Costruzione di uno scaffold vascolarizzato per la chirurgia ortopedica

Specific aims The aim is to improve the treatment of the bone losses at the metacarpal bones level (both diaphysis and epiphysis) combining microsurgery, tissue engineering and biomaterials, so to minimize the donor side morbidity and optimize healing and outcomes. Methods Pre-operative controlateral X-ray or 3-D CT to allow custom-made HA scaffolds. Cement as temporary spacer in acute lesion and monitoring of infective risks. Treatment of the bone loss recurring to pre-fabricated or custom-made HA scaffolds, adding platelet gel or growth factor OP1. Stable synthesis. Control group with auto/omografts. Outcome indices: % of bone-union; finger TAM, Kapandji, DASH score; NMR and Scintigraphy at 180 days for revascularisation and bio-substitution of the scaffold. Preliminary results The authors just treated 6 patients, 4 males and 2 females, with an average age of 38.5 yrs, affected by segmental bone losses at the hand and wrist, recurring to pre-fabricated not vascularised scaffolds. In all cases the synthesis was performed with angular stability plates and a stable synthesis achieved. All patients have been controlled at a mean follow-up of 10.5 months (from 2 to 16 ). In all case but one the bone-scaffold osteo-integration was achieved at an average of 38 days at the hand, and 46 days at the wrist. The outcome studies, according to the DASH score, finger TAM, and Kapandji, were good and excellent in 5 cases, poor in one.

TCAD approaches to multidimensional simulation of advanced semiconductor devices

Technology scaling increasingly emphasizes complexity and non-ideality of the electrical behavior of semiconductor devices and boosts interest on alternatives to the conventional planar MOSFET architecture. TCAD simulation tools are fundamental to the analysis and development of new technology generations. However, the increasing device complexity is reflected in an augmented dimensionality of the problems to be solved. The trade-off between accuracy and computational cost of the simulation is especially influenced by domain discretization: mesh generation is therefore one of the most critical steps and automatic approaches are sought. Moreover, the problem size is further increased by process variations, calling for a statistical representation of the single device through an ensemble of microscopically different instances. The aim of this thesis is to present multi-disciplinary approaches to handle this increasing problem dimensionality in a numerical simulation perspective. The topic of mesh generation is tackled by presenting a new Wavelet-based Adaptive Method (WAM) for the automatic refinement of 2D and 3D domain discretizations. Multiresolution techniques and efficient signal processing algorithms are exploited to increase grid resolution in the domain regions where relevant physical phenomena take place. Moreover, the grid is dynamically adapted to follow solution changes produced by bias variations and quality criteria are imposed on the produced meshes. The further dimensionality increase due to variability in extremely scaled devices is considered with reference to two increasingly critical phenomena, namely line-edge roughness (LER) and random dopant fluctuations (RD). The impact of such phenomena on FinFET devices, which represent a promising alternative to planar CMOS technology, is estimated through 2D and 3D TCAD simulations and statistical tools, taking into account matching performance of single devices as well as basic circuit blocks such as SRAMs. Several process options are compared, including resist- and spacer-defined fin patterning as well as different doping profile definitions. Combining statistical simulations with experimental data, potentialities and shortcomings of the FinFET architecture are analyzed and useful design guidelines are provided, which boost feasibility of this technology for mainstream applications in sub-45 nm generation integrated circuits.

