Search

Most of current prostheses can offer motor function restoration for limb amputees but usually lack natural and intuitive sensory feedback. Many studies have demonstrated that Transcutaneous Electrical Nerve Stimulation (TENS) is promising in non-invasive sensation evoking for amputees. However, the objective evaluation and mechanism analysis on sensation feedback are still limited. This work utilized multi-channel TENS with diverse stimulus patterns to evoke sensations on four non-disabled subjects and two transradial amputees. Meanwhile, electroencephalogram (EEG) was collected to objectively assess the evoked sensations, where event-related potentials (ERPs), brain electrical activity maps (BEAMs), and functional connectivity (FC) were computed. The results show that various sensations could be successfully evoked for both amputees and non-disabled subjects by customizing stimulus parameters. The ERP confirmed the sensation and revealed the sensory-processing-related components like N100 and P200; the BEAMs confirmed the corresponding regions of somatosensory cortex were activated by stimulation; the FC indicated an increase of interactions between the regions of sensorimotor cortex. This study may shed light on how the brain responds to external stimulation as sensory feedback and serve as a pilot for further bidirectional closed-loop prosthetic control.

Electrophysiological recordings are vital in assessing biological functions, diagnosing diseases, and facilitating biofeedback and rehabilitation. The applications of conventional wet (gel) electrodes often come with some limitations. Microneedle array electrodes (MAEs) present a possible solution for high-quality electrophysiological acquisition, while the prior technologies for MAE fabrication have been either complex, expensive, or incapable of producing microneedles with uniform dimensions. This work employed a projection stereolithography (P $\mu $ SL) 3D printing technology to fabricate MAEs with micrometer-level precision. The MAEs were compared with gel and flat electrodes on electrode-skin interface impedance (EII) and performances of EMG and ECG acquisition. The experimental results indicate that the P $\mu $ SL 3D printing technology contributed to an easy-to-perform and low-cost fabrication approach for MAEs. The developed MAEs exhibited promising EII and enabled a stable EMG and ECG acquisition in different conditions without inducing skin allergies, inflammation, or injuries. This research lies in the development of a type of customizable MAE with considerable biomedical application potentials for ultra-minimally invasive or non-invasive electrophysiological acquisition.

This study was aimed to analyze the effect of procyanidin B2 (PC) and tannin acid (TA) on the activities of cholesterol esterase (CEase) and the inhibitory mechanisms of enzymatic activity. The interaction mechanisms were investigated by enzymatic kinetics, multi-spectroscopy methods, thermodynamics analysis, molecular docking, and dynamic simulations. PC and TA could bind with CEase and inhibit the activity of enzyme in a mixed-competitive manner and non-competitive manner, which was verified by molecular docking simulations and dynamics simulations. Also, PC and TA showed the synergistic inhibition with orlistat. Fluorescence, UV-vis and the thermodynamic analysis revealed that the complexes were formed from CEase and inhibitors by noncovalent interaction. As revealed by the circular dichroism results, both PC and TA decreased enzymatic activities by altering the conformations of CEase. The inhibition of PC and TA on CEase might be one mechanism for its cholesterol-lowering effect.

Food allergy as a global health problem threatens food industry. Bee pollen (BP) is a typical food with allergenic potentials, although it performs various nutritional/pharmacological functions to humans. In this study, lactic acid bacteria (LAB) were used to ferment Brassica napus BP for alleviating its allergenicity. Four novel allergens (glutaredoxin, oleosin-B2, catalase and lipase) were identified with significant decreases in LAB-fermented BP (FBP) than natural BP by proteomics. Meanwhile, metabolomics analysis showed significant increases of 28 characteristic oligopeptides and amino acids in FBP versus BP, indicating the degradation of LAB on allergens. Moreover, FBP showed alleviatory effects in BALB/c mice, which relieved pathological symptoms and lowered production of allergic mediators. Microbial high-throughput sequencing analysis showed that FBP could regulate gut microbiota and metabolism to strengthen immunity, which were closely correlated with the alleviation of allergic reactivity. These findings could contribute to the development and utilization of hypoallergenic BP products.

