Labour analgesia effects on foetal heart rate. A mini-review

Foetal well-being during labour is of utmost importance. One of the ways to attempt to assess foetal well-being is by recording foetal heart rate (FHR). Loss of variability and deceleration patterns are known to be associated with foetal distress. Decelerations and foetal bradycardia have been described after any type of effective labour analgesia. This review addresses the questions if certain analgesic techniques and/or analgesics lead to clinically relevant FHR changes, what is their aetiology, and how we should manage these FHR changes.

Video-Based Deception Detection with Non-Contact Heart Rate Monitoring and Multi-Modal Feature Selection

Deception detection plays a crucial role in criminal investigation.Videos contain a wealth of information regarding apparent and physiological changes in individuals,and thus can serve as an effective means of deception detection.In this paper,we investigate video-based deception detection considering both apparent visual features such as eye gaze,head pose and facial action unit(AU),and non-contact heart rate detected by remote photoplethysmography(rPPG)technique.Multiple wrapper-based feature selection methods combined with the K-nearest neighbor(KNN)and support vector machine(SVM)classifiers are employed to screen the most effective features for deception detection.We evaluate the performance of the proposed method on both a self-collected physiological-assisted visual deception detection(PV3D)dataset and a public bag-oflies(BOL)dataset.Experimental results demonstrate that the SVM classifier with symbiotic organisms search(SOS)feature selection yields the best overall performance,with an area under the curve(AUC)of 83.27%and accuracy(ACC)of 83.33%for PV3D,and an AUC of 71.18%and ACC of 70.33%for BOL.This demonstrates the stability and effectiveness of the proposed method in video-based deception detection tasks.

Quran memorisation and heart rate variability:How do they correlate?

BACKGROUND Heart rate variability(HRV)was shown to be affected by performing religious activities.AIM To examine the relationship between the level of Quran(the holy book of Muslims)memorisation and HRV among teenagers.METHODS This experimental study included 16 Tahfiz students and 16 non-Tahfiz students(n=32).The HRV was measured in three tasks:Recalling familiar verses,memorising new verses,and recalling the newly memorised verses of the Quran.HRV analysis was done using these parameters:Standard deviation of N-N(heartbeat peak)interval;low frequency(LF);high frequency(HF)and LF/HF ratio.RESULTS There were significant differences between tasks for all parameters(P<0.05).However,between the groups,only the LF/HF ratio had significant differences,with F=5.04,P<0.05.Pearson correlation showed a moderate positive correlation between the number of pages memorised and the LF/HF ratio(r=0.61,P<0.05).CONCLUSION Quran memorisation increased the HRV and our results suggested that this activity could be developed as an effective sympathovagal modulation training activity.

A comprehensive review of heart rate variability as an indicator in the regulation of the autonomic nervous system by acupuncture:a bibliometric analysis

This study sought to conduct a bibliometric analysis of acupuncture studies focusing on heart rate variability(HRV)and to investigate the correlation between various acupoints and their effects on HRV by utilizing association rule mining and network analysis.A total of 536 publications on the topic of acupuncture studies based on HRV.The disease keyword analysis revealed that HRV-related acupuncture studies were mainly related to pain,inflammation,emotional disorders,gastrointestinal function,and hypertension.A separate analysis was conducted on acupuncture prescriptions,and Neiguan(PC6)and Zusanli(ST36)were the most frequently used acupoints.The core acupoints for HRV regulation were identified as PC6,ST36,Shenmen(HT7),Hegu(LI4),Sanyinjiao(SP6),Jianshi(PC5),Taichong(LR3),Quchi(LI11),Guanyuan(CV4),Baihui(GV20),and Taixi(KI3).Additionally,the research encompassed 46 reports on acupuncture animal experiments conducted on HRV,with ST36 being the most frequently utilized acupoint.The research presented in this study offers valuable insights into the global research trend and hotspots in acupuncture-based HRV studies,as well as identifying frequently used combinations of acupoints.The findings may be helpful for further research in this field and provide valuable information about the potential use of acupuncture for improving HRV in both humans and animals.

