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The time-domain balanced homodyne detector (TBHD) is critical component in continuous-variable quantum key distribution (CVQKD). The shot-noise-limited attribute of a TBHD depends on the whole spectrum of detector, in contrast to a frequency-domain balanced homodyne detector that focuses only on part of the spectrum. We propose a method for accurate calibration of the shot-noise-limited attribute of the TBHD by overlapping the gain lines of the TBHD and an integrated photodetector. The overlapping of two lines indicates that the detector is indeed shot noise limited, which is crucial to the security of CVQKD. Experimentally, we use this method to obtain a calibration error of ±1‰. Theoretical analysis showed that the CVQKD performance is very sensitive to calibration errors of shot noise, and proper countermeasures should be employed to eliminate this issue. The presented methods are expected to contribute to CVQKD security and TBHD standardization.

Background: Alzheimer’s disease (AD), a neurodegenerative disease showing multiple complex pathomechanism alterations, has affected the normal life of many old people. It is urgent to find an effective medicine for AD. Ginsenoside Rb1 (Rb1) is the main component of panax notoginseng saponins, a famous Chinese herbal medicine, and is expected to be a useful drug in the treatment of AD. This study mainly explored the potential effects of Rb1 in model of AD in vivo and in vitro, and investigated the possible mechanisms. Materials and methods: We studied the neuroprotective effect of Rb1 in transgenic mouse animal model and cell AD model in vitro. The cognitive function of APP/PS1 mice was measured in Morris water maze and Novel Object Recognition. Electrophysiological patch clamp recording and electrophysiology were used to nerve excitability. Further, the expression of proteins of Nav1.2 and Nav1.6 were used by Western blot. Results: We found that Rb1 treatment significantly improved the cognitive and memory loss, and reversed the hyperexcitability by altering the expressions of Nav1.2 and Nav1.6 of APP/PS1 mice. Further, Rb1 improved the hyperexcitability induced by Aβ1-42-injured neurons, which might be associated with alteration of the expressions of Nav1.2 and Nav1.6. As we expect, Rb1 attenuated Aβ1-42-induced injury in primary neurons. Conclusion: Our data showed that Rb1 played a critical role in improvement of the cognitive deficit and abnormal excitability of AD by regulating Nav1.2 and Nav1.6 expressions. Thus, Rb1 shows protective effects on AD models and may be a potential candidate for AD treatment.

Background Infections still represent the main factors influencing morbidity and mortality following liver transplantation. This study is to evaluate the incidence and risk factors for infection and survival after liver transplantation. Methods We retrospectively examined medical records in 210 recipients who underwent liver transplantation between April 2015 and October 2017 in our center. Results During the median follow-up days of 214, the incidence of infection after liver transplantation was 46.7% (n=98): namely, pneumonia (43.4%), biliary tract infection (21.9%) and peritonitis (21.4%). Among the pathogens in pneumonia, the most frequently isolated was Acinetobacter baumanii (23.5%) and Klebsiella pneumoniae (21.1%). For biliary tract infection, the first rank was Strenotrophomonas maltophilia (14.0%) and then Klebsiella pneumoniae (11.6%). Pseudomonas aeruginosa, Strenotrophomonas maltophilia, and Klebsiella pneumoniae accounted for 21.4%, 11.9% and 11.9% of pathogens in peritonitis, respectively. The independent risk factors for infection after liver transplantation are model for end-stage liver disease (MELD) or pediatric end-stage liver disease (PELD) score, total blood loss in operation and duration of drainage tube. All-cause mortality was 11.0% (n=23). The prognostic factors for postoperative infection in transplant recipients are infection, especially pneumonia within 2 weeks before transplantation, complication with impaired renal function and higher MELD or PELD score after 7 days of transplantation. Kaplan–Meier curves of survival showed that recipients with infection within 2 weeks before transplantation had a significantly lower cumulative survival rate compared with those without infection (66.7% vs 91.9%, HR=4.480, 95% CI, 3.377-47.85; p