; Chernii, V.Ya.; Tomachynski, L.A.; Radzki, St.

2004-01-01

Methods of synthesis of novel water soluble axially substituted Zr(IV) and Hf(IV) phthalocyanines with gallic, 5-sulfosalicyllic, oxalic acids, and methyl ester of gallic acid as axial ligands coordinated to the central atom metal of phthalocyanine are presented. The absorption spectra of complex solutions in various solvents were characterized. The dependence of the spectral red shift from Reichardt's empirical polarity parameter is described. The deviation from the linearity of Beer-Bouguer-Lambert law was investigated for the range of concentration 5x10 -6 to 10x10 -5 M. Fluorescent properties of axially substituted phthalocyaninato metal complexes in DMSO solutions were investigated

The influence of phthalocyanine aggregation in complexes with CdSe/ZnS quantum dots on the photophysical properties of the complexes

Directory of Open Access Journals (Sweden)

Irina V. Martynenko

2016-07-01

Full Text Available The formation of nonluminescent aggregates of aluminium sulfonated phthalocyanine in complexes with CdSe/ZnS quantum dots causes a decrease of the intracomplex energy transfer efficiency with increasing phthalocyanine concentration. This was confirmed by steady-state absorption and photoluminescent spectroscopy. A corresponding physical model was developed that describes well the experimental data. The results can be used at designing of QD/molecule systems with the desired spatial arrangement for photodynamic therapy.

Effects of spin–orbit coupling and many-body correlations in STM transport through copper phthalocyanine

Directory of Open Access Journals (Sweden)

Benjamin Siegert

2015-12-01

Full Text Available The interplay of exchange correlations and spin–orbit interaction (SOI on the many-body spectrum of a copper phtalocyanine (CuPc molecule and their signatures in transport are investigated. We first derive a minimal model Hamiltonian in a basis of frontier orbitals that is able to reproduce experimentally observed singlet–triplet splittings. In a second step SOI effects are included perturbatively. Major consequences of the SOI are the splitting of former degenerate levels and a magnetic anisotropy, which can be captured by an effective low-energy spin Hamiltonian. We show that scanning tunneling microscopy-based magnetoconductance measurements can yield clear signatures of both these SOI-induced effects.

'Hello, my name is Gabriel, I am the house officer, may I examine you?' or the Objective Santa Christmas Examination (OSCE).

Science.gov (United States)

Wood, D; Roberts, T; Bradley, P; Lloyd, D; O'Neill, P

1999-12-01

To design a clinical examination of high content validity suitable for use as a formative assessment tool with pre-registration house officers (PRHO'S) towards the end of their first house officer post. A multicentre collaboration between four UK medical schools who offer undergraduate curricula which are problem-based, systems-based, patient-orientated, student-centred, jargon-laden and utterly staff-bewildering. An objective structured clinical examination (OSCE) which is suitable for use with graduates of UK medical schools. It assesses the knowledge, skills and attitudes essential for future careers in a hierarchical system where protecting the senior staff from all forms of irritation is paramount. PRHO'S who excel in this examination get better references. The OSCE format can be used to provide 'real-life' scenarios appropriate to the season.

Unexpected Rotamerism at the Origin of a Chessboard Supramolecular Assembly of Ruthenium Phthalocyanine.

Science.gov (United States)

Mattioli, Giuseppe; Larciprete, Rosanna; Alippi, Paola; Bonapasta, Aldo Amore; Filippone, Francesco; Lacovig, Paolo; Lizzit, Silvano; Paoletti, Anna Maria; Pennesi, Giovanna; Ronci, Fabio; Zanotti, Gloria; Colonna, Stefano

2017-11-16

We have investigated the formation and the properties of ultrathin films of ruthenium phthalocyanine (RuPc) 2 vacuum deposited on graphite by scanning tunneling microscopy and synchrotron photoemission spectroscopy measurements, interpreted in close conjunction with ab initio simulations. Thanks to its unique dimeric structure connected by a direct Ru-Ru bond, (RuPc) 2 can be found in two stable rotameric forms separated by a low-energy barrier. Such isomerism leads to a peculiar organization of the molecules in flat, horizontal layers on the graphite surface, characterized by a chessboard-like alternation of the two rotamers. Moreover, the molecules are vertically connected to form π-stacked columnar pillars of akin rotamers, compatible with the high conductivity measured in (RuPc) 2 powders. Such features yield an unprecedented supramolecular assembly of phthalocyanine films, which could open interesting perspectives toward the realization of new architectures of organic electronic devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Environmentally friendly inhibition of pathogenic bacteria and algae propagation due phthalocyanine agents

International Nuclear Information System (INIS)

Rihova Ambrozova, J.; Bezdekova, E.; Louckova, E.; Nekovarova, J.

2007-01-01

From 2004, in the laboratory of The Institute of Chemical Technology in Prague is being solved the project FT-TA/034 'Environmentally friendly inhibition of pathogenic bacteria and algae propagation in the circulatory cooling systems of nuclear power stations and in other similar technological facilities' to determine effects of phthalocyanine agents. The project bearer is VUOS, Inc. in Rybitvi (Research Institute for Organic Synthesis Inc.), where are the new phthalocyanines synthesized. The aimed goal of the research is environmentally friendly liquidation of bacteria and algae by means of photodynamic generated singlet oxygen through impact of solar radiation in the circulation cooling waters of various technical and technological systems. The principle of the problem outlined is the applying of phthalocyanine agents on samples of pure bacterial, anabaenas and algae cultures to estimate the inhibition effect on the organism exposed. In the course of solution, it is assumed that in such way conducted inhibition of bacteria, anabaenas and algae as well of their proliferation would replace routinely used bactericidal and algicidal preparations, which demand permanent dosing into circulating waters or perhaps from time to time an application of shocking doses. The particular algicidal and bactericidal agents represents in this case in situ emerging singlet oxygen, that is harmless to water biocenoses and whose presence in the water is no reason to ban the outflow of waters treated in such a way into water streams. The goal should be also a direct estimation of the effect those agents on cooling waters samples e. g. from the nuclear power plant systems. The purpose of the tests performance is also elimination of filamentous green algae, emerging in the systems cooling towers. The applied preparations are not toxic and do not burden the living environment, they contain no substances interacting with surface materials of structures in the circulatory cooling circuit

Surface properties of self-assembled monolayer films of tetra-substituted cobalt, iron and manganese alkylthio phthalocyanine complexes

Energy Technology Data Exchange (ETDEWEB)

Akinbulu, Isaac Adebayo; Khene, Samson [Department of Chemistry, Rhodes University, Grahamstown 6140 (South Africa); Nyokong, Tebello, E-mail: t.nyokong@ru.ac.z [Department of Chemistry, Rhodes University, Grahamstown 6140 (South Africa)

2010-09-30

Self-assembled monolayer (SAM) films of iron (SAM-1), cobalt (SAM-2) and manganese (SAM-3) phthalocyanine complexes, tetra-substituted with diethylaminoethanethio at the non-peripheral positions, were formed on gold electrode in dimethylformamide (DMF). Electrochemical, impedimentary and surface properties of the SAM films were investigated. Cyclic voltammetry was used to investigate the electrochemical properties of the films. Ability of the films to inhibit common faradaic processes on bare gold surface (gold oxidation, solution redox chemistry of [Fe(H{sub 2}O){sub 6}]{sup 3+}/[Fe(H{sub 2}O){sub 6}]{sup 2+} and underpotential deposition (UDP) of copper) was investigated. Electrochemical impedance spectroscopy (EIS), using [Fe(CN){sub 6}]{sup 3-/4-} redox process as a probe, offered insights into the electrical properties of the films/electrode interfaces. Surface properties of the films were probed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The films were employed for the electrocatalytic oxidation of the pesticide, carbofuran. Electrocatalysis was evidenced from enhanced current signal and less positive oxidation potential of the pesticide on each film, relative to that observed on the bare gold electrode. Mechanism of electrocatalytic oxidation of the pesticide was studied using rotating disc electrode voltammetry.

Student´s self-assessment of clinical competence and objective clinical performance in OSCE evaluation

OpenAIRE

Jünger, J; Schellberg, D; Nikendei, C

2006-01-01

[english] Overestimating one's clinical competence can be dangerous to patient's safety. Therefore the goal of this study was to identify students with high confidence in their own clinical competence but low performance in objective assessment. 171 students in the 14 week course in internal medicine completed the clinical skills-related self-assessment expectations (SE) and were tested in a 12 station OSCE. Both measures were obtained within three days. In total we identified 16% of students...

Combination of hyperthermia and photodynamic therapy on mesenchymal stem cell line treated with chloroaluminum phthalocyanine magnetic-nanoemulsion

Energy Technology Data Exchange (ETDEWEB)

Paula, Leonardo B. de [Departamento de Química, Centro de Nanotecnologia e Engenharia Tecidual, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040-901 (Brazil); Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14049-900 (Brazil); Primo, Fernando L. [Departamento de Química, Centro de Nanotecnologia e Engenharia Tecidual, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040-901 (Brazil); Nanophoton Company, SUPERA Innovation and Technology Park, Av. Doutora Nadir de Aguiar, 1805, Universidade de São Paulo, Ribeirão Preto, P 14056-680 (Brazil); Pinto, Marcelo R. [Departamento de Química, Laboratório de Enzimologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040-901 (Brazil); Morais, Paulo C. [Instituto de Física, Universidade de Brasília, Brasília, DF 70910-900 (Brazil); School of Automation, Huazhong University of Science and Technology, Wuhan 430074 (China); and others

2015-04-15

The present study reports on the preparation and the cell viability assay of two nanoemulsions loaded with magnetic nanoparticle and chloroaluminum phthalocyanine. The preparations contain equal amount of chloroaluminum phthalocyanine (0.05 mg/mL) but different contents of magnetic nanoparticle (0.15×10{sup 13} or 1.50×10{sup 13} particle/mL). The human bone marrow mesenchymal stem cell line was used as the model to assess the cell viability and this type of cell can be used as a model to mimic cancer stem cells. The cell viability assays were performed in isolated as well as under combined magnetic hyperthermia and photodynamic therapy treatments. We found from the cell viability assay that under the hyperthermia treatment (1 MHz and 40 Oe magnetic field amplitude) the cell viability reduction was about 10%, regardless the magnetic nanoparticle content within the magnetic nanoparticle/chloroaluminum phthalocyanine formulation. However, cell viability reduction of about 50% and 60% were found while applying the photodynamic therapy treatment using the magnetic nanoparticle/chloroaluminum phthalocyanine formulation containing 0.15×10{sup 13} or 1.50×10{sup 13} magnetic particle/mL, respectively. Finally, an average reduction in cell viability of about 66% was found while combining the hyperthermia and photodynamic therapy treatments. - Highlights: • Current protocols in nanotechnology allow for biocompatible magnetic nanoparticles being associated with photosensitizer photoactive drugs, which could lead to perfectly controlled drug release. • The combination of the HPT and PDT therapies can be useful to develop further protocols for both advanced in vitro and in vivo assays. • Magnetic nanodevices associated with therapies have led to the decreased of proliferation of cell population that provides a favorable environment for tumor progression.

Combination of hyperthermia and photodynamic therapy on mesenchymal stem cell line treated with chloroaluminum phthalocyanine magnetic-nanoemulsion

International Nuclear Information System (INIS)

Paula, Leonardo B. de; Primo, Fernando L.; Pinto, Marcelo R.; Morais, Paulo C.

2015-01-01

The present study reports on the preparation and the cell viability assay of two nanoemulsions loaded with magnetic nanoparticle and chloroaluminum phthalocyanine. The preparations contain equal amount of chloroaluminum phthalocyanine (0.05 mg/mL) but different contents of magnetic nanoparticle (0.15×10 13 or 1.50×10 13 particle/mL). The human bone marrow mesenchymal stem cell line was used as the model to assess the cell viability and this type of cell can be used as a model to mimic cancer stem cells. The cell viability assays were performed in isolated as well as under combined magnetic hyperthermia and photodynamic therapy treatments. We found from the cell viability assay that under the hyperthermia treatment (1 MHz and 40 Oe magnetic field amplitude) the cell viability reduction was about 10%, regardless the magnetic nanoparticle content within the magnetic nanoparticle/chloroaluminum phthalocyanine formulation. However, cell viability reduction of about 50% and 60% were found while applying the photodynamic therapy treatment using the magnetic nanoparticle/chloroaluminum phthalocyanine formulation containing 0.15×10 13 or 1.50×10 13 magnetic particle/mL, respectively. Finally, an average reduction in cell viability of about 66% was found while combining the hyperthermia and photodynamic therapy treatments. - Highlights: • Current protocols in nanotechnology allow for biocompatible magnetic nanoparticles being associated with photosensitizer photoactive drugs, which could lead to perfectly controlled drug release. • The combination of the HPT and PDT therapies can be useful to develop further protocols for both advanced in vitro and in vivo assays. • Magnetic nanodevices associated with therapies have led to the decreased of proliferation of cell population that provides a favorable environment for tumor progression

Interaction of nitrogen dioxide with sulfonamide-substituted phthalocyanines: Towards NO2 gas sensor

Czech Academy of Sciences Publication Activity Database

Pochekailov, Sergii; Nožár, Juraj; Nešpůrek, Stanislav; Rakušan, J.; Karásková, M.

2012-01-01

Roč. 169, 5 July (2012), s. 1-9 ISSN 0925-4005 R&D Projects: GA AV ČR KAN400720701; GA MPO FR-TI1/144 Institutional research plan: CEZ:AV0Z40500505 Keywords : phthalocyanine * sulfonamide * nitrogen dioxide Subject RIV: CG - Electrochemistry Impact factor: 3.535, year: 2012

The electrochemical behavior of cobalt phthalocyanine/platinum as methanol-resistant oxygen-reduction electrocatalysts for DMFC

Energy Technology Data Exchange (ETDEWEB)

Lu, Yuhao; Reddy, Ramana G. [Department of Metallurgical and Materials Engineering, The University of Alabama, P.O. Box 870202, Tuscaloosa, AL 35487 (United States)

2007-02-01

The electrochemical behavior of cobalt phthalocyanine/platinum as methanol-resistant oxygen-reduction electrocatalyst for DMFC was investigated. Platinum was chemically deposited on the carbon-supported cobalt phthalocyanine (CoPc), and then it was heat-treated in high purity nitrogen at 300 C, 635 C and 980 C. In order to evaluate the electrocatalytic behavior of CoPc-Pt/C, the PtCo/C and Pt/C as reference catalysts were employed. TGA, XRD, EDAX, XPS and electrochemical experiments were used to study the thermal stability, crystal structure, physical characterization and electrochemical behavior of these catalysts. These catalysts exhibited similar electrocatalytic activity for oxygen reaction in 0.5 M H{sub 2}SO{sub 4} solution. In methanol tolerance experiments, Pt/C, PtCo/C and CoPc-Pt/C heated at 980 C were active for the methanol oxidation reaction (MOR). The presence of Co did not improve resistance to methanol poisoning. However, the CoPc-Pt/C after 300 C or 635 C heat-treatment demonstrated significant inactivity for MOR, hence they have a good ability to resist methanol poisoning. The current study indicated that the macrocyclic structure of phthalocyanine is the most important factor to improve the methanol tolerance of CoPc-Pt/C as the oxygen-reduction reaction (ORR) electrocatalyst. The CoPc-Pt based catalyst should be a good alternation for oxygen electro-reduction reaction in DMFC. (author)

The effect of NO2 on spectroscopic and structural properties of evaporated ruthenium phthalocyanine dimer

International Nuclear Information System (INIS)

Alagna, Lucilla; Capobianchi, Aldo; Paoletti, Anna Maria; Pennesi, Giovanna; Rossi, Gentilina; Casaletto, Maria Pia; Generosi, Amanda; Paci, Barbara; Albertini, Valerio Rossi

2006-01-01

The chemical interaction between NO 2 gas and dimeric ruthenium phthalocyanine (RuPc) 2 (Pc = phthalocyanine ligand) films has been investigated by different techniques: UV-Visible spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and Extended X-ray Absorption Fine Structure (EXAFS). The optical spectra in the Q band region (700-500 nm) registered 'in situ' enabled to follow the evolution of the process in real time indicating that a two steps reaction, showing two clear isosbestic points, occurs. The first phase was essentially characterised by: (a) the rapid disappearance of the 608 and 420 nm shoulders; (b) the intensity decrease of the main absorption peak and (c) the appearance of a new adsorption band centred around 510 nm. In the second step the remarkable feature is a further lowering of the main peak with the simultaneous decrease of the new 510 nm absorption. These spectral changes suggested that a chemical reaction occurred between NO 2 and ruthenium phthalocyanine with the formation of a radical species due to the macrocycle oxidation. The kinetics indicates that the adsorption of gas by the evaporated (RuPc) 2 film is a complex process involving more than one independent mechanism. XPS and EXAFS spectra collected before and after gas exposure showed that the central metals (Ru) were also involved in the oxidation process. The reversibility of the process has been also tested by treating the films at different temperatures, the original optical spectrum being not completely recovered

Fabrication and characterization of organic solar cells using metal complex of phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Kida, Tomoyasu, E-mail: suzuki@mat.usp.ac.jp; Suzuki, Atsushi, E-mail: suzuki@mat.usp.ac.jp; Akiyama, Tsuyoshi, E-mail: suzuki@mat.usp.ac.jp; Oku, Takeo, E-mail: suzuki@mat.usp.ac.jp [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

2015-02-27

Fabrication and characterization of organic solar cells using shuttle-cock-type phthalocyanines were carried out. Photovoltaic properties of the solar cells with inverted structures were investigated by current density-voltage characteristics. Effects of phase transition between H and J aggregates on the photovoltaic and optical properties were investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed.

Filler size effects on the conductivity of polymer nanocomposites: semiconductive phthalocyanine nanoparticles in epoxy matrices

NARCIS (Netherlands)

Yuan, M.; Brokken-Zijp, J.C.M.; Huijbregts, L.J.; With, de G.

2008-01-01

Three Cobalt(III) phthalocyanine (Phthalcon) powders with different particle sizes and chemical compositions, but almost equal XRD spectra and powder conductivity were synthesized and used as conductive fillers in crosslinked epoxy matrices. Two of these Phthalcons are new compounds. The relation

Photochemical oxygen reduction by zinc phthalocyanine and silver/gold nanoparticle incorporated silica thin films

Energy Technology Data Exchange (ETDEWEB)

Pal, Manas; Ganesan, Vellaichamy, E-mail: velganesh@yahoo.com; Azad, Uday Pratap

2012-12-15

Silver or gold nanoparticles are synthesized using a borohydride reduction method and are anchored simultaneously into/onto the mercaptopropyl functionalized silica. Later, zinc phthalocyanine is adsorbed onto the above materials. Thin films of these materials are prepared by coating an aqueous colloidal suspension of the respective material onto glass plates. Visible light irradiation of these films in oxygen saturated, stirred aqueous solutions effectively reduces oxygen to hydrogen peroxide. The photocatalytic reduction of oxygen is explained on the basis of the semiconducting properties of the silica films. The back electron transfer reaction is largely prevented by means of a sacrificial electron donor, triethanolamine. - Highlights: Black-Right-Pointing-Pointer Zinc phthalocyanine adsorbed silica materials were prepared. Black-Right-Pointing-Pointer Thin films of these materials photocatalytically reduce oxygen. Black-Right-Pointing-Pointer The photocatalysis is explained based on semiconductor properties of the materials. Black-Right-Pointing-Pointer Metal nanoparticles increase the photocatalytic efficiency of the materials.

Evaluation of a multi-methods approach to the collection and dissemination of feedback on OSCE performance in dental education.

Science.gov (United States)

Wardman, M J; Yorke, V C; Hallam, J L

2018-05-01

Feedback is an essential part of the learning process, and students expect their feedback to be personalised, meaningful and timely. Objective Structured Clinical Examination (OSCE) assessments allow examiners to observe students carefully over the course of a number of varied station types, across a number of clinical knowledge and skill domains. They therefore present an ideal opportunity to record detailed feedback which allows students to reflect on and improve their performance. This article outlines two methods by which OSCE feedback was collected and then disseminated to undergraduate dental students across 2-year groups in a UK dental school: (i) Individual written feedback comments made by examiners during the examination, (ii) General audio feedback recorded by groups of examiners immediately following the examination. Evaluation of the feedback was sought from students and staff examiners. A multi-methods approach utilising Likert questionnaire items (quantitative) and open-ended feedback questions (qualitative) was used. Data analysis explored student and staff perceptions of the audio and written feedback. A total of 131 students (response rate 68%) and 52 staff examiners (response rate 83%) completed questionnaires. Quantitative data analysis showed that the written and audio formats were reported as a meaningful source of feedback for learning by both students (93% written, 89% audio) and staff (96% written, 92% audio). Qualitative data revealed the complementary nature of both types of feedback. Written feedback gives specific, individual information whilst audio shares general observations and allows students to learn from others. The advantages, limitations and challenges of the feedback methods are discussed, leading to the development of an informed set of implementation guidelines. Written and audio feedback methods are valued by students and staff. It is proposed that these may be very easily applied to OSCEs running in other dental schools. �

Generation of Transparent Oxygen Evolution Electrode Consisting of Regularly Ordered Nanoparticles from Self-Assembly Cobalt Phthalocyanine as a Template

KAUST Repository

Ziani, Ahmed

2016-11-04

The decoration of (photo)electrodes for efficient photoresponse requires the use of electrocatalysts with good dispersion and high transparency for efficient light absorption by the photoelectrode. As a result of the ease of thermal evaporation and particulate self-assembly growth, the phthalocyanine molecular species can be uniformly deposited layer-by-layer on the surface of substrates. This structure can be used as a template to achieve a tunable amount of catalysts, high dispersion of the nanoparticles, and transparency of the catalysts. In this study, we present a systematic study of the structural and optical properties, surface morphologies, and electrochemical oxygen evolution reaction (OER) performance of cobalt oxide prepared from a phthalocyanine metal precursor. Cobalt phthalocyanine (CoPc) films with different thicknesses were deposited by thermal evaporation on different substrates. The films were annealed at 400 °C in air to form a material with the cobalt oxide phase. The final Co oxide catalysts exhibit high transparency after thermal treatment. Their OER measurements demonstrate well expected mass activity for OER. Thermally evaporated and treated transition metal oxide nanoparticles are attractive for the functionalization of (photo)anodes for water oxidation.

Effects of analytes on the fluorescence properties of CdTe@ZnS quantum dots decorated with cobalt tetraamino-phthalocyanine

Energy Technology Data Exchange (ETDEWEB)

Adegoke, Oluwasesan; Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za

2014-02-15

In this work, we have carried out an investigation on the effects of different biologically active analytes on the fluorescence response of glutathione-capped CdTe@ZnS quantum dots (QDs)-colbalt tetraamino-phthalocyanine nanoconjugate system. Firstly, fluorescence quenching occurred. Experimental results showed that some analytes either “turned on”, others further quenched or showed no effect on the fluorescence emission of the nanoprobe. -- Highlights: • A conjugate between CdTe@ZnS quantum dots and cobalt tetraamino-phthalocyanine is formed. • The fluorescence of quantum dots is quenched on coordination. • The fluorescence is enhanced by analytes such as cystamine, hydroxyl radical, glutathione, and perchlorate.

