[Objective] To analyze the multiple clinical factors on affect brachial-ankle pulse wave velocity(baPWV) .[Methods] 278 healthy were enrollcd randomly and measured left and right baPWV with Japan's COLIN arteriosclerosis instrument.People were divided into four groups based on the value of baPWV:﹤1 400 cm / s as group one(the normal group);1 400-1 600 cm / s as group one;1 600-1 800 cm / s as group three;﹥1 800 cm / s as group four.Clinical data were collected and to be statistical analysed among the four groups.[Results] ① When compare group one with group two to four, there was no significant difference with total cholesterol(TCH), high density lipoprotein cholesterol(HDL), and low density lipoprptein cholesterol(LDL)(P ﹥ 0.05).On the contrast, the level of age, systolic blood pressure(SBP) , diastolic blood pressure(DBP), mean artery pressure(MAP), pulse pressure(PP), fasting blood glucose(Glu), brachial-ankle pulse wave velocity(baPWV) were significantly higher than that in control group(P﹤0.05).With the level of baPWV increasing, all the indexes above were increasing(P﹤0.05).② Age, SBP, DBP, MAP, PP, HR, Glu and LDL were significant correlated with baP-WV by partial correlated analysed.③ A stepwise multiple regression analysis demomestrated that SBP, HR and age were positively related to baPWV(P﹤0.001).[Conclusion] Age, SBP, DBP, MAP, PP, HR, Glu and LDL were significant correlated with baPWV.Especially SBP, HR and age were positively related to baPWV.The SBP, HR and age were important risk factors for artery elasticity.
Series connection is an attractive approach to increase the blocking voltage of SiC power MOSFETs. Currently, the voltage balancing design of the series connection of the SiC MOSFETs highly relies on offline calibration and is challenging in the complex field operation. In this paper, a quantitative model to assess the voltage balancing performance is proposed to achieve a clear mathematical interpretation of the dynamic response of the voltage imbalance control loop. To begin with, an analytical model of the drain-source voltage rising time during the turn-off transient concerning the non-constant Miller plateau is proposed. Based on the turn-off model of the single device, the voltage imbalance sensitivity (VIS) is proposed to describe the influence of the parameters on the gate driving signals on the voltage imbalance. The VIS parameter can be easily achieved from the behavior of single devices, abandoning the complex variables in series connection. Further, for the typical case, active time delay voltage balancing methods are selected to demonstrate the application of the VIS analysis method. Based on VIS, the accurate close-loop design is proposed for controlling the delayed time among the devices. The proposed analysis and method are verified in simulation and experiment. The paper offers a generalized approach to assess the performance and the design of the series connection of the SiC MOSFETs, which can be further applied in many other methods for parameter design and engineering applications.
The medium-voltage (MV) dual active bridge (DAB) converter with series-connected SiC (S-SiC) MOSFETs is a promising solution for high-power-density isolated dc/dc converter. To improve the voltage sharing and reliability of S-SiC, relatively large snubber capacitors are connected in parallel with S-SiC. However, this narrows the zero voltage switching-ON (ZVS-ON) range of S-SiC and even reduces the efficiency and reliability of the entire converter. Adding a nonoptimized internal phase shift angle to the low-voltage (LV) side switching unit will result in excessive circulating power and still lead to low efficiency. In this article, the phase shift angle segmentation modulation (PSSM) scheme featuring soft-switching performance is proposed for an MV DAB converter with S-SiC. The proposed modulation scheme is based on a detailed derivation of the ZVS-ON range and operation modes. Then, the changes in operation characteristics and the advantages brought by the proposed modulation scheme are analyzed in terms of transmission power, state transition process, switching current, and device losses. Moreover, the introduced modes and ZVS-ON characteristics are verified on the 4-/1-kV 200-kW experimental prototype. As a result, the converter's loss can be decreased by up to 75% under light load, validating the efficiency advantage of the proposed modulation scheme.
Objective To establish the distribution of serum N-terminal pro-brain natriuretic.Methods NT-proBNP measure and medical record in 315 apparently healthy individuals(190 male and 125 female)Were performed.Results Within the health individuals,the distributio of NT-proBNP differed by age and gender.The reference range NT-proBNP was150ng/L for women and 92ng/L for men aged 65 years and 160ng/L for women and 116ng/L for men aged ≥65 years.Conclusion Healthy individuals NT-proBNP reference range were lower than the data came from Wester people.A suitable reference range play a important role.
In this article, a series-connected SiC MOSFETs-based medium voltage (MV) dual active bridge (DAB) converter featuring a low voltage difference among devices and high efficiency is proposed. In the developed DAB converter, the zero voltage switching-on characteristic is used to redesign the voltage balancing snubber circuits of the series-connected SiC MOSFETs. The snubber resistance is greatly reduced, whereas the snubber capacitance is increased, which realizes good voltage sharing and low switching-off loss of SiC MOSFETs. Furthermore, the operating modes and the operating characteristics of MV DAB converter with large snubber capacitors are derived in detail. Based on the above analysis, snubber capacitance and auxiliary inductance are optimized, taking into account the losses and voltage imbalance in the series-connected SiC MOSFETs. Finally, a 4 kV/1 kV experimental prototype is built and tested, and an experiment with up to 100 kW transmission power has been carried out. The results show that a maximum efficiency of 98.7% has been reached and the maximum voltage difference among SiC MOSFETs does not exceed 4%.
