Comparison between a bulk-fill resin-based composite and three luting materials on the cementation of fiberglass-reinforced posts

Shimokawa Carlos Alberto Kenji,Carneiro Paula Mendes Acatauassú,Lobo Tamile Rocha da Silva,Braga Roberto Ruggiero,Turbino Míriam Lacalle,Matos Adriana Bona 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.3

Objectives This study verified the possibility of cementing fiberglass-reinforced posts using a flowable bulk-fill composite (BF), comparing its push-out bond strength and microhardness with these properties of 3 luting materials. Materials and Methods Sixty endodontically treated bovine roots were used. Posts were cemented using conventional dual-cured cement (CC); self-adhesive cement (SA); dual-cured composite (RC); and BF. Push-out bond strength (n = 10) and microhardness (n = 5) tests were performed after 1 week and 4 months of storage. Two-way repeated measures analysis of variance (ANOVA), 1-way ANOVA, t-test, and Tukey post-hoc tests were applied for the push-out bond strength and microhardness results; and Pearson correlation test was applied to verify the correlation between push-out bond strength and microhardness results (α = 0.05). Results BF presented higher push-out bond strength than CC and SA in the cervical third before aging (p < 0.01). No differences were found between push-out bond strength before and after aging for all the luting materials (p = 0.84). Regarding hardness, only SA presented higher values measured before than after aging (p < 0.01). RC and BF did not present 80% of the maximum hardness at the apical regions. A strong positive correlation was found between the luting materials' push-out bond strength and microhardness (p < 0.01, R2 = 0.7912). Conclusions The BF presented comparable or higher push-out bond strength and microhardness than the luting materials, which indicates that it could be used for cementing resin posts in situations where adequate light curing is possible. Objectives This study verified the possibility of cementing fiberglass-reinforced posts using a flowable bulk-fill composite (BF), comparing its push-out bond strength and microhardness with these properties of 3 luting materials. Materials and Methods Sixty endodontically treated bovine roots were used. Posts were cemented using conventional dual-cured cement (CC); self-adhesive cement (SA); dual-cured composite (RC); and BF. Push-out bond strength (n = 10) and microhardness (n = 5) tests were performed after 1 week and 4 months of storage. Two-way repeated measures analysis of variance (ANOVA), 1-way ANOVA, t-test, and Tukey post-hoc tests were applied for the push-out bond strength and microhardness results; and Pearson correlation test was applied to verify the correlation between push-out bond strength and microhardness results (α = 0.05). Results BF presented higher push-out bond strength than CC and SA in the cervical third before aging (p < 0.01). No differences were found between push-out bond strength before and after aging for all the luting materials (p = 0.84). Regarding hardness, only SA presented higher values measured before than after aging (p < 0.01). RC and BF did not present 80% of the maximum hardness at the apical regions. A strong positive correlation was found between the luting materials' push-out bond strength and microhardness (p < 0.01, R2 = 0.7912). Conclusions The BF presented comparable or higher push-out bond strength and microhardness than the luting materials, which indicates that it could be used for cementing resin posts in situations where adequate light curing is possible.

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.

Study on Non-Contacting Support of Thin Plate by Fluid Cushion Force ( Effect of Nozzle Angle on Flow Rate in Three Dimensional Model )

Y. Shimokawa,J. Shibata 대한기계학회 1994 KSME/JSME THERMAL and FLUID Engineering Conference Vol.1 No.1

EFFECTS OF ASYMMETRIC INLET NOZZLE GEOMETRY ON DUCTED DARRIEUS-TYPE HYDRO TURBINE

Kai SHIMOKAWA,Koutarou HIROWATARI,Daisuke MATSUSHITA,Satoshi WATANABE,Akinori FURUKAWA,Kusuo OKUMA 한국신재생에너지학회 2011 AFORE Vol.2011 No.-

Protein 2b of Cucumber mosaic virus strains IA and SD preferentially suppresses RDR6-dependent silencing pathway

Mayuko Shimokawa,Sayaka Hirai,Hiroaki Kodama 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.2

