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Purpose – This study aims to investigate the cause of high-order wheel polygonization in a plateau high-speed electric multiple unit (EMU) train. Design/methodology/approach – A series of field tests were conducted to measure the vibration accelerations of the axle box and bogie when the wheels of the EMU train passed through tracks with normal rail roughness after re-profiling. Additionally, the dynamic characteristics of the track, wheelset and bogie were also measured. These measurements provided insights into the mechanisms that lead to wheel polygonization. Findings – The results of the field tests indicate that wheel polygonal wear in the EMU train primarily exhibits 14–16 and 25–27 harmonic orders. The passing frequencies of wheel polygonization were approximately 283–323 Hz and 505–545 Hz, which closely match the dominated frequencies of axle box and bogie vibrations. These findings suggest that the fixed-frequency vibrations originate from the natural modes of the wheelset and bogie, which can be excited by wheel/rail irregularities. Originality/value – The study provides novel insights into the mechanisms of high-order wheel polygonization in plateau high-speed EMU trains. Futher, the results indicate that operating the EMU train on mixed lines at variable speeds could potentially mitigate high-order polygonal wear, providing practical value for improving the safety, performance and maintenance efficiency of high-speed EMU trains.

Highlights The acid etching Co-naphthalenedicarboxylic acid-based metal–organic frameworks (donated as AE-CoNDA) catalyst displayed an excellent oxygen evolution reaction (OER) activity for long-term stability. Integration of the AE-CoNDA cocatalyst into BiVO4 achieved a remarkable PEC-OER activity. The stretched Co-O bond length regulated the spin state transition at the Co active sites. The optimized high spin state of Co sites adjusted the orbitals hybridization of Co 3d and O 2p.

IntroductionThe influence of excess weight on the development of children's feet remains a subject of debate. To further elucidate whether this relation occurs, this study compared arch morphology and flexibility in three groups of children: underweight, normal, and overweight.MethodsIn total, 1,532 children (807 boys, 725 girls; age range 7–11 years) participated in the study. The researchers measured the participants’ height and weight, calculated their body mass index, and categorized their weight status as underweight, normal weight, or overweight. A three-dimensional foot model was taken using a three-dimensional plantar scanner under non-weight-bearing and weight-bearing conditions to obtain arch morphometric indices (arch index and arch volume) and arch flexibility index (arch volume index).ResultsAnalysis of the data showed that the arch index was higher in overweight children compared to underweight and normal weight children (p 0.05). All children were divided into flatfoot, normal, and pes cavus groups according to arch index, and the arch volume index was statistically significant (p

Abstract Objective The aim of this study was to assess the accuracy and test-retest reliability of a wearable inertial measurement unit (IMU) system for gait analysis in healthy female compared to a gold-standard optoelectronic motion capture (OMC) system. Methods In our study, we collected data from 5 healthy young females. Participants were attached with markers from both the OMC system and the IMU system simultaneously. Data was collected when participants walked on a 7 m walking path. Each participant performed 50 repetitions of walking on the path. To ensure the collection of complete gait cycle data, a gait cycle was considered valid only if the participant passed through the center of the walking path at the same time that the OMC system detected a valid marker signal. As a result, 5 gait cycles that met the standards of the OMC system were included in the final analysis. The stride length, cadence, velocity, stance phase and swing phase of the spatio-temporal parameters were included in the analysis. A generalized linear mixture model was used to assess the repeatability of the two systems. The Wilcoxon rank-sum test for continuous variables was used to compare the mean differences between the two systems. For evaluating the reliability of the IMU system, we calculated the Intra-class Correlation Coefficient (ICC). Additionally, Bland-Altman plots were used to compare the levels of agreement between the two systems. Results The measurements of Spatio-temporal parameters, including the stance phase (P = 0.78, 0.13, L-R), swing phase (P = 0.78, 0.13, L-R), velocity (P = 0.14, 0.13, L-R), cadence (P = 0.53, 0.22, L-R), stride length (P = 0.05, 0.19, L-R), by the IMU system and OMC system were similar. Which suggested that IMU and OMC systems could be used interchangeably for gait measurements. The intra-rater reliability showed an excellent correlation for the stance phase, swing phase, velocity and cadence (Intraclass Correlation Coefficient, ICC > 0.9) for both systems. However, the correlation of stride length was poor (ICC = 0.36, P = 0.34, L) to medium (ICC = 0.56, P = 0.22, R). Additionally, the measurements of IMU systems were repeatable. Conclusions The results of IMU system and OMC system shown good repeatability. Wearable IMU system could analyze gait data accurately. In particular, the measurement of stance phase, swing phase, velocity and cadence showed excellent reliability. IMU system provided an alternative measurement to OMC for gait analysis. However, the measurement of stride length by IMU needs further consideration.

