2,610 research outputs found

    Long-term evolution of the heliospheric magnetic field inferred from cosmogenic 44^{44}Ti activity in meteorites

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    Typical reconstructions of historic heliospheric magnetic field (HMF) BHMFB_{\rm HMF} are based on the analysis of the sunspot activity, geomagnetic data or on measurement of cosmogenic isotopes stored in terrestrial reservoirs like trees (14^{14}C) and ice cores (10^{10}Be). The various reconstructions of BHMFB_{\rm HMF} are however discordant both in strength and trend. Cosmogenic isotopes, which are produced by galactic cosmic rays (GCRs) impacting on meteoroids and whose production rate is modulated by the varying HMF convected outward by the solar wind, may offer an alternative tool for the investigation of the HMF in the past centuries. In this work, we aim to evaluate the long-term evolution of BHMFB_{\rm HMF} over a period covering the past twenty-two solar cycles by using measurements of the cosmogenic 44^{44}Ti activity (τ1/2=59.2±0.6\tau_{1/2} = 59.2 \pm 0.6 yr) measured in 20 meteorites which fell between 1766 and 2001. Within the given uncertainties, our result is compatible with a HMF increase from 4.87−0.30+0.244.87^{+0.24}_{-0.30} nT in 1766 to 6.83−0.11+0.136.83^{+0.13}_{-0.11} nT in 2001, thus implying an overall average increment of 1.96−0.35+0.431.96^{+0.43}_{-0.35} nT over 235 years since 1766 reflecting the modern Grand maximum. The BHMFB_{\rm HMF} trend thus obtained is then compared with the most recent reconstructions of the near-Earth heliospheric magnetic field strength based on geomagnetic, sunspot number and cosmogenic isotope data.Comment: Accepted for publication in Astronomy and Astrophysic

    Background suppression in massive TeO2_2 bolometers with Neganov-Luke amplified light detectors

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    Bolometric detectors are excellent devices for the investigation of neutrinoless double-beta decay (0νββ\nu\beta\beta). The observation of such decay would demonstrate the violation of lepton number, and at the same time it would necessarily imply that neutrinos have a Majorana character. The sensitivity of cryogenic detectors based on TeO2_2 is strongly limited by the alpha background in the region of interest for the 0νββ\nu\beta\beta of 130^{130}Te. It has been demonstrated that particle discrimination in TeO2_2 bolometers is possible measuring the Cherenkov light produced by particle interactions. However an event-by-event discrimination with NTD-based light detectors has to be demonstrated. We will discuss the performance of a highly-sensitive light detector exploiting the Neganov-Luke effect for signal amplification. The detector, being operated with NTD-thermistor and coupled to a 750 g TeO2_2 crystal, shows the ability for an event-by-event identification of electron/gamma and alpha particles. The extremely low detector baseline noise, RMS 19 eV, demonstrates the possibility to enhance the sensitivity of TeO2_2-based 0νββ\nu\beta\beta experiment to an unprecedented level

    Serum levels of tumour associated glycoprotein (TAG 72) in patients with gynaecological malignancies.

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    Serum levels of TAG 72 were measured in 726 serum samples from patients with benign and malignant gynaecological conditions in order to evaluate the clinical usefulness of TAG 72 alone or in combination with other tumour markers. Sixty-six per cent of patients with ovarian cancer showed abnormal concentrations of TAG 72 antigen. A good correlation was also found between serial TAG 72 values and the clinical course of disease during chemotherapy and follow-up. In cervical and endometrial cancer abnormal TAG 72 values occurred in 23% and 14% of cases, while none of the patients with breast cancer had abnormal TAG 72 levels. Among patients with benign disease only one out of 12 patients (8%) with benign ovarian tumours and one of 15 patients with uterine fibromyomatosis (7%) showed high TAG 72 serum levels. However, the determination of TAG 72 did not increase the sensitivity of CA 125 and squamous cell carcinoma antigen (SCC), in ovarian and cervical cancer, respectively. The systemic administration of recombinant interferon alpha-2b to 15 patients with ovarian cancer and different basal levels of TAG 72 did not increase serum levels of the antigen

    Nm23 expression in endometrial and cervical cancer: inverse correlation with lymph node involvement and myometrial invasion.

