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Abstract To improve the heat extraction efficiency from the wellbore fluids to the stratum in the geothermal well, thermal insulation cement, which contains of waste glass powder as a heat-insulating material, is proposed to apply in geothermal well’s middle and upper sections in the paper. Effect of such glass powers on mechanic and thermal property of thermal insulation cement was then investigated. Various tests were carried out to measure compressive strength, thermal conductivity, microstructure porosity etc. parameters of the thermal insulation cement. Results showed that the waste glass powder would enhance its the compressive strength and improve its the thermal insulation performance. Correlation study between contents of the added waste glass powder in geothermal cements and its mechanic and thermal property was conducted. It was found that thermal insulation cement exhibited its optimum performance when the added content of glass powers was 20% in weight. Analysis of the microstructure porosity with SEM found that the pores in thermal insulation cement with added waste glass powders were mostly closed, tiny and even, and therefore contributed to the compressive strength of the thermal insulation cement; such pores would be also beneficial to improving its thermal insulation performance.

Steel slag and waste clay bricks are two prevalent solid waste materials generated during industrial production. The complex chemical compositions of these materials present challenges to their utilization in conventional alumina silicate ceramics manufacturing. A new type of ceramic tile, which utilizes steel slag and waste clay brick as raw materials, has been successfully developed in order to effectively utilize these solid wastes. The optimal composition of the ceramic material was determined through orthogonal experimentation, during which the effects of the sample molding pressure, the soaking time, and the sintering temperature on the ceramic properties were studied. The results show that the optimal ceramic tile formula was 45% steel slag, 35% waste clay bricks, and 25% talc. The optimal process parameters for this composition included a molding pressure of 25 MPa, a sintering temperature of 1190 °C, and a soaking time of 60 min. The prepared ceramic tile samples had compositions in which solid waste accounted for more than 76% of the total material. Additionally, they possessed a modulus of rupture of more than 73.2 MPa and a corresponding water absorption rate of less than 0.05%.

Abstract Background Maternal obesity is a global issue that has devastating effects across the reproductive spectrum such as meiotic defects in oocytes, consequently worsening pregnancy outcomes. Different studies have shown that such types of meiotic defects originated from the oocytes of obese mothers. Thus, there is an urgent need to develop strategies to reduce the incidence of obesity-related oocyte defects that adversely affect pregnancy outcomes. Multiple growth factors have been identified as directly associated with female reproduction; however, the impact of various growth factors on female fertility in response to obesity remains poorly understood. Methods The immature GV-stage oocytes from HFD female mice were collected and cultured in vitro in two different groups (HFD oocytes with and without 50 nM IGF2), however; the oocytes from ND mice were used as a positive control. HFD oocytes treated with or without IGF2 were further used to observe the meiotic structure using different analysis including, the spindle and chromosomal analysis, reactive oxygen species levels, mitochondrial functional activities, and early apoptotic index using immunofluorescence. Additionally, the embryonic developmental competency and embryos quality of IGF2-treated zygotes were also determined. Results In our findings, we observed significantly reduced contents of insulin-like growth factor 2 (IGF2) in the serum and oocytes of obese mice. Our data indicated supplementation of IGF2 in a culture medium improves the blastocyst formation: from 46% in the HFD group to 61% in the HFD + IGF2-treatment group (50 nM IGF2). Moreover, adding IGF2 to the culture medium reduces the reactive oxygen species index and alleviates the frequency of spindle/chromosome defects. We found increased mitochondrial functional activity in oocytes from obese mice after treating the oocytes with IGF2: observed elevated level of adenosine triphosphate, increased mitochondrial distribution, higher mitochondrial membrane potentials, and reduced mitochondrial ultrastructure defects. Furthermore, IGF2 administration also increases the overall protein synthesis and decreases the apoptotic index in oocytes from obese mice. Conclusions Collectively, our findings are strongly in favor of adding IGF2 in culture medium to overcome obesity-related meiotic structural-developmental defects by helping ameliorate the known sub-optimal culturing conditions that are currently standard with assisted reproduction technologies.

Objective: To report two cases of congenital myasthenic syndromes (CMS) in a Chinese family with mutations in the COLQ gene and to prove the consequence defect of the ColQ protein. Method: Clinical characteristics of the two children from the same family were described. Next-generation sequencing (NGS) and sanger sequencing was performed on the proband and family members. The consequence of the mutation was predicted by 3D protein structure prediction using I-TASSER. The wild type and mutant were transfected to 293T cells, and ColQ protein was detected by Western Blot. Results: The diagnosis of CMS was based on a symptom combination of fatigable muscle weakness, ptosis, scoliosis, and hypotonia, aggravation of muscle weakness after the neostigmine test, and a 46% decrement in repetitive nerve stimulation. A muscle biopsy was performed on the proband, revealing mild variation in the myofiber size. NGS data revealed two compound heterozygous mutations at c.173delC (p.Pro58Hisfs*22) and c.C706T (p.R236X) in the COLQ gene, where the former was a novel mutation. A 3D structure prediction showed two truncated ColQ proteins with 78aa and 235aa, respectively. The truncated ColQ protein was proved in 293T cells transfected with c.173delC or c.C706T mutants by Western Blot. Conclusions: The mutations of c.173delC and c.C706T in the COLQ gene led to truncated ColQ protein and contributed to the pathogenesis of CMS in this Chinese family.

Abstract Jumbo phages are a group of tailed bacteriophages with large genomes and capsids. As a prototype of jumbo phage, ΦKZ infects Pseudomonas aeruginosa, a multi-drug-resistant (MDR) opportunistic pathogen leading to acute or chronic infection in immunocompromised individuals. It holds potential to be used as an antimicrobial agent and as a model for uncovering basic phage biology. Although previous low-resolution structural studies have indicated that jumbo phages may have more complicated capsid structures than smaller phages such as HK97, the detailed structures and the assembly mechanism of their capsids remain largely unknown. Here, we report a 3.5-Å-resolution cryo-EM structure of the ΦKZ capsid. The structure unveiled ten minor capsid proteins, with some decorating the outer surface of the capsid and the others forming a complex network attached to the capsid’s inner surface. This network seems to play roles in driving capsid assembly and capsid stabilization. Similar mechanisms of capsid assembly and stabilization are probably employed by many other jumbo viruses.