Abstract Realizing efficient energy utilization from the heat source of the sun and the cold source of outer space is of great significance for addressing the global energy and environmental crisis. Materials with ideal full‐spectrum solar absorption and infrared emission are highly desirable for adapting to the continuous weather dynamic throughout the day, nonetheless, their development remains challenging. Here, a polymer nanocomposite with full‐spectrum strong solar (280–2500 nm) absorption ranging from 88.8% to 94.8% with an average value of 93.2% and full‐spectrum high infrared (8–13 µm) emission ranging from 81.3% to 90.0% with an average value of 84.2%, is reported by melt‐processing polypropylene and uniformly dispersed low‐loading MXene nanosheets (1.9 vol%). The nanocomposite can achieve daytime photothermal enhancement of ≈50 °C and nighttime radiative cooling of 8 °C. The temperature difference throughout the day ensures all‐day uninterrupted thermoelectric generation, yielding a power density output of 1.5 W m−2 (daytime) and 7.9 mW m−2 (nighttime) in real outdoor environment without any additional energy consumption. This work provides an impressive polymer nanocomposite with ideal full‐spectrum solar absorption and infrared emission for all‐day uninterrupted thermal energy management and conversion.

Oxygen uptake (V˙O2) is an essential metric for evaluating cardiopulmonary health and athletic performance, which can barely be directly measured. Heart rate (HR) is a prominent physiological indicator correlated with V˙O2 and is often used for indirect V˙O2 prediction. This study investigates the impact of HR placement on V˙O2 prediction accuracy by analyzing HR data combined with the respiratory rate (RESP) and minute ventilation (V˙E) from three anatomical locations: the chest; arm; and wrist. Twenty-eight healthy adults participated in incremental and constant workload cycling tests at various intensities. Data on V˙O2, RESP, V˙E, and HR were collected and used to develop a neural network model for V˙O2 prediction. The influence of HR position on prediction accuracy was assessed via Bland–Altman plots, and model performance was evaluated by mean absolute error (MAE), coefficient of determination (R2), and mean absolute percentage error (MAPE). Our findings indicate that HR combined with RESP and V˙E (V˙O2HR+RESP+V˙E) produces the most accurate V˙O2 predictions (MAE: 165 mL/min, R2: 0.87, MAPE: 15.91%). Notably, as exercise intensity increases, the accuracy of V˙O2 prediction decreases, particularly within high-intensity exercise. The substitution of HR with different anatomical sites significantly impacts V˙O2 prediction accuracy, with wrist placement showing a more profound effect compared to arm placement. In conclusion, this study underscores the importance of considering HR placement in V˙O2 prediction models, with RESP and V˙E serving as effective compensatory factors. These findings contribute to refining indirect V˙O2 estimation methods, enhancing their predictive capabilities across different exercise intensities and anatomical placements.

The foreseeable global animal production pressure has triggered people to search for sustainable novel feed resources. As the most abundant species in the world, insects are considered to be an alternative feed source. This review is to give comprehensive analysis of the insect as animal feed. In recent years, insect feed has been used in poultry, livestock production, aquaculture and pets. Positive impacts of using insect as feed source include nutritional enrichment, economic benefits and environmental merits. Also, barriers of using insects as feed related to animal products evaluation, insect breeding scale, consumer acceptance and legislation. This paper will be helpful in laying the foundation for the in-depth development and utilization of insect feed resources.

Prevalence of kidney stones has increased continously over several decades worldwide, the major causes of which are largely unknown. To explore the dietary causes of kidney stones, and reveal mechanisms underlying dietary risk factors inducing kidney stones, animal experiments using mice as the disease model were performed. Eight-week old male CD-1 mice were treated by ethylene glycol, cholesterol or/and apple tannins for 3 d, respectively. In the present study, the crystalline analysis in urine and kidney tissues, HE staining kidney sections as well as observation of micro-stones, tannins and cholesterol deposition in kidneys of mice in different groups were conducted. We found that gavage with ethylene glycol, cholesterol and tannins resulted in mice urine solute supersaturation in renal tubules and forming kidney stones. Significant cholesterol and tannin deposits in mouse kidney were observed by laser confocal microscopy and crystals were shown either adhered with or co-deposited with cholesterol and tannin deposits. The primary crystals were found in renal cortex, medullar, especially papilla in the kidney sections under polarized microscope. These findings demonstrate that interaction of cholesterol and tannins in kidney plays a critical role in the formation of kidney stones.

