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Abstract In mammals, global passive demethylation contributes to epigenetic reprogramming during early embryonic development. At this stage, the majority of DNA-methyltransferase 1 (DNMT1) protein is excluded from nucleus, which is considered the primary cause. However, whether the remaining nuclear activity of DNMT1 is regulated by additional mechanisms is unclear. Here, we report that nuclear DNMT1 abundance is finetuned through proteasomal degradation in mouse zygotes. We identify a maternal factor, Pramel15, which targets DNMT1 for degradation via Cullin-RING E3 ligases. Loss of Pramel15 elevates DNMT1 levels in the zygote pronuclei, impairs zygotic DNA demethylation, and causes a stochastic gain of DNA methylation in early embryos. Thus, Pramel15 can modulate the residual level of DNMT1 in the nucleus during zygotic DNA replication, thereby ensuring efficient DNA methylation reprogramming in early embryos.

Abstract Background Adverse drug events (ADEs) represent challenges affecting Africa’s healthcare systems owing to the increased healthcare expenditure and negative health outcomes of ADEs. Objectives We aimed to systematically review published studies on ADEs and synthesize the existing evidence of ADE prevalence in Africa. Methods Studies reporting on ADE occurrence in African settings and published from Jan 1, 2000 to Oct 1, 2023 were identified by searching PubMed, EBSCO, Science Direct, and Web of Science. Studies that either articulately investigated ADEs caused by clinical condition (such as HIV patients) or ADEs caused by exposure to specific drug(s) (such as antibiotics) were considered specific and the remaining were general. Grouped ADE prevalence rates were described using median and interquartile range (IQR). PROSPERO registration (CRD42022374095). Results We included 78 observational studies from 15 African countries that investigated the prevalence of ADEs leading to hospital admissions (17 studies), developed during hospitalizations (30 studies), and captured in the outpatient departments (38 studies) or communities (4 studies). Twelve studies included multiple settings. The median prevalence of ADE during hospitalization was 7.8% (IQR: 4.2–21.4%) and 74.2% (IQR: 54.1–90.7%) in general and specific patients, respectively. The ADE-related fatality rate was 0.1% and 1.3% in general and specific patients. The overall median prevalence of ADEs leading to hospital admissions was 6.0% (IQR: 1.5–9.0%); in general, patients and the median prevalence of ADEs in the outpatient and community settings were 22.9% (IQR: 14.6–56.1%) and 32.6% (IQR: 26.0–41.3%), respectively, with a median of 43.5% (IQR: 16.3–59.0%) and 12.4% (IQR: 7.1–28.1%) of ADEs being preventable in general and specific patients, respectively. Conclusions The prevalence of ADEs was significant in both hospital and community settings in Africa. A high ADE prevalence was observed in specific patients, emphasizing important areas for improvement, particularly in at-risk patient groups (e.g., pediatrics, HIV, and TB patients) in various settings. Due to limited studies conducted in the community setting, future research in this setting is encouraged.

Abstract Background The proximal femoral nail anti-rotation (PFNA) with cement enhancement enhances the anchorage ability of internal fixation in elderly with osteoporotic intertrochanteric fracture. However, whether it is superior to hemiarthroplasty is still controversial. The present study aimed to determine which treatment has better clinical outcomes among older patients. Methods We retrospectively analyzed 102 elderly patients with osteoporosis who developed intertrochanteric fractures and underwent PFNA combined with cement-enhanced internal fixation (n = 52, CE group), and hemiarthroplasty (n = 50, HA group) from September 2012 to October 2018. All the intertrochanteric fractures were classified according to the AO/OTA classification. Additionally, the operative time, intraoperative blood loss, intraoperative and postoperative blood transfusion rates, postoperative weight-bearing time, hospitalization time, Barthel Index of Activities Daily Living, Harris score of hip function, visual analog (VAS) pain score, and postoperative complications were compared between the two groups. Results The CE group had significantly shorter operative time, lesser intraoperative blood loss, lower blood transfusion rate, and longer postoperative weight-bearing time than the HA group. The CE group had lower Barthel’s Index of Activities of Daily Living, lower Harris’ score, and higher VAS scores in the first and third months after surgery than the HA group, but no difference was observed between the two groups from 6 months to 12 months. There was no significant difference in the total post-operative complications between the two groups. Conclusion The use of PFNA combined with a cement-enhanced internal fixation technique led to shorter operative time and lesser intraoperative blood loss and trauma in elderly patients as compared to HA.

ABSTRACT: Pekin ducks and Shaoxing ducks are 2 Chinese local duck breeds, both domesticated from mallard, but after domestication and long-term artificial selection, the body weight of Pekin ducks is significantly higher than that of Shaoxing ducks. It is no debate that genetic factors are the main factors responsible for this difference, but whether intestinal microbiota contribute to this difference is yet unknown. Thus, we performed comparative intestinal metagenomics and metabolomics analysis between Pekin ducks and Shaoxing ducks. We found obvious differentiation of intestinal metagenome and metabolome between the 2 breeds. Four cecal microbial genera, including Fusobacterium, Methanobrevibacter, Butyricicoccus, and Anaerotignum showed higher abundance in Pekin ducks. Among them, Methanobrevibacter and Butyricicoccus may positively correlate with fat deposition and body weight. A total of 310 metabolites showed difference between the 2 breeds. Functions of these differential metabolites were mainly enriched in amino acid metabolism, including energy metabolism-related histidine metabolism. Integrated omics analysis showed that microbial changes were closely related to altered metabolites. Especially, Butyricicoccus showing higher abundance in Pekin ducks was significantly negatively correlated with D-glucosamine-6-phosphate, which has been reported to prevent body weight gains. These findings may contribute to further understand the difference in body weight between Pekin ducks and Shaoxing ducks.

ABSTRACT: Egg production is an important economic trait in layer ducks and understanding the genetics basis is important for their breeding. In this study, a genome-wide association study (GWAS) for egg production traits in 303 female Longyan Shan-ma ducks was performed based on a genotyping-by-sequencing strategy. Sixty-two single nucleotide polymorphisms (SNPs) associated with egg weight traits were identified (P < 9.48 × 10-5), including 8 SNPs at 5% linkage disequilibrium (LD)-based Bonferroni-corrected genome-wide significance level (P < 4.74 × 10-6). One hundred and nineteen SNPs were associated with egg number traits (P < 9.48 × 10-5), including 13 SNPs with 5% LD-based Bonferroni-corrected genome-wide significance (P < 4.74 × 10-6). These SNPs annotated 146 target genes which contained known candidate genes for egg production traits, such as prolactin and prolactin releasing hormone receptor. This study identified that these associated genes were significantly enriched in egg production-related pathways (P < 0.05), such as the oxytocin signaling, MAPK signaling, and calcium signaling pathways. It was notable that 18 genes were differentially expressed in ovarian tissues between higher and lower egg production in Shan-ma ducks. The identified potential candidate genes and pathways provide insight into the genetic basis underlying the egg production trait of layer ducks.