Organic phthalocyanine films with high mobilities for efficient field-effect transistor switches

Czech Academy of Sciences Publication Activity Database

Schauer, F.; Zhivkov, I.; Nešpůrek, Stanislav

266-269, 1-3 (2000), s. 999-1003 ISSN 0022-3093. [International Conference on Amorphous and Microcrystalline Semiconductors /18./. Snowbird, 23.08.1999-27.08.1999] R&D Projects: GA MŠk OC 518.10; GA AV ČR KSK2050602 Institutional research plan: CEZ:AV0Z4050913 Keywords : phthalocyanine * charge mobility * field-effect transistor Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.269, year: 2000

Atomic contributions to the valence band photoelectron spectra of metal-free, iron and manganese phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Bidermane, I., E-mail: ieva.bidermane@physics.uu.se [Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala (Sweden); Institut des Nanosciences de Paris, UPMC Univ. Paris 06, CNRS UMR 7588, F-75005 Paris (France); Brumboiu, I.E. [Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala (Sweden); Totani, R. [Department of Physical and Chemical Sciences, University of L’Aquila, Via Vetoio, Coppito, I-67010 L’Aquila (Italy); Grazioli, C. [CNR-IOM, Laboratorio TASC, ss. 14 km. 163.5, Basovizza, 34149 Trieste (Italy); Departement of Chemical and Pharmaceutical Sciences, University of Trieste (Italy); Shariati-Nilsson, M.N.; Herper, H.C.; Eriksson, O.; Sanyal, B. [Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala (Sweden); Ressel, B. [University of Nova Gorica, Vipavska Cesta 11c, 5270 Ajdovščina (Slovenia); Simone, M. de [CNR-IOM, Laboratorio TASC, ss. 14 km. 163.5, Basovizza, 34149 Trieste (Italy); Lozzi, L. [Department of Physical and Chemical Sciences, University of L’Aquila, Via Vetoio, Coppito, I-67010 L’Aquila (Italy); Brena, B.; Puglia, C. [Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala (Sweden)

2015-11-15

Highlights: • In detail comparison between the valence band structure of H{sub 2}Pc, FePc and MnPc. • Comparison between the gas phase samples and thin evaporated films on Au (1 1 1). • Detailed analysis of the atomic orbital contributions to the valence band features. • DFT/HSE06 study of the valence band electronic structure of H{sub 2}Pc, FePc and MnPc. - Abstract: The present work reports a photoelectron spectroscopy study of the low-energy region of the valence band of metal-free phthalocyanine (H{sub 2}Pc) compared with those of iron phthalocyanine (FePc) and manganese phthalocyanine (MnPc). We have analysed in detail the atomic orbital composition of the valence band both experimentally, by making use of the variation in photoionization cross-sections with photon energy, and theoretically, by means of density functional theory. The atomic character of the Highest Occupied Molecular Orbital (HOMO), reflected on the outermost valence band binding energy region, is different for MnPc as compared to the other two molecules. The peaks related to the C 2p contributions, result in the HOMO for H{sub 2}Pc and FePc and in the HOMO-1 for MnPc as described by the theoretical predictions, in very good agreement with the experimental results. The DFT simulations, discerning the atomic contribution to the density of states, indicate how the central metal atom interacts with the C and N atoms of the molecule, giving rise to different partial and total density of states for these three Pc molecules.

Radiation synthesis and characterization of zinc phthalocyanine composite based on 2-hydroxyethyl methacrylate/methyl methacrylate copolymer

International Nuclear Information System (INIS)

Abdel Ghaffar, A.M.; Youssef, Tamer E.; Mohamed, Hanan H.

2016-01-01

The synthesis and characterization of new 2-hydroxyethyl methacrylate-co-methyl methacrylate/zinc phthalocyanine composite Poly(HEMA/MMA/ZnPc) is described for the first time in this study. The aim of this research is to present possibility of radiation synthesis of the newly zinc phthalocyanine composites as potential candidates for wide range of applications. Gel (%) and swelling for Poly(hydroxyethyl methacrylate) Poly(HEMA) and the based Poly(hydroxyethyl methacrylate/methyl methacrylate) copolymer Poly(HEMA/MMA) with different composition 100/0, 95/5, 90/10 and 80/20 wt % were evaluated. It was found that Poly(HEMA/MMA) copolymer with composition 95/5 wt % characterized by its high swelling property at pH 7.4. The prepared composites I and II Poly(HEMA/MMA/ZnPc) with composition (95/5/1 wt%) and (95/5/1.5 wt%) respectively have been characterized by FTIR and TGA. The effect of gamma irradiation on the chemical properties of composite I was described. It is observed that the Zinc phthalocyanine with low concentration 1 wt % enhance chemical, thermal properties and stabilization against gamma radiation of the prepared composite I. - Highlights: • The preparation of Poly(HEMA/MMA/ZnPc) by radiation forming modified composites. • The low concentration of ZcPc (1 or 1.5 wt %) lead to form outstanding properties. • These composites are a potential candidate for wide range of applications.

Radiation synthesis and characterization of zinc phthalocyanine composite based on 2-hydroxyethyl methacrylate/methyl methacrylate copolymer

Energy Technology Data Exchange (ETDEWEB)

Abdel Ghaffar, A.M., E-mail: am_abdelghaffar@yahoo.com [Radiation Research of Polymer Chemistry Department, Industrial Irradiation Division, National Center for Radiation Research and Technology, Atomic Energy Authority P.O. Box 29, Nasr City, Cairo (Egypt); Youssef, Tamer E. [Applied Organic Chemistry Department, Chemical Industries Research Division, National Research Center, Dokki, Cairo, 12622 (Egypt); Chemical and Materials Engineering Department, Faculty of Engineering, King Abdulaziz University, P.O. Box 80204, Jeddah, 21589 (Saudi Arabia); Mohamed, Hanan H. [Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, Cairo (Egypt)

2016-08-01

The synthesis and characterization of new 2-hydroxyethyl methacrylate-co-methyl methacrylate/zinc phthalocyanine composite Poly(HEMA/MMA/ZnPc) is described for the first time in this study. The aim of this research is to present possibility of radiation synthesis of the newly zinc phthalocyanine composites as potential candidates for wide range of applications. Gel (%) and swelling for Poly(hydroxyethyl methacrylate) Poly(HEMA) and the based Poly(hydroxyethyl methacrylate/methyl methacrylate) copolymer Poly(HEMA/MMA) with different composition 100/0, 95/5, 90/10 and 80/20 wt % were evaluated. It was found that Poly(HEMA/MMA) copolymer with composition 95/5 wt % characterized by its high swelling property at pH 7.4. The prepared composites I and II Poly(HEMA/MMA/ZnPc) with composition (95/5/1 wt%) and (95/5/1.5 wt%) respectively have been characterized by FTIR and TGA. The effect of gamma irradiation on the chemical properties of composite I was described. It is observed that the Zinc phthalocyanine with low concentration 1 wt % enhance chemical, thermal properties and stabilization against gamma radiation of the prepared composite I. - Highlights: • The preparation of Poly(HEMA/MMA/ZnPc) by radiation forming modified composites. • The low concentration of ZcPc (1 or 1.5 wt %) lead to form outstanding properties. • These composites are a potential candidate for wide range of applications.

Bis(tri-n-hexylsilyl oxide) silicon phthalocyanine: a unique additive in ternary bulk heterojunction organic photovoltaic devices.

Science.gov (United States)

Lessard, Benoît H; Dang, Jeremy D; Grant, Trevor M; Gao, Dong; Seferos, Dwight S; Bender, Timothy P

2014-09-10

Previous studies have shown that the use of bis(tri-n-hexylsilyl oxide) silicon phthalocyanine ((3HS)2-SiPc) as an additive in a P3HT:PC61BM cascade ternary bulk heterojunction organic photovoltaic (BHJ OPV) device results in an increase in the short circuit current (J(SC)) and efficiency (η(eff)) of up to 25% and 20%, respectively. The previous studies have attributed the increase in performance to the presence of (3HS)2-SiPc at the BHJ interface. In this study, we explored the molecular characteristics of (3HS)2-SiPc which makes it so effective in increasing the OPV device J(SC) and η(eff. Initially, we synthesized phthalocyanine-based additives using different core elements such as germanium and boron instead of silicon, each having similar frontier orbital energies compared to (3HS)2-SiPc and tested their effect on BHJ OPV device performance. We observed that addition of bis(tri-n-hexylsilyl oxide) germanium phthalocyanine ((3HS)2-GePc) or tri-n-hexylsilyl oxide boron subphthalocyanine (3HS-BsubPc) resulted in a nonstatistically significant increase in JSC and η(eff). Secondly, we kept the silicon phthalocyanine core and substituted the tri-n-hexylsilyl solubilizing groups with pentadecyl phenoxy groups and tested the resulting dye in a BHJ OPV. While an increase in JSC and η(eff) was observed at low (PDP)2-SiPc loadings, the increase was not as significant as (3HS)2-SiPc; therefore, (3HS)2-SiPc is a unique additive. During our study, we observed that (3HS)2-SiPc had an extraordinary tendency to crystallize compared to the other compounds in this study and our general experience. On the basis of this observation, we have offered a hypothesis that when (3HS)2-SiPc migrates to the P3HT:PC61BM interface the reason for its unique performance is not solely due to its frontier orbital energies but also might be due to a high driving force for crystallization.

Photovoltaic behaviour of titanyl phthalocyanine thin films and titania bilayer films

Czech Academy of Sciences Publication Activity Database

Drabik, M.; Zachary, A. M.; Choi, Y.; Hanuš, J.; Toušek, J.; Toušková, J.; Cimrová, Věra; Slavinská, D.; Biederman, H.; Hanley, L.

2008-01-01

Roč. 268, č. 1 (2008), s. 57-60 ISSN 1022-1360. [Microsymposium on Advanced Polymer Materials for Photonics and Electronics /47./. Prague, 15.07.2007-19.07.2007] R&D Projects: GA MŠk(CZ) 1M06031 Grant - others:National Science Foundation(US) CHE0241425; GA MŠk(CZ) 1P05ME754 Institutional research plan: CEZ:AV0Z40500505 Keywords : conjugated polymers * photovoltaics * phthalocyanine * thin films * titania Subject RIV: BM - Solid Matter Physics ; Magnetism

Preparation of thin phthalocyanine layers and their structural and absorption properties

Czech Academy of Sciences Publication Activity Database

Kment, Štěpán; Klusoň, Petr; Drobek, M.; Kužel, R.; Gregora, Ivan; Kohout, Michal; Hubička, Zdeněk

2009-01-01

Roč. 517, č. 17 (2009), s. 5274-5279 ISSN 0040-6090 R&D Projects: GA AV ČR KAN301370701; GA MŠk(CZ) 1M06002; GA AV ČR KAN400720701; GA ČR(CZ) GD203/08/H032 Institutional research plan: CEZ:AV0Z10100522; CEZ:AV0Z40720504 Keywords : vacuum sublimation * phthalocyanine s * sensors * thin fims Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.727, year: 2009

Importance of semicore states in GW calculations for simulating accurately the photoemission spectra of metal phthalocyanine molecules.

Science.gov (United States)

Umari, P; Fabris, S

2012-05-07

The quasi-particle energy levels of the Zn-Phthalocyanine (ZnPc) molecule calculated with the GW approximation are shown to depend sensitively on the explicit description of the metal-center semicore states. We find that the calculated GW energy levels are in good agreement with the measured experimental photoemission spectra only when explicitly including the Zn 3s and 3p semicore states in the valence. The main origin of this effect is traced back to the exchange term in the self-energy GW approximation. Based on this finding, we propose a simplified approach for correcting GW calculations of metal phthalocyanine molecules that avoids the time-consuming explicit treatment of the metal semicore states. Our method allows for speeding up the calculations without compromising the accuracy of the computed spectra.

Molecular structure effects in photodegradation of phenol and its chlorinated derivatives with phthalocyanines

Czech Academy of Sciences Publication Activity Database

Klusoň, P.; Drobek, M.; Krejčíková, S.; Krýsa, J.; Kalaji, A.; Cajthaml, Tomáš; Rakušan, J.

2008-01-01

Roč. 80, 3-4 (2008), s. 321-326 ISSN 0926-3373 R&D Projects: GA AV ČR KAN400720701 Grant - others:CZ(CZ) GD203/03/H140; Mšk(CZ) IM4531433201 Program:GD Institutional research plan: CEZ:AV0Z50200510 Keywords : phthalocyanines * phenol * chlorophenols Subject RIV: EE - Microbiology, Virology Impact factor: 4.853, year: 2008

Cobalt-phthalocyanine-derived ultrafine Co{sub 3}O{sub 4} nanoparticles as high-performance anode materials for lithium ion batteries

Energy Technology Data Exchange (ETDEWEB)

Wang, Heng-guo, E-mail: wanghengguo@cust.edu.cn; Zhu, Yanjie; Yuan, Chenpei; Li, Yanhui; Duan, Qian, E-mail: duanqian88@hotmail.com

2017-08-31

Highlights: • Transition-metal oxides nanoparticles are prepared by deriving from metal-phthalocyanine. • Co{sub 3}O{sub 4}, Fe{sub 2}O{sub 3}, and CuO nanoparticles can be prepared due to the adjustability of central metals. • This present strategy is simple, general, effective yet mass-production. • The Co{sub 3}O{sub 4} nanoparticles exhibit good lithium storage performances. - Abstract: In this work, we present a simple, general, effective yet mass-production strategy to prepare transition-metal oxides (TMOs) nanoparticles using the metal-phthalocyanine as both the precursor and the starting self-sacrificial template. As the central metals of metal-phthalocyanine are easily tunable, various TMOs nanoparticles including Co{sub 3}O{sub 4}, Fe{sub 2}O{sub 3}, and CuO have been successfully prepared by deriving from the corresponding metal-phthalocyanine. As a proof-of-concept demonstration of the application of such nanostructured TMOs, Co{sub 3}O{sub 4} nanoparticles were evaluated as anode materials for LIBs, which show high initial capacity (1132.9 mAh g{sup −1} at 0.05 A g{sup −1}), improved cycling stability (585.6 mAh g{sup −1} after 200 cycles at 0.05 A g{sup −1}), and good rate capability (238.1 mAh g{sup −1} at 2 A g{sup −1}) due to the unique properties of the ultrafine Co{sub 3}O{sub 4} nanoparticles. This present strategy might open new avenues for the design of a series of transition metal oxides using organometallic compounds for a range of applications.

Towards functionalization of graphene: in situ study of the nucleation of copper-phtalocyanine on graphene

Science.gov (United States)

Schwarz, Daniel; Henneke, Caroline; Kumpf, Christian

2016-02-01

Molecular films present an elegant way for the uniform functionalization or doping of graphene. Here, we present an in situ study on the initial growth of copper phthalocyanine (CuPc) on epitaxial graphene on Ir(111). We followed the growth up to a closed monolayer with low energy electron microscopy and selected area electron diffraction (μLEED). The molecules coexist on graphene in a disordered phase without long-range order and an ordered crystalline phase. The local topography of the graphene substrate plays an important role in the nucleation process of the crystalline phase. Graphene flakes on Ir(111) feature regions that are under more tensile stress than others. We observe that the CuPc molecules form ordered domains initially on those graphene regions that are closest to the fully relaxed lattice. We attribute this effect to a stronger influence of the underlying Ir(111) substrate for molecules adsorbed on those relaxed regions.

Towards functionalization of graphene: in situ study of the nucleation of copper-phtalocyanine on graphene

International Nuclear Information System (INIS)

Schwarz, Daniel; Henneke, Caroline; Kumpf, Christian

2016-01-01

Molecular films present an elegant way for the uniform functionalization or doping of graphene. Here, we present an in situ study on the initial growth of copper phthalocyanine (CuPc) on epitaxial graphene on Ir(111). We followed the growth up to a closed monolayer with low energy electron microscopy and selected area electron diffraction (μLEED). The molecules coexist on graphene in a disordered phase without long-range order and an ordered crystalline phase. The local topography of the graphene substrate plays an important role in the nucleation process of the crystalline phase. Graphene flakes on Ir(111) feature regions that are under more tensile stress than others. We observe that the CuPc molecules form ordered domains initially on those graphene regions that are closest to the fully relaxed lattice. We attribute this effect to a stronger influence of the underlying Ir(111) substrate for molecules adsorbed on those relaxed regions. (paper)

Synergistic enhancement of supercapacitance upon integration of nickel (II) octa[(3,5-biscarboxylate)-phenoxy] phthalocyanine with SWCNT-phenylamine

CSIR Research Space (South Africa)

Agboola, BO

2010-06-01

Full Text Available Supercapacitive behaviour of a novel functional material, nickel (II) octa [(3,5-biscarboxylate)-phenoxy] phthalocyanine (NiOBCPPc) upon covalent integration with phenylamine functionalized single-walled carbon nanotubes (SWCNT...

Changes in the Spectral Features of Zinc Phthalocyanine Induced by Nitrogen Dioxide Gas in Solution and in Solid Polymer Nanofiber Media.

Science.gov (United States)

Zugle, Ruphino; Tetteh, Samuel

2017-03-01

The changes in the spectral features of zinc phthalocyanine in the visible domain as a result of its interaction with nitrogen dioxide gas were assessed in this work. This was done both in solution and when the phthalocyanine was incorporated into a solid polystyrene polymer nanofiber matrix. The spectral changes were found to be spontaneous and marked in both cases suggesting a rapid response criterion for the detection of the gas. In particular, the functionalised nano-fabric material could serve as a practical fire alarm system as it rapidly detects the nitrogen dioxide gas generated during burning.

ELECTROCATALYTIC ACTIVITY FOR O2 REDUCTION OF UNSUBSTITUTED AND PERCHLORINATED IRON PHTHALOCYANINES ADSORBED ON AMINO-TERMINATED MULTIWALLED CARBON NANOTUBES DEPOSITED ON GLASSY CARBON ELECTRODES

OpenAIRE

CAÑETE, PAULINA; SILVA, J. FRANCISCO; ZAGAL, JOSÉ H

2014-01-01

Amino-functionalized multiwalled carbon nanotubes (MWCNT-NH2) were modified with Fe phthalocyanine (FePc) and perchlorinated Fe phthalocyanine (16(Cl)FePc) and deposited on glassy carbon electrodes (GCE). The electrocatalytic activity of these hybrid electrodes was examined for the reduction of molecular oxygen in alkaline media (0.2 M NaOH) using stationary and rotating disk electrodes. Electrodes containing 16(Cl)FePc are more active than those containing FePc. Electrodes containing CNTs ar...

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

Performance of OSC's initial Amtec generator design, and comparison with JPL's Europa Orbiter goals

International Nuclear Information System (INIS)

Schock, A.; Noravian, H.; Or, C.; Kumar, V.

1998-01-01

The procedure for the analysis (with overpotential correction) of multitube AMTEC (Alkali Metal Thermal-to-Electrical Conversion) cells described in Paper IECEC 98-243 was applied to a wide range of multicell radioisotope space power systems. System design options consisting of one or two generators, each with 2, 3, or 4 stacked GPHS (General Purpose Heat Source) modules, identical to those used on previous NASA missions, were analyzed and performance-mapped. The initial generators analyzed by OSC had 8 AMTEC cells on each end of the heat source stack, with five beta-alumina solid electrolyte (BASE) tubes per cell. The heat source and converters in the Orbital generator designs are embedded in a thermal insulation system consisting of Min-K fibrous insulation surrounded by graded-length molybdenum multifoils. Detailed analyses in previous Orbital studies found that such an insulation system could reduce extraneous heat losses to about 10%. For the above design options, the present paper presents the system mass and performance (i.e., the EOM system efficiency and power output and the BOM evaporator and clad temperatures) for a wide range of heat inputs and load voltages, and compares the results with JPL's preliminary goals for the Europa Orbiter mission to be launched in November 2003. The analytical results showed that the initial 16-cell generator designs resulted in either excessive evaporator and clad temperatures and/or insufficient power outputs to meet the JPL-specified mission goals. The computed performance of modified OSC generators with different numbers of AMTEC cells, cell diameters, cell lengths, cell materials, BASE tube lengths, and number of tubes per cell are described in Paper IECEC.98.245 in these proceedings

Sulphonated cobalt phthalocyanine-MCM-41: An active photocatalyst for degradation of 2,4-dichlorophenol

Energy Technology Data Exchange (ETDEWEB)

Zanjanchi, M.A., E-mail: zanjanchi@guilan.ac.ir [Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Namjoo St., Rasht 41335 (Iran, Islamic Republic of); Ebrahimian, A.; Arvand, M. [Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Namjoo St., Rasht 41335 (Iran, Islamic Republic of)

2010-03-15

The photocatalytic activity of sulphonated cobalt phthalocyanine immobilized onto MCM-41 was investigated for decomposition of 2,4-dichlorophenol (2,4-DCP) in aqueous solutions. Immobilization of anion sulpho-cobalt phthalocyanine to the walls of MCM-41 was performed by pre-anchorage of 3-(aminopropyl)-triethoxysilane (APTES) onto MCM-41 via post-synthesis method. X-ray diffraction, nitrogen physisorption, diffuse reflectance spectroscopy, energy-dispersive X-ray and FT-IR methods were used to characterize the product. Photocatalytic efficiency of the prepared catalyst for degradation of 2,4-DCP was tested under illumination of UV-A and visible light. The results obtained reveal that the photocatalyst is very active in degradation of 2,4-DCP. The photodegradation process is completed within 3 h using a dose of 0.6 g/L of the catalyst under UV irradiation. The reactions follow a pseudo-first-order kinetics and the observed rate constant values change with 2,4-DCP concentrations. The reproducibility of the catalyst was tested. The reaction intermediates were identified by gas chromatoghraphy-mass spectrometery (GC-MS) technique.

Direct observation of hindered eccentric rotation of an individual molecule : Cu-phthalocyanine on C60

NARCIS (Netherlands)

Stöhr, Meike; Wagner, T; Gabriel, M; Weyers, B; Moller, R

2002-01-01

Individual Cu-phthalocyanine molecules have been investigated by scanning tunnel microscopy on a closed packed film of C-60 at various temperatures. The molecules are found to bind asymmetrically to one C-60. While they remain in one position at low temperature, they can hop between six equivalent

Energy-level alignment at interfaces between manganese phthalocyanine and C60

Directory of Open Access Journals (Sweden)

Daniel Waas

2017-04-01

Full Text Available We have used photoelectron spectroscopy to determine the energy-level alignment at organic heterojunctions made of manganese phthalocyanine (MnPc and the fullerene C60. We show that this energy-level alignment depends upon the preparation sequence, which is explained by different molecular orientations. Moreover, our results demonstrate that MnPc/C60 interfaces are hardly suited for application in organic photovoltaic devices, since the energy difference of the two lowest unoccupied molecular orbitals (LUMOs is rather small.

Phthalocyanine-nanocarbon ensembles: From discrete molecular and supramolecular systems to hybrid nanomaterials

OpenAIRE

Bottari, Giovanni; De La Torre, Gema; Torres, Tomas

2015-01-01

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Accounts of Chemical Research, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/ar5004384 Conspectus Phthalocyanines (Pcs) are macrocyclic and aromatic compounds that present unique electronic features such as high molar absorption coefficients, rich redox chemistry, and...

Interaction of selected gases with zinc phthalocyanine thin films: theoretical and experimental studies

Czech Academy of Sciences Publication Activity Database

Šebera, Jakub; Fitl, P.; Vlček, J.; Vrňata, M.; Fendrych, František; Kopeček, Jaromír; Kratochvílová, Irena

2013-01-01

Roč. 64, č. 1 (2013), "10202-p1"-"10202-p6" ISSN 1286-0042 R&D Projects: GA TA ČR TA01011165; GA ČR(CZ) GAP304/10/1951; GA ČR(CZ) GAP108/11/1298 Institutional support: RVO:68378271 Keywords : Zinc phthalocyanine * charge transport * sensor * DFT Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.789, year: 2013

Las Organizaciones de la Sociedad Civil (OSC) y la agenda internacional del desarrollo: escenario latinoamericano

OpenAIRE

Revilla Blanco, María Luisa

2012-01-01

En este artículo se analiza la acción de las organizaciones de la sociedad civil latinoamericanas: su evolución y el papel que juegan en la definición de la agenda internacional del desarrollo desde América Latina. Para ello, me detendré en los siguientes puntos: 1. Los hitos más importantes en la generación de consensos sobre los contenidos de esa agenda de desarrollo en lo que va de siglo y el reconocimiento del papel de las OSC. 2. La situación de América Latina en este contexto. ...

Electronic transport properties of (fluorinated) metal phthalocyanine

KAUST Repository

Fadlallah, M M; Eckern, U; Romero, A H; Schwingenschlö gl, Udo

2015-01-01

The magnetic and transport properties of the metal phthalocyanine (MPc) and F16MPc (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ag) families of molecules in contact with S–Au wires are investigated by density functional theory within the local density approximation, including local electronic correlations on the central metal atom. The magnetic moments are found to be considerably modified under fluorination. In addition, they do not depend exclusively on the configuration of the outer electronic shell of the central metal atom (as in isolated MPc and F16MPc) but also on the interaction with the leads. Good agreement between the calculated conductance and experimental results is obtained. For M = Ag, a high spin filter efficiency and conductance is observed, giving rise to a potentially high sensitivity for chemical sensor applications.

