Background: Venous thromboembolism (VTE) is among the leading causes of hospital-related disability-adjusted life years lost. We aimed to determine the prevalence and determinants of functional capacity impairment six...Background: Venous thromboembolism (VTE) is among the leading causes of hospital-related disability-adjusted life years lost. We aimed to determine the prevalence and determinants of functional capacity impairment six to twelve months after an acute VTE event. Methods: This was a cross-sectional study conducted between January and April 2021 in two referral hospitals of Yaoundé, including consenting adult patients admitted to these hospitals six to twelve months ago for VTE. We excluded dead patients and those with any comorbidity or symptoms limiting physical activity. The functional outcome was assessed with the six-minute walk test. Functional capacity impairment was defined as walking distance lower than the expected value. Results: We included 27 cases in this study with a mean age of 53.2 ± 14.4 years. The prevalence of functional capacity impairment was 29.6% (95% CI: 14.8 - 48.1). Factors associated with poor functional outcome were obesity (OR: 59.5;95% CI: 4.6 - 767.2;p - 207.4;p = 0.017), massive PE (OR: 30;95% CI: 2.5 - 354;p = 0.004), and poor adherence to treatment (OR: 30.3;95% CI: 2.5 - 333.3;p = 0.004). Conclusion: Functional capacity impairment is common in the medium-term after VTE and factors associated with this poor outcome are obesity, the severity of the VTE, and poor adherence to treatment.展开更多
Objective: This study aimed to evaluate the efficacy of trimetazidine on exercise capacity via a six-minute walk test in patients with ischaemic cardiomyopathy and also evaluate the effect of trimetazidine on left ven...Objective: This study aimed to evaluate the efficacy of trimetazidine on exercise capacity via a six-minute walk test in patients with ischaemic cardiomyopathy and also evaluate the effect of trimetazidine on left ventricular function via echocardiography in the same population. Methods: This prospective observational study, conducted at the National Institute of Cardiovascular Diseases in Dhaka, Bangladesh, enrolled 200 patients with ischaemic cardiomyopathy and a depressed left ventricular ejection fraction (LVEF Results: In this study (n = 200) of ischaemic cardiomyopathy patients, the mean age was 58 years, with 76% of the patients being male. All study subjects received GDMT (Guideline-Directed Medical Therapy) for angina and heart failure. Those who received the modified released form of trimetazidine developed lesions during the 1st and 2nd follow-ups, during which the LVEF, LVIDd, and six-minute walk distance significantly improved (p Conclusion: The findings of the present study demonstrated that the addition of modified-release trimetazidine to GDMT can improve exercise capacity and left ventricular function in patients with ischaemic cardiomyopathy.展开更多
Coronary heart disease is among the most prevalent and costly of all global health problems. Coronary artery bypass grafting (CABG) has been increasingly used since the 1960s. Coronary heart disease is a leading cause...Coronary heart disease is among the most prevalent and costly of all global health problems. Coronary artery bypass grafting (CABG) has been increasingly used since the 1960s. Coronary heart disease is a leading cause of death worldwide, including Sudan. Self-efficacy and functional capacity is a critical factor for quality of life in patients who has undergone CABG as well as for their caregivers from their families. Aim of the Study: To explore the effects of an educational program on self-efficacy and functional capacity of patients after CABG. 1) There will be no significant difference between the intervention group and control group concerning knowledge regarding Self-efficacy and functional capacity post CABG surgery. 2) The application of our educational program for the patients will enhance the patients with CABG surgery and improve knowledge about Self-efficacy and functional capacity post CABG surgery. 3) There are some socio demographic factors that affect the response to the educational program. Methods: This was a quasi-experimental, interventional and hospital-based study, including pre-test, a post-test and follow-up test, with a control group, conducted during the period from September 2014 to June 2019. Patients were recruited consecutively to the cases and control group using convenience sampling. The sample consisted of 76 patients;41 as cases and 35 as control group. The sample included those who had undergone CABG in Khartoum State. Relevant data were collected using a checklist to monitor the effect of a health education program on self-efficacy and functional capacity of the patients. Result: The results showed marked improvement in patients’ self-efficacy and functional capacity between pretest and posttest for the study group;p-value = (0.001) in the health status of cases in comparison to the control group. The indices were observed to be higher for patients who received a nursing educational program throughout the study period;p-value = (0.002).展开更多
Background: Chronic heart failure is a public health problem worldwide. It has a high mortality rate and is accompanied by a decreased functional capacity and alteration of the quality of life. Objective: This st...Background: Chronic heart failure is a public health problem worldwide. It has a high mortality rate and is accompanied by a decreased functional capacity and alteration of the quality of life. Objective: This study aimed to assess the cardiovascular functional capacity of a group of patients suffering from heart failure using the 6-minute walk test (6 MWT). Methods: This was a cross-sectional study carried out in the cardiology unit of Douala’s general hospital for 4 months. We included all eligible patients aged 18 years or more who had stable chronic heart failure and gave informed consent. Those who had an acute coronary syndrome (≤1 month), tachycardia (HR ≥ 120 bpm), high blood pressure (SBP ≥ 180 mmHg and/or DBP ≥ 100 mmHg) and reduced mobility due to orthopaedic reasons were excluded. A 6 MWT was done according to the American Thoracic Society guidelines. The 6 MWT result was considered poor for - 450 m and good for >450 m. Results: We recruited a total of 81 patients (61.7% women) with a mean age of 65.9 ± 10.6 years. The most frequent risk factor for heart failure was high blood pressure (77.8%), alcohol consumption(69.1%) and a sedentary lifestyle (53.1%). The left ventricular ejection fraction was mostly preserved (42.0%) or mildly altered (46.9). The 6 MWT results were poor in 55.6% of cases, average in 19.8% of cases and good in only 24.7% of cases. More than half (59.3%) of the participants perceived the effort as being difficult. The cardiovascular functional capacity was significantly associated with age, heart failure stage and physical activity (p Conclusion: Most patients suffering from chronic stable heart failure in the general hospital of Douala have poor cardiovascular functional capacity.展开更多
Cardiac rehabilitation is recommended for patients with chronic heart failure (CHF) with preserved, or reduced left ventricular ejection fraction (LVEF). A cardiac rehabilitation program generally includes physical ex...Cardiac rehabilitation is recommended for patients with chronic heart failure (CHF) with preserved, or reduced left ventricular ejection fraction (LVEF). A cardiac rehabilitation program generally includes physical exercise, diet counseling, educational classes on lifestyle changes, and disease management as well as psychosocial support for patients and their families. Exercise training is a core component of the comprehensive cardiac rehabilitation program and is strongly recommended in combination with pharmacological treatment to patients with CHF, due to cardiorespiratory, metabolic, and autonomic cardiac response. Exercise-based cardiac rehabilitation affects positively functional capacity, exercise tolerance, and quality of life in CHF patients. The physical inactivity rate in Arabian Peninsula countries is extremely high, and exercise training of habitually physically inactive individuals should result in marked improvements of physical capacity. We present a case that demonstrates such a significant improvement in the physical capacity of a patient with CHF and a review of literature.展开更多
