Amphiphilic graft copolymers: Effect of graft chain length and content on colloid gel

Nitta, Kyohei,Kimoto, Atsushi,Watanabe, Junji,Ikeda, Yoshiyuki Techno-Press 2015 Biomaterials and biomedical engineering Vol.2 No.2

A series of amphiphilic graft copolymers were synthesized by varying the number of graft chains and graft chain lengths. The polarity of the hydrophobic graft chain on the copolymers was varied their solution properties. The glass transition temperature of the copolymers was in the low-temperature region, because of the amorphous nature of poly (trimethylene carbonate) (PTMC). The surface morphology of the lyophilized colloid gel had a bundle structure, which was derived from the combination of poly(N-hydroxyethylacrylamide)( poly(HEAA)) and PTMC. The solution properties were evaluated using dynamic light scattering and fluorescence measurements. The particle size of the graft copolymers was about 30-300 nm. The graft copolymers with a higher number of repeating units attributed to the TMC (trimethylene carbonate) component and with a lower macromonomer ratio showed high thermal stability. The critical association concentration was estimated to be between $2.2{\times}10^{-3}$ and $8.9{\times}10^{-2}mg/mL$, using the pyrene-based fluorescence probe technique. These results showed that the hydrophobic chain of the graft copolymer having a long PTMC segment had a low polarity, dependent on the number of repeating units of TMC and the macromonomer composition ratio. These results demonstrated that a higher number of repeating units of TMC, with a lower macromonomer composition, was preferable for molecular encapsulation.

Analysis of contact stiffness between metal ground surfaces using thin PET film

NItta Isami,Hasegawa, Takashi ENGINEERING TRIBOLOGY RESEARCH INSTITUTE KYUNGPOOK 1999 INTERNATIONAL SYMPOSIUM ON HIGH PERFORMANCE OF TRI Vol.1999 No.-

In a previous paper, we developed a thin polymer film method which was able to measure the real contact area. In this polymer film method was used to analyze the contact stiffness. In unloading and reloading processes, the real contact area and its distribution were measured by this method at each load. As a result, it turned out the non-uniform contact over the apparent contact area at the low normal load corresponded to rapid change in the contact stiffness. As the normal load was increased, the contact condition gradually approached the uniform contact, leading the contact stiffness to almost constant value. These measurements by the thin polymer film method indicated that the waviness had strongly influenced the contact stiffness more than the surface roughness did. In addition, we carried out the numerical simulation of the contact stiffness on the consideration of only the waviness. The simulated results were in good agreement with the experimental results.

Weight Gain and Alcohol Drinking Associations with Breast Cancer Risk in Japanese Postmenopausal Women - Results from the Japan Collaborative Cohort (JACC) Study

Nitta, Junichi,Nojima, Masanori,Ohnishi, Hirofumi,Mori, Mitsuru,Wakai, Kenji,Suzuki, Sadao,Fujino, Yoshihisa,Lin, Yingsong,Tamakoshi, Koji,Tamakoshi, Akiko Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.3

Background: We investigated four factors, height, weight gain since age 20, physical activity, and alcohol drinking, for associations with risk of breast cancer (BC) according to menopausal status, using the latest data of the Japan Collaborative Cohort Study (JACC Study). Materials and Methods: We confined the analysis to 24 areas available of cancer incidence information, excluding women with a previous diagnosis of BC. Baseline data were collected from 38,610 (9,367 premenopausal, and 29,243 postmenopausal) women during 1988 and 1990. The study subjects were followed-up at the end of 2009, and 273 (84 premenopausal, and 189 postmenopausal) cases of BC were newly diagnosed in 501,907 person-years. The Cox model was used to estimate a hazards ratio (HR) and its 95% confidence interval (CI) of BC risk. Results: As a result of the multivariate analysis adjusting for age at baseline survey, age at menarche, number of live births, and, age at first delivery, weight gain since age 20 of 6.7 kg-9.9 kg, and ${\geq}10.0kg$ were significantly associated with increased risk for postmenopausal BC (HR=2.48, 95% CI 1.40-4.41, and, HR=2.94, 95% CI 1.84-4.70, respectively). Significantly increased trend of BC risk was also observed in weight gain since age 20 (p for trend, p<0.001). Amount of ethanol intake per day${\geq}15.0g$ was significantly associated with increased risk for postmenopausal BC in the multivariable-adjusted analysis (HR=2.74, 95% CI 1.32-5.70). Conclusions: Higher weight gain in adulthood and larger amounts of ethanol intake were significantly associated with increased risk of BC in Japanese postmenopausal women. None of the investigated factors were significantly associated with BC risk in Japanese premenopausal women.

Amphiphilic graft copolymers: Effect of graft chain length and content on colloid gel

Nitta, Kyohei,Kimoto, Atsushi,Watanabe, Junji,Ikeda, Yoshiyuki Techno-Press 2015 Biomaterials and Biomechanics in Bioengineering Vol.2 No.2

A series of amphiphilic graft copolymers were synthesized by varying the number of graft chains and graft chain lengths. The polarity of the hydrophobic graft chain on the copolymers was varied their solution properties. The glass transition temperature of the copolymers was in the low-temperature region, because of the amorphous nature of poly (trimethylene carbonate) (PTMC). The surface morphology of the lyophilized colloid gel had a bundle structure, which was derived from the combination of poly(N-hydroxyethylacrylamide)( poly(HEAA)) and PTMC. The solution properties were evaluated using dynamic light scattering and fluorescence measurements. The particle size of the graft copolymers was about 30-300 nm. The graft copolymers with a higher number of repeating units attributed to the TMC (trimethylene carbonate) component and with a lower macromonomer ratio showed high thermal stability. The critical association concentration was estimated to be between $2.2{\times}10^{-3}$ and $8.9{\times}10^{-2}mg/mL$, using the pyrene-based fluorescence probe technique. These results showed that the hydrophobic chain of the graft copolymer having a long PTMC segment had a low polarity, dependent on the number of repeating units of TMC and the macromonomer composition ratio. These results demonstrated that a higher number of repeating units of TMC, with a lower macromonomer composition, was preferable for molecular encapsulation.

