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In the risk assessment of cascading outages, the rationality of simulation and efficiency of computation are both of great significance. To overcome the drawback of sampling-based methods that huge computation resources are required and the shortcoming of initial contingency selection practices that the dependencies in sequences of outages are omitted, this paper proposes a novel risk assessment approach by searching on Markovian Tree. The Markovian tree model is reformulated from the quasi-dynamic multitimescale simulation model proposed recently to ensure reasonable modeling and simulation of cascading outages. Then, a tree search scheme is established to avoid duplicated simulations on same cascade paths, significantly saving the computation time. To accelerate the convergence of a risk assessment, a risk estimation index is proposed to guide the search for states with major contributions to the risk, and the risk assessment is realized based on the risk estimation index with a forward tree search and backward update algorithm. The effectiveness of the proposed method is illustrated on a four-node power system, and its convergence profile as well as efficiency is demonstrated on the RTS-96 test system. [ABSTRACT FROM AUTHOR]

Purpose: To establish a single-nucleotide polymorphism-based analysis (SBA) method to identify triploidy in the miscarriage tissue by using low-coverage whole-genome sequencing (LC-WGS). Methods: The method was established by fitting a quadratic curve model by counting the distribution of three heterozygous mutation content intervals. The triploid test result was mainly determined by the opening direction and the axis of symmetry of the quadratic curve, and Z test between the same batch samples was also used for auxiliary judgment. Results: Two hundred thirteen diploid samples and 8 triploid samples were used for establishment of the analytical method and 203 unknown samples were used for blind testing. In the blind testing, we found 2 cases positive for triploidy. After chromosome microarray analysis (CMA) and mass spectrometry verification, we found that both samples were true positives. We randomly selected 5 samples from the negative samples for mass spectrometry verification, and the results showed that these samples were all true negatives. Conclusions: Our method achieved accurate detection of triploidy in the miscarriage tissue and has the potential to detect more chromosomal abnormality types such as uniparental disomy (UPD) using a single LC-WGS approach. [ABSTRACT FROM AUTHOR]

• This paper establishes a small signal model of variable speed pumped storage unit with full size converter. • The oscillation modes and key influencing factors are clarified. • A coordinated control strategy for suppressing the ultra-low frequency oscillation is proposed. The research on control strategies of the variable speed pumped storage unit with full size converter (FSC-VSPSU), mainly focuses on the rapidity of power regulation. But the speed oscillation and slow speed regulation performance caused by fast power regulation are ignored, which is not conducive to the safe and efficient operation of the unit. This article investigates the dynamic stability characteristics of the FSC-VSPSU in detail. In turn, the stability risks are clarified and serve for the design of its control strategy and the improvement of operational efficiency. The small-signal model of FSC-VSPSU considering the variation of water head and load in fast power mode is established. The dominant instability control link and key parameters are revealed based on the eigenvalue analysis. Oscillation mode analysis shows that the unit has a wide-band oscillation characteristic. The dominant oscillation mode is the ultra-low frequency oscillation (ULFO) caused by the governor control system. To suppress the ULFO and improve the optimal speed tracking performance of the unit to the greatest extent, a coordinated control strategy of governor variable parameter control and governor power system stabilizer (GPSS) is proposed. The electromagnetic transient simulation based on PSCAD verifies the effectiveness of the proposed measures. [ABSTRACT FROM AUTHOR]

Background and Objectives: Chinese women in rural areas who are currently >=55 years old have experienced extreme undernutrition during their childbearing age. Their specific experiences provided us with a natural quasiexperimental field for assessing the effects of consuming eggs to obtain nutrients during the childbearing period on preventing nonfatal coronary events (NCE) during the postmenopausal period in the framework of life course epidemiology.Methods and Study Design: A population-based matched case-control design for NCE was conducted in Yiyuan County, Shandong Province, China. In this study, 462 women with NCE (cases; onset age >=55 years) were included from the Active Surveillance System for Chronic Diseases, and 462 age-matched women without NCE and stroke (controls) from the same village were included. Conditional logistic model analysis was used to determine the association between egg intake and NCE during the postmenopausal period in 3 specific life-periods, namely age 18 to 49 years (childbearing period), age 50 years to NCE onset (perimenopausal and postmenopausal period), and age 18 years to NCE onset (total period).Results: We found that >=12 eggs vs. 0 egg intake per month under extreme undernutrition status during childbearing period exhibited a strong preventive effect against NCE during the postmenopausal period (OR=0.588, 95% CI=0.358-0.964). The window of protective effect was in the age 28 to 49 years, suggesting a critical period model of life course epidemiology.Conclusions: Egg intake under extreme undernutrition status during the childbearing period plays a critical role in preventing NCE during the postmenopausal period. [ABSTRACT FROM AUTHOR]

