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Study design: A retrospective study. Objective: The aim of this study was to compare clinical and radiological outcomes of the anterior cervical discectomy and fusion (ACDF) with a novel zero-profile variable-angle (Zero-P VA) spacer and a traditional poly-ether-ether-ketone (PEEK) cage and plate system in cases pertaining to cervical radiculopathy/myelopathy. Summary of background data: There are two conventional types of ACDF procedures aimed at treating symptomatic cervical spondylosis. The first one involves an uninstrumented "stand-alone" approach utilizing bone graft/cage, while the second incorporates bone graft/cage in conjunction with a front plate positioned before the vertebral bodies. Both procedures have their own inherent advantages and disadvantages. The Zero-P VA spacer, however, represents a unique synthesis by amalgamating the advantages of both traditionally typical procedures. Notably, this spacer can potentially circumvent the issue related to prevertebral soft-tissue disturbance and reduce the occurrence of dysphagia. Methods: Using our surgical database, the authors systematically conducted a retrospective analysis encompassing all patients who underwent single-level ACDF between January 2018 and January 2019, with a minimum two-year follow-up. Patients either received a Zero-P VA implant or PEEK cage coupled with plating. The Japanese Orthopedic Association (JOA) score and Visual Analogue Scale (VAS) for arm and neck pain were documented. Dysphagia was evaluated using the Eating Assessment Tool-10 (ETA-10). Additional parameters such as cervical alignment, fusion rate and the incidence of postoperative complications were assessed. Results: According to the outcomes of the statistical analysis, there was no substantial disparity that emerged in the advancements observed in the JOA and VAS metrics between the two study cohorts. Noteworthy, however, the ETA-10 scores were statistically significantly reduced in the Zero-P VA group compared to the cage and plating group (p < 0.05). At the final follow-up, there were no statistically significant differences in the height of the operated segment, Cobb angle of the fused segment, C2–C7 Cobb angle and fusion rate between the two groups (p > 0.05). However, postoperative complications were slightly lower in patients with the Zero-P VA group (7.69%) as compared to the cage and plating group (16.67%). Conclusion: The clinical outcomes observed with the Zero-P VA spacer used for single-level ACDF were found to be satisfactory. The performance of this device is comparable or even superior to the traditional cage and plating method in preventing postoperative dysphagia and mitigating potential complications associated with the use of a plate. [ABSTRACT FROM AUTHOR]

Background: The safety and feasibility of using 1-month dual antiplatelet therapy (DAPT) followed by P2Y 12 inhibitor monotherapy for patients after percutaneous coronary intervention (PCI) with thin-strut biodegradable polymer drug-eluting stents (BP-DES) in daily clinical practice remain uncertain., Methods and results: The REIWA region-wide registry is a prospective study conducted in 1 PCI center and 9 local hospitals in northern Japan. A total of 1,202 patients who successfully underwent final PCI using BP-DES (Synergy: n=400; Ultimaster: n=401; Orsiro: n=401), were enrolled in the registry, and received 1-month DAPT followed by P2Y 12 inhibitor (prasugrel 3.75 mg/day or clopidogrel 75 mg/day) monotherapy. The primary endpoint was a composite of cardiovascular and bleeding events at 12 months, including cardiovascular death, myocardial infarction (MI), definite stent thrombosis (ST), ischemic or hemorrhagic stroke, and Thrombolysis in Myocardial Infarction (TIMI) major or minor bleeding. Based on the results of a previous study, we set the performance goal at 5.0%. Over the 1-year follow-up, the primary endpoint occurred in 3.08% of patients, which was lower than the predefined performance goal (P non-inferiority <0.0001). Notably, definite ST occurred in only 1 patient (0.08%) within 1 year (at 258 days). No differences were observed in the primary endpoint between stent types., Conclusions: The REIWA region-wide registry suggests that 1-month DAPT followed by P2Y 12 inhibitor monotherapy is safe and feasible for Japanese patients with BP-DES.

In this study, experiments pertaining to direct current (DC) interruptions are performed in an arc‐quenching chamber filled with silica sand. First, the arc column resistance is measured during DC arc‐quenching to demonstrate the elementary aspects of the arc in the silica‐sand‐filled space. Subsequently, an arrangement comprising a polymer cylinder between electrodes in the silica‐sand‐filled space is proposed to increase the arc column resistance during DC arc‐quenching. A polymethyl methacrylate (PMMA) cylinder is used in the experiments. Measurement results indicate that the arrangement of the PMMA cylinder causes the arc column resistance to increase approximately twofold in comparison with the no‐PMMA cylinder arrangement. Finally, the effect of increasing the arc column resistance is discussed in terms of PMMA and silica vapor. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

While plastics are classified by size as microplastics (<5 mm), mesoplastics (5-25 mm), and macroplastics (>25 mm), research in rivers has centered on microplastics, followed by macroplastics, with limited research on mesoplastics (research gap). This study aims to clarify the concentration, shape, and polymer composition of microplastics and mesoplastics in Japanese river water. We conducted field surveys for microplastics and mesoplastics in 147 rivers and at 185 measurement stations. The novelty of this study is in the use of a large number of field data to minimize the effect of the spatial difference in the microplastics and mesoplastics on the data analysis. Microplastics and mesoplastics were found at 183 (99 %) and 136 (74 %) stations, respectively. The difference between the concentration of microplastics and mesoplastics increased significantly with the increase in the concentration of microplastics, showing that the concentration of both microplastics and mesoplastics should be monitored to prevent an underestimation of plastic pollution in rivers with the appropriate sampling. A 2-stage size classification with microplastics (<5 mm) and macroplastics (>5 mm) is not suitable because the mesoplastics may be substantially overlooked. The regression slopes between microplastics and mesoplastics concentrations significant decrease in variance with increasing data number, suggesting the necessity of the large number of samples used in this study. The predominant shapes and polymer types of microplastics and mesoplastics were found to be fragment and fiber and polyethylene and polyethylene terephthalate (PET), respectively, which were affected appreciably by many fiber clusters. The fiber and PET ratios were dominant at stations with small population densities and urban ratios and can be attributed to atmospheric deposition and the underdeveloped rate of wastewater treatment plants (WWTPs). Therefore, it is necessary to monitor the dynamics and fate of fiber clusters inside and outside the basin., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yasuo NIhei reports financial support was provided by the Environmental Restoration, Conservation Agency of Japan. Tomoya Kataoka reports financial support was provided by New Energy and Industrial Technology Development Organization. Tomoya Kataoka reports financial support was provided by Government of Japan Ministry of Education Culture Sports Science and Technology., (Copyright © 2023. Published by Elsevier Ltd.)

