Explore the vast range of titles available.

Due to the increasing demand for eco-friendly, cost-effective and safe technologies, biosynthetic metal nanoparticles have attracted worldwide attention. In this study, silver nanoparticles (AgNPs) were extracellularly biosynthesized using the culture supernatants of Aspergillus sydowii . During synthesis, color change was preliminarily judge of the generation of AgNPs, and the UV absorption peak at 420 nm further confirms the production of AgNPs. Transmission electron microscopy and X-ray diffraction were also used to identify the AgNPs. The results shows that AgNPs has crystalline cubic feature and is a polydisperse spherical particle with size between 1 and 24 nm. Three main synthesis factors (temperature, pH and substrate concentration) were optimized, the best synthesis conditions were as follows 50 °C, 8.0 and 1.5 mM. In the biological application of AgNPs, it shows effective antifungal activity against many clinical pathogenic fungi and antiproliferative activity to HeLa cells and MCF-7 cells in vitro. Our research finds a new path to biosynthesis of AgNPs in an eco-friendly manner, and bring opportunity for biomedical applications in clinic.

Crystalline thermoelectrics have been developed to be potential candidates for power generation and electronic cooling, among which SnSe crystals are becoming the most representative. Herein, we realize high-performance SnSe crystals with promising efficiency through a structural modulation strategy. By alloying strontium at Sn sites, we modify the crystal structure and facilitate the multiband synglisis in p-type SnSe, favoring the optimization of interactive parameters μ and m * . Resultantly, we obtain a significantly enhanced PF ~85 μW cm −1 K −2 , with an ultrahigh ZT ~1.4 at 300 K and ZT ave ~2.0 among 300–673 K. Moreover, the excellent properties lead to single-leg device efficiency of ~8.9% under a temperature difference ΔT ~300 K, showing superiority among the current low- to mid-temperature thermoelectrics, with an enhanced cooling Δ T max of ~50.4 K in the 7-pair thermoelectric device. Our study further advances p-type SnSe crystals for practical waste heat recovery and electronic cooling. Thermoelectric technology directly enables both power generation and electronic cooling. Here, the authors realize high-performance SnSe crystals with promising device efficiencies by modulating crystal and band structures.

The objective of this study was to find one or more fungal strains that could be utilized to biosynthesize antifungal silver nanoparticles (AgNPs). Using morphological and molecular methods, Arthroderma fulvum was identified as the most effective fungal strain for synthesizing AgNPs. The UV-visible range showed a single peak at 420 nm, which corresponded to the surface plasmon absorbance of AgNPs. X-ray diffraction and transmission electron microscopy demonstrated that the biosynthesized AgNPs were crystalline in nature with an average diameter of 15.5±2.5 nm. Numerous factors could potentially affect the process of biosynthesis, and the main factors are discussed here. Optimization results showed that substrate concentration of 1.5 mM, alkaline pH, reaction temperature of 55°C, and reaction time of 10 hours were the optimum conditions for AgNP biosynthesis. Biosynthesized AgNPs showed considerable activity against the tested fungal strains, including Candida spp., Aspergillus spp., and Fusarium spp., especially Candida spp.

Highly regio-, diastereo- and enantioselective iron-catalyzed sequential hydrosilylation of o -alk- n -enyl-phenyl silanes with alkynes is reported for various 5-, 6-, and 7-membered benzosilacycles in 60-94% yields with up to 95:5 rr , 95:5 dr , and 99% ee . Chiral fully carbon-substituted silicon-stereogenic benzosilacycles could also be obtained via triple hydrosilylation reactions. The unique electronic effect of ligands is observed while adjusting the regioselectivity and enantioselectivity in hydrosilylation reactions. A possible mechanism has been proposed by variable time normalization analysis (VTNA) and H/D exchange experiment. Benzosilacycles are of potential interest in drug discovery and materials science, and they are often synthesized through transition-metal cyclizations. Here, the authors report iron-catalyzed sequential hydrosilylations of alkynes to access various 5-, 6-, 7- and 10-membered benzosilacycles in high yield and selectivity.

