Federated learning (FL) has revolutionized medical image analysis by enabling collaborative model training while maintaining patient data privacy. This paper explores the applications, challenges, and innovations of FL in medical imaging, highlighting its role in diagnostic improvements, data heterogeneity management, and integration with explainable AI (XAI). Notable advancements include open-source frameworks, privacy-preserving techniques, and strategies to address non-IID data challenges. Case studies from Shanghai demonstrate FL's potential in enhancing diagnostic accuracy through multi-institutional collaboration while safeguarding sensitive data. Despite these successes, challenges remain, including computational constraints, ethical considerations, and technical complexities. The paper emphasizes future research directions such as refining FL algorithms for heterogeneous data, improving privacy techniques, and enhancing model generalization. By addressing these challenges, FL can continue to transform medical imaging, fostering secure, efficient, and scalable AI applications in healthcare.
Ultrathin metasurfaces consisting of subwavelength anisotropic plasmonic resonators with spatially variant orientations are capable of generating local geometric phase profiles for circular polarizations (CP) and can be used for multiplexing of electromagnetic waves. As the geometric phase solely depends on the orientation of dipole antennas, the phase profiles cannot be changed dynamically with external environment once the structure is fabricated. Here, by incorporating geometric phase and resonance-induced dynamic phase in a monolayer of nano gold antennas, we show that phase profiles of different spin components can vary independently through modification of the external environment. Specifically, the intensities of the + 1 and -1 order diffracted waves vary asymmetrically with the refractive index of surrounding media, forming a dual-channel sensing system. Our dual-channel sensing method exhibits very high signal-to-noise ratio and stability for sensing of liquid, monomolecular layer and even nanoscale motion, which will have potential applications in various fields, including biosensing, precision manufacturing, monitoring of environment, and logic operations.
Abstract Metasurfaces based on geometric phase acquired from the conversion of the optical spin states provide a robust control over the wavefront of light, and have been widely employed for construction of various types of functional metasurface devices. However, this powerful approach cannot be readily transferred to the manipulation of acoustic waves because acoustic waves do not possess the spin degree of freedom. Here, we propose the concept of acoustic geometric-phase meta-array by leveraging the conversion of orbital angular momentum of acoustic waves, where well-defined geometric-phases can be attained through versatile topological charge conversion processes. This work extends the concept of geometric-phase metasurface from optics to acoustics, and provides a new route for acoustic wave control.
In this article we consider unitary operators on the Hilbert C*-module HA associated with a large class of C*-algebras. Let L(X) denote the algebra consisting of all bounded linear operators on a separable Hilbert space 7 and let K denote the algebra of all compact operators on R. Halmos and Kakutani proved that every unitary operator on R is a product of four symmetries (cf. [Ha], 143; [HaKa]). For the case when X is a compact Hausdorff space, Ringrose [R] recently considered the C*-algebra C(X, L(Q)), consisting of all norm-continuous maps from X to L(X), and proved that every unitary element of C(X, L(X)) can be written as a product of, at most, three exponentials; in other words, a norm-continuous map u(.) from X to the unitary group of L(X) forms a product of three norm-continuous maps written as exp(ihi) exp(ih2) exp(ih3), where hl, h2 and h3 are maps from X to the space of self-adjoint operators in L(X). Phillips and Ringrose [PhR] conjectured that every unitary of C(X, L(X)) can even be approximated in the norm by products of two exponentials. Using techniques in the theory of C*-algebras, but by a different approach, we generalized Ringrose's result to Hilbert C*-modules associated with all a-unital (in particular, all unital) C*-algebras (cf. [Z8]). We also proved in [Z8] similar results for the C*-algebra consisting of norm-continuous maps from X to a purely infinite simple C*-algebra. The purpose of this article is to settle the Phillips-Ringrose conjecture in the affirmative and to prove a generalized version of the Halmos-Kakutani theorem in [HaKa]. We consider the group of unitary operators on Hilbert C*-modules associated with the following two specific classes, which together comprise the majority of interesting C*-algebras:
Abstract: We investigated the pharmacokinetics and safety profiles of a newly developed combined ethinylestradiol (EE)/gestodene (GSD) transdermal contraceptive patch after a single-dose administration and compared with the market available tablet formulation in healthy adult subjects. An open-label, two-period comparative study was conducted in 12 healthy women volunteers. A single dose of the study combined EE/GE transdermal contraceptive patch and oral tablet (Milunet ® ) were administered. Blood samples at different time points after dose were collected, and concentrations were analyzed. A reliable, highly sensitive and accurate high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC/MS/MS) assay method was developed in this study to determine the plasma concentrations of EE and GSD. Compared to the tablet, the study patch had a significantly decreased maximum plasma concentration (C max ), extended time to reach the C max and half-life, as well as increased clearance and apparent volume of distribution. The half-lives of EE and GSD of the patch were 3.3 and 2.2 times, respectively, than the half-life of the tablet. The areas under the plasma concentration–time curve (AUCs) of EE and GSD of the patch were 8.0 and 16.2 times, respectively, than the AUC of the tablet. No severe adverse event was observed during the whole study, and the general safety was acceptable. In conclusion, compared to the oral tablet Milunet, the study contraceptive patch was well tolerated and showed potent drug exposure, significant extended half-life and stable drug concentrations. Keywords: pharmacokinetics, safety, ethinylestradiol/gestodene, transdermal contraceptive patch
Since 2000 years ago, metaphor is regarded as a rhetorical device to add ornament and color to the language.Until the recent twenty years, metaphor is seen as a cognitive device in people's processes of perceiving the world and understanding new things.At the meantime, advertisement becomes an indispensable part in the modern society, while advertising language is the soul of advertisement.In order to achieve the goals of persuasion and consumption, metaphor is widely used in advertising languages by admen.It is so widely spread that arouses great interests of scholars all over the world.They have noticed that an ad with metaphor is more vivid, attractive, informative and persuasive than the one without.The vividness and attractiveness of metaphor can be explained by its rhetorical outlook, but this rhetorical point of view cannot touch the informative and persuasive functions of metaphor.Then the scholars turned their eyes to the cognitive theory of metaphor.
Tetrapod CdSe/CdS quantum dots (QDs) have attracted extensive research interest in light-emitting applications due to their anisotropic optical properties and large absorption cross-section. Traditional synthesis methods for tetrapod CdSe/CdS QDs usually employ fatty phosphonic acid ligands to induce the growth of wurtzite CdS arms on cubic CdSe QDs at high temperatures (350-380 °C). Here, a low temperature (120 °C) route was developed for the synthesis of tetrapod CdSe/CdS QDs using mixed amine ligands instead of phosphonic acid ligands. A study of the growth mechanism reveals that the amine ligands induce the orientation growth of cubic CdS arms on wurtzite CdSe QDs through a pyramid-shaped intermediate structure. The low reaction temperature facilitates the growth control of the tetrapod CdSe/CdS QDs through a microfluidic reactor. This study substantially simplifies the synthetic chemistry for the anisotropic growth of CdS on CdSe QDs, paving the way for green and economic production of tetrapod CdSe/CdS QDs towards efficient light-emitting applications.
Abstract Optical spin-Hall effect (OSHE) is a spin-dependent transportation phenomenon of light as an analogy to its counterpart in condensed matter physics. Although being predicted and observed for decades, this effect has recently attracted enormous interests due to the development of metamaterials and metasurfaces, which can provide us tailor-made control of the light-matter interaction and spin-orbit interaction. In parallel to the developments of OSHE, metasurface gives us opportunities to manipulate OSHE in achieving a stronger response, a higher efficiency, a higher resolution, or more degrees of freedom in controlling the wave front. Here, we give an overview of the OSHE based on metasurface-enabled geometric phases in different kinds of configurational spaces and their applications on spin-dependent beam steering, focusing, holograms, structured light generation, and detection. These developments mark the beginning of a new era of spin-enabled optics for future optical components.
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