Search

180 m Ta is the longest-lived metastable state presently known. Its decay has not been observed yet. In this work, we report a new result on the decay of 180 m Ta obtained with a 2015.12-g tantalum sample measured for 527.7 d with an ultra-low background HPGe detector in the STELLA laboratory of the Laboratori Nazionali del Gran Sasso (LNGS), in Italy. Before the measurement, the sample has been stored deep-underground for ten years, resulting in subdominant background contributions from cosmogenically activated 182 Ta . We observe no signal in the regions of interest and set half-life limits on the process for the two channels EC and β - : T 1 / 2 , EC > 1.6 × 10 18 year and T 1 / 2 , β - > 1.1 × 10 18 year (90% C. I.), respectively. We also set the limit on the γ de-excitation / IC channel: T 1 / 2 , IC > 4.1 × 10 15 year (90% C. I.). These are, as of now, the most stringent bounds on the decay of 180 m Ta worldwide. Finally, we test the hypothetical scenarios of de-excitation of 180 m Ta by cosmological Dark Matter and constrain new parameter space for strongly-interacting dark-matter particle with mass up to 10 5 GeV. [ABSTRACT FROM AUTHOR]

The response of particle detectors to different types of radiation is not necessarily identical and, in some cases, neglecting this behavior can lead to a misinterpretation of the acquired data. While commercial radioactive sources are in general suitable to investigate the response to β 's and γ 's, in the case of α 's the need for custom-made sources arises from the intrinsic properties of α radiation, which imposes that the emitter directly faces the detector. In this work, we show how to flexibly produce α sources to be employed in multiple studies of detector characterization. These are obtained starting from a set of primary sources obtained from the collection of radioactive 228 Ra ions at the ISOLDE facility at CERN. We illustrate the potential of this technique with practical cases of application to scintillators and bolometric detectors and examples of the results obtained so far. [ABSTRACT FROM AUTHOR]

The Cryogenic Underground Observatory for Rare Events (CUORE) is a bolometric experiment for neutrinoless double-beta decay in 130Te search, currently taking data at the underground facility of Laboratori Nazionali del Gran Sasso (LNGS). The CUORE cryostat successfully cooled down a mass of about 1 ton at ∼7mK, delivering a uniform and constant base temperature. This result marks a fundamental milestone in low-temperature detector techniques, opening the path for future ton-scale bolometric experiments searching for rare events. In this paper, we present the CUORE cryogenic infrastructure, briefly describing its critical subsystems. [ABSTRACT FROM AUTHOR]

The cryogenic underground observatory for rare events (CUORE) is a 1-ton scale bolometric experiment whose detector consists of an array of 988 TeO $$_2$$ crystals arranged in a cylindrical compact structure of 19 towers. This will be the largest bolometric mass ever operated. The experiment will work at a temperature around or below 10 mK. CUORE cryostat consists of a cryogen-free system based on pulse tubes and a custom high power dilution refrigerator, designed to match these specifications. The cryostat has been commissioned in 2014 at the Gran Sasso National Laboratories and reached a record temperature of 6 mK on a cubic meter scale. In this paper, we present results of CUORE commissioning runs. Details on the thermal characteristics and cryogenic performances of the system will be also given. [ABSTRACT FROM AUTHOR]

Well-established histopathological prognostic factors are lacking in primary central nervous system (CNS) lymphomas (PCNSL). The present study investigated the presence and prognostic role of tumour necrosis (TN) and reactive perivascular T-cell infiltrate (RPVI), defined as a rim of small reactive T-lymphocytes occurring alone or located between the vascular wall and large neoplastic cells, in tumour samples from 100 immunocompetent patients with PCNSL. World Health Organization histotypes of the patients were: 96 diffuse large B-cell lymphomas, two Burkitt-like lymphomas, one anaplastic large T-cell lymphoma and one unclassified B-cell lymphoma. TN was observed in 24 (24%) cases and RPVI in 26 (36%) of 73 assessable cases. Patients with RPVI-positive lesions exhibited a significantly better overall survival (OS) than patients with RPVI-negative lymphoma, particularly among patients treated with high-dose methotrexate-based chemotherapy (3-year OS: 59 ± 14% vs. 42 ± 9%, P = 0·02). By contrast, the presence of TN did not demonstrate prognostic significance. Multivariate analysis confirmed an independent association between RPVI and survival. In conclusion, the presence of RPVI is independently associated with survival in PCNSL. This parameter can be easily and routinely assessed at diagnosis on histopathological specimens. [ABSTRACT FROM AUTHOR]

