System Identification and Control of Cavity Noise Reduction

This dissertation first presents indirect closed-loop system identification through residual whitening, then identifies the cavity noise system and applies controllers to reduce the noise. High speed air flow over the cavity produces a complex oscillatory flow-field and induces pressure oscillations within the cavity. The existence of cavities induces large pressure fluctuations which generate undesirable and loud noise. This may have an adverse effect on the objects, such as reducing the stability and performance of overall system, or damaging the sensitive instruments within the cavity. System identification is the process of building mathematical models of dynamical systems based on the available input and output data from the systems. The indirect system identification by residual whitening is used to improve the accuracy of the identification result, and the optimal properties of the Kalman filter could be enforced for a finite set of data through residual whitening. Linear Quadratic Gaussian (LQG) and deadbeat controllers are applied to obtain the desired system performance. Linear Quadratic Gaussian (LQG) control design is the technique of combining the linear quadratic regulator (LQR) and Kalman tilter together, namely, state feedback (LQR) and state estimation (Kalman filter). Deadbeat control design is to bring the output to zero, and both indirect and direct algorithms are applied. For the indirect method, one needs to calculate the finite difference model coefficient parameters first, then form the control parameters. In the recursive direct algorithms, however, one can compute the control parameters directly. When systems change with time, the system parameters become time-varying. An adaptive predictive control is needed for this situation. Since the system parameters are time-varying, the control parameters need to be updated in order to catch up with the systems\u27 changes. The classical recursive least-squares technique is used for the recursive deadbeat controller, and it could be operated for on-line application

STAT3 Cooperates With Phospholipid Scramblase 2 to Suppress Type I Interferon Response

Type I interferon (IFN-I) is a pluripotent cytokine that modulates innate and adaptive immunity. We have previously shown that STAT3 suppresses IFN-I response in a manner dependent on its N-terminal domain (NTD), but independent of its DNA-binding and transactivation ability. Using the yeast two-hybrid system, we have identified phospholipid scramblase 2 (PLSCR2) as a STAT3 NTD-binding partner and a suppressor of IFN-I response. Overexpression of PLSCR2 attenuates ISRE-driven reporter activity, which is further aggravated by co-expression of STAT3. Moreover, PLSCR2 deficiency enhances IFN-I-induced gene expression and antiviral activity without affecting the activation or nuclear translocation of STAT1 and STAT2 or the assembly of ISGF3 complex. Instead, PLSCR2 impedes promoter occupancy by ISGF3, an effect further intensified by the presence of STAT3. Moreover, palmitoylation of PLSCR2 is required for its binding to STAT3 and for this suppressive activity. In addition to STAT3, PLSCR2 also interacts with STAT2, which facilitates the suppressive effect on ISGF3-mediated transcriptional activity. Together, these results define the role of a novel STAT3–PLSCR2 axis in fine-tuning IFN-I response

Inhibition of Serine Protease Activity Protects Against High Fat Diet-Induced Inflammation and Insulin Resistance.

Recent evidence suggests that enhanced protease-mediated inflammation may promote insulin resistance and result in diabetes. This study tested the hypothesis that serine protease plays a pivotal role in type 2 diabetes, and inhibition of serine protease activity prevents hyperglycemia in diabetic animals by modulating insulin signaling pathway. We conducted a single-center, cross-sectional study with 30 healthy controls and 57 patients with type 2 diabetes to compare plasma protease activities and inflammation marker between groups. Correlations of plasma total and serine protease activities with variables were calculated. In an in-vivo study, LDLR-/- mice were divided into normal chow diet, high-fat diet (HFD), and HFD with selective serine protease inhibition groups to examine the differences of obesity, blood glucose level, insulin resistance and serine protease activity among groups. Compared with controls, diabetic patients had significantly increased plasma total protease, serine protease activities, and also elevated inflammatory cytokines. Plasma serine protease activity was positively correlated with body mass index, hemoglobin A1c, homeostasis model assessment-insulin resistance index (HOMA-IR), tumor necrosis factor-α, and negatively with adiponectin concentration. In the animal study, administration of HFD progressively increased body weight, fasting glucose level, HOMA-IR, and upregulated serine protease activity. Furthermore, in-vivo serine protease inhibition significantly suppressed systemic inflammation, reduced fasting glucose level, and improved insulin resistance, and these effects probably mediated by modulating insulin receptor and cytokine expression in visceral adipose tissue. Our findings support the serine protease may play an important role in type 2 diabetes and suggest a rationale for a therapeutic strategy targeting serine protease for clinical prevention of type 2 diabetes

