63 research outputs found

    X-ray Emission and Discharge Behavior on Three Kinds of Stacked Pyroelectric Single Crystal Units

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    タンタル酸リチウム単結晶を積層させたユニットの焦電特性に基づく放電およびX 線発生挙動について,結晶形状および真空度による相違を検討した.大気下での室温~400Kの温度変化サイクルに伴う放電現象はいずれも積層型結晶ユニット側面で観察された.放電回数は同一形状の板状単結晶を使用したユニットの方が形状不揃いの結晶を同一枚数積層させたときより5 倍多く,側面に絶縁グリースを塗布すると大幅に抑制された.放電は積層した板状結晶の間隙で起こり,加熱時には数秒から1 分間の短時間のスパイク状のX線が繰り返し発生した.X線の最高エネルギーは1Paと10-4Paでは相違なかったが,やや1Paの方がスパイク状X線の発生頻度が高かった.スパイク状のX 線発生および放電挙動の要因について議論した.Three types of stacked LiTaO3 single crystal units were assembled to investigate effects of shape of the single crystal and degree of ambient pressure on X-ray emission and discharge behavior based on the pyro electricity. Every instantaneous emission of visible light due to discharge occurred at the side of stacked crystals during heating and cooling cycle between room temperature and 400 K under atmospheric pressure. Discharge frequency on a stacked unit made of equal-sized four pieces (type-A) was five times more than that on a unit made of irregularlysized pieces (type-C). Discharge occurred possibly at narrow gap between two pieces of platelike single crystal. During heating process up to ca. 400 K under 1 or 10 - 4 Pa, spike-like X-ray emission for a few seconds through one minute occurred repeatedly on both type-A and -C units. The maximum energy of emitted X-ray was independent on both degree of vacuum and shape of stacked plate-like LiTaO3 single crystal. Discharge on type-A unit was suppressed by coating of stacked crystals with dielectric grease whereas high voltage generated on the coated unit. Origin of spike-like X-ray emission and discharge on stacked LiTaO3 units was discussed

    A case of eosinophilic chronic rhinosinusitis associated with optic neuropathy

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    We report a case of eosinophilic chronic rhinosinusitis (ECRS) associated with optic neuropathy. The visual acuity in the right eye was suddenly reduced to no light perception on awakening in the morning. Fundus examination of both eyes on the same day showed no remarkable changes. Emergency computed tomography showed pan-sinusitis bilaterally and a partial defect of the sphenoid bone on the right side. From the clinical findings, the case was diagnosed as optic neuropathy associated with chronic sinusitis. Endoscopic sinus surgery (ESS) was performed on the same day, and all of the major sinuses were found to be filled with highly viscous fluid. Part of the optic canal had a defect probably due to inflammatory invasion from the adjacent sphenoid bone. Steroid therapy was started immediately postoperatively. Histopathological examination of excised polyps showed that numerous eosinophils had invaded the polyps but no hyphae were present. The patient reported that he had bronchial asthma and had had nasal polypectomy. Six months after the ESS and steroid therapy, the patient had a recurrence of the sinusitis. At that time, laboratory examination showed an elevation of total IgE and eosinophil numbers. From the clinical findings and course, this case was diagnosed as ECRS accompanied by optic neuropathy. Although ECRS rarely has ocular complications, the inflammation can spread and the optic nerve can be affected

    Pembelajaran Berbasis Projek dengan Pendekatan Jelajah Alam Sekitar sebagai Model Perkuliahan Fisiologi Hewan

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    Penelitian ini dilakukan dengan tujuan untuk menguji efektivitas penerapan model pembelajaran berbasis projek (Project Based Learning/PBL) dengan pendekatan Jelajah Alam Sekitar (JAS) pada perkuliahan Fisiologi Hewan bagi mahasiswa Program Studi Pendidikan Biologi. Penelitian ini merupakan quasi eksperimen dengan desain one shot case study. Populasi dalam penelitian ini adalah mahasiswa Program Studi Pendidikan Biologi dan sebagai sampel adalah mahasiswa semester 4 Prodi Pendidikan Biologi rombel 1,2,dan 3 tahun ajaran 2010 / 2011 yang mengambil mata kuliah Fisiologi Hewan. Pengambilan sampel dengan teknik purposive random sampling. Sebagai variabel bebas adalah penerapan model PBL dengan pendekatan JAS, sedangkan sebagai variabel terikat adalah efektivitas model pembelajaran yang diterapkan dilihat dari hasil belajar, aktivitas siswa dan keterlaksanaan kegiatan yang diprogramkan. Sumber data penelitian adalah mahasiswa. Data yang diambil adalah nilai ujian tulis, nilai laporan, nilai presentasi , aktivitas mahasiswa serta tanggapan keterlaksanaan PBL dengan pendekatan JAS. Hasil penelitian menunjukkan bahwa penerapan model PBL dengan pendekatan JAS telah dapat mencapai indikator-indikator yang ditetapkan yaitu mahasiswa yang memperoleh nilai minimal B mencapai 70%, tanpa nilai D dan E, mahasiswa dengan kriteria keaktifan pada kategori tinggi dan sangat tinggi mencapai minimal 80%, dan tingkat keterlaksanaan kegiatan dalam pembelajaran berbasis projek dengan pendekatan JAS mencapai 80%. Simpulan yang dapat diambil dari penelitian ini adalah model pembelajaran berbasis projek dengan pendekatan JAS pada perkuliahan Fisiologi Hewan efektif diterapkan

