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Interpopulation variability in seed traits may drive the regeneration capacity of a species to colonize different environments. In the present study, we evaluated the variation in seed physical traits (mass / size, water imbibition, shape index) and physiological traits (germination) of five Polygonaceae species. Seeds of Polygonum lapathifolium var. salicifolium, P. lapathifolium, Reynoutria japonica, Rumex trisetifer, and R. obtusifolius were collected from two or three populations in Jiujiang, China. Physical seed traits were measured before germination tests conducted under different combinations of light and temperatures. Most species had a significant variation in seed physical and physiological traits, although populations are geographically close. Interpopulation variation in seed traits appeared to be species-specific, with the highest variation for R. japonica and lowest for R. trisetifer seeds. Germination response to temperature and light conditions also varied among species and populations, being mostly inhibited in the dark treatments. The light dependence of germination can be related to the small seed size, except for the round-seeded Rumex, depending on the temperature regime. Optimal temperature ranges mainly varied from 10/20°C to 25/35°C, with significant decreases in germination percentage at both coolest and warmest extremes. Germination requirements seem to be related to altitudinal gradients in populations of P. lapathifolium and R. japonica seeds.

Additional file 1. Figure S1:.Consolidated Standards of Reporting Trialsdiagram illustrating the selection and exclusion of patients

Brain disorders, including stroke, Alzheimer's disease, depression, and chronic pain, are difficult to effectively treat. These major brain disorders have high incidence and mortality rates in the general population, and seriously affect not only the patient's quality of life, but also increases the burden of social medical care. Aerobic physical exercise is considered an effective adjuvant therapy for preventing and treating major brain disorders. Although the underlying regulatory mechanisms are still unknown, systemic processes may be involved. Here, this review aimed to reveal that aerobic physical exercise improved depression and several brain functions, including cognitive functions, and provided chronic pain relief. We concluded that aerobic physical exercise helps to maintain the regulatory mechanisms of brain homeostasis through anti-inflammatory mechanisms and enhanced synaptic plasticity and inhibition of hippocampal atrophy and neuronal apoptosis. In addition, we also discussed the cross-system mechanisms of aerobic exercise in regulating imbalances in brain function, such as the “bone-brain axis.” Furthermore, our findings provide a scientific basis for the clinical application of aerobic physical exercise in the fight against brain disorders.

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With the continuous development of artificial intelligence technology, image semantic segmentation has increasingly become the focus of computer vision and artificial intelligence algorithms. Image semantic segmentation technology has been applied in remote sensing satellite images, agricultural products production, medical diagnosis and treatment and other fields, and these fields need very accurate and effective semantic segmentation technology. This paper summarizes the common semantic segmentation techniques, introduces the main algorithms of image semantic segmentation techniques, mainly explains the image semantic segmentation techniques based on traditional machine learning and image semantic segmentation techniques based on deep learning, expounds the structure of each method, summarizes the performance and effect of each method, and finally expounds our views on the future development direction and challenges of semantic segmentation.

Grasshopper optimization algorithm is one of the latest swarm intelligence algorithms, however it is easy to fall into the local optimum and has the defect of poor search ability. Therefore, Gaussian and chaos theory are combined to improve the original grasshopper optimization algorithm. Firstly, the Sinusoidal chaotic map is used to initialize the solution space of the population; then, Gaussian and Logistic chaotic map are used to improve the position update formula of grasshopper optimization algorithm; finally, eight benchmark numerical test functions are used to verify and test the search performance of this algorithm with ALO, PSO, GOA. It can be seen from the experimental data that the improved grasshopper optimization algorithm has better convergence accuracy and stability than the other three swarm intelligent algorithms. Besides, GC-GOA has good performance in the design of three-bar truss problem.

