Keio University
  • Tokyo, Japan
Recent publications
Patients with neurofibromatosis type 1 not only have characteristic skin findings but are also known to have vascular disorders due to vascular vulnerability. A 44-year-old man with previously undiagnosed neurofibromatosis type 1 was brought to the emergency room due to a sudden subcutaneous hematoma with no history of trauma. Angiography revealed extravasation from the parietal branch of the right superficial temporal artery, which was embolized with n-butyl-2-cyanoacrylate. However, the next day, the patient exhibited an increased subcutaneous hematoma, and new extravascular leakage was detected at the frontal branch of the superficial temporal artery, which was also embolized with n-butyl-2-cyanoacrylate. The patient had physical findings characteristic of neurofibromatosis type 1, such as café-au-lait spots, and was subsequently diagnosed with neurofibromatosis type 1. No obvious neurofibroma or any other subcutaneous lesion associated with neurofibromatosis type 1 was identified in the affected area. Massive idiopathic arterial bleeding in the scalp, although infrequent, can be fatal. Neurofibromatosis type 1 should be considered when a subcutaneous scalp hematoma is observed without a history of trauma, even if the facial skin structure appears normal. Neurofibromatosis type 1 is also known to have multiple sources of hemorrhage. Thus, it is important to repeatedly evaluate vascular structures via cerebral angiography, contrast-enhanced computed tomography, and magnetic resonance imaging, if necessary. Fullsize Image
The occipital transtentorial approach (OTA), which is often applied for superior cerebellar lesions, has an inevitable risk of homonymous hemianopsia due to the retraction of the occipital lobe. The endoscopic approach provides increased visibility of the surgical field due to the wide-angled panoramic view and is minimally invasive in approaching deep brain lesions compared to the conventional microscopic approach. However, little is known regarding endoscopic OTA for the removal of cerebellar lesions. We experienced a case of a hemangioblastoma in the paramedian superior surface of the cerebellum that was successfully treated with endoscopic OTA combined with gravity retraction while avoiding postoperative visual dysfunction. A 48-year-old woman was diagnosed with a hemangioblastoma in the superior surface of the cerebellum. She underwent tumor removal with endoscopic OTA combined with gravity retraction of the occipital lobe instead of using brain retractors. The narrower space was sufficient for surgical manipulation with a panoramic view obtained by endoscopy. The simultaneous observation of the lesion with both an endoscope and a microscope revealed the superiority of infratentorial visualization with an endoscope. Gross total removal was achieved with no postoperative complications, including visual dysfunction. Endoscopic OTA may reduce the risk of postoperative visual dysfunction because of its minimally invasive nature, which is enhanced when combined with gravity retraction. Additionally, the panoramic view of the endoscope allows favorable visualization of an infratentorial lesion, which is otherwise hidden partly by the tentorium. The use of endoscopy is compatible with OTA, and endoscopic OTA could be an option for superior cerebellar lesions for avoiding visual dysfunction. Fullsize Image
This study evaluated nanometer gate length germanium (Ge) transistors, including the electrical and thermal components, and compared them with silicon (Si) transistors. Nanometer-scale Ge and Si junction-less field-effect transistors (JLFETs) were treated for both NFET and PFET devices under a transient response. Consequently, the electrical and thermal self-consistent simulations revealed that hole carrier transport is more challenging at the channel region for PFET, inhibiting process shrinking. Moreover, the results show that self-heating can reach a dangerous stature, particularly when the channel region is thick. This is because the operation of the nanometer-scale Ge and Si JLFETs depends on the quantum effect, which increases the band-gap energy. The suitable channel design for Ge and Si transistors is almost similar; a heavier doping concentration is favorable for Si transistors. The study concludes that optimizing the channel region to fit the band-gap energy is the most crucial aspect for designing transistors.
This work presents a frequency doubler (FD) for a microwave-control system intended for an 171Yb+ ion-trap-based quantum computer. The circuit is optimized for frequency multiplication from 11 GHz to 13 GHz with a ≥ 29 dBc fundamental-and third harmonic rejection over the entire frequency range and peak HRR1/HRR3 of 37 dBc/39 dBc. This enables the microwave frequency generation to drive the hyperfine transitions in the electronic ground state of an 171Yb+ ion at 12.6 GHz. Cryogenic measurements of the FD down to 4.5K enable circuit functionality verification for the intended low-temperature operation. Additionally, insights into the cryogenic temperature effects of the employed BiCMOS technology are obtained and used to derive a biasing control methodology for constant performance in the temperature range of 300K to 4.5 K. The proposed circuit is silicon-proven and fabricated in a 0.13μm SiGe BiCMOS process, consuming a core area of only 0.034mm2.
