Non-Specific Binding of Phytochemicals to Biological Proteins May Play Significant Role in Their Physiological Functions

Akira Murakami,Kohta Ohnishi 한국식품영양과학회 2011 한국식품영양과학회 학술대회발표집 Vol.2011 No.10

Postoperative Loss of Lumbar Lordosis Affects Clinical Outcomes in Patients with Pseudoarthrosis after Posterior Lumbar Interbody Fusion Using Cortical Bone Trajectory Screw Fixation

Yamagishi Akira,Sakaura Hironobu,Ishii Masayoshi,Ohnishi Atsunori,Ohwada Tetsuo 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.3

Study Design: Retrospective cohort study. Purpose: This study aimed to investigate relationships between clinical outcomes and radiographic parameters in patients with pseudoarthrosis after posterior lumbar interbody fusion (PLIF). Overview of Literature: In some patients with pseudoarthrosis after PLIF, clinical symptoms improve following surgery, although pseudoarthrosis can often be one of the complications. However, there are no previous reports describing differences between patients with pseudoarthrosis after PLIF who have obtained better clinical outcomes and those who have not. Methods: Twenty-seven patients who were diagnosed with pseudoarthrosis after single-level PLIF with cortical bone trajectory screw fixation (CBT-PLIF) were enrolled in this study. They were divided into two groups based on mean improvement of 22 points on the Oswestry Disability Index (ODI) at the 2-year follow-up. Group G consisted of 15 patients who showed improvement on the ODI of ≥22 points, and group P consisted of the residual 12 patients. Radiographic parameters, percentage of slip, lumbar lordosis (LL), segmental lordosis, segmental range of motion, screw loosening, and subsidence were compared between the two groups. Results: There were no significant differences between the two groups on radiographic parameters except for postoperative changes in LL. Although surgery-induced changes in LL showed no significant difference between the two groups, changes in LL from before surgery to 2-year follow-up and during postoperative 2-year follow-up were significantly better in group G (mean change of LL: +3.5° and +5.1°, respectively) compared to group P (mean change of LL: −4.6° and −0.5°, respectively) (p<0.01 and 0.05, respectively). Conclusions: Patients with greater improvement in ODI gained LL over the 2-year follow-up, whereas patients with less improvement in ODI lost LL during the 2-year follow-up. These results indicate that there is a significant correlation between clinical outcomes and LL even in patients with pseudoarthrosis after single-level CBT-PLIF.

Early Fusion Status after Posterior Lumbar Interbody Fusion with Cortical Bone Trajectory Screw Fixation: A Comparison of Titanium-Coated Polyetheretherketone Cages and Carbon Polyetheretherketone Cages

Hironobu Sakaura,Atsunori Ohnishi,Akira Yamagishi,Tetsuo Ohwada 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.2

Study Design: Retrospective cohort study. Purpose: We recently reported that when compared to posterior lumbar interbody fusion (PLIF) using traditional pedicle screw fixation, PLIF with cortical bone trajectory screw fixation (CBT-PLIF) provided favorable clinical outcomes and reduced the incidence of symptomatic adjacent segment pathology, but resulted in relatively lower fusion rates. Since titanium-coated polyetheretherketone (PEEK) cages (TP) could improve and accelerate fusion status after CBT-PLIF, early fusion status was compared between CBT-PLIF using TP and carbon PEEK cages (CP). Overview of Literature: A systematic review demonstrated that clinical studies at this early stage show similar fusion rates for TP compared to PEEK cages. Methods: We studied 36 consecutive patients undergoing CBT-PLIF with TP (TP group) and 92 undergoing CBT-PLIF with CP (CP group). On multiplanar reconstruction computed tomography (MPR-CT) at 6 months postoperatively, vertebral endplate cysts (cyst signs) were evaluated and classified as diffuse or local cysts. Early fusion status was assessed by dynamic plain radiographs and MPR-CT at 1 year postoperatively. Results: The incidences of cyst signs, diffuse cysts, and early fusion rate in the TP and CP groups were 38.9% and 66.3% (p<0.01), 16.7% and 32.6% (p=0.07), and 83.3% and 79.3% (p>0.05), respectively. Combining the two groups, 22 of 36 patients with diffuse cysts had nonunion at 1-year follow-up, compared to only three of 92 patients with local cysts or without cyst signs (p<0.01). Conclusions: Despite having fewer patients with endplate cysts at 6 months (a known risk factor for nonunion), the TP group had the same fusion rate as the CP group at 1-year follow-up. Thus, TP did not accelerate the fusion process after CBT-PLIF.

Compensatory Pelvic Retro-Rotation Associated with a Decreased Quality of Life in Patients with Normal Sagittal Balance

Shimokawa Tetsuya,Miyamoto Kei,Hioki Akira,Masuda Takahiro,Fushimi Kazunari,Ogawa Hiroyasu,Ohnishi Kazuichiro,Akiyama Haruhiko 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.2