Background: Thyroid Dysfunction (TD) is a common immune-related adverse events (irAEs) in the treatment of advanced lung cancer with programmed cell death protein 1 (PD-1) and programmed death 1 ligand (PD-L1) inhibitors, with incidence accounting for 6–8% of all irAEs. The incidence of TD is receiving increasing attention from clinicians, given its potential impact on clinical efficacy. However, the molecular mechanisms, biomarkers, and clinical impact of TD resulting from PD-1/PD-L1 inhibitor treatment in advanced lung cancer are unclear. Objective: To present a comprehensive review of current advancements in research about the molecular mechanisms, influential factors, and clinical manifestations in the treatment of advanced lung cancer with PD-1 and PD-L1 inhibitors, as well as the correlation between TD and the efficacy of PD-1 and PD-L1 inhibitors. Methods: A systematic search was conducted using PubMed, Web of Science, Cochrane Library, Embase and Google Scholar databases, with the keywords including thyroid dysfunction, efficacy, mechanisms, immune checkpoint inhibitors, PD-1/PD-L1 inhibitors, and advanced lung cancer. Results: PD-1/PD-L1 inhibitors can induce T cell-mediated destructive thyroiditis, thyroid autoantibody-mediated autoimmunity, and a decrease in the number of immunosuppressive monocytes (circulating cluster of differentiation (CD)14+ human leukocyte antigen (HLA)-DRlow/negatives monocytes, CD14+ HLA-DR + lo/neg), leading to TD. Several factors, including peripheral blood inflammatory markers, body mass index (BMI), baseline thyroid-stimulating hormone (TSH) level, gender, smoking history, hypertension, and previous opioid use, may also contribute to the development of TD. However, there is currently a lack of reliable predictive biomarkers for TD, although anti-thyroid antibodies, TSH levels, and peripheral blood inflammatory markers are expected to be predictive.Interestingly, some studies suggested a positive correlation between TD and clinical efficacy, i.e., patients experiencing TD showed better outcomes in objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS), compared with those without TD. However, most of these studies were single-center and had small sample sizes, so more multi-center studies are needed to provide further data support. Conclusion: TD resulting from PD-1/PD-L1 inhibitor treatment in advanced lung cancer may be associated with good clinical outcomes. The clarification of the molecular mechanisms underlying TD and the identification of reliable predictive biomarkers will guide clinicians in managing TD in this patient population.

Abstract Radar-based human activity recognition (HAR) offers a non-contact technique with privacy protection and lighting robustness for many advanced applications. Complex deep neural networks demonstrate significant performance advantages when classifying the radar micro-Doppler signals that have unique correspondences with human behavior. However, in embedded applications, the demand for lightweight and low latency poses challenges to the radar-based HAR network construction. In this paper, an efficient network based on a lightweight hybrid Vision Transformer (LH-ViT) is proposed to address the HAR accuracy and network lightweight simultaneously. This network combines the efficient convolution operations with the strength of the self-attention mechanism in ViT. Feature Pyramid architecture is applied for the multi-scale feature extraction for the micro-Doppler map. Feature enhancement is executed by the stacked Radar-ViT subsequently, in which the fold and unfold operations are added to lower the computational load of the attention mechanism. The convolution operator in the LH-ViT is replaced by the RES-SE block, an efficient structure that combines the residual learning framework with the Squeeze-and-Excitation network. Experiments based on two human activity datasets indicate our method’s advantages in terms of expressiveness and computing efficiency over traditional methods.