To explore the influence of dynamic impacts on the creep properties of underground pillars, an underground coal sample is selected as the research material, and the mechanical response characteristics under dynamic impact are explored by the split Hopkinson pressure bar and high-speed camera. The results show that (1) when the creep stress level is higher, the initial deformation of coal is greater, and the damage to the sample through long-term creep is more severe. (2) With increasing levels of static stress, the dynamic strength and elastic modulus of the coal sample first increase and then decrease, and the dynamic elastic modulus is positively correlated with the impact velocity. (3) The static stress level determines the process of crack propagation and the degree of fracture, while the external dynamic impact determines the propagation speed of the crack. The results of this research enrich the theory of control systems for the prevention of coal pillar failure and instability and provide a theoretical basis for safe and efficient mining of working faces.

ObjectiveThe purpose of this study is to investigate potential associations between osteopenia, osteosarcopenia, and postoperative outcomes in patients with hepatobiliary-pancreatic cancer (HBPC).MethodsThree online databases, including Embase, PubMed, and the Cochrane Library, were thoroughly searched for literature describing the relationship between osteopenia, osteosarcopenia, and outcomes of surgical treatment of HBPC patients from the start of each database to September 29, 2023. The Newcastle-Ottawa Scale was used to rate the quality of the studies.ResultsThis analysis included a total of 16 articles with a combined patient cohort of 2,599 individuals. The results demonstrated that HBPC patients with osteopenia had significantly inferior OS (HR: 2.27, 95% CI: 1.70-3.03, p < 0.001) and RFS (HR: 1.96, 95% CI: 1.42-2.71, p < 0.001) compared to those without osteopenia. Subgroup analysis demonstrated that these findings were consistent across univariate and multivariate analyses, as well as hepatocellular carcinoma, biliary tract cancer, and pancreatic cancer. The risk of postoperative major complications was significantly higher in patients with osteopenia compared to those without osteopenia (OR: 1.66, 95% CI: 1.19-2.33, p < 0.001). Besides, we also found that the presence of osteosarcopenia in HBPC patients was significantly related to poorer OS (HR: 3.31, 95% CI: 2.00-5.48, p < 0.001) and PFS (HR: 2.50, 95% CI: 1.62-3.84, p < 0.001) in comparison to those without osteosarcopenia.ConclusionPreoperative osteopenia and osteosarcopenia can predict poorer OS and RFS with HBPC after surgery.

Abstract Based on the advantages of energy saving, environmental protection and high efficiency, carbon dioxide heat pump system has great application prospects. However, there are still many technical problems to be solved, especially the design and optimization of carbon dioxide centrifugal compressor. In this paper, a centrifugal compressor in carbon dioxide heat pump system is designed. The compressor is directly driven by a high-speed permanent magnet synchronous motor. Two-stage impellers are installed on both sides of the motor, and the bearings are active magnetic bearings. The influences of inlet pressure and temperature on compressor performance are analyzed. In the range of inlet temperature from 35 to 55 °C, with the decrease of inlet temperature, the compressor pressure ratio increases by 12–29.8%, the power increases by 2.7–8.6%. In the range of inlet pressure from 4 to 6 MPa, with the increase of inlet pressure, the compressor pressure ratio increases by 12.3–38.6%, and the power increases by 8.7–17.8%. In addition, the calculation method of compressor axial force is introduced, the axial force is calculated, analyzed and optimized. Furthermore, the rotor dynamics of compressor rotor and the influences of bearing stiffness and diameter of motor rotor on rotor dynamics are studied. With the increase of bearing stiffness, the first-order critical speed and maximum displacement of the rotor increase. The research provides a theoretical reference for the design and optimization of centrifugal compressor in carbon dioxide heat pump system.

Abstract The green hub‐and‐spoke airline network (GHSAN) is emerging as a dominant feature due to its excellent economic and environmental‐friendly capabilities. However, environmental GHSAN designs still have some concerns, including single pollutant‐domain oversimplification and lack of comprehensive network‐level operation impacts. This paper proposes a multi‐emission‐driven efficient network design approach for GHSAN, utilizing a system, green, and user threefold optimization methodology. The approach includes a multi‐objective optimization model and a two‐layer solving method. The multi‐objective optimization aims at minimizing multiple emissions, including carbon dioxide, carbonic oxide hydrocarbon, and nitric oxide, while also considering transportation system costs and journey user costs. A two‐layer optimization algorithm is adopted to address different scales of optimization. Real‐world results demonstrate that the proposed method mitigates environmental impact and user costs and increases overall airline density in airline networks. The proposed method can have a 16.29% reduction in green‐fold (10 nodes) and a 12.06% decrease in user costs for the user‐fold (10 nodes). As the number of nodes (15, 25, 50 nodes) and hubs (3, 4, 5, 6, 7 hubs) increase, the genetic algorithm (GA) proves to be more efficient and suitable in large‐scale GHSAN. This work is further significant for the long‐term and sustainable development of the future air transport industry.

Abstract Acute myeloid leukemia (AML), characterized by the abnormal accumulation of immature marrow cells in the bone marrow, is a malignant tumor of the blood system. Currently, the pathogenesis of AML is not yet clear. Therefore, this study aims to explore the mechanisms underlying the development of AML. Firstly, we identified a competing endogenous RNA (ceRNA) SUCLG2-AS1-miR-17-5p-JAK1 axis through bioinformatics analysis. Overexpression of SUCLG2-AS1 inhibits proliferation, migration and invasion and promotes apoptosis of AML cells. Secondly, luciferase reporter assay and RIP assay validated that SUCLG2-AS1 functioned as ceRNA for sponging miR-17-5p, further leading to JAK1 underexpression. Additionally, the results of MeRIP-qPCR and m6A RNA methylation quantification indicted that SUCLG2-AS1(lncRNA) had higher levels of m6A RNA methylation compared with controls, and SUCLG2-AS1 is regulated by m6A modification of WTAP in AML cells. WTAP, one of the main regulatory components of m6A methyltransferase complexes, proved to be highly expressed in AML and elevated WTAP is associated with poor prognosis of AML patients. Taken together, the WTAP-SUCLG2-AS1-miR-17-5p-JAK1 axis played essential roles in the process of AML development, which provided a novel therapeutic target for AML.

