Hydrogen-bond-assisted stereocontrol in the radical polymerization of N-isopropylacrylamide with bidentate Lewis base

Radical polymerization of N-isopropylacrylamide (NIPAAm) in toluene was investigated in the presence of bidentate Lewis base such as diphosphonates. Isotacticity of the obtained poly(NIPAAm)s slightly increased at –80°C, whereas syndiotactic-rich poly(NIPAAm)s were obtained at –40 to 0°C. This result corresponded to the results observed in the presence of primary alkyl phosphates. NMR analysis revealed that NIPAAm monomer and tetraisopropyl methylenebisphosphonate formed mono-binding hydrogen-bond-assisted complex at 0°C, but a chelate complex at –80°C. Thus, it was concluded that the stereospecificity in NIPAAm polymerization strongly depended on the complexation mode of the added bidentate Lewis base

HYDROGEN-BOND-ASSISTED STEREOCONTROL

Radical polymerization of N-isopropylacrylamide (NIPAAm) in toluene at low temperatures was investigated in the presence of triisopropyl phosphate (TiPP). The addition of TiPP induced a syndiotactic-specificity that was enhanced by lowering polymerization temperature, whereas atactic polymers were obtained in the absence of TiPP regardless of temperature. Syndiotactic-rich poly(NIPAAm) with racemo diad = 65% was obtained at –60°C with a fourfold amount of TiPP, but almost atactic poly(NIPAAm)s were obtained by lowering temperature to –80°C. This result contrasted with the result in the presence of primary alkyl phosphates, such as tri-n-propyl phosphate, that stereospecificity varied from syndiotactic to isotactic by lowering polymerization temperature. NMR analysis at –80°C revealed that TiPP predominantly formed 1:1 complex with NIPAAm, although primary alkyl phosphates preferentially formed 1:2 complex with NIPAAm. Thus, it was concluded that a slight increase in bulkiness of the added phosphates influenced the stoichiometry of the NIPAAm-phosphate complex at lower temperatures and consequently a drastic change in the effect on stereospecificity of NIPAAm polymerization was observed

Stereocontrol in NIPAAm polymerization

Radical polymerizations of N-isopropylacrylamide (NIPAAm) were carried out in toluene at low temperatures in the presence of phosphoric acid esters such as trimethyl, triethyl (TEP), tri-n-propyl, and tri-n-butyl phosphates (TBP). Syndiotactic-rich poly(NIPAAm)s were obtained at the temperature range from –60°C to 0°C, and particularly TEP provided the highest syndiotacticity (racemo diad = 65%) at –40°C. On the other hand, lowering temperature reversed the stereoselectivity of the propagation reaction so that isotactic-rich poly(NIPAAm)s were obtained at –80°C. In particular, TBP exhibited the most isotactic-specificity (meso diad = 57%). Job's plots for NIPAAm-TBP mixtures revealed that NIPAAm and TBP formed 1:1 complex at 0°C and predominantly 1:2 complex at –80°C through a hydrogen-bonding interaction. Therefore, it is considered that the stereospecificity of NIPAAm polymerization should depend on the stoichiometry of the hydrogen-bond-assisted complex. Thus, the mechanism for the present polymerization system was discussed

Dual Roles of Alkyl Alcohols as Syndiotactic-Specificity-Inducer and Accelerator in the Radical Polymerization of N-Isopropylacrylamide and Some Properties of Syndiotactic Poly(N-isopropylacrylamide)

Effect of simple alkyl alcohol on radical polymerization of N-isopropylacrylamide (NIPAAm) in toluene at low temperatures was investigated. We succeeded in induction of syndiotactic-specificity and acceleration of polymerization reaction at the same time by adding simple alkyl alcohols such as 3-methyl-3-pentanol (3Me3PenOH) into NIPAAm polymerization. The diad syndiotacticity increased with a decrease in temperature and an increase in bulkiness of the added alcohol, and reached up to 71% at –60°C in the presence of 3Me3PenOH. With the aide of NMR analysis, it was revealed that alcohol compounds play dual roles in this polymerization system; alcohol compound coordinating to N-H proton induces the syndiotactic-specificity and that hydrogen-bonded to C=O oxygen accelerates the polymerization reaction. The effect of syndiotacticity on properties of poly(NIPAAm)s was also discussed in some detail