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    The expression of nm23 has been shown to correlate in some solid tumours with their metastatic potential and to be associated with a favourable prognosis in human breast cancer and melanoma. In breast and ovarian cancer nm23 expression is also correlated with lymph node involvement. We analysed the expression of nm23-H1 and -H2 in normal endometrium and in endometrial and cervical cancer by both Northern and Western blotting. Cellular localisation of Nm23-H1 was visualised by immunohistochemistry mostly in the cytoplasm. Both isoforms of Nm23 were present in all the samples analysed, and a clear direct correlation between Nm23-H1 and -H2 levels was evident. Median nm23-H2 levels were higher than than -H1 levels in both tissues. Cervical cancer patients with lymph node involvement were shown to have significantly lower protein levels of Nm23 (P < 0.007 for H1 and P < 0.009 for H2), and a similar trend was also evident in endometrial cancer. Furthermore, the degree of myometrial invasion in endometrial cancer patients was also inversely correlated with Nm23-H1 levels of expression (P < 0.003). Nm23 level may therefore be taken into consideration as a new marker in the prognostic characterisation and in the treatment planning of uterine tumour patients

    Rejection of randomly coinciding events in Li2_2100^{100}MoO4_4 scintillating bolometers using light detectors based on the Neganov-Luke effect

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    Random coincidences of nuclear events can be one of the main background sources in low-temperature calorimetric experiments looking for neutrinoless double-beta decay, especially in those searches based on scintillating bolometers embedding the promising double-beta candidate 100^{100}Mo, because of the relatively short half-life of the two-neutrino double-beta decay of this nucleus. We show in this work that randomly coinciding events of the two-neutrino double decay of 100^{100}Mo in enriched Li2_2100^{100}MoO4_4 detectors can be effectively discriminated by pulse-shape analysis in the light channel if the scintillating bolometer is provided with a Neganov-Luke light detector, which can improve the signal-to-noise ratio by a large factor, assumed here at the level of ∼750\sim 750 on the basis of preliminary experimental results obtained with these devices. The achieved pile-up rejection efficiency results in a very low contribution, of the order of ∼6×10−5\sim 6\times10^{-5} counts/(keV⋅\cdotkg⋅\cdoty), to the background counting rate in the region of interest for a large volume (∼90\sim 90 cm3^3) Li2_2100^{100}MoO4_4 detector. This background level is very encouraging in view of a possible use of the Li2_2100^{100}MoO4_4 solution for a bolometric tonne-scale next-generation experiment as that proposed in the CUPID project

    Sulforaphane-loaded ultradeformable vesicles as a potential natural nanomedicine for the treatment of skin cancer diseases

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    Sulforaphane is a multi-action drug and its anticancer activity is the reason for the continuous growth of attention being paid to this drug. Sulforaphane shows an in vitro antiproliferative activity against melanoma and other skin cancer diseases. Unfortunately, this natural compound cannot be applied in free form on the skin due to its poor percutaneous permeation determined by its physico-chemical characteristics. The aim of this investigation was to evaluate ethosomes® and transfersomes® as ultradeformable vesicular carriers for the percutaneous delivery of sulforaphane to be used for the treatment of skin cancer diseases. The physico-chemical features of the ultradeformable vesicles were evaluated. Namely, ethosomes® and transfersomes® had mean sizes &lt;400 nm and a polydispersity index close to 0. The stability studies demonstrated that the most suitable ultradeformable vesicles to be used as topical carriers of sulforaphane were ethosomes® made up of ethanol 40% (w/v) and phospholipon 90G 2% (w/v). In particular, in vitro studies of percutaneous permeation through human stratum corneum and epidermis membranes showed an increase of the percutaneous permeation of sulforaphane. The antiproliferative activity of sulforaphane-loaded ethosomes® was tested on SK-MEL 28 and improved anticancer activity was observed in comparison with the free drug

    Gray matter reduction in high-risk subjects, recently diagnosed and chronic patients with schizophrenia: A revised coordinate-based meta-analysis

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    INTRODUCTION: Characterizing neuroanatomical markers of different stages of schizophrenia (SZ) to assess of how the disorder develops is extremely important for the clinical practice. It still remains uncertain how abnormalities are formed as SZ progresses. OBJECTIVES: We reviewed and analyzed 113 voxel based morphometry studies on people at risk of or with schizophrenia to assess GM alterations at different stages of the disorder and to functionally characterize these GM variations. METHODS: We performed a meta-analysis of voxel-based morphometry studies of genetic and clinical high-risk subjects (g-/c-HR), recently diagnosed (RDSZ) and chronic SZ patients (ChSZ). We quantified gray matter (GM) changes associated with these four conditions and compared them with contrast and conjunctional data. We performed the behavioral analysis and networks decomposition of alterations to obtain their functional characterization. RESULTS: Compared to previous investigations, results reveal a robust cortical-subcortical, left-to-right homotopic progression of GM loss. The right anterior cingulate is the only altered region in all conditions. Contrast analyses show left-lateralized insular, amygdalar and parahippocampal GM reduction in RDSZ, which appears bilateral in ChSZ. An overlap between RDSZ and ChSZ is observed in the left insula, amygdala, precentral and inferior frontal gyri. Functional decomposition shows involvement of the salience network, with an enlargement of the sensorimotor network in RDSZ and the thalamus-basal nuclei network in ChSZ. [Figure: see text] CONCLUSIONS: These results can help the research on diagnostic and neuroimaging biomarkers of SZ staging, as well as on the identification of new therapeutics neuroanotomic targets that could be addressed with focused magnetic or non-invasive electric stimulation. DISCLOSURE: No significant relationships
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