Demolition, Construction, Operation and Maintenance of New Boat Docks, Boat Ramp, and Support Facility at Cape Canaveral Air Force Station, Florida. Environmental Assessment. Version 1.3

DTIC Science & Technology

2006-08-16

invasive weeds present in lower densities. In addition, cogon grass , melaleuca, mistletoe (Phoradendron serotinum), and small populations of thistles...area. Adverse impacts to indigos are not expected since the area consists of mowed grass only. To ensure potential impacts are reduced, the 45 SW...inside the Trident Basin, is primarily grass with rock revetment. The security activities would require boat operations in other areas of the Port as

Implementation of STUD Pulses at the Trident Laser and Initial Results

NASA Astrophysics Data System (ADS)

Johnson, R. P.; Shimada, T.; Montgomery, D. S.; Afeyan, B.; Hüller, S.

2012-10-01

Controlling and mitigating laser-plasma instabilities such as stimulated Brillouin scattering, stimulated Raman scattering, and crossed-beam energy transfer is important to achieve high-gain inertial fusion using laser drivers. Recent theory and simulations show that these instabilities can be largely controlled using laser pulses consisting of spike trains of uneven duration and delay (STUD) by modulating the laser on a picosecond time scale [1,2]. We have designed and implemented a STUD pulse generator at the LANL Trident Laser Facility using Fourier synthesis to produce a 0.5-ns envelope of psec-duration STUD pulses using a spatial light modulator. Initial results from laser propagation tests and measurements as well as initial laser-plasma characterization experiments will be presented.[4pt] [1] B. Afeyan and S. H"uller, ``Optimal Control of Laser Plasma Instabilities using STUD pulses,'' IFSA 2011, P.Mo.1, to appear in Euro. Phys. J. Web of Conf. (2012).[2] S. H"uller and B. Afeyan, ``Simulations of drastically reduced SBS with STUD pulses,'' IFSA 2011, O.Tu8-1, to appear in Euro. Phys. J. Web of Conf. (2012).

A trident dithienylethene-perylenemonoimide dyad with super fluorescence switching speed and ratio

NASA Astrophysics Data System (ADS)

Li, Chong; Yan, Hui; Zhao, Ling-Xi; Zhang, Guo-Feng; Hu, Zhe; Huang, Zhen-Li; Zhu, Ming-Qiang

2014-12-01

Photoswitchable fluorescent diarylethenes are promising in molecular optical memory and photonic devices. However, the performance of current diarylethenes is far from satisfactory because of the scarcity of high-speed switching capability and large fluorescence on-off ratio. Here we report a trident perylenemonoimide dyad modified by triple dithienylethenes whose photochromic fluorescence quenching ratio at the photostationary state exceeds 10,000 and the fluorescence quenching efficiency is close to 100% within seconds of ultraviolet irradiation. The highly sensitive fluorescence on/off switching of the trident dyad enables recyclable fluorescence patterning and all-optical transistors. The prototype optical device based on the trident dyad enables the optical switching of incident light and conversion from incident light wavelength to transmitted light wavelength, which is all-optically controlled, reversible and wavelength-convertible. In addition, the trident dyad-staining block copolymer vesicles are observed via optical nanoimaging with a sub-100 nm resolution, portending a potential prospect of the dithienylethene dyad in super-resolution imaging.

A trident dithienylethene-perylenemonoimide dyad with super fluorescence switching speed and ratio.

PubMed

Li, Chong; Yan, Hui; Zhao, Ling-Xi; Zhang, Guo-Feng; Hu, Zhe; Huang, Zhen-Li; Zhu, Ming-Qiang

2014-12-12

Photoswitchable fluorescent diarylethenes are promising in molecular optical memory and photonic devices. However, the performance of current diarylethenes is far from satisfactory because of the scarcity of high-speed switching capability and large fluorescence on-off ratio. Here we report a trident perylenemonoimide dyad modified by triple dithienylethenes whose photochromic fluorescence quenching ratio at the photostationary state exceeds 10,000 and the fluorescence quenching efficiency is close to 100% within seconds of ultraviolet irradiation. The highly sensitive fluorescence on/off switching of the trident dyad enables recyclable fluorescence patterning and all-optical transistors. The prototype optical device based on the trident dyad enables the optical switching of incident light and conversion from incident light wavelength to transmitted light wavelength, which is all-optically controlled, reversible and wavelength-convertible. In addition, the trident dyad-staining block copolymer vesicles are observed via optical nanoimaging with a sub-100 nm resolution, portending a potential prospect of the dithienylethene dyad in super-resolution imaging.

Neutron imaging with the short-pulse laser driven neutron source at the TRIDENT Laser Facility

DOE PAGES

Guler, Nevzat; Volegov, Petr Lvovich; Favalli, Andrea; ...

2016-10-17

Emerging approaches to short-pulse laser-driven neutron production offer a possible gateway to compact, low cost, and intense broad spectrum sources for a wide variety of applications. They are based on energetic ions, driven by an intense short-pulse laser, interacting with a converter material to produce neutrons via breakup and nuclear reactions. Recent experiments performed with the high-contrast laser at the Trident laser facility of Los Alamos National Laboratory have demonstrated a laser-driven ion acceleration mechanism operating in the regime of relativistic transparency, featuring a volumetric laser-plasma interaction. This mechanism is distinct from previously studied ones that accelerate ions at themore » laser-target surface. The Trident experiments produced an intense beam of deuterons with an energy distribution extending above 100 MeV. This deuteron beam, when directed at a beryllium converter, produces a forward-directed neutron beam with ~5x10 9 n/sr, in a single laser shot, primarily due to deuteron breakup. The neutron beam has a pulse duration on the order of a few nanoseconds with an energy distribution extending from a few hundreds of keV to almost 80 MeV. For the experiments on neutron-source spot-size measurements, our gated neutron imager was setup to select neutrons in the energy range of 2.5 to 35 MeV. The spot size of neutron emission at the converter was measured by two different imaging techniques, using a knife-edge and a penumbral aperture, in two different experimental campaigns. The neutron-source spot size is measured ~1 mm for both experiments. The measurements and analysis reported here give a spatial characterization for this type of neutron source for the first time. In addition, the forward modeling performed provides an empirical estimate of the spatial characteristics of the deuteron ion-beam. Finally, these experimental observations, taken together, provide essential yet unique data to benchmark and verify theoretical work into the basic acceleration mechanism, which remains an ongoing challenge.« less

Neutron imaging with the short-pulse laser driven neutron source at the TRIDENT Laser Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guler, Nevzat; Volegov, Petr Lvovich; Favalli, Andrea

Emerging approaches to short-pulse laser-driven neutron production offer a possible gateway to compact, low cost, and intense broad spectrum sources for a wide variety of applications. They are based on energetic ions, driven by an intense short-pulse laser, interacting with a converter material to produce neutrons via breakup and nuclear reactions. Recent experiments performed with the high-contrast laser at the Trident laser facility of Los Alamos National Laboratory have demonstrated a laser-driven ion acceleration mechanism operating in the regime of relativistic transparency, featuring a volumetric laser-plasma interaction. This mechanism is distinct from previously studied ones that accelerate ions at themore » laser-target surface. The Trident experiments produced an intense beam of deuterons with an energy distribution extending above 100 MeV. This deuteron beam, when directed at a beryllium converter, produces a forward-directed neutron beam with ~5x10 9 n/sr, in a single laser shot, primarily due to deuteron breakup. The neutron beam has a pulse duration on the order of a few nanoseconds with an energy distribution extending from a few hundreds of keV to almost 80 MeV. For the experiments on neutron-source spot-size measurements, our gated neutron imager was setup to select neutrons in the energy range of 2.5 to 35 MeV. The spot size of neutron emission at the converter was measured by two different imaging techniques, using a knife-edge and a penumbral aperture, in two different experimental campaigns. The neutron-source spot size is measured ~1 mm for both experiments. The measurements and analysis reported here give a spatial characterization for this type of neutron source for the first time. In addition, the forward modeling performed provides an empirical estimate of the spatial characteristics of the deuteron ion-beam. Finally, these experimental observations, taken together, provide essential yet unique data to benchmark and verify theoretical work into the basic acceleration mechanism, which remains an ongoing challenge.« less

The Falcon and the Trident: Air Force-Navy Airpower Coordination and the New MRC Model

DTIC Science & Technology

1994-06-01

other ships from Australia and New Zealand , quickly placed themselves at NavFE’s disposal. At the same time, MacArthur received orders from the JCS...THE FALCON AND THE TRIDENT: AIR FORCE-NAVY AIRPOWER COORDINATION AND THE NEW MRC MODEL MARK S. HOFFMAN, MAJ, USAF...TITLE AND SUBTITLE The Falcon and The Trident: Air Force-Navy Airpower Coordination and The New MRC Model 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

Quantification of uncertainty in photon source spot size inference during laser-driven radiography experiments at TRIDENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tobias, Benjamin John; Palaniyappan, Sasikumar; Gautier, Donald Cort

Images of the R2DTO resolution target were obtained during laser-driven-radiography experiments performed at the TRIDENT laser facility, and analysis of these images using the Bayesian Inference Engine (BIE) determines a most probable full-width half maximum (FWHM) spot size of 78 μm. However, significant uncertainty prevails due to variation in the measured detector blur. Propagating this uncertainty in detector blur through the forward model results in an interval of probabilistic ambiguity spanning approximately 35-195 μm when the laser energy impinges on a thick (1 mm) tantalum target. In other phases of the experiment, laser energy is deposited on a thin (~100more » nm) aluminum target placed 250 μm ahead of the tantalum converter. When the energetic electron beam is generated in this manner, upstream from the bremsstrahlung converter, the inferred spot size shifts to a range of much larger values, approximately 270-600 μm FWHM. This report discusses methods applied to obtain these intervals as well as concepts necessary for interpreting the result within a context of probabilistic quantitative inference.« less

Geochemical constraints on volatile sources and subsurface conditions at Mount Martin, Mount Mageik, and Trident Volcanoes, Katmai Volcanic Cluster, Alaska

NASA Astrophysics Data System (ADS)

Lopez, T.; Tassi, F.; Aiuppa, A.; Galle, B.; Rizzo, A. L.; Fiebig, J.; Capecchiacci, F.; Giudice, G.; Caliro, S.; Tamburello, G.

2017-11-01

We use the chemical and isotopic composition of volcanic gases and steam condensate, in situ measurements of plume composition and remote measurements of SO2 flux to constrain volatile sources and characterize subvolcanic conditions at three persistently degassing and seismically active volcanoes within the Katmai Volcanic Cluster (KVC), Alaska: Mount Martin, Mount Mageik and Trident. In situ plume measurements of gas composition were collected at all three volcanoes using MultiGAS instruments to calculate gas ratios (e.g. CO2/H2S, SO2/H2S and H2O/H2S), and remote measurements of SO2 column density were collected from Mount Martin and Mount Mageik by ultraviolet spectrometer systems to calculate SO2 fluxes. Fumaroles were directly sampled for chemical and isotopic composition from Mount Mageik and Trident. Mid Ocean Ridge Basalt (MORB)-like 3He/4He ratios ( 7.2-7.6 Rc/RA) within Mount Mageik and Trident's fumarole emissions and a moderate SO2 flux ( 75 t/d) from Mount Martin, combined with gas compositions dominated by H2O, CO2 and H2S from all three volcanoes, indicate magma degassing and active hydrothermal systems in the subsurface of these volcanoes. Mount Martin's gas emissions have the lowest CO2/H2S ratio ( 2-4) and highest SO2 flux compared to the other KVC volcanoes, indicative of shallow magma degassing. Geothermometry techniques applied to Mount Mageik and Trident's fumarolic gas compositions suggest that their hydrothermal reservoirs are located at depths of 0.2 and 4 km below the surface, respectively. Observations of an unusually reducing gas composition at Trident and organic material in the near-surface soils suggest that thermal decomposition of sediments may be influencing gas composition. When the measured gas compositions from Mount Mageik and Trident are compared with previous samples collected in the late 1990's, relatively stable magmatic-hydrothermal conditions are inferred for Mount Mageik, while gradual degassing of residual magma and contamination by shallow crustal fluids is inferred for Trident. The isotopic composition of volcanic gases emitted from Mount Mageik and Trident reflect mixing of subducted slab, mantle and crustal volatile sources, with organic sediment and carbonate being the predominant sources. Considering the close proximity of the target volcanoes in comparison with the depth to the subducted slab we speculate that Aleutian Arc volatiles are fed by a relatively homogeneous subducted fluid and that much of the apparent variability in volatile provenance can be explained by shallow crustal volatile sources and/or processes.

Spatially resolved density and ionization measurements of shocked foams using x-ray fluorescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacDonald, M. J.; Keiter, P. A.; Montgomery, D. S.

2016-09-28

We present experiments at the Trident laser facility demonstrating the use of x-ray fluorescence (XRF) to simultaneously measure density, ionization state populations, and electron temperature in shocked foams. An imaging x-ray spectrometer obtained spatially resolved measurements of Ti K-α emission. Density profiles were measured from K-α intensity. Ti ionization state distributions and electron temperatures were inferred by fitting K-α spectra to spectra from CRETIN simulations. This work shows that XRF provides a powerful tool to complement other diagnostics to make equation of state measurements of shocked materials containing a suitable tracer element.

Los Alamos Using Neutrons to Stop Nuclear Smugglers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Favalli, Andrea; Swinhoe, Martyn; Roark, Kevin

Los Alamos National Laboratory researchers have successfully demonstrated for the first time that laser-generated neutrons can be enlisted as a useful tool in the War on Terror. The international research team used the short-pulse laser at Los Alamos's TRIDENT facility to generate a neutron beam with novel characteristics that interrogated a closed container to confirm the presence and quantity of nuclear material inside. The successful experiment paves the way for creation of a table-top-sized or truck-mounted neutron generator that could be installed at strategic locations worldwide to thwart smugglers trafficking in nuclear materials.

Los Alamos Using Neutrons to Stop Nuclear Smugglers

ScienceCinema

Favalli, Andrea; Swinhoe, Martyn; Roark, Kevin

2018-02-14

Los Alamos National Laboratory researchers have successfully demonstrated for the first time that laser-generated neutrons can be enlisted as a useful tool in the War on Terror. The international research team used the short-pulse laser at Los Alamos's TRIDENT facility to generate a neutron beam with novel characteristics that interrogated a closed container to confirm the presence and quantity of nuclear material inside. The successful experiment paves the way for creation of a table-top-sized or truck-mounted neutron generator that could be installed at strategic locations worldwide to thwart smugglers trafficking in nuclear materials.

Trident Technical College 1999 Fact Book.

ERIC Educational Resources Information Center

Trident Technical Coll., Charleston, SC.

Presents the 12th edition of the Trident Technical College (South Carolina) Fact Book, which offers relevant information on principal characteristics and strengths of the college. Includes the following chapters: (1) general information, such as vision and mission statements, institutional goals, history, and accreditation; (2) enrollment…

Trident Technical College 1999 Graduate Follow-Up Report.

ERIC Educational Resources Information Center

Trident Technical Coll., Charleston, SC.

Presents the results of South Carolina's Trident Technical College's (TTC's) 1999 graduate follow-up survey report. Graduates were surveyed and results were obtained for the following items: graduate goals, employment, placement rates, graduates in related fields, when job obtained, job finding methods, job locations, job satisfaction, job…

Synthesis, spectroscopic characterization, electrochemical behaviour, reactivity and antibacterial activity of some transition metal complexes with 2-(N-salicylideneamino)-3-carboxyethyl-4,5-dimethylthiophene.

PubMed

Daniel, Varughese P; Murukan, B; Kumari, B Sindhu; Mohanan, K

2008-07-01

Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes with a potentially tridentate Schiff base, formed by condensation of 2-amino-3-carboxyethyl-4,5-dimethylthiophene with salicylaldehyde were synthesized and characterized on the basis of elemental analyses, molar conductance values, magnetic susceptibility measurements, UV-vis, IR, EPR and NMR spectral data, wherever possible and applicable. Spectral studies reveal that the free ligand exists in a bifunctionally hydrogen bonded manner and coordinates to the metal ion in a tridentate fashion through the deprotonated phenolate oxygen, azomethine nitrogen and ester carbonyl group. On the basis of electronic spectral data and magnetic susceptibility measurements, suitable geometry has been proposed for each complex. The EPR spectral data of the Cu(II) complex showed that the metal-ligand bonds have considerable covalent character. The Ni(II) complex has undergone facile transesterification reaction when refluxed in methanol for a lengthy period. X-ray diffraction studies of Cu(II) complex showed that the complex has an orthorhombic crystal lattice. In view of the biological activity of thiophene derivatives, the ligand and the complexes were subjected to antibacterial screening. It has been observed that the antibacterial activity of the ligand increased on chelation with metal ion.

Trident Technical College 1998 Graduate Follow-Up.

ERIC Educational Resources Information Center

Trident Technical Coll., Charleston, SC.

Presents the results of South Carolina's Trident Technical College's (TTC's) 1998 graduate follow-up survey report of 915 TTC graduates. Graduates were surveyed and results were obtained for the following items: graduate goals, employment, placement rates, graduates in related fields, when job were obtained, job finding methods, job locations, job…

KSC-07pd0636

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- A flat bed truck hauls the container with the Experiment Logistics Module Pressurized Section inside away from the Trident wharf. The logistics module is part of the Japanese Experiment Module, known as Kibo. The logistics module is being transported to the Space Station Processing Facility at NASA's Kennedy Space Center. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

Trident sign trumps Aquaporin-4-IgG ELISA in diagnostic value in a case of longitudinally extensive transverse myelitis.

PubMed

Jolliffe, Evan A; Keegan, B Mark; Flanagan, Eoin P

2018-04-21

Longitudinally-extensive T2-hyperintense spinal cord lesions (≥3 vertebral segments) are associated with neuromyelitis optical spectrum disorder but occur with other disorders including spinal cord sarcoidosis. When linear dorsal subpial enhancement is accompanied by central cord/canal enhancement the axial post-gadolinium sequences may reveal a "trident" pattern that has previously been shown to be strongly suggestive of spinal cord sarcoidosis. We report a case in which the patient was initially diagnosed with neuromyelitis optical spectrum disorder, but where the "trident" sign ultimately led to the correct diagnosis of spinal cord sarcoidosis. Copyright © 2018. Published by Elsevier B.V.

Navy Trident Submarine Conversion (SSGN) Program: Background and Issues for Congress

DTIC Science & Technology

2008-05-22

the Kamehameha (SSBN-642) — two older-generation SSBNs that were converted into SSNs specifically for supporting larger numbers of SOF personnel. The...Polk was retired in 1999 at age 33; the Kamehameha was retired in 2002 at age 36. Trident SSGNs and Navy Transformation. The Bush Administration and

Navy Trident Submarine Conversion (SSGN) Program: Background and Issues for Congress

DTIC Science & Technology

2008-10-02

the Kamehameha (SSBN-642) — two older-generation SSBNs that were converted into SSNs specifically for supporting larger numbers of SOF personnel. The...Polk was retired in 1999 at age 33; the Kamehameha was retired in 2002 at age 36. Trident SSGNs and Navy Transformation. The Bush Administration and

Trident: A Universal Tool for Generating Synthetic Absorption Spectra from Astrophysical Simulations

NASA Astrophysics Data System (ADS)

Hummels, Cameron B.; Smith, Britton D.; Silvia, Devin W.

2017-09-01

Hydrodynamical simulations are increasingly able to accurately model physical systems on stellar, galactic, and cosmological scales; however, the utility of these simulations is often limited by our ability to directly compare them with the data sets produced by observers: spectra, photometry, etc. To address this problem, we have created trident, a Python-based open-source tool for post-processing hydrodynamical simulations to produce synthetic absorption spectra and related data. trident can (I) create absorption-line spectra for any trajectory through a simulated data set mimicking both background quasar and down-the-barrel configurations; (II) reproduce the spectral characteristics of common instruments like the Cosmic Origins Spectrograph; (III) operate across the ultraviolet, optical, and infrared using customizable absorption-line lists; (IV) trace simulated physical structures directly to spectral features; (v) approximate the presence of ion species absent from the simulation outputs; (VI) generate column density maps for any ion; and (vii) provide support for all major astrophysical hydrodynamical codes. trident was originally developed to aid in the interpretation of observations of the circumgalactic medium and intergalactic medium, but it remains a general tool applicable in other contexts.

Spatially resolved density and ionization measurements of shocked foams using x-ray fluorescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacDonald, M. J.; Keiter, P. A.; Montgomery, D. S.

2016-09-22

We present experiments at the Trident laser facility demonstrating the use of x-ray fluorescence (XRF) to simultaneously measure density, ionization state populations, and electron temperature in shocked foams. An imaging x-ray spectrometer was used to obtain spatially-resolved measurements of Ti K-more » $$\\alpha$$ emission. Density profiles were measured from K-$$\\alpha$$ intensity. Ti ionization state distributions and electron temperatures were inferred by fitting K-$$\\alpha$$ spectra to spectra from CRETIN simulations. This study shows that XRF provides a powerful tool to complement other diagnostics to make equation of state measurements of shocked materials containing a suitable tracer element.« less

Trident: A Universal Tool for Generating Synthetic Absorption Spectra from Astrophysical Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hummels, Cameron B.; Smith, Britton D.; Silvia, Devin W.

Hydrodynamical simulations are increasingly able to accurately model physical systems on stellar, galactic, and cosmological scales; however, the utility of these simulations is often limited by our ability to directly compare them with the data sets produced by observers: spectra, photometry, etc. To address this problem, we have created trident, a Python-based open-source tool for post-processing hydrodynamical simulations to produce synthetic absorption spectra and related data. trident can (i) create absorption-line spectra for any trajectory through a simulated data set mimicking both background quasar and down-the-barrel configurations; (ii) reproduce the spectral characteristics of common instruments like the Cosmic Origins Spectrograph;more » (iii) operate across the ultraviolet, optical, and infrared using customizable absorption-line lists; (iv) trace simulated physical structures directly to spectral features; (v) approximate the presence of ion species absent from the simulation outputs; (vi) generate column density maps for any ion; and (vii) provide support for all major astrophysical hydrodynamical codes. trident was originally developed to aid in the interpretation of observations of the circumgalactic medium and intergalactic medium, but it remains a general tool applicable in other contexts.« less

Trident and MISTY: a universal pipeline for generating and sharing synthetic spectra

NASA Astrophysics Data System (ADS)

Hummels, Cameron; Smith, Britton; Silvia, Devin; Peeples, Molly; Prochaska, X.; Tejos, Nicolas

2016-03-01

Astrophysical simulations are useful insofar as they aid in the interpretation of telescopic observations. Thus, a primary task in simulation analysis is in producing synthetic observations for direct comparison against observational data. Furthermore, we as a field need an effective means for storing these synthetic observable data products, such that they are accessible and searchable by the entire population of researchers. In this talk, we present Trident, a universal pipeline for producing synthetic spectra from any of the major hydrodynamics codes, and MISTY, a means of storing these spectra on the HST MAST data archive. Trident and MISTY are our attempts to solve the difficult problems of synthetic data production and publicly-accessible storage for the scientific communities studying the intergalactic medium and circumgalactic medium.

KSC-07pd0635

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- A flat bed truck hauls the container with the Experiment Logistics Module Pressurized Section inside away from the Trident wharf. The logistics module is part of the Japanese Experiment Module. The logistics module is being transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0632

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, workers help guide the container with the Experiment Logistics Module Pressurized Section inside toward the dock. The logistics module is part of the Japanese Experiment Module. The logistics module will be transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0626

NASA Image and Video Library

2007-03-12

KENNEDY SPACE CENTER, FLA. -- The ship carrying the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module arrives at the Trident wharf after departing from Yokohama, Japan, Feb. 7. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0628

NASA Image and Video Library

2007-03-12

KENNEDY SPACE CENTER, FLA. -- The ship carrying the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module arrives at the Trident wharf after departing from Yokohama, Japan, Feb. 7. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0627

NASA Image and Video Library

2007-03-12

KENNEDY SPACE CENTER, FLA. -- The ship carrying the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module arrives at the Trident wharf after departing from Yokohama, Japan, Feb. 7. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0629

NASA Image and Video Library

2007-03-12

KENNEDY SPACE CENTER, FLA. -- The ship carrying the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module is tied up at the Trident wharf after departing from Yokohama, Japan, Feb. 7. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

Demonstration of x-ray fluorescence imaging of a high-energy-density plasma.

PubMed

MacDonald, M J; Keiter, P A; Montgomery, D S; Biener, M M; Fein, J R; Fournier, K B; Gamboa, E J; Klein, S R; Kuranz, C C; LeFevre, H J; Manuel, M J-E; Streit, J; Wan, W C; Drake, R P

2014-11-01

Experiments at the Trident Laser Facility have successfully demonstrated the use of x-ray fluorescence imaging (XRFI) to diagnose shocked carbonized resorcinol formaldehyde (CRF) foams doped with Ti. One laser beam created a shock wave in the doped foam. A second laser beam produced a flux of vanadium He-α x-rays, which in turn induced Ti K-shell fluorescence within the foam. Spectrally resolved 1D imaging of the x-ray fluorescence provided shock location and compression measurements. Additionally, experiments using a collimator demonstrated that one can probe specific regions within a target. These results show that XRFI is a capable alternative to path-integrated measurements for diagnosing hydrodynamic experiments at high energy density.

Nanoscale control of competing interactions and geometrical frustration in a dipolar trident lattice

DOE PAGES

Farhan, Alan; Petersen, Charlotte F.; Dhuey, Scott; ...

2017-10-17

Geometrical frustration occurs when entities in a system, subject to given lattice constraints, are hindered to simultaneously minimize their local interactions. In magnetism, systems incorporating geometrical frustration are fascinating, as their behavior is not only hard to predict, but also leads to the emergence of exotic states of matter. Here, we provide a first look into an artificial frustrated system, the dipolar trident lattice, where the balance of competing interactions between nearest-neighbor magnetic moments can be directly controlled, thus allowing versatile tuning of geometrical frustration and manipulation of ground state configurations. Our findings not only provide the basis for futuremore » studies on the low-temperature physics of the dipolar trident lattice, but also demonstrate how this frustration-by-design concept can deliver magnetically frustrated metamaterials.« less

On track for success: an innovative behavioral science curriculum model.

PubMed

Freedy, John R; Carek, Peter J; Dickerson, Lori M; Mallin, Robert M

2013-01-01

This article describes the behavioral science curriculum currently in place at the Trident/MUSC Family Medicine Residency Program. The Trident/MUSC Program is a 10-10-10 community-based, university-affiliated program in Charleston, South Carolina. Over the years, the Trident/MUSC residency program has graduated over 400 Family Medicine physicians. The current behavioral science curriculum consists of both required core elements (didactic lectures, clinical observation, Balint groups, and Resident Grand Rounds) as well as optional elements (longitudinal patient care experiences, elective rotations, behavioral science editorial experience, and scholars project with a behavioral science focus). All Trident/MUSC residents complete core behavioral science curriculum elements and are free to participate in none, some, or all of the optional behavioral science curriculum elements. This flexibility allows resident physicians to tailor the educational program in a manner to meet individual educational needs. The behavioral science curriculum is based upon faculty interpretation of existing "best practice" guidelines (Residency Review Committee-Family Medicine and AAFP). This article provides sufficient curriculum detail to allow the interested reader the opportunity to adapt elements of the behavioral science curriculum to other residency training programs. While this behavioral science track system is currently in an early stage of implementation, the article discusses track advantages as well as future plans to evaluate various aspects of this innovative educational approach.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chevallier, J.; Turner, L.

This article describes the design and operation of Trident IX a successfully applied jack up system. A summary of Trident IX's two years of operation in the Arabian Gulf and offshore West Africa is presented. The system is compared to conventional jacking systems in terms of design, operation, costs and safety. Dynamic forces at 400 ft. water depths are summarized, and design of the legs to withstand these dynamic forces and accomodate the new system are explained. Features are listed.

Defects in Calcite.

DTIC Science & Technology

1991-05-13

AD-A245 645 A TRIDENT SCHOLAR PROJECT REPORT NO. 181 "DEFECTS IN CALCITE " DTTC %N FEB 5-1912 UNITED STATES NAVAL ACADEMY ANNAPOLIS, MARYLAND 92-02841...report; no. 181 (1991) "DEFECTS IN CALCITE " A Trident Scholar Project Report by Midshipman Anthony J. Kotarski, Class of 1991 U. S. Naval Academy Annapolis...REPORT TYPE AND DATES COVERED 13 May 1991 Final 1990/91 . TITLE AND SUBTITLE s. FUNDING NUMBERS DEFECTS IN CALCITE 6. AUTHOR(S) Anthony J. Kotarski 7

From the Stream to the Shore: Forecasting Complex Ocean Environments in Trident Warrior 13

DTIC Science & Technology

2016-09-15

computing, and modeling | 2014 NRL REVIEW Acknowledgments: Our work in Trident Warrior 2013 was made possible through the support of the Of- fice...Standard Form 298 (Rev. 8/98) REPORT DOCUMENTATION PAGE Prescribed by ANSI Std. Z39.18 Form Approved OMB No. 0704-0188 The public reporting...burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing

Synthesis, spectral and magnetic studies of mono- and bi-nuclear metal complexes of a new bis(tridentate NO2) Schiff base ligand derived from 4,6-diacetylresorcinol and ethanolamine.

PubMed

Shebl, Magdy

2009-07-15

A new bis(tridentate NO2) Schiff base ligand, H(4)L, was prepared by the reaction of the bifunctional carbonyl compound; 4,6-diacetylresorcinol (DAR) with ethanolamine. The ligand reacted with iron(III), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), cerium(III) and uranyl(VI) ions, in absence and in presence of LiOH, to yield mono- and bi-nuclear complexes with different coordinating sites. The ligand and its metal complexes were characterized by elemental analyses, IR, (1)H NMR, electronic, ESR and mass spectra, conductivity and magnetic susceptibility measurements as well as thermal analyses. In absence of LiOH, mononuclear complexes (2, 3 and 5-9) as well as binuclear complexes (1 and 4) were obtained. In mononuclear complexes, the ligand acted as a neutral, mono- and di-basic/bi- and tetra-dentate ligand while in binuclear complexes (1 and 4), the ligand acted as a bis(mono- or di-basic/tridentate) ligand. On the other hand, in presence of LiOH, only binuclear complexes (10-15) were obtained in which the ligand acted as a bis(dibasic tridentate) ligand. The metal complexes exhibited different geometrical arrangements such as octahedral, tetrahedral, square planar, square pyramidal and pentagonal bipyramidal arrangements.

KSC-07pd0633

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, workers help guide the container with the Experiment Logistics Module Pressurized Section inside toward a flat bed on the dock. The logistics module is part of the Japanese Experiment Module. The logistics module will be transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0634

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, workers help guide the container with the Experiment Logistics Module Pressurized Section inside onto a flat bed on the dock. The logistics module is part of the Japanese Experiment Module. The logistics module will be transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0631

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, workers in the hold of a ship attach a crane to the shipping container with the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module. The ship brought the module from Yokohama, Japan. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0630

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, the shipping container with the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module is ready for lifting out of the hold of the ship that brought it from Yokohama, Japan. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

XAFS Study of the Ferro- and Antiferromagnetic Binuclear Copper(II) Complexes of Azomethine Based Tridentate Ligands

NASA Astrophysics Data System (ADS)

Vlasenko, Valery G.; Vasilchenko, Igor S.; Pirog, Irina V.; Shestakova, Tatiana E.; Uraev, Ali I.; Burlov, Anatolii S.; Garnovskii, Alexander D.

2007-02-01

Binuclear copper complexes are known to be models for metalloenzymes containing copper active sites, and some of them are of considerable interest due to their magnetic and charge transfer properties. The reactions of the complex formation of bibasic tridentate heterocyclic imines with copper acetate leads to two types of chelates with mono deprotonated ligands and with totally deprotonated ligands. Cu K-edge EXAFS has been applied to determine the local structure around the metal center in copper(II) azomethine complexes with five tridentate ligands: 1-(salycilideneimino)- or 1-(2-tosylaminobenzilideneimino)-2-amino(oxo, thio)benzimidazoles. It has been found that some of the chelates studied are bridged binuclear copper complexes, and others are mononuclear complexes. The copper-copper interatomic distances in the bridged binuclear copper complexes were found to be 2.85-3.01 Å. Variable temperature magnetic susceptibility data indicate the presence of both ferromagnetic and antiferromagnetic interactions within the dimer, the former is dominating at low temperatures and the latter at high temperatures.

Nanoscale control of competing interactions and geometrical frustration in a dipolar trident lattice.

PubMed

Farhan, Alan; Petersen, Charlotte F; Dhuey, Scott; Anghinolfi, Luca; Qin, Qi Hang; Saccone, Michael; Velten, Sven; Wuth, Clemens; Gliga, Sebastian; Mellado, Paula; Alava, Mikko J; Scholl, Andreas; van Dijken, Sebastiaan

2017-10-17

Geometrical frustration occurs when entities in a system, subject to given lattice constraints, are hindered to simultaneously minimize their local interactions. In magnetism, systems incorporating geometrical frustration are fascinating, as their behavior is not only hard to predict, but also leads to the emergence of exotic states of matter. Here, we provide a first look into an artificial frustrated system, the dipolar trident lattice, where the balance of competing interactions between nearest-neighbor magnetic moments can be directly controlled, thus allowing versatile tuning of geometrical frustration and manipulation of ground state configurations. Our findings not only provide the basis for future studies on the low-temperature physics of the dipolar trident lattice, but also demonstrate how this frustration-by-design concept can deliver magnetically frustrated metamaterials.Artificial magnetic nanostructures enable the study of competing frustrated interactions with more control over the system parameters than is possible in magnetic materials. Farhan et al. present a two-dimensional lattice geometry where the frustration can be controlled by tuning the unit cell parameters.

Derivatization of bichromic cyclometalated Ru(II) complexes with hydrophobic substituents.

PubMed

Robson, Kiyoshi C D; Koivisto, Bryan D; Berlinguette, Curtis P

2012-02-06

The syntheses and physical properties of cyclometalated Ru(II) complexes containing a triphenylamine (TPA) unit bearing aliphatic groups are reported. Each member of the series consists of an octahedral Ru(II) center coordinated by a tridentate polypyridyl ligand and a tridentate cyclometalating ligand. One of the chelating ligands contains electron-deficient methyl ester groups, while a TPA unit is attached to the central ring of the adjacent chelating ligand through a thiophene bridge. This study builds on our previous work (Inorg. Chem. 2011, 50, 6019-6028; Inorg. Chem. 2011, 50, 5494-5508) by (i) outlining a synthetic protocol for installing aliphatic groups on the TPA substituents, (ii) examining the role that terminal -O-hexyl and -S-hexyl groups situated on the TPA have on the electrochemical properties, and (iii) demonstrating the potential benefit of installing the TPA on the neutral chelating ligand rather than the anionic chelating ligand. The results reported herein provide important synthetic advances for our broader goal of developing bis-tridentate cyclometalated Ru(II) complexes for light-harvesting applications.

First light with Trident: multi-platform synthetic quasar spectra

NASA Astrophysics Data System (ADS)

Silvia, Devin W.; Hummels, Cameron B.; Smith, Britton

2017-01-01

Observational efforts to better understand the nature of the intergalactic and circumgalactic media have relied heavily on the information encoded in the absorption line systems of quasar spectra. Numerical simulations of large-scale structure and galaxy evolution are well-suited to explore the properties of those same media owing to the relative ease with which one can access physical quantities from complex, three-dimensional data. However, a difficulty arises when one tries to make direct “apple-to-apples” comparisons between observed spectra and simulated data. In an effort to provide a common language capable of linking theory and observation, we announce the release of Trident. Trident is a publicly available software tool that enables the creation of realistic synthetic absorption spectra from virtually all widely-used hydrodynamics simulation codes. Through user-controlled levels of spectral realism, direct comparisons between simulated and observed data become not only possible, but greatly simplified. We present the methods for extracting artificial quasar sightlines and generating spectra as well as early-stage applications of those spectra to intergalactic and circumgalactic absorption line studies.

A new species of Eunice (Polychaeta: Eunicidae) from Hainan Island, South China Sea

NASA Astrophysics Data System (ADS)

Wu, Xuwen; Sun, Ruiping; Liu, Ruiyu

2013-01-01

A taxonomic survey of benthic marine animals from coastal regions of Hainan Island, South China Sea, revealed specimens of a new species of Eunice (Polychaeta: Eunicida: Eunicidae), Eunice uschakovi n. sp., collected from the intertidal zone. The species belongs to the group of Eunice that has yellow tridentate subacicular hooks and branchiae scattered over an extensive region of the body. It resembles E. miurai and E. havaica in having both bidentate and tridentate falcigers, but can be readily distinguished by branchial features. Comparisons between E. uschakovi and the two related species are presented.

Calibrating the coordination chemistry tool chest: metrics of bi- and tridentate ligands.

PubMed

Aguilà, David; Escribano, Esther; Speed, Saskia; Talancón, Daniel; Yermán, Luis; Alvarez, Santiago

2009-09-07

Bi- and multidentate ligands form part of the tools commonly used for designing coordination and supramolecular complexes with desired stereochemistries. Parameters and concepts usually employed include the normalized bite of bidentate ligands, their cis- or trans-coordinating ability, their rigidity or flexibility, or the duality of some ligands that can act in chelating or dinucleating modes. In this contribution we present a structural database study of over one hundred bi- and tridentate ligands that allows us to parametrize their coordinating properties and discuss the relevance of such parameters for the choice of coordination polyhedron or coordination sites.

Experimental study of an isochorically heated heterogeneous interface. A progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez, Juan Carlos

2015-08-20

Outline of the presentation: Studying possible mix / interface motion between heterogeneous low/high Z interfaces driven by 2-fluid or kinetic plasma effects (Heated to few eV, Sharp (sub µm) interface); Isochoric heating to initialize interface done with Al quasimonoenergetic ion beams on Trident; Have measured isochoric heating in individual materials intended for compound targets; Fielded experiments on Trident to measure interface motion (Gold-diamond, tin-aluminium); Measured heated-sample temperature with streaked optical pyrometry (SOP) (UT Austin led (research contract), SOP tests → heating uniformity Vs thickness on Al foils. Results are being analyzed.

Eruption of Trident Volcano, Katmai National Monument, Alaska, February-June 1953

USGS Publications Warehouse

Snyder, George L.

1954-01-01

Trident Volcano, one of several 'extinct' volcanoes in Katmai National Monument, erupted on February 15, 1953. Observers in a U. S. Navy plane, 50 miles away, and in King Salmon, 75 miles away, reported an initial column of smoke that rose to an estimated 30, 000 feet. Thick smoke and fog on the succeeding 2 days prevented observers from identifying the erupting volcano or assessing the severity of the eruption. It is almost certain, however, that during the latter part of this foggy period, either Mount Martin or Mount Mageik, or both, were also erupting sizable ash clouds nearby. The first close aerial observations were made in clear weather on February 18. At this time a thick, blocky lava flow was seen issuing slowly from a new vent at an altitude of 3,600 feet on the southwest flank of Trident Volcano. Other volcanic orifices in the area were only steaming mildly on this and succeeding days. Observations made in the following weeks from Naval aircraft patrolling the area indicated that both gas and ash evolution and lava extrusion from the Trident vent were continuing without major interruption. By March 11 an estimated 80-160 million cubic yards of rock material had been extruded. Air photographs taken in April and June show that the extrusion of lava had continued intermittently and, by June 17, the volume of the pile was perhaps 300-400 million cubic yards of rock material. Ash eruptions also apparently occurred sporadically during this period, the last significant surge taking place June 30. No civilian or military installations have been endangered by this eruption at the date of writing.

Influence of the chelator structures on the stability of Re and Tc tricarbonyl complexes with iminodiacetic acid tridentate ligands: a computational study.

PubMed

Hernández-Valdés, Daniel; Rodríguez-Riera, Zalua; Díaz-García, Alicia; Benoist, Eric; Jáuregui-Haza, Ulises

2016-08-01

The development of novel radiopharmaceuticals for nuclear medicine based on M(CO)3 (M = Tc, Re) complexes has attracted great attention. The versatility of this core and the easy production of the fac-[M(CO)3(H2O)3](+) precursor could explain this interest. The main characteristics of these tricarbonyl complexes are the high substitution stability of the three CO ligands and the corresponding lability of the coordinated water molecules, yielding, via easy exchange of a variety of bi- and tridentate ligands, complexes xof very high kinetic stability. Here, a computational study of different tricarbonyl complexes of Re(I) and Tc(I) was performed using density functional theory. The solvent effect was simulated using the polarizable continuum model. These structures were used as a starting point to investigate the relative stabilities of tricarbonyl complexes with various tridentate ligands. These complexes included an iminodiacetic acid unit for tridentate coordination to the fac-[M(CO)3](+) moiety (M = Re, Tc), an aromatic ring system bearing a functional group (-NO2, -NH2, and -Cl) as a linking site model, and a tethering moiety (a methylene, ethylene, propylene butylene, or pentylene bridge) between the linking and coordinating sites. The optimized complexes showed geometries comparable to those inferred from X-ray data. In general, the Re complexes were more stable than the corresponding Tc complexes. Furthermore, using NH2 as the functional group, a medium length carbon chain, and ortho substitution increased complex stability. All of the bonds involving the metal center presented a closed shell interaction with dative or covalent character, and the strength of these bonds decreased in the sequence Tc-CO > Tc-O > Tc-N.

The Heavy Photon Search test detector

DOE PAGES

Battaglieri, M.; Boyarinov, S.; Bueltmann, S.; ...

2014-12-17

The Heavy Photon Search (HPS), an experiment to search for a hidden sector photon in fixed target electroproduction, is preparing for installation at the Thomas Jefferson National Accelerator Facility (JLab) in the Fall of 2014. As the first stage of this project, the HPS Test Run apparatus was constructed and operated in 2012 to demonstrate the experiment's technical feasibility and to confirm that the trigger rates and occupancies are as expected. This paper describes the HPS Test Run apparatus and readout electronics and its performance. In this setting, a heavy photon can be identified as a narrow peak in themore » e⁺e⁻invariant mass spectrum above the trident background or as a narrow invariant mass peak with a decay vertex displaced from the production target, so charged particle tracking and vertexing are needed for its detection. In the HPS Test Run, charged particles are measured with a compact forward silicon microstrip tracker inside a dipole magnet. Electromagnetic showers are detected in a PbW0 4 crystal calorimeter situated behind the magnet, and are used to trigger the experiment and identify electrons and positrons. Both detectors are placed close to the beam line and split top-bottom. This arrangement provides sensitivity to low-mass heavy photons, allows clear passage of the unscattered beam, and avoids the spray of degraded electrons coming from the target. The discrimination between prompt and displaced e⁺e⁻ pairs requires the first layer of silicon sensors be placed only 10 cm downstream of the target. The expected signal is small, and the trident background huge, so the experiment requires very large statistics. In addition, the HPS Test Run utilizes high-rate readout and data acquisition electronics and a fast trigger to exploit the essentially 100% duty cycle of the CEBAF accelerator at JLab.« less

Environmental health monograph

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1974-05-01

Current environmental programs intended to reduce or mediate environmental health hazards in Berkeley, Charleston, and Dorchester Counties, South Carolina, are described. The following areas are considered: air pollution, noise abatement, pesticide control, accident prevention, food and milk sanitation, occupational health housing, water supply, sewerage, industrial waste, solid waste disposal, and vector control. The lack of adequate technically trained manpower or funds to implement minimum codes currently in force in the Trident Region is noted. The wide range of public and private agencies concerned with environmental health issues creates complexities in dealing with these issues. Conflicting codes and standards exist atmore » various government levels. The Trident Health District Office Air Pollution Control Program provides the following: ambient air quality surveillance; review of plans and specifications for proposed air pollution control facilities and equipment; and air monitoring. A list of safety - related courses offered by the Greater Charleston Safety Council is provided. A lack of readily available statistics concerning the various kinds of accidents and the frequency of their occurrence is noted. Concern is also expressed over the lack of personnel to inspect the growing food service industry. Local activities in the area of occupational health are reported to be less than minimal. The Charleston County Health Department has recently introduced a rural sanitation program. The county also issues permits for septic tank installation. The Regional Planning Council for the area aids municipalities and counties in planning for and implementing supply control and solid waste management in compliance with Federal and State laws. Mosquito abatement, rabies control, and rodent control activities in the area are described. Portions of this document are not fully legible. (GRA)« less

The Synthesis and X-ray Structural Characterization of mer and fac isomers of the Technetium(I) Nitrosyl Complex [TcCl(2)(NO)(PNPpr)].

PubMed

Nicholson, T L; Mahmood, A; Refosco, F; Tisato, F; Müller, P; Jones, A G

2009-08-01

The nitrosyl complex H[TcNOCl(4)] reacts with the tridentate ligand bis[(2-diphenylphosphino)propyl]amine (PNPpr) to yield a mixture of the mer or fac isomers of [TcCl(2)(NO)(PNPpr)]. In acetonitrile, where the ligand is freely soluble, reaction occurs at room temperature to yield mostly the mer isomer with the linear nitrosyl ligand cis to the amine ligand; and the phosphine ligands arranged in a mutually trans orientation. The reaction in methanol requires reflux to dissolve the lipophilic ligand and generates the fac isomer of [TcCl2(NO)(PNPpr)] as the major product, with the tridentate ligand in a facial arrangement, leaving the chlorides and nitrosyl ligand in the remaining facial sites. The steric bulk of the tridentate ligand's diphenylphophino- moieties results in a significant distortion from octahedral geometry, with the P-Tc-P bond angle expanded to 99.48(4)°. The infrared spectra display absorptions from these nitrosyl ligands in the 1700 and 1800 cm(-1) regions for the fac and mer isomers respectively. The ESI(+) mass spectra each display the parent ion at 647 m/z.

Metal-assisted in situ formation of a tridentate acetylacetone ligand for complexation of fac-Re(CO)3+ for radiopharmaceutical applications.

PubMed

Benny, Paul D; Fugate, Glenn A; Barden, Adam O; Morley, Jennifer E; Silva-Lopez, Elsa; Twamley, Brendan

2008-04-07

Reaction of [NEt4]2[ReBr3(CO)3] with 2,4-pentanedione (acac) yields a complex of the type fac-Re(acac)(OH2)(CO)3 (1) under aqueous conditions. 1 was further reacted with a monodentate ligand (pyridine) to yield a fac-Re(acac)(pyridine)(CO)3 complex (2). Complex 1 was found to react with primary amines to generate a Schiff base (imine) in aqueous solutions. When a mixed-nitrogen donor bidentate ligand, 2-(2-aminoethyl)pyridine, that has different coordination affinities for fac-Re(acac)(OH2)(CO)3 was utilized, a unique tridentate ligand was formed in situ utilizing a metal-assisted Schiff base formation to yield a complex fac-Re(CO)3(3[(2-phenylethyl)imino]-2-pentanone) (3). Tridentate ligand formation was found to occur only with the Re-coordinated acac ligand. Reactions of acac with fac-Re(CO)3Br(2-(2-aminoethyl)pyridine) (4) or a mixture of [NEt4]2[ReBr3(CO)3], acac, and 2-(2-aminoethyl)pyridine did not yield the formation of complex 3 in water.

Proton deflectometry of laser-driven relativistic electron jet from thin foil target

NASA Astrophysics Data System (ADS)

Huang, Chengkun; Palaniyappan, S.; Gautier, D. C.; Johnson, R. P.; Shimada, T.; Fernandez, J. C.; Tsung, F. S.; Mori, W. B.

2017-10-01

Near critical density relativistic electron jets from laser solid interaction carry currents approaching the Alfvén-limit and tens of kilo-Tesla magnetic fields. Such jets are often found in kinetic simulations with low areal density targets, but have not been confirmed experimentally. They may be used for X/gamma-ray generation and is also important for the understanding of post-transparency plasma dynamics. With a short-pulse probe beam at the Trident laser facility, we employed proton deflectometry to infer the jet's properties, structure and the long-time dynamics. We develop corresponding GEANT4 simulation model of the proton deflectometry, with input from the kinetic PIC simulations in 2D and quasi-3D geometry, to compare with the experimental radiography images. Detail comparison of the experimental and simulation features in the deflectometry will be discussed. Work supported by the LDRD program at LANL.

Synthesis, crystal structure, fluorescence and electrochemical studies of a new tridentate Schiff base ligand and its nickel(II) and palladium(II) complexes

NASA Astrophysics Data System (ADS)

Shafaatian, Bita; Soleymanpour, Ahmad; Kholghi Oskouei, Nasim; Notash, Behrouz; Rezvani, Seyyed Ahmad

2014-07-01

A new unsymmetrical tridentate Schiff base ligand was derived from the 1:1 M condensation of ortho-vanillin with 2-mercaptoethylamine. Nickel and palladium complexes were obtained by the reaction of the tridentate Schiff base ligand with nickel(II) acetate tetrahydrate and palladium(II) acetate in 2:1 M ratio. In nickel and palladium complexes the ligand was coordinated to metals via the imine N and enolic O atoms. The S groups of Schiff bases were not coordinated to the metals and S-S coupling was occured. The complexes have been found to possess 1:2 Metal:Ligand stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The complexes exhibited octahedral coordination geometry. The emission spectra of the ligand and its complexes were studied in methanol. Electrochemical properties of the ligand and its metal complexes were investigated in the CH3CN solvent at the 100 mV s-1 scan rate. The ligand and metal complexes showed both reversible and quasi-reversible processes at this scan rate. The Schiff base and its complexes have been characterized by IR, 1H NMR, UV/Vis, elemental analyses and conductometry. The crystal structure of nickel complex has been determined by single crystal X-ray diffraction.

fac-Re(CO)3L complexes containing tridentate monoanionic ligands (L-) with a seldom-studied sulfonamido group as one terminal ligating group.

PubMed

Christoforou, Anna Maria; Fronczek, Frank R; Marzilli, Patricia A; Marzilli, Luigi G

2007-08-20

To achieve a net-neutral coordination unit in radiopharmaceuticals with a fac-M(CO)3+ core (M = Tc, Re), facially coordinated monoanionic tridentate ligands are needed. New neutral fac-Re(CO)3L complexes were obtained by treating fac-[Re(CO)3(H2O)3]+ with unsymmetrical tridentate NNN donor ligands (LH) based primarily on a diethylenetriamine (dien) moiety with an aromatic group linked to a terminal nitrogen through a sulfonamide. LHs contain 2,4,6-trimethylbenzenesulfonyl (tmbSO2) and 5-(dimethylamino)naphthalene-1-sulfonyl (DNS) groups. X-ray crystallographic and NMR analyses confirm that in both the solid and the solution states all L- in fac-Re(CO)3L complexes are bound in a tridentate fashion with one donor being nitrogen from a deprotonated sulfonamido group. Another fundamental property that is important in radiopharmaceuticals is shape, which in turn depends on ring pucker. For L- = tmbSO2-dien-, tmbSO2-N'-Medien-, and tmbSO2-N,N-Me2dien-, the two chelate rings have a different pucker chirality, as is commonly found for a broad range of metal complexes. However, for fac-Re(CO)3(DNS-dien), both chelate rings have the same pucker chirality because the sulfonamido ring has an unusual pucker for the absolute configuration at Re; a finding that is attributable to intramolecular and intermolecular hydrogen bonds from the sulfonamido oxygens to the NH2 groups. Averaging of tmb NMR signals, even at -90 degrees C for Re(CO)3(tmbSO2-N,N-Me2dien), indicates rapid dynamic motion in the complexes with this group. However, examination of the structures suggests that free rotation about the S-C(tmb) bond is not possible but that concerted coupled rotations about the N-S and the S-C bonds can explain the NMR data.

Catalytic hydrogenation using complexes of base metals with tridentate ligands

DOEpatents

Hanson, Susan K.; Zhang, Guoqi; Vasudevan, Kalyan V.

2017-02-14

Complexes of cobalt and nickel with tridentate ligand PNHP.sup.R are effective for hydrogenation of unsaturated compounds. Cobalt complex [(PNHP.sup.Cy)Co(CH.sub.2SiMe.sub.3)]BAr.sup.F.sub.4 (PNHP.sup.Cy=bis[2-(dicyclohexylphosphino)ethyl]amine, BAr.sup.F.sub.4=B(3,5-(CF.sub.3).sub.2C.sub.6H.sub.3).sub.4)) was prepared and used with hydrogen for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (25-60.degree. C., 1-4 atm H.sub.2). Nickel complex [(PNHP.sup.Cy)Ni(H)]BPh.sub.4 was used for hydrogenation of styrene and 1-octene under mild conditions. (PNP.sup.Cy)Ni(H) was used for hydrogenating alkenes.

Catalytic hydrogenation using complexes of base metals with tridentate ligands

DOEpatents

Vasudevan, Kalyan V.; Zhang, Guoqi; Hanson, Susan K.

2016-09-06

Complexes of cobalt and nickel with tridentate ligand PNHP.sup.R are effective for hydrogenation of unsaturated compounds. Cobalt complex [(PNHP.sup.Cy)Co(CH.sub.2SiMe.sub.3)]BAr.sup.F.sub.4 (PNHP.sup.Cy=bis[2-(dicyclohexylphosphino)ethyl]amine, BAr.sup.F.sub.4=B(3,5-(CF.sub.3).sub.2C.sub.6H.sub.3).sub.4)) was prepared and used with hydrogen for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (25-60.degree. C., 1-4 atm H.sub.2). Nickel complex [(PNHP.sup.Cy)Ni(H)]BPh.sub.4 was used for hydrogenation of styrene and 1-octene under mild conditions. (PNP.sup.Cy)Ni(H) was used for hydrogenating alkenes.

Dense gamma-ray and pair creation using ultra-intense lasers

NASA Astrophysics Data System (ADS)

Liang, Edison; Lo, Willie; Hasson, Hannah; Dyer, Gilliss; Clarke, Taylor; Fasanelli, Fabio; Yao, Kelly; Marchenka, Ilija; Henderson, Alexander; Dashko, Andriy; Zhang, Yuling; Ditmire, Todd

2016-10-01

We report recent results of gamma-ray and e +e- pair creation experiments using the Texas Petawatt laser (TPW) in Austin and the Trident laser at LANL irradiating solid high-Z targets. In addition to achieving record high densities of emerging gamma-rays and pairs at TPW, we measured in detail the spectra of hot electrons, positrons, and gamma-rays, and studied their spectral variation with laser and target parameters. A new type of gamma-ray spectrometer, called the scintillator attenuation spectrometer (SAS), was successfully demonstrated in Trident experiments in 2015. We will discuss the design and results of the SAS. Preliminary results of new experiments at TPW carried out in the summer of 2016 will also be presented.

Synthesis, spectroscopic, molecular structure, antioxidant, antimicrobial and antitumor behavior of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of O2N type tridentate chromone-2-carboxaldehyde Schiff's base ligand

NASA Astrophysics Data System (ADS)

Ammar, Reda A.; Alaghaz, Abdel-Nasser M. A.; Zayed, Mohamed E.; Al-Bedair, Lamia A.

2017-08-01

Tridentate Schiff's base (HL) ligand was synthesized via condensation of salicylaldehyde and 3-hydroxypyridin-2-yliminomethyl-4H-chromen-4-one and their corresponding Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. The isolated solid complexes were characterized by elemental analyses, molar conductance, spectral (IR, UV-Vis, 1H NMR), magnetic moment, EPR, and thermal measurements. The IR spectra showed that HL was coordinated to the metal ions in tridentate manner with O2N donor sites of the azomethine N, deprotonated phenolic-OH and carbonyl-O. The activation of thermodynamic parameters are calculated using Coast-Redfern and Horowitz-Metzger (HM). The octahedral geometry of the complexes is confirmed using DFT method from DMOL3 calculations, UV-Vis and magnetic moment measurements, ESR and ligand field parameters. Antioxidant activities have also been performed for all the compounds. The investigated ligand and metal complexes were screened for their in-vitro antimicrobial activities against different types of fungal and bacterial strains. The resulting data assert on the inspected compounds as a highly promising bactericides and fungicides. The antitumor activities of all inspected compounds were evaluated towards human liver Carcinoma (HepG2) cell line.

The genetic control of milling yield, dough rheology and baking quality of wheat.

PubMed

Kuchel, H; Langridge, P; Mosionek, L; Williams, K; Jefferies, S P

2006-05-01

Improving the end-use quality of wheat is a key target for many breeding programmes. With the exception of the relationship between glutenin alleles and some dough rheological characters, knowledge concerning the genetic control of wheat quality traits is somewhat limited. A doubled haploid population produced from a cross between two Australian cultivars 'Trident' and 'Molineux' has been used to construct a linkage map based largely on microsatellite molecular makers. 'Molineux' is superior to 'Trident' for a number of milling, dough rheology and baking quality characteristics, although by international standards 'Trident' would still be regarded as possessing moderately good end-use quality. This population was therefore deemed useful for investigation of wheat end-use quality. A number of significant QTL identified for dough rheological traits mapped to HMW and LMW glutenin loci on chromosomes 1A and 1B. However, QTL associated with dough strength and loaf volume were also identified on chromosome 2A and a significant QTL associated with loaf volume and crumb quality was identified on chromosome 3A. A QTL for flour protein content and milling yield was identified on chromosome 6A and a QTL associated with flour colour reported previously on chromosome 7B was confirmed in this population. The detection of loci affecting dough strength, loaf volume and flour protein content may provide fresh opportunities for the application of marker-assisted selection to improve bread-making quality.

Exp 36 Patch Final

NASA Image and Video Library

2012-08-10

ISS036-S-001 (January 2012) --- The dynamic design of the Expedition 36 patch portrays the International Space Station?s (ISS) iconic solar arrays. The slanted angles denote a kinetic energy leading from the Earth in the lower right to the upper left tip of the triangular shape of the patch, representing the infinite scientific research, education, and long-duration spaceflight capabilities the ISS provides with each mission, as well as our goal for future exploration beyond the Space Station. The numbers 3 and 6 harmoniously intertwine to form expedition number 36 and its gray coloration signifies the unity and neutrality among all of the international partners of the ISS. The blue and gold color scheme of the patch represents the subtle way the central gold orbit wraps around the number 36 to form a trident at its lower right tip. The trident also symbolizes the sea, air, and land, all of which make up the Earth from where the trident originates in the design. The NASA insignia design for shuttle and space station flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the form of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, it will be publicly announced. Photo credit: NASA

Katmai volcanic cluster and the great eruption of 1912

USGS Publications Warehouse

Hildreth, W.; Fierstein, J.

2000-01-01

In June 1912, the world's largest twentieth century eruption broke out through flat-lying sedimentary rocks of Jurassic age near the base of Trident volcano on the Alaska Peninsula. The 60 h ash-flow and Plinian eruptive sequence excavated and subsequently backfilled with ejecta a flaring funnel-shaped vent since called Novarupta. The vent is adjacent to a cluster of late Quaternary stratocones and domes that have released about 140 km3 of magma in the past 150 k.y. Although the 1912 vent is closest to the Trident group and is also close to Mageik and Griggs volcanoes, it was the summit of Mount Katmai, 10 km east of Novarupta, that collapsed during the eruption to form a 5.5 km3 caldera. Many earthquakes, including 14 in the range M 6-7, took place during and after the eruption, releasing 250 times more seismic energy than the 1991 caldera-forming eruption of the Philippine volcano, Pinatubo. The contrast in seismic behavior may reflect the absence of older caldera faults at Mount Katmai, lack of upward (subsidence opposing) magma flow owing to lateral magma withdrawal in 1912, and the horizontally stratified structure of the thick shale-rich Mesozoic basement. The Katmai caldera compensates for only 40% of the 13 km3 of 1912 magma erupted, which included 7-8 km3 of slightly zoned high-silica rhyolite and 4.5 km3 of crystal-rich dacite that grades continuously into 1 km3 of crystal-rich andesite. We have now mapped, sampled, and studied the products of all 20 components of the Katmai volcanic cluster. Pyroxene dacite and silicic andesite predominate at all of them, and olivine andesite is also common at Griggs, Katmai, and Trident volcanoes, but basalt and rhyodacite have erupted only at Mount Katmai. Rhyolite erupted only in 1912 and is otherwise absent among Quaternary products of the cluster. Pleistocene products of Mageik and Trident and all products of Griggs are compositionally distinguishable from those of 1912 at Novarupta. Holocene products of Mount Martin and Trident are closer in composition to the andesite-dacite array of 1912, but they reveal consistent differences. The affinity of the 1912 suite is closest with the array of products erupted by the Southwest Katmai cone, the edifice that had produced the only pre-1912 rhyodacite as well as the largest prehistoric Plinian eruption in the cluster. It is doubtful that any 1912 magma had been stored beneath Novarupta or Trident, and there is no evidence that more than one magma chamber erupted in 1912. Despite a compositional gap separating the aphyric rhyolite from the very crystal-rich andesite-dacite continuum, isotopic and chemical affinities linking all the 1912 ejecta and the continuity of all those ejecta in magmatic temperature and oxygen fugacity suggest that the rhyolite originated principally by incremental upward expulsion of interstitial melt from subjacent andesite-dacite mush. A large reservoir of such hot crystal mush is required both as the residue of rhyolitic melt separation and as a proximate heat source to thermally sustain the nearly aphyric condition of the overlying rhyolite. A model is presented for a unitary zoned chamber beneath Mount Katmai.

[A web-based Colour Vision Test as a Tool for Qualitative Evaluation of Pseudoisochromatic Pflüger Trident Colour Plates].

PubMed

Kuchenbecker, Joern

2018-05-22

Pseudoisochromatic colour plates are constructed according to specific principles. They can be very different in quality. To check the diagnostic quality, they have to be tested on a large number of subjects, but this procedure is can be tedious and expensive. Therefore, the use of a standardised web-based test is recommended. Eight Pflüger trident colour plates (including 1 demo plate) according to the Velhagen edition of 1980 were digitised and inserted into a web-based colour vision test (www.color-vision-test.info). After visual display calibration and 2 demonstrations of the demo plate (#1) to introduce the test procedure, 7 red-green colour plates (#3, 4, 10, 11, 12, 13, 16) were presented in a randomised order in 3 different randomised positions each for 10 seconds. The user had to specify the opening of the Pflüger trident by a mouse click or arrow keys. 6360 evaluations of all plates from 2120 randomised subjects were included. Without error, the detection rates of the plates were between 72.2% (plate #3) and 90.7% (plate #16; n = 6360). With an error number of 7 errors per test, the detection rates of the plates were between 21.6% (plate #3) and 67.7% (plate #16; n = 1556). If an error number of 14 errors was used, the detection rates of the plates were between 10.9% (plate #11) and 40.1% (plate #16; n = 606). Plate #16 showed the highest detection rate - at zero error number as well as at the 7 and 14 error limit. The diagnostic quality of this plate was low. The colourimetric data were improved. The detection rate was then significantly lower. The differences in quality of pseudoisochromatic Pflüger trident colour plates can be tested without great effort using a web-based test. Optimisation of a poor quality colour plate can then be carried out. Georg Thieme Verlag KG Stuttgart · New York.

Cu-free 1,3-dipolar cycloaddition click reactions to form isoxazole linkers in chelating ligands for fac-[M(I)(CO)3]+ centers (M = Re, 99mTc).

PubMed

Bottorff, Shalina C; Kasten, Benjamin B; Stojakovic, Jelena; Moore, Adam L; MacGillivray, Leonard R; Benny, Paul D

2014-02-17

Isoxazole ring formation was examined as a potential Cu-free alternative click reaction to Cu(I)-catalyzed alkyne/azide cycloaddition. The isoxazole reaction was explored at macroscopic and radiotracer concentrations with the fac-[M(I)(CO)3](+) (M = Re, (99m)Tc) core for use as a noncoordinating linker strategy between covalently linked molecules. Two click assembly methods (click, then chelate and chelate, then click) were examined to determine the feasibility of isoxazole ring formation with either alkyne-functionalized tridentate chelates or their respective fac-[M(I)(CO)3](+) complexes with a model nitrile oxide generator. Macroscale experiments, alkyne-functionalized chelates, or Re complexes indicate facile formation of the isoxazole ring. (99m)Tc experiments demonstrate efficient radiolabeling with click, then chelate; however, the chelate, then click approach led to faster product formation, but lower yields compared to the Re analogues.

Interferometric Synthetic Aperture radar studies of Alaska volcanoes

USGS Publications Warehouse

Lu, Zhong; Wicks, Charles W.; Dzurisin, Daniel; Power, John A.; Thatcher, Wayne R.; Masterlark, Timothy

2003-01-01

In this article, we summarize our recent InSAR studies of 13 Alaska volcanoes, including New Trident, Okmok, Akutan, Kiska, Augustine, Westdahl, Peulik, Makushin, Seguam, Shishaldin, Pavlof, Cleveland, and Korovin volcanoes.

NMOS contact resistance reduction with selenium implant into NiPt silicide

NASA Astrophysics Data System (ADS)

Rao, K. V.; Khaja, F. A.; Ni, C. N.; Muthukrishnan, S.; Darlark, A.; Lei, J.; Peidous, I.; Brand, A.; Henry, T.; Variam, N.; Erokhin, Y.

2012-11-01

A 25% reduction in NMOS contact resistance (Rc) was achieved by Selenium implantation into NiPt silicide film in VIISta Trident high-current single-wafer implanter. The Trident implanter is designed for shallow high-dose implants with high beam currents to maintain high throughput (for low CoO), with improved micro-uniformity and no energy contamination. The integration of Se implant was realized using a test chip dedicated to investigating silicide/junction related electrical properties and testable after silicidation. The silicide module processes were optimized, including the pre-clean (prior to RF PVD NiPt dep) and pre- and post-implant anneals. A 270°C soak anneal was used for RTP1, whereas a msec laser anneal was employed for RTP2 with sufficient process window (800-850°C), while maintaining excellent junction characteristics without Rs degradation.

Laser-Launched Flyer Plates and Direct Laser Shocks for Dynamic Material Property Measurements

NASA Astrophysics Data System (ADS)

Paisley, D. L.; Swift, D. C.; Johnson, R. P.; Kopp, R. A.; Kyrala, G. A.

2002-07-01

The Trident laser at Los Alamos was used to impart known and controlled shocks in various materials by launching flyer plates or by irradiating the sample directly. Materials investigated include copper, gold, NiTi, SS316, and other metals and alloys. Tensile spall strength, elastic-plastic transition, phase boundaries, and equation of state can be determined with small samples. Using thin samples (0.1 - 1.0 mm thick) as targets, high pressure gradients can be generated with relatively low pressures, resulting in high tensile strain rates (105 to 108 s-1). Free surface and interface velocities are recorded with point- and line-imaging VISARs. The flexible spatial and temporal pulse profiles of Trident, coupled with the use of laser-launched flyer plates, provides capabilities which complement experiments conducted using gas guns and tensile bars.

Theoretical study of mixed MLaX(4) (M = Na, K, Cs; X = F, Cl, Br, I) rare earth/alkali metal halide complexes.

PubMed

Groen, Cornelis Petrus; Oskam, Ad; Kovács, Attila

2003-02-10

The structure, bonding, and vibrational properties of the mixed MLaX(4) (M = Na, K, Cs; X = F, Cl, Br, I) rare earth/alkali metal halide complexes have been studied using the MP2 method in conjunction with polarized triple-zeta valence basis sets and quasi-relativistic effective core potentials for the heavy atoms. From the three characteristic structures, possessing 1- (C(3)(v)), 2- (C(2)(v)), or 3-fold coordination (C(3)(v)) between the alkali metal and the bridging halide atoms, the bi- and tridentate forms are stable isomers with close dissociation energies. In general, for the complexes existing of lighter alkali metals and halogens, the bidentate structure corresponds to the global minimum of the potential energy surface, while the heavier analogues favor the tridentate structure. At experimentally relevant temperatures (T > 800 K), however, the isomerization entropy leads to a domination of the bidentate structures over the tridentate forms for all complexes. An important effect of the size of the alkali metal is manifested in the larger stabilities of the K and Cs complexes. The natural atomic charges are in agreement with strong electrostatic interactions in the title complexes. The marginal covalent contributions show a slight increasing trend in the heavier analogues. The calculated vibrational data indicate that infrared spectroscopy may be an effective tool for experimental investigation and characterization of MLaX(4) molecules.

TRIDENT 1 third stage motor separation system

NASA Technical Reports Server (NTRS)

Welch, B. H.; Richter, B. J.; Sue, P.

1977-01-01

The third stage engine separation system has shown through test and analysis that it can effectively and reliably perform its function. The weight of the hardware associated with this system is well within the targeted value.

Titanium(IV) isopropoxide mediated solution phase reductive amination on an automated platform: application in the generation of urea and amide libraries.

PubMed

Bhattacharyya, S; Fan, L; Vo, L; Labadie, J

2000-04-01

Amine libraries and their derivatives are important targets for high throughput synthesis because of their versatility as medicinal agents and agrochemicals. As a part of our efforts towards automated chemical library synthesis, a titanium(IV) isopropoxide mediated solution phase reductive amination protocol was successfully translated to automation on the Trident(TM) library synthesizer of Argonaut Technologies. An array of 24 secondary amines was prepared in high yield and purity from 4 primary amines and 6 carbonyl compounds. These secondary amines were further utilized in a split synthesis to generate libraries of ureas, amides and sulfonamides in solution phase on the Trident(TM). The automated runs included 192 reactions to synthesize 96 ureas in duplicate and 96 reactions to synthesize 48 amides and 48 sulfonamides. A number of polymer-assisted solution phase protocols were employed for parallel work-up and purification of the products in each step.

Controlling the oxidation of bis-tridentate cobalt(ii) complexes having bis(2-pyridylalkyl)amines: ligand vs. metal oxidation.

PubMed

Anjana, S; Donring, S; Sanjib, P; Varghese, B; Murthy, Narasimha N

2017-08-22

Two bis-tridentate chelated cobalt(ii) complexes, which differ in the ligand structure by a methylene group, activate molecular oxygen (O 2 ), and give different oxidation products. The O 2 reaction of [Co II (pepma) 2 ] 2+ (1) with unsymmetrical 2-(2-pyridyl)-N-(2-pyridylmethyl)ethanamine (pepma) results in ligand oxidation, to the corresponding Co(ii) imine complex [Co II (pepmi) 2 ] 2+ (2). Contrastingly, the Co(ii) complex [Co II (bpma) 2 ] 2+ (3) of similar symmetrical bis(2-pyridylmethyl)amine (bpma), undergoes metal oxidation, yielding a cobalt(iii) complex, [Co III (bpma) 2 ] 2+ (4). The reversibility of the amine to imine conversion and the stability of the Co(ii) imine complex (2) are investigated. Furthermore, the solution dynamics of Co(ii) complexes are highlighted with the help of paramagnetic 1 H-NMR spectroscopy.

Effect of the temporal laser pulse asymmetry on pair production processes during intense laser-electron scattering

NASA Astrophysics Data System (ADS)

Hojbota, C. I.; Kim, Hyung Taek; Kim, Chul Min; Pathak, V. B.; Nam, Chang Hee

2018-06-01

We investigate the effects of laser pulse shape on strong-field quantum electrodynamics (QED) processes during the collision between a relativistic electron beam and an intense laser pulse. The interplay between high-energy photon emission and two pair production processes, i.e. nonlinear Breit–Wheeler (BW) and Trident, was investigated using particle-in-cell simulations. We found that the temporal evolution of these two processes could be controlled by using laser pulses with different degrees of asymmetry. The temporal envelope of the laser pulse can significantly affect the number of pairs coming from the Trident process, while the nonlinear BW process is less sensitive to it. This study shows that the two QED processes can be examined with state-of-the-art petawatt lasers and the discrimination of the two pair creation processes is feasible by adjusting the temporal asymmetry of the colliding laser pulse.

Preparation and first biological evaluation of novel Re-188/Tc-99m peptide conjugates with substance-P.

PubMed

Smilkov, Katarina; Janevik, Emilija; Guerrini, Remo; Pasquali, Micol; Boschi, Alessandra; Uccelli, Licia; Di Domenico, Giovanni; Duatti, Adriano

2014-09-01

New (188)Re and (99m)Tc peptide conjugates with substance- P (SP) were prepared and biologically evaluated. The radiopharmaceuticals have been labelled with the [M≡N](2+) (M=(99m)Tc, (188)Re) core using a combination of π-donor tridentate and π-acceptor monodentate ancillary ligands. The new radiopharmaceuticals have been prepared through a two-step reaction by simultaneous addition of the tridentate and monodentate ligands to a vial containing a preformed [M≡N](2+) core. The tridentate ligand was formed by linking two cysteine residues to the terminal arginine of the undecapeptide SP, whereas the monodentate ligand was a tertiary phosphine. The preparation of the corresponding Re-188 derivative required developing a more complex chemical procedure to obtain the [Re≡N](2+) core in satisfactory yields. Characterization of the resulting products was obtained by chromatographic methods. Biological evaluation was performed for both Tc-99m and Re-188 derivatives by in-vitro studies on isolated cells expressing NK1-receptors. In-vivo imaging in mice was carried out using a small-animal YAP(S)PET tomograph. New Tc-99m and Re-188 peptide radiopharmaceuticals with SP have been prepared in high-yield and with high-specific activity. Both Tc-99m and Re-188 peptide radioconjugates exhibit high affinity for NK1 receptors, thus giving further evidence to the empirical rule that structurally related Tc-99m and Re-188 radiopharmaceuticals exhibit identical biological properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

Three-dimensional seismic velocity structure and earthquake relocations at Katmai, Alaska

USGS Publications Warehouse

Murphy, Rachel; Thurber, Clifford; Prejean, Stephanie G.; Bennington, Ninfa

2014-01-01

We invert arrival time data from local earthquakes occurring between September 2004 and May 2009 to determine the three-dimensional (3D) upper crustal seismic structure in the Katmai volcanic region. Waveforms for the study come from the Alaska Volcano Observatory's permanent network of 20 seismic stations in the area (predominantly single-component, short period instruments) plus a densely spaced temporary array of 11 broadband, 3-component stations. The absolute and relative arrival times are used in a double-difference seismic tomography inversion to solve for 3D P- and S-wave velocity models for an area encompassing the main volcanic centers. The relocated hypocenters provide insight into the geometry of seismogenic structures in the area, revealing clustering of events into four distinct zones associated with Martin, Mageik, Trident-Novarupta, and Mount Katmai. The seismic activity extends from about sea level to 2 km depth (all depths referenced to mean sea level) beneath Martin, is concentrated near 2 km depth beneath Mageik, and lies mainly between 2 and 4 km depth below Katmai and Trident-Novarupta. Many new features are apparent within these earthquake clusters. In particular, linear features are visible within all clusters, some associated with swarm activity, including an observation of earthquake migration near Trident in 2008. The final velocity model reveals a possible zone of magma storage beneath Mageik, but there is no clear evidence for magma beneath the Katmai-Novarupta area where the 1912 eruptive activity occurred, suggesting that the storage zone for that eruption may have largely been evacuated, or remnant magma has solidified.

