检索结果-南通市图书馆

The Compatibility of Groups Used to Protect Phenolic Functionality during Oxone-Mediated Oxidative Esterification

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green and Sustainable Chemistry 2022年第4期12卷 83-90页

作者： Tomoko Mineno Yuki Suzuki Tomoya Nobuta Daiki Takano hisao kansui Laboratory of Medicinal Chemistry Faculty of Pharmacy Takasaki University of Health and Welfare Takasaki Japan Laboratory of Molecular Design Chemistry Faculty of Pharmacy Takasaki University of Health and Welfare Takasaki Japan Laboratory of Organic Chemistry Faculty of Pharmaceutical Sciences Sojo University Kumamoto Japan

Protecting groups often play an essential role in organic synthesis, particularly for multi-step synthesis or natural product total synthesis. Various protecting groups areavailable to mask the vulnerable functionality;phenolic hydroxy groups are noteworthy examples, but their stability differs when protected. Herein, the compatibility of protective phenolic functionality was investigated with the implementation of indium (III) triflate-catalyzed oxidative esterification using Oxone in methanol. A wide range of protective moieties was selected and subjected to Oxone-mediated oxidative esterification. For example, sulfonates were found to be sufficiently stable and inert whereas acetals were susceptible to reaction conditions. The details of this investigation are provided.

关键词： Compatibility Protecting Groups Phenolic Functionality Oxone Oxidative Esterification

Oxone-Mediated Preparation of Ester Derivatives Using Indium(III) Triflate and Various Alcohols

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green and Sustainable Chemistry 2022年第1期12卷 1-8页

作者： Tomoko Mineno Daiki Takano Saika Komiya Azusa Sato hisao kansui Laboratory of Medicinal Chemistry Faculty of Pharmacy Takasaki University of Health and Welfare Takasaki Gunma Japan Laboratory of Organic Chemistry Faculty of Pharmaceutical Sciences Sojo University Ikeda Kumamoto Japan

Esters are known as one of the most fundamental chemical moieties and also essentially useful components, especially for medicinal agents. Herein, using benzaldehyde and its derivatives as starting materials, Oxone-mediated preparation of ester derivatives in the presence of a catalytic amount of indium(III) triflate is described. Alcohols with various chain lengths, which functioned as solvents and substrates, were examined. Overall, the oxidative esterification starting with benzaldehyde derivatives possessing electron withdrawing groups proceeded smoothly and gave sufficient yields, in comparison to the reactions with the derivatives having electron donating groups.

关键词： Oxone Oxidative Esterification Benzaldehyde Derivatives Ester Derivatives Indium(III) Triflate Alcohols

Highly-Efficient Conversion of Primary Amides to Nitriles Using Indium(III) Triflate as the Catalyst

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Organic Chemistry 2014年第1期4卷 1-6页

作者： Tomoko Mineno Mamika Shinada Kazuki Watanabe Hitoshi Yoshimitsu Hiroyuki Miyashita hisao kansui Laboratory of Medicinal Chemistry Faculty of Pharmacy Takasaki University of Health and Welfare Takasaki Japan Laboratory of Natural Medicines Faculty of Pharmaceutical Sciences Sojo University Kumamoto Japan Laboratory of Organic Chemistry for Life Sciences Faculty of Pharmacy Takasaki University of Health and Welfare Takasaki Japan Laboratory of Organic Chemistry Faculty of Pharmaceutical Sciences Sojo University Kumamoto Japan

Indium(III) triflate, a trivalent indium reagent, was shown to be a highly-efficient catalyst for the conversion of primary amides to the corresponding nitriles. The successful reactions required 5 mol% of indium(III) triflate, and toluene was proved to be the most suitable solvent. Various amides were subjected to this method, and each produced the corresponding nitriles in excellent yields.

