The structure of the neutral heterometal oxide cluster dodecaaqua-di-μ(3)-hydroxido-deca-μ(2)-hydroxido-octacosaoxidotetracobalt(II)dodecamolybdenum(V) dodecahydrate, [Mo(12)O(28)(μ(2)-OH)(10)(μ(3)-OH)(2){Co(H(2)O)(3)}(4)], is virtually identical to the previously reported Ni(II) analogue [Mo(12)O(28)(μ(2)-OH)(10)(μ(3)-OH)(2){Ni(II)(H(2)O)(3)}(4)] [Müller, Beugholt, Kögerler, Bögge, Budko & Luban (2000). Inorg. Chem. 39, 5176-5177], the first molecular magnet to exhibit signs of magnetostriction. The formation kinetics of the neutral cluster species, ...

Na(+),K(+)-adenosine triphosphatase (NKA) is the first P-type ion translocating adenosine triphosphatase (ATPase) ever identified, and the significance of this class of proteins was highlighted by the 1997 Nobel Prize in Chemistry awarded to Jens C. Skou for the discovery in 1957. More than half a century passed between the initial ...

Freshwater fish Oreochromis niloticus were individually acutely exposed to different concentrations (0, 0.1, 0.5, 1.0, and 1.5 μg/mL) of Cd(2+) , Cr(6+) , and Ag(+) for 96 h and 0.05 μg/mL concentration of the same metals for different periods (0, 5, 10, 20, and 30 days) chronically. Following each experimental ...

Eight new sesterterpenes (2, 5, and 10-15), including structurally related pentaprenyl hydroquinones (2 and 5), and seven known ones of the same structural classes were isolated from the sponge Coscinoderma sp., collected from Chuuk Island, Micronesia. On the basis of the results of combined spectroscopic analyses, the new compounds were ...

An acute (96 h-0.1, 0.5, 1.0, 1.5 μg/ml) and chronic (up to 30 days-0.05 μg/ml) protocols of Cu and Zn were applied to freshwater fish Oreochromis niloticus to investigate these essential metal effects on the activities of gill, kidney and muscle Na(+)/K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase. In vitro effects of both metals (20 min-0.1, 0.5, 1.0, ...

The indole alkaloid cyclopiazonic acid (CPA) is one of the few known nanomolar inhibitors of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) besides the anticancer drug thapsigargin and the antiplasmoidal terpenoid artemisinin. Due to its less complex structure CPA represents an attractive lead structure for the development of novel antimalarial drugs or for ...

Ca(2+)-ATPases are ATP-driven membrane pumps that are responsible for the transport of Ca(2+) ions across the membrane. The Listeria monocytogenes Ca(2+)-ATPase LMCA1 has been crystallized in the Ca(2+)-free state stabilized by AlF(4)(-), representing an occluded E2-P(i)-like state. The crystals belonged to space group P2(1)2(1)2 and a complete data set extending ...

TcHMA4 (GenBank no. AJ567384), a Cd/Zn transporting ATPase of the P(1B)-type (=CPx-type) was isolated and purified from roots of the Cd/Zn hyperaccumulator Thlaspi caerulescens. Optimisation of the purification protocol, based on binding of the natural C-terminal His-tag of the protein to a Ni-IDA metal affinity column, yielded pure, active TcHMA4 ...

OBJECTIVE: To compare long-term microtensile bond strength of zirconia, surface-modified via a novel treatment, to current surface conditioning methods for zirconia, when resin bonded to dental composite. METHODS: Two ProCAD (porcelain) and 10 sintered ZirCAD (ZrO(2)) blocks (18mm×14mm×12mm) were obtained from manufacturers. Twelve Herculite XRV composite blocks were fabricated (18mm×14mm×12mm). ...

In a pre-experiment, Agaricus bisporus mycelia grown in PDL medium were found to have a substantial ability to tolerate and accumulate heavy metals. In the study, we investigated changes in the contents of soluble protein and thiol compounds as well as the activities of antioxidant enzymes caused by copper, zinc, ...

