Dephasing due to electron-electron interaction in a diffusive ring

We study the effect of the electron-electron interaction on the weak localization correction of a ring pierced by a magnetic flux. We compute exactly the path integral giving the magnetoconductivity for an isolated ring. The results are interpreted in a time representation. This allows to characterize the nature of the phase coherence relaxation in the ring. The nature of the relaxation depends on the time regime (diffusive or ergodic) but also on the harmonics $n$ of the magnetoconductivity. Whereas phase coherence relaxation is non exponential for the harmonic $n=0$, it is always exponential for harmonics $n\neq0$. Then we consider the case of a ring connected to reservoirs and discuss the effect of connecting wires. We recover the behaviour of the harmonics predicted recently by Ludwig & Mirlin for a large perimeter (compared to the Nyquist length). We also predict a new behaviour when the Nyquist length exceeds the perimeter.Comment: 21 pages, RevTeX4, 8 eps figures; version of 10/2006 : eqs.(100-102) of section V.C correcte

Venous Manometry as an Adjunct for Diagnosis and Multimodal Management of Intracranial Hypertension due to Meningioma Compressing Sigmoid Sinus

Intracranial venous hypertension is a rare presentation of meningiomas in the transversesigmoid sinus region. We describe a case of a young patient presenting with intracranial hypertension due to a meningioma causing compression of the dominant sigmoid sinus. We were able to document the cerebral venous pressure gradient across the lesion confirming our hypothesis that compression of the sigmoid sinus from the meningioma was the cause of intracranial hypertension. The patient is a 17-year-old male who presented with intracranial hypertension due to meningioma at the right dominant sigmoid sinus, which was treated by a Simpson grade IV surgical resection followed by stereotactic radiosurgery. Following treatment, his papilledema resolved and he remains symptom-free at 18 months. In conclusion, venous manometry is a useful adjunct to diagnose intracranial hypertension in non-idiopathic causes of intracranial hypertension. A multimodal management approach of intracranial hypertension due to outflow obstruction from the dominant sinus led to an excellent recovery on follow up

The EEE Project

The new experiment ``Extreme Energy Events'' (EEE) to detect extensive air showers through muon detection is starting in Italy. The use of particle detectors based on Multigap Resistive Plate Chambers (MRPC) will allow to determine with a very high accuracy the direction of the axis of cosmic ray showers initiated by primaries of ultra-high energy, together with a high temporal resolution. The installation of many of such 'telescopes' in numerous High Schools scattered all over the Italian territory will also allow to investigate coincidences between multiple primaries producing distant showers. Here we present the experimental apparatus and its tasks.Comment: 4 pages, 29th ICRC 2005, Pune, Indi

Physical-Chemical Characteristics of Cutin Separated from Tomato Waste for the Preparation of Bio-lacquers

Green chemistry protocols are proposed to produce high-value chemicals from waste tomatoes. Long-chain hydroxy fatty acids (called cutin acids), in particular the 10,16-dihydroxyhexadecanoic acid and its oligomers, could be innovative building-block chemicals for the synthesis of novel bio-resins and lacquers suitable as internal protective coating for metal food packaging. However, these natural compounds are not currently commercially available. This study investigates the possibility of extracting cutin acids from tomato peels without the use of organic solvents and by an efficient, cost-effective, and environmentally safe method amenable to industrial scale-up. The first route investigated was based on alkaline hydrolysis of the tomato cuticle. The second involved the acid free-selective precipitation of cutin. Finally, cutin was isolated by hydrogen peroxide-assisted hydrolysis. GC-MS analysis revealed the main chemical compound isolated by all methods to be 10,16-dihydroxyhexadecanoic acid, the principal component of tomato cutin, with extraction yields ranging from 81 to 96%. Products are different in terms of appearance, solubility, the degree of crosslinking observed and molecular weight, as shown by GPC analysis. Furthermore, the products extracted were characterized by means of FT-IR spectroscopy and thermal analysis. The cutin obtained through alkaline hydrolysis results the best raw material for bio-resin preparation