ABSTRACT Return of crop residues directly as straw, animal manure, or biochar are recommended management options for biowaste recycling and soil organic carbon (SOC) maintenance in agriculture. However, to address the soil health challenges associated with soil degradation and climate change, it is critical to determine if or which of these different forms of crop residues could deliver a synergic improvement in SOC storage, emission reduction, and crop productivity following field application. In this study, maize straw in the form of air‐dried biomass (CS), manure via cattle digestion (CM), and biochar via pyrolysis (CB) was respectively amended once at a dose of 10 t C ha−1, in comparison to no maize straw addition (CK), in a paddy field under rice‐wheat rotation. Changes in soil properties, SOC storage, greenhouse gas (GHG) emissions, and rice/wheat yield were examined over two consecutive rice/wheat rotation cycles following soil amendment. The total rice grain yield considerably increased by 6% under CM and CB, while it reduced by 6% under CS compared to CK. Soil nutrient content persistently increased under CM and CB by 4.2% ~ 17% and 11% ~ 26% for total nitrogen, 26% ~ 61% and 20% ~ 53% for available P, and 2% ~ 82% and 30% ~ 115% for available K, respectively. Topsoil SOC storage increased considerably by 8% under CM and 20% under CB, while remained unchanged under CS, compared to CK. The total methane (CH4) and nitrous oxide (N2O) emissions were considerably increased by 7 folds and 15% under CS and 3.5 folds and 61% under CM, respectively, compared to CK. In contrast, these emissions considerably decreased under CB by 33% for CH4 and 29% for N2O. Consequently, the C emission efficiency considerably reduced under CS and CM but increased under CB over the two rotation cycles monitored. Moreover, the soil quality index (SQI) considerably improved under CM and CB but remained unchanged under CS compared to CK. Among the different forms of straw return, manure, and biochar, straw amendments differed considerably in their effects on C sequestration, GHG emissions, and crop productivity. Only biochar from crop residues synergistically improved these functions in the short‐term following application to paddy soil.

BackgroundUterine leiomyosarcoma (uLMS) accounts for roughly 70% of all uterine sarcomas, with recurrence and mortality rates notably higher than those of other uterine tumors. The prognosis of uLMS patients who have distant metastases remains poor. The objective of this study was to determine independent risk variables related to distant metastases in patients with uLMS and prognostic factors for those with distant metastases. Subsequently, two practical nomograms were developed and validated to assess the probability of distant metastases and predict survival outcomes for these with distant metastases, respectively.MethodsA real-world retrospective study was carried out using data from patients diagnosed with primary uLMS in the Surveillance, Epidemiology, and End Results (SEER) database spanning the years 2010 to 2015. Univariate and multivariate logistic regression analyses were utilized to identify clinicopathological characteristics related to the risk of distant metastases, while univariate and multivariate Cox regressions were employed to determine prognostic factors. Then, a risk nomogram incorporating independent risk variables and a prognostic nomogram integrating independent prognostic factors were established in the training cohort and validated for accuracy in the validation cohort, respectively. Receiver operating characteristic (ROC) curves, area under the curve (AUC), and calibration curves were utilized to measure the accuracy of nomograms, while decision curve analysis (DCA) curves were employed to assess their clinical benefit capacity. Based on the median total point derived from the prognostic nomogram, patients were stratified into high- and low-risk groups. The differentiation ability of the prognostic nomogram was evaluated using Kaplan-Meier survival analysis with the log-rank test.ResultsThe study encompassed 1,362 patients diagnosed with uLMS, among whom 337 cases (24.7%) manifested synchronous distant metastases at the initial diagnosis. Univariate and multivariate logistic regression analyses identified race, histological grade, T stage, N stage, tumor size, surgery, and chemotherapy as independent risk factors for distant metastases in uLMS patients. The outcomes of both univariate and multivariate Cox analyses indicated that surgery and chemotherapy emerged as independent protective factors for prognosis in uLMS patients with distant metastases, whereas higher histological grade and T stage were identified as independent risk factors. The risk nomogram incorporating independent risk variables and the prognostic nomogram integrating independent prognostic factors could respectively predict the risk of metastases and the prognosis very effectively in both training and validation cohorts.ConclusionsIn summary, we developed the novel well-validated risk nomogram to precisely assess the probability of metastases in uLMS patients and prognostic nomogram to predict the prognosis of those with distant metastases, providing decision-making guidance for tailoring individualized clinical management of these patients.

Asphaltene, the heaviest and most polar non-hydrocarbon component in crude oil, may interact with waxes and affect the flow and gelation behavior of waxy oils. To further study the effect of asphaltene on the flow and gelation behavior of waxy oils, five wax-containing simulated oils with small dosage asphaltene content were prepared. Through pour point and rheometer test, it is found that asphaltenes can improve the low-temperature rheology of waxy oil. There is no critical turning point above which the low-temperature flowability improved. With an increase in asphaltene content from 0 wt% to 0.1 wt%, notable changes were observed in the properties of the waxy oil. The pour point, which measures the temperature at which the oil becomes too viscous to flow freely, exhibited a decrease from 25 ℃ to 13 ℃. Similarly, the gelation temperature, indicating the temperature at which the oil starts forming a gel-like consistency, also decreased from 29.0 ℃ to 27.1 ℃. These modifications can be attributed to the presence of asphaltene in the oil sample. This outcome can be attributed to the interference caused by the presence of asphaltenes, which disrupts the gel network structure of the waxy oil and consequently hinders its gelation process. Simultaneously, within the low asphaltene content range, an increase in asphaltene content resulted in a considerable decrease in the viscosity of the waxy oil at 10 °C, reducing it from 531.5 mPa s to 14 mPa s.

Abstract Traditional warehousing typically needs machine learning or manual tagging to classify objects. However, this method is less robust and consumes a lot of labour and material resources. Based on DenseNet, this work proposes a feature weighting convolutional network recognition model and designs a set of software and hardware for data acquisition, which is applied to the efficient classification of industrial parts in warehouse management. Firstly, this work modifies DenseNet by embedding SE‐Block, and replaces the cross‐entropy loss function with the focus loss function to optimize the model structure. Secondly, a multi‐view hardware and software acquisition system is designed to complete the functions of part image acquisition, image preprocessing, model training and part recognition. Finally, an industrial parts sorting experiment was designed. Compared with the original DenseNet model, the proposed weighted convolutional network identification model showed that the accuracy of the modified model was increased by 3.09% and the convergence rate was significantly improved. The modified model proposed in this work aims to improve the recognition accuracy of industrial parts in modern warehouse management, so as to modify the classification efficiency of warehouse parts in production.

