1,138 research outputs found
Early Outcomes of Out-of-Hospital Cardiac Arrest after Early Defibrillation: a 24 Months Retrospective Analysis
Introduction: Cardiovascular disease remains the most common cause of death in the United States and most other Western nations. Among these deaths, sudden, out-of-hospital cardiac arrest claims approximately 1000 lives each day in the United States alone. Most of these cardiac arrests are due to ventricular fibrillation. Though highly reversible with the rapid application of a defibrillator, ventricular fibrillation is otherwise fatal within minutes, even when cardiopulmonary resuscitation is provided immediately. The overall survival rate in the United States is estimated to be less than 5 percent. Recent developments in automated-external-defibrillator technology have provided a means of increasing the rate of prompt defibrillation after out-of-hospital cardiac arrest. After minimal training, nonmedical personnel (e.g., flight attendants and casino workers) are also able to use defibrillators in the workplace, with lifesaving effects. Nonetheless, such programs have involved designated personnel whose job description includes assisting persons who have had sudden cardiac arrest. Data are still lacking on the success of programs in which automated external defibrillators have been installed in public places to be used by persons who have no specific training or duty to act.
Materials and Methods: All patients who had an out-of-hospital cardiac arrest between January 2003 and December 2004 and who received early defibrillation for ventricular fibrillation were included. We conducted a 24 months retrospective population-based analysis of the outcome in our population.
Results: Over a 24 month period, 446 people had nonâtraumatic cardiac arrest, and in all of them it was observed to be ventricular fibrillation. In a very few cases, the defibrillator operators were good Samaritans, acting voluntarily. Eighty-nine patients (about 19%) with ventricular fibrillation were successfully resuscitated, including eighteen who regained consciousness before hospital admission.
Conclusion: Automated external defibrillators deployed in readily accessible, well-marked areas, are really very effective in assisting patients with cardiac arrest. However, it's quite true that, in the cases of survivors, most of our users had good prior training in the use of these devices
Latino e romanzo in contatto nel XIV secolo: aspetti sintattici
Questo contributo discute alcuni aspetti dell'influenza dei modelli sintattici latini sulla lingua di tre volgarizzamenti prodotti in Toscana nella prima metà del XIV secolo: le Eroidi di Filippo Ceffi, le Metamorfosi di Arrigo Simintendi e l'Eneide di Ciampolo di Meo degli Ugurgieri. In particolare sono analizzati gli usi dei gerundi e dei participi, perché si tratta di strutture particolarmente sensibili all'influenza diretta e/o indirette dei modelli sintattici latini
La formula documentaria della defensio nelle carte notarili latine della Langobardia minor (IX secolo): uno studio linguistico
In questo lavoro sono discusse alcune questioni linguistiche legate soprattutto (ma non solo) all'analisi della sintassi della defensio, una formula molto comune nelle carte notarili della Longobardia Minore del IX secolo. La sintassi di questi testi puĂČ essere interpretata solo in un quadro di riferimento in cui le interazioni di aspetti sintattici, semantici e testuali sono considerati di importanza cruciale. In questo contributo viene anche mostrato in che modo un'analisi linguistica a grana fine delle micro-variazioni nella realizzazione linguistica della formula della defensio puĂČ apportare utili informazioni per una piĂč articolata compresione dei meccanismi sottesi al processo di scrittura delle carte notarili. In particolare, vengono formulate alcune ipotesi sulle caratteristiche dei formulari utilizzati da alcuni notai. Infine, viene proposta una discussione sul significato del predicato antestare, con alcune indicazioni relative a possibili strade da seguire per una piĂč chiara identificazione del significato di questo predicato
Sensors for Rate Responsive Pacing
Advances in pacemaker technology in the 1980s have generated a wide variety of complex multiprogrammable pacemakers and pacing modes. The aim of the present review is to address the different rate responsive pacing modalities presently available in respect to physiological situations and pathological conditions. Rate adaptive pacing has been shown to improve exercise capacity in patients with chronotropic incompetence. A number of activity and metabolic sensors have been proposed and used for rate control. However, all sensors used to optimize pacing rate metabolic demands show typical limitations. To overcome these weaknesses the use of two sensors has been proposed. Indeed an unspecific but fast reacting sensor is combined with a more specific but slower metabolic one. Clinical studies have demonstrated that this methodology is suitable to reproduce normal sinus behavior during different types and loads of exercise. Sensor combinations require adequate sensor blending and cross checking possibly controlled by automatic algorithms for sensors optimization and simplicity of programming. Assessment and possibly deactivation of some automatic functions should be also possible to maximize benefits from the dual sensor system in particular conditions. This is of special relevance in patient whose myocardial contractility is limited such as in subjects with implantable defibrillators and biventricular pacemakers. The concept of closed loop pacing, implementing a negative feedback relating pacing rate and the control signal, will provide new opportunities to optimize dual-sensors system and deserves further investigation. The integration of rate adaptive pacing into defibrillators is the natural consequence of technical evolution
Pacemaker Prevention Therapy in Drugârefractory Paroxysmal Atrial Fibrillation: Reliability of Diagnostics and Effectiveness of Prevention Pacing Therapy in Vitatronâą SelectionÂź device
Introduction. Atrial fibrillation (AF), the most common and rising disorder of cardiac rhythm, is quite difficult to control and/or to treat. Non pharmacological therapies for AF may involve the use of dedicated pacing algorithms to detect and prevent atrial arrhythmia that could be a trigger for AF onset. Selection 900E/AF2.0 Vitatron DDDRP pacemaker (1) keeps an atrial arrhythmia diary thus providing detailed onset reports of arrhythmias of interest, (2) provides us data about the number of premature atrial contractions (PACs) and (3) plots heart rate in the 5 minutes preceding the detection of an atrial arrhythmia. Moreover, this device applies four dedicated pacing therapies to reduce the incidence of atrial arrhythmia and AF events.
