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We investigate the use of Quantum Neural Networks for discovering and implementing quantum error-correcting codes. Our research showcases the efficacy of Quantum Neural Networks through the successful implementation of the Bit-Flip quantum error-correcting code using a Quantum Autoencoder, effectively correcting bit-flip errors in arbitrary logical qubit states. Additionally, we employ Quantum Neural Networks to restore states impacted by Amplitude Damping by utilizing an approximative 4-qubit error-correcting codeword. Our models required modification to the initially proposed Quantum Neural Network structure to avoid barren plateaus of the cost function and improve training time. Moreover, we propose a strategy that leverages Quantum Neural Networks to discover new encryption protocols tailored for specific quantum channels. This is exemplified by learning to generate logical qubits explicitly for the bit-flip channel. Our modified Quantum Neural Networks consistently outperformed the standard implementations across all tasks.

Artificial intelligence in the form of deep learning is now very popular and directly implemented in many areas of science and technology. In the present work we study time evolution of Discrete Breathers in one-dimensional nonlinear chains using the framework of Convolutional Neural Networks. We focus on differentiating discrete breathers which are localized nonlinear modes from linearized phonon modes. The breathers are localized in space and time-periodic solutions of non-linear discrete lattices while phonons are the linear collective oscillations of interacting atoms and molecules. We show that deep learning neural networks are indeed able not only to distinguish breather from phonon modes but also determine with high accuracy the underlying nonlinear on-site potentials that generate breathers. This work can have extensions to more complex natural systems.

We focus on chaotic dynamical systems and analyze their time series with the use of autoencoders, i.e., configurations of neural networks that map identical output to input. This analysis results in the determination of the latent space dimension of each system and thus determines the minimal number of nodes necessary to capture the essential information contained in the chaotic time series. The constructed chaotic autoencoders generate similar maximal Lyapunov exponents as the original chaotic systems and thus encompass their essential dynamical information.

We identified the incidence and risk factors of venous thromboembolism in 335 chemotherapy-treated patients with urothelial cancer. The Khorana risk score did not accurately predict risk for thromboembolic events; on the contrary, history of vascular events was associated with a 3-fold increase of this risk. The role of prophylaxis in this group should be further studied. © 2020 Elsevier Inc. Background: Venous thromboembolic events (VTEs) frequently occur in cancer patients. Risk assessment models (RAMs) for cancer-associated thrombosis have been proposed. However, advanced urinary tract cancer (aUTC) was not adequately represented in these models. We studied the incidence of VTEs, the risk factors, and the applicability of recently described RAMs. Patients and Methods: Data from 335 patients with aUTC treated with chemotherapy between April 1995 and September 2015 in a single institution were analyzed. Results: A total of 95.2% received platinum-based first-line chemotherapy. Twenty-nine patients (8.7%) experienced VTEs. The 6-, 12-, and 24-month VTE incidence was 7.4% (95% confidence interval [CI], 4.8-10.6), 8.1% (95% CI, 5.4-11.5) and 9.4% (95% CI, 6.4-13.1), respectively. No significant association of VTE incidence with the Khorana risk score was observed. History of vascular event (VTE and/or arterial thromboembolic event) was significantly associated with the development of VTE. Patients with such history had a 6-, 12-, and 24-month VTE incidence of 16.2% (95% CI, 6.6-29.7), 19.2% (95% CI, 8.4-33.3), and 25.2% (95% CI, 12.5-40.1) compared to 6.2% (95% CI, 3.7-9.4), 6.6% (95% CI, 4.1-10), and 7.1% (95% CI, 4.4-10.6) of those who did not. The discriminatory ability of this factor adjusted for leucocyte count, sex, Eastern Cooperative Oncology Group performance status, and type of chemotherapy reached 0.79 (95% CI, 0.71-0.87) compared to the 0.58 (95% CI, 0.49-0.66) for the Khorana risk score. Conclusion: Development of tumor-specific algorithms for the risk of VTEs is advisable. Patients with aUTC and a history of vascular events are at high risk for VTE development, and prophylaxis should be prospectively studied in this group. © 2020 Elsevier Inc.

