71 research outputs found

    Ellis-Van Creveld syndrome

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    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 N=32N=32 and N=34N=34 shell gap for Ti and V by the first high-precision MRTOF mass measurements at BigRIPS-SLOWRI

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    The atomic masses of 55^{55}Sc, 56,58^{56,58}Ti, and 5659^{56-59}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 56,58^{56,58}Ti and 5659^{56-59}V the mass uncertainties have been reduced down to the order of 10keV10\,\mathrm{keV}, shedding new light on the N=34N=34 shell effect in Ti and V isotopes by the first high-precision mass measurements of the critical species 58^{58}Ti and 59^{59}V. With the new precision achieved, we reveal the non-existence of the N=34N=34 empirical two-neutron shell gaps for Ti and V, and the enhanced energy gap above the occupied νp3/2\nu p_{3/2} orbit is identified as a feature unique to Ca. We perform new Monte Carlo shell model calculations including the νd5/2\nu d_{5/2} and νg9/2\nu g_{9/2} orbits and compare the results with conventional shell model calculations, which exclude the νg9/2\nu g_{9/2} and the νd5/2\nu d_{5/2} 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 N=34N=34
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