Benzene poisoning can cause acute myeloid leukemia (AML) through a variety of passways. Tim-3 has gained prominence as a potential candidate in mediating immunosuppression in tumor microenvironments. The macrophage polarization is also related to immune escape. Herein, we reported that Tim-3 and macrophage M2 polarization play a vital role in benzene-induced AML. First, the benzene-induced AML C3H/He mouse model was constructed by subcutaneously injecting 250 mg/kg of benzene. After six months, macrophage phenotype, cytokines, and Tim-3 expression levels were investigated. Flow cytometry assay revealed that the T-cell inhibitory receptor Tim-3 was significantly upregulated in both bone marrow and spleen of the benzene-induced AML mouse model. Elisa's results displayed a decreased serum level of IL-12 while increased TGF-β1. Mechanistically, changes in cytokine secretion promote the growth of M2-type macrophages in the bone marrow and spleen, as determined by immunofluorescence assay. The increased levels of PI3K, AKT, and mTOR in the benzene-exposure group further proved the crucial role of Tim-3 in regulating the functional status of macrophages in the AML microenvironment. These results demonstrate that Tim-3 and macrophage polarization may play a vital role during the immune escape of the benzene-induced AML. This study provides a new potential intervention site for immune checkpoint-based AML therapeutic strategy.

Accurate hand motion intention recognition is essential for the intuitive control of intelligent prosthetic hands and other human-machine interaction systems. Sonomyography, which can detect the changes in muscle morphology and structure precisely, is a promising signal source for fine hand movement recognition. However, sonomyography measured by traditional rigid ultrasound probes may suffer from poor acoustic coupling because the rigid probe surfaces cannot accommodate the curvilinear shape of the human body, particularly in the case of small and irregular residual limbs in amputees. In this study, we used a self-designed lightweight, flexible, and wearable ultrasound transducer to acquire muscle ultrasound images, and proposed a sonomyography transformer (SMGT) model for simultaneous recognition of hand movements and force levels. The performance of SMGT was systematically compared to two commonly used image processing methods, HOG and Gray Gradient, as well as a deep CNN model, in simultaneously recognizing ten classes of hand/finger movements and three force levels. Additionally, ten subjects including seven non-disabled subjects and three trans-radial amputees who are the end users of prosthetic hands were recruited to evaluate the effectiveness of SMGT. Results showed that our proposed method achieved average classification accuracies of 98.4% ± 0.6% and 96.2% ± 3.0% in non-disabled subjects and amputee subjects, respectively, which are much higher than those of other methods. This study provided a valuable approach for ultrasound-based hand motion recognition that may promote the applications of intelligent prosthetic hands.

Electroencephalogram (EEG) recordings often contain artifacts that would lower signal quality. Many efforts have been made to eliminate or at least minimize the artifacts, and most of them rely on visual inspection and manual operations, which is time/labor-consuming, subjective, and incompatible to filter massive EEG data in real-time. In this paper, we proposed a deep learning framework named Artifact Removal Wasserstein Generative Adversarial Network (AR-WGAN), where the well-trained model can decompose input EEG, detect and delete artifacts, and then reconstruct denoised signals within a short time. The proposed approach was systematically compared with commonly used denoising methods including Denoised AutoEncoder, Wiener Filter, and Empirical Mode Decomposition, with both public and self-collected datasets. The experimental results proved the promising performance of AR-WGAN on automatic artifact removal for massive data across subjects, with correlation coefficient up to 0.726±0.033, and temporal and spatial relative root-mean-square error as low as 0.176±0.046 and 0.761±0.046, respectively. This work may demonstrate the proposed AR-WGAN as a high-performance end-to-end method for EEG denoising, with many on-line applications in clinical EEG monitoring and brain-computer interfaces.

To shorten the complex and time-consuming process of the identification method of the traditional food angiotensin-I-converting enzyme (ACE-I) inhibitory peptides, we propose AHTPeptideFusion based on a segmented fusion with the protein language model and deep learning. The statistical analysis found that hydrophobic amino acids, N-terminal valine is a dominant amino acid in the activity of ACE-I inhibitory peptides. In 12 machine learning (ML) algorithms, the transformer outperformed the other 11 models, with the best performance in predicting short and medium peptides. In the external dataset, AHTPeptideFusion fused by transformer and random forest (RF) showed excellent performance (accuracy > 0.9) in predicting ACE-I inhibitory peptides with lengths ranging from 2 to 15 amino acid residues and different activity distributions, and the reliability and accuracy of AHTPeptideFusion was demonstrated by synthetic peptide and ACE-I inhibition experiments. In addition, hydrogen bonding and electrostatic interaction between 4 synthetic peptides and active residues of ACE-I were found by molecular docking. To further explore the ACE-I inhibitory peptides from animal-derived foods, we established an automated pipeline consisting of the trinity of proteomics, virtual enzymatic digestion and AHTPeptideFusion, and tapped the ACE-I inhibitory peptide released from royal jelly after digestion in the gastrointestinal tract. In conclusion, this computational pipeline will become a powerful screening tool for active peptides from animal-derived foods, which can help food scientists accelerate the mining and design of active peptides from animal-derived foods. Overall, AHTPeptideFusion will be a powerful ACE-I inhibitor peptide prediction tool, it can help food scientists accelerate the mining and design of ACE-I inhibitory peptides.