Sistemi liquido cristallini complessi: simulazioni al calcolatore e studi ESR

The aim of this PhD thesis was to study at a microscopic level different liquid crystal (LC) systems, in order to determine their physical properties, resorting to two distinct methodologies, one involving computer simulations, and the other spectroscopic techniques, in particular electron spin resonance (ESR) spectroscopy. By means of the computer simulation approach we tried to demonstrate this tool effectiveness for calculating anisotropic static properties of a LC material, as well as for predicting its behaviour and features. This required the development and adoption of suitable molecular models based on a convenient intermolecular potentials reflecting the essential molecular features of the investigated system. In particular, concerning the simulation approach, we have set up models for discotic liquid crystal dimers and we have studied, by means of Monte Carlo simulations, their phase behaviour and self­-assembling properties, with respect to the simple monomer case. Each discotic dimer is described by two oblate Gay­Berne ellipsoids connected by a flexible spacer, modelled by a harmonic "spring" of three different lengths. In particular we investigated the effects of dimerization on the transition temperatures, as well as on the characteristics of molecular aggregation displayed and the relative orientational order. Moving to the experimental results, among the many experimental techniques that are typically employed to evaluate LC system distinctive features, ESR has proved to be a powerful tool in microscopic scale investigation of the properties, structure, order and dynamics of these materials. We have taken advantage of the high sensitivity of the ESR spin probe technique to investigate increasingly complex LC systems ranging from devices constituted by a polymer matrix in which LC molecules are confined in shape of nano- droplets, as well as biaxial liquid crystalline elastomers, and dimers whose monomeric units or lateral groups are constituted by rod-like mesogens (11BCB). Reflection-mode holographic-polymer dispersed liquid crystals (H-PDLCs) are devices in which LCs are confined into nanosized (50­-300 nm) droplets, arranged in layers which alternate with polymer layers, forming a diffraction grating. We have determined the configuration of the LC local director and we have derived a model of the nanodroplet organization inside the layers. Resorting also to additional information on the nanodroplet size and shape distribution provided by SEM images of the H-PDLC cross-section, the observed director configuration has been modeled as a bidimensional distribution of elongated nanodroplets whose long axis is, on the average, parallel to the layers and whose internal director configuration is a uniaxial quasi- monodomain aligned along the nanodroplet long axis. The results suggest that the molecular organization is dictated mainly by the confinement, explaining, at least in part, the need for switching voltages significantly higher and the observed faster turn-off times in H-PDLCs compared to standard PDLC devices. Liquid crystal elastomers consist in cross-linked polymers, in which mesogens represent the monomers constituting the main chain or the laterally attached side groups. They bring together three important aspects: orientational order in amorphous soft materials, responsive molecular shape and quenched topological constraints. In biaxial nematic liquid crystalline elastomers (BLCEs), two orthogonal directions, rather than the one of normal uniaxial nematic, can be controlled, greatly enhancing their potential value for applications as novel actuators. Two versions of a side-chain BLCEs were characterized: side­-on and end­-on. Many tests have been carried out on both types of LCE, the main features detected being the lack of a significant dynamical behaviour, together with a strong permanent alignment along the principal director, and the confirmation of the transition temperatures already determined by DSC measurements. The end­-on sample demonstrates a less hindered rotation of the side group mesogenic units and a greater freedom of alignment to the magnetic field, as already shown by previous NMR studies. Biaxial nematic ESR static spectra were also obtained on the basis of Molecular Dynamics generated biaxial configurations, to be compared to the experimentally determined ones, as a mean to establish a possible relation between biaxiality and the spectral features. This provides a concrete example of the advantages of combining the computer simulation and spectroscopic approaches. Finally, the dimer α,ω-bis(4'-cyanobiphenyl-4-yl)undecane (11BCB), synthesized in the "quest" for the biaxial nematic phase has been analysed. Its importance lies in the dimer significance as building blocks in the development of new materials to be employed in innovative technological applications, such as faster switching displays, resorting to the easier aligning ability of the secondary director in biaxial phases. A preliminary series of tests were performed revealing the population of mesogenic molecules as divided into two groups: one of elongated straightened conformers sharing a common director, and one of bent molecules, which display no order, being equally distributed in the three dimensions. Employing this model, the calculated values show a consistent trend, confirming at the same time the transition temperatures indicated by the DSC measurements, together with rotational diffusion tensor values that follow closely those of the constituting monomer 5CB.