Si-Sb-Te materials including Te-rich Si(2)Sb(2)Te(6) and Si(x)Sb(2)Te(3) with different Si contents have been systemically studied with the aim of finding the most suitable Si-Sb-Te composition for phase change random access memory (PCRAM) use. Si(x)Sb(2)Te(3) shows better thermal stability than Ge(2)Sb(2)Te(5) or Si(2)Sb(2)Te(6) in that Si(x)Sb(2)Te(3) does not have serious Te ...

Municipal solid waste incineration (MSWI) bottom ash contains a considerable amount of heavy metals. The occurrence and uneven distribution of these heavy metals in bottom ash can increase the complexity of such residues in terms of long-term behavior upon landfilling or recycling. Bottom ashes sampled from three stoker-type incinerators in ...

As common engineered nanomaterials, TiO(2) nanoparticles (nTiO(2)) are usually perceived as non-toxic, and have already been widely used in many products and applications. Such a perception might have been shaped by some short-term studies that revealed no/low toxicity of nTiO(2) to cells and eco-relevant organisms. However, given the ultimate release ...

One monitoring station is insufficient to characterize the high spatial variation of traffic-related heavy metals within cities. We tested moss bags (Hylocomium splendens), deployed in a dense network, for the monitoring of metals in outdoor air and characterized metals' long-term spatial distribution and its determinants in Girona, Spain. Mosses were ...

We have performed molecular dynamics (MD) simulations to elucidate, in atomic detail, the mechanism by which the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) is activated by Ca(2+). Crystal structures suggest that activation of SERCA occurs when the cytoplasmic head-piece, in an open (E1) conformation stabilized by Ca(2+), undergoes a large-scale open-to-closed (E1 ...

A series of platinum(II) complexes bearing tridentate cyclometalated C^N^N (C^N^N=6-phenyl-2,2'-bipyridine and π-extended R-C^N^N=3-[6'-(naphthalen-2''-yl)pyridin-2'-yl]isoquinoline) ligands with fluorene units have been synthesised and their photophysical properties have been studied. The fluorene units are incorporated into the cyclometalated ligands by a Suzuki coupling reaction. An increase in the π-conjugation of the cyclometalated ligands ...

Tanshinone IIA (Tan IIA) is one of the key components of Salvia miltiorrhiza Bunge that has been widely used for various cardiovascular and cerebrovascular disorders in Asian countries. Many studies have reported that Tan IIA has antioxidative properties, but whether Tan IIA can rescue neurons from oxidative insult has never ...

Phytochelatins (PC) are metal-binding ligands synthesized by algae in response to elevated concentrations of various metals, such as Pb. Kinetics of PC synthesis and Pb accumulation in Chlamydomonas reinhardtii were investigated as a function of [Pb(2+)]=10(-11)-10(-7)M (pPb11-pPb7.1) in the exposure medium for up to 6h. The role of PC in ...

The 1,2,4-trimethyltriazolylidene (ditz) ligand allows the preparation of homo- and heterodimetallic complexes of Pt(2) and Ir-Pt. These two complexes have been characterized by means of spectroscopic and diffractommetric techniques. The catalytic activity of these complexes, together with that of other Pt-based compounds, has been explored in the cyclization-addition of alkynyl ...

A novel orange-yellow emitting Sr3Al2O5Cl2:Eu(2+), Tm(3+) phosphor with bright and long persistent luminescence (LPL) has been newly developed. The incorporation of Tm(3+) into the Sr3Al2O5Cl2:Eu(2+) as an auxiliary activator dominates its long persistent luminescence and thermoluminescence characteristics to a large extent. The emissions in Sr3Al2O5Cl2:Eu(2+), Tm(3+) for both fluorescence and ...

