The topology of systems of hyperspaces determined by dimension functions

Given a non-degenerate Peano continuum $X$, a dimension function $D:2^X_*\to[0,\infty]$ defined on the family $2^X_*$ of compact subsets of $X$, and a subset $\Gamma\subset[0,\infty)$, we recognize the topological structure of the system (2^X,\D_{\le\gamma}(X))_{\alpha\in\Gamma}, where $2^X$ is the hyperspace of non-empty compact subsets of $X$ and $D_{\le\gamma}(X)$ is the subspace of $2^X$, consisting of non-empty compact subsets $K\subset X$ with $D(K)\le\gamma$.Comment: 12 page

Renormalized spectral function for Co adatom on the Pt(111) surface

The strong Coulomb correlations effects in the electronic structure of magnetic Co adatom on the Pt(111) surface have been investigated. Using a realistic five d-orbital impurity Anderson model at low temperatures with parameters determined from first-principles calculations we found a striking change of the electronic structure in comparison with the LDA results. The spectral function calculated with full rotationally invariant Coulomb interaction is in good agreement with the quasiparticle region of the STM conductance spectrum. Using the calculated spin-spin correlation functions we have analyzed the formation of the magnetic moments of the Co impurity orbitals.Comment: 4 pages, 4 figure

Spatial inversion of gyrotropy parameter in conductivity tensor and charge transport peculiarities

Charge transfer is discussed for the case when gyrotropy parameter (Hall coefficient) varies along transport л-direction and inverses its sign. This situation takes place in contacts of the serially joined materials having electron and hole types of conductivity. Spatial inhomogeneity of conductivity and inversion of Hall coefficient sign are analyzed in terms of electric potential and current density distribution. It is shown that under inhomogeneous magnetic field the steady current skinning takes place in plate sample

Grain yield response of facultative and winter triticale for late autumn sowing in different weather conditions

Climate change is affecting the growing conditions of winter cereals. Peculiarities of organogenesis and their impact in grain yield of facultative triticale depend on different nitrogen fertilization can help to avoid adverse effects of unfavorable conditions. Field experiment was conducted in zone of the Right-Bank Forest-Steppe of Ukraine. The experiment included 2 late autumns sowing periods and fertilization system with few variants of nitrogen fertilization applied in spring. Features of organogenesis of two winter varieties and facultative triticale Pidzimok kharkivskiy were determined by apical meristem microscopy from emergence till heading. Was established process of apical meristem differentiation in facultative triticale has non-linear relation between temperature and number of spikelets. The efficiency of apical meristem differentiation reaches its maximum at 12 °C. Grain yield of triticale varieties depend on studied factors but main impact had weather conditions. Grain yield of facultative triticale significantly exceeds winter varieties and had a lesser difference between sowing period than winter cultivars. Crops in the first sowing period were more productive than in the second. Facultative triticale has great productivity potential in late autumn sowing and can realize it in various conditions. Reduced yields in late sowing are lower than in winter cultivars

Nanoskyrmion engineering with spsp-electron materials: Sn monolayer on SiC(0001) surface

Materials with $sp$-magnetism demonstrate strongly nonlocal Coulomb interactions, which opens a way to probe correlations in the regimes not achievable in transition metal compounds. By the example of Sn monolayer on SiC(0001) surface, we show that such systems exhibit unusual but intriguing magnetic properties at the nanoscale. Physically, this is attributed to the presence of a significant ferromagnetic coupling, the so-called direct exchange, which fully compensates ubiquitous antiferromagnetic interactions of the superexchange origin. Having a nonlocal nature, the direct exchange was previously ignored because it cannot be captured within the conventional density functional methods and significantly challenges ground state models earlier proposed for Sn/SiC(0001). Furthermore, heavy adatoms induce strong spin-orbit coupling, which leads to a highly anisotropic form of the spin Hamiltonian, in which the Dzyaloshinskii-Moriya interaction is dominant. The latter is suggested to be responsible for the formation of a nanoskyrmion state at realistic magnetic fields and temperatures.Comment: 4 pages, supplemental materia

