145 research outputs found

    Liquid crystal cells based on photovoltaic substrates

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    Liquid crystal cells with LiNbO3:Fe crystals as substrates, are described. The photovoltaic field generated by the substrates is able to reorient the liquid crystal director thus giving rise to a phase shift on the light propagating through the cell, as in liquid crystal light valves. The process does not require the application of an external electric field, thus being potentially useful for applications requiring a high degree of compactness. An efficient optical switch with a high transmission contrast, based on the described optically-induced electric field, is also proposed

    LiNbO3 integrated system for opto-microfluidic sensing

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    International audience; In this work, we realized and tested an integrated opto-microfluidics platform entirely made on lithium niobate (LiNbO3) crystals, able to detect the single droplet passage and estimate its size without the need of any imaging processing. It is based on the coupling of a self-aligned integrated optical stage, made of an array of optical waveguides, to a microfluidic circuit such as a T-junction or Cross-junction engraved in the same substrate. The platform presented high quality performances in terms of optical triggering, reproducibility and stability in time, allowing in real-time data analysis. The comparison with standard approaches using microscopes and fast camera imagining acquisition and relative post-processing, showed an increased capability better than 50%. The demonstrated feasibility of integration of these two stages will allow the realization of a Lab-On-a-Chip on a monolithic substrate of lithium niobate, exploiting its multiple applications for manipulation of droplets

    T-junction droplet generator realised in lithium niobate crystals by laser ablation

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    AbstractA femtosecond laser at 800 nm was used to create micro-fluidic circuits on lithium niobate (LiNbO3) substrates by means of laser ablation, using different scanning velocities (100-500 μm/s) and laser pulse energies (1-20 μJ). The T-junction geometry was exploited to create on y-cut LiNbO3 crystals a droplet generator, whose microfluidic performance was characterized in a wide range of droplet generation frequencies, from few Hz to about 1 kHz

    Trends in chronic hepatitis B virus infection in Italy over a 10-year period: Clues from the nationwide PITER and MASTER cohorts toward elimination

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    Objectives: The study measures trends in the profile of patients with chronic hepatitis B virus linked to care in Italy. Methods: A cross-sectional, multicenter, observational cohort (PITER cohort) of consecutive patients with hepatitis B surface antigen (HBsAg) over the period 2019-2021 from 46 centers was evaluated. The reference was the MASTER cohort collected over the years 2012-2015. Standard statistical methods were used. Results: The PITER cohort enrolled 4583 patients, of whom 21.8% were non-Italian natives. Compared with those in MASTER, the patients were older and more often female. The prevalence of hepatitis B e antigen (HBeAg) declined (7.2% vs 12.3; P <0.0001) and that of anti-hepatitis D virus (HDV) remained stable (9.3% vs 8.3%). In both cohorts, about 25% of the patients had cirrhosis, and those in the PITER cohort were older. HBeAg-positive was 5.0% vs 12.6% (P <0.0001) and anti-HDV positive 24.8% vs 17.5% (P <0.0017). In the logistic model, the variables associated with cirrhosis were anti-HDV-positive (odds ratio = 10.08; confidence interval 7.63-13.43), age, sex, and body mass index; the likelihood of cirrhosis was reduced by 40% in the PITER cohort. Among non-Italians, 12.3% were HBeAg-positive (vs 23.4% in the MASTER cohort; P <0.0001), and 12.3% were anti-HDV-positive (vs 11.1%). Overall, the adherence to the European Association for the Study of the Liver recommendations for antiviral treatment increased over time. Conclusion: Chronic hepatitis B virus infection appears to be in the process of becoming under control in Italy; however, HDV infection is still a health concern in patients with cirrhosis and in migrants

    Clinical features and comorbidity pattern of HCV infected migrants compared to native patients in care in Italy: A real-life evaluation of the PITER cohort

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    Background: Direct-acting antivirals are highly effective for the treatment of hepatitis C virus (HCV) infection, regardless race/ethnicity. We aimed to evaluate demographic, virological and clinical data of HCV-infected migrants vs. natives consecutively enrolled in the PITER cohort. Methods: Migrants were defined by country of birth and nationality that was different from Italy. Mann-Whitney U test, Chi-squared test and multiple logistic regression were used. Results: Of 10,669 enrolled patients, 301 (2.8%) were migrants: median age 47 vs. 62 years, (p < 0.001), females 56.5% vs. 45.3%, (p < 0.001), HBsAg positivity 3.8% vs. 1.4%, (p < 0.05). Genotype 1b was prevalent in both groups, whereas genotype 4 was more prevalent in migrants (p < 0.05). Liver disease severity and sustained virologic response (SVR) were similar. A higher prevalence of comorbidities was reported for natives compared to migrants (p < 0.05). Liver disease progression cofactors (HBsAg, HIV coinfection, alcohol abuse, potential metabolic syndrome) were present in 39.1% and 47.1% (p > 0.05) of migrants and natives who eradicated HCV, respectively. Conclusion: Compared to natives, HCV-infected migrants in care have different demographics, HCV genotypes, viral coinfections and comorbidities and similar disease severity, SVR and cofactors for disease progression after HCV eradication. A periodic clinical assessment after HCV eradication in Italians and migrants with cofactors for disease progression is warranted

    L'Italia come modello per l'Europa e per il mondo nelle politiche sanitarie per il trattamento dell'epatite cronica da HCV

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    The World Health Organization foresees the elimination of HCV infection by 2030. In light of this and the curre nt, nearly worldwide, restriction in direct-acting agents (DAA) accessibility due to their high price, we aimed to evaluate the cost-effectiveness of two alternative DAA treatment policies: Policy 1 (universal): treat all patients, regardless of the fibrosis stage; Policy 2 (prioritized): treat only priori tized patients and delay treatment of the remaining patients until reaching stage F3. T he model was based on patient’s data from the PITER cohort. We demonstrated that extending HC V treatment of patients in any fibrosis stage improves health outcomes and is cost-effective

    Economic consequences of investing in anti-HCV antiviral treatment from the Italian NHS perspective : a real-world-based analysis of PITER data

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    OBJECTIVE: We estimated the cost consequence of Italian National Health System (NHS) investment in direct-acting antiviral (DAA) therapy according to hepatitis C virus (HCV) treatment access policies in Italy. METHODS: A multistate, 20-year time horizon Markov model of HCV liver disease progression was developed. Fibrosis stage, age and genotype distributions were derived from the Italian Platform for the Study of Viral Hepatitis Therapies (PITER) cohort. The treatment efficacy, disease progression probabilities and direct costs in each health state were obtained from the literature. The break-even point in time (BPT) was defined as the period of time required for the cumulative costs saved to recover the Italian NHS investment in DAA treatment. Three different PITER enrolment periods, which covered the full DAA access evolution in Italy, were considered. RESULTS: The disease stages of 2657 patients who consecutively underwent DAA therapy from January 2015 to December 2017 at 30 PITER clinical centres were standardized for 1000 patients. The investment in DAAs was considered to equal €25 million, €15 million, and €9 million in 2015, 2016, and 2017, respectively. For patients treated in 2015, the BPT was not achieved, because of the disease severity of the treated patients and high DAA prices. For 2016 and 2017, the estimated BPTs were 6.6 and 6.2 years, respectively. The total cost savings after 20 years were €50.13 and €55.50 million for 1000 patients treated in 2016 and 2017, respectively. CONCLUSIONS: This study may be a useful tool for public decision makers to understand how HCV clinical and epidemiological profiles influence the economic burden of HCV
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