A numerical analysis of formation of the surface relief: A single inclusion model

The influence of the material inhomogeneity on free surface roughening under uniaxial loading is simulated numerically in the framework of the mechanics of heterogeneous media, using a model of a single cubic inclusion embedded in a matrix as an example. Mechanical problems in 2D and 3D formulations are solved numerically by the finite-difference and finite-element methods. The stress-strain state responsible for the free surface roughening is examined. The effects of the inclusion orientation and location relative to the free surface and inclusion-to-matrix elastic modulus ratio on the surface relief characteristics are discussed

Экономика И Демократия: Проблемы Зрелости Демократии Местных Сообществ Сквозь Призму Региональных Пространственных Дисбалансов

The article analyzes the spatial imbalances of municipalities of the Kaluga region in terms of socio-economic development. Subsequently, the estimates obtained were compared with the spatial grouping of regional municipalities in terms of institutional democracy. On the basis of the obtained comparisons, conclusions are made about the impact of socio-economic conditions on the development of grassroots democracy.El artículo analiza los desequilibrios espaciales de los municipios de la región de Kaluga en términos de desarrollo socioeconómico. Posteriormente, las estimaciones obtenidas se compararon con la agrupación espacial de municipios regionales en términos de democracia institucional. Sobre la base de las comparaciones obtenidas, se hacen conclusiones sobre el impacto de las condiciones socioeconómicas en el desarrollo de la democracia de base.В статье проведен анализ пространственных дисбалансов муниципальных образований Калужской области по уровню социально-экономического развития. В дальнейшем полученные оценки были сопоставлены с пространственной группировкой муниципальных образований региона по показателю институциональной демократии. На основе полученных сравнений сделаны выводы о влиянии социально-экономических условий на развитие низовой демократии

Гидродинамическое диспергирование кальций-алюмосиликатных материалов из техногенного и нерудного сырья

Physicochemical properties of two calcium aluminosilicate materials after reducing in the hydrodynamic rotary generator in supercavitation mode were studied. The samples are the crystal ceramic foam based on Kansko-Achinsk lignite-ash and the porous glass material obtained from low-manganese nonmetallic feed. X-ray phase analysis, EPR-method, NPR-method (the Mossbauer Effect) and optical microscopy were used. It was found that the material is changing its stucrure in a hydrodynamic dispersion process caused by high-cavitation. The nature of the changes depends on its initial stateИзучены физико-химические свойства двух кальций-алюмосиликатных материалов после измельчения в гидродинамическом генераторе роторного типа в режиме суперкавитации. Исследованы образцы – кристаллическая пенокерамика на основе зол бурых Канско-Ачинских углей и пористый стекломатериал, полученный из нерудного сырья с низким содержанием марганца. Для анализа были использованы методы РФА, ЭМР, ЯГР (эффект Мёссбауэра), оптическая микроскопия. Показано, что в процессе гидродинамического диспергирования за счет высокоэнергетического кавитационного воздействия в материалах происходят глубокие структурные изменения. Получено, что характер изменений зависит от исходного состояния исследуемого материал

Biomimetic Mineralization of Tooth Enamel Using Nanocrystalline Hydroxyapatite under Various Dental Surface Pretreatment Conditions

In this report, we demonstrated the formation of a biomimetic mineralizing layer obtained on the surface of dental enamel (biotemplate) using bioinspired nanocrystalline carbonate-substituted calcium hydroxyapatite (ncHAp), whose physical and chemical properties are closest to the natural apatite dental matrix, together with a complex of polyfunctional organic and polar amino acids. Using a set of structural, spectroscopy, and advanced microscopy techniques, we confirmed the formation of a nanosized ncHAp-based mineralized layer, as well as studying its chemical, substructural, and morphological features by means of various methods for the pretreatment of dental enamel. The pretreatment of a biotemplate in an alkaline solution of Ca(OH)2 and an amino acid booster, together with the executed subsequent mineralization with ncHAp, led to the formation of a mineralized layer with homogeneous micromorphology and the preferential orientation of the ncHAp nanocrystals. It was shown that the homogeneous crystallization of hydroxyapatite on the biotemplate surface and binding of individual nanocrystals and agglomerates into a single complex by an amino acid booster resulted in an increase (~15%) in the nanohardness value in the enamel rods area, compared to that of healthy natural enamel. Obtaining a similar hierarchy and cleavage characteristics as natural enamel in the mineralized layer, taking into account the micromorphological features of dental tissue, is an urgent problem for future research

Melanoma arising in a Giant congenital melanocytic nevus: two case reports

Abstract Background A giant congenital melanocytic nevus (GCMN) is found in 0.1% of live-born infants. If present, the lesion has a chance of about 6% to develop into malignant melanoma. Both children and adults can be affected by malignant melanoma arising in a giant congenital nevus. Up to 95% of GCMNs harbor NRAS mutations, and mutations in the BRAF, MC1R, TP53, and GNAQ genes have also been described. The individualization of therapy is required, but diagnostic and prognostic criteria remain controversial. Case presentations We report two cases: 1) melanoma arising in a giant congenital nevus during the first month of life complicated with neurocutaneous melanosis (NCM), and 2) melanoma arising in a giant congenital nevus during the first 6 months of life. Pathology, immunohistochemistry, and genetic analyses of tumor tissue were performed. The first case revealed only a non-pathogenic P72R polymorphism of the TP53 gene in the homozygote condition. For the second case, a Q61K mutation was detected in the NRAS gene. Conclusion Malignant melanoma associated with GCMN is rare and therefore poorly understood. Outcomes have been linked to the stage at diagnosis, but no additional pathological prognostic factors have been identified. The most frequent genetic event in giant CMNs is NRAS mutations, which was discovered in one of our cases. To accumulate evidence to improve disease prognosis and outcomes, children with congenital melanocytic nevus should be included in a systemic follow-up study from birth

Гидродинамическое диспергирование кальций-алюмосиликатных материалов из техногенного и нерудного сырья

Physicochemical properties of two calcium aluminosilicate materials after reducing in the hydrodynamic rotary generator in supercavitation mode were studied. The samples are the crystal ceramic foam based on Kansko-Achinsk lignite-ash and the porous glass material obtained from low-manganese nonmetallic feed. X-ray phase analysis, EPR-method, NPR-method (the Mossbauer Effect) and optical microscopy were used. It was found that the material is changing its stucrure in a hydrodynamic dispersion process caused by high-cavitation. The nature of the changes depends on its initial stateИзучены физико-химические свойства двух кальций-алюмосиликатных материалов после измельчения в гидродинамическом генераторе роторного типа в режиме суперкавитации. Исследованы образцы – кристаллическая пенокерамика на основе зол бурых Канско-Ачинских углей и пористый стекломатериал, полученный из нерудного сырья с низким содержанием марганца. Для анализа были использованы методы РФА, ЭМР, ЯГР (эффект Мёссбауэра), оптическая микроскопия. Показано, что в процессе гидродинамического диспергирования за счет высокоэнергетического кавитационного воздействия в материалах происходят глубокие структурные изменения. Получено, что характер изменений зависит от исходного состояния исследуемого материал