The Mechanical Stability for the Hand-Arm System

The present paper contains a study regarding importance stability in the mechanical systems, mechanical systems are emerging under mechanical vibrations action, it referring especially to the human hand–arm system. Mechanical systems stability is directly influenced of the dumper and the elasticity factors. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

DNA-assisted decoration of single-walled carbon nanotubes with gold nanoparticles for applications in surface-enhanced Raman scattering imaging of cells

Single-walled carbon nanotubes (SWNTs) are 1D nanostructures with distinct physical and chemical properties that have shown great promise for applications in many fields, including biomedicine. Since for biomedical application the water solubility is crucial and SWNTs have low solubility, various methods (including polymer and biopolymer wrapping, chemical modifications) have been developed to solubilize and disperse them in water. Due to their unique optical properties such as photoluminescence in the NIR and strong resonant Raman signatures, they can be used as nanoprobes in biomedical imaging and phototherapies. Furthermore, decoration of SWNTs with noble metal nanoparticles will induce an excellent surface-enhanced Raman scattering (SERS) effect of the nanoparticles-SWNTs composites, with applications in cell imaging. Herein, we present a new and facile strategy for the DNA-assisted decoration of SWNTs with gold nanoparticles (AuNPs) and their application in SERS imaging. By ultrasonication at room temperature of SWNTs with AuNPs functionalized with synthetic DNA, SWNT-AuNPs nanocomposites with enhanced Raman signal were obtained. Among the important advantages of the proposed method are the presence of the free DNA overhangs around the SWNT-AuNPs suitable for post-synthetic modification of nanocomposite through hybridization of complementary DNA strands containing molecules of interest attached by well-developed bio-conjugation chemistry.

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Fluorescence of copper, manganese and antimony ions in phosphate glass host

The paper presents a study based on luminescence characteristics of phosphate glasses containing Cu²⁺, Mn⁴⁺ and Sb³⁺. The glass samples obtained by a wet chemical route belong to Li₂O–BaO–Al₂O₃–La₂O₃–P₂O₅ oxide system. The oxide composition of the glass samples is calculated to obtain a vitreous network composed of metaphosphate chains bonded by modifier ions (Li⁺, Ba²⁺ and La³⁺) and fluorescent ions. The absorption spectra of the samples were acquired in the UV domain in order to establish the excitation wavelength for each fluorescent ion. The absorption peaks of Sb³⁺ ion are ranged at 285 nm and 250 nm, Mn²⁺ ion at 280 nm and 365 nm, Cu²⁺ ion at 295 nm and 313 nm. The luminescence peaks of Cu²⁺, Mn⁴⁺ and Sb³⁺ ions are found in the visible domain at different wavelengths, depending on the oxidation state and coordination symmetry of each fluorescent ion. The fluorescence of Sb³⁺ ion has a strong signal at 450 nm and a weak one at 465 nm, Mn²⁺ ion shows a fluorescence peak at 600 nm and the pair Cu²⁺/Cu⁺ ions reveals a fluorescence emission at 460 nm.     

Fuzzy supervised neurocontrol of electrohydraulic servos

The work presents theoretical and experimental investigations concerning the neuro-fuzzy control of electrohydraulic servos. The control algorithm is built around a neurocontroller designed to optimize a performance index. Whenever the neurocontrol saturates or a system performance parameter decreases, the control scheme switches to a feasible and reliable fuzzy logic control. In accordance with simulation studies developed in previous works of the authors, the neuro-fuzzy controlled system proves often to be better than the corresponding classical PI or LQG systems. We emphasize that the entire control synthesis is thought as a model free approach, thus ensuring reduced design complexity and focusing on increased system robustness. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Ultrastructural Damages to H1N1 Influenza Virus Caused by Vapor Essential Oils