Electronic transport properties of (fluorinated) metal phthalocyanine

KAUST Repository

Fadlallah, M M

2015-12-21

The magnetic and transport properties of the metal phthalocyanine (MPc) and F16MPc (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ag) families of molecules in contact with S–Au wires are investigated by density functional theory within the local density approximation, including local electronic correlations on the central metal atom. The magnetic moments are found to be considerably modified under fluorination. In addition, they do not depend exclusively on the configuration of the outer electronic shell of the central metal atom (as in isolated MPc and F16MPc) but also on the interaction with the leads. Good agreement between the calculated conductance and experimental results is obtained. For M = Ag, a high spin filter efficiency and conductance is observed, giving rise to a potentially high sensitivity for chemical sensor applications.

Optical limiting properties of optically active phthalocyanine derivatives

Science.gov (United States)

Wang, Peng; Zhang, Shuang; Wu, Peiji; Ye, Cheng; Liu, Hongwei; Xi, Fu

2001-06-01

The optical limiting properties of four optically active phthalocyanine derivatives in chloroform solutions and epoxy resin thin plates were measured at 532 nm with 10 ns pulses. The excited state absorption cross-section σex and refractive-index cross-section σr were determined with the Z-scan technique. These chromophores possess larger σex than the ground state absorption cross-section σ0, indicating that they are the potential materials for reverse saturable absorption (RSA). The negative σr values of these chromophores add to the thermal contribution, producing a larger defocusing effect, which may be helpful in further enhancing their optical limiting performance. The optical limiting responses of the thin plate samples are stronger than those of the chloroform solutions.

Copper and Copper Proteins in Parkinson's Disease

Science.gov (United States)

Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

2014-01-01

Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology. PMID:24672633

Evaluation of antibacterial properties of novel phthalocyanines against Escherichia coli - comparison of analytical methods

Czech Academy of Sciences Publication Activity Database

Mikula, Přemysl; Kalhotka, L.; Jančula, Daniel; Zezulka, Štěpán; Kořínková, R.; Černý, J.; Maršálek, Blahoslav; Toman, Petr

2014-01-01

Roč. 138, Sep 2014 (2014), s. 230-239 ISSN 1011-1344 R&D Projects: GA TA ČR TA01010356; GA MPO FR-TI3/196; GA ČR(CZ) GAP205/10/2280 Institutional support: RVO:67985939 ; RVO:61389013 Keywords : phthalocyanine s * photosensitizers * antibacterial effect Subject RIV: EF - Botanics; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 2.960, year: 2014

Flexible heterostructures based on metal phthalocyanines thin films obtained by MAPLE

International Nuclear Information System (INIS)

Socol, M.; Preda, N.; Rasoga, O.; Breazu, C.; Stavarache, I.; Stanculescu, F.; Socol, G.; Gherendi, F.; Grumezescu, V.; Popescu-Pelin, G.; Girtan, M.; Stefan, N.

2016-01-01

Highlights: • Organic heterostructures prepared by MAPLE having a large absorbtion domain. • Photogeneration process is evidenced in the structure with ZnPc:TPyP mixed layer. • An increase in current value is observed in the structure with MgPc:TPyP mixed layer. - Abstract: Heterostructures based on zinc phthalocyanine (ZnPc), magnesium phthalocyanine (MgPc) and 5,10,15,20-tetra(4-pyrydil)21H,23H-porphine (TPyP) were deposited on ITO flexible substrates by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. Organic heterostructures containing (TPyP/ZnPc(MgPc)) stacked or (ZnPc(MgPc):TPyP) mixed layers were characterized by X-ray diffraction-XRD, photoluminescence-PL, UV–vis and FTIR spectroscopy. No chemical decomposition of the initial materials was observed. The investigated structures present a large spectral absorption in the visible range making them suitable for organic photovoltaics applications (OPV). Scanning electron microscopy-SEM and atomic force microscopy-AFM revealed morphologies typical for the films prepared by MAPLE. The current–voltage characteristics of the investigated structures, measured in dark and under light, present an improvement in the current value (∼3 order of magnitude larger) for the structure based on the mixed layer (Al/MgPc:TPyP/ITO) in comparison with the stacked layer (Al/MgPc//TPyP/ITO). A photogeneration process was evidenced in the case of structures Al/ZnPc:TPyP/ITO with mixed layers.

Flexible heterostructures based on metal phthalocyanines thin films obtained by MAPLE

Energy Technology Data Exchange (ETDEWEB)

Socol, M., E-mail: cela@infim.ro [National Institute of Material Physics, 105 bis Atomistilor Street, PO Box MG-7, 077125 Bucharest-Magurele (Romania); Preda, N.; Rasoga, O. [National Institute of Material Physics, 105 bis Atomistilor Street, PO Box MG-7, 077125 Bucharest-Magurele (Romania); Breazu, C. [National Institute of Material Physics, 105 bis Atomistilor Street, PO Box MG-7, 077125 Bucharest-Magurele (Romania); University of Bucharest, Faculty of Physics, 405 Atomistilor Street, PO Box MG-11, 077125 Bucharest-Magurele (Romania); Stavarache, I. [National Institute of Material Physics, 105 bis Atomistilor Street, PO Box MG-7, 077125 Bucharest-Magurele (Romania); Stanculescu, F. [University of Bucharest, Faculty of Physics, 405 Atomistilor Street, PO Box MG-11, 077125 Bucharest-Magurele (Romania); Socol, G.; Gherendi, F.; Grumezescu, V.; Popescu-Pelin, G. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-36, 077125 Bucharest-Magurele (Romania); Girtan, M. [Laboratoire de Photonique d’Angers, Université d’Angers, 2, Bd. Lavoisier, 49045 Angers (France); Stefan, N. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-36, 077125 Bucharest-Magurele (Romania)

2016-06-30

Highlights: • Organic heterostructures prepared by MAPLE having a large absorbtion domain. • Photogeneration process is evidenced in the structure with ZnPc:TPyP mixed layer. • An increase in current value is observed in the structure with MgPc:TPyP mixed layer. - Abstract: Heterostructures based on zinc phthalocyanine (ZnPc), magnesium phthalocyanine (MgPc) and 5,10,15,20-tetra(4-pyrydil)21H,23H-porphine (TPyP) were deposited on ITO flexible substrates by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. Organic heterostructures containing (TPyP/ZnPc(MgPc)) stacked or (ZnPc(MgPc):TPyP) mixed layers were characterized by X-ray diffraction-XRD, photoluminescence-PL, UV–vis and FTIR spectroscopy. No chemical decomposition of the initial materials was observed. The investigated structures present a large spectral absorption in the visible range making them suitable for organic photovoltaics applications (OPV). Scanning electron microscopy-SEM and atomic force microscopy-AFM revealed morphologies typical for the films prepared by MAPLE. The current–voltage characteristics of the investigated structures, measured in dark and under light, present an improvement in the current value (∼3 order of magnitude larger) for the structure based on the mixed layer (Al/MgPc:TPyP/ITO) in comparison with the stacked layer (Al/MgPc//TPyP/ITO). A photogeneration process was evidenced in the case of structures Al/ZnPc:TPyP/ITO with mixed layers.

Physical and photophysical properties of mixed double- and triple-decker sandwiches of porphyrins and phthalocyanines

International Nuclear Information System (INIS)

Salabert, Isabelle

1995-01-01

The study of electron transfer and charge recombination processes in various oligomers of porphyrins and phthalocyanines is reported. Our objective is to determine the nature of processes which compete with electron transfer in such Systems. The first part of this thesis is devoted to the study of mixed double- and triple-decker sandwich compounds of porphyrins and phthalocyanines of cerium and praseodymium. The charge transfer reaction and geminated recombination from excited complexes in solution and in sublimated film are investigated by time-resolved absorption spectroscopy with femtosecond time scale resolution. These results show the influence of the magnetic nature of the metal ion and of the relative position of the chromophores in the complex on the photophysical processes. The physical and photophysical properties of complexes formed by pairing in solution porphyrins and porphyrazines bearing oppositely charged substituent are reported in the second part. The formation of mixed aggregates of high order (2 to 5) is observed and their nature are spectrally characterized. The photoproducts issued from these complexes are extremely stable. (author) [fr

An effective zinc phthalocyanine derivative for photodynamic antimicrobial chemotherapy

International Nuclear Information System (INIS)

Chen, Zhuo; Zhou, Shanyong; Chen, Jincan; Li, Linsen; Hu, Ping; Chen, Song; Huang, Mingdong

2014-01-01

Bacterial infection is a common clinical problem. The emergence of antibiotic resistant bacteria posts a severe challenge to medical practice worldwide. Photodynamic antimicrobial chemotherapy (PACT) uses laser light at specific wavelength to activate oxygen molecule in the human tissue into reactive oxygen species as antimicrobial agent. This activation of oxygen by laser light is mediated through a photosensitizer. Two key properties for potent photosensitizer are its absorbance of light in the infrared region (630–700 nm), which promotes tissue penetration depth, and the selective accumulation on bacteria instead of human tissue. We herein report a zinc phthalocyanine derivative, pentalysine β-carbonylphthalocyanine zinc (ZnPc-(Lys) 5 ) and its antimicrobial effects in vitro and in an animal infection model. This photosensitizer has strong capability to kill bacteria at 670 nm. Chemically, it is a water-soluble and cationic photosensitizer carrying positive charge under physiological pH, and can specifically target to bacteria which usually bears negative charges on its surface. Compared with anionic ZnPc counterparts, ZnPc-(Lys) 5 shows a higher phototoxicity toward bacteria. PACT studies of ZnPc-(Lys) 5 in experimental infection animal model showed a significant bacteria inhibition compared to controls, and high selectivity of ZnPc-(Lys) 5 toward bacteria. These findings suggest ZnPc-(Lys) 5 is a promising antimicrobial photosensitizer for the treatment of infectious diseases. - Highlights: • Photodynamic antimicrobial chemotherapy (PACT) with water-soluble zinc phthalocyanine derivative offers a promising measure to deal with antibiotic resistance of bacteria. • The use of portable LED light sources that are battery-powered and with low cost may make possible the deployment of systems that can be used for wound decontamination. • ZnPc-(Lys) 5 is a potent photosensitizer for treatment of infectious diseases

An effective zinc phthalocyanine derivative for photodynamic antimicrobial chemotherapy

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhuo, E-mail: zchen@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry and Danish-Chinese Centre for Proteases and Cancer, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Zhou, Shanyong; Chen, Jincan [State Key Laboratory of Structural Chemistry and Danish-Chinese Centre for Proteases and Cancer, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Li, Linsen [Department of Biochemistry, Shenyang Medical College, Shenyang, Liaoning 110034 (China); Hu, Ping; Chen, Song [State Key Laboratory of Structural Chemistry and Danish-Chinese Centre for Proteases and Cancer, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Huang, Mingdong, E-mail: mhuang@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry and Danish-Chinese Centre for Proteases and Cancer, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2014-08-01

Bacterial infection is a common clinical problem. The emergence of antibiotic resistant bacteria posts a severe challenge to medical practice worldwide. Photodynamic antimicrobial chemotherapy (PACT) uses laser light at specific wavelength to activate oxygen molecule in the human tissue into reactive oxygen species as antimicrobial agent. This activation of oxygen by laser light is mediated through a photosensitizer. Two key properties for potent photosensitizer are its absorbance of light in the infrared region (630–700 nm), which promotes tissue penetration depth, and the selective accumulation on bacteria instead of human tissue. We herein report a zinc phthalocyanine derivative, pentalysine β-carbonylphthalocyanine zinc (ZnPc-(Lys){sub 5}) and its antimicrobial effects in vitro and in an animal infection model. This photosensitizer has strong capability to kill bacteria at 670 nm. Chemically, it is a water-soluble and cationic photosensitizer carrying positive charge under physiological pH, and can specifically target to bacteria which usually bears negative charges on its surface. Compared with anionic ZnPc counterparts, ZnPc-(Lys){sub 5} shows a higher phototoxicity toward bacteria. PACT studies of ZnPc-(Lys){sub 5} in experimental infection animal model showed a significant bacteria inhibition compared to controls, and high selectivity of ZnPc-(Lys){sub 5} toward bacteria. These findings suggest ZnPc-(Lys){sub 5} is a promising antimicrobial photosensitizer for the treatment of infectious diseases. - Highlights: • Photodynamic antimicrobial chemotherapy (PACT) with water-soluble zinc phthalocyanine derivative offers a promising measure to deal with antibiotic resistance of bacteria. • The use of portable LED light sources that are battery-powered and with low cost may make possible the deployment of systems that can be used for wound decontamination. • ZnPc-(Lys){sub 5} is a potent photosensitizer for treatment of infectious diseases.

Absorption Spectroscopy, Molecular Dynamics Calculations, and Multivariate Curve Resolution on the Phthalocyanine Aggregation

Energy Technology Data Exchange (ETDEWEB)

Ajloo, Davood; Ghadamgahi, Maryam; Shaheri, Freshte; Zarei, Kobra [Damghan Univ., Damghan (Iran, Islamic Republic of)

2014-05-15

Co(II)-tetrasulfonated phthalocyanine (CoTSP) is known to be aggregated to dimer at high concentration levels in water. A study on the aggregation of CoTSP using multivariate curve resolution analysis of the visible absorbance spectra over a concentration range of 30, 40 and 50 μM in the presence of dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), acetonitrile (AN) and ethanol (EtOH) in the concentration range of 0 to 3.57 M is conducted. A hard modeling-based multivariate curve resolution method was applied to determine the dissociation constants of the CoTSP aggregates at various temperatures ranging from 25, 45 and 65 .deg. C and in the presence of various co-solvents. Dissociation constant for aggregation was increased and then decrease by temperature and concentration of phthalocyanine, respectively. Utilizing the vant Hoff relation, the enthalpy and entropy of the dissociation equilibriums were calculated. For the dissociation of both aggregates, the enthalpy and entropy changes were positive and negative, respectively. Molecular dynamics simulation of cosolvent effect on CoTSP aggregation was done to confirm spectroscopy results. Results of radial distribution function (RDF), root mean square deviation (RMSD) and distance curves confirmed more effect of polar solvent to decrease monomer formation.

Absorption Spectroscopy, Molecular Dynamics Calculations, and Multivariate Curve Resolution on the Phthalocyanine Aggregation

International Nuclear Information System (INIS)

Ajloo, Davood; Ghadamgahi, Maryam; Shaheri, Freshte; Zarei, Kobra

2014-01-01

Co(II)-tetrasulfonated phthalocyanine (CoTSP) is known to be aggregated to dimer at high concentration levels in water. A study on the aggregation of CoTSP using multivariate curve resolution analysis of the visible absorbance spectra over a concentration range of 30, 40 and 50 μM in the presence of dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), acetonitrile (AN) and ethanol (EtOH) in the concentration range of 0 to 3.57 M is conducted. A hard modeling-based multivariate curve resolution method was applied to determine the dissociation constants of the CoTSP aggregates at various temperatures ranging from 25, 45 and 65 .deg. C and in the presence of various co-solvents. Dissociation constant for aggregation was increased and then decrease by temperature and concentration of phthalocyanine, respectively. Utilizing the vant Hoff relation, the enthalpy and entropy of the dissociation equilibriums were calculated. For the dissociation of both aggregates, the enthalpy and entropy changes were positive and negative, respectively. Molecular dynamics simulation of cosolvent effect on CoTSP aggregation was done to confirm spectroscopy results. Results of radial distribution function (RDF), root mean square deviation (RMSD) and distance curves confirmed more effect of polar solvent to decrease monomer formation

Capacitance measurements and AC conductivity of Nickel Phthalocyanine films

International Nuclear Information System (INIS)

Darwish, S.

2005-01-01

A C dark Current measurements of nickel phthalocyanine thin films using ohmic gold electrodes are investigated in the frequency range 30-10 Hz and within the temperature range 295-385 K. The A C conductivity as D Ac is found to vary as within the index s < 1, indicating a dominant hopping process at low temperatures. From the temperature dependence of A C conductivity, free carrier conduction with mean activation energy of 0.31 eV is observed at higher temperatures. Capacitance and loss tangent are found to be decreased with increasing frequency and increase with increasing temperature. Such characteristics are found to be in good qualitative agreement with existing equivalent circuit model assuming ohmic contacts

Assessing third-year medical students' ability to address a patient's spiritual distress using an OSCE case.

Science.gov (United States)

McEvoy, Mimi; Schlair, Sheira; Sidlo, Zsuzsanna; Burton, William; Milan, Felise

2014-01-01

To inform curricular development by assessing the ability of third-year medical students to address a patient's spiritual distress during an acute medical crisis in the context of an objective structured clinical examination (OSCE) case. During March and April 2010, 170 third-year medical students completed an eight-station videotaped OSCE at Albert Einstein College of Medicine of Yeshiva University. One of the standardized patients (SPs) was a 65-year-old man with acute chest pain who mentioned his religious affiliation and fear of dying. If prompted, he revealed his desire to speak with a chaplain. The SP assessed students' history taking, physical examination, and communication skills. In a postencounter written exercise, students reported their responses to the patient's distress via four open-ended questions. Analysis of the postencounter notes was conducted by three coders for emergent themes. Clinical skills performance was compared between students who reported making chaplain referral and those who did not. A total of 108 students (64%) reported making a chaplain referral; 4 (2%) directly addressed the patient's religious/spiritual beliefs. Students' clinical performance scores showed no significant association with whether they made a chaplain referral. Findings suggest that the majority of medical students without robust training in addressing patients' spiritual needs can make a chaplain referral when faced with a patient in spiritual crisis. Yet, few students explicitly engaged the patient in a discussion of his beliefs. Thus, future studies are needed to develop more precise assessment measures that can inform development in spirituality and medicine curricula.

Novel Topical Photodynamic Therapy of Prostate Carcinoma Using Hydroxy-aluminum Phthalocyanine Entrapped in Liposomes

Czech Academy of Sciences Publication Activity Database

Sutoris, K.; Rakušan, J.; Karásková, M.; Mattová, J.; Beneš, J.; Nekvasil, Miloš; Ježek, Petr; Zadinová, M.; Poučková, P.; Větvička, D.

2013-01-01

Roč. 33, č. 4 (2013), s. 1563-1568 ISSN 0250-7005 R&D Projects: GA MPO(CZ) 2A-1TP1/026; GA MŠk(CZ) OE09026; GA TA ČR(CZ) TA01010781 Institutional support: RVO:67985823 Keywords : PC prostate carcinomas * LNCaP * liposomes * hydroxy-aluminum phthalocyanine * photodynamic therapy Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 1.872, year: 2013

Copper and copper-nickel alloys as zebra mussel antifoulants

Energy Technology Data Exchange (ETDEWEB)

Dormon, J.M.; Cottrell, C.M.; Allen, D.G.; Ackerman, J.D.; Spelt, J.K. [Univ. of Toronto, Ontario (Canada)

1996-04-01

Copper has been used in the marine environment for decades as cladding on ships and pipes to prevent biofouling by marine mussels (Mytilus edulis L.). This motivated the present investigation into the possibility of using copper to prevent biofouling in freshwater by both zebra mussels and quagga mussels (Dreissena polymorpha and D. bugensis collectively referred to as zebra mussels). Copper and copper alloy sheet proved to be highly effective in preventing biofouling by zebra mussels over a three-year period. Further studies were conducted with copper and copper-nickel mesh (lattice of expanded metal) and screen (woven wire with a smaller hole size), which reduced the amount of copper used. Copper screen was also found to be strongly biofouling-resistant with respect to zebra mussels, while copper mesh reduced zebra mussel biofouling in comparison to controls, but did not prevent it entirely. Preliminary investigations into the mechanism of copper antifouling, using galvanic couples, indicated that the release of copper ions from the surface of the exposed metal into the surrounding water is directly or indirectly responsible for the biofouling resistance of copper.

Simultaneous Reduction of CO 2 and Splitting of H 2 O by a Single Immobilized Cobalt Phthalocyanine Electrocatalyst

KAUST Repository

Morlanes, Natalia Sanchez; Takanabe, Kazuhiro; Rodionov, Valentin

2016-01-01

Perfluorinated cobalt phthalocyanine (CoFPc) immobilized on carbon electrodes was found to electrocatalyze the reduction of CO2 selectively to CO in an aqueous solution. The conversion of CO2 became apparent at -0.5 V vs RHE, and the Faradaic

Phthalocyanine-loaded graphene nanoplatform for imaging-guided combinatorial phototherapy

Directory of Open Access Journals (Sweden)

Taratula O

2015-03-01

Full Text Available Olena Taratula,1 Mehulkumar Patel,2 Canan Schumann,1 Michael A Naleway,1 Addison J Pang,1 Huixin He,2 Oleh Taratula1 1Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA; 2Department of Chemistry, Rutgers University-Newark, Newark, NJ, USA Abstract: We report a novel cancer-targeted nanomedicine platform for imaging and prospect for future treatment of unresected ovarian cancer tumors by intraoperative multimodal phototherapy. To develop the required theranostic system, novel low-oxygen graphene nanosheets were chemically modified with polypropylenimine dendrimers loaded with phthalocyanine (Pc as a photosensitizer. Such a molecular design prevents fluorescence quenching of the Pc by graphene nanosheets, providing the possibility of fluorescence imaging. Furthermore, the developed nanoplatform was conjugated with poly(ethylene glycol, to improve biocompatibility, and with luteinizing hormone-releasing hormone (LHRH peptide, for tumor-targeted delivery. Notably, a low-power near-infrared (NIR irradiation of single wavelength was used for both heat generation by the graphene nanosheets (photothermal therapy [PTT] and for reactive oxygen species (ROS-production by Pc (photodynamic therapy [PDT]. The combinatorial phototherapy resulted in an enhanced destruction of ovarian cancer cells, with a killing efficacy of 90%–95% at low Pc and low-oxygen graphene dosages, presumably conferring cytotoxicity to the synergistic effects of generated ROS and mild hyperthermia. An animal study confirmed that Pc loaded into the nanoplatform can be employed as a NIR fluorescence agent for imaging-guided drug delivery. Hence, the newly developed Pc-graphene nanoplatform has the significant potential as an effective NIR theranostic probe for imaging and combinatorial phototherapy. Keywords: graphene nanosheets, phthalocyanine, photothermal therapy, photodynamic therapy, theranostic 

GPU-accelerated few-view CT reconstruction using the OSC and TV techniques

Energy Technology Data Exchange (ETDEWEB)

Matenine, Dmitri [Montreal Univ., QC (Canada). Dept. de Physique; Hissoiny, Sami [Ecole Polytechnique de Montreal, QC (Canada). Dept. de Genie Informatique et Genie Logiciel; Despres, Philippe [Centre Hospitalier Univ. de Quebec, QC (Canada). Dept. de Radio-Oncologie

2011-07-01

The present work proposes a promising iterative reconstruction technique designed specifically for X-ray transmission computed tomography (CT). The main objective is to reduce diagnostic radiation dose through the reduction of the number of CT projections, while preserving image quality. The second objective is to provide a fast implementation compatible with clinical activities. The proposed tomographic reconstruction technique is a combination of the Ordered Subsets Convex (OSC) algorithm and the Total Variation minimization (TV) regularization technique. The results in terms of image quality and computational speed are discussed. Using this technique, it was possible to obtain reconstructed slices of relatively good quality with as few as 100 projections, leading to potential dose reduction factors of up to an order of magnitude depending on the application. The algorithm was implemented on a Graphical Processing Unit (GPU) and yielded reconstruction times of approximately 185 ms per slice. (orig.)

Enhanced fluorescence of tetrasulfonated zinc phthalocyanine by graphene quantum dots and its application in molecular sensing/imaging.

Science.gov (United States)

Wang, Jian; Zhang, Yanjun; Ye, Jiqing; Jiang, Zhou

2017-06-01

When excited at 435 nm, tetra-sulfonate zinc phthalocyanine (ZnPcS 4 ) emitted dual fluorescence at 495 and 702 nm. The abnormal fluorescence at 495 nm was experimentally studied and analyzed in detail for the first time. The abnormal fluorescence at 495 nm was deduced to originate from triplet-triplet (T-T) energy transfer of excited phthalocyanine ( 3 *ZnPcS 4 ). Furthermore, graphene quantum dots (GQDs) enhanced the 495 nm fluorescence quantum yield (Q) of ZnPcS 4 . The fluorescence properties of ZnPcS 4 -GQDs conjugate were retained in a cellular environment. Based on the fluorescence of ZnPcS 4 -GQDs conjugate, we designed and prepared an Apt29/thrombin/Apt15 sandwich thrombin sensor with high specificity and affinity. This cost-saving, simple operational sensing strategy can be extended to use in sensing/imaging of other biomolecules. Copyright © 2016 John Wiley & Sons, Ltd.

