762 research outputs found
An 'expert approach' to enhance GIS training: the case study of land-use suitability mapping
To enhance the learning and teaching of geographic information systems in higher-education Earth sciences, we present results from a research which identified the strategies and concepts that underlie the suitability-mapping process. The analysis of common practices in mapping and GIS environmental projects led our attention to a particular kind of mapping: GIS-bases land-use suitability mapping, with multi criteria spatial analysis method. This method has a professionalizing nature since it supports the debate on territorial choices that involve decision making. Indeed, from a pedagogical point of view, this method, allows a progressive and comprehensive approach to the use of GIS. Based on the expert-novice continuum approach, this study focuses on two dimensions: a cognitive dimension, which explores and compares the way of thinking of experienced and novice users when solving site location problems with GIS; and on an instructional dimension, which identifies and integrate the expert methods in the resolution strategies of learners
Effect of the electronic pressure on the energy and magnetic moment of charged test particles in turbulent electromagnetic fields
In this work we perform direct numerical simulations of three-dimensional
magnetohydrodynamics with a background magnetic field, representing solar wind
plasma, and introduce test particles to explore how a turbulent electromagnetic
environment affects them. Our focus is on the terms of the electric field
present in the generalized Omh's Law that are usually dismissed as unimportant.
These are the Hall and the electronic pressure (EP) terms, but we concentrate
primarily on the latter. We discover that the EP term generates an acceleration
of the particles, which represent protons, in the direction parallel to the
background magnetic field, in contrast to the known preferential perpendicular
energization. By studying the electric field itself, we are able to detect the
type of structures of the EP field that produce such parallel acceleration.
These are thin and elongated structures placed on top of a monotonic and
near-zero background. A statistical study to understand the real significance
of the electronic pressure term is also performed
Lorentz-Lorenz Coefficient, Critical Point Constants, and Coexistence Curve of 1,1-Difluoroethylene
We report measurements of the Lorentz-Lorenz coefficient density dependence,
the critical temperature, and the critical density, of the fluid
1,1-difluoroethylene. Lorentz-Lorenz coefficient data were obtained by
measuring refractive index and density of the same fluid sample independently
of one another. Accurate determination of the Lorentz-Lorenz coefficient is
necessary for transformation of refractive index data into density data from
optics-based experiments on critical phenomena of fluid systems done with
different apparatus, with which independent measurement of the refractive indes
and density is not possible. Measurements were made along the coexistence curve
of the fluid and span the density range 0.01 to 0.80 g/cc. The Lorentz-Lorenz
coefficient results show a stronger density dependence along the coexistence
curve than previously observed in other fluids, with a monotonic decrease from
a density of about 0.2 g/cc onwards, and an overall variation of about 2.5% in
the density range studied. No anomaly in the Lorentz-Lorenz coefficient was
observed near the critical density. The critical temperature is measured at
Tc=(302.964+-0.002) K (29.814 C) and the measured critical density is
(0.4195+-0.0018)g/cc.Comment: 14 pages, 6 figures, MikTeX 2.4, submitted to Physical Review
Hantaviruses in agricultural and forestry workers: Knowledge, attitudes and practices in Italian physicians
Hantaviruses are viral pathogens usually endemic in rodent populations. Human exposure follows inhalation of dusts contaminated with rodent excreta, and most individuals have been in-fected in occupational settings heavily contaminated with rodent droppings, such as agricultural and forestry. To date, knowledge, attitudes and practices of medical professionals, especially occupational physicians (OP), regarding hantavirus disease in at-risk workers have been scarcely investigated. We investigated these topics through a structured questionnaire administered through an online survey of 223 medical professionals (42.2% of them working as OP). Adequate general knowledge of hantavirus disease was found in 48.9% of respondents, with OP exhibiting a better understanding of clinical features of human hantavirus infections. OP aware of the endemic status of hantavirus in North-Eastern Italy exhibited higher risk perception for agricultural workers (odds ratio 21,193, 95% confidence interval 3.666–122.505). On the contrary, a better knowledge of hantaviruses was association with acknowledging an increased risk of hantavirus infection in forestry workers (odds ratio 5.880, 95% confidence interval 1.620–21.343). Hantavirus in Italy represent an often-overlooked biological risk in occupational settings. The lack of preventive immunization, the inappropriate risk perception and the unsatisfying awareness of hantavirus issues collectively stress the importance of appropriate information campaigns among health care providers
