1,721,330 research outputs found
Il teatro inciso di Edward Gordon Craig
No full textIl saggio approfondisce l'inclinazione grafica del celebre scenografo e teorico del teatro anglosassone di inizi Novecento. La vocazione al disegno è nel caso di Craig totalmente sinergica al suo pensiero sul teatro, ed infatti è stata quasi sempre presa in esame dal punto di vista drammaturgico. Il taglio storico-artistico del saggio permette di riflettere ed osservare le qualità innovative della raffigurazione grafica, la sua contestualizzazione e peculiarità nel panorama artistico del suo tempo, fino agli esiti più avanzati, quelli dell'"Hamlet"
Carlo Ludovico Ragghianti ed Enrico Crispolti fra similitudini e antinomie. Alle origini di un rapporto e attorno ad Arte moderna in Italia 1915-1935
No full textIl saggio indaga alcuni aspetti della giovanile attività critica e libellistica di Enrico Crispolti nelle sue relazioni con Carlo Ludovico Ragghianti. Partendo dal coinvolgimento di Crispolti trentenne nell'organizzazione e negli studi preliminari alla esposizione "Arte moderna in Italia 1915-1935" curata da Ragghianti a Firenze in Palazzo Strozzi all'indomani dell'alluvione, approfondimento a cui in buona parte si dedica il testo attraverso il vaglio di documenti inediti nei fonti d'archivio dei due studiosi, si è risaliti agli anni ancora precedenti, epoca dei primi rapporti Crispolti-Ragghianti, momenti della formazione critica e dell'energico posizionamento del giovanissimo Crispolti, allievo di Lionello Venturi, nel vivace panorama critico e artistico degli anni Cinquanta
Analysis of CMRR in Doubly-Tuned Transformer Baluns
No full textThis work rigorously investigates circuit techniques that aim at increasing the common-mode rejection ratio (CMRR) in a transformer-based doubly-tuned balun network. The presented analytical results are able to predict and quantify the CMRR for various circuit solutions employed in the literature. Moreover, they are able to predict the conditions under which such solutions are not effective. Simulations performed on use cases of practical interest validate the developed theory
Brugada Syndrome: The Endless Conundrum
No full textOverall, we feel that the evidence that we provided in 2002 and confirmed with the PRELUDE study—that a spontaneous type 1 pattern and a history of syncopal episodes (excluding syncopal episodes that are likely to be neurally mediated) is the strongest predictor of arrhythmic risk in Brugada syndrome and that the absence of a spontaneous type 1 pattern is the strongest predictor of favorable outcome at follow-up—is now further strengthened by these new data from Casado-Arroyo et al. that question the role of PES. In this respect, in light of the confirmed less malignant outcome of patients with Brugada syndrome, we believe PES inducibility may have an additional predictive value in addition to spontaneous type 1 pattern and syncope that may be highlighted only in a very large cohort that is able to demonstrate its effect. However, the lack of negative predictive value remains the major limitation in the clinical use of PES
Benefit of Implantable Cardioverter-Defibrillators in Patients with Catecholaminergic Polymorphic Ventricular Tachycardia - Reply
No full textIn Reply: We thank Maass and Cox for their comment on our work,1 and for stimulating the discussion on the role of implantable cardioverter-defibrillators (ICDs) in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT).
In our cohort, we did not observe an excess of crude mortality rates in ICD carriers (0.15 per 100 person-years) compared with noncarriers (0.56 per 100 person-years; P = .38). Considering that in this relatively young population, the dominant contributor to mortality is sudden cardiac death, we assessed the likelihood of survival at the occurrence of the first life-threatening arrhythmic event (LTAE; composite of sudden cardiac death, aborted cardiac arrest, or hemodynamically nontolerated sustained ventricular tachycardia), a previously validated hard end point.2,3 Our data show that patients without an ICD were 25-fold more likely to die at the occurrence of the first LTAE compared with ICD carriers, supporting the conclusion that ICD confers a survival benefit in high-risk patients with CPVT.1 However, when discussing the benefits and drawbacks of ICD, mortality should not be the only factor considered, since patients without an ICD may survive an out-of-hospital cardiac arrest with neurological disability secondary to anoxic brain injury, as in the case of 2 of 6 patients without an ICD who survived a cardiac arrest in our cohort.
