Synthesis, antimicrobial and antiproliferative activity of novel silver(I) tris(pyrazolyl)methanesulfonate and 1,3,5-triaza-7-phosphadamantane complexes

Five new silver(I) complexes of formulas [Ag(Tpms)] (1), [Ag(Tpms)(PPh(3))] (2), [Ag(Tpms)(PCy(3))] (3), [Ag(PTA)][BF(4)] (4), and [Ag(Tpms)(PTA)] (5) {Tpms = tris(pyrazol-1-yl)methanesulfonate, PPh(3) = triphenylphosphane, PCy(3) = tricyclohexylphosphane, PTA = 1,3,5-triaza-7-phosphaadamantane} have been synthesized and fully characterized by elemental analyses, (1)H, (13)C, and (31)P NMR, electrospray ionization mass spectrometry (ESI-MS), and IR spectroscopic techniques. The single crystal X-ray diffraction study of 3 shows the Tpms ligand acting in the N(3)-facially coordinating mode, while in 2 and 5 a N(2)O-coordination is found, with the SO(3) group bonded to silver and a pendant free pyrazolyl ring. Features of the tilting in the coordinated pyrazolyl rings in these cases suggest that this inequivalence is related with the cone angles of the phosphanes. A detailed study of antimycobacterial and antiproliferative properties of all compounds has been carried out. They were screened for their in vitro antimicrobial activities against the standard strains Enterococcus faecalis (ATCC 29922), Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Streptococcus pyogenes (SF37), Streptococcus sanguinis (SK36), Streptococcus mutans (UA159), Escherichia coli (ATCC 25922), and the fungus Candida albicans (ATCC 24443). Complexes 1-5 have been found to display effective antimicrobial activity against the series of bacteria and fungi, and some of them are potential candidates for antiseptic or disinfectant drugs. Interaction of Ag complexes with deoxyribonucleic acid (DNA) has been studied by fluorescence spectroscopic techniques, using ethidium bromide (EB) as a fluorescence probe of DNA. The decrease in the fluorescence of DNA-EB system on addition of Ag complexes shows that the fluorescence quenching of DNA-EB complex occurs and compound 3 is particularly active. Complexes 1-5 exhibit pronounced antiproliferative activity against human malignant melanoma (A375) with an activity often higher than that of AgNO(3), which has been used as a control, following the same order of activity inhibition on DNA, i.e., 3 > 2 > 1 > 5 > AgNO(3)? 4.     

Markov chains on $${{\mathbb {Z}}^+}$$ Z + : analysis of stationary measure via harmonic functions approach

Queueing Systems - We suggest a method for constructing a positive harmonic function for a wide class of transition kernels on $${{\mathbb {Z}}^+}$$ . We also find natural conditions under which...     

Existence of solutions for some non‐Fredholm integro‐differential equations with the bi‐Laplacian

We prove the existence of solutions for some semilinear elliptic equations in the appropriate H⁴ spaces using the fixed‐point technique where the elliptic equation contains fourth‐order differential operators with and without Fredholm property, generalizing the previous results.     

Viscoelastic investigation by ultrasonic shear waves of liquid eutectic mixture methylurea–ammonium sulfamate

Shear impedance of the liquid eutectic mixture CH₃NHCONH₂–NH₄SO₃NH₂ was studied in the temperature range 291.7–313.2 K by using ultrasonic shear waves in the frequency range 12–80 MHz. Ultrasonic technique allowed the determination of the real part of the complex mechanical impedance and of the complex rigidity modulus. The relaxation region was shifted towards higher frequency in comparison to the Maxwell model and was fitted by the modified BEL model.     

Searching for protostars

Summary We present molecular-line observations of young stellar objects (YSOs) suspected to be protostars in the main accretion phase. The aim of this work is to define a list of the best protostellar candidates to be observed in the near future with the ISO spectrometers with the precise scope of searching for the final proof of the infall, theHoly Grail of astrophysics. The sources were mapped in the CS 3?2 and CO 3?2 lines; our data were used to investigate the presence of clumps of materials around these objects and the amount of this material, as well as to detect outflows associated with these objects that would enormously complicate the interpretation of further dynamics studies. Only one of our sources suspected to be protostars resulted to have a good chance of being in the accretion phase and to deserve further spectroscopic measurements. Paper presented at the 6th Cosmic Physics National Conference, Palermo, 3–7 November 1992.     

More on the duality conjecture for entropy numbers

We verify, up to a logarithmic factor, the duality conjecture for entropy numbers in the case where one of the bodies is an ellipsoid. To cite this article: S. Artstein et al., C. R. Acad. Sci. Paris, Ser. I 336 (2003).     

Continuous variable encoding by ponderomotive interaction

Recently it has been proposed to construct quantum error-correcting codes that embed a finite-dimensional Hilbert space in the infinite-dimensional Hilbert space of a system described by continuous quantum variables [D. Gottesman et al., Phys. Rev. A 64, 012310 (2001)]. The main difficulty of this continuous variable encoding relies on the physical generation of the quantum codewords. We show that ponderomotive interaction suffices to this end. As a matter of fact, this kind of interaction between a system and a meter causes a frequency change on the meter proportional to the position quadrature of the system. Then, a phase measurement of the meter leaves the system in an eigenstate of the stabilizer generators, provided that system and meter's initial states are suitably prepared. Here we show how to implement this interaction using trapped ions, and how the encoding can be performed on their motional degrees of freedom. The robustness of the codewords with respect to the various experimental imperfections is then analyzed.     

Ueber den Nachweis der Salpeters?ure in Leichentheilen

Ohne Zusammenfassung     

Den chemisch - toxikologischen Nachweis des Hydrastins

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