115 research outputs found
Asymptotic behavior of null geodesics near future null infinity IV: Null-access theorem for generic asymptotically flat spacetime
In our previous papers [arXiv:2106.03150, arXiv:2110.10917,
arXiv:2208.00822], we analyzed the asymptotic behavior of future directed null
geodesics near future null infinity and then we showed a proposition on the
accessibility of the null geodesics to future null infinity in a specific class
of asymptotically flat spacetimes. In this paper, we adopt the retarded time of
the Bondi coordinate as the parameter for the null geodesics and then see that
one can relax the assumptions imposed in our previous studies. As a
consequence, we obtain a new null-access theorem for generic asymptotically
flat spacetimes.Comment: 16 pages, no figure
Four types of attractive gravity probe surfaces
We reexamine the concept of the attractive gravity probe surface recently
proposed as an indicator for strength of gravity. Then, we propose three new
variant concepts and show refined inequalities for the four types of the AGPSs
by taking account of the angular momentum, gravitational waves and matters.Comment: 25 pages, 2 figure
Two Cases of Nivolumab Re-Administration after Pneumonitis as Immune-Related Adverse Events
Nivolumab is a recently approved medication for the treatment of unresectable malignant melanoma. Many immune-related adverse events (irAEs) associated with nivolumab have been reported, such as pneumonitis, hepatitis, dermatitis, and thyroiditis. Prednisolone can effectively treat irAEs. However, it is unclear how or if nivolumab should be administered to patients after they have experienced an irAE. Herein, we show 2 patients who underwent pneumonitis as irAE. Case 1 demonstrated a cryptogenic organizing pneumonia pattern in the CT scan and case 2 had a diffuse alveolar damage (DAD) pattern. Oral corticosteroids improved chest shadow of CT scan in both cases. However, when nivolumab was re-administrated, case 1 demonstrated no symptoms, but case 2 demonstrated pneumonia again. From our cases, it is difficult to re-administrate nivolumab for the patients with pneumonitis which shows a DAD pattern in CT, even if oral corticosteroids improve their symptoms
A Case Report of Primordial Odontogenic Tumor That Required Distinction from a Dentigerous Cyst
Primordial odontogenic tumor (POT) is a rare odontogenic tumor characterized by a variably cellular loose fibrous tissue with areas similar to the dental papilla and covered by cuboidal to columnar epithelium. We herein report a case of POT in a 14-year-old boy. Computed tomography (CT) exhibited a round cavity with a defined cortical border circumscribing the tooth of the second molar. However, the gross finding was a solid mass, not a cyst. Histologically, the tumor consisted of dental papillalike myxoid connective tissue covered by columnar epithelium. Therefore, although the clinical diagnosis was dentigerous cyst (DC), we diagnosed POT based on histologic findings. Clinical findings of POT resemble DC, but the clinical behavior of POT is different to DC, such as cortical expansion and root resorption of teeth. Therefore, histological differentiation of POT from DC is critical for accurate diagnosis
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