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Unraveling atomic‐level active sites of layered photocatalyst towards low‐concentration CO2 conversion is still challenging. Herein, the yield and selectivity of photocatalytic CO2 reduction of the Aurivillius‐related oxide semiconductor Bi2O2SiO3 nanosheet (BOSO) were largely improved using a surface sulfidation strategy. The experiment and theoretical calculation confirmed that surface sulfidation of the Bi2O2SiO3 nanosheet (S‐BOSO, 6.28 nm) redistributed the charge‐enriched Bi sites, extended the solar spectrum absorption to the whole visible range, and considerably enhanced the charge separation, in addition to creating new reaction active sites, as compared to pristine BOSO. Subsequently, surface sulfidation played a switchable role, wherein S‐BOSO showed a very high CH3OH generation rate (12.78 µmol g−1 for 4 h, 78.6% selectivity) from low‐concentration CO2 (1000 ppm) under visible light irradiation, which outperforms most of the state‐of‐the‐art photocatalysts under similar conditions. This study presents an atomic‐level modification protocol for engineering reactive sites and charge behaviors to promote solar‐to‐energy conversion. A desirable atomic‐level sulfidation strategy over an Aurivillius‐related layer‐structured photocatalyst Bi2O2SiO3 is demonstrated. Sulfidation‐induced reactive sites facilitate local charge separation, contributing to enhanced low‐concentration CO2 photoreduction. The system also shows feasibility in diluted CO2 conditions, typically hindered by the deficient reactive sites in conventional systems.

A vehicle’s solenoid valve-actuated shock (SVSA) absorber is of wide interest because of its adjustable damping characteristics. The proportional solenoid valve is a pivotal component for commanding damping force, but the research on its model principle still needs to be improved. Therefore, this research aimed to establish an accurate model of the proportional solenoid valve composed of the pilot valve and relief valve. In the pilot valve, we proposed a valve spool structure using a two-stage combined throttling groove to control flow accurately. Then, the dynamic equation of the spool was established, and it is also considered that the magnetic saturation of soft magnetic materials impacts electromagnetic force. The flow force in the dynamic equation was numerically solved by the CFD method. The flow rate in the relief valve was analyzed from the deformation of the lamination valves and main valve plate through the small deflections thin plate theory. Then, the SVSA bench test was carried out. The results show good agreement between the test and calculation, and the maximum error is within 9 %. It is indicated that the model of the SVSA equipped with the proportional solenoid valve has high accuracy.

Background The production of secondary metabolites with antibiotic properties is a common characteristic to entomopathogenic bacteria Xenorhabdus spp. These metabolites not only have diverse chemical structures but also have a wide range of bioactivities with medicinal and agricultural interests such as antibiotic, antimycotic and insecticidal, nematicidal and antiulcer, antineoplastic and antiviral. It has been known that cultivation parameters are critical to the secondary metabolites produced by microorganisms. Even small changes in the culture medium may not only impact the quantity of certain compounds but also the general metabolic profile of microorganisms. Manipulating nutritional or environmental factors can promote the biosynthesis of secondary metabolites and thus facilitate the discovery of new natural products. This work was conducted to evaluate the influence of nutrition on the antibiotic production of X. bovienii YL002 and to optimize the medium to maximize its antibiotic production. Results Nutrition has high influence on the antibiotic production of X. bovienii YL002. Glycerol and soytone were identified as the best carbon and nitrogen sources that significantly affected the antibiotic production using one-factor-at-a-time approach. Response surface methodology (RSM) was applied to optimize the medium constituents (glycerol, soytone and minerals) for the antibiotic production of X. bovienii YL002. Higher antibiotic activity (337.5 U/mL) was obtained after optimization. The optimal levels of medium components were (g/L): glycerol 6.90, soytone 25.17, MgSO 4 ·7H 2 O 1.57, (NH 4 ) 2 SO 4 2.55, KH 2 PO 4 0.87, K 2 HPO 4 1.11 and Na 2 SO 4 1.81. An overall of 37.8% increase in the antibiotic activity of X. bovienii YL002 was obtained compared with that of the original medium. Conclusions To the best of our knowledge, there are no reports on antibiotic production of X. boviebii by medium optimization using RSM. The results strongly support the use of RSM for medium optimization. The optimized medium not only resulted in a 37.8% increase of antibiotic activity, but also reduced the numbers of experiments. The chosen method of medium optimization was efficient, simple and less time consuming. This work will be useful for the development of X. bovienii cultivation process for efficient antibiotic production on a large scale, and for the development of more advanced control strategies on plant diseases.