As an important part of urban terminal delivery, automated guided vehicles (AGVs) have been widely used in the field of takeout delivery. Due to the real-time generation of takeout orders, the delivery system is required to be extremely dynamic, so the AGV needs to be dynamically scheduled. At the same time, the uncertainty in the delivery process (such as the meal preparation time) further increases the complexity and difficulty of AGV scheduling. Considering the influence of these two factors, the method of embedding a stochastic programming model into a rolling mechanism is adopted to optimize the AGV delivery routing. Specifically, to handle real-time orders under dynamic demand, an optimization mechanism based on a rolling scheduling framework is proposed, which allows the AGV’s route to be continuously updated. Unlike most VRP models, an open chain structure is used to describe the dynamic delivery path of AGVs. In order to deal with the impact of uncertain meal preparation time on route planning, a stochastic programming model is formulated with the purpose of minimizing the expected order timeout rate and the total customer waiting time. In addition, an effective path merging strategy and after-effects strategy are also considered in the model. In order to solve the proposed mathematical programming model, a multi-objective optimization algorithm based on a NSGA-III framework is developed. Finally, a series of experimental results demonstrate the effectiveness and superiority of the proposed model and algorithm.

Background Schisandra sphenanthera Rehd. et Wils. is a plant used in traditional Chinese medicine (TCM). However, great differences exist in the content of active secondary metabolites in various parts of S. sphenanthera. Do microorganisms critically influence the accumulation of active components in different parts of S. sphenanthera? Methods In this study, 16S/ITS amplicon sequencing analysis was applied to unravel microbial communities in rhizospheric soil and different parts of wild S. sphenanthera. At the same time, the active secondary metabolites in different parts were detected, and the correlation between the secondary metabolites and microorganisms was analyzed. Results The major components identified in the essential oils were sesquiterpene and oxygenated sesquiterpenes. The contents of essential oil components in fruit were much higher than that in stem and leaf, and the dominant essential oil components were different in these parts. The dominant components of the three parts were γ-muurolene, δ-cadinol, and trans farnesol (stem); α-cadinol and neoisolongifolene-8-ol (leaf); isosapathulenol, α-santalol, cedrenol, and longiverbenone (fruit). The microbial amplicon sequences were taxonomically grouped into eight (bacteria) and seven (fungi) different phyla. Community diversity and composition analyses showed that different parts of S. sphenanthera had similar and unique microbial communities, and functional prediction analysis showed that the main functions of microorganisms were related to metabolism. Moreover, the accumulation of secondary metabolites in S. sphenanthera was closely related to the microbial community composition, especially bacteria. In endophytic bacteria, Staphylococcus and Hypomicrobium had negative effects on five secondary metabolites, among which γ-muurolene and trans farnesol were the dominant components in the stem. That is, the dominant components in stems were greatly affected by microorganisms. Our results provided a new opportunity to further understand the effects of microorganisms on the active secondary metabolites and provided a basis for further research on the sustainable utilization of S. sphenanthera.

Schisandra sphenanthera Rehd. et Wils., as a traditional Chinese medicine, has important medicinal value. In the market, the availability of the fruit of S. sphenanthera mainly relies on wild picking, but many canes and leaves are discarded during wild collection, resulting in a waste of resources. The canes and leaves of S. sphenanthera contain various bioactive ingredients and can be used as spice, tea, and medicine and so present great utilization opportunities. Therefore, it is helpful to explore the effective components and biological activities of the canes and leaves to utilize S. sphenanthera fully. In this study, the response surface method with ultrasound was used to extract the total triterpenoids from the canes and leaves of S. sphenanthera at different stages. The content of total triterpenoids in the leaves at different stages was higher than that in the canes. The total triterpenoids in the canes and leaves had strong antioxidant and antibacterial abilities. At the same time, the antibacterial activity of the total triterpenoids against Bacillus subtilis and Pseudomonas aeruginosa was stronger than that against Staphylococcus aureus and Escherichia coli. This study provides the foundation for the development and utilization of the canes and leaves that would relieve the shortage of fruit resources of S. sphenanthera.

Generalized target detection algorithms perform well for large- and medium-sized targets but struggle with small ones. However, with the growing importance of aerial images in urban transportation and environmental monitoring, detecting small targets in such imagery has been a promising research hotspot. The challenge in small object detection lies in the limited pixel proportion and the complexity of feature extraction. Moreover, current mainstream detection algorithms tend to be overly complex, leading to structural redundancy for small objects. To cope with these challenges, this paper recommends the PCSG model based on yolov5, which optimizes both the detection head and backbone networks. (1) An enhanced detection header is introduced, featuring a new structure that enhances the feature pyramid network and the path aggregation network. This enhancement bolsters the model’s shallow feature reuse capability and introduces a dedicated detection layer for smaller objects. Additionally, redundant structures in the network are pruned, and the lightweight and versatile upsampling operator CARAFE is used to optimize the upsampling algorithm. (2) The paper proposes the module named SPD-Conv to replace the strided convolution operation and pooling structures in yolov5, thereby enhancing the backbone’s feature extraction capability. Furthermore, Ghost convolution is utilized to optimize the parameter count, ensuring that the backbone meets the real-time needs of aerial image detection. The experimental results from the RSOD dataset show that the PCSG model exhibits superior detection performance. The value of mAP increases from 97.1% to 97.8%, while the number of model parameters decreases by 22.3%, from 1,761,871 to 1,368,823. These findings unequivocally highlight the effectiveness of this approach.

Trust plays a crucial role in effectively responding to public health emergencies. Drawing on COVID-19 survey data conducted in Hubei, China, during August 2020 with a sample size of 5494, this study investigated the influence of individuals’ socioeconomic status on trust in acquaintances, strangers and institutions, and how this relationship is moderated by epidemic prevention, policy perception and family structure. The findings showed that individuals with higher socioeconomic status tend to have higher levels of trust. Those with higher income but being married demonstrate higher trust. When perceiving epidemic prevention policies as stringent, those with higher income display increased trust in acquaintances and institutions; similarly, those with lower education levels exhibit heightened trust in acquaintances and strangers. Individuals working in social organizations express higher trust in strangers; however, their trust is compromised under stringent epidemic prevention policies due to potentially heavier work burdens.