문법과 사서 : 동사의 기술을 중심으로

Nitta, Yoshio 한국일어일문학회 1996 日語日文學硏究 Vol.29 No.1

A Rapid Measurement of Pesticides Residues in Broccoli Based on IR Spectroscopy

Yuuki Nitta,Hiroaki Ishizawa,Takuma Goto,Yuichi Miyahara,Kazuhiko Komatus 제어로봇시스템학회 2006 제어로봇시스템학회 국제학술대회 논문집 Vol.2006 No.10

Referential Structure-A Mechanism for Giving Word-Definition in Ordinary Lexicons

( Yoshihiko Nitta ) 한국언어정보학회 1992 국제 워크샵 Vol.1992 No.-

Superficially an ordinary lexicon is merely a compiled list of the word-definitions. And usually people use ordinary lexicons just by finding an entry-word and reading the corresponding description. But in spite of the superficial simplicity, the actual word definition mechanism of ordinary lexicons is fairy complicated. This paper tries to formulate this mechanism based on the concept of referential stucture. The referential structure naturally derives the referential network composed of word-reference-path, which can be regarded as a fundamental word-definition mechanism of ordinary lexicons. Hha t is, human extracts his wanting word-knowledge from this referential network using the support of [implicit] commonsense. This paper also gives the method of how to extract the word-knowledge form the referential network. This method is based on the network traversing and pattern-matching which is currently designed in rather simple and naive way, and thus, is to be easily implemented. As for the word-knowledge to be extracted, currently I suppose those which go along with the conceptual relations, such as, is-a, have-a, is-a-member-of, is -composed-of, is -an-example-of, etc, l believe that my proposd mechanism will make a good theoretical base for constructing various natural language understanding applications.

Aortoesophageal Fistula after Thoracic Endovascular Aortic Repair for Blunt Thoracic Aortic Injury

( Masakazu Nitta ),( Taro Tamakawa ),( Natsuo Kamimura ),( Tadayuki Honda ),( Hiroshi Endoh ) 대한외상학회 2019 大韓外傷學會誌 Vol.32 No.3

Although thoracic endovascular aortic repair (TEVAR) has grown to become the standard of care to treat blunt thoracic aortic injury (BTAI), the long-term effects of TEVAR are still unclear. We here present a 72-year-old man with BTAI due to a traffic accident. He successfully underwent TEVAR and was transferred to another rehabilitation hospital 2 months after the accident. However, 1 month later, he underwent gastroscopy with fever and hematemesis and was diagnosed with aorto-esophageal fistula (AEF). After being re-transferred to Niigata University Medical and Dental Hospital, we tried to convince him to undergo surgical treatment, but he strongly refused. He received palliative care and died due to rupture of the aortic pseudoaneurysm 3 days after the hospital transfer. Fatal complications like AEF may occur after TEVAR, so clinicians need to carefully follow patients who underwent TEVAR.

Comparing Minimum Wage Setting Mechanisms in Japan and Korea: Searching for the Sources of Difference

Michio Nitta,Jongwon WOO 한국고용노사관계학회 2019 産業關係硏究 Vol.29 No.1

The paper examines developments on minimum wage setting mechanisms (MWSM) in Japan and Korea in recent years, focusing on institutions, processes and outcomes of MWSM. Such attributes of the institution are examined as the basic minimum wage setting structures, the constitutions and deliberation procedures of the consultative bodies, and the factors considered in deciding annual minimum wage deliberation. Some similarities are found. Both countries heavily rely on tripartite committees at the national level. Besides, both governments try to influence minimum wage setting procedures by indicating higher minimum wage is desirable. Contrarily, some differences are discovered. One difference is shown in the process of MWSM: it is much tougher in Korea than Japan. Another difference is observed in the outcome of MWSM: the minimum wages have increased much faster and higher in Korea than in Japan. From a system perspective, the differences may be related to what factors minimum wage setting organizations consider. While income distribution is one of the important factors to be considered in Korea, it is not the case in Japan. It seems that the Korean MWSM is assigned a wider role to reduce income gap among workers, while the Japanese counterpart is allowed to focus more on specifically low wage group of workers. The authors remind people of policy circles of the importance of wider perspective in examining performance of minimum wage policy. A minimum wage policy may produce expected results under certain circumstances and may not under other conditions. In order to reach a conclusion, one needs to consider wide range of related policies besides economic/social factors.

Cultivation History Entry System for Agricultural Products

Hitoshi Nitta,Hiroki Takeda,Teruhisa Hochin 대한전자공학회 2008 ITC-CSCC :International Technical Conference on Ci Vol.2008 No.7

Pesticide legislation in Japan is very complex. It is a virtually impossible task that the farmer understands all of this law. To solve this problem, the authors have developed “Cultivation History Entry System for Agricultural Products”. Even the farmer who does not completely understand pesticide legislation comes to be able to do farm works that uphold pesticide legislation by using this system. This system equips improved usability by adoption of AJAX (Asynchronous JavaScript+XML) technology. Because this technology enables a server access without screen transition, this system is superior to the past system for agricultural products in response performance and visibility.