Abstract Electrocatalytic oxygen reduction reaction (ORR) to prepare H2O2 in acidic medium has the advantages of green, safety, and portability, which shows broad development prospects. However, it still suffers from low catalyst activity, insufficient selectivity, and high cost. Herein, Pt1/CoSe2 with ultralow 0.01 wt.% Pt atomic distribution was synthesized by a simple hydrothermal method. The Pt1/CoSe2 with ultralow Pt content exhibits high activity, high selectivity, and long‐term stability for ORR to H2O2 in O2‐saturated 0.1 M HClO4. The onset potential is as low as 0.75 V versus reversible hydrogen electrode (RHE), H2O2 selectivity is as high as 84% (0.4 V vs. RHE), and the electron transfer number is 2.3 (0.4 V vs. RHE). Moreover, the hydrogen peroxide yield using the flow cell testing is 110.02 mmol gcat.−1 h−1 with high Faradaic efficiency of 78% (0 V vs. RHE) at 0.1 M HClO4, and the catalyst did not deactivate significantly after 60 h stability testing. Mechanistic studies and in situ X‐ray photoelectron spectroscopy characterization confirm that the ultralow Pt content on CoSe2 can effectively regulate the electronic structure of Co as the real active site around the Pt site, which gives a suitable ∆dp value (the difference between the d‐band center of the active metal site and the p‐band center of the terminal oxygen in *OOH), provides an ideal *OOH binding energy, and inhibits the O–O bond breakage. This work successfully improves the intrinsic activity of the Co active sites around Pt in Pt1/CoSe2 for acidic ORR to H2O2 by constructing ultralow‐content Pt single atom.

Abstract The non‐noble Mn coordinated N, P co‐doping graphene materials were investigated theoretically in this work based on density functional theory calculation. The electronic structure is effectively tuned after the introduction of P heteroatom. The moderate d band center and density of states at Fermi energy of MnN4‐P1‐G indicate that it is of modest adsorption ability for these O‐containing intermediates. The rank of adsorption energies of O‐containing intermediates for MnN4‐P1‐G is OH* > 2OH* > OOH* > O* > O2* > H2O*, whereas the MnN4‐P1‐G favors a four‐electron process instead of two‐electron process. The doping of P on MnN4‐P1‐G can increase the kinetic activity for the rate‐determining step as well as the Ulim for MnN4‐P1‐G significantly increases from 0.38 to 0.45 V compared with MnN4‐G. The spin density and magnetic moments of Mn are effectively tuned by d, p hybridization to lower the adsorption energy of OH intermediates (rate‐determining step [RDS]) so as to improve the catalytic activity. It is concluded that the P‐doped MnN4 catalysts with excellent oxygen reduction reaction activity can be obtained and this study can provide theoretical guidance for the rational design of high‐performance Mn‐based carbon materials catalysts.

Abstract Atomically dispersed and nitrogen coordinated single metal site (MNx, M = Fe, Co, or Mn) moieties embedded in partially graphitized carbon (denoted as M–N–C) are recognized as the most promising platinum group metal‐free catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. However, simply regulating their coordination environments and local structures of single metal sites cannot fundamentally change active site structure, which leads to insufficient activity and stability. A second transition metal can be incorporated to design dual‐metal sites, offering a new opportunity to modulate the electronic and geometric structures of M–N–C catalysts. Therefore, exploring optimal atomically dispersed dual‐metal‐site is essential to designing new active sites with enhanced ORR activity, and stability, especially breaking the activity‐stability trade‐off. This review provides a comprehensive analysis of the advances in developing atomically dispersed dual‐metal site catalysts for the ORR, including innovative synthesis methods, primary structural configurations, and the mechanisms to promote catalytic performance. We aim to elucidate the crucial structure–property correlation, emphasizing the inherent electronic and geometric effects of dual metal sites. Finally, we discuss the current challenges of dual‐metal site catalysts concerning rational design, precise synthesis, and high‐fidelity structural characterization.

