Polystyrene nanoparticle trafficking across MDCK-II

PubMed Central

Fazlollahi, Farnoosh; Angelow, Susanne; Yacobi, Nazanin R.; Marchelletta, Ronald; Yu, Alan S.L.; Hamm-Alvarez, Sarah F.; Borok, Zea; Kim, Kwang-Jin; Crandall, Edward D.

2011-01-01

Polystyrene nanoparticles (PNP) cross rat alveolar epithelial cell monolayers via non-endocytic transcellular pathways. To evaluate epithelial cell type-specificity of PNP trafficking, we studied PNP flux across Madin Darby canine kidney cell II monolayers (MDCK-II). Effects of calcium chelation (EGTA), energy depletion (sodium azide (NaN3) or decreased temperature), and endocytosis inhibitors methyl-β-cyclodextrin (MBC), monodansylcadaverine and dynasore were determined. Amidine-modified PNP cross MDCK-II 500 times faster than carboxylate-modified PNP. PNP flux did not increase in the presence of EGTA. PNP flux at 4°C and after treatment with NaN3 decreased 75% and 80%, respectively. MBC exposure did not decrease PNP flux, whereas dansylcadaverine- or dynasore-treated MDCK-II exhibited ~80% decreases in PNP flux. Confocal laser scanning microscopy revealed intracellular colocalization of PNP with clathrin heavy chain. These data indicate that PNP translocation across MDCK-II (1) occurs via clathrin-mediated endocytosis and (2) is dependent upon PNP physicochemical properties. We conclude that uptake/trafficking of nanoparticles into/across epithelia is dependent both on properties of the nanoparticles and the specific epithelial cell type. PMID:21310266

Phosphorylation of rat kidney Na-K pump at Ser938 is required for rapid angiotensin II-dependent stimulation of activity and trafficking in proximal tubule cells

PubMed Central

Massey, Katherine J.; Li, Quanwen; Rossi, Noreen F.; Keezer, Susan M.; Mattingly, Raymond R.

2015-01-01

How angiotensin (ANG) II acutely stimulates the Na-K pump in proximal tubules is only partially understood, limiting insight into how ANG II increases blood pressure. First, we tested whether ANG II increases the number of pumps in plasma membranes of native rat proximal tubules under conditions of rapid activation. We found that exposure to 100 pM ANG II for 2 min, which was previously shown to increase affinity of the Na-K pump for Na and stimulate activity threefold, increased the amount of the Na-K pump in plasma membranes of native tubules by 33%. Second, we tested whether previously observed increases in phosphorylation of the Na-K pump at Ser938 were part of the stimulatory mechanism. These experiments were carried out in opossum kidney cells, cultured proximal tubules stably coexpressing the ANG type 1 (AT1) receptor, and either wild-type or a S938A mutant of rat kidney Na-K pump under conditions found by others to stimulate activity. We found that 10 min of incubation in 10 pM ANG II stimulated activity of wild-type pumps from 2.3 to 3.5 nmol K·mg protein−1·min−1 and increased the amount of the pump in the plasma membrane by 80% but had no effect on cells expressing the S938A mutant. We conclude that acute stimulation of Na-K pump activity in native rat proximal tubules includes increased trafficking to the plasma membrane and that phosphorylation at Ser938 is part of the mechanism by which ANG II directly stimulates activity and trafficking of the rat kidney Na-K pump in opossum kidney cells. PMID:26582472

Angiotensin II modulates salty and sweet taste sensitivities.

PubMed

Shigemura, Noriatsu; Iwata, Shusuke; Yasumatsu, Keiko; Ohkuri, Tadahiro; Horio, Nao; Sanematsu, Keisuke; Yoshida, Ryusuke; Margolskee, Robert F; Ninomiya, Yuzo

2013-04-10

Understanding the mechanisms underlying gustatory detection of dietary sodium is important for the prevention and treatment of hypertension. Here, we show that Angiotensin II (AngII), a major mediator of body fluid and sodium homeostasis, modulates salty and sweet taste sensitivities, and that this modulation critically influences ingestive behaviors in mice. Gustatory nerve recording demonstrated that AngII suppressed amiloride-sensitive taste responses to NaCl. Surprisingly, AngII also enhanced nerve responses to sweeteners, but had no effect on responses to KCl, sour, bitter, or umami tastants. These effects of AngII on nerve responses were blocked by the angiotensin II type 1 receptor (AT1) antagonist CV11974. In behavioral tests, CV11974 treatment reduced the stimulated high licking rate to NaCl and sweeteners in water-restricted mice with elevated plasma AngII levels. In taste cells AT1 proteins were coexpressed with αENaC (epithelial sodium channel α-subunit, an amiloride-sensitive salt taste receptor) or T1r3 (a sweet taste receptor component). These results suggest that the taste organ is a peripheral target of AngII. The specific reduction of amiloride-sensitive salt taste sensitivity by AngII may contribute to increased sodium intake. Furthermore, AngII may contribute to increased energy intake by enhancing sweet responses. The linkage between salty and sweet preferences via AngII signaling may optimize sodium and calorie intakes.

Effect of Cu(II), Cd(II) and Zn(II) on Pb(II) biosorption by algae Gelidium-derived materials.

PubMed

Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

2008-06-15

Biosorption of Pb(II), Cu(II), Cd(II) and Zn(II) from binary metal solutions onto the algae Gelidium sesquipedale, an algal industrial waste and a waste-based composite material was investigated at pH 5.3, in a batch system. Binary Pb(II)/Cu(II), Pb(II)/Cd(II) and Pb(II)/Zn(II) solutions have been tested. For the same equilibrium concentrations of both metal ions (1 mmol l(-1)), approximately 66, 85 and 86% of the total uptake capacity of the biosorbents is taken by lead ions in the systems Pb(II)/Cu(II), Pb(II)/Cd(II) and Pb(II)/Zn(II), respectively. Two-metal results were fitted to a discrete and a continuous model, showing the inhibition of the primary metal biosorption by the co-cation. The model parameters suggest that Cd(II) and Zn(II) have the same decreasing effect on the Pb(II) uptake capacity. The uptake of Pb(II) was highly sensitive to the presence of Cu(II). From the discrete model it was possible to obtain the Langmuir affinity constant for Pb(II) biosorption. The presence of the co-cations decreases the apparent affinity of Pb(II). The experimental results were successfully fitted by the continuous model, at different pH values, for each biosorbent. The following sequence for the equilibrium affinity constants was found: Pb>Cu>Cd approximately Zn.

Cd(II) and Pb(II) complexes of the polyether ionophorous antibiotic salinomycin

PubMed Central

2011-01-01

Background The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II) ions in in vivo experiments, despite so far no Pb(II)-containing compounds of defined composition have been isolated and characterized. To assess the potential of polyether ionophores as possible antidotes in the agriculture, a detailed study on their in vitro complexation with toxic metal ions is required. In the present paper we report for the first time the preparation and the structure elucidation of salinomycin complexes with ions of cadmium(II) and lead(II). Results New metal(II) complexes of the polyether ionophorous antibiotic salinomycin with Cd(II) and Pb(II) ions were prepared and structurally characterized by IR, FAB-MS and NMR techniques. The spectroscopic information and elemental analysis data reveal that sodium salinomycin (SalNa) undergoes a reaction with heavy metal(II) ions to form [Cd(Sal)2(H2O)2] (1) and [Pb(Sal)(NO3)] (2), respectively. Abstraction of sodium ions from the cavity of the antibiotic is occurring during the complexation reaction. Salinomycin coordinates with cadmium(II) ions as a bidentate monoanionic ligand through the deprotonated carboxylic moiety and one of the hydroxyl groups to yield 1. Two salinomycin anions occupy the equatorial plane of the Cd(II) center, while two water molecules take the axial positions of the inner coordination sphere of the metal(II) cation. Complex 2 consists of monoanionic salinomycin acting in polydentate coordination mode in a molar ratio of 1: 1 to the metal ion with one nitrate ion for charge compensation. Conclusion The formation of the salinomycin heavy metal(II) complexes indicates a possible antidote activity of the ligand in case of chronic/acute intoxications likely to occur in the stock farming

Free metal ion depletion by "Good's" buffers. III. N-(2-acetamido)iminodiacetic acid, 2:1 complexes with zinc(II), cobalt(II), nickel(II), and copper(II); amide deprotonation by Zn(II), Co(II), and Cu(II).

PubMed

Lance, E A; Rhodes, C W; Nakon, R

1983-09-01

Potentiometric, visible, infrared, electron spin, and nuclear magnetic resonance studies of the complexation of N-(2-acetamido)iminodiacetic acid (H2ADA) by Ca(II), Mg(II), Mn(II), Zn(II), Co(II), Ni(II), and Cu(II) are reported. Ca(II) and Mg(II) were found not to form 2:1 ADA2- to M(II) complexes, while Mn(II), Cu(II), Ni(II), Zn(II), and Co(II) did form 2:1 metal chelates at or below physiological pH values. Co(II) and Zn(II), but not Cu(II), were found to induce stepwise deprotonation of the amide groups to form [M(H-1ADA)4-(2)]. Formation (affinity) constants for the various metal complexes are reported, and the probable structures of the various metal chelates in solution are discussed on the basis of various spectral data.

Biosorption of lead (II) ions by NaOH-activated apple (Malus domestica) juice residue

NASA Astrophysics Data System (ADS)

Arimurti, Devita Dwi; Heraldy, Eddy; Lestari, Witri Wahyu

2016-02-01

This research studied the removal of Pb(II) ions from aqueous solutions using NaOH-activated apple (Malus domestica) juice residue. Biosorbent was characterized with Fourier Transform Infrared Spectrophotometer (FTIR), and Surface Area Analyzer (SAA). The effects of biosorbent dosage, pH, contact time and initial metal ion concentration had been investigated in batch-adsorption method. The biosorption kinetic data were analyzed by pseudo-first-order and pseudo-second-order kinetics model. Freundlich and Langmuir's isotherm were used to describe the biosorption process. The optimum conditions of Pb(II) adsorption was observed at 60 min of contact time, pH 4, and 0.1 g biosorbent dosage in 25 ml solution. The biosorption kinetics followed the pseudo-second-order kinetic model, resulted biosorption constant rate of 0.184 g.mg-1.min-1. The Langmuir isotherm model exhibited the best fit to experimental data. The maximum biosorption capacity of Pb(II) determined according to the Langmuir model was 90.90 mg.g-1 at 302 K, with the adsorption energy of 26.429 kJ.mol-1.

Binding Selectivity of Methanobactin from Methylosinus trichosporium OB3b for Copper(I), Silver(I), Zinc(II), Nickel(II), Cobalt(II), Manganese(II), Lead(II), and Iron(II).

PubMed

McCabe, Jacob W; Vangala, Rajpal; Angel, Laurence A

2017-12-01

Methanobactin (Mb) from Methylosinus trichosporium OB3b is a member of a class of metal binding peptides identified in methanotrophic bacteria. Mb will selectively bind and reduce Cu(II) to Cu(I), and is thought to mediate the acquisition of the copper cofactor for the enzyme methane monooxygenase. These copper chelating properties of Mb make it potentially useful as a chelating agent for treatment of diseases where copper plays a role including Wilson's disease, cancers, and neurodegenerative diseases. Utilizing traveling wave ion mobility-mass spectrometry (TWIMS), the competition for the Mb copper binding site from Ag(I), Pb(II), Co(II), Fe(II), Mn(II), Ni(II), and Zn(II) has been determined by a series of metal ion titrations, pH titrations, and metal ion displacement titrations. The TWIMS analyses allowed for the explicit identification and quantification of all the individual Mb species present during the titrations and measured their collision cross-sections and collision-induced dissociation patterns. The results showed Ag(I) and Ni(II) could irreversibly bind to Mb and not be effectively displaced by Cu(I), whereas Ag(I) could also partially displace Cu(I) from the Mb complex. At pH ≈ 6.5, the Mb binding selectivity follows the order Ag(I)≈Cu(I)>Ni(II)≈Zn(II)>Co(II)>Mn(II)≈Pb(II)>Fe(II), and at pH 7.5 to 10.4 the order is Ag(I)>Cu(I)>Ni(II)>Co(II)>Zn(II)>Mn(II)≈Pb(II)>Fe(II). Breakdown curves of the disulfide reduced Cu(I) and Ag(I) complexes showed a correlation existed between their relative stability and their compact folded structure indicated by their CCS. Fluorescence spectroscopy, which allowed the determination of the binding constant, compared well with the TWIMS analyses, with the exception of the Ni(II) complex. Graphical abstract ᅟ.

Binding Selectivity of Methanobactin from Methylosinus trichosporium OB3b for Copper(I), Silver(I), Zinc(II), Nickel(II), Cobalt(II), Manganese(II), Lead(II), and Iron(II)

NASA Astrophysics Data System (ADS)

McCabe, Jacob W.; Vangala, Rajpal; Angel, Laurence A.

2017-12-01

Methanobactin (Mb) from Methylosinus trichosporium OB3b is a member of a class of metal binding peptides identified in methanotrophic bacteria. Mb will selectively bind and reduce Cu(II) to Cu(I), and is thought to mediate the acquisition of the copper cofactor for the enzyme methane monooxygenase. These copper chelating properties of Mb make it potentially useful as a chelating agent for treatment of diseases where copper plays a role including Wilson's disease, cancers, and neurodegenerative diseases. Utilizing traveling wave ion mobility-mass spectrometry (TWIMS), the competition for the Mb copper binding site from Ag(I), Pb(II), Co(II), Fe(II), Mn(II), Ni(II), and Zn(II) has been determined by a series of metal ion titrations, pH titrations, and metal ion displacement titrations. The TWIMS analyses allowed for the explicit identification and quantification of all the individual Mb species present during the titrations and measured their collision cross-sections and collision-induced dissociation patterns. The results showed Ag(I) and Ni(II) could irreversibly bind to Mb and not be effectively displaced by Cu(I), whereas Ag(I) could also partially displace Cu(I) from the Mb complex. At pH ≈ 6.5, the Mb binding selectivity follows the order Ag(I)≈Cu(I)>Ni(II)≈Zn(II)>Co(II)>>Mn(II)≈Pb(II)>Fe(II), and at pH 7.5 to 10.4 the order is Ag(I)>Cu(I)>Ni(II)>Co(II)>Zn(II)>Mn(II)≈Pb(II)>Fe(II). Breakdown curves of the disulfide reduced Cu(I) and Ag(I) complexes showed a correlation existed between their relative stability and their compact folded structure indicated by their CCS. Fluorescence spectroscopy, which allowed the determination of the binding constant, compared well with the TWIMS analyses, with the exception of the Ni(II) complex. [Figure not available: see fulltext.

The role of S(II) and Pb(II) in xanthate flotation of smithsonite: Surface properties and mechanism

NASA Astrophysics Data System (ADS)

Jia, Kai; Feng, Qiming; Zhang, Guofan; Ji, Wanying; Zhang, Wukai; Yang, Bingqian

2018-06-01

Smithsonite is a readily dissolvable carbonate mineral that is naturally hydrophilic, making recovery of this ore by flotation difficult. The flotation results showed that conditioning with only sodium sulfide (Na2S) did not successfully allow the smithsonite samples to float, whereas treatment with a combination of S(II), Pb(II) and xanthate (with Na2S as the sulfurizing reagent, lead ions (Pb(II)) as the activator, and xanthate as the collector) improved the flotation of smithsonite, achieving a mass recovery of 95.8%. A combination of analytical techniques, including X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), in conjunction with depth profiling, was used to investigate the chemical nature of the sulfur and lead species on the smithsonite surface. For S(II)-conditioned smithsonite, a layer of ZnS formed on the smithsonite (ZnCO3) substrates; this newly formed ZnS coating was amorphous or poorly crystallized. For smithsonite samples conditioned with S(II) and Pb(II), the microstructures and the phase constituents, obtained by AFM and XRD analyses, confirmed the formation of the PbS species with a cubic galena structure on the surface. XPS depth profiling showed that the PbS layer was 18-nm thick, which corresponds to 30 PbS molecular layers. This study presents direct evidence that the coating of the activation product, PbS, on the smithsonite surface was similar to a relatively thick galena layer, which led to successful flotation.

Angiotensin II and angiotensin II receptor blocker modulate the arrhythmogenic activity of pulmonary veins.

PubMed

Chen, Yi-Jen; Chen, Yao-Chang; Tai, Ching-Tai; Yeh, Hung-I; Lin, Cheng-I; Chen, Shih-Ann

2006-01-01

Angiotensin II receptor blockers (AIIRBs) have been shown to prevent atrial fibrillation. The pulmonary veins (PVs) are the most important focus for the generation of atrial fibrillation. The aim of this study was to evaluate whether angiotensin II or AIIRB may change the arrhythmogenic activity of the PVs. Conventional microelectrodes and whole-cell patch clamps were used to investigate the action potentials (APs) and ionic currents in isolated rabbit PV tissue and single cardiomyocytes before and after administering angiotensin II or losartan (AIIRB). In the tissue preparations, angiotensin II induced delayed after-depolarizations (1, 10, and 100 nM) and accelerated the automatic rhythm (10 and 100 nM). Angiotensin II (100 nM) prolonged the AP duration and increased the contractile force (10 and 100 nM). Losartan (1 and 10 microM) inhibited the automatic rhythm. Losartan (10 microM) prolonged the AP duration and reduced the contractile force (1 and 10 microM). Angiotensin II reduced the transient outward potassium current (I(to)) but increased the L-type calcium, delayed rectifier potassium (I(K)), transient inward (I(ti)), pacemaker, and Na(+)-Ca(2+) exchanger (NCX) currents in the PV cardiomyocytes. Losartan decreased the I(to), I(K), I(ti), and NCX currents. In conclusion, angiotensin II and AIIRB modulate the PV electrical activity, which may play a role in the pathophysiology of atrial fibrillation.

Simultaneous determination of Cd(II) and Pb(II) by differential pulse anodic stripping voltammetry based on graphite nanofibers-Nafion composite modified bismuth film electrode.

PubMed

Li, Dongyue; Jia, Jianbo; Wang, Jianguo

2010-12-15

A bismuth-film modified graphite nanofibers-Nafion glassy carbon electrode (BiF/GNFs-NA/GCE) was constructed for the simultaneous determination of trace Cd(II) and Pb(II). The electrochemical properties and applications of the modified electrode were studied. Operational parameters such as deposition potential, deposition time, and bismuth ion concentration were optimized for the purpose of determination of trace metal ions in 0.10 M acetate buffer solution (pH 4.5). Under optimal conditions, based on three times the standard deviation of the baseline, the limits of detection were 0.09 μg L(-1) for Cd(II) and 0.02 μg L(-1) for Pb(II) with a 10 min preconcentration. In addition, the BiF/GNFs-NA/GCE displayed good reproducibility and selectivity, making it suitable for the simultaneous determination of Cd(II) and Pb(II) in real sample such as river water and human blood samples. Copyright © 2010 Elsevier B.V. All rights reserved.

Potassium Supplementation Prevents Sodium Chloride Cotransporter Stimulation During Angiotensin II Hypertension.

PubMed

Veiras, Luciana C; Han, Jiyang; Ralph, Donna L; McDonough, Alicia A

2016-10-01

Angiotensin II (AngII) hypertension increases distal tubule Na-Cl cotransporter (NCC) abundance and phosphorylation (NCCp), as well as epithelial Na(+) channel abundance and activating cleavage. Acutely raising plasma [K(+)] by infusion or ingestion provokes a rapid decrease in NCCp that drives a compensatory kaliuresis. The first aim tested whether acutely raising plasma [K(+)] with a single 3-hour 2% potassium meal would lower NCCp in Sprague-Dawley rats after 14 days of AngII (400 ng/kg per minute). The potassium-rich meal neither decreased NCCp nor increased K(+) excretion. AngII-infused rats exhibited lower plasma [K(+)] versus controls (3.6±0.2 versus 4.5±0.1 mmol/L; P<0.05), suggesting that AngII-mediated epithelial Na(+) channel activation provokes K(+) depletion. The second aim tested whether doubling dietary potassium intake from 1% (A1K) to 2% (A2K) would prevent K(+) depletion during AngII infusion and, thus, prevent NCC accumulation. A2K-fed rats exhibited normal plasma [K(+)] and 2-fold higher K(+) excretion and plasma [aldosterone] versus A1K. In A1K rats, NCC, NCCpS71, and NCCpT53 abundance increased 1.5- to 3-fold versus controls (P<0.05). The rise in NCC and NCCp abundance was prevented in the A2K rats, yet blood pressure did not significantly decrease. Epithelial Na(+) channel subunit abundance and cleavage increased 1.5- to 3-fold in both A1K and A2K; ROMK (renal outer medulla K(+) channel abundance) abundance was unaffected by AngII or dietary K(+) In summary, the accumulation and phosphorylation of NCC seen during chronic AngII infusion hypertension is likely secondary to potassium deficiency driven by epithelial Na(+) channel stimulation. © 2016 American Heart Association, Inc.

Effect of biofilm coatings at metal-oxide/water interfaces II: Competitive sorption between Pb(II) and Zn(II) at Shewanella oneidensis/metal-oxide/water interfaces

DOE PAGES

Wang, Yingge; Gelabert, Alexandre; Michel, F. Marc; ...

2016-05-07

Competitive sorption of Pb(II) and Zn(II) on Shewanella oneidensis MR-1 biofilm-coated single-crystal α-Al 2O 3 (1 –1 0 2) and α-Fe 2O 3 (0 0 0 1) surfaces was investigated using long-period X-ray standing wave-florescence yield (LP-XSW-FY) spectroscopy. In situ partitioning of aqueous Pb(II) and Zn(II) between the biofilms and underlying metal-oxide substrates was probed following exposure of these complex interfaces to equi-molar Pb and Zn solutions (0.01 M NaNO 3 as background electrolyte, pH = 6.0, and 3-h equilibration time). At higher Pb and Zn concentrations (≥10 –5 M), more than 99% of these ions partitioned into the biofilmsmore » at S. oneidensis/α-Al 2O 3 (1 –1 0 2)/water interfaces, which is consistent with the partitioning behavior of both Pb(II) or Zn(II) in single-metal-ion experiments. Furthermore, no apparent competitive effects were found in this system at these relatively high metal-ion concentrations. However, at lower equi-molar concentrations (≤10 –6 M), Pb(II) and Zn(II) partitioning in the same system changed significantly compared to the single-metal-ion systems. The presence of Zn(II) decreased Pb(II) partitioning onto α-Al 2O 3 (1 –1 0 2) substantially (~52% to ~13% at 10 –7 M, and ~23% to ~5% at 10–6 M), whereas the presence of Pb(II) caused more Zn(II) to partition onto α-Al 2O 3 (1 –1 0 2) surfaces (~15% to ~28% at 10 –7 M, and ~1% to ~7% at 10 –6 M) .The higher observed partitioning of Zn(II) (~28%) at the α-Al 2O 3 (1 –1 0 2) surfaces compared to Pb(II) (~13%) in the mixed-metal-ion systems at the lowest concentration (10 –7 M) suggests that Zn(II) is slightly favored over Pb(II) for sorption sites on α-Al 2O 3 (1 –1 0 2) surfaces under our experimental conditions.« less

Selective aldosterone blockade prevents angiotensin II/salt-induced vascular inflammation in the rat heart.

PubMed

Rocha, Ricardo; Martin-Berger, Cynthia L; Yang, Pochang; Scherrer, Rachel; Delyani, John; McMahon, Ellen

2002-12-01

We studied the role of aldosterone (aldo) in myocardial injury in a model of angiotensin (Ang) II-hypertension. Wistar rats were given 1% NaCl (salt) to drink and randomized into one of the following groups (n = 10; treatment, 21 d): 1) vehicle control (VEH); 2) Ang II infusion (25 ng/min, sc); 3) Ang II infusion plus the selective aldo blocker, eplerenone (epl, 100 mg/kg.d, orally); 4) Ang II infusion in adrenalectomized (ADX) rats; and 5) Ang II infusion in ADX rats with aldo treatment (20 micro g/kg.d, sc). ADX rats received also dexamethasone (12 micro g/kg.d, sc). Systolic blood pressure increased with time in all treatment groups except the VEH group (VEH, 136 +/- 6; Ang II/NaCl, 203 +/- 12; Ang II/NaCl/epl, 196 +/- 10; Ang II/NaCl/ADX, 181 +/- 7; Ang II/NaCl/ADX/aldo, 236 +/- 8 mm Hg). Despite similar levels of hypertension, epl and ADX attenuated the increase in heart weight/body weight induced by Ang II. Histological examination of the hearts evidenced myocardial and vascular injury in the Ang II/salt (7 of 10 hearts with damage, P < 0.05 vs. VEH) and Ang II/salt/ADX/aldo groups (10 of 10 hearts with damage, P < 0.05). Injury included arterial fibrinoid necrosis, perivascular inflammation (primarily macrophages), and focal infarctions. Vascular lesions were associated with expression of the inflammatory mediators cyclooxygenase 2 (COX-2) and osteopontin in the media of coronary arteries. Myocardial injury, COX-2, and osteopontin expression were markedly attenuated by epl treatment (1 of 10 hearts with damage, P < 0.05 vs. Ang II/salt) and adrenalectomy (2 of 10 hearts with damage, P < 0.05 vs. Ang II/salt). Our data indicate that aldo plays a major role in Ang II-induced vascular inflammation in the heart and implicate COX-2 and osteopontin as potential mediators of the damage.

Manganese(II), iron(II), cobalt(II), and copper(II) complexes of an extended inherently chiral tris-bipyridyl cage.

PubMed

Perkins, David F; Lindoy, Leonard F; McAuley, Alexander; Meehan, George V; Turner, Peter

2006-01-17

Manganese(II), iron(II), cobalt(II), and copper(II) derivatives of two inherently chiral, Tris(bipyridyl) cages (L and L') of type [ML]-(PF(6))(2)(solvent)(n) and [FeL'](ClO(4))(2) are reported, where L is the hexa-tertiary butyl-substituted derivative of L'. These products were obtained by using the free cage and metal template procedures; the latter involved the reductive amination of the respective Tris-dialdehyde precursor complexes of iron(II), cobalt(II), or nickel(II). Electrochemical, EPR, and NMR studies have been used to probe the nature of the individual complexes. X-ray structures of the manganese(II), iron(II), and copper(II) complexes of L and the iron(II) complex of L' are presented; these are compared with the previously reported structures of the corresponding nickel(II) complex and metal-free cage (L). In each complex the metal cation occupies the cage's central cavity and is coordinated to six nitrogens from the three bipyridyl groups. The cations [MnL](2+) and [FeL](2+) are isostructural but both exhibit a different arrangement of the bound cage to that observed in the corresponding nickel(II) and copper(II) complexes. The latter have an exo-exo arrangement of the bridgehead nitrogen lone pairs, with the metal inducing a triple helical twist that extends approximately 22 A along the axial length of each complex. In contrast, [MnL](2+) and [FeL](2+) have their terminal nitrogen lone pairs directed endo, causing a significant change in the configuration of the bound ligand. In [FeL'](2+), the cage has both bridgehead nitrogen lone pairs orientated exo. Semiempirical calculations indicate that the observed endo-endo and exo-exo arrangements are of comparable energy.

The effect of sodium pertechnetate human carbonic anhydrase I and II

NASA Astrophysics Data System (ADS)

Sahin, Ali; Senturk, Murat

2017-04-01

The inhibitory effects of Na99mTcO4 (Sodium pertechnetate) on human erythrocyte carbonic anhydrase I and II activity were investigated. For this purpose, hCA I was initially purified 114,29-fold at a yield of 69,19 % and hCA II was initially purified 710,82-fold at a yield of 71,72 % using sepharose 4B-tyrosine-sulfanilamide affinity gel chromatography. The in vitro effect of this compound on hCA I and II isoenzyme were studied. It was detected in in vitro studies that the hCA I and II enzymes are inhibited due to Na99mTcO4.

Ion transport in goby intestine: cellular mechanism of urotensin II stimulation.

PubMed

Loretz, C A; Howard, M E; Siegel, A J

1985-08-01

The Na- and Cl-absorbing goby posterior intestinal epithelium is composed predominantly of mitochondria-rich, tall columnar cells. Glass intracellular microelectrode recording technique was applied to absorptive cells of this relatively leaky epithelium to measure apical cell membrane potential difference (psi mc) and apical membrane fractional resistance. As determined by ion-substitution studies, absorptive cells are characterized by a large, Ba2+-inhibitable apical K conductance, which is a major factor determining psi mc and smaller Cl and Na conductances. Inhibition of the apical Na-Cl-coupled influx directly by furosemide or indirectly by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine produced hyperpolarization of psi mc, consistent with the greater apical membrane conductance to Cl than Na. The urophysial neurosecretory peptide urotensin II, which stimulates Na-Cl-coupled absorption, markedly depolarized psi mc in posterior intestinal tissues from 5% seawater-adapted gobies. This response is consistent with a stimulatory effect of urotensin II at the apical membrane carrier rather than at the basolateral Na-K-ATPase. Urotensin II is without effect on psi mc in tissues from seawater-adapted fish and somatostatin, a natural analogue of urotensin II, is without effect on tissues from fish adapted to either salinity. This specificity parallels that determined using radiotracer fluxes.

Ca II and Na I absorption in the QSO S4 0248 + 430 due to an intervening galaxy

NASA Technical Reports Server (NTRS)

Womble, Donna S.; Junkkarinen, Vesa T.; Cohen, Ross D.; Burbidge, E. Margaret

1990-01-01

Observations of the QSO S4 0248 + 430 and a nearby anonymous galaxy are presented. Two absorption components are found in both Ca II H and K and Na I D1 and D2 at z(a) = 0.0515, 0.0523. Column densities of log N(Ca II) = 13.29, 13.50, and log N(Na I) = 13.79, 14.18 are found for z(a) = 0.0515, 0.0523 absorption systems, respectively. The column density ratios imply considerable calcium depletion and disk-type absorbing gas. At least one and possibly both absorption components are produced by high-velocity gas. A broadband image of the field shows an asymmetrical armlike feature or possible tidal tail covering and extending past the position of the QSO. The presence of this extended feature and the apparent difference between the absorption velocities and galaxy rotation velocity suggest that the absorbing gas is not ordinary disk gas, but rather is a result of tidal disruption.

Diffusion of Na(I), Cs(I), Sr(II) and Eu(III) in smectite rich natural clay.

PubMed

Kasar, Sharayu; Kumar, Sumit; Bajpai, R K; Tomar, B S

2016-01-01

Diffusion of Na(I), Cs(I), Sr(II) and Eu(III) in smectite rich natural clay, proposed as a backfill material in the Indian geological repository, was studied using the out-diffusion method. Radiotracers (22)Na, (137)Cs, (85)Sr and (154)Eu were used; the first three are carrier-free enabling experimental work at sub-micromolar metal ion concentration, and Eu(III) tracer (154)Eu was used at sub millimolar concentration. An out-diffusion methodology, wherein a thin planar source of radioactivity placed between two clay columns diffuses out, was used to obtain the apparent diffusion coefficient (Da) values. This methodology enabled determination of diffusion coefficient even for strongly sorbing (154)Eu. Da values for (22)Na, (137)Cs, (85)Sr and (154)Eu were 2.35 (±0.14) × 10(-11), 2.65 (±0.09) × 10(-12), 3.32 (±0.15) × 10(-11) and 1.23 (±0.15) × 10(-13) m(2) s(-1), respectively. Da values were found to be in fair agreement with literature data reported for similar mineralogical sediments. Sorption of radionuclides on the clay was also determined in the present study and differences in Da values were rationalized on the basis of sorption data. Distribution ratios (Kd) for Cs(I) and Eu(III) were higher than that for Sr(II), which in turn was higher than that for Na(I). Copyright © 2015 Elsevier Ltd. All rights reserved.

A magnetostructural study of linear NiII MnIII NiII, NiII CrIII NiII and triangular Ni(II)3 species containing (pyridine-2-aldoximato)nickel(II) unit as a building block.

PubMed

Weyhermüller, Thomas; Wagner, Rita; Khanra, Sumit; Chaudhuri, Phalguni

2005-08-07

Three trinuclear complexes, NiII MnIII NiII, NiII CrIII NiII and Ni(II)3 based on (pyridine-2-aldoximato)nickel(II) units are described. Two of them, and , contain metal-centers in linear arrangement, as is revealed by X-ray diffraction. Complex is a homonuclear complex in which the three nickel(II) centers are disposed in a triangular fashion. The compounds were characterized by various physical methods including cyclic voltammetric and variable-temperature (2-290 K) susceptibility measurements. Complexes and display antiferromagnetic exchange coupling of the neighbouring metal centers, while weak ferromagnetic spin exchange between the adjacent Ni II and Cr III ions in is observed. The experimental magnetic data were simulated by using appropriate models.

Average [O II] nebular emission associated with Mg II absorbers: dependence on Fe II absorption

NASA Astrophysics Data System (ADS)

Joshi, Ravi; Srianand, Raghunathan; Petitjean, Patrick; Noterdaeme, Pasquier

2018-05-01

We investigate the effect of Fe II equivalent width (W2600) and fibre size on the average luminosity of [O II] λλ3727, 3729 nebular emission associated with Mg II absorbers (at 0.55 ≤ z ≤ 1.3) in the composite spectra of quasars obtained with 3 and 2 arcsec fibres in the Sloan Digital Sky Survey. We confirm the presence of strong correlations between [O II] luminosity (L_{[O II]}) and equivalent width (W2796) and redshift of Mg II absorbers. However, we show L_{[O II]} and average luminosity surface density suffer from fibre size effects. More importantly, for a given fibre size, the average L_{[O II]} strongly depends on the equivalent width of Fe II absorption lines and found to be higher for Mg II absorbers with R ≡W2600/W2796 ≥ 0.5. In fact, we show the observed strong correlations of L_{[O II]} with W2796 and z of Mg II absorbers are mainly driven by such systems. Direct [O II] detections also confirm the link between L_{[O II]} and R. Therefore, one has to pay attention to the fibre losses and dependence of redshift evolution of Mg II absorbers on W2600 before using them as a luminosity unbiased probe of global star formation rate density. We show that the [O II] nebular emission detected in the stacked spectrum is not dominated by few direct detections (i.e. detections ≥3σ significant level). On an average, the systems with R ≥ 0.5 and W2796 ≥ 2 Å are more reddened, showing colour excess E(B - V) ˜ 0.02, with respect to the systems with R < 0.5 and most likely trace the high H I column density systems.

Syntheses, crystal structures, and magnetic properties of the oxalato-bridged mixed-valence complexes (FeII(bpm)3]2[FeIII2(ox)5].8H2O and FeII(bpm)3Na(H2O)2Fe(ox)(3).4H2O (bpm = 2,2'-bipyrimidine).

PubMed

Armentano, D; De Munno, G; Faus, J; Lloret, F; Julve, M

2001-02-12

The preparation and crystal structures of two oxalato-bridged FeII-FeIII mixed-valence compounds, [FeII(bpm)3]2[FeIII2(ox)5].8H2O (1) and FeII(bpm)3Na(H2O)2FeIII(ox)(3).4H2O (2) (bpm = 2,2'-bipyrimidine; ox = oxalate dianion) are reported here. Complex 1 crystallizes in the triclinic system, space group P1, with a = 10.998(2) A, b = 13.073(3) A, c = 13.308(3) A, alpha = 101.95(2) degrees, beta = 109.20(2) degrees, gamma = 99.89(2) degrees, and Z = 1. Complex 2 crystallizes in the monoclinic system, space group P2(1)/c, with a = 12.609(2) A, b = 19.670(5) A, c = 15.843(3) A, beta = 99.46(1) degrees, and Z = 4. The structure of complex 1 consists of centrosymmetric oxalato-bridged dinuclear high-spin iron(III) [Fe2(ox)5]2- anions, tris-chelated low-spin iron(II) [Fe(bpm)3]2+ cations, and lattice water molecules. The iron atoms are hexacoordinated: six oxygen atoms (iron(III)) from two bidentate and one bisbidentate oxalato ligands and six nitrogen atoms (iron(II)) from three bidentate bpm groups. The Fe(III)-O(ox) and Fe(II)-N(bpm) bond distances vary in the ranges 1.967(3)-2.099(3) and 1.967(4)-1.995(3) A, respectively. The iron(III)-iron(III) separation across the bridging oxalato is 5.449(2) A, whereas the shortest intermolecular iron(III)-iron(II) distance is 6.841(2) A. The structure of complex 2 consists of neutral heterotrinuclear Fe(bpm)2Na(H2O)2Fe(ox)3 units and water molecules of crystallization. The tris-chelated low-spin iron(II) ([Fe(bpm)3]2+) and high-spin iron(III) ([Fe(ox)3]3-) entities act as bidentate ligands (through two bpm-nitrogen and two oxalato-oxygen atoms, respectively) toward the univalent sodium cation, yielding the trinuclear (bpm)2Fe(II)-bpm-Na(I)-ox-Fe(III)(ox)2 complex. Two cis-coordinated water molecules complete the distorted octahedral surrounding of the sodium atom. The ranges of the Fe(II)-N(bpm) and Fe(III)-O(ox) bond distances [1.968(6)-1.993(5) and 1.992(6)-2.024(6) A, respectively] compare well with those observed in 1. The Na

Macrocyclic receptor showing extremely high Sr(II)/Ca(II) and Pb(II)/Ca(II) selectivities with potential application in chelation treatment of metal intoxication.

PubMed

Ferreirós-Martínez, Raquel; Esteban-Gómez, David; Tóth, Éva; de Blas, Andrés; Platas-Iglesias, Carlos; Rodríguez-Blas, Teresa

2011-04-18

Herein we report a detailed investigation of the complexation properties of the macrocyclic decadentate receptor N,N'-Bis[(6-carboxy-2-pyridil)methyl]-4,13-diaza-18-crown-6 (H(2)bp18c6) toward different divalent metal ions [Zn(II), Cd(II), Pb(II), Sr(II), and Ca(II)] in aqueous solution. We have found that this ligand is especially suited for the complexation of large metal ions such as Sr(II) and Pb(II), which results in very high Pb(II)/Ca(II) and Pb(II)/Zn(II) selectivities (in fact, higher than those found for ligands widely used for the treatment of lead poisoning such as ethylenediaminetetraacetic acid (edta)), as well as in the highest Sr(II)/Ca(II) selectivity reported so far. These results have been rationalized on the basis of the structure of the complexes. X-ray crystal diffraction, (1)H and (13)C NMR spectroscopy, as well as theoretical calculations at the density functional theory (B3LYP) level have been performed. Our results indicate that for large metal ions such as Pb(II) and Sr(II) the most stable conformation is Δ(δλδ)(δλδ), while for Ca(II) our calculations predict the Δ(λδλ)(λδλ) form being the most stable one. The selectivity that bp18c6(2-) shows for Sr(II) over Ca(II) can be attributed to a better fit between the large Sr(II) ions and the relatively large crown fragment of the ligand. The X-ray crystal structure of the Pb(II) complex shows that the Δ(δλδ)(δλδ) conformation observed in solution is also maintained in the solid state. The Pb(II) ion is endocyclically coordinated, being directly bound to the 10 donor atoms of the ligand. The bond distances to the donor atoms of the pendant arms (2.55-2.60 Å) are substantially shorter than those between the metal ion and the donor atoms of the crown moiety (2.92-3.04 Å). This is a typical situation observed for the so-called hemidirected compounds, in which the Pb(II) lone pair is stereochemically active. The X-ray structures of the Zn(II) and Cd(II) complexes show that

Structural, spectroscopic and thermal characterization of 2-tert-butylaminomethylpyridine-6-carboxylic acid methylester and its Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and UO(2)(II) complexes.

PubMed

Mohamed, Gehad G; El-Gamel, Nadia E A

2005-04-01

Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and UO(2)(II) complexes with the ligand 2-tert-butylaminomethylpyridine-6-carboxylic acid methylester (HL(2)) have been prepared and characterized by elemental analyses, molar conductance, magnetic moment, thermal analysis and spectral data. 1:1 M:HL(2) complexes, with the general formula [M(HL(2))X(2)].nH(2)O (where M = Co(II) (X = Cl, n = 0), Ni(II) (X = Cl, n = 3), Cu(II) (grey colour, X = AcO, n = 1), Cu(II) (yellow colour, X = Cl, n = 0) and Zn(II) (X = Br, n = 0). In addition, the Fe(III) and UO(2)(II) complexes of the type 1:2 M:HL(2) and with the formulae [Fe(L(2))(2)]Cl and [UO(2)(HL(2))(2)](NO(3))(2) are prepared. From the IR data, it is seen that HL(2) ligand behaves as a terdentate ligand coordinated to the metal ions via the pyridyl N, carboxylate O and protonated NH group; except the Fe(III) complex, it coordinates via the deprotonated NH group. This is supported by the molar conductance data, which show that all the complexes are non-electrolytes, while the Fe(III) and UO(2)(II) complexes are 1:1 electrolytes. IR and H1-NMR spectral studies suggest a similar behaviour of the Zn(II) complex in solid and solution states. From the solid reflectance spectral data and magnetic moment measurements, the complexes have a trigonal bipyramidal (Co(II), Ni(II), Cu(II) and Zn(II) complexes) and octahedral (Fe(III), UO(2)(II) complexes) geometrical structures. The thermal behaviour of the complexes is studied and the different dynamic parameters are calculated applying Coats-Redfern equation.

Solid Phase Extraction of Trace Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) Ions in Beverages on Functionalized Polymer Microspheres Prior to Flame Atomic Absorption Spectrometric Determinations.

PubMed

Berber, Hale; Alpdogan, Güzin

2017-01-01

In this study, poly(glycidyl methacrylate-methyl methacrylate-divinylbenzene) was synthesized in the form of microspheres, and then functionalized by 2-aminobenzothiazole ligand. The sorption properties of these functionalized microspheres were investigated for separation, preconcentration and determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions using flame atomic absorption spectrometry. The optimum pH values for quantitative sorption were 2 - 4, 5 - 8, 6 - 8, 4 - 6, 2 - 6 and 2 - 3 for Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II), respectively, and also the highest sorption capacity of the functionalized microspheres was found to be for Cu(II) with the value of 1.87 mmol g -1 . The detection limits (3σ; N = 6) obtained for the studied metals in the optimal conditions were observed in the range of 0.26 - 2.20 μg L -1 . The proposed method was successfully applied to different beverage samples for the determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions, with the relative standard deviation of <3.7%.

Removal of Pb(II) from wastewater using Al2O3-NaA zeolite composite hollow fiber membranes synthesized from solid waste coal fly ash.

PubMed

Zhu, Li; Ji, Jiayou; Wang, Shulin; Xu, Chenxi; Yang, Kun; Xu, Man

2018-09-01

Al 2 O 3 -NaA zeolite composite hollow fiber membranes were successfully fabricated via hydrothermal synthesis by using industrial solid waste coal fly ash and porous Al 2 O 3 hollow fiber supports. The as-synthesized Al 2 O 3 -NaA zeolite composite hollow fiber membranes were then characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The hollow fiber membranes were used to remove lead ions (Pb(II), 50 mg L -1 ) from synthetic wastewater with a removal efficiency of 99.9% at 0.1 MPa after 12 h of filtration. This study showed that the Al 2 O 3 -NaA zeolite composite hollow fiber membranes (the pore size of the membrane was about 0.41 nm in diameter) synthesized from coal fly ash could be efficiently used for treating low concentration Pb(II) wastewater. It recycled solid waste coal fly ash not only to solve its environment problems, but also can produce high-value Al 2 O 3 -NaA zeolite composite hollow fiber membranes for separation application in treating wastewater containing Pb(II). Copyright © 2018 Elsevier Ltd. All rights reserved.

Metal ion promoted hydrogels for bovine serum albumin adsorption: Cu(II) and Co(II) chelated poly[(N-vinylimidazole)-maleic acid].

PubMed

Pekel, Nursel; Salih, Bekir; Güven, Olgun

2005-05-10

Poly[(N-vinylimidazole)-maleic acid] (poly(VIm-MA)), copolymeric hydrogels were prepared by gamma-irradiating ternary mixtures of N-vinylimidazole-maleic acid-water in a (60)Co-gamma source. Cu(II) and Co(II) ions were chelated within the gels at pH=5.0. The maximum adsorption capacity of the gels were 3.71 mmol/g dry gel for Cu(II) and 1.25 mmol/g dry gel for Co(II) at pH=5.0. The swelling ratios of the gels were 1200% for poly(VIm-MA), 60 and 45% for Cu(II) and Co(II)-chelated poly(VIm-MA) gels at pH=5.0 in acetate buffer solution. These affinity gels with different swelling ratios for plain poly(VIm-MA), Cu(II)-, and Co(II)-chelated poly(VIm-MA), in acetate and phosphate buffers were used in the bovine serum albumin (BSA) adsorption/desorption studies in batch reactor. The maximum BSA adsorption capacities of the gels were 0.38 g/g dry gel for plain, 0.88 g/g dry gel for Cu(II)-chelated poly(VIm-MA) and 1.05 g/g dry gel for Co(II)-chelated poly(VIm-MA) gels. Adsorption capacity of BSA by the gels was reduced dramatically by increasing the ionic strength adjusted with NaCl. More than 95% of BSA were desorbed in 10 h in desorption medium containing 0.1M of EDTA for metal ion-chelated gels at pH=4.7.

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.

Cr(II) reactivity of taurine/alpha-ketoglutarate dioxygenase.

PubMed

Grzyska, Piotr K; Hausinger, Robert P

2007-11-26

The interaction of CrII with taurine/alpha-ketoglutarate (alphaKG) dioxygenase (TauD) was examined. CrII replaces FeII and binds stoichiometrically with alphaKG to the FeII/alphaKG binding site of the protein, with additional CrII used to generate a chromophore attributed to a CrIII-semiquinone in a small percentage of the sample. Formation of the latter oxygen-sensitive species requires the dihydroxyphenylalanine (DOPA) quinone form of Tyr-73. This preformed side chain is generated by intracellular self-hydroxylation of Tyr-73 to form DOPA, which is subsequently oxidized to the quinone. No chromophore is generated when using NaBH4-treated sample, protein isolated from anaerobically grown cells, inactive TauD variants that are incapable of self-hydroxylation, or the Y73F active mutant of TauD. A CrIII-DOPA semiquinone also was observed in the herbicide hydroxylase SdpA.

Small Diameter Bomb Increment II (SDB II)

DTIC Science & Technology

2015-12-01

Selected Acquisition Report ( SAR ) RCS: DD-A&T(Q&A)823-439 Small Diameter Bomb Increment II (SDB II) As of FY 2017 President’s Budget Defense...Acquisition Management Information Retrieval (DAMIR) March 23, 2016 16:19:13 UNCLASSIFIED SDB II December 2015 SAR March 23, 2016 16:19:13 UNCLASSIFIED...Document OSD - Office of the Secretary of Defense O&S - Operating and Support PAUC - Program Acquisition Unit Cost SDB II December 2015 SAR March 23

Synthesis, investigation and spectroscopic characterization of piroxicam ternary complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with glycine and DL-phenylalanine.

PubMed

Mohamed, Gehad G; El-Gamel, Nadia E A

2004-11-01

The ternary piroxicam (Pir; 4-hydroxy-2-methyl-N-(2-pyridyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide) complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with various amino acids (AA) such as glycine (Gly) or DL-phenylalanine (PhA) were prepared and characterized by elemental analyses, molar conductance, IR, UV-Vis, magnetic moment, diffuse reflectance and X-ray powder diffraction. The UV-Vis spectra of Pir and the effect of metal chelation on the different interligand transitions are discussed in detailed manner. IR and UV-Vis spectra confirm that Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine-N and carbonyl group of the amide moiety. Gly molecule acted as a uninegatively monodentate ligand and coordinate to the metal ions through its carboxylic group, in addition PhA acted as a uninegatively bidentate ligand and coordinate to the metal ions through its carboxylic and amino groups. All the chelates have octahedral geometrical structures while Cu(II)- and Zn(II)-ternary chelates with PhA have square planar geometrical structures. The molar conductance data reveal that most of these chelates are non electrolytes, while Fe(III)-Pir-Gly, Co(II)-, Ni(II)-, Cu(II)- and Zn(II)-Pir-PhA chelates were 1:1 electrolytes. X-ray powder diffraction is used as a new tool to estimate the crystallinity of chelates as well as to elucidate their geometrical structures.

Synthesis, investigation and spectroscopic characterization of piroxicam ternary complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with glycine and DL-phenylalanine

NASA Astrophysics Data System (ADS)

Mohamed, Gehad G.; El-Gamel, Nadia E. A.

2004-11-01

The ternary piroxicam (Pir; 4-hydroxy-2-methyl- N-(2-pyridyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide) complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with various amino acids (AA) such as glycine (Gly) or DL-phenylalanine (PhA) were prepared and characterized by elemental analyses, molar conductance, IR, UV-Vis, magnetic moment, diffuse reflectance and X-ray powder diffraction. The UV-Vis spectra of Pir and the effect of metal chelation on the different interligand transitions are discussed in detailed manner. IR and UV-Vis spectra confirm that Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine- N and carbonyl group of the amide moiety. Gly molecule acted as a uninegatively monodentate ligand and coordinate to the metal ions through its carboxylic group, in addition PhA acted as a uninegatively bidentate ligand and coordinate to the metal ions through its carboxylic and amino groups. All the chelates have octahedral geometrical structures while Cu(II)- and Zn(II)-ternary chelates with PhA have square planar geometrical structures. The molar conductance data reveal that most of these chelates are non electrolytes, while Fe(III)-Pir-Gly, Co(II)-, Ni(II)-, Cu(II)- and Zn(II)-Pir-PhA cheletes were 1:1 electrolytes. X-ray powder diffraction is used as a new tool to estimate the crystallinity of chelates as well as to elucidate their geometrical structures.

Synthesis, spectroscopic characterization, thermal analysis and electrical conductivity studies of Mg(II), Ca(II), Sr(II) and Ba(II) vitamin B2 complexes

NASA Astrophysics Data System (ADS)

Refat, Moamen S.; Moussa, Mohamed A. A.; Mohamed, Soha F.

2011-05-01

Riboflavin (RF) complexes of Mg(II), Ca(II), Sr(II) and Ba(II) were successfully synthesized. Structures of metal complexes obtained were confirmed and characterized by elemental analysis, molar conductance, and infrared spectra. DC electrical conductivity measurements indicated that the alkaline earth metal (II) complexes of RF ligand are non-electrolytes. Elemental analysis of chelates suggest that the metal(II) ligand ratio is 1:2 with structure formula as [M(RF) 2( X) 2]· nH 2O. Infrared assignments clearly show that RF ligand coordinated as a bidentate feature through azomethine nitrogen of pyrazine ring and C dbnd O of pyrimidine-2,4-dione. Thermal analyses of Mg(II), Ca(II), Sr(II) and Ba(II) complexes were investigated using (TG/DSC) under atmospheric nitrogen between 30 and 800 °C. The surface morphology of the complexes was studied by SEM. The electrical conductivities of RF and its metal complexes were also measured with DC electrical conductivity in the temperature range from room to 483 K.

CrII Reactivity of Taurine/α-Ketoglutarate Dioxygenase

PubMed Central

Grzyska, Piotr K.; Hausinger, Robert P.

2008-01-01

The interaction of CrII with taurine/α-ketoglutarate (αKG) dioxygenase (TauD) was examined. CrII replaces FeII and binds stoichiometrically with αKG to the FeII/αKG-binding site of the protein, with additional CrII used to generate a chromophore attributed to a CrIII-semiquinone in a small percentage of the sample. Formation of the latter oxygen -sensitive species requires the dihydroxyphenylalanine (DOPA) quinone form of Tyr-73. This pre-formed side chain is generated by intracellular self-hydroxylation of Tyr-73 to form DOPA, which is subsequently oxidized to the quinone. No chromophore is generated when using NaBH4-treated sample, protein isolated from anaerobically grown cells, inactive TauD variants that are incapable of self-hydroxylation, or the Y73F active mutant of TauD. A CrIII-DOPA semiquinone also was observed in the herbicide hydroxylase SdpA. PMID:17973473

Chitosan film loaded with silver nanoparticles-sorbent for solid phase extraction of Al(III), Cd(II), Cu(II), Co(II), Fe(III), Ni(II), Pb(II) and Zn(II).

PubMed

Djerahov, Lubomir; Vasileva, Penka; Karadjova, Irina; Kurakalva, Rama Mohan; Aradhi, Keshav Krishna

2016-08-20

The present study describes the ecofriendly method for the preparation of chitosan film loaded with silver nanoparticles (CS-AgNPs) and application of this film as efficient sorbent for separation and enrichment of Al(III), Cd(II), Cu(II), Co(II), Fe(III), Ni(II), Pb(II) and Zn(II). The stable CS-AgNPs colloid was prepared by dispersing the AgNPs sol in chitosan solution at appropriate ratio and further used to obtain a cast film with very good stability under storage and good mechanical strength for easy handling in aqueous medium. The incorporation of AgNPs in the structure of CS film and interaction between the polymer matrix and nanoparticles were confirmed by UV-vis and FTIR spectroscopy. The homogeneously embedded AgNPs (average diameter 29nm, TEM analysis) were clearly observed throughout the film by SEM. The CS-AgNPs nanocomposite film shows high sorption activity toward trace metals under optimized chemical conditions. The results suggest that the CS-AgNPs nanocomposite film can be feasibly used as a novel sorbent material for solid-phase extraction of metal pollutants from surface waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Collaborative Research to Optimize Warfighter Nutrition II (CROWN II)

DTIC Science & Technology

2016-09-01

Award Number: W81XWH-14-1-0335 TITLE: Collaborative Research to Optimize Warfighter Nutrition II (CROWN II) PRINCIPAL INVESTIGATOR: Jennifer C...2016 4. TITLE AND SUBTITLE Collaborative Research to Optimize Warfighter Nutrition II (CROWN II) 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1...has been forged between USARIEM and Pennington Biomedical Research Center (PBRC) since 1988. Objective: CROWN II conducts research in nutrition

Coordination behavior of tetraaza [N4] ligand towards Co(II), Ni(II), Cu(II), Cu(I) and Pd(II) complexes: Synthesis, spectroscopic characterization and anticancer activity

NASA Astrophysics Data System (ADS)

El-Boraey, Hanaa A.

2012-11-01

Novel eight Co(II), Ni(II), Cu(II), Cu(I) and Pd(II) complexes with [N4] ligand (L) i.e. 2-amino-N-{2-[(2-aminobenzoyl)amino]ethyl}benzamide have been synthesized and structurally characterized by elemental analysis, spectral, thermal (TG/DTG), magnetic, and molar conductivity measurements. On the basis of IR, mass, electronic and EPR spectral studies an octahedral geometry has been proposed for Co(II), Ni(II) complexes and Cu(II) chloride complex, square-pyramidal for Cu(I) bromide complex. For Cu(II) nitrate complex (6), Pd(II) complex (8) square planar geometry was proposed. The EPR data of Cu(II) complexes in powdered form indicate dx2-y2 ground state of Cu(II) ion. The antitumor activity of the synthesized ligand and some selected metal complexes has been studied. The palladium(II) complex (8) was found to display cytotoxicity (IC50 = 25.6 and 41 μM) against human breast cancer cell line MCF-7 and human hepatocarcinoma HEPG2 cell line.

Synthesis, characterization and anti-microbial evaluation of Cu(II), Ni(II), Pt(II) and Pd(II) sulfonylhydrazone complexes; 2D-QSAR analysis of Ni(II) complexes of sulfonylhydrazone derivatives

NASA Astrophysics Data System (ADS)

Özbek, Neslihan; Alyar, Saliha; Alyar, Hamit; Şahin, Ertan; Karacan, Nurcan

2013-05-01

Copper(II), nickel(II), platinum(II) and palladium(II) complexes with 2-hydroxy-1-naphthaldehyde-N-methylpropanesulfonylhydrazone (nafpsmh) derived from propanesulfonic acid-1-methylhydrazide (psmh) were synthesized, their structure were identified, and antimicrobial activity of the compounds was screened against three Gram-positive and three Gram-negative bacteria. The results of antimicrobial studies indicate that Pt(II) and Pd(II) complexes showed the most activity against all bacteria. The crystal structure of 2-hydroxy-1-naphthaldehyde-N-methylpropanesulfonylhydrazone (nafpsmh) was also investigated by X-ray analysis. A series of Ni(II) sulfonyl hydrazone complexes (1-33) was synthesized and tested in vitro against Escherichia coli and Staphylococcus aureus. Their antimicrobial activities were used in the QSAR analysis. Four-parameter QSAR models revealed that nucleophilic reaction index for Ni and O atoms, and HOMO-LUMO energy gap play key roles in the antimicrobial activity.

Dynamic free energy surfaces for sodium diffusion in type II silicon clathrates.

PubMed

Slingsby, J G; Rorrer, N A; Krishna, L; Toberer, E S; Koh, C A; Maupin, C M

2016-02-21

Earth abundant semiconducting type II Si clathrates have attracted attention as photovoltaic materials due to their wide band gaps. To realize the semiconducting properties of these materials, guest species that arise during the synthesis process must be completely evacuated from the host cage structure post synthesis. A common guest species utilized in the synthesis of Si clathrates is Na (metal), which templates the clathrate cage formation. Previous experimental investigations have identified that it is possible to evacuate Na from type II clathrates to an occupancy of less than 1 Na per unit cell. This work investigates the energetics, kinetics, and resulting mechanism of Na diffusion through type II Si clathrates by means of biased molecular dynamics and kinetic Monte Carlo simulations. Well-tempered metadynamics has been used to determine the potential of mean force for Na moving between clathrate cages, from which the thermodynamic preferences and transition barrier heights have been obtained. Kinetic Monte Carlo simulations based on the metadynamics results have identified the mechanism of Na diffusion in type II Si clathrates. The overall mechanism consists of a coupled diffusive process linked via electrostatic guest-guest interactions. The large occupied hexakaidechedral cages initially empty their Na guests to adjacent empty large cages, thereby changing the local electrostatic environment around the occupied small pentagonal dodecahedral cages and increasing the probability of Na guests to leave the small cages. This coupled process continues through the cross-over point that is identified as the point where large and small cages are equally occupied by Na guests. Further Na removal results in the majority of guests residing in the large cages as opposed to the small cages, in agreement with experiments, and ultimately a Na free structure.

Synthesis, spectroscopic characterization, first order nonlinear optical properties and DFT calculations of novel Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes with 1,3-diphenyl-4-phenylazo-5-pyrazolone ligand

NASA Astrophysics Data System (ADS)

Abdel-Latif, Samir A.; Mohamed, Adel A.

2018-02-01

Novel Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) metal ions with 1,3-diphenyl-4-phenylazo-5-pyrazolone (L) have been prepared and characterized using different analytical and spectroscopic techniques. 1:1 Complexes of Mn(II), Co(II) and Zn(II) are distorted octahedral whereas Ni(II) complex is square planar and Cu(II) is distorted trigonal bipyramid. 1:2 Complexes of Mn(II), Co(II), Cu(II) and Zn(II) are distorted trigonal bipyramid whereas Ni(II) complex is distorted tetrahedral. All complexes behave as non-ionic in dimethyl formamide (DMF). The electronic structure and nonlinear optical parameters (NLO) of the complexes were investigated theoretically at the B3LYP/GEN level of theory. Molecular stability and bond strengths have been investigated by applying natural bond orbital (NBO) analysis. The geometries of the studied complexes are non-planner. DFT calculations have been also carried out to calculate the global properties; hardness (η), global softness (S) and electronegativity (χ). The calculated small energy gap between HOMO and LUMO energies shows that the charge transfer occurs within the complexes. The total static dipole moment (μtot), the mean polarizability (<α>), the anisotropy of the polarizability (Δα) and the mean first-order hyperpolarizability (<β>) were calculated and compared with urea as a reference material. The complexes show implying optical properties.

Nickel(II) biosorption from aqueous solutions by shrimp head biomass.

PubMed

Hernández-Estévez, Alejandro; Cristiani-Urbina, Eliseo

2014-11-01

The present study evaluates the capacity of shrimp (Farfantepenaeus aztecus) head to remove toxic Ni(II) ions from aqueous solutions. Relevant parameters that could affect the biosorption process, such as shrimp head pretreatment, solution pH level, contact time and initial Ni(II) concentration, were studied in batch systems. An increase in Ni(II) biosorption capacity and a reduction in the time required to reach Ni(II) biosorption equilibrium was manifested by shrimp head biomass pretreated by boiling in 0.5 N NaOH for 15 min; this biomass was thereafter denominated APSH. The optimum biosorption level of Ni(II) ions onto APSH was observed at pH 7.0. Biosorption increased significantly with rising initial Ni(II) concentration. In terms of biosorption dynamics, the pseudo-second-order kinetic model described Ni(II) biosorption onto APSH best. The equilibrium data adequately fitted the Langmuir isotherm model within the studied Ni(II) ion concentration range. According to this isotherm model, the maximum Ni(II) biosorption capacity of APSH was 104.22 mg/g. Results indicate that APSH could be used as a low-cost, environmentally friendly, and promising biosorbent with high biosorption capacity to remove Ni(II) from aqueous solutions.

