Observation of very large chiral domains in a liquid crystal phase formed by mixtures of achiral bent-core and rod molecules

Takanishi, Yoichi,Shin, Gyo Jic,Jung, Jin Chul,Choi, Suk-Won,Ishikawa, Ken,Watanabe, Junji,Takezoe, Hideo,Toledano, Pierre Royal Society of Chemistry 2005 Journal of materials chemistry Vol.15 No.37

<P>Experimental observations on the B<SUB>4</SUB> phase of liquid crystal mixtures formed from bent-core (P-8-O-PIMB) and rod (5CB) achiral molecules reveal the stabilization of the B<SUB>4</SUB> phase with an unusually large size of chiral domains. The phenomenon is interpreted as an intrinsic property of the B<SUB>4</SUB> phase when arising below the isotropic liquid (Iso); actually direct transition between Iso and B<SUB>4</SUB> phases occurs except for only very limited regions of pure P-8-O-PIMB and 5CB molecules. The phase diagram of the mixture shows the existence of a new phase, closely related to the B<SUB>4</SUB> phase.</P> <P>Graphic Abstract</P><P>Experimental observations of liquid crystal mixtures formed from bent-core (P8-OPIMB) and rod (5CB) achiral molecules reveal the stabilization of the B<SUB>4</SUB> phase with an unusually large size of chiral domains. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b507875j'> </P>

Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material Synthesis

Ryo Ageba,Yoichi Kadota,Takafumi Maeda,Norihito Takiguchi,Takeshi Morita,Mutsuso Ishikawa,Peter Bornmann,Tobias Hemsel 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.41

The hydrothermal method enables the production of high-quality piezoelectric materials. In this study, we propose to irradiate the reaction solutions with ultrasonic power during the hydrothermal method to obtain a shorter reaction time and a smooth film surface. A high-pressure reaction container for the ultrasonic transducer was newly developed, and the ultrasonically-assisted hydrothermal method was examined by using this container. The effect of ultrasonic assist on the synthesis of lead-zirconate-titanate (PZT) thin films and (K,Na)NbO3 powders was verified. Thicker PZT film, thickness around 10 µm, could be obtained in one process, and (K,Na)NbO3 powder was synthesized in half the previous reaction time.

Simultaneous Assimilation Model of Drifting Buoy and Altimetric Data for Ocean Surface Circulations

Awaji, Toshiyuki,Ishikawa, Yoichi,Akitomo, Kazunori 대한원격탐사학회 1996 International Symposium on Remote Sensing Vol.12 No.1

A simultaneous assimilation model of drifting buoy and altimetric data is proposed to determine the mean sea surface height(SSH) as well as the temporal evolution of the surface circulation on synoptic scales. The result shows that realistic buoy deployment (32 in a 40° square) ca.n effectively constrain the model variables; that is, both the absolute (mean plus time varying) velocity and SSH (interface depth) fields are significantly improved. Successive correction of the mean SSH is made with the simultaneous assimilation of drifting buoy and altimetric data. Consequently, a better correction of the mean SSH is obtained: The initial error of the mean SSH is reduced by approximately 40% after the 1-year experiment. These results clearly show that simultaneous assimilation of drifting buoy and altimetric data into the dynamical model is a very useful tool for improving the model's realism.

Experimental investigation of interlaminar mechanical properties on carbon fiber stitched CFRP laminates

Iwahori, Yutaka,Ishikawa, Takashi,Watanabe, Naoyuki,Ito, Akira,Hayashi, Yoichi,Sugimoto, Sunao The Korean Society for Composite Materials 2007 Advanced composite materials Vol.16 No.2

Experimental investigations of interlaminar mechanical properties for carbon fiber reinforced plastic (CFRP) laminates were carried out using aramid fiber ($Kevlar^{(R)}$-29 1000d) and carbon fiber (TR40-1K 612d, Mitsubishi Rayon) stitching. Various carbon fiber (CF) stitch densities were used to prepare a number of CF stitched CFRP laminates for double cantilever beam (DCB) tests. An insert tongue-type loading fixture, developed by the Japan Aerospace Exploration Agency (formerly the National Aerospace Laboratory of Japan), was also employed in the DCB test. Interlaminar tension tests were carried out under an out-of-plane directional loading using a single CF stitch thread in the CFRP laminates. The DCB test results clarified that the relationship between the volume fractions of the CF stitch thread ($V_{ft}$) and mode I critical energy release rate ($G_{Ic}$) showed a mostly linear function with a higher gradient than that of the $Kevlar^{(R)}$ stitched CFRP laminates. The CF stitched CFRP tension test results indicated that the consumption energy per unit area ($E_i$) was larger than that of $Kevlar^{(R)}$ stitched CFRP laminates.