In virtualized environments, virtual CPUs (vCPUs) are commonly oversubscribed on physical CPUs (pCPUs) to utilize CPU resources efficiently. However, excessive vCPU spinning, which occurs when a vCPU is waiting in a spin loop for an event from a descheduled vCPU, greatly degrades application performance in virtualized environments. VM-agnostic hypervisors aim to prevent excessive vCPU spinning by rescheduling vCPUs when an excessive spin is detected by hardware support for virtualization. We investigate the effectiveness of the KVM vCPU scheduler and show that it fails to avoid excessive vCPU spinning under various situations. We identify three problems: 1) scheduler mismatch, 2) aggressive limitation of candidate vCPUs, and 3) IPI context misuse. The first problem stems from the mismatch between the KVM vCPU scheduler and the Linux scheduler. The second and third problems come from failures in choosing candidate vCPUs to be scheduled next. Our in-depth analysis reveals simple modification to KVM (89 LoC) can mitigate excessive vCPU spinning. Our simple modification reduces excessive vCPU spinning by up to 96% and improves benchmark performance by up to 2.6×. Part of the proposed mitigation has been integrated with KVM from Linux KVM v5.13 onward.
Gait measurement in clinical settings is often limited to qualitative evaluations despite the availability of various measurement devices. Although marker-less motion capture techniques, such as Kinect, have been attracting attention recently, they have rarely been introduced in the field because of the complexity of measurement operations. Therefore, we propose a gait measurement algorithm that uses the LiDAR camera of an iPad, a widely used mobile device. First, as part of the floor was hidden by the walking foot, the missing points in the floor point cloud were detected as feet. Subsequently, we placed the potentials at the detected foot positions, summed them over a series of frames, and obtained the local maximum value to obtain the ground position during walking. Spatial gait parameters, such as step length and width, were obtained from the ground position. In an accuracy verification experiment with 13 elderly subjects, the average absolute error of the step length was 28 mm, and that of the step width was 19 mm. These results indicated that the values estimated using the proposed method are useful for evaluating clinical tasks.
Sleep apnea hypopnea syndrome (SAHS) is one of the most common sleeping disorders. However, numerous people suffering from SAHS are left undiagnosed. SAHS causes arousal reactions, sleep fragmentation, and hypoxemia, thus leading to excessive daytime sleepiness, lack of concentration, and a high risk of cardiovascular complications. Although polysomnography is the standard way of SAHS screening, its high cost, limited accessibility, and requirement of operational skills hinder its applicability for SAHS diagnoses. Therefore, this study proposes a novel approach for SAHS detection using a patch-type photoplethysmography sensor. As an initial study, both respiratory and pulse information are simultaneously measured, and the trend of pulse variation, which reportedly has a strong correlation to oxygen saturation (SpO2), is thereby clarified. In addition, more real time measurement of the pulse rate was possible on the chest compared to the fingertip. SAHS detection by incorporating respiratory and pulse information is beneficial for complete and credible screening and risk assessment of cardiovascular complications with less invasive devices. Therefore, this simple patch-type sensor can replace invasive, expensive, and limiting screening methods to facilitate the diagnosis of SAHS.
Occlusion-free video generation is challenging due to surgeons’ obstructions in the camera field of view. Prior work has addressed this issue by installing multiple cameras on a surgical light, hoping some cameras will observe the surgical field with less occlusion. However, this special camera setup poses a new imaging challenge since camera configurations can change every time surgeons move the light, and manual image alignment is required. This paper proposes an algorithm to automate this alignment task. The proposed method detects frames where the lighting system moves, realigns them, and selects the camera with the least occlusion. This algorithm results in a stabilized video with less occlusion. Quantitative results show that our method outperforms conventional approaches. A user study involving medical doctors also confirmed the superiority of our method.
