Deep strong coupling regime of the Jaynes-Cummings model

We study the quantum dynamics of a two-level system interacting with a quantized harmonic oscillator in the deep strong coupling regime (DSC) of the Jaynes-Cummings model, that is, when the coupling strength g is comparable or larger than the oscillator frequency ω (g/ω≳1). In this case, the rotating-wave approximation cannot be applied or treated perturbatively in general. We propose an intuitive and predictive physical frame to describe the DSC regime where photon number wave packets bounce back and forth along parity chains of the Hilbert space, while producing collapse and revivals of the initial population. We exemplify our physical frame with numerical and analytical considerations in the qubit population, photon statistics, and Wigner phase space.

Pilot study: Gelafundin (polygeline) 4% plus antibiotics in the treatment of high-risk cirrhotic patients with spontaneous bacterial peritonitis

BACKGROUND

Cirrhotic patients with spontaneous bacterial peritonitis (SBP) have elevated rates of renal impairment and mortality. It has been shown that cefotaxime plus albumin infusion decrease renal impairment compared with antibiotic treatment alone, in patients with serum bilirubin >4 mg/dL or creatinine >1 mg/dL.

AIM

To assess clinical outcomes of high-risk cirrhotic patients with SBP who were treated with antibiotics associated with Gelafundin (polygeline) 4%.

METHODS

Twenty nine cirrhotic patients with SBP and serum bilirubin >4 mg/dL or creatinine >1 mg/dL were enrolled. Ceftriaxone was administered in doses of 2 g/day and Gelafundin 4% was given intravenously at 1.5 g/kg of body weight at the time of the diagnosis, followed by 1 g/kg on day 3. Renal impairment was defined as nonreversible deterioration of renal function during hospitalization.

RESULTS

Eight patients (27.5%) had basal renal failure. Infection resolved in 28 (96.6%) patients. Renal impairment occurred in four patients (13.8%), and three patients (10.4%) died during hospitalization. Mortality within 90 days after discharge was 34.5% (10 patients).

CONCLUSION

The rates of renal impairment and mortality in high-risk patients with SBP suggest that Gelafundin 4% administration given with ceftriaxone may be a less expensive therapeutic alternative to albumin.

Microwave photon detector in circuit QED

In this Letter we design a metamaterial composed of discrete superconducting elements that implements a high-efficiency microwave photon detector. Our design consists of a microwave guide coupled to an array of metastable quantum circuits, whose internal states are irreversibly changed due to the absorption of photons. This proposal can be widely applied to different physical systems and can be generalized to implement a microwave photon counter.

[Telemedicine and teledermatology (II): current state of research on dermatology teleconsultations]

The rapid increase in the use of telemedicine makes a critical appraisal of these services essential. This article reviews the current evidence from studies of teledermatology with sufficiently rigorous methodology to allow reasonable conclusions to be drawn. The review is organized according to areas of research in teledermatology: reliability of diagnosis and management, accuracy, outcomes, costs, and satisfaction. The conclusion of this review is that teledermatology has been shown to be feasible and reliable but that it has a long way to go before maturing as a medical technology in daily practice. The largest body of evidence relates to the reliability of diagnosis and management, but although numerous studies have been performed, many have marked methodological shortcomings. Accuracy studies have been conducted in skin oncology with appropriate methodology that show an accuracy comparable to that of face-to-face consultations. Studies of health outcomes should be designed such that a faithful assessment of the final outcomes, costs, and satisfaction with teledermatology systems can be carried out.

[Telemedicine and teledermatology (I): concepts and applications]

Telemedicine refers to the use of telecommunications technology to provide health care and medical information. The practice of medicine--and dermatology in particular--is undergoing a great upheaval due to advances in information technology. This article briefly reviews the origin, development, applications, benefits, methodology, and components of telemedicine. Specifically, we will analyze the types and applications of teledermatology, paying particular attention to technical, organizational, and legal aspects.