Collaborative robots face barriers to widespread adoption due to the complexity of programming them to achieve human-like movement. Learning from demonstration (LfD) has emerged as a crucial solution, allowing robots to learn tasks directly from expert demonstrations, offering versatility and an intuitive programming approach. However, many existing LfD methods encounter issues such as convergence failure and lack of generalization ability. In this paper, we propose: (1) a generative adversarial network (GAN)-based model with multilayer perceptron (MLP) architecture, coupled with a novel loss function designed to mitigate convergence issues; (2) an affine transformation-based generalization method aimed at enhancing LfD tasks by improving their generalization performance; (3) a data preprocessing method tailored to facilitate deployment on robotics platforms. We conduct experiments on a UR5 robotic platform tasked with handwritten digit recognition. Our results demonstrate that our proposed method significantly accelerates generation speed, achieving a remarkable processing time of 23 ms, which is five times faster than movement primitives (MPs), while preserving key features from demonstrations. This leads to outstanding convergence and generalization performance.

Abstract Chronic hypoxia leads to irreversible cognitive impairment, primarily due to hippocampal neurodegeneration, for which the underlying mechanism remains poorly understood. We administered hypoxia (13%) to C57BL mice for 1–14 days in this study. Chronic hypoxia for 7 or 14 d, but not 1 or 3 d, resulted in alpha-synuclein hyperphosphorylation at serine129 (α-Syn p-S129) and protein aggregation, hippocampal neurodegeneration, and cognitive deficits, whereas the latter could be prevented by alpha-synuclein knockdown or an administered short peptide competing at α-Syn S129. These results suggest that α-Syn p-S129 mediates hippocampal degeneration and cognitive impairment following chronic hypoxia. Furthermore, we found that chronic hypoxia enhanced ceramide catabolism by inducing hypoxia-inducible factor (HIF)-2α and HIF-2α-dependent transcriptional activation of alkaline ceramidase 2 (Acer2). Thus, the enzymatic activity of protein phosphatase 2A (PP2A), a specific phosphatase for α-syn, is inhibited, leading to the sustained induction of α-Syn p-S129. Finally, we found that intermittent hypoxic preconditioning protected against subsequent chronic hypoxia-induced hippocampal neurodegeneration and cognitive impairment by preventing α-Syn p-S129. These results proved the critical role of α-syn pathology in chronic hypoxia-afforded cognitive impairment and revealed a novel mechanism underlying α-syn hyperphosphorylation during chronic hypoxia. The findings bear implications in developing novel therapeutic interventions for chronic hypoxia-related brain disorders.

Giant viruses are large DNA viruses with capsid diameters up to 500 nm. Given technical challenges only few high-resolution structures of viral capsids exist. Here, Shao et al. provide a nearatomic structure of giant virus PBCV-1 capsid and resolve the previously unknown asymmetric capsid components. The local capsid microenvironments created by these components provide insights into the mechanism of capsid assembly of giant viruses.

Methane (CH4) is the main pollutant in oil and gas production. The detection and accounting of CH4 is an important issue in the process of greenhouse gas control and emission reduction in oil and gas industry. In this study, a portable CH4 detector based on tunable diode laser absorption spectroscopy (TDLAS) technology was deployed. The three-dimensional distribution of CH4 in a natural gas purification plant in Sichuan was obtained through vertical unmanned aerial vehicle (UAV) flight observations and ground mobile observations. According to the mass balance method, the emission of CH4 on 30 m above ground level (AGL) and 60 m AGL in this site was about 0.012 kg/s (±42% at 1σ) and 0.034 kg/s (±47% at 1σ), respectively, in one day. The vertical distribution showed that the CH4 concentration reached the maximum (2.75 ± 0.19 ppm) with height of 0 to 100 m AGL. The CH4 concentration from 100 to 300 m AGL showed a downward trend with height. Atmospheric instability at high altitude and high wind speed promoted the diffusion of CH4. The CH4 concentrations of horizontal distribution on 30 m AGL and 60 m AGL were 2.48 ± 0.11 ppm and 2.76 ± 0.34 ppm. In the observation of mobile campaigns, the connecting equipment of natural gas treatment facilities was prone to leakage, such as in valves and flanges. CH4 leakage was also detected at the torch mouth, especially when there was an open flame at the torch mouth. During the mobile movement investigation, the downwind measurement (OTM-33A) was applied to determine the overall CH4 emission rate shortly after patrolling the site. This work plays a vital role in optimizing the operation and maintenance of natural gas production stations pipe network, ensuring human safety and minimizing greenhouse gas emissions.

Compared with the international meteor surveillance systems, the ground wide angle camera (GWAC) system exhibits characteristics such as images with the resolution of 4K × 4K and single-site observation. These characteristics present challenges for meteor detection in the GWAC system. Consequently, this paper proposes a new meteor detection algorithm for the GWAC system on the base of the solely mini-GWAC system data algorithm. The new algorithm consists of the following key steps: (1) to compare differences between adjacent frames, applying block-based image binarization thresholds, and incorporating median filtering to reduce noise; (2) to adopt the probabilistic Hough transform (PHT) to identify moving objects and cluster them based on the origin moment of the line segments, while assessing the credibility of clustering; (3) to introduce the so-called maximum disappearance frame for moving objects in the tracking algorithm, enhancing the ability to track multi-frame moving objects. The utilization of the line segment inclination angle of the moving object as the direction of movement facilitates the tracking of multiple moving objects, thereby reducing the probability of mistakenly selecting single-frame moving objects; (4) to leverage the light curves of single-frame moving objects to select meteors to enhance the accuracy of meteor detection. Comparative experiments demonstrate that our proposed algorithm processes each frame image in just 0.39 s, achieving an accuracy of 89.8% in the dataset of 5856 adjacent frames. The experimental results indicate that the algorithm achieved an accuracy of 90.27% when applied in the meteor detection of the image data captured by the GWAC system from Dec. 10th to 19th in 2019 and 2021, obtaining excellent detection results.

