803 research outputs found
Finite surgeries on three-tangle pretzel knots
We classify Dehn surgeries on (p,q,r) pretzel knots that result in a manifold
of finite fundamental group. The only hyperbolic pretzel knots that admit
non-trivial finite surgeries are (-2,3,7) and (-2,3,9). Agol and Lackenby's
6-theorem reduces the argument to knots with small indices p,q,r. We treat
these using the Culler-Shalen norm of the SL(2,C)-character variety. In
particular, we introduce new techniques for demonstrating that boundary slopes
are detected by the character variety.Comment: 18 pages, 15 figures v2 - minor revisions throughou
Bilateral Pneumothorax Associated With Lung and Pleural Metastases of Breast Cancer
A rare case of bilateral pneumothorax in a 54-year-old woman with advanced breast cancer
associated with lung and pleural metastases is presented. The patient was admitted to our
hospital complaining of unexpected severe dyspnea. A chest X-ray showed bilateral pneumothorax
associated with multiple lung metastases and pleural effusions, followed by
immediate pleural drainage. Although air leak and effusions of the right lung were well
controlled by the conservative management, massive air leaks of the left lung had continued
for 40 days. Because of patient's poor general status a surgical closure of the leaking site
was selected using video-assisted thoracoscopic surgery techniques. Thoracoscopy revealed
a ruptured bulla in the lower lobe (S6), thus, followed by a successful bullectomy with a
stapling device. We speculate that multiple pleural metastasis may disturb the normal
repair mechanism of the lung tissue and cause prolonged persistent air leaks
Changes of Commercial Location in Local Middle-sized Cities : Cases about the Cities of the Western Kyushu Region
近年,多くの地方都市において人口が減少するなか,小売商業の郊外化は進展し続けた。中心市街地の衰退が進むなか,国レベルの法の改正や自治体レベルの政策において,人口減少社会に対応した「まち」のあり方が求められるようになった。本研究では,小売業の郊外化が進展し,中心市街地の再生が大きな課題となる地方の中規模都市を対象として,全国レベルの商業立地の動向を検証したうえで,西九州の佐世保市,佐賀市,長崎市の事例を詳細に考察した。そして都市がおかれている環境,自治体レベルの政策・まちづくりの方針などの相違を含めながら,商業立地の方向性に関する個々の地方中規模都市の現状と課題を考察した。Many local cities in Japan have experienced population decrease for recent decades, but the suburbanization of the retail activities of these cities has not ended. As the result the city center degeneration has become one of the most serious problems for many cities and the center city revitalization became the most important task to solve. In this paper the author analyzed the commercial location for the middle-sized city in Japan and concretely analyzed the three cities in the western Kyushu (Sasebo, Saga and Nagasaki). In this case studies the author examined current urban environment and the land use and commercial development policies. After the consideration of the current situations and problems, the future tasks are examined for the middle-sized cities facing the city center revitalization.伊東理教授退職記念号特集 : 都市空間の地理
Influence of dislocations in transition metal oxides on selected physical and chemical properties
Studies on dislocations in prototypic binary and ternary oxides (here TiO2 and SrTiO3) using modern TEM and scanning probe microscopy (SPM) techniques, combined with classical etch pits methods, are reviewed. Our review focuses on the important role of dislocations in the insulator-to-metal transition and for redox processes, which can be preferentially induced along dislocations using chemical and electrical gradients. It is surprising that, independently of the growth techniques, the density of dislocations in the surface layers of both prototypical oxides is high (109/cm2 for epipolished surfaces and up to 1012/cm2 for the rough surface). The TEM and locally-conducting atomic force microscopy (LCAFM) measurements show that the dislocations create a network with the character of a hierarchical tree. The distribution of the dislocations in the plane of the surface is, in principle, inhomogeneous, namely a strong tendency for the bundling and creation of arrays or bands in the crystallographic and directions can be observed. The analysis of the core of dislocations using scanning transmission electron microscopy (STEM) techniques (such as EDX with atomic resolution, electron-energy loss spectroscopy (EELS)) shows unequivocally that the core of dislocations possesses a different crystallographic structure, electronic structure and chemical composition relative to the matrix. Because the Burgers vector of dislocations is per se invariant, the network of dislocations (with additional d1 electrons) causes an electrical short-circuit of the matrix. This behavior is confirmed by LCAFM measurements for the stoichiometric crystals, moreover a similar dominant role of dislocations in channeling of the current after thermal reduction of the crystals or during resistive switching can be observed. In our opinion, the easy transformation of the chemical composition of the surface layers of both model oxides should be associated with the high concentration of extended defects in this region. Another important insight for the analysis of the physical properties in real oxide crystals (matrix + dislocations) comes from the studies of the nucleation of dislocations via in situ STEM indentation, namely that the dislocations can be simply nucleated under mechanical stimulus and can be easily moved at room temperature
GATA2 zinc finger 2 mutation found in acute myeloid leukemia impairs myeloid differentiation
AbstractWe identified two novel GATA2 mutations in acute myeloid leukemia (AML). One mutation (p.R308P-GATA2) was a R308P substitution within the zinc finger (ZF)-1 domain, and the other (p.A350_N351ins8-GATA2) was an eight-amino-acid insertion between A350 and N351 residues within the ZF-2 domain. p.R308P-GATA2 did not affect DNA-binding and transcriptional activities, while p.A350_N351ins8-GATA2 reduced them, and impaired G-CSF-induced granulocytic differentiation of 32D cells. Although p.A350_N351ins8-GATA2 did not show a dominant-negative effect over wild-type (Wt)–GATA2 by the reporter assay, it might be involved in the pathophysiology of AML by impairing myeloid differentiation because of little Wt-GATA2 expression in primary AML cells harboring the p.A350_N351ins8 mutation
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