106 research outputs found

    The determination of glial fibrillary acidic protein for the diagnosis and histogenetic study of central nervous system tumors: a study of 152 cases.

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    Glial fibrillary acidic protein (GFAP) was purified from human spinal cord and cerebral white matter. GFAP was localized by an immuno-peroxidase method in normal adult and fetal human brains, rat brains, and 152 central nervous system (CNS) tumors. GFAP was found in reactive and normal astrocytes, immature cells of fetal brain at the 18th to 21st gestational weeks, and normal rat astrocytes. This GFAP staining was quite specific for glial tumors, including astrocytomas, glioblastomas, astroblastomas, and ependymomas. GFAP-positive cells were also found in oligodendrogliomas and choroid plexus papillomas, and they were interpreted as being astroglial or ependymal differentiations. Stromal cells in cerebellar hemangioblastomas were negative. However, engulfed astrocytes were found at the periphery of such tumors and often adjacent to the proliferate blood vessels. In meningiomas, neurinomas, metastatic carcinomas, pituitary adenomas and other non-glial tumors, GFAP-positive cells were not identified.</p

    Flow conditioning modeling and application to particle method

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    This work comprises the development of a re-circulation boundary condition to simulate the flow around a cylinder using the Moving Particles Simulation (MPS). The recirculation boundary condition consists in the re-injection of the fluid particles that flows out the downstream boundary of the computational domain into the upstream boundary through the application of a periodic boundary condition, and a flow conditioner that comprises a region where the velocities of the fluid particles are gradually adjusted to a uniform flow by suppressing the velocity perturbations. The proposed recirculation boundary condition is applied to simulate the flow around a fixed cylinder and the vortex sheet formation process. The Strouhal Number x Reynolds Number diagram obtained using the MPS method show results close to those present in literature. For the laminar flow, the streamlines of MPS simulations show similarity with experimental results present in literature

    Reconstruções arteriais associadas à ressecção de tumores malignos

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    OBJECTIVE: When trunk arteries are affected by malignant neoplasia, and surgical treatment involving tumor and arterial resection is used, the vascular reconstruction must be performed immediately to avoid ischemia in the brain and large tissue masses. The objective of this study was to analyze the results obtained with the treatment of patients with malignant neoplasia who underwent tumor and vascular resection associated with arterial reconstruction. The primary patency of reconstructions, the occurrence arterial complications, and patient survival were assessed. METHODS: Thirty-six patients with cervical, abdominal, or lower limb neoplasias were followed up. These patients underwent elective operations at Hospital do Câncer A.C. Camargo, São Paulo, between September 1997 and September 2004. They were divided into 3 groups according to tumor location: Cervical (14), lower limbs (13), and Abdomen (9). Thirty-eight arterial reconstructions were performed in these 36 patients. RESULTS: There were 5 arterial complications: 2 early- and 3 late-stage. The early complications consisted of 1 symptomatic carotid occlusion with sequelae and 1 femoral graft rupture without sequelae. The late-stage complications consisted of 1 symptomatic carotid occlusion, 1 occlusion of an axillary-carotid graft, and 1 occlusion of a branch of the aortobifemoral graft, all without sequelae. There was no difference between the primary arterial patency rates. All the deaths (22) resulted from progression of neoplasic disease. CONCLUSIONS: Arterial reconstructions associated with resection of malignant neoplasia in cervical, abdominal, or lower limbs can be carried out with low rates of morbidity and mortality. There was no difference in the primary arterial patency rates among the groups studied.OBJETIVO: Quando há acometimento de artérias tronculares por neoplasias malignas e o tratamento cirúrgico é empregado para realização de ressecções tumoral e arterial, a reconstrução vascular deve ser imediata, para evitar a isquemia de tecidos nobres. O objetivo desse trabalho é analisar os resultados do tratamento de pacientes portadores de neoplasias malignas submetidos a ressecções tumoral e vascular associada à reconstrução arterial, avaliando a perviedade primária das reconstruções, as complicações arteriais e a sobrevida dos pacientes. MÉTODOS: Foram acompanhados 36 pacientes com neoplasias em regiões cervical, abdominal ou extremidades inferiores, operados eletivamente no período de setembro de 1997 a setembro de 2004 no Hospital do Câncer A.C.Camargo em São Paulo. Os pacientes foram divididos em três grupos de acordo com a localização das neoplasias: Cervical (14), Extremidade (13) e Abdome (9). Foram realizadas 38 reconstruções arteriais nos 36 pacientes. RESULTADOS: Houve cinco complicações arteriais, sendo duas precoces e três tardias. Entre as precoces, houve uma oclusão carotídea sintomática com seqüelas e uma rotura de enxerto femoral sem seqüelas. Entre as tardias, houve uma oclusão carotídea sintomática, uma oclusão de enxerto carotídeo-axilar e uma oclusão de ramo de enxerto aorto-bifemoral, todas sem sequelas. Não houve diferença entre os índices de perviedade arterial primária . Todos os óbitos (22) ocorreram devido à evolução da doença neoplásica. CONCLUSÕES: As reconstruções arteriais associadas à ressecção de neoplasias malignas em segmentos cervical, abdominal ou extremidades inferiores podem ser realizadas com baixos índices de morbi-mortalidade. Não houve diferença entre os índices de perviedade primária das reconstruções

