126 research outputs found

    Revisiting Qumran Cave 1Q and its archaeological assemblage

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    Qumran Cave 1Q was the first site of Dead Sea scroll discoveries. Found and partly emptied by local Bedouin, the cave was excavated officially in 1949 and published in the series Discoveries in the Judaean Desert (Volume 1) in 1955. Contents of the cave are found in collections worldwide, and in different institutions in Jerusalem and Amman. While the scrolls are the most highly prized artefacts from this cave, in archaeological terms they are part of an assemblage that needs to be understood holistically in order to make conclusions about its character and dating. This study presents all of the known items retrieved from the cave, including those that are currently lost, in order to consider what we might know about the cave prior to its emptying and the changes to its form. It constitutes preliminary work done as part of the Leverhulme funded International Network for the Study of Dispersed Qumran Caves Artefacts and Archival Sources [IN-2015-067].peer-reviewe

    An EPID Dosimetry Verification During Treatment

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    Purpose: This work reports the extension of a semiempirical method based on the correlation ratios to convert electronic portal imaging devices transit signals into in vivo doses for the step-and-shoot intensity-modulated radiotherapy Siemens beams. The dose reconstructed at the isocenter point Diso, compared to the planned dose, Diso,TPS, and a γ-analysis between 2-dimensional electronic portal imaging device images obtained day to day, seems to supply a practical method to verify the beam delivery reproducibility. Method: The electronic portal imaging device images were obtained by the superposition of many segment fields, and the algorithm for the Diso reconstruction for intensity-modulated radiotherapy step and shoot was formulated using a set of simulated intensity-modulated radiotherapy beams. Moreover, the in vivo dose-dedicated software was integrated with the record and verify system of the centers. Results: Three radiotherapy centers applied the in vivo dose procedure at 30 clinical intensity-modulated radiotherapy treatments, each one obtained with 5 or 7 beams, and planned for patients undergoing radiotherapy for prostatic tumors. Each treatment beam was checked 5 times, obtaining 900 tests of the ratios R = Diso/Diso,TPS. The average R value was equal to 1.002 ± 0.056 (2 standard deviation), while the mean R value for each patient was well within 5%, once the causes of errors were removed. The γ-analysis of the electronic portal imaging device images, with 3% 3 mm acceptance criteria, showed 90% of the tests with Pγ < 1 ≥ 95% and γmean ≤ 0.5. The off-tolerance tests were found due to incorrect setup or presence of morphological changes. This preliminary experience shows the great utility of obtaining the in vivo dose results in quasi real time and close to the linac, where the radiotherapy staff may immediately spot possible causes of errors. The in vivo dose procedure presented here is one of the objectives of a project, for the development of practical in vivo dose procedures, financially supported by the Istituto Nazionale di Fisica Nucleare

    Calibration of Elekta aSi EPIDs used as transit dosimeter.

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    The transit in vivo dosimetry performed by the Electronic Portal Imaging Device (EPID), avoids the problem of solid-state detector positioning on the patient. Moreover, the dosimetric characterization of the recent Elekta aSi EPIDs in terms of signal stability and linearity enables these detectors adaptable for the transit in vivo dosimetry with 6, 10 and 15 MV photon beams. However, the implementation of the EPID transit dosimetry requires several measurements. Recently, the present authors have developed an in vivo dosimetry method for the 3D CRT based on correlation functions defined by the ratios between the transit signal, st (w,L), by the EPID and the phantom mid-plane dose, Dm(w,L), at the Source to Axis Distance (SAD) as a function of the phantom thickness, w, and the square field dimensions, L. When the phantom mid-plane was positioned at distance d from the SAD, the ratios st(w,L)/s't(d,w,L), were used to take into account the variation of the scattered photon contributions on the EPID as a function of, d and L. The aim of this paper was the implementation of a procedure that uses generalized correlation functions obtained by nine Elekta Precise linac beams. The procedure can be used by other Elekta Precise linacs equipped with the same aSi EPIDs assuring the stabilities of the beam output factors and the EPID signals. The calibration procedure of the aSi EPID here reported avoids measurements in solid water equivalent phantoms needed to implement the in vivo dosimetry method in the radiotherapy center. A tolerance level ranging between ±5% and ±6% (depending on the type of tumor) was estimated for the comparison between the reconstructed isocenter dose, Diso and the computed dose Diso, TPS by the treatment planning system (TPS)