TCM-HIN2Vec:A strategy for uncovering biological basis of heart qi deficiency pattern based on network embedding and transcriptomic experiment

Objective To elucidate the biological basis of the heart qi deficiency(HQD)pattern,an in-depth understanding of which is essential for improving clinical herbal therapy.Methods We predicted and characterized HQD pattern genes using the new strategy,TCM-HIN2Vec,which involves heterogeneous network embedding and transcriptomic experiments.First,a heterogeneous network of traditional Chinese medicine(TCM)patterns was constructed using public databases.Next,we predicted HQD pattern genes using a heterogeneous network-embedding algorithm.We then analyzed the functional characteristics of HQD pattern genes using gene enrichment analysis and examined gene expression levels using RNA-seq.Finally,we identified TCM herbs that demonstrated enriched interactions with HQD pattern genes via herbal enrichment analysis.Results Our TCM-HIN2Vec strategy revealed that candidate genes associated with HQD pattern were significantly enriched in energy metabolism,signal transduction pathways,and immune processes.Moreover,we found that these candidate genes were significantly differentially expressed in the transcriptional profile of mice model with heart failure with a qi deficiency pattern.Furthermore,herbal enrichment analysis identified TCM herbs that demonstrated enriched interactions with the top 10 candidate genes and could potentially serve as drug candidates for treating HQD.Conclusion Our results suggested that TCM-HIN2Vec is capable of not only accurately identifying HQD pattern genes,but also deciphering the basis of HQD pattern.Furthermore our finding indicated that TCM-HIN2Vec may be further expanded to develop other patterns,leading to a new approach aimed at elucidating general TCM patterns and developing precision medicine.

Postpartum quality of life and mental health in women with heart disease:Integrated clinical communication and treatment

BACKGROUND Postpartum quality of life(QoL)in women with heart disease has been neglected.AIM To improve clinical communication and treatment,we integrated medical data and subjective characteristics to study postpartum QoL concerns.METHODS The study assessed QoL 6 wk after birth using the 12-Item Short-Form Health Survey.The Edinburgh Postnatal Depression Scale,Cardiac Anxiety Questionnaire,European Heart Failure Self-Care Behavior Scale,and a self-designed questionnaire based on earlier research were also used to assess patient characteristics.Patient data were collected.Prediction models were created using multiple linear regression.RESULTS This retrospective study examined postpartum QoL in 105 cardiac patients.Postpartum QoL scores were lower(90.69±13.82)than those of women without heart disease,with physical component scores(41.09±9.91)lower than mental component scores(49.60±14.87).Postpartum depression(33.3%),moderate anxiety(37.14%),pregnancy concerns(57.14%),offspring heart problems(57.14%),and life expectancy worries(48.6%)were all prevalent.No previous cardiac surgery,multiparity,higher sadness and cardiac anxiety,and fear of unfavorable pregnancy outcomes were strongly related to lower QoL(R^(2)=0.525).CONCLUSION Postpartum QoL is linked to physical and mental health in women with heart disease.Our study emphasizes the need for healthcare workers to recognize the unique characteristics of these women while developing and implementing comprehensive management approaches during their maternity care.

Chlorogenic acid ameliorates heart failure by attenuating cardiomyocyte ferroptosis Author links open overlay panel