<strong>Introduction:</strong> It is a fact that the elderly population has been increasing all around the world and also in Brazil. This has been a challenge for governments and managers in the developmen...<strong>Introduction:</strong> It is a fact that the elderly population has been increasing all around the world and also in Brazil. This has been a challenge for governments and managers in the development of public policies to promote healthy and quality aging. And one of the conditions for healthy aging is to assess the functional capacity and quality of life of elderly people. <strong>Objective:</strong> The aim of the present study was to evaluate the factors that influence the loss of functional capacity and the worsening of the quality of life of a representative sample of elderly people from a medium-sized city in the inner of S<span style="white-space:nowrap;">ã</span>o Paulo State, Brazil. <strong>Methodology:</strong> Questionnaires about activities of daily living (ADL), instrumental activities of daily living (IADL), Flanagan quality of life scale (FQOLS), sociodemographic and morbidities aspects were applied to the elderly people. In order to assess associated factors to functional capacity and quality of life, chi-square tests and logistic regression models were fitted including variables: gender, age group, marital status, income, education level, body mass index, abdominal circumference and some morbidities reported by the elderly people. The level of significance adopted for the statistical tests was 5%. <strong>Results:</strong> Elderly with age over 75 years old and not married had more risk to be dependent on ADL, while elderly with more than 75 years old, not married, income below one minimal wage, cardiovascular disease and be diabetic had more risk to be dependent by IADL. Already, people with excess of weight had smallest risk to be dependent by IADL, paradoxically. The elderly not married and with an income below a minimum wage had the worst quality of life. <strong>Conclusions: </strong>Population aging in Brazil is an evident factor, so it is hoped that this study will contribute to the greatest diligence on the issues of the elderly and related social problems.展开更多
Background: The functional capacity of elderly patients decreases with age due to a combination of age-related decline in physiologic functions and chronic diseases. A severe decrease leads to an inability to carry ou...Background: The functional capacity of elderly patients decreases with age due to a combination of age-related decline in physiologic functions and chronic diseases. A severe decrease leads to an inability to carry out activities of daily living leading to a loss of autonomy and increased dependence. The aim of this study was to evaluate the functional capacity of the elderly followed at the Yaoundé Central Hospital. Methods: We carried out a non-probabilistic consecutive sampling of elderly patients that consulted in Yaoundé Central Hospital during a five-month’ period. Data was taken concerning their chronic conditions, use of medication, and presence of depressive symptoms (evaluated using the Geriatric Depression Scale (GDS) questionnaire). The presence of any cognitive impairment was evaluated using the Mini-Mental State Examination (MMSE). Cardiac ultrasonography and electrocardiograms were done to evaluate the cardiac morphology and physiology. Their functional capacity was assessed with the WHO Global Physical Activity Questionnaire and the six-minute walk test. A self-paced step test was equally done to estimate the maximum oxygen consumption during aerobic exercise. We carried out aunivariate, and then multivariate analyses to identify factors associated with an altered functional status. Statistical analysis was performed using the SPSS software 23.0. The threshold of significance was set at 0.05. Results: 66 participants were included (35 women) with a median age of 70 (IQR: 67 - 75) years. Among them, 39.4% were found to have an altered functional capacity, about 87.8% had at least one chronic condition and 47% had two or more. The most prevalent chronic condition was hypertension (71.2%) followed by heart failure (24.2%) and osteoarthritis (12.1%). Mild depressive symptoms were present in 1.5% of our study population. The factors associated with an altered functional capacity include age ≥ 75 years (OR = 2.9 p heart failure (OR: 3.2, p ), osteoarthritis (OR: 5.1, p ), and poor gait and balance (OR: 3.7, p ). Conclusion: There is a high prevalence of altered functional capacity among elderly patients consulting at the Yaoundé Central Hospital. Heart failure, osteoarthritis, and an increased risk of falls are associated with an altered functional capacity.展开更多
<strong>Background: </strong>Cardiac rehabilitation (CR) is a multifaceted treatment that can increase the survival and quality of life of cardiac patients by increasing their functional capacity (FC). In ...<strong>Background: </strong>Cardiac rehabilitation (CR) is a multifaceted treatment that can increase the survival and quality of life of cardiac patients by increasing their functional capacity (FC). In this study, we aimed to investigate the FC changes of cardiac patients after the CR program in different subgroups in terms of anthropometric, clinical, and psychological indices. <strong>Materials and Methods:</strong> This is a descriptive retrospective study that has been derived from the results of a Cohort study at the Rehabilitation Research Center of the Cardiovascular Research Institute of Isfahan (Iran), from 2006 to 2017. In this study, the dependent variable is functional capacity changes based on Mets obtained in exercise testing at the beginning and end of the CR program. Independent variables included age, sex, dyslipidemia, diabetes, smoking, and Body mass index, type of intervention, depression, and EF. <strong>Results:</strong> The sample size is 1250 cardiovascular patients, of which 917 (73.5%) are male and 331 (26.5%) are female. Functional capacity after the CR program significantly increased in all age, gender, body mass index, hypertension, hyperlipidemia, diabetes, smoking, depression, EF, and type of operation performed (angioplasty or open-heart surgery) subgroups, (p < 0.001). Using multiple linear regression analysis, a significant relationship was found between Mets changes and only the variables of gender, depression, and EF. <strong>Conclusion:</strong> The results of this study show the importance of rehabilitation programs in the secondary prevention of cardiovascular disease in different subgroups and factors such as gender, level of primary depression, and EF less than 35 are the most important factors affecting functional capacity increase after CR program in heart patients.展开更多
Objectives: Psychosocial factors are important determinants of cardiovascular health outcomes in rehabilitation. However, the relationship between exercise performance and individual factors remained poorly understood...Objectives: Psychosocial factors are important determinants of cardiovascular health outcomes in rehabilitation. However, the relationship between exercise performance and individual factors remained poorly understood. This study investigated the relationship between functional capacity and psychosocial correlates of exercise in Nigerian patients with hypertension. Study Design and Setting: This quasi-experimental study recruited 120 patients with hypertension (≥140/90 ≤ 179/109 mmHg) from the Cardiac Care Unit of a Nigerian university teaching using purposive sampling technique. Functional capacity was assessed using the 6-minute walk test and maximum oxygen consumption (VO<sub>2</sub> max) was estimated. Participants also underwent a 30-minute self-paced walking exercise. Thereafter, psychosocial correlates of exercise including exercise self-efficacy (ESE), social support (SoS), perceived exercise barrier (PEB) and socio-economic status (SES) were assessed using validated questionnaires. Descriptive and inferential statistics were used to analyze data. Alpha level was set at p < 0.05 of significance. Results: A majority of the participants demonstrated high ESE (75.0%), moderate SoS (60.9%) and low PEB (71.7%). More than half (58.4%) of the participants were in the middle SES. Male and female participants were comparable in ESE scores (p = 0.554), SoS (p = 0.362) and six-minute walk distance (6-MWD) (p = 0.194) except in body mass index (p < 0.05). The mean 6-MWD and VO<sub>2</sub> max were 350.6 ± 54.7 m and 9.74 ± 1.5 ml/kg/min respectively. There were significant correlations between functional capacity and each of ESE (r = 0.184;p = 0.026) and SoS (r = 0.374;p = 0.021). Conclusions: Psychosocial correlates of exercise including self-efficacy and social support were significantly associated with functional capacity among Nigerian patients with mild to moderate hypertension.展开更多
