リュツォ・ホルム湾，プリンスオラフ海岸，及び，エンダビーランド地質調査隊報告2016-2017（JARE-58）

第58次日本南極地域観測隊（JARE-58）では，2016−2017の夏期期間にリュツォ・ホルム湾，プリンスオラフ海岸，及び，エンダビーランドにおいて地質調査をおこなった．調査隊のメンバーは，日本人地質研究者4名とアジア地域（タイ，インドネシア，モンゴル）の交換科学者3名で構成され，本吉隊長が一部期間の調査に加わった．第58次夏期観測では，「しらせ」搭載の2機の大型ヘリコプター（CH101）とともに観測隊チャーターの小型ヘリコプター（AS350）1機による野外調査の支援がなされた．本稿では，観測計画を実施するための，主に設営面での計画，準備，そして行動経過について報告する．The 58th Japanese Antarctic Research Expedition (JARE-58) conducted geological field surveys in the regions of Lützow-Holm Bay, Prince Olav Coast, and Enderby Land during the 2016−2017 austral summer season. The field party consisted of four Japanese geologists and three Asian geologists (Thai, Indonesian, Mongolian), and was joined periodically by JARE-58 expedition leader, Prof. Motoyoshi. Field parties were supported throughout the summer season by a smaller secondary helicopter (AS350) in addition to two main helicopters (CH101) stationed on the icebreaker Shirase. This report summarizes field preparations and the geological work undertaken, and highlights several key points for future planning and research

Regioselective Acetylation of Diols and Polyols by Acetate Catalysis: Mechanism and Application

We propose a principle for H-bonding activation in acylation of hydroxyl groups, where the acylation is activated by the formation of hydrogen bonds between hydroxyl groups and anions. With the guidance of this principle, we demonstrate a method for the selective acylation of carbohydrates. By this method, diols and polyols are regioselectively acetylated in high yields under mild conditions using catalytic amounts of acetate. In comparison to other methods involving reagents such as organotin, organoboron, organosilicon, organobase, and metal salts, this method is more environmentally friendly, convenient, and efficient and is also associated with higher regioselectivity. We have performed a thorough quantum chemical study to decipher the mechanism, which suggests that acetate first forms a dual H-bond complex with a diol, which enables subsequent monoacylation by acetic anhydride under mild conditions. The regioselectivity appears to originate from the inherent structure of the diols and polyols and their specific interactions with the coordinating acetate catalyst

H‑Bonding Activation in Highly Regioselective Acetylation of Diols

H-bonding activation in the regioselective acetylation of vicinal and 1,3-diols is presented. Herein, the acetylation of the hydroxyl group with acetic anhydride can be activated by the formation of H-bonds between the hydroxyl group and anions. The reaction exhibits high regioselectivity when a catalytic amount of tetrabutylammonium acetate is employed. Mechanistic studies indicated that acetate anion forms dual H-bonding complexes with the diol, which facilitates the subsequent regioselective monoacetylation

Effect of KGM/CS films, CS film and control on wound area contraction during 14 days (values are mean ± S.D., n = 6 observations in each group).

<p>Values are significant (^*) at P<0.05 and (^**) at P<0.01as compared to the control group.</p

The cross-section morphology of blending film with different KGM/CS ratio by SEM.

<p>The cross-section morphology of blending film with different KGM/CS ratio by SEM.</p

¹H-NMR spectra of DEX-GMA.

<p>(a), Morphology of nanoparticles observed by TEM (b) (A: blank nanoparticles, B: drug loaded nanoparticles), Particle size distribution from DLS analysis (c) (A: blank nanoparticles, B: drug loaded nanoparticles).</p

Schematic of derivatization of dextran and the free-radical mediated polymerization of the crosslinked polymer nanoparticles.

<p>Schematic of derivatization of dextran and the free-radical mediated polymerization of the crosslinked polymer nanoparticles.</p

In vitro cumulative release profile of Gentamicin.

<p>From Poly (DEX-GMA/AAc) nanoparticles (A) and GNPs-CS/KGM (B).</p

The water vapor transmission rate of different composition of CS/KGM films.

<p>Mean ± S.D. (n = 6).</p

Effect of GNPs-CS/KGM and control on wound area contraction during 14 days (values are mean ± S.D., n = 6 observations in each group).

<p>Values are significant (^*) at P<0.05 and (^**) at P<0.01as compared to the control group.</p