Chelation of Cu(II), Zn(II), and Fe(II) by tannin constituents of selected edible nuts.

PubMed

Karamać, Magdalena

2009-12-22

The tannin fractions isolated from hazelnuts, walnuts and almonds were characterised by colorimetric assays and by an SE-HPLC technique. The complexation of Cu(II) and Zn(II) was determined by the reaction with tetramethylmurexide, whereas for Fe(II), ferrozine was employed. The walnut tannins exhibited a significantly weaker reaction with the vanillin/HCl reagent than hazelnut and almond tannins, but the protein precipitation capacity of the walnut fraction was high. The SE-HPLC chromatogram of the tannin fraction from hazelnuts revealed the presence of oligomers with higher molecular weights compared to that of almonds. Copper ions were most effectively chelated by the constituents of the tannin fractions of hazelnuts, walnuts and almonds. At a 0.2 mg/assay addition level, the walnut tannins complexed almost 100% Cu(II). The Fe(II) complexation capacities of the tannin fractions of walnuts and hazelnuts were weaker in comparison to that of the almond tannin fraction, which at a 2.5 mg/assay addition level, bound Fe(II) by approximately 90%. The capacity to chelate Zn(II) was quite varied for the different nut tannin fractions: almond tannins bound as much as 84% Zn(II), whereas the value for walnut tannins was only 8.7%; and for hazelnut tannins, no Zn(II) chelation took place at the levels tested.

Chelation of Cu(II), Zn(II), and Fe(II) by Tannin Constituents of Selected Edible Nuts

PubMed Central

Karamać, Magdalena

2009-01-01

The tannin fractions isolated from hazelnuts, walnuts and almonds were characterised by colorimetric assays and by an SE-HPLC technique. The complexation of Cu(II) and Zn(II) was determined by the reaction with tetramethylmurexide, whereas for Fe(II), ferrozine was employed. The walnut tannins exhibited a significantly weaker reaction with the vanillin/HCl reagent than hazelnut and almond tannins, but the protein precipitation capacity of the walnut fraction was high. The SE-HPLC chromatogram of the tannin fraction from hazelnuts revealed the presence of oligomers with higher molecular weights compared to that of almonds. Copper ions were most effectively chelated by the constituents of the tannin fractions of hazelnuts, walnuts and almonds. At a 0.2 mg/assay addition level, the walnut tannins complexed almost 100% Cu(II). The Fe(II) complexation capacities of the tannin fractions of walnuts and hazelnuts were weaker in comparison to that of the almond tannin fraction, which at a 2.5 mg/assay addition level, bound Fe(II) by ~90%. The capacity to chelate Zn(II) was quite varied for the different nut tannin fractions: almond tannins bound as much as 84% Zn(II), whereas the value for walnut tannins was only 8.7%; and for hazelnut tannins, no Zn(II) chelation took place at the levels tested. PMID:20054482

Type II Cepheids: evidence for Na-O anticorrelation for BL Her type stars?

NASA Astrophysics Data System (ADS)

Kovtyukh, V.; Yegorova, I.; Andrievsky, S.; Korotin, S.; Saviane, I.; Lemasle, B.; Chekhonadskikh, F.; Belik, S.

2018-06-01

The chemical composition of 28 Population II Cepheids and one RR Lyrae variable has been studied using high-resolution spectra. The chemical composition of W Vir variable stars (with periods longer than 8 d) is typical for the halo and thick disc stars. However, the chemical composition of BL Her variables (with periods of 0.8-4 d) is drastically different, although it does not differ essentially from that of the stars belonging to globular clusters. In particular, the sodium overabundance ([Na/Fe] ≈ 0.4) is reported for most of these stars, and the Na-O anticorrelation is also possible. The evolutionary tracks for BL Her variables (with a progenitor mass value of 0.8 solar masses) indicate that mostly helium-overabundant stars (Y = 0.30-0.35) can fall into the instability strip region. We suppose that it is the helium overabundance that accounts not only for the existence of BL Her variable stars but also for the observed abnormalities in the chemical composition of this small group of pulsating variables.

Na+ channel regulation by Ca2+/calmodulin and Ca2+/calmodulin-dependent protein kinase II in guinea-pig ventricular myocytes†

PubMed Central

Aiba, Takeshi; Hesketh, Geoffrey G.; Liu, Ting; Carlisle, Rachael; Villa-Abrille, Maria Celeste; O'Rourke, Brian; Akar, Fadi G.; Tomaselli, Gordon F.

2010-01-01

Aims Calmodulin (CaM) regulates Na+ channel gating through binding to an IQ-like motif in the C-terminus. Ca2+/CaM-dependent protein kinase II (CaMKII) regulates Ca2+ handling, and chronic overactivity of CaMKII is associated with left ventricular hypertrophy and dysfunction and lethal arrhythmias. However, the acute effects of Ca2+/CaM and CaMKII on cardiac Na+ channels are not fully understood. Methods and results Purified NaV1.5–glutathione-S-transferase fusion peptides were phosphorylated in vitro by CaMKII predominantly on the I–II linker. Whole-cell voltage-clamp was used to measure Na+ current (INa) in isolated guinea-pig ventricular myocytes in the absence or presence of CaM or CaMKII in the pipette solution. CaMKII shifted the voltage dependence of Na+ channel availability by ≈+5 mV, hastened recovery from inactivation, decreased entry into intermediate or slow inactivation, and increased persistent (late) current, but did not change INa decay. These CaMKII-induced changes of Na+ channel gating were completely abolished by a specific CaMKII inhibitor, autocamtide-2-related inhibitory peptide (AIP). Ca2+/CaM alone reproduced the CaMKII-induced changes of INa availability and the fraction of channels undergoing slow inactivation, but did not alter recovery from inactivation or the magnitude of the late current. Furthermore, the CaM-induced changes were also completely abolished by AIP. On the other hand, cAMP-dependent protein kinase A inhibitors did not abolish the CaM/CaMKII-induced alterations of INa function. Conclusion Ca2+/CaM and CaMKII have distinct effects on the inactivation phenotype of cardiac Na+ channels. The differences are consistent with CaM-independent effects of CaMKII on cardiac Na+ channel gating. PMID:19797425

Synthesis, characterization, nucleic acid interactions and photoluminescent properties of methaniminium hydrazone Schiff base and its Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes

NASA Astrophysics Data System (ADS)

Sennappan, M.; Murali Krishna, P.; Hosamani, Amar A.; Hari Krishna, R.

2018-07-01

An environmental benign and efficient reaction was carried out via amine exchange and condensation reaction in water and methanol mixture (3:1) and absence of catalyst between 1-[3-(2-hydroxy benzylidene)amine)phenyl]ethanone and benzhydrazide yields methaniminium hydrazone Schiff base in high yield. The prepared ligand was structurally characterized by using single crystal XRD, elemental analysis and spectroscopy (UV-Vis, FT-IR, LC-MS and NMR) techniques. The crystal data indicates the ligand crystallizes in orthorhombic system with Pna21 space group. Further, the ligand was used in synthesis of mononuclear Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes and were characterized by elemental analysis, magnetic moment and spectroscopy (UV-Vis, FT-IR and ESR) studies. The spectral data showed that ligand is coordinated to the metal ion through azomethine nitrogen and methaniminium nitrogen. The DNA binding absorption titrations reveals that, ligand, L and its metal complexes, 1-6 are avid binders to CT- DNA. The apparent binding constant values of compounds are in the order of 106 M-1. The nuclease activity of ligand, L and its metal complexes, 1-6 were investigated by gel electrophoresis method using pUC18 DNA. The photoluminescent properties of the methaniminium hydrazone ligand, L and its various metal complexes, 1-6 were investigated. The emission spectra of both ligand (L) and metal complexes (1-6) exhibits emission in the range of blue to red.

Spectroscopic and mycological studies of Co(II), Ni(II) and Cu(II) complexes with 4-aminoantipyrine derivative

NASA Astrophysics Data System (ADS)

Sharma, Amit Kumar; Chandra, Sulekh

2011-10-01

Complexes of the type [M(L)X 2], where M = Co(II), Ni(II) and Cu(II), have been synthesized with novel NO-donor Schiff's base ligand, 1,4-diformylpiperazine bis(4-imino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one) which is obtained by the acid catalyzed condensation of 1,4-diformylpiperazine with 4-aminoantipyrine. The elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV, NMR, mass and EPR studies of the compounds led to the conclusion that the ligand acts as tetradentate chelate. The Schiff's base ligand forms hexacoordinated complexes having octahedral geometry for Ni(II) and tetragonal geometry for Co(II) and Cu(II) complexes. The mycological studies of the compounds were examined against the several opportunistic pathogens, i.e., Alternaria brassicae, Aspergillus niger and Fusarium oxysporum. The Cu(II) complexes were found to have most fungicidal behavior.

40 CFR Table II-1 to Subpart II of... - Emission Factors

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Emission Factors II Table II-1 to Subpart II of Part 98 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt. 98, Subpt. II, Table II-1...

40 CFR Table II-1 to Subpart II of... - Emission Factors

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Emission Factors II Table II-1 to Subpart II of Part 98 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt. 98, Subpt. II, Table II-1...

Multi-metals column adsorption of lead(II), cadmium(II) and manganese(II) onto natural bentonite clay.

PubMed

Alexander, Jock Asanja; Surajudeen, Abdulsalam; Aliyu, El-Nafaty Usman; Omeiza, Aroke Umar; Zaini, Muhammad Abbas Ahmad

2017-10-01

The present work was aimed at evaluating the multi-metals column adsorption of lead(II), cadmium(II) and manganese(II) ions onto natural bentonite. The bentonite clay adsorbent was characterized for physical and chemical properties using X-ray diffraction, X-ray fluorescence, Brunauer-Emmett-Teller surface area and cation exchange capacity. The column performance was evaluated using adsorbent bed height of 5.0 cm, with varying influent concentrations (10 mg/L and 50 mg/L) and flow rates (1.4 mL/min and 2.4 mL/min). The result shows that the breakthrough time for all metal ions ranged from 50 to 480 minutes. The maximum adsorption capacity was obtained at initial concentration of 10 mg/L and flow rate of 1.4 mL/min, with 2.22 mg/g of lead(II), 1.71 mg/g of cadmium(II) and 0.37 mg/g of manganese(II). The order of metal ions removal by natural bentonite is lead(II) > cadmium(II) > manganese(II). The sorption performance and the dynamic behaviour of the column were predicted using Adams-Bohart, Thomas, and Yoon-Nelson models. The linear regression analysis demonstrated that the Thomas and Yoon-Nelson models fitted well with the column adsorption data for all metal ions. The natural bentonite was effective for the treatment of wastewater laden with multi-metals, and the process parameters obtained from this work can be used at the industrial scale.

Homo- and Heterometallic Bis(Pentafluorobenzoyl)Methanide Complexes of Copper(II) and Cobalt(II)

NASA Astrophysics Data System (ADS)

Crowder, Janell M.

beta-Diketones are well known to form metal complexes with practically every known metal and metalloid. Metal complexes of fluorinated beta-diketones generally exhibit increased volatility and thermal stability compared to the non-fluorinated analogues, and thus are used extensively in various chemical vapor deposition (CVD) processes for the deposition of metal, simple or mixed metal oxides, and fluorine-doped metal oxide thin films. Furthermore, the electron-withdrawing nature of the fluorinated ligand enhances the Lewis acidity of a coordinatively unsaturated metal center which facilitates additional coordination reactions. The physical and structural properties of fluorinated beta-diketonate complexes are discussed in Chapter 1 and a few key application examples are given. The focus of this work is the synthesis and single crystal X-ray structural characterization of unsolvated and coordinatively unsaturated metal complexes of bis(pentafluorobenzoyl)- methanide (L, C6F5COCHCOC 6F5-). In Chapter 2, we present the preparation and isolation of the unsolvated complex [Cu(L)2] in pure crystalline form for the first time. We subsequently investigated the reaction of unsolvated [Cu(L)2] with sodium hexafluoroacetylacetonate [Na(hfac)] in a solvent-free environment. This reaction allowed the isolation of the first heterometallic Na-Cu diketonate [Na2Cu2(L) 4(hfac)2] structurally characterized by single crystal X-ray crystallography. Thermal decomposition of [Na2Cu2(L) 4(hfac)2] was investigated for its potential application in MOCVD processes. In the final chapter, we present the first exploration of the anhydrous synthesis of Co(II) complexed with bis(pentafluorobenzoyl)methanide in order to produce a complex without ligated water. Single crystal X-ray crystallographic investigations revealed the isolation of the ethanol adduct, [Co2(L)4(C2H5OH)2], and following the removal of ethanol, a 1,4-dioxane adduct, [{Co 2(L)4}2(C4H8O2)]. In this work, we have provided the

Fe (III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of schiff bases based-on glycine and phenylalanine: Synthesis, magnetic/thermal properties and antimicrobial activity

NASA Astrophysics Data System (ADS)

Sevgi, Fatih; Bagkesici, Ugur; Kursunlu, Ahmed Nuri; Guler, Ersin

2018-02-01

Zinc (II), copper (II), nickel (II), cobalt (II) and iron (III) complexes of Schiff bases (LG, LP) derived from 2-hydroxynaphthaldehyde with glycine and phenylalanine were reported and characterized by 1H NMR, 13C NMR, elemental analyses, melting point, FT-IR, magnetic susceptibility and thermal analyses (TGA). TGA data show that iron and cobalt include to the coordinated water and metal:ligand ratio is 1:2 while the complex stoichiometry for Ni (II), Cu (II) and Zn (II) complexes is 1:1. As expected, Ni (II) and Zn (II) complexes are diamagnetic; Cu (II), Co (II) and Fe (III) complexes are paramagnetic character due to a strong ligand of LG and LP. The LG, LP and their metal complexes were screened for their antimicrobial activities against five Gram-positive (Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Streptococcus mutans and Enterococcus faecalis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and one fungi (Candida albicans) by using broth microdilution techniques. The activity data show that ligands and their metal complexes exhibited moderate to good activity against Gram-positive bacteria and fungi.

Synthesis, characterization and biological activity of complexes of 2-hydroxy-3,5-dimethylacetophenoneoxime (HDMAOX) with copper(II), cobalt(II), nickel(II) and palladium(II)

NASA Astrophysics Data System (ADS)

Singh, Bibhesh K.; Jetley, Umesh K.; Sharma, Rakesh K.; Garg, Bhagwan S.

2007-09-01

A new series of complexes of 2-hydroxy-3,5-dimethyl acetophenone oxime (HDMAOX) with Cu(II), Co(II), Ni(II) and Pd(II) have been prepared and characterized by different physical techniques. Infrared spectra of the complexes indicate deprotonation and coordination of the phenolic OH. It also confirms that nitrogen atom of the oximino group contributes to the complexation. Electronic spectra and magnetic susceptibility measurements reveal square planar geometry for Cu(II), Ni(II) and Pd(II) complexes and tetrahedral geometry for Co(II) complex. The elemental analyses and mass spectral data have justified the ML 2 composition of complexes. Kinetic and thermodynamic parameters were computed from the thermal decomposition data using Coats and Redfern method. The geometry of the metal complexes has been optimized with the help of molecular modeling. The free ligand (HDMAOX) and its metal complexes have been tested in vitro against Alternarie alternate, Aspergillus flavus, Aspergillus nidulans and Aspergillus niger fungi and Streptococcus, Staph, Staphylococcus and Escherchia coli bacteria in order to assess their antimicrobial potential. The results indicate that the ligand and its metal complexes possess antimicrobial properties.

Synthesis, characterization and biological activity of complexes of 2-hydroxy-3,5-dimethylacetophenoneoxime (HDMAOX) with copper(II), cobalt(II), nickel(II) and palladium(II).

PubMed

Singh, Bibhesh K; Jetley, Umesh K; Sharma, Rakesh K; Garg, Bhagwan S

2007-09-01

A new series of complexes of 2-hydroxy-3,5-dimethyl acetophenone oxime (HDMAOX) with Cu(II), Co(II), Ni(II) and Pd(II) have been prepared and characterized by different physical techniques. Infrared spectra of the complexes indicate deprotonation and coordination of the phenolic OH. It also confirms that nitrogen atom of the oximino group contributes to the complexation. Electronic spectra and magnetic susceptibility measurements reveal square planar geometry for Cu(II), Ni(II) and Pd(II) complexes and tetrahedral geometry for Co(II) complex. The elemental analyses and mass spectral data have justified the ML(2) composition of complexes. Kinetic and thermodynamic parameters were computed from the thermal decomposition data using Coats and Redfern method. The geometry of the metal complexes has been optimized with the help of molecular modeling. The free ligand (HDMAOX) and its metal complexes have been tested in vitro against Alternarie alternate, Aspergillus flavus, Aspergillus nidulans and Aspergillus niger fungi and Streptococcus, Staph, Staphylococcus and Escherchia coli bacteria in order to assess their antimicrobial potential. The results indicate that the ligand and its metal complexes possess antimicrobial properties.

Solar Type II Radio Bursts and IP Type II Events

NASA Technical Reports Server (NTRS)

Cane, H. V.; Erickson, W. C.

2005-01-01

We have examined radio data from the WAVES experiment on the Wind spacecraft in conjunction with ground-based data in order to investigate the relationship between the shocks responsible for metric type II radio bursts and the shocks in front of coronal mass ejections (CMEs). The bow shocks of fast, large CMEs are strong interplanetary (IP) shocks, and the associated radio emissions often consist of single broad bands starting below approx. 4 MHz; such emissions were previously called IP type II events. In contrast, metric type II bursts are usually narrowbanded and display two harmonically related bands. In addition to displaying complete dynamic spectra for a number of events, we also analyze the 135 WAVES 1 - 14 MHz slow-drift time periods in 2001-2003. We find that most of the periods contain multiple phenomena, which we divide into three groups: metric type II extensions, IP type II events, and blobs and bands. About half of the WAVES listings include probable extensions of metric type II radio bursts, but in more than half of these events, there were also other slow-drift features. In the 3 yr study period, there were 31 IP type II events; these were associated with the very fastest CMEs. The most common form of activity in the WAVES events, blobs and bands in the frequency range between 1 and 8 MHz, fall below an envelope consistent with the early signatures of an IP type II event. However, most of this activity lasts only a few tens of minutes, whereas IP type II events last for many hours. In this study we find many examples in the radio data of two shock-like phenomena with different characteristics that occur simultaneously in the metric and decametric/hectometric bands, and no clear example of a metric type II burst that extends continuously down in frequency to become an IP type II event. The simplest interpretation is that metric type II bursts, unlike IP type II events, are not caused by shocks driven in front of CMEs.

Phosphate effects on copper(II) and lead(II) sorption to ferrihydrite

NASA Astrophysics Data System (ADS)

Tiberg, Charlotta; Sjöstedt, Carin; Persson, Ingmar; Gustafsson, Jon Petter

2013-11-01

Transport of lead(II) and copper(II) ions in soil is affected by the soil phosphorus status. Part of the explanation may be that phosphate increases the adsorption of copper(II) and lead(II) to iron (hydr)oxides in soil, but the details of these interactions are poorly known. Knowledge about such mechanisms is important, for example, in risk assessments of contaminated sites and development of remediation methods. We used a combination of batch experiments, extended X-ray absorption fine structure (EXAFS) spectroscopy and surface complexation modeling with the three-plane CD-MUSIC model to study the effect of phosphate on sorption of copper(II) and lead(II) to ferrihydrite. The aim was to identify the surface complexes formed and to derive constants for the surface complexation reactions. In the batch experiments phosphate greatly enhanced the adsorption of copper(II) and lead(II) to ferrihydrite at pH < 6. The largest effects were seen for lead(II).

Sodium butyrate suppresses angiotensin II-induced hypertension by inhibition of renal (pro)renin receptor and intrarenal renin-angiotensin system.

PubMed

Wang, Lei; Zhu, Qing; Lu, Aihua; Liu, Xiaofen; Zhang, Linlin; Xu, Chuanming; Liu, Xiyang; Li, Haobo; Yang, Tianxin

2017-09-01

Butyrate, a short-chain fatty acid, is the end product of the fermentation of complex carbohydrates by the gut microbiota. Recently, sodium butyrate (NaBu) has been found to play a protective role in a number of chronic diseases. However, it is still unclear whether NaBu has a therapeutic potential in hypertension. The present study was aimed to investigate the role of NaBu in angiotensin II (Ang II)-induced hypertension and to further explore the underlying mechanism. Ang II was infused into uninephrectomized Sprague-Dawley rats with or without intramedullary infusion of NaBu for 14 days. Mean arterial blood pressure was recorded by the telemetry system. Renal tissues, serum samples, and 24-h urine samples were collected to examine renal injury and the regulation of the (pro)renin receptor (PRR) and renin. Intramedullary infusion of NaBu in Sprague-Dawley rats lowered the Ang II-induced mean arterial pressure from 129 ± 6 mmHg to 108 ± 4 mmHg (P < 0.01). This corresponded with an improvement in Ang II-induced renal injury, including urinary albumin, glomerulosclerosis, and renal fibrosis, as well as the expression of inflammatory mediators tumor necrosis factor α, interleukin 6. The renal expression of PRR, angiotensinogen, angiotensin I-converting enzyme and the urinary excretion of soluble PRR, renin, and angiotensinogen were all increased by Ang II infusion but decreased by NaBu treatment. In cultured innermedullary collecting duct cells, NaBu treatment attenuated Ang II-induced expression of PRR and renin. These results demonstrate that NaBu exerts an antihypertensive action, likely by suppressing the PRR-mediated intrarenal renin-angiotensin system.

Porous cellulosic adsorbent for the removal of Cd (II), Pb(II) and Cu(II) ions from aqueous media

NASA Astrophysics Data System (ADS)

Barsbay, Murat; Kavaklı, Pınar Akkaş; Tilki, Serhad; Kavaklı, Cengiz; Güven, Olgun

2018-01-01

The main objective of this work is to prepare a renewable cellulosic adsorbent by γ-initiated grafting of poly(glycidyl methacrylate) (PGMA) from cellulose substrate and subsequent modification of PGMA with chelating species, iminodiacetic acid (IDA), for Cd (II), Pb(II) and Cu(II) removal from aqueous media. Modification of PGMA grafted cellulose with IDA in aqueous solution under mild conditions has proceeded efficiently to yield a natural-based and effective porous adsorbent with well-defined properties as provided by the controlled polymerization technique, namely RAFT, applied during the radiation-induced graft copolymerization step and with sufficient degree of IDA immobilization as confirmed by XPS, FTIR, contact angle measurements and elemental analysis. In order to examine the Cd (II), Pb(II) and Cu(II) removing performance of the resulting adsorbent, batch experiments were carried out by ICP-MS. The adsorption capacities were determined as 53.4 mg Cd(II)/g polymer, 52.0 mg Pb(II)/g polymer and 69.6 mg Cu(II)/g polymer at initial feed concentration of 250 ppm, showing the promising potential of the natural-based adsorbent to steadily and efficiently chemisorb toxic metal ions.

Pecan nutshell as biosorbent to remove Cu(II), Mn(II) and Pb(II) from aqueous solutions.

PubMed

Vaghetti, Julio C P; Lima, Eder C; Royer, Betina; da Cunha, Bruna M; Cardoso, Natali F; Brasil, Jorge L; Dias, Silvio L P

2009-02-15

In the present study we reported for the first time the feasibility of pecan nutshell (PNS, Carya illinoensis) as an alternative biosorbent to remove Cu(II), Mn(II) and Pb(II) metallic ions from aqueous solutions. The ability of PNS to remove the metallic ions was investigated by using batch biosorption procedure. The effects such as, pH, biosorbent dosage on the adsorption capacities of PNS were studied. Four kinetic models were tested, being the adsorption kinetics better fitted to fractionary-order kinetic model. Besides that, the kinetic data were also fitted to intra-particle diffusion model, presenting three linear regions, indicating that the kinetics of adsorption should follow multiple sorption rates. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Redlich-Peterson isotherm models. Taking into account a statistical error function, the data were best fitted to Sips isotherm model. The maximum biosorption capacities of PNS were 1.35, 1.78 and 0.946mmolg(-1) for Cu(II), Mn(II) and Pb(II), respectively.

Nucleoside-2',3'/3',5'-bis(thio)phosphate antioxidants are also capable of disassembly of amyloid beta42-Zn(ii)/Cu(ii) aggregates via Zn(ii)/Cu(ii)-chelation.

PubMed

Hevroni, Bosmat Levi; Major, Dan Thomas; Dixit, Mudit; Mhashal, Anil Ranu; Das, Susanta; Fischer, Bilha

2016-05-18

Currently, there is an urgent need for biocompatible metal-ion chelators capable of antioxidant activity and disassembly of amyloid beta (Aβ)-aggregates as potential therapeutics for Alzheimer's disease (AD). We recently demonstrated the promising antioxidant activity of adenine/guanine 2',3' or 3',5'-bis(thio)phosphate analogues, 2'-dA/G3'5'PO/S and A2'3'PO/S, and their affinity to Zn(ii)-ions. These findings encouraged us to evaluate them as agents for the dissolution of Aβ42-Zn(ii)/Cu(ii) aggregates. Specifically, we explored their ability to bind Cu(ii)/Zn(ii)-ions, the geometry and stoichiometry of these complexes, Cu(ii)/Zn(ii)-binding-sites and binding mode, and the ability of these analogues to dissolve Aβ42-Zn(ii)/Cu(ii) aggregates, as well as their effect on the secondary structure of those aggregates. Finally, we identified the most promising agents for dissolution of Aβ42-Zn(ii)/Cu(ii) aggregates. Specifically, we observed the formation of a 1 : 1 complex between 2'-dG3'5'PO and Cu(ii), involving O4 ligands. Zn(ii) was coordinated by both thiophosphate groups of 2'-dA3'5'PS and A2'3'PS involving O2S2 ligands in a 1 : 1 stoichiometry. A2'3'PS dissolves Aβ42-Zn(ii) and Aβ42-Cu(ii) aggregates as effectively as, and 2.5-fold more effectively than EDTA, respectively. Furthermore, 2'-dG3'5'PS and A2'3'PS reverted the Aβ42-M(ii) structure, back to that of the free Aβ42. Finally, cryo-TEM and TEM images confirmed the disassembly of Aβ42 and Aβ42-M(ii) aggregates by A2'3'PS. Hence, 2'-dG3'5'PS and A2'3'PS may serve as promising scaffolds for new AD therapeutics, acting as both effective antioxidants and agents for solubilization of Aβ42-Cu(ii)/Zn(ii) aggregates.

Self-assembled decanuclear Na(I)2Mn(II)4Mn(III)4 complexes: from discrete clusters to 1-D and 2-D structures, with the Mn(II)4Mn(III)4 unit displaying a large spin ground state and probable SMM behaviour.

PubMed

Langley, Stuart K; Chilton, Nicholas F; Moubaraki, Boujemaa; Murray, Keith S

2011-12-07

The synthesis, magnetic characterization and X-ray crystal structures are reported for five new manganese compounds, [Mn(III)(teaH(2))(sal)]·(1/2)H(2)O (1), [Na(I)(2)Mn(II)(4)Mn(III)(4)(teaH)(6)(sal)(4)(N(3))(2)(MeOH)(4)]·6MeOH (2), [Na(I)(2)Mn(II)(4)Mn(III)(4)(teaH)(6)(sal)(4)(N(3))(2)(MeOH)(2)](n)·7MeOH (3), [Na(I)(2)Mn(II)(4)Mn(III)(4)(teaH)(6)(sal)(4)(N(3))(2)(MeOH)(2)](n)·2MeOH·Et(2)O (4) and [K(I)(2)Mn(II)(4)Mn(III)(4)(teaH)(6)(sal)(4)(N(3))(2)(H(2)O)(2)](n)·5MeOH (5). Complex 1 is a mononuclear compound, formed via the reaction of Mn(NO(3))(2)·4H(2)O, triethanolamine (teaH(3)) and salicylic acid (salH(2)) in a basic methanolic solution. Compound 2 is a mixed-valent hetero-metallic cluster made up of a Mn(8)Na(2) decanuclear core and is formed via the reaction of sodium azide (NaN(3)) with 1. Compounds 3-5 are isolated as 1- or 2-D coordination polymers, each containing the decanuclear Mn(8)M(2) (M = Na(+) or K(+)) core building block as the repeating unit. Compound 3 is isolated when 1 is reacted with NaN(3) over a very short reaction time and forms a 1-D coordination polymer. Each unit displays inter-cluster bridges via the O-atoms of teaH(2-) ligands bonding to the sodium ions of an adjacent cluster. Increasing the reaction time appears to drive the formation of 4 which forms 2-D polymeric sheets and is a packing polymorph of 3. The addition of KMnO(4) and NaN(3) to 1 resulted in compound 5, which also forms a 1-D coordination polymer of the decanuclear core unit. The 1-D chains are now linked via inter-cluster potassium and salicylate bridges. Solid state DC susceptibility measurements were performed on compounds 1-5. The data for 1 are as expected for an S = 2 Mn(III) ion, with the isothermal M vs. H data being fitted by matrix diagonalization methods to give values of g and the axial (D) and rhombic (E) zero field splitting parameters of 2.02, -2.70 cm(-1) and 0.36 cm(-1) respectively. The data for 2-5, each with an identical Mn(II)(4)Mn(III)(4

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.

Synthesis and Ligand Non-Innocence of Thiolate-Ligated (N4S) Iron(II) and Nickel(II) Bis(imino)pyridine Complexes

PubMed Central

Widger, Leland R.; Jiang, Yunbo; Siegler, Maxime; Kumar, Devesh; Latifi, Reza; de Visser, Sam P.; Jameson, Guy N.L.; Goldberg, David P.

2013-01-01

The known iron(II) complex [FeII(LN3S)(OTf)] (1) was used as starting material to prepare the new biomimetic (N4S(thiolate)) iron(II) complexes [FeII(LN3S)(py)](OTf) (2) and [FeII(LN3S)(DMAP)](OTf) (3), where LN3S is a tetradentate bis(imino)pyridine (BIP) derivative with a covalently tethered phenylthiolate donor. These complexes were characterized by X-ray crystallography, UV-vis, 1H NMR, and Mössbauer spectroscopy, as well as electrochemistry. A nickel(II) analogue, [NiII(LN3S)](BF4) (5), was also synthesized and characterized by structural and spectroscopic methods. Cyclic voltammetric studies showed 1 – 3 and 5 undergo a single reduction process with E1/2 between −0.9 to −1.2 V versus Fc+/Fc. Treatment of 3 with 0.5% Na/Hg amalgam gave the mono-reduced complex [Fe(LN3S)(DMAP)]0 (4), which was characterized by X-ray crystallography, UV-vis, EPR (g = [2.155, 2.057, 2.038]) and Mössbauer (δ = 0.33 mm s−1; ΔEQ = 2.04 mm s−1) spectroscopies. Computational methods (DFT) were employed to model complexes 3 – 5. The combined experimental and computational studies show that 1 – 3 are 5-coordinate, high-spin (S = 2) FeII complexes, whereas 4 is best described as a 5-coordinate, intermediate-spin (S = 1) FeII complex antiferromagnetically coupled to a ligand radical. This unique electronic configuration leads to an overall doublet spin (Stotal = ½) ground state. Complexes 2 and 3 are shown to react with O2 to give S-oxygenated products, as previously reported for 1. In contrast, the mono-reduced 4 appears to react with O2 to give a mixture of S- and Fe-oxygenates. The nickel(II) complex 5 does not react with O2, and even when the mono-reduced nickel complex is produced, it appears to undergo only outer-sphere oxidation with O2. PMID:23992096

Synthesis, characterization, DFT calculations and biological studies of Mn(II), Fe(II), Co(II) and Cd(II) complexes based on a tetradentate ONNO donor Schiff base ligand

NASA Astrophysics Data System (ADS)

Abdel-Rahman, Laila H.; Ismail, Nabawia M.; Ismael, Mohamed; Abu-Dief, Ahmed M.; Ahmed, Ebtehal Abdel-Hameed

2017-04-01

This study highlights synthesis and characterization of a tetradentate ONNO Schiff base ligand namely (1, 1‧- (pyridine-2, 3-dimethyliminomethyl) naphthalene-2, 2‧-diol) and hereafter denotes as "HNDAP″ and selected metal complexes including Mn(II), Fe(II), Co(II) and Cd(II) as a central metal. HNDAP was synthesized from 1:2 M ratio condensation of 2, 3-diaminopyridine and 2- hydroxy-1-naphthaldhyde, respectively. The stoichiometric ratios of the prepared complexes were estimated using complementary techniques such as; elemental analyses (-C, H, N), FT-IR, magnetic measurements and molar conductivity. Furthermore, their physicochemical studies were carried out using thermal TGA, DTA and kinetic-thermodynamic studies along with DFT calculations. The results of elemental analyses showed that these complexes are present in a 1:1 metal-to- ligand molar ratio. Moreover, the magnetic susceptibilities values at room temperature revealed that Mn(II), Fe(II) and Co(II) complexes are paramagnetic in nature and have an octahedral (Oh) geometry. In contrast, Cd(II) is diamagnetic and stabilizes in square planar sites. The molar conductivity measurements indicated that all complexes are nonelectrolytes in dimethyl formamide. Spectral data suggested that the ligand is as tetradentate and coordinated with Co(II) ion through two phenolic OH and two azomethine nitrogen. However, for Mn(II), Fe(II) and Cd(II) complexes, the coordination occurred through two phenolic oxygen and two azomethine nitrogen with deprotonation of OH groups. The proposed chemical structures have been validated by quantum mechanics calculations. Antimicrobial activities of both the HNDAP Schiff base ligand and its metal complexes were tested against strains of Gram (-ve) E. coli and Gram (+ve) B. subtilis and S. aureus bacteria and C. albicans, A. flavus and T. rubrum fungi. All the prepared compounds showed good results of inhibition against the selected pathogenic microorganisms. The investigated

A comparative gene analysis with rice identified orthologous group II HKT genes and their association with Na(+) concentration in bread wheat.

PubMed

Ariyarathna, H A Chandima K; Oldach, Klaus H; Francki, Michael G

2016-01-19

Although the HKT transporter genes ascertain some of the key determinants of crop salt tolerance mechanisms, the diversity and functional role of group II HKT genes are not clearly understood in bread wheat. The advanced knowledge on rice HKT and whole genome sequence was, therefore, used in comparative gene analysis to identify orthologous wheat group II HKT genes and their role in trait variation under different saline environments. The four group II HKTs in rice identified two orthologous gene families from bread wheat, including the known TaHKT2;1 gene family and a new distinctly different gene family designated as TaHKT2;2. A single copy of TaHKT2;2 was found on each homeologous chromosome arm 7AL, 7BL and 7DL and each gene was expressed in leaf blade, sheath and root tissues under non-stressed and at 200 mM salt stressed conditions. The proteins encoded by genes of the TaHKT2;2 family revealed more than 93% amino acid sequence identity but ≤52% amino acid identity compared to the proteins encoded by TaHKT2;1 family. Specifically, variations in known critical domains predicted functional differences between the two protein families. Similar to orthologous rice genes on chromosome 6L, TaHKT2;1 and TaHKT2;2 genes were located approximately 3 kb apart on wheat chromosomes 7AL, 7BL and 7DL, forming a static syntenic block in the two species. The chromosomal region on 7AL containing TaHKT2;1 7AL-1 co-located with QTL for shoot Na(+) concentration and yield in some saline environments. The differences in copy number, genes sequences and encoded proteins between TaHKT2;2 homeologous genes and other group II HKT gene families within and across species likely reflect functional diversity for ion selectivity and transport in plants. Evidence indicated that neither TaHKT2;2 nor TaHKT2;1 were associated with primary root Na(+) uptake but TaHKT2;1 may be associated with trait variation for Na(+) exclusion and yield in some but not all saline environments.

Spectroscopic (FT-IR, FT-Raman, 1H, 13C NMR, UV/VIS), thermogravimetric and antimicrobial studies of Ca(II), Mn(II), Cu(II), Zn(II) and Cd(II) complexes of ferulic acid

NASA Astrophysics Data System (ADS)

Kalinowska, M.; Piekut, J.; Bruss, A.; Follet, C.; Sienkiewicz-Gromiuk, J.; Świsłocka, R.; Rzączyńska, Z.; Lewandowski, W.

2014-03-01

The molecular structure of Mn(II), Cu(II), Zn(II), Cd(II) and Ca(II) ferulates (4-hydroxy-3-methoxycinnamates) was studied. The selected metal ferulates were synthesized. Their composition was established by means of elementary and thermogravimetric analysis. The following spectroscopic methods were used: infrared (FT-IR), Raman (FT-Raman), nuclear magnetic resonance (13C, 1H NMR) and ultraviolet-visible (UV/VIS). On the basis of obtained results the electronic charge distribution in studied metal complexes in comparison with ferulic acid molecule was discussed. The microbiological study of ferulic acid and ferulates toward Escherichia coli, Bacillus subtilis, Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus and Proteus vulgaris was done.

Competitive adsorption of Pb(II), Cu(II), and Zn(II) ions onto hydroxyapatite-biochar nanocomposite in aqueous solutions

NASA Astrophysics Data System (ADS)

Wang, Yu-Ying; Liu, Yu-Xue; Lu, Hao-Hao; Yang, Rui-Qin; Yang, Sheng-Mao

2018-05-01

A hydroxyapatite-biochar nanocomposite (HAP-BC) was successfully fabricated and its physicochemical properties characterized. The analyses showed that HAP nanoparticles were successfully loaded on the biochar surface. The adsorption of Pb(II), Cu(II), and Zn(II) by HAP-BC was systematically studied in single and ternary metal systems. The results demonstrated that pH affects the adsorption of heavy metals onto HAP-BC. Regarding the adsorption kinetics, the pseudo-second-order model showed the best fit for all three heavy metal ions on HAP-BC. In both single and ternary metal ion systems, the adsorption isotherm of Pb(II) by HAP-BC followed Langmuir model, while those of Cu(II) and Zn(II) fitted well with Freundlich model. The maximum adsorption capacity for each tested metal by HAP-BC was higher than that of pristine rice straw biochar (especially for Pb(II)) or those of other reported adsorbents. Therefore, HAP-BC could explore as a new material for future application in heavy metal removal.

Biosorption characteristics of copper (II), chromium (III), nickel (II), and lead (II) from aqueous solutions by Chara sp. and Cladophora sp.

PubMed

Elmaci, Ayşe; Yonar, Taner; Ozengin, Nihan

2007-09-01

The aim of this research was to expose individual removals of copper, chromium, nickel, and lead from aqueous solutions via biosorption using nonliving algae species, Chara sp. and Cladophora sp. Optimum pH values for biosorption of copper (II), chromium (III), nickel (II), and lead (II) from aqueous solutions were determined to be 6, 7, 7, and 3 for Cladophora sp. and 5, 3, 5, and 4 for Chara sp. respectively. Maximum adsorption capacities of Chara sp. [10.54 for chromium (III) and 61.72 for lead (II)] and Cladophora sp. [6.59 for chromium (III) and 16.75 and 23.25 for lead (II)] for chromium (III) and lead (II) are similar. On the other hand, copper (II) and nickel (II) biosorption capacity of Cladophora sp. [14.28 for copper (II) and 16.75 for nickel (II)] is greater than Chara sp. [6.506 for copper (II) and 11.76 for nickel (II)]. Significantly high correlation coefficients indicated for the Langmuir adsorption isotherm models can be used to describe the equilibrium behavior of copper, chromium, nickel, and lead adsorption onto Cladophora sp. and Chara sp.

Precursor routes to quaternary intermetallics: Synthesis, crystal structure, and physical properties of clathrate-II Cs8Na16Al24Si112

NASA Astrophysics Data System (ADS)

Wei, Kaya; Dong, Yongkwan; Nolas, George S.

2016-05-01

A new quaternary clathrate-II composition, Cs8Na16Al24Si112, was synthesized by kinetically controlled thermal decomposition (KCTD) employing both NaSi and NaAlSi as the precursors and CsCl as a reactive flux. The crystal structure and composition of Cs8Na16Al24Si112 were investigated using both Rietveld refinement and elemental analysis, and the temperature dependent transport properties were investigated. Our results indicate that KCTD with multiple precursors is an effective method for the synthesis of multinary inorganic phases that are not easily accessible by traditional solid-state synthesis or crystal growth techniques.

Removal of Pb(II), Cd(II), Cu(II), and Zn(II) by hematite nanoparticles: effect of sorbent concentration, pH, temperature, and exhaustion.

PubMed

Shipley, Heather J; Engates, Karen E; Grover, Valerie A

2013-03-01

Nanoparticles offer the potential to improve environmental treatment technologies due to their unique properties. Adsorption of metal ions (Pb(II), Cd(II), Cu(II), Zn(II)) to nanohematite was examined as a function of sorbent concentration, pH, temperature, and exhaustion. Adsorption experiments were conducted with 0.05, 0.1, and 0.5 g/L nanoparticles in a pH 8 solution and in spiked San Antonio tap water. The adsorption data showed the ability of nanohematite to remove Pb, Cd, Cu, and Zn species from solution with adsorption increasing as the nanoparticle concentration increased. At 0.5 g/L nanohematite, 100 % Pb species adsorbed, 94 % Cd species adsorbed, 89 % Cu species adsorbed and 100 % Zn species adsorbed. Adsorption kinetics for all metals tested was described by a pseudo second-order rate equation with lead having the fastest rate of adsorption. The effect of temperature on adsorption showed that Pb(II), Cu(II), and Cd(II) underwent an endothermic reaction, while Zn(II) underwent an exothermic reaction. The nanoparticles were able to simultaneously remove multiple metals species (Zn, Cd, Pb, and Cu) from both a pH 8 solution and spiked San Antonio tap water. Exhaustion experiments showed that at pH 8, exhaustion did not occur for the nanoparticles but adsorption does decrease for Cd, Cu, and Zn species but not Pb species. The strong adsorption coupled with the ability to simultaneously remove multiple metal ions offers a potential remediation method for the removal of metals from water.

New Rh 2 (II,II) Architecture for the Catalytic Reduction of H +

DOE PAGES

White, Travis A.; Witt, Suzanne E.; Li, Zhanyong; ...

2015-09-25

Formamidinate-bridged Rh 2 II,II complexes containing diimine ligands of the formula cis-[Rh 2 II,II(μ-DTolF) 2(NN) 2] 2+ (Rh 2-NN 2), where DTolF = p-ditolylformamidinate and NN = dppn (benzo[i]dipyrido[3,2-a:2',3'-h]quinoxaline), dppz (dipyrido[3,2-a:2',3'-c]phenazine), and phen (1,10-phenanthroline), electrocatalytically reduce H + to H 2 in DMF solutions containing CH 3COOH at a glassy carbon electrode. Cathodic scans in the absence of acid display a Rh III,II/II,II reduction at -0.90 V vs Fc +/Fc followed by NN 0/– reduction at -1.13, -1.36, and -1.65 V for Rh 2-dppn 2, Rh 2-dppz 2, and Rh 2-phen 2, respectively. Upon the addition of acid, Rh 2-dppnmore » 2 and Rh 2-dppz 2 undergo reduction–protonation–reduction at each pyrazine-containing NN ligand prior to the Rh 2 II,II/II,I reduction. The Rh 2 II,I species is thus protonated at one of the metal centers, resulting in the formation of the corresponding Rh 2 II,III-hydride. In the case of Rh 2-phen 2, the reduction of the phen ligand is followed by intramolecular electron transfer to the Rh 2 II,II core in the presence of protons to form a Rh 2 II,III-hydride species. Further reduction and protonation at the Rh 2 core for all three complexes rapidly catalyzes H 2 formation with varied calculated turnover frequencies (TOF) and overpotential values (η): 2.6 × 10 4 s –1 and 0.56 V for Rh 2-dppn, 2.8 × 10 4 s –1 and 0.50 V for Rh 2-dppz 2, and 5.9 × 10 4 s –1 and 0.64 V for Rh 2-phen 2. Bulk electrolysis confirmed H 2 formation, and further CH 3COOH addition regenerates H 2 production, attesting to the robust nature of the architecture. The cis-[Rh 2 II,II(μ-DTolF) 2(NN) 2] 2+ architecture benefits by combining electron-rich formamidinate bridges, a redox-active Rh 2 II,II core, and electron-accepting NN diimine ligands to allow for the electrocatalysis of H + substrate to H 2 fuel.« less

Syntheses, structures, and properties of trinuclear complexes [M(bpca)(2)(M'(hfac)(2))(2)], constructed with the complexed bridging ligand [M(bpca)(2)] [M, M' = Ni(II), Mn(II); Cu(II), Mn(II); Fe(II), Mn(II); Ni(II), Fe(II); and Fe(II), Fe(II); Hbpca = Bis(2-pyridylcarbonyl)amine, Hhfac = Hexafluoroacetylacetone].

PubMed

Kamiyama, Asako; Noguchi, Tomoko; Kajiwara, Takashi; Ito, Tasuku

2002-02-11

Five trinuclear complexes [M(bpca)(2)(M'(hfac)(2))(2)] (where MM'(2) = NiMn(2), CuMn(2), FeMn(2), NiFe(2), and FeFe(2); Hbpca = bis(2-pyridylcarbonyl)amine; and Hhfac = hexafluoroacetylacetone) were synthesized almost quantitatively by the reaction of [M(bpca)(2)] and [M'(hfac)(2)] in 1:2 molar ratio, and their structures and magnetic properties were investigated. Three complexes, with M' = Mn, crystallize in the same space group, Pna2(1), whereas two complexes, with M' = Fe, crystallize in P4(1), and complexes within each set are isostructural to one another. In all complexes, [M(bpca)(2)] acts as a bis-bidentate bridging ligand to form a linear trinuclear complex in which three metal ions are arranged in the manner M'-M-M'. The central metal ion is in a strong ligand field created by the N(6) donor set, and hence the Fe(II) in the [Fe(bpca)(2)] moiety is in a low-spin state. The terminal metal ions (M') are surrounded by O(6) donor sets with a moderate ligand field, which leads to the high-spin configuration of Fe(II). Three metal ions in all complexes are almost collinear, and metal-metal distances are ca. 5.5 A. The magnetic behavior of NiMn(2) and NiFe(2) shows a weak ferromagnetic interaction between the central Ni(II) ion and the terminal Mn(II) or Fe(II) ions. In these complexes, sigma-spin orbitals of the central Ni(II) ion and those of terminal metal ions have different symmetry about a 2-fold rotation axis through the Ni-N(amide)-M'(terminal) atoms, and this results in orthogonality between the neighboring sigma-spin orbitals and thus ferromagnetic interactions.

Novel lead(II) carboxylate-arsonate hybrids

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

Yi Feiyan; Song Junling; Zhao Na

2008-06-15

Hydrothermal reactions of lead(II) acetate with phenylarsonic acid (H{sub 2}L{sup 1}) (or 4-hydroxy-3-nitrophenylarsonic acid, H{sub 3}L{sup 2}) and 5-sulfoisophthalic acid monosodium salt (NaH{sub 2}SIP) (or 1,3,5-benzenetricarboxylic acid (H{sub 3}BTC)) as the second metal linkers afforded three novel mixed-ligand lead(II) carboxylate-arsonates, namely, Pb{sub 5}(SIP){sub 2}(L{sup 1}){sub 2}(H{sub 2}O) 1, Pb{sub 3}(SIP)(L{sup 2})(H{sub 2}O) 2 and Pb(H{sub 2}L{sup 2})(H{sub 2}BTC) 3. The structure of 1 features a complicated 3D network composed of 2D double layers of lead(II) sulfoisophthalate bridged by 1D chains of lead(II) arsonates along b-axis, forming large tunnels along b-axis which are occupied by phenyl rings of the arsonate ligands.more » In 2, the Pb(II) ions are bridged by {l_brace}L{sup 2}{r_brace}{sup 3-} anions into a 2D double layer whereas the interconnection of the Pb(II) ions via bridging and chelating SIP anions gave a 2D double layer. The cross-linkage of the above two building units leads to a complicated 3D network. In 3, the interconnection of the Pb(II) ions via bridging {l_brace}H{sub 2}L{sup 2}{r_brace}{sup -} and {l_brace}H{sub 2}BTC{r_brace}{sup -} anions leads to a 1D double chain down a-axis. These 1D chains are further interconnected via hydrogen bonds among non-coordination carboxylate groups and arsonate oxygens into a 3D supramolecular architecture. - Graphical abstract: Three novel mixed-ligand lead(II) carboxylate-arsonates, namely, Pb{sub 5}(SIP){sub 2}(L{sup 1}){sub 2}(H{sub 2}O) 1, Pb{sub 3}(SIP)(L{sup 2})(H{sub 2}O) 2 and Pb(H{sub 2}L{sup 2})(H{sub 2}BTC) 3 have been synthesized and structurally characterized. Compounds 1 and 2 feature complicated 3D network structures whereas compound 3 features 1D lead(II) carboxylate-arsonate chains that are further interlinked by strong hydrogen bonds into a 3D supramolecular assembly.« less

Structural alteration of hexagonal birnessite by aqueous Mn(II): Impacts on Ni(II) sorption

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

Lefkowitz, Joshua P.; Elzinga, Evert J.

We studied the impacts of aqueous Mn(II) (1 mM) on the sorption of Ni(II) (200 μM) by hexagonal birnessite (0.1 g L- 1) at pH 6.5 and 7.5 with batch experiments and XRD, ATR-FTIR and Ni K-edge EXAFS analyses. In the absence of Mn(II)aq, sorbed Ni(II) was coordinated predominantly as triple corner-sharing complexes at layer vacancies at both pH values. Introduction of Mn(II)aq into Ni(II)-birnessite suspensions at pH 6.5 caused Ni(II) desorption and led to the formation of edge-sharing Ni(II) complexes. This was attributed to competitive displacement of Ni(II) from layer vacancies by either Mn(II) or by Mn(III) formed throughmore » interfacial Mn(II)-Mn(IV) comproportionation, and/or incorporation of Ni(II) into the birnessite lattice promoted by Mn(II)-catalyzed recrystallization of the sorbent. Similar to Mn(II)aq, the presence of HEPES or MES caused the formation of edge-sharing Ni(II) sorption complexes in Ni(II)-birnessite suspensions, which was attributed to partial reduction of the sorbent by the buffers. At pH 7.5, interaction with aqueous Mn(II) caused reductive transformation of birnessite into secondary feitknechtite that incorporated Ni(II), enhancing removal of Ni(II) from solution. These results demonstrate that reductive alteration of phyllomanganates may significantly affect the speciation and solubility of Ni(II) in anoxic and suboxic environments.« less

Synthesis, spectroscopic characterization and biological activities of N4O2 Schiff base ligand and its metal complexes of Co(II), Ni(II), Cu(II) and Zn(II)

NASA Astrophysics Data System (ADS)

Al-Resayes, Saud I.; Shakir, Mohammad; Abbasi, Ambreen; Amin, Kr. Mohammad Yusuf; Lateef, Abdul

The Schiff base ligand, bis(indoline-2-one)triethylenetetramine (L) obtained from condensation of triethylenetetramine and isatin was used to synthesize the complexes of type, [ML]Cl2 [M = Co(II), Ni(II), Cu(II) and Zn(II)]. L was characterized on the basis of the results of elemental analysis, FT-IR, 1H and 13C NMR, mass spectroscopic studies. The stoichiometry, bonding and stereochemistries of complexes were ascertained on the basis of results of elemental analysis, magnetic susceptibility values, molar conductance and various spectroscopic studies. EPR, UV-vis and magnetic moments revealed an octahedral geometry for complexes. L and its Cu(II) and Zn(II) complexes were screened for their antibacterial activity. Analgesic activity of Cu(II) and Zn(II) complexes was also tested in rats by tail flick method. Both complexes were found to possess good antibacterial and moderate analgesic activity.

Elaboration of a Highly Porous RuII,II Analogue of HKUST-1.

PubMed

Zhang, Wenhua; Freitag, Kerstin; Wannapaiboon, Suttipong; Schneider, Christian; Epp, Konstantin; Kieslich, Gregor; Fischer, Roland A

2016-12-19

When the dinuclear Ru II,II precursor [Ru 2 (OOCCH 3 ) 4 ] is employed under redox-inert conditions, a Ru II,II analogue of HKUST-1 was successfully prepared and characterized as a phase-pure microcrystalline powder. X-ray absorption near-edge spectroscopy confirms the oxidation state of the Ru centers of the paddle-wheel nodes in the framework. The porosity of 1371 m 2 /mmol of Ru II,II -HKUST-1 exceeds that of the parent compound HKUST1 (1049 m 2 / mmol).

Dynamic adsorption of mixtures of Rhodamine B, Pb (II), Cu (II) and Zn(II) ions on composites chitosan-silica-polyethylene glycol membrane

NASA Astrophysics Data System (ADS)

Mahatmanti, F. W.; Rengga, W. D. P.; Kusumastuti, E.; Nuryono

2018-04-01

The adsorption of a solution mixture of Rhodamine B, Pb (II), Cu (II) and Zn(II) was studied using dynamic methods employing chitosan-silica-polyethylene glycol (Ch/Si/P) composite membrane as an adsorptive membrane. The composite Ch/Si/P membrane was prepared by mixing a chitosan-based membrane with silica isolated from rice husk ash (ASP) and polyethylene glycol (PEG) as a plasticizer. The resultant composite membrane was a stronger and more flexible membrane than the original chitosan-based membrane as indicated by the maximum percentage of elongation (20.5 %) and minimum Young’s Modulus (80.5 MPa). The composite membrane also showed increased mechanical and hydrophilic properties compared to the chitosan membranes. The membrane was used as adsorption membrane for Pb (II), Cu (II), Cd (II) ions and Rhodamine B dyes in a dynamic system where the permeation and selectivity were determined. The permeation of the components was observed to be in the following order: Rhodamine B > Cd (II) > Pb (II) > Cu (II) whereas the selectivity was shown to decrease the order of Cu (II) > Pb (II) > Cd (II) > Rhodamine B.

A Trinuclear Ni(II) Enediolate Complex: Synthesis, Characterization, and O2 Reactivity

PubMed Central

Arif, Atta M.; Berreau, Lisa M.

2009-01-01

Using a new N4-donor chelate ligand having a mixture of hydrophobic phenyl and hydrogen bond donor appendages, a trinuclear Ni(II) complex of the doubly deprotonated form of 2-hydroxy-1,3-diphenylpropane-1,3-dione was isolated, characterized (X-ray crystallography, elemental analysis, UV-vis, 1H NMR, FTIR, magnetic moment measurement), and evaluated for O2 reactivity. This complex, [(6-NA-6-Ph2TPANi)2(μ-PhC(O)C(O)C(O)Ph)2Ni](ClO4)2 (4), has two terminal pseudo octahedral Ni(II) centers supported by the tetradentate chelate ligand, and a central square planar Ni(II) ion ligated by oxygen atoms of two bridging enediolate ligands. In CH3CN, 4 exhibits a deep orange/brown color and λmax = 463 nm (ε = 16,000 M-1cm-1). The room temperature magnetic moment of 4, determined by Evans method, is μeff = 5.3(2) μB. This is consistent with the presence of two non-interacting high-spin Ni(II) centers, a diamagnetic central Ni(II) ion, and an overall quintet ground state. Exposure of a CH3CN solution of 4 to O2 results in the rapid loss of the orange/brown color to give a green solution. The products identified from this reaction are [(κ3-6-NA-6-Ph2TPA)Ni(O2Ph)(H2O)]ClO4 (5), benzil (PhC(O)C(O)Ph), and CO. Identification of 5 was achieved via its independent synthesis and comparison of its 1H NMR and mass spectral features with those of the 6-NA-6-Ph2TPA-containing product generated upon reaction of 4 with O2. The independently prepared sample of 5 was characterized by X-ray crystallography, elemental analysis, UV-vis, mass spectrometry, and FTIR. The O2 reactivity of 4 has relevance to the active site chemistry of Ni(II)-containing acireductone dioxygenase (Ni(II)-ARD). PMID:18959363

Precursor routes to quaternary intermetallics: Synthesis, crystal structure, and physical properties of clathrate-II Cs{sub 8}Na{sub 16}Al{sub 24}Si{sub 112}

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

Wei, Kaya; Dong, Yongkwan; Nolas, George S., E-mail: gnolas@usf.edu

A new quaternary clathrate–II composition, Cs{sub 8}Na{sub 16}Al{sub 24}Si{sub 112}, was synthesized by kinetically controlled thermal decomposition (KCTD) employing both NaSi and NaAlSi as the precursors and CsCl as a reactive flux. The crystal structure and composition of Cs{sub 8}Na{sub 16}Al{sub 24}Si{sub 112} were investigated using both Rietveld refinement and elemental analysis, and the temperature dependent transport properties were investigated. Our results indicate that KCTD with multiple precursors is an effective method for the synthesis of multinary inorganic phases that are not easily accessible by traditional solid-state synthesis or crystal growth techniques. - Graphical abstract: Quaternary Cs{sub 8}Na{sub 16}Al{sub 24}S{submore » 112} clathrate–II was synthesized for the first time by kinetically controlled thermal decomposition (KCTD) employing a NaSi+NaAlSi precursor mixture with CsCl as the reactive flux, and the structural and transport properties were investigated. Our approach demonstrates a new synthetic pathway for the synthesis of multinary inorganic compounds. This work reports the exploration of a new clathrate composition as this class of materials continues to be of interest for thermoelectrics and other energy-related applications.« less

BASS-II Experiment

NASA Image and Video Library

2014-08-02

Image taken on card 8 during BASS-II flame test session with reduced O2 partial pressure. Session conducted on GMT 213. The Burning and Suppression of Solids - II (BASS-II) investigation examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The BASS-II experiment will guide strategies for materials flammability screening for use in spacecraft as well as provide valuable data on solid fuel burning behavior in microgravity. BASS-II results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

Electrochemical studies of DNA interaction and antimicrobial activities of MnII, FeIII, CoII and NiII Schiff base tetraazamacrocyclic complexes

NASA Astrophysics Data System (ADS)

Kumar, Anuj; Vashistha, Vinod Kumar; Tevatia, Prashant; Singh, Randhir

2017-04-01

Tetraazamacrocyclic complexes of MnII, FeIII, CoII and NiII have been synthesized by template method. These tetraazamacrocycles have been analyzed with various techniques like molar conductance, IR, UV-vis, mass spectral and cyclic voltammetric studies. On the basis of all these studies, octahedral geometry has been assigned to these tetraazamacrocyclic complexes. The DNA binding properties of these macrocyclic complexes have been investigated by electronic absorption spectra, fluorescence spectra, cyclic voltammetric and differential pulse voltammetric studies. The cyclic voltammetric data showed that ipc and ipa were effectively decreased in the presence of calf thymus DNA, which is a strong evidence for the interaction of these macrocyclic complexes with the calf thymus DNA (ct-DNA). The heterogeneous electron transfer rate constant found in the order: KCoII > KNiII > KMnII which indicates that CoII macrocyclic complex has formed a strong intercalated intermediate. The Stern-Volmer quenching constant (KSV) and voltammetric binding constant were found in the order KSV(CoII) > KSV(NiII) > KSV(MnII) and K+(CoII) > K+(NiII) > K+(MnII) which shows that CoII macrocyclic complex exhibits the high interaction affinity towards ct-DNA by the intercalation binding. Biological studies of the macrocyclic complexes compared with the standard drug like Gentamycin, have shown antibacterial activities against E. coli, P. aeruginosa, B. cereus, S. aureus and antifungal activity against C. albicans.

The NAv1.7 blocker protoxin II reduces burn injury-induced spinal nociceptive processing.

PubMed

Torres-Pérez, Jose Vicente; Adamek, Pavel; Palecek, Jiri; Vizcaychipi, Marcela; Nagy, Istvan; Varga, Angelika

2018-01-01

Controlling pain in burn-injured patients poses a major clinical challenge. Recent findings suggest that reducing the activity of the voltage-gated sodium channel Na v 1.7 in primary sensory neurons could provide improved pain control in burn-injured patients. Here, we report that partial thickness scalding-type burn injury on the rat paw upregulates Na v 1.7 expression in primary sensory neurons 3 h following injury. The injury also induces upregulation in phosphorylated cyclic adenosine monophosphate response element-binding protein (p-CREB), a marker for nociceptive activation in primary sensory neurons. The upregulation in p-CREB occurs mainly in Na v 1.7-immunopositive neurons and exhibits a peak at 5 min and, following a decline at 30 min, a gradual increase from 1 h post-injury. The Na v 1.7 blocker protoxin II (ProTxII) or morphine injected intraperitoneally 15 min before or after the injury significantly reduces burn injury-induced spinal upregulation in phosphorylated serine 10 in histone H3 and phosphorylated extracellular signal-regulated kinase 1/2, which are both markers for spinal nociceptive processing. Further, ProTxII significantly reduces the frequency of spontaneous excitatory post-synaptic currents in spinal dorsal horn neurons following burn injury. Together, these findings indicate that using Na v 1.7 blockers should be considered to control pain in burn injury. • Burn injury upregulates Na v 1.7 expression in primary sensory neurons. • Burn injury results in increased activity of Na v 1.7-expressing primary sensory neurons. • Inhibiting Na v 1.7 by protoxin II reduces spinal nociceptive processing. • Na v 1.7 represents a potential target to reduce pain in burn injury.