Nimesulide in painful OA of the knee
Summary Objective:  This study was designed to investigate the analgesic effects of nimesulide and celecoxib in patients with knee osteoarthritis (OA). In patients with joint effusion, the effects of these non-steroidal anti-inflammatory drugs (NSAIDs) on synovial fluid concentrations of substance P (SP), interleukin (IL)-6 and IL-8 also were evaluated. Methods:  Patients were randomly assigned either nimesulide (100 mg twice a day) or celecoxib (200 mg once a day) for 2 weeks. The intensity of joint pain was assessed with a 100-mm visual analogue scale (VAS). Furthermore, patients completed questions about analgesic efficacy and overall tolerability of the treatments on a five-point categorial scale. Synovial fluid samples were drawn at baseline, 30 min after the first drug intake (day 1), and 30 min after the last drug intake (day 14). Results:  We enrolled 44 patients, 20 of whom had a joint effusion. In this group, the effects of nimesulide were more marked than for celecoxib, with evidence of a faster onset of the analgesic action. Both after a single or repeated administration, nimesulide significantly reduced the synovial fluid concentrations of SP and IL-6. Celecoxib, on the other hand, did not change the concentrations of SP and significantly reduced the levels of IL-6 only on day 14. None of the drugs affected IL-8. Both drugs were generally well tolerated. Conclusions:  These results provide evidence that nimesulide is an effective agent for the symptomatic treatment of OA. The effect on inflammatory pain mediators is consistent with the fast analgesic action of this NSAID
High-level detection of gene amplification and chromosome aneuploidy in extracted nuclei from paraffin-embedded tissue of human cancer using FISH: a new approach for retrospective studies
A novel application of fluorescence in situ hybridization (FISH) to isolated nuclei is described. The method detects gene amplification and chromosome aneuploidy in extracted nuclei from paraffin-embedded tissue of human cancer with greater sensitivity and specificity than existing FISH methods. In this study, the method is applied to signal detection of the HER-2/neu (c-erbB-2) gene, whose amplification is one of the most common genetic alterations associated with human breast cancer. Nuclei were extracted and isolated from formalin fixed, paraffin embedded tissue of 43 different carcinomas (breast, ovary, endometrium, gastrointestinal stromal tumor and malignant mesothelioma). FISH was performed both on sections and extracted nuclei of each tissue using chromosome enumeration probes (CEP) for the centromeric regions of chromosomes 8 and 17, and a locus specific identifier (LSI) for the HER-2/neu oncogene. Differences between ploidy calculated in sections and extracted nuclei were seen in 3 breast carcinomas and 1 gastrointestinal stromal tumor (GIST). Furthermore, 1 breast cancer, previously considered to be borderline for HER-2/neu gene amplification turned out to be clearly amplified. Nuclei extraction and isolation bypass all the problems related to signal interpretation in tissue sections, and the adoption of this new technique, which improves the signal quality in several neoplastic samples, is suggested
Application of alternative fixatives to formalin in diagnostic pathology
Fixation is a critical step in the preparation of tissues for histopathology. The aim of this study was to investigate the effects of different fixatives vs formalin on proteins and DNA, and to evaluate alternative fixation for morphological diagnosis and nucleic acid preservation for molecular methods. Forty tissues were fixed for 24 h with six different fixatives: the gold standard fixative formalin, the historical fixatives Bouin and Hollande, and the alternative fixatives Greenfix, UPM and CyMol. Tissues were stained (Haematoxylin-Eosin, Periodic Acid Schiff, Trichromic, Alcian-blue, High Iron Diamine stainings), and their antigenicity was determined by immunohistochemistry (performed with PAN-CK, CD31, Ki-67, S100, CD68, AML antibodies). DNA extraction, KRAS sequencing, FISH for CEP-17, and flow cytometry analysis of nuclear DNA content were applied. For cell morphology the alternative fixatives (Greenfix, UPM, CyMol) were equivalent to formalin. As expected, Hollande proved to be the best fixative for morphology. The morphology obtained with Bouin was comparable to the one with formalin. Hollande was the best fixative for histochemistry. Bouin proved to be equivalent to formalin. The alternative fixatives were equivalent to formalin, although with greater variability in haematoxylin-eosin staining. It proved the possibility to obtain immunohistochemical staining largely equivalent to that following formalin-fixation with the following fixatives: Greenfix, Hollande, UPM and CyMol. The tissues fixed in Bouin did not provide results comparable to those obtained with formalin. The DNA extracted from samples fixed with alternative fixatives was found to be suitable for molecular analysis
