Challenges of Junction Temperature Sensing in SiC Power MOSFETs

J. Ortiz Gonzalez,O. Alatise 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Junction temperature sensing is an integral part of both on-line and off-line condition monitoring where direct access the bare die surface is not available. Given a defined power input, the junction temperature enables the estimation of the junction-to-case thermal resistance, which is a key indicator of packaging failure mechanisms like solder voiding and cracks. The use of temperature sensitive electrical parameters (TSEPs) has widely been proposed as a means of junction temperature sensing however, in SiC power devices there are certain challenges regarding the use of TSEPs. Bias Temperature Instability (BTI) from charge trapping in the gate dielectric causes threshold voltage drift, which in SiC affects some of the key TSEPs including ON-state resistance, body diode forward voltage as well as the turn-ON current commutation rate. This paper reviews the challenges of junction temperature sensing in SiC power devices, the impact of BTI on TSEPs and how different researchers have approached the issue of power cycling SiC power devices and modules.

Effect of Artemisia dracunculus Administration on Glycemic Control, Insulin Sensitivity, and Insulin Secretion in Patients with Impaired Glucose Tolerance

Miriam Mendez-del Villar,Ana M. Puebla-Perez,Maria J. Sanchez-Pena,Luis J. Gonzalez-Ortiz,Esperanza Martinez-Abundis,Manuel Gonzalez-Ortiz 한국식품영양과학회 2016 Journal of medicinal food Vol.19 No.5

To evaluate the effect of Artemisia dracunculus on glycemic control, insulin sensitivity, and insulin secretion in patients with impaired glucose tolerance (IGT). A randomized, double blind, placebo-controlled clinical trial was performed in 24 patients with diagnosis of IGT. Before and after the intervention, glucose and insulin levels were measured every 30 min for 2 h after a 75-g dextrose load, along with glycated hemoglobin A1c (A1C) and lipid profile. Twelve patients received A. dracunculus (1000 mg) before breakfast and dinner for 90 days; the remaining 12 patients received placebo. Area under the curve (AUC) of glucose and insulin, total insulin secretion, first phase of insulin secretion, and insulin sensitivity were calculated. Wilcoxon signed-rank, Mann–Whitney U, and chi-square tests were used for statistical analyses. The institutional ethics committee approved the protocol. After A. dracunculus administration, there were significant decreases in systolic blood pressure (SBP; 120.0 ± 11.3 vs. 113.0 ± 11.2 mmHg, P < .05), A1C (5.8 ± 0.3 vs. 5.6% ± 0.4%, P < .05), AUC of insulin (56,136.0 ± 27,426.0 vs. 44,472.0 ± 23,370.0 pmol/L, P < .05), and total insulin secretion (0.45 ± 0.23 vs. 0.35 ± 0.18, P < .05), with a significant increase in high-density lipoprotein cholesterol (HDL-C) (1.3 ± 0.3 vs. 1.4 ± 0.3 mmol/L, P < .05). There were no significant differences after placebo administration. A. dracunculus administration for 90 days in patients with IGT significantly decreased SBP, A1C, AUC of insulin, and total insulin secretion with a significant increase in HDL-C levels.

Decreased Esophageal Sensitivity to Acid in Morbidly Obese Patients: A Cause for Concern?

( Vicente Ortiz ),( Diego Alvarez-sotomayor ),( Esteban Saez-gonzalez ),( Francia Carolina Diaz-jaime ),( Marisa Iborra ),( Julio Ponce ),( Vicente Garrigues ) 대한간학회 2017 Gut and Liver Vol.11 No.3

Background/Aims: To evaluate esophageal sensitivity to acid between morbidly obese (MO) patients and non-MO controls with abnormal esophageal acid exposure. Methods: We conducted a cross-sectional study of 58 patients: 30 MO (cases) and 28 non-MO (controls). Esophageal symptoms and esophageal sensitivity to 0.1 M hydrochloric acid solution (Bernstein test) were compared between MO and non- MO patients with a prior diagnosis of abnormal esophageal acid exposure. Results: MO patients were less symptomatic than non-MO controls (14% vs 96%; odds ratio [OR], 0.006; 95% confidence interval [CI], 0.001 to 0.075; p=0.000). MO patients were more likely to present with decreased esophageal sensitivity to the instillation of acid than non-MO controls (57% vs 14%; OR, 8; 95% CI, 1.79 to 35.74; p=0.009). Subgroup analysis revealed no differences in esophageal sensitivity in MO patients with and without abnormal esophageal acid exposure (43% vs 31%; p=0.707). Conclusions: Silent gastroesophageal reflux disease (GERD) is common among MO individuals, likely due to decreased esophageal sensitivity to acid. The absence of typical GERD symptoms in these patients may delay discovery of precancerous conditions, such as Barrett`s esophagus. We believe that these patients may require a more aggressive diagnostic work-up to rule out the presence of silent GERD. (Gut Liver 2017;11:358-362)

