Advanced Virgo

The upgrade of Virgo to Advanced Virgo has been completed in 2016. The detector is now being commissioned, with the goal of starting taking data with the two LIGO interferometers during summer 2017

Interrelation between microstructure and optical properties of erbium-doped nanocrystalline thin films

Nanocrystalline silicon thin films codoped with erbium, oxygen and hydrogen have been deposited by co-sputtering of Er and Si. Films with different crystallinity, crystallite size and oxygen content have been obtained in order to investigate the effect of the microstructure on the photoluminescence properties. The correlation between the optical properties and microstructural parameters of the films is investigated by spectroscopic ellipsometry. PL response of the discussed structures covers both the visible wavelength range (a crystallite size-dependent photoluminescence detected for 5–6 nm sized nanocrystals embedded in a SiO matrix) and near IR range at 1.54 microm (Er-related PL dominating in the films with 1–3 nm sized Si nanocrystals embedded in a-Si:H). It is demonstrated that the different PL properties can be also discriminated on the basis of ellipsometric spectra

Human leukocyte antigen (Hla) haplotype does not influence the inflammatory pattern of duodenal lymphocytosis linked to irritable bowel syndrome

Background and objectives: Duodenal lymphocytosis (DL) is a condition characterized by enhanced infiltration of intraepithelial lymphocytes (IELs) in the duodenal mucosa, and it can be linked to both gluten-and non-gluten-related diseases, such as irritable bowel syndrome (IBS). Materials and methods: We retrospectively selected patients with DL linked to IBS. Formalin-embedded biopsy samples of the duodenum were collected. CD3 lymphocyte immunohistochemistry was used for IELs. The real-time polymerase chain reaction was used to quantify the amount of mRNA coding for tissue transglutaminase 2 (tTG2), interferon-gamma (IFNγ), toll-like receptor 2 (TLR2), and myeloid differentiation primary response 88 (MyD88). All subjects underwent DQ2-8 haplotype analysis. Controls were represented by subjects with IBS without DL. Results: Thirty-two patients with IBS-DL were retrospectively recruited. Fourteen subjects (43.8%) had a DQ2-8 haplotype. DQ2-8 positive subjects had similar levels compared to negative ones for tTG2, IFNγ, TLR2, and MyD88. Cigarette smoke did not influence molecular expression in our study. Smokers had a statistically higher IELs count than non-smokers (54.2 ± 7.7 vs. 36.0 ± 8.8, p < 0.001). A significant, direct correlation between IELs and duodenal expression of IFNγ was found (r = 0.36, p = 0.04). Conclusions: IBS with DL showed higher expression of inflammatory markers than controls, but DQ2-8 haplotype did not seem to affect their expression. Smoking might increase IELs infiltration

Chronic viral hepatitis in a cohort of inflammatory bowel disease patients from southern Italy: A case-control study

We performed an epidemiologic study to assess the prevalence of chronic viral hepatitis in inflammatory bowel disease (IBD) and to detect their possible relationships. Methods: It was a single centre cohort cross-sectional study, during October 2016 and October 2017. Consecutive IBD adult patients and a control group of non-IBD subjects were recruited. All patients underwent laboratory investigations to detect chronic hepatitis B (HBV) and C (HCV) infection. Parameters of liver function, elastography and IBD features were collected. Univariate analysis was performed by Student’s t or chi-square test. Multivariate analysis was performed by binomial logistic regression and odds ratios (ORs) were calculated. We enrolled 807 IBD patients and 189 controls. Thirty-five (4.3%) had chronic viral hepatitis: 28 HCV (3.4%, versus 5.3% in controls, p = 0.24) and 7 HBV (0.9% versus 0.5% in controls, p = 0.64). More men were observed in the IBD-hepatitis group (71.2% versus 58.2%, p < 0.001). Patients with IBD and chronic viral hepatitis had a higher mean age and showed a higher frequency of diabetes, hypertension and wider waist circumference. They suffered more frequently from ulcerative colitis. Liver stiffness was greater in subjects with IBD and chronic viral hepatitis (7.0 ± 4.4 versus 5.0 ± 1.2 KPa; p < 0.001). At multivariate analysis, only old age directly correlated with viral hepatitis risk (OR = 1.05, 95%CI 1.02-1.08, p < 0.001). In conclusion, the prevalence of HBV/HCV in IBD is low in our region. Age may be the only independent factor of viral hepatitis-IBD association. Finally, this study firstly measured liver stiffness in a large scale, showing higher values in subjects with both diseases