Abstract Background To demonstrate the technical feasibility of percutaneous nephrolithotomy (PCNL) guided by 5G-powered robot-assisted teleultrasound diagnosis system (RTDS) in a complex kidney-stone (CKS) cohort and present our preliminary outcomes. PCNL is highly skill-required, which hinders it popularization in primary medical units of remote regions. We designed an innovative tele-assistance approach to make PCNL easy to be operated by inexperienced surgeons. Methods This was a prospective proof-of-concept study (IDEAL phase 1) on intraoperative tele-assistance provided by online urological experts via a 5G-powered RTDS. Total 15 CKS patients accepted this technology. Online experts manipulated a simulated probe to assist unskilled local operators by driving a patient-side robot-probe to guide and monitor the steps of access establishment and finding residual stones. Results Median total delay was 177ms despite one-way network-connecting distance > 5,800 km. No perceptible delay of audio-visual communication, driving robot-arm or dynamic ultrasound images was fed back. Successful tele-assistance was obtained in all cases. The first-puncture access-success rate was 78.6% with a one-session SF rate of 71.3% and without complications of grade III-V. Conclusions The current technology based on 5G-powered RTDS can provide high-quality intraoperative tele-assistance, which has preliminarily shown satisfactory outcomes and reliable safety. It will break down a personal competence-based barrier to endow PCNL with more popular utilization. Trial registration The study was approved by ethics committee of the Xinjiang Kezhou People’s Hospital and ethics committee of the First Affiliated Hospital of Nanjing Medical University and was registered on http://www.chictr.org.cn (ChiCTR2200065849, 16/11/2022).

Objective Tibetan chickens, which have unique adaptations to extreme high-altitude environments, exhibit phenotypic and physiological characteristics that are distinct from those of lowland chickens. However, the mechanisms underlying hypoxic adaptation in the liver of chickens remain unknown. Methods RNA-sequencing (RNA-Seq) technology was used to assess the differentially expressed genes (DEGs) involved in hypoxia adaptation in highland chickens (native Tibetan chicken [HT]) and lowland chickens (Langshan chicken [LS], Beijing You chicken [BJ], Qingyuan Partridge chicken [QY], and Chahua chicken [CH]). Results A total of 352 co-DEGs were specifically screened between HT and four native lowland chicken breeds. Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analyses indicated that these co-DEGs were widely involved in lipid metabolism processes, such as the peroxisome proliferator-activated receptors (PPAR) signaling pathway, fatty acid degradation, fatty acid metabolism and fatty acid biosynthesis. To further determine the relationship from the 352 co-DEGs, protein-protein interaction network was carried out and identified eight genes (ACSL1, CPT1A, ACOX1, PPARC1A, SCD, ACSBG2, ACACA, and FASN) as the potential regulating genes that are responsible for the altitude difference between the HT and other four lowland chicken breeds. Conclusion This study provides novel insights into the molecular mechanisms regulating hypoxia adaptation via lipid metabolism in Tibetan chickens and other highland animals.

As the negative repercussions of environmental devastation, such as air quality decline and air pollution, become more apparent, environmental consciousness is growing across the world, forcing nations to take steps to mitigate the damage. China pledged to achieve air quality improvement goal to combat global environment issue, yet the spatial-temporal differentiation and its driving factors of environment-meteorology-economic index for air quality are not fully analysed. To promote regional collaborative control of air pollution and achieve sustainable urban development, spatial and temporal different and its driving factors of air quality in Shandong Province during 2013–2020. Results revealed that concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2), particulate matter 2.5 (PM2.5), particulate matter 10 (PM10), and carbon monoxide (CO-95per) exhibited decreasing trend (SO2 concentrations decreasing 84 % and CO-95per concentrations decreasing 90 %). Air quality was improved from inland areas to coastal areas. Pollutant indicators of SO2, NO2, PM10, PM2.5, and CO-95per demonstrated significant positive correlation (P < 0.05). Air temperature and precipitation are significantly negatively correlated with concentrations of SO2, NO2, PM10, PM2.5, and CO-95per but significantly positively correlated with ozone (O3-8 h). SO2, NO2, PM2.5, PM10, CO-95per, and proportion of days with heavy pollution are strongly positively correlated with proportion of secondary industry but strongly negatively correlated with proportion of tertiary industry and volume of household waste. Except for O3-8 h, pollutant index of Provincial Capital Economic Circle (PCEC) and Southern Shandong Economic Circle (SSEC) has significant negative correlation (P < 0.05) with regional gross domestic product and investment in environmental protection; however, investment in environmental protection of Eastern Shandong Economic Circle (ESEC) has no significant correlation with air pollution index. There was significant negative correlation between vegetable sowing area and SSEC pollutant index. The relationship between pollution emission and investment in environmental protection has shifted from high pollution-low investment to low pollution-low investment in PCEC, ESEC and SSEC, and the inflection point was in 2020 for PCEC, 2019 for ESEC, and 2020 for SSEC. Those results provide empirical evidence and theoretical support for the improvement of regional air quality, aiming to achieve high-quality development. According to these findings, it has been found that meteorological elements, pollutant emission, socio-economic factors and agricultural data affect air quality. Those results could provide meaningful and significant supporting for synergistic regulation of diverse pollutants.

BackgroundFerroptosis, a newly proposed concept of programmed cell death, has garnered significant attention in research across different diseases in the last decade. Despite thorough citation analyses in neuroscience, there is a scarcity of information on ferroptosis research specifically related to neurodegenerative diseases.MethodThe Web of Science Core Collection database retrieved relevant articles and reviews. Data on publications, countries, institutions, authors, journals, citations, and keywords in the included studies were systematically analyzed using Microsoft Excel 2019 and CiteSpace 6.2.R7 software.ResultA comprehensive analysis and visualization of 563 research papers on ferroptosis in neurodegenerative diseases from 2014 to 2023 revealed emerging research hotspots and trends. The number of annual publications in this field of study has displayed a pattern of stabilization in the early years of the decade, followed by a notable increase in the later years and peaking in 2023 with 196 publications. Regarding publication volume and total citations, notable research contributions were observed from countries, institutions, and authors in North America, Western Europe, and China. Current research endeavors primarily focus on understanding the intervention mechanisms of neurodegenerative diseases through the ferroptosis pathway and exploring and identifying potential therapeutic targets.ConclusionThe study highlights key areas of interest and emerging trends in ferroptosis research on neurodegenerative diseases, offering valuable insights for further exploration and potential directions for diagnosing and treating such conditions.

Introduction: With the development of artificial intelligence and autonomous driving technology, the application of motion recognition in automotive autonomous driving is becoming more and more important. The traditional feature extraction method uses adaptive search hybrid learning and needs to design the feature extraction process manually, which is difficult to meet the recognition requirements in complex environments.Methods: In this paper, a fusion algorithm is proposed to classify the driving characteristics through time-frequency analysis, and perform backpropagation operation in artificial neural network to improve the convergence speed of the algorithm. The performance analysis experiments of the study were carried out on Autov data sets, and the results were compared with those of the other three algorithms.Results: When the vehicle action coefficient is 227, the judgment accuracy of the four algorithms is 0.98, 0.94, 0.93 and 0.95, respectively, indicating that the fusion algorithm is stable. When the road sample is 547, the vehicle driving ability of the fusion algorithm is 4.7, which is the best performance among the four algorithms, indicating that the fusion algorithm has strong adaptability.Discussion: The results show that the fusion algorithm has practical significance in improving the autonomous operation ability of autonomous vehicles, reducing the frequency of vehicle accidents during driving, and contributing to the development of production, life and society.

