Exchange maintenance methods of Hitachi electron microscope H-600 faults, master the workflow of vacuum system, and improve maintenance level together. Analyzed some cases of troubleshooting to Hitachi electron microscope H-600, collected troubleshooting skills, and gives related solutions.

OBJECTIVE: To explore the phenotype and pathogenesis of a fetus with a rare chromosomal abnormality. METHODS: The fetus was analyzed by clinical prenatal ultrasonography, G-banding karyotyping and next generation sequencing (NGS). RESULTS: Prenatal ultrasonography of the fetus showed Dandy-Walker syndrome, growth restriction, and right-heart system dysplasia. The fetus had a chromosomal karyotype of 47,XY,t(11;22)(q23.3;q11.2),+der(22)t(11;22). Duplication of 11q23.3q25 and 22q11.1q21 were also detected by NGS. The chromosomal translocation carried by the fetus was derived from his father. CONCLUSION Duplications of chromosome 11q23.3q25 and 22q11.1q11.21 segments probably underlie the Dandy-Walker syndrome, growth restriction, and hypoplasia of the right heart system in the fetus.
Chromosome Disorders ; Chromosomes, Human ; Female ; Fetus ; Humans ; Karyotyping ; Pregnancy ; Prenatal Diagnosis ; Translocation, Genetic ; Trisomy