关键词： Indium(III) Triflate Primary Amides Nitriles

Effect of rubrene:P3HT bilayer on photovoltaic performance of perovskite solar cells with electrodeposited ZnO nanorods

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2018年第2期27卷 455-462页

作者： Christian Mark Pelicano hisao Yanagi Graduate School of Materials Science Nara Institute of Science and Technology

Improved photovoltaic performance of perovskite solar cells is demonstrated through the synergistic effect of electrodeposited ZnO nanorods and rubrene：P3HT bilayer as electron and hole-transporting layers,respectively. Highly crystalline ZnO nanorods were obtained by electrochemical deposition in a chloride medium. Additionally, rubrene interlayer was able to passivate or cover the grain boundaries of perovskite film effectively that led to reduced leakage current. A perovskite solar cell optimized with ZnO nanorods and rubrene：P3HT bilayer achieved a maximum efficiency of 4.9% showing reduced hysteresis behavior compared with the device having P3HT as the only hole-transporting layer. The application of longer nanorods led to better perovskite infiltration and shorter charge carrier path length. These results highlight the potential of electrodeposited ZnO nanorods and rubrene：P3HT bilayer as charge selective layers for efficient perovskite solar cells.

关键词： Rubrene:P3HT bilayer Electrodeposited ZnO nanorods Perovskite solar cells

Dm-KDE： dynamical kernel density estimation by sequences of KDE estimators with fixed number of components over data streams

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2014年第4期8卷 563-580页

作者： Min XU hisao ISHIBUCHI Xin GU Shitong WANG School of Digital Media Jiangnan University Wuxi 214122 China School of Internet of Things Technology Wuxi Institute of Technology Wuxi 214121 China Department of Computer Science Osaka Prefecture University Osaka 599-8531 Japan

In many data stream mining applications, traditional density estimation methods such as kemel density estimation, reduced set density estimation can not be applied to the density estimation of data streams because of their high computational burden, processing time and intensive memory allocation requirement. In order to reduce the time and space complexity, a novel density estimation method Dm-KDE over data streams based on the proposed algorithm m-KDE which can be used to design a KDE estimator with the fixed number of kernel components for a dataset is proposed. In this method, Dm-KDE sequence entries are created by algorithm m-KDE instead of all kemels obtained from other density estimation methods. In order to further reduce the storage space, Dm-KDE sequence entries can be merged by calculating their KL divergences. Finally, the probability density functions over arbitrary time or entire time can be estimated through the obtained estimation model. In contrast to the state-of-the-art algorithm SOMKE, the distinctive advantage of the proposed algorithm Dm-KDE exists in that it can achieve the same accuracy with much less fixed number of kernel components such that it is suitable for the scenarios where higher on-line computation about the kernel density estimation over data streams is required. We compare Dm-KDE with SOMKE and M-kernel in terms of density estimation accuracy and running time for various stationary datasets. We also apply Dm-KDE to evolving data streams. Experimental results illustrate the effectiveness of the pro- posed method.

关键词： kernel density estimation Kullback-Leibler di- vergence data streams kernel width time and space complexity

Cathodoluminescence of diamond synthesized from silicon-carbide

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1996年第3期41卷 208-212页

作者：洪时明 KANDA hisao 芶立 National Institute for Research in Inorganic Materials Namiki 1-1 Tsukuba Ibaraki 305 Japan

As a wide energy gap semiconductor, diamond is expected to play a role in UV light-emitting diode or laser. However, the impurities and vacancies in diamond exert a great influence on optical properties of the crystals. It is important, therefore, to study the relation between impurities and the optical properties, and furthermore, to study the control of the impurities.

关键词： high pressure synthesis diamond cathodoluminescence optical centre.