Background Hemodialysis is the most common treatment of end-stage renal disease. However, it is associated with a range of symptoms affecting patients’ daily activities and quality of life. Effective self-management has proven crucial for the alleviation of symptoms. According to Social Cognitive Theory, social capital and patient empowerment may be important variables for predicting self-management. To date, few studies have explored the mechanisms underlying these results. The study aimed to verify whether patient empowerment mediated the effect of social capital on the self-management of hemodialysis patients. Methods The study was performed with 245 hemodialysis patients from January 2021 to April 2021 in Taiyuan, China. Demographic and clinical characteristics, social capital, patient empowerment, and self-management of patients undergoing hemodialysis were measured with a self-reported questionnaire. Descriptive statistics were used to summarize the participants’ demographic and clinical characteristics, and bootstrapping tests were used to verify whether patient empowerment mediated the association of social capital with self-management in patients undergoing hemodialysis. Results Mediation analysis indicated that social capital and patient empowerment significantly predicted self-management. Patient empowerment partially mediated the relationship between social capital and self-management in hemodialysis patients. Conclusions The results suggest that hemodialysis patients show relatively poor self-management and that patient empowerment mediates both social capital and self-management. Strategies to mobilize patients’ social networks and help them identify and utilize effective social resources may provide useful information regarding the implementation of optimal health management for their disease.

In this paper, the parameter optimization and error analysis of the rack and pinion steering mechanism are carried out on the basis of considering the influence of kingpin parameters. The steering characteristic equation describing the motion of the steering mechanism is calculated by analyzing the spatial geometrical relationship between the wheel and kingpin and unifying the projection relation between the kingpin and the equivalent steering trapezoid. The ideal Ackermann equation is modified by the Ackermann rate and the kingpin parameters. The modified Ackermann equation is used as the objective function. The segmented fitness function and the evaluation function with weighted factors are designed. A genetic algorithm containing the three functions is used to optimize the parameters of the steering characteristic equation. The error analysis of the numerical example shows that the accuracy of steering trapezoid structure parameters, steering characteristic equation, and Ackermann equation is improved compared with that before optimization.

The unique structure and physical properties of perovskite-type catalysts make them highly promising for catalyzing efficient coal combustion. Mesoporous perovskite LaNixFe1−xO3 (x = 0.2, 0.4, 0.6, 0.8) coal combustion catalysts were synthesized using the sol–gel method. The effects of the doping amount of B-site doped nickel on both the crystal structure and catalytic performance were investigated. X-ray diffraction, scanning electron microscopy, and nitrogen adsorption–desorption tests were used to characterize the catalyst samples. Thermogravimetric analysis (TG) and activation energy (Ea) calculations were used to assess the catalyst’s activity for the catalytic combustion of anthracite coal (JF coal, originating from Shanxi, China). Results revealed that nickel doping created lattice distortion and Ni-Fe alloy interactions. The difference in nickel doping significantly affects the morphology and catalytic activity of perovskite. The addition of LaNi0.6Fe0.4O3 (NI6) with a mass fraction of 5% resulted in the highest average burning rate value (va = 4.52%/min) of JF coal among all synthesized catalysts. The Ea of JF coal catalytic combustion, calculated using the Coats–Redfern method and the Doyle method, showed a good agreement with the TG curves. The LaNixFe1-xO3 series catalysts were found to significantly decrease the Ea of JF coal combustion, with a maximum reduction of 42% compared to the case without any catalyst added. Among the synthesized catalysts, NI6 exhibited a favorable catalytic combustion performance and is thus a promising candidate for the clean and efficient utilization of coal resources.

