InSb all-dielectric metasurface for ultrahigh efficient Si-based mid-infrared detection.

Mid-infrared (MIR) Si-based optoelectronics has wide potential applications, and its design requires simultaneous consideration of device performance optimization and the feasibility of heterogeneous integration. The emerging interest in all-dielectric metasurfaces for optoelectronic applications stems from their exceptional ability to manipulate light. In this Letter, we present our research on an InSb all-dielectric metasurface designed to achieve ultrahigh absorptivity within the 5-5.5 µm wavelength range. By integrating an InSb nanodisk array layer on a Si platform using wafer bonding and heteroepitaxial growth, we demonstrate three kinds of metasurface with high absorptivity of 98.36%, 99.28%, and 99.18%. The enhanced absorption is mainly contributed by the Kerker effect and the anapole state and the peak, with the added flexibility of tuning both the peak and bandwidth of absorption by altering the metasurface parameters. Our findings provide an alternative scheme to develop high-performance detectors and absorbers for MIR silicon photonics.

Dynamically tunable multi-band quasi-permittivity-asymmetric BIC in the GST225 metasurface.

Bound states in the continuum (BICs) on metasurfaces have garnered significant interest for their ultrahigh Q-factor potential in sensing applications. Reconfigurability and multi-band resonance are highly desirable for sensing systems. In this work, we introduce a metasurface comprising four nanocubes with different permittivity asymmetries, which can be dynamically adjusted using Ge2Sb2Te5 (GST225), a phase-change material, in the near-infrared (NIR) region. Additionally, a simulation for a liquid molecule sensor based on the metasurface shows a sensitivity of 1017 nm/RIU. This research introduces a novel, to the best of our knowledge, approach for designing multi-band, dynamically tunable quasi-BIC metasurfaces, which are good candidates for tunable, high-sensitivity biochemical sensing and nonlinear optics applications.

Giant strong coupling in a Q-BICs' tetramer metasurface.

Due to their ultrahigh Q-factor and small mode volume, bound states in the continuum (BICs) are intriguing for the fundamental study of the strong coupling regime. However, the strong coupling generated by BICs in one metasurface is not always strong enough, which highly limits its efficiency in applications. In this work, we realize a giant strong coupling of at most 60 meV in a quasi-BICs' (Q-BICs) tetramer metasurface composed of four Si cylinders with two different sets of diagonal lengths. The Q-BICs are induced from two types of electric quadrupole (EQ), for which detuning can be flexibly controlled by manipulating the C4v symmetry breaking Δd. The giant Rabi splitting in our proposed metasurface performs more than 15 times of the previous works, which provides more possibilities for important nonlinear and quantum applications, such as nanolaser and quantum optics.

Dedifferentiation of human epidermal melanocytes in vitro by long-term trypsinization.

Human epidermal melanocytes can be induced to form melanocyte spheroids and revert to immature characteristics by long-term trypsinization (LTT). To further explore the biological characteristics of melanocytes after LTT and to study the underlying mechanism. Melanocytes were subjected to long-term (2 h) trypsinization in this study, after which their viability, proliferation and autophagy were characterized. The expression of melanocyte markers [human melanoma black45 (HMB45), tyrosinase (TYR) and Nestin] was detected and relative expression levels of mRNAs encoding TYR, Nestin, c-Kit and microphthalmia-associated transcription factor (MITF) were determined. After LTT, more short spindle-shaped melanocytes appeared and viability assays demonstrated that most melanocytes survived that treatment but had decreased proliferation rates compared to the untreated controls. There was a significant increase in autophagy of melanocytes after LTT and the expression of TYR was decreased compared with untreated control melanocytes. There were no significant differences in the expression of HMB45 or Nestin between the two groups. Compared with untreated melanocytes, levels of message ribonucleic acid (mRNAs) encoding TYR, c-Kit and MITF were decreased after LTT, while Nestin mRNA levels were increased. These results clarified that Long-term treatment with trypsin causes the dedifferentiation of mature epidermal melanocytes in vitro.

The tolerance of human epidermal cells to trypsinization in vitro.

To characterize the tolerance of different types of human epidermal cells to trypsinization in vitro and develop a new method to separate and purify melanocytes according to their tolerance to trypsinization. Epidermal cells were obtained by separating the epidermis from human foreskins. Some of those cells were used for routine culture, and then were subjected to differential trypsin digestion. The remaining epidermal cells were resuspended in a 0.25% trypsin solution and then were neutralized by the addition of bovine serum at different time points. Immunofluorescence staining of HMB45, K15 and vimentin was used to identify melanocytes, keratinocytes and fibroblasts, respectively. We found that Keratinocytes, melanocytes and fibroblasts are primary cells obtained from conventional cultures of human skin. Purified keratinocytes and melanocytes can be obtained by conventional differential trypsin digestion, but fibroblasts in the melanocyte population quickly gain a survival advantage after passage. With longer trypsin digestion times, the number of adherent cells decreased, the time required for cell attachment increased, and the proportion of melanocytes increased. There were no obvious keratinocytes in cell populations obtained after 12 h of trypsinization of epidermal cells, and more short spindle-shaped melanocytes appeared, all of which were HMB45-positive. In conclusion, the tolerance of human epidermal melanocytes to trypsinization in vitro was better than epidermal keratinocytes, and that property can be used to purify melanocytes and was better than traditional differential trypsin digestion. The morphology of cells that survived the long-term trypsin digestion changed and they had good proliferative activity, but seemed to be more immature.

