20 research outputs found

    Improving liquid chromatography efficiency: channels structured with micro-pillars

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    Band dispersion has been measured in micromachined separation channels structured with orderly disposed cylindrical micropillars. It was found that with an optimal channel design the band broadening could be lower by a factor of 3 than in packed columns with a comparable particle size. The positioning of the row of pillars closest to the side wall was a decisive factor in influencing band broadening

    Experimental investigation of the band broadening originating from the top and bottom wall in micromachined non-porous pillar array columns

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    We report on the experimental investigation of the effect of the top and bottom wall plates in micromachined nonporous pillar array columns. It has been found that their presence yields an additional c-term type of band broadening that can make up a significant fraction of the total band broadening (at least if considering nonporous pillars and a nonretained tracer). Their presence also induces a clear (downward) shift of the optimal velocity. These observations are, however in excellent quantitative agreement with the theoretical expectations obtained from a computational fluid dynamics study. The presently obtained experimental results, hence, demonstrate that the employed high aspect ratio Bosch etching process can be used to fabricate micromachined pillar arrays that are sufficiently refined to achieve the theoretical performance limit

    Lopinavir/Ritonavir and Darunavir/Cobicistat in Hospitalized COVID-19 Patients: Findings From the Multicenter Italian CORIST Study

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    Background: Protease inhibitors have been considered as possible therapeutic agents for COVID-19 patients. Objectives: To describe the association between lopinavir/ritonavir (LPV/r) or darunavir/cobicistat (DRV/c) use and in-hospital mortality in COVID-19 patients. Study Design: Multicenter observational study of COVID-19 patients admitted in 33 Italian hospitals. Medications, preexisting conditions, clinical measures, and outcomes were extracted from medical records. Patients were retrospectively divided in three groups, according to use of LPV/r, DRV/c or none of them. Primary outcome in a time-to event analysis was death. We used Cox proportional-hazards models with inverse probability of treatment weighting by multinomial propensity scores. Results: Out of 3,451 patients, 33.3% LPV/r and 13.9% received DRV/c. Patients receiving LPV/r or DRV/c were more likely younger, men, had higher C-reactive protein levels while less likely had hypertension, cardiovascular, pulmonary or kidney disease. After adjustment for propensity scores, LPV/r use was not associated with mortality (HR = 0.94, 95% CI 0.78 to 1.13), whereas treatment with DRV/c was associated with a higher death risk (HR = 1.89, 1.53 to 2.34, E-value = 2.43). This increased risk was more marked in women, in elderly, in patients with higher severity of COVID-19 and in patients receiving other COVID-19 drugs. Conclusions: In a large cohort of Italian patients hospitalized for COVID-19 in a real-life setting, the use of LPV/r treatment did not change death rate, while DRV/c was associated with increased mortality. Within the limits of an observational study, these data do not support the use of LPV/r or DRV/c in COVID-19 patients

    Experimental investigation of the band broadening originating from the top and bottom walls in micromachined nonporous pillar array columns\ud

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    We report on the experimental investigation of the effect of the top and bottom wall plates in micromachined nonporous pillar array columns. It has been found that their presence yields an additional c-term type of band broadening that can make up a significant fraction of the total band broadening (at least if considering nonporous pillars and a nonretained tracer). Their presence also induces a clear (downward) shift of the optimal velocity. These observations are, however in excellent quantitative agreement with the theoretical expectations obtained from a computational fluid dynamics study. The presently obtained experimental results, hence, demonstrate that the employed high aspect ratio Bosch etching process can be used to fabricate micromachined pillar arrays that are sufficiently refined to achieve the theoretical performance limit.\ud \u

    Forest plantations in Southwestern Europe: A comparative trend analysis on investment returns, markets and policies

