CHEMICAL BONDING IN METAL-ORGANIC SYSTEMS: NATURE, STRUCTURES AND PROPERTIES

The main purpose of my thesis is the application of theoretical and experimental methods for the study of the nature of the chemical bond and its effect on structures and properties in organome-tallic systems, like Metal Carbonyl Clusters and Coordination Polymers (CPs) featuring, in some of the cases under study, intrinsic porosity (in the following, PCP for Porous Coordination Polymers or MOFs for Metal-Organic Frameworks). Concerning metal clusters, we worked on high nuclearity metal carbonyl clusters, and, particularly, on those featuring semi-interstitial atoms. The chemical bonding and the related properties in these peculiar class of molecules are still a matter of discussion in the scientific community. Concerning the class of Metal-organic Frameworks, we focused our attention on azolate-based ligands as building blocks for the synthesis of MOFs, looking at their possible future application as ultra-low dielectric constant materials in electronic devices. Finally, we investigated the structural behavior of Coordination Polymers at non-ambient condition (high pressure, in the order of 0-8 GPa), to induce new interactions and attitudes like electric conductivity. This research required the application of a bunch of theoretical tools, assisted by accurate single crystal X-ray diffraction experiments in standard and not-standard conditions (low temperature and high pressure). Moreover, a protocol for comparing different energy decomposition methods was developed and successfully applied to investigate the bonding nature in simple and complex systems

Antimicrobial Activity of Diffusible and Volatile Metabolites Emitted by Beauveria bassiana: Chemical Profile of Volatile Organic Compounds (VOCs) Using SPME-GC/MS Analysis

: The genus Beauveria includes important entomopathogenic and endophytic fungi; among them, Beauveria bassiana is the most studied species. However, there is little knowledge regarding their antimicrobial activity. The current research has been conducted to evaluate the in vitro antagonistic activity of B. bassiana and the antimicrobial efficacy of its Exo and Endo metabolites against Bacillus cereus, B. megaterium, Clavibacter michiganensis (Gram positive bacteria, G+ve), Xanthomonas campestris, Pseudomonas aeruginosa and P. fluorescence (Gram negative bacteria, G-ve). In addition, solid-phase microextraction (SPME) was coupled with Gas Chromatography-Mass Spectrometry (GC/MS) to qualitatively measure the volatile organic compounds' (VOCs) metabolic profile of the most efficient studied isolate of B. bassiana. The obtained results showed that the isolate UniB2439-3 has a promising antibacterial effect against most of the studied target bacteria. An SPME-GC/MS analysis of VOCs revealed the presence of ethanol, butanal,2-methyl, 2,4-dimethyl-1-heptene, octane, 4-methyl and β-elemene as the dominant bioactive compounds. The results demonstrated that the efficient isolate of B. bassiana can be potentially used as a biocontrol agent against several bacteria, especially G+ve ones

Calcium/calmodulin-dependent protein kinase kinase 2 regulates macrophage-mediated inflammatory responses.

Calcium/calmodulin-dependent kinase kinase 2 (CaMKK2) plays a key role in regulating food intake and energy expenditure at least in part by its actions in hypothalamic neurons. Previously, we showed that loss of CaMKK2 protected mice from high-fat diet (HFD)-induced obesity and glucose intolerance. However, although pair feeding HFD to WT mice to match food consumption of CAMKK2-null mice slowed weight gain, it failed to protect from glucose intolerance. Here we show that relative to WT mice, HFD-fed CaMKK2-null mice are protected from inflammation in adipose and remain glucose-tolerant. Moreover, loss of CaMKK2 also protected mice from endotoxin shock and fulminant hepatitis. We explored the expression of CaMKK2 in immune cells and found it to be restricted to those of the monocyte/macrophage lineage. CaMKK2-null macrophages exhibited a remarkable deficiency to spread, phagocytose bacteria, and synthesize cytokines in response to the Toll-like receptor 4 (TLR4) agonist lipopolysaccharide (LPS). Mechanistically, loss of CaMKK2 uncoupled the TLR4 cascade from activation of protein tyrosine kinase 2 (PYK2; also known as PTK2B). Our findings uncover an important function for CaMKK2 in mediating mechanisms that control the amplitude of macrophage inflammatory responses to excess nutrients or pathogen derivatives

