•Machine learning based methodology for power transformer health assessment.•ANFIS for detection of power transformer inter-turn faults.•Unsupervised ML for classifying transformers of similar age ...and failure probability.•ANN used for prediction of fault severity based on SFRA statistical indicators.•Real-time CBs health assessment for ranking and predictive maintenance planning.
This paper presents machine learning methods for health assessment of power transformer based on sweep frequency response analysis. The paper presents an overview of monitoring and diagnostics based on statistical Sweep Frequency Response Analysis (SFRA) based indicators that are used to evaluate the state of the power transformer. Experimental data obtained from power transformers with internal short-circuit faults is used as a database for applying machine learning. Machine learning is implemented to achieve more precise asset management and condition-based maintenance. Unsupervised machine learning was applied through the k-means cluster method for classifying and dividing the examined power transformer state into groups with similar state and probability of failure. Artificial neural network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) as part of supervised machine learning are created in order to detect fault severity in tested power transformers of different lifetime. The presented machine learning methods can be used to improve health assessment of power transformers.
The elite judo female athlete’s heart Milovančev, Aleksandra; Petrović, Milovan; Miljković, Tatjana ...
Frontiers in physiology,
08/2022, Letnik:
13
Journal Article
Recenzirano
Odprti dostop
Purpose:
There is a paucity of data on physiological heart adaptation in elite-level judo female athletes. This study aimed to assess left ventricular morphology and function in highly trained elite ...female judokas.
Methods:
The study prospectively included 18 females aged 23.5 ± 2.25 years, nine elite level judokas, and nine healthy non-athlete volunteers. All participants underwent a medical examination, electrocardiogram, and transthoracic 2D echocardiogram. Left ventricular diastolic and systolic diameters and volumes were determined, and parameters of left heart geometry and function (systolic and diastolic) were measured, calculated, and compared between groups.
Results:
When groups were compared, judokas had significantly increased left ventricular cavity dimensions
p
< 0.01, left ventricular wall thickness
p
< 0.01, and volumes
p
< 0.01. Elite female judokas exhibited left ventricular dilatation demonstrated as high prevalence increased end-diastolic volume/index, and increased end-systolic volume/index in 88.9% of judokas vs. 0% in controls,
p
< 0.01. Left ventricle mass/index was significantly increased in judokas,
p
< 0.01), with a 43.3% difference between groups. The majority (77.7%) of judokas had normal left ventricular geometry, although eccentric hypertrophy was revealed in 2 (22.2%) of judokas.
Conclusion:
Elite, highly trained female judokas exhibit significant changes in left heart morphology as a result of vigorous training compared to non-athletes. These findings suggest that female judokas athletes’ heart follows a pattern toward chamber dilatation rather than left ventricular wall hypertrophy.
This paper examines speech privacy in both residential and commercial spaces. The ASTM E2638 standard defines the Speech Privacy Class (SPC) parameter, which measures speech privacy based on the ...signal-to-noise ratio at the listener’s position. This paper proposes estimating the SPC value using relevant ISO parameters commonly used in European practice: the apparent sound reduction index in dB (defined by ISO 16283-1, 2 standards) and the equivalent ambient noise level in dBA (defined by the ISO 1996-1 standard). The estimated value of the SPC parameter in this paper is referred to as the Speech Privacy Index (SPI). A diverse range of situations, i.e., rooms, was analyzed in the field. These rooms varied in terms of purpose, organization, dimensions, furnishings, isolation from other spaces, and internal and external environments. The results of the experiments demonstrate a strong correlation between the SPC value estimated according to ISO parameters (the proposed method) and the SPC as defined in the ASTM E standard. This indicates that the proposed method can provide an indicator of the state of speech privacy in buildings. The significance of the proposed calculation method (i.e., the STI parameter) lies in its ability to be applied at the building design stage, as well as after its completion, during routine testing.