A series of environmentally nontoxic near-infrared reflective pigments of BiVO4 coated mica-titanium oxide were synthesized. The pigments were characterized by XRD, FE-SEM, UV–vis-NIR spectrophotometer and CIE L∗ a∗ b∗ color scales. The results illustrated that the BiVO4 particles with a size of ∼500 nm were firmly adhered to mica-titanium oxide substrate. Additionally, the composite pigments change the color from white to bright yellow with the increase of the BiVO4 loadings. All the pigments had higher NIR reflectance than conventional yellow pigment (≥70.0%). In the simulated experiment, the temperature difference of the inner surface temperature of coatings and the interior air temperature of boxes reached 4.5 °C and 2.3 °C, respectively, indicating that the good thermal insulation performance of the sample coating (30% BiVO4) could be used as building roof material to reduce the heat buildup and decrease the indoor temperature. Furthermore, we also evaluated aging resistance of the pigments. In conclusion, BiVO4 coated mica-titanium oxide composite pigments have great potential in serving as cool materials for building coatings and they also meet energy-saving and environmentally friendly requirements.

In this study, based on the finite-time unknown input observer (FT-UIO), the problem of distributed fault diagnosis (FD) for multi-agent systems (MAS) with actuator faults and disturbances is investigated. Firstly, using the communication topology and local information, the global multi-agent system dynamics are represented with respect to a certain agent. Then, in order to construct a FT-UIO at the selected agent, the system will be decomposed into three subsystems after coordinate transformation. Furthermore, constituted by two distinct observers, the FT-UIO is designed to converge in a pre-assigned finite time, which is chosen as the time delay of the observers. With the state estimation obtained from the FT-UIO in the selected agent, a FD algorithm is also proposed to diagnose the faults occurred in its neighbor agents. Finally, simulation results are presented to illustrate the effectiveness and advantages of the proposed FT-UIO-based distributed FD scheme for MAS.

A new environmentally benign near-infrared reflectance pigment based on BiFeO3 doped with La3+ was described. The pigments of the formula Bi1-xLaxFeO3 (x = 0, 0.1, 0.2, 0.3, 0.4) were characterized by XRD, FE-SEM, TG-DTA, UV-vis-NIR spectrophotometer and CIE L∗a∗b∗ color scales. The results reveal that the pigments crystallized at 600 °C with particle size less than 70 nm. The substitution of La3+ for Bi3+ in BiFeO3 shift the color from dark brown to reddish brown and the band gap decrease from 2.24 to 2.03 eV due to O2p-Fe3d charge transfer transitions. The near-infrared solar reflectance of the powdered pigments increased with the increase of progressive doping of La3+ for Bi3+. The pigment coated on concrete cement substrate exhibit higher near-infrared solar reflectance (R∗ ≥ 44.1%) than conventional coating of similar color. Moreover, the thermal and chemical stability of the pigments were also evaluated. In conclusion, the pigments have the potential to be applied as “cool pigments”.

A series of novel nontoxic near-infrared (NIR) reflective pigments based on Al-doped BiFeO3 coated mica-titania were synthesized by precipitation combined with sol-gel method. The pigments of the formula BiFe1−xAlxO3/mica-titania (x = 0, 0.1, 0.2, 0.3, 0.4) were characterized by XRD, FE-SEM, TG-DTA, UV–vis–NIR spectrophotometer and CIE L* a* b* color scales. The results illustrate that the BiFeO3 nanoparticles are coated on the surface of mica-titania uniformly, and the doped BiFe1−xAlxO3/mica-titania is similar to BiFeO3/mica-titania composite in morphology. Furthermore, the absorption edge of composite pigments shift to shorter wavelength (533–495 nm) can be attributed to O2p-Fe3d charge transfer transitions and change the color of the pigments from brown to orange. Additionally, the NIR solar reflectance of the powdered pigments and pigmented coatings were measured. The results reveal that with the increase of progressive doping of Al3+ for Fe3+, the NIR solar reflectance of the pigments increase gradually and exhibit higher NIR solar reflectance (R* ≥ 47.8%) than the conventional pigment of similar color. Moreover, we also evaluated the thermal and chemical stability of the pigments. In conclusion, the pigments have the potential to be applied as “cool pigments”.