Mechanism parameters of bipedal robots are crucial for achieving efficient locomotion in complex environments. Inspired by the human energy-efficient walking style, this paper proposes a novel concept of full-range walking energy efficiency and explores the optimal linkage mechanism within certain ranges of step length and walking speed for bipedal robots. First, a bipedal model incorporating an upper body is established for dynamic analysis. Next, an optimal walking gait subject to walking constraints is solved by considering the full-range energy efficiency. Further, an optimal linkage mechanism is investigated, and the influence of dynamic parameters on energy efficiency is analyzed. Finally, the push-off impulse, minimum ground support force, and walking torque features are discussed. It shows that the full-range walking energy efficiency can be lowered by reducing the ratio of leg mass, concentrating mass at the hip joint, decreasing the length of the upper body, or increasing the center of mass of the leg. In addition, efficient walking motion can be achieved by designing the coordination of positive hip joint torque and push-off impulse at the ankle. This paper can be used to guide the mechanism parameter optimization and efficient walking gait design of bipedal robots.

Objective: To identify suitable reference genes for gene expression studies in rat dorsal root ganglia (DRG) neurons. Methods: The raw cycle threshold (Ct) values of 12 selected reference genes were obtained via quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) in neurons at different developmental stages or under different treatments. Two strategies were employed to screen the most stable reference genes: the genes were ranked according to the coefficient of biological variation and further validated using geNorm and NormFinder programs. The stable and unstable reference genes were subsequently used as internal controls to assess their effects on target gene expression. Results: All reference genes showed varying degrees of fluctuation in Ct values during the growth process of neurons or after different treatments. 18S ribosomal RNA (Rn18s) and β-actin (Actb) exhibited the most significant changes, while ubiquitin C (Ubc), hypoxanthine phosphoribosyl transferase (Hprt), and mitochondrial ribosomal protein L10 (Mrpl10) showed relatively minor changes. The most stable and unstable genes obtained by different evaluation methods varied slightly. Overall, Actb was found to be the most unstable reference gene, while Hprt was the relatively most stable reference gene. The use of unstable reference genes Actb and ankyrin repeat domain 27 (Ankrd27) as internal controls led to high variability within the control group, ultimately affecting the determination of target gene expression. In contrast, the stable reference gene Hprt had small inter-assay variation and high stability. Conclusions: Our observations indicate that Hprt is a proper endogenous reference gene for qRT-PCR analysis in rat DRG neurons and thus provides a critical molecular basis for the genetic characterization in neurological disorders.

Currently, traffic-related sources are considered to be one of the major contributors to air pollutants in urban areas. As the number of motor vehicles increases, the impact of traffic-related air pollutants (TRAPs) on human health has also increased in recent years. People are easily exposed to TRAPs in their daily lives. However, long-term exposure to TRAPs can have adverse health effects. Mobile monitoring is more flexible compared to traditional urban monitoring stations and can effectively obtain the spatial variation characteristics of air pollutants. We mounted a sensor package on an electric bicycle and conducted mobile measurements of CO, NO2 and SO2 on a circular road in the center of Shaoxing, a city in the center of the Yangtze Delta, China. The CO, NO2 and SO2 concentrations were observed to be higher in the morning and evening rush hours, and the three pollutants show different seasonal and spatial variation characteristics. CO concentration was higher in urban arterial and crossroads. NO2 concentration was variable, alternating between high and low concentrations. SO2 concentration was relatively stable and aggregated. This study provides important information on the spatial and temporal variations of TRAPs, which helps commuters understand how to effectively reduce pollutant exposure during personal travel.

Conjugated microporous polymers (CMPs), as a kind of two-dimensional material, have attracted extensive attention due to their advantages in visible light–driven photocatalytic splitting of water for hydrogen evolution. However, improving the microstructure and electronic structure of the material to enhance their photocatalytic performance for hydrogen evolution remains a challenge. We designed and reported two analogous CMPs including CMP-1 and CMP-2 that contain triazine and dibenzothiophene-S,S-dioxide units, which were prepared by Pd-catalyzed Suzuki-Miyaura coupling reaction. The main difference of two CMPs is that the triazine units are connected to benzene unit (CMP-1) or thiophene unit (CMP-2). Both of the CMPs exhibit excellent light capture capability, and compared with CMP-2, CMP-1 has faster separation rates and lower recombination rates for the charge carriers (electron/hole), and then, a higher hydrogen evolution rate was obtained from water decomposition reaction. We find the H2 production rate of CMP-1 can be up to 9,698.53 μmol g−1h −1, which is about twice of that of CMP-2. This work suggests that molecular design is a potent method to optimize the photocatalytic performance toward hydrogen evolution of the CMPs.

Bacteriophage (phage) T4 has served as an extraordinary model to elucidate biological structures and mechanisms. Recent discoveries on the T4 head (capsid) structure, portal vertex, and genome packaging add a significant body of new literature to phage biology. Head structures in unexpanded and expanded conformations show dramatic domain movements, structural remodeling, and a ~70% increase in inner volume while creating high-affinity binding sites for the outer decoration proteins Soc and Hoc. Small changes in intercapsomer interactions modulate angles between capsomer planes, leading to profound alterations in head length. The in situ cryo-EM structure of the symmetry-mismatched portal vertex shows the remarkable structural morphing of local regions of the portal protein, allowing similar interactions with the capsid protein in different structural environments. Conformational changes in these interactions trigger the structural remodeling of capsid protein subunits surrounding the portal vertex, which propagate as a wave of expansion throughout the capsid. A second symmetry mismatch is created when a pentameric packaging motor assembles at the outer “clip” domains of the dodecameric portal vertex. The single-molecule dynamics of the packaging machine suggests a continuous burst mechanism in which the motor subunits adjusted to the shape of the DNA fire ATP hydrolysis, generating speeds as high as 2000 bp/s.

3CLpro is a key proteinase for SARS-CoV-2 replication and serves as an important target for antiviral drug development. However, how its activity is regulated intracellularly is still obscure. In this study, we developed a 3CLpro protease activity reporter system to examine the impact of various factors, including nutrient supplements, ions, pHs, or oxidative stress inducers, on 3CLpro protease activity. We found that oxidative stress could increase the overall activity of 3CLpro. Not altering the expression, oxidative stress decreased the solubility of 3CLpro in the lysis buffer containing 1% Triton-X-100. The Triton-X-100-insoluble 3CLpro was correlated with aggregates’ formation and responsible for the increased enzymatic activity. The disulfide bonds formed between Cys85 sites of 3CLpro protomers account for the insolubility and the aggregation of 3CLpro. Besides being regulated by oxidative stress, 3CLpro impaired the cellular antioxidant capacity by regulating the cleavage of GPx1 at its N-terminus. This cleavage could further elevate the 3CLpro-proximate oxidative activity, favor aggregation and activation of 3CLpro, and thus lead to a positive feedback loop. In summary, we reported that oxidative stress transforms 3CLpro into a detergent-insoluble form that is more enzymatically active, leading to increased viral replication/transcription. Our study provided mechanistic evidence that suggests the therapeutic potential of antioxidants in the clinical treatment of COVID-19 patients.

