Thermal fatigue and wear of compacted graphite iron brake discs with various thermomechanical properties

The increase in payload capacity of trucks has heightened the demand for cost-effective yet high performance brake discs.In this work,the thermal fatigue and wear of compacted graphite iron brake discs were investigated,aiming to provide an experimental foundation for achieving a balance between their thermal and mechanical properties.Compacted graphite iron brake discs with different tensile strengths,macrohardnesses,specific heat capacities and thermal diffusion coefficients were produced by changing the proportion and strength of ferrite.The peak temperature,pressure load and friction coefficient of compacted graphite iron brake discs were analyzed through inertia friction tests.The morphology of thermal cracks and 3D profiles of the worn surfaces were also discussed.It is found that the thermal fatigue of compacted graphite iron discs is determined by their thermal properties.A compacted graphite iron with the highest specific heat capacity and thermal diffusion coefficient exhibits optimal thermal fatigue resistance.Oxidization of the matrix at low temperatures significantly weakens the function of alloy strengthening in hindering the propagation of thermal cracks.Despite the reduced hardness,increasing the ferrite proportion can mitigate wear loss resulting from low disc temperatures and the absence of abrasive wear.

Identifying relevant factors influencing cancer-related fatigue in patients with diffuse large B-cell lymphoma during chemotherapy

BACKGROUND Diffuse large B-cell lymphoma(DLBCL)is a rapidly growing malignant tumor,and chemotherapy is one of the treatments used to combat it.Although advancements of science and technology have resulted in more and more patients being able to receive effective treatment,they still face side effects such as fatigue and weakness.It is important to thoroughly investigate the factors that contribute to cancer-related fatigue(CRF)during chemotherapy.AIM To explore the factors related to CRF,anxiety,depression,and mindfulness levels in patients with DLBCL during chemotherapy.METHODS General information was collected from the electronic medical records of eligible patients.Sleep quality and mindfulness level scores in patients with DLBCL during chemotherapy were evaluated by the Pittsburgh Sleep Quality Index and Five Facet Mindfulness Questionnaire-Short Form.The Piper Fatigue Scale was used to evaluate the CRF status.The Self-Rating Anxiety Scale and Self-Rating Depression Scale were used to evaluate anxiety and depression status.Univariate analysis and multivariate regression analysis were used to investigate the factors related to CRF.RESULTS The overall average CRF level in 62 patients with DLBCL during chemotherapy was 5.74±2.51.In 25 patients,the highest rate of mild fatigue was in the cognitive dimension(40.32%),and in 35 patients the highest moderate fatigue rate in the behavioral dimension(56.45%).In the emotional dimension,severe fatigue had the highest rate of occurrence,34 cases or 29.03%.The CRF score was positively correlated with cancer experience(all P<0.01)and negatively correlated with cancer treatment efficacy(all P<0.01).Tumor staging,chemotherapy cycle,self-efficacy level,and anxiety and depression level were related to CRF in patients with DLBCL during chemotherapy.CONCLUSION There was a significant correlation between CRF and perceptual control level in patients.Tumor staging,chemotherapy cycle,self-efficacy level,and anxiety and depression level influenced CRF in patients with DLBCL during chemotherapy.

Integrated causal inference modeling uncovers novel causal factors and potential therapeutic targets of Qingjin Yiqi granules for chronic fatigue syndrome

