University of the Ryukyus
  • Okinawa, Okinawa, Japan
Recent publications
Verification of the manufacturing conditions for translucency ceramics are showed using powder forming and sintering method in order to establish the manufacturing technology for optical devices with arbitrary complex shape and shape retention, and optical excitation materials. However, this method is extremely difficult to obtain translucency ceramics because the combination of complex factors such as “the shape and particle size of the raw materials, forming conditions and sintering” adversely affect the translucency of the sintered material, which is caused by the transmitted light scattering of the sintered material. Therefore, we have succeeded in realizing transparent ceramics by examining these complicated factors (materials, molding, sintering conditions, crystallization) and specifying the amorphous sintering conditions and the densification-molding conditions necessary to eliminate the light scattering factors inherent in sintered materials. It is necessary to show the correlation of the volume change with respect to Tg-temperature and Tm-temperature, which are important regarding amorphization, considering the sintering treatment conditions that depend on the particle size of the raw material fine powder, and to specify the molding body-pressurization (pressure and time) conditions. These optimizations will make it possible to develop the expected high-functional-photoelectric optical devices with microstructures and, high-power laser light sources independent of materials. This Paper was Originally Published in Japanese in J. Jpn. Soc. Powder Powder Metallurgy 68 (2021) 409–414.
Background The COVID-19 epidemic has been repeated worldwide; however, easily accessible treatment options for patients with mild COVID-19 remain limited. Since the Lactococcus lactis strain plasma (LC- Plasma) enhances both the innate and acquired immune systems through the activation of plasmacytoid dendritic cells (pDCs), we hypothesized that the oral intake of LC-Plasma could ease symptoms in patients with mild COVID-19. Methods The study protocol was registered in Japan Registry of Clinical Trials (jRCTs071210097). A total of 100 patients with mild COVID-19 were enrolled from January through March 2022 during epidemic timing of omicron BA.1 strain. Patients were randomly assigned by allocation factors of age, anti-viral medication, and SARS-CoV-2 vaccine status in a 1:1 ratio to LC-Plasma group (oral LC- Plasma- capsule, 200 mg/day, for 14 days) or placebo (oral placebo capsule, for 14 days). The primary endpoint was the change in total severity score of 8 subjective symptoms. Secondary endpoints include the change of each subjective symptom, SARS-CoV-2 viral loads, pDC activation, serum SARS-CoV-2 specific antibodies, type I interferons, and the proportion of subjects with emergency room visits or who were hospitalized. Results A total of 50 patients in LC-Plasma group and 46 patients (4 omitted by declining the participation or unsatisfied criteria) in placebo group were analyzed. There was no difference between groups in patients’ background including age, sex, body mass index, and SARS-CoV-2 vaccination status (Table 1). The primary endpoint, total score of symptoms, was not different between groups (Figure 1A). As secondary endpoint, LC-Plasma group disappeared smell and taste disorders after day 9 compared to placebo group (p< 0.05, Figure 1B). Additionally, SARS-CoV-2 viral load was significantly decreased at day 4 in LC-Plasma group (p< 0.05, Figure 2A). Also, pDC decreased in the placebo group during the course, however, has maintained in LC-Plasma group (p< 0.05, Figure 2B). No patient was hospitalized or visited ER during the study. No adverse effect was reported except diarrhea observed in one patient in the LC Plasma group. Patients' backgrounds A. Change of total score (vs day1, 8 symptoms). B. % patients without smell & taste disorders A. Change of SARS-CoV-2 viral load: (log change/day1)×100%. B. Chage of pDC (vs day1×100%) Conclusion LC-Plasma is safe and a potential adjunctive treatment to maintain immunity, fasten viral eradication, and ease symptoms for mild COVID-19. Disclosures Kazuko Yamamoto, MD, PhD, Fisher & Paykel Healthcare: Grant/Research Support|Kirin Holdings Co.: Grant/Research Support Tsuyoshi Inoue, MD, PhD, Kirin Holdings Co.: Grant/Research Support|Kyowa Kirin Co.: donated course Kenta Jounai, PhD, Kirin Holdings Co.: Employee Ryohei Tsuji, PhD, Kirin Holdings Co.: Employee Daisuke Fujiwara, PhD, Kirin Holdings Co.: Employee Katsunori Yanagihara, MD, PhD, FUJIFILM Toyama Chemical Co., Ltd.: Commissioned research|KYORIN Pharmaceutical Co.,Ltd.: Commissioned research Koichi Izumikawa, M.D., Ph.D., Asahi Kasei Pharma Corporation: Grant/Research Support|Asahi Kasei Pharma Corporation: Honoraria|Astellas Pharma Inc.: Honoraria|DAIICHI SANKYO COMPANY, LIMITED: Grant/Research Support|DAIICHI SANKYO COMPANY, LIMITED: Honoraria|KYORIN Pharmaceutical Co.,Ltd.: Honoraria|Merck & Co., Inc.: Honoraria|Pfizer Japan Inc.: Honoraria|Shionogi & Co., Ltd.: Grant/Research Support|Shionogi & Co., Ltd.: Honoraria|Sumitomo Pharma Co., Ltd.: Grant/Research Support|Sumitomo Pharma Co., Ltd.: Honoraria|TAIHO PHARMACEUTICAL CO., LTD.: Grant/Research Support
Background Hypervirulent Klebsiella pneumoniae (hvKp) is associated with severe clinical outcomes, including liver abscesses and disseminated infections (Fig 1). The hypermucoviscosity phenotype (HMV), confirmed by the String test, has been linked to hvKP. This study aimed to investigate the prevalence and genomic characteristics of HMV-Kp isolates in patients with K. pneumoniae bacteremia in a single medical center in Japan.Figure 1.The case of endophthalmitis and multiple abscesses by hypermucovisucosity phenotype K. pneumoniae Methods We conducted a retrospective study at University of the Ryukyus Hospital between January 2021 and November 2022, extracting patients with HMV-Kp bacteremia. K. pneumoniae isolates were subjected to String test (Fig 2), antimicrobial susceptibility testing, and genomic analysis. Whole-genome sequencing and genomic analysis were conducted to identify multilocus sequence type (MLST), K capsule serotype, virulence genes, and antimicrobial resistance genes.Figure 2.String test Results During the study period, 29 cases of K. pneumoniae bacteremia were identified, with six cases of HMV-Kp bacteremia. Five of these cases were male patients and had organ abscess formation (Table 1). The results of the genomic analysis are shown in Table 2. All six HMV-Kp strains were positive for rmpA/rmpA2. MLST and K serotyping revealed that two isolates belong to ST23-K1 and ST86-K2, a known hypervirulent clone. All strains contained virulence genes, with the two ST23-K1 strains carrying all the typical hvKp virulence genes. No strains harbored ESBL or carbapenemase genes.Table 1.Clinical backgrounds of the cases.Table 2.Sequence typing and Virulence genes of the isolates. Conclusion All HMV-Kp strains isolated in this study carried virulent genes, including the hvKP clones ST23-K1 and ST86-K2. The String test for HMV phenotype confirmation appears useful to estimate the presence of hvKp. Our findings provide insights into the virulence and potential clinical implications of HMV-Kp isolates in Japan, highlighting the need for further investigation and monitoring. Disclosures Kazuko Yamamoto, MD, PhD, Fisher & Paykel Healthcare: Grant/Research Support|Kirin Holdings Co.: Grant/Research Support
One of the challenges facing modern large-scale wind turbines stems from the shaft which has a finite stiffness, leading to shaft torsional oscillation which creates fatigue fractures and overload in the shaft system causing unexpected downtime of the wind turbines (WTs). In this study, the shaft torsional oscillation is investigated using a two-mass model of the shaft system. The permanent magnet synchronous generator is operated as a suppressor to mitigate the shaft torsional oscillation by implementing an H∞ controller in the speed control loop, thereby enabling the closed-loop control system to reduce the effect of shaft torsional oscillation. Another challenge lies in inability to directly measure the shaft torsional torque. Thus, the shaft torsional torque estimate is obtained by the H∞ observer. Both observer and controller are designed using the linear matrix inequality method. The simulation results were obtained using Matlab/Simulink@ to analyze the effectiveness of the proposed control under highly oscillated wind. Based on the results, the shaft torsional motion was mitigated by the suggested control technique as compared to the standard control method. The estimate result proved that the H∞ observer was effective under various conditions that affect the performance of the observer.