The worldwide problem of infectious diseases has appeared in recent years, and antimicrobial agents are crucial in reducing disease emergence. Nevertheless, the development and distribution of ...multidrug-resistant (MDR) strains in pathogenic bacteria, such as
,
,
and
, has become a major society health hazard. Essential oils could serve as a promising tool as a natural drug in fighting the problem with these bacteria. The current study aimed to investigate the antimicrobial effectiveness of tea tree (
(Maiden and Betche) Cheel), rosemary (
L.), eucalyptus (
L'Hér.), and lavender (
Mill) essential oils. The antimicrobial properties of essential oils were screened against four pathogenic bacteria,
,
,
and
, and two reference bacterial strains, while for the testing, the agar well diffusion method was used. Gas chromatography (GC) and gas chromatography-mass spectrometric (GC-MSD) analyses were performed on essential oils. The obtained results showed that
essential oil is the richest in terpinen-4-ol,
and
essential oils in 1,8-cineole, and
essential oil in α-terpinyl acetate. In addition, the main bioactive compounds present in the essential oil of tea tree are rich in α-pinene (18.38%), limonene (7.55%) and γ-terpinene (14.01%). The essential oil of rosemary is rich in α-pinene (8.38%) and limonene (11.86%); eucalyptus essential oil has significant concentrations of α-pinene (12.60%),
-cymene (3.24%), limonene (3.87%), and γ-terpinene (7.37%), while the essential oil of lavender is rich in linalool (10.71%), linalool acetate (9.60%), α-terpinyl acetate (10.93%), and carbitol (13.05%) bioactive compounds, respectively. The obtained results from the in vitro study revealed that most of the essential oils exhibited antimicrobial properties. Among the tested essential oils, tea tree was discovered to demonstrate the strongest antimicrobial activity. The recorded MIC of
was 6.2 mg/mL, 3.4 mg/mL of
, 3.1 mg/mL of
, and 2.7 mg/mL of
ATCC 25922, compared to
. Similarly, only
ATCC 25923 showed antimicrobial activity towards
(1.4 mg/mL),
(2.9 mg/mL), and
(2.1 mg/mL). Based on the obtained results, it is possible to conclude that tea tree essential oil might be used as an ecological antimicrobial in treating infectious diseases caused by the tested pathogens.
: Pulmonary valve infective endocarditis (PVIE) is a rare form of infective endocarditis (IE) and is associated with high mortality and severe complications. Guidelines for treatment of this form of ...IE are scarce and based on general recommendations. We report a case series of PVE.
: Case 1-A 36-year-old female with congenital pulmonary artery stenosis, dyspnea and leg edema symptoms for 2 months. Blood cultures yielded
spp. and
sp., and echocardiography revealed multiple floating vegetation at the pulmonic valve and surrounding structures. The clinical course was complicated with sepsis and multi-organ failure. Urgent surgery with pulmonary homograft implantation resulted in successful five-year outcome. Case 2-In a 38-year-old male with previous tetralogy of Fallot correction and symptoms of fatigue, fever, myalgia, and photophobia, echocardiography was suggestive of PVIE. The clinical course was complicated with septic shock, multi-organ failure, ischemic stroke with hemorrhagic transformation and death on the 12th day of hospitalization. Case 3-A 41-year-old male without previous medical history was hospitalized due to prolonged fatigue, fever, dyspnea, and leg edema. He was diagnosed with multi-valve infective endocarditis, affecting the aortic, tricuspid, and pulmonary valve. Acute heart failure and hemodynamic instability indicated urgent surgery with aortic valve replacement and reconstruction of the tricuspid and pulmonary valves. At four-year follow up he was doing well.
: Symptoms in PVIE may be versatile, and diagnosis is often delayed. High level of suspicion, early recognition, and echocardiography are cornerstones in diagnostics. Despite the standpoint that medical therapy is first-line, the role of surgery needs to be advocated in particular cases.
In 2020, decreased emergency department (ED) visits and hospitalization rates during the COVID-19 outbreak were reported. There is no data about cardiovascular emergencies and mortality for the whole ...COVID-19 year.This study aimed to compare the rates of cardiology ED visits, hospital admissions, and intrahospital mortality between the pre-COVID-19 and COVID-19 years in a single high-volume center.The retrospective observational cross-sectional study analyzed data on the number of ED visits, hospital admissions by different cardiovascular diagnoses, and outcomes.A total of 11744 patients visited the cardiology ED in the pre-COVID-19 year compared with 9145 in the COVID-19 year, indicating an overall decrease of 22.1% (P = 0.02) (IR 78.76 versus 61.33; incidence rate ratios (IRR) 1.28, P = 0.00), with an observed decrease of 25.5% in the number of hospitalizations (33.1% versus 31.6%, P = 0.02). A marked decrease in hospitalizations for cardiovascular emergencies was observed for hypertensive heart disease (−72.8%, P < 0.0001), acute coronary syndrome (−17.8%, P < 0.0001), myocardial and pericardial diseases and endocarditis (−61.2%, P = 0.00), and valvular heart disease (−70.8%, P < 0.0001). In the COVID-19 year, patients had increased need for mechanical ventilatory support (7% versus 6.3%, P = 0.03) with no overall difference in intrahospital mortality (IR 2.71 versus 2.78, IRR 0.98, 95% CI 0.82-1.16, P = 0.39).Decreased ED visits and hospitalizations not just in outbreaks but through the whole COVID-19 year highlight the risk of continuous delay of needed care for emergency life-threatening cardiovascular diseases. Urgent comprehensive strategies that will address patient- and system-related factors to decrease morbidity and mortality and prevent collateral damage of the pandemic are needed.
