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Efficient, broadband illumination and collection through a nanometre-sized hotspot carried by a scanning probe will endow light–matter interaction research with nanoscale spatial information. However, near-field scanning optical microscopy probes, particularly the high-resolution ones, demand cumbersome optics but can only concentrate less than 10−3 of the incident light, which has limited its applications. Here, we report a two-step sequential broadband nanofocusing technique with an external nanofocusing efficiency of ~50% over nearly all the visible range on a fibre-coupled nanowire scanning probe, which is capable of both light delivery and spectrum collection with nanoscale spatial resolution. By integrating this with a basic portable scanning tunnelling microscope, we have demonstrated lens-free tip-enhanced Raman spectroscopy and achieved 1 nm spatial resolution. The high performance and vast versatility offered by this fibre-based nanofocusing technique allow for the easy incorporation of nano-optical microscopy into various existing measurement platforms.A two-step sequential broadband nanofocusing technique offers an external efficiency of ~50% over nearly all the visible range on a fibre-coupled plasmonic nanowire probe. Its integration with a scanning tunnelling microscope realizes lens-free tip-enhanced Raman spectroscopy with 1 nm spatial resolution.

Optical transmission and scattering spectroscopic microscopy at the visible and adjacent wavelengths denote one of the most informative and inclusive characterization methods in material research. Unfortunately, restricted by the diffraction limit of light, it cannot resolve the nanoscale variation in light absorption and scattering, diagnostics of the local inhomogeneity in material structure and properties. Moreover, a large quantity of nanomaterials has anisotropic optical properties that are appealing yet hard to characterize through conventional optical methods. There is an increasing demand to extend the optical hyperspectral imaging into the nanometer length scale. In this work, we report a super-resolution hyperspectral imaging technique that uses a nanoscale white light source generated by superfocusing the light from a tungsten-halogen lamp to simultaneously obtain optical transmission and scattering spectroscopic images. A 6-nm spatial resolution in the visible to near-infrared wavelength regime (415–980 nm) is demonstrated on an individual single-walled carbon nanotube (SW-CNT). Both the longitudinal and transverse optical electronic transitions are measured, and the SW-CNT chiral indices can be identified. The band structure modulation in a SW-CNT through strain engineering is mapped. The authors present a super-resolution hyperspectral imaging technique using a nanoscale white light source generated by superfocusing light from a tungsten-halogen lamp. They achieve 6 nm resolution, measuring longitudinal and transverse optical electronic transitions in single-walled carbon nanotubes.

A fascinating photonic platform with a small device scale, fast operating speed, as well as low energy consumption is two-dimensional (2D) materials, thanks to their in-plane crystalline structures and out-of-plane quantum confinement. The key to further advancement in this research field is the ability to modify the optical properties of the 2D materials. The modifications typically come from the materials themselves, for example, altering their chemical compositions. This article reviews a comparably less explored but promising means, through engineering the photonic surroundings. Rather than modifying materials themselves, this means manipulates the dielectric and metallic environments, both uniform and nanostructured, that directly interact with the materials. For 2D materials that are only one or a few atoms thick, the interaction with the environment can be remarkably efficient. This review summarizes the three degrees of freedom of this interaction: weak coupling, strong coupling, and multifunctionality. In addition, it reviews a relatively timing concept of engineering that directly applied to the 2D materials by patterning. Benefiting from the burgeoning development of nanophotonics, the engineering of photonic environments provides a versatile and creative methodology of reshaping light–matter interaction in 2D materials.

A double-edged sword in two-dimensional material science and technology is optically forbidden dark exciton. On the one hand, it is fascinating for condensed matter physics, quantum information processing, and optoelectronics due to its long lifetime. On the other hand, it is notorious for being optically inaccessible from both excitation and detection standpoints. Here, we provide an efficient and low-loss solution to the dilemma by reintroducing photonics bound states in the continuum (BICs) to manipulate dark excitons in the momentum space. In a monolayer tungsten diselenide under normal incidence, we demonstrated a giant enhancement (~1400) for dark excitons enabled by transverse magnetic BICs with intrinsic out-of-plane electric fields. By further employing widely tunable Friedrich-Wintgen BICs, we demonstrated highly directional emission from the dark excitons with a divergence angle of merely 7°. We found that the directional emission is coherent at room temperature, unambiguously shown in polarization analyses and interference measurements. Therefore, the BICs reintroduced as a momentum-space photonic environment could be an intriguing platform to reshape and redefine light-matter interactions in nearby quantum materials, such as low-dimensional materials, otherwise challenging or even impossible to achieve. Here, the authors integrate a photonic crystal, supporting photonic bound states in the continuum (BICs), with monolayer WSe 2 , and leverage the high energy confinement of the BIC modes to demonstrate coherent directional dark exciton emission.