Comparative study on kinetic adsorption of Cu(II), Cd(II) and Ni(II) ions from aqueous solutions using activated sludge and dried sludge

NASA Astrophysics Data System (ADS)

Ong, Soon-An; Toorisaka, Eiichi; Hirata, Makoto; Hano, Tadashi

2013-03-01

The adsorption of Cu(II), Cd(II) and Ni(II) ions from aqueous solutions by activated sludge and dried sludge was investigated under laboratory conditions to assess its potential in removing metal ions. The adsorption behavior of metal ions onto activated sludge and dried sludge was analyzed with Weber-Morris intra-particle diffusion model, Lagergren first-order model and pseudo second-order model. The rate constant of intra-particle diffusion on activated sludge and dried sludge increased in the sequence of Cu(II) > Ni(II) > Cd(II). According to the regression coefficients, it was observed that the kinetic adsorption data can fit better by the pseudo second-order model compared to the first-order Lagergren model with R 2 > 0.997. The adsorption capacities of metal ions onto activated sludge and dried sludge followed the sequence Ni(II) ≈ Cu(II) > Cd(II) and Cu(II) > Ni(II) > Cd(II).

Kinetics of homogeneous and surface-catalyzed mercury(II) reduction by iron(II)

USGS Publications Warehouse

Amirbahman, Aria; Kent, Douglas B.; Curtis, Gary P.; Marvin-DiPasquale, Mark C.

2013-01-01

Production of elemental mercury, Hg(0), via Hg(II) reduction is an important pathway that should be considered when studying Hg fate in environment. We conducted a kinetic study of abiotic homogeneous and surface-catalyzed Hg(0) production by Fe(II) under dark anoxic conditions. Hg(0) production rate, from initial 50 pM Hg(II) concentration, increased with increasing pH (5.5–8.1) and aqueous Fe(II) concentration (0.1–1 mM). The homogeneous rate was best described by the expression, rhom = khom [FeOH+] [Hg(OH)2]; khom = 7.19 × 10+3 L (mol min)−1. Compared to the homogeneous case, goethite (α-FeOOH) and hematite (α-Fe2O3) increased and γ-alumina (γ-Al2O3) decreased the Hg(0) production rate. Heterogeneous Hg(0) production rates were well described by a model incorporating equilibrium Fe(II) adsorption, rate-limited Hg(II) reduction by dissolved and adsorbed Fe(II), and rate-limited Hg(II) adsorption. Equilibrium Fe(II) adsorption was described using a surface complexation model calibrated with previously published experimental data. The Hg(0) production rate was well described by the expression rhet = khet [>SOFe(II)] [Hg(OH)2], where >SOFe(II) is the total adsorbed Fe(II) concentration; khet values were 5.36 × 10+3, 4.69 × 10+3, and 1.08 × 10+2 L (mol min)−1 for hematite, goethite, and γ-alumina, respectively. Hg(0) production coupled to reduction by Fe(II) may be an important process to consider in ecosystem Hg studies.

Immobilization of Rose Waste Biomass for Uptake of Pb(II) from Aqueous Solutions

PubMed Central

Ansari, Tariq Mahmood; Hanif, Muhammad Asif; Mahmood, Abida; Ijaz, Uzma; Khan, Muhammad Aslam; Nadeem, Raziya; Ali, Muhammad

2011-01-01

Rosa centifolia and Rosa gruss an teplitz distillation waste biomass was immobilized using sodium alginate for Pb(II) uptake from aqueous solutions under varied experimental conditions. The maximum Pb(II) adsorption occurred at pH 5. Immobilized rose waste biomasses were modified physically and chemically to enhance Pb(II) removal. The Langmuir sorption isotherm and pseudo-second-order kinetic models fitted well to the adsorption data of Pb(II) by immobilized Rosa centifolia and Rosa gruss an teplitz. The adsorbed metal is recovered by treating immobilized biomass with different chemical reagents (H2SO4, HCl and H3PO4) and maximum Pb(II) recovered when treated with sulphuric acid (95.67%). The presence of cometals Na, Ca(II), Al(III), Cr(III), Cr(VI), and Cu(II), reduced Pb(II) adsorption on Rosa centifolia and Rosa gruss an teplitz waste biomass. It can be concluded from the results of the present study that rose waste can be effectively used for the uptake of Pb(II) from aqueous streams. PMID:21350666

Anti-inflammatory drugs interacting with Zn(II), Cd(II) and Pt(II) metal ions.

PubMed

Dendrinou-Samara, C; Tsotsou, G; Ekateriniadou, L V; Kortsaris, A H; Raptopoulou, C P; Terzis, A; Kyriakidis, D A; Kessissoglou, D P

1998-09-01

Complexes of Zn(II), Cd(II) and Pt(II) metal ions with the anti-inflammatory drugs, 1-methyl-5-(p-toluoyl)-1H-pyrrole-2-acetic acid (Tolmetin), alpha-methyl-4-(2-methylpropyl)benzeneacetic acid (Ibuprofen), 6-methoxy-alpha-methylnaphthalene-2-acetic acid (Naproxen) and 1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indole-3-acetic acid (indomethacin) have been synthesized and characterized. In the structurally characterized Cd(naproxen)2 complex the anti-inflammatory drugs acts as bidentate chelate ligand coordinatively bound to metal ions through the deprotonated carboxylate group. Crystal data for 1: [C32H26O8Cd], orthorhombic, space group P22(1)2(1), a = 5.693(2) (A), b = 8.760(3) (A), c = 30.74(1) (A), V = 1533(1) A3, Z = 2. Antibacterial and growth inhibitory activity is higher than that of the parent ligands or the platinum(II) diamine compounds.

Simultaneous Stripping Detection of Pb(II), Cd(II) and Zn(II) Using a Bimetallic Hg-Bi/Single-Walled Carbon Nanotubes Composite Electrode

PubMed Central

Ouyang, Ruizhuo; Zhu, Zhenqian; Tatum, Clarissa E.; Chambers, James Q.; Xue, Zi-Ling

2011-01-01

A new, sensitive platform for the simultaneous electrochemical assay of Zn(II), Cd(II) and Pb(II) in aqueous solution has been developed. The platform is based on a new bimetallic Hg-Bi/single-walled carbon nanotubes (SWNTs) composite modified glassy carbon electrode (GCE), demonstrating remarkably improved performance for the anodic stripping assay of Zn(II), Cd(II) and Pb(II). The synergistic effect of Hg and Bi as well as the enlarged, activated surface and good electrical conductivity of SWNTs on GCE contribute to the enhanced activity of the proposed electrode. The analytical curves for Zn(II), Cd(II) an Pb(II) cover two linear ranges varying from 0.5 to 11 μg L-1 and 10 to 130 μg L-1 with correlation coefficients higher than 0.992. The limits of detection for Zn(II), Cd(II) are lower than 2 μg L-1 (S/N = 3). For Pb(II), moreover, there is another lower, linear range from 5 to 1100 ng L-1 with a coefficient of 0.987 and a detection limit of 0.12 ng L-1. By using the standard addition method, Zn(II), Cd(II) and Pb(II) ions in river samples were successfully determined. These results suggest that the proposed method can be applied as a simple, efficient alternative for the simultaneous monitoring of heavy metals in water samples. In addition, this method demonstrates the powerful application of carbon nanotubes in electrochemical analysis of heavy metals. PMID:21660117

Potassium Supplementation Prevents Sodium Chloride Cotransporter Stimulation during Angiotensin II Hypertension

PubMed Central

Veiras, Luciana C.; Han, Jiyang; Ralph, Donna L.; McDonough, Alicia A.

2016-01-01

Ang II hypertension increases distal tubule Na-Cl cotransporter (NCC) abundance and phosphorylation (NCCp), as well as epithelial Na+ channel (ENaC) abundance and activating cleavage. Acutely raising plasma [K+] by infusion or ingestion provokes a rapid decrease in NCCp that drives a compensatory kaliuresis. The first aim tested whether acutely raising plasma [K+] with a single 3 hr 2% potassium meal would lower NCCp in Sprague Dawley rats after 14 days of AngII (400 ng/kg/min). The potassium-rich meal neither decreased NCCp nor increased K+ excretion. AngII infused rats exhibited lower plasma [K+] versus controls (3.6 ± 0.2 vs. 4.5 ± 0.1 mmol/L, p < 0.05) suggesting that Ang II mediated ENaC activation provokes K+ depletion. The second aim tested whether doubling dietary potassium intake from 1% (A1K) to 2% (A2K) would prevent K+ depletion during AngII infusion and, thus, prevent NCC accumulation. A2K fed rats exhibited normal plasma [K+] and 2-fold higher K+ excretion and plasma [aldosterone] versus A1K. In A1K rats, NCC, NCCpS71, and NCCpT53 abundance increased 1.5- to 3-fold versus controls (p< 0.05). The rise in NCC and NCCp abundance was prevented in the A2K rats, yet blood pressure did not significantly decrease. ENaC subunit abundance and cleavage increased 1.5- to 3-fold in both A1K and A2K; ROMK abundance was unaffected by Ang II or dietary K+. In summary, the accumulation and phosphorylation of NCC seen during chronic AngII infusion hypertension is likely secondary to potassium deficiency driven by ENaC stimulation. PMID:27600183

[Evaluation of serum PIVKA-II by Lumipulse PrestoII assay].

PubMed

Hiramatsu, Kumiko; Tanaka, Yasuhito; Takagi, Kazumi; Kani, Satomi; Goto, Takaaki; Takasaka, Yoshimitsu; Matsuura, Kentaro; Sugauchi, Fuminaka; Moriyama, Kazushige; Murakami, Hiroshi; Kitajima, Sachiko; Mizokami, Masashi

2009-03-01

Measurements of serum concentrations of Des-gamma-carboxy Prothrombin (PIVKA-II) are widely used for diagnosing hepatocellular carcinoma (HCC). Recently, in Lumipulsef assay, it was reported that antibodies against alkaline phosphatase (ALP) derived from anti bleeding sheets led false high values of PIVKA-II in the patients with HCC resection. To improve the previous issue, newly developed Lumipulse PrestoII assay was examined. (1) The assay was reliable and positively correlated with the previous assays (Lumipulse f and Picolumi, R = 0.997 and 0.994 (n=115), respectively). (2) Eleven cases, which had false high values of PIVKA-II by the Lumipulsef assay, were examined by the PrestoII assay with excess of inactive ALP. The false high values of 10 cases were improved, but only one was still high. False reactivity of this case was stronger than other cases, more effective adsorption was required. (3) Comparing the absorbent activity of inactive ALP among 6 different kinds, we found inactive ALP with much higher adsorbent activity. When this inactive ALP was applied to assay, false high values of PIVKA-II were improved in all 11 cases. In conclusion, the PrestoII assay, which applies the inactive ALP with high activity, is reliable and useful for clinical screening.

IGF-II receptors and IGF-II-stimulated glucose transport in human fat cells

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

Sinha, M.K.; Buchanan, C.; Raineri-Maldonado, C.

1990-03-01

Insulin-like growth factor II (IGF-II) receptors have been described in rat but not in human adipocytes. In both species, IGF-II has been reported to stimulate glucose transport by interacting with the insulin receptor. In this study, we have unequivocally demonstrated the presence of IGF-II receptors in human adipocytes. 125I-labeled IGF-II specifically binds to intact adipocytes, membranes, and lectin-purified detergent solubilized extracts. Through the use of 0.5 mM disuccinimidyl suberate, 125I-IGF-II is cross-linked to a 260-kDa protein that is identified as the IGF-II receptor by displacement experiments with unlabeled IGF-II, IGF-I, and insulin and either by immunoprecipitation or by Western blotmore » analysis with mannose 6-phosphate receptor antibodies. The concentrations of IGF-II required for half-maximal and maximal stimulation of glucose transport in human adipocytes are 35 and 100 times more than that of insulin. The possibility of IGF-II stimulating glucose transport by interacting predominantly with the insulin receptor is suggested by the following: (1) the concentration of IGF-II that inhibits half of insulin binding is only 20 times more than that of insulin; (2) the lack of an additive effect of IGF-II and insulin for maximal stimulation of glucose transport; (3) the ability of monoclonal insulin receptor antibodies to decrease glucose transport stimulated by submaximal concentrations of both IGF-II and insulin; and (4) the ability of IGF-II to stimulate insulin receptor autophosphorylation albeit at a reduced potency when compared with insulin.« less

Synthesis and studies on Cu(II), Co(II), Ni(II) complexes of Knoevenagel β-diketone ligands.

PubMed

Sumathi, S; Tharmaraj, P; Sheela, C D; Anitha, C

2012-11-01

Transition metal complexes of various acetylacetone based ligands of the type ML [where M=Cu(II), Ni(II), Co(II); L=3-(aryl)-pentane-2,4-dione] have been synthesized. The structural features have been derived from their elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, (1)H NMR, Mass and ESR spectral studies. Conductivity measurements reveal that all the complexes are non-electrolytic in nature. Spectroscopic and other analytical data of the complexes suggest octahedral geometry for other metal(II) complexes. The redox behavior of the copper(II) complexes have been studied by cyclic voltammetry. The free ligands and their metal complexes have been screened for their in vitro biological activities against the bacteria Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus as well as the fungus Candida albicans by well diffusion method. The zone of inhibition value indicates that the most of the metal(II) complexes are found to possess increased activities compared to those of the free ligands. All synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG) efficiency of the ligands (L1-L3) was found to be considerable effect than that of urea and KDP (potassium dihydrogen phosphate). Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis and studies on Cu(II), Co(II), Ni(II) complexes of Knoevenagel β-diketone ligands

NASA Astrophysics Data System (ADS)

Sumathi, S.; Tharmaraj, P.; Sheela, C. D.; Anitha, C.

2012-11-01

Transition metal complexes of various acetylacetone based ligands of the type ML [where M = Cu(II), Ni(II), Co(II); L = 3-(aryl)-pentane-2,4-dione] have been synthesized. The structural features have been derived from their elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, 1H NMR, Mass and ESR spectral studies. Conductivity measurements reveal that all the complexes are non-electrolytic in nature. Spectroscopic and other analytical data of the complexes suggest octahedral geometry for other metal(II) complexes. The redox behavior of the copper(II) complexes have been studied by cyclic voltammetry. The free ligands and their metal complexes have been screened for their in vitro biological activities against the bacteria Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus as well as the fungus Candida albicans by well diffusion method. The zone of inhibition value indicates that the most of the metal(II) complexes are found to possess increased activities compared to those of the free ligands. All synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG) efficiency of the ligands (L1-L3) was found to be considerable effect than that of urea and KDP (potassium dihydrogen phosphate).

Better prognostic marker in ICU - APACHE II, SOFA or SAP II!

PubMed

Naqvi, Iftikhar Haider; Mahmood, Khalid; Ziaullaha, Syed; Kashif, Syed Mohammad; Sharif, Asim

2016-01-01

This study was designed to determine the comparative efficacy of different scoring system in assessing the prognosis of critically ill patients. This was a retrospective study conducted in medical intensive care unit (MICU) and high dependency unit (HDU) Medical Unit III, Civil Hospital, from April 2012 to August 2012. All patients over age 16 years old who have fulfilled the criteria for MICU admission were included. Predictive mortality of APACHE II, SAP II and SOFA were calculated. Calibration and discrimination were used for validity of each scoring model. A total of 96 patients with equal gender distribution were enrolled. The average APACHE II score in non-survivors (27.97+8.53) was higher than survivors (15.82+8.79) with statistically significant p value (<0.001). The average SOFA score in non-survivors (9.68+4.88) was higher than survivors (5.63+3.63) with statistically significant p value (<0.001). SAP II average score in non-survivors (53.71+19.05) was higher than survivors (30.18+16.24) with statistically significant p value (<0.001). All three tested scoring models (APACHE II, SAP II and SOFA) would be accurate enough for a general description of our ICU patients. APACHE II has showed better calibration and discrimination power than SAP II and SOFA.

The tarantula toxins ProTx-II and huwentoxin-IV differentially interact with human Nav1.7 voltage sensors to inhibit channel activation and inactivation.

PubMed

Xiao, Yucheng; Blumenthal, Kenneth; Jackson, James O; Liang, Songping; Cummins, Theodore R

2010-12-01

The voltage-gated sodium channel Na(v)1.7 plays a crucial role in pain, and drugs that inhibit hNa(v)1.7 may have tremendous therapeutic potential. ProTx-II and huwentoxin-IV (HWTX-IV), cystine knot peptides from tarantula venoms, preferentially block hNa(v)1.7. Understanding the interactions of these toxins with sodium channels could aid the development of novel pain therapeutics. Whereas both ProTx-II and HWTX-IV have been proposed to preferentially block hNa(v)1.7 activation by trapping the domain II voltage-sensor in the resting configuration, we show that specific residues in the voltage-sensor paddle of domain II play substantially different roles in determining the affinities of these toxins to hNa(v)1.7. The mutation E818C increases ProTx-II's and HWTX-IV's IC(50) for block of hNa(v)1.7 currents by 4- and 400-fold, respectively. In contrast, the mutation F813G decreases ProTx-II affinity by 9-fold but has no effect on HWTX-IV affinity. It is noteworthy that we also show that ProTx-II, but not HWTX-IV, preferentially interacts with hNa(v)1.7 to impede fast inactivation by trapping the domain IV voltage-sensor in the resting configuration. Mutations E1589Q and T1590K in domain IV each decreased ProTx-II's IC(50) for impairment of fast inactivation by ~6-fold. In contrast mutations D1586A and F1592A in domain-IV increased ProTx-II's IC(50) for impairment of fast inactivation by ~4-fold. Our results show that whereas ProTx-II and HWTX-IV binding determinants on domain-II may overlap, domain II plays a much more crucial role for HWTX-IV, and contrary to what has been proposed to be a guiding principle of sodium channel pharmacology, molecules do not have to exclusively target the domain IV voltage-sensor to influence sodium channel inactivation.

Synthesis, Characterization and Antibacterial Activity of 1,4-di[ aminomethylene carboxyl] phenylene (H2L) and its Complexes Co(II), Cu (II), Zn(II) and Cd (II)

NASA Astrophysics Data System (ADS)

Sultan, J. S.; Fezea, S. M.; Mousa, F. H.

2018-05-01

A binucleating tetradentate Schiff base ligand, 1,4- di[amino methylene carboxylic] phenylene (H2L) and its forth new binuclear complexes [Co(II), Cu(II), Zn(II) and Cd(II)] were prepared via reaction metal (II) chloride with ligand (H2L) using 2:1 (M:L) in ethanol solvent. The new ligand (H2L) and its complexes were characterized by elemental microanalysis (C.H.N), atomic absorption, chloride content, molar conductance’s magnetic susceptibility, FTIR UV- Vis spectral and, 1H, 13 C- NMR (for H2L). The antibacterial activity with bacteria activity with bacteria, Staphylococcus aureus, Bacillus and Esccherichia Coli were studied.

Central sympathoexcitatory actions of angiotensin II: role of type 1 angiotensin II receptors.

PubMed

DiBona, G F

1999-01-01

The role of the renin-angiotensin system in the control of sympathetic nerve activity is reviewed. Two general mechanisms are considered, one that involves the effects of circulating angiotensin II (AngII) on the central nervous system and a second that involves the central nervous system effects of AngII that originates within the central nervous system. The role of type 1 AngII receptors in discrete brain sites that mediate the sympathoexcitatory actions of AngII of either circulating or central nervous system origin is examined. AngII of circulating origin has ready access to the subfornical organ and area postrema, where it can bind to type 1 AngII receptors on neurons whose connections to the nucleus tractus solitarius and rostral ventrolateral medulla result in sympathoexcitation. In the rostral ventrolateral medulla, angiotensin peptides of central nervous system origin, likely involving angiotensin species in addition to AngII and binding to receptors other than type 1 or 2 AngII receptors, tonically support sympathetic nerve activity.

Synthesis, spectral characterization, structural investigation and antimicrobial studies of mononuclear Cu(II), Ni(II), Co(II), Zn(II) and Cd(II) complexes of a new potentially hexadentate N2O4 Schiff base ligand derived from salicylaldehyde

NASA Astrophysics Data System (ADS)

Keypour, Hassan; Shayesteh, Maryam; Rezaeivala, Majid; Chalabian, Firoozeh; Elerman, Yalcin; Buyukgungor, Orhan

2013-01-01

A new potentially hexadentate N2O4 Schiff base ligand, H2L derived from condensation reaction of an aromatic diamine and salicylaldehyde, and its metal complexes were characterized by elemental analyses, IR, UV-Vis, EI-MS, 1H and 13C NMR spectra, as well as conductance measurements. It has been originated that the Schiff base ligand with Cu(II), Ni(II), Co(II), Cd(II) and Zn(II) ions form mononuclear complexes on 1:1 (metal:ligand) stoichiometry. The conductivity data confirm the non-electrolytic nature of the complexes. Also the crystal structures of the complexes [ZnL] and [CoL] have also been determined by using X-ray crystallographic technique. The Zn(II) and Co(II) complexes show a tetrahedral configuration. Electronic absorption spectra of the Cu(II) and Ni(II) complexes suggest a square-planar geometry around the central metal ion. The synthesized compounds have antibacterial activity against the three Gram-positive bacteria: Bacillus cereus, Enterococcus faecalis and Listeria monocytogenes and also against the three Gram-negative bacteria: Salmonella paraB, Citrobacter freundii and Enterobacter aerogenes. The results showed that in some cases the antibacterial activity of complexes were more than nalidixic acid and amoxicillin as standards.

Charge transfer complexes of adenosine-5‧-monophosphate and cytidine-5‧-monophosphate with water-soluble cobalt(II) Schiff base complexes in aqueous solution

NASA Astrophysics Data System (ADS)

Boghaei, Davar M.; Gharagozlou, Mehrnaz

2006-01-01

Water-soluble cobalt(II) tetradentate Schiff base complexes have been shown to form charge transfer (CT) complexes with a series of nucleoside monophosphates including adenosine-5‧-monophosphate (AMP) and cytidine-5‧-monophosphate (CMP). The investigated water-soluble cobalt(II) Schiff base complexes are (i) disodium[{bis(5-sulfo-salicylaldehyde)-o-phenylenediiminato}cobalt(II)], Na2[Co(SO3-salophen)] (1); (ii) disodium[{bis(5-sulfo-salicylaldehyde)-4,5-dimethyl-o-phenylenediiminato}cobalt(II)], Na2[Co(SO3-sal-4,5-dmophen)] (2) and (iii) disodium[{bis(4-methoxy-5-sulfo-salicylaldehyde)-4,5-dimethyl-o-phenylenediiminato}cobalt(II)], Na2[Co(SO3-4-meosal-4,5-dmophen)] (3). The formation constant and thermodynamic parameters for charge transfer complex formation of water-soluble cobalt(II) Schiff base complexes with nucleoside monophosphates were determined spectrophotometrically in aqueous solution at constant ionic strength (I = 0.2 mol dm-3 KNO3) under physiological condition (pH 7.0) and at various temperatures between 288 and 308 K. The stoichiometry has been found to be 1:1 (water-soluble cobalt(II) Schiff base complex: nucleoside monophosphate) in each case. Our spectroscopic and thermodynamic results show that the interaction of water-soluble cobalt(II) Schiff base complexes with the investigated nucleoside monophosphates occurs mainly through the phosphate group. The trend of the interaction according to the cobalt(II) Schiff base complexes due to electronic and steric factors is as follows: Na2[Co(SO3-salophen)] > Na2[Co(SO3-sal-4,5-dmophen)] > Na2[Co(SO3-4-meosal-4,5-dmophen)]. Also the trend of the interaction of a given cobalt(II) Schiff base complex according to the nucleoside monophosphate is as follows: CMP > AMP.

Syntheses, structures, and properties of imidazolate-bridged Cu(II)-Cu(II) and Cu(II)-Zn(II) dinuclear complexes of a single macrocyclic ligand with two hydroxyethyl pendants.

PubMed

Li, Dongfeng; Li, Shuan; Yang, Dexi; Yu, Jiuhong; Huang, Jin; Li, Yizhi; Tang, Wenxia

2003-09-22

The imidazolate-bridged homodinuclear Cu(II)-Cu(II) complex, [(CuimCu)L]ClO(4).0.5H(2)O (1), and heterodinuclear Cu(II)-Zn(II) complex, [(CuimZnL(-)(2H))(CuimZnL(-)(H))](ClO(4))(3) (2), of a single macrocyclic ligand with two hydroxyethyl pendants, L (L = 3,6,9,16,19,22-hexaaza-6,19-bis(2-hydroxyethyl)tricyclo[22,2,2,2(11,14)]triaconta-1,11,13,24,27,29-hexaene), have been synthesized as possible models for copper-zinc superoxide dismutase (Cu(2),Zn(2)-SOD). Their crystal structures analyzed by X-ray diffraction methods have shown that the structures of the two complexes are markedly different. Complex 1 crystallizes in the orthorhombic system, containing an imidazolate-bridged dicopper(II) [Cu-im-Cu](3+) core, in which the two copper(II) ions are pentacoordinated by virtue of an N4O environment with a Cu.Cu distance of 5.999(2) A, adopting the geometry of distorted trigonal bipyramid and tetragonal pyramid, respectively. Complex 2 crystallizes in the triclinic system, containing two similar Cu-im-Zn cores in the asymmetric unit, in which both the Cu(II) and Zn(II) ions are pentacoordinated in a distorted trigonal bipyramid geometry, with the Cu.Zn distance of 5.950(1)/5.939(1) A, respectively. Interestingly, the macrocyclic ligand with two arms possesses a chairlike (anti) conformation in complex 1, but a boatlike (syn) conformation in complex 2. Magnetic measurements and ESR spectroscopy of complex 1 have revealed the presence of an antiferromagnetic exchange interaction between the two Cu(II) ions. The ESR spectrum of the Cu(II)-Zn(II) heterodinuclear complex 2 displayed a typical signal for mononuclear trigonal bipyramidal Cu(II) complexes. From pH-dependent ESR and electronic spectroscopic studies, the imidazolate bridges in the two complexes have been found to be stable over broad pH ranges. The cyclic voltammograms of the two complexes have been investigated. Both of the two complexes can catalyze the dismutation of superoxide and show rather high activity.

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.

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.

Production and Isomeric Distribution of Xanthylium Cation Pigments and Their Precursors in Wine-like Conditions: Impact of Cu(II), Fe(II), Fe(III), Mn(II), Zn(II), and Al(III).

PubMed

Guo, Anque; Kontoudakis, Nikolaos; Scollary, Geoffrey R; Clark, Andrew C

2017-03-22

This study establishes the influence of Cu(II), Fe(II), Fe(III), Zn(II), Al(III), and Mn(II) on the oxidative production of xanthylium cations from (+)-catechin and either tartaric acid or glyoxylic acid in model wine systems. The reaction was studied at 25 °C using UHPLC and LC-HRMS for the analysis of phenolic products and their isomeric distribution. In addition to the expected products, a colorless product, tentatively assigned as a lactone, was detected for the first time. The results show the importance of Fe ions and a synergistic influence of Mn(II) in degrading tartaric acid to glyoxylic acid, whereas the other metal ions had minimal activity in this mechanistic step. Fe(II) and Fe(III) were shown to mediate the (+)-catechin-glyoxylic acid addition reaction, a role previously attributed to only Cu(II). Importantly, the study demonstrates that C-8 addition products of (+)-catechin are promoted by Cu(II), whereas C-6 addition products are promoted by Fe ions.

AIM-9X Block II Sidewinder (AIM-9X Blk II)

DTIC Science & Technology

2015-12-01

Selected Acquisition Report (SAR) RCS: DD- A &T(Q& A )823-442 AIM-9X Block II Sidewinder (AIM-9X Blk II) As of FY 2017 President’s Budget Defense...MDAP - Major Defense Acquisition Program MILCON - Military Construction N/ A - Not Applicable O&M - Operations and Maintenance ORD - Operational...15:14:10 UNCLASSIFIED 5 Mission and Description The AIM-9X Block II Sidewinder (AIM-9X Blk II) short-range air-to-air missile is a long term

Enhanced angiotensin-converting enzyme activity and systemic reactivity to angiotensin II in normotensive rats exposed to a high-sodium diet

PubMed Central

Crestani, Sandra; Júnior, Arquimedes Gasparotto; Marques, Maria C.A.; Sullivan, Jennifer C.; Webb, R. Clinton; da Silva-Santos, J. Eduardo

2016-01-01

A high salt diet is associated with reduced activity of the renin–angiotensin–aldosterone system (RAAS). However, normotensive rats exposed to high sodium do not show changes in systemic arterial pressure. We hypothesized that, despite the reduced circulating amounts of angiotensin II induced by a high salt diet, the cardiovascular system’s reactivity to angiotensin II is increased in vivo, contributing to maintain arterial pressure at normal levels. Male Wistar rats received chow containing 0.27% (control), 2%, 4%, or 8% NaCl for six weeks. The high-sodium diet did not lead to changes in arterial pressure, although plasma levels of angiotensin II and aldosterone were reduced in the 4% and 8% NaCl groups. The 4% and 8% NaCl groups showed enhanced pressor responses to angiotensin I and II, accompanied by unchanged and increased angiotensin-converting enzyme activity, respectively. The 4% NaCl group showed increased expression of angiotensin II type 1 receptors and reduced expression of angiotensin II type 2 receptors in the aorta. In addition, the hypotensive effect of losartan was reduced in both 4% and 8% NaCl groups. In conclusion these results explain, at least in part, why the systemic arterial pressure is maintained at normal levels in non-salt sensitive and healthy rats exposed to a high salt diet, when the functionality of RAAS appears to be blunted, as well as suggest that angiotensin II has a crucial role in the vascular dysfunction associated with high salt intake, even in the absence of hypertension. PMID:24321189

Alkali and alkaline earth metallic (AAEM) species leaching and Cu(II) sorption by biochar.

PubMed

Li, Mi; Lou, Zhenjun; Wang, Yang; Liu, Qiang; Zhang, Yaping; Zhou, Jizhi; Qian, Guangren

2015-01-01

Alkali and alkaline earth metallic (AAEM) species water leaching and Cu(II) sorption by biochar prepared from two invasive plants, Spartina alterniflora (SA) and water hyacinth (WH), were explored in this work. Significant amounts of Na and K can be released (maximum leaching for Na 59.0 mg g(-1) and K 79.9 mg g(-1)) from SA and WH biochar when they are exposed to contact with water. Cu(II) removal by biochar is highly related with pyrolysis temperature and environmental pH with 600-700 °C and pH of 6 showing best performance (29.4 and 28.2 mg g(-1) for SA and WH biochar). Cu(II) sorption exerts negligible influence on Na/K/Mg leaching but clearly promotes the release of Ca. Biochars from these two plant species provide multiple benefits, including nutrient release (K), heavy metal immobilization as well as promoting the aggregation of soil particles (Ca) for soil amelioration. AAEM and Cu(II) equilibrium concentrations in sorption were analyzed by positive matrix factorization (PMF) to examine the factors underlying the leaching and sorption behavior of biochar. The identified factors can provide insightful understanding on experimental phenomena. Copyright © 2014 Elsevier Ltd. All rights reserved.

Selective adsorption of Pb(II), Cd(II), and Ni(II) ions from aqueous solution using chitosan-MAA nanoparticles.

PubMed

Heidari, Aghdas; Younesi, Habibollah; Mehraban, Zahra; Heikkinen, Harri

2013-10-01

Chitosan-MAA nanoparticles (CS-MAA) with an average size of 10-70 nm were prepared by polymerizing chitosan with methacrylic acid in aqueous solution. The physicochemical properties of nanoparticles were investigated using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS) and nuclear magnetic resonance (NMR). The adsorption of Pb(II), Cd(II) and Ni(II) from aqueous solution on CS-MAA was studied in a batch system. The effects of the solution pH, initial metal concentration, contact time, and dosage of the adsorbent on the adsorption process were examined. The experimental data were analyzed using the pseudo-second-order kinetic equations and the Langmuir, Freundlich and Redlish-Peterson isotherms. The maximum adsorption capacity was 11.30, 1.84, and 0.87 mg/g for Pb(II), Cd(II) and Ni(II) ions, respectively, obtained by the Langmuir isotherm. However, the adsorption isotherm was better explained by the Freundlich rather than by the Langmuir model, as the high correlation coefficients (R(2)>0.99) were obtained at a higher confidence level. Copyright © 2013 Elsevier B.V. All rights reserved.

Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers.

PubMed

Monier, M; Ayad, D M; Sarhan, A A

2010-04-15

The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction. 2009 Elsevier B.V. All rights reserved.

Immunological Functions of the Membrane Proximal Region of MHC Class II Molecules

PubMed Central

Harton, Jonathan; Jin, Lei; Hahn, Amy; Drake, Jim

2016-01-01

Major histocompatibility complex (MHC) class II molecules present exogenously derived antigen peptides to CD4 T cells, driving activation of naïve T cells and supporting CD4-driven immune functions. However, MHC class II molecules are not inert protein pedestals that simply bind and present peptides. These molecules also serve as multi-functional signaling molecules delivering activation, differentiation, or death signals (or a combination of these) to B cells, macrophages, as well as MHC class II-expressing T cells and tumor cells. Although multiple proteins are known to associate with MHC class II, interaction with STING (stimulator of interferon genes) and CD79 is essential for signaling. In addition, alternative transmembrane domain pairing between class II α and β chains influences association with membrane lipid sub-domains, impacting both signaling and antigen presentation. In contrast to the membrane-distal region of the class II molecule responsible for peptide binding and T-cell receptor engagement, the membrane-proximal region (composed of the connecting peptide, transmembrane domain, and cytoplasmic tail) mediates these “non-traditional” class II functions. Here, we review the literature on the function of the membrane-proximal region of the MHC class II molecule and discuss the impact of this aspect of class II immunobiology on immune regulation and human disease. PMID:27006762

Synthesis and characterization of hydroxyapatite nanoparticles impregnated on apple pomace to enhanced adsorption of Pb(II), Cd(II), and Ni(II) ions from aqueous solution.

PubMed

Chand, Piar; Pakade, Yogesh B

2015-07-01

Hydroxyapatite nanoparticles were synthesized, characterized, and impregnated onto apple pomace surface (HANP@AP) for efficient removal of Pb(II), Cd(II), and Ni(II) ions from water. HANP@AP was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), transmission electron microscope (TEM), X-ray diffraction (XRD), and surface area analysis. Batch sorption studies were carried out to investigate the influence of different parameters as amount of dose (g), pH, time (min), and initial concentration (mg L(-1)) on adsorption process. Experimental kinetic data followed pseudo-second-order model and equilibrium data well fitted to Langmuir adsorption model with maximum adsorption capacities of 303, 250, and 100 mg g(-1) for Pb(II), Cd(II), and Ni(II) ions, respectively. Competitive adsorption of Pb(II), Cd(II), and Ni(II) ions in presences of each other was studied to evaluate the removal efficiency of HANP@AP against multi metal-loaded water. HANP@AP was successfully applied to real industrial wastewater with 100 % removal of all three metal ions even at high concentration. HANP@AP could be recycled for four, four, and three cycles in case of Pb(II), Cd(II) and Ni(II), respectively. The study showed that HANP@AP is fast, cost effective, and environmental friendly adsorbent for removal of Pb(II), Cd(II), and Ni(II) ions from real industrial wastewater.

Spectroscopic characterization, antioxidant and antitumour studies of novel bromo substituted thiosemicarbazone and its copper(II), nickel(II) and palladium(II) complexes

NASA Astrophysics Data System (ADS)

Jagadeesh, M.; Lavanya, M.; Kalangi, Suresh K.; Sarala, Y.; Ramachandraiah, C.; Varada Reddy, A.

2015-01-01

A new, slightly distorted octahedral complex of copper(II), square planar complexes of nickel(II) and palladium(II) with 2,4‧-dibromoacetophenone thiosemicarbazone (DBAPTSC) are synthesized. The ligand and the complexes are characterized by FT-IR, FT-Raman, powder X-ray diffraction studies. The IR and Raman data are correlated for the presence of the functional groups which specifically helped in the confirmation of the compounds. In addition, the free ligand is unambiguously characterized by 1H and 13C NMR spectroscopy while the copper(II) complex is characterized by electron paramagnetic resonance spectroscopy (EPR). The g values for the same are found to be 2.246 (g1), 2.012 (g2) and 2.005 (g3) which suggested rhombic distortions. The HOMO-LUMO band gap calculations for these compounds are found to be in between 0.5 and 4.0 eV and these compounds are identified as semiconducting materials. The synthesized ligand and its copper(II), nickel(II) and palladium(II) complexes are subjected to antitumour activity against the HepG2 human hepatoblastoma cell lines. Among all the compounds, nickel(II) complex is found to exert better antitumour activity with 57.6% of cytotoxicity.

Cadmium(II) and lead(II) adsorption onto hetero-atom functional mesoporous silica and activated carbon

NASA Astrophysics Data System (ADS)

Machida, Motoi; Fotoohi, Babak; Amamo, Yoshimasa; Mercier, Louis

2012-07-01

Adsorption of cadmium(II) and lead(II) on amino-, mercapto-functionalized mesoporous silica (HMS) and carboxylic-functionalized activated carbon (AC) were examined. The resultant isotherms fitted the Langmuir model and amino-functionalized HMS exhibited the highest adsorption capacity for both cadmium(II) and lead(II). Adsorption affinities for cadmium(II) were always greater than those for lead(II) in all three adsorbent types, while the difference between the two values was the largest for mercapto-functionalized HMS indicating a selective adsorption of cadmium(II). Influence of equilibrium solution pH on adsorption of cadmium(II), lead(II) and their binary mixtures was also studied. Carboxylic-functionalized AC adsorbed cadmium(II) and lead(II) in a wide pH range than conditions for the mercapto-functionalized HMS. It was concluded that each functional group had its own characteristics and advantages for adsorption of heavy metal ions; amino-groups showed high adsorption capacity, while mercapto-groups had good selectivity toward cadmium(II) adsorption and a wide solution pH in adsorption by carboxylic-groups were established in this study.

Adsorption of aqueous Cd(II) and Pb(II) on activated carbon nanopores prepared by chemical activation of doum palm shell.

PubMed

Gaya, Umar Ibrahim; Otene, Emmanuel; Abdullah, Abdul Halim

2015-01-01

Non-uniformly sized activated carbons were derived from doum palm shell, a new precursor, by carbonization in air and activation using KOH, NaOH and ZnCl2. The activated carbon fibres were characterised by X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, particle size analysis and evaluated for Cd(II) and Pb(II) removal. The 40-50 nm size, less graphitic, mesoporous NaOH activated carbon yielded high adsorption efficiency, pointing largely to the influence surface area. The performance of the KOH based activated carbon was arguably explained for the first time in terms of crystallinity. The efficiencies of the mesoporous ZnCl2-formulated activated carbon diminished due to the presence of larger particles. Batch adsorption of divalent metals revealed dependence on adsorbent dose, agitation time, pH and adsorbate concentrations with high adsorption efficiencies at optimum operating parameters. The equilibrium profiles fitted Langmuir and Freundlich isotherms, and kinetics favoured pseudo-second order model. The study demonstrated the practicability of the removal of alarming levels of cadmium and lead ions from industrial effluents.

A green separation strategy for neodymium (III) from cobalt (II) and nickel (II) using an ionic liquid-based aqueous two-phase system.

PubMed

Chen, Yuehua; Wang, Huiyong; Pei, Yuanchao; Wang, Jianji

2018-05-15

It is significant to develop sustainable strategies for the selective separation of rare earth from transition metals from fundamental and practical viewpoint. In this work, an environmentally friendly solvent extraction approach has been developed to selectively separate neodymium (III) from cobalt (II) and nickel (II) by using an ionic liquid-based aqueous two phase system (IL-ATPS). For this purpose, a hydrophilic ionic liquid (IL) tetrabutylphosphonate nitrate ([P 4444 ][NO 3 ]) was prepared and used for the formation of an ATPS with NaNO 3 . Binodal curves of the ATPSs have been determined for the design of extraction process. The extraction parameters such as contact time, aqueous phase pH, content of phase-formation components of NaNO 3 and the ionic liquid have been investigated systematically. It is shown that under optimal conditions, the extraction efficiency of neodymium (III) is as high as 99.7%, and neodymium (III) can be selectively separated from cobalt (II) and nickel (II) with a separation factor of 10 3 . After extraction, neodymium (III) can be stripped from the IL-rich phase by using dilute aqueous sodium oxalate, and the ILs can be quantitatively recovered and reused in the next extraction process. Since [P 4444 ][NO 3 ] works as one of the components of the ATPS and the extractant for the neodymium, no organic diluent, extra etractant and fluorinated ILs are used in the separation process. Thus, the strategy described here shows potential in green separation of neodymium from cobalt and nickel by using simple IL-based aqueous two-phase system. Copyright © 2018 Elsevier B.V. All rights reserved.

Thermodynamic Analysis of Nickel(II) and Zinc(II) Adsorption to Biochar.

PubMed

Alam, Md Samrat; Gorman-Lewis, Drew; Chen, Ning; Flynn, Shannon L; Ok, Yong Sik; Konhauser, Kurt O; Alessi, Daniel S

2018-05-21

While numerous studies have investigated metal uptake from solution by biochar, few of these have developed a mechanistic understanding of the adsorption reactions that occur at the biochar surface. In this study, we explore a combined modeling and spectroscopic approach for the first time to describe the molecular level adsorption of Ni(II) and Zn(II) to five types of biochar. Following thorough characterization, potentiometric titrations were carried out to measure the proton (H + ) reactivity of each biochar, and the data was used to develop protonation models. Surface complexation modeling (SCM) supported by synchrotron-based extended X-ray absorption fine structure (EXAFS) was then used to gain insights into the molecular scale metal-biochar surface reactions. The SCM approach was combined with isothermal titration calorimetry (ITC) data to determine the thermodynamic driving forces of metal adsorption. Our results show that the reactivity of biochar toward Ni(II) and Zn(II) directly relates to the site densities of biochar. EXAFS along with FT-IR analyses, suggest that Ni(II) and Zn(II) adsorption occurred primarily through proton-active carboxyl (-COOH) and hydroxyl (-OH) functional groups on the biochar surface. SCM-ITC analyses revealed that the enthalpies of protonation are exothermic and Ni(II) and Zn(II) complexes with biochar surface are slightly exothermic to slightly endothermic. The results obtained from these combined approaches contribute to the better understanding of molecular scale metal adsorption onto the biochar surface, and will facilitate the further development of thermodynamics-based, predictive approaches to biochar removal of metals from contaminated water.

Electrochemical, spectroscopic, and photophysical properties of structurally diverse polyazine-bridged Ru(II),Pt(II) and Os(II),Ru(II),Pt(II) supramolecular motifs.

PubMed

Knoll, Jessica D; Arachchige, Shamindri M; Wang, Guangbin; Rangan, Krishnan; Miao, Ran; Higgins, Samantha L H; Okyere, Benjamin; Zhao, Meihua; Croasdale, Paul; Magruder, Katherine; Sinclair, Brian; Wall, Candace; Brewer, Karen J

2011-09-19

Five new tetrametallic supramolecules of the motif [{(TL)(2)M(dpp)}(2)Ru(BL)PtCl(2)](6+) and three new trimetallic light absorbers [{(TL)(2)M(dpp)}(2)Ru(BL)](6+) (TL = bpy = 2,2'-bipyridine or phen = 1,10-phenanthroline; M = Ru(II) or Os(II); BL = dpp = 2,3-bis(2-pyridyl)pyrazine, dpq = 2,3-bis(2-pyridyl)quinoxaline, or bpm = 2,2'-bipyrimidine) were synthesized and their redox, spectroscopic, and photophysical properties investigated. The tetrametallic complexes couple a Pt(II)-based reactive metal center to Ru and/or Os light absorbers through two different polyazine BL to provide structural diversity and interesting resultant properties. The redox potential of the M(II/III) couple is modulated by M variation, with the terminal Ru(II/III) occurring at 1.58-1.61 V and terminal Os(II/III) couples at 1.07-1.18 V versus Ag/AgCl. [{(TL)(2)M(dpp)}(2)Ru(BL)](PF(6))(6) display terminal M(dπ)-based highest occupied molecular orbitals (HOMOs) with the dpp(π*)-based lowest unoccupied molecular orbital (LUMO) energy relatively unaffected by the nature of BL. The coupling of Pt to the BL results in orbital inversion with localization of the LUMO on the remote BL in the tetrametallic complexes, providing a lowest energy charge separated (CS) state with an oxidized terminal Ru or Os and spatially separated reduced BL. The complexes [{(TL)(2)M(dpp)}(2)Ru(BL)](6+) and [{(TL)(2)M(dpp)}(2)Ru(BL)PtCl(2)](6+) efficiently absorb light throughout the UV and visible regions with intense metal-to-ligand charge transfer (MLCT) transitions in the visible at about 540 nm (M = Ru) and 560 nm (M = Os) (ε ≈ 33,000-42,000 M(-1) cm(-1)) and direct excitation to the spin-forbidden (3)MLCT excited state in the Os complexes about 720 nm. All the trimetallic and tetrametallic Ru-based supramolecular systems emit from the terminal Ru(dπ)→dpp(π*) (3)MLCT state, λ(max)(em) ≈ 750 nm. The tetrametallic systems display complex excited state dynamics with quenching of the (3)MLCT emission at

Theoretical (in B3LYP/6-3111++G** level), spectroscopic (FT-IR, FT-Raman) and thermogravimetric studies of gentisic acid and sodium, copper(II) and cadmium(II) gentisates.

PubMed

Regulska, E; Kalinowska, M; Wojtulewski, S; Korczak, A; Sienkiewicz-Gromiuk, J; Rzączyńska, Z; Swisłocka, R; Lewandowski, W

2014-11-11

The DFT calculations (B3LYP method with 6-311++G(d,p) mixed with LanL2DZ for transition metals basis sets) for different conformers of 2,5-dihydroxybenzoic acid (gentisic acid), sodium 2,5-dihydroxybenzoate (gentisate) and copper(II) and cadmium(II) gentisates were done. The proposed hydrated structures of transition metal complexes were based on the results of experimental findings. The theoretical geometrical parameters and atomic charge distribution were discussed. Moreover Na, Cu(II) and Cd(II) gentisates were synthesized and the composition of obtained compounds was revealed by means of elemental and thermogravimetric analyses. The FT-IR and FT-Raman spectra of gentisic acid and gentisates were registered and the effect of metals on the electronic charge distribution of ligand was discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Shark class II invariant chain reveals ancient conserved relationships with cathepsins and MHC class II.

PubMed

Criscitiello, Michael F; Ohta, Yuko; Graham, Matthew D; Eubanks, Jeannine O; Chen, Patricia L; Flajnik, Martin F

2012-03-01

The invariant chain (Ii) is the critical third chain required for the MHC class II heterodimer to be properly guided through the cell, loaded with peptide, and expressed on the surface of antigen presenting cells. Here, we report the isolation of the nurse shark Ii gene, and the comparative analysis of Ii splice variants, expression, genomic organization, predicted structure, and function throughout vertebrate evolution. Alternative splicing to yield Ii with and without the putative protease-protective, thyroglobulin-like domain is as ancient as the MHC-based adaptive immune system, as our analyses in shark and lizard further show conservation of this mechanism in all vertebrate classes except bony fish. Remarkable coordinate expression of Ii and class II was found in shark tissues. Conserved Ii residues and cathepsin L orthologs suggest their long co-evolution in the antigen presentation pathway, and genomic analyses suggest 450 million years of conserved Ii exon/intron structure. Other than an extended linker preceding the thyroglobulin-like domain in cartilaginous fish, the Ii gene and protein are predicted to have largely similar physiology from shark to man. Duplicated Ii genes found only in teleosts appear to have become sub-functionalized, as one form is predicted to play the same role as that mediated by Ii mRNA alternative splicing in all other vertebrate classes. No Ii homologs or potential ancestors of any of the functional Ii domains were found in the jawless fish or lower chordates. Copyright © 2011 Elsevier Ltd. All rights reserved.

Synthesis, characterization and anti-microbial activity of a novel macrocyclic ligand derived from the reaction of 2,6-pyridinedicarboxylic acid with homopiperazine and its Co(II), Ni(II), Cu(II), and Zn(II) complexes

NASA Astrophysics Data System (ADS)

Soleimani, Esmaiel

2011-05-01

The preparation of a novel macrocyclic ligand ( 1), N,N'-diethylhomopiperazinyl,2,6-pyridinedicarboxylate and its Co(II), Ni(II), Cu(II), and Zn(II) complexes are described. The ligand was prepared in EtOH from the reaction of dipotassium salt of 2,6-pyridinedicarboxylic acid with 1,2-dibromoethane in the presence of homopiperazine. Reaction of macrocyclic ligand ( 1) in EtOH with CoCl 2.6H 2O, NiCl 2.6H 2O, CuCl 2.2H 2O, and ZnCl 2·2H 2O yielded the complexes with the general formula [M(L)Cl 2] {where M = Co(II) ( 2), Ni(II) ( 3), Cu(II) ( 4), Zn ( 5), respectively}. The analysis of IR, 1H and 13C NMR spectral data of macrocyclic ligand ( 1) and its Zn(II) complex ( 5) together with their molar conductivity values, and the magnetic moments of the complexes suggest that the macrocyclic ligand ( 1) is bonded to metal(II) ions through two oxygen atoms of ester moiety and the two nitrogen atoms of homopiperazine ring. The electronic spectral data of these complexes in DMSO are in good agreement with the octahedral coordination of M(II) ions. The ligand field parameters for these complexes, i.e. splitting energy and Racah parameter were calculated to be 14,945 and 673 cm -1 for the Co(II) ( 2), 16,260 and 774 cm -1 for the Ni(II) ( 3) complexes respectively. The spliting energy of 17,262 cm -1 was obtained for the Cu(II) complex ( 4).

Surface complexation modeling calculation of Pb(II) adsorption onto the calcined diatomite

NASA Astrophysics Data System (ADS)

Ma, Shu-Cui; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

2015-12-01

Removal of noxious heavy metal ions (e.g. Pb(II)) by surface adsorption of minerals (e.g. diatomite) is an important means in the environmental aqueous pollution control. Thus, it is very essential to understand the surface adsorptive behavior and mechanism. In this work, the Pb(II) apparent surface complexation reaction equilibrium constants on the calcined diatomite and distributions of Pb(II) surface species were investigated through modeling calculations of Pb(II) based on diffuse double layer model (DLM) with three amphoteric sites. Batch experiments were used to study the adsorption of Pb(II) onto the calcined diatomite as a function of pH (3.0-7.0) and different ionic strengths (0.05 and 0.1 mol L-1 NaCl) under ambient atmosphere. Adsorption of Pb(II) can be well described by Freundlich isotherm models. The apparent surface complexation equilibrium constants (log K) were obtained by fitting the batch experimental data using the PEST 13.0 together with PHREEQC 3.1.2 codes and there is good agreement between measured and predicted data. Distribution of Pb(II) surface species on the diatomite calculated by PHREEQC 3.1.2 program indicates that the impurity cations (e.g. Al3+, Fe3+, etc.) in the diatomite play a leading role in the Pb(II) adsorption and dominant formation of complexes and additional electrostatic interaction are the main adsorption mechanism of Pb(II) on the diatomite under weak acidic conditions.

The inorganic speciation of tin(II) in aqueous solution

NASA Astrophysics Data System (ADS)

Cigala, Rosalia Maria; Crea, Francesco; De Stefano, Concetta; Lando, Gabriele; Milea, Demetrio; Sammartano, Silvio

2012-06-01

This paper reports new voltammetric measurements on the interactions between tin(II) and the most important natural inorganic ligands, OH-, Cl-, F-, CO32-, SO42- and PO43-. For a better understanding of tin(II) speciation, an analysis is also given of prior data on the same systems from the literature. The formation constants were determined at t = 25 °C in different ionic media and at different ionic strengths, specifically the following: Sn(OH)q (0.1 ⩽ I/mol L-1 ⩽ 1.0 in NaNO3), SnClr and Sn(OH)Cl (0.1 ⩽ I/mol L-1 ⩽ 2.3 in Na(NO3, Cl)), Sn(SO4)r (0.1 ⩽ I/mol L-1 ⩽ 1.6 in Na(NO3, SO4)), SnHqCO3 and SnHqPO4 (0.15 ⩽ I/mol L-1 ⩽ 1.0 in NaNO3), where the subscripts r and q represent the stoichiometric coefficients. Concerning the SnFr species, reliable literature values were considered (0.15 ⩽ I/mol L-1 ⩽ 1.0 in NaClO4). Fifteen voltammetric measurements were performed in synthetic seawater; the total seawater binding ability was evaluated by a model in which synthetic seawater is expressed as a single salt, BA. The formation of species between tin(II) and the anion of the marine salt (A) was also proposed, and the corresponding stability constants at different salinities (5 ⩽ S ⩽ 50) were reported. In addition, studies on the solubility of Sn(OH)2(s) were carried out using voltammetry and light scattering measurements. The "extra-stability" of the mixed species with respect to the parent species was evaluated, in particular for Sn(OH)Cl and the corresponding species involving the anion of the marine salt (A). The dependence of the formation constants on ionic strength was analysed using extended Debye-Hückel and Specific ion Interaction Theory (SIT) type equations. Tin(II) speciation was also evaluated in different natural fluid conditions, where, in all cases, carbonate complexation was predominant, hampering the formation of hydrolytic species throughout the investigated pH range. Moreover, some formation enthalpy changes were calculated

Spectroscopic evaluation of Co(II), Ni(II) and Cu(II) complexes derived from thiosemicarbazone and semicarbazone

NASA Astrophysics Data System (ADS)

Chandra, Sulekh; Kumar, Anil

2007-12-01

Co(II), Ni(II) and Cu(II) complexes were synthesized with thiosemicarbazone (L 1) and semicarbazone (L 2) derived from 2-acetyl furan. These complexes were characterized by elemental analysis, molar conductance, magnetic moment, mass, IR, electronic and EPR spectral studies. The molar conductance measurement of the complexes in DMSO corresponds to non-electrolytic nature. All the complexes are of high-spin type. On the basis of different spectral studies six coordinated geometry may be assigned for all the complexes except Co(L) 2(SO 4) and Cu(L) 2(SO 4) [where L = L 1 and L 2] which are of five coordinated square pyramidal geometry.

Cu(II), Co(II) and Ni(II) complexes of new Schiff base ligand: Synthesis, thermal and spectroscopic characterizations

NASA Astrophysics Data System (ADS)

Refat, Moamen S.; El-Sayed, Mohamed Y.; Adam, Abdel Majid A.

2013-04-01

Cu(II), Co(II), and Ni(II) complexes were synthesized from 2-[(5-o-chlorophenylazo-2-hydroxybenzylidin)amino]-phenol Schiff base (H2L). Metal ions coordinate in a tetradentate or hexadentate features with these O2N donor ligand, which are characterized by elemental analyses, magnetic moments, infrared, Raman laser, electronic, and 1H NMR spectral studies. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). Reactions with Cu(II), Co(II) and Ni(II), resulted [Cu(H2L)(H2O)2(Cl)]Cl, [Co(H2L)(H2O)3]Cl2ṡ3H2O and [Ni(H2L)(H2O)2]Cl2ṡ6H2O. The thermal decomposition behavior of H2L complexes has been investigated by thermogravimetric analysis (TG/DTG) at a heating rate of 10 °C min-1 under nitrogen atmosphere. The brightness side in this study is to take advantage for the preparation and characterizations of single phases of CuO, CoO and NiO nanoparticles using H2L complexes as precursors via a solid-state decomposition procedure. The crystalline structures of products using X-ray diffractometer (XRD), morphology of particles by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) were investigated.

Iodometric determination of peroxydiphosphate in the presence of copper(II) or iron(II) as catalyst.

PubMed

Kapoor, S; Sharma, P D; Gupta, Y K

1975-09-01

Peroxydiphosphate can be determined iodometrically in the presence of a large excess of potassium iodide with copper(II) or iron(II) as catalyst through the operation of the Cu(II)/Cu(I) or Fe(II)/Fe(III) cycle. The method is applicable in HClO(4), H(2)SO(4), HCl and CH(3)COOH acid media in the range 0.1-1.0M studied. Nickel, manganese(II), cobalt(II), silver, chloride and phosphate are without effect.

Kangaroo IGF-II is structurally and functionally similar to the human [Ser29]-IGF-II variant.

PubMed

Yandell, C A; Francis, G L; Wheldrake, J F; Upton, Z

1999-06-01

Kangaroo IGF-II has been purified from western grey kangaroo (Macropus fuliginosus) serum and characterised in a number of in vitro assays. In addition, the complete cDNA sequence of mature IGF-II has been obtained by reverse-transcription polymerase chain reaction. Comparison of the kangaroo IGF-II cDNA sequence with known IGF-II sequences from other species revealed that it is very similar to the human variant, [Ser29]-hIGF-II. Both the variant and kangaroo IGF-II contain an insert of nine nucleotides that encode the amino acids Leu-Pro-Gly at the junction of the B and C domains of the mature protein. The deduced kangaroo IGF-II protein sequence also contains three other amino acid changes that are not observed in human IGF-II. These amino acid differences share similarities with the changes described in many of the IGF-IIs reported for non-mammalian species. Characterisation of human IGF-II, kangaroo IGF-II, chicken IGF-II and [Ser29]-hIGF-II in a number of in vitro assays revealed that all four proteins are functionally very similar. No significant differences were observed in the ability of the IGF-IIs to bind to the bovine IGF-II/cation-independent mannose 6-phosphate receptor or to stimulate protein synthesis in rat L6 myoblasts. However, differences were observed in their abilities to bind to IGF-binding proteins (IGFBPs) present in human serum. Kangaroo, chicken and [Ser29]-hIGF-II had lower apparent affinities for human IGFBPs than did human IGF-II. Thus, it appears that the major circulating form of IGF-II in the kangaroo and a minor form of IGF-II found in human serum are structurally and functionally very similar. This suggests that the splice site that generates both the variant and major form of human IGF-II must have evolved after the divergence of marsupials from placental mammals.

The adsorption of silver on potassium cyanocobalt(II)ferrate(II).

PubMed

Wald, M; Soyka, W; Kaysser, B

1973-04-01

A procedure is described for recovering silver from industrial sewage (mining and photo-industry etc) with the aid of the ion-exchanger potassium cyanocobalt(II)ferrate(II) (KCFC). Silver is easily removed by simple mixing with KCFC, even from solutions containing less than 1 g of silver per ton of solution. The process is performed at room temperature at pH < 7. There is no interference from a 600-fold amount of Ca, Cu(II), Zn, Cd, Pb, and Fe(II). Pure silver may be obtained by dissolution of the ion-exchanger in potassium cyanide solution, subsequent precipitation as sulphide, and roasting, or by melting it out of the ion-exchanger after heat treatment in a high-frequency furnace. With 1 kg of KCFC, 1.25 kg of silver may be extracted from solution. The process is simple and economic.

Synthesis, spectroscopic characterization, DNA interaction and biological activities of Mn(II), Co(II), Ni(II) and Cu(II) complexes with [(1H-1,2,4-triazole-3-ylimino)methyl]naphthalene-2-ol

NASA Astrophysics Data System (ADS)

Gaber, Mohamed; El-Wakiel, Nadia A.; El-Ghamry, Hoda; Fathalla, Shaimaa K.

2014-11-01

Manganese(II), cobalt(II), nickel(II) and copper(II) complexes of [(1H-1,2,4-triazole-3-ylimino)methyl]naphthalene-2-ol have been synthesized. The structure of complexes have been characterized by elemental analysis, molar conductance, magnetic moment measurements and spectral (IR, 1H NMR, EI-mass, UV-Vis and ESR), and thermal studies. The results showed that the chloro and nitrato Cu(II) complexes have octahedral geometry while Ni(II), Co(II) and Mn(II) complexes in addition to acetato Cu(II) complex have tetrahedral geometry. The possible structures of the metal complexes have been computed using the molecular mechanic calculations using the hyper chem. 8.03 molecular modeling program to confirm the proposed structures. The kinetic and thermodynamic parameters of the thermal decomposition steps were calculated from the TG curves. The binding modes of the complexes with DNA have been investigated by UV-Vis absorption titration. The results showed that the mode of binding of the complexes to DNA is intercalative or non-intercalative binding modes. Schiff base and its metal complexes have been screened for their in vitro antimicrobial activities against Gram positive bacteria (Staphylococcus aureus), Gram negative bacteria (Escherichia coli and Pesudomonas aeruginosa), fungi (Asperigllus flavus and Mucer) and yeast (Candida albicans and Malassezia furfur).