Copper and Copper Proteins in Parkinson’s Disease

Directory of Open Access Journals (Sweden)

Sergio Montes

2014-01-01

Full Text Available Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson’s disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson’s disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson’s disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson’s disease and that a mutation in ATP7B could be associated with Parkinson’s disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.

Photoconductivity study of acid on Zinc phthalocyanine pyridine thin films

Energy Technology Data Exchange (ETDEWEB)

Singh, Sukhwinder, E-mail: ss7667@gmail.com [Department of Physics, Govt. College for Girls, Ludhiana (India); Saini, G. S. S.; Tripathi, S. K. [Department of Physics, Panjab University, Chandigarh (India)

2016-05-06

The Metal Phthalocyanine (MPc) have attracted much interest because of chemical and high thermal stability. Molecules forming a crystal of MPc are held together by weak attractive Vander Waals forces. Organic semiconductors have π conjugate bonds which allow electrons to move via π-electron cloud overlaps. Conduction mechanisms for organic semiconductor are mainly through tunneling; hopping between localized states, mobility gaps, and phonon assisted hopping. The photo conductivity of thin films of these complexes changes when exposed to oxidizing and reducing gases. Arrhenius plot is used to find the thermal activation energy in the intrinsic region and impurity scattering region. Arrhenius plotsare used to find the thermal activation energy.

Study of charge transfer processes in porphyrins- and phthalocyanins-based materials: from the liquid phase to the solid state

International Nuclear Information System (INIS)

Fournier, Thierry

1994-01-01

In order to efficiently conceive and build supramolecular materials for molecular electronics and optoelectronics, one need to have access to a large data base on the interactions between the elementary pieces of the material. Such a data base can be established only through the study of model Systems and model media. Oligomers of porphyrins and phthalocyanines constitute models of choice: due to the chemical versatility of the compounds, their physical and photophysical properties can be adjusted to produce a targeted function. The first part of this thesis is concerned with double- and triple-Decker mixed porphyrin and Phthalocyanines sandwich compounds of cerium. Then we study the photophysical properties of complexes formed by pairing in solution porphyrins and phthalocyanines bearing oppositely charged substituents. The charge transfer reactions and geminated recombinations are investigated by time-resolved absorption spectroscopy (from the femto- to millisecond time scales) for excited complexes either in solution, or confined in sol-gel matrices or in Langmuir-Blodgett films. The results obtained in the various media are compared and analysed by the Marcus theory. They allow to show that, for strongly coupled complexes, the solvent does not play any key role in the forward and backward electron transfer. We conclude this work by introducing a few targeted projects based on of the photophysical properties of these complexes, namely photodynamic therapy of cancers, nonlinear optics and the generation of photovoltage. (author) [fr

Copper carrier protein in copper toxic sheep liver

Energy Technology Data Exchange (ETDEWEB)

Harris, A L; Dean, P D.G.

1973-01-01

The livers of copper-toxic sheep have been analyzed by gel electrophoresis followed by staining the gels for copper with diethyldithiocarbamate and for protein with amido schwartz. These gels were compared with similar gels obtained from the livers of normal and copper-deficient animals. The copper-toxic livers contained an extra protein band which possessed relatively weakly bound copper. Possible origins of this protein are discussed. 8 references, 1 figure, 2 tables.

Assessing the potential of group 13 and 14 metal/metalloid phthalocyanines as hole transport layers in organic light emitting diodes

Science.gov (United States)

Plint, Trevor; Lessard, Benoît H.; Bender, Timothy P.

2016-04-01

In this study, we have assessed the potential application of group 13 and 14 metal and metalloid phthalocyanines ((X)n-MPcs) and their axially substituted derivatives as hole-transporting layers in organic light emitting diodes (OLEDs). OLEDs studied herein have the generic structure of glass/ITO/(N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) or (X)n-MPc)(50 nm)/Alq3 (60 nm)/LiF (1 nm)/Al (80 nm), where X is an axial substituent group. OLEDs using chloro aluminum phthalocyanine (Cl-AlPc) showed good peak luminance values of 2620 ± 113 cd/m2 at 11 V. To our knowledge, Cl-AlPc has not previously been shown to work as a hole transport material (HTL) in OLEDs. Conversely, the di-chlorides of silicon, germanium, and tin phthalocyanine (Cl2-SiPc, Cl2-GePc, and Cl2-SnPc, respectively) showed poor performance compared to Cl-AlPc, having peak luminances of only 38 ± 4 cd/m2 (12 V), 23 ± 1 cd/m2 (8.5 V), and 59 ± 5 cd/m2 (13.5 V), respectively. However, by performing a simple axial substitution of the chloride groups of Cl2-SiPc with pentafluorophenoxy groups, the resulting bis(pentafluorophenoxy) silicon phthalocyanine (F10-SiPc) containing OLED had a peak luminance of 5141 ± 941 cd/m2 (10 V), a two order of magnitude increase over its chlorinated precursor. This material showed OLED characteristics approaching those of a baseline OLED based on the well-studied triarylamine NPB. Attempts to attach the pentafluorophenoxy axial group to both SnPc and GePc were hindered by synthetic difficulties and low thermal stability, respectively. In light of the performance improvements observed by simple axial substitution of SiPc in OLEDs, the use of axially substituted MPcs in organic electronic devices remains of continuing interest to us and potentially the field in general.

Inversed linear dichroism in F K-edge NEXAFS spectra of fluorinated planar aromatic molecules

DEFF Research Database (Denmark)

de Oteyza, D. G.; Sakko, A.; El-Sayed, A.

2012-01-01

The symmetry and energy distribution of unoccupied molecular orbitals is addressed in this work by means of NEXAFS and density functional theory calculations for planar, fluorinated organic semiconductors (perfluorinated copper phthalocyanines and perfluoropentacene). We demonstrate how molecular...

The iOSC3 System: Using Ontologies and SWRL Rules for Intelligent Supervision and Care of Patients with Acute Cardiac Disorders

Directory of Open Access Journals (Sweden)

Marcos Martínez-Romero

2013-01-01

Full Text Available Physicians in the Intensive Care Unit (ICU are specially trained to deal constantly with very large and complex quantities of clinical data and make quick decisions as they face complications. However, the amount of information generated and the way the data are presented may overload the cognitive skills of even experienced professionals and lead to inaccurate or erroneous actions that put patients’ lives at risk. In this paper, we present the design, development, and validation of iOSC3, an ontology-based system for intelligent supervision and treatment of critical patients with acute cardiac disorders. The system analyzes the patient’s condition and provides a recommendation about the treatment that should be administered to achieve the fastest possible recovery. If the recommendation is accepted by the doctor, the system automatically modifies the quantity of drugs that are being delivered to the patient. The knowledge base is constituted by an OWL ontology and a set of SWRL rules that represent the expert’s knowledge. iOSC3 has been developed in collaboration with experts from the Cardiac Intensive Care Unit (CICU of the Meixoeiro Hospital, one of the most significant hospitals in the northwest region of Spain.

Characterization of Langmuir and Langmuir–Blodgett films of an octasubstituted zinc phthalocyanine

International Nuclear Information System (INIS)

Torrent-Burgués, J.; Cea, P.; Giner, I.; Guaus, E.

2014-01-01

In this work we report the fabrication of Langmuir and Langmuir–Blodgett (LB) films of a substituted ZnPc (octakis(oxyoctyl)phthalocyanine of zinc), and their characterization by means of several techniques. These characterization techniques include surface pressure (π-A) and surface potential (ΔV-A) isotherms as well as UV–vis Reflection spectroscopy and Brewster Angle Microscopy (BAM) for the films at the air–water interface together with UV–vis absorption and IR spectroscopies and Atomic Force Microscopy (AFM) for the LB films. The π-A and ΔV-A isotherms and BAM images indicate a phase transition at a surface pressure of ca. 9 mN/m and a multilayer formation at surface pressures around 19–20 mN/m; at a surface pressure around 27 mN/m a disordered collapse of the film occurs. In addition, AFM images of LB films at π = 10 mN/m and π = 20 mN/m show a monomolecular and a multilayered film, respectively. The comparison of the UV–vis spectrum of ZnPc in solution, the reflection spectra of the Langmuir films and UV–vis spectra of LB films reveals a significant reduction in the Q band intensity for the films, indicative of an organization of ZnPc in the Langmuir and LB films versus the random distribution in solution. The UV–vis Reflection spectra are also consistent with multilayer formation at surface pressures around 19–20 mN/m. The relative intensities of the IR spectrum bands change from the KBr pellet to the LB film which is also attributable to orientation effects in the film. Cyclic voltammetric experiments of LB films incorporating the ZnPc derivative show peaks that can be correlated with redox processes occurring in the phthalocyanine ring. A small but significant influence of the surface pressure and the number of deposited layers in the electrochemical behaviour is observed. The electrochemical response of cast films exhibits some differences with respect to that of LB films which have been attributed to their different molecular

Characterization of Langmuir and Langmuir–Blodgett films of an octasubstituted zinc phthalocyanine

Energy Technology Data Exchange (ETDEWEB)

Torrent-Burgués, J. [Department of Chemical Engineering, Universitat Politècnica de Catalunya (UPC), C/Colom 1, 08222 Terrassa, Barcelona (Spain); Institut de Bioenginyeria de Catalunya (IBEC), 08028 Barcelona (Spain); Cea, P. [Departamento de Química Orgánica y Química Física, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain); Instituto de Nanociencia de Aragón (INA) y Laboratorio de Microscopias Avanzadas (LMA), Edificio i+d, Campus Rio Ebro, Universidad de Zaragoza, C/Mariano Esquillor, s/n, 50017 Zaragoza (Spain); Giner, I. [Departamento de Química Orgánica y Química Física, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain); Guaus, E. [Department of Chemical Engineering, Universitat Politècnica de Catalunya (UPC), C/Colom 1, 08222 Terrassa, Barcelona (Spain)

2014-04-01

In this work we report the fabrication of Langmuir and Langmuir–Blodgett (LB) films of a substituted ZnPc (octakis(oxyoctyl)phthalocyanine of zinc), and their characterization by means of several techniques. These characterization techniques include surface pressure (π-A) and surface potential (ΔV-A) isotherms as well as UV–vis Reflection spectroscopy and Brewster Angle Microscopy (BAM) for the films at the air–water interface together with UV–vis absorption and IR spectroscopies and Atomic Force Microscopy (AFM) for the LB films. The π-A and ΔV-A isotherms and BAM images indicate a phase transition at a surface pressure of ca. 9 mN/m and a multilayer formation at surface pressures around 19–20 mN/m; at a surface pressure around 27 mN/m a disordered collapse of the film occurs. In addition, AFM images of LB films at π = 10 mN/m and π = 20 mN/m show a monomolecular and a multilayered film, respectively. The comparison of the UV–vis spectrum of ZnPc in solution, the reflection spectra of the Langmuir films and UV–vis spectra of LB films reveals a significant reduction in the Q band intensity for the films, indicative of an organization of ZnPc in the Langmuir and LB films versus the random distribution in solution. The UV–vis Reflection spectra are also consistent with multilayer formation at surface pressures around 19–20 mN/m. The relative intensities of the IR spectrum bands change from the KBr pellet to the LB film which is also attributable to orientation effects in the film. Cyclic voltammetric experiments of LB films incorporating the ZnPc derivative show peaks that can be correlated with redox processes occurring in the phthalocyanine ring. A small but significant influence of the surface pressure and the number of deposited layers in the electrochemical behaviour is observed. The electrochemical response of cast films exhibits some differences with respect to that of LB films which have been attributed to their different molecular

Microscopic study of carrier transport in the organic semiconductor zinc-phthalocyanine

Energy Technology Data Exchange (ETDEWEB)

Duarte, Joao Piroto [ESTeSC, Polytechnic Institute of Coimbra, 3040-854 Coimbra (Portugal); CEMDRX, Physics Department, University of Coimbra, Rua Larga, 3004-516 Coimbra (Portugal); Alberto, Helena Vieira; Vilao, Rui Cesar; Gil, Joao M.; Weidinger, Alois; Campos, Nuno Ayres de [CEMDRX, Physics Department, University of Coimbra, Rua Larga, 3004-516 Coimbra (Portugal)

2010-04-15

Nominally undoped zinc-phthalocyanine (ZnPc) was investigated using Muon Spin Rotation ({mu}SR) to probe microscopic carrier transport properties. The study focused on the relaxation of the positive muon's polarisation produced by spin-flip scattering with charge carriers. An energy of 71(8) meV was found for the temperature activation of carrier jumps, a value that does not match the activation energies known in ZnPc from electrical measurements, and that was attributed to a fast transport component in this material. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Improved Performance of Fluorinated Copper Phthalocyanine Thin Film Transistors Using Para-hexaphenyl as the Inducing Layer

International Nuclear Information System (INIS)

Ma Feng; Wang Shi-Rong; Li Xiang-Gao; Yan Dong-Hang

2011-01-01

We demonstrate n-type organic thin film transistors (OTFTs) employing copper hexadecafluorophthalocyanine (CuPcF 16 ) as the active layer and para-hexaphenyl (p-6p) as the inducing layer. Compared with the CuPcF 16 -based OTFTs without the p-6p inducing layer, the performance of the CuPcF 16 /p-6p OTFTs is greatly improved. The charge carrier field-effect mobility μ, on-off current ratio I on /I off and threshold voltage V T of the CuPcF 16 /p-6p OTFTs are 0.07 cm 2 /V·s, 1.61 × 10 5 and 6.28 V, respectively, approaching the level of a single crystal device. The improved performance is attributed to the introduction of p-6p to form a highly oriented and continuous film of CuPcF 16 with the molecular π-π stack direction parallel to the substrate. (cross-disciplinary physics and related areas of science and technology)

Characterization of manganese tetraarylthiosubstituted phthalocyanines self assembled monolayers

International Nuclear Information System (INIS)

Matemadombo, Fungisai; Durmus, Mahmut; Togo, Chamunorwa; Limson, Janice; Nyokong, Tebello

2009-01-01

Manganese tetraarylthiosubstituted phthalocyanines (complexes 1-5) have been deposited on Au electrode surfaces through the self assembled monolayer (SAM) technique. SAM characteristics reported in this work are: ion barrier factor (∼1); interfacial capacitance (303-539 μF cm -2 ) and surface coverage (1.06 x 10 -10 -2.80 x 10 -10 mol cm -2 ). Atomic force microscopy was employed in characterizing a SAM. SAMs of complexes 1-5 were employed to detect L-cysteine (with limit of detection ranging from 2.83 x 10 -7 to 3.14 x 10 -7 M at potentials of 0.68-0.75 V vs. Ag|AgCl) and nitrite (limit of detection ranging from 1.78 x 10 -7 to 3.02 x 10 -7 M at potentials of 0.69-0.76 V vs. Ag|AgCl).

Stability of dispersions in polar organic media. I. Electrostatic stabilization

NARCIS (Netherlands)

Rooy, N. de; Bruyn, P.L. de; Overbeek, J.Th.G.

Electrostatically stabilized sols of silver, silver iodide, α-goethite, and copper phthalocyanine in methanol, ethanol, isopropanol, and acetone have been prepared and characterized. Coagulation concentrations with electrolytes of various charge numbers have been determined in water, in organic

Elucidating the interplay between dark current coupling and open circuit voltage in organic photovoltaics

KAUST Repository

Erwin, Patrick; Thompson, Mark E.

2011-01-01

made with the structure indium tin oxide/copper phthalocyanine (200 Å)/PDI (200 Å)/bathocuproine (100 Å)/aluminum (1000 Å). We found that PDIs with larger substituents produced higher open circuit voltages (VOC's) despite the donor acceptor interface

Effect of diblock copolymer properties on the photophysical properties of dendrimer silicon phthalocyanine nanoconjugates

Science.gov (United States)

Chen, Kuizhi; Pan, Sujuan; Zhuang, Xuemei; Lv, Hafei; Que, Shoulin; Xie, Shusen; Yang, Hongqin; Peng, Yiru

2016-07-01

1-2 generation poly(benzyl aryl ether) dendrimer silicon phthalocyanines with axially disubstituted cyano terminal functionalities (G n -DSiPc(CN)4 n , (G n = n-generation dendrimer, n = 1-2)) were synthesized. Their structures were characterized by elemental analysis, IR, 1H NMR, and ESI-MS. Polymeric nanoparticles (G n -DSiPc(CN)4 n /m) were formed through encapsulating G n -DSiPc(CN)4 n into three monomethoxyl poly(ethylene glycol)-poly(ɛ-caprolactone) diblock copolymers (MPEG-PCL) with different hydrophilic/hydrophobic proportion, respectively. The effect of dendritic generation and the hydrophilic/hydrophobic proportion of diblock copolymers on the UV/Vis and fluorescence spectra of G n -DSiPc(CN)4 n and G n -DSiPc(CN)4 n /m were studied. The photophysical properties of polymeric nanoparticles exhibited dendritic generation and hydrophilic/hydrophobic proportion dependence. The fluorescence intensities and lifetimes of G n -DSiPc(CN)4 n /m were lower than the corresponding free dendrimer phthalocyanines. G n -DSiPc(CN)4 n encapsulated into MPEG-PCL with hydrophilic/hydrophobic molecular weight ratio 2000:4000 exhibited excellent photophysical property. The mean diameter of MPEG2000-PCL2000 micelles was about 70 nm, which decreased when loaded with G n -DSiPc(CN)4 n .

The use of chloroaluminium phthalocyanine tetrasulfonate (AlPcTS) for time-delayed fluorescence imaging

International Nuclear Information System (INIS)

Gundy, Sarah; Putten, Wil van der; Shearer, Andy; Buckton, Daniel; Ryder, Alan G; Ball, Michael

2004-01-01

Phthalocyanine derivatives are currently under investigation for use in photodynamic therapy, which is a promising cancer treatment. These materials, which display preferential uptake in cancerous cells, also exhibit high fluorescence yields and can be used for tumour detection. Problems with steady-state fluorescence techniques such as excitation scatter and background autofluorescence can be eliminated by using time-resolved imaging techniques without the need for filters. A tissue phantom was assembled to test a constructed time-gated imaging system by drilling 36 wells of varying diameter and depth (10 mm to 1 mm) into a block of polymethyl methacrylate (PMMA). The system was used to record images of chloroaluminium phthalocyanine tetrasulfonate (AlPcTS) at differing concentrations in neat aqueous solvent and cell suspensions within the wells. A mixture of Intralipid (to mimic tissue scatter) and Evan's blue (to mimic tissue absorption) of depths ranging from 1 mm to 10 mm was placed on top of the PMMA block. The ensuing images were analysed using signal-to-noise ratios and contrast-detail curves. The results indicate that the time-gated imaging system can prevent background excitation scatter from distorting the fluorescence signal from a longer-lived photosensitizer without the need for filters

Copper and copper-nickel-alloys - An overview

Energy Technology Data Exchange (ETDEWEB)

Klassert, Anton; Tikana, Ladji [Deutsches Kupferinstitut e.V. Am Bonneshof 5, 40474 Duesseldorf (Germany)

2004-07-01

With the increasing level of industrialization the demand for and the number of copper alloys rose in an uninterrupted way. Today, the copper alloys take an important position amongst metallic materials due to the large variety of their technological properties and applications. Nowadays there exist over 3.000 standardized alloys. Copper takes the third place of all metals with a worldwide consumption of over 15 millions tons per year, following only to steel and aluminum. In a modern industrial society we meet copper in all ranges of the life (electro-technology, building and construction industry, mechanical engineering, automotive, chemistry, offshore, marine engineering, medical applications and others.). Copper is the first metal customized by humanity. Its name is attributed to the island Cyprus, which supplied in the antiquity copper to Greece, Rome and the other Mediterranean countries. The Romans called it 'ore from Cyprus' (aes cyprium), later cuprum. Copper deposited occasionally also dapper and could be processed in the recent stone age simply by hammering. Already in early historical time copper alloys with 20 to 50 percent tin was used for the production of mirrors because of their high reflecting power. Although the elementary nickel is an element discovered only recently from a historical perspective, its application in alloys - without any knowledge of the alloy composition - occurred at least throughout the last 2.000 years. The oldest copper-nickel coin originates from the time around 235 B.C.. Only around 1800 AD nickel was isolated as a metallic element. In particular in the sea and offshore technology copper nickel alloys found a broad field of applications in piping systems and for valves and armatures. The excellent combination of characteristics like corrosion resistance, erosion stability and bio-fouling resistance with excellent mechanical strength are at the basis of this success. An experience of many decades supports the use

Fluorination of Metal Phthalocyanines: Single-Crystal Growth, Efficient N-Channel Organic Field-Effect Transistors, and Structure-Property Relationships

Science.gov (United States)

Jiang, Hui; Ye, Jun; Hu, Peng; Wei, Fengxia; Du, Kezhao; Wang, Ning; Ba, Te; Feng, Shuanglong; Kloc, Christian

2014-01-01

The fluorination of p-type metal phthalocyanines produces n-type semiconductors, allowing the design of organic electronic circuits that contain inexpensive heterojunctions made from chemically and thermally stable p- and n-type organic semiconductors. For the evaluation of close to intrinsic transport properties, high-quality centimeter-sized single crystals of F16CuPc, F16CoPc and F16ZnPc have been grown. New crystal structures of F16CuPc, F16CoPc and F16ZnPc have been determined. Organic single-crystal field-effect transistors have been fabricated to study the effects of the central metal atom on their charge transport properties. The F16ZnPc has the highest electron mobility (~1.1 cm2 V−1 s−1). Theoretical calculations indicate that the crystal structure and electronic structure of the central metal atom determine the transport properties of fluorinated metal phthalocyanines. PMID:25524460

Precursors for formation of copper selenide, indium selenide, copper indium diselenide, and/or copper indium gallium diselenide films

Science.gov (United States)

Curtis, Calvin J; Miedaner, Alexander; Van Hest, Maikel; Ginley, David S

2014-11-04

Liquid-based precursors for formation of Copper Selenide, Indium Selenide, Copper Indium Diselenide, and/or copper Indium Galium Diselenide include copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent. These liquid-based precursors can be deposited in liquid form onto substrates and treated by rapid thermal processing to form crystalline copper selenide and indium selenide films.

High-efficiency THz modulator based on phthalocyanine-compound organic films

International Nuclear Information System (INIS)

He, Ting; Zhang, Bo; Shen, Jingling; Zang, Mengdi; Chen, Tianji; Hu, Yufeng; Hou, Yanbing

2015-01-01

We report a high efficiency, broadband terahertz (THz) modulator following a study of phthalocyanine-compound organic films irradiated with an external excitation laser. Both transmission and reflection modulations of each organic/silicon bilayers were measured using THz time-domain and continuous-wave systems. For very low intensities, the experimental results show that AlClPc/Si can achieve a high modulation factor for transmission and reflection, indicating that AlClPc/Si has a superior modulation efficiency compared with the other films (CuPc and SnCl 2 Pc). In contrast, the strong attenuation of the transmitted and reflected THz waves revealed that a nonlinear absorption process takes place at the organic/silicon interface

Advanced Copper Composites Against Copper-Tolerant Xanthomonas perforans and Tomato Bacterial Spot.

Science.gov (United States)

Strayer-Scherer, A; Liao, Y Y; Young, M; Ritchie, L; Vallad, G E; Santra, S; Freeman, J H; Clark, D; Jones, J B; Paret, M L

2018-02-01

Bacterial spot, caused by Xanthomonas spp., is a widespread and damaging bacterial disease of tomato (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant Xanthomonas perforans. In vitro, metallic copper from CS-Cu and FQ-Cu at 100 μg/ml killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100 to 1,000 μg/ml) from Kocide 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared with the water control (P copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared with copper-mancozeb and water controls (P copper composites significantly reduced disease severity when compared with water controls, using 80% less metallic copper in comparison with copper-mancozeb in field studies (P copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.

