ВЗАИМОСВЯЗЬ ИНДИВИДУАЛЬНО-ЛИЧНОСТНЫХ ОСОБЕННОСТЕЙ С ПОКАЗАТЕЛЯМИ ПО ШКАЛАМ БЕКА У ПОДРОСТКОВ С СУИЦИДАЛЬНЫМИ МЫСЛЯМИ

В статье представлены результаты исследования взаимосвязи личностных особенностей с показателями по депрессии, тревоге и безнадежности у подростков с суицидальными мыслями. Цель исследования состояла в определении индивидуально-личностных характеристик, наиболее присущих подросткам с суицидальными мыслями, а также взаимосвязи данных характеристик с показателями тревоги, депрессии, безнадежности и суицидальных мыслей по шкалам Бека. Посредством корреляционного анализа было выявлено, что к суицидальным мыслям больше склонны подростки с высокими показателями по таким шкалам, как ригидность, индивидуализм и интроверсия. Исследование проводилось на базе Центра психотерапии С. Скляра путем опроса подростков, обратившихся в Центр с жалобами на наличие суицидальных мыслей. Индивидуально-личностные особенности определялись с помощью «Стандартизированного многофакторного метода исследования личности» (СМИЛ). В исследовании была выявлена взаимосвязь показателей шкал СМИЛа с показателями по шкалам тревоги, депрессии, безнадежности и суицидальных мыслей А. Бека. Ценность и значимость исследования заключается в том, что по его результатам возможно составление плана профилактических мероприятий по превенции суицидального поведения среди подростков, а также для определения мишеней индивидуальной психотерапии подростков, находящихся в группе риска. Ключевые слова: подростки, подростковый суицид, личностные особенности, шкалы А. Бека

Heteroepitaxial Growth Of Colloidal Nanocrystals Onto Substrate Films Via Hot-injection Routes

Hot-injection synthesis of colloidal nanocrystals (NCs) in a substrate-bound form is demonstrated. We show that polycrystalline films submerged into hot organic solvents can nucleate the heteroepitaxial growth of semiconductor NCs, for which the ensuing lattice quality and size distribution are on the par with those of isolated colloidal nanoparticles. This strategy is demonstrated by growing lead chalcogenide NCs directly onto solvent-submerged TiO(2) substrates. The resulting PbX/VTiO(2) (X = S, Se, Te) nanocomposites exhibit heteroepitaxial interfaces between lead chalcogenide and oxide domains and show an efficient separation of photoinduced charges, deployable for light-harvesting applications. The extendibility of the present method to other material systems was demonstrated through the synthesis of CdS/TiO(2) and Cu(2)S/TiO(2) heterostructures, fabricated from PbS/TiO(2) composites via cation exchange. The photovoltaic performance of nanocrystal/substrate composites comprising PbS NCs was evaluated by incorporating PbS/TiO2 films Into prototype solar cells

Improving The Catalytic Activity Of Semiconductor Nanocrystals Through Selective Domain Etching

Colloidal chemistry offers an assortment of synthetic tools for tuning the shape of semiconductor nanocrystals. While many nanocrystal architectures can be obtained directly via colloidal growth, other nanoparticle morphologies require alternative processing strategies. Here, we show that chemical etching of colloidal nanoparticles can facilitate the realization of nanocrystal shapes that are topologically inaccessible by hot-injection techniques alone. The present methodology is demonstrated by synthesizing a two-component CdSe/CdS nanoparticle dimer, constructed in a way that both CdSe and CdS semiconductor domains are exposed to the external environment. This structural morphology is highly desirable for catalytic applications as it enables both reductive and oxidative reactions to occur simultaneously on dissimilar nanoparticle surfaces. Hydrogen production tests confirmed the improved catalytic activity of CdSe/CdS dimers, which was enhanced 3-4 times upon etching treatment. We expect that the demonstrated application of etching to shaping of colloidal heteronanocrystals can become a common methodology in the synthesis of charge-separating nanocrystals, leading to advanced nanoparticles architectures for applications in areas of photocatalysis, photovoltaics, and light detection

Photocatalytic Activity Of Core/shell Semiconductor Nanocrystals Featuring Spatial Separation Of Charges

The present study investigates the photocatalytic activity of ZnSe/CdS core/shell semiconductor nanocrystals. These nanoparticles exhibit a spatial separation of photoinduced charges between the core and the shell domains, which makes them potentially viable for photocatalytic applications. Unfortunately, one of the excited charges remains inside the core semiconductor and thus cannot efficiently react with the external environment. Here, we explore this issue by investigating the mechanisms of hole extraction from the ZnSe core to the surface of the CdS shell. In particular, the effect of shell thickness in ZnSe/CdS core/shell nanocrystals on the ability of core-localized charges to perform oxidative reactions was determined. By using a combination of time-resolved spectroscopy and electrochemical techniques, we demonstrate that the use of hole-scavenging surfactants facilitates an efficient transfer of core-localized holes to the surface even in the case of shells exceeding 7 nm in thickness. These measurements further demonstrate that photoinduced holes can be extracted from the core faster than they recombine with shell-localized electrons, indicating that most of the absorbed energy in ZnSe/CdS nanocrystals can be used to drive catalytic reactions