Mediterranean brachiopods: morphological, ecological and phylogenetic aspects

The Brachiopoda of the Marine Protected Area “Secche di Tor Paterno”, Central Tyrrhenian Sea, have been investigated in order to give a first glance of the diversity of the brachiopods of this area and provide a new report on the Mediterranean Brachiopod fauna. Four species were reported: Novocrania anomala (Müller, 1776), Megathiris detruncata (Gmelin, 1790), Joania cordata (Risso,1826) and Argyrotheca cuneata (Risso,1826). For all the four species a morphological analysis was carried out. For the two most abundant species, J.cordata and A. cuneata, a morphometric study, based on thickness/width and length/width scattergrams, was carried out, in order to investigate their variability. Size-frequency distributions relative to the three dimensions of the shell were also computed, aimed at a evaluation of population dynamics of these two species. The results showed that, for both species, the parameters which most determine the rise of the shell during the growth of animal are width and length and that frequency distributions are mainly bi- or plurymodal and that they are difficult to interpret, as reported by other studies. Analysis of drill holes found on the shell of some specimens of the two same species revealed a predatory origin and that three different predators are responsible for them. Partial sequences of two different genetic markers, the Internal Transcribed Spacer 1 (ITS1) and the cytochrome oxidase subunit 1 (COI), were used to investigate the phylogenetic relationship between two populations of the eurybathic brachiopod species Gryphus vitreus (Born,1778) across the strait of Gibraltar. This represents the first genetic population study on brachiopods. Results from AMOVA and Bayesian analysis performed on 31 specimens highlighted no genetic differentiation indicating a likely panmixia, dispite the lecitotrophic development of the species.

Small Molecules as Modulators of Different Targets Involved in Tumor Progression

Tumor is a lesion that may be formed by an abnormal growth of neoplastic cells. Many factors increase the risk of cancer and different targets are involved in tumor progression. Within this thesis, we have addressed two different biological targets, independently connected with tumor formation, e.g. Hsp90 and androgen receptor. The ATP-dependent chaperone Hsp90 is responsible for the conformational maturation and the renaturation of proteins. “Client” proteins are associated with the cancer hallmarks, as cell proliferation and tumor progression. Consequently, Hsp90 has evolved into promising anticancer target. Over the past decade, radicicol has been identified as potential anticancer agent targeting Hsp90, but it is not active in vivo. With that aim of obtaining radicicol-related derivatives, we developed the design and synthesis of new chalcones analogs. Chalcones, which are abundant in edible plants, own a diverse array of pharmacological activities and are considered a versatile scaffold for drug design. Antiproliferative assays and western blot analysis on the new compounds showed that some of those display an interesting cytotoxic effect and the ability to modulate Hsp90 client proteins expression. Androgen Receptor (AR) hypersensitivity plays crucial role in prostate cancer, which progression is stimulated by androgens. The therapy consists in a combination of surgical or chemical castration, along with antiandrogens treatment. Casodex® (bicalutamide), is the most widespread antiandrogen used in clinic. However, hormonal therapy is time-limited since many patients develop resistance. Commercially available antiandrogens show a common scaffold, e.g. two substituted aromatic rings linked by a linear or a cyclic spacer. With the aim of obtaining novel pure AR antagonists, we developed a new synthetic methodology, which allowed us to introduce, as linker between two suitably chosen aromatic rings, a triazole moiety. Preliminary data suggest that the herein reported new molecules generally decrease PSA expression, thus confirming their potential AR antagonistic activity.

