OPERA tau neutrino charged current interactions

The OPERA experiment was designed to discover the vτ appearance in a vμ beam, due to neutrino oscillations. The detector, located in the underground Gran Sasso Laboratory, consisted of a nuclear photographic emulsion/lead target with a mass of about 1.25 kt, complemented by electronic detectors. It was exposed from 2008 to 2012 to the CNGS beam: an almost pure vμ beam with a baseline of 730 km, collecting a total of 1.8·1020 protons on target. The OPERA Collaboration eventually assessed the discovery of vμ→vτ oscillations with a statistical significance of 6.1 σ by observing ten vτ CC interaction candidates. These events have been published on the Open Data Portal at CERN. This paper provides a detailed description of the vτ data sample to make it usable by the whole community.

Assessment of Residual Radioactivity by a Comprehensive Wireless, Wearable Device in Thyroid Cancer Patients Undergoing Radionuclide Therapy and Comparison With the Results of a Home Device: A Feasibility Study

Objective: To investigate the feasibility of using a wireless wearable device (WD) in differentiated thyroid cancer (DTC) patients undergoing radionuclide therapy with I-131 (RAI) and protected hospitalization, this study compared the measurements of residual radioactivity obtained with those registered by a permanent environmental home device (HD). Methods: Twenty consecutive patients undergoing RAI hospitalized in restricted, controlled areas were enrolled. The patients underwent comprehensive monitoring of vital/nonvital parameters. We obtained 45580± 13 measurements from the WD, detecting the residual radioactivity for each patient during approximately 56 hours of hospitalization, collecting data 53 times per hour. The samples, collected during daily activities, were averaged every two hours, and the results correlated with those from the HD. Bland-Altman analysis was also used to evaluate the agreement between the two techniques. Results: A significant relationship between the WD and HD was observed (r = 0.96, p < 0.0001). Bland-Altman analysis recognized the agreement between measurements by the WD and HD. The mean value at the end of the first day of hospitalization was 80.81 microSv/h and 60.77 microSv/h (p = ns for WD and HD), whereas those at the end of the second day were 47.08 and 24.96 (p = ns). In the generalized linear model (GLM), a similar trend in performance across time was found with the two techniques. Conclusion: This study demonstrates good agreement between the residual radioactivity measures estimated by the WD and HD modalities, rendering them interchangeable. This approach will allow both the optimization of medical staff exposure and safer patient discharge. Abbreviations: wireless device (WD); differentiated thyroid cancer (DTC); radionuclide therapy with I-131 (RAI); home device (HD); generalized linear model (GLM).

Space-time Bayesian analysis of the environmental impact of a dismissing nuclear power plant

The assessment of the radiological impact of decommissioning activities at a nuclear power plant requires a detailed analysis of the distribution of radionuclides in the environment surrounding it. The present work concerns data of three campaigns carried out during the last twenty years in the plain of the Garigliano river surrounding the Garigliano Nuclear Power Plant (GNPP), which is located in Southern Italy and shut down in 1979. Moreover, some data from surveys held in the eighties, across the Chernobyl accident, have been taken in account. The results for the soil samples, in particular for ¹³⁷Cs and ²³⁶U specific activity, were analyzed for their extension in space and in time. Some of the problems related to the classical analysis of environmental radiological data (non-normal distribution of the values, small number of sample points, multiple comparison and presence of values lesser than the minimum detectable activity) have been overcome with the use of Bayesian methods. The scope of the paper is threefold: (1) to introduce the data of the last campaign held in the Garigliano plain; (2) to insert these data in a larger spatio-temporal frame; (3) to show how the Bayesian approach can be applied to radiological environmental surveys, stressing out its advantages over other approaches, using the data of the campaigns. The results show that radionuclides specific activity in soil is dominated by the natural sources with the contribution of the atmospheric fallout. A detailed study was performed on the ¹³⁷Cs data to evaluate both their statistical distribution and the trend over the space and the time. It results that (i) no new contribution there was in the last decades, (ii) specific activity values of the area surrounding the GNPP are consistent with those obtained in other farther areas, (iii) the effective depletion half-life factor for ¹³⁷Cs is much lower than the half-life of the radionuclide.

AMS assessment of U-contamination of structural materials of the Garigliano NPP under decommissioning

The assessment of the radiological impact of decommissioning activities at a Nuclear Power Plant requires a detailed mapping of the distribution of radionuclides both in the environment surrounding the NPP and in its structural material. The detection of long-lived actinide isotopes and possibly the identification of their origin is particularly interesting and valuable if ultrasensitive measurement of the relative abundance of U isotopes is performed via Accelerator Mass Spectrometry (AMS). In this paper we present an investigation carried out on the structural materials of the Garigliano NPP aiming to determine the abundance of ^235,236,238U in the various compartments of the plant buildings under decommissioning. Since the expected values both for isotopic ratios and total U concentrations range over different orders of magnitude, we have developed a novel methodology for the measurement of ^234,235U/²³⁸U isotopic ratios in low U concentration samples. This allowed a systematic investigation of the distribution of all U isotopes in concrete and metal matrices of the NPP. The behavior of ^235,236U/²³⁸U isotopic ratios in the different compartments of the NPP is discussed. The correlation of these ratios with ⁶⁰Co and ¹³⁷Cs specific activities is also studied to show a different behavior for concrete and metal samples. These data represent a very valuable information to direct the decommissioning procedures under course.

