Status of the NEXT experiment Simón, A.
Journal of physics. Conference series,
11/2022, Letnik:
2374, Številka:
1
Journal Article
Recenzirano
Odprti dostop
NEXT is an international experimental program aiming at the detection of 0
ββ
decay in
136
Xe using a high-pressure gaseous xenon electroluminescent TPC. The technique allows for superb energy ...resolution, 1% FWHM at Q
ββ
, and topological discrimination based on the unique signature that a double electron produces in a gaseous medium. With ∼0.5 m in each dimension, NEXT-White (NEW) has been operating underground since 2016 at the Laboratorio Subterráneo de Canfranc (LSC), using xenon enriched to 90%
136
Xe. Its purpose is to validate all aspects of the technology on a large scale and demonstrate its performance on 2
ββ
decay events. NEXT-100 will replace NEW and construction will start during 2021. It will deploy ∼97 kg of enriched xenon and demonstrate sensitivity to 0
ββ
decay half-lives on the scale of 10
25
yr.
The goal of the NEXT experiment is the observation of the neutrinoless double beta decay in 136Xe using a gaseous xenon TPC with electroluminescent amplification and specialized photodetector arrays ...for calorimetry and tracking. After a prototyping period (2009-2014) where the technique was demonstrated, the Collaboration has completed the construction and started the operation of its first phase (NEXT-White or NEW) in the Laboratorio Subterraneo de Canfranc, in the Spanish Pyrenees, with the objectives of measuring in-situ the NEXT background model and the two-neutrino mode of the double beta decay under a radiopure regime. After running NEW, the Collaboration will operate a bigger detector, NEXT-100, which will look for the neutrinoless decay mode.
The Iberian lynx (Lynx pardinus) is considered the most endangered felid species in the world. In order to save this species, the Spanish authorities implemented a captive breeding program recruiting ...lynxes from the wild. In this context, a retrospective survey on prevalence of selected feline pathogens in free-ranging lynxes was initiated.
We systematically analyzed the prevalence and importance of seven viral, one protozoan (Cytauxzoon felis), and several bacterial (e.g., hemotropic mycoplasma) infections in 77 of approximately 200 remaining free-ranging Iberian lynxes of the Doñana and Sierra Morena areas, in Southern Spain, between 2003 and 2007. With the exception of feline immunodeficiency virus (FIV), evidence of infection by all tested feline pathogens was found in Iberian lynxes. Fourteen lynxes were feline leukemia virus (FeLV) provirus-positive; eleven of these were antigenemic (FeLV p27 positive). All 14 animals tested negative for other viral infections. During a six-month period in 2007, six of the provirus-positive antigenemic lynxes died. Infection with FeLV but not with other infectious agents was associated with mortality (p<0.001). Sequencing of the FeLV surface glycoprotein gene revealed a common origin for ten of the eleven samples. The ten sequences were closely related to FeLV-A/61E, originally isolated from cats in the USA. Endogenous FeLV sequences were not detected.
It was concluded that the FeLV infection most likely originated from domestic cats invading the lynx's habitats. Data available regarding the time frame, co-infections, and outcome of FeLV-infections suggest that, in contrast to the domestic cat, the FeLV strain affecting the lynxes in 2007 is highly virulent to this species. Our data argue strongly for vaccination of lynxes and domestic cats in and around lynx's habitats in order to prevent further spread of the virus as well as reduction the domestic cat population if the lynx population is to be maintained.
The expansion of the COVID‐19 pandemic has been accompanied by numerous reports of chilblain‐like lesions (CLL) in different countries; however, the pathogenesis of these lesions is still unclear. ...This systematic review and meta‐analysis aimed to assess the prevalence of COVID‐19 (diagnosed using PCR and/or serology) in patients with CLL. We undertook a literature search in PubMed, Embase, and Scopus (to 15 March 2021), including studies that reported on the number of patients with CLL with positive PCR and/or serology for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) or with a clinical suspicion of COVID‐19. Regardless of data heterogeneity, a random‐effects model was used to pool prevalence estimates. The meta‐analysis included 63 original studies, involving 2919 cases of CLL. A subgroup of these patients underwent diagnostic tests for COVID‐19 (PCR: n = 1154, 39.5%; serology: n = 943, 32.3%). The pooled prevalence of COVID‐19 in the overall sample and in the subgroup who were tested for COVID‐19 was, respectively: (i) positive PCR: 2.6% 95% confidence interval (CI) 1.9% to 3.4% and 5.5% (95% CI, 3.7–7.7%); (ii) positive serology for SARS‐CoV‐2: 7.2% (95% CI, 4.7–10.2%) and 11.8% (95% CI, 7.9–16.3%); and (iii) positive PCR and/or serology, 15.2% (95% CI, 10.4–20.7%) and 7.5% (95% CI, 5.1–10.3%). Altogether, a small proportion of diagnostic tests for SARS‐CoV‐2, both PCR and serologies, show positive results in patients with CLL.