D,L-Propargylglycine (PAG) has been widely used as a selective inhibitor to investigate the biological functions of cystathionine γ-lyase (CSE), which catalyzes the formation of reactive sulfur species (RSS). However, PAG also inhibits other PLP (pyridoxal-5′-phosphate)-dependent enzymes such as methionine γ-lyase (MGL) and L-alanine transaminase (ALT), so highly selective CSE inhibitors are still required. Here, we performed high-throughput screening (HTS) of a large chemical library and identified oxamic hydrazide 1 as a potent inhibitor of CSE (IC50 = 13 ± 1 μM (mean ± S.E.)) with high selectivity over other PLP-dependent enzymes and RSS-generating enzymes. Inhibitor 1 inhibited the enzymatic activity of human CSE in living cells, indicating that it is sufficiently membrane-permeable. X-Ray crystal structure analysis of the complex of rat CSE (rCSE) with 1 revealed that 1 forms a Schiff base linkage with the cofactor PLP in the active site of rCSE. PLP in the active site may be a promising target for development of selective inhibitors of PLP-dependent enzymes, including RSS-generating enzymes such as cystathionine β-synthase (CBS) and cysteinyl-tRNA synthetase 2 (CARS2), which have unique substrate binding pocket structures.
Sense of control refers to a person’s belief that he or she is capable of obtaining desired outcomes, avoiding undesired outcomes, and achieving goals. This concept has been raised and studied by sociologists, but in recent years, there has been a gradual increase in research on the impact of consumer sense of control. However, a comprehensive review in this field is still lacking. This paper provides an overview of previous research on four aspects of consumer sense of control: (1) sense of control and compensatory behavior, (2) sense of control and emotional coping, (3) sense of control and charitable behavior, and (4) desire for control. Furthermore, the paper highlights three directions as key areas of future research: (a) exploring antecedents of sense of control, (b) investigating underlying psychological mechanisms of compensatory behavior resulting from a reduced sense of control, and (c) examining moderating effects on desire for control.
The location-based game “Station Memories!”, in which players travel around more than 9,000 stations throughout Japan with bishôjo (animated beautiful girl) characters, has recently become an online-to-offline (O2O) destination marketing approach for railroad companies and local governments that are suffering from a decrease in passengers. By holding a short-term local digital stamp rally featuring a bishôjo character, this approach has succeeded in attracting three kinds of otaku—game otaku, railroad otaku, and bishôjo character otaku—who are enthusiastic about the game and willing to spend much of their time and money to visit the destination where the digital stamp rally is held. This paper reviews some of the many successes of “Station Memories!” campaigns and discusses its potential as an O2O destination marketing model.
Allium macrostemon Bunge, commonly referred to as "no-biru" in Japan, is a widespread wild onion species found across the country. Despite being deeply entwined in ancient Japanese culture, it remains an underutilized crop in Japan. Determining the origins of its domestic populations and understanding their genetic composition is crucial to highlighting the plant's historical significance in Japan. This study aims to bridge this knowledge gap by examining the genetic diversity of 47 A. macrostemon samples from various regions in Japan using RAD-Seq. Our analyses distinguished unique population structures, dividing the samples into three distinct groups: A, B, and C. Notably, groups A and B showed clear evidence of bulb propagation, while group C did not. Group C formed four subgroups: C1, C2, C3, and C4. Hybridization between subgroup C1 and either group A, B, or both, resulted in the emergence of subgroups C2, C3, and C4. Thus, groups A, B, and C1 are posited as the ancestral populations. Additionally, our morphological observations indicated distinct differences among these three groups. Our findings also suggest that human migration may have influenced the plant's distribution, hinting at active usage in the past that later waned, causing its current underutilized status.
We report a sizable Dzyaloshinskii-Moriya interaction (DMI) originating at an epitaxial Fe3Si/Ge interface. Using spin-wave spectroscopy, we show that the magnitude of the interfacial DMI of the Heusler-ferromagnet/semiconductor hybrid structure is comparable to that of ferromagnet/Pt structures, despite the absence of heavy elements. We find that the observed DMI at the Fe3Si/Ge interface is consistent with the prediction of an antisymmetric exchange interaction induced by the interfacial Bychkov-Rashba spin-orbit interaction. These results demonstrate that ferromagnet/semiconductor hybrid structures are a promising class of systems for chiral spintronics.