Objective:Chronic fatigue syndrome(CFS)is a prevalent symptom of post-coronavirus disease 2019(COVID-19)and is associated with unclear disease mechanisms.The herbal medicine Qingjin Yiqi granules(QJYQ)constitute a clinically approved formula for treating post-COVID-19;however,its potential as a drug target for treating CFS remains largely unknown.This study aimed to identify novel causal factors for CFS and elucidate the potential targets and pharmacological mechanisms of action of QJYQ in treating CFS.Methods:This prospective cohort analysis included 4,212 adults aged≥65 years who were followed up for 7 years with 435 incident CFS cases.Causal modeling and multivariate logistic regression analysis were performed to identify the potential causal determinants of CFS.A proteome-wide,two-sample Mendelian randomization(MR)analysis was employed to explore the proteins associated with the identified causal factors of CFS,which may serve as potential drug targets.Furthermore,we performed a virtual screening analysis to assess the binding affinity between the bioactive compounds in QJYQ and CFS-associated proteins.Results:Among 4,212 participants(47.5%men)with a median age of 69 years(interquartile range:69–70 years)enrolled in 2004,435 developed CFS by 2011.Causal graph analysis with multivariate logistic regression identified frequent cough(odds ratio:1.74,95%confidence interval[CI]:1.15–2.63)and insomnia(odds ratio:2.59,95%CI:1.77–3.79)as novel causal factors of CFS.Proteome-wide MR analysis revealed that the upregulation of endothelial cell-selective adhesion molecule(ESAM)was causally linked to both chronic cough(odds ratio:1.019,95%CI:1.012–1.026,P=2.75 e^(−05))and insomnia(odds ratio:1.015,95%CI:1.008–1.022,P=4.40 e^(−08))in CFS.The major bioactive compounds of QJYQ,ginsenoside Rb2(docking score:−6.03)and RG4(docking score:−6.15),bound to ESAM with high affinity based on virtual screening.Conclusions:Our integrated analytical framework combining epidemiological,genetic,and in silico data provides a novel strategy for elucidating complex disease mechanisms,such as CFS,and informing models of action of traditional Chinese medicines,such as QJYQ.Further validation in animal models is warranted to confirm the potential pharmacological effects of QJYQ on ESAM and as a treatment for CFS.

Effect of Individualized Exercise Therapy on Cancer-related Fatigue and Negative Emotion in Patients with Gastrointestinal Tumor during Perioperative Period

[Objectives]To investigate the effect of exercise therapy in gastric cancer patients during perioperative period.[Methods]100 patients with gastric cancer who underwent elective operation in the Department of Gastrointestinal Surgery of Taihe Hospital Affiliated to Hubei University of Medicine were divided into observation group and control group by convenience sampling.The control group received routine nursing measures,and the experimental group received exercise therapy intervention measures on the basis of the control group.The patients were evaluated by the General Information Questionnaire,Self-Rating Anxiety Scale,Self-Rating Depression Scale and Cancer-related Fatigue Scale at the time of admission,the second week and the sixth week after operation.[Results]The time effect,intervention effect and interaction effect of anxiety score,depression score and cancer-related fatigue score were significant(all P<0.05)and the index of enhanced recovery after surgery was significant(P<0.05)in the two groups at the second and sixth week after operation.[Conclusions]Exercise therapy is beneficial to promoting the enhanced recovery after surgery in advance,reduce cancer-related fatigue,negative emotion and accelerate rehabilitation in patients with gastrointestinal tumors.

Effects of relaxation breathing exercise on fatigue and cortisol level among Indonesian gynecological cancer patients undergoing chemotherapy:a pilot study

Objective:This study aimed to determine the effect of the relaxation breathing exercise(RBE)on fatigue and cortisol levels among Indonesian women with gynecological cancer undergoing chemotherapy.Methods:This pilot study consecutively recruited 44 gynecological cancer patients to receive RBE(22)or usual care(22).Cortisol level was measured before and after completion of the intervention(day 8).Fatigue was measured using the Piper Fatigue Scale(PFS).Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale(HADS)at the baseline days of the study for days 1,4,and 8.The obtained data were analyzed using Fisher’s exact test,the independent t-test,and the Mann-Whitney U test.Results:There were significant increases in cortisol levels within the groups,either the intervention or control groups,respectively(P-value=0.0003 and 0.001).Despite there being no statistical significance between the intervention and control groups,there were noticeable differences in the cortisol levels,indicating the extreme increase in cortisol levels in the control group(Median[IQR1-IQR3]:2.30[0.99-9.09];Min-Max:0.43-23.38)compared with the intervention group(Median[IQR1-IQR3]=2.97[1.26-5.18];Min-Max=0.39-6.91).Conclusions:RBE helps prevent a significant increase in cortisol levels that can alleviate fatigue for women with gynecological cancer.Further research was recommended to compare several intervention modalities for fatigue and cancer-related symptom management based on cortisol level changes.