Background: Flight is the central avian adaptation in evolution. Wing muscles form an important anatomical basis for avian flight, affecting wing performance and determine modes of flight. However, the roles of distal...Background: Flight is the central avian adaptation in evolution. Wing muscles form an important anatomical basis for avian flight, affecting wing performance and determine modes of flight. However, the roles of distal muscles in adjusting the wing, as well as their functional specializations, remain largely unknown. The importance of muscle fiber architecture has long been recognized. In this study, we provide quantitative anatomical data on the muscle architecture of the forelimb of the Golden Pheasant(Chrysolophus pictus), with an emphasis on brachial,antebrachial and manual segments.Methods: The forelimbs of five Golden Pheasants were dissected and detailed measurements of all muscles were made, including muscle mass, muscle belly length, fascicle length. From these values, muscle volume, physiological cross-sectional area(PCSA) and maximum isometric force were derived.Results: General trends such as the distribution of muscle mass, fascicle length and the ratio of tendon length/belly length are revealed. Comparing PCSAs between antebrachial depressors and elevators and between intrinsics of the alular digit and major digit yielded significant differences(p < 0.05). Pronounced development of the antebrachial depressors suggests that ventral rotation of the distal half of the wing is a pivotal factor in shape change and orientation modulation. Large PCSAs in tandem with the force generation capability of the major digit intrinsics may help stabilize the digits while enhancing support of the primary feathers. The architectural properties of the alular digit confirm that alular adjustment is essential to rapid adduction and abduction.Conclusions: These observations illustrate the underlying structural basis for the functional capacities of the distal forelimb muscles and may provide additional information useful in further biomechanical and in vivo investigations.展开更多
AIM: To examine the utility of Six Minute Walk Test (6MWT) in patients with chronic liver disease (CLD). METHODS: Two hundred and fifty subjects between the ages of 18 and 80 (mean 47) years performed 6MWT and the Six...AIM: To examine the utility of Six Minute Walk Test (6MWT) in patients with chronic liver disease (CLD). METHODS: Two hundred and fifty subjects between the ages of 18 and 80 (mean 47) years performed 6MWT and the Six Minute Walk Distance (6MWD) was measured. RESULTS: The subjects were categorized into four groups. Group A (n = 45) healthy subjects (control); group B (n = 49) chronic hepatitis B patients; group C (n = 54) chronic hepatitis C patients; group D (n = 98) liver cirrhosis patients. The four groups differed in terms of 6MWDs (P < 0.001). The longest distance walked was 421 ± 47 m by group A, then group B (390 ± 53 m), group C (357 ± 72 m) and group D (306 ± 111 m). The 6MWD correlated with age (r = -0.482, P < 0.01), hemoglobin (r = +0.373, P < 0.001) and albumin (r = +0.311, P < 0.001) levels. The Child-Pugh classification was negatively correlated with the 6MWD in cirrhosis (group D) patients (r = -0.328, P < 0.01). At the end of a 12 mo follow-up period, 15 of the 98 cirrhosis patients had died from disease complications. The 6MWD for the surviving cirrhotic patients was longer than for non-survivors (317 ± 101 vs 245 ± 145 m, P = 0.021; 95% CI 11-132). The 6MWD was found to be an independent predictor of survival (P = 0.024). CONCLUSION: 6MWT is a useful tool for assessing physical function in CLD patients. We suggest that 6MWD may serve as a prognostic indicator in patients with liver cirrhosis.展开更多
Functional capacity is the condition of an individual living independently and the lack of it for preparing and eating food, which is a factor that can result in malnutrition and deserves the attention of professional...Functional capacity is the condition of an individual living independently and the lack of it for preparing and eating food, which is a factor that can result in malnutrition and deserves the attention of professionals and his family members. Then, the aim of this work was to evaluate the relationship between nutritional status and functional capacity for older adults using anthropometric measures and questionnaires for activities of daily and instrumental living. It was an epidemiological cross-sectional study using a representative sample of older adults selected from a previous study about quality of life in a Botucatu city, Sao Paulo. Brazil. The sample size was calculated considering 95% of reliability and 5% of error margin, resulting from a total of 365 individuals of both sexes but only 361 of them completed the protocol. Data included sociodemographic and morbidities questionnaires, activities of daily and instrumental living (ADL and IADL) and an-thropometric variables. 62.6% of the older were women, 44.68% were hypertensive, 28.81% were diabetic and 15.51% had hypercholesterolemia. 94.24% and 92.42% of the older were fully independent for ADL and IADL, respectively. Associations between ADL with marital status and schooling were found as well as with IADL. Also, it was found association with IADL and heart disease. Regarding anthropometry most of measures when compared men and women were significant. No significant association was found between nutritional status and ADL. A logistic regression model was fitted considering ADL as a response variable showed BMI as a protection factor and WC as a risk factor for dependence. For IADL, heart disease was a risk factor for dependence. In conclusion, low weight and increased waist circumference have influence in a functional capacity of older adults according to the activities daily living (ADL) and heart disease for IADL.展开更多
Anemia in the elderly population has been associated to clinical manifestations such as functional dependence, low cognitive performance, increased mortality and geriatric syndromes (dementia, delirium, depression and...Anemia in the elderly population has been associated to clinical manifestations such as functional dependence, low cognitive performance, increased mortality and geriatric syndromes (dementia, delirium, depression and falls). Recent investigations have shown an association between low hemoglobin levels, reduction in muscular strength and physical fitness. The objective of this review was to identify, in the scientific literature, evidence of an association between anemia and functional capacity among older persons. PubMed and Bireme were used as references source. The most relevant evidence pointing towards this association was identified in the epidemiological studies Women’s Health and Aging Studies I and II (WHAS I and II). Functional capacity was evaluated by the walking, balance and sitting back and getting out of the chair tests. Elderly women with either 13 or 14 g/dl have a better performance compared to women with 12 g/dl of hemoglobin, respectively. This study also reported an increase in the mortality risk among women (65 years old and plus) living in community with less than 13.4 g/dl of hemoglobin. Participants were followed for 11 years. WHAS I and II investigators suggested a new criterion, already adopted by the World Health Organization (WHO), to define anemia among elderly women. Conclusion: anemia is common among the elderly and may have an involvement in the impairment of their functional capacity. However, in spite of the importance of these findings, it should be emphasized that an etiologic association (anemia as a cause of functional impairment) has yet to be demonstrated.展开更多