Phytoplanktonic dinoflagellates form colonies between vertical ice crystals during the ice-melting season in Lake Baikal, but how the plankton survive the freezing conditions is not known. Here we show that the phytoplankton produces large amounts of dimethylsulfoniopropionate (DMSP), which is best-known as a marine compound. Lake-water DMSP concentrations in the spring season are comparable with those in the oceans, and colony water in ice exhibits extremely high concentrations. DMSP concentration of surface water correlates with plankton density and reaches a maximum in mid-April, with temperature-dependent fluctuations. DMSP is released from plankton cells into water in warm days. DMSP is a characteristic osmolyte of marine algae; our results demonstrate that freshwater plankton, Gymnodinium baicalense, has DMSP-producing ability, and efficiently uses the limited sulfur resource (only 1/500 of sea sulfate) to survive in freshwater ice. Plankton in Lake Baikal do not need an osmolyte, and our results clearly indicate that DMSP plays a cryoprotective role. DMSP, although a characteristic marine compound, could also be an important zwitterion for algae of other boreal lakes, alpine snow, and glaciers.
Forecast and numerical simulation studies on meso/micro-scale high-impact weathers using high-performance computing infrastructures (HPCIs) in Japan are reviewed. First, we refer to the Japanese world top-ranking supercomputers (Earth Simulator, K computer, and supercomputer Fugaku). Next, we review symbolical scientific achievements on meso/micro-scale high-impact weathers (e.g., heavy rainfall and tornado) mainly obtained using the K computer and the supercomputer Fugaku.
To investigate the frequency of pneumonia and chest computed tomography (CT) findings in patients with coronavirus disease 2019 (COVID-19) during the fifth Delta variant-predominant and sixth Omicron variant-predominant waves of the COVID-19 pandemic in Okinawa, Japan. A survey on chest CT examinations for patients with COVID-19 was conducted byhospitals with board-certified radiologists who provided treatment for COVID-19 pneumonia in Okinawa Prefecture. Data from 11 facilities were investigated. Indications for chest CT; number of COVID-19 patients undergoing chest CT; number of patients with late-onset pneumonia, tracheal intubation, and number of deaths; and COVID-19 Reporting and Data System classifications of initial chest CT scans were compared by the chi-squared test between the two pandemic waves (Delta vs. Omicron variants). A total of 1944 CT scans were performed during the fifth wave, and 1178 were performed during the sixth wave. CT implementation rates, which were the number of patients with COVID-19 undergoing CT examinations divided by the total number of COVID-19 cases in Okinawa Prefecture during the waves, were 7.1% for the fifth wave and 2.1% for the sixth wave. The rates of tracheal intubation and mortality were higher in the fifth wave. Differences between the distributions of the CO-RADS classifications were statistically significant for the fifth and sixth waves (p < 0.0001). In the fifth wave, CO-RADS 5 (typical of COVID-19) was most common (65%); in the sixth wave, CO-RADS 1 (no findings of pneumonia) was most common (50%). The finding of “typical for other infection but not COVID-19” was more frequent in the sixth than in the fifth wave (13.6% vs. 1.9%, respectively). The frequencies of pneumonia and typical CT findings were higher in the fifth Delta variant-predominant wave, and nontypical CT findings were more frequent in the sixth Omicron variant-predominant wave of the COVID-19 pandemic in Okinawa, Japan.