Minimal Anomalous U(1)' Extension of the MSSM

We study an extension of the MSSM by an anomalous abelian vector multiplet and a St\"uckelberg multiplet. The anomalies are cancelled by the Green-Schwarz mechanism and the addition of Chern-Simons terms. The advantage of this choice over the standard one is that it allows for arbitrary values of the quantum numbers of the extra U(1). As a first step towards the study of hadron annihilations producing four leptons in the final state (a clean signal which might be studied at LHC) we then compute the decays Z'\to Z_0 \g and $Z'\to Z_0 Z_0$. We find that the largest values of the decay rate is $\sim 10^{-4}$ GeV, while the expected number of events per year at LHC is at most of the order of 10.Comment: 45 pages, 8 eps figures, feynmf. Phenomenological section expanded. 2 plots and references adde

The oxygen-assisted transformation of propane to COx/H2 through combined oxidation and WGS reactions catalyzed by vanadium oxide-based catalysts

This paper reports about the gas-phase oxidation of propane catalyzed by bulk vanadium oxide and by alumina- and silica-supported vanadium oxide. The reaction was studied with the aim of finding conditions at which the formation of H2 and CO2 is preferred over that of CO, H2O and of products of alkane partial oxidation. It was found that with bulk V2O5 considerable amounts of H2 are produced above 400 8C, the temperature at which the limiting reactant, oxygen, is totally consumed. The formation of H2 derived from the combination of: (i) oxidation reactions, with generation of CO, CO2, oxygenates (mainly acetic acid), propylene and H2O, all occurring in the fraction of catalytic bed that operated in the presence of gas-phase oxygen, and (ii) WGS reaction, propane dehydrogenation and coke formation, that instead occurred in the fraction of bed operating under anaerobic conditions. This combination of different reactions in a single catalytic bed was possible because of the reduction of V2O5 to V2O3 at high temperature, in the absence of gas-phase oxygen. In fact, vanadium sesquioxide was found to be an effective catalyst for the WGS, while V2O5 was inactive in this reaction. The same combination of reactions was not possible when vanadium oxide was supported over high-surface area silica or alumina; this was attributed to the fact that in these catalysts vanadium was not reduced below the oxidation state V4+, even under reaction conditions leading to total oxygen conversion. In consequence, these catalysts produced less H2 than bulk vanadium oxide

Health economic assessment tools (HEAT) for walking and for cycling

Physical inactivity is a significant public health problem in most regions of the world, which is unlikely to be solved by classical health promotion approaches alone. The promotion of active transport (cycling and walking) for everyday physical activity is a win-win approach; it not only promotes health but can also lead to positive environmental effects, especially if cycling and walking replace short car trips. Cycling and walking can also be more readily integrated into people’s busy schedules than, for example, leisure-time exercise. These forms of physical activity are also more practicable for groups of the population for which sport is either not feasible because of physical limitations or is not an accessible leisure activity for economic, social or cultural reasons. There is a large potential for active travel in European urban transport, as many trips are short and would be amenable to being undertaken on foot or by bicycle. This, however, requires effective partnerships with the transport and urban planning sectors, whose policies are key driving forces in providing appropriate conditions for such behavioural changes to take place. This has been recognized by a number of international policy frameworks, such as the Action Plan for implementation of the European Strategy for the Prevention and Control of Noncommunicable Diseases 2012–2016, adopted by the WHO Regional Committee for Europe (1). The strategy identifies the promotion of active mobility as one of the supporting interventions endorsed by WHO Member States to address this highpriority topic in the European Region, as do other international policy frameworks such as the Toronto Charter for Physical Activity launched in May 2010 as a global call for action (2)

CaMKK2 Knockout Bone Marrow Cells Collected/Processed in Low Oxygen (Physioxia) Suggests CaMKK2 as a Hematopoietic Stem to Progenitor Differentiation Fate Determinant

