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The direct current (DC) microgrid is one of the key research areas for our advancement toward carbon-free energy production. In this paper, a two-step controller is designed for the DC microgrid using a combination of the deep neural network (DNN) and exponential reaching law-based global terminal sliding mode control (ERL-GTSMC). The DC microgrid under consideration involves multiple renewable sources (wind, PV) and an energy storage unit (ESU) connected to a 700 V DC bus and a 4-12 kW residential load. The proposed control method eliminates the chattering phenomenon and offers quick reaching time by utilizing the exponential reaching law (ERL). In the two-step control configuration, first, DNNs are used to find maximum power point tracking (MPPT) reference values, and then ERL-based GTSMC is utilized to track the reference values. The real dynamics of energy sources and the DC bus are mathematically modeled, which increases the system's complexity. Through the use of Lyapunov stability criteria, the stability of the control system is examined. The effectiveness of the suggested hybrid control algorithm has been examined using MATLAB simulations. The proposed framework has been compared to traditional sliding mode control and terminal sliding mode control to showcase its superiority and robustness. Experimental tests based on the hardware-in-the-loop (HIL) setup are then conducted using 32-bit TMS320F28379D microcontrollers. Both MATLAB and HIL results show strong performance under a range of environmental circumstances and system uncertainties.
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INTRODUCTION AND OBJECTIVES: The management of bilateral ureteropelvic junction obstruction (UPJO) is greatly debated. We aim to identify the risk of early postoperative acute kidney injury (AKI) in relation to the sequence of intervention in children with bilateral UPJO managed in a sequential manner. METHODS: A single center database was retrospectively reviewed for children ≤2 years who underwent bilateral pyeloplasty. According to the differential renal function on the preoperative renograms, patients were categorized into group A: pyeloplasty on the poorer functioning kidney first and group B: pyeloplasty on the better functioning side first. Serum creatinine and eGFR, using the modified Schwartz formula, were evaluated at four time points (I): before the first intervention (II): within 48 h of the first intervention (III): before the second intervention and (IV): within 48 h of the second intervention. Preoperative and postoperative values were compared. The incidence of early postoperative AKI in both groups was defined according to the Acute Kidney Injury Network (AKIN) criteria. RESULTS: The study comprised 46 children treated by staged pyeloplasty, 28 of them underwent pyeloplasty on the poorer functioning side first. Baseline serum creatinine and eGFR were not significantly different between both groups. Patients who underwent pyeloplasty on the poorer functioning side first, had a significant decline of eGFR after the first intervention (p = 0.006). Conversely, no significant eGFR changes were observed after the first or second interventions in the other group (figure). Overall, 64.3% and 33.3% of patients developed some degrees of AKI when intervention was started on the poorer and better functioning renal units, respectively (p = 0.04). DISCUSSION: Bilaterality is seen in approximately » of patients with UPJO. Oftentimes, both renal units are asymmetrically affected with little data to guide surgeons on the optimal sequence of intervention. Following pyeloplasty, 52.2% of the evaluated children with bilateral UPJO had early postoperative AKI, mostly of low stage. Our data suggest that intervening first on the better functioning side allows for better recovery of the renal functional reserve and lowers the risk of postoperative AKI. CONCLUSION: In children with bilateral UPJO, starting intervention on the poorer functioning kidney is associated with increased risk of postoperative AKI. Long-term prospective studies are needed to confirm our findings.
Subject(s)
Acute Kidney Injury , Ureteral Obstruction , Child , Humans , Infant , Kidney Pelvis/surgery , Retrospective Studies , Creatinine , Ureteral Obstruction/complications , Acute Kidney Injury/etiology , Urologic Surgical Procedures , Treatment OutcomeABSTRACT
Objective: To assess the long-term outcomes after pyeloplasty for pelvi-ureteric junction obstruction (PUJO) associated with renal anomalies. Patients and methods: Data were collected for patients after pyeloplasty for PUJO associated with renal anomalies and analysed retrospectively. Long-term functional success was evaluated by comparing the renographic split renal function (SRF) and glomerular filtration rate (GFR) at last follow-up with baseline values. A change of 5% in SRF was considered significant. Factors affecting functional outcome were assessed. The outcomes were compared to an age, sex and renal function matched group with PUJO in otherwise normal kidneys (Group 2) to evaluate the pattern of difference in functional recoverability in both groups. This was assessed using repeated-measures analysis of variance. Results: The study initially included 70 adult patients, with a mean age of 31.8 years. At a median of 44 months, 55 patients completed follow-up (Group 1) and no statistically significant changes in GFR (P = 0.7) and SRF (P = 0.06) were found. In all, 17, four and 34 patients showed a decrease, increase and static SRF (functional success rate was 69%). Higher preoperative SRF (P = 0.02) and Anderson-Hynes (A-H) pyeloplasty (P = 0.003) were associated with functional preservation. In the comparison with the other matched group (Group 2), the patients in Group 2 had better functional recoverability after pyeloplasty than patients with associated anomalies [GFR (P = 0.001), SRF (P = 0.002) and functional success (P = 0.001)]. Conclusion: Functional preservation after pyeloplasty in associated renal anomalies could be achieved in 69% of patients, which was significantly lower than those with otherwise normal kidneys. A-H pyeloplasty and higher preoperative SRF were associated with better functional outcomes. Abbreviations: A-H: Anderson-Hynes; HSK: horseshoe kidneys; OR: odds ratio; PUJO: PUJ obstruction; SRF: split renal function; T1/2, half-time.
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OBJECTIVE: To assess the bioavailability of norfloxacin from urinary excretion relative to plasma concentration. MATERIALS AND METHODS: Twelve healthy volunteers (22-33 years) participated in the study. Each received a previously developed (M), a local (L) and a multinational (Noroxin) tablet (Ref), 400 mg each, according to a random balanced three-way crossover design on 3 different days. Blood samples were collected over a 12-hour period and urine over a 24-hour period. Norfloxacin concentrations were analyzed by a validated HPLC method. RESULTS: An initial estimate of bioequivalence of the three products was obtained using analysis of variance on transformed data and based on confidence interval calculation. Elimination pharmacokinetic parameters (half-life and renal clearance) calculated from plasma concentration and urinary excretion data (mean values, n = 36) were comparable to reported values for norfloxacin. Interproduct differences in elimination parameters (mean values, n = 12) were statistically insignificant (F values, ANOVA). Strong association was found between the mean of plasma concentration and urinary excretion rates for many volunteers (F values, regression analysis). Relative bioavailability values calculated for the local and previously developed products relative to Noroxin were higher than 85% based on area under the curve and urinary excretion. Bioequivalence could not be established among the three tested products based on calculated 90% confidence intervals. CONCLUSION: Urinary excretion of norfloxacin may be a useful noninvasive tool for bioavailability assessment of norfloxacin oral formulations.