Objective:Arterial stiffness is an important predictor of cardiovascular disease.Microbial diversity in the gut has been shown to be associated inversely with arterial stiffness in Caucasian populations.However,due to...Objective:Arterial stiffness is an important predictor of cardiovascular disease.Microbial diversity in the gut has been shown to be associated inversely with arterial stiffness in Caucasian populations.However,due to the different profiles of the gut microbiota among ethnicities,the relationship between gut-microbiota dysbiosis and the progression of arterial stiffness merits further investigation.This study aimed to investigate the association between the composition and functional capacity of the gut microbiota and the progression of arterial stiffness.Methods:“Shotgun”metagenomics sequencing were undertaken in 96 individuals from a hypertension-associated gut-microbiota study in the Kailuan cohort,who measured brachial-ankle pulse wave velocity(baPWV)and provided fecal samples between September 2014 and February 2015 at Kailuan General Hospital and 11 affiliated hospitals.The different composition and functional capacity of the gut microbiota were compared between individuals without arterial stiffness(normal arterial stiffness group,baPWV<1,400 cm/s,n=27)and participants with arterial stiffness(increased arterial stiffness group,baPWV≥1,400 cm/s,n=69)at baseline.These participants were followed up prospectively for a mean duration of 2.6 years,and 50 underwent a repeat baPWV measurement.Associations between the gut microbiota and severity and progression of arterial stiffness were assessed using MaAsLin2 software after adjustment for age,sex,and mean arterial blood pressure and correction for multiple testing.Gene“catalogs”were aligned to the Kyoto Encyclopedia of Genes and Genomes(KEGG)database to obtain information for potential functional capacities of the gut microbiota.Results:In this study,14 genera and 50 species of bacteria were identified to be abundant in participants with normal arterial stiffness compared with those with increased arterial stiffness.Of 14 genera,the prevalence of beneficial bacteria of the genera Leadbetterella and Cytophaga was correlated inversely with baPWV(P<0.05).Analyses of functional capacity revealed gut-microbial dysfunctions in the synthetic processes of“threonine dehydratase”“hypothetical protein”“mannosyl transferase”and“type-IV secretion-system proteins”in individuals suffering from arterial stiffness.During follow-up,bacteria of the proinflammatory genera Escherichia,Shigella,and Ruegeria were enriched in individuals with increased baPWV.Functional analyses showed that 26 KEGG orthologs of gut microbes were associated with an increase in baPWV and involved in“carbohydrate metabolism”“amino acid metabolism”and“protein families related to genetic information processing.”Conclusions:The composition and functional capacity of the microbial community in the gut of people suffering from arterial stiffness differed from those in individuals not suffering from arterial stiffness.Our data provide a new direction for the causality of the host-gut microbiota in arterial stiffness.展开更多
Our brain is constantly active.Even at rest,the brain carries out essential functions such as maintenance of resting potentials,subthreshold synaptic activity,and spiking activity related to information processing.Thi...Our brain is constantly active.Even at rest,the brain carries out essential functions such as maintenance of resting potentials,subthreshold synaptic activity,and spiking activity related to information processing.This resting activity can be assessed with several in vivo tools,such as resting-state functional magnetic resonance imaging.This technique measures subtle changes in blood flow,volume,and oxygenation that occur over time.Although vascular in nature,resting-state functional magnetic resonance imaging is considered a reliable proxy of neural activity and several studies have shown that the brain is functionally divided into interacting neural networks called the“functional connectome”.展开更多
Functional magnetic resonance imaging(fMRI)is a popular tool used to investigate not only how the brain responds to specific stimuli during sensorimotor or cognitive tasks,but also brain activity at rest.The physics b...Functional magnetic resonance imaging(fMRI)is a popular tool used to investigate not only how the brain responds to specific stimuli during sensorimotor or cognitive tasks,but also brain activity at rest.The physics beyond this approach is based on the analysis of the blood oxygenation level-dependent signal.展开更多
With its generality and practicality, the combination of partial charging curves and machine learning(ML) for battery capacity estimation has attracted widespread attention. However, a clear classification,fair compar...With its generality and practicality, the combination of partial charging curves and machine learning(ML) for battery capacity estimation has attracted widespread attention. However, a clear classification,fair comparison, and performance rationalization of these methods are lacking, due to the scattered existing studies. To address these issues, we develop 20 capacity estimation methods from three perspectives:charging sequence construction, input forms, and ML models. 22,582 charging curves are generated from 44 cells with different battery chemistry and operating conditions to validate the performance. Through comprehensive and unbiased comparison, the long short-term memory(LSTM) based neural network exhibits the best accuracy and robustness. Across all 6503 tested samples, the mean absolute percentage error(MAPE) for capacity estimation using LSTM is 0.61%, with a maximum error of only 3.94%. Even with the addition of 3 m V voltage noise or the extension of sampling intervals to 60 s, the average MAPE remains below 2%. Furthermore, the charging sequences are provided with physical explanations related to battery degradation to enhance confidence in their application. Recommendations for using other competitive methods are also presented. This work provides valuable insights and guidance for estimating battery capacity based on partial charging curves.展开更多
Base isolators used in buildings provide both a good acceleration reduction and structural vibration control structures.The base isolators may lose their damping capacity over time due to environmental or dynamic effe...Base isolators used in buildings provide both a good acceleration reduction and structural vibration control structures.The base isolators may lose their damping capacity over time due to environmental or dynamic effects.This deterioration of them requires the determination of the maintenance and repair needs and is important for the long-termisolator life.In this study,an artificial intelligence prediction model has been developed to determine the damage and maintenance-repair requirements of isolators as a result of environmental effects and dynamic factors over time.With the developed model,the required damping capacity of the isolator structure was estimated and compared with the previously placed isolator capacity,and the decrease in the damping property was tried to be determined.For this purpose,a data set was created by collecting the behavior of structures with single degrees of freedom(SDOF),different stiffness,damping ratio and natural period isolated from the foundation under far fault earthquakes.The data is divided into 5 different damping classes varying between 10%and 50%.Machine learning model was trained in damping classes with the data on the structure’s response to random seismic vibrations.As a result of the isolator behavior under randomly selected earthquakes,the recorded motion and structural acceleration of the structure against any seismic vibration were examined,and the decrease in the damping capacity was estimated on a class basis.The performance loss of the isolators,which are separated according to their damping properties,has been tried to be determined,and the reductions in the amounts to be taken into account have been determined by class.In the developed prediction model,using various supervised machine learning classification algorithms,the classification algorithm providing the highest precision for the model has been decided.When the results are examined,it has been determined that the damping of the isolator structure with the machine learning method is predicted successfully at a level exceeding 96%,and it is an effective method in deciding whether there is a decrease in the damping capacity.展开更多