Semi- and thiosemicarbazide Mn(II) complexes: Characterization, DFT and biological studies

NASA Astrophysics Data System (ADS)

Yousef, T. A.; Alduaij, O. K.; Ahmed, Sara F.; Abu El-Reash, G. M.; El-Gammal, O. A.

2016-09-01

One NO and two NOS donor ligands have been prepared by addition ethanolic suspension of 2-hydrazino-2-oxo-N-phenyl-acetamide to phenyl isocyanate (H2PAPS), phenyl isothiocyanate (H2PAPT) and benzoyl isothiocyanate (H2PABT). The Mn (II) complexes were prepared from the chloride salt and characterized by conventional techniques. The isolated complexes were assigned the formulaes, [Mn(HPAPS)2], [Mn(HPAPT)Cl] and [Mn(HPABT)Cl(H2O)2], respectively. The IR study of ligands and their complexes shows that H2PAPS behaves as a mononegative tridentate via both CO of hydrazide moiety in keto and deprotonated enol form and CN (azomethine) due to enolization of CO cyanate moiety without deprotonation. H2PAPT behaves as mononegative tridentate via CO of hydrazide moiety, deprotonated thiol CS and NH group. Finally H2PABT behaves as mononegative tridentate via deprotonated enolized CO of hydrazide moiety, CO of benzoyl moiety and NH group. The IR spectra of ligands from DFT calculations are compared with those obtained experimentally. Also, HOMO, LUMO, the bond lengths, bond angles, and dipole moments have been calculated. The calculated HOMO-LUMO energy gap reveals that charge transfer occurs within the molecule. The binding energy values display the high stability of complexes. The kinetic and thermodynamic parameters were determined by Coats-Redfern and Horowitz-Metzger methods. The antibacterial activities were also tested against Bacillus subtilis and Escherichia coli bacteria. Finally, the antitumor activities of the Ligands and their Mn(II) complexes have been evaluated against liver (HePG2) and breast (MCF-7) cancer cells.

Solid-state thermolysis of a fac-rhenium(I) carbonyl complex with a redox non-innocent pincer ligand.

PubMed

Jurca, Titel; Chen, Wen-Ching; Michel, Sheila; Korobkov, Ilia; Ong, Tiow-Gan; Richeson, Darrin S

2013-03-25

The development of rhenium(I) chemistry has been restricted by the limited structural and electronic variability of the common pseudo-octahedral products fac-[ReX(CO)3L2] (L2 = α-diimine). We address this constraint by first preparing the bidentate bis(imino)pyridine complexes [(2,6-{2,6-Me2C6H3N=CPh}2C5H3N)Re(CO)3X] (X = Cl 2, Br 3), which were characterized by spectroscopic and X-ray crystallographic means, and then converting these species into tridentate pincer ligand compounds, [(2,6-{2,6-Me2C6H3N=CPh}2C5H3N)Re(CO)2X] (X = Cl 4, Br 5). This transformation was performed in the solid-state by controlled heating of 2 or 3 above 200 °C in a tube furnace under a flow of nitrogen gas, giving excellent yields (≥95 %). Compounds 4 and 5 define a new coordination environment for rhenium(I) carbonyl chemistry where the metal center is supported by a planar, tridentate pincer-coordinated bis(imino)pyridine ligand. The basic photophysical features of these compounds show significant elaboration in both number and intensity of the d-π* transitions observed in the UV/Vis spec tra relative to the bidentate starting materials, and these spectra were analyzed using time-dependent DFT computations. The redox nature of the bis(imino)pyridine ligand in compounds 2 and 4 was examined by electrochemical analysis, which showed two ligand reduction events and demonstrated that the ligand reduction shifts to a more positive potential when going from bidentate 2 to tridentate 4 (+160 mV for the first reduction step and +90 mV for the second). These observations indicate an increase in electrostatic stabilization of the reduced ligand in the tridentate conformation. Elaboration on this synthetic methodology documented its generality through the preparation of the pseudo-octahedral rhenium(I) triflate complex [(2,6-{2,6-Me2C6H3N=CPh}2C5H3N)Re(CO)2OTf] (7, 93 % yield). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simulating the productivity of desert woody shrubs in southwestern Texas

USDA-ARS?s Scientific Manuscript database

In the southwestern U.S., many rangelands have converted from native grasslands to woody shrublands dominated by creosotebush (Larrea tridentate) and honey mesquite (Prosopis glandulosa), threatening ecosystem health. Both creosotebush and mesquite have well-developed long root systems that allow t...

Laser-based fast-neutron spectroscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pomerantz, Ishay; Kishon, Itay; Kleinschmidt, Annika; Schanz, Victor A.; Tebartz, Alexandra; Fernández, Juan Carlos; Gautier, Donald C.; Johnson, Randall Philip; Shimada, Tsutomu; Wurden, Glen Anthony; Roth, Markus

2017-05-01

Great progress has been made in recent years in realizing compact, laser-based neutron generators. These devices, however, are inapplicable for conducting energy-resolved fast-neutron radiography because of the electromagnetic noise produced by the interaction of a strong laser field with matter. To overcome this limitation, we developed a novel neutron time-of-flight detector, largely immune to electromagnetic noise. The detector is based on plastic scintillator, only a few mm in size, which is coupled to a silicon photo-multiplier by a long optical fiber. I will present results we obtained at the Trident Laser Facility at Los Alamos National Laboratory during the summer of 2016. Using this detector, we recorded high resolution, low-background fast neutron spectra generated by the interaction of laser accelerated deuterons with Beryllium. The quality of these spectra was sufficient to resolve the unique neutron absorption spectra of different elements and thus it is the first demonstration of laser-based fast neutron spectroscopy. I will discuss how this achievement paves the way to realizing compact neutron radiography systems for research, security, and commercial applications.

Experimental analysis of insertion torques and forces of threaded and press-fit acetabular cups by means of ex vivo and in vivo measurements.

PubMed

Vogel, Danny; Rathay, Andreas; Teufel, Stephanie; Ellenrieder, Martin; Zietz, Carmen; Sander, Manuela; Bader, Rainer

2017-01-01

In THA a sufficient primary implant stability is the precondition for successful secondary stability. Industrial foams of different densities have been used for primary stability investigations. The aim of this study was to analyse and compare the insertion behaviour of threaded and press-fit cups in vivo and ex vivo using bone substitutes with various densities. Two threaded (Bicon Plus®, Trident® TC) and one press-fit cup (Trident PSL®) were inserted by orthopaedic surgeons (S1, S2) into 10, 20 and 31 pcf blocks, using modified surgical instruments allowing measurements of the insertion forces and torques. Furthermore, the insertion behaviour of two cups were analysed intraoperatively. Torques for the threaded cups increased while bone substitute density increased. Maximum insertion torques were observed for S2 with 102 Nm for the Bicon Plus® in 20 pcf blocks and 77 Nm for the Trident® TC in 31 pcf blocks, which compares to the in vivo measurement (85 Nm). The average insertion forces for the press-fit cup varied from 5.2 to 6.8 kN (S1) and 7.2-11.5 kN (S2) ex vivo. Intraoperatively an average insertion force of 8.0 kN was determined. Implantation behaviour was influenced by acetabular cup design, bone substitute and experience of the surgeon. No specific density of bone substitute could be favoured for ex vivo investigations on the implantation behaviour of acetabular cups. The use synthetic bone blocks of high density (31 pcf) led to problems regarding cup orientation and seating. Therefore, bone substitutes used should be critically scrutinized in terms of the comparability to the in vivo situation.

Dye molecular structure device open-circuit voltage correlation in Ru(II) sensitizers with heteroleptic tridentate chelates for dye-sensitized solar cells.

PubMed

Wu, Kuan-Lin; Li, Cheng-Hsuan; Chi, Yun; Clifford, John N; Cabau, Lydia; Palomares, Emilio; Cheng, Yi-Ming; Pan, Hsiao-An; Chou, Pi-Tai

2012-05-02

Dicarboxyterpyridine chelates with π-conjugated pendant groups attached at the 5- or 6-position of the terminal pyridyl unit were synthesized. Together with 2,6-bis(5-pyrazolyl)pyridine, these were used successfully to prepare a series of novel heteroleptic, bis-tridentate Ru(II) sensitizers, denoted as TF-11-14. These dyes show excellent performance in dye-sensitized solar cells (DSCs) under AM1.5G simulated sunlight at a light intensity of 100 mW cm(-2) in comparison with a reference device containing [Ru(Htctpy)(NCS)(3)][TBA](3) (N749), where H(3)tctpy and TBA are 4,4',4"-tricarboxy-2,2':6',2"-terpyridine and tetra-n-butylammonium cation, respectively. In particular, the sensitizer TF-12 gave a short-circuit photocurrent of 19.0 mA cm(-2), an open-circuit voltage (V(OC)) of 0.71 V, and a fill factor of 0.68, affording an overall conversion efficiency of 9.21%. The increased conjugation conferred to the TF dyes by the addition of the π-conjugated pendant groups increases both their light-harvesting and photovoltaic energy conversion capability in comparison with N749. Detailed recombination processes in these devices were probed by various spectroscopic and dynamics measurements, and a clear correlation between the device V(OC) and the cell electron lifetime was established. In agreement with several other recent studies, the results demonstrate that high efficiencies can also be achieved with Ru(II) sensitizers that do not contain thiocyanate ancillaries. This bis-tridentate, dual-carboxy anchor configuration thus serves as a prototype for future omnibearing design of highly efficient Ru(II) sensitizers suited for use in DSCs. © 2012 American Chemical Society

Preparation, spectral, X-ray powder diffraction and computational studies and genotoxic properties of new azo-azomethine metal chelates

NASA Astrophysics Data System (ADS)

Bitmez, Şirin; Sayin, Koray; Avar, Bariş; Köse, Muhammet; Kayraldız, Ahmet; Kurtoğlu, Mükerrem

2014-11-01

A new tridentate azo-azomethine ligand, N‧-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}methylidene]benzohydrazidemonohydrate, (sbH·H2O) (1), is prepared by condensation of benzohydrazide and 2-hydroxy-5-[(4-nitrophenyl)diazenyl]benzaldehyde (a) with treatment of a solution of diazonium salt of p-nitroaniline and 2-hydroxybenzaldehyde in EtOH. The five coordination compounds, [Co(sb)2]·4H2O (2), [Ni(sb)2]·H2O (3), [Cu(sb)2]·4H2O (4), [Zn(sb)2]·H2O (5) and [Cd(sb)2]·H2O (6) are prepared by reacting the Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with the ligand. The structures of the compounds are elucidated from the elemental analyses data and spectroscopic studies. It is found the ligand acts as a tridentate bending through phenolic and carbonyl oxygens and nitrogen atom of the Cdbnd Nsbnd group similar to the most of salicylaldimines. Comparison of the infrared spectra of the ligand and its metal complexes confirm that azo-Schiff base behaves as a monobasic tridentate ligand towards the central metal ion with an ONO donor sequence. Upon complexation with the ligand, the Cd(II), and Zn(II) ions form monoclinic structures, while Co(II), Cu(II) and Ni(II) ions form orthorhombic structures. Quantum chemical calculations are performed on tautomers and its metal chelates by using DFT/B3LYP method. Most stable tautomer is determined as tautomer (1a). The geometrical parameters of its metal chelates are obtained as theoretically. The NLO properties of tautomer (1a) and its metal complexes are investigated. Finally, the ligand and its metal complexes are assessed for their genotoxicity.

From microjoules to megajoules and kilobars to gigabars: probing matter at extreme states of deformation

NASA Astrophysics Data System (ADS)

Remington, Bruce A.

2014-10-01

Over the past 3 decades there has been an exponential increase in the newly emerging field of matter at extreme states of deformation and compression. This has been due to the confluence of new experimental facilities, new experimental techniques, new theory, and new multiscale simulation techniques. Regimes of science and research hitherto thought out of reach in terrestrial settings are now being accessed routinely. High energy lasers and pulsed power facilities are accessing high pressure macroscopic states of matter, and next generation light sources combined with smaller drive lasers are probing the quantum response of matter at the atomistic level. Combined, this gives multiscale experimental access of the properties and dynamics of matter from femtoseconds to microseconds and from kilobars to gigabars of pressure. There are a multitude of new regimes of science and research that these new developments make possible. Examples include planetary formation dynamics, asteroid and meteor impact dynamics, space hardware response to hypervelocity interplanetary dust impacts, reactor component response to prolonged exposure to radiation damage, advanced research into light weight armor, and capsule dynamics in inertial confinement fusion (ICF). I will review highlights and advances in this rapidly developing field of science and research, touching on experiments at a wide range of facilities (NIF, Z, Omega, Jupiter, Trident, Vulcan, Orion, LULI, LIL, Gekko, Shenguang, LCLS, DCS). I will also review a wide variety of sophisticated new experimental techniques being developed and new developments in theory and multiscale modeling. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Towards a Personalized Prescription Tool for Diabetic Treatment

DTIC Science & Technology

2015-05-18

for public release and sale ; its distribution is limited. U.S.N.A. --- Trident Scholar project report; no. 432 (2015) TOWARDS A...stroke, high blood pressure, blindness, kidney failure, and nervous symptom damage. Both type I and type II diabetes are currently treated with insulin

The Max Rover submersible is tested at the Trident pier, Port Canaveral

NASA Technical Reports Server (NTRS)

1997-01-01

Thomas Lippitt of NASA's Advanced Systems Development (ASD) laboratory observes robotic operations as Chris Nicholson, owner of Deep Sea Systems, and Bill Jones of NASA's ASD laboratory operate the unmanned robotic submersible recovery system, known as Max Rover, during a test of the system at the Trident Pier at Port Canaveral. The submersible is seen in the water with the Diver Operated Plug (DOP). Kennedy Space Center's solid rocket booster (SRB) retrieval team and ASD laboratory staff hope that the new robotic technology will make the process of inserting the plug safer and less strenuous. Currently, scuba divers manually insert the DOP into the aft nozzle of a jettisoned SRB 60 to 70 feet below the surface of the Atlantic Ocean. After the plug is installed, water is pumped out of the booster allowing it to float horizontally. It is then towed back to Hangar AF at Cape Canaveral Air Station for refurbishment. Deep Sea Systems of Falmouth, Mass., built the submersible for NASA.

Zn(II), Ni(II), Cu(II) and Pb(II) complexes of tridentate asymmetrical Schiff base ligands: Synthesis, characterization, properties and biological activity

NASA Astrophysics Data System (ADS)

Şahin, Mustafa; Koçak, Nuriye; Erdenay, Damla; Arslan, Uğur

2013-02-01

New asymmetrical tridentate Schiff base ligands were synthesized using 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde, 9-anthracenecarboxaldehyde. Schiff base ligands and their metal complexes were synthesised and characterized by using FT-IR, 1H NMR, 13C NMR, UV-Vis, XRD, ESR, elemental analysis and fluorescence studies. The antimicrobial activity of the ligands and their metal complexes were studied against Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, Streptococcus mutans RSHM 676, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853. The determination of the antibacterial activity was done using the broth microdilution methods. In general, it has been determined that the studied compounds have MIC values similar to Gram-positive and Gram-negative bacteria. It has been found that Ni, Pb, Zn derivatives of HL1A and ZnL2A has lower MIC values than ampicillin for P. aeruginosa ATCC 27853 strain.

Synthesis, characterization, electrical conductivity and luminescence properties of two copper(II) complexes with tridentate N2O chelating ligands containing imine bond

NASA Astrophysics Data System (ADS)

Gönül, İlyas; Ay, Burak; Karaca, Serkan; Şahin, Onur; Serin, Selahattin

2018-03-01

In the present study, we describe the synthesis and characterization of two tridentate N2O donor ligands, namely, (E)-2-(((2-(diethylamino)ethyl)imino)methyl)-6-methoxyphenol (HL1) and (E)-2-(((2-(diethylamino)ethyl)imino)methyl)-6-ethoxyphenol (HL2), and their copper(II) complexes, [Cu(L1)(CH3COO)] (1), [Cu(L2)(CH3COO)] (2). They have been synthesized under conventional methods and characterized by elemental analysis, FTIR, 1H and 13C NMR, ICP-OES, TGA and GC/MS analysis. For the morphological analysis field emission scanning electron microscopy (FESEM) was used. The geometry of the copper(II) complexes was determined by single crystal X-ray diffraction analysis. The copper(II) ions are in distorted square-pyramidal coordination environments. Complexes crystallize in monoclinic space group, P21/c. The electrical conductivity and luminescence properties of 1-2 have been investigated.

Models for predicting fuel consumption in sagebrush-dominated ecosystems

Treesearch

Clinton S. Wright

2013-01-01

Fuel consumption predictions are necessary to accurately estimate or model fire effects, including pollutant emissions during wildland fires. Fuel and environmental measurements on a series of operational prescribed fires were used to develop empirical models for predicting fuel consumption in big sagebrush (Artemisia tridentate Nutt.) ecosystems....

United States Naval Academy Summary of Research, Academic Departments 1989 - 1990

DTIC Science & Technology

1989-12-01

Ronda R., Assistant Professor, "Comment on ’ Plutarch on Young Children,’ by Valerie HAGAN, Kenneth J., Professor, "The English Influ- French...34 International Plutarch Society, American ence on American Naval Strategy," Trident Society, Philological Association Annual Meeting, Baltimore, Naval Reserve

On the structure of transition metals complexes with the new tridentate dye of thiazole series: Theoretical and experimental studies

NASA Astrophysics Data System (ADS)

Fizer, Maksym; Sidey, Vasyl; Tupys, Andrii; Ostapiuk, Yurii; Tymoshuk, Oleksandr; Bazel, Yaroslav

2017-12-01

The 1-[(5-Benzyl-1,3-thiazol-2-yl)diazenyl]naphthalene-2-ol (BnTAN) is a recently synthesized azo dye that can act as a tridentate ligand in complexes with transition metals. In a series of previous works, this analytical reagent was shown to be applicable for selective, reliable, express and relatively inexpensive determination of heavy metals in different objects through the spectrophotometric technique. Although the action of 1-(2-thiazolylazo)-2-naphthol (TAN) dyes as tridentate ligands has been suggested in the literature long time ago, due to the lack of experimental data, it was necessary to investigate the mechanism of formation and the structure of BnTAN complexes with the such transition metals as Cu(II), Zn(II) and Cd(II). Furthermore, the reactivity and properties of different acidity forms and conformers of BnTAN and related TAN dyes were not fully defined, so the determination of these properties by analysis of wavefunction was also necessary. Two standard spectrophotometric methods and voltammetric technique were used to determine the composition of complex of BnTAN with metals ions. All three experimental methods indicate that coordination ratio of metal:dye is equal to 1:2. Moreover, this study reports the stability and geometry of conformers of different forms (anionic/neutral/cationic) of BnTAN, along with a detailed analysis of electronic properties, reactivity and aromaticity of the most stable conformers of BnTAN forms. Each of the above forms has some difference in position of benzyl ring against the thiazole moiety, which is explained in terms of attraction and repulsion of these two fragments induced by partial atomic charges. The crucial influence of hydrogen bond and weak non-covalent interactions between naphthyl, aza- and thiazolyl fragments has been established. The quantum chemical calculations have shown that partial atomic charges of anionic, neutral and cationic forms can explain the reactivity of each BnTAN form, and have also clarified the mechanism of formation of metal complex through the connection of metal with phenol oxygen, thiazolyl nitrogen and one nitrogen of aza group - thus giving two five-membered metal-containing cycles and confirming that BnTAN acts as a tridentate ligand. The obtained results introduce novel and crucial information which can assist in understanding the mechanism of complex formation of BnTAN and display the strength and level of detail of applying quantum chemical methods to reveal the reactivity, energy properties, and electronic properties of this new dye.

Soil carbon and nitrogen in a Great Basin pinyon-juniper woodland: Influence of vegetation, burning, and time

Treesearch

B. M. Rau; D. W. Johnson; R. R. Blank; J. C. Chambers

2009-01-01

Much of the Great Basin, U.S. is currently dominated by sagebrush (Artemisia tridentate ssp. (Rydb.) Boivin) ecosystems. At intermediate elevations, sagebrush ecosystems are increasingly influenced by pinyon (Pinus monophylla Torr. & Frem.) and juniper (Juniperus osteosperma Torr.) expansion. Some...

Lexical Link Analysis (LLA) Application: Improving Web Service to Defense Acquisition Visibility Environment

DTIC Science & Technology

2015-09-30

and Knowledge Management (IC3K), Madeira , Portugal. Girvan, M., & Newman, M. E. J. (2002). Community structure in social and biological networks...Trident Warrior 08 exercise. In KDIR, Madeira , Portugal, INSTICC Press. Zhao, Y., Gallup, S.P., & MacKinnon, D.J. (2010). Towards real-time program

Trident Warrior Buoy Testing

DTIC Science & Technology

2013-09-30

the data to track swell events, accurately model swell refraction, and use the data to drive surf -forecasting and other nearshore models (e.g...Temperature (SST). • Addition of a 8GB Micro-SD card for on board time series storage (can be unpopulated or disabled ). • A complete rewrite of the

Department of Defense Annual Report Fiscal Year 1981,

DTIC Science & Technology

1980-01-29

and a small West African naval patrol "shows the flag" using ports such as Cotonou , as well as Luanda. Other countries have resisted Soviet efforts...breakthrough. The first submarine finished conversion in December 1978, and the SSBN was deployed with the TRIDENT I missile in October 1979; program

Lexical Link Analysis Application: Improving Web Service to Acquisition Visibility Portal

DTIC Science & Technology

2013-09-30

during the Empire Challenge 2008 and 2009 (EC08/09) field experiments and for numerous other field experiments of new technologies during Trident Warrior...Empirical Methods in Natural Language Processing and Very Large Corpora (EMNLP/ VLC -2000) (pp. 63–70). Retrieved from http://nlp.stanford.edu/manning

Creative Work Careers: Pathways and Portfolios for the Creative Economy

ERIC Educational Resources Information Center

Ashton, Daniel

2015-01-01

This article examines the career opportunities, challenges and trajectories of creative work. As part of the Creative Trident approach to creative workforce measurements, the embedded mode draws attention to creative work as it is undertaken outside of the creative industries. This article further considers and conceptualises the complex careers…

76 FR 24868 - Extension of Public Comment Period for the Draft Environmental Impact Statement for the Trident...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-03

... INFORMATION CONTACT: Ms. Christine Stevenson, EHW-2 EIS Project Manager, 1101 Tautog Circle, Silverdale, Washington 98315-1101; or http://ehw.nbkeis.com/ . SUPPLEMENTARY INFORMATION: This notice announces a fifteen... Manager, 1101 Tautog Circle, Silverdale, Washington 98315-1101. In addition, comments may be submitted...

76 FR 59161 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-National Warheads...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-23

...., Albuquerque, NM; Tetra Tech, Inc., Honolulu, HI; Trident Research, LLC, Austin, TX; Unified Design Corporation, Rockaway, NJ; and University of Texas at Austin, Austin, TX, have withdrawn as parties to this venture. No... DEPARTMENT OF JUSTICE Antitrust Division Notice Pursuant to the National Cooperative Research and...

Author Correction: Nanoscale control of competing interactions and geometrical frustration in a dipolar trident lattice.

PubMed

Farhan, Alan; Petersen, Charlotte F; Dhuey, Scott; Anghinolfi, Luca; Qin, Qi Hang; Saccone, Michael; Velten, Sven; Wuth, Clemens; Gliga, Sebastian; Mellado, Paula; Alava, Mikko J; Scholl, Andreas; van Dijken, Sebastiaan

2017-12-12

The original version of this article contained an error in the legend to Figure 4. The yellow scale bar should have been defined as '~600 nm', not '~600 µm'. This has now been corrected in both the PDF and HTML versions of the article.

40 CFR 52.1396 - Federal implementation plan for regional haze.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: PPL Montana, LLC, Colstrip Power Plant, Units 1, 2; and PPL Montana, LLC, JE Corette Steam Electric... production plants: Ash Grove Cement, Montana City Plant; and Holcim (US) Inc. Cement, Trident Plant. This..., SO2 or NOX in excess of the following limitations, in pounds per million British thermal units (lb...

40 CFR 52.1396 - Federal implementation plan for regional haze.

Code of Federal Regulations, 2014 CFR

2014-07-01

...: PPL Montana, LLC, Colstrip Power Plant, Units 1, 2; and PPL Montana, LLC, JE Corette Steam Electric... production plants: Ash Grove Cement, Montana City Plant; and Holcim (US) Inc. Cement, Trident Plant. This..., SO2 or NOX in excess of the following limitations, in pounds per million British thermal units (lb...

Enforcing Ising-like magnetic anisotropy via trigonal distortion in the design of a W( v )–Co( ii ) cyanide single-chain magnet

DOE PAGES

Zhang, Yuan-Zhu; Dolinar, Brian S.; Liu, Shihao; ...

2018-01-01

A new octacyanotungstate( v ) singe chain magnet with an effective energy barrier of 39.7(3) cm −1 is achieved by enforcing Ising-like magnetic anisotropy via introduction of trigonal distortion with a fac -tridentate capping ligand.

Synthesis and Characterization of Copper Complexes with a Tridentate Nitrogen-Donor Ligand: An Integrated Research Experiment for Undergraduate Students

ERIC Educational Resources Information Center

Bussey, Katherine A.; Cavalier, Annie R.; Connell, Jennifer R.; Mraz, Margaret E.; Holderread, Ashley S.; Oshin, Kayode D.; Pintauer, Tomislav

2015-01-01

An integrated laboratory experiment applying concepts and techniques developed in organic chemistry, inorganic chemistry, and instrumental analysis is presented for use by students interested in undergraduate research. The experiment incorporates some advanced laboratory practices such as multistep organic synthesis and purification, detailed…

Navy Trident Submarine Conversion (SSGN) Program: Background and Issues for Congress

DTIC Science & Technology

2005-03-25

the SSGNs would be functional replacements for the James K. Polk (SSN-645) and the Kamehameha (SSBN-642) — two older-generation SSBNs that were...converted into SSNs specifically for supporting larger numbers of SOF personnel. The Polk was retired in 1999 at age 33; the Kamehameha was retired in

Navy Trident Submarine Conversion SSGN Program: Background and Issues for Congress

DTIC Science & Technology

2002-02-06

role, the SSGNs would be functional replacements for the James K. Polk (SSN-645) and the Kamehameha (SSBN-642) – 2 older-generation SSBNs that were...converted into SSNs specifically for supporting larger numbers of SOF personnel. The Polk was retired in 1999 at age 33; the Kamehameha , commissioned in

Navy Trident Submarine Conversion (SSGN) Program: Background and Issues for Congress

DTIC Science & Technology

2006-06-20

the Kamehameha (SSBN-642) — two older-generation SSBNs that were converted into SSNs specifically for supporting larger numbers of SOF personnel...The Polk was retired in 1999 at age 33; the Kamehameha was retired in 2002 at age 36. The report of the 2001 Quadrennial Defense Review, submitted to

Enforcing Ising-like magnetic anisotropy via trigonal distortion in the design of a W( v )–Co( ii ) cyanide single-chain magnet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yuan-Zhu; Dolinar, Brian S.; Liu, Shihao

A new octacyanotungstate( v ) singe chain magnet with an effective energy barrier of 39.7(3) cm −1 is achieved by enforcing Ising-like magnetic anisotropy via introduction of trigonal distortion with a fac -tridentate capping ligand.

DNA binding, antioxidant, cytotoxicity (MTT, lactate dehydrogenase, NO), and cellular uptake studies of structurally different nickel(II) thiosemicarbazone complexes: synthesis, spectroscopy, electrochemistry, and X-ray crystallography.

PubMed

Prabhakaran, R; Kalaivani, P; Huang, R; Poornima, P; Vijaya Padma, V; Dallemer, F; Natarajan, K

2013-02-01

Three new nickel(II) thiosemicarbazone complexes have been synthesized and characterized by analytical, spectral, and single-crystal X-ray diffraction studies. In complex 1, the ligand 2-hydroxy-1-naphthaldehydethiosemicarbazone coordinated as a monobasic tridentate donor, whereas in complexes 2 and 3, the ligands salicylaldehyde-4(N)-ethylthiosemicarbazone and 2-hydroxy-1-naphthaldehyde-4(N)-ethylthiosemicarbazone coordinated as a dibasic tridentate donor. The DNA binding ability of the complexes in calf thymus DNA was explored by absorption and emission titration experiments. The antioxidant property of the new complexes was evaluated to test their free-radical scavenging ability. In vitro cytotoxicity assays were performed for the new complexes in A549 and HepG2 cell lines. The new compounds overcome cisplatin resistance in the A549 cell line and they were also active in the HepG2 cell line. The cellular uptake study showed the accumulation of the complexes in tumor cells depended on the nature of the ligand attached to the nickel ion.

An easy one-pot synthesis of diverse 2,5-di(2-pyridyl)pyrroles: a versatile entry point to metal complexes of functionalised, meridial and tridentate 2,5-di(2-pyridyl)pyrrolato ligands.

PubMed

McSkimming, Alex; Diachenko, Vera; London, Rachel; Olrich, Kiara; Onie, C Jessica; Bhadbhade, Mohan M; Bucknall, Martin P; Read, Roger W; Colbran, Stephen B

2014-09-01

A wide variety of 2,5-di(2-pyridyl)pyrroles (dppHs) substituted at the C3 and C4 positions of the pyrrole core were obtained by direct condensation of a 2-pyridylcarboxaldehyde (2 equiv), an α-methylene ketone with at least one electron-withdrawing substituent and ammonium acetate. A novel 2,5-di(1,10-phenanthrolin-2-yl)pyrrole was also characterised. The dppHs provide a direct, quick entry to dipyridylpyrrolato (dpp(-) )-metal complexes. The meridial tridentate dpp(-) ligand is a useful anionic analogue of the terpyridyl ligand. The first (dpp)Ru complexes are described; the 3,4-substitution of the central pyrrole significantly perturbs the potentials of the redox processes of these complexes. A [(dpp)Ru(bpy)(MeCN)](+) (bpy=2,2'-bipyridine) complex is an electrocatalyst for the reductive disproportionation of carbon dioxide to carbon monoxide and the carbonate ion. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectral characterization of novel ternary zinc(II) complexes containing 1,10-phenanthroline and Schiff bases derived from amino acids and salicylaldehyde-5-sulfonates

NASA Astrophysics Data System (ADS)

Boghaei, Davar M.; Gharagozlou, Mehrnaz

2007-07-01

A series of new ternary zinc(II) complexes [Zn(L 1-10)(phen)], where phen is 1,10-phenanthroline and H 2L 1-10 = tridentate Schiff base ligands derived from the condensation of amino acids (glycine, L-phenylalanine, L-valine, L-alanine, and L-leucine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5-sulfonate), have been synthesized. The complexes were characterized by elemental analysis, IR, UV-vis, 1H NMR, and 13C NMR spectra. The IR spectra of the complexes showed large differences between νas(COO) and νs(COO), Δ ν ( νas(COO) - νs(COO)) of 191-225 cm -1, indicating a monodentate coordination of the carboxylate group. Spectral data showed that in these ternary complexes the zinc atom is coordinated with the Schiff base ligand acts as a tridentate ONO moiety, coordinating to the metal through its phenolic oxygen, imine nitrogen, and carboxyl oxygen, and also with the neutral planar chelating ligand, 1,10-phenanthroline, coordinating through nitrogens.

Synthesis, characterization and solid-state properties of [Zn(Hdmmthiol)2]\\cdot2H2O complex

NASA Astrophysics Data System (ADS)

Dagdelen, Fethi; Aydogdu, Yildirim; Dey, Kamalendu; Biswas, Susobhan

2016-05-01

The zinc(II) complex with tridentate thiohydrazone ligand have been prepared by metal template reaction. The metal template reaction was used to prepare the zinc (II) complex with tridentate thiohydrazone ligand. The reaction of diacetylmonoxime and, morpholine N-thiohydrazidewith Zn(OAc)2 \\cdot2H2O under reflux yielded the formation of the [Zn(Hdmmthiol )2]\\cdot2H2O complex. The complex was characterized by a combination of protocols including elemental analysis, UV+vis, FT-IR, TG and PXRD. The temperature dependence of the electrical conductivity and the optical property of the [Zn(Hdmmthiol )2] \\cdot2H2O complex is called H2dammthiol was studied. Powder X-ray diffraction (PXRD) method was used to investigate the crystal structure of the sample. The zinc complex was shown to be a member of the triclinic system. The zinc complex was determined to have n-type conductivity as demonstrated in the hot probe measurements. The complex was determined to display direct optical transition with band gaps of 2.52eV as determined by the optical absorption analysis.

Rhenium and technetium complexes that bind to amyloid-β plaques.

PubMed

Hayne, David J; North, Andrea J; Fodero-Tavoletti, Michelle; White, Jonathan M; Hung, Lin W; Rigopoulos, Angela; McLean, Catriona A; Adlard, Paul A; Ackermann, Uwe; Tochon-Danguy, Henri; Villemagne, Victor L; Barnham, Kevin J; Donnelly, Paul S

2015-03-21

Alzheimer's disease is associated with the presence of insoluble protein deposits in the brain called amyloid plaques. The major constituent of these deposits is aggregated amyloid-β peptide. Technetium-99m complexes that bind to amyloid-β plaques could provide important diagnostic information on amyloid-β plaque burden using Single Photon Emission Computed Tomography (SPECT). Tridentate ligands with a stilbene functional group were used to form complexes with the fac-[M(I)(CO)3](+) (M = Re or (99m)Tc) core. The rhenium carbonyl complexes with tridentate co-ligands that included a stilbene functional group and a dimethylamino substituent bound to amyloid-β present in human frontal cortex brain tissue from subjects with Alzheimer's disease. This chemistry was extended to make the analogous [(99m)Tc(I)(CO)3](+) complexes and the complexes were sufficiently stable in human serum. Whilst the lipophilicity (log D7.4) of the technetium complexes appeared ideally suited for penetration of the blood-brain barrier, preliminary biodistribution studies in an AD mouse model (APP/PS1) revealed relatively low brain uptake (0.24% ID g(-1) at 2 min post injection).

Infrared Multiple Photon Dissociation Spectroscopy of Sodium and Potassium Chlorate Anions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryan P. Dain; Christopher M. Leavitt; Jos Oomens

2010-01-01

The structures of gas-phase, metal chlorate anions with the formula [M(ClO3)2]-, M=Na and K, were determined using tandem mass spectrometry and infrared multiple photon dissociation (IRMPD) spectroscopy. Structural assignments for both anions are based on comparisons of the experimental vibrational spectra for the two species to those predicted by density functional theory and involve conformations that feature either bidentate or tridentate coordination of the cation by chlorate. Our results strongly suggest that a structure in which both chlorate anions are bidentate ligands is preferred for [Na(ClO3)2]-. However, for [K(ClO3)2]- the best agreement between experimental and theoretical spectra is obtained frommore » a composite of predicted spectra for which the chlorate anions are either both bidentate or both tridentate ligands. In general, we find that the overall accuracy of DFT calculations for prediction of IR spectra is dependent on both functional and basis set, with best agreement achieved using frequencies generated at the B3LYP/6-311+g(3df) level of theory.« less

Infrared multiple photon dissociation spectroscopy of sodium and potassium chlorate anions.

PubMed

Dain, Ryan P; Leavitt, Christopher M; Oomens, Jos; Steill, Jeffrey D; Groenewold, Gary S; Van Stipdonk, Michael J

2010-01-01

The structures of gas-phase, metal chlorate anions with the formula [M(ClO(3))(2)](-), M = Na and K, were determined using tandem mass spectrometry and infrared multiple photon dissociation (IRMPD) spectroscopy. Structural assignments for both anions are based on comparisons of the experimental vibrational spectra for the two species with those predicted by density functional theory (DFT) and involve conformations that feature either bidentate or tridentate coordination of the cation by chlorate. Our results strongly suggest that a structure in which both chlorate anions are bidentate ligands is preferred for [Na(ClO(3))(2)](-). However, for [K(ClO(3))(2)](-) the best agreement between experimental and theoretical spectra is obtained from a composite of predicted spectra for which the chlorate anions are either both bidentate or both tridentate ligands. In general, we find that the overall accuracy of DFT calculations for prediction of IR spectra is dependent on both functional and basis set, with best agreement achieved using frequencies generated at the B3LYP/6-311+g(3df) level of theory. Copyright 2009 John Wiley & Sons, Ltd.

Synthesis and structures of a pincer-type rhodium(iii) complex: reactivity toward biomolecules.

PubMed

Milutinović, Milan M; Bogojeski, Jovana V; Klisurić, Olivera; Scheurer, Andreas; Elmroth, Sofi K C; Bugarčić, Živadin D

2016-10-04

A novel rhodium(iii) complex [Rh III (H 2 L tBu )Cl 3 ] (1) (H 2 L tBu = 2,6-bis(5-tert-butyl-1H-pyrazol-3-yl)pyridine) containing a pincer type, tridentate nitrogen-donor chelate system was synthesized. Single crystal X-ray structure analysis revealed that 1 crystallizes in the orthorhombic space group Pbcn with a = 20.7982(6), b = 10.8952(4), c = 10.9832(4) Å, V = 2488.80(15) Å 3 , and eight molecules in the unit cell. The rhodium center in the complex [Rh III (H 2 L tBu )Cl 3 ] (1) is coordinated in a slightly distorted octahedral geometry by the tridentate N,N,N-donor and three chloro ligands, adopting a mer arrangement with an essentially planar ligand skeleton. Due to the tridentate coordination of the N,N,N-donor, the central nitrogen atom N1 is located closer to the Rh III center. The reactivity of the synthesized complex toward small biomolecules (l-methionine (l-Met), guanosine-5'-monophosphate (5'-GMP), l-histidine (l-His) and glutathione (GSH)) and to a series of duplex DNAs and RNA was investigated. The order of reactivity of the studied small biomolecules is: 5'-GMP > GSH > l-Met > l-His. Duplex RNA reacts faster with the [Rh III (H 2 L tBu )Cl 3 ] complex than duplex DNA, while shorter duplex DNA (15mer GG) reacts faster compared with 22mer GG duplex DNA. In addition, a higher reactivity is achieved with a DNA duplex with a centrally located GG-sequence than with a 22GTG duplex DNA, in which the GG-sequence is separated by a T base. Furthermore, the interaction of this metal complex 1 with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) was examined by absorption (UV-Vis) and emission spectral studies (EthBr displacement studies). Overall, the studied complex exhibited good DNA and BSA interaction ability.

Common raven occurrence in relation to energy transmission line corridors transiting human-altered sagebrush steppe

USGS Publications Warehouse

Coates, Peter S.; Howe, Kristy B.; Casazza, Michael L.; Delehanty, David J.

2014-01-01

Energy-related infrastructure and other human enterprises within sagebrush steppe of the American West often results in changes that promote common raven (Corvus corax; hereafter, raven) populations. Ravens, a generalist predator capable of behavioral innovation, present a threat to many species of conservation concern. We evaluate the effects of detailed features of an altered landscape on the probability of raven occurrence using extensive raven survey (n= 1045) and mapping data from southern Idaho, USA. We found nonlinear relationships between raven occurrence and distances to transmission lines, roads, and facilities. Most importantly, raven occurrence was greater with presence of transmission lines up to 2.2 km from the corridor.We further explain variation in raven occurrence along anthropogenic features based on the amount of non-native vegetation and cover type edge, such that ravens select fragmented sagebrush stands with patchy, exotic vegetative introgression. Raven occurrence also increased with greater length of edge formed by the contact of big sagebrush (Artemisia tridentate spp.) with non-native vegetation cover types. In consideration of increasing alteration of sagebrush steppe, these findings will be useful for planning energy transmission corridor placement and other management activities where conservation of sagebrush obligate species is a priority.

Ion Heating of Plasma to Warm Dense Matter Conditions for the study of High-Z/Low-Z Mixing

NASA Astrophysics Data System (ADS)

Roycroft, R.; Dyer, G. M.; McCary, E.; Wagner, C.; Bernstein, A.; Ditmire, T.; Albright, B. J.; Fernandez, J. C.; Bang, W.; Bradley, P. A.; Gautier, D. C.; Hamilton, C. E.; Palaniyappan, S.; Santiago Cordoba, M. A.; Vold, E. L.; Yin, L.; Hegelich, B. M.

2016-10-01

The evolution of the interface between a light and heavy material isochorically heated to warm dense matter conditions is important to the understanding of electrostatic effects on the hydrodynamic models of fluid mixing. In recent experiments at the Trident laser facility, the target, containing a high Z and a low Z material, is heated to around 1eV by laser accelerated aluminum ions. In preparation for continued mixing experiments, we have recently heated aluminum to 20eV by laser accelerated protons on the Texas Petawatt Laser. We fielded a streaked optical pyrometer to measure surface temperature. The pyrometer images the rear surface of a heated target on a sub-nanosecond timescale with 400nm blackbody emissions. This poster presents the details of the experimental setup and pyrometer design, as well as results of ion and proton heating of aluminum targets, and ion heating of high-Z/low-Z integrated targets. Supported by NNSA cooperative agreement DE-NA0002008, the DoE through the LANL LDRD program, the DARPA PULSE program (12-63- PULSE-FP014), and the Air Force Office of Scientific Research (FA9550-14-1-0045).

Weibel instability mediated collisionless shocks using intense laser-driven plasmas

NASA Astrophysics Data System (ADS)

Palaniyappan, Sasikumar; Fiuza, Federico; Huang, Chengkun; Gautier, Donald; Ma, Wenjun; Schreiber, Jorg; Raymer, Abel; Fernandez, Juan; Shimada, Tom; Johnson, Randall

2017-10-01

The origin of cosmic rays remains a long-standing challenge in astrophysics and continues to fascinate physicists. It is believed that ``collisionless shocks'' - where the particle Coulomb mean free path is much larger that the shock transition - are a dominant source of energetic cosmic rays. These shocks are ubiquitous in astrophysical environments such as gamma-ray bursts, supernova remnants, pulsar wind nebula and coronal mass ejections from the sun. A particular type of electromagnetic plasma instability known as Weibel instability is believed to be the dominant mechanism behind the formation of these collisionless shocks in the cosmos. The understanding of the microphysics behind collisionless shocks and their particle acceleration is tightly related with nonlinear basic plasma processes and remains a grand challenge. In this poster, we will present results from recent experiments at the LANL Trident laser facility studying collisionless shocks using intense ps laser (80J, 650 fs - peak intensity of 1020 W/cm2) driven near-critical plasmas using carbon nanotube foam targets. A second short pulse laser driven protons from few microns thick gold foil is used to radiograph the main laser-driven plasma. Work supported by the LDRD program at LANL.

Weibel instability mediated collisionless shocks using intense laser-driven plasmas

NASA Astrophysics Data System (ADS)

Palaniyappan, Sasi; Huang, Chengkun; Gautier, Donald; Fernandez, Juan; Ma, Wenjun; Schreiber, Jorg; LANL Collaboration; LMU Team

2016-10-01

The origin of cosmic rays remains a long-standing challenge in astrophysics and continues to fascinate physicists. It is believed that ``collisionless shocks'' - where the particle Coulomb mean free path is much larger that the shock transition - are a dominant source of energetic cosmic rays. These shocks are ubiquitous in astrophysical environments such as gamma-ray bursts, supernova remnants, pulsar wind nebula and coronal mass ejections from the sun. Several spacecraft observations have revealed acceleration of charged particles, mostly electrons, to very high energies with in the shock front. There is now also clear observational evidence that supernova remnant shocks accelerate both protons and electrons. The understanding of the microphysics behind collisionless shocks and their particle acceleration is tightly related with nonlinear basic plasma processes and remains a grand challenge. In this poster, we will present results from recent experiments at the LANL Trident laser facility studying collisionless shocks using intense ps laser (80J, 650 fs - peak intensity of 1020 W/cm2) driven near-critical plasmas using carbon nanotube foam targets. A second short pulse laser driven protons from few microns thick aluminum foil is used to image the laser-driven plasma.

Machine Learning Based Malware Detection

DTIC Science & Technology

2015-05-18

A TRIDENT SCHOLAR PROJECT REPORT NO. 440 Machine Learning Based Malware Detection by Midshipman 1/C Zane A. Markel, USN...COVERED (From - To) 4. TITLE AND SUBTITLE Machine Learning Based Malware Detection 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...suitably be projected into realistic performance. This work explores several aspects of machine learning based malware detection . First, we

76 FR 31632 - Notice of Receipt of Complaint; Solicitation of Comments Relating to the Public Interest

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-01

..., FL; AFC Trident Inc. of Chino, CA; Alibaba.com Hong Kong Ltd. of Hangzhou, China; Anbess Electronics Co. Ltd. of Shenzhen, China; Cellairis Franchise, Inc. of Alpharetta, GA; Cellet Products of Santa Fe Springs, CA; DHgate.com of Beijing, China; Griffin Technology, Inc. of Nashville, TN; Guangzhou Evotech...

77 FR 43593 - Notice of Application for Transfer of License, and Soliciting Comments and Motions To Intervene...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-25

... Application for Transfer of License, and Soliciting Comments and Motions To Intervene; NorQuest Seafoods, Inc.; City of Chignik On June 21, 2012, NorQuest Seafoods, Inc. (transferor) and the City of Chignik...: Transferor: President, NorQuest Seafoods, Inc., c/o Trident Seafoods Corporation, Attention: Mr. Bob Nelson...

Woodland expansion's influence on belowground carbon and nitrogen in the Great Basin U.S.

Treesearch

Benjamin M. Rau; Dale W. Johnson; Robert R. Blank; Robin J. Tausch; Bruce A. Roundy; Richard F. Miller; Todd G. Caldwell; Annmarie Lucchesi

2011-01-01

Vegetation changes associated with climate shifts and anthropogenic disturbance can have major impacts on biogeochemical cycling and soils. Much of the Great Basin, U.S. is currently dominated by sagebrush (Artemisia tridentate (Rydb.) Boivin) ecosystems. Sagebrush ecosystems are increasingly influenced by pinyon (Pinus monophylla Torr. & Frém and Pinus edulis...

Mathematical Modeling: Immune System Dynamics in the Presence of Cancer and Immunodeficiency in vivo

DTIC Science & Technology

2016-05-11

Control 2 Acknowledgments This research was sponsored by the United States Naval Academy’s Trident Scholar Program and the Department of Mathematics... experimental science which relies on qualitative observations; however, in the past decade the need for quantitative analysis has become much more...of Midshipman Research _________________________________________ ___________________________ USNA-1531-2 REPORT

Design, Synthesis and Testing of Novel Antimalarial

DTIC Science & Technology

2006-05-05

U.S.N.A. --- Trident Scholar project report; no. 343 (2006) DESIGN, SYNTHESIS AND TESTING OF NOVEL ANTIMALARIAL COMPOUNDS by Midshipman 1/C...Certification of Adviser Approval Assistant Professor Clare E. Gutteridge Chemistry Department ____________________________________ (signature...Leave blank) 2. REPORT DATE 5 May 2006 3. REPORT TYPE AND DATE COVERED 4. TITLE AND SUBTITLE Design, synthesis and testing of

"Hopping on the Tips of a Trident": Two Graduate Students of Color Reflect on Teaching Critical Content at Predominantly White Institutions

ERIC Educational Resources Information Center

Waring, Chandra D. L.; Bordoloi, Samit Dipon

2012-01-01

In this article, the authors capture the complexity of being a marginalized individual with institutional authority who encourages students to question all levels of power; simultaneously, they are acutely aware of the social implications of students challenging their authority, their intellectual aptitude, and their critical orientation. They…

The discovery of novel tartrate-based TNF-[alpha] converting enzyme (TACE) inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosner, Kristin E.; Guo, Zhuyan; Orth, Peter

2010-09-17

A novel series of TNF-{alpha} convertase (TACE) inhibitors which are non-hydroxamate have been discovered. These compounds are bis-amides of L-tartaric acid (tartrate) and coordinate to the active site zinc in a tridentate manner. They are selective for TACE over other MMP's. We report the first X-ray crystal structure for a tartrate-based TACE inhibitor.

Nose Fairing Modeling and Simulation to Support Trident II D5 Lifecycle Extension

DTIC Science & Technology

2013-09-01

Rupture Flexural Modulus Flexural Yield strength Compressive Yield strength Poissons Ratio Machinabi lily Shear strength Impact Work to...Categories: Ceramic; Glass; Glass Fiber , other Engineeting Material; C<>mposite Rbers Material Notes: Used as a reinforcing agent in fiber glass compos~es...MATWEB AMERICAN SITKA SPRUCE WOOD .......................35 APPENDIX B. MATWEB E–GLASS FIBER , GENERIC ......................................37 APPENDIX

Department of Defense In-House RDT and E Activities

DTIC Science & Technology

1977-10-30

SUPPRFSSI’N CWAMRFR, CAM EVAL & REF CEN, FUEL CELL t RTRY TEST STAS, ELEC PROPULSTON KTM, MPPS POWER TEST CELLS, nFRG TEST HANGAR, MORILE STRESS ANAL...TRIDENT,6S8,ETC) DESGNDEV E FVAL OF U/W TARGET SYSTEMS C MORILE /FIXD U/H TEST RANGES INTRODUCE TO FLEET C IN-SERVICE ENGINEERING OF MK 4S

Tris-(hydroxyamino)triazines: high-affinity chelating tridentate O,N,O-hydroxylamine ligand for the cis-V(V)O2(+) cation.

PubMed

Nikolakis, Vladimiros A; Exarchou, Vassiliki; Jakusch, Tamás; Woolins, J Derek; Slawin, Alexandra M Z; Kiss, Tamás; Kabanos, Themistoklis A

2010-10-14

The treatment of the trichloro-1,3,5-triazine with N-methylhydroxylamine hydrochloride results in the replacement of the three chlorine atoms of the triazine ring with the function -N(OH)CH(3) yielding the symmetrical tris-(hydroxyamino)triazine ligand H(3)trihyat. Reaction of the ligand H(3)trihyat with NaV(V)O(3) in aqueous solution followed by addition of Ph(4)PCl gave the mononuclear vanadium(V) compound Ph(4)P[V(V)O(2)(Htrihyat)] (1). The structure of compound 1 was determined by X-ray crystallography and indicates that this compound has a distorted square-pyramidal arrangement around vanadium. The ligand Htrihyat(2-) is bonded to vanadium atom in a tridentate fashion at the triazine ring nitrogen atom and the two deprotonated hydroxylamido oxygen atoms. The high electron density of the triazine ring nitrogen atoms, which results from the resonative contribution of electrons of exocyclic nitrogen atoms, leads to a very strong V-N bond. The cis-[V(V)O(2)(Htrihyat)](-) species exhibits high hydrolytic stability in aqueous solution over a wide pH range, 2.5-11.5, as was evidenced by potentiometry.

Crystal structure of bis-[tetra-kis-(tetra-hydro-furan-κO)lithium] bis[μ-2,2',2''-methanetriyltris(4,6-di-tert-butylphenolato)-κ4O,O':O',O'']-dimagnesiate.

PubMed

Zhou, Hongyan; Wang, Lei

2017-07-01

The title ion-association metal complex, [Li(C 4 H 8 O) 4 ] 2 [Mg 2 (C 43 H 61 O 3 ) 2 ], has been synthesized from the tridentate phenolic ligand tris-(3,5-di- tert -butyl-2-hy-droxy-phen-yl)methane in tetra-hydro-furan (THF). The aryl-oxo magnesiate complex anion is binuclear with each Mg 2 O 4 complex unit inversion-related and bridged through the two tridentate chelating phenolate O-donors of the ligand. The complex centres have a distorted tetra-hedral stereochemistry [Mg-O range 1.8796 (17)-2.0005 (16) Å] and an Mg⋯Mg separation of 2.9430 (14) Å]. The LiO 4 coodination sphere of the cation comprises four THF O-donor atoms and has a slightly distorted tetra-hedral conformation [Li-O range 1.899 (5)- 1.953 (5) Å]. In the crystal, a number of stabilizing intra-anion C-H⋯O hydrogen-bonding inter-actions are present but no inter-species associations are found.

Tridentate N2S ligand from 2,2′-dithiodibenzaldehyde and N,N-dimethylethylenediamine: Synthesis, structure, and characterization of a Ni(II) complex with relevance to Ni Superoxide Dismutase

PubMed Central

Zimmerman, Joshua R.; Smucker, Bradley W.; Dain, Ryan P.; VanStipdonk, Michael J.

2011-01-01

Nickel Superoxide Dismutase (NiSOD) and the A-cluster of Carbon Monoxide Dehydrogenase/Acetyl Coenzyme A Synthase (CODH/ACS) both feature active sites with Ni coordinated by thiolate and amide donors. It is likely that the particular set of donors is important in tuning the redox potential of the Ni center(s). We report herein an expansion of our efforts involving the use of 2,2′-dithiodibenzaldehyde (DTDB) as a synthon for metal-thiolate complexes to reactions with Ni complexes of N,N-dimethylethylenediamine (dmen). In the presence of coordinating counterions, these reactions result in monomeric square-planar complexes of the tridentate N2S donor ligand derived from the Schiff-base condensation of dmen and DTDB. In the absence of a coordinating counterion, we have isolated a Ni(II) complex with an asymmetric N2S2 donor set involving one amine and one imine N donor in addition to two thiolate donors. This latter complex is discussed with respect to its relevance to the active site of NiSOD. PMID:21666847

SSC 254 Screen-Based Word Processors: Production Tests. The Lanier Word Processor.

ERIC Educational Resources Information Center

Moyer, Ruth A.

Designed for use in Trident Technical College's Secretarial Lab, this series of 12 production tests focuses on the use of the Lanier Word Processor for a variety of tasks. In tests 1 and 2, students are required to type and print out letters. Tests 3 through 8 require students to reformat a text; make corrections on a letter; divide and combine…

Projections of contemporary and future climate niche for Wyoming big sagebrush (Artemisia tridentate subsp. wyomingensis): A guide for restoration

Treesearch

Shannon M. Still; Bryce A. Richardson

2015-01-01

Big sagebrush (Artemisia tridentata) is one of the most widespread and abundant plant species in the intermountain regions of western North America. This species occupies an extremely wide ecological niche ranging from the semi-arid basins to the subalpine. Within this large niche, three widespread subspecies are recognized. Montane ecoregions are occupied by...

Headwaters to estuaries: advances in watershed science and management - Proceedings of the Fifth Interagency Conference on Research in the Watersheds

Treesearch

Christina E. Stringer; Ken W. Krauss; James S. Latimer

2016-01-01

These proceedings contain the abstracts, manuscripts, and posters of presentations given at the Fifth Interagency Conference on Research in the Watersheds—Headwaters to estuaries: advances in watershed science and management, held at the Trident Technical College Conference Center in North Charleston, South Carolina, March 3-5, 2015. The conference was hosted...

Shuttling of nickel oxidation states in N4S2 coordination geometry versus donor strength of tridentate N2S donor ligands.

PubMed

Chatterjee, Sudip K; Roy, Suprakash; Barman, Suman Kumar; Maji, Ram Chandra; Olmstead, Marilyn M; Patra, Apurba K

2012-07-16

Seven bis-Ni(II) complexes of a N(2)S donor set ligand have been synthesized and examined for their ability to stabilize Ni(0), Ni(I), Ni(II) and Ni(III) oxidation states. Compounds 1-5 consist of modifications of the pyridine ring of the tridentate Schiff base ligand, 2-pyridyl-N-(2'-methylthiophenyl)methyleneimine ((X)L1), where X = 6-H, 6-Me, 6-p-ClPh, 6-Br, 5-Br; compound 6 is the reduced amine form (L2); compound 7 is the amide analog (L3). The compounds are perchlorate salts except for 7, which is neutral. Complexes 1 and 3-7 have been structurally characterized. Their coordination geometry is distorted octahedral. In the case of 6, the tridentate ligand coordinates in a facial manner, whereas the remaining complexes display meridional coordination. Due to substitution of the pyridine ring of (X)L1, the Ni-N(py) distances for 1~5 < 3 < 4 increase and UV-vis λ(max) values corresponding to the (3)A(2g)(F)→(3)T(2g)(F) transition show an increasing trend 1~5 < 2 < 3 < 4. Cyclic voltammetry of 1-5 reveals two quasi-reversible reduction waves that correspond to Ni(II)→Ni(I) and Ni(I)→Ni(0) reduction. The E(1/2) for the Ni(II)/Ni(I) couple decreases as 1 > 2 > 3 > 4. Replacement of the central imine N donor in 1 by amine 6 or amide 7 N donors reveals that complex 6 in CH(3)CN exhibits an irreversible reductive response at E(pc) = -1.28 V, E(pa) = +0.25 V vs saturated calomel electrode (SCE). In contrast, complex 7 shows a reversible oxidation wave at E(1/2) = +0.84 V (ΔE(p) = 60 mV) that corresponds to Ni(II)→Ni(III). The electrochemically generated Ni(III) species, [(L3)(2)Ni(III)](+) is stable, showing a new UV-vis band at 470 nm. EPR measurements have also been carried out.

Theoretical study of mixed LiLnX4 (Ln = La, Dy; X = F, Cl, Br, I) rare earth/alkali halide complexes.

PubMed

Groen, C P; Oskam, A; Kovács, A

2000-12-25

The structure, bonding and vibrational properties of the mixed LiLnX4 (Ln = La, Dy; X = F, Cl, Br, I) rare earth/alkali halide complexes were studied using various quantum chemical methods (HF, MP2 and the Becke3-Lee-Yang-Parr exchange-correlation density functional) in conjunction with polarized triple-zeta valence basis sets and quasi-relativistic effective core potentials for the heavy atoms. Our comparative study indicated the superiority of MP2 theory while the HF and B3-LYP methods as well as less sophisticated basis sets failed for the correct energetic relations. In particular, f polarization functions on Li and X proved to be important for the Li...X interaction in the complexes. From the three characteristic structures of such complexes, possessing 1-(C3v), 2-(C2v), or 3-fold coordination (C3v) between the alkali metal and the bridging halide atoms, the bi- and tridentate forms are located considerably lower on the potential energy surface then the monodentate isomer. Therefore only the bi- and tridentate isomers have chemical relevance. The monodentate isomer is only a high-lying local minimum in the case of X = F. For X = Cl, Br, and I this structure is found to be a second-order saddle point. The bidentate structure was found to be the global minimum for the systems with X = F, Cl, and Br. However, the relative stability with respect to the tridentate structure is very small (1-5 kJ/mol) for the heavier halide derivatives and the relative order is reversed in the case of the iodides. The energy difference between the three structures and the dissociation energy decrease in the row F to I. The ionic bonding in the complexes was characterized by natural charges and a topological analysis of the electron density distribution according to Bader's theorem. Variation of the geometrical and bonding characteristics between the lanthanum and dysprosium complexes reflects the effect of "lanthanide contraction". The calculated vibrational data indicate that infrared spectroscopy may be an effective tool for experimental investigation and characterization of LiLnX4 molecules.

Studies of volcanoes of Alaska by satellite radar interferometry

USGS Publications Warehouse

Lu, Z.; Wicks, C.; Dzurisin, D.; Thatcher, W.; Power, J.; ,

2000-01-01

Interferometric synthetic aperture radar (InSAR) has provided a new imaging geodesy technique to measure the deformation of volcanoes at tens-of-meter horizontal resolution with centimeter to subcentimeter vertical precision. The two-dimensional surface deformation data enables the construction of detailed numerical models allowing the study of magmatic and tectonic processes beneath volcanoes. This paper summarizes our recent: InSAR studies over the Alaska-Aleutian volcanoes, which include New Trident, Okmok, Akutan, Augustine, Shishaldin, and Westdahl volcanoes. The first InSAR surface deformation over the Alaska volcanoes was applied to New Trident. Preliminary InSAR study suggested that New Trident volcano experienced several centimeters inflation from 1993 to 1995. Using the InSAR technique, we studied the 1997 eruption of Okmok. We have measured ???1.4 m deflation during the eruption, ???20 cm pre-eruptive inflation during 1992 to 1995, and >10 cm post-eruptive inflation within a year after the eruption, and modeled the deformations using Mogi sources. We imaged the ground surface deformation associated with the 1996 seismic crisis over Akutan volcano. Although seismic swarm did not result in an eruption, we found that the western part of the volcano uplifted ???60 cm while the eastern part of the island subsided. The majority of the complex deformation field at the Akutan volcano was modeled by dike intrusion and Mogi inflation sources. Our InSAR results also indicate that the pyroclastic flows from last the last eruption have been undergoing contraction/subsidence at a rate of about 3 cm per year since 1992. InSAR measured no surface deformation before and during the 1999 eruption of Shishaldin and suggested the eruption may be a type of open system. Finally, we applied satellite radar interferometry to Westdahl volcano which erupted 1991 and has been quiet since. We discovered this volcano had inflated about 15 cm from 1993 to 1998. In summary, satellite radar interferometry can not only be used to study a volcanic eruption, but also to detect aseismic deformation at quiescent volcanoes preceding a seismic swarm; it is a useful technique to study volcanic eruptions as well as to guide scientists to better focus their monitoring efforts.

An electron fixed target experiment to search for a new vector boson A' decaying to e +e -

DOE PAGES

Rouven Essig; Schuster, Philip; Toro, Natalia; ...

2011-02-02

We describe an experiment to search for a new vector boson A' with weak coupling alpha' > 6 x 10 –8 α to electrons (α' = e 2/4π) in the mass range 65 MeV < m A' < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the "dark photon" A' with the photon -- one of the very few ways in which new forces can couple to the Standard Model -- and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiationmore » off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e +e - spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of ~1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and measures the resulting e+e- pairs to search for the A' using the High Resolution Spectrometer and the septum magnet in Hall A. With a ~1 month run, APEX will achieve very good sensitivity because the statistics of e+e- pairs will be ~10,000 times larger in the explored mass range than any previous search for the A' boson. These statistics and the excellent mass resolution of the spectrometers allow sensitivity to α'/α one to three orders of magnitude below current limits, in a region of parameter space of great theoretical and phenomenological interest. Similar experiments could also be performed at other facilities, such as the Mainz Microtron.« less

TRIDENT II (D-5) Strategic Weapon System Guide for Potential Subcontractors.

DTIC Science & Technology

1982-01-01

pattern. Usually high technology item subcontracts are the first selected, This is followed by crit- ical, special long-lead time, common, and...performance. These disciplines provide the program with a definitive approach to maintaining high standards of reliability and readiness for weapon system...missile itself will be increased in length and diameter.. The range of the missile will be enhanced, and it will carry an increased payload. Energy

76 FR 15302 - Notice of Public Hearing for the Draft Environmental Impact Statement for the TRIDENT Support...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-21

.... April 21, 2011, at the Seattle Central Library, 1000 Fourth Avenue, Seattle, WA 98104. All meetings will start with an open house session from 6 p.m. to 7:30 p.m. followed by a presentation and public comment period from 7:30 p.m. to 9 p.m. The open house sessions will allow individuals the opportunity to review...

A Decreasing Failure Rate, Mixed Exponential Model Applied to Reliability.

DTIC Science & Technology

1981-06-01

Trident missile systems have been observed. The mixed exponential distribu- tion has been shown to fit the life data for the electronic equipment on...these systems . This paper discusses some of the estimation problems which occur with the decreasing failure rate mixed exponential distribution when...assumption of constant or increasing failure rate seemed to be incorrect. 2. However, the design of this electronic equipment indicated that

Monitoring Maritime Conditions with Unmanned Systems During Trident Warrior 2013

DTIC Science & Technology

2014-01-01

Host- ing Autonomous Remote Craft or SHARC model ) that emit sounds and listen for reflected changes in response to ocean currents. Experiments tested...San Diego Scripps Institution of Oceanography were also deployed; these provided Acoustic Doppler Current Profiler (ADCP) 3D measurements of the...ocean currents as well as measurements of the surface meteorology . Figure 5(b) shows a schematic representa- tion of one wave glider and two ocean

Computer-Based Instruction for TRIDENT FBM Training

DTIC Science & Technology

1976-06-01

remote voice feedback to an operator. In this case it is possible to display text which represents the voice messages required during sequential ...provides two main services: (a) the preparation of missiles for sequential launching with self-guidance after launch, and (b) the coordination of...monitor- ing the status of the guidance system in each missile. FCS SWS coordina- tion consists of monitoring systems involved in sequential functions at

Innovative trident fixation technique for allograft knee arthrodesis for high-grade osteosarcoma around the knee.

PubMed

Su, Alvin W; Chen, Wei-Ming; Chen, Cheng-Fong; Chen, Tain-Hsiung

2009-11-01

Reconstruction for osteosarcoma around the knee after wide resection faces the challenge of great bone defect and future limb length discrepancy in the skeletally immature patients. Modern prosthetic reconstruction may provide good results, but the longevity may be of concern and may not be affordable in certain communities. Allograft knee arthrodesis still has its role in light of bone stock preservation and cost-effectiveness. We developed the innovative trident fixation technique utilizing three Steinmann pins to minimize limb length inequality without jeopardizing knee fusion stability. Twelve patients were enrolled. The mean age was 11.5 (10-13) years. Two had high-grade osteosarcoma in proximal tibia and others in distal femur. Two patients died of oncological disease. The median follow-up of the disease-free 10 patients was 47 (41-60) months. All allograft-host bone junctions healed uneventfully without major complications except one allograft fracture. The average limb length discrepancy was 1.45 (1.0-2.1) cm at latest follow-up. This straightforward technique was successful in knee arthrodesis with minimized limb length inequality. Accordingly, in light of bone stock preservation and longevity for the young children, it may be a surgical alternative for malignant bone tumors around the knee.

A new tridentate Schiff base Cu(II) complex: synthesis, experimental and theoretical studies on its crystal structure, FT-IR and UV-Visible spectra.

PubMed

Saheb, Vahid; Sheikhshoaie, Iran; Setoodeh, Nasim; Rudbari, Hadi Amiri; Bruno, Giuseppe

2013-06-01

A new Cu(II) complex [Cu(L)(NCS)] has been synthesized, using 1-(N-salicylideneimino)-2-(N,N-methyl)-aminoethane as tridentate ONN donor Schiff base ligand (HL). The dark green crystals of the compound are used for single-crystal X-ray analysis and measuring Fourier Transform Infrared (FT-IR) and UV-Visible spectra. Electronic structure calculations at the B3LYP and MP2 levels of theory are performed to optimize the molecular geometry and to calculate the UV-Visible and FT-IR spectra of the compound. Vibrational assignments and analysis of the fundamental modes of the compound are performed. Time-dependent density functional theory (TD-DFT) method is used to calculate the electronic transitions of the complex. A scaling factor of 1.015 is obtained for vibrational frequencies computed at the B3LYP level using basis sets 6-311G(d,p). It is found that solvent has a profound effect on the electronic absorption spectrum. The UV-Visible spectrum of the complex recorded in DMSO and DMF solution can be correctly predicted by a model in which DMSO and DMF molecules are coordinated to the central Cu atom via their oxygen atoms. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis and characterization of heteroleptic titanium MOCVD precursors for TiO2 thin films.

PubMed

Kim, Euk Hyun; Lim, Min Hyuk; Lah, Myoung Soo; Koo, Sang Man

2018-02-13

Heteroleptic titanium alkoxides with three different ligands, i.e., [Ti(O i Pr)(X)(Y)] (X = tridentate, Y = bidentate ligands), were synthesized to find efficient metal organic chemical vapor deposition (MOCVD) precursors for TiO 2 thin films. Acetylacetone (acacH) or 2,2,6,6-tetramethyl-3,5-heptanedione (thdH) was employed as a bidentate ligand, while N-methyldiethanolamine (MDEA) was employed as a tridentate ligand. It was expected that the oxygen and moisture susceptibility of titanium alkoxides, as well as their tendency to form oligomers, would be greatly reduced by placing multidentate and bulky ligands around the center Ti atom. The synthesized heteroleptic titanium alkoxides were characterized both physicochemically and crystallographically, and their thermal behaviors were also investigated. [Ti(O i Pr)(MDEA)(thd)] was found to be monomeric and stable against moisture; it also showed good volatility in the temperature window between volatilization and decomposition. This material was used as a single-source precursor during MOCVD to generate TiO 2 thin films on silicon wafers. The high thermal stability of [Ti(O i Pr)(MDEA)(thd)] enabled the fabrication of TiO 2 films over a wide temperature range, with steady growth rates between 500 and 800 °C.

First-row transition metal complexes of ENENES ligands: the ability of the thioether donor to impact the coordination chemistry

DOE PAGES

Dub, Pavel A.; Scott, Brian L.; Gordon, John C.

2015-12-21

We report the reactions of two variants of ENENES ligands, E(CH 2) 2NH(CH) 2SR, where E = 4-morpholinyl, R = Ph (a), Bn (b) with MCl 2 (M = Mn, Fe, Co, Ni and Cu) in coordinating solvents (MeCN, EtOH) affords isolable complexes, whose magnetic susceptibility measurements suggest paramagnetism and a high-spin formulation. X-Ray diffraction studies of available crystals show that the ligand coordinates to the metal in either a bidentate κ 2[N,N'] or tridentate κ 3[N,N',S] fashion, depending on the nature of ligand and/or identity of the metal atom. In the case of a less basic SPh moiety, amore » bidentate coordination mode was identified for harder metals (Mn, Fe), whereas a tridentate coordination mode was identified in the case of a more basic SBn moiety with softer metals (Ni, Cu). In the intermediate case of Co, ligands a and b coordinate via κ 2[N,N'] and κ 3[N,N',S] coordination modes, which can be conveniently predicted by DFT calculations. Finally, for the softest metal (Cu), ligand a coordinates in a κ 3[N,N',S] fashion.« less

An olfactory shift is associated with male perfume differentiation and species divergence in orchid bees.

PubMed

Eltz, Thomas; Zimmermann, Yvonne; Pfeiffer, Carolin; Pech, Jorge Ramirez; Twele, Robert; Francke, Wittko; Quezada-Euan, J Javier G; Lunau, Klaus

2008-12-09

Saltational changes may underlie the diversification of pheromone communication systems in insects, which are normally under stabilizing selection favoring high specificity in signals and signal perception. In orchid bees (Euglossini), the production of male signals depends on the sense of smell: males collect complex blends of volatiles (perfumes) from their environment, which are later emitted as pheromone analogs at mating sites. We analyzed the behavioral and antennal response to perfume components in two male morphotypes of Euglossa cf. viridissima from Mexico, which differ in the number of mandibular teeth. Tridentate males collected 2-hydroxy-6-nona-1,3-dienyl-benzaldehyde (HNDB) as the dominant component of their perfume. In bidentate males, blends were broadly similar but lacked HNDB. Population genetic analysis revealed that tri- and bidentate males belong to two reproductively isolated lineages. Electroantennogram tests (EAG and GC-EAD) showed substantially lower antennal responses to HNDB in bidentate versus tridentate males, revealing for the first time a mechanism by which closely related species acquire different chemical compounds from their habitat. The component-specific differences in perfume perception and collection in males of two sibling species are in agreement with a saltational, olfaction-driven mode of signal perfume evolution. However, the response of females to the diverged signals remains unknown.

Development of a novel tridentate ligand for colorimetric detection of Mn2+ based on AgNPs.

PubMed

Wei, Jianyu; Chen, Jinfan; Yue, Guozong; Hu, Liangsheng; Zhao, Danqing; Zhu, Jing; Yang, Luming; Huang, Deshun; Zhao, Pengxiang

2018-05-09

A novel tridentate ligand nitrilotris(methylene)tris(1,2,3-triazole)triacetate (NTTTA) has been synthesized by click reaction and followed with ester hydrolysis reaction. The silver nanoparticles (AgNPs) were then modified and stabilized by this ligand, and subsequently been employed for the highly selective and sensitive colorimetric detection of Mn 2+ in aqueous solution. The presence of Mn 2+ can cause the aggregation of AgNPs, which leads to the color change of the dispersion from yellow to brown, as well as the decrease and red-shift of the surface plasmon resonance absorption. The detection limit of Mn 2+ was as approximately 0.5 μM by the naked eyes. UV-vis spectroscopy analysis showed a good linear relationship between the logarithm of the ratios (A 550 /A 395 ) and the concentration of Mn 2+ over the range of 0.05 μM-10 μM, and the LOD was calculated to be 12.6 nM (S/N = 3). The present assay showed good simplicity without the need of adjusting the pH value. The feasibility of this technique was evaluated for successful detection of Mn 2+ in tap water and lake water samples, with good recoveries. Copyright © 2018 Elsevier B.V. All rights reserved.

Iridium Catalysts with f-Amphox Ligands: Asymmetric Hydrogenation of Simple Ketones.

