Search results for "Note"
showing 10 items of 10709 documents
Crystal structure of μ-oxido-1,1′κ2 O:O-bis{tetra-μ-oxido-1:2κ2 O:O;1:3κ2 O:O;2:3κ4 O:O-tris[1,2,3(η5)-pentamethylcyclopentadienyl]-trianglo-tri…
2015
The title polynuclear organometallic titanium(IV) oxide, [{Ti3(η5-C5Me5)3(μ-O)4}2(μ-O)], exhibits two Ti3O4 cores bridged by an O atom located on a twofold axis. All metal centers present the typical three-legged piano-stool coordination environment, where one site is occupied by a pentamethylcyclopentadienyl ligand linked in an η5-coordination fashion, while three bridging O atoms fill the other three sites.
Self-Radiolysis of Tritiated Water Stored in Zeolites 4A: Production and Behavior of H 2 and O 2
2015
International audience; Radiolysis of confined water and self-radiolysis of tritiated water give rise to several unanswered questions. To take into account this double specificity, we studied systems of zeolites 4A containing tritiated water at different water loading ratios. Two tritiated waters were synthesized at the volumetric activities of 27 and 60 TBq L −1. For each one, five samples were prepared, differentiated by their water loading ratios, expressed in percentage, close to 4%, 7%, 11%, 14%, and 19%. The study of the radiolysis in those systems revealed a double role of zeolites 4A: first, they increase the decomposition of water. Then they enhance the recombination of the major s…
The functionalization of nanodiamonds (diamondoids) as a key parameter of their easily controlled self-assembly in micro- and nanocrystals from the v…
2014
We detail herein readily accessible processes to control previously unobserved robust self-assemblies of nanodiamonds (diamondoids) in micro- and nanocrystals from their mild vapor deposition. The chemical functionalization of uniform and discernible nanodiamonds was found to be a key parameter, and depending on the type of functional group (hydroxy, fluorine, etc.) and its position on the diamondoid, the structure of the discrete deposits can vary dramatically. Thus, well-defined anisotropic structures such as rod, needle, triangle or truncated octahedron shapes can be obtained, and self-assembled edifices of sizes ranging from 20 nm to several hundred micrometers formed with conservation …
Cytotoxic activity of secondary metabolites derived from Artemisia annua L. towards cancer cells in comparison to its designated active constituent a…
2010
Artemisia annua L. (sweet wormwood, qinhao) has traditionally been used in Chinese medicine. The isolation of artemisinin from Artemisia annua and its worldwide accepted application in malaria therapy is one of the showcase success stories of phytomedicine during the past decades. Artemisinin-type compounds are also active towards other protozoal or viral diseases as well as cancer cells in vitro and in vivo. Nowadays, Artemisia annua tea is used as a self-reliant treatment in developing countries. The unsupervised use of Artemisia annua tea has been criticized to foster the development of artemisinin resistance in malaria and cancer due to insufficient artemisinin amounts in the plant as c…
Radical salts of TTF derivatives with the metal-metal bonded [Re2Cl8]2- anion
2008
Abstract Four new salts of the radical cations of TMTSF (tetramethyltetraselenafulvalene), TMTTF (tetramethyltetrathiafulvalene), BEDT-TTF (bisethylenedithiotetrathia-fulvalene) (ET) and o-Me2TTF (o-4,4′-dimethyltetrathiafulvalene) with the metal–metal bonded dianion [Re2Cl8]2− were synthesized, and their structures and physical properties investigated. The structures of these semiconducting salts feature one-dimensional stacking of the donor molecules interleaved with [Re2Cl8]2− anions and interstitial solvent molecules.
Recent advances on aptamer-based biosensors to detection of platelet-derived growth factor.
2018
Platelet-derived growth factor (PDGF-BB), a significant serum cytokine, is an important protein biomarker in diagnosis and recognition of cancer, which straightly rolled in proceeding of various cell transformations, including tumor growth and its development. Fibrosis, atherosclerosis are certain appalling diseases, which PDGF-BB is near to them. Generally, the expression amount of PDGF-BB increases in human life-threatening tumors serving as an indicator for tumor angiogenesis. Thus, identification and quantification of PDGF-BB in biomedical fields are particularly important. Affinity chromatography, immunohistochemical methods and enzyme-linked immunosorbent assay (ELISA), conventional m…
Surface Defects as a Tool to Solubilize and Functionalize WS 2 Nanotubes
2017
Layered transition metal dichalcogenides contain a number of crystal defects which significantly change their properties may be beneficial or detrimental for a specific application. We have prepared defect-rich multiwalled WS2 nanotubes by reductive sulfidization of W18O49 nanowires that were obtained solvothermally from tungsten chloride in different alcohols. The synthesis of the W18O49 nanowires was monitored and their morphological characteristics (e. g. length, rigidity and aspect ratio) are described in detail. The effect of morphology of the nanowires on the synthesis of WS2 nanotubes was investigated in order to obtain WS2 nanotubes that are highly solvent dispersible. Dispersions o…
From tungsten hexacarbonyl adsorption on TiO2(1 1 0) surface to supported tungsten oxide phases.
2008
Abstract Synchrotron-based photoemission spectroscopies were used to study the adsorption of tungsten hexacarbonyl on (1 1 0) TiO 2 surfaces: experiments using W4f and Ti2p intensities variations show that, at 140 K, the hexacarbonyl growth proceeds via a layer-by-layer mode. Moreover, it was evidenced using both core levels and valence band experiments that, after back to room temperature, W(CO) 6 desorbs without significant decomposition. However, low energy (500 eV) ion (Ar + ) irradiation can allow partial decomposition of tungsten hexacarbonyl molecules leading to sub-carbonyl tungsten molecules. The bonding of sub-carbonyl species to the TiO 2 surface was then stronger than the one of…
A tungsten oxide–lutetium bisphthalocyanine n–p–n heterojunction: from nanomaterials to a new transducer for chemo-sensing
2019
We report on a new hybrid heterojunction gas-sensitive device by combining a molecular material with a metal oxide. WO3 was synthesised via an aerosol-assisted chemical vapour deposition technique from a tungsten hexacarbonyl precursor. Onto an inorganic film, LuPc2 was vacuum evaporated. The morphology of the WO3–LuPc2 hybrid films is dominated by the morphological features of the tungsten oxide film, as shown by scanning electron microscopy and atomic force microscopy. Raman spectroscopy of the device confirms the presence of both materials. The non-linear I–V characteristics demonstrate the existence of an energy barrier at the interface between the inorganic and molecular materials. The…
Effect of bioclimatic area on the composition and bioactivity of Tunisian Rosmarinus officinalis essential oils
2014
The chemical composition of eight Tunisian Rosmarinus officinalis L. populations (A-H) from different bioclimatic areas has been examined by gas chromatography (GC) and GC-mass spectrometry. The essential oils are characterised by high amounts of oxygenated monoterpenes (58.2-71.7%) followed by monoterpene hydrocabons (15.1-26.7%). 1,8-Cineole, camphor, α-pinene and borneol are the main representative components. The antioxidant activity was investigated by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing ability power assay and β-carotene bleaching test. Samples showed antiradical activity by inhibiting DPPH radical with IC50 values ranging from 375.3 to 592.8 μg mL(- 1) for s…