Limited information on salvage treatment in patients affected by pancreatic cancer is available. At failure, about half of the patients present good performance status (PS) and are candidate for further treatment. Patients >18 years, PS >or=50, with metastatic pancreatic adenocarcinoma previously treated with gemcitabine-containing chemotherapy, and progression-free survival (PFS) <12 months received a combination of raltitrexed (3 mg m(-2)) and oxaliplatin (130 mg m(-2)) every 3 weeks until progression, toxicity, or a maximum of six cycles. A total of 41 patients received 137 cycles of chemotherapy. Dose intensity for both drugs was 92% of the intended dose. Main grade >2 toxicity was: neutropenia in five patients (12%), thrombocytopenia, liver and vomiting in three (7%), fatigue in two (5%). In total, 10 patients (24%) yielded a partial response, 11 a stable disease. Progression-free survival at 6 months was 14.6%. Median survival was 5.2 months. Survival was significantly longer in patients with previous PFS >6 months and in patients without pancreatic localisation. A clinically relevant improvement of quality of life was observed in numerous domains. Raltitrexed-oxaliplatin regimen may constitute a treatment opportunity in gemcitabine-resistant metastatic pancreatic cancer. Previous PFS interval may allow the identification of patients who are more likely to benefit from salvage treatment. [ABSTRACT FROM AUTHOR]

Although high-dose methotrexate (HD-MTX) is the most effective drug against primary CNS lymphomas (PCNSL), outcome-determining variables related to its administration schedule have not been defined. The impact on toxicity and outcome of the area under the curve (AUCMTX), dose intensity (DIMTX) and infusion rate (IRMTX) of MTX and plasmatic creatinine clearance (CLcrea) was investigated in a retrospective series of 45 PCNSL patients treated with three different HD-MTX-based combinations. Anticonvulsants were administered in 31 pts (69%). Age >60 years, anticonvulsant therapy, slow IRMTX (?800?mgm-2h-1), and reduced DIMTX (?1000?mgm-2wk-1) were significantly correlated with low AUCMTX values. Seven patients (16%) experienced severe toxicity, which was independently associated with slow CLcrea. A total of 18 (40%) patients achieved complete remission after chemotherapy, which was independently associated with slow CLcrea. In all, 22 patients were alive at a median follow-up of 31 months, with a 3-year OS of 40±9%; slow CLcrea and AUCMTX >1100?µmol?hl-1 were independently associated with a better survival. Slow CLcrea and high AUCMTX are favourable outcome-determining factors in PCNSL, while slow CLcrea is significantly related to higher toxicity. AUCMTX significantly correlates with age, anticonvulsant therapy, IRMTX, and DIMTX. These findings, which seem to support the choice of an MTX dose ?3?gm-2 in a 4-6-h infusion, every 3-4 weeks, deserve to be assessed prospectively in future trials. MTX dose adjustments in patients with fast CLcrea should be investigated.British Journal of Cancer (2004) 90, 353-358. doi:10.1038/sj.bjc.6601472 www.bjcancer.com [ABSTRACT FROM AUTHOR]

The Raf-MEK-ERK signalling pathway controls fundamental cellular processes including proliferation, differentiation and survival. It remains enigmatic how this pathway can reliably convert a myriad of extracellular stimuli in specific biological responses. Recent results have shown that the Raf family isoforms A-Raf, B-Raf and Raf-1 have different physiological functions. Here we review how Raf isozyme diversity contributes to the specification of functional diversity, in particular regarding the role of Raf isozymes in cancer.British Journal of Cancer (2004) 90, 283-288. doi:10.1038/sj.bjc.6601488 www.bjcancer.com [ABSTRACT FROM AUTHOR]