Antioxidant capacity and heat damage of powder products from South American plants with functional properties

Aim of the study was to evaluate color, total polyphenol content (TPC), antioxidant capacity (ABTS, FRAP, DPPH), reducing sugars and heat damage (furosine, hydroxymethylfurfural, glucosylisomaltol) of 21 commercial powder products obtained from South-American fruits (mesquite, lucuma, camu camu), seeds (amaranth, purple maize), roots and tubers (yacon, maca, mashua, tocosh), bark (cat\u2019s claw) and leaves (graviola). TPC and antioxidant capacity were maximum in camu camu and cat\u2019s claw powders, and minimum in tocosh, amaranth, lucuma and maca; graviola, mashua, purple maize and mesquite also showed good antioxidant attributes. Yacon, mashua and lucuma powders had high reducing sugars content (40.9, 34.4 and 21.2 g/100 g DM, respectively) and heat damage (HMF 146.6 mg/kg, furosine 2399.8 and 2228.4 mg/100 g protein, respectively). Overall, camu camu powder and cat\u2019s claw were the most interesting products, having high levels of total polyphenols and antioxidant capacity together with very low heat damage

BIOLOGICAL ACTIVITY OF SOME NATURAL AND SYNTHETIC N6-SUBSTITUTED ADENOSINE DERIVATIVES (CYTOKININ RIBOSIDES)

In this Ph.D project, some natural N6 \u2013 substituted adenosine derivatives, cytokinin ribosides (CKRs) have been investigated with the aim to draw a profile of their biological activity. CKRs belong to a class of plant hormones playing various roles in many aspects of plant development. We chose the most representative among natural cytokinin ribosides, namely N6 \u2013 isopentenyl adenosine (iPAdo), kinetin riboside (KR), N6-benzyl adenosine (BA) and its hydroxylated derivative, \u3c1- topolin riboside (p-TR). In the first part of the thesis, the platelet anti aggregation activity CKRs has been evaluated in vitro as inhibitors of platelet aggregation. The activity has been interpreted by in silico docking experiments as due to interaction of CKRs with P2Y12 receptor. \u3c1 -Topolin riboside showed the best platelet anti aggregation activity and in silico interaction with P2Y12 receptor, followed by N6 \u2013 benzyladenosine. Some synthetic N6 \u2013 substituted adenosine derivatives have been synthesized and investigated as antagonists toward the human adenosine receptors A1, A2A, A2B, A3. p-TR again was the best antagonist of A2A and A2B adenosine receptors, both involved in the platelet aggregation mechanism. Synthetic N6 \u2013 substituted adenosine derivatives were antagonists of A3 adenosine receptor much stronger than natural CKRs. In a structure-activity study, the cytotoxic activity of natural CKRs and the synthetic analogues of p-TR were evaluated on 661W and Neuro2A cell lines trough Trypan blue and Tunel assays. Synthetic N6 \u2013 substituted adenosine derivatives showed a cytotoxic activity stronger than p-TR itself, that, in turn, exhibited the best apoptotic property. Many biological activities shown by the CKRs examined in this thesis could be related to an effect of these compounds on the cellular oxidative stress. Thus, as a part of the PhD project, the antioxidant profile of natural and synthetic CKRs has been investigated using the most common antioxidant tests in vitro. The heterogeneity of the results suggests in some instance a possible structure \u2013 activity relationship. However, since not all the compounds are active in every antioxidant assay, further characterization of the antioxidant profile of CKRs seems desirable, including suitable cellular assays

A compact light readout system for longitudinally segmented shashlik calorimeters

The longitudinal segmentation of shashlik calorimeters is challenged by dead zones and non-uniformities introduced by the light collection and readout system. This limitation can be overcome by direct fiber-photosensor coupling, avoiding routing and bundling of the wavelength shifter fibers and embedding ultra-compact photosensors (SiPMs) in the bulk of the calorimeter. We present the first experimental test of this readout scheme performed at the CERN PS-T9 beamline in 2015 with negative particles in the 1-5~GeV energy range. In this paper, we demonstrate that the scheme does not compromise the energy resolution and linearity compared with standard light collection and readout systems. In addition, we study the performance of the calorimeter for partially contained charged hadrons to assess the $e/\pi$ separation capability and the response of the photosensors to direct ionization.Comment: To appear in Nuclear Instruments and Methods in Physics Research,

The Dilemma of Pneumatosis Intestinalis with Pneumoperitoneum: Nonoperative or Surgical Management—Analysis of a Case

