6,054 research outputs found

    Light-Controlled Direction of Distributed Feedback Laser Emission by Photo-Mobile Polymer Films

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    We report on the realization of Distributed Feedback (DFB) lasing by a high-resolution reflection grating integrated in a Photomobile Polymer (PMP) film. The grating is recorded in a recently developed holographic mixture basically containing halolakanes/acrylates and a fluorescent dye molecule (Rhodamine 6G). The PMP-mixture is placed around the grating spot and a subsequent curing/photo-polymerization process is promoted by UV-irradiation. Such a process brings to the simultaneous formation of the PMP-film and the covalent link of the PMP-film to the DFB-grating area (PMP-DFB system). The PMP-DFB allows lasing action when optically pumped with a nano-pulsed green laser source. Moreover, under a low-power light-irradiation the PMP-DFB bends inducing a spatial readdressing of the DFB-laser emission. This device is the first example of a light-controlled direction of a DFB laser emission. It could represent a novel disruptive optical technology in many fields of Science, making feasible the approach to free standing and light-controllable lasers

    HKUST-1-Doped High-Resolution Volume Holographic Gratings

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    We report on transmission holographic gratings doped with metal organic frameworks (MOFs). As a first attempt, we focused on MOF-199, also known as HKUST-1, which is an efficient adsorbent of VOCs. HKUST-1 is not soluble in the pre-polymerized holographic mixture. For this reason, samples containing HKUST-1 show high light scattering. In this work, the recording of HKUST-1-doped one-dimensional transmission phase gratings is demonstrated. The optical properties of the recorded structures, such as diffraction efficiency and average refractive index changes, are reported by using angular analysis measurements. A first attempt to demonstrate the possibility of using the doped gratings as sensors is also reported

    Analysis of viral nucleic acids in duodenal biopsies from adult patients with active celiac disease: in search for an etiological relationship

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    BACKGROUND AND AIM: Celiac Disease (CD) is a multisystemic chronic inflammatory autoimmune disease which develops in genetically predisposed subjects and it is triggered by the ingestion of gluten. After the interaction between HLA-DQ2/DQ8 and gluten-derived peptides, lymphocytes T CD4+ start a specific immune response which ends in a chronic inflammation and mucosal damage. CD pathogenesis is complex and not entirely understood, probably due to an alteration in the gastrointestinal immune system or to its aberrant regulation. Furthermore, many environmental and immune factors could be involved, particularly viral infections. The aim of the study was to observe possible relationships between CD and infections from HHV-6 A/B, EBV, CMV, adenovirus and rotavirus. MATERIAL AND METHODS: Thirty-nine adult patients (aged 18-65 yrs) have been enrolled: specifically, 24 duodenal biopsies from active CD patients and 15 biopsies from non-CD patients were analyzed. CD diagnosis has been performed by means of serological antibodies, histology of duodenal biopsies and duodenal biopsy organ culture. Viral nucleic acids were extracted from duodenal biopsies and then amplified using Real-Time PCR technique. RESULTS: HHV-6B was found in 62.5% of CD patients and in 73.3% of non-CD patients (p=0.13). EBV was found in 4.5% of CD patients and 6.7% of non-CD patients (p=0.35). Nucleic acids from HHV-6A, CMV, adenovirus and rotavirus were not detected in any group. HHV-6B viral load in CD patients was higher than in non-CD patients, but data were not statistically significant (p=0.54). CD patients with HHV-6B viral load >50000 copies/ml resulted to be younger and had lower anti-tTG antibody titers found at organ culture than patients with lower HHV-6B viral load (p>0.05). CONCLUSIONS: There seems to be no difference in viral load and/or in the detection of viruses between CD and non-CD patients. Thus, our data do not support the possible relationship between CD and viral infections, although a larger population is needed to confirm our study results

    Dual-curable stereolithography resins for superior thermomechanical properties

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    Stereolithography (SL) stands out as a relatively fast additive manufacturing method to produce thermoset components with high resolutions. The majority of SL resins consist of acrylate monomers which result in materials with cur-ing-induced shrinkage problems and this, in addition to the incomplete and non-uniform conversions reached in the SL process, results in poor mechanical properties. To address this issue, a dual-curing formulation was developed by mixing an epoxy monomer into a commercial multi-acrylate SL resin: the first curing stage is acrylate free-radical photopolymerization at ambient temperature, and the second curing stage is cationic epoxy homopolymerization at higher temperatures. The fully dual-cured materials are macroscopically homogeneous, with nanoscale domains observed by Atomic Force Mi-croscopy (AFM), and with unimodal tan delta peaks observed in Dynamic Mechanical Analysis (DMA). The uncured material was storage stable at ambient conditions for at least 9 weeks since the epoxy part was virtually unreactive at these temper-atures. With the dual-cured materials, a nearly 10-fold increase in Young’s modulus was achieved over the neat acrylate resin. At the thermal curing stage, the presence of diperoxyketal thermal radical initiator to the liquid formulation facilitated the polymerization of unreacted acrylates that remained from the SL process simultaneously with epoxy homopolymerization and helped the material attain improved properties

    Hepatobiliary disease resection in patients with advanced epithelial ovarian cancer: prognostic role and optimal cytoreduction

