2,266 research outputs found
Satellite-Based Tele-Operation of an Underwater Vehicle-Manipulator System. Preliminary Experimental Results
Within the European project DexROV the topic of underwater intervention is addressed. In particular, a remote control room is connected through a satellite communication link to surface vessel, which is in turn connected to an UVMS (Underwater Vehicle-Manipulator System) with an umbilical cable. The operator may interact with the system using a joystick or exoskeleton. Since a direct teleoperation is not feasible, a cognitive engine is in charge of handling communication latency or interruptions caused by the satellite link, and the UVMS should have sufficient autonomy in dealing with low level constraints or secondary objectives. To this purpose, a task-priority-based inverse kinematics algorithm has been developed in order to allow the operator to control only the end effector, while the algorithm is in charge of handling both operative and joint-space constraints. This paper describes some preliminary experimental results achieved during the DexROV campaign of July 2017 in Marseilles (France), where most of the components have been successfully integrated and the inverse kinematics nicely run
Application of clinical indexes in ulcerative colitis patients in regular follow-up visit. correlation with endoscopic 'mucosal healing' and implication for management
OBJECTIVE: Ulcerative Colitis (UC) is a chronic inflammatory disease of the colon of unknown etiology. Several clinical indexes have been proposed for UC disease activity evaluation, but none have been properly validated. Moreover, the reference parameter for the scores and their prognostic value is not clear. Mucosal healing has been recently proposed as an important end-point. Aim of the present study was to evaluate the correlation of four clinical indexes with objective diagnostic tools for UC evaluation, the discriminative ability in identifying patients with endoscopic mucosal healing, and to analyze the possible prognostic indication for disease course in 1 year of follow-up. PATIENTS AND METHODS: We analyzed data of 75 patients recorded in regular follow-up visit in IBD clinic at S. Andrea Hospital, Rome, between 2007-2011. We recorded clinical data and lab tests at the time of the visit, and endoscopic/ histological repor ts performed within 1 month. Clinical indexes (Seo' activity index, Simple Clinical Colitis Activity Index, partial Mayo score and Endoscopic-Clinical Correlation Index) were calculated and correlation to endoscopic and histologic activity, and to C-reactive protein increment, was assessed by mean of Spearman's rank correlation. Discriminative ability of the indexes for patients with and without endoscopic mucosal healing was tested by calculation of area under ROC curve (AUC). Patients with low and high clinical scores were compared for number of flares and increment of therapy during 1 year of follow-up. RESULTS: Clinical indexes had a good correlation with endoscopic activity (mean r = 0.73 ± 0.06), a fair correlation with CRP-increment (mean r = 0.55 ± 0.01) and a poor one with histologic activity (mean r = 0.35 ± 0.01). The discriminatory ability of the indexes for endoscopic mucosal healing was good for all the indexes (mean AUC = 0.87 ± 0.05). Patients with high clinical score had more flares and required more frequently increase of therapy at 1 year of follow up compared with patients with low score. CONCLUSIONS: Clinical indexes have a good correlation with endoscopic activity and can discriminate patients with and without mucosal healing. Patients with low and high score have different risk of disease flare and of need to increase therapy at 1 year. Clinical indexes may represent a useful tool for disease assessment in clinical practice in UC outpatients with mildmoderate disease
Recanalization of the Native Artery in Patients with Bypass Failure
Our objective was to evaluate the possible role
of endovascular recanalization of occluded native artery
after a failed bypass graft in the case of either acute or
chronic limb-threatening ischemia otherwise leading to
amputation. In a single-center retrospective clinical analysis,
from January 2004 to March 2007 we collected 31
consecutive high-surgical-risk patients (32 limbs) with
critical limb ischemia following late ([30 days after surgery)
failure of open surgery bypass graft reconstruction.
All patients deemed unfit for surgery underwent tentative
endovascular recanalization of the native occluded arterial
tract. The mean follow-up period was 24 (range, 6–42)
months. Technical success was achieved in 30 (93.7%) of
32 limbs. The cumulative primary assisted patency calculated
by Kaplan–Meyer analysis was 92% and 88%,
respectively, at 12 and 24 months. The limb salvage rate
approached 90% at 30 months. In conclusion, our experience
shows the feasibility of occluded native artery endovascular
recanalization after a failed bypass graft, with
optimal results in terms of midterm arterial patency and
limb salvage. Our opinion is that successful recanalization
of the arterial tract previously considered unsuitable for
endovascular approach is allowed by improved competency
and experience of vascular specialists, as well as the
advances made in catheter and guidewire technology. This
group of patients would previously have been relegated to
repeat bypass grafts, with their inherently inferior patency
and recognized added technical demands. We recognize
previous surgical native artery disconnection and lack of
pedal runoff to be the main cause of technical failure.