PubMed

Wu, Weilong; Liu, Shaodong; Duan, Meng; Tan, Xuefeng; Chen, Caiyou; Xie, Yun; Lan, Yu; Dong, Xiu-Qin; Zhang, Xumu

2016-06-17

A series of modular and rich electronic tridentate ferrocene aminophosphoxazoline ligands (f-amphox) have been successfully developed and used in iridium-catalytic asymmetric hydrogenation of simple ketones to afford corresponding enantiomerically enriched alcohols under mild conditions with superb activities and excellent enantioselectivities (up to 1 000 000 TON, almost all products up to >99% ee, full conversion). The resulting chiral alcohols and their derivatives are important intermediates in pharmaceuticals.

Minimal Deterrence Research

DTIC Science & Technology

2001-07-17

ed nuclear conflict. The former is marked by an objective of thorough and complete destruction of an opponent’s society, industry, and wealth...weapon state. 74 B. The 1994 Defense White Paper The end of the Cold War marked the beginning of a significant turning point in French military...Trident SLBM. A. Massive Retaliation The United Kingdom’s contribution to the US Manhattan Project and its own nuclear test in 1952 marked the country’s

Raised levels of metal ions in the blood in patients who have undergone uncemented metal-on-polyethylene Trident-Accolade total hip replacement.

PubMed

Craig, P; Bancroft, G; Burton, A; Collier, S; Shaylor, P; Sinha, A

2014-01-01

The issues surrounding raised levels of metal ions in the blood following large head metal-on-metal total hip replacement (THR), such as cobalt and chromium, have been well documented. Despite the national popularity of uncemented metal-on-polyethylene (MoP) THR using a large-diameter femoral head, few papers have reported the levels of metal ions in the blood following this combination. Following an isolated failure of a 44 mm Trident-Accolade uncemented THR associated with severe wear between the femoral head and the trunnion in the presence of markedly elevated levels of cobalt ions in the blood, we investigated the relationship between modular femoral head diameter and the levels of cobalt and chromium ions in the blood following this THR. A total of 69 patients received an uncemented Trident-Accolade MoP THR in 2009. Of these, 43 patients (23 men and 20 women, mean age 67.0 years) were recruited and had levels of cobalt and chromium ions in the blood measured between May and June 2012. The patients were then divided into three groups according to the diameter of the femoral head used: 12 patients in the 28 mm group (controls), 18 patients in the 36 mm group and 13 patients in the 40 mm group. A total of four patients had identical bilateral prostheses in situ at phlebotomy: one each in the 28 mm and 36 mm groups and two in the 40 mm group. There was a significant increase in the mean levels of cobalt ions in the blood in those with a 36 mm diameter femoral head compared with those with a 28 mm diameter head (p = 0.013). The levels of cobalt ions in the blood were raised in those with a 40 mm diameter head but there was no statistically significant difference between this group and the control group (p = 0.152). The levels of chromium ions in the blood were normal in all patients. The clinical significance of this finding is unclear, but we have stopped using femoral heads with a diameter of ≤ 36 mm, and await further larger studies to clarify whether, for instance, this issue particularly affects this combination of components.

Magma storage and mixing conditions for the 1953-1974 eruption of Southwest Trident volcano, Katmai National Park, Alaska

USGS Publications Warehouse

Coombs, Michelle L.; Eichelberger, John C.; Rutherford, Malcom J.

2000-01-01

Between 1953 and 1974, approximately 0.5 km3 of andesite and dacite erupted from a new vent on the southwest flank of Trident volcano in Katmai National Park, Alaska, forming an edifice now known as Southwest (or New) Trident. Field, analytical, and experimental evidence shows that the eruption commenced soon after mixing of dacite and andesite magmas at shallow crustal levels. Four lava flows (58.3–65.5 wt% SiO2) are the dominant products of the eruption; these contain discrete andesitic enclaves (55.8–58.9 wt% SiO2) as well as micro- and macro-scale compositional banding. Tephra from the eruption spans the same compositional range as lava flows; however, andesite scoria (56–58.1 wt% SiO2) is more abundant relative to dacite tephra, and is the explosively erupted counterpart to andesite enclaves. Fe–Ti oxide pairs from andesite scoria show a limited temperature range, clustered around 1000 °C. Temperatures from grains found in dacite lavas possess a wider range; however, cores from large (>100 μm) magnetite and coexisting ilmenite give temperatures of ∼890 °C, taken to represent a pre-mixing temperature for the dacite. Water contents from dacite phenocryst melt inclusions and phase equilibria experiments on the andesite imply that the two magmas last resided at a water pressure of 90 MPa, and contained ∼3.5 wt% H2O, equivalent to 3 km depth if saturated. Unzoned pyroxene and sodic plagioclase in the dacite suggest that it likely underwent significant crystallization at this depth; highly resorbed anorthitic plagioclase from the andesite suggests that it originated at greater depths and underwent relatively rapid ascent until it reached 3 km, mixed with dacite, and erupted. Diffusion profiles in phenocrysts suggest that mixing preceded eruption of earliest lava by approximately one month. The lack of a compositional gap in the erupted rock suite indicates that thorough mixing of the andesite and dacite occurred quickly, via disaggregation of enclaves, phenocryst transfer from one magma to another, and direct mixing of compositionally distinct melt phases.

catena-Poly[[[4,6-bis-(2-pyrid-yl)-1,3,5-triazin-2-olato]copper(II)]-μ-chlorido].

PubMed

Cao, Man-Li

2011-06-01

The title compound, [Cu(C(13)H(8)N(5)O)Cl](n), has a chain structure parallel to [100] with Cu(2+) cations in a trigonal-bipyramidal coordination environment. The ligand adopts a tridentate tripyridyl coordination mode and a chloride ion acts as a bridge. The chains are linked via weak C-H⋯O and C-H⋯Cl hydrogen bonds into a three-dimensional supra-molecular network.

Review of Literature on Waste Solidification/Stabilization with Emphasis on Metal-Bearing Wastes

DTIC Science & Technology

1989-08-01

applicability to treating a wide variety of waste types, and the ease with 4 which they are implemented in the field (Wiles and Apel , undated). Asphaltic...Wiles, C.C., 1987. A Review of Solidification/Stabilization Technology. Journal of Hazardous Materials, 14:5-21. Wiles, C.C., and Apel , M.L., undated...Personal correspondence and attachments from William McLaughlin, 1-714-693-1818, 1988. Trident Engineering Associates, 48 Maryland Ave., Annapolis, Maryland

AXBT Observations during Trident Warrior 2013

DTIC Science & Technology

2013-09-30

Standard P ::~~ Standard ::= ISOP ··-10.3818) U~E:AST ::=~ HYCOM ~~~~ GDEM 0 .5 (0.4289) ....... , (me an S tD E nor) (1.836) (Ala) U CUP Standard...P f:~~l standard F.~n [1.617] (1 .311 ) I SOP U SEAST ::~~~ HVCOM 1:1’:~1 GDEM (1..663) I I A] 1 .5 AXBT 38.5 38 37.5 s: 37 ~ 3G.5 ! 36

Development of a Generic Hull Stiffener Modelling Capability for Trident Modeller

DTIC Science & Technology

2013-09-01

Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 This page intentionally left blank. i Abstract …….. This...if a RefCurve referenced an IGES file containing more than one curve, it was assumed that the curves already formed an ordered, connected path; the

Perfluorinated Ligands in Organometallic Chemistry

DTIC Science & Technology

1989-12-12

C49t00ooVER ,or C M’ AD"OV’~mDecember 12) 199IFinal 1/1/86 to 8/31/89C smuS. FUNOING NUMgIERS cJ Perfluorinated Ligands in Organometallic Chemistry 612...compounds, stabilized by tridentate perfluorinated ligands. Dinuclear rhodium complexes of OFCOT undergo a selective C-F bond activation reaction...hexafluorocyclooctatrieneyne ligand. Stereospecific cleavage of a fluorinated C-C bond,#-bond in perfluorocyclopropene by platinum and iridium complexes has been achieved

DOD Supply Chain: Suspect Counterfeit Electronic Parts Can Be Found on Internet Purchasing Platforms

DTIC Science & Technology

2012-02-01

Parts Marine Corps’s V-22 Osprey aircraft, and the Navy’s SSN-688 Los Angeles Class nuclear-powered attack submarine . If authentic, these parts...authentication analyses. Visual inspection was performed on all evidence samples from both purchases. Different color epoxy seals were noted within both...including the ballistic missile early warning system, the Air Force’s Peacekeeper missile and B-1B aircraft, the Navy’s Trident submarine and Arleigh

Eruptive history of Mount Katmai, Alaska

USGS Publications Warehouse

Hildreth, Edward; Fierstein, Judith

2012-01-01

Compositionally, products of Mount Katmai represent an ordinary medium-K arc array, both tholeiitic and calcalkaline, that extends from 51.6% to 72.3% SiO2. Values of 87Sr/86Sr range from 0.70335 to 0.70372, correlating loosely with fractionation indices. The 5–6 km3 of continuously zoned andesite-dacite magma (58%–68% SiO2) that erupted at Novarupta in 1912 was withdrawn from beneath Mount Katmai and bears close compositional affinity with products of that edifice, not with pre-1912 products of the adjacent Trident cluster. Evidence is presented that the 7–8 km3 of high-silica rhyolite (77% SiO2) released in 1912 is unlikely to have been stored under Novarupta or Trident. Pre-eruptive contiguity with the andesite-dacite reservoir is suggested by (1) eruption of ∼3 km3 of rhyolite magma first, followed by mutual mingling in fluctuating proportions; (2) thermal and redox continuity of the whole zoned sequence despite the wide compositional gap; (3) Nd, Sr, O isotopic, and rare earth element (REE) affinities of the whole array; (4) compositional continuity of the nearly aphyric rhyolite with the glass (melt) phase of the phenocryst-rich dacite; and (5) phase-equilibrium experiments that indicate similar shallow pre-eruptive storage depths (3–6 km) for rhyolite, dacite, and andesite.

Interaction of NaOH solutions with silica surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rimsza, Jessica M.; Jones, Reese E.; Criscenti, Louise J.

Sodium adsorption on silica surfaces depends on the solution counter-ion. Here, we use NaOH solutions to investigate basic environments. Sodium adsorption on hydroxylated silica surfaces from NaOH solutions were investigated through molecular dynamics with a dissociative force field, allowing for the development of secondary molecular species. Furthermore, across the NaOH concentrations (0.01 M – 1.0 M), ~50% of the Na + ions were concentrated in the surface region, developing silica surface charges between –0.01 C/m 2 (0.01 M NaOH) and –0.76 C/m 2 (1.0 M NaOH) due to surface site deprotonation. Five inner-sphere adsorption complexes were identified, including monodentate, bidentate,more » and tridentate configurations and two additional structures, with Na + ions coordinated by bridging oxygen and hydroxyl groups or water molecules. Coordination of Na + ions by bridging oxygen atoms indicates partial or complete incorporation of Na + ions into the silica surface. Residence time analysis identified that Na + ions coordinated by bridging oxygen atoms stayed adsorbed onto the surface four times longer than the mono/bi/tridentate species, indicating formation of relatively stable and persistent Na + ion adsorption structures. Such inner-sphere complexes form only at NaOH concentrations of > 0.5 M. Na + adsorption and lifetimes have implications for the stability of silica surfaces.« less

Interaction of NaOH solutions with silica surfaces

DOE PAGES

Rimsza, Jessica M.; Jones, Reese E.; Criscenti, Louise J.

2018-01-16

Sodium adsorption on silica surfaces depends on the solution counter-ion. Here, we use NaOH solutions to investigate basic environments. Sodium adsorption on hydroxylated silica surfaces from NaOH solutions were investigated through molecular dynamics with a dissociative force field, allowing for the development of secondary molecular species. Furthermore, across the NaOH concentrations (0.01 M – 1.0 M), ~50% of the Na + ions were concentrated in the surface region, developing silica surface charges between –0.01 C/m 2 (0.01 M NaOH) and –0.76 C/m 2 (1.0 M NaOH) due to surface site deprotonation. Five inner-sphere adsorption complexes were identified, including monodentate, bidentate,more » and tridentate configurations and two additional structures, with Na + ions coordinated by bridging oxygen and hydroxyl groups or water molecules. Coordination of Na + ions by bridging oxygen atoms indicates partial or complete incorporation of Na + ions into the silica surface. Residence time analysis identified that Na + ions coordinated by bridging oxygen atoms stayed adsorbed onto the surface four times longer than the mono/bi/tridentate species, indicating formation of relatively stable and persistent Na + ion adsorption structures. Such inner-sphere complexes form only at NaOH concentrations of > 0.5 M. Na + adsorption and lifetimes have implications for the stability of silica surfaces.« less

Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff base ligands: Synthesis, characterization and biocidal activities

NASA Astrophysics Data System (ADS)

Shabbir, Muhammad; Akhter, Zareen; Ashraf, Ahmad Raza; Ismail, Hammad; Habib, Anum; Mirza, Bushra

2017-12-01

Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff bases have been prepared and characterized by elemental analysis as well as by spectroscopic techniques (FTIR & NMR). The synthesized compounds were assessed to check their potential biocidal activity by using different biological assays (brine shrimp cytotoxicity, antimicrobial, antioxidant, antitumor and drug-DNA interaction). Results of brine shrimp cytotoxicity assay showed that ligand molecules are more bioactive than metal complexes with LD50 as low as 12.4 μg/mL. The prominent antitumor activity was shown by nickel complexes while the palladium complexes exhibited moderate activity. The synthesized compounds have shown high propensity for DNA binding either through intercalation or groove binding which represents the mechanism of antitumor effect of these compounds. Additionally, ligand molecules and nickel metal complexes showed significant antioxidant activity with IC50 values as low as 3.1 μg/mL and 18.9 μg/mL respectively while palladium complexes exhibited moderate activity. Moreover, in antimicrobial assays H2L1, Ni(L1)PPh3 and H2L3 showed dual inhibition against bacterial and fungal strains while for the rest of the compounds varying degree of activity was recorded against different strains. Overall comparison of results suggests that the synthesized compounds can be promising candidate for drug formulation and development.

Recent High-Intensity Experiments at the Trident Laser

NASA Astrophysics Data System (ADS)

Cobble, James; Palaniyappan, Sasikumar; Gautier, Cort; Kim, Yongho; Huang, Chengkun

2014-10-01

With near-diffraction-limited irradiance of 2 × 1020 W/cm2 on target and prelase contrast better than 10-8, we have accessed the regime of relativistic transparency (RT) at the Trident Laser. The goal was to assess electron debris emitted from the target rear surface with phase-contrast imaging (PCI) and current density measurements (hence, the total electron current). Companion diagnostics show whether the experiments are in the target-normal-sheath-acceleration mode or in the RT regime. The superb laser contrast allows us to shoot targets as thin as 50 nm. PCI at 527 nm is temporally resolved to 600 fs. It has shown the evolution of electron behavior over tens of ps, including thermal electrons accompanying the ion jet, accelerated to many tens of MeV earlier in time. Faraday-cup measurements indicate the transfer of many microC of charge during the laser drive. As a ride-along experiment using a gas Cherenkov detector (GCD), we have detected gamma rays of energy >5 MeV. This radiation has a prompt component and a lesser source, driven by accelerated ions, that is time resolved by the GCD. The ion time of flight is compared to Thomson parabola data. Electron energy spectra are also collected. This work is supported by US DOE/NNSA, performed at LANL, operated by LANS LLC under Contract DE-AC52-06NA25396.

Relativistic Transparency Experiments at the Trident Laser

NASA Astrophysics Data System (ADS)

Cobble, J. A.; Palaniyappan, S.; Gautier, D. C.; Kim, Y. H.; Clark, D. D.; Johnson, R. P.; Shimada, T.; Fernandez, J. C.; Herrmann, H. W.

2013-10-01

With near-diffraction-limited irradiance of 3 × 1020 W/cm2 on target and prelase contrast better than 10-9, we have accessed the regime of relativistic transparency (RT) at the Trident Laser. The goal was to assess electron debris emitted from the target rear surface with phase-contrast imaging (PCI) and current density measurements (hence, the total electron current). Companion diagnostics show whether the experiments are in the target-normal-sheath-acceleration mode or in the RT regime. The superb laser contrast allows us to shoot targets as thin as 50 nm. PCI at 527 nm is temporally resolved to 600 fs. It has shown the evolution of electron behavior over tens of ps, including thermal electrons accompanying the ion jet, accelerated to many tens of MeV earlier in time. Faraday-cup measurements indicate the transfer of many uC of charge during the laser drive. As a ride-along experiment using a gas Cherenkov detector (GCD), we have detected gamma rays of energy >5 MeV. This radiation has a prompt component and a lesser source, driven by accelerated ions, that is time resolved by the GCD. The ion time of flight is compared to Thomson parabola data. Electron energy spectra are also collected. This work has been performed under the auspices of the US DOE contract number DE-AC52-06NA25396.

Complexes of cis-dioxomolybdenum(VI) and oxovanadium(IV) with a tridentate ONS donor ligand: Synthesis, spectroscopic properties, X-ray crystal structure and catalytic activity

NASA Astrophysics Data System (ADS)

Fayed, Ahmed M.; Elsayed, Shadia A.; El-Hendawy, Ahmed M.; Mostafa, Mohamed R.

2014-08-01

New cis-dioxomolybdenum(VI) and oxovanadium(IV) complexes of the Schiff base, derived from S-methyl dithiocarbazate and 2,3-dihydroxybenzaldehyde (H2dhsm), have been synthesized. The complexes of the type cis-[MoO2(dhsm)] (1a), cis-[MoO2(dhsm)(D)] (1b-1d) [D = neutral monodentate ligand; EtOH, pyridine (py) or imidazole (imz)], [VO(dhsm)(Nsbnd N)] (2a, 2b) [Nsbnd N = 2,2‧-bipyridine (bipy) or 1,10-phenanthroline (phen)] and [VO(dhsm)] (2c) have been isolated, characterized by 1H NMR, IR, UV-Vis and EPR spectral studies and investigated by cyclic voltammetry. The X-ray crystal structure of cis-[MoO2(dhsm)(EtOH)] (1b) has been determined and shows that the complex has a distorted octahedral geometry in which the H2dhsm behaves as a dianionic ONS tridentate ligand coordinating via phenoxide oxygen, hydrazinic nitrogen and thiolate sulfur. The oxomolybdenum(IV) complex [MoO(dhsm)] (1e) has obtained from dioxomolybdenum(VI) complex (1b) by oxo abstraction with PPh3. The reactivity of the complexes toward catalytic oxidation of alcohols in the presence of H2O2 and t-BuOOH as co-oxidants under solvent free conditions is reported.

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry.

PubMed

Bilton, Holly A; Ahmad, Zainab; Janzen, Nancy; Czorny, Shannon; Valliant, John F

2017-02-04

Pre-targeting combined with bioorthogonal chemistry is emerging as an effective way to create new radiopharmaceuticals. Of the methods available, the inverse electron demand Diels-Alder (IEDDA) cycloaddition between a radiolabeled tetrazines and trans-cyclooctene (TCO) linked to a biomolecule has proven to be a highly effective bioorthogonal approach to imaging specific biological targets. Despite the fact that technetium-99m remains the most widely used isotope in diagnostic nuclear medicine, there is a scarcity of methods for preparing 99m Tc-labeled tetrazines. Herein we report the preparation of a family of tridentate-chelate-tetrazine derivatives and their Tc(I) complexes. These hitherto unknown compounds were radiolabeled with 99m Tc using a microwave-assisted method in 31% to 83% radiochemical yield. The products are stable in saline and PBS and react rapidly with TCO derivatives in vitro. Their in vivo pre-targeting abilities were demonstrated using a TCO-bisphosphonate (TCO-BP) derivative that localizes to regions of active bone metabolism or injury. In murine studies, the 99m Tc-tetrazines showed high activity concentrations in knees and shoulder joints, which was not observed when experiments were performed in the absence of TCO-BP. The overall uptake in non-target organs and pharmacokinetics varied greatly depending on the nature of the linker and polarity of the chelate.

Reactivity of tris(acetylacetonato) iron(III) with tridentate [ONO] donor Schiff base as an access to newer mixed-ligand iron(III) complexes

NASA Astrophysics Data System (ADS)

Bhattacharjee, Chira R.; Goswami, Pankaj; Pramanik, Harun A. R.; Paul, Pradip C.; Mondal, Paritosh

2011-05-01

Two new mixed-ligand iron(III) complexes, [Fe(L n)(acac)(C 2H 5OH)] incorporating coordinated ethanol from the reaction solvent were accessed from the reaction of [Fe(acac) 3] with [ONO] donor dibasic tridentate unsymmetrical Schiff base ligands derived from condensation of 2-hydroxy-1-napthaldehyde with 2-aminophenol (H 2L 1) or 2-aminobenzoic acid (H 2L 2). The thermal study (TGA-DTA) provided evidence for weakly bound ethanol which is readily substituted by neutral N-donor molecule imidazole, benzimidazole or pyridine to produce an array of newer complexes, [Fe(L n)(acac)X] ( n = 1, 2; X = Im, Bim, Py). The compounds were characterized by elemental analyses, FT-IR, UV-vis, solution electrical conductivity, FAB mass, 1H and 13C NMR spectroscopy. Room temperature magnetic susceptibility measurements ( μeff ˜ 5.8 B.M.) are consistent with spin-free octahedral iron(III) complexes. Cyclic voltammetry of ethanol complexes revealed a quasi-reversible one electron redox response (Δ Ep > 100 mV) for the Fe(III)/Fe(II) couple. Low half wave redox potential ( E1/2) values suggested easy redox susceptibility. The ground state geometries of the ethanol and imidazole complexes have been ascertained to be distorted octahedral by density functional theory using DMol3 program at BLYP/DNP level.

Navy Ohio Replacement (SSBN[X]) Ballistic Missile Submarine Program: Background and Issues for Congress

DTIC Science & Technology

2015-12-17

strategic nuclear arms reduction treaty that included 14 Ohio-class SSBNs, all armed with D- 5s . This recommendation prompted interest in the idea of...a program to extend the service life of the Trident II D-5 SLBM into the 2040s, and to have its next-generation SSBNs carry D- 5s . Following this...Navy states that 10 operational SSBNs—meaning boats not encumbered by lengthy maintenance actions—are needed to meet strategic nuclear deterrence

Developments in Science and Technology

DTIC Science & Technology

1979-01-01

Testing of the APL OTEC Heat Exchanger as an Evaporator 74 P. P. Pandolfini, J. L. Keirsey, antd J. A. Funk Geothermal Energy Market Study on the Atlantic...Wozniak I. J. J. Wozniak, Follow- on Study of the Towed Underwater Launch Platforn (TULP) Concept for Trident It Testing, APL/JIIU PM. 8342, Oct 1978... studies . MAGSAT was shipped to Vandenberg AB, REFERENCES California, on 5 October 1979. Field operations coim- 1 51,(,i1 1srujtl.’ tiim. APt Jil L Sl) 114b

Trident Biological Surveys: SUBASE Bangor (July 1977 and June 1978) and Indian Island Annex (January, May 1974 and June 1978). Supplement 2.

DTIC Science & Technology

1979-12-01

or critical marine habitats affected by construction activities. Adverse impact has been limited to the biota physically disrupted by the mechanical ...Adverse impact has been limited to the biota physically disrupted by the mechanical process of pier construction. Commercial clam densities, standing crop...such as those at SUBASE Bangor. Samples are often expensive and time consuming to obtain: however, the reliability of one’s results depends heavily upon

Neutron Radiation Effects in Fiber Optics.

DTIC Science & Technology

1980-06-05

due to naturevs effects , the photophone as a device was doomed. However the principles of voice transmission by modulated ]iqht beams were not. From...AD-A091 661 NAVAL ACADEMY ANNAPOLIS NO F/S 20/6 NEUTRON RADIATION EFFECTS IN FIBER OPTICS.(U) N.N 80 M J MARSHFIELD NCLASSIFIED USNA-TSPR-107 MLE...34’I//E/////EE I ffffffffffffff /l-"lll/"."lmIii//2 //0 A TRIDENT SCHOLAR * PROJECT REPORT NO. 1im "NEUTRON RADIATION EFFECTS IN FIBE OPTICS UNITED

Next Generation 9-1-1: Policy Implications of Incident Related Imagery on the Public Safety Answering Point

DTIC Science & Technology

2017-03-01

Enhanced 9-1-1 EMD eye movement desensitization and reprocessing EMS emergency medical service ESInet Emergency Service IP Network ETNS...Trident), football at Peter B’s, Texas Hold ‘ Em mid-IR, countless cups of Starbucks coffee, and of course, Manny’s Cuban brew. Each of you made this...something to consider. The military has done a good job of recognizing the effects of this [PTSD] trauma. Sadly, the Fire Service, EMS and Law

The Budget of the United States Government. Department of Defense Extract for Fiscal Years 1990 and 1991

DTIC Science & Technology

1988-01-01

i.e., programs gen - erally subject to control by annual appropriations) were $6.3 billion above the Administration’s original request for policy reasons...unobligated balance avail- Amounts for proposed new legislation are shown gen - able, end of year. That balance is carried forward and erally in separate...Program and Financing (in thousands of dollars) Trident strategic missile and submarine continues. Gen - lan 97-0819-0-1-051 199 actual 1909 e. 19eral

The Use of Thermal Spraying to Enhance the Bonding Characteristics of a Urethane Coated Propeller

DTIC Science & Technology

1999-05-03

NAME(S) AND ADDRESS( ES ) 8. PERFORMING ORGANIZATION REPORT NUMBER U.S. Naval Academy USNA Trident Scholar project report Annapolis, MD no. 265 (1999...9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS( ES ) 10. SPONSORING/MONITORING AGENCY REPORT NUMBER 11. SUPPLEMENTARY NOTES Accepted by the U.S...TEST: A 90-degree Peel Test was used to examine the bond strength of the specimens. A SATEC tensile test machine was used with a 2000 lb. load cell

catena-Poly[[[4,6-bis­(2-pyrid­yl)-1,3,5-triazin-2-olato]copper(II)]-μ-chlorido

PubMed Central

Cao, Man-Li

2011-01-01

The title compound, [Cu(C13H8N5O)Cl]n, has a chain structure parallel to [100] with Cu2+ cations in a trigonal–bipyramidal coordination environment. The ligand adopts a tridentate tripyridyl coordination mode and a chloride ion acts as a bridge. The chains are linked via weak C—H⋯O and C—H⋯Cl hydrogen bonds into a three-dimensional supra­molecular network. PMID:21754632

Surfacing Rescue Container Concept Design for Trident Submarines

DTIC Science & Technology

2009-05-08

crew of their decompression obligation and will give undersea medical officers (UMO) on land the information they need to treat the crew upon arrival...ard . B ead boa ) Ba wit to ntly ora sa en s o is d OX ld er s h ule los is e v of t . L ec pu tin tte hin ad a te fety den f s to ma t...Technical Information Service, 1970. [34] SURVIVEX 2003, Exercise Tests Disabled Submarine Survival. Horn, Wayne G. 1, s.l. : Undersea Warfare

An Application of Fuzzy Logic Control to a Classical Military Tracking Problem

DTIC Science & Technology

1994-05-19

34, Fuzzy Sets and Systems, vol.4., 1980, pp.13-30. Berenji , Hamid R . and Pratap Khedkar. "Learning and Tuning Fuzzy Logic Controllers Through...A TRIDENT SCHOLAR PROJECT REPORT" NO. 222 "An Application of Fuzzy Logic Control to a Classical Military Tracking Problem" DTIC •S r F UNITED STATES...Zq qAvail andlor ____________________I__________ Dist SpecialDate USNA- 1531-2 REPORT DOCUMENTATION PAGE r •,,,op APmw OMB no. 0704.0188 ¢iQiiati~m.f

Spectral Characterization and 3D Molecular Modeling Studies of Metal Complexes Involving the O, N-Donor Environment of Quinazoline-4(3H)-one Schiff Base and Their Biological Studies

PubMed Central

Siddappa, Kuruba; Mane, Sunilkumar B.

2014-01-01

A simple condensation of 3-amino-2-methylquinazoline-4-one with 2-hydroxy-1-naphthaldehyde produced new tridentate ONO donor Schiff base ligand with efficient yield. The structural characterization of ligand and its Cu(II), Ni(II), Co(II), Mn(II), Zn(II), and Cd(II) complexes were achieved by the aid of elemental analysis, spectral characterization such as (UV-visible, IR, NMR, mass, and ESR), and magnetic data. The analytical and spectroscopic studies suggest the octahedral geometries of Cu(II), Co(II), Ni(II) and Mn(II) complexes and tetrahedral geometry of Zn(II) and Cd(II) complexes with the tridentate ONO Schiff base ligand. Furthermore, the conclusions drawn from these studies afford further support to the mode of bonding discussed on the basis of their 3D molecular modeling studies by considering different bond lengths, bond angles, and bond distance. The ligand and its metal complexes evaluated for their antimicrobial activity against Staphylococcus aureus (MTCC number 7443), Bacillus subtilis (MTCC number 9878), Escherichia coli (MTCC number 1698), Aspergillus niger (MTCC number 281), and Aspergillus flavus (MTCC number 277). The MIC of these compounds was found to be most active at 10 μg/mL concentration in inhibiting the growth of the tested organisms. The DNA cleavage activity of all the complexes was studied by gel electrophoresis method. PMID:24678278

Synthesis, spectral, thermal and antimicrobial studies on cobalt(II), nickel(II), copper(II), zinc(II) and palladium(II) complexes containing thiosemicarbazone ligand

NASA Astrophysics Data System (ADS)

El-Sawaf, Ayman K.; El-Essawy, Farag; Nassar, Amal A.; El-Samanody, El-Sayed A.

2018-04-01

The coordination characteristic of new N4-morpholinyl isatin-3-thiosemicarbazone (HL) towards Co(II), Ni(II), Cu(II), Zn(II) and Pd(II) has been studies. The structures of the complexes were described by elemental analyses, molar conductivity, magnetic, thermal and spectral (IR, UV-Vis, 1H and 13C NMR and ESR) studies. On the basis of analytical and spectral studies the ligand behaves as monobasic tridentate ONS donor forming two five membered rings towards cobalt, copper and palladium and afforded complexes of the kind [M(L)X], (Mdbnd Co, Cu or Pd; Xdbnd Cl, Br or OAc). Whereas the ligand bound to NiCl2 as neutral tridentate ONS donor and with ZnCl2 as neutral bidentate NS donor. The newly synthesized thiosemicarbazone ligand and some of its complexes were examined for antimicrobial activity against 2 gram negative bacterial strains (Escherichia coli Pseudomonas and aeruginosa), 2 gram positive bacterial strains (Streptococcus pneumoniae and Staphylococcus aureus)} and two Pathogenic fungi (Aspergillus fumigatus and Candida albicans). All metal complexes possess higher antimicrobial activity comparing with the free thiosemicarbazone ligand. The high potent activities of the complexes may arise from the coordination and chelation, which tends to make metal complexes act as more controlling and potent antimicrobial agents, thus hindering the growing of the microorganisms. The antimicrobial results also show that copper bromide complex is better antimicrobial agent as compared to the Schiff base and its metal complexes.

Complexation of NpO2+ with (2-Hydroxyethyl)ethylenediaminetriacetic Acid (HEDTA) in Aqueous Solutions: Thermodynamic Studies and Structural Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xingliang; Zhang, Zhicheng; Martin, Leigh R

Complexation of Np(V) with N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) was studied in aqueous solution (I = 1.0 mol L -1 NaClO 4, t = 25 °C) by spectrophotometry, microcalorimetry and Extended X-ray absorption fine structure (EXAFS) spectroscopy. Equilibrium constants for the formation of three complexes, NpO 2L 2-, NpO 2(HL) -, and (NpO 2)2(OH)2L26 -, were determined to be (6.91 ± 0.06), (4.28 ± 0.03) and -(4.93 ± 0.03), respectively. The enthalpies of complexation were determined to be -(8.0 ± 2.0) kJ mol -1 for NpO 2L 2 - and -(2.2 ± 2.0) kJ mol-1 for NpO 2(HL) -. Thermodynamic data ofmore » the complexation of Np(V) with HEDTA were compared to those of Np(V) with other aminopolycarboxylic acids, gaining insight into the possible coordination modes of the complexes. The EXAFS studies provided further structural information on those modes. In both NpO 2L 2 - and NpO 2(HL) - complexes, HEDTA coordinates to Np(V) in a tridentate mode through two oxygens of two carboxylic groups and one nitrogen of the amine group. In the (NpO 2) 2(OH) 2L 2 6- complex, two Np(V) atoms are bridged by two hydroxides and each HEDTA maintains the tridentate coordination mode.« less

New copper(II) complexes with dopamine hydrochloride and vanillymandelic acid: Spectroscopic and thermal characterization

NASA Astrophysics Data System (ADS)

Mohamed, Gehad G.; Nour El-Dien, F. A.; El-Nahas, R. G.

2011-10-01

The dopamine derivatives participate in the regulation of wide variety of physiological functions in the human body and in medication life. Increase and/or decrease in the concentration of dopamine in human body reflect an indication for diseases such as Schizophrenia and/or Parkinson diseases. The Cu(II) chelates with coupled products of dopamine hydrochloride (DO.HCl) and vanillymandelic acid (VMA) with 4-aminoantipyrine (4-AAP) are prepared and characterized. Different physico-chemical techniques namely IR, magnetic and UV-vis spectra are used to investigate the structure of these chelates. Cu(II) forms 1:1 (Cu:DO) and 1:2 (Cu:VMA) chelates. DO behave as a uninegative tridentate ligand in binding to the Cu(II) ion while VMA behaves as a uninegative bidentate ligand. IR spectra show that the DO is coordinated to the Cu(II) ion in a tridentate manner with ONO donor sites of the phenolic- OH, -NH and carbonyl- O, while VMA is coordinated with OO donor sites of the phenolic- OH and -NH. Magnetic moment measurements reveal the presence of Cu(II) chelates in octahedral and square planar geometries with DO and VMA, respectively. The thermal decomposition of Cu(II) complexes is studied using thermogravimetric (TG) and differential thermal analysis (DTA) techniques. The activation thermodynamic parameters, such as, energy of activation, enthalpy, entropy and free energy change of the complexes are evaluated and the relative thermal stability of the complexes are discussed.

Complexation of NpO2+ with (2-Hydroxyethyl)ethylenediaminetriacetic Acid (HEDTA) in Aqueous Solutions: Thermodynamic Studies and Structural Analysis

DOE PAGES

Li, Xingliang; Zhang, Zhicheng; Martin, Leigh R; ...

2016-12-02

Complexation of Np(V) with N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) was studied in aqueous solution (I = 1.0 mol L -1 NaClO 4, t = 25 °C) by spectrophotometry, microcalorimetry and Extended X-ray absorption fine structure (EXAFS) spectroscopy. Equilibrium constants for the formation of three complexes, NpO 2L 2-, NpO 2(HL) -, and (NpO 2)2(OH)2L26 -, were determined to be (6.91 ± 0.06), (4.28 ± 0.03) and -(4.93 ± 0.03), respectively. The enthalpies of complexation were determined to be -(8.0 ± 2.0) kJ mol -1 for NpO 2L 2 - and -(2.2 ± 2.0) kJ mol-1 for NpO 2(HL) -. Thermodynamic data ofmore » the complexation of Np(V) with HEDTA were compared to those of Np(V) with other aminopolycarboxylic acids, gaining insight into the possible coordination modes of the complexes. The EXAFS studies provided further structural information on those modes. In both NpO 2L 2 - and NpO 2(HL) - complexes, HEDTA coordinates to Np(V) in a tridentate mode through two oxygens of two carboxylic groups and one nitrogen of the amine group. In the (NpO 2) 2(OH) 2L 2 6- complex, two Np(V) atoms are bridged by two hydroxides and each HEDTA maintains the tridentate coordination mode.« less

Reactivity of tris(acetylacetonato) iron(III) with tridentate [ONO] donor Schiff base as an access to newer mixed-ligand iron(III) complexes.

PubMed

Bhattacharjee, Chira R; Goswami, Pankaj; Pramanik, Harun A R; Paul, Pradip C; Mondal, Paritosh

2011-05-01

Two new mixed-ligand iron(III) complexes, [Fe(L(n))(acac)(C(2)H(5)OH)] incorporating coordinated ethanol from the reaction solvent were accessed from the reaction of [Fe(acac)(3)] with [ONO] donor dibasic tridentate unsymmetrical Schiff base ligands derived from condensation of 2-hydroxy-1-napthaldehyde with 2-aminophenol (H(2)L(1)) or 2-aminobenzoic acid (H(2)L(2)). The thermal study (TGA-DTA) provided evidence for weakly bound ethanol which is readily substituted by neutral N-donor molecule imidazole, benzimidazole or pyridine to produce an array of newer complexes, [Fe(L(n))(acac)X] (n=1, 2; X=Im, Bim, Py). The compounds were characterized by elemental analyses, FT-IR, UV-vis, solution electrical conductivity, FAB mass, (1)H and (13)C NMR spectroscopy. Room temperature magnetic susceptibility measurements (μ(eff)∼5.8 B.M.) are consistent with spin-free octahedral iron(III) complexes. Cyclic voltammetry of ethanol complexes revealed a quasi-reversible one electron redox response (ΔE(p)>100 mV) for the Fe(III)/Fe(II) couple. Low half wave redox potential (E(1/2)) values suggested easy redox susceptibility. The ground state geometries of the ethanol and imidazole complexes have been ascertained to be distorted octahedral by density functional theory using DMol3 program at BLYP/DNP level. Copyright © 2011 Elsevier B.V. All rights reserved.

Experimental and textural constraints on mafic enclave formation in volcanic rocks

USGS Publications Warehouse

Coombs, M.L.; Eichelberger, J.C.; Rutherford, M.J.

2002-01-01

We have used experiments and textural analysis to investigate the process of enclave formation during magma mixing at Southwest Trident volcano, Alaska. Andesite enclaves are present throughout the four dacite lava flows produced by the eruption, and resemble mafic enclaves commonly found in other volcanic rocks. Our experiments replicate the pressure-temperature-time path taken by enclave-forming andesite magma as it is engulfed in dacite during magma mixing. Pressure and temperature information for the andesite and dacite are from [Coombs et al., Contrib. Mineral. Petrol. 140 (2000) 99-118]. The andesite was annealed at 1000??C, and then cooled to 890??C at rates of 110??C h1, 10??C h1 and 2??C h1. Once cooled to 890??C, andesite was held at this lower temperature from times ranging from 1 to 40 h. The andesite that was cooled at the slower rates of 2??C h1 and 10??C h1 most resembles enclave groundmass texturally and compositionally. Based on simple thermal calculations, these rates are more consistent with cooling of the andesite groundmass below an andesite-dacite interface than with cooling of enclave-sized spheres. If enclaves do crystallize as spheres, post-crystallization disaggregation must occur. Calculations using the MELTS algorithm [Ghiorso and Sack, Contrib. Mineral. Petrol. 119 (1995) 197-212] show that for incoming andesite to become less dense than the dacite to become less dense ???34 volume % of its groundmass must crystallize to undergo~18 volume % vesiculation; these values are similar to those determined for Southwest Trident enclaves. Thus such crystallization may lead to 'flotation' of enclaves and be a viable mechanism for enclave formation and dispersal. The residual melt in the cooling experiments did not evolve to rhyolitic compositions such as seen in natural enclaves due to a lack of a decompression step in the experiments. Decompression experiments on Southwest Trident dacite suggest an average ascent rate for the eruption of ???2-3 MPa h1. An andesite experiment that was cooled and then decompressed at this rate contains melt that matches that of the natural enclaves. It is apparent that decompression (ascent)-induced crystallization occurs in enclaves, but not in the form of microlites as happens in the dacite host, due either to insufficient residence time at chamber temperatures or to the pre-existing microphenocrysts which act as sites for new growth. ?? 2002 Elsevier Science B.V. All rights reserved.

Inertial Confinement Fusion Annual Report 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Correll, D

The ICF Annual Report provides documentation of the achievements of the LLNL ICF Program during the fiscal year by the use of two formats: (1) an Overview that is a narrative summary of important results for the fiscal year and (2) a compilation of the articles that previously appeared in the ICF Quarterly Report that year. Both the Overview and Quarterly Report are also on the Web at http://lasers.llnl.gov/lasers/pubs/icfq.html. Beginning in Fiscal Year 1997, the fourth quarter issue of the ICF Quarterly was no longer printed as a separate document but rather included in the ICF Annual. This change providedmore » a more efficient process of documenting our accomplishments with-out unnecessary duplication of printing. In addition we introduced a new document, the ICF Program Monthly Highlights. Starting with the September 1997 issue and each month following, the Monthly Highlights will provide a brief description of noteworthy activities of interest to our DOE sponsors and our stakeholders. The underlying theme for LLNL's ICF Program research continues to be defined within DOE's Defense Programs missions and goals. In support of these missions and goals, the ICF Program advances research and technology development in major interrelated areas that include fusion target theory and design, target fabrication, target experiments, and laser and optical science and technology. While in pursuit of its goal of demonstrating thermonuclear fusion ignition and energy gain in the laboratory, the ICF Program provides research and development opportunities in fundamental high-energy-density physics and supports the necessary research base for the possible long-term application of inertial fusion energy for civilian power production. ICF technologies continue to have spin-off applications for additional government and industrial use. In addition to these topics, the ICF Annual Report covers non-ICF funded, but related, laser research and development and associated applications. We also provide a short summary of the quarterly activities within Nova laser operations, Beamlet laser operations, and National Ignition Facility laser design. LLNL's ICF Program falls within DOE's national ICF program, which includes the Nova and Beamlet (LLNL), OMEGA (University of Rochester Laboratory for Laser Energetics), Nike (Naval Research Laboratory), and Trident (Los Alamos National Laboratory) laser facilities. The Particle Beam Fusion Accelerator (Z) and Saturn pulsed-power facilities are at Sandia National Laboratories. General Atomics, Inc., develops and provides many of the targets for the above experimental facilities. Many of the ICF Annual Report articles are co-authored with our colleagues from these other ICF institutions.« less

Bis(2,3,5,6-tetra-2-pyridyl­pyrazine-κ3 N 2,N 1,N 6)nickel(II) dithio­cyanate dihydrate

PubMed Central

De la Pinta, Noelia; Fidalgo, M. Luz; Ezpeleta, José M.; Cortés, Roberto; Madariaga, Gotzon

2011-01-01

In the title compound, [Ni(C24H16N6)2](NCS)2·2H2O, the central NiII ion is octahedrally coordinated by six N atoms of two tridentate 2,3,5,6-tetra-2-pyridyl­pyrazine ligands (tppz). Two thio­cyanate anions act as counter-ions and two water mol­ecules act as solvation agents. O—H⋯N hydrogen bonds are observed in the crystral structure. PMID:21522540

Chiral allene-containing phosphines in asymmetric catalysis

PubMed Central

Cai, Feng; Pu, Xiaotao; Qi, Xiangbing; Lynch, Vincent; Radha, Akella; Ready, Joseph M.

2011-01-01

Traditionally, ligands used in asymmetric catalysis have contained either stereogenic atoms or hindered single bonds (atropisomerism), or both. Here we demonstrate that allenes, chiral 1,2-dienes, appended with basic functionality can serve as ligands for transition metals. We describe an allene-containing bisphosphine that, when coordinated to Rh(I), promotes the asymmetric addition of aryl boronic acids to α-keto esters with high enantioselectivity. Solution and solid-state structural analysis reveals that one olefin of the allene can coordinate to transition metals generating bi- and tri-dentate ligands. PMID:21972824

catena-Poly[copper(II)-mu-L-tyrosyl-L-leucinato].

PubMed

Baggio, Ricardo; Casado, Nieves M C; Calvo, Rafael; Rapp, Raul E; Garland, María Teresa

2005-05-01

In the title compound, [Cu(C15H20N2O4)]n, the copper(II) coordination is square planar. The anionic L-tyrosyl-L-leucinate ligand binds in an N,N',O-tridentate mode to one Cu(II) cation on one side and in an O-monodentate mode to a second Cu(II) cation on the other side, thus defining -Cu-O-C-O-Cu'- chains which run along the a axis. These chains are held together by a strong hydrogen bond involving the hydroxy H atom.

Bis(6-meth-oxy-2-{[tris-(hydroxy-meth-yl)-meth-yl]-imino-meth-yl}phenolato)-copper(II) dihydrate.

PubMed

Zhang, Xiutang; Wei, Peihai; Dou, Jianmin; Li, Bin; Hu, Bo

2009-01-08

In the title compound, [Cu(C(12)H(16)NO(5))(2)]·2H(2)O, the Cu(II) ion adopts a trans-CuN(2)O(4) octa-hedral geometry arising from two N,O,O'-tridentate 6-meth-oxy-2-{[tris-(hydroxy-meth-yl)meth-yl]-imino-meth-yl}phenolate ligands. The Jahn-Teller distortion of the copper centre is unusally small. In the crystal structure, O-H⋯O hydrogen bonds, some of which are bifurcated, link the component species.

An Investigation Into the Feasibility of Using a Modern Gravity Gradient Instrument for Passive Aircraft Navigation and Terrain Avoidance

DTIC Science & Technology

2009-03-01

the research objectives for this study are presented. It should be noted that sensor cost was not considered for this study. Additionally, further...development costs ) for gravity compensation require- ments of its trident submarine inertial navigation systems and by the Air Force Geo- physics...52]: T (r, φ, λ) = GM ae Nmax∑ n=2 n∑ m=0 (a r )n+1 (Cnm cosmλ+ Snm sinmλ)P nm(cos φ) (31) 44 where r, φ, λ are the geocentric distance, lattitude and

1,1,1-tris(hydroxymethyl)ethane as a new, efficient, and versatile tripod ligand for copper-catalyzed cross-coupling reactions of aryl iodides with amides, thiols, and phenols.

PubMed

Chen, Yao-Jung; Chen, Hsin-Hung

2006-11-23

1,1,1-tris(hydroxymethyl)ethane was presented as a new, efficient, and versatile tridentate O-donor ligand suitable for the copper-catalyzed formation of C-N, C-S, and C-O bonds. This inexpensive and commercially available tripod ligand has been demonstrated to facilitate the copper-catalyzed cross-coupling reactions of aryl iodides with amides, thiols, and phenols to afford the corresponding desired products in good to excellent yields. [reaction: see text].

Surfacing Rescue Container Concept Design for Trident Submarines

DTIC Science & Technology

2009-06-01

crew of their decompression obligation and will give undersea medical officers (UMO) on land the information they need to treat the crew upon arrival...ard . B ead boa ) Ba wit to ntly ora sa en s o is d OX ld er s h ule los is e v of t . L ec pu tin tte hin ad a te fety den f s to ma t...Information Service, 1970. [34] SURVIVEX 2003, Exercise Tests Disabled Submarine Survival. Horn, Wayne G. 1, s.l. : Undersea Warfare, 2003, Vol. 6, pp

Earthquake studies reveal the magmatic plumbing system of the Katmai volcanoes

USGS Publications Warehouse

Thurber, Clifford; Murphy, Rachel; Prejean, Stephanie G.; Haney, Matthew M.; Bennington, Ninfa; Powell, Lee; Paskievitch, John F.

2012-01-01

Our main finding is that there is not a single large anomalous zone centered beneath Katmai Pass; rather there are several separate anomalous zones, one each beneath Katmai, Trident-Novarupta, and Martin-Mageik. Furthermore, the earthquakes are tightly clustered beneath the various volcanic centers, and are found to be systematically deeper than previously thought. Linear trends of earthquakes are also revealed, similar to features observed at other volcanoes, possibly outlining previously unidentified fault structures or indicating the path of migrating magma or magmatic fluids and gases.

Iridium-Catalyzed Asymmetric Hydrogenation of Ketones with Accessible and Modular Ferrocene-Based Amino-phosphine Acid (f-Ampha) Ligands.

PubMed

Yu, Jianfei; Long, Jiao; Yang, Yuhong; Wu, Weilong; Xue, Peng; Chung, Lung Wa; Dong, Xiu-Qin; Zhang, Xumu

2017-02-03

A series of tridentate ferrocene-based amino-phosphine acid (f-Ampha) ligands have been successfully developed. The f-Ampha ligands are extremely air stable and exhibited excellent performance in the Ir-catalyzed asymmetric hydrogenation of ketones (full conversions, up to >99% ee, and 500 000 TON). DFT calculations were performed to elucidate the reaction mechanism and the importance of the -COOH group. Control experiments also revealed that the -COOH group played a key role in this reaction.

Development of Technologies to Utilize Laser Plasma Radiations Sources for Radiation Effects Sciences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, J F

2007-01-31

This final report will cover work performed over the period of November 11, 2005 to September 30, 2006 on the contract to develop technologies using laser sources for radiation effects sciences. The report will discuss four topic areas; the laser source experiments on the Gekko Laser at Osaka, Japan, planning for the Charge State Freeze Out experiments to be performed in calendar year 2007, a review of previous xenon gasbags on the LANL Trident laser to provide planning support to the May-June 2007 HELEN experiments.

Gold(III) complexes with ONS-Tridentate thiosemicarbazones: Toward selective trypanocidal drugs.

PubMed

Rettondin, Andressa R; Carneiro, Zumira A; Gonçalves, Ana C R; Ferreira, Vanessa F; Oliveira, Carolina G; Lima, Angélica N; Oliveira, Ronaldo J; de Albuquerque, Sérgio; Deflon, Victor M; Maia, Pedro I S

2016-09-14

Tridentate thiosemicarbazone ligands with an ONS donor set, H2L(R) (R = Me and Et) were prepared by reactions of 1-phenyl-1,3-butanedione with 4-R-3-thiosemicarbazides. H2L(R) reacts with Na[AuCl4]·2H2O in MeOH in a 1:1 M ratio under formation of green gold(III) complexes of composition [AuCl(L(R))]. These compounds represent the first examples of gold(III) complexes with ONS chelate-bonded thiosemicarbazones. The in vitro anti-Trypanosoma cruzi activity against both trypomastigote and amastigote forms (IC50try/ama) of CL Brener strains as well as the cytotoxicity against LLC-MK2 cells of the free ligands and complexes was evaluated. The complex [AuCl(L(Me))] was found to be more active and more selective than its precursor ligand and the standard drug benznidazole with a SItry/ama value higher than 200, being considered as a lead candidate for Chagas disease treatment. Moreover the in vitro activity against the replicative amastigote form (IC50ama) of T. cruzi was additionally investigated revealing that [AuCl(L(Me))] was also more potent than benznidazole still with a similar selectivity index. Finally, docking studies showed that free ligands and complexes interact with the same residues of the parasite protease cruzain but with different intensities, suggesting that this protease could be a possible target for the trypanocidal action of the obtained compounds. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

At the Borderline between Metal-Metal Mixed Valency and a Radical Bridge Situation: Four Charge States of a Diruthenium Complex with a Redox-Active Bis( mer-tridentate) Ligand.

PubMed

Mondal, Sudipta; Schwederski, Brigitte; Frey, Wolfgang; Fiedler, Jan; Záliš, Stanislav; Kaim, Wolfgang

2018-04-02

The complex ions [L 3 Ru(μ,η 3 :η 3 -BL)RuL 3 ] n+ (1 n+ , L 3 = 4,4',4″-tri- tert-butyl-2,6,2',6″-terpyridine and H 2 BL 2- = 1,2-bis(salicyloyl)hydrazide(2-)) were isolated with PF 6 - or ClO 4 - counterions ( n = 1) and as bis(hexafluorophosphate) ( n = 2). Structural, electrochemical, and spectroscopic characterization reveals the monocation as intermediate ( K c = 10 8.2 ) in the three-step reversible redox system 1 0/+/2+/3+ . The 1 + ion has the molecule-bridged (Ru- - -Ru 4.727 Å) ruthenium centers involved in five- and six-membered chelate rings, and it exhibits long-wavelength absorptions at λ max 2240, 1660, and 1530 nm (ε max = 1000, 3000, and 8000 M -1 cm -1 , respectively), which would be compatible with a Ru III Ru II mixed-valent situation or with a coordinated radical ion bridge. In fact, EPR and DFT analysis of 1 + reveals that the spin is equally distributed over the ligand bridge and over both metals. The oxidized paramagnetic ions 1 2+ and 1 3+ have been studied by 1 H NMR and EPR and by TD-DFT supported UV-vis-NIR and MIR (mid-IR) spectroelectrochemistry. The capacity of various kinds of bis( mer-tridentate) bridging ligands (π donors or π acceptors, cyclometalated or noncyclometalated) for mediating metal-metal interactions is discussed.

Characterization and biological studies on Co(II), Ni(II) and Cu(II) complexes of carbohydrazones ending by pyridyl ring.

PubMed

Abu El-Reash, G M; El-Gammal, O A; Ghazy, S E; Radwan, A H

2013-03-01

The chelating behavior of ligands based on carbohydrazone core modified with pyridine end towards Co(II), Ni(II) and Cu(II) ions have been examined. The ligands derived from the condensation of carbohydrazide with 2-acetylpyridine (H(2)APC) and 4-acetylpyridine (H(2)APEC). The (1)H NMR, IR data and the binding energy calculations of H(2)APC revealed the presence of two stereoisomers syn and anti in the solid state and in the solution. The (1)H NMR, IR data and the binding energy calculations confirmed the presence of H(2)APEC in one keto form only in the solid state and in the solution. The spectroscopic data confirmed that H(2)APC behaves as a monobasic pentadentate in Co(II) and Cu(II) complexes and as mononegative tetradentate in Ni(II) complex. On the other hand, H(2)APEC acts as a mononegative tridentate in Co(II) complex, neutral tridentate in Ni(II) complex and neutral bidentate in Cu(II) complex. The electronic spectra and the magnetic measurements of complexes as well as the ESR of the copper complexes suggested the octahedral geometry. The bond length and bond angles were evaluated by DFT method using material studio program. The thermal behavior and the kinetic parameters of degradation were determined using Coats-Redfern and Horowitz-Metzger methods. The antioxidant (DDPH and ABTS methods), anti-hemolytic and in vitro Ehrlich ascites of the compounds have been screened. Copyright © 2012 Elsevier B.V. All rights reserved.

Low temperature X-ray structure analyses combined with NBO studies of a new heteroleptic octa-coordinated Holmium(III) complex with N,N,N-tridentate hydrazono-phthalazine-type ligand

NASA Astrophysics Data System (ADS)

Soliman, Saied M.; El-Faham, Ayman

2018-04-01

The new heteroleptic [HoL(H2O)5]Br3 complex, L is hydrazono-phthalazine ligand, is synthesized and its molecular structure aspects were analyzed using single crystal X-ray structure (SCXRD), Hirshfeld (HF) analysis, quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) method. The SCXRD showed that the Ho is octa-coordinated with one N,N,N-tridentate ligand L and five water molecules. The HF analysis is used to analyze the molecular packing in the [HoL(H2O)5]Br3crystal structure. The complex cations are connected via strong Osbnd H⋯Br and Nsbnd H⋯Br H-bonding interactions which have greater importance than the Csbnd H⋯Br contacts. Also, all the Hosbnd N and Hosbnd O bonds have the characteristics of closed shell interactions using QTAIM. The natural orbitals included in these interactions were analyzed using NBO method. The alpha LP*(8)Ho and beta LP*(4)Ho which have mainly s-orbital characters are the most important anti-bonding natural orbitals included in all Ho-N and Hosbnd O bonds. The rest of the Ho anti-bonding orbitals which have either p or d-orbital characters shared partially in the Ho-ligands interactions. Natural charges analysis revealed the presence of significant amount of electron density (0.9225-0.9300 e) transferred from the ligands to Ho (2.0700-2.0775 e). Spherical spin density with ∼4.0 e is predicted over the Ho atom.

Two mixed-ligand lanthanide–hydrazone complexes: [Pr(NCS)3(pbh)2]·H2O and [Nd(NCS)(NO3)(pbh)2(H2O)]NO3·2.33H2O [pbh is N′-(pyridin-2-ylmethylidene)benzo­hydrazide, C13H11N3O

PubMed Central

Paschalidis, Damianos G.; Harrison, William T. A.

2016-01-01

The gel-mediated syntheses and crystal structures of [N′-(pyridin-2-ylmethylidene-κN)benzohydrazide-κ2 N′,O]tris(thiocyanato-κN)praseodymium(III) mono­hydrate, [Pr(NCS)3(C13H11N3O)2]·H2O, (I), and aqua(nitrato-κ2 O,O′)[N′-(pyri­din-2-ylmethylidene-κN)benzohydrazide-κ2 N′,O](thiocyanato-κN)neo­dym­ium(III) nitrate 2.33-hydrate, [Nd(NCS)(NO3)(C13H11N3O)2(H2O)]NO3·2.33H2O, (II), are reported. The Pr3+ ion in (I) is coordinated by two N,N,O-tridentate N′-(pyridin-2-ylmethylidene)benzohydrazide (pbh) ligands and three N-bonded thio­cyanate ions to generate an irregular PrN7O2 coordination polyhedron. The Nd3+ ion in (II) is coordinated by two N,N,O-tridentate pbh ligands, an N-bonded thio­cyanate ion, a bidentate nitrate ion and a water mol­ecule to generate a distorted NdN5O5 bicapped square anti­prism. The crystal structures of (I) and (II) feature numerous hydrogen bonds, which lead to the formation of three-dimensional networks in each case. PMID:26958385

Differential Denaturation of Serum Proteome Reveals a Significant Amount of Hidden Information in Complex Mixtures of Proteins

PubMed Central

Polci, Maria Letizia; Rossi, Stefania; Cordella, Martina; Carlucci, Giuseppe; Marchetti, Paolo; Antonini-Cappellini, Giancarlo; Facchiano, Antonio; D'Arcangelo, Daniela; Facchiano, Francesco

2013-01-01

Recently developed proteomic technologies allow to profile thousands of proteins within a high-throughput approach towards biomarker discovery, although results are not as satisfactory as expected. In the present study we demonstrate that serum proteome denaturation is a key underestimated feature; in fact, a new differential denaturation protocol better discriminates serum proteins according to their electrophoretic mobility as compared to single-denaturation protocols. Sixty nine different denaturation treatments were tested and the 3 most discriminating ones were selected (TRIDENT analysis) and applied to human sera, showing a significant improvement of serum protein discrimination as confirmed by MALDI-TOF/MS and LC-MS/MS identification, depending on the type of denaturation applied. Thereafter sera from mice and patients carrying cutaneous melanoma were analyzed through TRIDENT. Nine and 8 protein bands were found differentially expressed in mice and human melanoma sera, compared to healthy controls (p<0.05); three of them were found, for the first time, significantly modulated: α2macroglobulin (down-regulated in melanoma, p<0.001), Apolipoprotein-E and Apolipoprotein-A1 (both up-regulated in melanoma, p<0.04), both in mice and humans. The modulation was confirmed by immunological methods. Other less abundant proteins (e.g. gelsolin) were found significantly modulated (p<0.05). Conclusions: i) serum proteome contains a large amount of information, still neglected, related to proteins folding; ii) a careful serum denaturation may significantly improve analytical procedures involving complex protein mixtures; iii) serum differential denaturation protocol highlights interesting proteomic differences between cancer and healthy sera. PMID:23533572

Four unprecedented 2D trinuclear Mn(II)-complexes with adenine nucleobase controlled by solvent or co-ligand: Hydrothermal synthesis, crystal structure and magnetic behaviour

NASA Astrophysics Data System (ADS)

Zhao, Hongkun; He, Hongming; Wang, Xiuguang; Liu, Zhongyi; Ding, Bo; Yang, Hanwen

2018-03-01

Four unique infinite 2D Mn(II) aggregates, [Mn3(μ3-ade)2(OAc)4X]n (X = DMF for 1, DMA for 2 and C2H5O- for 3), [Mn3(μ3-ade)2(ap)2DMF]n (4) (Hade = adenine; DMF = N,N-dimethylformamide; DMA = N,N-dimethylacetamide, OAc- = acetate ion, H2ap = adipic acid) with trinuclear Mn(II) as secondary building units (SBUs), have been successfully synthesized by the assembly of Hade nucleobase and manganese acetate under solvothermal conditions. The resultant complexes can be applied to explore the influence of solvent or co-ligands on the self-assembly and properties of metal complexes based on adenine. The Hade represent tridentate μ3-N3, N7, N9 bridging coordination modes. The acetate anions exhibit μ2-η1:η1 bidentate, μ2-η1:η2 tridentate mode, and μ2-η0:η2 bidentate mode. The adipate anions in complex 4 adopt two coordination modes: one is μ4-η2:η1:η1:η1 pentadentate mode, the other one is μ3-η1:η2:η2:η1 hexadentate mode. Their magnetic behaviors exhibit interesting variations, in which the local net magnetization at low temperature increases from 1 to 3. The MnII3 SBUs in 1-3 are symmetric with an inversion center, whereas that in 4 has three crystallographically independent MnII atoms. Thus, the magnetic behaviors of 4 are different from complex 1-3.

Co(II), Ni(II), Cu(II) and Zn(II) complexes of tridentate ONO donor Schiff base ligand: Synthesis, characterization, thermal, non-isothermal kinetics and DFT calculations

NASA Astrophysics Data System (ADS)

Kusmariya, Brajendra S.; Mishra, A. P.

2017-02-01

We report here four mononuclear Co(II), Ni(II), Cu(II) and Zn(II) coordination compounds of general formula [M(L)2] {L = dcp; M = CoII, CuII & ZnII} and [M(L)(H2O)]·H2O {L = dcp; M = NiII} derived from tridentate 2,4-dichloro-6-{[(3-chloro-2-hydroxy-5-nitrophenyl)imino]methyl}phenol (dcp) ligand. These compounds were synthesized and characterized by elemental analysis, FT-IR, uv-vis, 1H NMR, molar conductance, magnetic moment, thermal, PXRD and SEM-EDX. The Powder X-ray Diffraction patterns and SEM analyses showed the crystalline nature of synthesized compounds. The peak broadening was explained in terms of crystallite size and the lattice strain using Scherrer and Williamson-Hall method. Thermogravimetric analysis was performed to determine the thermal stability of synthesized compounds under nitrogen atmosphere up to 820 K at 10 Kmin-1 heating rate. The kinetic and thermodynamic parameters of thermal decomposition were calculated using Coats-Redfern (C-R), Piloyan-Novikova (P-N) and Horowitz-Metzger (H-M) methods assuming first order degradation. The calculated optical band gap values of complexes were found to be in semiconducting range. To support the experimental findings, and derive some fruitful information viz. frequency calculations, HOMO-LUMO, energy gap (ΔE), molecular electrostatic potential (MEP), spin density, absorption spectra etc.; theoretical calculations by means of DFT and TD-DFT at B3LYP level were incorporated.

The ligand effect on the hydrolytic reactivity of Zn(II) complexes toward phosphate diesters.

PubMed

Bonfá, Lodovico; Gatos, Maddalena; Mancin, Fabrizio; Tecilla, Paolo; Tonellato, Umberto

2003-06-16

The catalytic effects of the Zn(II) complexes of a series of poliaminic ligands in the hydrolysis of the activated phosphodiesters bis-p-nitrophenyl phosphate (BNP) and 2-hydroxypropyl-p-nitrophenyl phosphate (HPNP) have been investigated. The reactions show first-order rate dependency on both substrate and metal ion complex and a pH dependence which is diagnostic of the acid dissociation of the reactive species. The mechanism of the metal catalyzed transesterification of HPNP has been assessed by solvent isotopic kinetic effect studies and involves the intramolecular nucleophilic attack of the substrate alcoholic group, activated by metal ion coordination. The intrinsic reactivity of the different complexes is controlled by the nature and structure of the ligand: complexes of tridentate ligands, particularly if characterized by a facial coordination mode, are more reactive than those of tetradentate ligands which can hardly allow binding sites for the substrate. In the case of tridentate ligands that form complexes with a facial coordination mode, a linear Brønsted correlation between the reaction rate (log k) and the pK(a) of the active nucleophile is obtained. The beta(nuc) values are 0.75 for the HPNP transesterification and 0.20 for the BNP hydrolysis. These values are indicated as the result of the combination of two opposite Lewis acid effects of the Zn(II) ion: the activation of the substrate and the efficiency of the metal coordinated nucleophile. The latter factor apparently prevails in determining the intrinsic reactivity of the Zn(II) complexes.

Aqua­(dicyanamido-κN 1)(nitrato-κ2 O,O′)(2,3,5,6-tetra-2-pyridylpyrazine-κ3 N 2,N 1,N 6)manganese(II)

PubMed Central

Callejo, Lorena; De la Pinta, Noelia; Vitoria, Pablo; Cortés, Roberto

2009-01-01

In the title compound, [Mn(C2N3)(NO3)(C24H16N6)(H2O)], the central manganese(II) ion is hepta­coordinated to a tridentate 2,3,5,6-tetra-2-pyridylpyrazine ligand (tppz), a bidentate nitrate ligand, a terminal monodentate dicyanamide ligand (dca) and a water mol­ecule. The structure contains isolated neutral complexes, which are linked by O(water)—H⋯N hydrogen bonds generating chains along [010]. PMID:21581535

KSC-2009-2559

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – The mockup Orion crew exploration vehicle is lowered into the water at the Trident Basin at Port Canaveral, Fla., for testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

KSC-2009-2557

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – The mockup Orion crew exploration vehicle is on the dock at the Trident Basin at Port Canaveral, Fla., waiting to be tested in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

KSC-2009-2550

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – The mockup Orion crew exploration vehicle is on the dock at the Trident Basin at Port Canaveral, Fla., waiting to be tested in open waters. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-2552

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – The mockup Orion crew exploration vehicle is lowered toward the water at the Trident Basin at Port Canaveral, Fla., for testing. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-2553

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – The mockup Orion crew exploration vehicle is lowered into the water at the Trident Basin at Port Canaveral, Fla., for testing. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-2551

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – The mockup Orion crew exploration vehicle is prepared to be lifted into the water at the Trident Basin at Port Canaveral, Fla., for testing. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Dimitri Gerondidakis

Evaluation of the Effectiveness of the Defense Systems Acquisition Review Council (DSARC). Volume I. Technical Report with Appendices A and B.

DTIC Science & Technology

1983-04-04

Roland 11 Perry Nelson* Hacker Murray 6/79 NAVSTAR 11 Dineen’ Shorey’ Hessler’ Murray 11/79 Copperhead 11 LaBerge * Pinie Wacker Murray 1/SO FYS III... LaBerge ’ Danzig’ Uarshman’ Christie’* 10/80 FVS PR LaBerge ’ Danzig* Bting Cua 6/82 LAMPS III Wade* Leach’ Heth h % Not a principal. "no appointee, actg...to illustrate the situation: FVS Program Review 1/80 LaBerge *Danzig* Harshman*Christie* Program Review 10/80 LaBerge *Danzig* Borsting Murray TRIDENT

Tridentate ligated heteronuclear tin(II) alkoxides for use as base catalysts

DOEpatents

Boyle, Timothy J.

2001-01-01

Tin alkoxide compounds are provided with accessible electrons. The tin alkoxide compound have the general formula (THME).sub.2 Sn.sub.3 (M(L).sub.x).sub.y, where THME is (O--CH.sub.2).sub.3 C(CH.sub.3), M is a metal atom selected from Sn and Ti, L is an organic/inorganic ligand selected from an alkoxide, a phenoxide or an amide, x is selected from 2 and 4 and y is selected from 0 and 1. These compounds have applicability as base catalysts in reactions and in metal-organic chemical vapor depositions processes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chumakov, Yu. M.; Tsapkov, V. I., E-mail: vtsapkov@gmail.com; Antosyak, B. Ya.

Nitrato-4-bromo-2-[(2-hydroxyethylimino)methyl]phenolatoimidazolecopper and nitrato-4-chloro-2-[(2-hydroxyethylimino)methyl]phenolatoimidazolecopper were synthesized and studied by X-ray diffraction. The crystals are isostructural. The coordination polyhedron of the copper atom can be described as a distorted square pyramid whose basal plane is formed by the phenolic and alcoholic oxygen atoms and the nitrogen atom of the monodeprotonated tridentate azomethine molecule and the imidazole nitrogen atom. The apex of the copper polyhedron is occupied by the oxygen atom of the nitrato group. The complexes are linked together by hydrogen bonds with the participation of the nitrato groups to form a three-dimensional framework.

A novel tridentate coordination mode for the carbonatonickel system exhibited in an unusual hexanuclear nickel(II) mu3-carbonato-bridged complex.

PubMed

Anderson, James C; Blake, Alexander J; Moreno, Rafael Bou; Raynel, Guillaume; van Slageren, Joris

2009-11-14

The fixation of CO(2) at ambient temperature has been achieved by the reaction of Ni(cod)(2) and TMEDA in CO(2) saturated THF that yields a novel hexanuclear nickel(II) mu(3)-carbonato bridged complex [Ni(6)(mu(3)-CO(3))(4)(TMEDA)(6)(H(2)O)(12)](OH)(4) in 59% yield. The complex was characterised by MS analysis and the structure corroborated by single-crystal X-ray crystallography. The complex exhibits a rare carbonato binding mode for Ni(II) complexes and moderately strong antiferromagnetic interactions.

A novel tridentate Schiff base dioxo-molybdenum(VI) complex: synthesis, experimental and theoretical studies on its crystal structure, FTIR, UV-visible, ¹H NMR and ¹³C NMR spectra.

PubMed

Saheb, Vahid; Sheikhshoaie, Iran; Stoeckli-Evans, Helen

2012-09-01

A new dioxo-molybdenum(VI) complex [MoO(2)(L)(H(2)O)] has been synthesized, using 5-methoxy 2-[(2-hydroxypropylimino)methyl]phenol as tridentate ONO donor Schiff base ligand (H(2)L) and MoO(2)(acac)(2). The yellow crystals of the compound are used for single-crystal X-ray analysis and measuring Fourier Transform Infrared (FTIR), UV-visible, (1)H NMR and (13)C NMR spectra. Electronic structure calculations at the B3LYP and PW91PW91 levels of theory are performed to optimize the molecular geometry and to calculate the UV-visible, FTIR, (1)H NMR and (13)C NMR spectra of the compound. Vibrational assignments and analysis of the fundamental modes of the compound are performed. Time-dependent density functional theory (TDDFT) method is used to calculate the electronic transitions of the complex. All theoretical methods can well reproduce the structure of the compound. The (1)H NMR shielding tensors computed at the B3LYP/DGDZVP level of theory is in agreement with experimental (1)H NMR spectra. However, the (13)C NMR shielding tensors computed at the B3LYP level, employing a combined basis set of DGDZVP for Mo and 6-31+G(2df,p) for other atoms, are in better agreement with experimental (13)C NMR spectra. The electronic transitions calculated at the B3LYP/DGDZVP level by using TD-DFT method is in accordance with the observed UV-visible spectrum of the compound. Copyright © 2012 Elsevier B.V. All rights reserved.

A Comparison of Gallium and Indium Alkoxide Complexes as Catalysts for Ring-Opening Polymerization of Lactide.

PubMed

Kremer, Alexandre B; Andrews, Ryan J; Milner, Matthew J; Zhang, Xu R; Ebrahimi, Tannaz; Patrick, Brian O; Diaconescu, Paula L; Mehrkhodavandi, Parisa

2017-02-06

The impact of the metal size and Lewis acidity on the polymerization activity of group 13 metal complexes was studied, and it was shown that, within the same ligand family, indium complexes are far more reactive and selective than their gallium analogues. To this end, gallium and aluminum complexes supported by a tridentate diaminophenolate ligand, as well as gallium complexes supported by N,N'-ethylenebis(salicylimine)(salen) ligands, were synthesized and compared to their indium analogues. Using the tridentate ligand set, it was possible to isolate the gallium chloride complexes 3 and (±)-4 and the aluminum analogues 5 and (±)-6. The alkoxygallium complex (±)-2, supported by a salen ligand, was also prepared and characterized and, along with the three-component system GaCl 3 /BnOH/NEt 3 , was tested for the ring-opening polymerization of lactide and ε-caprolactone. The polymerization rates and selectivities of both systems were significantly lower than those for the indium analogues. The reaction of (±)-2 with 1 equiv of lactide forms the first insertion product, which is stable in solution and can be characterized at room temperature. In order to understand the differences of the reactivity within the group 13 metal complexes, a Lewis acidity study using triethylphosphine oxide (the Gutmann-Beckett method) was undertaken for a series of aluminum, gallium, and indium halide complexes; this study shows that indium halide complexes are less Lewis acidic than their aluminum and gallium analogues. Density functional theory calculations show that the Mulliken charges for the indium complexes are higher than those for the gallium analogues. These data suggest that the impact of ligands on the reactivity is more significant than that of the metal Lewis acidity.

{μ-2-[(3-Amino-2,2-dimethyl-prop-yl)imino-meth-yl]-6-meth-oxy-phenolato-1:2κ(5)O(1),O(6):N,N',O(1)}{2-[(3-amino-2,2-dimethyl-prop-yl)imino-meth-yl]-6-meth-oxy-phenolato-1κ(3)N,N',O(1)}-μ-azido-1:2κ(2)N:N-azido-2κN-methanol-2κO-dinickel(II).

PubMed

Ghaemi, Akbar; Rayati, Saeed; Fayyazi, Kazem; Ng, Seik Weng; Tiekink, Edward R T

2012-08-01

Two distinct coordination geometries are found in the binuclear title complex, [Ni(2)(C(13)H(19)N(2)O(2))(2)(N(3))(2)(CH(3)OH)], as one Schiff base ligand is penta-dentate, coordinating via the anti-cipated oxide O, imine N and amine N atoms (as for the second, tridentate, ligand) but the oxide O is bridging and coordination also occurs through the meth-oxy O atom. The Ni(II) atoms are linked by a μ(2)-oxide atom and one end of a μ(2)-azide ligand, forming an Ni(2)ON core. The coordination geometry for the Ni(II) atom coordinated by the tridentate ligand is completed by the meth-oxy O atom derived from the penta-dentate ligand, with the resulting N(3)O(3) donor set defining a fac octa-hedron. The second Ni(II) atom has its cis-octa-hedral N(4)O(2) coordination geometry completed by the imine N and amine N atoms of the penta-dentate Schiff base ligand, a terminally coordinated azide N and a methanol O atom. The arrangement is stabilized by an intra-molecular hydrogen bond between the methanol H and the oxide O atom. Linear supra-molecular chains along the a axis are formed in the crystal packing whereby two amine H atoms from different amine atoms hydrogen bond to the terminal N atom of the monodentate azide ligand.