Patients with human papillomavirus (HPV) negative oral squamous cell carcinoma (OSCC) generally have poor clinical outcomes and worse responses to radiotherapy. It is urgent to explore the underlining mechanisms of the distinct prognoses between HPV negative and HPV positive OSCC and to develop effective therapy strategy to increase the survival rate of HPV negative OSCC patients. We conducted a retrospective cohort of 99 resected OSCC patients to evaluate the prognosis of HPV negative and HPV positive OSCC patients receiving radiation or not. We further addressed the association of CD68+ macrophage infiltration with HPV status and the effects on survival of OSCC patients. We also used the TCGA-OSCC cohort for further verification. Based on the cohort study, we applied a synthetic dsRNA polymer, polyriboinosinic-polyribocytidylic acid (poly(I:C)), on CAL-27 (HPV negative OSCC cells). We co-cultured its condition medium with THP-1 derived macrophage and examined the cytokines and macrophage migration. We found that high CD68+ macrophage infiltration associated with poor overall survival in HPV negative OSCC patients receiving radiation. In vitro, poly(I:C) could induce apoptosis and enhance the radiosensitivity, but increase macrophage recruitment. Targeting HMGB1 could inhibit IL-6 induction and macrophage recruitment. Our findings indicated that CD68+ macrophage might play an important role in the outcomes of HPV negative OSCC patients receiving radiation. Our findings also suggested that radiation combined poly(I:C) might be a potential therapy strategy to increase the radiation response and prognosis of HPV negative OSCC. Notably, HMGB1 should be targeted to inhibit macrophage recruitment and enhance overall therapy effects.

Hypoxic stress occurs in various physiological and pathological states, such as aging, disease, or high-altitude exposure, all of which pose a challenge to many organs in the body, necessitating adaptation. However, the exact mechanisms by which hypoxia affects advanced brain function (learning and memory skills in particular) remain unclear. In this study, we investigated the effects of hypoxic stress on hippocampal function. Specifically, we studied the effects of the dysfunction of mitochondrial oxidative phosphorylation using global proteomics. First, we found that hypoxic stress impaired cognitive and motor abilities, whereas it caused no substantial changes in the brain morphology or structure of mice. Second, bioinformatics analysis indicated that hypoxia affected the expression of 516 proteins, of which 71.1% were upregulated and 28.5% were downregulated. We demonstrated that mitochondrial function was altered and manifested as a decrease in NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 4 expression, accompanied by increased reactive oxygen species generation, resulting in further neuronal injury. These results may provide some new insights into how hypoxic stress alters hippocampal function via the dysfunction of mitochondrial oxidative phosphorylation.

An ultrathin 2D Ti3C2/g-C3N4 MXene (2D-TC/CN) heterojunction was synthesized, using a facile self-assembly method; the perfect microscopic-morphology and the lattice structure presented in the sample with a 2 wt% content of Ti3C2 were observed by the field-emission scanning electron microscopy (SEM) and transmission electron microscope (TEM). The optimized sample (2-TC/CN) exhibited excellent performance in degrading the tetracycline (TC), and the degradation rate reached 93.93% in the conditions of 20 mg/L, 50 mL of tetracycline within 60 min. Except for the increased specific-surface area, investigated by UV-vis diffuse reflectance spectra (UV-vis DRS) and X-ray photoelectron microscopy (XPS) valence spectra, the significantly enhanced photocatalytic activity of the 2-TC/CN could also be ascribed to the formation of Ti-N bonds between Ti3C2 and g-C3N4 nanosheets, which reduced the width of the band gap through adjusting the position of the valence band, thus resulting in the broadened light-absorption. Furthermore, the facilitated electron transmission was also proved by time-resolved photoluminescence (TRPL) and electrochemical impedance spectroscopy (EIS), which is effective in improving the quantum efficiency of photo-generated electrons. In addition, the resulting radical-capture experiment suggested that superoxide radicals have the greatest influence on photodegradation performance, with the photodegradation rate of TC reducing from 93.16% to 32.08% after the capture of superoxide radicals, which can be attributed to the production of superoxide radicals only, by the 2-TC/CN composites with a high conduction-band value (−0.62 eV). These facilely designed 2D Ti3C2/g-C3N4 composites possess great application potential for the photodegradation of tetracycline and other antibiotics.

A novel phosphorous-containing acrylated epoxidized soybean oil-based (P-AESO) resin was developed via the ring-opening reaction of epoxidized soybean oil (ESO) with diphenylphosphinic chloride (DPPC), followed by acrylation of the resulting groups. The chemical structure was characterized by Fourier transform infrared spectroscopy (FT-IR), and 1H nuclear magnetic resonance (1H NMR). Subsequently, the viscosity and volumetric shrinkage of the obtained P-AESO resins were studied. Then the oligomer was formulated into UV-curable coatings, and the mechanical, thermal, and coating properties of the resulting UV-cured bioresins were studied by tensile testing, dynamic mechanical thermal analysis (DMA), thermogravimetric analysis (TGA) coupled with FT-IR spectroscopy (TGA-FT-IR), hardness, adhesion, pencil hardness and chemical resistance. Furthermore, the UV-curing behavior of the P-AESO resin was determined by real-time realtime infrared (RT-IR). Meanwhile, compared with coating from acrylated epoxidized soybean oil (AESO), the P-AESO system coatings showed better volumetric shrinkage, excellent adhesion, and enhanced thermal and glass transition temperature (Tg) while maintaining reasonably final C=C conversions and cross-link density. For instance, the obtained P-AESO/trimethylolpropanetriacrylate (TMPTA) 20 material possessed a volumetric shrinkage of 4.1%, Tg of 115.6°C, char yield of 9.47%, and final C=C conversions of 81.4% respectively, which exhibited superior values than that of the AESO/TMPTA20 material. The improvement of the P-AESO coating performances could contribute to the architectures that combined the structural features of phosphorous-containing rigid benzene. The developed P-AESO resin is promising for applications in the UV-curable coatings.