In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at ...In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at extremely high temperatures.However,stochastic density functional theory(SDFT)can overcome this limitation.Recently,SDFT and the related mixed stochastic–deterministic density functional theory,based on a plane-wave basis set,have been implemented in the first-principles electronic structure software ABACUS[Q.Liu and M.Chen,Phys.Rev.B 106,125132(2022)].In this study,we combine SDFT with the Born–Oppenheimer molecular dynamics method to investigate systems with temperatures ranging from a few tens of eV to 1000 eV.Importantly,we train machine-learning-based interatomic models using the SDFT data and employ these deep potential models to simulate large-scale systems with long trajectories.Subsequently,we compute and analyze the structural properties,dynamic properties,and transport coefficients of warm dense matter.展开更多
文摘Background: Venous thromboembolism (VTE) is among the leading causes of hospital-related disability-adjusted life years lost. We aimed to determine the prevalence and determinants of functional capacity impairment six to twelve months after an acute VTE event. Methods: This was a cross-sectional study conducted between January and April 2021 in two referral hospitals of Yaoundé, including consenting adult patients admitted to these hospitals six to twelve months ago for VTE. We excluded dead patients and those with any comorbidity or symptoms limiting physical activity. The functional outcome was assessed with the six-minute walk test. Functional capacity impairment was defined as walking distance lower than the expected value. Results: We included 27 cases in this study with a mean age of 53.2 ± 14.4 years. The prevalence of functional capacity impairment was 29.6% (95% CI: 14.8 - 48.1). Factors associated with poor functional outcome were obesity (OR: 59.5;95% CI: 4.6 - 767.2;p - 207.4;p = 0.017), massive PE (OR: 30;95% CI: 2.5 - 354;p = 0.004), and poor adherence to treatment (OR: 30.3;95% CI: 2.5 - 333.3;p = 0.004). Conclusion: Functional capacity impairment is common in the medium-term after VTE and factors associated with this poor outcome are obesity, the severity of the VTE, and poor adherence to treatment.
文摘Objective: This study aimed to evaluate the efficacy of trimetazidine on exercise capacity via a six-minute walk test in patients with ischaemic cardiomyopathy and also evaluate the effect of trimetazidine on left ventricular function via echocardiography in the same population. Methods: This prospective observational study, conducted at the National Institute of Cardiovascular Diseases in Dhaka, Bangladesh, enrolled 200 patients with ischaemic cardiomyopathy and a depressed left ventricular ejection fraction (LVEF Results: In this study (n = 200) of ischaemic cardiomyopathy patients, the mean age was 58 years, with 76% of the patients being male. All study subjects received GDMT (Guideline-Directed Medical Therapy) for angina and heart failure. Those who received the modified released form of trimetazidine developed lesions during the 1st and 2nd follow-ups, during which the LVEF, LVIDd, and six-minute walk distance significantly improved (p Conclusion: The findings of the present study demonstrated that the addition of modified-release trimetazidine to GDMT can improve exercise capacity and left ventricular function in patients with ischaemic cardiomyopathy.
文摘Coronary heart disease is among the most prevalent and costly of all global health problems. Coronary artery bypass grafting (CABG) has been increasingly used since the 1960s. Coronary heart disease is a leading cause of death worldwide, including Sudan. Self-efficacy and functional capacity is a critical factor for quality of life in patients who has undergone CABG as well as for their caregivers from their families. Aim of the Study: To explore the effects of an educational program on self-efficacy and functional capacity of patients after CABG. 1) There will be no significant difference between the intervention group and control group concerning knowledge regarding Self-efficacy and functional capacity post CABG surgery. 2) The application of our educational program for the patients will enhance the patients with CABG surgery and improve knowledge about Self-efficacy and functional capacity post CABG surgery. 3) There are some socio demographic factors that affect the response to the educational program. Methods: This was a quasi-experimental, interventional and hospital-based study, including pre-test, a post-test and follow-up test, with a control group, conducted during the period from September 2014 to June 2019. Patients were recruited consecutively to the cases and control group using convenience sampling. The sample consisted of 76 patients;41 as cases and 35 as control group. The sample included those who had undergone CABG in Khartoum State. Relevant data were collected using a checklist to monitor the effect of a health education program on self-efficacy and functional capacity of the patients. Result: The results showed marked improvement in patients’ self-efficacy and functional capacity between pretest and posttest for the study group;p-value = (0.001) in the health status of cases in comparison to the control group. The indices were observed to be higher for patients who received a nursing educational program throughout the study period;p-value = (0.002).
文摘Background: Chronic heart failure is a public health problem worldwide. It has a high mortality rate and is accompanied by a decreased functional capacity and alteration of the quality of life. Objective: This study aimed to assess the cardiovascular functional capacity of a group of patients suffering from heart failure using the 6-minute walk test (6 MWT). Methods: This was a cross-sectional study carried out in the cardiology unit of Douala’s general hospital for 4 months. We included all eligible patients aged 18 years or more who had stable chronic heart failure and gave informed consent. Those who had an acute coronary syndrome (≤1 month), tachycardia (HR ≥ 120 bpm), high blood pressure (SBP ≥ 180 mmHg and/or DBP ≥ 100 mmHg) and reduced mobility due to orthopaedic reasons were excluded. A 6 MWT was done according to the American Thoracic Society guidelines. The 6 MWT result was considered poor for - 450 m and good for >450 m. Results: We recruited a total of 81 patients (61.7% women) with a mean age of 65.9 ± 10.6 years. The most frequent risk factor for heart failure was high blood pressure (77.8%), alcohol consumption(69.1%) and a sedentary lifestyle (53.1%). The left ventricular ejection fraction was mostly preserved (42.0%) or mildly altered (46.9). The 6 MWT results were poor in 55.6% of cases, average in 19.8% of cases and good in only 24.7% of cases. More than half (59.3%) of the participants perceived the effort as being difficult. The cardiovascular functional capacity was significantly associated with age, heart failure stage and physical activity (p Conclusion: Most patients suffering from chronic stable heart failure in the general hospital of Douala have poor cardiovascular functional capacity.