Objective To elucidate the effects of chlorogenic acid(CGA),a bioactive polyphenol compound prevalent in traditional Chinese medicine and various foods,including Lonicera japonica Thunb.(Jin Yin Hua),Eucommia ulmoides Oliv.(Du Zhong Ye),tea,and coffee,on cardiomyocyte ferroptosis and heart failure.Methods We assessed the effect of CGA on cardiac function using a mouse model of heart failure induced by transverse aortic constriction(TAC).These indicators included the left ventricular ejection fraction(LVEF),fractional shortening(LVFS),end-systolic volume(LVESV),end-diastolic volume(LVEDV),end-systolic diameter(LVESD),and end-diastolic diameter(LVEDD).An isoprenaline hydrochloride(ISO)-induced H9c2 cardiomyocyte cell model was also established,and the cells were treated with various concentrations of CGA.To assess the effect of CGA on ferroptosis in cardiomyocytes,we measured cell viability and evaluated the levels of intracellular reactive oxygen species(ROS),ferrous ions(Fe^(2+)),and lipid peroxidation using fluorescent staining.To clarify the ferroptosis signaling pathway regulated by CGA,western blotting was used to examine the expression of ferroptosis biomarkers,specifically solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),in H9c2 cardiomyocytes and mouse myocardial tissues.Results CGA significantly enhanced cardiac performance indices such as LVEF,LVFS,LVESV,LVEDV,LVESD,and LVEDD.H9c2 cardiomyocytes exposed to ISO showed decreased cell viability and increased ROS levels,Fe^(2+)content,and lipid peroxidation levels.However,CGA treatment significantly ameliorated these changes.Additionally,in both H9c2 cardiomyocytes and myocardial tissue obtained from mice with TAC,CGA increased the expression of ferroptosis-related proteins,including SLC7A11 and GPX4.Conclusion CGA has the potential to enhance cardiac function and diminish lipid peroxidation and ROS levels in cardiomyocytes via the SLC7A11/GPX4 signaling pathway.This process alleviates ferroptosis in cardiomyocytes.These results provide new insights into the clinical use of CGA and the management of heart failure.

Application Value of NLR,PLR,LMR,HEART score,and POCT in Early Warning and Accurate Graded Diagnosis of High-Risk Chest Pain in Emergency Medicine

Objective: To evaluate the application value of neutrophils/lymphocytes (NLR), platelets/lymphocytes (PLR), lymphocytes/monocytes (LMR), HEART (history, electrocardiogram, age, risk factors, and troponin) score, and point-of- care testing (POCT) in the early warning and precise diagnosis of high-risk chest pain in emergency medicine. Methods: A total of 157 patients with acute chest pain who were admitted to the emergency department and chest pain treatment unit of our hospital between August 2022 and September 2023 were selected. Rapid testing of bedside myocardial markers (ultrasensitive troponin (hs-cTnI), myoglobin (MYO), creatine kinase isoenzyme (CK-MB), D-dimer (D-Dimer), and N-terminal B-type natriuretic peptide precursor (NT-proBNP)) was performed on the patients using a POCT device (ThermoKing BioMQ60proB). A HEART score was used to classify the patients into low (n = 53), intermediate (n = 59), and high-risk (n = 45) groups, and the NLR, PLR, and LMR were calculated. The NLR, PLR, and LMR values were compared among the three groups of patients, and the optimal cutoff values as well as sensitivity and specificity were determined based on receiver operating characteristic (ROC) analysis. Results: The HEART scores of patients in the low-risk, intermediate-risk, and high-risk groups were (2.72 ± 0.24), (4.75 ± 0.56), and (5.32 ± 0.73) respectively, and the differences were statistically significant (P < 0.05). Compared with the low-risk group, the intermediate-risk group and high-risk group had a significantly higher NLR and PLR, and a significantly lower LMR;the high-risk group had higher NLR and PLR and lower values of LMR as compared to the other two groups, and the difference was statistically significant (P < 0.05). The ROC curves suggested that the area under the curve, sensitivity, and specificity of the combined diagnosis of NLR, PLR, LMR, HEART score, and POCT were greater than those of LR, PLR, and LMR with HEART score and POCT alone. Conclusion: The combined application of NLR, PLR, LMR, HEART score, and POCT has significant application value in the early warning and precise diagnosis of emergency high-risk chest pain. It provides a more simple, easy-to-access, and efficient assessment index for the clinical prediction and treatment of emergency high- risk chest pain.

