71 research outputs found
Ellis-Van Creveld syndrome
Ellis-van Creveld syndrome (EVC) is a chondral and ectodermal dysplasia characterized by short ribs, polydactyly, growth retardation, and ectodermal and heart defects. It is a rare disease with approximately 150 cases reported worldwide. The exact prevalence is unknown, but the syndrome seems more common among the Amish community. Prenatal abnormalities (that may be detected by ultrasound examination) include narrow thorax, shortening of long bones, hexadactyly and cardiac defects. After birth, cardinal features are short stature, short ribs, polydactyly, and dysplastic fingernails and teeth. Heart defects, especially abnormalities of atrial septation, occur in about 60% of cases. Cognitive and motor development is normal. This rare condition is inherited as an autosomal recessive trait with variable expression. Mutations of the EVC1 and EVC2 genes, located in a head to head configuration on chromosome 4p16, have been identified as causative. EVC belongs to the short rib-polydactyly group (SRP) and these SRPs, especially type III (Verma-Naumoff syndrome), are discussed in the prenatal differential diagnosis. Postnatally, the essential differential diagnoses include Jeune dystrophy, McKusick-Kaufman syndrome and Weyers syndrome. The management of EVC is multidisciplinary. Management during the neonatal period is mostly symptomatic, involving treatment of the respiratory distress due to narrow chest and heart failure. Orthopedic follow-up is required to manage the bones deformities. Professional dental care should be considered for management of the oral manifestations. Prognosis is linked to the respiratory difficulties in the first months of life due to thoracic narrowness and possible heart defects. Prognosis of the final body height is difficult to predict
A new study of the and shell gap for Ti and V by the first high-precision MRTOF mass measurements at BigRIPS-SLOWRI
The atomic masses of Sc, Ti, and V have been
determined using the high-precision multi-reflection time-of-flight technique.
The radioisotopes have been produced at RIKEN's RIBF facility and delivered to
the novel designed gas cell and multi-reflection system (ZD MRTOF), which has
been recently commissioned downstream of the ZeroDegree spectrometer following
the BigRIPS separator. For Ti and V the mass uncertainties
have been reduced down to the order of , shedding new light
on the shell effect in Ti and V isotopes by the first high-precision
mass measurements of the critical species Ti and V. With the new
precision achieved, we reveal the non-existence of the empirical
two-neutron shell gaps for Ti and V, and the enhanced energy gap above the
occupied orbit is identified as a feature unique to Ca. We
perform new Monte Carlo shell model calculations including the
and orbits and compare the results with conventional shell model
calculations, which exclude the and the orbits. The
comparison indicates that the shell gap reduction in Ti is related to a partial
occupation of the higher orbitals for the outer two valence neutrons at
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