Layered composites of PEDOT/PSS/nanoparticles and PEDOT/PSS/phthalocyanines as electron mediators for sensors and biosensors

Directory of Open Access Journals (Sweden)

Celia García-Hernández

2016-12-01

Full Text Available The sensing properties of electrodes chemically modified with PEDOT/PSS towards catechol and hydroquinone sensing have been successfully improved by combining layers of PEDOT/PSS with layers of a secondary electrocatalytic material such as gold nanoparticles (PEDOT/PSS/AuNPs, copper phthalocyanine (PEDOT/PSS/CuPc or lutetium bisphthalocyanine (PEDOT/PSS/LuPc2. Layered composites exhibit synergistic effects that strongly enhance the electrocatalytic activity as indicated by the increase in intensity and the shift of the redox peaks to lower potentials. A remarkable improvement has been achieved using PEDOT/PSS/LuPc2, which exhibits excellent electrocatalytic activity towards the oxidation of catechol. The kinetic studies demonstrated diffusion-controlled processes at the electrode surfaces. The kinetic parameters such as Tafel slopes and charge transfer coefficient (α confirm the improved electrocatalytic activity of the layered electron mediators. The peak currents increased linearly with concentration of catechol and hydroquinone over the range of 1.5 × 10−4 to 4.0 × 10−6 mol·L−1 with a limit of detection on the scale of μmol·L−1. The layered composite hybrid systems were also found to be excellent electron mediators in biosensors containing tyrosinase and laccase, and they combine the recognition and biocatalytic properties of biomolecules with the unique catalytic features of composite materials. The observed increase in the intensity of the responses allowed detection limits of 1 × 10−7 mol·L−1 to be attained.

Nanostructured nickel (II) phthalocyanine-MWCNTs as viable nanocomposite platform for electrocatalytic detection of asulam pesticide at neutral pH conditions

CSIR Research Space (South Africa)

Siswana, MP

2010-08-01

Full Text Available This work reports for the first time that nanostructured nickel (II) phthalocyanine/multiwalled carbon nanotubes composite supported on a basal plane pyrolytic electrode (NiPcNP/MWCNT-BPPGE) could potentially serve as a viable platform...

Copper as a target for prostate cancer therapeutics: copper-ionophore pharmacology and altering systemic copper distribution

Science.gov (United States)

Denoyer, Delphine; Pearson, Helen B.; Clatworthy, Sharnel A.S.; Smith, Zoe M.; Francis, Paul S.; Llanos, Roxana M.; Volitakis, Irene; Phillips, Wayne A.; Meggyesy, Peter M.; Masaldan, Shashank; Cater, Michael A.

2016-01-01

Copper-ionophores that elevate intracellular bioavailable copper display significant therapeutic utility against prostate cancer cells in vitro and in TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mice. However, the pharmacological basis for their anticancer activity remains unclear, despite impending clinical trails. Herein we show that intracellular copper levels in prostate cancer, evaluated in vitro and across disease progression in TRAMP mice, were not correlative with copper-ionophore activity and mirrored the normal levels observed in patient prostatectomy tissues (Gleason Score 7 & 9). TRAMP adenocarcinoma cells harbored markedly elevated oxidative stress and diminished glutathione (GSH)-mediated antioxidant capacity, which together conferred selective sensitivity to prooxidant ionophoric copper. Copper-ionophore treatments [CuII(gtsm), disulfiram & clioquinol] generated toxic levels of reactive oxygen species (ROS) in TRAMP adenocarcinoma cells, but not in normal mouse prostate epithelial cells (PrECs). Our results provide a basis for the pharmacological activity of copper-ionophores and suggest they are amendable for treatment of patients with prostate cancer. Additionally, recent in vitro and mouse xenograft studies have suggested an increased copper requirement by prostate cancer cells. We demonstrated that prostate adenocarcinoma development in TRAMP mice requires a functional supply of copper and is significantly impeded by altered systemic copper distribution. The presence of a mutant copper-transporting Atp7b protein (tx mutation: A4066G/Met1356Val) in TRAMP mice changed copper-integration into serum and caused a remarkable reduction in prostate cancer burden (64% reduction) and disease severity (grade), abrogating adenocarcinoma development. Implications for current clinical trials are discussed. PMID:27175597

Enhanced power conversion efficiency of p-i-n type organic solar cells by employing a p-layer of palladium phthalocyanine

KAUST Repository

Kim, Inho

2010-11-15

We demonstrate an enhancement in the power conversion efficiency (PCE) of p-i-n type organic solar cells consisting of zinc phthalocyanine (ZnPc) and fullerene (C60) using a p-layer of palladium phthalocyanine (PdPc). Solar cells employing three different device structures such as ZnPc/ZnPc:C60/C60, PdPc/PdPc:C60/C60, and PdPc/ZnPc:C60/C60 with varying thickness of mixed interlayers were fabricated by thermal evaporation. The mixed i-layers were deposited by co-evaporation of MPc (M=Zn,Pd) and C60 by 1:1 ratio. PCE of 3.7% was obtained for optimized cells consisting of PdPc/ZnPc:C60/C60, while cells with device structure of ZnPc/ZnPc:C60/C60 showed PCE of 3.2%.

Supramolecular architectures in layer-by-layer films of single-walled carbon nanotubes, chitosan and cobalt (II) phthalocyanine

International Nuclear Information System (INIS)

Sousa Luz, Roberto A. de; Martins, Marccus Victor A.; Magalhaes, Janildo L.; Siqueira, Jose R.; Zucolotto, Valtencir; Oliveira, Osvaldo N.; Crespilho, Frank N.; Cantanhede da Silva, Welter

2011-01-01

Highlights: → Platforms were assembled from cobalt phthalocyanine, chitosan and carbon nanotubes. → Supramolecular organization of multilayer films was investigated. → Increase of the supramolecular charge transfer after carbon nanotube incorporation. → Functional modulation based on constitutional dynamic chemistry was achieved. - Abstract: The building of supramolecular structures in nanostructured films has been exploited for a number of applications, with the film properties being controlled at the molecular level. In this study, we report on the layer-by-layer (LbL) films combining cobalt (II) tetrasulfonated phthalocyanine (CoTsPc), chitosan (Chit) and single-walled carbon nanotubes (SWCNTs) in two architectures, {Chit/CoTsPc} n and {Chit-SWCNTs/CoTsPc} n (n = 1-10). The physicochemical properties of the films were evaluated and the multilayer formation was monitored with microgravimetry measurements using a quartz microbalance crystal and an electrochemical technique. According to atomic force microscopy (AFM) results, the incorporation of SWCNTs caused the films to be thicker, with a thickness ca. 3 fold that of a 2-bilayer LbL film with no SWCNTs. Cyclic voltammetry revealed a quasi-reversible, one electron process with E 1/2 at -0.65 V (vs SCE) and an irreversible oxidation process at 0.80 V in a physiological medium for both systems, which can be attributed to [CoTsPc(I)] 5- /[CoTsPc(II)] 4- and CoTsPc(II) to CoTsPc(III), respectively. The {Chit-SWCNTs/CoTsPc} 5 multilayer film exhibited an increased faradaic current, probably associated with the supramolecular charge transfer interaction between cobalt phthalocyanine and SWCNTs. The results demonstrate that an intimate contact at the supramolecular level between functional SWCNTs immobilized into biocompatible chitosan polymer and CoTsPc improves the electron flow from CoTsPc redox sites to the electrode surface.

Adsorption energy of iron-phthalocyanine on crystal surfaces

International Nuclear Information System (INIS)

Struzzi, C.; Scardamaglia, M.; Angelucci, M; Massimi, L.; Mariani, C.; Betti, G.

2013-01-01

The adsorption energy of iron-phthalocyanine (FePc) deposited on different crystal surfaces is studied by thermal desorption spectroscopy. A thin film of molecules has been absorbed on highly oriented pyrolytic graphite (HOPG), on graphene epitaxially grown on Ir(111), and on Au(110). Activation energies for the desorption of a molecular thin film and for the FePc single layer are determined at the three surfaces. The desorption temperature measured for the thin films is only slightly dependent on the substrate, since it is mostly dominated by molecule-molecule interactions. A definitely different desorption temperature is found at the single-layer coverage: we find an increasing desorption temperature going from HOPG, to graphene/Ir, to the Au(110) surface. The different adsorption energies of the first FePc layer in contact with the substrate surface are discussed taking into account the interaction and the growth morphology.

Native copper as a natural analogue for copper canisters

International Nuclear Information System (INIS)

Marcos, N.

1989-12-01

This paper discusses the occurrence of native copper as found in geological formations as a stability analogue of copper canisters that are planned to be used for the disposal of spent nuclear fuel in the Finnish bedrock. A summary of several publications on native copper occurrences is presented. The present geochemical and geohydrological conditions in which copper is met with in its metallic state show that metallic copper is stable in a wide range of temperatures. At low temperatures native copper is found to be stable where groundwater has moderate pH (about 7), low Eh (< +100 mV), and low total dissolved solids, especially chloride. Microscopical and microanalytical studies were carried out on a dozen of rock samples containing native copper. The results reveal that the metal shows no significant alteration. Only the surface of copper grains is locally coated. In the oldest samples there exist small corrosion cracks; the age of the oldest samples is over 1,000 million years. A review of several Finnish groundwater studies suggests that there are places in Finland where the geohydrological conditions are favourable for native copper stability. (orig.)

Do primary health centres and hospitals contribute equally towards achievement of the transversal clinical competencies of medical students? Performance on the Objective Structured Clinical Examination (OSCE) in competency acquisition.

Science.gov (United States)

Soler-González, Jorge; Buti, Miquel; Boada, Jordi; Ayala, Victoria; Peñascal, Eduard; Rodriguez, Toni

2016-01-01

The adaptation of the educational programmes of European faculties of medicine to the European Higher Education Area guidelines has focused curricula design on competence acquisition. Competencies are defined as the achievements of a predetermined level of efficacy in real-world scenarios. Our objective was to assess whether performance on a common competence evaluation test, the Objective Structured Clinical Examination (OSCE), resulted in different scores for second-year students after a practical medical training course took place in a primary health centre (PHC) or in a hospital. A descriptive study was conducted during the 2010-2014 academic year of the OSCE test scores obtained by all second-year students. Faculty of Medicine at the University of Lleida (Catalonia, Spain). We performed a correlation analysis between students who completed their practical medical training at the PHC and hospitals utilising Student's t-test for comparison of means. 423 students who completed internships at the PHC and at hospitals obtained OSCE mean scores of 7.32 (SD; IC) (0.82; 7.18-7.47) points and 7.17 (0.83; 6.07-7.26) points, respectively (p=0.07). Second-year medical students acquired similar competency levels in the two analysed training scenarios. The two areas both serve their teaching purpose. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Raman spectra of zinc phthalocyanine monolayers absorbed on glassy carbon and gold electrodes by application of a confocal Raman microspectrometer

NARCIS (Netherlands)

Palys-Staron, B.J.; Palys, B.J.; Puppels, G.J.; Puppels, G.J.; van den Ham, D.M.W.; van den Ham, D.M.W.; Feil, D.; Feil, D.

1992-01-01

Raman spectra of zinc phthalocyanine monolayers, adsorbed on gold and on glassy carbon surfaces (electrodes), are presented. These spectra have been recorded with the electrodes inside and outside an electrochemical cell filled with an aqueous electrolyte. A confocal Raman microspectrometer was

Some Phthalocyanine and Naphthalocyanine Derivatives as Corrosion Inhibitors for Aluminium in Acidic Medium: Experimental, Quantum Chemical Calculations, QSAR Studies and Synergistic Effect of Iodide Ions

Directory of Open Access Journals (Sweden)

Masego Dibetsoe

2015-08-01

Full Text Available The effects of seven macrocyclic compounds comprising four phthalocyanines (Pcs namely 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (Pc1, 2,3,9,10,16,17,23,24-octakis(octyloxy-29H,31H-phthalocyanine (Pc2, 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (Pc3 and 29H,31H-phthalocyanine (Pc4, and three naphthalocyanines namely 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine (nPc1, 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine (nPc2 and 2,3-naphthalocyanine (nP3 were investigated on the corrosion of aluminium (Al in 1 M HCl using a gravimetric method, potentiodynamic polarization technique, quantum chemical calculations and quantitative structure activity relationship (QSAR. Synergistic effects of KI on the corrosion inhibition properties of the compounds were also investigated. All the studied compounds showed appreciable inhibition efficiencies, which decrease with increasing temperature from 30 °C to 70 °C. At each concentration of the inhibitor, addition of 0.1% KI increased the inhibition efficiency compared to the absence of KI indicating the occurrence of synergistic interactions between the studied molecules and I− ions. From the potentiodynamic polarization studies, the studied Pcs and nPcs are mixed type corrosion inhibitors both without and with addition of KI. The adsorption of the studied molecules on Al surface obeys the Langmuir adsorption isotherm, while the thermodynamic and kinetic parameters revealed that the adsorption of the studied compounds on Al surface is spontaneous and involves competitive physisorption and chemisorption mechanisms. The experimental results revealed the aggregated interactions between the inhibitor molecules and the results further indicated that the peripheral groups on the compounds affect these interactions. The calculated quantum chemical parameters and the QSAR results revealed the possibility of strong interactions between the studied inhibitors and metal surface. QSAR

Formation of copper-indium-selenide and/or copper-indium-gallium-selenide films from indium selenide and copper selenide precursors

Science.gov (United States)

Curtis, Calvin J [Lakewood, CO; Miedaner, Alexander [Boulder, CO; Van Hest, Maikel [Lakewood, CO; Ginley, David S [Evergreen, CO; Nekuda, Jennifer A [Lakewood, CO

2011-11-15

Liquid-based indium selenide and copper selenide precursors, including copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent, are used to form crystalline copper-indium-selenide, and/or copper indium gallium selenide films (66) on substrates (52).

COPPER AND COPPER-CONTAINING PESTICIDES: METABOLISM, TOXICITY AND OXIDATIVE STRESS

Directory of Open Access Journals (Sweden)

Viktor Husak

2015-05-01

Full Text Available The purpose of this paper is to provide a brief review of the current knowledge regarding metabolism and toxicity of copper and copper-based pesticides in living organisms. Copper is an essential trace element in all living organisms (bacteria, fungi, plants, and animals, because it participates in different metabolic processes and maintain functions of organisms. The transport and metabolism of copper in living organisms is currently the subject of many studies. Copper is absorbed, transported, distributed, stored, and excreted in the body via the complex of homeostatic processes, which provide organisms with a needed constant level of this micronutrient and avoid excessive amounts. Many aspects of copper homeostasis were studied at the molecular level. Copper based-pesticides, in particularly fungicides, bacteriocides and herbicides, are widely used in agricultural practice throughout the world. Copper is an integral part of antioxidant enzymes, particularly copper-zinc superoxide dismutase (Cu,Zn-SOD, and plays prominent roles in iron homeostasis. On the other hand, excess of copper in organism has deleterious effect, because it stimulates free radical production in the cell, induces lipid peroxidation, and disturbs the total antioxidant capacity of the body. The mechanisms of copper toxicity are discussed in this review also.

Uptake and internalisation of copper by three marine microalgae: comparison of copper-sensitive and copper-tolerant species.

Science.gov (United States)

Levy, Jacqueline L; Angel, Brad M; Stauber, Jennifer L; Poon, Wing L; Simpson, Stuart L; Cheng, Shuk Han; Jolley, Dianne F

2008-08-29

Although it has been well established that different species of marine algae have different sensitivities to metals, our understanding of the physiological and biochemical basis for these differences is limited. This study investigated copper adsorption and internalisation in three algal species with differing sensitivities to copper. The diatom Phaeodactylum tricornutum was particularly sensitive to copper, with a 72-h IC50 (concentration of copper to inhibit growth rate by 50%) of 8.0 microg Cu L(-1), compared to the green algae Tetraselmis sp. (72-h IC50 47 microg Cu L(-1)) and Dunaliella tertiolecta (72-h IC50 530 microg Cu L(-1)). At these IC50 concentrations, Tetraselmis sp. had much higher intracellular copper (1.97+/-0.01 x 10(-13)g Cu cell(-1)) than P. tricornutum (0.23+/-0.19 x 10(-13)g Cu cell(-1)) and D. tertiolecta (0.59+/-0.05 x 10(-13)g Cu cell(-1)), suggesting that Tetraselmis sp. effectively detoxifies copper within the cell. By contrast, at the same external copper concentration (50 microg L(-1)), D. tertiolecta appears to better exclude copper than Tetraselmis sp. by having a slower copper internalisation rate and lower internal copper concentrations at equivalent extracellular concentrations. The results suggest that the use of internal copper concentrations and net uptake rates alone cannot explain differences in species-sensitivity for different algal species. Model prediction of copper toxicity to marine biota and understanding fundamental differences in species-sensitivity will require, not just an understanding of water quality parameters and copper-cell binding, but also further knowledge of cellular detoxification mechanisms.

Electrocatalytic behahiour of cobalt tetraamino-phthalocyanine in the presence of a composite of reduced graphene nanosheets and of multi-walled carbon nanotubes

International Nuclear Information System (INIS)

Nyoni, Stephen; Nyokong, Tebello

2014-01-01

Graphical abstract: A composite of multi-walled carbon nanotubes, reduced graphene nanosheets and cobalt tetraamino phthalocyanine was used for electrode modification, resulting in a rough surface as judged by scanning electrochemical microscopy. - Highlights: • Conjugates of multi-walled carbon nanotubes and reduced graphene nanosheets were used to modify glassy carbon electrode. • The electrode was further modified with cobalt tetraamino phthalocyanine. • The modified electrode was employed for the detection of paraquat. • A mechanism for paraquat detection using the composite electrodes is proposed. - Abstract: A composite of multi-walled carbon nanotubes (MWCNT) with reduced graphene nanosheets (rGNS-2) was developed in order to minimize the restacking of the latter. The composite was used to modify a glassy carbon electrode (GCE). GCE was further modified with cobalt tetraamino phthalocyanine (CoTAPc). The modified electrode is represented as rGNS-2-MWCNT-CoTAPc-GCE. X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electrochemical microscopy and Raman spectroscopy were used to explore into surface functionalities, morphology and topography of the nanocomposite. The rGNS-2-MWCNT-CoTAPc-GCE had a low limit of detection of 3.32 × 10 −8 M towards the detection of paraguat as a test analyte. A mechanism for paraquat detection using an rGNS-2-MWCNT-CoTAPc-GCE is also proposed in this work

Self-Assembly of Individually Addressable Complexes of C-60 and Phthalocyanines on a Metal Surface : Structural and Electronic Investigations

NARCIS (Netherlands)

Samuely, Tomas; Liu, Shi-Xia; Haas, Marco; Decurtins, Silvio; Jung, Thomas A.; Stoehr, Meike

2009-01-01

The hosting properties of a close-packed layer of phenoxy-substituted phthalocyanine derivatives adsorbed on Ag(III) were investigated for the adsorption of C-60 molecules. The C-60 molecules bind to two clearly distinguishable sites, namely, to the underlying metal substrate in between two adjacent

Plasmon-enhanced photocurrent generation from self-assembled monolayers of phthalocyanine by using gold nanoparticle films.

Science.gov (United States)

Sugawa, Kosuke; Akiyama, Tsuyoshi; Kawazumi, Hirofumi; Yamada, Sunao

2009-04-09

The effect of localized electric fields on the photocurrent responses of phthalocyanine that was self-assembled on a gold nanoparticle film was investigated by comparing the conventional and the total internal reflection (TIR) experimental systems. In the case of photocurrent measurements, self-assembled monolayers (SAMs) of a thiol derivative of palladium phthalocyanine (PdPc) were prepared on the surface of gold-nanoparticle film that was fixed on the surface of indium-tin-oxide (ITO) substrate via a polyion (PdPc/AuP/polyion/ITO) or on the ITO surface (PdPc/ITO). Photocurrent action spectra from the two samples were compared by using the conventional spectrometer, and were found that PdPc/AuP/polyion/ITO gave considerably larger photocurrent signals than PdPc/ITO under the identical concentration of PdPc. In the case of the TIR experiments for the PdPc/AuP/polyion/ITO and the PdPc/AuP/Glass systems, incident-angle profiles of photocurrent and emission signals were correlated with each other, and they were different from that of the PdPc/ITO system. Accordingly, it was demonstrated that the photocurrent signals were certainly enhanced by the localized electric fields of the gold-nanoparticle film.

Assessing the potential of group 13 and 14 metal/metalloid phthalocyanines as hole transport layers in organic light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Plint, Trevor; Lessard, Benoît H. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5 (Canada); Bender, Timothy P. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5 (Canada); Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto, Ontario M5S 3E4 (Canada); Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 (Canada)

2016-04-14

In this study, we have assessed the potential application of group 13 and 14 metal and metalloid phthalocyanines ((X){sub n}-MPcs) and their axially substituted derivatives as hole-transporting layers in organic light emitting diodes (OLEDs). OLEDs studied herein have the generic structure of glass/ITO/(N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) or (X){sub n}-MPc)(50 nm)/Alq{sub 3} (60 nm)/LiF (1 nm)/Al (80 nm), where X is an axial substituent group. OLEDs using chloro aluminum phthalocyanine (Cl-AlPc) showed good peak luminance values of 2620 ± 113 cd/m{sup 2} at 11 V. To our knowledge, Cl-AlPc has not previously been shown to work as a hole transport material (HTL) in OLEDs. Conversely, the di-chlorides of silicon, germanium, and tin phthalocyanine (Cl{sub 2}-SiPc, Cl{sub 2}-GePc, and Cl{sub 2}-SnPc, respectively) showed poor performance compared to Cl-AlPc, having peak luminances of only 38 ± 4 cd/m{sup 2} (12 V), 23 ± 1 cd/m{sup 2} (8.5 V), and 59 ± 5 cd/m{sup 2} (13.5 V), respectively. However, by performing a simple axial substitution of the chloride groups of Cl{sub 2}-SiPc with pentafluorophenoxy groups, the resulting bis(pentafluorophenoxy) silicon phthalocyanine (F{sub 10}-SiPc) containing OLED had a peak luminance of 5141 ± 941 cd/m{sup 2} (10 V), a two order of magnitude increase over its chlorinated precursor. This material showed OLED characteristics approaching those of a baseline OLED based on the well-studied triarylamine NPB. Attempts to attach the pentafluorophenoxy axial group to both SnPc and GePc were hindered by synthetic difficulties and low thermal stability, respectively. In light of the performance improvements observed by simple axial substitution of SiPc in OLEDs, the use of axially substituted MPcs in organic electronic devices remains of continuing interest to us and potentially the field in general.

Nanostructuring on zinc phthalocyanine thin films for single-junction organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Chaudhary, Dhirendra K.; Kumar, Lokendra, E-mail: lokendrakr@allduniv.ac.in [Department of Physics, University of Allahabad, Allahabad-211 002 (India)

2016-05-23

Vertically aligned and random oriented crystalline molecular nanorods of organic semiconducting Zinc Phthalocyanine (ZnPc) have been grown on ITO coated glass substrate using solvent volatilization method. Interesting changes in surface morphology were observed under different solvent treatment. Vertically aligned nanorods of ZnPc thin film were observed in the films treated with acetone, where as the random oriented nanorods were observed in the films treated with chloroform. The X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) have been used for characterization of nanostructures. The optical properties of the nanorods have been investigated by UV-Vis. absorption spectroscopy.

Facile fabrication of dual emissive nanospheres via the self-assembling of CdSe@CdS and zinc phthalocyanine and their application for silver ion detection

Science.gov (United States)

Liu, Shuning; Liu, Chenchen; Luan, Xinying; Yao, Rui; Feng, Yakai

2017-09-01

The far-red/near infrared photoluminescence of zinc phthalocyanines would be strongly quenched once they are aggregated, which will obviously hinder their wide applications in environmental, energy related and biomedical fields. Herein, the ultra-small sized semiconductor quantum dots with core-shell structures (CdSe@CdS) have been firstly synthesized and then assembled with a dendritic zinc phthalocyanine (ZnPc) in the H2O/DMF mixed solvent to obtain monodispersed nanospheres. Finally, it was found that the resultant ethanolic colloids can be employed as a sensitive and specific fluorescent nanoprobe for silver ions discrimination with a limit of detection (LOD) approaching to 10-8 mol/L.