Gene polymorphisms associated with sudden decreases in heart rate during extensive peritoneal lavage with distilled water after gastrectomy

BACKGROUND Our previous study found that the telomerase-associated protein 1(TEP1,rs938886 and rs1713449)and homo sapiens RecQ like helicase 5(RECQL5,rs820196)single nucleotide polymorphisms(SNPs)were associated with changes in heart rate(HR)≥30%during peritoneal lavage with distilled water after gastrectomy.This study established a single tube method for detecting these three SNPs using two-dimensional(2D)polymerase chain reaction(PCR),and investigated whether SNP-SNP and SNP-environment interactions increase the risk of high HR variability(HRV).AIM To investigate whether genotypes,genetic patterns,SNP-SNP and SNP-environment interactions were associated with HRV.METHODS 2D PCR was used to establish a single-tube method to detect TEP1 rs938886 and rs1713449 and RECQL5 rs820196,and the results were compared with those of sanger sequencing.After adjusting for confounders such as age,sex,smoking,hypertension,and thyroid dysfunction,a nonconditional logistic regression model was used to assess the associations between the genotypes and the genetic patterns(codominant,dominant,overdominant,recessive,and additive)of the three SNPs and a risk≥15%or≥30%of a sudden drop in HR during postoperative peritoneal lavage in patients with gastric cancer.Gene-gene and geneenvironment interactions were analyzed using generalized multifactor dimensionality reduction.RESULTS The coincidence rate between the 2D PCR and sequencing was 100%.When the HRV cutoff value was 15%,the patients with the RECQL5(rs820196)TC genotype had a higher risk of high HRV than those who had the TT genotype(odds ratio=1.97;95%CI:1.05-3.70;P=0.045).Under the codominant and overdominant models,the TC genotype of RECQL5(rs820196)was associated with a higher risk of HR decrease relative to the TT and TT+CC genotypes(P=0.031 and 0.016,respectively).When the HRV cutoff value was 30%,patients carrying the GC-TC genotypes of rs938886 and rs820196 showed a higher HRV risk when compared with the GG–TT genotype carriers(P=0.01).In the three-factor model of rs938886,rs820196,and rs1713449,patients carrying the GC-TC-CT genotype had a higher risk of HRV compared with the wild-type GG-TT-CC carriers(P=0.01).For rs820196,nonsmokers with the TC genotype had a higher HRV risk compared with nonsmokers carrying the TT genotype(P=0.04).When the HRV cutoff value was 15%,patients carrying the TT-TT and the TC-CT genotypes of rs820196 and rs1713449 showed a higher HRV risk when compared with TT-CC genotype carriers(P=0.04 and 0.01,respectively).Patients carrying the GC-CT-TC genotypes of rs938886,rs1713449,and rs820196 showed a higher HRV risk compared with GG-CC-TT genotype carriers(P=0.02).When the HRV cutoff value was 15%,the best-fitting models for the interactions between the SNPs and the environment were the rs820196-smoking(P=0.022)and rs820196-hypertension(P=0.043)models.Consistent with the results of the previous grouping,for rs820196,the TC genotype nonsmokers had a higher HRV risk compared with nonsmokers carrying the TT genotype(P=0.01).CONCLUSION The polymorphism of the RECQL5 and TEP1 genes were associated with HRV during peritoneal lavage with distilled water after gastrectomy.

Pulse rate estimation based on facial videos:an evaluation and optimization of the classical methods using both self-constructed and public datasets

Pulse rate is one of the important characteristics of traditional Chinese medicine pulse diagnosis,and it is of great significance for determining the nature of cold and heat in diseases.The prediction of pulse rate based on facial video is an exciting research field for getting palpation information by observation diagnosis.However,most studies focus on optimizing the algorithm based on a small sample of participants without systematically investigating multiple influencing factors.A total of 209 participants and 2,435 facial videos,based on our self-constructed Multi-Scene Sign Dataset and the public datasets,were used to perform a multi-level and multi-factor comprehensive comparison.The effects of different datasets,blood volume pulse signal extraction algorithms,region of interests,time windows,color spaces,pulse rate calculation methods,and video recording scenes were analyzed.Furthermore,we proposed a blood volume pulse signal quality optimization strategy based on the inverse Fourier transform and an improvement strategy for pulse rate estimation based on signal-to-noise ratio threshold sliding.We found that the effects of video estimation of pulse rate in the Multi-Scene Sign Dataset and Pulse Rate Detection Dataset were better than in other datasets.Compared with Fast independent component analysis and Single Channel algorithms,chrominance-based method and plane-orthogonal-to-skin algorithms have a more vital anti-interference ability and higher robustness.The performances of the five-organs fusion area and the full-face area were better than that of single sub-regions,and the fewer motion artifacts and better lighting can improve the precision of pulse rate estimation.