Dual-frequency ultrasounds have demonstrated significant potential in augmenting thermal ablation efficiency for tumor treatment. Ensuring proper impedance matching between the dual-frequency transducer and the power amplifier system is imperative for equipment safety. This paper introduces a novel dual-frequency impedance matching network utilizing L-shaped topology and employing a genetic algorithm to compute component values. Implementation involved an adjustable capacitor and inductor network to achieve dual-frequency matching. Subsequently, the acoustic parameters of the dual-frequency HIFU transducer were evaluated before and after matching, and the effects of ultrasound thermal ablation with and without matching were compared. The proposed dual-frequency impedance matching system effectively reduced the standing wave ratio at the two resonance points while enhancing transmission efficiency. Thermal ablation experiments with matching circuits showed improved temperature rise efficiencies at both frequencies, resulting in an expanded ablation zone. The dual-frequency impedance matching method significantly enhances the transmission efficiency of the dual-frequency ultrasound system at two operational frequencies, thereby ensuring equipment safety. It holds promising prospects for application in dual-frequency ultrasound treatment.

Synergetic recovery of both somatosensory and motor functions is highly desired by limb amputees to fully regain their lost limb abilities. The commercially available prostheses can restore the lost motor function in amputees but lack intuitive sensory feedback. The previous studies showed that electrical stimulation on the arm stump would be a promising approach to induce sensory information into the nervous system, enabling the possibility of realizing sensory feedback in limb prostheses. However, there are currently limited studies on the effective evaluation of the sensations evoked by transcutaneous electrical nerve stimulation (TENS). In this paper, a multichannel TENS platform was developed and the different stimulus patterns were designed to evoke stable finger sensations for a transradial amputee. Electroencephalogram (EEG) was recorded simultaneously during TENS on the arm stump, which was utilized to evaluate the evoked sensations. The experimental results revealed that different types of sensations on three phantom fingers could be stably evoked for the amputee by properly selecting TENS patterns. The analysis of the event-related potential (ERP) of EEG recordings further confirmed the evoked sensations, and ERP latencies and curve characteristics for different phantom fingers showed significant differences. This work may provide insight for an in-depth understanding of how somatosensation could be restored in limb amputees and offer technical support for the applications of non-invasive sensory feedback systems.

ObjectiveSensory feedback of upper-limb prostheses is widely desired and studied. As important components of proprioception, position, and movement feedback help users to control prostheses better. Among various feedback methods, electrotactile stimulation is a potential method for coding proprioceptive information of a prosthesis. This study was motivated by the need for proprioception information for a prosthetic wrist. The flexion-extension (FE) position and movement information of the prosthetic wrist are transmitted back to the human body through multichannel electrotactile stimulation.ApproachWe developed an electrotactile scheme to encode the FE position and movement of the prosthetic wrist and designed an integrated experimental platform. A preliminary experiment on the sensory threshold and discomfort threshold was performed. Then, two proprioceptive feedback experiments were performed: a position sense experiment (Exp 1) and a movement sense experiment (Exp 2). Each experiment included a learning session and a test session. The success rate (SR) and discrimination reaction time (DRT) were analyzed to evaluate the recognition effect. The acceptance of the electrotactile scheme was evaluated by a questionnaire.Main resultsOur results showed that the average position SRs of five able-bodied subjects, amputee 1, and amputee 2 were 83.78, 97.78, and 84.44%, respectively. The average movement SR, and the direction and range SR of wrist movement in five able-bodied subjects were 76.25, 96.67%, respectively. Amputee 1 and amputee 2 had movement SRs of 87.78 and 90.00% and direction and range SRs of 64.58 and 77.08%, respectively. The average DRT of five able-bodied subjects was less than 1.5 s and that of amputees was less than 3.5 s.ConclusionThe results indicate that after a short period of learning, the subjects can sense the position and movement of wrist FE. The proposed substitutive scheme has the potential for amputees to sense a prosthetic wrist, thus enhancing the human-machine interaction.