Генетические особенности и маркеры меланомы кожи

Melanoma remains the most deadly form of malignant skin disease with high risk of metastases. Metastatic melanoma is prognostic highly unfavorable and resistant to traditional chemotherapy and biologic treatment. There is a great progress in understanding of the molecular mechanisms underlying melanoma initiation and progression. The external (ultraviolet irradiation) and internal (genetic) factors are involved in melanoma genesis. 5–14 % of melanoma cases occur in familial context due to genetic predisposition risk factors. Among them rare germinal mutations in the cell cycle genes regulators CDKN2A and CDK4 and in the master gene of melanocyte homeostasis MITF, as well as single nucleotide polymorphisms of several low-penetrated genes, namely MC1R, have been identified. The main cell signaling pathways and oncogene driver mutations are involved in melanoma pathogenesis. RAS / RAF / MEK / ERK cascade is hyperactivated in 75 % of cutaneous melanoma cases. Activation of PI3K / AKT / mTOR signaling pathway is important for melanoma progression. Recent studies revealed that melanomas are genetically and phenotypically heterogeneous tumors. Spectrum of chromosomal alterations and activating mutations corresponding to tumor molecular portraits varies in melanomas of different location. Most of cutaneous melanomas contain BRAF (50 %) or NRAS (20 %) mutations, and NRAS mutations occur on chronically sun-exposed skin. Activating KIT mutations have been reported in approximately 20–30 % of certain subtypes of melanoma, including acral and mucosal, and melanoma that develop on photodamaged skin. Cutaneous metastatic melanoma derive from preexisting nevi in 25 % of cases, molecular mechanisms of nevi malignization are discussed. Deepsequencing approaches of melanoma samples of different melanoma types highlighted new melanoma driver genes, that are damaged due to tumorigenic effects of ultraviolet: PPP6C, RAC1, SNX31, TACC1 and STK19. The progress in melanoma studies allow to receive the positive results in melanoma treatment in particularly with targeted therapy. The molecular targets and future perspectives for targeted therapy of metastatic skin melanoma are discussed.Меланома – наиболее опасное злокачественное заболевание кожи человека с высоким риском метастазирования. Метастазирующая меланома прогностически крайне неблагоприятна и резистентна ко всем видам традиционной химиотерапии и биологическим препаратам. В последнее время достигнуты значительные успехи в понимании патогенеза и лечении меланомы. В развитие меланомы вовлечены как внешние (ультрафиолетовое облучение), так и внутренние (наследственные генетические) факторы. В 5–14 % случаев меланома кожи является наследственным заболеванием, обусловленным изменениями в генах предрасположенности. Факторами риска развития семейной меланомы являются герминальные мутации в генах регуляции клеточного цикла CDKN2A и CDK4, гене гомеостаза меланоцитов MITF, а также однонуклеотидные полиморфизмы ряда низкопенетрантных генов, в частности гена MC1R. В патогенез меланомы вовлечены онкогены и гены-супрессоры, входящие в состав различных сигнальных каскадов. В 75 % случаев меланомы кожи наблюдается гиперактивация сигнального пути RAS / RAF / MEK / ERK. Важнейшим генетическим событием в меланоме является активация сигнального пути PI3K– AKT– mTOR, причем уровень активации повышается с увеличением стадийности меланомы. Меланома представляет собой генетически и фенотипически гетерогенную группу опухолей. Спектр хромосомных нарушений и активирующих мутаций, формирующих различные молекулярные портреты опухоли, отличается в меланоме различной локализации. В меланоме поверхности кожи доминируют мутации в генах BRAF (50 %), NRAS (20 %), причем мутации NRAS характерны для опухолей на участках кожи, подверженных инсоляции. Активирующие мутации KIT выявляют в 20–30 % случаев меланомы акральной или мукозальной локализации, а также в меланоме, возникшей в результате ультрафиолетового повреждения кожи. В 25 % случаев меланома кожи развивается из предсуществующего невуса, в обзоре обсуждаются молекулярные механизмы малигнизации невусов. Использование полноэкзомного секвенирования меланомы позволило обнаружить новые гены, нарушения в которых связаны с повреждающим действием ультрафиолета: PPP6C, RAC1, SNX31, TACC1 и STK19. Успехи в изучении меланомы привели к положительным результатам в ее лечении, особенно с помощью таргетной терапии. В обзоре рассмотрены молекулярные мишени и перспективы таргетной терапии метастатической меланомы кожи