Efficacy and Safety of Moderate-Intensity Continuous Training on the Improvement of Cardiopulmonary Function in Patients After Transcatheter Aortic Valve Replacement (ENERGY): A Randomized Controlled Trial.

OBJECTIVES: To investigate the effect of moderate-intensity continuous training (MICT) on the improvement of cardiopulmonary function for patients undergoing transcatheter aortic valve replacement (TAVR). DESIGN: Randomized controlled study. SETTING AND PARTICIPANTS: Between August 20, 2021, and February 28, 2022, a total of 66 patients after TAVR were screened for inclusion and randomly divided into the MICT and control groups at a ratio of 1:1. MICT was scheduled 3 times per week for 3 months in the intervention group. Patients in the control group received one-time advice on physical activity according to the current guideline. METHODS: The primary endpoint was the 3-month change in peak oxygen consumption (peak VO2) assessed by cardiopulmonary exercise testing. The secondary endpoints included the 3-month change in 6-minute walk test (6MWT), the 12-Item Short Form Health Survey (SF-12), New York Heart Association (NYHA) class, echocardiographic parameters, and laboratory parameters. RESULTS: After 3 months, the change in peak VO2 was higher in the MICT group than that in the control group (1.63 mL/kg/min, 95% CI 0.58-2.67, P = .003). Change in 6MWT (21.55 m, 95% CI 0.38-42.71, P = .046) was higher in the MICT group compared with the control group. A significant change in favor of MICT was also observed for low-density lipoprotein cholesterol (-0.62 mmol/L, 95% CI -1.00 to -0.23, P = .002). However, there were no significant changes in other echocardiographic indices, laboratory parameters, and SF-12 between the 2 groups (all P > .05). CONCLUSIONS AND IMPLICATIONS: MICT had a positive effect on the cardiopulmonary function and physical capacity of patients after TAVR.

Serum Metabolomics Revealed the Differential Metabolic Pathway in Calves with Severe Clinical Diarrhea Symptoms.

The complex etiology, higher morbidity and mortality, poor prognosis, and expensive cost of calf diarrhea have made it a catastrophic disease in the dairy industry. This study aims to assess the biomarkers in calves with diarrhea and to predict the biomarkers related to the pathway. As subjects, nine calves with diarrhea and nine healthy calves were enrolled, according to strict enrollment criteria. The serum metabolites were detected by a liquid chromatographic tandem mass spectrometry (LC-MS/MS), and then analyzed by online multivariate statistical analysis software to further screen the biomarkers. In addition, the biomarkers involved in the metabolic pathways of calves with diarrhea and healthy calves were analyzed. In the serum of calves with diarrhea, nine biomarkers were found to which several biomarkers exhibited a certain relation. Moreover, these biomarkers were involved in important metabolic pathways, including protein digestion and absorption, ABC transporters, aminoacyl-tRNA biosynthesis, mineral absorption, and fatty acid biosynthesis. All these findings suggested that the imbalance of these markers was closely related to the occurrence and development of calf diarrhea. The targeted regulation of metabolic pathways involved in these biomarkers may facilitate the diagnosis, treatment, and discussion of the mechanism of calf diarrhea.

Differences in the intestinal microbiota between uninfected piglets and piglets infected with porcine epidemic diarrhea virus.

Porcine epidemic diarrhea, a disastrous gastrointestinal disease, causes great financial losses due to its high infectivity, morbidity and mortality in suckling piglets despite the development and application of various vaccines. In this study, high-throughput sequencing was used to explore differences in the intestinal microbiota between uninfected piglets and piglets infected with porcine epidemic diarrhea virus (PEDV). The results revealed that the small intestinal microbiota of suckling piglets infected with PEDV showed low diversity and was dominated by Proteobacteria (49.1%). Additionally, the composition of the small intestinal microbiota of sucking piglets infected with PEDV showed marked differences from that of the uninfected piglets. Some of the taxa showing differences in abundance between uninfected piglets and piglets infected with PEDV were associated with cellular transport and catabolism, energy metabolism, the biosynthesis of other secondary metabolites, and amino acid metabolism as determined through the prediction of microbial function based on the bacterial 16S rRNA gene. Therefore, adjusting the intestinal microbiota might be a promising method for the prevention or treatment of PEDV.