Aims Although sarcopenia is common and associated with poor outcomes in patients with heart failure, its simple screening methods remain unclear. We aimed to investigate the predictive value of the Ishii score, which includes age, grip strength, and calf circumference, for sarcopenia and its prognostic predictability in patients with heart failure. Methods This was a subanalysis of the FRAGILE‐HF study. Receiver operating characteristic curves were used to evaluate the predictive value for sarcopenia. Patients were stratified into the high and low Ishii score groups based on the cutoff values of the Ishii score determined by the Youden index for sarcopenia, and the 1‐year mortality rates were compared. Results Of the 1262 study participants, 936 were evaluated with sarcopenia, and 184 (55 women, 129 men) were diagnosed with sarcopenia. The areas under the receiver operating characteristic curves for sarcopenia were 0.73 and 0.87 for women and men, respectively. The optimal cutoff values for predicting sarcopenia were 165 and 141 for women and men, respectively. Using these cutoff values, the sensitivity and specificity for sarcopenia were 70.9% and 68.5% for women and 88.4% and 69.7% for men, respectively. At 1 year, 151 (low Ishii score group, 98; high Ishii score group, 53) deaths were observed. Adjusted Cox proportional hazards analysis showed that the high Ishii score group was significantly associated with 1‐year mortality. Conclusion Among older patients hospitalized for heart failure, the Ishii score is useful for predicting sarcopenia and 1‐year mortality. Geriatr Gerontol Int 2023; ••: ••–•• .
Aim The aim of this study was to verify the clinical feasibility of tele‐proctoring using our ultra‐low latency communication system with shared internet access. Methods Connections between two multiple remote locations at various distances were established through the TELEPRO® tele‐proctoring system. The server records the latency between the two locations for tele‐proctoring using the annotations. Questionnaires were administered to the surgeons, assistants, and medical staff. Respondents rated the quickness and quality of communication in terms of latency and disturbances in the audio, video, and usefulness of the live telestrations with annotation. Results Seven hospitals tele‐proctored with Sapporo Medical University between January 2021 and September 2022. The median latency of annotation between the two locations ranged from 24.5 to 48.5 ms. No major technological problems occurred, such as streaming interruption, loss of video or audio, poor resolution. The video encoding time was 10 ms, and its decoding time was 0.8 ms. The total latency positively correlated with the distance between two locations ( R = 0.55, p < 0.01). The quality of communication regarding latency, disturbance, and surgical education with intraoperative annotative instructions showed similar trends, with perfectly fine being the most common response. No significant differences in surgical quality, educational effect, or social impact were observed between the latency ≥30 and <30 ms groups for whether the size of latency affects surgical education. Conclusion The feasibility of the tele‐proctoring system is expected to be a sustainable approach to help education for young surgeons and surgical supports in rural areas, thereby reducing disparities in health care.
Global warming harms coral reefs. Mesophotic coral reef ecosystems (MCEs) have been suggested to serve as refugia for shallow reefs. Information on the adaptation potential of shallow corals at MCEs is a prerequisite for understanding the refuge potential of MCEs. In this study, we investigated the photoacclimation potential of four shallow coral species transplanted at different depths over 1 year. The results showed that the corals—Pocillopora damicornis, Porites cylindrica, and Turbinaria reniformis—survived and acclimated to a wide range of light regimes at the depths of 5, 20, and 40 m. However, Acropora tenuis survived only at 5 and 20 m depth and showed significant morphological alteration at 20 m depth. Our results indicate that shallow corals have substantial plasticity with respect to depth changes. Changes in photosynthetic performance and phenotypic plasticity within these coral species may act as a buffer for depth-related changes and as modulators of evolutionary responses.