「総合日本語」の授業で行うゼロ初級からの音声教育の実践 : アクセント,イントネーションの自然性を重視した視覚化補助教材の使用

吉林華橋外国語学院Jilin HuaQiao University of Foreign Languages1節では,本研究が国立国語研究所共同研究プロジェクト「日本語教育のためのコーパスを利用したオンライン日本語アクセント辞書の開発」の一部であり,web辞書構築の土台となる韻律教育の効果を,紙媒体を使って検証してきたものであることを述べた。2節では,音声の特徴と,学習者の日本語らしい音声習得へのニーズの高さについて述べた。3節では,日本と中国で学習者の日本語音声に対する関心は高くても,音声教育が体系的に行われていないこと,従来の教科書には単音や語のアクセント型の記述はあっても,連語のアクセントや文のイントネーションの記述は少ないこと,しかし最近は韻律の重要性の認識が高まり,韻律学習を目的とした教材の出版が顕著に増えているが,現在のカリキュラムや教材の中で音声教育が自然に導入されることが理想的であることを述べた。4節では,中国語話者の日本語発話の韻律的特徴について述べた。中国語話者のピッチパターンでは,文節ごとの急峻なピッチの上下変動がみられ,音響的な意味のまとまりの形成を阻害すること,日本語にはないアクセント型が出現しやすいことを述べた。5節では,従来の音声教育の問題点を踏まえ,web辞書OJAD開発に関わる教育効果を検証するために,開発と並行して行ってきた紙媒体での音声教育の実践方法について述べた。6節では,音声教育実践の効果についてアンケート調査をもとに分析を行った。ゼロ初級からの音声教育は従来のカリキュラムを変更することなく行え,韻律視覚化教材使用によって教師と学習者間で音声に関して様々な気づきと対話が生まれ,教師は基準をもとに自信を持って指導することができるようになり,学習者は音声学習を負担に感じるよりむしろ面白いと答えた。7節では,教材のweb化,OJADの開発について紹介した。This paper reports on the introduction of Japanese prosody learning for beginners in an integrated Japanese course at a Chinese university. The first section addresses how practical findings on Japanese prosody education were introduced into our collaborative project to develop the Online Japanese Accent Dictionary (OJAD) with the National Institute for Japanese Language and Linguistics. The second section explains Japanese prosodic features and the learners\u27 need to acquire more naturally sounding Japanese pronunciation. Section 3 points out the lack of opportunity for systematic prosodic learning for students. For example, accent control in conjugated words and intonation control within phrases and sentences are not well explained in Japanese textbooks. Section 4 describes the prosodic features of Japanese sentences that characterize Chinese speakers\u27 accents. Section 5 outlines the practical methods of speech education that were developed for a Japanese integrated course for freshmen students majoring in Japanese at the university. Section 6 analyzes the result of a questionnaire survey distributed at the end of the first semester regarding effectiveness of the visualized prosody material. Results showed that 88% of learners surveyed found the materials to be useful, 82% of learners paid careful attention to Japanese speech sounds when practicing, and 78% of learners found learning Japanese prosody interesting. Section 7 describes the OJAD system, which supports prosody learning for Japanese learners all over the world

Versatile Psychophysiological Potencies of Essential Oils, when Seen as a Function of Behavioral Task Assigned to the Participants after Inhalation

To elucidate the psychophysiological effect of inhaling essential oils, in this paper, we sought to assess the following 12 essential oils: basil, bergamot, cardamom, cinnamon, juniper, lemon, orange, palmarosa, peppermint, sandalwood, spearmint, and ylang ylang. As these being target odors, we focused on the verbal (semantic) and non-verbal (skin temperature) endpoints of the stimuli. In our experimental design, we managed to assign different behavioral tasks to the participants. The Uchida-Kraepelin test was used as a mental arithmetic task and listening to environmental (natural) sounds as an auditory task. In the verbal study, for an example, we conducted the sensory test twice, once before and once after the task. As a measure of the perceived odor quality in participants after inhalation of a given aroma, we employed a sensory evaluation spectrum. It is a bar graph in which the mean of the difference in score between pre- and post-task inquiry (post minus pre) was plotted against the impression descriptors. Taking into account of the obtained skin temperature changes between pre- and post-task inhalations, the subtle nuances between verbal and non-verbal expressions seen as a function of the two behavioral tasks assigned to the participant suggested that essential oils may have versatile psychophysiological potencies by the nature

Very low-density lipoprotein-apoprotein CI is increased in diabetic nephropathy: Comparison with apoprotein CIII

Very low-density lipoprotein-apoprotein CI is increased in diabetic nephropathy: Comparison with apoprotein CIII.BackgroundRecent studies have suggested that apoprotein (apo) CI in very low-density lipoprotein (VLDL) plays an important role in causing hypertriglyceridemia independent of apo CIII, which is associated with coronary heart disease (CHD). Because the incidence of CHD is increased in diabetic patients and is even higher when diabetic nephropathy is developed, we measured apo CI levels in VLDL from type 2 diabetic patients, with various degree of nephropathy, and compared the results with those for healthy controls or nondiabetic patients with chronic renal failure (CRF).MethodsThis study enrolled healthy control subjects, type 2 diabetic patients with normoalbuminuria, microalbuminuria, overt proteinuria, and CRF on hemodialysis and nondiabetic hemodialyis patients. VLDL (density <1.006) was separated by ultracentrifugation. Then the apo CI, CIII, and B concentrations in VLDL were measured by enzyme-linked immunosorbent assay (ELISA).ResultsThe apo CI, CIII, and B concentrations in VLDL were respectively 3-, 2-, and 2-fold higher, respectively, in diabetic patients with overt proteinuria than in controls. Hemodialysis patients with diabetic nephropathy had levels of apo CI, CIII, and B in VLDL that were 2.6-, 2.7- and 2-fold higher, respectively, than those in controls. Nondiabetic hemodialysis patients also had a 2.7-fold higher level of VLDL apo CIII, whereas VLDL apo CI and VLDL apo B were not significantly increased. VLDL apo CI was significantly correlated with VLDL apo B independently of VLDL apo CIII level.ConclusionAn increase of VLDL apo CIII is a prominent feature of dyslipidemia in CRF patients, regardless of whether they are diabetic or nondiabetic, whereas an increase of VLDL apo CI is more specific to diabetic nephropathy and is closely associated with an increase of VLDL particle numbers, a new risk factor for CHD

Offshore-origin warm water inflows toward Totten Ice Shelf, East Antarctica

The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Thu. 5 Dec. / 2F Auditorium , National Institute of Polar Researc