347 research outputs found

    Misure curlometriche nei fondali marini

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    Nei fondali marini in cui sono presenti discontinuità nelle proprietà fisico-chimiche quali ad esempio giacimenti minerari o di combustibili naturali [1] oppure discontinuità tettoniche si possono generare correnti elettriche che si chiudono in parte attraverso l'acqua del mare elettricamente molto conduttiva e in parte nel sottosuolo marino. Inoltre sono presenti anche correnti elettriche indotte dalle variazioni del campo magnetico e correnti generate per effetto MHD dal moto dell'acqua. In generale il campo magnetico misurato al di fuori del sistema di correnti che lo generano gode di due fondamentali proprietà: è indivergente e irrotazionale [5]. All'interno delle sorgenti il rotore del campo magnetico è legato alle correnti e quindi al campo elettrico, mentre la divergenza è legata alla presenza di pozzi o sorgenti di corrente o a gradienti non lineari del campo magnetico. In questo lavoro si propone il rilevamento del campo magnetico e delle correnti nei fondali marini mediante misure dirette della divergenza e del rotore del campo magnetico locale

    IMPIEGO DELL’INTERFEROMETRIA A LARGA BANDA NELLO STUDIO DEI SEGNALI ELETTROMAGNETICI DI ORIGINE INTERNA ALLA TERRA NEL PROGETTO FIRB-ABRUZZO

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    Il terremoto di L’Aquila del 2009 ci ha resi consapevoli che occorre fare un salto qualitativo nella osservazione dei campi magnetici naturali se vogliamo estendere le nostre indagini ai fenomeni elettromagnetici che accompagnano in generale i processi geodinamici (Palangio et al., 2008). Questo terremoto è l’unico nella storia che si sia verificato praticamente sotto un osservatorio geomagnetico con 50 anni di storia. La disponibilità di un così esteso archivio dati ci consente di monitorare tutta la fase preparatoria finale del terremoto. Stando alla letteratura corrente avremmo dovuto osservare effetti cosismici molto intensi, invece i segnali osservati lambiscono appena la superficie del mare di noise in cui sono immersi (Palangio et al., 2007) soltanto in alcune bande di frequenza i segnali ipogeici emergono nettamente dal rumore di fondo (Di Lorenzo et.al., 2011). Da questa esperienza del terremoto di L’Aquila è emersa la necessità di progettare un sistema osservativo che consenta di rilevare “l’impronta” del terremoto nei segnali elettromagnetici misurati sulla superficie terrestre. Questa impronta dovrebbe fornire la prova del legame tra il fenomeno tettonico e il campo magnetico osservato. Lo studio dei segnali magnetici prima e durante la fase sismica di L’Aquila ha messo in luce alcuni aspetti interessanti che riguardano il rumore di fondo e le finestre spettrali e temporali di osservabilità degli eventuali segnali magnetici di origine interna alla terra legati al terremoto

    Protective Effects of Borago officinalis (Borago) on Cold Restraint Stress-Induced Gastric Ulcers in Rats: A Pilot Study

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    Stress is a typical body's natural defense to a generic physical or psychic change. A specific linking mechanism between ulcer onset and psycho-physical stress prolonged exposure has been reported. We decided to investigate the possible effects of Borago officinalis L. (Borago) in preventing physical (stress)-induced gastric ulcers in a rat model. Eighty male Sprague-Dawley rats were randomly divided into 16 groups, pretreated with a control solution, omeprazole (20 mg/kg), Borago methanolic extract (25, 50, 100, 250, and 500 mg/kg), Borago organic extract (50, 100, 250, and 500 mg/kg), Borago aqueous extract (5, 10, 20, 30, and 40 mg/kg), and D(-)-2-Amino-5-phosphonovaleric acid (AP5) (25 mg/kg) and kept in stressful conditions such as water immersion and restraint-induced stress ulcers. The animals were sacrificed and their stomach scored for the severity and the number of gastric ulcers. Methanolic extract (500 mg/kg) significantly reduced both ulcer parameters (***p < 0.001 and **p < 0.01, respectively). Aqueous and organic extract significantly decreased severity score at 5 and 10 mg/kg (**p < 0.01 and ***p < 0.001, respectively), and at 250 and 500 mg/kg (***p < 0.001), respectively, while gastric ulcers' resulted number significantly reduced only at 10 mg/kg (*p < 0.05) and at 500 mg/kg (**p < 0.01), respectively. On the other hand, aqueous extract significantly increased the mucosal gastric content of cAMP (*p < 0.05) and NR2A and NR2B subunits (*p < 0.05 and **p < 0.01, respectively) at 5 mg/kg. Organic extract showed also a significant cytotoxic effect at 500 and 1,000 mg/kg with a 3T3 cell viability reduction of 43.6% (**p < 0.01) and 92.1% (***p < 0.001), respectively. Borago aqueous extract at 10 mg/kg could be considered as a potential protective agent against stress-induced ulcers, and it is reasonable to possibly ascribe such protective activity to a modulation of the NR2A and NR2B subunit expression