In this study, a series of Mn-doped ZnAl 2 O 4 and Mn/N co-doped ZnAl 2 O 4 were synthesized by the sol-gel method. Comprehensive analyses of compounds and coatings were carried out to characterize results. Several colored inorganic samples are studied, including their ability as cool pigments. The results show that prepared compounds exhibit different spectral reflectance extents in the near-infrared region despite their structural similarities, which illustrates the near-infrared reflective properties are dependent on the doping elements. The different doping has an effect on the thermal performance, especially in the visible and near-infrared regions. The substitution of Mn/N changed the color from white to flesh color, while the band gap varies in the range from 3.64 ev to 2.90 ev. Furthermore, the Mn/N co-doped ZnAl 2 O 4 compounds exhibit high near-infrared reflectance (>50%) and the near-infrared solar reflectance (>48.83%) in the range of 700–2500 nm. We also evaluated the thermal performance of Mn/N co-doped ZnAl 2 O 4 and conventional pigment coatings of the same color by testing the temperature distribution at different parts of the aluminum plates. It indicates that the prepared compounds have the potential to be applied to energy savings as novel color pigments.

To obtain cool materials as inorganic and nontoxic pigments with high near-infrared reflectance, nano-powder of Fe/N co-doped MgTiO 3 (FNM), were synthesized by the sol-gel method. The substitution of Fe/N changed the color from white to dark-red due to the point defect equilibrium theory, while the band gap decreased from 2.11 ev to 1.89 ev. Ammonolysis reaction can promote the particle dispersion and increase the particle size. Furthermore, the FNM pigments exhibit high NIR reflectance (>65%) and the NIR solar reflectance (>53.51%) in the range of 700–2500 nm. After the prepared pigments (N-doped Mg 1−x Fe x TiO 3+δ , x=0.3) and conventional brown pigments used as building roof materials, the temperature difference of coatings could reach 2.4 °C (the inner surface temperature of substrate plates) and 2.0 °C (the interior temperature of the two boxes), respectively. Moreover, the surface temperature distribution of the coatings was recorded by infrared images and the difference (ΔT) varied at 0–12 °C. According to the maximum value of coatings (x=0.3), energy savings would reduce annual emissions of 1379.35 t carbon dioxide, 41.65 t nitrogen oxides and 34.30 t sulfur oxides. Owing to the wide range of color and good chemical stability, which meets reflectance of solar radiation energy and cooling energy needs, these FNM materials are considered as novel color pigments.

Large discharge of chromium and chloride is a severe pollution source in conventional leather-making industry, which hinders the sustainable development of leather industry and affects human life greatly. Aiming at minimizing the emissions of chromium and chloride, novel materials rich in sulfonic acid group were synthesized and optimized in salt-free pickling and less chrome tanning process. The results showed that, the novel method would improve the chromium absorption and distribution in crust leather from 7 1 .6% to 98.6%, in comparison with conventional pickling chrome tanning, and the concentration of residual chromium in spent liquor was decreased to 45 mg/L. The SEM indicated that the resulting leather treated with novel salt-free pickling showed clean pores and well-dispersed fibrils. Further experiment proved this novel salt-free pickling and less chrome tanning method is feasible in terms of organoleptic and physical mechanical properties. The financial assessment showed that the novel method is 46.9% cheaper than conventional approach. This novel pickling chrome tanning method can successfully solve the emission of chromium and chloride as well as obtain cleaner products in leather-making industry.

