Salidroside promotes the repair of spinal cord injury by inhibiting astrocyte polarization, promoting neural stem cell proliferation and neuronal differentiation.

Spinal cord injury (SCI) remains a formidable challenge, lacking effective treatments. Following SCI, neural stem cells (NSCs) migrate to SCI sites, offering a potential avenue for nerve regeneration, but the effectiveness of this intrinsic repair mechanism remains suboptimal. Salidroside has demonstrated pro-repair attributes in various pathological conditions, including arthritis and cerebral ischemia, and the ability to curtail early-stage inflammation following SCI. However, the specific role of salidroside in the late-stage repair processes of SCI remains less defined. In this investigation, we observed that continuous salidroside treatment in SCI mice improved motor function recovery. Immunofluorescence-staining corroborated salidroside's capacity to stimulate nerve regeneration and remyelination, suppress glial scar hyperplasia, reduce the activation of neurotoxic A1 astrocytes, and facilitate NSCs migration towards the injured region. Mechanistically, in vitro experiments elucidated salidroside's significant role in restraining astrocyte proliferation and A1 polarization. It was further established that A1 astrocytes hinder NSCs proliferation while inducing their differentiation into astrocytes. Salidroside effectively ameliorated this inhibition of NSCs proliferation through diminishing c-Jun N-terminal kinase (JNK) pathway phosphorylation and restored their differentiation into neurons by suppressing the signal transducer and activator of transcription 3 (STAT3) pathway. In summary, our findings suggest that salidroside holds promise as a therapeutic agent for traumatic SCI treatment.

Upgrading anode graphite from retired lithium ion batteries via solid-phase exfoliation by mechanochemical strategy.

Vast quantities of anode graphite from waste lithium ion batteries (LIBs), as a type of underrated urban mine, has enormous potential to be exploited for resource recovery. Herein, we propose a benign process integrating low-temperature pyrolysis and mechanochemical techniques to upcycle spent graphite (SG) from end-of-life LIBs. Pyrolysis at 500 °C leads to about 82.2 % PVDF dissociation in thermal treated graphite (TG). Solid-phase exfoliation via ball milling assisted by urea successfully produces abundant graphite flakes and a small amount of monolayer graphene nanosheet at the edge of mechanochemically processed graphite (MG). Subsequent rinsing removes the residual LiF salts. High purity and unique edge structural features of the as-prepared MG offer more active sites and storage reservoir for intercalation and de-intercalation of lithium ions, resulting in enhanced lithium-ion diffusion kinetics, excellent reversible specific capacity and desirable rate capability. Inspiringly, MG exhibits a remarkably enhanced initial specific charge capacity of 521.3 mAh g-1 during the first charge-discharge, and only declines from 569.9 mAh g-1 to 538 mAh g-1 with slight attenuation after 50 consecutive cycles at 0.1 A/g, indicating satisfactory cycle stability. Additionally, the purification and reconstruction mechanism for MG have been illustrated in detail. This study offers a green strategy to reconstruct and upgrade anode graphite from LIBs, which can realize sustainable waste management.

Simplified Chinese version of the core outcome measures index (COMI) for patients with neck pain: cross-cultural adaptation and validation.

PURPOSE: The aim of this study was to translate and cross-culturally adapt the Core Outcome Measures Index for (COMI) into a Simplified Chinese version (COMI-SC) and to evaluate the reliability and validity of COMI-SC in patients with neck pain. METHODS: The COMI-neck was translated into Chinese according to established methods. The COMI-neck questionnaire was then completed by 122 patients with a hospital diagnosis of neck pain. Reliability was assessed by calculating Cronbach's alpha and intraclass correlation coefficient (ICC). Construct validity was assessed by correlating the COMI-neck with the Neck Pain and Disability Scale (NPDS), the Neck Disability Index (NDI), the VAS and the Short Form (36) Health Survey (SF-36). Using confirmatory factor analysis to validate the structural, convergent and discriminant validity of the questionnaire. RESULTS: The COMI-neck total scores were well distributed, with no floor or ceiling effects. Internal consistency was excellent (Cronbach's alpha = 0.861). Moderate to substantial correlations were found between COMI-neck and NPDS (r = 0.420/0.416/0.437, P < 0.001), NDI (r = 0.890, P < 0.001), VAS (r = 0.845, P < 0.001), as well as physical function (r = - 0.989, P < 0.001), physical role (r = - 0.597, P < 0.001), bodily pain (r = - 0. 639, P < 0.001), general health (r = - 0.563, P < 0.001), vitality (r = - 0.702, P < 0.001), social functioning (r = - 0.764, P < 0.001), role emotional (r = - 0.675, P < 0.001) and mental health (r = - 0.507, P < 0.001) subscales of the SF-36. An exploratory factor analysis revealed that the 3-factor loading explained 71.558% of the total variance [Kaiser-Mayer-Olkin (KMO) = 0.780, C2 = 502.82, P < 0.001]. CMIN/DF = 1.813, Tucker-Lewis index (TLI) = 0.966 (> 0.9), Comparative Fit Index (CFI) = 0.982 (> 0.9), Normed Fit Index (NFI) = 0.961 (> 0.9), RMSEA = 0.082 (< 0.5) indicating that the model fits well. CONCLUSION: COMI-neck was shown to have acceptable reliability and validity in patients with non-specific chronic neck pain and could be recommended for patients in mainland China. LEVEL OF EVIDENCE: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Market Segmentation and Green Development Performance: Evidence from Chinese Cities.

