260 research outputs found

    Synthesis of α-Trifluoromethylamines by Cu-Catalyzed Regio- and Enantioselective Hydroamination of 1-Trifluoromethylalkenes

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    A copper-catalyzed regioselective net hydroamination of 1-trifluoromethylalkenes with hydrosilanes and hydroxylamines has been developed. The judicious choice of ligand and additive suppresses the conceivable but undesired β-F elimination of an α-CF3-substituted organocopper intermediate, leading to targeted α-trifluoromethylamines in good yields with excellent regioselectivity. Additionally, with an appropriate chiral bisphosphine ligand, the enantioselective reaction is also possible to deliver optically active α-trifluoromethylamines of high potential in medicinal and pharmaceutical chemistry.Takata T., Hirano K., Miura M.. Synthesis of α-Trifluoromethylamines by Cu-Catalyzed Regio- and Enantioselective Hydroamination of 1-Trifluoromethylalkenes. Organic Letters. 21(11), 4284-4288, (2019),7 June 2019; © 2019 American Chemical Society. https://doi.org/10.102/acs.orglett.9b01471

    Synthesis of gem-difluoroalkenes by copper-catalyzed regioselective hydrodefluorination of 1-trifluoromethylalkenes

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    A copper-catalyzed regioselective hydrodefluorination of 1-trifluoromethylalkenes with hydrosilanes has been developed. The copper catalysis is compatible with several functional groups, including alkyl chloride, ether, ester, nitrile, and imide moieties, to form the corresponding gem-difluoroalkenes in good yields. Additionally, asymmetric induction is also possible by using the chiral DTBM-SEGPHOS ligand, and gem-difluoroalkene with point chirality at the allylic position is obtained with high enantioselectivity

    高齢者気管支喘息における気道過敏性と温泉療法

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    Clinical effects of spa therapy were examined in 150 patients with asthma in relation tobronchial hyperresponsiveness and patient age. 1. The efficacy rate of spa therapy was larger as the patient age was higher: the rate was 73.3% in patients under age 49, 81.8% in those between the ages of 50 and 59, 86.4% in those between the ages of 60 and 69, and 90.6% in those over age 70. The mean of efficacy rates was 83.3% in all subjects. 2. The bronchial hyperresponsiveness (BH) was lower as patient age was higher: the BH in patients between the ages of 60 and 69 and in those over age 70 was significantly lower compared to the BH in those under age 49 (p < O.OOl). 3. Clinical effects of spa therapy tended to be lower in patients with increased bronchial hyperresponsiveness. The bronchial hyperresponsiveness showed a tendency to decrease after spa therapy in whom the therapy was effective, however, the BH did not change in patients with slight or no efficacy during spa therapy.1.温泉療法では,年齢が高くなるほどその有効率も高くなると言う傾向が見られ、49才以下の症例では73.3% ,50-59才の症例では81.8% , 60-69才の症例では86.4% ,70才以上では90.6% であり,全症例の平均有効率は73.3% であった。  2.気道過敏性は,年齢が高くなるほど低下する傾向が見られ,60-69才および70才以上の症例の気道過敏性は,49才以下の症例と比べ有 意に低い値を示した(P < 0.001)。  3.温泉療法の臨床効果は,気道過敏性が強くなるにつれて低下する傾向が見られた。また,温泉療法の著効例や有効例では,治療により 気道過敏性が低下してくるが、やや有効例や無効例では,気道過敏性はほとんど変化しないことが示された

    Thermal conductivity of liquid/carbon nanotube core-shell nanocomposites

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    Hollow carbon nanotubes (CNTs) were impregnated with an ionic liquid, resulting in a composite core-shell nanostructure. Liquid infusion was verified by transmission electron microscopy and rigorous observations unveiled that the nanocomposite is stable, i.e., liquid did not evaporate owing to its low vapor pressure. A series of individual nanostructures were attached on T-type heat sensors and their thermal behavior was evaluated. The liquid core was found to reduce the thermal conductivity of the base structure, CNT, from ca. 28 W/mK to ca. 15 W/mK. These findings could contribute to a better understanding of nanoscale thermal science and potentially to applications such as nanodevice thermal management and thermoelectric devices

    Assessment of Myocardial Function During Mechanical Left Ventricular Support Using Serial Echocardiography: A Case Report

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    A 40-year-old man with valvular heart disease was successfully treated using a left ventricular assist device (LVAD) after open heart surgery. Echocardiography revealed left ventricular ejection fraction (LV-EF) at LVAD on/off: 23.4%/14.6% on the 4th, 23.8%/23.8% on the 5th, and 23.8%/26.8% on the 6th postoperative day (POD), respectively. The patient was weaned from LVAD on the 8th POD and discharged from the hospital on the 58th POD. The LV-EF improved to 54% 6 months after surgery and increased from 57% to 64% in response to exercise stress testing 1 year after surgery.</p

