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Biomarkers in sweat are a largely untapped source of health information. Most of the currently available sweat harvesting and testing devices are incapable of operating under low-sweat rates such as those experienced by humans at rest. Here we analyze the in vitroand in vivosampling of sweat through osmosis viathe use of a hydrogel interfaced with the skin, without need for active perspiration. The hydrogel also interfaces with paper-based microfluidics to transport the fluid viacapillary forces toward a testing zone and then evaporation pad. We show that the hydrogel solute content and area of the evaporation pad regulate the long-term extraction of sweat and its associated biomarkers. The results indicate that the platform can sample biomarkers from a model skin system continuously for approximately 12 h. On-skin testing of the platform on both resting and exercising human subjects confirms that it can sample sweat lactate directly from the surface of skin. The results highlight that lactate in sweat increases with exercise and as a direct result of muscle activity. Implementation of such new principles for sweat fluid harvesting and management viawearable patch devices can contribute toward the advancement of next generation wearables.

•Mg-Al granulites and khondalites in the Bastar Craton-Eastern Ghats Belt interface.•Ultrahigh-temperature peak metamorphic conditions along a clockwise P-T path.•Mg-Al granulites record decompression-cooling from 8.5 kbar, 925 °C to 5.5kbar, 770 °C.•Texturally controlled in-situ monazite dating reveal two distinct age populations.•Tonian age amalgamation of the Bastar Craton with the EGP and subsequent reworking.

Major and trace element analyses of monazite by electron probe microanalyzer (EPMA) are routinely carried out for several decades. U–Th–total Pb method of monazite dating is currently considered as a reliable and acceptable tool to decipher the time of geological events. The purpose of the present study is to establish the quantification conditions of monazite chronology using SXFive tactis EPMA, recently installed at the National Centre for Earth Science Studies, Thiruvananthapuram, India. Consistency in the chemical-chronological data of the monazites starting from the chronologically well-constrained Maocyr monazite data followed by the analysis of monazite from the garnet-cordierite gneiss of the Kerala Khondalite Belt confirms the reliability of the NCESS-EPMA facility for the U–Th–total Pb chemical age dating of monazite. By applying the same analytical setup of chemical dating, the monazites from metapelites of Madurai Block of Southern Granulite Terrain, India yield two peak ages in probability density diagram of ca. 505 Ma and ca.590 Ma (23 spots) which is similar to the 206Pb/238U age (ca. 506 Ma and ca.585 Ma; 34 spots) obtained by LA-ICPMS.

Several letters to the editor are presented in response to articles in previous issues, including one on raising children in a bilingual home, another on breastfeeding, and one on International Yoga day celebrations.