Objectives: This study aimed to determine the thresholds of serum concentration as a predictor of tigecycline (TGC)-induced hypofibrinogenemia (HF) in critically ill patients. Methods: A retrospective cohort study was conducted in intensive care unit patients treated with TGC. The clinical data and serum concentration were extracted from the patients’ electronic medical records. Patients were divided into an HF group and a normal group according to fibrinogen value. The receiver operating characteristic curves and logistic regression were used to derive serum concentration thresholds and quantify the association between exposure thresholds and HF while adjusting for confounders. Results: In total, 100 patients were included. The receiver operating characteristic curves analysis showed that TGC concentration parameters were strongly predictive of HF. Adjusting for duration of TGC, serum concentration at the 6 hours after the dosing (C1/2) ≥ 0.645 mg/l, area under the concentration-time curve over a 24-hour period (AUC 0-24) ≥ 20.76 mg·h/l, and serum concentration of 30 minutes before next dose (Cmin) ≥ 0.455 mg/l were associated with a three- to five-fold increased risk of TGC-induced HF in logistic regression. Conclusion: The findings from this study provide evidence that TGC exposure is highly predictive of HF, with an approximately three- to five-fold increased risk. Serum concentration at the 6 hours after the dosing (C1/2) ≥ 0.645 mg/l with best area under the receiver operating characteristic curve and negative predictive value appears to be the most appropriate toxicity threshold.

ObjectiveTo explore the application value of 3D scanning to obtain the parameters of transverse axis of medial longitudinal arch of foot in the biomechanical evaluation of transverse axis of medial longitudinal arch of foot in children.MethodThe feet of children with flat foot, normal foot and high arched foot were scanned with the Foot Secret 3D scanner in the sitting and standing positions. The scanning data were imported into CATIA v5 software for measurement, to obtain four parameters of transverse axis of medial longitudinal arch from transverse arch angle, external transverse arch angle, curvature and transverse arch cross-sectional area.ResultThere were statistically significant difference in transverse arch angle, external transverse arch angle and cross-sectional area between sitting and standing positions (p

As a raw material for producing chemical fertilizers, ammonia plays an essential role in human production and life. Due to the severe energy consumption and pollution caused by the industrial Haber–Bosch process of NH3 synthesis, developing the NH3 synthesis reaction under ambient conditions is vital. Electrochemical nitrogen reduction reaction (NRR) has recently emerged as a potential method. However, its limited NH3 yield and selectivity are unsatisfactory. NO3 −, as an oxidized form of nitrogen, universally exists in drinking water (

Abstract As one of the most important chemicals and carbon‐free energy carriers, ammonia (NH3) has significant energy‐related applications in industry and agriculture. Ninety percent of NH3 is produced by the Haber–Bosch process using high‐purity N2 and H2 at high temperatures and pressures, which consumes about 1% of the total energy production and causes 1.4% of global CO2 emissions. The environmentally friendly electrochemical nitrogen reduction reaction (NRR) with low energy consumption is a promising alternative to the conventional Haber–Bosch process. However, the main issue is the low Faradaic efficiency and NH3 selectivity of electrochemical NRR, caused by inert nitrogen molecules and competitive hydrogen evolution reaction. As one of the cheapest and most abundant transition metals widely utilized in the Haber–Bosch process, the Fe element has presented the potential high performance for the electrochemical NRR. This article summarizes recent advances and research progress in non‐noble Fe‐based catalysts used for NH3 electrosynthesis. Various synthetic protocols, structure/morphology modification, performance improvement, and reaction mechanisms are comprehensively presented. Based on recent experimental and theoretical studies, we aim to illuminate the structure–property relationship and offer an excellent opportunity for engineering advanced Fe‐based catalysts for nitrogen fixation. The most critical challenges and opportunities for Fe‐based catalysts are also provided. This review would open up a promising avenue toward developing platinum‐group‐metal‐free catalysts for electrochemical NRR applications in the future.

