[Ultrasonographic and clinical features of common testicular germ cell tumors in children].

Objective: To study the ultrasonographic manifestations and clinical features of common pediatric testicular germ cell tumors (TGCT) in children.

Methods: We retrospectively analyzed the laboratory, ultrasonographic and clinical data on 92 children with TGCT diagnosed in Shanghai Children's Hospital from March 2013 to January 2019, and investigated the values of the serum alpha-fetoprotein (AFP) level and maximum diameter of tumors in the diagnosis of benign and malignant tumors using the ROC curve.

Results: Of the 92 cases of pediatric TGCT, 64 (69.

[High-frequency ultrasonography for diagnosis and differential diagnosis of acute scrotum in children].

Objective: To analyze the high-frequency ultrasound image features of acute scrotum in children and explore the value of high-frequency ultrasonography in the diagnosis and differential diagnosis of the disease.

Methods: This retrospective study included 256 children aged 2 days to 14 years undergoing color Doppler ultrasonography at 2 hours to 3 days after onset of acute scrotum. We analyzed the morphology, internal echo and blood supply of the testis in comparison with the clinical and pathological results.

Fracture behaviors of pre-cracked monolayer molybdenum disulfide: A molecular dynamics study.

The fracture strength and crack propagation of monolayer molybdenum disulfide (MoS) sheets with various pre-existing cracks are investigated using molecular dynamics simulation (MDS). The uniaxial tensions of pre-cracked monolayer MoS sheets with different crack tips, different locations of crack, different crack lengths and angled cracks are simulated and studied. The results show that the configuration of crack tip can influence significantly the fracture behaviors of monolayer MoS sheets while the location of crack does not influence the fracture strength.