Large-Scale Synthesis of Nanosilica from Silica Sand for Plant Stimulant Applications.

Nanosilica is a versatile nanomaterial suitable as, e.g., drug carriers in medicine, fillers in polymers, and fertilizer/pesticide carriers and potentially a bioavailable source of silicon in agriculture. The enhanced biological activity of nanosilica over quartz sand has been noted before; it is directly related to the altered physicochemical properties of the nanoparticles compared to those of the bulk material. Therefore, it is feasible to use nanosilica as a form of plant stimulant. Nanosilica synthesis is a relatively cheap routine process on the laboratory scale; however, it is not easily scalable. Largely for this reason, studies of nanosilica fertilizers are scarce. This study will focus on industrial-scale silica nanoparticle production and the application of nanosilica as a plant stimulant in maize. A variant of the sol-gel method is used to successfully synthesize nanosilica particles starting from silica sand. The resulting particles are in the size range of 16-37 nm with great purity. The potential of nanosilica as a plant stimulant is demonstrated with the increased quantity and quality of maize crops.

The Level of Expression of Anxiety and Depression in Clinical Health Care Workers during the COVID-19 Outbreak in 2 Hospitals in Hanoi, Vietnam.

The disease caused by the SARS-Cov 2 virus has spread to most areas of the world with high rates of infection and deaths. Facing the complicated developments of the epidemic, clinical medical staff (CMS) are at risk of suffering psychological pressure. This study aimed to investigate the situation of anxiety, depression, and related factors affecting CMS during the COVID-19 pandemic at Dong Da General Hospital and Dong Anh General Hospital in Hanoi. A cross-sectional study was conducted from April to July 2020 using self-administered questionnaires amongst 341 CMS. The participants' anxiety levels were assessed using the standardized General Anxiety Disorder-7 (GAD-7) toolkit and levels of depression expression were assessed based on the standardized Patient Health Questionnaire-9 (PHQ-9) toolkit. Of the CMS who completed the questionnaire, 33.1% had an anxiety disorder and 23.2% exhibited mild to very severe depression. The factors associated with anxiety and depression were department of work, shortage of human resources, and discrimination from the community that directly affects the family of the CMS. The study results highlight the need for a training session to equip CMS with the skills required to cope with psychological stress in all circumstances in general and during the pandemic in particular. This training is especially important for those working in at-risk departments which are susceptible to infection.