Little is known about a regulatory role of CaMKK2 for hematopoietic stem (HSC) and progenitor (HPC) cell function. To assess this, we used Camkk2−/− and wild type (WT) control mouse bone marrow (BM) cells. BM cells were collected/processed and compared under hypoxia (3% oxygen; physioxia) vs. ambient air (~21% oxygen). Subjecting cells collected to ambient air, even for a few minutes, causes a stress that we termed Extra Physiological Shock/Stress (EPHOSS) that causes differentiation of HSCs and HPCs. We consider physioxia collection/processing a more relevant way to assess HSC/HPC numbers and function, as the cells remain in an oxygen tension closer physiologic conditions. Camkk2−/− cells collected/processed at 3% oxygen had positive and negative effects respectively on HSCs (by engraftment using competitive transplantation with congenic donor and competitor cells and lethally irradiated congenic recipient mice), and HPCs (by colony forming assays of CFU-GM, BFU-E, and CFU-GEMM) compared to WT cells processed in ambient air. Thus, with cells collected/processed under physioxia, and therefore never exposed and naïve to ambient air conditions, CaMKK2 not only appears to act as an HSC to HPC differentiation fate determinant, but as we found for other intracellular mediators, the Camkk−/− mouse BM cells were relatively resistant to effects of EPHOSS. This information is of potential use for modulation of WT BM HSCs and HPCs for future clinical advantage. Graphical Abstract: [Figure not available: see fulltext.]

The legacy of Corrado Gini in population studies

This volume contains 12 papers that range over many different research subjects, taking in many of the population questions that, directly or indirectly, absorbed Corrado Gini as demographer and social scientist over several decades. They vary from the analysis of the living conditions and behaviours of the growing foreign population (measurements and methods of analysis, socio-economic conditions and health, ethnic residential segregation, sex-ratio at birth), to studies on the homogamy of couples; from population theories (with reference to the cyclical theory of populations) to the modelling approach to estimating mortality in adult ages or estimating time transfers, by age and sex, related to informal child care and adult care; from historical studies that take up themes dear to Gini (such as the estimates of Italian military deaths in WWI), to the application of Gini’s classical measurements to studying significant phenomena today (transition to adulthood and leaving the parental home, health care, disabled persons and social integration). The subjects and measurements that appear here are not intended to exhaust the broad spectrum of Gini’s research work in the demographic and social field (nor could they), but they can make up a part of the intersection between his vast legacy and some interesting topics in current research, some of which were not even imaginable in the mid twentieth century. Looking at the many contributions that celebrated Gini in Treviso and thinking about his legacy, it seems possible to identify at least two typologies of approach, to be found in this issue of the journal, too. On the one hand, there are contributions that aim to retrieve and discuss themes, methodologies and measurements dealt with or used by Gini so as to evaluate their present relevance and importance in the current scholarly debate. On the other, there are contributions that deal with topics that are far from Gini’s work, as they study very recent phenomena, but actually, among other things, make use of methods and indicators devised by Gini that are now so much part of the common currency of methodology, so they don’t require explicit reference to their Author

Loss of beta-catenin triggers oxidative stress and impairs hematopoietic regeneration

Accidental or deliberate ionizing radiation exposure can be fatal due to widespread hematopoietic destruction. However, little is known about either the course of injury or the molecular pathways that regulate the subsequent regenerative response. Here we show that the Wnt signaling pathway is critically important for regeneration after radiation-induced injury. Using Wnt reporter mice, we show that radiation triggers activation of Wnt signaling in hematopoietic stem and progenitor cells. β-Catenin-deficient mice, which lack the ability to activate canonical Wnt signaling, exhibited impaired hematopoietic stem cell regeneration and bone marrow recovery after radiation. We found that, as part of the mechanism, hematopoietic stem cells lacking β-catenin fail to suppress the generation of reactive oxygen species and cannot resolve DNA double-strand breaks after radiation. Consistent with the impaired response to radiation, β-catenin-deficient mice are also unable to recover effectively after chemotherapy. Collectively, these data indicate that regenerative responses to distinct hematopoietic injuries share a genetic dependence on β-catenin and raise the possibility that modulation of Wnt signaling may be a path to improving bone marrow recovery after damage