Aim of the Study. To analyze the reliability to record atrial arrhythmias and evaluate effectiveness of its AF preventive pacing therapies.
Material and Methods. We enrolled 15 patients (9 males and 6 females, mean age of 71±5 years, NYHA class IâII), with a DDDRP pacemaker implanted for a âbradycardiaâtachycardiaâ syndrome, with advanced atrioventricular conduction disturbances. We compared the number and duration of AF episodesâ stored in the device with a contemporaneous 24h Holter monitoring. After that, we switched on the atrial arrhythmias detecting algorithms, starting from an atrial rate over 180 beats per minute for at least 6 ventricular cycles, and ending with at least 10 ventricular cycles in sinus rhythm. Thereafter, in order to evaluate the possible reduction in PACs number and in number and duration of AF episodes, we tailored all the four pacing preventive algorithms. Patients were followed for 24±8 months (from 20 to 32 months).
Results. All 59 atrial arrhythmia episodes occurred in the first part of this trial, were correctly recorded by both systems, with a correlation coefficient (r) of 0.96. During the followâup, we observed a significant reduction not only in PACs number (from 83±12/day to 2.3±0.8/day) but also in AF episodes (from 46±7/day to 0.12±0.03/day) and AF burden (from 93%±6% to 0.3%±0.06%). An increase in atrial pacing percentages (from 3%±0.5% to 97%±3%) was also contemporaneously observed.
Conclusion. In this pacemaker, detection of atrial arrhythmia episodes is highly reliable, thus making available an appropriate monitoring of heart rhythm, mainly suitable in AF asymptomatic patients. Moreover, the significant reduction of atrial arrhythmia episodes indicates that this might represent a suitable therapeutic option for an effective preventive therapy of AF in paced bradyâtachy patients
On the Political Use of the Reportative Conditional in Italian Newspapers
The labels condizionale riportivo (reportative conditional) or condizionale citativo (quotative conditional) are employed to describe certain uses of the conditional mood in Italian, particularly when the conditional marks the non-firsthand nature of a given piece of information. This use of the conditional is particularly frequent in the language of newspapers. However, reportative conditionals may also carry epistemic overtones, and they are used by speakers when they want to stress that they are not committed to the truthfulness of the information reported. Depending on the context, a reportative conditional can be either a purely evidential marker, or an evidential marker with epistemic overtones. Some Italian (trained) speakers exploit this ambiguity as a strategy to play on the two possible interpretations. This strategy is particularly significant in contexts in which the speaker is supposed to be neutral and, as such, must refrain from expressing her/his epistemic stance when recounting events. In this paper, after an analysis of the different sections of newspapers in which reportative conditionals occur, I will discuss one particular use of reportative conditionals in Italian newspapers, i.e. the âpoliticalâ use of conditionals. To this end, I will carry out a qualitative analysis of some excerpts from newspapers published between the second half of the 19th century and today. In particular, it will be shown that journalists often take advantage of the ambiguities underlying reportative conditionals in Italian, in order to discredit the political position of a person (or group) without overtly questioning it
On the Political Use of the Reportative Conditional in Italian Newspapers
The labels condizionale riportivo (reportative conditional) or condizionale citativo (quotative conditional) are employed to describe certain uses of the conditional mood in Italian, particularly when the conditional marks the non-firsthand nature of a given piece of information. This use of the conditional is particularly frequent in the language of newspapers. However, reportative conditionals may also carry epistemic overtones, and they are used by speakers when they want to stress that they are not committed to the truthfulness of the information reported. Depending on the context, a reportative conditional can be either a purely evidential marker, or an evidential marker with epistemic overtones. Some Italian (trained) speakers exploit this ambiguity as a strategy to play on the two possible interpretations. This strategy is particularly significant in contexts in which the speaker is supposed to be neutral and, as such, must refrain from expressing her/his epistemic stance when recounting events. In this paper, after an analysis of the different sections of newspapers in which reportative conditionals occur, I will discuss one particular use of reportative conditionals in Italian newspapers, i.e. the âpoliticalâ use of conditionals. To this end, I will carry out a qualitative analysis of some excerpts from newspapers published between the second half of the 19th century and today. In particular, it will be shown that journalists often take advantage of the ambiguities underlying