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In a medical accelerator, real-time monitoring systems of the beam and dose delivered to the patient are mandatory. In this work, we present a compact current profile detector that has been designed and tested in the framework of the TOP-IMPLART (Intensity Modulated Proton Linear Accelerator for RadioTerapy) project. This project foresees the realization of a proton linear accelerator, currently under construction at ENEA Frascati, for proton therapy applications. The linac produces a pulsed proton beam with 3 µs duration at 50 Hz repetition rate with a pulse current between 0.5 and 50 μA. A large dynamic range and spatial constraints make the use of usual noninterceptive beam diagnostics unfeasible. Therefore, the use of a beam current monitor based on a passive RF cavity working in the TM010 mode has been proposed. This paper reports the electromagnetic design of the device guided by a simplified analytical model. A prototype of such a device has been realized, characterized, and tested on the linac with a 35 MeV beam varying the beam current. The test results in air and in vacuum, together with the signal detection systems used, are presented. [ABSTRACT FROM AUTHOR]

In the framework of the Italian TOP-IMPLART project (Regione Lazio), ENEA-Frascati, ISS and IFO are developing and constructing the first proton linear accelerator based on an actively scanned beam for tumor radiotherapy with final energy of 150 MeV. An important feature of this accelerator is modularity: an exploitable beam can be delivered at any stage of its construction, which allows for immediate characterization and virtually continuous improvement of its performance. Currently, a sequence of 3 GHz accelerating modules combined with a commercial injector operating at 425 MHz delivers protons up to 35 MeV. Several dosimetry systems were used to obtain preliminary characteristics of the 35-MeV beam in terms of stability and homogeneity. Short-term stability and homogeneity better than 3% and 2.6%, respectively, were demonstrated; for stability an improvement with respect to the respective value obtained for the previous 27 MeV beam. [ABSTRACT FROM AUTHOR]

These experiments were designed to test the ability of certain analogs and metabolites of all-transretinoic acid (RA), 13-cis-retinoic acid, 4-hydroxy-alltrans-retinoic acid, 4-keto-all-trans-retinoic acid, trimethylmethoxyphenol (TMMP) analog of retinoic acid, and TMMP analog of ethyl retinoate (etretinate) to compete for cellular retinoic acid-binding protein (CRABP) in skin and testes of rats. All retinoids, except etretinate, bind to CRABP in a competitive manner with a similar affinity (approximately 5×10 M for skin and 3×10 M for testes). In contrast, etretinate binds in a noncompetitive manner with a much lower affinity (7.7×10 M for skin and 7.5×10 M for testes). The values (μ M) of IC for CRABP from rat skin are 0.43, 0.41, 0.95, 0.83, and 77.4 and those from rat testes are 0.59, 1.29, 2.25, 2.30, and 75.25 for all-trans-RA, 13-cis-RA, 4-hydroxy-all-trans RA, 4-keto-all-trans-RA, TMMP analog of RA, and etretinate, respectively. Etretinate is a potent retinoid that is used in the treatment of psoriasis. The lack of quantitative correlation between IC and the biological activity of etretinate may be explained in that the active form of etretinate in the body may be the carboxylic acid form (TMMP analog of RA) which binds to CRABP with higher affinity. [ABSTRACT FROM AUTHOR]

1. The feasibility and accuracy of the cloacal sexing technique in greater rhea chicks was assessed using chicks of two captive populations of greater rhea in Córdoba, Argentina. 2. A total of 46 greater rhea chicks of 2 to 3 months of age were randomly arranged into three groups and the members of each group were sexed by a different operator. 3. A feather of each chick was plucked for sexing through a molecular method and results were used as controls. 4. Sex was correctly assigned by cloacal inspection in 98% of the cases. Chick manipulation was easily performed and no infections or traumatic lesions were observed a posteriori. 5. Cloacal sexing of rhea chicks up to 3 months of age does not affect animal welfare and should be considered an efficient alternative to molecular methods. [ABSTRACT FROM PUBLISHER]