A series of heteropolynuclear Pt-Tl-Fe complexes have been synthesized and structurally characterized. The final structures strongly depend on the geometry of the precursor and the Pt/Tl ratio used. Thus, the anionic heteroleptic cis-configured [cis-Pt(C(6)F(5))(2)(C≡CFc)(2)](2-) and [Pt(bzq)(C≡CFc)(2)](-) (Fc = ferrocenyl) complexes react with Tl(+) to form discrete octanuclear (PPh(3)Me)(2)[{trans,cis,cis-PtTl(C(6)F(5))(2)(C≡CFc)(2)}(2)] (1), [PtTl(bzq)(C≡CFc)(2)](2) ...

The electronic transport properties of a single benzene molecule connected to gold and platinum electrodes through the direct Au-C or Pt-C bond are investigated by using a self-consistent ab initio approach that combines the non-equilibrium Green's function (NEGF) formalism with density functional theory (DFT). Our calculations show that the benzene ...

The cytostatic compounds cis-[Pt(A9pyp)(dmso)Cl(2)] (1) and [Pt(A9pyp)(dmso)(cbdca)] (2) (A9pyp=(E)-[1-(9-anthryl)-3-(2-pyridyl)-2-propenone) as carrier ligand; cbdca=cyclobutane dicarboxylate) have been found to add water across the enone C==C bond of the ligand A9pyp. The water addition occurs in the presence of carbonate buffer, and has been followed in detail using NMR and ESI-MS spectroscopy. ...

Rarely-observed polycrystalline twinned Pt nanoparticles (NPs) and length-controlled Pt nanorods (NRs) with exposed high index facets were prepared through an unexpectedly catalytic growth approach from low-cost Mn(3)O(4) NPs. The as-prepared Pt NRs exhibit higher catalytic activity and better stability for the oxidization of methanol than commercial Pt/C catalysts, indicating the ...

The photodecomposition of the anticancer complex trans,trans,trans-[Pt(N(3))(2)(OH)(2)(NH(3))(2)] in acidic aqueous solution, as well as in phosphate-buffered saline (PBS), induced by UVA light (centred at λ = 365 nm) has been studied by multinuclear NMR spectroscopy. We show that the photoreaction pathway in PBS, which involves azide release, differs from that ...

In many previous studies, nonaqueous synthesis of Pt nanocubes with tunable size has been achieved by the use of metal carbonyls (e.g., Fe(CO)(5), Co(2)(CO)(8), W(CO)(6)). The presence of zero-valent metals in the carbonyls was demonstrated as the key factor to the nanocube formation but the role of CO was entirely ...

A platinum(II)-based major groove binder [Pt(II)(C^N)(C≡NR)(2)](+) (HC^N = 2-phenylpyridine (phpy), R = 2-naphthyl) was identified as a potent human topoisomerase IIα poison. It stabilizes the covalent TopoIIα-DNA cleavage complex and induces cancer cell death with potency significantly higher than the widely clinically used TopoIIα poison Vp-16.

The excited-state structure of a dinuclear platinum(II) complex with tert-butyl substituted pyrazolate bridging units, [Pt(ppy)(μ-(t)Bu(2)pz)](2) (ppy = 2-phenylpyridine; (t)Bu(2)pz = 3,5-di-tert-butylpyrazolate) is studied by X-ray transient absorption (XTA) spectroscopy to reveal the transient electronic and nuclear geometry. DFT calculations predict that the lowest energy triplet excited state, assigned to a ...

The adsorption and reaction of ethylene on Pt/CeO(2-x)/Cu(111) model catalysts were studied by means of high resolution photoelectron spectroscopy (HR-PES) in conjunction with resonant photoemission spectroscopy (RPES). The dehydrogenation mechanism is compared to the HR-PES data obtained on a Pt(111) single crystal under identical conditions. It was found that the ...

The structural geometry, electronic structure, photophysical properties, and the fluxional behavior of a series of A-frame diplatinum alkynyl complexes, [Pt(2)(μ-dppm)(2)(μ-C≡CR)(C≡CR)(2)](+) [R = (t)Bu (1), C(6)H(5) (2), C(6)H(4)Ph-p (3), C(6)H(4)Et-p (4), C(6)H(4)OMe-p (5); dppm = bis(diphenylphosphino)methane], have been studied by density functional theory (DFT) and time-dependent TD-DFT associated with conductor-like polarizable ...