Mesenchymal stem cells are multilineage non-hematopoietic progenitor cells that play a key role in supporting the lymphohematopoietic system. Their distribution in bone marrow and secondary lymphoid ...organs allows an intimate interaction with T- and B-lymphocytes. While their effect on T-lymphocytes has been extensively analyzed, data on the effect of mesenchymal stem cells on B cells are more limited. We analyzed the effects of mesenchymal stem cells on B-lymphocytes and the pathways involved in these effects.
The effect of MSC on the proliferation and viability of B cells was evaluated using MTT assays, annexin/7-amino-actinomycin D and propidium iodide staining. The B-cell maturation pattern was established using flow cytometry based on the expression of different markers related to the differentiation of B cells, such as CD38, CD138, CD19 and CCR7, and to the expression of surface and intracellular immunoglobulins. Finally, western blot assays were used to identify the pathways involved in the effects of mesenchymal stem cells on B-lymphocytes.
Mesenchymal stem cells increased viability and blocked the cell cycle of B-lymphocytes in the G(0)/G(1) phase. In vitro exposure of B cells to plasmacytoid dendritic cells induced B-cell differentiation as shown by an increased number of CD38(++)/CD138(++) cells, which also displayed higher levels of cytoplasmic immunoglobulin and lower levels of CD19, CCR7 and surface immunoglobulin. Interestingly, this maturation pattern was inhibited by adding mesenchymal stem cells to the culture. Finally, mesenchymal stem cells modified the phosphorylation pattern of the extracellular response kinase 1/2 and p38 pathways which are both involved in B-cell viability, proliferation and activation.
Mesenchymal stem cells increase B-cell viability while inhibiting proliferation, arresting B-lymphocytes in the G(0)/G(1) phase of the cell cycle. The presence of mesenchymal stem cells blocked B-cell differentiation as assessed by flow cytometry. Finally, mesenchymal stem cells modified the activation pattern of the extracellular response kinase and the p38 mitogen-activated protein kinase pathways in B-lymphocytes.
Several studies have described a potential anti-tumour effect of cannabinoids (CNB). CNB receptor 2 (CB2) is mostly present in hematopoietic stem cells (HSC). The present study evaluates the ...anti-leukaemic effect of CNB.
Cell lines and primary cells from acute myeloid leukaemia (AML) patients were used and the effect of the CNB derivative WIN-55 was evaluated in vitro, ex vivo and in vivo.
We demonstrate a potent antileukemic effect of WIN-55 which is abolished with CB antagonists. WIN-treated mice, xenografted with AML cells, had better survival as compared to vehicle or cytarabine. DNA damage-related genes were affected upon exposure to WIN. Co-incubation with the PARP inhibitor Olaparib prevented WIN-induced cell death, suggesting PARP-mediated apoptosis which was further confirmed with the translocation of AIF to the nucleus observed in WIN-treated cells. Nicotinamide prevented WIN-related apoptosis, indicating NAD+ depletion. Finally, WIN altered glycolytic enzymes levels as well as the activity of G6PDH. These effects are reversed through PARP1 inhibition.
WIN-55 exerts an antileukemic effect through Parthanatos, leading to translocation of AIF to the nucleus and depletion of NAD+, which are reversed through PARP1 inhibition. It also induces metabolic disruptions. These effects are not observed in normal HSC.
Biomedical imaging is a driver of scientific discovery and a core component of medical care and is being stimulated by the field of deep learning. While semantic segmentation algorithms enable image ...analysis and quantification in many applications, the design of respective specialized solutions is non-trivial and highly dependent on dataset properties and hardware conditions. We developed nnU-Net, a deep learning-based segmentation method that automatically configures itself, including preprocessing, network architecture, training and post-processing for any new task. The key design choices in this process are modeled as a set of fixed parameters, interdependent rules and empirical decisions. Without manual intervention, nnU-Net surpasses most existing approaches, including highly specialized solutions on 23 public datasets used in international biomedical segmentation competitions. We make nnU-Net publicly available as an out-of-the-box tool, rendering state-of-the-art segmentation accessible to a broad audience by requiring neither expert knowledge nor computing resources beyond standard network training.
A
bstract
The
Neutrino Experiment with a Xenon TPC
(NEXT) searches for the neutrinoless double-beta (0
νββ
) decay of
136
Xe using high-pressure xenon gas TPCs with electroluminescent amplification. ...A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0
νββ
decay better than 10
27
years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.
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