Last interglacial temperature evolution – a model inter-comparison

Abstract. There is a growing number of proxy-based reconstructions detailing the climatic changes during the Last Interglacial period. This period is of special interest because large parts of the globe were characterized by a warmer-than-present-day climate, making this period an interesting test bed for climate models in the light of projected global warming. However, mainly because synchronizing the different records is difficult, there is no consensus on a global picture of Last Interglacial temperature changes. Here we present the first model inter-comparison of transient simulations covering the Last Interglacial period. By comparing the different simulations we aim at investigating the robustness of the simulated surface air temperature evolution. The model inter-comparison shows a robust Northern Hemisphere July temperature evolution characterized by a maximum between 130–122 ka BP with temperatures 0.4 to 6.8 K above pre-industrial values. This temperature evolution is in line with the changes in June insolation and greenhouse-gas concentrations. For the evolution of July temperatures in the Southern Hemisphere, the picture emerging from the inter-comparison is less clear. However, it does show that including greenhouse-gas concentration changes is critical. The simulations that include this forcing show an early, 128 ka BP July temperature anomaly maximum of 0.5 to 2.6 K. The robustness of simulated January temperatures is large in the Southern Hemisphere and the mid-latitudes of the Northern Hemisphere. In these latitudes maximum January temperature anomalies of respectively −2.5 to 2 K and 0 to 2 K are simulated for the period after 118 ka BP. The inter-comparison is inconclusive on the evolution of January temperatures in the high-latitudes of the Northern Hemisphere. Further investigation of regional anomalous patterns and inter-model differences indicate that in specific regions, feedbacks within the climate system are important for the simulated temperature evolution. Firstly in the Arctic region, changes in the summer sea-ice cover control the evolution of Last Interglacial winter temperatures. Secondly, for the Atlantic region, the Southern Ocean and the North Pacific, possible changes in the characteristics of the Atlantic meridional overturning circulation are critical. The third important feedback, having an impact on the temperature evolution of the Northern Hemisphere, is shown to be the presence of remnant continental ice from the preceding glacial period. Another important feedback are changes in the monsoon regime which controls the evolution of temperatures over parts of Africa and India. Finally, the simulations reveal an important land-sea contrast, with temperature changes over the oceans lagging continental temperatures by up to several thousand years. The aforementioned feedback mechanisms tend to be highly model-dependent, indicating that specific proxy-data is needed to constrain future climate simulations and to further enhance our understanding of the evolution of the climate during the Last Interglacial period

Exact Solution of the strong coupling t-V model with twisted boundary conditions

We present the solution of the one-dimensional t-V model with twisted boundary conditions in the strong coupling limit, t<<V and show that this model can be mapped onto the strong coupling Hubbard chain threaded by a fictitious flux proportional to the total momentum of the charge carriers. The high energy eigenstates are characterized by a factorization of degrees of freedom associated with configurations of soliton and antisoliton domains and degrees of freedom associated with the movement of ``holes'' through these domains. The coexistence of solitons and antisolitons leads to a strange flux dependence of the eigenvalues. We illustrate the use of this solution, deriving the full frequency dependence of the optical conductivity at half-filling and zero temperature.Comment: 11 pages, 1 figure; to be published in Physical Review

Finite-Temperature Transport in Finite-Size Hubbard Rings in the Strong-Coupling Limit

We study the current, the curvature of levels, and the finite temperature charge stiffness, D(T,L), in the strongly correlated limit, U>>t, for Hubbard rings of L sites, with U the on-site Coulomb repulsion and t the hopping integral. Our study is done for finite-size systems and any band filling. Up to order t we derive our results following two independent approaches, namely, using the solution provided by the Bethe ansatz and the solution provided by an algebraic method, where the electronic operators are represented in a slave-fermion picture. We find that, in the U=\infty case, the finite-temperature charge stiffness is finite for electronic densities, n, smaller than one. These results are essencially those of spinless fermions in a lattice of size L, apart from small corrections coming from a statistical flux, due to the spin degrees of freedom. Up to order t, the Mott-Hubbard gap is \Delta_{MH}=U-4t, and we find that D(T) is finite for n<1, but is zero at half-filling. This result comes from the effective flux felt by the holon excitations, which, due to the presence of doubly occupied sites, is renormalized to \Phi^{eff}=\phi(N_h-N_d)/(N_d+N_h), and which is zero at half-filling, with N_d and N_h being the number of doubly occupied and empty lattice sites, respectively. Further, for half-filling, the current transported by any eigenstate of the system is zero and, therefore, D(T) is also zero.Comment: 15 pages and 6 figures; accepted for PR

Морфофункциональная характеристика ворсинчатого хориона в ранние сроки беременности при наличии урогенитальной инфекции

The morphological structure of the chorion villi in I trimester of pregnancy is studied at ureaplasmas and mycoplasmas infections. Established signs of the accelerated maturing of the villi, strengthened proliferation of trophoblast, increased of stromal and vascular components of chorion have been revealed.Изучено морфологическое строение ворсинчатого хориона в первом триместре беременности при уреа- и микоплазменном инфицировании. Были выявлены признаки ускоренного созревания ворсинчатого дерева, проявляющиеся усиленной пролиферацией трофобластического эпителия, приростом стромального и сосудистого компонентов ворсин