Dinuclear metallacycles with single M-O(H)-M bridges [M = Fe(II), Co(II), Ni(II), Cu(II)]: effects of large bridging angles on structure and antiferromagnetic superexchange interactions.

PubMed

Reger, Daniel L; Pascui, Andrea E; Foley, Elizabeth A; Smith, Mark D; Jezierska, Julia; Ozarowski, Andrew

2014-02-17

The reactions of M(ClO4)2·xH2O and the ditopic ligands m-bis[bis(1-pyrazolyl)methyl]benzene (Lm) or m-bis[bis(3,5-dimethyl-1-pyrazolyl)methyl]benzene (Lm*) in the presence of triethylamine lead to the formation of monohydroxide-bridged, dinuclear metallacycles of the formula [M2(μ-OH)(μ-Lm)2](ClO4)3 (M = Fe(II), Co(II), Cu(II)) or [M2(μ-OH)(μ-Lm*)2](ClO4)3 (M = Co(II), Ni(II), Cu(II)). With the exception of the complexes where the ligand is Lm and the metal is copper(II), all of these complexes have distorted trigonal bipyramidal geometry around the metal centers and unusual linear (Lm*) or nearly linear (Lm) M-O-M angles. For the two solvates of [Cu2(μ-OH)(μ-Lm)2](ClO4)3, the Cu-O-Cu angles are significantly bent and the geometry about the metal is distorted square pyramidal. All of the copper(II) complexes have structural distortions expected for the pseudo-Jahn-Teller effect. The two cobalt(II) complexes show moderate antiferromagnetic coupling, -J = 48-56 cm(-1), whereas the copper(II) complexes show very strong antiferromagnetic coupling, -J = 555-808 cm(-1). The largest coupling is observed for [Cu2(μ-OH)(μ-Lm*)2](ClO4)3, the complex with a Cu-O-Cu angle of 180°, such that the exchange interaction is transmitted through the dz(2) and the oxygen s and px orbitals. The interaction decreases, but it is still significant, as the Cu-O-Cu angle decreases and the character of the metal orbital becomes increasingly d(x(2)-y(2)). These intermediate geometries and magnetic interactions lead to spin Hamiltonian parameters for the copper(II) complexes in the EPR spectra that have large E/D ratios and one g matrix component very close to 2. Density functional theory calculations were performed using the hybrid B3LYP functional in association with the TZVPP basis set, resulting in reasonable agreement with the experiments.

Evidence for Na+ Influx via the NtpJ Protein of the KtrII K+ Uptake System in Enterococcus hirae

PubMed Central

Kawano, Miyuki; Abuki, Ryoko; Igarashi, Kazuei; Kakinuma, Yoshimi

2000-01-01

The ntpJ gene, a cistron located at the tail end of the vacuolar-type Na+-ATPase (ntp) operon of Enterococcus hirae, encodes a transporter of the KtrII K+ uptake system. We found that K+ accumulation in the ntpJ-disrupted mutant JEM2 was markedly enhanced by addition of valinomycin at pH 10. Studies of the membrane potential (ΔΨ; inside negative) by 3,3′-dihexyloxacarbocyanine iodide fluorescence revealed that the ΔΨ was hyperpolarized at pH 10 in JEM2; the ΔΨ values of the parent strain ATCC 9790 and JEM2, estimated by determining the equilibrium distribution of K+ or Rb+ in the presence of valinomycin, were −118 and −160 mV, respectively. ΔΨ generation at pH 10 was accomplished by an electrogenic Na+ efflux via the Na+-ATPase, whose levels in the two strains were quite similar. Na+ uptake driven by an artificially imposed ΔΨ (inside negative) was missing in JEM2, suggesting that NtpJ mediates Na+ movement in addition to K+ movement. Finally, the growth of JEM2 arrested in K+-limited high-Na+ medium at pH 10 was restored by addition of valinomycin. These results suggest that NtpJ mediates electrogenic transport of K+ as well as Na+, that it likely mediates K+ and Na+ cotransport, and that Na+ movement via NtpJ is the major Na+ reentry pathway at high pH values. PMID:10762252

BASS II

NASA Image and Video Library

2014-02-14

ISS038-E-047576 (14 Feb. 2014) --- NASA astronaut Rick Mastracchio, Expedition 38 flight engineer, works with the Burning and Suppression of Solids (BASS-II) experiment in the Microgravity Science Glovebox (MSG) located in the Destiny laboratory of the International Space Station. BASS-II explores how different substances burn in microgravity with benefits for combustion on Earth and fire safety in space.

BASS II

NASA Image and Video Library

2014-02-14

ISS038-E-047582 (14 Feb. 2014) --- NASA astronaut Rick Mastracchio, Expedition 38 flight engineer, works with the Burning and Suppression of Solids (BASS-II) experiment in the Microgravity Science Glovebox (MSG) located in the Destiny laboratory of the International Space Station. BASS-II explores how different substances burn in microgravity with benefits for combustion on Earth and fire safety in space.

40 CFR Table II-2 to Subpart II - Collection Efficiencies of Anaerobic Processes

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Collection Efficiencies of Anaerobic Processes II Table II-2 to Subpart II Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt. 98...

40 CFR Table II-2 to Subpart II - Collection Efficiencies of Anaerobic Processes

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Collection Efficiencies of Anaerobic Processes II Table II-2 to Subpart II Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt. 98...

Antimicrobial and mutagenic activity of some carbono- and thiocarbonohydrazone ligands and their copper(II), iron(II) and zinc(II) complexes.

PubMed

Bacchi, A; Carcelli, M; Pelagatti, P; Pelizzi, C; Pelizzi, G; Zani, F

1999-06-15

Several mono- and bis- carbono- and thiocarbonohydrazone ligands have been synthesised and characterised; the X-ray diffraction analysis of bis(phenyl 2-pyridyl ketone) thiocarbonohydrazone is reported. The coordinating properties of the ligands have been studied towards Cu(II), Fe(II), and Zn(II) salts. The ligands and the metal complexes were tested in vitro against Gram positive and Gram negative bacteria, yeasts and moulds. In general, the bisthiocarbonohydrazones possess the best antimicrobial properties and Gram positive bacteria are the most sensitive microorganisms. Bis(ethyl 2-pyridyl ketone) thiocarbonohydrazone, bis(butyl 2-pyridyl ketone)thiocarbonohydrazone and Cu(H2nft)Cl2 (H2nft, bis(5-nitrofuraldehyde)thiocarbonohydrazone) reveal a strong activity with minimum inhibitory concentrations of 0.7 microgram ml-1 against Bacillus subtilis and of 3 micrograms ml-1 against Staphylococcus aureus. Cu(II) complexes are more effective than Fe(II) and Zn(II) ones. All bisthiocarbono- and carbonohydrazones are devoid of mutagenic properties, with the exception of the compounds derived from 5-nitrofuraldehyde. On the contrary a weak mutagenicity, that disappears in the copper complexes, is exhibited by monosubstituted thiocarbonohydrazones.

Synthesis and characterization of new complexes of nickel (II), palladium (II) and platinum(II) with derived sulfonamide ligand: Structure, DFT study, antibacterial and cytotoxicity activities

NASA Astrophysics Data System (ADS)

Bouchoucha, Afaf; Zaater, Sihem; Bouacida, Sofiane; Merazig, Hocine; Djabbar, Safia

2018-06-01

The synthesis, characterization and biological study of new nickel (II), palladium (II), and platinum (II) complexes with sulfamethoxazole ligand used in pharmaceutical field, were reported. [MLCl2].nH2O is the general formula obtained for Pd(II) and Pt(II) complexes. These complexes have been prepared and characterized by elemental analysis, FTIR, 1HNMR spectral, magnetic measurements, UV-Visible spectra, and conductivity. The DFT calculation was applied to optimize the geometric structure of the Pd(II) and Pt(II) complexes. A new single-crystal X-ray structure of the Ni(II) complex has been determined. It crystallized in monoclinic system with P 21/c space group and Z = 8. The invitro antibacterial activity of ligand and complexes against Escherichia coli, P. aeruginosa, Klebsiella pneumoniae, S. aureus, Bacillus subtilis species has been carried out and compared using agar-diffusion method. The Pd(II) and Pt(II) complexes showed a remarkable inhibition against bacteria tested. The invitro cytotoxicity assay of the complexes against three cell lines chronic myelogenous leukaemia (K562), human colon adenocarcinoma (HT-29) and breast cancer (MCF-7) was also reported.

Chemically modified activated carbon with 1-acylthiosemicarbazide for selective solid-phase extraction and preconcentration of trace Cu(II), Hg(II) and Pb(II) from water samples.

PubMed

Gao, Ru; Hu, Zheng; Chang, Xijun; He, Qun; Zhang, Lijun; Tu, Zhifeng; Shi, Jianping

2009-12-15

A new sorbent 1-acylthiosemicarbazide-modified activated carbon (AC-ATSC) was prepared as a solid-phase extractant and applied for removing of trace Cu(II), Hg(II) and Pb(II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 3, the maximum static adsorption capacity of Cu(II), Hg(II) and Pb(II) onto the AC-ATSC were 78.20, 67.80 and 48.56 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 3.0 mL of 2% CS(NH2)2 and 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation. According to the definition of IUPAC, the detection limits (3sigma) of this method for Cu(II), Hg(II) and Pb(II) were 0.20, 0.12 and 0.45 ng mL(-1), respectively. The relative standard deviation under optimum conditions is less than 4.0% (n=8). The prepared sorbent was applied for the preconcentration of trace Cu(II), Hg(II) and Pb(II) in certified and water samples with satisfactory results.

Identification and Characterization of Novel Immunomodulatory Bursal-derived Pentapeptide-II (BPP-II)*

PubMed Central

Feng, Xiu-Li; Liu, Qing-Tao; Cao, Rui-Bing; Zhou, Bin; Ma, Zhi-Yong; Deng, Wen-Lei; Wei, Jian-Chao; Qiu, Ya-Feng; Wang, Fang-Quan; Gu, Jin-Yan; Wang, Feng-Juan; Zheng, Qi-Sheng; Ishag, Hassan; Chen, Pu-Yan

2012-01-01

The bursa of Fabricius, the acknowledged central humoral immune organ, plays a vital role in B lymphocyte differentiation. However, there are few reports of the molecular basis of the mechanism on immune induction and potential antitumor activity of bursal-derived peptides. In this paper, a novel bursal-derived pentapeptide-II (BPP-II, MTLTG) was isolated and exerted immunomodulatory functions on antibody responses in vitro. Gene microarray analyses demonstrated that BPP-II regulated expression of 2478 genes in a mouse-derived hybridoma cell line. Immune-related gene ontology functional procedures were employed for further functional analysis. Furthermore, the majority of BPP-II-regulated pathways were associated with immune responses and tumor processes. Moreover, BPP-II exhibited immunomodulatory effects on antigen-specific immune responses in vivo, including enhancement of avian influenza virus (H9N2 subtype)-specific antibody and cytokine production and modification of T cell immunophenotypes and lymphocyte proliferation. Finally, BPP-II triggered p53 expression and stabilization and selectively inhibited tumor cell proliferation. These data identified the multifunctional factor, BPP-II, as a novel biomaterial representing an important linking between the humoral central immune system and immune induction, including antitumor. Information generated in this study elucidates further the mechanisms involved in humoral immune system and represents the potential basis of effective immunotherapeutic strategies for treating human tumors and immune improvement. PMID:22184121

Identification and characterization of novel immunomodulatory bursal-derived pentapeptide-II (BPP-II).

PubMed

Feng, Xiu-Li; Liu, Qing-Tao; Cao, Rui-Bing; Zhou, Bin; Ma, Zhi-Yong; Deng, Wen-Lei; Wei, Jian-Chao; Qiu, Ya-Feng; Wang, Fang-Quan; Gu, Jin-Yan; Wang, Feng-Juan; Zheng, Qi-Sheng; Ishag, Hassan; Chen, Pu-Yan

2012-02-03

The bursa of Fabricius, the acknowledged central humoral immune organ, plays a vital role in B lymphocyte differentiation. However, there are few reports of the molecular basis of the mechanism on immune induction and potential antitumor activity of bursal-derived peptides. In this paper, a novel bursal-derived pentapeptide-II (BPP-II, MTLTG) was isolated and exerted immunomodulatory functions on antibody responses in vitro. Gene microarray analyses demonstrated that BPP-II regulated expression of 2478 genes in a mouse-derived hybridoma cell line. Immune-related gene ontology functional procedures were employed for further functional analysis. Furthermore, the majority of BPP-II-regulated pathways were associated with immune responses and tumor processes. Moreover, BPP-II exhibited immunomodulatory effects on antigen-specific immune responses in vivo, including enhancement of avian influenza virus (H9N2 subtype)-specific antibody and cytokine production and modification of T cell immunophenotypes and lymphocyte proliferation. Finally, BPP-II triggered p53 expression and stabilization and selectively inhibited tumor cell proliferation. These data identified the multifunctional factor, BPP-II, as a novel biomaterial representing an important linking between the humoral central immune system and immune induction, including antitumor. Information generated in this study elucidates further the mechanisms involved in humoral immune system and represents the potential basis of effective immunotherapeutic strategies for treating human tumors and immune improvement.

Luminal angiotensin II stimulates rat medullary thick ascending limb chloride transport in the presence of basolateral norepinephrine.

PubMed

Baum, Michel

2016-02-15

Angiotensin II (ANG II) is secreted by the proximal tubule resulting in a luminal concentration that is 100- to 1,000-fold greater than that in the blood. Luminal ANG II has been shown to stimulate sodium transport in the proximal tubule and distal nephron. Surprisingly, luminal ANG II inhibits NaCl transport in the medullary thick ascending limb (mTAL), a nephron segment responsible for a significant amount of NaCl absorption from the glomerular ultrafiltrate. We confirmed that addition of 10(-8) M ANG II to the lumen inhibited mTAL chloride transport (220 ± 19 to 165 ± 25 pmol·mm(-1)·min(-1), P < 0.01) and examined whether an interaction with basolateral norepinephrine existed to simulate the in vivo condition of an innervated tubule. We found that in the presence of a 10(-6) M norepinephrine bath, luminal ANG II stimulated mTAL chloride transport from 298 ± 18 to 364 ± 42 pmol·mm(-1)·min(-1) (P < 0.05). Stimulation of chloride transport by luminal ANG II was also observed with 10(-3) M bath dibutyryl cAMP in the bathing solution and bath isoproterenol. A bath of 10(-5) H-89 blocked the stimulation of chloride transport by norepinephrine and prevented the effect of luminal ANG II to either stimulate or inhibit chloride transport. Bath phentolamine, an α-adrenergic agonist, also prevented the decrease in mTAL chloride transport by luminal ANG II. Thus luminal ANG II increases chloride transport with basolateral norepinephrine; an effect likely mediated by stimulation of cAMP. Alpha-1 adrenergic stimulation prevents the inhibition of chloride transport by luminal ANG II. Copyright © 2016 the American Physiological Society.

Effects of Mg II and Ca II ionization on ab-initio solar chromosphere models

NASA Technical Reports Server (NTRS)

Rammacher, W.; Cuntz, M.

1991-01-01

Acoustically heated solar chromosphere models are computed considering radiation damping by (non-LTE) emission from H(-) and by Mg II and Ca II emission lines. The radiative transfer equations for the Mg II k and Ca II K emission lines are solved using the core-saturation method with complete redistribution. The Mg II k and Ca II K cooling rates are compared with the VAL model C. Several substantial improvements over the work of Ulmschneider et al. (1987) are included. It is found that the rapid temperature rises caused by the ionization of Mg II are not formed in the middle chromosphere, but occur at larger atmospheric heights. These models represent the temperature structure of the 'real' solar chromosphere much better. This result is a major precondition for the study of ab-initio models for solar flux tubes based on MHD wave propagation and also for ab-initio models for the solar transition layer.

Biogeochemistry of Fe(II) oxidation in a photosynthetic microbial mat: Implications for Precambrian Fe(II) oxidation

NASA Astrophysics Data System (ADS)

Trouwborst, Robert E.; Johnston, Anne; Koch, Gretchen; Luther, George W.; Pierson, Beverly K.

2007-10-01

We studied the role of microbial photosynthesis in the oxidation of Fe(II) to Fe(III) in a high Fe(II) and high Mn(II) hot spring devoid of sulfide and atmospheric oxygen in the source waters. In situ light and dark microelectrode measurements of Fe(II), Mn(II) and O 2 were made in the microbial mat consisting of cyanobacteria and anoxygenic photosynthetic Chloroflexus sp. We show that Fe(II) oxidation occurred when the mat was exposed to varying intensities of sunlight but not near infrared light. We did not observe any Mn(II) oxidation under any light or dark condition over the pH range 5-7. We observed the impact of oxygenic photosynthesis on Fe(II) oxidation, distinct from the influence of atmospheric O 2 and anoxygenic photosynthesis. In situ Fe(II) oxidation rates in the mats and cell suspensions exposed to light are consistent with abiotic oxidation by O 2. The oxidation of Fe(II) to form primary Fe(III) phases contributed to banded iron-formations (BIFs) during the Precambrian. Both oxygenic photosynthesis, which produces O 2 as an oxidizing waste product, and anoxygenic photosynthesis in which Fe(II) is used to fix CO 2 have been proposed as Fe(II) oxidation mechanisms. Although we do not know the specific mechanisms responsible for all Precambrian Fe(II) oxidation, we assessed the relative importance of both mechanisms in this modern hot spring environment. In this environment, cyanobacterial oxygen production accounted for all the observed Fe(II) oxidation. The rate data indicate that a modest population of cyanobacteria could have mediated sufficient Fe(II) oxidation for some BIFs.

Biosorption of Fe(II) and Mn(II) Ions from Aqueous Solution by Rice Husk Ash

PubMed Central

Zhao, Jiaying; Jiang, Zhao; Shan, Dexin; Lu, Yan

2014-01-01

Rice husk ash (RHA), an agricultural waste, was used as biosorbent for the removal of Iron(II) and Manganese(II) ions from aqueous solutions. The structural and morphological characteristics of RHA and its elemental compositions before and after adsorption of Fe(II) and Mn(II) were determined by scanning electron microscopic (SEM) and X-ray fluorescence (XRF) analyses. Batch experiments were carried out to determine the influence of initial pH, contact time, adsorbent dosage, and initial concentration on the removal of Fe(II) and Mn(II) ions. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of the metal ions by RHA. The correlation coefficient (R 2) of Langmuir and Freundlich isotherm models equals 0.995 and 0.901 for Fe(II), 0.9862 and 0.8924 for Mn(II), respectively, so the Langmuir model fitted the equilibrium data better than the Freundlich isotherm model. The mean free energy values evaluated from the D-R model indicated that the biosorption of Fe(II) and Mn(II) onto RHA was physical in nature. Experimental data also showed that the biosorption processes of both metal ions complied with the pseudo-second-order kinetics. PMID:24982918

Solid phase selective separation and preconcentration of Cu(II) by Cu(II)-imprinted polymethacrylic microbeads.

PubMed

Dakova, Ivanka; Karadjova, Irina; Ivanov, Ivo; Georgieva, Ventsislava; Evtimova, Bisera; Georgiev, George

2007-02-12

Ion-imprinted polymer (IIP) particles are prepared by copolymerization of methacrylic acid as monomer, trimethylolpropane trimethacrylate as crosslinking agent and 2,2'-azo-bis-isobutyronitrile as initiator in the presence of Cu(II), a Cu(II)-4-(2-pyridylazo)resorcinol (Cu(II)-PAR) complex, and PAR only. A batch procedure is used for the determination of the characteristics of the Cu(II) solid phase extraction from the IIP produced. The results obtained show that the Cu(II)-PAR IIP has the greatest adsorption capacity (37.4 micromol g(-1) of dry copolymer) among the IIPs investigated. The optimal pH value for the quantitative preconcentration is 7, and full desorption is achieved by 1 M HNO(3). The selectivity coefficients (S(Cu/Me)) for Me=Ni(II), Co(II) are 45.0 and 38.5, respectively. It is established that Cu(II)-PAR IIPs can be used repeatedly without a considerable adsorption capacity loss. The determination of Cu(II) ions in seawater shows that the interfering matrix does not influence the preconcentration and selectivity values of the Cu(II)-PAR IIPs. The detection and quantification limits are 0.001 micromol L(-1) (3sigma) and 0.003 micromol L(-1) (6sigma), respectively.

Use of APACHE II and SAPS II to predict mortality for hemorrhagic and ischemic stroke patients.

PubMed

Moon, Byeong Hoo; Park, Sang Kyu; Jang, Dong Kyu; Jang, Kyoung Sool; Kim, Jong Tae; Han, Yong Min

2015-01-01

We studied the applicability of the Acute Physiology and Chronic Health Evaluation II (APACHE II) and Simplified Acute Physiology Score II (SAPS II) in patients admitted to the intensive care unit (ICU) with acute stroke and compared the results with the Glasgow Coma Scale (GCS) and National Institutes of Health Stroke Scale (NIHSS). We also conducted a comparative study of accuracy for predicting hemorrhagic and ischemic stroke mortality. Between January 2011 and December 2012, ischemic or hemorrhagic stroke patients admitted to the ICU were included in the study. APACHE II and SAPS II-predicted mortalities were compared using a calibration curve, the Hosmer-Lemeshow goodness-of-fit test, and the receiver operating characteristic (ROC) curve, and the results were compared with the GCS and NIHSS. Overall 498 patients were included in this study. The observed mortality was 26.3%, whereas APACHE II and SAPS II-predicted mortalities were 35.12% and 35.34%, respectively. The mean GCS and NIHSS scores were 9.43 and 21.63, respectively. The calibration curve was close to the line of perfect prediction. The ROC curve showed a slightly better prediction of mortality for APACHE II in hemorrhagic stroke patients and SAPS II in ischemic stroke patients. The GCS and NIHSS were inferior in predicting mortality in both patient groups. Although both the APACHE II and SAPS II systems can be used to measure performance in the neurosurgical ICU setting, the accuracy of APACHE II in hemorrhagic stroke patients and SAPS II in ischemic stroke patients was superior. Copyright © 2014 Elsevier Ltd. All rights reserved.

Studies on Some Biologically Cobalt(II), Copper(II) and Zinc(II) Complexes With ONO, NNO and SNO Donor Pyrazinoylhydrazine-Derived Ligands

PubMed Central

Praveen, Marapaka; Sherazi, Syed K. A.

1998-01-01

Biologically active complexes of Co(II), Ni(II), Cu(II) and Zn(II) with novel ONO, NNO and SNO donor pyrazinoylhydrazine-derived compounds have been prepared and characterized on the basis of analytical data and various physicochemical studies. Distorted octahedral structures for all the complexes have been proposed. The synthesized ligands and their complexes have been screened for their antibacterial activity against bacterial species Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumonae. The activity data show the metal complexes to be more active than the parent free ligands against one or more bacterial species. PMID:18475857

VELOCITY-RESOLVED [C ii] EMISSION AND [C ii]/FIR MAPPING ALONG ORION WITH HERSCHEL *,**

PubMed Central

Goicoechea, Javier R.; Teyssier, D.; Etxaluze, M.; Goldsmith, P.F.; Ossenkopf, V.; Gerin, M.; Bergin, E.A.; Black, J.H.; Cernicharo, J.; Cuadrado, S.; Encrenaz, P.; Falgarone, E.; Fuente, A.; Hacar, A.; Lis, D.C.; Marcelino, N.; Melnick, G.J.; Müller, H.S.P.; Persson, C.; Pety, J.; Röllig, M.; Schilke, P.; Simon, R.; Snell, R.L.; Stutzki, J.

2015-01-01

We present the first ~7.5′×11.5′ velocity-resolved (~0.2 km s−1) map of the [C ii] 158 μm line toward the Orion molecular cloud 1 (OMC 1) taken with the Herschel/HIFI instrument. In combination with far-infrared (FIR) photometric images and velocity-resolved maps of the H41α hydrogen recombination and CO J=2-1 lines, this data set provides an unprecedented view of the intricate small-scale kinematics of the ionized/PDR/molecular gas interfaces and of the radiative feedback from massive stars. The main contribution to the [C ii] luminosity (~85 %) is from the extended, FUV-illuminated face of the cloud (G0>500, nH>5×103 cm−3) and from dense PDRs (G≳104, nH≳105 cm−3) at the interface between OMC 1 and the H ii region surrounding the Trapezium cluster. Around ~15 % of the [C ii] emission arises from a different gas component without CO counterpart. The [C ii] excitation, PDR gas turbulence, line opacity (from [13C ii]) and role of the geometry of the illuminating stars with respect to the cloud are investigated. We construct maps of the L[C ii]/LFIR and LFIR/MGas ratios and show that L[C ii]/LFIR decreases from the extended cloud component (~10−2–10−3) to the more opaque star-forming cores (~10−3–10−4). The lowest values are reminiscent of the “[C ii] deficit” seen in local ultra-luminous IR galaxies hosting vigorous star formation. Spatial correlation analysis shows that the decreasing L[C ii]/LFIR ratio correlates better with the column density of dust through the molecular cloud than with LFIR/MGas. We conclude that the [C ii] emitting column relative to the total dust column along each line of sight is responsible for the observed L[C ii]/LFIR variations through the cloud. PMID:26568638

Spectroscopic investigation of new water soluble Mn(II)(2) and Mg(II)(2) complexes for the substrate binding models of xylose/glucose isomerases.

PubMed

Patra, Ayan; Bera, Manindranath

2014-01-30

In methanol, the reaction of stoichiometric amounts of Mn(OAc)(2)·4H(2)O and the ligand H(3)hpnbpda [H(3)hpnbpda=N,N'-bis(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine-N,N'-diacetic acid] in the presence of NaOH, afforded a new water soluble dinuclear manganese(II) complex, [Mn2(hpnbpda)(μ-OAc)] (1). Similarly, the reaction of Mg(OAc)(2)·4H(2)O and the ligand H3hpnbpda in the presence of NaOH, in methanol, yielded a new water soluble dinuclear magnesium(II) complex, [Mg2(hpnbpda)(μ-OAc)(H2O)2] (2). DFT calculations have been performed for the structural optimization of complexes 1 and 2. The DFT optimized structure of complex 1 shows that two manganese(II) centers are in a distorted square pyramidal geometry, whereas the DFT optimized structure of complex 2 reveals that two magnesium(II) centers adopt a six-coordinate distorted octahedral geometry. To understand the mode of substrate binding and the mechanistic details of the active site metals in xylose/glucose isomerases (XGI), we have investigated the binding interactions of biologically important monosaccharides d-glucose and d-xylose with complexes 1 and 2, in aqueous alkaline solution by a combined approach of FTIR, UV-vis, fluorescence, and (13)C NMR spectroscopic techniques. Fluorescence spectra show the binding-induced gradual decrease in emission of complexes 1 and 2 accompanied by a significant blue shift upon increasing the concentration of sugar substrates. The binding modes of d-glucose and d-xylose with complex 2 are indicated by their characteristic coordination induced shift (CIS) values in (13)C NMR spectra for C1 and C2 carbon atoms. Copyright © 2013 Elsevier Ltd. All rights reserved.

The effect of losartan and carvedilol on vasopressor responses to adrenergic agonists and angiotensin II in the systemic circulation of Sprague Dawley rats.

PubMed

Abdulla, M H; Sattar, M A; Abdullah, N A; Khan, M A H; Anand Swarup, K R L; Johns, E J

2011-01-01

1 Interaction between renin-angiotensin (RAS) and sympathetic nervous systems (SNS) was investigated by examining the effect of cumulative blockade of angiotensin II (Ang II) and adrenergic receptors in normal Sprague Dawley rats. 2 Rats were treated with losartan (10 mg/kg), carvedilol (5 mg/kg), or losartan plus carvedilol (10+5 mg/kg) orally for 7 days. On day 8, the animals were anaesthetized with pentobarbitone and prepared for systemic haemodynamic study. Dose-response relationships for the elevation of mean arterial pressure or change in heart rate (HR) in response to intravenous injections of noradrenaline (NA), phenylephrine (PE), methoxamine (ME) and Ang II were determined. 3 Losartan or the combination of losartan with carvedilol blunted vasopressor responses to ME and Ang II. Dose-response relationships for agonist action on HR were significantly inhibited by all treatments except for the combination of losartan and carvedilol on the decrease in HR induced by PE. Carvedilol decreased vasopressor responses to NA, PE and Ang II, and HR responses to NA, ME and Ang II. Combination treatment produced similar effects to losartan on the vasopressor and HR responses but had a greater effect on vasopressor responses to ME and Ang II, and on HR responses to NA and Ang II than carvedilol alone. 4 It is concluded that peripheral vasoconstriction induced by Ang II is partly mediated by adrenergic action and that the vasopressor responses to adrenergic agonists depend on an intact RAS. These observations suggest an interactive relationship between RAS and SNS in determining systemic haemodynamic responses in 'normal' rats. © 2010 Blackwell Publishing Ltd.

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.

In silico prediction of ROCK II inhibitors by different classification approaches.

PubMed

Cai, Chuipu; Wu, Qihui; Luo, Yunxia; Ma, Huili; Shen, Jiangang; Zhang, Yongbin; Yang, Lei; Chen, Yunbo; Wen, Zehuai; Wang, Qi

2017-11-01

ROCK II is an important pharmacological target linked to central nervous system disorders such as Alzheimer's disease. The purpose of this research is to generate ROCK II inhibitor prediction models by machine learning approaches. Firstly, four sets of descriptors were calculated with MOE 2010 and PaDEL-Descriptor, and optimized by F-score and linear forward selection methods. In addition, four classification algorithms were used to initially build 16 classifiers with k-nearest neighbors [Formula: see text], naïve Bayes, Random forest, and support vector machine. Furthermore, three sets of structural fingerprint descriptors were introduced to enhance the predictive capacity of classifiers, which were assessed with fivefold cross-validation, test set validation and external test set validation. The best two models, MFK + MACCS and MLR + SubFP, have both MCC values of 0.925 for external test set. After that, a privileged substructure analysis was performed to reveal common chemical features of ROCK II inhibitors. Finally, binding modes were analyzed to identify relationships between molecular descriptors and activity, while main interactions were revealed by comparing the docking interaction of the most potent and the weakest ROCK II inhibitors. To the best of our knowledge, this is the first report on ROCK II inhibitors utilizing machine learning approaches that provides a new method for discovering novel ROCK II inhibitors.

Synthesis, spectroscopy, and binding constants of ketocatechol-containing iminodiacetic acid and its Fe(III), Cu(II), and Zn(II) complexes and reaction of Cu(II) complex with H₂O₂ in aqueous solution.

PubMed

Gao, Jiaojiao; Xing, Feifei; Bai, Yueling; Zhu, Shourong

2014-06-07

A new neuromelanin-like ketocatechol-containing iminodiacetic acid ligand, (N-(3,4-dihydroxyl)phenacylimino)diacetic acid (H4L), which is also quite similar to compounds found in insect cuticle, has been synthesized and characterized. The X-ray crystal structure of H4L has been successfully determined. Proton binding and coordination with Fe(III), Cu(II), and Zn(II) have been studied by potentiometric titrations and UV-vis spectrophotometry in aqueous solution. UV spectra of H4L in the absence and presence of different metal ions indicate complexes formed with the catechol moiety of H4L in aqueous solution. Visible spectra and NMR reveal that H4L with Fe(III), Cu(II), and Zn(II) can all give stable mono-(ML) and dinuclear complexes [M(ML)]. Fe(III) can also form {Fe(FeL)2} and {Fe(FeL)3} species with sufficient base. The process is accompanied by a drastic color change from light blue to deep-blue to wine-red. The Fe(III)-Cu(II) heteronuclear complex also exists in aqueous solution whose spectra are similar to the homonuclear Fe(III) complex. However, the spectra of {Fe(CuL)} shifted to a longer wavelength and {Fe(CuL)2} and {Fe(CuL)3} shifted to a shorter wavelength. Keto-enol tautomerism was observed in weak basic aqueous solution as indicated by (1)H NMR spectra. The reaction products of Cu(II) complex with H2O2 depend on the H2O2 concentration and pH value. Low concentrations of H2O2 oxidize H4L to a series of semiquinone and quinone compounds with absorption maxima at 314-400 nm, while a high concentration of H2O2 oxidizes H4L to colorless muconic acid derivatives. NaIO4 gives different oxidase products, but no 2,4,5-trihydroxyphenylalanine quinone (TPQ)-like hydroxyquinone can be found.

The Co(II), Ni(II) and Cu(II) complexes with herbicide 2,4-dichlorophenoxyacetic acid - Synthesis and structural studies

NASA Astrophysics Data System (ADS)

Drzewiecka-Antonik, Aleksandra; Ferenc, Wiesława; Wolska, Anna; Klepka, Marcin T.; Cristóvão, Beata; Sarzyński, Jan; Rejmak, Paweł; Osypiuk, Dariusz

2017-01-01

The Co(II), Ni(II) and Cu(II) complexes with herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) were synthesized and structurally characterized. The geometry of metal-ligand interaction was refined using XAFS and DFT studies. The Co(2,4-D)2·6H2O and Ni(2,4-D)2·4H2O complexes have octahedral geometry with two carboxylate groups of 2,4-D anions and four water molecules in the coordination sphere. The square planar geometry around metal cations formed by the carboxylate groups from two monodentate ligands and two water molecules, is observed for Cu(2,4-D)2·4H2O complex. In the recrystallized Ni(II) complex dinuclear 'Chinese lantern' structures with bridging carboxylate groups of 2,4-D were observed.

[Heparin-induced thrombocytopenia type II (HIT II) : A medical-economic view].

PubMed

Riedel, R; Schmieder, A; Koster, A; Kim, S; Baumgarten, G; Schewe, J C

2017-05-01

In the context of inpatient and increasingly ambulatory thrombosis prophylaxis, heparins have been recognised as standard therapy for decades. In addition to the therapeutic benefit, therapy with heparins also entails the risk of undesirable side effects, such as bleeding and thrombocytopenia. Heparin-induced thrombocytopenia (HIT II) is deemed a serious side effect. In the following work, HIT II is subjected to a medico-economic consideration (treatment, pharmaceuticals, subsequent costs due to possible complications) and, with regard to a possible HIT II prophylaxis, aspects of increasingly respected patient safety are also considered. In the context of a literature search the active ingredients argatroban and danaparoid, which are approved for HIT II treatment, were evaluated. HIT II - especially in combination with thromboembolic complications - represents a medical-economic burden for the hospital. Although this is only an orientation guide, it shows that HIT II syndrome is not adequately cost-covered by the G‑DRG system. An early thrombosis prophylaxis with argatroban/danaparoid for HIT II risk patients should therefore be taken into account for medical-related as well as patient safety-relevant aspects. According to experience, the pharmaceutical supply for these medically needed products (anticoagulants) should be ensured for reasons of patient safety. The risk of an immunological response to heparin therapy is known. Within the context of increased patient safety, thrombosis prophylaxis should be issued with a risk-adjusted prophylaxis.

Oral administration of undenatured native chicken type II collagen (UC-II) diminished deterioration of articular cartilage in a rat model of osteoarthritis (OA).

PubMed

Bagi, C M; Berryman, E R; Teo, S; Lane, N E

2017-12-01

The aim of this study was to determine the ability of undenatured native chicken type II collagen (UC-II) to prevent excessive articular cartilage deterioration in a rat model of osteoarthritis (OA). Twenty male rats were subjected to partial medial meniscectomy tear (PMMT) surgery to induce OA. Immediately after the surgery 10 rats received vehicle and another 10 rats oral daily dose of UC-II at 0.66 mg/kg for a period of 8 weeks. In addition 10 naïve rats were used as an intact control and another 10 rats received sham surgery. Study endpoints included a weight-bearing capacity of front and hind legs, serum biomarkers of bone and cartilage metabolism, analyses of subchondral and cancellous bone at the tibial epiphysis and metaphysis, and cartilage pathology at the medial tibial plateau using histological methods. PMMT surgery produced moderate OA at the medial tibial plateau. Specifically, the deterioration of articular cartilage negatively impacted the weight bearing capacity of the operated limb. Immediate treatment with the UC-II preserved the weight-bearing capacity of the injured leg, preserved integrity of the cancellous bone at tibial metaphysis and limited the excessive osteophyte formation and deterioration of articular cartilage. Study results demonstrate that a clinically relevant daily dose of UC-II when applied immediately after injury can improve the mechanical function of the injured knee and prevent excessive deterioration of articular cartilage. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Oxidation of Structural Fe(II) in Biotite by Lithotrophic Fe(II)-oxidizing microorganisms

NASA Astrophysics Data System (ADS)

Shelobolina, E.; Blöthe, M.; Xu, H.; Konishi, H.; Roden, E.

2008-12-01

The potential for microbial involvement in the oxidation of Fe(II)-bearing phyllosilicates is an understudied aspect of soil/sediment Fe biogeochemistry. An important property of structural Fe in Fe-bearing smectites is their ability to undergo multiple redox cycles without being mobilized. An obvious choice of mineral substrate for enumeration/isolation of Fe(II)-oxidizing microorganisms would be reduced smectite. But reduced smectite is readily oxidized by air. That is why biotite was chosen as a substrate for this study. In contrast to smectite, biotite is more stable in the presence of air, but incapable of redox cycling. Once Fe(II) is oxidized, biotite is weathered to expendable 2:1 phyllosilicates or kaolinite. First, we evaluated the ability of a neutral-pH lithoautotrophic nitrate-reducing enrichment culture (MPI culture), recovered by Straub et al (Appl. Environ. Microbiol., 1996, 62:1458-1460) from a freshwater ditch, to oxidize two different specimens of biotite. The culture was capable of multiple transfers in anaerobic nitrate-containing biotite suspensions. The growth of MPI culture resulted in decrease of 0.5 N HCl-extractable Fe(II) content and simultaneous nitrate reduction. Cell yields were comparable to those observed for other neutral-pH lithoautotrophic Fe(II)-oxidizing bacteria. High resolution TEM examination revealed structural and chemical changes at the edges of oxidized biotite and formation of reddish amorphous precipitates dominated by Si and Fe. To further evaluate efficiency of biotite for recovery of oxygen- and nitrate-dependent Fe(II) oxidizing cultures microbial enumeration study was performed using subsoil from a site near Madison, WI. The soil is rich in Fe-bearing smectite and shows evidence of redoximorphic features. The enumeration of Fe(II) oxidizing organisms from this sediment showed 10-fold higher efficiency of biotite over soluble Fe(II) for recovery of Fe(II)-oxidizers. Isolation and identification of both aerobic and

Psychometric Properties of the Beck Depression Inventory-II (BDI-II) among Community-Dwelling Older Adults

ERIC Educational Resources Information Center

Segal, Daniel L.; Coolidge, Frederick L.; Cahill, Brian S.; O'Riley, Alisa A.

2008-01-01

The psychometric properties of the Beck Depression Inventory-II (BDI-II) as a self-administered screening tool for depressive symptoms were examined in a sample of community-dwelling older and younger adults. Participants completed the BDI-II, the Center for Epidemiologic Studies Depression Scale, the Coolidge Axis II Inventory, the Perceived…

Morphological Properties of Slender Ca II H Fibrils Observed by Sunrise II

NASA Astrophysics Data System (ADS)

Gafeira, R.; Lagg, A.; Solanki, S. K.; Jafarzadeh, S.; van Noort, M.; Barthol, P.; Blanco Rodríguez, J.; del Toro Iniesta, J. C.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Knölker, M.; Orozco Suárez, D.; Riethmüller, T. L.; Schmidt, W.

2017-03-01

We use seeing-free high spatial resolution Ca II H data obtained by the Sunrise observatory to determine properties of slender fibrils in the lower solar chromosphere. In this work we use intensity images taken with the SuFI instrument in the Ca II H line during the second scientific flight of the Sunrise observatory to identify and track elongated bright structures. After identification, we analyze theses structures to extract their morphological properties. We identify 598 slender Ca II H fibrils (SCFs) with an average width of around 180 km, length between 500 and 4000 km, average lifetime of ≈400 s, and average curvature of 0.002 arcsec-1. The maximum lifetime of the SCFs within our time series of 57 minutes is ≈2000 s. We discuss similarities and differences of the SCFs with other small-scale, chromospheric structures such as spicules of type I and II, or Ca II K fibrils.

Collecting duct prorenin receptor knockout reduces renal function, increases sodium excretion, and mitigates renal responses in ANG II-induced hypertensive mice.

PubMed

Prieto, Minolfa C; Reverte, Virginia; Mamenko, Mykola; Kuczeriszka, Marta; Veiras, Luciana C; Rosales, Carla B; McLellan, Matthew; Gentile, Oliver; Jensen, V Behrana; Ichihara, Atsuhiro; McDonough, Alicia A; Pochynyuk, Oleh M; Gonzalez, Alexis A

2017-12-01

Augmented intratubular angiotensin (ANG) II is a key determinant of enhanced distal Na + reabsorption via activation of epithelial Na + channels (ENaC) and other transporters, which leads to the development of high blood pressure (BP). In ANG II-induced hypertension, there is increased expression of the prorenin receptor (PRR) in the collecting duct (CD), which has been implicated in the stimulation of the sodium transporters and resultant hypertension. The impact of PRR deletion along the nephron on BP regulation and Na + handling remains controversial. In the present study, we investigate the role of PRR in the regulation of renal function and BP by using a mouse model with specific deletion of PRR in the CD ( CD PRR-KO). At basal conditions, CD PRR-KO mice had decreased renal function and lower systolic BP associated with higher fractional Na + excretion and lower ANG II levels in urine. After 14 days of ANG II infusion (400 ng·kg -1 ·min -1 ), the increases in systolic BP and diastolic BP were mitigated in CD PRR-KO mice. CD PRR-KO mice had lower abundance of cleaved αENaC and γENaC, as well as lower ANG II and renin content in urine compared with wild-type mice. In isolated CD from CD PRR-KO mice, patch-clamp studies demonstrated that ANG II-dependent stimulation of ENaC activity was reduced because of fewer active channels and lower open probability. These data indicate that CD PRR contributes to renal function and BP responses during chronic ANG II infusion by enhancing renin activity, increasing ANG II, and activating ENaC in the distal nephron segments. Copyright © 2017 the American Physiological Society.

Ligational behaviour of lomefloxacin drug towards Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Th(IV) and UO(2)(VI) ions: synthesis, structural characterization and biological activity studies.

PubMed

Abd el-Halim, Hanan F; Mohamed, Gehad G; el-Dessouky, Maher M I; Mahmoud, Walaa H

2011-11-01

Nine new mononuclear Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Th(IV) and UO(2)(VI) complexes of lomefloxacin drug were synthesized. The structures of these complexes were elucidated by elemental analyses, IR, XRD, UV-vis, (1)H NMR as well as conductivity and magnetic susceptibility measurements and thermal analyses. The dissociation constants of lomefloxacin and stability constants of its binary complexes have been determined spectrophotometrically in aqueous solution at 25±1°C and at 0.1 M KNO(3) ionic strength. The discussion of the outcome data of the prepared complexes indicate that the lomefloxacin ligand behaves as a neutral bidentate ligand through OO coordination sites and coordinated to the metal ions via the carbonyl oxygen and protonated carboxylic oxygen with 1:1 (metal:ligand) stoichiometry for all complexes. The molar conductance measurements proved that the complexes are electrolytes. The powder XRD study reflects the crystalline nature for the investigated ligand and its complexes except Mn(II), Zn(II) and UO(2)(II). The geometrical structures of these complexes are found to be octahedral. The thermal behaviour of these chelates is studied where the hydrated complexes lose water molecules of hydration in the first steps followed by decomposition of the anions, coordinated water and ligand molecules in the subsequent steps. The activation thermodynamic parameters are calculated using Coats-Redfern and Horowitz-Metzger methods. A comparative study of the inhibition zones of the ligand and its metal complexes indicates that metal complexes exhibit higher antibacterial effect against one or more bacterial species than the free LFX ligand. The antifungal and anticancer activities were also tested. The antifungal effect of almost metal complexes is higher than the free ligand. LFX, [Co(LFX)(H(2)O)(4)]·Cl(2) and [Zn(LFX)(H(2)O)(4)]·Cl(2) were found to be very active with IC50 values 14, 11.2 and 43.1, respectively. While, other

Synthesis, characterization, antimicrobial activity and DFT studies of 2-(pyrimidin-2-ylamino)naphthalene-1,4-dione and its Mn(II), Co(II), Ni(II) and Zn(II) complexes

NASA Astrophysics Data System (ADS)

Chioma, Festus; Ekennia, Anthony C.; Ibeji, Collins U.; Okafor, Sunday N.; Onwudiwe, Damian C.; Osowole, Aderoju A.; Ujam, Oguejiofo T.

2018-07-01

A pyrimidine-based ligand, 2-(pyrimidin-2-ylamino)naphthalene-1,4-dione (L), has been synthesized by the reaction of 2-aminopyrimidine with 2-hydroxy-1,4-napthoquinone. Reaction of the ligand with Ni(II), Co(II), Mn(II) and Zn(II) acetate gave the corresponding metal complexes which were characterized by spectroscopic techniques, (infrared, electronic), elemental analysis, room-temperature magnetometry, conductance measurements and thermogravimetry-differential scanning calorimetry (TG-DSC) analyses. The room-temperature magnetic data and electronic spectral measurements of the complexes gave evidence of 4-coordinate square planar/tetrahedral geometry. The thermal analyses values obtained indicated the monohydrate complexes. The antimicrobial screening of the compounds showed mild to very good results. The Mn(II) complex showed the best result within in the range of 11.5-29 mm. The electronic, structural and spectroscopic properties of the complexes were further discussed using density functional theory. Molecular docking studies showed significant binding affinity with the drug targets and the metal complexes have potentials to be used as drugs.

Blood pressure, magnesium and other mineral balance in two rat models of salt-sensitive, induced hypertension: effects of a non-peptide angiotensin II receptor type 1 antagonist.

PubMed

Rondón, Lusliany Josefina; Marcano, Eunice; Rodríguez, Fátima; del Castillo, Jesús Rafael

2014-01-01

The renin-angiotensin system is critically involved in regulating arterial blood pressure (BP). Inappropriate angiotensin type-1 receptor activation by angiotensin-II (Ang-II) is related to increased arterial BP. Mg has a role in BP; it can affect cardiac electrical activity, myocardial contractility, and vascular tone. To evaluate the relationship between high BP induced by a high sodium (Na) diet and Mg, and other mineral balances, two experimental rat models of salt-sensitive, induced-hypertension were used: Ang-II infused and Dahl salt-sensitive (SS) rats. We found that: 1) Ang-II infusion progressively increased BP, which was accompanied by hypomagnesuria and signs of secondary hyperaldosteronism; 2) an additive effect between Ang-II and a high Na load may have an effect on strontium (Sr), zinc (Zn) and copper (Cu) balances; 3) Dahl SS rats fed a high Na diet had a slow pressor response, accompanied by altered Mg, Na, potassium (K), and phosphate (P) balances; and 4) losartan prevented BP increases induced by Ang II-NaCl, but did not modify mineral balances. In Dahl SS rats, losartan attenuated high BP and ameliorated magnesemia, Na and K balances. Mg metabolism maybe considered a possible defect in this strain of rat that may contribute to hypertension.

Adsorption of Cd(II) and Pb(II) by in situ oxidized Fe3O4 membrane grafted on 316L porous stainless steel filter tube and its potential application for drinking water treatment.

PubMed

Zhu, Mengfei; Zhu, Li; Wang, Jianlong; Yue, Tianli; Li, Ronghua; Li, Zhonghong

2017-07-01

Removing heavy metal ions from aqueous solutions is one of the most challenging separations. In situ oxidized Fe 3 O 4 membranes using 316L porous stainless steel filter tube have shown great potential for removing anion Cr(VI). Here we report the performances of the in situ oxidized Fe 3 O 4 membranes for removing two toxic cations Cd(II) and Pb(II) commonly existing in water and their potential applications for drinking water purification. The membranes exhibited high removal efficiency: 97% at pH 9.0 for Cd(II) of 1.0 mg/L initial concentration and 100% at pH 5.0-6.0 for Pb(II) of 5.0 mg/L initial concentration. The maximum adsorption capabilities were estimated at 0.800 mg/g and 2.251 mg/g respectively for Cd(II) and Pb(II) at 318 K by the Langmuir model. Results of batch tests revealed the existence of electrostatic attraction and chemisorption. XRD and FT-IR analyses indicated that the chemisorption might be the insertion of Cd(II) and Pb(II) into the Fe 3 O 4 crystal faces of 311 and 511 to form mononuclear or binuclear coordination with O atoms of Fe-O 6 groups. Competitive adsorption of Cd(II) and Pb(II) in binary solutions revealed a preferential adsorption for Pb(II). Na 2 EDTA solution was used to regenerate the membranes, and the maximum desorption ratio was 90.29% and 99.75% respectively for Cd(II) and Pb(II). The membranes were able to efficiently lower Cd(II) and Pb(II) concentrations to meet the drinking water standards recommended by the World Health Organization and are promising for engineering applications aimed at drinking water purification. Copyright © 2017 Elsevier Ltd. All rights reserved.

TAF(II)250: a transcription toolbox.

PubMed

Wassarman, D A; Sauer, F

2001-08-01

Activation of RNA-polymerase-II-dependent transcription involves conversion of signals provided by gene-specific activator proteins into the synthesis of messenger RNA. This conversion requires dynamic structural changes in chromatin and assembly of general transcription factors (GTFs) and RNA polymerase II at core promoter sequence elements surrounding the transcription start site of genes. One hallmark of transcriptional activation is the interaction of DNA-bound activators with coactivators such as the TATA-box binding protein (TBP)-associated factors (TAF(II)s) within the GTF TFIID. TAF(II)250 possesses a variety of activities that are likely to contribute to the initial steps of RNA polymerase II transcription. TAF(II)250 is a scaffold for assembly of other TAF(II)s and TBP into TFIID, TAF(II)250 binds activators to recruit TFIID to particular promoters, TAF(II)250 regulates binding of TBP to DNA, TAF(II)250 binds core promoter initiator elements, TAF(II)250 binds acetylated lysine residues in core histones, and TAF(II)250 possesses protein kinase, ubiquitin-activating/conjugating and acetylase activities that modify histones and GTFs. We speculate that these activities achieve two goals--(1) they aid in positioning and stabilizing TFIID at particular promoters, and (2) they alter chromatin structure at the promoter to allow assembly of GTFs--and we propose a model for how TAF(II)250 converts activation signals into active transcription.

Efficacy and safety of glycosylated undenatured type-II collagen (UC-II) in therapy of arthritic dogs.

PubMed

Deparle, L A; Gupta, R C; Canerdy, T D; Goad, J T; D'Altilio, M; Bagchi, M; Bagchi, D

2005-08-01

DeParle L. A., Gupta R. C., Canerdy T. D., Goad J. T., D'Altilio M., Bagchi M., Bagchi D. Efficacy and safety of glycosylated undenatured type-II collagen (UC-II) in therapy of arthritic dogs. J. vet. Pharmacol. Therap.28, 385-390. In large breed dogs, arthritis is very common because of obesity, injury, aging, immune disorder, or genetic predispositions. This study was therefore undertaken to evaluate clinical efficacy and safety of undenatured type-II collagen (UC-II) in obese-arthritic dogs. Fifteen dogs in three groups received either no UC-II (Group I) or UC-II with 1 mg/day (Group II) or 10 mg/day (Group III) for 90 days. Lameness and pain were measured on a weekly basis for 120 days (90 days treatment plus 30 days post-treatment). Blood samples were assayed for creatinine and blood urea nitrogen (markers of renal injury); and alanine aminotransferase and aspartate aminotransferase (evidence of hepatic injury). Dogs receiving 1 mg or 10 mg UC-II/day for 90 days showed significant declines in overall pain and pain during limb manipulation and lameness after physical exertion, with 10 mg showed greater improvement. At either dose of UC-II, no adverse effects were noted and no significant changes were noted in serum chemistry, suggesting that UC-II was well tolerated. In addition, dogs receiving UC-II for 90 days showed increased physical activity level. Following UC-II withdrawal for a period of 30 days, all dogs experienced a relapse of overall pain, exercise-associated lameness, and pain upon limb manipulation. These results suggest that daily treatment of arthritic dogs with UC-II ameliorates signs and symptoms of arthritis, and UC-II is well tolerated as no adverse effects were noted.

Synthesis, characterization and in vitro antimicrobial studies of Co(II), Ni(II) and Cu(II) complexes derived from macrocyclic compartmental ligand

NASA Astrophysics Data System (ADS)

El-Gammal, O. A.; Bekheit, M. M.; El-Brashy, S. A.

2015-02-01

New Co(II), Ni(II) and Cu(II) complexes derived from tetradentate macrocyclic nitrogen ligand, (1E,4E,8E,12E)-5,8,13,16-tetramethyl-1,4,9,12-tetrazacyclohexadeca-4,8,12,16-tetraene (EDHDH) have been synthesized. The complexes have been characterized by elemental analysis, spectral (IR, UV-Vis, 1H NMR and ESR (for Cu(II) complex)) mass, and magnetic as well as thermal analysis measurements. The complexes afforded the formulae: [Cu(EDHDH)Cl2]·2EtOH and [M(EDHDH)X2]·nH2O where M = Co(II) and Ni(II), X = Cl- or OH-, n = 1,0, respectively. The data revealed an octahedral arrangement with N4 tetradentate donor sites in addition to two Cl atoms occupying the other two sites. ESR spectrum of Cu2+ complex confirmed the suggested geometry with values of a α2and β2 indicating that the in-plane σ-bonding and in-plane π-bonding are appreciably covalent, and are consistent with very strong σ-in-plane bonding in the complexes. The molecular modeling is drawn and showed the bond length, bond angle, chemical reactivity, energy components (kcal/mol) and binding energy (kcal/mol) for all the title compounds using DFT method. Also, the thermal behavior and the kinetic parameters of degradation were determined using Coats-Redfern and Horowitz-Metzger methods. Moreover, the in vitro antibacterial studies of all compounds screened against pathogenic bacteria (two Gram +ve and two Gram -ve) to assess their inhibiting potential. The assay indicated that the inhibition potential is metal ion dependent. The ligand, EDHDH, Co(II) and Cu(II) complexes exhibited a remarkable antibacterial activity against Streptococcus Pyogenes as Gram +ve and Proteus vulgaris as Gram -ve bacterial strains. On the other hand, Ni(II) complex revealed a moderate antibacterial activity against both Gram +ve organisms and no activity against Gram -ve bacterial strain.

Broad [C II] Line Wings as Tracer of Molecular and Multi-phase Outflows in Infrared Bright Galaxies

NASA Astrophysics Data System (ADS)

Janssen, A. W.; Christopher, N.; Sturm, E.; Veilleux, S.; Contursi, A.; González-Alfonso, E.; Fischer, J.; Davies, R.; Verma, A.; Graciá-Carpio, J.; Genzel, R.; Lutz, D.; Sternberg, A.; Tacconi, L.; Burtscher, L.; Poglitsch, A.

2016-05-01

We report a tentative correlation between the outflow characteristics derived from OH absorption at 119 μm and [C II] emission at 158 μm in a sample of 22 local and bright ultraluminous infrared galaxies (ULIRGs). For this sample, we investigate whether [C II] broad wings are a good tracer of molecular outflows, and how the two tracers are connected. Fourteen objects in our sample have a broad wing component as traced by [C II], and all of these also show OH119 absorption indicative of an outflow (in one case an inflow). The other eight cases, where no broad [C II] component was found, are predominantly objects with no OH outflow or a low-velocity (≤100 km s-1) OH outflow. The FWHM of the broad [C II] component shows a trend with the OH119 blueshifted velocity, although with significant scatter. Moreover, and despite large uncertainties, the outflow masses derived from OH and broad [C II] show a 1:1 relation. The main conclusion is therefore that broad [C II] wings can be used to trace molecular outflows. This may be particularly relevant at high redshift, where the usual tracers of molecular gas (like low-J CO lines) become hard to observe. Additionally, observations of blueshifted Na I D λλ 5890, 5896 absorption are available for 10 of our sources. Outflow velocities of Na I D show a trend with OH velocity and broad [C II] FWHM. These observations suggest that the atomic and molecular gas phases of the outflow are connected.

Dipeptidyl peptidase-II from probiotic Pediococcus acidilactici: Purification and functional characterization.

PubMed

Gandhi, Dimpi; Chanalia, Preeti; Attri, Pooja; Dhanda, Suman

2016-12-01

Dipeptidylpeptidase-II (DPP-II, E.C. 3.4.14.2), an exopeptidase was purified 15.4 fold with specific activity and yield of 15.4U/mg/mL and 14.68% respectively by a simple two step procedure from a probiotic Pediococcus acidilactici. DPP-II is 38.7KDa homodimeric serine peptidase with involvement of His and subunit mass of 18.9KDa. The enzyme exhibited optimal activity at pH 7.0 and 37°C with activation energy of 24.97kJ/mol. The enzyme retained more than 90% activity upto 50°C thus adding industrial importance. DPP-II hydrolysed Lys-Ala-4mβNA with K M of 50μM and V max of 30.8nmol/mL/min. In-silico characterization studies of DPP-II on the basis of peptide fragments obtained by MALDI-TOF revealed an evolutionary relationship between DPP-II of prokaryotes and phosphate binding proteins. Secondary and three-dimensional structure of enzyme was also deduced by in-silico approach. Functional studies of DPP-II by TLC and HPLC-analysis of collagen degraded products revealed that enzyme action released free amino acids and other metabolites. Microscopic and SDS-PAGE analysis of enzyme treated analysis of chicken's chest muscle (meat) hydrolysis revealed change and hydrolysis of myofibrils. This may affect the flavor and texture of meat thereby suggesting its role in meat tenderization. Being a protein of LAB (Lactic acid bacteria), it is also expected to be safe. Copyright © 2016 Elsevier B.V. All rights reserved.

Kinetics and thermodynamics of Pb(II) adsorption onto modified spent grain from aqueous solutions

NASA Astrophysics Data System (ADS)

Li, Qingzhu; Chai, Liyuan; Yang, Zhihui; Wang, Qingwei

2009-01-01

Spent grain, a main by-product of the brewing industry, is available in large quantities, but its main application has been limited to animal feeding. Nevertheless, in this study, spent grain modified with 1 M NaCl solution as a novel adsorbent has been used for the adsorption of Pb(II) in aqueous solutions. Isotherms, kinetics and thermodynamics of Pb(II) adsorption onto modified spent grain were studied. The equilibrium data were well fitted with Langmuir, Freundlich and Dubinin-Radushkevick (D-R) isotherm models. The kinetics of Pb(II) adsorption followed pseudo-second-order model, using the rate constants of pseudo-second-order model, the activation energy ( Ea) of Pb(II) adsorption was determined as 12.33 kJ mol -1 according to the Arrhenius equation. Various thermodynamic parameters such as Δ Gads, Δ Hads and Δ Sads were also calculated. Thermodynamic results indicate that Pb(II) adsorption onto modified spent grain is a spontaneous and endothermic process. Therefore, it can be concluded that modified spent grain as a new effective adsorbent has potential for Pb(II) removal from aqueous solutions.

Combinatorial screening of potentiometric Pb(II) sensors from polysulfoaminoanthraquinone solid ionophore.

PubMed

Huang, Mei-Rong; Ding, Yong-Bo; Li, Xin-Gui

2014-03-10

A potentiometric Pb(II)-selective sensor was fabricated by a combinatorial screening of electrically conducting polysulfoaminoanthraquinone (PSA) nanoparticles as a solid ionophore, ion exchangers (oleic acid (OA) and NaTPB), plasticizers in a polyvinyl chloride (PVC) matrix, membrane thickness, inner filling ion species, and concentration. The membrane sensor with the composition of PSA/PVC/DOP (dioctyl phthalate)/OA (1.0:33:61:5.0) exhibited the best performance, including a slope of 29.3 mV decade(-1) in the concentration range 10(-6.3)-10(-1.6) M, detection limit of 1.6 × 10(-7) M, response time of 16 s, lifetime of five months, and good response reversibility. The proposed sensor has demonstrated good selectivity for Pb(II) over other monovalent, divalent and trivalent interfering ions, and could be used in a pH range of 3.62-5.22. The Pb(II) sensor has been successfully applied for the determination of Pb(II) concentration in real-world samples and also as an indicator electrode for potentiometric titration of lead ions.

