著者
Hiroyuki TAKAO Dai WATANABE Satoshi TANI Hiroki OHASHI Tosihiro ISHIBASHI Kohei TAKESHITA Shigeyuki MURAKAMI Tetsuya NISHIMOTO Kohei YUGE Kostadin KARAGIOZOV Toshiaki ABE Yuichi MURAYAMA
出版者
The Japan Neurosurgical Society
雑誌
Neurologia medico-chirurgica (ISSN:04708105)
巻号頁・発行日
pp.oa.2021-0149, (Released:2021-10-14)
参考文献数
18
被引用文献数
1

A simulation model was developed to better understand the mechanisms of brain injuries in sports. A three-dimensional model comprising approximately 1.22 million elements was constructed from cranial computed tomography images of adult male volunteers by the voxel method. To simulate contact sports that permit actions such as tackling, a sinusoidal wave with duration of 10 ms and maximum acceleration of 2000 m/s2 was applied to the lowest point of the model to apply rotational acceleration to the head from different directions. The von Mises stress was then observed at five points in the coronal plane of the brain: cingulate gyrus (CG), corpus callosum (CC), brain stem (BS), lateral temporal lobe (LT), and medial temporal lobe (MT). LS-DYNA universal finite element analysis software with explicit time integration was used for the analysis. Concentrations of stress started to appear in the CC and BS at 10 ms post-impact, after which they also became evident in the CG and MT. The maximum changes in stress at each location occurred 10–15 ms post-impact. The von Mises stress was 9–14 kPa in the CG, 8–24 kPa in the CC, 12–24 kPa in the BS, 7–12 kPa in the LT, and 12–18 kPa in the MT. The highest stress in every part of the brain occurred after lateral impact, followed by oblique impact and sagittal impact. Such simulations may help elucidate the mechanisms of brain injuries in sports and help develop measures to prevent chronic traumatic encephalopathy.
著者
Tsutomu Matsumoto Junichi Sakamoto Manami Suzuki Dai Watanabe Naoki Yoshida
出版者
Information Processing Society of Japan
雑誌
Journal of Information Processing (ISSN:18826652)
巻号頁・発行日
vol.31, pp.700-707, 2023 (Released:2023-09-15)
参考文献数
25

The RAM encryption encrypts the data on memory to prevent data leakage from an adversary to eavesdrop the memory space of the target program. The well-known implementation is Intel SGX, whose RAM encryption mechanism is definitely hardware dependent. In contrast, Watanabe et al. proposed a fully software-based RAM encryption scheme (SBRES). In this paper, we developed the tools for embedding the SBRES in C source codes for its practical application. We applied the tools to the source codes of some cryptographic implementations in Mbed TLS and confirmed that the tools successfully embedded the SBRES functionality in the cryptographic implementations.
著者
Fumiko Kagiura Ryota Matsuyama Dai Watanabe Yuuki Tsuchihashi Kazuhiko Kanou Takuri Takahashi Yusuke Matsui Masayuki Kakehashi Tomimasa Sunagawa Takuma Shirasaka
出版者
Japan Epidemiological Association
雑誌
Journal of Epidemiology (ISSN:09175040)
巻号頁・発行日
vol.33, no.5, pp.256-261, 2023-05-05 (Released:2023-05-05)
参考文献数
29
被引用文献数
1

Background: The CD4 cell count of patients during diagnosis and distribution of CD4 cell counts in the patient population are important to understand infection-diagnosis interval and incidence rate of human immunodeficiency virus (HIV) infection, respectively. However, this information has not been published in Japan. This study aimed to describe the change in CD4 cell count trends and clarify the change in patients’ characteristics in association with the CD4 cell count information.Methods: A descriptive study was conducted to analyze the medical records of patients with HIV who visited one of the largest acquired immunodeficiency syndrome (AIDS) core hospitals in western Japan. The basic characteristics, CD4 cell counts, viral loads, and diagnosis-treatment intervals between the first (2003–2010) and second (2011–2017) halves of the study duration were compared.Results: The distribution of CD4 cell counts significantly changed between 2003–2010 and 2011–2017 (χ2 = 20.42, P < 0.001). The proportion of CD4 cell count <200 cells/mm3 increased (38.8% in 2003 to 45.9% in 2017), whereas CD4 cell count ≥500 cells/mm3 decreased (19.4% in 2003 to 12.2% in 2017). Moreover, the distributions of age groups, history of HIV screening test, patient outcomes, HIV viral load, and diagnosis-treatment interval also significantly changed (χ2 = 25.55, P < 0.001; χ2 = 8.37, P = 0.015; χ2 = 6.07, P = 0.014; χ2 = 13.36, P = 0.020; χ2 = 173.76, P < 0.001, respectively).Conclusion: This study demonstrated the fundamental trends of the HIV epidemic in Osaka, Japan between 2003–2010 and 2011–2017 and indicated that the incidence rate of HIV was decreasing in Japan.