ABSTRACT: Residual feed intake (RFI) is a crucial parameter for assessing the feeding efficiency of poultry. Minimizing RFI can enhance feed utilization and reduce costs. In this study, 315 healthy female ducks were individually housed in cages. Growth performance was monitored during the high laying period, from 290 to 325 d of age. The cecal transcriptome and microbiome of 12 ducks with high RFI and 12 with low residual feed intake (LRFI) were analyzed. Regarding growth performance, the LRFI group exhibited significantly lower RFI, feed conversion ratio (FCR), and feed intake (Fi) compared to the HRFI group (p < 0.01). However, there were no significant differences observed in body weight (BW), body weight gain (BWG), and egg mass (EML) between the groups (p > 0.05). Microbiome analysis demonstrated that RFI impacted gut microbial abundance, particularly affecting metabolism and disease-related microorganisms such as Romboutsia, Enterococcus, and Megamonas funiformis. Transcriptome analysis revealed that varying RFI changed the expression of genes related to glucose metabolism and lipid metabolism, including APOA1, G6PC1, PCK1, and PLIN1. The integrated analysis indicated that host genes were closely linked to the microbiota and primarily function in lipid metabolism, which may enhance feeding efficiency by influencing metabolism and maintaining gut homeostasis.

Copper (Cu) serves as an essential cofactor in all organisms, yet excessive Cu exposure is widely recognized for its role in inducing liver inflammation. However, the precise mechanism by which Cu triggers liver inflammation in ducks, particularly in relation to the interplay in gut microbiota regulation, has remained elusive. In this investigation, we sought to elucidate the impact of Cu exposure on liver inflammation through gut-liver axis in ducks. Our findings revealed that Cu exposure markedly elevated liver AST and ALT levels and induced liver inflammation through upregulating pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) and triggering the LPS/TLR4/NF-κB signaling pathway. Simultaneously, Cu exposure induced alterations in the composition of intestinal flora communities, notably increasing the relative abundance of Sphingobacterium, Campylobacter, Acinetobacter and reducing the relative abundance of Lactobacillus. Cu exposure significantly decreased the protein expression related to intestinal barrier (Occludin, Claudin-1 and ZO-1) and promoted the secretion of intestinal pro-inflammatory cytokines. Furthermore, correlation analysis was observed that intestinal microbiome and gut barrier induced by Cu were closely related to liver inflammation. Fecal microbiota transplantation (FMT) experiments further demonstrated the microbiota-depleted ducks transplanting fecal samples from Cu-exposed ducks disturbed the intestinal dysfunction, which lead to impaire liver function and activate the liver inflammation. Our study provided insights into the mechanism by which Cu exposure induced liver inflammation in ducks through the regulation of gut-liver axis. These results enhanced our comprehension of the potential mechanisms driving Cu-induced hepatotoxicity in avian species.

Dendrobium officinale leaves (DOL) contain many active ingredients with various pharmacological effects, but are still ineffectively utilized. To investigate the feasibility of developing DOL as a feed additive, it is necessary to determine whether dietary supplementing DOL had any effect on meat quality and flavor. Our results showed that supplementation with DOL decreased the shear force while increased the pH and fat content in breast meat. Meat from DOL-fed chickens had higher levels of n-3 polyunsaturated fatty acids (PUFAs) and n-6 PUFAs, but lower n-6/n-3 ratios. Moreover, volatile compounds profile indicated that contents of aldehydes, including hexanal, pentanal, and heptanal, etc.), which were identified as the key volatile compounds in chicken meat, exhibited noteworthy rise in DOL intake groups. Octanal, 1-octen-3-ol, and 2-pentylfuran also contributed greatly to the meat overall aroma. These data provide a foundation for the comprehensive utilization of DOL as a feed additive with antibiotic substitution potential.

IntroductionThis study examined the impact of adding coated sodium butyrate (CSB) to the diet on the growth performance, serum biochemistry, antioxidant capacity, intestinal morphology, and cecal microbiota of yellow-feathered broiler chickens.MethodsIn this study, 240 yellow-feathered broiler chickens at 26 days old were divided into two groups: the control group (CON group) received a standard diet, and the experimental group (CSB group) received a diet with 0.5 g/kg of a supplement called CSB. Each group had 6 replicates, with 20 chickens in each replicate, and the experiment lasted for 36 days.ResultsCompared to the CON group, the CSB group showed a slight but insignificant increase in average daily weight gain during the 26–62 day period, while feed intake significantly decreased. The CSB group exhibited significant increases in serum superoxide dismutase, catalase, and total antioxidant capacity. Additionally, the CSB group had significant increases in total protein and albumin content, as well as a significant decrease in blood ammonia levels. Compared to the CON group, the CSB group had significantly increased small intestine villus height and significantly decreased jejunal crypt depth. The abundance of Bacteroidetes and Bacteroides in the cecal microbiota of the CSB group was significantly higher than that of the CON group, while the abundance of Proteobacteria, Deferribacteres, and Epsilonbacteraeota was significantly lower than that of the CON group.ConclusionThese results suggest that adding CSB to the diet can improve the growth performance and antioxidant capacity of yellow-feathered broiler chickens while maintaining intestinal health.

ABSTRACT: In order to explore the difference and its underlying mechanism between young and older ducks, 60-day-old (D60) and 300-day-old (D300) of young ducks and 900-day-old ducks (D900) of older ducks were selected and studied. HE staining indicated that breast muscle fibers in the D900 group were more inseparable than D60 and D300 groups and the greater redness were showed in D300 and D900 groups. Quantitative proteomic analyses were conducted to further identify differences between young and older ducks that 61 proteins overlapped in the comparative analysis of the D900 vs. D60 and D900 vs. D300 groups. Furthermore, metabolomics analysis from the D900 group showed marked differences from the results of the D60 and D300 groups in 31 unique metabolites. In particular, lower guanosine, hypoxanthine, guanine, and doxefazepam levels indicated the increased nutritional value of older ducks. Integrated proteomics and metabolomics analysis showed that purine metabolism was specifically enriched, indicating that NME3, RRM2B, AMPD1, and AMPD3 might mainly affect meat from older ducks. In conclusion, our results indicated that meat from 900-day-old ducks possessed a unique biochemical signature that could provide candidate biomarkers to distinguish young ducks from older ducks.