Influenza viruses are transmitted from human to human via airborne droplets and can be transferred through contaminated environmental surfaces. Some works have demonstrated the efficacy of essential oils (EOs) as antimicrobial and antiviral agents, but most of them examined the liquid phases, which are generally toxic for oral applications. In our study, we describe the antiviral activity of Citrus bergamia, Melaleuca alternifolia, Illicium verum and Eucalyptus globulus vapor EOs against influenza virus type A. In the vapor phase, C. bergamia and M. alternifolia strongly reduced viral cytopathic effect without exerting any cytotoxicity. The E. globulus vapor EO reduced viral infection by 78% with no cytotoxicity, while I. verum was not effective. Furthermore, we characterized the EOs and their vapor phase by the head-space gas chromatography–mass spectrometry technique, observing that the major component found in each liquid EO is the same one of the corresponding vapor phases, with the exception of M. alternifolia. To deepen the mechanism of action, the morphological integrity of virus particles was checked by negative staining transmission electron microscopy, showing that they interfere with the lipid bilayer of the viral envelope, leading to the decomposition of membranes. We speculated that the most abundant components of the vapor EOs might directly interfere with influenza virus envelope structures or mask viral structures important for early steps of viral infection.     

Platinum hyperfine interaction and delocalization of solitons in KCP as seen by ESR

Former results of the cw-ESR experiments on the quasi-one-dimensional platinum conductor KCP are analyzed in terms of motionally narrowed hyperfine interaction of a spin-carrying soliton delocalized over 6–10 platinum atoms.     

Syntheses and characterization of nickel(II) dithiocarbamate complexes containing NiS4 and NiS2PN moieties: Nickel sulphide nanoparticles from a single source precursor

In this study, ammonium N-benzyldithiocarbamate was synthesized and used to prepare homoleptic Ni(II) bis(N-benzyldithiocarbamate) (1) and heteroleptic Ni(II) complexes involving isocyanate (2) and cyanide (3) ions. The complexes were characterized by elemental analysis, Fourier transform infra-red (FTIR), and NMR (¹H and ¹³C) spectroscopic techniques. Complex 2 was further characterized by single crystal X-ray diffraction analysis. The FTIR showed bidentate co-ordination for all the complexes as the v(CN) stretching frequency were in the 980–1050 cm^?1 region without any splitting. Thermal decomposition profile of the complexes showed decomposition resulting in the formation of nickel sulphides. The homoleptic complex 1 was utilized as single source precursor (SSP) to prepare Nickel sulphide nanoparticles. The synthesis of the nanoparticles was conducted using different capping molecules (with various alkyl chain lengths), and at different reaction temperature and time. Pure phase Heazlewoodite (Ni₃S₂) nanoparticles were obtained from the X-ray diffraction study. The TEM analysis showed that the type of capping agent, reaction temperature, and time of reaction have significant effect on the morphology and size of the nanoparticles. The optical properties of the nanoparticles were studied using absorption and fluorescence spectroscopies, and they displayed evidence of quantum confinement effect.     

Early transition-metal perfluoroalkyl complexes

Elusive early transition-metal perfluoroalkyl complexes have been isolated and structurally characterized for the first time. Trifluoromethyltrimethylsilane, CF3SiMe3, serves as an excellent trifluoromethyl group-transfer reagent and reacts with the known Ti(IV) fluoride complex Cp2TiF2 to yield the novel Ti(IV) trifluoromethyl fluoride compound, Cp2Ti(CF3)(F) (1). Reaction of complex 1 with trimethylsilyltriflate (Me3SiOTf) affords the Ti(IV) trifluoromethyl triflate complex Cp2Ti(CF3)(OTf) (2). Both titanium perfluoroalkyl compounds have been characterized spectroscopically and by single-crystal X-ray analysis. The Ti-CF3 linkage in these complexes is remarkably robust and shows no evidence of an alpha-fluoride interaction (Ti...F-CF2) between the electrophilic Ti(IV) metal center and any of the C-F bonds in the trifluoromethyl group in the solid state or in solution.