The 2b protein of Cucumber mosaic virus (CMV) subgroup IB strain IA (IA2b) suppresses the sense transgene-induced posttranscriptional gene silencing (S-PTGS) but not the inverted repeat-induced post-transcriptional gene silencing (IR-PTGS) of a tobacco microsome-localized α-linolenate synthase gene (NtFAD3). In contrast, the 2b protein of CMV subgroup IB strain SD (SD2b) has been reported to suppress IR-PTGS. We overexpressed the SD2b gene in tobacco, and this transgenic line was crossed with the transgenic plants showing S-PTGS and IR-PTGS of the NtFAD3 gene. The phenotype of offspring showed that SD2b inhibited S-PTGS but not IR-PTGS. Next, we determined the suppressor activity of IA2b and SD2b proteins in a transient IR-PTGS assay. The transient expression of firefly luciferase (LUC) gene was efficiently decreased by IR-PTGS. Co-infiltration of SD2b and IA2b gene partially suppressed IR-PTGS of the LUC gene in the wild-type plants; however, these 2b proteins did not suppress IR-PTGS in the RNA-dependent RNA polymerase6 (RDR6) knockdown plants. It has been reported that RDR6-dependent secondary small interfering RNA synthesis does not occur in the IR-PTGS, when targeting endogenous genes such as NtFAD3, but is efficiently induced in the IR-PTGS of the reporter transgenes. These results indicate that the SD2b and IA2b preferentially suppress the RDR6-dependent silencing pathway but do not suppress the RDR6-independent IR-PTGS pathway.

Review of Radiological Parameters, Imaging Characteristics, and Their Effect on Optimal Treatment Approaches and Surgical Outcomes for Cervical Ossification of the Posterior Longitudinal Ligament

Nobuyuki Shimokawa,Hidetoshi Sato,Hiroaki Matsumoto,Toshihiro Takami 대한척추신경외과학회 2019 Neurospine Vol.16 No.3

Determining the optimal surgical method for cervical ossification of the posterior longitudinal ligament (OPLL) is challenging. The surgical indication should be made based on not only radiological findings, but also the patient’s age, preoperative neurological findings, social background, activities of daily life, and the presence or absence of comorbid diseases. Anterior resection for OPLL with or without wide corpectomy and fusion, posterior decompression with or without relatively long fusion, or anterior and posterior combined surgery may be considered. When evaluating the clinical condition of patients with cervical OPLL before surgery, various radiological parameters should be carefully considered, including the number of spinal segments involved, the cervical alignment or tilt angle, the relationship between OPLL and the C2–7 line (termed the “K-line”), the occupying ratio of OPLL, and the involvement of dural ossification. The objective of this article is to review the radiological parameters in current use for deciding upon the optimal surgical strategy and for predicting surgical outcomes, focusing on cervical OPLL.

Electrodeposited Fe-Ni Films Prepared from a Tartaric-acid-based Bath

T. Shimokawa,T. Yanai,K. Takahashi,M. Nakano,H. Fukunaga,K. Suzuki 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.12

Recently, we reported a citric-acid-based plating bath is one of the hopeful plating baths forobtaining Fe-Ni films with good soft magnetic properties. In this report, hydroxylic acid of tartaricacid, which belongs to the same acid group at citric acid, was applied to prepare the films, and theeffects of tartaric acid on the magnetic and the structural properties were investigated. Although theoverall trend of the effects obtained for tartaric acid resembles our previous results for the citricacid-based bath, the cathode efficiency for the tartaric-acid-based bath shows a slightly highervalue as compared with that for the citric-acid-based bath. From these results, we conclude thatthe tartaric-acid-based bath is also an environmentally friendly plating bath.