Wearing a myoelectric prosthesis is a basic way for limb amputees to restore their lost limb functions in the activities of daily living (ADLs). However, it is estimated that around 40% of amputees refuse the prosthesis. One of the primary reasons would be that the current prostheses lack appropriate sensory feedback. Currently, the amputees only depend on their visual feedback (Vis-FB) when using their arm prostheses. It would be difficult for them to accurately control the wrist position, which is vital for flexible manipulation in ADLs. This manuscript designed a myoelectric arm prosthesis with wrist position feedback (WP-FB). To study the effect level of position feedback on prosthetic control, two tests were performed. The vibrotactile perception range test aims to analyze the perception sensitivity of the vibration in humans and obtain the optimal perception range utilized in the sensory feedback test. The sensory feedback test analyzes the effectiveness of the position feedback by comparing three feedback methods of Vis-FB, WP-FB, and a combination of Vis-FB and WP-FB (VP-FB). These tests were conducted by asking six able-bodied subjects to perform 20 movement combinations of five target positions. The WP-FB was transiently activated with five vibrating motors embedded in an armband to stimulate the arm stump when the prosthetic wrist rotates to the target positions. Our experimental results showed that when WP-FB was added to the prosthetic control, the absolute angular error (AAE) of the prosthetic wrist declined from 4.50° to 1.08° while the success rate 3 (SR3) increased from 0.34 to 0.84, respectively. This study demonstrates the importance of WP-FB to the effective control of the arm prosthesis.

Surface electromyogram-based pattern recognition (sEMG-PR) has been considered as the most promising method to control multifunctional prostheses for decades. However, the commercial applications of sEMG-PR in prosthetic control is still limited due to the ambient noise and impedance variation between electrodes and skin surface. In order to reduce these issues, a force-myography-based pattern recognition method was proposed. In this method, a type of polymer-based flexible film sensors, the piezoelectrets, were used to record the rate of stress change (RSC) signals on the muscle surface of eight able-bodied subjects for six hand motions. Thirteen time domain features and four classification algorithms of linear discriminant analysis (LDA), K-nearest neighbor (KNN), artificial neural network (ANN), and support vector machine (SVM) were adopted to decode the RSC signals of different motion classes. In addition, the optimal feature set, classifier, and analysis window length were investigated systematically. Results showed that the average classification accuracy was 95.5 ± 2.2% by using the feature combination of root mean square (RMS) and waveform length (WL) for the classifier of KNN, and the analysis window length of 300 ms was found to obtain the best classification performance. Moreover, the robustness of the proposed method was investigated, and the classification accuracies were observed above 90% even when the white noise ratio increased to 50%. The work of this study demonstrated the effectiveness of RSC-based pattern recognition method for motion classification, and it would provide an alternative approach for the control of multifunctional prostheses.

Royal jelly is a specific product secreted by honeybees, and has been sought after to maintain health because of its valuable bioactive substances, e.g., lipids and vitamins. The lipids in royal jelly come from the bee pollen consumed by honeybees, and different plant source of bee pollen affects the lipid composition of royal jelly. However, the effect of bee pollen consumption on the lipid composition of royal jelly remains unclear. Herein, we examined the influence of two factors on the lipid composition of royal jelly: first, two plant sources of bee pollen, i.e., Acer mono Maxim. (BP-Am) and Phellodendron amurense Rupr. (BP-Pa); secondly, different feeding times. Lipidomic analyses were conducted on the royal jelly produced by honeybees fed BP-Am or BP-Pa using ultra-high performance liquid chromatography (UPLC)-Q-Exactive Orbitrap mass spectrometry. The results showed that the phospholipid and fatty acid contents differed in royal jelly produced by honeybees fed BP-Am compared to those fed BP-Pa. There were also differences between timepoints, with many lipid compounds decreasing in abundance soon after single-pollen feeding began, slowly increasing over time, then decreasing again after 30 days of single-pollen feeding. The single bee pollen diet destroyed the nutritional balance of bee colonies and affected the development of hypopharyngeal and maxillary glands, resulting in differences in royal jelly quality. This study provides guidance for optimal selection of honeybee feed for the production of high-quality royal jelly.

Mango (Mangifera indica L.) is an important tropical fruit with a delicate taste, pleasant aroma, and high nutritional value. In recent years, with the promotion of the rural revitalization strategy and the development of the poverty alleviation industry, China has gradually become an important mango producer. However, the short shelf life of mango fruit, the difficulty in regulating the postharvest quality, and the lack of preservation technology are the main problems that need to be solved in China‘s mango industry. In this paper, the physiological changes and mechanisms of mango during postharvest ripening were summarized, including sugar and acid changes, pigment synthesis and accumulation, and aroma formation and accumulation. The physical, chemical, and biological technologies (such as endogenous phytohormones, temperature, light, chemical preservatives, and edible coatings) commonly used in the regulation of mango postharvest ripening and their action principles were emphatically expounded. The shortcomings of the existing mango postharvest ripening regulation technology and physiological mechanism research were analyzed in order to provide a reference for the industrial application and development of mango postharvest.

