Direct Dark Matter searches are nowadays one of the most fervid research topics with many experimental efforts devoted to the search for nuclear recoils induced by the scattering of Weakly ...Interactive Massive Particles (WIMPs). Detectors able to reconstruct the direction of the nucleus recoiling against the scattering WIMP are opening a new frontier to possibly extend Dark Matter searches beyond the neutrino background. Exploiting directionality would also prove the galactic origin of Dark Matter with an unambiguous signal-to-background separation. Indeed, the angular distribution of recoiled nuclei is centered around the direction of the Cygnus constellation, while the background distribution is expected to be isotropic. Current directional experiments are based on gas TPC whose sensitivity is limited by the small achievable detector mass. In this paper we present the discovery potential of a directional experiment based on the use of a solid target made of newly developed nuclear emulsions and of optical read-out systems reaching unprecedented nanometric resolution.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This work investigates the physicochemical alterations of water perturbed by prolonged contact with the hydrophilic polymer Nafion, referred to as iteratively nafionized water (INW). The parameters ...measured are: electrical conductivity,
χ
μS cm
−1
, heat of mixing with basic sodium hydroxide (NaOH) solutions, Δ
Q
NaOH
mix
J kg
−1
, and pH. The results indicate that supramolecular aggregates of water molecules form after prolonged contact with a Nafion surface. Analytical determination by ion chromatography allows us to exclude the role of contaminants. This suggests that water may possess an exceptional self-organization capability triggered by the contact with a hydrophilic surface. Conductometric, pH-metric, and calorimetric titrations of INW were performed by the addition of NaOH solutions to determine the concentration of the aqueous nanostructures, via conductometric and pH-metric titration with NaOH solutions. Thermodynamic parameters were determined via calorimetric titration, for the process of formation of complexes between the nanostructures and the base used.
We examine the sensitivity of a large scale two-phase liquid argon detector to the directionality of the dark matter signal. This study was performed under the assumption that, above 50 keV of recoil ...energy, one can determine (with some resolution) the direction of the recoil nucleus without head-tail discrimination, as suggested by past studies that proposed to exploit the dependence of columnar recombination on the angle between the recoil nucleus direction and the electric field. In this paper we study the differential interaction recoil rate as a function of the recoil direction angle with respect to the zenith for a detector located at the Laboratori Nazionali del Gran Sasso and we determine its diurnal and seasonal modulation. Using a likelihood-ratio based approach we show that, with the angular information alone, 100 (250) events are enough to reject the isotropic hypothesis at three standard deviation level, for a perfect (400 mrad) angular resolution. For an exposure of 100 tonne years this would correspond to a spin independent WIMP-nucleon cross section of about 10−46cm2 at 200 GeV WIMP mass. The results presented in this paper provide strong motivation for the experimental determination of directional recoil effects in two-phase liquid argon detectors.
Human papillomavirus (HPV) bivalent and quadrivalent vaccines have been widely implemented in worldwide organized immunization programs. A nonavalent HPV vaccine is now available in several ...countries. The objective was to describe the fraction of squamous non-invasive high-grade cervical intraepithelial lesions attributable to genotypes targeted by bi-quadrivalent vaccines and by nonavalent vaccine according to age and diagnosis in women living in the city of Vigo (Galicia, Spain).
Cervical scrapings (2009-2014) of women with histological diagnosis of cervical intraepithelial neoplasia grade 2 (CIN2, n = 145) and grade 3-carcinoma in situ (CIN3-CIS, n = 244) were tested with Linear Array HPV Genotyping test (Roche diagnostics, Mannheim, Germany). Hierarchical estimation of the fraction attributable to HPV 16/18 or HPV 31/33/45/52/58 detected alone or in combination was calculated. Absolute additional fraction attributable to genotypes targeted by nonavalent vaccine compared to genotypes targeted by bi-quadrivalent vaccines was calculated as the increment of attributable cases with respect to all studied cases. Age group 1, 2 and 3 included women 18 to 34, 35-44 and ≥45 years old, respectively. EPIDAT 3.1 was used.
Fraction attributable to genotypes targeted by bi-quadrivalent vaccines was 59% CIN2 vs. 69% CIN3-CIS (p < 0.001). It was 63/51/50% of CIN2 and 78/66/45% of CIN3-CIS in age group 1, 2, 3, respectively. Fraction attributable to genotypes targeted by nonavalent vaccine was 86% CIN2 and 86% CIN3-CIS. It was 87/91/75% of CIN2 and 90/86/76% of CIN3-CIS in age group 1, 2, 3, respectively. Fraction attributable to genotypes targeted by these vaccines tended to decrease as age increased (p-trend <0.05). Globally, absolute additional attributable fraction was 16%, 26% and 29% in age group 1, 2 and 3, respectively (p < 0.005).