Background In open thoracoabdominal aortic aneurysm (TAAA) repair, we have been performing vascular reconstruction under moderate to deep hypothermia and assisted circulation using simultaneous upper and lower body perfusion. This method is effective for protecting the spinal cord and the brain, heart, and abdominal organs and for avoiding lung damage. Methods TAAA repair was performed under hypothermia at 20–28 °C in 18 cases (Crawford type I in 0 cases, type II in 5, type III in 3, type IV in 4, and Safi V in 6) between October 2014 and January 2023. Cardiopulmonary bypass was conducted by combined upper and lower body perfusion, with perfusion both via the femoral artery and either transapically or via the descending aorta or the left brachial artery. Results The ischemic time for the artery of Adamkiewicz and the main segmental arteries was 40–124 min (75 ± 33 min). No spinal cord ischemic injury or brain or heart complications occurred. One patient with postoperative right renal artery occlusion and one with an infected aneurysm required tracheostomy, but the intubation time for the other 16 was 32 ± 33 h. The duration of postoperative intensive care unit stay was 6.5 ± 6.2 days, the length of hospital stay was 29 ± 15 days, and no in-hospital deaths occurred. Conclusions Simultaneous upper and lower body perfusion under moderate to deep hypothermia during thoracoabdominal aortic surgery may avoid not only spinal cord injury, but also cardiac and brain complications.
Nanipora Miyazaki & Reimer, 2015 is a recently described monotypic octocoral genus belonging to the family Helioporidae (class Octocorallia). Nanipora kamurai Miyazaki & Reimer, 2015 was formally described from shallow coral reefs around Zamami Island, within Kerama-shoto National Park, in Okinawa Prefecture, southern Japan. To date, Nanipora has been reported from two other locations in Japan: N. aff. kamurai from a shallow inner lagoon at Iriomotejima Island, and Nanipora cf. kamurai from the coral reef surrounding a shallow CO2 vent at Iotorishima Island, both in Okinawa Prefecture. Additionally, Nanipora cf. kamurai has been reported from three locations outside Japan: in shallow seagrass meadows at Dongsha Atoll in the South China Sea, on coral reefs at Koh Tao in Thailand and from a reef in Toboso, central Philippines. Finally, N. kamurai has been detected in environmental DNA samples from the Rowley Shoals off northwestern Australia. As a ‘living fossil’ and also apparently common in the low pH environment of Iotorishima I., a clearer understanding of the distribution of the genus should aid in better understanding of its ecology. Here, we report three new additional records from the Ryukyu Archipelago where Nanipora colonies were found, resulting in ten total records of Nanipora. Molecular phylogenetic analyses utilizing cytochrome oxidase subunit I (COI), mitochondrial mismatch repair protein (mtMutS), and the internal transcribed spacer region (ITS) sequences of specimens from two of these new locations combined with additional sequences from previously collected specimens from Dongsha, Iotorishima, and Iriomotejima showed evidence of three closely related groups within Nanipora, warranting future investigations into the species diversity of this genus.
Background Sterile inflammation caused by metabolic disorders impairs endothelial function; however, the underlying mechanism by which hyperglycemia induces inflammation remains obscure. Recent studies have suggested that stimulator of interferon genes (STING), a key cytosolic DNA sensor in the innate immune system, contributes to the pathogenesis of inflammatory diseases. This study examines the role of the STING in endothelial dysfunction in streptozotocin‐induced diabetic mice. Methods and Results Injection of streptozotocin promoted the expression of STING and DNA damage markers in the aorta of wild‐type mice. Streptozotocin elevated blood glucose and lipid levels in both wild‐type and STING‐deficient mice, which showed no statistical differences. Genetic deletion of STING ameliorated endothelial dysfunction as determined by the vascular relaxation in response to acetylcholine ( P <0.001) and increased endothelial nitric oxide synthase phosphorylation in the aorta ( P <0.05) in STZ‐injected mice. Endothelium‐independent vascular response to sodium nitroprusside did not differ. Treatment with a direct STING agonist, cyclic GMP‐AMP, or mitochondrial DNA increased inflammatory molecule expression (eg, VCAM1 and IFNB ) and decreased endothelial nitric oxide synthase phosphorylation in human umbilical vein endothelial cells, partially through the STING pathway. Cyclic GMP‐AMP significantly impaired endothelial function of aortic segments obtained from wild‐type mice, which was ameliorated in the presence of C‐176, a STING inhibitor, or a neutralizing interferon‐β antibody. Furthermore, the administration of C‐176 ameliorated endothelial dysfunction in STZ‐induced diabetic mice ( P <0.01). Conclusions The DNA damage response regulated by STING impairs endothelial function. STING signaling may be a potential therapeutic target of endothelial dysfunction caused by hyperglycemia.