Frequency Domain Fatigue Evaluation on SCR Girth-Weld Based on Structural Stress

The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating platform.The harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue failure.The structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue evaluation.Here,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural stress.Besides,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into account.The research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.

Impact of comorbid subthreshold depressive symptoms on cancerrelated fatigue and complications in adults with leukemia

BACKGROUND Patients not only experience symptoms caused by cancer but also suffer from the accompanying psychological pain.Therefore,these patients do not have high quality of life.According to the World Health Organization,the incidence of leukemia in China in 2020 was 5.1/100000,the mortality rate was 3.3/100000,and the prevalence rate was 16.7/100000.Therefore,it is important to examine the influence of comorbid subthreshold depressive symptoms on leukemia patients.AIM To determine the impact of comorbid subthreshold depressive symptoms on cancer-related fatigue and complications in leukemia patients,thereby providing a basis for early diagnosis and treatment in clinical practice.METHODS A questionnaire survey was conducted among leukemia patients admitted to a tertiary hospital in Xi'an,Shaanxi Province,China,from August 2022 to December 2023.Patients with a score>16 on the Chinese Classification of Mental Disorders(CCMD-3)and a Hamilton Depression Rating Scale score of 8-17 were classified as the subthreshold depressive group(n=95),while 100 leukemia patients admitted during the same period were classified as the control group.Data were collected using Epidata 3.1 software,and comparisons were made between the two groups regarding general clinical data,the Piper Fatigue Scale(PFS),the Pittsburgh Sleep Quality Index(PSQI),the Numeric Rating Scale for pain assessment,laboratory indicators,and the occurrence of complications.RESULTS In this survey,120 leukemia patients with depression were preliminarily screened,95 patients with subthreshold depression were ultimately selected as the subthreshold depression group,and 100 leukemia patients admitted during the same period were enrolled as the normal group.Comparison of basic clinical data between the two groups revealed no significant differences in age,sex,body mass index,cognitive function,or comorbidity with other chronic diseases.However,there were statistically significant differences in the use of radiotherapy and regular exercise between the two groups(P<0.05).Comparisons of scales and laboratory indicators revealed no significant differences in albumin or PSQI scores between the two groups,but there were statistically significant differences in pain scores,PSQI scores,PFS scores,hemoglobin levels,and C-reactive protein levels(P<0.05).Spearman’s correlation analysis indicated that cancer-related fatigue was correlated with age,hemoglobin levels,C-reactive protein levels,pain,and regular exercise among leukemia patients with subthreshold depression.Multivariate regression analysis revealed that advanced age,combined radiotherapy,pain,and low hemoglobin levels were risk factors for cancer-related fatigue in leukemia patients with comorbid subthreshold depression,while regular exercise was a protective factor against cancer-related fatigue.Follow-up comparisons revealed a significantly lower overall incidence of complications in the control group(4%)than in the depressive group(24.21%;P<0.001).CONCLUSION Leukemia patients with comorbid subthreshold depressive symptoms experience more severe cancer-related fatigue and a higher incidence of complications.These findings may be related to advanced age,combined radiotherapy,pain,and low hemoglobin levels,while regular exercise may effectively alleviate symptoms.

A comparative study of the anti-fatigue activity of extracts from different parts of Cistanche tubulosa(Schenk)Wight

Objective:To evaluate the anti-fatigue effects of different extracts from Cistanche tubulosa(Schenk)Wight(C.tubulosa,Rou Cong Rong),focusing on central and exercise-induced fatigue in mice.This study investigated the pharmacological effects of the total oligosaccharides,polysaccharides,and phenylethanoid glycosides(CPhGs)extracted from C.tubulosa.Methods: Models of sleep deprivation and forced swimming fatigue were established to simulate central and exercise-induced fatigue.The mice were treated with different extracts of C.tubulosa,and their effects were assessed using behavioral tests to measure exercise capacity,learning,and memory function.Biochemical analyses were performed to evaluate the changes in serum and brain neurotransmitter levels,liver and muscle glycogen storage,and various fatigue-related biomarkers.Results: This study found that treatment with C.tubulosa extract improved exercise capacity,learning,and memory in mice.Total oligosaccharides from C.tubulosa enhanced adrenocorticotropic hormone,cholinesterase,and thyroid-stimulating hormone levels,reduced cortisol levels in central fatigue models,and ameliorated biochemical markers of exercise-induced fatigue,including lowering lactic acid,blood urea nitrogen,and malondialdehyde levels.Among the tested extracts,the total oligosaccharides showed the most comprehensive anti-fatigue effects.Conclusion: The anti-fatigue effects of C.tubulosa,particularly those of its total oligosaccharides,are pronounced in both central and exercise-induced fatigue.These effects are mediated by the regulation of neurotransmitter levels,enhancement of glycogen storage,and improvement of antioxidant enzyme activity,suggesting potential therapeutic benefits in fatigue-related conditions.