The synthesis and optoelectronic functions of a germole-containing π-conjugated polymer prepared by the reaction of a lithiated polymer precursor are described. A regioregular organometallic polymer having 1,4-dilithio-1,3-butadiene and 9,9-dioctylfluorene-2,7-diyl units was generated by the reaction of a tellurophene-containing polymer having a number-average molecular weight (Mn) and molecular weight distribution (Mw/Mn) of 5900 and 1.9, respectively, with n-butyllithium (2.4 equiv) at −78 to −60 °C for 3 h. The prepared lithiated polymer was reacted with dimethylgermanium dichloride (1.5 equiv) at −60 °C to ambient temperature for 12 h in tetrahydrofuran to produce a π-conjugated polymer possessing 1,1-dimethylgermole-2,5-diyl units in 76% yield (Mn = 4400 and Mw/Mn = 1.7). The absorption maximum and onset of the obtained polymer were observed at 465 and 535 nm, respectively, in the UV-vis spectrum, from which the optical band gap of the polymer was estimated to be 2.31 eV. In the photoluminescence spectrum, the obtained polymer exhibits green fluorescence with an emission maximum of 547 nm and a quantum yield of 0.04. The chemical interaction of the dimethylgermole-containing π-conjugated polymer with fluoride was also examined in terms of the changes observed in the UV-vis absorption spectra. Organic electronics: Adding germanium into the mix A method for synthesizing a unique polymer with great potential for optoelectronic applications has been developed by researchers in Japan. Flexible and wearable optoelectronic devices are made possible by polymer materials that emit light when an electrical current is passed through them. Previous theoretical calculations have indicated that incorporating a molecular ring with a germanium atom, known as a germole, into a polymer can help optimize its electronic and optical properties. However, such a material has proven difficult to synthesize and characterize. Ikuyoshi Tomita and colleagues from the Tokyo Institute of Technology established a synthetic route for producing a germole-containing polymer. The team showed that their material luminesced in the green part of the visible spectrum, indicating its potential for organic light-emitting diodes and organic solar cells. A germole-containing π-conjugated polymer is prepared from the corresponding tellurophene-containing polymer by its Te–Li exchange reaction using n-butyllithium followed by the reaction with dimethylgermanium dichloride. The low-lying LUMO energy level of the germole-containing π-conjugated polymer is also described. [ABSTRACT FROM AUTHOR]

In this paper, ablation polymer was studied to improve the thermal interrupting performance of an SF6 gas circuit breaker. One kind of polymer was used as the ablation polymer on the basis of the specific constraint conditions for SF6 gas circuit breakers, such as not including hydrogen, and its ablation characteristics were investigated. Furthermore, the dominant factor of that polymer ablation was discussed by comparing ablated mass characteristics between the ablation polymer and polytetrafluoroethylene, which is widely used as the nozzle material of an SF6 gas circuit breaker. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Polyethylene (PE) and polyethylene terephthalate (PET) are among the most abundant plastics polluting the oceans. However, their environmental fate depends on how they have been weathered. Due to its unique geography, the Sea of Japan is a pollution hotspot where plastics accumulate. In this study, the structures of plastics, having drifted into the Sea of Japan coastline environment, were analyzed with a particular focus on examining polymer crystallization and carbonyl formation; two factors which influence microplastic formation and the adsorption of contaminants onto plastic surfaces. PE in the coastal environment did not show evidence of crystallization, although carbonyl formation did increase. By contrast, PET bottles were shown to not be uniform in structure, with unaged bottles being less crystalline in the neck component compared to the body. Because of this difference, in environmental PET bottles, it was the bottle neck that showed increases in crystallization and carbonyl group formation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The impact of microplastics (MPs, plastic particles ≤5 mm) on ecosystems is of great concern. Road surfaces represent a significant source of MPs where plastic fragments are physically and chemically reduced to MPs. However, the literature lacks information on fragmentation tendencies below 11 μm. This study aimed to characterize the occurrence of MPs in road dust in different size fractions down to 1.1 μm. Road dust was collected at five sites near a major road in Kusatsu city, Japan, and partitioned by size into 13 fractions (1.1-850 μm). The coarser fractions accounted for a greater proportion of the dust. The percentage of organic matter, determined by loss on ignition, increased as the fractions became finer. Pyrolysis-gas chromatography-mass spectrometry was used to quantify 12 types of polymers in each fraction. The dust was found to contain nine types of MP, namely, polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polystyrene (PS), styrene/butadiene rubber (SBR), acrylonitrile/butadiene/styrene resin (ABS), polycarbonate (PC), polymethylmethacrylate (PMMA), and polyamide 66 (PA66). The total MP concentration in road dust particles by particle size fraction (concentration f ) began to increase from the 125-250 μm fraction and remained elevated in finer fractions down to 1.1 μm, indicating that MPs in the road dust micronized to at least 1.1 μm. However, for individual polymer types, the tendency for concentration f to increase or decrease with particle size fraction varied: the concentration f of some polymers, such as PE and PVC, remained elevated in fractions down to 1.1 μm; the concentration f of SBR, a rubber-MP, showed a stable or decreasing trend in fractions of 7.0-11 μm and finer. Particles of PE, PVC, and some other plastics might become increasingly finer, even down to 1.1 μm. Further research is needed to understand the comminution limits of these polymers under pertinent environmental conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Marine debris comprising single-use plastic products (SUPs) is ubiquitous in Asian coastal waters, but there is little information on the types of polymers and the concentrations of plastic additives such waste products contain. In this study, 413 SUPs randomly collected from 4 Asian countries between 2020 and 2021 were analyzed to obtain specific polymer and organic additive profiles. Polyethylene (PE), coupled with external polymers, was prominent in the inside of the SUPs, whereas polypropylene (PP) and polyethylene terephthalate (PET) were prevalent in both the insides and outsides of the SUPs. The use of different polymers in the insides and outsides of PE SUPs implies specific and complicated recycling systems are required to maintain the purity of the products. Phthalate plasticizers including dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), and the antioxidant butylated hydroxytoluene (BHT) were prevalent in the SUPs (n = 68). High concentrations of DEHP were detected in PE bags from Myanmar (820,000 ng/g) and Indonesia (420,000 ng/g), which were an order of magnitude greater than the concentrations in PE bags collected in Japan. SUPs containing high concentrations of organic additives may be the primary source of harmful chemicals in the environment, and should be responsible for their ubiquitous distribution in ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Postoperative adhesions are the major cause of postoperative complications including intestinal obstruction, infertility, and chronic pelvic pain. In order to reduce postoperative adhesions, Terumo Corporation (Tokyo, Japan) has developed an adhesion barrier system (TCD-11091) which is easy to use at the treatment site in various surgical procedures including laparoscopic surgeries. We conducted a prospective randomized single-blind study in patients who underwent laparotomy with ileostomy.Methods and Results: One hundred twenty-six patients were randomly assigned to TCD-11091 group (n = 62) or non-treatment group (n = 62). Patient backgrounds were similar between the groups. At the time of ileostomy closure (the second-look surgery), the observation was performed on 55 in the TCD-11091 group and 43 in the control group. The incidence of adhesions observed at the second-look surgery was significantly lower in the TCD-11091 group (52.7 versus 90.7%; p < 0.001). For the secondary endpoints, the incidence of wide extent adhesions (grade 2 or higher) was significantly reduced (38.2 versus 79.1%; p < 0.001). Regarding the severity of adhesions, the incidence of grade 2 or higher adhesions was also significantly lower in the TCD-11091 group (47.3 versus 88.4%; p < 0.001). No differences in the incidence of adverse events were found between the TCD-11091 group and the non-treatment group (85.2 versus 75.4%; p = 0.225).Conclusions: Use of TCD-11091 was safe and associated with significantly lower incidence of adhesion and severity of adhesions compared with non-treatment procedure. [ABSTRACT FROM AUTHOR]