Abstract Background Glioblastoma (GBM) is a fatal brain tumor, lacking effective treatment. Epidermal growth factor receptor (EGFR) is recognized as an attractive target for GBM treatment. However, GBMs have very poor responses to the first- and second-generation EGFR inhibitors. The third-generation EGFR-targeted drug, AZD9291, is a novel and irreversible inhibitor. It is noteworthy that AZD9291 shows excellent blood–brain barrier penetration and has potential for the treatment of brain tumors. Methods In this study, we evaluated the anti-tumor activity and effectiveness of AZD9291 in a preclinical GBM model. Results AZD9291 showed dose-responsive growth inhibitory activity against six GBM cell lines. Importantly, AZD9291 inhibited GBM cell proliferation > 10 times more efficiently than the first-generation EGFR inhibitors. AZD9291 induced GBM cell cycle arrest and significantly inhibited colony formation, migration, and invasion of GBM cells. In an orthotopic GBM model, AZD9291 treatment significantly inhibited tumor survival and prolonged animal survival. The underlying anti-GBM mechanism of AZD9291 was shown to be different from that of the first-generation EGFR inhibitors. In contrast to erlotinib, AZD9291 continuously and efficiently inhibited the EGFR/ERK signaling in GBM cells. Conclusion AZD9291 demonstrated an efficient preclinical activity in GBM in vitro and in vivo models. AZD9291 has been approved for the treatment of lung cancer with good safety and tolerability. Our results support the possibility of conducting clinical trials of anti-GBM therapy using AZD9291.

As a type of non-coding RNA of more than 200 nucleotides, long non-coding RNAs(lncRNAs) lack protein coding ability and can regulate gene expression. MicroRNAs(miRNAs), which are also non-coding RNAs, are short single-stranded RNAs, usually composed of 18–23 nucleotides. MiRNAs inhibits gene expression by specifically binding to the 3′-UTR of downstream target mRNAs and can function as oncogenes or suppressor oncogenes to regulate the occurrence and development of cancer. LncRNAs can function as competitive endogenous RNAs that bind to miRNAs, resulting in the recovery of downstream mRNA expression and activity. The regulatory network existing between lncRNAs, miRNAs and mRNAs regulates a variety of biological processes, including cell proliferation, apoptosis, migration and invasion as well as cell-cycle arrest. Disruption of the ceRNA network affects cell growth and development and often leads to various diseases, especially cancer. The lncRNA MALAT1, which is located on chromosome 11q13, contains more than 8000 nucleotides and is implicated in the occurrence and development of many cancers. Here, we review the impact of the ceRNA network and the lncRNA MALAT1 in cancer.

Mosquito viruses cause unpredictable outbreaks of disease. Recently, several unassigned viruses isolated from mosquitoes, including the Omono River virus (OmRV), were identified as totivirus-like viruses, with features similar to those of the Totiviridae family. Most reported members of this family infect fungi or protozoans and lack an extracellular life cycle stage. Here, we identified a new strain of OmRV and determined high-resolution structures for this virus using single-particle cryo-electron microscopy. The structures feature an unexpected protrusion at the five-fold vertex of the capsid. Disassociation of the protrusion could result in several conformational changes in the major capsid. All these structures, together with some biological results, suggest the protrusions' associations with the extracellular transmission of OmRV.

Objective: A decrease in oocyte developmental potential occurs in most mammalian species, including humans, and is a major obstacle for successful pregnancy in women of advanced age. Transcriptome and translation changes related to spindle assembly and chromosome separation defects in aged oocytes have been described in prior studies. However, the mechanism underlying these abnormalities is unclear. The age-related epigenetic modifications associated with dynamic transcriptome changes, particularly meiotic maturation-coupled mRNA clearance, have not been adequately characterized in human oocytes. Methods: This study generated a genome-wide database of meiotic maturation-coupled mRNA degradation in both young and aged mouse and human oocytes. Results: The results of this study demonstrate a decreased storage of transcripts encoding key factors regulating the maternal mRNA degradome prior to the oocyte-to-zygotic transition (OZT) in fully grown oocytes of women of advanced age. A similar defect in meiotic maturation-triggered mRNA clearance was also detected in aged mouse oocytes but was more likely due to insufficient translation of mRNAs encoding these OZT factors. Mechanistically, the epigenetic and cytoplasmic aspects of oocyte maturation are synchronized in both the normal development and aging processes. For example, the level of H3K4me3 was high in fully grown mouse and human oocytes derived from young females but gradually decreased during aging due to the decreased expression of maternal epigenetic factors responsible for genomic H3K4me3 accumulation. Conclusion: Taken together, these results suggest that H3K4me3, in association with mRNA decay competence, sets a timer for oocyte deterioration and plays a leading role in oocyte aging in both mouse and human oocytes. [ABSTRACT FROM AUTHOR]

Accumulation of dendritic cells (DCs) is a special characteristic of the decidual microenvironment. Decidua-infiltrated DCs show unique phenotypes and functions that promote the establishment of fetal-maternal tolerance. However, the regulatory mechanisms yet to be fully investigated. Decidual stromal cells (DSCs) are the major cellular component of decidua tissue. The interactions between DSCs and decidua-infiltrated immunocytes dictate immune tolerance in early pregnancy. Therefore, in the present study, we explore the effect of early pregnancy DSCs on monocyte-derived DCs and the relevant mechanisms. DSC-conditioned DCs showed altered phenotypes, secretion profiles and Th2 priming potential. G-CSF concentration was significantly up-regulated in the co-culture supernatant between DSCs and DCs. Supplementation of G-CSF neutralizing antibody partly reversed the reprogramming of DCs mediated by DSCs. Furthermore, G-CSF production was promoted by IL-1β, which was mainly produced by DCs and significantly up-regulated after their cultivation with DSCs. Interestingly, the effects of DSC on IL-1β production of DCs occurred in their immature stage but not their mature stage. Lastly, no significant difference of G-CSF was found in DSCs from healthy early pregnancy women and spontaneous abortions (SA) patients. However, DSCs from SA patients secreted less G-CSF in response to exogenous rhIL-1β or DC cultivation. In conclusion, our study bolster the understanding of the decidual immunomodulatory microenvironment during early pregnancy, and brings new insight into the potential clinical value of G-CSF in pregnancy disorders.

