Nonlinear optics and saturation behavior of quantum dot samples under continuous wave driving

The nonlinear optical response of self-assembled quantum dots is relevant to the application of quantum dot based devices in nonlinear optics, all-optical switching, slow light and self-organization. Theoretical investigations are based on numerical simulations of a spatially and spectrally resolved rate equation model, which takes into account the strong coupling of the quantum dots to the carrier reservoir created by the wetting layer states. The complex dielectric susceptibility of the ground state is obtained. The saturation is shown to follow a behavior in between the one for a dominantly homogeneously and inhomogeneously broadened medium. Approaches to extract the nonlinear refractive index change by fringe shifts in a cavity or self-lensing are discussed. Experimental work on saturation characteristic of InGa/GaAs quantum dots close to the telecommunication O-band (1.24-1.28 mm) and of InAlAs/GaAlAs quantum dots at 780 nm is described and the first demonstration of the cw saturation of absorption in room temperature quantum dot samples is discussed in detail

Shared Decision-Making about End-of-Life Care Scenarios Compared among Implantable Cardioverter Defibrillator Patients: A National Cohort Study

© 2019 American Heart Association, Inc. Background: Authors of expert guidelines and consensus statements recommend that decisions at the end-of-life (EOL) be discussed before and after implantation of an implantable cardioverter defibrillator (ICD) and include promotion of shared decision-making. The purpose of this study was to describe experiences, attitudes, and knowledge about the ICD at EOL in ICD recipients and to compare experiences, attitudes, and knowledge in ICD recipients with and without heart failure (HF). We further sought to determine factors associated with having discussions about EOL. Methods and Results: Using a national registry in Sweden of all ICD recipients (n=5355) in 2012, an EOL questionnaire, along with other ICD-related measures, was completed by 2403 ICD recipients. Of the participants, 1275 (n=53%) had HF. Their responses in the knowledge, experience, and attitude domains were almost identical to those without HF. Forty percent of patients with and without HF did not want to discuss their illness trajectory or deactivation of their ICD ever. In logistic regression analyses, we found that having had an ICD shock (OR, 2.05; CI, 1.64-2.56), having high levels of anxiety (OR, 1.41; CI, 1.04-1.92), and having high levels of ICD concerns (OR, 1.53; CI, 1.22-1.92) were the only significant predictors of having discussions with providers about EOL scenarios (P<0.001 for full model). Conclusions: HF was not a predictor of having an EOL conversation. Further research is needed to determine if attitudes related to not wanting to discuss EOL interfere with good quality of life and of death, or if shared decision-making should be encouraged in these individuals

Open Access

Strategies TO reduce time delays in patient

Multi-morbidity burden, psychological distress, and quality of life in implantable cardioverter defibrillator recipients: Results from a nationwide study

© 2019 Background: The prevalence of multi-morbidity in implantable cardioverter defibrillator (ICD) recipients is approximately 25%. Multi-morbidity is associated with poor health and psychological outcomes in this population and may affect ICD recipients’ quality-of-life (QOL). The purpose of this study was to determine the prevalence of psychological distress (anxiety, depressive symptoms, and Type-D personality) in ICD recipients with varying levels of comorbidities, and to examine the association between multi-morbidity burden and QOL in this population. Methods: All adults listed in the Swedish ICD and Pacemaker Registry in 2012 with an ICD implanted for at least one year were invited to participate in this study. Binary logistic regression was used to predict QOL using the EQ-5D mean index dichotomized based on median QOL scores. Multi-morbidity burden scores were based on quartile groupings. Results: A total of 2658 ICD recipients participated in the study (with a mean age of 65, 20.6% female, mean implant duration of 4.7 years, with 35.4% implanted for primary prevention of sudden cardiac arrest). Greater multi-morbidity burden, female sex, not working outside the home, history of ICD shock, negative ICD experience, higher levels of ICD-related concerns, and the presence of anxiety, depression, or Type D personality were associated with worse QOL in ICD recipients. Predictors differed by multi-morbidity burden level. Conclusions: Multi-morbidity burden and psychological distress is an essential factor related to QOL. This issue should be discussed with potential ICD recipients prior to implant. Further exploration of increased recognition and treatment of psychological distress in ICD recipients is warranted

2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy.

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