Nano modification of NZVI with an aquatic plant Azolla filiculoides to remove Pb(II) and Hg(II) from water: Aging time and mechanism study.

PubMed

Arshadi, M; Abdolmaleki, M K; Mousavinia, F; Foroughifard, S; Karimzadeh, A

2017-01-15

This paper reports the preparation and stabilization of nano zero valent iron (NZVI) on a modified aquatic plant, Azolla filiculoides, and investigates its potential for the adsorption/reduction of Pb(II) and Hg(II) ions from aqueous media even after six months of storage in the lab condition. XRD, TEM and zeta potential results demonstrated that the Azolla-NaOH could be a good stabilizer of aged NZVI (six months) and the green support suppressed the oxidation and aggregation of immobilized NZVI. Kinetic and equilibrium models for lead and mercury ions uptake were developed by considering the effect of the initial Pb(II) and Hg(II) concentrations, contact time, adsorbent dosage, initial pH and effect of temperature. The contact time to obtain equilibrium for maximum uptake by Azolla-OH-NZVI was 20min. The removal of toxic metal ions has been monitored in terms of pseudo-first- and -second-order kinetics, and the Freundlich and Langmuir isotherms models have also been utilized to the equilibrium uptake results. The uptake kinetics followed the mechanism of the pseudo-second-order equation for all systems studied, confirming chemical sorption as the rate-limiting step of adsorption mechanisms and not involving a mass transfer in solution. The thermodynamic results confirmed that the uptake of Pb(II) and Hg(II) ions were feasible, spontaneous and endothermic at 25-80°C. XRD and zeta potential data displayed the existence of Pb(0) and Hg(0) on the Azolla-OH-NZVI surface. The nanobioadsorbent revealed high recyclability due to its reasonable uptake efficiency after 7th adsorption-desorption cycles. The proposed nano biocomposite could also be utilized to uptake Pb(II) and Hg(II) ions from the real water (Anzali lagoon water). However, coated NZVI with Azolla filiculoides as a green and environmentally friendly support suppressed rapid oxidation and aggregation of the immobilized NZVI, therefore vastly enhancing the probability of environmental transport and reducing

Oxidative removal of Mn(II) from solution catalysed by the γ-FeOOH (lepidocrocite) surface

NASA Astrophysics Data System (ADS)

Sung, Windsor; Morgan, James J.

1981-12-01

A laboratory study was undertaken to ascertain the role of surface catalysis in Mn(II) oxidative removal. γ-FeOOH, a ferric oxyhydroxide formed by O2 oxidation of ferrous iron in solution, was studied in the following ways: surface charge characteristics by acid base titration, adsorption of Mn(II) and surface oxidation of Mn(II). A rate law was formulated to account for the effects of pH and the amount of surface on the surface oxidation rate of Mn(II). The presence of milli-molar levels of γ-FeOOH was shown to reduce significantly the half-life of Mn(II) in 0.7 M NaCl from hundreds of hours to hours. The numerical values of the surface rate constants for the γ-FeOOH and that reported for colloidal MnO2 are comparable in order of magnitude.

Effect of pioglitazone on vasopressor responses to adrenergic agonists and angiotensin II in diabetic and non-diabetic spontaneously hypertensive rats.

PubMed

Afzal, Sheryar; Sattar, Munavvar Abdul; Akhtar, Safia; Binti Abdullah, Nor Azizan; Eseyin, Olorunfemi A; Abdulla, Mohammed H; Johns, Edward James

2018-05-01

Pioglitazone, peroxisome proliferator-activated receptor (PPAR-γ) agonist, is a therapeutic drug for diabetes. Present study investigated the interaction between PPAR-γ and alpha adrenoceptors in modulating vasopressor responses to Angiotensin II (Ang II) and adrenergic agonists, in diabetic & non-diabetic Spontaneously Hypertensive Rats (SHRs). Diabetes was induced with an i.p injection of streptozotocin (40 mg/kg) in two groups (STZ-CON, STZ-PIO), whereas two groups remained non diabetic (ND-CO, ND-PIO). One diabetic and non-diabetic group received Pioglitazone (10mg/kg) orally for 21 days. On day 28, the animals were anaesthetized with sodium pentobarbitone (60mg/kg) and prepared for measurement of systemic haemodynamics. Basal mean arterial pressure of STZ-CON was higher than ND-CON, whereas following pioglitazone treatment, MAP was lower compared to respective controls. MAP responses to i.v administration of NA, PE, ME and ANG II were significantly lower in diabetic SHRs: STZ-CON vs ND-CON (35%). Pioglitazone significantly decreased responses to NA, PE, ME and ANG II in ND-PIO versus ND-CON by 63%. Responses to NA and ANG II were significantly attenuated in STZ-PIO vs. ND-PIO (40%). PPAR-γ regulates systemic hemodynamic in diabetic model and cross-talk relationship exists between PPAR-γ and α1-adrenoceptors, ANG II in systemic vasculature of SHRs.

Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation.

PubMed

Lekowski, R; Collard, C D; Reenstra, W R; Stahl, G L

2001-02-01

Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O(2), 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 +/- 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (< or = 100 micromol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC(50) = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC(50) approximately 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress.

Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation

PubMed Central

Lekowski, Robert; Collard, Charles D.; Reenstra, Wende R.; Stahl, Gregory L.

2001-01-01

Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O2, 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 ± 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (≤ 100 μmol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC50 = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC50 ≈ 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress. PMID:11266613

Preparation of Palladium(II) Ion-Imprinted Polymeric Nanospheres and Its Removal of Palladium(II) from Aqueous Solution

NASA Astrophysics Data System (ADS)

Tao, Hu-Chun; Gu, Yi-Han; Liu, Wei; Huang, Shuai-Bin; Cheng, Ling; Zhang, Li-Juan; Zhu, Li-Li; Wang, Yong

2017-11-01

Three kinds of functional monomers, 4-vinylpridine(4-VP), 2-(allylthio)nicotinic acid(ANA), and 2-Acetamidoacrylic acid(AAA), were used to synthetize palladium(II) ion-imprinted polymeric nanospheres (Pd(II) IIPs) via precipitation-polymerization method in order to study the effects of different functional monomers on the adsorption properties of ion-imprinted materials. The results of UV spectra in order to study the interaction between template ion PdCl4 2- and functional monomers showed that there were great differences in structure after the template reacted with three functional monomers, 4-VP and ANA caused a large structural change, while AAA basically did not change. Further results on the adsorption performance of Pd(II) IIPs on Pd(II) confirmed 4-VP was the most promising candidate for the synthesis of Pd(II) IIPs with an adsorption capacity of 5.042 mg/g as compared with ANA and AAA. The influence of operating parameters on Pd(II) IIP's performance on Pd(II) adsorption was investigated. There was an increase in the adsorption capacity of Pd(II) IIPs at higher pH, temperature, and initial concentration of Pd(II). The results of multi-metal competitive adsorption experiments showed that Pd(II) IIPs had selectivity for Pd(II). An adsorption equilibrium could be reached at 180 min. Kinetic analysis showed that the adsorption test data fitted best to the pseudo-second order kinetic model, and the theoretical equilibrium adsorption capacity was about 5.085 mg/g. The adsorption isotherms of Pd(II) by Pd(II) IIPs agreed well with the Freundlich equation, suggesting a favorable adsorption reaction under optimal conditions. These results showed that Pd(II) IIPs have potential application in the removal of Pd(II) from aqueous solutions and may provide some information for the selection of functional monomers in the preparation of Pd(II) IIPs.

Patient-related barriers to pain management: the Barriers Questionnaire II (BQ-II).

PubMed

Gunnarsdottir, Sigridur; Donovan, Heidi S; Serlin, Ronald C; Voge, Catherine; Ward, Sandra

2002-10-01

Patients' beliefs can act as barriers to optimal management of cancer pain. The Barriers Questionnaire (BQ) is a tool used to evaluate such barriers. Here, the BQ has been revised to reflect changes in pain management practices, resulting in the Barriers Questionnaire-II (BQ-II), a 27-item, self report instrument. This paper presents the results from two studies where the psychometric properties of the BQ-II were evaluated. In the first study, the responses of 27 nurses trained in pain management were compared to responses of a convenience sample of 12 patients with cancer. The results indicated that patients with cancer had higher mean scores on the BQ-II than did nurses trained in pain management. In the second study, a convenience sample of 172 patients with cancer responded to the BQ-II and a set of pain and quality of life (QOL) measures. A factor analysis supported four factors. Factor one, physiological effects, consists of 12 items addressing the beliefs that side effects of analgesics are inevitable and unmanageable, concerns about tolerance, and concerns about not being able to monitor changes in one's body when taking strong pain medications. Factor two, Fatalism, consists of three items addressing fatalistic beliefs about cancer pain and its management. Factor three, Communication, consists of six items addressing the concern that reports of pain distract the physician from treating the underlying disease, and the belief that 'good' patients do not complain of pain. The fourth and final factor, harmful effects, consists of six items addressing fear of becoming addicted to pain medication and the belief that pain medications harm the immune system. The BQ-II total had an internal consistency of 0.89, and alpha for the subscales ranged from 0.75 to 0.85. Mean (SD) scores on the total scale was 1.52 (0.73). BQ-II scores were related to measures of pain intensity and duration, mood, and QOL. Patients who used adequate analgesics for their levels of pain had

Angiotensin II-mediated microvascular thrombosis

PubMed Central

Senchenkova, Elena Y.; Russell, Janice; Almeida-Paula, Lidiana D.; Harding, Joseph W.; Granger, D. Neil

2010-01-01

Hypertension is associated with an increased risk of thrombosis that appears to involve an interaction between the renin-angiotensin system and hemostasis. In this study we determined whether angiotensin II-mediatedthrombosis occurs in arterioles and/or venules, and assessed the involvement of type-1 (AT1), type-2 (AT2) and type 4 (AT4) angiotensin II receptors, as well as receptors for endothelin-1 (ET-1) and bradykinin (BK-1, BK-2) in angiotensin II-enhanced microvascular thrombosis. Thrombus development in mouse cremaster microvessels was quantified after light/dye injury using the time of onset of the thrombus and time to blood flow cessation. Wild type and AT1-receptor deficient mice were implanted with an angiotensin II-loaded Alzet pump for 2 wks. Angiotensin II administration in both wild type and AT1-receptor deficient mice significantly accelerated thrombosis in arterioles. Genetic deficiency and pharmacological antagonism of AT1-receptors did not alter the thrombosis response to angiotensin II. Isolated murine platelets aggregated in response to low (pM), but not high (nM), concentrations of angiotensin II. The platelet aggregation response to angiotensin II was dependent on AT1-receptors. Antagonism of AT2-receptors in vivo significantly prolonged the onset of angiotensin II enhanced thrombosis, while an AT4-receptor antagonist prolonged the time to flow cessation. Selective antagonism of either ET-1 or BK-1 receptors largely prevented both the onset and flow cessation responses to chronic angiotensin II infusion. Our findings indicate that angiotensin II-induced hypertension is accompanied by enhanced thrombosis in arterioles and this response is mediated by a mechanism that involves AT2, AT4, BK-1 and ET-1 receptor-mediated signaling. PMID:20975035

Type II universal spacetimes

NASA Astrophysics Data System (ADS)

Hervik, S.; Málek, T.; Pravda, V.; Pravdová, A.

2015-12-01

We study type II universal metrics of the Lorentzian signature. These metrics simultaneously solve vacuum field equations of all theories of gravitation with the Lagrangian being a polynomial curvature invariant constructed from the metric, the Riemann tensor and its covariant derivatives of an arbitrary order. We provide examples of type II universal metrics for all composite number dimensions. On the other hand, we have no examples for prime number dimensions and we prove the non-existence of type II universal spacetimes in five dimensions. We also present type II vacuum solutions of selected classes of gravitational theories, such as Lovelock, quadratic and L({{Riemann}}) gravities.

Structural characterization and antioxidant properties of Cu(II) and Ni(II) complexes derived from dicyandiamide

NASA Astrophysics Data System (ADS)

Kertmen, Seda Nur; Gonul, Ilyas; Kose, Muhammet

2018-01-01

New Cu(II) and Ni(II) complexes derived from dicyandiamide were synthesized and characterised by spectroscopic and analytical methods. Molecular structures of the complexes were determined by single crystal X-ray diffraction studies. In the complexes, the Cu(II) or Ni(II) ions are four-coordinate with a slight distorted square planar geometry. The ligands (L-nPen and L-iPen) derived from dicyandiamide formed via nucleophilic addition of alcohol solvent molecule in the presence Cu(II) or Ni(II) ions. Complexes were stabilised by intricate array of hydrogen bonding interactions. Antioxidant activity of the complexes was evaluated by DPPH radical scavenging and CUPRAC methods. The complexes exhibit antioxidant activity, however, their activities were much lower than standard antioxidants (Vitamin C and trolox).

Glutamate Ligation in the Ni(II)- and Co(II)-Responsive Escherichia coli Transcriptional Regulator, RcnR

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

Carr, Carolyn E.; Musiani, Francesco; Huang, Hsin-Ting

Escherichia coli RcnR (resistance to cobalt and nickel regulator, EcRcnR) is a metal-responsive repressor of the genes encoding the Ni(II) and Co(II) exporter proteins RcnAB by binding to PRcnAB. The DNA binding affinity is weakened when the cognate ions Ni(II) and Co(II) bind to EcRcnR in a six-coordinate site that features a (N/O)5S ligand donor-atom set in distinct sites: while both metal ions are bound by the N terminus, Cys35, and His64, Co(II) is additionally bound by His3. On the other hand, the noncognate Zn(II) and Cu(I) ions feature a lower coordination number, have a solvent-accessible binding site, and coordinatemore » protein ligands that do not include the N-terminal amine. A molecular model of apo-EcRcnR suggested potential roles for Glu34 and Glu63 in binding Ni(II) and Co(II) to EcRcnR. The roles of Glu34 and Glu63 in metal binding, metal selectivity, and function were therefore investigated using a structure/function approach. X-ray absorption spectroscopy was used to assess the structural changes in the Ni(II), Co(II), and Zn(II) binding sites of Glu → Ala and Glu → Cys variants at both positions. The effect of these structural alterations on the regulation of PrcnA by EcRcnR in response to metal binding was explored using LacZ reporter assays. These combined studies indicate that while Glu63 is a ligand for both metal ions, Glu34 is a ligand for Co(II) but possibly not for Ni(II). The Glu34 variants affect the structure of the cognate metal sites, but they have no effect on the transcriptional response. In contrast, the Glu63 variants affect both the structure and transcriptional response, although they do not completely abolish the function of EcRcnR. The structure of the Zn(II) site is not significantly perturbed by any of the glutamic acid variations. The spectroscopic and functional data obtained on the mutants were used to calculate models of the metal-site structures of EcRcnR bound to Ni(II), Co(II), and Zn(II). The results are

Spectroscopic, Elemental and Thermal Analysis, and Positron Annihilation Studies on Ca(II), Sr(II), Ba(II), Pb(II), and Fe(III) Penicillin G Potassium Complexes

NASA Astrophysics Data System (ADS)

Refat, M. S.; Sharshara, T.

2015-11-01

The [Pb(Pin)2] · 3H2O, [M(Pin)(H2O)2(Cl)] · nH2O (M = SrII, CaII or BaII; n = 0-1), and [Fe(Pin)2(Cl)(H2O)] · H2O penicillin G potassium (Pin) complexes were synthesized and characterized using elemental analyses, molar conductivity, thermal analysis and electronic spectroscopy techniques. The positron annihilation lifetime (PAL) and Doppler broadening (DB) techniques have been employed to probe the defects and structural changes of Pin ligand and its complexes. The PAL and DB line-shape parameters were discussed in terms of the structure, molecular weight, ligand-metal molar ratio, and other properties of the Pin complexes.

Probing HeII Reionization at z>3.5 with Resolved HeII Lyman Alpha Forest Spectra

NASA Astrophysics Data System (ADS)

Worseck, Gabor

2017-08-01

The advent of GALEX and COS have revolutionized our view of HeII reionization, the final major phase transition of the intergalactic medium. COS spectra of the HeII Lyman alpha forest have confirmed with high confidence the high HeII transmission that signifies the completion of HeII reionization at z 2.7. However, the handful of z>3.5 quasars observed to date show a set of HeII transmission 'spikes' and larger regions with non-zero transmission that suggest HeII reionization was well underway by z=4. This is in striking conflict with predictions from state-of-the-art radiative transfer simulations of a HeII reionization driven by bright quasars. Explaining these measurements may require either faint quasars or more exotic sources of hard photons at z>4, with concomitant implications for HI reionization. However, many of the observed spikes are unresolved in G140L spectra and are significantly impacted by Poisson noise. Current data cannot reliably probe the ionization state of helium at z>3.5.We request 41 orbits to obtain science-grade G130M spectra of the two UV-brightest HeII-transmitting QSOs at z>3.5 to confirm and resolve their HeII transmission spikes as an unequivocal test of early HeII reionization. These spectra are complemented by recently obtained data from 8m telescopes: (1) Echelle spectra of the coeval HI Lya forest to map the underlying density field that modulates the HeII absorption, and (2) Our dedicated survey for foreground QSOs that may source the HeII transmission. Our recent HST programs revealed the only two viable targets to resolve the z>3.5 HeII Lyman alpha forest, and to conclusively solve this riddle.

The TFIID components human TAF(II)140 and Drosophila BIP2 (TAF(II)155) are novel metazoan homologues of yeast TAF(II)47 containing a histone fold and a PHD finger.

PubMed

Gangloff, Y G; Pointud, J C; Thuault, S; Carré, L; Romier, C; Muratoglu, S; Brand, M; Tora, L; Couderc, J L; Davidson, I

2001-08-01

The RNA polymerase II transcription factor TFIID comprises the TATA binding protein (TBP) and a set of TBP-associated factors (TAF(II)s). TFIID has been extensively characterized for yeast, Drosophila, and humans, demonstrating a high degree of conservation of both the amino acid sequences of the constituent TAF(II)s and overall molecular organization. In recent years, it has been assumed that all the metazoan TAF(II)s have been identified, yet no metazoan homologues of yeast TAF(II)47 (yTAF(II)47) and yTAF(II)65 are known. Both of these yTAF(II)s contain a histone fold domain (HFD) which selectively heterodimerizes with that of yTAF(II)25. We have cloned a novel mouse protein, TAF(II)140, containing an HFD and a plant homeodomain (PHD) finger, which we demonstrated by immunoprecipitation to be a mammalian TFIID component. TAF(II)140 shows extensive sequence similarity to Drosophila BIP2 (dBIP2) (dTAF(II)155), which we also show to be a component of Drosophila TFIID. These proteins are metazoan homologues of yTAF(II)47 as their HFDs selectively heterodimerize with dTAF(II)24 and human TAF(II)30, metazoan homologues of yTAF(II)25. We further show that yTAF(II)65 shares two domains with the Drosophila Prodos protein, a recently described potential dTAF(II). These conserved domains are critical for yTAF(II)65 function in vivo. Our results therefore identify metazoan homologues of yTAF(II)47 and yTAF(II)65.

Multiple endocrine neoplasia (MEN) II

MedlinePlus

Sipple syndrome; MEN II; Pheochromocytoma - MEN II; Thyroid cancer - pheochromocytoma; Parathyroid cancer - pheochromocytoma ... The cause of MEN II is a defect in a gene called RET. This defect causes many tumors to appear in the same ...

Zn(II) stimulation of Fe(II)-activated repression in the iron-dependent repressor from Mycobacterium tuberculosis.

PubMed

Stapleton, Brian; Walker, Lawrence R; Logan, Timothy M

2013-03-19

Thermodynamic measurements of Fe(II) binding and activation of repressor function in the iron-dependent repressor from Mycobacterium tuberculosis (IdeR) are reported. IdeR, a member of the diphtheria toxin repressor family of proteins, regulates iron homeostasis and contributes to the virulence response in M. tuberculosis. Although iron is the physiological ligand, this is the first detailed analysis of iron binding and activation in this protein. The results showed that IdeR binds 2 equiv of Fe(II) with dissociation constants that differ by a factor of 25. The high- and low-affinity iron binding sites were assigned to physical binding sites I and II, respectively, using metal binding site mutants. IdeR was also found to contain a high-affinity Zn(II) binding site that was assigned to physical metal binding site II through the use of binding site mutants and metal competition assays. Fe(II) binding was modestly weaker in the presence of Zn(II), but the coupled metal binding-DNA binding affinity was significantly stronger, requiring 30-fold less Fe(II) to activate DNA binding compared to Fe(II) alone. Together, these results suggest that IdeR is a mixed-metal repressor, where Zn(II) acts as a structural metal and Fe(II) acts to trigger the physiologically relevant promoter binding. This new model for IdeR activation provides a better understanding of IdeR and the biology of iron homeostasis in M. tuberculosis.

Synthesis, magnetic, spectral, and antimicrobial studies of Cu(II), Ni(II) Co(II), Fe(III), and UO 2(II) complexes of a new Schiff base hydrazone derived from 7-chloro-4-hydrazinoquinoline

NASA Astrophysics Data System (ADS)

El-Behery, Mostafa; El-Twigry, Haifaa

2007-01-01

A new hydrazone ligand, HL, was prepared by the reaction of 7-chloro-4-hydrazinoquinoline with o-hydroxybenzaldehyde. The ligand behaves as monoprotic bidentate. This was accounted for as the ligand contains a phenolic group and its hydrogen atom is reluctant to be replaced by a metal ion. The ligand reacted with Cu(II), Ni(II), Co(II), Fe(III), and UO 2(II) ions to yield mononuclear complexes. In the case of Fe(III) ion two complexes, mono- and binuclear complexes, were obtained in the absence and presence of LiOH, respectively. Also, mixed ligand complexes were obtained from the reaction of the metal cations Cu(II), Ni(II) and Fe(III) with the ligand (HL) and 8-hydroxyquinoline (8-OHqu) in the presence of LiOH, in the molar ratio 1:1:1:1. It is clear that 8-OHqu behaves as monoprotic bidentate ligand in such mixed ligand complexes. The ligand, HL, and its metal complexes were characterized by elemental analyses, IR, UV-vis, mass, and 1H NMR spectra, as well as magnetic moment, conductance measurements, and thermal analyses. All complexes have octahedral configurations except Cu(II) complex which has an extra square-planar geometry, while Ni(II) mixed complex has also formed a tetrahedral configuration and UO 2(II) complex which formed a favorable pentagonal biprymidial geometry. Magnetic moment of the binuclear Fe(III) complex is quite low compared to calculated value for two iron ions complex and thus shows antiferromagnetic interactions between the two adjacent ferric ions. The HL and metal complexes were tested against one stain Gram positive bacteria ( Staphylococcus aureus), Gram negative bacteria ( Escherichia coli), and fungi ( Candida albicans). The tested compounds exhibited higher antibacterial acivities.

The Bipolar II Depression Questionnaire: A Self-Report Tool for Detecting Bipolar II Depression

PubMed Central

Leung, Chi Ming; Yim, Chi Lap; Yan, Connie T. Y.; Chan, Cheuk Chi; Xiang, Yu-Tao; Mak, Arthur D. P.; Fok, Marcella Lei-Yee; Ungvari, Gabor S.

2016-01-01

Bipolar II (BP-II) depression is often misdiagnosed as unipolar (UP) depression, resulting in suboptimal treatment. Tools for differentiating between these two types of depression are lacking. This study aimed to develop a simple, self-report screening instrument to help distinguish BP-II depression from UP depressive disorder. A prototype BP-II depression questionnaire (BPIIDQ-P) was constructed following a literature review, panel discussions and a field trial. Consecutively assessed patients with a diagnosis of depressive disorder or BP with depressive episodes completed the BPIIDQ-P at a psychiatric outpatient clinic in Hong Kong between October and December 2013. Data were analyzed using discriminant analysis and logistic regression. Of the 298 subjects recruited, 65 (21.8%) were males and 233 (78.2%) females. There were 112 (37.6%) subjects with BP depression [BP-I = 42 (14.1%), BP-II = 70 (23.5%)] and 182 (62.4%) with UP depression. Based on family history, age at onset, postpartum depression, episodic course, attacks of anxiety, hypersomnia, social phobia and agoraphobia, the 8-item BPIIDQ-8 was constructed. The BPIIDQ-8 differentiated subjects with BP-II from those with UP depression with a sensitivity/specificity of 0.75/0.63 for the whole sample and 0.77/0.72 for a female subgroup with a history of childbirth. The BPIIDQ-8 can differentiate BP-II from UP depression at the secondary care level with satisfactory to good reliability and validity. It has good potential as a screening tool for BP-II depression in primary care settings. Recall bias, the relatively small sample size, and the high proportion of females in the BP-II sample limit the generalization of the results. PMID:26963908

Enhanced Stability of the Fe(II)/Mn(II) State in a Synthetic Model of Heterobimetallic Cofactor Assembly.

PubMed

Kerber, William D; Goheen, Joshua T; Perez, Kaitlyn A; Siegler, Maxime A

2016-01-19

Heterobimetallic Mn/Fe cofactors are found in the R2 subunit of class Ic ribonucleotide reductases (R2c) and R2-like ligand binding oxidases (R2lox). Selective cofactor assembly is due at least in part to the thermodynamics of M(II) binding to the apoprotein. We report here equilibrium studies of Fe(II)/Mn(II) discrimination in the biomimetic model system H5(F-HXTA) (5-fluoro-2-hydroxy-1,3-xylene-α,α'-diamine-N,N,N',N'-tetraacetic acid). The homobimetallic F-HXTA complexes [Fe(H2O)6][1]2·14H2O and [Mn(H2O)6][2]2·14H2O (1 = [Fe(II)2(F-HXTA)(H2O)4](-); 2 = [Mn(II)2(F-HXTA)(H2O)4](-)) were characterized by single crystal X-ray diffraction. NMR data show that 1 retains its structure in solution (2 is NMR silent). Metal exchange is facile, and the heterobimetallic complex [Fe(II)Mn(II)(F-HXTA)(H2O)4](-) (3) is formed from mixtures of 1 and 2. (19)F NMR was used to quantify 1 and 3 in the presence of excess M(II)(aq) at various metal ratios, and equilibrium constants for Fe(II)/Mn(II) discrimination were calculated from these data. Fe(II) is preferred over Mn(II) with K1 = 182 ± 13 for complete replacement (2 ⇌ 1). This relatively modest preference is attributed to a hard-soft acid-base mismatch between the divalent cations and the polycarboxylate ligand. The stepwise constants for replacement are K2 = 20.1 ± 1.3 (2 ⇌ 3) and K3 = 9.1 ± 1.1 (3 ⇌ 1). K2 > K3 demonstrates enhanced stability of the heterobimetallic state beyond what is expected for simple Mn(II) → Fe(II) replacement. The relevance to Fe(II)/Mn(II) discrimination in R2c and R2lox proteins is discussed.

Employability Planning Process. STIP II (Skill Training Improvement Programs Round II).

ERIC Educational Resources Information Center

Los Angeles Community Coll. District, CA.

Four reports are presented detailing procedures for improving the employability of students enrolled in the Los Angeles Community College District's Skill Training Improvement Programs (STIP II). Each report was submitted by one of the four STIP II programs: Los Angeles Southwest College's program for computer programming; the programs for…

Tuning the spin ground state in heterononanuclear nickel(II)-copper(II) cylinders with a triangular metallacyclophane core.

PubMed

Dul, Marie-Claire; Ferrando-Soria, Jesús; Pardo, Emilio; Lescouëzec, Rodrigue; Journaux, Yves; Ruiz-García, Rafael; Cano, Joan; Julve, Miguel; Lloret, Francesc; Fabelo, Oscar; Pasán, Jorge; Ruiz-Pérez, Catalina

2010-12-20

Two new heterometallic Ni(II)(n)Cu(II)((9-n)) complexes [n = 1 (2) and 2 (3)] have been synthesized following a multicomponent self-assembly process from a n:(3 - n):2:6 stoichiometric mixture of Ni(2+), Cu(2+), L(6-), and [CuL'](2+), where L and L' are the bridging and blocking ligands 1,3,5-benzenetris(oxamate) and N,N,N',N'',N''-pentamethyldiethylenetriamine, respectively. Complexes 2 and 3 possess a unique cyclindrical architecture formed by three oxamato-bridged trinuclear linear units connected through two 1,3,5-substituted benzenetris(amidate) bridges, giving a triangular metallacyclophane core. They behave as a ferromagnetically coupled trimer of two (2)/one (3) S = (1)/(2) Cu(II)(3) plus one (2)/two (3) S = 0 Ni(II)Cu(II)(2) linear units with overall S = 1 Ni(II)Cu(II)(8) (2) and S = (1)/(2) Ni(II)(2)Cu(II)(7) (3) ground states.

Crystal and electronic structures of magnesium(II), copper(II), and mixed magnesium(II)-copper(II) complexes of the quinoline half of styrylquinoline-type HIV-1 integrase inhibitors.

PubMed

Courcot, B; Firley, D; Fraisse, B; Becker, P; Gillet, J-M; Pattison, P; Chernyshov, D; Sghaier, M; Zouhiri, F; Desmaële, D; d'Angelo, J; Bonhomme, F; Geiger, S; Ghermani, N E

2007-05-31

A new target in AIDS therapy development is HIV-1 integrase (IN). It was proven that HIV-1 IN required divalent metal cations to achieve phosphodiester bond cleavage of DNA. Accordingly, all newly investigated potent IN inhibitors contain chemical fragments possessing a high ability to chelate metal cations. One of the promising leads in the polyhydroxylated styrylquinolines (SQLs) series is (E)-8-hydroxy-2-[2-(4,5-dihydroxy-3-methoxyphenyl)-ethenyl]-7-quinoline carboxylic acid (1). The present study focuses on the quinoline-based progenitor (2), which is actually the most probable chelating part of SQLs. Conventional and synchrotron low-temperature X-ray crystallographic studies were used to investigate the chelating power of progenitor 2. Mg2+ and Cu2+ cations were selected for this purpose, and three types of metal complexes of 2 were obtained: Mg(II) complex (4), Cu(II) complex (5) and mixed Mg(II)-Cu(II) complexes (6 and 7). The analysis of the crystal structure of complex 4 indicates that two tridentate ligands coordinate two Mg2+ cations, both in octahedral geometry. The Mg-Mg distance was found equal to 3.221(1) A, in agreement with the metal-metal distance of 3.9 A encountered in the crystal structure of Escherichia coli DNA polymerase I. In 5, the complex is formed by two bidentate ligands coordinating one copper ion in tetrahedral geometry. Both mixed Mg(II)-Cu(II) complexes, 6 and 7 exhibit an original arrangement of four ligands linked to a central heterometallic cluster consisting of three octahedrally coordinated magnesium ions and one tetrahedrally coordinated copper ion. Quantum mechanics calculations were also carried out in order to display the electrostatic potential generated by the dianionic ligand 2 and complex 4 and to quantify the binding energy (BE) during the formation of the magnesium complex of progenitor 2. A comparison of the binding energies of two hypothetical monometallic Mg(II) complexes with that found in the bimetallic magnesium

Time-dependent changes in autonomic control of splanchnic vascular resistance and heart rate in ANG II-salt hypertension.

PubMed

Kuroki, Marcos T; Guzman, Pilar A; Fink, Gregory D; Osborn, John W

2012-02-01

Previous studies suggest that ANG II-induced hypertension in rats fed a high-salt (HS) diet (ANG II-salt hypertension) has a neurogenic component dependent on an enhanced sympathetic tone to the splanchnic veins and independent from changes in sympathetic nerve activity to the kidney or hind limb. The purpose of this study was to extend these findings and test whether altered autonomic control of splanchnic resistance arteries and the heart also contributes to the neurogenic component. Mean arterial pressure (MAP), heart rate (HR), superior mesenteric artery blood flow, and mesenteric vascular resistance (MVR) were measured during 4 control days, 14 days of ANG II delivered subcutaneously (150 ng·kg(-1)·min(-1)), and 4 days of recovery in conscious rats fed a HS (2% NaCl) or low-salt (LS; 0.1% NaCl) diet. Autonomic effects on MAP, HR, and MVR were assessed by acute ganglionic blockade with hexamethonium (20 mg/kg iv) on day 3 of control, days 1, 3, 5, 7, 10, and 13 of ANG II, and day 4 of recovery. MVR increased during ANG II infusion in HS and LS rats but remained elevated only in HS rats. Additionally, the MVR response to hexamethonium was enhanced on days 10 and 13 of ANG II selectively in HS rats. Compared with LS rats, HR in HS rats was higher during the 2nd wk of ANG II, and its response to hexamethonium was greater on days 7, 10, and 13 of ANG II. These results suggest that ANG II-salt hypertension is associated with delayed changes in autonomic control of splanchnic resistance arteries and the heart.

Preschool Racial Attitude Measure II (PRAM II): Technical Report #1: 1970-71 Standardization Study.

ERIC Educational Resources Information Center

Williams, John E.

This report provides detailed technical information concerning the Preschool Racial Attitude Measure II (PRAM II) a method for assessing the attitudes of pre-literate children toward light- and dark-skinned individuals. Several major changes were involved in the PRAM II revision: (1) the length was doubled, (2) the general artistic quality of the…

Evaluation of Sorption Mechanism of Pb (II) and Ni (II) onto Pea (Pisum sativum) Peels.

PubMed

Haq, Atta Ul; Saeed, Muhammad; Anjum, Salma; Bokhari, Tanveer Hussain; Usman, Muhammad; Tubbsum, Saiqa

2017-07-01

The present study was carried out to know the sorption mechanism of Pb (II) and Ni (II) in aqueous solution using pea peels under the influence of sorbent dose, pH, temperature, initial metal ion concentration and contact time. SEM and FTIR were used for characterization of pea peels. The study showed that solution pH affects sorption process and the optimum pH for Pb (II) was 6.0 while for that of Ni (II) was 7.0. Pseudo-second order kinetic model was found to be the most suitable one to explain the kinetic data not only due to high value of R 2 (>0.99) but also due to the closeness of the experimental sorption capacity values to that of calculated sorption capacity values of pseudo second order kinetic model. It can be seen from the results that Freundlich isotherm explains well the equilibrium data (R 2 >0.99). Sorption capacity of pea peels was 140.84 and 32.36 for Pb (II) and Ni (II) mg g -1 respectively. The positive value of ΔH° and negative values of ΔG° suggest that sorption of Pb (II) and Ni (II) onto pea peels is an endothermic and spontaneous process respectively.

Effect of cholesterol depletion on exocytosis of alveolar type II cells.

PubMed

Chintagari, Narendranath Reddy; Jin, Nili; Wang, Pengcheng; Narasaraju, Telugu Akula; Chen, Jiwang; Liu, Lin

2006-06-01

Alveolar epithelial type II cells secrete lung surfactant via exocytosis. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) are implicated in this process. Lipid rafts, the cholesterol- and sphingolipid-rich microdomains, may offer a platform for protein organization on the cell membrane. We tested the hypothesis that lipid rafts organize exocytotic proteins in type II cells and are essential for the fusion of lamellar bodies, the secretory granules of type II cells, with the plasma membrane. The lipid rafts, isolated from type II cells using 1% Triton X-100 and a sucrose gradient centrifugation, contained the lipid raft markers, flotillin-1 and -2, whereas they excluded the nonraft marker, Na+-K+ ATPase. SNAP-23, syntaxin 2, and VAMP-2 were enriched in lipid rafts. When type II cells were depleted of cholesterol, the association of SNAREs with the lipid rafts was disrupted and the formation of fusion pore was inhibited. Furthermore, the cholesterol-depleted plasma membrane had less ability to fuse with lamellar bodies, a process mediated by annexin A2. The secretagogue-stimulated secretion of lung surfactant from type II cells was also reduced by methyl-beta-cyclodextrin. When the raft-associated cell surface protein, CD44, was cross-linked using anti-CD44 antibodies, the CD44 clusters were observed. Syntaxin 2, SNAP-23, and annexin A2 co-localized with the CD44 clusters, which were cholesterol dependent. Our results suggested that lipid rafts may form a functional platform for surfactant secretion in alveolar type II cells, and raft integrity was essential for the fusion between lamellar bodies with the plasma membrane.

DNA cleavage, antibacterial, antifungal and anthelmintic studies of Co(II), Ni(II) and Cu(II) complexes of coumarin Schiff bases: Synthesis and spectral approach

NASA Astrophysics Data System (ADS)

Patil, Sangamesh A.; Prabhakara, Chetan T.; Halasangi, Bhimashankar M.; Toragalmath, Shivakumar S.; Badami, Prema S.

2015-02-01

The metal complexes of Co(II), Ni(II) and Cu(II) have been synthesized from 6-formyl-7,8-dihydroxy-4-methylcoumarin with o-toluidine/3-aminobenzotrifluoride. The synthesized Schiff bases and their metal complexes were structurally characterized based on IR, 1H NMR, 13C NMR, UV-visible, ESR, magnetic, thermal, fluorescence, mass and ESI-MS studies. The molar conductance values indicate that complexes are non-electrolytic in nature. Elemental analysis reveals ML2·2H2O [M = Co(II), Ni(II) and Cu(II)] stoichiometry, where 'L' stands for a singly deprotonated ligand. The presence of co-ordinated water molecules were confirmed by thermal studies. The spectroscopic studies suggest the octahedral geometry. Redox behavior of the complexes were confirmed by cyclic voltammetry. All the synthesized compounds were screened for their antibacterial (Escherichia coli, Pseudomonas auregenosa, klebsiella, Proteus, Staphylococcus aureus and salmonella) antifungal (Candida, Aspergillus niger and Rhizopus), anthelmintic (Pheretima posthuma) and DNA cleavage (Calf Thymus DNA) activity.

Preparation of ZrO II/nano-TiO II composite powder by sol-gel method

NASA Astrophysics Data System (ADS)

Baharvandi, H. R.; Mohammadi, E.; Abdizadeh, H.; Hadian, A. M.; Ehsani, N.

2007-07-01

The effects of concentration of TTIP, amount of distilled water, and calcination temperature on morphology and particle size distribution of ZrO II/nano-TiO II catalysts were investigated. Mixed ZrO II/nano-TiO II powders were prepared by a modified sol-gel method by varying the mole fraction of TTIP from 0.002 to 0.01, H IIO/TTIP fraction from 2 to 8, and various stirring time (2, 4, and 10 h). The prepared ZrO II/nano-TiO II powders have been characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and TG/DTA. Each oxide was calcined at the temperature between 110 and 1000°C. The results showed that the calcinations temperature has a pronounced effect on the phase formation and particle size of the calcined zirconium titanate (ZT) powders.

Human autoantibody to topoisomerase II.

PubMed

Hoffmann, A; Heck, M M; Bordwell, B J; Rothfield, N F; Earnshaw, W C

1989-02-01

The rheumatic diseases are characterized by the production of autoantibodies that are usually directed against components of the cell nucleus. In this communication, we describe autoantibodies that recognize DNA topoisomerase II (anti-topoII) present in the serum of a patient with systemic lupus erythematosus. Several lines of evidence indicate that this antibody recognizes topoisomerase II. First, it binds to the native enzyme in soluble extracts prepared from isolated chromosomes and effectively depletes such extracts of active enzyme. Second, the serum binds to topoisomerase II in immunoblots of mitotic chromosomes and chromosome scaffolds. Finally, the antiserum binds strongly to a fusion protein encoded by a cloned cDNA and expressed in Escherichia coli that (based on immunological evidence) represents the carboxy-terminal portion of chicken topoisomerase II. Autoantibodies such as the one described here may provide useful reagents for the study of human topoisomerase II.

Characterization of the Igf-II Binding Site of the IGF-II/MAN-6-P Receptor Extracellular Domain.

NASA Astrophysics Data System (ADS)

Garmroudi, Farideh

1995-01-01

In mammals, insulin-like growth factor II (IGF -II) and glycoproteins bearing the mannose 6-phosphate (Man -6-P) recognition marker bind with high affinity to the same receptor. The functional consequences of IGF-II binding to the receptor at the cell surface are not clear. In these studies, we sought to broaden our understanding of the functional regions of the receptor regarding its IGF -II binding site. The IGF-II binding/cross-linking domain of the IGF-II/Man-6-P receptor was mapped by sequencing receptor fragments covalently attached to IGF-II. Purified rat placental or bovine liver receptors were affinity-labeled, with ^{125}I-IGF-II and digested with endoproteinase Glu-C. Analysis of digests by gel electrophoresis revealed a major radiolabeled band of 18 kDa, which was purified by gel filtration chromatography followed by reverse-phase HPLC and electroblotting. Sequence analysis revealed that, the peptide S(H)VNSXPMF, located within extracellular repeat 10 and beginning with serine 1488 of the bovine receptor, was the best candidate for the IGF-II cross-linked peptide. These data indicated that residues within repeats 10-11 were important for IGF -II binding. To define the location of the IGF-II binding site further, a nested set of six human receptor cDNA constructs was designed to produce epitope-tagged fusion proteins encompassing the region between repeats 8 and 11 of the human IGF-II/Man-6-P receptor extracellular domain. These truncated receptors were transiently expressed in COS-7 cells, immunoprecipitated and analyzed for their abilities to bind and cross-link to IGF-II. All of the constructs were capable of binding/cross-linking to IGF-II, except for the 9.0-11 construct. Displacement curve analysis indicated that the truncated receptors were approximately equivalent in IGF-II binding affinity, but were of 5- to 10-fold lower affinity than full-length receptors. Sequencing of the 9.0-11 construct indicated the presence of a point mutation

Surface catalysis of uranium(VI) reduction by iron(II)

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

Liger, E.; Charlet, L.; Van Cappellen, P.

1999-10-01

Colloidal hematite ({alpha}-Fe{sub 2}O{sub 3}) is used as model solid to investigate the kinetic effect of specific adsorption interactions on the chemical reduction of uranyl (U{sup VI}O{sub 2}{sup 2+}) by ferrous iron. Acid-base titrations and Fe(II) and uranyl adsorption experiments are performed on hematite suspensions, under O{sub 2}- and CO{sub 2}-free conditions. The results are explained in terms of a constant capacitance surface complexation model of the hematite-aqueous solution interface. Two distinct Fe(II) surface complexes are required to reproduce the data: ({equivalent{underscore}to}Fe{sup III}OFe{sup II}){sup +} (or {equivalent{underscore}to}Fe{sup III}OFe{sup II}(OH{sub 2}){sub n}{sup +}) and {equivalent{underscore}to}Fe{sup III}OFe{sup II}OH{sup 0} (or {equivalent{underscore}to}Fe{sup III}OFe{supmore » II}(OH{sub 2}){sub n{minus}1}OH{sup 0}). The latter complex represents a significant fraction of total adsorbed Fe(II) at pH {gt} 6.5. Uranyl binding to the hematite particles is characterized by a sharp adsorption edge between pH 4 and pH 5.5. Because of the absence of competing aqueous carbonate complexes, uranyl remains completely adsorbed at pH {gt} 7. A single mononuclear surface complex accounts for the adsorption of uranyl over the entire range of experimental conditions. Although thermodynamically feasible, no reaction between uranyl and Fe(II) is observed in homogeneous solution at pH 7.5, for periods of up to three days. In hematite suspensions, however, surface-bound uranyl reacts on a time scale of hours. Based on Fourier Transformed Infrared spectra, chemical reduction of U(VI) is inferred to be the mechanism responsible for the disappearance of uranyl. The kinetics of uranyl reduction are quantified by measuring the decrease with time of the concentration of U(VI) extractable from the hematite particles by NaHCO{sub 3}. In the presence of excess Fe(II), the initial rate of U(VI) reduction exhibits a first-order dependence on the

Mu2e-II Injection from PIP-II

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

Neuffer, David

We discuss injection of 800 MeV proton beam from PIP-II into the production target for Mu2e-II, assuming a targeting and μ production scenario similar to mu2e. The incoming beam trajectory must be modified from the mu2e parameters to match the focusing fields. Adding a vertical deflection at injection enables the injected beam to reach the target. Other differences from the mu2e system must be considered, including changes in the target structure, the radiation shielding and beam dump/absorber. H- beam should be stripped to p+. Other variations are discussed.

Preferred crystallographic orientation in the ice I ← II transformation and the flow of ice II

USGS Publications Warehouse

Bennett, K.; Wenk, H.-R.; Durham, W.B.; Stern, L.A.; Kirby, S.H.

1997-01-01

The preferred crystallographic orientation developed during the ice I ← II transformation and during the plastic flow of ice II was measured in polycrystalline deuterium oxide (D2O) specimens using low-temperature neutron diffraction. Samples partially transformed from ice I to II under a non-hydrostatic stress developed a preferred crystallographic orientation in the ice II. Samples of pure ice II transformed from ice I under a hydrostatic stress and then when compressed axially, developed a strong preferred orientation of compression axes parallel to (1010). A match to the observed preferred orientation using the viscoplastic self-consistent theory was obtained only when (1010) [0001] was taken as the predominant slip system in ice II.

Syntheses, spectroscopic and thermal analyses of cyanide bridged heteronuclear polymeric complexes: [M(L)2Ni(CN)4]n (Ldbnd N-methylethylenediamine or N-ethylethylenediamine; Mdbnd Ni(II), Cu(II), Zn(II) or Cd(II))

NASA Astrophysics Data System (ADS)

Karaağaç, Dursun; Kürkçüoğlu, Güneş Süheyla

2016-02-01

Polymeric tetracyanonickelate(II) complexes of the type [M(L)2Ni(CN)4]n (Ldbnd N-methylethylenediamine (men) or N-ethylethylenediamine (neen); Mdbnd Ni(II), Cu(II), Zn(II) or Cd(II)) have been prepared and characterized by FT-IR, Raman spectroscopy, thermal and elemental analysis techniques. Additionally, FT-IR and Raman spectral analyses of men and neen have experimentally and theoretically investigated in the range of 4000-250 cm-1. The corresponding vibration assignments of men and neen are performed by using B3LYP density functional theory (DFT) method together with 6-31 G(d) basis set. The spectral features of the complexes suggest that the coordination environment of the M(II) ions are surrounded by the two symmetry related men and neen ligands and the two symmetry related N atom of cyanide groups, whereas the Ni(II) atoms are coordinated with a square-planar to four C atoms of the cyanide groups. Polymeric structures of the complexes consist of one dimensional alternative chains of [M(L)2]2+ and [Ni(CN)4]2- moieties. The thermal decompositions in the temperature range 30-700 °C of the complexes were investigated in the static air atmosphere.

Theoretical Study of Free Energy in Docking Stability of Azurin(II)-Cytochrome c551(II) Complex System

NASA Astrophysics Data System (ADS)

Yamamoto, Tetsunori; Nishikawa, Keigo; Sugiyama, Ayumu; Purqon, Acep; Mizukami, Taku; Shimahara, Hideto; Nagao, Hidemi; Nishikawa, Kiyoshi

2008-02-01

The docking structure of the Azurin-Cytochrome C551 is presented. We investigate a complex system of Azurin(II)-Cytochrome C551(II) by using molecular dynamics simulation. We estimate some physical properties, such as root-mean-square deviation (RMSD), binding energy between Azurin and Cytochrome C551, distance between Azurin(II) and Cytochrome C551(II) through center of mass and each active site. We also discuss docking stability in relation to the configuration by free energy between Azurin(II)-Cytochrome C551(II) and Azurin(I)-Cytochrome C551(III).

Retrovirus Epidemiology Donor Study-II (REDS-II)

ClinicalTrials.gov

2016-04-14

Acquired Immunodeficiency Syndrome; Blood Donors; Blood Transfusion; HIV Infections; HIV-1; HIV-2; HTLV-I; HTLV-II; Retroviridae Infections; Hepatitis, Viral, Human; Hepatitis B; Hepacivirus; West Nile Virus

Assembly and Properties of Heterobimetallic CoII/III/CaII Complexes with Aquo and Hydroxo Ligands

PubMed Central

Lacy, David C.; Park, Young Jun; Ziller, Joseph W.; Yano, Junko; Borovik, A. S.

2012-01-01

The use of water as a reagent in redox-driven reactions is advantageous because it is abundant and environmentally compatible. The conversion of water to dioxygen in photosynthesis illustrates one example, in which a redox-inactive CaII ion and four manganese ions are required for function. In this report we describe the stepwise formation of two new heterobimetallic complexes containing CoII/III and CaII ions, and either hydroxo or aquo ligands. The preparation of a 4-coordinate CoII synthon was achieved with the tripodal ligand, N,N′,N″-[2,2′,2″-nitrilotris(ethane-2,1-diyl)]tris(2,4,6-trimethylbenzenesulfonamido, [MST]3−. Water binds to [CoIIMST]− to form the 5-coordinate [CoIIMST(OH2)]− complex that was used to prepare the CoII/CaII complex [CoIIMST(μ-OH2)CaII⊂15-crown-5(OH2)]+ ([CoII(μ-OH2)CaIIOH2]+). [CoII(μ-OH2)CaOH2]+ contained two aquo ligands, one bonded to the CaII ion and one bridging between the two metal ions and thus represents an unusual example of a heterobimetallic complex containing 2 aquo ligands spanning different metal ions. Both aquo ligands formed intramolecular hydrogen bonds with the [MST]3− ligand. [CoIIMST(OH2)]− was oxidized to form [CoIIIMST(OH2)] that was further converted to [CoIIIMST(μ-OH)CaII⊂15-crown-5]+ ([CoIII(μ-OH)CaII]+) in the presence of base and CaIIOTf2/15-crown-5. [CoIII(μ-OH)CaII]+ was also synthesized from the oxidation of [CoIIMST]− with PhIO in the presence of CaIIOTf2/15-crown-5. Allowing [CoIII(μ-OH)CaII]+ to react with diphenylhydrazine afforded [CoII(μ-OH2)CaIIOH2]+ and azobenzene. Additionally, the characterization of [CoIII(μ-OH)CaII]+ provides another formulation for the previously reported CoIV–oxo complex, [(TMG3tren)CoIV(μ-O)ScIII(OTf)3]2+ to one that instead could contain a CoIII–OH unit. PMID:22998407

Structural analysis of group II chitinase (ChtII) catalysis completes the puzzle of chitin hydrolysis in insects.

PubMed

Chen, Wei; Qu, Mingbo; Zhou, Yong; Yang, Qing

2018-02-23

Chitin is a linear homopolymer of N -acetyl-β-d-glucosamines and a major structural component of insect cuticles. Chitin hydrolysis involves glycoside hydrolase family 18 (GH18) chitinases. In insects, chitin hydrolysis is essential for periodic shedding of the old cuticle ecdysis and proceeds via a pathway different from that in the well studied bacterial chitinolytic system. Group II chitinase (ChtII) is a widespread chitinolytic enzyme in insects and contains the greatest number of catalytic domains and chitin-binding domains among chitinases. In Lepidopterans, ChtII and two other chitinases, ChtI and Chi-h, are essential for chitin hydrolysis. Although ChtI and Chi-h have been well studied, the role of ChtII remains elusive. Here, we investigated the structure and enzymology of Of ChtII, a ChtII derived from the insect pest Ostrinia furnacalis We present the crystal structures of two catalytically active domains of Of ChtII, Of ChtII-C1 and Of ChtII-C2, both in unliganded form and complexed with chitooligosaccharide substrates. We found that Of ChtII-C1 and Of ChtII-C2 both possess long, deep substrate-binding clefts with endochitinase activities. Of ChtII exhibited structural characteristics within the substrate-binding cleft similar to those in Of Chi-h and Of ChtI. However, Of ChtII lacked structural elements favoring substrate binding beyond the active sites, including an extra wall structure present in Of Chi-h. Nevertheless, the numerous domains in Of ChtII may compensate for this difference; a truncation containing one catalytic domain and three chitin-binding modules ( Of ChtII-B4C1) displayed activity toward insoluble polymeric substrates that was higher than those of Of Chi-h and Of ChtI. Our observations provide the last piece of the puzzle of chitin hydrolysis in insects. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

On the ortho-positronium quenching reactions promoted by Fe(II), Fe(III), Co(III), Ni(II), Zn(II) and Cd(II) cyanocomplexes

NASA Astrophysics Data System (ADS)

Fantola Lazzarini, Anna L.; Lazzarini, Ennio

The o-Ps quenching reactions promoted in aqueous solutions by the following six cyanocomplexes: [Fe(CN) 6] 4-; [Co(CN) 6] 3-; [Zn(CN) 4] 2-; [Cd(CN) 6] 2-; [Fe(CN) 6] 3-; [Ni(CN) 4] 2- were investigated. The first four reactions probably consist in o-Ps addition across the CN bond, their rate constants at room temperature, Tr, being ⩽(0.04±0.02) × 10 9 M -1 s -1, i.e. almost at the limit of experimental errors. The rate constant of the fifth reaction, in o-Ps oxydation, at Tr is (20.3±0.4) × 10 9 M -1 s -1. The [Ni(CN) 4] 2-k value at Tr, is (0.27±0.01) × 10 9 M -1 s -1, i.e. 100 times less than the rate constants of o-Ps oxydation, but 10 times larger than those of the o-Ps addition across the CN bond. The [Ni(CN) 4] 2- reaction probably results in formation of the following positronido complex: [Ni(CN) 4Ps] 2-. However, it is worth noting that the existence of such a complex is only indirectly deduced. In fact it arises from comparison of the [Ni(CN) 4] 2- rate constant with those of the Fe(II), Zn(II), Cd(II), and Co(III) cyanocomplexes, which, like the Ni(II) cyanocomplex, do not promote o-Ps oxydation or spin exchange reactions.

Synthesis and structural characterisation of iron(II) and copper(II) diphosphates containing flattened metal oxotetrahedra

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

Keates, Adam C.; Wang, Qianlong; Weller, Mark T., E-mail: m.t.weller@bath.ac.uk

2014-02-15

Single crystal and bulk polycrystalline forms of K{sub 2}MP{sub 2}O{sub 7} (M=Fe(II), Cu(II)) have been synthesised and their structures determined from single crystal X-ray diffraction data. Both compounds crystallize in the tetragonal system, space group P-42{sub 1}m. Their structures are formed from infinite sheets of linked oxopolyhedra of the stoichiometry [MP{sub 2}O{sub 7}]{sup 2−} with potassium cations situated between the layers. The MO{sub 4} tetrahedra share oxygen atoms with [P{sub 2}O{sub 7}]{sup 4−} diphosphate groups and the potassium ions have KO{sub 8} square prismatic geometry. In both compounds the M(II) centre has an unusual strongly flattened, tetrahedral coordination to oxygen,more » as a result of the Jahn–Teller (JT) effect for the high spin d{sup 6} Fe(II) and p-orbital mixing or a second order JT effect for d{sup 9} Cu(II) centres in four fold coordination. The uncommon transition metal ion environments found in these materials are reflected in their optical absorption spectra and magnetism data. - Graphical abstract: The structures of the tetragonal polymorphs of K{sub 2}MP{sub 2}O{sub 7}, M=Cu(II), Fe(II), consist of infinite sheets of stoichiometry [MP{sub 2}O{sub 7}]{sup 2−}, formed from linked pyrophosphate groups and MO{sub 4} tetrahedra, separated by potassium ions. In both compounds the unusual tetrahedral coordination of the M(II) centre is strongly flattened as a result of Jahn–Teller (JT) effects for high spin, d{sup 6} Fe(II) and p-orbital mixing and second-order JT effects for d{sup 9} Cu(II). Display Omitted - Highlights: • Tetrahedral copper and iron(II) coordinated by oxygen. • New layered phosphate structure. • Jahn–Teller and d{sup 10} distorted coordinations.« less

Synthesis, spectroscopic and thermal studies of Mg(II), Ca(II), Sr(II) and Ba(II) diclofenac sodium complexes as anti-inflammatory drug and their protective effects on renal functions impairment and oxidative stress

NASA Astrophysics Data System (ADS)

El-Megharbel, Samy M.; Hamza, Reham Z.; Refat, Moamen S.

2015-01-01

The main task of our present study is the preparation of newly complexes of Mg(II), Ca(II), Sr(II) and Ba(II) with diclofenac which succeeded to great extent in alleviating the side effects of diclofenac alone and ameliorating the kidney function parameters and antioxidant capacities with respect to diclofenac treated group alone. The Mg(II), Ca(II), Sr(II) and Ba(II) with diclofenac have been synthesized and characterized using infrared, electronic and 1H NMR spectral, thermogravimetric and conductivity measurements. The diclofenac ligand has been found to act as bidentate chelating agent. Diclofenac complexes coordinate through the oxygen's of the carboxyl group. The molar ratio chelation is 1:2 (M2+-dic) with general formula [M(dic)2(H2O)2]ṡnH2O. Antibacterial screening of the alkaline earth metal complexes against Escherichia coli (Gram - ve), Bacillus subtilis (Gram + ve) and anti-fungal (Asperagillus oryzae, Asperagillus niger, Asperagillus flavus) were investigated. The kidney functions in male albino rats were ameliorated upon treatment with metal complexes of dic, which are represented by decreasing the levels of urea and uric acid to be located within normal values. The other looks bright spot in this article is the assessment of antioxidant defense system including SOD, CAT and MDA with the help of Sr2+, Mg2+ and Ca2+-dic complexes. The hormones related to kidney functions and stresses have been greatly ameliorated in groups treated with dic complexes in comparable with dic treated group.

Electronic influences of bridging and chelating diimine ligand coordination in formamidinate-bridged Rh 2 (II,II) dimers

DOE PAGES

White, Travis A.; Dunbar, Kim R.; Thummel, Randolph P.; ...

2015-10-22

We report two new formamidinate-bridged Rh 2 II,II complexes, cis-[Rh 2 II,II(μ-DTolF) 2(μ-np) 2] 2+ (3; DTolF = N,N'-di-p-tolylformamidinate; np = 1,8-naphthyridine) and cis-[Rh 2 II,II(μ-DTolF) 2(κ 2-dap) 2] 2+ (4; dap = 1,12-diazaperylene), were synthesized from cis-[Rh 2 II,II(μ-DTolF) 2(CH 3CN) 6](BF 4) 2 (1), and their properties were compared to those of cis-[Rh 2 II,II(μ-DTolF) 2(phen) 2](BF 4) 2 (2). Density functional theory (DFT) and electrochemical analyses support the description of the highest occupied molecular orbitals (HOMOs) of 3 and 4 as possessing contributions from the metals and formamidinate bridging ligands, with Rh 2/form character, and lowest unoccupiedmore » molecular orbitals (LUMOs) localized on the respective diimine ligand np and dap π* orbitals. Both 3 and 4 display strong, low energy Rh 2/form → diimine(π*) metal/ligand-to-ligand charger transfer ( 1ML–LCT) transitions with maxima at 566 nm (ε = 3600 M -1 cm -1) for 3 and at 630 nm (ε = 2900 M -1 cm -1) for 4 in CH 3CN. Time dependent-DFT (TD-DFT) calculations support these assignments. Finally, the ability of both the bridging np and chelating dap diimine ligands to produce strong absorption of these Rh 2 II,II complexes throughout the visible region is potentially useful for the development of new photocatalysts for H 2 production and photochemotherapeutics.« less

Endothelial-monocyte activating polypeptide II disrupts alveolar epithelial type II to type I cell transdifferentiation

PubMed Central

2012-01-01

Background Distal alveolar morphogenesis is marked by differentiation of alveolar type (AT)-II to AT-I cells that give rise to the primary site of gas exchange, the alveolar/vascular interface. Endothelial-Monocyte Activating Polypeptide (EMAP) II, an endogenous protein with anti-angiogenic properties, profoundly disrupts distal lung neovascularization and alveolar formation during lung morphogenesis, and is robustly expressed in the dysplastic alveolar regions of infants with Bronchopulmonary dysplasia. Determination as to whether EMAP II has a direct or indirect affect on ATII→ATI trans-differentiation has not been explored. Method In a controlled nonvascular environment, an in vitro model of ATII→ATI cell trans-differentiation was utilized to demonstrate the contribution that one vascular mediator has on distal epithelial cell differentiation. Results Here, we show that EMAP II significantly blocked ATII→ATI cell transdifferentiation by increasing cellular apoptosis and inhibiting expression of ATI markers. Moreover, EMAP II-treated ATII cells displayed myofibroblast characteristics, including elevated cellular proliferation, increased actin cytoskeleton stress fibers and Rho-GTPase activity, and increased nuclear:cytoplasmic volume. However, EMAP II-treated cells did not express the myofibroblast markers desmin or αSMA. Conclusion Our findings demonstrate that EMAP II interferes with ATII → ATI transdifferentiation resulting in a proliferating non-myofibroblast cell. These data identify the transdifferentiating alveolar cell as a possible target for EMAP II's induction of alveolar dysplasia. PMID:22214516

Structural principles and thermoelectric properties of polytypic group 14 clathrate-II frameworks.

