Search results for "SILVER"
showing 10 items of 697 documents
A novel ether core lipid with H-shaped C80-isoprenoid hydrocarbon chain from the hyperthermophilic methanogen Methanothermus fervidus.
1998
Abstract A new ether lipid core (designated as FU) was found in Methanothermus fervidus total lipid. Comparison with caldarchaeol showed lower mobility of FU on TLC and smaller molecular weight (m/z 1298) by 2 mass units on FAB-MS. Treatment of FU with HI followed by displacement with silver acetate afforded long chain alcohol acetate (ROAc), which was further saponified with mild alkali to its free alcohol (ROH). ROH is the long chain alcohol prepared from FU. The molecular weights of ROAc and ROH were shown by MS to be 1354 and 1186, respectively. These results suggested that the molecular formula of ROH was C80H162O4, and ROH had four hydroxyl groups, and one molecule of ROH was bound wi…
Photochemical Synthesis of Water-Soluble Gold Nanorods: The Role of Silver Ions in Assisting Anisotropic Growth
2009
The role of Ag+ ions in the ultraviolet-driven photochemical synthesis of Au nanorods (NRs) in aqueous surfactant mixtures has been investigated in order to elucidate the mechanism that drives anisotropic nanoparticle growth. The samples, grown in the presence of varying amounts of Ag+ ions for scheduled irradiation times, have been characterized by ultraviolet−visible−near infrared (UV−vis−NIR) absorption spectroscopy, analytical transmission electron microscopy (ATEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and extended X-ray absorption fine structure (EXAFS) measurements. Moreover, the time evolution of size and shape distribution has been investigated by stat…
Optimization of ZnO:Al/Ag/ZnO:Al structures for ultra-thin high-performance transparent conductive electrodes
2012
Al-doped ZnO (AZO)/Ag/AZO multilayer coatings (50-70 nm thick) were grown at room temperature on glass substrates with different silver layer thickness, from 3 to 19 nm, by using radio frequency magnetron sputtering. Thermal stability of the compositional, optical and electrical properties of the AZO/Ag/AZO structures were investigated up to 400 °C and as a function of Ag film thickness. An AZO film as thin as 20 nm is an excellent barrier to Ag diffusion. The inclusion of 9.5 nm thin silver layer within the transparent conductive oxide (TCO) material leads to a maximum enhancement of the electro-optical characteristics. The excellent measured properties of low resistance, high transmittanc…
Silver-Russell syndrome associated to Mayer-Rokitansky-Kuster-Hauser syndrome, diabetes and hirsutism
2001
We report an unusual association of two rare conditions, the Silver-Russell syndrome and the Mayer-Rokitansky-Küster-Hauser syndrome, with extra endocrine anomalies. A 15-year old Silver-Russell syndrome girl was referred to our Unit because of primary amenorrhea and hirsutism of adrenal origin. A thorough assessment confirmed previous diagnoses and revealed the presence of diabetes, hyperinsulinism and a complete Mayer-Rokitansky-Küster-Hauser syndrome with an ectopic localization of both ovaries. Although initial medical treatment was not unsatisfactory, future medical, psychological and social implications are expected.
The Silver Voltameter: An Essential Instrument for the Definition of the Unit of Electric Current
2017
We discuss the restoration of a silver voltameter belonging lo the Historical Collection of Physics Instruments of the University of Palermo. We stress the essential role this instrument had in the definition of the unit of electric current.
Will they, won’t they? Dream sequences and virtual consummation in the series Moonlighting
2021
The 1980s series Moonlighting was one of the first dramedies on the small screen; it took its cue from venerable genres like the screwball comedy or the hard-boiled novel (particularly The Thin Man) and translated them to television’s changing structures and aesthetics, participating in what has been termed the second Golden Age of television. However, the Nick and Norah Charles of Moonlighting, David and Maddie, were not married: on the contrary, the series was largely fuelled by the tension between the two leads, who were constantly sparring but were seemingly drawn to one another. Though this romantic tension has long been a staple of the silver screen, translating it into weekly episode…
In Situ Colorimetric Quantification of Silver Cations in the Presence of Silver Nanoparticles
2013
Silver ions (Ag(+)) can be quantified in situ in the presence of AgNPs by using a colorimetric sensing probe (3,3',5,5'-tetramethylbenzidine). Interestingly, it also enables detection of the Ag(+) adsorbed on the AgNP surface. This is relevant to design new methods to make AgNPs while ensuring the total reduction of Ag(+).
Elasticity and yield strength of pentagonal silver nanowires: In situ bending tests
2014
This paper reports in situ mechanical characterization of silver nanowires (Ag NWs) inside a scanning electron microscope using a cantilevered beam bending technique. Measurements consisted in controlled bending of a cantilevered NW by the tip of an atomic force microscope glued to the force sensor. Relatively high degree of elasticity followed by either plastic deformation or fracture was observed in bending experiments. Experimental data were numerically fitted into the model based on the elastic beam theory and values of Young modulus and yield strength were extracted. Measurements were performed on twenty Ag NWs with diameters from 76 nm to 211 nm. Average Young modulus and yield streng…
Preparation and evaluation of lauryl methacrylate monoliths with embedded silver nanoparticles for capillary electrochromatography
2012
In this article, capillary columns constituted by lauryl methacrylate monoliths with embedded silver nanoparticles (AgNPs) were developed and tested. Two incorporation approaches of AgNPs in monoliths were explored. The AgNPs were either photogenerated in situ during polymerization of the monolith by UV irradiation, or incorporated to the polymerization mixture (ex situ). The influence of the AgNP concentration on the morphological and chromatographic properties of the polymer matrix was investigated, and both the in situ and ex situ approaches were comparatively discussed. The morphology of the monoliths was characterized by electron microscopic techniques, and their electrochromatographic…
Ag Nanoparticles for Biomedical Applications—Synthesis and Characterization—A Review
2022
Silver nanoparticles have been intensively studied over a long period of time because they exhibit antibacterial properties in infection treatments, wound healing, or drug delivery systems. The advantages that silver nanoparticles offer regarding the functionalization confer prolonged stability and make them suitable for biomedical applications. Apart from functionalization, silver nanoparticles exhibit various shapes and sizes depending on the conditions used through their fabrications and depending on their final purpose. This paper presents a review of silver nanoparticles with respect to synthesis procedures, including the polluting green synthesis. Currently, the most commonly used cha…