Air-Sea Heat Flux Estimation by Ocean Data Assimilation Using Satellite and TOGA/TAO Buoy Data

Awaji, Toshiyuki,Ishikawa, Yoichi,Iida, Masatora,In, Teiji 대한원격탐사학회 1999 International Symposium on Remote Sensing Vol.15 No.1

A data assimilation system for a 1-dimensional mixed layer model has been constructed using the adjoint method. The classical adjoint method does not work well for the mixed layer variabilities due to the occurrence of spikes in the gradient of the cost function. To solve this problem, the two techniques of scaling the cost function and optimization in the frequency space are used. As a result, the heat flux can be reliably estimated with an accuracy of 8Wm^(-2) rms error in the identical twin experiments. We then applied this system to the tropical Pacific TOGA-TAO buoy data. The air-sea heat flux as well as the mixed layer variability were estimated in close approximation to the buoy data, particularly on time scales longer than the seasonal one.

Surgical Results of Patients with Myelopathy due to Ossification of the Ligamentum Flavum with Ossification of the Posterior Longitudinal Ligament or a Vertebral Fracture at the Same Level of the Thoracic Spine: A Retrospective Comparative Study

Yuji Kasukawa,Naohisa Miyakoshi,Michio Hongo,Yoshinori Ishikawa,Daisuke Kudo,Ryota Kimura,Yuichi Ono,Jumpei Iida,Chiaki Sato,Yoichi Shimada 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.5

Study Design: Retrospective and comparative study. Purpose: We assessed surgical treatment outcomes in patients with thoracic myelopathy due to ossification of the ligamentum flavum (OLF), and OLF combined with ossification of the posterior longitudinal ligament (OPLL) or vertebral fracture (VF) at the same level. Overview of Literature: OLF and OPLL cause severe thoracic myelopathy. Osteoporotic VF commonly occurs at the thoracolumbar junction. There have been no investigations of thoracic myelopathy due to OLF and VF. Methods: Forty patients were divided among three groups: the OLF group (n=23): myelopathy due to OLF, the OLF+OPLL group (n=12): myelopathy due to OLF and OPLL, and the OLF+VF group (n=5): myelopathy due to OLF and VF. We recorded OLF, OPLL, and VF sites and operative procedures. Each patient’s neurological status, according to the Japanese Orthopaedic Association (JOA) score, and walking ability were evaluated pre- and postoperatively. Results: Patients in the OLF+OPLL group were significantly younger than those in the other two groups. The preoperative JOA score was significantly lower in the OLF+VF than OLF group. The final JOA score was significantly lower in the OLF+VF than OLF and OLF+OPLL groups. The JOA score recovery rate was significantly lower in the OLF+VF than OLF group. Final walking ability was significantly worse in the OLF+OPLL and OLF+VF groups than in the OLF group and significantly worse in the OLF+VF than OLF+OPLL group. Conclusions: Thoracic myelopathy due to OLF+VF occurs primarily in older females, who also exhibit worse preoperative and postoperative neurological status, and worse walking ability, than patients with thoracic myelopathy due to OLF or OLF+OPLL.

Short-Term Results of Transforaminal Lumbar Interbody Fusion Using Pedicle Screw with Cortical Bone Trajectory Compared with Conventional Trajectory

Yuji Kasukawa,Naohisa Miyakoshi,Michio Hongo,Yoshinori Ishikawa,Daisuke Kudo,Yoichi Shimada 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.3

Study Design: Case-control study. Purpose: To evaluate clinical and radiological results of transforaminal lumbar interbody fusion (TLIF) performed with cortical bone trajectory (CBT) pedicle screw insertion with those of TLIF using ‘conventional’ or percutaneous pedicle screw insertion. Overview of Literature: CBT is a new trajectory for pedicle screw insertion in the lumbar spine; clinical and radiological results of TLIF using pedicle screws inserted with CBT are unclear. Methods: In total, 26 patients (11 males, 15 females) were enrolled in this retrospective study and divided into three groups: TLIF with pedicle screw insertion by conventional minimally invasive methods via the Wiltse approach (M-TLIF, n=10), TLIF with percutaneous pedicle screw insertion (P-TLIF, n=6), and TLIF with pedicle screw insertion with CBT (CBT-TLIF, n=10). Surgical results and preand postoperative radiological findings were evaluated and compared. Results: Intraoperative blood loss was significantly less with CBT-TLIF (p =0.03) than with M-TLIF. Postoperative lordotic angles did not differ significantly among the three groups. Complete fusions were obtained in 10 of 12 levels (83%) with M-TLIF, in seven levels (100%) with P-TLIF, and in 10 of 11 levels (91%) with CBT-TLIF. On postoperative computed tomography, correct positioning was seen in 84.1% of M-TLIF screws, 88.5% of P-TLIF screws, and 90% of CBT-TLIF screws. Conclusions: CBT-TLIF resulted in less blood loss and a shorter operative duration than M-TLIF or P-TLIF. Postoperative rates of bone union, maintenance of lordotic angles, and accuracy of pedicle screw positions were similar among the three groups.