A new type of Hypersensitivity Pneumonitis: salami brusher’s disease
We observed five consecutive cases of Hypersensitivity Pneumonitis in subjects working in a salami factory. The workers had to clean the white mould growing on salami surface using a manual wire brush. The five patients (four female) had a mean age of 39±15 years; two were smokers. Three patients had an acute clinical presentation with fever, dyspnoea, dry cough, oxygen desaturation, and presented at the emergency department with suspected diagnosis of community acquired pneumonia. The mean latency for developing respiratory symptoms was 11.6 days. Pulmonary function test demonstrated a reduction in diffusing capacity (DLCO) in all 5 patients (60±15% of predicted value). Skin prick test was positive for Penicillium spp in 3 cases and for Cladosporium and Aspergillus spp in 2 others. Specific IgG antibodies against Penicillium spp were positive in 3 subjects; 2 were positive for Aspergillus Fumigatus. The prevailing radiological pattern was a ground glass appearance in the three patients with acute clinical onset and a centrilobular one in patients with subacute onset. All patients were advised to avoid exposure to the antigens. Follow-up visits including pulmonary function testing, and DLCO measurement were conducted at one, three and six months. HRCT was performed at six month. Four subjects had a complete radiological and clinical resolution after changing work. Only one patient was treated with oral steroids for severe dyspnoea and progressive reduction of DLCO, gaining a complete radiological and clinical stability at six months
Sinonasal mucosal melanoma: Molecular profile and therapeutic implications from a series of 32 cases
BACKGROUND:
Primary sinonasal mucosal melanomas are aggressive tumors with a poor clinical control by current treatments, raising the urgent need of novel strategies.
METHODS:
By fluorescence in situ hybridization (FISH), direct sequencing, and immunohistochemistry, we investigate the spectrum of molecular abnormalities in a cohort of 32 cases of primary sinonasal mucosal melanomas.
RESULTS:
We found that all primary sinonasal mucosal melanomas lack BRAF V600E mutation; in addition, they are characterized by somatic mutations of NRAS (22%) and KIT (12.5%), together with amplification of RREB1 (100%) and loss of MYB (76%). The large majority of cases showed KIT protein expression (96.9%). Among tumor suppressor genes, primary sinonasal mucosal melanomas showed loss of PTEN (48.1%) and p16/INK4a (55.2%). All tested cases showed expression of pAkt and pErk, suggesting a combined activation of PI3K/Akt and RAS-mitogen-activated protein kinase (MAPK) pathways.
CONCLUSIONS:
This molecular fingerprint strongly argues against the clinical efficacy of BRAF-inhibitors, but could candidate primary sinonasal mucosal melanomas to therapeutic strategies targeting RAS and KIT mutations or inhibiting PI3K-Akt-mTOR pathway
Antiproliferative activity, mechanism of action and oral antitumor activity of CP-4126, a fatty acid derivative of gemcitabine, in in vitro and in vivo tumor models
Gemcitabine is a deoxycytidine (dCyd) analog with activity in leukemia and solid tumors, which requires phosphorylation by deoxycytidine kinase (dCK). Decreased membrane transport is a mechanism of resistance to gemcitabine. In order to facilitate gemcitabine uptake and prolong retention in the cell, a lipophilic pro-drug was synthesized (CP-4126), with an elaidic fatty acid esterified at the 5'position. CP-4126 was tested in cell lines resistant to cytarabine, another dCyd analog or gemcitabine. Activity of gemcitabine and the derivative was comparable in the parent cell lines, while in dCK deficient cells all compounds were inactive. However, inhibition of nucleoside transport increased the IC(50) for gemcitabine up to 200-fold, but not for CP-4126, underlining the independence of a nucleoside transporter. For in vivo evaluation, nude mice bearing a human xenograft were treated intraperitoneally every third day for five doses at the maximal tolerated dose. In melanoma, sarcoma, lung, prostate, pancreatic and breast cancer xenografts, gemcitabine and CP-4126 were equally and highly effective; in four other xenografts moderately but equally active. In contrast to gemcitabine, CP-4126 could be administered orally, with a schedule and dose dependent toxicity and antitumor activity. In a colon cancer xenograft, antitumor activity of orally administered CP-4126 was equal to the intraperitoneally administered drug. In conclusion, CP-4126 is membrane transporter independent. Intraperitoneally administered CP-4126 was as effective as gemcitabine in several xenografts and CP-4126 is tolerated when orally administered. CP-4126 seems to be a promising new anticancer drug
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