PubMed

Karttunen, Antti J; Fässler, Thomas F

2013-06-24

We have investigated the structural principles and thermoelectric properties of polytypic group 14 clathrate-II frameworks using quantum chemical methods. The experimentally known cubic 3C polytype was found to be the energetically most favorable framework, but the studied hexagonal polytypes (2 H, 4 H, 6 H, 8 H, 10 H) lie energetically close to it. In the case of germanium, the energy difference between the 3C and 6H clathrate-II polytypes is ten times smaller than the difference between the experimentally known 3C-Ge (α-Ge) and 4H-Ge polytypes. The thermoelectric properties of guest-occupied clathrate-II structures were investigated for compositions Na-Rb-Ga-Ge and Ge-As-I. The clathrate-II structures show promising thermoelectric properties and the highest Seebeck coefficients and thermoelectric power factors were predicted for the 3C polytype. The structural anisotropy of the largest studied hexagonal polytypes affects their thermoelectric power factors by over a factor of two. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

SAMS-II Requirements and Operations

NASA Technical Reports Server (NTRS)

Wald, Lawrence W.

1998-01-01

The Space Acceleration Measurements System (SAMS) II is the primary instrument for the measurement, storage, and communication of the microgravity environment aboard the International Space Station (ISS). SAMS-II is being developed by the NASA Lewis Research Center Microgravity Science Division to primarily support the Office of Life and Microgravity Science and Applications (OLMSA) Microgravity Science and Applications Division (MSAD) payloads aboard the ISS. The SAMS-II is currently in the test and verification phase at NASA LeRC, prior to its first hardware delivery scheduled for July 1998. This paper will provide an overview of the SAMS-II instrument, including the system requirements and topology, physical and electrical characteristics, and the Concept of Operations for SAMS-II aboard the ISS.

Angiotensin II in Refractory Septic Shock.

PubMed

Antonucci, Elio; Gleeson, Patrick J; Annoni, Filippo; Agosta, Sara; Orlando, Sergio; Taccone, Fabio Silvio; Velissaris, Dimitrios; Scolletta, Sabino

2017-05-01

Refractory septic shock is defined as persistently low mean arterial blood pressure despite volume resuscitation and titrated vasopressors/inotropes in patients with a proven or suspected infection and concomitant organ dysfunction. Its management typically requires high doses of catecholamines, which can induce significant adverse effects such as ischemia and arrhythmias. Angiotensin II (Ang II), a key product of the renin-angiotensin-aldosterone system, is a vasopressor agent that could be used in conjunction with other vasopressors to stabilize critically ill patients during refractory septic shock, and reduce catecholamine requirements. However, very few clinical data are available to support Ang II administration in this setting. Here, we review the current literature on this topic to better understand the role of Ang II administration during refractory septic shock, differentiating experimental from clinical studies. We also consider the potential role of exogenous Ang II administration in specific organ dysfunction and possible pitfalls with Ang II in sepsis. Various issues remain unresolved and future studies should investigate important topics such as: the optimal dose and timing of Ang II administration, a comparison between Ang II and the other vasopressors (epinephrine; vasopressin), and Ang II effects on microcirculation.

Lifetimes and Oscillator Strengths for Ultraviolet Transitions in P II, Cl II and Cl III

NASA Technical Reports Server (NTRS)

Cheng, S.; Federman, S. R.; Schectman, R. M.; Brown, M.; Irving, R. E.; Fritts, M. C.; Gibson, N. D.

2006-01-01

Oscillator strengths for transitions in P II, Cl II and Cl III are derived from lifetimes and branching factions measured with beam-foil techniques. The focus is on the multiplets with a prominent interstellar line at 1153 A in P II which is seen in spectra of hot stars, and the lines at 1071 A in Cl II and 1011 A in Cl III whose lines are seen in spectra of diffuse interstellar clouds and the Io torus acquired with the Far Ultraviolet Spectroscopic Explorer. These data represent the first complete set of experimental f-values for the lines in the multiplets. Our results for P II (lambda)1153 agree well with Curtis semi-empirical predictions, as well as the large scale computations by Hibbert and by Tayal. The data for Cl II (lambda)1071 also agree very well with the most recent theoretical effort and with Morton s newest recommendations. For Cl III, however, our f-values are significantly larger than those given by Morton; instead, they are more consistent with recent large-scale theoretical calculations. Extensive tests provide confirmation that LS coupling rules apply to the transitions for the multiplets in Cl II and Cl III.

DNA cleavage, antibacterial, antifungal and anthelmintic studies of Co(II), Ni(II) and Cu(II) complexes of coumarin Schiff bases: synthesis and spectral approach.

PubMed

Patil, Sangamesh A; Prabhakara, Chetan T; Halasangi, Bhimashankar M; Toragalmath, Shivakumar S; Badami, Prema S

2015-02-25

The metal complexes of Co(II), Ni(II) and Cu(II) have been synthesized from 6-formyl-7,8-dihydroxy-4-methylcoumarin with o-toluidine/3-aminobenzotrifluoride. The synthesized Schiff bases and their metal complexes were structurally characterized based on IR, (1)H NMR, (13)C NMR, UV-visible, ESR, magnetic, thermal, fluorescence, mass and ESI-MS studies. The molar conductance values indicate that complexes are non-electrolytic in nature. Elemental analysis reveals ML2·2H2O [M = Co(II), Ni(II) and Cu(II)] stoichiometry, where 'L' stands for a singly deprotonated ligand. The presence of co-ordinated water molecules were confirmed by thermal studies. The spectroscopic studies suggest the octahedral geometry. Redox behavior of the complexes were confirmed by cyclic voltammetry. All the synthesized compounds were screened for their antibacterial (Escherichia coli, Pseudomonas auregenosa, klebsiella, Proteus, Staphylococcus aureus and salmonella) antifungal (Candida, Aspergillus niger and Rhizopus), anthelmintic (Pheretima posthuma) and DNA cleavage (Calf Thymus DNA) activity. Copyright © 2014 Elsevier B.V. All rights reserved.

Anticancer, antibacterial and antifungal activity of new ni (ii) and cu (ii) complexes of imidazole-phenanthroline derivatives.

PubMed

Moghadam, Mahboube Eslami; Divsalar, Adeleh; Zare, Marziye Shahraki; Gholizadeh, Roghayeh; Mahalleh, Doran; Saghatforosh, Lotfali; Sanati, Soheila

2017-11-02

Two new nickel(II) and copper(II) complexes of 2-(Furan-2-yl)-1H-Imidazo[4,5-f][1,10]Phenanthroline (FIP) and 2-(thiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (TIP), imidazophen derivatives were synthesized. The structures of the compounds were determined by UV-visible and FT-IR spectroscopic methods and elemental analysis. The biological activities of Ni and Cu complexes, as anticancer agents, were tested against chronic myelogenous leukemia cell line, K562, at micromolar concentration. The MTT studies showed Cc 50 values are 21 and 160 µM for Cu and Ni(II) complexes, respectively; suggesting that Ni (II) complex has Cc 50 almost seven times of that obtained for cisplatin. Biological activity of the Ni(II) and Cu(II) complexes were also assayed against selective microorganisms by disc diffusion method. These results showed that the Cu(II) complex is antifungal agent but Ni(II) complex has antibacterial activity.

Reduced Graphene Oxide-Immobilized Tris(bipyridine)ruthenium(II) Complex for Efficient Visible-Light-Driven Reductive Dehalogenation Reaction.

PubMed

Li, Xiaoyan; Hao, Zhongkai; Zhang, Fang; Li, Hexing

2016-05-18

A sodium benzenesulfonate (PhSO3Na)-functionalized reduced graphene oxide was synthesized via a two-step aryl diazonium coupling and subsequent NaCl ion-exchange procedure, which was used as a support to immobilize tris(bipyridine)ruthenium(II) complex (Ru(bpy)3Cl2) by coordination reaction. This elaborated Ru(bpy)3-rGO catalyst exhibited excellent catalytic efficiency in visible-light-driven reductive dehalogenation reactions under mild conditions, even for ary chloride. Meanwhile, it showed the comparable reactivity with the corresponding homogeneous Ru(bpy)3Cl2 catalyst. This high catalytic performance could be attributed to the unique two-dimensional sheet-like structure of Ru(bpy)3-rGO, which efficiently diminished diffusion resistance of the reactants. Meanwhile, the nonconjugated PhSO3Na-linkage between Ru(II) complex and the support and the very low electrical conductivity of the catalyst inhibited energy/electron transfer from Ru(II) complex to rGO support, resulting in the decreased support-induced quenching effect. Furthermore, it could be easily recycled at least five times without significant loss of catalytic reactivity.

Diet History Questionnaire II (DHQ II) for U.S. and Canada | EGRP/DCCPS/NCI/NIH

Cancer.gov

The Diet History Questionnaire II (DHQ II) is a freely available food frequency questionnaire (FFQ) for use by researchers, clinicians, or educators to assess food and dietary supplement intakes. The Canadian version of DHQ II is still available, but there is a newer U.S. version, DHQ III.

Influence of pH, soil humic/fulvic acid, ionic strength, foreign ions and addition sequences on adsorption of Pb(II) onto GMZ bentonite.

PubMed

Wang, Suowei; Hu, Jun; Li, Jiaxing; Dong, Yunhui

2009-08-15

This work contributed to the adsorption of Pb(II) onto GMZ bentonite in the absence and presence of soil humic acid (HA)/fulvic acid (FA) using a batch technique. The influences of pH from 2 to 12, ionic strengths from 0.004M to 0.05M NaNO(3), soil HA/FA concentrations from 1.6 mg/L to 20mg/L, foreign cations (Li+, Na+, K+), anions (Cl(-), NO(3)(-)), and addition sequences on the adsorption of Pb(II) onto GMZ bentonite were tested. The adsorption isotherms of Pb(II) were determined at pH 3.6+/-0.1 and simulated with the Langmuir, Freundlich, and D-R adsorption models, respectively. The results demonstrated that the adsorption of Pb(II) onto GMZ bentonite increased with increasing pH from 2 to 6. HA was shown to enhance Pb(II) adsorption at low pH, but to reduce Pb(II) adsorption at high pH, whereas FA was shown to decrease Pb(II) adsorption at pH from 2 to 11. The results also demonstrated that the adsorption was strongly dependent on ionic strength and slightly dependent on the concentration of HA/FA. The adsorption of Pb(II) onto GMZ bentonite was dependent on foreign ions in solution. The addition sequences of bentonite/Pb(II)/HA had no effect on the adsorption of Pb(II).

RNA Polymerase II Elongation Control

PubMed Central

Zhou, Qiang; Li, Tiandao; Price, David H.

2014-01-01

Regulation of the elongation phase of transcription by RNA Polymerase II (Pol II) is utilized extensively to generate the pattern of mRNAs needed to specify cell types and to respond to environmental changes. After Pol II initiates, negative elongation factors cause it to pause in a promoter proximal position. These polymerases are poised to respond to the positive transcription elongation factor, P-TEFb, and then enter productive elongation only under the appropriate set of signals to generate full length properly processed mRNAs. Recent global analyses of Pol II and elongation factors, mechanisms that regulate P-TEFb involving the 7SK snRNP, factors that control both the negative and positive elongation properties of Pol II and the mRNA processing events that are coupled with elongation are discussed. PMID:22404626

BORE II

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

Bore II, co-developed by Berkeley Lab researchers Frank Hale, Chin-Fu Tsang, and Christine Doughty, provides vital information for solving water quality and supply problems and for improving remediation of contaminated sites. Termed "hydrophysical logging," this technology is based on the concept of measuring repeated depth profiles of fluid electric conductivity in a borehole that is pumping. As fluid enters the wellbore, its distinct electric conductivity causes peaks in the conductivity log that grow and migrate upward with time. Analysis of the evolution of the peaks enables characterization of groundwater flow distribution more quickly, more cost effectively, and with higher resolutionmore » than ever before. Combining the unique interpretation software Bore II with advanced downhole instrumentation (the hydrophysical logging tool), the method quantifies inflow and outflow locations, their associated flow rates, and the basic water quality parameters of the associated formation waters (e.g., pH, oxidation-reduction potential, temperature). In addition, when applied in conjunction with downhole fluid sampling, Bore II makes possible a complete assessment of contaminant concentration within groundwater.« less

Synthesis, characterization and in vitro anticancer activity of 18-membered octaazamacrocyclic complexes of Co(II), Ni(II), Cd(II) and Sn(II)

NASA Astrophysics Data System (ADS)

Kareem, Abdul; Zafar, Hina; Sherwani, Asif; Mohammad, Owais; Khan, Tahir Ali

2014-10-01

An effective series of 18 membered octaazamacrocyclic complexes of the type [MLX2], where X = Cl or NO3 have been synthesized by template condensation reaction of oxalyl dihydrazide with dibenzoylmethane and metal salt in 2:2:1 molar ratio. The formation of macrocyclic framework, stereochemistry and their overall geometry have been characterized by various physico-chemical studies viz., elemental analysis, electron spray ionization-mass spectrometry (ESI-MS), I.R, UV-Vis, 1H NMR, 13C NMR spectroscopy, X-ray diffraction (XRD) and TGA/DTA studies. These studies suggest formation of octahedral macrocyclic complexes of Co(II), Ni(II), Cd(II) and Sn(II). The molar conductance values suggest nonelectrolytic nature for all the complexes. Thermogravimatric analysis shows that all the complexes are stable up to 600 °C. All these complexes have been tested against different human cancer cell lines i.e. human hepatocellular carcinoma (Hep3B), human cervical carcinoma (HeLa), human breast adenocarcinoma (MCF7) and normal cells (PBMC). The newly synthesized 18-membered octaazamacrocyclic complexes during in vitro anticancer evaluation, displayed moderate to good cytotoxicity on liver (Hep3B), cervical (HeLa) and breast (MCF7) cancer cell lines, respectively. The most effective anticancer cadmium complex (C34H28N10CdO10) was found to be active with IC50 values, 2.44 ± 1.500, 3.55 ± 1.600 and 4.82 ± 1.400 in micro-molar on liver, cervical and breast cancer cell lines, respectively.

C-reactive protein: A differential biomarker for major depressive disorder and bipolar II disorder.

PubMed

Chang, Hui Hua; Wang, Tzu-Yun; Lee, I Hui; Lee, Sheng-Yu; Chen, Kao Chin; Huang, San-Yuan; Yang, Yen Kuang; Lu, Ru-Band; Chen, Po See

2017-02-01

Objectives We aimed to examine whether the C-reactive protein (CRP) level could be used to differentiate between major depressive disorder (MDD) and bipolar II disorder (BD II). Methods Ninety-six healthy controls, 88 BD II and 72 MDD drug-naïve patients in their major depressive episodes were enrolled. The fasting plasma level of high-sensitivity CRP was assessed at baseline and after treatment. Results The BD II patients presented significantly higher 17-item Hamilton Depression Rating Scale (HDRS) scores and CRP levels at baseline when adjustment for age, gender, and body mass index (P <  0.001 and P <  0.001, respectively). After treatment the CRP levels remained significantly different (P <  0.001), although the HDRS score was not significantly different between the BD II and MDD patients. A receiver-operating characteristic analysis showed that a baseline CRP level of 621.6 ng/mL could discriminate between BD II and MDD, with an area under the curve of 0.816 and a sensitivity and specificity of 0.699 and 0.882, respectively. Furthermore, the baseline CRP level greater than 621.6 ng/ml had 28.2 higher odds of a diagnosis of BD II (P <  0.001, 95% confidence interval: 10.96-72.35). Conclusions The level of CRP plays a role of biomarker to differentiate between MDD and BD II depression in both their depressed and euthymic state.

Design, synthesis, spectral characterization, DNA interaction and biological activity studies of copper(II), cobalt(II) and nickel(II) complexes of 6-amino benzothiazole derivatives

NASA Astrophysics Data System (ADS)

Daravath, Sreenu; Kumar, Marri Pradeep; Rambabu, Aveli; Vamsikrishna, Narendrula; Ganji, Nirmala; Shivaraj

2017-09-01

Two novel Schiff bases, L1 = (2-benzo[d]thiazol-6-ylimino)methyl)-4,6-dichlorophenol), L2 = (1-benzo[d]thiazol-6-ylimino)methyl)-6-bromo-4-chlorophenol) and their bivalent transition metal complexes [M(L1)2] and [M(L2)2], where M = Cu(II), Co(II) and Ni(II) were synthesized and characterized by elemental analysis, NMR, IR, UV-visible, mass, magnetic moments, ESR, TGA, SEM, EDX and powder XRD. Based on the experimental data a square planar geometry around the metal ion is assigned to all the complexes (1a-2c). The interaction of synthesized metal complexes with calf thymus DNA was explored using UV-visible absorption spectra, fluorescence and viscosity measurements. The experimental evidence indicated that all the metal complexes strongly bound to CT-DNA through an intercalation mode. DNA cleavage experiments of metal(II) complexes with supercoiled pBR322 DNA have also been explored by gel electrophoresis in the presence of H2O2 as well as UV light, and it is found that the Cu(II) complexes cleaved DNA more effectively compared to Co(II), Ni(II) complexes. In addition, the ligands and their metal complexes were screened for antimicrobial activity and it is found that all the metal complexes were more potent than free ligands.

Carnitine palmitoyltransferase II deficiency

PubMed Central

Roe, C R.; Yang, B-Z; Brunengraber, H; Roe, D S.; Wallace, M; Garritson, B K.

2008-01-01

Background: Carnitine palmitoyltransferase II (CPT II) deficiency is an important cause of recurrent rhabdomyolysis in children and adults. Current treatment includes dietary fat restriction, with increased carbohydrate intake and exercise restriction to avoid muscle pain and rhabdomyolysis. Methods: CPT II enzyme assay, DNA mutation analysis, quantitative analysis of acylcarnitines in blood and cultured fibroblasts, urinary organic acids, the standardized 36-item Short-Form Health Status survey (SF-36) version 2, and bioelectric impedance for body fat composition. Diet treatment with triheptanoin at 30% to 35% of total daily caloric intake was used for all patients. Results: Seven patients with CPT II deficiency were studied from 7 to 61 months on the triheptanoin (anaplerotic) diet. Five had previous episodes of rhabdomyolysis requiring hospitalizations and muscle pain on exertion prior to the diet (two younger patients had not had rhabdomyolysis). While on the diet, only two patients experienced mild muscle pain with exercise. During short periods of noncompliance, two patients experienced rhabdomyolysis with exercise. None experienced rhabdomyolysis or hospitalizations while on the diet. All patients returned to normal physical activities including strenuous sports. Exercise restriction was eliminated. Previously abnormal SF-36 physical composite scores returned to normal levels that persisted for the duration of the therapy in all five symptomatic patients. Conclusions: The triheptanoin diet seems to be an effective therapy for adult-onset carnitine palmitoyltransferase II deficiency. GLOSSARY ALT = alanine aminotransferase; AST = aspartate aminotransferase; ATP = adenosine triphosphate; BHP = β-hydroxypentanoate; BKP = β-ketopentanoate; BKP-CoA = β-ketopentanoyl–coenzyme A; BUN = blood urea nitrogen; CAC = citric acid cycle; CoA = coenzyme A; CPK = creatine phosphokinase; CPT II = carnitine palmitoyltransferase II; LDL = low-density lipoprotein; MCT

EBR-II Data Digitization

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

Yoon, Su-Jong; Rabiti, Cristian; Sackett, John

2014-08-01

1. Objectives To produce a validation database out of those recorded signals it will be necessary also to identify the documents need to reconstruct the status of reactor at the time of the beginning of the recordings. This should comprehends the core loading specification (assemblies type and location and burn-up) along with this data the assemblies drawings and the core drawings will be identified. The first task of the project will be identify the location of the sensors, with respect the reactor plant layout, and the physical quantities recorded by the Experimental Breeder Reactor-II (EBR-II) data acquisition system. This firstmore » task will allow guiding and prioritizing the selection of drawings needed to numerically reproduce those signals. 1.1 Scopes and Deliverables The deliverables of this project are the list of sensors in EBR-II system, the identification of storing location of those sensors, identification of a core isotopic composition at the moment of the start of system recording. Information of the sensors in EBR-II reactor system was summarized from the EBR-II system design descriptions listed in Section 1.2.« less

Digital optical computer II

NASA Astrophysics Data System (ADS)

Guilfoyle, Peter S.; Stone, Richard V.

1991-12-01

OptiComp is currently completing a 32-bit, fully programmable digital optical computer (DOC II) that is designed to operate in a UNIX environment running RISC microcode. OptiComp's DOC II architecture is focused toward parallel microcode implementation where data is input in a dual rail format. By exploiting the physical principals inherent to optics (speed and low power consumption), an architectural balance of optical interconnects and software code efficiency can be achieved including high fan-in and fan-out. OptiComp's DOC II program is jointly sponsored by the Office of Naval Research (ONR), the Strategic Defense Initiative Office (SDIO), NASA space station group and Rome Laboratory (USAF). This paper not only describes the motivational basis behind DOC II but also provides an optical overview and architectural summary of the device that allows the emulation of any digital instruction set.

Glutathione Complex Formation With Mercury(Ii) in Aqueous Solution at Physiological Ph

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

Mah, V.; Jalilehvand, F.; /SLAC

2012-08-23

The mercury(II) complexes formed in neutral aqueous solution with glutathione (GSH, here denoted AH{sub 3} in its triprotonated form) were studied using Hg L{sub III}-edge extended X-ray absorption fine structure (EXAFS) and {sup 199}Hg NMR spectroscopy, complemented with electrospray ionization mass spectrometric (ESI-MS) analyses. The [Hg(AH){sub 2}]{sup 2-} complex, with the Hg-S bond distances at 2.325 {+-} 0.01 {angstrom} in linear S-Hg-S coordination, and the {sup 199}Hg NMR chemical shift at -984 ppm, dominates except at high excess of glutathione. In a series of solutions with C{sub Hg(II)} {approx} 17 mM and GSH/Hg(II) mole ratios rising from 2.4 to 11.8,more » the gradually increasing mean Hg-S bond distance corresponds to an increasing amount of the [Hg(AH){sub 3}]{sup 4-} complex. ESI-MS peaks appear at -m/z values of 1208 and 1230 corresponding to the [Na{sub 4}Hg(AH){sub 2}(A)]{sup -} and [Na{sub 5}Hg(AH)(A){sub 2}]{sup -} species, respectively. In another series of solutions at pH 7.0 with CHg(II) 50 mM and GSH/Hg(II) ratios from 2.0 to 10.0, the Hg L{sub III}-edge EXAFS and {sup 199}Hg NMR spectra show that at high excess of glutathione (0.35 M) about 70% of the total mercury(II) concentration is present as the [Hg(AH){sub 3}]4- complex, with the average Hg-S bond distance 2.42 {+-} 0.02 {angstrom} in trigonal HgS{sub 3} coordination. The proportions of HgSn species, n = 2, 3, and 4, quantified by fitting linear combinations of model EXAFS oscillations to the experimental EXAFS data in our present and previous studies were used to obtain stability constants for the [Hg(AH){sub 3}]{sup 4-} complex and also for the [Hg(A){sub 4}]{sup 10-} complex that is present at high pH. For Hg(II) in low concentration at physiological conditions (pH 7.4, C{sub GSH} = 2.2 mM), the relative amounts of the HgS{sub 2} species [Hg(AH){sub 2}]{sup 2-}, [Hg(AH)(A)]{sup 3-}, and the HgS{sub 3} complex [Hg(AH){sub 3}]{sup 4-} were calculated to be 95:2:3. Our results are

Nsls-II Boster

NASA Astrophysics Data System (ADS)

Gurov, S. M.; Akimov, A. V.; Akimov, V. E.; Anashin, V. V.; Anchugov, O. V.; Baranov, G. N.; Batrakov, A. M.; Belikov, O. V.; Bekhtenev, E. A.; Blum, E.; Bulatov, A. V.; Burenkov, D. B.; Cheblakov, P. B.; Chernyakin, A. D.; Cheskidov, V. G.; Churkin, I. N.; Davidsavier, M.; Derbenev, A. A.; Erokhin, A. I.; Fliller, R. P.; Fulkerson, M.; Gorchakov, K. M.; Ganetis, G.; Gao, F.; Gurov, D. S.; Hseuh, H.; Hu, Y.; Johanson, M.; Kadyrov, R. A.; Karnaev, S. E.; Karpov, G. V.; Kiselev, V. A.; Kobets, V. V.; Konstantinov, V. M.; Kolmogorov, V. V.; Korepanov, A. A.; Kramer, S.; Krasnov, A. A.; Kremnev, A. A.; Kuper, E. A.; Kuzminykh, V. S.; Levichev, E. B.; Li, Y.; Long, J. De; Makeev, A. V.; Mamkin, V. R.; Medvedko, A. S.; Meshkov, O. I.; Nefedov, N. B.; Neyfeld, V. V.; Okunev, I. N.; Ozaki, S.; Padrazo, D.; Petrov, V. V.; Petrichenkov, M. V.; Philipchenko, A. V.; Polyansky, A. V.; Pureskin, D. N.; Rakhimov, A. R.; Rose, J.; Ruvinskiy, S. I.; Rybitskaya, T. V.; Sazonov, N. V.; Schegolev, L. M.; Semenov, A. M.; Semenov, E. P.; Senkov, D. V.; Serdakov, L. E.; Serednyakov, S. S.; Shaftan, T. V.; Sharma, S.; Shichkov, D. S.; Shiyankov, S. V.; Shvedov, D. A.; Simonov, E. A.; Singh, O.; Sinyatkin, S. V.; Smaluk, V. V.; Sukhanov, A. V.; Tian, Y.; Tsukanova, L. A.; Vakhrushev, R. V.; Vobly, P. D.; Utkin, A. V.; Wang, G.; Wahl, W.; Willeke, F.; Yaminov, K. R.; Yong, H.; Zhuravlev, A.; Zuhoski, P.

The National Synchrotron Light Source II is a third generation light source, which was constructed at Brookhaven National Laboratory. This project includes a highly-optimized 3 GeV electron storage ring, linac preinjector, and full-energy synchrotron injector. Budker Institute of Nuclear Physics built and delivered the booster for NSLS-II. The commissioning of the booster was successfully completed. This paper reviews fulfilled work by participants.

Neuroprotective Effects and Mechanisms of Curcumin-Cu(II) and -Zn(II) Complexes Systems and Their Pharmacological Implications.

PubMed

Yan, Fa-Shun; Sun, Jian-Long; Xie, Wen-Hai; Shen, Liang; Ji, Hong-Fang

2017-12-28

Alzheimer's disease (AD) is the main form of dementia and has a steadily increasing prevalence. As both oxidative stress and metal homeostasis are involved in the pathogenesis of AD, it would be interesting to develop a dual function agent, targeting the two factors. Curcumin, a natural compound isolated from the rhizome of Curcuma longa , is an antioxidant and can also chelate metal ions. Whether the complexes of curcumin with metal ions possess neuroprotective effects has not been evaluated. Therefore, the present study was designed to investigate the protective effects of the complexes of curcumin with Cu(II) or Zn(II) on hydrogen peroxide (H₂O₂)-induced injury and the underlying molecular mechanisms. The use of rat pheochromocytoma (PC12) cells, a widely used neuronal cell model system, was adopted. It was revealed that curcumin-Cu(II) complexes systems possessed enhanced O₂ ·- -scavenging activities compared to unchelated curcumin. In comparison with unchelated curcumin, the protective effects of curcumin-Cu(II) complexes systems were stronger than curcumin-Zn(II) system. Curcumin-Cu(II) or -Zn(II) complexes systems significantly enhanced the superoxide dismutase, catalase, and glutathione peroxidase activities and attenuated the increase of malondialdehyde levels and caspase-3 and caspase-9 activities, in a dose-dependent manner. The curcumin-Cu(II) complex system with a 2:1 ratio exhibited the most significant effect. Further mechanistic study demonstrated that curcumin-Cu(II) or -Zn(II) complexes systems inhibited cell apoptosis via downregulating the nuclear factor κB (NF-κB) pathway and upregulating Bcl-2/Bax pathway. In summary, the present study found that curcumin-Cu(II) or -Zn(II) complexes systems, especially the former, possess significant neuroprotective effects, which indicates the potential advantage of curcumin as a promising agent against AD and deserves further study.

Spectroscopic Confirmation of the Dwarf Galaxies Hydra II and Pisces II and the Globular Cluster Laevens 1

NASA Astrophysics Data System (ADS)

Kirby, Evan N.; Simon, Joshua D.; Cohen, Judith G.

2015-09-01

We present Keck/DEIMOS spectroscopy of stars in the recently discovered Milky Way satellites Hydra II, Pisces II, and Laevens 1. We measured a velocity dispersion of {5.4}-2.4+3.6 km s-1 for Pisces II, but we did not resolve the velocity dispersions of Hydra II or Laevens 1. We marginally resolved the metallicity dispersions of Hydra II and Pisces II but not Laevens 1. Furthermore, Hydra II and Pisces II obey the luminosity-metallicity relation for Milky Way dwarf galaxies (< [{Fe}/{{H}}]> =-2.02+/- 0.08 and -2.45+/- 0.07, respectively), whereas Laevens 1 does not (< [{Fe}/{{H}}]> =-1.68+/- 0.05). The kinematic and chemical properties suggest that Hydra II and Pisces II are dwarf galaxies, and Laevens 1 is a globular cluster. We determined that two of the previously observed blue stars near the center of Laevens 1 are not members of the cluster. A third blue star has ambiguous membership. Hydra II has a radial velocity < {v}{helio}> =303.1+/- 1.4 km s-1, similar to the leading arm of the Magellanic stream. The mass-to-light ratio for Pisces II is {370}-240+310 {M}⊙ /{L}⊙ . It is not among the most dark matter-dominated dwarf galaxies, but it is still worthy of inclusion in the search for gamma-rays from dark matter self-annihilation. The data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Structure and spectroscopic investigations of a bi-dentate N‧-[(4-ethylphenyl)methylidene]-4-hydroxybenzohydrazide and its Co(II), Ni(II), Cu(II) and Cd(II) complexes: Insights relevant to biological properties

NASA Astrophysics Data System (ADS)

Gopal Reddy, N. B.; Krishna, P. Murali; Shantha Kumar, S. S.; Patil, Yogesh P.; Nethaji, Munirathinam

2017-06-01

The present paper describes the synthesis of novel ligand, N‧-[(4-ethylphenyl)methylidene]-4-hydroxy benzohydrazide (HL) and its Co(II), Ni(II), Cu(II) and Cd(II) complexes. The ligand (HL) crystallizes in orthorhombic lattice in P212121 space group with a = 7.9941 (7) Å, b = 11.6154 (10) Å, c = 15.2278 (13) Å, α = β = γ = 90°. Spectroscopic data gives the strong evidence that ligand is coordinated through azomethine nitrogen and enolic oxygen with metal ion. The DNA binding studies revealed that the complexes bind to CT-DNA via intercalation/electrostatic interaction. All the targeted compounds showed more pronounced DNA cleavage activity in the presence of H2O2 and also inhibit the growth of in vitro antibacterial activity against Gram-positive and Gram-negative bacteria.

Alternate Operating Scenarios for NDCX-II

NASA Astrophysics Data System (ADS)

Sharp, W. M.; Friedman, A.; Grote, D. P.; Cohen, R. H.; Lund, S. M.; Vay, J.-L.; Waldron, W. L.; Yeun, A.

2011-10-01

NDCX-II is an accelerator facility being built at LBNL to study ion-heated warm dense matter and aspects of ion-driven targets for inertial-fusion energy. The baseline design calls for using twelve induction cells to accelerate 40 nC of Li+ ions to 1.2 MeV. During commissioning, though, we plan to extend the source lifetime by extracting less total charge. For operational flexibility, the option of using a helium plasma source is also being investigated. Over time, we expect that NDCX-II will be upgraded to substantially higher energies, necessitating the use of heavier ions to keep a suitable deposition range in targets. Each of these options requires development of an alternate acceleration schedule and the associated transverse focusing. The schedules here are first worked out with a fast-running 1-D particle-in-cell code ASP, then 2-D and 3-D Warp simulations are used to verify the 1-D results and to design transverse focusing. Work performed under the auspices of U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344 and by LBNL under Contract DE-AC03-76SF00098.

Mo/Si multilayers with enhanced TiO II- and RuO II-capping layers

NASA Astrophysics Data System (ADS)

Yulin, Sergiy; Benoit, Nicolas; Feigl, Torsten; Kaiser, Norbert; Fang, Ming; Chandhok, Manish

2008-03-01

The lifetime of Mo/Si multilayer-coated projection optics is one of the outstanding issues on the road of commercialization of extreme-ultraviolet lithography (EUVL). The application of Mo/Si multilayer optics in EUVL requires both sufficient radiation stability and also the highest possible normal-incidence reflectivity. A serious problem of conventional high-reflective Mo/Si multilayers capped by silicon is the considerable degradation of reflective properties due to carbonization and oxidation of the silicon surface layer under exposure by EUV radiation. In this study, we focus on titanium dioxide (TiO II) and ruthenium dioxide (RuO II) as promising capping layer materials for EUVL multilayer coatings. The multilayer designs as well as the deposition parameters of the Mo/Si systems with different capping layers were optimized in terms of maximum peak reflectivity at the wavelength of 13.5 nm and longterm stability under high-intensive irradiation. Optimized TiO II-capped Mo/Si multilayer mirrors with an initial reflectivity of 67.0% presented a reflectivity drop of 0.6% after an irradiation dose of 760 J/mm2. The reflectivity drop was explained by the partial oxidation of the silicon sub-layer. No reflectivity loss after similar irradiation dose was found for RuO II-capped Mo/Si multilayer mirrors having initial peak reflectivity of 66%. In this paper we present data on improved reflectivity of interface-engineered TiO II- and RuO II-capped Mo/Si multilayer mirrors due to the minimization of both interdiffusion processes inside the multilayer stack and absorption loss in the oxide layer. Reflectivities of 68.5% at the wavelength of 13.4 nm were achieved for both TiO II- and RuO II-capped Mo/Si multilayer mirrors.

A comparative study of chelating and cationic ion exchange resins for the removal of palladium(II) complexes from acidic chloride media.

PubMed

Hubicki, Zbigniew; Wołowicz, Anna

2009-05-30

The increasing demand for palladium for technological application requires the development of ion exchange chromatography. Recently ion exchange chromatography has developed largely as a result of new types of ion exchangers available on the market of which two types are widely applied. One of them are selective (chelating) and modified ion exchangers and the other one are liquid exchangers. Two types of ion exchange resins such as chelating (Lewatit TP 214, Purolite S 920) and cationic (Chelite S, Duolite GT 73) ion exchangers are used for the recovery of palladium(II) complexes from chloride media (0.1-2.0M HCl-1.0M NaCl-0.0011 M Pd(II); 0.1-2.0M HCl-2.0M NaCl-0.0011M Pd(II)). The influence of concentration of hydrochloric acid, sodium chloride as well as the phase contact time on the degree of recovery of palladium(II) complexes was studied. Moreover, the amount of palladium(II) chlorocomplexes sorbed onto ion exchangers, the working ion exchange capacities and the weight and bed distribution coefficients were calculated in order to judge which of two types of resins possesses the best performance towards palladium(II) complexes.

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

Physical properties of solar chromospheric plages. III - Models based on Ca II and Mg II observations

NASA Technical Reports Server (NTRS)

Kelch, W. L.; Linsky, J. L.

1978-01-01

Solar plages are modeled using observations of both the Ca II K and the Mg II h and k lines. A partial-redistribution approach is employed for calculating the line profiles on the basis of a grid of five model chromospheres. The computed integrated emission intensities for the five atmospheric models are compared with observations of six regions on the sun as well as with models of active-chromosphere stars. It is concluded that the basic plage model grid proposed by Shine and Linsky (1974) is still valid when the Mg II lines are included in the analysis and the Ca II and Mg II lines are analyzed using partial-redistribution diagnostics.

Integrated Procurement Management System, Version II

NASA Technical Reports Server (NTRS)

Collier, L. J.

1985-01-01

Integrated Procurement Management System, Version II (IPMS II) is online/ batch system for collecting developing, managing and disseminating procurementrelated data at NASA Johnson Space Center. Portions of IPMS II adaptable to other procurement situations.

Influence of humic acid on adsorption of Hg(II) by vermiculite.

PubMed

do Nascimento, Fernando Henrique; Masini, Jorge Cesar

2014-10-01

Geochemical mobility of Hg(II) species is strongly affected by the interactions of these compounds with naturally occurring adsorbents such as humic acids, clay minerals, oxides, etc. Interactions among these sorbents affect their affinity for Hg(II) and a full understanding of these processes is still lacking. The present work describes the influence of a humic acid (HA) sample on the adsorption of Hg(II) by vermiculite (VT). Adsorption isotherms were constructed to evaluate the affinity of Hg(II) by VT, HA, VT modified with humic acid (VT-HA), and VT-HA in presence of soluble humic acid (VT-HA + HA). All experiments were made at pH 6.0 ± 0.1 in 0.02 M NaNO3 and 25.0 ± 0.5 °C for initial Hg(II) concentrations from 1.0 to 100 μM. Determinations of Hg(II) were made by square wave voltammetry automated by sequential injection analysis, an approach that enables the determination of the free plus labile fractions of Hg(II) in HA suspensions without the need for laborious separation steps. The adsorption isotherms were fitted to Langmuir and Freundlich equations, showing that HA was the material with the higher adsorption capacity (537 ± 30 μmol g(-1)) in comparison with VT and VT-HA (44 ± 3 and 51 ± 11 μmol g(-1), respectively). Adsorption order was HA > VT-HA + HA > VT = VT-HA. At pH 6.0 the interaction of HA with VT is weak and only 14% of C initially added to the suspension was effectively retained by the mineral. Desorption of Hg(II) in acidic medium (0.05 M HCl) was higher in binary (VT-HA) and ternary (VT-HA + HA) systems in comparison with that of VT and HA alone, suggesting that interactions between VT and HA are facilitated in acidic medium, weakening the binding to Hg(II). Copyright © 2014 Elsevier Ltd. All rights reserved.

AT2 DS II - Accelerator System Design (Part II) - CCC Video Conference

ScienceCinema

None

2017-12-09

Discussion Session - Accelerator System Design (Part II) Tutors: C. Darve, J. Weisend II, Ph. Lebrun, A. Dabrowski, U. Raich Video Conference with the CERN Control Center. Experts in the field of Accelerator science will be available to answer the students questions. This session will link the CCC and SA (using Codec VC).

Mammalian Toxicity of Munition Compounds. Phase II. Effects of Multiple Doses. Part III. 2,6-Dinitrotoluene

DTIC Science & Technology

1976-07-01

Histopathology , Statistical Analysis, and Normal Values ..... ...... ........... 131 I Ii A.mmALIAN TOXICITY OF MUNITION COMPOUNDS PHASE II: Effects of...chemistry tests and histopathology , and the normal values are given in Appendix I. The concentrations of Ca 2+, Mg2 +, Na+ and K+ in serum were determined...mice fed 2,6-DNT included focal epicarditis or myocarditis, focal cystitis, chronic murine pneumonia or bronchopneumonia, metritis and focal myositis

Nickel(II) Inhibits Tet-Mediated 5-Methylcytosine Oxidation by High Affinity Displacement of the Cofactor Iron(II).

PubMed

Yin, Ruichuan; Mo, Jiezhen; Dai, Jiayin; Wang, Hailin

2017-06-16

Ten-eleven translocation (Tet) family proteins are Fe(II)- and 2-oxoglutarate-dependent dioxygenases that regulate the dynamics of DNA methylation by catalyzing the oxidation of DNA 5-methylcytosine (5mC). To exert physiologically important functions, redox-active iron chelated in the catalytic center of Tet proteins directly involves the oxidation of the multiple substrates. To understand the function and interaction network of Tet dioxygenases, it is interesting to obtain high affinity and a specific inhibitor. Surprisingly, here we found that natural Ni(II) ion can bind to the Fe(II)-chelating motif (HXD) with an affinity of 7.5-fold as high as Fe(II). Consistently, we further found that Ni(II) ion can displace the cofactor Fe(II) of Tet dioxygenases and inhibit Tet-mediated 5mC oxidation activity with an estimated IC 50 of 1.2 μM. Essentially, Ni(II) can be used as a high affinity and selective inhibitor to explore the function and dynamics of Tet proteins.

Effective simultaneous removal of Pb(II) and Cd(II) ions by a new magnetic zeolite prepared from stem sweep

NASA Astrophysics Data System (ADS)

Safinejad, A.; Goudarzi, N.; Arab Chamjangali, M.; Bagherian, G.

2017-11-01

In this work, we prepared a new magnetic zeolite (MZ), as a sorbent, from stem sweep and used for the removal of lead and cadmium ions from aqueous solutions. Then the effective parameters involved in the removal efficiency of the studied ions were investigated. The synthetic MZ was characterized using x-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM). The best conditions for the preparation of MZ were found to be as follow: %Fe3O4 loaded  =  25, Si/Al  =  1.5, Na2O/SiO2  =  2.0, H2O/Na2O  =  75.0, crystallization time  =  20.0 h, and crystallization temperature  =  110 °C. The magnetic adsorbent was obtained by coating the zeolite with iron oxide nanoparticles. To study the sorption performance of the synthetic adsorbent, the single and binary systems including Pb(II) and Cd(II) ions were used. The effects of various parameters such as the solution pH, initial metal ion concentrations, amount of adsorbent, and contact time on the removal efficiency of the metal ions were studied. The results obtained showed that the adsorption isotherm data fitted well to the Langmuir isotherm, and that the adsorption kinetics of the metal ions in a binary system followed a pseudo-second order kinetic model.

An alkaline tin(II) halide compound Na{sub 3}Sn{sub 2}F{sub 6}Cl: Synthesis, structure, and characterization

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

Gong, Pifu; University of the Chinese Academy of Sciences, Beijing 100049; Luo, Siyang

A new alkali tin(II) halide compound, Na{sub 3}Sn{sub 2}F{sub 6}Cl, is synthesized by hydrothermal method. This compound crystallizes trigonally in space group of R-3c (167), and processes a zero-dimensional (0D) structure consisted of Na{sup +} cations, Cl{sup −} anions and the isolated [SnF{sub 3}]{sup -} trigonal pyramids in which the stereochemically active 5s{sup 2} lone pair electrons are attached to the Sn{sup 2+} cations. Interestingly, the [SnF{sub 3}]{sup −} trigonal pyramids are parallel arranged in the a-b plane, while oppositely arranged in line with rotation along the c- axis. Moreover, the energy bandgap, thermal stability and electronic structure of Na{submore » 3}Sn{sub 2}F{sub 6}Cl are characterized and the results reveal that this compound has and indirect bandgap of 3.88 eV and is stable under 270 °C. - Graphical abstract: A zero-dimensional alkaline tin halide compound, Na{sub 3}Sn{sub 2}F{sub 6}Cl, is synthesized by hydrothermal method. Interestingly, both the anions and cations coordinating polyhedra exhibit order arranged with the [SnF{sub 3}]{sup -} trigonal pyramids rotating along the c- axis.« less

BASS-II Hardware Repair

NASA Image and Video Library

2014-03-27

ISS039-E-005726 (27 March 2014) --- Expedition 39 Flight Engineer Rick Mastracchio performs inflight maintenance on an experiment called Burning and Suppression of Solids (BASS)-II. The investigation examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The BASS-II experiment will guide strategies for materials flammability screening for use in spacecraft as well as provide valuable data on solid fuel burning behavior in microgravity. BASS-II results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

Pd(II) and Pt(II) complexes of α-keto stabilized sulfur ylide: Synthesis, structural, theoretical and catalytic activity studies

NASA Astrophysics Data System (ADS)

Sabounchei, Seyyed Javad; Hashemi, Ali; Sedghi, Asieh; Bayat, Mehdi; Akhlaghi Bagherjeri, Fateme; Gable, Robert W.

2017-05-01

Reaction of dimethyl sulfide with 2, 3‧-dibromoacetophenone led to formation of sulfonium salt [Me2SCH2C(O)C6H4-m-Br]Br (1). The resulted sulfonium salt was treated with NaOH and gave the α-keto stabilized sulfur ylide Me2SC(H)C(O)C6H4-m-Br (2). This ligand was reacted with [MCl2(cod)] (M = Pd, Pt; cod = 1,5-cyclooctadiene) to form the new cis- and trans-[MCl2(ylide)2] (M = Pd (cis- and trans-3), Pt (cis- and trans-4)) complexes. Characterization of the obtained compounds was performed by elemental analysis, IR, 1H and 13C NMR. Recrystallization of dichlorobis(ylide) palladium(II) and platinum(II) complexes from DMSO solution yielded the crystalline products, which X-ray diffraction data revealed that the both compounds were crystallized as cis-[MCl2(ylide)(DMSO)] (M = Pd (5), Pt (6)) complexes. Also, a theoretical study on structure and nature of the Msbnd C bonding between the Y ligand (ylide) and [MCl2·DMSO] fragments in [YMCl2·DMSO] (M = Pd, Pt) complexes has been reported via NBO and energy-decomposition analysis (EDA). Furthermore, the palladium catalyzed Suzuki-Miyaura reaction of various aryl chlorides with arylboronic acids was performed. The results showed that the Pd(II) complexes cis- and trans-3 catalyzed efficiently coupling reactions at low catalyst loading and short reaction time.

Platinum(II) and palladium(II) complexes with 2-acetylpyridine thiosemicarbazone: cytogenetic and antineoplastic effects.

PubMed

Lakovidou, Z; Papageorgiou, A; Demertzis, M A; Mioglou, E; Mourelatos, D; Kotsis, A; Yadav, P N; Kovala-Demertzi, D

2001-01-01

The effect of three novel complexes of Pt(II) and three complexes of Pd(II) with 2-acetylpyridine thiosemicarbazone (HAcTsc) on sister chromatid exchange (SCE) rates and human lymphocyte proliferation kinetics on a molar basis was studied. Also, the effect of Pt(II) and Pd(II) complexes against leukemia P388 was investigated. Among these compounds, the most effective in inducing antitumor and cytogenetic effects were the complexes [Pt(AcTsc)2] x H2O and [Pd(AcTsc)2] while the rest, i.e. (HAcTsc), [Pt(AcTsc)Cl], [Pt(HAcTsc)2]Cl2 x 2H2O, [Pd(AcTsc)Cl] and [Pd(HAcTsc)2]Cl2, displayed marginal cytogenetic and antitumor effects.

Trident II (D-5) Sea Launched Ballistic Missile UGM 133A (Trident II Missile)

DTIC Science & Technology

2015-12-01

Selected Acquisition Report ( SAR ) RCS: DD-A&T(Q&A)823-178 Trident II (D-5) Sea-Launched Ballistic Missile UGM 133A (Trident II Missile) As of FY...December 2015 SAR March 17, 2016 12:10:33 UNCLASSIFIED 2 Table of Contents Common Acronyms and Abbreviations for MDAP Programs 3 Program...Acquisition Unit Cost Trident II Missile December 2015 SAR March 17, 2016 12:10:33 UNCLASSIFIED 3 PB - President’s Budget PE - Program Element PEO - Program

A series of tetraazalene radical-bridged M2 (M = CrIII, MnII, FeII, CoII) complexes with strong magnetic exchange coupling.

PubMed

DeGayner, Jordan A; Jeon, Ie-Rang; Harris, T David

2015-11-13

The ability of tetraazalene radical bridging ligands to mediate exceptionally strong magnetic exchange coupling across a range of transition metal complexes is demonstrated. The redox-active bridging ligand N , N ', N '', N '''-tetra(2-methylphenyl)-2,5-diamino-1,4-diiminobenzoquinone ( NMePh LH 2 ) was metalated to give the series of dinuclear complexes [(TPyA) 2 M 2 ( NMePh L 2- )] 2+ (TPyA = tris(2-pyridylmethyl)amine, M = Mn II , Fe II , Co II ). Variable-temperature dc magnetic susceptibility data for these complexes reveal the presence of weak superexchange interactions between metal centers, and fits to the data provide coupling constants of J = -1.64(1) and -2.16(2) cm -1 for M = Mn II and Fe II , respectively. One-electron reduction of the complexes affords the reduced analogues [(TPyA) 2 M 2 ( NMePh L 3- ˙)] + . Following a slightly different synthetic procedure, the related complex [(TPyA) 2 CrIII2( NMePh L 3- ˙)] 3+ was obtained. X-ray diffraction, cyclic voltammetry, and Mössbauer spectroscopy indicate the presence of radical NMePh L 3- ˙ bridging ligands in these complexes. Variable-temperature dc magnetic susceptibility data of the radical-bridged species reveal the presence of strong magnetic interactions between metal centers and ligand radicals, with simulations to data providing exchange constants of J = -626(7), -157(7), -307(9), and -396(16) cm -1 for M = Cr III , Mn II , Fe II , and Co II , respectively. Moreover, the strength of magnetic exchange in the radical-bridged complexes increases linearly with decreasing M-L bond distance in the oxidized analogues. Finally, ac magnetic susceptibility measurements reveal that [(TPyA) 2 Fe 2 ( NMePh L 3- ˙)] + behaves as a single-molecule magnet with a relaxation barrier of U eff = 52(1) cm -1 . These results highlight the ability of redox-active tetraazalene bridging ligands to enable dramatic enhancement of magnetic exchange coupling upon redox chemistry and provide a rare opportunity to examine

Modeling Fe II Emission and Revised Fe II (UV) Empirical Templates for the Seyfert 1 Galaxy I Zw 1

NASA Astrophysics Data System (ADS)

Bruhweiler, F.; Verner, E.

2008-03-01

We use the narrow-lined broad-line region (BLR) of the Seyfert 1 galaxy, I Zw 1, as a laboratory for modeling the ultraviolet (UV) Fe II 2100-3050 Å emission complex. We calculate a grid of Fe II emission spectra representative of BLR clouds and compare them with the observed I Zw 1 spectrum. Our predicted spectrum for log [nH/(cm -3) ] = 11.0, log [ΦH/(cm -2 s-1) ] = 20.5, and ξ/(1 km s-1) = 20, using Cloudy and an 830 level model atom for Fe II with energies up to 14.06 eV, gives a better fit to the UV Fe II emission than models with fewer levels. Our analysis indicates (1) the observed UV Fe II emission must be corrected for an underlying Fe II pseudocontinuum; (2) Fe II emission peaks can be misidentified as that of other ions in active galactic nuclei (AGNs) with narrow-lined BLRs possibly affecting deduced physical parameters; (3) the shape of 4200-4700 Å Fe II emission in I Zw 1 and other AGNs is a relative indicator of narrow-line region (NLR) and BLR Fe II emission; (4) predicted ratios of Lyα, C III], and Fe II emission relative to Mg II λ2800 agree with extinction corrected observed I Zw 1 fluxes, except for C IV λ1549 (5) the sensitivity of Fe II emission strength to microturbulence ξ casts doubt on existing relative Fe/Mg abundances derived from Fe II (UV)/Mg II flux ratios. Our calculated Fe II emission spectra, suitable for BLRs in AGNs, are available at http://iacs.cua.edu/people/verner/FeII. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 05-26555.

The Mg II h and k lines. II - Comparison with synthesized profiles and Ca II K. [solar spectra

NASA Technical Reports Server (NTRS)

Ayres, T. R.; Linsky, J. L.

1976-01-01

Measured high-dispersion center and limb profiles of the solar Mg II h and k resonance lines are compared with synthetic spectra computed with a partial-redistribution formalism and based on several upper-photosphere and lower-chromosphere temperature distributions. Profiles of the analogously formed Ca II K resonance line are also synthesized for the same atmospheric models. The spectrum-synthesis approach is outlined, and the collisional and fixed radiative rates appropriate to the adopted model atoms and solar atmosphere are discussed. It is found that the HSRA and VAL models predict systematically lower intensities in the h, k, and K inner wings than observed and that models with a somewhat higher minimum temperature (about 4450 K) can reproduce the measured inner wings and limb darkening. A 'Ca II' solar model with a minimum temperature of 4450 K is proposed as an alternative to the class of models based on continuum observations.

Synthesis of poly(aminopropyl/methyl)silsesquioxane particles as effective Cu(II) and Pb(II) adsorbents.

PubMed

Lu, Xin; Yin, Qiangfeng; Xin, Zhong; Li, Yang; Han, Ting

2011-11-30

Poly(aminopropyl/methyl)silsesquioxane (PAMSQ) particles have been synthesized by a one-step hydrolytic co-condensation process using 3-aminopropyltriethoxysilane (APTES) and methyltrimethoxysilane (MTMS) as precursors in the presence of base catalyst in aqueous medium. The amino functionalities of the particles could be controlled by adjusting the organosilanes feed ratio. The compositions of the amino-functionalized polysilsesquioxanes were confirmed by FT-IR spectroscopy, solid-state (29)Si NMR spectroscopy, and elemental analysis. The strong adsorbability of Cu(II) and Pb(II) ions onto PAMSQ particles was systematically examined. The effect of adsorption time, initial metal ions concentration and pH of solutions was studied to optimize the metal ions adsorbability of PAMSQ particles. The kinetic studies indicated that the adsorption process well fits the pseudo-second-order kinetics. Adsorption phenomena appeared to follow Langmuir isotherm. The PAMSQ particles demonstrate the highest Cu(II) and Pb(II) adsorption capacity of 2.29 mmol/g and 1.31 mmol/g at an initial metal ions concentration of 20mM, respectively. The PAMSQ particles demonstrate a promising application in the removal of Cu(II) and Pb(II) ions from aqueous solutions. Copyright © 2011 Elsevier B.V. All rights reserved.

Angiotensin II-induced hypertension blunts thick ascending limb NO production by reducing NO synthase 3 expression and enhancing threonine 495 phosphorylation

PubMed Central

Ramseyer, Vanesa D.; Gonzalez-Vicente, Agustin; Carretero, Oscar A.

2014-01-01

Thick ascending limbs reabsorb 30% of the filtered NaCl load. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl transport by this segment. In contrast, chronic angiotensin II (ANG II) infusion increases net thick ascending limb transport. NOS3 activity is regulated by changes in expression and phosphorylation at threonine 495 (T495) and serine 1177 (S1177), inhibitory and stimulatory sites, respectively. We hypothesized that NO production by thick ascending limbs is impaired by chronic ANG II infusion, due to reduced NOS3 expression, increased phosphorylation of T495, and decreased phosphorylation of S1177. Rats were infused with 200 ng·kg−1·min−1 ANG II or vehicle for 1 and 5 days. ANG II infusion for 5 days decreased NOS3 expression by 40 ± 12% (P < 0.007; n = 6) and increased T495 phosphorylation by 147 ± 26% (P < 0.008; n = 6). One-day ANG II infusion had no significant effect. NO production in response to endothelin-1 was blunted in thick ascending limbs from ANG II-infused animals [ANG II −0.01 ± 0.06 arbitrary fluorescence units (AFU)/min vs. 0.17 ± 0.02 AFU/min in controls; P < 0.01]. This was not due to reduced endothelin-1 receptor expression. Phosphatidylinositol 3,4,5-triphosphate (PIP3)-induced NO production was also reduced in ANG II-infused rats (ANG II −0.07 ± 0.06 vs. 0.13 ± 0.04 AFU/min in controls; P < 0.03), and this correlated with an impaired ability of PIP3 to increase S1177 phosphorylation. We conclude that in ANG II-induced hypertension NO production by thick ascending limbs is impaired due to decreased NOS3 expression and altered phosphorylation. PMID:25377910

Angiotensin II-induced hypertension blunts thick ascending limb NO production by reducing NO synthase 3 expression and enhancing threonine 495 phosphorylation.

PubMed

Ramseyer, Vanesa D; Gonzalez-Vicente, Agustin; Carretero, Oscar A; Garvin, Jeffrey L

2015-01-15

Thick ascending limbs reabsorb 30% of the filtered NaCl load. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl transport by this segment. In contrast, chronic angiotensin II (ANG II) infusion increases net thick ascending limb transport. NOS3 activity is regulated by changes in expression and phosphorylation at threonine 495 (T495) and serine 1177 (S1177), inhibitory and stimulatory sites, respectively. We hypothesized that NO production by thick ascending limbs is impaired by chronic ANG II infusion, due to reduced NOS3 expression, increased phosphorylation of T495, and decreased phosphorylation of S1177. Rats were infused with 200 ng·kg(-1)·min(-1) ANG II or vehicle for 1 and 5 days. ANG II infusion for 5 days decreased NOS3 expression by 40 ± 12% (P < 0.007; n = 6) and increased T495 phosphorylation by 147 ± 26% (P < 0.008; n = 6). One-day ANG II infusion had no significant effect. NO production in response to endothelin-1 was blunted in thick ascending limbs from ANG II-infused animals [ANG II -0.01 ± 0.06 arbitrary fluorescence units (AFU)/min vs. 0.17 ± 0.02 AFU/min in controls; P < 0.01]. This was not due to reduced endothelin-1 receptor expression. Phosphatidylinositol 3,4,5-triphosphate (PIP3)-induced NO production was also reduced in ANG II-infused rats (ANG II -0.07 ± 0.06 vs. 0.13 ± 0.04 AFU/min in controls; P < 0.03), and this correlated with an impaired ability of PIP3 to increase S1177 phosphorylation. We conclude that in ANG II-induced hypertension NO production by thick ascending limbs is impaired due to decreased NOS3 expression and altered phosphorylation. Copyright © 2015 the American Physiological Society.

MHC class II expression in lung cancer.

PubMed

He, Yayi; Rozeboom, Leslie; Rivard, Christopher J; Ellison, Kim; Dziadziuszko, Rafal; Yu, Hui; Zhou, Caicun; Hirsch, Fred R

2017-10-01

Immunotherapy is an exciting development in lung cancer research. In this study we described major histocompatibility complex (MHC) Class II protein expression in lung cancer cell lines and patient tissues. We studied MHC Class II (DP, DQ, DR) (CR3/43, Abcam) protein expression in 55 non-small cell lung cancer (NSCLC) cell lines, 42 small cell lung cancer (SCLC) cell lines and 278 lung cancer patient tissues by immunohistochemistry (IHC). Seven (12.7%) NSCLC cell lines were positive for MHC Class II. No SCLC cell lines were found to be MHC Class II positive. We assessed 139 lung cancer samples available in the Hirsch Lab for MHC Class II. There was no positive MHC Class II staining on SCLC tumor cells. MHC Class II expression on TILs in SCLC was significantly lower than that on TILs in NSCLC (P＜0.001). MHC Class II was also assessed in an additional 139 NSCLC tumor tissues from Medical University of Gdansk, Poland. Patients with positive staining of MHC Class II on TILs had longer regression-free survival (RFS) and overall survival (OS) than those whose TILs were MHC Class II negative (2.980 years, 95% CI 1.628-4.332 vs. 1.050 years, 95% CI 0.556-1.554, P=0.028) (3.230 years, 95% CI 2.617-3.843 vs. 1.390 years, 95% CI 0.629-2.151, P=0.014). MHC Class II was expressed both in NSCLC cell lines and tissues. However, MHC Class II was not detected in SCLC cell lines or tissue tumor cells. MHC Class II expression was lower on SCLC TILs than on NSCLC TILs. Loss of expression of MHC Class II on SCLC tumor cells and reduced expression on SCLC TILs may be a means of escaping anti-cancer immunity. Higher MHC Class II expression on TILs was correlated with better prognosis in patients with NSCLC. Copyright © 2017. Published by Elsevier B.V.

A forskolin derivative, colforsin daropate hydrochloride, inhibits the decrease in cortical renal blood flow induced by noradrenaline or angiotensin II in anesthetized rats.

PubMed

Ogata, Junichi; Minami, Kouichiro; Segawa, Kayoko; Uezono, Yasuhito; Shiraishi, Munehiro; Yamamoto, Chikako; Sata, Takeyoshi; Sung-Teh, Kim; Shigematsu, Akio

2004-01-01

A forskolin derivative, colforsin daropate hydrochloride (CDH), acts directly on adenylate cyclase to increase the intracellular cyclic adenosine monophosphate levels which produce a positive inotropic effect and a lower blood pressure. However, little is known about the effects of CDH on the renal function. We used laser Doppler flowmetry to measure the cortical renal blood flow (RBF) in male Wistar rats given a continuous intravenous infusion of CDH and evaluated the effects of CDH on the noradrenaline (NA) and angiotensin II (AngII) induced increases in blood pressure and reductions in RBF. Continuous intravenous administration of CDH at 0.25 microg/kg/min did not affect the mean arterial pressure (MAP), but increased heart rate and RBF. Continuous intravenous administration of CDH at high doses (0.5-0.75 microg/kg/min) decreased the MAP, with little effect on the RBF. The administration of exogenous NA (1.7 microg/kg) increased the MAP and decreased the RBF. However, a bolus injection of NA did not decrease the RBF during continuous intravenous administration of CDH, and CDH did not affect the NA-induced increase in MAP. The administration of exogenous AngII (100 ng/kg) increased MAP and decreased RBF and heart rate, but a bolus injection of AngII did not decrease RBF during continuous intravenous administration of CDH. These results suggest that CDH plays a protective role against the pressor effects and the decrease in RBF induced by NA or AngII. Copyright 2004 S. Karger AG, Basel

Common molecular determinants of tarantula huwentoxin-IV inhibition of Na+ channel voltage sensors in domains II and IV.

