On strongly stable normal operators in Krein spaces

For bounded normal operators in Krein spaces we give a necessary and sufficient condition for strong stability. The same result for unitary operators was obtained by M.G.Krein [1] (see also [2]). For selfadjoint operators we refer to the papers of P.Jonas, H.Langer [3] and H.Langer [4].     

Standard enthalpies of formation of perfluoro(2-methyl-3-oxa)hexanoic and perfluoro(2,5-dimethyl-3,6-dioxa)nonanoic acids

The energies of combustion of perfluoro(2-methyl-3-oxa)hexanoic and perfluoro(2,5-dimethyl-3,6-dioxa)nonanoic acids are for the first time measured in a calorimeter with a rotating platinized bomb and used to calculate the standard enthalpies of formation of these compounds in the liquid state. Based on the enthalpies of formation, the contribution from the [-CF₂OCF(CF₃)-] group to the enthalpies of formation of perfluoro acids is calculated.     

Comparative analysis of cytotoxic effects and intracellular accumulation of platinum(IV) nitroxyl complexes

Russian Chemical Bulletin - The relationship between the lipophilicity, cytotoxic effects, and intracellular accumulation for potential antitumor agents, viz., amino complexes of platinum(IV) with...     

The standard enthalpy of formation of silver pivalate

The standard enthalpy of combustion of crystalline silver pivalate, (CH₃)₃CC(O)OAg (AgPiv), was determined in an isoperibolic calorimeter with a self-sealing steel bomb, Δ_c H ⁰ (AgPiv, cr)= −2786.9±5.6 kJ mol⁻¹. The value of standard enthalpy of formation was derived for crystalline state: Δ_f H ⁰(AgPiv,cr)= −466.9±5.6 kJ mol⁻¹. Using the enthalpy of sublimation, measured earlier, the enthalpy of formation of gaseous dimer was obtained: Δ_f H ⁰(Ag₂Piv₂,g)= −787±14 kJ mol⁻¹. The enthalpy of reaction (CH₃)₃CC(O)OAg(cr)=Ag(cr)+(CH₃)₃CC(O)O^.(g) was estimated, Δ_r H ⁰=202 kJ mol⁻¹.     

Sulfate-Sulfide Equilibrium and Contents of Heavy Metals in Bed Sediments in Fresh and Salty Lakes of Altay Region

Sediment quality criteria (SQC) is based on the assumption of bioavailability of heavy metals. Heavy metals are connecting in strong inert complexes are less toxicity and less availability for hydrobions.     

Ultraheavy Yukawa-bound states of fourth-generation at Large Hadron Collider

A study of bound states of the fourth-generation quarks in the range of 500?C700 GeV is presented, where the binding energies are expected to be mainly of Yukawa origin, with QCD subdominant. Near degeneracy of their masses exhibits a new ??isospin??. The production of a colour-octet, isosinglet vector meson via $q\bar q \to \omega_8$ is the most interesting. Its leading decay modes are $\pi_8^\pm W^\mp$ , $\pi_8^0Z^0$ , and constituent quark decay, with $q\bar q$ and $t\bar t'$ and $b\bar b'$ subdominant. The colour octet, isovector pseudoscalar ?? ₈ meson decays via constituent quark decay, or to Wg. This work calls for more detailed study of fourth-generation phenomena at LHC.     

The enthalpy of formation of fullerene fluoride C<Subscript>60</Subscript>F<Subscript>18</Subscript> and the C-F bond energy

The enthalpy of combustion of crystalline fullerene fluoride C₆₀F₁₈ was determined in an isoperibolic calorimeter with a rotating platinized bomb, and the enthalpy of formation of the compound was calculated. The enthalpy of sublimation of C₆₀F₁₈ measured earlier was used to calculate the enthalpy of formation of fullerene fluoride in the gas phase and the mean enthalpy of dissociation of C-F bonds in this compound.     

Standard enthalpy of formation of fullerene bromide C60Br24

The enthalpy of the combustion of C₆₀Br₂₄ · 2Br₂ has been measured using a rotating-bomb calorimeter as follows: Δ _c H ⁰(C₆₀Br₂₄ · 2Br₂, cr) = (?25986 ± 166) kJ/mol. The result has been used to calculate the standard enthalpy of formation, ΔfH ⁰(C₆₀Br₂₄ · 2Br₂, cr) = (2375 ± 166) kJ/mol. The enthalpies of formation of C₆₀Br₂₄ (cr) and dissociation of the C-Br bond have been estimated. The latter value has been compared with enthalpies for the C-X (X = H, F, Cl, Br) bonds in fullerene derivatives and organic compounds.     

Cytostatic action of triazole and oxazolidinone derivatives

We synthesized a number of derivatives of 1,2,3-benzotriazole, 1,2,4-triazole, and oxazolidine-2-one derivatives, among which compounds suppressing the growth of the tumor cells HeLa and H1299 were revealed. The studies of the effect of these compounds on the cell cycle and activity of caspase dependent degradation of poly(ADP-ribose) polymerase showed that these compounds at the IC₅₀ doses exhibit cytostatic effect on tumor cells. In the MCF7 cells, these compounds induce an increase in expression of the tumor suppressor p53.