Background: High levels of circulating adiponectin are associated with increased insulin sensitivity, low prevalence of diabetes, and low body mass index (BMI); however, high levels of circulating adiponectin are also associated with increased mortality in the 60-70 age group. In this study, we aimed to clarify factors associated with circulating high-molecular-weight (cHMW) adiponectin levels and their association with mortality in the very old (85-89 years old) and centenarians. Methods: The study included 812 (women: 84.4%) for centenarians and 1,498 (women: 51.7%) for the very old. The genomic DNA sequence data were obtained by whole genome sequencing or DNA microarray-imputation methods. LASSO and multivariate regression analyses were used to evaluate cHMW adiponectin characteristics and associated factors. All-cause mortality was analyzed in three quantile groups of cHMW adiponectin levels using Cox regression. Results: The cHMW adiponectin levels were increased significantly beyond 100 years of age, were negatively associated with diabetes prevalence, and were associated with SNVs in CDH13 (p = 2.21 × 10 ⁻²² ) and ADIPOQ (p = 5.72 × 10 ⁻⁷ ). Multivariate regression analysis revealed that genetic variants, BMI, and high-density lipoprotein cholesterol (HDLC) were the main factors associated with cHMW adiponectin levels in the very old, whereas the BMI showed no association in centenarians. The hazard ratios for all-cause mortality in the intermediate and high cHMW adiponectin groups in very old men were significantly higher rather than those for all-cause mortality in the low level cHMW adiponectin group, even after adjustment with BMI. In contrast, the hazard ratios for all-cause mortality were significantly higher for high cHMW adiponectin groups in very old women, but were not significant after adjustment with BMI. Conclusions: cHMW adiponectin levels increased with age until centenarians, and the contribution of known major factors associated with cHMW adiponectin levels, including BMI and HDLC, varies with age, suggesting that its physiological significance also varies with age in the oldest old. Funding: This study was supported by grants from the Ministry of Health, Welfare, and Labour for the Scientific Research Projects for Longevity; a Grant-in-Aid for Scientific Research (No 21590775, 24590898, 15KT0009, 18H03055, 20K20409, 20K07792, 23H03337) from the Japan Society for the Promotion of Science; Keio University Global Research Institute (KGRI), Kanagawa Institute of Industrial Science and Technology (KISTEC), Japan Science and Technology Agency (JST) Research Complex Program 'Tonomachi Research Complex' Wellbeing Research Campus: Creating new values through technological and social innovation (JP15667051), the Program for an Integrated Database of Clinical and Genomic Information from the Japan Agency for Medical Research and Development (No. 16kk0205009h001, 17jm0210051h0001, 19dk0207045h0001); the medical-welfare-food-agriculture collaborative consortium project from the Japan Ministry of Agriculture, Forestry, and Fisheries; and the Biobank Japan Program from the Ministry of Education, Culture, Sports, and Technology.
Although the economic burden of multimorbidity is a growing global challenge, the contribution of multimorbidity in patients with high medical expenses remains unclear. We aimed to clarify multimorbidity patterns that have a large impact on medical costs in the Japanese population. We conducted a cross-sectional study using health insurance claims data provided by the Japan Health Insurance Association. Latent class analysis (LCA) was used to identify multimorbidity patterns in 1,698,902 patients who had the top 10% of total medical costs in 2015. The present parameters of the LCA model included 68 disease labels that were frequent among this population. Moreover, subgroup analysis was performed using a generalized linear model (GLM) to assess the factors influencing annual medical cost and 5-year mortality. As a result of obtaining 30 latent classes, the kidney disease class required the most expensive cost per capita, while the highest portion (28.6%) of the total medical cost was spent on metabolic syndrome (MetS) classes, which were characterized by hypertension, dyslipidemia, and type 2 diabetes. GLM applied to patients with MetS classes showed that cardiovascular diseases or complex conditions, including malignancies, were powerful determinants of medical cost and mortality. MetS was classified into 7 classes based on real-world data and accounts for a large portion of the total medical costs. MetS classes with cardiovascular diseases or complex conditions, including malignancies, have a significant impact on medical costs and mortality.