Abstract Background Chronic Obstructive Pulmonary Disease (COPD) is a major cause of morbidity and mortality all over the world. Acute exacerbation of COPD (AECOPD) not only accelerates the progression of disease, but also causes hospital administration and death events. Epidemiologic studies have shown air pollution is a high risk factor of AECOPD. However, there are rare technics or treatment strategies recommended to reduce severe air pollution related AECOPD. Methods This is a multi-center, prospective, randomized and standard treatment parallel control clinical trial. Seven hundred sixty-four stable COPD patients in group B, C and D according to GOLD 2017 will be recruited and equally divided into two parallel groups, salvational intervention (SI group) and control group (CT group). Original treatments for participants include tiotropium (18μg once q.d), budesonide/formoterol (160μg/4.5μg once or twice b.i.d) or budesonide/formoterol (160μg/4.5μg once or twice b.i.d) with tiotropium (18μg once q.d). The savational intervention for SI group is routine treatment plus budesonide/formoterol (160μg/4.5μg once b.i.d) from the first day after severe air pollution (air quality index, AQI ≥200) to the third day after AQI

This study aimed to investigate that rapid high-temperature treatment (RHT) at an appropriate temperature could accelerate callus formation by effectively promoting the necessary metabolic pathways in sweet potato callus. In this study, the callus of sweet potato was treated with heat shock at 50, 65, and 80 °C for 15 min. The callus formation was observed within 1, 3, and 5 days, and the accumulation of intermediates in the metabolism of phenylpropane and reactive oxygen species and changes in enzyme activities were determined. The results showed that appropriate RHT treatment at 65 °C stimulated the metabolism of reactive oxygen species at the injury site of sweet potato on the first day, and maintained a high level of reactive oxygen species production and scavenging within 5 days. The higher level of reactive oxygen species stimulated the phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase and cinnamate-4-hydroxylase activities of the phenylpropane metabolic pathway, and promoted the rapid synthesis of chlorogenic acid, p-coumaric acid, rutin, and caffeic acid at the injury site, which stacked to form callus. By Pearson’s correlation analysis, catalase (CAT), PAL, and chlorogenic acid content were found to be strongly positively correlated with changes in all metabolites and enzymatic activities. Our results indicated that appropriate high-temperature rapid treatment could promote sweet potato callus by inducing reactive oxygen species and phenylpropane metabolism; moreover, CAT, PAL, and chlorogenic acid were key factors in promoting two metabolic pathways in sweet potato callus.

The low frequency oscillation is a serious threat to security and stability of a power grid. How to locate the disturbance source accurately is an important issue to low frequency oscillation disposal. Existing methods have poor adaptability to the low frequency oscillation with time-varying steady-state points because of the limitations in the location criterion derivation. A disturbance source location method on a low frequency oscillation with good generality is presented in the paper. Firstly, the reasons why the steady-state points are time-varying on a low frequency oscillation are analyzed. Then, based on the energy function construction form, the branch transmission energy is decomposed into state energy, reciprocating energy and dissipation energy by mathematical derivation. The flow direction of the dissipation energy shows the source and destination of the disturbance energy, and the specific location of a disturbance source can be identified according to its flow direction. Meanwhile, to meet the needs of energy calculation, a recognition method on the electrical quantities steady-state points is also presented by using the cubic spline interpolation. Simulation results show the correctness of the derivation and analysis on energy structure in the paper, and the disturbance source can be located accurately according to the dissipation energy.

The data presented here are related to the research article titled “Identification of circular RNAs and their alterations involved in developing male Xenopus laevis chronically exposed to atrazine” (Sai et al., 2018) [1]. Circular RNAs (circRNAs) are implicated in multiple developmental anomalies (Bachmayr-Heyda et al., 2015; Li et al., 2015) [2,3]. This report describes the differentially expressed circRNAs involved in developing male Xenopus laevis (X. laevis) chronically exposed to atrazine (AZ) database. The database contains the validation of differentially expressed circRNAs, KEGG analysis of differentially expressed circRNA-associated target genes and prediction of miRNA binding sites. These data may help to further evaluate the role of circRNAs in male X. laevis chronically exposed to AZ. Keywords: Herbicide, CircRNA, Q-RT-PCR, CircRNA-miRNA, KEGG, Reproductive toxicology

