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This study aimed to assess the clinical efficacy of umbilical cord mesenchymal stem cells (hUC-MSCs) from different passages (P3, P8, and P13) in the treatment of knee osteoarthritis (OA) and explore the underlying mechanisms. The hUC-MSCs from each passage were characterized and evaluated for their stemness, migration, proliferation, and marker expression. Rats with OA were treated with hUC-MSCs from each passage, and the therapeutic effects were assessed based on knee swelling, discomfort, and pathological examination of the knee joint. Co-culture experiments were conducted to examine the ability of hUC-MSCs to stimulate type II collagen synthesis and inhibit MMP13 expression in chondrocytes. Telomere length and telomerase activity of hUC-MSCs from each passage were measured to investigate the reasons for the observed differences in clinical efficacy. The results revealed that P3 and P8 hUC-MSCs exhibited superior osteogenic and chondrogenic differentiation potential compared to P13, while P13 demonstrated stronger adipogenic differentiation. The wound healing rate was significantly higher in the P3 and P8 groups compared to P13. All hUC-MSC groups expressed high levels of CD90 and CD105, indicating their mesenchymal stem cell characteristics, while CD31 and CD45 were not expressed. CD105 expression was significantly reduced in the P13 group. In the treatment of rat osteoarthritis, there were no significant differences in knee swelling, discomfort, Mankin scores, and pathological findings between P3 and P8 hUC-MSC treatments. However, there was a significant difference between the 8th and 13th passages. Co-culture experiments showed that hUC-MSCs from P3 and P8 enhanced type II collagen synthesis and reduced MMP13 expression in chondrocytes. Although no significant difference was observed between the P3 and P8 groups, a significant difference was found between the P13 and P8 groups. Telomere length analysis revealed that P13 samples had significantly shorter telomeres compared to both P3 and P8. The telomerase activity was positive in P3 and P8 hUC-MSCs, indicating no significant difference between these passages, while it was negative in P13 hUC-MSCs. In conclusion, P3 and P8 hUC-MSCs exhibited superior therapeutic potential for knee osteoarthritis compared to P13, possibly due to their enhanced differentiation capacity and telomerase activity. [Display omitted] • The adipogenic capacity of hUC-MSCs increases with passaging, while their osteogenic and chondrogenic capacities decrease. • Animal experiments showed that there was no statistically significant difference in the therapeutic effects of P3 and P8 stem cells in the treatment of mouse osteoarthritis. However, there was a statistically significant difference between P13 and P8. • As the number of passages increases, the changes in telomerase activity and telomere length become more pronounced. • Telomere length and activity can partially reflect the therapeutic effectiveness of hUC-MSCs. [ABSTRACT FROM AUTHOR]

[Display omitted] • ● A cycloaliphatic epoxy-functionalized polydimethylsiloxane (PDMS-CE) was synthesized. • ● PDMS-CE modified epoxy (EP/PDMS-CE) thermosets were fabricated. • ● EP/PDMS-CE thermosets showed a slight increase in T d5% and T g. • ● EP/PDMS-CE thermosets showed a significant improvement in toughness. • ● PDMS-CE is a promising and all-purpose modifier for epoxy thermosets. Polydimethylsiloxane (PDMS) are known as a class of efficient modifiers for epoxy thermosets, but the simultaneous improvement in thermal stability, thermomechanical and mechanical properties remain a challenge. Herein, we report a cycloaliphatic epoxy-functionalized polydimethylsiloxane (PDMS-CE) with a designed epoxy value for comprehensive modifications of diglycidyl ether of bisphenol A (DGEBA)/methylhexahydrophthalic anhydride (MeHHPA) thermosets. Compared to neat epoxy thermoset, the 4 wt% PDMS-CE modified epoxy thermoset showed a 79 %, 120 % and 503 % increase in flexural strength, impact strength and fracture toughness, respectively, as well as a slight increase in the initial thermal decomposition temperature (T d5%) and glass transition temperature (T g), and a desirable decrease in the dielectric constant and water absorption rate. This comprehensive modification performance was caused by the combined effects of crosslinking density improvement, rigid cycloaliphatic structure, as well as the flexible PDMS chains. [ABSTRACT FROM AUTHOR]