Neoadjuvant Chemotherapy (NACT) followed by Interval Debulking Surgery (IDS) is an accepted frontline treatment in patients with advanced Epithelial Ovarian Cancer (EOC). Histopathologic assessment of tumor post NACT may provide a surrogate for response to treatment. The present study aims to characterize the pathological response and to examine its prognostic significance in these patients. Medical records of women with EOC treated in our institution from 2011 to 2016 were retrospectively identified. IDS specimens were reviewed by study pathologist and Chemotherapy Response Score (CRS), lymphocytic infiltration, necrosis and mitosis were assessed. 55 patients with EOC treated with NACT were identified and 48 had complete clinical and pathological data. Median age was 63 years. CRS assessed at omentum predicted PFS when adjusted for age, stage, debulking status (complete, optimal, suboptimal) and post IDS bevacizumab administration (mPFS CRS 1 vs 2 vs 3: 10.3–14–18.7 months 95% CI [7.4–15.7], [12.2–22.9], [13.5–31.3]). Presence of lymphocytic infiltration was associated with improved OS (log-rank test P = 0.015). Post IDS bevacizumab was associated with shorter PFS in patients with lymphocytic infiltration. BRCA status was known for 25 patients and presence of BRCA1/2 mutations was strongly correlated with lymphocytic infiltration (P = 0.011) but not CRS omentum (P = 0.926). Our study confirms the predictive value of CRS in EOC patients treated with NACT and IDS, but also demonstrates the prognostic significance of lymphocytic infiltration as well as its possible interaction with bevacizumab treatment. © 2020 Elsevier Inc.

Background:Metastatic RCC (mRCC) treatment has been revolutionized with 11 approved targeted agents. We report patterns of practice, outcomes and pharmacoeconomic analyses after the introduction of targeted therapy. Patients and methods: CRISIS was a retrospective multicenter study of mRCCpatients who received targeted therapy. Results were related to the start of 1st-line therapy, with a cut off at 1 January 2011 in order to depict the impact of increased availability of effective options. Results: 164 patients, were included. 70.1% and 44.5% received 2nd and 3rd-line therapy, respectively. More patients were treated in 2nd-line after 1 January 2011. After a median follow-up of 55.1 months, median progression-free (PFS) and overall survival (OS) were 10.7 (95% confidence intervals [CI]: 8.3–13.7), 7.3 (95% CI: 5.1–8.6), 5.8 (95% CI: 3.8–7.8) and 34 (95% CI: 28.5–39.8), 22.4 (95% CI: 16–32.1), 18.3 (95% CI: 12.4–26.4) months for first, second and third line, respectively. Efficacy of sunitinib and pazopanib in 1st-line were similar. The mean total cost/patient was 35,012.2 Euros (standard deviation [SD]: 28,971.5). Conclusions: Our study confirms previous real-world data suggesting that continuing advances in the treatment of mRCC produce favorable outcomes in everyday practice. Pharmacoeconomic analyses are important for cost-effective utilization of emerging novel therapies. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

Purpose: Cutaneous toxicities from novel anticancer treatments are an emerging problem in dermato-oncology. However, the prevalence of those toxicities and necessity of skin consultations are currently unknown. The purpose of our study was to perform an epidemiologic analysis of cutaneous toxicities that were referred to our cutaneous toxicity clinic in Athens, Greece. Methods: All patients examined at the oncodermatology department over a 42-month period were included. Gender, age, type of cancer, type of antineoplastic treatment, and type of toxicity were recorded and analyzed. Results: Four hundred fifty-nine patients (182 males, 277 females) with mean age (SD) 60.6 years (13.05) were included in the analysis. Six hundred seventy-two cutaneous toxicities were recorded. Chemotherapy-induced toxicities were the most commonly recorded incidents, with taxanes being the most commonly involved agent. Immune-related adverse events (IRAEs) have steadily increased over the past 3 years. Treatment modifications due to skin toxicities were more common in patients treated with targeted agents and immune checkpoint inhibitors than in those treated with chemotherapy. The toxicities that led to the most treatment modifications were acneiform eruptions and perionychias. The most common IRAEs recorded were psoriasis in 11 patients, followed by pruritus, macular rash, and lichenoid-type eruptions. In addition, 4 interesting cases of IRAEs are discussed. Conclusion: Antineoplastic treatments can lead to a wide range of cutaneous toxicities. Our study underlines the need for a multidisciplinary approach in oncologic patients. The dermatologists’ role is crucial in effectively managing those reactions and preventing antineoplastic drug dose adjustments or discontinuation of treatment. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

