检索结果-南通市图书馆

Pigmented Villonodular Synovitis of the Spine: Two Case Reports and a Literature Review

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Orthopedics 2025年第1期15卷 31-40页

作者： Kazumasa Nakamura Hiroshi Takahashi Katsunori Fukutake keiji Hasegawa Akihito Wada Department of Orthopedic Surgery School of Medicine Toho University Tokyo Japan

Introduction: Pigmented villonodular synovitis (PVNS) of the spine is a rare condition, with only a limited number of cases documented in the medical literature. In this study, we review imaging findings of two cases of PVNS arising in the spine. Case 1: A 52-year-old male presented with right thigh pain of unclear etiology. His condition subsequently deteriorated and he was referred to our hospital. MRI revealed a spinal tumor with high intensity on T1-weighted imaging (T1WI) and iso-intensity on T2WI in the right L2/3 intervertebral foramen. The tumor exhibited heterogeneous enhancement on contrast-enhanced MRI. Computed tomography (CT) myelography showed the presence of an epidural tumor within the right L2/3 intervertebral foramen, situated externally to the spinal canal and compressing the dura mater. Notable scalloping was observed in the posterior margin of the L2 vertebral body on CT images. Case 2: A 78-year-old male presented with a complaint of muscle weakness of the left upper limb. His gait gradually deteriorated, which led to suspicion of cervical myelopathy. A tumor was observed on plain MRI and exhibited low to iso-intensity on T1WI and high intensity on T2WI. The tumor was in the left C7/T1 intervertebral segment and the spinal cord was compressed from the left side. CT showed destruction of the medial aspect of the left C7 vertebral arch. Conclusion: In spinal PVNS, the signal intensity on MRI is dependent on the timing of hemorrhage within the tumor, and there are no distinctive features. However, if an extradural tumor is suspected and CT shows bone erosion, scalloping or osteolytic changes, PVNS should be considered as a differential diagnosis.

关键词： Spinal Pigmented Villonodular Synovitis Imaging Diagnosis Computed Tomography Magnetic Resonance Imaging

Bounded derived categories of very simple manifolds

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2011年第8期54卷 1741-1750页

作者： OGUISO keiji Department of Mathematics Graduate School of ScienceOsaka University Korea Institute for Advanced Study

A non-representable cohomological functor of finite type of the bounded derived category of coherent sheaves of a compact complex manifold of dimension greater than one with no proper closed subvariety is given explic... 详细信息

关键词： derived category cohomological functor very simple manifold

A simple remark on a flat projective morphism with a Calabi-Yau fiber

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2011年第8期54卷 1751-1756页

作者： OGUISO keiji Department of Mathematics Graduate School of ScienceOsaka University Korea Institute for Advanced Study

If a K3 surface is a fiber of a flat projective morphisms over a connected noetherian scheme over the complex number field,then any smooth connected fiber is also a K3 *** this,Professor Nam-Hoon Lee asked if the same is true for higher dimensional Calabi-Yau *** shall give an explicit negative answer to his question in each dimension greater than or equal to three as well as a proof of his initial observation.

关键词： flat projective morphism Hilbert scheme Calabi-Yau manifold

Circuit Implementation of Power Converter for High-Speed Switching Operations

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electrical Engineering 2018年第3期4卷 47-52页

作者： keiji Wada Department of Electronics Engineering and Computer Science Tokyo Metropolitan UniversityTokyo Japan

Recently,high di/dt and dv/dt switching operations of power converter circuits has been discussed for realizing a high-efficiency power converter *** this case,parasitic inductances of the bus bar between a DC capacitor and power devices may cause issues of overshoot voltage and electromagnetic interference(EMI)***,it is necessary to design the bus bar geometry while considering the minimization and optimization of the parasitic inductance of bus *** paper discusses a relationship between bus bar geometry and switching *** addition,the bus bar analysis is based on the PEEC method,and the bus bar geometry is designed by considering the stray inductance with using an inductance-map ***,this paper also presents a design procedure of acceptable stray inductance based on a standardization *** should be noted that the stray inductance is designed not for minimization,but optimization,and it is shown not as an absolute value(H),but as a percentage value(%).Finally,the oscillation waveforms under turn-off operation will be discussed depending on the bus bar geometry.

关键词： Bus bar inductance bus bar geometry circuit implementation EMI switching characteristics

Krein Parameters of Fiber-Commutative Coherent Configurations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Algebra Colloquium 2020年第1期27卷 1-10页

作者： keiji Ito Akihiro Munemasa Research Center for Pure and Applied Mathematics Graduate School of Information SciencesTohoku UniversitySendaiJapan

For fiber-commutative coherent configurations,we show that Krein parameters can be defined essentially *** a consequence,the general Krein condition reduces to positive semidefiniteness of finitely many matrices determined by the parameters of a coherent *** mention its implications in the coherent configuration defined by a generalized *** also simplify the absolute bound using the matrices of Krein parameters.