Abstract As a new generation of high‐efficiency energy storage devices, lithium–sulfur (Li–S) battery attract increasing attention. However, slow conversion kinetics of lithium polysulfides (LiPSs) and severe shuttle effect are bottlenecks. Developing efficient sulfur host materials to suppress the shuttling of LiPSs and accelerate their conversion kinetics is a general strategy to enhance the performance of Li–S batteries. Herein, MoS2 quantum dots (QDs)@MgB2 nanosheet was synthesized using a simple liquid‐phase mixing method. The MoS2 QDs not only inhibit the stacking of MgB2 nanosheets but also expose more unsaturated metal active sites, which can effectively improve the adsorption of LiPSs, accelerate its catalytic conversion and suppress its shuttle effect. Moreover, MgB2 nanosheets can be used as polypropylene (PP) separator modifier. The battery using MoS2 QDs@MgB2 as the sulfur host material and MgB2@PP as the separator has high rate capability and excellent stability. In addition, the discharge‐specific capacity shows a good application prospect.

Recent observation demonstrated that prolonged anesthesia modifies brain synaptic architecture in all ages, including adult. Propofol is the most commonly utilized anesthetics at clinic. Whether repeated administration of propofol modulates cognitive impairment in adults and changes synaptic plasticity remains, however, to be explored. In this study, we first discovered that repeated and prolonged exposure to propofol-induced cognitive impairment in adult rodents. Then, we examined the property of hippocampal primary neurons and slices after propofol treatment in mice, including synaptic protein profile, dendritic spine density, as well as synaptic transmission. We found the distinctive change of the F-box only protein 22 (FBXO22), an F-box E3 ligase, during this process and further explored its role. Knockdown experiments showed the downregulation of FBXO22 restored the changes by propofol treatment on hippocampal primary neurons and attenuated propofol-induced hippocampal dependent cognitive dysfunction. Our results showed that FBXO22 is involved in the regulation of repeated propofol treatment induced changes of synaptic plasticity and cognitive dysfunction in adult mice. Repeated propofol treatment leads to cognitive dysfunction by regulating FBXO22 in adult rodents.

Neural networks have been widely used for advanced tasks from image recognition to natural language processing. Many recent works focus on improving the efficiency of executing neural networks in diverse applications. Researchers have advocated processing‐in‐memory (PIM) architecture as a promising candidate for training and testing neural networks because PIM design can reduce the communication cost between storage and computing units. However, there exist noises in the PIM system generated from the intrinsic physical properties of both memory devices and the peripheral circuits. The noises introduce challenges in stably training the systems and achieving high test performance, e.g., accuracy in classification tasks. This review discusses the current approaches to tolerating noise effects for both training and inference in PIM systems and provides an analysis from a hardware–software codesign perspective. Noise‐tolerant strategies for PIM systems based on resistive random‐access memory (ReRAM), including circuit‐level, algorithm‐level, and system‐level solutions are explained. In addition, we also present some selected noise‐tolerate cases in PIM systems for generative adversarial networks and physical neural networks.

Abstract Background At 10 a.m. on January 23, 2020 Wuhan, China imposed a 76-day travel lockdown on its 11 million residents in order to stop the spread of COVID-19. This lockdown represented the largest quarantine in the history of public health and provides us with an opportunity to critically examine the relationship between a city lockdown on human mobility and controlling the spread of a viral epidemic, in this case COVID-19. This study aims to assess the causal impact of the Wuhan lockdown on population movement and the increase of newly confirmed COVID-19 cases. Methods Based on the daily panel data from 279 Chinese cities, our research is the first to apply the synthetic control approach to empirically analyze the causal relationship between the Wuhan lockdown of its population mobility and the progression of newly confirmed COVID-19 cases. By using a weighted average of available control cities to reproduce the counterfactual outcome trajectory that the treated city would have experienced in the absence of the lockdown, the synthetic control approach overcomes the sample selection bias and policy endogeneity problems that can arise from previous empirical methods in selecting control units. Results In our example, the lockdown of Wuhan reduced mobility inflow by approximately 60 % and outflow by about 50 %. A significant reduction of new cases was observed within four days of the lockdown. The increase in new cases declined by around 50% during this period. However, the suppression effect became less discernible after this initial period of time. A 2.25-fold surge was found for the increase in new cases on the fifth day following the lockdown, after which it died down rapidly. Conclusions Our study provided urgently needed and reliable causal evidence that city lockdown can be an effective short-term tool in containing and delaying the spread of a viral epidemic. Further, the city lockdown strategy can buy time during which countries can mobilize an effective response in order to better prepare. Therefore, in spite of initial widespread skepticism, lockdowns are likely to be added to the response toolkit used for any future pandemic outbreak.

