Recent advances on synthesis of C-glycosides.

In recent years, C-glycosides have emerged as significant building blocks for many naturally occurring alkaloids and pharmaceutically active drug molecules. Therefore, significant efforts have been devoted to the construction of structurally important C-glycosidic linkages in carbohydrate compounds. Herein, we have summarized the recent developments of diverse synthesis of C-glycoside core between the time period from 2019 to 2022 focusing on different catalytic strategies, such as (i) transition-metal, and (ii) metal-free catalytic approaches. Further, the transition metal catalyzed C-glycosylations have been categorized into four sub classes: (a) metal based C-H activation, (b) cross-coupling reaction, (c) glycosyl radical intermediate-based process, and (d) Others.

TIRF microscopy with ultra-short penetration depth.

Total internal reflection fluorescence microscopy (TIRF), in both commercial and custom-built configurations, is widely used for high signal-noise ratio imaging. The imaging depth of traditional TIRF is sensitive to the incident angle of the laser, and normally limited to around 100 nm. In our paper, using a high refractive index material and the evanescent waves of various waveguide modes, we propose a compact and tunable ultra-short decay length TIRF system, which can reach decay lengths as short as 19 nm, and demonstrate its application for imaging fluorescent dye-labeled F-actin in HeLa cells.

Adding a new dimension to cardiac nano-architecture using electron microscopy: coupling membrane excitation to calcium signaling.

Advances in microscopic imaging technologies and associated computational methods now allow descriptions of cellular anatomy to go beyond 2-dimensions, revealing new micro-domain dynamics at unprecedented resolutions. In cardiomyocytes, electron microscopy (EM) first described junctional membrane complexes between the sarcolemma and sarcoplasmic reticulum over a half-century ago. Since then, 3-dimensional EM technologies such as electron tomography have become successful in determining the realistic nano-geometry of membrane junctions (dyads and peripheral junctions) and associated structures such as transverse tubules (T-tubules, aka. T-system). Concomitantly, super-resolution light microscopy has gone beyond the diffraction-limit to determine the distribution of molecules, such as ryanodine receptors, with 10(-8) meter (10nm) order accuracy. This review provides the current structural perspective and functional interpretation of membrane junction complexes, which are the central machinery controlling cardiac excitation-contraction coupling via calcium signaling.