• An intermediate band is inserted in the band gaps of these Kesterite compounds after Sb doping. • Sb-doped AZTS as the promising absorber candidate for IBSC has been proposed. • The suitable growth condition for Sb doping in these Kesterite compounds has been suggested. Intermediate band solar cells(IBSCs) have attracted much attention owing to the ideal three-photon absorption by one absorber. Here, we have investigated Sb-doped Cu 2 ZnSnS 4 (CZTS), Cu 2 ZnGeS 4 (CZGS), Ag 2 ZnSnS 4 (AZTS) and Ag 2 ZnGeS 4 (AZGS) as the absorber for IBSCs by first-principles calculation. After doping Sb at Sn or Ge site, an isolated and half-filled intermediate band has been inserted in the main band gaps of all of the four Kesterite compounds, which mainly consists of Sb-s and S-p states. The absorption coefficients of the doped samples are greatly enhanced in visible light region and can cover the solar radiation spectrum effectively owing to the three-photon absorption with the help of intermediate band. Based on the calculation on defect formation energy, we have found the suitable chemical potential condition and gotten the minimums of defect formation energies for Sb doping at Sn or Ge site. Finally, Sb-doped AZTS as the promising absorber candidate for IBSCs has been proposed. [ABSTRACT FROM AUTHOR]

Introduction: Electromyography (EMG) normalization often relies on maximum voluntary isometric contraction (MVIC), which may not be suitable for knee osteoarthritis (KOA) patients due to difficulties in generating maximum joint torques caused by pain. This study aims to assess the reliability of standard isometric contraction (SIC) for EMG normalization in older adults with KOA, comparing it with MVIC. Methods: We recruited thirty-five older adults with KOA and collected root mean square EMG amplitudes from seven muscles in the affected limb during level walking, SIC, and MVIC tests. EMG data during level walking were normalized using both SIC and MVIC methods. This process was repeated after at least 1 week. We calculated intra-class correlation coefficients (ICCs) with 95% confidence intervals to evaluate between- and within-day reliabilities. Results: SIC tests showed higher between- (ICC: 0.75-0.86) and within-day (ICC: 0.84-0.95) ICCs across all seven muscles compared to MVIC tests. When normalized with SIC, all seven muscles exhibited higher between- (ICC: 0.67-0.85) and within-day (ICC: 0.88-0.99) ICCs compared to MVIC normalization. Conclusion: This study suggests that SIC may offer superior movement consistency and reliability compared to MVIC for EMG normalization during level walking in older adults with KOA., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Zhu, Pang, Li, Sun, Ding, Song and Shen.)

Background: Ideal cardiovascular health (CVH) can be assessed by 7 metrics: smoking, body mass index, physical activity, diet, hypertension, dyslipidemia and diabetes, proposed by the American Heart Association. We examined the association of ideal CVH metrics with risk of all-cause, CVD and non-CVD death in a large cohort., Methods: A total of 29,557 participants in the Swedish National March Cohort were included in this study. We ascertained 3,799 deaths during a median follow-up of 19 years. Cox regression models were used to estimate hazard ratios with 95% confidence intervals (95% CIs) of the association between CVH metrics with risk of death. Laplace regression was used to estimate 25th, 50th and 75th percentiles of age at death., Results: Compared with those having 6-7 ideal CVH metrics, participants with 0-2 ideal metrics had 107% (95% CI = 46-192%) excess risk of all-cause, 224% (95% CI = 72-509%) excess risk of CVD and 108% (31-231%) excess risk of non-CVD death. The median age at death among those with 6-7 vs. 0-2 ideal metrics was extended by 4.2 years for all-causes, 5.8 years for CVD and 2.9 years for non-CVD, respectively. The observed associations were stronger among females than males., Conclusions: The strong inverse association between number of ideal CVH metrics and risk of death supports the application of the proposed seven metrics for individual risk assessment and general health promotion., (© 2024. The Author(s).)