Purpose: To investigate the expression of Yes-associated protein 1 (YAP1) in bladder cancer, and to study its role in regulating epithelial-mesenchymal transition in bladder cancer cells. Material and methods: The expression of YAP1, vimentin, and E-cadherin was detected by immunohistochemistry in bladder cancer and para-carcinoma tissues. The relation between expression levels and overall survival of patients was evaluated by Kaplan-Meier estimates. Furthermore, YAP1 expression was knocked down in T24 and UMUC3 bladder cancer through transfection with YAP1-targeted small interfering RNA (siRNA), and the impact on invasiveness and epithelial-mesenchymal transition was detected. Results: Expression levels of YAP1 were higher in bladder cancer tissues, and increased YAP1 expression significantly correlated with poor patient outcomes and poor overall survival in bladder cancer patients. Furthermore, YAP1 siRNA significantly attenuated the invasion of bladder cancer cells and could reverse their epithelial-mesenchymal transition. Conclusion: YAP1 appears to play an important role in bladder cancer progression and is highlighted as a novel potential therapeutic target.

The scattering spectra and intensity of gold nanorods placed at varied distances above gold films have been simulated and measured under various conditions, demonstrating that scattering characteristics of the nanorod-film system are highly dependent on illumination conditions. Studying the surrounding electric fields of nanorods reveals that the illumination-dependent properties of the system are induced by the interference in the nanorod-film system. Both simulations and experiments show that optimising the nanorod-film distance can greatly enhance scattering magnitudes up to ~20 times for certain illumination conditions. We propose an application of the studied system in facilitating photo-thermal conversion.

The plasmonic resonances in individual gold nanorods nanoscopically coupled to a gold film with different gap spacing have been experimentally and theoretically investigated. The spectral widths, wavelengths, and optical polarizabilities of the maxima in measured single-nanoparticle scattering spectra are significantly modified as the gap distance changes in the sub-20 nm domain. Comparing the experimental data with numerical simulations reveals that these modifications arise from the complex hybridization of several dipolar and multipolar plasmon modes that are strongly localized at the gap. These plasmon gap modes have distinct resonant and spatial characteristics as a result of near-field interaction between the elongated nanorods and the gold film. Additionally, the excitation of these gap modes is highly dependent on the gap spacing. Finally, we also discuss influences of these plasmonic modes on absorption properties of the system and propose a potential application of the studied structures in faci...

Nanostructures with various configurations have been extensively used to engineer the emission properties of embedded fluorophores, but lack the flexibility to dynamically control fluorescence. Here we report a thin-film cavity system, comprising a quarter wavelength thick dye-doped dielectric coating on a reflecting surface, in which the fluorescence enhancement and directionality can be significantly modified by altering the illumination angle. The configuration of the cavity yields absorption properties that are highly dependent on illumination angles, due to the coupling between molecular absorption and Fabry-Perot resonances. Therefore the fluorescence intensity relating to the angle-dependent absorbing efficiency varies with illumination angles. In addition, as a result of synergy between intrinsic absorption of the reflecting surface, Fabry-Perot and surface-plasmon-polariton resonances and illumination-angle dependent excitation efficiencies for differently located molecules, the global emission intensity, including emission from dyes at all locations, can be directionally redistributed by altering the illumination angle.

This paper concerns with the robust finite-time fault diagnosis of leader-follower multi-agent systems with actuator faults. Using linear matrix inequality (LMI) and robust finite-time boundedness theory, a sufficient condition is firstly presented for a dynamic system to be robust finite-time bounded. The observer is constructed based on relative output estimation error. Then the existence conditions of robust finite-time fault diagnosis observers are shown by means of LMI. According to the solution of LMI, the design method of the observer is given. Finally, two examples are given to illustrate the effectiveness of the proposed method.

