Accretionary carbonate spherules of small size are a common component of distal Chicxulub impact ejecta deposits and are documented at Brazos River, Texas, and Bass River, New Jersey, located about 1000 km and 2500 km respectively from the crater. This spherule type is also present in northeast Mexico and is related to accretionary carbonate lapilli present in proximal Chicxulub ejecta deposits...

triphalangeal thumb is characterized by the interposition of an extra-phalanx between two normal ones. in this article the authors present the case of a 24-year-old man with bilateral triphalangeal thumb of opposable type, without any other associated anomaly or genetic syndrome. the patient had triangular delta extra-phalanxes that caused ulnar deviation of both thumbs. surgical procedure for ...

background: physical wedges are still widely used as beam modifiers in external beam radiotherapy. however the presence of them in the beam trace may cause beam hardening which may not be considered in many treatment planning systems. the aim of this study is to investigate the beam hardening effect generated by physical wedges via different beam quality indexes as photon spectrum, half value l...

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Venus displays thousands of old circular structures, with topographic rims 5-2000 km in diameter, that have the morphology and cookie-cutter superposition required of impact craters and basins. Many structures have interior central or ring uplifts or broad, low volcanic constructs. Many are multiring. Old uplands are saturated with the structures, which there are variably eroded, whereas lowlan...

BACKGROUND Theoretical considerations suggest that leg length increases after opening wedge high tibial osteotomy (HTO) and decreases after closing wedge HTO; however, in vivo studies have yielded conflicting results. This meta-analysis therefore assessed changes in leg length after opening wedge and closing wedge HTO. METHODS All studies comparing pre- and postoperative leg length in patient...

background: one of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment. objective: in the present study the impact of wedge and block on neutron contamination production is investigated. the evaluations are conducted for a 15 mv siemens primus linear accelerator.  methods: simulations were performed using mcnpx mon...

Background: The presence of a wedge filter in the beam trajectory can modify the beam quality and cause some changes in the dosimetry parameters which are usually difficult to be measured directly and accurately. Material and Methods: In this study the MCNP-4C Monte Carlo code was used to simulate the 9 MV photon beam generated by a linear accelerator. Upon getting a good agreement bet...