关键词： coherent configuration association scheme Krein parameter Krein condition generalized quadrangle absolute bound

Type 17 immunity:novel insights into intestinal homeostasis and autoimmune pathogenesis driven by gut-primed T cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2024年第11期21卷 1183-1200页

作者： Daiya Ohara Yusuke Takeuchi keiji Hirota Laboratory of Integrative Biological Science Institute for Life and Medical SciencesKyoto UniversityKyotoJapan ImmunoSensation Cluster of Excellence University of BonnBonnGermany

The IL-23 signaling pathway in both innate and adaptive immune cells is vital for orchestrating type 17 immunity,which is marked by the secretion of signature cytokines such as IL-17,IL-22,and *** proinflammatory mediators play indispensable roles in maintaining intestinal immune equilibrium and mucosal host defense;however,their involvement has also been implicated in the pathogenesis of chronic inflammatory disorders,such as inflammatory bowel diseases and ***,the implications of type 17 immunity across diverse inflammation models are *** review provides a comprehensive overview of the multifaceted roles of these cytokines in maintaining gut homeostasis and in perturbing gut barrier integrity,leading to acute and chronic inflammation in various models of gut infection and ***,this review focuses on type 17 immunity interconnecting multiple organs in autoimmune conditions,with a particular emphasis on the pathogenesis of autoimmune arthritis and neuroinflammation driven by T cells primed within the gut microenvironment.

关键词： IL-23 Th17 cDCIL-23 Inflammatory bowel diseases(IBD) Gut-joint axis Gut-brain axis

STUDY ON THE CHARACTERISTICS OF LONG TERM DISCHARGE OF A CATCHMENT

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2000年第2期12卷 31-41页

作者： Hong, Lin Takase, keiji Sato, Koichi Wuhan Univ of Hydraulic and Electric Engineering Wuhan China

The characteristics of the catchment discharge vary with land use. The characteristics of the long-term discharge of a terraced paddy field catchment were studied. Two kind of tank models for land use were proposed and used to simulate the discharge of the catchment: one is a forest type model used as the upper part of the catchment; the other is a paddy field type model used as the lower part of the catchment. The results of the model simulation were analyzed and compared with that of a forest catchment.

关键词： Discharge (fluid mechanics) Land use Models Tanks (containers)

MICROSCOPIC HETEROGENEITY IN VISCOELASTIC PROPERTIES OF MOLECULAR ASSEMBLED SYSTEMS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2013年第1期31卷 1-1,2-11页

作者： Atsuomi Shundo David P. Penaloza keiji Tanaka Department of Applied Chemistry Kyushu University International Institute for Carbon-Neutral Energy Research (WPI-I2CNER) Kyushu University

An important step in understanding molecular assembled systems is to examine the structure and physical properties at various length scales and clarify the correlation between them. However, while the structures of these systems have been extensively studied from nanoscopic to macroscopic scales, their viscoelastic properties have been often limited to bulk rheological measurements. By using optical tweezers and particle tracking, we here show the local viscoelastic properties and their spatial distributions for the following systems： worm-like micelle solution, supramolecular hydrogel and lyotropic liquid crystal, which are formed by self-assembly of amphiphilic molecules in water. We found that all systems studied possessed a spatial heterogeneity in their viscoelastic properties and this was originated from the heterogeneous structures. It is interesting to note that there is the heterogeneity with the characteristic length scale of sub-micrometer or micrometer scale, thereby structures, although the systems are formed by molecules with nanometer size. The findings of these studies should lead to a better understanding of the dynamics of such systems.

关键词： Optical tweezers Soft materials Heterogeneity Hierarchical structure Rheological properties.

Effect of mechanical ball milling on the electrical and powder bed properties of gas-atomized Ti-48Al-2Cr-2Nb and elucidation of the smoke mechanism in the powder bed fusion electron b eam melting process

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第6期137卷 36-55页

作者： Seungkyun Yim Kenta Aoyagi keiji Yanagihara Huakang Bian Akihiko Chiba Institute for Materials Research Tohoku University2-1-1 KatahiraSendaiMiyagi 980-8577Japan

Smoke is unexpected powder-splashing caused by electrostatic force and is one of the main problems hindering the process stability and applicability of the powder bed fusion electron beam(PBF-EB)*** this study,mechanical stimulation was suggested to suppress smoke of gas-atomized(GA)Ti-48Al-2Cr-2Nb powder using Al_(2)O_(3) and WC ball *** deformation mechanism of the GA powder depending on the ball milling media was discussed based on the developed particle morphology distribu-tion map and contact mechanics *** was revealed that the rapid decrement of flowability and packing density after WC ball milling owing to the formation of angular fragments by the brittle *** variation of surface and electrical properties by mechanical stimulation was investigated via XPS,TEM,and Impedance *** electrical resistivity of the ball-milled powders gradually decreased with increasing milling duration,despite the increased oxide film thickness,and the capacitive response disappeared in Al-60 and WC-30 via metal-insulator *** could be due to the accumulation of strain and defects on the oxide film via mechanical *** smoke mechanism of ball-milled powders was discussed based on the percolation *** the smoke experiment,smoke was more suppressed for WC-10 and WC-20 than that for Al-40 and Al-50,respectively,despite the longer charge dissipation *** could be due to the high probability of contact with conductive *** the Al-60 and WC-30 powders,smoke was further restricted by the formation of a percolation cluster with metal-like electrical *** believe that this study will contribute to a better understanding of the smoke mechanism and process optimization of the PBF-EB.

关键词： Metal-insulator transition Electron beam melting additive manufacturing Packing density Flowability Smoke mechanism Percolation theory