    Campagna di scavi ISCAB-FTL e USI alla grotta 11Q di Qumran, marzo 2017

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    The paper presents the report about the excavation campaign at Qumran cave 11Q, carried out from 9th to 19th March 2017 by the Istituto di cultura e archeologia delle terre bibliche of the Facoltà di Teologia di Lugano (ISCAB-FTL) and by the Università della Svizzera Italiana (USI). Previous archaeological excavations, undertaken by Roland de Vaux (1956) and Joseph Patrick (1988 and 1991), were published in brief preliminary reports only. The 2017 archaeological campaign, complemented by speleological and geological investigation, enriched the dossier for the forthcoming final report. Among the main results are: the discovery of an upper chamber; the opening of a sounding in an area barely interested by previous excavations; the analysis of the entrance area and the natural factors which may concur to the closure of the cave; the documentation of 11Q morphology employing modern technology (3D scan)

    A combined protocol with piroxicam, chemotherapy and whole pelvic irradiation with simultaneous boost volumetric modulated arc radiotherapy for muscle-invasive canine urinary transitional cell carcinoma: first clinical experiences

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    The aims of this pilot study were to evaluate the feasibility and efficacy of high-dose hypo-fractionated volumetric modulated arc radiotherapy (VMAT) applied to the whole pelvic region radiotherapy (WPRT) with multilevel simultaneous integrated boost (MLSIB) combined with piroxicam and chemotherapy in canine transitional cell carcinoma (TCC) of the lower urinary tract with muscle invasion transitional cell carcinoma (TCC). Twelve dogs were enrolled, according to stage, in two groups: group 1, TCC confined to the urinary tract; group 2, TCC with metastasis. The planning target volume (PTV-tumor) dose was tailored from 36 to 42 Gy in 6 fractions. All dogs were prescribed piroxicam and radiosensitizing carboplatin and six received chemotherapy after radiotherapy. Serial follow-up with computed tomography (CT) and magnetic resonance imaging (MRI) examinations was performed. Disease control and toxicity effects were evaluated according to the Response Evaluation Criteria in Solid Tumor (RECIST) and Veterinary Radiation Therapy Oncology Group (VRTOG) criteria. The treatment was well tolerated, and no high-grade side effects were reported. The median overall survival times for group 1 and group 2 were 1,230 days and 150 days, respectively. A considerable percentage of patients in group 1 (50%) was still alive at the time of writing, and a longer follow-up could enable a more accurate survival analysis. This preliminary analysis showed that VMAT applied to the WPRT with MLSIB is an effective and safe option for dogs suffering from lower urinary TCC although the presence of metastases worsens the prognosis

    Case report: Sacral agenesis in two boxer dogs: clinical presentation, diagnostic investigations, and outcome.

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    Two boxer dogs from the same litter were presented at 3 months of age for urinary and fecal incontinence. Both dogs had an abnormal tail consisting of a small stump, an atonic anal sphincter, and absent perineal reflex and sensation. Neurological evaluation was indicative of a lesion of the cauda equina or sacral spinal cord. Radiology and CT scan of the spine displayed similar findings in the two dogs that were indicative of sacral agenesis. Indeed, they had 6 lumbar vertebrae followed by a lumbosacral transitional vertebra, lacking a complete spinous process, and a hypoplastic vertebra carrying 2 hypoplastic sacral transverse processes as the only remnant of the sacral bone. Caudal vertebrae were absent in one of the dogs. On MRI, one dog had a dural sac occupying the entire spinal canal and ending in a subfascial fat structure. In the other dog, the dural sac finished in an extracanalar, subfascial, well-defined cystic structure, communicating with the subarachnoid space, and consistent with a meningocele. Sacral agenesis-that is the partial or complete absence of the sacral bones-is a neural tube defect occasionally reported in humans with spina bifida occulta. Sacral agenesis has been described in human and veterinary medicine in association with conditions such as caudal regression syndrome, perosomus elumbis, and Currarino syndrome. These neural tube defects are caused by genetic and/or environmental factors. Despite thorough genetic investigation, no candidate variants in genes with known functional impact on bone development or sacral development could be found in the affected dogs. To the best of the authors' knowledge, this is the first report describing similar sacral agenesis in two related boxer dogs

    High gain observed in X-ray induced currents in synthetic single crystal diamonds