Estrogen receptors in colorectal cancer: Facts, novelties and perspectives

Colorectal cancer (CRC) is the second cause of cancer-related death in both sexes worldwide. As pre-menopausal women are less likely to develop CRC compared to age-matched men, a protective role for estrogens has been hypothesized. Indeed, two isoforms of nuclear estrogen receptors (ER) have been described: ERα and ERβ. While the binding of 17beta-estradiol to ERα activates anti-apoptotic pathways, the interaction with ERβ activates caspase-3, inducing apoptosis. In this regard, several pieces of evidence show that ERβ tends to be under-regulated in advanced adenomas and CRC, with an opposite trend for ERα. Furthermore, ERβ stimulation slows adenomatous polyp growth and modulates relevant CRC pathways. Based on such considerations, dietary modulation of ER is promising, particularly in subjects with genetic predisposition for CRC. Nevertheless, the main limitation is the lack of clinical trials on a large population scale

Dielectric function of nanocrystalline silicon with few nanometers (<3 nm) grain size

The dielectric function of nanocrystalline silicon (nc-Si) with crystallite size in the range of 1 to 3 nm has been determined by spectroscopic ellipsometry in the range of 1.5 to 5.5 eV. ATauc–Lorentz parameterization is used to model the nc-Si optical properties. The nc-Si dielectric function can be used to analyze nondestructively nc-Si thin films where nanocrystallites cannot be detected by x-ray diffraction and Raman spectroscopy

Photoluminescence of nc-Si:Er thin films obtained by physical and chemical vapour deposition techniques: The effects os microstructure and chemical composition

Erbium doped nanocrystalline silicon (nc-Si:Er) thin films were produced by reactive magnetron rf sputtering and by Er ion implantation into chemical vapor deposited Si films. The structure and chemical composition of films obtained by the two approaches were studied by micro-Raman scattering, spectroscopic ellipsometry and Rutherford backscattering techniques. Variation of deposition parameters was used to deposit films with different crystalline fraction and crystallite size. Photoluminescence measurements revealed a correlation between film microstructure and the Er3+ photoluminescence efficiency.FCT Project POCTI/CTM/39395/2001INTAS Project #03-51-648

Wet chemical nitridation of GaAs (100) by hydrazine solution for surface passivation

A mild wet nitridation procedure using hydrazine-based solutions has been developed for GaAs (100) surface passivation. Both x-ray photoelectron spectroscopy and spectroscopic ellipsometry show that this nitridation procedure results in a very thin, coherent, and homogeneous GaN layer that is very stable in air. Photoluminescence data show a strong enhancement of the intensity as compared to that of an as-cleaned GaAs sample, indicating that this nitrided layer provides both chemical and electronic passivation of GaAs surfaces. The chemical mechanism of nitridation is discusse

Testing the performance of a blind burst statistic

In this work we estimate the performance of a method for the detection of burst events in the data produced by interferometric gravitational wave detectors. We compute the receiver operating characteristics in the specific case of a simulated noise having the spectral density expected for Virgo, using test signals taken from a library of possible waveforms emitted during the collapse of the core of Type II Supernovae.Comment: 8 pages, 6 figures, Talk given at the GWDAW2002 worksho

QUADRUPLE RESCUE THERAPY AFTER FIRST AND SECOND LINE FAILURE FOR HELICOBACTER PYLORI TREATMENT: COMPARISON BETWEEN TWO TETRACYCLINE-BASED REGIMENS

Background &amp; Aims: Antibiotic resistance is the main reason for failure of Helicobacter pylori (H. pylori) treatment. Currently, guidelines recommend a treatment guided by antimicrobial susceptibility testing after two failures. However, microbial culture is not feasible everywhere, and the limited number of effective antibiotics against the bacterium narrows the options; thus a rescue therapy combining antibiotics with a low resistance may be fitting. Methods: Patients who have failed a first-line treatment (either prolonged triple or sequential regimens) and, successively, a levofoxacin-based triple therapy were considered for the study. Subjects underwent urea breath test (UBT), stool antigen test (ST) and endoscopy/histology to confirm the diagnosis. Cytopenia and impaired liver and kidney function were exclusion criteria. Fify-four subjects were randomized 1:1 to two regimens: RMB abeprazole/Rifabutin/Minocycline/Bismuth sub-citrate or MTB Rabeprazole/Tinidazole/ Minocycline/Bismuth sub-citrate both for 10 days. Te results were checked 6 weeks afer the end of therapy with ST/UBT plus endoscopy when indicated. Results: RMB eradicated the bacterium in 21 patients. Two subjects dropped out. Te eradication rate was 77.7% (CI 62.0-93.4%) at intention-to-treat and 84.0% (CI 69.6-98.4%) at per-protocol analysis. MTB was successful in 14 patients (51.9%, CI 33.1-70.7%). No patient withdrew from the treatment for adverse events. Drug-related side effects were reported only in 3 subjects, but in all cases the treatment was carried on. Conclusions: Te association minocycline/rifabutin seems to have a synergic effect and a good therapeutic outcome in patients who have failed at least two previous regimens, although a trial on a large population is needed