“TECNICHE OTTICHE DI REVERSE ENGINEERING PER IL CONTROLLO DIMENSIONALE E DI FORMA DI SEGMENTI STATORICI”

THESIS TITLE “OPTICAL TECNIQUES OF REVERSE ENGINEERING IN DIMENSIONAL AND SHAPE CONTROL OF VANE SEGMENTS” ABSTRACT In this thesis is presented the development of a low-cost 3D Stereo-Vision Scanner, used in the Reverse Engineering inspection process and in the dimensional and shape verification (GD&T) on turbine vanes manufactured via casting. The non-contact system allows the digitalization in three-dimension of object surfaces by the projection of fringe patterns (black and white stripes), capturing the images of coded surface by structured light. The adopted technique is based on innovative concept of gray-code methodology to solve correspondences among the two digital cameras, by using structured light being through coded horizontal and vertical fringes. Furthermore, it is analyzed the possibility to introduce the techniques of R.E. by 3D Scanner between the steps that improve the performance of Quality Control in the computer aided design on turbine vanes of jet engine. In a particular way, a study of feasibility about the possibility to make dimensional and shape verification directly upon the digitized model (3D point clouds) by comparing to the Reference CAD model has been developed. The requirement of dimensional and shape controls by low-cost cutting-edge techniques is born as Avio S.p.A factory target to improve manufacture and to assure excellent quality and efficiency, to minimize a global costs. SOMMARIO In questa tesi viene descritto lo sviluppo di un sistema ottico stereoscopico a basso costo, utilizzato nel processo di ispezione tipico della Reverse Engineering e nel controllo dimensionale e di forma (GD&T) su componenti statorici di turbomacchine ottenuti per fusione. Il sistema consente di rilevare tridimensionalmente l’oggetto investito da frange parallele bianche e nere, acquisendo le immagini della superficie codificata con la luce strutturata. La tecnica impiegata usa una soluzione innovativa del metodo “gray-code” che consente di risolvere il problema delle corrispondenze, tipico dei dispositivi stereovisivi, utilizzando luce strutturata comprendente frange orizzontali e verticali codificate. È stata pertanto analizzata la possibilità di introdurre le tecniche di R.E. coadiuvate dallo Scanner 3D tra le fasi che concorrono all’ottimizzazione del controllo di qualità nella progettazione di segmenti statorici di turbina dei propulsori aeronautici. Nel dettaglio è stata eseguita una analisi di fattibilità sulla possibilità di realizzare controlli dimensionali e di forma direttamente sul modello digitale acquisito (nuvola di punti 3D), confrontandolo con la geometria CAD nominale. L’esigenza di controlli dimensionali e di forma con tecniche d’avanguardia a basso costo nasce dall’obiettivo della società Avio S.p.A. di ottimizzare il prodotto finale per garantirne la massima efficienza e qualità, minimizzando i costi globali

Toxicity testing in environmental monitoring: The role of enzymatic biosensors

Biological toxicity testing is a rapidly expanding field involving numerous bioanalytical techniques. The enzymatic biosensors are valuable screening tools to identify pollutants and/or toxic agents in the environment and/or in food matrices, thus representing a valid alternative to animal testing in analytical toxicology. Inhibition based biosensors here presented have been proved to represent alternative assays for the toxicity evaluation of warfare agents and endocrine disrupting chemicals as well as algal toxins (phycotoxins) in the contamined sea foods (mainly clams and other mollusks). Results obtained by inhibition studies performed by means of several enzymatic biosensors indicate the reliability of the proposed method and the possibility to extend such an experimental approach to other toxicants as a simple, rapid and cheap biotest, to be used easily also "on the spot"

Revisiting the Plasmodium falciparum RIFIN family: from comparative genomics to 3D-model prediction