    Corrole Polymers as a Novel Materials for Room Temperature Resistive Gas Sensors

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    Corroles, a family of contracted porphyrinoids, exhibit broad chemical interactions, undergo straightforward synthetic preparation and functionalization, and enable versatile thin film deposition. These attributes render them promising candidates for use in chemical sensors. Nevertheless, the inherently limited conductivity of corrole solid films constrains their application in mass and optical sensors. Despite this impediment, there is a great interest in matching the sensitive properties of the corrole with the features of facile miniaturization and integration into low-cost electronic circuits. This work explores the possibility of directly and simply depositing conductometric polymeric films of [5,10,15-(4-aminophenyl)corrolato] copper onto interdigitated electrodes. Remarkably, the electropolymerization protocol allows the selection of the semiconductive nature (p- or n-type) of these films, yielding two distinct sensor types: the former exhibiting high sensitivity and selectivity toward nitrogen monoxide (NO) with a slight influence of relative humidity and the other manifesting a broad spectrum of sensitivities. This breakthrough lays the foundation for developing miniaturized conductometric gas detectors, nonlinear conductometric sensing elements, and electronic nose platforms based on polycorroles

    Genetic and biochemical analyses of chromosome and plasmid gene homologues encoding ICL and ArCP domains in Vibrioanguillarum strain 775

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    Anguibactin, the siderophore produced by Vibrio anguillarum 775 is synthesized from 2,3-dihydroxybenzoic acid (DHBA), cysteine and hydroxyhistamine via a nonribosomal peptide synthetase (NRPS) mechanism. Most of the genes encoding anguibactin biosynthetic proteins are harbored by the pJM1 plasmid. In this work we report the identification of a homologue of the plasmid-encoded angB on the chromosome of strain 775. The product of both genes harbor an isochorismate lyase (ICL) domain that converts isochorismic acid to 2,3-dihydro-2,3-dihydroxybenzoic acid, one of the steps of DHBA synthesis. We show in this work that both ICL domains are functional in the production of DHBA in V. anguillarum as well as in E. coli. Substitution by alanine of the aspartic acid residue in the active site of both ICL domains completely abolishes their isochorismate lyase activity in vivo. The two proteins also carry an aryl carrier protein (ArCP) domain. In contrast with the ICL domains only the plasmid encoded ArCP can participate in anguibactin production as determined by complementation analyses and site-directed mutagenesis in the active site of the plasmid encoded protein, S248A. The site-directed mutants, D37A in the ICL domain and S248A in the ArCP domain of the plasmid encoded AngB were also tested in vitro and clearly show the importance of each residue for the domain function and that each domain operates independently.

    Laser interstitial thermal therapy (LITT) for pediatric patients affected by intracranial tumors

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    IntroductionThe surgical treatment of brain tumors has evolved over time, offering different strategies tailored to patients and their specific lesions. Among these strategies, Laser Interstitial Thermal Therapy (LITT) is one of the most recent advances in pediatric neurooncological surgery, and its results and evolution are still under assessment.MethodsWe retrospectively analyzed data from six pediatric patients with deep-seated brain tumors treated with LITT at a single center between November 2019 and June 2022. A total of four patients underwent a stereotaxic biopsy during the same operating session. The indications and preparation for LITT, technical issues, clinical and radiological follow-up, impact on quality of life, and oncological treatment are discussed.ResultsThe mean patient age eight years (ranging from 2 to 11 years). The lesion was thalamic in four patients, thalamo-peduncular in one, and occipital posterior periventricular in one. In total, two patients had been previously diagnosed with low-grade glioma (LGG). Biopsies revealed LGG in two patients, ganglioglioma grade I in one, and diffuse high-grade glioma (HGG) in one. Postoperatively, two patients presented with transient motor deficits. The mean follow-up period was 17 months (ranging from 5 to 32 months). Radiological follow-up showed a progressive reduction of the tumor in patients with LGG.ConclusionLaser interstitial thermal therapy is a promising, minimally invasive treatment for deep-seated tumors in children. The results of lesion reduction appear to be relevant in LGGs and continue over time. It can be used as an alternative treatment for tumors located at sites that are difficult to access surgically or where other standard treatment options have failed

    Inertial sensors-based assessment to detect hallmarks of chronic ankle instability during single-leg standing: Is the healthy limb “healthy”?

