32970 research outputs found
Sort by
Novel Polyurethane-Catalyzed Cyclic Carbonate Synthesis Using CO2 and Epoxide
No full textThe conversion of industrially produced greenhouse gases, like CO2, into value-added chemicals is economically beneficial to industry and vital for environmental conservation. However, the conditions for these conversions must themselves be sustainable. In this work, polyurethane (PU) was used to catalyze the formation of five-membered cyclic carbonates (5CCs) via cycloaddition of epoxides and CO2. Using optimized conditions, the representative epoxide, phenyl glycidyl ether, afforded the corresponding 5CC (PGE-5CC) in a quantitative yield with remarkable selectivity (>99%). The PU catalyst does not degrade during the reaction and is separable by simple filtration. In addition, PU could catalyze the 5CC synthesis at least 10 times without loss of catalytic activity and is applicable to a wide range of substituted epoxides. This study pioneers the utilization of polyurethane as an easily recycled catalyst in halogen-free and metal-free reactions for the repurposing of CO2 waste
The Relationship between Circumstances of Internet Use and Tendency of Internet Addiction among Nursing Students
No full text目的：看護大学生のインターネット依存傾向と，生活習慣，対人関係，精神的健康度，インターネット利
用状況との関連について明らかにする．
方法：Ａ大学看護学生 1 ～ 4 年生の223名に対し，無記名自記式質問紙調査を実施した．調査項目は，基本
属性，生活習慣，対人関係，精神的健康度（K6），インターネット利用状況，インターネット依存傾向
（Internet Addiction Test; 以下IAT），インターネットの利用目的とし，IAT得点と各項目との関連を分析した．
結果：回答者は170名で，回答に不備がない146名について分析した．IAT得点の平均（標準偏差）は37.9
（12.8）点で，ネット依存傾向（低）96名（65.8％），依存傾向（中）48名（32.9％），依存傾向（高）2 名
（1.4％）であった．IAT得点と関連が見られた項目として，朝食摂取頻度が低い（p＝.031），家族満足度が
低い（p=.034），精神健康度が悪い（r=.304, p<.001），ネット利用時間が長い（r=.360, p<.001）人はIAT得
点が高かった．また，大規模掲示板閲覧（p=.006），Twitter投稿（p=.025），オンラインゲーム（p=.014），
フリーマーケット閲覧（p=.026），ネットショッピング（p=.013）を常用している人はIAT得点が高かった．
結論：看護大学生のネット依存傾向は朝食摂取頻度，家族満足度，精神健康度，インターネットの利用時
間と関連しており，インターネットの利用目的による違いが見られた
Are university students continuing their oral-dental health practices as performed in childhood?
Get PDFObjectives: This study aimed to evaluate the correlation between university students' oral-dental health behavior in their childhood and at present. Methods: A self-administered anonymous questionnaire survey was performed with 3rd and 4th year university students in Nagasaki. The questionnaire included questions regarding oral-dental health practices related to toothbrushing, dental health check-ups, fluoride varnish, self-checking of oral and dental conditions, eating habits of sweets, mastication during eating, and frequency of toothbrush renewal, both currently and that of in childhood during primary school years.
Results: A total of 150 responses were analyzed. It was found that students brush their teeth 2.9 ±
0.9 (mean ± standard deviation) times per day, while they brushed 2.7 ± 0.7 times per day in childhood (r = 0.339). Seventy two of the students brushed their teeth 3 times or more per day at both the time of the survey and in childhood (48.0%).
Conclusion: It is necessary to establish oral-dental health behaviors as part of everyday lifestyle from childhood with continuous intervention of oral-dental health promotion
Long-wavelength Fluorogenic Derivatization of Aryl Halides Based on the Formation of Stilbene by Heck Reaction with Vinylbenzenes
Get PDFThe long-wavelength fluorogenic derivatization method for aryl halides was developed based on stilbene formation by the Heck coupling reaction between aryl halides and vinylbenzenes in the presence of palladium(II) acetate as a catalyst. Fluorescent maximum wavelengths of the derivative obtained by the proposed reaction were 365 - 450 nm, which were 50 - 100 nm longer than those of the biphenyl derivatives formed with our previously developed fluorogenic derivatization method. Also,by the investigation using vinylbenzenes containing electron-donating or -withdrawing functional groups,
it was found that an internal charge transfer system could contribute to extend the emission wavelength of the derivative.