A novel randomly textured phosphor structure for highly efficient white light-emitting diodes

We have successfully demonstrated the enhanced luminous flux and lumen efficiency in white light-emitting diodes by the randomly textured phosphor structure. The textured phosphor structure was fabricated by a simple imprinting technique, which does not need an expensive dry-etching machine or a complex patterned definition. The textured phosphor structure increases luminous flux by 5.4% and 2.5% at a driving current of 120 mA, compared with the flat phosphor and half-spherical lens structures, respectively. The increment was due to the scattering of textured surface and also the phosphor particles, leading to the enhancement of utilization efficiency of blue light. Furthermore, the textured phosphor structure has a larger view angle at the full width at half maximum (87°) than the reference LEDs

Risk factors and outcomes of carbapenem-nonsusceptible Escherichia coli bacteremia: A matched case–control study

BackgroundInfections due to carbapenem-resistant Enterobacteriaceae have been the emerging problem worldwide. This primary object of this study was to understand the risk factors and clinical outcomes of carbapenem-nonsusceptible Escherichia coli (CNSEc) bacteremia.MethodsWe conducted a matched case–control study in a 3,715-bed tertiary care medical center in northern Taiwan. The controls were selected among patients with carbapenem-susceptible E coli and were matched with CNSEc for bacteremia.ResultsFifty-one patients were included in this study (17 cases and 34 controls). Bivariate analysis showed that prior exposure to carbapenems (p<0.001), stay in intensive care units (p=0.016), placement of central venous catheters (p=0.001), chronic liver diseases (p<0.001), uremia with regular dialysis (p=0.004), and mechanical ventilation (p=0.004) were associated with CNSEc bacteremia. Multivariate analysis revealed that prior exposure to carbapenems [odds ratio (OR), 29.17; 95% confidence interval (CI), 1.76–484.70; p=0.019], uremia with regular dialysis (OR, 98.58; 95% CI, 4.02–999; p=0.005) and chronic liver diseases (OR, 27.86; 95% CI, 2.31–335.83; p=0.009) were independent risk factors for CNSEc bacteremia. Compared with carbapenem-susceptible E coli group, CNSEc group had a longer hospital stay (68.4 days vs. 35.8 days; p=0.04) and a higher disease severity, as indicated by a Pittsburgh bacteremia score greater than or equal to 4 (5.6% vs. 2.5%; p=0.015). Patients with CNSEc bacteremia had a higher overall in-hospital mortality rate (94.12% vs. 50.00%; p=0.002), but there was no difference in the 28-day mortality between these two groups.ConclusionsCNSEc bacteremia would lead to a poor outcome among patients with prior exposure to carbapenems, chronic liver disease, and uremia with regular dialysis

Diagnostic efficacy of the triglyceride–glucose index in the prediction of contrast-induced nephropathy following percutaneous coronary intervention

IntroductionContrast-induced nephropathy (CIN) is a common complication of percutaneous coronary intervention (PCI). Identifying patients at high CIN risk remains challenging. The triglyceride-glucose (TyG) index may help predict CIN but evidence is limited. We conducted a meta-analysis to evaluate the diagnostic value of TyG index for CIN after PCI.MethodsA systematic literature search was performed in MEDLINE, Cochrane, and EMBASE until August 2023 (PROSPERO registration: CRD42023452257). Observational studies examining TyG index for predicting CIN risk in PCI patients were included. This diagnostic meta-analysis aimed to evaluate the accuracy of the TyG index in predicting the likelihood of CIN. Secondary outcomes aimed to assess the pooled incidence of CIN and the association between an elevated TyG index and the risk of CIN.ResultsFive studies (Turkey, n=2; China, n=3) with 3518 patients (age range: 57.6 to 68.22 years) were included. The pooled incidence of CIN was 15.3% [95% confidence interval (CI) 11-20.8%]. A high TyG index associated with increased CIN risk (odds ratio: 2.25, 95% CI 1.82-2.77). Pooled sensitivity and specificity were 0.77 (95% CI 0.59-0.88) and 0.55 (95% CI 0.43-0.68) respectively. Analysis of the summary receiver operating characteristic (sROC) curve revealed an area under the curve of 0.69 (95% CI 0.65-0.73). There was a low risk of publication bias (p = 0.81).ConclusionThe TyG index displayed a noteworthy correlation with the risk of CIN subsequent to PCI. However, its overall diagnostic accuracy was found to be moderate in nature. While promising, the TyG index should not be used in isolation for CIN screening given the heterogeneity between studies. In addition, the findings cannot be considered conclusive given the scarcity of data. Further large-scale studies are warranted to validate TyG cutoffs and determine how to optimally incorporate it into current risk prediction models.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023452257, identifier CRD42023452257