The Effect and Mechanism of Fructus lycii on Improvement of Exercise Fatigue Using a Network Pharmacological Approach with in vitro Experimental Verification

Objective This study aimed to investigate the effect and underlying mechanism of Fructus lycii in improving exercise fatigue.Methods A network pharmacological approach was used to explore potential mechanisms of action of Fructus lycii.Skeletal muscle C2C12 cells and immunofluorescence were employed to verify the effect and mechanism of the representative components in Fructus lycii predicted by network pharmacological analysis.Results Six potential active components,namely quercetin,β-sitosterol,stigmasterol,7-Omethylluteolin-6-C-beta-glucoside_qt,atropine,and glycitein,were identified to have potency in improving exercise fatigue via multiple pathways,such as the PI3K-Akt,neuroactive ligand-receptor interaction,IL-17,TNF,and MAPK signaling pathways.The immunofluorescence results indicated that quercetin,a significant active component in Fructus lycii,increased the mean staining area of 2-NBDG,TMRM,and MitoTracker,and decreased the area of CellRox compared to the control.Furthermore,the protein expression levels of p-38 MAPK,p-MAPK,p-JNK,p-PI3K,and p-AKT markedly increased after quercetin treatment.Conclusion Fructus lycii might alleviate exercise fatigue through multiple components and pathways.Among these,quercetin appears to improve exercise fatigue by enhancing energy metabolism and reducing oxidative stress.The PI3K-AKT and MAPK signaling pathways also appear to play a role in this process.

Effects of orientation on the fatigue crack growth behaviors of the ZK60 magnesium alloy in air and PBS

Strong anisotropic corrosion and mechanical properties caused by specimen orientations greatly limit the applications of wrought magnesium alloys.To investigate the influences of specimen orientation,the corrosion tests and(corrosion)fatigue crack growth tests were conducted.The rolled and transverse surfaces of the materials show distinct corrosion rate differences in the stable corrosion stage,but the truth is the opposite for the initial stage of corrosion.In air,specimen orientations have a significant influence on the plastic deformation mechanisms near the crack tip,which results in different fatigue fracture surfaces and cracking paths.Compared with R-T specimens,N-T specimens show a slower fatigue crack growth(FCG)rate in air,which can be attributed to crack closure effects and deformation twinning near the crack tip.The corrosion environment will not significantly change the main plastic deformation mechanisms for the same type of specimen.However,the FCG rate in phosphate buffer saline(PBS)is one order of magnitude higher than that in air,which is caused by the combined effects of hydrogen-induced cracking and anodic dissolution.Owing to the similar corrosion rates at crack tips,the specimens with different orientations display close FCG rates in PBS.

