SNS Experience with a High-Energy Superconducting Proton Linac

The Spallation Neutron Source (SNS) requires a high power (> 1 MW) 1 GeV proton beam to produce an intense source of neutrons. The proton beam acceleration is primarily provided by a Superconducting Cavity Linac (SCL). This SCL is the first use of superconducting cavities to accelerate protons to energies this high and is also the first application of pulsed SRF with proton beams. The SCL has been in operation for over two years now. The experience in commissioning and operating the linac are discussed in this paper

Medication-related osteonecrosis of the jaw in a cancer patient receiving lenvatinib

Medication-related osteonecrosis of the jaw (MRONJ) is an adverse drug reaction that affects the mandible and maxilla of patients exposed to bone-targeting agents such as anti-resorptive and anti-angiogenic agents. Several MRONJ cases have been reported after dental extractions in patients under treatment with anti-angiogenic agents, including receptor activator of nuclear factor κB ligand (RANKL) inhibitor, anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibody, mammalian target of rapamycin (mTOR) inhibitors, and tyrosine kinase inhibitors (TKIs). The aim of this article was to describe an original case of lenvatinib-related osteonecrosis of the jaw in a patient affected by thyroid cancer. A 58-year-old man diagnosed with Hurthle cell thyroid cancer, who was undergoing treatment with lenvatinib, developed maxillary osteonecrosis after a dental extraction. No other concomitant local or systemic risk factors for MRONJ were present. With new cancer therapies applied every year, it is important to note this novel case of lenvatinib osteonecrosis of the jaw in a patient undergoing cancer treatment

Spontaneous bisphosphonate-related osteonecrosis of the left hemi-mandible: Similarities with phossy jaw.

Intravenous bisphosphonates (BP) play a key role in the treatment of bone metastases. As a long-term side effects BP, a form of avascular osteonecrosis of the jaw has been reported. Although, invasive oral local procedures are often present in clinical history of patients suffering from bisphosphonates-related osteonecrosis of the jaws (BRONJ), about up to 50% of BRONJ are spontaneous. We report a case of a 68-year-old female with a spontaneous wide bone sequestration of the left mandibular body onset after infusion of zoledronic acid for 18 cycles for osseous metastasis due to metastatic anaplastic thyroidal carcinoma. Surprisingly the clinical aspects of the patient initially reminded us of the famous pathology described in 1899 called phossy jaw. This case is remarkable not only for the spontaneity of the osteonecrosis, but, above all, for the clinical similarity with cases of phossy jaw, described for the first time in the literature, thereby suggesting a potential common pathogenesis

Evaluation of posttreatment response of hepatocellular carcinoma: comparison of ultrasonography with second-generation ultrasound contrast agent and multidetector CT

We evaluated the ability of one-month follow-up contrast- enhanced ultrasound (CEUS) with second-generation contrast agent in monitoring radio frequency ablation (RFA) and transcatheter arterial chemoembolization (TACE) treatments of hepatocellular carcinoma (HCC). One-hundred forty-eight HCCs were studied using CEUS: 110 nodules were treated with RFA [41/110 RFA were performed using a pretreatment and an immediate postablation evaluation using CEUS (group 1); 69/110 using only US guidance (group 2)] and 38 nodules treated with TACE. For statistical analysis, McNemar test was used. Overall complete response was observed in 107/148 nodules (92/110 treated with RFA and 15/38 with TACE). A better rate of complete response was found in group 1 compared to group 2 (92.7% vs. 78.3%). In RFA treatment, CEUS showed a sensitivity of 83.3% and a specificity of 100% (diagnostic accuracy of 97%) using MDCT as reference standard with no statistical difference (p > 0.05). CEUS detected all cases of incomplete response in HCC treated with TACE using angiography as reference standard (diagnostic accuracy 100%).We recommend assessing residual intratumoral flow on CEUS during RFA procedure to determine the necessity of immediate additional treatment. In case of positive CEUS results, HCC treated with TACE should be considered still viable

On a new definition of quantum entropy

It is proved here that, as a consequence of the unitary quantum evolution, the expectation value of a properly defined quantum entropy operator (as opposed to the non-evolving von Neumann entropy) can only increase during non adiabatic transformations and remains constant during adiabatic ones. Thus Clausius formulation of the second law is established as a theorem in quantum mechanics, in a way that is equivalent to the previously established formulation in terms of minimal work principle [A. E. Allahverdyan and T. M. Nieuwenhuizen, Phys. Rev. E 71, 046107 (2005)]. The corresponding Quantum Mechanical Principle of Entropy Increase is then illustrated with an exactly solvable example, namely the driven harmonic oscillator. Attention is paid to both microcanonical and canonical initial condition. The results are compared to their classical counterparts.Comment: 4 pages, 3 figure