Keywords Native artery Bypass failure
Endovascular recanalizatio
Flow resistance law in channels with fully submerged and rigid vegetation
The estimate of flow resistance in vegetated channels is a challenging topic for programming riparian vegetation management, controlling channel conveyance and flooding propensity, for designing soil bioengineering practices. In this paper, measurements collected by Gualtieri et al. (2018), in a flume where rigid cylinders were set in two arrangements (staggered, aligned) at high submergence ratios (ratio between the water depth and the vegetation height greater than 5), were used to study the effect of rigid submerged vegetation on estimating flow resistance. The theoretical flow resistance equation, obtained by integrating the power flow velocity distribution, was first summarized. Then, this flow resistance equation was calibrated and tested by measurements of Gualtieri et al. (2018). In particular, a relationship between the Γ function of the power velocity distribution, the channel slope, the flow Froude number, and the submergence ratio was established by using the available measurements carried out for the two arrangements with different stem concentrations. The calibration of this relationship was carried out by (i) distinguishing measurements corresponding to different vegetation arrangements (staggered, aligned), (ii) joining all available data, and (iii) using only a scale factor representing the effect of vegetation arrangements. For the cases (ii) and (iii), the analysis demonstrated that the theoretical flow resistance equation allows an accurate estimate of the Darcy–Weisbach friction factor, which is characterized by errors that are always less than 5% and less than or equal to 2.5% for 88% of the investigated cases
Caldera dei Campi Flegrei: potenzialitĂ di un SIT per valutazioni di pericolositĂ vulcanica
La caldera dei Campi Flegrei è un’area vulcanica attiva, attualmente in stato di quiescenza dal 1538 d.C., soggetta ad un elevato rischio vulcanico per la presenza di numerosi centri abitati e per l’immediata vicinanza alla città di Napoli. Le due maggiori eruzioni esplosive dei Campi Flegrei risalgono a circa 39 ka e 15 ka ed hanno prodotto l’Ignimbrite Campana ed il Tufo Giallo Napoletano, i depositi più noti dell’area napoletana, distribuiti su aree vastissime. Al presente, il sistema magmatico risulta essere ancora attivo, come testimoniato dall’eruzione di Monte Nuovo nel 1538, dai recenti episodi bradisismici e dall’attività fumarolica e idrotermale. Al fine di rendere disponibile alla comunità scientifica ed agli enti preposti alla gestione delle emergenze un efficace strumento tecnologico, a supporto delle valutazioni di pericolosità vulcanica, è stato implementato un sistema informativo territoriale strutturato sulla base di un database in cui sono state raccolte e organizzate tutte le informazioni vulcanologiche e territoriali sull’area. In questo lavoro, attingendo al patrimonio informativo disponibile, sono state effettuate analisi di dettaglio finalizzate alla produzione di nuovi tematismi da utilizzare per la definizione degli scenari di evento, attraverso i quali simulare le conseguenze di un evento vulcanico, di caratteristiche prefissate, che si verifichi nell’area dei Campi Flegrei
Successful Coronary Stent Retrieval From a Pedal Artery
The purpose of this article is to report complications
from a coronary drug-eluting stent lost in the
peripheral circulation. We report the case of successful
retrieval of a sirolimus coronary stent from a pedal artery in
a young patient who underwent coronary angiography for
previous anterior myocardial infarction. Recognition of
stent embolization requires adequate removal of the device
to avoid unwelcome clinical sequelae.
Keywords Coronary stent Microsnare technique
Peripheral embolization Stent retrieva
Modulations of glycerophosphorylcholine and phosphorylcholine in Friend erythroleukemia cells upon in vitro-induced erythroid differentiation: a 31P NMR study
AbstractA 31P NMR study has been carried out on Friend erythroleukemia cells (FLC) induced to undergo erythroid differentiation in vitro. Significant levels of glycerophosphorylcholine (GroPCho) and phosphorylcholine (P-Cho) were identified both in the untreated cells and in their PCA extracts. In FLC treated 4 days in vitro with either dimethylsulfoxide (DMSO) or hexamethylenebisacetamide (HMBA), the intracellular concentration of P-Cho was markedly increased, whereas that of GroPCho appeared to be significantly reduced. HMBA was more effective than DMSO in producing this effect. The concomitant modulations of GroPCho and P-Cho in differentiated FLC suggest the hypothesis that erythroid differentiation involves modifications of the regulatory mechanisms controlling biosynthesis and catabolism of phospholipids
Giuseppe Mercalli da Monza al Reale Osservatorio vesuviano: una vita tra insegnamento e ricerca. contributi presentati per l’inaugurazione dell’anno mercalliano
A cento anni dalla scomparsa di Giuseppe Mercalli, sismologo e vulcanologo, noto principalmente per
aver legato il suo nome a quello della scala per la misura dell’intensità dei terremoti, l’Istituto Nazionale di
Geofisica e Vulcanologia (INGV) ha promosso una serie di iniziative volte a rievocare la figura dell’illustre
scienziato, in un itinerario lungo un anno che ripercorre i luoghi da lui vissuti da studioso e docente,
dichiarando il duemilaquattordici “Anno Mercalliano”
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