Sudden birth versus sudden death of entanglement in multipartite systems

We study the entanglement dynamics of two cavities interacting with independent reservoirs. Expectedly, as the cavity entanglement is depleted, it is transferred to the reservoir degrees of freedom. We find also that when the cavity entanglement suddenly disappears, the reservoir entanglement suddenly and necessarily appears. Surprisingly, we show that this entanglement sudden birth can manifest before, simultaneously, or even after entanglement sudden death. Finally, we present an explanatory study of other entanglement partitions and of higher dimensional systems.

[Preliminary results of DERMATEL: prospective randomized study comparing synchronous and asynchronous modalities of teledermatology]

INTRODUCTION

There is considerable variability in the results of studies that evaluate diagnostic reliability in teledermatology. There are only two studies that compare the synchronous and asynchronous modalities of teleconsult in the same sample. We present the results of the pilot project DERMATEL, a study of diagnostic concordance that aims to increase the evidence of these aspects.

MATERIAL AND METHODS

One-hundred-fifty.nine patients referred by the general practitioner in the first consult were randomized (algorithm 3:2:1) in three arms: asyncronous teledermatology (store-and-forward or SAF), synchronous teldermatology (real-time or VTC), and conventional consult (CC). We used high-quality, fixed digital images in all cases. The patients on the VTC teledermatology arm were also evaluated by videoconference. Finally all patients attended a face-to-face consult, considered the gold standard of patient care. A second dermatologist evaluated the diagnostic and management concordance between the teleconsults and the face-to-face consults.

RESULTS

One-hundred.forty-seven patients completed the study as follows: 74 in the SAF teledermatology arm, 47 in the VTC teledermatology arm and 26 in the conventional consult (control group). The teledermatological (SAF and VTC) and face-to-face evaluations were identical in 100 of 121 patients (82.6%). The errors were mild in 14 cases (11.6%) and severe in 7 (5.8%). The diagnostic concordance was very high (kappa=0,813). The errors grouped by diseases were as follows: 6/54 (11%) for tumors, 10/30 (33.3%) for inflammatory conditions, 1/20 (5%) for infectious diseases, 3/12 (25%) for alopecia/acne and 1/5 (20%) for others. There were 15 errors in the SAF teledermatology arm (20.3%) and 6 in the VTC teledermatology arm (12.8%); these differences were not statistically significant (chi2 1.12; p=0.288).

CONCLUSION

The reliability of dermatological teleconsult is very high, especially for tumoral or infectious diseases. The synchronous interaction with audio requires more resources, is difficult to coordinate and its diagnostic efficacy is not superior to SAF teledermatology.

Comparative study between nadolol and 5-isosorbide mononitrate vs. endoscopic band ligation plus sclerotherapy in the prevention of variceal rebleeding in cirrhotic patients: a randomized controlled trial

BACKGROUND

After variceal bleeding, cirrhotic patients should receive secondary prophylaxis.

AIM

To compare nadolol plus 5-isosorbide mononitrate (5-ISMN) with endoscopic band ligation. The end points were rebleeding, treatment failure and death.

METHODS

One hundred and nine cirrhotic patients with a recent variceal bleeding were randomized: nadolol plus 5-ISMN in 57 patients and endoscopic band ligation in 52 patients.

RESULTS

The mean follow-up was 17 and 19 months in nadolol plus 5-ISMN and endoscopic band ligation groups, respectively. No differences were observed between groups in upper rebleeding (47% vs. 46%), variceal rebleeding (40% vs. 36%), failure (32% vs. 22%), major complications (7% vs. 13.5%) and death (19% vs. 20%), respectively. The actuarial probability of remaining free of rebleeding, failure and deaths were similar in both groups. Time to rebleeding shows that endoscopic band ligation patients had an early rebleed, with a median of 0.5 month (95% CI: 0.0-4.2) compared with patients from nadolol plus 5-ISMN, 7.6 months (95% CI: 2.9-12.3, P < 0.013). Multivariate analysis indicated that outcome-specific predictive factor(s) for rebleeding was Child A vs. B + C (P < 0.01); for failure was Child A vs. B + C (P < 0.02); and for death ascites (P < 0.01) and rebleeding (P < 0.02).

CONCLUSION

This trial suggests no superiority of endoscopic band ligation over nadolol plus 5-ISMN mononitrate for the prevention of rebleeding in cirrhotic patients.