The synthesis of maleic anhydride: study of a new process and improvement of the industrial catalyst

Maleic anhydride is an important chemical intermediate mainly produced by the selective oxidation of n-butane, an industrial process catalyzed by vanadyl pyrophosphate-based materials, (VO)2P2O7. The first topic was investigated in collaboration with a company specialized in the production of organic anhydrides (Polynt SpA), with the aim of improving the performance of the process for the selective oxidation of n-butane to maleic anhydride, comparing the behavior of an industrial vanadyl pyrophosphate catalysts when utilized either in the industrial plant or in lab-scale reactor. The study was focused on how the catalyst characteristics and reactivity are affected by the reaction conditions and how the addition of a dopant can enhance the catalytic performance. Moreover, the ageing of the catalyst was studied, in order to correlate the deactivation process with the modifications occurring in the catalyst. The second topic was produced within the Seventh Framework (FP7) European Project “EuroBioRef”. The study was focused on a new route for the synthesis of maleic anhydride starting from an alternative reactant produced by fermentation of biomass:“bio-1-butanol”. In this field, the different possible catalytic configurations were investigated: the process was divided into two main reactions, the dehydration of 1-butanol to butenes and the selective oxidation of butenes to maleic anhydride. The features needed to catalyze the two steps were analyzed and different materials were proposed as catalysts, namely Keggin-type polyoxometalates, VOPO4∙2H2O and (VO)2P2O7. The reactivity of 1-butanol was tested under different conditions, in order to optimize the performance and understand the nature of the interaction between the alcohol and the catalyst surface. Then, the key intermediates in the mechanism of 1-butanol oxidehydration to MA were studied, with the aim of understanding the possible reaction mechanism. Lastly, the reactivity of the chemically sourced 1-butanol was compared with that one of different types of bio-butanols produced by biomass fermentation.

Study of the effect of minor compounds on the oxidative stability and physical properties of bulk oil, oil-in-water emulsion, and food emulsions

Minor components are of particular interest due to their antioxidant and biological properties. Various classes of lipophilic minor components (plant sterols (PS) and α-tocopherol) were selected as they are widely used in the food industry. A Fast GC-MS method for PS analysis in functional dairy products was set up. The analytical performance and significant reduction of the analysis time and consumables, demonstrated that Fast GC-MS could be suitable for the PS analysis in functional dairy products. Due to their chemical structure, PS can undergo oxidation, which could be greatly impacted by matrix nature/composition and thermal treatments. The oxidative stability of PS during microwave heating was evaluated. Two different model systems (PS alone and in combination) were heated up to 30 min at 1000 W. PS degraded faster when they were alone than in presence of TAG. The extent of PS degradation depends on both heating time and the surrounding medium, which can impact the quality and safety of the food product destined to microwave heating/cooking. Many minor lipid components are included in emulsion systems and can affect the rate of lipid oxidation. The oxidative stability of oil-in-water (O/W) emulsions containing PS esters, ω-3 FA and phenolic compounds, were evaluated after a 14-day storage at room temperature. Due to their surface active character, PS could be particularly prone to oxidation when they are incorporated in emulsions, as they are more exposed to water-soluble prooxidants. Finally, some minor lipophilic components may increase oxidative stability of food systems due to their antioxidant activity. á-tocopherol partitioning and antioxidant activity was determined in the presence of excess SDS in stripped soybean O/W emulsions. Results showed that surfactant micelles could play a key role as an antioxidant carrier, by potentially increasing the accessibility of hydrophobic antioxidant to the interface.

Variational Monte Carlo study of the hydrogen electronic structure at ultra-high pressure