Micro-Encapsulated Porphyrins and Phthalocyanines - New Formulations in Photodynamic Therapy

Science.gov (United States)

Ion, R. M.

2017-06-01

Photodynamic therapy (PDT), as an innovative method for cancer tretament is based on a concerted action of some drugs, called sensitizers, which generate reactive oxygen species via a photochemical mechanism, leading to cellular necrosis or apoptosis. The present work aims at loading some sensitizers, as porphyrins (P) and phthalocyanines (Pc) into alginate particles. Particles were prepared by dropping alginate into an aqueous solution containing P or Pc and CaCl2, which allows the formation of particles through ionic crosslinking. It was obtained P or Pc loaded alginate beads with an average diameter of about 100 μm. For these systems, this paper analyses the spectroscopic properties, encapsulation into microcapsules, controlled releasing action and their photosensitizer capacity (singlet oxygen generation).

Significant Improvement of Organic Thin-Film Transistor Mobility Utilizing an Organic Heterojunction Buffer Layer

International Nuclear Information System (INIS)

Pan Feng; Qian Xian-Rui; Huang Li-Zhen; Wang Hai-Bo; Yan Dong-Hang

2011-01-01

High-mobility vanadyl phthalocyanine (VOPc)/5,5‴-bis(4-fluorophenyl)-2,2':5',2″:5″,2‴-quaterthiophene (F2-P4T) thin-film transistors are demonstrated by employing a copper hexadecafluorophthalocyanine (F 16 CuPc)/copper phthalocyanine (CuPc) heterojunction unit, which are fabricated at different substrate temperatures, as a buffer layer. The highest mobility of 4.08cm 2 /Vs is achieved using a F 16 CuPc/CuPc organic heterojunction buffer layer fabricated at high substrate temperature. Compared with the random small grain-like morphology of the room-temperature buffer layer, the high-temperature organic heterojunction presents a large-sized fiber-like film morphology, resulting in an enhanced conductivity. Thus the contact resistance of the transistor is significantly reduced and an obvious improvement in device mobility is obtained. (cross-disciplinary physics and related areas of science and technology)

Electrical Properties of Zn-Phthalocyanine and Poly (3-hexylthiophene Doped Nematic Liquid Crystal

Directory of Open Access Journals (Sweden)

Y. Karakuş

2011-01-01

Full Text Available An E7 coded nematic liquid crystal was doped with zinc phthalocyanine and poly (3-hexylthiophene. A variety of properties including relaxation time, absorption coefficient, and critical frequency of this doped system were investigated using impedance spectroscopy. The doped systems displayed increased absorption coefficients in the range 0.22–0.55 and relaxation times from 5.05×10−7 s to 3.59×10−6 s with a decrease in the critical frequency from 3.54 MHz to 2.048 MHz.

Tissue Distribution Of Chloroaluminium Sulfonated Phthalocyanine In Dogs

Science.gov (United States)

M. M.; H. C.; Newman

1989-06-01

Chloroaluminum sulfonated phthalocyanine (A1PCS) was administered intravenously to clinically normal dogs, and A1PCS levels were determined in tissues using a sensitive assay. A1PCS accumulated to high levels in liver, spleen, bone marrow, kidney, and lung. These tissue levels confirm previous determinations in mice and rats. Only a small amount of dye was retained in skin and very small amounts in muscle and brain. A1PCS was cleared from the blood within 24 h, and excreted primarily by urine. Serum clearance was faster in males than in females. There were also significant tissue distribution differences between the genders, particularly during the first 12 h. The low levels of A1PCS in skin suggest that cutaneous photosensitivity and toxic skin reactions using this photosensitizer in photodynamic therapy of cancer may be eliminated. The difference in tissue distribution between genders is not only intriguing, but indicates that the optimal time window for treatment of various tissue sites may vary by gender.

Phthalocyanines with eight oligo(ethylene oxide) alkoxy units: thermotropic phase behavior, aggregate formation and ion complexation with redox-active ions

NARCIS (Netherlands)

Piet, D.P.; Verheij, H.J.; Zuilhof, H.

2003-01-01

The thermotropic phase behavior of phthalocyanines (Pc's) with eight oligo(ethylene oxide) alkoxy side chains has been investigated. An increase in the number of ethylene oxide units results in a decrease in the solid-to-mesophase and isotropization temperatures. The investigated compounds display a

Electrical conduction in composites containing copper core-copper

Indian Academy of Sciences (India)

Composites of nanometre-sized copper core-copper oxide shell with diameters in the range 6.1 to 7.3 nm dispersed in a silica gel were synthesised by a technique comprising reduction followed by oxidation of a suitably chosen precursor gel. The hot pressed gel powders mixed with nanometre-sized copper particles ...

Nanocrystalline Axially Bridged Iron Phthalocyanine Polymeric Conductor: (μ-Thiocyanato(phthalocyaninatoiron(III

Directory of Open Access Journals (Sweden)

Eiza Shimizu

2016-01-01

Full Text Available Skewered Iron(III phthalocyanine conducting polymer can be constructed with the utilization of axial thiocyanato ligands ((μ-thiocyanato(phthalocyaninatoiron(III; (FeIII(Pc(SCNn thereby creating additional avenues for electron transport through a linear SCN bridge, apart from the intermolecular π-π orbital overlap between the Pc molecules. In this paper, we report on the conversion of bulk FeIII(Pc(SCNn polymeric organic conductor into crystalline nanostructures through horizontal vapor phase growth process. The needle-like nanostructures are deemed to provide more ordered and, thus, more π-π interactive interskewer FeIII(Pc(SCNn polymer orientation, resulting in a twofold increase of its electrical conductivity per materials density unit.

Effect of New Water-Soluble Dendritic Phthalocyanines on Human Colorectal and Liver Cancer Cell Lines

Directory of Open Access Journals (Sweden)

Ebru YABAŞ

2017-08-01

Full Text Available Human hepatocellular carcinoma (HepG2 cells and colorectal adenocarcinoma (DLD-1 cells were treated with the synthesized water soluble phthalocyanine derivatives to understand the effect of the compounds both on colorectal and liver cancer cells. The compounds inhibited cell proliferation and displayed cytotoxic effect on these cancer cell lines however; the effect of the compounds on healthy control fibroblast cell line was comparatively lower. The compounds can be employed for cancer treatment as anticancer agents.

Reagent conditions of the flotation of copper, copper - molybdenum and copper -zinc ores in foreing countries

International Nuclear Information System (INIS)

Nevaeva, L.M.

1983-01-01

Reagents-collectors and frothers, used abroad in reagent regimes of flotation of copper, copper-molybdenum and copper zinc ores, have been considered. Xanthogenates, aerofloats, xanthogenformiates, thionocarbamates are mainly used as reagents-collectors. Methylizobutylcarbinol and Daufros are used as reagents-frothers

Evaluation of Topical Photodynamic Therapy of Mammary Carcinoma with an Experimental Gel Containing Liposomal Hydroxyl-aluminium Phthalocyanine

Czech Academy of Sciences Publication Activity Database

Sutoris, K.; Větvička, D.; Horák, L.; Beneš, J.; Nekvasil, Miloš; Ježek, Petr; Zadinová, M.; Poučková, P.

2012-01-01

Roč. 32, č. 9 (2012), s. 3769-3774 ISSN 0250-7005 R&D Projects: GA MPO(CZ) 2A-1TP1/026; GA MŠk(CZ) OE09026; GA TA ČR(CZ) TA01010781 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : photodynamic therapy * phthalocyanine * liposomal sensitizer Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 1.713, year: 2012

Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

Directory of Open Access Journals (Sweden)

Zhengqi Guo

2016-04-01

Full Text Available In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of copper and iron.

Supramolecular architectures in layer-by-layer films of single-walled carbon nanotubes, chitosan and cobalt (II) phthalocyanine

Energy Technology Data Exchange (ETDEWEB)

Sousa Luz, Roberto A. de; Martins, Marccus Victor A.; Magalhaes, Janildo L. [Departamento de Quimica, Centro de Ciencias da Natureza, Universidade Federal do Piaui, Teresina - PI, CEP 64049-550 (Brazil); Siqueira, Jose R. [Instituto de Ciencias Exatas, Naturais e Educacao, Universidade Federal do Triangulo Mineiro, Uberaba - MG, CEP 38025-180, Brazil (Brazil); Zucolotto, Valtencir; Oliveira, Osvaldo N. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Sao Carlos - SP, CEP 13560-970 (Brazil); Crespilho, Frank N. [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Santo Andre - SP, CEP 09210-170 (Brazil); Cantanhede da Silva, Welter, E-mail: welter@ufpi.edu.br [Departamento de Quimica, Centro de Ciencias da Natureza, Universidade Federal do Piaui, Teresina - PI, CEP 64049-550 (Brazil)

2011-11-01

Highlights: {yields} Platforms were assembled from cobalt phthalocyanine, chitosan and carbon nanotubes. {yields} Supramolecular organization of multilayer films was investigated. {yields} Increase of the supramolecular charge transfer after carbon nanotube incorporation. {yields} Functional modulation based on constitutional dynamic chemistry was achieved. - Abstract: The building of supramolecular structures in nanostructured films has been exploited for a number of applications, with the film properties being controlled at the molecular level. In this study, we report on the layer-by-layer (LbL) films combining cobalt (II) tetrasulfonated phthalocyanine (CoTsPc), chitosan (Chit) and single-walled carbon nanotubes (SWCNTs) in two architectures, {l_brace}Chit/CoTsPc{r_brace}{sub n} and {l_brace}Chit-SWCNTs/CoTsPc{r_brace}{sub n} (n = 1-10). The physicochemical properties of the films were evaluated and the multilayer formation was monitored with microgravimetry measurements using a quartz microbalance crystal and an electrochemical technique. According to atomic force microscopy (AFM) results, the incorporation of SWCNTs caused the films to be thicker, with a thickness ca. 3 fold that of a 2-bilayer LbL film with no SWCNTs. Cyclic voltammetry revealed a quasi-reversible, one electron process with E{sub 1/2} at -0.65 V (vs SCE) and an irreversible oxidation process at 0.80 V in a physiological medium for both systems, which can be attributed to [CoTsPc(I)]{sup 5-}/[CoTsPc(II)]{sup 4-} and CoTsPc(II) to CoTsPc(III), respectively. The {l_brace}Chit-SWCNTs/CoTsPc{r_brace}{sub 5} multilayer film exhibited an increased faradaic current, probably associated with the supramolecular charge transfer interaction between cobalt phthalocyanine and SWCNTs. The results demonstrate that an intimate contact at the supramolecular level between functional SWCNTs immobilized into biocompatible chitosan polymer and CoTsPc improves the electron flow from CoTsPc redox sites to the

Effect of diblock copolymer properties on the photophysical properties of dendrimer silicon phthalocyanine nanoconjugates

Energy Technology Data Exchange (ETDEWEB)

Chen, Kuizhi [Fujian Normal University, College of Materials Science & Engineering, Fujian Provincial Key Laboratory of Polymer Materials (China); Pan, Sujuan [Fujian Normal University, College of Chemistry & Engineering (China); Zhuang, Xuemei [Fuzhou No.2 Hospital (China); Lv, Hafei; Que, Shoulin [Fujian Normal University, College of Chemistry & Engineering (China); Xie, Shusen; Yang, Hongqin, E-mail: hqyang@fjnu.edu.cn [Fujian Normal University, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education (China); Peng, Yiru, E-mail: yirupeng@fjnu.edu.cn [Fujian Normal University, College of Chemistry & Engineering (China)

2016-07-15

1–2 generation poly(benzyl aryl ether) dendrimer silicon phthalocyanines with axially disubstituted cyano terminal functionalities (G{sub n}-DSiPc(CN){sub 4n}, (G{sub n} = n-generation dendrimer, n = 1–2)) were synthesized. Their structures were characterized by elemental analysis, IR, {sup 1}H NMR, and ESI-MS. Polymeric nanoparticles (G{sub n}-DSiPc(CN){sub 4n}/m) were formed through encapsulating G{sub n}-DSiPc(CN){sub 4n} into three monomethoxyl poly(ethylene glycol)-poly(ε-caprolactone) diblock copolymers (MPEG–PCL) with different hydrophilic/hydrophobic proportion, respectively. The effect of dendritic generation and the hydrophilic/hydrophobic proportion of diblock copolymers on the UV/Vis and fluorescence spectra of G{sub n}-DSiPc(CN){sub 4n} and G{sub n}-DSiPc(CN){sub 4n}/m were studied. The photophysical properties of polymeric nanoparticles exhibited dendritic generation and hydrophilic/hydrophobic proportion dependence. The fluorescence intensities and lifetimes of G{sub n}-DSiPc(CN){sub 4n}/m were lower than the corresponding free dendrimer phthalocyanines. G{sub n}-DSiPc(CN){sub 4n} encapsulated into MPEG–PCL with hydrophilic/hydrophobic molecular weight ratio 2000:4000 exhibited excellent photophysical property. The mean diameter of MPEG{sub 2000}–PCL{sub 2000} micelles was about 70 nm, which decreased when loaded with G{sub n}-DSiPc(CN){sub 4n}.Graphical abstract .

21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT....1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). (a) Identity. (1) The color...

21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). (a) Identity and...

Al(III), Pd(II), and Zn(II) phthalocyanines for inactivation of dental pathogen Aggregatibacter actinomycetemcomitans as planktonic and biofilm-cultures

Science.gov (United States)

Kussovski, V.; Mantareva, V.; Angelov, I.; Avramov, L.; Popova, E.; Dimitrov, S.

2012-06-01

The Gram-negative, oral bacterium Aggregatibacter actinomycetemcomitans has been implicated as the causative agent of several forms of periodontal disease in humans. The new periodontal disease treatments are emergence in order to prevent infection progression. Antimicrobial photodynamic therapy (a-PDT) can be a useful tool for this purpose. It involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent in the presence of oxygen for eradication of target cells, and appears effective in photoinactivation of microorganisms. The phthalocyanine metal complexes of Pd(II)- (PdPcC) and Al(III)- (AlPc1) were evaluated as photodynamic sensitizers towards a dental pathogen A. actinomycetemcomitans in comparison to the known methylpyridyloxy-substituted Zn(II) phthalocyanine (ZnPcMe). The planktonic and biofilm-cultivated species of A. actinomycetemcomitans were treated. The photophysical results showed intensive and far-red absorbance with high tendency of aggregation for Pd(II)-phthalocyanine. The dark toxicities of both photosensitizers were negligible at concentrations used (bacteria was full photoinactivation after a-PDT with ZnPcMe. In case of the newly studied complexes, the effect was lower for PdPcC (4 log) as well as for AlPc1 (1.5-2 log). As it is known the bacterial biofilms were more resistant to a-PDT, which was confirmed for A. actinomycetemcomitans biofilms with 3 log reductions of viable cells after treatment with ZnPcMe and approximately 1 log reduction of biofilms after PdPcC and AlPc1. The initial results suggest that a-PDT can be useful for effective inactivation of dental pathogen A. actinomycetemcomitans.

Comparison of two photosensitizers Al(III) phthalocyanine chloride tetrasulfonic acid and meso-tetrakis(4-sulfonatophenyl)porphyrin in the photooxidation of n-butylparaben

Czech Academy of Sciences Publication Activity Database

Gmurek, M.; Kubát, Pavel; Mosinger, Jiří; Miller, J. S.

2011-01-01

Roč. 223, č. 1 (2011), s. 50-56 ISSN 1010-6030 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40320502 Keywords : photosensitization * porphyrin * phthalocyanine Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.421, year: 2011

Layer-by-layer composite film of nickel phthalocyanine and montmorillonite clay for synergistic effect on electrochemical detection of dopamine

Science.gov (United States)

de Lucena, Nathalia C.; Miyazaki, Celina M.; Shimizu, Flávio M.; Constantino, Carlos J. L.; Ferreira, Marystela

2018-04-01

Dopamine (DA) abnormal levels are related to diseases which makes important the development of fast, reliable, low-cost and sensitive devices for diagnosis and pharmaceutical controls. Nanostructured film composite of sodium montmorillonite clay (Na+MMT) and nickel phthalocyanine (NiTsPc) was self-assembled by layer-by-layer (LbL) technique and applied as electrochemical sensor for DA in the presence of common natural interferents as ascorbic acid (AA) and uric acid (UA). Three different LbL architecture films were investigated: LbL films of clay (PEI/Na+MMT) and phthalocyanine (PEI/NiTsPc) in a bilayer structure with a conventional polyelectrolyte (PEI) and a composite film formed by both materials to verify the synergistic effect in the LbL film in a quadri-layer assembly (PEI/Na+MMT/PEI/NiTsPc). Structural characterization indicated molecular level interactions between the layers forming the LbL films. The ITO/(PEI/Na+MMT/PEI/NiTsPc)10 electrode exhibited a LOD of 1.0 μmol L-1 and linear range 5-150 μmol L-1.

Novel water soluble morpholine substituted Zn(II) phthalocyanine: Synthesis, characterization, DNA/BSA binding, DNA photocleavage and topoisomerase I inhibition.

Science.gov (United States)

Barut, Burak; Demirbaş, Ümit; Özel, Arzu; Kantekin, Halit

2017-12-01

In this study, novel peripherally tetra 3-morpholinophenol substituted zinc(II) phthalocyanine (4) and its water soluble form quaternized zinc(II) phthalocyanine (ZnQ) were synthesized for the first time. These novel compounds were characterized by a combination of different spectroscopic techniques such as FT-IR, 1 H NMR, 13 C NMR, UV-vis and mass. The DNA binding of ZnQ was investigated using UV-vis absorption titration, competitive ethidium bromide, thermal denaturation and viscosity experiments that the ZnQ bound to CT-DNA via intercalation mode. ZnQ indicated photocleavage activity on supercoiled pBR322 plasmid DNA via formation of singlet oxygen under irradiation at 700nm. Besides, the topoisomerase I inhibitory effect experiments showed that ZnQ inhibited topoisomerase I enzyme in a concentration-dependent manner. The bovine serum albumin (BSA) binding experiments indicated that ZnQ bound to proteins through a static quenching mechanism. All of these results claim that ZnQ has potential agent for photodynamic therapy owing to its nucleic acid interactions and photobiological or photochemical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

The on scene command and control system (OSC2) : an integrated incident command system (ICS) forms-database management system and oil spill trajectory and fates model

International Nuclear Information System (INIS)

Anderson, E.; Galagan, C.; Howlett, E.

1998-01-01

The On Scene Command and Control (OSC 2 ) system is an oil spill modeling tool which was developed to combine Incident Command System (ICS) forms, an underlying database, an integrated geographical information system (GIS) and an oil spill trajectory and fate model. The first use of the prototype OSC 2 system was at a PREP drill conducted at the U.S. Coast Guard Marine Safety Office, San Diego, in April 1998. The goal of the drill was to simulate a real-time response over a 36-hour period using the Unified Command System. The simulated spill was the result of a collision between two vessels inside San Diego Bay that caused the release of 2,000 barrels of fuel oil. The hardware component of the system which was tested included three notebook computers, two laser printers, and a poster printer. The field test was a success but it was not a rigorous test of the system's capabilities. The map display was useful in quickly setting up the ICS divisions and groups and in deploying resources. 6 refs., 1 tab., 5 figs

Nickel, copper and cobalt coalescence in copper cliff converter slag

Directory of Open Access Journals (Sweden)

Wolf A.

2016-01-01

Full Text Available The aim of this investigation is to assess the effect of various additives on coalescence of nickel, copper and cobalt from slags generated during nickel extraction. The analyzed fluxes were silica and lime while examined reductants were pig iron, ferrosilicon and copper-silicon compound. Slag was settled at the different holding temperatures for various times in conditions that simulated the industrial environment. The newly formed matte and slag were characterized by their chemical composition and morphology. Silica flux generated higher partition coefficients for nickel and copper than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and corresponding partition coefficients than fluxes. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with some minute traces of magnetite as the secondary phase. Addition of 5 wt% of pig iron, ferrosilicon and copper-silicon alloys favored the formation of a metallized matte which increased Cu, Ni and Co recoveries. Addition of copper-silicon alloys with low silicon content was efficient in copper recovery but coalescence of the other metals was low. Slag treated with the ferrosilicon facilitated the highest cobalt recovery while copper-silicon alloys with silicon content above 10 wt% resulted in high coalescence of nickel and copper, 87 % and 72 % respectively.

Antwerp Copper Plates

DEFF Research Database (Denmark)

Wadum, Jørgen

1999-01-01

In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes.......In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes....

Assessing the potential roles of silicon and germanium phthalocyanines in planar heterojunction organic photovoltaic devices and how pentafluoro phenoxylation can enhance π-π interactions and device performance.

Science.gov (United States)

Lessard, Benoît H; White, Robin T; Al-Amar, Mohammad; Plint, Trevor; Castrucci, Jeffrey S; Josey, David S; Lu, Zheng-Hong; Bender, Timothy P

2015-03-11

In this study, we have assessed the potential application of dichloro silicon phthalocyanine (Cl2-SiPc) and dichloro germanium phthalocyanine (Cl2-GePc) in modern planar heterojunction organic photovoltaic (PHJ OPV) devices. We have determined that Cl2-SiPc can act as an electron donating material when paired with C60 and that Cl2-SiPc or Cl2-GePc can also act as an electron acceptor material when paired with pentacene. These two materials enabled the harvesting of triplet energy resulting from the singlet fission process in pentacene. However, contributions to the generation of photocurrent were observed for Cl2-SiPc with no evidence of photocurrent contribution from Cl2-GePc. The result of our initial assessment established the potential for the application of SiPc and GePc in PHJ OPV devices. Thereafter, bis(pentafluoro phenoxy) silicon phthalocyanine (F10-SiPc) and bis(pentafluoro phenoxy) germanium phthalocyanine (F10-GePc) were synthesized and characterized. During thermal processing, it was discovered that F10-SiPc and F10-GePc underwent a reaction forming small amounts of difluoro SiPc (F2-SiPc) and difluoro GePc (F2-GePc). This undesirable reaction could be circumvented for F10-SiPc but not for F10-GePc. Using single crystal X-ray diffraction, it was determined that F10-SiPc has significantly enhanced π-π interactions compared with that of Cl2-SiPc, which had little to none. Unoptimized PHJ OPV devices based on F10-SiPc were fabricated and directly compared to those constructed from Cl2-SiPc, and in all cases, PHJ OPV devices based on F10-SiPc had significantly improved device characteristics compared to Cl2-SiPc.

Charge carrier mobility in sulphonated and non-sulphonated Ni phthalocyanines: experiment and quantum chemical calculations

Czech Academy of Sciences Publication Activity Database

Šebera, Jakub; Nešpůrek, Stanislav; Kratochvílová, Irena; Záliš, Stanislav; Chaidogiannos, G.; Glezos, N.

2009-01-01

Roč. 72, č. 3 (2009), s. 385-395 ISSN 1434-6028 R&D Projects: GA MŠk OC 139; GA MŠk OC 137; GA AV ČR KAN401770651; GA AV ČR KAN200100801; GA ČR GA203/08/1594; GA MŠk OC 138 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40500505; CEZ:AV0Z10100520 Keywords : Ni Phthalocyanines * chemical calculations * polymers Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.466, year: 2009

Speciation and leachability of copper in mine tailings from porphyry copper mining

DEFF Research Database (Denmark)

Hansen, Henrik K.; Yianatos, Juan B; Ottosen, Lisbeth M.

2005-01-01

Mine tailing from the El Teniente-Codelco copper mine situated in VI Region of Chile was analysed in order to evaluate the mobility and speciation of copper in the solid material. Mine tailing was sampled after the rougher flotation circuits, and the copper content was measured to 1150mgkg^-^1 dry...... matter. This tailing was segmented into fractions of different size intervals: 0-38, 38-45, 45-53, 53-75, 75-106, 106-150, 150-212, and >212@mm, respectively. Copper content determination, sequential chemical extraction, and desorption experiments were carried out for each size interval in order...... to evaluate the speciation of copper. It was found that the particles of smallest size contained 50-60% weak acid leachable copper, whereas only 32% of the copper found in largest particles could be leached in weak acid. Copper oxides and carbonates were the dominating species in the smaller particles...