Study of the role of the interface between niobium films and copper RF resonators

Niobium-coated copper resonators are usually produced with an oxide interface between the film and the substrate. This oxide has two sources: the passivation layer inevitably formed on the surface of the cavity after chemical preparation before coating, and the niobium oxide which builds up on the surface of the cathode when it is exposed to air, and is transferred to the cavity surface during coa ting. The oxide layer may influence both the purity and the structural properties of the film, and in turn its RF behaviour. To study its effect, some cavities have been coated with a special two-cath ode sputtering system, allowing for a complete removal of both oxide layers by sputter-etching. For comparison, a few cavities have also been produced with the same coating system without sputter-etch ing, or with a controlled oxidation of the copper surface of the cavity after sputter-etching. Two cavities have also been produced without oxide interface using Kr and Ne as sputter gas instead of Ar

Water extract of Cryphaea heteromalla (Hedw.) D. Mohr bryophyte as a natural powerful source of biologically active compounds

Bryophytes comprise of the mosses, liverworts, and hornworts. Cryphaea heteromalla, (Hedw.) D. Mohr, is a non-vascular lower plant belonging to mosses group. To the date, the most chemically characterized species belong to the liverworts, while only 3.2% and 8.8% of the species belonging to the mosses and hornworts, respectively, have been investigated. In this work, we present Folin–Ciocalteu and oxygen radical absorbance capacity (ORAC) data related to crude extracts of C. heteromalla obtained by three different extraction solvents: pure water (WT), methanol:water (80:20 v/v) (MET), and ethanol:water (80:20 v/v) (ETH). The water extract proved to be the best solvent showing the highest content of biophenols and the highest ORAC value. The C. heteromalla-WT extract was investigated by HPLC-TOF/MS (High Performance Liquid Chromatography-Time of Flight/Mass Spectrometry) allowing for the detection of 14 compounds, five of which were phenolic compounds, derivatives of benzoic, caffeic, and coumaric acids. Moreover, the C. heteromalla WT extract showed a protective effect against reactive oxygen species (ROS) generation induced by tert-butyl hydroperoxide (TBH) on the murine NIH-3T3 fibroblast cell line

Study of the surface resistance of niobium sputter-coated copper cavities

A systematic study of the superconducting properties of niobium films deposited on the inner wall of copper radiofrequency cavities is presented. Films are grown by sputtering with different discharge gases (Xe, Kr, Ar and Ar/Ne mixtures) on substrates prepared under different conditions. The measured quantities include the surface resistance at 1.5 GHz, the critical temperature and the penetration depth. The surface resistance is analyzed in terms of its dependence on temperature, RF field and the density of trapped fluxons. Once allowance for electron scattering is made by means of a single mean free path parameter, good agreement with BCS theory is observed. The residual resistance is observed to be essentially noncorrelated with the superconducting properties, although influenced by specific coating conditions. On occasions, very low residual resistances, in the nano-ohm range, have been maintained over a broad range of RF field, indicating the absence of fundamental limitations specific to the film technology in practical applications. (7 refs)

Study of the surface resistance of superconducting niobium films at 1.5 GHz

A systematic study of superconducting properties of niobium films sputtered on the inner wall of radiofrequency cavities is presented. The measured quantities include in particular the response to 1.5 GHz microwaves, the critical temperature, the penetration depth and the magnetic penetration field. In addition to films grown in different gas discharges (Xe, Kr, Ar and Ar/Ne mixtures) and to films grown on substrates prepared under different conditions, the study also includes bulk niobium cavities. The surface resistance is analysed in terms of its dependence on temperature, on RF field and, when relevant, on the density of trapped fluxons. A simple parameterisation is found to give a good fit to the data. Once allowance for the presence of impurities and defects is made by means of a single parameter, the electron mean free path, good agreement with BCS theory is observed. The fluxon-induced losses are studied in detail and their dependence on RF field, on temperature and on the density of trapped fluxons is analysed. The residual resistance is observed to be essentially uncorrelated with the other variables, suggesting that it is dominantly extragranular. In occasions very low residual resistances, in the n Omega range, have been maintained over a broad range of RF field, indicating the absence of significant fundamental limitations specific to the film technology in practical applications such as the production of accelerating cavities for particle accelerators. (130 refs)

Niobium sputter-coated copper resonators

Niobium sputter-coated copper resonators are successfully employed in operating particle accelerators, the most outstanding example being LEP2 at CERN. In this review we present recent progress in the understanding of the basic principles governing their behaviour, based on an extensive R&D programme carried out at CERN on 1.5 GHz resonators operated in the TM010 mode. At the present stage of the s tudy, no fundamental limitation has been found which would prevent the use of this technology for future high-field, high-Q accelerating cavities