Образование акцепторных центров в CdHgTe под воздействием воды и термообработок

Influence storage and boiling in deionized water and heat treatments of epitaxial films CdxHg1-xTe on the Hall and ellipsometric parametres is investigated. Water treatment reduces refractive index of native CdxHg1-xTe oxide from 2.1 to 1.2-1.4. It means that matter with a lower refractive index, such as water, is introduced in the oxide. Boiling in water leads to formation of acceptors in CdxHg1-xTe with concentrations up to 1019 cm-3. Change of medium’s pH from alkaline to the acidic decreases the speed of acceptors formation. Heat treatments after storage in water also leads to formation of acceptors. The conclusion is made, that water medium or water absorbed by native oxide layer leads to formation of acceptors in CdxHg1-xTe. Concentration of acceptors grows with temperature of treatments and quantity of accessible water.

Структурные фазовые превращения при твердофазной реакции в тонких двухслойных пленках Al/Pt

A sequence of phases forming during the solid-phase reaction in Al/Pt bilayer thin films has been investigated by in situ electron diffraction. It is shown that the amorphous PtAl_2 phase forms first during the solid-phase reaction initiated by heating. Upon further heating, PtAl_2, Pt_2Al_3, PtAl, and Pt_3Al crystalline phases sequentially form, which is qualitatively consistent with an effective formation heat model. The content of phases forming during the reaction has been quantitatively analyzed and the structural phase transformations have been examined.

Possibility of using fullerene C240 as the carrier of steroid hormones

Fullerene molecules are created entirely of carbon and form orbicular or ellipsoidal cage shape similar to a hollow tube. The derivatives of fullerenes are classified into the following categories according to their functionalization: endohedral fullerenes with active molecules residing inside the carbon cage, exohedral with wide variety of both inorganic and organic groups existing outside and connected to the fullerenes’ exterior and heterofullerenes when one or more carbon atoms that form the fullerene carbon cage are replaced by a non-carbon atom, i.e. a heteroatom. Fullerene C240belongs to the family of giant fullerenes and is characterized by a greater stability than that of the well-known fullerene C60. This has been proved by observing an increased formation heat that accompanied the decreasing of the carbon cage size.In order to determine the fullerene C240 ability to transport the steroid hormones: estradiol, progesterone, androsterone and their basic structures: estrone, androstane and pregnane, the following parameters, inter alia, have been calculated: energies of stabilization, interaction and deformation of each endohedral complex. The calculations for all chosen structures were carried out with the use of the molecular modeling technique. Based on all available studies, it can be stated that fullerene C240 could be a solution for problems faced by medicine and pharmacy.

Possibility of using fullerene C240 as the carrier of steroid hormones

Fullerene molecules are created entirely of carbon and form orbicular or ellipsoidal cage shape similar to a hollow tube. The derivatives of fullerenes are classified into the following categories according to their functionalization: endohedral fullerenes with active molecules residing inside the carbon cage, exohedral with wide variety of both inorganic and organic groups existing outside and connected to the fullerenes’ exterior and heterofullerenes when one or more carbon atoms that form the fullerene carbon cage are replaced by a non-carbon atom, i.e. a heteroatom. Fullerene C240belongs to the family of giant fullerenes and is characterized by a greater stability than that of the well-known fullerene C60. This has been proved by observing an increased formation heat that accompanied the decreasing of the carbon cage size.In order to determine the fullerene C240 ability to transport the steroid hormones: estradiol, progesterone, androsterone and their basic structures: estrone, androstane and pregnane, the following parameters, inter alia, have been calculated: energies of stabilization, interaction and deformation of each endohedral complex. The calculations for all chosen structures were carried out with the use of the molecular modeling technique. Based on all available studies, it can be stated that fullerene C240 could be a solution for problems faced by medicine and pharmacy.

Effect of Fly Ash Composition and Structure on the Formation of Cement Clinker

In the view of scarce of natural mineral resources and requirement of energy-saving/emission-reducing for cement industry, the natural silicon-aluminum clay as one cement raw material has been gradually replaced by silica-rich industrial wastes, such as, fly ash, a principal solid waste discharged from coal-fired power plants, composed mainly of silica- and alumina-rich glass bead-shaped mineral. Using fly ash to produce cement raw materials, the formation and chemical reactions of cement clinker are affected by the chemical and mineral composition as well as the texture of the fly ash and the paper was focused on it. The empirical formula for formation heat of fly ash-doped cement clinker is revised on the basis of chemical thermodynamics. The results show that with the use of fly ash, in contrast with the traditional ingredients, the formation of varieties of clinker minerals as well as the formation sequence and types of intermediates varied little, while the maximum decomposition temperature of carbonate was lowered by 50 °C approximately, so that both the solid phase reaction temperature and liquid phase sintering point were decreased, which is favorable to the reduction of clinker formation heat. The revised formation heat empirical formula of fly ash-doped clinker could facilitate the thermal calculation of furnaces and the evaluation of thermal efficiency.

Centrosome-intrinsic mechanisms modulate centrosome integrity during fever

The centrosome is critical for cell division, ciliogenesis, membrane trafficking, and immunological synapse function. The immunological synapse is part of the immune response, which is often accompanied by fever/heat stress (HS). Here we provide evidence that HS causes deconstruction of all centrosome substructures primarily through degradation by centrosome-associated proteasomes. This renders the centrosome nonfunctional. Heat-activated degradation is centrosome selective, as other nonmembranous organelles (midbody, kinetochore) and membrane-bounded organelles (mitochondria) remain largely intact. Heat-induced centrosome inactivation was rescued by targeting Hsp70 to the centrosome. In contrast, Hsp70 excluded from the centrosome via targeting to membranes failed to rescue, as did chaperone inactivation. This indicates that there is a balance between degradation and chaperone rescue at the centrosome after HS. This novel mechanism of centrosome regulation during fever contributes to immunological synapse formation. Heat-induced centrosome inactivation is a physiologically relevant event, as centrosomes in leukocytes of febrile patients are disrupted.