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Vortex beams carrying orbital angular momentum (OAM) open a new perspective in various terahertz research. Multichannel and divergence controllable terahertz vortex beam generation holds the key to promoting the development of OAM related terahertz research. Here, we introduced and experimentally demonstrated quasi-perfect vortex beam (Q-PVB) with a controllable divergence angle independent of the topological charge and multichannel Q-PVBs generation with all-dielectric multifunctional metasurfaces. By superimposing specific phase functions together into the metasurfaces, multiple vortex beams and four-channel Q-PVBs with different topological charges are generated as well as focused at separated positions. High resolution characterization of terahertz electric field shows the good quality and broadband properties of Q-PVBs. Interestingly, compared with conventional perfect vortex beam; Q-PVB displays a smaller divergence angle and thinner ring width. The metasurfaces proposed here provide a promising avenue to realize multichannel vortex beams generation in compact terahertz systems; benefiting OAM related researches such as mode division multiplexing, vortex beam related plasmonic enhancement and spinning objective detection.

BackgroundThe 2020 Chinese guidelines for ultrasound malignancy risk stratification of thyroid nodules: the C-TIRADS (C-TIRADS for short) put forward a method for stratifying the malignancy risk of thyroid nodules, but there are few studies about its value in differentiating benign and malignant thyroid nodules.ObjectiveTo compare the value of ultrasound-based thyroid nodule malignancy risk stratification in differentiating malignant and benign thyroid nodule between C-TIRADS and 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: the American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer (ATA guidelines for short) .MethodsA total of 336 inpatients who underwent surgery and ultrasound examination in Bozhou People's Hospital from January 2019 to May 2021 were selected as participants. Four ultrasonologists with a title higher than attending physician were equally randomized into groups A and B for evaluating ultrasonic examination results according to ultrasound-based thyroid nodule malignancy risk stratification in C-TIRADS and ATA guidelines, respectively. The accuracies of ultrasound-based thyroid nodule malignancy stratification in the two guidelines in differentiating malignant and benign thyroid nodules were assessed using intraoperative or postoperative pathological findings (gold standard for diagnosis) , and were further analyzed using ROC analysis.ResultsAccording to intraoperative or postoperative pathological findings, the participants had 367 thyroid nodules in total, including 253 benign nodules and 114 malignant nodules. The nodules were classified as follows according to the TI-RADS in the C-TIRADS by ultrasonologists in group A: (1) 253 benign nodules: 2 were in TI-RADS 5 category, 23, 30, and 80 were in categories 4c, 4b, and 4a, respectively, 103 were in 3 category, and 15 were in 2 category; (2) 114 malignant nodules: 24 were in TI-RADS 5 category, 59 were in 4c category, 22 were in 4b category, 6 were in 4a category and 3 were in 3 category. And the classification of nodules according to the ATA guideline by ultrasonologists in group B was: (1) 253 benign nodules: 13, 53, 47, 118 were high, intermediate, low, and very low suspicion pattern for malignancy, respectively, and 22 were benign pattern; (2) 114 malignant nodules: 76, 24, 8, 6 were high, intermediate, low, and very low suspicion pattern for malignancy, respectively. ROC analysis showed that, AUCs of ultrasound-based thyroid nodule malignancy risk stratification in differentiating malignant and benign thyroid nodules between C-TIRADS and ATA guidelines were 0.890〔95%CI (0.815, 0.918) 〕and 0.780〔95%CI (0.750, 0.876) 〕, with significant difference (Z=13.62, P

Terahertz (THz) communication is an up‐and‐coming technology for the sixth‐generation wireless network. The realization of ultra‐high‐speed THz communication requires the combination of multi‐dimensional multiplexing schemes, including polarization division multiplexing (PDM), mode division multiplexing (MDM), and wavelength division multiplexing, to increase channel capacity. However, most existing devices for MDM in the THz regime are single‐purpose and incapable of multi‐dimensional modulation. Here, all‐dielectric metasurfaces are designed for 2D multiplexing/demultiplexing, which takes the lead in combining orbital angular momentum (OAM) MDM and PDM in the THz regime. The multi‐functional wavefront phase modulations and interleaved meta‐atom arrangements are used to realize polarization‐selective multichannel OAM mode (de)multiplexing, in which the linear‐polarized 4‐channel and circular‐polarized 6‐channel demultiplexing are experimentally demonstrated. Between different linear‐polarized channels, the measured maximum crosstalk is −16.88 dB, and the isolation of each channel can be greater than 10 dB in a range wider than 0.1 THz. This study paves the way for multi‐dimensional multiplexing in the THz regime, which may benefit extremely high‐capacity and integrated THz communication systems. The proposed design strategy is readily applied to multi‐functional metasurfaces for microwaves and far infrared light, facilitating the development of multiplexing technology and OAM‐related applications. [ABSTRACT FROM AUTHOR]