This clinical trial assessed the efficacy and toxicity of panitumumab combined with oxaliplatin and capecitabine as first-line treatment in KRAS exon 2 wild-type metastatic colorectal cancer (mCRC) patients. Patients with exon 2 KRAS wild-type mCRC received panitumumab 9 mg/Kg, oxaliplatin 130 mg/m2, and capecitabine 2000 mg/m2 repeated every 3 weeks. The primary endpoint was objective response rate (ORR, minimum 42 responses). We retrospectively assessed mutations in genes implicated in CRC with massively parallel sequencing; ERBB2 and EGFR amplification with fluorescence in situ hybridization, and tumor-infiltrating lymphocyte density. Among 78 patients enrolled, 45 (57.7%) completed 6 cycles. Most common grade 3–4 toxicities were skin rash (19.2%), diarrhea (18%), and neuropathy (6.4%). Among 5 (6.4%) potentially treatment-related deaths, 2 (2.6%) were characterized toxic. Objective response occurred in 43 (55.1%) of the patients (complete 6.4% and partial response 48.7%; stable 17.9% and progressive disease 7.7%), while 3.8% were non-evaluable and 15% discontinued their treatment early. Additional mutations in KRAS/NRAS/BRAF were found in 11/62 assessable (18%) tumors. After 51 months median follow-up, median progression-free (PFS) was 8.1 and overall survival 20.2 months, independently of KRAS/NRAS/BRAF or PI3K-pathway mutation status. Patients with TP53 mutations (n = 34; 55%), as well as those with left colon primary tumors (n = 66; 85%), had significantly better PFS, also confirmed in multivariate analysis. Although the clinical trial met its primary endpoint, according to the current standards, the efficacy and tolerability of the drug combination are considered insufficient. Extended genotyping yielded interesting results regarding the significance of TP53 mutations. ClinicalTrials.gov identifier: NCT01215539, Registration date: Sep 29, 2010. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

We address light propagation properties in complex media consisting of random distributions of lenses that have specific focusing properties. We present both analytical and numerical techniques that can be used to study emergent properties of light organization in these media. As light propagates, it experiences multiple scattering leading to the formation of light bundles in the form of branches; these are random yet occur systematically in the the medium, particularly in the weak scattering limit. On the other hand, in the strong scattering limit we find that coalescence of branches may lead to the formation of extreme waves of the "rogue wave" type. These waves appear at specific locations and arise in the linear as well as in the nonlinear regimes. We present both the weak and strong scattering limit and show that these complex phenomena can be studied numerically and analytically through simple models., This is a Chapter from the book: Quodons in Mica: Nonlinear localized traveling excitations in crystals. Springer Series in Materials Science

Introduction: The discovery of sensitizing mutations in epidermal growth factor receptor (EGFR) and the rapid development of EGFR tyrosine kinase inhibitors (TKIs) have substantially changed the management of non-small-cell lung cancer (NSCLC), leading to a tailored therapeutic approach for patients with advanced EGFR-mutant NSCLC. Gefitinib is an EGFR-directed TKI, approved by U.S. Food and Drug Administration (FDA) for the first-line treatment of patients with metastatic NSCLC whose tumors harbor specific EGFR gene mutations, as detected by an FDA-approved test. Areas covered: Here, we will focus on the approval of gefitinib as an effective EGFR-directed TKI option, describing the drug development to its currently established use. In parallel, based on the latest evidence, we will present its efficacy and its toxicity profile on selected NSCLC patients harboring specific EGFR driver mutations and we will try to reply to all open questions about gefitinib administration. Expert opinion: Gefitinib in NSCLC is an example of a more personalized approach to cancer therapeutics, where understanding of the molecular background of the cancer led to the appropriate evaluation of the drug into a selected patient population. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

Surface plasmon polaritons (SPPs) are coherent electromagnetic surface waves trapped on an insulator-conductor interface. The SPPs decay exponentially along the propagation due to conductor losses, restricting the SPPs propagation length to few microns. Gain materials can be used to counterbalance the aforementioned losses. We provide an exact expression for the gain, in terms of the optical properties of the interface, for which the losses are eliminated. In addition, we show that systems characterized by lossless SPP propagation are related to PT symmetric systems. Furthermore, we derive an analytical critical value of the gain describing a phase transition between lossless and prohibited SPPs propagation. The regime of the aforementioned propagation can be directed by the optical properties of the system under scrutiny. Finally, we perform COMSOL simulations verifying the theoretical findings.