    サーモグラフィーによる体表面温度の測定 3.体表面温度の回復率と末消血流量との相関

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    The body surface peripheral circulation in 12 cases, including 9 patients with diabetes mellitus who were suffering coldness, numbness or pain in their feet, and 3 healthy volunteers was examined using Laser-Doppler blood flowmetry. At the same time, the body surface temperature was estimated by thermography. Thermographic results were analyzed quantitatively by calculating a recovery ratio as : Recovery ratio = [Total counts of thermography(Pixels) over temperature (T) after cold loading] ÷ [Initial counts over T before cold loading] x 100(%). The recovery ratio and the blood flow were correlated, r=0.68, p<O.01. The peripheral circulation of 16 patients with diabetes mellitus was observed at three different conditions including, l)placed at room temperature at 20℃for 15 min, 2) submerged and warmed for 5 min in a hot bath at 36℃(i.e. hot loading), and 3) submerged and cooled for 5 min in a water bath at 20℃ (i.e. cold loading). Three different baseline temperatures, 26℃, 27℃ and 28 ℃, were used in processing the thermographic results into pictures. The highest correlation (r=0.59, p=0.0002) was obtained under the condition of cold loading using a baseline temperature limitation of27℃.The difference ratio (%) of blood flow was calculated as the blood flow at cold loading divided by the blood flow at hot loading in these 16 patients. The difference ratio of the blood flow and the recovery ratio of thermography were correlated, r=0.46, p<O.OOO1. We found a strong correlation between the results of Laser-Doppler blood flowmetry and one of thermographic methods used to monitor peripheral circulation in patients with diabetes mellitus. Cold loading using a baseline temperature limitation of 27℃ were recommended for further examinations. Patients with low blood flow as well as with large differences in their peripheral circulation between cold loading and hot loading had severe coldness in their body surface temperature. We showed the usefulness of the results of thermography, when quantified by picture processing using computer software, in relation with the results of Laser-Doppler blood flowmetry.末梢神経障害を有する糖尿病患者の末梢循環障害の程度を数量的に検討する目的で、下肢に冷感ならびにしびれ感または疼痛を訴える糖尿病患者9症例と健常ボランティア3例の計12例(平均年齢59歳)についてサーモグラフィーを用いて体表面温度を測定した。更に,サーモグラフィーで得られた結果と末梢皮膚血流量をレーザードプラー血流計を用いて測定して得られた結果と比較した。サーモグラフィーによる測定で得られた結果は回復率として数量化して表示された。回復率の算出方法は回復率= [冷水負荷後の特定温度27℃以 上の体表面温度のサーモグラフィーのPixelの総数]÷ [冷水負荷前の特定温度27℃以上の体表面温度のサーモグラフィーのPixelの総数]×100%で求めた。レーザードプラ-血流計を用いて測定して得られた末梢血流量は左右それぞれ5カ所,計10カ所の測定値の平均で表示した。その結果,末梢皮膚温度の回復率と末梢皮膚の血流量との問には正の相関関係(r=0.68,p<0.01)が認められた。次に,末梢皮膚血流量について,室温20℃安静15分後,温水36℃浸水負荷10分後,冷水20℃浸水負荷30分後の異なる3条件について、またサーモグラフィーで得られた結果を,画像処理の過程で用いられた,26℃,27℃,28℃の3つの異なる特定温度との関連について検討を行なった。対象は,下肢に冷感ならびにしびれ感または疼痛を訴える糖尿病患者16症例(平均年齢69歳,平均HbAIC9.6%)について測定した。その結果,末梢皮膚 血流量は冷水20℃浸水負荷30分後に測定して得られた結果と,回復率は特定温度27℃で画像処理して得られた結果とが最も相関が高い(r=0.59,p=0.0002)ことが示された。`次に,相関が高い条件は,室温20℃安静15分後に血流量を測定した場合(r=0.483,p=0.0002)であった。そして温 水36℃浸水負荷10分後に測定して得られた結果とが最も相関関係が低い結果となった。更に,冷水20℃浸水負荷30分後に測定して得られた結果を温水36℃浸水負荷10分後に測定して得られた結果で割った比を%で表示したところ回復率とこの比との間には正の相関関係(r=0.46,p<0.0001)が認められた。このことから,温水36℃負荷時と,冷水20℃負荷時との差が大きい患者 において末梢皮膚温度の低下が著しいことが示された。これまで悲観血的に測定されてきたサーモグラフィーによる末梢循環の数量的評価の試みは,レーザー血流計による結果と組み合わせることで,両者の間に正の相関関係が示されたことにより,今後,数量化された客観的評価を可能にした

    Superstable Ultrathin Water Film Confined in a Hydrophilized Carbon Nanotube

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    Fluids confined in a nanoscale space behave differently than in the bulk due to strong interactions between fluid molecules and solid atoms. Here, we observed water confined inside "open" hydrophilized carbon nanotubes (CNT), with diameter of tens of nanometers, using transmission electron microscopy (TEM). A 1-7 nm water film adhering to most of the inner wall surface was observed and remained stable in the high vacuum (order of 10(-5) Pa) of the TEM. The superstability of this film was attributed to a combination of curvature, nanoroughness, and confinement resulting in a lower vapor pressure for water and hence inhibiting its vaporization. Occasional, suspended ultrathin water film with thickness of 3-20 nm were found and remained stable inside the CNT. This film thickness is 1 order of magnitude smaller than the critical film thickness (about 40 nm) reported by the Derjaguin-Landau-Verwey-Overbeek theory and previous experimental investigations. The stability of the suspended ultrathin water film is attributed to the additional molecular interactions due to the extended water meniscus, which balances the rest of the disjoining pressures
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