We carried out optical spectroscopic observations of the most enigmatic dwarf nova WZ Sge in 11 nights during the 2001 superoutburst. Our observations covered the period from the initial phase several hours before the maximum to the ninth maximum of the rebrightening phase. The first spectrum shows absorption lines of H i (except for Hα), He i, and Na i, as well as emission lines of Heii , C ii...

During our medical training, we learned that oxygen administration in patients with chronic obstructive pulmonary disease (COPD) induces hypercapnia through the 'hypoxic drive' mechanism and can be dangerous. This mindset frequently results in the reluctance of clinicians to administer oxygen to hypoxemic patients with COPD. However, this fear is not based on evidence in the literature. Here, w...