There is emerging evidence of the usefulness of left atrial strain (LAS) in the assessment of diastolic dysfunction (DD). In this study we assess the sensitivity and specificity of LAS, to determine ...cut-off values and their association to DD with increased left atrial pressure (LAP) in patients with well-treated arterial hypertension.
We performed a cross-sectional study on 180 subjects with well-treated arterial hypertension. All patients underwent transthoracic echocardiography. Patients were divided into two groups: a group without increased LAP and/or DD and a group with increased LAP DD.
In multivariate logistic regression, LAS proved to be the strongest statistically significant predictor of DD with increased LAP (OR 0.834,
< 0.0005), with AUC 0.885 and a set cut-off value of 24.27% with high sensitivity of 78.9% and specificity of 84.6%. The set cut-off for LAS > 24.27% was significantly highly prevalent in the group of DD with increased LAP 78.9% when compared to the group without increased LAP 15.4%,
< 0.0001.
The findings of this study suggest that LAS could be a useful and highly sensitive and specific marker in the evaluation of DD. There is the potential for using LAS in everyday practice as a standard parameter in diastolic function assessment.
as a relatively high number of ST-segment elevation myocardial infarction (STEMI) patients develop major adverse cardiovascular events (MACE) following percutaneous coronary intervention (PCI), our ...aim was to determine the significance, and possible predictive value of QRS complex width and ST-segment elevation.
our patient sample included 200 PCI-treated STEMI patients, which were divided into two groups based on the following duration of symptoms: (I) less than 6 h, and (II) 6 to 12 h. For every patient, an ECG was performed at six different time points, patients were followed for up to six years for the occurrence of MACE.
the mean age was 60.6 ± 11.39 years, and 142 (71%) were male. The 6-12 h group had significantly wider QRS complex, higher ST-segment elevation, lower prevalence of ST-segment resolution as well as MACE prevalence (
< 0.05). ECG parameters, QRS width, and magnitude of ST-segment elevation were proved to be independent significant predictors of MACE in all measured time points (
< 0.05). Even after controlling for biomarkers of myocardial injury, these ECG parameters remained statistically significant predictors of MACE (
< 0.05).
our study highlights that wider QRS complex and a more pronounced ST-segment elevation are associated with longer total ischemic time and higher risk of long-term MACE.
Physiological heart adaptations may lead to increased susceptibility to arrhythmia in athletes. Furthermore, vigorous training and method like rapid weight loss (RWL) in combat sports could pose ...additional risks. This case represents how routine cardiovascular screening during high-risk methods like RWL and high-intensity training (HIT) reveal abrupt ventricular arrhythmias in a young athlete.
We report a case of a 20-year-old male wrestler athlete who developed disrupting arrhythmia during RWL and HIT. The study included: a medical exam, 12 lead electrocardiograms (ECG), transthoracic echocardiogram (ECHO), and 24 h of continuous ECG monitoring in baseline, phase one (P1), (in which the athlete had to simulate RWL through vigorous training and dietary intervention and HIT) and phase two (P2), (with the same HIT protocol performed without the RWL procedure). Baseline laboratory analyses were without abnormalities, ECG showed sinus rhythm with one premature atrial contraction (PAC) and ECHO showed signs of concentric remodeling with preserved systolic, diastolic function, and global longitudinal strain. After P1 RWL simulation, he lost 5.15% of body weight in 3 days, which resulted in lower blood glucose levels, higher urea, creatinine, creatine kinase (CK), CK-MB levels, and slightly increased levels of NT pro-BNP, ECG revealed sinus rhythm with one ventricular premature beat (VPB), 24-h continuous electrocardiogram (ECG) revealed frequent ventricular premature beats (PVB) 2,150/ 24 h, with two couplets, and 8 PAC. After an advised 4-week period of de-training continuous 24 h, ECG monitoring was improved with only occasional PVB. The 24 h continuous ECG monitoring was repeated after HIT and revealed even more frequent PVB, 5% of all beats for 24 h, 4,205 in total, and almost all VPB were in bigeminy and trigeminy. The athlete was advised against RWL and extremely vigorous exercise and for regular, frequent checkups with occasional ECG monitoring during and after exercise.
The short and long-term implication of abrupt ventricular arrhythmias provoked by intensive training and methods like RWL is unknown. We postulate that cardiovascular screening is necessitated, especially during high-risk methods like RWL and HIT, in helping us prevent adverse outcomes and come to individual-based clinical making decisions for each athlete.
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