Discrimination, which arose during the coronavirus disease 2019 outbreak, is a global public health issue. This study aimed to provide fundamental knowledge in proposing control measures to mitigate discrimination. We focused on two psychological variables: belief in just deserts (BJD, i.e. , the belief that the infected individual deserves to be infected), a psychological factor that potentially promotes discrimination and prejudice, and human rights restrictions (HRR; i.e. , the degree of individuals’ agreement with government restrictions on citizens’ behavior during emergencies). Differences in these items, as well as their annual trends from 2020 to 2022, were examined in Japan, the United States (US), the United Kingdom (UK), Italy, and China. In addition, the associations between BJD and HRR by country and year and the direction of the associations between them in Japan and Italy were analyzed. Online surveys were conducted annually, with 392–518 participants per country and year. The BJD was higher in Japan and lower in the UK. BJD increased significantly from 2020 to 2021 in all countries, except in China. Meanwhile, HRR was higher in China and lower in Japan. The HRR decreased from 2020 to 2021 in Japan and decreased from 2020 to 2022 in the US, the UK, and Italy. There were significant positive associations between BJD and HRR in Japan and Italy. Cross-lagged panel models revealed positive bidirectional associations between BJD and HRR in Japan and Italy, respectively, indicating that the HRR declined among those with weak BJD and that the BJD increased among those with high HRR. In Japan and Italy, the dissemination of public messages targeting those with a high HRR in the early stages of an infectious disease outbreak could potentially mitigate the adverse impact of the BJD, eventually reducing discrimination, especially when the infection is not attributed to the fault of the infected individuals.
Introduction: Although laryngeal abscess is a rare disease in this day when antibiotics and vaccines are widely available, it can be fatal in terms of choking risk due to airway narrowing and thus requires an immediate diagnosis and treatment, including airway management. Even in the field of oral surgery, where nasogastric tubes are often used for nutritional management, there have been no reports of laryngeal abscesses. Case Report: One month after right maxillary gingival carcinoma surgery, a 72-year-old man had hoarseness and a fever following nasogastric tube replacement, and blood tests showed a marked increase in inflammatory levels. The patient started chemotherapy with SBT/ABPC (12 g/day). Contrast-enhanced magnetic resonance imaging showed a low-density area with a rim enhancement effect from the left laryngeal surface of the epiglottis to the left supraglottis, which had caused airway narrowing, leading to a diagnosis of laryngeal abscess. Considering the risk of airway obstruction, a tracheostomy was performed under general anesthesia. On day 16, contrast-enhanced computed tomography showed a reduction in the lesion size. On day 36, antibiotic chemotherapy was terminated. At 10 months after surgery, lung metastasis developed without local or cervical recurrence, and chemotherapy was off-label due to his worsening renal function. Therefore, the best supportive care policy was selected. The patient’s general condition gradually deteriorated, and he died 11 months after the surgery. Conclusion: There are very few reports related to nasogastric tubes, so it is necessary to keep the disease concept of laryngeal abscess in mind, especially in the field of oral surgery, where nasogastric tubes are often used for nutritional management.
Dermaptera is a polyneopteran insect order that includes more than 2,000 described species, commonly known as earwigs, that mainly inhabit tropical, subtropical and warm temperate regions. Although 40 species have been found in Japan, their distribution and habitat preferences have remained ambiguous due to sample misidentification, particularly amongst immature specimens. To overcome this problem, we sequenced and analysed the DNA barcoding region of the mitochondrial cytochrome oxidase I gene ( cox1 ) of dermapteran species recorded from Japan. Including publicly available data, 72.5% of known Japanese dermapteran species were subjected to molecular identification. We extensively sampled three wingless species of subfamily Anisolabidinae (Anisolabididae): Anisolabis maritima , Anisolabella marginalis and Euborellia pallipes . Although these species exhibit similar habitat preferences as semi-synanthropes, A. maritima , a cosmopolitan species with the highest affinity to seashore, had significantly higher sequence diversity than the latter two species, which are considered endemic to East Asia. A similar trend was observed for (at least partly) winged cosmopolitan species of other families. Introgression with the congener Anisolabis seirokui is also suggested for A. maritima . Possible causes of the varying levels of sequence diversity are discussed.
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6,022 members
Daisuke Fujisawa
  • Department of Neuropsychiatry
Takemitsu Morikawa
  • Department of Sociology
Shunsuke Kimura
  • Faculty of pharmacy
Yohei Mikami
  • Department of Internal Medicine
Daiki Horikawa
  • Graduate School of Media and Governance
Tokyo, Japan