Theoretical prediction and experimental measurements of light attenuation in chemically pure and optically transparent solvents have attracted continuous attention, due in part to their curious ...nature, and in part to the increasing requirements of solvent-related applications. Yet hitherto, a majority of accurate spectrophotometric measurements of transparent solvents upon visible light radiation often end up using long-path-length cells, usually over dozens of cm, rendering the measure costly and complex; meanwhile, the guidance for choosing the Einstein-Smoluchowski equation or its variants as the best formula to predict the light scattering in solvents has remained elusive. Here we demonstrate a simple, versatile and cost-effective spectrophotometric method, enabling a sensitivity of 10
−4
dB cm
−1
over a 0.5 cm differential path length based on using standard double-beam spectrophotometer. We prove that this method reduces the path length by a factor of 100 while still making its closest approach to the record-low measurement of solvent extinction. We also validate that all the present equations used for predicting the light scattering in the solvent possess similar capacities, suggesting that the criterion for the choice of the appropriate formula simply depends on the equation's practicability. Following the elucidation of the wavelength range where the light scattering dominates the extinction, we further identify differences between scattering coefficients
via
the theoretical predictions and experimental measures, exposing the need for an improved theory to account for the solvent scattering phenomenon.
We develop a highly accessible and accurate spectrophotometric method, and identify shortcomings of the Einstein-Smoluchowski equations in solvent scattering predictions.
Glass containing optically active nanoparticles have been manufactured for centuries. However, only in the early 1900s, the invention of ultramicroscope and development of Mie theory paved the way to ...discovering the occurrence of nanoparticles in glass and their special role in imparting unique optical properties to glass. This groundbreaking insight inspired scientists to extensively research such nanoparticles‐in‐glass hybrid optical materials, which led to a series of fundamental breakthroughs (e.g., invention of glass ceramics, discovery of quantum dots) and commercial successes (e.g., photosensitive glass, photochromic glass, dichromic polarizer). Over the past decades, a new wave of research in this area has been initiated by opportunities of incorporating a large variety of synthetic nanoparticles in glass, which promises the development of advanced functional devices for lighting, display, smart window, data storage, and sensing applications. Recent development of various approaches of fabricating nanoparticles‐in‐glass hybrid optical materials and postmodifying nanoparticles that are embedded in glass is reviewed. The state‐of‐the‐art techniques relevant to controlling the dispersion, distribution, orientation, and nanostructure of nanoparticles in glass, as well as manipulating the macroscopic performance of the hybrid materials are discussed. Examples of applications with promising pathway to commercially viable devices based on hybrid optical materials are outlined.
The integration of optically active nanoparticles within a glass matrix is reviewed to provide a comprehensive discussion on the various techniques that are widely used to embed and postmodify nanoparticles in glass, and state‐of‐the‐art applications of their prototype devices that have been developed.
Calcium ions (Ca2+) take part in intra‐ and inter‐cellular signaling to mediate cellular functions. Sensing this ubiquitous messenger is instrumental in disentangling the specific functions of ...cellular sub‐compartments and/or intercellular communications. In this review, the authors first describe intra‐ and inter‐cellular Ca2+ signaling in relation to insulin secretion from the pancreatic islets, and then outline the development of diverse sensors, for example, chemically synthesized indicators, genetically encoded proteins, and ion‐selective microelectrodes, for intra‐ and extra‐cellular sensing of Ca2+. Particular emphasis is placed on emerging approaches in this field, such as low‐affinity Ca2+ indicators and unique Ca2+‐responsive composite materials. The authors conclude by remarking on the challenges and opportunities for further developments in this field, which may facilitate a more comprehensive understanding of Ca2+ signaling within and outside the islets, and its relevance in health and disease.
This review describes the development and current status of Ca2+ sensors in tracing intra‐ and extra‐cellular Ca2+, with a focus on the relevance of Ca2+ signaling to insulin secretion in the islet of Langerhans. Insights into Ca+ sensors have a high potential to facilitate their advancement toward improved understanding of the molecular mechanisms underpinning cellular functions.
Abstract
Calcium ions (Ca
2+
) take part in intra‐ and inter‐cellular signaling to mediate cellular functions. Sensing this ubiquitous messenger is instrumental in disentangling the specific ...functions of cellular sub‐compartments and/or intercellular communications. In this review, the authors first describe intra‐ and inter‐cellular Ca
2+
signaling in relation to insulin secretion from the pancreatic islets, and then outline the development of diverse sensors, for example, chemically synthesized indicators, genetically encoded proteins, and ion‐selective microelectrodes, for intra‐ and extra‐cellular sensing of Ca
2+
. Particular emphasis is placed on emerging approaches in this field, such as low‐affinity Ca
2+
indicators and unique Ca
2+
‐responsive composite materials. The authors conclude by remarking on the challenges and opportunities for further developments in this field, which may facilitate a more comprehensive understanding of Ca
2+
signaling within and outside the islets, and its relevance in health and disease.
Hybrid-material optical fibers enhance the capabilities of fiber-optics technologies, extending current functionalities to several emerging application areas. Such platforms rely on the integration ...of novel materials into the fiber core or cladding, thereby supporting hybrid modes with new characteristics. Here we present experiments that reveal hybrid mode interactions within a doped-core silica fiber containing a central high-index nanofluidic channel. Compared with a standard liquid-filled capillary, calculations predict modes with unique properties emerging as a result of the doped core/cladding interface, possessing a high power fraction inside and outside the nanofluidic channel. Our experiments directly reveal the beating pattern in the fluorescent liquid resulting from the excitation of the first two linearly polarized hybrid modes in this system, being in excellent agreement with theoretical predictions. The efficient excitation and beat of such modes in such an off-resonance situation distinguishes our device from regular directional mode couplers and can benefit applications that demand strong coupling between fundamental- and higher-order- modes, e.g. intermodal third-harmonic generation, bidirectional coupling, and nanofluidic sensing.
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