Unusual saccharin-N,O (carbonyl) coordination in mixed-ligand copper(II) complexes: Synthesis, X-ray crystallography and biological activity

NASA Astrophysics Data System (ADS)

Mokhtaruddin, Nur Shuhada Mohd; Yusof, Enis Nadia Md; Ravoof, Thahira B. S. A.; Tiekink, Edward R. T.; Veerakumarasivam, Abhi; Tahir, Mohamed Ibrahim Mohamed

2017-07-01

Three tridentate Schiff bases containing N and S donor atoms were synthesized via the condensation reaction between S-2-methylbenzyldithiocarbazate with 2-acetyl-4-methylpyridine (S2APH); 4-methyl-3-thiosemicarbazide with 2-acetylpyridine (MT2APH) and 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine (ET2APH). Three new, binuclear and mixed-ligand copper(II) complexes with the general formula, [Cu(sac)(L)]2 (sac = saccharinate anion; L = anion of the Schiff base) were then synthesized, and subsequently characterized by IR and UV/Vis spectroscopy as well as by molar conductivity and magnetic susceptibility measurements. The Schiff bases were also spectroscopically characterized using NMR and MS to further confirm their structures. The spectroscopic data indicated that the Schiff bases behaved as a tridentate NNS donor ligands coordinating via the pyridyl-nitrogen, azomethine-nitrogen and thiolate-sulphur atoms. Magnetic data indicated a square pyramidal environment for the complexes and the conductivity values showed that the complexes were essentially non-electrolytes in DMSO. The X-ray crystallographic analysis of one complex, [Cu(sac)(S2AP)]2 showed that the Cu(II) atom was coordinated to the thiolate-S, azomethine-N and pyridyl-N donors of the S2AP Schiff base and to the saccharinate-N from one anion, as well as to the carbonyl-O atom from a symmetry related saccharinate anion yielding a centrosymmetric binuclear complex with a penta-coordinate, square pyramidal geometry. All the copper(II) saccharinate complexes were found to display strong cytotoxic activity against the MCF-7 and MDA-MB-231 human breast cancer cell lines.

KSC-2009-2554

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – The mockup Orion crew exploration vehicle floats in the water at the Trident Basin at Port Canaveral, Fla. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. The mockup vehicle will undergo testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-2558

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – The mockup Orion crew exploration vehicle is prepared to be lifted into the water at the Trident Basin at Port Canaveral, Fla., for testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

The synthesis of benzimidazoles and quinoxalines from aromatic diamines and alcohols by iridium-catalyzed acceptorless dehydrogenative alkylation.

PubMed

Hille, Toni; Irrgang, Torsten; Kempe, Rhett

2014-05-05

Benzimidazoles and quinoxalines are important N-heteroaromatics with many applications in pharmaceutical and chemical industry. Here, the synthesis of both classes of compounds starting from aromatic diamines and alcohols (benzimidazoles) or diols (quinoxalines) is reported. The reactions proceed through acceptorless dehydrogenative condensation steps. Water and two equivalents of hydrogen are liberated in the course of the reactions. An Ir complex stabilized by the tridentate P^N^P ligand N(2) ,N(6) -bis(di-isopropylphosphino)pyridine-2,6-diamine revealed the highest catalytic activity for both reactions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Colorimetric detection of hydrogen peroxide by dioxido-vanadium(V) complex containing hydrazone ligand: synthesis and crystal structure

NASA Astrophysics Data System (ADS)

Kurbah, Sunshine D.; Syiemlieh, Ibanphylla; Lal, Ram A.

2018-03-01

Dioxido-vanadium(V) complex has been synthesized in good yield, the complex was characterized by IR, UV-visible and 1H NMR spectroscopy. Single crystal X-ray crystallography techniques were used to assign the structure of the complex. Complex crystallized with monoclinic P21/c space group with cell parameters a (Å) = 39.516(5), b (Å) = 6.2571(11), c (Å) = 17.424(2), α (°) = 90, β (°) = 102.668(12) and γ (°) = 90. The hydrazone ligand is coordinate to metal ion in tridentate fashion through -ONO- donor atoms forming a distorted square pyramidal geometry around the metal ion.

Spectral, coordination and thermal properties of 5-arylidene thiobarbituric acids

NASA Astrophysics Data System (ADS)

Masoud, Mamdouh S.; El-Marghany, Adel; Orabi, Adel; Ali, Alaa E.; Sayed, Reham

2013-04-01

Synthesis of 5-arylidine thiobarbituric acids containing different functional groups with variable electronic characters were described and their Co2+, Ni2+ and Cu2+ complexes. The stereochemistry and mode of bonding of 5-(substituted benzylidine)-2-TBA complexes were achieved based on elemental analysis, spectral (UV-VIS, IR, 1H NMR, MS), magnetic susceptibility and conductivity measurements. The ligands were of bidentate and tridentate bonding through S, N and O of pyrimidine nucleolus. All complexes were of octahedral configuration. The thermal data of the complexes pointed to their stability. The mechanism of the thermal decomposition is discussed. The thermodynamic parameters of the dissociation steps were evaluated and discussed.

Bis[2-(2-pyridylmethyl­eneamino)benzene­sulfonato-κ3 N,N′,O]cobalt(II) dihydrate

PubMed Central

Huang, Xue-Ren; Ou-Yang, Miao; Yang, Ge-Ge; Meng, Xiu-Jin; Jiang, Yi-Min

2009-01-01

The title complex, [Co(C12H9N2O3S)2]·2H2O, has site symmetry 2 with the CoII cation located on a twofold rotation axis. Two tridentate 2-(2-pyridylmethyl­eneamino)benzene­sulfonate (paba) ligands chelate to the CoII cation in a distorted octa­hedral geometry. The pyridine and benzene rings in the paba ligand are oriented at a dihedral angle of 42.86 (13)°. Inter­molecular O—H⋯O and C—H⋯O hydrogen bonding is present in the crystal structure. PMID:21578190

Asymmetric rhenium tricarbonyl complexes show superior luminescence properties in live cell imaging.

PubMed

Raszeja, Lukasz J; Siegmund, Daniel; Cordes, Anna L; Güldenhaupt, Jörn; Gerwert, Klaus; Hahn, Stephan; Metzler-Nolte, Nils

2017-01-16

The synthesis and photophysical properties of a novel series of rhenium tricarbonyl complexes based on tridentate phenanthridinyl-containing ligands are described. Photophysical data reveal beneficial luminescence behaviour especially for compounds with an asymmetric ligand set. These advantageous properties are not limited to organic solvents, but indeed also improved in aqueous solutions. The suitability of our new rhenium complexes as potent imaging agents has been confirmed by fluorescence microscopy on living cancer cells, which also confirms superior long-time stability under fluorescence microscopy conditions. Colocalisation studies with commercial organelle stains reveal an accumulation of the complexes in the endoplasmic reticulum for all tested cell lines.

Mount Mageik: A compound stratovolcano in Katmai National Park: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998

USGS Publications Warehouse

Hildreth, Wes; Fierstein, Judy; Lanphere, Marvin A.; Siems, David F.

2000-01-01

Mount Mageik is an ice-clad 2,165-m andesite-dacite stratovolcano in the Katmai volcanic cluster at the head of the Valley of Ten Thousand Smokes. New K-Ar ages indicate that the volcano is as old as 93±8 ka. It has a present-day volume of 20 km3 but an eruptive volume of about 30 km3, implying a longterm average volumetric eruption rate of about 0.33 km3 per 1,000 years. Mount Mageik consists of four overlapping edi- fices, each with its own central summit vent, lava-flow apron, and independent eruptive history. Three of them have small fragmental summit cones with ice-filled craters, but the fourth and highest is topped by a dacite dome. Lava flows predominate on each edifice; many flows have levees and ice-contact features, and many thicken downslope into piedmont lava lobes 50–200 m thick. Active lifetimes of two (or three) of the component edifices may have been brief, like that of their morphological and compositional analog just across Katmai Pass, the Southwest (New) Trident edifice of 1953–74. The North Summit edi- fice of Mageik may have been constructed very late in the Pleistocene and the East Summit edifice (along with nearby Mount Martin) largely or entirely in the Holocene. Substantial Holocene debris avalanches have broken loose from three sites on the south side of Mount Mageik, the youngest during the Novarupta fallout of 6 June 1912. The oldest one was especially mobile, being rich in hydrothermal clay, and is preserved for 16 km downvalley, probably having run out to the sea. Mageik's fumarolically active crater, which now contains a hot acid lake, was never a magmatic vent but was reamed by phreatic explosions through the edge of the dacite summit dome. There is no credible evidence of historical eruptions of Mount Mageik, but the historically persistent fumarolic plumes of Mageik and Martin have animated many spurious eruption reports. Lavas and ejecta of all four component edifices of Mageik are plagioclaserich, pyroxene-dacites and andesites (57–68 weight percent SiO2) that form a calcic, medium-K, typically low-Ti arc suite. The Southwest Summit edifice is larger, longer lived, and compositionally more complex than its companions. Compared to other centers in the Katmai cluster, products of Mount Mageik are readily distinguishable chemically from those of Mount Griggs, Falling Mountain, Mount Cerberus, and all prehistoric components of the Trident group, but some are similar to the products of Mount Martin, Southwest Trident, and Novarupta. The crater lake, vigorous superheated fumaroles, persistent seismicity, steep ice blanket, and numerous Holocene dacites warrant monitoring Mount Mageik as a potential source of explosive eruptions and derivative debris flows.

Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska

USGS Publications Warehouse

Jolly, A.D.; Moran, S.C.; McNutt, S.R.; Stone, D.B.

2007-01-01

The three-dimensional P-wave velocity structure beneath the Katmai group of volcanoes is determined by inversion of more than 10,000 rays from over 1000 earthquakes recorded on a local 18 station short-period network between September 1996 and May 2001. The inversion is well constrained from sea level to about 6??km below sea level and encompasses all of the Katmai volcanoes; Martin, Mageik, Trident, Griggs, Novarupta, Snowy, and Katmai caldera. The inversion reduced the average RMS travel-time error from 0.22??s for locations from the standard one-dimensional model to 0.13??s for the best three-dimensional model. The final model, from the 6th inversion step, reveals a prominent low velocity zone (3.6-5.0??km/s) centered at Katmai Pass and extending from Mageik to Trident volcanoes. The anomaly has values about 20-25% slower than velocities outboard of the region (5.0-6.5??km/s). Moderately low velocities (4.5-6.0??km/s) are observed along the volcanic axis between Martin and Katmai Caldera. Griggs volcano, located about 10??km behind (northwest of) the volcanic axis, has unremarkable velocities (5.0-5.7??km/s) compared to non-volcanic regions. The highest velocities are observed between Snowy and Griggs volcanoes (5.5-6.5??km/s). Relocated hypocenters for the best 3-D model are shifted significantly relative to the standard model with clusters of seismicity at Martin volcano shifting systematically deeper by about 1??km to depths of 0 to 4??km below sea level. Hypocenters for the Katmai Caldera are more tightly clustered, relocating beneath the 1912 scarp walls. The relocated hypocenters allow us to compare spatial frequency-size distributions (b-values) using one-dimensional and three-dimensional models. We find that the distribution of b is significantly changed for Martin volcano, which was characterized by variable values (0.8 < b < 2.0) with standard locations and more uniform values (0.8 < b < 1.2) after relocation. Other seismic clusters at Mageik (1.2 < b < 2.2), Trident (0.5 < b < 1.5) and Katmai Caldera (0.8 < b < 1.8) had stable b-values indicating the robustness of the observations. The strong high b-value region at Mageik volcano is mainly associated with an earthquake swarm in October, 1996 that possibly indicates a shallow intrusion or influx of gas. The new velocity and spatial b-value results, in conjunction with prior gravity (Bouguer anomalies up to - 40??mgal) and interferometry (several cm uplift) data, provide strong evidence in favor of partially molten rock at shallow depths beneath the Mageik-Katmai-Novarupta region. Moderately low velocities beneath Martin and Katmai suggest that old, mostly solidified intrusions exist beneath these volcanoes. Higher relative velocities beneath the Griggs and Snowy vents suggest that no magma is resident in the shallow crust beneath these volcanoes. ?? 2006 Elsevier B.V.

Effects of the HEET garment in the prevention of hypothermia in a porcine model.

PubMed

Johnson, Don; Gegel, Brian; Burgert, James; Duncklee, Geoffrey W; Robison, Ricci R; Lewis, Eric J; Crum, Paul M; Kuhns, William; Moore, Daniel; O'Brien, Scott; Elliott, Joel; Washington, Jason; Boyle, John; Seigler, Dale

2010-11-01

Hypothermia is a common battlefield trauma occurrence. This study compared the effectiveness of the hypothermia, environmental, exposure, and trauma (HEET) garment (Trident Industries, Beaufort, SC) with and without thermal inserts with a control group of two wool blankets in the prevention of hypothermia in a treated hypovolemic porcine model. Five female swine (Sus scrofa-Yorkshire cross) were assigned to each of three groups: HEET with thermal inserts (n=5); HEET without thermal inserts (n=5); or control (n=5). After the animals were anesthetized and stabilized for 30 min, the swine were hemorrhaged to a mean arterial pressure (MAP) of 30 mm Hg, simulating a battlefield injury. Hetastarch 6% (500 mL) was rapidly administered, simulating initial field resuscitation. One hour later, the animals' shed blood was reinfused, simulating transfusion at a field medical facility. The investigators moved the animal into a cooler set at 10°C ± 0.5°C. A pulmonary artery catheter was used to monitor core body temperature over a 6-h period. A repeated measures ANOVA and Tukey's post hoc test were used to analyze the data. There was a significant difference between the groups. At the end of 6h, the mean core temperature for the HEET with inserts group was 32.69°C ± 1.5; the HEET without inserts, 31.02°C ± 1.8; and control, 34.78°C ± 1.2 (P<0.05). While all groups became hypothermic, the wool blanket group was most effective in maintaining body temperature closer to normothermia. The HEET garments with and without heaters are ineffective in preventing hypothermia. Copyright © 2010 Elsevier Inc. All rights reserved.

Solid-state experiments at high pressure and strain rates

NASA Astrophysics Data System (ADS)

Kalantar, D. H.

1999-11-01

We are developing experiments on intense laser facilities to study shock compressed metal foils in the solid state. At high pressure, Rayleigh-Taylor induced perturbation growth can be reduced by the strength of the material. [1] We use this to characterize the strength of the metal foils accelerated at high pressure in the solid state. In our experiments, Al and Cu foils are compressed and accelerated with staged shocks using a temporally shaped x-ray drive that is generated in a Nova laser hohlraum target. [2] The peak pressures exceed 1 Mbar (100 GPa), and strain rates are very high, 10^7-10^9 s-1. The instability growth is observed by x-ray radiography. To probe the state of the material under compression and to demonstrate that it remains solid, we are using the dynamic Bragg diffraction technique. [3] This technique has been demonstrated on the Nova laser [4] using Si crystals shocked to 200-500 kbar. Additionally, we have observed diffraction from Cu crystals that are shocked to 100-200 kbar by direct laser irradiation on the Trident and OMEGA lasers. Compressions of up to a 10in the crystal lattice spacing have been observed. We will present the results of our work to develop these high pressure solid-state hydrodynamics experiments. 1. J. F. Barnes et al, J. Appl. Phys. 45, 727 (1974); A. I. Lebedev et al , Proc. 4th IWPCTM, 29 March-1 April, 1993, p. 81. 2. D. H. Kalantar et al., to appear in Int. J. of Impact Eng. (1999). 3. R. R. Whitlock and J. S. Wark, Phys. Rev. B 52, 8 (1995). 4. D. H. Kalantar et al, Rev. Sci. Instrum. 70, 629 (1999).

Bis(diethylenetriamine-kappa3N)nickel(II) 5-amino-1,3,4-thiadiazole-2-sulfonamidate chloride monohydrate.

PubMed

Liu-Gonzalez, M; Sanz-Ruiz, F; Chufán, E E; Pedregosa, J C; Borras-Tortonda, J

2001-10-01

In the X-ray crystal structure of the title complex, [Ni(C(4)H(13)N(3))(2)](C(2)H(3)N(4)O(2)S(2))Cl.H(2)O, the coordination polyhedron is composed of non-centrosymmetric [Ni(diethylenetriamine)(2)](2+) cations in which the triamine ligands coordinate to the metal centre as tridentate ligands in a facial position. The Ni(II) ions are linked to six N atoms in an octahedral arrangement, slightly compressed in one extreme. The sulfonamide behaves as a counter-ion instead of as a ligand. Important information about the deprotonated sulfonamide group conformation has been obtained.

KSC-2009-2561

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – Flotation devices are attached to the top of the mockup Orion crew exploration vehicle before the testing in the open water at the Trident Basin at Port Canaveral, Fla. The mockup vehicle will undergo testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

KSC-2009-2566

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – The mockup Orion crew exploration vehicle floats in the water at the Trident Basin at Port Canaveral, Fla. On top of Orion are additional flotation devices. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. The mockup vehicle is undergoing testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

KSC-2009-2555

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – Members of the 920th Rescue Wing get ready to release a flotation collar around the mockup Orion crew exploration vehicle at the Trident Basin at Port Canaveral, Fla. On top of Orion are additional flotation devices. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-2560

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – Members of the 920th Rescue Wing help prepare the mockup Orion crew exploration vehicle for testing in the open water at the Trident Basin at Port Canaveral, Fla. The mockup vehicle will undergo testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

Recovery of Uranium from Seawater: Preparation and Development of Polymer-Supported Extractants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spiro, Alexandratos

2013-12-01

A new series of polymer-supported extractants is proposed for the removal and recovery of uranium from seawater. The objective is to produce polymers with improved stability, loading capacity, and sorption kinetics compared to what is found with amidoximes. The target ligands are diphosphonates and aminomethyldiphosphonates. Small molecule analogues, especially of aminomethyldiphos-phonates, have exceptionally high stability constants for the uranyl ion. The polymeric diphosphonates will have high affinities due to their ability to form six-membered rings with the uranyl ion while the aminomethyldiphosphonates may have yet higher affinities due to possible tridentate coordination and their greater acidity. A representative set ofmore » the polymers to be prepared are indicated.« less

Hydrogenation of carboxylic acids with a homogeneous cobalt catalyst.

PubMed

Korstanje, Ties J; van der Vlugt, Jarl Ivar; Elsevier, Cornelis J; de Bruin, Bas

2015-10-16

The reduction of esters and carboxylic acids to alcohols is a highly relevant conversion for the pharmaceutical and fine-chemical industries and for biomass conversion. It is commonly performed using stoichiometric reagents, and the catalytic hydrogenation of the acids previously required precious metals. Here we report the homogeneously catalyzed hydrogenation of carboxylic acids to alcohols using earth-abundant cobalt. This system, which pairs Co(BF4)2·6H2O with a tridentate phosphine ligand, can reduce a wide range of esters and carboxylic acids under relatively mild conditions (100°C, 80 bar H2) and reaches turnover numbers of up to 8000. Copyright © 2015, American Association for the Advancement of Science.

Synthesis and characterization of copper complexes of Schiff base derived from isatin and salicylic hydrazide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lekshmy, R. K., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com; Thara, G. S., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com

A series of novel metal complexes of Schiff base have been prepared by the interaction of Cu(II) with isatin salicylic hydrazide. All the new compounds were characterized by elemental analysis, conductance measurement, magnetic moment determination, IR, UV, NMR, Mass and EPR spectral studies, thermal studies and microbial activities. The results indicate that the ligand acts as a tridentate chelating ligand coordinating through nitrogen and oxygen atoms. The ligand and complexes show inactive against Escherichia coli and active against Staphylococcus aureus and B.substilis. By analyzing the results of spectral, thermal and elemental analysis square planar geometry is proposed for all themore » complexes.« less

Structural and Biological Behaviour of Co(II), Cu(II) and Ni(II) Metal Complexes of Some Amino Acid Derived Schiff-Bases

PubMed Central

Chohan, Zahid H.; Praveen, M.; Ghaffar, A.

1997-01-01

Biologically active tridentate amino acid (Alanine, Glycine & Tyrosine) derived Schiff-bases and their Co(II), Cu(II) & Ni(II) complexes have been synthesised and characterised on the basis of their conductance and magnetic measurements, elemental analysis and 13C-NMR, 1H-NMR, IR and electronic spectral data. These Schiff-bases and their complexes have been evaluated for their antibacterial activity against bacterial species such as Staphylococcus aureus, Escherichia coli, Klebsiella pneumonae, Proteus vulgarus and Pseudomonas aeruginosa and this activity data show the metal complexes to be more antibacterial than the Schiff-bases against one or more bacterial species. PMID:18475798

Synthesis, Characterization, Crystal Structure, and Biological Studies of a Cadmium(II) Complex with a Tridentate Ligand 4′-Chloro-2,2′:6′,2′′-Terpyridine

PubMed Central

Saghatforoush, L. A.; Valencia, L.; Chalabian, F.; Ghammamy, Sh.

2011-01-01

A new Cd(II) complex with the ligand 4′-chloro-2,2′6′,2′′-terpyridine (Cltpy), [Cd(Cltpy)(I)2], has been synthesized and characterized by CHN elemental analysis, 1H-NMR, 13C-NMR, and IR spectroscopy and structurally analyzed by X-ray single-crystal diffraction. The single-crystal X-ray analyses show that the coordination number in complex is five with three terpyridine (Cltpy) N-donor atoms and two iodine atoms. The antibacterial activities of Cltpy and its Cd(II) complex are tested against different bacteria. PMID:21738495

Geologic Map of the Katmai Volcanic Cluster, Katmai National Park, Alaska

USGS Publications Warehouse

Hildreth, Wes; Fierstein, Judy

2002-01-01

This digital publication contains all the geologic map information used to publish U.S. Geological Survey Geologic Investigations Map Series I-2778 (Hildreth and Fierstein, 2003). This is a geologic map of the Katmai volcanic cluster on the Alaska Peninsula (including Mount Katmai, Trident Volcano, Mount Mageik, Mount Martin, Mount Griggs, Snowy Mountain, Alagogshak volcano, and Novarupta volcano), and shows the distribution of ejecta from the great eruption of June, 1912 at Novarupta. Widely scattered erosional remnants of volcanic rocks, unrelated to but in the vicinity of the Katmai cluster, are also mapped. Distribution of glacial deposits, large landslides, debris avalanches, and surficial deposits are a snapshot of an ever-changing landscape.

The bulk isotopic composition of hydrocarbons in subaerial volcanic-hydrothermal emissions from different tectonic settings

NASA Astrophysics Data System (ADS)

Fiebig, J.; Tassi, F.; Vaselli, O.; Viveiros, M. F.; Silva, C.; Lopez, T. M.; D'Alessandro, W.; Stefansson, A.

2015-12-01

Assuming that methane and its higher chain homologues derive from a common source, carbon isotope patterns have been applied as a criterion to identify occurrences of abiogenic hydrocarbons. Based on these, it has been postulated that abiogenic hydrocarbon production occurs within several (ultra)mafic environments. More evolved volcanic-hydrothermal systems may also provide all the prerequisites necessary for abiogenic hydrocarbon production, such as availability of inorganic CO2, hydrogen and heat. We have investigated the chemical and isotopic composition of n-alkanes contained within subaerial hydrothermal discharges emitted from a range of hot spot, subduction and rift-related volcanoes to determine the origin of hydrocarbons in these systems. Amongst these are Nisyros (Greece), Vesuvio, Campi Flegrei, Ischia, Pantelleria and Vulcano (all Italy), Mt. Mageik and Trident (USA), Copahue (Argentina), Teide (Spain), Furnas and Fogo (Portugal). The carbon isotopic composition of methane emitted from these sites varies from -65 to -8‰ , whereas δ13C of ethane and propane exhibit a much narrower variation from -17‰ to -31‰. Methane that occurs most enriched in 13C is also characterized by relatively positive δD values ranging up to -80‰. Carbon isotope reversals between methane and ethane are only observed for locations exhibiting δ13C-CH4 values > -20‰, such as Teide, Pantelleria, Trident and Furnas. At Furnas, δ13C-CH4 varies by 50‰ within a relatively short distance of <50m between two vents, whereas δ13C-C2H6 varies by less than 2‰ only. For some of the investigated locations apparent carbon isotopic temperatures between methane and CO2 are in agreement with those derived from gas concentration geothermometers. At these locations methane, however seems to be in disequilibrium with ethane and propane. These findings imply that methane on the one hand and the C2+ hydrocarbons on the other hand often might derive from distinct sources.

Intense laser-driven ion beams in the relativistic-transparency regime: acceleration, control and applications

NASA Astrophysics Data System (ADS)

Fernandez, Juan C.

2016-10-01

Laser-plasma interactions in the novel regime of relativistically-induced transparency have been harnessed to generate efficiently intense ion beams with average energies exceeding 10 MeV/nucleon (>100 MeV for protons) at ``table-top'' scales. We have discovered and utilized a self-organizing scheme that exploits persisting self-generated plasma electric ( 0.1 TV/m) and magnetic ( 104 Tesla) fields to reduce the ion-energy (Ei) spread after the laser exits the plasma, thus separating acceleration from spread reduction. In this way we routinely generate aluminum and carbon beams with narrow spectral peaks at Ei up to 310 MeV and 220 MeV, respectively, with high efficiency ( 5%). The experimental demonstration has been done at the LANL Trident laser with 0.12 PW, high-contrast, 0.65 ps Gaussian laser pulses irradiating planar foils up to 250 nm thick. In this regime, Ei scales empirically with laser intensity (I) as I 1 / 2. Our progress is enabled by high-fidelity, massive computer simulations of the experiments. This work advances next-generation compact accelerators suitable for new applications. E . g ., a carbon beam with Ei 400 MeV and 10% energy spread is suitable for fast ignition (FI) of compressed DT. The observed scaling suggests that is feasible with existing target fabrication and PW-laser technologies, using a sub-ps laser pulse with I 2.5 ×1021 W/cm2. These beams have been used on Trident to generate warm-dense matter at solid-densities, enabling us to investigate its equation of state and mixing of heterogeneous interfaces purely by plasma effects distinct from hydrodynamics. They also drive an intense neutron-beam source with great promise for important applications such as active interrogation of shielded nuclear materials. Considerations on controlling ion-beam divergence for their increased utility are discussed. Funded by the LANL LDRD program.

Metal cation dependence of interactions with amino acids: bond dissociation energies of Rb(+) and Cs(+) to the acidic amino acids and their amide derivatives.

PubMed

Armentrout, P B; Yang, Bo; Rodgers, M T

2014-04-24

Metal cation-amino acid interactions are key components controlling the secondary structure and biological function of proteins, enzymes, and macromolecular complexes comprising these species. Determination of pairwise interactions of alkali metal cations with amino acids provides a thermodynamic vocabulary that begins to quantify these fundamental processes. In the present work, we expand a systematic study of such interactions by examining rubidium and cesium cations binding with the acidic amino acids (AA), aspartic acid (Asp) and glutamic acid (Glu), and their amide derivatives, asparagine (Asn) and glutamine (Gln). These eight complexes are formed using electrospray ionization and their bond dissociation energies (BDEs) are determined experimentally using threshold collision-induced dissociation with xenon in a guided ion beam tandem mass spectrometer. Analyses of the energy-dependent cross sections include consideration of unimolecular decay rates, internal energy of the reactant ions, and multiple ion-neutral collisions. Quantum chemical calculations are conducted at the B3LYP, MP2(full), and M06 levels of theory using def2-TZVPPD basis sets, with results showing reasonable agreement with experiment. At 0 and 298 K, most levels of theory predict that the ground-state conformers for M(+)(Asp) and M(+)(Asn) involve tridentate binding of the metal cation to the backbone carbonyl, amino, and side-chain carbonyl groups, although tridentate binding to the carboxylic acid group and side-chain carbonyl is competitive for M(+)(Asn). For the two longer side-chain amino acids, Glu and Gln, multiple structures are competitive. A comparison of these results to those for the smaller alkali cations, Na(+) and K(+), provides insight into the trends in binding energies associated with the molecular polarizability and dipole moment of the side chain. For all four metal cations, the BDEs are inversely correlated with the size of the metal cation and follow the order Asp < Glu < Asn < Gln.

KSC-2009-2565

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – Members of the 920th Rescue Wing secure a flotation collar around the mockup Orion crew exploration vehicle at the Trident Basin at Port Canaveral, Fla. On top of Orion are additional flotation devices. The mockup vehicle will undergo testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

KSC-2009-2563

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – Members of the 920th Rescue Wing release a flotation collar around the mockup Orion crew exploration vehicle at the Trident Basin at Port Canaveral, Fla. On top of Orion are additional flotation devices. The mockup vehicle will undergo testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

KSC-2009-2562

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – Members of the 920th Rescue Wing make their way toward the mockup Orion crew exploration vehicle floating in the open water of the Trident Basin at Port Canaveral, Fla. They will place a flotation collar around the mockup vehicle. The mockup vehicle will undergo testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

KSC-2009-2564

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – Members of the 920th Rescue Wing release a flotation collar around the mockup Orion crew exploration vehicle at the Trident Basin at Port Canaveral, Fla. On top of Orion are additional flotation devices. The mockup vehicle will undergo testing in open water. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Kim Shiflett

Re and 99mTc Tricarbonyl Probes for Target-Specific Detection of Melanoma and Sentinel Lymph Node

NASA Astrophysics Data System (ADS)

Morais, Mauricio da Silva

The work described in this thesis aimed at the development of M(I) (M = 99mTc, Re) specific probes for the detection of malignant melanoma and sentinel lymph node (SLN) through the in vivo targeting of membrane receptors. In the former case we have designed M(CO)3-complexes stabilized by tridentate chelators containing a pyrazolyl-diamine chelating unit (N,N,N donor atom set) and pendant alpha-melanocyte-stimulating hormone (alpha-MSH) derivatives for targeting the melanocortin receptor 1 (MC1R), which is overexpressed in melanotic and amelanotic human melanoma cells. (Abstract shortened by ProQuest.). None None None None None None None None None None None None None None None None None

A peroxynitrite complex of copper: formation from a copper-nitrosyl complex, transformation to nitrite and exogenous phenol oxidative coupling or nitration.

PubMed

Park, Ga Young; Deepalatha, Subramanian; Puiu, Simona C; Lee, Dong-Heon; Mondal, Biplab; Narducci Sarjeant, Amy A; del Rio, Diego; Pau, Monita Y M; Solomon, Edward I; Karlin, Kenneth D

2009-11-01

Reaction of nitrogen monoxide with a copper(I) complex possessing a tridentate alkylamine ligand gives a Cu(I)-(*NO) adduct, which when exposed to dioxygen generates a peroxynitrite (O=NOO(-))-Cu(II) species. This undergoes thermal transformation to produce a copper(II) nitrito (NO(2) (-)) complex and 0.5 mol equiv O(2). In the presence of a substituted phenol, the peroxynitrite complex effects oxidative coupling, whereas addition of chloride ion to dissociate the peroxynitrite moiety instead leads to phenol ortho nitration. Discussions include the structures (including electronic description) of the copper-nitrosyl and copper-peroxynitrite complexes and the formation of the latter, based on density functional theory calculations and accompanying spectroscopic data.

A comparison of gas geochemistry of fumaroles in the 1912 ash-flow sheet and on active stratovolcanoes, Katmai National Park, Alaska

USGS Publications Warehouse

Sheppard, D.S.; Janik, C.J.; Keith, T.E.C.

1992-01-01

Fumarolic gas samples collected in 1978 and 1979 from the stratovolcanoes Mount Griggs, Mount Mageik, and the 1953-68 SW Trident cone in Katmai National Park, Alaska, have been analysed and the results presented here. Comparison with recalculated analyses of samples collected from the Valley of Ten Thousand Smokes (VTTS) in 1917 and 1919 demonstrates differences between gases from the short-lived VTTS fumaroles, which were not directly magma related, and the fumaroles on the volcanic peaks. Fumarolic gases of Mount Griggs have an elevated total He content, suggesting a more direct deep crustal or mantle source for these gases than those from the other volcanoes. ?? 1992.

Preliminary volcano-hazard assessment for the Katmai volcanic cluster, Alaska

USGS Publications Warehouse

Fierstein, Judy; Hildreth, Wes

2000-01-01

The world’s largest volcanic eruption of the 20th century broke out at Novarupta (fig. 1) in June 1912, filling with hot ash what came to be called the Valley of Ten Thousand Smokes and spreading downwind more fallout than all other historical Alaskan eruptions combined. Although almost all the magma vented at Novarupta, most of it had been stored beneath Mount Katmai 10 km away, which collapsed during the eruption. Airborne ash from the 3-day event blanketed all of southern Alaska, and its gritty fallout was reported as far away as Dawson, Ketchikan, and Puget Sound (fig. 21). Volcanic dust and sulfurous aerosol were detected within days over Wisconsin and Virginia; within 2 weeks over California, Europe, and North Africa; and in latter-day ice cores recently drilled on the Greenland ice cap. There were no aircraft in Alaska in 1912—fortunately! Corrosive acid aerosols damage aircraft, and ingestion of volcanic ash can cause abrupt jet-engine failure. Today, more than 200 flights a day transport 20,000 people and a fortune in cargo within range of dozens of restless volcanoes in the North Pacific. Air routes from the Far East to Europe and North America pass over and near Alaska, many flights refueling in Anchorage. Had this been so in 1912, every airport from Dillingham to Dawson and from Fairbanks to Seattle would have been enveloped in ash, leaving pilots no safe option but to turn back or find refuge at an Aleutian airstrip west of the ash cloud. Downwind dust and aerosol could have disrupted air traffic anywhere within a broad swath across Canada and the Midwest, perhaps even to the Atlantic coast. The great eruption of 1912 focused scientific attention on Novarupta, and subsequent research there has taught us much about the processes and hazards associated with such large explosive events (Fierstein and Hildreth, 1992). Moreover, work in the last decade has identified no fewer than 20 discrete volcanic vents within 15 km of Novarupta (Hildreth and others, 1999, 2000, 2001; Hildreth and Fierstein, 2000), only half of which had been named previously—the four stratovolcanoes Mounts Katmai, Mageik, Martin, and Griggs; the cone cluster called Trident Volcano; Snowy Mountain; and the three lava domes Novarupta, Mount Cerberus, and Falling Mountain. The most recent eruptions were from Trident Volcano (1953–74), but there have been at least eight other, probably larger, explosive events from the volcanoes of this area in the past 10,000 years. This report summarizes what has been learned about the volcanic histories and styles of eruption of all these volcanoes. Many large earthquakes occurred before and during the 1912 eruption, and the cluster of Katmai volcanoes remains seismically active. Because we expect an increase in seismicity before eruptions, seismic monitoring efforts to detect volcanic unrest and procedures for eruption notification and dissemination of information are included in this report. Most at risk from future eruptions of the Katmai volcanic cluster are (1) air-traffic corridors of the North Pacific, including those approaching Anchorage, one of the Pacific’s busiest international airports, (2) several regional airports and military air bases, (3) fisheries and navigation on the Naknek Lake system and Shelikof Strait, (4) pristine wildlife habitat, particularly that of the Alaskan brown bear, and (5) tourist facilities in and near Katmai National Park.

Uranium Hydridoborates: Synthesis, Magnetism, and X-ray/Neutron Diffraction Structures.

PubMed

Braunschweig, H; Gackstatter, A; Kupfer, T; Radacki, K; Franke, S; Meyer, K; Fucke, K; Lemée-Cailleau, M-H

2015-08-17

While uranium hydridoborate complexes containing the [BH4](-) moiety have been well-known in the literature for many years, species with functionalized borate centers remained considerably rare. We were now able to prepare several uranium hydridoborates (1-4) with amino-substituted borate moieties with high selectivity by smooth reaction of [Cp*2UMe2] (Cp* = C5Me5) and [Cp'2UMe2] (Cp' = 1,2,4-tBu3C5H2) with the aminoborane H2BN(SiMe3)2. A combination of nuclear magnetic resonance spectroscopy, deuteration experiments, magnetic SQUID measurements, and X-ray/neutron diffraction studies was used to verify the anticipated molecular structures and oxidation states of 1-4 and helped to establish a linear tridentate coordination mode of the borate anions.

Nuclear Emulsion Analysis Methods of Locating Neutrino Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erickson, Carolyn Lee

2006-12-01

The Fermilab experiment 872 (DONUT) was the first to directly observe tau neutrinos in the charged current interactionV more » $$\\tau$$+N →$$\\tau$$ +X. The observation was made using a hybrid emulsion-spectrometer detector to identify the signature kink or trident decay of the tau particle. Although nuclear emulsion has the benefit of sub-micron resolution, its use incorporates difficulties such as significant distortions and a high density of data resulting from its continuously active state. Finding events and achieving sub-micron resolution in emulsion requires a multi-pronged strategy of tracking and vertex location to deal with these inherent difficulties. By applying the methods developed in this thesis, event location efficiency can be improved from a value of 58% to 87%.« less

KSC-2009-2556

NASA Image and Video Library

2009-04-08

CAPE CANAVERAL, Fla. – Members of the 920th Rescue Wing release a flotation collar around the mockup Orion crew exploration vehicle at the Trident Basin at Port Canaveral, Fla. On top of Orion are additional flotation devices. The goal of the operation, dubbed the Post-landing Orion Recovery Test, or PORT, is to determine what kind of motion astronauts can expect after landing, as well as outside conditions for recovery teams. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion is targeted to begin carrying humans to the International Space Station in 2015 and to the moon by 2020. Orion, along with the Ares I and V rockets and the Altair lunar lander, are part of the Constellation Program. Photo credit: NASA/Dimitri Gerondidakis

Lanthanide-binding peptides with two pendant aminodiacetate arms: impact of the sequence on chelation.

PubMed

Niedźwiecka, Agnieszka; Cisnetti, Federico; Lebrun, Colette; Gateau, Christelle; Delangle, Pascale

2012-03-21

Lanthanide complexes with a series of hexapeptides-incorporating two unnatural chelating amino acids with aminodiacetate groups, Ada(1) and Ada(2)-have been examined in terms of their speciation, structure, stability and luminescence properties. Whereas Ada(2) acts as a tridentate donor in all cases, Ada(1) may act as a tetradentate donor thanks to the coordination of the amide carbonyl function assisted by the formation of a six-membered chelate ring. The position of the Ada(1) residue in the sequence is demonstrated to be critical for the lanthanide complex speciation and structure. Ada(1) promotes the coordination of the backbone amide function to afford a highly dehydrated Ln complex and an S-shape structure of the peptide backbone, only when found in position 2.

Mapping of a novel QTL for resistance to cereal cyst nematode in wheat.

PubMed

Williams, K J; Willsmore, K L; Olson, S; Matic, M; Kuchel, H

2006-05-01

Cereal cyst nematode (CCN; Heterodera avenae Woll.) is a root pathogen of cereals that can cause severe yield losses in intolerant wheat cultivars. Loci for resistance to CCN, measured by a seedling bioassay, were identified by creating a genetic map based on a Trident/Molineux doubled haploid population of 182 lines. A novel locus accounting for up to 14% of the resistance to CCN was mapped to chromosome 1B of Molineux by association with microsatellite marker loci Xwmc719 and Xgwm140. This locus acts additively with the previously identified CCN resistance loci identified on chromosomes 6B (Cre8) and 2A (Cre5 on the VPM1 segment) in this population to explain 44% of the genetic variance for this major wheat pathogen.

Aging results for PRD 49 III/epoxy and Kevlar 49/epoxy composite pressure vessels

NASA Technical Reports Server (NTRS)

Hamstad, M. A.

1983-01-01

Kevlar 49/epoxy composite is growing in use as a structural material because of its high strength-to-weight ratio. Currently, it is used for the Trident rocket motor case and for various pressure vessels on the Space Shuttle. In 1979, the initial results for aging of filament-wound cylindrical pressure vessels which were manufactured with preproduction Kevlar 49 (Hamstad, 1979) were published. This preproduction fiber was called PRD 49 III. This report updates the continuing study to 10-year data and also presents 7.5-year data for spherical pressure vessels wound with production Kevlar 49. For completeness, this report will again describe the specimens of the original study with PRD 49 as well as specimens for the new study with Kevlar 49.

New perspectives on the eruption of 1912 in the valley of ten thousand smokes, Katmai National Park, Alaska

USGS Publications Warehouse

Hildreth, W.

1987-01-01

New data extend our understanding of the 1912 eruption, its backfilled vent complex at Novarupta, and magma-storage systems beneath adjacent stratovolcanoes. Initial Plinian rhyolite fallout is confined to a narrow downwind sector, and its maximum thickness may occur as far as 13 km from source. In contrast, the partly contemporaneous rhyolite-rich ash flows underwent relatively low-energy emplacement, their generation evidently being decoupled from the high column. Flow veneers 1-13 m thick on near-vent ridge crests exhibit a general rhyolite-to-andesite sequence like that of the much thicker valley-confined ignimbrite into which they merge downslope. Lithics in both the initial Plinian and the ignimbrite are predominantly fragments of the Jurassic Naknek Formation, which extends from the surface to a depth of ca. 1500 m. Absence of lithics from the underlying sedimentary section limits to 100 m thick near source and 10 m thick 3 km away, which dip back into an inner vent <0.5 km wide, nested inside the earlier vent funnel of the ignimbrite. The dacite fallout is poor in Naknek lithics but contains abundant fragments of vitrophyre, most of which was vent-filling, densely welded tuff reejected during later phases of the 3-day eruption. Adjacent to the inner vent, a 225-m-high asymmetrical accumulation of coarse near-vent ejecta is stratigraphically continuous with the regional dacite fallout. Distensional faulting of its crest may reflect spreading related to compaction and welding. Nearby andesite-dacite stratovolcanoes, i.e., Martin, Mageik, Trident, and Katmai, display at least 12 vents that define a linear volcanic front trending N65??E. The 1912 vent and adjacent dacite domes are disposed parallel to the front and ca. 4 km behind it. Mount Griggs, 10 km behind the front, is more potassic than other centers, taps isotopically more depleted source materials, and reflects a wholly independent magmatic plumbing system. Geochemical differences among the stratovolcanoes, characteristically small eruptive volumes ( < 0.1 to 0.4 km3), and the dominance of andesite and low-SiO2 dacite suggest complex crustal reservoirs, not large integrated magma chambers. Linear fractures just outside the 1912 vent strike nearly normal to the volcanic front and may reflect dike transport of magma previously stored beneath Trident 3-5 km away. Caldera collapse at Mount Katmai may have taken place in response to hydraulic transfer of Katmai magma toward Novarupta via reservoir components beneath Trident. The voluminous 1912 eruption (12-15 km3 DRE) was also unusual in producing high-silica rhyolite (6-9 km3 DRE), a composition rare in this arc and on volcanic fronts in general. Isotopic data indicate that rhyolite genesis involved little assimilation of sedimentary rocks, pre-Tertiary plutonic rocks, or hydrothermally altered rocks of any age. Trace-element data suggest nonetheless that the rhyolite contains a nontrivial crustal contribution, most likely partial melts of Late Cenozoic arc-intrusive rocks. Because the three compositions (77%, 66-64.5%, and 61.5-58.5% SiO2) that intermingled in 1912 vented both concurrently and repeatedly (after eruptive pauses hours in duration), the compositional gaps between them must have been intrinsic to the reservoir, not merely effects of withdrawal dynamics. ?? 1987 Springer-Verlag.

Aerosol-Assisted Solid Debris Collection for the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, S L; Shaughnessy, D A; Moody, K J

2010-05-21

The National Ignition Facility (NIF) has been completed and has made its first shots on-target. While upcoming experiments will be focused on achieving ignition, a variety of subsequent experiments are planned for the facility, including measurement of cross sections, astrophysical measurements, and investigation of hydrodynamic instability in the target capsule. In order to successfully execute several of these planned experiments, the ability to collect solid debris following a NIF capsule shot will be required. The ability to collect and analyze solid debris generated in a shot at the National Ignition Facility (NIF) will greatly expand the number of nuclear reactionsmore » studied for diagnostic purposes. Currently, reactions are limited to only those producing noble gases for cryogenic collection and counting with the Radchem Apparatus for Gas Sampling (RAGS). The radchem solid collection diagnostic has already been identified by NIF to be valuable for the determination and understanding of mix generated in the target capsule's ablation. LLNL is currently developing this solid debris collection capability at NIF, and is in the stage of testing credible designs. Some of these designs explore the use of x-ray generated aerosols to assist in collection of solid debris. However, the variety of harsh experimental conditions this solid collection device will encounter in NIF are challenging to replicate. Experiments performed by Gary Grim et al. at Sandia National Laboratory's RHEPP1 facility have shown that ablation causes a cloud of material removed from an exposed surface to move normal to and away from the surface. This ablation is certain to be a concern in the NIF target chamber from the prompt x-rays, gamma rays, etc. generated in the shot. The cloud of ablated material could interfere with the collection of the desired reaction debris by slowing down the debris so that the kinetic energy is too low to allow implantation, or by stopping the debris from reaching the collection device entirely. Our goal is to use this primary ablation wave to our advantage, by the creation of ionized alkali metal halide salt aerosols. This technique is similar to that used by many particle accelerator groups for gas-jet transport. Ideally the salt would be ablated from a substrate, encounter the reaction debris, agglomerate, and be collected for further study. We have done studies at laser and pulsed-power facilities (Titan laser at LLNL, Trident laser at LANL, Zebra z-pinch at Nevada Terawatt Facility) evaluating the hardiness of materials for placement in the NIF target chamber, as well as testing aerosol generation by the incident x-rays generated in device shots. To test this method's potential success in the NIF environment, we have tested KCl, KI, RbI, and CsI films of 1 and 2 um linear thickness on aluminum and silicon wafer substrates in these aforementioned facilities, at varied distances. These salts do ablate in the presence of sufficient x-ray fluence. Further analysis to quantify the final ablation depth as a function of x-ray fluence is ongoing. Half of each sample was masked with a thick tungsten foil for photon opacity. KCl was the most difficult salt to ablate, from comparing the tungsten-masked side of the samples to the unmasked side of the samples. This is likely due to KCl's absorbance peak being at lower wavelengths than that of KI, {approx}160 nm vs. {approx}220 nm, respectively. Samples with and without collimation were tested to identify if any condensation of these ablated salts occurred after ablation. Visual inspection of the silicon wafer witness plates placed parallel to the direction of the incident photons showed that a vapor was deposited on the wafers next to the collimators. Further analysis with EDS in the case of the collimated samples conclusively identified the vapor as CsI. We also intend to examine samples of bare substrate exposed to the same experimental conditions for post-shot change via SEM images, optical microscopy, and atomic force microscopy (AFM). Furthermore, tests with separated isotopes may be done to reduce background contamination. When sample optimization is complete, we plan to develop a 'catcher' device for these desorbed aerosols. Current ideas include biased grids to either attract the ionized particles to the grid, or repel them towards a collection device.« less

Oxidative condensation reactions of (diethylenetriamine)cobalt(III) complexes with substituted bis(pyridin-2-yl)methane ligands

NASA Astrophysics Data System (ADS)

Zhou, Xiangting; Hockless, David C. R.; Willis, Anthony C.; Jackson, W. Gregory

2005-04-01

The synthesis and characterisation of Co(III) complexes derived from a condensation reaction with a central or terminal nitrogen of a dien ligand and the α-carbon of a range of substituted bis(pyridin-2-yl)methane ligands are described. Aerial oxidation of bpm {bis(pyridin-2-yl)methane with Co(II)/dien or direct reaction with Co(dien)Cl 3 provided in low yield a single C-N condensation product 1 (at the primary terminal NH 2) after the pyridyl -CH 2- is formally oxidised to -CH +-. The methyl substituted ligand bpe {1,1-bis(pyridin-2-yl)ethane} behaves likewise, except both terminal (prim) and central (sec) amines condense to yield isomeric products 2 and 3. Two of these three materials have been characterised by single crystal X-ray crystallography. The corresponding reactions for the bis(pyridyl) ligand bpk {bis(pyridin-2-yl)ketone} provided C-N condensation products without the requirement for oxidation at the α-C center; two carbinolamine complexes in different geometrical configurations resulted, mer-anti-[Co(dienbpc)Cl]ZnCl 4, 5, and unsym- fac-[Co(dienbpc)Cl]ZnCl 4, 6, {dienbpc=[2-(2-aminoethylamino)-ethylamino]-di-pyridin-2-yl-methanol}. In addition, a novel complex, [Co(bpk)(bpd-OH)Cl]ZnCl 4, 4, in which one bidentate N, N-bonded bpk ligand and one tridentate N, O, N-bonded bpd (the diol from bpk+OH -) were coordinated, was obtained via the Co(II)/O 2 synthetic route. When the bpc ligand (bpc=bis(pyridin-2-yl)methanol) was employed directly as a reagent along with dien, no condensation reactions were observed, but rather a single isomeric complex [Co(dien)(bpc)]Cl.ZnCl 4, 7, in which the ligand bpc acted as a N,N,O-bonded tridentate ligand rather than as a N,N-bidentate ligand was isolated. 13C, 1D and 2D 1H NMR studies are reported for all the complexes; they establish the structures unambiguously.

Laser-plasmas in the relativistic-transparency regime: Science and applications

NASA Astrophysics Data System (ADS)

Fernández, Juan C.; Cort Gautier, D.; Huang, Chengkung; Palaniyappan, Sasikumar; Albright, Brian J.; Bang, Woosuk; Dyer, Gilliss; Favalli, Andrea; Hunter, James F.; Mendez, Jacob; Roth, Markus; Swinhoe, Martyn; Bradley, Paul A.; Deppert, Oliver; Espy, Michelle; Falk, Katerina; Guler, Nevzat; Hamilton, Christopher; Hegelich, Bjorn Manuel; Henzlova, Daniela; Ianakiev, Kiril D.; Iliev, Metodi; Johnson, Randall P.; Kleinschmidt, Annika; Losko, Adrian S.; McCary, Edward; Mocko, Michal; Nelson, Ronald O.; Roycroft, Rebecca; Santiago Cordoba, Miguel A.; Schanz, Victor A.; Schaumann, Gabriel; Schmidt, Derek W.; Sefkow, Adam; Shimada, Tsutomu; Taddeucci, Terry N.; Tebartz, Alexandra; Vogel, Sven C.; Vold, Erik; Wurden, Glen A.; Yin, Lin

2017-05-01

Laser-plasma interactions in the novel regime of relativistically induced transparency (RIT) have been harnessed to generate intense ion beams efficiently with average energies exceeding 10 MeV/nucleon (>100 MeV for protons) at "table-top" scales in experiments at the LANL Trident Laser. By further optimization of the laser and target, the RIT regime has been extended into a self-organized plasma mode. This mode yields an ion beam with much narrower energy spread while maintaining high ion energy and conversion efficiency. This mode involves self-generation of persistent high magnetic fields (˜104 T, according to particle-in-cell simulations of the experiments) at the rear-side of the plasma. These magnetic fields trap the laser-heated multi-MeV electrons, which generate a high localized electrostatic field (˜0.1 T V/m). After the laser exits the plasma, this electric field acts on a highly structured ion-beam distribution in phase space to reduce the energy spread, thus separating acceleration and energy-spread reduction. Thus, ion beams with narrow energy peaks at up to 18 MeV/nucleon are generated reproducibly with high efficiency (≈5%). The experimental demonstration has been done with 0.12 PW, high-contrast, 0.6 ps Gaussian 1.053 μm laser pulses irradiating planar foils up to 250 nm thick at 2-8 × 1020 W/cm2. These ion beams with co-propagating electrons have been used on Trident for uniform volumetric isochoric heating to generate and study warm-dense matter at high densities. These beam plasmas have been directed also at a thick Ta disk to generate a directed, intense point-like Bremsstrahlung source of photons peaked at ˜2 MeV and used it for point projection radiography of thick high density objects. In addition, prior work on the intense neutron beam driven by an intense deuterium beam generated in the RIT regime has been extended. Neutron spectral control by means of a flexible converter-disk design has been demonstrated, and the neutron beam has been used for point-projection imaging of thick objects. The plans and prospects for further improvements and applications are also discussed.

Synthesis and structural studies of lithium and sodium complexes with OOO-tridentate bis(phenolate) ligands: effective catalysts for the ring-opening polymerization of L-lactide.

PubMed

Huang, Yong; Tsai, Yueh-Hsuan; Hung, Wen-Chou; Lin, Chieh-Shen; Wang, Wei; Huang, Jui-Hsien; Dutta, Saikat; Lin, Chu-Chieh

2010-10-18

A series of lithium and sodium complexes with OOO-tridentate bis(phenolate) ligands have been synthesized and fully characterized. The reaction of 2,2'-dihydroxy-3,3',5,5'-tetrakis[(1-methyl-1-phenyl)ethyl]dibenzyl ether (L(1)-H(2)) with different ratios of (n)BuLi in toluene or tetrahydrofuran (THF) gave [Li(2)(L(1)-H)(2)] (1), [Li(4)L(1)(2)] (2), and [Li(2)L(1)(THF)(3)] (3), respectively. Similarly, [Na(L(1)-H)(THF)] (4), [Na(2)(L(1)-H)](2) (5), and [Na(4)L(1)(2)] (6) were prepared by the reaction of L(1)-H(2) and NaN[Si(CH(3))(3)](2) or sodium metal. In addition, the reaction of 2,2'-dihydroxy-3,3',5,5'-tetra-tert-butyldibenzyl ether (L(2)-H(2)) with (n)BuLi in toluene or THF yields Li(2)(L(2)-H)(2)] (7) and [Li(2)(L(2)-H)(2)(THF)(2)] (8), respectively. Further treatment of 7 with 2 mol equiv of benzyl alcohol provides [Li(2)(L(2)-H)(2)(BnOH)(2)] (9). Complexes 1-4 and 6-9 have been structurally characterized by single-crystal X-ray analysis. The dinuclear nature of complexes 1 and 3 was confirmed from their molecular structure. Complexes 2 and 6 illustrate tetranuclear species; however, complex 4 shows a mononuclear feature. A p-π interaction exists from the phenyl ring of the 2-(methyl-1-phenylethyl) groups to the central metal in complexes 2, 4, and 6, which could effectively stabilize the metal center. Among them, complexes 1, 2, and 5-9 displayed efficient catalytic behavior for the ring-opening polymerization of L-lactide in the presence of benzyl alcohol. Experimental results indicate that among these alkali-metal complexes, the sodium compound 6 displays a rapid catalytic polymerization of L-lactide in "living" fashion, yielding poly(L-lactide) with a controlled molecular weight and narrow polydispersity indices for a wide range of monomer-to-initiator ratios.

Laser-plasmas in the relativistic-transparency regime: science and applications

DOE PAGES

Fernandez, Juan Carlos; Gautier, Donald Cort; Huang, Chengkun; ...

2017-05-30

Laser-plasma interactions in the novel regime of relativistically induced transparency (RIT) have been harnessed to generate intense ion beams efficiently with average energies exceeding 10 MeV/nucleon (>100 MeV for protons) at “table-top” scales in experiments at the LANL Trident Laser. By further optimization of the laser and target, the RIT regime has been extended into a self-organized plasma mode. This mode yields an ion beam with much narrower energy spread while maintaining high ion energy and conversion efficiency. This mode involves self-generation of persistent high magnetic fields (~10 4 T, according to particle-in-cell simulations of the experiments) at the rear-sidemore » of the plasma. These magnetic fields trap the laser-heated multi-MeV electrons, which generate a high localized electrostatic field (~0.1 TV/m). After the laser exits the plasma, this electric field acts on a highly structured ion-beam distribution in phase space to reduce the energy spread, thus separating acceleration and energy-spread reduction. Thus, ion beams with narrow energy peaks at up to 18 MeV/nucleon are generated reproducibly with high efficiency (≈5%). The experimental demonstration has been done with 0.12 PW, high-contrast, 0.6 ps Gaussian 1.053 μm laser pulses irradiating planar foils up to 250 nm thick at 2–8 × 10 20 W/cm 2. These ion beams with co-propagating electrons have been used on Trident for uniform volumetric isochoric heating to generate and study warm-dense matter at high densities. These beam plasmas have been directed also at a thick Ta disk to generate a directed, intense point-like Bremsstrahlung source of photons peaked at ~2 MeV and used it for point projection radiography of thick high density objects. In addition, prior work on the intense neutron beam driven by an intense deuterium beam generated in the RIT regime has been extended. Neutron spectral control by means of a flexible converter-disk design has been demonstrated, and the neutron beam has been used for point-projection imaging of thick objects. Finally, we discuss the plans and prospects for further improvements and applications.« less

Selected indicators and determinants of women's health in the vicinity of a copper mine development in northwestern Zambia.

PubMed

Knoblauch, Astrid M; Divall, Mark J; Owuor, Milka; Musunka, Gertrude; Pascall, Anna; Nduna, Kennedy; Ng'uni, Harrison; Utzinger, Jürg; Winkler, Mirko S

2018-05-01

Large projects in the extractive industry sector can affect people's health and wellbeing. In low- and middle-income countries (LMICs), women's health is of particular concern in such contexts due to potential educational and economic disadvantages, vulnerability to transactional sex and unsafe sex practices. At the same time, community health interventions and development initiatives present opportunities for women's and maternal health. Within the frame of the health impact assessment (HIA) of the Trident copper mining project in Zambia, two health surveys were conducted (baseline in 2011 and follow-up in 2015) in order to monitor health and health-related indicators. Emphasis was placed on women residing in the mining area and, for comparison, in settings not impacted by the project. All measured indicators improved over time, regardless of whether communities were affected by the project or not. Additionally, the percentage of mothers giving birth in a health facility, the percentage of women who acknowledge that HIV cannot be transmitted by witchcraft or other supernatural means and the percentage of women having ever tested for HIV showed a significant increase in the impacted sites but not in the comparison communities. In 2015, better health, behavioural and knowledge outcomes in women were associated with employment by the project (or a sub-contractor thereof), migration background, increased wealth and higher educational attainment. Our study reveals that natural resource development projects can positively impact women's health, particularly if health risks are adequately anticipated and managed. Hence, the conduct of a comprehensive HIA should be a requirement at the feasibility stage of any large infrastructure project, particularly in LMICs. Continued monitoring of health outcomes and wider determinants of health after the initial assessment is crucial to judge the project's influence on health and for reducing inequalities over time.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niemann, Christoph; Gekelman, W.; Winske, D.

We have performed several thousand high-energy laser shots in the LAPD to investigate the dynamics of an exploding laser-produced plasma in a large ambient magneto-plasma. Debris-ions expanding at super-Alfvenic velocity (up to MA=1.5) expel the ambient magnetic field, creating a large (> 20 cm) diamagnetic cavity. We observed field compressions of up to B/B{sub 0} = 1.5 at the edge of the bubble, consistent with the MHD jump conditions, as well as localized electron heating at the edge of the bubble. Two-dimensional hybrid simulations reproduce these measurements well and show that the majority of the ambient ions are energized bymore » the magnetic piston to super-Alfvenic speeds and swept outside the bubble volume. Nonlinear shear-Alfven waves ({delta}B/B{sub 0} > 25%) are radiated from the cavity with a coupling efficiency of 70% from magnetic energy in the bubble to the wave. While the data is consistent with a weak magneto-sonic shock, the experiments were severely limited by the low ambient plasma densities (10{sup 12} cm{sup -3}). 2D hybrid simulations indicate that future experiments with the new LAPD plasma source and densities in excess of 10{sup 13} cm{sup -3} will drive full-blown collisionless shocks with MA>10 over several c/wpi and shocked Larmor radii. In a separate experiment at the LANL Trident laser facility we have performed a proof-of-principle experiment at higher densities to demonstrate key elements of collisionless shocks in laser-produced magnetized plasmas with important implications to NIF. Simultaneously we have upgraded the UCLA glass-laser system by adding two large amplitude disk amplifiers from the NOVA laser and boost the on-target energy from 30 J to up to 1 kJ, making this one of the world’s largest university-scale laser systems. We now have the infrastructure in place to perform novel and unique high-impact experiments on collision-less shocks at the LAPD.« less

Progress of Chiral Schiff Bases with C1 Symmetry in Metal-Catalyzed Asymmetric Reactions.

PubMed

Hayashi, Masahiko

2016-12-01

In this Personal Account, various chiral Schiff base-metal-catalyzed enantioselective organic reactions are reported; the Schiff bases used were O,N,O- as well as N,N,P-tridentate ligands and N,N-bidentate ligands having C 1 symmetry. In particular, the enantioselective addition of trimethylsilyl cyanide, dialkylzinc, and organozinc halides to aldehydes, enantioselective 1,4-addition of dialkylzinc to cyclic and acyclic enones, and asymmetric allylic oxidation are reported. Typically, ketimine-type Schiff base-metal complexes exhibited higher reactivity and enantioselectivity compared with the corresponding aldimine-type Schiff base-metal complexes. Notably, remarkable ligand acceleration was observed for all reactions. The obtained products can be used as key intermediates for optically active natural products and pharmaceuticals. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Coordination properties of tridentate (N,O,O) heterocyclic alcohol (PDC) with Cu(II). Mixed ligand complex formation reactions of Cu(II) with PDC and some bio-relevant ligands.

PubMed

El-Sherif, Ahmed A; Shoukry, Mohamed M

2007-03-01

The formation equilibria of copper(II) complexes and the ternary complexes Cu(PDC)L (PDC=2,6-bis-(hydroxymethyl)-pyridine, HL=amino acid, amides or DNA constituents) have been investigated. Ternary complexes are formed by a simultaneous mechanism. The results showed the formation of Cu(PDC)L, Cu(PDC, H(-1))(L) and Cu(PDC, H(-2))(L) complexes. The concentration distribution of the complexes in solution is evaluated as a function of pH. The effect of dioxane as a solvent on the protonation constant of PDC and the formation constants of Cu(II) complexes are discussed. The thermodynamic parameters DeltaH degrees and DeltaS degrees calculated from the temperature dependence of the equilibrium constants are investigated.

Synthesis, structural characterization, DFT studies and in-vitro antidiabetic activity of new mixed ligand oxovanadium(IV) complex with tridentate Schiff base

NASA Astrophysics Data System (ADS)

Patel, R. N.; Singh, Yogendra Pratap

2018-02-01

The mixed ligand oxovanadium(IV) complex [VO(L1)(L2)] [L1 = N'-[(Z)-phenyl(pyridin-2-yl)methylidene]benzohydrazide and L2 = Benzohydrazide] has been synthesized in aerobic condition. The complex was characterized by elemental analysis spectroscopic (UV-vis, IR, epr) and electrochemical methods. X-ray diffraction pattern was also used to characterize this complex, which has a distorted octahedral structure. Single crystal diffraction analysis reveals that Csbnd H⋯π (aryl/metal chelate rings) interactions contribute to the stabilization of the crystal structure in given dimension. The room temperature magnetic susceptibility data shows paramagnetic nature of the complex. The complex was also tested for in-vitro antidiabetic activity. Moderate α-glucosidase inhibition is shown by this complex, which may be considered as α-glucosidase inhibitors.

Synthesis, structural studies and reactivity of vanadium complexes with tridentate (OSO) ligand.

PubMed

Janas, Zofia; Wiśniewska, Dorota; Jerzykiewicz, Lucjan B; Sobota, Piotr; Drabent, Krzysztof; Szczegot, Krzysztof

2007-05-28

The direct reaction between [VCl(3)(thf)3] or [VO(OEt)3] and 2,2'-thiobis{4-(1,1,3,3-tetramethyl-butyl)phenol (tbopH(2)) leads to the formation of [V(2)(micro-tbop-kappa(3)O,S,O)2Cl(2)(CH(3)CN)(2)] (1).4CH(3)CN or [V(2)(micro-OEt)2(O)2(tbop-kappa(3)O,S,O)2] (2), respectively, in high yield. Compounds 1 and 2 were characterized by chemical and physical techniques including X-ray crystallography and variable temperature magnetic susceptibility studies (J = -29.1 cm(-1)) for 1. Complexes 1 and 2 were supported on MgCl2 and when activated with aluminium alkyls, were found to effectively polymerize ethene to produce polyethylene with a narrow molecular weight distribution M(w)/M(n) approximately 3.

Demonstrated Efficient Quasi-Monoenergetic Carbon-Ion Beams Approaching Fast Ignition (FI) Requirements

NASA Astrophysics Data System (ADS)

Fernández, Juan C.; Palaniyappan, S.; Huang, C.; Gautier, D. C.; Santiago, M.

2015-11-01

Using massive computer simulations of relativistic laser-plasma interactions, we have identified a self-organizing scheme that exploits persisting self-generated plasma electric (~TV/m) and magnetic (~104 Tesla) fields to reduce the ion energy spread of intense laser-driven ion beams after the laser exits the plasma. Consistent with the scheme, we have demonstrated on the LANL Trident laser carbon-ion beams with narrow spectral peaks at 220 MeV, with high conversion efficiency (~ 5%). These parameters are within a factor of 2 of FI requirements. The remaining gap may be bridged by increasing the laser intensity by a factor of 4, according to our data. We also discuss how this beam may be focused, to address the remaining requirement for FI, besides the total laser energy. This work is sponsored by the LANL LDRD Program.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sergienko, V. S., E-mail: sergienko@igic.ras.ru; Martsinko, E. E.; Seifullina, I. I.

The synthesis and X-ray diffraction study of compound ([Ag{sub 2}Ge(HCit){sub 2}(H{sub 2}O){sub 2}] ∙ 2H{sub 2}O){sub n}, where H{sub 4}Cit is the citric acid, are performed. In the polymeric structure, the HCit{sup 3–} ligand fulfils the tetradentate chelate–μ{sub 4}-bridging (3Ag, Ge) function (tridentate with respect to Ge and Ag atoms). The Ge atom is octahedrally coordinated by six O atoms of two HCit{sup 3–}ligands. The coordination polyhedron of the Ag atom is an irregular five-vertex polyhedron [four O atoms of four HCit{sup 3–} ligands and the O(H{sub 2}O) atom]. An extended system of O–H···O hydrogen bonds connects complex molecules intomore » a supramolecular 3D-framework.« less

Dichlorido[N′-(3,5-dichloro-2-hydroxy­benzyl­idene)pyridine-4-carbohydrazide-κN](1,10-phenanthroline-κ2 N,N′)cobalt(II) methanol monosolvate

PubMed Central

Wang, Yuan; Liu, Zheng; Liu, Baoyu

2009-01-01

In the title compound, [CoCl2(C13H9Cl2N3O2)2(C12H8N2)]·CH3OH, the CoII atom is octahedrally coordinated by two N atoms from the pyridyl rings of the tridentate N′-(3,5-dichloro-2-hydroxy­benzyl­idene)pyridine-4-carbohydrazide (H2 L) ligand, two N atoms from the 1,10-phenanthroline ligand and two chloride ions. The acyl­hydrazone groups are not involved into the coordination of the metal ion. In the crystal packing an extended three-dimensional network formed by N—H⋯Cl, N—H⋯O, O—H⋯N, O—H⋯N and O—H⋯Cl hydrogen bonds is observed. PMID:21578623

Mission Level Autonomy for USSV

NASA Technical Reports Server (NTRS)

Huntsberger, Terry; Stirb, Robert C.; Brizzolara, Robert

2011-01-01

On-water demonstration of a wide range of mission-proven, advanced technologies at TRL 5+ that provide a total integrated, modular approach to effectively address the majority of the key needs for full mission-level autonomous, cross-platform control of USV s. Wide baseline stereo system mounted on the ONR USSV was shown to be an effective sensing modality for tracking of dynamic contacts as a first step to automated retrieval operations. CASPER onboard planner/replanner successfully demonstrated realtime, on-water resource-based analysis for mission-level goal achievement and on-the-fly opportunistic replanning. Full mixed mode autonomy was demonstrated on-water with a seamless transition between operator over-ride and return to current mission plan. Autonomous cooperative operations for fixed asset protection and High Value Unit escort using 2 USVs (AMN1 & 14m RHIB) were demonstrated during Trident Warrior 2010 in JUN 2010

Coordination Polymerization of Renewable 3-Methylenecyclopentene with Rare-Earth-Metal Precursors.

PubMed

Liu, Bo; Li, Shihui; Wang, Meiyan; Cui, Dongmei

2017-04-10

Coordination polymerization of renewable 3-methylenecyclopentene has been investigated for the first time using rare-earth metal-based precursors bearing various bulky ligands. All the prepared complexes catalyze controllable polymerization of 3-methylenecyclopentene into high molecular weight polymers, of which the NPN- and NSN-tridentate non-Cp ligated lutetium-based catalytic systems exhibited extremely high activities up to 11 520 kg/(mol Lu ⋅h) in a dilute toluene solution (3.2 g/100 mL) at room temperature. The resultant polymers have pure 1,4-regioregularity (>99 %) and tailorable number average molecular weights (1-20×10 4 ) with narrow molecular weight distributions (polydispersity index (PDI)=1.45-1.79). DFT simulations were employed to study the polymerization mechanism and stereoregularity control. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diastereoselective formation of metallamacrocyclic (arene)Ru(II) and CpRh(III) complexes.

PubMed

Lehaire, Marie-Line; Scopelliti, Rosario; Herdeis, Lorenz; Polborn, Kurt; Mayer, Peter; Severin, Kay

2004-03-08

The reaction of [(arene)RuCl(2)](2) (arene = cymene, 1,3,5-C(6)H(3)Me(3)) and [CpRhCl(2)](2) half-sandwich complexes with tridentate heterocyclic ligands in the presence of base has been investigated. In all cases, the chloro-ligands were substituted to give metallacyclic products with ring sizes between 4 and 18 atoms. The cyclization occurs in a highly diastereoselective fashion with chiral recognition between the different metal fragments. The complexes were comprehensively characterized by elemental analysis, NMR spectroscopy, and single crystal X-ray crystallography. For 2-hydroxy-nicotinic acid and 2-amino-nicotinic acid, dinuclear structures were obtained (15-17) whereas for 2,3-dihydroxyquinoline, 2,3-dihydroxyquinoxaline, and 6-methyl-2,3-phenazinediol, trimeric assemblies were found (19-22), and for 4-imidazolecarboxylic acid, a tetrameric assembly (18) was found.

Bis(2,3,5,6-tetra-2-pyridylpyrazine-κ3 N 2,N 1,N 6)iron(II) bis­(dicyanamidate) 4.5-hydrate

PubMed Central

Callejo, L.; De la Pinta, N.; Madariaga, G.; Fidalgo, M.L.; Cortés, R.

2010-01-01

In the title compound, [Fe(C24H16N6)2][N(CN)2]2·4.5H2O, the central iron(II) ion is hexa­coordinated by six N atoms of two tridentate 2,3,5,6-tetra-2-pyridylpyrazine (tppz) ligands. Two dicyanamide anions [dca or N(CN)2 −] act as counter-ions, and 4.5 water mol­ecules act as solvation agents. The structure contains isolated cationic iron(II)–tppz complexes and the final neutrality is obtained with the two dicyanamide anions. One of the dicyanamide anions and a water mol­ecule are disordered with an occupancy ratio of 0.614 (8):0.386 (8). O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds involving dca, water and tppz mol­ecules are observed. PMID:21580205

Laser-launched flyers with organic working fluids

NASA Astrophysics Data System (ADS)

Mulford, Roberta; Swift, Damian

2003-10-01

The TRIDENT laser has been used to launch flyers by depositing IR energy in a thin layer of material - the working fluid - sandwiched between the flyer and a transparent substrate. We have investigated the use of working fluids based on organics, chosen as they are quite efficient absorbers of IR energy and should also convert heat to mechanical work more efficiently than materials such as carbon. A thermodynamically complete equation of state was developed for one of the fluids investigated experimentally - a carbohydrate solution - by chemical equilibrium calculations using the CHEETAH program. Continuum mechanics simulations were made of the flyer launch process, modeling the effect of the laser as energy deposition in the working fluid, and taking into account the compression and recoil of the substrate. We compare the simulations with a range of experiments and demonstrate the optimization of substrate and fluid thickness for a given flyer thickness and speed.

Theoretical and experimental studies of the waveforms associated with stratospheric infrasonic returns

NASA Astrophysics Data System (ADS)

Waxler, R.; Talmadge, C. L.; Blom, P.

2009-12-01

Theory predicts that for ground to ground infrasound propagation along paths which travel downwind, relative to the stratospheric jet, there is a shadow zone which ends about 200 km from the source where the first return from the stratosphere strikes the earth. With increasing range the single stratospheric arrival splits into two distinct arrivals, a fast arrival with the trace velocity of the effective sound speed at the stratopause, and a slower arrival with the trace velocity of the sound speed on the ground. To test the theory we have deployed eight infrasound arrays along an approximate line directly west of the site of the US Navy's Trident Missile rocket motor eliminations. The arrays were deployed during the summer of 2009 spaced roughly 10 km apart along a segment from 180 to 260 km west of the site. Comparisons between the theoretical predictions and the received data will be presented.

Molecular, crystal, and electronic structure of the cobalt(II) complex with 10-(2-benzothiazolylazo)-9-phenanthrol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linko, R. V., E-mail: rlinko@mail.ru; Sokol, V. I.; Polyanskaya, N. A.

2013-05-15

The reaction of 10-(2-benzothiazolylazo)-9-phenanthrol (HL) with cobalt(II) acetate gives the coordination compound [CoL{sub 2}] {center_dot} CHCl{sub 3} (I). The molecular and crystal structure of I is determined by X-ray diffraction. The coordination polyhedron of the Co atom in complex I is an octahedron. The anion L acts as a tridentate chelating ligand and is coordinated to the Co atom through the phenanthrenequinone O1 atom and the benzothiazole N1 atom of the moieties L and the N3 atom of the azo group to form two five-membered metallocycles. The molecular and electronic structures of the compounds HL, L, and CoL{sub 2} aremore » studied at the density functional theory level. The results of the quantum-chemical calculations are in good agreement with the values determined by X-ray diffraction.« less

Synthesis and spectral studies of heterocyclic azo dye complexes with some transition metals

NASA Astrophysics Data System (ADS)

Jarad, A. J.; Majeed, I. Y.; Hussein, A. O.