Study on Real-Time Heart Rate Detection Based on Multi-People

Heart rate is an important vital characteristic which indicates physical and mental health status.Typically heart rate measurement instruments require direct contact with the skin which is time-consuming and costly.Therefore,the study of non-contact heart rate measurement methods is of great importance.Based on the principles of photoelectric volumetric tracing,we use a computer device and camera to capture facial images,accurately detect face regions,and to detect multiple facial images using a multi-target tracking algorithm.Then after the regional segmentation of the facial image,the signal acquisition of the region of interest is further resolved.Finally,frequency detection of the collected Photo-plethysmography(PPG)and Electrocardiography(ECG)signals is completed with peak detection,Fourier analysis,and a Waveletfilter.The experimental results show that the subject’s heart rate can be detected quickly and accurately even when monitoring multiple facial targets simultaneously.

基于SHERPA和HEART的老年人车载信息系统界面设计研究

目的改善老年驾驶员对车载信息系统界面的使用体验。方法提出基于SHERPA(系统人为错误减少与预测方法)和HEART(人误评估与减少技术)的老年人车载信息系统界面设计研究方法。首先,成立焦点小组对评估界面进行SHERPA定性分析,绘制车载信息系统界面层次任务分析图,通过错误分类表定义错误类型;其次,运用HEART定量分析错误类型,设定差错诱发条件,确定各条件的影响评估比例,从而计算人误概率;最后,在此基础上,分析差错诱发条件,归纳差错发生原因,根据差错纠正措施进行设计改良,对改良界面进行结果验证。结论该方法可以有效发现与老年人车载信息系统界面显著相关的差错诱发条件,既可帮助设计师找到交互设计改良的重点,也可减少老年驾驶员对车载信息系统界面的误操作情况。

Heart Rate Variability as an Indicator of Stress in Students’ Athletes

Introduction: The wellbeing of student’s athletes has a paramount importance, a prolonged period of cognitive and physical performance that characterizes the life of student’s athletes often leads to fatigue, and a psychobiological state that increases the risk of injury and accidents. The use of Heart rate variability (HRV) has become increasingly popular as a non-invasive methodology that provides an indirect insight into the autonomic nervous system. HRV can be utilized as a diagnostic tool in detection of autonomic nervous system impairment and sympatho-vagal imbalance. HRV technology is employed to monitor the internal response of athletes to workload and identify athletes’s psychophysical stress to predict and therefore prevent injuries. Objective: The objective of the investigation is to establish whether the use of Polar H10 sensor heart rate monitors worn by athletes in a sitting position (inclination 60 degrees) during periods characterized by stress can provide a valid and non-invasive method to assess the psychophysiological state during sports competition and school exams. Method and Statistics: In the study, the HRV of 12 basketball students athletes and 4 students non-athletes was analyzed as a control group. The autonomic nervous system activity was assessed based on heart variability parameters (HRV): SDNN, rMSSD, LF, HF, and LF/HF. The measurements were made after establishing the baseline at rest, during the training phase (CT), competition phase (CC) and during the acute phase of stressors due to school exams coinciding with the competitive season (CC + E). Results: Compared to the respective values prior to the stress of the competitions and exams, a significant decrease in HRV indices was found: SDNN (P Conclusions: The analysis and examination of the data on the sample of the student population also showed a statistically significant correlation between decreased cardiac variability and injuries or indisposition to physical exertion.