This study is based on 2006-2019 panel data from 282 Chinese cities. Market segmentation and green development performance are empirically investigated to examine their non-linear relationship using static panel, dynamic panel, and dynamic spatial panel models. The results reveal the following: (1) Green development performance is found to have a high degree of temporal and spatial path dependence, exhibiting spatial linkage between cities. (2) Market segmentation stemming from local government protection has a clear inverted U-shaped structure in relationship with the green development performance. (3) Our analysis suggests that the upgrading of industrial structures significantly enhances green development, while factor price distortion inhibits it. The relationship between market segmentation and industrial structure upgrading is also an inverted U-shape. (4) The analysis further reveals that market segmentation has an inverted U-shaped correlation with the green development performance in western, central, and eastern cities. However, the different rates of development of industrial structures within the three regions result in varying degrees of market segmentation according to inflection point values. Moreover, aligned with the theoretical hypothesis of "resource curse," in resource-based cities (exclusively), market segmentation still affects the green development performance with a significant inverted U-shaped structure.

Corrigendum to "Delivery of coenzyme Q10 loaded micelle targets mitochondrial ROS and enhances efficiency of mesenchymal stem cell therapy in intervertebral disc degeneration" [Bioact. Mater. 23 (2023) 247-260].

[This corrects the article DOI: 10.1016/j.bioactmat.2022.10.019.].

Manufacturing agglomeration, urban form, and haze pollution.

Manufacturing agglomeration promotes rapid economic development while also causing severe environmental pollution. This paper investigates the impact and mechanism of manufacturing agglomeration on haze pollution from the Chinese city level. Furthermore, we discuss the moderating effect and threshold effect of the three urban forms of urban external shape complexity, urban compactness, and urban fragmentation on the relationship between the two. The result shows the following: (1) The aggregation of the manufacturing industry presents an inverted U-shaped characteristic of promoting first and then inhibiting haze pollution in China's overall, eastern and central regions. (2) The complexity of the city's external shape and the city's fragmentation has a positive moderating effect on the relationship between manufacturing agglomeration and haze pollution. And urban fragmentation shows a negative moderating effect on the relationship between the two when the level of manufacturing agglomeration is on the right side of the inverted U-shaped curve. (3) The urban form shows a significant double threshold characteristic for haze pollution, increasing the complexity of the city's external shape and the city's fragmentation. The agglomeration of manufacturing shows the characteristics of first inhibiting and then promoting haze pollution. As urban compactness increases, the inhibitory effect of manufacturing agglomeration on haze pollution increases.

A biomimetic gradient porous cage with a micro-structure for enhancing mechanical properties and accelerating osseointegration in spinal fusion.

