2,404 research outputs found
Charged particle's flux measurement from PMMA irradiated by 80 MeV/u carbon ion beam
Hadrontherapy is an emerging technique in cancer therapy that uses beams of
charged particles. To meet the improved capability of hadrontherapy in matching
the dose release with the cancer position, new dose monitoring techniques need
to be developed and introduced into clinical use. The measurement of the fluxes
of the secondary particles produced by the hadron beam is of fundamental
importance in the design of any dose monitoring device and is eagerly needed to
tune Monte Carlo simulations. We report the measurements done with charged
secondary particles produced from the interaction of a 80 MeV/u fully stripped
carbon ion beam at the INFN Laboratori Nazionali del Sud, Catania, with a
Poly-methyl methacrylate target. Charged secondary particles, produced at
90 with respect to the beam axis, have been tracked with a drift
chamber, while their energy and time of flight has been measured by means of a
LYSO scintillator. Secondary protons have been identified exploiting the energy
and time of flight information, and their emission region has been
reconstructed backtracking from the drift chamber to the target. Moreover a
position scan of the target indicates that the reconstructed emission region
follows the movement of the expected Bragg peak position. Exploting the
reconstruction of the emission region, an accuracy on the Bragg peak
determination in the submillimeter range has been obtained. The measured
differential production rate for protons produced with 83 MeV and emitted at 90 with respect to the beam line is: .Comment: 13 pages, 9 figure
Monitoring of Urban Growth and its Related Environmental Impacts: Niamey Case Study (Niger)
AbstractThe present contribution is about a preliminary study of the evolution of Niamey city (Niger) during last decades.Recent advances in remote sensing, both in satellite hardware technology and image availability development, provide opportunities image collection and multitemporal analysis on urban form and size that can be useful for policy and planning. Some opportunities for, and limitations on, monitoring urban growth using remote sensing data are shown in the present contribution; moreover examples of environmental impacts of urban growth, as monitored with remote sensing, are provided in order to define future development of dumps and quarries and its environmental impacts on Niamey city
Measurement of the neutron detection efficiency of a 80% absorber - 20% scintillating fibers calorimeter
The neutron detection efficiency of a sampling calorimeter made of 1 mm
diameter scintillating fibers embedded in a lead/bismuth structure has been
measured at the neutron beam of the The Svedberg Laboratory at Uppsala. A
significant enhancement of the detection efficiency with respect to a bulk
organic scintillator detector with the same thickness is observed.Comment: 10 pages, 7 figure
Impure Aspects of Supersymmetric Wilson Loops
We study a general class of supersymmetric Wilson loops operator in N = 4
super Yang-Mills theory, obtained as orbits of conformal transformations. These
loops are the natural generalization of the familiar circular Wilson-Maldacena
operator and their supersymmetric properties are encoded into a Killing spinor
that is not pure. We present a systematic analysis of their scalar couplings
and of the preserved supercharges, modulo the action of the global symmetry
group, both in the compact and in the non-compact case. The quantum behavior of
their expectation value is also addressed, in the simplest case of the
Lissajous contours: explicit computations at weak-coupling, through Feynman
diagrams expansion, and at strong-coupling, by means of AdS/CFT correspondence,
suggest the possibility of an exact evaluation.Comment: 40 pages, 4 figure
A real-time RT-PCR assay for molecular identification and quantitation of feline morbillivirus RNA from biological specimens.
The aim of this study was to develop a real-time RT-PCR to detect and quantitate feline
morbillivirus (FeMV) RNA in biological samples. Primers and probe were targeted on a conserved
region of FeMV P/V/C gene. To validate the assay with field samples, a total number of specimens
of cats have been recruited including 264 urine and blood samples and compared with a generic
RT-PCR targeting the L protein encoding gene of morbilliviruses. In addition, 385 tissue samples
from 35 carcasses of cats have been also employed. RNA titres were low in all tested samples.