Main conclusion Each β-1,3-glucanase with antifungal activity or yeast lytic activity hydrolyzes different structures of β-1,3-glucans in the fungal cell wall, respectively. Abstract Plants express several glycoside hydrolases that target chitin and β-glucan in fungal cell walls and inhibit pathogenic fungal infection. An antifungal β-1,3-glucanase was purified from gazyumaru (Ficus microcarpa) latex, designated as GlxGluA, and the corresponding gene was cloned and expressed in Escherichia coli. The sequence shows that GlxGluA belongs to glycoside hydrolase family 17 (GH17). To investigate how GlxGluA acts to degrade fungal cell wall β-glucan, it was compared with β-1,3-glucanase with different substrate specificities. We obtained recombinant β-1,3-glucanase (designated as CcGluA), which belongs to GH64, from the bacterium Cellulosimicrobium cellulans. GlxGluA inhibited the growth of the filamentous fungus Trichoderma viride but was unable to lyse the yeast Saccharomyces cerevisiae. In contrast, CcGluA lysed yeast cells but had a negligible inhibitory effect on the growth of filamentous fungi. GlxGluA degraded the cell wall of T. viride better than CcGluA, whereas CcGluA degraded the cell wall of S. cerevisiae more efficiently than GlxGluA. These results suggest that the target substrates in fungal cell walls differ between GlxGluA (GH17 class I β-1,3-glucanase) and CcGluA (GH64 β-1,3-glucanase).
The reef-building coral genus Acropora is essential for coral reefs due to its role in the reef, as a habitat for other marine organisms. The diversity of coral species might have arisen explosively, accompanied by hybridization in response to historical climate change, Pleistocene, with sea level changes. Here, we aimed from integrative approaches (morphology, genetics, and reproduction) to evaluate the speciation history of the four tabular Acropora species ( Acropora aff hyacinthus , A . cf bifurcata , A . cf cytherea , and A . cf subulata ). Here, we show that introgression might have a minor role in specifying the four tabular Acropora spp. Instead, rapid genetic divergence occurred, accompanied by morphological differences and gamete incompatibility. Furthermore, extensive morphological analyses showed that these four species were distinguishable from morphology, and their gamete incompatibility was sufficiently high to prevent hybridization. Population structure and principal component analyses with the SNPs (>60,000) indicated these four species were also distinctive, and the ABBA-BABA test did not support introgression among these species. In addition, many coding and noncoding RNA sequences were in the high genetic variances among four species with high Fst loci along the genome. Comparing these orthologs among other Acropora species suggests that many of these genes were under positive selection, which could be associated with their divergence at spawning time, gamete incompatibility, and morphological differences. These results show that the speciation of the tabular Acropora occurred without hybridization, and divergence accompanying the genes’ rapid evolution could be associated with specifying in the species-rich Acropora .
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946 members
Yoshihide Ogawa
  • Graduate School of Medicine
Kazuki Tsuji
  • Faculty of Agriculture
Hiroyuki Arakawa
  • Graduate School of Medicine
Masayuki Matsushita
  • Department of Molecular and Cellular Physiology
1 Senbaru, Nakagami-gun, 903-0213, Okinawa, Okinawa, Japan