Primate tourism brings many benefits, but also some problems. How to better evaluate primate tourism is of significance for formulating tourism management strategies. In this study, we compared the aggressive behavior of three Sichuan snub-nosed monkey groups that encounter ecotourists and found that male aggressive behavior is a useful indicator for assessing ecotourism of these and, by inference, other groups. In high-risk tourism groups multiple monkeys direct aggression towards tourists, whereas low-risk tourism groups are characterized by low rates of such aggression. We found that tourists touching or attempting to touch the monkeys can trigger aggressive behaviors in all groups, while carrying food and eating have different effects across groups. In well-managed groups, tourist-directed aggressive behaviors are milder than in less well-managed groups. We propose that male monkey aggressive behavior elicited by tourists’ behavior is a useful indicator in assessing primate tourism, and can help guide further improvements in tourism management.

Abstract Background Amiodarone and esmolol can help to prevent and treat post-cardiac surgery reperfusion ventricular fibrillation. However, the relative efficacies of these two drugs remain unknown. The aim of the current trial is to compare the performances of amiodarone and esmolol for preventing reperfusion ventricular fibrillation following open heart surgery. Methods/design This is a single-center, prospective, double-blind, controlled clinical trial. A total of 260 patients undergoing heart valve or aortic surgery will be assigned randomly to treatment with prophylactic esmolol (intervention group) or amiodarone (control group). The main outcome is the incidence of reperfusion ventricular fibrillation following aortic opening during extracorporeal circulation. The secondary outcomes are the rate of automatic cardiac resuscitation, energy and frequency of electrical defibrillation, number of electrical defibrillations, and pacemaker use in the two groups of patients. Information on the patients’ general condition and the durations of anesthesia, extracorporeal circulation, aortic occlusion, and operation time will be recorded. We will also compare the heart rate, mean arterial pressure, and central venous pressure between the two groups of patients at induction of anesthesia (T1), start of surgery (T2), start of extracorporeal circulation (T3), aortic block (T4), aortic opening (T5), after opening for 10 (T6), 20 (T7), and 30 min (T8), at cessation of extracorporeal circulation (T9), and at the end of surgery (T10) and compare blood gas analysis results at T1, T5, T9, and T10. Discussion This study will determine if prophylactic esmolol is more effective than amiodarone for reducing the incidence of reperfusion ventricular fibrillation in patients undergoing heart valve or aortic surgery. Trial registration China Clinical Trials Registry ChiCTR1900026429. Registered on 2019.10.9.

Abstract Background Both acute normovolumic hemodilution (ANH) and autologous platelet-rich plasma (aPRP) have been demonstrated blood-protective effects in cardiac aortic surgery; however, the efficacies of the two methods have not been compared. This study aims to compare the effects of aPRP and ANH prior to aortic surgery on postoperative bleed and other outcomes. Methods and analysis This is a prospective, single-center, double-blind controlled clinical trial including 160 patients randomized 1:1 to receive aPRP (test group) or autologous whole blood (ANH, control group). The primary objective is to compare the drainage volumes in the two groups at 24, 48, and 72 h postoperatively. Secondary outcomes include input of allogeneic blood and blood products and durations of aortic block, extracorporeal circulation, deep hypothermic arrest of circulation, tracheal extubation, hospital stay, requirement for secondary surgical hemostasis, and application of intra-aortic balloon pump or extracorporeal membrane oxygenation in the two groups. In addition, heart rate, systolic blood pressure, diastolic blood pressure, central venous pressure, and thromboelastography recorded before blood reservation (T1), after blood reservation (T2), before blood transfusion (T3), and after the blood is returned (T4) to the transfusion will be compared between the two groups of patients. Discussion This study will demonstrate if the use of aPRP could reduce the risk of bleeding after aortic surgery compared with ANH. The results are expected to have practical clinical applications in terms of more effective blood protection and shorter hospital stay. Trial registration This study was registered with the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ) with the ID ChiCTR 1900023351.Registered on May 23, 2019. Trial status Recruiting start date: July 1, 2019; expected recruiting end date: July 1, 2024 Version number and date: Version 2 of 05-04-2019

There are numerous risk factors across various dimensions that lead to unsafe behaviors among construction workers, and the interactions between these factors are complex and intertwined. Therefore, it is crucial to comprehensively explore the mechanisms of these risk factors across all dimensions to reduce the accident rate. This paper combines cascading failure and entropy flow models to construct a cascading trigger model for identifying key nodes and paths in a risk network. First, this paper identifies the risk factors in the individual, organizational, managerial, and environmental dimensions, dividing them into deep and surface factors. Based on this, a risk network is constructed, and cascading failure is introduced to simulate the dynamic evolution of risks. Then, the entropy flow model is introduced to quantify the risk flow in risk propagation. Finally, to address the uncertainty of risk occurrence, Visual Studio Code is used for coding, and a simulation platform is built using JavaScript. After conducting simulation experiments, the results are statistically analyzed. The results show that the key nodes of deep factors are mainly concentrated in the individual dimension (herd mentality, negative emotions, physical fatigue, fluke mindset), organizational dimension (poor cohesion, poor internal communication), and managerial dimension (abusive leadership style and insufficient/low-quality safety education and training); the surface factors are mainly the poor safety climate in the organizational dimension. The findings provide theoretical support for reducing the accident rate caused by unsafe worker behaviors, aiming to reduce accident risk losses by cutting off risk propagation paths.

ABSTRACT: Feed costs account for approximately 60 to 70% of the cost of poultry farming, and feed utilization is closely related to the profitability of the poultry industry. To understand the causes of the differences in feeding in Shan Partridge ducks, we compared the hypothalamus transcriptome profiles of 2 groups of ducks using RNA-seq. The 2 groups were: 1) low-residual feed intake (LRFI) group with low feed intake but high feed efficiency, and 2) high-residual feed intake (HRFI) group with high feed intake but low feed efficiency. We found 78 DEGs were enriched in 9 differential Kyoto Encyclopedia of Genes and Genome (KEGG) pathways, including neuroactive ligand-receptor interaction, GABAergic synapse, nitrogen metabolism, cAMP signaling pathway, calcium signaling pathway, nitrogen metabolism, tyrosine metabolism, ovarian steroidogenesis, and gluconeogenesis. To further identify core genes among the 78 DEGs, we performed protein-protein interaction and coexpression network analyses. After comprehensive analysis and experimental validation, 4 core genes, namely, glucagon (GCG), cholecystokinin (CCK), gamma-aminobutyric acid type A receptor subunit delta (GABRD), and gamma-aminobutyric acid type A receptor subunit beta1 (GABRB1), were identified as potential core genes responsible for the difference in residual feeding intake between the 2 breeds. We also investigated the level of cholecystokinin (CCK), neuropeptide Y (NPY), peptide YY (PYY), ghrelin, and glucagon-like peptide1 (GLP-1) hormones in the sera of Shan Partridge ducks at different feeding levels and found that there was a difference between the 2 groups with respect to GLP-1 and NPY levels. The findings will serve as a reference for future research on the feeding efficiency of Shan Partridge ducks and assist in promoting their genetic breeding.