Image and Learning : Opioid-induced Lower Esophageal Sphincter Dysfunction

( Esteban Saez Gonzalez ),( Vicente Ortiz Bellver ),( Francia Carolina Diaz Jaime ),( Juan Antonio Ortuno Cortes ),( Vicente Garrigues Gil ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2015 Journal of Neurogastroenterology and Motility (JNM Vol.21 No.4

Effect of Gymnema sylvestre Administration on Metabolic Syndrome, Insulin Sensitivity, and Insulin Secretion

Laura Y. Zuniga,Manuel Gonzalez-Ortiz,Esperanza Martınez-Abundis 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.8

Gymnema sylvestre is a medicinal plant whose consumption has demonstrated benefits on lipid and glucose levels, blood pressure, and body weight (BWt). The aim of this study was to evaluate the effect of G. sylvestre administration on metabolic syndrome (MetS), insulin secretion, and insulin sensitivity. A randomized, double-blind, placebo-controlled clinical trial was carried out in 24 patients (without pharmacological treatment), 30–60 years old, with diagnosis of MetS in accordance with the modified International Diabetes Federation criteria. Patients were randomly assigned to receive G. sylvestre or placebo twice daily before breakfast and dinner in 300 mg capsules for a total of 600 mg per day for 12 weeks. Before and after the intervention, the components of MetS were evaluated as well as BWt, body mass index (BMI), total cholesterol, low-density lipoprotein cholesterol, and very low-density lipoprotein (VLDL). Area under the curve of glucose and insulin, phases of insulin secretion, and insulin sensitivity were calculated. Statistical analysis was performed using Wilcoxon signed-rank, Mann–Whitney U, and chi-square tests; P ≤ .05 was considered statistically significant. After G. sylvestre administration, significant decreases in BWt (81.3 ± 10.6 kg vs. 77.9 ± 8.4 kg, P = .02), BMI (31.2 ± 2.5 kg/m2 vs. 30.4 ± 2.2 kg/m2, P = .02), and VLDL levels (0.45 ± 0.15 mmol/dL vs. 0.35 ± 0.15 mmol/dL, P = .05) were observed, without modifying the components of MetS, insulin secretion, and insulin sensitivity. In conclusion, G. sylvestre administration decreased BWt, BMI, and VLDL levels in subjects with MetS, without changes in insulin secretion and insulin sensitivity.

PROBIOTIC BACTERIA FROM PUSTULOSE ARK (Anadara tuberculosa) ENHANCE IMMUNE AND ANTIOXIDANT RESPONSE IN SHRIMP FARMING

Ana Claudia Sanchez-Ortiz,Antonio Luna-Gonzalez,Jose M. Mazon-Suastegui,Angel I. Campa-Cordova 한국수산과학회 양식분과 2015 한국수산과학회 양식분과 학술대회 Vol.2015 No.5

Effect of Irvingia gabonensis on Metabolic Syndrome, Insulin Sensitivity, and Insulin Secretion

Miriam Mendez-del Villar,Manuel Gonzalez-Ortiz,Esperanza Martınez-Abundis,Karina G. Perez-Rubio,Marisol Cortez-Navarrete 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.6

The aim of this study was to evaluate the effect of Irvingia gabonensis on metabolic syndrome (MetS), insulin sensitivity, and insulin secretion. A randomized, double-blind, placebo-controlled clinical trial was performed in 24 patients with MetS in accordance with the International Diabetes Federation criteria. Twelve patients received I. gabonensis (150 mg) twice a day during 90 days, and 12 patients received placebo. Glucose and insulin concentrations were measured during a 2-h oral glucose tolerance test. Also, lipid profile, creatinine, uric acid, and hepatic enzymes were determined. The area under the curve (AUC) of glucose and insulin, total insulin secretion, first phase of insulin secretion, and insulin sensitivity were calculated. Data were tested using non-parametric tests. The Ethics Committee approved the protocol. After I. gabonensis administration, significant decreases in waist circumference (WC) (94.0 ± 8.0 vs. 91.0 ± 8.2 cm, P < .01), glucose 90' (10.0 ± 2.5 vs. 8.6 ± 2.7 mmol/L, P < .05), glucose 120' (8.8 ± 2.4 vs. 7.6 ± 2.7 mmol/L, P < .05), triglycerides (2.5 ± 1.2 vs. 2.0 ± 1.1 mmol/L, P < .05), very low-density lipoproteins (VLDL) (0.5 ± 0.2 vs. 0.4 ± 0.2 mmol/L, P < .05), and AUC of glucose (694 ± 142 vs. 629 ± 172 mmol/L/min, P < .05) were found. Seven patients (58.3%) of the I. gabonensis group showed remission of MetS and two patients (16.7%) of the placebo group (P = .045). I. gabonensis lead to remission of MetS in 58.3% of the patients and significantly decreased WC, glucose 90', glucose 120', triglycerides, VLDL, and AUC of glucose.

