Structural Requirements of 1-(2-Pyridinyl)-5-pyrazolones for Disproportionation of Boronic Acids

We observed an unusual formation of four-coordinate boron(III) complexes from the reaction of 1-(2-pyridinyl)-5-pyrazolone derivatives with arylboronic acids in the basic media. The exact mechanism is not clear; however, the use of unprotected boronic acid and the presence of a bidentate ligand appeared to be the key structural requirements for the transformation. The results suggest that base-promoted disproportionation of arylboronic acid with the assistance of the [N,O]-bidentate ligation of 1-(2-pyridinyl)-5-pyrazolone should take place and facilitate the formation of pyrazole diarylborinate. Experiments to obtain a deeper understanding of its mechanism are currently underway.

Unusual paraseptal emphysema as the primary changes in computerized tomography scan of a COVID-19 patient. Case report

Covid-19 pandemic has infected more than 20 million people worldwide and claimed more than 750,000 lives so far. Given that this disease is new, the long-term lung effects for survivors especially of severe cases are unknown. Most radiographic changes compared to those commonly seen in Acute Respiratory Distress Syndrome (ARDS), manifested as groundglass opacities or diffuse interstitial/alveolar changes. We present a case of severe acute respiratory failure secondary to COVID-19 requiring prolonged mechanical ventilation and hospitalization with subsequent lung damage and unusual formation of extensive paraseptal emphysematous changes which predominantly affect the lungs apices with subsequent spontaneous pneumothorax. Currently, the long-term impacts on survivors of severe COVID-19 infections are unknown. Future long-term follow-up studies will likely confirm a significant burden and many long-lasting disabilities to the society. Keywords: COVID-19, VILI, Paraseptal Emphysema, Pulmonary fibrosis, Pneumothorax

Development of a Transformation Method for Metschnikowia borealis and other CUG-Serine Yeasts

Yeasts belonging to the Metschnikowia genus are particularly interesting for the unusual formation of only two needle-shaped ascospores during their mating cycle. Presently, the meiotic process that can lead to only two spores from a diploid zygote is poorly understood. The expression of fluorescent nuclear proteins should allow the meiotic process to be visualized in vivo; however, no large-spored species of Metschnikowia has ever been transformed. Accordingly, we aimed to develop a transformation method for Metschnikowia borealis, a particularly large-spored species of Metschnikowia, with the goal of enabling the genetic manipulations required to study biological processes in detail. Genetic analyses confirmed that M. borealis, and many other Metschnikowia species, are CUG-Ser yeasts. Codon-optimized selectable markers lacking CUG codons were used to successfully transform M. borealis by electroporation and lithium acetate, and transformants appeared to be the result of random integration. Mating experiments confirmed that transformed-strains were capable of generating large asci and undergoing recombination. Finally, random integration was used to transform an additional 21 yeast strains, and all attempts successfully generated transformants. The results provide a simple method to transform many yeasts from an array of different clades and can be used to study or develop many species for various applications.