Pneumatosis intestinalis (PI) is an uncommon condition and can be associated with a wide spectrum of diseases, ranging from life-threatening to innocuous conditions. We report the case of a 46-year-old women coming to our attention for an acute abdominal pain, nausea, vomiting, constipation, and increased inflammatory marks, with a CT showing pneumoperitoneum and pneumatosis intestinalis. The previous diagnosis was advanced neoplasia of unknown origin. Despite the surgical intervention, which excluded an ischemic colitis, the patient died in the early postoperative period. The postmortem diagnosis was carcinoma of thymus gland, and the presence of pneumatosis was put down to metastasis nodes in the pulmonary parenchima. This case demonstrates the wide spectrum of presentation of pneumatosis intestinalis, the importance of a careful radiologic evaluation beside the clinical history, since the identification of correct pathogenesis and treatment can be very difficult

A narrow band neutrino beam with high precision flux measurements

The ENUBET facility is a proposed narrow band neutrino beam where lepton production is monitored at single particle level in the instrumented decay tunnel. This facility addresses simultaneously the two most important challenges for the next generation of cross section experiments: a superior control of the flux and flavor composition at source and a high level of tunability and precision in the selection of the energy of the outcoming neutrinos. We report here the latest results in the development and test of the instrumentation for the decay tunnel. Special emphasis is given to irradiation tests of the photo-sensors performed at INFN-LNL and CERN in 2017 and to the first application of polysiloxane-based scintillators in high energy physics.Comment: Poster presented at NuPhys2017 (London, 20-22 December 2017). 5 pages, 2 figure

Strong Reduction of the Effective Radiation Length in an Axially Oriented Scintillator Crystal

We measured a considerable increase of the emitted radiation by 120 GeV/c electrons in an axially oriented lead tungstate scintillator crystal, if compared to the case in which the sample was not aligned with the beam direction. This enhancement resulted from the interaction of particles with the strong crystalline electromagnetic field. The data collected at the external lines of the CERN Super Proton Synchrotron were critically compared to Monte Carlo simulations based on the Baier-Katkov quasiclassical method, highlighting a reduction of the scintillator radiation length by a factor of 5 in the case of beam alignment with the [001] crystal axes. The observed effect opens the way to the realization of compact electromagnetic calorimeters or detectors based on oriented scintillator crystals in which the amount of material can be strongly reduced with respect to the state of the art. These devices could have relevant applications in fixed-target experiments, as well as in satellite-borne γ telescopes

The ENUBET Beamline

The ENUBET ERC project (2016-2021) is studying a narrow band neutrino beam where lepton production can be monitored at single particle level in an instrumented decay tunnel. This would allow to measure $\nu_{\mu}$ and $\nu_{e}$ cross sections with a precision improved by about one order of magnitude compared to present results. In this proceeding we describe a first realistic design of the hadron beamline based on a dipole coupled to a pair of quadrupole triplets along with the optimisation guidelines and the results of a simulation based on G4beamline. A static focusing design, though less efficient than a horn-based solution, results several times more efficient than originally expected. It works with slow proton extractions reducing drastically pile-up effects in the decay tunnel and it paves the way towards a time-tagged neutrino beam. On the other hand a horn-based transferline would ensure higher yields at the tunnel entrance. The first studies conducted at CERN to implement the synchronization between a few ms proton extraction and a horn pulse of 2-10 ms are also described.Comment: Poster presented at NuPhys2018 (London 19-21 December 2018). 4 pages, 3 figure

A high-performance custom photodetection system to probe the light yield enhancement in oriented crystals

Scintillating homogeneous detectors represent the state of the art in electromagnetic calorimetry. Moreover, the currently neglected crystalline nature of the most common inorganic scintillators can be exploited to achieve an outstanding performance boost in terms of compactness and energy resolution. In fact, it was recently demonstrated by the AXIAL/ELIOT experiments that a strong reduction in the radiation length inside PWO, and a subsequent enhancement in the scintillation light emitted per unit thickness, are attained when the incident particle trajectory is aligned with a crystal axis within $\sim 1^\circ$. A SiPM-based system has been developed to directly probe this remarkable effect by measuring the scintillation light emitted by a PWO sample. The same concept could be applied to full-scale detectors that would feature a design significantly more compact than currently achievable and unparalleled resolution in the range of interest for present and future experiments

Cryogenic SiPM arrays for the DUNE photon detection system

In this paper we report on the characterization of SiPM tiles developed for the R & D on the DUNE Photon Detection System. The tiles were produced by Fondazione Bruno Kessler (FBK) employing NUV-HD-SF SiPMs. Special emphasis is given on cryo-reliability of the sensors, i.e. the stability of electric and mechanical properties after thermal cycles at room and 77K temperature. The characterization includes the determination of the I-V curve, a high sensitivity measurement of Dark Count Rate at different overvoltages, and correlated noise. The single p.e. sensitivity is measured as a function of the number of sensors connected to a single electronic channel, after amplification at 77K using a dedicated cold amplifier.Comment: 17 pages, 10 figures, 4 table, submitted to NIM-