Objectives: Spinal fusion is a widely employed treatment of patients with degenerative disc disease, in which a cage is used to replace the disc for spinal fusion. But it often fails for insufficient mechanical strength and poor osseointegration. Here, we designed a polyether-ether-ketone (PEEK)/tantalum (Ta) composite cage with a biomimetic gradient porous micro-structure, simultaneously enhancing mechanical properties and accelerating osseointegration in spinal fusion. Materials and methods: In the study, based on the mechanical performances of PEEK and osteogenic potential of Ta, and the three-dimensional (3D) structures of cuttlebone and vertebra, the cages were respectively 3D printed by pure PEEK, PEEK with 5 wt% Ta (PEEK/Ta-5), PEEK with 10 wt% Ta (PEEK/Ta-10) and PEEK with 15 wt% Ta (PEEK/Ta-15), then verified in vitro and in sheep cervical fusion model systematically. Results: Vertebral Gyroid structure PEEK/Ta-15 cage exhibited superior mechanical properties than Cuttlebone-like structure PEEK/Ta-15 cage, closer to the cervical vertebra. Furthermore, PEEK/Ta-15 cage with higher Ta microparticles in PEEK provided a biomimetic gradient porous micro-structure with higher surface energy, guiding cell biological behavior, promoting new bone penetration, and accelerating osseointegration in vivo. Conclusion: In conclusion, the study designed a biomimetic gradient porous cage with a micro-structure for enhancing mechanical properties, accelerating osseointegration and forming an anatomical lock in the fusion segment through composites, mechanical efficiency, surface extension, and pores.

Delivery of coenzyme Q10 loaded micelle targets mitochondrial ROS and enhances efficiency of mesenchymal stem cell therapy in intervertebral disc degeneration.

Stem cell transplantation has been proved a promising therapeutic instrument in intervertebral disc degeneration (IVDD). However, the elevation of oxidative stress in the degenerated region impairs the efficiency of mesenchymal stem cells (BMSCs) transplantation treatment via exaggeration of mitochondrial ROS and promotion of BMSCs apoptosis. Herein, we applied an emulsion-confined assembly method to encapsulate Coenzyme Q10 (Co-Q10), a promising hydrophobic antioxidant which targets mitochondria ROS, into the lecithin micelles, which renders the insoluble Co-Q10 dispersible in water as stable colloids. These micelles are injectable, which displayed efficient ability to facilitate Co-Q10 to get into BMSCs in vitro, and exhibited prolonged release of Co-Q10 in intervertebral disc tissue of animal models. Compared to mere use of Co-Q10, the Co-Q10 loaded micelle possessed better bioactivities, which elevated the viability, restored mitochondrial structure as well as function, and enhanced production of ECM components in rat BMSCs. Moreover, it is demonstrated that the injection of this micelle with BMSCs retained disc height and alleviated IVDD in a rat needle puncture model. Therefore, these Co-Q10 loaded micelles play a protective role in cell survival and differentiation through antagonizing mitochondrial ROS, and might be a potential therapeutic agent for IVDD.

Hydroxytyrosol Ameliorates Intervertebral Disc Degeneration and Neuropathic Pain by Reducing Oxidative Stress and Inflammation.

Low back pain (LBP) seriously affects human quality of life. Intervertebral disc degeneration (IVDD) is the main pathological factor that leads to LBP, but the pathological mechanism underlying IVDD has not been fully elucidated. Neuropathic pain caused by IVDD is an important pathological factor affecting people's daily lives. Therefore, it is very important to identify therapeutic drugs to ameliorate IVDD and secondary neuropathic pain. Hydroxytyrosol (HT) is a natural compound derived from olive leaves and oil and has anti-inflammatory, antioxidant, and antitumor activities and other properties. In this study, TNF-α-stimulated human nucleus pulposus cells (HNPCs) were used to simulate the local inflammatory microenvironment observed in IVDD in vitro to explore the role of HT in alleviating various pathological processes associated with IVDD. A rat needle puncture model was used to further explore the role of HT in alleviating IVDD. Lipopolysaccharide (LPS) was used to stimulate microglia in vitro to comprehensively explore the role of HT in alleviating neuropathic pain, and a rat model involving chronic compression of the dorsal root ganglion (CCD) was established to simulate the neuropathic pain caused by IVDD. This study suggests that HT reduces the expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome, a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) and matrix metalloproteinase-13 (MMP-13); inhibits the production of mitochondrial reactive oxygen species (ROS); and maintains mitochondrial homeostasis. Thus, HT appears to reduce the rate of apoptosis and mitigate the loss of major intervertebral disc components by inhibiting the nuclear factor kappa-B (NF-κB) signaling pathway. Moreover, HT inhibited the secretion of COX-2, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1ß, and iNOS and activation of the NLRP3 inflammasome in microglia by inhibiting the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and extracellular regulated protein kinase (ERK) signaling pathways. In conclusion, HT plays a protective role against IVDD and secondary neuropathic pain by inhibiting the NF-κB, PI3K/AKT, and ERK signaling pathways.

Mangiferin Alleviates Mitochondrial ROS in Nucleus Pulposus Cells and Protects against Intervertebral Disc Degeneration via Suppression of NF-κB Signaling Pathway.