Silver nanowires (AgNWs) hold great promise for applications in wearable electronics, flexible solar cells, chemical and biological sensors, photonic/plasmonic circuits, and scanning probe microscopy (SPM) due to their unique plasmonic, mechanical, and electronic properties. However, the lifetime, reliability, and operating conditions of AgNW-based devices are significantly restricted by their poor chemical stability, limiting their commercial potentials. Therefore, it is crucial to create a reliable oxidation barrier on AgNWs that provides long-term chemical stability to various optical, electrical, and mechanical devices while maintaining their high performance. Here we report a room-temperature solution-phase approach to grow an ultra-thin, epitaxial gold coating on AgNWs to effectively shield the Ag surface from environmental oxidation. The Ag@Au core-shell nanowires (Ag@Au NWs) remain stable in air for over six months, under elevated temperature and humidity (80 °C and 100% humidity) for twelve weeks, in physiological buffer solutions for three weeks, and can survive overnight treatment of an oxidative solution (2% H 2 O 2 ). The Ag@Au core-shell NWs demonstrated comparable performance as pristine AgNWs in various electronic, optical, and mechanical devices, such as transparent mesh electrodes, surface-enhanced Raman spectroscopy (SERS) substrates, plasmonic waveguides, plasmonic nanofocusing probes, and high-aspect-ratio, high-resolution atomic force microscopy (AFM) probes. These Au@Ag core-shell NWs offer a universal solution towards chemically-stable AgNW-based devices without compromising material property or device performance.

Background Chronic musculoskeletal pain (CMP) is a complex condition that is mainly treated with analgesic drugs. However, antidepressant intervention is also an important factor in the treatment of CMP. Duloxetine is an effective treatment option for patients with CMP as its antidepressant effect. The purpose of this article is to evaluate the efficacy and safety of duloxetine in treating CMP. Databases and data treatment We searched PubMed, Web of Science, Embase, Cochrane Library from inception to May, 2022. Randomized controlled trials (RCTs) evaluating the efficacy and safety of duloxetine versus placebo in patients with CMP were included. We identified 13 articles and studied a population of 4201 participants in 4 countries. Results This meta-analysis showed that the duloxetine has statistically significant compared with the placebo control, benefits on 24-hour average pain, living quality, physical function, and global impressions and there was no difference in the incidence of serious adverse event. In general, duloxetine can improve mood and pain level at the same time. Conclusions This review shows a significant contribution of duloxetine to CMP symptom relief. This meta-analysis improved that duloxetine can significantly reduce the pain level of patients, improve depressive symptoms and global impression, and has no obvious serious adverse reactions. However, additional studies are required to confirm the relationship between psychological diseases and chronic pain and explore their internal links.

Anisotropic optical crystals can exhibit a hyperbolic response within the Reststrahlen band (RB) and support directional polaritonic propagations when interacting with light. Most of the reported low-symmetry optical crystals showcase the evolution from hyperbolic to elliptic dispersion topologies, largely owing to their adjacent RBs being either overlapped or separated. Here, we report an exceptional Reststrahlen point (ERP) in rare-earth oxyorthosilicate Y 2 SiO 5 , at which two neighboring RBs almost kiss each other. Consequently, we observe the direct hyperbolic-to-hyperbolic topological transition: the hyperbolic branches close and reopen along with the rotating transverse axis (TA). At such ERP, the TA merges to the direction orthogonal to its proximate phonon mode, mainly due to the interplay between these two non-orthogonal phonon modes. We also find that even with the existence of only one single RB, the TA can rotate in-plane. Our findings are prevalent in isostructural rare-earth oxyorthosilicates, such as Lu 2 SiO 5 . The universally underlying physics of ERP and its corresponding special class of rare-earth oxyorthosilicates may offer playgrounds for continuously tuning phonon polariton propagation direction, and broadband controlling light dispersion of polaritonic nanodevices. The authors reveal hyperbolic-to-hyperbolic transitions where two nearby Reststrahlen bands just touch each other. Such phenomena are prevalent in isostructural rare-earth oxyorthosilicates and unfolds vast opportunities for broadband on-chip light control.

