The amniotic membrane is the innermost layer of the placenta. It consists of stem cells with reduced immunogenicity that secrete cytokines and growth factors, which have anti-inflammatory and ...antifibrotic effects and promote epithelialization. Membranes are obtained from women who are undergoing elective cesarean delivery. These allografts are typically used in ophthalmology for ocular surface reconstruction but have the potential for other applications, such as wound healing.
The treatment of fractures, refractures, and bone nonunions with avascular segments of osteoporotic bones still represents a problem in surgical practice. The major concerns are the biological ...potential and biomechanical instability of the bone. Therefore, new osteosynthetic techniques and implants are constantly being developed.
High-intensity intermittent performance in soccer is widely assessed using the yo-yo intermittent recovery level 2 test (YYIR2). This test is usually associated with aerobic-anaerobic performance. ...However, less is known about the direct or indirect contributions of abilities, including the anaerobic component. This study aims to propose a three-level model of factors contributing to YYIR2 performance, based on the investigation of relationships with aerobic endurance, repeated-sprint ability (RSA), and the linear and change-of-direction speed and power variables. Eighteen soccer players performed the YYIR2, with a 20-m shuttle run test (20mSR), an RSA test with change-of-direction, 5-m and 20-m sprints, and a 505 test, countermovement jump, squat jump, and drop jump. The results showed a significant relationship between the YYIR2 distance and the 20mSR distance (
= 0.721,
= 0.001), as well as with the RSA test mean time (
= -0.594,
= 0.009). In the second level, the 20mSR distance performance was not associated with any of the speed and power variables. However, the RSA test mean time correlated with the 5-m sprint (
= 0.587,
= 0.010), 20-m sprint (
= 0.702,
= 0.001), and 505 test (
= 0.585
= 0.011) performance. In the third level, the 20-m sprint time was related to the squat jump (
= -0.577
= 0.012) and countermovement jump (
= -0.768
< 0.001) heights. In addition to aerobic endurance, this study highlights the importance of the anaerobic component in YYIR2 performance. More specifically, aerobic endurance (52%) and RSA (36%) are the main determinants of YYIR2 performance. Subsequently, the RSA performance is determined by the linear (34-49%) and change-of-direction speed (35%), while the explosive power of lower limbs contributes to sprinting performance (33-59%). Coaches should focus on the development of these abilities to improve the high-intensity intermittent performance of soccer players.