As one of the core working parts of a combine harvester, the cleaning device directly affects the operation performance of the whole machine. This is especially the case on hilly and gently sloping terrain, which, due to the uneven ground, causes the combine harvester body to incline and material to accumulates on one side, resulting in a high cleaning loss rate. To solve this problem, a self-leveling cleaning screen device and a control system based on a fuzzy PID control algorithm are developed for a caterpillar harvester, enabling it to operate on gentle slopes of 10°. To verify the performance of the fuzzy PID algorithm applied to this system, simulation tests, response tests, comparison tests, and field tests were carried out. The indoor test results show that the system has a good tracking effect when the inclination amplitude does not exceed 10°. The maximum leveling error is −0.62°, the maximum leveling time is 1.85 s, and the maximum overshoot is 1.5°. The field test results show that when the tilt angle of the harvester body is within 10°, the system can stabilize the real-time leveling of the cleaning screen. Even with an increase in the tilt angle of the harvester, the cleaning loss of the harvester installed with the automatic leveling system can still be maintained at a low level. The cleaning loss rate of the harvester is 1.2% higher after leveling than during flat operation, which meets the accuracy requirements of the system design. Therefore, this system can be applied to grain combine harvesters and effectively reduce the cleaning loss caused by their operation.

Background: The causal relationship between physical activity (PA) and systemic lupus erythematosus (SLE) remains uncertain. We aimed to assess the causal effect of PA on SLE by two-sample Mendelian randomization (MR) study.Methods: Summary statistics of SLE were obtained from a genome-wide association study (GWAS) meta-analysis of European descent, including 4,036 cases and 6,959 controls. Genetic instruments for PA, including MVPA, VPA, SSOE, and average acceleration, were identified from a large-scale GWAS meta-analysis among 377,234 individuals of European ancestry from United Kingdom biobank and Atherosclerosis Risk in Communities (ARIC) study, and another GWAS with 91,105 European participants was employed for sedentary behavior. The two-sample MR study was conducted to estimate causal relationship between PA and SLE, with the inverse-variance weighted (IVW) method, simple- and weighted-median method. Moreover, MR-Egger regression, MR-PRESSO and leave-one-out analysis were performed to evaluate the potential pleiotropy effect.Results: In the end, we totally selected 37 SNPs (15 SNPs for MVPA, 5 SNPs for VPA, 9 SNPs for SSOE, 5 SNPs for average acceleration and 3 SNPs for sedentary behavior). According to the IVW results, as the primary method, we found that genetically predicted PA was not causally associated with risk of SLE (MVPA: OR 0.44, 95% CI 0.09–2.10, p = 0.305; VPA: OR 0.20, 95% CI 0.00–18.97, p = 0.490; SSOE: OR 0.96, 95% CI 0.03–29.24, p = 0.983; average acceleration: OR 0.91, 95% CI 0.79–1.05, p = 0.190; sedentary behavior: OR 1.54, 95% CI 0.35–6.81, p = 0.572). MR-Egger, MR-PRESSO, and leave-one-out analysis did not indicate horizontal pleiotropy.Conclusions: Our MR study suggested that genetically predicted PA was not causally associated with SLE among the European populations.

Abstract Polygonisation is a common nonuniform wear phenomenon occurring in railway vehicle wheels and has a severe impact on the vehicle–track system, ride comfort, and lineside residents. This paper first summarizes periodic defects of the wheels, including wheel polygonisation and wheel corrugation, occurring in railways worldwide. Thereafter, the effects of wheel polygonisation on the wheel–rail interaction, noise and vibration, and fatigue failure of the vehicle and track components are reviewed. Based on the different causes, the formation mechanisms of periodic wheel defects are classified into three categories: (1) initial defects of wheels, (2) natural vibration of the vehicle–track system, and (3) thermoelastic instability. In addition, the simulation methods of wheel polygonisation evolution and countermeasures to mitigate wheel polygonisation are presented. Emphasis is given to the characteristics, effects, causes, and solutions of wheel polygonisation in metro vehicles, locomotives, and high-speed trains in China. Finally, the guidance is provided on further understanding the formation mechanisms, monitoring technology, and maintenance criterion of wheel polygonisation.