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    Diamond is considered as tissue equivalent, due to its low atomic number, which makes it a particular attractive material for medical radiation dosimetry applications. X-ray dosimeters made of natural single crystal diamonds are commercially available and routinely used, with typical gain values of about 0.5. The selection of suitable natural diamonds for this purpose is time and cost intensive. We report an X-ray induced current study in synthetic single crystal diamonds. Similar to natural diamond dosimeters, the devices had to be pre-irradiated before use to achieve a reproducible performance. We compare two chemical vapour deposited (CVD) samples grown by Element Six Ltd (UK). D1 was a high purity sample contacted in a sandwich structure with an asymmetric contact pair. Sample D2 was cut vertically and contained some nitrogen rich layers. It was contacted with two Ohmic contacts, which partly covered the high temperature/high pressure substrate material. Particle spectroscopy suggests better charge transport in D1 compared to D2, most likely caused by the lower purity. In contrast to this, large gain values up to 6 x 104 and a sensitivity of similar to 30 mC/Gy were measured at field strengths of 2 kV/cm in D2, and only 7 mu C/Gy in D1, despite their comparable volumes. We deduce that the gain observed in these devices is affected by the electrical properties of the metal-diamond contacts. The response time of the high gain device was in the order of minutes, which is longer than expected by a purely photoconductive process. Long persistent currents have been reported before in diamond under UV irradiation and modifications of gain and response time by surface treatment of UV detectors are known in the literature, highlighting the influence of the surface and contact interface on the device operation. Our results indicate that synthetic single crystal diamond provides a promising material for high sensitivity tissue-equivalent X-ray dosimeters. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

    Dosimetric characterization of a large area pixel-segmented ionization chamber.

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    A pixel-segmented ionization chamber has been designed and built by Torino University and INFN. The detector features a 24 x 24 cm2 active area divided in 1024 independent cylindrical ionization chambers and can be read out in 500 micros without introducing dead time; the digital charge quantum can be adjusted between 100 fC and 800 fC. The sensitive volume of each single ionization chamber is 0.07 cm3. The purpose of the detector is to ease the two-dimensional (2D) verifications of fields with complex shapes and large gradients. The detector was characterized in a PMMA phantom using 60Co and 6 MV x-ray photon beams. It has shown good signal linearity with respect to dose and dose rate to water. The average sensitivity of a single ionization chamber was 2.1 nC/Gy, constant within 0.5% over one month of daily measurements. Charge collection efficiency was 0.985 at the operating polarization voltage of 400 V and 3.5 Gy/min dose rate. Tissue maximum ratio and output factor have been compared with a Farmer ionization chamber and were found in good agreement. The dose profiles have been compared with the ones obtained with an ionization chamber in water phantom for the field sizes supplied by a 3D-Line dynamic multileaf collimator. These results show that this detector can be used for 2D dosimetry of x-ray photon beams, supplying a good spatial resolution and sensibly reducing the time spent in dosimetric verification of complex radiation fields

    Advancing the scientific study of prehospital mass casualty response through a Translational Science process: the T1 scoping literature review stage

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    PurposeThe European Union Horizon 2020 research and innovation funding program awarded the NIGHTINGALE grant to develop a toolkit to support first responders engaged in prehospital (PH) mass casualty incident (MCI) response. To reach the projects' objectives, the NIGHTINGALE consortium used a Translational Science (TS) process. The present work is the first TS stage (T1) aimed to extract data relevant for the subsequent modified Delphi study (T2) statements.MethodsThe authors were divided into three work groups (WGs) MCI Triage, PH Life Support and Damage Control (PHLSDC), and PH Processes (PHP). Each WG conducted simultaneous literature searches following the PRISMA extension for scoping reviews. Relevant data were extracted from the included articles and indexed using pre-identified PH MCI response themes and subthemes.ResultsThe initial search yielded 925 total references to be considered for title and abstract review (MCI Triage 311, PHLSDC 329, PHP 285), then 483 articles for full reference review (MCI Triage 111, PHLSDC 216, PHP 156), and finally 152 articles for the database extraction process (MCI Triage 27, PHLSDC 37, PHP 88). Most frequent subthemes and novel concepts have been identified as a basis for the elaboration of draft statements for the T2 modified Delphi study.ConclusionThe three simultaneous scoping reviews allowed the extraction of relevant PH MCI subthemes and novel concepts that will enable the NIGHTINGALE consortium to create scientifically anchored statements in the T2 modified Delphi study
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