Background: The assessment of muscle properties is an essential prerequisite in the treatment of post-stroke patients with limb spasticity. Most existing spasticity assessment approaches do not consider the muscle activation with voluntary contraction. Including voluntary movements of spastic muscles may provide a new way for the reliable assessment of muscle spasticity.Objective: In this study, we investigated the effectiveness and reliability of maximum isometrics voluntary contraction (MIVC) based method for spasticity assessment in post-stroke hemiplegia.Methods: Fourteen post-stroke hemiplegic patients with arm spasticity were asked to perform two tasks: MIVC and passive isokinetic movements. Three biomechanical signals, torque, position, and time, were recorded from the impaired and non-impaired arms of the patients. Three features, peak torque, keep time of the peak torque, and rise time, were computed from the recorded MIVC signals and used to evaluate the muscle voluntary activation characteristics, respectively. For passive movements, two features, the maximum resistance torque and muscle stiffness, were also obtained to characterize the properties of spastic stretch reflexes. Subsequently, the effectiveness and reliability of the MIVC-based spasticity assessment method were evaluated with spearman correlation analysis and intra class correlation coefficients (ICCs) metrics.Results: The results indicated that the keep time of peak torque and rise time in the impaired arm were higher in comparison to those in the contralateral arm, whereas the peak torque in the impaired side was significantly lower than their contralateral arm. Our results also showed a significant positive correlation (r = 0.503, p = 0.047) between the keep time (tk) and the passive resistant torque. Furthermore, a significantly positive correlation was observed between the keep time (tk) and the muscle stiffness (r = 0.653, p = 0.011). Meanwhile, the ICCs for intra-time measurements of MIVC ranged between 0.815 and 0.988 with one outlier.Conclusion: The findings from this study suggested that the proposed MIVC-based approach would be promising for the reliable and accurate assessment of spasticity in post-stroke patients.

MgO is a kind of high secondary electron yield (SEY) material with important applications in electron multipliers. MgO coatings can be used as the electron emission layer for multiplier dynode to improve the electron gain significantly. However, the SEY investigation on ultrathin MgO coatings is not complete and needed to be supplemented urgently. In this work, a series of MgO coatings with increasing thickness were prepared by atomic layer deposition. SEY properties and energy spectra were characterized, and the effect of coating thickness on SEY was systematically analyzed. Experimental results show that SEY of MgO/Si samples rises as the coating thickness increases. Merely, SEY almost does not change with the coating thickness when the thickness exceeds 30 nm. Then, a SEY semi-empirical theory was employed to interpret the SEY regularities of MgO coatings by regarding the coating samples as ideal double-layer structures. Theoretical calculation quantitatively explained the SEY variation observed during the experiments, and further quantified the SEY contribution level of top coating and bottom substrate for the 1 nm and 20 nm MgO coatings. The work is of great significance for comprehending the SEY of ultrathin MgO coatings and expanding the applications of nanoscale coatings with high SEY.

Electromyogram (EMG) contains rich information for motion decoding. As one of its major applications, EMG-pattern recognition (PR)-based control of prostheses has been proposed and investigated in the field of rehabilitation robotics for decades. These prostheses can offer a higher level of dexterity compared to the commercially available ones. However, limited progress has been made toward clinical application of EMG-PR-based prostheses, due to their unsatisfactory robustness against various interferences during daily use. These interferences may lead to misclassifications of motion intentions, which damage the control performance of EMG-PR-based prostheses. A number of studies have applied methods that undergo a postprocessing stage to determine the current motion outputs, based on previous outputs or other information, which have proved effective in reducing erroneous outputs. In this study, we proposed a postprocessing strategy that locks the outputs during the constant contraction to block out occasional misclassifications, upon detecting the motion onset using a threshold. The strategy was investigated using three different motion onset detectors, namely mean absolute value, Teager–Kaiser energy operator, or mechanomyogram (MMG). Our results indicate that the proposed strategy could suppress erroneous outputs, during rest and constant contractions in particular. In addition, with MMG as the motion onset detector, the strategy was found to produce the most significant improvement in the performance, reducing the total errors up to around 50% (from 22.9 to 11.5%) in comparison to the original classification output in the online test, and it is the most robust against threshold value changes. We speculate that motion onset detectors that are both smooth and responsive would further enhance the efficacy of the proposed postprocessing strategy, which would facilitate the clinical application of EMG-PR-based prosthetic control.