reportative conditionals in Italian, in order to discredit the political position of a person (or group) without overtly questioning it. The labels condizionale riportivo (reportative conditional) or condizionale citativo (quotative conditional) are employed to describe certain uses of the conditional mood in Italian, particularly when the conditional marks the non-firsthand nature of a given piece of information. This use of the conditional is particularly frequent in the language of newspapers. However, reportative conditionals may also carry epistemic overtones, and they are used by speakers when they want to stress that they are not committed to the truthfulness of the information reported. Depending on the context, a reportative conditional can be either a purely evidential marker, or an evidential marker with epistemic overtones. Some Italian (trained) speakers exploit this ambiguity as a strategy to play on the two possible interpretations. This strategy is particularly significant in contexts in which the speaker is supposed to be neutral and, as such, must refrain from expressing her/his epistemic stance when recounting events. In this paper, after an analysis of the different sections of newspapers in which reportative conditionals occur, I will discuss one particular use of reportative conditionals in Italian newspapers, i.e. the âpoliticalâ use of conditionals. To this end, I will carry out a qualitative analysis of some excerpts from newspapers published between the second half of the 19th century and today. In particular, it will be shown that journalists often take advantage of the ambiguities underlying reportative conditionals in Italian, in order to discredit the political position of a person (or group) without overtly questioning it
Development of novel polymeric and composite nano-structured micro-porous materials for impact resistance applications
PhD ThesisImpact resistant materials (IRMs) are widely used in the automotive and packaging
industry. Their main purpose is the protection of the transported occupants or
goods. Cellular materials as well as structures combine lightness with large
deformation under load. The energy absorption mechanism is provided by limiting
the peak load and ensuring the elastic deformation of the IRMs. Polymeric foams
are largely used as IRMs due to their cellular structure. Prediction of the foam
properties in terms of Youngâs Modulus (Elastic Modulus) and the onset of Plateau
Region can be related to the foam density and the mechanical properties of the bulk
material (Gibson and Ashby model). The structure of the foam is only partly
accounted for in the Gibson and Ashby model in terms of material density.
However, it is possible to produce cellular materials with the same density but very
different internal architectures. This cannot easily be exploited in conventional
polymer foams but the processing of High Internal Phase Emulsion (PolyHIPE) and
its polymerisation route to produce PolyHIPE Polymers (PHPs) can produce
materials with very different structures. Experiments have revealed that the PHPs
properties are dictated by their detailed structure. Elastic PHPs with: 1) varying
ratio of polymerizable oil phase with respect to aqueous phase and 2) varying
mixing time/energy input were produced and tested by mechanical compression at
different temperatures and strain rates. The elastic modulus increases with a
quadratic law as a function of the polymerizable oil phase content of the HIPE when
the mixing time is the same, as predicted by the model. The Specific Absorption
Energy (SAE), represented by the area under the stress-strain curve, increases in a
similar way.
Increasing mixing time on HIPE has the effect of modifying the cellular structure.
Smaller pores and narrower distribution of pores are observed. Such features are
consistent for any set of PHPs densities and represent a design tool when some
specific mechanical characteristics are prescribed.
The assessment of process-structure-properties relationships was performed by
combining the mechanical response of the various PHPs with the imaging of their
structure by Scanning Electron Microscopy. The properties of PHPs were
benchmarked with reference to two commercially available products. One material
is characterised by a porous structure with a relatively high Youngâs Modulus while
the other by a non-porous and composite-like solid structure with lower elastic
modulus. The properties of the PHPs can be engineered to shift from a foam-like
material to a composite-like through the processing parameters which in turn
modify the material porous structure. The temperature has very limited effect on
the PHPs material unlike for the reference commercial materials.
The enhancement of properties (increasing Elastic Modulus and SAE) induced by
changing the processing route are remarkable for such a class of porous materials.
When plotted on a Modulus-Density chart, the PHPs fill an existing material-chart
gap, representing a new class of materials and opening new possibilities as IRMs.Try & Lilly Lt
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