Research on Driver’s Fatigue Detection Based on Information Fusion

Driving fatigue is a physiological phenomenon that often occurs during driving.After the driver enters a fatigued state,the attentionis lax,the response is slow,and the ability todeal with emergencies is significantly reduced,which can easily cause traffic accidents.Therefore,studying driver fatigue detectionmethods is significant in ensuring safe driving.However,the fatigue state of actual drivers is easily interfered with by the external environment(glasses and light),which leads to many problems,such as weak reliability of fatigue driving detection.Moreover,fatigue is a slow process,first manifested in physiological signals and then reflected in human face images.To improve the accuracy and stability of fatigue detection,this paper proposed a driver fatigue detection method based on image information and physiological information,designed a fatigue driving detection device,built a simulation driving experiment platform,and collected facial as well as physiological information of drivers during driving.Finally,the effectiveness of the fatigue detection method was evaluated.Eye movement feature parameters and physiological signal features of drivers’fatigue levels were extracted.The driver fatigue detection model was trained to classify fatigue and non-fatigue states based on the extracted features.Accuracy rates of the image,electroencephalogram(EEG),and blood oxygen signals were 86%,82%,and 71%,separately.Information fusion theory was presented to facilitate the fatigue detection effect;the fatigue features were fused using multiple kernel learning and typical correlation analysis methods to increase the detection accuracy to 94%.It can be seen that the fatigue driving detectionmethod based onmulti-source feature fusion effectively detected driver fatigue state,and the accuracy rate was higher than that of a single information source.In summary,fatigue drivingmonitoring has broad development prospects and can be used in traffic accident prevention and wearable driver fatigue recognition.

A critical review of wheel/rail high frequency vibration-induced vibration fatigue of railway bogie in China

Purpose–This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.Design/methodology/approach–Vibration fatigue of railway bogie arising from the wheel/rail high frequency vibration has become the main concern of railway operators.Previous reviews usually focused on the formation mechanism of wheel/rail high frequency vibration.This paper thus gives a critical review of the vibration fatigue of railway bogie owing to the short-pitch irregularities-induced high frequency vibration,including a brief introduction of short-pitch irregularities,associated high frequency vibration in railway bogie,typical vibration fatigue failure cases of railway bogie and methodologies used for the assessment of vibration fatigue and research gaps.Findings–The results showed that the resulting excitation frequencies of short-pitch irregularity vary substantially due to different track types and formation mechanisms.The axle box-mounted components are much more vulnerable to vibration fatigue compared with other components.The wheel polygonal wear and rail corrugation-induced high frequency vibration is the main driving force of fatigue failure,and the fatigue crack usually initiates from the defect of the weld seam.Vibration spectrum for attachments of railway bogie defined in the standard underestimates the vibration level arising from the short-pitch irregularities.The current investigations on vibration fatigue mainly focus on the methods to improve the accuracy of fatigue damage assessment,and a systematical design method for vibration fatigue remains a huge gap to improve the survival probability when the rail vehicle is subjected to vibration fatigue.Originality/value–The research can facilitate the development of a new methodology to improve the fatigue life of railway vehicles when subjected to wheel/rail high frequency vibration.

Efficacy of ginseng-based Renshenguben oral solution for cancer-related fatigue among patients with advanced-stage hepatocellular carcinoma:A prospective multicenter cohort study

Background:Cancer-related fatigue(CRF)is a common and debilitating symptom experienced by patients with advanced-stage cancer,especially those undergoing antitumor therapy.This study aimed to evaluate the efficacy and safety of Renshenguben(RSGB)oral solution,a ginseng-based traditional Chinese medicine,in alleviating CRF in patients with advanced hepatocellular carcinoma(HCC)receiving antitumor treatment.Methods:In this prospective,open-label,controlled,multicenter study,patients with advanced HCC at BCLC stage C and a brief fatigue inventory(BFI)score of≥4 were enrolled.Participants were assigned to the RSGB group(RSGB,10 mL twice daily)or the control group(with supportive care).Primary and secondary endpoints were the change in multidimensional fatigue inventory(MFI)score,and BFI and functional assessment of cancer therapy-hepatobiliary(FACT-Hep)scores at weeks 4 and 8 after enrollment.Adverse events(AEs)and toxicities were assessed.Results:A total of 409 participants were enrolled,with 206 assigned to the RSGB group.At week 4,there was a trend towards improvement,but the differences were not statistically significant.At week 8,the RSGB group exhibited a significantly lower MFI score(P<0.05)compared to the control group,indicating improved fatigue levels.Additionally,the RSGB group showed significantly greater decrease in BFI and FACT-Hep scores at week 8(P<0.05).Subgroup analyses among patients receiving various antitumor treatments showed similar results.Multivariate linear regression analyses revealed that the RSGB group experienced a significantly substantial decrease in MFI,BFI,and FACT-Hep scores at week 8.No serious drug-related AEs or toxicities were observed.Conclusions:RSGB oral solution effectively reduced CRF in patients with advanced HCC undergoing antitumor therapy over an eight-week period,with no discernible toxicities.These findings support the potential of RSGB oral solution as an adjunctive treatment for managing CRF in this patient population.

