Effectiveness of Machine Learning in Assessing QoT Impairments of Photonics Integrated Circuits to Reduce System Margin

We propose machine learning technique for assessment of QoT impairments of integrated circuits. We consider margin reduction problem applied to a switching component. Overall results and data sets for machine-learning training are obtained by leveraging the integrated software environment of the Synopsys Photonic Design Suite

Abstracting network elements from mask layout to network management: a case study

Using the vertical integration of the Synopsys environment, we analyze a 2 2 integrated optical switch obtaining a layer-0 abstraction used to analyze the impact of the design options on transmission performances of a PM-64QAM 600G channel in multi-hop routing in meshed optical networks. The optical switch is designed targeting the Analog Photonics Process Design Kit. The QoT degradation depending on the design option and on the choice for the transmission technique is assessed, taking into account the number of traversed switches. In addition, different routing techniques for the integrated optical waveguides of the 2x2 switches are investigated in terms of system performances. The reported analysis is an example of comprehensive investigation carried out by abstracting the network elements starting from the component design up to the networking management. This approach is today mandatory to enable the maximum capacity in state-of-the art optical networks. To face this challenging problem, Synopsys proposes a vertically integrated software environment for the design of optical communication systems with photonic integrated circuits: it is the integration of OptSim c -optical communication system, OptSim Circuit -schematic-driven photonic circuit, OptoDesigner c -mask layout, and RSoft component design tools. These tools have proven to be reliable aids to virtually designing and estimating the performance of optical transmission systems and photonic chips

Safety and Efficacy of Aminolevulinic Acid 10% Topical Gel versus Aminolevulinic Acid 20% Topical Solution Followed by Blue-light Photodynamic Therapy for the Treatment of Actinic Keratosis on the Face and Scalp: A Randomized, Double-blind Study

Objective: Photodynamic therapy (PDT) using 10% 5-aminolevulinic acid (ALA) gel (GEL) has been shown to be highly effective for treating actinic keratosis (AK) but has only been studied using red-light activation. The goal of this study was to compare GEL and a 20% ALA solution (SOL) using blue-light activation under typical clinical conditions. Design: This double-blind, split-face study randomized subjects to GEL or SOL application to contiguous 25cm 2 fields containing 4 to 8 AK lesions on either side of the face or scalp (no curettage, 1-hour incubation, no occlusion) followed by blue light exposure (1,000 seconds, 417nm, 10J/cm 2 ). Participants: Forty adult subjects were treated on either the face (n=20) or scalp (n=20). Measurements: Primary outcomes included change in baseline AK lesions. Secondary outcomes included local skin reaction (LSR) scores and visual analog scale (VAS) pain scores. Results: Lesions treated with GEL were 97.1 percent cleared at Day 84 versus 94.9 percent for lesions treated with SOL ( p <0.001 vs. baseline); additionally, 86.8 percent of areas treated with GEL and 78.9 percent of areas treated with SOL showed 100-percent clearance ( p <0.001 vs. baseline). Mean VAS pain scores were minimal for the SOL and the GEL (25.4 vs. 28.5 and 16.1 vs. 19.3, respectively; p =nonsignificant). At three days after the first and second treatments, more significant LSRs were noted in areas treated with SOL, including erythema, crusting, and scaling/dryness. There were no significant adverse events observed. Conclusion: GEL was equivalent to SOL for clearing AK lesions on the face and scalp with blue-light PDT; however, SOL caused significantly more local skin reactions

Simulation of silicon photonic coherent PM-QPSK transceivers using microring modulators

Silicon photonic components are key enablers for low-cost, compact, and reduced power-consumption coherent transceivers. This paper discusses models used to analyze the performance of silicon photonic ring modulators in coherent links, and presents simulation results for 32- and 16-Gbaud PM-QPSK back-to-back transceivers incorporating these modulators in comparison with designs using LiNbO3 MZMs. While the penalty at 32 Gbaud is high, at 16 Gbaud the ring modulator performance approaches that of the MZM, with a sensitivity penalty of only 1.3 dB. Our results also show the strong temperature sensitivity of the ring modulator

High risk, high reward: An analysis of outcomes for candidates awaiting hepatic re-transplantation

Background. Liver re-transplantation (re-OLT) remains the only feasible option for patients with graft failure following liver transplantation. Sparse resources and a growing waitlist mandate that available grafts are allocated properly. We studied the differences in patient demographics, characteristics, and survival for those listed for re-OLT in a region with prolonged wait times.Material and methods. We performed a single-center retrospective study, from 2005 to 2013, of adult candidates listed for liver re-OLT at a tertiary care center within United Network for Organ Sharing (UNOS) region 1.Results. Of the 48 patients listed for re-OLT, 1(2%) improved while waiting, 14(29%) died while waiting, and 33(69%) underwent re-OLT. Those re-transplanted represented 11% of the center’s adult liver transplant volume during the same time period. Comparing those who died while waiting to those who achieved re-OLT, there was no significant difference in age (median 52 vs. 48 years, p=0.56) or MELD at second listing (median 29 vs. 26, p = 0.90). Waitlisted candidates who failed to achieve re-transplant died on average of 15.5 days (IQR 36 days) days after re-listing. Those re-transplanted achieved 3-year survival of 70% and there was no significant difference in 3-year survival of those re-transplanted within or beyond 90 days of first transplant (70% vs. 69.5%, p = 0.28).Conclusions. In conclusion, re-OLT is the only viable option for candidates with nonreversible liver graft failure. Inability to achieve re-OLT leads to nearly assured and expeditious death. Despite technical challenges, in experienced hands excellent long term survival following re-OLT can be achieved