Die causa finalis der vorliegenden Arbeit ist das Verständnis des Phasendiagramms von Wasserstoff bei ultrahohen Drücken, welche von nichtleitendem H2 bis hin zu metallischem H reichen. Da die Voraussetzungen für ultrahohen Druck im Labor schwer zu schaffen sind, bilden Computersimulationen ein wichtiges alternatives Untersuchungsinstrument. Allerdings sind solche Berechnungen eine große Herausforderung. Eines der größten Probleme ist die genaue Auswertung des Born-Oppenheimer Potentials, welches sowohl für die nichtleitende als auch für die metallische Phase geeignet sein muss. Außerdem muss es die starken Korrelationen berücksichtigen, die durch die kovalenten H2 Bindungen und die eventuellen Phasenübergänge hervorgerufen werden. Auf dieses Problem haben unsere Anstrengungen abgezielt. Im Kontext von Variationellem Monte Carlo (VMC) ist die Shadow Wave Function (SWF) eine sehr vielversprechende Option. Aufgrund ihrer Flexibilität sowohl lokalisierte als auch delokalisierte Systeme zu beschreiben sowie ihrer Fähigkeit Korrelationen hoher Ordnung zu berücksichtigen, ist sie ein idealer Kandidat für unsere Zwecke. Unglücklicherweise bringt ihre Formulierung ein Vorzeichenproblem mit sich, was die Anwendbarkeit limitiert. Nichtsdestotrotz ist es möglich diese Schwierigkeit zu umgehen indem man die Knotenstruktur a priori festlegt. Durch diesen Formalismus waren wir in der Lage die Beschreibung der Elektronenstruktur von Wasserstoff signifikant zu verbessern, was eine sehr vielversprechende Perspektive bietet. Während dieser Forschung haben wir also die Natur des Vorzeichenproblems untersucht, das sich auf die SWF auswirkt, und dabei ein tieferes Verständnis seines Ursprungs erlangt. Die vorliegende Arbeit ist in vier Kapitel unterteilt. Das erste Kapitel führt VMC und die SWF mit besonderer Ausrichtung auf fermionische Systeme ein. Kapitel 2 skizziert die Literatur über das Phasendiagramm von Wasserstoff bei ultrahohem Druck. Das dritte Kapitel präsentiert die Implementierungen unseres VMC Programms und die erhaltenen Ergebnisse. Zum Abschluss fasst Kapitel 4 unsere Bestrebungen zur Lösung des zur SWF zugehörigen Vorzeichenproblems zusammen.

Sicurezza stradale: Proposta di traduzione di un estratto del research report "The Nature of Errors Made by Drivers"

The aim of this dissertation is to provide a translation from English into Italian of an extract from the research report “The Nature of Errors Made by Drivers”. The research was conducted by the MUARC (the Monash University Accident Research Centre) and published in June 2011 by Austroads, the association of Australasian road transport and traffic agencies. The excerpt chosen for translation is the third chapter, which provides an overview of the on-road pilot study conducted to analyse why drivers make mistakes during their everyday drive, including the methodology employed and the results obtained. This work is divided into six sections. It opens with an introduction on the topic and the formal structure of the report, followed by the first chapter, which provides an overview of the main features of the languages for special purposes and the specialised texts, an analysis of the text type and a presentation of the extract chosen for translation. In the second chapter the linguistic and extralinguistic resources available to specialised translators are presented, focussing on the ones used to translate the text. The third chapter is dedicated to the source text and its translation, while the fourth one provides an analysis of the strategies chosen to translate the text and a comment on the solutions to problematic passages. Finally, the last section – the conclusion – provides a comment on the entire work and on the professional activity of translators. The work closes with an appendix, which contains a glossary of the terms extracted from the translated text.

Characteristics of Reflux Episodes and Symptom Association in Patients With Erosive Esophagitis and Nonerosive Reflux Disease: Study Using Combined Impedance–pH Off Therapy

We sought to compare reflux and symptom association patterns in patients with nonerosive reflux disease (NERD), erosive esophagitis (EE), and in healthy volunteers (HVs).

NCX-1000, a nitric oxide-releasing derivative of UDCA, does not decrease portal pressure in patients with cirrhosis: results of a randomized, double-blind, dose-escalating study

NCX-1000 (2(acetyloxy) benzoic acid-3(nitrooxymethyl)phenyl ester) is an nitric oxide (NO)-releasing derivative of ursodeoxycholic acid (UDCA), which showed selective vasodilatory effect on intrahepatic circulation in animal models of cirrhosis. This study was aimed at testing the efficacy and tolerability of this compound in patients with cirrhosis and portal hypertension.

Changing patterns of cancer incidence in the early- and late-HAART periods: the Swiss HIV Cohort Study

The advent of highly active antiretroviral therapy (HAART) in 1996 led to a decrease in the incidence of Kaposi's sarcoma (KS) and non-Hodgkin's lymphoma (NHL), but not of other cancers, among people with HIV or AIDS (PWHA). It also led to marked increases in their life expectancy.