Treatment planning systems that use the Monte Carlo algorithm can calculate the dose to the medium (D m ) in non-water-equivalent tissues such as bones. However, D m cannot be verified using actual measurements; therefore, it is necessary to develop tissue-equivalent dosimeters. In this study, we developed a bone-equivalent polymer gel dosimeter (BPGD) that can measure the dose absorbed by the bone and investigated its sensitivity. The BPGDs were prepared by adding 3.0 mol of calcium hydrogen phosphate dihydrate as a component of bone to an improved dose-sensitive polyacrylamide gelatin and tetrakis hydroxymethyl phosphonium chloride (iPAGAT). One day after preparation, the BPGDs were irradiated with a field size of 15 × 15 cm 2 using a 10 MV X-ray beam to evaluate the dose sensitivity, dose-rate dependence, and dose-integration dependence. One day after dose exposure, the BPGDs were scanned using a 0.4 T MRI APERTO Eterna (Hitachi, Tokyo, Japan) to obtain R 2 values. The difference between the R 2 values of 6 Gy and 0 Gy was up to 5 s -1 , and the R 2 curve plateaued in the high-dose region. Moreover, the BPGD did not depend on the integration of the dose and dose rates. Therefore, the BPGDs that we developed can determine the radiation dose to bones., (© 2023. The Author(s), under exclusive licence to Japanese Society of Radiological Technology and Japan Society of Medical Physics.)

Background: P2Y12 inhibitor monotherapy without aspirin immediately after percutaneous coronary intervention (PCI) has not been tested in East Asian patients, so in this study we aimed to assess the safety and feasibility of reduced dose (3.75 mg/day) prasugrel monotherapy in Japanese patients presenting with chronic coronary syndrome (CCS)., Methods and results: ASET-JAPAN is a prospective, multicenter, single-arm pilot study that completed enrolment of 206 patients from 12 Japanese centers in September 2022. Patients with native de-novo coronary lesions and a SYNTAX score <23 were treated exclusively with biodegradable-polymer platinum-chromium everolimus-eluting stent(s). Patients were loaded with standard dual antiplatelet therapy (DAPT) and following successful PCI and optimal stent deployment, they received low-dose prasugrel (3.75 mg/day) monotherapy for 3 months. The primary ischemic endpoint was a composite of cardiac death, spontaneous target-vessel myocardial infarction, or definite stent thrombosis. The primary bleeding endpoint was Bleeding Academic Research Consortium (BARC) type 3 or 5. At 3-month follow-up, there were no primary bleeding or ischemic events, or any stent thrombosis., Conclusions: This pilot study showed the safety and feasibility of prasugrel monotherapy in selected low-risk Japanese patients with CCS. This "aspirin-free" strategy may be a safe alternative to traditional DAPT following PCI.