<p>Abstract</p> <p>Background</p> <p>Subtelomeric <it>RIFIN </it>genes constitute the most abundant multigene family in <it>Plasmodium falciparum</it>. <it>RIFIN </it>products are targets for the human immune response and contribute to the antigenic variability of the parasite. They are transmembrane proteins grouped into two sub-families (RIF_A and RIF_B). Although recent data show that RIF_A and RIF_B have different sub-cellular localisations and possibly different functions, the same structural organisation has been proposed for members of the two sub-families. Despite recent advances, our knowledge of the regulation of <it>RIFIN </it>gene expression is still poor and the biological role of the protein products remain obscure.</p> <p>Results</p> <p>Comparative studies on <it>RIFINs </it>in three clones of <it>P. falciparum </it>(3D7, HB3 and Dd2) by Multidimensional scaling (MDS) showed that gene sequences evolve differently in the 5'upstream, coding, and 3'downstream regions, and suggested a possible role of highly conserved 3' downstream sequences. Despite the expected polymorphism, we found that the overall structure of <it>RIFIN </it>repertoires is conserved among clones suggesting a balance between genetic drift and homogenisation mechanisms which guarantees emergence of novel variants but preserves the functionality of genes. Protein sequences from a <it>bona fide </it>set of 3D7 RIFINs were submitted to predictors of secondary structure elements. In contrast with the previously proposed structural organisation, no signal peptide and only one transmembrane helix were predicted for the majority of RIF_As. Finally, we developed a strategy to obtain a reliable 3D-model for RIF_As. We generated 265 possible structures from 53 non-redundant sequences, from which clustering and quality assessments selected two models as the most representative for putative RIFIN protein structures.</p> <p>Conclusion</p> <p>First, comparative analyses of <it>RIFIN </it>repertoires in different clones of <it>P. falciparum </it>provide insights on evolutionary mechanisms shaping the multigene family. Secondly, we found that members of the two sub-families RIF_As and RIF_Bs have different structural organization in accordance with recent experimental results. Finally, representative models for RIF_As have an "Armadillo-like" fold which is known to promote protein-protein interactions in diverse contexts.</p

Atogepant for the Prevention of Episodic Migraine in Adults: A Systematic Review and Meta-Analysis of Efficacy and Safety.

INTRODUCTION The inhibition of the calcitonin gene-related peptide (CGRP) pathway has attracted interest in pharmacological research on migraine. Atogepant is a potent, selective, orally available antagonist of the CGRP receptor approved as a preventive treatment of episodic migraine. This systematic review with meta-analysis aims to evaluate the efficacy and safety of atogepant for the prevention of episodic migraine in adult patients. METHODS Randomized, placebo-controlled, single or double-blinded trials were identified through a systematic literature search (December week 4, 2021). Main outcomes included the changes from baseline in monthly migraine days and the incidence of adverse events (AEs) and treatment withdrawal due to AEs. Mean difference (MD) and risk ratio (RR) with 95% confidence intervals (95% CIs) were estimated. RESULTS Two trials were included, overall enrolling 1550 patients. A total of 408 participants were randomized to placebo, 314 to atogepant 10 mg, 411 to atogepant 30 mg, and 417 to atogepant 60 mg once daily. The mean age of the patients was 41.0 years and 87.7% were women. The reduction in the mean number of migraine days from baseline across the 12-week treatment period was significantly greater among patients treated with atogepant at either the daily dose of 10 mg (MD - 1.16, 95% CI - 1.60 to - 0.73, p < 0.001), 30 mg (MD - 1.15, 95% CI - 1.54 to - 0.76, p < 0.001), or 60 mg (MD - 1.20, 95% CI - 2.18 to - 0.22, p = 0.016) than with placebo. There were no differences in the occurrence of AEs and drug withdrawal due to AEs between atogepant and placebo groups. Constipation was more commonly observed in patients treated with atogepant at 30 mg/day than placebo (RR 5.19, 95% CI 2.00-13.46; p = 0.001). Treatment with atogepant at the daily dose of 60 mg was associated with a higher risk of constipation (RR 4.92, 95% CI 1.89-12.79; p = 0.001) and nausea (RR 2.73, 95% CI 1.47-5.06; p = 0.001) than placebo. CONCLUSION Atogepant is an efficacious and overall well-tolerated treatment for the prevention of episodic migraine in adults

Gametocytes of the Malaria Parasite Plasmodium falciparum Interact With and Stimulate Bone Marrow Mesenchymal Cells to Secrete Angiogenetic Factors

The gametocytes of Plasmodium falciparum, responsible for the transmission of this malaria parasite from humans to mosquitoes, accumulate and mature preferentially in the human bone marrow. In the 10 day long sexual development of P. falciparum, the immature gametocytes reach and localize in the extravascular compartment of this organ, in contact with several bone marrow stroma cell types, prior to traversing the endothelial lining and re-entering in circulation at maturity. To investigate the host parasite interplay underlying this still obscure process, we developed an in vitro tridimensional co-culture system in a Matrigel scaffold with P. falciparum gametocytes and self-assembling spheroids of human bone marrow mesenchymal cells (hBM-MSCs). Here we show that this co-culture system sustains the full maturation of the gametocytes and that the immature, but not the mature, gametocytes adhere to hBM-MSCs via trypsin-sensitive parasite ligands exposed on the erythrocyte surface. Analysis of a time course of gametocytogenesis in the co-culture system revealed that gametocyte maturation is accompanied by the parasite induced stimulation of hBM-MSCs to secrete a panel of 14 cytokines and growth factors, 13 of which have been described to play a role in angiogenesis. Functional in vitro assays on human bone marrow endothelial cells showed that supernatants from the gametocyte mesenchymal cell co-culture system enhance ability of endothelial cells to form vascular tubes. These results altogether suggest that the interplay between immature gametocytes and hBM-MSCs may induce functional and structural alterations in the endothelial lining of the human bone marrow hosting the P. falciparum transmission stages

Cannabidiol efficacy and clobazam status: A systematic review and meta-analysis.