Given the pressing requirements for sustainable development in civil aviation, conducting a synergistic evolution analysis of the supply and demand aspects in the airport green development holds great significance. This analysis helps achieve sustainable airport development and facilitates the green transformation of civil aviation development. Taking a collaborative learning approach and utilizing historical data from Guangzhou Baiyun International Airport spanning 2008 to 2019, the supply-demand composite system for airport green development was deconstructed into two subsystems-demand and supply-and relevant evaluation index systems were established in this paper. A screening and optimization model of supply and demand synergy indicators for airport green development was constructed, and it was solved using a simulated annealing genetic algorithm. The Haken model was constructed to analyze the synergistic evolutionary relationship of the composite system of supply and demand for green airport development in two stages. The results indicate a shift in the order parameter of the co-evolution of the supply-demand composite system at Guangzhou Baiyun International Airport, moving from the demand subsystem in the first stage (2008-2015) to the supply subsystem in the second stage (2016-2019). The co-evolution of the airport supply-demand composite system has entered a new stage, but has not reached a high level of synergy. The study not only contributes theoretically by explaining the interaction mechanism between supply and demand for airport green development, but also offers targeted suggestions for achieving high-quality synergistic evolution of supply and demand for airport green development.

Abstract Purpose The motor symptoms (MS) of Parkinson's disease (PD) have been affecting the quality of life in patients. In clinical practice, most patients with PD report that MS are more severe in winter than in summer, and hyperthermic baths (HTB) could temporarily improve MS. The study aimed to evaluate the effects of seasonal variation and aquatic thermal environment of HTB on the MS of PD. Patients and methods A cross‐sectional study of 203 Chinese Han patients was performed. Univariate and multivariate analyses were performed to analyze seasonal variation in MS relative to baseline data (sex, age at onset, duration, season of birth, Hoehn and Yahr stage, family history, levodopa equivalent dose, and the effect of HTB on MS). Ten subjects participated in the HTB study, and one patient dropped out. The paired Wilcoxon rank test was used to assess the differences in the Movement Disorder Society‐United Parkinson's disease Rating Scale (MDS‐UPDRS) part III motor examination total scores and the modified Webster Symptoms Score between non‐HTB and before HTB and between non‐HTB and after HTB. Results The improvement of MS after HTB was an independent risk factor for seasonal variation in MS (OR, 25.203; 95% CI, 10.951–58.006; p = .000). Patients with PD had significant improvements in the MDS‐UPDRS part III motor examination total scores, especially in bradykinesia (p = .043), rigidity (p = .008), posture (p = .038), and rest tremor amplitude (p = .047). Conclusion Seasonal variation in temperature and water temperature of HTB may affect MS in some patients with PD. Simple HTB could be recommended as physiotherapy for patients with PD who report temperature‐sensitive MS.

Foods contain a variety of macromolecules such as proteins as well as trace flavor compounds and the binding effect between aroma compounds and the protein matrix has an important impact on the release and perception of the overall flavor of foods. In this paper, we systematically review the mechanism, determination methods, mathematical models and influential factors of the binding effect between proteins and aroma compounds, and summarize the binding interactions between proteins and aroma compounds including non-covalent bonding, covalent bonding and mass transfer effect, and presents a systematic comparison of the application of multispectral techniques such as fluorescence, circular dichroism and Fourier transform infrared spectroscopy to the investigation of the protein-aroma compound binding effect. Moreover, we summarize several common theoretical models and emerging molecular docking and molecular dynamics simulation methods available for research on the binding interactions between proteins and aroma compounds, and review the influential factors of the release and retention of aroma compounds bound to the protein matrix from three perspectives: protein, aroma compounds and food ingredients. Furthermore, we discuss the major problems existing in the current research and put forward some suggestions for future research directions in order to provide a scientific basis and reference for the controllable release of aroma compounds bound to proteins in foods.

Objective: To investigate the risk factors and outcomes regarding acute kidney injury (AKI) after AngioJet thrombectomy for acute lower-extremity deep vein thrombosis (DVT). Methods: Patients were divided into AKI and non-AKI groups according to whether AKI occurred postoperatively. The demographic data, pre-operative and post-operative laboratory data and surgical differences were compared between the two groups. Logistic regression and Wilcoxon signed-rank test were used to identify the AKI risk factors and outcomes, respectively. Results: Among the 341 patients who met the inclusion criteria, 45 developed AKI (AKI group) and 296 had normal renal function (non-AKI group) post-surgery. There were significant differences between the two groups in the course (t = 10.885, P = 0.000); preoperative history of a major surgery within 3 months (3M-MS) (odds ratio [OR] = 5.492, P = 0.001); duration of aspiration thrombectomy (Z = −8.803, P = 0.000); volumes of aspiration (Z = −8.215, P = 0.000); contrast volume (Z = −3.204, P = 0.001) and pulmonary thrombectomy (OR = 18.200, P = 0.002); and preoperative complications of hypertension (OR = 4.637, P = 0.002), diabetes (OR = 18.088, P = 0.000), or pulmonary embolism (OR = 0.085, P = 0.011). Wilcoxon signed-rank test showed that the renal function of every patient in the AKI group returned to normal 3 months after the surgery. Conclusions: The course, preoperative complications of diabetes or hypertension, 3M-MS, contrast volume, duration and volume of aspiration thrombectomy, and pulmonary thrombectomy are risk factors for post–AngioJet-thrombectomy AKI, which is temporary.

Abstract Passive crowd counting using channel state information (CSI) is a promising technology for applications in fields such as smart cities and commerce. However, the most existing algorithms can only recognize the total number of people in the monitoring area and cannot simultaneously recognize the number and states of people and ignore the real-time performance of the algorithms. Therefore, they cannot be applied to the scenarios of multi-state crowd counting requiring high real-time performance. To address this issue, a lightweight passive multi-state crowd counting algorithm called TF-LPMCC is proposed. This algorithm constructs CSI amplitude data into amplitude and time–frequency images, extracts texture features using the gray-level co-occurrence matrix (GLCM) and gray-level difference statistic (GLDS) methods, and uses the linear discriminant analysis (LDA) algorithm to count the crowd in multi-states. Experiments show that the TF-LPMCC algorithm not only has low time complexity but also achieves an average recognition accuracy of 98.27% for crowd counting.

