444 research outputs found

    Angular extents and trajectory slopes in the theory of holomorphic semigroups in the unit disk

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    We study relationships between the asymptotic behaviour of a non-elliptic semigroup of holomorphic self-maps of the unit disk and the geometry of its planar domain (the image of the Koenigs function). We establish a sufficient condition for the trajectories of the semigroup to converge to its Denjoy-Wolff point with a definite slope. We obtain as a corollary two previously known sufficient conditions

    Innovative development of Russian coastal regions: North–south divergence

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    Coastal regions are territorial social systems whose socio-economic and innovative development is strongly influenced by the factor of coastalisation. The effect of movement to the sea determines the dynamics of settlement systems as well as their economic and infrastructure development. This holds for transport, logistics, information and communications, industrial, and other infrastructure. Coastal regions are so diverse that it is impossible to construct a development model that will fit all of them. One can speak only of general trends. This study focuses on identifying differences between the innovation systems of northern and southern coastal regions within the same country. The geographical scope of the study is four Russian coastal territories: Murmansk and Arkhangelsk in the Baltic Sea region and Rostov and Krasnodar in the Azov-Black Sea region. Methodologically, this study carries out a comparative assessment of heterogeneity of innovative development at municipal and interregional levels, using four groups of indicators: human capital, economic growth and clustering, innovation and digitalisation, and quality and standards of living. All these components are vital for regional innovative development. A statistical assessment is supplemented by a qualitative analysis of spatial patterns of innovation capital accumulation; the agglomeration factor is taken into account. It is shown that northern and southern coastal regions perform very differently on innovative development, the latter doing better than the former. Three main models of innovation generation, implementation, and accumulation of coastal regions are described. Each is associated with a different way to benefit from proximity to the sea. These are maritime activities, maritime transport, and the economic use of recreational, natural and climatic resources

    Premorphological alterations in gastric mucosa in patients with gastric cancer: hypoxia level assessed by 31P NMR spectroscopy

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    The aim of this study was to detect the hypoxic status in adjacent histologically uninvolved gastric mucosa in gastric cancer (GC) patients. Patients and Methods: 50 naïve patients with primary GC, and one patient with stomach ulcer (gastric mucosa was used as control) were enrolled into the study. The tumor and mucosa samples of stomach (without muscularis and serosa layers) in patients with GC were obtained immediately after operation. Assessment of the hypoxia level has been provided using 31P NMR spectroscopy in tissue perchloric acid extracts. Mucosa was examined by convenient histological method. Obtained results were analyzed statistically. Results: It was shown that gastric mucosa in 52% of patients with GC is under different levels of hypoxia, among them 23% of mucosa is under severe hypoxia (PME/Pi < 1.0) with average mean of PME/Pi 0.89 ± 0.04. It was revealed that there are definite associations between the hypoxia in mucosa tissue and pT as well as pN categories and G grade and stage of disease but not with M category. Overall survival of patients with gastric mucosa characterized by severe and mild hypoxia was significantly poorer as compared to that of patients with gastric mucosa with satisfactory oxygenation (p = 0.0035). Conclusion: Gastric mucosa uninvolved in tumor process is characterized by hypoxia in 52% of GC patients; severe hypoxia of mucosa was detected in 23% of patients having hypoxic mucosa. It was suggested that biochemical alterations in tissue surrounding tumor node may precede morphological ones. Key Words: gastric cancer, mucosa, hypoxia
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