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Abstract Directional emission of photoluminescence despite its incoherence is an attractive technique for light-emitting fields and nanophotonics. Optical metasurfaces provide a promising route for wavefront engineering at the subwavelength scale, enabling the feasibility of unidirectional emission. However, current directional emission strategies are mostly based on static metasurfaces, and it remains a challenge to achieve unidirectional emissions tuning with high performance. Here, we demonstrate quantum dots-hydrogel integrated gratings for actively switchable unidirectional emission with simultaneously a narrow divergence angle less than 1.5° and a large diffraction angle greater than 45°. We further demonstrate that the grating efficiency alteration leads to a more than 7-fold tuning of emission intensity at diffraction order due to the variation of hydrogel morphology subject to change in ambient humidity. Our proposed switchable emission strategy can promote technologies of active light-emitting devices for radiation control and optical imaging.

Abstract Optical frequency combs provide a powerful tool for precise measurement of the optical frequency, holding significant importance in fields such as spectroscopy, optical communication and optical clock. The frequency stability of the comb line determines the precision of the frequency measurement, but the delicate interplay between high precision, low power consumption and integration still needs to be optimized. To this aim, here we demonstrate a frequency measurement scheme based on a fully stabilized electro-optic comb, in which the pump laser frequency and repetition rate are independently locked to the atomic transition and microwave signal. The measurement precision of the demonstrated wavemeter can reach sub-kHz-level, and the parallel measurement of multiple wavelengths can be performed. Therefore, by combining the technical scheme reported here with advanced integrated functional devices, our system is expected to provide a feasible solution for chip-scale frequency precision measurement and reference.

Microcombs are vulnerable to the environmental perturbations. Here, the authors propose a universal mechanism to fully control the microcombs. Based this reconfigurable microsoliton, a wavemeter with a precision of kHz is demonstrated.

ObjectiveRecent studies suggest air pollution as an underlying factor to kidney disease. However, there is still limited knowledge about the short-term correlation between glomerulonephritis (GN) and air pollution. Thus, we aim to fill this research gap by investigating the short-term correlation between GN clinical visits and air pollution exposure.MethodsBetween 2015 and 2019, daily GN visit data from two grade A tertiary hospitals in Hefei City were collected, along with corresponding air pollution and meteorological data. A generalized linear model integrated with a distributed lag nonlinear model was employed to analyze the relationship between GN visits and air pollutants. Moreover, we incorporated a dual pollutant model to account for the combined effects of multiple pollutants. Furthermore, subgroup analyses were performed to identify vulnerable populations based on gender, age, and season.ResultsThe association between 23,475 GN visits and air pollutants was assessed, and significant positive associations were found between CO and NO2 exposure and GN visit risk. The single-day lagged effect model for CO showed increased risks for GN visits from lag0 (RR: 1.129, 95% CI: 1.031–1.236) to lag2 (RR: 1.034, 95% CI: 1.011–1.022), with the highest risk at lag0. In contrast, NO2 displayed a more persistent impact (lag1–lag4) on GN visit risk, peaking at lag2 (RR: 1.017, 95% CI: 1.011–1.022). Within the dual-pollutant model, the significance persisted for both CO and NO2 after adjusting for each other. Subgroup analyses showed that the cumulative harm of CO was greater in the cold-season and older adult groups. Meanwhile, the female group was more vulnerable to the harmful effects of cumulative exposure to NO2.ConclusionOur study indicated that CO and NO2 exposure can raise the risk of GN visits, and female and older adult populations exhibited greater susceptibility.

Cross-component linear model (CCLM) prediction in H.266/versatile video coding (VVC) can improve the compression efficiency.There exists high correlation between luma and chroma components while the correlation is difficult to be modeled explicitly.An algorithm for neural network based cross-component prediction (NNCCP) was proposed where reference pixels with high correlation were selected according to the luma difference between the reference pixels and the pixel to be predicted.Based on the high-correlated reference pixels and the luma difference, the predicted chroma was obtained based on lightweight fully connected networks.Experimental results demonstrate that the proposed algorithm can achieve 0.27%, 1.54%, and 1.84% bitrate savings for luma and chroma components, compared with the VVC test model 10.0 (VTM10.0).Besides, a unified network can be employed to blocks with different sizes and different quantization parameters.

In fish, the immune system plays a crucial role in defending against pathogen-induced infections. The interleukin 17 (IL-17) family, which is a well-studied class of cytokines, serves as a key component of the immune response against external pathogens. In this research, four IL-17 ligands (IL-17A/F1, IL-17B, IL-17C and IL-17D) and one receptor (IL-17RB) genes were identified from spotted sea bass (Lateolabrax maculatus). Alignment analysis showed that the C-terminal region of IL-17 ligands in spotted sea bass was highly conserved. The expression of the IL-17 ligand and receptor genes differed in unstimulated tissues. To investigate the impact of various factors on the immune response of spotted sea bass, we assessed the effect of lipopolysaccharide (LPS), polyinosinic–polycytidylic acid [poly (I:C)] and Edwardsiella tarda treatment on the IL-17 ligands and receptor responses. Our results reveal that the expression of the IL-17 ligand and receptor transcripts is modulated by LPS, poly (I:C) and E. tarda, indicating their significant role in the immune system.

Dissipative Kerr solitons (DKS)s offer an integrated platform for broad spectrum coverage, which is suitable for the high sensitivity spectroscopy. However, the large linespacing of the soliton comb limits the spectroscopy detection resolution. We overcome this limitation by modulating the soliton comb lines through an external EOM with a tunable RF source. By locking the pump laser to a reference cavity, the linewidth of the pump laser was compressed from $1.13\:\mathrm{MHz}$ to $72\:\mathrm{kHz}$, leading to the silimar linewidth of comb lines and showing a frequency resolution of hundreds of $kHz$. Based on the scanned microcomb, we measured the absorption spectra of a gas cell and the high-Q optical modes in the microcavity, with a fast scanning speed of $\mathrm{16\,\,\mathrm{GHz/\mu s}}$. The scanning comb allows the spectroscopy measurement to cover the whole comb mode spectrum over THz bandwidth. Our setup holds great potential for simple, robust spectroscopy measurement.