Tribological properties of copper-based composites with copper coated NbSe2 and CNT

International Nuclear Information System (INIS)

Chen, Beibei; Yang, Jin; Zhang, Qing; Huang, Hong; Li, Hongping; Tang, Hua; Li, Changsheng

2015-01-01

Graphical abstract: Morphology of copper coated NbSe 2 and CNT; friction coefficient and wear rate of copper-based composites. - Highlights: • NbSe 2 and CNT were coated with copper layers by the means of electroless plating. • The mechanical and tribological properties of copper composites were studied. • The enhancement mechanisms of copper coated NbSe 2 and CNT were proposed. • Copper–copper coated (12 wt.%NbSe 2 –3 wt.%CNT) composite had the best wear resistance. - Abstract: Copper-based composites with copper coated NbSe 2 and/or CNT were fabricated by the powder metallurgy technique. The morphology and phase composition of copper coated NbSe 2 and carbon nanotube (CNT) were observed using high solution transmission electronic microscope (HRTEM), scanning electronic microscope (SEM equipped with EDS) and X-ray diffraction (XRD). The density, hardness, and bending strength of as-prepared copper-based composites were measured, and their tribological properties were investigated using UMT-2 tester. Results indicated that all copper-based composites showed decreased density and bending strength, but increased hardness in comparison with copper matrix. Besides, the incorporation of copper coated NbSe 2 improved the friction-reducing and anti-wear properties of copper matrix. Addition of copper coated CNT greatly enhanced the mechanical and tribological properties. In particular, when the content of copper coated CNT was 3 wt.%, the corresponding composite exhibited the best tribological properties. This was because NbSe 2 was distributed chaotically in matrix, which greatly improved the friction-reducing property of copper, while CNT with superior mechanical strength enhanced the wear resistance by increasing the load-carrying capacity. More importantly, copper layers coated on NbSe 2 and CNT favored the good interfacial combination between fillers and copper matrix showing beneficial effect for the stresses transferring from matrix to fillers

Copper and Anesthesia: Clinical Relevance and Management of Copper Related Disorders

OpenAIRE

Langley, Adrian; Dameron, Charles T.

2013-01-01

Recent research has implicated abnormal copper homeostasis in the underlying pathophysiology of several clinically important disorders, some of which may be encountered by the anesthetist in daily clinical practice. The purpose of this narrative review is to summarize the physiology and pharmacology of copper, the clinical implications of abnormal copper metabolism, and the subsequent influence of altered copper homeostasis on anesthetic management.

Industrial Tests to Modify Molten Copper Slag for Improvement of Copper Recovery

Science.gov (United States)

Guo, Zhengqi; Zhu, Deqing; Pan, Jian; Zhang, Feng; Yang, Congcong

2018-04-01

In this article, to improve the recovery of copper from copper slag by flotation process, industrial tests of the modification process involving addition of a composite additive into molten copper slag were conducted, and the modified slag was subjected to the flotation process to confirm the modification effect. The phase evolution of the slag in the modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that more copper was transformed and enriched in copper sulfide phases. The magnetite content in the modified slag decreased, and that of "FeO" increased correspondingly, leading to a better fluidity of the molten slag, which improved the aggregation and growth of fine particles of the copper sulfide minerals. Closed-circuit flotation tests of the original and modified slags were conducted, and the results show that the copper recovery increased obviously from 69.15% to 73.38%, and the copper grade of concentrates was elevated slightly from 20.24% to 21.69%, further confirming that the industrial tests of the modification process were successful. Hence, the modification process has a bright future in industrial applications for enhancing the recovery of copper from the copper slag.

Functionalization of multi-walled carbon nanotubes with iron phthalocyanine via a liquid chemical reaction for oxygen reduction in alkaline media

Science.gov (United States)

Yan, Xiaomei; Xu, Xiao; Liu, Qin; Guo, Jia; Kang, Longtian; Yao, Jiannian

2018-06-01

Iron single-atom catalyst in form of iron-nitrogen-carbon structure possesses the excellent catalytic activity in various chemical reactions. However, exploring a sustainable and stable single-atom metal catalyst still faces a great challenge due to low yield and complicated synthesis. Here, we report a functional multi-wall carbon nanotubes modified with iron phthalocyanine molecules via a liquid chemical reaction and realize the performance of similar single-atom catalysis for oxygen reduction reaction. A serial of characterizations strongly imply the structure change of iron phthalocyanine molecule and its close recombination with multi-wall carbon nanotubes, which are in favor of ORR catalysis. Compared to commercial platinum-carbon catalyst, composites exhibit superior activity for oxygen reduction reaction with higher half-wave potential (0.86 V), lower Tafel slope (38 mV dec-1), higher limiting current density and excellent electrochemical stability. The corresponding Zinc-air battery also presents higher maximum power density and discharge stability. Therefore, these findings provide a facile route to synthesize a highly efficient non-precious metal carbon-based catalyst.

Two dimensional self-assembly zinc porphyrin and zinc phthalocyanine heterojunctions with record high power conversion efficiencies

Science.gov (United States)

Yu, Junting; Jiang, Zhou; Hao, Yifan; Zhu, Qianhong; Zhao, Mingliang; Jiang, Xue; Zhao, Jijun

2018-06-01

Compared to inorganic solar cells, the power conversion efficiencies (PCEs) of organic solar cells are much lower, but they are compensated by many merits such as lower cost, less weight, and tunable structures, making them prospective for further applications. Porphyrin and phthalocyanine are the two most significant materials for organic solar cells due to their strong light-absorbing properties and semiconductor characteristics. However, there is little research on the 2D heterojunction solar cells based on these two materials, meanwhile the PCEs of them are still low. Here we have self-assembled several 2D zinc porphyrins (ZnPors) and performed first-principles simulation to demonstrate their good stability, suitable light harvesting, and high charge carrier mobility. By perfectly matching lattice constants and molecular energy levels between those 2D ZnPors and our previous proposed zinc phthalocyanines (ZnPcs), 11 type-II organic heterojunctions are constructed to further improve their charge separation capability. Those advantages endow 2D ZnPors and ZnPcs appreciable PCEs for solar cells. Among them, the theoretical PCE of 2D ZnPors/ZnPcs heterojunctions achieves as high as 19.84%, which exceeds all reported organic solar cells, and even approaches the PCEs of inorganic solar cells. These results indicate that our 2D ZnPors and 2D ZnPcs are good candidate materials for future organic solar cells.

Photodynamic antimicrobial chemotherapy using zinc phthalocyanine derivatives in treatment of bacterial skin infection

Science.gov (United States)

Chen, Zhuo; Zhang, Yaxin; Wang, Dong; Li, Linsen; Zhou, Shanyong; Huang, Joy H.; Chen, Jincan; Hu, Ping; Huang, Mingdong

2016-01-01

Photodynamic antimicrobial chemotherapy (PACT) is an effective method for killing bacterial cells in view of the increasing problem of multiantibiotic resistance. We herein reported the PACT effect on bacteria involved in skin infections using a zinc phthalocyanine derivative, pentalysine β-carbonylphthalocyanine zinc (ZnPc-Lys). Compared with its anionic ZnPc counterpart, ZnPc-Lys showed an enhanced antibacterial efficacy in vitro and in an animal model of localized infection. Meanwhile, ZnPc-Lys was observed to significantly reduce the wound skin blood flow during wound healing, indicating an anti-inflammation activity. This study provides new insight on the mechanisms of PACT in bacterial skin infection.

77 FR 21769 - Certain New Chemicals; Receipt and Status Information

Science.gov (United States)

2012-04-11

... marketing exemption (TME), and to publish in the Federal Register periodic status reports on the new... marketing'' purposes, which is referred to as a test marketing exemption, or TME. For more information about... sulfonated, hydrogenated rosin and copper phthalocyanine with mixed chlorides. P-12-0207 02/29/2012 05/28...

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences; Volume 122; Issue 6. Synthesis and aggregation study of optically active tetra--[()-2-octanyloxy]-substituted copper and nickel phthalocyanines. Fang-Di Cong Gui Gao Jian-Xin Li Guo-Qing Huang Zhen Wei Feng-Yang Yu Xi-Guang Du Ke-Zhi Xing. Full Papers Volume ...

Power losses in bilayer inverted small molecule organic solar cells

KAUST Repository

Trinh, Cong; Bakke, Jonathan R.; Brennan, Thomas P.; Bent, Stacey F.; Navarro, Francisco; Bartynski, Andrew; Thompson, Mark E.

2012-01-01

Inverted bilayer organic solar cells using copper phthalocyanine (CuPc) as a donor and C60 as an acceptor with the structure: glass/indium tin oxide (ITO)/ZnO/C60/CuPc/MoO3/Al, in which the zinc oxide (ZnO) was deposited by atomic layer deposition

Copper nitrate redispersion to arrive at highly active silica-supported copper catalysts

NARCIS (Netherlands)

Munnik, P.|info:eu-repo/dai/nl/328228524; Wolters, M.|info:eu-repo/dai/nl/304829560; Gabrielsson, A.; Pollington, S.D.; Headdock, G.; Bitter, J.H.|info:eu-repo/dai/nl/160581435; de Jongh, P.E.|info:eu-repo/dai/nl/186125372; de Jong, K.P.|info:eu-repo/dai/nl/06885580X

2011-01-01

In order to obtain copper catalysts with high dispersions at high copper loadings, the gas flow rate and gas composition was varied during calcination of silica gel impregnated with copper nitrate to a loading of 18 wt % of copper. Analysis by X-ray diffraction (XRD), N2O chemisorption, and

Copper economy in Chlamydomonas: Prioritized allocation and reallocation of copper to respiration vs. photosynthesis

Science.gov (United States)

Kropat, Janette; Gallaher, Sean D.; Urzica, Eugen I.; Nakamoto, Stacie S.; Strenkert, Daniela; Tottey, Stephen; Mason, Andrew Z.; Merchant, Sabeeha S.

2015-01-01

Inorganic elements, although required only in trace amounts, permit life and primary productivity because of their functions in catalysis. Every organism has a minimal requirement of each metal based on the intracellular abundance of proteins that use inorganic cofactors, but elemental sparing mechanisms can reduce this quota. A well-studied copper-sparing mechanism that operates in microalgae faced with copper deficiency is the replacement of the abundant copper protein plastocyanin with a heme-containing substitute, cytochrome (Cyt) c6. This switch, which is dependent on a copper-sensing transcription factor, copper response regulator 1 (CRR1), dramatically reduces the copper quota. We show here that in a situation of marginal copper availability, copper is preferentially allocated from plastocyanin, whose function is dispensable, to other more critical copper-dependent enzymes like Cyt oxidase and a ferroxidase. In the absence of an extracellular source, copper allocation to Cyt oxidase includes CRR1-dependent proteolysis of plastocyanin and quantitative recycling of the copper cofactor from plastocyanin to Cyt oxidase. Transcriptome profiling identifies a gene encoding a Zn-metalloprotease, as a candidate effecting copper recycling. One reason for the retention of genes encoding both plastocyanin and Cyt c6 in algal and cyanobacterial genomes might be because plastocyanin provides a competitive advantage in copper-depleted environments as a ready source of copper. PMID:25646490

Canine Copper-Associated Hepatitis

NARCIS (Netherlands)

Dirksen, Karen; Fieten, Hille

2017-01-01

Copper-associated hepatitis is recognized with increasing frequency in dogs. The disease is characterized by centrolobular hepatic copper accumulation, leading to hepatitis and eventually cirrhosis. The only way to establish the diagnosis is by histologic assessment of copper distribution and copper

Negative differential resistance in nickel octabutoxy phthalocyanine and nickel octabutoxy phthalocyanine/graphene oxide ultrathin films

Science.gov (United States)

Sarkar, Arup; Suresh, K. A.

2018-04-01

We find negative differential resistance (NDR) at room temperature in ultrathin films of nickel (II) 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine [NiPc(OBu)8] deposited on highly ordered pyrolytic graphite (HOPG) substrate [NiPc(OBu)8/HOPG] and NiPc(OBu)8 on graphene oxide (GO) deposited on HOPG [NiPc(OBu)8/GO/HOPG]. For the NiPc(OBu)8/HOPG system, NiPc(OBu)8 was transferred four times onto HOPG by the Langmuir-Blodgett (LB) technique. We have prepared a stable Langmuir monolayer of amphiphilic GO at the air-water interface and transferred it onto HOPG by the LB technique. Further, the monolayer of NiPc(OBu)8 was transferred four times for good coverage on GO to obtain the NiPc(OBu)8/GO/HOPG system. The current-voltage characteristics were carried out using a current sensing atomic force microscope (CSAFM) with a platinum (Pt) tip that forms Pt/NiPc(OBu)8/HOPG and Pt/NiPc(OBu)8/GO/HOPG junctions. The CSAFM, UV-visible spectroscopy, and cyclic voltammetry studies show that the NDR effect occurs due to molecular resonant tunneling. In the Pt/NiPc(OBu)8/GO/HOPG junction, we find that due to the presence of GO, the features of NDR become more prominent. Also, GO causes a shift in NDR voltage towards a lower value in the negative bias direction. We attribute this behavior to the role of GO in injecting holes into the NiPc(OBu)8 film.

Earth's copper resources estimated from tectonic diffusion of porphyry copper deposits

Science.gov (United States)

Kesler, Stephen E.; Wilkinson, Bruce H.

2008-03-01

Improved estimates of global mineral endowments are relevantto issues ranging from strategic planning to global geochemicalcycling. We have used a time-space model for the tectonic migrationof porphyry copper deposits vertically through the crust tocalculate Earth's endowment of copper in mineral deposits. Themodel relies only on knowledge of numbers and ages of porphyrycopper deposits, Earth's most widespread and important sourceof copper, in order to estimate numbers of eroded and preserveddeposits in the crust. Model results indicate that 125,895 porphyrycopper deposits were formed during Phanerozoic time, that only47,789 of these remain at various crustal depths, and that thesecontain 1.7 x 1011 tonnes (t) of copper. Assuming that othertypes of copper deposits behave similarly in the crust and haveabundances proportional to their current global production yieldsan estimate of 3 x 1011 t for total global copper resourcesat all levels in Earth's crust. Thus, 0.25% of the copper inthe crust has been concentrated into deposits through Phanerozoictime, and about two-thirds of this has been recycled by upliftand erosion. The amount of copper in deposits above 3.3 km,a likely limit of future mining, could supply current worldmine production for 5500 yr, thus quantifying the highly unusualand nonrenewable nature of mineral deposits.

Structure-Stability Relationships of Phthalocyanine Copper Complexes

Directory of Open Access Journals (Sweden)

G. P. Shaposhnikov

2000-06-01

Full Text Available The influence of NO2, Br, and COOH function substituents in various positions of Cu(IIPc on the reactivity of the latter concerning the dissociation of the metal - nitrogen bonds in proton donor solvents is discussed.

Stage specific effects of soluble copper and copper oxide nanoparticles during sea urchin embryo development and their relation to intracellular copper uptake.

Science.gov (United States)

Torres-Duarte, Cristina; Ramos-Torres, Karla M; Rahimoff, René; Cherr, Gary N

2017-08-01

The effects of exposure to either soluble copper (copper sulfate) or copper oxide nanoparticles (nano-CuO) during specific early developmental stages of sea urchin embryos were analyzed. Soluble copper caused significant malformations in embryos (skeletal malformations, delayed development or gut malformations) when present at any given stage, while cleavage stage was the most sensitive to nano-CuO exposure causing skeletal malformations and decreased total antioxidant capacity. The stage specificity was linked to higher endocytic activity during the first hours of development that leads to higher accumulation of copper in specific cells critical for development. Results indicate that nano-CuO results in higher accumulation of copper inside of embryos and this intracellular copper is more persistent as compared to soluble copper. The possible implications later in development are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Genome Sequences of Two Copper-Resistant Escherichia coli Strains Isolated from Copper-Fed Pigs

DEFF Research Database (Denmark)

Lüthje, Freja L.; Hasman, Henrik; Aarestrup, Frank Møller

2014-01-01

The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances.......The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances....

Enhanced photodynamic efficacy of zinc phthalocyanine by conjugating to heptalysine.

Science.gov (United States)

Li, Linsen; Luo, Zhipu; Chen, Zhuo; Chen, Jincan; Zhou, Shanyong; Xu, Peng; Hu, Ping; Wang, Jundong; Chen, Naisheng; Huang, Jinling; Huang, Mingdong

2012-11-21

Zinc phthalocyanine (ZnPc) is a promising photosensitizer for photodynamic therapy, but faces some challenges: ZnPc is insoluble in water and thus requires either special formulation of ZnPc by, e.g., liposome or Cremophor EL, or chemical modification of Pc ring to enhance its bioavailability and photodynamic efficacy. Here, we conjugated monosubstituted ZnPc-COOH with a series of oligolysine moieties with different numbers of lysine residues (ZnPc-(Lys)(n) (n = 1, 3, 5, 7, 9) to improve the water solubility of the ZnPc conjugates. We measured the photosensitizing efficacies and the cellular uptakes of this series of conjugates on a normal and a cancerous cell line. In addition, we developed a sensitive in situ method to distinguish the difference in photodynamic efficacy among conjugates. Our results showed that ZnPc-(Lys)(7) has the highest photodynamic efficacy compared to the other conjugates investigated.

Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

NARCIS (Netherlands)

Berg, van den G.J.; de Goeij, J.J.M.; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendriks, H.F.J.

1991-01-01

Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (<1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

NARCIS (Netherlands)

Berg, G.J. van den; Goeij, J.J.M. de; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendruiks, H.F.J.

1991-01-01

Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (< 1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

Studies on phase transformation and molecular orientation in nanostructured zinc phthalocyanine thin films annealed at different temperatures

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Avijit; Biswas, Bipul; Majumder, Manisree; Sanyal, Manik Kumar; Mallik, Biswanath, E-mail: spbm@iacs.res.in

2012-08-31

Studies on the electronic and optical properties of thin films of organometallic compounds such as phthalocyanine are very important for the development of devices based on these compounds. The nucleation and grain growth mechanism play an important role for the final electronic as well as optoelectronic properties of the organic and organometallic thin films. The present article deals with the change in the film morphology, grain orientation of nanocrystallites and optical properties of zinc phthalocyanines (ZnPc) thin films as a function of the post deposition annealing temperature. The effect of annealing temperature on the optical and structural property of vacuum evaporated ZnPc thin films deposited at room temperature (30 Degree-Sign C) on quartz glass and Si(100) substrates has been investigated. The thin films have been characterized by the UV-vis optical absorption spectra, X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy. From the studies of UV-vis absorption spectra and XRD data, a metastable {alpha} to {beta}-phase transformation has been observed when the thin films were annealed at a temperature greater than about 250 Degree-Sign C. The FESEM images have shown the particlelike structure at room temperature and the structure became rodlike when the films were annealed at high temperatures. TEM image of ZnPc film dissolved in ethanol has shown spectacular rod-shaped crystallites. High resolution transmission electron microscopy image of a single nanorod has shown beautiful 'honey-comb' like structure. Particle size and root mean square roughness were calculated from AFM images. The changes in band gap energy with increase in annealing temperature have been evaluated. - Highlights: Black-Right-Pointing-Pointer Morphology and orientation of grains in zinc phthalocyanine (ZnPc) thin films. Black

Annual Copper Mountain Conferences on Multigrid and Iterative Methods, Copper Mountain, Colorado

International Nuclear Information System (INIS)

McCormick, Stephen F.

2016-01-01

This project supported the Copper Mountain Conference on Multigrid and Iterative Methods, held from 2007 to 2015, at Copper Mountain, Colorado. The subject of the Copper Mountain Conference Series alternated between Multigrid Methods in odd-numbered years and Iterative Methods in even-numbered years. Begun in 1983, the Series represents an important forum for the exchange of ideas in these two closely related fields. This report describes the Copper Mountain Conference on Multigrid and Iterative Methods, 2007-2015. Information on the conference series is available at http://grandmaster.colorado.edu/~copper/

Annual Copper Mountain Conferences on Multigrid and Iterative Methods, Copper Mountain, Colorado

Energy Technology Data Exchange (ETDEWEB)

McCormick, Stephen F. [Front Range Scientific, Inc., Lake City, CO (United States)

2016-03-25

This project supported the Copper Mountain Conference on Multigrid and Iterative Methods, held from 2007 to 2015, at Copper Mountain, Colorado. The subject of the Copper Mountain Conference Series alternated between Multigrid Methods in odd-numbered years and Iterative Methods in even-numbered years. Begun in 1983, the Series represents an important forum for the exchange of ideas in these two closely related fields. This report describes the Copper Mountain Conference on Multigrid and Iterative Methods, 2007-2015. Information on the conference series is available at http://grandmaster.colorado.edu/~copper/.

Copper wire bonding

CERN Document Server

Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

2014-01-01

This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

Probing the Influence of the Conjugated Structure and Halogen Atoms of Poly-Iron-Phthalocyanine on the Oxygen Reduction Reaction by X-ray Absorption Spectroscopy and Density Functional Theory

International Nuclear Information System (INIS)

Peng, Yingxiang; Cui, Lufang; Yang, Shifeng; Fu, Jingjing; Zheng, Lirong; Liao, Yi; Li, Kai; Zuo, Xia; Xia, Dingguo

2015-01-01

Metal-phthalocyanine (MPc) macrocyclic catalysts have been perceived as promising alternatives to Pt and Pt-based catalysts for the oxygen reduction reaction (ORR). However, the effect of different MPc molecular structures on the ORR has rarely been reported in depth. Herein, iron-phthalocyanine polymers (poly-FePcs) and multi-walled carbon nanotubes (MWCNTs) composites with different structures were synthesized using microwave method. The relationship between their molecular structure and electrocatalytic activity was fully revealed by density functional theory (DFT) and X-ray fine absorption spectroscopy (XAFS). DFT calculations revealed that the introduction of halogen atoms can increase the ion potential (IP) and the dioxo-binding energy () of the poly-FePcs. Meanwhile, their conjugated structure not only facilitates electronic transmission, but also significantly increases . XAFS analysis indicated that the poly-FePc/MWCNTs composites had a square planar structure and a smaller of phthalocyanine ring (Fe-N 4 structure) skeleton structure radius when a larger conjugated structure or introduced halogen atoms was present. The experimental results suggest that the these changes in properties arising from the different structures of the MPc macrocyclic compounds led to a huge effect on their ORR electrochemical activities, and provide a guide to obtaining promising electrochemical catalysts

Nearly 60% Copper Rod & Wire Companies Neutral about Future Copper Price

Institute of Scientific and Technical Information of China (English)

2012-01-01

<正>How about the trend of copper price recently? According to the survey result of Shanghai Metals Market, amongst 21 domestic copper rod & wire companies, 57% of the companies are neutral about the future copper price, while 14% and 19% of the companies consider that

Sandwich-cell-type bulk-heterojunction organic solar cells utilizing liquid crystalline phthalocyanine

Science.gov (United States)

Nakata, Yuya; Usui, Toshiki; Nishikawa, Yuki; Nekelson, Fabien; Shimizu, Yo; Fujii, Akihiko; Ozaki, Masanori

2018-03-01

Sandwich-cell-type bulk-heterojunction organic solar cells utilizing the liquid crystalline phthalocyanine, 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH2), have been fabricated and their photovoltaic properties have been studied. The short-circuit current (J SC) and power conversion efficiency (PCE) depended on the blend ratio of donor and acceptor molecules, and the maximum performance, such as J SC of 3.4 mA/cm2 and PCE of 0.67%, was demonstrated, when the blend ratio of the acceptor was 10 mol %. The photovoltaic properties were discussed by taking the relationship between the column axis direction of C6PcH2 and the carrier mobility in the active layer into consideration.