Longevity Genes: Insights from Calorie Restriction and Genetic Longevity Models

Isao Shimokawa,Takuya Chiba,Haruyoshi Yamaza,Toshimitsu Komatsu 한국분자세포생물학회 2008 Molecules and cells Vol.26 No.5

In this review, we discuss the genes and the related signal pathways that regulate aging and longevity by reviewing recent findings of genetic longevity models in rodents in reference to findings with lower organisms. We also paid special attention to the genes and signals mediating the effects of calorie restriction (CR), a powerful intervention that slows the aging process and extends the lifespan in a range of organisms. An evolutionary view emphasizes the roles of nutrient-sensing and neuroendocrine adaptation to food shortage as the mechanisms underlying the effects of CR. Genetic and non-genetic interventions without CR suggest a role for single or combined hormonal signals that partly mediate the effect of CR. Longevity genes fall into two categories, genes relevant to nutrient-sensing systems and those associated with mitochondrial function or redox regulation. In mammals, disrupted or reduced growth hormone (GH)-insulin-like growth factor (IGF)-1 signaling robustly favors longevity. CR also suppresses the GH-IGF-1 axis, indicating the importance of this signal pathway. Surprisingly, there are very few longevity models to evaluate the enhanced anti-oxidative mechanism, while there is substantial evidence supporting the oxidative stress and damage theory of aging. Either increased or reduced mitochondrial function may extend the lifespan. The role of redox regulation and mitochondrial function in CR remains to be elucidated.

Nontrivial Ferrimagnetism of the Heisenberg Model on the Union Jack Strip Lattice

Tokuro Shimokawa,Hiroki Nakano 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3

We study the ground-state properties of the S = 1/2 antiferromagnetic Heisenberg model onthe Union Jack strip lattice by using the exact-diagonalization and density matrix renormalizationgroup methods. We confirm a region of a magnetization state intermediate between the N´eel-likespin liquid state and the conventional ferrimagnetic state of a Lieb-Mattis type. In the intermediatestate, we find that the spontaneous magnetization changes gradually with respect to the strength ofthe inner interaction. In addition, the local magnetization clearly shows an incommensurate modulationwith long-distance periodicity in the intermediate magnetization state. These characteristicbehaviors lead to the conclusion that the intermediate magnetization state is a non-Lieb-Mattisferrimagnetic one. We also discuss the relationship between the ground-state properties of theS = 1/2 antiferromagnetic Heisenberg model on the original Union Jack lattice and those on ourstrip lattice.

A Role for FoxO1 in the Anti-Aging Effect of Calorie Restriction

Isao Shimokawa 한국실험동물학회 2010 한국실험동물학회 학술발표대회 논문집 Vol.2010 No.2

Moderate restriction of food intake with essential nutrients, referred to as calorie restriction (CR), reduces morbidity and mortality in aging animals, compared with animals with abundant food supply. The FoxO transcription factors may be involved in the antiaging effect of calorie restriction (CR) in mammals. To test the hypothesis, we used FoxO1-knockout heterozygotic (HT) mice, in which the FoxO1 mRNA level was reduced by 50%, or less, of that in wild-type (WT) mouse tissues. The WT and HT mice were fed ad libitum (AL) or 30% CR diets from 12 weeks of age. Aging- and CR-related changes in body weight, food intake, blood glucose and insulin concentrations were similar between the WT and HT mice in the lifespan study. The response to oxidative stress, induced by intraperitoneal injection of 3-nitropropionic acid (3-NPA), was evaluated in the liver and hippocampus at 6 months of age. Several of the selected FoxO1-target genes for cell cycle arrest, DNA repair, apoptosis, and stress resistance, were up-regulated in the WT-CR tissues after 3-NPA injection, while the effect was mostly diminished in the HT-CR tissues. Of these gene products, we focused on the nuclear p21 protein level in the liver and confirmed its up-regulation only in the WT-CR mice in response to oxidative stress. The lifespan did not differ significantly between the WT and HT mice in AL or CR conditions. However, the antineoplastic effect of CR, as indicated by reduced incidence of tumors at death in the WT-CR mice, was mostly abrogated in the HT-CR mice. The present results suggest a role for FoxO1 in the antineoplastic effect of CR through the induction of genes responsible for protection against oxidative and genotoxic stress.