In situ X-ray absorption spectroscopy (XAS) at the Pt L(3) edge is a useful probe for Pt-O interactions at polymer electrolyte membrane fuel cell (PEMFC) cathodes. We show that XAS using the high energy resolution fluorescence detection (HERFD) mode, applied to a well-defined monolayer Pt/Rh(111) sample where the bulk penetrating ...

A series of new mesomorphic platinum(II) complexes 1-4 bearing pyridyl pyrazolate chelates are reported herein. In this approach, pyridyl azolate ligands have been strategically functionalized with tris(alkoxy)phenyl groups with various alkyl chain lengths. As a result, they are ascribed to a class of luminescent metallomesogens that possess distinctive morphological properties, ...

By combining the iridium(III) ppy-type complex (Hppy=2-phenylpyridine) with a square-planar platinum(II) unit, some novel phosphorescent oligometallaynes bearing dual metal centers (viz. Ir(III) and Pt(II)) were developed by combining trans-[Pt(PBu(3))(2)Cl(2)] with metalloligands of iridium possessing bifunctional pendant acetylene groups. Photophysical and computational studies indicated that the phosphorescent excited states arising from ...

New palladium and platinum metallacycles have been synthesized by reaction between a 2,7-diazapyrenium-based ligand and Pd(II) and Pt(II) complexes. The inclusion complexes between the metallacycles and polycyclic aromatic hydrocarbons (PAHs) in CD(3)NO(2) and D(2)O were studied by NMR spectroscopy. The structures of the inclusion complexes of the Pt metallacycle as ...

To improve the activity of Au/TiO(2) catalysts toward hydrogenation without decreasing chemoselectivity, a number of isolated and supported Au, Pt, and Au-Pt nanoparticles have been investigated by means of density functional theory (DFT) calculations. H(2) dissociation on Pt and Au-Pt nanoparticles is considerably faster than that on Au, because H(2) ...

Adsorption and decomposition of cyclohexanone (C(6)H(10)O) on Pt(111) and on two ordered Pt-Sn surface alloys, (2 × 2)-Sn/Pt(111) and (√3 × √3)R30°-Sn/Pt(111), formed by vapor deposition of Sn on the Pt(111) single crystal surface were studied with TPD, HREELS, AES, LEED, and DFT calculations with vibrational analyses. Saturation coverage of ...

The kinetics of the oxidation of NO by O(2) was studied on 1 cm diameter single crystals, Pt(111) and Pt(321), at atmospheric pressure. The surface of the (321) crystal is composed of 20% kink, 20% step, and 60% terrace atoms and simulates small 1-3 nm size Pt particles on supported ...

Pt(pipNC)(2)(phen) [pipNC(-) = 1-(piperidylmethyl)phenyl anion; phen = 1,10-phenanthroline] was prepared by the reaction of cis-Pt(pipNC)(2) with phen. Crystallographic and (1)H NMR data establish that the phen ligand is bidentate, whereas each piperidyl ligand is monodentate and bonded to the platinum at the ortho position of the phenyl group. Acidic conditions ...

A range of androgen conjugates with non-conventional platinum(II) complexes have been synthesised with the aim of targeting tumour cells since many display elevated levels of the androgen receptor. The androgenic platinum conjugates are delivered into selected cells with improved efficiency (when compared to their non-steroidal analogues). The act of conjugating ...

The recently published [(PCN)Pt═O](+) complex is interesting as a unique example of a stable d(6) terminal transition metal oxo complex not stabilized by electron withdrawing ligands and as a model of oxo complexes frequently implicated as key intermediates in various processes of oxygen transfer. In the present work, we report ...

Metal and metal oxide nanocrystals have sparked great interest due to their excellent catalytic, magnetic, and electronic properties. Particularly, the integration of metallic nanocrystals and one-dimensional (1D) electronically conducting carbons to form metal-carbon hybrids can lead to enhanced physical and chemical properties or even the creation of new properties with ...