Furthermore, the proposed reaction was applied to develop a pre-column derivatization HPLC with fluorescence detection method for aryl bromides using 4-vinylanisole. p-Substituted aryl bromide derivatives (i.e., p-bromobenzonitrile, p-bromoanisole, bromobenzene, p-bromobenzoic acid ethyl ester, p-bromotoluene) were successfully detected within 40 min with the detection limit of 0.007 - 0.264 μM. Despite the short reaction time of 10 min, the reaction yields for p-bromoanisole and bromobenzene were good at 101 and 87%, respectively
Study of Wake Interaction and Discrete Frequency Noise of a Forward Curved Fan
Get PDFIn order to clarify the physical mechanism of unpleasant fan noise, the discrete frequency noise (DFN) generated from a forward curved fan is evaluated quantitively based on the wake characteristics. The volute tongue of the scroll casing is replaced by a cylinder as an obstacle in order to simplify the mechanical model. Moreover, an analytical prediction model for the DFN generated by the wake interaction to the volute tongue of the scroll casing based on the wake characteristics of the impeller is proposed. To compare the prediction and measurement of the noise level, the influence of the clearance of the volute tongue on the DFN of the fan from the viewpoint of fluid dynamics is evaluated. The aerodynamic noise source was formed at the rear side of the impeller, which had large momentum in the wake. The momentum was rapidly lost by the diffusion in the near-wake field. The evaluated noise indicated that the noise level of the DFN was lower in the far-wake field than the broadband noise level. These results imply that the sinusoidal pressure fluctuation caused by the impingement of the jet-wake flow became weaker than the pressure fluctuation induced by the turbulence on the blade surface
ジカ熱流行期と流行後におけるベトナム健康人血清中のジカウイルスに対する中和抗体保有率の縦断的調査
Get PDF長崎大学学位論文 [学位記番号]博（医歯薬）甲第1264号 [学位授与年月日]令和2年9月18
Trypanosoma bruceiのASCT/SCSサイクルによるATPと酢酸産生
No full textAcetate:succinate CoA transferase (ASCT) is a mitochondrial enzyme that catalyzes the production of acetate and succinyl-CoA, which is coupled to ATP production with succinyl-CoA synthetase (SCS) in a process called the ASCT/SCS cycle. This cycle has been studied in Trypanosoma brucei (T. brucei), a pathogen of African sleeping sickness, and is involved in (i) ATP and (ii) acetate production and proceeds independent of oxygen and an electrochemical gradient. Interestingly, knockout of ASCT in procyclic form (PCF) of T. brucei cause oligomycin A-hypersensitivity phenotype indicating that ASCT/SCS cycle complements the deficiency of ATP synthase activity. In bloodstream form (BSF) of T. brucei, ATP synthase works in reverse to maintain the electrochemical gradient by hydrolyzing ATP. However, no information has been available on the source of ATP, although ASCT/SCS cycle could be a potential candidate. Regarding mitochondrial acetate production, which is essential for fatty acid biosynthesis and growth of T. brucei, ASCT or acetyl-CoA hydrolase (ACH) are known to be its source. Despite the importance of this cycle, direct evidence of its function is lacking, and there are no comprehensive biochemical or structural biology studies reported so far. Here, we show that in vitro–reconstituted ASCT/SCS cycle is highly specific towards acetyl-CoA and has a higher kcat than that of yeast and bacterial ATP synthases. Our results provide the first biochemical basis for (i) rescue of ATP synthase-deficient phenotype by ASCT/SCS cycle in PCF and (ii) a potential source of ATP for the reverse reaction of ATP synthase in BSF.長崎大学学位論文 学位記番号:博(医歯薬)甲第1283号 学位授与年月日:令和2年9月18日Author: Kota Mochizuki, Daniel Ken Inaoka, Muriel Mazet, Tomoo Shiba, Keisuke Fukuda, Hana Kurasawa, Yoann Millerioux, Michael Boshart, Emmanuel O. Balogun, Shigeharu Harada, Kenji Hirayama, Frédéric Bringaud, Kiyoshi KitaCitation: Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1861(11), art.no.148283; 202