Results also indicated the absence of cross-reaction with related morbilliviruses and existing
pathogens of cats. However, in tissues with low levels of FeMV RNA, the presence of viral antigen
was confirmed by immunohistochemistry targeting the N viral protein. This newly described assay
allows for a rapid, accurate and reliable quantitative detection of FeMV RNA that can be applied
for diagnostics and research studies
Psychostimulant effect of the synthetic cannabinoid JWH-018 and AKB48: Behavioral, neurochemical, and dopamine transporter scan imaging studies in mice
JWH-018 and AKB48 are two synthetic cannabinoids (SCBs) belonging to different structural classes and illegally marketed as incense, herbal preparations, or chemical supply for theirs psychoactive cannabis-like effects. Clinical reports from emergency room reported psychomotor agitation as one of the most frequent effects in people assuming SCBs. This study aimed to investigate the psychostimulant properties of JWH-018 and AKB48 in male CD-1 mice and to compare their behavioral and biochemical effects with those caused by cocaine and amphetamine. In vivo studies showed that JWH-018 and AKB48, as cocaine and amphetamine, facilitated spontaneous locomotion in mice. These effects were prevented by CB1 receptor blockade and dopamine (DA) D1/5 and D2/3 receptors inhibition. SPECT-CT studies on dopamine transporter (DAT) revealed that, as cocaine and amphetamine, JWH-018 and AKB48 decreased the [123I]-FP-CIT binding in the mouse striatum. Conversely, in vitro competition binding studies revealed that, unlike cocaine and amphetamine, JWH-018 and AKB48 did not bind to mouse or human DAT. Moreover, microdialysis studies showed that the systemic administration of JWH-018, AKB48, cocaine, and amphetamine stimulated DA release in the nucleus accumbens (NAc) shell of freely moving mice. Finally, unlike amphetamine and cocaine, JWH-018 and AKB48 did not induce any changes on spontaneous [3H]-DA efflux from murine striatal synaptosomes. The present results suggest that SCBs facilitate striatal DA release possibly with different mechanisms than cocaine and amphetamine. Furthermore, they demonstrate, for the first time, that JWH-018 and AKB48 induce a psychostimulant effect in mice possibly by increasing NAc DA release. These data, according to clinical reports, outline the potential psychostimulant action of SCBs highlighting their possible danger to human health
Prevalence and Predictors of Out-of-Target LDL Cholesterol 1 to 3 Years After Myocardial Infarction. A Subanalysis From the EYESHOT Post-MI Registry
Background: There is an incomplete understanding of the prevalence and predictors of attainment of low-density lipoprotein cholesterol (LDL-C) goal after myocardial infarction (MI). Aim: To evaluate the prevalence of achievement of LDL-C goal of 70 mg/dL, to identify the baseline features associated with suboptimal lipid control, and to assess the use of LDL-C-lowering drug therapies (LLT) beyond the first year after MI. Methods: The EYESHOT Post-MI was a prospective, cross-sectional, Italian registry, which enrolled patients presenting to cardiologist 1 to 3 years after MI. In this retrospective post-hoc analysis, patients were categorized in 2 groups according to the achievement or not of the LDL-C goal of 70 mg/dL. Univariable and multivariable logistic regression analyses were performed to identify the baseline features associate with LDL-C >= 70 mg/dL. Results: The study population included 903 patients (mean age 65.5 +/- 11.5 years). Among them, LDL-C was >= 70 mg/dL in 474 (52.5%). Male sex (p = 0.031), hypertension (p = 0.024), prior percutaneous coronary intervention (p = 0.016) and high education level (p = 0.008) were higher in the LDL-C < 70 group. At multivariable analysis, low education level was an independent predictor of LDL-C >= 70 mg/dL (OR:1.582; 95%CI, 1.156-2.165; p = 0.004). Conversely, hypertension increased the probability to achieve the LDL-C goal (OR:0.650; 95%CI, 0.443-0.954; p = 0.028). Among off-target patients, LLT was not modified in the majority of cases (67.3%), intensified in 85 (18.6%), and actually reduced in 63 patients (13.8%). Conclusions: In patients presenting to cardiologists 1 to 3 years from the last MI event, LDL-C is not under control in a large proportion of patients, particularly in those with a low education level or without hypertension. LLT is underused in this very-high-risk setting
The N-glycan structures of the antigenic variants of chlorovirus PBCV-1 major capsid protein help to identify the virus-encoded glycosyltransferases
The chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) is a large dsDNA virus that infects the microalga Chlorella variabilis NC64A. Unlike most other viruses, PBCV-1 encodes most, if not all, of the machinery required to glycosylate its major capsid protein (MCP). The structures of the four N-linked glycans from the PBCV-1 MCP consist of nonasaccharides, and similar glycans are not found elsewhere in the three domains of life. Here, we identified the roles of three virus-encoded glycosyltransferases (GTs) that have four distinct GT activities in glycan synthesis. Two of the three GTs were previously annotated as GTs but the third GT was identified in this study. We determined the GT functions by comparing the wild-type glycan structures from PBCV-1 with those from a set of PBCV-1 spontaneous GT genes mutants resulting in antigenic variants having truncated glycan structures. According to our working model, the virus gene a064r encodes a GT with three domains: domain 1 has a β-L-rhamnosyltransferase activity, domain 2 has an α -L-rhamnosyltransferase activity and domain 3 is a methyltransferase that decorates two positions in the terminal α -L-rhamnose (Rha) unit. The a075l gene encodes a β -xylosyltransferase that attaches the distal D-xylose (Xyl) unit to the L-fucose (Fuc) that is part of the conserved N-glycan core region. Lastly, gene a071r encodes a GT that is involved in the attachment of a semiconserved element, α-D-Rha, to the same L-Fuc in the core region. Our results uncover GT activities that assemble four of the nine residues of the PBCV-1 MCP N-glycans.
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