The cyclometalated complexes [Pt(ppy)R(SMe(2))] or [Pt(bhq)R(SMe(2))], where ppyH = 2-phenylpyridine, bhqH = benzo[h]quinoline and R = methyl or p-tolyl, react with bis(diphenylphosphino)ethane, dppe, in a 1:1 ratio to give the corresponding complexes [Pt(κ(1)-C-ppy)R(dppe)] or [Pt(κ(1)-C-bhq)R(dppe)], in which the ppy or bhq ligands are monodentate and dppe is chelating. The similar ...

The role of alkali cations (Li(+), Na(+), K(+), Cs(+), and Be(2+)) on the blank voltammetric response and the oxidative stripping of carbon monoxide from stepped Pt single-crystal electrodes in alkaline media has been investigated by cyclic voltammetry. A strong influence of the nature of the cation on both the blank ...

In an attempt to establish fundamental structure-activity relationships (SAR) of Pt/Pd-based anti-tumour compounds, we have recently designed monodentate pyridyl amide ligand containing central amide units which possess external metal co-ordinating pyridyl group and internal amide functionality. It was prepared in one step from commercially available compounds in moderate to good ...

The hydrophilic, long-chain diamine PEGda (O,O'-bis(2-aminoethyl)octadeca(ethylene glycol)), when complexed with cis-protected Pt(II) ions afforded water-soluble complexes of the type [Pt(N,N)(PEGda)](NO(3))(2) (N,N = N,N,N',N'-tetramethyl-1,2-diaminoethane (tmeda), 1,2-diaminoethane (en), and 2,2'-bipyridine (2,2'-bipy)) featuring unusual 62-membered chelate rings. Equimolar mixtures containing either the 16-mer duplex DNA D2 or the single-stranded D2a and [Pt(N,N)(PEGda)](2+) were ...

Two dinuclear platinum(II) 4,6-diphenyl-2,2'-bipyridine (C^N^N) complexes (1 and 2) with a rigid bridging ligand cis-1,2-bis(diphenylphosphino)ethylene were synthesized and their photophysical properties were systematically investigated in solution for 1 and 2 and in LB film for 2. Similar to their corresponding mononuclear complexes, both complexes exhibit intense (1)π,π* absorption in the ...

The first example for electrogeneration of a Pt(IV) porphyrin from its Pt(II) form is presented and the Pt(II/IV) and reverse Pt(IV/II) oxidation-reduction processes are elucidated by electrochemistry and thin-layer UV-visible spectroelectrochemistry. Three products, [(TPP˙(+))Pt(II)](+), [(TPP)Pt(IV)](2+) and [(TPP˙(+))Pt(IV)](3+), produced by electrooxidation of the Pt(II) porphyrin have been characterized by in situ ...

We describe a simple method for preparing multimetallic nanoparticles by in situ decomposition of the corresponding Prussian blue analogue, which is adsorbed on carbon black. The example involves the AuNi(0.5)Fe core of the Pt(ML)/Au(1)Ni(0.5)Fe core-shell electrocatalyst for the oxygen reduction reaction. The core contains 3-5 surface atomic layers of Au, ...

High Pt utilization PEMFC electrodes were prepared by an alternative ion-exchange/electrodeposition (AIEE) technique. The results demonstrated that the MEA employing an AIEE electrode with a Pt loading of 0.014 mg Pt cm(-2) exhibits performance approximately 2.2 times larger than that employing a conventional Nafion-bonded Pt/C electrode with a same Pt ...

3-Bromoperylene (BrPer) or N-(2,5-di-tert-butylphenyl)-9-bromo-perylene-3,4-dicarboximide (BrPMI) react with [Pt(PEt(3))(4)] to yield trans-[PtR(PEt(3))(2)Br] (R = Per, 1a; R = PMI, 1b). Neutral and cationic perylenyl complexes containing a Pt(PEt(3))X group have been prepared from 1a,b by substitution of the Br ligand by a variety of other ligands (NCS, CN, NO(3), CN(t)Bu, PyMe). ...