Absolute additional fraction of CIN2 and CIN3-CIS attributable to genotypes targeted by nonavalent vaccine was observed in women of any age, especially in those over 35 years old.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Initially known as the reproductive hormone, relaxin was shown to possess other therapeutically useful properties that include extracellular matrix remodeling, anti-inflammatory, anti-ischemic and ...angiogenic effects. All these findings make relaxin a potential drug for diverse medical applications. Its precursor, pro-relaxin, is an 18 kDa protein, that shows activity in in vitro assays. Since extraction of relaxin from animal tissues raises several issues, prokaryotes and eukaryotes were both used as expression systems for recombinant relaxin production. Most productive results were obtained when using Escherichia coli as a host for human relaxin expression. However, in such host, relaxin precipitated in the form of inclusion bodies and, therefore, required several expensive recovery steps as cell lysis, refolding and reduction.
To overcome the issues related to prokaryotic expression here we report the production and purification of secreted human pro-relaxin H2 by using the methylotrophic yeast Pichia pastoris as expression host. The methanol inducible promoter AOX1 was used to drive expression of the native and histidine tagged forms of pro-relaxin H2 in dual phase fed-batch experiments on the 22 L scale. Both protein forms presented the correct structure, as determined by mass spectrometry and western blotting analyses, and demonstrated to be biologically active in immune enzymatic assays. The presence of the tag allowed to simplify pro-relaxin purification obtaining higher purity.
This work presents a strategy for microbial production of recombinant human pro-relaxin H2 in Pichia pastoris that allowed the obtainment of biologically active pro-hormone, with a final concentration in the fermentation broth ranging between 10 and 14 mg/L of product, as determined by densitometric analyses.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Study of gas purifiers for the CMS RPC detector Benussi, L.; Bianco, S.; Colafranceschi, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2012, Letnik:
661
Journal Article
Recenzirano
Odprti dostop
The CMS RPC muon detector utilizes a gas recirculation system called closed loop (CL) to cope with large gas mixture volumes and costs. A systematic study of CL gas purifiers has been carried out ...over 400 days between July 2008 and August 2009 at CERN in a low-radiation test area, with the use of RPC chambers with currents monitoring, and gas analysis sampling points. The study aimed to fully clarify the presence of pollutants, the chemistry of purifiers used in the CL, and the regeneration procedure. Preliminary results on contaminants release and purifier characterization are reported.
The CMS experiment is expected to start data taking during 2008, and large data samples, of the peta-bytes scale, will be produced each year. The CMS Physics Tools package provides the CMS physicist ...with a powerful and flexible software layer for analysis of these huge datasets that is well integrated in the CMS experiment software. C++ generic programming is used to allow simple extensions of analysis tools. A core part of this package is the Candidate Model providing a coherent interface to different types of data. Standard tasks such as combinatorial analyses, generic cuts, MC truth matching and constrained fitting are supported. Advanced template techniques enable the user to add missing features easily. We explain the underlying model, certain details of the implementation and present some use cases showing how the tools are currently used in generator and full simulation studies as preparation for analysis of real data.
Background: The urokinase plasminogen activator receptor (u‐PAR) focuses the proteolytic activity of the urokinase plasminogen activator (u‐PA) on the endothelial cell surface, thus promoting ...angiogenesis in a protease‐dependent manner. The u‐PAR may exist in a glycophosphatidylinositol‐anchored and in a soluble form (soluble u‐PAR Su‐PAR), both including the chemotactic Ser88‐Arg‐Ser‐Arg‐Tyr92 internal sequence. Objective: To investigate whether Su‐PAR may trigger endothelial cell signaling leading to new vessel formation through its chemotactic Ser88‐Arg‐Ser‐Arg‐Tyr92 sequence. Methods and Results: In this study, the formation of vascular‐like structures by human umbilical vein endothelial cells was assessed by using a matrigel basement membrane preparation. First, we found that Su‐PAR protein promotes the formation of cord‐like structures, and that this ability is retained by the isolated Ser88‐Arg‐Ser‐Arg‐Tyr92 chemotactic sequence, the maximal effect being reached at 10 nmol L−1 SRSRY peptide (SRSRY). This effect is mediated by the αvβ3 vitronectin receptor, is independent of u‐PA proteolytic activity, and involves the internalization of the G‐protein‐coupled formyl‐peptide receptor in endothelial cells. Furthermore, exposure of human saphenous vein rings to Su‐PAR or SRSRY leads to a remarkable degree of sprouting. Finally, we show that Su‐PAR and SRSRY promote a marked response in angioreactors implanted into the dorsal flank of nude mice, retaining 91% and 66%, respectively, of the angiogenic response generated by a mixture of vascular endothelial growth factor and fibroblast growth factor type 2. Conclusions: Our results show a new protease‐independent activity of Su‐PAR that stimulates in vivo angiogenesis through its Ser88‐Arg‐Ser‐Arg‐Tyr92 chemotactic sequence.
In 2012, 14 Italian institutions participating in LHC Experiments won a grant from the Italian Ministry of Research (MIUR), with the aim of optimising analysis activities, and in general the Tier2 ...Tier3 infrastructure. We report on the activities being researched upon, on the considerable improvement in the ease of access to resources by physicists, also those with no specific computing interests. We focused on items like distributed storage federations, access to batch-like facilities, provisioning of user interfaces on demand and cloud systems. R&D on next-generation databases, distributed analysis interfaces, and new computing architectures was also carried on. The project, ending in the first months of 2016, will produce a white paper with recommendations on best practices for data-analysis support by computing centers.
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