The barrel section of the novel MIP Timing Detector (MTD) will be constructed as part of the upgrade of the CMS experiment to provide a time resolution for single charged tracks in the range of ...\(30-60\) ps using LYSO:Ce crystal arrays read out with Silicon Photomultipliers (SiPMs). A major challenge for the operation of such a detector is the extremely high radiation level, of about \(2\times10^{14}\) 1 MeV(Si) Eqv. n/cm\(^2\), that will be integrated over a decade of operation of the High Luminosity Large Hadron Collider (HL-LHC). Silicon Photomultipliers exposed to this level of radiation have shown a strong increase in dark count rate and radiation damage effects that also impact their gain and photon detection efficiency. For this reason during operations the whole detector is cooled down to about \(-35^{\circ}\)C. In this paper we illustrate an innovative and cost-effective solution to mitigate the impact of radiation damage on the timing performance of the detector, by integrating small thermo-electric coolers (TECs) on the back of the SiPM package. This additional feature, fully integrated as part of the SiPM array, enables a further decrease in operating temperature down to about \(-45^{\circ}\)C. This leads to a reduction by a factor of about two in the dark count rate without requiring additional power budget, since the power required by the TEC is almost entirely offset by a decrease in the power required for the SiPM operation due to leakage current. In addition, the operation of the TECs with reversed polarity during technical stops of the accelerator can raise the temperature of the SiPMs up to \(60^{\circ}\)C (about \(50^{\circ}\)C higher than the rest of the detector), thus accelerating the annealing of radiation damage effects and partly recovering the SiPM performance.
Incubation of human erythrocytes with inosine, pyruvate and phosphate increases several fold the ferrihemoglobin reductase activity, the values of which, however, depend on the age of blood (by 6 to ...2 times with respect to the normal value of fresh blood).
The main goal of this thesis is to provide a complete methodology to analyze finite multivariate mixture models. Our approach is fully nonparametric and it only requires the coordinates to be ...independent, conditional on the component membership. Since the number of components in the mixture is assumed to be known, we also developed a technique to select the number of components that best fits the model. In addition, we provide some tools to check if the assumption of conditional independence is reasonable. All the methods are evaluated by simulations, and compared with methodology existing in the literature. We also apply our methodology to two real datasets from cognitive psychology.
A case of supraclavicular metastatic follicular carcinoma which occurred 7 years after the patient had undergone total thyroidectomy is presented. By means of whole body 210-thallium scan, a precise ...diagnosis was made, while the whole body 131-I scan was negative. The thyroglobulin serum levels were high before surgery but significantly decreased after lymphadenectomy. The clinical use of this tracer to detect functioning and non-functioning metastases of thyroid carcinomas is discussed.
The synthesis of amides remains one of the most important transformations and it is one of the more frequently performed reactions. In the pharmaceutical industry, the formation of the amide group is ...pivotal and among the more important transformations in the design of the synthetic plan. This review presents an overview of only very recent contributions, published in the last three years, to highlight the latest progress in this “dateless” reaction, with a special focus on metal‐free methodologies. New, more efficient and/or greener stoichiometric methods, as well as catalytic strategies, have been discussed, either for the “classic” coupling approach between an amine and a carboxylic acid (or its activated equivalent) or for more innovative approaches, mainly involving oxidation procedures to generate amides starting from amines.
The amide function is unarguably of primary importance, being the constituent of natural and synthetic polymers and found in a wide variety of bioactive molecules. This review will discuss specifically the very recent advances in the area of amide synthesis, specially focusing on metal‐free strategies, based either on stoichiometric or on catalytic methods that were published in the last three years.
Recently, application of the flow technologies for the preparation of fine chemicals, such as natural products or Active Pharmaceutical Ingredients (APIs), has become very popular, especially in ...academia. Although pharma industry still relies on multipurpose batch or semibatch reactors, it is evident that interest is arising toward continuous flow manufacturing of organic molecules, including highly functionalized and chiral compounds. Continuous flow synthetic methodologies can also be easily combined to other enabling technologies, such as microwave irradiation, supported reagents or catalysts, photochemistry, inductive heating, electrochemistry, new solvent systems, 3D printing, or microreactor technology. This combination could allow the development of fully automated process with an increased efficiency and, in many cases, improved sustainability. It has been also demonstrated that a safer manufacturing of organic intermediates and APIs could be obtained under continuous flow conditions, where some synthetic steps that were not permitted for safety reasons can be performed with minimum risk. In this review we focused our attention only on very recent advances in the continuous flow multistep synthesis of organic molecules which found application as APIs, especially highlighting the contributions described in the literature from 2013 to 2015, including very recent examples not reported in any published review. Without claiming to be complete, we will give a general overview of different approaches, technologies, and synthetic strategies used so far, thus hoping to contribute to minimize the gap between academic research and pharmaceutical manufacturing. A general outlook about a quite young and relatively unexplored field of research, like stereoselective organocatalysis under flow conditions, will be also presented, and most significant examples will be described; our purpose is to illustrate all of the potentialities of continuous flow organocatalysis and offer a starting point to develop new methodologies for the synthesis of chiral drugs. Finally, some considerations on the perspectives and the possible, expected developments in the field are briefly discussed.
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