High power vacuum electronic devices of millimeter wave to terahertz regime are attracting extensive interests due to their potential applications in science and technologies. In this paper, the design and experimental results of a powerful compact oversized surface wave oscillator (SWO) in Y-band are presented. The cylindrical slow wave structure (SWS) with rectangular corrugations and large diameter about 6.8 times the radiation wavelength is proposed to support the surface wave interacting with annular relativistic electron beam. By choosing appropriate beam parameters, the beam-wave interaction takes place near the π-point of TM 01 mode dispersion curve, giving high coupling impedance and temporal growth rate compared with higher TM 0 n modes. The fundamental mode operation of the device is verified by the particle-in-cell (PIC) simulation results, which also indicate its capability of tens of megawatts power output in the Y-band. Finally, a compact experimental setup is completed to validate our design. Measurement results show that a terahertz pulse with frequency in the range of 0.319–0.349 THz, duration of about 2 ns and radiation power of about 2.1 MW has been generated.

Thermoelectric generators enable the conversion of waste heat to electricity, which is an effective way to alleviate the global energy crisis. However, the inefficiency of thermoelectric materials is the main obstacle for realizing their widespread applications and thus developing materials with high thermoelectric performance is urgent. Here we show that multiple valence bands and strong phonon scattering can be realized simultaneously in p-type PbSe through the incorporation of AgInSe 2 . The multiple valleys enable large weighted mobility, indicating enhanced electrical properties. Abundant nano-scale precipitates and dislocations result in strong phonon scattering and thus ultralow lattice thermal conductivity. Consequently, we achieve an exceptional ZT of ~ 1.9 at 873 K in p-type PbSe. This work demonstrates that a combination of band manipulation and microstructure engineering can be realized by tuning the composition, which is expected to be a general strategy for improving the thermoelectric performance in bulk materials. Power generation from heat to electricity can be realized by thermoelectric materials. Here, the authors improve the thermoelectric properties in PbSe enabled by multiple bands convergence and strong phonon scattering.

Great progress has been achieved in p-type SnS thermoelectric compound recently, while the stagnation of the n-type counterpart hinders the construction of thermoelectric devices. Herein, n-type sulfide PbSnS 2 with isostructural to SnS is obtained through Pb alloying and achieves a maximum ZT of ~1.2 and an average ZT of ~0.75 within 300–773 K, which originates from enhanced power factor and intrinsically ultralow thermal conductivity. Combining the optimized carrier concentration by Cl doping and enlarged Seebeck coefficient through activating multiple conduction bands evolutions with temperature, favorable power factors are maintained. Besides, the electron doping stabilizes the phase of PbSnS 2 and the complex-crystal-structure induced strong anharmonicity results in ultralow lattice thermal conductivity. Moreover, a maximum power generation efficiency of ~2.7% can be acquired in a single-leg device. Our study develops a n-type sulfide PbSnS 2 with high performance, which is a potential candidate to match the excellent p-type SnS. Direct and reversible conversion between heat and electricity can be achieved in thermoelectric materials. Here, the authors realize high thermoelectric performance in PbSnS 2 crystals enabled by multiple bands convergence.

