Quantum anomalies and linear response theory

The analysis of diffusive energy spreading in quantized chaotic driven systems, leads to a universal paradigm for the emergence of a quantum anomaly. In the classical approximation a driven chaotic system exhibits stochastic-like diffusion in energy space with a coefficient $D$ that is proportional to the intensity $\epsilon^2$ of the driving. In the corresponding quantized problem the coherent transitions are characterized by a generalized Wigner time $t_{\epsilon}$, and a self-generated (intrinsic) dephasing process leads to non-linear dependence of $D$ on $\epsilon^2$.Comment: 8 pages, 2 figures, textual improvements (as in published version

Anomalous decay of a prepared state due to non-Ohmic coupling to the continuum

We study the decay of a prepared state $E_0$ into a continuum {E_k} in the case of non-Ohmic models. This means that the coupling is $|V_{k,0}| \propto |E_k-E_0|^{s-1}$ with $s \ne 1$. We find that irrespective of model details there is a universal generalized Wigner time $t_0$ that characterizes the evolution of the survival probability $P_0(t)$. The generic decay behavior which is implied by rate equation phenomenology is a slowing down stretched exponential, reflecting the gradual resolution of the bandprofile. But depending on non-universal features of the model a power-law decay might take over: it is only for an Ohmic coupling to the continuum that we get a robust exponential decay that is insensitive to the nature of the intra-continuum couplings. The analysis highlights the co-existence of perturbative and non-perturbative features in the dynamics. It turns out that there are special circumstances in which $t_0$ is reflected in the spreading process and not only in the survival probability, contrary to the naive linear response theory expectation.Comment: 13 pages, 11 figure

Clinical Outcome of Breast Cancer Occurring after Treatment for Hodgkin's Lymphoma: Case-Control Analysis

Background: To evaluate diagnosis, management and outcome of breast cancer (BC) occurring after irradiation for Hodgkin's lymphoma (HL). Methods: 39 cases of BC in 28 HL survivors were retrospectively reviewed. 21 patients were included in a case-control analysis. Results: The median age at diagnosis of HL and BC was 25.3 and 45.3 years, respectively. The median interval to develop BC was 16.1 years. Eleven women (39.2%) had bilateral disease. Mode of detection of the index breast cancers was by mammographic screening in 17 patients (60.7%), palpable lump in 8 patients (28.6%), clinical examination in two patients (7.1%), and unknown in one patient (3.6%). Case-control analysis showed that histological features and prognosis of BC after HL were similar to those of primary BC, however, for BC after HL, mastectomy was the predominant surgery (P = .001) and adjuvant radiotherapy and anthracycline-based chemotherapy were less frequently used as compared to primary BC (P < .001 and .003, respectively). Conclusion: The previous history of HL does not appear to be a poor prognostic factor for BC occurring thereafter

Clinical outcome of breast cancer occurring after treatment for Hodgkin's lymphoma: case-control analysis

<p>Abstract</p> <p>Background</p> <p>To evaluate diagnosis, management and outcome of breast cancer (BC) occurring after irradiation for Hodgkin's lymphoma (HL).</p> <p>Methods</p> <p>39 cases of BC in 28 HL survivors were retrospectively reviewed. 21 patients were included in a case-control analysis.</p> <p>Results</p> <p>The median age at diagnosis of HL and BC was 25.3 and 45.3 years, respectively. The median interval to develop BC was 16.1 years. Eleven women (39.2%) had bilateral disease. Mode of detection of the index breast cancers was by mammographic screening in 17 patients (60.7%), palpable lump in 8 patients (28.6%), clinical examination in two patients (7.1%), and unknown in one patient (3.6%). Case-control analysis showed that histological features and prognosis of BC after HL were similar to those of primary BC, however, for BC after HL, mastectomy was the predominant surgery (<it>P </it>= .001) and adjuvant radiotherapy and anthracycline-based chemotherapy were less frequently used as compared to primary BC (<it>P </it>< .001 and .003, respectively).</p> <p>Conclusion</p> <p>The previous history of HL does not appear to be a poor prognostic factor for BC occurring thereafter.</p

Physical Electronics

Contains research objectives and reports on two research projects

Physical Electronics

Contains research objectives and reports on four research projects

Quantum decay into a non-flat continuum

We study the decay of a prepared state into non-flat continuum. We find that the survival probability $P(t)$ might exhibit either stretched-exponential or power-law decay, depending on non-universal features of the model. Still there is a universal characteristic time $t_0$ that does not depend on the functional form. It is only for a flat continuum that we get a robust exponential decay that is insensitive to the nature of the intra-continuum couplings. The analysis highlights the co-existence of perturbative and non-perturbative features in the local density of states, and the non-linear dependence of $1/t_0$ on the strength of the coupling.Comment: 10 pages, 4 figure

Predictive factors for success of awake proning in hypoxemic respiratory failure secondary to COVID-19: A retrospective cohort study

BACKGROUND: Awake prone positioning has been recommended as an adjunctive measure in spontaneously breathing patients with hypoxemic respiratory failure during the COVID-19 pandemic. It remains uncertain as to how long this should be implemented, what variables to follow and who would be the ideal candidates for this adjunctive therapy. METHODS: A retrospective chart review of patients admitted from April to August 2020 within our institution with multifocal pneumonia and hypoxemic respiratory failure secondary to COVID-19 who underwent awake-proning for at least 3 hours was conducted. RESULTS: Improvement in respiratory parameters including ROX (SpO2/Fio2/ Respiratory Rate) indices and inflammatory markers within 4 days of institution of awake proning predicted a higher chance for success of this strategy in preventing need for mechanical ventilation. Moreover, benefits of awake proning were limited to patients with mild to moderate ARDS. CONCLUSIONS: Awake prone positioning can be safely performed with improvement in oxygenation. However, its institution may be beneficial only in patients with mild to moderate ARDS and requires careful evaluation of respiratory parameters and serum inflammatory markers to avoid a delay in endotracheal intubation and consequent increase in mortality rates