The digging depth is an important factor affecting the mechanized garlic harvesting quality. At present, the digging depth of the garlic combine harvester (GCH) is adjusted manually, which leads to disadvantages such as slow response, poor accuracy, and being very dependent on the operator’s experience. To solve this problem, this paper proposes a machine vision-based automatic digging depth control system for the original garlic digging device. The system uses the improved YOLOv5 algorithm to calculate the length of the garlic root at the front end of the clamping conveyor chain in real-time, and the calculation result is sent back to the system as feedback. Then, the STM32 microcontroller is used to control the digging depth by expanding and contracting the electric putter of the garlic digging device. The experimental results of the presented control system show that the detection time of the system is 30.4 ms, the average accuracy of detection is 99.1%, and the space occupied by the model deployment is 11.4 MB, which suits the design of the real-time detection of the system. Moreover, the length of the excavated garlic roots is shorter than that of the system before modification, which represents a lower energy consumption of the system and a lower rate of impurities in harvesting, and the modified system is automatically controlled, reducing the operator’s workload.

Engineering atomically dispersed metal site catalysts with controlled local coordination environments and 3D nanostructures effectively improves the catalytic performance for the oxygen reduction reaction (ORR) and the carbon dioxide reduction reaction (CO2RR), which are critical for clean energy conversion and chemical production. Herein, an innovative approach for preparing core−shell nanostructured catalysts with different single‐metal sites in the core and the shell, respectively, is developed. In particular, as the shell precursors, covalent organic polymers with a thin layered structure that is polymerized in situ and coated on a metal‐doped ZIF‐derived carbon core are used, followed by a controlled thermal activation. The selective combination and construction of different metal sites increase active site density in the surface layers, promote structural robustness, facilitate mass/charge transfer, and yield a possible synergy of active sites in the core and the shell. The p‐FeNC(shell)@CoNC(core), consisting of a polymerized FeTPPCl‐derived carbon layer (p‐FeNC) on a Co‐doped ZIF‐derived carbon (CoNC), exhibits remarkable ORR activity and stability in acidic media along with encouraging durability in H2–air fuel cells. Likewise, a p‐FeNC(shell)@NiNC(core) catalyst demonstrates outstanding CO2RR activity and stability. Hence, integrating two appropriate single‐metal sites in core and shell precursors, respectively, can modulate morphological and catalytic properties for a possible synergy toward different electrocatalysis processes.

The C-eigenpair of piezoelectric tensors finds applications in the area of the piezoelectric effect and converse piezoelectric effect. In this paper, we provide some characterizations of C-eigenvectors by exploring the structure of piezoelectric tensors, and establish sharp C-eigenvalue inclusion intervals via Cauchy–Schwartz inequality. Further, we propose the lower and upper bounds of the largest C-eigenvalue and evaluate the efficiency of the best rank-one approximation of piezoelectric tensors. Numerical examples are proposed to verify the efficiency of the obtained results.