    Orbital apex syndrome associated with herpes zoster ophthalmicus

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    We report our findings for a patient with orbital apex syndrome associated with herpes zoster ophthalmicus. Our patient was initially admitted to a neighborhood hospital because of nausea and loss of appetite of 10 days’ duration. The day after hospitalization, she developed skin vesicles along the first division of the trigeminal nerve, with severe lid swelling and conjunctival injection. On suspicion of meningoencephalitis caused by varicella zoster virus, antiviral therapy with vidarabine and betamethasone was started. Seventeen days later, complete ptosis and ophthalmoplegia developed in the right eye. The light reflex in the right eye was absent and anisocoria was present, with the right pupil larger than the left. Fat-suppressed enhanced T1-weighted magnetic resonance images showed high intensity areas in the muscle cone, cavernous sinus, and orbital optic nerve sheath. Our patient was diagnosed with orbital apex syndrome, and because of skin vesicles in the first division of the trigeminal nerve, the orbital apex syndrome was considered to be caused by herpes zoster ophthalmicus. After the patient was transferred to our hospital, prednisolone 60 mg and vidarabine antiviral therapy was started, and fever and headaches disappeared five days later. The ophthalmoplegia and optic neuritis, but not the anisocoria, gradually resolved during tapering of oral therapy. From the clinical findings and course, the cause of the orbital apex syndrome was most likely invasion of the orbital apex and cavernous sinus by the herpes virus through the trigeminal nerve ganglia

    Proteomic Study of Retinal Proteins Associated with Transcorneal Electric Stimulation in Rats

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    Background. To investigate how transcorneal electric stimulation (TES) affects the retina, by identifying those proteins up- and downregulated by transcorneal electric stimulation (TES) in the retina of rats. Methods. Adult Wistar rats received TES on the left eyes at different electrical currents while the right eyes received no treatment and served as controls. After TES, the eye was enucleated and the retina was isolated. The retinas were analyzed by proteomics. Results. Proteomics showed that twenty-five proteins were upregulated by TES. The identified proteins included cellular signaling proteins, proteins associated with neuronal transmission, metabolic proteins, immunological factors, and structural proteins. Conclusions. TES induced changes in expression of various functional proteins in the retina

    Optic Neuritis Possibly Induced by Anti-PD-L1 Antibody Treatment in a Patient with Non-Small Cell Lung Carcinoma

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    Background: Recent immune therapy with checkpoint inhibitors (CPIs) has demonstrated remarkable antitumor effects on specific tumors, such as malignant lymphoma and non-small cell lung carcinoma. By contrast, CPIs cause an imbalance in the immune system, triggering a wide range of immunological side effects termed immune-related adverse effects (irAEs). Here, we report a rare case of optic neuritis and hypopituitarism during anti-programmed death-ligand 1 (PD-L1) antibody treatment. Case Presentation: A patient with non-small cell lung carcinoma received anti-PD-L1 antibody treatment every 3 weeks; however, the patient started experiencing headaches, general fatigue, anorexia, and diarrhea approximately 1 year after the initiation of the treatment. Moreover, sudden visual loss of the right eye occurred 1 week after the interruption of the anti-PD-L1 antibody treatment. MRI findings showed gadolinium enhancement in the left optic nerve, but no enlargement of the pituitary gland and stalk. Laboratory data showed decreased serum adrenocorticotropic hormone (ACTH), cortisol, and free T4 levels, and a hormone tolerance test indicated hypopituitarism, hypothyroidism, and hypoadrenocorticism. The central scotoma caused by optic neuritis completely disappeared immediately after a course of steroid pulse therapy, and no recurrence occurred up to 2 years after initiation of the steroid pulse therapy while replacement therapy for hypothyroidism and hypoadrenocorticism was continued. Conclusions: The patient presented with optic neuritis and hypopituitarism, possibly due to irAEs of the anti-PD-L1 antibody treatment. Steroid pulse therapy was effective for optic neuritis, suggesting underlying immunological mechanisms. Neurological complications including optic neuritis should be considered when examining patients with cancer undergoing CPI treatment

    Dimethyl Fumarate Promotes the Survival of Retinal Ganglion Cells after Optic Nerve Injury, Possibly through the Nrf2/HO-1 Pathway

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    This study aimed to verify whether dimethyl fumarate (DMF) promotes the survival of retinal ganglion cells (RGCs) after optic nerve crush (ONC) accompanied by activation of the NF-E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. We examined changes in the densities of tubulin β3 (TUBB3)-positive RGCs and the amplitudes of the positive scotopic threshold response (pSTR), reflecting the functional activity of RGCs, recorded on an electroretinogram, with daily administration of DMF, on day 7 after ONC. Furthermore, immunohistochemical and immunoblotting analyses were performed to study the activation of the Nrf2/HO-1 pathway using retinas treated with daily administration of DMF. Daily administration of DMF increasedthe density of TUBB3-positive RGCs in a dose-dependent fashion and significantly increased the amplitude of the pSTR. Immunohistochemical analysis showed that DMF administration increased the immunoreactivity for Nrf2 and HO-1, a potent antioxidant enzyme, in RGCs immunolabeled with RNA-binding protein with multiple splicing (RBPMS). Immunoblotting analysis revealed an increase in the nuclear expression of Nrf2 and marked upregulation of HO-1 after DMF administration. These results suggest that DMF has survival-promoting effects in RGC after ONC, possibly via the Nrf2/HO-1 pathway
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