Targeting epicardial adipose tissue:A potential therapeutic strategy for heart failure with preserved ejection fraction with type 2 diabetes mellitus

Heart failure with preserved ejection fraction(HFpEF)is a heterogeneous syndrome with various comorbidities,multiple cardiac and extracardiac pathophysiologic abnormalities,and diverse phenotypic presentations.Since HFpEF is a heterogeneous disease with different phenotypes,individualized treatment is required.HFpEF with type 2 diabetes mellitus(T2DM)represents a specific phenotype of HFpEF,with about 45%-50% of HFpEF patients suffering from T2DM.Systemic inflammation associated with dysregulated glucose metabolism is a critical pathological mechanism of HFpEF with T2DM,which is intimately related to the expansion and dysfunction(inflammation and hypermetabolic activity)of epicardial adipose tissue(EAT).EAT is well established as a very active endocrine organ that can regulate the pathophysiological processes of HFpEF with T2DM through the paracrine and endocrine mechanisms.Therefore,suppressing abnormal EAT expansion may be a promising therapeutic strategy for HFpEF with T2DM.Although there is no treatment specifically for EAT,lifestyle management,bariatric surgery,and some pharmaceutical interventions(anti-cytokine drugs,statins,proprotein convertase subtilisin/kexin type 9 inhibitors,metformin,glucagon-like peptide-1 receptor agonists,and especially sodium-glucose cotransporter-2 inhibitors)have been shown to attenuate the inflammatory response or expansion of EAT.Importantly,these treatments may be beneficial in improving the clinical symptoms or prognosis of patients with HFpEF.Accordingly,well-designed randomized controlled trials are needed to validate the efficacy of current therapies.In addition,more novel and effective therapies targeting EAT are needed in the future.

Regeneration of the heart:f rom molecular mechanisms to clinical therapeutics

Heart injury such as myocardial infarction leads to cardiomyocyte loss,fibrotic tissue deposition,and scar formation.These changes reduce cardiac contractility,resulting in heart failure,which causes a huge public health burden.Military personnel,compared with civilians,is exposed to more stress,a risk factor for heart diseases,making cardiovascular health management and treatment innovation an important topic for military medicine.So far,medical intervention can slow down cardiovascular disease progression,but not yet induce heart regeneration.In the past decades,studies have focused on mechanisms underlying the regenerative capability of the heart and applicable approaches to reverse heart injury.Insights have emerged from studies in animal models and early clinical trials.Clinical interventions show the potential to reduce scar formation and enhance cardiomyocyte proliferation that counteracts the pathogenesis of heart disease.In this review,we discuss the signaling events controlling the regeneration of heart tissue and summarize current therapeutic approaches to promote heart regeneration after injury.

Serum cystatin C,monocyte/high-density lipoprotein-C ratio,and uric acid for the diagnosis of coronary heart disease and heart failure

BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.However,conventional diagnostic methods such as electrocardiography,echocardiography,and cardiac biomarkers have certain limitations,such as low sensitivity,specificity,availability,and cost-effectiveness.Therefore,there is a need for simple,noninvasive,and reliable biomarkers to diagnose CHD and HF.AIM To investigate serum cystatin C(Cys-C),monocyte/high-density lipoprotein cholesterol ratio(MHR),and uric acid(UA)diagnostic values for CHD and HF.METHODS We enrolled 80 patients with suspected CHD or HF who were admitted to our hospital between July 2022 and July 2023.The patients were divided into CHD(n=20),HF(n=20),CHD+HF(n=20),and control groups(n=20).The serum levels of Cys-C,MHR,and UA were measured using immunonephelometry and an enzymatic method,respectively,and the diagnostic values for CHD and HF were evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Serum levels of Cys-C,MHR,and UA were significantly higher in the CHD,HF,and CHD+HF groups than those in the control group.The serum levels of Cys-C,MHR,and UA were significantly higher in the CHD+HF group than those in the CHD or HF group.The ROC curve analysis showed that serum Cys-C,MHR,and UA had good diagnostic performance for CHD and HF,with areas under the curve ranging from 0.78 to 0.93.The optimal cutoff values of serum Cys-C,MHR,and UA for diagnosing CHD,HF,and CHD+HF were 1.2 mg/L,0.9×10^(9),and 389μmol/L;1.4 mg/L,1.0×10^(9),and 449μmol/L;and 1.6 mg/L,1.1×10^(9),and 508μmol/L,respectively.CONCLUSION Serum Cys-C,MHR,and UA are useful biomarkers for diagnosing CHD and HF,and CHD+HF.These can provide information for decision-making and risk stratification in patients with CHD and HF.