Trascriptome analysis and functional genomics of Neisseria meningitidis in human blood

Neisseria meningitidis (Nm) is the major cause of septicemia and meningococcal meningitis. During the course of infection, it must adapt to different host environments as a crucial factor for survival. Despite the severity of meningococcal sepsis, little is known about how Nm adapts to permit survival and growth in human blood. A previous time-course transcriptome analysis, using an ex vivo model of human whole blood infection, showed that Nm alters the expression of nearly 30% of ORFs of the genome: major dynamic changes were observed in the expression of transcriptional regulators, transport and binding proteins, energy metabolism, and surface-exposed virulence factors. Starting from these data, mutagenesis studies of a subset of up-regulated genes were performed and the mutants were tested for the ability to survive in human whole blood; Nm mutant strains lacking the genes encoding NMB1483, NalP, Mip, NspA, Fur, TbpB, and LctP were sensitive to killing by human blood. Then, the analysis was extended to the whole Nm transcriptome in human blood, using a customized 60-mer oligonucleotide tiling microarray. The application of specifically developed software combined with this new tiling array allowed the identification of different types of regulated transcripts: small intergenic RNAs, antisense RNAs, 5’ and 3’ untranslated regions and operons. The expression of these RNA molecules was confirmed by 5’-3’RACE protocol and specific RT-PCR. Here we describe the complete transcriptome of Nm during incubation in human blood; we were able to identify new proteins important for survival in human blood and also to identify additional roles of previously known virulence factors in aiding survival in blood. In addition the tiling array analysis demonstrated that Nm expresses a set of new transcripts, not previously identified, and suggests the presence of a circuit of regulatory RNA elements used by Nm to adapt to proliferate in human blood.

Characterization of optical transduction-based molecular systems and nanoparticles for the development of chemical sensors

With the increasing importance that nanotechnologies have in everyday life, it is not difficult to realize that also a single molecule, if properly designed, can be a device able to perform useful functions: such a chemical species is called chemosensor, that is a molecule of abiotic origin that signals the presence of matter or energy. Signal transduction is the mechanism by which an interaction of a sensor with an analyte yields a measurable form of energy. When dealing with the design of a chemosensor, we need to take into account a “communication requirement” between its three component: the receptor unit, responsible for the selective analyte binding, the spacer, which controls the geometry of the system and modulates the electronic interaction between the receptor and the signalling unit, whose physico-chemical properties change upon complexation. A luminescent chemosensor communicates a variation of the physico-chemical properties of the receptor unit with a luminescence output signal. This thesis work consists in the characterization of new molecular and nanoparticle-based system which can be used as sensitive materials for the construction of new optical transduction devices able to provide information about the concentration of analytes in solution. In particular two direction were taken. The first is to continue in the development of new chemosensors, that is the first step for the construction of reliable and efficient devices, and in particular the work will be focused on chemosensors for metal ions for biomedical and environmental applications. The second is to study more efficient and complex organized systems, such as derivatized silica nanoparticles. These system can potentially have higher sensitivity than molecular systems, and present many advantages, like the possibility to be ratiometric, higher Stokes shifts and lower signal-to-noise ratio.

Cultura materiale ed espansione di Roma: Il caso dell'Ager Gallicus

Lo scritto ha l’obiettivo di definire dinamiche e cronologie di quel complesso processo espansionistico che portò Roma alla conquista dei territori dell’Ager Gallicus, partendo dall’analisi dettagliata della cultura materiale e dei rispettivi contesti di provenienza emersi dalle recenti indagini archeologiche realizzate dal Dipartimento di Storia Culture Civiltà dell’Università degli Studi di Bologna nella città di Senigallia. In armonia con quanto testimoniato dalle sequenze stratigrafiche documentate, si delineano quattro principali fasi di vita dell’abitato: la prima preromana, la seconda riferibile alla prima fase di romanizzazione del sito, la terza inerente allo sviluppo dell’insediamento con la fondazione della colonia romana e l’ultima riferibile all’età repubblicana. Emerge con chiarezza la presenza già dalla fine del IV-inizio III a.C., di un insediamento romano nel territorio della città, sviluppatosi con la fondazione di un’area sacra e la predisposizione di un’area produttiva. La scelta del sito di Sena Gallica fu strategica: un territorio idoneo allo sfruttamento agricolo e utile come testa di ponte per la conquista dei territori del Nord Italia. Inoltre, questo centro aveva già intrecciato rapporti commerciali con gli insediamenti costieri adriatici e mediterranei. La presenza di ceramica di produzione locale, il rinvenimento di elementi distanziatori e le caratteristiche geomorfologiche del sito, fanno ipotizzare la presenza in loco di un’officina ceramica. Ciò risulta di grande importanza dato che tutte le attestazioni ceramiche prodotte localmente e rinvenute nel territorio, fino ad oggi sono attribuite alle officine di Aesis e Ariminum. Dunque Sena Gallica sarebbe stata un centro commerciale e produttivo. La precoce presenza di ceramica a Vernice Nera di tipo romano-laziale prodotte localmente prima dell’istituzione ufficiale della colonia, che permette di ipotizzare uno stanziamento di piccoli gruppi di Romani in territori appena conquistati ma non ancora colonizzati, attestata a Sena Gallica, trova riscontro anche in altri centri adriatici come Ariminum, Aesis, Pisaurum, Suasa e Cattolica.