Improving fatigue properties of normal direction ultrasonic vibration assisted face grinding Inconel 718 by regulating machined surface integrity

Fatigue properties are crucial for critical aero-engine components in extreme serviceenvironments,which are significantly affected by surface integrity(SI)indexes(especially surface topography,residual stressσ_(res),and microhardness)after machining processes.Normal-direction ultrasonic vibration-assisted face grinding(ND-UVAFG)has advantages in improving the machinability of Inconel 718,but there is a competitive relationship between higher compressiveσ_(res)and higher surface roughness R_(a)in affecting fatigue strength.The lack of a quantitative relationship between multiple SI indexes and fatigue strength makes theindeterminacy of a regulatory strategy for improving fatigue properties.In this work,a model of fatigue strength(σ_f)_(sur)considering multiple SI indexes was developed.Then,high-cycle fatigue tests were carried out on Inconel 718 samples with different SI characteristics,and the influence of ND-UVAFG process parameters on SI was analyzed.Based on SI indexes data,the(σ_f)_(sur)distribution in the grinding surface layer for ND-UVAFG Inconel 718 samples was determined using the developed model,and then the fatigue crack initiation(FCI)sites were furtherpredicted.The predicted FCI sites corresponded well with the experimental results,therebyverifying this model.A strategy for improving the fatigue life was proposed in this work,which was to transfer the fatigue source from the machined surface to the bulk material by controlling the SI indexes.Finally,a critical condition of SI indexes that FCI sites appeared on the surface or in bulk material was given by fitting the predicted results.According to the critical condition,an SI field where FCI sites appeared in the bulk material could be obtained.In this field,thefatigue life of Inconel 718 samples could be improved by approximately 140%.

Effects of Intermittent Hypoxia Exposure on Symptoms of Chronic Fatigue Syndrome in Repeated Restraint Stress and Forced Swimming Induced-Mouse Model

Background: Chronic fatigue syndrome (CFS) shows as its main symptoms debilitating fatigue that is not relieved by physiological rest, depression, inflammation, learning disability and memory impairment. But, intermittent hypoxia, consisting of alternating exposure to hypoxia and normoxia, plays a very important role in improving CFS. However, the essential components for improving learning and memory in CFS patients as well as their mechanism are largely unknown. Objectives: This study aims to analyze the effects of 12% and 15% hypoxia on the expression of alpha tumor necrosis factor (TNF-α) and nuclear factor kappa B (NF-κB) in CFS induced-mouse model for clarifying the effects on the learning and memory function. Methods: A total of 48 type IC mice were used. The CFS mouse model was established using restrained stress and repeated forced swimming. Treatment of CFS was done by exposing CFS mice to intermittent hypoxia at 12% and 15%. The effects of intermittent hypoxia on learning and memory as well as its mechanism of action on inflammation were tested respectively with the Morris test, the SDS page, the immunohistochemistry technique and the Nissl staining. Results: We found that 12% and 15% intermittent hypoxia exposure improved learning capacity and memory of CFS induced-mice. SDS page showed that CFS caused higher TNF-α expression. By exposing CFS mice to 12% and 15% intermittent hypoxia, TNF-α expression decreased significantly, with a much better effect at 15%. Both TNF-α and NF-κB increased in CFS state and decreased after treatment with intermittent hypoxia. Conclusion: Intermittent hypoxia improves learning capacity and memory. It acted by decreasing NF-κB come to down-regulating TNF-α and ameliorates learning capacity and memory impairment in CFS mice.