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    Background Chronic ankle instability can be common in sportsmen and can increase the risk of damaging the articular surfaces and result in negative consequences to joint health. Balance assessment is often used to evaluate ankle instability characteristics and guide rehabilitation protocols. This study aims to investigate balance-related parameters in people with chronic ankle instability and healthy-matched controls, using inertial sensors. Methods Ten young adults with a history of multiple ankle sprains (30 y, 25–34, 5 females) and ten matched healthy controls (30 y, 23–39, 5 females) were invited to participate in the study. Inertial sensors were placed on the head of the astragalus and on the chest to collect kinematic parameters during a 20-s single-leg stance performed on the leg with ankle instability (and corresponding for the healthy controls) and on the contralateral leg, randomly. Outcomes were calculated with MATLAB and subsequently analyzed. Findings A significant group effect was found only for the inversion angle (F1,15 = 12.514, p = 0.003, pη2 = 0.455), consisting of individuals with ankle instability being characterized by higher inversion angles (4.999 degrees, 95% CI: 1.987–8.011, p = 0.003) without significant side differences. No significant side x group effects were found for the assessed parameters. Interpretation Results from this study suggest that young adults with chronic ankle instability might be characterized by worse single-stance control in terms of inversion angle, and such worse performance could also be found in the contralateral leg. As such, inertial sensors could be used to assess kinematic parameters during balance tasks in people with chronic ankle instability

    A review of global health technology assessments of non-VKA oral anticoagulants in non-valvular atrial fibrillation.

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    Abstract Background This review assessed global health technology assessment (HTA) reports and recommendations of non-vitamin K oral anticoagulants (NOACs) in non-valvular atrial fibrillation (NVAF). Methods NHTA agency websites were searched for HTA reports evaluating NOACs versus NOACs or vitamin K antagonists. HTA methods and information on patient involvement/access were collected and empirically analyzed. Results The review identified 38 unique HTA reports published between 2012 and 2017 in 16 countries including 11 in Europe. NOACs that were cost-effective per local willingness-to-pay (WTP) thresholds were positively recommended for the treatment of NVAF. WTP thresholds ranged from €20,000 to 69,000. Apixaban was recommended in 10/12 (83%) countries, dabigatran in 9/13 (69%) countries, and rivaroxaban in 10/13 (76%) over warfarin. Edoxaban was recommended in 5/7 (71%) countries. Economic evaluations and recommendations comparing NOACs were sparse (two or three countries per NOAC) and generally favored apixaban and edoxaban, followed by dabigatran. Eleven HTA reports from four countries considered the patient voice (Canada [n = 3], Scotland [n = 3], England [n = 4], Brazil [n = 1]); however, only 2/11 (18%) developed recommendations based on this. Among the reports with a positive recommendation, 26/30 (87%) featured a decision that aligned with the approved regulatory label. Conclusions Most agencies recommended NOACs over warfarin for patients with NVAF. Few countries made statements recommending one NOAC over another. Given different WTP thresholds, a drug that is cost-effective in one market may not be in another. Therefore, the various NOAC recommendations from HTA agencies cannot be generalized across different countries

    Synthesis, biological evaluation and docking analysis of a new series of methylsulfonyl and sulfamoyl acetamides and ethyl acetates as potent COX-2 inhibitors

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    We report herein the synthesis, biological evaluation and docking analysis of a new series of methylsulfonyl, sulfamoyl acetamides and ethyl acetates that selectively inhibit cyclooxygenase-2 (COX-2) isoform. Among the newly synthesized compounds, some of them were endowed with a good activity against COX-2 and a good selectivity COX-2/COX-1 in vitro as well as a desirable analgesic activity in vivo, proving that replacement of the ester moiety with an amide group gave access to more stable derivatives, characterized by a good COX-inhibition

    A Series of COX-2 Inhibitors Endowed with NO-Releasing Properties: Synthesis, Biological Evaluation, and Docking Analysis

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    Herein we report the synthesis, biological evaluation, and docking analysis of a class of cyclooxygenase-2 (COX-2) inhibitors with nitric oxide (NO)-releasing properties. In an earlier study, a number of selective COX-2 inhibitors/NO donors were developed by conjugating a diarylpyrrole scaffold endowed with selective COX-2 inhibitory properties with various nitrooxyalkyl side chains such as esters, -amino esters, amides, -amino amides, ethers, -amino ethers, inverse esters, and amides. These candidates were found to have high invitro potencies (COX-2 inhibition at 10m: 96%), great efficacy in determining NO-vasorelaxing responses, and good antinociceptive activity in an abdominal writhing test. Among the compounds synthesized in the present work, derivative 2b [2-(2-(1-(3-fluorophenyl)-2-methyl-5-(4-sulfamoylphenyl)-1H-pyrrol-3-yl)acetamido)ethyl nitrate] showed particularly outstanding activity, with efficacy similar to that of celecoxib even at very low concentrations
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