Using the transimissivity between two thermal reservoirs and the generalized Planck distributions, we describe the devices that use radiative energy transfer between thermal reservoirs in a unified formalism. Four types of devices are distinguished. For power generators that use the temperature difference between reservoirs, photovoltaic (PV) and thermoradiative (TR) devices respectively use the low-temperature photovoltaic cell and high-temperature thermoradiative cell to generate electricity. For active cooling, the electroluminescent (EL) cooling devices apply a forward bias voltage on the object we want to cool, whereas the negative EL cooling devices apply a reverse bias voltage to the heat sink. The relationship among these four devices is explicated. The performance of the negative EL cooling is analyzed, both in the Shockley-Queisser (blackbody spectrum and radiative recombination) framework and the near-field enhancement. The “impedance match” condition derived for PV systems is applied to the negative EL devices. One advantageous feature of the negative EL cooling is that it does not apply the voltage to the target object which we want to cool, and the near-field enhancement can apply to various target materials that support the surface resonant modes. [ABSTRACT FROM AUTHOR]

Thermoradiative (TR) technology was recently proposed as a new mechanism to efficiently convert low-temperature waste heat into electric energy. It has been shown that near-field coupling between a TR cell and a heat sink is an effective way in boosting the performance of the TR device. The enhancement becomes more significant when surface resonant modes are supported by the heat sink. Surface plasmon polaritons on metal surfaces, and surface phonon polaritons on Lorentz materials, are two major types of materials investigated in the near-field enhancement. However, to significantly boost the performance, the resonant mode energy needs to match the bandgap energy of the TR cell, which is often difficult to realize with natural material selections. Typical metals have plasma frequency much higher than the bandgap of TR cell. In this paper, we show that new resonant modes with energy close to the bandgap of TR cell can be created with nanostructured gratings on the heat sink. This enables use to build the heat sink using commonly available metallic materials, whose typical surface resonant frequency is much higher than the TR bandgap. [ABSTRACT FROM AUTHOR]

Metal-free and metal-based electrocatalysts are designed according to different principles, but there should be an intimate connection between them. In this work, a simple yet cost-effective strategy is proposed to etch and disperse graphene oxide (GO) and porous hollow carbon shell loaded with CoS 2 (PHCS-CoS 2) into a porous skeleton similar to "highway" to effectively "trap" graphene oxide quantum dots (GOQDs) via a one-step process. Due to interconnected networks and size effects, N-S codoped porous graphene carbon sheets along with GOQDs (N,S-PGCS(QDs)) have eminent properties for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Furthermore, the metal-free system can be transformed to a metal-based electrocatalyst (N,S-PGCS(QDs)-Co 1-x S/Co 9 S 8) loaded with Co 1-x S/Co 9 S 8 nanohybrids, which demonstrates superior electrocatalytic characteristics than Pt/C+RuO 2 in terms of half-wave potential (0.85 V), current density, methanol tolerance, the potential difference between E ORR1/2 and E OER10 (0.68 V), and long-term stability. The Zn-air battery assembled with N,S-PGCS(QDs)-Co 1-x S/Co 9 S 8 shows a large peak power density of 168.2 mW cm−2, a capacity performance up to 817.9 mAh g−1, an ultra-high specific energy density of 973.3 Wh kg Zn −1 and considerable durability. The findings above may provide a scalable synthetic guidance and a novel direction for the design of metal-free and metal-based electrocatalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

As a promising catalyst for solar hydrogen production, black phosphorus (BP) has received widespread attention due to variable band gaps, high carrier mobility, and strong light absorption performance. Herein, we use MoS 2 as a cocatalyst to synthesize BP/MoS 2 catalyst with polycrystalline BP to improve photocatalytic performance under visible light irradiation. A small amount of MoS 2 can reduce the recombination of electron-hole pairs in the composite, increase carrier transport efficiency, and then improve photocatalytic performance. As expected, the 10/0.5 ratio of BP/MoS 2 catalyst exhibits the highest photocatalytic hydrogen evolution performance with a hydrogen evolution rate of 575.4 μmol h−1 g−1, which is 2.5 times of pure BP. Based on the results above, a simple method is provided to synthesize low-cost black phosphorus-based photocatalysts. Image 1 • A simple hydrothermal decomposition method was used to synthesize BP. • BP and MoS 2 are attracted by Van der Waals force to form a heterojunction. • The BP/MoS 2 heterostructure boosts photocatalytic H 2 evolution. [ABSTRACT FROM AUTHOR]