Design of micro/nanotextured consumer product surfaces presents the opportunity to enrich tactile experiences and enhance the capabilities of haptic devices, enabling rich human-object interactions through the passive or active control of finger friction. The absence of a comprehensive model that can holistically represent the underlying physics at finger-material interface, however, inhibits reliable prediction of finger friction. Here, we develop a model for micro/nanostructured touch interfaces, accounting for contact mechanics, capillaries, electrostatic fields, and their mutual interactions. We experimentally validate this model and apply it to predicting the friction and adhesion of microparticle-coated plastic films for food packaging, and designing surface structures for electroadhesive surfaces to achieve both stronger effects and lower variability — essential features for high-volume consumer electronics. Our model has wide applicability in predictive design of micro/nanostructured surfaces with diverse haptic functionalities. Reliable models for predicting friction between a human finger and a surface is important for haptic devices and human-object interactions. Here, a model is developed for micro/nanostructured touch interfaces and experimentally validated.

In this study, to enhance deep tissue penetration by near-infrared (NIR) light, a novel superparamagnetic iron oxide-enclosed hollow gold nanoshell (SPIO-HGNS) structure with tunable size and surface plasmon resonance (SPR) in the NIR range was designed and synthesized through a two-step template-enabled galvanic replacement reaction. Here, Ag-coated SPIO (SPIO-Ag) was prepared as a template with tunable outer diameters by way of adjusting the Ag content. SPIO-HGNS with variable hollow gold inner diameters can then be synthesized based on the determined outer diameter of the SPIO-Ag template through a galvanic replacement reaction between HAuCl3 and Ag coating on the SPIO surface. With incrementing amounts of Ag, three SPIO-HGNS structures were synthesized with comparable shell thicknesses around 6.7 nm and an average inner diameter of 38.7, 39.4, and 40.7 nm, respectively, evidenced by TEM and ICP results. The structure of SPIO-HGNS was confirmed by identifying Au111 lattice and the elemental mapping of Fe and Au using energy-dispersive X-ray spectroscopy. The ultraviolet–visible-NIR absorption spectra showed red-shifted SPR peaks (820, 855, and 945 nm) with the increasing inner diameters of SPIO-HGNS, which was also supported by an absorption cross-section simulation. The photothermal results showed that the three SPIO-HGNS structures, when exposed to ~ 30 s of 400 mW laser irradiation, exhibited photothermal temperature rises of 5.9, 4.6, and 2.9 ℃, respectively. This study explored the tuning of SPR properties in NIR-responsive magneto-plasmonic nanoparticles through a facile preparation procedure, paving the way for potential applications in photothermal therapies.Graphical abstractThe NIR-responsive magneto-plasmonic SPIO-HGNS nanostructures were developed with tunable SPR properties and strong photothermal conversion capacities.

Objective. The present study examined the effects of Tai Chi exercise on the executive functions (EFs) and physical fitness of middle-aged adults with depression. Methods. A total of 39 middle-aged adults with depression (Mage = 50.59, SD = 7.38) were randomly assigned to the Tai Chi group (n = 20) or the waiting-list control group (n = 19). The Tai Chi group engaged in two 90 min sessions of Tai Chi exercise per week for 12 weeks; the waiting-list control group was asked to maintain their usual daily routines for 12 weeks. Depression symptoms, EFs (i.e., inhibitory control, planning, working memory, and cognitive flexibility), and physical fitness (i.e., cardiovascular fitness, muscular strength, muscular endurance, power, and flexibility) were evaluated at the baseline (pretest), 6-week (mid-test), and 12-week (post-test) marks. Results. Both groups showed decreased depression symptoms over time. Compared with the control group, the Tai Chi group showed decreased reaction times for incongruent conditions in the Stroop test from pretest to mid- and post-test, and shorter reaction time for incongruent conditions in the Stroop test than the control group at post-test; the Tai Chi group performed significantly better than the control group in overall total move score of Tower of London (TOL). The Tai Chi group also showed increased total correct scores of TOL from pretest to mid- and post-test, and greater total correct scores of TOL than the control group at post-test. Additionally, results indicated that Tai Chi exercise comprehensively improved physical fitness from pretest to mid- and post-test. Greater performance in terms of cardiovascular fitness, muscular strength, and power was also found in the Tai Chi group at post-test than in the control group. Conclusions. These findings suggest that the 12-week Tai Chi exercise improved inhibitory control, planning and working memory aspects of executive functions, and physical fitness in middle-aged adults with depression.