Marine plastic pollution has highlighted the need to address the disposal of plastic materials used in agricultural fields and prevent their runoff. To assess the status of microplastics derived from polymer-coated fertilizers (microcapsules), we investigated their seasonal and daily variations in a small agricultural river in Ishikawa Prefecture, Japan, throughout the irrigation period of April to October 2021 and 2022. We also investigated the relationship between microcapsule concentration and water quality. The mean microcapsule concentration over the study period ranged from 0.0 to 783.2 mg/m 3 (median 18.8 mg/m 3 ) and was positively correlated with total litter weight, but it was not correlated with common water quality parameters such as total nitrogen or suspended solids. Concentrations of microcapsules in river water showed distinct seasonal variations, being particularly high in late April and late May (median 55.5 mg/m 3 in 2021, 62.6 mg/m 3 in 2022) and almost undetectable thereafter. The timing of the increase in concentration coincided with the timing of the outflow from paddy fields, suggesting that microcapsules that flowed out of the paddy fields would reach the sea relatively quickly. The results of a tracer experiment supported this conclusion. Intensive observations revealed that microcapsule concentrations varied widely over time, with differences reaching a maximum of 110-fold (range 7.3-783.2 mg/m 3 ) over a 3-day period. Daytime concentrations were higher than those at night, reflecting the fact that microcapsules are discharged from paddies by daytime operations such as puddling and surface drainage. Microcapsule concentrations in the river were not correlated with river discharge, making estimating their loading a future research challenge., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Education in Japan is segmented into 6 years of elementary school, 3 years of junior high school, 3 years of high school, and 4 years of university, with elementary and junior high education compulsory. Polymer education in Japan starts at the elementary school level, where the iodine-starch reaction is taught, typically as hands-on, experimental lessons in a science class. At the high school level, the concepts of 'polymers' and 'polymerization' are taught in chemistry class but not in detail. Details are treated as optional subjects in the curriculum and are not included in university entrance exams; students generally do not choose to spend much time and efforts on subjects that are not applicable to the exams. Polymer science is taught as an independent subject or an area of organic chemistry or material science at the university level. [ABSTRACT FROM AUTHOR]

Objective: This study assessed the development of stress from polymerization of light-cured dental resin composites for 24 hours after irradiation. Materials and Methods: Initial cracks were made near the edge of a cylindrical hole in glass, and crack lengths were measured. Revolution Formula 2, Kalore and Venus Diamond were polymerized in the hole. Crack lengths were measured at several intervals after irradiation up to 24 hours. Stresses at the composite-glass interface were calculated using the crack lengths. Elastic moduli of the composites were measured at the same time intervals. Results: Interfacial stress and elastic modulus were significantly related to material and time. Stress continued to increase up to 12 hours after irradiation. Significantly lower stresses were measured in Kalore and Venus Diamond than Revolution Formula 2 throughout 24 hours. Stress at 24 hours was two times greater than the stress at 30 minutes. The increase in elastic modulus from 30 minutes to 24 hours ranged from 8 to 24%, which was less than the increase in stress over the same time period. Conclusions: Interfacial stress and elastic modulus of the composites demonstrated the average increases of 155% and 14%, respectively, from 30 minutes to 24 hours after irradiation. [ABSTRACT FROM AUTHOR]

To provide data required for assessing the environmental health and safety risks of nanocomposites, abrasion-induced particle release from single-wall carbon nanotube (SWCNT)/polymer composites with or without thermal aging were evaluated by a shot blast system. First, overall composite weight loss (i.e., overall particle release) as a result of shot blasting was measured. Incorporating 5 wt% SWCNTs in polystyrene (PS) matrix was observed to reduce overall particle release by approximately 30% compared with pure PS. Heat treatment of the 5 wt% SWCNT/PS composites at 100°C for 10 days induced very slight change in overall particle release due to shot blasting. However, heat treatment at 350°C for 1 hr greatly deteriorated the abrasion resistance of the composites, enhancing overall particle release. Second, to verify the existence and form of SWCNTs released from the composites, released particles were observed by electron microscopy. Micron-sized particles with protruding SWCNTs and submicron-sized SWCNT clusters were observed in the particles released from the composites. Heat treatment of the composites at 350°C for 1 hr enhanced SWCNT release, which mainly formed clusters or rope-like bundles. [ABSTRACT FROM AUTHOR]

Soft materials, such as polymers and fibers, are key industries in Japan and play a significant role in our daily lives [1–3]. These materials also contribute to our modern society in a wide range of applications, such as in aircrafts and automobiles, and in a diverse variety of medical, electronic, and optical devices. In the future, it is expected that polymer science and technology will continue to expand and play an important role in research related to the environment [4], energy science [5], green technology [6], and biotechnology [7]. [ABSTRACT FROM AUTHOR]

Abstract: Dental technicians use various materials, particularly metal alloys and monomers and polymers based on methylmethacrylate. Environmental hygiene issues surrounding the work of dental technicians have been recognized. Despite the need for observance of occupational environmental controls and work management, compliance among dental laboratories appears to be low. We evaluated the relationship between genotoxic effects in dental technicians and occupational environmental controls and work management. We used cytokinesis-blocked micronuclei (CB-MN) frequencies in peripheral lymphocytes and metal levels in scalp hair. We also assessed nutritional factors related to anti-genotoxic effects using a self-administered brief diet history questionnaire. Study subjects were 54 male dental technicians and 38 male clerical workers. The parameters on the micronuclei (MN) frequency in dental technicians and clerical workers were analyzed by forward stepwise multiple regression analyses. Age (P <0.01, β =0.561), occupation as a dental technician (P <0.01, β =0.636) and aluminum levels in scalp hair (P <0.05, β =0.213) were risk factors that significantly increased MN frequency. The significant parameters on the MN frequency in dental technicians were observance of hand-washing as work management (P <0.01, β =−0.304), work period (P <0.01, β =0.509), germanium levels in scalp hair (P <0.01, β =−0.314) and workplace (P <0.05, β =0.235). To avoid genotoxic effects, observance of occupational environmental controls and work management is necessary for dental technicians. [Copyright &y& Elsevier]

The plasma-quenching efficiency of the ablated vapor of polymers containing nitrogen atoms was numerically investigated by the inductively coupled thermal plasma technique. Polyamide66 (PA66), which contains nitrogen atoms, was used as a polymer material, and was injected into Ar thermal plasma in a numerical simulation. The simulation model considered heating, melting, and evaporation of polymer powders, and then plasma-quenching phenomena due to polymer ablation. The thermodynamic and transport properties of the ablated vapor were also taken into account. It was found that PA66 vapor has a greater plasma-quenching efficiency than other polymer materials of PTFE, POM, PMMA, and PE. The calculated results were confirmed to be valid by comparison with experimental results in terms of the ablated vapor distribution and powder velocities. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(2): 11-20, 2012; Published online in Wiley Online Library (). DOI 10.1002/eej.21185 [ABSTRACT FROM AUTHOR]