OBJECTIVE To evaluate the potential impact of concomitant clobazam (CLB) use on the efficacy of cannabidiol (CBD) treatment in patients with Dravet syndrome and Lennox-Gastaut syndrome using meta-analytical techniques. METHODS We searched for randomized, placebo-controlled, single- or double-blinded trials. The proportion of patients who achieved ≥50% reduction from baseline in seizure frequency during the treatment period was assessed according to CLB status. Risk ratios (RRs) with 95% confidence intervals (CIs) were estimated. RESULTS Four trials were included and enrolled 714 participants, 429 for the add-on CBD group and 285 for the add-on placebo group. Among CBD-treated patients, 240 (55.9%) were taking concomitant CLB (CLB-On) and 189 (44.1%) were not taking concomitant CLB (CLB-Off); in placebo-treated patients, 158 (55.4%) were CLB-On and 127 (44.6%) CLB-Off. The percentages of patients who had at least 50% reduction in seizure frequency during the treatment period were 29.1% in the CBD arm and 15.7% in the placebo group among CLB-Off patients (RR = 1.80, 95% CI = 1.12-2.90, P = .015). Among CBL-On patients, the ≥50% reduction in seizure frequency was found in 52.9% and 27.8% in the CBD and placebo groups, respectively (RR = 1.85, 95% CI = 1.40-2.44, P < .001). SIGNIFICANCE CBD was associated with a higher rate of seizure response in comparison to placebo when added to the existing antiepileptic regimen both in patients taking and in those not taking concomitant CLB. The lack of randomization for CLB status and the limited sample size need to be considered in the interpretation of the findings

Zoledronic acid increases docetaxel cytotoxicity through pMEK and Mcl-1 inhibition in a hormone-sensitive prostate carcinoma cell line

<p>Abstract</p> <p>Background</p> <p>In prostate cancer, the identification of drug combinations that could reduce the tumor cell population and rapidly eradicate hormone-resistant cells potentially present would be a remarkable breakthrough in the treatment of this disease.</p> <p>Methods</p> <p>The study was performed on a hormone-sensitive prostate cancer cell line (LNCaP) grown in normal or hormone-deprived charcoal-stripped (c.s.) medium. Cell viability and apoptosis were assessed by SRB assay and Annexin-V/TUNEL assays, respectively. Activated caspase-3, p21, pMEK and MCL-1 expression levels were detected by western blotting.</p> <p>Results</p> <p>The simultaneous exposure of zoledronic acid [100 μM] and docetaxel [0.01 μM] for 1 h followed by treatment with zoledronic acid for 72, 96 or 120 h produced a high synergistic interaction (R index = 5.1) with a strong decrease in cell viability. This cytotoxic effect was associated with a high induction of apoptosis in both LNCaP and in c.s. LNCaP cells. The induction of apoptosis was paralleled by a decrease in pMEK and Mcl-1 expression.</p> <p>Conclusion</p> <p>The zoledronic acid-docetaxel combination produced a highly significant synergistic effect on the LNCaP cell line grown in normal or hormone-deprived medium, the principal molecular mechanisms involved being apoptosis and decreased pMEK and Mcl-1 expression. This experimentally derived schedule would seem to prevent the selection and amplification of hormone-resistant cell clones and could thus be potentially used alongside standard androgen deprivation therapy in the management of hormone-sensitive prostate carcinoma.</p

Nitrite reductase from Pseudomonas aeruginosa: Sequence of the gene and the protein

AbstractThe gene coding for nitrite reductase of Pseudomonas aeruginosa has been cloned and its sequence determined. The coding region is 1707 bp long and contains information for a polypeptide chain of 568 amino acids. The sequence of the mature protein has been confirmed independently by extensive amino acid sequencing. The amino-terminus of the mature protein is located at Lys-26; the preceding 25 residue long extension shows the features typical of signal peptides. Therefore the enzyme is probably secreted into the periplasmic space. The mature protein is made of 543 amino acid residues and has a molecular mass of 60204 Da. The c-heme-binding domain, which contains the only two Cys of the molecule, is located at the amino-terminal region. Analysis of the protein sequence in terms of hydrophobicity profile gives results consistent with the fact that the enzyme is fully water soluble and not membrane bound; the most hydrophilic region appears to correspond to the c-heme domain. Secondary structure predictions are in general agreement with previous analysis of circular dichroic data