Oxidative stress increases the apoptosis of intestinal epithelial cells and impairs intestinal epithelial cell renewal, which further promotes intestinal barrier dysfunction and even death. Extensive evidence supports that resveratrol and apigenin have antioxidant, anti-inflammatory, and antiproliferative properties. Here, we investigated the ability of these two compounds to alleviate diquat-induced jejunal oxidative stress and morphological injury, using the duck as a model, as well as the effects of apigenin on oxidative stress induced by H2O2 in immortalized duck intestinal epithelial cells (IDECs). Ducks were randomly assigned to the following four groups, with five replicates: a control (CON) group, a diquat-challenged (DIQ) group, a resveratrol (500 mg/kg) + diquat (RES) group, and an apigenin (500 mg/kg) + diquat (API) group. We found that serum catalase (CAT) activity and total antioxidant capacity (T-AOC) markedly reduced in the RES and API groups as compared to the DIQ group (p < 0.05); moreover, serum S superoxide dismutase (SOD) levels increased significantly in the API group as compared to the DIQ group (p < 0.05). In jejunal mucosa, the malondialdehyde (MDA) content in the RES and API groups decreased more than that in the DIQ group (p < 0.05). In addition, the jejunal expression levels of the NRF2 and GCLM genes in the RES and API groups increased notably compared with those in the DIQ group (p < 0.05); meanwhile, CAT activity in the RES and API groups was markedly elevated compared with that in the CON group (p < 0.05). In IDECs, apigenin significantly restrained the H2O2-mediated increase in MDA content and decrease in CAT levels (p < 0.05). Furthermore, apigenin increased the protein expression of p-NRF2, NRF2, p-AKT, and p-P38; downregulated that of cleaved caspase-3 and cleaved caspase-9; and reduced the ratio of Bax/Bcl-2 in H2O2-treated IDECs (p < 0.05). In conclusion, resveratrol and apigenin can be used as natural feed additives to protect against jejunal oxidative stress in ducks.

BackgroundMounting evidence has demonstrated the associations between gut microbiota, gut microbiota-derived metabolites, and cerebrovascular diseases (CVDs). The major categories of CVD are ischemic stroke (IS), intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). However, the causal relationship is still unclear.MethodsA two-sample Mendelian randomization (MR) study was conducted leveraging the summary data from genome-wide association studies. The inverse variance-weighted, maximum likelihood, weighted median, and MR.RAPS methods were performed to detect the causal relationship. Several sensitivity analyses were carried out to evaluate potential horizontal pleiotropy and heterogeneity. Finally, reverse MR analysis was conducted to examine the likelihood of reverse causality, and multivariable MR was performed to adjust the potential confounders.ResultsWe collected 1,505 host single nucleotide polymorphisms (SNPs) linked to 119 gut microbiota traits and 1,873 host SNPs associated with 81 gut metabolite traits as exposure data. Among these, three gut bacteria indicated an elevated risk of IS, two of ICH, and one of SAH. In contrast, five gut bacteria were associated with a reduced risk of IS, one with ICH, and one with SAH. Our study also demonstrated the potential causal associations between 11 gut microbiota-derived metabolites and CVD.ConclusionsThis study provided evidence of the causal relationship between gut microbiota, gut microbiota-derived metabolites, and CVD, thereby offering novel perspectives on gut biomarkers and targeted prevention and treatment for CVD.

Drip irrigation is deemed as a solution to the water conflict between agricultural and ecological needs in arid regions, but assessing hydrological impacts of drip irrigation remains challenging. This study developed a new approach to simulating drip irrigation at a basin scale, with the configuration of irrigation system explicitly represented and the emitter-scale wetted soil volume directly modeled, and incorporated the approach into HEIFLOW, a fully distributed and physically based ecohydrological model. The improved model, named HEIFLOW-drip, was used to study the potential implementation of drip irrigation in the Zhangye basin in Northwest China. Due to the recycling effect of irrigation return flow, the basin-scale water-saving efficiency (WSE) of drip irrigation fully implemented in the irrigated farmlands is 16.8%, less than half of its field-scale WSE (36.5%). This discrepancy indicates that accounting the water saved in fields may lead to notable overestimation of the basin-wide water saving by drip irrigation in basins with strong surface water-groundwater interactions. If fully implemented, drip irrigation would significantly alter the regional water balance, increasing the stream outflow by approximately 30%, while causing a decline in groundwater level. This tradeoff can be alleviated by tuning the management parameters of drip irrigation, which can achieve a synergistic effect of increasing the streamflow while preventing dramatic groundwater depletion. Another effective strategy is to implement drip irrigation in part of the basin. Given the intricate impacts of drip irrigation on hydrological processes, the determination of the scale and location of drip irrigation should be thought through at the basin level. Further analyses indicate the importance of proper management of the water saved by drip irrigation, which is crucial to prevent the paradox of irrigation efficiency. The findings of this study have great implications for addressing the complex water-food-ecosystem nexus in arid endorheic river basins.

Condiments are necessary to improve the flavor of foods and are a major source of salt intake for people. Excess salt intake can be a health risk, but reducing salt can reduce the umami and taste of foods, thus reducing product quality. This paper reviews the technical strategies for salt reduction while ensuring saltiness and umami as well as their harmony. The salt reduction strategies include reducing the amount of salt, using salt substitutes and enhancing saltiness perception. The umami enhancement strategies include adding yeast extracts, umami peptides, umami amino acids and peptide derivatives. Besides, salt reduction and umami enhancement can be achieved by using lactic acid bacteria, Maillard reaction intermediates, flavor enhancers and taste-active peptides. The application of the salt reduction and umami enhancement strategies will promote the development of the condiment industry, but these strategies have the problems of insufficient basic research, few practical applications, narrow application scope and high production cost. At present, it is difficult to solve these problems. In this paper, the basic principles and characteristics of the strategies for salt reduction and umami enhancement in condiments and the current problems existing in this field of research are reviewed in detail. Future development directions are put forward in order to provide a reference for research on salt reduction and umami enhancement of condiments.