Intervertebral disc degeneration (IVDD), one of the most common clinical diseases worldwide, causes disc herniation and sciatica. Recent studies have identified the involvement of mitochondrial dysfunction, inflammatory responses, and extracellular matrix degradation in IVDD. Mangiferin is known to protect against various diseases by inhibiting oxidative stress, suppressing inflammation reaction, and relieving mitochondrial dysfunction. Whether mangiferin can alleviate IVDD remains to be elucidated. In the present study, human nucleus pulposus cells (HNPCs) and mouse intervertebral discs were cultured and stimulated with TNF-α, with or without treatment of mangiferin. Moreover, we established a rat needle puncture model and injected mangiferin into the intervertebral discs to verify its protective effect on IVDD. Furthermore, the activity of the NF-κB signaling pathway was tested in vitro. Our results indicated that mangiferin alleviated the inflammatory response and reversed the loss of major intervertebral disc components. Besides, mangiferin reduced reactive oxygen species production, ameliorated mitochondrial damage, and decreased the expression of apoptosis-related parameters in stimulation of TNF-α. In addition, mangiferin antagonized the activation of the NF-κB signaling pathway induced by TNF-α. Collectively, mangiferin antagonized mitochondrial ROS in NP cells and protected against IVDD by suppressing the activation of the NF-κB signaling pathway, which might provide a potential therapeutic instrument for IVDD.

Can Industrial Collaborative Agglomeration Reduce Haze Pollution? City-Level Empirical Evidence from China.

We analyze the mechanism for industrial co-agglomeration in Chinese 283 cities to affect haze pollution from 2003 to 2016 and examine the possible mediating effects of urbanization and energy structure between haze pollution and industrial co-agglomeration, finally obtaining the following results. First, industrial co-agglomeration and haze pollution across China, including central and eastern regions keep a typical inverted U-shaped curve relationship. That is, industrial co-agglomeration first promotes haze pollution and then restrains it. However, the impact of industrial co-agglomeration on haze pollution in western China is still on the left side of the inverted U-shaped curve, reflecting a promotion effect. Second, industrial co-agglomeration has a significant spatial spillover effect on haze pollution. Additionally, industrial co-agglomeration can promote haze pollution in local regions but inhibit it in surrounding regions in both the short and long run. In contrast, when the industrial co-agglomeration index exceeds the inflection point (3.6531), it benefits the reduction of haze pollution in local regions, while not being conducive to it in the neighboring regions. Third, industrial co-agglomeration can affect haze pollution through urbanization and energy structure, that is, urbanization and energy structure play an intermediary role between them.

Can Innovation Agglomeration Reduce Carbon Emissions? Evidence from China.

Innovation agglomeration plays a decisive role in improving the input-output scale and marginal output efficiency of factors. This paper takes carbon emissions as the unexpected output and energy consumption as the input factor into the traditional output density model. The dynamic spatial panel Durbin model is used to analyze the mechanism for innovation agglomeration and energy intensity to affect carbon emissions from 2004 to 2017 in thirty Chinese provinces. Then, we test the possible mediating effect of energy intensity between innovation agglomeration and carbon emissions. The major findings are as follows. (1) The carbon emission intensity has time-dependence and positive spatial spillover effect. That is, there is a close correlation between current and early carbon emissions, and there is also a high-degree correlation between regional and surrounding areas' carbon emissions. (2) Carbon emissions keep a classical inverted U-shaped relation with innovation agglomeration, as well as with energy intensity. However, the impact of innovation agglomeration on carbon emissions in inland regions of China does not appear on the right side of the inverted U-shaped curve, while carbon emissions are subject to a positive nonlinear promoting effect from energy intensity. (3) When the logarithm of innovation agglomeration is more than 3.0309, it first shows the inhibition effect on energy intensity. With the logarithm of innovation agglomeration exceeding 5.0100, it will show the dual effect of emission reduction and energy conservation. (4) Energy intensity could work as the intermediary variable of innovation agglomeration's influence on carbon emissions. Through its various positive externalities, innovation agglomeration can produce a direct impact on carbon emissions, and through energy intensity, it can also affect carbon emissions indirectly.

Quadratic Meta-Reflectors Made of HfO2 Nanopillars with a Large Field of View at Infrared Wavelengths.