We agree with the authors that appropriate ICD shocks are not always necessary, especially on self-terminating arrhythmias. We acknowledge that a typographic mistake occurred during the editing of the article, and the sentence cited by the authors regarding the episodes terminated by the ICD should read, “Overall, all 15 episodes of VF [ventricular fibrillation] were successfully interrupted, while only 3 of 6 episodes (50%) of hemodynamically unstable, polymorphic fast VT [ventricular tachycardia] were terminated (P < .001).”4 We thank the authors for giving us the opportunity to clarify that the majority of ICD shocks on LTAE occurred on ventricular fibrillation, which are known to not cease spontaneously. This is also explained by our long-standing collaboration with Maurizio Gasparini, MD, which led to us to adopt into our clinical practice ICD programming with a long detection to deliver a shock only on ventricular fibrillation, a strategy demonstrated to reduce the rate of both appropriate and inappropriate shocks without differences in mortality.5 Regarding the 3 of 6 shocks (50%) on polymorphic VT that failed to terminate the arrhythmia, this is not surprising, since it is known that substrate (and arrhythmia mechanism) is a potent predictor of shock efficacy.6
Lastly, neither flecainide nor verapamil nor left cardiac sympathetic denervation have been demonstrated to reduce mortality in patients with CPVT at the time of the publication of this work. Considering that the practice of modern medicine should be based on the best evidence available, at the present time, these therapies cannot represent an alternative for ICD
E-Band Frequency Sextupler With >35 dB Harmonics Rejection Over 20 GHz Bandwidth in 55 nm BiCMOS
Full text linkA frequency multiplier by six (sextupler) for local oscillation (LO) generation in E-band is presented. It comprises a tripler, a doubler, and an output buffer. A detailed analysis is proposed to discuss the optimal order of the multiplication stages to minimize the unwanted harmonics of the input. Moreover, novel circuit topologies for the tripler and doubler are introduced. The tripler core is devised to reproduce the transcharacteristic of a third-order polynomial that ideally generates only the third harmonic of a sinusoidal input signal. By leveraging an envelope detector for adaptive biasing, the circuit maintains excellent suppression of the driving signal and unwanted harmonics over wide variations of the input power. The proposed topology improves output signal purity and current conversion efficiency against classical triplers based on the transistors biased in class C. The cascaded frequency doubler is based on a novel push-push configuration that provides a differential output and excellent odd-order harmonic rejection due to an enhanced robustness to amplitude and phase unbalances of the driving signal. The sextupler is fabricated in a 55-nm SiGe-BiCMOS technology. Driven with a 0-dBm input signal and consuming 63.1 mW of dc power, it delivers up to 5.6 dBm at 72 GHz. is above 0 dBm over 20-GHz bandwidth (BW), while undesired harmonics of the input are suppressed by more than 35 dB. Compared to previously reported millimeter-wave frequency multipliers, the sextupler demonstrates improved harmonic rejection, conversion gain, and efficiency, without compromising the operation BW and output power
High Gain 130GHz Frequency Doubler with Colpitts Output Buffer Delivering Pout up to 8dBm with 6% PAE in 55nm SiGe BiCMOS
No full textA mmWave frequency doubler in a SiGe BiCMOS technology is presented. The core of the circuit comprises a push-push pair, for second-harmonic generation, and a stacked common-collector Colpitts oscillator which works as a common-base injection-locked amplifier to boost the conversion gain and output power. The class-C operation of the transistor in the Colpitts buffer leads to a pulsed current shape with enhanced second-harmonic content. As a result, the power conversion gain of the frequency doubler is increased by up to 10dB, compared to the push-push pair alone. Moreover, the common-collector configuration keeps separate the oscillator tank from the load, allowing independent optimization of the harmonic conversion efficiency and the load impedance for maximum power delivery. Realized in a SiGe BiCMOS technology with 330GHz fmax, the proposed frequency doubler delivers Pout up to 8dBm at 130GHz with 13dB conversion gain and 6.3% Power Added Efficiency. A Figure of Merit is proposed to benchmark frequency doublers and the presented chip shows up to 3 times improvement compared to previously reported designs in the same frequency range
Conduction disorder and primary cardiac tumor: a fatal case of multiple lipomas of the right atrium
Full text linkN/
- …