Background: Traditional risk evaluation models have been applied to guide public health and clinical practice in various studies. However, the application of existing methods to data sets with missing and censored data, as is often the case in electronic health records, requires additional considerations. We aimed to develop and validate a predictive model that exhibits high performance with data sets that contain missing and censored data., Methods and Results: This is a retrospective cohort study of coronary heart disease at Weihai Municipal Hospital on unique patients aged 18 to 96 years between 2013 and 2021. A total of 169 692 participants formed our study population, of which 10 895 participants were diagnosed with coronary heart disease. Models were built for the risk of coronary heart disease based on demographic, laboratory, and medical history variables. All complete samples were assigned to the training set (n=110 325), whereas the remaining samples were assigned to the validation set (n=59 367). The area under the receiver operating characteristic curve value was 0.800 (95% CI, 0.794-0.805), and the C statistic was 0.796 (95% CI, 0.791-0.801) in the derivation cohort, and the corresponding values were 0.837 (95% CI, 0.821-0.853) and 0.838 (95% CI, 0.822-0.854) in the validation cohort. The calibration curve demonstrated its good calibration ability, and decision curve analysis showed its clinical usefulness., Conclusions: Our proposed risk prediction model has demonstrated significant effectiveness in handling the complexities of electronic health record data, which often involve extensive missing data and censoring. This approach may offer potential assistance in the use of electronic health records to enhance patient outcomes.

Background: Evidence regarding the association between metabolism-related indicators and serum urate (SU) is limited. We aimed to obtain the incidence density of hyperuricemia and to explore the association between metabolism-related predisposing risk factors and SU., Methods: A total of 48,979 Chinese adults from the Beijing Physical Examination Center were included in the study. The partial least squares path model was used to explore the relationship between SU and metabolism-related risk factors. The generalized additive model was used for smooth curve fitting, showing the sex-specific associations of SU at follow-up with baseline fasting blood glucose (FBG) concentrations and age., Results: The incidence density of hyperuricemia was 78/1000 person-years. Baseline SU, age, sex, obesity, FBG, and lipid metabolism were significantly associated with SU at follow-up (all P values <0.05). Non-linear relationships were found between the baseline FBG concentrations and SU at follow-up, while U-shaped associations were observed between baseline age and SU at follow-up., Conclusions: The SU concentration is associated with several metabolism-related risk factors such as obesity and FBG. Recognition of these associations will aid in a deeper understanding of the multifaceted nature of SU regulation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Liang, Zhang, Yu, Ding, Liu and Wang.)

Background and Objectives: Chinese women in rural areas who are currently >=55 years old have experienced extreme undernutrition during their childbearing age. Their specific experiences provided us with a natural quasiexperimental field for assessing the effects of consuming eggs to obtain nutrients during the childbearing period on preventing nonfatal coronary events (NCE) during the postmenopausal period in the framework of life course epidemiology., Methods and Study Design: A population-based matched case-control design for NCE was conducted in Yiyuan County, Shandong Province, China. In this study, 462 women with NCE (cases; onset age >=55 years) were included from the Active Surveillance System for Chronic Diseases, and 462 age-matched women without NCE and stroke (controls) from the same village were included. Conditional logistic model analysis was used to determine the association between egg intake and NCE during the postmenopausal period in 3 specific life-periods, namely age 18 to 49 years (childbearing period), age 50 years to NCE onset (perimenopausal and postmenopausal period), and age 18 years to NCE onset (total period)., Results: We found that >=12 eggs vs. 0 egg intake per month under extreme undernutrition status during childbearing period exhibited a strong preventive effect against NCE during the postmenopausal period (OR=0.588, 95% CI=0.358-0.964). The window of protective effect was in the age 28 to 49 years, suggesting a critical period model of life course epidemiology., Conclusions: Egg intake under extreme undernutrition status during the childbearing period plays a critical role in preventing NCE during the postmenopausal period.