文摘Cardiac rehabilitation is recommended for patients with chronic heart failure (CHF) with preserved, or reduced left ventricular ejection fraction (LVEF). A cardiac rehabilitation program generally includes physical exercise, diet counseling, educational classes on lifestyle changes, and disease management as well as psychosocial support for patients and their families. Exercise training is a core component of the comprehensive cardiac rehabilitation program and is strongly recommended in combination with pharmacological treatment to patients with CHF, due to cardiorespiratory, metabolic, and autonomic cardiac response. Exercise-based cardiac rehabilitation affects positively functional capacity, exercise tolerance, and quality of life in CHF patients. The physical inactivity rate in Arabian Peninsula countries is extremely high, and exercise training of habitually physically inactive individuals should result in marked improvements of physical capacity. We present a case that demonstrates such a significant improvement in the physical capacity of a patient with CHF and a review of literature.
文摘<strong>Introduction:</strong> It is a fact that the elderly population has been increasing all around the world and also in Brazil. This has been a challenge for governments and managers in the development of public policies to promote healthy and quality aging. And one of the conditions for healthy aging is to assess the functional capacity and quality of life of elderly people. <strong>Objective:</strong> The aim of the present study was to evaluate the factors that influence the loss of functional capacity and the worsening of the quality of life of a representative sample of elderly people from a medium-sized city in the inner of S<span style="white-space:nowrap;">ã</span>o Paulo State, Brazil. <strong>Methodology:</strong> Questionnaires about activities of daily living (ADL), instrumental activities of daily living (IADL), Flanagan quality of life scale (FQOLS), sociodemographic and morbidities aspects were applied to the elderly people. In order to assess associated factors to functional capacity and quality of life, chi-square tests and logistic regression models were fitted including variables: gender, age group, marital status, income, education level, body mass index, abdominal circumference and some morbidities reported by the elderly people. The level of significance adopted for the statistical tests was 5%. <strong>Results:</strong> Elderly with age over 75 years old and not married had more risk to be dependent on ADL, while elderly with more than 75 years old, not married, income below one minimal wage, cardiovascular disease and be diabetic had more risk to be dependent by IADL. Already, people with excess of weight had smallest risk to be dependent by IADL, paradoxically. The elderly not married and with an income below a minimum wage had the worst quality of life. <strong>Conclusions: </strong>Population aging in Brazil is an evident factor, so it is hoped that this study will contribute to the greatest diligence on the issues of the elderly and related social problems.
文摘Background: The functional capacity of elderly patients decreases with age due to a combination of age-related decline in physiologic functions and chronic diseases. A severe decrease leads to an inability to carry out activities of daily living leading to a loss of autonomy and increased dependence. The aim of this study was to evaluate the functional capacity of the elderly followed at the Yaoundé Central Hospital. Methods: We carried out a non-probabilistic consecutive sampling of elderly patients that consulted in Yaoundé Central Hospital during a five-month’ period. Data was taken concerning their chronic conditions, use of medication, and presence of depressive symptoms (evaluated using the Geriatric Depression Scale (GDS) questionnaire). The presence of any cognitive impairment was evaluated using the Mini-Mental State Examination (MMSE). Cardiac ultrasonography and electrocardiograms were done to evaluate the cardiac morphology and physiology. Their functional capacity was assessed with the WHO Global Physical Activity Questionnaire and the six-minute walk test. A self-paced step test was equally done to estimate the maximum oxygen consumption during aerobic exercise. We carried out aunivariate, and then multivariate analyses to identify factors associated with an altered functional status. Statistical analysis was performed using the SPSS software 23.0. The threshold of significance was set at 0.05. Results: 66 participants were included (35 women) with a median age of 70 (IQR: 67 - 75) years. Among them, 39.4% were found to have an altered functional capacity, about 87.8% had at least one chronic condition and 47% had two or more. The most prevalent chronic condition was hypertension (71.2%) followed by heart failure (24.2%) and osteoarthritis (12.1%). Mild depressive symptoms were present in 1.5% of our study population. The factors associated with an altered functional capacity include age ≥ 75 years (OR = 2.9 p heart failure (OR: 3.2, p ), osteoarthritis (OR: 5.1, p ), and poor gait and balance (OR: 3.7, p ). Conclusion: There is a high prevalence of altered functional capacity among elderly patients consulting at the Yaoundé Central Hospital. Heart failure, osteoarthritis, and an increased risk of falls are associated with an altered functional capacity.
文摘<strong>Background: </strong>Cardiac rehabilitation (CR) is a multifaceted treatment that can increase the survival and quality of life of cardiac patients by increasing their functional capacity (FC). In this study, we aimed to investigate the FC changes of cardiac patients after the CR program in different subgroups in terms of anthropometric, clinical, and psychological indices. <strong>Materials and Methods:</strong> This is a descriptive retrospective study that has been derived from the results of a Cohort study at the Rehabilitation Research Center of the Cardiovascular Research Institute of Isfahan (Iran), from 2006 to 2017. In this study, the dependent variable is functional capacity changes based on Mets obtained in exercise testing at the beginning and end of the CR program. Independent variables included age, sex, dyslipidemia, diabetes, smoking, and Body mass index, type of intervention, depression, and EF. <strong>Results:</strong> The sample size is 1250 cardiovascular patients, of which 917 (73.5%) are male and 331 (26.5%) are female. Functional capacity after the CR program significantly increased in all age, gender, body mass index, hypertension, hyperlipidemia, diabetes, smoking, depression, EF, and type of operation performed (angioplasty or open-heart surgery) subgroups, (p < 0.001). Using multiple linear regression analysis, a significant relationship was found between Mets changes and only the variables of gender, depression, and EF. <strong>Conclusion:</strong> The results of this study show the importance of rehabilitation programs in the secondary prevention of cardiovascular disease in different subgroups and factors such as gender, level of primary depression, and EF less than 35 are the most important factors affecting functional capacity increase after CR program in heart patients.
文摘Objectives: Psychosocial factors are important determinants of cardiovascular health outcomes in rehabilitation. However, the relationship between exercise performance and individual factors remained poorly understood. This study investigated the relationship between functional capacity and psychosocial correlates of exercise in Nigerian patients with hypertension. Study Design and Setting: This quasi-experimental study recruited 120 patients with hypertension (≥140/90 ≤ 179/109 mmHg) from the Cardiac Care Unit of a Nigerian university teaching using purposive sampling technique. Functional capacity was assessed using the 6-minute walk test and maximum oxygen consumption (VO<sub>2</sub> max) was estimated. Participants also underwent a 30-minute self-paced walking exercise. Thereafter, psychosocial correlates of exercise including exercise self-efficacy (ESE), social support (SoS), perceived exercise barrier (PEB) and socio-economic status (SES) were assessed using validated questionnaires. Descriptive and inferential statistics were used to analyze data. Alpha level was set at p < 0.05 of significance. Results: A majority of the participants demonstrated high ESE (75.0%), moderate SoS (60.9%) and low PEB (71.7%). More than half (58.4%) of the participants were in the middle SES. Male and female participants were comparable in ESE scores (p = 0.554), SoS (p = 0.362) and six-minute walk distance (6-MWD) (p = 0.194) except in body mass index (p < 0.05). The mean 6-MWD and VO<sub>2</sub> max were 350.6 ± 54.7 m and 9.74 ± 1.5 ml/kg/min respectively. There were significant correlations between functional capacity and each of ESE (r = 0.184;p = 0.026) and SoS (r = 0.374;p = 0.021). Conclusions: Psychosocial correlates of exercise including self-efficacy and social support were significantly associated with functional capacity among Nigerian patients with mild to moderate hypertension.