Metasurfaces, being composed of subwavelength nanostructures, can achieve peculiar optical manipulations of phase, amplitude, etc. A large field of view (FOV) is always one of the most desirable characteristics of optical systems. In this study, metasurface-based quadratic reflectors (i.e., meta-reflectors) made of HfO2 nanopillars are investigated to realize a large FOV at infrared wavelengths. First, the geometrical dependence of HfO2 nanopillars' phase difference is analyzed to show the general principles of designing infrared HfO2 metasurfaces. Then, two meta-reflectors with a quadratic phase profile are investigated to show their large FOV, subwavelength resolution, and long focal depth. Furthermore, the two quadratic reflectors also show a large FOV when deflecting a laser beam with a deflecting-angle range of approximately ±80°. This study presents a flat optical metamaterial with a large FOV for imaging and deflecting, which can greatly simplify the optical-mechanical complexity of infrared systems, particularly with potential applications in high-power optical systems.

IL-38 alleviates the inflammatory response and the degeneration of nucleus pulposus cells via inhibition of the NF-κB signaling pathway in vitro.

Previous studies have suggested that the inflammatory response contributes to the onset of intervertebral disc degeneration (IVDD). Interleukin (IL)-38, a newly discovered cytokine of the IL-1 family, has been demonstrated to play an anti-inflammatory role in autoimmune diseases, such as Crohn's disease, rheumatoid arthritis and psoriasis. However, whether IL-38 participates in the pathogenesis of IVDD remains unknown. In this study, human disc tissues from IVDD patients and rat disc tissues from an IVDD model were collected to measure the expression of IL-38 in the IVDD groups and the control groups by western blot and immunohistochemical staining. To further determine the role of IL-38 in IVDD, human nucleus pulposus cells (HNPCs) were stimulated with TNF-α to generate an in vitro model of inflammation to mimic the local inflammatory environment of the lumbar disc. The inflammatory response and HNPC degeneration markers were measured after stimulation with TNF-α and IL-38. IL-38 was upregulated in both the human and rat degenerated disc tissues compared with the control tissues. In vitro, IL-38 significantly decreased the TNF-α-induced expression of IL-1ß, IL-6, COX-2, MMP-13 and ADAMTS-5 in the HNPCs, and IL-38 also alleviated the TNF-α-induced reductions in type II collagen and aggrecan. Moreover, IL-38 inhibited the activation of the NF-κB signaling pathway in the HNPC-based model of inflammation by reducing the expression level of the NF-κB P-P65 protein. In conclusion, IL-38 could alleviate the inflammatory response and HNPC degeneration in vitro via the inhibition of the NF-κB signaling pathway. These results suggest that IL-38 may be a new strategy for the treatment of IVDD.

Ultrafast plasmonic lasing from a metal/semiconductor interface.

To date, plasmonic nanowire lasers mostly adopt hybrid plasmonic waveguides, while there is a lack of study in terms of the confinement effect and the corresponding ultrafast dynamics of non-hybridized plasmonic lasers. Here, we report ultrafast plasmonic nanowire lasers composed of a single CH3NH3PbBr3 nanowire on a silver film without any insulating layer at room temperature. The non-hybridized plasmonic nanowire lasers exhibit ultrafast lasing dynamics with around 1.9 ps decay rate and 1 ps peak response time. Such values are among the best ones ever reported. Interestingly, the threshold of the non-hybridized plasmonic nanowire lasers is in the same order as that of their hybrid counterparts. The low threshold is due to the ultra-flat single-crystal silver films and high-quality single-crystal perovskite nanowires. The non-hybridized plasmonic lasing in CH3NH3PbBr3 nanowires originates from the stimulated emission of an electron-hole plasma based on our experiments. This work deepens the understanding of non-hybridized plasmonic lasers and paves the way to design electric pump plasmonic lasers by getting rid of insulating layers.

[Evaluation and analysis of high-quality products of Liuwei Dihuang Pills].