    Low phase noise THz generation from a fiber-referenced Kerr microresonator soliton comb

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    THz oscillators generated via frequency-multiplication of microwaves are facing difficulty in achieving low phase noise. Photonics-based techniques, in which optical two tones are translated to a THz wave through opto-electronic conversion, are promising if the relative phase noise between the two tones is well suppressed. Here, a THz (≈560 GHz) wave with a low phase noise is provided by a frequency-stabilized, dissipative Kerr microresonator soliton comb. The repetition frequency of the comb is stabilized to a long fiber in a two-wavelength delayed self-heterodyne interferometer, significantly reducing the phase noise of the THz wave. A measurement technique to characterize the phase noise of the THz wave beyond the limit of a frequency-multiplied microwave is also demonstrated, showing the superior phase noise of the THz wave to any other photonic THz oscillators (>300 GHz)

    Low phase noise THz generation from a fiber-referenced Kerr microresonator soliton comb

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    THz oscillators generated via frequency-multiplication of microwaves are facing difficulty in achieving low phase noise. Photonics-based techniques, in which optical two tones are translated to a THz wave through opto-electronic conversion, are promising if the relative phase noise between the two tones is well suppressed. Here, a THz (\approx 560 GHz) wave with an unprecedented phase noise is provided by a frequency-stabilized, dissipative Kerr microresonator soliton comb. The repetition frequency of the comb is stabilized to a long fiber in a two-wavelength delayed self-heterodyne interferometer, significantly reducing the phase noise of the THz wave. A new measurement technique to characterize the phase noise of the THz wave beyond the limit of a frequency-multiplied microwave is also demonstrated, showing the superior phase noise of the THz wave to any other THz oscillators (> 300 GHz)

    Terahertz wireless communication at 560-GHz band using Kerr micro-resonator soliton comb

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    Terahertz (THz) waves have attracted attention as carrier waves for next-generation wireless communications (6G). Electronic THz emitters are widely used in current mobile communications; however, they may face technical limitations in 6G with upper-frequency limits. We demonstrate wireless communication in a 560-GHz band by using a photonic THz emitter based on photomixing of a 560-GHz-spacing soliton microcomb in a uni-travelling carrier photodiode together with a THz receiver of Schottky barrier diode. The on-off keying data transfer with 2-Gbit/s achieves a Q-factor of 3.4, thus, satisfying the limit of forward error correction.Comment: 17 pages, 4 figur

    ERRγ agonist under mechanical stretching manifests hypertrophic cardiomyopathy phenotypes of engineered cardiac tissue through maturation

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    iPS細胞から成熟した人工心筋組織の作製方法の開発 肥大型心筋症の治療法開発への利用に期待. 京都大学プレスリリース. 2023-10-06.Stretching and stimulating engineered heart tissues to accurately portray hypertrophic cardiomyopathy. 京都大学プレスリリース. 2023-10-17.Engineered cardiac tissue (ECT) using human induced pluripotent stem cell-derived cardiomyocytes is a promising tool for modeling heart disease. However, tissue immaturity makes robust disease modeling difficult. Here, we established a method for modeling hypertrophic cardiomyopathy (HCM) malignant (MYH7 R719Q) and nonmalignant (MYBPC3 G115∗) pathogenic sarcomere gene mutations by accelerating ECT maturation using an ERRγ agonist, T112, and mechanical stretching. ECTs treated with T112 under 10% elongation stimulation exhibited more organized and mature characteristics. Whereas matured ECTs with the MYH7 R719Q mutation showed broad HCM phenotypes, including hypertrophy, hypercontraction, diastolic dysfunction, myofibril misalignment, fibrotic change, and glycolytic activation, matured MYBPC3 G115∗ ECTs displayed limited phenotypes, which were primarily observed only under our new maturation protocol (i.e., hypertrophy). Altogether, ERRγ activation combined with mechanical stimulation enhanced ECT maturation, leading to a more accurate manifestation of HCM phenotypes, including non-cardiomyocyte activation, consistent with clinical observations
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