Novel UV-curable polyurethane acrylate (PUA) resins were developed from rubber seed oil (RSO). Firstly, hydroxylated rubber seed oil (HRSO) was prepared via an alcoholysis reaction of RSO with glycerol, and then HRSO was reacted with isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA) to produce the RSO-based PUA (RSO-PUA) oligomer. FT-IR and 1H NMR spectra collectively revealed that the obtained RSO-PUA was successfully synthesized, and the calculated C=C functionality of oligomer was 2.27 per fatty acid. Subsequently, a series of UV-curable resins were prepared and their ultimate properties, as well as UV-curing kinetics, were investigated. Notably, the UV-cured materials with 40% trimethylolpropane triacrylate (TMPTA) displayed a tensile strength of 11.7 MPa, an adhesion of 2 grade, a pencil hardness of 3H, a flexibility of 2 mm, and a glass transition temperature up to 109.4 °C. Finally, the optimal resin was used for digital light processing (DLP) 3D printing. The critical exposure energy of RSO-PUA (15.20 mJ/cm2) was lower than a commercial resin. In general, this work offered a simple method to prepare woody plant oil-based high-performance PUA resins that could be applied in the 3D printing industry.

A facile and environmental-friendly approach was developed for the preparation of the cross-linked nanocellulose aerogel through the freeze-drying process and subsequent esterification. The as-prepared aerogel had a three-dimensional cellular microstructure with ultra-low density of 6.05 mg·cm−3 and high porosity (99.61%). After modifying by chemical vapor deposition (CVD) with hexadecyltrimethoxysilane (HTMS), the nanocellulose aerogel displayed stable super-hydrophobicity and super-oleophilicity with water contact angle of 151°, and had excellent adsorption performance for various oil and organic solvents with the adsorption capacity of 77~226 g/g. Even after 30 cycles, the adsorption capacity of the nanocellulose aerogel for chloroform was as high as 170 g/g, indicating its outstanding reusability. Therefore, the superhydrophobic cross-linked nanocellulose aerogel is a promising oil adsorbent for wastewater treatment.

Poststroke cognitive impairment is a major secondary effect of ischemic stroke in many patients; however, few options are available for the early diagnosis and treatment of this condition. The aims of this study were to (1) determine the specific relationship between hypoxic and α-synuclein during the occur of poststroke cognitive impairment and (2) assess whether the serum phosphorylated α-synuclein level can be used as a biomarker for poststroke cognitive impairment. We found that the phosphorylated α-synuclein level was significantly increased and showed pathological aggregation around the cerebral infarct area in a mouse model of ischemic stroke. In addition, neuronal α-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia, suggesting that hypoxia is the underlying cause of α-synuclein-mediated pathology in the brains of mice with ischemic stroke. Serum phosphorylated α-synuclein levels in patients with ischemic stroke were significantly lower than those in healthy subjects, and were positively correlated with cognition levels in patients with ischemic stroke. Furthermore, a decrease in serum high-density lipoprotein levels in stroke patients was significantly correlated with a decrease in phosphorylated α-synuclein levels. Although ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury, some of them exhibited decreased cognitive function and reduced phosphorylated α-synuclein levels. Taken together, our results suggest that serum phosphorylated α-synuclein is a potential biomarker for poststroke cognitive impairment.

Different countries have different regulations for the approval and cultivation of crops developed by using new plant breeding technologies (NPBTs) such as gene editing. In this paper, we investigate the relationship between global food security and the level of NPBT regulation assuming a World Nation Official (WNO) proposes advice on global NPBT food policies. We show that a stricter NPBT food regulation reduces food security as measured by food availability, access, and utilization. We also find that political rivalry among interest groups worsens the food security status, given the NPBT food technology is more productive and the regulatory policy is influenced by lobbying. When the WNO aims to improve food security and weighs the NPBT food lobby contribution more than the non-NPBT food lobby's in the lobbying game, the total lobbying contributions will be the same for the WNO, and the NPBT food lobby will be more successful in the political process. The NPBT food lobby, however, under food security loses its advantage in the political competition, and this may result in a strict NPBT food policy. Under food security problems implementing stricter NPBT food regulations results in welfare losses. JEL Code: D04, D43, D72, P16

The present work simulates a concept about how to drive droplet flowing through non-wetting (hydrophobic) capillaries without any external force by using many-body dissipative particle dynamics. By decorating the capillary segments with wettability gradients, a droplet with proper radius can be absorbed by the non-wetting capillaries and then constantly flow through the capillary. The simulation results show the droplet can keep flowing through the whole capillaries under certain wettability gradients and the flow velocity also depends on the degree of the wettability gradients. The average wettability of the whole capillary is also essential for the continuous flowing, higher non-wetting capillaries can still keep the flowing with low wettability gradients due to less surface adhesion. A strategy on how to achieve longer flow pathway is also presented. It is also find that unbalanced uptake of droplet via lateral heterogeneous surfaces cannot stir the inside flow of the droplet. The simulation results could inspire the new design of microfluidics in which the transportation of droplet is an important aspect.

Actin cytoskeleton regulates many essential biological functions, including cellular development, shape, polarity, and motility. The organization of actin cytoskeleton has also been associated with numerous physiological and pathological conditions, for instance, the elongation of axonal growth cone during peripheral nerve regeneration. However, the spatio-temporal expression patterns of actin cytoskeleton-related genes and the specific roles of actin cytoskeleton following peripheral nerve injury have not been fully revealed. To address this question, we made rat sciatic nerve crush surgery, collected injured sciatic nerve stumps, analyzed RNA deep sequencing outcomes, and specifically studied two significantly involved canonical pathways that were related with actin, actin cytoskeleton signaling and regulation of actin-based motility by Rho. By using bioinformatic tools and qRT-PCR, We identified and validated differentially expressed genes in these two signaling pathways. Moreover, by applying actin polymerization inhibitor cytochalasin D to sciatic nerve crushed rats, we studied the in vivo effect of cytochalasin D and demonstrated that inhibiting actin polymerization would delay the migration of Schwann cells and hinder the repair and regeneration of injured peripheral nerves. Overall, our data revealed the changes of actin cytoskeleton-related genes following peripheral nerve injury and stated the importance of actin cytoskeleton during peripheral nerve regeneration.