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    Objective: The purpose of this study was to evaluate the feasibility and safety in terms of prognostic significance and perioperative morbidity and mortality of cytoreduction in patients affected by advance ovarian cancer and hepato-biliary metastasis. Methods: Patients with a least one hepatobiliary metastasis who have undergone surgical treatment with curative intent of were considered for the study. Perioperative complications were evaluated and graded with Accordion severity Classification. Five-year PFS and OS were estimated using the Kaplan–Meier curve. Results: Sixty-seven (20.9%) patients had at least one metastasis to the liver, biliary tract, or porta hepatis. Forty-four (65.7%) and 23 (34.3%) patients underwent respectively high and intermediate complexity surgery according. Complete cytoreduction was achieved in 48 (71.6%) patients with hepato-biliary disease. In two patients (2.9%) severe complications related to hepatobiliary surgery were reported. The median PFS for the patients with hepato-biliary involvement (RT = 0 vs. RT > 0) was 19 months [95% confidence interval (CI) 16.2–21.8] and 8 months (95% CI 6.1–9.9). The median OS for the patients with hepato-biliary involvement (RT = 0 vs. RT > 0) 45 months (95% CI 21.2–68.8 months) and 23 months (95% CI 13.9–32.03). Conclusions: Hepatobiliary involvement is often associated with high tumor load and could require high complex multivisceral surgery. In selected patients complete cytoreduction could offer survival benefits. Morbidity related to hepatobiliary procedures is acceptable. Careful evaluation of patients and multidisciplinary approach in referral centers is mandatory

    Role of extracellular microvesicles in celiac disease as potential pathogenetic agents and biomarkers of intestinal inflammation

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    BACKGROUND AND AIM: Celiac Disease (CD) is a chronic intestinal disease caused by the ingestion of gluten. Microvesicles (MVs) belong to a heterogeneous population, released by cells both in homeostasis and pathological conditions. MVs can be considered mediators of inflammation and potential biomarkers. The aim of this study is: 1) to evaluate the possible role of MVs in the propagation of inflammation in CD, using MVs purified by supernatant of duodenal biopsies from CD patients; 2) to identify potential biomarkers by proteomic analysis of pasma-derived MVs from CD patients. MATERIAL AND METHODS: MVs were isolated by molecular exclusion chromatography and ultracentrifugation respectively from plasma and culture supernatant of duodenal biopsies of 10 active CD, 5 remission CD and 6 controls. Proteomic analysis of plasma-derived MVs was performed by mass spectrometry. The possible effects of duodenal-derived MVs on confluent Caco-2 cells were evaluated by measuring Transepithelial Electrical Resistance (TEER) and analyzing the expression of actin, tissue transglutaminase (TG2) and Zonula Occludens-1 (ZO-1). The dosage of IL-8 in the Caco-2 culture supernatant was carried out by ELISA test. The statistical analysis of the data obtained was performed using the Student's t-test. RESULTS: The proteomic analysis of circulating MVs showed 8 proteins from desmosome and cytoskeleton (desmoglein-1 and gamma-enteric actin) associated with the active phase of the disease. Caco-2 cells, treated with the MVs purified from the duodenal biopsies of active CD patients showed: 1) rearrangement of actin filaments; 2) increased expression of TG2; 3) decreased expression of the ZO-1 protein, although an alteration of intestinal permeability was not observed. The analysis of Caco-2 cell supernatants showed a statistically significant increase in IL-8 (p <0.05), in the presence of MVs isolated from biopsies of active CD patients, compared to remission CD patients and controls. CONCLUSIONS: MVs isolated from plasma of active CD patients could represent potential diagnostic and prognostic biomarkers. Although they don’t induce changes in intestinal permeability, MVs could contribute to inflammatory cascade increasing IL-8 production

    Measurement of {\eta} meson production in {\gamma}{\gamma} interactions and {\Gamma}({\eta}-->{\gamma}{\gamma}) with the KLOE detector

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    We present a measurement of {\eta} meson production in photon-photon interactions produced by electron-positron beams colliding with \sqrt{s}=1 GeV. The measurement is done with the KLOE detector at the \phi-factory DA{\Phi}NE with an integrated luminosity of 0.24 fb^{-1}. The e^+e^- --> e^+e^-{\eta} cross section is measured without detecting the outgoing electron and positron, selecting the decays {\eta}-->{\pi}^+{\pi}^-{\pi}^0 and {\eta}-->{\pi}^0{\pi}^0{\pi}^0. The most relevant background is due to e^+e^- --> {\eta}{\gamma} when the monochromatic photon escapes detection. The cross section for this process is measured as {\sigma}(e^+e^- -->{\eta}{\gamma}) = (856 \pm 8_{stat} \pm 16_{syst}) pb. The combined result for the e^+e^- -->e^+e^-{\eta} cross section is {\sigma}(e^+e^- -->e^+e^-{\eta}) = (32.72 \pm 1.27_{stat} \pm 0.70_{syst}) pb. From this we derive the partial width {\Gamma}({\eta}-->{\gamma}{\gamma}) = (520 \pm 20_{stat} \pm 13_{syst}) eV. This is in agreement with the world average and is the most precise measurement to date.Comment: Version accepted by JHE

    A new limit on the CP violating decay KS -> 3pi0 with the KLOE experiment

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    We have carried out a new direct search for the CP violating decay KS -> 3pi0 with 1.7 fb^-1 of e+e- collisions collected by the KLOE detector at the phi-factory DAFNE. We have searched for this decay in a sample of about 5.9 x 10^8 KS KL events tagging the KS by means of the KL interaction in the calorimeter and requiring six prompt photons. With respect to our previous search, the analysis has been improved by increasing of a factor four the tagged sample and by a more effective background rejection of fake KS tags and spurious clusters. We find no candidates in data and simulated background samples, while we expect 0.12 standard model events. Normalizing to the number of KS -> 2pi0 events in the same sample, we set the upper limit on BR(KS -> 3pi0 < 2.6 x 10^-8 at 90% C.L., five times lower than the previous limit. We also set the upper limit on the eta_000 parameter, |eta_000 | < 0.0088 at 90% C.L., improving by a factor two the latest direct measurement.Comment: Accepted for publication in Physics Letters B (15 pages, 13 figures
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