Background: Prostate cancer (PCa) is a leading cause of cancer-related death in men. Understanding the proteomic landscape associated with PCa risk can provide insights into its molecular mechanisms and pave the way for potential therapeutic interventions. Methods: A proteome-wide Mendelian randomization (MR) analysis was employed to determine associations between genetically predicted protein concentrations in plasma and PCa risk. From an initial list of 4,364 proteins, significant associations were identified and validated. Multiple sensitivity analyses were also conducted to enhance the robustness of our findings. Results: Of the 4,364 genetically predicted proteins, 308 exhibited preliminary associations with PCa risk. After rigorous statistical refinement, genetically predicted concentrations of 14 proteins showed positive associations with PCa risk, with odds ratios spanning from 1.55 (95% CI 1.28–1.87) for ATG4B to 2.67 (95% CI 1.94–3.67) for HCN1. In contrast, genetically predicted concentrations of ATG7, B2M, MSMB, and TMEM108 demonstrated inverse associations with PCa. The replication analysis further substantiated positive associations for MDH1 and LSM1, and a negative one for MSMB with PCa. A meta-analysis harmonizing primary and replication data mirrored these findings. Furthermore, the MVMR analysis pinpointed B2M and MSMB as having significant associations with PCa risk. Conclusion: The genetic evidence unveils a refined set of proteins associated with PCa risk. The findings underscore the potential of these proteins as molecular markers or therapeutic targets for PCa, calling for deeper mechanistic studies and exploration into their translational relevance. [ABSTRACT FROM AUTHOR]

Sandalwood essential oil, known for its rich content of phenolic and flavonoid compounds, holds great promise for applications in perfumery and medicine. However, traditional production methods have raised concerns regarding their environmental impact and sustainability. This study explored subcritical ethanol extraction as a green technique to address these concerns. Under optimized conditions (6.04 MPa, 109 °C, and 2.01 mL/min), maximum oil yield reached 4.04% with substantial total phenolic compounds (TPCs) of 4.11 mg GAE/100 g and total flavonoid compounds (TFCs) of 8.85 mg QE/100 g in the extracted sandalwood oil. Furthermore, the oil displayed notable antioxidant activity AA of 71.68%. The temperature was identified as a significant factor affecting oil yield, TPCs, TFCs, and AA. The fine-tuning of the extraction temperature enhanced the desired characteristics, improving bioactive compound yields and heightening antioxidant potential. This study uses a green extraction technique to contribute to sustainable sandalwood essential oil production. [ABSTRACT FROM AUTHOR]

Hyperbolic metasurfaces with unique dispersion properties can manipulate light–matter interactions according to the demands. However, due to their inherent physical properties, topological transitions (flat bands) exist only in the orthogonal directions, which greatly limit their application. Here, we unveil rich dispersion engineering and topological transitions in hyperbolic metasurfaces. Based on the effective medium theory, the rotation matrix is introduced into the dispersion relation to explain the distorted energy band diagrams, iso-frequency contours and higher-order multi-dipoles of the novel twisted metasurfaces, thereby forming multi-directional topological transitions and surface plasmon polariton propagation. Furthermore, we develop an integrated model to realize new dual-channel negative refraction and nondiffraction negative refraction. The phenomena observed in the experiments match well with the simulations, which proves that the designed metasurfaces make new types of negative refraction possible and will help to overcome the diffraction limit. The hyperbolic metasurfaces presented here exhibit exceptional capabilities for designing microscopes with a super lens at the molecular level, concealment of military aircraft, invisibility cloaks and other photonic devices with higher transmission efficiency.