PubMed

Xiao, Yucheng; Jackson, James O; Liang, Songping; Cummins, Theodore R

2011-08-05

The voltage sensors of domains II and IV of sodium channels are important determinants of activation and inactivation, respectively. Animal toxins that alter electrophysiological excitability of muscles and neurons often modify sodium channel activation by selectively interacting with domain II and inactivation by selectively interacting with domain IV. This suggests that there may be substantial differences between the toxin-binding sites in these two important domains. Here we explore the ability of the tarantula huwentoxin-IV (HWTX-IV) to inhibit the activity of the domain II and IV voltage sensors. HWTX-IV is specific for domain II, and we identify five residues in the S1-S2 (Glu-753) and S3-S4 (Glu-811, Leu-814, Asp-816, and Glu-818) regions of domain II that are crucial for inhibition of activation by HWTX-IV. These data indicate that a single residue in the S3-S4 linker (Glu-818 in hNav1.7) is crucial for allowing HWTX-IV to interact with the other key residues and trap the voltage sensor in the closed configuration. Mutagenesis analysis indicates that the five corresponding residues in domain IV are all critical for endowing HWTX-IV with the ability to inhibit fast inactivation. Our data suggest that the toxin-binding motif in domain II is conserved in domain IV. Increasing our understanding of the molecular determinants of toxin interactions with voltage-gated sodium channels may permit development of enhanced isoform-specific voltage-gating modifiers.

Far Outer Galaxy H II Regions

NASA Technical Reports Server (NTRS)

Rudolph, A. L.; deGues, E. J.; Brand, J.; Wouterloot, J. G. A.; Gross, Anthony R. (Technical Monitor)

1994-01-01

We have made a multifrequency (6, 3.6, and 2 cm), high-resolution (3"-6"), radio continuum survey of IRAS selected sources from the catalogue of Wouterloot & Brand (1989) to search for and study H II regions in the far outer Galaxy. We identified 31 sources in this catalog with well determined galactocentric distances, and with R approx.. greater than 15 kpc and L(sub FIR) approx.greater than 10(exp 4) solar luminosity, indicating the presence of high-mass star-formation. We have observed 11 of these sources with the Very Large Array (VLA). We observed the sources at 6 and 2 cm using "scaled arrays", making possible a direct and reliable comparison of the data at these two wavelengths for the determination of spectral indices. We detected a total of 12 radio sources, of which 10 have spectral indices consistent with optically-thin free-free emission from H II regions. Combined with previous VLA observations by other investigators, we have data on a total of 15 H II regions at galactocentric distances of 15 to 18.2kpc, among the most remote H II regions found in our Galaxy. The sizes of the H II regions range from approx. less than 0.10 to 2.3 pc. Using the measured fluxes and sizes, we determine the electron densities, emission measures, and excitation parameters of the H II regions, as well as the fluxes of Lyman continuum photons needed to keep the nebulae ionized. The sizes and electron densities are consistent with most of the sources detected in this survey being compact or ultracompact H II regions. Seven of the fifteen H II regions have sizes approx. less than 0.20 pc. Assuming simple pressure-driven expansion of the H II regions, these sizes indicate ages approx. less than 5 x 10(exp 4) yr, or only 1% of the lifetime of an O star, which implies an unlikely overabundance of O stars in the outer Galaxy. Thus, the large number of compact H II regions suggests that the time these regions spend in a compact phase must be much longer than their dynamical

Sorption and desorption of Pb(II) to biochar as affected by oxidation and pH.

PubMed

Wang, Qian; Wang, Bing; Lee, Xinqing; Lehmann, Johannes; Gao, Bin

2018-09-01

The use of biochar for the removal of heavy metals from water has environmental benefits. In order to elucidate the potential application of highly functionalized biochar for the removal of Pb(II) in aqueous solution, maple wood biochar was oxidized using hydrogen peroxide. The pH values of oxidized biochar ranged from 8.1 to 3.7, with one set being adjusted to a pH of 7 as a comparison. It was found that oxidizing the biochars increased their Pb(II) adsorption capacity if the pH remained below 6 (strong oxidation), but decreased their Pb(II) adsorption ability above pH6 (weak oxidation). After adjusting the pH of oxidized biochar to pH7, the Pb(II) adsorption capacity further increased two to sixfold for oxidized biochars originally at pH3.7-6. The adsorption characteristics of Pb(II) were well described by the Langmuir equation. Adsorption of Pb(II) was not fully reversible in water. Less than 6% of Pb(II) desorbed in water in two consecutive steps than was previously adsorbed, for biochars with a pH below 7, irrespective of oxidation. Recovery using an extraction with 0.1M NaNO 3 increased from 0.7% to 32.7% of Pb(II) undesorbed by both preceding water extractions with increasing oxidation, for biochars with a pH below 7. Unextractable Pb(II) was lower at low oxidation but increased to 99.0% of initially adsorbed amounts at low pH, which indicated that the adsorption of Pb(II) on oxidized biochar is pH independent. Copyright © 2018 Elsevier B.V. All rights reserved.

Sorption and desorption of lead (II) from wastewater by green algae Cladophora fascicularis.

PubMed

Deng, Liping; Su, Yingying; Su, Hua; Wang, Xinting; Zhu, Xiaobin

2007-05-08

Biosorption is an effective method to remove heavy metals from wastewater. In this work, adsorption features of Cladophora fascicularis were investigated as a function of time, initial pH, initial Pb(II) concentrations, temperature and co-existing ions. Kinetics and equilibria were obtained from batch experiments. The biosorption kinetics followed the pseudo-second order model. Adsorption equilibria were well described by the Langmuir and Freundlich isotherm models. The maximum adsorption capacity was 198.5 mg/g at 298K and pH 5.0. The adsorption processes were endothermic and the biosorption heat was 29.6 kJ/mol. Desorption experiments indicated that 0.01 mol/L Na(2)EDTA was an efficient desorbent for the recovery of Pb(II) from biomass. IR spectrum analysis suggested amido or hydroxy, CO and C-O could combine intensively with Pb(II).

Host galaxy properties of calcium II and sodium I quasar absorption-line systems

NASA Astrophysics Data System (ADS)

Cherinka, Brian

Many questions remain within the areas of galaxy formation and evolution. Understanding the origin of gas in galaxy environments, whether as tidal debris, infalling High Velocity Clouds, galaxy outflows, or as gaseous material residing in galaxy disks, is an important step in answering those questions. Quasar absorption-lines can often be used to probe the environments of intervening galaxies. Traditionally, quasar absorption-lines are studied independently of the host galaxy but this method denies us the exploration of the connection between galaxy and environment. Instead, one can select pairs of known galaxies and quasars. This gives much more information regarding the host galaxy and allows us to better connect galaxy properties with associated absorbers. We use the seventh data release of the Sloan Digital Sky Survey to generate a sample of spectroscopic galaxy-quasar pairs. We cross-correlated a sample of 105,000 quasars and ˜800,000 galaxies to produce ˜98,000 galaxy-quasar pairs, with the quasar projected within 100 kpc of the galaxy. Adopting an automated line-finding algorithm and using the galaxy redshift as a prior, we search through all quasar spectra and identify Ca II and Na I absorption due to the intervening galaxy. This procedure produced 1745 Ca II absorbers and 4500 Na I absorbers detected at or above 2σ. Stacking analysis of a subset of absorbers at z > 0.01, with significances at or above 3σ, showed strong Ca II and Na I features around external galaxies. Using the same subset of absorbers at z > 0.01, we looked for correlations between absorber and galaxy properties and examined differences in galaxy properties between the absorbers and non-absorbers. We found no correlations with absorber strength or differences between many galaxy properties at the 3σ level. The lack of correlations and differences between absorbers and non-absorbers suggest a ubiquitous nature for Ca II and Na I around all types of galaxies, with the absorbers showing

Sorption Mechanisms of Cesium on Cu II2Fe II(CN) 6and Cu II3[Fe III(CN) 6] 2Hexacyanoferrates and Their Relation to the Crystalline Structure

NASA Astrophysics Data System (ADS)

Ayrault, S.; Jimenez, B.; Garnier, E.; Fedoroff, M.; Jones, D. J.; Loos-Neskovic, C.

1998-12-01

CuII2FeII(CN)6·xH2O and CuII3[FeIII(CN)6]2·xH2O can be prepared with reproducible chemical compositions and structures after careful washing. They have cubicFmoverline3mstructures with iron vacancies. In CuII2FeII(CN)6, copper occupies two different sites: Cu1 in position 4blinked to Fe through the CN groups, and Cu2 not linked to the CN groups and partially occupying the interstitial 24epositions. The second type of site is not present in CuII3[FeIII(CN)6]2. Sorption kinetics and isotherms were determined for cesium on both hexacyanoferrates by batch experiments. On CuII3[FeIII(CN)6]2, the maximum uptake is only 0.073 Cs/Fe (at./at.). On CuII2FeII(CN)6, the uptake reaches 1.5 Cs/Fe. The sorption kinetics include at least two steps: at1/2variation until approximately 72 h and then a slow evolution studied up to 6 months. The sorption mechanism is complex. The main process seems to be diffusion of ion pairs, followed by a reorganization of the solid, resulting in one or more new solid phases. The presence of the Cu2 site seems to play a favorable role in the sorption. Owing to its good midterm stability and the first rapid step of exchange, CuII2FeII(CN)6·xH2O seems to be one of the most promising compounds for the recovery of cesium from nuclear liquid wastes.

Spiral chain structure of high pressure selenium-II{sup '} and sulfur-II from powder x-ray diffraction

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

Fujihisa, Hiroshi; Yamawaki, Hiroshi; Sakashita, Mami

2004-10-01

The structure of high pressure phases, selenium-II{sup '} (Se-II{sup '}) and sulfur-II (S-II), for {alpha}-Se{sub 8} (monoclinic Se-I) and {alpha}-S{sub 8} (orthorhombic S-I) was studied by powder x-ray diffraction experiments. Se-II{sup '} and S-II were found to be isostructural and to belong to the tetragonal space group I4{sub 1}/acd, which is made up of 16 atoms in the unit cell. The structure consisted of unique spiral chains with both 4{sub 1} and 4{sub 3} screws. The results confirmed that the structure sequence of the pressure-induced phase transitions for the group VIb elements depended on the initial molecular form. The chemicalmore » bonds of the phases are also discussed from the interatomic distances that were obtained.« less

Extraction and separation of Co(II) and Ni(II) from acidic sulfate solutions using Aliquat 336.

PubMed

Nayl, A A

2010-01-15

Extraction and separation of Co(II) and Ni(II) from acidic sulfate solutions by solvent extraction technique were studied using different forms of Aliquat 336 diluted with kerosene. The extraction percent of each metal ion was found to increase with increasing pH and extractant concentration. Co(II) was preferentially extracted by different forms of Aliquat 336 over Ni(II) under the same extraction conditions. From analysis of the experimental results, the extraction mechanism of R(4)N-forms was proposed with Co(II). It was found that the highest separation factor (S(Co/Ni)) value of 606.7 was obtained with 0.36 M R(4)N-SCN in kerosene from 2.0M H(2)SO(4) solution at pH 4.8 and shaking time of 20 min. Stripping of the two metal ions from the organic phase was also investigated. Based on the experimental results, a separation method was developed and tested to separate high purity Co(II), Ni(II) and Ln(III) from Ni-MH batteries leached by 2.0M H(2)SO(4). Based on the experimental results, a flow sheet was developed and tested and 0.34 g Co, 1.39 g Ln and 5.2g Ni were obtained from the leaching process.

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.

MHC class II+ (HLA-DP-like) cells in the cow reproductive tract: II. Immunolocalization of MHC class II+ cells in oviduct and vagina.

PubMed

Eren, U; Kum, S; Sandikçi, M; Eren, V; Ilhan, F

2009-08-01

The aim of this study was to determine and examine the distribution of major frequency MHC II+ cells in the oviduct and vagina of cows during the oestrous and dioestrus phases. Right oviduct (ampulla, isthmus) and vaginal samples taken from a total of twenty seven multiparous cows were used. Tissue samples were processed to obtain both cryostat and paraffin sections. Sections were stained immunocytochemically using StreptABC method using a specific monoclonal antibody to MHC II+ cell population. Intra-epithelial and subepithelial areas along with lamina propria, muscularis mucosae and serosa of both ampulla and isthmus and intra-epithelial/subepithelial areas and mucosae of vagina were examined for the presence of MHC II+ cells. The density of immune positive cells was determined using a subjective scoring system. MHC II+ cells were demonstrated in all areas examined in both oestrus and dioestrus. In oestrus, the density of MHC II+ cells decreased in subepithelial areas (in between the epithelial cells and the basal membrane) of isthmus, whereas the density of immune positive cells was increased in muscularis mucosae of isthmus (P < 0.05), lamina propria and muscularis mucosae of ampulla (P < 0.05) as well as in the mucosae of vagina (P II+ cells observed in the oviduct and vagina increases in the majority of areas examined due to the effect of oestrogen.

Testicular gonadotropin-releasing hormone II receptor (GnRHR-II) knockdown constitutively impairs diurnal testosterone secretion in the boar

USDA-ARS?s Scientific Manuscript database

The second mammalian GnRH isoform (GnRH-II) and its specific receptor (GnRHR-II) are highly expressed in the testis, suggesting an important role in testis biology. Gene coding errors prevent the production of GnRH-II and GnRHR-II in many species, but both genes are functional in swine. We have demo...

Efficient removal of nickel(II) from high salinity wastewater by a novel PAA/ZIF-8/PVDF hybrid ultrafiltration membrane.

PubMed

Li, Ting; Zhang, Weiming; Zhai, Shu; Gao, Guandao; Ding, Jie; Zhang, Wenbin; Liu, Yang; Zhao, Xin; Pan, Bingcai; Lv, Lu

2018-06-15

The development of highly efficient membranes, especially those aimed at the removal of trace (ppm, 10 -6 ) heavy metals from high salinity wastewater, is one of the principal challenges in the wastewater treatment field. In this study, a new metal-organic frameworks-based hybrid ultrafiltration membrane (PAA/ZIF-8/PVDF membrane) was prepared, which outperformed some other adsorption materials and owned the first and highest reported nickel ion (Ni(II)) adsorption capacity (219.09 mg/g) in high salinity ([Na + ] = 15000 mg/L) wastewater. Novel and highly efficient hybrid ultrafiltration membrane was facilely fabricated by physically immobilizing zeolitic imidazolate framework-8 (ZIF-8) particles onto the surface of trimesoyl chloride (TMC)-modified polyvinylidene fluoride (PVDF) membrane under the protection of polyacrylic acid (PAA) layer, and possessed a relatively high water flux of ∼460 L m -2 h -1 . The XPS studies revealed that the Ni(II) uptake was mainly attributed to the specific hydrogen bonding interaction between Ni(II) and hydroxyl on ZIF-8 frameworks as well as the electrostatic adsorption by carboxyl groups in PAA layer. Especially, compared to PAA, ZIF-8 could selectively bind with Ni(II) effectively, which was almost not affected by concentrated sodium ion. The filtration study showed that the membrane with an area of 12.56 cm 2 could treat 5.76 L of Ni(II)-contained high salinity wastewater ([Ni(II) = 2 mg/L, [Na + ] = 15000 mg/L) to meet the maximum contaminant level of 0.1 mg/L Ni(II). Moreover, the hybrid membrane can be regenerated several times by HCl-NaCl solution (pH = 5.5) for repeated use under direct current electric field. Thus, the newly developed ZIF-8 hybrid ultrafiltration membrane showed a promising potential for heavy metals containing wastewater treatment. This work provides a worthy reference for designing highly efficient ultrafiltration membranes modified by metal-organic frameworks

Synthesis and thermal conductivity of type II silicon clathrates

NASA Astrophysics Data System (ADS)

Beekman, M.; Nolas, G. S.

2006-08-01

We have synthesized and characterized polycrystalline Na 1Si 136 and Na 8Si 136, compounds possessing the type II clathrate hydrate crystal structure. Resistivity measurements from 10 to 300 K indicate very large resistivities in this temperature range, with activated temperature dependences indicative of relatively large band gap semiconductors. The thermal conductivity is very low; two orders-of-magnitude lower than that of diamond-structure silicon at room temperature. The thermal conductivity of Na 8Si 136 displays a temperature dependence that is atypical of crystalline solids and more indicative of amorphous materials. This work is part of a continuing effort to explore the many different compositions and structure types of clathrates, a class of materials that continues to be of interest for scientific and technological applications.

Synthesis, characterization, thermal and biological evaluation of Cu (II), Co (II) and Ni (II) complexes of azo dye ligand containing sulfamethaxazole moiety

NASA Astrophysics Data System (ADS)

Mallikarjuna, N. M.; Keshavayya, J.; Maliyappa, M. R.; Shoukat Ali, R. A.; Venkatesh, Talavara

2018-08-01

A novel bioactive Cu (II), Co (II) and Ni (II) complexes of the azo dye ligand (L) derived from sulfamethoxazole were synthesized. The structures of the newly synthesized compounds were characterized by elemental analysis, molar conductance, magnetic susceptibility, FTIR, UV-visible, 1H NMR, mass, thermal and powder XRD spectral techniques. Molar conductivity measurements in DMSO solution confirmed the non-electrolytic nature of the complexes. All the synthesized metal complexes were found to be monomeric and showed square planar geometry except the Co (II) complex which has six coordinate, octahedral environment. The metal complexes have exhibited potential growth inhibitory effect against tested bacterial strains as compared to the free ligand. The ligand and complexes have also shown significant antioxidant and Calf Thymus DNA cleavage activities. Further, the in silico molecular docking studies were performed to predict the possible binding sites of the ligand (L) and its metal complexes with target receptor Glu-6P.

Effects of changes in sodium balance on plasma and kidney angiotensin II levels in anesthetized and conscious Ren-2 transgenic rats.

PubMed

Husková, Zuzana; Kramer, Herbert J; Vanourková, Zdenka; Cervenka, Ludek

2006-03-01

Since there is as yet no general agreement regarding the role of plasma and kidney angiotensin II (ANG II) in the development of hypertension in Ren-2 transgenic rats (TGR), in the present study we evaluated plasma and kidney ANG II levels in anesthetized and conscious TGR and in normotensive Hannover-Sprague-Dawley rats (HanSD) fed a normal salt diet (NS). Given the importance of ANG II in the development of salt-sensitive hypertension, and the fact that hypertensinogenic actions of ANG II are mediated via ANG II type 1 (AT1) receptors, the effects of high salt (HS) intake and of sodium depletion on blood pressure (BP), ANG II levels and kidney AT1 receptor protein expression in TGR and HanSD were also examined. Rats were maintained on a NS diet (0.6% NaCl) or fed a HS diet (2% NaCl) for 4 days or were sodium depleted (40 mg/l furosemide for 1 day followed by 3 days of 0.01% NaCl diet). They were sacrificed either by an overdose of anesthetic (thiopental sodium) or by decapitation (without anesthetic) and plasma and kidney ANG II levels were determined by radioimmunoassay during the prehypertensive (32 days old), the early (52 days) and the maintenance (90 days) phases of hypertension. Total kidney AT1 receptor protein levels were assessed by Western blot analysis. In anesthetized animals fed the NS diet, plasma ANG II levels were lower in 32-day-old TGR than in HanSD, but at 52 and 90 days of age no significant differences were noted. ANG II concentrations in kidney tissue were similar in 32- and 90-day-old TGR and HanSD, but were higher in 52-day-old TGR than in HanSD. In contrast, in conscious animals immediately after decapitation, plasma and kidney ANG II levels were higher in TGR than in HanSD at all ages. HS diet did not change BP but suppressed ANG II levels in HanSD at all ages. In contrast, HS diet increased BP but did not decrease plasma and kidney ANG II levels in TGR at all ages. Sodium restriction did not alter BP and resulted in a marked increase in

Uranium Reduction by Fe(II) in the Presence of Montmorillonite and Nontronite.

PubMed

Tsarev, Sergey; Waite, T David; Collins, Richard N

2016-08-02

Uranium(VI) interactions with three smectites (one montmorillonite and two nontronites - NAu1 and NAu2) were examined with 0, 1, and 2 mM aqueous concentrations of Fe(II) over the pH range of 3-9.5 in a background electrolyte of 100 mM NaCl and 1 mM CaCl2 in equilibration with 400 ppmv CO2(g) ([U(VI)] = 4 μM and 0.5 g smectite/L). In the absence of Fe(II), no differences were observed in the U(VI) sorption curves for the three clay minerals. In the presence of 1 or 2 mM Fe(II), under anoxic conditions, U(VI) uptake by the smectites changed slightly between ∼pH 3 and 6; however, uranium uptake increased significantly above ∼pH 6 and was proportional to the concentration of Fe(II) added to the system, particularly at pH values >8. The uptake of Fe(II) showed a sharp edge starting from ∼pH 6.5 with 95%-100% uptake occurring at pH values >7.5, with no difference observed between the iron-rich nontronites and montmorillonite. After 3 days of reaction at pH 7.6 (i.e., above the Fe(II) "sorption" edge), U(VI) was transformed to a mixture of U(IV) and U(VI) sorption complexes, and after 14 days of reaction, 100% of the U was found to be reduced to U(IV) in the form of nanocrystalline uraninite. In contrast, U remained as sorbed species until 14 days of reaction at pH 6.5. Ferrihydrite (NAu1), lepidocrocite, and magnetite (NAu2) were detected as secondary mineralization products upon reaction of the nontronites with Fe(II) but appeared to have no effect on the partitioning or speciation of uranium.

Removal of Pb(II) and Cd(II) from water by adsorption on peels of banana.

PubMed

Anwar, Jamil; Shafique, Umer; Waheed-uz-Zaman; Salman, Muhammad; Dar, Amara; Anwar, Shafique

2010-03-01

The adsorption of lead(II) and cadmium(II) on peels of banana has been studied in batch mode using flame atomic absorption spectroscopy for metal estimation. Concerned parameters like adsorbent dose, pH, contact time and agitation speed were investigated. Langmuir, Freundlich and Temkin isotherms were employed to describe adsorption equilibrium. The maximum amounts of cadmium(II) and lead(II) adsorbed (qm), as evaluated by Langmuir isotherm, were 5.71 mg and 2.18 mg per gram of powder of banana peels, respectively. Study concluded that banana peels, a waste material, have good potential as an adsorbent to remove toxic metals like lead and cadmium from water. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Structure and magnetism of a Mn(III)-Mn(II)-Mn(II)-Mn(III) chain complex.

PubMed

Uhrecký, Róbert; Moncoľ, Ján; Koman, Marian; Titiš, Ján; Boča, Roman

2013-07-14

A novel tetranuclear manganese(II/III) complex with anions of pyridine-2,6-dicarboxylic acid (dipicolinic acid) has been synthesised and magneto-structurally characterised. The crystal structure of [Mn(II)2Mn(III)2(dipic)6(H2O)4]·2CH3OH·4H2O has been determined by single-crystal X-ray diffraction. The tetranuclear complex molecule [Mn(II)2Mn(III)2(dipic)6(H2O)4] is centrosymmetric and two manganese(II) and two manganese(III) atoms are bridged by four dipicolinate ligands. The complex molecules and uncoordinated water and methanol molecules are connected through hydrogen bonds and they form a 3D supramolecular hydrogen-bonding network.

Zn(II)-coordination modulated ligand photophysical processes – the development of fluorescent indicators for imaging biological Zn(II) ions

PubMed Central

Yuan, Zhao; Simmons, J. Tyler; Sreenath, Kesavapillai

2014-01-01

Molecular photophysics and metal coordination chemistry are the two fundamental pillars that support the development of fluorescent cation indicators. In this article, we describe how Zn(II)-coordination alters various ligand-centered photophysical processes that are pertinent to developing Zn(II) indicators. The main aim is to show how small organic Zn(II) indicators work under the constraints of specific requirements, including Zn(II) detection range, photophysical requirements such as excitation energy and emission color, temporal and spatial resolutions in a heterogeneous intracellular environment, and fluorescence response selectivity between similar cations such as Zn(II) and Cd(II). In the last section, the biological questions that fluorescent Zn(II) indicators help to answer are described, which have been motivating and challenging this field of research. PMID:25071933

Relative abundance of chemical forms of Cu(II) and Cd(II) on soybean roots as influenced by pH, cations and organic acids

PubMed Central

Zhou, Qin; Liu, Zhao-dong; Liu, Yuan; Jiang, Jun; Xu, Ren-kou

2016-01-01

Little information is available on chemical forms of heavy metals on integrate plant roots. KNO3 (1 M), 0.05M EDTA at pH6 and 0.01 M HCl were used sequentially to extract the exchangeable, complexed and precipitated forms of Cu(II) and Cd(II) from soybean roots and then to investigate chemical form distribution of Cu(II) and Cd(II) on soybean roots. Cu(II) and Cd(II) adsorbed on soybean roots were mainly exchangeable form, followed by complexed form, while their precipitated forms were very low under acidic conditions. Soybean roots had a higher adsorption affinity to Cu(II) than Cd(II), leading to higher toxic of Cu(II) than Cd(II). An increase in solution pH increased negative charge on soybean and thus increased exchangeable Cu(II) and Cd(II) on the roots. Ca2+, Mg2+ and NH4+ reduced exchangeable Cu(II) and Cd(II) levels on soybean roots and these cations showed greater effects on Cd(II) than Cu(II) due to greater adsorption affinity of the roots to Cu(II) than Cd(II). L-malic and citric acids decreased exchangeable and complexed Cu(II) on soybean roots. In conclusion, Cu(II) and Cd(II) mainly existed as exchangeable and complexed forms on soybean roots. Ca2+ and Mg2+ cations and citric and L-malic acids can potentially alleviate Cu(II) and Cd(II) toxicity to plants. PMID:27805020

20 CFR 404.1340 - Wage credits for World War II and post-World War II veterans.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Wage credits for World War II and post-World... Uniformed Services Amounts of Wage Credits and Limits on Their Use § 404.1340 Wage credits for World War II and post-World War II veterans. In determining your entitlement to, and the amount of, your monthly...

20 CFR 404.1340 - Wage credits for World War II and post-World War II veterans.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Wage credits for World War II and post-World... Uniformed Services Amounts of Wage Credits and Limits on Their Use § 404.1340 Wage credits for World War II and post-World War II veterans. In determining your entitlement to, and the amount of, your monthly...

20 CFR 404.1340 - Wage credits for World War II and post-World War II veterans.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Wage credits for World War II and post-World... Uniformed Services Amounts of Wage Credits and Limits on Their Use § 404.1340 Wage credits for World War II and post-World War II veterans. In determining your entitlement to, and the amount of, your monthly...

20 CFR 404.1340 - Wage credits for World War II and post-World War II veterans.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Wage credits for World War II and post-World... Uniformed Services Amounts of Wage Credits and Limits on Their Use § 404.1340 Wage credits for World War II and post-World War II veterans. In determining your entitlement to, and the amount of, your monthly...

Markedly accelerated catabolism of apolipoprotein A-II (ApoA-II) and high density lipoproteins containing ApoA-II in classic lecithin: cholesterol acyltransferase deficiency and fish-eye disease.

PubMed Central

Rader, D J; Ikewaki, K; Duverger, N; Schmidt, H; Pritchard, H; Frohlich, J; Clerc, M; Dumon, M F; Fairwell, T; Zech, L

1994-01-01

Classic (complete) lecithin:cholesterol acyltransferase (LCAT) deficiency and Fish-eye disease (partial LCAT deficiency) are genetic syndromes associated with markedly decreased plasma levels of high density lipoprotein (HDL) cholesterol but not with an increased risk of atherosclerotic cardiovascular disease. We investigated the metabolism of the HDL apolipoproteins (apo) apoA-I and apoA-II in a total of five patients with LCAT deficiency, one with classic LCAT deficiency and four with Fish-eye disease. Plasma levels of apoA-II were decreased to a proportionately greater extent (23% of normal) than apoA-I (30% of normal). In addition, plasma concentrations of HDL particles containing both apoA-I and apoA-II (LpA-I:A-II) were much lower (18% of normal) than those of particles containing only apoA-I (LpA-I) (51% of normal). The metabolic basis for the low levels of apoA-II and LpA-I:A-II was investigated in all five patients using both exogenous radiotracer and endogenous stable isotope labeling techniques. The mean plasma residence time of apoA-I was decreased at 2.08 +/- 0.27 d (controls 4.74 +/- 0.65 days); however, the residence time of apoA-II was even shorter at 1.66 +/- 0.24 d (controls 5.25 +/- 0.61 d). In addition, the catabolism of apoA-I in LpA-I:A-II was substantially faster than that of apoA-I in LpA-I. In summary, genetic syndromes of either complete or partial LCAT deficiency result in low levels of HDL through preferential hypercatabolism of apoA-II and HDL particles containing apoA-II. Because LpA-I has been proposed to be more protective than LpA-I:A-II against atherosclerosis, this selective effect on the metabolism of LpA-I:A-II may provide a potential explanation why patients with classic LCAT deficiency and Fish-eye disease are not at increased risk for premature atherosclerosis despite markedly decreased levels of HDL cholesterol and apoA-I. PMID:8282802

Csk regulates angiotensin II-induced podocyte apoptosis.

PubMed

Zhang, Lu; Ren, Zhilong; Yang, Qian; Ding, Guohua

2016-07-01

Increasing data have shown that angiotensin II (Ang II) perpetuates podocyte injury and promotes progression to end-stage kidney disease. The mechanism underlying Ang II-induced podocyte apoptosis has not been established. C-terminal Src kinase (Csk) is a cytoplasmic kinase that interacts with scaffolding proteins involved in cell growth, adhesion, and polarization, and the role of Csk in regulating cellular apoptosis has gradually attracted attention. This study evaluates the role of Csk in Ang II-induced podocyte apoptosis. In vivo, Wistar rats were randomly subjected to a normal saline or Ang II infusion. In vitro, we exposed differentiated mouse podocytes to Ang II. Ang II increased Csk expression and induced podocyte apoptosis, stimulated Csk translocation and binding to Caveolin-1, and stimulated decreased Fyn pY416, increased Fyn pY529, and nephrin dephosphorylation. Csk knockdown prevented Ang II-induced podocyte apoptosis, reduced Fyn kinase inactivation, and increased the interaction between nephrin and the activated form of Fyn, accompanied by a reduced interaction between Csk and Caveolin-1. These findings indicate that Ang II induces podocyte injury via a Csk-dependent pathway.

DNA methyltransferase inhibitor CDA-II inhibits myogenic differentiation

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

Chen, Zirong; Department of Molecular Genetics and Microbiology, Shands Cancer Center, University of Florida, Gainesville, FL 32610; Jin, Guorong

2012-06-08

Highlights: Black-Right-Pointing-Pointer CDA-II inhibits myogenic differentiation in a dose-dependent manner. Black-Right-Pointing-Pointer CDA-II repressed expression of muscle transcription factors and structural proteins. Black-Right-Pointing-Pointer CDA-II inhibited proliferation and migration of C2C12 myoblasts. -- Abstract: CDA-II (cell differentiation agent II), isolated from healthy human urine, is a DNA methyltransferase inhibitor. Previous studies indicated that CDA-II played important roles in the regulation of cell growth and certain differentiation processes. However, it has not been determined whether CDA-II affects skeletal myogenesis. In this study, we investigated effects of CDA-II treatment on skeletal muscle progenitor cell differentiation, migration and proliferation. We found that CDA-II blocked differentiationmore » of murine myoblasts C2C12 in a dose-dependent manner. CDA-II repressed expression of muscle transcription factors, such as Myogenin and Mef2c, and structural proteins, such as myosin heavy chain (Myh3), light chain (Mylpf) and MCK. Moreover, CDA-II inhibited C1C12 cell migration and proliferation. Thus, our data provide the first evidence that CDA-II inhibits growth and differentiation of muscle progenitor cells, suggesting that the use of CDA-II might affect skeletal muscle functions.« less

Statistics of equivalent width data and new oscillator strengths for Si II, Fe II, and Mn II. [in interstellar medium

NASA Technical Reports Server (NTRS)

Van Buren, Dave

1986-01-01

Equivalent width data from Copernicus and IUE appear to have an exponential, rather than a Gaussian distribution of errors. This is probably because there is one dominant source of error: the assignment of the background continuum shape. The maximum likelihood method of parameter estimation is presented for the case of exponential statistics, in enough generality for application to many problems. The method is applied to global fitting of Si II, Fe II, and Mn II oscillator strengths and interstellar gas parameters along many lines of sight. The new values agree in general with previous determinations but are usually much more tightly constrained. Finally, it is shown that care must be taken in deriving acceptable regions of parameter space because the probability contours are not generally ellipses whose axes are parallel to the coordinate axes.

SphK1 inhibitor II (SKI-II) inhibits acute myelogenous leukemia cell growth in vitro and in vivo

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

Yang, Li; Weng, Wei; Sun, Zhi-Xin

Previous studies have identified sphingosine kinase 1 (SphK1) as a potential drug target for treatment of acute myeloid leukemia (AML). In the current study, we investigated the potential anti-leukemic activity of a novel and specific SphK1 inhibitor, SKI-II. We demonstrated that SKI-II inhibited growth and survival of human AML cell lines (HL-60 and U937 cells). SKI-II was more efficient than two known SphK1 inhibitors SK1-I and FTY720 in inhibiting AML cells. Meanwhile, it induced dramatic apoptosis in above AML cells, and the cytotoxicity by SKI-II was almost reversed by the general caspase inhibitor z-VAD-fmk. SKI-II treatment inhibited SphK1 activation, andmore » concomitantly increased level of sphingosine-1-phosphate (S1P) precursor ceramide in AML cells. Conversely, exogenously-added S1P protected against SKI-II-induced cytotoxicity, while cell permeable short-chain ceramide (C6) aggravated SKI-II's lethality against AML cells. Notably, SKI-II induced potent apoptotic death in primary human AML cells, but was generally safe to the human peripheral blood mononuclear cells (PBMCs) isolated from healthy donors. In vivo, SKI-II administration suppressed growth of U937 leukemic xenograft tumors in severe combined immunodeficient (SCID) mice. These results suggest that SKI-II might be further investigated as a promising anti-AML agent. - Highlights: • SKI-II inhibits proliferation and survival of primary and transformed AML cells. • SKI-II induces apoptotic death of AML cells, but is safe to normal PBMCs. • SKI-II is more efficient than two known SphK1 inhibitors in inhibiting AML cells. • SKI-II inhibits SphK1 activity, while increasing ceramide production in AML cells. • SKI-II dose-dependently inhibits U937 xenograft growth in SCID mice.« less

Electrochemistry of mixed-metal bimetallic complexes containing the pentacyanoferrate(II) or pentaammineruthenium(II) metal center

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

Moore, K.J.; Lee, L.; Mabbott, G.A.

1983-03-30

The electrochemistry of a series of mixed-metal bimetallic complexes of the type B/sub 5/MLM'B'/sub 5/, where B/sub 5/M = (CNN)/sub 5/Fe/sup II/ or (NH/sub 3/)/sub 5/Ru/sup II/, L = pyrazine, 4,4'-bipyridine, or 4-cyanopyridine, M'B'/sub 5/ = Rh/sup III/(NH/sub 3/)/sub 5/ or Co/sup III/(CN)/sub 5/, is reported. The bimetallic complexes all have metal-to-ligand charge-transfer (MLCT) bands associated with the M-B unit (d/sub ..pi../M ..-->.. p/sub ..pi../*L). The effect of the remote metal center, M'B'/sub 5/, is to function as a Lewis acid, shifting the MLCT maximum to lower energy and shifting the M/sup III///sup II/ reduction potential more positive with respectmore » to free B/sub 5/ML. The remote metal influence is attenuated by longer bridging ligands and by reduced ..pi..-overlap. A comparison of the electrochemical data of the mixed-valence Fe(II)/Fe(III) and Ru(II)/Ru(III) complexes to the mixed-metal Fe(II)/Co(III) and Ru(II)/Rh(III) complexes has enabled a quantitative measure of the stabilization due to electron delocalization in the mixed-valence complexes. The results show that electron delocalization is greater for the ruthenium complexes than for the iron complexes, is a small contributor to the total stabilization of the mixed-valence state, and even in ruthenium drops off rapidly as the length of the bridge increases.« less

Zeolite-encapsulated Co(II), Mn(II), Cu(II) and Cr(III) salen complexes as catalysts for efficient selective oxidation of benzyl alcohol

NASA Astrophysics Data System (ADS)

Li, F. H.; Bi, H.; Huang, D. X.; Zhang, M.; Song, Y. B.

2018-01-01

Co(II), Mn(II), Cu(II) and Cr(III) salen type complexes were synthesized in situ in Y zeolite by the reaction of ion-exchanged metal ions with the flexible ligand molecules that had diffused into the cavities. Data of characterization indicates the formation of metal salen complexes in the pores without affecting the zeolite framework structure, the absence of any extraneous species and the geometry of encapsulated complexes. The catalytic activity results show that Cosalcyen Y exhibited higher catalytic activity in the water phase selective oxidation of benzyl alcohol, which could be attributed to their geometry and the steric environment of the metal actives sites.

Physicochemical impact studies of gamma rays on "aspirin" analgesics drug and its metal complexes in solid form: Synthesis, spectroscopic and biological assessment of Ca(II), Mg(II), Sr(II) and Ba(II) aspirinate complexes

NASA Astrophysics Data System (ADS)

Refat, Moamen S.; Sharshar, T.; Elsabawy, Khaled M.; Heiba, Zein K.

2013-09-01

Metal aspirinate complexes, M2(Asp)4, where M is Mg(II), Ca(II), Sr(II) or Ba(II) are formed by refluxed of aspirin (Asp) with divalent non-transition metal ions of group (II) and characterized by elemental analysis and spectroscopic measurements (infrared, electronic, 1H NMR, Raman, X-ray powder diffraction and scanning electron microscopy). Elemental analysis of the chelates suggests the stoichiometry is 1:2 (metal:ligand). Infrared spectra of the complexes agree with the coordination to the central metal atom through three donation sites of two oxygen atoms of bridge bidentate carboxylate group and oxygen atom of sbnd Cdbnd O of acetyl group. Infrared spectra coupled with the results of elemental analyzes suggested a distorted octahedral structure for the M(II) aspirinate complexes. Gamma irradiation was tested as a method for stabilization of aspirin as well as their complexes. The effect of gamma irradiation, with dose of 80 Gy, on the properties of aspirinate complexes was studied. The aspirinate chelates have been screened for their in vitro antibacterial activity against four bacteria, gram-positive (Bacillus subtilis and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two strains of fungus (Aspergillus flavus and Candida albicans). The metal chelates were shown to possess more antibacterial activity than the free aspirin chelate.

A novel Schiff-base as a Cu(II) ion fluorescent sensor in aqueous solution

NASA Astrophysics Data System (ADS)

Gündüz, Z. Yurtman; Gündüz, C.; Özpınar, C.; Urucu, O. Aydın

2015-02-01

A new fluorescent Cu(II) sensor (L) obtained from the Schiff base of 5,5‧-methylene-bis-salicylaldehyde with amidol (2,4-diaminophenol) was synthesized and characterized by FT-IR, MS, 1H NMR, 13C NMR techniques. In the presence of pH 6.5 (KHPO4-Na2HPO4) buffer solutions, copper reacted with L to form a stable 2:1 complex. Fluorescence spectroscopic study showed that Schiff base is highly sensitive towards Cu(II) over other metal ions (K+, Na+, Al3+, Ni2+, Co2+, Fe3+, Zn2+, Pb2+) in DMSO/H2O (30%, v/v). The sensor L was successfully applied to the determination of copper in standard reference material. The structural properties and molecular orbitals of the complex formed between L and Cu2+ ions were also investigated using quantum chemical computations.

Capturing Cd(ii) and Pb(ii) from contaminated water sources by electro-deposition on hydrotalcite-like compounds.

PubMed

González, M A; Trócoli, R; Pavlovic, I; Barriga, C; La Mantia, F

2016-01-21

Two different hydrotalcite-like compounds were prepared and used as substrates for the electrochemical removal of extremely toxic pollutant cations, such as Cd(ii) and Pb(ii), from aqueous solutions, and their subsequent recovery for further potential applications. By deposition on the hydrotalcite electrode, it was possible to remove 75% of Cd(ii) contained in a starting 5.2 mM solution of CdCl2, which was subsequently recovered and concentrated up to 14.3 mM in a single step. A removal of almost 100% was obtained in the case of Pb(ii). Its recovery was largely hindered by the formation of several inert phases, among which is some stable formation of hydroxycarbonate. Our results suggest that the removal of these contaminants by hydrotalcite-like compounds occurs by the combination of two parallel processes: electro-deposition and adsorption. It was possible to achieve a removal capacity for Cd(ii) and Pb(ii) equal to 763 mg ga.m.(-1) and 1039 mg ga.m.(-1), respectively. These removal capacities, accompanied by an excellent posterior eluent-free recovery of Cd(ii), suggest that this new method could be an environmentally friendly alternative to the conventional adsorption wastewater treatment.

Oxidation of Fe(II) in rainwater.

PubMed

Willey, J D; Whitehead, R F; Kieber, R J; Hardison, D R

2005-04-15

Photochemically produced Fe(II) is oxidized within hours under environmentally realistic conditions in rainwater. The diurnal variation between photochemical production and reoxidation of Fe(II) observed in our laboratory accurately mimics the behavior of ferrous iron observed in field studies where the highest concentrations of dissolved Fe(ll) occur in afternoon rain during the period of maximum sunlight intensity followed by gradually decreasing concentrations eventually returning to early morning pre-light values. The experimental work presented here, along with the results of kinetics studies done by others, suggests thatthe primary process responsible for the decline in photochemically produced Fe(II) concentrations is oxidation by hydrogen peroxide. This reaction is first order with respect to both the concentrations of Fe(II) and H2O2. The second-order rate constant determined for six different authentic rain samples varied over an order of magnitude and was always less than or equal to the rate constant determined for this reaction in simple acidic solutions. Oxidation of photochemically produced ferrous iron by other oxidants including molecular oxygen, ozone, hydroxyl radical, hydroperoxyl/superoxide radical, and hexavalent chromium were found to be insignificant under the conditions present in rainwater. This study shows that Fe(II) occurs as at least two different chemical species in rain; photochemically produced Fe(II) that is oxidized over time periods of hours, and a background Fe(II) that is protected against oxidation, perhaps by organic complexation, and is stable against oxidation for days. Because the rate of oxidation of photochemically produced Fe(II) does not increase with increasing rainwater pH, the speciation of this more labile form of Fe(II) is also not controlled by simple hydrolysis reactions.

Origin of diffuse C II 158 micron and Si II 35 micron emission in the Carina nebula

NASA Astrophysics Data System (ADS)

Mizutani, M.; Onaka, T.; Shibai, H.

2004-08-01

We present the results of mapping observations with ISO of [O I] 63 μm, 145 μm, [N II] 122 μm, [C II] 158 μm, [Si II] 35 μm, and H_2 9.66 μm line emissions for the Carina nebula, an active star-forming region in the Galactic plane. The observations were made for the central 40 arcmin × 20 arcmin area of the nebula, including the optically bright H II region and molecular cloud lying in front of the ionized gas. Around the center of the observed area is the interface between the H II region and the molecular cloud which creates a typical photodissociation region (PDR). The [C II] 158 μm emission shows a good correlation with the [O I] 63 μm emission and peaks around the H II-molecular region interface. The correlated component has the ratio of [C II] 158 μm to [O I] 63 μm of about 2.8. We estimate from the correlation that about 80% of [C II] emission comes from the PDR in the Carina nebula. The photoelectric heating efficiency estimated from the ratio of the ([C II] 158 μm + [O I] 63 μm) intensity to the total far-infrared intensity ranges from 0.06 to 1.2%. [O I] 145 μm is detected marginally at 10 positions. The average ratio of [O I] 145 μm to [O I] 63 μm of these positions is about 0.09 ± 0.01 and is larger than model predictions. The observed [C II] 158 μm to [O I] 63 μm ratio indicates a relatively low temperature ( <500 K) of the gas, while the large [O I] 145 μm to 63 μm ratio suggests a high temperature (˜ 1000 K). This discrepancy cannot be accounted for consistently by the latest PDR model with the efficient photoelectric heating via polycyclic aromatic hydrocarbons (PAHs) even if absorption of [O I] 63 μm by foreground cold gas is taken into account. We suggest that absorption of [C II] 158 μm together with [O I] 63 μm by overlapping PDRs, in which the heating via PAHs is suppressed due to the charge-up effect, may resolve the discrepancy. Quite strong [Si II] 35 μm emission has been detected over the observed area. It shows a

About APPLE II Operation

NASA Astrophysics Data System (ADS)

Schmidt, T.; Zimoch, D.

2007-01-01

The operation of an APPLE II based undulator beamline with all its polarization states (linear horizontal and vertical, circular and elliptical, and continous variation of the linear vector) requires an effective description allowing an automated calculation of gap and shift parameter as function of energy and operation mode. The extension of the linear polarization range from 0 to 180° requires 4 shiftable magnet arrrays, permitting use of the APU (adjustable phase undulator) concept. Studies for a pure fixed gap APPLE II for the SLS revealed surprising symmetries between circular and linear polarization modes allowing for simplified operation. A semi-analytical model covering all types of APPLE II and its implementation will be presented.

Type-II Dirac photons

NASA Astrophysics Data System (ADS)

Wang, Hai-Xiao; Chen, Yige; Hang, Zhi Hong; Kee, Hae-Young; Jiang, Jian-Hua

2017-09-01

The Dirac equation for relativistic electron waves is the parent model for Weyl and Majorana fermions as well as topological insulators. Simulation of Dirac physics in three-dimensional photonic crystals, though fundamentally important for topological phenomena at optical frequencies, encounters the challenge of synthesis of both Kramers double degeneracy and parity inversion. Here we show how type-II Dirac points—exotic Dirac relativistic waves yet to be discovered—are robustly realized through the nonsymmorphic screw symmetry. The emergent type-II Dirac points carry nontrivial topology and are the mother states of type-II Weyl points. The proposed all-dielectric architecture enables robust cavity states at photonic-crystal—air interfaces and anomalous refraction, with very low energy dissipation.

Synthesis, characterization and biological activity of Cu(II), Ni(II) and Zn(II) complexes of biopolymeric Schiff bases of salicylaldehydes and chitosan.

PubMed

de Araújo, Eliene Leandro; Barbosa, Hellen Franciane Gonçalves; Dockal, Edward Ralph; Cavalheiro, Éder Tadeu Gomes

2017-02-01

Schiff bases have been prepared from biopolymer chitosan and salicylaldehyde, 5-methoxysalicylaldehyde, and 5-nitrosalicylaldehyde. Ligands were synthesized in a 1:1.5mol ratio, and their Cu(II), Ni(II) and Zn(II) complexes in a 1:1mol ratio (ligand:metal). Ligands were characterized by 1 H NMR and FTIR, resulting in degrees of substitution from 43.7 to 78.7%. Complexes were characterized using FTIR, electronic spectra, XPRD. The compounds were confirmed by the presence of an imine bond stretching in the 1630-1640cm -1 and νMetal-N and νMetal-O at <600cm -1 . Electronic spectra revealed that both Cu(II) and Ni(II) complexes present a square plane geometry. The crystallinity values were investigated by X-ray powder diffraction. Thermal behavior of all compounds was evaluated by TGA/DTG and DTA curves with mass losses related to dehydration and decomposition, with characteristic events for ligand and complexes. Schiff base complexes presented lower thermal stability and crystallinity than the starting chitosan. Residues were the metallic oxides as confirmed by XPRD, whose amounts were used in the calculation of the percentage of complexed metal ions. Surface morphologies were analyzed with SEM-EDAX. Preliminary cytotoxicity tests were performed using MTT assay with HeLa cells. Despite the differences in solubility, the free bases presented relatively low toxicity. Copyright © 2016 Elsevier B.V. All rights reserved.

Nickel(II) biosorption by Rhodotorula glutinis.

PubMed

Suazo-Madrid, Alicia; Morales-Barrera, Liliana; Aranda-García, Erick; Cristiani-Urbina, Eliseo

2011-01-01

The present study reports the feasibility of using Rhodotorula glutinis biomass as an alternative low-cost biosorbent to remove Ni(II) ions from aqueous solutions. Acetone-pretreated R. glutinis cells showed higher Ni(II) biosorption capacity than untreated cells at pH values ranging from 3 to 7.5, with an optimum pH of 7.5. The effects of other relevant environmental parameters, such as initial Ni(II) concentration, shaking contact time and temperature, on Ni(II) biosorption onto acetone-pretreated R. glutinis were evaluated. Significant enhancement of Ni(II) biosorption capacity was observed by increasing initial metal concentration and temperature. Kinetic studies showed that the kinetic data were best described by a pseudo-second-order kinetic model. Among the two-, three-, and four-parameter isotherm models tested, the Fritz-Schluender model exhibited the best fit to experimental data. Thermodynamic parameters (activation energy, and changes in activation enthalpy, activation entropy, and free energy of activation) revealed that the biosorption of Ni(II) ions onto acetone-pretreated R. glutinis biomass is an endothermic and non-spontaneous process, involving chemical sorption with weak interactions between the biosorbent and Ni(II) ions. The high sorption capacity (44.45 mg g(-1) at 25°C, and 63.53 mg g(-1) at 70°C) exhibited by acetone-pretreated R. glutinis biomass places this biosorbent among the best adsorbents currently available for removal of Ni(II) ions from aqueous effluents.

Fe(II)/Cu(II) interaction on goethite stimulated by an iron-reducing bacteria Aeromonas Hydrophila HS01 under anaerobic conditions.

PubMed

Tao, Liang; Zhu, Zhen-Ke; Li, Fang-Bai; Wang, Shan-Li

2017-11-01

Copper is a trace element essential for living creatures, but copper content in soil should be controlled, as it is toxic. The physical-chemical-biological features of Cu in soil have a significant correlation with the Fe(II)/Cu(II) interaction in soil. Of significant interest to the current study is the effect of Fe(II)/Cu(II) interaction conducted on goethite under anaerobic conditions stimulated by HS01 (a dissimilatory iron reduction (DIR) microbial). The following four treatments were designed: HS01 with α-FeOOH and Cu(II) (T1), HS01 with α-FeOOH (T2), HS01 with Cu(II) (T3), and α-FeOOH with Cu(II) (T4). HS01 presents a negligible impact on copper species transformation (T3), whereas the presence of α-FeOOH significantly enhanced copper aging contributing to the DIR effect (T1). Moreover, the violent reaction between adsorbed Fe(II) and Cu(II) leads to the decreased concentration of the active Fe(II) species (T1), further inhibiting reactions between Fe(II) and iron (hydr)oxides and decelerating the phase transformation of iron (hydr)oxides (T1). From this study, the effects of the Fe(II)/Cu(II) interaction on goethite under anaerobic conditions by HS01 are presented in three aspects: (1) the accelerating effect of copper aging, (2) the reductive transformation of copper, and (3) the inhibition effect of the phase transformation of iron (hydr)oxides. Copyright © 2017 Elsevier Ltd. All rights reserved.

Locations and properties of angiotensin II-responsive neurones in the circumventricular region of the duck brain.

PubMed Central

Matsumura, K; Simon, E

1990-01-01

1. In brain slice preparations from the hypothalamus of domestic ducks, single-unit activity was recorded extracellularly to investigate location and properties of angiotensin II (AngII)-responsive neurones in various periventricular regions. 2. When exposing the slice to 10(-7) M-AngII in the perfusion medium, more than 65% of the neurones recorded in the subfornical organ (SFO) were activated (49 out of 75) and none inhibited. In the magnocellular (MC) region of the paraventricular nucleus (PVN) only four out of eighty-one neurones were influenced by AngII; one was inhibited and three were activated. In the anterior third ventricle region (A3V) two out of twenty-one neurones were activated by AngII. In the dorsal periventricular (PeV) region, one out of thirty-seven neurones was activated and one inhibited. The changes in firing rate of AngII-responsive neurones at comparable doses of AngII were generally large in the SFO and A3V but were small in neurones from the MC and PeV regions. 3. Analysis of AngII-responsive SFO neurones consistently revealed a dose-dependent stimulation with a threshold at 10(-9) M-AngII. The AngII antagonist 1Sar-8Ile-AngII (4 x 10(-7) to 10(-6) M) caused reversible, complete or partial suppression of responsiveness to 10(-7) M-AngII. Synaptic blockade with a medium low in Ca2+ and high in Mg2+ did not abolish AngII responsiveness in eight out of ten SFO neurones tested. 4. Angiotensin III affected neither AngII-responsive nor AngII-insensitive neurones. When eighteen AngII-responsive neurones were exposed to hypertonic stimulation (+20 to +30 mosmol/kg) by adding NaCl to the perfusion medium, only one neurone was stimulated and two were inhibited. 5. The results indicate that: (a) the SFO is a specific target for circulating AngII; (b) although neurones in the A3V responsive to AngII are rare, the pronounced excitation of those which were found suggest that neurones in this region might serve as targets for AngII acting from the brain

AIM-9X Block II Sidewinder (AIM-9X Blk II)

DTIC Science & Technology

2013-12-01

Selected Acquisition Report (SAR) RCS: DD- A &T(Q& A )823-442 AIM-9X Block II Sidewinder (AIM-9X Blk II) As of FY 2015 President’s...4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with... a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE DEC 2013 2. REPORT TYPE 3. DATES COVERED

Antigen-B Cell Receptor Complexes Associate with Intracellular major histocompatibility complex (MHC) Class II Molecules*

PubMed Central

Barroso, Margarida; Tucker, Heidi; Drake, Lisa; Nichol, Kathleen; Drake, James R.

2015-01-01

Antigen processing and MHC class II-restricted antigen presentation by antigen-presenting cells such as dendritic cells and B cells allows the activation of naïve CD4+ T cells and cognate interactions between B cells and effector CD4+ T cells, respectively. B cells are unique among class II-restricted antigen-presenting cells in that they have a clonally restricted antigen-specific receptor, the B cell receptor (BCR), which allows the cell to recognize and respond to trace amounts of foreign antigen present in a sea of self-antigens. Moreover, engagement of peptide-class II complexes formed via BCR-mediated processing of cognate antigen has been shown to result in a unique pattern of B cell activation. Using a combined biochemical and imaging/FRET approach, we establish that internalized antigen-BCR complexes associate with intracellular class II molecules. We demonstrate that the M1-paired MHC class II conformer, shown previously to be critical for CD4 T cell activation, is incorporated selectively into these complexes and loaded selectively with peptide derived from BCR-internalized cognate antigen. These results demonstrate that, in B cells, internalized antigen-BCR complexes associate with intracellular MHC class II molecules, potentially defining a site of class II peptide acquisition, and reveal a selective role for the M1-paired class II conformer in the presentation of cognate antigen. These findings provide key insights into the molecular mechanisms used by B cells to control the source of peptides charged onto class II molecules, allowing the immune system to mount an antibody response focused on BCR-reactive cognate antigen. PMID:26400081

Searching for “LiCr{sup II}PO{sub 4}”

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

Mosymow, E.; Glaum, R., E-mail: rglaum@uni-bonn.de; Kremer, R.K.

The two new phosphates LiCr{sup II}{sub 4}(PO{sub 4}){sub 3} and Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4} are discovered as equilibrium phases (ϑ=800 °C) in the quarternary system Li/Cr/P/O. Their crystal structures have been determined from single-crystal X-ray diffraction data (LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}: violet-blue, Pnma (no. 62), Z=4, a=6.175(1) Å, b=14.316(3) Å, c=10.277(2) Å, 100 parameters, R{sub 1}=0.028, wR{sub 2}=0.08, 2060 unique reflections with F{sub o}>4σ(F{sub o}); Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4}: greyish-green, P1{sup ¯} (no. 2), Z=1, a=4.9379(7) Å, b=7.917(2) Å, c=8.426(2) Å, α=109.98(2)°, β=90.71(1)°, γ=104.91(1)°, 131 parameters, R{sub 1}=0.022, wR{sub 2}=0.067, 1594 unique reflectionsmore » with F{sub o}>4σ(F{sub o})). Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4} adopts an hitherto unknown structure type. The crystal structure of LiCr{sup II}{sub 4}(PO{sub 4}){sub 3} is isotypic to that of NaCd{sup II}{sub 4}(PO{sub 4}){sub 3} and related to that of the mineral silicocarnotite Ca{sub 5}(PO{sub 4}){sub 2}(SiO{sub 4}). Significant disorder between Li{sup +} and Cr{sup 2+} is observed for both crystal structures. The oxidation states assigned to chromium in these two phosphates are in agreement with UV/vis/NIR absorption spectra and magnetic susceptibility data recorded for both compounds. Instead of “LiCr{sup II}PO{sub 4}” mixtures of LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}, Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4}, Cr{sub 2}O{sub 3}, and CrP are observed at equilibrium. Instead of “Li{sub 2}Cr{sup II}P{sub 2}O{sub 7}” four-phase mixtures consisting of Li{sub 9}Cr{sup III}{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2}, Li{sub 3}Cr{sup III}{sub 2}(PO{sub 4}){sub 3}, LiCrP{sub 2}O{sub 7}, and CrP were obtained. - Graphical abstract: Investigations on the equilibrium relations in the system Li/Cr/P/O revealed the two hitherto unknown phosphates

Stellar rotation periods determined from simultaneously measured Ca II H&K and Ca II IRT lines

NASA Astrophysics Data System (ADS)

Mittag, M.; Hempelmann, A.; Schmitt, J. H. M. M.; Fuhrmeister, B.; González-Pérez, J. N.; Schröder, K.-P.

2017-11-01

Aims: Previous studies have shown that, for late-type stars, activity indicators derived from the Ca II infrared-triplet (IRT) lines are correlated with the indicators derived from the Ca II H&K lines. Therefore, the Ca II IRT lines are in principle usable for activity studies, but they may be less sensitive when measuring the rotation period. Our goal is to determine whether the Ca II IRT lines are sufficiently sensitive to measure rotation periods and how any Ca II IRT derived rotation periods compare with periods derived from the "classical" Mount Wilson S-index. Methods: To analyse the Ca II IRT lines' sensitivity and to measure rotation periods, we define an activity index for each of the Ca II IRT lines similar to the Mount Wilson S-index and perform a period analysis for the lines separately and jointly. Results: For eleven late-type stars we can measure the rotation periods using the Ca II IRT indices similar to those found in the Mount Wilson S-index time series and find that a period derived from all four indices gives the most probable rotation period; we find good agreement for stars with already existing literature values. In a few cases the computed periodograms show a complicated structure with multiple peaks, meaning that formally different periods are derived in different indices. We show that in one case, this is due to data sampling effects and argue that denser cadence sampling is necessary to provide credible evidence for differential rotation. However, our TIGRE data for HD 101501 shows good evidence for the presence of differential rotation.

Microbial Iron(II) Oxidation in Littoral Freshwater Lake Sediment: The Potential for Competition between Phototrophic vs. Nitrate-Reducing Iron(II)-Oxidizers

PubMed Central

Melton, E. D.; Schmidt, C.; Kappler, A.

2012-01-01

The distribution of neutrophilic microbial iron oxidation is mainly determined by local gradients of oxygen, light, nitrate and ferrous iron. In the anoxic top part of littoral freshwater lake sediment, nitrate-reducing and phototrophic Fe(II)-oxidizers compete for the same e− donor; reduced iron. It is not yet understood how these microbes co-exist in the sediment and what role they play in the Fe cycle. We show that both metabolic types of anaerobic Fe(II)-oxidizing microorganisms are present in the same sediment layer directly beneath the oxic-anoxic sediment interface. The photoferrotrophic most probable number counted 3.4·105 cells·g−1 and the autotrophic and mixotrophic nitrate-reducing Fe(II)-oxidizers totaled 1.8·104 and 4.5·104 cells·g−1 dry weight sediment, respectively. To distinguish between the two microbial Fe(II) oxidation processes and assess their individual contribution to the sedimentary Fe cycle, littoral lake sediment was incubated in microcosm experiments. Nitrate-reducing Fe(II)-oxidizing bacteria exhibited a higher maximum Fe(II) oxidation rate per cell, in both pure cultures and microcosms, than photoferrotrophs. In microcosms, photoferrotrophs instantly started oxidizing Fe(II), whilst nitrate-reducing Fe(II)-oxidizers showed a significant lag-phase during which they probably use organics as e− donor before initiating Fe(II) oxidation. This suggests that they will be outcompeted by phototrophic Fe(II)-oxidizers during optimal light conditions; as phototrophs deplete Fe(II) before nitrate-reducing Fe(II)-oxidizers start Fe(II) oxidation. Thus, the co-existence of the two anaerobic Fe(II)-oxidizers may be possible due to a niche space separation in time by the day-night cycle, where nitrate-reducing Fe(II)-oxidizers oxidize Fe(II) during darkness and phototrophs play a dominant role in Fe(II) oxidation during daylight. Furthermore, metabolic flexibility of Fe(II)-oxidizing microbes may play a paramount role in the

What's New in GSAS-II

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

Toby, Brian H.; Von Dreele, Robert B.

