Research

The FRAGILE‐HF study was a prospective multicentre cohort study enrolling consecutive hospitalized patients with heart failure aged ≥65 years. The study objectives were to examine the prevalence, overlap, and prognostic implications of the coexistence of multiple frailty domains. Physical frailty, social frailty, and cognitive dysfunction were evaluated by the Fried phenotype model, Makizako's 5 items, and Mini‐Cog, respectively. The primary study outcome was the combined endpoint of heart failure rehospitalization and all‐cause death within 1 year.

Spermatogenesis is one of the most complex and longest processes of sequential cell proliferation and differentiation in the body, taking more than a month from spermatogonial stem cells, through meiosis, to sperm formation1,2. The whole process, therefore, has never been reproduced in vitro in mammals3,4,5, nor in any other species with a very few exceptions in some particular types of fish6,7. Here we show that neonatal mouse testes which contain only gonocytes or primitive spermatogonia as germ cells can produce spermatids and sperm in vitro with serum-free culture media.