SARS-CoV-2 pandemic is one of the most critical pandemics during human civilization. Several therapeutic strategies for COVID-19 management have been offered; nonetheless, none of them seems to be sufficiently beneficial. In effect, vaccines have been proffered as a viable option. The critical issue now is to concentrate on protecting individuals against illness through immunization. One of the causes for concern among the researchers, physicians, and generally the whole community from the onset of vaccination has been the adverse effects (specifically blood clots) that may be observed after the injection of the COVID-19 vaccine. In some countries, such concerns have even resulted in the temporary or permanent discontinuation or abandonment of the application of some vaccines (especially AstraZeneca and Janssen). By evaluating rigorous studies published on this subject, the present article is aimed at identifying the association between blood clot incidence and COVID-19 vaccination. Various methods for producing the COVID-19 vaccines are analyzed, along with their possible pros and cons as well as common and rare side effects, especially VITT and blood clots. Finally, the differences of various vaccines on thrombotic events, WHO recommendations for VITT treatment, and blood clots statics are discussed.

In the present work, the cathodic stripping voltammetric methodology using a hanging mercury drop electrode was described for simultaneous determination of lead and zinc in different real samples. The method is based on adsorption of metal ions on mercury electrode using carbidopa as a suitable complexing agent. The potential was scanned to the negative direction and the differential pulse stripping voltammograms were recorded. Optimal conditions were found to be: accumulation time; 70 s, accumulation potential; 50 mV versus Ag/AgCl, scan rate; 40 mV s À1, supporting electrolyte; 0.01 M ammonia buffer at pH 8.5, and concentration of carbidopa; 8.0 mM. The relationship between the peak current versus concentration was linear over the range of 0.1 -210 and 0.2 -170 nM for lead and zinc, respectively. The detection limits are 0.09 and 0.15 nM for lead and zinc ions respectively. The relative standard deviations at a concentration level of 70 nM of both metal ions are found 1.08 and 1.24% for lead and zinc ions respectively.

Background: 2, 4-Dichlorophenoxyacetic acid (2, 4-D) is a widely used herbicide known to be moderately toxic. Extensive use and poor biodegradability of 2, 4-D has resulted in its ubiquitous presence in the environment, and has led to contamination of surface and ground waters. Objectives: At present study, single-walled carbon nanotubes (SWCNTs) were used for the sorption of 2, 4-D from aqueous solutions. Materials and Methods:The effect of various operating parameters such as initial concentration of 2, 4-D, contact time, adsorbent dosage, and pH were investigated. Equilibrium isotherms were used to identify the possible mechanism of the adsorption process. Results: Maximum adsorption capacity of the SWCNTs was 979.6 mg/g at pH5, contact time 45 min, initial concentration of 5000 µg/L, and 23 ± 2 •C temperatures, when 97.96% of 2, 4-D herbicide were removed. The adsorption equilibriums were analyzed by Langmuir and Freundlich isotherm models. It was found that the data fitted to Langmuir (R2 = 0.9987) better than Freundlich (R2 = 0.9727) model. Conclusions: According to achieved results, it was defined that SWCNTs is a quite effective adsorbent in removal of 2, 4-D from aqueous environments.

The spectrophotometric behavior of uranium (VI) with L-3-(3, 4-dihydroxy phenyl) alanine (LDOPA) reagent revealed that the uranium can form a ML 2 complex with LDOPA in solution. Thus a highly sensitive adsorptive stripping voltammetric protocol for measuring of trace uranium, in which the preconcentration was achieved by adsorption of the uranium-LDOPA complex at hanging mercury drop electrode (HMDE), is described. Optimal conditions were found to be a 0.02 M ammonium buffer (pH 9.5) containing 2.0 Â 10 À5 M (LDOPA), an accumulation potential of À0.1 V (versus Ag=AgCl) and an accumulation time of 120 sec.The peak current and concentration of uranium accorded with linear relationship in the range of 0.5-300 ng ml À1 . The relative standard deviation (at 10 ng ml À1 ) is 3.6% and the detection limit is 0.27 ng ml À1 . The interference of some common ions was studied. Applicability to different real samples is illustrated. The attractive behavior of this reagent holds great promise for routine environmental and industrial monitoring of uranium.