Plasmonic cavities can be used to control the atom-photon coupling process at the nanoscale, since they provide an ultrahigh density of optical states in an exceptionally small mode volume. Here we demonstrate strong coupling between molecular excitons and plasmonic resonances (so-called plexcitonic coupling) in a film-coupled nanocube cavity, which can induce profound and significant spectral and spatial modifications to the plasmonic gap modes. Within the spectral span of a single gap mode in the nanocube-film cavity with a 3 nm wide gap, the introduction of narrow-band J-aggregate dye molecules not only enables an anticrossing behavior in the spectral response but also splits the single spatial mode into two distinct modes that are easily identified by their far-field scattering profiles. Simulation results confirm the experimental findings, and the sensitivity of the plexcitonic coupling is explored using digital control of the gap spacing. Our work opens up a new perspective to study the strong coupling process, greatly extending the functionality of nanophotonic systems, with the potential to be applied in cavity quantum electrodynamic systems.

Summary Background Predictors of quantitative evaluation of hepatic steatosis and liver fat content (LFC) using clinical and laboratory variables available in the general practice in the obese children are poorly identified. Objective To build predictive models of hepatic steatosis and LFC in obese children based on biochemical parameters and anthropometry. Methods Hepatic steatosis and LFC were determined using proton magnetic resonance spectroscopy in 171 obese children aged 5.5–18.0 years. Routine clinical and laboratory parameters were also measured in all subjects. Group analysis, univariable correlation analysis, and multivariate logistic and linear regression analysis were used to develop a liver fat score to identify hepatic steatosis and a liver fat equation to predict LFC in each subject. Results The predictive model of hepatic steatosis in our participants based on waist circumference and alanine aminotransferase had an area under the receiver operating characteristic curve of 0.959 (95% confidence interval: 0.927–0.990). The optimal cut-off value of 0.525 for determining hepatic steatosis had sensitivity of 93% and specificity of 90%. A liver fat equation was also developed based on the same parameters of hepatic steatosis liver fat score, which would be used to calculate the LFC in each individual. Conclusions The liver fat score and liver fat equation, consisting of routinely available variables, may help paediatricians to accurately determine hepatic steatosis and LFC in clinical practice, but external validation is needed before it can be employed for this purpose.

Hypersonic chemical non-equilibrium gas flows around blunt nosed bodies are studied in the present paper to investigate the Reynolds analogy relation on curved surfaces. With a momentum and energy transfer model being applied through boundary layers, influences of molecular dissociations and recombinations on skin frictions and heat fluxes are separately modeled. Expressions on the ratio of Cf / Ch (skin friction coefficient to heat flux) are presented along the surface of circular cylinders under the ideal dissociation gas model. The analysis indicates that molecular dissociations increase the linear distribution of Cf / Ch, but the nonlinear Reynolds analogy relation could ultimately be obtained in flows with larger Reynolds numbers and Mach numbers, where the decrease of wall heat flux by molecular recombinations signifies. The present modeling and analyses are also verified by the DSMC calculations on nitrogen gas flows.

The present study was to investigate the effect of proactive personality (PAP) and cognitive flexibility (CF) on the student pilots' situational judgment. This study was based on a sample of 222 student pilots from Civil Aviation Flight University of China. The results showed that proactive personality directly affected student pilots' situational judgment. Cognitive flexibility had the moderating effect on the relationship between PAP and situational judgment. Implications of the study as well as future research directions on the study of student pilot's situational judgment are discussed.

Metasurfaces, which consist of resonant metamaterial elements in the form of two-dimensional thin planar structures, retain great capabilities in manipulating electromagnetic wave and potential applications in modifying interaction with fluorescent molecules. The metasurfaces with magnetic responses are favorable to weakening fluorescence quenching while less investigated in controlling fluorescence. In this paper, we demonstrate control over fluorescence emission by engineering the magnetic and electric modes in plasmonic metasurfaces consisting of 45-nm-thick gold split-ring-resonators (SRRs). The fluorescence emission exhibits an enhancement factor of ∼18 and is predominantly x-polarized with assistance of the magnetic mode excited by oblique incidence with an x-polarized electric field. The magnetic and electric modes excited by oblique incidence with a y-polarized electric field contribute to the rotation of emission polarization with respect to the incident polarization. The results demonstrate manipulating the interaction of fluorescent emitters with different resonant modes of the SRR-based metasurface at the nanoscale by the polarization of incident light, providing potential applications of metasurfaces in a wide variety of areas, including optical nanosources, fluorescence spectroscopy and compact biosensors.

