A series of new pyrazolo [4,3-f]quinolin-7-one derivatives were synthesized by multi-component reactions of equimolar amount of aromatic aldehydes with 2,2-dimethyl-1,3-dioxane-4,6-dione and 1H-indazol-5-amine in ethylene glycol without catalyst under microwave irradiation. This one-pot protocol has the advantage of good yields, simple workup procedure and shorter reaction time.

In the mol­ecule of the title compound, C26H22N4S2, the pyrazole ring is oriented at a dihedral angle of 0.85 (3)° with respect to the adjacent naphthyridine ring, while the other ring of naphthyridine adopts an envelope conformation. The dihedral angle between phenyl and pyrazole rings is 87.65 (3)°. In the crystal structure, weak inter­molecular C—H⋯N inter­actions link the mol­ecules into chains. The π–π contacts between the naphthyridine rings and the naphthyridine and thio­phene rings [centroid–centroid distances = 3.766 (3) and 3.878 (3) Å] may further stabilize the structure. A weak C—H⋯π inter­action is also present.

A practical, inexpensive, and rapid method for the stereoselective synthesis of pyrazolo [4,3-c]pyridine derivatives via microwave-assisted reactions of 3,5-diarylidenepiperidin-4-ones with phenylhydrazine in ethylene glycol. This method has the advantages of good yield, operational simplicity, and simple purification procedure.

A facile microwave‐assisted synthesis of pyrano[2,3‐d]pyrimidines derivatives is accomplished via reactions of 4‐arylmethylene‐2‐phenyloxazol‐5(4H)‐ones with pyrimidine‐4,6‐diol in ethylene glycol. The reaction is simple to perform and occurs under mild conditions with broad scope of applicability.

Background: Ankle sprains are one of the most common injuries in athletic populations. Misdiagnosed and untreated ankle sprains will cause chronic ankle instability (CAI), which can significantly affect the performance of athletes. This study aimed to investigate the prevalence and characteristics of CAI in elite athletes of different sports. Method: This cross-sectional study included 198 elite athletes from Guangdong provincial sports teams. All participants answered a questionnaire about ankle sprains and ankle instability. The severity of their ankle instability was evaluated by the Cumberland Ankle Instability Tool (CAIT). Participants further underwent clinical examinations from sports medicine doctors to determine the presence and characteristics of ankle instability. The datasets were analyzed to determine the differences in prevalence between age, gender, sports teams, and sports categories. Results: In 198 athletes, 39.4% (n = 78) had bilateral CAI while 25.3% (n = 50) had unilateral CAI. Female athletes had a higher prevalence of CAI than male athletes in the study (p = 0.01). Prevalence showed differences between sports categories, and were significantly higher in acrobatic athletes than non-contact athletes (p = 0.03). Conclusions: CAI was highly prevalent among elite athletes in this study, with female athletes and athletes in acrobatic sports being associated with a higher risk of developing CAI in their professional careers. Therefore, extra precautions need to be taken into account when applying ankle protections for these athletes.