Fatigue Resistance of RCA Modified Asphalt Based on Dielectric Properties

In order to study the anti-fatigue performance of RCA modified asphalt (RMA),the performance of RMA and 90#matrix asphalt with different modifier content were measured by asphalt penetration,ductility,softening point,Brookfield viscosity,rheological index,infrared spectrum and dielectric constant test.This paper discusses the changes of asphalt basic indexes,fatigue properties and asphalt components based on dielectric properties under different modifier contents,and analyzes the grey correlation degree between components and asphalt pavement performance indexes.The results show that the optimum content of RCA modifier is 16.7%of the asphalt quality according to the penetration,ductility,softening point,Brockfield viscosity,viscosity temperature curve and fatigue life.In the phase angle-strain curve,there is disorder in the latter part of the curve.According to the strain (ε_(d)) corresponding to the disorder point,a new fatigue failure criterion is proposed and proved.Based on the new asphalt fatigue failure criterion,the fatigue prediction model of asphalt mixture is improved,and the fatigue life predicted by the improved fatigue model is compared with the fatigue life obtained by four-point bending fatigue test.The results show that the proposed new asphalt fatigue failure criterion is reasonable,and the fatigue life predicted by the improved asphalt mixture fatigue prediction model is accurate.The research method of classifying asphalt components based on dielectric properties is simple and effective,and the components have a high correlation with the road performance of base asphalt and modified asphalt.

Damage Evolution of Ballastless Track Concrete Exposed to Flexural Fatigue Loads:The Application of Ultrasonic Pulse Velocity,Impact-echo and Surface Electrical Resistance Method

In order to clarify the fatigue damage evolution of concrete exposed to flexural fatigue loads,ultrasonic pulse velocity(UPV),impact-echo technology and surface electrical resistance(SR) method were used.Damage variable based on the change of velocity of ultrasonic pulse(Du) and impact elastic wave(Di)were defined according to the classical damage theory.The influences of stress level,loading frequency and concrete strength on damage variable were measured.The experimental results show that Du and Di both present a three-stages trend for concrete exposed to fatigue loads.Since impact elastic wave is more sensitive to the microstructure damage in stage Ⅲ,the critical damage variable,i e,the damage variable before the final fracture of concrete of Di is slightly higher than that of Du.Meanwhile,the evolution of SR of concrete exposed to fatigue loads were analyzed and the relationship between SR and Du,SR and Di of concrete exposed to fatigue loads were established.It is found that the SR of concrete was decreased with the increasing fatigue cycles,indicating that surface electrical resistance method can also be applied to describe the damage of ballastless track concrete exposed to fatigue loads.

Anti-fatigue activity and mechanism of crocetin loaded nanoliposome in acute exercise-treated mice

Crocetin displays strong antioxidant,anti-inflammatory and anti-depression activity which is promising to relieve symptoms of fatigue.As a carotenoid,crocetin is difficult to dissolve in water and highly unstable against many environmental factors.Nanoliposome is used to encapsulate crocetin to improve its water dispersion.In the present study,the antifatigue activities and potential mechanism of crocetin loaded nanoliposome(CLN)was extensively investigated.The potential antifatigue pathway of CLN was analyzed.Furthermore,impact of CLN on the gut microbiota structure was examined which contributes to its antifatigue functions.CLN significantly increases exhaustive swimming time of fatigue mice,decreases the blood contents of lactic,blood urea nitrogen(BUN)and malondialdehyde(MDA).At the same time,CLN improves the activity of glutathione peroxidase(GSH-Px)and succinate dehydrogenase(SDH)enzyme,attenuates the oxidant stress in mice.CLN activates the adenosine monophosphate-activated kinase(AMPK)/peroxisome proliferator-activated receptor gamma coactivator-1α(PGC-1α)signaling pathway of fatigue mice,increases the mRNA expression of ATP synthase.It also increases mRNA expression of mitochondrial transcription factor A(TFAM)which promotes mitochondrial biogenesis.Additionally,CLN ameliorates the gut microbiota structure by increasing the abundance of genus such as Lactobacillus in fatigue mice.In summary,CLN exerts strong anti-fatigue properties by decreasing the oxidant stress and the contents of harmful metabolites,augmenting the production of ATP,and potentially ameliorating the gut microbiota structure.

