Metropolitan quantum key distribution with silicon photonics

Photonic integrated circuits (PICs) provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) transmitter in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 950 kbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 106 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate PICs as a promising, scalable resource for future formation of metropolitan quantum-secure communications networks

Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice.

BACKGROUND & AIMS: It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence. METHODS: We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs. RESULTS: By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate). CONCLUSIONS: In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416

Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice.

BACKGROUND & AIMS: It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence. METHODS: We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs. RESULTS: By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate). CONCLUSIONS: In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416

Autofluorescence from NADH Conformations Associated with Different Metabolic Pathways Monitored Using Nanosecond-Gated Spectroscopy and Spectral Phasor Analysis

Cellular NADH conformation is increasingly recognized as an endogenous optical biomarker and metabolic indicator. Recently, we reported a real-time approach for tracking metabolism on the basis of the quantification of UV-excited autofluorescence spectrum shape. Here, we use nanosecond-gated spectral acquisition, combined with spectrum-shape quantification, to monitor the long excited-state lifetime autofluorescence (usually associated with protein-bound NADH conformations) separately from the autofluorescence signal as a whole. We observe that the autofluorescence response induced by two NADH-oxidation inhibitorscyanide and ethanolare similar in Saccharomyces cerevisiae when monitored using time-integrated detection but easily distinguished using time-gated detection. Results are consistent with the observation of multiple NADH conformations as assessed using spectral phasor analysis. Further, because well-known oxidation inhibitors are used, changes in spectrum shape can be associated with NADH conformations involved in the different metabolic pathways, giving bioanalytic utility to the spectral responses

Influence of thymol and silver nanoparticles on the degradation of poly(lactic acid) based nanocomposites: thermal and morphological properties

Biopolymers, such as poly(lactic acid) (PLA), have been proposed as environmentally-friendly alternatives in applications such as food packaging. In this work, silver nanoparticles and thymol were used as active additives in PLA matrices, combining the antibacterial activity of silver with the antioxidant performance of thymol. The combined action of both additives influenced PLA thermal degradation in ternary systems. DSC results showed that the addition of thymol resulted in a clear decrease of the glass transition temperature (Tg) of PLA, suggesting its plasticizing effect in PLA matrices. Slight modifications in mechanical properties of dog-bone bars were also observed after the addition of the active components, especially in the elastic modulus. FESEM analyses showed the good distribution of active additives through the PLA matrix, obtaining homogenous surfaces and highlighting the presence of silver nanoparticles successfully embedded into the bulk matrix. Degradation of these PLA-based nanocomposites with thymol and silver nanoparticles in composting conditions indicated that the inherent biodegradable character of this biopolymer was improved after this modification. The obtained nanocomposites showed suitable properties to be used as biodegradable active-food packaging systems with antioxidant and antimicrobial effects.Authors would like to thank Spanish Ministry of Economy and Competitiveness for financial support (MAT-2011-28468-C02-01). Moreover, Marina Ramos would like to thank University of Alicante (Spain) for UAFPU2011-48539721S predoctoral research grant