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Perfect vortex beams are the orbital angular momentum (OAM)-carrying beams with fixed annular intensities, which provide a better source of OAM than traditional Laguerre-Gaussian beams. However, ordinary schemes to obtain the perfect vortex beams are usually bulky and unstable. We demonstrate here a novel generation scheme by designing planar Pancharatnam-Berry (PB) phase elements to replace all the elements required. Different from the conventional approaches based on reflective or refractive elements, PB phase elements can dramatically reduce the occupying volume of system. Moreover, the PB phase element scheme is easily developed to produce the perfect vector beams. Therefore, our scheme may provide prominent vortex and vector sources for integrated optical communication and micromanipulation systems.

The photonic spin Hall effect (SHE) originates from the interplay between the photon-spin (polarization) and the trajectory (extrinsic orbital angular momentum) of light, i.e. the spin-orbit interaction. Metasurfaces, metamaterials with a reduced dimensionality, exhibit exceptional abilities for controlling the spin-orbit interaction and thereby manipulating the photonic SHE. Spin-redirection phase and Pancharatnam-Berry phase are the manifestations of spin-orbit interaction. The former is related to the evolution of the propagation direction and the latter to the manipulation with polarization state. Two distinct forms of splitting based on these two types of geometric phases can be induced by the photonic SHE in metasurfaces: the spin-dependent splitting in position space and in momentum space. The introduction of Pacharatnam-Berry phases, through space-variant polarization manipulations with metasurfaces, enables new approaches for fabricating the spin-Hall devices. Here, we present a short review of photonic SHE in metasurfaces and outline the opportunities in spin photonics.

[3] However, PFA ependymoma mostly occurs in infants and young children, to whom ionizing radiation may pose great risks. [...]there is still an urgent need in the treatment of PFA ependymoma patients who could not or are reluctant to receive radiotherapy. [...]the half-maximal inhibitory concentration (IC50) of cisplatin was reduced from 451.00 nmol/L to 62.52 nmol/L in C67-KO cells with CXorf67 re-expression restored when niraparib was used [Figure 1A]. See PDF] In summary, the treatment of PARP inhibitors combined with chemotherapy undoubtedly opens a new avenue for PFA ependymoma patients, especially those who cannot or are reluctant to receive radiotherapy. [...]it offers an option as a salvage regimen for recurrent PFA patients with CXorf67 high expression, for which no standard medical treatment exists, although further clinical researches are required.

Negative refraction, an unnatural optical phenomenon in which the incident and the refracted waves reside on the same side of the surface normal, has been demonstrated with the invention of negative index media based on artificially engineered photonic structures called metamaterials. It has received wide attention due to its potential applications in imaging, nonlinear optics, and electromagnetic cloaking. However, it is highly challenging to realize negative refraction operating at all angles and with the perfect transmission. In this work, leveraging the recent development in topological photonics, we propose to realize reflectionless negative refraction for all incident angles with a topological metamaterial. The proposed metamaterial possesses two Weyl points of opposite topological charges. By interfacing the metamaterial with a perfect electric conductor (PEC) or a perfect magnetic conductor (PMC), the Fermi arc connecting the two Weyl points can take the form of a half-circle possessing a positive or a negative refractive index. Importantly, due to the topological protection, there is no reflection at the interface between the PEC and PMC covered areas, leading to the observation of all-angle negative refraction without reflection at the boundary. Our work provides a new platform for manipulating the propagation of surface waves, which may find applications in the construction of integrated photonic devices.A robust negative index flat lens which collects all energy launched from the source is constructed with the ideal photonic Weyl metamaterials.

To study and quantify the impact of water storage on lake slope stability after the closure of an open-pit mine, we targeted slope control measures by large-scale parallel computing methods and strength reduction theory. This was based on a three-dimensional refined numerical model to simulate the evolution of slope stability under different water storage levels and backfilling management conditions, and to quantitatively assess the risk of slope instability through the spatial distribution of stability coefficients. This study shows that during the impoundment process, the slope stability has a nonlinear decreasing trend due to the decrease in effective stress caused by the increase in pore water pressure. When the water storage was at 0 m, the instability range is the largest, and the surface range is nearly 200 m from the edge of the pit; when the water level continued to rise to 50 m, the hydrostatic pressure of the pit lake water on the slope support effect began to appear, and the stability was improved, but there is still a wide range of unstable areas at the bottom. In view of the unstable area of the steep slope with soft rock in the north slope during the process of water storage, the management scheme of backfilling the whole bottom to −150 m was proposed, and the slope protection and pressure footing were formed by discharging the soil to −40 m in steps to improve the anti-slip ability of the slope.