The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation

The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization scheme.In this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy simulation.The results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved variables.The probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous studies.Further analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the future.The results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization.

Prediction model for corrosion rate of low-alloy steels under atmospheric conditions using machine learning algorithms

This work constructed a machine learning(ML)model to predict the atmospheric corrosion rate of low-alloy steels(LAS).The material properties of LAS,environmental factors,and exposure time were used as the input,while the corrosion rate as the output.6 dif-ferent ML algorithms were used to construct the proposed model.Through optimization and filtering,the eXtreme gradient boosting(XG-Boost)model exhibited good corrosion rate prediction accuracy.The features of material properties were then transformed into atomic and physical features using the proposed property transformation approach,and the dominant descriptors that affected the corrosion rate were filtered using the recursive feature elimination(RFE)as well as XGBoost methods.The established ML models exhibited better predic-tion performance and generalization ability via property transformation descriptors.In addition,the SHapley additive exPlanations(SHAP)method was applied to analyze the relationship between the descriptors and corrosion rate.The results showed that the property transformation model could effectively help with analyzing the corrosion behavior,thereby significantly improving the generalization ability of corrosion rate prediction models.

Experimental study on the effect of unloading rate on gneiss rockburst

Rockburst are often encountered in tunnel construction due to the complex geological conditions.To study the influence of unloading rate on rockburst,gneiss rockburst experiments were conducted under three groups of unloading rates.A high-speed photography system and acoustic emission(AE)system were used to monitor the entire process of rockburst process in real-time.The results show that the intensity of gneiss rockburst decreases with decrease of unloading rate,which is manifested as the reduction of AE energy and fragments ejection velocity.The mechanisms are proposed to explain this effect:(i)The reduction of unloading rate changes the crack propagation mechanism in the process of rockburst.This makes the rockbursts change from the tensile failure mechanism at high unloading rate to the tension-shear mixed failure mechanism at low unloading rate,and more energy released in the form of shear crack propagation.Then,less strain energy is converted into kinetic energy of fragments ejection.(ii)Less plate cracking degree of gneiss has taken shape due to decrease of unloading rate,resulting in the destruction of rockburst incubation process.The enlightenments of reducing the unloading rate for the project are also described quantitatively.The rockburst magnitude is reduced from the medium magnitude at the unloading rate of 0.1 MPa/s to the slight magnitude at the unloading rate of 0.025 MPa/s,which was judged by the ejection velocity.

A new era of mutation rate analyses: Concepts and methods

The mutation rate is a pivotal biological characteristic,intricately governed by natural selection and historically garnering considerable attention.Recent advances in high-throughput sequencing and analytical methodologies have profoundly transformed our understanding in this domain,ushering in an unprecedented era of mutation rate research.This paper aims to provide a comprehensive overview of the key concepts and methodologies frequently employed in the study of mutation rates.It examines various types of mutations,explores the evolutionary dynamics and associated theories,and synthesizes both classical and contemporary hypotheses.Furthermore,this review comprehensively explores recent advances in understanding germline and somatic mutations in animals and offers an overview of experimental methodologies,mutational patterns,molecular mechanisms,and driving forces influencing variations in mutation rates across species and tissues.Finally,it proposes several potential research directions and pressing questions for future investigations.