Background: A double-network (DN) gel, which was composed of poly-(2-acrylamido-2-methylpropanesulfonic acid) and poly-(N,N′-dimetyl acrylamide) (PAMPS/PDMAAm), has the potential to induce chondrogenesis both in vitro and in vivo.Purpose: To establish the efficacy of a therapeutic strategy for an articular cartilage defect using a DN gel.Study Design: Controlled laboratory study.Methods: A 4.3-mm-diameter osteochondral defect was created in rabbit trochlea. A DN gel plug was implanted into the defect of the right knee so that a defect 2 mm in depth remained after surgery. An untreated defect of the left knee provided control data. The osteochondral defects created were examined by histological and immunohistochemical evaluations, surface assessment using confocal laser scanning microscopy, and real-time polymerase chain reaction (PCR) analysis at 4 and 12 weeks. Samples were quantitatively evaluated with 2 scoring systems reported by Wayne et al and O’Driscoll et al.Results: The DN gel–implanted defect was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type 2 collagen. Quantitative evaluation using the grading scales revealed a significantly higher score in the DN gel–implanted defects compared with the untreated control at each period (P < .0001). The mean relative values of type 2 collagen mRNAs in the regenerated tissue were obviously higher in the DN gel–implanted defect than in the untreated control at each period. The mean surface roughness of the untreated control was significantly higher than the normal cartilage at 12 weeks (P = .0106), while there was no statistical difference between the DN gel–implanted and normal knees.Conclusion: This study using the mature rabbit femoral trochlea osteochondral defect model demonstrated that DN gel implantation is an effective treatment to induce cartilage regeneration in vivo without any cultured cells or mammalian-derived scaffolds.Clinical Relevance: This study has prompted us to develop a potential innovative strategy to repair cartilage lesions in the field of joint surgery. [ABSTRACT FROM AUTHOR]

Abstract: This study has demonstrated a reliable method of quantifying the total mass of litter on a beach. It was conducted on Ookushi beach, Goto-Islands, Japan, and uses a combination of balloon-assisted aerial photography and in situ mass measurements. The total mass of litter over the beach was calculated to be 716±259kg. This figure was derived by multiplying the litter-covered area (calculated using balloon-assisted aerial photography) by the mass of litter per unit area. Light plastics such as polyethylene made up 55% of all plastic litter on the beach, although more work is needed to determine whether lighter plastics are transported to beaches more readily by winds and ocean currents compared with heavier plastics, or whether lighter plastics comprise a greater percentage of marine litter. Finally, the above estimates were used to calculate the total mass of metals released into coastal ecosystems via plastic litter on beaches. [Copyright &y& Elsevier]

Abstract: Catalytic processes developed and commercialized in Japan during 1994–2009 are reviewed and classified into 6 industrial areas: petroleum and energy, bulk chemicals, polymers, fine chemicals, auto exhaust catalysts, and environmental catalysts. They have contributed to overcome a rise in oil price as well as to promote Green Sustainable Chemistry. While these technologies made significant contributions to respond to social issues or commercial demands, continuous efforts for development of these processes greatly promoted the catalytic science and technologies including catalytic materials, concepts, mechanism and surface science of catalysis. [ABSTRACT FROM AUTHOR]

The variations in the chemical characteristics of asphalt constituents and styrene-butadiene-styrene triblock copolymer (SBS) in the polymer modified asphalt (MA) during degradation process should be clarified to design the effective recycle method of MA. In this study, the chemical characteristics of MA during thermal degradation process were studied in detail. The effects of the period of thermal degradation of MA, the content of asphaltene constituent in MA and the kind of substrate instead of the straight asphalt were discussed from the yield and thermogravimetry (TG) curves of four constituents in MA and the molecular weight distribution of SBS. As a result, the yield of polar constituent (asphaltene) increased gradually with decomposition of SBS during thermal degradation of MA. Decomposition of SBS was enhanced by the low molecular weight substrate, such as aromatic oil. On the other hand, decomposition of SBS was inhibited by MA of high asphaltene content. [ABSTRACT FROM AUTHOR]

Polyimide-based X-ray masks which are generated by optical lithography and electroplating of gold absorbers on a polyimide mask membrane gain attention as low cost masks. The organic membranes generally have problem of (1) pattern edge sharpness, (2) miniaturization of pattern and (3) thermal stability. To make the masks commodity in deep and accurate lithography area, Optnics Precision, Japan, has overcome the above difficulties and realized the masks with advanced performance of pattern accuracy and thermal stability by improving the making process and the material. Good results were obtained in the exposure experiment that used this mask. When this X-ray mask is combined with the electroforming technique and the material development technique that Optnics has, the application to various fields like an industrial field and medical field can be expected. [ABSTRACT FROM AUTHOR]

Abstract: We describe the characterization of polyhydroxyalkanoate (PHA)-producing bacteria isolated from an ammunition-polluted soil in Kitakyushu City, Japan. Over 270 strains were evaluated for PHA accumulation based on a colony staining method using Nile red. Of these, nine strains were selected based on the intensity of Nile red fluorescence and the cells were quantitatively analyzed for PHA by gas chromatography. PHA accumulation was observed in five strains, all of which are inferred to be close to the Bacillus cereus group according to 16S rDNA sequence analysis. Interestingly, these strains produced a PHA copolymer, poly(3-hydroxybutyrae-co-3-hydroxyvalerate) [P(3HB-co-3HV)], with a 3HV fraction up to 2 mol% with glucose as a carbon source. Further characterization was performed on one isolate, B. cereus YB-4. Gel permeation chromatography analysis revealed that the number of average molecular weights of PHA accumulated in B. cereus YB-4 drastically changed from 722,000 to 85,000 over a 72-h cultivation period. Furthermore, the PHA synthase genes were cloned and the deduced amino acid sequences were determined. This study provides new insights into PHA biosynthesis by members of the B. cereus group. [Copyright &y& Elsevier]