2018-05-01

6-(2-benzathiazolyl azo) -3,5-dimethylphenol was formed by grouping the 2-benzothiazole diazonium chloride with 3,5-dimethylphenol. Azo ligand(L) was resolved on the origin by 1H and 13CNMR, FTIR and UV-Vis spectral analysis. Complexation of tridentate ligand (L) with Co2+, Ni2+, Cu2+ and Zn2+ in aqueous of ethyl alcohol with a 1:2 metal:ligand, and at ideal pH.. The formation of metal chelates are assigned using flame atomic absorption, FTIR and UV-Vis spectral analysis, other than conductivity and magnetic estates. The nature of the metal chelates were carried out by mole ratio and continuous variation mechanism, Beer’s law followed the rate (0.0001 - 3×0.0001 M) concentration. High molar absorptivity for the complex solutions were observed. On the origin data an octahedral geometry were described for the metal chelates. Biological activity of the ready compounds were assayed.

(2-{[2-(1H-Benzimidazol-2-yl-κN 3)phen­yl]imino­methyl-κN}-5-methyl­phenolato-κO)chloridozinc(II)

PubMed Central

Eltayeb, Naser Eltaher; Teoh, Siang Guan; Chantrapromma, Suchada; Fun, Hoong-Kun

2011-01-01

In the title mononuclear complex, [Zn(C21H16N3O)Cl], the ZnII ion is coordinated in a distorted tetra­hedral geometry by two benzimidazole N atoms and one phenolate O atom from the tridentate Schiff base ligand and a chloride ligand. The benzimidazole ring system forms dihedral angles of 26.68 (9) and 56.16 (9)° with the adjacent benzene ring and the methyl­phenolate group benzene ring, respectively. In the crystal, mol­ecules are linked by N—H⋯Cl hydrogen bonds into chains along [100]. Furthermore, weak C—H⋯O and C—H⋯π inter­actions, in addition to π–π inter­actions with centroid–centroid distances in the range 3.5826 (13)–3.9681 (13) Å, are also observed. PMID:22065469

Palladium(II) complexes bearing di-(2-picolyl)amine functionalized chrysin fragments. An experimental and theoretical study

NASA Astrophysics Data System (ADS)

González-Montiel, Simplicio; Valdez-Calderón, Alejandro; Vásquez-Pérez, J. Manuel; Torres-Valencia, J. Martín; Martínez-Otero, Diego; López, Jorge A.; Cruz-Borbolla, Julián

2017-10-01

A new series of chrysin derivatives containing the di-(2-picolyl)amine (2a-d) moiety have been designed, synthesized, and treated with PdCl2·2CH3CN allowing the preparation of new cationic Palladium(II) complexes (3a-d). Solution-phase studies by 1H NMR spectroscopy of 3a-d revealed that the protons of the methylene groups of the di(2-picolyl)amine fragment are diasterotopic. GIAO/DFT studies were performed to predict the molecular structures of 3a-d by comparing the experimental and theoretical 1H-NMR chemical shifts. The molecular structure of 3c was determined by X-ray crystallographic analysis revealing that di-(2-picolyl)amine fragment is coordinated to the palladium center in a κ3-N,N,N-tridentate fashion in an overall square-planar geometry completed with a chloride atom.

Observation of Langmuir Cascade in Single Hot Spot Laser-Plasma Experiments

NASA Astrophysics Data System (ADS)

Johnson, R. P.; Montgomery, D. S.; Fernandez, J. C.; Focia, R. J.

2001-10-01

We present results from the sixth in a series of experiments designed to investigate the interaction of a single laser hot spot, or speckle, with a preformed, quasi-homogeneous plasma. The experiments were conducted at the Los Alamos National Laboratory (LANL) using the TRIDENT laser. Thomson scattering was used to probe plasma waves driven by stimulated Raman scattering (SRS) and structure was observed in the scattered spectra consistent with multiple steps of the Langmuir decay instability (LDI).(R. J. Focia et al., PSFC Report PSFC/JA-01-17, M.I.T.) The experimental setup is described. The Thomson scattered spectra, resolved in both wavelength versus time and wavelength versus wave vector (effectively ω vs. k), are well-correlated with measurements of the backscattered SRS light and calculations based on linear theory. Parameter regimes are identified in which the LDI cascade exists.

Vertical nuclear proliferation.

PubMed

Sidel, Victor W

2007-01-01

All the nuclear-weapon states are working to develop new nuclear-weapon systems and upgrade their existing ones. Although the US Congress has recently blocked further development of small nuclear weapons and earth-penetrating nuclear weapons, the United States is planning a range of new warheads under the Reliable Replacement Warhead programme, and renewing its nuclear weapons infrastructure. The United Kingdom is spending 1 billion pounds sterling on updating the Atomic Weapons Establishment at Aldermaston, and about 20 billion pounds sterling on replacing its Vanguard submarines and maintaining its Trident warhead stockpile. The US has withdrawn from the Anti-Ballistic Missile Treaty and plans to install missile defence systems in Poland and the Czech Republic; Russia threatens to upgrade its nuclear countermeasures. The nuclear-weapon states should comply with their obligations under Article VI of the Non-Proliferation Treaty, as summarised in the 13-point plan agreed at the 2000 NPT Review Conference, and they should negotiate a Nuclear Weapons Convention.

Social Inequality, Life Course Transitions, and Adolescent Development: Introduction to the Special Issue.

PubMed

Buchmann, Marlis; Steinhoff, Annekatrin

2017-10-01

Conceptualizing adolescent development within a life course framework that links the perspectives on social inequality and early life course transitions has largely been absent from previous research. Such a conceptual model is needed, however, in order to understand how the individual development of agentic capacities and the opportunities and constraints inherent in the social contexts of growing up interact and jointly affect young people's trajectories across the adolescent life stage. We present the corner stones of the conceptual "trident" of social inequality, life course transitions, and adolescent development and identify three major themes the eleven contributions to this special issue address within this conceptual framework: social and individual prerequisites and consequences of coping with life course transitions; intergenerational transmission belts of social inequality; socialization of agency in and outside the family home. These three themes exemplify the great analytical potential inherent in this framework.

Phosphonic Acids on an Atomically Defined Oxide Surface: The Binding Motif Changes with Surface Coverage.

PubMed

Schuschke, Christian; Schwarz, Matthias; Hohner, Chantal; Silva, Thais N; Fromm, Lukas; Döpper, Tibor; Görling, Andreas; Libuda, Jörg

2018-04-19

We have studied the anchoring mechanism of a phosphonic acid on an atomically defined oxide surface. Using time-resolved infrared reflection absorption spectroscopy, we investigated the reaction of deuterated phenylphosphonic acid (DPPA, C 6 H 5 PO 3 D 2 ) with an atomically defined Co 3 O 4 (111) surface in situ during film growth by physical vapor deposition. We show that the binding motif of the phosphonate anchor group changes as a function of coverage. At low coverage, DPPA binds in the form of a chelating tridentate phosphonate, while a transition to a chelating bidentate occurs close to monolayer saturation coverage. However, the coverage-dependent change in the binding motif is not associated with a major change of the molecular orientation, suggesting that the rigid phosphonate linker always maintains the DPPA in a strongly tilted orientation irrespective of the surface coverage.

Improved ablative materials for the ASRM nozzle

NASA Technical Reports Server (NTRS)

Canfield, A.; Clinton, R. G.; Armour, W.; Koenig, J.

1992-01-01

Rayon precursor carbon-cloth phenolic was developed more than 30 years ago and is used in most nozzles today including the Poseidon, Trident, Peacekeeper, Small ICBM, Space Shuttle, and numerous tactical and space systems. Specifications and manufacturing controls were placed on these materials and, once qualified, a no-change policy was instituted. The current material is acceptable; however, prepreg variability does not always accommodate the requirements of automation. The advanced solid rocket motor requires material with less variability for automated manufacturing. An advanced solid rocket motor materials team, composed of NASA, Thiokol, Aerojet, SRI, and Lockheed specialists, along with materials suppliers ICI Fiberite/Polycarbon, BP Chemicals/Hitco, and Amoco, embarked on a program to improve the current materials. The program consisted of heat treatment studies and standard and low-density material improvements evaluation. Improvements evaluated included fiber/fabric heat treatments, weave variations, resin application methods, process controls, and monitors.

Structure and equilibria of Ca 2+-complexes of glucose and sorbitol from multinuclear ( 1H, 13C and 43Ca) NMR measurements supplemented with molecular modelling calculations

NASA Astrophysics Data System (ADS)

Pallagi, A.; Dudás, Cs.; Csendes, Z.; Forgó, P.; Pálinkó, I.; Sipos, P.

2011-05-01

Ca 2+-complexation of D-glucose and D-sorbitol have been investigated with the aid of multinuclear ( 1H, 13C and 43Ca) NMR spectroscopy and ab initio quantum chemical calculations. Formation constants of the forming 1:1 complexes have been estimated from one-dimensional 13C NMR spectra obtained at constant ionic strength (1 M NaCl). Binding sites were identified from 2D 1H- 43Ca NMR spectra. 2D NMR measurements and ab initio calculations indicated that Ca 2+ ions were bound in a tridentate manner via the glycosidic OH, the ethereal oxygen in the ring and the OH on the terminal carbon for the α- and β-anomers of glucose and for sorbitol simultaneous binding of four hydroxide moieties (C1, C2, C4 and C6) was suggested.

Copper(II) complexes of tridentate N, N, N', N″, N″-pentamethyldiethylenetriamine: Superoxide dismutase and inhibitory activity against bacteria and fungi

NASA Astrophysics Data System (ADS)

Patel, R. N.; Singh, Nripendra; Gundla, V. L. N.; Chauhan, U. K.

2007-03-01

A series of ternary copper(II) complexes containing same coordination sphere but difference in the counter ions, viz., [Cu(PMDT)(OAc)]PF 6(1); [Cu(PMDT)(OAc)]ClO 4(2); [Cu(PMDT)(OAc)]BF 4(3) and [Cu(PMDT)(OAc)]BPh 4(4) where PMDT = N, N, N', N″, N″-pentamethyldiethylenetriamine, OAc = Acetate ion were synthesized and characterized by means of spectroscopic, magnetic and cyclic voltammetric measurements. In frozen solution e.p.r. spectra, an interesting relation g|| > g⊥ has been observed which is a typical of the axially symmetric d 9 Cu II ( SCu = 1/2) having an unpaired electron in a d orbital. Single crystal X-ray analysis of (1) has revealed the presence of distorted square planar geometry. The influence of the counter ion on the complexes has been examined by performing some biological experiments like superoxide dismutase and anti-microbial activity.

DNA binding, anti-inflammatory and analgesic evaluation of metal complexes of N/S/O donor ligands; Synthesis, spectral characterization

NASA Astrophysics Data System (ADS)

Kumar Naik, K. H.; Ashok, B.; Naik, Nagaraja; Mulla, Jameel Ahmed S.; Prakasha, Avinash

2015-04-01

Transition metal complexes containing tri-dentate NSN donor ligands i.e., 5-((1(aminomethyl)cyclohexyl)methyl)-1,3,4-thiadiazol-2-amine (AMTA) (2) and 5-(2-aminophenyl)-1,3,4-thiadiazol-2-amine (ATA) (4i-ii) have been synthesized. The newly synthesized ligands and their respective complexes were characterized by elemental analysis, molar conductance measurement and various spectral studies [infrared (IR), electronic, and NMR (for ligands only)]. Metal complexes are like [M(AMTA)2], [M(ATA)2] type, where M = Mn(II), Co(II) and Cu(II). The proposed geometries of the complexes are octahedral in nature. The synthesized ligands and their complexes were exhibits effective anti-inflammatory, analgesic and DNA binding activities. All the tested compounds exhibited significant analgesic activity, whereas the compound 4i, 4(ia) and 4(iib) is equipotent with Diclofenac sodium.

Synthesis, characterization and anticancer activities of two lanthanide(III) complexes with a nicotinohydrazone ligand

NASA Astrophysics Data System (ADS)

Xu, Zhou-Qin; Mao, Xian-Jie; Jia, Lei; Xu, Jun; Zhu, Tao-Feng; Cai, Hong-Xin; Bie, Hong-Yan; Chen, Ru-Hua; Ma, Tie-liang

2015-12-01

Two isostructural acylhydrazone based complexes, namely [Ce(penh)2(H2O)4](NO3)3·4H2O (1) and [Sm(penh)2(NO3)2](NO3)·C2H5OH (2) (penh = 2-acetylpyridine nicotinohydrazone), have been obtained and characterized by physico-chemical and spectroscopic methods. The ten-coordinated lanthanide metal ion in each complex is surrounded by two independent tridentate neutral acylhydrazones with two ON2 donor sets. The other four coordination oxygen atoms are from four water molecules and two bidentate nitrate anions for complexes 1 and 2, respectively, thus giving distorted bicapped square antiprism geometry. Both complexes have excellent antitumor activity towards human pancreatic cancer (PATU8988), human colorectal cancer (lovo) and human gastric cancer(SGC7901) cell line. Furthermore, the cell apoptosis of complex 1 is detected by AnnexinV/PI flow cytometry.

Laser-plasmas in the relativistic-transparency regime: Science and applications

PubMed Central

Cort Gautier, D.; Palaniyappan, Sasikumar; Albright, Brian J.; Favalli, Andrea; Hunter, James F.; Mendez, Jacob; Roth, Markus; Deppert, Oliver; Espy, Michelle; Guler, Nevzat; Hamilton, Christopher; Hegelich, Bjorn Manuel; Henzlova, Daniela; Ianakiev, Kiril D.; Iliev, Metodi; Johnson, Randall P.; Kleinschmidt, Annika; Losko, Adrian S.; McCary, Edward; Mocko, Michal; Nelson, Ronald O.; Roycroft, Rebecca; Schanz, Victor A.; Schaumann, Gabriel; Schmidt, Derek W.; Sefkow, Adam; Taddeucci, Terry N.; Yin, Lin

2017-01-01

Laser-plasma interactions in the novel regime of relativistically induced transparency (RIT) have been harnessed to generate intense ion beams efficiently with average energies exceeding 10 MeV/nucleon (>100 MeV for protons) at “table-top” scales in experiments at the LANL Trident Laser. By further optimization of the laser and target, the RIT regime has been extended into a self-organized plasma mode. This mode yields an ion beam with much narrower energy spread while maintaining high ion energy and conversion efficiency. This mode involves self-generation of persistent high magnetic fields (∼104 T, according to particle-in-cell simulations of the experiments) at the rear-side of the plasma. These magnetic fields trap the laser-heated multi-MeV electrons, which generate a high localized electrostatic field (∼0.1 T V/m). After the laser exits the plasma, this electric field acts on a highly structured ion-beam distribution in phase space to reduce the energy spread, thus separating acceleration and energy-spread reduction. Thus, ion beams with narrow energy peaks at up to 18 MeV/nucleon are generated reproducibly with high efficiency (≈5%). The experimental demonstration has been done with 0.12 PW, high-contrast, 0.6 ps Gaussian 1.053 μm laser pulses irradiating planar foils up to 250 nm thick at 2–8 × 1020 W/cm2. These ion beams with co-propagating electrons have been used on Trident for uniform volumetric isochoric heating to generate and study warm-dense matter at high densities. These beam plasmas have been directed also at a thick Ta disk to generate a directed, intense point-like Bremsstrahlung source of photons peaked at ∼2 MeV and used it for point projection radiography of thick high density objects. In addition, prior work on the intense neutron beam driven by an intense deuterium beam generated in the RIT regime has been extended. Neutron spectral control by means of a flexible converter-disk design has been demonstrated, and the neutron beam has been used for point-projection imaging of thick objects. The plans and prospects for further improvements and applications are also discussed. PMID:28652684

X-Ray absorption spectroscopy quantitative analysis of biomimetic copper(II) complexes with tridentate nitrogen ligands mimicking the tris(imidazole) array of protein centres.

PubMed

Borghi, Elena; Casella, Luigi

2010-02-21

In this study copper(ii) complexes with the tridentate nitrogen ligand bis[2-(1-methylbenzimidazol-2-yl)ethyl]amine (2-BB) are considered as model compounds for the Cu-tris(imidazole) array found in several copper proteins. 2-BB chelates copper(ii) forming two six-membered rings and the complexes contain methanol, nitrite, azide and water as ancillary ligands; both the coordination numbers and stereochemistries differ in these complexes. Their key structural features were investigated by using full multiple-scattering theoretical analysis of the copper K-edge X-ray absorption spectrum with the MXAN code. We showed that using cluster sizes large enough to include all atoms of the ligand, the analysis of the XANES region can give both a structural model of the metal centre and map the structure of the 2-BB complexes. Complex [Cu(2-BB)(N(3))](+) provided a critical test through the comparison of the XANES simulation results with crystallographic data, thus permitting the extension of the method to the complex [Cu(2-BB)(H(2)O)(n)](+) (n = 1 or 2), for which crystallographic data are not available but is expected to bear a five-coordinated Cu(3N)(2O) core (n = 2). The structural data of [Cu(2-BB)(MeOH)(ClO(4))](+) and [Cu(2-BB)(NO(2))](+), both with a Cu(3N)(2O) core but with a different stereochemistry, were used as the starting parameters for two independent simulations of the XANES region of the [Cu(2-BB)(H(2)O)(2)](+) cation. The two structural models generated by simulation converge towards a structure for the aqua-cation with a lower coordination number. New calculations, where four-coordinated Cu(3N)(O) cores were considered as the starting structures, validated that the structure of the aqua-complex in the powder state has a copper(ii) centre with a four-coordinated Cu(3N)(O) core and a molecular formula [Cu(2-BB)(H(2)O)](ClO(4)).(H(2)O). A water solvation molecule, presumed to be disordered from the simulations with the two Cu(3N)(2O) cores, is present. The successful treatment of this Cu-2-BB complex system allows the extension of the method to other biomimetic compounds when a structural characterization is lacking.

Experience and lessons from health impact assessment guiding prevention and control of HIV/AIDS in a copper mine project, northwestern Zambia.

PubMed

Knoblauch, Astrid M; Divall, Mark J; Owuor, Milka; Nduna, Kennedy; Ng'uni, Harrison; Musunka, Gertrude; Pascall, Anna; Utzinger, Jürg; Winkler, Mirko S

2017-07-04

To avoid or mitigate potential project-related adverse health effects, the Trident copper project in Kalumbila, northwestern Zambia, commissioned a health impact assessment. HIV was identified a priority health issue based on the local vulnerability to HIV transmission and experience from other mining projects in Africa. Hence, an HIV/AIDS management plan was developed, including community and workplace interventions, with HIV testing and counselling (HTC) being one of the key components. We present trends in HTC data over a 4-year period. In 13 communities affected by the Trident project, HTC was implemented from 2012 onwards, using rapid diagnostic tests, accompanied by pre- and post-test counselling through trained personnel. In addition, HTC was initiated in the project workforce in 2013, coinciding with the launch of the mine development. HTC uptake and HIV positivity rates were assessed in the study population and linked to demographic factors using regression analysis. In total, 11,638 community members and 5564 workers have taken up HTC with an increase over time. The HIV positivity rate in the community was 3.0% in 2012 and 3.4% in 2015, while positivity rate in the workforce was 5.2% in 2013 and 4.3% in 2015. Females showed a significantly higher odds of having a positive test result than males (odds ratio (OR) = 1.96, 95% confidence interval (CI): 1.55-2.50 among women in the community and OR = 2.90, 95% CI: 1.74-4.84 among women in the workforce). HTC users in the 35-49 years age group were most affected by HIV, with an average positivity rate of 6.6% in the community sample and 7.9% in the workforce sample. These study groups had 4.50 and 4.95 higher odds of being positive, respectively, compared to their younger counterparts (15-24 years). While HTC uptake increased five-fold in the community and almost three-fold in the workplace, the HIV positivity rates were insignificantly higher in 2015 compared to 2012. Our data can be used alongside other surveillance data to track HIV transmission in this specific context. Guided by the health impact assessment, the HIV prevention and control programme was readily adapted to the current setting through the identification of socioeconomic and environmental determinants of health.

Oxidation of benzoin catalyzed by oxovanadium(IV) schiff base complexes

PubMed Central

2013-01-01

Background The oxidative transformation of benzoin to benzil has been accomplished by the use of a wide variety of reagents or catalysts and different reaction procedures. The conventional oxidizing agents yielded mainly benzaldehyde or/and benzoic acid and only a trace amount of benzil. The limits of practical utilization of these reagents involves the use of stoichiometric amounts of corrosive acids or toxic metallic reagents, which in turn produce undesirable waste materials and required high reaction temperatures. In recent years, vanadium complexes have attracted much attention for their potential utility as catalysts for various types of reactions. Results Active and selective catalytic systems of new unsymmetrical oxovanadium(IV) Schiff base complexes for the oxidation of benzoin is reported. The Schiff base ligands are derived between 2-aminoethanol and 2-hydroxy-1-naphthaldehyde (H2L1) or 3-ethoxy salicylaldehyde (H2L3); and 2-aminophenol and 3-ethoxysalicylaldehyde (H2L2) or 2-hydroxy-1-naphthaldehyde (H2L4). The unsymmetrical Schiff bases behave as tridentate dibasic ONO donor ligands. Reaction of these Schiff base ligands with oxovanadyl sulphate afforded the mononuclear oxovanadium(IV) complexes (VIVOLx.H2O), which are characterized by various physico-chemical techniques. The catalytic oxidation activities of these complexes for benzoin were evaluated using H2O2 as an oxidant. The best reaction conditions are obtained by considering the effect of solvent, reaction time and temperature. Under the optimized reaction conditions, VOL4 catalyst showed high conversion (>99%) with excellent selectivity to benzil (~100%) in a shorter reaction time compared to the other catalysts considered. Conclusion Four tridentate ONO type Schiff base ligands were synthesized. Complexation of these ligands with vanadyl(IV) sulphate leads to the formation of new oxovanadium(IV) complexes of type VIVOL.H2O. Elemental analyses and spectral data of the free ligands and their oxovanadium(IV) complexes were found to be in good agreement with their structures, indicating high purity of all the compounds. Oxovanadium complexes were screened for the oxidation of benzoin to benzil using H2O2 as oxidant. The effect of time, solvent and temperature were optimized to obtain maximum yield. The catalytic activity results demonstrate that these catalytic systems are both highly active and selective for the oxidation of benzoin under mild reaction conditions. PMID:23294561

Oxidation of benzoin catalyzed by oxovanadium(IV) schiff base complexes.

PubMed

Alsalim, Tahseen A; Hadi, Jabbar S; Ali, Omar N; Abbo, Hanna S; Titinchi, Salam Jj

2013-01-07

The oxidative transformation of benzoin to benzil has been accomplished by the use of a wide variety of reagents or catalysts and different reaction procedures. The conventional oxidizing agents yielded mainly benzaldehyde or/and benzoic acid and only a trace amount of benzil. The limits of practical utilization of these reagents involves the use of stoichiometric amounts of corrosive acids or toxic metallic reagents, which in turn produce undesirable waste materials and required high reaction temperatures.In recent years, vanadium complexes have attracted much attention for their potential utility as catalysts for various types of reactions. Active and selective catalytic systems of new unsymmetrical oxovanadium(IV) Schiff base complexes for the oxidation of benzoin is reported. The Schiff base ligands are derived between 2-aminoethanol and 2-hydroxy-1-naphthaldehyde (H2L1) or 3-ethoxy salicylaldehyde (H2L3); and 2-aminophenol and 3-ethoxysalicylaldehyde (H2L2) or 2-hydroxy-1-naphthaldehyde (H2L4). The unsymmetrical Schiff bases behave as tridentate dibasic ONO donor ligands. Reaction of these Schiff base ligands with oxovanadyl sulphate afforded the mononuclear oxovanadium(IV) complexes (VIVOLx.H2O), which are characterized by various physico-chemical techniques.The catalytic oxidation activities of these complexes for benzoin were evaluated using H2O2 as an oxidant. The best reaction conditions are obtained by considering the effect of solvent, reaction time and temperature. Under the optimized reaction conditions, VOL4 catalyst showed high conversion (>99%) with excellent selectivity to benzil (~100%) in a shorter reaction time compared to the other catalysts considered. Four tridentate ONO type Schiff base ligands were synthesized. Complexation of these ligands with vanadyl(IV) sulphate leads to the formation of new oxovanadium(IV) complexes of type VIVOL.H2O.Elemental analyses and spectral data of the free ligands and their oxovanadium(IV) complexes were found to be in good agreement with their structures, indicating high purity of all the compounds.Oxovanadium complexes were screened for the oxidation of benzoin to benzil using H2O2 as oxidant. The effect of time, solvent and temperature were optimized to obtain maximum yield. The catalytic activity results demonstrate that these catalytic systems are both highly active and selective for the oxidation of benzoin under mild reaction conditions.

ImageX: new and improved image explorer for astronomical images and beyond

NASA Astrophysics Data System (ADS)

Hayashi, Soichi; Gopu, Arvind; Kotulla, Ralf; Young, Michael D.

2016-08-01

The One Degree Imager - Portal, Pipeline, and Archive (ODI-PPA) has included the Image Explorer interactive image visualization tool since it went operational. Portal users were able to quickly open up several ODI images within any HTML5 capable web browser, adjust the scaling, apply color maps, and perform other basic image visualization steps typically done on a desktop client like DS9. However, the original design of the Image Explorer required lossless PNG tiles to be generated and stored for all raw and reduced ODI images thereby taking up tens of TB of spinning disk space even though a small fraction of those images were being accessed by portal users at any given time. It also caused significant overhead on the portal web application and the Apache webserver used by ODI-PPA. We found it hard to merge in improvements made to a similar deployment in another project's portal. To address these concerns, we re-architected Image Explorer from scratch and came up with ImageX, a set of microservices that are part of the IU Trident project software suite, with rapid interactive visualization capabilities useful for ODI data and beyond. We generate a full resolution JPEG image for each raw and reduced ODI FITS image before producing a JPG tileset, one that can be rendered using the ImageX frontend code at various locations as appropriate within a web portal (for example: on tabular image listings, views allowing quick perusal of a set of thumbnails or other image sifting activities). The new design has decreased spinning disk requirements, uses AngularJS for the client side Model/View code (instead of depending on backend PHP Model/View/Controller code previously used), OpenSeaDragon to render the tile images, and uses nginx and a lightweight NodeJS application to serve tile images thereby significantly decreasing the Time To First Byte latency by a few orders of magnitude. We plan to extend ImageX for non-FITS images including electron microscopy and radiology scan images, and its featureset to include basic functions like image overlay and colormaps. Users needing more advanced visualization and analysis capabilities could use a desktop tool like DS9+IRAF on another IU Trident project called StarDock, without having to download Gigabytes of FITS image data.

A new mixed-ligand copper(II) complex of (E)-N";-(2-hydroxybenzylidene) acetohydrazide: Synthesis, characterization, NLO behavior, DFT calculation and biological activities

NASA Astrophysics Data System (ADS)

Yousef Ebrahimipour, S.; Sheikhshoaie, Iran; Crochet, Aurelien; Khaleghi, Moj; Fromm, Katharina M.

2014-08-01

A tridentate hydrazone Schiff base ligand, (E)-N";-(2-hydroxybenzylidene)acetohydrazide [HL], and its mixed-ligand Cu(II) complex [CuL(phen)], have been synthesized and characterized by elemental analyses, FT-IR, molar conductivity, UV-Vis spectroscopy. The structure of the complex has been determined by X-ray diffraction. This complex has square pyramidal geometry and the positions around central atom are occupied with donor atoms of Schiff base ligand and two nitrogens of 1,10-phenanthroline. Computational studies of compounds were performed by using DFT calculations. The linear polarizabilities and first hyperpolarizabilities of the studied molecules indicate that these compounds can be good candidates of nonlinear optical materials. It is in accordance with experimental data. In addition, invitro antimicrobial results show that these compounds specially [CuL(phen)] have great potential of antibacterial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes bacteria and antifungal activity against Candida Albicans in comparison to some standard drugs.

Divergent Coordination Chemistry: Parallel Synthesis of [2×2] Iron(II) Grid-Complex Tauto-Conformers.

PubMed

Schäfer, Bernhard; Greisch, Jean-François; Faus, Isabelle; Bodenstein, Tilmann; Šalitroš, Ivan; Fuhr, Olaf; Fink, Karin; Schünemann, Volker; Kappes, Manfred M; Ruben, Mario

2016-08-26

The coordination of iron(II) ions by a homoditopic ligand L with two tridentate chelates leads to the tautomerism-driven emergence of complexity, with isomeric tetramers and trimers as the coordination products. The structures of the two dominant [Fe(II) 4 L4 ](8+) complexes were determined by X-ray diffraction, and the distinctness of the products was confirmed by ion-mobility mass spectrometry. Moreover, these two isomers display contrasting magnetic properties (Fe(II) spin crossover vs. a blocked Fe(II) high-spin state). These results demonstrate how the coordination of a metal ion to a ligand that can undergo tautomerization can increase, at a higher hierarchical level, complexity, here expressed by the formation of isomeric molecular assemblies with distinct physical properties. Such results are of importance for improving our understanding of the emergence of complexity in chemistry and biology. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

A novel extended architecture with 4 6·6 4 topology based on mixed-valence Wells-Dawson arsenotungstate and mixed-ligand Cu(I) units

NASA Astrophysics Data System (ADS)

Tong, Ruizhan; Ren, Xiaoyu; Li, Zuoxi; Liu, Bin; Hu, Huaiming; Xue, Ganglin; Fu, Feng; Wang, Jiwu

2010-09-01

A novel inorganic-organic hybrid compound based on mixed-valence Wells-Dawson arsenotungstate and mixed-ligand Cu(I) units, Cu 8I(imi) 4(bpy) 6(H 2O)[As 2VW 2VW 16VlO 62]·2H 2O ( 1) (bpy=4,4'-bipydine; imi=imidazole), has been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, luminescent spectrum and single crystal X-ray diffraction. Single-crystal X-ray diffraction revealed that four terminal and three bridging oxygen atoms of the Wells-Dawson cluster are coordinated to Cu(I) ions and form an unprecedented hepta-supporting polyoxometalate. The functionalized arsenotungstates are further connected by two kinds of tridentate linkers, Imi-Cu-(bpy)-Cu-(bpy)-Cu-(bpy)-Cu-Imi and Imi-Cu-(bpy)-Cu-(bpy)-Cu-H 2O, to construct a 3D framework with 4 6·6 4 topology. The hybrid material has an intense emission at about 397 nm.

New organophilic kaolin clays based on single-point grafted 3-aminopropyl dimethylethoxysilane.

PubMed

Zaharia, A; Perrin, F-X; Teodorescu, M; Radu, A-L; Iordache, T-V; Florea, A-M; Donescu, D; Sarbu, A

2015-10-14

In this study, the organophilization procedure of kaolin rocks with a monofunctional ethoxysilane- 3 aminopropyl dimethyl ethoxysilane (APMS) is depicted for the first time. The two-step organophilization procedure, including dimethyl sulfoxide intercalation and APMS grafting onto the inner hydroxyl surface of kaolinite (the mineral) layers was tested for three sources of kaolin rocks (KR, KC and KD) with various morphologies and kaolinite compositions. The load of APMS in the kaolinite interlayer space was higher than that of 3-aminopropyl triethoxysilane (APTS) due to the single-point grafting nature of the organophilization reaction. A higher long-distance order of kaolinite layers with low staking was obtained for the APMS, due to a more controllable organiphilization reaction. Last but not least, the solid state (29)Si-NMR tests confirmed the single-point grafting mechanism of APMS, corroborating monodentate fixation on the kaolinite hydroxyl facets, with no contribution to the bidentate or tridentate fixation as observed for APTS.

Synthesis, characterization and anticancer activity of a Cd(II) complex with in situ formation of (E)-1-(5-chloro-2-hydroxy-benzylideneamino)-pyrrolidin-2-one ligand

NASA Astrophysics Data System (ADS)

Huang, Qiu-Ying; Zheng, Ze-Bao; Diao, Yun-Peng

2015-05-01

A new complex of Cd(II) with (E)-1-(5-chloro-2-hydroxybenzylideneamino)-pyrrolidin-2-one [Cd(L)2ṡ2DMF] was synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. Where the HL ligand is formed in situ by the intramolecular nucleophilic substitution of (E)-N‧-(5-chloro-2-hydroxybenzyli-dene)-4-(quinolin-8-yloxy)butanehydrazide (H2L‧). The cadmium(II) ion is hexacoordinated by two tridentate L- ligands and giving a distorted octahedral coordination geometry. A cytotoxicity of [Cd(L)2ṡ2DMF] against liver (SMMC-7721) and cervical (HeLa) cancer cells have been studied. The results revealed that this cadmium(II) complex exhibited an effective and selective anticancer activity against HeLa over SMMC-7721 cell line with IC50 of 1.54 ± 0.25 and 31.02 ± 3.76 μmol/dm-3.

Microchip problems plague DOD

NASA Astrophysics Data System (ADS)

Smith, R. J.

1984-10-01

The major issues in the controversy over the discovery of millions of defective microchips sold to the DOD by the Texas Instruments (TI) corporation are outlined. Defects in the microcircuits are blamed on inadequate testing procedures performed by TI during manufacture, and on inadequate testing procedures used by a subcontractor especially contracted to test the chips. Because the problem persisted over a period of years, defects might be possible in as many as 100 million chips used in a broad range of military applications including the Trident submarine, the B-52, B-1B, F-15, F-111, F-4, A-6, and A-7 aircraft, the Harpoon and HARM missile systems, and the Space Shuttles Discovery and Challenger. It is pointed out that although TI has accepted responsibility for the defective chips, little will be done by the DOD to compel the company to replace them, or to upgrade testing procedures. It is concluded that the serious nature of the problem could renew interest in recommendations for the standardization of military microcircuits.

Future DUNE constraints on EFT

NASA Astrophysics Data System (ADS)

Falkowski, Adam; Grilli di Cortona, Giovanni; Tabrizi, Zahra

2018-04-01

In the near future, fundamental interactions at high-energy scales may be most efficiently studied via precision measurements at low energies. A universal language to assemble and interpret precision measurements is the so-called SMEFT, which is an effective field theory (EFT) where the Standard Model (SM) Lagrangian is extended by higher-dimensional operators. In this paper we investigate the possible impact of the DUNE neutrino experiment on constraining the SMEFT. The unprecedented neutrino flux offers an opportunity to greatly improve the current limits via precision measurements of the trident production and neutrino scattering off electrons and nuclei in the DUNE near detector. We quantify the DUNE sensitivity to dimension-6 operators in the SMEFT Lagrangian, and find that in some cases operators suppressed by an O(30) TeV scale can be probed. We also compare the DUNE reach to that of future experiments involving atomic parity violation and polarization asymmetry in electron scattering, which are sensitive to an overlapping set of SMEFT parameters.

XAFS investigation of polyamidoxime-bound uranyl contests the paradigm from small molecule studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayes, Richard T.; Piechowicz, Marek; Lin, Zekai

In this study, limited resource availability and population growth have motivated interest in harvesting valuable metals from unconventional reserves, but developing selective adsorbents for this task requires structural knowledge of metal binding environments. Amidoxime polymers have been identified as the most promising platform for large-scale extraction of uranium from seawater. However, despite more than 30 years of research, the uranyl coordination environment on these adsorbents has not been positively identified. We report the first XAFS investigation of polyamidoxime-bound uranyl, with EXAFS fits suggesting a cooperative chelating model, rather than the tridentate or η 2 motifs proposed by small molecule andmore » computational studies. Samples exposed to environmental seawater also display a feature consistent with a μ 2-oxo-bridged transition metal in the uranyl coordination sphere, suggesting in situ formation of a specific binding site or mineralization of uranium on the polymer surface. These unexpected findings challenge several long-held assumptions and have significant implications for development of polymer adsorbents with high selectivity.« less

Efficient hydrogenation of organic carbonates, carbamates and formates indicates alternative routes to methanol based on CO2 and CO

NASA Astrophysics Data System (ADS)

Balaraman, Ekambaram; Gunanathan, Chidambaram; Zhang, Jing; Shimon, Linda J. W.; Milstein, David

2011-08-01

Catalytic hydrogenation of organic carbonates, carbamates and formates is of significant interest both conceptually and practically, because these compounds can be produced from CO2 and CO, and their mild hydrogenation can provide alternative, mild approaches to the indirect hydrogenation of CO2 and CO to methanol, an important fuel and synthetic building block. Here, we report for the first time catalytic hydrogenation of organic carbonates to alcohols, and carbamates to alcohols and amines. Unprecedented homogeneously catalysed hydrogenation of organic formates to methanol has also been accomplished. The reactions are efficiently catalysed by dearomatized PNN Ru(II) pincer complexes derived from pyridine- and bipyridine-based tridentate ligands. These atom-economical reactions proceed under neutral, homogeneous conditions, at mild temperatures and under mild hydrogen pressures, and can operate in the absence of solvent with no generation of waste, representing the ultimate ‘green’ reactions. A possible mechanism involves metal-ligand cooperation by aromatization-dearomatization of the heteroaromatic pincer core.

XAFS investigation of polyamidoxime-bound uranyl contests the paradigm from small molecule studies

DOE PAGES

Mayes, Richard T.; Piechowicz, Marek; Lin, Zekai; ...

2015-11-12

In this study, limited resource availability and population growth have motivated interest in harvesting valuable metals from unconventional reserves, but developing selective adsorbents for this task requires structural knowledge of metal binding environments. Amidoxime polymers have been identified as the most promising platform for large-scale extraction of uranium from seawater. However, despite more than 30 years of research, the uranyl coordination environment on these adsorbents has not been positively identified. We report the first XAFS investigation of polyamidoxime-bound uranyl, with EXAFS fits suggesting a cooperative chelating model, rather than the tridentate or η 2 motifs proposed by small molecule andmore » computational studies. Samples exposed to environmental seawater also display a feature consistent with a μ 2-oxo-bridged transition metal in the uranyl coordination sphere, suggesting in situ formation of a specific binding site or mineralization of uranium on the polymer surface. These unexpected findings challenge several long-held assumptions and have significant implications for development of polymer adsorbents with high selectivity.« less

Bis[1-meth­oxy-2,2,2-tris­(pyrazol-1-yl-κN 2)ethane]­nickel(II) bis­(tri­fluoro­methane­sulfonate) methanol disolvate

PubMed Central

Lyubartseva, Ganna; Parkin, Sean; Mallik, Uma Prasad

2013-01-01

In the title salt, [Ni(C12H14N6O)2](CF3SO3)2·2CH3OH, the NiII ion is coordinated by six N atoms from two tridentate 1-meth­oxy-2,2,2-tris­(pyrazol-1-yl)ethane ligands in a distorted octa­hedral geometry. The NiII ion is situated on an inversion centre. The Ni—N distances range from 2.0589 (19) to 2.0757 (19) Å, intra-ligand N—Ni—N angles range from 84.50 (8) to 85.15 (8)°, and adjacent inter-ligand N—Ni—N angles range between 94.85 (8) and 95.50 (8)°. In the crystal, O—H⋯O hydrogen bonds between methanol solvent mol­ecules and tri­fluoro­methane­sulfonate anions are observed. PMID:24098170

Efficient hydrogenation of organic carbonates, carbamates and formates indicates alternative routes to methanol based on CO2 and CO.

PubMed

Balaraman, Ekambaram; Gunanathan, Chidambaram; Zhang, Jing; Shimon, Linda J W; Milstein, David

2011-07-22

Catalytic hydrogenation of organic carbonates, carbamates and formates is of significant interest both conceptually and practically, because these compounds can be produced from CO2 and CO, and their mild hydrogenation can provide alternative, mild approaches to the indirect hydrogenation of CO2 and CO to methanol, an important fuel and synthetic building block. Here, we report for the first time catalytic hydrogenation of organic carbonates to alcohols, and carbamates to alcohols and amines. Unprecedented homogeneously catalysed hydrogenation of organic formates to methanol has also been accomplished. The reactions are efficiently catalysed by dearomatized PNN Ru(II) pincer complexes derived from pyridine- and bipyridine-based tridentate ligands. These atom-economical reactions proceed under neutral, homogeneous conditions, at mild temperatures and under mild hydrogen pressures, and can operate in the absence of solvent with no generation of waste, representing the ultimate 'green' reactions. A possible mechanism involves metal-ligand cooperation by aromatization-dearomatization of the heteroaromatic pincer core.

Trichlorido[(meth­yl{2-[meth­yl(2-pyridyl­meth­yl)amino]eth­yl}amino)acetonitrile]iron(III) methanol hemisolvate

PubMed Central

Nielsen, Anne; McKenzie, Christine J.; Bond, Andrew D.

2009-01-01

The title compound, [FeCl3(C12H18N4)]·0.5CH3OH, contains an FeIII ion in a distorted octa­hedral coordination environment. The neutral N,N′,N′′-tridentate ligand adopts a fac coordination mode, and chloride ligands lie trans to each of the three coordinated N atoms. In the crystal, the complexes form columns extending parallel to the approximate local threefold axes of the FeN3Cl3 octa­hedra, and the columns are arranged so that the uncoordinated nitrile groups align in an anti­parallel manner and the pyridyl rings form offset face-to-face arrangements [inter­planar separations = 2.95 (1) and 3.11 (1) Å; centroid–centroid distances = 5.31 (1) and 4.92 (1) Å]. The methanol solvent mol­ecule is disordered about a twofold rotation axis. PMID:21578169

Synthesis, spectral, thermal and structural characterization of two complexes containing [N-(2-hydroxyethyl)-ethylenediamine] with carboxylate

NASA Astrophysics Data System (ADS)

Aycan, Tuǧba; Paşaoǧlu, Hümeyra

2018-02-01

Compounds based on the [Zn(hydet-en)2].(tpht).(H2O) (1) (tpht=dianion of terephthalic acid, hydet-en=N-(2-hydroxyethyl)ethylenediamine) has been synthesized which is characterized by single crystal X-ray determination, IR and thermal analysis. In 1, the Zinc(II) ion is six-coordinated that sandwiched by two hydet-en ligands which lies each hydeten ligand adopts a tripodal conformation and acts as tridentate ligand, carboxylate is uncoordinated. The coordination monomer is connected by C(13) chains and linear chains are connected by O-H...O H-bonds formed by DA:AD type 4 organization of aqua ligands and tpa2- ions resulting in R44(12 ) synthons to 3D structure. The FT-IR investigation of the complex were performed within the mid-IR region, mainly focusing on the characteristic vibrations of its free state and ligand behaviour in the case of complex formation. Thermal behaviours of 1 were followed using TG, DTA and DTG techniques.

Correlation between the Stereochemistry and Bioactivity in Octahedral Rhodium Prolinato Complexes.

PubMed

Rajaratnam, Rajathees; Martin, Elisabeth K; Dörr, Markus; Harms, Klaus; Casini, Angela; Meggers, Eric

2015-08-17

Controlling the relative and absolute configuration of octahedral metal complexes constitutes a key challenge that needs to be overcome in order to fully exploit the structural properties of octahedral metal complexes for applications in the fields of catalysis, materials sciences, and life sciences. Herein, we describe the application of a proline-based chiral tridentate ligand to decisively control the coordination mode of an octahedral rhodium(III) complex. We demonstrate the mirror-like relationship of synthesized enantiomers and differences between diastereomers. Further, we demonstrate, using the established pyridocarbazole pharmacophore ligand as part of the organometallic complexes, the importance of the relative and absolute stereochemistry at the metal toward chiral environments like protein kinases. Protein kinase profiling and inhibition data confirm that the proline-based enantiopure rhodium(III) complexes, despite having all of the same constitution, differ strongly in their selectivity properties despite their unmistakably mutual origin. Moreover, two exemplary compounds have been shown to induce different toxic effects in an ex vivo rat liver model.

Selective modification of halloysite lumen with octadecylphosphonic acid: new inorganic tubular micelle.

PubMed

Yah, Weng On; Takahara, Atsushi; Lvov, Yuri M

2012-01-25

Selective fatty acid hydrophobization of the inner surface of tubule halloysite clay is demonstrated. Aqueous phosphonic acid was found to bind to alumina sites at the tube lumen and did not bind the tube's outer siloxane surface. The bonding was characterized with solid-state nuclear magnetic resonance ((29)Si, (13)C, (31)P NMR), Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy. NMR and FTIR spectroscopy of selectively modified tubes proved binding of octadecylphosphonic acid within the halloysite lumen through bidentate and tridentate P-O-Al linkage. Selective modification of the halloysite clay lumen creates an inorganic micelle-like architecture with a hydrophobic aliphatic chain core and a hydrophilic silicate shell. An enhanced capacity for adsorption of the modified halloysite toward hydrophobic derivatives of ferrocene was shown. This demonstrates that the different inner and outer surface chemistry of clay nanotubes can be used for selective modification, enabling different applications from water purification to drug immobilization and controlled release. © 2011 American Chemical Society

O2 Activation and Double C-H Oxidation by a Mononuclear Manganese(II) Complex.

PubMed

Deville, Claire; Padamati, Sandeep K; Sundberg, Jonas; McKee, Vickie; Browne, Wesley R; McKenzie, Christine J

2016-01-11

A Mn(II) complex, [Mn(dpeo)2](2+) (dpeo=1,2-di(pyridin-2-yl)ethanone oxime), activates O2, with ensuing stepwise oxidation of the methylene group in the ligands providing an alkoxide and ultimately a ketone group. X-ray crystal-structure analysis of an intermediate homoleptic alkoxide Mn(III) complex shows tridentate binding of the ligand via the two pyridyl groups and the newly installed alkoxide moiety, with the oxime group no longer coordinated. The structure of a Mn(II) complex of the final ketone ligand, cis-[MnBr2(hidpe)2] (hidpe=2-(hydroxyimino)-1,2-di(pyridine-2-yl)ethanone) shows that bidentate oxime/pyridine coordination has been resumed. H2(18)O and (18)O2 labeling experiments suggest that the inserted O atoms originate from two different O2 molecules. The progress of the oxygenation was monitored through changes in the resonance-enhanced Raman bands of the oxime unit. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antioxidant, electrochemical, thermal, antimicrobial and alkane oxidation properties of tridentate Schiff base ligands and their metal complexes

NASA Astrophysics Data System (ADS)

Ceyhan, Gökhan; Çelik, Cumali; Uruş, Serhan; Demirtaş, İbrahim; Elmastaş, Mahfuz; Tümer, Mehmet

2011-10-01

In this study, two Schiff base ligands (HL 1 and HL 2) and their Cu(II), Co(II), Ni(II), Pd(II) and Ru(III) metal complexes were synthesized and characterized by the analytical and spectroscopic methods. Alkane oxidation activities of the metal complexes were studied on cyclohexane as substrate. The ligands and their metal complexes were evaluated for their antimicrobial activity against Corynebacterium xerosis, Bacillus brevis, Bacillus megaterium, Bacillus cereus, Mycobacterium smegmatis, Staphylococcus aureus, Micrococcus luteus and Enterococcus faecalis (as Gram-positive bacteria) and Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Yersinia enterocolitica, Klebsiella fragilis, Saccharomyces cerevisiae, and Candida albicans (as Gram-negative bacteria). The antioxidant properties of the Schiff base ligands were evaluated in a series of in vitro tests: 1,1-diphenyl-2-picrylhydrazyl (DPPH rad ) free radical scavenging and reducing power activity of superoxide anion radical generated non-enzymatic systems. Electrochemical and thermal properties of the compounds were investigated.

Redox interplay of oxo-thio-tungsten centers with sulfur-donor co-ligands.

PubMed

Thomas, Simon; Eagle, Aston A; Sproules, Stephen A; Hill, Jason P; White, Jonathan M; Tiekink, Edward R T; George, Graham N; Young, Charles G

2003-09-22

The oxo-thio-W(VI) complexes TpWOS(S(2)PR(2)-S) and TpWOS(pyS-S) (Tp = hydrotris(3,5-dimethylpyrazol-1-yl)borate, R = OEt, Ph; pyS = pyridine-2-thiolate) have been prepared and characterized by microanalytical, spectroscopic, and structural techniques. Crystals of the 1,2-dichloroethane hemisolvate of TpWOS(S(2)PPh(2)-S) belong to the triclinic space group Ponemacr; with a = 10.732(6) A, b = 16.91(1) A, c = 10.021(4) A, alpha = 104.40(4) degrees, beta = 107.52(3) degrees, gamma = 96.09(5) degrees, V = 1647(1) A(3) for Z = 2. The complex exhibits a distorted octahedral structure featuring a facial tridentate Tp ligand and mutually cis terminal oxo (W-O(1) = 1.712(7) A), terminal thio (W-S(1) = 2.162(3) A), and monodentate dithiophosphinate ligands. X-ray absorption and extended X-ray absorption fine structure results support a related oxo-thio formulation for TpWOS(pyS-S). The complexes are reduced to the corresponding oxo-thio-W(V) anions, [TpWOS(S(2)PR(2)-S)](-) and [TpWOS(pyS-S)](-), which exhibit highly anisotropic EPR spectra. They are oxidized to form the EPR-active (dithio)oxo-W(V) cations, [TpWO(S(3)PR(2)-S,S')](+) and [TpWO(pyS(2)-N,S)](+) (pyS(2) = pyridine-2-dithio). Green [TpWO(pyS(2)-N,S)]BF(4), formed in the reaction of TpWOS(pyS) and NOBF(4), has been isolated and spectroscopically and structurally characterized. Crystals of [TpWO(pyS(2)-N,S)]BF(4) belong to the monoclinic space group Cc with a = 16.007(5) A, b = 14.091(4) A, c = 13.608(4) A, beta = 124.525(4) degrees, V = 2528.8(13) A(3) for Z = 4. The cation exhibits a distorted octahedral structure featuring facial tridentate Tp, terminal oxo (W-O(1) = 1.632(12) A), and bidentate pyridine-2-dithio-N,S (W-S(1) = 2.317(7) A, S(1)-S(2) = 2.037(9) A) ligands. The structures and redox behavior of the complexes are compared and contrasted with those of the related molybdenum complexes, TpMo(VI)OS(S(2)PR(2)-S) and TpMo(IV)O(pyS(2)-N,S) (Hill, J. P.; Laughlin, L. J.; Gable, R. W.; Young, C. G. Inorg. Chem. 1996, 35, 3447).

Geochronology and eruptive history of the Katmai volcanic cluster, Alaska Peninsula

USGS Publications Warehouse

Hildreth, Wes; Lanphere, Marvin A.; Fierstein, Judy

2003-01-01

In the Katmai district of the Alaska Peninsula, K–Ar and 40Ar/39Ar ages have been determined for a dozen andesite–dacite stratocones on the arc front and for 11 rear-arc volcanoes, 10 of which are monogenetic. Tied to mapping and stratigraphic studies, our dating emphasized proximal basal lavas that rest on basement rocks, in order to estimate ages of inception of each polygenetic cone. Oldest among arc-front cones is Alagogshak Volcano (690–43 ka), succeeded in the Holocene by the active Mount Martin cone. Mount Mageik consists of four overlapping subedifices, basal lavas of which give ages of 93, 71, and 59 ka, and Holocene. The three small prehistoric cones of Trident Volcano yield ages of 143, 101–58, and 44 ka. Falling Mountain and Mount Cerberus, dacite domes near the 1912 Novarupta vent, are related compositionally to the Trident group and give ages of 70 ka and 114 ka. Mount Katmai, which underwent caldera collapse in 1912, consists of two subedifices that overlapped in space and time, and is the only arc-front center here to include basalt and rhyolite; one cone began by 90 ka, the other by 47 ka. Snowy Mountain also consists of two contiguous cones, which started around 200 and 171 ka, respectively, the younger remaining active into the Holocene. Devils Desk, the only mafic cone on the arc front, was short-lived at about 245 ka. In the rear-arc, (1) Mount Griggs produced mafic-to-silicic andesite in several episodes between 292 ka and the Holocene; (2) the Savonoski River cluster includes a Pliocene dacite dome and five small mafic cones (390–88 ka); (3) Gertrude Creek cone (49.8% SiO2) yields an age of 500 ka; and (4) the Saddlehorn Creek cluster includes five Pliocene basalt-to-andesite remnants. Eruptive volumes were reconstructed, permitting estimates of average eruption rates for edifice lifetimes. Since the mid Pleistocene, total volume erupted along the arc front here is 210±47 km3 and in the rear-arc 39±6 km3, of which Mount Griggs alone accounts for 35±5 km3. Most productive has been Mount Katmai at 70±18 km3, yielding a rate of ∼1 km3/kyr, followed by Mount Mageik (0.33 km3/kyr) and Mount Griggs (0.3 km3/kyr since 50 ka).  

Synthesis, structure elucidation, biological screening, molecular modeling and DNA binding of some Cu(II) chelates incorporating imines derived from amino acids

NASA Astrophysics Data System (ADS)

Abdel-Rahman, Laila H.; Abu-Dief, Ahmed M.; Ismael, Mohammed; Mohamed, Mounir A. A.; Hashem, Nahla Ali

2016-01-01

Three tridentate Schiff bases amino acids were prepared by direct condensation of 3-methoxysalicylaldehyde (MS) or 4-diethylaminosalicylaldehyde (DS) with α-amino acid ligands [L-phenylalanine (P), L-histidine (H) and DL-tryptophan (T)]. The prepared Schiff bases amino acids were investigated by melting points, elemental analysis, 1HNMR and 13CNMR, IR, UV-Vis spectra, conductivity and magnetic measurements analyses. Subsequently, copper was introduced and Cu(II) complexes formed. These complexes were analyzed by thermal and elemental analyses and further investigated by FT-IR and UV/Vis spectroscopies. The experimental results indicating that all Cu(II) complexes contain hydrated water molecules (except DSPCu complex) and don't contain coordinated water molecules. The kinetic and thermal parameters were extracted from the thermal data using Coast and Redfern method. The molar conductance values of the Schiff base amino acid ligands and their Cu(II) complexes were relatively low, showing that these compounds have non-electrolytic nature. Magnetic susceptibility measurements showed the diamagnetic nature of the Schiff base amino acid ligands and paramagnetic nature of their complexes. Additionally, a spectrophotometric method was determined to extract their stability constants. It was found that the complexes possess 1:2 (M:L) stoichiometry. The results suggested that 3-methoxysalicylaldehyde and 4-diethylaminosalicylaldehyde amino acid Schiff bases behave as monobasic tridentate ONO ligands and coordinate Cu(II) ions in octahedral geometry according to the general formula [Cu(HL)2]·nH2O. To further understanding the structural and electronic properties of these complexes, Density Functional Theory (DFT) calculations were employed and provided a satisfactory description. The optimized structures of MST Schiff base ligand and its complex were calculated using DFT. The antimicrobial activity of the Schiff base ligands and their complexes were screened against some types of bacteria such as Bacillus subtilis (+ve), Escherichia coli (-ve) and Micrococcus luteus (+ve) and some types of fungi such as Asperagillus niger, Candida glabrata and Saccharomyces cerevisiae. The results of these studies indicated that the metal complexes exhibit a stronger antibacterial and antifungal efficiency compared to their corresponding ligands. The complexes were screened for antiviral activity against a panel of DNA and RNA viruses. Minimum cytotoxic and minimum virus inhibitory concentrations of these complexes were determined. The mode of interaction between complexes and CT-DNA was monitored using absorption spectra, viscosity measurements and gel electrophoreses.

Electronic and geometric structures of Au30 clusters: a network of 2e-superatom Au cores protected by tridentate protecting motifs with u3-S

NASA Astrophysics Data System (ADS)

Tian, Zhimei; Cheng, Longjiu

2015-12-01

Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S21P6 configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters.Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S21P6 configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters. Electronic supplementary information (ESI) available: The AdNDP localized natural bonding orbitals of the valence shells of the Au30S(SH)18 cluster. IR spectra, absorption spectra and coordinates of Au30S(SCH3)18, Au30(SCH3)18 and Au30S2(SCH3)18 clusters. See DOI: 10.1039/c5nr05020k

Achondroplasia among ancient populations of mesoamerica and South America: Iconographic and Archaeological Evidence.

PubMed

Rodríguez, Carlos A; Isaza, Carolina; Pachajoa, Harry

2012-07-01

Achondroplasia is the most frequent form of short-limb dwarfism. Affected individuals exhibit short stature caused by rhizomelic shortening of the limbs, characteristic facies with frontal bossing and mid-face hypoplasia, genu varum, and trident hand. Although the etiology of this disease was reported in 1994, evidence of this disease in ancient populations has been found in populations of ancient Egypt (2500 BC) and it has been documented in ancient American populations. To analyze the presence of individuals with achondroplasia in the Mayan state society of Mexico and Guatemala, during the Classical (100- 950 AC ) and Post-Classical (950 - 1519 AC ) periods; likewise, in the hierarchical-chieftain society of Tumaco-la Tolita (300 BC - 600 AC ) from the Colombia-Ecuador Pacific coast, and the Moche state society (100 - 600 AC ) from the northern coast of Peru. Iconographic and clinical-morphological studies of some of the most important artistic representations of individuals of short stature in these three cultures. We present the hypothesis that the individuals with short stature were somehow associated with the political and religious power elite.

Achondroplasia among ancient populations of mesoamerica and South America: Iconographic and Archaeological Evidence.

PubMed Central

Isaza, Carolina; Pachajoa, Harry

2012-01-01

Introduction: Achondroplasia is the most frequent form of short-limb dwarfism. Affected individuals exhibit short stature caused by rhizomelic shortening of the limbs, characteristic facies with frontal bossing and mid-face hypoplasia, genu varum, and trident hand. Although the etiology of this disease was reported in 1994, evidence of this disease in ancient populations has been found in populations of ancient Egypt (2500 BC) and it has been documented in ancient American populations. Objective: To analyze the presence of individuals with achondroplasia in the Mayan state society of Mexico and Guatemala, during the Classical (100- 950 AC ) and Post-Classical (950 - 1519 AC ) periods; likewise, in the hierarchical-chieftain society of Tumaco-la Tolita (300 BC - 600 AC ) from the Colombia-Ecuador Pacific coast, and the Moche state society (100 - 600 AC ) from the northern coast of Peru. Methods: Iconographic and clinical-morphological studies of some of the most important artistic representations of individuals of short stature in these three cultures. Conclusion: We present the hypothesis that the individuals with short stature were somehow associated with the political and religious power elite. PMID:24893194

Synthesis and crystal structure of new copper(II) metal complex: Noncovalent interactions and electrical conductance properties

NASA Astrophysics Data System (ADS)

Pathak, Sudipta; Chakraborty, Koushik; Ghosh, Surajit; Roy, Kunal; Jana, Barnali; Konar, Saugata

2018-01-01

[Cu(pydc)(apyz)(H2O)2] (1) (where pydcH2 = pyridine-2,6-dicarboxylic acid; apyz = 2- aminopyrazine) has been synthesized and characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction techniques. Crystallographic analysis revealed that complex 1 has distorted octahedral geometry with pydcH2 coordinated as tridentate ligands to metal ion through two oxygen atoms of each carboxylate group, nitrogen atom of the pyridine ring and the auxiliary ligand pyrazine nitrogen atom form basal plane and apical positions are occupied by two oxygen atoms of water molecules. In addition, the coordination compounds are connected by a variety of non covalent interactions like OH … π, lone pair … π, π … π and hydrogen bonds. The evaluation of these noncovalent interactions is useful for rationalizing their influence in the crystal packing. In addition, electrical current measured at room temperature on thin film before and after annealed is in the order of 229 μA and 246 μA respectively with bias voltage 1 V.

Distorted tetrahedral nickel-nitrosyl complexes: spectroscopic characterization and electronic structure.

PubMed

Soma, Shoko; Van Stappen, Casey; Kiss, Mercedesz; Szilagyi, Robert K; Lehnert, Nicolai; Fujisawa, Kiyoshi

2016-09-01

The linear nickel-nitrosyl complex [Ni(NO)(L3)] supported by a highly hindered tridentate nitrogen-based ligand, hydrotris(3-tertiary butyl-5-isopropyl-1-pyrazolyl)borate (denoted as L3), was prepared by the reaction of the potassium salt of the ligand with the nickel-nitrosyl precursor [Ni(NO)(Br)(PPh 3 ) 2 ]. The obtained nitrosyl complexes as well as the corresponding chlorido complexes [Ni(NO)(Cl)(PPh 3 ) 2 ] and [Ni(Cl)(L3)] were characterized by X-ray crystallography and different spectroscopic methods including IR/far-IR, UV-Vis, NMR, and multi-edge X-ray absorption spectroscopy at the Ni K-, Ni L-, Cl K-, and P K-edges. For comparative electronic structure analysis we also performed DFT calculations to further elucidate the electronic structure of [Ni(NO)(L3)]. These results provide the nickel oxidation state and the character of the Ni-NO bond. The complex [Ni(NO)(L3)] is best described as [Ni (II) (NO (-) )(L3)], and the spectroscopic results indicate that the phosphane complexes have a similar [Ni (II) (NO (-) )(X)(PPh 3 ) 2 ] ground state.

Achondroplasia: Current Options and Future Perspective.

PubMed

Bouali, Houda; Latrech, Hanane

2015-06-01

Achondroplasia is a human bone genetic disorder of the growth plate and is the most common form of inherited disproportionate short stature. It is inherited as an autosomal dominant disease with essentially complete penetrance. Of these most have the same point mutation in the gene for fibroblast growth factor receptor 3 (FGFR3) which is a negative regulator of bone growth. The clinical and radiological features of achondroplasia can easily be identified; they include disproportionate short stature with rhizomelic shortening, macrocephaly with frontal bossing, midface hypoplasia, lumbar hyperlordosis, and a trident hand configuration. The majority of achondroplasts have a normal intelligence, but many social and medical complications may compromise a full and productive life. Some of them have serious health consequences related to hydrocephalus, craniocervical junction compression, or upper-airway obstruction. In this article, we discuss a number of treatments from the surgical limb lengthening approach and the Recombinant Growth Hormone (rhGH) treatment, to future treatments, which include the Natriuretic Peptide C-type (CNP). The discussion is a comparative study of the complications and drawbacks of various experiments using numerous strategies.

Crystal structure, magnetism, and luminescent properties of two isostructural pcu MOFs based on a triangular ligand

NASA Astrophysics Data System (ADS)

Yan, Pen-Ji; Yao, Xiao-Qiang; Xie, Hua; Xiao, Guo-Bin; Liu, Jia-Cheng; Xu, Xin-Jian

2018-05-01

Two isomorphous metal-organic frameworks, {[M(TIPA) (btec)½]H2O}n, [M = Co (1) or Zn (2)] were synthesized hydrothermally based on a semi-rigid N-center triangular ligand TIPA, where TIPA = tris(4-(1H-imidazol-1-yl)-phenyl)amine, H4btec = 1,2,4,5-benzenetetracarboxylic acid. Single crystal structural analyses show that complexes 1 and 2 are isostructural and both feature a twofold interpenetrated pcu topology. In 1 and 2, the btec4- ligand adopting μ2-η2:η1 and μ1-η1:η0 coordination modes connect adjacent dinuclear Co/Zn units to form a 1D straight polymeric chain. Then these chains arranged in parallel/parallel fashion were further extended to a 3D network by exo-tridentate ligand TIPA with μ2-κ2N:N‧ coordination mode. The magnetic property of 1 and the luminescent property of 2 were investigated. Furthermore, the structure and spectroscopic property of 2 were further investigated by DFT and TD-DFT calculations.

Synthesis, spectroscopic, thermal, voltammetric studies and biological activity of crystalline complexes of pyridine-2,6-dicarboxylic acid and 8-hydroxyquinoline

NASA Astrophysics Data System (ADS)

Çolak, Alper Tolga; Çolak, Ferdağ; Yeşilel, Okan Zafer; Büyükgüngör, Orhan

2009-11-01

Two new compounds (8-H 2Q) 2[M(dipic) 2]·6H 2O (M = Co ( 1) and Ni ( 2), 8-HQ = 8-hydroxyquinoline, dipic = dipicolinate) have been prepared and characterized by elemental analysis, spectral (IR and UV-vis), thermal analyses, magnetic measurements and single-crystal X-ray diffraction techniques. Both 1 and 2 consist two 8-hydroxyquinolinium cations, one bis(dipicolinate)M(II) anion [M = Co(II), Ni(II)] and six uncoordinated water molecules. Both 1 and 2 crystallize in the monoclinic space group C2/c. In the compounds anion, each dipic ligand simultaneously exhibits tridentate coordination modes through N atom of pyridine ring and oxygen atoms of the carboxylate groups. The crystal packing of 1 and 2 is a composite of intermolecular hydrogen bonding and C-O⋯π interactions. The in vitro antibacterial and antifungal activities of 1 and 2 were evaluated by the agar well diffusion method by MIC tests. Both new compounds showed the same antimicrobial activity against Gram-positive bacteria and yeast and fungi expect Gram-negative bacteria.

Synthesis, spectral, thermal and optical properties of Schiff-base complexes derived from 2(E)-2-((z)-4-hydroxypent-3-en-2-ylideneamino)-5-guanidinopentanoic acid and acetylacetone

NASA Astrophysics Data System (ADS)

Hosny, Nasser Mohammed; Hussien, Mostafa A.; Radwan, Fatima M.; Nawar, Nagwa

2017-09-01

New metal complexes derived from the in situ reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H2L) resulted from the condensation of 2-amino-5-guanidinopentanoic acid (arginine) and acetylacetone have been synthesized. The resulting complexes have been characterized by, elemental analyses, ES-MS, IR, Raman spectra, UV-Vis., 1HNMR, ESR, thermal analyses (TGA and DTG) and magnetic measurements. The results showed that, The Schiff-base ligand acts as bi-negative tridentate coordinating via azomethine nitrogen, enolic carbonyl oxygen and carboxylate oxygen after displacement of hydrogen. The thermodynamic parameters E∗, ΔH, ΔG and ΔS of the isolated complexes have been calculated. The optical band gap (Eg) values of Cu, Co, Ni and Zn were found to be 3.3, 3.4, 3.7 and 4.3 eV, respectively, arising from direct transitions. Optical band gap measurements indicate the semi-conductivity nature of these complexes.

Convergent Geometry Foam Buffered Direct Drive Experiments*

NASA Astrophysics Data System (ADS)

Watt, R. G.; Wilson, D. C.; Hollis, R. V.; Gobby, P. L.; Chrien, R. E.; Mason, R. J.; Kopp, R. A.; Willi, O.; Iwase, A.; Barringer, L. H.; Gaillard, R.; Kalantar, D. H.; Lerche, R. A.; MacGowan, B.; Nelson, M.; Phillips, T.; Knauer, J. P.; McKenty, P. W.

1996-11-01

A serious concern for directly driven ICF implosions is the asymmetry imparted to the capsule by laser drive non-uniformities, particularly the ``early time imprint'' remaining despite the use of random phase plates and smoothing with spectral dispersion. The use of a foam buffer has been proposed as a means to reduce this imprint. Two types of convergent geometry tests of the technique to correct static nonuniformities have been studied to date; cylindrical implosions at the Trident and Vulcan lasers, and spherical implosions at the NOVA laser, all using 527 nm laser drive. Cylindrical implosions used end on x-ray backlighter imaging of inner surface disruption due an intentional hole in the drive footprint, using 50 mg/cc acyrlate foam with a thin Au preheat layer. Spherical implosions used 50 mg/cc polystyrene foam plus Au to study yield and imploded core symmetry of capsules with and without a foam buffer, in comparison to ``clean 1D'' calculations. For thick enough layers, all cases showed improvement. Details of the experiments and theoretical unpinnings will be shown. *Work performed under US DOE Contract No. W-7405-Eng-36.

Controlled Lateral Positioning of Microparticles Inside Droplets Using Acoustophoresis.

PubMed

Fornell, Anna; Nilsson, Johan; Jonsson, Linus; Periyannan Rajeswari, Prem Kumar; Joensson, Haakan N; Tenje, Maria

2015-10-20

In this paper, we utilize bulk acoustic waves to control the position of microparticles inside droplets in two-phase microfluidic systems and demonstrate a method to enrich the microparticles. In droplet microfluidics, different unit operations are combined and integrated on-chip to miniaturize complex biochemical assays. We present a droplet unit operation capable of controlling the position of microparticles during a trident shaped droplet split. An acoustic standing wave field is generated in the microchannel, and the acoustic forces direct the encapsulated microparticles to the center of the droplets. The method is generic, requires no labeling of the microparticles, and is operated in a noncontact fashion. It was possible to achieve 2+-fold enrichment of polystyrene beads (5 μm in diameter) in the center daughter droplet with an average recovery of 89% of the beads. Red blood cells were also successfully manipulated inside droplets. These results show the possibility to use acoustophoresis in two-phase systems to enrich microparticles and open up the possibility for new droplet-based assays that are not performed today.

A new species of Stilestrongylus (Nematoda, Heligmonellidae) from the Atlantic Forest of Misiones, Argentina, parasitic in Euryoryzomys russatus (Cricetidae, Sigmodontinae).

PubMed

Panisse, Guillermo; Digiani, María Celina

2018-04-01

A new species of Heligmonellidae (Trichostrongylina, Heligmosomoidea), Stilestrongylus kaaguyporai n. sp. is described from the small intestine of Euryoryzomys russatus (Rodentia, Cricetidae, Sigmodontinae) from the Argentine Atlantic Forest, in the Misiones province. The new species was found at Campo Anexo Manuel Belgrano, Reserva de Vida Silvestre Urugua-í and Parque Provincial Urugua-í, with a prevalence of 73% in 15 hosts examined. Stilestrongylus includes 24 Neotropical species, all parasitic in rodents, mostly Sigmodontinae. Stilestrongylus kaaguyporai n. sp. can be differentiated from its congeners by the following characters: caudal bursa dissymmetrical with right lobe larger and pattern of type1-4 in both lobes, rays 6 not forming a lateral trident with rays 4 and 5, rays 8 with dissymmetrical pathway, genital cone hypertrophied with a conspicuous hood-like projection and females with a marked dorso-ventral torsion of the posterior end. This report is the second record of a Stilestrongylus species in E. russatus, increasing to nine the number of parasitic species known from this host.

An unusual case of Y-shaped right renal vein.

PubMed

Lavy, M; Martin, L; Eouzan, D; Turco, C; Heyd, B; Mantion, G; Parratte, B; Tatu, L

2015-01-01

Vascular renal anomalies are frequent, multiple and well described and result from errors in vessel embryogenesis between the 6th and 10th week of gestation. Historically, variations are described in anatomic dissection and currently mostly in image interpretation. We report an anatomic variation concerning the right renal vein which, to our knowledge, has never been described in the literature either by dissection or by radiological examination. This variation was discovered during the routine dissection of an embalmed male body. It consists of a Y-shaped right renal vein and is associated with multiple retroperitoneal variations: a bilateral accessory renal artery, a trident ending of the right renal artery and a left testicular vein variation. Venous and arterial renal anatomy and its variations are fundamentally important in renal surgery, especially concerning living donor renal grafts. These variations may be diagnosed thanks to injected tomodensitometry which has a good sensitivity and specificity for anomalies. Preoperative diagnosis of an anatomic vascular renal variation may reduce morbidity during surgery, which is why precise examination of injected tomography should be mandatory.

Geologic strip map along the Hines Creek Fault showing evidence for Cenozoic displacement in the western Mount Hayes and northeastern Healy quadrangles, eastern Alaska Range, Alaska

USGS Publications Warehouse

Nokleberg, Warren J.; Aleinikoff, John N.; Bundtzen, Thomas K.; Hanshaw, Maiana N.

2013-01-01

Geologic mapping of the Hines Creek Fault and the adjacent Trident Glacier and McGinnis Glacier Faults to the north in the eastern Alaska Range, Alaska, reveals that these faults were active during the Cenozoic. Previously, the Hines Creek Fault, which is considered to be part of the strike-slip Denali Fault system (Ridgway and others, 2002; Nokleberg and Richter, 2007), was interpreted to have been welded shut during the intrusion of the Upper Cretaceous Buchanan Creek pluton (Wahrhaftig and others, 1975; Gilbert, 1977; Sherwood and Craddock, 1979; Csejtey and others, 1992). Our geologic mapping along the west- to west-northwest-striking Hines Creek Fault in the northeastern Healy quadrangle and central to northwestern Mount Hayes quadrangle reveals that (1) the Buchanan Creek pluton is truncated by the Hines Creek Fault and (2) a tectonic collage of fault-bounded slices of various granitic plutons, metagabbro, metabasalt, and sedimentary rock of the Pingston terrane occurs south of the Hines Creek Fault.

Synthesis, spectral characterization and DNA binding of Schiff-base metal complexes derived from 2-amino-3-hydroxyprobanoic acid and acetylacetone

NASA Astrophysics Data System (ADS)

Hosny, Nasser Mohammed; Hussien, Mostafa A.; Radwan, Fatima M.; Nawar, Nagwa

2014-11-01

Four new metal complexes derived from the reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H3L) resulted from the condensation of the amino acid 2-amino-3-hydroxyprobanoic acid (serine) and acetylacetone have been synthesized and characterized by, elemental analyses, ES-MS, IR, UV-Vis., 1H NMR, 13C NMR, ESR, thermal analyses (TGA and DTG) and magnetic measurements. The results showed that the Schiff-base ligand acts as bi-negative tridentate through the azomethine nitrogen, the deprotonated carboxylate oxygen and the enolic carbonyl oxygen. The optical band gaps measurements indicated the semi-conducting nature of these complexes. Molecular docking was used to predict the binding between the Schiff base ligand with the receptor of prostate cancer mutant H874Y. The interactions between the Cu(II) complex and calf thymus DNA (CT-DNA) have been studied by UV spectra. The results confirm that the Cu(II) complex binds to CT-DNA in an intercalative mode.