Multifarious tumor-oriented small molecules: development of synthetic methodologies and application for diagnostic platforms

Cancer represents one of the most relevant and widespread diseases in the modern age. In this context, integrin receptors are important for the interactions of cells with extracellular matrix and for the development of both inflammation and carcinogenic phenomena. There are many tricks to improve the bioactivity and receptor selectivity of exogenous ligands; one of these is to integrate the amino acid sequence into a cyclic peptide to restrict its conformational space. Another approach is to develop small peptidomimetic molecules in order to enhance the molecular stability and open the way to versatile synthetic strategies. Starting from isoxazoline-based peptidomimetic molecules we recently reported, in this thesis we are going to present the synthesis of new integrin ligands obtained by modifying or introducing appendages on already reported structures. Initially, we are going to introduce the synthesis of linear and cyclic α-dehydro-β-amino acids as scaffolds for the preparation of bioactive peptidomimetics. Subsequently, we are going to present the construction of small molecule ligands (SMLs) based delivery systems performed starting from a polyfunctionalised isoxazoline scaffold, whose potency towards αVβ3 and α5β1 integrins has already been established by our research group. In the light of these results and due to the necessity to understand the behaviour of a single enantiomer of the isoxazoline-based compounds, the research group decided to synthesise the enantiopure heterocycle using a 1,3-dipolar cycloaddiction approach. Subsequently, we are going to introduce the synthesis of a Reporting Drug Delivery System composed by a carrier, a first spacer, a linker, a self-immolative system, a second spacer and a latent fluorophore. The last part of this work will describe the results obtained during the internship abroad in Prof. Aggarwal’s laboratory at the University of Bristol. The project was focused on the Mycapolyol A synthesis.

Percutaneous Cement Discoplasty: Biomechanical and clinical assessment of a minimally invasive treatment of lumbar intervertebral disc disease

With population ageing, spine diseases have an increasing prevalence and induce high economic and social costs. The development of minimally invasive surgeries allows reducing the surgery-associated risks in elderly and polymorbid patients, and save costs by treating more patients in shorter time and reducing the complications. Percutaneous Cement Discoplasty (PCD) is a minimally invasive technique developed to treat highly degenerated intervertebral discs exhibiting a vacuum phenomenon. Filling the disc with bone cement creates a stand-alone spacer which partially restores the disc height and re-opens the foraminal space. PCD has recently been introduced to clinical use. However, the spine biomechanics following this treatment remained unravelled. The aim of this PhD thesis is to bridge the clinical experience with in vitro methodologies, to provide a multilateral evaluation of PCD outcome and a better understanding of its impact on the spine biomechanics, and of its possible contraindications. Firstly, a suitable in vitro porcine model to test the biomechanics of discoplasty by comparing specimens in the preoperative and postoperative conditions was developed. The methodology was then applied to investigate the biomechanics of discoplasty in cadaveric human segments. The in vitro specimens were mechanically investigated in flexion and extension, while a DIC system quantified the range of motion, disc height, and strains on the disc surface. Then, a versatile tool to measure the impact of discoplasty on the foramen space was developed and applied both to clinical and experimental work. The vertebrae reconstructed from CT scans were registered to match the loading configuration, using ex vivo DIC measurements under loading. The foramen volumetric changes caused by PCD was measured using a 3D geometrical method clinically developed by the research group. In conclusion, this project significantly extended the understanding of PCD biomechanics, highlighting its benefits in the treatment of advanced cases of intervertebral disc degeneration.