Effect of Ursolic Acid on Metabolic Syndrome, Insulin Sensitivity, and Inflammation

Alejandra M. Ramırez-Rodrıguez,Manuel Gonzalez-Ortiz,Esperanza Martınez-Abundis,Natalhie Acuna Ortega 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.9

To evaluate the effect of ursolic acid on metabolic syndrome, insulin sensitivity, and inflammation, a randomized, double-blind, placebo-controlled clinical trial was carried out in 24 patients (30–60 years) with a diagnosis of metabolic syndrome without treatment. They were randomly assigned to two groups of 12 patients, each to receive orally 150 mg of ursolic acid or homologated placebo once a day for 12 weeks. Before and after the intervention, the components of metabolic syndrome, insulin sensitivity (Matsuda index), and inflammation profile (interleukin-6 and C-reactive protein) were evaluated. After ursolic acid administration, the remission of metabolic syndrome occurred in 50% of patients (P = .005) with significant differences in body weight (75.7 ± 11.5 vs. 71 ± 11 kg, P = .002), body mass index (BMI) (29.9 + 3.6 vs. 24.9 ± 1.2 kg/m2, P = .049), waist circumference (93 ± 8.9 vs. 83 + 8.6 cm, P = .008), fasting glucose (6.0 ± 0.5 vs. 4.7 ± 0.4 mmol/L, P = .002), and insulin sensitivity (3.1 ± 1.1 vs. 4.2 ± 1.2, P = .003). Ursolic acid administration leads to transient remission of metabolic syndrome, reducing body weight, BMI, waist circumference and fasting glucose, as well as increasing insulin sensitivity.

Modeling of Temperature Dependent Parasitic Gate Turn-On in Silicon IGBTs

R. Bonyadi,O. Alatise,S. Jahdi,J. Ortiz Gonzalez,L. Ran,P. A. Mawby 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Parasitic turn-on can cause unintentional triggering of the IGBTs since the discharge current of the Miller capacitance coupled with high dV/dt can activate a device that should be off. The short circuit current resulting from parasitic turn-on coupled with the high voltage causes significant power dissipation which can be a reliability issue. This issue is exacerbated by higher ambient temperatures since the negative temperature coefficient of the IGBT’s threshold voltage as well as the positive temperature coefficient of the minority carrier lifetime will increase the peak and duration of the short circuit current. Accurate modeling of the shoot-through power and its temperature dependency is important for circuit designers when designing mitigation techniques like multiple resistive paths and bipolar gate drivers. The physics-based model proposed in this paper can produce accurate results with good matching over temperature. The model improves on compact circuit models based on lumped parameters.

Effect of Chlorogenic Acid Administration on Glycemic Control, Insulin Secretion, and Insulin Sensitivity in Patients with Impaired Glucose Tolerance

Laura Y. Zuniga,Martha C. Aceves-de la Mora,Manuel Gonzalez-Ortiz,Julia L. Ramos-Nunez,Esperanza Martınez-Abundis 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.5

Chlorogenic acid has been described as a novel polyphenol with metabolic effects on glucose homeostasis. The aim of this study was to evaluate the effect of chlorogenic acid administration on glycemic control, insulin secretion, and insulin sensitivity in patients with impaired glucose tolerance (IGT). A randomized, double-blind, placebo-controlled clinical trial was performed in 30 patients with IGT; 15 patients randomly assigned to oral chlorogenic acid received 400 mg three times per day for 12 weeks, and the other 15 patients received placebo in the same way. Before and after the intervention, anthropometric and metabolic measurements, including fasting plasma glucose (FPG), glycated hemoglobin A1c, and a lipid profile, were performed. Area under the curve of glucose and insulin as well as the insulinogenic, Stumvoll, and Matsuda indices were calculated. Wilcoxon, Mann–Whitney U, and chi-square tests were performed, and P £ .05 was considered statistically significant. There were significant decreases in FPG (5.7 – 0.4 vs. 5.5 – 0.4 mmol/L, P = .002), insulinogenic index (0.71 – 0.25 vs. 0.63 – 0.25, P = .028), body weight, body mass index, waist circumference, triglycerides, total cholesterol, low-density lipoprotein cholesterol, and very low-density lipoprotein levels in the chlorogenic acid group, with an increment in the Matsuda index (1.98 – 0.88 vs. 2.30 – 1.23, P = .002). There were no significant differences in the placebo group. In conclusion, chlorogenic acid administration in patients with IGT decreased FPG and insulin secretion, while increasing insulin sensitivity and improving both anthropometric evaluations and the lipid profile.