Immobilization of PMIDA on Fe3O4 magnetic nanoparticles surface: Mechanism of bonding

NASA Astrophysics Data System (ADS)

Demin, Alexander M.; Mekhaev, Alexander V.; Esin, Alexander A.; Kuznetsov, Dmitry K.; Zelenovskiy, Pavel S.; Shur, Vladimir Ya.; Krasnov, Victor P.

2018-05-01

The mechanism of N-phosphonomethyl iminodiacetic acid (PMIDA) binding with the Fe3O4 magnetic nanoparticle (MNPs) surface by Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetry was comprehensive studied. To study of microstructure, size and core structure of synthesized nanoparticles the scanning electron microscopy, X-ray diffraction analysis and Raman spectroscopy were carried out. A new scheme for the tridentate bonding of the phosphonomethyl derivative with surface Fe atoms involving unequal Psbnd Osbnd Fe bonds was proposed. The mechanism of thermal decomposition of PMIDA molecules on the MNP surface was studied using a thermogravimetric analyzer combined with infrared spectrometer. It was shown for the first time that during the thermal treatment of phosphonomethyl-modified MNPs, PMIDA molecules are not desorbed from the surface of MNPs but gradually decompose. We believe that obtained in this work data will be useful for a deeper understanding of the mechanisms of phosphonic acid derivatives interaction with MNPs, as well as in the design of new biomedical materials, in which the conjugation of biomolecules with carboxyl groups of PMIDA-modified MNPs is assumed.

Crystal structure of ammonium/potassium trans-bis­(N-methyl­iminodi­acetato-κ3 O,N,O′)chromate(III) from synchrotron data

PubMed Central

Moon, Dohyun; Choi, Jong-Ha

2016-01-01

The structure of the title compound, [(NH4)0.8K0.2][Cr(C5H7NO4)2] (C5H7NO4 is methyl­iminodi­acetate; mida), has been determined from synchrotron data. The CrIII atom is located on a centre of symmetry and is coordinated by two N atoms and four O atoms of two facially arranged tridentate mida ligands, displaying a slightly distorted octa­hedral coordination environment. The Cr—N and mean Cr—O bond lengths are 2.0792 (14) and 1.958 (14) Å, respectively. The cation site is located on a twofold rotation axis and shows occupational disorder, being occupied by ammonium and potassium cations in a 0.8:0.2 ratio. In the crystal, inter­molecular hydrogen bonds involving the N—H groups of the ammonium cation as donor and the two non-coordinating O atoms of the carboxyl­ate group as acceptor groups consolidate the three-dimensional packing. PMID:27536411

Cyclometalated products of [(COE)(2)RhCl](2) and 1,3-(RSCH(2))(2)C(6)H(4) (R = (t)Bu, (i)Pr) Are Dimeric. Synthesis, molecular structures, and solution dynamics of [mu-ClRh(H)(RSCH(2))(2)C(6)H(3)-2,6](2).

PubMed

Evans, Daniel R; Huang, Mingsheng; Seganish, W Michael; Chege, Esther W; Lam, Yiu-Fai; Fettinger, James C; Williams, Tracie L

2002-05-20

Two tridentate thioether pincer ligands, 1,3-(RSCH(2))(2)C(6)H(4) (R = (t)()Bu, 1a; R = (i)()Pr, 1b) underwent cyclometalation using [(COE)(2)RhCl](2) in air/moisture-free benzene at room temperature. The resultant complexes, [mu-ClRh(H)(RSCH(2))(2)C(6)H(3)-2,6](2) (R = (t)Bu, 2a; R = (i)Pr, 2b) are dimeric both in the solid state and in solution. A battery of variable-temperature one- and two-dimensional (1)H NMR experiments showed conclusively that both complexes undergo dynamic exchange in solution. Exchange between two dimeric diastereomers of 2a in solution occurred via rotation about the Rh-C(ipso) bond. The dynamic exchange of 2b was significantly more complex as an additional exchange mechanism, sulfur inversion, occurred, which resulted in the exchange between several diastereomers in solution.

Dark matter contribution to b → sμ+μ- anomaly in local U(1) Lμ -Lτ model

NASA Astrophysics Data System (ADS)

Baek, Seungwon

2018-06-01

We propose a local U(1) Lμ -Lτ model to explain b → sμ+μ- anomaly observed at the LHCb and Belle experiments. The model also has a natural dark matter candidate N. We introduce SU(2)L-doublet colored scalar q ˜ to mediate b → s transition at one-loop level. The U(1) Lμ -Lτ gauge symmetry is broken spontaneously by the scalar S. All the new particles are charged under U(1) Lμ -Lτ. We can obtain C9μ , NP ∼ - 1 to solve the b → sμ+μ- anomaly and can explain the correct dark matter relic density of the universe, ΩDMh2 ≈ 0.12, simultaneously, while evading constraints from electroweak precision tests, neutrino trident experiments and other quark flavor-changing loop processes such as b → sγ and Bs -B‾s mixing. Our model can be tested by searching for Z‧ and new colored scalar at the LHC and B →K* ν ν ‾ process at Belle-II.

Mössbauer and electronic spectral characterization of homo-bimetallic Fe(III) complexes of unsymmetrical [N10] and [N12] macrocyclic ligands.

PubMed

Siddiqi, Zafar Ahmad; Arif, Razia; Kumar, Sarvendra; Khalid, Mohd

2008-10-01

The homo-bimetallic complexes of stoichiometry Fe2(L)ClO4(ClO4)2 where L are novel unsymmetrical [N10] (L1.2HClO4) and [N12] (L2.2HClO4) macrocyclic ligands, have been prepared. The ligands were obtained from an in situ capping reaction of the reactive substrate, N,N'-bis(N-ethylaniline)hydrazine-1,2-diimine with a mixture of aniline or 1,3-diaminopropane and HCHO in presence of HClO4. The compounds have been characterized by elemental analyses, conductometric, IR, FAB-mass and electronic spectral studies. IR data of complexes suggest coordination from unsymmetrical aza sites as a tridentate (N,N,N) or tetradentate (N,N,N,N) ligand. mu(eff) values of the complexes suggest presence of antiferromagnetically coupled (Fe3+-Fe3+=S5/2-S5/2) spin exchange. Mössbauer parameters of the complexes support (+/-3/2)-->(+/-1/2) nuclear transition in high-spin configurations of Fe(III) nuclei of the homo-bimetallic complexes with the presence of Kramer's double degeneracy.

Synthesis, structural studies and antimicrobial activity of N'-((2Z, 3E)-3-(hydroxyimino)butan-2-ylidene)-2-phenylacetohydrazide and its Co(II), Ni(II) complexes

NASA Astrophysics Data System (ADS)

Karadeniz, Şeyma; Ataol, Cigdem Yuksektepe; Şahin, Onur; İdil, Önder; Bati, Hümeyra

2018-06-01

A new aroylhydrazoneoxime, N'-((2Z, 3E)-3-(hydroxyimino)butan-2-ylidene)-2-phenylacetohydrazide ligand (LH2) and its Ni(II) and Co(II) complexes, have been synthesized and characterized by elemental and thermal analyses, IR and UV-vis spectroscopy, magnetic moment and X-ray diffraction. The antimicrobial activities of these compounds were tested by using minimal inhibitory concentration method (MIC). The ligand-containing aroylhydrazone and oxime groups and its Ni complex crystallize in the triclinic system and P 1 - space group, while its Co complex crystallizes in the monoclinic system and the C 2/c space group. X-ray results show that the ligand in the keto form is transformed into enolic form when it forms coordination. From elemental analysis data, the stoichiometry of Co(II) complex was found to be 1:2 (metal/ligand), but 1:1 for Ni(II). IR spectra indicate that the ligand acts as monoanionic NNO- tridentate and coordination takes place form through the oxime nitrogen, imine nitrogen, and enolate oxygen atoms.

Surface complexation model for multisite adsorption of copper(II) onto kaolinite

NASA Astrophysics Data System (ADS)

Peacock, Caroline L.; Sherman, David M.

2005-08-01

We measured the adsorption of Cu(II) onto kaolinite from pH 3-7 at constant ionic strength. EXAFS spectra show that Cu(II) adsorbs as (CuO 4H n) n-6 and binuclear (Cu 2O 6H n) n-8 inner-sphere complexes on variable-charge ≡AlOH sites and as Cu 2+ on ion exchangeable ≡X-H + sites. Sorption isotherms and EXAFS spectra show that surface precipitates have not formed at least up to pH 6.5. Inner-sphere complexes are bound to the kaolinite surface by corner-sharing with two or three edge-sharing Al(O,OH) 6 polyhedra. Our interpretation of the EXAFS data are supported by ab initio (density functional theory) geometries of analog clusters simulating Cu complexes on the {110} and {010} crystal edges and at the ditrigonal cavity sites on the {001}. Having identified the bidentate (≡AlOH) 2Cu(OH) 20, tridentate (≡Al 3O(OH) 2)Cu 2(OH) 30 and ≡X-Cu 2+ surface complexes, the experimental copper(II) adsorption data can be fit to the reactions

Coordination modes of multidentate ligands in fac-[Re(CO)(3)(polyaminocarboxylate)] analogues of (99m)Tc radiopharmaceuticals. dependence on aqueous solution reaction conditions.

PubMed

Lipowska, Malgorzata; He, Haiyang; Xu, Xiaolong; Taylor, Andrew T; Marzilli, Patricia A; Marzilli, Luigi G

2010-04-05

We study Re analogues of (99m)Tc renal agents to interpret previous results at the (99m)Tc tracer level. The relative propensities of amine donors versus carboxylate oxygen donors of four L = polyaminocarboxylate ligands to coordinate in fac-[Re(I)(CO)(3)L](n) complexes were assessed by examining the reaction of fac-[Re(I)(CO)(3)(H(2)O)(3)](+) under conditions differing in acidity and temperature. All four L [N,N-bis-(2-aminoethyl)glycine (DTGH), N,N-ethylenediaminediacetic acid, diethylenetriamine-N-malonic acid, and diethylenetriamine-N-acetic acid] can coordinate as tridentate ligands while creating a dangling chain terminated in a carboxyl group. Dangling carboxyl groups facilitate renal clearance in fac-[(99m)Tc(I)(CO)(3)L](n) agents. Under neutral conditions, the four ligands each gave two fac-[Re(I)(CO)(3)L](n) products with HPLC traces correlating well with known traces of the fac-[(99m)Tc(I)(CO)(3)L](n) mixtures. Such mixtures are common in renal agents because the needed dangling carboxyl group can compete for a coordination site. However, the HPLC separations needed to assess the biodistribution of a single tracer are impractical in a clinical setting. One goal in investigating this Re chemistry is to identify conditions for avoiding this problem of mixtures in preparations of fac-[(99m)Tc(I)(CO)(3)L](n) renal tracers. After separation and isolation of the fac-[Re(I)(CO)(3)L](n) products, NMR analysis of all products and single crystal X-ray crystallographic analysis of both DTGH products, as well as one product each from the other L, allowed us to establish coordination mode unambiguously. The product favored in acidic conditions has a dangling amine chain and more bound oxygen. The product favored in basic conditions has a dangling carboxyl chain and more bound nitrogen. At the elevated temperatures used for simulating tracer preparation, equilibration was facile (ca. 1 h or less), allowing selective formation of one product by utilizing acidic or basic conditions. The results of this fundamental study offer protocols and guidance useful for the design and preparation of fac-[(99m)Tc(I)(CO)(3)L](n) agents consisting of a single tracer.

Rhodium mediated bond activation: from synthesis to catalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Hung-An

Recently, our lab has developed monoanionic tridentate ligand, To R, showing the corresponding coordination chemistry and catalyst reactivity of magnesium, zirconium, zinc and iridium complexes. This thesis details synthetic chemistry, structural study and catalytic reactivity of the To R-supported rhodium compounds. Tl[To R] has been proved to be a superior ligand transfer agent for synthesizing rhodium complexes. The salt metathesis route of Tl[To M] with [Rh(μ-Cl)(CO)] 2 and [Rh(μ- Cl)(COE)] 2 gives To MRh(CO) 2 (2.2) and To MRhH(β 3-C 8H 13) (3.1) respectively while Tl[To M] with [Rh(μ-Cl)(CO)] 2 affords To PRh(CO) 2 (2.3). 2.2 reacts with both strongmore » and weak electrophiles, resulting in the oxazoline N-attacked and the metal center-attacked compounds correspondingly. Using one of the metal center-attacked electrophiles, 2.3 was demonstrated to give high diastereoselectivity. Parallel to COE allylic C-H activation complex 3.1, the propene and allylbenzene allylic C-H activation products have also been synthesized. The subsequent functionalization attempts have been examined by treating with Brønsted acids, Lewis acids, electrophiles, nucleophiles, 1,3-dipolar reagents and reagents containing multiple bonds able to be inserted. Various related complexes have been obtained under these conditions, in which one of the azide insertion compounds reductively eliminates to give an allylic functionalization product stoichiometrically. 3.1 reacts with various primary alcohols to give the decarbonylation dihydride complex To MRh(H) 2CO (4.1). 4.1 shows catalytic reactivity for primary alcohol decarbonylation under a photolytic condition. Meanwhile, 2.2 has been found to be more reactive than 4.1 for catalytic alcohol decarbonylation under the same condition. Various complexes and primary alcohols have been investigated as well. The proposed mechanism is based on the stochiometric reactions of the possible metal and organic intermediates. Primary amines, hypothesized to undergo a similar reaction pathway, have been verified to give dehydrogenative coupling product, imines. In the end, the well-developed neutral tridentate Tpm coordinates to the rhodium bis(ethylene) dimer in the presence of TlPF 6 to give the cationic complex, [TpmRh(C 2H 4) 2][PF 6] (5.1). 5.1 serves as the first example of explicit determination of the solid state hapticity, evidenced by X-ray structure, among all the cationic Tpm RM(C 2H 4) 2 + (Tpm R = Tpm, Tpm*, M = Rh, Ir) derivatives. The substitution chemistry of this compound has been studied by treating with soft and hard donors. The trimethylphosphine-sbustituted complex activates molecular hydrogen to give the dihydride compound.« less

Scrubbing masks magmatic degassing during repose at Cascade-Range and Aleutian-Arc volcanoes

USGS Publications Warehouse

Symonds, Robert B.; Janik, C.J.; Evans, William C.; Ritchie, B.E.; Counce, Dale; Poreda, R.J.; Iven, Mark

2003-01-01

Between 1992 and 1998, we sampled gas discharges from ≤173°C fumaroles and springs at 12 quiescent but potentially restless volcanoes in the Cascade Range and Aleutian Arc (CRAA) including Mount Shasta, Mount Hood, Mount St. Helens, Mount Rainier, Mount Baker, Augustine Volcano, Mount Griggs, Trident, Mount Mageik, Aniakchak Crater, Akutan, and Makushin. For each site, we collected and analyzed samples to characterize the chemical (H2O, CO2, H2S, N2, CH4, H2, HCl, HF, NH3, Ar, O2, He) and isotopic (δ13C of CO2, 3He/4He, 40Ar/36Ar, δ34S, δ13C of CH4, δ15N, and δD and δ18O of water) compositions of the gas discharges, and to create baseline data for comparison during future unrest. The chemical and isotopic data show that these gases contain a magmatic component that is heavily modified from scrubbing by deep hydrothermal (150° - 350°C) water (primary scrubbing) and shallow meteoric water (secondary scrubbing). The impact of scrubbing is most pronounced in gas discharges from bubbling springs; gases from boiling-point fumaroles and superheated vents show progressively less impact from scrubbing. The most effective strategies for detecting gas precursors to future CRAA eruptions are to measure periodically the emission rates of CO2 and SO2, which have low and high respective solubilities in water, and to monitor continuously CO2 concentrations in soils around volcanic vents. Timely resampling of fumaroles can augment the geochemical surveillance program by watching for chemical changes associated with drying of fumarolic pathways (all CRAA sites), increases in gas geothermometry temperatures (Mount Mageik, Trident, Mount Baker, Mount Shasta), changes in δ13C of CO2 affiliated with magma movement (all CRAA site), and increases in 3He/4He coupled with intrusion of new magma (Mount Rainier, Augustine Volcano, Makushin, Mount Shasta). Repose magmatic degassing may discharge substantial amounts of S and Cl into the edifices of Mount Baker and several other CRAA volcanoes that is trapped by primary and secondary scrubbing. The consequent acidic fluids produce ongoing alteration in the 0.2- to 3-km-deep hydrothermal systems and in fields of boiling-point fumaroles near the surface. Such alteration may influence edifice stability and contribute to the formation of more-hazardous cohesive debris flows. In particular, we recommend further investigation of the volume, extent, and hazards of hydrothermal alteration at Mount Baker. Other potential hazards associated with the CRAA volcano hydrothermal systems include hydrothermal eruptions and, for deeper systems intruded by magma, deep-seated edifice collapse.

Synthesis, photophysical properties and structures of organotin-Schiff bases utilizing aromatic amino acid from the chiral pool and evaluation of the biological perspective of a triphenyltin compound.

PubMed

Basu Baul, Tushar S; Kehie, Pelesakuo; Duthie, Andrew; Guchhait, Nikhil; Raviprakash, Nune; Mokhamatam, Raveendra B; Manna, Sunil K; Armata, Nerina; Scopelliti, Michelangelo; Wang, Ruimin; Englert, Ulli

2017-03-01

Five new organotin(IV) complexes of compositions [Me 2 SnL 1 ] (1), [Me 2 SnL 2 ] n (2), [Me 2 SnL 3 ] (3), [Ph 3 SnL 1 H] n (4) and [Ph 3 SnL 3 H] (5) (where L 1 =(2S)-2-((E)-((Z)-4-hydroxypent-3-en-2-ylidene)amino)-3-(1H-indol-3-yl)propanoate, L 2 =(2S)-(E)-2-((2-hydroxybenzylidene)amino)-3-(1H-indol-3-yl)propanoate and L 3 =(2S)-(E)-2-((1-(2-hydroxyphenyl)ethylidene)amino)-3-(1H-indol-3-yl)propanoate were synthesized and spectroscopically characterized. The crystal structures of 1-4 were determined. For the dimethyltin derivative 2, a polymeric chain structure was observed as a result of a long Sn∙∙∙O contact involving the exocyclic carbonyl oxygen-atom from the tridentate ligand of a neighboring Sn-complex unit. The tin atom in this complex has a distorted octahedral coordination geometry, in which the long Sn-O bond is almost trans to the tridentate ligand nitrogen-atom. In contrast, the dimethyltin(IV) complexes 1 and 3 displayed discrete monomeric structures where the tin atom has distorted trigonal-bipyramidal geometry with the two coordinating L oxygen atoms defining the axial positions. On the other hand, 4 is a chain polymer in the solid state. The ligand-bridged Sn atoms adopt a trans-Ph 3 SnO 2 trigonal-bipyramidal configuration with equatorial phenyl groups. A carboxylato oxygen atom from one and the hydroxyl oxygen of the successive ligand in the chain occupy the axial positions. The solution structures were predicted by the use of 119 Sn NMR chemical shifts. The photophysical properties of the complexes were investigated in the solid and in solution. The triphenyltin(IV) compound 4 was tested in detail ex vivo against A375 (human melanoma) cell line, exhibiting an IC 50 value of 261nM to induce cell death as assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay without significant alteration of cytolysis as determined by lactate dehydrogenase (LDH) assay. Compound 4-mediated potent cell death was also determined by Live and Dead assay and caspase-mediated cleavage of poly-ADP ribose polymerase (PARP). Potent cell death activity was not observed in primary cells, like blood-derived peripheral mononuclear cells (PBMC). Compound 4 inhibited the diphenyl hexatriene (DPH) binding to cells and decreased the micro viscosity in a dose-dependent manner. Additionally, the ability of 4 and cyclodextrin (CD) to interact was determined by molecular modelling. Copyright © 2016 Elsevier Inc. All rights reserved.

Imaging shallow magma chambers at Alaskan volcanoes with ambient seismic noise

NASA Astrophysics Data System (ADS)

Haney, M. M.; Prejean, S. G.

2009-05-01

Ambient noise tomography/inversion (ANT) is an emerging technique in seismology with the ability to provide 3D images of subsurface volcanic structure using relatively sparse seismic networks. The method relies on the principle that the cross-correlation of noise recordings at two different seismic stations reproduces an experiment in which one of the stations acts as an active source. Ambient seismic noise in the frequency band from 0.1 to 1 Hz is mostly composed of fundamental mode surface waves, of both Love and Rayleigh type. As a result, noise cross-correlations are sensitive to shear-wave structure and complement compressional-wave images computed from phase arrivals of local earthquakes. At Okmok volcano in the Aleutian islands, a 3D image constructed from 40 days of noise recordings in 2005 on a 12 station network clearly shows two low velocity zones (LVZs) centered about the 10-km-wide caldera: a shallow zone in the upper 1-2 km and a deeper zone between 4-4.5 km. The shallow LVZ is interpreted to be weak, poorly-consolidated material within the caldera; the deeper LVZ is indicative of the shallow magma chamber at Okmok. That the chamber is imaged as an LVZ in 2005 points to it remaining in a molten state throughout the time period between the 1997 and 2008 eruptions. The existence of a shallow chamber at Okmok is consistent with independent studies based on GPS, InSAR, and petrologic data. A 3D image has also been determined for the Katmai group of volcanoes along the Alaska peninsula from 60 days of continuous recordings in 2005 and 2006. An LVZ at Katmai Pass, previously known from local earthquake tomography (LET), is evident in the 3D shear-wave velocity model at depths down to 2 km BSL. That the LVZ exists in compressional-wave velocity models suggests it is a shallow magma storage area for Trident volcano. In contrast, low shear-wave velocity under Martin volcano is likely fluid-related, given the lack of low compressional-wave velocities in images derived from LET. Interestingly, a deep (> 5 km), subtle LVZ imaged between Trident and Mount Katmai may represent remnants of the magmatic conduit system from the cataclysmic 1912 eruption of Novarupta. A deployment of 11 temporary broadband seismometers are currently in place around Katmai Pass and should provide more constraints on the structure of the deep LVZ. The availability of many three-component seismometers within the Katmai permanent/temporary network makes it possible to additionally invert Love waves and the ratio of the horizontal-to-vertical motion of Rayleigh waves, the HV ratio, to further delineate volcanic structure from the ambient seismic field.

Effective concentration as a tool for quantitatively addressing preorganization in multicomponent assemblies: application to the selective complexation of lanthanide cations.

PubMed

Canard, Gabriel; Koeller, Sylvain; Bernardinelli, Gérald; Piguet, Claude

2008-01-23

The beneficial entropic effect, which may be expected from the connection of three tridentate binding units to a strain-free covalent tripod for complexing nine-coordinate cations (Mz+ = Ca2+, La3+, Eu3+, Lu3+), is quantitatively analyzed by using a simple thermodynamic additive model. The switch from pure intermolecular binding processes, characterizing the formation of the triple-helical complexes [M(L2)3]z+, to a combination of inter- and intramolecular complexation events in [M(L8)]z+ shows that the ideal structural fit observed in [M(L8)]z+ indeed masks large energetic constraints. This limitation is evidenced by the faint effective concentrations, ceff, which control the intramolecular ring-closing reactions operating in [M(L8)]z+. This predominence of the thermodynamic approach over the usual structural analysis agrees with the hierarchical relationships linking energetics and structures. Its simple estimation by using a single microscopic parameter, ceff, opens novel perspectives for the molecular tuning of specific receptors for the recognition of large cations, a crucial point for the programming of heterometallic f-f complexes under thermodynamic control.

Composition, Characterization and Antibacterial activity of Mn(II), Co(II),Ni(II), Cu(II) Zn(II) and Cd(II) mixed ligand complexes Schiff base derived from Trimethoprim with 8-Hydroxy quinoline

NASA Astrophysics Data System (ADS)

Numan, Ahmed T.; Atiyah, Eman M.; Al-Shemary, Rehab K.; Ulrazzaq, Sahira S. Abd

2018-05-01

New Schiff base ligand 2-((4-amino-5-(3, 4, 5-trimethoxybenzyl) pyrimidin-2-ylimino) (phenyl)methyl)benzoic acid] = [HL] was synthesized using microwave irradiation trimethoprim and 2-benzoyl benzoic acid. Mixed ligand complexes of Mn((II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) are reacted in ethanol with Schiff base ligand [HL] and 8-hydroxyquinoline [HQ] then reacted with metal salts in ethanol as a solvent in (1:1:1) ratio. The ligand [HL] is characterized by FTIR, UV-Vis, melting point, elemental microanalysis (C.H.N), 1H-NMR, 13C-NMR, and mass spectra. The mixed ligand complexes are characterized by infrared spectra, electronic spectra, (C.H.N), melting point, atomic absorption, molar conductance and magnetic moment measurements. These measurements indicate that the ligand [HL] coordinates with metal (II) ion in a tridentate manner through the oxygen and nitrogen atoms of the ligand, octahedral structures are suggested for these complexes. Antibacterial activity of the ligands [HL], [HQ] and their complexes are studied against (gram positive) and (gram negative) bacteria.

Can thermal instabilities drive galactic precipitation and explain observed circumgalactic structure?

NASA Astrophysics Data System (ADS)

Silvia, Devin

2015-10-01

Understanding the complex nature of the circumgalactic medium (CGM) has been a target of numerous research efforts, both observationally and theoretically. While significant progress has been made in probing the structure and thermodynamic state of the CGM through the detection of metal line absorption systems using the Hubble Space Telescope (HST), a complete picture of the physical mechanisms that produce the observed properties does not yet exist. Recent theoretical work has suggested that a delicate balance between radiative cooling and thermal feedback detemines whether or not the CGM is capable of sustaining a stable, multiphase medium that would allow cool clouds to precipitate out of the galactic halo. This new theoretical framework may provide the explanation for many observational results. In this project, we will detemine whether or not this elegant and simple precipitation model can be supported by physics-rich numerical simulations of isolated galaxies. We will use our simulations to gain a deeper understanding of the precipitation model and explore the ionization and temperature stucture of the CGM. Our analysis will include the comparison of realistic synthetic spectra to those produced by HST, using the newly-developed Trident software package.

Potential Mechanism of Action of 3'-Demethoxy-6-O-demethyl-isoguaiacin on Methicillin Resistant Staphylococcus aureus.

PubMed

Favela-Hernández, Juan Manuel J; Clemente-Soto, Aldo F; Balderas-Rentería, Isaías; Garza-González, Elvira; Camacho-Corona, María del Rayo

2015-07-08

Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3'-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from Larrea tridentate, showed the best activity towards methicillin-resistant S. aureus. Thus, the aim of this study was to determine the potential molecular mechanism of the antibacterial activity of 3'-demethoxy-6-O-demethylisoguaiacin against methicillin-resistant S. aureus using microarray technology. Results of microarray genome expression were validated by real-time polymerase chain reaction (RT-PCR). The genetic profile expression results showed that lignan 3'-demethoxy-6-O-demethylisoguaiacin had activity on cell membrane affecting proteins of the ATP-binding cassette (ABC) transport system causing bacteria death. This molecular mechanism is not present in any antibacterial commercial drug and could be a new target for the development of novel antibacterial agents.

Potential mechanism of action of 3'-demethoxy-6-O-demethyl-isoguaiacin on methicillin resistant Staphylococcus aureus.

PubMed

Favela-Hernández, Juan Manuel J; Clemente-Soto, Aldo F; Balderas-Rentería, Isaías; Garza-González, Elvira; Camacho-Corona, María Del Rayo

2015-07-08

Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3'-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from Larrea tridentate, showed the best activity towards methicillin-resistant S. aureus. Thus, the aim of this study was to determine the potential molecular mechanism of the antibacterial activity of 3'-demethoxy-6-O-demethylisoguaiacin against methicillin-resistant S. aureus using microarray technology. Results of microarray genome expression were validated by real-time polymerase chain reaction (RT-PCR). The genetic profile expression results showed that lignan 3'-demethoxy-6-O-demethylisoguaiacin had activity on cell membrane affecting proteins of the ATP-binding cassette (ABC) transport system causing bacteria death. This molecular mechanism is not present in any antibacterial commercial drug and could be a new target for the development of novel antibacterial agents.

Pyrrolo-dC Metal-Mediated Base Pairs in the Reverse Watson-Crick Double Helix: Enhanced Stability of Parallel DNA and Impact of 6-Pyridinyl Residues on Fluorescence and Silver-Ion Binding.

PubMed

Yang, Haozhe; Mei, Hui; Seela, Frank

2015-07-06

Reverse Watson-Crick DNA with parallel-strand orientation (ps DNA) has been constructed. Pyrrolo-dC (PyrdC) nucleosides with phenyl and pyridinyl residues linked to the 6 position of the pyrrolo[2,3-d]pyrimidine base have been incorporated in 12- and 25-mer oligonucleotide duplexes and utilized as silver-ion binding sites. Thermal-stability studies on the parallel DNA strands demonstrated extremely strong silver-ion binding and strongly enhanced duplex stability. Stoichiometric UV and fluorescence titration experiments verified that a single (2py) PyrdC-(2py) PyrdC pair captures two silver ions in ps DNA. A structure for the PyrdC silver-ion base pair that aligns 7-deazapurine bases head-to-tail instead of head-to-head, as suggested for canonical DNA, is proposed. The silver DNA double helix represents the first example of a ps DNA structure built up of bidentate and tridentate reverse Watson-Crick base pairs stabilized by a dinuclear silver-mediated PyrdC pair. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectral, biological screening of metal chelates of chalcone based Schiff bases of N-(3-aminopropyl) imidazole.

PubMed

Kalanithi, M; Rajarajan, M; Tharmaraj, P; Sheela, C D

2012-02-15

Tridentate chelate complexes of Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized from the chalcone based ligands 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-(phenylallyl)]phenol(HL(1)), 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-p-tolylallyl]phenol(HL(2)), 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-4-nitrophenylallyl]phenol(HL(3)). Microanalytical data, UV-vis spectrophotometric method, magnetic susceptibility measurements, IR, 1H NMR, Mass, and EPR techniques were used to characterize the structure of chelates. The electronic absorption spectra and magnetic susceptibility measurements suggest a distorted square planar geometry for the copper(II) ion. The other metal complexes show distorted tetrahedral geometry. The coordination of the ligands with metal(II) ions was further confirmed by solution fluorescence spectrum. The antimicrobial activity of the ligands and metal(II) complexes against the species Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albigans and Aspergillus niger has been carried out and compared. The electrochemical behavior of copper(II) complex is studied by cyclic voltammetry. Copyright © 2011 Elsevier B.V. All rights reserved.

Deferasirox pharmacokinetic evaluation in β-thalassaemia paediatric patients.

PubMed

Allegra, Sarah; Cusato, Jessica; De Francia, Silvia; Pirro, Elisa; Massano, Davide; Piga, Antonio; D'Avolio, Antonio

2017-05-01

Iron chelation in the transfusion-dependent anaemias management is essential to prevent end-organ damage and to improve survival. Deferasirox is a once-daily orally active tridentate selective iron chelator which pharmacokinetic disposition could influence treatment efficacy and toxicity. Therapeutic drug monitoring is an important tool for optimizing drug utilization and doses. A fully validated chromatographic method was used to quantify deferasirox concentration in plasma collected from paediatric patients with β-thalassaemia. Samples obtained after 5 days of washout or in naïve patients before and after 2, 4, 6 and 24 h drug administration were evaluated. Associations between variables were tested using the Pearson test. Twenty paediatric patients were enrolled; they were mainly men (13.65%), with median age of 6.35 years and body mass index of 15.45 kg/m 2 . Concerning pharmacokinetic parameters, a higher interindividual variability was shown. A positive, but not significant, correlation (r = 0.363; P = 0.115) was found between deferasirox area under the concentration curve over 24 h (AUC) and drug dose. Monitoring plasma deferasirox concentrations appears beneficial for guiding appropriate patient treatment, enhancing effectiveness and minimizing toxicity. © 2016 Royal Pharmaceutical Society.

How Native and Alien Metal Cations Bind ATP: Implications for Lithium as a Therapeutic Agent

NASA Astrophysics Data System (ADS)

Dudev, Todor; Grauffel, Cédric; Lim, Carmay

2017-02-01

Adenosine triphosphate (ATP), the major energy currency of the cell, exists in solution mostly as ATP-Mg. Recent experiments suggest that Mg2+ interacts with the highly charged ATP triphosphate group and Li+ can co-bind with the native Mg2+ to form ATP-Mg-Li and modulate the neuronal purine receptor response. However, it is unclear how the negatively charged ATP triphosphate group binds Mg2+ and Li+ (i.e. which phosphate group(s) bind Mg2+/Li+) and how the ATP solution conformation depends on the type of metal cation and the metal-binding mode. Here, we reveal the preferred ATP-binding mode of Mg2+/Li+ alone and combined: Mg2+ prefers to bind ATP tridentately to each of the three phosphate groups, but Li+ prefers to bind bidentately to the terminal two phosphates. We show that the solution ATP conformation depends on the cation and its binding site/mode, but it does not change significantly when Li+ binds to Mg2+-loaded ATP. Hence, ATP-Mg-Li, like Mg2+-ATP, can fit in the ATP-binding site of the host enzyme/receptor, activating specific signaling pathways.

Synthesis, spectral characterization, molecular modeling, biological activity and potentiometric studies of 4-amino-5-mercapto-3-methyl-S-triazole Schiff's base complexes

NASA Astrophysics Data System (ADS)

Alaghaz, Abdel-Nasser M. A.; Zayed, Mohamed E.; Alharbi, Suliman A.

2015-03-01

The Schiff's base derived from condensation of s-triazole (4-amino-5-mercapto-3-methyl-S-triazole) with pyridine-2-aldehyde and their corresponding Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. The isolated solid complexes were characterized by elemental analyses, molar conductance, spectral (IR, UV-Vis, 1H NMR, mass), magnetic moment and thermal measurements. The IR spectral data suggest that the ligand coordinate in a tridentate manner (SNN) via the one thiol (SH), one pyridine ring and the azomethine (Cdbnd N) groups. The data show that the complexes have composition of ML2 type. The activation of thermodynamic parameters are calculated using Coats-Redfern, Horowitz-Metzger (HM), and Piloyan-Novikova (PN). The octahedral geometry of the complexes is confirmed using DFT method from DMOL3 calculations and ligand field parameters. Protonation constants of Schiff base and stability constants of their binary metal complexes have been determined potentiometrically in 50% DMSO-water media at 25 °C and ionic strength 0.10 M potassium nitrate. The biological activity of these compounds against various fungi has been investigated.

Cytotoxicity of Cyclometalated Platinum Complexes Based on Tridentate NCN and CNN-coordinating ligands: Remarkable Coordination Dependence

PubMed Central

Vezzu, Dileep A. k.; Lu, Qun; Chen, Yan-Hua; Huo, Shouquan

2014-01-01

A series of cyclometalated platinum complexes with diverse coordination patterns and geometries were screened for their anticancer activity. It was discovered that the NʌCʌN-coordinated platinum complex based on 1,3-di(pyridyl)benzene displayed much higher cytotoxicity against human lung cancer cells NCI-H522, HCC827, and NCI-H1299, and human prostate cancer cell RV1 than cisplatin. In a sharp contrast, the CʌNʌN-coordinated platinum complex based on 6-phenyl-2,2′-bipyridine was ineffective on these cancer cells. This remarkable difference in cytotoxicity displayed by NʌCʌN- and CʌNʌN-coordinated platinum complexes was related to the trans effect of the carbon donor in the cyclometalated platinum complexes, which played a crucial role in facilitating the dissociation of the chloride ligand to create an active binding site. The DNA binding was studied for the NʌCʌN-coordinated platinum complex using electrophoresis and emission titration. The cellular uptake observed by fluorescent microscope showed the complex is largely concentrated in the cytoplasm. The possible pathways for the cell apoptosis was studied by western blot analysis and the activation of PARP via caspase 7 was observed. PMID:24531534

Design of a Photoredox Catalyst that Enables the Direct Synthesis of Carbamate-Protected Primary Amines via Photoinduced, Copper-Catalyzed N-Alkylation Reactions of Unactivated Secondary Halides.

PubMed

Ahn, Jun Myun; Peters, Jonas C; Fu, Gregory C

2017-12-13

Despite the long history of S N 2 reactions between nitrogen nucleophiles and alkyl electrophiles, many such substitution reactions remain out of reach. In recent years, efforts to develop transition-metal catalysts to address this deficiency have begun to emerge. In this report, we address the challenge of coupling a carbamate nucleophile with an unactivated secondary alkyl electrophile to generate a substituted carbamate, a process that has not been achieved effectively in the absence of a catalyst; the product carbamates can serve as useful intermediates in organic synthesis as well as bioactive compounds in their own right. Through the design and synthesis of a new copper-based photoredox catalyst, bearing a tridentate carbazolide/bisphosphine ligand, that can be activated upon irradiation by blue-LED lamps, we can achieve the coupling of a range of primary carbamates with unactivated secondary alkyl bromides at room temperature. Our mechanistic observations are consistent with the new copper complex serving its intended role as a photoredox catalyst, working in conjunction with a second copper complex that mediates C-N bond formation in an out-of-cage process.

Bis[1-meth­oxy-2,2,2-tris­(pyrazol-1-yl-κN 2)ethane]­nickel(II) bis­(tri­fluoro­methane­sulfonate) dihydrate

PubMed Central

Lyubartseva, Ganna; Parkin, Sean; Mallik, Uma Prasad

2013-01-01

In the title salt, [Ni(C12H14N6O)2](CF3SO3)2·2H2O, the NiII cation is located on an inversion centre and is coordinated by six N atoms from two tridentate 1-meth­oxy-2,2,2-tris­(pyrazol-1-yl)ethane ligands in a distorted octa­hedral geometry. The Ni—N distances range from 2.0594 (12) to 2.0664 (12) Å, intra-ligand N—Ni—N angles range from 84.59 (5) to 86.06 (5)°, and adjacent inter-ligand N—Ni—N angles range between 93.94 (5) and 95.41 (5)°. In the crystal, inversion-related pyrazole rings are π–π stacked, with an inter­planar spacing of 3.4494 (18) Å, forming chains that propagate parallel to the a-axis direction. Inter­molecular O—H⋯O hydrogen bonds are present between water mol­ecules and tri­fluoro­methane­sulfonate anions. PMID:24098167

Exploring the potential energy surface for the interaction of sterically hindered trichloro(diethylenetriamine)gold(III) complexes with water.

PubMed

Dos Santos, Hélio F; Paschoal, Diego; Burda, Jaroslav V

2012-11-15

The reactivity of gold(III) complexes is analyzed for a series of derivatives of 3-azapentane-1,5-diamine (dien) tridentate ligand that can contain some bulky substituents. Two distinct series of compounds are considered where the dien ligand is either deprotonated (R-dien-H) or protonated (R-dien) at the secondary amine where R = ethyl (Et) or methyl (Me). While the deprotonated species will occur in neutral and basic solutions, the protonated forms are likely to be present in acidic environment. Hydration reaction (water/Cl(-) ligand exchange) of 14 complexes is modeled with quantum chemical calculations. Our calculations predict that the reactivity decreases with the increase in the molecular volume of the substituted dien ligand, and the calculated rate constants are in satisfactory agreement with experimental results. In addition, quantitative structure/reactivity models are proposed where the angle between the entering and leaving groups in the transition state structure (the reactivity angle) is used as a molecular descriptor. These models explain the trend of the relative reactivity of these complexes and can be used to design new ligands for gold(III) complexes aiming to adjust the reactivity of the complex.

Synthesis, characterization, photoluminescence and cytotoxic properties of novel luminescent Eu(III)complexes based on chromone Schiff base

NASA Astrophysics Data System (ADS)

Saif, M.; El-Shafiy, Hoda F.; Mashaly, Mahmoud M.; Eid, Mohamed F.; Nabeel, A. I.; Fouad, R.

2018-06-01

Three novel Eu(III) phosphor complexes, [Eu(HL)(OH2)2(C2H5OH)](NO3)2 (1), [Eu(HL)(Bpy)(NO3)2(EtOH)] (2) and [Eu(HL)(Phen)(NO3)2(H2O)] (3) (HL = (11E)-2-hydroxy-N/-((4-oxo-4H-chromen-3-yl)methylene)benzohydrazide; Bpy = 2,2/-bibyridyl and Phen = 1,10-phenanthroline) were prepared. Elemental, thermal, FT-IR and XRD methods were used to characterize their structural configuration. The HL behaves as a monoanionic tridentate ligand. The XRD analysis shows that the ligand and its Eu3+complexes are in nano domain. From fluorescence spectroscopy, all the prepared complexes are highly luminescent, having an impressive visual emission under UV excitation. The H2L and its Eu3+nano-complexes (1-3) were tested for their in vitro cytotoxicity against Ehrlich Ascites Carcinoma cell line (EAC). The Eu(III) nano-complexes (1-3) effectively inhibited EAC growth with IC50 value of 25 μM. The high antitumor activity of the Eu(III) nano-complexes (1-3) were attributed to its chemical structure, and nano size properties.

Removal of heavy metals from aqueous waste streams using surface-modified nanosized TiO{sub 2} photocatalysts.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meshkov, N. K.

1998-08-27

Titanium dioxide (TiO{sub 2}) colloidal particles ({approximately}45{angstrom}) whose surfaces were modified with chelating agents for photocatalytic removal of heavy-metal ions and their subsequent reduction to metallic form were investigated. Experiments were performed on nanoparticle TiO{sub 2} colloids derivatized with bidentate and tridentate ligands (thiolactic acid [TLA], cysteine, and alanine [ALA]) in batch mode in a photoreactor with 254nm light. We used catalysts designed and synthesized for selective and efficient removal of Pb and Cu with and without added hole scavenger (methanol). Parallel experiments also have been carried out in the dark to study metal ion adsorption properties. Solutions have beenmore » filtered to remove TiO{sub 2}, and metal particulates. Both the native solution and the metal deposited on the nanocrystalline TiO{sub 2} particles were analyzed. Results demonstrate that for the case of lead, the most effective TiO{sub 2} surface modifier was TLA (>99% Pb(II) removed from solution). Experiments performed to study Cn removal using TiO{sub 2} colloids modified with alanine showed that copper ions were effectively removed and reduced to metallic form in the presence of methanol.« less

Synthesis, crystal structure, catecholase and phenoxazinone synthase activities of a mononuclear cobalt(III) complex containing in situ formed tridentate N-donor Schiff base

NASA Astrophysics Data System (ADS)

Maji, Ashis Kumar; Chatterjee, Arnab; Khan, Sumitava; Ghosh, Barindra Kumar; Ghosh, Rajarshi

2017-10-01

Synthesis and structural characterization of a mononuclear cobalt(III) Schiff base complex is reported. It crystallizes with monoclinic crystal system with P21/n space group with a = 9.9793(4) Å, b = 28.2907(12) Å and c = 13.1233(6) Å, and β = 97.532(3)°. The compound is active to catecholase and phenoxazinone synthase activities in MeOH, and MeOH and MeCN solvents, respectively at room temperature. Each of the reactions was found to be of first order with reaction rate 8.08 × 10-3 min-1 (MeOH) for the catecholase activity and 1.05 × 10-3 min-1 (MeOH) and 3.82 × 10-3 min-1 (MeCN) for the phenoxazinone synthase activity. The turn over numbers for the catecholase activity is 5.02 × 103 h-1 (MeOH) and for the phenoxazinone synthase activity is 4.59 × 103 h-1 (MeOH) and 5.12 × 103 h-1 (MeCN). Substrate-catalyst adduct was tried to be trapped in each case using mass spectrometry.

Synthesis, Photochemical, and Redox Properties of Gold(I) and Gold(III) Pincer Complexes Incorporating a 2,2′:6′,2″-Terpyridine Ligand Framework

PubMed Central

2015-01-01

Reaction of [Au(C6F5)(tht)] (tht = tetrahydrothiophene) with 2,2′:6′,2″-terpyridine (terpy) leads to complex [Au(C6F5)(η1-terpy)] (1). The chemical oxidation of complex (1) with 2 equiv of [N(C6H4Br-4)3](PF6) or using electrosynthetic techniques affords the Au(III) complex [Au(C6F5)(η3-terpy)](PF6)2 (2). The X-ray diffraction study of complex 2 reveals that the terpyridine acts as tridentate chelate ligand, which leads to a slightly distorted square-planar geometry. Complex 1 displays fluorescence in the solid state at 77 K due to a metal (gold) to ligand (terpy) charge transfer transition, whereas complex 2 displays fluorescence in acetonitrile due to excimer or exciplex formation. Time-dependent density functional theory calculations match the experimental absorption spectra of the synthesized complexes. In order to further probe the frontier orbitals of both complexes and study their redox behavior, each compound was separately characterized using cyclic voltammetry. The bulk electrolysis of a solution of complex 1 was analyzed by spectroscopic methods confirming the electrochemical synthesis of complex 2. PMID:26496068

Potentiometric and DFT studies of Cu(II) complexes with glycylglycine and methionine of interest for the brain chemistry

NASA Astrophysics Data System (ADS)

Vilhena, Felipe S.; Felcman, Judith; Szpoganicz, Bruno; Miranda, Fabio S.

2017-01-01

A large number of copper (II) complexes have been used as mimetic models for metalloproteins and metalloenzymes. Due to the lack of structural information about copper (II) complexes in aqueous solution, the coordination environment of this metal is not well established. In this work, pKa values of the complexes in the Cu:GlyGly, Cu:Met and Cu:GlyGly:Met systems were calculated by potentiometric titration at 25 °C and ionic strength of 0.1 mol L-1. The coordination modes of the ligands were explored for the main hydrolytic species throught RI-PBE/def2-SVP/COSMO level. In the Cu:GlyGly system, DFT results indicated that the NamineNpept coordination of dipeptide is 2.1 kcal mol-1 more stable than the tridentate NamineNpeptOcarboxy coordination moiety. The deprotonation of the peptide nitrogen is 13.7 kcal mol-1 more favorable than the hydrolysis of the water molecule coordinated to the metal. In the Cu:GlyGly:Met system, the sulfur atom does not belong to the copper (II) coordination sphere. Once the copper ion is incorporated into peptides, another ligand as methionine could bind to this system and carry an antioxidant site to different brain regions.

Vibrational investigation on the copper(II) binding mode of carcinine and its pH dependence

NASA Astrophysics Data System (ADS)

Torreggiani, Armida; Reggiani, Matteo; Manco, Immacolata; Tinti, Anna

2007-05-01

A comparative FT-Raman and FT-IR study of Carcinine (Carc), a natural imidazole dipeptide, and its complexes with Cu(II) ions was performed at different pH's. Both Raman and IR spectra present marker bands useful for the identification of the predominant complexes; in particular, Raman spectroscopy appears useful for identifying the metal-coordination site of the imidazole ring (N π or N τ atoms) of Carc. Free Carc shows a strong network of H-bonds and tautomer I (N τ-H) is the preferred form of the imidazolic ring (bands at 1578, 1292 and 988 cm -1). The presence of Cu(II) does not affect the tautomeric equilibrium at pH 7, whereas the deprotonation of both N-imidazolic nitrogens is strongly induced at higher pH. Under neutral and alkaline conditions the primary amino group takes part to the Cu(II) chelation, whereas all the peptidic moieties are involved in coordination only at pH 7. Thus, Carc acts as a tri-dentate ligand at neutral pH, mainly giving a monomeric complex, [CuLH -1], containing tautomer I, whereas an oligonuclear complex, probably [Cu 4L 4H -8], where metal-imidazolate ions connect different ligand molecules, predominates at alkaline pH.

MicroRNAs form triplexes with double stranded DNA at sequence-specific binding sites; a eukaryotic mechanism via which microRNAs could directly alter gene expression

DOE PAGES

Paugh, Steven W.; Coss, David R.; Bao, Ju; ...

2016-02-04

MicroRNAs are important regulators of gene expression, acting primarily by binding to sequence-specific locations on already transcribed messenger RNAs (mRNA). Recent studies indicate that microRNAs may also play a role in up-regulating mRNA transcription levels, although a definitive mechanism has not been established. Double-helical DNA is capable of forming triple-helical structures through Hoogsteen and reverse Hoogsteen interactions in the major groove of the duplex, and we show physical evidence that microRNAs form triple-helical structures with duplex DNA, and identify microRNA sequences that favor triplex formation. We developed an algorithm (Trident) to search genome-wide for potential triplex-forming sites and show thatmore » several mammalian and non-mammalian genomes are enriched for strong microRNA triplex binding sites. We show that those genes containing sequences favoring microRNA triplex formation are markedly enriched (3.3 fold, p<2.2 x 10 -16) for genes whose expression is positively correlated with expression of microRNAs targeting triplex binding sequences. As a result, this work has thus revealed a new mechanism by which microRNAs can interact with gene promoter regions to modify gene transcription.« less

Investigation of electronic structure of tri- and tetranuclear molybdenum clusters by X-ray photoelectron and emission spectroscopies and quantum chemical methods

NASA Astrophysics Data System (ADS)

Kryuchkova, Natalya A.; Syrokvashin, Mikhail M.; Gushchin, Artem L.; Korotaev, Evgeniy V.; Kalinkin, Alexander V.; Laricheva, Yuliya A.; Sokolov, Maxim N.

2018-02-01

Charge state studies of compounds [Mo3S4(tu)8(H2O)]Cl4·4H2O (1), [Mo3S4Cl3(dbbpy)3]Cl·5H2O (2), [Mo3S4(CuCl)Cl3(dbbpy)3][CuCl2] (3), containing {Mo3S4}4+ and {Mo3CuS4}5+ cluster cores bearing terminal thiourea (tu) or 4,4‧-di-tert-butyl-2,2‧-bipyridine (dbbpy) ligands, have been performed by X-ray photoelectron and X-ray emission spectroscopies combined with quantum chemical calculations. The best agreement between theory and experiments has been obtained using the B3LYP method. According to the experimental and calculated data, the Mo atoms are in the oxidation state 4+ for all compounds. The energies and shapes of the Cu2p lines indicate formal oxidation states of Cu as 1+. The coordination of Cu(I) to the cluster {Mo3S4} in 3 does not lead to significant changes in the charge state of the molybdenum atoms and the {Mo3S4} unit can be considered as a tridentate metallothia crown ether.

Cytotoxicity of cyclometalated platinum complexes based on tridentate NCN and CNN-coordinating ligands: remarkable coordination dependence.

PubMed

Vezzu, Dileep A K; Lu, Qun; Chen, Yan-Hua; Huo, Shouquan

2014-05-01

A series of cyclometalated platinum complexes with diverse coordination patterns and geometries were screened for their anticancer activity. It was discovered that the N^C^N-coordinated platinum complex based on 1,3-di(pyridyl)benzene displayed much higher cytotoxicity against human lung cancer cells NCI-H522, HCC827, and NCI-H1299, and human prostate cancer cell RV1 than cisplatin. In a sharp contrast, the C^N^N-coordinated platinum complex based on 6-phenyl-2,2'-bipyridine was ineffective on these cancer cells. This remarkable difference in cytotoxicity displayed by N^C^N- and C^N^N-coordinated platinum complexes was related to the trans effect of the carbon donor in the cyclometalated platinum complexes, which played a crucial role in facilitating the dissociation of the chloride ligand to create an active binding site. The DNA binding was studied for the N^C^N-coordinated platinum complex using electrophoresis and emission titration. The cellular uptake observed by fluorescent microscope showed that the complex is largely concentrated in the cytoplasm. The possible pathways for the cell apoptosis were studied by western blot analysis and the activation of PARP via caspase 7 was observed. Copyright © 2014 Elsevier Inc. All rights reserved.

Biomechanical modeling of acetabular component polyethylene stresses, fracture risk, and wear rate following press-fit implantation.

PubMed

Ong, Kevin L; Rundell, Steve; Liepins, Imants; Laurent, Ryan; Markel, David; Kurtz, Steven M

2009-11-01

Press-fit implantation may result in acetabular component deformation between the ischial-ilial columns ("pinching"). The biomechanical and clinical consequences of liner pinching due to press-fit implantation have not been well studied. We compared the effects of pinching on the polyethylene fracture risk, potential wear rate, and stresses for two different thickness liners using computational methods. Line-to-line ("no pinch") reaming and 2 mm underreaming press fit ("pinch") conditions were examined for Trident cups with X3 polyethylene liner wall thicknesses of 5.9 mm (36E) and 3.8 mm (40E). Press-fit cup deformations were measured from a foam block configuration. A hybrid material model, calibrated to experimentally determined stress-strain behavior of sequentially annealed polyethylene, was applied to the computational model. Molecular chain stretch did not exceed the fracture threshold in any cases. Nominal shell pinch of 0.28 mm was estimated to increase the volumetric wear rate by 70% for both cups and peak contact stresses by 140 and 170% for the 5.9 and 3.8 mm-thick liners, respectively. Although pinching increases liner stresses, polyethylene fracture is highly unlikely, and the volumetric wear rates are likely to be low compared to conventional polyethylene. (c) 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Effects of ancillary ligands on selectivity of protein labeling with platinum(II) chloro complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Xia-Ying.

1990-02-01

Potassium (2,6-pyridinedicarboxylato)chloroplatinate(II) was synthesized. The molecular structure of the complex in (n-Bu){sub 4}N(Pt(dipic)Cl){center dot}0.5H{sub 2}O was determined by x-ray crystallography. The (Pt(dipic)Cl){sup {minus}} is essentially planar and contains a Pt(II) atom, a tridentate dipicolinate dianion ligand, and a unidentate Cl{sup {minus}} ligand. The bis(bidentate) complex trans-(Pt(dipic){sub 2}){sup 2{minus}} was also observed by {sup 1}H NMR. A red gel-like substance was observed when the yellow aqueous solution of K(Pt(dipic)Cl) was cooled or concentrated. The K(Pt(dipic)Cl) molecules form stacks in the solid state and gel-like substance but remain monomeric over a wide range of concentrations and temperatures. The reactivity and selectivity of(Pt(dipic)Cl){supmore » {minus}} toward cytochromes c from horse and tuna were studied. The new transition-metal reagent is specific for methionine residues. Di(2-pyridyl-{beta}-ethyl)sulfidochloroplatinum(II) chloride dihydrate was also synthesized. This complex labels histidine and methionine residues in cytochrome c. The ancillary ligands in these platinum(II) complexes clearly determine the selectivity of protein labeling. 106 refs., 10 figs., 11 tabs.« less

An unusual mode of failure of a tripolar constrained acetabular liner: a case report.

PubMed

Banks, Louisa N; McElwain, John P

2010-04-01

Dislocation after primary total hip arthroplasty (THA) is the most commonly encountered complication and is unpleasant for both the patient and the surgeon. Constrained acetabular components can be used to treat or prevent instability after primary total hip arthroplasty. We present the case of a 42-year-old female with a BMI of 41. At 18 months post-primary THA the patient underwent further revision hip surgery after numerous (more than 20) dislocations. She had a tripolar Trident acetabular cup (Stryker-Howmedica-Osteonics, Rutherford, New Jersey) inserted. Shortly afterwards the unusual mode of failure of the constrained acetabular liner was noted from radiographs in that the inner liner had dissociated from the outer. The reinforcing ring remained intact and in place. We believe that the patient's weight, combined with poor abductor musculature caused excessive demand on the device leading to failure at this interface when the patient flexed forward. Constrained acetabular components are useful implants to treat instability but have been shown to have up to 42% long-term failure rates with problems such as dissociated inserts, dissociated constraining rings and dissociated femoral rings being sited. Sometimes they may be the only option left in difficult cases such as illustrated here, but still unfortunately have the capacity to fail in unusual ways.

Surface temperature measurements of a levitated water drop during laser irradiation

NASA Astrophysics Data System (ADS)

Brownell, Cody; Tracey, Timothy

2016-11-01

Simulation of high energy laser propagation and scattering in the maritime environment is problematic, due to the high liklihood of turbulence, fog, and rain or sea spray within the beam path. Laser interactions with large water drops (diameters of approximately 1-mm), such as those found in a light rain, have received relatively less attention. In this regime a high energy laser will rapidly heat and vaporize a water drop as it traverses the beam path, but the exact heating / vaporization rate, its dependence on impurities, and ancillary effects on the drop or surroundings are unclear. In this work we present surface temperature measurements of a water drop obtained using a FLIR IR camera. The drop is acoustically levitated, and subject to a continuous wave laser with a wavelength of 1070-nm and a mean irradiance of approximately 500 W/cm2. These measurements show that the steady-state surface temperature of the drop is well below the saturation temperature, yet based on the time history of the drop volume vaporization begins almost immediately upon laser strike. Inferences on the turbulence characteristics within the drop are also made from measurements of the fluctuations in the surface temperature. Supported by ONR, HEL-JTO, and USNA Trident Scholar Program.

Reclamation with Recovery of Radionuclides and Toxic Metals from Contaminated Materials, Soils, and Wastes

NASA Technical Reports Server (NTRS)

Francis, A. J.; Dodge, C. J.

1993-01-01

A process has been developed at Brookhaven National Laboratory (BNL) for the removal of metals and radionuclides from contaminated materials, soils, and waste sites. In this process, citric acid, a naturally occurring organic complexing agent, is used to extract metals such as Ba, Cd, Cr, Ni, Zn, and radionuclides Co, Sr, Th, and U from solid wastes by formation of water soluble, metal-citrate complexes. Citric acid forms different types of complexes with the transition metals and actinides, and may involve formation of a bidentate, tridentate, binuclear, or polynuclear complex species. The extract containing radionuclide/metal complex is then subjected to microbiological degradation followed by photochemical degradation under aerobic conditions. Several metal citrate complexes are biodegraded, and the metals are recovered in a concentrated form with the bacterial biomass. Uranium forms binuclear complex with citric acid and is not biodegraded. The supernatant containing uranium citrate complex is separated and upon exposure to light, undergoes rapid degradation resulting in the formation of an insoluble, stable polymeric form of uranium. Uranium is recovered as a precipitate (polyuranate) in a concentrated form for recycling or for appropriate disposal. This treatment process, unlike others which use caustic reagents, does not create additional hazardous wastes for disposal and causes little damage to soil which can then be returned to normal use.

Resonance Search for a Heavy Photon in the 2015 Engineering Run Data of the Heavy Photon Search Experiment

NASA Astrophysics Data System (ADS)

Moreno, Omar; Heavy Photon Search Collaboration

2017-01-01

The Heavy Photon Search (HPS) experiment at Jefferson Lab is searching for a new U(1) vector boson (``heavy photon'',``dark photon'' or A') in the mass range of 20-500 MeV/c2. An A' in this mass range is theoretically favorable and may also mediate dark matter interactions. The A' couples to the ordinary photon through kinetic mixing, which induces their coupling to electric charge. Since heavy photons couple to electrons, they can be produced through a process analogous to bremsstrahlung, subsequently decaying to an e+e- , which can be observed as a narrow resonance above the dominant QED trident background. For suitably small couplings, heavy photons travel detectable distances before decaying, providing a second signature. Using the CEBAF electron beam at Jefferson Lab incident on a thin tungsten target, along with a compact, large acceptance forward spectrometer consisting of a silicon vertex tracker and lead tungstate electromagnetic calorimeter, HPS is accessing unexplored regions in the mass-coupling phase space. The HPS engineering run took place in spring of 2015 using a 1.056 GeV, 50 nA beam and collected 1165 nb-1 (7.29 mC) of data. This talk will present the results of a resonance search for a heavy photon using the engineering run data.

Synthesis, structure characterization and biological studies on a new aromatic hydrazone, 5-(2-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)hydrazono)-2,2-dimethyl-1,3-dioxane-4,6-dione, and its transition metal complexes

NASA Astrophysics Data System (ADS)

Kumar, Shubha S.; Biju, S.; Sadasivan, V.

2018-03-01

A new aromatic hydrazone 5-(2-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)hydrazono)-2,2-dimethyl-1,3-dioxane-4,6-dione has been synthesized by Japp-Klingemann reaction from diazotized 4-aminoantipyrine and Meldrum's acid. A few 3d-metal ion complexes of this hydrazone were synthesized. The compound and its complexes were characterized by UV-Visible, 1H NMR, ESR, Mass spectral, molar conductance and magnetic susceptibility measurements. The compound was found to exist in hydrazone form in solid state and solution from SXRD and 1H NMR study. The influence of pH on the molecule was studied and found that it shows azo/enol-hydrazone tautomerism in solution. This molecule act as a univalent tridentate ligand and the complexes were assigned to have a 1:2 stoichiometry (M:L). The antioxidant properties of the compounds were explored by DPPH assay and found that the ligand possesses better free radical scavenging effect than the complexes. Antimicrobial activities of these compounds were investigated and were found to be active.

Kinetic and structural studies reveal a unique binding mode of sulfite to the nickel center in urease.

PubMed

Mazzei, Luca; Cianci, Michele; Benini, Stefano; Bertini, Leonardo; Musiani, Francesco; Ciurli, Stefano

2016-01-01

Urease is the most efficient enzyme known to date, and catalyzes the hydrolysis of urea using two Ni(II) ions in the active site. Urease is a virulence factor in several human pathogens, while causing severe environmental and agronomic problems. Sporosarcina pasteurii urease has been used extensively in the structural characterization of the enzyme. Sodium sulfite has been widely used as a preservative in urease solutions to prevent oxygen-induced oxidation, but its role as an inhibitor has also been suggested. In the present study, isothermal titration microcalorimetry was used to establish sulfite as a competitive inhibitor for S. pasteurii urease, with an inhibition constant of 0.19mM at pH7. The structure of the urease-sulfite complex, determined at 1.65Å resolution, shows the inhibitor bound to the dinuclear Ni(II) center of urease in a tridentate mode involving bonds between the two Ni(II) ions in the active site and all three oxygen atoms of the inhibitor, supporting the observed competitive inhibition kinetics. This coordination mode of sulfite has never been observed, either in proteins or in small molecule complexes, and could inspire synthetic coordination chemists as well as biochemists to develop urease inhibitors based on this chemical moiety. Copyright © 2015 Elsevier Inc. All rights reserved.

MicroRNAs form triplexes with double stranded DNA at sequence-specific binding sites; a eukaryotic mechanism via which microRNAs could directly alter gene expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paugh, Steven W.; Coss, David R.; Bao, Ju

MicroRNAs are important regulators of gene expression, acting primarily by binding to sequence-specific locations on already transcribed messenger RNAs (mRNA). Recent studies indicate that microRNAs may also play a role in up-regulating mRNA transcription levels, although a definitive mechanism has not been established. Double-helical DNA is capable of forming triple-helical structures through Hoogsteen and reverse Hoogsteen interactions in the major groove of the duplex, and we show physical evidence that microRNAs form triple-helical structures with duplex DNA, and identify microRNA sequences that favor triplex formation. We developed an algorithm (Trident) to search genome-wide for potential triplex-forming sites and show thatmore » several mammalian and non-mammalian genomes are enriched for strong microRNA triplex binding sites. We show that those genes containing sequences favoring microRNA triplex formation are markedly enriched (3.3 fold, p<2.2 x 10 -16) for genes whose expression is positively correlated with expression of microRNAs targeting triplex binding sequences. As a result, this work has thus revealed a new mechanism by which microRNAs can interact with gene promoter regions to modify gene transcription.« less

Mechanisms of Alizarin Red S and Methylene blue biosorption onto olive stone by-product: Isotherm study in single and binary systems.

PubMed

Albadarin, Ahmad B; Mangwandi, Chirangano

2015-12-01

The biosorption process of anionic dye Alizarin Red S (ARS) and cationic dye methylene blue (MB) as a function of contact time, initial concentration and solution pH onto olive stone (OS) biomass has been investigated. Equilibrium biosorption isotherms in single and binary systems and kinetics in batch mode were also examined. The kinetic data of the two dyes were better described by the pseudo second-order model. At low concentration, ARS dye appeared to follow a two-step diffusion process, while MB dye followed a three-step diffusion process. The biosorption experimental data for ARS and MB dyes were well suited to the Redlich-Peterson isotherm. The maximum biosorption of ARS dye, qmax = 16.10 mg/g, was obtained at pH 3.28 and the maximum biosorption of MB dye, qmax = 13.20 mg/g, was observed at basic pH values. In the binary system, it was indicated that the MB dye diffuses firstly inside the biosorbent particle and occupies the biosorption sites forming a monodentate complex and then the ARS dye enters and can only bind to untaken sites; forms a tridentate complex with OS active sites. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structural diversity of benzil bis(benzoylhydrazone): Mononuclear, binuclear and trinuclear complexes.

PubMed

López-Torres, Elena; Mendiola, M Antonia

2009-10-07

The coordination behaviour of the Schiff-base, benzil bis(benzoylhydrazone), LH(2) towards divalent nickel, lead, cadmium, zinc and copper ions has been investigated. The complexes have been fully characterized by techniques including (113)Cd and (207)Pb NMR, as well as (13)C and (113)Cd CP/MAS NMR and by single crystal X-ray diffraction. All the complexes have the general formula [ML](n) (n = 1-3 depending on the metal ion), with the ligand doubly deprotonated. The nickel complex [NiL] is a monomeric compound, the lead complex [PbL](2) shows a binuclear structure, whereas zinc [ZnL](3) and copper [CuL](3) complexes are trinuclear helicates. The cadmium complex seems to be a dimer with a structure similar to that of . In the nickel and lead derivatives, the ligand behaves as a tetradentate N(2)O(2) chelate and in complex also as a bridge through one of the O atoms. In the crystal structures of Zn and Cu complexes [ML](3) each metal is in a pentadentate N(3)O(2) environment formed by two different ligands, one tridentate chelate and the other bidentate chelate, giving rise to trinuclear helicates. These results point out the versatility of benzil bis(benzoylhydrazone) on its coordination.

On-site detection of stacked genetically modified soybean based on event-specific TM-LAMP and a DNAzyme-lateral flow biosensor.

PubMed

Cheng, Nan; Shang, Ying; Xu, Yuancong; Zhang, Li; Luo, Yunbo; Huang, Kunlun; Xu, Wentao

2017-05-15

Stacked genetically modified organisms (GMO) are becoming popular for their enhanced production efficiency and improved functional properties, and on-site detection of stacked GMO is an urgent challenge to be solved. In this study, we developed a cascade system combining event-specific tag-labeled multiplex LAMP with a DNAzyme-lateral flow biosensor for reliable detection of stacked events (DP305423× GTS 40-3-2). Three primer sets, both event-specific and soybean species-specific, were newly designed for the tag-labeled multiplex LAMP system. A trident-like lateral flow biosensor displayed amplified products simultaneously without cross contamination, and DNAzyme enhancement improved the sensitivity effectively. After optimization, the limit of detection was approximately 0.1% (w/w) for stacked GM soybean, which is sensitive enough to detect genetically modified content up to a threshold value established by several countries for regulatory compliance. The entire detection process could be shortened to 120min without any large-scale instrumentation. This method may be useful for the in-field detection of DP305423× GTS 40-3-2 soybean on a single kernel basis and on-site screening tests of stacked GM soybean lines and individual parent GM soybean lines in highly processed foods. Copyright © 2017 Elsevier B.V. All rights reserved.

Monometallic Ni(0) and Heterobimetallic Ni(0) /Au(I) Complexes of Tripodal Phosphine Ligands: Characterization in Solution and in the Solid State and Catalysis.

PubMed

Cluff, Kyle J; Bhuvanesh, Nattamai; Blümel, Janet

2015-07-06

The tridentate chelate nickel complexes [(CO)Ni{(PPh2 CH2 )3 CMe}] (2), [(CO)Ni{(PPh2 CH2 CH2 )3 SiMe}] (6), and [Ph3 PNi{(PPh2 CH2 CH2 )3 SiMe}] (7), as well as the bidentate complex [(CO)2 Ni{(PPh2 CH2 )2 CMeCH2 PPh2 }] (3) and the heterobimetallic complex [(CO)2 Ni{(PPh2 CH2 )2 CMeCH2 Ph2 PAuCl}] (4), have been synthesized and fully characterized in solution. All (1) H and (13) C NMR signal assignments are based on 2D-NMR methods. Single crystal X-ray structures have been obtained for all complexes. Their (31) P CP/MAS (cross polarization with magic angle spinning) NMR spectra have been recorded and the isotropic lines identified. The signals were assigned with the help of their chemical shift anisotropy (CSA) data. All complexes have been tested regarding their catalytic activity for the cyclotrimerization of phenylacetylene. Whereas complexes 2-4 display low catalytic activity, complex 7 leads to quantitative conversion of the substrate within four hours and is highly selective throughout the catalytic reaction. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structurally related hydrazone-based metal complexes with different antitumor activities variably induce apoptotic cell death.

PubMed

Megger, Dominik A; Rosowski, Kristin; Radunsky, Christian; Kösters, Jutta; Sitek, Barbara; Müller, Jens

2017-04-05

Three new complexes bearing the tridentate hydrazone-based ligand 2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)pyridine (L) were synthesized and structurally characterized. Biological tests indicate that the Zn(ii) complex [ZnCl 2 (L)] is of low cytotoxicity against the hepatocellular carcinoma cell line HepG2. In contrast, the Cu(ii) and Mn(ii) complexes [CuCl 2 (L)] and [MnCl 2 (L)] are highly cytotoxic with EC 50 values of 1.25 ± 0.01 μM and 20 ± 1 μM, respectively. A quantitative proteome analysis reveals that treatment of the cells with the Cu(ii) complex leads to a significantly altered abundance of 102 apoptosis-related proteins, whereas 38 proteins were up- or down-regulated by the Mn(ii) complex. A closer inspection of those proteins regulated only by the Cu(ii) complex suggests that the superior cytotoxic activity of this complex is likely to be related to an initiation of the caspase-independent cell death (CICD). In addition, an increased generation of reactive oxygen species (ROS) and a strong up-regulation of proteins responsive to oxidative stress suggest that alterations of the cellular redox metabolism likely contribute to the cytotoxicity of the Cu(ii) complex.

Syntheses, crystal structures and Hirshfeld surface analysis of a coordination polymer of Cu(II) chlorido and a tris-octahedral complex of Ni(II) containing isonicotinoylhydrazone blockers

NASA Astrophysics Data System (ADS)

Mahmoudi, Ghodrat; Chowdhury, Habibar; Ghosh, Barindra K.; Lofland, Samuel E.; Maniukiewicz, Waldemar

2018-05-01

One-pot reactions of pre-assigned molar ratios of appropriate metal (II) salts and HL1 (2-acetylpyridine nicotinoylhydrazone) or HL2 (2-acetylpyridine isonicotinoylhydrazone) in MeOH solutions at room temperature afford 1D coordination polymeric chain [Cu(μ-L1) (Cl)]n (1) and a mononuclear complex [Ni(L2)2] (2). The compounds (1) and (2) were characterized using elemental analyses, spectral and other physicochemical methods. Single crystal X-ray diffraction measurements for (1) and (2) have been made to define the molecular aggregates and crystalline architectures. In (1), each copper (II) center adopts a distorted square pyramidal geometry with a CuN3OCl chromophore linked through μ-L1 to form the 1D polymeric chain. While in (2) each Ni(II) cation is six-coordinate with octahedral structure having NiN4O2 chromophore containing two L2 units each functioning as a classical tridentate (N,N,O) chelator. Different weak non-covalent interactions promote dimensionalities in the compounds. A Hirshfeld surface analysis was employed to gain additional insight into interactions responsible for packing of (1) and (2). Magnetic susceptibility measurement of (1) in the 4-300 K range reveals simple paramagnetism.

Interaction of the HIV NCp7 Protein with Platinum(II) and Gold(III) Complexes Containing Tridentate Ligands.

PubMed

Bernardes, Victor H F; Qu, Yun; Du, Zhifeng; Beaton, James; Vargas, Maria D; Farrell, Nicholas P

2016-11-07

The human immunodeficiency virus (HIV) nucleocapsid protein (NCp7) plays significant roles in the virus life cycle and has been targeted by compounds that could lead to its denaturation or block its interaction with viral RNA. Herein, we describe the interactions of platinum(II) and gold(III) complexes with NCp7 and how the reactivity/affinity of potential inhibitors can be modulated by judicious choice of ligands. The interactions of [MCl(N 3 )] n+ (M = Pt 2+ (n = 1) and Au 3+ (n = 2); N 3 = tridentate chelate ligands: bis(2-pyridylmethyl)methylamine (Mebpma, L 1 ) and bis(2-pyridylmethyl)amine (bpma, L 2 ) with the C-terminal zinc finger of NCp7 (ZF2) were investigated by electrospray ionization-mass spectroscopy (ESI-MS). Mass spectra from the incubation of [MCl(Mebpma)] n+ complexes (PtL 1 and AuL 1 ) with ZF2 indicated that they were more reactive than the previously studied diethylenetriamine-containing analogues [MCl(dien)] n+ . The initial product of reaction of PtL 1 with ZF2 results in loss of all ligands and release of zinc to give the platinated apopeptide {PtF} (F = apopeptide). This is in contrast to the incubation with [PtCl(dien)] + , in which {Pt(dien)}-peptide adducts are observed. Incubation of the Au 3+ complex AuL 1 with ZF2 gave Au x F n+ species (x = 1, 2, 4, F = apopeptide) again with loss of all ligands. Furthermore, the formally substitution-inert analogues [Pt(N 3 )L] 2+ (L = 4-methylpyridine (4-pic), 4-dimethylaminopyridine (dmap), and 9-ethylguanine (9-EtGua)) were prepared to examine stacking interactions with N-acetyltryptophan (N-AcTrp), the Trp-containing ZF2, and the "full" two-finger NCp7 itself using fluorescence quenching titration. Use of bpma and Mebpma gave slightly higher affinity than analogous [Pt(dien)L)] 2+ complexes. The dmap-containing complexes (PtL 1 a and PtL 2 a) had the greatest association constants (K a ) for N-AcTrp and ZF2 peptide. The complex PtL 1 a had the highest K a when compared with other known Pt 2+ analogues: [Pt(dien)(9-EtGua)] 2+ < [Pt(bpma)(9-EtGua)] 2+ < [Pt(dien)(dmap)] 2+ < PtL 2 a < PtL 1 a. A K a value of ca. 40.6 ± 1.0 × 10 3 M -1 was obtained for the full NCp7 peptide with PtL 1 a. In addition, the mass spectrum of the interaction between ZF2 and PtL 1 a confirms formation of a 1:1 PtL 1 a/ZF2 adduct. The reactivity of selected complexes with sulfur-containing amino acid N-acetylcysteine (N-AcCys) was also investigated by 195 Pt and 1 H NMR spectroscopy and ESI-MS. The precursor compounds [PtCl(N 3 )] + PtL 1 and PtL 2 reacted readily, whereas their [Pt(N 3 )L] 2+ analogues PtL 1 a and PtL 2 a were inert to substitution.

