Relative reactivity of alkenyl alcohols in the palladium-catalyzed redox-relay Heck reaction

The relative rates of alkenyl alcohols in the Pd-catalyzed redox-relay Heck reaction were measured in order to examine the effect of their steric and electronic properties on the rate-determining step. Competition experiments between an allylic alkenyl alcohol and two substrates with differing chain lengths revealed that the allylic alcohol reacts 3–4 times faster in either case. Competition between di- and trisubstituted alkenyl alcohols provided an interesting scenario, in which the disubstituted alkene was consumed first followed by reaction of the trisubstituted alkene. Consistent with this observation, the transition structures for the migratory insertion of the aryl group into the di- and trisubstituted alkenes were calculated with a lower barrier for the former. An internal competition between a substrate containing two alcohols with differing chain lengths demonstrated the catalyst's preference for migrating toward the closest alcohol. Additionally, it was observed that increasing the electron-density in the arene boronic acid promotes a faster reaction, which correlates with Hammett [sigma-rho] values to give a [rho] of −0.87

Fast and Protecting-Group-Free Synthesis of (±)-Subincanadine C

The first total synthesis of (±)-subincanadine C has been accomplished in a protecting-group-free fashion. This pentacyclic indole alkaloid was synthesized in six steps from the known intermediate <b>4</b>, featuring Ni(COD)₂-mediated intramolecular Michael addition as a key transformation

Fast and Protecting-Group-Free Synthesis of (±)-Subincanadine C

The first total synthesis of (±)-subincanadine C has been accomplished in a protecting-group-free fashion. This pentacyclic indole alkaloid was synthesized in six steps from the known intermediate <b>4</b>, featuring Ni(COD)₂-mediated intramolecular Michael addition as a key transformation

Oral palatal wound closure and serum corticosterone levels.

<p>(A) Closure of palatal wounds was significantly slower in isolated rats (ISO) than in group-housed rats (GRO). Compared with group-housed rats, a lower proportion of wounds were closed on days 7 and 8 in isolated rats (n=10/group; * <i>p</i><0.05, ** <i>p</i><0.01). (B) Serum corticosterone levels were significantly higher in isolated rats on days 1, 3 and 5 as compared to controls (n=5/group; * <i>p</i><0.05). BL: baseline.</p

Expression levels of healing-associated genes in isolated (ISO) and group-housed (GRO) rats on Days 1, 3 and 5 post-wounding.

<p>(A) IL1β; (B) MIP1α; (C) FGF7; (D) TNFα; and (E) VEGFA. Error bars represent SEM. * indicates a significant difference between stress conditions. ^# and ⁺ indicate significant differences between days within group-housed and isolated rats, respectively (n=10/group; *, ^#, ⁺, <i>p</i><0.05; **, ^{+ +}, ^##<i>p</i><0.01; ^###<i>p</i><0.001).</p

Expression of miR-29 family members, miR-203 and SOCS3 mRNA in wounded tissues by qRT-PCR.

<p>Relative expression levels of miR-29 family members (A) and miR-203 (B) in isolated (ISO) rats are in comparison to control levels expressed as 1 on the graph. U6 was used as an internal reference. (C) SOCS3 mRNA relative expression, GAPDH was used as a reference gene. (n=10/group [ISO&GRO], * indicates a significant difference between stress conditions. * <i>p</i><0.05; ** <i>p</i><0.01).</p

Free Space Makes the Polymer “Dead Layer” Alive

The effect of free space on molecular motion inside the polymer “dead layer” or adsorbed nanolayers on solid surfaces is investigated. Free space is introduced into the nanolayer by choosing a polymer with a relatively big side group, poly n-butyl methacrylate (PnBMA), and polarization-resolved single-molecule fluorescence microscopy is adopted as the method. The rotational motion of the doped fluorescent probes is found to be considerably excited at moderate temperatures, attributed to the free space brought by the side group of the PnBMA. The development of the adsorbed nanolayer by the prolonged annealing of the parent film is carefully monitored, together with the evolution of the molecular motion and the glass transition temperature (Tg). The Tg values of the exposed nanolayers are considerably lower than that of the bulk system, while they become higher than those in the bulk situation when the nanolayer is covered with a polymer top layer. The experimental evidence has demonstrated that the free space made available by the side group and the air–polymer interface has considerably promoted the molecular motion inside the adsorbed nanolayers, even under the situation of overwhelming surface attraction

Total Synthesis of (±)-Cephalosol

A concise and efficient total synthesis of (±)-cephalosol has been completed (5 steps from known ester <b>5</b>, 39% overall yield), featuring a Cu(II)-promoted haloisocoumarin formation and sequential Suzuki cross-coupling/intramolecular oxo-Michael addition

Table_1_Accelerometer-measured physical activity and sample-based frailty in older women: does pattern really matter?.DOCX

BackgroundThe relationship between the patterns of physical activity (PA) and frailty, including its various subdomains, remains poorly understood. Therefore, this study aims to investigate the correlations between the patterns of physical activity and frailty and its various subdomains in community-dwelling older women.MethodsA cross-sectional study investigated the association between physical activity and frailty in 1,099 women aged between 60 to 70 years. Triaxial accelerometers were used to measure bouted PA (a minimum duration of 10 min) and sporadic PA (a duration of ResultsBouted moderate-to-vigorous PA (MVPA) and sporadic MVPA were associated with decreased odds of being prefrail and frail, and the optimal cutoff values were 6 and 19.7 for the prefrail stage and 6.6 and 19.4 min/day for the frail stage, respectively. Bouted light PA (LPA) was associated with decreased odds of being prefrail, and the optimal cutoff value was 170.2 min/day. Additionally, bouted and sporadic MVPA were associated with decreased odds of being slow and their optimal cutoff values were 5 and 19.1 min/day, respectively. Sporadic MVPA was associated with decreased odds of exhaustion, and the cutoff was 19.7 min/day. Bouted MVPA and LPA were associated with decreased odds of having low PA, and the cutoff values were 4.4 and 163.2 min/day, respectively.ConclusionAny MVPA, regardless of bout duration, could be used as a suitable PA program to improve and prevent frailty in older women, such as bouted MVPA (4–5 times/week) or sporadic MVPA (20 min/day). The improvement effect of bouted and sporadic MVPA on the frailty of older people may not be affected by the subdomain. Additionally, bouted LPA was suitable for the management of prefrailty.</p