Low-cycle fatigue behavior of solutionized and aged WE43 magnesium alloys at room temperature

The low-cycle fatigue behavior of solutionized(T4)and aged(T6)WE43 magnesium alloys was studied at room temperature.The total strain amplitudes(△ε_(t)/2)were 0.4%,0.5%,0.6%,0.7%and 1.0%.Detailed microstructure evolution was characterized by scanning electron microscope(SEM),electron backscattered diffraction(EBSD)and transmission electron microscopy(TEM).The results showed that plastic strain amplitude decreased with the increasing cycle number in T4 alloy,which is due to the dense persistent slip bands(PSBs)and dynamic precipitates hinderingdislocation slip.In contrast,the plastic strain amplitude increases gradually in T6 alloy,which is attributed to the enhanced activation of pyramidal slip.The low-cycle fatigue life of T6 alloy with larger fatigue ductility coefficient is longer than that of T4 alloy.The Coffin-Manson model can accurately predict the fatigue life of T4 and T6 alloys compared to Jahed-Varvani(JV)energy model.For T4 alloy,the fatigue damage mechanism was dominated by basal slip.For T6 alloy,the enhanced pyramidal slip plays an important role to accommodate plastic deformation.

Influence of transcatheter arterial embolization on symptom distress and fatigue in liver cancer patients

BACKGROUND Hepatocellular carcinoma(HCC)is a prevalent malignancy,and transcatheter arterial embolization(TAE)has emerged as a pivotal therapeutic modality.How-ever,TAE may induce symptom distress and fatigue,adversely affecting the quality of life of patients.AIM To investigate symptom distress,fatigue,and associated factors in HCC patients undergoing TAE.METHODS We used a cross-sectional design and purposive sampling to enroll HCC patients who underwent TAE at our institution from January to December 2022.Question-naires were utilized to collect data on symptom distress and fatigue scores from the first to the third day after TAE.RESULTS Our study revealed a significant reduction in fatigue and symptom distress among patients after TAE.Pain,fatigue,insomnia,fever and abdominal dis-tension were the most common symptoms troubling patients during the first 3 d post-TAE.Marital status,presence of family support,physical functional status,age,and symptom distress were identified as predictors of fatigue in patients.CONCLUSION Healthcare professionals should educate HCC patients on symptom distress and INTRODUCTION Hepatocellular carcinoma(HCC)ranks as the fifth most prevalent cancer and the third leading cause of cancer-related mortality globally.Surgical intervention remains the cornerstone of HCC treatment;however,due to the challenges associated with early diagnosis and the lack of specific diagnostic markers,a considerable proportion of patients are diagnosed at advanced stages,rendering them ineligible for surgical interventions.Transcatheter arterial embolization(TAE)is an interventional therapeutic approach involving the insertion of a fine catheter via the femoral artery to reach the vasculature near the tumor site.TAE aims to obstruct the arterial supply to the tumor by deploying embolic agents,thereby inducing necrosis in cancer cells.This procedure is suitable for patients with good liver function and overall health,particularly those with large HCCs that have not invaded the portal vein[1,2].Nonetheless,following TAE,hepatocytes incur variable degrees of damage,leading to the development of a constel-lation of symptoms reminiscent of acute hepatitis.These symptoms include fatigue and systemic discomfort,such as nausea,vomiting,fever,abdominal pain,as well as transient elevations in aspartate aminotransferase(AST)and alanine aminotransferase(ALT),collectively referred to as postembolization syndrome[3,4].These symptoms may arise due to ischemia of the liver and gallbladder,temporary liver enlargement,and peritoneal irritation.While many studies have explored fatigue and symptom distress in cancer patients both nationally and internationally,with some focusing on symptom distress following transcatheter arterial chemoembolization,there has been limited in-depth investigation into the fatigue and symptom distress resulting from TAE treatment[5-8].Fatigue and pain are both subjective experiences,typically arising from the gradual depletion of energy reserves during the course of illness[9].Fatigue is particularly prevalent among cancer patients,with rates soaring as high as 90%.Despite extensive research exploring cancer-related fatigue and its influencing factors,a unanimous consensus remains elusive.Hence,the primary objective of this study was to investigate the symptom distress and fatigue experienced by liver cancer patients following TAE treatment and to analyze potential contributing factors.