A genomic glimpse of aminoacyl-tRNA synthetases in malaria parasite Plasmodium falciparum

<p>Abstract</p> <p>Background</p> <p><it>Plasmodium </it>parasites are causative agents of malaria which affects >500 million people and claims ~2 million lives annually. The completion of <it>Plasmodium </it>genome sequencing and availability of PlasmoDB database has provided a platform for systematic study of parasite genome. Aminoacyl-tRNA synthetases (<it>aaRS</it>s) are pivotal enzymes for protein translation and other vital cellular processes. We report an extensive analysis of the <it>Plasmodium falciparum </it>genome to identify and classify <it>aaRSs </it>in this organism.</p> <p>Results</p> <p>Using various computational and bioinformatics tools, we have identified 37 <it>aaRS</it>s in <it>P. falciparum</it>. Our key observations are: (i) fraction of proteome dedicated to <it>aaRS</it>s in <it>P. falciparum </it>is very high compared to many other organisms; (ii) 23 out of 37 <it>Pf-aaRS </it>sequences contain signal peptides possibly directing them to different cellular organelles; (iii) expression profiles of <it>Pf-aaRSs </it>vary considerably at various life cycle stages of the parasite; (iv) several <it>PfaaRSs </it>posses very unusual domain architectures; (v) phylogenetic analyses reveal evolutionary relatedness of several parasite <it>aaRS</it>s to bacterial and plants <it>aaRSs</it>; (vi) three dimensional structural modelling has provided insights which could be exploited in inhibitor discovery against parasite <it>aaRSs</it>.</p> <p>Conclusion</p> <p>We have identified 37 <it>Pf-aaRSs </it>based on our bioinformatics analysis. Our data reveal several unique attributes in this protein family. We have annotated all 37 <it>Pf-aaRSs </it>based on predicted localization, phylogenetics, domain architectures and their overall protein expression profiles. The sets of distinct features elaborated in this work will provide a platform for experimental dissection of this family of enzymes, possibly for the discovery of novel drugs against malaria.</p

Eslicarbazepine acetate in the treatment of adults with partial-onset epilepsy: an evidence-based review of efficacy, safety and place in therapy

Introduction: Up to 30% of the patients diagnosed with epilepsy will continue suffering from seizures despite treatment with antiepileptic drugs, either in monotherapy or polytherapy. Hence, there remains the need to develop new effective and well-tolerated therapies. Aim: The objective of this article was to review the evidence for the efficacy and safety of eslicarbazepine acetate (ESL) as adjunctive treatment in adult patients with focal onset seizures. Evidence review: ESL is the newest, third-generation, single enantiomer member of the dibenzazepine family. Following oral administration, ESL is rapidly and extensively metabolized by hepatic first-pass hydrolysis to the active metabolite eslicarbazepine, which has linear, dose-proportional pharmacokinetics and low potential for drug-drug interactions. Eslicarbazepine works as a competitive blocker of the voltage gated sodium channels; unlike carbamazepine (CBZ) and oxcarbazepine (OXC), it has a lower affinity for the resting state of the channels, and reduces their availability by selectively enhancing slow inactivation. Efficacy and safety of ESL have been assessed in four randomized, Phase III clinical trials: the median relative reduction in standardized seizure frequency was 33.4% and 37.8% in the ESL 800 and 1,200 mg daily dose groups, and the responder rates were 33.8% and 43.1%, respectively. The incidence of treatment-emergent adverse events (TEAEs) increased with raising the dosage (ESL 400 mg: 63.8%, ESL 800 mg: 67.0%, ESL 1,200 mg: 73.1%). The TEAEs were generally mild to moderate in intensity, and the most common were dizziness, somnolence, headache and nausea. Open-label studies confirmed the findings from the pivotal trials and demonstrated sustained therapeutic effect of ESL over time and improvement of tolerability profile in patients switching from OXC/CBZ. No unexpected safety signals emerged over >5 years of follow-up. Conclusion: Once-daily adjunctive ESL at the doses of 800 and 1,200 mg was effective to reduce the seizure frequency and was fairly well tolerated in adults with focal onset epilepsy. Starting treatment at 400 mg/day, followed by 400 mg increments every 7-14 days, could provide the optimal balance of efficacy and tolerability