Elastic band resistance training in elderly individuals can improve physical fitness and promote mental health in addition to other benefits. This systematic review aimed to review, summarize, and evaluate quantitative, qualitative, and mixed methodological studies on the use of elastic band resistance training in elderly individuals, and to investigate the influence of elastic band resistance training on the physical and mental health of elderly individuals, as well as their preferences and obstacles in training. A convergent separation approach was used to synthesize and integrate the results, specifically the mixed systematic review approach recommended by the Joanna Briggs Institute. The extensive search strategy included electronic database searches in the Cochrane Library, PubMed, Embase, Web of Science, Google Scholar, MEDLINE, and CINAHL. The researchers rigorously screened the literature, extracted and analyzed the data, and evaluated the quality of the included studies using the Mixed Methods Appraisal Tool (MMAT). Twenty-eight studies were included, of which 25 were quantitative studies, 2 were qualitative studies, and 1 was a mixed-methods study. A total of 1,697 subjects were investigated across all studies. Quantitative evidence supports the notion that elastic band resistance training can improve upper and lower limb flexibility, endurance, upper strength, physical balance, and cardiopulmonary function and enhance the mental health of elderly individuals. Participants in the qualitative study reported some preferences and obstacles with band resistance training, but most participants reported physical benefits. Despite the heterogeneity between studies, this review is the first systematic review to comprehensively evaluate the effectiveness of elastic band resistance training in older adults. It not only shows the influence of elastic band resistance training on the physical and mental health of the elderly, but also emphasizes the preference and obstacles of elderly individuals face.

Sub-stoichiometric MoO 3− x nanostructures with plasmonic absorption via creating oxygen vacancies have attracted extensive attentions for many intriguing applications. However, the synthesis of one-dimensional (1D) plasmonic MoO 3− x nanostructures with widely tunable plasmonic absorption has remained a significant challenge because of their serious morphological destruction and phase change with increasing the concentration of oxygen vacancies. Here we demonstrate a surface-ligand protected reduction strategy for the synthesis of 1D MoO 3− x nanobelts with tunable plasmonic absorption in a wide wavelength range from 200 to 2,500 nm. Polyethylene glycol (PEG-400) is used as both the reductant to produce oxygen vacancies and the surface protected ligands to maintain 1D morphology during the formation process of MoO 3− x nanobelts, enabling the widely tunable plasmonic absorption. Owing to their broad plasmonic absorption and unique 1D nanostructure, we further demonstrate the application of 1D MoO 3− x nanobelts as photothermal film for interfacial solar evaporator. The surface-ligand protected reduction strategy provides a new avenue for the developing plasmonic semiconductor oxides with maintained particle morphology and thus enriching their wide applications.

The frequent bending of shearer cables during operation often leads to mechanical fatigue, posing risks to equipment safety. Accurately predicting the mechanical properties of these cables under bending conditions is crucial for improving the reliability and service life of shearers. This paper proposes a shearer optical fiber cable mechanical characteristics prediction model based on Temporal Convolutional Network (TCN), Bidirectional Long Short-Term Memory (BiLSTM), and Squeeze-and-Excitation Attention (SEAttention), referred to as the TCN-BiLSTM-SEAttention model. This method leverages TCN’s causal and dilated convolution operations to capture long-term sequential features, BiLSTM’s bidirectional information processing to ensure the completeness of sequence information, and the SEAttention mechanism to assign adaptive weights to features, effectively enhancing the focus on key features. The model’s performance is validated through comparisons with multiple other models, and the contributions of input features to the model’s predictions are quantified using Shapley Additive Explanations (SHAP). By learning the stress variation patterns between the optical fiber, power conductor, and control conductor in the shearer cable, the model enables accurate prediction of the stress in other cable conductors based on optical fiber stress data. Experiments were conducted using a shearer optical fiber cable bending simulation dataset with traction speeds of 6 m/min, 8 m/min, and 10 m/min. The results show that, compared to other predictive models, the proposed model achieves reductions in Mean Squared Error (MSE), Root Mean Squared Error (RMSE), and Mean Absolute Error (MAE) to 0.0002, 0.0159, and 0.0126, respectively, with the coefficient of determination (R 2 ) increasing to 0.981. The maximum deviation between predicted and actual values is only 0.86%, demonstrating outstanding prediction accuracy. SHAP feature analysis reveals that the control conductor features have the most substantial influence on predictions, with a SHAP value of 0.095. The research shows that the TCN-BiLSTM-SEAttention model demonstrates outstanding predictive capability under complex operating conditions, providing a novel approach for improving cable management and equipment safety through optical fiber monitoring technology in the intelligent development of coal mines, highlighting the potential of deep learning in complex mechanical predictions.