AmeriFlux US-Me2 Metolius-intermediate aged ponderosa pine

DOE Data Explorer

Law, Bev [Oregon State University

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-Me2 Metolius-intermediate aged ponderosa pine. Site Description - The mean stand age is 64 years old and the stand age of the oldest trees is about 100 years old. This site is one of the Metolius cluster sites with different age and disturbance classes and part of the AmeriFlux network (http://ameriflux.ornl.gov/fullsiteinfo.php?sid=88). The overstory is almost exclusively composed of ponderosa pine trees (Pinus ponderosa Doug. Ex P. Laws) with a few scattered incense cedars (Calocedrus decurrens (Torr.) Florin) and has a peak leaf area index (LAI) of 2.8 m2 m-2. Tree height is relatively homogeneous at about 16 m, and the mean tree density is approximately 325 trees ha-1 (Irvine et al., 2008). The understory is sparse with an LAI of 0.2 m2 m-2 and primarily composed of bitterbrush (Purshia tridentate (Push) DC.) and Manzanita (Arctostaphylos patula Greene). Soils at the site are sandy (69%/24%/7% sand/silt/clay at 0–0.2 m depth and 66%/27%/7% at 0.2–0.5 m depth, and 54%/ 35%/11% at 0.5–1.0 m depth), freely draining with a soil depth of approximately 1.5 m (Irvine et al., 2008; Law et al., 2001b; Schwarz et al., 2004).

Experimental and theoretical investigation of [Al(PCr)(H2O)] complex in aqueous solution

NASA Astrophysics Data System (ADS)

Tenório, Thaís; Lopes, Damiana C. N.; Silva, Andréa M.; Ramos, Joanna Maria; Buarque, Camilla D.

2014-01-01

Phosphocreatine is a phosphorylated creatine molecule synthesized in the liver and transported to muscle cells where it is used for the temporary storage of energy. In Alzheimer's disease, the capture of glucose by cells is impaired, which negatively affects the Krebs cycle, leading to problems with the generation of phosphocreatine. Furthermore, the creatine-phosphocreatine system, regulated by creatine kinase, is affected in the brains of Alzheimer's disease patients. Aluminum ions are associated with Alzheimer's disease. Al(III) decreases cell viability and increases the fluidity of the plasma membrane, profoundly altering cell morphology. In this study, one of the complexes formed by Al(III) and phosphocreatine in aqueous solution was investigated by potentiometry, 31P and 27Al NMR, Raman spectroscopy and density functional theory (DFT) calculations. The log KAlPCr value was 11.37 ± 0.03. Phosphocreatine should act as a tridentate ligand in this complex. The 27Al NMR peak at 48.92 ppm indicated a tetrahedral molecule. The fourth position in the arrangement was occupied by a coordinated water molecule. Raman spectroscopy, 31P NMR and DFT calculations (DFT:B3LYP/6-311++G**) indicated that the donor atoms are oxygen in the phosphate group, the nitrogen of the guanidine group and the oxygen of the carboxylate group. Mulliken charges, NBO charges, frontier molecular orbitals, electrostatic potential contour surfaces and mapped electrostatic potential were also examined.

Implementing non-invasive prenatal testing for aneuploidy in a national healthcare system: global challenges and national solutions.

PubMed

van Schendel, Rachèl V; van El, Carla G; Pajkrt, Eva; Henneman, Lidewij; Cornel, Martina C

2017-09-19

Since the introduction of non-invasive prenatal testing (NIPT) in 2011, mainly by commercial companies, a growing demand for NIPT from the public and healthcare professionals has been putting pressure on the healthcare systems of various countries. This study identifies the challenges of establishing a responsible implementation of NIPT for aneuploidy in prenatal healthcare, by looking at the Netherlands. A mixed methods approach involving 13 stakeholder interviews, document analysis and (participatory) observations of the Dutch NIPT Consortium meetings were used. The Diffusion of Innovation Theory and a Network of Actors model were used to interpret the findings. Implementation of NIPT was facilitated by several factors. The set-up of a national NIPT Consortium enabled discussion and collaboration between stakeholders. Moreover, it led to the plan to offer NIPT through a nationwide research setting (TRIDENT studies), which created a learning phase for careful implementation. The Dutch legal context was perceived as a delaying factor, but eventually gave room for the parties involved to organise themselves and their practices. This study shows that implementing advanced technologies with profound effects on prenatal care benefit from a learning phase that allows time to carefully evaluate the technical performance and women's experiences and to enable public debate. Such a coordinated learning phase, involving all stakeholders, will stimulate the process of responsible and sustainable implementation.

MicroRNAs Form Triplexes with Double Stranded DNA at Sequence-Specific Binding Sites; a Eukaryotic Mechanism via which microRNAs Could Directly Alter Gene Expression

PubMed Central

Grace, Christy R.; Ferreira, Antonio M.; Waddell, M. Brett; Ridout, Granger; Naeve, Deanna; Leuze, Michael; LoCascio, Philip F.; Panetta, John C.; Wilkinson, Mark R.; Pui, Ching-Hon; Naeve, Clayton W.; Uberbacher, Edward C.; Bonten, Erik J.; Evans, William E.

2016-01-01

MicroRNAs are important regulators of gene expression, acting primarily by binding to sequence-specific locations on already transcribed messenger RNAs (mRNA) and typically down-regulating their stability or translation. Recent studies indicate that microRNAs may also play a role in up-regulating mRNA transcription levels, although a definitive mechanism has not been established. Double-helical DNA is capable of forming triple-helical structures through Hoogsteen and reverse Hoogsteen interactions in the major groove of the duplex, and we show physical evidence (i.e., NMR, FRET, SPR) that purine or pyrimidine-rich microRNAs of appropriate length and sequence form triple-helical structures with purine-rich sequences of duplex DNA, and identify microRNA sequences that favor triplex formation. We developed an algorithm (Trident) to search genome-wide for potential triplex-forming sites and show that several mammalian and non-mammalian genomes are enriched for strong microRNA triplex binding sites. We show that those genes containing sequences favoring microRNA triplex formation are markedly enriched (3.3 fold, p<2.2 × 10−16) for genes whose expression is positively correlated with expression of microRNAs targeting triplex binding sequences. This work has thus revealed a new mechanism by which microRNAs could interact with gene promoter regions to modify gene transcription. PMID:26844769

Synthesis, spectroscopic, thermogravimetric and antimicrobial studies of mixed ligands complexes

NASA Astrophysics Data System (ADS)

Mahmoud, Walaa H.; Mahmoud, Nessma F.; Mohamed, Gehad G.; El-Sonbati, Adel Z.; El-Bindary, Ashraf A.

2015-09-01

An interesting series of mixed ligand complexes have been synthesized by the reaction of metal chloride with guaifenesin (GFS) in the presence of 2-aminoacetic acid (HGly) (1:1:1 molar ratio). The elemental analysis, magnetic moments, molar conductance, spectral (UV-Vis, IR, 1H NMR and ESR) and thermal studies were used to characterize the isolated complexes. The molecular structure of GFS is optimized theoretically and the quantum chemical parameters are calculated. The IR showed that the ligand (GFS) acts as monobasic tridentate through the hydroxyl, phenoxy etheric and methoxy oxygen atoms and co-ligand (HGly) as monobasic bidentate through the deprotonated carboxylate oxygen atom and nitrogen atom of amino group. The molar conductivities showed that all the complexes are non-electrolytes except Cr(III) complex is electrolyte. Electronic and magnetic data proposed the octahedral structure for all complexes under investigation. ESR spectrum for Cu(II) revealed data which confirm the proposed structure. Antibacterial screening of the compounds were carried out in vitro on gram positive (Bacillus subtilis and Staphylococcus aureus), gram negative (Escherichia coli and Neisseria gonorrhoeae) bacteria and for in vitro antifungal activity against Candida albicans organism. However, some complexes showed more chemotherapeutic efficiency than the parent GFS drug. The complexes were also screened for their in vitro anticancer activity against the breast cell line (MFC7) and the results obtained showed that they exhibit a considerable anticancer activity.

Synthesis, structure, DNA/BSA binding and antibacterial studies of NNO tridentate Schiff base metal complexes

NASA Astrophysics Data System (ADS)

Sakthi, Marimuthu; Ramu, Andy

2017-12-01

A new salicylaldehyde derived 2,4-diiodo-6-((2-phenylaminoethylimino)methyl)phenol Schiff base(L) and its transition metal complexes of the type MLCl where, M = Cu(II), Ni(II), Co(II), Mn(II) and Zn(II) have been synthesized. The coordination mode of Schiff base holding NNO donor atoms with metal ions was well investigated by elemental analysis, ESI-mass as well as IR, UV-vis, CV and NMR spectral studies. The binding efficiency and mode of these complexes with biological macromolecules viz., herring sperm DNA (HS- DNA) and bovine serum albumin (BSA) have been explored through various spectroscopic techniques. The characteristic changes in absorption, emission and, circular dichroism spectra of the complexes with DNA indicate the noticeable interaction between them. From the all spectral information complexes could interact with DNA via non-intercalation mode of binding. The hyperchromisim in absorption band and hypochromisim in emission intensity of BSA with different complex concentrations shown significant information, and the binding affinity value has been predicted from Stern-Volmer plots. Further, all the complexes could cleave the circular plasmid pUC19 DNA efficiently by using an activator H2O2. The ligand and all metal(II) complexes showed good antibacterial activities. The molecular docking studies of the complexes with DNA were performed in order to make a comparison and conclusion with spectral technic results.

Synthesis, spectral characterization and computed optical analysis of potent triazole based compounds

NASA Astrophysics Data System (ADS)

Sumrra, Sajjad H.; Mushtaq, Fazila; Khalid, Muhammad; Raza, Muhammad Asam; Nazar, Muhammad Faizan; Ali, Bakhat; Braga, Ataualpa A. C.

2018-02-01

Biologically active triazole Schiff base ligand (L) and metal complexes [Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)] are reported herein. The ligand acted as tridentate and coordinated towards metallic ions via azomethine-N, triazolic-N moiety and deprotonated-O of phenyl substituents in an octahedral manner. These compounds were characterized by physical, spectral and analytical analysis. The synthesized ligand and metal complexes were screened for antibacterial pathogens against Chromohalobacter salexigens, Chromohalobacter israelensi, Halomonas halofila and Halomonas salina, antifungal bioassay against Aspergillus niger and Aspergellus flavin, antioxidant (DPPH, phosphomolybdate) and also for enzyme inhibition [butyrylcholinesterase (BChE) and acetylcholinesterase (AChE)] studies. The results of these activities indicated the ligand to possess potential activity which significantly increased upon chelation. Moreover, vibrational bands, frontier molecular orbitals (FMOs) and natural bond analysis (NBO) of ligand (1) were carried out through density functional theory (DFT) with B3lYP/6-311 ++G (d,p) approach. While, UV-Vis analysis was performed by time dependent TD-DFT with B3lYP/6-311 ++G (d,p) method. NBO analysis revealed that investigated compound (L) contains enormous molecular stability owing to hyper conjugative interactions. Theoretical spectroscopic findings showed good agreement to experimental spectroscopic data. Global reactivity descriptors were calculated using the energies of FMOs which indicated compound (L) might be bioactive. These parameters confirmed the charge transfer phenomenon and reasonable correspondence with experimental bioactivity results.

Nonentrained circadian rhythms of melatonin in submariners scheduled to an 18-hour day.

PubMed

Kelly, T L; Neri, D F; Grill, J T; Ryman, D; Hunt, P D; Dijk, D J; Shanahan, T L; Czeisler, C A

1999-06-01

The human circadian timing system has previously been shown to free run with a period slightly longer than 24 h in subjects living in the laboratory under conditions of forced desynchrony. In forced desynchrony, subjects are shielded from bright light and periodic time cues and are required to live on a day length outside the range of circadian entrainment. The work schedule used for most personnel aboard American submarines is 6 h on duty alternating with 12 h off duty. This imposed 18-h cycle is too short for human circadian synchronization, especially given that there is no bright-light exposure aboard submarines. However, crew members are exposed to 24-h stimuli that could mediate synchronization, such as clocks and social contacts with personnel who are living on a 24-h schedule. The authors investigated circadian rhythms of salivary melatonin in 20 crew members during a prolonged voyage on a Trident nuclear submarine. The authors found that in crew members living on the 18-h duty cycle, the endogenous rhythm of melatonin showed an average period of 24.35 h (n = 12, SD = 0.18 h). These data indicate that social contacts and knowledge of clock time are insufficient for entrainment to a 24-h period in personnel living by an 18-h rest-activity cycle aboard a submarine.

The application of chiroptical spectroscopy (circular dichroism) in quantifying binding events in lanthanide directed synthesis of chiral luminescent self-assembly structures† †Electronic supplementary information (ESI) available. CCDC 999267–999270 and 1026036. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4sc02474e Click here for additional data file. Click here for additional data file.

PubMed Central

Blasco, Salvador; Twamley, Brendan; O'Brien, John; Peacock, Robert D.; Kitchen, Jonathan A.; Martínez-Calvo, Miguel

2015-01-01

The binding of asymmetrical and optically pure tridentate ligands (L = 1(S) and 1(R)) containing one carboxylic group and 2-naphthyl as an antenna to lanthanide ions (M = La(iii) and Eu(iii)) was studied in CH3CN, showing the successive formation of M:L, M:L2 and M:L3 stoichiometric species in solution. The europium complexes EuL3 were also synthesised, structurally characterised and their photophysical properties probed in CH3OH and CH3CN. The changes in the chiroptical properties of both 1(S) and 1(R) were used (by circular dichroism (CD) spectroscopy) to monitor the formation of these chiral self-assemblies in solution. While circularly polarised luminescence (CPL) showed the formation of Eu(1(S))3 and Eu(1(R))3 as enantiomers, with high luminescence dissymmetry factors (g lum), fitting the CD changes allowed for binding constants to be determined that were comparable to those seen in the analyses of absorbance and luminescence changes. PMID:28936303

Safety and pharmacokinetics of the oral iron chelator SP-420 in β-thalassemia.

PubMed

Taher, Ali T; Saliba, Antoine N; Kuo, Kevin H; Giardina, Patricia J; Cohen, Alan R; Neufeld, Ellis J; Aydinok, Yesim; Kwiatkowski, Janet L; Jeglinski, Brenda I; Pietropaolo, Keith; Berk, Gregory; Viprakasit, Vip

2017-12-01

Our phase I, open-label, multi-center, dose-escalation study evaluated the pharmacokinetics (PK) of SP-420, a tridentate oral iron chelating agent of the desferrithiocin class, in patients with transfusion dependent β-thalassemia. SP-420 was administered as a single dose of 1.5 (n = 3), 3 (n = 3), 6 (n = 3), 12 (n = 3), and 24 (n = 6) mg/kg or as a twice-daily dose of 9 mg/kg (n = 6) over 14-28 days. There was a near dose-linear increase in the mean plasma SP-420 concentrations and in the mean values for C max and AUC 0-τ over the dose range evaluated. The median t max ranged from 0.5 to 2.25 h and was not dose dependent. The study was prematurely terminated by the sponsor due to renal adverse events (AE) including proteinuria, increase in serum creatinine, and one case of Fanconi syndrome. Other adverse effects included hypersensitivity reactions and gastrointestinal disturbances. Based on current dose administration, the renal AE observed outweighed the possible benefits from chelation therapy. However, additional studies assessing efficacy and safety of lower doses or less frequent dosing of SP-420 over longer durations with close monitoring would be necessary to better explain the findings of our study and characterize the safety of the study drug. © 2017 Wiley Periodicals, Inc.

Molecular structure and biological studies on Cr(III), Mn(II) and Fe(III) complexes of heterocyclic carbohydrazone ligand.

PubMed

Abu El-Reash, G M; El-Gammal, O A; Radwan, A H

2014-01-01

The chelating behavior of the ligand (H2APC) based on carbohydrazone core modified with pyridine end towards Cr(III), Mn(II) and Fe(III) ions have been examined. The (1)H NMR and IR data for H2APC revealed the presence of two stereoisomers syn and anti in both solid state and in solution in addition to the tautomeric versatility based on the flexible nature of the hydrazone linkage leading to varied coordination modes. The spectroscopic data confirmed that the ligand behaves as a monobasic tridentate in Cr(III) and Fe(III) complexes and as neutral tetradentate in Mn(II) complex. The electronic spectra as well as the magnetic measurements confirmed the octahedral geometry for all complexes. The bond length and angles were evaluated by DFT method using material studio program for all complexes. The thermal behavior and the kinetic parameters of degradation were determined using Coats-Redfern and Horowitz-Metzger methods. The antioxidant (DDPH and ABTS methods), anti-hemolytic and cytotoxic activities of the compounds have been screened. Cr(III) complex and H2APC showed the highest antioxidant activity using ABTS and DPPH methods. With respect to in vitro Ehrlich ascites assay, H2APC exhibited the potent activity followed by Fe(III) and Cr(III)complexes. Copyright © 2013 Elsevier B.V. All rights reserved.

Development and characterization of a 99m Tc-tricarbonyl-labelled estradiol derivative obtained by "Click Chemistry" with potential application in estrogen receptors imaging.

PubMed

Tejería, María Emilia; Giglio, Javier; Dematteis, Silvia; Rey, Ana

2017-09-01

Assessment of the presence of estrogen receptors in breast cancer is crucial for treatment planning. With the objective to develop a potential agent for estrogen receptors imaging, we present the development and characterization of a 99m Tc-tricarbonyl-labelled estradiol derivative. Using ethinylestradiol as starting material, an estradiol derivative bearing a 1,4-disubstituted 1,2,3-triazole-containing tridentate ligand system was synthesized by "Click Chemistry" and fully characterized. Labelling with high yield and radiochemical purity was achieved through the formation of a 99m Tc-tricarbonyl complex. The radiolabelled compound was stable, exhibited moderate binding to plasma protein (approximately 33%) and lipophilicity in the adequate range (logP 1.3 ± 0.1 at pH 7.4). Studies in MCF7 showed promising uptake values (approximately 2%). However, more than 50% of the activity is quickly released from the cell. Biodistribution experiments in normal rats confirmed the expected "in vivo" stability of the radiotracer but showed very high gastrointestinal and liver activity, which is inconvenient for in vivo applications. Taking into consideration the well-documented influence of the chelating system in the physicochemical and biological behaviour of technetium-labelled small biomolecules, research will be continued using the same pharmacophore but different complexation modalities of technetium. Copyright © 2017 John Wiley & Sons, Ltd.

Galanthamine, an anticholinesterase drug, effects plant growth and development in Artemisia tridentate Nutt. via modulation of auxin and neutrotransmitter signaling.

PubMed

Turi, Christina E; Axwik, Katarina E; Smith, Anderson; Jones, A Maxwell P; Saxena, Praveen K; Murch, Susan J

2014-01-01

Galanthamine is a naturally occurring acetylcholinesterase (AchE) inhibitor that has been well established as a drug for treatment of mild to moderate Alzheimer disease, but the role of the compound in plant metabolism is not known. The current study was designed to investigate whether galanthamine could redirect morphogenesis of Artemisia tridentata Nutt. cultures by altering concentration of endogenous neurosignaling molecules acetylcholine (Ach), auxin (IAA), melatonin (Mel), and serotonin (5HT). Exposure of axenic A. tridentata cultures to 10 µM galanthamine decreased the concentration of endogenous Ach, IAA, MEL, and AchE, and altered plant growth in a manner reminiscent of 2-4D toxicity. Galanthamine itself demonstrated IAA activity in an oat coleotile elongation bioassay, 20 µM galanthamine showed no significant difference compared with 5 μM IAA or 5 μM 1-Naphthaleneacetic acid (NAA). Metabolomic analysis detected between 20,921 to 27,891 compounds in A. tridentata plantlets and showed greater commonality between control and 5 µM treatments. Furthermore, metabolomic analysis putatively identified coumarins scopoletin/isoscopoletin, and scopolin in A. tridentata leaf extracts and these metabolites linearly increased in response to galanthamine treatments. Overall, these data indicate that galanthamine is an allelopathic phytochemical and support the hypothesis that neurologically active compounds in plants help ensure plant survival and adaptation to environmental challenges.

Cobalt(II) complexes with azole-pyridine type ligands for non-aqueous redox-flow batteries: Tunable electrochemistry via structural modification

NASA Astrophysics Data System (ADS)

Armstrong, Craig G.; Toghill, Kathryn E.

2017-05-01

A single species redox flow battery employing a new class of cobalt(II) complexes with 'tunable' tridentate azole-pyridine type ligands is reported. Four structures were synthesised and their electrochemical, physical and battery characteristics were investigated as a function of successive substitution of the ligand terminal pyridyl donors. The Co(II/I) and Co(III/II) couples are stable and quasi-reversible on gold and glassy carbon electrodes, however redox potentials are tunable allowing the cobalt potential difference to be preferentially increased from 1.07 to 1.91 V via pyridine substitution with weaker σ-donating/π-accepting 3,5-dimethylpyrazole groups. The charge-discharge properties of the system were evaluated using an H-type glass cell and graphite rod electrodes. The complexes delivered high Coulombic efficiencies of 89.7-99.8% and very good voltaic efficiencies of 70.3-81.0%. Consequently, energy efficiencies are high at 63.1-80.8%, marking an improvement on other similar non-aqueous systems. Modification of the ligands also improved solubility from 0.18 M to 0.50 M via pyridyl substitution with 3,5-dimethylpyrazole, though the low solubility of the complexes limits the overall energy capacity to between 2.58 and 12.80 W h L-1. Preliminary flow cell studies in a prototype flow cell are also demonstrated.

Synthesis and characterization of fac-Re(CO)3-aspartic-N-monoacetic acid, a structural analogue of a potential new renal tracer, fac-99mTc(CO)3(ASMA).

PubMed

Klenc, Jeffrey; Lipowska, Malgorzata; Taylor, Andrew T; Marzilli, Luigi G

2012-09-01

The reaction of an aminopolycarboxylate ligand, as partic- N - m onoacetic a cid (ASMA), with [Re(CO) 3 (H 2 O) 3 ] + was examined. The tridentate coordination of ASMA to this Re I tricarbonyl precursor yielded fac -Re(CO) 3 (ASMA) as a mixture of diastereomers. The chemistry is analogous to that of the Tc I tricarbonyl complex, which yields fac - 99m Tc(CO) 3 (ASMA) under similar conditions. The formation, structure, and isomerization of fac -Re(CO) 3 (ASMA) products were characterized by HPLC, 1 H NMR spectroscopy, and X-ray crystallography. The two major fac -Re(CO) 3 (ASMA) diastereomeric products each have a linear ONO coordination mode with two adjacent five-membered chelate rings, but they differ in the endo or exo orientation of the uncoordinated acetate group, in agreement with expectations based on previous studies. Conditions have been identified for the expedient isomerization of fac -Re(CO) 3 (ASMA) to a mixture consisting primarily of one major product. Because different isomeric species typically have different pharmacokinetic characteristics, these conditions may provide for the practical isolation of a single 99m Tc(CO) 3 (ASMA) species, thus allowing the isolation of the isomer that has optimal imaging and pharmacokinetic characteristics. This information will aid in the design of future 99m Tc radiopharmaceuticals.

Synthesis and characterization of fac-Re(CO)3-aspartic-N-monoacetic acid, a structural analogue of a potential new renal tracer, fac-99mTc(CO)3(ASMA)

PubMed Central

Klenc, Jeffrey; Lipowska, Malgorzata; Taylor, Andrew T.; Marzilli, Luigi G.

2013-01-01

The reaction of an aminopolycarboxylate ligand, aspartic-N-monoacetic acid (ASMA), with [Re(CO)3(H2O)3]+ was examined. The tridentate coordination of ASMA to this ReI tricarbonyl precursor yielded fac-Re(CO)3(ASMA) as a mixture of diastereomers. The chemistry is analogous to that of the TcI tricarbonyl complex, which yields fac-99mTc(CO)3(ASMA) under similar conditions. The formation, structure, and isomerization of fac-Re(CO)3(ASMA) products were characterized by HPLC, 1H NMR spectroscopy, and X-ray crystallography. The two major fac-Re(CO)3(ASMA) diastereomeric products each have a linear ONO coordination mode with two adjacent five-membered chelate rings, but they differ in the endo or exo orientation of the uncoordinated acetate group, in agreement with expectations based on previous studies. Conditions have been identified for the expedient isomerization of fac-Re(CO)3(ASMA) to a mixture consisting primarily of one major product. Because different isomeric species typically have different pharmacokinetic characteristics, these conditions may provide for the practical isolation of a single 99mTc(CO)3(ASMA) species, thus allowing the isolation of the isomer that has optimal imaging and pharmacokinetic characteristics. This information will aid in the design of future 99mTc radiopharmaceuticals. PMID:24273448

Synthesis, spectral, antitumor, antioxidant and antimicrobial studies on Cu(II), Ni(II) and Co(II) complexes of 4-[(1H-Benzoimidazol-2-ylimino)-methyl]-benzene-1,3-diol.

PubMed

El-wakiel, Nadia; El-keiy, Mai; Gaber, Mohamed

2015-08-05

A new Schiff base of 2-aminobenzimidazole with 2,4-dihydroybezaldehyde (H₃L), and its Cu(II), Ni(II) and Co(II) complexes have been synthesized and characterized by elemental analyses, molar conductance, thermal analysis (TGA), inductive coupled plasma (ICP), magnetic moment measurements, IR, EI-mass, UV-Vis. and ESR spectral studies. On the basis of spectral studies and analytical data, it is evident that the Schiff base acts as dibasic tridentate ligand coordinating via deprotonated OH, NH and azomethine nitrogen atom. The results showed that Co(II) and Ni(II) complexes have tetrahedral structure while Cu(II) complexes has octahedral geometry. The kinetic and thermodynamic parameters of the thermal decomposition stages have been evaluated. The studied complexes were tested for their in vitro antimicrobial activities against some bacterial strains. The anticancer activity of the ligand and its metal complexes is evaluated against human liver Carcinoma (HEPG2) cell. These compounds exhibited a moderate and weak activity against the tested HEPG2 cell lines with IC₅₀ of 9.08, 18.2 and 19.7 μg/ml for ligand, Cu(II) and Ni(II) complexes, respectively. In vitro antioxidant activity of the newly synthesized compounds has also been evaluated. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis, characterization, spectroscopic and theoretical studies of new zinc(II), copper(II) and nickel(II) complexes based on imine ligand containing 2-aminothiophenol moiety

NASA Astrophysics Data System (ADS)

Shafaatian, Bita; Mousavi, S. Sedighe; Afshari, Sadegh

2016-11-01

New dimer complexes of zinc(II), copper(II) and nickel(II) were synthesized using the Schiff base ligand which was formed by the condensation of 2-aminothiophenol and 2-hydroxy-5-methyl benzaldehyde. This tridentate Schiff base ligand was coordinated to the metal ions through the NSO donor atoms. In order to prevent the oxidation of the thiole group during the formation of Schiff base and its complexes, all of the reactions were carried out under an inert atmosphere of argon. The X-ray structure of the Schiff base ligand showed that in the crystalline form the SH groups were oxidized to produce a disulfide Schiff base as a new double Schiff base ligand. The molar conductivity values of the complexes in dichloromethane implied the presence of non-electrolyte species. The fluorescence properties of the Schiff base ligand and its complexes were also studied in dichloromethane. The products were characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis, and conductometry. The crystal structure of the double Schiff base was determined by single crystal X-ray diffraction. Furthermore, the density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d,p) level of theory for the determination of the optimized structures of Schiff base complexes.

Association between Chewing Side Preference and Dental Caries among Deciduous, Mixed and Permanent Dentition.

PubMed

Nayak, Ullal Anand; Sharma, Reena; Kashyap, Nilotpol; Prajapati, Deepesh; Kappadi, Damodar; Wadhwa, Saakshe; Gandotra, Shina; Yadav, Poonam

2016-09-01

Chewing Side Preference (CSP) is said to occur when mastication is recognized exclusively/consistently or predominantly on the same side of the jaw. It can be assessed by using the direct method - visual observation and indirect methods by electric programs, such as cinematography, kinetography and computerized electromyography. The present study was aimed at evaluating the prevalence of CSP in deciduous, mixed and permanent dentitions and relating its association with dental caries. In a cross-sectional observational study, 240 school going children aged 3 to 18years were randomly allocated to three experimental groups according to the deciduous dentition, mixed dentition and permanent dentition period. The existence of a CSP was determined using a direct method by asking the children to chew on a piece of gum (trident sugarless). The Mann Whitney U-test was used to compare the CSP and also among the boys and girls. The Spearman's Correlation Coefficient was used to correlate CSP and dental caries among the three study groups and also among the groups. CSP was observed in 69%, 83% and 76% of children with primary, mixed and permanent dentition respectively (p>0.05). There was no statistically significant association between the presence of CSP and dental caries among the three study groups. There was a weak or no correlation between gender and distribution of CSP and between presence of CSP and dental caries.

Photoinduced energy transfer in transition metal complex oligomers

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-04-01

The work we have done over the past three years has been directed toward the preparation, characterization and photophysical examination of mono- and bimetallic diimine complexes. The work is part of a broader project directed toward the development of stable, efficient, light harvesting arrays of transition metal complex chromophores. One focus has been the synthesis of rigid bis-bidentate and bis-tridentate bridging ligands. We have managed to make the ligand bphb in multigram quantities from inexpensive starting materials. The synthetic approach used has allowed us prepare a variety of other ligands which may have unique applications (vide infra). We have prepared,more » characterized and examined the photophysical behavior of Ru(II) and Re(I) complexes of the ligands. Energy donor/acceptor complexes of bphb have been prepared which exhibit nearly activationless energy transfer. Complexes of Ru(II) and Re(I) have also been prepared with other polyunsaturated ligands in which two different long lived ( > 50 ns) excited states exist; results of luminescence and transient absorbance measurements suggest the two states are metal-to-ligand charge transfer and ligand localized {pi}{r_arrow}{pi}* triplets. Finally, we have developed methods to prepare polymetallic complexes which are covalently bound to various surfaces. The long term objective of this work is to make light harvesting arrays for the sensitization of large band gap semiconductors. Details of this work are provided in the body of the report.« less

Synthesis, crystal structure and interaction of L-valine Schiff base divanadium(V) complex containing a V2O3 core with DNA and BSA.

PubMed

Guo, Qiong; Li, Lianzhi; Dong, Jianfang; Liu, Hongyan; Xu, Tao; Li, Jinghong

2013-04-01

A divanadium(V) complex, [V2O3(o-van-val)2] (o-van-val=Schiff base derived from o-vanillin and L-valine), has been synthesized and structurally characterized. The crystal structure shows that both of the vanadium centers in the complex have a distorted octahedral coordination environment composed of tridentate Schiff base ligand. A V2O3 core in molecular structure adopts intermediate between cis and trans configuration with the O1V1⋯V1AO1A torsion angle 115.22 (28)° and the V1⋯V1A distance 3.455Å. The binding properties of the complex with calf thymus DNA (CT-DNA) have been investigated by UV-vis absorption, fluorescence, CD spectra and viscosity measurement. The results indicate that the complex binds to CT-DNA in non-classical intercalative mode. Meanwhile, the interaction of the complex with bovine serum albumin (BSA) has been studied by UV-vis absorption, fluorescence and CD spectra. Results indicated that the complex can markedly quench the intrinsic fluorescence of BSA via a static quenching process, and cause its conformational change. The calculated apparent binding constant Kb was 1.05×10(6)M(-1) and the binding site number n was 1.18. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis, spectral and electrochemical studies of binuclear Ru(III) complexes containing dithiosemicarbazone ligand

NASA Astrophysics Data System (ADS)

Kanchana Devi, A.; Ramesh, R.

2014-01-01

Synthesis of several new octahedral binuclear ruthenium(III) complexes of the general composition [(EPh3)2(X)Ru-L-Ru(X)(EPh3)2] containing benzene dithiosemicarbazone ligands (where E = P or As; X = Cl or Br; L = binucleating ligands) is presented. All the complexes have been fully characterized by elemental analysis, FT-IR, UV-vis and EPR spectroscopy together with magnetic susceptibility measurements. IR study shows that the dithiosemicarbazone ligands behave as dianionic tridentate ligands coordinating through the oxygen atom of the deprotonated phenolic group, nitrogen atom of the azomethine group and thiolate sulphur. In DMF solution, all the complexes exhibit intense d-d transition and ligand-to-metal charge transfer (LMCT) transition in the visible region. The magnetic moment values of the complexes are in the range 1.78-1.82 BM, which reveals the presence of one unpaired electron on each metal ion. The EPR spectra of the liquid samples at LNT show the presence of three different 'g' values (gx ≠ gy ≠ gz) indicate a rhombic distortion around the ruthenium ion. All the complexes exhibit two quasi-reversible one electron oxidation responses (RuIII-RuIII/RuIII-RuIV; RuIII-RuIV/RuIV-RuIV) within the E1/2 range of 0.61-0.74 V and 0.93-0.98 V respectively, versus Ag/AgCl.

fac-Re(CO)3 complexes of 2,6-bis(4-substituted-1,2,3-triazol-1-ylmethyl)pyridine "click" ligands: synthesis, characterisation and photophysical properties.

PubMed

Anderson, Christopher B; Elliott, Anastasia B S; Lewis, James E M; McAdam, C John; Gordon, Keith C; Crowley, James D

2012-12-28

The syntheses of the 4-n-propyl and 4-phenyl substituted fac-Re(CO)(3) complexes of the tridentate "click" ligand (2,6-bis(4-substituted-1,2,3-triazol-1-ylmethyl)pyridine) are described. The complexes were obtained by refluxing methanol solutions of [Re(CO)(5)Cl], AgPF(6) and either the 4-propyl or 4-phenyl substituted ligand for 16 h. The ligands and the two rhenium(I) complexes were characterised by elemental analysis, HR-ESMS, ATR-IR, (1)H and (13)C NMR spectroscopy and the molecular structures of both complexes were confirmed by X-ray crystallography. The electronic structure of the fac-Re(CO)(3) "click" complexes was probed using UV-Vis, Raman and emission spectroscopy, cyclic voltammetry and DFT calculations. Altering the electronic nature of the ligand's substituent, from aromatic to alkyl, had little effect on the absorption/emission maxima and electrochemical properties of the complexes indicating that the 1,2,3-triazole unit may insulate the metal centre from the electronic modification at the ligands' periphery. Both Re(I) complexes were found to be weakly emitting with short excited state lifetimes. The electrochemistry of the complexes is defined by quasi-reversible Re oxidation and irreversible triazole-based ligand reduction processes.

New transition metal complexes of 2,4-dihydroxybenzaldehyde benzoylhydrazone Schiff base (H2dhbh): Synthesis, spectroscopic characterization, DNA binding/cleavage and antioxidant activity

NASA Astrophysics Data System (ADS)

Aboafia, Seyada A.; Elsayed, Shadia A.; El-Sayed, Ahmed K. A.; El-Hendawy, Ahmed M.

2018-04-01

New complexes [VO2(Hdhbh)] (1), [VO(phen)(dhbh)].1.5H2O (2), [Zn(Hdhbh)2] (3), [MoO2(dhbh)(D)] (D = H2O (4) or MeOH (5)), [Ru(PPh3)(dhbh)Cl(H2O)] (6), and [Pd(Hdhbh)Cl]·H2O (7) (H2dhbh = Schiff base derived from 2,4-dihydroxybenzaldehyde and benzoylhydrazone) have been isolated and characterized by IR, 1H NMR, Mass, UV-Visible and ESR spectroscopy. They were also investigated by cyclic voltammetry, thermal and magnetic measurements and the structure of complex cis-[MoO2(dhbh)(H2O)] (4) was solved by X-ray crystallography. Analytical data showed that H2dhbh behaves as monobasic/or dibasic tridentate ligand via phenolate O, azomethine N and amide O/or deprotonated amide O atoms. Antioxidant activity of the complexes has been evaluated against DPPH (2,2-diphenyl-1-picrylhydrazyl) radical and it has been found that oxovandium (IV) complex (2) displays the highest radical scavenging potency comparable to ascorbic acid as a standard antioxidant. The DNA binding properties of the ligand and its complexes have been investigated by electronic spectroscopy together with DNA cleavage by gel electrophoresis whose results showed also that vanadium (IV) complex (2) has a significant oxidative cleavage among other complexes.

Introduction of non-invasive prenatal testing as a first-tier aneuploidy screening test: A survey among Dutch midwives about their role as counsellors.

PubMed

Martin, Linda; Gitsels-van der Wal, Janneke T; de Boer, Marjon A; Vanstone, Meredith; Henneman, Lidewij

2018-01-01

In 2014, non-invasive prenatal testing (NIPT) for trisomies 21, 18 and 13 was added to the Dutch prenatal screening program as part of the TRIDENT study. Most (85%) pregnant Dutch women are counselled for prenatal aneuploidy screening by primary care midwives. This will remain when NIPT is implemented as a first-tier screening test. We therefore investigated midwife counsellors': 1) Knowledge about NIPT; 2) Attitudes towards NIPT as first-tier screening test; and 3) Experiences with informing clients about NIPT. Between April-June 2015, an online questionnaire to assess knowledge about NIPT, attitudes towards NIPT, and experiences with NIPT was completed by 436 Dutch primary care midwives. We found that 59% midwives answered ≥7 of 8 knowledge questions correctly. Continuing professional education attendance and more positive attitudes towards prenatal screening for Down syndrome were positively associated with the total knowledge score (β = 0.261; p = 0.007 and β = 0.204; p = 0.015, respectively). The majority (67%) were in favor of replacing First trimester Combined Test with NIPT, although 41% preferred to maintain a nuchal translucency measurement alongside NIPT. We conclude that midwives demonstrated solid knowledge about NIPT that may still be improved in some areas. Dutch midwives overwhelmingly support the integration of NIPT as a first-tier screening test. Copyright © 2017 Elsevier Ltd. All rights reserved.

Four transition metal complexes with a semicarbazone ligand bearing pyrazine unit

NASA Astrophysics Data System (ADS)

Chen, Hong; Ma, Xiu-qin; Lv, Yan-yun; Jia, Lei; Xu, Jun; Wang, Yuan; Ge, Zhi-jun

2016-04-01

Four new complexes based on L (where L = 3-ethyl-2-acetylpyrazine semicarbazone), namely [CoL2]Cl2·0.5H2O (1), [CoL2](NO3)2 (2), [CdL(H2O)2(NO3)](NO3)·H2O (3) and [CuL(CH3OH)Cl2]·[CuLCl2] (4) have been synthesized and characterized by X-ray diffraction analyses. The results show that the semicarbazone acts as a tridentate neutral ligand in all complexes. Each of complex 1 and 2 reveals a distorted octahedral geometry around the metal ion provided by two units of the ligand, while the ratio of the ligand and metal is 1:1 in complexes 3 and 4. The effect of complexes 1-4 on cell proliferation, apoptosis of human pancreatic cancer (Patu8988), human gastric cancer (SGC7901) and human hepatic cancer (SMMC7721) cell lines have been detected by MTT assay, Annexin V/PI double staining flow cytometry and TUNEL assay. The results show that complexes 1-4 can inhibit cell proliferation of Patu8988, SGC7901 and SMMC7721 cells, significantly higher than the effect of the ligand. However, the complex 4 reveals higher apoptosis rate, and displays up-regulated expression level of caspase 3, detected by western blotting, which also indicates the complex 4 can induce caspase-dependent cell apoptosis in SMMC7721.

Synthesis and spectral studies on metal complexes of s-triazine based ligand and non linear optical properties

NASA Astrophysics Data System (ADS)

Shanmugakala, R.; Tharmaraj, P.; Sheela, C. D.

2014-11-01

A series of transition metal complexes of type [ML] and [ML2]Cl2 (where M = Cu(II), Ni(II), Co(II) have synthesized from 2-phenylamino-4,6-dichloro-s-triazine and 3,5-dimethyl pyrazole; their characteristics have been investigated by means of elemental analyses, magnetic susceptibility, molar conductance, IR, UV-Vis, Mass, NMR and ESR spectra. The electrochemical behavior of copper(II) complexes we have studied, by using cyclic voltammetry. The ESR spectra of copper(II) complexes are recorded at 300 K and 77 K and their salient features are appropriately reported. Spectral datas, we found, show that the ligand acts as a neutral tridentate, and coordinates through the triazine ring nitrogen and pyrazolyl ring nitrogen atoms to the metal ion. Evident from our findings, the metal(II) complexes of [ML] type exhibit square pyramidal geometry, and that of [ML2]Cl2 exhibit octahedral geometry. The in vitro antimicrobial activities of the ligand and its complexes are evaluated against Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus vulgaris, Cryptococcus neoformans, Pseudomonas aeruginosa, Salmonella typhi, Serratia marcescens, Shigella flexneri, Vibrio cholera, Vibris parahaemolyticus, Aspergillus niger, Candida albicans and Penicillium oxalicum by well-diffusion method. The second harmonic generation efficiency of the ligand and its complexes are determined and compared with urea and KDP.

Deformation of Alaskan Volcanoes, Measured by Satellite Radar Inferometry

NASA Technical Reports Server (NTRS)

Freymueller, Jeff; Dean, Ken; Wyss, Max

1999-01-01

The purpose of this project was to determine the suitability of measuring active deformation of volcanoes in Alaska using Interferometric Synthetic Aperture Radar (INSAR) techniques. Work sponsored by this grant supported one graduate student (for almost 2 years) and one postdoc (for several months), and has resulted in two published peer-reviewed papers and a front-page article in EOS. An additional paper is in review and a fourth is in preparation. An additional paper in preparation was based in part on research supported by this grant and in part by a successor grant from NASA's Solid Earth Natural Hazards program. Over the course of this research, we documented measurable uplift of Trident volcano in the Katmai group, conducted a systematic study of the change in phase coherence over time on volcanic surfaces, and measured and modeled the spectacular 1.5 m deflation of Okmok caldera associated with its 1997 eruption. We also generated initial interferograms spanning the 1996 seismic swarm of Akutan volcano; however, during the period covered by this project we were not able to remove topography. That has been done under the subsequent funding and a paper is now in preparation. This report summarizes work done under two separate contracts because both were based on the same proposal to NASA's ADRO (Application Development and Research Opportunity) program. The first year was funded out of a grant from NASA Headquarters and the second and third years out of a grant through Goddard. The work, however, was a continuous three year effort.

Comparison of the time taken for localised breast surgery pre- and post-introduction of intra-operative digital specimen mammography.

PubMed

Carraro do Nascimento, Vinicius; Bourke, Anita G

2018-02-01

More than half of the patients with an impalpable malignant breast lesion have a mammographically detected and imaged-guided localisation, which can be technically challenging for the breast surgeon. Specimen imaging is used to confirm successful excision of the localised index lesion and has improved the operating list efficiency resulting in a higher number of excisions per surgical list. The aim of this study was to evaluate whether introducing IDSM (intra-operative digital specimen mammography) saved operation time for localised breast surgery. A single-centre retrospective review was undertaken to compare the operation time (from incision to wound closure) taken for excision of 114 consecutive image-guided localised impalpable breast lesions, performed using departmental specimen radiography (DSR), 6 months prior to the introduction of IDSM (Hologic, Trident ® ) in March 2013, with the theatre time taken for excision of 121 consecutive image-guided localised impalpable breast lesions in the 6 months following introduction of IDSM. There was no significant difference in mean surgical time, which were 47.8 (±27.3) minutes in the CSR group and 48.8 (±25.7) minutes in the IDSM group. We were expecting to confirm a reduction in theatre time with the introduction of IDSM. Surprisingly, no difference in operating times was demonstrated. Factors that influenced the impact of IDSM included the proximity of the imaging department to the operating theatre. © 2017 The Royal Australian and New Zealand College of Radiologists.

Synthesis, characterization of 1,2,4-triazole Schiff base derived 3d-metal complexes: Induces cytotoxicity in HepG2, MCF-7 cell line, BSA binding fluorescence and DFT study

NASA Astrophysics Data System (ADS)

Tyagi, Prateek; Tyagi, Monika; Agrawal, Swati; Chandra, Sulekh; Ojha, Himanshu; Pathak, Mallika

2017-01-01

Two novel Schiff base ligands H2L1 and H2L2 have been synthesized by condensation reaction of amine derivative of 1,2,4-triazole moiety with 2-hydroxy-4-methoxybenzaldehyde. Co(II), Ni(II), Cu(II) and Zn(II) of the synthesized Schiff bases were prepared by using a molar ratio of ligand:metal as 1:1. The structure of the Schiff bases and synthesized metal complexes were established by 1H NMR, UV-Vis, IR, Mass spectrometry and molar conductivity. The thermal stability of the complexes was study by TGA. Fluorescence quenching mechanism of metal complexes 1-4 show that Zn(II) and Cu(II) complex binds more strongly to BSA. In DFT studies the geometries of Schiff bases and metal complexes were fully optimized with respect to the energy using the 6-31 + g(d,p) basis set. The spectral data shows that the ligands behaves as binegative tridentate. On the basis of the spectral studies, TGA and DFT data an octahedral geometry has been assigned for Co(II), Ni(II), square planar for Cu(II) and tetrahedral for Zn(II) complexes. The anticancer activity were screened against human breast cancer cell line (MCF-7) and human hepatocellular liver carcinoma cell line (Hep-G2). Result indicates that metal complexes shows increase cytotoxicity in proliferation to cell lines as compared to free ligand.

Structural direction of hybrid organic-inorganic materials: Synthesis of vanadium oxyfluoride, copper vanadate, and copper molybdate solid state materials through solvuthermal and solution methods

NASA Astrophysics Data System (ADS)

Deburgomaster, Paul

The vast structural complexity of inorganic oxides with structure directing organocations, nitrogen containing ligands and organophosphonate ligands was explored. The hydrothermal reaction conditions utilized herein include the variables of temperature, pH, fill volume and stoichiometry. The systems studied included: (1) the complex materials rendered from reactions of organoamine cations on the structure of vanadium oxides, oxyfluorides and fluorides. As with other systems, the influence of the mineralizer HF was not limited to pH as fluorine incorporation was not uncommon. In specific cases this coincided with reduction of vanadium sites. (2) The copper-organonitrogen ligand/vanadium oxide/aromatic phosphonate system has been studied. The rigid aromatic di- and tri-phosphonate tethers have provided a series of materials which are structurally distinct from the previously investigated aliphatic series. The inclusion of copper-coordinated nitrogen bi- and tri-dentate ligands also provided structural diversity. Product composition was highly influenced by the HF/V ratio. A similar study was conducted with the ligand 1,4-carboxy-phenylphosphonic acid. (3) The preparation of a series of bimetallic organic-inorganic hybrid materials of the M(II)/VxOy/organonitrogen ligand class was further evidence of the utility of thermodynamically driven hydrothermal synthesis. (4) While decomposition of the spherical Keplerate molybdenum clusters is encountered under hydrothermal conditions, this highly soluble form of molybdate was investigated for the development of hybrid organic-inorganic room temperature solution synthesis.

Halide/pseudohalide complexes of cadmium(II) with benzimidazole: Synthesis, crystal structures and fluorescence properties

NASA Astrophysics Data System (ADS)

Zhao, Hai-Yan; Yang, Fu-Li; Li, Na; Wang, Xiao-Jing

2017-11-01

Two new dinuclear Cd(II) complexes, [CdL1Cl2]2·H2O (1) and [CdL1(N3)2]2·CH3OH (2) and one dicyanamide bridged one-dimensional polynuclear network [CdL1(μ1,5-dca)dca]n (3) of the potentially tridentate NNN-donor Schiff base 2-((1H-benzimidazol-2-yl-ethylimino)-methyl)pyridine (L1) and another dinucler Cd(II) complex [CdL2Cl(dca)]2 (4) of a similar NNN-donor Schiff base ligand 2-((1H-benzimidazol-2-yl-propylimino)-methyl)pyridine (L2), have been synthesized and characterized by elemental analyses, IR and single crystal X-ray crystallography. The ligands L1 and L2 are [1 + 1] condensation products of pyridine-2-carbaldehyde with 2-aminoethyl-1H-benzimidazole and 2-aminopropyl-1H-benzimidazole, respectively. In the complexes 1 and 4 the two Cd(II) centers are held together by the bridged chloride ligands, while in 2 the two Cd(II) centers are bridged by μ1,1-azide ions. Complex 3 has a one-dimensional infinite chain structure in which Cd(II) ions are bridged by single dicyanamide groups in end-to-end fashion. All the metal centers have a distorted octahedral geometry and H-bonding or π⋯π interactions are operative to bind the complex units in the solid state. Furthermore, these complexes have been investigated by thermogravimetric analyses and fluorescence spectra.

Diadema ascensionis (Echinodermata: Echinoidea) is not restricted to Oceanic Islands: evidence from morphological data.

PubMed

Gondim, A I; Dias, T L P; Christoffersen, M L

2013-05-01

The genus Diadema presently consists of seven species, two of which are known from the Brazilian coast: D. antillarum and D. ascensionis. The first is usually known for shallow coastal areas, while the second was apparently restricted to oceanic islands. In February 2011, a dense population of D. ascensionis was observed on the coastal reefs of Praia do Francês (Alagoas State, northeastern Brazil). Five specimens were collected and transported to the laboratory where morphological studies of the test and pedicellariae were conducted. Subsequently, visits were made to scientific collections in order to compare and confirm species identifications. Our observations confirm the presence of tridentate pedicellariae with narrow and strongly curved valves. The axial cavity in the tips of the spines is filled with dense nonreticular tissue. This taxonomic data confirms the occurrence of D. ascensionis in coastal areas. On the coastal reefs of Praia do Francês, animals were observed from the beach to the reef formations about 200 m offshore in areas with a sandy substrate and in reef cavities, usually in clear and well illuminated waters. Solitary individuals or groups of up to 15 individuals formed dense populations in the area. We stress the importance of pedicellariae for the specific identification of the Diadematidae, considering that they are quite constant and reliable at this taxonomic level. Our results demonstrate that D. ascensionis is not restricted to insular environments and that this species may be common in shallow coastal habitats.

Synthesis, physicochemical studies, embryos toxicity and DNA interaction of some new Iron(II) Schiff base amino acid complexes

NASA Astrophysics Data System (ADS)

Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.

2013-05-01

New Fe(II) Schiff base amino acid complexes derived from the condensation of o-hydroxynaphthaldehyde with L-alanine, L-phenylalanine, L-aspartic acid, L-histidine and L-arginine were synthesized and characterized by elemental analysis, IR, electronic spectra, and conductance measurements. The stoichiometry and the stability constants of the complexes were determined spectrophotometrically. The investigated Schiff bases exhibited tridentate coordination mode with the general formulae [Fe(HL)2]·nH2O for all amino acids except L-histidine. But in case of L-histidine, the ligand acts as tetradentate ([FeL(H2O)2]·2H2O), where HL = mono anion and L = dianion of the ligand. The structure of the prepared complexes is suggested to be octahedral. The prepared complexes were tested for their toxicity on chick embryos and found to be safe until a concentration of 100 μg/egg with full embryos formation. The interaction between CT-DNA and the investigated complexes were followed by spectrophotometry and viscosity measurements. It was found that, the prepared complexes bind to DNA via classical intercalative mode and showed a different DNA cleavage activity with the sequence: nhi > nari > nali > nasi > nphali. The thermodynamic Profile of the binding of nphali complex and CT-DNA was constructed by analyzing the experimental data of absorption titration and UV melting studies with the McGhee equation, van't Hoff's equation, and the Gibbs-Helmholtz equation.

Station corrections for the Katmai Region Seismic Network

USGS Publications Warehouse

Searcy, Cheryl K.

2003-01-01

Most procedures for routinely locating earthquake hypocenters within a local network are constrained to using laterally homogeneous velocity models to represent the Earth's crustal velocity structure. As a result, earthquake location errors may arise due to actual lateral variations in the Earth's velocity structure. Station corrections can be used to compensate for heterogeneous velocity structure near individual stations (Douglas, 1967; Pujol, 1988). The HYPOELLIPSE program (Lahr, 1999) used by the Alaska Volcano Observatory (AVO) to locate earthquakes in Cook Inlet and the Aleutian Islands is a robust and efficient program that uses one-dimensional velocity models to determine hypocenters of local and regional earthquakes. This program does have the capability of utilizing station corrections within it's earthquake location proceedure. The velocity structures of Cook Inlet and Aleutian volcanoes very likely contain laterally varying heterogeneities. For this reason, the accuracy of earthquake locations in these areas will benefit from the determination and addition of station corrections. In this study, I determine corrections for each station in the Katmai region. The Katmai region is defined to lie between latitudes 57.5 degrees North and 59.00 degrees north and longitudes -154.00 and -156.00 (see Figure 1) and includes Mount Katmai, Novarupta, Mount Martin, Mount Mageik, Snowy Mountain, Mount Trident, and Mount Griggs volcanoes. Station corrections were determined using the computer program VELEST (Kissling, 1994). VELEST inverts arrival time data for one-dimensional velocity models and station corrections using a joint hypocenter determination technique. VELEST can also be used to locate single events.

Hydricity, electrochemistry, and excited-state chemistry of Ir complexes for CO 2 reduction

DOE PAGES

Manbeck, Gerald F.; Garg, Komal; Shimoda, Tomoe; ...

2016-12-01

Here, we prepared electron-rich derivatives of [Ir(tpy)(ppy)Cl] + with modification of the bidentate (ppy) or tridentate (tpy) ligands in attempt to increase the reactivity for CO 2 reduction and the ability to transfer hydrides (hydricity). Density functional theory (DFT) calculations reveal that complexes with dimethyl-substituted ppy have similar hydricities to the non-substituted parent complex, and photocatalytic CO 2 reduction studies show selective CO formation. Substitution of tpy for bis(benzimidazole)-phenyl or -pyridine (L3 and L4, respectively) induces changes in the physical properties much more pronounced than addition of methyl groups to ppy. Theoretical data predict [Ir(L3)(ppy)(H)] is the strongest hydride donormore » among complexes studied in this work, but [Ir(L3)(ppy)(NCCH 3)] + cannot be reduced photochemically because the excited state reduction potential is only 0.52 V due to the negative ground state potential of –1.91 V. The excited state [Ir(L4)(ppy)(NCCH 3)] 2+ is the strongest oxidant among complexes studied in this work and the singly reduced species is formed readily upon photolysis in the presence of tertiary amines. Both [Ir(L3)(ppy)(NCCH 3)] + and [Ir(L4)(ppy)(NCCH 3)] 2+ exhibit electrocatalytic current for CO 2 reduction. While a significantly greater overpotential is needed for the L3 complex, a small amount of formate (5-10 %) generation in addition to CO was observed as predicted by the DFT calculations.« less

Crystal structure of tetra-kis-(μ3-2-{[1,1-bis-(hy-droxy-meth-yl)-2-oxidoeth-yl]imino-meth-yl}phenolato)tetra-copper(II) ethanol monosolvate 2.5-hydrate.

PubMed

Wang, Weilun; Ran, Jingwen

2015-05-01

The title compound, [Cu4(C11H13NO4)4]·CH3CH2OH·2.5H2O, is an electronically neutral tetra-nuclear copper(II) complex with a cubane-like Cu4O4 core. The complete molecule has point group symmetry 2. The phenol hy-droxy group and one of the three alcohol hy-droxy groups of each 2-{[tris-(hy-droxy-meth-yl)meth-yl]imino-meth-yl}phenol ligand are depro-ton-ated, while the secondary amine and the other two hy-droxy groups remain unchanged. The Cu(II) atoms in the Cu4O4 core are connected by four μ3-O atoms from the deprotonated alcohol hy-droxy groups. Each of the penta-coordinated Cu(II) ions has an NO4 distorted square-pyramidal environment through coordination to the tridentate Schiff base ligands. The Cu-N/O bond lengths span the range 1.902 (4)-1.955 (4) Å, similar to values reported for related structures. There are O-H⋯O hydrogen-bond inter-actions between the complex molecules and the ethanol and water solvent molecules, leading to the formation of a three-dimensional network. The ethanol solvent molecule is disordered about a twofold rotation axis. One of the two independent water molecules is also located on this twofold rotation axis and shows half-occupancy.

Synthesis and spectral characterization of mono- and binuclear copper(II) complexes derived from 2-benzoylpyridine-N4-methyl-3-thiosemicarbazone: Crystal structure of a novel sulfur bridged copper(II) box-dimer

NASA Astrophysics Data System (ADS)

Jayakumar, K.; Sithambaresan, M.; Aiswarya, N.; Kurup, M. R. Prathapachandra

2015-03-01

Mononuclear and binuclear copper(II) complexes of 2-benzoylpyridine-N4-methyl thiosemicarbazone (HL) were prepared and characterized by a variety of spectroscopic techniques. Structural evidence for the novel sulfur bridged copper(II) iodo binuclear complex is obtained by single crystal X-ray diffraction analysis. The complex [Cu2L2I2], a non-centrosymmetric box dimer, crystallizes in monoclinic C2/c space group and it was found to have distorted square pyramidal geometry (Addison parameter, τ = 0.238) with the square basal plane occupied by the thiosemicarbazone moiety and iodine atom whereas the sulfur atom from the other coordinated thiosemicarbazone moiety occupies the apical position. This is the first crystallographically studied system having non-centrosymmetrical entities bridged via thiolate S atoms with Cu(II)sbnd I bond. The tridentate thiosemicarbazone coordinates in mono deprotonated thionic tautomeric form in all complexes except in sulfato complex, [Cu(HL)(SO4)]·H2O (1) where it binds to the metal centre in neutral form. The magnetic moment values and the EPR spectral studies reflect the binuclearity of some of the complexes. The spin Hamiltonian and bonding parameters are calculated based on EPR studies. In all the complexes g|| > g⊥ > 2.0023 and the g values in frozen DMF are consistent with the dx2-y2 ground state. The thermal stabilities of some of the complexes were also determined.

Reactivity of a dearomatised pincer CoIIBr complex with PNCNHC donors: alkylation and Si-H bond activation via metal-ligand cooperation.

PubMed

Simler, Thomas; Choua, Sylvie; Danopoulos, Andreas A; Braunstein, Pierre

2018-05-18

The double aminolysis reaction of [Co{N(SiMe3)2}2] by the salt 1-(6-((dicyclohexylphosphaneyl)methyl)pyridin-2-yl)-3-(2,6-diisopropylphenyl)-1H-imidazol-3-ium bromide, which contains one phosphane, one pyridine and one imidazolium groups, of formula [o-Cy2PCH2(C5H3N)(o-C3H3N2DiPP)]Br and abbreviated as (CyPNpyrCim)Br, was previously shown to afford the Co(ii) complex [Co(CyP*NaCNHC)Br] (1) containing a dearomatised picolyl moiety in the tridentate, anionic donor ligand CyP*NaCNHC (Na = anionic amido, P* = vinylic P donor). We now report that formation of 1 is preceded by an intermediate tentatively assignable to the 5-coordinate Co(ii) complex [Co(CyPNpyrCNHC){N(SiMe3)2}Br] (2). The reaction of 1 with LiCH2SiMe3 afforded the dark purple, paramagnetic [Co(CyP*NaCNHC)CH2SiMe3] (3) with a low spin d7 CoII; the electronic configurations of 1 and 3 were corroborated by EPR spectroscopy. Addition of excess (≥4 equiv.) H2SiPh2 to a solution of 1 gave the diamagnetic [Co(CyP(SiHPh2)NCNHC)Br] (4) following Si-H activation and silylation of the ligand backbone at the α-CHP. Reduction of CoII to CoI by silanes is uncommon.

Phenanthridine-Containing Pincer-like Amido Complexes of Nickel, Palladium, and Platinum.

PubMed

Mandapati, Pavan; Giesbrecht, Patrick K; Davis, Rebecca L; Herbert, David E

2017-03-20

Proligands based on bis(8-quinolinyl)amine (L1) were prepared containing one (L2) and two (L3) benzo-fused N-heterocyclic phenanthridinyl (3,4-benzoquinolinyl) units. Taken as a series, L1-L3 provides a ligand template for exploring systematic π-extension in the context of tridentate pincer-like amido complexes of group 10 metals (1-M, 2-M, and 3-M; M = Ni, Pd, Pt). Inclusion of phenanthridinyl units was enabled by development of a cross-coupling/condensation route to 6-unsubstituted, 4-substituted phenanthridines (4-Br, 4-NO 2 , 4-NH 2 ) suitable for elaboration into the target ligand frameworks. Complexes 1-M, 2-M, and 3-M are redox-active; electrochemistry and UV-vis absorption spectroscopy were used to investigate the impact of π-extension on the electronic properties of the metal complexes. Unlike what is typically observed for benzannulated ligand-metal complexes, extending the π-system in metal complexes 1-M to 2-M to 3-M led to only a moderate red shift in the relative highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap as estimated by electrochemistry and similarly subtle changes to the onset of the lowest-energy absorption observed by UV-vis spectroscopy. Time-dependent density functional theory calculations revealed that benzannulation significantly impacts the atomic contributions to the LUMO and LUMO+1 orbitals, altering the orbital contributions to the lowest-energy transition but leaving the energy of this transition essentially unchanged.

Verification of Modelica-Based Models with Analytical Solutions for Tritium Diffusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rader, Jordan D.; Greenwood, Michael Scott; Humrickhouse, Paul W.

Here, tritium transport in metal and molten salt fluids combined with diffusion through high-temperature structural materials is an important phenomenon in both magnetic confinement fusion (MCF) and molten salt reactor (MSR) applications. For MCF, tritium is desirable to capture for fusion fuel. For MSRs, uncaptured tritium potentially can be released to the environment. In either application, quantifying the time- and space-dependent tritium concentration in the working fluid(s) and structural components is necessary.Whereas capability exists specifically for calculating tritium transport in such systems (e.g., using TMAP for fusion reactors), it is desirable to unify the calculation of tritium transport with othermore » system variables such as dynamic fluid and structure temperature combined with control systems such as those that might be found in a system code. Some capability for radioactive trace substance transport exists in thermal-hydraulic systems codes (e.g., RELAP5-3D); however, this capability is not coupled to species diffusion through solids. Combined calculations of tritium transport and thermal-hydraulic solution have been demonstrated with TRIDENT but only for a specific type of MSR.Researchers at Oak Ridge National Laboratory have developed a set of Modelica-based dynamic system modeling tools called TRANsient Simulation Framework Of Reconfigurable Models (TRANSFORM) that were used previously to model advanced fission reactors and associated systems. In this system, the augmented TRANSFORM library includes dynamically coupled fluid and solid trace substance transport and diffusion. Results from simulations are compared against analytical solutions for verification.« less

Verification of Modelica-Based Models with Analytical Solutions for Tritium Diffusion

DOE PAGES

Rader, Jordan D.; Greenwood, Michael Scott; Humrickhouse, Paul W.

2018-03-20

Here, tritium transport in metal and molten salt fluids combined with diffusion through high-temperature structural materials is an important phenomenon in both magnetic confinement fusion (MCF) and molten salt reactor (MSR) applications. For MCF, tritium is desirable to capture for fusion fuel. For MSRs, uncaptured tritium potentially can be released to the environment. In either application, quantifying the time- and space-dependent tritium concentration in the working fluid(s) and structural components is necessary.Whereas capability exists specifically for calculating tritium transport in such systems (e.g., using TMAP for fusion reactors), it is desirable to unify the calculation of tritium transport with othermore » system variables such as dynamic fluid and structure temperature combined with control systems such as those that might be found in a system code. Some capability for radioactive trace substance transport exists in thermal-hydraulic systems codes (e.g., RELAP5-3D); however, this capability is not coupled to species diffusion through solids. Combined calculations of tritium transport and thermal-hydraulic solution have been demonstrated with TRIDENT but only for a specific type of MSR.Researchers at Oak Ridge National Laboratory have developed a set of Modelica-based dynamic system modeling tools called TRANsient Simulation Framework Of Reconfigurable Models (TRANSFORM) that were used previously to model advanced fission reactors and associated systems. In this system, the augmented TRANSFORM library includes dynamically coupled fluid and solid trace substance transport and diffusion. Results from simulations are compared against analytical solutions for verification.« less

Crystal structure of aqua-1κO-{μ-2-[(2-hydroxy-ethyl)methylamino]ethanolato-2:1κ(4) O (1),N,O (2):O (1)}[μ-2,2'-(methylimino)diethanolato-1:2κ(4) O,N,O':O]dithiocyanato-1κN,2κN-chromium(III)copper(II).

PubMed

Rusanova, Julia A; Semenaka, Valentina V; Dyakonenko, Viktoriya V; Shishkin, Oleg V

2015-09-01

The title compound, [CrCu(C5H11NO2)(C5H12NO2)(NCS)2(H2O)] or [Cr(μ-mdea)Cu(μ-Hmdea)(NCS)2H2O], (where mdeaH2 is N-methylethanolamine, C5H13NO2) is formed as a neutral heterometal Cu(II)/Cr(III) complex. The mol-ecular structure of the complex is based on a binuclear {CuCr(μ-O)2} core. The coordination environment of each metal atom involves the N,O,O atoms of the tridentate ligand, one bridging O atom of the ligand and the N atom of the thio-cyanato ligands. The Cu(II) ion adopts a distorted square-pyramidal coordination while the Cr(III) ion has a distorted octa-hedral coordination geometry completed by the aqua ligand. In the crystal, the binuclear complexes are linked via two pairs of O-H⋯O hydrogen bonds to form inversion dimers, which are arranged in columns parallel to the a axis. In the μ-mdea ligand two -CH2 groups and the methyl group were refined as disordered over two sets of sites with equal occupancies. The structure was refined as a two-component twin with a twin scale factor of 0.242 (1).

Irmpd Action Spectroscopy and Computational Approaches to Elucidate Gas-Phase Structures and Energetics of 2'-DEOXYCYTIDINE and Cytidine Sodium Complexes

NASA Astrophysics Data System (ADS)

Zhu, Yanlong; Hamlow, Lucas; He, Chenchen; Gao, Juehan; Oomens, Jos; Rodgers, M. T.

2016-06-01

The local structures of DNA and RNA are influenced by protonation, deprotonation and noncovalent interactions with cations. In order to determine the effects of Na+ cationization on the gas-phase structures of 2'-deoxycytidine, [dCyd+Na]+, and cytidine, [Cyd+Na]+, infrared multiple photon dissociation (IRMPD) action spectra of these sodium cationized nucleosides are measured over the range extending from 500 to 1850 wn using the FELIX free electron laser. Complementary electronic structure calculations are performed to determine the stable low-energy conformations of these complexes. Geometry optimizations, frequency analyses, and IR spectra of these species are determined at the B3LYP/6-311+G(d,p) level of theory. Single-point energies are calculated at the B3LYP/6-311+G(2d,2p) level of theory to determine the relative stabilities of these conformations. Comparison of the measure IRMPD action spectra and computed linear IR spectra enable the conformations accessed in the experiments to be elucidated. For both cytosine nucleosides, tridentate binding of the Na+ cation to the O2, O4' and O5' atoms of the nucleobase and sugar is observed. Present results for the sodium cationized nucleosides are compared to results for the analogous protonated forms of these nucleosides to elucidate the effects of multiple chelating interactions with the sodium cation vs. hydrogen bonding interactions in the protonated systems on the structures and stabilities of these nucleosides.

Association between Chewing Side Preference and Dental Caries among Deciduous, Mixed and Permanent Dentition

PubMed Central

Sharma, Reena; Kashyap, Nilotpol; Prajapati, Deepesh; Kappadi, Damodar; Wadhwa, Saakshe; Gandotra, Shina; Yadav, Poonam

2016-01-01

Introduction Chewing Side Preference (CSP) is said to occur when mastication is recognized exclusively/consistently or predominantly on the same side of the jaw. It can be assessed by using the direct method - visual observation and indirect methods by electric programs, such as cinematography, kinetography and computerized electromyography. Aim The present study was aimed at evaluating the prevalence of CSP in deciduous, mixed and permanent dentitions and relating its association with dental caries. Materials and Methods In a cross-sectional observational study, 240 school going children aged 3 to 18years were randomly allocated to three experimental groups according to the deciduous dentition, mixed dentition and permanent dentition period. The existence of a CSP was determined using a direct method by asking the children to chew on a piece of gum (trident sugarless). The Mann Whitney U-test was used to compare the CSP and also among the boys and girls. The Spearman’s Correlation Coefficient was used to correlate CSP and dental caries among the three study groups and also among the groups. Results CSP was observed in 69%, 83% and 76% of children with primary, mixed and permanent dentition respectively (p>0.05). There was no statistically significant association between the presence of CSP and dental caries among the three study groups. Conclusion There was a weak or no correlation between gender and distribution of CSP and between presence of CSP and dental caries. PMID:27790569

Photoinduced energy transfer in transition metal complex oligomers

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-06-01

The work done over the past three years has been directed toward the preparation, characterization and photophysical examination of mono- and bimetallic diimine complexes. The work is part of a broader project directed toward the development of stable, efficient, light harvesting arrays of transition metal complex chromophores. One focus has been the synthesis of rigid bis-bidentate and bis-tridentate bridging ligands. The authors have managed to make the ligand bphb in multigram quantities from inexpensive starting materials. The synthetic approach used has allowed them to prepare a variety of other ligands which may have unique applications (vide infra). They have prepared,more » characterized and examined the photophysical behavior of Ru(II) and Re(I) complexes of the ligands. Energy donor/acceptor complexes of bphb have been prepared which exhibit nearly activationless energy transfer. Complexes of Ru(II) and Re(I) have also been prepared with other polyunsaturated ligands in which two different long lived (> 50 ns) excited states exist; results of luminescence and transient absorbance measurements suggest the two states are metal-to-ligand charge transfer and ligand localized {pi}{r_arrow}{pi}* triplets. Finally, the authors have developed methods to prepare polymetallic complexes which are covalently bound to various surfaces. The long term objective of this work is to make light harvesting arrays for the sensitization of large band gap semiconductors. Details of this work are provided in the body of the report.« less

Self-recognition of the racemic ligand in the formation of homochiral dinuclear V(V) complex: In vitro anticancer activity, DNA and HSA interaction.

PubMed

Kazemi, Zahra; Amiri Rudbari, Hadi; Mirkhani, Valiollah; Sahihi, Mehdi; Moghadam, Majid; Tangestaninejad, Shahram; Mohammadpoor-Baltork, Iraj; Kajani, Abolghasem Abbasi; Azimi, Gholamhassan

2017-07-28

The reaction of a racemic mixture of Schiff base tridentate ligand with vanadium(V) affords homochiral vanadium complex, (VO(R-L)) 2 O and (VO(S-L)) 2 O due to ligand "self-recognition" process. The formation of homochiral vanadium complex was confirmed by 1 H NMR, 13 C NMR and X-ray diffraction. The HSA- and DNA-binding of the resultant complex is assessed by absorption, fluorescence and circular dichroism (CD) spectroscopy methods. Based on the results, the HSA- and DNA-binding constant, K b , were found to be 8.0 × 10 4 and 1.9 × 10 5  M -1 , respectively. Interestingly, in vitro cytotoxicity assay revealed the potent anticancer activity of this complex on two prevalent cancer cell lines of MCF-7 (IC50 value of 14 μM) and HeLa (IC50 value of 36 μM), with considerably low toxicity on normal human fibroblast cells. The maximum cell mortality of 12.3% obtained after 48 h incubation of fibroblast cells with 100 μM of the complex. Additionally, the specific DNA- and HSA-binding was also shown using molecular docking method. The synthesized complex displayed high potential for biomedical applications especially for development of novel and efficient anticancer agents. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Measuring and modeling the variation in species-specific transpiration in temperate deciduous hardwoods.

PubMed

Bowden, Joseph D; Bauerle, William L

2008-11-01

We investigated which parameters required by the MAESTRA model were most important in predicting leaf-area-based transpiration in 5-year-old trees of five deciduous hardwood species-yoshino cherry (Prunus x yedoensis Matsum.), red maple (Acer rubrum L. 'Autumn Flame'), trident maple (Acer buergeranum Miq.), Japanese flowering cherry (Prunus serrulata Lindl. 'Kwanzan') and London plane-tree (Platanus x acerifolia (Ait.) Willd.). Transpiration estimated from sap flow measured by the heat balance method in branches and trunks was compared with estimates predicted by the three-dimensional transpiration, photosynthesis and absorbed radiation model, MAESTRA. MAESTRA predicted species-specific transpiration from the interactions of leaf-level physiology and spatially explicit micro-scale weather patterns in a mixed deciduous hardwood plantation on a 15-min time step. The monthly differences between modeled mean daily transpiration estimates and measured mean daily sap flow ranged from a 35% underestimation for Acer buergeranum in June to a 25% overestimation for A. rubrum in July. The sensitivity of the modeled transpiration estimates was examined across a 30% error range for seven physiological input parameters. The minimum value of stomatal conductance as incident solar radiation tends to zero was determined to be eight times more influential than all other physiological model input parameters. This work quantified the major factors that influence modeled species-specific transpiration and confirmed the ability to scale leaf-level physiological attributes to whole-crown transpiration on a species-specific basis.

