Silicon photonics integrated dynamic polarization controller

We designed and demonstrated experimentally a silicon photonics integrated dynamic polarization controller. The overall size of the dynamic polarization controller on chip is 2.830 mm × 0.210 mm × 1 mm. The modulation bandwidth is 30 kHz. By using a variable step simulated annealing approach, we achieve a dynamic polarization extinction ratio greater than 25 dB. A numerical simulation method was used to optimize the relevant parameters of the dynamic polarization controller. It is expected that the dynamic polarization controller can be utilized in fiber communication systems or silicon photonics integrated quantum communication systems to minimize the size and decrease the cost further.This work was supported by the Aeronautical Science Foundation of China (No. 20200020115001), National Natural Science Foundation of China (No. 62175138), Key Research and Development Program of Guangdong Province (No. 2020B0303040002), Shanxi 1331KSC, and Open Project of the State Key Laboratory of Quantum Optics and Quantum Optics Devices of Shanxi University (No. KF202006)

Compact Quantum Random Number Generator Based on a Laser Diode and a Hybrid Chip with Integrated Silicon Photonics

In this study, a compact and low-power-consumption quantum random number generator (QRNG) based on a laser diode and a hybrid chip with integrated silicon photonics is proposed and verified experimentally. The hybrid chip’s size is 8.8 × 2.6 × 1 mm3, and the power of the entropy source is 80 mW. A common-mode rejection ratio greater than 40 dB was achieved using an optimized 1 × 2 multimode interferometer structure. A method for optimizing the quantum-to-classical noise ratio is presented. A quantum-to-classical noise ratio of approximately 9 dB was achieved when the photoelectron current is 1 μA using a balance homodyne detector with a high dark current GeSi photodiode. The proposed QRNG has the potential for use in scenarios of moderate MHz random number generation speed, with low power, small volume, and low cost prioritized

Safety, Immunogenicity and Lot-to-Lot Consistency of Sabin-Strain Inactivated Poliovirus Vaccine in 2-Month-Old Infants: A Double-Blind, Randomized Phase III Trial

Background: The Sabin-strain-based inactivated poliovirus vaccine (sIPV) plays an important role in poliomyelitis eradication in developing countries. As part of the phase III clinical development program, this study aimed to evaluate the safety, immunogenicity and lot-to-lot consistency of the sIPV in 2-month-old infants. Method: We conducted a phase III, randomized, double-blind, positive-controlled trial in which 1300 healthy infants were randomly assigned to four groups in a 1:1:1:1 ratio to receive one of the three lots of the sIPV or the control IPV at 2, 3 and 4 months of age. Serum samples were collected before the first dose and 30 days after the third dose of vaccination to assess the immunogenicity. Solicited local and systemic reactions were recorded within 7 days and unsolicited adverse events within 30 days after each vaccination. Results: Of the 1300 randomized infants, 1190 infants completed the study and were included in the per-protocol population. The seroconversion rates in the three lots of the sIPV were 95.67%, 97.03% and 95.59%, respectively, for type 1; 94.33%, 93.73% and 92.88%, respectively, for type 2; and 98.67%, 99.67% and 99.32%, respectively, for type 3. The ratios of GMTs for poliovirus types 1, 2 and 3 of each pair of lots were all between 0.67 and 1.50, therefore meeting the predefined immunological equivalence criteria. For the seroconversion rate of poliovirus types 1, 2 and 3, the pooled sIPV group was non-inferior to the IPV group. The incidence of solicited and unsolicited adverse reactions (ARs) was similar in the pooled sIPV lots and the IPV group, and most of them were mild to moderate in severity. Non-vaccine-related serious adverse events (SAEs) were reported. Conclusions: Three consecutive lots of sIPV demonstrated robust and consistent immunogenicity. The safety and tolerability of the sIPV was acceptable and similar to that of the IPV

Design, Synthesis, and Optoelectronic Properties of Dendrimeric Pt(II) Complexes and Their Ability to Inhibit Intermolecular Interaction