Considering the ice shedding phenomena on ice-covered outdoor insulators, this paper conducted the artificial experiments by using a five-unit suspension ceramic insulator string covered with wet-grown ice to investigate the effects of ice shedding on the icing discharge characteristics. According to IEEE Standard 1783/2009, the minimum flashover voltage (VMF), propagation of discharges to flashover and related leakage current (LC) were measured. It was found that VMF after ice shedding can be increased by about 17% as compared with that before ice shedding. The initiation and formation of discharge arcs across ice-free regions caused by ice shedding become difficult, showing an unstable propagating path, indeterminate arc shape and longer arc column. Although VMF under ice shedding conditions is higher than that without ice shedding, the fundamental component, and harmonics show lower amplitudes for the latter case. The ratios of harmonics to the fundamental are well in accordance with discharge characteristics during the flashover for which the ratios show a relatively stable varying tendency in the absence of ice shedding, but show changeable and indeterminate variation under ice shedding conditions. The obtained results are helpful to understand the icing state and its influence on surface discharges for preventing the icing flashovers.

In order to satisfy demands for DC de-icing of optical fiber composite overhead ground wire (OPGW) and solve questions such as those relating to circulating current loss and liability of suffering from lightning strike, the grounding method of OPGW must be changed from the current commonly used method of being grounded at every tower to being grounded at one tower. The OPGW would be connected to the tower by an insulator, which is often shunt connected with a protective discharge clearance. The recommended value of the discharge clearance is from 70 to 80 mm. The lightning impulse discharge voltage of such a clearance is generally not more than 100 kV. However, as the transmission line is struck by lightning, over-voltage on the clearance is 885 kV at least, even up to a few MV. The clearance can be broken down reliably. The influence of insulation reconstruction for OPGW on the induced current and the power loss of the AC transmission line was studied by means of theoretical analysis and simulation calculations. Results indicate that change of the OPGW grounding mode could reduce the induced current of the ground wire to below 1 A and reduce the power loss of the line to below 1 W/km. Power loss could be reduced by over 99%. Adoption of a suitable grounding mode for OPGW is of great significance for DC de-icing, lightning protection safety, and energy savings for UHV projects.

Thaumatin-like protein from banana (designated BanTLP) has been purified by employing a simple protocol consisting of diethylaminoethyl Sephadex (DEAE–Sephadex) chromatography, gel filtration on Sephadex G50, and reversed-phase chromatography. The purified protein was identified by MALDI-TOF mass spectrometry, with an estimated molecular weight of 22.1 kDa. BanTLP effectively inhibited in vitro spore germination of Penicillium expansum, one of the main postharvest pathogens in fruits. This study further investigated the antifungal properties and underlying mechanisms of BanTLP against P. expansum. Results demonstrated that BanTLP exhibited antifungal activity in a wide pH range (4.0–10.0) at 20–50 °C. Propidium iodide (PI) influx and potassium release confirmed that BanTLP induced membrane disruption of the test pathogen, increasing the membrane permeability and disintegration of the cell. This led to cell death, as evidenced by the assays of thiobarbituric acid-reactive species (TBARS) content, the production of reactive oxygen species (ROS), and 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence integrity. Ultrastructural alterations in P. expansum conidia after BanTLP treatment revealed severe damage to the cell wall. These results suggest that BanTLP purified from banana exerts antifungal activity against P. expansum by inducing plasma membrane disturbance and cell wall disorganization.

AbstractThis study investigated the effects of laser energy density at different scanning speeds on the microstructure evolution, phase equilibrium, mechanical properties, and fracture modes of welds in dissimilar steel welded joints (Q345D and 20Mn2). The connection of dissimilar steel welded joints is achieved by using a laser synchronous powder feeding method. The microstructure and phase evolution of the joint were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Mechanical property testing was performed on the joint via a micro-Vickers hardness tester and an electronic testing machine, and the fracture surface morphology was observed via a scanning electron microscope. The results show that when the laser energy density is 1125 J/mm2, the fine cellular crystals, columnar crystals, and equiaxed crystal structures of the joint are more uniformly distributed. As the laser energy density increased, the transition of the Q345D side structure from cellular to columnar crystals and the transition of the 20Mn2 side structure from cellular to equiaxed crystals became more pronounced. Mechanical property testing revealed that an increase in the laser energy density can significantly improve the microhardness and tensile strength of a joint. However, a large amount of the Fe matrix from the 20Mn2 side permeates into the coating, making the mechanical properties of the dilution zone lower than those of the crystallization zone, and making it more prone to fracture on this side. The fracture analysis results show that the fracture mode has strong ductility, and the fracture mode is judged to be ductile fracture. [ABSTRACT FROM AUTHOR]