The transformation of hydroxy-interlayered vermiculite (HIV) to vermiculite in humid temperate soils may involve the gradual alteration of illitic minerals. However, it is difficult to detect such minor and progressive changes using conventional methods. We measured the amount of the frayed edge site (i.e. the weathering front of illitic minerals) in soil clays using Radiocaesium Interception Potential (RIP) methodology, and elucidated the effect of hydroxy-Al polymers on the frayed edge site that may be occluded within HIV structures in the acidic soils of southwestern Japan. X-ray diffraction patterns showed the progressive transformation of HIV to vermiculite, or further, to smectite in soil clays located in upper horizons and therefore subjected to more intensive podzolization. In this process, the amount of hydroxy-Al polymers (represented by hot-citrate Al) gradually decreased, while the vermiculitic charges increased (represented by Cs-fixing capacity). However, the amount of the frayed edge site (represented by the RIP) firstly increased but then reversed and decreased in the upper layers of podzolic soils. After hot-citrate extraction to remove the hydroxy-Al polymers from HIV, the amount of the frayed edge site increased in HIV-dominated clays, whereas there was a negligible increase in vermiculitic- or smectitic-clays, thus indicating the blockage effect of hydroxy-Al polymers on the frayed edge site. The sequential increase followed by the decrease that we documented in the amount of the frayed edge site along with the HIV-vermiculite-smectite transformation, suggested that the weathering front of illitic minerals was exposed as the HIV layers lose hydroxy-Al polymers. Thereafter, the charges in the exposed frayed edge site might decline under the very acidic conditions of the upper layers of podzolic soils. [ABSTRACT FROM AUTHOR]

Abstract: Advanced composites are widely used for the strengthening of existing concrete structures. Current design guidelines give basic requirements on how to model the enhancement of structural performance of concrete members using surface bonded FRP (fibre reinforced polymer) reinforcement. With respect to this, it is of interest to evaluate the ductility requirements which are explicitly or implicitly imposed by design guides. Based on an evaluation of four major design guidelines in Europe, Japan and North-America, and a small parametric study, the ductility aspect of the design of FRP strengthened concrete members is verified. It appears that the ductility of flexural members strengthened with FRP should be considered with care, as reduced deformability is obtained at ultimate, though generally a minimum deformability is implicitly obtained in a proper design. At the other hand, ductility enhancement by means of FRP confinement is explicitly considered in the design guidelines. [Copyright &y& Elsevier]

Purpose: To evaluate the effect of surface coating of an acrylic intraocular lens (IOL) with poly(2-methacryloyloxyethyl phosphorylcholine) (MPC) on the behavior of the lens epithelial cell (LEC) line, α-TN4. Setting: Department of Ophthalmology, Nihon University School of Medicine, Tokyo, Japan. Methods: A hydrophobic soft acrylic IOL (AF-1, Hoya) was coated with MPC polymer. A noncoated IOL served as control. An IOL from each group was placed on the membrane of collagen I or IV of the cell culture dish. The α-TN4 cells were seeded in the insert. Cell behaviors (ie, cell proliferation and spreading) on IOLs and membranes were observed. Cell migration beneath the IOL optic portion was assayed using a computer software program (POCOman system) for posterior capsule opacification (PCO). Type I or IV collagen is the major matrix component of PCO or native lens capsule. Results: Cell proliferation was more marked on the noncoated IOL than on the coated IOL. Type IV collagen accelerated proliferation more than type I collagen. Cell migration to the area beneath the IOL optic was more prominent in the group with the type I collagen membrane and noncoated IOL than in other groups. Conclusion: Coating an acrylic IOL surface with MPC polymer suppressed adhesion and proliferation of LECs, suggesting it improves IOL biocompatibility. [Copyright &y& Elsevier]

Studies fracture toughness evaluation of adjacent flow weld line in polystyrene by the single-edge notched-bend (SENB) method by researchers from Japan. Suitability of the SENB method on the evaluation of fracture toughness of adjacent flow weld lines; Factors that contribute to the variation of fracture toughness; Explanation of the characteristic features of the weld line by flow-induced molecular orientation at the weld line interface.

Changes of the microstructure and the mechanical properties of injection-molded polypropylene sheets in the flow direction were investigated. The following main results were obtained. With the increase of flow distance, (1) the thickness and the width of test piece decrease and so the cross section are becomes small. (2) The hardness of the skin, the intermediate and the core layer declines; the far ther from the gate the lower the hardness becomes. (3) The crystallinity and the degree of molecular orientation decline. (4) The formation of a secondary flow layer in the core layer is found. In the flow direction, the crystals in the secondary flow layer becomes larger and the degree of molecular orientation declines gradually. (5) The tensile strength declines but the ductility properties rise with the above changes in microstructure. The above results show that the change of microstructure of the injection-molded test piece in flow direction has as strong influence on the mechanical properties. For long slender injection-molded parts, particular attention should be paid since their flow distance is relatively long. [ABSTRACT FROM AUTHOR]

The monolithic type (Mo type) of tablet, where the drug is uniformly dispersed in a tablet, causes drug release in gastric juice with an initial burst. In order to suppress this drug release, we prepared a sandwiched type tablet (Sw type) where the drug layer is put between the layers of a mixed powder of sodium alginate (Al) and methyl glycol chitosan (MG). We then studied the release action based on the difference in tablet structure using theophylline (TH) as the model drug. The amount of TH released from the tablet was measured by absorptiometry (271 nm) upon transferring the tablet from artificial gastric juice (pH 1.2) to artificial intestinal juice (pH 6.8) after a given time. When the tablet was transferred from artificial gastric juice to artificial intestinal juice, the ‘squeezing effect’, in which the release rate rapidly increases, was observed. The release rate increased 1.9 times in the Mo type and 11 times in the Sw type. As a result, the drug release rate in gastric juice could be effectively restrained down to approximately 10% by using the Sw type tablet structure. [ABSTRACT FROM AUTHOR]