Nonequilibrium, quasi-stationary states of a one-dimensional "hard" $\phi^4$ deterministic lattice, initially thermalized to a particular temperature, are investigated when brought into contact with a stochastic thermal bath at lower temperature. For lattice initial temperatures sufficiently higher than those of the bath, energy localization through the formation of nonlinear excitations of the breather type during the cooling process occurs. These breathers keep the nonlinear lattice away from thermal equilibrium for relatively long times. In the course of time some breathers are destroyed by fluctuations, allowing thus the lattice to reach another nonequilibrium state of lower energy. The number of breathers thus reduces in time; the last remaining breather, however, exhibits amazingly long life-time demonstrated by extensive numerical simulations using a quasi-symplectic integration algorithm. For the single-breather states we have calculated the lattice velocity distribution unveiling non-gaussian features describable in a closed functional form. Moreover, the influence of the coupling constant on the life-time of a single breather has been explored. The latter exhibits power-law behaviour as the coupling constant approaches the anticontinuous limit., Comment: 5 pages, 10 figures

The spatiotemporal complexity induced by perturbed initial excitations through the development of modulational instability in nonlinear lattices with or without disorder, may lead to the formation of very high amplitude, localized transient structures that can be named as extreme events. We analyze the statistics of the appearance of these collective events in two different universal lattice models; a one-dimensional nonlinear model that interpolates between the integrable Ablowitz-Ladik (AL) equation and the nonintegrable discrete nonlinear Schr\"odinger (DNLS) equation, and a two-dimensional disordered DNLS equation. In both cases, extreme events arise in the form of discrete rogue waves as a result of nonlinear interaction and rapid coalescence between mobile discrete breathers. In the former model, we find power-law dependence of the wave amplitude distribution and significant probability for the appearance of extreme events close to the integrable limit. In the latter model, more importantly, we find a transition in the the return time probability of extreme events from exponential to power-law regime. Weak nonlinearity and moderate levels of disorder, corresponding to weak chaos regime, favour the appearance of extreme events in that case., Comment: Invited Chapter in a Special Volume, World Scientific. 19 pages, 9 figures

We present numerical simulations for the propagation of surface plasmon polaritons in a dielectric-metal-dielectric waveguide using COMSOL multiphysics software. We show that the use of an active dielectric with gain that compensates metal absorption losses enhances substantially plasmon propagation. Furthermore, the introduction of the active material induces, for a specific gain value, a root in the imaginary part of the propagation constant leading to infinite propagation of the surface plasmon. The computational approaches analyzed in this work can be used to define and tune the optimal conditions for surface plasmon polariton amplification and propagation.

We investigate dynamical aspects of the discrete nonlinear Schr\"{o}dinger equation (DNLS) in finite lattices. Starting from a periodic chain with nearest neighbor interactions, we insert randomly links connecting distant pairs of sites across the lattice. Using localized initial conditions we focus on the time averaged probability of occupation of the initial site as a function of the degree of complexity of the lattice and nonlinearity. We observe that selftrapping occurs at increasingly larger values of the nonlinearity parameter as the lattice connectivity increases, while close to the fully coupled network limit, localization becomes more preferred. For nonlinearity values above a certain threshold we find a reentrant localization transition, viz. localization when the number of long distant bonds is small followed by delocalization and enhanced transport at intermediate bond numbers while close to the fully connected limit localization reappears., Comment: 5 pages, 5 figures

The existence and stability of dissipative discrete breathers (DDBs) in rf superconducting quantum interference device (SQUID) arrays in both one and two dimensions is investigated numerically. In an rf SQUID array, the nonlinearity which is intrinsic to each SQUID due to the presence of the Josephson junction (on-site nonlinearity), along with the weak coupling of each SQUID to its nearest neighbors through magnetic forces, result in the appearance of discrete breathers. We analyze several discrete breather excitations, both in one and two dimensions, which are subjected to unavoidable losses. These losses, however, are counter-balanced by an external flux source leading to linearly stable discrete breather structures up to relatively large coupling parameters. We show that DDB excitations may locally alter the magnetic response of array from paramagnetic to diamagnetic or vice versa, and that they are not destroyed by increasing the dimensionality., 9 pages, 13 figures, submitted to Nonlinear Phenomena in Complex Systems