Abstract Background The CRISPR/Cas9 system, composed of a single-guide RNA for target recognition and a Cas9 protein for DNA cleavage, has the potential to revolutionize agriculture as well as medicine. Even though extensive work has been done to improve the gene editing activity of CRISPR/Cas9, little is known about the regulation of this bacterial system in eukaryotic host cells, especially at the post-transcriptional level. Results Here, we evaluate the expression levels of the two CRISPR/Cas9 components and the gene editing efficiency in a set of Arabidopsis mutants involved in RNA silencing. We find that mutants defective in the post-transcriptional gene-silencing pathway display significantly higher Cas9 and sgRNA transcript levels, resulting in higher mutagenesis frequencies than wild-type controls. Accordingly, silencing of AGO1 by introduction of an AGO1-RNAi cassette into the CRISPR/Cas9 vector provides an increase in gene editing efficiency. Co-expression of the viral suppressor p19 from the tomato bushy stunt virus to suppress the plant RNA-silencing pathway shows a strong correlation between the severity of the phenotypic effects caused by p19 and the gene editing efficiency of the CRISPR/Cas9 system for two different target genes, AP1 and TT4. Conclusions This system has useful practical applications in facilitating the detection of CRISPR/Cas9-induced mutations in T1 plants as well as the identification of transgene-free T2 plants by simple visual observation of the symptom severity caused by p19. Our study shows that CRISPR/Cas9 gene editing efficiency can be improved by reducing RNA silencing in plants.

Background: Our study aimed to examine the effects of COVID-19 on the physical fitness and academic performance of Chinese college students. Participants: The sample included physical fitness test data from 9,712 undergraduate students and academic performance data from 12,000 undergraduate students at a top university in China. Methods: Physical fitness was measured and evaluated according to the Chinese National Student Physical Fitness Standard. Data were analyzed using two-sample t-tests and Pearson product-moment correlations. Results: Total physical fitness test scores of college students decreased after the outbreak, but their mean body mass index (BMI) remained at normal levels. The mean academic performance of college students unexpectedly improved during the online learning period. The positive correlation between physical test scores and academic performance was significantly higher during COVID-19 than that before the outbreak. Conclusions: Chinese college students with high physical fitness during COVID-19 were more likely to achieve good academic performance.

A Ni/meso-MgO catalyst with high surface area and small Ni nanoparticles was synthesized and investigated for hydrogen production by steam reforming of phenol for the first time. Compared to conventional Ni/MgO, the Ni/meso-MgO catalyst showed higher catalytic activity and stability. X-ray Diffraction, N2 adsorption, hydrogen temperature programmed reduction, transmission electron microscopy and thermal gravimetry results indicated that the Ni/meso-MgO catalyst had higher surface area than Ni/MgO and Ni particles of Ni/meso-MgO were narrowly distributed in the range of 5~6 nm with an average size of 5.3 nm, while Ni particles of Ni/MgO were in the range of 6~10 nm with an average size of 7.92 nm. The small and uniform Ni nanoparticles in Ni/meso-MgO were attributed to the high surface area and the confinement effect of the mesoporous structure of meso-MgO, which could effectively limit the growth of the active metal and stabilize Ni particles during the procedure of NiO reduction. The mesoporous structure of Ni/meso-MgO also played an important role in suppressing Ni nanoparticle sintering and carbon deposition during the steam reforming of phenol reaction.

The hyper-arid western Namib Sand Sea (mean annual rainfall 0-17 mm) is a detritus-based ecosystem in which primary production is driven by large, but infrequent rainfall events. A diverse Namib detritivore community is sustained by minimal moisture inputs from rain and fog. The decomposition of plant material in the Namib Sand Sea (NSS) has long been assumed to be the province of these detritivores, with beetles and termites alone accounting for the majority of litter losses. We have found that a mesophilic Ascomycete community, which responds within minutes to moisture availability, is present on litter of the perennial Namib dune grass Stipagrostis sabulicola. Important fungal traits that allow survival and decomposition in this hyper-arid environment with intense desiccation, temperature and UV radiation stress are darkly-pigmented hyphae, a thermal range that includes the relatively low temperature experienced during fog and dew, and an ability to survive daily thermal and desiccation stress at temperatures as high as 50°C for five hours. While rainfall is very limited in this area, fog and high humidity provide regular periods (≥ 1 hour) of sufficient moisture that can wet substrates and hence allow fungal growth on average every 3 days. Furthermore, these fungi reduce the C/N ratio of the litter by a factor of two and thus detritivores, like the termite Psammotermes allocerus, favor fungal-infected litter parts. Our studies show that despite the hyper-aridity of the NSS, fungi are a key component of energy flow and biogeochemical cycling that should be accounted for in models addressing how the NSS ecosystem will respond to projected climate changes which may alter precipitation, dew and fog regimes.