基金supported by the National Natural Science Foundation of China (30870263, 31272259)
文摘Background: Flight is the central avian adaptation in evolution. Wing muscles form an important anatomical basis for avian flight, affecting wing performance and determine modes of flight. However, the roles of distal muscles in adjusting the wing, as well as their functional specializations, remain largely unknown. The importance of muscle fiber architecture has long been recognized. In this study, we provide quantitative anatomical data on the muscle architecture of the forelimb of the Golden Pheasant(Chrysolophus pictus), with an emphasis on brachial,antebrachial and manual segments.Methods: The forelimbs of five Golden Pheasants were dissected and detailed measurements of all muscles were made, including muscle mass, muscle belly length, fascicle length. From these values, muscle volume, physiological cross-sectional area(PCSA) and maximum isometric force were derived.Results: General trends such as the distribution of muscle mass, fascicle length and the ratio of tendon length/belly length are revealed. Comparing PCSAs between antebrachial depressors and elevators and between intrinsics of the alular digit and major digit yielded significant differences(p < 0.05). Pronounced development of the antebrachial depressors suggests that ventral rotation of the distal half of the wing is a pivotal factor in shape change and orientation modulation. Large PCSAs in tandem with the force generation capability of the major digit intrinsics may help stabilize the digits while enhancing support of the primary feathers. The architectural properties of the alular digit confirm that alular adjustment is essential to rapid adduction and abduction.Conclusions: These observations illustrate the underlying structural basis for the functional capacities of the distal forelimb muscles and may provide additional information useful in further biomechanical and in vivo investigations.
文摘AIM: To examine the utility of Six Minute Walk Test (6MWT) in patients with chronic liver disease (CLD). METHODS: Two hundred and fifty subjects between the ages of 18 and 80 (mean 47) years performed 6MWT and the Six Minute Walk Distance (6MWD) was measured. RESULTS: The subjects were categorized into four groups. Group A (n = 45) healthy subjects (control); group B (n = 49) chronic hepatitis B patients; group C (n = 54) chronic hepatitis C patients; group D (n = 98) liver cirrhosis patients. The four groups differed in terms of 6MWDs (P < 0.001). The longest distance walked was 421 ± 47 m by group A, then group B (390 ± 53 m), group C (357 ± 72 m) and group D (306 ± 111 m). The 6MWD correlated with age (r = -0.482, P < 0.01), hemoglobin (r = +0.373, P < 0.001) and albumin (r = +0.311, P < 0.001) levels. The Child-Pugh classification was negatively correlated with the 6MWD in cirrhosis (group D) patients (r = -0.328, P < 0.01). At the end of a 12 mo follow-up period, 15 of the 98 cirrhosis patients had died from disease complications. The 6MWD for the surviving cirrhotic patients was longer than for non-survivors (317 ± 101 vs 245 ± 145 m, P = 0.021; 95% CI 11-132). The 6MWD was found to be an independent predictor of survival (P = 0.024). CONCLUSION: 6MWT is a useful tool for assessing physical function in CLD patients. We suggest that 6MWD may serve as a prognostic indicator in patients with liver cirrhosis.
文摘Functional capacity is the condition of an individual living independently and the lack of it for preparing and eating food, which is a factor that can result in malnutrition and deserves the attention of professionals and his family members. Then, the aim of this work was to evaluate the relationship between nutritional status and functional capacity for older adults using anthropometric measures and questionnaires for activities of daily and instrumental living. It was an epidemiological cross-sectional study using a representative sample of older adults selected from a previous study about quality of life in a Botucatu city, Sao Paulo. Brazil. The sample size was calculated considering 95% of reliability and 5% of error margin, resulting from a total of 365 individuals of both sexes but only 361 of them completed the protocol. Data included sociodemographic and morbidities questionnaires, activities of daily and instrumental living (ADL and IADL) and an-thropometric variables. 62.6% of the older were women, 44.68% were hypertensive, 28.81% were diabetic and 15.51% had hypercholesterolemia. 94.24% and 92.42% of the older were fully independent for ADL and IADL, respectively. Associations between ADL with marital status and schooling were found as well as with IADL. Also, it was found association with IADL and heart disease. Regarding anthropometry most of measures when compared men and women were significant. No significant association was found between nutritional status and ADL. A logistic regression model was fitted considering ADL as a response variable showed BMI as a protection factor and WC as a risk factor for dependence. For IADL, heart disease was a risk factor for dependence. In conclusion, low weight and increased waist circumference have influence in a functional capacity of older adults according to the activities daily living (ADL) and heart disease for IADL.
文摘Anemia in the elderly population has been associated to clinical manifestations such as functional dependence, low cognitive performance, increased mortality and geriatric syndromes (dementia, delirium, depression and falls). Recent investigations have shown an association between low hemoglobin levels, reduction in muscular strength and physical fitness. The objective of this review was to identify, in the scientific literature, evidence of an association between anemia and functional capacity among older persons. PubMed and Bireme were used as references source. The most relevant evidence pointing towards this association was identified in the epidemiological studies Women’s Health and Aging Studies I and II (WHAS I and II). Functional capacity was evaluated by the walking, balance and sitting back and getting out of the chair tests. Elderly women with either 13 or 14 g/dl have a better performance compared to women with 12 g/dl of hemoglobin, respectively. This study also reported an increase in the mortality risk among women (65 years old and plus) living in community with less than 13.4 g/dl of hemoglobin. Participants were followed for 11 years. WHAS I and II investigators suggested a new criterion, already adopted by the World Health Organization (WHO), to define anemia among elderly women. Conclusion: anemia is common among the elderly and may have an involvement in the impairment of their functional capacity. However, in spite of the importance of these findings, it should be emphasized that an etiologic association (anemia as a cause of functional impairment) has yet to be demonstrated.
基金supported by grants from the National Natural Science Foundation of China(81873492 and 82070373).