Study Design: Cross-sectional observational study. Purpose: To examine whether pelvic rotation as a compensatory mechanism for sagittal imbalance is related to quality of life (QOL). Overview of Literature: Poor sagittal alignment is associated with compensatory pelvic retroversion and decreased QOL. Whether the compensatory pelvic tilt (PT) influences QOL is unclear. Methods: Overall, 134 subjects aged ≥20 years with lower back pain were included (104 females; mean age, 70±9.8 years). Sagittal vertical alignment (SVA) and PT were analyzed radiographically. Patients were stratified into three groups based on SVA values: good alignment (group G), intermediate alignment (group I), and poor sagittal alignment (group P). Patients in group I were further categorized into two groups: low PT and high PT. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) was used for clinical assessment, and the scores were compared between groups. Results: As SVA increased, PT and lumbar lordosis (LL) increased and decreased, respectively. PT and LL differed significantly between groups G and P (p<0.01 for each comparison). Within group I, there was no significant difference in SVA between the high PT and low PT groups, suggesting that the high PT group had acquired a compensated sagittal balance. Importantly, all domains in the JOABPEQ (except for lower back pain) were significantly lower in the high PT group than in the low PT group (p<0.05 for every comparison). Conclusions: This study showed that focusing solely on SVA as a single indicator can cause important losses in QOL to be overlooked in patients with lumbar disorders. Although pelvic retroversion can compensate for sagittal balance, it is associated with a significant decrease in QOL. To improve the assessment of patients with lumbar disorders, PT should be considered besides SVA.

Atomic-Scale Structure and Non-Stoichiometry of Meteoritic Hibonite: Understanding the Formation of the First Solar System Solids

Jangmi Han,Lindsay P. Keller,Ichiro Ohnishi,Akira Yasuhara 대한지질학회 2021 대한지질학회 학술대회 Vol.2021 No.10

Refractory Ca-Al-rich inclusions (CAIs) in primitive meteorites consist of complex assemblages of high-temperature minerals [1], which are predicted to form by gas-solid condensation reactions in the early solar nebula [2]. Their mineralogy and petrography thus provide a window into events that occurred at the birth of our Solar System ~4.567 billion years ago [3]. Hibonite (CaAl12O19) is a common refractory mineral in CAIs [1], which is predicted as the second phase, after corundum, to condense from a cooling gas of solar composition [2]. Transmission electron microscope (TEM) studies have identified enigmatic planar defects in different occurrences of hibonite in the Allende meteorite that give rise to strong streaking along c* in electron diffraction patterns. Atomic resolution high-angle annular dark-field (HAADF) imaging and energy dispersive X-ray (EDX) analyses were used to determine the nature and origin of these planar features [4]. HAADF images of hibonite grains reveal lamellar intergrowths of common 1.6 nm spacing, and less commonly 2.0 nm and 2.5 nm spacings, interspersed in stoichiometric hibonite showing 1.1 nm (002) spacing. Stoichiometric hibonite consists of alternating Ca-containing (“R”) and spinel-structured (“S”) blocks stacked in a sequence RS [5]. In contrast, the 1.6 nm layers result from a doubled S block such that the stacking sequence is RSS, while in the widest defect observed, the stacking sequence is RSSSS. These intergrowths are epitaxial and have coherent, low-strain boundaries with the host hibonite. In addition, atomic resolution EDX maps of hibonite grains in the Allende CAI show that Mg is highly concentrated, but Ti is absent, in the planar defects where wider S blocks show Al-rich compositions compared to stoichiometric MgAl₂O₄ spinel. Therefore, Mg likely played the major role in the formation and metastability of planar defects in hibonite. The formation of planar defects in hibonite occurred during high-temperature condensation or melting/crystallization processes in the early solar nebula. The occurrence of non-stoichiometric hibonite intergrown with Al-rich spinel in the Allende CAI deviates from the mineral formation sequence predicted from equilibrium condensation models, suggesting that these phases formed metastably in place of thermodynamic equilibrium Ca-Al-oxide assemblages. Therefore, our atomic resolution TEM observations signify non-equilibrium, kinetic-controlled crystal growth during high-temperature formation of refractory solids in the early solar nebula [4,6].

진공환경에서 다공성 소재의 열확산도 측정 시스템

공철원(Cheol-Won Kong),남기원(Gi-Won Nam),이영무(Yeong-Moo Yi),Akira Ohnishi 한국항공우주연구원 2011 항공우주기술 Vol.10 No.1

다공성 소재의 열 확산도 측정 시스템을 개발하였다. 열확산도를 측정하는 다양한 시스템이 있지만 다공성 소재의 열확산도를 측정하는 것은 기존의 시스템으로는 어렵다. 본 논문에서는 주기가열법을 이용한 열확산도 측정시스템 및 장비의 검증에 대하여 정리하였다. 주기가열법을 검증하기 위해서 사용한 표준시편은 세라믹 소재를 사용하였다. 그 결과 표준값과 측정값이 일치함을 보였다. 다공성 소재 적용을 위하여 검증한 시편은 폴리스티렌폼이었다. 진공에서 열확산도 값도 측정하였는데, 진공에서 열확산도는 대기조건과 비교하여 63% 감소함을 보였다. 두 결과 모두 측정값과 표준값은 10% 오차 범위 이내에 있었다. A system of measurement for the thermal diffusivity of porous materials was developed. Although there are several measurement systems for thermal diffusivity, it is typically difficult to measure the thermal diffusivity of porous materials. This paper presents a measurement system for thermal diffusivity that utilizes a cyclic heating method along with the verification of the measured device. To verify the cyclic heating method, the available reference data of aceramic specimen was utilized. To apply the system to an actual porous material, polystyrene foam was tested. The thermal diffusivity of the polystyrene foam under vacuum was reduced by 63%. The measured values from both tests were in good agreement with the reference values, as they were within 10% of these values.

주기가열법을 이용한 탄소/에폭시 및 다공성 단열재의 진공 열확산도 측정

남기원 ( Gi Won Nam ),공철원 ( Cheol Won Kong ),이영무 ( Yeong Moo Yi ),( Akira Ohnishi ) 한국복합재료학회 2007 Composites research Vol.20 No.5