Protostrongylids nematodes as a tool to study the biogeography of wild mammals

The European brown hare (Lepus europaeus Pallas, 1778) is an important game species, distributed across Europe and introduced in other regions. Recently, a geographically isolated population, closely related to an ancestral lineage of Lepus europaeus meridiei, was found on Pianosa Island, off the coast of Tuscany, Italy (Mengoni et al., 2018). Thus, the unique opportunity to explore the evolution and genetic structure of its helminth parasites was added to its exceptional isolation condition. Various lungworm species within the genus Protostrongylus (Nematoda: Protostrongylidae) are described in European brown hares. Our aim was to analyze the parasite population through morphological and molecular approaches in order to study the biogeography of the European brown hares (L. e. meridiei) population from Pianosa Island. Moreover, we investigated the morphology of a monospecific genus, i.e. Orthostrongylus, considering its quite intrigant descriptive history and its still unclear and debated classification. Nuclear and mitochondrial markers were used based on their resolution power and expected polymorphism; the whole Internal Transcribed Spacer 1 and 2 (ITS), including the 5.8S rRNA sequence and the Large Subunit (28S) were used, as nuclear genes, for confirmation of the species identification. Conversely, the cytochrome oxidase c subunit I (COI) was used, as mithocondrial genes, to assess interspecific genetic relationships. Molecular analysis corroborated the morphological identification since all the generated ITS and LSU sequences were 100% consistent with the species Protostrongylus oryctolagi and Orthostrongylus macrotis. The paucity of molecular data existent about this genus of parasites underlines the need for more insight’s studies. An in-depth analysis of broncho-pulmonary parasites and the host-parasites relationships along with the improvement of the use of mitochondrial genes, as well as the assessment of new polymorphic markers could contribute to an extensive understanding of parasites fauna and taxonomy, as well as their relationship with wild mammals’ hosts.

Ultra-hypofractionated stereotactic radiotherapy for prostate cancer in 5 fractions: current evidences and our clinical experience

AIMS: The present is a retrospective evaluation of acute genito-urinary (GU) and gastro-intestinal (GI) toxicity, in addition to biochemical recurrence rate in 57 prostate cancer patients treated at our Institution with ultra-hypofractionated RT (UHRT) schedule. METHODS: From January 2021 to December 2022 we have treated 57 patients with prostate cancer, using an UHRT scheme of 5-fractions every other day for a total dose delivered of 36.25 Gy, according to the PACE-B trial treatment schedule. Good urinary function, assessed by International Prostate Symptom Score (IPSS), were required. The simulation CT scans were acquired in supine position and fused with MRI for CTVs definition for every patient. Each treatment was performed by Accuray's TomoTherapy with daily IGRT. The evaluation of the set-up was very restrictive before daily treatment delivery. RESULTS: According to RTOG toxicity scale, the acute GU toxicity at 3 months from RT, GU toxicity was G0 for 30 patients (52.6%), G1 for 26 (45.6%) and G2 for one only (1.75%); rectal toxicity was G0 for 56 patients (98.25%) and G1 for one only (1.75%). The median follow-up (FU) was 9 months (2-24 months). In the following FU months, we observed progressively lower urinary and rectal toxicity, except for one patient who showed G2 GU toxicity at 12 months. All but one patient had a progressive PSA value decrease. CONCLUSIONS: In our experience, UHRT appears to be safe and well tolerated even without the use of rectal spacer devices. A longer FU is necessary to evaluate late toxicity and disease control rate.