A Nexafs Study of Nitric Oxide Layers Adsorbed from a nitrite Solution onto a Pt(111) Surface

NO molecules adsorbed on a Pt(111) surface from dipping in an acidic nitrite solution are studied by near edge X-ray absorption fine structure spectroscopy (NEXAFS), X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and scanning tunnelling microscopy (STM) techniques. LEED patterns and STM images show that no long range ordered structures are formed after NO adsorption on a Pt(111) surface. Although the total NO coverage is very low, spectroscopic features in N K-edge and O K-edge absorption spectra have been singled out and related to the different species induced by this preparation method. From these measurements it is concluded that the NO molecule is adsorbed trough the N atom in an upright conformation. The maximum saturation coverage is about 0.3 monolayers, and although nitric oxide is the major component, nitrite and nitrogen species are slightly co-adsorbed on the surface. The results obtained from this study are compared with those previously reported in the literature for NO adsorbed on Pt(111) under UHV conditions

Role of the exchange and correlation potential into calculating the x-ray absorption spectra of half-metallic alloys: the case of Mn and Cu K-edge XANES in Cu2_2MnM (M = Al, Sn, In) Heusler alloys

This work reports a theoretical study of the x-ray absorption near-edge structure spectra at both the Cu and the Mn K-edge in several Cu$_2$MnM (M= Al, Sn and In) Heusler alloys. Our results show that {\it ab-initio} single-channel multiple-scattering calculations are able of reproducing the experimental spectra. Moreover, an extensive discussion is presented concerning the role of the final state potential needed to reproduce the experimental data of these half-metallic alloys. In particular, the effects of the cluster-size and of the exchange and correlation potential needed in reproducing all the experimental XANES features are discussed.Comment: 15 pages, 5 figure

Study on Static Electrification of Palm Fatty Acid Ester (PFAE) Oil Using Mini Static Tester (Archive)

Palm fatty acid ester (PFAE) oil is an alternative insulating liquid of power transformer that has good biodegradable properties. As a part of insulating system of power transformer, PFAE should also has a low risk in term of static electrification that may degrade electrical strength of solid insulation due to charge accumulation at its surface during oil circulating. Charge potential value could describe the possibility of insulating oil in involving on charge accumulation at the surface of solid insulation. This can be calculated from charge density through electrostatic charge tendency (ECT) and volume resistivity. This study using mini-static-tester to measure ECT since it is easy to reproduce the specimen and suitable for standardization. Since PFAE has higher polarity than mineral oil, PFAE has larger charges than mineral oil. Even though static charges are estimated to generate on the pressboard surface easily, generated charges are estimated to escape from pressboard surface because of its lower resistivity. Variation of charge density and volume resistivity of several types (i.e. PFAE and mineral) and conditions (i.e. with-additives, non-additives, unused, and aged) of oil will influence to its charge potentia

Influenza C virus NS1 protein counteracts RIG-I-mediated IFN signalling

The nonstructural proteins 1 (NS1) from influenza A and B viruses are known as the main viral factors antagonising the cellular interferon (IFN) response, inter alia by inhibiting the retinoic acid-inducible gene I (RIG-I) signalling. The cytosolic pattern-recognition receptor RIG-I senses double-stranded RNA and 5'-triphosphate RNA produced during RNA virus infections. Binding to these ligands activates RIG-I and in turn the IFN signalling. We now report that the influenza C virus NS1 protein also inhibits the RIG-I-mediated IFN signalling. Employing luciferase-reporter assays, we show that expression of NS1-C proteins of virus strains C/JJ/50 and C/JHB/1/66 considerably reduced the IFN-β promoter activity. Mapping of the regions from NS1-C of both strains involved in IFN-β promoter inhibition showed that the N-terminal 49 amino acids are dispensable, while the C-terminus is required for proper modulation of the IFN response. When a mutant RIG-I, which is constitutively active without ligand binding, was employed, NS1-C still inhibited the downstream signalling, indicating that IFN inhibitory properties of NS1-C are not necessarily linked to an RNA binding mechanism

Cost-effectiveness comparison between palpation- and ultrasound-guided thyroid fine-needle aspiration biopsies

<p>Abstract</p> <p>Background</p> <p>The aim of this study is to perform a cost-effectiveness comparison between palpation-guided thyroid fine-needle aspiration biopsies (P-FNA) and ultrasound-guided thyroid FNA biopsies (USG-FNA).</p> <p>Methods</p> <p>Each nodule was considered as a case. Diagnostic steps were history and physical examination, TSH measurement, Tc^99mthyroid scintigraphy for nodules with a low TSH level, initial P-FNA versus initial USG-FNA, repeat USG-FNA for nodules with initial inadequate P-FNA or USG-FNA, hemithyroidectomy for inadequate repeat USG-FNA. American Thyroid Association thyroid nodule management guidelines were simulated in estimating the cost of P-FNA strategy. American Association of Clinical Endocrinologists guidelines were simulated for USG-FNA strategy. Total costs were estimated by adding the cost of each diagnostic step to reach a diagnosis for 100 nodules. Strategy cost was found by dividing the total cost to 100. Incremental cost-effectiveness ratio (ICER) was calculated by dividing the difference between strategy cost of USG-FNA and P-FNA to the difference between accuracy of USG-FNA and P-FNA. A positive ICER indicates more and a negative ICER indicates less expense to achieve one more additional accurate diagnosis of thyroid cancer for USG-FNA.</p> <p>Results</p> <p>Seventy-eight P-FNAs and 190 USG-FNAs were performed between April 2003 and May 2008. There were no differences in age, gender, thyroid function, frequency of multinodular goiter, nodule location and diameter (median nodule diameter: 18.4 mm in P-FNA and 17.0 mm in USG-FNA) between groups. Cytology results in P-FNA versus USG-FNA groups were as follows: benign 49% versus 62% (p = 0.04), inadequate 42% versus 29% (p = 0.03), malignant 3% (p = 1.00) and indeterminate 6% (p = 0.78) for both. Eleven nodules from P-FNA and 18 from USG-FNA group underwent surgery. The accuracy of P-FNA was 0.64 and USG-FNA 0.72. Unit cost of P-FNA was 148 Euros and USG-FNA 226 Euros. The cost of P-FNA strategy was 534 Euros and USG-FNA strategy 523 Euros. Strategy cost includes the expense of repeat USG-FNA for initial inadequate FNAs and surgery for repeat inadequate USG-FNAs. ICER was -138 Euros.</p> <p>Conclusion</p> <p>Universal application of USG-FNA for all thyroid nodules is cost-effective and saves 138 Euros per additional accurate diagnosis of benign versus malignant thyroid nodular disease.</p> <p>Trial registration</p> <p>ClinicalTrials.gov, NCT00571090</p