Primary tumors of the submandibular glands: a retrospective study based on 41 cases

We report our experience on the diagnostic approach, treatment, and follow-up of primary submandibular gland tumors. Retrospective review. Tertiary referral center. Forty-one adult patients, 22 male and 19 female, with primary submandibular gland tumors, 20 benign and 21 malignant. Age, gender, clinical findings, cyto- and histopathology, treatment and outcome were analyzed. Most tumors presented as a painless submandibular mass. Thirty three patients underwent a fine needle aspiration, the sensitivity, specificity and accuracy of which--in detecting malignant tumors--were 79%, 100% and 88%, respectively. Preoperative radiological imaging was performed in 30 cases. Patients with benign tumors were treated with surgery. Most malignant tumors were treated with a combined modality, including neck dissection and radiation therapy. Five patients developed a postoperative complication. Recurrent disease was encountered in 5 malignant tumors. The 2, 5 and 10 year disease-specific survival of patients with malignancy were 84%, 75% and 41%, respectively. The preoperative assessment of the nature of submandibular gland tumors remains challenging. Aggressive treatment of patients with malignant disease may help to avoid poor prognosis.

Comparison of immortalized bEnd5 and primary mouse brain microvascular endothelial cells as in vitro blood-brain barrier models for the study of T cell extravasation

Important insights into the molecular mechanism of T cell extravasation across the blood-brain barrier (BBB) have already been obtained using immortalized mouse brain endothelioma cell lines (bEnd). However, compared with bEnd, primary brain endothelial cells have been shown to establish better barrier characteristics, including complex tight junctions and low permeability. In this study, we asked whether bEnd5 and primary mouse brain microvascular endothelial cells (pMBMECs) were equally suited as in vitro models with which to study the cellular and molecular mechanisms of T cell extravasation across the BBB. We found that both in vitro BBB models equally supported both T cell adhesion under static and physiologic flow conditions, and T cell crawling on the endothelial surface against the direction of flow. In contrast, distances of T cell crawling on pMBMECs were strikingly longer than on bEnd5, whereas diapedesis of T cells across pMBMECs was dramatically reduced compared with bEnd5. Thus, both in vitro BBB models are suited to study T cell adhesion. However, because pMBMECs better reflect endothelial BBB specialization in vivo, we propose that more reliable information about the cellular and molecular mechanisms of T cell diapedesis across the BBB can be attained using pMBMECs.

Genome-wide association study of intracranial aneurysm identifies three new risk loci

Saccular intracranial aneurysms are balloon-like dilations of the intracranial arterial wall; their hemorrhage commonly results in severe neurologic impairment and death. We report a second genome-wide association study with discovery and replication cohorts from Europe and Japan comprising 5,891 cases and 14,181 controls with approximately 832,000 genotyped and imputed SNPs across discovery cohorts. We identified three new loci showing strong evidence for association with intracranial aneurysms in the combined dataset, including intervals near RBBP8 on 18q11.2 (odds ratio (OR) = 1.22, P = 1.1 x 10(-12)), STARD13-KL on 13q13.1 (OR = 1.20, P = 2.5 x 10(-9)) and a gene-rich region on 10q24.32 (OR = 1.29, P = 1.2 x 10(-9)). We also confirmed prior associations near SOX17 (8q11.23-q12.1; OR = 1.28, P = 1.3 x 10(-12)) and CDKN2A-CDKN2B (9p21.3; OR = 1.31, P = 1.5 x 10(-22)). It is noteworthy that several putative risk genes play a role in cell-cycle progression, potentially affecting the proliferation and senescence of progenitor-cell populations that are responsible for vascular formation and repair.

Genome-wide association study identifies new HLA class II haplotypes strongly protective against narcolepsy

Narcolepsy is a rare sleep disorder with the strongest human leukocyte antigen (HLA) association ever reported. Since the associated HLA-DRB1*1501-DQB1*0602 haplotype is common in the general population (15-25%), it has been suggested that it is almost necessary but not sufficient for developing narcolepsy. To further define the genetic basis of narcolepsy risk, we performed a genome-wide association study (GWAS) in 562 European individuals with narcolepsy (cases) and 702 ethnically matched controls, with independent replication in 370 cases and 495 controls, all heterozygous for DRB1*1501-DQB1*0602. We found association with a protective variant near HLA-DQA2 (rs2858884; P < 3 x 10(-8)). Further analysis revealed that rs2858884 is strongly linked to DRB1*03-DQB1*02 (P < 4 x 10(-43)) and DRB1*1301-DQB1*0603 (P < 3 x 10(-7)). Cases almost never carried a trans DRB1*1301-DQB1*0603 haplotype (odds ratio = 0.02; P < 6 x 10(-14)). This unexpected protective HLA haplotype suggests a virtually causal involvement of the HLA region in narcolepsy susceptibility.