The interaction between ionic monomer and metallic salts has been investigated for improvement of the heat resistance of expandable microspheres. Expandable microspheres were prepared by suspension polymerization using acrylonitrile and methacrylonitrile as main ingredients and acrylic acid and methacrylic acid as ionic monomers. To develop heat resisting microspheres, the use of comonomers having higher glass transition temperatures and higher cohesive energy densities, such as methacrylic acid, was found to be useful. Further, the copolymers with carboxyl groups partially neutralized by metal ions such as Na+ showed formation of ionic aggregates, which leads to a high gel level and higher heat resistance. Additionally, the copolymers with Zn2+ showed both good thermal expansion and good heat resistance. Both molecular structures of monomers and interchain cross-linking with strong intermolecular forces such as electrostatic interaction were found to be important for the high heat resistance of the microsperes. [ABSTRACT FROM AUTHOR]

Various bead-shaped pullulan ion exchangers were prepared from crosslinked bead-shaped pullulan. Diethyl-aminoethyl (DEAE) pullulan, 2-hydroxy-3-trimethylpropylammonio (HTMPA) pullulan, and 2-hydroxy-3-&lcub;2-[bis(2-hydroxyethyl) amino]ethoxy&rcub; propyl(ECTEOLA) pullulan were prepared by reacting the crosslinked pullulan with N-2-chloroethyldiethylamine hydrochloride, N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride, and a mixture of 2,3-epoxypropyl chloride (epichlorohydrin) and 2,2′,2″-nitrilotrisethanol (triethanol-amine), respectively. Their anion-exchange capacities and degrees of swelling were ca.2.13, ca. 0.78, ca. 0.62 meq/g and ca. 10.1, ca, 6.5, ca. 8.5 cm³/q, respectively. Carboxymethyl (CM) pullulan and sulfomethyl (SM) pullulan were also prepared by reacting the crosslinked pullalan with chloroacetic acid and sodium chloromethanesulfonate, respectively. Their cation-exchange capacities and degrees of swelling were ca. 1.60, ca. 1.52 meq/g and ca. 11.0, ca. 5.8 cm³/g, respectively. Pullulan ion exchange beads obtained were found to be useful as packing materials for ion exchange chromatography. [ABSTRACT FROM AUTHOR]

The flow-induced structure of immiscible polyolefin blends under steady shear flow was studied by small angle neutron scattering. The sample used was a 3:7 blend (by weight) of i-polypropylene and ethylene-octene random copolymer. At low shear rates, anisotropic scatterring was observed on a two-dimensional detector in through-view measurements (incident beam perpendicular to the flow). The intensity was stronger in the direction perpendicular to the flow direction. In edge-view measurements (incident beam parallel to the flow), no anisotropy was observed. At higher shear rates (>50 sec-1, the anisotropy became very weak but the intensity itself became rather strong. A simple explanation of these observations can be given by assuming the existence of string-like domains at low shear rates and their splitting at high shear rates. This idea can be supported by the low interfacial tension between two polyolefins. [ABSTRACT FROM AUTHOR]

Poly (lactic acid) (OLA) composite hydrogels with poly(vinyl alcohol) (PVA) were obtained by the repeat-freeze thaw method. A mixture of PLA fine particle aqueous dispersion and PVA aqueous solution with high degree of the saponification was used. These hydrogels could be obtained even for very low contents of PVA: 1/20∼1/100 of PVA/PLA. The hydrogel can be prepared over the range from the rubber-like elasticity solid to the brittle solid by the change of the mixture proportion of PVA. A porous dried gel was obtained by drying the hydrogel at room temperature. The dried gel turned into the hydrogel by immersion in water. However, as the content rate of the PLA increases, dried gels would be able to absorb not only aqueous solution but also hydrophobic liquids such as a hydrocarbon. The SEM observation of the dried gel suggested that PVA covered the surface of PLA and cross-linked by physical bonds such as hydrogen bonds. [ABSTRACT FROM AUTHOR]

A new porous ion exchange resin having an open-celled monolith structure was prepared and its ion exchange properties The new ion exchange resin was found to have the following advantages over the conventional ion exchange resins having First, the new ion exchange resin has a high adsorption ability for the ions having low selectivity coefficients, and the ion length is smaller than that of the conventional resins. Second, in an electric field, the rejection time of the ions adsorbed to change resin was about one twentieth of that of the ions containing the conventional resins. These specific properties of the new ion exchange resin are attributable to the quantitative introduction of ion exchange groups into the resin having a uniform open-celled monolith structure. [ABSTRACT FROM AUTHOR]

Acrylonitrilestyrene copolymer/clay nanocomposite (AS-clay) was prepared by copolymerization of acrylonitrile and styrene in the presence of monmorillonaite-type clay that had been modified with 4-vinylpyridine and benzalkonium chloride. The spacing of the intercalation in the nanocomposites was investigated by X-ray diffraction and FT-IR. Izod impact and burning rate of ABS resin mixed with AS- clay were examined. The ABS/clay nanocomposite had low Izod impact strength and high burning resistance, as compared with the valves for ABS resin. [ABSTRACT FROM AUTHOR]

Examines the developments in biomaterials in Japan. Use of synthetic polymer systems; Analysis on polymerization reactions; Formulation of phosphorylcholine-containing contact lens.

Describes the immobilization of double-stranded DNA onto porous glass beads through ultraviolet radiation in Tokyo, Japan. Removal of chemical compounds; Difficulty to reproduce DNA molecules in synthetic polymers; Utilization of modified DNA.