Immobilization of ruthenium phthalocyanine on silica-coated multi-wall partially oriented carbon nanotubes: Electrochemical detection of fenitrothion pesticide

Energy Technology Data Exchange (ETDEWEB)

Canevari, Thiago C., E-mail: tccanevari@gmail.com [Engineering School, Mackenzie Presbyterian University, 01302-907 São Paulo, SP (Brazil); Prado, Thiago M.; Cincotto, Fernando H.; Machado, Sergio A.S. [Institute of Chemistry, State University of São Paulo, P.O. Box 780, 13560-970 São Carlos, SP (Brazil)

2016-04-15

Highlights: • Hybrid material, SiO{sub 2}/MWCNTs containing ruthenium phthalocyanine (RuPc) synthesized in situ. • Silica containing multi-walled carbon nanotube partially oriented. • Determination of pesticide fenitrothion in orange juice. - Abstract: This paper reports on the determination of the pesticide fenitrothion using a glassy carbon electrode modified with silica-coated, multi-walled, partially oriented carbon nanotubes, SiO{sub 2}/MWCNTs, containing ruthenium phthalocyanine (RuPc) synthesized in situ. The hybrid SiO{sub 2}/MWCNTs/RuPc material was characterized by UV–vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and differential pulse voltammetry. The modified electrode showed well-defined peaks in the presence of fenitrothion in acetate buffer, pH 4.5, with a sensitivity of 0.0822 μA μM{sup −1} mm{sup −2} and a detection limit of 0.45 ppm. Notably, the modified SiO{sub 2}/MWCNTs/RuPc electrodes with did not suffer from significant influences in the presence of other organophosphorus pesticides during the determination of the fenitrothion pesticide. Moreover, this modified electrode showed excellent performance in the determination of fenitrothion in orange juice.

Thin film formation at the air-water interface and on solid substrates of soluble axial substituted cis-bis-decanoate tin phthalocyanine

Energy Technology Data Exchange (ETDEWEB)

Campos-Teran, Jose, E-mail: jcampos@correo.cua.uam.mx [Departamento de Procesos y Tecnologia, DCNI, Universidad Autonoma Metropolitana-Cuajimalpa, Artificios 40-sexto piso, Col. Hidalgo, D. F., 001120 (Mexico); Garza, Cristina [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, P. O. Box 20-364, D. F., 01000 (Mexico); Beltran, Hiram I. [Departamento de Ciencias Naturales, DCNI, Universidad Autonoma Metropolitana-Cuajimalpa, Artificios 40-sexto piso, Col. Hidalgo, D. F., 001120 (Mexico); Castillo, Rolando [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, P. O. Box 20-364, D. F., 01000 (Mexico)

2012-01-01

Herein we study thin films of a recent kind of soluble axial substituted cis-bis-decanoate-tin{sup IV} phthalocyanine (PcSn10) at the air/water interface, which were compressed isothermally and observed with Brewster Angle Microscopy. The air/water interfacial behavior of the films suggests that there are strong interactions among the PcSn10 molecules, which produces multilayers and 3D self-assemblies that prevent the formation of a Langmuir monolayer. Langmuir-Blodgett deposits of these films on both mica (negatively charged) and mild steel (positively charged) surfaces were developed. Information about the morphology of the film was obtained by using atomic force microscopy. We found structural differences in the PcSn10 thin films deposited on both substrates, suggesting that a combination of {pi}-{pi}, {sigma}-{pi} and Van der Waals interactions are the leading factors for the deposition, and consequently, for the control of supramolecular order. Our findings provide insights in the design of phthalocyanine molecules for the development of highly ordered and reproducible thin films.

Thin film formation at the air–water interface and on solid substrates of soluble axial substituted cis-bis-decanoate tin phthalocyanine

International Nuclear Information System (INIS)

Campos-Terán, José; Garza, Cristina; Beltrán, Hiram I.; Castillo, Rolando

2012-01-01

Herein we study thin films of a recent kind of soluble axial substituted cis-bis-decanoate-tin IV phthalocyanine (PcSn10) at the air/water interface, which were compressed isothermally and observed with Brewster Angle Microscopy. The air/water interfacial behavior of the films suggests that there are strong interactions among the PcSn10 molecules, which produces multilayers and 3D self-assemblies that prevent the formation of a Langmuir monolayer. Langmuir–Blodgett deposits of these films on both mica (negatively charged) and mild steel (positively charged) surfaces were developed. Information about the morphology of the film was obtained by using atomic force microscopy. We found structural differences in the PcSn10 thin films deposited on both substrates, suggesting that a combination of π–π, σ–π and Van der Waals interactions are the leading factors for the deposition, and consequently, for the control of supramolecular order. Our findings provide insights in the design of phthalocyanine molecules for the development of highly ordered and reproducible thin films.

Immunotoxicity of copper nanoparticle and copper sulfate in a common Indian earthworm.

Science.gov (United States)

Gautam, Arunodaya; Ray, Abhishek; Mukherjee, Soumalya; Das, Santanu; Pal, Kunal; Das, Subhadeep; Karmakar, Parimal; Ray, Mitali; Ray, Sajal

2018-02-01

Copper oxide nanoparticles and copper sulfate are established contaminants of water and soil. Metaphire posthuma is a common variety of earthworm distributed in moist soil of Indian subcontinent. Comparative toxicity of copper nanoparticles and copper sulfate were investigated with reference to selected immune associated parameters of earthworm. Total count, phagocytic response, generation of cytotoxic molecules (superoxide anion, nitric oxide), activities of enzymes like phenoloxidase, superoxide dismutase, catalase, acid phosphatase, alkaline phosphatase and total protein of coelomocytes were estimated under the exposures of 100, 500, 1000mg of copper oxide nanoparticles and copper sulfate per kg of soil for 7 and 14 d. A significant decrease in the total coelomocyte count were recorded with maximum depletion as 15.45 ± 2.2 and 12.5 ± 2 × 10 4 cells/ml under the treatment of 1000mg/kg of copper nanoparticles and copper sulfate for 14 d respectively. A significant decrease in generation of nitric oxide and activity of phenoloxidase were recorded upon exposure of both toxins for 7 and 14 d indicating possible decline in cytotoxic status of the organism. A maximum inhibition of superoxide dismutase activity was recorded as 0.083 ± 0.0039 and 0.055 ± 0.0057 unit/mg protein/minute against 1000mg/kg of copper nanoparticles and copper sulfate treatment for 14 d respectively. Activities of catalase and alkaline phosphatase were inhibited by all experimental concentrations of both toxins in the coelomocytes of earthworm. These toxins were recorded to be modifiers of the major immune associated parameters of M. posthuma. Unrestricted contamination of soil by sulfate and oxide nanoparticles of copper may lead to an undesirable shift in the innate immunological status of earthworm leading to a condition of immune compromisation and shrinkage in population density of this species in its natural habitat. This article is the first time report of immunological toxicity of

Biliary copper excretion by hepatocyte lysosomes in the rat. Major excretory pathway in experimental copper overload

International Nuclear Information System (INIS)

Gross, J.B. Jr.; Myers, B.M.; Kost, L.J.; Kuntz, S.M.; LaRusso, N.F.

1989-01-01

We investigated the hypothesis that lysosomes are the main source of biliary copper in conditions of hepatic copper overload. We used a rat model of oral copper loading and studied the relationship between the biliary output of copper and lysosomal hydrolases. Male Sprague-Dawley rats were given tap water with or without 0.125% copper acetate for up to 36 wk. Copper loading produced a 23-fold increase in the hepatic copper concentration and a 30-65% increase in hepatic lysosomal enzyme activity. Acid phosphatase histochemistry showed that copper-loaded livers contained an increased number of hepatocyte lysosomes; increased copper concentration of these organelles was confirmed directly by both x ray microanalysis and tissue fractionation. The copper-loaded rats showed a 16-fold increase in biliary copper output and a 50-300% increase in biliary lysosomal enzyme output. In the basal state, excretory profiles over time were similar for biliary outputs of lysosomal enzymes and copper in the copper-loaded animals but not in controls. After pharmacologic stimulation of lysosomal exocytosis, biliary outputs of copper and lysosomal hydrolases in the copper-loaded animals remained coupled: injection of colchicine or vinblastine produced an acute rise in the biliary output of both lysosomal enzymes and copper to 150-250% of baseline rates. After these same drugs, control animals showed only the expected increase in lysosomal enzyme output without a corresponding increase in copper output. We conclude that the hepatocyte responds to an increased copper load by sequestering excess copper in an increased number of lysosomes that then empty their contents directly into bile. The results provide direct evidence that exocytosis of lysosomal contents into biliary canaliculi is the major mechanism for biliary copper excretion in hepatic copper overload

Underwater explosive compaction-sintering of tungsten-copper coating on a copper surface

Science.gov (United States)

Chen, Xiang; Li, Xiaojie; Yan, Honghao; Wang, Xiaohong; Chen, Saiwei

2018-01-01

This study investigated underwater explosive compaction-sintering for coating a high-density tungsten-copper composite on a copper surface. First, 50% W-50% Cu tungsten-copper composite powder was prepared by mechanical alloying. The composite powder was pre-compacted and sintered by hydrogen. Underwater explosive compaction was carried out. Finally, a high-density tungsten-copper coating was obtained by diffusion sintering of the specimen after explosive compaction. A simulation of the underwater explosive compaction process showed that the peak value of the pressure in the coating was between 3.0 and 4.8 GPa. The hardness values of the tungsten-copper layer and the copper substrate were in the range of 87-133 and 49 HV, respectively. The bonding strength between the coating and the substrate was approximately 100-105 MPa.

Team OSCE: A Teaching Modality for Promotion of Multidisciplinary Work in Mental Health Settings.

Science.gov (United States)

Sharma, Manoj Kumar; Chandra, Prabha S; Chaturvedi, Santosh K

2015-01-01

The objective structured clinical examination has been in use both as an assessment and a teaching modality within the mental health profession. It focuses on individual skill enhancement, the inter-professional understanding of role obligation is helpful in promoting competence as a team as well as role of other team members. The Team OSCE (TOSCE) is an effective way in promoting inter-professional learning. The present work assesses the trainee experience with TOSCE and its utility in clinical care. Twenty-two mental health trainees (17 male and 5 female from psychiatry, clinical psychology and psychiatric social work) got exposure to weekly OSCAF training as well as 2-3 Team OSCAFS on various aspects of clinical work as a part of their clinical training for 3 months. Rating from the trainees were taken on TOSCE feedback checklist. TOSCE was helpful in promoting the understanding role of other team members; shared decision-making, problem-solving, handling unexpected events, giving feedback and closure. The TOSCE may be introduced as a way to work on clinical performance, shared decision-making and inter-professional understanding.

Sulfidation treatment of copper-containing plating sludge towards copper resource recovery.

Science.gov (United States)

Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

2006-11-02

The present study is concerned with the sulfidation treatment of copper-containing plating sludge towards copper resource recovery by flotation of copper sulfide from treated sludge. The sulfidation treatment was carried out by contacting simulated or real copper plating sludge with Na(2)S solution for a period of 5 min to 24 h. The initial molar ratio of S(2-) to Cu(2+) (S(2-) to Me(2+) in the case of real sludge) was adjusted to 1.00, 1.25 or 1.50, while the solid to liquid ratio was set at 1:50. As a result, it was found that copper compounds were converted to various copper sulfides within the first 5 min. In the case of simulated copper sludge, CuS was identified as the main sulfidation product at the molar ratio of S(2-) to Cu(2+) of 1.00, while Cu(7)S(4) (Roxbyite) was mainly found at the molar ratios of S(2-) to Cu(2+) of 1.50 and 1.25. Based on the measurements of oxidation-reduction potential, the formation of either CuS or Cu(7)S(4) at different S(2-) to Cu(2+) molar ratios was attributed to the changes in the oxidation-reduction potential. By contrast, in the case of sulfidation treatment of real copper sludge, CuS was predominantly formed, irrespective of S(2-) to Me(2+) molar ratio.

Critical review: Copper runoff from outdoor copper surfaces at atmospheric conditions.

Science.gov (United States)

Hedberg, Yolanda S; Hedberg, Jonas F; Herting, Gunilla; Goidanich, Sara; Odnevall Wallinder, Inger

2014-01-01

This review on copper runoff dispersed from unsheltered naturally patinated copper used for roofing and facades summarizes and discusses influencing factors, available literature, and predictive models, and the importance of fate and speciation for environmental risk assessment. Copper runoff from outdoor surfaces is predominantly governed by electrochemical and chemical reactions and is highly dependent on given exposure conditions (size, inclination, geometry, degree of sheltering, and orientation), surface parameters (age, patina composition, and thickness), and site-specific environmental conditions (gaseous pollutants, chlorides, rainfall characteristics (amount, intensity, pH), wind direction, temperature, time of wetness, season). The corrosion rate cannot be used to assess the runoff rate. The extent of released copper varies largely between different rain events and is related to dry and wet periods, dry deposition prior to the rain event and prevailing rain and patina characteristics. Interpretation and use of copper runoff data for environmental risk assessment and management need therefore to consider site-specific factors and focus on average data of long-term studies (several years). Risk assessments require furthermore that changes in copper speciation, bioavailability aspects, and potential irreversible retention on solid surfaces are considered, factors that determine the environmental fate of copper runoff from outdoor surfaces.

Copper hypersensitivity

DEFF Research Database (Denmark)

Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

2014-01-01

hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

A cytosolic copper storage protein provides a second level of copper tolerance in Streptomyces lividans.

Science.gov (United States)

Straw, Megan L; Chaplin, Amanda K; Hough, Michael A; Paps, Jordi; Bavro, Vassiliy N; Wilson, Michael T; Vijgenboom, Erik; Worrall, Jonathan A R

2018-01-24

Streptomyces lividans has a distinct dependence on the bioavailability of copper for its morphological development. A cytosolic copper resistance system is operative in S. lividans that serves to preclude deleterious copper levels. This system comprises of several CopZ-like copper chaperones and P 1 -type ATPases, predominantly under the transcriptional control of a metalloregulator from the copper sensitive operon repressor (CsoR) family. In the present study, we discover a new layer of cytosolic copper resistance in S. lividans that involves a protein belonging to the newly discovered family of copper storage proteins, which we have named Ccsp (cytosolic copper storage protein). From an evolutionary perspective, we find Ccsp homologues to be widespread in Bacteria and extend through into Archaea and Eukaryota. Under copper stress Ccsp is upregulated and consists of a homotetramer assembly capable of binding up to 80 cuprous ions (20 per protomer). X-ray crystallography reveals 18 cysteines, 3 histidines and 1 aspartate are involved in cuprous ion coordination. Loading of cuprous ions to Ccsp is a cooperative process with a Hill coefficient of 1.9 and a CopZ-like copper chaperone can transfer copper to Ccsp. A Δccsp mutant strain indicates that Ccsp is not required under initial copper stress in S. lividans, but as the CsoR/CopZ/ATPase efflux system becomes saturated, Ccsp facilitates a second level of copper tolerance.

Fabricating Copper Nanotubes by Electrodeposition

Science.gov (United States)

Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

2009-01-01

Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

Raman Identification of Pigments in Wall Paintings of the Colonial Period from Bolivian Churches in the Ruta De La Plata

Directory of Open Access Journals (Sweden)

Carlos Rúa

2018-03-01

Full Text Available Micro-Raman spectroscopy was used to analyze and identify pigments and determine the palette of color in wall paintings from four churches of the Colonial Period, in the Bolivian highlands. The ancient churches Santiago de Callapa, Curahuara de Carangas, NuestraSeñora de Copacabana de Andamarca and San José de Soracachi were constructed during the 17th and 18th centuries, around the important colonial Ruta de la Plata, between Potosí city and Arica harbor on the Pacific coast of South America. Most pigments used in the wall paintings correspond to inorganic minerals as well as to organic colorants. Fully chlorinated copper phthalocyanine (green, copper phthalocyanine (blue, β-naphthol (yellow and benzoimidazolone (red, were identified in the corresponding colored areas suggesting subsequent recent interventions or restorations. Ground layer materials were also characterized. The present results allow for discussion of the pictorial techniques used in the Andean highland during the colonial period and allow conservators and restorers to make important decisions regarding the type of intervention to perform in the case of these important historical and patrimonial monuments.

Surface characteristics, copper release, and toxicity of nano- and micrometer-sized copper and copper(II) oxide particles: a cross-disciplinary study.

OpenAIRE

Midander, Klara; Cronholm, Pontus; Karlsson, Hanna L.; Elihn, Karine; Moller, Lennart; Leygraf, Christofer; Wallinder, Inger Odnevall

2009-01-01

An interdisciplinary and multianalytical research effort is undertaken to assess the toxic aspects of thoroughly characterized nano- and micrometer-sized particles of oxidized metallic copper and copper(II) oxide in contact with cultivated lung cells, as well as copper release in relevant media. All particles, except micrometer-sized Cu, release more copper in serum-containing cell medium (supplemented Dulbecco's minimal essential medium) compared to identical exposures in phosphate-buffered ...

Electrochemical in-situ impregnation of wood using a copper nail as source for copper

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Block, Thomas; Nymark, Morten

2011-01-01

A new method for copper impregnation of wood in structures was suggested and tested in laboratory scale with specimen of new pine sapwood. A copper nail and a steel screw were placed in the wood, and an electric direct current field was applied, so the copper nail was anode and the screw...... was cathode. At the anode, copper ions were generated. The copper ions were transported into the wood by electromigration (movement of ions in an applied electric field) towards the cathode, and a volume between the two electrodes was thereby impregnated. Copper also moved to a lesser degree in the opposite...

Copper Leaching from Copper-ethanolamine Treated Wood: Comparison of Field Test Studies and Laboratory Standard Procedures

OpenAIRE

Nejc Thaler; Miha Humar

2014-01-01

Copper-based compounds are some of the most important biocides for the protection of wood in heavy duty applications. In the past, copper was combined with chromium compounds to reduce copper leaching, but a recent generation of copper-based preservatives uses ethanolamine as a fixative. To elucidate the leaching of copper biocides from wood, Norway spruce (Picea abies) wood was treated with a commercial copper-ethanolamine solution with two different copper concentrations (cCu = 0.125% and 0...

Copper metabolism: a multicompartmental model of copper kinetics in the rat

International Nuclear Information System (INIS)

Dunn, M.A.

1985-01-01

A qualitative multicompartmental model was developed that describes the whole-body kinetics of copper metabolism in the adult rat. The model was developed from radiocopper percent dose vs. time data measured over a three day period in plasma, liver, skin, skeletal muscle, bile and feces after the intravenous injection of 10 μg copper labeled with 64 Cu. Plasma radiocopper was separated into ceruloplasmin (Cp) and nonceruloplasmin (NCp) fractions. Liver cytosolic radiocopper was fractionated into void volume superoxide dismutase (SOD) containing and metallothionein fractions by gel filtration. Liver particulate fractions were isolated by differential centrifugation. The SAAM and CONSAM modeling programs were used to develop the model. The sizes of compartments, fractional rate constants and mass transfer rates between compartments were evaluated. The intracellular metabolism of copper was similar in hepatic and extrahepatic tissues being comprised of a faster turning over compartment (FTC) exchanging copper with NCp and a slower turning over compartment (STC) with input from Cp. Output from the STC was into the FTC. In the liver the STC was postulated to represent SOD copper which unlike the extrahepatic tissues received much of its input from the FTC. A small amount of biliary copper (9%) was postulated to return to plasma NCp by enterohepatic recycling. The model developed was contrasted and compared with two previous models of copper metabolism

Potential phytoextraction and phytostabilization of perennial peanut on copper-contaminated vineyard soils and copper mining waste.

Science.gov (United States)

Andreazza, Robson; Bortolon, Leandro; Pieniz, Simone; Giacometti, Marcelo; Roehrs, Dione D; Lambais, Mácio R; Camargo, Flávio A O

2011-12-01

This study sought to evaluate the potential of perennial peanut (Arachis pintoi) for copper phytoremediation in vineyard soils (Inceptisol and Mollisol) contaminated with copper and copper mining waste. Our results showed high phytomass production of perennial peanut in both vineyard soils. Macronutrient uptakes were not negatively affected by perennial peanut cultivated in all contaminated soils. Plants cultivated in Mollisol showed high copper concentrations in the roots and shoots of 475 and 52 mg kg(-1), respectively. Perennial peanut plants showed low translocation factor values for Cu, although these plants showed high bioaccumulation factor (BCF) for both vineyard soils, Inceptisol and Mollisol, with BCF values of 3.83 and 3.24, respectively, being characterized as a copper hyperaccumulator plant in these soils. Copper phytoextraction from Inceptisol soil was the highest for both roots and entire plant biomass, with more than 800 mg kg(-1) of copper in whole plant. The highest potential copper phytoextraction by perennial peanut was in Inceptisol soil with copper removal of 2,500 g ha(-1). Also, perennial peanut showed high potential for copper phytoremoval in copper mining waste and Mollisol with 1,700 and 1,500 g of copper per hectare, respectively. In addition, perennial peanuts characterized high potential for phytoextraction and phytostabilization of copper in vineyard soils and copper mining waste.

Heterojunction nanowires having high activity and stability for the reduction of oxygen: Formation by self-assembly of iron phthalocyanine with single walled carbon nanotubes (FePc/SWNTs)

KAUST Repository

Zhu, Jia; Jia, Nana; Yang, Lijun; Su, Dong; Park, Jinseong; Choi, YongMan; Gong, Kuanping

2014-01-01

A self-assembly approach to preparing iron phthalocyanine/single-walled carbon nanotube (FePc/SWNT) heterojunction nanowires as a new oxygen reduction reaction (ORR) electrocatalyst has been developed by virtue of water-adjusted dispersing in 1

Renal cortex copper concentration in acute copper poisoning in calves

Directory of Open Access Journals (Sweden)

Luis E. Fazzio

2012-01-01

Full Text Available The aim of this study was to estimate the diagnostic value of renal cortex copper (Cu concentration in clinical cases of acute copper poisoning (ACP. A total of 97 calves that died due to subcutaneous copper administration were compiled in eleven farms. At least, one necropsy was conducted on each farm and samples for complementary analysis were taken. The degree of autolysis in each necropsy was evaluated. The cases appeared on extensive grazing calf breeding and intensive feedlot farms, in calves of 60 to 200 kg body weight. Mortality varied from 0.86 to 6.96 %, on the farms studied. The first succumbed calf was found on the farms between 6 and 72 hours after the susbcutaneous Cu administration. As discrepancies regarding the reference value arose, the local value (19.9 parts per million was used, confirming the diagnosis of acute copper poisoning in 93% of the analyzed kidney samples. These results confirm the value of analysis of the cortical kidney Cu concentration for the diagnosis of acute copper poisoning.

Preparation of copper and silicon/copper powders by a gas ...

Indian Academy of Sciences (India)

Administrator

aCentre for Materials Research, Department of Imaging and Applied Physics, ... Copper powder; Si/Cu composite particle; gas evaporation–condensation method; characteriza- tion. .... from the liquid metal surface, the mixed vapour of copper.

Posttranslational regulation of copper transporters

NARCIS (Netherlands)

van den Berghe, P.V.E.

2009-01-01

The transition metal copper is an essential cofactor for many redox-active enzymes, but excessive copper can generate toxic reactive oxygen species. Copper homeostasis is maintained by highly conserved proteins, to balance copper uptake, distribution and export on the systemic and cellular level.

RECYCLING OF SCRAP AND WASTE OF COPPER AND COPPER ALLOYS IN BELARUS

Directory of Open Access Journals (Sweden)

S. L. Rovin

2017-01-01

Full Text Available The construction of a new casting and mechanical shop of unitary enterprise «Tsvetmet» in December 2015 has allowed to solve the complex problem of processing and utilization of scrap and wastes of copper and copper alloys in the Republic of Belarus. The technological processes of fire refinement of copper and manufacturing of copper rod from scrap and production of brass rod by hot pressing (extrusion of the continuously casted round billet have been mastered for the first time in the Republic of Belarus.

Phthalocyanine-conjugated upconversion NaYF4:Yb3+/Er3+@SiO2 nanospheres for NIR-triggered photodynamic therapy in a tumor mouse model

Czech Academy of Sciences Publication Activity Database

Kostiv, Uliana; Patsula, Vitalii; Noculak, A.; Podhorodecki, A.; Větvička, D.; Poučková, P.; Sedláková, Zdeňka; Horák, Daniel

2017-01-01

Roč. 12, Issue 24 (2017), s. 2066-2073 ISSN 1860-7179 R&D Projects: GA ČR(CZ) GA15-01897S Institutional support: RVO:61389013 Keywords : upconversion nanospheres * phthalocyanine * photodynamic therapy Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.225, year: 2016

Demystifying Controlling Copper Corrosion

Science.gov (United States)

The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

Copper Bioleaching in Chile

OpenAIRE

Juan Carlos Gentina; Fernando Acevedo

2016-01-01

Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first...