Regime shifts in trophic status and regional nutrient criteria for the Bohai Bay, China.

Identifying trophic status shift and developing nutrient criteria were considered important for controlling coastal eutrophication. Based on data from 1980 to 2018, we used sequential t-test analysis of regime shifts and assessment of coastal trophic status models to detect regime shifts in trophic status in Bohai Bay (China). We identified four distinct periods: unimpaired (1980-1984), minimally impacted (1985-1994), tipping point (1995-1999) and severely degraded (2000-2018). Using the reference conditions at different trophic status, a frequency distribution analysis was performed to develop candidate nutrient criteria. By considering other factors, such as the quantity and quality of data and long-term nutrient variations, we determined recommended criteria for dissolved inorganic nitrogen (15.3 µmol L-1) and phosphorus (0.42 µmol L-1) in Bohai Bay. This study provides a novel and feasible approach to determine reference conditions for the determination of nutrient criteria for coastal waters.

Update on treatment and preventive interventions against COVID-19: an overview of potential pharmacological agents and vaccines.

The outbreak of coronavirus disease 2019 (COVID-19) triggered by the new member of the coronaviridae family, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has created an unprecedented challenge for global health. In addition to mild to moderate clinical manifestations such as fever, cough, and fatigue, severe cases often developed lethal complications including acute respiratory distress syndrome (ARDS) and acute lung injury. Given the alarming rate of infection and increasing trend of mortality, the development of underlying therapeutic and preventive treatment, as well as the verification of its effectiveness, are the top priorities. Current research mainly referred to and evaluated the application of the empirical treatment based on two precedents, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), including antiviral drugs targeting different stages of virus replication, immunotherapy modulating the overactivated inflammation response, and other therapies such as herbal medicine and mesenchymal stem cells. Besides, the ongoing development of inventing prophylactic interventions such as various vaccines by companies and institutions worldwide is crucial to decline morbidity and mortality. This review mainly focused on promising candidates for the treatment of COVID-19 and collected recently updated evidence relevant to its feasibility in clinical practice in the near future.