Liuwei Dihuang Pills is a typical traditional Chinese medicine with "the same product made by many manufacturers". The quality and price of products made in various factories was different obviously. In this study, the quality differences of Liuwei Dihuang Pills were evaluated over multi-dimensions and throughout the whole production cycle involving raw materials, production process, quality control and post-marketing re-studies based on the "Chinese patent medicine evaluation standard with quality at the core" established earlier by our research group. The research results showed that the product quality of various manufacturers was significantly different, and the product quality was positively correlated with the market shares of enterprises, indicating that enterprises with more market shares paid more attention to product quality; and the sales determined the concern degree of enterprises on products, which was in line with general cognition. During the single-item evaluation of Liuwei Dihuang Pills, the score of raw material selection was relatively low, and the enterprises paid less attention to the initial raw materials. The whole production process was better, and the national compulsory implementation of "Production Quality Management Standard"(GMP) had a positive effect in improving product quality. Quality control could basically guarantee product quality. Intelligent manufacturing promoted by the government was beneficial to ensure product uniformity. The score rate of "quality evaluation" item was basically qualified, which indicated that the quality control level of Liuwei Dihuang Pills was acceptable as a whole, but there was still room for improvement. "Re-evaluation and Brand Construction" had the lowest scores, reflecting that enterprises did not pay enough attention to in-depth study and re-evaluation of "the same product made by many manufacturers". The evaluation results were in line with expectations, provided a reference example for the evaluation of high-quality Chinese patent medicine, a basis for the high-quality and good price of Chinese patent medicine, scientific data for improving medical insurance bidding, and thus facilitated promoting the healthy development of the traditional Chinese medicine industry.

Confined geometry and laser energy affect laser plasma propulsion.

The interaction of plasma (or shock waves) with the uniform sphere shape of polystyrene particles was investigated in this study to observe the effects of confined geometry and energy fluence on propulsion efficiency. The measurements indicate that propulsion efficiency first increases with energy fluence until reaching a maximum at 0.46 J/cm2, then decreases as energy fluency continues to increase. Compared to polystyrene particle propulsion without confined geometry, the propulsion efficiency of polystyrene particles improved due to multiple laser-induced shock wave reflections among the confined geometry internal face; the plasma propelling force also increased perpendicular to the target surface under confined geometry conditions. The results also show that the energy deposited on the plasma affects the energy distribution between the plasma and polystyrene particle. Moreover, a series of experiments was performed to roughly estimate the shock wave expansion shape through the motion direction of the polystyrene particle swarm, where the shock wave was observed to expand spherically.

[Research on evaluation criteria over quality as core index of high grade Chinese patent medicine].

"One drug was produced by many companies" is common in Chinese patent medicines. The quality and price of products from different manufacturers varies widely, and the efficacy is inconsistency. In order to ensure the quality of Chinese patent medicines and promote "Healthy national program" implementation, it is necessary to study the current status of Chinese patent medicines and carry out the evaluation criteria over quality as the core management of high grade Chinese patent medicines, which is set up to reflect the evaluation strategy and method of Chinese patent medicines from raw material, production, quality control, reevaluation and competitive power to the whole chain of brand construction. It aims to reveal the quality discrepancy from different manufacturers over the same Chinese patent medicines. The research and application will select a serials of high grade quality products, and provide reference basis for the scientific and reasonable price formation mechanism of Chinese patent medicines and purchasing drugs by centralized bidding, guide healthy competition in the market and promote the implementation of "healthy China 2030 program".

Micro-gun based on laser pulse propulsion.

This paper proposes a novel "micro-gun" structure for laser pulse propulsion. The "micro-bullets" (glass microspheres) are irradiated by a laser pulse with a 10 ns duration in a dynamic process. Experimental parameters such as the microsphere diameter and the laser pulse energy are varied to investigate their influence on laser pulse propulsion. The energy field and spatial intensity distribution in the capillary tube were simulated using a three-dimensional finite-difference time-domain method. The experimental results demonstrate that the propulsion efficiency is dependent on the laser pulse energy and the microsphere size. The propulsion modes and sources of the propelling force were confirmed through direct observation and theoretical calculation. Waves also generated by light-pressure and thermal expansions assisted the propulsion.

Organic-inorganic perovskite plasmonic nanowire lasers with a low threshold and a good thermal stability.

Plasmonic nanolasers have ushered in a paradigm of deep sub-wavelength coherent optical sources with ultrafast dynamics that exploit the strong confinement capabilities of metals. Although these devices are usually associated with higher thresholds due to absorption in metals, the high gain inorganic II-VI and III-V semiconductor materials have allowed the realization of plasmonic nanolasers operating under ambient conditions. In this work, we introduce single-crystalline lead halide perovskite (CH3NH3PbI3) nanowires as an organic-inorganic semiconducting gain material to the plasmonic laser community. We demonstrate plasmonic laser action using a hybrid geometry whereby the perovskite nanowires are placed on a silver substrate with an insulating spacer layer. We report relatively low threshold operation under ambient conditions (13.5 µJ cm-2), and the devices work well even at temperatures up to 43.6 °C. The demonstration highlights the high optical gain achievable in perovskite materials and thus provides a solution to high gain materials for plasmonic devices.