RESUMO
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, was first reported in December 2019 in Wuhan, Hubei province, China. It is now known as a pandemic and a global crisis due to rapid human-to-human transmission with the vast expansion that has affected almost all countries. The primary source of the disease is still unknown, but it is possible that the virus was transmitted through bat to an intermediate host and then to humans. The main and early symptoms of COVID-19 infection are fatigue, fever, dry cough, myalgia, and dyspnea. The incubation period of the disease is about 2-14 days, which is one of the important parameters for planning to prevent disease outbreak. PT-polymerase chain reaction test is used to diagnose the disease; chest computed tomography scan, chest X-ray, blood tests, and symptoms are also very helpful in diagnosing the disease. There is a strong emphasis on controlling infections and hand hygiene to prevent the transmission of the disease. There is not enough knowledge about this disease yet, and there are no specific vaccines or medications available to prevent and treat this disease. The current review study uses articles indexed on databases of Embase, Elsevier, PubMed, and World Health Organization and Centers for Disease Control and Prevention, and keywords of coronavirus, COVID-19, acute respiratory distress syndrome and China.
RESUMO
Cobalt oxide nanoparticles were prepared via green chemistry route and fully characterized by Field Emission Scanning Electron Microscope (FESEM), Energy-dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM) and Transmission electron microscopy (TEM) analyses; the CoO and Co3O4 nanoparticles, in sheet-shaped cobalt oxide form, ensued simultaneously in one step. The varying concentrations of NPs were analyzed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test on the cancer cell line (U87) which revealed that with increasing concentration of cobalt oxide nanoparticles, the survival rate of U87 tumor cells decreases; IC50 of nanoparticles being ~ 55 µg/ml-1.
Assuntos
Cobalto/química , Química Verde/métodos , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Óxidos/química , Antibacterianos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Magnetismo , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Nanomedicina/métodos , Extratos Vegetais , Rosmarinus , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Tensoativos , Temperatura , Sais de Tetrazólio/química , Tiazóis/química , Difração de Raios XRESUMO
In this study, CeO2 (cerium oxide) nanoparticles were synthesized using Pinus halepensis pollen and were characterized by field emission scanning electron microscopy (FESEM), powder X-ray diffraction (PXRD) and Raman spectroscopy. The results showed that the ensuing CeO2 nanostructures, ranging in size from 5 to 25 nm, had high porosity. Synthesized CeO2 showed the effective catalytic activity towards the photocatalytic removal of dyes. In this work, the photocatalytic activity to removal dye (methyl violet 2B), in the absence of UV radiation, using cerium dioxide nanoparticles (CeO2-NP) was determined. In this research, four main factors such as effect on color, concentration and pH were examined and maximum %R was obtained about was 97% in 75 min in presence of 50 mg of hydrogen peroxide.