Rationale: Sjögren syndrome (SS) is a prevalent autoimmune disorder targeting exocrine glands, causing symptoms such as dry eyes and mouth. It often goes underdiagnosed due to its varied presentations, emphasizing the importance of early and accurate diagnosis. Patient concerns: A 22-year-old female presented with atypical symptoms of hypokalemic paralysis and severe bone pain, which are not commonly associated with SS. Diagnoses: Extensive diagnostic workup, including serological tests, ophthalmological assessments, and a lip biopsy, confirmed the diagnosis of distal renal tubular acidosis as a complication of SS. Interventions: The patient was treated with an intensive inpatient regimen designed to stabilize her potassium levels and alleviate her symptoms. Outcomes: The comprehensive therapeutic intervention was successful, with the patient’s symptoms being alleviated within 2 weeks. Lessons: This case underscores the importance of being aware of SS in younger demographics and the necessity for a prompt and multifaceted treatment approach to manage systemic effects and improve quality of life.
The Isolated Bidirectional Resonant DC-DC Converter (IBRDC) is one of the most attractive solution for Solid State Transformer (SST) applications, which can achieve soft switching to improve the efficiency of the whole system. However, the efficiency of the IBRDC largely depends on the resonant parameters. These parameters are coupled to each other and are limited by several constraints, especially the voltage regulation range, making these parameters difficult to optimize. Besides, the quantitative influence of the constraints remains to be analyzed. In this paper, a parameter optimization strategy based on the minimization of resonant current with multiple constraints is proposed, which effectively reduces the difficulty of the IBRDC parameter design and therefore has high engineering application value. Furthermore, the quantitative trend of resonant parameters and the efficiency of power devices in the IBRDC are derived, and the design boundary for the IBRDC is also illustrated.
Purpose: We aimed to establish and validate a risk assessment system that combines demographic and clinical variables to predict the 3-year risk of incident diabetes in Chinese adults. Methods: A 3-year cohort study was performed on 15,928 Chinese adults without diabetes at baseline. All participants were randomly divided into a training set (n = 7,940) and a validation set (n = 7,988). XGBoost method is an effective machine learning technique used to select the most important variables from candidate variables. And we further established a stepwise model based on the predictors chosen by the XGBoost model. The area under the receiver operating characteristic curve (AUC), decision curve and calibration analysis were used to assess discrimination, clinical use and calibration of the model, respectively. The external validation was performed on a cohort of 11,113 Japanese participants. Result: In the training and validation sets, 148 and 145 incident diabetes cases occurred. XGBoost methods selected the 10 most important variables from 15 candidate variables. Fasting plasma glucose (FPG), body mass index (BMI) and age were the top 3 important variables. And we further established a stepwise model and a prediction nomogram. The AUCs of the stepwise model were 0.933 and 0.910 in the training and validation sets, respectively. The Hosmer-Lemeshow test showed a perfect fit between the predicted diabetes risk and the observed diabetes risk (p = 0.068 for the training set, p = 0.165 for the validation set). Decision curve analysis presented the clinical use of the stepwise model and there was a wide range of alternative threshold probability spectrum. And there were almost no the interactions between these predictors (most P-values for interaction >0.05). Furthermore, the AUC for the external validation set was 0.830, and the Hosmer-Lemeshow test for the external validation set showed no statistically significant difference between the predicted diabetes risk and observed diabetes risk (P = 0.824). Conclusion: We established and validated a risk assessment system for characterizing the 3-year risk of incident diabetes.
The voltage unbalance remains the most critical challenge of series-connected devices in medium-voltage high-power applications. In this paper, a behavioral model considering IGBT structure properties is proposed to balance the voltage among the series-connected trench gate/field-stop (FS) IGBTs. The equivalent circuits are presented for the voltage fast-rising stage and current tail stage respectively. Furthermore, the assumption of carrier extraction effect is applied to evaluate the phenomenon of gate voltage drop in Miller platform considering the trench gate/field stop structure. As a result, the voltage sharing in series-connected IGBTs during turn-off transient is analyzed quantitatively. The accuracy of the model is experimentally verified under different operating conditions. More importantly, this paper presents a guidance based on the proposed model for voltage balancing, which can be directly used in the design of drive and snubber circuit for series-connected IGBTs.
Abstract Background Reliable quantification of the relationship between hypertension and diabetes risk is limited, especially among Chinese people. We aimed to investigate the association between hypertension and the risk of diabetes in a large cohort of the Chinese population. Methods This was a retrospective propensity score-matched cohort study among 211,809 Chinese adults without diabetes at baseline between 2010 and 2016. The target independent and dependent variable were hypertension at baseline and incident diabetes during follow-up respectively. The propensity score matching using a non-parsimonious multivariable logistic regression was conducted to balance the confounders between 28,711 hypertensive patients and 28,711 non-hypertensive participants. The doubly robust estimation method was used to investigate the association between hypertension and diabetes. Results In the propensity-score matching cohort, diabetes risk increased by 11.0% among hypertensive patients (HR = 1.110, 95% confidence interval (CI): 1.031–1.195, P = 0.00539). And diabetes risk dropped to 8.3% among hypertensive subjects after adjusting for the propensity score (HR = 1.083, 95%CI: 1.006–1.166, P = 0.03367). Compared to non-hypertensive participants with low propensity score, the risk of incident diabetes increased by 2.646 times among hypertensive patients with high propensity score (HR = 3.646, 95%CI: 2.635–5.045, P < 0.0001). Conclusion Hypertension was associated with an 11.0% increase in the risk of developing diabetes in Chinese adults. And the figure dropped to 8.3% after adjusting the propensity score. Additionally, compared to non-hypertensive participants with low propensity scores, the risk of incident diabetes increased by 2.646 times among hypertensive patients with high propensity scores.
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