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    This paper represents the first analysis of forest plantation investments on a comparative perspective in the context of Southwestern Europe. We estimated and compared potential investment returns at aggregate level for some of the most important productive forest plantation species in the region, including hybrid poplar in northern Italy, in Castile and Le\uf3n (Spain) and in Navarre (Spain), eucalyptus and maritime pine in Portugal, and radiata pine in the Basque Country (Spain). We carried out a financial analysis before-taxes, using typical capital budgeting indicators. Indicators were calculated according to a baseline scenario as well as in alternative scenarios, analyzing how the main policy and market factors influence returns. We also carried out a trend analysis to provide means for comparing the evolution of expected and actual returns in recent years. Overall, our results indicate that in Southwestern Europe there are some opportunities for reasonably attractive investment returns (IRR > 5%) from forest plantations mainly for current landowners and forest products industry, and only in some cases potentially interesting also for financial investors. Nevertheless, there are significant differences among species and contexts as well as structural limitations in the region \u2013 i.e. related to timber market, biotic and abiotic risks and forest holdings structure \u2013 that new investors would have to take into consideration. More in specific, hybrid poplar plantations in Italy and Spain are estimated to provide on average the potentially highest returns, but the large range of variability and the high land and opportunity costs are unlikely to make them an attractive investment for non-landowners. Eucalyptus plantations in Portugal are estimated to be the only investment where non-landowners could expect to get relatively interesting and stable returns, although a recent law reform in the country could limit new investments. Maritime pine and radiata pine plantations in Portugal and Spain present lower returns, suffering the situation of depressed stumpage prices after the 2008 economic crisis, which strongly affected the sawmilling sector

    O programa de qualidade no setor hospitalar e as atividades reais da enfermagem: o caso da medicação The quality program in the hospital sector and the nursing activities: the medication case

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    O objetivo deste estudo é analisar a política de qualidade implementada pela gestão hospitalar na farmácia central e as características da atividade de medicar realizada pelo auxiliar de enfermagem (AE). Adotou-se a abordagem proposta pela escola francesa de ergonomia. Avaliou-se o funcionamento do hospital e estudou-se a atividade do trabalho do AE em tempo real, possibilitando compreender as dificuldades enfrentadas no cotidiano e as estratégias implementadas. Viu-se que a atividade de trabalho está inserida num paradoxo organizacional em que a qualidade exigida para o cumprimento da missão de medicar dificulta o cumprimento da própria tarefa, comprometendo, em última análise, a assistência ao paciente.<br>The aim of this study is to analyze the quality policy implemented by the hospital management in the central chemistry and the characteristics of the medication activities performed by the nursing assistants (NA).The approach of the French School of Ergonomics was adopted. It was assessed the Hospital working situation and the activity performed by the nursing assistant in real time which have allowed to understand the difficulties faced by the workers and the strategies adopted to overcome them. It was observed that the working activity is part of an organizational paradox where the expected quality to fulfil the medication mission has been difficult to achieve, endangering, ultimately the assistance to the patients

    Lopinavir/Ritonavir and Darunavir/Cobicistat in Hospitalized COVID-19 Patients: Findings From the Multicenter Italian CORIST Study

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    Background: Protease inhibitors have been considered as possible therapeutic agents for COVID-19 patients. Objectives: To describe the association between lopinavir/ritonavir (LPV/r) or darunavir/cobicistat (DRV/c) use and in-hospital mortality in COVID-19 patients. Study Design: Multicenter observational study of COVID-19 patients admitted in 33 Italian hospitals. Medications, preexisting conditions, clinical measures, and outcomes were extracted from medical records. Patients were retrospectively divided in three groups, according to use of LPV/r, DRV/c or none of them. Primary outcome in a time-to event analysis was death. We used Cox proportional-hazards models with inverse probability of treatment weighting by multinomial propensity scores. Results: Out of 3,451 patients, 33.3% LPV/r and 13.9% received DRV/c. Patients receiving LPV/r or DRV/c were more likely younger, men, had higher C-reactive protein levels while less likely had hypertension, cardiovascular, pulmonary or kidney disease. After adjustment for propensity scores, LPV/r use was not associated with mortality (HR = 0.94, 95% CI 0.78 to 1.13), whereas treatment with DRV/c was associated with a higher death risk (HR = 1.89, 1.53 to 2.34, E-value = 2.43). This increased risk was more marked in women, in elderly, in patients with higher severity of COVID-19 and in patients receiving other COVID-19 drugs. Conclusions: In a large cohort of Italian patients hospitalized for COVID-19 in a real-life setting, the use of LPV/r treatment did not change death rate, while DRV/c was associated with increased mortality. Within the limits of an observational study, these data do not support the use of LPV/r or DRV/c in COVID-19 patients
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