New Eco-gas mixtures for the Extreme Energy Events MRPCs: results and plans

The Extreme Energy Events observatory is an extended muon telescope array, covering more than 10 degrees both in latitude and longitude. Its 59 muon telescopes are equipped with tracking detectors based on Multigap Resistive Plate Chamber technology with time resolution of the order of a few hundred picoseconds. The recent restrictions on greenhouse gases demand studies for new gas mixtures in compliance with the relative requirements. Tetrafluoropropene is one of the candidates for tetrafluoroethane substitution, since it is characterized by a Global Warming Power around 300 times lower than the gas mixtures used up to now. Several mixtures have been tested, measuring efficiency curves, charge distributions, streamer fractions and time resolutions. Results are presented for the whole set of mixtures and operating conditions, %. A set of tests on a real EEE telescope, with cosmic muons, are being performed at the CERN-01 EEE telescope. The tests are focusing on identifying a mixture with good performance at the low rates typical of an EEE telescope.Comment: 8 pages, 6 figures, proceedings for the "XIV Workshop on Resistive Plate Chambers and Related Detectors" (19-23 February 2018), Puerto Vallarta, Jalisco State, Mexic

A simulation tool for MRPC telescopes of the EEE project

The Extreme Energy Events (EEE) Project is mainly devoted to the study of the secondary cosmic ray radiation by using muon tracker telescopes made of three Multigap Resistive Plate Chambers (MRPC) each. The experiment consists of a telescope network mainly distributed across Italy, hosted in different building structures pertaining to high schools, universities and research centers. Therefore, the possibility to take into account the effects of these structures on collected data is important for the large physics programme of the project. A simulation tool, based on GEANT4 and using GEMC framework, has been implemented to take into account the muon interaction with EEE telescopes and to estimate the effects on data of the structures surrounding the experimental apparata.A dedicated event generator producing realistic muon distributions, detailed geometry and microscopic behavior of MRPCs have been included to produce experimental-like data. The comparison between simulated and experimental data, and the estimation of detector resolutions is here presented and discussed

Multicentric assessment of safety and efficacy of combinatorial adjuvant brain metastasis treatment by intraoperative radiotherapy and immunotherapy

Purpose Following surgical resection of brain metastases (BMs), intraoperative radiation therapy (IORT) provides a promising alternative to adjuvant external beam radiation therapy (EBRT) by enabling superior organ at risk preservation, reduction of in-hospital times and timely admission to subsequent systemic treatments, which increasingly comprise novel targeted immunotherapeutic approaches. We sought to assess safety and efficacy of IORT in combination with immune checkpoint inhibitors (ICIs) and other targeted therapies (TTs). Methods In a multicentric approach incorporating individual patient data from six international IORT centers, all patients with BMs undergoing IORT were retrospectively assessed for combinatorial treatment with ICIs/TTs and evaluated for toxicity and cumulative rates, including wound dehiscence, radiation necrosis (RN), leptomeningeal spread (LMS), local control (LC), distant brain progression (DBP) and estimated overall survival (OS). Results A total of 103 lesions with a median diameter of 34 mm receiving IORT combined with immunomodulatory systemic treatment or other TTs were included. The median follow up was 13.2 (1.2-102.4) months and the median IORT dose was 25 (18-30) Gy prescribed to the applicator surface. There was one grade 3 adverse event related to IORT recorded (2.2%). A 4.9% cumulative RN rate was observed. The 1-year LCR was 98.0% and the 1-year DBP-free rate 60.0%. Median time to DBP was 5.5 (1.0-18.5) months in the subgroup of patients experiencing DBP and the cumulative LMS rate was 4.9%. The median estimated OS was 26 (1.2-not reached) months with a 1-year survival rate of 74.0%. Early initiation of IT/TT was associated with a non-significant trend towards improved DBP rate and OS. Conclusion The combination of ICIs/TT with IORT for resected BMs does not seem to increase toxicity, while yielding encouraging local control outcomes in the difficult-to-treat subgroup of larger BMs. Time gaps between surgery and systemic treatment could be shortened or avoided. The definitive role of IORT in local control after BM resection will be defined in a prospective trial

The Extreme Energy Events HECR array: status and perspectives

The Extreme Energy Events Project is a synchronous sparse array of 52 tracking detectors for studying High Energy Cosmic Rays (HECR) and Cosmic Rays-related phenomena. The observatory is also meant to address Long Distance Correlation (LDC) phenomena: the network is deployed over a broad area covering 10 degrees in latitude and 11 in longitude. An overview of a set of preliminary results is given, extending from the study of local muon flux dependance on solar activity to the investigation of the upward-going component of muon flux traversing the EEE stations; from the search for anisotropies at the sub-TeV scale to the hints for observations of km-scale Extensive Air Shower (EAS).Comment: XXV ECRS 2016 Proceedings - eConf C16-09-04.