Final Results of the OPERA Experiment on ν_{τ} Appearance in the CNGS Neutrino Beam

The OPERA experiment was designed to study ν_{μ}→ν_{τ} oscillations in the appearance mode in the CERN to Gran Sasso Neutrino beam (CNGS). In this Letter, we report the final analysis of the full data sample collected between 2008 and 2012, corresponding to 17.97×10^{19} protons on target. Selection criteria looser than in previous analyses have produced ten ν_{τ} candidate events, thus reducing the statistical uncertainty in the measurement of the oscillation parameters and of ν_{τ} properties. A multivariate approach for event identification has been applied to the candidate events and the discovery of ν_{τ} appearance is confirmed with an improved significance level of 6.1σ. |Δm_{32}^{2}| has been measured, in appearance mode, with an accuracy of 20%. The measurement of the ν_{τ} charged-current cross section, for the first time with a negligible contamination from ν[over ¯]_{τ}, and the first direct evidence for the ν_{τ} lepton number are also reported.

Discovery of τ Neutrino Appearance in the CNGS Neutrino Beam with the OPERA Experiment

The OPERA experiment was designed to search for ν_{μ}→ν_{τ} oscillations in appearance mode, i.e., by detecting the τ leptons produced in charged current ν_{τ} interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the ν_{μ}→ν_{τ} appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ν_{τ} candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of ν_{μ}→ν_{τ} oscillations in appearance mode with a significance larger than 5σ.

Long-term clinical results and MRI changes after tendon ball arthroplasty for advanced Kienbock's disease

The purpose of this study was to assess the long-term clinical results and morphological changes after tendon ball arthroplasty for advanced Kienböck's disease. Twenty-six patients were reviewed, with a mean follow-up interval of 125 months (range 50-226). At follow-up, mean score on the Disabilities of the Arm, Shoulder, and Hand questionnaire was 7.7 and mean visual analogue scale score for pain was 1. Mean carpal height ratio was significantly reduced with respect to the pre-operative value. On magnetic resonance imaging scans, cartilage damage, synovitis, and erosive or oedematous changes in the bones were detected in most patients. Calcification in the defect filled by the tendon ball was seen in all patients. Narrowing of the radioscaphoid joint and the presence of intercarpal synovitis were negatively associated with clinical outcome. Tendon ball arthroplasty in advanced Kienböck's disease results in long-term satisfactory clinical outcomes, despite widespread changes in the bones and joints within the wrist.

Interleukin (IL)-6 and receptor activator of nuclear factor (NF)-kappaB ligand (RANKL) are increased in the serum of a patient with primary pachydermoperiostosis

Primary pachydermoperiostosis (PDP) is a rare syndrome, characterized by digital clubbing, periostosis, and pachydermia. We have evaluated biochemical bone turnover markers, including components of interleukin-6 (IL-6) and osteoprotegerin/receptor activator of nuclear factor (NF)-kappaB ligand (OPG/RANKL) systems, in an 18-year-old man affected by primary PDP. The acute phase of the disease was characterized in our patient by high serum levels of IL-6 and RANKL. The observed high serum levels of these parameters are associated with increased values in markers of bone resorption (degradation products of C-terminal telopeptides of type-I collagen and urinary hydroxyproline/creatinine ratio) and reduced serum levels of bone alkaline phosphatase, a marker of bone formation. Serum levels of osteotrophic hormones were in the normal range. Our data suggest that, despite the radiographic findings, the acute phase of primary PDP is characterized by increased bone resorption, probably mediated by IL-6 and RANKL.

[The optimization of the treatment and timing of the intervention by a nephrologist in pre-dialytic chronic renal insufficiency]

BACKGROUND

Early referral to nephrologists of patients with chronic renal failure (CRF) reduces morbidity and mortality in dialysis. Aim of this work is to evaluate the condition of early and late referral, and whether the two different conditions can affect the treatments.

MATERIALS AND METHODS

This is a prospective study with a 12-month follow-up period. During this time, we verified the prevalence of patients with serum creatinine > 1.5 mg/dL (CRF patients) and the condition of early or late referral, defined as referral to nephrologists for > or < 3 times during follow up, respectively. Diagnosis of diabetes mellitus and/or arterial hypertension, and the use of antihypertensive drugs, insulin, hypoproteic diet and erythropoietin was recorded in each patient.