Upon exposure to exogenous pediocin-like bacteriocins, immunity proteins specifically bind to the target receptor of the mannose phosphotransferase system components (man-PTS IIC and IID), therefore preventing bacterial cell death. However, the specific recognition of immunity proteins and its associated target receptors remains poorly understood. In this study, we constructed hybrid receptors to identify the domains of IIC and/or IID recognized by the immunity protein PedB, which confers immunity to pediocin PA-1. Using Lactobacillus plantarum man-PTS EII mutant W903, the IICD components of four pediocin PA-1-sensitive strains (L. plantarum WQ0815, Leuconostoc mesenteroides 05-43, Lactobacillus salivarius REN and Lactobacillus acidophilus 05-172) were respectively co-expressed with the immunity protein PedB. Well-diffusions assays showed that only the complex formed by LpIICD from L. plantarum WQ0815 with pediocin PA-1 could be recognized by PedB. In addition, a two-step PCR approach was used to construct hybrid receptors by combining LpIIC or LpIID recognized by PedB with the other three heterologous IID or IIC compounds unrecognized by PedB, respectively. The results showed that all six hybrid receptors were recognized by pediocin PA-1. However, when IIC or IID of L. plantarum WQ0815 was replaced with any corresponding IIC or IID component from L. mesenteroides 05-43, L. salivarius REN and L. acidophilus 05-172, all the hybrid receptors could not be recognized by PedB. Taken altogether, we concluded that both IIC and IID components of the mannose phosphotransferase system play an important role in the specific recognition between the bacteriocin-receptor complex and the immunity protein PedB.

Smeared spectrum (SMSP) jamming is a deceptive jamming technique commonly used against linear frequency modulation (LFM) radar. This technique produces high-density false targets that resemble a comb shape after pulse compression processing, resulting in both deceiving and suppressing effects. In order to suppress jamming effectively, a new antijamming technique has been proposed that combines Lv’s distribution (LVD) with biorthogonal Fourier transform (BFT). The main idea of this antijamming method is based on a three-step process: “parameter estimation—echo modulation—identification and suppression.” The first step involves obtaining the delay and chirp rate of the jamming from the LVD matrix of the radar echo. Based on the estimated parameter information, a reference signal is designed to modulate the jamming into a complete chirp signal. In the second step, biorthogonal Fourier transform is used to distinguish between the target’s echo and jamming based on the difference in the chirp rate. Finally, jamming is filtered using narrow-band filtering in the chirp rate domain, and the original echo is recovered by using biorthogonal inverse Fourier transform (IBFT). Simulation results demonstrate that the proposed method achieves high accuracy in estimating jamming parameters and is capable of suppressing false targets under high jamming-to-signal ratio (JSR) conditions.

• The leaf carbon isotope ratio (δ¹³C) of C₃ plants is inversely related to the drawdown of CO₂ concentration during photosynthesis, which increases towards drier environments. We aimed to discriminate between the hypothesis of universal scaling, which predicts between-species responses of δ¹³C to aridity similar to within-species responses, and biotic homoeostasis, which predicts offsets in the δ¹³C of species occupying adjacent ranges. • The Northeast China Transect spans 130-900 mm annual precipitation within a narrow latitude and temperature range. Leaves of 171 species were sampled at 33 sites along the transect (18 at ≥ 5 sites) for dry matter, carbon (C) and nitrogen (N) content, specific leaf area (SLA) and δ¹³C. • The δ¹³C of species generally followed a common relationship with the climatic moisture index (MI). Offsets between adjacent species were not observed. Trees and forbs diverged slightly at high MI. In C₃ plants, δ¹³C predicted N per unit leaf area (Narea) better than MI. The δ¹³C of C₄ plants was invariant with MI. SLA declined and Narea increased towards low MI in both C₃ and C₄ plants. • The data are consistent with optimal stomatal regulation with respect to atmospheric dryness. They provide evidence for universal scaling of CO₂ drawdown with aridity in C₃ plants.

Glycosyltransferases are key enzymes involved in the assembly of repeating units of exopolysaccharides (EPS). A glycosyltransferase generally consists of the N-terminal and the C-terminal domain, however, the functional role of these domains in EPS biosynthesis remains largely unknown. In this study, homologous overexpression was employed to investigate the effects of EpsF N , a truncated form of rhamnosyltransferase EpsF with only the N-terminal domain, on EPS biosynthesis in Streptococcus thermophilus 05-34. Reverse transcription qPCR and Western blotting analysis confirmed the successful expression of epsF N in 05-34 at the transcription and translation level, respectively. Further analysis showed that the monosaccharide composition and yield of EPS were not affected by the overexpression of epsF N , whereas the molecular mass decreased by 5-fold. Accordingly, the transcription levels of genes involved in EPS biosynthesis, including chain-length determination gene epsC , were down-regulated by 5- to 6-fold. These results indicated that the N-terminal domain of EpsF alone could influence the molecular mass of EPS, probably via lowering the concentration of sugar precursors, which may lead to decreased expression of genes responsible for chain-length determination.