Preliminary investigation of saline water intrusion (SWI) and submarine groundwater discharge (SGD) along the south-eastern coast of Andhra Pradesh, India, using groundwater dynamics, sea surface temperature and field water quality anomalies.

Intensive anthropogenic activities along the coastal plains of Andhra Pradesh (such as urbanisation, agriculture and aquaculture) rely extensively on coastal fresh groundwater resources that are pumped at unsustainable rates causing groundwater decline and water quality problems due to saline water intrusion. Hydrogeological studies are imperative to implement groundwater conservation strategies in coastal Andhra Pradesh, which is experiencing a severe freshwater shortage due to overexploitation and saline water intrusion as well as clean water loss through the aquifer system close to the coastal plains. An attempt is made in this study to demarcate the submarine groundwater discharge (SGD) and saline water intrusion (SWI) zones adopting a three-tier validation system, i.e. groundwater dynamic, LANDSAT resultant sea surface temperature (SST) variance and site-specific water characteristics along the southeast coast of Andhra Pradesh, India. A total of 234 water samples (139 porewater, 31 groundwater and 64 seawater samples) were evaluated along ~ 450 km southeast coastline of Andhra Pradesh. In situ porewater physio-chemical parameters, i.e. EC, TDS, pH, DO, temperature, and salinity, at every 1 km except non-accessible areas and groundwater for every 5 km were analysed and used for identification of SGD zones in the study area. The hydraulic gradient values vary from - 11 to 250 m in post-monsoon and - 14 to 250 m in pre-monsoon. And sea surface temperature anomaly for 2017, 2018 and 2019 varies between 21-39 °C, 15-34 °C and 20-39 °C. Three districts out of the four districts studied (Krishna, Guntur and Nellore) were shown to be prone to SWI, whereas Prakasam district was susceptible for SGD. For the first time, this kind of preliminary study was carried out in the coastal Andhra Pradesh region, and it will serve as a basis for the meticulous analysis of the fresh and saline water mixing zones/process as well as to develop and manage the groundwater resources along the water-stressed coastal plains of Andhra Pradesh, India.

Professional-Grade TCA-Lactic Acid Chemical Peel: Elucidating Mode of Action to Treat Photoaging and Hyperpigmentation.

Chemical peeling is usually performed by dermatologists, plastic surgeons, and aestheticians for the treatment of photo-aged skin, dyspigmented skin, skin prone to acne eruption, and pre-cancerous skin lesions, etc. In this research paper, we report our investigative findings to understand the mode of action of a commercial professional chemical peel to treat hyperpigmented and photoaged skin. In the in-vitro experiments, we found that the peel inhibits enzymes that are responsible for degradation of collagen and elastin, and the production of melanin pigment. It was surprising to observe that trichloroacetic acid (TCA), which is considered a workhorse of chemical peels for its cauterant action, could synergistically promote the inhibitory action of lactic acid. The rationale behind this synergistic effect could be the conformational change in TCA from linear structure to ring-like structure, which was elucidated through sequential docking using Rosetta software. The in-vitro results on collagen and elastin were corroborated by up-regulation of COL1A, COL3B, fibronectin, and elastin gene expression from 3D human skin equivalents treated with the peel. The findings were further validated through ex-vivo testing on human skin biopsy. The peel significantly inhibits the production of total melanin, and ameliorates photo-damage that was evident through repair of the collagen in the skin exposed to a biological effective dose of UV daily light (6 J/cm2). These research findings have implications for product developers and users (dermatologists, plastic surgeons, and aestheticians) in improving safety and efficacy of chemical peels/peeling.