The increase in communications facilities is accompanied by a rapid increase in the number of groundings required. However, it is difficult to achieve the required ground resistance values in areas of high grounding resistance such as volcanic ash, sandy or rocky soils, so that there is a strong need for the use of ground resistance reducing materials. This article proposes a method of reducing ground resistance using water-absorbent polymers. The use of water-absorbent polymer materials is expected to provide approximately twice the resistance reducing effect as currently used materials. When selecting such materials for placement in the soil, it is necessary to consider susceptibility to decomposition by microorganisms as well as temperature characteristics. One type of water-absorbent polymer, anhydrous maleic acid polymers, is found to satisfy both requirements. In addition, the use of such polymers as ground resistance reducing materials requires approximately 1/160 the quantity of currently used bentonite mixtures and causes approximately 1/10 to corrosion of the copper used in grounding electrodes, demonstrating that water-absorbent polymers are a highly useful method of reducing grounding resistance. [ABSTRACT FROM AUTHOR]

The section presents abstracts of studies which appeared in volume 60, Number 10, 2003 issue of Japanese Journal of Polymer Science and Technology. Photochemically Induced Refractive Index and Fluorescence Control in Polymer Films. Negative- and Positive-Tyoe Photopatterning Methods of an Adsorbed Monomolecular Film Formed From Multivalent Cationic Adsorbates. Cooperative Orientation in Composite Films Containing Photocrosslinkable Polymer Liquid Crystals and Non-Photoreactive Monomers With Biphenyl Group.

This review reflects back over almost 40 years of the author's basic research conducted at Graduate School of Pharmaceutical Sciences, Osaka University, Japan. After performing postdoctoral research in USA, the author became a research associate at Prof. Yoshiharu Miura's lab and started research on Biochemical Engineering in 1984. At that time, the main research purpose was to solve global environmental issues for maintaining human health. The author's achievements included novel useful material production system under inorganic conditions and genetically engineered whole-cell bacterial sensors detecting arsenite by naked eye without a detecting device. Another theme in the lab was to construct bioartificial liver support system. Various scaffolds for hepatocytes were newly prepared for constructing the compact reactor. Besides the bioreactor study, the author conducted cell transplantation research for the treatment of chronic liver diseases. It was shown that mesenchymal stem cells derived from third molars (wisdom teeth) could differentiate into hepatocytes and exhibit therapeutic effects in liver-damaged animals. After 2006, the lab started research on drug delivery systems, including noninvasive delivery of drugs such as peptides and nucleic acids by regulating epithelial tight junctions. Many substances enabling drug delivery through "paracellular" route were newly prepared. The author started basic research on Biochemical Engineering in the 1970s. Although these studies eventually shifted into the pharmaceutical field, the underlying concept was based on "engineering" throughout a 40-year research period. The author cordially thanks all colleagues for supporting engineering research in our lab.

Aims: The aim of this study was to establish the long-term safety and efficacy of a sirolimus-eluting stent with bioresorbable polymer (BP-SES; Ultimaster) by comparison with an everolimus-eluting stent with permanent polymer (PP-EES; XIENCE)., Methods and Results: CENTURY II (Clinical Evaluation of New Terumo Drug-Eluting Coronary Stent System in the Treatment of Patients with Coronary Artery Disease) is a large-scale, prospective, multicentre, randomised single-blind, controlled, non-inferiority trial conducted at 58 study sites globally, including Europe, Japan and Korea, powered to prove non-inferiority for freedom from target lesion failure (TLF: cardiac death, target vessel-related myocardial infarction [MI] and target lesion revascularisation) at nine months. Patients requiring a percutaneous coronary intervention (PCI) were randomised (1:1) to BP-SES (n=551) or PP-EES (n=550). Freedom from TLF at five years was 90.0% in the BP-SES and 91.1% in the PP-EES group (p=0.54). The patient-oriented composite endpoint (all death, any MI, any revascularisation) was 24.1 and 25.6% (p=0.57) with BP-SES and PP-EES, respectively. The very late stent thrombosis rate from one to five years was especially low at 0.2% in both arms., Conclusions: This randomised clinical trial showed that the BP-SES stent was non-inferior to the benchmark PP-EES stent for TLF. Safety and efficacy measures were comparable up to five-year follow-up after PCI.

Previously, it has been suggested that melanoidin-like products (MLP) from sugarcane molasses may accelerate copper phytoextraction. In this study, we evaluated the facilitatory effect of MLP on phytoextraction in a medium including cadmium or lead, the concentrations of which were adjusted around the regulation values of the Soil Contamination Countermeasures Act in Japan. Three Brassica species were tested based on their fast growth, high biomass productivity, and high heavy metal absorption. Both biomass and lead uptake in the nutrient medium with 1 mM lead nitrate were significantly increased by the addition of MLP, and almost all of the lead was accumulated in the root tissue. Therefore, MLP were able both to detoxify lead ions and to improve their bioavailability in Brassica species. In contrast, only these species with MLP or citric acid survived in the nutrient medium with 1 mM cadmium sulfate. The phytoextraction of cadmium using these species was therefore impractical under the Act.

Various generic transdermal formulations of tulobuterol containing rubber and acrylate base polymers are commercially available in Japan. However, none of the formulations have been compared directly with respect to the skin permeability of tulobuterol and to their follow ability. Tulobuterol Tape Sawai of rubber base and Tulobuterol Tape NP of acrylate base were used to conduct the in vitro 24-hour skin permeability test of tulobuterol at receiver solution temperatures of 32°C, 37°C, and 40°C. Furthermore, the followability of these tapes were examined by measuring the depth of the pores that were formed in their adhesive layer. Consequently, the maximum flux of tulobuterol was greater for Tulobuterol Tape NP. Arrhenius plot analysis revealed that Tulobuterol Tape Sawai was more sensitive to skin surface temperature compared with Tulobuterol Tape NP. Skin abrasion had a greater effect on the skin permeability of tulobuterol in Tulobuterol Tape Sawai than in Tulobuterol Tape NP. Followability was greater for Tulobuterol Tape NP than for Tulobuterol Tape Sawai. These results suggest that a transdermal formulation of acrylate base is preferable to that with a rubber base when skin surface temperature varies or when the skin is abraded. In clinical settings, therefore, a formulation of acrylate base is preferable to a formulation of rubber base when skin surface temperature varies or when the skin is abraded. The formulation needs to be applied to the skin of less asperity for the achievement of better transdermal absorption of tulobuterol.