Abstract With the development of earth remote sensing technology, it is required to obtain high resolution and wide swath simultaneously. Synthetic Aperture Ladar(SAL) can achieve high-resolution images, but swath of images is limited. The multi-channel SAL combined with digital beamforming(DBF) technology provides a good solution to solve the problem. However, phase error between channels will degrade the quality of DBF. SAL is sensitive to phase error because of short wavelength of laser, which is at least three orders of magnitude shorter than that of synthetic aperture radar (SAR). Therefore, the conventional compensation methods can not satisfy the requirement of high compensation accuracy. In this paper, a compensation method based on antenna pattern and Doppler correlation coefficient is proposed, constructing a cost function. By minimizing the combined cost function, the phase error between channels is estimated with a good accuracy better than 1°. And simulation results validate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

A new combustion system has been applied to a 300 MW e down-fired boiler with swirl burners to reduce NO x emissions. The unit provided the introduction of overfire air (OFA) and a decrease in the flow area of the inner and outer secondary air ducts of the swirl burners. Industrial experiments on the retrofitted boiler were performed at different loads. Full-scale measurements of the flue gas temperature distribution in the burner outlet region, the furnace temperature distributions measured by a pyrometer and the local mean gas species concentrations in the region near the sidewall were made at loads of 180, 250, and 300 MW e . The results show that the ignition distance increased with decreasing load, especially as the load decreased from 250 MW e to 180 MW e . At three different loads, the retrofitted coal/air flow could be all ignited in time at a distance in the range of 0.6–1.4 m from the burner outlet. Compared with the original combustion system, the ignition distance of the coal/air flow was significantly reduced at a load of 300 MW e . In addition, at a load of 300 MW e , the temperature of the boiler hopper was much higher than that at loads of 180 MW e and 250 MW e . Compared with the original combustion system, the upper furnace temperature decreased slowly with increasing measurement height at a load of 300 MW e after the retrofit. Measurements of the O 2 and CO concentrations in the region near the sidewall indicate that the fullness degree of the coal flame in the furnace at different loads was different. After the retrofit, the reheat steam temperatures reached the design temperature of 541 °C at loads of 180 MW e and 250 MW e , and the average reheat steam temperatures increased by approximately 13 °C. Compared with the original combustion system, a significant NO x reduction (more than 40%) at different loads was achieved without increasing the levels of unburnt carbon in the fly ash. [ABSTRACT FROM AUTHOR]

Polarimetric synthetic aperture radar (SAR) is an effective technique to retrieve physical properties of planetary surfaces, such as the dielectric constant and surface roughness. Dielectric properties of lunar regolith are quite attractive for future lunar SAR missions. In this paper, we investigate the dielectric properties of lunar regolith by the Mini-RF SAR data. First, a new model of dielectric constant inversion for hybrid polarimetric SAR is proposed, in which the hybrid polarimetric scattering similarity parameter is first introduced. Second, the dielectric constants of Apollo 14, 16, 17 and Chang'E-5 landing sites are estimated through the proposed model. The inversion results fit well with the laboratory measurements of lunar samples, with an estimated root mean square error (RMSE) of 0.53. In addition, we analyze the dielectric properties of regolith on crater floors in different geologic settings, including the lunar maria, highlands, and permanently shadowed regions (PSRs) near the lunar poles. The results indicate that for craters with diameters of 5–25 km, the real part of the dielectric constant of regolith fines increases with crater depth-to-diameter (d/D) ratio, while no apparent correlation is found with crater diameter. Furthermore, the average dielectric constant of regolith fines is 3.01 in PSRs, which is less than that in the lunar maria and highlands (3.43 and 4.13, respectively). This implies that craters in PSRs may possess a looser regolith material compared to the mid-latitude craters. In a word, the proposed method is useful for estimating the dielectric properties of lunar regolith, and it is promising for future lunar SAR applications. [ABSTRACT FROM AUTHOR]

