ABSTRACT
With the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the incidence of coronavirus disease (COVID-19) increases each day. To date, there is no specific anti-SARS-CoV-2 drug. The usual approach to treating COVID-19 is treating its symptoms. However, this approach is limited by the different conditions of each area. We treated a 57-year-old man who was initially diagnosed with a severe type of the infection, but he progressed to a critical condition and eventually died. We learned valuable lessons from this case. The first lesson is the need to use immediate invasive mechanical ventilation if there is no obvious improvement after using non-invasive ventilation for several hours, which directly affects the prognosis. Another lesson is the risk involved in transferring severe COVID-19 patients. In the process of transfer, various threats may be encountered at any time. Thus, accurate assessment of the patient's condition and strict medical conditions are highly required. During the patient's 25-day treatment, we performed cardiopulmonary resuscitation twice. Currently, many patients require invasive mechanical ventilation and transfer to a superior hospital. We hope our findings will provide some advice and help for treating severe and critical COVID-19 cases.
ABSTRACT
Three kinds of nano-silver colloids have been prepared by electrolysis of silver rod using sodium citrate solution and AgNO3 mixed with polyvinyl alcohol solution as electrolyte and applying 7 V direct current for one hour. Nano-silver colloids have been investigated by means of TEM, absorption spectrum, electrophoresis experiment and SERS. The particle size ranges roughly from 20 nm to 25 nm (spheroid) for sample 1, from 20 nm to 35 nm (spheroid) for sample 2, and from 30 to 80 (many-sided) for sample 3, featuring absorption maximum at 404, 421 and 434 nm, respectively. The surface charge of these three kinds of colloidal silver particles is positive. In order to test if these nano-silver colloids can be used for SERS research, the cationic molecular fuchsine basic, methylene blue, anionic molecular benzoic acid, methyl orange, neutral molecular alcidine orange, and Sudan red were used. It was found that these nano-silver colloids have strong SERS activity. Furthermore, the nano-silver colloids that used AgNO3 mixed with polyvinyl alcohol solution as electrolyte has the strongest SERS activity among all the tested molecules. The SERS of methyl orange has been obtained on the nano-silver colloids, which has not been obtaind on the colloids prepared by electrolysis of silver rod using sodium citrate solution and on the gray and yellow silver colloids prepared by traditional means. The possible reason has been explained. One major advantage of this method (using AgNO3 mixed with polyvinyl alcohol solution as electrolyte) is the absence of the spectral interference.