Tidal Transport through the Tsugaru Strait - Part I: Characteristics of the Major Tidal Flow and its Residual Current

Quang-Hung Luu,Kosuke Ito,Yoichi Ishikawa,Toshiyuki Awaji 한국해양과학기술원 2011 Ocean science journal Vol.46 No.4

The potential role of the tide-induced time-mean flow (the tidal residual current) in determining transport through the Tsugaru Strait (located between the East/Japan Sea and the North Pacific) is investigated using a high-resolution numerical barotropic model. The calculated K_1, O_1, M_2, and S_2 tidal fields agree well with available observational records derived from both tide gauge and current meter measurements in the strait and the adjacent seas. The tidal residual current speed reaches 0.3 ms^(-1) in two narrow “neck” areas where topographic sills are located. This result suggests that tides should be taken into account in estimating the long-term water mass and nutrient transport through narrow regions between the East/Japan Sea and the North Pacific. An interesting aspect of the tidal residual current field is the prediction of several active eddy zones in which sequences of eddy triplets develop in the vicinity of capes. Our vorticity analysis reveals that the interplay of topographic effects arising from both the headland and the sill around capes plays a critical role in the formation of these triple eddy patterns.

Age-Related Prevalence of Periodontoid Calcification and Its Associations with Acute Cervical Pain

Takashi Kobayashi,Naohisa Miyakoshi,Norikazu Konno,Yoshinori Ishikawa,Hideaki Noguchi,Yoichi Shimada 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.6

Study Design: Prospective study. Purpose: To assess the prevalence of periodontoid calcification and its associations with acute cervical pain. Overview of Literature: Calcium pyrophosphate dihydrate (CPPD) deposition disease is a common rheumatological disorder that occurs especially in elderly patients. Although CPPD crystals induce acute arthritis, these crystals are not usually symptomatic. Calcification surrounding the odontoid process (periodontoid calcification) has been reported to induce inflammation, resulting in acute neck pain. This disease is called crowned dens syndrome. Whether calcification induces inflammation or whether the crystals are symptomatic remains unclear. Methods: The prevalence of periodontoid calcification at the atlas transverse ligament was examined by computed tomography of the upper cervical spine in patients suspected of brain disease but no cervical pain (control group, n=296), patients with pseudogout of the peripheral joints but no cervical pain (arthritis group, n=41), and patients with acute neck pain (neck pain group, n=22). Next, the correlation between the prevalence of periodontoid calcification and symptoms was analyzed. Results: In the control group, 40 patients (13.5%) showed periodontoid calcification with no significant difference in the prevalence with gender. The prevalence of calcification increased significantly with age (p =0.002). In the arthritis group, 26 patients (63.4%) reported periodontoid calcification. In the neck pain group, 14 patients (63.6%) reported periodontoid calcification. Multiple logistic regression analysis by age and group revealed that higher age, inclusion in the arthritis group, and inclusion in the neck pain group significantly affected the prevalence of calcification. Conclusions: Our results cumulatively suggest that periodontoid calcification is an aging-related reaction and that calcification per se does not always cause neck pain. Periodontoid calcification was observed more frequently in patients with pseudogout of the peripheral joints and in those with acute neck pain than in asymptomatic control patients.

Impact of appendicular and trunk skeletal muscle mass and back extensor strength on sagittal spinal alignment in Japanese women without vertebral fracture

Daisuke Kudo,Naohisa Miyakoshi,Michio Hongo,Yuji Kasukawa,Yoshinori Ishikawa,Takashi Mizutani,Yoichi Mizutani,Yoichi Shimada 대한골다공증학회 2021 Osteoporosis and Sarcopenia Vol.7 No.1

Objectives: Progressive and generalized loss of skeletal muscle mass (SMM) and strength are characteristics of sarcopenia. However, the impact of appendicular and trunk SMM and back extensor strength (BES) on spinal sagittal alignment remains unclear. Herein, we investigate the relationship between these factors and spinal sagittal alignment. Methods: In total, 202 women without vertebral fractures (median age, 66.9 years; interquartile range, 61.4e71.9 years) were analyzed at an orthopedic outpatient clinic. Pelvic incidence (PI), lumbar lordosis (LL), sagittal vertical axis (SVA), and pelvic tilt (PT) were measured on whole spine radiographs. Body mass index (BMI), appendicular and trunk relative SMM index, and BES were also evaluated. These measurements were compared between spinal sagittal alignment groups using the ManneWhitney U test. Finally, the factors contributing to abnormal alignment were analyzed using multiple logistic regression analysis. Results: BES was significantly lower in all abnormal sagittal alignment groups, as defined by PI-LL ( 10), SVA (4 cm), and PT (20) (all P < 0.001). On multivariate analysis, BES was a contributing factor for abnormal PI-LL (P < 0.001), SVA (P ¼ 0.001), and PT (P < 0.001). Conversely, a decrease in appendicular and trunk relative SMM index did not statistically affect abnormal spinal sagittal alignment. Conclusions: BES was associated with changes in spinal sagittal alignment; however, SMM, which is often used for diagnosing sarcopenia, did not affect spinal sagittal alignment.