Szu-Chi Chen

Diagnosis of more gestational diabetes lead to better pregnancy outcomes: Comparing the International Association of the Diabetes and Pregnancy Study Group criteria, and the Carpenter and Coustan criteria

The International Association of the Diabetes and Pregnancy Study Group (IADPSG) criteria for gestational diabetes are associated with increased prevalence. However, it remains unknown if intervention for more women with gestational diabetes mellitus by the IADPSG criteria results in better pregnancy outcomes than adopting the Carpenter and Coustan (C&C) criteria in Asian populations.

Power system feedback stabilizer design via optimal subeigenstructure assignment

Power system stabilizer (PSS) design is addressed using an optimal reduced order model whose state variables are torque angles and speeds. System damping can be improved by using eigenvalue assignment, and the coordination of stabilizers can be achieved through eigenvector assignment by maintaining system mode shapes. The proportional-integral PSSs are derived by the optimal reduced order model. The effectiveness of the stabilizer is evaluated. By using the output feedback only, the result of eigenstructure assignment is more stable and much better than the assignment method based on the whole system model. Examples, a single-machine to infinite bus system and a multimachine system, are given to illustrate the advantages and effectiveness of the proposed approach. Results based on the whole system model are included for comparative analyses. >

Association of the variations in the HSD3β gene with primary aldosteronism.

Objective: In mice, a lack of cryptochrome results in up-regulation of aldosterone production due to high expression of the 3&bgr;-hydroxysteroid dehydrogenases (HSD3&bgr;) gene. The HSD3&bgr; pathway might play a pivotal role in aldosterone synthesis. This study aimed to determine the association of HSD3&bgr; and HSD3&bgr;2 gene variations with primary aldosteronism in a Taiwanese population. Method: In this case–control cohort, 688 consecutive ethnically matched unrelated individuals including 362 primary aldosteronism and 326 essential hypertension cases were recruited. Nineteen tag single-nucleotide polymorphisms (SNPs) across HSD3&bgr;1, HSD3&bgr;2, and CYP11&bgr;2 were genotyped. Expression of HSD3&bgr; mRNA and immunohistochemical stain of HSD3&bgr; in the specimens of aldosterone-producing adenoma (APA) was compared with that in nonfunctional incidentaloma. Results: The SNPs of rs12410453 A allele in HSD3&bgr;2 gene [odds ratio (OR) 1.92, 95% confidence interval (CI) 1.13–3.32, P = 0.018] and rs6203 C allele in the HSD3&bgr;1 gene (OR 2.21, 95% CI 1.28–3.95, P = 0.006) showed significant association with primary aldosteronism, with corresponding population attributable risk of 6.7 and 30.7%, respectively. Primary aldosteronism patients of non-CC in rs6203 and non-GA in rs12401453 had lower plasma aldosterone-to-renin ratio. A haplotype in a linkage disequilibrium block containing rs6203 associated significantly with serum potassium level (OR 1.24, 95% CI 1.02–1.24, P = 0.026). The expressions of HSD3&bgr;1 mRNA, HSD3&bgr;2 mRNA and HSD3&bgr; protein were increased in APA, as compared to incidentaloma. Conclusion: Risk-conferring genetic variations in the HSD3&bgr; gene influenced susceptibility of primary aldosteronism. Concomitant presence of rs6203 CC and rs12410453 GA genotypes synergistically increased aldosterone-to-renin ratio.

Screening gestational diabetes mellitus: The role of maternal age

Objective Using a specific cutoff of fasting plasma glucose (FPG) to screen gestational diabetes mellitus (GDM) can reduce the use of oral glucose tolerance tests (OGTT). Since the prevalence of GDM increases with age, this screening method may not be appropriate in healthcare systems where women become pregnant at older ages. Therefore, we aimed to develop a screening algorithm for GDM that takes maternal age into consideration. Methods We included 945 pregnant women without history of GDM who received 75g OGTT to diagnose GDM in 2011. Screening algorithms using FPG with or without age were developed. Another 362 pregnant women were recruited in 2013–2015 as the validation cohort. Results Using FPG criteria alone, more GDM diagnoses were missed in women ≥35 years than in women <35 years (13.2% vs. 5.8%, p <0.001). Among GDM women ≥35 years, 63.6% had FPG <92 mg/dL (5.1 mmol/L). Use of the algorithm with an “age plus FPG” cutoff could reduce the use of OGTT (OGTT%) from 77.6% to 62.9%, while maintaining good sensitivity (from 91.9% to 90.2%) and specificity (from 100% to 100%). Similar reduction in OGTT% was found in the validation cohort (from 86.4% to 76.8%). In the simulation, if the percentage of women ≥35 years were 40% or more, the screening algorithm with an “age plus FPG” cutoff could further reduce OGTT% by 11.0%-18.8%. Conclusions A screening algorithm for GDM that takes maternal age into consideration can reduce the use of OGTT when women become pregnant at older ages.

TWO-LEVEL OPTIMAL PI CONTROLLER DESIGN

ABSTRACT This paper addresses the design of two-level Power System Stabilizers using an optimal reduced order model whose state variables are torque angles and speeds. The reduced-order model retains their physical meaning and is used to design a two-level linear feedback controller that takes into account the realities and constraints of eletric power system. The two-level control strategy is used and a global control signal is generated from the output variables to minimize the effect of interactions. Effectiveness of this controller is evaluated and an example of a multimachine system, is given to illustrate the advantage of the proposed method. Reponses of the system with two-level scheme and optimal reduced order scheme are included for comparative analysis.