• Double-layer cloud detection method for visible cloud image is proposed. • Double-layered clouds usually have different brightness, serving as the basis for detecting their shape. • The cloud base height serves as the basis for double-layered cloud judgment. • This method achieves an accuracy of 98.3% and 80.5% under non-overlapping and overlapping double-layer cloud conditions, respectively. Double-layer cloud is a special cloud condition, and clouds in two layers have different effects on solar radiation reaching ground. Getting the shape of double-layer clouds is helpful to study the change of solar irradiance. The proposed double-layer clouds detection method is based on the cloud base height (CBH) and brightness of double-layer clouds. The CBH is calculated based on binocular parallax, which requires two images filmed synchronously by two cameras, and the brightness is offered by the brightness channel in HSV color space. The accuracy of this method is 98.5% for single-layer clouds and 89.4% for double-layer clouds. The reasons for misidentifications are (1) the brightness contrast decreases when the high-layer clouds are thick, (2) the distant low clouds have different brightness in top and bottom. [ABSTRACT FROM AUTHOR]

In the presence of polyethylene glycol (PEG), we first investigate a facile hydrothermal process to fabricate CdMoO 4 :Tb 3+ green phosphor. The morphology and size of the products can be controlled by simply tuning the PEG amounts and the reaction time. The XRD results show that the CdMoO 4 :Tb 3+ can be indexed to CdMoO 4 phase. FE-SEM results revealed that the pure CdMoO 4 was a sphere with a diameter of about 2.6 μm. The photoluminescence (PL) properties of CdMoO 4 :Tb 3+ phosphors indicated energy transfer from MoO 4 2 - groups to Tb 3+ . PL spectra indicated the phosphors emitted green light centered at 544 nm under ultraviolet excitation. Simultaneously, this novel and efficient pathway could open new opportunities for further investigating about the properties of molybdate materials. [ABSTRACT FROM AUTHOR]

• A new strategy of supported cocatalyst was proposed to improve the practicability. • A novel and efficient method for preparing BP polycrystals is advanced. • Photocarriers were attracted by cocatalyst to develop hydrogen evolution efficiency. • Degradation of BP was effectively prevented via loading TiF 3 and F- protective layer. As a cocatalyst, TiF 3 was prepared via fluorination and reduction of TiO 2 , and was loaded on BP polycrystalline nanosheets by one step hydrothermal method. TiF 3 -BP as a catalyst showed excellent photocatalytic activity, and the photocatalytic hydrogen production rate reached 612 μmolh−1 g−1 after UV–vis irradiation for 4 h. On the basis of the spectroscopic and morphological characteristics, the enhanced photocatalytic activity of H 2 was mainly attributed to the formation of BP polycrystal structure, similar to the heterojunction. And TiF 3 cocatalyst absorbed surface charges, changed energy band positions, and accelerated electron transfer, leading to the development of the electron reduction ability. [Display omitted] Black phosphorus (BP) is a promising two-dimensional material with excellent carrier mobility and high co-catalytic activity for hydrogen generation. Herein, we use polycrystalline BP nanosheets as a photocatalyst and a structure of TiF 3 as a cocatalyst to produce hydrogen under ultraviolet-visible (UV–vis) light irradiation. The TiF 3 -BP composite demonstrates a hydrogen evolution rate of 612 μmolh−1 g−1 and nearly perfect cyclic stability during 4 h irradiation. The evolution rate is about 1.7 times higher than those of pure BP and TiO 2 and 1.5 times than that of commercial P25-BP mixture. In comparison with pure BP nanosheets, the addition of TiF 3 can effectively tailor the energy levels of BP nanosheets, decrease the recombination of photogenerated electron-hole pairs, facilitate carrier transports, and improve the stability of BP exposed to water and air. Therefore, the above findings provide a new approach for designing stable and high efficiency BP composite photocatalysts for hydrogen production. [ABSTRACT FROM AUTHOR]