In this study, we synthesized a novel fluorescein isothiocyanate (FITC)-labeled prostate-specific membrane antigen (PSMA) ligand (PSMA-FITC) via the Fmoc solid-phase synthesis method, and the application value of PSMA-FITC in targeted fluorescence imaging of PSMA-positive prostate cancer was evaluated. The PSMA ligand developed based on the Glu-urea-Lys structure was linked to FITC by aminocaproic acid (Ahx) to obtain PSMA-FITC. The new probe was evaluated in vitro and in vivo. Fluorescence microscopy examination of PSMA-FITC in PSMA(+) LNCaP cells, PSMA(−) PC3 cells, and blocked LNCaP cells showed that the binding of PSMA-FITC with PSMA was target-specific. For in vivo optical imaging, PSMA-FITC exhibited rapid 22Rv1 tumor targeting within 30 min of injection, and the highest tumor-background ratio (TBR) was observed 60 min after injection. The TBR was 3.45 ± 0.31 in the nonblocking group and 0.44 ± 0.13 in the blocking group, which was consistent with the in vitro results. PSMA-FITC is a promising probe and has important reference value for the development of PSMA fluorescent probes. In the future, it can be applied to obtain accurate tumor images for radical prostatectomy.

The Pancharatnam-Berry (PB) phase principle has been extensively utilized in the design of polarization-dependent, ultrathin, phase-gradient metasurfaces, where the PB phase shift is determined by twice the change in orientation angle of individual building blocks. Here, we reveal a topological transition in the phase-orientation dependence within a nonlocal bilayer metasurface, where a fourfold dependence emerges as the building blocks are tightly arranged. Additionally, we demonstrate that the Moiré pattern inherent to the bilayer metasurface provides a tunable mechanism for driving this topological transition, enabling the modulation of both deflection angle and topological charge of the transmitted field. Our findings not only offer a refined understanding of the PB phase principle in linear optical systems but also introduce twist angle as a novel degree of freedom for designing tunable PB phase devices.

Propagation properties of electromagnetic waves in an optical medium are mainly determined by the contour of equal-frequency states in k-space. In photonic Weyl media, the topological surface waves lead to a unique open arc of the equal-frequency contour, called the Fermi arc. However, for most realistic Weyl systems, the shape of Fermi arcs is fixed due to the constant impedance of the surrounding medium, making it difficult to manipulate the surface wave. Here we demonstrate that by adjusting the thickness of the air layer sandwiched between two photonic Weyl media, the shape of the Fermi arc can be continuously changed from convex to concave. Moreover, we show that the concave Fermi-arc waves can be used to achieve topologically protected electromagnetic pulling forces over a broad range of angles in the air layer. Our finding offers a generally applicable strategy to shape the Fermi arc in photonic Weyl media.The continuous evolution of the shape of the surface Fermi arc induces an electromagnetic pulling force that operates over a broad range of angles, effectively attracting a variety of small particles.

Developing efficient metal‐nitrogen‐carbon (M‐N‐C) single‐atom catalysts for oxygen reduction reaction (ORR) is significant for the widespread implementation of Zn‐air batteries, while the synergic design of the matrix microstructure and coordination environment of metal centers remains challenges. Herein, a novel salt effect‐induced strategy is proposed to engineer N and P coordinated atomically dispersed Fe atoms with extra‐axial Cl on interlinked porous carbon nanosheets, achieving a superior single‐atom Fe catalyst (denoted as Fe‐NP‐Cl‐C) for ORR and Zn‐air batteries. The hierarchical porous nanosheet architecture can provide rapid mass/electron transfer channels and facilitate the exposure of active sites. Experiments and density functional theory (DFT) calculations reveal the distinctive Fe‐N2P2‐Cl active sites afford significantly reduced energy barriers and promoted reaction kinetics for ORR. Consequently, the Fe‐NP‐Cl‐C catalyst exhibits distinguished ORR performance with a half‐wave potential (E1/2) of 0.92 V and excellent stability. Remarkably, the assembled Zn‐air battery based on Fe‐NP‐Cl‐C delivers an extremely high peak power density of 260 mW cm−2 and a large specific capacity of 812 mA h g−1, outperforming the commercial Pt/C and most reported congeneric catalysts. This study offers a new perspective on structural optimization and coordination engineering of single‐atom catalysts for efficient oxygen electrocatalysis and energy conversion devices. A novel single‐atom electrocatalyst with superior Fe‐N2P2‐Cl active sites is successfully synthesized through a salt effect‐induced strategy. The salt effect facilitates the formation of Fe‐N2P2‐Cl configuration, achieving significantly reduced energy barriers and promoting ORR kinetics. The induced interlinked nanosheet microstructure with hierarchical pores promotes the exposure of Fe‐N2P2‐Cl and provides rapid mass/electron transfer channels, guaranteeing the outstanding electrocatalytic performance of Zn‐air battery devices.

Starch is a natural polymer. It is also an important food nutrient. Studies related to starch content testing can provide basic data for starch intake assessments and correlation studies. Meanwhile, data on the starch content in food are important for guiding the population to have a reasonable diet. Starch content directly affects the nutritional value, consumption quality, and processing quality of food. This paper summarized the common starch content detection techniques in food in the past five years, such as titration, spectrophotometry, near-infrared spectroscopy, and other methods. The principles, advantages, and disadvantages of these starch content detection techniques were described and discussed. Their problems in real sample detection (e.g., time-consuming, cumbersome operation, over-reliance on modeling algorithms, etc.) were analyzed. Challenges and future trends are also presented with the expectation of providing useful references for future research and practical applications. This paper provides a direction and research basis for the development of starch content detection techniques for food. It also provides value to related work in starch research.