The prestress loss has a great influence on the integrity and tightness of the containment. As the service age of the containment increases, the prestress loss gradually increases. The operating experience of most nuclear power plants shows that the rate of prestress loss in the containment exceeds even the expected value of the initial design. At present, most scholars evaluate the prestress loss of the containment only at the end of the life of the containment, and there is little research on the safety performance of the containment under different internal pressure after the loss of prestress. From this, the whole life theory to the evaluation method of containment safety performance of nuclear power plants was introduced in this paper. The safety performance of the containment under different levels of internal pressure during the design basis period of 40 years and 60 years following the design basis period was evaluated, taking into account the prestress loss at various ages of the containment. The ABAQUS finite element software was used to create a refined three-dimensional finite element analysis model of the containment, prestress loss calculation based on Concrete Structure Design Code (GB 500102010) and application of prestressing in ABAQUS by the cooling method. The nonlinear finite element method was used to analyze performance indicators such as the yield of the steel liner, the yield of the prestressed tendons, and the evolution of concrete cracks. The findings reveal that when the containment concrete cracks and the steel liner fails, the internal pressure capacity that the containment can withstand is reduced after accounting for prestress loss, and the maximum equivalent plastic strain in the steel liner of the containment is concentrated at the top and bottom sides of the equipment hatch, the crack development of the containment concrete is also more serious than that without considering the prestress loss, and the crack development of the equipment hatch is changed from horizontal to oblique cracks. The deformation of the containment under the ultimate internal pressure is manifested by the outward expansion of the dome and the inward contraction of the equipment hatch. The dome of the containment is severely damaged under ultimate internal pressure. Containment’s deformation increases significantly after considering the prestress loss. However, the containment still has sufficient safety margin under the design internal pressure (0.4 MPa) after 40 years of design base period for containment service and consideration of extending service to 100 years. The above results have implications for the structural design and the assessment of life extension of containment.

Abstract It remains poorly understood about the regulation of gene and transposon transcription during human early embryogenesis. Here, we report that broad H3K27ac domains are genome-widely distributed in human 2-cell and 4-cell embryos and transit into typical peaks in the 8-cell embryos. The broad H3K27ac domains in early embryos before zygotic genome activation (ZGA) are also observed in mouse. It suggests that broad H3K27ac domains play conserved functions before ZGA in mammals. Intriguingly, a large portion of broad H3K27ac domains overlap with broad H3K4me3 domains. Further investigation reveals that histone deacetylases are required for the removal or transition of broad H3K27ac domains and ZGA. After ZGA, the number of typical H3K27ac peaks is dynamic, which is associated with the stage-specific gene expression. Furthermore, P300 is important for the establishment of H3K27ac peaks and the expression of associated genes in early embryos after ZGA. Our data also indicate that H3K27ac marks active transposons in early embryos. Interestingly, H3K27ac and H3K18ac signals rather than H3K9ac signals are enriched at ERVK elements in mouse embryos after ZGA. It suggests that different types of histone acetylations exert distinct roles in the activation of transposons. In summary, H3K27ac modification undergoes extensive reprogramming during early embryo development in mammals, which is associated with the expression of genes and transposons.

Metamaterials have attracted increasing attention in recent years due to their powerful abilities in manipulating electromagnetic (EM) waves. However, most previously reported metamaterials are unable to actively control full-band EM waves. In this paper, we propose a thermo-tunable broadband metamaterial (T-TBM) using paraffin-based composites (PD-Cs) with different phase transition temperatures. Active control of the T-TBM reflection loss peaks from low to high frequency is realized by manipulating the solid–liquid state of the PD-Cs at different phase transition temperatures. The absorption peak bandwidth (where the reflection loss value is less than −30 dB) can be changed, while the broad bandwidth absorption (where the reflection loss value is less than −10 dB) is satisfied by adjusting the temperature of the T-TBM. It is shown that the stagnation of the phase transition temperature of the PD-Cs in the T-TBM provides a time window for actively controlling the EM wave absorption response under different thermal conditions. The device has a broad application prospect in the fields of EM absorption, intelligent metamaterials, multifunctional structural devices, and more.

To explore the influence of dynamic impacts on the creep properties of underground pillars, an underground coal sample is selected as the research material, and the mechanical response characteristics under dynamic impact are explored by the split Hopkinson pressure bar and high-speed camera. The results show that (1) when the creep stress level is higher, the initial deformation of coal is greater, and the damage to the sample through long-term creep is more severe. (2) With increasing levels of static stress, the dynamic strength and elastic modulus of the coal sample first increase and then decrease, and the dynamic elastic modulus is positively correlated with the impact velocity. (3) The static stress level determines the process of crack propagation and the degree of fracture, while the external dynamic impact determines the propagation speed of the crack. The results of this research enrich the theory of control systems for the prevention of coal pillar failure and instability and provide a theoretical basis for safe and efficient mining of working faces. [ABSTRACT FROM AUTHOR]

The investigation of the mechanical properties of rock mass can be effectively carried out through rock-like material experiments. In this study, polystyrene foam particles were utilized as a novel material for simulating initial damage within rocks. Our research involved the development of sandstone-like materials with comparable mechanical properties to actual sandstone. These materials were then subjected to orthogonal mechanical tests, allowing us to identify the key factors that have a substantial impact on the mechanical parameters of sandstone-like rocks. The influencing factors considered in the orthogonal mechanical tests were the proportion of aggregate and binder, the proportion of polystyrene foam in the entire model, the proportion of binder and regulator, and the size of polystyrene foam. Five levels were set for each factor, and mechanical parameters such as compressive strength, tensile strength, elastic modulus, axial strain, and Poisson’s ratio were tested for each group of samples. The changes in mechanical parameters with the levels of the above four factors were studied. The study found that modifying the proportion of aggregate to binder can alter the elastic modulus, tensile strength, and compressive strength values of sandstone-like material. The size of polystyrene foam can be modified to alter the axial strain values of sandstone-like materials. Additionally, adjusting the ratio of binder and regulator can modify the value of Poisson’s ratio. The comparison of mechanical parameters between sandstone-like samples and sandstone reveals that sandstone-like materials can better simulate the deformation and failure mechanisms of sandstone. The error in the main mechanical parameters, such as modulus of elasticity, strength, and Poisson’s ratio, is less than 7%, indicating a greater resemblance between sandstone-like materials and sandstone. Therefore, sandstone-like materials can be used to investigate the deformation law, damage evolution law, and failure mechanism of sandstone. This can help alleviate the difficulty of obtaining specimens of deep damaged rock and the high cost of testing.

The supercritical carbon dioxide (S-CO2) Brayton cycle efficiency increases as the compressor inlet condition approaches the critical point. However, the thermodynamic properties of CO2 vary dramatically near the critical point, and phase change is most likely to happen. Both cavitation and condensation bring about significant adverse effects on the performance of compressors. In this paper, the quantitative effects of nonequilibrium condensation and cavitation on the performance of an S-CO2 centrifugal compressor with different inlet-relative entropy values are investigated. The properties of CO2 were provided by the real-gas property table, and the nonequilibrium phase-change model was adopted. The numerical simulation method with the nonequilibrium phase-change model was validated in the Lettieri nozzle and Sandia compressor. Furthermore, simulations were carried out in a two-stage centrifugal compressor under conditions of various inlet-relative entropy values. The type of nonequilibrium phase change can be distinguished by inlet-relative entropy. Cavitation makes the choke mass flow rate decrease due to the drop in the speed of sound. Condensation mainly occurs on the leading edge of the main blade at a large mass flow rate, but cavitation occurs on the splitter. The condensation is more evenly distributed on the main blade, but the cavitation is mainly centered on the leading edge.