Five state factors control progressive stages of freshwater salinization syndrome.

Factors driving freshwater salinization syndrome (FSS) influence the severity of impacts and chances for recovery. We hypothesize that spread of FSS across ecosystems is a function of interactions among five state factors: human activities, geology, flowpaths, climate, and time. (1) Human activities drive pulsed or chronic inputs of salt ions and mobilization of chemical contaminants. (2) Geology drives rates of erosion, weathering, ion exchange, and acidification-alkalinization. (3) Flowpaths drive salinization and contaminant mobilization along hydrologic cycles. (4) Climate drives rising water temperatures, salt stress, and evaporative concentration of ions and saltwater intrusion. (5) Time influences consequences, thresholds, and potentials for ecosystem recovery. We hypothesize that state factors advance FSS in distinct stages, which eventually contribute to failures in systems-level functions (supporting drinking water, crops, biodiversity, infrastructure, etc.). We present future research directions for protecting freshwaters at risk based on five state factors and stages from diagnosis to prognosis to cure.

Chronomodulated drug delivery system of urapidil for the treatment of hypertension.

INTRODUCTION: Hypertension is a disease which shows circadian rhythm in the pattern of two peaks, one in the evening at about 7pm and other in the early morning between 4 am to 8 am. Conventional therapies are incapable to target those time points when actually the symptoms get worsened. To achieve drug release at two time points, chronomodulated delivery system may offer greater benefits. MATERIALS AND METHODS: The chronomodulated system comprised of dual approach; immediate release granules (IRG) and pulsatile release mini-tablets (PRM) filled in the hard gelatin capsule. The mini-tablets were coated using Eudragit S-100 which provided the lag time. To achieve the desired release, various parameters like coating duration and coat thickness were studied. The immediate release granules were evaluated for micromeritical properties and drug release, while mini-tablets were evaluated for various parameters such as hardness, thickness, friability, weight variation, drug content, and disintegration time and in-vitro drug release. Compatibility of drug-excipient was checked by fourier transform infrared spectroscopy and Differential scanning calorimetry studies and pellets morphology was done by Scanning electron microscopy studies. RESULTS: The in-vitro release profile suggested that immediate release granules gives drug release within 20 min at the time of evening attack while the programmed pulsatile release was achieved from coated mini-tablets after a lag time of 9hrs, which was consistent with the demand of drug during early morning hour attack. Pellets found to be spherical in shape with smooth surface. Moreover compatibility studies illustrated no deleterious reaction between drug and polymers used in the study. CONCLUSIONS: The dual approach of developed chronomodulated formulation found to be satisfactory in the treatment of hypertension.