Survivin expression in early hepatocellular carcinoma and post-treatment with anti-cancer drug under hypoxic culture condition

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第40期13卷 5306-5311页

作者： Satoshi Mamori Tadashi Asakura Kiyoshi Ohkawa hisao Tajiri Division of Gastroenterology and Hepatology Department of Internal MedicineThe Jikei University School of MedicineTokyo 105-8461Japan Department of Biochemistry 1 The Jikei University School of MedicineTokyo 105-8461Japan

AIM： To investigate the expression of survivin during the early stages of hepatocellular cardnoma （HCC）.METHODS： Immunohistochemical expression of survivin in liver tumor and non-tumor tissue specimens taken from 17 patients was compared. In addition, to determine the survivin expression in response to anticancer drugs in early stage HCC, the survivin expression was determined after the treatment of the HCC cells with anti-cancer drugs under hypoxic culture conditions.RESULTS： Survivin proteins were expressed in 64.7% of cells in early HCC specimens. A correlation between the survivin expression rate in the peritumoral hepatocytes and the rate of expression in the HCC specimens （low-rate group vs high-rate group） was observed. The survivin protein concentration in HCC cells was increased by the combination of hypoxia and anti-cancer drugs.CONCLUSION： This study suggests that survivin could be used as a therapeutic target in early HCC.

关键词： Survivin Hepatocellular carcinoma Hypoxia

Impairment of secondary peristalsis in Barrett's esophagus by transnasal endoscopy-based testing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2014年第3期20卷 822-828页

作者： Go Kobayashi Mitsuru Kaise Hiroshi Arakawa hisao Tajiri Department of Gastroenterology and Hepatology Jikei University Daisan Hospital Department of Gastroenterology Toranomon Hospital Department of Endoscopy Jikei University Kashiwa Hospital Department of Gastroenterology and Hepatology Jikei University School of Medicine

AIM: To investigate dysfunctions in esophageal peristalsis and sensation in patients with Barrett’s esophagus following acid infusion using endoscopy-based testing.

关键词： Barrett’ s esophagus, Transnasal endoscopy, Acid infusion test, Esophageal sensation, Secondary peristalsis

Gastroesophageal flap valve status distinguishes clinical phenotypes of large hiatal hernia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第47期16卷 6010-6015页

作者： Haruka Kaneyama Mitsuru Kaise Hiroshi Arakawa Yoshinori Arai Keisuke Kanazawa hisao Tajiri Department of Endoscopy The Jikei University School of Medicine Department of Gastroenterology and Hepatology The Jikei University School of Medicine

AIM: To investigate two distinct clinical phenotypes of reflux esophagitis and intra-hernial ulcer (Cameron lesions) in patients with large hiatal hernias. METHODS: A case series study was performed with 16 831 patients who underwent diagnostic esophagogastroduodenoscopy for 2 years at an academic referral center. A hiatus diameter ≥ 4 cm was defined as a large hernia. A sharp fold that surrounded the cardia was designated as an intact gastroesophageal flap valve (GEFV), and a loose fold or disappearance of the fold was classified as an impaired GEFV. We studied the associations between large hiatal hernias and the distinct clinical phenotypes (reflux esophagitis and Cameron lesions), and analyzed factors that distinguished the clinical phenotypes. RESULTS: Large hiatal hernias were found in 49 (0.3%) of 16 831 patients. Cameron lesions and reflux esopha-gitis were observed in 10% and 47% of these patients, and 0% and 8% of the patients without large hiatal hernias, which indicated significant associations between large hiatal hernias and these diseases. However, there was no coincidence of the two distinct disorders. Univariate analysis demonstrated significant associations between Cameron lesions and the clinico-endoscopic factors such as nonsteroidal anti-inflammatory drug (NSAID) intake (80% in Cameron lesion cases vs 18% in non-Cameron lesion cases, P=0.015) and intact GEFV (100% in Cameron lesion cases vs 18% in non-Cameron lesion cases, P=0.0007). In contrast, reflux esophagitis was linked with impaired GEFV (44% in reflux esophagitis cases vs 8% in non-reflux esophagitis cases, P = 0.01). Multivariate regression analysis confirmed these significant associations. CONCLUSION: GEFV status and NSAID intake distinguish clinical phenotypes of large hiatal hernias. Cameron lesions are associated with intact GEFV and NSAID intake.

关键词： Large hiatal hernia Reflux esophagitis Cameron lesion Gastroesophageal flap valve Nonsteroidal anti-inflammatory drug