Superoxo, μ-peroxo, and μ-oxo complexes from heme/O2 and heme-Cu/O2 reactivity: Copper ligand influences in cytochrome c oxidase models

PubMed Central

Kim, Eunsuk; Helton, Matthew E.; Wasser, Ian M.; Karlin, Kenneth D.; Lu, Shen; Huang, Hong-wei; Moënne-Loccoz, Pierre; Incarvito, Christopher D.; Rheingold, Arnold L.; Honecker, Marcus; Kaderli, Susan; Zuberbühler, Andreas D.

2003-01-01

The O2-reaction chemistry of 1:1 mixtures of (F8)FeII (1; F8 = tetrakis(2,6-diflurorophenyl)porphyrinate) and [(LMe2N)CuI]+ (2; LMe2N = N,N-bis{2-[2-(N′,N′-4-dimethylamino)pyridyl]ethyl}methylamine) is described, to model aspects of the chemistry occurring in cytochrome c oxidase. Spectroscopic investigations, along with stopped-flow kinetics, reveal that low-temperature oxygenation of 1/2 leads to rapid formation of a heme-superoxo species (F8)FeIII-(O\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{_{2}^{-}}}\\end{equation*}\\end{document}) (3), whether or not 2 is present. Complex 3 subsequently reacts with 2 to form [(F8)FeIII–(O\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{_{2}^{2-}}}\\end{equation*}\\end{document})–CuII(LMe2N)]+ (4), which thermally converts to [(F8)FeIII–(O)–CuII(LMe2N)]+ (5), which has an unusually bent (Fe–O–Cu) bond moiety. Tridentate chelation, compared with tetradentate, is shown to dramatically lower the ν(O–O) values observed in 4 and give rise to the novel structural features in 5. PMID:12655050

Determination of uranyl incorporation into biogenic manganese oxides using X-ray absorption spectroscopy and scattering

USGS Publications Warehouse

Webb, S.M.; Fuller, C.C.; Tebo, B.M.; Bargar, J.R.

2006-01-01

Biogenic manganese oxides are common and an important source of reactive mineral surfaces in the environment that may be potentially enhanced in bioremediation cases to improve natural attenuation. Experiments were performed in which the uranyl ion, UO22+ (U(VI)), at various concentrations was present during manganese oxide biogenesis. At all concentrations, there was strong uptake of U onto the oxides. Synchrotron-based extended X-ray absorption fine structure (EXAFS) spectroscopy and X-ray diffraction (XRD) studies were carried out to determine the molecular-scale mechanism by which uranyl is incorporated into the oxide and how this incorporation affects the resulting manganese oxide structure and mineralogy. The EXAFS experiments show that at low concentrations (2 mol % U, >4 ??M U(VI) in solution), the presence of U(VI) affects the stability and structure of the Mn oxide to form poorly ordered Mn oxide tunnel structures, similar to todorokite. EXAFS modeling shows that uranyl is present in these oxides predominantly in the tunnels of the Mn oxide structure in a tridentate complex. Observations by XRD corroborate these results. Structural incorporation may lead to more stable U(VI) sequestration that may be suitable for remediation uses. These observations, combined with the very high uptake capacity of the Mn oxides, imply that Mn-oxidizing bacteria may significantly influence dissolved U(VI) concentrations in impacted waters via sorption and incorporation into Mn oxide biominerals. ?? 2006 American Chemical Society.

Zinc complexes of the biomimetic N,N,O ligand family of substituted 3,3-bis(1-alkylimidazol-2-yl)propionates: the formation of oxalate from pyruvate

PubMed Central

Bruijnincx, Pieter C. A.; Lutz, Martin; den Breejen, Johan P.; van Koten, Gerard

2007-01-01

The coordination chemistry of the 2-His-1-carboxylate facial triad mimics 3,3-bis(1-methylimidazol-2-yl)propionate (MIm2Pr) and 3,3-bis(1-ethyl-4-isopropylimidazol-2-yl) propionate (iPrEtIm2Pr) towards ZnCl2 was studied both in solution and in the solid state. Different coordination modes were found depending both on the stoichiometry and on the ligand that was employed. In the 2:1 ligand-to-metal complex [Zn(MIm2Pr)2], the ligand coordinates in a tridentate, tripodal N,N,O fashion similar to the 2-His-1-carboxylate facial triad. However, the 1:1 ligand-to-metal complexes [Zn(MIm2Pr)Cl(H2O)] and [Zn(iPrEtIm2Pr)Cl] were crystallographically characterized and found to be polymeric in nature. A new, bridging coordination mode of the ligands was observed in both structures comprising N,N-bidentate coordination of the ligand to one zinc atom and O-monodentate coordination to a zinc second atom. A rather unique transformation of pyruvate into oxalate was found with [Zn(MIm2Pr)Cl], which resulted in the isolation of the new, oxalato bridged zinc coordination polymer [Zn2(MIm2Pr)2(ox)]·6H2O, the structure of which was established by X-ray crystal structure determination. PMID:17828423

Spectroscopic characterization of metal complexes of novel Schiff base. Synthesis, thermal and biological activity studies

NASA Astrophysics Data System (ADS)

Omar, M. M.; Mohamed, Gehad G.; Ibrahim, Amr A.

2009-07-01

Novel Schiff base (HL) ligand is prepared via condensation of 4-aminoantipyrine and 2-aminobenzoic acid. The ligand is characterized based on elemental analysis, mass, IR and 1H NMR spectra. Metal complexes are reported and characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance and thermal analyses (TGA, DrTGA and DTA). The molar conductance data reveal that all the metal chelates are non-electrolytes. IR spectra show that HL is coordinated to the metal ions in a uninegatively tridentate manner with NNO donor sites of the azomethine N, amino N and deprotonated caroxylic-O. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral. The thermal behaviour of these chelates shows that the hydrated complexes losses water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as, E*, ΔH*, ΔS* and ΔG* are calculated from the DrTG curves using Coats-Redfern method. The synthesized ligands, in comparison to their metal complexes also were screened for their antibacterial activity against bacterial species, Escherichia Coli, Pseudomonas aeruginosa, Staphylococcus Pyogones and Fungi (Candida). The activity data show that the metal complexes to be more potent/antibacterial than the parent Shciff base ligand against one or more bacterial species.

Rhenium complexes of bidentate, bis-bidentate and tridentate N-heterocyclic carbene ligands.

PubMed

Chan, Chung Ying; Barnard, Peter J

2015-11-28

A series of eight Rhenium(I)-N-heterocyclic carbene (NHC) complexes of the general form [ReCl(CO)3(C^C)] (where C^C is a bis(NHC) bidentate ligand), [ReCl(CO)3(C^C)]2 (where C^C is a bis-bidentate tetra-NHC ligand) and [Re(CO)3(C^N^C)](+)[X](-) (where C^N^C is a bis(NHC)-amine ligand and the counter ion X is either the ReO4(-) or PF6(-)) have been synthesised using a Ag2O transmetallation protocol. The novel precursor imidazolium salts and Re(I) complexes were characterized by elemental analysis, (1)H and (13)C NMR spectroscopy and the molecular structures for two imidazolium salt and six Re(I) complexes were determined by single crystal X-ray diffraction. These NHC ligand systems are of interest for possible applications in the development of Tc-99m or Re-186/188 radiopharmaceuticals and as such the stability of two complexes of the form [ReCl(CO)3(C^C)] and [Re(CO)3(C^N^C)][ReO4] were evaluated in ligand challenge experiments using the metal binding amino acids L-histidine or L-cysteine. These studies showed that the former was unstable, with the chloride ligand being replaced by either cysteine or histidine, while no evidence for transchelation was observed for the latter suggesting that bis(NHC)-amine ligands of this type may be suitable for biological applications.

Ligational behavior of Schiff bases towards transition metal ion and metalation effect on their antibacterial activity

NASA Astrophysics Data System (ADS)

Devi, Jai; Batra, Nisha; Malhotra, Rajesh

2012-11-01

New Schiff bases pyrazine-2-carboxylicacid (phenyl-pyridin-2-yl-methylene)-hydrazide (Hpch-bp) HL1 and pyrazine-2-carboxylicacid (pyridin-2-ylmethylene)-hydrazide (Hpch-pc) HL2 derived from condensation of pyrazine carboxylic hydrazide (Hpch) with 2-benzoyl pyridine (bp) or pyridine 2-carbaldehyde (pc) and their transition metal complexes of type ML(1-2)2 have been synthesized, where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). Characterization of ligands and their metal complexes was carried out by elemental analysis, conductimetric studies, magnetic susceptibility, spectroscopic techniques (IR, UV-VIS, NMR, ESR, Mass) and thermogravimetric analysis. The physico-chemical studies revealed octahedral geometry or distorted octahedral geometry around metal ion. These azomethine Schiff base ligands acted as tridentate ? coordinating through carbonyl, azomethine and pyridine nitrogen present in the ligand. The thermodynamic and thermal properties of the complexes have been investigated and it was observed on the basis of these studies that thermal stability of complexes follows the order Mn < Zn < Cu < Co < Ni. The ligands and their complexes were tested for in vitro antibacterial activity at different concentrations against bacteria viz. Gram positive Bacillus subtilis, Micrococcus luteus and Gram negative Pseudomonas aeruginosa, Pseudomonas mendocina. A marked enhancement in biocidal activity of the ligands under similar experimental conditions was observed as a consequence of coordination with metal ions. The trend of growth inhibition in the complexes was found to be in the order: Cu > Mn > Ni > Co > Zn.

Comparative studies on P-vanillin and O-vanillin of 2-hydrazinyl-2-oxo-N-phenylacetamide and their Mn(II) and Co(II) complexes

NASA Astrophysics Data System (ADS)

Yousef, T. A.; El-Reash, G. M. Abu; El-Tabai, M. N.

2018-05-01

Synthesis of complexes derived from hydrazones derived from both P-vanillin (H2L1) and its isomer O-vanillin (H2L2) of 2-hydrazinyl-2-oxo-N-phenylacetamide that coordinated with high magnetic metal ions of both Mn(II) and Co(II) were performed and characterized by different physicochemical methods, elemental analysis, (1H NMR, IR, and UV-visible spectra), also thermal analysis (TG and DTG) techniques and magnetic measurements. The molecular structures of the ligands and their Mn(II) and Co(II) complexes were optimized theoretically and the quantum chemical parameters were calculated. IR spectra suggest that the H2L1 behaved in a mononegative bidentate manner with both but H2L2 coordinated as mononegative tridentate with both Mn(II) and Co(II). The electronic spectra of the complexes as well as their magnetic moments suggested octahedral geometries for all the isolated complexes. The calculated values of binding energies indicated the stability of complexes is higher than that of ligand. The kinetic and thermodynamic parameters for the different decomposition steps in complexes were calculated using Coats-Redfern and Horowitz-Metzger equations. Moreover, the prepared ligands and their Mn(II) and Co(II) complexes were individually tested against a panel of gram positive Bacillus Subtilis and negative Escherichia coli microscopic organisms. Additionally cytotoxicity assay of two human tumor cell lines namely; hepatocellular carcinoma (liver) HePG-2, and mammary gland (breast) MCF-7 were tested.

In Vitro Screening for the Tumoricidal Properties of International Medicinal Herbs

PubMed Central

Mazzio, Elizabeth A.; Soliman, Karam F. A.

2009-01-01

There is growing use of anticancer complementary and alternative medicines (CAMs) worldwide. The purpose of the current study is to assess a sizeable variety of natural and plant sources of diverse origin, to ascertain prospective research directives for cancer treatment and potential new chemotherapy drug sources. In this study, 374 natural extracts (10 μg/mL-5 mg/mL) were evaluated for dose-dependent tumoricidal effects using immortal neuroblastoma of spontaneous malignant origin. The findings indicate no pattern of tumoricidal effects by diverse plants with similar families/genus under the classes Pinopsida, Equisetopsida, Lycopodiosida, Filicosida, Liliopsida Monocotyledons or Magnoliopsida Dicotyledons. The results indicate that many of the most commonly used CAMs exhibited relatively weak tumoricidal effects including cats claw, astragalus, ginseng, echinacea, mistletoe, milk thistle, slippery elm, cayenne, chamomile, don quai, meadowsweet, motherwort and shepherd's purse. The data demonstrate that the most potent plant extracts were randomly dispersed within the plantae kingdom (LC50 = 31-490 μg/mL) in order of the lowest LC50 Dioscorea villosa (Dioscoreaceae) > Sanguinaria canadensis (Papaveraceae) > Dipsacus asper (Dipsacaceae) > Populus balsamifera (Salicaceae) > Boswellia carteri (Burseraceae) > Cyamopsis psoralioides (Fabaceae) > Rhamnus cathartica (Rhamnaceae) > Larrea tridentate (Zygophyllaceae) > Dichroa febrifuga (Hydrangeaceae) > Batschia canescens (Boraginaceae) > Kochia scoparia (Chenopodiaceae) > Solanum xanthocarpum (Solanaceae) > Opoponax chironium (Umbelliferae) > Caulophyllum thalictroides (Berberidaceae) > Dryopteris crassirhizoma (Dryopteridaceae) > Garcinia cambogia (Clusiaceae) > Vitex agnus-castus (Verbenaceae) > Calamus draco (Arecaceae). These findings show tumoricidal effect by extracts of wild yam root, bloodroot, teasel root, bakuchi seed, dichroa root, kanta kari, garcinia fruit, mace, dragons blood and the biblically referenced herbs: balm of gilead bud, frankincense and myrrh gum. PMID:18844256

Cyberinfrastructure at IRIS: Challenges and Solutions Providing Integrated Data Access to EarthScope and Other Earth Science Data

NASA Astrophysics Data System (ADS)

Ahern, T. K.; Barga, R.; Casey, R.; Kamb, L.; Parastatidis, S.; Stromme, S.; Weertman, B. T.

2008-12-01

While mature methods of accessing seismic data from the IRIS DMC have existed for decades, the demands for improved interdisciplinary data integration call for new approaches. Talented software teams at the IRIS DMC, UNAVCO and the ICDP in Germany, have been developing web services for all EarthScope data including data from USArray, PBO and SAFOD. These web services are based upon SOAP and WSDL. The EarthScope Data Portal was the first external system to access data holdings from the IRIS DMC using Web Services. EarthScope will also draw more heavily upon products to aid in cross-disciplinary data reuse. A Product Management System called SPADE allows archive of and access to heterogeneous data products, presented as XML documents, at the IRIS DMC. Searchable metadata are extracted from the XML and enable powerful searches for products from EarthScope and other data sources. IRIS is teaming with the External Research Group at Microsoft Research to leverage a powerful Scientific Workflow Engine (Trident) and interact with the web services developed at centers such as IRIS to enable access to data services as well as computational services. We believe that this approach will allow web- based control of workflows and the invocation of computational services that transform data. This capability will greatly improve access to data across scientific disciplines. This presentation will review some of the traditional access tools as well as many of the newer approaches that use web services, scientific workflow to improve interdisciplinary data access.

Synthesis, electrochemical, structural, spectroscopic and biological activities of mixed ligand copper (II) complexes with 2-{[(Z)-(5-bromo-2-hydroxyphenyl)methylidene]amino}benzoic acid and nitrogenous bases

NASA Astrophysics Data System (ADS)

Choudhary, Mukesh; Patel, R. N.; Rawat, S. P.

2014-02-01

Three new copper (II) complexes viz. [Cu(L1)(bipy)]ṡ2H2O 1, [Cu(L1)(dmp)]ṡCH3CN 2, [Cu(L1)(phen)] 3 where L1H2 = 2-{[(Z)-(5-bromo-2-hydroxyphenyl)methylidene]amino}benzoic acid, bipy = 2,2‧-bipyridine; dmp = 2,9-dimethyl 1,10-phenanthroline, phen = 1,10-phenanthroline have been synthesized and characterized by physic-chemical and spectroscopic methods. The solid-state structures of 1 and 2 were determined by single crystal X-ray crystallography, which revealed distorted square pyramidal geometry. In solid-state structure, 1 is self-assembled via intermolecular π…π stacking and the distances between centroids of aromatic ring is 3.525 Å. L1H2 is a diprotic tridentate Schiff base ligand having ONO donor site. Infrared spectra, ligand field spectra and magnetic susceptibility measurements agree with the observed crystal structures. The EPR spectra of these complexes in frozen DMSO solutions showed a single at g ca. 2. The trend in g-value (g|| > g⊥ > 2.0023) suggests that the unpaired electron on copper (II) has d character. Copper (II) complexes 1-3 yielded an irreversible couple corresponding to the Cu (II)/Cu (I) redox process. Superoxide dismutase activity of all these complexes has been revealed to catalyze the dismutation of superoxide (O2-) and IC50 values were evaluated and discussed. Antimicrobial and antifungal activities of these complexes were also investigated.

Aeolian Sediment Trapping Efficiencies of Sparse Vegetation and its Ecohydrological Consequences in Drylands

NASA Astrophysics Data System (ADS)

Gonzales, H. B.; Ravi, S.; Li, J. J.; Sankey, J. B.

2016-12-01

Hydrological and aeolian processes control the redistribution of soil and nutrients in arid and semi arid environments thereby contributing to the formation of heterogeneous patchy landscapes with nutrient-rich resource islands surrounded by nutrient depleted bare soil patches. The differential trapping of soil particles by vegetation canopies may result in textural changes beneath the vegetation, which, in turn, can alter the hydrological processes such as infiltration and runoff. We conducted infiltration experiments and soil grain size analysis of several shrub (Larrea tridentate) and grass (Bouteloua eriopoda) microsites and in a heterogeneous landscape in the Chihuahuan desert (New Mexico, USA). Our results indicate heterogeneity in soil texture and infiltration patterns under grass and shrub microsites. We assessed the trapping effectiveness of vegetation canopies using a novel computational fluid dynamics (CFD) approach. An open-source software (OpenFOAM) was used to validate the data gathered from particle size distribution (PSD) analysis of soil within the shrub and grass microsites and their porosities (91% for shrub and 68% for grass) determined using terrestrial LiDAR surveys. Three-dimensional architectures of the shrub and grass were created using an open-source computer-aided design (CAD) software (Blender). The readily available solvers within the OpenFOAM architecture were modified to test the validity and optimize input parameters in assessing trapping efficiencies of sparse vegetation against aeolian sediment flux. The results from the numerical simulations explained the observed textual changes under grass and shrub canopies and highlighted the role of sediment trapping by canopies in structuring patch-scale hydrological processes.

Synthesis and spectral and redox properties of three triply bridged complexes of ruthenium

USGS Publications Warehouse

Llobet, A.; Curry, M.E.; Evans, H.T.; Meyer, T.J.

1989-01-01

Syntheses are described for the ligand-bridged complexes [(tpm)RuIII(??-O)(??-L)2RuIII(tpm) n+ (L = O2P(O)(OH), n = 0 (1); L = O2CO, n = 0 (2); L = O2CCH3, n = 2 (3); tpm is the tridentate, facial ligand tris(1-pyrazolyl)methane. The X-ray crystal structure of [(tpm)Ru(??-O)(??-O2P(O)(OH))2Ru(tpm)]??8H 2O was determined from three-dimensional X-ray counter data. The complex crystallizes in the trigonal space group P3221 with three molecules in a cell of dimensions a = 18.759 (4) A?? and c = 9.970 (6) A??. The structure was refined to a weighted R factor of 0.042 based on 1480 independent reflections with I ??? 3??(I). The structure reveals that the complex consists of two six-coordinate ruthenium atoms that are joined by a ??-oxo bridge (rRU-O = 1.87 A??; ???RuORu = 124.6??) and two ??-hydrogen phosphato bridges (average rRu-O = 2.07 A??) which are capped by two tpm ligands. The results of cyclic voltammetric and coulometric experiments show that the complexes undergo both oxidative and reductive processes in solution. Upon reduction, the ligand-bridged structure is lost and the monomer [(tpm)Ru(H2O)3]2+ appears quantitatively. All three complexes are diamagnetic in solution. The diamagnetism is a consequence of strong electronic coupling between the low-spin d5 Ru(III) metal ions through the oxo bridge and the relatively small Ru-O-Ru angle. ?? 1989 American Chemical Society.

Bivalent transition metal complexes of o-hydroxyacetophenone [N-(3-hydroxy-2-naphthoyl)] hydrazone: Spectroscopic, antibacterial, antifungal activity and thermogravimetric studies

NASA Astrophysics Data System (ADS)

Zaky, R. R.; Ibrahim, K. M.; Gabr, I. M.

2011-10-01

Schiff base complexes of Cu(II), Ni(II) and Zn(II) with the o-hydroxyacetophenone [N-(3-hydroxy-2-naphthoyl)] hydrazone (H 2o-HAHNH) containing N and O donor sites have been synthesized. Both ligand and its metal complexes were characterized by different physicochemical methods, elemental analysis, molar conductivity ( 1H NMR, 13C NMR, IR, UV-visible, ESR, MS spectra) and also thermal analysis (TG and DTG) techniques. The discussion of the outcome data of the prepared complexes indicates that the ligand behave as a bidentate and/or tridentate ligand. The electronic spectra of the complexes as well as their magnetic moments suggest octahedral geometries for all isolated complexes. The room temperature solid state ESR spectrum of the Cu(II) complex shows d x2- y2 as a ground state, suggesting tetragonally distorted octahedral geometry around Cu(II) centre. The molar conductance measurements proved that the complexes are non-electrolytes. The kinetic thermodynamic parameters such as: E#, Δ H#, Δ G#, Δ S# are calculated from the DTG curves, for the [Ni(H O-HAHNH) 2] and [Zn(H 2 O-HAHNH)(OAc) 2]·H 2O complexes using the Coats-Redfern equation. Also, the antimicrobial properties of all compounds were studied using a wide spectrum of bacterial and fungal strains. The [Cu(H o-HAHNH)(OAc)(H 2O) 2] complex was the most active against all strains, including Aspergillus sp., Stemphylium sp. and Trichoderma sp. Fungi; E. coli and Clostridium sp. Bacteria.

Tunable Rh 2(II,II) Light Absorbers as Excited State Electron Donors and Acceptors Accessible with Red/Near-IR Irradiation

DOE PAGES

Whittemore, Tyler; Millet, Agustin; Sayre, Hannah; ...

2018-04-04

In this study, a series of dirhodium(II,II) paddlewheeel complexes of the type cis-[Rh 2(μ-DTolF) 2(μ-L) 2][BF 4] 2, where DTolF = N,N'-di(p-tolyl)formamidinate and L = 1,8-naphthyridine (np), 2-(pyridin-2-yl)-1,8-naphthyridine (pynp), 2-(quinolin-2-yl)-1,8-naphthyridine (qnnp), and 2-(1,8-naphthyridin-2-yl)quinoxaline (qxnp), were synthesized and characterized. These molecules feature new tridentate ligands that concomitantly bridge the dirhodium core and cap the axial positions. The complexes absorb light strongly throughout the ultraviolet/visible range and into the near-infrared region and exhibit relatively long-lived triplet excited-state lifetimes. Both the singlet and triplet excited states exhibit metal/ligand-to-ligand charge transfer (ML-LCT) in nature as determined by transient absorption spectroscopy and spectroelectrochemistry measurements. Whenmore » irradiated with low-energy light, these black dyes are capable of undergoing reversible bimolecular electron transfer both to the electron acceptor methyl viologen and from the electron donor p-phenylenediamine. Photoinduced charge transfer in the latter was inaccessible with previous Rh 2(II,II) complexes. Finally, these results underscore the fact that the excited state of this class of molecules can be readily tuned for electron-transfer reactions upon simple synthetic modification and highlight their potential as excellent candidates for p- and n-type semiconductor applications and for improved harvesting of low-energy light to drive useful photochemical reactions.« less

Near Mbar-Level Dynamic Loading of Materials by Direct Laser-Irradiation

NASA Astrophysics Data System (ADS)

Tierney, T. E.; Swift, D. C.; Gammel, J. T.; Luo, S.; Johnson, R. P.

2003-12-01

We are developing techniques to perform direct-laser-illumination-driven, dynamic materials experiments at up to Mbar pressures with use of the Trident Laser Laboratory at Los Alamos. By temporally controlling the laser-irradiance, we are able to shape our loading for studies of fast-rise shocks, precursors, or isentropic compression. Laser-driven shock experiments are advantageous when considering the efficiency (fast turnaround), relative ease of sample recovery, taylorable dynamic loading, and in-situ structure diagnostics. Frequently, these experiments last 1-5 nanoseconds, and thus, permit investigation of rate-dependent processes and high strain rate environments. Laser-driven dynamic experiments are an important complement to traditional dynamic (e.g., light-gas gun) and static (e.g., diamond-anvil cell) experiments with certain advantages in studying equation of state, phase transitions and mechanical-chemical properties of Earth and planetary materials. Understanding high-pressure behavior in this regime is critical to phase boundaries for planetary interiors and dynamic properties of impact processes. Although we have studied silicates, oxides, metals, alloys and organic materials, this paper will focus on shocked and isentropically-compressed results obtained for iron in the range of 10-70 GPa (0.1-0.7 Mbar). Free surface velocities are measured using a Velocity Interferometer System for Any Reflector (VISAR). Nanosecond-scale laser experiments were interpreted with careful attention to exaggerated elastic-plastic effects and using accurate new equations of state for the phases of iron. This poster will present our technique, experimental results, and interpretation. *Work performed under the auspices of the US DOE under contract No. W-7405-ENG-36.

Imaging of Skeletal Disorders Caused by Fibroblast Growth Factor Receptor Gene Mutations.

PubMed

Sargar, Kiran M; Singh, Achint K; Kao, Simon C

2017-10-01

Fibroblast growth factors and fibroblast growth factor receptors (FGFRs) play important roles in human axial and craniofacial skeletal development. FGFR1, FGFR2, and FGFR3 are crucial for both chondrogenesis and osteogenesis. Mutations in the genes encoding FGFRs, types 1-3, are responsible for various skeletal dysplasias and craniosynostosis syndromes. Many of these disorders are relatively common in the pediatric population, and diagnosis is often challenging. These skeletal disorders can be classified based on which FGFR is affected. Skeletal disorders caused by type 1 mutations include Pfeiffer syndrome (PS) and osteoglophonic dysplasia, and disorders caused by type 2 mutations include Crouzon syndrome (CS), Apert syndrome (AS), and PS. Disorders caused by type 3 mutations include achondroplasia, hypochondroplasia, thanatophoric dysplasia (TD), severe achondroplasia with developmental delay and acanthosis nigricans, Crouzonodermoskeletal syndrome, and Muenke syndrome. Most of these mutations are inherited in an autosomal dominant fashion and are gain-of-function-type mutations. Imaging plays a key role in the evaluation of these skeletal disorders. Knowledge of the characteristic imaging and clinical findings can help confirm the correct diagnosis and guide the appropriate molecular genetic tests. Some characteristics and clinical findings include premature fusion of cranial sutures and deviated broad thumbs and toes in PS; premature fusion of cranial sutures and syndactyly of the hands and feet in AS; craniosynostosis, ocular proptosis, and absence of hand and foot abnormalities in CS; rhizomelic limb shortening, caudal narrowing of the lumbar interpediculate distance, small and square iliac wings, and trident hands in achondroplasia; and micromelia, bowing of the femora, and platyspondyly in TD. © RSNA, 2017.

Tunable Rh 2(II,II) Light Absorbers as Excited State Electron Donors and Acceptors Accessible with Red/Near-IR Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whittemore, Tyler; Millet, Agustin; Sayre, Hannah

In this study, a series of dirhodium(II,II) paddlewheeel complexes of the type cis-[Rh 2(μ-DTolF) 2(μ-L) 2][BF 4] 2, where DTolF = N,N'-di(p-tolyl)formamidinate and L = 1,8-naphthyridine (np), 2-(pyridin-2-yl)-1,8-naphthyridine (pynp), 2-(quinolin-2-yl)-1,8-naphthyridine (qnnp), and 2-(1,8-naphthyridin-2-yl)quinoxaline (qxnp), were synthesized and characterized. These molecules feature new tridentate ligands that concomitantly bridge the dirhodium core and cap the axial positions. The complexes absorb light strongly throughout the ultraviolet/visible range and into the near-infrared region and exhibit relatively long-lived triplet excited-state lifetimes. Both the singlet and triplet excited states exhibit metal/ligand-to-ligand charge transfer (ML-LCT) in nature as determined by transient absorption spectroscopy and spectroelectrochemistry measurements. Whenmore » irradiated with low-energy light, these black dyes are capable of undergoing reversible bimolecular electron transfer both to the electron acceptor methyl viologen and from the electron donor p-phenylenediamine. Photoinduced charge transfer in the latter was inaccessible with previous Rh 2(II,II) complexes. Finally, these results underscore the fact that the excited state of this class of molecules can be readily tuned for electron-transfer reactions upon simple synthetic modification and highlight their potential as excellent candidates for p- and n-type semiconductor applications and for improved harvesting of low-energy light to drive useful photochemical reactions.« less

Synthesis, crystal structure, antibacterial activity and theoretical studies on a novel mononuclear cobalt(II) complex based on 2,4,6-tris(2-pyridyl)-1,3,5-triazine ligand

NASA Astrophysics Data System (ADS)

Maghami, Mahboobeh; Farzaneh, Faezeh; Simpson, Jim; Ghiasi, Mina; Azarkish, Mohammad

2015-08-01

A cobalt complex was prepared from CoCl2·6H2O and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) in methanol and designated as [Co(tptz)(CH3OH)Cl2]·CH3OH·0.5H2O (1). It was characterized by several techniques including TGA analysis and FT-IR, UV-Vis and 1H NMR spectral studies. The crystal structure of 1 was determined by single-crystal X-ray diffraction. The Co(II) metal center in 1 is six coordinated with a distorted octahedral geometry. The tptz ligand is tridentate and coordinates to the cobalt through coplanar nitrogen atoms from the triazine and two pyridyl rings. Two chloride anions and a methanol molecule complete the inner coordination sphere of the metal ion. The optimized geometrical parameters obtained by DFT calculation are in good agreement with single XRD data. The in vitro antibacterial activity of various tptz complexes of Co(II), Ni(II), Cu(II), Mn(II) and Rh(III) were evaluated against Gram-positive (Bacillus subtilis, Staphylococcus aureus and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. Whereas all complexes exhibited good activity in comparison to standard antibacterial drugs, the inhibitory effects of complexes were found to be more than that of the parent ligand. Overall, the obtained results strongly suggest that the cobalt(II) complex is a suitable candidate for counteracting antibiotic resistant microorganisms.

Digestive Physiological Characteristics of the Gobiidae

PubMed Central

Hur, Sang-Woo; Kim, Shin-Kwon; Kim, Dae-Jung; Lee, Bae-Ik; Park, Su-Jin; Hwang, Hyung-Gyu; Jun, Je-Cheon; Myeong, Jeong-In; Lee, Chi-Hoon; Lee, Young-Don

2016-01-01

In this study, we investigated the characteristics of CCK-producing cells and mucus-secreting goblet cells with respect to stomach fish and stomachless fish of the Gobiidae in order to provide a basis for understanding the digestive physiology. Hairychin goby (Sagamia geneionema), which is stomachless fish, the numbers of mucus-secreting goblet cells is highest in the posterior intestine portion (P<0.05), while CCK-producing cells are scattered throughout the intestine. Gluttonous goby (Chasmichthys gulosus), which is stomach fish, mucus-secreting goblet cells are most abundant in the mid intestine portion (P<0.05), whereas CCK-producing cells are observed only in the anterior and mid intestine portion. Trident goby (Tridentiger obscurus) which is stomach fish, mucus-secreting goblet cells were most abundant in the mid intestine portion (P<0.05). CCK-producing cells are found in the anterior and mid intestine portion. Giurine goby, Rhinogobius giurinus which is also stomach fish, the largest number of mucus-secreting goblet cells showed in anterior intestine portion except for esophagus (P<0.05). CCK-producing cells are present only in the anterior and mid intestine portion. In S. geneionema, digestive action occurs in the posterior intestine portion to protect and functions to activate digestion. In contrast, in C. gulosus, T. obscurus and R. giurinus, their digestive action occurs in the anterior and mid intestine portion to protect and functions to activate digestion. Further studies of the modes of food ingestion by these fish, the contents of their digestive tracts, and the staining characteristics of the goblet cells need to be carried out. PMID:27796002

Syntheses, crystallographic, mass-spectroscopic determination and antioxidant studies of Co(II), Ni(II) and Cu(II) complexes of a new imidazol based Schiff base.

PubMed

Demir, Serkan; Güder, Aytaç; Yazıcılar, Turan K; Çağlar, Sema; Büyükgüngör, Orhan

2015-01-01

A new imidazole-based Schiff base, 2-((1H-imidazol-4-yl)methyleneamino)benzylalcohol (HL) and corresponding analogous bis(2-((1H-imidazol-4-yl)methyleneimino)benzylalcohol)metal(II) perchlorates (M: Co(1), Ni(2), Cu(3)) have prepared and characterized by elemental analyses, ESI-MS, IR, UV-Vis spectroscopies and conductivity measurements. X-ray single crystal structures of 1 and 2 have been also determined. Elemental analyses, spectroscopic and conductance data of 3 demonstrated similar structural features with these of crystallographically characterized complexes and based upon this relevances, HL ligands are neutrally coordinated to metal(II) ions in tridentate mode and all complexes are isostructural, dicathionic, contain perchlorate anions as complementary ions and, are in octahedral geometry with the formulae of [M(HL)2](ClO4)2 (for 3) and [M(HL)2](ClO4)2·H2O (for 1 and 2). Radical scavenging activities of the complexes have been evaluated by using DPPH, DMPD(+), and ABTS(+) assays. SC50 values (μg/mL) of the complexes and standards on DPPH, DMPD(+), ABTS(+) follow the sequences, BHA (9.06±0.33)>CMPD3 (15.62±0.52)>CMPD2 (17.43±0.29)>Rutin (21.65±0.60)>CMPD1 (25.67±0.51)>Trolox (28.57±0.37), Rutin>BHA>CMPD3>CMPD2>Trolox>CMPD1, and Trolox>BHA>CMPD3>CMPD2>Rutin>CMPD1 respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

Multiple seismogenic processes for high-frequency earthquakes at Katmai National Park, Alaska: Evidence from stress tensor inversions of fault-plane solutions

USGS Publications Warehouse

Moran, S.C.

2003-01-01

The volcanological significance of seismicity within Katmai National Park has been debated since the first seismograph was installed in 1963, in part because Katmai seismicity consists almost entirely of high-frequency earthquakes that can be caused by a wide range of processes. I investigate this issue by determining 140 well-constrained first-motion fault-plane solutions for shallow (depth < 9 km) earthquakes occuring between 1995 and 2001 and inverting these solutions for the stress tensor in different regions within the park. Earthquakes removed by several kilometers from the volcanic axis occur in a stress field characterized by horizontally oriented ??1 and ??3 axes, with ??1 rotated slightly (12??) relative to the NUVELIA subduction vector, indicating that these earthquakes are occurring in response to regional tectonic forces. On the other hand, stress tensors for earthquake clusters beneath several Katmai cluster volcanoes have vertically oriented ??1 axes, indicating that these events are occuring in response to local, not regional, processes. At Martin-Mageik, vertically oriented ??1 is most consistent with failure under edifice loading conditions in conjunction with localized pore pressure increases associated with hydrothermal circulation cells. At Trident-Novarupta, it is consistent with a number of possible models, including occurence along fractures formed during the 1912 eruption that now serve as horizontal conduits for migrating fluids and/or volatiles from nearby degassing and cooling magma bodies. At Mount Katmai, it is most consistent with continued seismicity along ring-fracture systems created in the 1912 eruption, perhaps enhanced by circulating hydrothermal fluids and/or seepage from the caldera-filling lake.

Crystal structure of aqua-1κO-{μ-2-[(2-hydroxy­ethyl)methylamino]ethanolato-2:1κ4 O 1,N,O 2:O 1}[μ-2,2′-(methylimino)diethanolato-1:2κ4 O,N,O′:O]dithiocyanato-1κN,2κN-chromium(III)copper(II)

PubMed Central

Rusanova, Julia A.; Semenaka, Valentina V.; Dyakonenko, Viktoriya V.; Shishkin, Oleg V.

2015-01-01

The title compound, [CrCu(C5H11NO2)(C5H12NO2)(NCS)2(H2O)] or [Cr(μ-mdea)Cu(μ-Hmdea)(NCS)2H2O], (where mdeaH2 is N-methylethanolamine, C5H13NO2) is formed as a neutral heterometal CuII/CrIII complex. The mol­ecular structure of the complex is based on a binuclear {CuCr(μ-O)2} core. The coordination environment of each metal atom involves the N,O,O atoms of the tridentate ligand, one bridging O atom of the ligand and the N atom of the thio­cyanato ligands. The CuII ion adopts a distorted square-pyramidal coordination while the CrIII ion has a distorted octa­hedral coordination geometry completed by the aqua ligand. In the crystal, the binuclear complexes are linked via two pairs of O—H⋯O hydrogen bonds to form inversion dimers, which are arranged in columns parallel to the a axis. In the μ-mdea ligand two –CH2 groups and the methyl group were refined as disordered over two sets of sites with equal occupancies. The structure was refined as a two-component twin with a twin scale factor of 0.242 (1). PMID:26396853

Polyaminoquinoline iron chelators for vectorization of antiproliferative agents: design, synthesis, and validation.

PubMed

Corcé, Vincent; Morin, Emmanuelle; Guihéneuf, Solène; Renault, Eric; Renaud, Stéphanie; Cannie, Isabelle; Tripier, Raphaël; Lima, Luís M P; Julienne, Karine; Gouin, Sébastien G; Loréal, Olivier; Deniaud, David; Gaboriau, François

2012-09-19

Iron chelation in tumoral cells has been reported as potentially useful during antitumoral treatment. Our aim was to develop new polyaminoquinoline iron chelators targeting tumoral cells. For this purpose, we designed, synthesized, and evaluated the biological activity of a new generation of iron chelators, which we named Quilamines, based on an 8-hydroxyquinoline (8-HQ) scaffold linked to linear polyamine vectors. These were designed to target tumor cells expressing an overactive polyamine transport system (PTS). A set of Quilamines bearing variable polyamine chains was designed and assessed for their ability to interact with iron. Quilamines were also screened for their cytostatic/cytotoxic effects and their selective uptake by the PTS in the CHO cell line. Our results show that both the 8-HQ moiety and the polyamine part participate in the iron coordination. HQ1-44, the most promising Quilamine identified, presents a homospermidine moiety and was shown to be highly taken up by the PTS and to display an efficient antiproliferative activity that occurred in the micromolar range. In addition, cytotoxicity was only observed at concentrations higher than 100 μM. We also demonstrated the high complexation capacity of HQ1-44 with iron while much weaker complexes were formed with other cations, indicative of a high selectivity. We applied the density functional theory to study the binding energy and the electronic structure of prototypical iron(III)-Quilamine complexes. On the basis of these calculations, Quilamine HQ1-44 is a strong tridentate ligand for iron(III) especially in the form of a 1:2 complex.

The forkhead box m1 transcription factor is essential for embryonic development of pulmonary vasculature.

PubMed

Kim, Il-Man; Ramakrishna, Sneha; Gusarova, Galina A; Yoder, Helena M; Costa, Robert H; Kalinichenko, Vladimir V

2005-06-10

Transgenic and gene knock-out studies demonstrated that the mouse Forkhead Box m1 (Foxm1 or Foxm1b) transcription factor (previously called HFH-11B, Trident, Win, or MPP2) is essential for hepatocyte entry into mitosis during liver development, regeneration, and liver cancer. Targeted deletion of Foxm1 gene in mice produces an embryonic lethal phenotype due to severe abnormalities in the development of liver and heart. In this study, we show for the first time that Foxm1(-/-) lungs exhibit severe hypertrophy of arteriolar smooth muscle cells and defects in the formation of peripheral pulmonary capillaries as evidenced by significant reduction in platelet endothelial cell adhesion molecule 1 staining of the distal lung. Consistent with these findings, significant reduction in proliferation of the embryonic Foxm1(-/-) lung mesenchyme was found, yet proliferation levels were normal in the Foxm1-deficient epithelial cells. Severe abnormalities of the lung vasculature in Foxm1(-/-) embryos were associated with diminished expression of the transforming growth factor beta receptor II, a disintegrin and metalloprotease domain 17 (ADAM-17), vascular endothelial growth factor receptors, Polo-like kinase 1, Aurora B kinase, laminin alpha4 (Lama4), and the Forkhead Box f1 transcription factor. Cotransfection studies demonstrated that Foxm1 stimulates transcription of the Lama4 promoter, and this stimulation requires the Foxm1 binding sites located between -1174 and -1145 bp of the mouse Lama4 promoter. In summary, development of mouse lungs depends on the Foxm1 transcription factor, which regulates expression of genes essential for mesenchyme proliferation, extracellular matrix remodeling, and vasculogenesis.

Synthesis and structures of bis-ligated zinc complexes supported by tridentate ketoimines that initiate L-lactide polymerization.

PubMed

Gerling, Kimberly A; Rezayee, Nomaan M; Rheingold, Arnold L; Green, David B; Fritsch, Joseph M

2014-11-21

Eight bis-ligated, homoleptic, zinc complexes were synthesized through the reaction of NNO Schiff base ketoimines bearing varying substituents with diethyl zinc in an inert atmosphere glovebox at room temperature and isolated in 62-95% yield. The complexes were characterized with (1)H, (13)C, and (19)F nuclear magnetic resonance spectroscopy, absorbance spectroscopy, high resolution mass spectrometry, elemental analysis, and single crystal X-ray crystallography. The complexes were shown to adopt distorted octahedral coordination geometry around zinc. The (1)H and (19)F NMR spectra of complexes 1-7 showed stable zinc coordination at 300 K while the effect of steric encumbrance and two trifluoromethyl groups in complex 8 was investigated with variable temperature NMR. The bis-ligated zinc complexes were effective initiators for the ring opening polymerization of L-lactide into poly-L-lactic acid (PLLA). With [L-lac]/[Zn complex] = 50, the bis-ligated zinc complexes yielded percentage conversion of 14-98% with polymerization times varying from 15-1440 min, where the longest reaction times were required when two trifluoromethyl groups were present. The addition of 4-fluorophenol co-catalyst resulted in up to a 5-fold increase in the percentage conversion in toluene solution and up to a 14-fold increase in bulk melt polymerization with reductions in the poly-dispersity index values for the isolated PLLA. Addition of 4-fluorophenol to complex 1 was studied with (1)H and (19)F NMR and appeared to yield an in situ generated zinc alkoxide complex.

A geochemical sampling technique for use in areas of active alpine glaciation: an application from the central Alaska Range

USGS Publications Warehouse

Stephens, G.C.; Evenson, E.B.; Detra, D.E.

1990-01-01

In mountainous regions containing extensive glacier systems there is a lack of suitable material for conventional geochemical sampling. As a result, in most geochemical sampling programs a few stream-sediment samples collected at, or near, the terminus of valley glaciers are used to evaluate the mineral potential of the glaciated area. We have developed and tested a technique which utilizes the medial moraines of valley glaciers for systematic geochemical exploration of the glacial catchment area. Moraine sampling provides geochemical information that is site-specific in that geochemical anomalies can be traced directly up-ice to bedrock sources. Traverses were made across the Trident and Susitna glaciers in the central Alaska Range where fine-grained (clay to sand size) samples were collected from each medial moraine. These samples were prepared and chemically analyzed to determine the concentration of specific elements. Fifty pebbles were collected at each moraine for archival purposes and for subsequent lithologic identification. Additionally, fifty cobbles and fifty boulders were examined and described at each sample site to determine the nature and abundance of lithologies present in the catchment area, the extent and nature of visible mineralization, the presence and intensity of hydrothermal alteration and the existence of veins, dikes and other minor structural features. Results from the central Alaska Range have delineated four distinct multi-element anomalies which are a response to potential mineralization up-ice from the medial moraine traverse. By integrating the lithologic, mineralogical and geochemical data the probable geological setting of the geochemical anomalies is determined. ?? 1990.

Synthesis, spectroscopic and DNA binding ability of CoII, NiII, CuII and ZnII complexes of Schiff base ligand (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol. X-ray crystal structure determination of cobalt (II) complex.

PubMed

Yarkandi, Naeema H; El-Ghamry, Hoda A; Gaber, Mohamed

2017-06-01

A novel Schiff base ligand, (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol (HL), has been designed and synthesized in addition to its metal chelates [Co(L) 2 ]·l2H 2 O, [Ni(L)Cl·(H 2 O) 2 ].5H 2 O, [Cu(L)Cl] and [Zn(L)(CH 3 COO)]. The structures of the isolated compounds have been confirmed and identified by means of different spectral and physicochemical techniques including CHN analysis, 1 H & 13 C NMR, mass spectral analysis, molar conductivity measurement, UV-Vis, infrared, magnetic moment in addition to TGA technique. The infrared spectral results ascertained that the ligand acts as monobasic tridentate binding to the metal centers via deprotonated hydroxyl oxygen, azomethine and imidazole nitrogen atoms. The UV-Vis, magnetic susceptibility and molar conductivity data implied octahedral geometry for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) complex and square planar for Cu(II) complex. X-ray structural analysis of Co(II) complex 1 has been reported and discussed. Moreover, the type of interaction between the ligand & its complexes towards salmon sperm DNA (SS-DNA) has been examined by the measurement of absorption spectra and viscosity which confirmed that the ligand and its complexes interact with DNA via intercalation interaction as concluded from the values of binding constants (K b ). Copyright © 2017 Elsevier B.V. All rights reserved.

In vitro screening for the tumoricidal properties of international medicinal herbs.

PubMed

Mazzio, Elizabeth A; Soliman, Karam F A

2009-03-01

There is growing use of anticancer complementary and alternative medicines (CAMs) worldwide. The purpose of the current study is to assess a sizeable variety of natural and plant sources of diverse origin, to ascertain prospective research directives for cancer treatment and potential new chemotherapy drug sources. In this study, 374 natural extracts (10 microg/mL-5 mg/mL) were evaluated for dose-dependent tumoricidal effects using immortal neuroblastoma of spontaneous malignant origin. The findings indicate no pattern of tumoricidal effects by diverse plants with similar families/genus under the classes Pinopsida, Equisetopsida, Lycopodiosida, Filicosida, Liliopsida Monocotyledons or Magnoliopsida Dicotyledons. The results indicate that many of the most commonly used CAMs exhibited relatively weak tumoricidal effects including cats claw, astragalus, ginseng, echinacea, mistletoe, milk thistle, slippery elm, cayenne, chamomile, don quai, meadowsweet, motherwort and shepherd's purse. The data demonstrate that the most potent plant extracts were randomly dispersed within the plantae kingdom (LC(50) = 31-490 microg/mL) in order of the lowest LC(50) Dioscorea villosa (Dioscoreaceae) > Sanguinaria canadensis (Papaveraceae) > Dipsacus asper (Dipsacaceae) > Populus balsamifera (Salicaceae) > Boswellia carteri (Burseraceae) > Cyamopsis psoralioides (Fabaceae) > Rhamnus cathartica (Rhamnaceae) > Larrea tridentate (Zygophyllaceae) > Dichroa febrifuga (Hydrangeaceae) > Batschia canescens (Boraginaceae) > Kochia scoparia (Chenopodiaceae) > Solanum xanthocarpum (Solanaceae) > Opoponax chironium (Umbelliferae) > Caulophyllum thalictroides (Berberidaceae) > Dryopteris crassirhizoma (Dryopteridaceae) > Garcinia cambogia (Clusiaceae) > Vitex agnus-castus (Verbenaceae) > Calamus draco (Arecaceae). These findings show tumoricidal effect by extracts of wild yam root, bloodroot, teasel root, bakuchi seed, dichroa root, kanta kari, garcinia fruit, mace, dragons blood and the biblically referenced herbs: balm of gilead bud, frankincense and myrrh gum. (c) 2008 John Wiley & Sons, Ltd.

Holding tight on feathers - structural specializations and attachment properties of the avian ectoparasite Crataerina pallida (Diptera, Hippoboscidae).

PubMed

Petersen, Dennis S; Kreuter, Nils; Heepe, Lars; Büsse, Sebastian; Wellbrock, Arndt H J; Witte, Klaudia; Gorb, Stanislav N

2018-04-30

The louse fly Crataerina pallida is an obligate blood-sucking ecto-parasite of the common swift Apus apus Due to reduction of the wings, C. pallida is unable to fly, thus an effective and reliable attachment to their host's plumage is of outmost importance. Its attachment system shows several modifications in comparison to other calyptrate flies. The most prominent ones are the large tridentate claws and the dichotomously shaped setae located on the pulvilli. Based on data from morphological analysis, confocal laser scanning microscopy, cryo-scanning electron microscopy and traction force experiments, performed on native (feathers) as well as artificial substrates (glass, epoxy-resin and silicone rubber), we showed that the entire attachment system is highly adapted to the fly's lifestyle as an ectoparasite. The claws in particular are the main contributor to strong attachment to the host. Resulting attachment forces on feathers make it impossible to detach C. pallida without damage of feathers or legs of the fly itself. Well-developed pulvilli are responsible for the attachment to smooth surfaces. Both dichotomously shaped setae and high setal density explain high safety factors observed on smooth substrates. For the first time, we demonstrated a material gradient within the setae with soft, resilin dominated apical tips and stiff, more sclerotized bases in Diptera. The empodium seems not to be directly involved in the attachment process, but it might operate as a cleaning device and may be essential to maintain the functionality of the entire attachment system. © 2018. Published by The Company of Biologists Ltd.

Postnatal Ablation of Foxm1 from Cardiomyocytes Causes Late Onset Cardiac Hypertrophy and Fibrosis without Exacerbating Pressure Overload-Induced Cardiac Remodeling

PubMed Central

Bolte, Craig; Zhang, Yufang; York, Allen; Kalin, Tanya V.; Schultz, Jo El J.; Molkentin, Jeffery D.; Kalinichenko, Vladimir V.

2012-01-01

Heart disease remains a leading cause of morbidity and mortality in the industrialized world. Hypertrophic cardiomyopathy is the most common genetic cardiovascular disorder and the most common cause of sudden cardiac death. Foxm1 transcription factor (also known as HFH-11B, Trident, Win or MPP2) plays an important role in the pathogenesis of various cancers and is a critical mediator of post-injury repair in multiple organs. Foxm1 has been previously shown to be essential for heart development and proliferation of embryonic cardiomyocytes. However, the role of Foxm1 in postnatal heart development and in cardiac injury has not been evaluated. To delete Foxm1 in postnatal cardiomyocytes, αMHC-Cre/Foxm1fl/fl mice were generated. Surprisingly, αMHC-Cre/Foxm1fl/fl mice exhibited normal cardiomyocyte proliferation at postnatal day seven and had no defects in cardiac structure or function but developed cardiac hypertrophy and fibrosis late in life. The development of cardiomyocyte hypertrophy and cardiac fibrosis in aged Foxm1-deficient mice was associated with reduced expression of Hey2, an important regulator of cardiac homeostasis, and increased expression of genes critical for cardiac remodeling, including MMP9, αSMA, fibronectin and vimentin. We also found that following aortic constriction Foxm1 mRNA and protein were induced in cardiomyocytes. However, Foxm1 deletion did not exacerbate cardiac hypertrophy or fibrosis following chronic pressure overload. Our results demonstrate that Foxm1 regulates genes critical for age-induced cardiomyocyte hypertrophy and cardiac fibrosis. PMID:23144938

Synthesis and spectral characterization of mono- and binuclear copper(II) complexes derived from 2-benzoylpyridine-N⁴-methyl-3-thiosemicarbazone: crystal structure of a novel sulfur bridged copper(II) box-dimer.

PubMed

Jayakumar, K; Sithambaresan, M; Aiswarya, N; Kurup, M R Prathapachandra

2015-03-15

Mononuclear and binuclear copper(II) complexes of 2-benzoylpyridine-N(4)-methyl thiosemicarbazone (HL) were prepared and characterized by a variety of spectroscopic techniques. Structural evidence for the novel sulfur bridged copper(II) iodo binuclear complex is obtained by single crystal X-ray diffraction analysis. The complex [Cu2L2I2], a non-centrosymmetric box dimer, crystallizes in monoclinic C2/c space group and it was found to have distorted square pyramidal geometry (Addison parameter, τ=0.238) with the square basal plane occupied by the thiosemicarbazone moiety and iodine atom whereas the sulfur atom from the other coordinated thiosemicarbazone moiety occupies the apical position. This is the first crystallographically studied system having non-centrosymmetrical entities bridged via thiolate S atoms with Cu(II)I bond. The tridentate thiosemicarbazone coordinates in mono deprotonated thionic tautomeric form in all complexes except in sulfato complex, [Cu(HL)(SO4)]·H2O (1) where it binds to the metal centre in neutral form. The magnetic moment values and the EPR spectral studies reflect the binuclearity of some of the complexes. The spin Hamiltonian and bonding parameters are calculated based on EPR studies. In all the complexes g||>g⊥>2.0023 and the g values in frozen DMF are consistent with the d(x2-y2) ground state. The thermal stabilities of some of the complexes were also determined. Copyright © 2014 Elsevier B.V. All rights reserved.

Adjustable coordination of a hybrid phosphine-phosphine oxide ligand in luminescent Cu, Ag and Au complexes.

PubMed

Dau, Thuy Minh; Asamoah, Benjamin Darko; Belyaev, Andrey; Chakkaradhari, Gomathy; Hirva, Pipsa; Jänis, Janne; Grachova, Elena V; Tunik, Sergey P; Koshevoy, Igor O

2016-09-28

A potentially tridentate hemilabile ligand, PPh2-C6H4-PPh(O)-C6H4-PPh2 (P(3)O), has been used for the construction of a family of bimetallic complexes [MM'(P(3)O)2](2+) (M = M' = Cu (1), Ag (2), Au (3); M = Au, M' = Cu (4)) and their mononuclear halide congeners M(P(3)O)Hal (M = Cu (5-7), Ag (8-10)). Compounds 1-10 have been characterized in the solid state by single-crystal X-ray diffraction analysis to reveal a variable coordination mode of the phosphine-oxide group of the P(3)O ligand depending on the preferable number of coordination vacancies on the metal center. According to the theoretical studies, the interaction of the hard donor P[double bond, length as m-dash]O moiety with d(10) ions becomes less effective in the order Cu > Ag > Au. 1-10 exhibit room temperature luminescence in the solid state, and the intensity and energy of emission are mostly determined by the nature of metal atoms. The photophysical characteristics of the monometallic species were compared with those of the related compounds M(P(3))Hal (11-16) with the non-oxidized ligand P(3). It was found that in the case of the copper complexes 5-7 the P(3)O hybrid ligand introduces effective non-radiative pathways of the excited state relaxation leading to poor emission, while for the silver luminophores the P[double bond, length as m-dash]O group leads mainly to the modulation of luminescence wavelength.

Synthesis, structural, optical band gap and biological studies on iron (III), nickel (II), zinc (II) and mercury (II) complexes of benzyl α-monoxime pyridyl thiosemicarbazone

NASA Astrophysics Data System (ADS)

Bedier, R. A.; Yousef, T. A.; Abu El-Reash, G. M.; El-Gammal, O. A.

2017-07-01

New ligand, (E)-2-((E)-2-(hydroxyimino)-1,2-diphenylethylidene)-N-(pyridin-2 yl) hydrazinecarbothioamide (H2DPPT) and its complexes [Fe(DPPT)Cl(H2O)], [Ni(H2DPPT)2Cl2], [Zn(HDPPT)(OAc)] and [Hg(HDPPT)Cl](H2O)4 were isolated and characterized by various of physico-chemical techniques. IR spectra show that H2DPPT coordinates to the metal ions as neutral NN bidentate, mononegative NNS tridentate and binegative NNSN tetradentate, respectively. From the modeling studies, the bond length, bond angle, HOMO, LUMO and dipole moment had been calculated to confirm the geometry of the ligands and their investigated complexes. The thermal studies showed the type of water molecules involved in metal complexes Furthermore, the kinetic and thermodynamic parameters for the different decomposition steps were calculated using the Coats-Redfern and Horowitz-Metzger methods. Also, the optical band gap (Eg) has been calculated to elucidate the conductivity of the isolated complexes. The optical transition energy (Eg) is direct and equals 3.34 and 3.44 ev for Ni and Fe complexes, respectively. The ligand and their metal complexes were screened for antibacterial activity against the following bacterial species, Bacillus thuringiensis, Staphylococcus aureus, Pseudomonas aeuroginosa and Escherichia coli. The results revealed that the metal complexes have more potent antibacterial compared with the ligand. Also, the degradation effect of the investigated compounds was tested showing that, Ni complex exhibited powerful and complete degradation effect on DNA.

The effects of microstructure on propagation of laser-driven radiative heat waves in under-dense high-Z plasma

NASA Astrophysics Data System (ADS)

Colvin, J. D.; Matsukuma, H.; Brown, K. C.; Davis, J. F.; Kemp, G. E.; Koga, K.; Tanaka, N.; Yogo, A.; Zhang, Z.; Nishimura, H.; Fournier, K. B.

2018-03-01

This work was motivated by previous findings that the measured laser-driven heat front propagation velocity in under-dense TiO2/SiO2 foams is slower than the simulated one [Pérez et al., Phys. Plasmas 21, 023102 (2014)]. In attempting to test the hypothesis that these differences result from effects of the foam microstructure, we designed and conducted an experiment on the GEKKO laser using an x-ray streak camera to compare the heat front propagation velocity in "equivalent" gas and foam targets, that is, targets that have the same initial density, atomic weight, and average ionization state. We first discuss the design and the results of this comparison experiment. To supplement the x-ray streak camera data, we designed and conducted an experiment on the Trident laser using a new high-resolution, time-integrated, spatially resolved crystal spectrometer to image the Ti K-shell spectrum along the laser-propagation axis in an under-dense TiO2/SiO2 foam cylinder. We discuss the details of the design of this experiment, and present the measured Ti K-shell spectra compared to the spectra simulated with a detailed superconfiguration non-LTE atomic model for Ti incorporated into a 2D radiation hydrodynamic code. We show that there is indeed a microstructure effect on heat front propagation in under-dense foams, and that the measured heat front velocities in the TiO2/SiO2 foams are consistent with the analytical model of Gus'kov et al. [Phys. Plasmas 18, 103114 (2011)].

Complexation of uranium(VI) with glutarimidoxioxime: thermodynamic and computational studies.

PubMed

Endrizzi, Francesco; Melchior, Andrea; Tolazzi, Marilena; Rao, Linfeng

2015-08-21

The complex formation between a cyclic ligand glutarimidoxioxime (denoted as HL(III) in this paper) and UO2(2+) is studied by potentiometry and microcalorimetry. Glutarimidoxioxime (HL(III)), together with glutarimidedioxime (H2L(I)) and glutardiamidoxime (H2L(II)), belongs to a family of amidoxime derivatives with prospective applications as binding agents for the recovery of uranium from seawater. An optimized procedure of synthesis that leads to the preparation of glutarimidoxioxime in the absence of other amidoxime byproducts is described in this paper. Speciation models based on the thermodynamic results from this study indicate that, compared with H2L(I) and H2L(II), HL(III) forms a much weaker complex with UO2(2+), UO2(L(III))(+), and cannot effectively compete with the hydrolysis equilibria of UO2(2+) under neutral or alkaline conditions. DFT computations, taking into account the solvation by including discrete hydration water molecules and bulk solvent effects, were performed to evaluate the structures and energies of the possible isomers of UO2(L(III))(+). Differing from the tridentate or η(2)-coordination modes previously found in the U(vi) complexes with amidoxime-related ligands, a bidentate mode, involving the oxygen of the oxime group and the nitrogen of the imino group, is found to be the most probable mode in UO2(L(III))(+). The bidentate coordination mode seems to be stabilized by the formation of a hydrogen bond between the carbonyl group of HL(III) and a water molecule in the hydration sphere of UO2(2+).

Tuning of Exchange Coupling and Switchable Magnetization Dynamics by Displacing the Bridging Ligands Observed in Two Dimeric Manganese(III) Compounds

NASA Astrophysics Data System (ADS)

Liu, Xiang-Yu; Cen, Pei-Pei; Wu, Li-Zhou; Li, Fei-Fei; Song, Wei-Ming; Xie, Gang; Chen, San-Ping

2017-03-01

Two Mn(III)-based dimers, [Mn2(bpad)2(CH3O)4]n (1) and [Mn2(bpad)2(pa)2]n·2H2O (2) (Hbpad = N3-benzoylpyridine-2-carboxamidrazone, H2pa = phthalic acid), have been assembled from a tridentate Schiff-base chelator and various anionic coligands. Noteworthily, compound 1 could be identified as a reaction precursor to transform to 2 in the presence of phthalic acid, resulting in a rarely structural conversion process in which the bridges between intradimer Mn(III) ions alter from methanol oxygen atom with μ2-O mode in 1 (Mn Mn distance of 3.046 Å) to syn-anti carboxylate in 2 (Mn Mn distance of 4.043 Å), while the Mn(III) centers retain hexa-coordinated geometries with independently distorted octahedrons in two compounds. The dc magnetic determinations reveal that ferromagnetic coupling between two metal centers with J = 1.31 cm-1 exists in 1, whereas 2 displays weak antiferromagnetic interactions with the coupling constant J of -0.56 cm-1. Frequency-dependent ac susceptibilities in the absence of dc field for 1 suggest slow relaxation of the magnetization with an energy barrier of 13.9 K, signifying that 1 features single-molecule magnet (SMM) behavior. This work presents a rational strategy to fine-tune the magnetic interactions and further magnetization dynamics of the Mn(III)-containing dinuclear units through small structural variations driven by the ingenious chemistry.

A two-dimensional silver(I) coordination polymer constructed from 4-aminophenylarsonate and triphenylphosphane: poly[[(μ₃-4-aminophenylarsonato-κ³N:O:O)(triphenylphosphane-κP)silver(I)] monohydrate].

PubMed

Xiao, Zu-Ping; Wen, Meng; Wang, Chun-Ya; Huang, Xi-He

2015-04-01

The title compound, {[Ag(C6H7AsNO3)(C18H15P)]·H2O}n, has been synthesized from the reaction of 4-aminophenylarsonic acid with silver nitrate, in aqueous ammonia, with the addition of triphenylphosphane (PPh3). The Ag(I) centre is four-coordinated by one amino N atom, one PPh3 P atom and two arsonate O atoms, forming a severely distorted [AgNPO2] tetrahedron. Two Ag(I)-centred tetrahedra are held together to produce a dinuclear [Ag2O2N2P2] unit by sharing an O-O edge. 4-Aminophenylarsonate (Hapa(-)) adopts a μ3-κ(3)N:O:O-tridentate coordination mode connecting two dinuclear units, resulting in a neutral [Ag(Hapa)(PPh3)]n layer lying parallel to the (101̄) plane. The PPh3 ligands are suspended on both sides of the [Ag(Hapa)(PPh3)]n layer, displaying up and down orientations. There is an R2(2)(8) hydrogen-bonded dimer involving two arsonate groups from two Hapa(-) ligands related by a centre of inversion. Additionally, there are hydrogen-bonding interactions involving the solvent water molecules and the arsonate and amine groups of the Hapa(-) ligands, and weak π-π stacking interactions within the [Ag(Hapa)(PPh3)]n layer. These two-dimensional layers are further assembled by weak van der Waals interactions to form the final architecture.

Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2002

USGS Publications Warehouse

Dixon, James P.; Stihler, Scott D.; Power, John A.; Tytgat, Guy; Moran, Seth C.; Sánchez, John; Estes, Steve; McNutt, Stephen R.; Paskievitch, John

2003-01-01

The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained seismic monitoring networks at historically active volcanoes in Alaska since 1988 (Power and others, 1993; Jolly and others, 1996; Jolly and others, 2001; Dixon and others, 2002). The primary objectives of this program are the seismic monitoring of active, potentially hazardous, Alaskan volcanoes and the investigation of seismic processes associated with active volcanism. This catalog presents the basic seismic data and changes in the seismic monitoring program for the period January 1, 2002 through December 31, 2002. Appendix G contains a list of publications pertaining to seismicity of Alaskan volcanoes based on these and previously recorded data. The AVO seismic network was used to monitor twenty-four volcanoes in real time in 2002. These include Mount Wrangell, Mount Spurr, Redoubt Volcano, Iliamna Volcano, Augustine Volcano, Katmai Volcanic Group (Snowy Mountain, Mount Griggs, Mount Katmai, Novarupta, Trident Volcano, Mount Mageik, Mount Martin), Aniakchak Crater, Mount Veniaminof, Pavlof Volcano, Mount Dutton, Isanotski Peaks, Shishaldin Volcano, Fisher Caldera, Westdahl Peak, Akutan Peak, Makushin Volcano, Great Sitkin Volcano, and Kanaga Volcano (Figure 1). Monitoring highlights in 2002 include an earthquake swarm at Great Sitkin Volcano in May-June; an earthquake swarm near Snowy Mountain in July-September; low frequency (1-3 Hz) tremor and long-period events at Mount Veniaminof in September-October and in December; and continuing volcanogenic seismic swarms at Shishaldin Volcano throughout the year. Instrumentation and data acquisition highlights in 2002 were the installation of a subnetwork on Okmok Volcano, the establishment of telemetry for the Mount Veniaminof subnetwork, and the change in the data acquisition system to an EARTHWORM detection system. AVO located 7430 earthquakes during 2002 in the vicinity of the monitored volcanoes. This catalog includes: (1) a description of instruments deployed in the field and their locations; (2) a description of earthquake detection, recording, analysis, and data archival systems; (3) a description of velocity models used for earthquake locations; (4) a summary of earthquakes located in 2002; and (5) an accompanying UNIX tar-file with a summary of earthquake origin times, hypocenters, magnitudes, and location quality statistics; daily station usage statistics; and all HYPOELLIPSE files used to determine the earthquake locations in 2002.The AVO seismic network was used to monitor twenty-four volcanoes in real time in 2002. These include Mount Wrangell, Mount Spurr, Redoubt Volcano, Iliamna Volcano, Augustine Volcano, Katmai Volcanic Group (Snowy Mountain, Mount Griggs, Mount Katmai, Novarupta, Trident Volcano, Mount Mageik, Mount Martin), Aniakchak Crater, Mount Veniaminof, Pavlof Volcano, Mount Dutton, Isanotski Peaks, Shishaldin Volcano, Fisher Caldera, Westdahl Peak, Akutan Peak, Makushin Volcano, Great Sitkin Volcano, and Kanaga Volcano (Figure 1). Monitoring highlights in 2002 include an earthquake swarm at Great Sitkin Volcano in May-June; an earthquake swarm near Snowy Mountain in July-September; low frequency (1-3 Hz) tremor and long-period events at Mount Veniaminof in September-October and in December; and continuing volcanogenic seismic swarms at Shishaldin Volcano throughout the year. Instrumentation and data acquisition highlights in 2002 were the installation of a subnetwork on Okmok Volcano, the establishment of telemetry for the Mount Veniaminof subnetwork, and the change in the data acquisition system to an EARTHWORM detection system. AVO located 7430 earthquakes during 2002 in the vicinity of the monitored volcanoes.This catalog includes: (1) a description of instruments deployed in the field and their locations; (2) a description of earthquake detection, recording, analysis, and data archival systems; (3) a description of velocity models used for earthquake locations; (4) a summary of earthquakes located in 2002; and (5) an accompanying UNIX tar-file with a summary of earthquake origin times, hypocenters, magnitudes, and location quality statistics; daily station usage statistics; and all HYPOELLIPSE files used to determine the earthquake locations in 2002.

Korean Waste Management Law and Waste Disposal Forms.

DTIC Science & Technology

1991-03-01

disinfection facility, dewatering facility, and other auxiliary facilities 2) An aerobic treatment facility composed of intake, detention basin, aerobic ... digestion or oxidation treatment facility, biological treatment facility, disinfection facility, dewatering facility, and other auxiliary facilities

Research and test facilities for development of technologies and experiments with commercial applications

NASA Technical Reports Server (NTRS)

1989-01-01

One of NASA'S agency-wide goals is the commercial development of space. To further this goal NASA is implementing a policy whereby U.S. firms are encouraged to utilize NASA facilities to develop and test concepts having commercial potential. Goddard, in keeping with this policy, will make the facilities and capabilities described in this document available to private entities at a reduced cost and on a noninterference basis with internal NASA programs. Some of these facilities include: (1) the Vibration Test Facility; (2) the Battery Test Facility; (3) the Large Area Pulsed Solar Simulator Facility; (4) the High Voltage Testing Facility; (5) the Magnetic Field Component Test Facility; (6) the Spacecraft Magnetic Test Facility; (7) the High Capacity Centrifuge Facility; (8) the Acoustic Test Facility; (9) the Electromagnetic Interference Test Facility; (10) the Space Simulation Test Facility; (11) the Static/Dynamic Balance Facility; (12) the High Speed Centrifuge Facility; (13) the Optical Thin Film Deposition Facility; (14) the Gold Plating Facility; (15) the Paint Formulation and Application Laboratory; (16) the Propulsion Research Laboratory; (17) the Wallops Range Facility; (18) the Optical Instrument Assembly and Test Facility; (19) the Massively Parallel Processor Facility; (20) the X-Ray Diffraction and Scanning Auger Microscopy/Spectroscopy Laboratory; (21) the Parts Analysis Laboratory; (22) the Radiation Test Facility; (23) the Ainsworth Vacuum Balance Facility; (24) the Metallography Laboratory; (25) the Scanning Electron Microscope Laboratory; (26) the Organic Analysis Laboratory; (27) the Outgassing Test Facility; and (28) the Fatigue, Fracture Mechanics and Mechanical Testing Laboratory.

Capsule review of the DOE research and development and field facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1980-09-01

A description is given of the roles of DOE's headquarters, field offices, major multiprogram laboratories, Energy Technology and Mining Technology Centers, and other government-owned, contractor-operated facilities, which are located in all regions of the US. Descriptions of DOE facilities are given for multiprogram laboratories (12); program-dedicated facilities (biomedical and environmental facilities-12, fossil energy facilities-7, fusion energy facility-1, nuclear development facilities-3, physical research facilities-4, safeguards facility-1, and solar facilities-2); and Production, Testing, and Fabrication Facilities (nuclear materials production facilities-5, weapon testing and fabrication complex-8). Three appendices list DOE field and project offices; DOE field facilities by state or territory, names, addresses,more » and telephone numbers; DOE R and D field facilities by type, contractor names, and names of directors. (MCW)« less

EPA Facility Registry Service (FRS): OIL

EPA Pesticide Factsheets

This dataset contains location and facility identification information from EPA's Facility Registry Service (FRS) for the subset of facilities that link to the Oil database. The Oil database contains information on Spill Prevention, Control, and Countermeasure (SPCC) and Facility Response Plan (FRP) subject facilities to prevent and respond to oil spills. FRP facilities are referred to as substantial harm facilities due to the quantities of oil stored and facility characteristics. FRS identifies and geospatially locates facilities, sites or places subject to environmental regulations or of environmental interest. Using vigorous verification and data management procedures, FRS integrates facility data from EPA's national program systems, other federal agencies, and State and tribal master facility records and provides EPA with a centrally managed, single source of comprehensive and authoritative information on facilities. This data set contains the subset of FRS integrated facilities that link to Oil facilities once the Oil data has been integrated into the FRS database. Additional information on FRS is available at the EPA website https://www.epa.gov/enviro/facility-registry-service-frs.

Survey of brachytherapy practice in the United States: a report of the Clinical Research Committee of the American Endocurietherapy Society.

PubMed

Nag, S; Owen, J B; Farnan, N; Pajak, T F; Martinez, A; Porter, A; Blasko, J; Harrison, L B

1995-01-01

To obtain reliable data on the extent of the brachytherapy practice in the United States by conducting a comprehensive survey of all facilities. The Clinical Research Committee of the AES surveyed all 1321 radiation oncology facilities identified in the Patterns of Care Study (PCS) of the American College of Radiology (ACR). Multiple mailings and follow-up were made to obtain a high response rate. Survey responders and nonresponders were compared using chi-square tests. Summary statistics were reported. Of the 1321 facilities, 1054 responded (80%). Hospital-based and larger facilities had a statistically significant higher rate of response. Brachytherapy was being performed at 819 facilities (the median number of procedures = 21-50). Two hundred and two facilities did no brachytherapy. The common isotopes used were 137Cs (705 facilities), 192Ir (585 facilities), 125I (236 facilities), and 131I (194 facilities). The common brachytherapy techniques used were intracavitary (751 facilities), interstitial (536 facilities), intraluminal (310 facilities), and plaques (148 facilities). Remote afterloaded brachytherapy was used at 205 centers as follows: high dose rate (HDR) (164), medium dose rate (MDR) (5), and low dose rate (LDR) (36). Computerized dosimetry was most commonly used (790 facilities), followed by Patterson-Parker (104 facilities) and Quimby (72 facilities). The common sites treated were cervix (701 facilities), endometrium (565 facilities), head and neck (354 facilities), and lung (344 facilities). Data regarding brachytherapy practice has been obtained from a large percentage (80%) of all facilities in the United States. The majority (78-81%) of radiation oncology facilities perform brachytherapy; however, its use is restricted to gynecological implants in many of these centers. The results from this survey will be used to develop a pattern of care study and data registry in brachytherapy.

Development and applications of nondestructive evaluation at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Whitaker, Ann F.

1990-01-01

A brief description of facility design and equipment, facility usage, and typical investigations are presented for the following: Surface Inspection Facility; Advanced Computer Tomography Inspection Station (ACTIS); NDE Data Evaluation Facility; Thermographic Test Development Facility; Radiographic Test Facility; Realtime Radiographic Test Facility; Eddy Current Research Facility; Acoustic Emission Monitoring System; Advanced Ultrasonic Test Station (AUTS); Ultrasonic Test Facility; and Computer Controlled Scanning (CONSCAN) System.