https://www.selleckchem.com/products/cyclophosphamide-monohydrate.html Nitrogen (N) is a crop macronutrient of major importance, which affects both plant growth and yield. In this paper we discuss the humus content (%) and various soluble N forms (NO 3-, total N, nitrate-N, ammonium-N, and organic nitrogen) available in humus sand soil samples originating from the Pallag Experimental Station of Horticulture at the University of Debrecen, Hungary. We found 45.4% nitrate-N and 13.8% nitrite-N of total N content present in the soil. Considering the percentage distribution of soluble N forms present at the Pallag Experimental Station, we recommend using this soil in further pot experiments, given that this has optimal nutrient supply capacity. In addition, we examined possible statistical correlations between humus% and N forms.The novel coronavirus pneumonia (COVID-19) is still in a serious situation. There is no specific therapeutic drug for COVID-19. At present, drugs, including lopinavir/ritonavir, chloroquine phosphate, abidol, IFN-α atomization and ribavirin, are commonly used in clinical practice. However, further clinical trials are needed to evaluate the efficacy and safety of these drugs. Other potential drugs that may be effective for COVID-19, are worthy of attention, including IL-6 monoclonal antibody, tyrosine protein kinase 1/2 inhibitor, cell therapy drugs, etc. This paper reviews these potential therapeutic drugs for COVID-19.Objective To establish a noninvasive method for measuring upper airway critical closing pressure (Pcrit), so as to evaluate collapsibility of the upper airway during sleep. Methods Pcrit was determined through the use of a noninvasive positive/negative pressure (CPAP/CPNP) ventilator(with independent intellectual property rights) during stageⅡ of non-rapid eye movement sleep. For the direct measurement, Pcrit was the pressure below which the upper airway occluded. For the indirect measurement, nasal pressure was plotted against max