The General Structure and Analysis Software II (GSAS-II) package is an all-new crystallographic analysis package written to replace and extend the capabilities of the universal and widely used GSAS and EXPGUI packages. GSAS-II was described in a 2013 article, but considerable work has been completed since then. This paper describes the advances, which include: rigid body fitting and structure solution modules; improved treatment for parametric refinements and equation of state fitting; and small-angle scattering data reduction and analysis. GSAS-II offers versatile and extensible modules for import and export of data and results. Capabilities are provided for users to select anymore » version of the code. Code documentation has reached 150 pages and 17 web-tutorials are offered. © 2014 International Centre for Diffraction Data.« less

Carbonate-mediated Fe(II) oxidation in the air-cathode fuel cell: a kinetic model in terms of Fe(II) speciation.

PubMed

Song, Wei; Zhai, Lin-Feng; Cui, Yu-Zhi; Sun, Min; Jiang, Yuan

2013-06-06

Due to the high redox activity of Fe(II) and its abundance in natural waters, the electro-oxidation of Fe(II) can be found in many air-cathode fuel cell systems, such as acid mine drainage fuel cells and sediment microbial fuel cells. To deeply understand these iron-related systems, it is essential to elucidate the kinetics and mechanisms involved in the electro-oxidation of Fe(II). This work aims to develop a kinetic model that adequately describes the electro-oxidation process of Fe(II) in air-cathode fuel cells. The speciation of Fe(II) is incorporated into the model, and contributions of individual Fe(II) species to the overall Fe(II) oxidation rate are quantitatively evaluated. The results show that the kinetic model can accurately predict the electro-oxidation rate of Fe(II) in air-cathode fuel cells. FeCO3, Fe(OH)2, and Fe(CO3)2(2-) are the most important species determining the electro-oxidation kinetics of Fe(II). The Fe(II) oxidation rate is primarily controlled by the oxidation of FeCO3 species at low pH, whereas at high pH Fe(OH)2 and Fe(CO3)2(2-) are the dominant species. Solution pH, carbonate concentration, and solution salinity are able to influence the electro-oxidation kinetics of Fe(II) through changing both distribution and kinetic activity of Fe(II) species.

Geochemistry of the alginite and amorphous organic matter from type II-S kerogens

USGS Publications Warehouse

Stankiewicz, B.A.; Kruge, M.A.; Mastalerz, Maria; Salmon, G.L.

1996-01-01

Maceral fractions of the Type II-S kerogens from the Monterey Formation (Miocene. California. U.S.A.) and Duwi Formation (Campanian/Maastrichtian, Egypt) were separated by density gradient centrifugation. The Monterey Fm. kerogen sample was comprised chiefly of light red-fluorescing amorphous organic matter (AOM), the flash pyrolyzate of which was characterized by a predominance of alkylbenzenes, alkylthiophenes and alkylpyrroles. In contrast, the pyrolyzates of its alginite concentrate showed a highly aliphatic character, typical of this maceral, with the series of n-alkenes and n-alkanes (C6- C26) predominating. The pyrolyzate of the dominant light brown-fluorescing AOM of the Duwi Fm. kerogen had a relatively high concentration of alkylbenzenes and alkylthiophenes, while its elginite concentrate showed a more aliphatic character upon pyrolysis. There was a marked enrichment of thiophenic sulfur in the light-colored AOM of both samples (and also pyrrolic nitrogen in the case of the Monterey) relative to the alginite. The results support a bacterially-mediated, degradative origin for Type II-S amorphous organic matter, with algal remains as the primary source of the kerogen.

Photosystem II

ScienceCinema

James Barber

2017-12-09

James Barber, Ernst Chain Professor of Biochemistry at Imperial College, London, gives a BSA Distinguished Lecture titled, "The Structure and Function of Photosystem II: The Water-Splitting Enzyme of Photosynthesis."

Pyrazolate-based copper(II) and nickel(II) [2 x 2] grid complexes: protonation-dependent self-assembly, structures and properties.

PubMed

Klingele, Julia; Prikhod'ko, Alexander I; Leibeling, Guido; Demeshko, Serhiy; Dechert, Sebastian; Meyer, Franc

2007-05-28

The pyrazole-based diamide ligand N,N'-bis(2-pyridylmethyl)pyrazole-3,5-dicarboxamide (H(3)L) has been structurally characterised and successfully employed in the preparation of [2 x 2] grid-type complexes. Thus, the reaction of H(3)L with Cu(ClO(4))2.6H(2)O or Ni(ClO(4))2.6H(2)O in the presence of added base (NaOH) affords the tetranuclear complexes [M(4)(HL(4))].8H(2)O (1: M = Cu, 2: M = Ni). Employment of a mixture of the two metal salts under otherwise identical reaction conditions leads to the formation of the mixed-metal species [Cu(x)Ni(4-x)(HL)(4)].8H(2)O (xII) ions. The single crystal X-ray data obtained for the mixed-metal complex 3 gave the best results assuming a statistical distribution of copper and nickel ions. X-Band EPR spectra of 1 and 2 indicate magnetically coupled copper(II) ions and low-spin nickel(II), respectively. EPR spectra of a powdered sample of a complex with the general formulation [Cu(x)Ni(4-x)(HL)4].8H(2)O with a large excess of Ni(2+) (95%) was shown to be characteristic for individual copper(II) ions in the tetranuclear grid system. Magnetic susceptibility data of 1 indicate weak antiferromagnetic spin coupling between the copper ions (J = -8.2 +/- 0.4 cm(-1)), which is explained by the particular spatial arrangement of the magnetic orbitals.

Synthesis, characterization and physicochemical studies of new chelating resin 1, 8-(3, 6-dithiaoctyl)-4-polyvinylbenzenesulphonate (dpvbs) and its metallopolymer Cu(II), Ni(II), Co(II) and Fe(III) complexes

NASA Astrophysics Data System (ADS)

Khalil, Tarek E.; Elbadawy, Hemmat A.; El-Dissouky, Ali

2018-02-01

A new chelating resin, 1,8-(3,6-dithiaoctyl)-4-polyvinylbenzenesulphonate (dpvbs) has been synthesized by coupling Amberlite XAD-16 with (2,2‧-ethylenedithio) diethanol using pyridine/CH2Cl2 mixture as a solvent. The chelating resin and its metallopolymer Cu(II), Ni(II), Co(II) and Fe(III) complexes have been synthesized and characterized by EDS, SEM, XPS, elemental analysis, spectral (IR, UV/Vis, EPR). The thermal analysis of the resin and its metallopolymer complexes indicated an endothermic spontaneous sorption mechanism with the liberation of water of hydration of the metal ions and that adsorbed by the free resin. At the solid liquid interface, the degrees of freedom increased during the sorption of the metal ions onto the resin. The surface area of polymer support and its metallopolymer complexes are estimated by (BJH) method. The batch equilibrium method was used for studying the metal sorption and selectivity at different pH values and different contact times at room temperature. ICP-AES was used to estimate the metal capacity of the resin for sorption of Cu(II), Ni(II), Co(II) and Fe(III) from aqueous solutions utilizing the batch equilibrium method. The sorption tendency of the metal ions by the resin was found to be: Cu(II) > Fe(III) > Co(II) > Ni(II). Adsorption kinetics was found to be fit the pseudo-second order model.

Ferroelectric properties of oxalate and phenanthroline based 1-D single chain molecular magnet [{FeII(Δ)FeII(Λ)}0.5{CrII(Δ)CrII(Λ)}0.5(ox)2(phen)2

NASA Astrophysics Data System (ADS)

Bhatt, Pramod; Mukadam, M. D.; Mandal, B. P.; Yusuf, S. M.

2018-04-01

The one-dimensional (1-D) single chain molecular magnet [{FeII(Δ)FeII(Λ)}0.5{CrII(Δ)CrII(Λ)}0.5(ox)2(phen)2] is hydrothermally synthesized using oxalate (ox) and phenanthroline (phen) ligands with transition metal ions (Fe and Cr). The compound is characterized using x-ray diffraction, dc magnetization measurements and P-E ferroelectric loop measurements. The diffraction analysis using Rietveld refinement confirms a single phase formation of the compound in monoclinic structure with space group of P21. The compound crystallizes in 1-D chain like structure containing two different crystallographic sites of metal ions (Δ- and Λ-), which are bridged by the ox ligand and Phen ligand. These two metals site are different in bond length and bond angles results lattice distortions. The lattice distortion induces ferroelectric behavior in the compound which is discussed in terms of lattice distortion induced dipole moments.

Reduction of Ag{sup I}, Au{sup III}, Cu{sup II}, and Hg{sup II} by Fe{sup II}/Fe{sup III} hydroxysulfate green rust.

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

O'Loughlin, E. J.; Kelly, S. D.; Kemner, K. M.

Green rusts are mixed Fe{sup II}/Fe{sup III} hydroxides that are found in many suboxic environments where they are believed to play a central role in the biogeochemical cycling of iron. X-ray absorption fine structure analysis of hydroxysulfate green rust suspensions spiked with aqueous solutions of AgCH{sub 3}COO, AuCl{sub n}(OH){sub 4-n}, CuCl{sub 2}, or HgCl{sub 2} showed that Ag{sup I}, Au{sup III}, Cu{sup II}, and Hg{sup II} were readily reduced to Ag{sup 0}, Au{sup 0}, Cu{sup 0}, and Hg{sup 0}. Imaging of the resulting solids from the Ag{sup I}-, Au{sup III}-, and Cu{sup II}-amended green rust suspensions by transmission electron microscopymore » indicated the formation of submicron-sized particles of Ag{sup 0}, Au{sup 0}, and Cu{sup 0}. The facile reduction of Ag{sup I}, Au{sup III}, Cu{sup II}, and Hg{sup II} to Ag{sup 0}, Au{sup 0}, Cu{sup 0}, and Hg{sup 0}, respectively, by green rust suggests that the presence of green rusts in suboxic soils and sediments can have a significant impact on the biogeochemistry of silver, gold, copper, and mercury, particularly with respect to their mobility.« less

Small Business Innovation Research GRC Phase I, Phase II, and Post-Phase II Opportunity Assessment for 2015

NASA Technical Reports Server (NTRS)

Nguyen, Hung D.; Steele, Gynelle C.

2016-01-01

This report outlines the 2015 Small Business Innovation Research/Small Business Technology Transfer (SBIR/STTR) Phase I, Phase II, and Post-Phase II opportunity contract award results associated with NASA's Aeronautics Research Mission Directorate (ARMD), Human Exploration and Operations Mission Directorate (HEOMD), Science Mission Directorate (SMD), and Space Technology Mission Directorate (STMD) for NASA Glenn Research Center. The report also highlights the number of Phase I, Phase II, and Post-Phase II contracts awarded by mission directorate. The 2015 Phase I contract awards to companies in Ohio and their corresponding technologies are also discussed.

High removal efficacy of Hg(II) and MeHg(II) ions from aqueous solution by organoalkoxysilane-grafted lignocellulosic waste biomass.

PubMed

Saman, Norasikin; Johari, Khairiraihanna; Song, Shiow-Tien; Kong, Helen; Cheu, Siew-Chin; Mat, Hanapi

2017-03-01

An effective organoalkoxysilanes-grafted lignocellulosic waste biomass (OS-LWB) adsorbent aiming for high removal towards inorganic and organic mercury (Hg(II) and MeHg(II)) ions was prepared. Organoalkoxysilanes (OS) namely mercaptoproyltriethoxylsilane (MPTES), aminopropyltriethoxylsilane (APTES), aminoethylaminopropyltriethoxylsilane (AEPTES), bis(triethoxysilylpropyl) tetrasulfide (BTESPT), methacrylopropyltrimethoxylsilane (MPS) and ureidopropyltriethoxylsilane (URS) were grafted onto the LWB using the same conditions. The MPTES grafted lignocellulosic waste biomass (MPTES-LWB) showed the highest adsorption capacity towards both mercury ions. The adsorption behavior of inorganic and organic mercury ions (Hg(II) and MeHg(II)) in batch adsorption studies shows that it was independent with pH of the solutions and dependent on initial concentration, temperature and contact time. The maximum adsorption capacity of Hg(II) was greater than MeHg(II) which respectively followed the Temkin and Langmuir models. The kinetic data analysis showed that the adsorptions of Hg(II) and MeHg(II) onto MPTES-LWB were respectively controlled by the physical process of film diffusion and the chemical process of physisorption interactions. The overall mechanism of Hg(II) and MeHg(II) adsorption was a combination of diffusion and chemical interaction mechanisms. Regeneration results were very encouraging especially for the Hg(II); this therefore further demonstrated the potential application of organosilane-grafted lignocellulosic waste biomass as low-cost adsorbents for mercury removal process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Intracrine action of angiotensin II in mesangial cells: subcellular distribution of angiotensin II receptor subtypes AT1 and AT2.

PubMed

da Silva Novaes, Antônio; Ribeiro, Rosemara Silva; Pereira, Luciana Guilhermino; Borges, Fernanda Teixeira; Boim, Mirian Aparecida

2018-02-17

Biological effects of angiotensin II (AngII) such as regulation of AngII target genes may be triggered by interaction of AngII with intracellular AngII receptor types 1 and 2 (AT 1 and AT 2 ), defined as intracrine response. The aim of this study was to examine the presence of AT 1 and AT 2 receptors in nuclear membrane of human mesangial cells (HMCs) and evaluate the possible biological effects mediated by intracellular AT 1 through an intracrine mechanism. Subcellular distribution of AT 1 and AT 2 was evaluated by immunofluorescence and by western blot in isolated nuclear extract. Endogenous intracellular synthesis of AngII was stimulated by high glucose (HG). Effects of HG were analyzed in the presence of candesartan, which prevents AngII internalization. Both receptors were found in nuclear membrane. Fluorescein isothiocyanate (FITC)-labeled AngII added to isolated nuclei produced a fluorescence that was reduced in the presence of losartan or PD-123319 and quenched in the presence of both inhibitors simultaneously. HG induced overexpression of fibronectin and increased cell proliferation in the presence of candesartan, indicating an intracrine action of AngII induced by HG. Results showed the presence of nuclear receptors in HMCs that can be activated by AngII through an intracrine response independent of cytoplasmic membrane AngII receptors.

Bacterial group II introns: not just splicing.

PubMed

Toro, Nicolás; Jiménez-Zurdo, José Ignacio; García-Rodríguez, Fernando Manuel

2007-04-01

Group II introns are both catalytic RNAs (ribozymes) and mobile retroelements that were discovered almost 14 years ago. It has been suggested that eukaryotic mRNA introns might have originated from the group II introns present in the alphaproteobacterial progenitor of the mitochondria. Bacterial group II introns are of considerable interest not only because of their evolutionary significance, but also because they could potentially be used as tools for genetic manipulation in biotechnology and for gene therapy. This review summarizes what is known about the splicing mechanisms and mobility of bacterial group II introns, and describes the recent development of group II intron-based gene-targetting methods. Bacterial group II intron diversity, evolutionary relationships, and behaviour in bacteria are also discussed.

Chronic Metabolic Acidosis Activates Renal Tubular Sodium Chloride Cotransporter through Angiotension II-dependent WNK4-SPAK Phosphorylation Pathway

PubMed Central

Fang, Yu-Wei; Yang, Sung-Sen; Cheng, Chih-Jen; Tseng, Min-Hua; Hsu, Hui-Min; Lin, Shih-Hua

2016-01-01

The mechanism by which chronic metabolic acidosis (CMA) regulates sodium (Na+)-chloride (Cl−) cotransporter (NCC) in the renal distal convoluted tubules remains unexplored. We examined the role of STE20/SPS1-related proline/alanine-rich kinase (SPAK) and with-no-lysine kinase 4 (WNK4) on expression of NCC in mouse models of CMA. CMA was induced by NH4Cl in wild type mice (WTA mice), SPAK, and WNK4 knockout mice. The quantities of Ncc mRNA, expression of total NCC, phosphorylated (p)-NCC, SPAK and WNK4 in the kidneys as well as NCC inhibition with hydrochlorothiazide and Na+ balance were evaluated. Relative to WT mice, WTA mice had similar levels of Ncc mRNA, but increased expression of total and p-NCC, SPAK, and WNK4 and an exaggerated response to hydrochlorothiazide which could not be observed in SPAK or WNK4 knockout mice with CMA. In WTA mice, increased plasma renin activity, aldosterone and angiotensin II concentrations accompanied by a significantly negative Na+ balance. High Na+ diet abolished the enhanced NCC expression in WTA mice. Furthermore, an angiotensin II type 1 receptor blocker rather than a mineralocorticoid receptor antagonist exerted a marked inhibition on Na+ reabsorption and NCC phosphorylation in WTA mice. CMA increases WNK4-SPAK-dependent NCC phosphorylation and appears to be secondary to previous natriuresis with volume-dependent angiotensin II activation. PMID:26728390

Murine lymphoma L5178Y cells resistant to purine antagonists: differences in cross-resistance to thioguanine-platinum(II) and selenoguanine-platinum(II).

PubMed

Kanzawa, F; Maeda, M; Sasaki, T; Hoshi, A; Kuretani, K

1982-02-01

To determine whether the antitumor activities of thioguanine-platinum(II) [TG-Pt(II)] and selenoguanine-platinum(II) [SeG-Pt(II)] are due to direct actions of these compounds or to the actions of their hydrolysis products, studies were made on a purine antagonist-resistant, murine lymphoma L5178Y/MP subline that lacked the anabolic enzyme hypoxanthine-guanine phosphoribosyltransferase necessary for tumor inhibition. The L5178Y/MP subline proved to be highly resistant to both TG-Pt(II) and thioguanine; the resistance ratios to the two compounds were almost identical. The subline showed high resistance to selenoguanine, but the cross-resistance to SeG-Pt(II) was negligible. Whether the compounds exhibit the delayed cytotoxicity characteristic of purine antagonists was also investigated. Delayed cytotoxicity was demonstrated for TG-Pt(II) as well as for thioguanine and other purine antagonists but not for SeG-Pt(II) or cis-dichlorodiammineplatinum(II). Experiments on cross-resistance and delayed cytotoxicity showed differences in the cytotoxicities of TG-Pt(II) and SeG-Pt(II): TG-Pt(II) exerted its activity through its hydrolysis product thioguanine, whereas SeG-Pt(II) compound was cytotoxic itself.

Determination of kinetic and equilibrium parameters of the batch adsorption of Mn(II), Co(II), Ni(II) and Cu(II) from aqueous solution by black carrot (Daucus carota L.) residues.

PubMed

Güzel, Fuat; Yakut, Hakan; Topal, Giray

2008-05-30

In this study, the effect of temperature on the adsorption of Mn(II), Ni(II), Co(II) and Cu(II) from aqueous solution by modified carrot residues (MCR) was investigated. The equilibrium contact times of adsorption process for each heavy metals-MCR systems were determined. Kinetic data obtained for each heavy metal by MCR at different temperatures were applied to the Lagergren equation, and adsorption rate constants (kads) at these temperatures were determined. These rate constants related to the adsorption of heavy metal by MCR were applied to the Arrhenius equation, and activation energies (Ea) were determined. In addition, the isotherms for adsorption of each heavy metal by MCR at different temperatures were also determined. These isothermal data were applied to linear forms of isotherm equations that they fit the Langmuir adsorption isotherm, and the Langmuir constants (qm and b) were calculated. b constants determined at different temperatures were applied to thermodynamic equations, and thermodynamic parameters such as enthalpy (Delta H), free energy (Delta G), and entropy (Delta S) were calculated and these values show that adsorption of heavy metal on MCR was an endothermic process and process of adsorption was favoured at high temperatures.

High-sensitivity determination of Zn(II) and Cu(II) in vitro by fluorescence polarization

NASA Astrophysics Data System (ADS)

Thompson, Richard B.; Maliwal, Badri P.; Feliccia, Vincent; Fierke, Carol A.

1998-04-01

Recent work has suggested that free Cu(II) may play a role in syndromes such as Crohn's and Wilson's diseases, as well as being a pollutant toxic at low levels to shellfish and sheep. Similarly, Zn(II) has been implicated in some neural damage in the brain resulting from epilepsy and ischemia. Several high sensitivity methods exist for determining these ions in solution, including GFAAS, ICP-MS, ICP-ES, and electrochemical techniques. However, these techniques are generally slow and costly, require pretreatment of the sample, require complex instruments and skilled personnel, and are incapable of imaging at the cellular and subcellular level. To address these shortcomings we developed fluorescence polarization (anisotropy) biosensing methods for these ions which are very sensitivity, highly selective, require simple instrumentation and little pretreatment, and are inexpensive. Thus free Cu(II) or Zn(II) can be determined at picomolar levels by changes in fluorescence polarization, lifetime, or wavelength ratio using these methods; these techniques may be adapted to microscopy.

Advanced Residual Strength Degradation Rate Modeling for Advanced Composite Structures. Volume II. Tasks II and III.

DTIC Science & Technology

1981-07-01

ADVANCED COMPOSITE STRUCTURES VOLUME II - TASKS Ix AND III K. N. Lauraitis Tl J. T. Ryder ?l4 D. E. Pettit ~ Lockheed-California Company S Burbank...Strength Degradation Rate Final Report Modeling for Advanced Composite Structures 1 July 1979 to 29 May 1981 Vol II - Task II and III S. PERFORMIN ONG...identify by block namber) composites , graphite/epoxy, impact damage, damaged holes, fatigue, damage propagation, residual strength, NDI 20. ABSTRACT

Analysis of Antarctic Denitrification in 2003 Winter Observed by ILAS-II Onboard the ADEOS-II Satellite

NASA Astrophysics Data System (ADS)

Nakajima, H.; Saeki, K.; Sugita, T.

2005-12-01

Polar Stratospheric Clouds (PSC) play an important role in ozone destruction in both Arctic and Antarctic stratosphere in winter. They take up gas-phase nitric acid (HNO3) and grow up when temperature is below nitric acid saturation temperature (TNAT). When PSC becomes large, it starts to descend and nitric acid is removed from the air mass, resulting in denitrification. The Improved Limb Atmospheric Spectrometer-II (ILAS-II) onboard the Advanced Earth Observing Satellite-II (ADEOS-II) successfully made measurements for the whole Antarctic winter in 2003. ILAS-II measured vertical profiles of O3, HNO3, NO2, H2O, N2O, CH4, ClONO2, N2O5, etc. in addition to the aerosol extinction coefficients at 780 nm. In this study, we analyzed denitrification from ILAS-II HNO3 and N2O data in regard to temperature history on the trajectory. The quantity of denitrification was estimated from the difference between measured HNO3 and HNO3* assumed from HNO3-- N2O correlation. In this analysis, it was found that denitrification was observed only for those airmass that experienced temperature below TICE (ice saturation temperature) in late June, 2003. In late July, it was found that most airmass inside the polar vortex was denitrified regardless of temperature history. This suggests that permanent denitrification has occurred in June-July period. The transition of relationship between denitrification and airmass temperature history was discovered from the ILAS-II data. Also, major types of PSC have found to be changed from nitric acid trihydrate (NAT) in June to ice in July, from the ILAS-II data. This is considered to be due to the lack of nitric acid in the airmass due to the denitrification in July.

Improved selectivity for Pb(II) by sulfur, selenium and tellurium analogues of 1,8-anthraquinone-18-crown-5: synthesis, spectroscopy, X-ray crystallography and computational studies.

PubMed

Mariappan, Kadarkaraisamy; Alaparthi, Madhubabu; Hoffman, Mariah; Rama, Myriam Alcantar; Balasubramanian, Vinothini; John, Danielle M; Sykes, Andrew G

2015-07-14

We report here a series of heteroatom-substituted macrocycles containing an anthraquinone moiety as a fluorescent signaling unit and a cyclic polyheteroether chain as the receptor. Sulfur, selenium, and tellurium derivatives of 1,8-anthraquinone-18-crown-5 (1) were synthesized by reacting sodium sulfide (Na2S), sodium selenide (Na2Se) and sodium telluride (Na2Te) with 1,8-bis(2-bromoethylethyleneoxy)anthracene-9,10-dione in a 1 : 1 ratio. The optical properties of the new compounds are examined and the sulfur and selenium analogues produce an intense green emission enhancement upon association with Pb(II) in acetonitrile. Selectivity for Pb(II) is markedly improved as compared to the oxygen analogue 1 which was also competitive for Ca(II) ion. UV-Visible and luminescence titrations reveal that 2 and 3 form 1 : 1 complexes with Pb(II), confirmed by single-crystal X-ray studies where Pb(II) is complexed within the macrocycle through coordinate covalent bonds to neighboring carbonyl, ether and heteroether donor atoms. Cyclic voltammetry of 2-8 showed classical, irreversible oxidation potentials for sulfur, selenium and tellurium heteroethers in addition to two one-electron reductions for the anthraquinone carbonyl groups. DFT calculations were also conducted on 1, 2, 3, 6, 6 + Pb(II) and 6 + Mg(II) to determine the trend in energies of the HOMO and the LUMO levels along the series.

Predictive value of the APACHE II, SAPS II, SOFA and GCS scoring systems in patients with severe purulent bacterial meningitis.

PubMed

Pietraszek-Grzywaczewska, Iwona; Bernas, Szymon; Łojko, Piotr; Piechota, Anna; Piechota, Mariusz

2016-01-01

Scoring systems in critical care patients are essential for predicting of the patient outcome and evaluating the therapy. In this study, we determined the value of the Acute Physiology and Chronic Health Evaluation II (APACHE II), Simplified Acute Physiology Score II (SAPS II), Sequential Organ Failure Assessment (SOFA) and Glasgow Coma Scale (GCS) scoring systems in the prediction of mortality in adult patients admitted to the intensive care unit (ICU) with severe purulent bacterial meningitis. We retrospectively analysed data from 98 adult patients with severe purulent bacterial meningitis who were admitted to the single ICU between March 2006 and September 2015. Univariate logistic regression identified the following risk factors of death in patients with severe purulent bacterial meningitis: APACHE II, SAPS II, SOFA, and GCS scores, and the lengths of ICU stay and hospital stay. The independent risk factors of patient death in multivariate analysis were the SAPS II score, the length of ICU stay and the length of hospital stay. In the prediction of mortality according to the area under the curve, the SAPS II score had the highest accuracy followed by the APACHE II, GCS and SOFA scores. For the prediction of mortality in a patient with severe purulent bacterial meningitis, SAPS II had the highest accuracy.

Selective removal of cesium from aqueous solutions with nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell.

PubMed

Ding, Dahu; Lei, Zhongfang; Yang, Yingnan; Feng, Chuanping; Zhang, Zhenya

2014-04-15

A novel nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell (Ni(II)HCF(III)-WS) was developed to selectively remove cesium ion (Cs(+)) from aqueous solutions. This paper showed the first integral study on Cs(+) removal behavior and waste reduction analysis by using biomass adsorption material. The results indicated that the removal process was rapid and reached saturation within 2h. As a special characteristic of Ni(II)HCF(III)-WS, acidic condition was preferred for Cs(+) removal, which was useful for extending the application scope of the prepared biomass material in treating acidic radioactive liquid waste. The newly developed Ni(II)HCF(III)-WS could selectively remove Cs(+) though the coexisting ions (Na(+) and K(+) in this study) exhibited negative effects. In addition, approximately 99.8% (in volume) of the liquid waste was reduced by using Ni(II)HCF(III)-WS and furthermore 91.9% (in volume) of the spent biomass material (Cs-Ni(II)HCF(III)-WS) was reduced after incineration (at 500°C for 2h). Due to its relatively high distribution coefficient and significant volume reduction, Ni(II)HCF(III)-WS is expected to be a promising material for Cs(+) removal in practice. Copyright © 2014 Elsevier B.V. All rights reserved.

30 CFR 57.22235 - Actions at 1.0 percent methane (I-C, II-A, II-B, and IV mines).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Actions at 1.0 percent methane (I-C, II-A, II-B, and IV mines). 57.22235 Section 57.22235 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Actions at 1.0 percent methane (I-C, II-A, II-B, and IV mines). (a) If methane reaches 1.0 percent in the...

30 CFR 57.22235 - Actions at 1.0 percent methane (I-C, II-A, II-B, and IV mines).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Actions at 1.0 percent methane (I-C, II-A, II-B... AND NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22235 Actions at 1.0 percent methane (I-C, II-A, II-B, and IV mines). (a) If methane reaches 1.0 percent in the...

Possible steric control of the relative strength of chelation enhanced fluorescence for zinc(II) compared to cadmium(II): metal ion complexing properties of tris(2-quinolylmethyl)amine, a crystallographic, UV-visible, and fluorometric study.

PubMed

Williams, Neil J; Gan, Wei; Reibenspies, Joseph H; Hancock, Robert D

2009-02-16

-stacking between quinolyl groups from adjacent TQA molecules. Formation constants determined by UV-visible spectroscopy are reported in 0.1 M NaClO(4) at 25 degrees C for TQA with Zn(II), Cd(II), and Pb(II). When compared with other similar ligands, one sees that, as the level of steric crowding increases, the stability decreases most with the small Zn(II) ion and least with the large Pb(II) ion. This is in accordance with the idea that TQA has a moderate level of steric crowding and that steric crowding increases for TQA analogs tris(2-pyridylmethyl)amine (TPyA) < TQA < tris(6-methyl-2-pyridyl)amine (TMPyA).

Hydrogen sulfide facilities production of nitric oxide via the Akt/endothelial nitric oxide synthases signaling pathway to protect human umbilical vein endothelial cells from injury by angiotensin II.

PubMed

Cui, Jiasen; Zhuang, Shunjiu; Qi, Shaohong; Li, Li; Zhou, Junwen; Zhang, Wan; Zhao, Yun; Qi, Ning; Yin, Yangjun; Huang, Lu

2017-11-01

Angiotensin II (Ang II) has been reported as key in inducing endothelial cell injury, and endothelial cells may produce nitric oxide (NO) to protect themselves. However, the underlying mechanism remains elusive. Human umbilical vein endothelial cells (HUVECs) were divided into five treatment groups as follows: Normal control, Ang II, Ang II + sodium hydrosulfide [NaHS; hydrogen sulfide (H2S) donor], Ang II + Akt inhibitors + NaHS, and Ang II + endothelial nitric oxide synthases (eNOS) inhibitors + NaHS. Subsequently, cell viability, apoptosis, migration, proliferation and adhesion ability were determined. In addition, tubular structure formation was observed, and the NO and phosphorylation levels of Akt and eNOS were evaluated. Compared with the normal control group, Ang II treatment reduced the viability of HUVECs and increased the level of cell apoptosis (P<0.05). Furthermore, Ang II treatment inhibited the phosphorylation level of eNOS and Akt, as well as the generation of NO (P<0.05). H2S reversed the above‑mentioned effects significantly and increased cell proliferation, adhesion ability and promoted tubular structure formation (P<0.05); however, H2S did not reverse the impact of eNOS and Akt phosphorylation levels after being processed with Akt and eNOS inhibitors, which indicates that H2S is capable of protecting HUVECs via the eNOS/Akt signaling pathway (P<0.05). Thus, H2S stimulates the production of NO and protects HUVECs via inducing the Akt/eNOS signaling pathway.

Phthalocyaninatoruthenium(II), Hexakis(dimethylsulfoxide)Phthalocyaninatoruthenium(II), and Hexadis(dimethylsulfoxide-d6)phthalocyanin-atoruthenium(II), Three Highly Selective NMR Shift Reagents.

DTIC Science & Technology

1977-07-18

dimethylsu lfoxi de-d6) phthalocyanin — atoruthenium (II), Three Highly Selective NMR Shift Reagents ( ~‘ iby j \\ / Clement K. Choy and F•lalcolm E. Kenney...Running head : Phthalocyaninatorut henium( II) Shift Reagents I NTRODUCT ION Previously, work on FePc (Pc = phthalocyanine li gand , C32H16N8) show- ing...RuPc and dimethylsulfoxide -d 6 were re cted together and the product isolated, An nmr spectrum of the product showed only phthalocyanine resorar.ces

Cd (II) and holodirected lead (II) 3D-supramolecular coordination polymers based on nicotinic acid: Structure, fluorescence property and photocatalytic activity

NASA Astrophysics Data System (ADS)

Etaiw, Safaa El-din H.; Abd El-Aziz, Dina M.; Marie, Hassan; Ali, Elham

2018-05-01

Two new supramolecular coordination polymers namely {[Cd(NA)2(H2O)]}, SCP 1 and {[Pb(NA)2]}, SCP 2, (NA = nicotinate ligand) were synthesized by self-assembly method and structurally characterized by different analytical and spectroscopic methods. Single-crystal X-ray diffraction showed that SCP 1 extend in three dimensions containing bore structure where the 3D- network is constructed via interweaving zigzag chains. The Cd atom coordinates to (O4N2) atoms forming distorted-octahedral configuration. The structure of SCP 2 extend down the projection of the b-axis creating parallel zigzag 1D-chains connected by μ2-O2 atoms and H-bonds forming a holodirected lead (II) hexagonal bi-pyramid configuration. SCP 2 extend to 3D-network via coordinate and hydrogen bonds. The thermal stability, photoluminescence properties, photocatalytic activity for the degradation of methylene blue dye (MB) under UV-irradiation and sunlight irradiation were also studied.

Interaction with biomacromolecules and antiproliferative activities of Mn(II), Ni(II), Zn(II) complexes of demethylcantharate and 2,2'-bipyridine

NASA Astrophysics Data System (ADS)

Zhang, Fan; Lin, Qiu-Yue; Hu, Wan-Li; Song, Wen-Ji; Shen, Shu-Ting; Gui, Pan

2013-06-01

Three new transition metal complexes [Mn2(DCA)2(bipy)2]·5H2O (1), [M2(DCA)2(bipy)2(H2O)]·10H2O(M = Ni(II)(2);Zn(II)(3)), (DCA = demethylcantharate, 7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylate, C8H8O5) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra and X-ray diffraction techniques. Each metal ion was six-coordinated in complexes. Complex 1 has a Mn2O2 center. Complexes 2 and 3 have asymmetric binuclear structure. Great amount of intermolecular hydrogen-bonding and π-π* stacking interactions were formed in these complex structures. The DNA-binding properties of complexes were investigated by electronic absorption spectra and viscosity measurements. The DNA binding constants Kb/(L mol-1) were 1.71 × 104 (1), 2.62 × 104 (2) and 1.59 × 104 (3) at 298 K. The complexes could quench the intrinsic fluorescence of bovine serum albumin (BSA) strongly through static quenching. The protein binding constants Ka/(L mol-1) were 7.27 × 104 (1), 4.55 × 104 (2) and 7.87 × 104 L mol-1 (3) and binding site was one. The complexes bind more tightly with DNA and BSA than with ligands. Complexes 1 and 3 had stronger inhibition ratios than Na2(DCA) against human hepatoma cells (SMMC-7721) lines and human gastric cancer cells (MGC80-3) lines in vitro. Complex 3 showed the strongest antiproliferative activity against SMMC-7721 (IC50 = 29.46 ± 2.12 μmol L-1) and MGC80-3 (IC50 = 27.02 ± 2.38 μmol L-1), which shows potential in anti-cancer drug development.

ASDIR-II. Volume II. Program Description

DTIC Science & Technology

1975-01-01

in ASDIR. INPUT: Engine description, gas properties and case definition (See ASDIR-II, Volume I, User’s Manual). OIWPUT: Primarily the information...conditions Special surface cooling flow conditions Exhaust system surface properties The predictions provided by the progi un for the combination of a...nonattenuated by the atmosphere Optional exhaust system information which can be requested from the program is: Internal fluid flow properties Surface

Impact of a commercial glyphosate formulation on adsorption of Cd(II) and Pb(II) ions on paddy soil.

PubMed

Divisekara, T; Navaratne, A N; Abeysekara, A S K

2018-05-01

Use of glyphosate as a weedicide on rice cultivation has been a controversial issue in Sri Lanka, due to the hypothesis that the metal complexes of commercial glyphosate is one of the causative factors of Chronic Kidney Disease of unknown aetiology (CKDu) prevalent in some parts of Sri Lanka. The effect of commercial glyphosate on the adsorption and desorption of Cd(II) and Pb(II) ions on selective paddy soil studied using batch experiments, over a wide concentration range, indicates that the Langmuir adsorption isotherm model is obeyed at low initial metal ion concentrations while the Freundlich adsorption isotherm model obeys at high metal ion concentrations in the presence and absence of glyphosate. For all cases, adsorption of both Cd(II) and Pb(II) ions obeys pseudo second order kinetics, suggesting that initial adsorption is a chemisorption process. In the presence of glyphosate formulation, the extent of adsorption of Cd(II) and Pb(II) ions on soil is decreased, while their desorption is increased at high concentrations of glyphosate. Low concentrations of glyphosate formulation do not significantly affect the desorption of metal ions from soil. Reduction of adsorption leads to enhance the concentration of Cd(II) and Pb(II) ions in the aqueous phase when in contact with soil. Copyright © 2018 Elsevier Ltd. All rights reserved.

On the Nature of Ultra-faint Dwarf Galaxy Candidates. II. The Case of Cetus II

NASA Astrophysics Data System (ADS)

Conn, Blair C.; Jerjen, Helmut; Kim, Dongwon; Schirmer, Mischa

2018-04-01

We obtained deep Gemini GMOS-S g, r photometry of the ultra-faint dwarf galaxy candidate Cetus II with the aim of providing stronger constraints on its size, luminosity, and stellar population. Cetus II is an important object in the size–luminosity plane, as it occupies the transition zone between dwarf galaxies and star clusters. All known objects smaller than Cetus II (r h ∼ 20 pc) are reported to be star clusters, while most larger objects are likely dwarf galaxies. We found a prominent excess of main-sequence stars in the color–magnitude diagram of Cetus II, best described by a single stellar population with an age of 11.2 Gyr, metallicity of [Fe/H] = ‑1.28 dex, an [α/Fe] = 0.0 dex at a heliocentric distance of 26.3 ± 1.2 kpc. As well as being spatially located within the Sagittarius dwarf tidal stream, these properties are well matched to the Sagittarius galaxy’s Population B stars. Interestingly, like our recent findings on the ultra-faint dwarf galaxy candidate Tucana V, the stellar field in the direction of Cetus II shows no evidence of a concentrated overdensity despite tracing the main sequence for over six magnitudes. These results strongly support the picture that Cetus II is not an ultra-faint stellar system in the Milky Way halo, but made up of stars from the Sagittarius tidal stream.

Chemical speciation and bioavailability of Cu(II). Study of the ionic copper(II) and bis(glycinate)-copper(II) accumulation by Lemna species

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

Benda, F.; Kouba, J.

1991-03-01

In this paper, the authors examined the accumulation of copper(II) in, and its toxic effect on, duckweed, a plant which exhibits extremely high concentration factors. The effect of copper(II) was investigated by adding it to the minimal medium in two forms: CuSO{sub 4} and (Cu(Gly){sub 2}). The neutral (2:1) tetracoordinated bis(glycinate)-copper(II) complex is constituted by two five-membered rings bonded to the central copper atom with the cis configuration. This complex was chosen to model the function of a neutral species (eliminating the charge effect) involving a nontoxic ligand, for which - in contrast to the hydrated Cu{sup 2+} species -more » direct permeation through the cell wall is conceivable.« less

Synthesis, spectral and theoretical studies of Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2'-hydroxynaphthaline.

PubMed

Gaber, Mohamed; El-Ghamry, Hoda; Atlam, Faten; Fathalla, Shaimaa

2015-02-25

Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2'-hydroxynaphthaline have been isolated and characterized by elemental analysis, IR, (1)H NMR, EI-mass, UV-vis, molar conductance, magnetic moment measurements and thermogravimetric analysis. The molar conductance values indicated that the complexes are non-electrolytes. The magnetic moment values of the complexes displayed diamagnetic behavior for Pd(II) and Pt(II) complexes and tetrahedral geometrical structure for Ni(II) complex. From the bioinorganic applications point of view, the interaction of the ligand and its metal complexes with CT-DNA was investigated using absorption and viscosity titration techniques. The Schiff-base ligand and its metal complexes have also been screened for their antimicrobial and antitumor activities. Also, theoretical investigation of molecular and electronic structures of the studied ligand and its metal complexes has been carried out. Molecular orbital calculations were performed using DFT (density functional theory) at B3LYP level with standard 6-31G(d,p) and LANL2DZ basis sets to access reliable results to the experimental values. The calculations were performed to obtain the optimized molecular geometry, charge density distribution, extent of distortion from regular geometry, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), Mulliken atomic charges, reactivity index (ΔE), dipole moment (D), global hardness (η), softness (σ), electrophilicity index (ω), chemical potential and Mulliken electronegativity (χ). Copyright © 2014 Elsevier B.V. All rights reserved.

Wavelengths, energy levels and hyperfine structure of Mn II and Sc II.

NASA Astrophysics Data System (ADS)

Nave, Gillian; Pickering, Juliet C.; Townley-Smith, Keeley I. M.; Hala, .

2015-08-01

For many decades, the Atomic Spectroscopy Groups at the National Institute of Standards and Technology (NIST) and Imperial College London (ICL) have measured atomic data of astronomical interest. Our spectrometers include Fourier transform (FT) spectrometers at NIST and ICL covering the region 1350 Å to 5.5 μm and a 10.7-m grating spectrometer at NIST covering wavelengths from 300 - 5000 Å. Sources for these spectra include high-current continuous and pulsed hollow cathode (HCL) lamps, Penning discharges, and sliding spark discharges. Recent work has focused on the measurement and analysis of wavelengths, energy levels, and hyperfine structure (HFS) constants for iron-group elements. The analysis of FT spectra of Cr I, Mn I, and Mn II is being led by ICL and is described in a companion poster [1]. Current work being led by NIST includes the analysis of HFS in Mn II, analysis of Mn II in the vacuum ultraviolet, and a comprehensive analysis of Sc II.Comprehensive HFS constants for Mn II are needed for the interpretation of stellar spectra and incorrect abundances may be obtained when HFS is omitted. Holt et al. [2] have measured HFS constants for 59 levels of Mn II using laser spectroscopy. We used FT spectra of Mn/Ni and Mn/Cu HCLs covering wavelength ranges from 1350 Å to 5.4 μm to confirm 26 of the A constants of Holt et al. and obtain values for roughly 40 additional levels. We aim to obtain HFS constants for the majority of lines showing significant HFS that are observed in chemically-peculiar stars.Spectra of Sc HCLs have been recorded from 1800 - 6700 Å using a vacuum ultraviolet FT spectrometer at NIST. Additional measurements to cover wavelengths above 6700 Å and below 1800 Å are in progress. The spectra are being analyzed by NIST and Alighar Muslim University, India in order to derive improved wavelengths, energy levels, and hyperfine structure parameters.This work was partially supported by NASA, the STFC and PPARC (UK), the Royal Society of the UK

National Synchrotron Light Source II

ScienceCinema

Steve Dierker

2017-12-09

The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

Multi-reverse flow injection analysis integrated with multi-optical sensor for simultaneous determination of Mn(II), Fe(II), Cu(II) and Fe(III) in natural waters.

PubMed

Youngvises, Napaporn; Suwannasaroj, Kittigan; Jakmunee, Jaroon; AlSuhaimi, Awadh

2017-05-01

Multi-reverse flow injection analysis (Mr-FIA) integrated with multi-optical sensor was developed and optimized for the simultaneous determination of multi ions; Mn(II), Fe(II), Cu(II) and Fe(III) in water samples. The sample/standard solutions were propelled making use of a four channels peristaltic pump whereas 4 colorimetric reagents specific for the metal ions were separately injected in sample streams using multi-syringe pump. The color zones that formed in the individual mixing coils were then streamed into multi-channels spectrometer, which comprised of four flows through cell and four pairs of light emitting diode and photodiode, whereby signals were measured concurrently. The linearity range (along with detection limit, µgL -1 ) was 0.050-3.0(16), 0.30-2.0 (11), 0.050-1.0(12) and 0.10-1.0(50)mgL -1 , for Mn(II), Fe(II), Cu(II) and Fe(III), respectively. In the interim, the correlation coefficients were 0.9924-0.9942. The percentages relative standard deviation was less than 3. The proposed system was applied successfully to determine targeted metal ions simultaneously in natural water with high sample throughput and low reagent consumption, thus it satisfies the criteria of Green Analytical Chemistry (GAC) and its goals. Copyright © 2016 Elsevier B.V. All rights reserved.

Kinetic and thermodynamic studies of the Co(II) and Ni(II) ions removal from aqueous solutions by Ca-Mg phosphates.

PubMed

Ivanets, A I; Srivastava, V; Kitikova, N V; Shashkova, I L; Sillanpää, M

2017-03-01

The aim of this work was to study the sorption kinetics and thermodynamics of Co(II) and Ni(II) from aqueous solutions by sorbents on the basis of hydrogen (PD-1) and tertiary (PD-2) Ca-Mg phosphates depending on the solution temperature and sorbents chemical composition. Kinetic studies of adsorption of Co(II) and Ni(II) ions onto samples of phosphate sorbents were performed in batch experiment at the temperatures 288, 303, 318 and 333 K. The sorbent dose was fixed at 10 g L -1 , initial pH value 2.6, and contact time varied from 5 to 600 min. The kinetics of Co(II) and Ni(II) adsorption were analyzed by using pseudo-first order, pseudo-second order and intraparticle diffusion models. Thermodynamic parameters (ΔG°, ΔH° and ΔS°) for the sorption of Co(II) and Ni(II) were determined using the Gibbs-Helmholtz equation. The calculated kinetic parameters and corresponding correlation coefficients revealed that Co(II) and Ni(II) uptake process followed the pseudo-second order rate expression. Thermodynamic studies confirmed the spontaneous and endothermic nature of removal process which indicate that sorption of Co(II) and Ni(II) ions onto both phosphate sorbents is favoured at higher temperatures and has the chemisorptive mechanism. The data thus obtained would be useful for practical application of the low cost and highly effective Ca-Mg phosphate sorbents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Na8Au9.8(4)Ga7.2 and Na17Au5.87(2)Ga46.63: The diversity of pseudo 5-fold symmetries in the Na-Au-Ga system

NASA Astrophysics Data System (ADS)

Smetana, Volodymyr; Corbett, John D.; Miller, Gordon J.

2013-11-01

The Na-rich part (~30% Na) of the Na-Au-Ga system between NaAu2, NaGa4, and Na22Ga39 has been found to contain the ternary phases Na8Au9.8(4)Ga7.2 (I) and Na17Au5.87(2)Ga46.63 (II), according to the results of single crystal X-ray diffraction measurements. I is orthorhombic, Cmcm, a=5.3040(1), b=24.519(5), c=14.573(3) Å, and contains a network of clusters with local 5-fold symmetry along the a-axis. Such clusters are frequent building units in decagonal quasicrystals and their approximants. II is rhombohedral, R3¯m, a=16.325(2), c=35.242(7) Å, and contains building blocks that are structurally identical to the Bergman-type clusters as well as fused icosahedral units known with active metals, triels and late transition elements. II also contains a polycationic network with elements of the clathrate V type structure. Tight-binding electronic structure calculations using linear muffin-tin-orbital (LMTO) methods on idealized models of I and II indicate that both compounds are metallic with evident pseudogaps at the corresponding Fermi levels. The overall Hamilton bond populations are generally dominated by Au-Ga and Au-Au bonds in I and by Ga-Ga bonds in II; moreover, the Na-Au and Na-Ga contributions in I are unexpectedly large, ~20% of the total. A similar involvement of sodium in covalent bonding has also been found in the electron-richer i-Na13Au12Ga15 quasicrystal approximant.

PARIS II: DESIGNING GREENER SOLVENTS

EPA Science Inventory

PARIS II (the program for assisting the replacement of industrial solvents, version II), developed at the USEPA, is a unique software tool that can be used for customizing the design of replacement solvents and for the formulation of new solvents. This program helps users avoid ...

Supramolecular complexes of Co(II), Ni(II) and Zn(II) p-hydroxybenzoates with caffeine: Synthesis, spectral characterization and crystal structure

NASA Astrophysics Data System (ADS)

Taşdemir, Erdal; Özbek, Füreya Elif; Sertçelik, Mustafa; Hökelek, Tuncer; Çelik, Raziye Çatak; Necefoğlu, Hacali

2016-09-01

Three novel complexes Co(II), Ni(II) and Zn(II) containing p-hydroxybenzoates and caffeine ligands were synthesized and characterized by elemental analysis, FT-IR and UV-vis Spectroscopy, molar conductivity and single crystal X-ray diffraction methods. The thermal properties of the synthesized complexes were investigated by TGA/DTA. The general formula of the complexes is [M(HOC6H4COO)2(H2O)4]·2(C8H10N4O2)·8H2O (where: M: Co, Ni and Zn). The IR studies showed that carboxylate groups of p-hydroxybenzoate ligands have monodentate coordination mode. The M2+ ions are octahedrally coordinated by two p-hydroxybenzoate ligands, four water molecules leading to an overall MO6 coordination environment. The medium-strength hydrogen bondings involving the uncoordinated caffeine ligands and water molecules, coordinated and uncoordinated water molecules and p-hydroxybenzoate ligands lead to three-dimensional supramolecular networks in the crystal structures.

The II Zw 40 Supernebula

NASA Astrophysics Data System (ADS)

Leitherer, C.; Byler, N.; Lee, J. C.; Levesque, E. M.

2017-11-01

We obtained HST COS G140L spectroscopy of the enigmatic nearby blue compact dwarf galaxy II Zw 40. The galaxy hosts a nuclear super star cluster with a luminosity 10 times that of 30 Doradus, the most powerful giant HII region in the Local Group. The super star cluster has been suggested to be the ionizing source of a ”supernebula” detected via its free-free radiation in the radio. The physical conditions, however, are much more complex, as demonstrated by the detection of the nebular He II and the mid-infrared line of [O IV] 25.9. These lines are unlikely to be related to hot stars and require a different powering source. II Zw 40 shares many similarities with the related blue compact dwarfs NGC 5253 and Henize 2-10. However, II Zw 40’s UV spectrum is unique in terms of the exceptional strength of He II 1640, O III 1663 and CIII 1909. We determined reddening, age, and the stellar initial mass function and perform a comparison with the local benchmark 30 Doradus. Photoionization modeling is used to determine the origin of the nebular lines as due to stellar ionization, shocks, or powering by a black hole.

Speciation of aqueous Ni(II)-carboxylate and Ni(II)-fulvic acid solutions: Combined ATR-FTIR and XAFS analysis

NASA Astrophysics Data System (ADS)

Strathmann, Timothy J.; Myneni, Satish C. B.

2004-09-01

Aqueous solutions containing Ni(II) and a series of structurally related carboxylic acids were analyzed using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and Ni K-edge X-ray absorption fine structure spectroscopy (XAFS). XAFS spectra were also collected for solutions containing Ni 2+ and chelating ligands (ethylenediaminetetraacetic acid, nitrilotriacetic acid (NTA)) as well as soil fulvic acid. Limited spectral changes are observed for aqueous Ni(II) complexes with monocarboxylates (formate, acetate) and long-chain polycarboxylates (succinate, tricarballylate), where individual donor groups are separated by multiple bridging methylene groups. These spectral changes indicate weak interactions between Ni(II) and carboxylates, and the trends are similar to some earlier reports for crystalline Ni(II)-acetate solids, for which X-ray crystallography studies have indicated monodentate Ni(II)-carboxylate coordination. Nonetheless, electrostatic or outer-sphere coordination cannot be ruled out for these complexes. However, spectral changes observed for short-chain dicarboxylates (oxalate, malonate) and carboxylates that contain an alcohol donor group adjacent to one of the carboxylate groups (lactate, malate, citrate) demonstrate inner-sphere metal coordination by multiple donor groups. XAFS spectral fits of Ni(II) solutions containing soil fulvic acid are consistent with inner-sphere Ni(II) coordination by one or more carboxylate groups, but spectra are noisy and outer-sphere modes of coordination cannot be ruled out. These molecular studies refine our understanding of the interactions between carboxylates and weakly complexing divalent transition metals, such as Ni(II).

Syntheses, structural characterization and spectroscopic studies of cadmium(II)-metal(II) cyanide complexes with 4-(2-aminoethyl)pyridine

NASA Astrophysics Data System (ADS)

Karaağaç, Dursun; Kürkçüoğlu, Güneş Süheyla; Şenyel, Mustafa; Hökelek, Tuncer

2017-02-01

Three new cadmium(II)-metal(II) cyanide complexes, [Cd(4aepy)2(H2O)2][Ni(CN)4] (1), [Cd(4aepy)2(H2O)2][Pd(CN)4] (2) and [Cd(4aepy)2(H2O)2][Pt(CN)4] (3) [4aepy = 4-(2-aminoethyl)pyridine], have been synthesized and characterized by elemental, thermal, FT-IR and Raman spectral analyses. The crystal structures of 1 and 2 have been determined by single crystal X-ray diffraction technique, in which they crystallize in the monoclinic system and C2/c space group. The M(II) [M(II) = Ni(II), Pd(II) and Pt(II)] ions are coordinated with the carbon atoms of the four cyanide groups in the square planar geometries and the [M(CN)4]2- ions act as counter ions. The Cd(II) ions display an N4O2 coordination sphere with a distorted octahedral geometry, the nitrogen donors belonging to four molecules of the organic 4aepy that act as unidentate ligands and two oxygen atoms from aqua ligands. 3D supramolecular structures of 1 and 2 were occurred by M⋯π and hydrogen bonding (Nsbnd H⋯N and Osbnd H⋯N) interactions. Vibrational assignments of all the observed bands were given and the spectral properties were also supported the crystal structures of the complexes. A possible decompositions of the complexes were investigated in the temperature range 30-800 °C in the static atmosphere.

Skeletal effects in Angle Class II/1 patients treated with the functional regulator type II : Cephalometric and tensor analysis.

PubMed

Schulz, Simone; Koos, Bernd; Duske, Kathrin; Stahl, Franka

2016-11-01

The purpose of this work was to employ both cephalometric and tensor analysis in characterizing the skeletal changes experienced by patients with Angle Class II/1 malocclusion during functional orthodontic treatment with the functional regulator type II. A total of 23 patients with Class II/1 malocclusion based on lateral cephalograms obtained before and after treatment with the functional regulator type II were analyzed. Another 23 patients with Angle Class II/1 malocclusion who had not undergone treatment were included as controls. Our cephalometric data attest to significant therapeutic effects of the functional regulator type II on the skeletal mandibular system, including significant advancement of the mandible, increases in effective mandibular length with enhancement of the chin profile, and reduction of growth-related bite deepening. No treatment-related effects were observed at the cranial-base and midface levels. In addition, tensor analysis revealed significant stimulation of mandibular growth in sagittal directions, without indications of growth effects on the maxilla. Its growth-pattern findings differed from those of cephalometric analysis by indicating that the appliance did promote horizontal development, which supports the functional orthodontic treatment effect in Angle Class II/1 cases. Tensor analysis yielded additional insights into sagittal and vertical growth changes not identifiable by strictly cephalometric means. The functional regulator type II was an effective treatment modality for Angle Class II/1 malocclusion and influenced the skeletal development of these patients in favorable ways.

Pharmacologically significant complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) of novel Schiff base ligand, (E)-N-(furan-2-yl methylene) quinolin-8-amine: Synthesis, spectral, XRD, SEM, antimicrobial, antioxidant and in vitro cytotoxic studies

NASA Astrophysics Data System (ADS)

Shakir, M.; Hanif, Summaiya; Sherwani, Mohd. Asif; Mohammad, Owais; Al-Resayes, Saud I.

2015-07-01

A novel series of metal complexes of the types, [ML2(H2O)2]Cl2 and [ML2]Cl2 [M = Mn(II), 1; Co(II), 2; Ni(II), 3; Cu(II), 4; and Zn(II), 5] were synthesized by the interaction of ligand, L (E)-N-(furan-2-yl methylene) quinolin-8-amine, derived from the condensation of 2-furaldehyde and 8-aminoquinoline. The synthesized ligand and its metal complexes were characterized on the basis of results obtained from elemental analysis, ESI-MS, XRD, SEM, TGA/DTA, FT-IR, UV-Vis, magnetic moment and 1H and 13C NMR spectroscopic studies. EPR parameters were recorded in case of complex 4. The comparative in-vitro antimicrobial activities against various pathogens with reference to known antibiotics and antioxidant activity against standard control at variable concentrations revealed that the metal complexes show enhanced antimicrobial and free radical scavenging activities in general as compared to free ligand. However, the complexes 1 and 5 have shown best antioxidant activity among all the metal complexes. Furthermore, comparative in-vitro antiproliferative activity on ligand and its metal chelates performed on MDA-MB-231 (breast carcinoma), KCL22 (blood lymphoid carcinoma), HeLa (cervical carcinoma) cell lines and normal cells (PBMC) revealed that metal chelates show moderate to good activity as compared to ligand where as complex 1 seems to be the most promising one possessing a broad spectrum of activity against all the selected cancer cell lines with IC50 < 2.10 μM.

Crystal structures of copper(II) chloride, copper(II) bromide, and copper(II) nitrate complexes with pyridine-2-carbaldehyde thiosemicarbazone

NASA Astrophysics Data System (ADS)

Chumakov, Yu. M.; Tsapkov, V. I.; Jeanneau, E.; Bairac, N. N.; Bocelli, G.; Poirier, D.; Roy, J.; Gulea, A. P.

2008-09-01

The crystal structures of chloro-(2-formylpyridinethiosemicarbazono)copper dimethyl sulfoxide solvate ( I), bromo-(2-formylpyridinethiosemicarbazono)copper ( II), and (2-formylpyridinethiosemicarbazono)copper(II) nitrate dimethyl sulfoxide solvate ( III) are determined using X-ray diffraction. In the crystals, complexes I and II form centrosymmetric dimers in which the thiosemicarbazone sulfur atom serves as a bridge and occupies the fifth coordination site of the copper atom of the neighboring complex related to the initial complex through the center of symmetry. In both cases, the coordination polyhedron of the complexing ion is a distorted tetragonal bipyramid. Complex III in the crystal structure forms polymer chains in which the copper atom of one complex forms the coordination bond with the thicarbamide nitrogen atom of the neighboring complex. In this structure, the coordination polyhedron of the central atom is an elongated tetragonal bipyramid. It is established that complexes I III at a concentration of 10-5 mol/l selectively inhibit the growth of 60 to 90 percent of the cancer tumor cells of the human myeloid leukemia (HL-60).

Parametrization of a force field for metals complexed to biomacromolecules: applications to Fe(II), Cu(II) and Pb(II)

NASA Astrophysics Data System (ADS)

David, Laurent; Amara, Patricia; Field, Martin J.; Major, François

2002-08-01

Although techniques for the simulation of biomolecules, such as proteins and RNAs, have greatly advanced in the last decade, modeling complexes of biomolecules with metal ions remains problematic. Precise calculations can be done with quantum mechanical methods but these are prohibitive for systems the size of macromolecules. More qualitative modeling can be done with molecular mechanical potentials but the parametrization of force fields for metals is often difficult, particularly if the bonding between the metal and the groups in its coordination shell has significant covalent character. In this paper we present a method for deriving bond and bond-angle parameters for metal complexes from experimental bond and bond-angle distributions obtained from the Cambridge Structural Database. In conjunction with this method, we also introduce a non-standard energy term of gaussian form that allows us to obtain a stable description of the coordination about a metal center during a simulation. The method was evaluated on Fe(II)-porphyrin complexes, on simple Cu(II) ion complexes and a number of complexes of the Pb(II) ion.

The PIP-II Conceptual Design Report

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

Ball, M.; Burov, A.; Chase, B.

2017-03-01

The Proton Improvement Plan-II (PIP-II) encompasses a set of upgrades and improvements to the Fermilab accelerator complex aimed at supporting a world-leading neutrino program over the next several decades. PIP-II is an integral part of the strategic plan for U.S. High Energy Physics as described in the Particle Physics Project Prioritization Panel (P5) report of May 2014 and formalized through the Mission Need Statement approved in November 2015. As an immediate goal, PIP-II is focused on upgrades to the Fermilab accelerator complex capable of providing proton beam power in excess of 1 MW on target at the initiation of themore » Long Baseline Neutrino Facility/Deep Underground Neutrino Experiment (LBNF/DUNE) program, currently anticipated for the mid- 2020s. PIP-II is a part of a longer-term goal of establishing a high-intensity proton facility that is unique within the world, ultimately leading to multi-MW capabilities at Fermilab....« less