RESULTS

CRF (mean serum creatinine value = 2.11+/-1.52 mg/dL) was observed in 190 patients aged 72.05+/-11.62 years. The prevalence of CRF was 4718 pmp. Diabetes and hypertension were diagnosed in 107 subjects (56.3%) and 152 subjects (80%), respectively. Only 74.2% (no. 141) of the patients with CRF was habitually followed by the nephrologist and the frequency was directly correlated to the degree of CRF: 100% of the patients with Creatinine Clearance (Cr Cl) < 25 mL/min, 70% with Cr Cl >25 < 50, and 0% with Cr Cl >50 < 80 mL/min. Early referral was coupled with a wider use of a hypoproteic diet, erythropietin, and the association ACE-I + Angiotensin II receptor antagonists.

CONCLUSION

In conclusion, our data show a prevalence of CRF that is at least 5 times greater than that of dialysis patients. The condition of late referral is present in about 30% of the CRF population from the time of the initial phases of renal disease. Referral time affects the modalities of the treatment.

[The identification of the criteria of malignancy and the tissue characterization of expansive processes in periskeletal soft tissues. The current role of magnetic resonance]

INTRODUCTION

Expansive masses arising from periskeletal soft tissues are a frequent challenge for the imaging specialist. Lesion diagnosis and characterization, and the assessment of benign/malignant nature are very important factors for treatment planning. We investigated MR capabilities in distinguishing benign from malignant masses and for histopathologic lesion characterization, also in the light of the latest most authoritative literature reports.

MATERIAL AND METHODS

February 1995 to November 1997, we examined 237 patients with known space-occupying lesions arising from periskeletal soft tissues. T1- and PD/T2-weighted SE images were acquired on the most suitable planes. The findings were independently evaluated by two groups of radiologists who were asked a benignity/malignancy judgment based on specific morphological criteria and then a presumptive histopathologic characterization. The results were then compared with pathologic findings.

RESULTS

We had high agreement rates for benignity/malignancy judgements, with only < or = 3.8% error rates. In contrast, rates were quite variable for histopathologic characterization and differed greatly by lesion type. The lesions, defined as malignant, could not be characterized histologically in approximately 18% of cases by both groups.

DISCUSSION AND CONCLUSIONS

Our results, which are in substantial agreement with the recent authoritative literature, confirm MRI as an extremely reliable tool for distinguishing benign from malignant expansive masses arising from periskeletal soft tissues. On the contrary, MRI exhibits good specificity in histopathologic characterization only for the masses with such development as to permit identification of the anatomical compartment of origin, which are usually benign, as well as the masses with typical or pathognomonic tissue signal.

[Magnetic resonance in the identification and assessment of extent and severity of bone contusion damage: comparison of several types of imaging (SE/T1, GE/T2 and SE/T1) with fat suppression]

INTRODUCTION

Bone marrow contusion is a common cause of chronic joint pain in the post-traumatic knee; it is usually associated with meniscal and/or ligament damage but it may also be the only abnormal sign. In this condition MRI plays a fundamental role because it is the only imaging technique which can diagnose it and accurately assess its extent and any cortical bone and/or cartilage involvement. We investigated the diagnostic potentials of 3 MR sequences in identifying and assessing the extent of bone contusion.

MATERIAL AND METHODS

January, 1994, to December, 1997, we performed 539 MR examinations of the knee on 478 patients with chronic joint pain following trauma. We used T1-weighted SE, T2*-weighted GE and T1-weighted SE sequences with fat saturation (fs), paying great attention to technical parameter setting. The images were retrospectively reviewed by groups of radiologists using 2 semi-objective evaluation systems: a qualitative assessment to grade the ease of detection of the contusion with each sequence and a quantitative assessment of contusion extent and of osteochondral involvement, if any, again for each sequence.

RESULTS

The qualitative analysis showed that GE and SE-fs sequences were superior to the conventional ones in identifying bone contusion foci; GE sequences tended to overestimate the number of poorly depictable lesions relative to SE-fs ones. The quantitative analysis showed that the conventional sequences tend to underestimate the foci extent, while GE and SE-fs sequences performed nearly the same in the assessment of high-grade lesions. The number of low-midgrade lesions was overestimated by GE sequences relative to SE-fs ones.

DISCUSSION AND CONCLUSIONS

GE and SE-fs sequences permit accurate studies of bone contusions. Diagnostic efficacy is increased by enhancing the signal from non-fatty structures within a tissue rich in fat: the quantitative reduction of the non-fatty structural component and/or its replacement with abnormal components is thus best shown. Fat-suppression sequences were more accurate in defining lesion size, which is also related to low susceptibility to the artifacts from extrinsic and especially intrinsic structural inhomogeneities. In contrast, GE sequences demonstrated high susceptibility, which caused poorer definition of the contusion borders and, consequently, overestimation of the lesion size.