On the Number of π-Electrons Involved in Stepwise Cycloaddition Reactions.

The development of higher-order cycloadditions has mainly been restricted by the requisite usage of highly conjugated and reactive π-systems. Recent years have witnessed organocatalysis as a potent mediator for several of the challenges associated herein, rendering higher-order cycloadditions a legitimate option for achieving the selective construction of specific molecular scaffolds. These developments reinvigorate the efforts to try to understand the underlying principles for cycloadditions involving a higher number of π-electrons than the "classical" cycloadditions; how do we properly address the impact which the addition of further π-electrons have on the reactivity of a system? Herein, computational investigations of two model higher-order cycloaddition systems have been performed to try to provide insights on changes in energetic barriers induced by the presence of benzofusions in a position which is unobstructive to the reactivity.

Impact of arterial location, pressure wave indicators, and measurement devices on arterial form factor and mean and central arterial pressure.

Mean arterial pressure (MAP) is often estimated from cuff systolic (S) and diastolic (D) blood pressure (BP) using a fixed arterial form factor (FF, usually 0.33). If MAP is measured directly, a true FF can be calculated: FF = [MAP-DBP]/[SBP-DBP].

Isotope Effects Reveal the Catalytic Mechanism of the Archetypical Suzuki-Miyaura Reaction.

Experimental and theoretical C kinetic isotope effects (KIEs) are utilized to obtain atomistic insight into the catalytic mechanism of the Pd(PPh)-catalyzed Suzuki-Miyaura reaction of aryl halides and aryl boronic acids. Under catalytic conditions, we establish that oxidative addition of aryl bromides occurs to a 12-electron monoligated palladium complex (Pd-(PPh)). This is based on the congruence of the experimental KIE for the carbon attached to bromine (KIE = 1.

Organocatalytic Enantioselective Construction of Conformationally Stable C(sp)-C(sp) Atropisomers.

Nonbiaryl atropisomers are molecules defined by a stereogenic axis featuring at least one nonarene moiety. Among these, scaffolds bearing a conformationally stable C(sp)-C(sp) stereogenic axis have been observed in natural compounds; however, their enantioselective synthesis remains almost completely unexplored. Herein we disclose a new class of chiral C(sp)-C(sp) atropisomers obtained with high levels of stereoselectivity (up to 99% ee) by means of an organocatalytic asymmetric methodology.

Cardiovascular Health in a Single Community in Rural Haiti: A Cross-sectional Study.

Introduction: There is a growing burden of cardiovascular disease in low- and middle-income countries and assessment of cardiovascular health (CVH) may identify populations at risk for poor CVH.

Methods: Between July 2014 and August 2014, we performed a household survey from a convenience sample among adult community members in rural northern Haiti. We used a modified World Health Organization STEPwise approach to chronic disease questionnaire to capture self-reported data on tobacco, diet, physical activity, and diabetes, and measured blood pressure and body mass index.