The Politics of Accountability and Teacher Preparation: A Case Study from Pennsylvania

In an effort to understand some of the ways that accountability-based reform efforts have influenced teacher education, this article details the politics of accountability in Pennsylvania that motivated sweeping changes in the policies governing teacher preparation in 2006. This case study provides a poignant example of the kind of complex accountability systems now being constructed across the United States in an effort to change teacher preparation. By analyzing primary documents including the legal statutes governing teacher preparation in Pennsylvania, correspondence from the Pennsylvania Department of Education, related newsletters, memos, reports, transcripts of meetings, and testimony before the Pennsylvania House of Representatives, the complex nature of the conflicts underlying the development and implementation of teacher education reform is brought into focus. The study's findings suggest that a deep and uncritical acceptance of accountability-based teacher education reform on the part of educational policy makers is likely to do more harm than good. The article concludes by outlining a framework for developing more intelligent measures of accountability that might preserve professional autonomy and judgment.

Demonstration of epitope-spreading phenomena in bullous pemphigoid: results of a prospective multicenter study

Bullous pemphigoid (BP), the most common autoimmune subepidermal bullous disease, is associated with an autoantibody response to BP180 and BP230, two components of junctional adhesion complexes in human skin promoting dermo-epidermal cohesion. Retrospective analyses demonstrated that these autoantigens harbor several epitopes targeted by autoaggressive B and T cells. The aim of this prospective multicenter study was to assess the evolution of IgG autoantibodies in 35 BP patients over a 12-month observation period. Epitope-spreading (ES) events were detected in 17 of 35 BP patients (49%). They preferentially occurred in an early stage of the disease and were significantly related to disease severity at diagnosis. Moreover, in three patients, spreading of IgG reactivity to intracellular epitopes of BP180 and BP230 was preceded by recognition of the BP180 ectodomain. Finally, IgG reactivity with extracellular epitopes of BP180 and intracellular epitopes of BP230 correlated with the severity of BP in disease course. These findings support the idea that IgG recognition of the BP180 ectodomain is an early and crucial event in BP disease, followed by variable intra- and intermolecular ES events, which likely shape the individual course of BP.

Lung cancer in the Swiss HIV Cohort Study: role of smoking, immunodeficiency and pulmonary infection

Immunodeficiency and AIDS-related pulmonary infections have been suggested as independent causes of lung cancer among HIV-infected persons, in addition to smoking.

Experimental subarachnoid hemorrhage causes early and long-lasting microarterial constriction and microthrombosis: an in-vivo microscopy study

Early brain injury (EBI) after subarachnoid hemorrhage (SAH) is characterized by a severe, cerebral perfusion pressure (CPP)-independent reduction in cerebral blood flow suggesting alterations on the level of cerebral microvessels. Therefore, we aimed to use in-vivo imaging to investigate the cerebral microcirculation after experimental SAH. Subarachnoid hemorrhage was induced in C57/BL6 mice by endovascular perforation. Pial arterioles and venules (10 to 80 μm diameter) were examined using in-vivo fluorescence microscopy, 3, 6, and 72 hours after SAH. Venular diameter or flow was not affected by SAH, while >70% of arterioles constricted by 22% to 33% up to 3 days after hemorrhage (P<0.05 versus sham). The smaller the investigated arterioles, the more pronounced the constriction (r(2)=0.92, P<0.04). Approximately 30% of constricted arterioles were occluded by microthrombi and the frequency of arteriolar microthrombosis correlated with the degree of constriction (r(2)=0.93, P<0.03). The current study demonstrates that SAH induces microarterial constrictions and microthrombosis in vivo. These findings may explain the early CPP-independent decrease in cerebral blood flow after SAH and may therefore serve as novel targets for the treatment of early perfusion deficits after SAH.