Soluble Form of Receptor for Advanced Glycation End Products Is Associated with Obesity and Metabolic Syndrome in Adolescents

The aim of this cross-sectional study was to investigate the relationship between soluble form of receptor for advanced glycation end products (sRAGE), obesity, and metabolic syndrome (MetS) in adolescents. A total of 522 male and 561 female adolescents were enrolled into the final analyses. Anthropometric parameters, blood pressure, blood biochemistry, fasting insulin, and plasma sRAGE levels were measured. In males, sRAGE was significantly and inversely correlated with waist circumference (WC), body mass index (BMI), systolic blood pressure, triglyceride (TG), low density lipoprotein cholesterol (LDL-C), and homeostasis model assessment-insulin resistance (HOMA-IR). Only WC and BMI were significantly and inversely correlated with sRAGE in females. Using linear regression analysis adjusting for age and gender, significant association was found between sRAGE and WC, BMI, TG, LDL-C, and HOMA-IR in adolescents of either gender (P<0.05). This association was abolished when further adjusting BMI. In addition, sRAGE was significantly and inversely correlated with the increasing number of components of MetS in males (P for trend = 0.006) but not in females (P for trend = 0.422). In conclusion, plasma sRAGE is associated with obesity and MetS among adolescents. BMI may be the most important determinant of sRAGE levels in adolescents

Association Between Acid-Sensing Ion Channel 3 Gene Variants and Balance Impairment in People With Mild Traumatic Brain Injury

Introduction: Dizziness and balance impairment are common symptoms of mild traumatic brain injury (mTBI). Acid-sensing ion channel 3 (ASIC3) is expressed in the vestibular and proprioceptive systems and associated with balance functions. However, whether the genetic variants of ASIC3 are associated with people who suffer dizziness and balance impairment after mTBI remained unknown.Materials and methods: A total of 200 people with mTBI and 109 non-mTBI controls were recruited. Dizziness, balance functions, and the ability to perform daily activities were assessed by Dizziness Handicap Inventory (DHI), and objective balance functions were investigated by the postural stability test. Three diseases-related genetic variants of ASIC3 were determined through polymerase chain reaction and followed by restriction fragment length polymorphism. The Student's t-test and Mann-Whitney U-test were used for normal and abnormal distributed data, respectively. The regression was applied to adjust gender and age. The normality of continuous data was evaluated by Shapiro-Wilk test.Results: In the mTBI people, the rs2288645-A allele carriers exhibited a significantly worse physical domain DHI score (A-allele carriers: 11.39 ± 8.42, non-A carriers: 8.76 ± 7.87, p = 0.03). The rs4148855-GTC deletion carriers an exhibited significantly worse overall postural stability (GTC deletion carriers: 0.53 ± 0.33, non-carriers: 0.46 ± 0.20, p = 0.03). In the controls, rs2288646-A allele carriers were significant worse in the medial-to-lateral postural stability (A-allele carriers: 0.31 ± 0.17, non-A carriers: 0.21 ± 0.10, p = 0.01).Conclusion: The present study demonstrated that ASIC3 genetic variants were associated with certain aspects of balance functions and dizziness questionnaires in people of mTBI and non-mTBI. It provides a possible evidence that ASIC3 could be a new target for the management of the balancing disorders. However, further investigations are warranted to elucidate the underlying mechanisms and clinical significance