Dependence of Finger Flexion Force on the Posture of the Nonperforming Fingers During Key Pressing Tasks
摘要:
The influence of different positions of the non-performing (idle) fingers on the maximal force contraction of flexion (master) fingers during key pressing tasks was investigated. Ten participants performed maximal voluntary flexion contractions with various combinations of the index, middle, ring, and little fingers while the idle fingers rested on or were lifted away from the supporting surface. The effect of idle finger posture on total finger force production of master fingers was dependent on finger combination. In general, force production by master fingers was higher when the idle fingers were lifted away from the supporting surface than when they rested on it. The average increase in total force production by master fingers caused by the lifting of idle fingers was +12.4% (from -8.3% to +30.2%). Force-production capability of individual master fingers can be facilitated (as high as 34.1%), unchanged, or depressed (as high as -29.0%) by lifting the idle fingers. The effect of idle finger posture on finger force production of master fingers led to changes in force deficit. Neural, anatomical, and mechanical factors might account for the dependence of finger flexion force of master fingers on the posture of the idle fingers.
alternatives to Wittig chem-istry are needed to construct olefins from carbonyl compounds, but none have been developed to-date. Here we report an atom-economical olefination of carbonyls via aldol-decarbonylative coupling of aldehydes using robust and recyclable supported Pd catalysts, producing only CO and H2O as waste. The reaction affords homocoupling of aliphatic al-dehydes, as well as heterocoupling
需要新的原子经济替代 Wittig 化学来从羰基化合物构建烯烃,但迄今为止还没有开发出来。在这里,我们报告了使用坚固且可回收的负载型 Pd 催化剂通过醛的醛醇-脱羰基偶联实现羰基的原子经济烯化,仅产生 CO 和 H2O 作为废物。该反应提供了脂肪族醛的同偶联,以及脂肪族和芳香族醛的杂偶联。计算可以深入了解反应的选择性和热力学。串联羟醛脱羰反应为探索新的羰基反应以构建烯烃打开了大门。
Alkylation of lithium trialkylalkynylborates with benzo-1,3-dithiolium fluroborate
作者:Andrew Pelter、Pushpa Rupani、Peter Stewart
DOI:10.1039/c39810000164
日期:——
Lithiumtrialkylalkynylborates react in a stereoselective fashion with benzo-1, 3-dithiolium fluoroborate to give vinylboranes which on oxidation yield protected 3-oxo-aldehydes and on hydrolysis give protected αβ-unsaturated aldehydes; the hydrolysis is highly selective giving rise eventually to stereospecifically defind αβ-unsaturated aldehydes by a novel process.
characterized in terms of GC, MS, and NMR data. The sensory properties of the odorants, such as odor quality and odor detection threshold value, were determined with a trained panel. Structure-activityrelationships are discussed, suggesting that the 1,3-oxygen-sulfur functionality, required for the "olfactophore" of tropical/vegetable notes, can further be extended to the acetylthio derivatives.
Five new bulky moiety-modified analogues of the sandalwood odorant Polysantol® have been synthesized by aldol condensation of appropriate aldehydes with butanone, deconjugative α-methylation of the resulting α,β-unsaturated ketones, and reduction of the corresponding β,γ-unsaturated ketones. The final compounds were evaluated organoleptically and one of them seemed to be of special interest for its natural sandalwood scent.
[DE] CO-TENSIDE MIT UNGESÄTTIGTEN HETEROCYCLISCHEN KOPFGRUPPEN<br/>[EN] COSURFACTANTS COMPRISING UNSATURATED HETEROCYCLIC HEAD GROUPS<br/>[FR] COTENSIOACTIFS A TETES POLAIRES HETEROCYCLIQUES INSATUREES
申请人:BASF AG
公开号:WO2004065373A1
公开(公告)日:2004-08-05
Die vorliegende Erfindung betrifft Verbindungen mit ungesättigten heterocyclischen Kopfgruppen, Verfahren zur Herstellung der erfindungsgemässen Verbindungen durch Umsetzung von Aldehyden oder Carbonsäuren bzw. deren Derivaten mit polyfunktionellen Verbindungen, die mindestens eine Aminofunktion und mindestens eine weitere Funktion aus der Gruppe der Hydroxyl-, Diol-, Amino- und Carboxylfunktionen aufweisen, deren Verwendung als Co-Tenside sowie Haushaltswaschmittel, Haushaltsreiniger, Körperreinigungsmittel oder Körperpflegemittel enthaltend mindestens eine erfindungsgemässe Verbindung.