Dendrimeric Pt­(II) complexes [(C^∧N)­Pt­(dpm)] and [Pt­(C^∧N)₂] (Hdpm = dipivaloylmethane, HC^∧N = 1,2-diphenylbenzoimidazole and its derivatives containing the carbazole dendrons) have been synthesized and characterized systematically. All of the complexes display green emission in the range of 495–535 nm that originated from the 360–440 nm absorption bands, which are assigned to dπ­(Pt)→π*­(L) metal-to-ligand charge transfer (MLCT) mixed with intraligand π­(L)→π*­(L) transition. Solution photoluminescence quantum yield (φ_p 0.26–0.31) of the heteroleptic complexes [(C^∧N)­Pt­(dpm)] obviously increases when compared with that of complex [(C^∧N)­Pt­(acac)]. Organic light-emitting diode devices based on these Pt­(II) complexes with a multilayer configuration were fabricated and gave desirable electroluminescent (EL) performances, such as non- or less red-shifted EL spectra, in comparison with the photoluminescence spectra and slow efficiency roll-off with increasing brightness or current density. Complex [(<i>t</i>-BuCzCzPBI)­Pt­(dpm)] (where <i>t</i>-BuCzCzPBI = 1-(4-(3,6-di-(3,6-di-t-butyl-carbazol-9-yl))­carbazol-9-yl)­phenyl-2-phenylbenzoimidazole) showed the best performance, with a maximum current efficiency of 29.31 cd/A and a maximum external quantum efficiency (EQE) of 9.04% among the fabricated devices. Likewise, for homoleptic [Pt­(<i>t</i>-BuCzCzPBI)₂] dendrimer, the powder φ_p (0.14) and maximum EQE (0.74%) improve by 7 and 7.4 times, respectively, as high as they do for nondendrimeric [Pt­(1,2-diphenylbenzoimidazole)₂] (0.02, 0.10%), although its efficiency is still lower than that of the heteroleptic counterpart due to the severely distorted square-planar geometry of the emitting core. These results reveal that large steric hindrance from ancillary ligand (dpm) or the homoleptic conformation can effectively inhibit intermolecular interaction for these dendrimeric Pt­(II) complexes

Safety, immunogenicity, and efficacy of an mRNA COVID-19 vaccine (RQ3013) given as the fourth booster following three doses of inactivated vaccines: a double-blinded, randomised, controlled, phase 3b trialResearch in context

Summary: Background: Heterologous vaccine schedules have been recommended to provide superior immunity and protection against emergent SARS-CoV-2 variants of concern. We aimed to evaluate the safety, immunogenicity, and efficacy of an mRNA COVID-19 vaccine RQ3013 compared with adenoviral vectored vaccine Ad5-nCoV and protein subunit vaccine ZF2001 as the fourth dose in adults primed with three doses of inactivated vaccines in China. Methods: We conducted a double-blinded, randomised, controlled, phase 3b trial among healthy Chinese adults at Lancang County, Yunnan, China. Adults who had received three doses of inactivated COVID-19 vaccines at least 6 months prior were randomly allocated (3:1:1) to receive heterologous boosters with RQ3013, Ad5-nCoV, or ZF2001. We assessed safety within 28 days post boost and the serum geometric mean titres (GMTs) of neutralising antibodies (NAbs) against the live SARS-CoV-2 omicron variant BA.5 on day 14 post-boost. We used Poisson regression to assess the vaccine efficacy against the first episode of virologically confirmed symptomatic COVID-19 occurring at least 7 days post boost. Subgroup analyses categorized by age and sex were also performed for safety and immunogenicity outcomes. This trial has been registered with the Chinese Clinical Trial Registry (ChiCTR2200065281) and is now complete. Findings: Between December 12 and December 18, 2022, a total of 1382 adults were screened, and 1250 were enrolled and randomly assigned to receive one dose of RQ3013 (n = 750), Ad5-nCoV (n = 250), or ZF2001 (n = 250). Although solicited adverse reactions within 28 days post boost were more frequent in the RQ3013 group (175 [23.3%]) compared to the control groups (24 [9.6%] in both the Ad5-nCOV and ZF2001 groups, P  0.05). On day 14 post-boost, RQ3013 (GMT 69.14, 95% CI 47.90–99.81) elicited 4.8-fold and 5.6-fold higher concentrations of NAbs against BA.5 than did Ad5-nCoV (14.37, 7.78–26.56) and ZF2001 (12.21, 5.13–29.06), respectively. On day 28 post-boost, RQ3013 demonstrated a relative efficacy of 62.2% (95% CI 13.7–83.1, P = 0.02) compared to Ad5-nCoV, and of 69.0% (33.5–85.7, P = 0.002) compared to ZF2001. Interpretation: The administrations of all the three heterologous boosters were well tolerated. The heterologous prime-boost regimen with RQ3013 elicited superior immune responses and demonstrated better protection against symptomatic SARS-CoV-2 infections compared with Ad5-nCoV or ZF2001, supporting the use of RQ3013 as a booster vaccination in adults. Funding: Yunnan Province Science and Technology Department (grant no.202302AA310047)