文摘Objective:Arterial stiffness is an important predictor of cardiovascular disease.Microbial diversity in the gut has been shown to be associated inversely with arterial stiffness in Caucasian populations.However,due to the different profiles of the gut microbiota among ethnicities,the relationship between gut-microbiota dysbiosis and the progression of arterial stiffness merits further investigation.This study aimed to investigate the association between the composition and functional capacity of the gut microbiota and the progression of arterial stiffness.Methods:“Shotgun”metagenomics sequencing were undertaken in 96 individuals from a hypertension-associated gut-microbiota study in the Kailuan cohort,who measured brachial-ankle pulse wave velocity(baPWV)and provided fecal samples between September 2014 and February 2015 at Kailuan General Hospital and 11 affiliated hospitals.The different composition and functional capacity of the gut microbiota were compared between individuals without arterial stiffness(normal arterial stiffness group,baPWV<1,400 cm/s,n=27)and participants with arterial stiffness(increased arterial stiffness group,baPWV≥1,400 cm/s,n=69)at baseline.These participants were followed up prospectively for a mean duration of 2.6 years,and 50 underwent a repeat baPWV measurement.Associations between the gut microbiota and severity and progression of arterial stiffness were assessed using MaAsLin2 software after adjustment for age,sex,and mean arterial blood pressure and correction for multiple testing.Gene“catalogs”were aligned to the Kyoto Encyclopedia of Genes and Genomes(KEGG)database to obtain information for potential functional capacities of the gut microbiota.Results:In this study,14 genera and 50 species of bacteria were identified to be abundant in participants with normal arterial stiffness compared with those with increased arterial stiffness.Of 14 genera,the prevalence of beneficial bacteria of the genera Leadbetterella and Cytophaga was correlated inversely with baPWV(P<0.05).Analyses of functional capacity revealed gut-microbial dysfunctions in the synthetic processes of“threonine dehydratase”“hypothetical protein”“mannosyl transferase”and“type-IV secretion-system proteins”in individuals suffering from arterial stiffness.During follow-up,bacteria of the proinflammatory genera Escherichia,Shigella,and Ruegeria were enriched in individuals with increased baPWV.Functional analyses showed that 26 KEGG orthologs of gut microbes were associated with an increase in baPWV and involved in“carbohydrate metabolism”“amino acid metabolism”and“protein families related to genetic information processing.”Conclusions:The composition and functional capacity of the microbial community in the gut of people suffering from arterial stiffness differed from those in individuals not suffering from arterial stiffness.Our data provide a new direction for the causality of the host-gut microbiota in arterial stiffness.
文摘Our brain is constantly active.Even at rest,the brain carries out essential functions such as maintenance of resting potentials,subthreshold synaptic activity,and spiking activity related to information processing.This resting activity can be assessed with several in vivo tools,such as resting-state functional magnetic resonance imaging.This technique measures subtle changes in blood flow,volume,and oxygenation that occur over time.Although vascular in nature,resting-state functional magnetic resonance imaging is considered a reliable proxy of neural activity and several studies have shown that the brain is functionally divided into interacting neural networks called the“functional connectome”.
文摘Functional magnetic resonance imaging(fMRI)is a popular tool used to investigate not only how the brain responds to specific stimuli during sensorimotor or cognitive tasks,but also brain activity at rest.The physics beyond this approach is based on the analysis of the blood oxygenation level-dependent signal.
基金supported by the National Natural Science Foundation of China (52075420)the National Key Research and Development Program of China (2020YFB1708400)。
文摘With its generality and practicality, the combination of partial charging curves and machine learning(ML) for battery capacity estimation has attracted widespread attention. However, a clear classification,fair comparison, and performance rationalization of these methods are lacking, due to the scattered existing studies. To address these issues, we develop 20 capacity estimation methods from three perspectives:charging sequence construction, input forms, and ML models. 22,582 charging curves are generated from 44 cells with different battery chemistry and operating conditions to validate the performance. Through comprehensive and unbiased comparison, the long short-term memory(LSTM) based neural network exhibits the best accuracy and robustness. Across all 6503 tested samples, the mean absolute percentage error(MAPE) for capacity estimation using LSTM is 0.61%, with a maximum error of only 3.94%. Even with the addition of 3 m V voltage noise or the extension of sampling intervals to 60 s, the average MAPE remains below 2%. Furthermore, the charging sequences are provided with physical explanations related to battery degradation to enhance confidence in their application. Recommendations for using other competitive methods are also presented. This work provides valuable insights and guidance for estimating battery capacity based on partial charging curves.
基金the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(2020R1A2C1A01011131)the Energy Cloud R&D Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT(2019M3F2A1073164).
文摘Base isolators used in buildings provide both a good acceleration reduction and structural vibration control structures.The base isolators may lose their damping capacity over time due to environmental or dynamic effects.This deterioration of them requires the determination of the maintenance and repair needs and is important for the long-termisolator life.In this study,an artificial intelligence prediction model has been developed to determine the damage and maintenance-repair requirements of isolators as a result of environmental effects and dynamic factors over time.With the developed model,the required damping capacity of the isolator structure was estimated and compared with the previously placed isolator capacity,and the decrease in the damping property was tried to be determined.For this purpose,a data set was created by collecting the behavior of structures with single degrees of freedom(SDOF),different stiffness,damping ratio and natural period isolated from the foundation under far fault earthquakes.The data is divided into 5 different damping classes varying between 10%and 50%.Machine learning model was trained in damping classes with the data on the structure’s response to random seismic vibrations.As a result of the isolator behavior under randomly selected earthquakes,the recorded motion and structural acceleration of the structure against any seismic vibration were examined,and the decrease in the damping capacity was estimated on a class basis.The performance loss of the isolators,which are separated according to their damping properties,has been tried to be determined,and the reductions in the amounts to be taken into account have been determined by class.In the developed prediction model,using various supervised machine learning classification algorithms,the classification algorithm providing the highest precision for the model has been decided.When the results are examined,it has been determined that the damping of the isolator structure with the machine learning method is predicted successfully at a level exceeding 96%,and it is an effective method in deciding whether there is a decrease in the damping capacity.
基金supported by the National Natural Science Foundation of China under Grant Nos.12122401 and 12074007.
文摘In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at extremely high temperatures.However,stochastic density functional theory(SDFT)can overcome this limitation.Recently,SDFT and the related mixed stochastic–deterministic density functional theory,based on a plane-wave basis set,have been implemented in the first-principles electronic structure software ABACUS[Q.Liu and M.Chen,Phys.Rev.B 106,125132(2022)].In this study,we combine SDFT with the Born–Oppenheimer molecular dynamics method to investigate systems with temperatures ranging from a few tens of eV to 1000 eV.Importantly,we train machine-learning-based interatomic models using the SDFT data and employ these deep potential models to simulate large-scale systems with long trajectories.Subsequently,we compute and analyze the structural properties,dynamic properties,and transport coefficients of warm dense matter.