We review here our recent studies on plasmonic enhanced photothermal effects in metallic nanostructure, and the applications of such effects. When light is shined on a prefect metamaterial absorber patterned with e-beam lithography, the gold nanoparticles (NPs) forming the absorber can be either transformed to nano-spherical-domes, or to truncated-octahedral shaped or multi-twined nanocrystals with large crystal grain sizes and flat boundary facets. The evolution of morphology and crystallinity of the gold NPs can be also observed. Evidences clearly show that the surface melting and the coalescence mechanism play a key role on nanocrystals formation. These melted gold nanospheres can even be transferred to another substrate, on which the transferred NPs exhibit excellent size uniformity. The strong photothermal effects can also be utilized to tune silicon photonics waveguides and resonators. It is shown that all-optical photothermal switching of Mach-Zehnder interferometers (MZI), silicon disk resonators, and silicon ring resonators is possible with the help of plasmonic nanoheaters. The switching response time and power consumption are all at reasonably low level.

We experimentally demonstrate the strongly enhanced photoluminescence of the fluorescent molecules on the metamaterial mirror. The matematerial mirror can optimize the reflection phase to provide a large electric field for the 20-nm-thick active layer. Compared with the smooth gold plate, the experimental result shows a nearly 45 times enhancement.

Au nanoparticles show large third-order nonlinear effect and ultra-fast response. Here a high nonlinear aggregate film based on self-assembled gold nanoparticles is reported and its third-order nonlinear refractive index coefficient is measured by Z-scan experiment. The third-order nonlinear refractive index coefficient of the Au nanoparticle aggregate film (γ1 = 9.2 × 10−9 cm2/W) is found to be larger than that of an 8-nm-thick sputtered Au film (γ2 = 6.5 × 10−9 cm2/W). This large nonlinear effect can be attributed to the strong field enhancement due to localized plasmon resonances between Au nanoparticles. The result shows that the self-assembled Au nanoparticle aggregate film could be a promising candidate as a third-order nonlinear optical material.

An ultra-narrow band absorber consisting of continuous silver and alumina films is investigated. Owing to Fabry–Perot resonance and silver's inherent loss, an ultra-narrow spectral range of light can be entirely trapped in the structure. By varying thicknesses of metallic and dielectric films, absorption peak shifts in visible and near-infrared regions. When two such metal-insulator-metal stacks are cascaded, experimental results show that an ultra-narrow absorption bandwidth of 7 nm is achieved, though theoretical results give that of 2 nm. Features of high-efficiency and ultra-narrow band absorption have huge potential in optical filtering, thermal emitter design, etc.

In this paper, we experimentally demonstrate enhanced optical transmission through a seamless gold film based on the grating-insulator-metal (GIM) architecture. The transmittance of this GIM structure reaches 40% at 930 nm, showing 3.7 dB and 9.1 dB increase compared with a bare gold film and a continuous metal-insulator-metal stack, respectively. The enhanced transmission is polarization-sensitive and robust for oblique incidence. With tunable transmission peaks, such a device exhibits great potential for applications in optical filtering, polarization detecting and further integration in optoelectronics system.

Turning the surfaces of noble metals (metasurfaces) into black (highly absorptive) surfaces can be potentially applied in thermophotovoltaics, sensing, tailoring thermal emissivity, etc. Here we demonstrate an extremely broadband absorber for the 900-1600 nm wavelength range with robust high absorption efficiency. The inexpensive droplet evaporation method is implemented to create patterns of nanoparticles dispersed on a gold film spaced by a thin dielectric layer. The diversity of the complicated random stacking of the chemically synthesized gold nanorods is the major factor for the broad absorption band. Such a metamaterial absorber may pave the way for cost-effective manufacture of large-area black metasurfaces.